diff --git a/vendor/go.etcd.io/bbolt/.gitignore b/vendor/go.etcd.io/bbolt/.gitignore
new file mode 100644
index 0000000..ed4d259
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/.gitignore
@@ -0,0 +1,12 @@
+*.prof
+*.test
+*.swp
+/bin/
+cover.out
+cover-*.out
+/.idea
+*.iml
+/bbolt
+/cmd/bbolt/bbolt
+.DS_Store
+
diff --git a/vendor/go.etcd.io/bbolt/.go-version b/vendor/go.etcd.io/bbolt/.go-version
new file mode 100644
index 0000000..7bdcec5
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/.go-version
@@ -0,0 +1 @@
+1.23.12
diff --git a/vendor/go.etcd.io/bbolt/LICENSE b/vendor/go.etcd.io/bbolt/LICENSE
new file mode 100644
index 0000000..004e77f
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Ben Johnson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/go.etcd.io/bbolt/Makefile b/vendor/go.etcd.io/bbolt/Makefile
new file mode 100644
index 0000000..f5a6703
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/Makefile
@@ -0,0 +1,108 @@
+BRANCH=`git rev-parse --abbrev-ref HEAD`
+COMMIT=`git rev-parse --short HEAD`
+GOLDFLAGS="-X main.branch $(BRANCH) -X main.commit $(COMMIT)"
+GOFILES = $(shell find . -name \*.go)
+
+TESTFLAGS_RACE=-race=false
+ifdef ENABLE_RACE
+	TESTFLAGS_RACE=-race=true
+endif
+
+TESTFLAGS_CPU=
+ifdef CPU
+	TESTFLAGS_CPU=-cpu=$(CPU)
+endif
+TESTFLAGS = $(TESTFLAGS_RACE) $(TESTFLAGS_CPU) $(EXTRA_TESTFLAGS)
+
+TESTFLAGS_TIMEOUT=30m
+ifdef TIMEOUT
+	TESTFLAGS_TIMEOUT=$(TIMEOUT)
+endif
+
+TESTFLAGS_ENABLE_STRICT_MODE=false
+ifdef ENABLE_STRICT_MODE
+	TESTFLAGS_ENABLE_STRICT_MODE=$(ENABLE_STRICT_MODE)
+endif
+
+.EXPORT_ALL_VARIABLES:
+TEST_ENABLE_STRICT_MODE=${TESTFLAGS_ENABLE_STRICT_MODE}
+
+.PHONY: fmt
+fmt:
+	@echo "Verifying gofmt, failures can be fixed with ./scripts/fix.sh"
+	@!(gofmt -l -s -d ${GOFILES} | grep '[a-z]')
+
+	@echo "Verifying goimports, failures can be fixed with ./scripts/fix.sh"
+	@!(go run golang.org/x/tools/cmd/goimports@latest -l -d ${GOFILES} | grep '[a-z]')
+
+.PHONY: lint
+lint:
+	golangci-lint run ./...
+
+.PHONY: test
+test:
+	@echo "hashmap freelist test"
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=hashmap go test -v ${TESTFLAGS} -timeout ${TESTFLAGS_TIMEOUT}
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=hashmap go test -v ${TESTFLAGS} ./internal/...
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=hashmap go test -v ${TESTFLAGS} ./cmd/bbolt
+
+	@echo "array freelist test"
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=array go test -v ${TESTFLAGS} -timeout ${TESTFLAGS_TIMEOUT}
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=array go test -v ${TESTFLAGS} ./internal/...
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=array go test -v ${TESTFLAGS} ./cmd/bbolt
+
+.PHONY: coverage
+coverage:
+	@echo "hashmap freelist test"
+	TEST_FREELIST_TYPE=hashmap go test -v -timeout ${TESTFLAGS_TIMEOUT} \
+		-coverprofile cover-freelist-hashmap.out -covermode atomic
+
+	@echo "array freelist test"
+	TEST_FREELIST_TYPE=array go test -v -timeout ${TESTFLAGS_TIMEOUT} \
+		-coverprofile cover-freelist-array.out -covermode atomic
+
+BOLT_CMD=bbolt
+
+build:
+	go build -o bin/${BOLT_CMD} ./cmd/${BOLT_CMD}
+
+.PHONY: clean
+clean: # Clean binaries
+	rm -f ./bin/${BOLT_CMD}
+
+.PHONY: gofail-enable
+gofail-enable: install-gofail
+	gofail enable .
+
+.PHONY: gofail-disable
+gofail-disable: install-gofail
+	gofail disable .
+
+.PHONY: install-gofail
+install-gofail:
+	go install go.etcd.io/gofail
+
+.PHONY: test-failpoint
+test-failpoint:
+	@echo "[failpoint] hashmap freelist test"
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=hashmap go test -v ${TESTFLAGS} -timeout 30m ./tests/failpoint
+
+	@echo "[failpoint] array freelist test"
+	BBOLT_VERIFY=all TEST_FREELIST_TYPE=array go test -v ${TESTFLAGS} -timeout 30m ./tests/failpoint
+
+.PHONY: test-robustness # Running robustness tests requires root permission for now
+# TODO: Remove sudo once we fully migrate to the prow infrastructure
+test-robustness: gofail-enable build
+	sudo env PATH=$$PATH go test -v ${TESTFLAGS} ./tests/dmflakey -test.root
+	sudo env PATH=$(PWD)/bin:$$PATH go test -v ${TESTFLAGS} ${ROBUSTNESS_TESTFLAGS} ./tests/robustness -test.root
+
+.PHONY: test-benchmark-compare
+# Runs benchmark tests on the current git ref and the given REF, and compares
+# the two.
+test-benchmark-compare: install-benchstat
+	@git fetch
+	./scripts/compare_benchmarks.sh $(REF)
+
+.PHONY: install-benchstat
+install-benchstat:
+	go install golang.org/x/perf/cmd/benchstat@latest
diff --git a/vendor/go.etcd.io/bbolt/OWNERS b/vendor/go.etcd.io/bbolt/OWNERS
new file mode 100644
index 0000000..91f168a
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/OWNERS
@@ -0,0 +1,10 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+approvers:
+  - ahrtr           # Benjamin Wang <benjamin.ahrtr@gmail.com> <benjamin.wang@broadcom.com>
+  - serathius       # Marek Siarkowicz <siarkowicz@google.com> <marek.siarkowicz@gmail.com>
+  - ptabor          # Piotr Tabor <piotr.tabor@gmail.com>
+  - spzala          # Sahdev Zala <spzala@us.ibm.com>
+reviewers:
+  - fuweid          # Wei Fu <fuweid89@gmail.com>
+  - tjungblu        # Thomas Jungblut <tjungblu@redhat.com>
diff --git a/vendor/go.etcd.io/bbolt/README.md b/vendor/go.etcd.io/bbolt/README.md
new file mode 100644
index 0000000..f365e51
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/README.md
@@ -0,0 +1,1032 @@
+bbolt
+=====
+
+[![Go Report Card](https://goreportcard.com/badge/go.etcd.io/bbolt?style=flat-square)](https://goreportcard.com/report/go.etcd.io/bbolt)
+[![Go Reference](https://pkg.go.dev/badge/go.etcd.io/bbolt.svg)](https://pkg.go.dev/go.etcd.io/bbolt)
+[![Releases](https://img.shields.io/github/release/etcd-io/bbolt/all.svg?style=flat-square)](https://github.com/etcd-io/bbolt/releases)
+[![LICENSE](https://img.shields.io/github/license/etcd-io/bbolt.svg?style=flat-square)](https://github.com/etcd-io/bbolt/blob/master/LICENSE)
+
+bbolt is a fork of [Ben Johnson's][gh_ben] [Bolt][bolt] key/value
+store. The purpose of this fork is to provide the Go community with an active
+maintenance and development target for Bolt; the goal is improved reliability
+and stability. bbolt includes bug fixes, performance enhancements, and features
+not found in Bolt while preserving backwards compatibility with the Bolt API.
+
+Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas]
+[LMDB project][lmdb]. The goal of the project is to provide a simple,
+fast, and reliable database for projects that don't require a full database
+server such as Postgres or MySQL.
+
+Since Bolt is meant to be used as such a low-level piece of functionality,
+simplicity is key. The API will be small and only focus on getting values
+and setting values. That's it.
+
+[gh_ben]: https://github.com/benbjohnson
+[bolt]: https://github.com/boltdb/bolt
+[hyc_symas]: https://twitter.com/hyc_symas
+[lmdb]: https://www.symas.com/symas-embedded-database-lmdb
+
+## Project Status
+
+Bolt is stable, the API is fixed, and the file format is fixed. Full unit
+test coverage and randomized black box testing are used to ensure database
+consistency and thread safety. Bolt is currently used in high-load production
+environments serving databases as large as 1TB. Many companies such as
+Shopify and Heroku use Bolt-backed services every day.
+
+## Project versioning
+
+bbolt uses [semantic versioning](http://semver.org).
+API should not change between patch and minor releases.
+New minor versions may add additional features to the API.
+
+## Table of Contents
+
+  - [Getting Started](#getting-started)
+    - [Installing](#installing)
+    - [Opening a database](#opening-a-database)
+    - [Transactions](#transactions)
+      - [Read-write transactions](#read-write-transactions)
+      - [Read-only transactions](#read-only-transactions)
+      - [Batch read-write transactions](#batch-read-write-transactions)
+      - [Managing transactions manually](#managing-transactions-manually)
+    - [Using buckets](#using-buckets)
+    - [Using key/value pairs](#using-keyvalue-pairs)
+    - [Autoincrementing integer for the bucket](#autoincrementing-integer-for-the-bucket)
+    - [Iterating over keys](#iterating-over-keys)
+      - [Prefix scans](#prefix-scans)
+      - [Range scans](#range-scans)
+      - [ForEach()](#foreach)
+    - [Nested buckets](#nested-buckets)
+    - [Database backups](#database-backups)
+    - [Statistics](#statistics)
+    - [Read-Only Mode](#read-only-mode)
+    - [Mobile Use (iOS/Android)](#mobile-use-iosandroid)
+  - [Resources](#resources)
+  - [Comparison with other databases](#comparison-with-other-databases)
+    - [Postgres, MySQL, & other relational databases](#postgres-mysql--other-relational-databases)
+    - [LevelDB, RocksDB](#leveldb-rocksdb)
+    - [LMDB](#lmdb)
+  - [Caveats & Limitations](#caveats--limitations)
+  - [Reading the Source](#reading-the-source)
+  - [Known Issues](#known-issues)
+  - [Other Projects Using Bolt](#other-projects-using-bolt)
+
+## Getting Started
+
+### Installing
+
+To start using `bbolt`, install Go and run `go get`:
+```sh
+$ go get go.etcd.io/bbolt@latest
+```
+
+This will retrieve the library and update your `go.mod` and `go.sum` files.
+
+To run the command line utility, execute:
+```sh
+$ go run go.etcd.io/bbolt/cmd/bbolt@latest
+```
+
+Run `go install` to install the `bbolt` command line utility into
+your `$GOBIN` path, which defaults to `$GOPATH/bin` or `$HOME/go/bin` if the
+`GOPATH` environment variable is not set.
+```sh
+$ go install go.etcd.io/bbolt/cmd/bbolt@latest
+```
+
+### Importing bbolt
+
+To use bbolt as an embedded key-value store, import as:
+
+```go
+import bolt "go.etcd.io/bbolt"
+
+db, err := bolt.Open(path, 0600, nil)
+if err != nil {
+  return err
+}
+defer db.Close()
+```
+
+
+### Opening a database
+
+The top-level object in Bolt is a `DB`. It is represented as a single file on
+your disk and represents a consistent snapshot of your data.
+
+To open your database, simply use the `bolt.Open()` function:
+
+```go
+package main
+
+import (
+	"log"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+func main() {
+	// Open the my.db data file in your current directory.
+	// It will be created if it doesn't exist.
+	db, err := bolt.Open("my.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	...
+}
+```
+
+Please note that Bolt obtains a file lock on the data file so multiple processes
+cannot open the same database at the same time. Opening an already open Bolt
+database will cause it to hang until the other process closes it. To prevent
+an indefinite wait you can pass a timeout option to the `Open()` function:
+
+```go
+db, err := bolt.Open("my.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
+```
+
+
+### Transactions
+
+Bolt allows only one read-write transaction at a time but allows as many
+read-only transactions as you want at a time. Each transaction has a consistent
+view of the data as it existed when the transaction started.
+
+Individual transactions and all objects created from them (e.g. buckets, keys)
+are not thread safe. To work with data in multiple goroutines you must start
+a transaction for each one or use locking to ensure only one goroutine accesses
+a transaction at a time. Creating transaction from the `DB` is thread safe.
+
+Transactions should not depend on one another and generally shouldn't be opened
+simultaneously in the same goroutine. This can cause a deadlock as the read-write
+transaction needs to periodically re-map the data file but it cannot do so while
+any read-only transaction is open. Even a nested read-only transaction can cause
+a deadlock, as the child transaction can block the parent transaction from releasing
+its resources.
+
+#### Read-write transactions
+
+To start a read-write transaction, you can use the `DB.Update()` function:
+
+```go
+err := db.Update(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Inside the closure, you have a consistent view of the database. You commit the
+transaction by returning `nil` at the end. You can also rollback the transaction
+at any point by returning an error. All database operations are allowed inside
+a read-write transaction.
+
+Always check the return error as it will report any disk failures that can cause
+your transaction to not complete. If you return an error within your closure
+it will be passed through.
+
+
+#### Read-only transactions
+
+To start a read-only transaction, you can use the `DB.View()` function:
+
+```go
+err := db.View(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+You also get a consistent view of the database within this closure, however,
+no mutating operations are allowed within a read-only transaction. You can only
+retrieve buckets, retrieve values, and copy the database within a read-only
+transaction.
+
+
+#### Batch read-write transactions
+
+Each `DB.Update()` waits for disk to commit the writes. This overhead
+can be minimized by combining multiple updates with the `DB.Batch()`
+function:
+
+```go
+err := db.Batch(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Concurrent Batch calls are opportunistically combined into larger
+transactions. Batch is only useful when there are multiple goroutines
+calling it.
+
+The trade-off is that `Batch` can call the given
+function multiple times, if parts of the transaction fail. The
+function must be idempotent and side effects must take effect only
+after a successful return from `DB.Batch()`.
+
+For example: don't display messages from inside the function, instead
+set variables in the enclosing scope:
+
+```go
+var id uint64
+err := db.Batch(func(tx *bolt.Tx) error {
+	// Find last key in bucket, decode as bigendian uint64, increment
+	// by one, encode back to []byte, and add new key.
+	...
+	id = newValue
+	return nil
+})
+if err != nil {
+	return ...
+}
+fmt.Println("Allocated ID %d", id)
+```
+
+
+#### Managing transactions manually
+
+The `DB.View()` and `DB.Update()` functions are wrappers around the `DB.Begin()`
+function. These helper functions will start the transaction, execute a function,
+and then safely close your transaction if an error is returned. This is the
+recommended way to use Bolt transactions.
+
+However, sometimes you may want to manually start and end your transactions.
+You can use the `DB.Begin()` function directly but **please** be sure to close
+the transaction.
+
+```go
+// Start a writable transaction.
+tx, err := db.Begin(true)
+if err != nil {
+    return err
+}
+defer tx.Rollback()
+
+// Use the transaction...
+_, err := tx.CreateBucket([]byte("MyBucket"))
+if err != nil {
+    return err
+}
+
+// Commit the transaction and check for error.
+if err := tx.Commit(); err != nil {
+    return err
+}
+```
+
+The first argument to `DB.Begin()` is a boolean stating if the transaction
+should be writable.
+
+
+### Using buckets
+
+Buckets are collections of key/value pairs within the database. All keys in a
+bucket must be unique. You can create a bucket using the `Tx.CreateBucket()`
+function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b, err := tx.CreateBucket([]byte("MyBucket"))
+	if err != nil {
+		return fmt.Errorf("create bucket: %s", err)
+	}
+	return nil
+})
+```
+
+You can retrieve an existing bucket using the `Tx.Bucket()` function:
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	if b == nil {
+		return errors.New("bucket does not exist")
+	}
+	return nil
+})
+```
+
+You can also create a bucket only if it doesn't exist by using the
+`Tx.CreateBucketIfNotExists()` function. It's a common pattern to call this
+function for all your top-level buckets after you open your database so you can
+guarantee that they exist for future transactions.
+
+To delete a bucket, simply call the `Tx.DeleteBucket()` function.
+
+You can also iterate over all existing top-level buckets with `Tx.ForEach()`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	tx.ForEach(func(name []byte, b *bolt.Bucket) error {
+		fmt.Println(string(name))
+		return nil
+	})
+	return nil
+})
+```
+
+### Using key/value pairs
+
+To save a key/value pair to a bucket, use the `Bucket.Put()` function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	err := b.Put([]byte("answer"), []byte("42"))
+	return err
+})
+```
+
+This will set the value of the `"answer"` key to `"42"` in the `MyBucket`
+bucket. To retrieve this value, we can use the `Bucket.Get()` function:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	v := b.Get([]byte("answer"))
+	fmt.Printf("The answer is: %s\n", v)
+	return nil
+})
+```
+
+The `Get()` function does not return an error because its operation is
+guaranteed to work (unless there is some kind of system failure). If the key
+exists then it will return its byte slice value. If it doesn't exist then it
+will return `nil`. It's important to note that you can have a zero-length value
+set to a key which is different than the key not existing.
+
+Use the `Bucket.Delete()` function to delete a key from the bucket:
+
+```go
+db.Update(func (tx *bolt.Tx) error {
+    b := tx.Bucket([]byte("MyBucket"))
+    err := b.Delete([]byte("answer"))
+    return err
+})
+```
+
+This will delete the key `answers` from the bucket `MyBucket`.
+
+Please note that values returned from `Get()` are only valid while the
+transaction is open. If you need to use a value outside of the transaction
+then you must use `copy()` to copy it to another byte slice.
+
+
+### Autoincrementing integer for the bucket
+By using the `NextSequence()` function, you can let Bolt determine a sequence
+which can be used as the unique identifier for your key/value pairs. See the
+example below.
+
+```go
+// CreateUser saves u to the store. The new user ID is set on u once the data is persisted.
+func (s *Store) CreateUser(u *User) error {
+    return s.db.Update(func(tx *bolt.Tx) error {
+        // Retrieve the users bucket.
+        // This should be created when the DB is first opened.
+        b := tx.Bucket([]byte("users"))
+
+        // Generate ID for the user.
+        // This returns an error only if the Tx is closed or not writeable.
+        // That can't happen in an Update() call so I ignore the error check.
+        id, _ := b.NextSequence()
+        u.ID = int(id)
+
+        // Marshal user data into bytes.
+        buf, err := json.Marshal(u)
+        if err != nil {
+            return err
+        }
+
+        // Persist bytes to users bucket.
+        return b.Put(itob(u.ID), buf)
+    })
+}
+
+// itob returns an 8-byte big endian representation of v.
+func itob(v int) []byte {
+    b := make([]byte, 8)
+    binary.BigEndian.PutUint64(b, uint64(v))
+    return b
+}
+
+type User struct {
+    ID int
+    ...
+}
+```
+
+### Iterating over keys
+
+Bolt stores its keys in byte-sorted order within a bucket. This makes sequential
+iteration over these keys extremely fast. To iterate over keys we'll use a
+`Cursor`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	c := b.Cursor()
+
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+The cursor allows you to move to a specific point in the list of keys and move
+forward or backward through the keys one at a time.
+
+The following functions are available on the cursor:
+
+```
+First()  Move to the first key.
+Last()   Move to the last key.
+Seek()   Move to a specific key.
+Next()   Move to the next key.
+Prev()   Move to the previous key.
+```
+
+Each of those functions has a return signature of `(key []byte, value []byte)`.
+You must seek to a position using `First()`, `Last()`, or `Seek()` before calling
+`Next()` or `Prev()`. If you do not seek to a position then these functions will
+return a `nil` key.
+
+When you have iterated to the end of the cursor, then `Next()` will return a
+`nil` key and the cursor still points to the last element if present. When you
+have iterated to the beginning of the cursor, then `Prev()` will return a `nil`
+key and the cursor still points to the first element if present.
+
+If you remove key/value pairs during iteration, the cursor may automatically
+move to the next position if present in current node each time removing a key.
+When you call `c.Next()` after removing a key, it may skip one key/value pair.
+Refer to [pull/611](https://github.com/etcd-io/bbolt/pull/611) to get more detailed info.
+
+During iteration, if the key is non-`nil` but the value is `nil`, that means
+the key refers to a bucket rather than a value.  Use `Bucket.Bucket()` to
+access the sub-bucket.
+
+
+#### Prefix scans
+
+To iterate over a key prefix, you can combine `Seek()` and `bytes.HasPrefix()`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	c := tx.Bucket([]byte("MyBucket")).Cursor()
+
+	prefix := []byte("1234")
+	for k, v := c.Seek(prefix); k != nil && bytes.HasPrefix(k, prefix); k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+#### Range scans
+
+Another common use case is scanning over a range such as a time range. If you
+use a sortable time encoding such as RFC3339 then you can query a specific
+date range like this:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume our events bucket exists and has RFC3339 encoded time keys.
+	c := tx.Bucket([]byte("Events")).Cursor()
+
+	// Our time range spans the 90's decade.
+	min := []byte("1990-01-01T00:00:00Z")
+	max := []byte("2000-01-01T00:00:00Z")
+
+	// Iterate over the 90's.
+	for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) <= 0; k, v = c.Next() {
+		fmt.Printf("%s: %s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+Note that, while RFC3339 is sortable, the Golang implementation of RFC3339Nano does not use a fixed number of digits after the decimal point and is therefore not sortable.
+
+
+#### ForEach()
+
+You can also use the function `ForEach()` if you know you'll be iterating over
+all the keys in a bucket:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	b.ForEach(func(k, v []byte) error {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+		return nil
+	})
+	return nil
+})
+```
+
+Please note that keys and values in `ForEach()` are only valid while
+the transaction is open. If you need to use a key or value outside of
+the transaction, you must use `copy()` to copy it to another byte
+slice.
+
+### Nested buckets
+
+You can also store a bucket in a key to create nested buckets. The API is the
+same as the bucket management API on the `DB` object:
+
+```go
+func (*Bucket) CreateBucket(key []byte) (*Bucket, error)
+func (*Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error)
+func (*Bucket) DeleteBucket(key []byte) error
+```
+
+Say you had a multi-tenant application where the root level bucket was the account bucket. Inside of this bucket was a sequence of accounts which themselves are buckets. And inside the sequence bucket you could have many buckets pertaining to the Account itself (Users, Notes, etc) isolating the information into logical groupings.
+
+```go
+
+// createUser creates a new user in the given account.
+func createUser(accountID int, u *User) error {
+    // Start the transaction.
+    tx, err := db.Begin(true)
+    if err != nil {
+        return err
+    }
+    defer tx.Rollback()
+
+    // Retrieve the root bucket for the account.
+    // Assume this has already been created when the account was set up.
+    root := tx.Bucket([]byte(strconv.FormatUint(accountID, 10)))
+
+    // Setup the users bucket.
+    bkt, err := root.CreateBucketIfNotExists([]byte("USERS"))
+    if err != nil {
+        return err
+    }
+
+    // Generate an ID for the new user.
+    userID, err := bkt.NextSequence()
+    if err != nil {
+        return err
+    }
+    u.ID = userID
+
+    // Marshal and save the encoded user.
+    if buf, err := json.Marshal(u); err != nil {
+        return err
+    } else if err := bkt.Put([]byte(strconv.FormatUint(u.ID, 10)), buf); err != nil {
+        return err
+    }
+
+    // Commit the transaction.
+    if err := tx.Commit(); err != nil {
+        return err
+    }
+
+    return nil
+}
+
+```
+
+
+
+
+### Database backups
+
+Bolt is a single file so it's easy to backup. You can use the `Tx.WriteTo()`
+function to write a consistent view of the database to a writer. If you call
+this from a read-only transaction, it will perform a hot backup and not block
+your other database reads and writes.
+
+By default, it will use a regular file handle which will utilize the operating
+system's page cache. See the [`Tx`](https://godoc.org/go.etcd.io/bbolt#Tx)
+documentation for information about optimizing for larger-than-RAM datasets.
+
+One common use case is to backup over HTTP so you can use tools like `cURL` to
+do database backups:
+
+```go
+func BackupHandleFunc(w http.ResponseWriter, req *http.Request) {
+	err := db.View(func(tx *bolt.Tx) error {
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", `attachment; filename="my.db"`)
+		w.Header().Set("Content-Length", strconv.Itoa(int(tx.Size())))
+		_, err := tx.WriteTo(w)
+		return err
+	})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}
+```
+
+Then you can backup using this command:
+
+```sh
+$ curl http://localhost/backup > my.db
+```
+
+Or you can open your browser to `http://localhost/backup` and it will download
+automatically.
+
+If you want to backup to another file you can use the `Tx.CopyFile()` helper
+function.
+
+
+### Statistics
+
+The database keeps a running count of many of the internal operations it
+performs so you can better understand what's going on. By grabbing a snapshot
+of these stats at two points in time we can see what operations were performed
+in that time range.
+
+For example, we could start a goroutine to log stats every 10 seconds:
+
+```go
+go func() {
+	// Grab the initial stats.
+	prev := db.Stats()
+
+	for {
+		// Wait for 10s.
+		time.Sleep(10 * time.Second)
+
+		// Grab the current stats and diff them.
+		stats := db.Stats()
+		diff := stats.Sub(&prev)
+
+		// Encode stats to JSON and print to STDERR.
+		json.NewEncoder(os.Stderr).Encode(diff)
+
+		// Save stats for the next loop.
+		prev = stats
+	}
+}()
+```
+
+It's also useful to pipe these stats to a service such as statsd for monitoring
+or to provide an HTTP endpoint that will perform a fixed-length sample.
+
+
+### Read-Only Mode
+
+Sometimes it is useful to create a shared, read-only Bolt database. To this,
+set the `Options.ReadOnly` flag when opening your database. Read-only mode
+uses a shared lock to allow multiple processes to read from the database but
+it will block any processes from opening the database in read-write mode.
+
+```go
+db, err := bolt.Open("my.db", 0600, &bolt.Options{ReadOnly: true})
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+### Mobile Use (iOS/Android)
+
+Bolt is able to run on mobile devices by leveraging the binding feature of the
+[gomobile](https://github.com/golang/mobile) tool. Create a struct that will
+contain your database logic and a reference to a `*bolt.DB` with a initializing
+constructor that takes in a filepath where the database file will be stored.
+Neither Android nor iOS require extra permissions or cleanup from using this method.
+
+```go
+func NewBoltDB(filepath string) *BoltDB {
+	db, err := bolt.Open(filepath+"/demo.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &BoltDB{db}
+}
+
+type BoltDB struct {
+	db *bolt.DB
+	...
+}
+
+func (b *BoltDB) Path() string {
+	return b.db.Path()
+}
+
+func (b *BoltDB) Close() {
+	b.db.Close()
+}
+```
+
+Database logic should be defined as methods on this wrapper struct.
+
+To initialize this struct from the native language (both platforms now sync
+their local storage to the cloud. These snippets disable that functionality for the
+database file):
+
+#### Android
+
+```java
+String path;
+if (android.os.Build.VERSION.SDK_INT >=android.os.Build.VERSION_CODES.LOLLIPOP){
+    path = getNoBackupFilesDir().getAbsolutePath();
+} else{
+    path = getFilesDir().getAbsolutePath();
+}
+Boltmobiledemo.BoltDB boltDB = Boltmobiledemo.NewBoltDB(path)
+```
+
+#### iOS
+
+```objc
+- (void)demo {
+    NSString* path = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,
+                                                          NSUserDomainMask,
+                                                          YES) objectAtIndex:0];
+	GoBoltmobiledemoBoltDB * demo = GoBoltmobiledemoNewBoltDB(path);
+	[self addSkipBackupAttributeToItemAtPath:demo.path];
+	//Some DB Logic would go here
+	[demo close];
+}
+
+- (BOOL)addSkipBackupAttributeToItemAtPath:(NSString *) filePathString
+{
+    NSURL* URL= [NSURL fileURLWithPath: filePathString];
+    assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);
+
+    NSError *error = nil;
+    BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]
+                                  forKey: NSURLIsExcludedFromBackupKey error: &error];
+    if(!success){
+        NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error);
+    }
+    return success;
+}
+
+```
+
+## Resources
+
+For more information on getting started with Bolt, check out the following articles:
+
+* [Intro to BoltDB: Painless Performant Persistence](http://npf.io/2014/07/intro-to-boltdb-painless-performant-persistence/) by [Nate Finch](https://github.com/natefinch).
+* [Bolt -- an embedded key/value database for Go](https://www.progville.com/go/bolt-embedded-db-golang/) by Progville
+
+
+## Comparison with other databases
+
+### Postgres, MySQL, & other relational databases
+
+Relational databases structure data into rows and are only accessible through
+the use of SQL. This approach provides flexibility in how you store and query
+your data but also incurs overhead in parsing and planning SQL statements. Bolt
+accesses all data by a byte slice key. This makes Bolt fast to read and write
+data by key but provides no built-in support for joining values together.
+
+Most relational databases (with the exception of SQLite) are standalone servers
+that run separately from your application. This gives your systems
+flexibility to connect multiple application servers to a single database
+server but also adds overhead in serializing and transporting data over the
+network. Bolt runs as a library included in your application so all data access
+has to go through your application's process. This brings data closer to your
+application but limits multi-process access to the data.
+
+
+### LevelDB, RocksDB
+
+LevelDB and its derivatives (RocksDB, HyperLevelDB) are similar to Bolt in that
+they are libraries bundled into the application, however, their underlying
+structure is a log-structured merge-tree (LSM tree). An LSM tree optimizes
+random writes by using a write ahead log and multi-tiered, sorted files called
+SSTables. Bolt uses a B+tree internally and only a single file. Both approaches
+have trade-offs.
+
+If you require a high random write throughput (>10,000 w/sec) or you need to use
+spinning disks then LevelDB could be a good choice. If your application is
+read-heavy or does a lot of range scans then Bolt could be a good choice.
+
+One other important consideration is that LevelDB does not have transactions.
+It supports batch writing of key/values pairs and it supports read snapshots
+but it will not give you the ability to do a compare-and-swap operation safely.
+Bolt supports fully serializable ACID transactions.
+
+
+### LMDB
+
+Bolt was originally a port of LMDB so it is architecturally similar. Both use
+a B+tree, have ACID semantics with fully serializable transactions, and support
+lock-free MVCC using a single writer and multiple readers.
+
+The two projects have somewhat diverged. LMDB heavily focuses on raw performance
+while Bolt has focused on simplicity and ease of use. For example, LMDB allows
+several unsafe actions such as direct writes for the sake of performance. Bolt
+opts to disallow actions which can leave the database in a corrupted state. The
+only exception to this in Bolt is `DB.NoSync`.
+
+There are also a few differences in API. LMDB requires a maximum mmap size when
+opening an `mdb_env` whereas Bolt will handle incremental mmap resizing
+automatically. LMDB overloads the getter and setter functions with multiple
+flags whereas Bolt splits these specialized cases into their own functions.
+
+
+## Caveats & Limitations
+
+It's important to pick the right tool for the job and Bolt is no exception.
+Here are a few things to note when evaluating and using Bolt:
+
+* Bolt is good for read intensive workloads. Sequential write performance is
+  also fast but random writes can be slow. You can use `DB.Batch()` or add a
+  write-ahead log to help mitigate this issue.
+
+* Bolt uses a B+tree internally so there can be a lot of random page access.
+  SSDs provide a significant performance boost over spinning disks.
+
+* Try to avoid long running read transactions. Bolt uses copy-on-write so
+  old pages cannot be reclaimed while an old transaction is using them.
+
+* Byte slices returned from Bolt are only valid during a transaction. Once the
+  transaction has been committed or rolled back then the memory they point to
+  can be reused by a new page or can be unmapped from virtual memory and you'll
+  see an `unexpected fault address` panic when accessing it.
+
+* Bolt uses an exclusive write lock on the database file so it cannot be
+  shared by multiple processes.
+
+* Be careful when using `Bucket.FillPercent`. Setting a high fill percent for
+  buckets that have random inserts will cause your database to have very poor
+  page utilization.
+
+* Use larger buckets in general. Smaller buckets causes poor page utilization
+  once they become larger than the page size (typically 4KB).
+
+* Bulk loading a lot of random writes into a new bucket can be slow as the
+  page will not split until the transaction is committed. Randomly inserting
+  more than 100,000 key/value pairs into a single new bucket in a single
+  transaction is not advised.
+
+* Bolt uses a memory-mapped file so the underlying operating system handles the
+  caching of the data. Typically, the OS will cache as much of the file as it
+  can in memory and will release memory as needed to other processes. This means
+  that Bolt can show very high memory usage when working with large databases.
+  However, this is expected and the OS will release memory as needed. Bolt can
+  handle databases much larger than the available physical RAM, provided its
+  memory-map fits in the process virtual address space. It may be problematic
+  on 32-bits systems.
+
+* The data structures in the Bolt database are memory mapped so the data file
+  will be endian specific. This means that you cannot copy a Bolt file from a
+  little endian machine to a big endian machine and have it work. For most
+  users this is not a concern since most modern CPUs are little endian.
+
+* Because of the way pages are laid out on disk, Bolt cannot truncate data files
+  and return free pages back to the disk. Instead, Bolt maintains a free list
+  of unused pages within its data file. These free pages can be reused by later
+  transactions. This works well for many use cases as databases generally tend
+  to grow. However, it's important to note that deleting large chunks of data
+  will not allow you to reclaim that space on disk.
+
+* Removing key/values pairs in a bucket during iteration on the bucket using
+  cursor may not work properly. Each time when removing a key/value pair, the
+  cursor may automatically move to the next position if present. When users
+  call `c.Next()` after removing a key, it may skip one key/value pair.
+  Refer to https://github.com/etcd-io/bbolt/pull/611 for more detailed info.
+
+  For more information on page allocation, [see this comment][page-allocation].
+
+[page-allocation]: https://github.com/boltdb/bolt/issues/308#issuecomment-74811638
+
+
+## Reading the Source
+
+Bolt is a relatively small code base (<5KLOC) for an embedded, serializable,
+transactional key/value database so it can be a good starting point for people
+interested in how databases work.
+
+The best places to start are the main entry points into Bolt:
+
+- `Open()` - Initializes the reference to the database. It's responsible for
+  creating the database if it doesn't exist, obtaining an exclusive lock on the
+  file, reading the meta pages, & memory-mapping the file.
+
+- `DB.Begin()` - Starts a read-only or read-write transaction depending on the
+  value of the `writable` argument. This requires briefly obtaining the "meta"
+  lock to keep track of open transactions. Only one read-write transaction can
+  exist at a time so the "rwlock" is acquired during the life of a read-write
+  transaction.
+
+- `Bucket.Put()` - Writes a key/value pair into a bucket. After validating the
+  arguments, a cursor is used to traverse the B+tree to the page and position
+  where the key & value will be written. Once the position is found, the bucket
+  materializes the underlying page and the page's parent pages into memory as
+  "nodes". These nodes are where mutations occur during read-write transactions.
+  These changes get flushed to disk during commit.
+
+- `Bucket.Get()` - Retrieves a key/value pair from a bucket. This uses a cursor
+  to move to the page & position of a key/value pair. During a read-only
+  transaction, the key and value data is returned as a direct reference to the
+  underlying mmap file so there's no allocation overhead. For read-write
+  transactions, this data may reference the mmap file or one of the in-memory
+  node values.
+
+- `Cursor` - This object is simply for traversing the B+tree of on-disk pages
+  or in-memory nodes. It can seek to a specific key, move to the first or last
+  value, or it can move forward or backward. The cursor handles the movement up
+  and down the B+tree transparently to the end user.
+
+- `Tx.Commit()` - Converts the in-memory dirty nodes and the list of free pages
+  into pages to be written to disk. Writing to disk then occurs in two phases.
+  First, the dirty pages are written to disk and an `fsync()` occurs. Second, a
+  new meta page with an incremented transaction ID is written and another
+  `fsync()` occurs. This two phase write ensures that partially written data
+  pages are ignored in the event of a crash since the meta page pointing to them
+  is never written. Partially written meta pages are invalidated because they
+  are written with a checksum.
+
+If you have additional notes that could be helpful for others, please submit
+them via pull request.
+
+## Known Issues
+
+- bbolt might run into data corruption issue on Linux when the feature
+  [ext4: fast commit](https://lwn.net/Articles/842385/), which was introduced in
+  linux kernel version v5.10, is enabled. The fixes to the issue were included in
+  linux kernel version v5.17, please refer to links below,
+
+  * [ext4: fast commit may miss tracking unwritten range during ftruncate](https://lore.kernel.org/linux-ext4/20211223032337.5198-3-yinxin.x@bytedance.com/)
+  * [ext4: fast commit may not fallback for ineligible commit](https://lore.kernel.org/lkml/202201091544.W5HHEXAp-lkp@intel.com/T/#ma0768815e4b5f671e9e451d578256ef9a76fe30e)
+  * [ext4 updates for 5.17](https://lore.kernel.org/lkml/YdyxjTFaLWif6BCM@mit.edu/)
+
+  Please also refer to the discussion in https://github.com/etcd-io/bbolt/issues/562.
+
+- Writing a value with a length of 0 will always result in reading back an empty `[]byte{}` value.
+  Please refer to [issues/726#issuecomment-2061694802](https://github.com/etcd-io/bbolt/issues/726#issuecomment-2061694802).
+
+## Other Projects Using Bolt
+
+Below is a list of public, open source projects that use Bolt:
+
+* [Algernon](https://github.com/xyproto/algernon) - A HTTP/2 web server with built-in support for Lua. Uses BoltDB as the default database backend.
+* [Bazil](https://bazil.org/) - A file system that lets your data reside where it is most convenient for it to reside.
+* [bolter](https://github.com/hasit/bolter) - Command-line app for viewing BoltDB file in your terminal.
+* [boltcli](https://github.com/spacewander/boltcli) - the redis-cli for boltdb with Lua script support.
+* [BoltHold](https://github.com/timshannon/bolthold) - An embeddable NoSQL store for Go types built on BoltDB
+* [BoltStore](https://github.com/yosssi/boltstore) - Session store using Bolt.
+* [Boltdb Boilerplate](https://github.com/bobintornado/boltdb-boilerplate) - Boilerplate wrapper around bolt aiming to make simple calls one-liners.
+* [BoltDbWeb](https://github.com/evnix/boltdbweb) - A web based GUI for BoltDB files.
+* [BoltDB Viewer](https://github.com/zc310/rich_boltdb) - A BoltDB Viewer Can run on Windows、Linux、Android system.
+* [bleve](http://www.blevesearch.com/) - A pure Go search engine similar to ElasticSearch that uses Bolt as the default storage backend.
+* [bstore](https://github.com/mjl-/bstore) - Database library storing Go values, with referential/unique/nonzero constraints, indices, automatic schema management with struct tags, and a query API.
+* [btcwallet](https://github.com/btcsuite/btcwallet) - A bitcoin wallet.
+* [buckets](https://github.com/joyrexus/buckets) - a bolt wrapper streamlining
+  simple tx and key scans.
+* [Buildkit](https://github.com/moby/buildkit) - concurrent, cache-efficient, and Dockerfile-agnostic builder toolkit
+* [cayley](https://github.com/google/cayley) - Cayley is an open-source graph database using Bolt as optional backend.
+* [ChainStore](https://github.com/pressly/chainstore) - Simple key-value interface to a variety of storage engines organized as a chain of operations.
+* [🌰 Chestnut](https://github.com/jrapoport/chestnut) - Chestnut is encrypted storage for Go.
+* [Consul](https://github.com/hashicorp/consul) - Consul is service discovery and configuration made easy. Distributed, highly available, and datacenter-aware.
+* [Containerd](https://github.com/containerd/containerd) - An open and reliable container runtime
+* [DVID](https://github.com/janelia-flyem/dvid) - Added Bolt as optional storage engine and testing it against Basho-tuned leveldb.
+* [dcrwallet](https://github.com/decred/dcrwallet) - A wallet for the Decred cryptocurrency.
+* [drive](https://github.com/odeke-em/drive) - drive is an unofficial Google Drive command line client for \*NIX operating systems.
+* [event-shuttle](https://github.com/sclasen/event-shuttle) - A Unix system service to collect and reliably deliver messages to Kafka.
+* [Freehold](http://tshannon.bitbucket.org/freehold/) - An open, secure, and lightweight platform for your files and data.
+* [Go Report Card](https://goreportcard.com/) - Go code quality report cards as a (free and open source) service.
+* [GoWebApp](https://github.com/josephspurrier/gowebapp) - A basic MVC web application in Go using BoltDB.
+* [GoShort](https://github.com/pankajkhairnar/goShort) - GoShort is a URL shortener written in Golang and BoltDB for persistent key/value storage and for routing it's using high performent HTTPRouter.
+* [gopherpit](https://github.com/gopherpit/gopherpit) - A web service to manage Go remote import paths with custom domains
+* [gokv](https://github.com/philippgille/gokv) - Simple key-value store abstraction and implementations for Go (Redis, Consul, etcd, bbolt, BadgerDB, LevelDB, Memcached, DynamoDB, S3, PostgreSQL, MongoDB, CockroachDB and many more)
+* [Gitchain](https://github.com/gitchain/gitchain) - Decentralized, peer-to-peer Git repositories aka "Git meets Bitcoin".
+* [InfluxDB](https://influxdata.com) - Scalable datastore for metrics, events, and real-time analytics.
+* [ipLocator](https://github.com/AndreasBriese/ipLocator) - A fast ip-geo-location-server using bolt with bloom filters.
+* [ipxed](https://github.com/kelseyhightower/ipxed) - Web interface and api for ipxed.
+* [Ironsmith](https://github.com/timshannon/ironsmith) - A simple, script-driven continuous integration (build - > test -> release) tool, with no external dependencies
+* [Kala](https://github.com/ajvb/kala) - Kala is a modern job scheduler optimized to run on a single node. It is persistent, JSON over HTTP API, ISO 8601 duration notation, and dependent jobs.
+* [Key Value Access Language (KVAL)](https://github.com/kval-access-language) - A proposed grammar for key-value datastores offering a bbolt binding.
+* [LedisDB](https://github.com/siddontang/ledisdb) - A high performance NoSQL, using Bolt as optional storage.
+* [lru](https://github.com/crowdriff/lru) - Easy to use Bolt-backed Least-Recently-Used (LRU) read-through cache with chainable remote stores.
+* [mbuckets](https://github.com/abhigupta912/mbuckets) - A Bolt wrapper that allows easy operations on multi level (nested) buckets.
+* [MetricBase](https://github.com/msiebuhr/MetricBase) - Single-binary version of Graphite.
+* [MuLiFS](https://github.com/dankomiocevic/mulifs) - Music Library Filesystem creates a filesystem to organise your music files.
+* [NATS](https://github.com/nats-io/nats-streaming-server) - NATS Streaming uses bbolt for message and metadata storage.
+* [Portainer](https://github.com/portainer/portainer) - A lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments.
+* [Prometheus Annotation Server](https://github.com/oliver006/prom_annotation_server) - Annotation server for PromDash & Prometheus service monitoring system.
+* [Rain](https://github.com/cenkalti/rain) - BitTorrent client and library.
+* [reef-pi](https://github.com/reef-pi/reef-pi) - reef-pi is an award winning, modular, DIY reef tank controller using easy to learn electronics based on a Raspberry Pi.
+* [Request Baskets](https://github.com/darklynx/request-baskets) - A web service to collect arbitrary HTTP requests and inspect them via REST API or simple web UI, similar to [RequestBin](http://requestb.in/) service
+* [Seaweed File System](https://github.com/chrislusf/seaweedfs) - Highly scalable distributed key~file system with O(1) disk read.
+* [stow](https://github.com/djherbis/stow) -  a persistence manager for objects
+  backed by boltdb.
+* [Storm](https://github.com/asdine/storm) - Simple and powerful ORM for BoltDB.
+* [SimpleBolt](https://github.com/xyproto/simplebolt) - A simple way to use BoltDB. Deals mainly with strings.
+* [Skybox Analytics](https://github.com/skybox/skybox) - A standalone funnel analysis tool for web analytics.
+* [Scuttlebutt](https://github.com/benbjohnson/scuttlebutt) - Uses Bolt to store and process all Twitter mentions of GitHub projects.
+* [tentacool](https://github.com/optiflows/tentacool) - REST api server to manage system stuff (IP, DNS, Gateway...) on a linux server.
+* [torrent](https://github.com/anacrolix/torrent) - Full-featured BitTorrent client package and utilities in Go. BoltDB is a storage backend in development.
+* [Wiki](https://github.com/peterhellberg/wiki) - A tiny wiki using Goji, BoltDB and Blackfriday.
+
+If you are using Bolt in a project please send a pull request to add it to the list.
diff --git a/vendor/go.etcd.io/bbolt/bolt_aix.go b/vendor/go.etcd.io/bbolt/bolt_aix.go
new file mode 100644
index 0000000..596e540
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_aix.go
@@ -0,0 +1,92 @@
+//go:build aix
+
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	var lockType int16
+	if exclusive {
+		lockType = syscall.F_WRLCK
+	} else {
+		lockType = syscall.F_RDLCK
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		lock := syscall.Flock_t{Type: lockType}
+		err := syscall.FcntlFlock(fd, syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[common.MaxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_android.go b/vendor/go.etcd.io/bbolt/bolt_android.go
new file mode 100644
index 0000000..ac64fcf
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_android.go
@@ -0,0 +1,92 @@
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	var lockType int16
+	if exclusive {
+		lockType = syscall.F_WRLCK
+	} else {
+		lockType = syscall.F_RDLCK
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		lock := syscall.Flock_t{Type: lockType}
+		err := syscall.FcntlFlock(fd, syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	err = unix.Madvise(b, syscall.MADV_RANDOM)
+	if err != nil && err != syscall.ENOSYS {
+		// Ignore not implemented error in kernel because it still works.
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[common.MaxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_linux.go b/vendor/go.etcd.io/bbolt/bolt_linux.go
new file mode 100644
index 0000000..7707bca
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_linux.go
@@ -0,0 +1,10 @@
+package bbolt
+
+import (
+	"syscall"
+)
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return syscall.Fdatasync(int(db.file.Fd()))
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_openbsd.go b/vendor/go.etcd.io/bbolt/bolt_openbsd.go
new file mode 100644
index 0000000..bf47aa1
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_openbsd.go
@@ -0,0 +1,16 @@
+package bbolt
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func msync(db *DB) error {
+	return unix.Msync(db.data[:db.datasz], unix.MS_INVALIDATE)
+}
+
+func fdatasync(db *DB) error {
+	if db.data != nil {
+		return msync(db)
+	}
+	return db.file.Sync()
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_solaris.go b/vendor/go.etcd.io/bbolt/bolt_solaris.go
new file mode 100644
index 0000000..56b2cca
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_solaris.go
@@ -0,0 +1,90 @@
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	var lockType int16
+	if exclusive {
+		lockType = syscall.F_WRLCK
+	} else {
+		lockType = syscall.F_RDLCK
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		lock := syscall.Flock_t{Type: lockType}
+		err := syscall.FcntlFlock(fd, syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[common.MaxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_unix.go b/vendor/go.etcd.io/bbolt/bolt_unix.go
new file mode 100644
index 0000000..f68e721
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_unix.go
@@ -0,0 +1,89 @@
+//go:build !windows && !plan9 && !solaris && !aix && !android
+
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	flag := syscall.LOCK_NB
+	if exclusive {
+		flag |= syscall.LOCK_EX
+	} else {
+		flag |= syscall.LOCK_SH
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		err := syscall.Flock(int(fd), flag)
+		if err == nil {
+			return nil
+		} else if err != syscall.EWOULDBLOCK {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return errors.ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	return syscall.Flock(int(db.file.Fd()), syscall.LOCK_UN)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	err = unix.Madvise(b, syscall.MADV_RANDOM)
+	if err != nil && err != syscall.ENOSYS {
+		// Ignore not implemented error in kernel because it still works.
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[common.MaxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_windows.go b/vendor/go.etcd.io/bbolt/bolt_windows.go
new file mode 100644
index 0000000..e99a0d6
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_windows.go
@@ -0,0 +1,120 @@
+package bbolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+
+	"go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	var flags uint32 = windows.LOCKFILE_FAIL_IMMEDIATELY
+	if exclusive {
+		flags |= windows.LOCKFILE_EXCLUSIVE_LOCK
+	}
+	for {
+		// Fix for https://github.com/etcd-io/bbolt/issues/121. Use byte-range
+		// -1..0 as the lock on the database file.
+		var m1 uint32 = (1 << 32) - 1 // -1 in a uint32
+		err := windows.LockFileEx(windows.Handle(db.file.Fd()), flags, 0, 1, 0, &windows.Overlapped{
+			Offset:     m1,
+			OffsetHigh: m1,
+		})
+
+		if err == nil {
+			return nil
+		} else if err != windows.ERROR_LOCK_VIOLATION {
+			return err
+		}
+
+		// If we timed oumercit then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return errors.ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var m1 uint32 = (1 << 32) - 1 // -1 in a uint32
+	return windows.UnlockFileEx(windows.Handle(db.file.Fd()), 0, 1, 0, &windows.Overlapped{
+		Offset:     m1,
+		OffsetHigh: m1,
+	})
+}
+
+// mmap memory maps a DB's data file.
+// Based on: https://github.com/edsrzf/mmap-go
+func mmap(db *DB, sz int) error {
+	var sizelo, sizehi uint32
+
+	if !db.readOnly {
+		// Truncate the database to the size of the mmap.
+		if err := db.file.Truncate(int64(sz)); err != nil {
+			return fmt.Errorf("truncate: %s", err)
+		}
+		sizehi = uint32(sz >> 32)
+		sizelo = uint32(sz)
+	}
+
+	// Open a file mapping handle.
+	h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizehi, sizelo, nil)
+	if h == 0 {
+		return os.NewSyscallError("CreateFileMapping", errno)
+	}
+
+	// Create the memory map.
+	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, 0)
+	if addr == 0 {
+		// Do our best and report error returned from MapViewOfFile.
+		_ = syscall.CloseHandle(h)
+		return os.NewSyscallError("MapViewOfFile", errno)
+	}
+
+	// Close mapping handle.
+	if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
+		return os.NewSyscallError("CloseHandle", err)
+	}
+
+	// Convert to a byte array.
+	db.data = (*[common.MaxMapSize]byte)(unsafe.Pointer(addr))
+	db.datasz = sz
+
+	return nil
+}
+
+// munmap unmaps a pointer from a file.
+// Based on: https://github.com/edsrzf/mmap-go
+func munmap(db *DB) error {
+	if db.data == nil {
+		return nil
+	}
+
+	addr := (uintptr)(unsafe.Pointer(&db.data[0]))
+	var err1 error
+	if err := syscall.UnmapViewOfFile(addr); err != nil {
+		err1 = os.NewSyscallError("UnmapViewOfFile", err)
+	}
+	db.data = nil
+	db.datasz = 0
+	return err1
+}
diff --git a/vendor/go.etcd.io/bbolt/boltsync_unix.go b/vendor/go.etcd.io/bbolt/boltsync_unix.go
new file mode 100644
index 0000000..27face7
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/boltsync_unix.go
@@ -0,0 +1,8 @@
+//go:build !windows && !plan9 && !linux && !openbsd
+
+package bbolt
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}
diff --git a/vendor/go.etcd.io/bbolt/bucket.go b/vendor/go.etcd.io/bbolt/bucket.go
new file mode 100644
index 0000000..6371ace
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bucket.go
@@ -0,0 +1,1005 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"unsafe"
+
+	"go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+)
+
+const (
+	// MaxKeySize is the maximum length of a key, in bytes.
+	MaxKeySize = 32768
+
+	// MaxValueSize is the maximum length of a value, in bytes.
+	MaxValueSize = (1 << 31) - 2
+)
+
+const (
+	minFillPercent = 0.1
+	maxFillPercent = 1.0
+)
+
+// DefaultFillPercent is the percentage that split pages are filled.
+// This value can be changed by setting Bucket.FillPercent.
+const DefaultFillPercent = 0.5
+
+// Bucket represents a collection of key/value pairs inside the database.
+type Bucket struct {
+	*common.InBucket
+	tx       *Tx                   // the associated transaction
+	buckets  map[string]*Bucket    // subbucket cache
+	page     *common.Page          // inline page reference
+	rootNode *node                 // materialized node for the root page.
+	nodes    map[common.Pgid]*node // node cache
+
+	// Sets the threshold for filling nodes when they split. By default,
+	// the bucket will fill to 50% but it can be useful to increase this
+	// amount if you know that your write workloads are mostly append-only.
+	//
+	// This is non-persisted across transactions so it must be set in every Tx.
+	FillPercent float64
+}
+
+// newBucket returns a new bucket associated with a transaction.
+func newBucket(tx *Tx) Bucket {
+	var b = Bucket{tx: tx, FillPercent: DefaultFillPercent}
+	if tx.writable {
+		b.buckets = make(map[string]*Bucket)
+		b.nodes = make(map[common.Pgid]*node)
+	}
+	return b
+}
+
+// Tx returns the tx of the bucket.
+func (b *Bucket) Tx() *Tx {
+	return b.tx
+}
+
+// Root returns the root of the bucket.
+func (b *Bucket) Root() common.Pgid {
+	return b.RootPage()
+}
+
+// Writable returns whether the bucket is writable.
+func (b *Bucket) Writable() bool {
+	return b.tx.writable
+}
+
+// Cursor creates a cursor associated with the bucket.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (b *Bucket) Cursor() *Cursor {
+	// Update transaction statistics.
+	b.tx.stats.IncCursorCount(1)
+
+	// Allocate and return a cursor.
+	return &Cursor{
+		bucket: b,
+		stack:  make([]elemRef, 0),
+	}
+}
+
+// Bucket retrieves a nested bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) Bucket(name []byte) *Bucket {
+	if b.buckets != nil {
+		if child := b.buckets[string(name)]; child != nil {
+			return child
+		}
+	}
+
+	// Move cursor to key.
+	c := b.Cursor()
+	k, v, flags := c.seek(name)
+
+	// Return nil if the key doesn't exist or it is not a bucket.
+	if !bytes.Equal(name, k) || (flags&common.BucketLeafFlag) == 0 {
+		return nil
+	}
+
+	// Otherwise create a bucket and cache it.
+	var child = b.openBucket(v)
+	if b.buckets != nil {
+		b.buckets[string(name)] = child
+	}
+
+	return child
+}
+
+// Helper method that re-interprets a sub-bucket value
+// from a parent into a Bucket
+func (b *Bucket) openBucket(value []byte) *Bucket {
+	var child = newBucket(b.tx)
+
+	// Unaligned access requires a copy to be made.
+	const unalignedMask = unsafe.Alignof(struct {
+		common.InBucket
+		common.Page
+	}{}) - 1
+	unaligned := uintptr(unsafe.Pointer(&value[0]))&unalignedMask != 0
+	if unaligned {
+		value = cloneBytes(value)
+	}
+
+	// If this is a writable transaction then we need to copy the bucket entry.
+	// Read-only transactions can point directly at the mmap entry.
+	if b.tx.writable && !unaligned {
+		child.InBucket = &common.InBucket{}
+		*child.InBucket = *(*common.InBucket)(unsafe.Pointer(&value[0]))
+	} else {
+		child.InBucket = (*common.InBucket)(unsafe.Pointer(&value[0]))
+	}
+
+	// Save a reference to the inline page if the bucket is inline.
+	if child.RootPage() == 0 {
+		child.page = (*common.Page)(unsafe.Pointer(&value[common.BucketHeaderSize]))
+	}
+
+	return &child
+}
+
+// CreateBucket creates a new bucket at the given key and returns the new bucket.
+// Returns an error if the key already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucket(key []byte) (rb *Bucket, err error) {
+	if lg := b.tx.db.Logger(); lg != discardLogger {
+		lg.Debugf("Creating bucket %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Creating bucket %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Creating bucket %q successfully", key)
+			}
+		}()
+	}
+	if b.tx.db == nil {
+		return nil, errors.ErrTxClosed
+	} else if !b.tx.writable {
+		return nil, errors.ErrTxNotWritable
+	} else if len(key) == 0 {
+		return nil, errors.ErrBucketNameRequired
+	}
+
+	// Insert into node.
+	// Tip: Use a new variable `newKey` instead of reusing the existing `key` to prevent
+	// it from being marked as leaking, and accordingly cannot be allocated on stack.
+	newKey := cloneBytes(key)
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(newKey)
+
+	// Return an error if there is an existing key.
+	if bytes.Equal(newKey, k) {
+		if (flags & common.BucketLeafFlag) != 0 {
+			return nil, errors.ErrBucketExists
+		}
+		return nil, errors.ErrIncompatibleValue
+	}
+
+	// Create empty, inline bucket.
+	var bucket = Bucket{
+		InBucket:    &common.InBucket{},
+		rootNode:    &node{isLeaf: true},
+		FillPercent: DefaultFillPercent,
+	}
+	var value = bucket.write()
+
+	c.node().put(newKey, newKey, value, 0, common.BucketLeafFlag)
+
+	// Since subbuckets are not allowed on inline buckets, we need to
+	// dereference the inline page, if it exists. This will cause the bucket
+	// to be treated as a regular, non-inline bucket for the rest of the tx.
+	b.page = nil
+
+	return b.Bucket(newKey), nil
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist and returns a reference to it.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucketIfNotExists(key []byte) (rb *Bucket, err error) {
+	if lg := b.tx.db.Logger(); lg != discardLogger {
+		lg.Debugf("Creating bucket if not exist %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Creating bucket if not exist %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Creating bucket if not exist %q successfully", key)
+			}
+		}()
+	}
+
+	if b.tx.db == nil {
+		return nil, errors.ErrTxClosed
+	} else if !b.tx.writable {
+		return nil, errors.ErrTxNotWritable
+	} else if len(key) == 0 {
+		return nil, errors.ErrBucketNameRequired
+	}
+
+	// Insert into node.
+	// Tip: Use a new variable `newKey` instead of reusing the existing `key` to prevent
+	// it from being marked as leaking, and accordingly cannot be allocated on stack.
+	newKey := cloneBytes(key)
+
+	if b.buckets != nil {
+		if child := b.buckets[string(newKey)]; child != nil {
+			return child, nil
+		}
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, v, flags := c.seek(newKey)
+
+	// Return an error if there is an existing non-bucket key.
+	if bytes.Equal(newKey, k) {
+		if (flags & common.BucketLeafFlag) != 0 {
+			var child = b.openBucket(v)
+			if b.buckets != nil {
+				b.buckets[string(newKey)] = child
+			}
+
+			return child, nil
+		}
+		return nil, errors.ErrIncompatibleValue
+	}
+
+	// Create empty, inline bucket.
+	var bucket = Bucket{
+		InBucket:    &common.InBucket{},
+		rootNode:    &node{isLeaf: true},
+		FillPercent: DefaultFillPercent,
+	}
+	var value = bucket.write()
+
+	c.node().put(newKey, newKey, value, 0, common.BucketLeafFlag)
+
+	// Since subbuckets are not allowed on inline buckets, we need to
+	// dereference the inline page, if it exists. This will cause the bucket
+	// to be treated as a regular, non-inline bucket for the rest of the tx.
+	b.page = nil
+
+	return b.Bucket(newKey), nil
+}
+
+// DeleteBucket deletes a bucket at the given key.
+// Returns an error if the bucket does not exist, or if the key represents a non-bucket value.
+func (b *Bucket) DeleteBucket(key []byte) (err error) {
+	if lg := b.tx.db.Logger(); lg != discardLogger {
+		lg.Debugf("Deleting bucket %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Deleting bucket %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Deleting bucket %q successfully", key)
+			}
+		}()
+	}
+
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !b.Writable() {
+		return errors.ErrTxNotWritable
+	}
+
+	newKey := cloneBytes(key)
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(newKey)
+
+	// Return an error if bucket doesn't exist or is not a bucket.
+	if !bytes.Equal(newKey, k) {
+		return errors.ErrBucketNotFound
+	} else if (flags & common.BucketLeafFlag) == 0 {
+		return errors.ErrIncompatibleValue
+	}
+
+	// Recursively delete all child buckets.
+	child := b.Bucket(newKey)
+	err = child.ForEachBucket(func(k []byte) error {
+		if err := child.DeleteBucket(k); err != nil {
+			return fmt.Errorf("delete bucket: %s", err)
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// Remove cached copy.
+	delete(b.buckets, string(newKey))
+
+	// Release all bucket pages to freelist.
+	child.nodes = nil
+	child.rootNode = nil
+	child.free()
+
+	// Delete the node if we have a matching key.
+	c.node().del(newKey)
+
+	return nil
+}
+
+// MoveBucket moves a sub-bucket from the source bucket to the destination bucket.
+// Returns an error if
+//  1. the sub-bucket cannot be found in the source bucket;
+//  2. or the key already exists in the destination bucket;
+//  3. or the key represents a non-bucket value;
+//  4. the source and destination buckets are the same.
+func (b *Bucket) MoveBucket(key []byte, dstBucket *Bucket) (err error) {
+	lg := b.tx.db.Logger()
+	if lg != discardLogger {
+		lg.Debugf("Moving bucket %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Moving bucket %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Moving bucket %q successfully", key)
+			}
+		}()
+	}
+
+	if b.tx.db == nil || dstBucket.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !b.Writable() || !dstBucket.Writable() {
+		return errors.ErrTxNotWritable
+	}
+
+	if b.tx.db.Path() != dstBucket.tx.db.Path() || b.tx != dstBucket.tx {
+		lg.Errorf("The source and target buckets are not in the same db file, source bucket in %s and target bucket in %s", b.tx.db.Path(), dstBucket.tx.db.Path())
+		return errors.ErrDifferentDB
+	}
+
+	newKey := cloneBytes(key)
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, v, flags := c.seek(newKey)
+
+	// Return an error if bucket doesn't exist or is not a bucket.
+	if !bytes.Equal(newKey, k) {
+		return errors.ErrBucketNotFound
+	} else if (flags & common.BucketLeafFlag) == 0 {
+		lg.Errorf("An incompatible key %s exists in the source bucket", newKey)
+		return errors.ErrIncompatibleValue
+	}
+
+	// Do nothing (return true directly) if the source bucket and the
+	// destination bucket are actually the same bucket.
+	if b == dstBucket || (b.RootPage() == dstBucket.RootPage() && b.RootPage() != 0) {
+		lg.Errorf("The source bucket (%s) and the target bucket (%s) are the same bucket", b, dstBucket)
+		return errors.ErrSameBuckets
+	}
+
+	// check whether the key already exists in the destination bucket
+	curDst := dstBucket.Cursor()
+	k, _, flags = curDst.seek(newKey)
+
+	// Return an error if there is an existing key in the destination bucket.
+	if bytes.Equal(newKey, k) {
+		if (flags & common.BucketLeafFlag) != 0 {
+			return errors.ErrBucketExists
+		}
+		lg.Errorf("An incompatible key %s exists in the target bucket", newKey)
+		return errors.ErrIncompatibleValue
+	}
+
+	// remove the sub-bucket from the source bucket
+	delete(b.buckets, string(newKey))
+	c.node().del(newKey)
+
+	// add te sub-bucket to the destination bucket
+	newValue := cloneBytes(v)
+	curDst.node().put(newKey, newKey, newValue, 0, common.BucketLeafFlag)
+
+	return nil
+}
+
+// Inspect returns the structure of the bucket.
+func (b *Bucket) Inspect() BucketStructure {
+	return b.recursivelyInspect([]byte("root"))
+}
+
+func (b *Bucket) recursivelyInspect(name []byte) BucketStructure {
+	bs := BucketStructure{Name: string(name)}
+
+	keyN := 0
+	c := b.Cursor()
+	for k, _, flags := c.first(); k != nil; k, _, flags = c.next() {
+		if flags&common.BucketLeafFlag != 0 {
+			childBucket := b.Bucket(k)
+			childBS := childBucket.recursivelyInspect(k)
+			bs.Children = append(bs.Children, childBS)
+		} else {
+			keyN++
+		}
+	}
+	bs.KeyN = keyN
+
+	return bs
+}
+
+// Get retrieves the value for a key in the bucket.
+// Returns a nil value if the key does not exist or if the key is a nested bucket.
+// The returned value is only valid for the life of the transaction.
+// The returned memory is owned by bbolt and must never be modified; writing to this memory might corrupt the database.
+func (b *Bucket) Get(key []byte) []byte {
+	k, v, flags := b.Cursor().seek(key)
+
+	// Return nil if this is a bucket.
+	if (flags & common.BucketLeafFlag) != 0 {
+		return nil
+	}
+
+	// If our target node isn't the same key as what's passed in then return nil.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
+	return v
+}
+
+// Put sets the value for a key in the bucket.
+// If the key exist then its previous value will be overwritten.
+// Supplied value must remain valid for the life of the transaction.
+// Returns an error if the bucket was created from a read-only transaction, if the key is blank, if the key is too large, or if the value is too large.
+func (b *Bucket) Put(key []byte, value []byte) (err error) {
+	if lg := b.tx.db.Logger(); lg != discardLogger {
+		lg.Debugf("Putting key %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Putting key %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Putting key %q successfully", key)
+			}
+		}()
+	}
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !b.Writable() {
+		return errors.ErrTxNotWritable
+	} else if len(key) == 0 {
+		return errors.ErrKeyRequired
+	} else if len(key) > MaxKeySize {
+		return errors.ErrKeyTooLarge
+	} else if int64(len(value)) > MaxValueSize {
+		return errors.ErrValueTooLarge
+	}
+
+	// Insert into node.
+	// Tip: Use a new variable `newKey` instead of reusing the existing `key` to prevent
+	// it from being marked as leaking, and accordingly cannot be allocated on stack.
+	newKey := cloneBytes(key)
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(newKey)
+
+	// Return an error if there is an existing key with a bucket value.
+	if bytes.Equal(newKey, k) && (flags&common.BucketLeafFlag) != 0 {
+		return errors.ErrIncompatibleValue
+	}
+
+	// gofail: var beforeBucketPut struct{}
+
+	c.node().put(newKey, newKey, value, 0, 0)
+
+	return nil
+}
+
+// Delete removes a key from the bucket.
+// If the key does not exist then nothing is done and a nil error is returned.
+// Returns an error if the bucket was created from a read-only transaction.
+func (b *Bucket) Delete(key []byte) (err error) {
+	if lg := b.tx.db.Logger(); lg != discardLogger {
+		lg.Debugf("Deleting key %q", key)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Deleting key %q failed: %v", key, err)
+			} else {
+				lg.Debugf("Deleting key %q successfully", key)
+			}
+		}()
+	}
+
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !b.Writable() {
+		return errors.ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return nil if the key doesn't exist.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
+
+	// Return an error if there is already existing bucket value.
+	if (flags & common.BucketLeafFlag) != 0 {
+		return errors.ErrIncompatibleValue
+	}
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
+}
+
+// Sequence returns the current integer for the bucket without incrementing it.
+func (b *Bucket) Sequence() uint64 {
+	return b.InSequence()
+}
+
+// SetSequence updates the sequence number for the bucket.
+func (b *Bucket) SetSequence(v uint64) error {
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !b.Writable() {
+		return errors.ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.RootPage(), nil)
+	}
+
+	// Set the sequence.
+	b.SetInSequence(v)
+	return nil
+}
+
+// NextSequence returns an autoincrementing integer for the bucket.
+func (b *Bucket) NextSequence() (uint64, error) {
+	if b.tx.db == nil {
+		return 0, errors.ErrTxClosed
+	} else if !b.Writable() {
+		return 0, errors.ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.RootPage(), nil)
+	}
+
+	// Increment and return the sequence.
+	b.IncSequence()
+	return b.Sequence(), nil
+}
+
+// ForEach executes a function for each key/value pair in a bucket.
+// Because ForEach uses a Cursor, the iteration over keys is in lexicographical order.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller. The provided function must not modify
+// the bucket; this will result in undefined behavior.
+func (b *Bucket) ForEach(fn func(k, v []byte) error) error {
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	}
+	c := b.Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		if err := fn(k, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (b *Bucket) ForEachBucket(fn func(k []byte) error) error {
+	if b.tx.db == nil {
+		return errors.ErrTxClosed
+	}
+	c := b.Cursor()
+	for k, _, flags := c.first(); k != nil; k, _, flags = c.next() {
+		if flags&common.BucketLeafFlag != 0 {
+			if err := fn(k); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// Stats returns stats on a bucket.
+func (b *Bucket) Stats() BucketStats {
+	var s, subStats BucketStats
+	pageSize := b.tx.db.pageSize
+	s.BucketN += 1
+	if b.RootPage() == 0 {
+		s.InlineBucketN += 1
+	}
+	b.forEachPage(func(p *common.Page, depth int, pgstack []common.Pgid) {
+		if p.IsLeafPage() {
+			s.KeyN += int(p.Count())
+
+			// used totals the used bytes for the page
+			used := common.PageHeaderSize
+
+			if p.Count() != 0 {
+				// If page has any elements, add all element headers.
+				used += common.LeafPageElementSize * uintptr(p.Count()-1)
+
+				// Add all element key, value sizes.
+				// The computation takes advantage of the fact that the position
+				// of the last element's key/value equals to the total of the sizes
+				// of all previous elements' keys and values.
+				// It also includes the last element's header.
+				lastElement := p.LeafPageElement(p.Count() - 1)
+				used += uintptr(lastElement.Pos() + lastElement.Ksize() + lastElement.Vsize())
+			}
+
+			if b.RootPage() == 0 {
+				// For inlined bucket just update the inline stats
+				s.InlineBucketInuse += int(used)
+			} else {
+				// For non-inlined bucket update all the leaf stats
+				s.LeafPageN++
+				s.LeafInuse += int(used)
+				s.LeafOverflowN += int(p.Overflow())
+
+				// Collect stats from sub-buckets.
+				// Do that by iterating over all element headers
+				// looking for the ones with the bucketLeafFlag.
+				for i := uint16(0); i < p.Count(); i++ {
+					e := p.LeafPageElement(i)
+					if (e.Flags() & common.BucketLeafFlag) != 0 {
+						// For any bucket element, open the element value
+						// and recursively call Stats on the contained bucket.
+						subStats.Add(b.openBucket(e.Value()).Stats())
+					}
+				}
+			}
+		} else if p.IsBranchPage() {
+			s.BranchPageN++
+			lastElement := p.BranchPageElement(p.Count() - 1)
+
+			// used totals the used bytes for the page
+			// Add header and all element headers.
+			used := common.PageHeaderSize + (common.BranchPageElementSize * uintptr(p.Count()-1))
+
+			// Add size of all keys and values.
+			// Again, use the fact that last element's position equals to
+			// the total of key, value sizes of all previous elements.
+			used += uintptr(lastElement.Pos() + lastElement.Ksize())
+			s.BranchInuse += int(used)
+			s.BranchOverflowN += int(p.Overflow())
+		}
+
+		// Keep track of maximum page depth.
+		if depth+1 > s.Depth {
+			s.Depth = depth + 1
+		}
+	})
+
+	// Alloc stats can be computed from page counts and pageSize.
+	s.BranchAlloc = (s.BranchPageN + s.BranchOverflowN) * pageSize
+	s.LeafAlloc = (s.LeafPageN + s.LeafOverflowN) * pageSize
+
+	// Add the max depth of sub-buckets to get total nested depth.
+	s.Depth += subStats.Depth
+	// Add the stats for all sub-buckets
+	s.Add(subStats)
+	return s
+}
+
+// forEachPage iterates over every page in a bucket, including inline pages.
+func (b *Bucket) forEachPage(fn func(*common.Page, int, []common.Pgid)) {
+	// If we have an inline page then just use that.
+	if b.page != nil {
+		fn(b.page, 0, []common.Pgid{b.RootPage()})
+		return
+	}
+
+	// Otherwise traverse the page hierarchy.
+	b.tx.forEachPage(b.RootPage(), fn)
+}
+
+// forEachPageNode iterates over every page (or node) in a bucket.
+// This also includes inline pages.
+func (b *Bucket) forEachPageNode(fn func(*common.Page, *node, int)) {
+	// If we have an inline page or root node then just use that.
+	if b.page != nil {
+		fn(b.page, nil, 0)
+		return
+	}
+	b._forEachPageNode(b.RootPage(), 0, fn)
+}
+
+func (b *Bucket) _forEachPageNode(pgId common.Pgid, depth int, fn func(*common.Page, *node, int)) {
+	var p, n = b.pageNode(pgId)
+
+	// Execute function.
+	fn(p, n, depth)
+
+	// Recursively loop over children.
+	if p != nil {
+		if p.IsBranchPage() {
+			for i := 0; i < int(p.Count()); i++ {
+				elem := p.BranchPageElement(uint16(i))
+				b._forEachPageNode(elem.Pgid(), depth+1, fn)
+			}
+		}
+	} else {
+		if !n.isLeaf {
+			for _, inode := range n.inodes {
+				b._forEachPageNode(inode.Pgid(), depth+1, fn)
+			}
+		}
+	}
+}
+
+// spill writes all the nodes for this bucket to dirty pages.
+func (b *Bucket) spill() error {
+	// Spill all child buckets first.
+	for name, child := range b.buckets {
+		// If the child bucket is small enough and it has no child buckets then
+		// write it inline into the parent bucket's page. Otherwise spill it
+		// like a normal bucket and make the parent value a pointer to the page.
+		var value []byte
+		if child.inlineable() {
+			child.free()
+			value = child.write()
+		} else {
+			if err := child.spill(); err != nil {
+				return err
+			}
+
+			// Update the child bucket header in this bucket.
+			value = make([]byte, unsafe.Sizeof(common.InBucket{}))
+			var bucket = (*common.InBucket)(unsafe.Pointer(&value[0]))
+			*bucket = *child.InBucket
+		}
+
+		// Skip writing the bucket if there are no materialized nodes.
+		if child.rootNode == nil {
+			continue
+		}
+
+		// Update parent node.
+		var c = b.Cursor()
+		k, _, flags := c.seek([]byte(name))
+		if !bytes.Equal([]byte(name), k) {
+			panic(fmt.Sprintf("misplaced bucket header: %x -> %x", []byte(name), k))
+		}
+		if flags&common.BucketLeafFlag == 0 {
+			panic(fmt.Sprintf("unexpected bucket header flag: %x", flags))
+		}
+		c.node().put([]byte(name), []byte(name), value, 0, common.BucketLeafFlag)
+	}
+
+	// Ignore if there's not a materialized root node.
+	if b.rootNode == nil {
+		return nil
+	}
+
+	// Spill nodes.
+	if err := b.rootNode.spill(); err != nil {
+		return err
+	}
+	b.rootNode = b.rootNode.root()
+
+	// Update the root node for this bucket.
+	if b.rootNode.pgid >= b.tx.meta.Pgid() {
+		panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", b.rootNode.pgid, b.tx.meta.Pgid()))
+	}
+	b.SetRootPage(b.rootNode.pgid)
+
+	return nil
+}
+
+// inlineable returns true if a bucket is small enough to be written inline
+// and if it contains no subbuckets. Otherwise, returns false.
+func (b *Bucket) inlineable() bool {
+	var n = b.rootNode
+
+	// Bucket must only contain a single leaf node.
+	if n == nil || !n.isLeaf {
+		return false
+	}
+
+	// Bucket is not inlineable if it contains subbuckets or if it goes beyond
+	// our threshold for inline bucket size.
+	var size = common.PageHeaderSize
+	for _, inode := range n.inodes {
+		size += common.LeafPageElementSize + uintptr(len(inode.Key())) + uintptr(len(inode.Value()))
+
+		if inode.Flags()&common.BucketLeafFlag != 0 {
+			return false
+		} else if size > b.maxInlineBucketSize() {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Returns the maximum total size of a bucket to make it a candidate for inlining.
+func (b *Bucket) maxInlineBucketSize() uintptr {
+	return uintptr(b.tx.db.pageSize / 4)
+}
+
+// write allocates and writes a bucket to a byte slice.
+func (b *Bucket) write() []byte {
+	// Allocate the appropriate size.
+	var n = b.rootNode
+	var value = make([]byte, common.BucketHeaderSize+n.size())
+
+	// Write a bucket header.
+	var bucket = (*common.InBucket)(unsafe.Pointer(&value[0]))
+	*bucket = *b.InBucket
+
+	// Convert byte slice to a fake page and write the root node.
+	var p = (*common.Page)(unsafe.Pointer(&value[common.BucketHeaderSize]))
+	n.write(p)
+
+	return value
+}
+
+// rebalance attempts to balance all nodes.
+func (b *Bucket) rebalance() {
+	for _, n := range b.nodes {
+		n.rebalance()
+	}
+	for _, child := range b.buckets {
+		child.rebalance()
+	}
+}
+
+// node creates a node from a page and associates it with a given parent.
+func (b *Bucket) node(pgId common.Pgid, parent *node) *node {
+	common.Assert(b.nodes != nil, "nodes map expected")
+
+	// Retrieve node if it's already been created.
+	if n := b.nodes[pgId]; n != nil {
+		return n
+	}
+
+	// Otherwise create a node and cache it.
+	n := &node{bucket: b, parent: parent}
+	if parent == nil {
+		b.rootNode = n
+	} else {
+		parent.children = append(parent.children, n)
+	}
+
+	// Use the inline page if this is an inline bucket.
+	var p = b.page
+	if p == nil {
+		p = b.tx.page(pgId)
+	} else {
+		// if p isn't nil, then it's an inline bucket.
+		// The pgId must be 0 in this case.
+		common.Verify(func() {
+			common.Assert(pgId == 0, "The page ID (%d) isn't 0 for an inline bucket", pgId)
+		})
+	}
+
+	// Read the page into the node and cache it.
+	n.read(p)
+	b.nodes[pgId] = n
+
+	// Update statistics.
+	b.tx.stats.IncNodeCount(1)
+
+	return n
+}
+
+// free recursively frees all pages in the bucket.
+func (b *Bucket) free() {
+	if b.RootPage() == 0 {
+		return
+	}
+
+	var tx = b.tx
+	b.forEachPageNode(func(p *common.Page, n *node, _ int) {
+		if p != nil {
+			tx.db.freelist.Free(tx.meta.Txid(), p)
+		} else {
+			n.free()
+		}
+	})
+	b.SetRootPage(0)
+}
+
+// dereference removes all references to the old mmap.
+func (b *Bucket) dereference() {
+	if b.rootNode != nil {
+		b.rootNode.root().dereference()
+	}
+
+	for _, child := range b.buckets {
+		child.dereference()
+	}
+}
+
+// pageNode returns the in-memory node, if it exists.
+// Otherwise, returns the underlying page.
+func (b *Bucket) pageNode(id common.Pgid) (*common.Page, *node) {
+	// Inline buckets have a fake page embedded in their value so treat them
+	// differently. We'll return the rootNode (if available) or the fake page.
+	if b.RootPage() == 0 {
+		if id != 0 {
+			panic(fmt.Sprintf("inline bucket non-zero page access(2): %d != 0", id))
+		}
+		if b.rootNode != nil {
+			return nil, b.rootNode
+		}
+		return b.page, nil
+	}
+
+	// Check the node cache for non-inline buckets.
+	if b.nodes != nil {
+		if n := b.nodes[id]; n != nil {
+			return nil, n
+		}
+	}
+
+	// Finally lookup the page from the transaction if no node is materialized.
+	return b.tx.page(id), nil
+}
+
+// BucketStats records statistics about resources used by a bucket.
+type BucketStats struct {
+	// Page count statistics.
+	BranchPageN     int // number of logical branch pages
+	BranchOverflowN int // number of physical branch overflow pages
+	LeafPageN       int // number of logical leaf pages
+	LeafOverflowN   int // number of physical leaf overflow pages
+
+	// Tree statistics.
+	KeyN  int // number of keys/value pairs
+	Depth int // number of levels in B+tree
+
+	// Page size utilization.
+	BranchAlloc int // bytes allocated for physical branch pages
+	BranchInuse int // bytes actually used for branch data
+	LeafAlloc   int // bytes allocated for physical leaf pages
+	LeafInuse   int // bytes actually used for leaf data
+
+	// Bucket statistics
+	BucketN           int // total number of buckets including the top bucket
+	InlineBucketN     int // total number on inlined buckets
+	InlineBucketInuse int // bytes used for inlined buckets (also accounted for in LeafInuse)
+}
+
+func (s *BucketStats) Add(other BucketStats) {
+	s.BranchPageN += other.BranchPageN
+	s.BranchOverflowN += other.BranchOverflowN
+	s.LeafPageN += other.LeafPageN
+	s.LeafOverflowN += other.LeafOverflowN
+	s.KeyN += other.KeyN
+	if s.Depth < other.Depth {
+		s.Depth = other.Depth
+	}
+	s.BranchAlloc += other.BranchAlloc
+	s.BranchInuse += other.BranchInuse
+	s.LeafAlloc += other.LeafAlloc
+	s.LeafInuse += other.LeafInuse
+
+	s.BucketN += other.BucketN
+	s.InlineBucketN += other.InlineBucketN
+	s.InlineBucketInuse += other.InlineBucketInuse
+}
+
+// cloneBytes returns a copy of a given slice.
+func cloneBytes(v []byte) []byte {
+	var clone = make([]byte, len(v))
+	copy(clone, v)
+	return clone
+}
+
+type BucketStructure struct {
+	Name     string            `json:"name"`              // name of the bucket
+	KeyN     int               `json:"keyN"`              // number of key/value pairs
+	Children []BucketStructure `json:"buckets,omitempty"` // child buckets
+}
diff --git a/vendor/go.etcd.io/bbolt/compact.go b/vendor/go.etcd.io/bbolt/compact.go
new file mode 100644
index 0000000..5f1d4c3
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/compact.go
@@ -0,0 +1,119 @@
+package bbolt
+
+// Compact will create a copy of the source DB and in the destination DB. This may
+// reclaim space that the source database no longer has use for. txMaxSize can be
+// used to limit the transactions size of this process and may trigger intermittent
+// commits. A value of zero will ignore transaction sizes.
+// TODO: merge with: https://github.com/etcd-io/etcd/blob/b7f0f52a16dbf83f18ca1d803f7892d750366a94/mvcc/backend/backend.go#L349
+func Compact(dst, src *DB, txMaxSize int64) error {
+	// commit regularly, or we'll run out of memory for large datasets if using one transaction.
+	var size int64
+	tx, err := dst.Begin(true)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if tempErr := tx.Rollback(); tempErr != nil {
+			err = tempErr
+		}
+	}()
+
+	if err := walk(src, func(keys [][]byte, k, v []byte, seq uint64) error {
+		// On each key/value, check if we have exceeded tx size.
+		sz := int64(len(k) + len(v))
+		if size+sz > txMaxSize && txMaxSize != 0 {
+			// Commit previous transaction.
+			if err := tx.Commit(); err != nil {
+				return err
+			}
+
+			// Start new transaction.
+			tx, err = dst.Begin(true)
+			if err != nil {
+				return err
+			}
+			size = 0
+		}
+		size += sz
+
+		// Create bucket on the root transaction if this is the first level.
+		nk := len(keys)
+		if nk == 0 {
+			bkt, err := tx.CreateBucket(k)
+			if err != nil {
+				return err
+			}
+			if err := bkt.SetSequence(seq); err != nil {
+				return err
+			}
+			return nil
+		}
+
+		// Create buckets on subsequent levels, if necessary.
+		b := tx.Bucket(keys[0])
+		if nk > 1 {
+			for _, k := range keys[1:] {
+				b = b.Bucket(k)
+			}
+		}
+
+		// Fill the entire page for best compaction.
+		b.FillPercent = 1.0
+
+		// If there is no value then this is a bucket call.
+		if v == nil {
+			bkt, err := b.CreateBucket(k)
+			if err != nil {
+				return err
+			}
+			if err := bkt.SetSequence(seq); err != nil {
+				return err
+			}
+			return nil
+		}
+
+		// Otherwise treat it as a key/value pair.
+		return b.Put(k, v)
+	}); err != nil {
+		return err
+	}
+	err = tx.Commit()
+
+	return err
+}
+
+// walkFunc is the type of the function called for keys (buckets and "normal"
+// values) discovered by Walk. keys is the list of keys to descend to the bucket
+// owning the discovered key/value pair k/v.
+type walkFunc func(keys [][]byte, k, v []byte, seq uint64) error
+
+// walk walks recursively the bolt database db, calling walkFn for each key it finds.
+func walk(db *DB, walkFn walkFunc) error {
+	return db.View(func(tx *Tx) error {
+		return tx.ForEach(func(name []byte, b *Bucket) error {
+			return walkBucket(b, nil, name, nil, b.Sequence(), walkFn)
+		})
+	})
+}
+
+func walkBucket(b *Bucket, keypath [][]byte, k, v []byte, seq uint64, fn walkFunc) error {
+	// Execute callback.
+	if err := fn(keypath, k, v, seq); err != nil {
+		return err
+	}
+
+	// If this is not a bucket then stop.
+	if v != nil {
+		return nil
+	}
+
+	// Iterate over each child key/value.
+	keypath = append(keypath, k)
+	return b.ForEach(func(k, v []byte) error {
+		if v == nil {
+			bkt := b.Bucket(k)
+			return walkBucket(bkt, keypath, k, nil, bkt.Sequence(), fn)
+		}
+		return walkBucket(b, keypath, k, v, b.Sequence(), fn)
+	})
+}
diff --git a/vendor/go.etcd.io/bbolt/cursor.go b/vendor/go.etcd.io/bbolt/cursor.go
new file mode 100644
index 0000000..0c1e28c
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/cursor.go
@@ -0,0 +1,432 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+
+	"go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// Cursor represents an iterator that can traverse over all key/value pairs in a bucket
+// in lexicographical order.
+// Cursors see nested buckets with value == nil.
+// Cursors can be obtained from a transaction and are valid as long as the transaction is open.
+//
+// Keys and values returned from the cursor are only valid for the life of the transaction.
+//
+// Changing data while traversing with a cursor may cause it to be invalidated
+// and return unexpected keys and/or values. You must reposition your cursor
+// after mutating data.
+type Cursor struct {
+	bucket *Bucket
+	stack  []elemRef
+}
+
+// Bucket returns the bucket that this cursor was created from.
+func (c *Cursor) Bucket() *Bucket {
+	return c.bucket
+}
+
+// First moves the cursor to the first item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) First() (key []byte, value []byte) {
+	common.Assert(c.bucket.tx.db != nil, "tx closed")
+	k, v, flags := c.first()
+	if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+func (c *Cursor) first() (key []byte, value []byte, flags uint32) {
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.RootPage())
+	c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	c.goToFirstElementOnTheStack()
+
+	// If we land on an empty page then move to the next value.
+	// https://github.com/boltdb/bolt/issues/450
+	if c.stack[len(c.stack)-1].count() == 0 {
+		c.next()
+	}
+
+	k, v, flags := c.keyValue()
+	if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil, flags
+	}
+	return k, v, flags
+}
+
+// Last moves the cursor to the last item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Last() (key []byte, value []byte) {
+	common.Assert(c.bucket.tx.db != nil, "tx closed")
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.RootPage())
+	ref := elemRef{page: p, node: n}
+	ref.index = ref.count() - 1
+	c.stack = append(c.stack, ref)
+	c.last()
+
+	// If this is an empty page (calling Delete may result in empty pages)
+	// we call prev to find the last page that is not empty
+	for len(c.stack) > 1 && c.stack[len(c.stack)-1].count() == 0 {
+		c.prev()
+	}
+
+	if len(c.stack) == 0 {
+		return nil, nil
+	}
+
+	k, v, flags := c.keyValue()
+	if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Next moves the cursor to the next item in the bucket and returns its key and value.
+// If the cursor is at the end of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Next() (key []byte, value []byte) {
+	common.Assert(c.bucket.tx.db != nil, "tx closed")
+	k, v, flags := c.next()
+	if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Prev moves the cursor to the previous item in the bucket and returns its key and value.
+// If the cursor is at the beginning of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Prev() (key []byte, value []byte) {
+	common.Assert(c.bucket.tx.db != nil, "tx closed")
+	k, v, flags := c.prev()
+	if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Seek moves the cursor to a given key using a b-tree search and returns it.
+// If the key does not exist then the next key is used. If no keys
+// follow, a nil key is returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
+	common.Assert(c.bucket.tx.db != nil, "tx closed")
+
+	k, v, flags := c.seek(seek)
+
+	// If we ended up after the last element of a page then move to the next one.
+	if ref := &c.stack[len(c.stack)-1]; ref.index >= ref.count() {
+		k, v, flags = c.next()
+	}
+
+	if k == nil {
+		return nil, nil
+	} else if (flags & uint32(common.BucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Delete removes the current key/value under the cursor from the bucket.
+// Delete fails if current key/value is a bucket or if the transaction is not writable.
+func (c *Cursor) Delete() error {
+	if c.bucket.tx.db == nil {
+		return errors.ErrTxClosed
+	} else if !c.bucket.Writable() {
+		return errors.ErrTxNotWritable
+	}
+
+	key, _, flags := c.keyValue()
+	// Return an error if current value is a bucket.
+	if (flags & common.BucketLeafFlag) != 0 {
+		return errors.ErrIncompatibleValue
+	}
+	c.node().del(key)
+
+	return nil
+}
+
+// seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used.
+func (c *Cursor) seek(seek []byte) (key []byte, value []byte, flags uint32) {
+	// Start from root page/node and traverse to correct page.
+	c.stack = c.stack[:0]
+	c.search(seek, c.bucket.RootPage())
+
+	// If this is a bucket then return a nil value.
+	return c.keyValue()
+}
+
+// first moves the cursor to the first leaf element under the last page in the stack.
+func (c *Cursor) goToFirstElementOnTheStack() {
+	for {
+		// Exit when we hit a leaf page.
+		var ref = &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the first element to the stack.
+		var pgId common.Pgid
+		if ref.node != nil {
+			pgId = ref.node.inodes[ref.index].Pgid()
+		} else {
+			pgId = ref.page.BranchPageElement(uint16(ref.index)).Pgid()
+		}
+		p, n := c.bucket.pageNode(pgId)
+		c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	}
+}
+
+// last moves the cursor to the last leaf element under the last page in the stack.
+func (c *Cursor) last() {
+	for {
+		// Exit when we hit a leaf page.
+		ref := &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the last element in the stack.
+		var pgId common.Pgid
+		if ref.node != nil {
+			pgId = ref.node.inodes[ref.index].Pgid()
+		} else {
+			pgId = ref.page.BranchPageElement(uint16(ref.index)).Pgid()
+		}
+		p, n := c.bucket.pageNode(pgId)
+
+		var nextRef = elemRef{page: p, node: n}
+		nextRef.index = nextRef.count() - 1
+		c.stack = append(c.stack, nextRef)
+	}
+}
+
+// next moves to the next leaf element and returns the key and value.
+// If the cursor is at the last leaf element then it stays there and returns nil.
+func (c *Cursor) next() (key []byte, value []byte, flags uint32) {
+	for {
+		// Attempt to move over one element until we're successful.
+		// Move up the stack as we hit the end of each page in our stack.
+		var i int
+		for i = len(c.stack) - 1; i >= 0; i-- {
+			elem := &c.stack[i]
+			if elem.index < elem.count()-1 {
+				elem.index++
+				break
+			}
+		}
+
+		// If we've hit the root page then stop and return. This will leave the
+		// cursor on the last element of the last page.
+		if i == -1 {
+			return nil, nil, 0
+		}
+
+		// Otherwise start from where we left off in the stack and find the
+		// first element of the first leaf page.
+		c.stack = c.stack[:i+1]
+		c.goToFirstElementOnTheStack()
+
+		// If this is an empty page then restart and move back up the stack.
+		// https://github.com/boltdb/bolt/issues/450
+		if c.stack[len(c.stack)-1].count() == 0 {
+			continue
+		}
+
+		return c.keyValue()
+	}
+}
+
+// prev moves the cursor to the previous item in the bucket and returns its key and value.
+// If the cursor is at the beginning of the bucket then a nil key and value are returned.
+func (c *Cursor) prev() (key []byte, value []byte, flags uint32) {
+	// Attempt to move back one element until we're successful.
+	// Move up the stack as we hit the beginning of each page in our stack.
+	for i := len(c.stack) - 1; i >= 0; i-- {
+		elem := &c.stack[i]
+		if elem.index > 0 {
+			elem.index--
+			break
+		}
+		// If we've hit the beginning, we should stop moving the cursor,
+		// and stay at the first element, so that users can continue to
+		// iterate over the elements in reverse direction by calling `Next`.
+		// We should return nil in such case.
+		// Refer to https://github.com/etcd-io/bbolt/issues/733
+		if len(c.stack) == 1 {
+			c.first()
+			return nil, nil, 0
+		}
+		c.stack = c.stack[:i]
+	}
+
+	// If we've hit the end then return nil.
+	if len(c.stack) == 0 {
+		return nil, nil, 0
+	}
+
+	// Move down the stack to find the last element of the last leaf under this branch.
+	c.last()
+	return c.keyValue()
+}
+
+// search recursively performs a binary search against a given page/node until it finds a given key.
+func (c *Cursor) search(key []byte, pgId common.Pgid) {
+	p, n := c.bucket.pageNode(pgId)
+	if p != nil && !p.IsBranchPage() && !p.IsLeafPage() {
+		panic(fmt.Sprintf("invalid page type: %d: %x", p.Id(), p.Flags()))
+	}
+	e := elemRef{page: p, node: n}
+	c.stack = append(c.stack, e)
+
+	// If we're on a leaf page/node then find the specific node.
+	if e.isLeaf() {
+		c.nsearch(key)
+		return
+	}
+
+	if n != nil {
+		c.searchNode(key, n)
+		return
+	}
+	c.searchPage(key, p)
+}
+
+func (c *Cursor) searchNode(key []byte, n *node) {
+	var exact bool
+	index := sort.Search(len(n.inodes), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(n.inodes[i].Key(), key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, n.inodes[index].Pgid())
+}
+
+func (c *Cursor) searchPage(key []byte, p *common.Page) {
+	// Binary search for the correct range.
+	inodes := p.BranchPageElements()
+
+	var exact bool
+	index := sort.Search(int(p.Count()), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(inodes[i].Key(), key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, inodes[index].Pgid())
+}
+
+// nsearch searches the leaf node on the top of the stack for a key.
+func (c *Cursor) nsearch(key []byte) {
+	e := &c.stack[len(c.stack)-1]
+	p, n := e.page, e.node
+
+	// If we have a node then search its inodes.
+	if n != nil {
+		index := sort.Search(len(n.inodes), func(i int) bool {
+			return bytes.Compare(n.inodes[i].Key(), key) != -1
+		})
+		e.index = index
+		return
+	}
+
+	// If we have a page then search its leaf elements.
+	inodes := p.LeafPageElements()
+	index := sort.Search(int(p.Count()), func(i int) bool {
+		return bytes.Compare(inodes[i].Key(), key) != -1
+	})
+	e.index = index
+}
+
+// keyValue returns the key and value of the current leaf element.
+func (c *Cursor) keyValue() ([]byte, []byte, uint32) {
+	ref := &c.stack[len(c.stack)-1]
+
+	// If the cursor is pointing to the end of page/node then return nil.
+	if ref.count() == 0 || ref.index >= ref.count() {
+		return nil, nil, 0
+	}
+
+	// Retrieve value from node.
+	if ref.node != nil {
+		inode := &ref.node.inodes[ref.index]
+		return inode.Key(), inode.Value(), inode.Flags()
+	}
+
+	// Or retrieve value from page.
+	elem := ref.page.LeafPageElement(uint16(ref.index))
+	return elem.Key(), elem.Value(), elem.Flags()
+}
+
+// node returns the node that the cursor is currently positioned on.
+func (c *Cursor) node() *node {
+	common.Assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack")
+
+	// If the top of the stack is a leaf node then just return it.
+	if ref := &c.stack[len(c.stack)-1]; ref.node != nil && ref.isLeaf() {
+		return ref.node
+	}
+
+	// Start from root and traverse down the hierarchy.
+	var n = c.stack[0].node
+	if n == nil {
+		n = c.bucket.node(c.stack[0].page.Id(), nil)
+	}
+	for _, ref := range c.stack[:len(c.stack)-1] {
+		common.Assert(!n.isLeaf, "expected branch node")
+		n = n.childAt(ref.index)
+	}
+	common.Assert(n.isLeaf, "expected leaf node")
+	return n
+}
+
+// elemRef represents a reference to an element on a given page/node.
+type elemRef struct {
+	page  *common.Page
+	node  *node
+	index int
+}
+
+// isLeaf returns whether the ref is pointing at a leaf page/node.
+func (r *elemRef) isLeaf() bool {
+	if r.node != nil {
+		return r.node.isLeaf
+	}
+	return r.page.IsLeafPage()
+}
+
+// count returns the number of inodes or page elements.
+func (r *elemRef) count() int {
+	if r.node != nil {
+		return len(r.node.inodes)
+	}
+	return int(r.page.Count())
+}
diff --git a/vendor/go.etcd.io/bbolt/db.go b/vendor/go.etcd.io/bbolt/db.go
new file mode 100644
index 0000000..622947d
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/db.go
@@ -0,0 +1,1398 @@
+package bbolt
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"sync"
+	"time"
+	"unsafe"
+
+	berrors "go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+	fl "go.etcd.io/bbolt/internal/freelist"
+)
+
+// The time elapsed between consecutive file locking attempts.
+const flockRetryTimeout = 50 * time.Millisecond
+
+// FreelistType is the type of the freelist backend
+type FreelistType string
+
+// TODO(ahrtr): eventually we should (step by step)
+//  1. default to `FreelistMapType`;
+//  2. remove the `FreelistArrayType`, do not export `FreelistMapType`
+//     and remove field `FreelistType' from both `DB` and `Options`;
+const (
+	// FreelistArrayType indicates backend freelist type is array
+	FreelistArrayType = FreelistType("array")
+	// FreelistMapType indicates backend freelist type is hashmap
+	FreelistMapType = FreelistType("hashmap")
+)
+
+// DB represents a collection of buckets persisted to a file on disk.
+// All data access is performed through transactions which can be obtained through the DB.
+// All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called.
+type DB struct {
+	// Put `stats` at the first field to ensure it's 64-bit aligned. Note that
+	// the first word in an allocated struct can be relied upon to be 64-bit
+	// aligned. Refer to https://pkg.go.dev/sync/atomic#pkg-note-BUG. Also
+	// refer to discussion in https://github.com/etcd-io/bbolt/issues/577.
+	stats Stats
+
+	// When enabled, the database will perform a Check() after every commit.
+	// A panic is issued if the database is in an inconsistent state. This
+	// flag has a large performance impact so it should only be used for
+	// debugging purposes.
+	StrictMode bool
+
+	// Setting the NoSync flag will cause the database to skip fsync()
+	// calls after each commit. This can be useful when bulk loading data
+	// into a database and you can restart the bulk load in the event of
+	// a system failure or database corruption. Do not set this flag for
+	// normal use.
+	//
+	// If the package global IgnoreNoSync constant is true, this value is
+	// ignored.  See the comment on that constant for more details.
+	//
+	// THIS IS UNSAFE. PLEASE USE WITH CAUTION.
+	NoSync bool
+
+	// When true, skips syncing freelist to disk. This improves the database
+	// write performance under normal operation, but requires a full database
+	// re-sync during recovery.
+	NoFreelistSync bool
+
+	// FreelistType sets the backend freelist type. There are two options. Array which is simple but endures
+	// dramatic performance degradation if database is large and fragmentation in freelist is common.
+	// The alternative one is using hashmap, it is faster in almost all circumstances
+	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
+	// The default type is array
+	FreelistType FreelistType
+
+	// When true, skips the truncate call when growing the database.
+	// Setting this to true is only safe on non-ext3/ext4 systems.
+	// Skipping truncation avoids preallocation of hard drive space and
+	// bypasses a truncate() and fsync() syscall on remapping.
+	//
+	// https://github.com/boltdb/bolt/issues/284
+	NoGrowSync bool
+
+	// When `true`, bbolt will always load the free pages when opening the DB.
+	// When opening db in write mode, this flag will always automatically
+	// set to `true`.
+	PreLoadFreelist bool
+
+	// If you want to read the entire database fast, you can set MmapFlag to
+	// syscall.MAP_POPULATE on Linux 2.6.23+ for sequential read-ahead.
+	MmapFlags int
+
+	// MaxBatchSize is the maximum size of a batch. Default value is
+	// copied from DefaultMaxBatchSize in Open.
+	//
+	// If <=0, disables batching.
+	//
+	// Do not change concurrently with calls to Batch.
+	MaxBatchSize int
+
+	// MaxBatchDelay is the maximum delay before a batch starts.
+	// Default value is copied from DefaultMaxBatchDelay in Open.
+	//
+	// If <=0, effectively disables batching.
+	//
+	// Do not change concurrently with calls to Batch.
+	MaxBatchDelay time.Duration
+
+	// AllocSize is the amount of space allocated when the database
+	// needs to create new pages. This is done to amortize the cost
+	// of truncate() and fsync() when growing the data file.
+	AllocSize int
+
+	// Mlock locks database file in memory when set to true.
+	// It prevents major page faults, however used memory can't be reclaimed.
+	//
+	// Supported only on Unix via mlock/munlock syscalls.
+	Mlock bool
+
+	logger Logger
+
+	path     string
+	openFile func(string, int, os.FileMode) (*os.File, error)
+	file     *os.File
+	// `dataref` isn't used at all on Windows, and the golangci-lint
+	// always fails on Windows platform.
+	//nolint
+	dataref  []byte // mmap'ed readonly, write throws SEGV
+	data     *[common.MaxMapSize]byte
+	datasz   int
+	meta0    *common.Meta
+	meta1    *common.Meta
+	pageSize int
+	opened   bool
+	rwtx     *Tx
+	txs      []*Tx
+
+	freelist     fl.Interface
+	freelistLoad sync.Once
+
+	pagePool sync.Pool
+
+	batchMu sync.Mutex
+	batch   *batch
+
+	rwlock   sync.Mutex   // Allows only one writer at a time.
+	metalock sync.Mutex   // Protects meta page access.
+	mmaplock sync.RWMutex // Protects mmap access during remapping.
+	statlock sync.RWMutex // Protects stats access.
+
+	ops struct {
+		writeAt func(b []byte, off int64) (n int, err error)
+	}
+
+	// Read only mode.
+	// When true, Update() and Begin(true) return ErrDatabaseReadOnly immediately.
+	readOnly bool
+}
+
+// Path returns the path to currently open database file.
+func (db *DB) Path() string {
+	return db.path
+}
+
+// GoString returns the Go string representation of the database.
+func (db *DB) GoString() string {
+	return fmt.Sprintf("bolt.DB{path:%q}", db.path)
+}
+
+// String returns the string representation of the database.
+func (db *DB) String() string {
+	return fmt.Sprintf("DB<%q>", db.path)
+}
+
+// Open creates and opens a database at the given path with a given file mode.
+// If the file does not exist then it will be created automatically with a given file mode.
+// Passing in nil options will cause Bolt to open the database with the default options.
+// Note: For read/write transactions, ensure the owner has write permission on the created/opened database file, e.g. 0600
+func Open(path string, mode os.FileMode, options *Options) (db *DB, err error) {
+	db = &DB{
+		opened: true,
+	}
+
+	// Set default options if no options are provided.
+	if options == nil {
+		options = DefaultOptions
+	}
+	db.NoSync = options.NoSync
+	db.NoGrowSync = options.NoGrowSync
+	db.MmapFlags = options.MmapFlags
+	db.NoFreelistSync = options.NoFreelistSync
+	db.PreLoadFreelist = options.PreLoadFreelist
+	db.FreelistType = options.FreelistType
+	db.Mlock = options.Mlock
+
+	// Set default values for later DB operations.
+	db.MaxBatchSize = common.DefaultMaxBatchSize
+	db.MaxBatchDelay = common.DefaultMaxBatchDelay
+	db.AllocSize = common.DefaultAllocSize
+
+	if options.Logger == nil {
+		db.logger = getDiscardLogger()
+	} else {
+		db.logger = options.Logger
+	}
+
+	lg := db.Logger()
+	if lg != discardLogger {
+		lg.Infof("Opening db file (%s) with mode %s and with options: %s", path, mode, options)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Opening bbolt db (%s) failed: %v", path, err)
+			} else {
+				lg.Infof("Opening bbolt db (%s) successfully", path)
+			}
+		}()
+	}
+
+	flag := os.O_RDWR
+	if options.ReadOnly {
+		flag = os.O_RDONLY
+		db.readOnly = true
+	} else {
+		// always load free pages in write mode
+		db.PreLoadFreelist = true
+		flag |= os.O_CREATE
+	}
+
+	db.openFile = options.OpenFile
+	if db.openFile == nil {
+		db.openFile = os.OpenFile
+	}
+
+	// Open data file and separate sync handler for metadata writes.
+	if db.file, err = db.openFile(path, flag, mode); err != nil {
+		_ = db.close()
+		lg.Errorf("failed to open db file (%s): %v", path, err)
+		return nil, err
+	}
+	db.path = db.file.Name()
+
+	// Lock file so that other processes using Bolt in read-write mode cannot
+	// use the database  at the same time. This would cause corruption since
+	// the two processes would write meta pages and free pages separately.
+	// The database file is locked exclusively (only one process can grab the lock)
+	// if !options.ReadOnly.
+	// The database file is locked using the shared lock (more than one process may
+	// hold a lock at the same time) otherwise (options.ReadOnly is set).
+	if err = flock(db, !db.readOnly, options.Timeout); err != nil {
+		_ = db.close()
+		lg.Errorf("failed to lock db file (%s), readonly: %t, error: %v", path, db.readOnly, err)
+		return nil, err
+	}
+
+	// Default values for test hooks
+	db.ops.writeAt = db.file.WriteAt
+
+	if db.pageSize = options.PageSize; db.pageSize == 0 {
+		// Set the default page size to the OS page size.
+		db.pageSize = common.DefaultPageSize
+	}
+
+	// Initialize the database if it doesn't exist.
+	if info, statErr := db.file.Stat(); statErr != nil {
+		_ = db.close()
+		lg.Errorf("failed to get db file's stats (%s): %v", path, err)
+		return nil, statErr
+	} else if info.Size() == 0 {
+		// Initialize new files with meta pages.
+		if err = db.init(); err != nil {
+			// clean up file descriptor on initialization fail
+			_ = db.close()
+			lg.Errorf("failed to initialize db file (%s): %v", path, err)
+			return nil, err
+		}
+	} else {
+		// try to get the page size from the metadata pages
+		if db.pageSize, err = db.getPageSize(); err != nil {
+			_ = db.close()
+			lg.Errorf("failed to get page size from db file (%s): %v", path, err)
+			return nil, err
+		}
+	}
+
+	// Initialize page pool.
+	db.pagePool = sync.Pool{
+		New: func() interface{} {
+			return make([]byte, db.pageSize)
+		},
+	}
+
+	// Memory map the data file.
+	if err = db.mmap(options.InitialMmapSize); err != nil {
+		_ = db.close()
+		lg.Errorf("failed to map db file (%s): %v", path, err)
+		return nil, err
+	}
+
+	if db.PreLoadFreelist {
+		db.loadFreelist()
+	}
+
+	if db.readOnly {
+		return db, nil
+	}
+
+	// Flush freelist when transitioning from no sync to sync so
+	// NoFreelistSync unaware boltdb can open the db later.
+	if !db.NoFreelistSync && !db.hasSyncedFreelist() {
+		tx, txErr := db.Begin(true)
+		if tx != nil {
+			txErr = tx.Commit()
+		}
+		if txErr != nil {
+			lg.Errorf("starting readwrite transaction failed: %v", txErr)
+			_ = db.close()
+			return nil, txErr
+		}
+	}
+
+	// Mark the database as opened and return.
+	return db, nil
+}
+
+// getPageSize reads the pageSize from the meta pages. It tries
+// to read the first meta page firstly. If the first page is invalid,
+// then it tries to read the second page using the default page size.
+func (db *DB) getPageSize() (int, error) {
+	var (
+		meta0CanRead, meta1CanRead bool
+	)
+
+	// Read the first meta page to determine the page size.
+	if pgSize, canRead, err := db.getPageSizeFromFirstMeta(); err != nil {
+		// We cannot read the page size from page 0, but can read page 0.
+		meta0CanRead = canRead
+	} else {
+		return pgSize, nil
+	}
+
+	// Read the second meta page to determine the page size.
+	if pgSize, canRead, err := db.getPageSizeFromSecondMeta(); err != nil {
+		// We cannot read the page size from page 1, but can read page 1.
+		meta1CanRead = canRead
+	} else {
+		return pgSize, nil
+	}
+
+	// If we can't read the page size from both pages, but can read
+	// either page, then we assume it's the same as the OS or the one
+	// given, since that's how the page size was chosen in the first place.
+	//
+	// If both pages are invalid, and (this OS uses a different page size
+	// from what the database was created with or the given page size is
+	// different from what the database was created with), then we are out
+	// of luck and cannot access the database.
+	if meta0CanRead || meta1CanRead {
+		return db.pageSize, nil
+	}
+
+	return 0, berrors.ErrInvalid
+}
+
+// getPageSizeFromFirstMeta reads the pageSize from the first meta page
+func (db *DB) getPageSizeFromFirstMeta() (int, bool, error) {
+	var buf [0x1000]byte
+	var metaCanRead bool
+	if bw, err := db.file.ReadAt(buf[:], 0); err == nil && bw == len(buf) {
+		metaCanRead = true
+		if m := db.pageInBuffer(buf[:], 0).Meta(); m.Validate() == nil {
+			return int(m.PageSize()), metaCanRead, nil
+		}
+	}
+	return 0, metaCanRead, berrors.ErrInvalid
+}
+
+// getPageSizeFromSecondMeta reads the pageSize from the second meta page
+func (db *DB) getPageSizeFromSecondMeta() (int, bool, error) {
+	var (
+		fileSize    int64
+		metaCanRead bool
+	)
+
+	// get the db file size
+	if info, err := db.file.Stat(); err != nil {
+		return 0, metaCanRead, err
+	} else {
+		fileSize = info.Size()
+	}
+
+	// We need to read the second meta page, so we should skip the first page;
+	// but we don't know the exact page size yet, it's chicken & egg problem.
+	// The solution is to try all the possible page sizes, which starts from 1KB
+	// and until 16MB (1024<<14) or the end of the db file
+	//
+	// TODO: should we support larger page size?
+	for i := 0; i <= 14; i++ {
+		var buf [0x1000]byte
+		var pos int64 = 1024 << uint(i)
+		if pos >= fileSize-1024 {
+			break
+		}
+		bw, err := db.file.ReadAt(buf[:], pos)
+		if (err == nil && bw == len(buf)) || (err == io.EOF && int64(bw) == (fileSize-pos)) {
+			metaCanRead = true
+			if m := db.pageInBuffer(buf[:], 0).Meta(); m.Validate() == nil {
+				return int(m.PageSize()), metaCanRead, nil
+			}
+		}
+	}
+
+	return 0, metaCanRead, berrors.ErrInvalid
+}
+
+// loadFreelist reads the freelist if it is synced, or reconstructs it
+// by scanning the DB if it is not synced. It assumes there are no
+// concurrent accesses being made to the freelist.
+func (db *DB) loadFreelist() {
+	db.freelistLoad.Do(func() {
+		db.freelist = newFreelist(db.FreelistType)
+		if !db.hasSyncedFreelist() {
+			// Reconstruct free list by scanning the DB.
+			db.freelist.Init(db.freepages())
+		} else {
+			// Read free list from freelist page.
+			db.freelist.Read(db.page(db.meta().Freelist()))
+		}
+		db.stats.FreePageN = db.freelist.FreeCount()
+	})
+}
+
+func (db *DB) hasSyncedFreelist() bool {
+	return db.meta().Freelist() != common.PgidNoFreelist
+}
+
+func (db *DB) fileSize() (int, error) {
+	info, err := db.file.Stat()
+	if err != nil {
+		return 0, fmt.Errorf("file stat error: %w", err)
+	}
+	sz := int(info.Size())
+	if sz < db.pageSize*2 {
+		return 0, fmt.Errorf("file size too small %d", sz)
+	}
+	return sz, nil
+}
+
+// mmap opens the underlying memory-mapped file and initializes the meta references.
+// minsz is the minimum size that the new mmap can be.
+func (db *DB) mmap(minsz int) (err error) {
+	db.mmaplock.Lock()
+	defer db.mmaplock.Unlock()
+
+	lg := db.Logger()
+
+	// Ensure the size is at least the minimum size.
+	var fileSize int
+	fileSize, err = db.fileSize()
+	if err != nil {
+		lg.Errorf("getting file size failed: %w", err)
+		return err
+	}
+	var size = fileSize
+	if size < minsz {
+		size = minsz
+	}
+	size, err = db.mmapSize(size)
+	if err != nil {
+		lg.Errorf("getting map size failed: %w", err)
+		return err
+	}
+
+	if db.Mlock {
+		// Unlock db memory
+		if err := db.munlock(fileSize); err != nil {
+			return err
+		}
+	}
+
+	// Dereference all mmap references before unmapping.
+	if db.rwtx != nil {
+		db.rwtx.root.dereference()
+	}
+
+	// Unmap existing data before continuing.
+	if err = db.munmap(); err != nil {
+		return err
+	}
+
+	// Memory-map the data file as a byte slice.
+	// gofail: var mapError string
+	// return errors.New(mapError)
+	if err = mmap(db, size); err != nil {
+		lg.Errorf("[GOOS: %s, GOARCH: %s] mmap failed, size: %d, error: %v", runtime.GOOS, runtime.GOARCH, size, err)
+		return err
+	}
+
+	// Perform unmmap on any error to reset all data fields:
+	// dataref, data, datasz, meta0 and meta1.
+	defer func() {
+		if err != nil {
+			if unmapErr := db.munmap(); unmapErr != nil {
+				err = fmt.Errorf("%w; rollback unmap also failed: %v", err, unmapErr)
+			}
+		}
+	}()
+
+	if db.Mlock {
+		// Don't allow swapping of data file
+		if err := db.mlock(fileSize); err != nil {
+			return err
+		}
+	}
+
+	// Save references to the meta pages.
+	db.meta0 = db.page(0).Meta()
+	db.meta1 = db.page(1).Meta()
+
+	// Validate the meta pages. We only return an error if both meta pages fail
+	// validation, since meta0 failing validation means that it wasn't saved
+	// properly -- but we can recover using meta1. And vice-versa.
+	err0 := db.meta0.Validate()
+	err1 := db.meta1.Validate()
+	if err0 != nil && err1 != nil {
+		lg.Errorf("both meta pages are invalid, meta0: %v, meta1: %v", err0, err1)
+		return err0
+	}
+
+	return nil
+}
+
+func (db *DB) invalidate() {
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+
+	db.meta0 = nil
+	db.meta1 = nil
+}
+
+// munmap unmaps the data file from memory.
+func (db *DB) munmap() error {
+	defer db.invalidate()
+
+	// gofail: var unmapError string
+	// return errors.New(unmapError)
+	if err := munmap(db); err != nil {
+		db.Logger().Errorf("[GOOS: %s, GOARCH: %s] munmap failed, db.datasz: %d, error: %v", runtime.GOOS, runtime.GOARCH, db.datasz, err)
+		return fmt.Errorf("unmap error: %v", err.Error())
+	}
+
+	return nil
+}
+
+// mmapSize determines the appropriate size for the mmap given the current size
+// of the database. The minimum size is 32KB and doubles until it reaches 1GB.
+// Returns an error if the new mmap size is greater than the max allowed.
+func (db *DB) mmapSize(size int) (int, error) {
+	// Double the size from 32KB until 1GB.
+	for i := uint(15); i <= 30; i++ {
+		if size <= 1<<i {
+			return 1 << i, nil
+		}
+	}
+
+	// Verify the requested size is not above the maximum allowed.
+	if size > common.MaxMapSize {
+		return 0, errors.New("mmap too large")
+	}
+
+	// If larger than 1GB then grow by 1GB at a time.
+	sz := int64(size)
+	if remainder := sz % int64(common.MaxMmapStep); remainder > 0 {
+		sz += int64(common.MaxMmapStep) - remainder
+	}
+
+	// Ensure that the mmap size is a multiple of the page size.
+	// This should always be true since we're incrementing in MBs.
+	pageSize := int64(db.pageSize)
+	if (sz % pageSize) != 0 {
+		sz = ((sz / pageSize) + 1) * pageSize
+	}
+
+	// If we've exceeded the max size then only grow up to the max size.
+	if sz > common.MaxMapSize {
+		sz = common.MaxMapSize
+	}
+
+	return int(sz), nil
+}
+
+func (db *DB) munlock(fileSize int) error {
+	// gofail: var munlockError string
+	// return errors.New(munlockError)
+	if err := munlock(db, fileSize); err != nil {
+		db.Logger().Errorf("[GOOS: %s, GOARCH: %s] munlock failed, fileSize: %d, db.datasz: %d, error: %v", runtime.GOOS, runtime.GOARCH, fileSize, db.datasz, err)
+		return fmt.Errorf("munlock error: %v", err.Error())
+	}
+	return nil
+}
+
+func (db *DB) mlock(fileSize int) error {
+	// gofail: var mlockError string
+	// return errors.New(mlockError)
+	if err := mlock(db, fileSize); err != nil {
+		db.Logger().Errorf("[GOOS: %s, GOARCH: %s] mlock failed, fileSize: %d, db.datasz: %d, error: %v", runtime.GOOS, runtime.GOARCH, fileSize, db.datasz, err)
+		return fmt.Errorf("mlock error: %v", err.Error())
+	}
+	return nil
+}
+
+func (db *DB) mrelock(fileSizeFrom, fileSizeTo int) error {
+	if err := db.munlock(fileSizeFrom); err != nil {
+		return err
+	}
+	if err := db.mlock(fileSizeTo); err != nil {
+		return err
+	}
+	return nil
+}
+
+// init creates a new database file and initializes its meta pages.
+func (db *DB) init() error {
+	// Create two meta pages on a buffer.
+	buf := make([]byte, db.pageSize*4)
+	for i := 0; i < 2; i++ {
+		p := db.pageInBuffer(buf, common.Pgid(i))
+		p.SetId(common.Pgid(i))
+		p.SetFlags(common.MetaPageFlag)
+
+		// Initialize the meta page.
+		m := p.Meta()
+		m.SetMagic(common.Magic)
+		m.SetVersion(common.Version)
+		m.SetPageSize(uint32(db.pageSize))
+		m.SetFreelist(2)
+		m.SetRootBucket(common.NewInBucket(3, 0))
+		m.SetPgid(4)
+		m.SetTxid(common.Txid(i))
+		m.SetChecksum(m.Sum64())
+	}
+
+	// Write an empty freelist at page 3.
+	p := db.pageInBuffer(buf, common.Pgid(2))
+	p.SetId(2)
+	p.SetFlags(common.FreelistPageFlag)
+	p.SetCount(0)
+
+	// Write an empty leaf page at page 4.
+	p = db.pageInBuffer(buf, common.Pgid(3))
+	p.SetId(3)
+	p.SetFlags(common.LeafPageFlag)
+	p.SetCount(0)
+
+	// Write the buffer to our data file.
+	if _, err := db.ops.writeAt(buf, 0); err != nil {
+		db.Logger().Errorf("writeAt failed: %w", err)
+		return err
+	}
+	if err := fdatasync(db); err != nil {
+		db.Logger().Errorf("[GOOS: %s, GOARCH: %s] fdatasync failed: %w", runtime.GOOS, runtime.GOARCH, err)
+		return err
+	}
+
+	return nil
+}
+
+// Close releases all database resources.
+// It will block waiting for any open transactions to finish
+// before closing the database and returning.
+func (db *DB) Close() error {
+	db.rwlock.Lock()
+	defer db.rwlock.Unlock()
+
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
+	db.mmaplock.Lock()
+	defer db.mmaplock.Unlock()
+
+	return db.close()
+}
+
+func (db *DB) close() error {
+	if !db.opened {
+		return nil
+	}
+
+	db.opened = false
+
+	db.freelist = nil
+
+	// Clear ops.
+	db.ops.writeAt = nil
+
+	var errs []error
+	// Close the mmap.
+	if err := db.munmap(); err != nil {
+		errs = append(errs, err)
+	}
+
+	// Close file handles.
+	if db.file != nil {
+		// No need to unlock read-only file.
+		if !db.readOnly {
+			// Unlock the file.
+			if err := funlock(db); err != nil {
+				errs = append(errs, fmt.Errorf("bolt.Close(): funlock error: %w", err))
+			}
+		}
+
+		// Close the file descriptor.
+		if err := db.file.Close(); err != nil {
+			errs = append(errs, fmt.Errorf("db file close: %w", err))
+		}
+		db.file = nil
+	}
+
+	db.path = ""
+
+	if len(errs) > 0 {
+		return errs[0]
+	}
+	return nil
+}
+
+// Begin starts a new transaction.
+// Multiple read-only transactions can be used concurrently but only one
+// write transaction can be used at a time. Starting multiple write transactions
+// will cause the calls to block and be serialized until the current write
+// transaction finishes.
+//
+// Transactions should not be dependent on one another. Opening a read
+// transaction and a write transaction in the same goroutine can cause the
+// writer to deadlock because the database periodically needs to re-mmap itself
+// as it grows and it cannot do that while a read transaction is open.
+//
+// If a long running read transaction (for example, a snapshot transaction) is
+// needed, you might want to set DB.InitialMmapSize to a large enough value
+// to avoid potential blocking of write transaction.
+//
+// IMPORTANT: You must close read-only transactions after you are finished or
+// else the database will not reclaim old pages.
+func (db *DB) Begin(writable bool) (t *Tx, err error) {
+	if lg := db.Logger(); lg != discardLogger {
+		lg.Debugf("Starting a new transaction [writable: %t]", writable)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Starting a new transaction [writable: %t] failed: %v", writable, err)
+			} else {
+				lg.Debugf("Starting a new transaction [writable: %t] successfully", writable)
+			}
+		}()
+	}
+
+	if writable {
+		return db.beginRWTx()
+	}
+	return db.beginTx()
+}
+
+func (db *DB) Logger() Logger {
+	if db == nil || db.logger == nil {
+		return getDiscardLogger()
+	}
+	return db.logger
+}
+
+func (db *DB) beginTx() (*Tx, error) {
+	// Lock the meta pages while we initialize the transaction. We obtain
+	// the meta lock before the mmap lock because that's the order that the
+	// write transaction will obtain them.
+	db.metalock.Lock()
+
+	// Obtain a read-only lock on the mmap. When the mmap is remapped it will
+	// obtain a write lock so all transactions must finish before it can be
+	// remapped.
+	db.mmaplock.RLock()
+
+	// Exit if the database is not open yet.
+	if !db.opened {
+		db.mmaplock.RUnlock()
+		db.metalock.Unlock()
+		return nil, berrors.ErrDatabaseNotOpen
+	}
+
+	// Exit if the database is not correctly mapped.
+	if db.data == nil {
+		db.mmaplock.RUnlock()
+		db.metalock.Unlock()
+		return nil, berrors.ErrInvalidMapping
+	}
+
+	// Create a transaction associated with the database.
+	t := &Tx{}
+	t.init(db)
+
+	// Keep track of transaction until it closes.
+	db.txs = append(db.txs, t)
+	n := len(db.txs)
+	if db.freelist != nil {
+		db.freelist.AddReadonlyTXID(t.meta.Txid())
+	}
+
+	// Unlock the meta pages.
+	db.metalock.Unlock()
+
+	// Update the transaction stats.
+	db.statlock.Lock()
+	db.stats.TxN++
+	db.stats.OpenTxN = n
+	db.statlock.Unlock()
+
+	return t, nil
+}
+
+func (db *DB) beginRWTx() (*Tx, error) {
+	// If the database was opened with Options.ReadOnly, return an error.
+	if db.readOnly {
+		return nil, berrors.ErrDatabaseReadOnly
+	}
+
+	// Obtain writer lock. This is released by the transaction when it closes.
+	// This enforces only one writer transaction at a time.
+	db.rwlock.Lock()
+
+	// Once we have the writer lock then we can lock the meta pages so that
+	// we can set up the transaction.
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
+	// Exit if the database is not open yet.
+	if !db.opened {
+		db.rwlock.Unlock()
+		return nil, berrors.ErrDatabaseNotOpen
+	}
+
+	// Exit if the database is not correctly mapped.
+	if db.data == nil {
+		db.rwlock.Unlock()
+		return nil, berrors.ErrInvalidMapping
+	}
+
+	// Create a transaction associated with the database.
+	t := &Tx{writable: true}
+	t.init(db)
+	db.rwtx = t
+	db.freelist.ReleasePendingPages()
+	return t, nil
+}
+
+// removeTx removes a transaction from the database.
+func (db *DB) removeTx(tx *Tx) {
+	// Release the read lock on the mmap.
+	db.mmaplock.RUnlock()
+
+	// Use the meta lock to restrict access to the DB object.
+	db.metalock.Lock()
+
+	// Remove the transaction.
+	for i, t := range db.txs {
+		if t == tx {
+			last := len(db.txs) - 1
+			db.txs[i] = db.txs[last]
+			db.txs[last] = nil
+			db.txs = db.txs[:last]
+			break
+		}
+	}
+	n := len(db.txs)
+	if db.freelist != nil {
+		db.freelist.RemoveReadonlyTXID(tx.meta.Txid())
+	}
+
+	// Unlock the meta pages.
+	db.metalock.Unlock()
+
+	// Merge statistics.
+	db.statlock.Lock()
+	db.stats.OpenTxN = n
+	db.stats.TxStats.add(&tx.stats)
+	db.statlock.Unlock()
+}
+
+// Update executes a function within the context of a read-write managed transaction.
+// If no error is returned from the function then the transaction is committed.
+// If an error is returned then the entire transaction is rolled back.
+// Any error that is returned from the function or returned from the commit is
+// returned from the Update() method.
+//
+// Attempting to manually commit or rollback within the function will cause a panic.
+func (db *DB) Update(fn func(*Tx) error) error {
+	t, err := db.Begin(true)
+	if err != nil {
+		return err
+	}
+
+	// Make sure the transaction rolls back in the event of a panic.
+	defer func() {
+		if t.db != nil {
+			t.rollback()
+		}
+	}()
+
+	// Mark as a managed tx so that the inner function cannot manually commit.
+	t.managed = true
+
+	// If an error is returned from the function then rollback and return error.
+	err = fn(t)
+	t.managed = false
+	if err != nil {
+		_ = t.Rollback()
+		return err
+	}
+
+	return t.Commit()
+}
+
+// View executes a function within the context of a managed read-only transaction.
+// Any error that is returned from the function is returned from the View() method.
+//
+// Attempting to manually rollback within the function will cause a panic.
+func (db *DB) View(fn func(*Tx) error) error {
+	t, err := db.Begin(false)
+	if err != nil {
+		return err
+	}
+
+	// Make sure the transaction rolls back in the event of a panic.
+	defer func() {
+		if t.db != nil {
+			t.rollback()
+		}
+	}()
+
+	// Mark as a managed tx so that the inner function cannot manually rollback.
+	t.managed = true
+
+	// If an error is returned from the function then pass it through.
+	err = fn(t)
+	t.managed = false
+	if err != nil {
+		_ = t.Rollback()
+		return err
+	}
+
+	return t.Rollback()
+}
+
+// Batch calls fn as part of a batch. It behaves similar to Update,
+// except:
+//
+// 1. concurrent Batch calls can be combined into a single Bolt
+// transaction.
+//
+// 2. the function passed to Batch may be called multiple times,
+// regardless of whether it returns error or not.
+//
+// This means that Batch function side effects must be idempotent and
+// take permanent effect only after a successful return is seen in
+// caller.
+//
+// The maximum batch size and delay can be adjusted with DB.MaxBatchSize
+// and DB.MaxBatchDelay, respectively.
+//
+// Batch is only useful when there are multiple goroutines calling it.
+func (db *DB) Batch(fn func(*Tx) error) error {
+	errCh := make(chan error, 1)
+
+	db.batchMu.Lock()
+	if (db.batch == nil) || (db.batch != nil && len(db.batch.calls) >= db.MaxBatchSize) {
+		// There is no existing batch, or the existing batch is full; start a new one.
+		db.batch = &batch{
+			db: db,
+		}
+		db.batch.timer = time.AfterFunc(db.MaxBatchDelay, db.batch.trigger)
+	}
+	db.batch.calls = append(db.batch.calls, call{fn: fn, err: errCh})
+	if len(db.batch.calls) >= db.MaxBatchSize {
+		// wake up batch, it's ready to run
+		go db.batch.trigger()
+	}
+	db.batchMu.Unlock()
+
+	err := <-errCh
+	if err == trySolo {
+		err = db.Update(fn)
+	}
+	return err
+}
+
+type call struct {
+	fn  func(*Tx) error
+	err chan<- error
+}
+
+type batch struct {
+	db    *DB
+	timer *time.Timer
+	start sync.Once
+	calls []call
+}
+
+// trigger runs the batch if it hasn't already been run.
+func (b *batch) trigger() {
+	b.start.Do(b.run)
+}
+
+// run performs the transactions in the batch and communicates results
+// back to DB.Batch.
+func (b *batch) run() {
+	b.db.batchMu.Lock()
+	b.timer.Stop()
+	// Make sure no new work is added to this batch, but don't break
+	// other batches.
+	if b.db.batch == b {
+		b.db.batch = nil
+	}
+	b.db.batchMu.Unlock()
+
+retry:
+	for len(b.calls) > 0 {
+		var failIdx = -1
+		err := b.db.Update(func(tx *Tx) error {
+			for i, c := range b.calls {
+				if err := safelyCall(c.fn, tx); err != nil {
+					failIdx = i
+					return err
+				}
+			}
+			return nil
+		})
+
+		if failIdx >= 0 {
+			// take the failing transaction out of the batch. it's
+			// safe to shorten b.calls here because db.batch no longer
+			// points to us, and we hold the mutex anyway.
+			c := b.calls[failIdx]
+			b.calls[failIdx], b.calls = b.calls[len(b.calls)-1], b.calls[:len(b.calls)-1]
+			// tell the submitter re-run it solo, continue with the rest of the batch
+			c.err <- trySolo
+			continue retry
+		}
+
+		// pass success, or bolt internal errors, to all callers
+		for _, c := range b.calls {
+			c.err <- err
+		}
+		break retry
+	}
+}
+
+// trySolo is a special sentinel error value used for signaling that a
+// transaction function should be re-run. It should never be seen by
+// callers.
+var trySolo = errors.New("batch function returned an error and should be re-run solo")
+
+type panicked struct {
+	reason interface{}
+}
+
+func (p panicked) Error() string {
+	if err, ok := p.reason.(error); ok {
+		return err.Error()
+	}
+	return fmt.Sprintf("panic: %v", p.reason)
+}
+
+func safelyCall(fn func(*Tx) error, tx *Tx) (err error) {
+	defer func() {
+		if p := recover(); p != nil {
+			err = panicked{p}
+		}
+	}()
+	return fn(tx)
+}
+
+// Sync executes fdatasync() against the database file handle.
+//
+// This is not necessary under normal operation, however, if you use NoSync
+// then it allows you to force the database file to sync against the disk.
+func (db *DB) Sync() (err error) {
+	if lg := db.Logger(); lg != discardLogger {
+		lg.Debugf("Syncing bbolt db (%s)", db.path)
+		defer func() {
+			if err != nil {
+				lg.Errorf("[GOOS: %s, GOARCH: %s] syncing bbolt db (%s) failed: %v", runtime.GOOS, runtime.GOARCH, db.path, err)
+			} else {
+				lg.Debugf("Syncing bbolt db (%s) successfully", db.path)
+			}
+		}()
+	}
+
+	return fdatasync(db)
+}
+
+// Stats retrieves ongoing performance stats for the database.
+// This is only updated when a transaction closes.
+func (db *DB) Stats() Stats {
+	db.statlock.RLock()
+	defer db.statlock.RUnlock()
+	return db.stats
+}
+
+// This is for internal access to the raw data bytes from the C cursor, use
+// carefully, or not at all.
+func (db *DB) Info() *Info {
+	common.Assert(db.data != nil, "database file isn't correctly mapped")
+	return &Info{uintptr(unsafe.Pointer(&db.data[0])), db.pageSize}
+}
+
+// page retrieves a page reference from the mmap based on the current page size.
+func (db *DB) page(id common.Pgid) *common.Page {
+	pos := id * common.Pgid(db.pageSize)
+	return (*common.Page)(unsafe.Pointer(&db.data[pos]))
+}
+
+// pageInBuffer retrieves a page reference from a given byte array based on the current page size.
+func (db *DB) pageInBuffer(b []byte, id common.Pgid) *common.Page {
+	return (*common.Page)(unsafe.Pointer(&b[id*common.Pgid(db.pageSize)]))
+}
+
+// meta retrieves the current meta page reference.
+func (db *DB) meta() *common.Meta {
+	// We have to return the meta with the highest txid which doesn't fail
+	// validation. Otherwise, we can cause errors when in fact the database is
+	// in a consistent state. metaA is the one with the higher txid.
+	metaA := db.meta0
+	metaB := db.meta1
+	if db.meta1.Txid() > db.meta0.Txid() {
+		metaA = db.meta1
+		metaB = db.meta0
+	}
+
+	// Use higher meta page if valid. Otherwise, fallback to previous, if valid.
+	if err := metaA.Validate(); err == nil {
+		return metaA
+	} else if err := metaB.Validate(); err == nil {
+		return metaB
+	}
+
+	// This should never be reached, because both meta1 and meta0 were validated
+	// on mmap() and we do fsync() on every write.
+	panic("bolt.DB.meta(): invalid meta pages")
+}
+
+// allocate returns a contiguous block of memory starting at a given page.
+func (db *DB) allocate(txid common.Txid, count int) (*common.Page, error) {
+	// Allocate a temporary buffer for the page.
+	var buf []byte
+	if count == 1 {
+		buf = db.pagePool.Get().([]byte)
+	} else {
+		buf = make([]byte, count*db.pageSize)
+	}
+	p := (*common.Page)(unsafe.Pointer(&buf[0]))
+	p.SetOverflow(uint32(count - 1))
+
+	// Use pages from the freelist if they are available.
+	p.SetId(db.freelist.Allocate(txid, count))
+	if p.Id() != 0 {
+		return p, nil
+	}
+
+	// Resize mmap() if we're at the end.
+	p.SetId(db.rwtx.meta.Pgid())
+	var minsz = int((p.Id()+common.Pgid(count))+1) * db.pageSize
+	if minsz >= db.datasz {
+		if err := db.mmap(minsz); err != nil {
+			return nil, fmt.Errorf("mmap allocate error: %s", err)
+		}
+	}
+
+	// Move the page id high water mark.
+	curPgid := db.rwtx.meta.Pgid()
+	db.rwtx.meta.SetPgid(curPgid + common.Pgid(count))
+
+	return p, nil
+}
+
+// grow grows the size of the database to the given sz.
+func (db *DB) grow(sz int) error {
+	// Ignore if the new size is less than available file size.
+	lg := db.Logger()
+	fileSize, err := db.fileSize()
+	if err != nil {
+		lg.Errorf("getting file size failed: %w", err)
+		return err
+	}
+	if sz <= fileSize {
+		return nil
+	}
+
+	// If the data is smaller than the alloc size then only allocate what's needed.
+	// Once it goes over the allocation size then allocate in chunks.
+	if db.datasz <= db.AllocSize {
+		sz = db.datasz
+	} else {
+		sz += db.AllocSize
+	}
+
+	// Truncate and fsync to ensure file size metadata is flushed.
+	// https://github.com/boltdb/bolt/issues/284
+	if !db.NoGrowSync && !db.readOnly {
+		if runtime.GOOS != "windows" {
+			// gofail: var resizeFileError string
+			// return errors.New(resizeFileError)
+			if err := db.file.Truncate(int64(sz)); err != nil {
+				lg.Errorf("[GOOS: %s, GOARCH: %s] truncating file failed, size: %d, db.datasz: %d, error: %v", runtime.GOOS, runtime.GOARCH, sz, db.datasz, err)
+				return fmt.Errorf("file resize error: %s", err)
+			}
+		}
+		if err := db.file.Sync(); err != nil {
+			lg.Errorf("[GOOS: %s, GOARCH: %s] syncing file failed, db.datasz: %d, error: %v", runtime.GOOS, runtime.GOARCH, db.datasz, err)
+			return fmt.Errorf("file sync error: %s", err)
+		}
+		if db.Mlock {
+			// unlock old file and lock new one
+			if err := db.mrelock(fileSize, sz); err != nil {
+				return fmt.Errorf("mlock/munlock error: %s", err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func (db *DB) IsReadOnly() bool {
+	return db.readOnly
+}
+
+func (db *DB) freepages() []common.Pgid {
+	tx, err := db.beginTx()
+	defer func() {
+		err = tx.Rollback()
+		if err != nil {
+			panic("freepages: failed to rollback tx")
+		}
+	}()
+	if err != nil {
+		panic("freepages: failed to open read only tx")
+	}
+
+	reachable := make(map[common.Pgid]*common.Page)
+	nofreed := make(map[common.Pgid]bool)
+	ech := make(chan error)
+	go func() {
+		for e := range ech {
+			panic(fmt.Sprintf("freepages: failed to get all reachable pages (%v)", e))
+		}
+	}()
+	tx.recursivelyCheckBucket(&tx.root, reachable, nofreed, HexKVStringer(), ech)
+	close(ech)
+
+	// TODO: If check bucket reported any corruptions (ech) we shouldn't proceed to freeing the pages.
+
+	var fids []common.Pgid
+	for i := common.Pgid(2); i < db.meta().Pgid(); i++ {
+		if _, ok := reachable[i]; !ok {
+			fids = append(fids, i)
+		}
+	}
+	return fids
+}
+
+func newFreelist(freelistType FreelistType) fl.Interface {
+	if freelistType == FreelistMapType {
+		return fl.NewHashMapFreelist()
+	}
+	return fl.NewArrayFreelist()
+}
+
+// Options represents the options that can be set when opening a database.
+type Options struct {
+	// Timeout is the amount of time to wait to obtain a file lock.
+	// When set to zero it will wait indefinitely.
+	Timeout time.Duration
+
+	// Sets the DB.NoGrowSync flag before memory mapping the file.
+	NoGrowSync bool
+
+	// Do not sync freelist to disk. This improves the database write performance
+	// under normal operation, but requires a full database re-sync during recovery.
+	NoFreelistSync bool
+
+	// PreLoadFreelist sets whether to load the free pages when opening
+	// the db file. Note when opening db in write mode, bbolt will always
+	// load the free pages.
+	PreLoadFreelist bool
+
+	// FreelistType sets the backend freelist type. There are two options. Array which is simple but endures
+	// dramatic performance degradation if database is large and fragmentation in freelist is common.
+	// The alternative one is using hashmap, it is faster in almost all circumstances
+	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
+	// The default type is array
+	FreelistType FreelistType
+
+	// Open database in read-only mode. Uses flock(..., LOCK_SH |LOCK_NB) to
+	// grab a shared lock (UNIX).
+	ReadOnly bool
+
+	// Sets the DB.MmapFlags flag before memory mapping the file.
+	MmapFlags int
+
+	// InitialMmapSize is the initial mmap size of the database
+	// in bytes. Read transactions won't block write transaction
+	// if the InitialMmapSize is large enough to hold database mmap
+	// size. (See DB.Begin for more information)
+	//
+	// If <=0, the initial map size is 0.
+	// If initialMmapSize is smaller than the previous database size,
+	// it takes no effect.
+	//
+	// Note: On Windows, due to platform limitations, the database file size
+	// will be immediately resized to match `InitialMmapSize` (aligned to page size)
+	// when the DB is opened. On non-Windows platforms, the file size will grow
+	// dynamically based on the actual amount of written data, regardless of `InitialMmapSize`.
+	// Refer to https://github.com/etcd-io/bbolt/issues/378#issuecomment-1378121966.
+	InitialMmapSize int
+
+	// PageSize overrides the default OS page size.
+	PageSize int
+
+	// NoSync sets the initial value of DB.NoSync. Normally this can just be
+	// set directly on the DB itself when returned from Open(), but this option
+	// is useful in APIs which expose Options but not the underlying DB.
+	NoSync bool
+
+	// OpenFile is used to open files. It defaults to os.OpenFile. This option
+	// is useful for writing hermetic tests.
+	OpenFile func(string, int, os.FileMode) (*os.File, error)
+
+	// Mlock locks database file in memory when set to true.
+	// It prevents potential page faults, however
+	// used memory can't be reclaimed. (UNIX only)
+	Mlock bool
+
+	// Logger is the logger used for bbolt.
+	Logger Logger
+}
+
+func (o *Options) String() string {
+	if o == nil {
+		return "{}"
+	}
+
+	return fmt.Sprintf("{Timeout: %s, NoGrowSync: %t, NoFreelistSync: %t, PreLoadFreelist: %t, FreelistType: %s, ReadOnly: %t, MmapFlags: %x, InitialMmapSize: %d, PageSize: %d, NoSync: %t, OpenFile: %p, Mlock: %t, Logger: %p}",
+		o.Timeout, o.NoGrowSync, o.NoFreelistSync, o.PreLoadFreelist, o.FreelistType, o.ReadOnly, o.MmapFlags, o.InitialMmapSize, o.PageSize, o.NoSync, o.OpenFile, o.Mlock, o.Logger)
+
+}
+
+// DefaultOptions represent the options used if nil options are passed into Open().
+// No timeout is used which will cause Bolt to wait indefinitely for a lock.
+var DefaultOptions = &Options{
+	Timeout:      0,
+	NoGrowSync:   false,
+	FreelistType: FreelistArrayType,
+}
+
+// Stats represents statistics about the database.
+type Stats struct {
+	// Put `TxStats` at the first field to ensure it's 64-bit aligned. Note
+	// that the first word in an allocated struct can be relied upon to be
+	// 64-bit aligned. Refer to https://pkg.go.dev/sync/atomic#pkg-note-BUG.
+	// Also refer to discussion in https://github.com/etcd-io/bbolt/issues/577.
+	TxStats TxStats // global, ongoing stats.
+
+	// Freelist stats
+	FreePageN     int // total number of free pages on the freelist
+	PendingPageN  int // total number of pending pages on the freelist
+	FreeAlloc     int // total bytes allocated in free pages
+	FreelistInuse int // total bytes used by the freelist
+
+	// Transaction stats
+	TxN     int // total number of started read transactions
+	OpenTxN int // number of currently open read transactions
+}
+
+// Sub calculates and returns the difference between two sets of database stats.
+// This is useful when obtaining stats at two different points and time and
+// you need the performance counters that occurred within that time span.
+func (s *Stats) Sub(other *Stats) Stats {
+	if other == nil {
+		return *s
+	}
+	var diff Stats
+	diff.FreePageN = s.FreePageN
+	diff.PendingPageN = s.PendingPageN
+	diff.FreeAlloc = s.FreeAlloc
+	diff.FreelistInuse = s.FreelistInuse
+	diff.TxN = s.TxN - other.TxN
+	diff.TxStats = s.TxStats.Sub(&other.TxStats)
+	return diff
+}
+
+type Info struct {
+	Data     uintptr
+	PageSize int
+}
diff --git a/vendor/go.etcd.io/bbolt/doc.go b/vendor/go.etcd.io/bbolt/doc.go
new file mode 100644
index 0000000..d1007e4
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/doc.go
@@ -0,0 +1,40 @@
+/*
+package bbolt implements a low-level key/value store in pure Go. It supports
+fully serializable transactions, ACID semantics, and lock-free MVCC with
+multiple readers and a single writer. Bolt can be used for projects that
+want a simple data store without the need to add large dependencies such as
+Postgres or MySQL.
+
+Bolt is a single-level, zero-copy, B+tree data store. This means that Bolt is
+optimized for fast read access and does not require recovery in the event of a
+system crash. Transactions which have not finished committing will simply be
+rolled back in the event of a crash.
+
+The design of Bolt is based on Howard Chu's LMDB database project.
+
+Bolt currently works on Windows, Mac OS X, and Linux.
+
+# Basics
+
+There are only a few types in Bolt: DB, Bucket, Tx, and Cursor. The DB is
+a collection of buckets and is represented by a single file on disk. A bucket is
+a collection of unique keys that are associated with values.
+
+Transactions provide either read-only or read-write access to the database.
+Read-only transactions can retrieve key/value pairs and can use Cursors to
+iterate over the dataset sequentially. Read-write transactions can create and
+delete buckets and can insert and remove keys. Only one read-write transaction
+is allowed at a time.
+
+# Caveats
+
+The database uses a read-only, memory-mapped data file to ensure that
+applications cannot corrupt the database, however, this means that keys and
+values returned from Bolt cannot be changed. Writing to a read-only byte slice
+will cause Go to panic.
+
+Keys and values retrieved from the database are only valid for the life of
+the transaction. When used outside the transaction, these byte slices can
+point to different data or can point to invalid memory which will cause a panic.
+*/
+package bbolt
diff --git a/vendor/go.etcd.io/bbolt/errors.go b/vendor/go.etcd.io/bbolt/errors.go
new file mode 100644
index 0000000..02958c8
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/errors.go
@@ -0,0 +1,108 @@
+package bbolt
+
+import "go.etcd.io/bbolt/errors"
+
+// These errors can be returned when opening or calling methods on a DB.
+var (
+	// ErrDatabaseNotOpen is returned when a DB instance is accessed before it
+	// is opened or after it is closed.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrDatabaseNotOpen = errors.ErrDatabaseNotOpen
+
+	// ErrInvalid is returned when both meta pages on a database are invalid.
+	// This typically occurs when a file is not a bolt database.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrInvalid = errors.ErrInvalid
+
+	// ErrInvalidMapping is returned when the database file fails to get mapped.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrInvalidMapping = errors.ErrInvalidMapping
+
+	// ErrVersionMismatch is returned when the data file was created with a
+	// different version of Bolt.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrVersionMismatch = errors.ErrVersionMismatch
+
+	// ErrChecksum is returned when a checksum mismatch occurs on either of the two meta pages.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrChecksum = errors.ErrChecksum
+
+	// ErrTimeout is returned when a database cannot obtain an exclusive lock
+	// on the data file after the timeout passed to Open().
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrTimeout = errors.ErrTimeout
+)
+
+// These errors can occur when beginning or committing a Tx.
+var (
+	// ErrTxNotWritable is returned when performing a write operation on a
+	// read-only transaction.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrTxNotWritable = errors.ErrTxNotWritable
+
+	// ErrTxClosed is returned when committing or rolling back a transaction
+	// that has already been committed or rolled back.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrTxClosed = errors.ErrTxClosed
+
+	// ErrDatabaseReadOnly is returned when a mutating transaction is started on a
+	// read-only database.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrDatabaseReadOnly = errors.ErrDatabaseReadOnly
+
+	// ErrFreePagesNotLoaded is returned when a readonly transaction without
+	// preloading the free pages is trying to access the free pages.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrFreePagesNotLoaded = errors.ErrFreePagesNotLoaded
+)
+
+// These errors can occur when putting or deleting a value or a bucket.
+var (
+	// ErrBucketNotFound is returned when trying to access a bucket that has
+	// not been created yet.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrBucketNotFound = errors.ErrBucketNotFound
+
+	// ErrBucketExists is returned when creating a bucket that already exists.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrBucketExists = errors.ErrBucketExists
+
+	// ErrBucketNameRequired is returned when creating a bucket with a blank name.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrBucketNameRequired = errors.ErrBucketNameRequired
+
+	// ErrKeyRequired is returned when inserting a zero-length key.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrKeyRequired = errors.ErrKeyRequired
+
+	// ErrKeyTooLarge is returned when inserting a key that is larger than MaxKeySize.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrKeyTooLarge = errors.ErrKeyTooLarge
+
+	// ErrValueTooLarge is returned when inserting a value that is larger than MaxValueSize.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrValueTooLarge = errors.ErrValueTooLarge
+
+	// ErrIncompatibleValue is returned when trying create or delete a bucket
+	// on an existing non-bucket key or when trying to create or delete a
+	// non-bucket key on an existing bucket key.
+	//
+	// Deprecated: Use the error variables defined in the bbolt/errors package.
+	ErrIncompatibleValue = errors.ErrIncompatibleValue
+)
diff --git a/vendor/go.etcd.io/bbolt/errors/errors.go b/vendor/go.etcd.io/bbolt/errors/errors.go
new file mode 100644
index 0000000..c115289
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/errors/errors.go
@@ -0,0 +1,84 @@
+// Package errors defines the error variables that may be returned
+// during bbolt operations.
+package errors
+
+import "errors"
+
+// These errors can be returned when opening or calling methods on a DB.
+var (
+	// ErrDatabaseNotOpen is returned when a DB instance is accessed before it
+	// is opened or after it is closed.
+	ErrDatabaseNotOpen = errors.New("database not open")
+
+	// ErrInvalid is returned when both meta pages on a database are invalid.
+	// This typically occurs when a file is not a bolt database.
+	ErrInvalid = errors.New("invalid database")
+
+	// ErrInvalidMapping is returned when the database file fails to get mapped.
+	ErrInvalidMapping = errors.New("database isn't correctly mapped")
+
+	// ErrVersionMismatch is returned when the data file was created with a
+	// different version of Bolt.
+	ErrVersionMismatch = errors.New("version mismatch")
+
+	// ErrChecksum is returned when a checksum mismatch occurs on either of the two meta pages.
+	ErrChecksum = errors.New("checksum error")
+
+	// ErrTimeout is returned when a database cannot obtain an exclusive lock
+	// on the data file after the timeout passed to Open().
+	ErrTimeout = errors.New("timeout")
+)
+
+// These errors can occur when beginning or committing a Tx.
+var (
+	// ErrTxNotWritable is returned when performing a write operation on a
+	// read-only transaction.
+	ErrTxNotWritable = errors.New("tx not writable")
+
+	// ErrTxClosed is returned when committing or rolling back a transaction
+	// that has already been committed or rolled back.
+	ErrTxClosed = errors.New("tx closed")
+
+	// ErrDatabaseReadOnly is returned when a mutating transaction is started on a
+	// read-only database.
+	ErrDatabaseReadOnly = errors.New("database is in read-only mode")
+
+	// ErrFreePagesNotLoaded is returned when a readonly transaction without
+	// preloading the free pages is trying to access the free pages.
+	ErrFreePagesNotLoaded = errors.New("free pages are not pre-loaded")
+)
+
+// These errors can occur when putting or deleting a value or a bucket.
+var (
+	// ErrBucketNotFound is returned when trying to access a bucket that has
+	// not been created yet.
+	ErrBucketNotFound = errors.New("bucket not found")
+
+	// ErrBucketExists is returned when creating a bucket that already exists.
+	ErrBucketExists = errors.New("bucket already exists")
+
+	// ErrBucketNameRequired is returned when creating a bucket with a blank name.
+	ErrBucketNameRequired = errors.New("bucket name required")
+
+	// ErrKeyRequired is returned when inserting a zero-length key.
+	ErrKeyRequired = errors.New("key required")
+
+	// ErrKeyTooLarge is returned when inserting a key that is larger than MaxKeySize.
+	ErrKeyTooLarge = errors.New("key too large")
+
+	// ErrValueTooLarge is returned when inserting a value that is larger than MaxValueSize.
+	ErrValueTooLarge = errors.New("value too large")
+
+	// ErrIncompatibleValue is returned when trying to create or delete a bucket
+	// on an existing non-bucket key or when trying to create or delete a
+	// non-bucket key on an existing bucket key.
+	ErrIncompatibleValue = errors.New("incompatible value")
+
+	// ErrSameBuckets is returned when trying to move a sub-bucket between
+	// source and target buckets, while source and target buckets are the same.
+	ErrSameBuckets = errors.New("the source and target are the same bucket")
+
+	// ErrDifferentDB is returned when trying to move a sub-bucket between
+	// source and target buckets, while source and target buckets are in different database files.
+	ErrDifferentDB = errors.New("the source and target buckets are in different database files")
+)
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_386.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_386.go
new file mode 100644
index 0000000..773175d
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_386.go
@@ -0,0 +1,7 @@
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0x7FFFFFFF // 2GB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0xFFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_amd64.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_amd64.go
new file mode 100644
index 0000000..9f27d91
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_amd64.go
@@ -0,0 +1,7 @@
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_arm.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_arm.go
new file mode 100644
index 0000000..773175d
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_arm.go
@@ -0,0 +1,7 @@
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0x7FFFFFFF // 2GB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0xFFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_arm64.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_arm64.go
new file mode 100644
index 0000000..9022f6b
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_arm64.go
@@ -0,0 +1,9 @@
+//go:build arm64
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_loong64.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_loong64.go
new file mode 100644
index 0000000..3127752
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_loong64.go
@@ -0,0 +1,9 @@
+//go:build loong64
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_mips64x.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_mips64x.go
new file mode 100644
index 0000000..d930f4e
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_mips64x.go
@@ -0,0 +1,9 @@
+//go:build mips64 || mips64le
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0x8000000000 // 512GB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_mipsx.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_mipsx.go
new file mode 100644
index 0000000..8b19343
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_mipsx.go
@@ -0,0 +1,9 @@
+//go:build mips || mipsle
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0x40000000 // 1GB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0xFFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc.go
new file mode 100644
index 0000000..a374e14
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc.go
@@ -0,0 +1,9 @@
+//go:build ppc
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0x7FFFFFFF // 2GB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0xFFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64.go
new file mode 100644
index 0000000..80288a8
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64.go
@@ -0,0 +1,9 @@
+//go:build ppc64
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64le.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64le.go
new file mode 100644
index 0000000..77561d6
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_ppc64le.go
@@ -0,0 +1,9 @@
+//go:build ppc64le
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_riscv64.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_riscv64.go
new file mode 100644
index 0000000..2a876e5
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_riscv64.go
@@ -0,0 +1,9 @@
+//go:build riscv64
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bolt_s390x.go b/vendor/go.etcd.io/bbolt/internal/common/bolt_s390x.go
new file mode 100644
index 0000000..982cb75
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bolt_s390x.go
@@ -0,0 +1,9 @@
+//go:build s390x
+
+package common
+
+// MaxMapSize represents the largest mmap size supported by Bolt.
+const MaxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// MaxAllocSize is the size used when creating array pointers.
+const MaxAllocSize = 0x7FFFFFFF
diff --git a/vendor/go.etcd.io/bbolt/internal/common/bucket.go b/vendor/go.etcd.io/bbolt/internal/common/bucket.go
new file mode 100644
index 0000000..2b4ab14
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/bucket.go
@@ -0,0 +1,54 @@
+package common
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+const BucketHeaderSize = int(unsafe.Sizeof(InBucket{}))
+
+// InBucket represents the on-file representation of a bucket.
+// This is stored as the "value" of a bucket key. If the bucket is small enough,
+// then its root page can be stored inline in the "value", after the bucket
+// header. In the case of inline buckets, the "root" will be 0.
+type InBucket struct {
+	root     Pgid   // page id of the bucket's root-level page
+	sequence uint64 // monotonically incrementing, used by NextSequence()
+}
+
+func NewInBucket(root Pgid, seq uint64) InBucket {
+	return InBucket{
+		root:     root,
+		sequence: seq,
+	}
+}
+
+func (b *InBucket) RootPage() Pgid {
+	return b.root
+}
+
+func (b *InBucket) SetRootPage(id Pgid) {
+	b.root = id
+}
+
+// InSequence returns the sequence. The reason why not naming it `Sequence`
+// is to avoid duplicated name as `(*Bucket) Sequence()`
+func (b *InBucket) InSequence() uint64 {
+	return b.sequence
+}
+
+func (b *InBucket) SetInSequence(v uint64) {
+	b.sequence = v
+}
+
+func (b *InBucket) IncSequence() {
+	b.sequence++
+}
+
+func (b *InBucket) InlinePage(v []byte) *Page {
+	return (*Page)(unsafe.Pointer(&v[BucketHeaderSize]))
+}
+
+func (b *InBucket) String() string {
+	return fmt.Sprintf("<pgid=%d,seq=%d>", b.root, b.sequence)
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/inode.go b/vendor/go.etcd.io/bbolt/internal/common/inode.go
new file mode 100644
index 0000000..080b9af
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/inode.go
@@ -0,0 +1,115 @@
+package common
+
+import "unsafe"
+
+// Inode represents an internal node inside of a node.
+// It can be used to point to elements in a page or point
+// to an element which hasn't been added to a page yet.
+type Inode struct {
+	flags uint32
+	pgid  Pgid
+	key   []byte
+	value []byte
+}
+
+type Inodes []Inode
+
+func (in *Inode) Flags() uint32 {
+	return in.flags
+}
+
+func (in *Inode) SetFlags(flags uint32) {
+	in.flags = flags
+}
+
+func (in *Inode) Pgid() Pgid {
+	return in.pgid
+}
+
+func (in *Inode) SetPgid(id Pgid) {
+	in.pgid = id
+}
+
+func (in *Inode) Key() []byte {
+	return in.key
+}
+
+func (in *Inode) SetKey(key []byte) {
+	in.key = key
+}
+
+func (in *Inode) Value() []byte {
+	return in.value
+}
+
+func (in *Inode) SetValue(value []byte) {
+	in.value = value
+}
+
+func ReadInodeFromPage(p *Page) Inodes {
+	inodes := make(Inodes, int(p.Count()))
+	isLeaf := p.IsLeafPage()
+	for i := 0; i < int(p.Count()); i++ {
+		inode := &inodes[i]
+		if isLeaf {
+			elem := p.LeafPageElement(uint16(i))
+			inode.SetFlags(elem.Flags())
+			inode.SetKey(elem.Key())
+			inode.SetValue(elem.Value())
+		} else {
+			elem := p.BranchPageElement(uint16(i))
+			inode.SetPgid(elem.Pgid())
+			inode.SetKey(elem.Key())
+		}
+		Assert(len(inode.Key()) > 0, "read: zero-length inode key")
+	}
+
+	return inodes
+}
+
+func WriteInodeToPage(inodes Inodes, p *Page) uint32 {
+	// Loop over each item and write it to the page.
+	// off tracks the offset into p of the start of the next data.
+	off := unsafe.Sizeof(*p) + p.PageElementSize()*uintptr(len(inodes))
+	isLeaf := p.IsLeafPage()
+	for i, item := range inodes {
+		Assert(len(item.Key()) > 0, "write: zero-length inode key")
+
+		// Create a slice to write into of needed size and advance
+		// byte pointer for next iteration.
+		sz := len(item.Key()) + len(item.Value())
+		b := UnsafeByteSlice(unsafe.Pointer(p), off, 0, sz)
+		off += uintptr(sz)
+
+		// Write the page element.
+		if isLeaf {
+			elem := p.LeafPageElement(uint16(i))
+			elem.SetPos(uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem))))
+			elem.SetFlags(item.Flags())
+			elem.SetKsize(uint32(len(item.Key())))
+			elem.SetVsize(uint32(len(item.Value())))
+		} else {
+			elem := p.BranchPageElement(uint16(i))
+			elem.SetPos(uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem))))
+			elem.SetKsize(uint32(len(item.Key())))
+			elem.SetPgid(item.Pgid())
+			Assert(elem.Pgid() != p.Id(), "write: circular dependency occurred")
+		}
+
+		// Write data for the element to the end of the page.
+		l := copy(b, item.Key())
+		copy(b[l:], item.Value())
+	}
+
+	return uint32(off)
+}
+
+func UsedSpaceInPage(inodes Inodes, p *Page) uint32 {
+	off := unsafe.Sizeof(*p) + p.PageElementSize()*uintptr(len(inodes))
+	for _, item := range inodes {
+		sz := len(item.Key()) + len(item.Value())
+		off += uintptr(sz)
+	}
+
+	return uint32(off)
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/meta.go b/vendor/go.etcd.io/bbolt/internal/common/meta.go
new file mode 100644
index 0000000..0553886
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/meta.go
@@ -0,0 +1,161 @@
+package common
+
+import (
+	"fmt"
+	"hash/fnv"
+	"io"
+	"unsafe"
+
+	"go.etcd.io/bbolt/errors"
+)
+
+type Meta struct {
+	magic    uint32
+	version  uint32
+	pageSize uint32
+	flags    uint32
+	root     InBucket
+	freelist Pgid
+	pgid     Pgid
+	txid     Txid
+	checksum uint64
+}
+
+// Validate checks the marker bytes and version of the meta page to ensure it matches this binary.
+func (m *Meta) Validate() error {
+	if m.magic != Magic {
+		return errors.ErrInvalid
+	} else if m.version != Version {
+		return errors.ErrVersionMismatch
+	} else if m.checksum != m.Sum64() {
+		return errors.ErrChecksum
+	}
+	return nil
+}
+
+// Copy copies one meta object to another.
+func (m *Meta) Copy(dest *Meta) {
+	*dest = *m
+}
+
+// Write writes the meta onto a page.
+func (m *Meta) Write(p *Page) {
+	if m.root.root >= m.pgid {
+		panic(fmt.Sprintf("root bucket pgid (%d) above high water mark (%d)", m.root.root, m.pgid))
+	} else if m.freelist >= m.pgid && m.freelist != PgidNoFreelist {
+		// TODO: reject pgidNoFreeList if !NoFreelistSync
+		panic(fmt.Sprintf("freelist pgid (%d) above high water mark (%d)", m.freelist, m.pgid))
+	}
+
+	// Page id is either going to be 0 or 1 which we can determine by the transaction ID.
+	p.id = Pgid(m.txid % 2)
+	p.SetFlags(MetaPageFlag)
+
+	// Calculate the checksum.
+	m.checksum = m.Sum64()
+
+	m.Copy(p.Meta())
+}
+
+// Sum64 generates the checksum for the meta.
+func (m *Meta) Sum64() uint64 {
+	var h = fnv.New64a()
+	_, _ = h.Write((*[unsafe.Offsetof(Meta{}.checksum)]byte)(unsafe.Pointer(m))[:])
+	return h.Sum64()
+}
+
+func (m *Meta) Magic() uint32 {
+	return m.magic
+}
+
+func (m *Meta) SetMagic(v uint32) {
+	m.magic = v
+}
+
+func (m *Meta) Version() uint32 {
+	return m.version
+}
+
+func (m *Meta) SetVersion(v uint32) {
+	m.version = v
+}
+
+func (m *Meta) PageSize() uint32 {
+	return m.pageSize
+}
+
+func (m *Meta) SetPageSize(v uint32) {
+	m.pageSize = v
+}
+
+func (m *Meta) Flags() uint32 {
+	return m.flags
+}
+
+func (m *Meta) SetFlags(v uint32) {
+	m.flags = v
+}
+
+func (m *Meta) SetRootBucket(b InBucket) {
+	m.root = b
+}
+
+func (m *Meta) RootBucket() *InBucket {
+	return &m.root
+}
+
+func (m *Meta) Freelist() Pgid {
+	return m.freelist
+}
+
+func (m *Meta) SetFreelist(v Pgid) {
+	m.freelist = v
+}
+
+func (m *Meta) IsFreelistPersisted() bool {
+	return m.freelist != PgidNoFreelist
+}
+
+func (m *Meta) Pgid() Pgid {
+	return m.pgid
+}
+
+func (m *Meta) SetPgid(id Pgid) {
+	m.pgid = id
+}
+
+func (m *Meta) Txid() Txid {
+	return m.txid
+}
+
+func (m *Meta) SetTxid(id Txid) {
+	m.txid = id
+}
+
+func (m *Meta) IncTxid() {
+	m.txid += 1
+}
+
+func (m *Meta) DecTxid() {
+	m.txid -= 1
+}
+
+func (m *Meta) Checksum() uint64 {
+	return m.checksum
+}
+
+func (m *Meta) SetChecksum(v uint64) {
+	m.checksum = v
+}
+
+func (m *Meta) Print(w io.Writer) {
+	fmt.Fprintf(w, "Version:    %d\n", m.version)
+	fmt.Fprintf(w, "Page Size:  %d bytes\n", m.pageSize)
+	fmt.Fprintf(w, "Flags:      %08x\n", m.flags)
+	fmt.Fprintf(w, "Root:       <pgid=%d>\n", m.root.root)
+	fmt.Fprintf(w, "Freelist:   <pgid=%d>\n", m.freelist)
+	fmt.Fprintf(w, "HWM:        <pgid=%d>\n", m.pgid)
+	fmt.Fprintf(w, "Txn ID:     %d\n", m.txid)
+	fmt.Fprintf(w, "Checksum:   %016x\n", m.checksum)
+	fmt.Fprintf(w, "\n")
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/page.go b/vendor/go.etcd.io/bbolt/internal/common/page.go
new file mode 100644
index 0000000..ee80896
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/page.go
@@ -0,0 +1,391 @@
+package common
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"unsafe"
+)
+
+const PageHeaderSize = unsafe.Sizeof(Page{})
+
+const MinKeysPerPage = 2
+
+const BranchPageElementSize = unsafe.Sizeof(branchPageElement{})
+const LeafPageElementSize = unsafe.Sizeof(leafPageElement{})
+const pgidSize = unsafe.Sizeof(Pgid(0))
+
+const (
+	BranchPageFlag   = 0x01
+	LeafPageFlag     = 0x02
+	MetaPageFlag     = 0x04
+	FreelistPageFlag = 0x10
+)
+
+const (
+	BucketLeafFlag = 0x01
+)
+
+type Pgid uint64
+
+type Page struct {
+	id       Pgid
+	flags    uint16
+	count    uint16
+	overflow uint32
+}
+
+func NewPage(id Pgid, flags, count uint16, overflow uint32) *Page {
+	return &Page{
+		id:       id,
+		flags:    flags,
+		count:    count,
+		overflow: overflow,
+	}
+}
+
+// Typ returns a human-readable page type string used for debugging.
+func (p *Page) Typ() string {
+	if p.IsBranchPage() {
+		return "branch"
+	} else if p.IsLeafPage() {
+		return "leaf"
+	} else if p.IsMetaPage() {
+		return "meta"
+	} else if p.IsFreelistPage() {
+		return "freelist"
+	}
+	return fmt.Sprintf("unknown<%02x>", p.flags)
+}
+
+func (p *Page) IsBranchPage() bool {
+	return p.flags == BranchPageFlag
+}
+
+func (p *Page) IsLeafPage() bool {
+	return p.flags == LeafPageFlag
+}
+
+func (p *Page) IsMetaPage() bool {
+	return p.flags == MetaPageFlag
+}
+
+func (p *Page) IsFreelistPage() bool {
+	return p.flags == FreelistPageFlag
+}
+
+// Meta returns a pointer to the metadata section of the page.
+func (p *Page) Meta() *Meta {
+	return (*Meta)(UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p)))
+}
+
+func (p *Page) FastCheck(id Pgid) {
+	Assert(p.id == id, "Page expected to be: %v, but self identifies as %v", id, p.id)
+	// Only one flag of page-type can be set.
+	Assert(p.IsBranchPage() ||
+		p.IsLeafPage() ||
+		p.IsMetaPage() ||
+		p.IsFreelistPage(),
+		"page %v: has unexpected type/flags: %x", p.id, p.flags)
+}
+
+// LeafPageElement retrieves the leaf node by index
+func (p *Page) LeafPageElement(index uint16) *leafPageElement {
+	return (*leafPageElement)(UnsafeIndex(unsafe.Pointer(p), unsafe.Sizeof(*p),
+		LeafPageElementSize, int(index)))
+}
+
+// LeafPageElements retrieves a list of leaf nodes.
+func (p *Page) LeafPageElements() []leafPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	data := UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+	elems := unsafe.Slice((*leafPageElement)(data), int(p.count))
+	return elems
+}
+
+// BranchPageElement retrieves the branch node by index
+func (p *Page) BranchPageElement(index uint16) *branchPageElement {
+	return (*branchPageElement)(UnsafeIndex(unsafe.Pointer(p), unsafe.Sizeof(*p),
+		unsafe.Sizeof(branchPageElement{}), int(index)))
+}
+
+// BranchPageElements retrieves a list of branch nodes.
+func (p *Page) BranchPageElements() []branchPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	data := UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+	elems := unsafe.Slice((*branchPageElement)(data), int(p.count))
+	return elems
+}
+
+func (p *Page) FreelistPageCount() (int, int) {
+	Assert(p.IsFreelistPage(), fmt.Sprintf("can't get freelist page count from a non-freelist page: %2x", p.flags))
+
+	// If the page.count is at the max uint16 value (64k) then it's considered
+	// an overflow and the size of the freelist is stored as the first element.
+	var idx, count = 0, int(p.count)
+	if count == 0xFFFF {
+		idx = 1
+		c := *(*Pgid)(UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p)))
+		count = int(c)
+		if count < 0 {
+			panic(fmt.Sprintf("leading element count %d overflows int", c))
+		}
+	}
+
+	return idx, count
+}
+
+func (p *Page) FreelistPageIds() []Pgid {
+	Assert(p.IsFreelistPage(), fmt.Sprintf("can't get freelist page IDs from a non-freelist page: %2x", p.flags))
+
+	idx, count := p.FreelistPageCount()
+
+	if count == 0 {
+		return nil
+	}
+
+	data := UnsafeIndex(unsafe.Pointer(p), unsafe.Sizeof(*p), pgidSize, idx)
+	ids := unsafe.Slice((*Pgid)(data), count)
+
+	return ids
+}
+
+// dump writes n bytes of the page to STDERR as hex output.
+func (p *Page) hexdump(n int) {
+	buf := UnsafeByteSlice(unsafe.Pointer(p), 0, 0, n)
+	fmt.Fprintf(os.Stderr, "%x\n", buf)
+}
+
+func (p *Page) PageElementSize() uintptr {
+	if p.IsLeafPage() {
+		return LeafPageElementSize
+	}
+	return BranchPageElementSize
+}
+
+func (p *Page) Id() Pgid {
+	return p.id
+}
+
+func (p *Page) SetId(target Pgid) {
+	p.id = target
+}
+
+func (p *Page) Flags() uint16 {
+	return p.flags
+}
+
+func (p *Page) SetFlags(v uint16) {
+	p.flags = v
+}
+
+func (p *Page) Count() uint16 {
+	return p.count
+}
+
+func (p *Page) SetCount(target uint16) {
+	p.count = target
+}
+
+func (p *Page) Overflow() uint32 {
+	return p.overflow
+}
+
+func (p *Page) SetOverflow(target uint32) {
+	p.overflow = target
+}
+
+func (p *Page) String() string {
+	return fmt.Sprintf("ID: %d, Type: %s, count: %d, overflow: %d", p.id, p.Typ(), p.count, p.overflow)
+}
+
+type Pages []*Page
+
+func (s Pages) Len() int           { return len(s) }
+func (s Pages) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s Pages) Less(i, j int) bool { return s[i].id < s[j].id }
+
+// branchPageElement represents a node on a branch page.
+type branchPageElement struct {
+	pos   uint32
+	ksize uint32
+	pgid  Pgid
+}
+
+func (n *branchPageElement) Pos() uint32 {
+	return n.pos
+}
+
+func (n *branchPageElement) SetPos(v uint32) {
+	n.pos = v
+}
+
+func (n *branchPageElement) Ksize() uint32 {
+	return n.ksize
+}
+
+func (n *branchPageElement) SetKsize(v uint32) {
+	n.ksize = v
+}
+
+func (n *branchPageElement) Pgid() Pgid {
+	return n.pgid
+}
+
+func (n *branchPageElement) SetPgid(v Pgid) {
+	n.pgid = v
+}
+
+// Key returns a byte slice of the node key.
+func (n *branchPageElement) Key() []byte {
+	return UnsafeByteSlice(unsafe.Pointer(n), 0, int(n.pos), int(n.pos)+int(n.ksize))
+}
+
+// leafPageElement represents a node on a leaf page.
+type leafPageElement struct {
+	flags uint32
+	pos   uint32
+	ksize uint32
+	vsize uint32
+}
+
+func NewLeafPageElement(flags, pos, ksize, vsize uint32) *leafPageElement {
+	return &leafPageElement{
+		flags: flags,
+		pos:   pos,
+		ksize: ksize,
+		vsize: vsize,
+	}
+}
+
+func (n *leafPageElement) Flags() uint32 {
+	return n.flags
+}
+
+func (n *leafPageElement) SetFlags(v uint32) {
+	n.flags = v
+}
+
+func (n *leafPageElement) Pos() uint32 {
+	return n.pos
+}
+
+func (n *leafPageElement) SetPos(v uint32) {
+	n.pos = v
+}
+
+func (n *leafPageElement) Ksize() uint32 {
+	return n.ksize
+}
+
+func (n *leafPageElement) SetKsize(v uint32) {
+	n.ksize = v
+}
+
+func (n *leafPageElement) Vsize() uint32 {
+	return n.vsize
+}
+
+func (n *leafPageElement) SetVsize(v uint32) {
+	n.vsize = v
+}
+
+// Key returns a byte slice of the node key.
+func (n *leafPageElement) Key() []byte {
+	i := int(n.pos)
+	j := i + int(n.ksize)
+	return UnsafeByteSlice(unsafe.Pointer(n), 0, i, j)
+}
+
+// Value returns a byte slice of the node value.
+func (n *leafPageElement) Value() []byte {
+	i := int(n.pos) + int(n.ksize)
+	j := i + int(n.vsize)
+	return UnsafeByteSlice(unsafe.Pointer(n), 0, i, j)
+}
+
+func (n *leafPageElement) IsBucketEntry() bool {
+	return n.flags&uint32(BucketLeafFlag) != 0
+}
+
+func (n *leafPageElement) Bucket() *InBucket {
+	if n.IsBucketEntry() {
+		return LoadBucket(n.Value())
+	} else {
+		return nil
+	}
+}
+
+// PageInfo represents human readable information about a page.
+type PageInfo struct {
+	ID            int
+	Type          string
+	Count         int
+	OverflowCount int
+}
+
+type Pgids []Pgid
+
+func (s Pgids) Len() int           { return len(s) }
+func (s Pgids) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s Pgids) Less(i, j int) bool { return s[i] < s[j] }
+
+// Merge returns the sorted union of a and b.
+func (a Pgids) Merge(b Pgids) Pgids {
+	// Return the opposite slice if one is nil.
+	if len(a) == 0 {
+		return b
+	}
+	if len(b) == 0 {
+		return a
+	}
+	merged := make(Pgids, len(a)+len(b))
+	Mergepgids(merged, a, b)
+	return merged
+}
+
+// Mergepgids copies the sorted union of a and b into dst.
+// If dst is too small, it panics.
+func Mergepgids(dst, a, b Pgids) {
+	if len(dst) < len(a)+len(b) {
+		panic(fmt.Errorf("mergepgids bad len %d < %d + %d", len(dst), len(a), len(b)))
+	}
+	// Copy in the opposite slice if one is nil.
+	if len(a) == 0 {
+		copy(dst, b)
+		return
+	}
+	if len(b) == 0 {
+		copy(dst, a)
+		return
+	}
+
+	// Merged will hold all elements from both lists.
+	merged := dst[:0]
+
+	// Assign lead to the slice with a lower starting value, follow to the higher value.
+	lead, follow := a, b
+	if b[0] < a[0] {
+		lead, follow = b, a
+	}
+
+	// Continue while there are elements in the lead.
+	for len(lead) > 0 {
+		// Merge largest prefix of lead that is ahead of follow[0].
+		n := sort.Search(len(lead), func(i int) bool { return lead[i] > follow[0] })
+		merged = append(merged, lead[:n]...)
+		if n >= len(lead) {
+			break
+		}
+
+		// Swap lead and follow.
+		lead, follow = follow, lead[n:]
+	}
+
+	// Append what's left in follow.
+	_ = append(merged, follow...)
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/types.go b/vendor/go.etcd.io/bbolt/internal/common/types.go
new file mode 100644
index 0000000..18d6d69
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/types.go
@@ -0,0 +1,37 @@
+package common
+
+import (
+	"os"
+	"runtime"
+	"time"
+)
+
+// MaxMmapStep is the largest step that can be taken when remapping the mmap.
+const MaxMmapStep = 1 << 30 // 1GB
+
+// Version represents the data file format version.
+const Version uint32 = 2
+
+// Magic represents a marker value to indicate that a file is a Bolt DB.
+const Magic uint32 = 0xED0CDAED
+
+const PgidNoFreelist Pgid = 0xffffffffffffffff
+
+// IgnoreNoSync specifies whether the NoSync field of a DB is ignored when
+// syncing changes to a file.  This is required as some operating systems,
+// such as OpenBSD, do not have a unified buffer cache (UBC) and writes
+// must be synchronized using the msync(2) syscall.
+const IgnoreNoSync = runtime.GOOS == "openbsd"
+
+// Default values if not set in a DB instance.
+const (
+	DefaultMaxBatchSize  int = 1000
+	DefaultMaxBatchDelay     = 10 * time.Millisecond
+	DefaultAllocSize         = 16 * 1024 * 1024
+)
+
+// DefaultPageSize is the default page size for db which is set to the OS page size.
+var DefaultPageSize = os.Getpagesize()
+
+// Txid represents the internal transaction identifier.
+type Txid uint64
diff --git a/vendor/go.etcd.io/bbolt/internal/common/unsafe.go b/vendor/go.etcd.io/bbolt/internal/common/unsafe.go
new file mode 100644
index 0000000..740ffc7
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/unsafe.go
@@ -0,0 +1,27 @@
+package common
+
+import (
+	"unsafe"
+)
+
+func UnsafeAdd(base unsafe.Pointer, offset uintptr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(base) + offset)
+}
+
+func UnsafeIndex(base unsafe.Pointer, offset uintptr, elemsz uintptr, n int) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(base) + offset + uintptr(n)*elemsz)
+}
+
+func UnsafeByteSlice(base unsafe.Pointer, offset uintptr, i, j int) []byte {
+	// See: https://github.com/golang/go/wiki/cgo#turning-c-arrays-into-go-slices
+	//
+	// This memory is not allocated from C, but it is unmanaged by Go's
+	// garbage collector and should behave similarly, and the compiler
+	// should produce similar code.  Note that this conversion allows a
+	// subslice to begin after the base address, with an optional offset,
+	// while the URL above does not cover this case and only slices from
+	// index 0.  However, the wiki never says that the address must be to
+	// the beginning of a C allocation (or even that malloc was used at
+	// all), so this is believed to be correct.
+	return (*[MaxAllocSize]byte)(UnsafeAdd(base, offset))[i:j:j]
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/utils.go b/vendor/go.etcd.io/bbolt/internal/common/utils.go
new file mode 100644
index 0000000..bdf82a7
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/utils.go
@@ -0,0 +1,64 @@
+package common
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"unsafe"
+)
+
+func LoadBucket(buf []byte) *InBucket {
+	return (*InBucket)(unsafe.Pointer(&buf[0]))
+}
+
+func LoadPage(buf []byte) *Page {
+	return (*Page)(unsafe.Pointer(&buf[0]))
+}
+
+func LoadPageMeta(buf []byte) *Meta {
+	return (*Meta)(unsafe.Pointer(&buf[PageHeaderSize]))
+}
+
+func CopyFile(srcPath, dstPath string) error {
+	// Ensure source file exists.
+	_, err := os.Stat(srcPath)
+	if os.IsNotExist(err) {
+		return fmt.Errorf("source file %q not found", srcPath)
+	} else if err != nil {
+		return err
+	}
+
+	// Ensure output file not exist.
+	_, err = os.Stat(dstPath)
+	if err == nil {
+		return fmt.Errorf("output file %q already exists", dstPath)
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+
+	srcDB, err := os.Open(srcPath)
+	if err != nil {
+		return fmt.Errorf("failed to open source file %q: %w", srcPath, err)
+	}
+	defer srcDB.Close()
+	dstDB, err := os.Create(dstPath)
+	if err != nil {
+		return fmt.Errorf("failed to create output file %q: %w", dstPath, err)
+	}
+	defer dstDB.Close()
+	written, err := io.Copy(dstDB, srcDB)
+	if err != nil {
+		return fmt.Errorf("failed to copy database file from %q to %q: %w", srcPath, dstPath, err)
+	}
+
+	srcFi, err := srcDB.Stat()
+	if err != nil {
+		return fmt.Errorf("failed to get source file info %q: %w", srcPath, err)
+	}
+	initialSize := srcFi.Size()
+	if initialSize != written {
+		return fmt.Errorf("the byte copied (%q: %d) isn't equal to the initial db size (%q: %d)", dstPath, written, srcPath, initialSize)
+	}
+
+	return nil
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/common/verify.go b/vendor/go.etcd.io/bbolt/internal/common/verify.go
new file mode 100644
index 0000000..eac95e2
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/common/verify.go
@@ -0,0 +1,67 @@
+// Copied from https://github.com/etcd-io/etcd/blob/main/client/pkg/verify/verify.go
+package common
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+const ENV_VERIFY = "BBOLT_VERIFY"
+
+type VerificationType string
+
+const (
+	ENV_VERIFY_VALUE_ALL    VerificationType = "all"
+	ENV_VERIFY_VALUE_ASSERT VerificationType = "assert"
+)
+
+func getEnvVerify() string {
+	return strings.ToLower(os.Getenv(ENV_VERIFY))
+}
+
+func IsVerificationEnabled(verification VerificationType) bool {
+	env := getEnvVerify()
+	return env == string(ENV_VERIFY_VALUE_ALL) || env == strings.ToLower(string(verification))
+}
+
+// EnableVerifications sets `ENV_VERIFY` and returns a function that
+// can be used to bring the original settings.
+func EnableVerifications(verification VerificationType) func() {
+	previousEnv := getEnvVerify()
+	os.Setenv(ENV_VERIFY, string(verification))
+	return func() {
+		os.Setenv(ENV_VERIFY, previousEnv)
+	}
+}
+
+// EnableAllVerifications enables verification and returns a function
+// that can be used to bring the original settings.
+func EnableAllVerifications() func() {
+	return EnableVerifications(ENV_VERIFY_VALUE_ALL)
+}
+
+// DisableVerifications unsets `ENV_VERIFY` and returns a function that
+// can be used to bring the original settings.
+func DisableVerifications() func() {
+	previousEnv := getEnvVerify()
+	os.Unsetenv(ENV_VERIFY)
+	return func() {
+		os.Setenv(ENV_VERIFY, previousEnv)
+	}
+}
+
+// Verify performs verification if the assertions are enabled.
+// In the default setup running in tests and skipped in the production code.
+func Verify(f func()) {
+	if IsVerificationEnabled(ENV_VERIFY_VALUE_ASSERT) {
+		f()
+	}
+}
+
+// Assert will panic with a given formatted message if the given condition is false.
+func Assert(condition bool, msg string, v ...any) {
+	if !condition {
+		panic(fmt.Sprintf("assertion failed: "+msg, v...))
+	}
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/freelist/array.go b/vendor/go.etcd.io/bbolt/internal/freelist/array.go
new file mode 100644
index 0000000..0cc1ba7
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/freelist/array.go
@@ -0,0 +1,108 @@
+package freelist
+
+import (
+	"fmt"
+	"sort"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+type array struct {
+	*shared
+
+	ids []common.Pgid // all free and available free page ids.
+}
+
+func (f *array) Init(ids common.Pgids) {
+	f.ids = ids
+	f.reindex()
+}
+
+func (f *array) Allocate(txid common.Txid, n int) common.Pgid {
+	if len(f.ids) == 0 {
+		return 0
+	}
+
+	var initial, previd common.Pgid
+	for i, id := range f.ids {
+		if id <= 1 {
+			panic(fmt.Sprintf("invalid page allocation: %d", id))
+		}
+
+		// Reset initial page if this is not contiguous.
+		if previd == 0 || id-previd != 1 {
+			initial = id
+		}
+
+		// If we found a contiguous block then remove it and return it.
+		if (id-initial)+1 == common.Pgid(n) {
+			// If we're allocating off the beginning then take the fast path
+			// and just adjust the existing slice. This will use extra memory
+			// temporarily but the append() in free() will realloc the slice
+			// as is necessary.
+			if (i + 1) == n {
+				f.ids = f.ids[i+1:]
+			} else {
+				copy(f.ids[i-n+1:], f.ids[i+1:])
+				f.ids = f.ids[:len(f.ids)-n]
+			}
+
+			// Remove from the free cache.
+			for i := common.Pgid(0); i < common.Pgid(n); i++ {
+				delete(f.cache, initial+i)
+			}
+			f.allocs[initial] = txid
+			return initial
+		}
+
+		previd = id
+	}
+	return 0
+}
+
+func (f *array) FreeCount() int {
+	return len(f.ids)
+}
+
+func (f *array) freePageIds() common.Pgids {
+	return f.ids
+}
+
+func (f *array) mergeSpans(ids common.Pgids) {
+	sort.Sort(ids)
+	common.Verify(func() {
+		idsIdx := make(map[common.Pgid]struct{})
+		for _, id := range f.ids {
+			// The existing f.ids shouldn't have duplicated free ID.
+			if _, ok := idsIdx[id]; ok {
+				panic(fmt.Sprintf("detected duplicated free page ID: %d in existing f.ids: %v", id, f.ids))
+			}
+			idsIdx[id] = struct{}{}
+		}
+
+		prev := common.Pgid(0)
+		for _, id := range ids {
+			// The ids shouldn't have duplicated free ID. Note page 0 and 1
+			// are reserved for meta pages, so they can never be free page IDs.
+			if prev == id {
+				panic(fmt.Sprintf("detected duplicated free ID: %d in ids: %v", id, ids))
+			}
+			prev = id
+
+			// The ids shouldn't have any overlap with the existing f.ids.
+			if _, ok := idsIdx[id]; ok {
+				panic(fmt.Sprintf("detected overlapped free page ID: %d between ids: %v and existing f.ids: %v", id, ids, f.ids))
+			}
+		}
+	})
+	f.ids = common.Pgids(f.ids).Merge(ids)
+}
+
+func NewArrayFreelist() Interface {
+	a := &array{
+		shared: newShared(),
+		ids:    []common.Pgid{},
+	}
+	a.Interface = a
+	return a
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/freelist/freelist.go b/vendor/go.etcd.io/bbolt/internal/freelist/freelist.go
new file mode 100644
index 0000000..2b81950
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/freelist/freelist.go
@@ -0,0 +1,82 @@
+package freelist
+
+import (
+	"go.etcd.io/bbolt/internal/common"
+)
+
+type ReadWriter interface {
+	// Read calls Init with the page ids stored in the given page.
+	Read(page *common.Page)
+
+	// Write writes the freelist into the given page.
+	Write(page *common.Page)
+
+	// EstimatedWritePageSize returns the size in bytes of the freelist after serialization in Write.
+	// This should never underestimate the size.
+	EstimatedWritePageSize() int
+}
+
+type Interface interface {
+	ReadWriter
+
+	// Init initializes this freelist with the given list of pages.
+	Init(ids common.Pgids)
+
+	// Allocate tries to allocate the given number of contiguous pages
+	// from the free list pages. It returns the starting page ID if
+	// available; otherwise, it returns 0.
+	Allocate(txid common.Txid, numPages int) common.Pgid
+
+	// Count returns the number of free and pending pages.
+	Count() int
+
+	// FreeCount returns the number of free pages.
+	FreeCount() int
+
+	// PendingCount returns the number of pending pages.
+	PendingCount() int
+
+	// AddReadonlyTXID adds a given read-only transaction id for pending page tracking.
+	AddReadonlyTXID(txid common.Txid)
+
+	// RemoveReadonlyTXID removes a given read-only transaction id for pending page tracking.
+	RemoveReadonlyTXID(txid common.Txid)
+
+	// ReleasePendingPages releases any pages associated with closed read-only transactions.
+	ReleasePendingPages()
+
+	// Free releases a page and its overflow for a given transaction id.
+	// If the page is already free or is one of the meta pages, then a panic will occur.
+	Free(txId common.Txid, p *common.Page)
+
+	// Freed returns whether a given page is in the free list.
+	Freed(pgId common.Pgid) bool
+
+	// Rollback removes the pages from a given pending tx.
+	Rollback(txId common.Txid)
+
+	// Copyall copies a list of all free ids and all pending ids in one sorted list.
+	// f.count returns the minimum length required for dst.
+	Copyall(dst []common.Pgid)
+
+	// Reload reads the freelist from a page and filters out pending items.
+	Reload(p *common.Page)
+
+	// NoSyncReload reads the freelist from Pgids and filters out pending items.
+	NoSyncReload(pgIds common.Pgids)
+
+	// freePageIds returns the IDs of all free pages. Returns an empty slice if no free pages are available.
+	freePageIds() common.Pgids
+
+	// pendingPageIds returns all pending pages by transaction id.
+	pendingPageIds() map[common.Txid]*txPending
+
+	// release moves all page ids for a transaction id (or older) to the freelist.
+	release(txId common.Txid)
+
+	// releaseRange moves pending pages allocated within an extent [begin,end] to the free list.
+	releaseRange(begin, end common.Txid)
+
+	// mergeSpans is merging the given pages into the freelist
+	mergeSpans(ids common.Pgids)
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/freelist/hashmap.go b/vendor/go.etcd.io/bbolt/internal/freelist/hashmap.go
new file mode 100644
index 0000000..8d471f4
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/freelist/hashmap.go
@@ -0,0 +1,292 @@
+package freelist
+
+import (
+	"fmt"
+	"reflect"
+	"sort"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// pidSet holds the set of starting pgids which have the same span size
+type pidSet map[common.Pgid]struct{}
+
+type hashMap struct {
+	*shared
+
+	freePagesCount uint64                 // count of free pages(hashmap version)
+	freemaps       map[uint64]pidSet      // key is the size of continuous pages(span), value is a set which contains the starting pgids of same size
+	forwardMap     map[common.Pgid]uint64 // key is start pgid, value is its span size
+	backwardMap    map[common.Pgid]uint64 // key is end pgid, value is its span size
+}
+
+func (f *hashMap) Init(pgids common.Pgids) {
+	// reset the counter when freelist init
+	f.freePagesCount = 0
+	f.freemaps = make(map[uint64]pidSet)
+	f.forwardMap = make(map[common.Pgid]uint64)
+	f.backwardMap = make(map[common.Pgid]uint64)
+
+	if len(pgids) == 0 {
+		return
+	}
+
+	if !sort.SliceIsSorted([]common.Pgid(pgids), func(i, j int) bool { return pgids[i] < pgids[j] }) {
+		panic("pgids not sorted")
+	}
+
+	size := uint64(1)
+	start := pgids[0]
+
+	for i := 1; i < len(pgids); i++ {
+		// continuous page
+		if pgids[i] == pgids[i-1]+1 {
+			size++
+		} else {
+			f.addSpan(start, size)
+
+			size = 1
+			start = pgids[i]
+		}
+	}
+
+	// init the tail
+	if size != 0 && start != 0 {
+		f.addSpan(start, size)
+	}
+
+	f.reindex()
+}
+
+func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
+	if n == 0 {
+		return 0
+	}
+
+	// if we have a exact size match just return short path
+	if bm, ok := f.freemaps[uint64(n)]; ok {
+		for pid := range bm {
+			// remove the span
+			f.delSpan(pid, uint64(n))
+
+			f.allocs[pid] = txid
+
+			for i := common.Pgid(0); i < common.Pgid(n); i++ {
+				delete(f.cache, pid+i)
+			}
+			return pid
+		}
+	}
+
+	// lookup the map to find larger span
+	for size, bm := range f.freemaps {
+		if size < uint64(n) {
+			continue
+		}
+
+		for pid := range bm {
+			// remove the initial
+			f.delSpan(pid, size)
+
+			f.allocs[pid] = txid
+
+			remain := size - uint64(n)
+
+			// add remain span
+			f.addSpan(pid+common.Pgid(n), remain)
+
+			for i := common.Pgid(0); i < common.Pgid(n); i++ {
+				delete(f.cache, pid+i)
+			}
+			return pid
+		}
+	}
+
+	return 0
+}
+
+func (f *hashMap) FreeCount() int {
+	common.Verify(func() {
+		expectedFreePageCount := f.hashmapFreeCountSlow()
+		common.Assert(int(f.freePagesCount) == expectedFreePageCount,
+			"freePagesCount (%d) is out of sync with free pages map (%d)", f.freePagesCount, expectedFreePageCount)
+	})
+	return int(f.freePagesCount)
+}
+
+func (f *hashMap) freePageIds() common.Pgids {
+	count := f.FreeCount()
+	if count == 0 {
+		return common.Pgids{}
+	}
+
+	m := make([]common.Pgid, 0, count)
+
+	startPageIds := make([]common.Pgid, 0, len(f.forwardMap))
+	for k := range f.forwardMap {
+		startPageIds = append(startPageIds, k)
+	}
+	sort.Sort(common.Pgids(startPageIds))
+
+	for _, start := range startPageIds {
+		if size, ok := f.forwardMap[start]; ok {
+			for i := 0; i < int(size); i++ {
+				m = append(m, start+common.Pgid(i))
+			}
+		}
+	}
+
+	return m
+}
+
+func (f *hashMap) hashmapFreeCountSlow() int {
+	count := 0
+	for _, size := range f.forwardMap {
+		count += int(size)
+	}
+	return count
+}
+
+func (f *hashMap) addSpan(start common.Pgid, size uint64) {
+	f.backwardMap[start-1+common.Pgid(size)] = size
+	f.forwardMap[start] = size
+	if _, ok := f.freemaps[size]; !ok {
+		f.freemaps[size] = make(map[common.Pgid]struct{})
+	}
+
+	f.freemaps[size][start] = struct{}{}
+	f.freePagesCount += size
+}
+
+func (f *hashMap) delSpan(start common.Pgid, size uint64) {
+	delete(f.forwardMap, start)
+	delete(f.backwardMap, start+common.Pgid(size-1))
+	delete(f.freemaps[size], start)
+	if len(f.freemaps[size]) == 0 {
+		delete(f.freemaps, size)
+	}
+	f.freePagesCount -= size
+}
+
+func (f *hashMap) mergeSpans(ids common.Pgids) {
+	common.Verify(func() {
+		ids1Freemap := f.idsFromFreemaps()
+		ids2Forward := f.idsFromForwardMap()
+		ids3Backward := f.idsFromBackwardMap()
+
+		if !reflect.DeepEqual(ids1Freemap, ids2Forward) {
+			panic(fmt.Sprintf("Detected mismatch, f.freemaps: %v, f.forwardMap: %v", f.freemaps, f.forwardMap))
+		}
+		if !reflect.DeepEqual(ids1Freemap, ids3Backward) {
+			panic(fmt.Sprintf("Detected mismatch, f.freemaps: %v, f.backwardMap: %v", f.freemaps, f.backwardMap))
+		}
+
+		sort.Sort(ids)
+		prev := common.Pgid(0)
+		for _, id := range ids {
+			// The ids shouldn't have duplicated free ID.
+			if prev == id {
+				panic(fmt.Sprintf("detected duplicated free ID: %d in ids: %v", id, ids))
+			}
+			prev = id
+
+			// The ids shouldn't have any overlap with the existing f.freemaps.
+			if _, ok := ids1Freemap[id]; ok {
+				panic(fmt.Sprintf("detected overlapped free page ID: %d between ids: %v and existing f.freemaps: %v", id, ids, f.freemaps))
+			}
+		}
+	})
+	for _, id := range ids {
+		// try to see if we can merge and update
+		f.mergeWithExistingSpan(id)
+	}
+}
+
+// mergeWithExistingSpan merges pid to the existing free spans, try to merge it backward and forward
+func (f *hashMap) mergeWithExistingSpan(pid common.Pgid) {
+	prev := pid - 1
+	next := pid + 1
+
+	preSize, mergeWithPrev := f.backwardMap[prev]
+	nextSize, mergeWithNext := f.forwardMap[next]
+	newStart := pid
+	newSize := uint64(1)
+
+	if mergeWithPrev {
+		//merge with previous span
+		start := prev + 1 - common.Pgid(preSize)
+		f.delSpan(start, preSize)
+
+		newStart -= common.Pgid(preSize)
+		newSize += preSize
+	}
+
+	if mergeWithNext {
+		// merge with next span
+		f.delSpan(next, nextSize)
+		newSize += nextSize
+	}
+
+	f.addSpan(newStart, newSize)
+}
+
+// idsFromFreemaps get all free page IDs from f.freemaps.
+// used by test only.
+func (f *hashMap) idsFromFreemaps() map[common.Pgid]struct{} {
+	ids := make(map[common.Pgid]struct{})
+	for size, idSet := range f.freemaps {
+		for start := range idSet {
+			for i := 0; i < int(size); i++ {
+				id := start + common.Pgid(i)
+				if _, ok := ids[id]; ok {
+					panic(fmt.Sprintf("detected duplicated free page ID: %d in f.freemaps: %v", id, f.freemaps))
+				}
+				ids[id] = struct{}{}
+			}
+		}
+	}
+	return ids
+}
+
+// idsFromForwardMap get all free page IDs from f.forwardMap.
+// used by test only.
+func (f *hashMap) idsFromForwardMap() map[common.Pgid]struct{} {
+	ids := make(map[common.Pgid]struct{})
+	for start, size := range f.forwardMap {
+		for i := 0; i < int(size); i++ {
+			id := start + common.Pgid(i)
+			if _, ok := ids[id]; ok {
+				panic(fmt.Sprintf("detected duplicated free page ID: %d in f.forwardMap: %v", id, f.forwardMap))
+			}
+			ids[id] = struct{}{}
+		}
+	}
+	return ids
+}
+
+// idsFromBackwardMap get all free page IDs from f.backwardMap.
+// used by test only.
+func (f *hashMap) idsFromBackwardMap() map[common.Pgid]struct{} {
+	ids := make(map[common.Pgid]struct{})
+	for end, size := range f.backwardMap {
+		for i := 0; i < int(size); i++ {
+			id := end - common.Pgid(i)
+			if _, ok := ids[id]; ok {
+				panic(fmt.Sprintf("detected duplicated free page ID: %d in f.backwardMap: %v", id, f.backwardMap))
+			}
+			ids[id] = struct{}{}
+		}
+	}
+	return ids
+}
+
+func NewHashMapFreelist() Interface {
+	hm := &hashMap{
+		shared:      newShared(),
+		freemaps:    make(map[uint64]pidSet),
+		forwardMap:  make(map[common.Pgid]uint64),
+		backwardMap: make(map[common.Pgid]uint64),
+	}
+	hm.Interface = hm
+	return hm
+}
diff --git a/vendor/go.etcd.io/bbolt/internal/freelist/shared.go b/vendor/go.etcd.io/bbolt/internal/freelist/shared.go
new file mode 100644
index 0000000..f2d1130
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/internal/freelist/shared.go
@@ -0,0 +1,310 @@
+package freelist
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"unsafe"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+type txPending struct {
+	ids              []common.Pgid
+	alloctx          []common.Txid // txids allocating the ids
+	lastReleaseBegin common.Txid   // beginning txid of last matching releaseRange
+}
+
+type shared struct {
+	Interface
+
+	readonlyTXIDs []common.Txid               // all readonly transaction IDs.
+	allocs        map[common.Pgid]common.Txid // mapping of Txid that allocated a pgid.
+	cache         map[common.Pgid]struct{}    // fast lookup of all free and pending page ids.
+	pending       map[common.Txid]*txPending  // mapping of soon-to-be free page ids by tx.
+}
+
+func newShared() *shared {
+	return &shared{
+		pending: make(map[common.Txid]*txPending),
+		allocs:  make(map[common.Pgid]common.Txid),
+		cache:   make(map[common.Pgid]struct{}),
+	}
+}
+
+func (t *shared) pendingPageIds() map[common.Txid]*txPending {
+	return t.pending
+}
+
+func (t *shared) PendingCount() int {
+	var count int
+	for _, txp := range t.pending {
+		count += len(txp.ids)
+	}
+	return count
+}
+
+func (t *shared) Count() int {
+	return t.FreeCount() + t.PendingCount()
+}
+
+func (t *shared) Freed(pgId common.Pgid) bool {
+	_, ok := t.cache[pgId]
+	return ok
+}
+
+func (t *shared) Free(txid common.Txid, p *common.Page) {
+	if p.Id() <= 1 {
+		panic(fmt.Sprintf("cannot free page 0 or 1: %d", p.Id()))
+	}
+
+	// Free page and all its overflow pages.
+	txp := t.pending[txid]
+	if txp == nil {
+		txp = &txPending{}
+		t.pending[txid] = txp
+	}
+	allocTxid, ok := t.allocs[p.Id()]
+	common.Verify(func() {
+		if allocTxid == txid {
+			panic(fmt.Sprintf("free: freed page (%d) was allocated by the same transaction (%d)", p.Id(), txid))
+		}
+	})
+	if ok {
+		delete(t.allocs, p.Id())
+	}
+
+	for id := p.Id(); id <= p.Id()+common.Pgid(p.Overflow()); id++ {
+		// Verify that page is not already free.
+		if _, ok := t.cache[id]; ok {
+			panic(fmt.Sprintf("page %d already freed", id))
+		}
+		// Add to the freelist and cache.
+		txp.ids = append(txp.ids, id)
+		txp.alloctx = append(txp.alloctx, allocTxid)
+		t.cache[id] = struct{}{}
+	}
+}
+
+func (t *shared) Rollback(txid common.Txid) {
+	// Remove page ids from cache.
+	txp := t.pending[txid]
+	if txp == nil {
+		return
+	}
+	for i, pgid := range txp.ids {
+		delete(t.cache, pgid)
+		tx := txp.alloctx[i]
+		if tx == 0 {
+			continue
+		}
+		if tx != txid {
+			// Pending free aborted; restore page back to alloc list.
+			t.allocs[pgid] = tx
+		} else {
+			// A writing TXN should never free a page which was allocated by itself.
+			panic(fmt.Sprintf("rollback: freed page (%d) was allocated by the same transaction (%d)", pgid, txid))
+		}
+	}
+	// Remove pages from pending list and mark as free if allocated by txid.
+	delete(t.pending, txid)
+
+	// Remove pgids which are allocated by this txid
+	for pgid, tid := range t.allocs {
+		if tid == txid {
+			delete(t.allocs, pgid)
+		}
+	}
+}
+
+func (t *shared) AddReadonlyTXID(tid common.Txid) {
+	t.readonlyTXIDs = append(t.readonlyTXIDs, tid)
+}
+
+func (t *shared) RemoveReadonlyTXID(tid common.Txid) {
+	for i := range t.readonlyTXIDs {
+		if t.readonlyTXIDs[i] == tid {
+			last := len(t.readonlyTXIDs) - 1
+			t.readonlyTXIDs[i] = t.readonlyTXIDs[last]
+			t.readonlyTXIDs = t.readonlyTXIDs[:last]
+			break
+		}
+	}
+}
+
+type txIDx []common.Txid
+
+func (t txIDx) Len() int           { return len(t) }
+func (t txIDx) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
+func (t txIDx) Less(i, j int) bool { return t[i] < t[j] }
+
+func (t *shared) ReleasePendingPages() {
+	// Free all pending pages prior to the earliest open transaction.
+	sort.Sort(txIDx(t.readonlyTXIDs))
+	minid := common.Txid(math.MaxUint64)
+	if len(t.readonlyTXIDs) > 0 {
+		minid = t.readonlyTXIDs[0]
+	}
+	if minid > 0 {
+		t.release(minid - 1)
+	}
+	// Release unused txid extents.
+	for _, tid := range t.readonlyTXIDs {
+		t.releaseRange(minid, tid-1)
+		minid = tid + 1
+	}
+	t.releaseRange(minid, common.Txid(math.MaxUint64))
+	// Any page both allocated and freed in an extent is safe to release.
+}
+
+func (t *shared) release(txid common.Txid) {
+	m := make(common.Pgids, 0)
+	for tid, txp := range t.pending {
+		if tid <= txid {
+			// Move transaction's pending pages to the available freelist.
+			// Don't remove from the cache since the page is still free.
+			m = append(m, txp.ids...)
+			delete(t.pending, tid)
+		}
+	}
+	t.mergeSpans(m)
+}
+
+func (t *shared) releaseRange(begin, end common.Txid) {
+	if begin > end {
+		return
+	}
+	m := common.Pgids{}
+	for tid, txp := range t.pending {
+		if tid < begin || tid > end {
+			continue
+		}
+		// Don't recompute freed pages if ranges haven't updated.
+		if txp.lastReleaseBegin == begin {
+			continue
+		}
+		for i := 0; i < len(txp.ids); i++ {
+			if atx := txp.alloctx[i]; atx < begin || atx > end {
+				continue
+			}
+			m = append(m, txp.ids[i])
+			txp.ids[i] = txp.ids[len(txp.ids)-1]
+			txp.ids = txp.ids[:len(txp.ids)-1]
+			txp.alloctx[i] = txp.alloctx[len(txp.alloctx)-1]
+			txp.alloctx = txp.alloctx[:len(txp.alloctx)-1]
+			i--
+		}
+		txp.lastReleaseBegin = begin
+		if len(txp.ids) == 0 {
+			delete(t.pending, tid)
+		}
+	}
+	t.mergeSpans(m)
+}
+
+// Copyall copies a list of all free ids and all pending ids in one sorted list.
+// f.count returns the minimum length required for dst.
+func (t *shared) Copyall(dst []common.Pgid) {
+	m := make(common.Pgids, 0, t.PendingCount())
+	for _, txp := range t.pendingPageIds() {
+		m = append(m, txp.ids...)
+	}
+	sort.Sort(m)
+	common.Mergepgids(dst, t.freePageIds(), m)
+}
+
+func (t *shared) Reload(p *common.Page) {
+	t.Read(p)
+	t.NoSyncReload(t.freePageIds())
+}
+
+func (t *shared) NoSyncReload(pgIds common.Pgids) {
+	// Build a cache of only pending pages.
+	pcache := make(map[common.Pgid]bool)
+	for _, txp := range t.pending {
+		for _, pendingID := range txp.ids {
+			pcache[pendingID] = true
+		}
+	}
+
+	// Check each page in the freelist and build a new available freelist
+	// with any pages not in the pending lists.
+	a := []common.Pgid{}
+	for _, id := range pgIds {
+		if !pcache[id] {
+			a = append(a, id)
+		}
+	}
+
+	t.Init(a)
+}
+
+// reindex rebuilds the free cache based on available and pending free lists.
+func (t *shared) reindex() {
+	free := t.freePageIds()
+	pending := t.pendingPageIds()
+	t.cache = make(map[common.Pgid]struct{}, len(free))
+	for _, id := range free {
+		t.cache[id] = struct{}{}
+	}
+	for _, txp := range pending {
+		for _, pendingID := range txp.ids {
+			t.cache[pendingID] = struct{}{}
+		}
+	}
+}
+
+func (t *shared) Read(p *common.Page) {
+	if !p.IsFreelistPage() {
+		panic(fmt.Sprintf("invalid freelist page: %d, page type is %s", p.Id(), p.Typ()))
+	}
+
+	ids := p.FreelistPageIds()
+
+	// Copy the list of page ids from the freelist.
+	if len(ids) == 0 {
+		t.Init([]common.Pgid{})
+	} else {
+		// copy the ids, so we don't modify on the freelist page directly
+		idsCopy := make([]common.Pgid, len(ids))
+		copy(idsCopy, ids)
+		// Make sure they're sorted.
+		sort.Sort(common.Pgids(idsCopy))
+
+		t.Init(idsCopy)
+	}
+}
+
+func (t *shared) EstimatedWritePageSize() int {
+	n := t.Count()
+	if n >= 0xFFFF {
+		// The first element will be used to store the count. See freelist.write.
+		n++
+	}
+	return int(common.PageHeaderSize) + (int(unsafe.Sizeof(common.Pgid(0))) * n)
+}
+
+func (t *shared) Write(p *common.Page) {
+	// Combine the old free pgids and pgids waiting on an open transaction.
+
+	// Update the header flag.
+	p.SetFlags(common.FreelistPageFlag)
+
+	// The page.count can only hold up to 64k elements so if we overflow that
+	// number then we handle it by putting the size in the first element.
+	l := t.Count()
+	if l == 0 {
+		p.SetCount(uint16(l))
+	} else if l < 0xFFFF {
+		p.SetCount(uint16(l))
+		data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+		ids := unsafe.Slice((*common.Pgid)(data), l)
+		t.Copyall(ids)
+	} else {
+		p.SetCount(0xFFFF)
+		data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+		ids := unsafe.Slice((*common.Pgid)(data), l+1)
+		ids[0] = common.Pgid(l)
+		t.Copyall(ids[1:])
+	}
+}
diff --git a/vendor/go.etcd.io/bbolt/logger.go b/vendor/go.etcd.io/bbolt/logger.go
new file mode 100644
index 0000000..fb25089
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/logger.go
@@ -0,0 +1,113 @@
+package bbolt
+
+// See https://github.com/etcd-io/raft/blob/main/logger.go
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+type Logger interface {
+	Debug(v ...interface{})
+	Debugf(format string, v ...interface{})
+
+	Error(v ...interface{})
+	Errorf(format string, v ...interface{})
+
+	Info(v ...interface{})
+	Infof(format string, v ...interface{})
+
+	Warning(v ...interface{})
+	Warningf(format string, v ...interface{})
+
+	Fatal(v ...interface{})
+	Fatalf(format string, v ...interface{})
+
+	Panic(v ...interface{})
+	Panicf(format string, v ...interface{})
+}
+
+func getDiscardLogger() Logger {
+	return discardLogger
+}
+
+var (
+	discardLogger = &DefaultLogger{Logger: log.New(io.Discard, "", 0)}
+)
+
+const (
+	calldepth = 2
+)
+
+// DefaultLogger is a default implementation of the Logger interface.
+type DefaultLogger struct {
+	*log.Logger
+	debug bool
+}
+
+func (l *DefaultLogger) EnableTimestamps() {
+	l.SetFlags(l.Flags() | log.Ldate | log.Ltime)
+}
+
+func (l *DefaultLogger) EnableDebug() {
+	l.debug = true
+}
+
+func (l *DefaultLogger) Debug(v ...interface{}) {
+	if l.debug {
+		_ = l.Output(calldepth, header("DEBUG", fmt.Sprint(v...)))
+	}
+}
+
+func (l *DefaultLogger) Debugf(format string, v ...interface{}) {
+	if l.debug {
+		_ = l.Output(calldepth, header("DEBUG", fmt.Sprintf(format, v...)))
+	}
+}
+
+func (l *DefaultLogger) Info(v ...interface{}) {
+	_ = l.Output(calldepth, header("INFO", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Infof(format string, v ...interface{}) {
+	_ = l.Output(calldepth, header("INFO", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Error(v ...interface{}) {
+	_ = l.Output(calldepth, header("ERROR", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Errorf(format string, v ...interface{}) {
+	_ = l.Output(calldepth, header("ERROR", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Warning(v ...interface{}) {
+	_ = l.Output(calldepth, header("WARN", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Warningf(format string, v ...interface{}) {
+	_ = l.Output(calldepth, header("WARN", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Fatal(v ...interface{}) {
+	_ = l.Output(calldepth, header("FATAL", fmt.Sprint(v...)))
+	os.Exit(1)
+}
+
+func (l *DefaultLogger) Fatalf(format string, v ...interface{}) {
+	_ = l.Output(calldepth, header("FATAL", fmt.Sprintf(format, v...)))
+	os.Exit(1)
+}
+
+func (l *DefaultLogger) Panic(v ...interface{}) {
+	l.Logger.Panic(v...)
+}
+
+func (l *DefaultLogger) Panicf(format string, v ...interface{}) {
+	l.Logger.Panicf(format, v...)
+}
+
+func header(lvl, msg string) string {
+	return fmt.Sprintf("%s: %s", lvl, msg)
+}
diff --git a/vendor/go.etcd.io/bbolt/mlock_unix.go b/vendor/go.etcd.io/bbolt/mlock_unix.go
new file mode 100644
index 0000000..9a0fd33
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/mlock_unix.go
@@ -0,0 +1,36 @@
+//go:build !windows
+
+package bbolt
+
+import "golang.org/x/sys/unix"
+
+// mlock locks memory of db file
+func mlock(db *DB, fileSize int) error {
+	sizeToLock := fileSize
+	if sizeToLock > db.datasz {
+		// Can't lock more than mmaped slice
+		sizeToLock = db.datasz
+	}
+	if err := unix.Mlock(db.dataref[:sizeToLock]); err != nil {
+		return err
+	}
+	return nil
+}
+
+// munlock unlocks memory of db file
+func munlock(db *DB, fileSize int) error {
+	if db.dataref == nil {
+		return nil
+	}
+
+	sizeToUnlock := fileSize
+	if sizeToUnlock > db.datasz {
+		// Can't unlock more than mmaped slice
+		sizeToUnlock = db.datasz
+	}
+
+	if err := unix.Munlock(db.dataref[:sizeToUnlock]); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/vendor/go.etcd.io/bbolt/mlock_windows.go b/vendor/go.etcd.io/bbolt/mlock_windows.go
new file mode 100644
index 0000000..00b0fb4
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/mlock_windows.go
@@ -0,0 +1,11 @@
+package bbolt
+
+// mlock locks memory of db file
+func mlock(_ *DB, _ int) error {
+	panic("mlock is supported only on UNIX systems")
+}
+
+// munlock unlocks memory of db file
+func munlock(_ *DB, _ int) error {
+	panic("munlock is supported only on UNIX systems")
+}
diff --git a/vendor/go.etcd.io/bbolt/node.go b/vendor/go.etcd.io/bbolt/node.go
new file mode 100644
index 0000000..022b100
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/node.go
@@ -0,0 +1,538 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// node represents an in-memory, deserialized page.
+type node struct {
+	bucket     *Bucket
+	isLeaf     bool
+	unbalanced bool
+	spilled    bool
+	key        []byte
+	pgid       common.Pgid
+	parent     *node
+	children   nodes
+	inodes     common.Inodes
+}
+
+// root returns the top-level node this node is attached to.
+func (n *node) root() *node {
+	if n.parent == nil {
+		return n
+	}
+	return n.parent.root()
+}
+
+// minKeys returns the minimum number of inodes this node should have.
+func (n *node) minKeys() int {
+	if n.isLeaf {
+		return 1
+	}
+	return 2
+}
+
+// size returns the size of the node after serialization.
+func (n *node) size() int {
+	sz, elsz := common.PageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + uintptr(len(item.Key())) + uintptr(len(item.Value()))
+	}
+	return int(sz)
+}
+
+// sizeLessThan returns true if the node is less than a given size.
+// This is an optimization to avoid calculating a large node when we only need
+// to know if it fits inside a certain page size.
+func (n *node) sizeLessThan(v uintptr) bool {
+	sz, elsz := common.PageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + uintptr(len(item.Key())) + uintptr(len(item.Value()))
+		if sz >= v {
+			return false
+		}
+	}
+	return true
+}
+
+// pageElementSize returns the size of each page element based on the type of node.
+func (n *node) pageElementSize() uintptr {
+	if n.isLeaf {
+		return common.LeafPageElementSize
+	}
+	return common.BranchPageElementSize
+}
+
+// childAt returns the child node at a given index.
+func (n *node) childAt(index int) *node {
+	if n.isLeaf {
+		panic(fmt.Sprintf("invalid childAt(%d) on a leaf node", index))
+	}
+	return n.bucket.node(n.inodes[index].Pgid(), n)
+}
+
+// childIndex returns the index of a given child node.
+func (n *node) childIndex(child *node) int {
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].Key(), child.key) != -1 })
+	return index
+}
+
+// numChildren returns the number of children.
+func (n *node) numChildren() int {
+	return len(n.inodes)
+}
+
+// nextSibling returns the next node with the same parent.
+func (n *node) nextSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index >= n.parent.numChildren()-1 {
+		return nil
+	}
+	return n.parent.childAt(index + 1)
+}
+
+// prevSibling returns the previous node with the same parent.
+func (n *node) prevSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index == 0 {
+		return nil
+	}
+	return n.parent.childAt(index - 1)
+}
+
+// put inserts a key/value.
+func (n *node) put(oldKey, newKey, value []byte, pgId common.Pgid, flags uint32) {
+	if pgId >= n.bucket.tx.meta.Pgid() {
+		panic(fmt.Sprintf("pgId (%d) above high water mark (%d)", pgId, n.bucket.tx.meta.Pgid()))
+	} else if len(oldKey) <= 0 {
+		panic("put: zero-length old key")
+	} else if len(newKey) <= 0 {
+		panic("put: zero-length new key")
+	}
+
+	// Find insertion index.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].Key(), oldKey) != -1 })
+
+	// Add capacity and shift nodes if we don't have an exact match and need to insert.
+	exact := len(n.inodes) > 0 && index < len(n.inodes) && bytes.Equal(n.inodes[index].Key(), oldKey)
+	if !exact {
+		n.inodes = append(n.inodes, common.Inode{})
+		copy(n.inodes[index+1:], n.inodes[index:])
+	}
+
+	inode := &n.inodes[index]
+	inode.SetFlags(flags)
+	inode.SetKey(newKey)
+	inode.SetValue(value)
+	inode.SetPgid(pgId)
+	common.Assert(len(inode.Key()) > 0, "put: zero-length inode key")
+}
+
+// del removes a key from the node.
+func (n *node) del(key []byte) {
+	// Find index of key.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].Key(), key) != -1 })
+
+	// Exit if the key isn't found.
+	if index >= len(n.inodes) || !bytes.Equal(n.inodes[index].Key(), key) {
+		return
+	}
+
+	// Delete inode from the node.
+	n.inodes = append(n.inodes[:index], n.inodes[index+1:]...)
+
+	// Mark the node as needing rebalancing.
+	n.unbalanced = true
+}
+
+// read initializes the node from a page.
+func (n *node) read(p *common.Page) {
+	n.pgid = p.Id()
+	n.isLeaf = p.IsLeafPage()
+	n.inodes = common.ReadInodeFromPage(p)
+
+	// Save first key, so we can find the node in the parent when we spill.
+	if len(n.inodes) > 0 {
+		n.key = n.inodes[0].Key()
+		common.Assert(len(n.key) > 0, "read: zero-length node key")
+	} else {
+		n.key = nil
+	}
+}
+
+// write writes the items onto one or more pages.
+// The page should have p.id (might be 0 for meta or bucket-inline page) and p.overflow set
+// and the rest should be zeroed.
+func (n *node) write(p *common.Page) {
+	common.Assert(p.Count() == 0 && p.Flags() == 0, "node cannot be written into a not empty page")
+
+	// Initialize page.
+	if n.isLeaf {
+		p.SetFlags(common.LeafPageFlag)
+	} else {
+		p.SetFlags(common.BranchPageFlag)
+	}
+
+	if len(n.inodes) >= 0xFFFF {
+		panic(fmt.Sprintf("inode overflow: %d (pgid=%d)", len(n.inodes), p.Id()))
+	}
+	p.SetCount(uint16(len(n.inodes)))
+
+	// Stop here if there are no items to write.
+	if p.Count() == 0 {
+		return
+	}
+
+	common.WriteInodeToPage(n.inodes, p)
+
+	// DEBUG ONLY: n.dump()
+}
+
+// split breaks up a node into multiple smaller nodes, if appropriate.
+// This should only be called from the spill() function.
+func (n *node) split(pageSize uintptr) []*node {
+	var nodes []*node
+
+	node := n
+	for {
+		// Split node into two.
+		a, b := node.splitTwo(pageSize)
+		nodes = append(nodes, a)
+
+		// If we can't split then exit the loop.
+		if b == nil {
+			break
+		}
+
+		// Set node to b so it gets split on the next iteration.
+		node = b
+	}
+
+	return nodes
+}
+
+// splitTwo breaks up a node into two smaller nodes, if appropriate.
+// This should only be called from the split() function.
+func (n *node) splitTwo(pageSize uintptr) (*node, *node) {
+	// Ignore the split if the page doesn't have at least enough nodes for
+	// two pages or if the nodes can fit in a single page.
+	if len(n.inodes) <= (common.MinKeysPerPage*2) || n.sizeLessThan(pageSize) {
+		return n, nil
+	}
+
+	// Determine the threshold before starting a new node.
+	var fillPercent = n.bucket.FillPercent
+	if fillPercent < minFillPercent {
+		fillPercent = minFillPercent
+	} else if fillPercent > maxFillPercent {
+		fillPercent = maxFillPercent
+	}
+	threshold := int(float64(pageSize) * fillPercent)
+
+	// Determine split position and sizes of the two pages.
+	splitIndex, _ := n.splitIndex(threshold)
+
+	// Split node into two separate nodes.
+	// If there's no parent then we'll need to create one.
+	if n.parent == nil {
+		n.parent = &node{bucket: n.bucket, children: []*node{n}}
+	}
+
+	// Create a new node and add it to the parent.
+	next := &node{bucket: n.bucket, isLeaf: n.isLeaf, parent: n.parent}
+	n.parent.children = append(n.parent.children, next)
+
+	// Split inodes across two nodes.
+	next.inodes = n.inodes[splitIndex:]
+	n.inodes = n.inodes[:splitIndex]
+
+	// Update the statistics.
+	n.bucket.tx.stats.IncSplit(1)
+
+	return n, next
+}
+
+// splitIndex finds the position where a page will fill a given threshold.
+// It returns the index as well as the size of the first page.
+// This is only be called from split().
+func (n *node) splitIndex(threshold int) (index, sz uintptr) {
+	sz = common.PageHeaderSize
+
+	// Loop until we only have the minimum number of keys required for the second page.
+	for i := 0; i < len(n.inodes)-common.MinKeysPerPage; i++ {
+		index = uintptr(i)
+		inode := n.inodes[i]
+		elsize := n.pageElementSize() + uintptr(len(inode.Key())) + uintptr(len(inode.Value()))
+
+		// If we have at least the minimum number of keys and adding another
+		// node would put us over the threshold then exit and return.
+		if index >= common.MinKeysPerPage && sz+elsize > uintptr(threshold) {
+			break
+		}
+
+		// Add the element size to the total size.
+		sz += elsize
+	}
+
+	return
+}
+
+// spill writes the nodes to dirty pages and splits nodes as it goes.
+// Returns an error if dirty pages cannot be allocated.
+func (n *node) spill() error {
+	var tx = n.bucket.tx
+	if n.spilled {
+		return nil
+	}
+
+	// Spill child nodes first. Child nodes can materialize sibling nodes in
+	// the case of split-merge so we cannot use a range loop. We have to check
+	// the children size on every loop iteration.
+	sort.Sort(n.children)
+	for i := 0; i < len(n.children); i++ {
+		if err := n.children[i].spill(); err != nil {
+			return err
+		}
+	}
+
+	// We no longer need the child list because it's only used for spill tracking.
+	n.children = nil
+
+	// Split nodes into appropriate sizes. The first node will always be n.
+	var nodes = n.split(uintptr(tx.db.pageSize))
+	for _, node := range nodes {
+		// Add node's page to the freelist if it's not new.
+		if node.pgid > 0 {
+			tx.db.freelist.Free(tx.meta.Txid(), tx.page(node.pgid))
+			node.pgid = 0
+		}
+
+		// Allocate contiguous space for the node.
+		p, err := tx.allocate((node.size() + tx.db.pageSize - 1) / tx.db.pageSize)
+		if err != nil {
+			return err
+		}
+
+		// Write the node.
+		if p.Id() >= tx.meta.Pgid() {
+			panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", p.Id(), tx.meta.Pgid()))
+		}
+		node.pgid = p.Id()
+		node.write(p)
+		node.spilled = true
+
+		// Insert into parent inodes.
+		if node.parent != nil {
+			var key = node.key
+			if key == nil {
+				key = node.inodes[0].Key()
+			}
+
+			node.parent.put(key, node.inodes[0].Key(), nil, node.pgid, 0)
+			node.key = node.inodes[0].Key()
+			common.Assert(len(node.key) > 0, "spill: zero-length node key")
+		}
+
+		// Update the statistics.
+		tx.stats.IncSpill(1)
+	}
+
+	// If the root node split and created a new root then we need to spill that
+	// as well. We'll clear out the children to make sure it doesn't try to respill.
+	if n.parent != nil && n.parent.pgid == 0 {
+		n.children = nil
+		return n.parent.spill()
+	}
+
+	return nil
+}
+
+// rebalance attempts to combine the node with sibling nodes if the node fill
+// size is below a threshold or if there are not enough keys.
+func (n *node) rebalance() {
+	if !n.unbalanced {
+		return
+	}
+	n.unbalanced = false
+
+	// Update statistics.
+	n.bucket.tx.stats.IncRebalance(1)
+
+	// Ignore if node is above threshold (25% when FillPercent is set to DefaultFillPercent) and has enough keys.
+	var threshold = int(float64(n.bucket.tx.db.pageSize)*n.bucket.FillPercent) / 2
+	if n.size() > threshold && len(n.inodes) > n.minKeys() {
+		return
+	}
+
+	// Root node has special handling.
+	if n.parent == nil {
+		// If root node is a branch and only has one node then collapse it.
+		if !n.isLeaf && len(n.inodes) == 1 {
+			// Move root's child up.
+			child := n.bucket.node(n.inodes[0].Pgid(), n)
+			n.isLeaf = child.isLeaf
+			n.inodes = child.inodes[:]
+			n.children = child.children
+
+			// Reparent all child nodes being moved.
+			for _, inode := range n.inodes {
+				if child, ok := n.bucket.nodes[inode.Pgid()]; ok {
+					child.parent = n
+				}
+			}
+
+			// Remove old child.
+			child.parent = nil
+			delete(n.bucket.nodes, child.pgid)
+			child.free()
+		}
+
+		return
+	}
+
+	// If node has no keys then just remove it.
+	if n.numChildren() == 0 {
+		n.parent.del(n.key)
+		n.parent.removeChild(n)
+		delete(n.bucket.nodes, n.pgid)
+		n.free()
+		n.parent.rebalance()
+		return
+	}
+
+	common.Assert(n.parent.numChildren() > 1, "parent must have at least 2 children")
+
+	// Merge with right sibling if idx == 0, otherwise left sibling.
+	var leftNode, rightNode *node
+	var useNextSibling = n.parent.childIndex(n) == 0
+	if useNextSibling {
+		leftNode = n
+		rightNode = n.nextSibling()
+	} else {
+		leftNode = n.prevSibling()
+		rightNode = n
+	}
+
+	// If both nodes are too small then merge them.
+	// Reparent all child nodes being moved.
+	for _, inode := range rightNode.inodes {
+		if child, ok := n.bucket.nodes[inode.Pgid()]; ok {
+			child.parent.removeChild(child)
+			child.parent = leftNode
+			child.parent.children = append(child.parent.children, child)
+		}
+	}
+
+	// Copy over inodes from right node to left node and remove right node.
+	leftNode.inodes = append(leftNode.inodes, rightNode.inodes...)
+	n.parent.del(rightNode.key)
+	n.parent.removeChild(rightNode)
+	delete(n.bucket.nodes, rightNode.pgid)
+	rightNode.free()
+
+	// Either this node or the sibling node was deleted from the parent so rebalance it.
+	n.parent.rebalance()
+}
+
+// removes a node from the list of in-memory children.
+// This does not affect the inodes.
+func (n *node) removeChild(target *node) {
+	for i, child := range n.children {
+		if child == target {
+			n.children = append(n.children[:i], n.children[i+1:]...)
+			return
+		}
+	}
+}
+
+// dereference causes the node to copy all its inode key/value references to heap memory.
+// This is required when the mmap is reallocated so inodes are not pointing to stale data.
+func (n *node) dereference() {
+	if n.key != nil {
+		key := make([]byte, len(n.key))
+		copy(key, n.key)
+		n.key = key
+		common.Assert(n.pgid == 0 || len(n.key) > 0, "dereference: zero-length node key on existing node")
+	}
+
+	for i := range n.inodes {
+		inode := &n.inodes[i]
+
+		key := make([]byte, len(inode.Key()))
+		copy(key, inode.Key())
+		inode.SetKey(key)
+		common.Assert(len(inode.Key()) > 0, "dereference: zero-length inode key")
+
+		value := make([]byte, len(inode.Value()))
+		copy(value, inode.Value())
+		inode.SetValue(value)
+	}
+
+	// Recursively dereference children.
+	for _, child := range n.children {
+		child.dereference()
+	}
+
+	// Update statistics.
+	n.bucket.tx.stats.IncNodeDeref(1)
+}
+
+// free adds the node's underlying page to the freelist.
+func (n *node) free() {
+	if n.pgid != 0 {
+		n.bucket.tx.db.freelist.Free(n.bucket.tx.meta.Txid(), n.bucket.tx.page(n.pgid))
+		n.pgid = 0
+	}
+}
+
+// dump writes the contents of the node to STDERR for debugging purposes.
+/*
+func (n *node) dump() {
+	// Write node header.
+	var typ = "branch"
+	if n.isLeaf {
+		typ = "leaf"
+	}
+	warnf("[NODE %d {type=%s count=%d}]", n.pgid, typ, len(n.inodes))
+
+	// Write out abbreviated version of each item.
+	for _, item := range n.inodes {
+		if n.isLeaf {
+			if item.flags&bucketLeafFlag != 0 {
+				bucket := (*bucket)(unsafe.Pointer(&item.value[0]))
+				warnf("+L %08x -> (bucket root=%d)", trunc(item.key, 4), bucket.root)
+			} else {
+				warnf("+L %08x -> %08x", trunc(item.key, 4), trunc(item.value, 4))
+			}
+		} else {
+			warnf("+B %08x -> pgid=%d", trunc(item.key, 4), item.pgid)
+		}
+	}
+	warn("")
+}
+*/
+
+func compareKeys(left, right []byte) int {
+	return bytes.Compare(left, right)
+}
+
+type nodes []*node
+
+func (s nodes) Len() int      { return len(s) }
+func (s nodes) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+func (s nodes) Less(i, j int) bool {
+	return bytes.Compare(s[i].inodes[0].Key(), s[j].inodes[0].Key()) == -1
+}
diff --git a/vendor/go.etcd.io/bbolt/tx.go b/vendor/go.etcd.io/bbolt/tx.go
new file mode 100644
index 0000000..1669fb1
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/tx.go
@@ -0,0 +1,901 @@
+package bbolt
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"sort"
+	"strings"
+	"sync/atomic"
+	"time"
+	"unsafe"
+
+	berrors "go.etcd.io/bbolt/errors"
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// Tx represents a read-only or read/write transaction on the database.
+// Read-only transactions can be used for retrieving values for keys and creating cursors.
+// Read/write transactions can create and remove buckets and create and remove keys.
+//
+// IMPORTANT: You must commit or rollback transactions when you are done with
+// them. Pages can not be reclaimed by the writer until no more transactions
+// are using them. A long running read transaction can cause the database to
+// quickly grow.
+type Tx struct {
+	writable       bool
+	managed        bool
+	db             *DB
+	meta           *common.Meta
+	root           Bucket
+	pages          map[common.Pgid]*common.Page
+	stats          TxStats
+	commitHandlers []func()
+
+	// WriteFlag specifies the flag for write-related methods like WriteTo().
+	// Tx opens the database file with the specified flag to copy the data.
+	//
+	// By default, the flag is unset, which works well for mostly in-memory
+	// workloads. For databases that are much larger than available RAM,
+	// set the flag to syscall.O_DIRECT to avoid trashing the page cache.
+	WriteFlag int
+}
+
+// init initializes the transaction.
+func (tx *Tx) init(db *DB) {
+	tx.db = db
+	tx.pages = nil
+
+	// Copy the meta page since it can be changed by the writer.
+	tx.meta = &common.Meta{}
+	db.meta().Copy(tx.meta)
+
+	// Copy over the root bucket.
+	tx.root = newBucket(tx)
+	tx.root.InBucket = &common.InBucket{}
+	*tx.root.InBucket = *(tx.meta.RootBucket())
+
+	// Increment the transaction id and add a page cache for writable transactions.
+	if tx.writable {
+		tx.pages = make(map[common.Pgid]*common.Page)
+		tx.meta.IncTxid()
+	}
+}
+
+// ID returns the transaction id.
+func (tx *Tx) ID() int {
+	if tx == nil || tx.meta == nil {
+		return -1
+	}
+	return int(tx.meta.Txid())
+}
+
+// DB returns a reference to the database that created the transaction.
+func (tx *Tx) DB() *DB {
+	return tx.db
+}
+
+// Size returns current database size in bytes as seen by this transaction.
+func (tx *Tx) Size() int64 {
+	return int64(tx.meta.Pgid()) * int64(tx.db.pageSize)
+}
+
+// Writable returns whether the transaction can perform write operations.
+func (tx *Tx) Writable() bool {
+	return tx.writable
+}
+
+// Cursor creates a cursor associated with the root bucket.
+// All items in the cursor will return a nil value because all root bucket keys point to buckets.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (tx *Tx) Cursor() *Cursor {
+	return tx.root.Cursor()
+}
+
+// Stats retrieves a copy of the current transaction statistics.
+func (tx *Tx) Stats() TxStats {
+	return tx.stats
+}
+
+// Inspect returns the structure of the database.
+func (tx *Tx) Inspect() BucketStructure {
+	return tx.root.Inspect()
+}
+
+// Bucket retrieves a bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) Bucket(name []byte) *Bucket {
+	return tx.root.Bucket(name)
+}
+
+// CreateBucket creates a new bucket.
+// Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucket(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucket(name)
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucketIfNotExists(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucketIfNotExists(name)
+}
+
+// DeleteBucket deletes a bucket.
+// Returns an error if the bucket cannot be found or if the key represents a non-bucket value.
+func (tx *Tx) DeleteBucket(name []byte) error {
+	return tx.root.DeleteBucket(name)
+}
+
+// MoveBucket moves a sub-bucket from the source bucket to the destination bucket.
+// Returns an error if
+//  1. the sub-bucket cannot be found in the source bucket;
+//  2. or the key already exists in the destination bucket;
+//  3. the key represents a non-bucket value.
+//
+// If src is nil, it means moving a top level bucket into the target bucket.
+// If dst is nil, it means converting the child bucket into a top level bucket.
+func (tx *Tx) MoveBucket(child []byte, src *Bucket, dst *Bucket) error {
+	if src == nil {
+		src = &tx.root
+	}
+	if dst == nil {
+		dst = &tx.root
+	}
+	return src.MoveBucket(child, dst)
+}
+
+// ForEach executes a function for each bucket in the root.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller.
+func (tx *Tx) ForEach(fn func(name []byte, b *Bucket) error) error {
+	return tx.root.ForEach(func(k, v []byte) error {
+		return fn(k, tx.root.Bucket(k))
+	})
+}
+
+// OnCommit adds a handler function to be executed after the transaction successfully commits.
+func (tx *Tx) OnCommit(fn func()) {
+	tx.commitHandlers = append(tx.commitHandlers, fn)
+}
+
+// Commit writes all changes to disk, updates the meta page and closes the transaction.
+// Returns an error if a disk write error occurs, or if Commit is
+// called on a read-only transaction.
+func (tx *Tx) Commit() (err error) {
+	txId := tx.ID()
+	lg := tx.db.Logger()
+	if lg != discardLogger {
+		lg.Debugf("Committing transaction %d", txId)
+		defer func() {
+			if err != nil {
+				lg.Errorf("Committing transaction failed: %v", err)
+			} else {
+				lg.Debugf("Committing transaction %d successfully", txId)
+			}
+		}()
+	}
+
+	common.Assert(!tx.managed, "managed tx commit not allowed")
+	if tx.db == nil {
+		return berrors.ErrTxClosed
+	} else if !tx.writable {
+		return berrors.ErrTxNotWritable
+	}
+
+	// TODO(benbjohnson): Use vectorized I/O to write out dirty pages.
+
+	// Rebalance nodes which have had deletions.
+	var startTime = time.Now()
+	tx.root.rebalance()
+	if tx.stats.GetRebalance() > 0 {
+		tx.stats.IncRebalanceTime(time.Since(startTime))
+	}
+
+	opgid := tx.meta.Pgid()
+
+	// spill data onto dirty pages.
+	startTime = time.Now()
+	if err = tx.root.spill(); err != nil {
+		lg.Errorf("spilling data onto dirty pages failed: %v", err)
+		tx.rollback()
+		return err
+	}
+	tx.stats.IncSpillTime(time.Since(startTime))
+
+	// Free the old root bucket.
+	tx.meta.RootBucket().SetRootPage(tx.root.RootPage())
+
+	// Free the old freelist because commit writes out a fresh freelist.
+	if tx.meta.Freelist() != common.PgidNoFreelist {
+		tx.db.freelist.Free(tx.meta.Txid(), tx.db.page(tx.meta.Freelist()))
+	}
+
+	if !tx.db.NoFreelistSync {
+		err = tx.commitFreelist()
+		if err != nil {
+			lg.Errorf("committing freelist failed: %v", err)
+			return err
+		}
+	} else {
+		tx.meta.SetFreelist(common.PgidNoFreelist)
+	}
+
+	// If the high water mark has moved up then attempt to grow the database.
+	if tx.meta.Pgid() > opgid {
+		_ = errors.New("")
+		// gofail: var lackOfDiskSpace string
+		// tx.rollback()
+		// return errors.New(lackOfDiskSpace)
+		if err = tx.db.grow(int(tx.meta.Pgid()+1) * tx.db.pageSize); err != nil {
+			lg.Errorf("growing db size failed, pgid: %d, pagesize: %d, error: %v", tx.meta.Pgid(), tx.db.pageSize, err)
+			tx.rollback()
+			return err
+		}
+	}
+
+	// Write dirty pages to disk.
+	startTime = time.Now()
+	if err = tx.write(); err != nil {
+		lg.Errorf("writing data failed: %v", err)
+		tx.rollback()
+		return err
+	}
+
+	// If strict mode is enabled then perform a consistency check.
+	if tx.db.StrictMode {
+		ch := tx.Check()
+		var errs []string
+		for {
+			chkErr, ok := <-ch
+			if !ok {
+				break
+			}
+			errs = append(errs, chkErr.Error())
+		}
+		if len(errs) > 0 {
+			panic("check fail: " + strings.Join(errs, "\n"))
+		}
+	}
+
+	// Write meta to disk.
+	if err = tx.writeMeta(); err != nil {
+		lg.Errorf("writeMeta failed: %v", err)
+		tx.rollback()
+		return err
+	}
+	tx.stats.IncWriteTime(time.Since(startTime))
+
+	// Finalize the transaction.
+	tx.close()
+
+	// Execute commit handlers now that the locks have been removed.
+	for _, fn := range tx.commitHandlers {
+		fn()
+	}
+
+	return nil
+}
+
+func (tx *Tx) commitFreelist() error {
+	// Allocate new pages for the new free list. This will overestimate
+	// the size of the freelist but not underestimate the size (which would be bad).
+	p, err := tx.allocate((tx.db.freelist.EstimatedWritePageSize() / tx.db.pageSize) + 1)
+	if err != nil {
+		tx.rollback()
+		return err
+	}
+
+	tx.db.freelist.Write(p)
+	tx.meta.SetFreelist(p.Id())
+
+	return nil
+}
+
+// Rollback closes the transaction and ignores all previous updates. Read-only
+// transactions must be rolled back and not committed.
+func (tx *Tx) Rollback() error {
+	common.Assert(!tx.managed, "managed tx rollback not allowed")
+	if tx.db == nil {
+		return berrors.ErrTxClosed
+	}
+	tx.nonPhysicalRollback()
+	return nil
+}
+
+// nonPhysicalRollback is called when user calls Rollback directly, in this case we do not need to reload the free pages from disk.
+func (tx *Tx) nonPhysicalRollback() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		tx.db.freelist.Rollback(tx.meta.Txid())
+	}
+	tx.close()
+}
+
+// rollback needs to reload the free pages from disk in case some system error happens like fsync error.
+func (tx *Tx) rollback() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		tx.db.freelist.Rollback(tx.meta.Txid())
+		// When mmap fails, the `data`, `dataref` and `datasz` may be reset to
+		// zero values, and there is no way to reload free page IDs in this case.
+		if tx.db.data != nil {
+			if !tx.db.hasSyncedFreelist() {
+				// Reconstruct free page list by scanning the DB to get the whole free page list.
+				// Note: scanning the whole db is heavy if your db size is large in NoSyncFreeList mode.
+				tx.db.freelist.NoSyncReload(tx.db.freepages())
+			} else {
+				// Read free page list from freelist page.
+				tx.db.freelist.Reload(tx.db.page(tx.db.meta().Freelist()))
+			}
+		}
+	}
+	tx.close()
+}
+
+func (tx *Tx) close() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		// Grab freelist stats.
+		var freelistFreeN = tx.db.freelist.FreeCount()
+		var freelistPendingN = tx.db.freelist.PendingCount()
+		var freelistAlloc = tx.db.freelist.EstimatedWritePageSize()
+
+		// Remove transaction ref & writer lock.
+		tx.db.rwtx = nil
+		tx.db.rwlock.Unlock()
+
+		// Merge statistics.
+		tx.db.statlock.Lock()
+		tx.db.stats.FreePageN = freelistFreeN
+		tx.db.stats.PendingPageN = freelistPendingN
+		tx.db.stats.FreeAlloc = (freelistFreeN + freelistPendingN) * tx.db.pageSize
+		tx.db.stats.FreelistInuse = freelistAlloc
+		tx.db.stats.TxStats.add(&tx.stats)
+		tx.db.statlock.Unlock()
+	} else {
+		tx.db.removeTx(tx)
+	}
+
+	// Clear all references.
+	tx.db = nil
+	tx.meta = nil
+	tx.root = Bucket{tx: tx}
+	tx.pages = nil
+}
+
+// Copy writes the entire database to a writer.
+// This function exists for backwards compatibility.
+//
+// Deprecated: Use WriteTo() instead.
+func (tx *Tx) Copy(w io.Writer) error {
+	_, err := tx.WriteTo(w)
+	return err
+}
+
+// WriteTo writes the entire database to a writer.
+// If err == nil then exactly tx.Size() bytes will be written into the writer.
+func (tx *Tx) WriteTo(w io.Writer) (n int64, err error) {
+	var f *os.File
+	// There is a risk that between the time a read-only transaction
+	// is created and the time the file is actually opened, the
+	// underlying db file at tx.db.path may have been replaced
+	// (e.g. via rename). In that case, opening the file again would
+	// unexpectedly point to a different file, rather than the one
+	// the transaction was based on.
+	//
+	// To overcome this, we reuse the already opened file handle when
+	// WritFlag not set. When the WriteFlag is set, we reopen the file
+	// but verify that it still refers to the same underlying file
+	// (by device and inode). If it does not, we fall back to
+	// reusing the existing already opened file handle.
+	if tx.WriteFlag != 0 {
+		// Attempt to open reader with WriteFlag
+		f, err = tx.db.openFile(tx.db.path, os.O_RDONLY|tx.WriteFlag, 0)
+		if err != nil {
+			return 0, err
+		}
+
+		if ok, err := sameFile(tx.db.file, f); !ok {
+			lg := tx.db.Logger()
+			if cerr := f.Close(); cerr != nil {
+				lg.Errorf("failed to close the file (%s): %v", tx.db.path, cerr)
+			}
+			lg.Warningf("The underlying file has changed, so reuse the already opened file (%s): %v", tx.db.path, err)
+			f = tx.db.file
+		} else {
+			defer func() {
+				if cerr := f.Close(); err == nil {
+					err = cerr
+				}
+			}()
+		}
+	} else {
+		f = tx.db.file
+	}
+
+	// Generate a meta page. We use the same page data for both meta pages.
+	buf := make([]byte, tx.db.pageSize)
+	page := (*common.Page)(unsafe.Pointer(&buf[0]))
+	page.SetFlags(common.MetaPageFlag)
+	*page.Meta() = *tx.meta
+
+	// Write meta 0.
+	page.SetId(0)
+	page.Meta().SetChecksum(page.Meta().Sum64())
+	nn, err := w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 0 copy: %s", err)
+	}
+
+	// Write meta 1 with a lower transaction id.
+	page.SetId(1)
+	page.Meta().DecTxid()
+	page.Meta().SetChecksum(page.Meta().Sum64())
+	nn, err = w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 1 copy: %s", err)
+	}
+
+	// Copy data pages using a SectionReader to avoid affecting f's offset.
+	dataOffset := int64(tx.db.pageSize * 2)
+	dataSize := tx.Size() - dataOffset
+	sr := io.NewSectionReader(f, dataOffset, dataSize)
+
+	// Copy data pages.
+	wn, err := io.CopyN(w, sr, dataSize)
+	n += wn
+	if err != nil {
+		return n, err
+	}
+
+	return n, nil
+}
+
+func sameFile(f1, f2 *os.File) (bool, error) {
+	fi1, err := f1.Stat()
+	if err != nil {
+		return false, fmt.Errorf("failed to get fileInfo of the first file (%s): %w", f1.Name(), err)
+	}
+	fi2, err := f2.Stat()
+	if err != nil {
+		return false, fmt.Errorf("failed to get fileInfo of the second file (%s): %w", f2.Name(), err)
+	}
+
+	return os.SameFile(fi1, fi2), nil
+}
+
+// CopyFile copies the entire database to file at the given path.
+// A reader transaction is maintained during the copy so it is safe to continue
+// using the database while a copy is in progress.
+func (tx *Tx) CopyFile(path string, mode os.FileMode) error {
+	f, err := tx.db.openFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
+	if err != nil {
+		return err
+	}
+
+	_, err = tx.WriteTo(f)
+	if err != nil {
+		_ = f.Close()
+		return err
+	}
+	return f.Close()
+}
+
+// allocate returns a contiguous block of memory starting at a given page.
+func (tx *Tx) allocate(count int) (*common.Page, error) {
+	lg := tx.db.Logger()
+	p, err := tx.db.allocate(tx.meta.Txid(), count)
+	if err != nil {
+		lg.Errorf("allocating failed, txid: %d, count: %d, error: %v", tx.meta.Txid(), count, err)
+		return nil, err
+	}
+
+	// Save to our page cache.
+	tx.pages[p.Id()] = p
+
+	// Update statistics.
+	tx.stats.IncPageCount(int64(count))
+	tx.stats.IncPageAlloc(int64(count * tx.db.pageSize))
+
+	return p, nil
+}
+
+// write writes any dirty pages to disk.
+func (tx *Tx) write() error {
+	// Sort pages by id.
+	lg := tx.db.Logger()
+	pages := make(common.Pages, 0, len(tx.pages))
+	for _, p := range tx.pages {
+		pages = append(pages, p)
+	}
+	// Clear out page cache early.
+	tx.pages = make(map[common.Pgid]*common.Page)
+	sort.Sort(pages)
+
+	// Write pages to disk in order.
+	for _, p := range pages {
+		rem := (uint64(p.Overflow()) + 1) * uint64(tx.db.pageSize)
+		offset := int64(p.Id()) * int64(tx.db.pageSize)
+		var written uintptr
+
+		// Write out page in "max allocation" sized chunks.
+		for {
+			sz := rem
+			if sz > common.MaxAllocSize-1 {
+				sz = common.MaxAllocSize - 1
+			}
+			buf := common.UnsafeByteSlice(unsafe.Pointer(p), written, 0, int(sz))
+
+			if _, err := tx.db.ops.writeAt(buf, offset); err != nil {
+				lg.Errorf("writeAt failed, offset: %d: %w", offset, err)
+				return err
+			}
+
+			// Update statistics.
+			tx.stats.IncWrite(1)
+
+			// Exit inner for loop if we've written all the chunks.
+			rem -= sz
+			if rem == 0 {
+				break
+			}
+
+			// Otherwise move offset forward and move pointer to next chunk.
+			offset += int64(sz)
+			written += uintptr(sz)
+		}
+	}
+
+	// Ignore file sync if flag is set on DB.
+	if !tx.db.NoSync || common.IgnoreNoSync {
+		// gofail: var beforeSyncDataPages struct{}
+		if err := fdatasync(tx.db); err != nil {
+			lg.Errorf("[GOOS: %s, GOARCH: %s] fdatasync failed: %w", runtime.GOOS, runtime.GOARCH, err)
+			return err
+		}
+	}
+
+	// Put small pages back to page pool.
+	for _, p := range pages {
+		// Ignore page sizes over 1 page.
+		// These are allocated using make() instead of the page pool.
+		if int(p.Overflow()) != 0 {
+			continue
+		}
+
+		buf := common.UnsafeByteSlice(unsafe.Pointer(p), 0, 0, tx.db.pageSize)
+
+		// See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1
+		for i := range buf {
+			buf[i] = 0
+		}
+		tx.db.pagePool.Put(buf) //nolint:staticcheck
+	}
+
+	return nil
+}
+
+// writeMeta writes the meta to the disk.
+func (tx *Tx) writeMeta() error {
+	// gofail: var beforeWriteMetaError string
+	// return errors.New(beforeWriteMetaError)
+
+	// Create a temporary buffer for the meta page.
+	lg := tx.db.Logger()
+	buf := make([]byte, tx.db.pageSize)
+	p := tx.db.pageInBuffer(buf, 0)
+	tx.meta.Write(p)
+
+	// Write the meta page to file.
+	tx.db.metalock.Lock()
+	if _, err := tx.db.ops.writeAt(buf, int64(p.Id())*int64(tx.db.pageSize)); err != nil {
+		tx.db.metalock.Unlock()
+		lg.Errorf("writeAt failed, pgid: %d, pageSize: %d, error: %v", p.Id(), tx.db.pageSize, err)
+		return err
+	}
+	tx.db.metalock.Unlock()
+	if !tx.db.NoSync || common.IgnoreNoSync {
+		// gofail: var beforeSyncMetaPage struct{}
+		if err := fdatasync(tx.db); err != nil {
+			lg.Errorf("[GOOS: %s, GOARCH: %s] fdatasync failed: %w", runtime.GOOS, runtime.GOARCH, err)
+			return err
+		}
+	}
+
+	// Update statistics.
+	tx.stats.IncWrite(1)
+
+	return nil
+}
+
+// page returns a reference to the page with a given id.
+// If page has been written to then a temporary buffered page is returned.
+func (tx *Tx) page(id common.Pgid) *common.Page {
+	// Check the dirty pages first.
+	if tx.pages != nil {
+		if p, ok := tx.pages[id]; ok {
+			p.FastCheck(id)
+			return p
+		}
+	}
+
+	// Otherwise return directly from the mmap.
+	p := tx.db.page(id)
+	p.FastCheck(id)
+	return p
+}
+
+// forEachPage iterates over every page within a given page and executes a function.
+func (tx *Tx) forEachPage(pgidnum common.Pgid, fn func(*common.Page, int, []common.Pgid)) {
+	stack := make([]common.Pgid, 10)
+	stack[0] = pgidnum
+	tx.forEachPageInternal(stack[:1], fn)
+}
+
+func (tx *Tx) forEachPageInternal(pgidstack []common.Pgid, fn func(*common.Page, int, []common.Pgid)) {
+	p := tx.page(pgidstack[len(pgidstack)-1])
+
+	// Execute function.
+	fn(p, len(pgidstack)-1, pgidstack)
+
+	// Recursively loop over children.
+	if p.IsBranchPage() {
+		for i := 0; i < int(p.Count()); i++ {
+			elem := p.BranchPageElement(uint16(i))
+			tx.forEachPageInternal(append(pgidstack, elem.Pgid()), fn)
+		}
+	}
+}
+
+// Page returns page information for a given page number.
+// This is only safe for concurrent use when used by a writable transaction.
+func (tx *Tx) Page(id int) (*common.PageInfo, error) {
+	if tx.db == nil {
+		return nil, berrors.ErrTxClosed
+	} else if common.Pgid(id) >= tx.meta.Pgid() {
+		return nil, nil
+	}
+
+	if tx.db.freelist == nil {
+		return nil, berrors.ErrFreePagesNotLoaded
+	}
+
+	// Build the page info.
+	p := tx.db.page(common.Pgid(id))
+	info := &common.PageInfo{
+		ID:            id,
+		Count:         int(p.Count()),
+		OverflowCount: int(p.Overflow()),
+	}
+
+	// Determine the type (or if it's free).
+	if tx.db.freelist.Freed(common.Pgid(id)) {
+		info.Type = "free"
+	} else {
+		info.Type = p.Typ()
+	}
+
+	return info, nil
+}
+
+// TxStats represents statistics about the actions performed by the transaction.
+type TxStats struct {
+	// Page statistics.
+	//
+	// DEPRECATED: Use GetPageCount() or IncPageCount()
+	PageCount int64 // number of page allocations
+	// DEPRECATED: Use GetPageAlloc() or IncPageAlloc()
+	PageAlloc int64 // total bytes allocated
+
+	// Cursor statistics.
+	//
+	// DEPRECATED: Use GetCursorCount() or IncCursorCount()
+	CursorCount int64 // number of cursors created
+
+	// Node statistics
+	//
+	// DEPRECATED: Use GetNodeCount() or IncNodeCount()
+	NodeCount int64 // number of node allocations
+	// DEPRECATED: Use GetNodeDeref() or IncNodeDeref()
+	NodeDeref int64 // number of node dereferences
+
+	// Rebalance statistics.
+	//
+	// DEPRECATED: Use GetRebalance() or IncRebalance()
+	Rebalance int64 // number of node rebalances
+	// DEPRECATED: Use GetRebalanceTime() or IncRebalanceTime()
+	RebalanceTime time.Duration // total time spent rebalancing
+
+	// Split/Spill statistics.
+	//
+	// DEPRECATED: Use GetSplit() or IncSplit()
+	Split int64 // number of nodes split
+	// DEPRECATED: Use GetSpill() or IncSpill()
+	Spill int64 // number of nodes spilled
+	// DEPRECATED: Use GetSpillTime() or IncSpillTime()
+	SpillTime time.Duration // total time spent spilling
+
+	// Write statistics.
+	//
+	// DEPRECATED: Use GetWrite() or IncWrite()
+	Write int64 // number of writes performed
+	// DEPRECATED: Use GetWriteTime() or IncWriteTime()
+	WriteTime time.Duration // total time spent writing to disk
+}
+
+func (s *TxStats) add(other *TxStats) {
+	s.IncPageCount(other.GetPageCount())
+	s.IncPageAlloc(other.GetPageAlloc())
+	s.IncCursorCount(other.GetCursorCount())
+	s.IncNodeCount(other.GetNodeCount())
+	s.IncNodeDeref(other.GetNodeDeref())
+	s.IncRebalance(other.GetRebalance())
+	s.IncRebalanceTime(other.GetRebalanceTime())
+	s.IncSplit(other.GetSplit())
+	s.IncSpill(other.GetSpill())
+	s.IncSpillTime(other.GetSpillTime())
+	s.IncWrite(other.GetWrite())
+	s.IncWriteTime(other.GetWriteTime())
+}
+
+// Sub calculates and returns the difference between two sets of transaction stats.
+// This is useful when obtaining stats at two different points and time and
+// you need the performance counters that occurred within that time span.
+func (s *TxStats) Sub(other *TxStats) TxStats {
+	var diff TxStats
+	diff.PageCount = s.GetPageCount() - other.GetPageCount()
+	diff.PageAlloc = s.GetPageAlloc() - other.GetPageAlloc()
+	diff.CursorCount = s.GetCursorCount() - other.GetCursorCount()
+	diff.NodeCount = s.GetNodeCount() - other.GetNodeCount()
+	diff.NodeDeref = s.GetNodeDeref() - other.GetNodeDeref()
+	diff.Rebalance = s.GetRebalance() - other.GetRebalance()
+	diff.RebalanceTime = s.GetRebalanceTime() - other.GetRebalanceTime()
+	diff.Split = s.GetSplit() - other.GetSplit()
+	diff.Spill = s.GetSpill() - other.GetSpill()
+	diff.SpillTime = s.GetSpillTime() - other.GetSpillTime()
+	diff.Write = s.GetWrite() - other.GetWrite()
+	diff.WriteTime = s.GetWriteTime() - other.GetWriteTime()
+	return diff
+}
+
+// GetPageCount returns PageCount atomically.
+func (s *TxStats) GetPageCount() int64 {
+	return atomic.LoadInt64(&s.PageCount)
+}
+
+// IncPageCount increases PageCount atomically and returns the new value.
+func (s *TxStats) IncPageCount(delta int64) int64 {
+	return atomic.AddInt64(&s.PageCount, delta)
+}
+
+// GetPageAlloc returns PageAlloc atomically.
+func (s *TxStats) GetPageAlloc() int64 {
+	return atomic.LoadInt64(&s.PageAlloc)
+}
+
+// IncPageAlloc increases PageAlloc atomically and returns the new value.
+func (s *TxStats) IncPageAlloc(delta int64) int64 {
+	return atomic.AddInt64(&s.PageAlloc, delta)
+}
+
+// GetCursorCount returns CursorCount atomically.
+func (s *TxStats) GetCursorCount() int64 {
+	return atomic.LoadInt64(&s.CursorCount)
+}
+
+// IncCursorCount increases CursorCount atomically and return the new value.
+func (s *TxStats) IncCursorCount(delta int64) int64 {
+	return atomic.AddInt64(&s.CursorCount, delta)
+}
+
+// GetNodeCount returns NodeCount atomically.
+func (s *TxStats) GetNodeCount() int64 {
+	return atomic.LoadInt64(&s.NodeCount)
+}
+
+// IncNodeCount increases NodeCount atomically and returns the new value.
+func (s *TxStats) IncNodeCount(delta int64) int64 {
+	return atomic.AddInt64(&s.NodeCount, delta)
+}
+
+// GetNodeDeref returns NodeDeref atomically.
+func (s *TxStats) GetNodeDeref() int64 {
+	return atomic.LoadInt64(&s.NodeDeref)
+}
+
+// IncNodeDeref increases NodeDeref atomically and returns the new value.
+func (s *TxStats) IncNodeDeref(delta int64) int64 {
+	return atomic.AddInt64(&s.NodeDeref, delta)
+}
+
+// GetRebalance returns Rebalance atomically.
+func (s *TxStats) GetRebalance() int64 {
+	return atomic.LoadInt64(&s.Rebalance)
+}
+
+// IncRebalance increases Rebalance atomically and returns the new value.
+func (s *TxStats) IncRebalance(delta int64) int64 {
+	return atomic.AddInt64(&s.Rebalance, delta)
+}
+
+// GetRebalanceTime returns RebalanceTime atomically.
+func (s *TxStats) GetRebalanceTime() time.Duration {
+	return atomicLoadDuration(&s.RebalanceTime)
+}
+
+// IncRebalanceTime increases RebalanceTime atomically and returns the new value.
+func (s *TxStats) IncRebalanceTime(delta time.Duration) time.Duration {
+	return atomicAddDuration(&s.RebalanceTime, delta)
+}
+
+// GetSplit returns Split atomically.
+func (s *TxStats) GetSplit() int64 {
+	return atomic.LoadInt64(&s.Split)
+}
+
+// IncSplit increases Split atomically and returns the new value.
+func (s *TxStats) IncSplit(delta int64) int64 {
+	return atomic.AddInt64(&s.Split, delta)
+}
+
+// GetSpill returns Spill atomically.
+func (s *TxStats) GetSpill() int64 {
+	return atomic.LoadInt64(&s.Spill)
+}
+
+// IncSpill increases Spill atomically and returns the new value.
+func (s *TxStats) IncSpill(delta int64) int64 {
+	return atomic.AddInt64(&s.Spill, delta)
+}
+
+// GetSpillTime returns SpillTime atomically.
+func (s *TxStats) GetSpillTime() time.Duration {
+	return atomicLoadDuration(&s.SpillTime)
+}
+
+// IncSpillTime increases SpillTime atomically and returns the new value.
+func (s *TxStats) IncSpillTime(delta time.Duration) time.Duration {
+	return atomicAddDuration(&s.SpillTime, delta)
+}
+
+// GetWrite returns Write atomically.
+func (s *TxStats) GetWrite() int64 {
+	return atomic.LoadInt64(&s.Write)
+}
+
+// IncWrite increases Write atomically and returns the new value.
+func (s *TxStats) IncWrite(delta int64) int64 {
+	return atomic.AddInt64(&s.Write, delta)
+}
+
+// GetWriteTime returns WriteTime atomically.
+func (s *TxStats) GetWriteTime() time.Duration {
+	return atomicLoadDuration(&s.WriteTime)
+}
+
+// IncWriteTime increases WriteTime atomically and returns the new value.
+func (s *TxStats) IncWriteTime(delta time.Duration) time.Duration {
+	return atomicAddDuration(&s.WriteTime, delta)
+}
+
+func atomicAddDuration(ptr *time.Duration, du time.Duration) time.Duration {
+	return time.Duration(atomic.AddInt64((*int64)(unsafe.Pointer(ptr)), int64(du)))
+}
+
+func atomicLoadDuration(ptr *time.Duration) time.Duration {
+	return time.Duration(atomic.LoadInt64((*int64)(unsafe.Pointer(ptr))))
+}
diff --git a/vendor/go.etcd.io/bbolt/tx_check.go b/vendor/go.etcd.io/bbolt/tx_check.go
new file mode 100644
index 0000000..c3ecbb9
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/tx_check.go
@@ -0,0 +1,290 @@
+package bbolt
+
+import (
+	"encoding/hex"
+	"fmt"
+
+	"go.etcd.io/bbolt/internal/common"
+)
+
+// Check performs several consistency checks on the database for this transaction.
+// An error is returned if any inconsistency is found.
+//
+// It can be safely run concurrently on a writable transaction. However, this
+// incurs a high cost for large databases and databases with a lot of subbuckets
+// because of caching. This overhead can be removed if running on a read-only
+// transaction, however, it is not safe to execute other writer transactions at
+// the same time.
+//
+// It also allows users to provide a customized `KVStringer` implementation,
+// so that bolt can generate human-readable diagnostic messages.
+func (tx *Tx) Check(options ...CheckOption) <-chan error {
+	chkConfig := checkConfig{
+		kvStringer: HexKVStringer(),
+	}
+	for _, op := range options {
+		op(&chkConfig)
+	}
+
+	ch := make(chan error)
+	go func() {
+		// Close the channel to signal completion.
+		defer close(ch)
+		tx.check(chkConfig, ch)
+	}()
+	return ch
+}
+
+func (tx *Tx) check(cfg checkConfig, ch chan error) {
+	// Force loading free list if opened in ReadOnly mode.
+	tx.db.loadFreelist()
+
+	// Check if any pages are double freed.
+	freed := make(map[common.Pgid]bool)
+	all := make([]common.Pgid, tx.db.freelist.Count())
+	tx.db.freelist.Copyall(all)
+	for _, id := range all {
+		if freed[id] {
+			ch <- fmt.Errorf("page %d: already freed", id)
+		}
+		freed[id] = true
+	}
+
+	// Track every reachable page.
+	reachable := make(map[common.Pgid]*common.Page)
+	reachable[0] = tx.page(0) // meta0
+	reachable[1] = tx.page(1) // meta1
+	if tx.meta.Freelist() != common.PgidNoFreelist {
+		for i := uint32(0); i <= tx.page(tx.meta.Freelist()).Overflow(); i++ {
+			reachable[tx.meta.Freelist()+common.Pgid(i)] = tx.page(tx.meta.Freelist())
+		}
+	}
+
+	if cfg.pageId == 0 {
+		// Check the whole db file, starting from the root bucket and
+		// recursively check all child buckets.
+		tx.recursivelyCheckBucket(&tx.root, reachable, freed, cfg.kvStringer, ch)
+
+		// Ensure all pages below high water mark are either reachable or freed.
+		for i := common.Pgid(0); i < tx.meta.Pgid(); i++ {
+			_, isReachable := reachable[i]
+			if !isReachable && !freed[i] {
+				ch <- fmt.Errorf("page %d: unreachable unfreed", int(i))
+			}
+		}
+	} else {
+		// Check the db file starting from a specified pageId.
+		if cfg.pageId < 2 || cfg.pageId >= uint64(tx.meta.Pgid()) {
+			ch <- fmt.Errorf("page ID (%d) out of range [%d, %d)", cfg.pageId, 2, tx.meta.Pgid())
+			return
+		}
+
+		tx.recursivelyCheckPage(common.Pgid(cfg.pageId), reachable, freed, cfg.kvStringer, ch)
+	}
+}
+
+func (tx *Tx) recursivelyCheckPage(pageId common.Pgid, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool,
+	kvStringer KVStringer, ch chan error) {
+	tx.checkInvariantProperties(pageId, reachable, freed, kvStringer, ch)
+	tx.recursivelyCheckBucketInPage(pageId, reachable, freed, kvStringer, ch)
+}
+
+func (tx *Tx) recursivelyCheckBucketInPage(pageId common.Pgid, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool,
+	kvStringer KVStringer, ch chan error) {
+	p := tx.page(pageId)
+
+	switch {
+	case p.IsBranchPage():
+		for i := range p.BranchPageElements() {
+			elem := p.BranchPageElement(uint16(i))
+			tx.recursivelyCheckBucketInPage(elem.Pgid(), reachable, freed, kvStringer, ch)
+		}
+	case p.IsLeafPage():
+		for i := range p.LeafPageElements() {
+			elem := p.LeafPageElement(uint16(i))
+			if elem.IsBucketEntry() {
+				inBkt := common.NewInBucket(pageId, 0)
+				tmpBucket := Bucket{
+					InBucket:    &inBkt,
+					rootNode:    &node{isLeaf: p.IsLeafPage()},
+					FillPercent: DefaultFillPercent,
+					tx:          tx,
+				}
+				if child := tmpBucket.Bucket(elem.Key()); child != nil {
+					tx.recursivelyCheckBucket(child, reachable, freed, kvStringer, ch)
+				}
+			}
+		}
+	default:
+		ch <- fmt.Errorf("unexpected page type (flags: %x) for pgId:%d", p.Flags(), pageId)
+	}
+}
+
+func (tx *Tx) recursivelyCheckBucket(b *Bucket, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool,
+	kvStringer KVStringer, ch chan error) {
+	// Ignore inline buckets.
+	if b.RootPage() == 0 {
+		return
+	}
+
+	tx.checkInvariantProperties(b.RootPage(), reachable, freed, kvStringer, ch)
+
+	// Check each bucket within this bucket.
+	_ = b.ForEachBucket(func(k []byte) error {
+		if child := b.Bucket(k); child != nil {
+			tx.recursivelyCheckBucket(child, reachable, freed, kvStringer, ch)
+		}
+		return nil
+	})
+}
+
+func (tx *Tx) checkInvariantProperties(pageId common.Pgid, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool,
+	kvStringer KVStringer, ch chan error) {
+	tx.forEachPage(pageId, func(p *common.Page, _ int, stack []common.Pgid) {
+		verifyPageReachable(p, tx.meta.Pgid(), stack, reachable, freed, ch)
+	})
+
+	tx.recursivelyCheckPageKeyOrder(pageId, kvStringer.KeyToString, ch)
+}
+
+func verifyPageReachable(p *common.Page, hwm common.Pgid, stack []common.Pgid, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool, ch chan error) {
+	if p.Id() > hwm {
+		ch <- fmt.Errorf("page %d: out of bounds: %d (stack: %v)", int(p.Id()), int(hwm), stack)
+	}
+
+	// Ensure each page is only referenced once.
+	for i := common.Pgid(0); i <= common.Pgid(p.Overflow()); i++ {
+		var id = p.Id() + i
+		if _, ok := reachable[id]; ok {
+			ch <- fmt.Errorf("page %d: multiple references (stack: %v)", int(id), stack)
+		}
+		reachable[id] = p
+	}
+
+	// We should only encounter un-freed leaf and branch pages.
+	if freed[p.Id()] {
+		ch <- fmt.Errorf("page %d: reachable freed", int(p.Id()))
+	} else if !p.IsBranchPage() && !p.IsLeafPage() {
+		ch <- fmt.Errorf("page %d: invalid type: %s (stack: %v)", int(p.Id()), p.Typ(), stack)
+	}
+}
+
+// recursivelyCheckPageKeyOrder verifies database consistency with respect to b-tree
+// key order constraints:
+//   - keys on pages must be sorted
+//   - keys on children pages are between 2 consecutive keys on the parent's branch page).
+func (tx *Tx) recursivelyCheckPageKeyOrder(pgId common.Pgid, keyToString func([]byte) string, ch chan error) {
+	tx.recursivelyCheckPageKeyOrderInternal(pgId, nil, nil, nil, keyToString, ch)
+}
+
+// recursivelyCheckPageKeyOrderInternal verifies that all keys in the subtree rooted at `pgid` are:
+//   - >=`minKeyClosed` (can be nil)
+//   - <`maxKeyOpen` (can be nil)
+//   - Are in right ordering relationship to their parents.
+//     `pagesStack` is expected to contain IDs of pages from the tree root to `pgid` for the clean debugging message.
+func (tx *Tx) recursivelyCheckPageKeyOrderInternal(
+	pgId common.Pgid, minKeyClosed, maxKeyOpen []byte, pagesStack []common.Pgid,
+	keyToString func([]byte) string, ch chan error) (maxKeyInSubtree []byte) {
+
+	p := tx.page(pgId)
+	pagesStack = append(pagesStack, pgId)
+	switch {
+	case p.IsBranchPage():
+		// For branch page we navigate ranges of all subpages.
+		runningMin := minKeyClosed
+		for i := range p.BranchPageElements() {
+			elem := p.BranchPageElement(uint16(i))
+			verifyKeyOrder(elem.Pgid(), "branch", i, elem.Key(), runningMin, maxKeyOpen, ch, keyToString, pagesStack)
+
+			maxKey := maxKeyOpen
+			if i < len(p.BranchPageElements())-1 {
+				maxKey = p.BranchPageElement(uint16(i + 1)).Key()
+			}
+			maxKeyInSubtree = tx.recursivelyCheckPageKeyOrderInternal(elem.Pgid(), elem.Key(), maxKey, pagesStack, keyToString, ch)
+			runningMin = maxKeyInSubtree
+		}
+		return maxKeyInSubtree
+	case p.IsLeafPage():
+		runningMin := minKeyClosed
+		for i := range p.LeafPageElements() {
+			elem := p.LeafPageElement(uint16(i))
+			verifyKeyOrder(pgId, "leaf", i, elem.Key(), runningMin, maxKeyOpen, ch, keyToString, pagesStack)
+			runningMin = elem.Key()
+		}
+		if p.Count() > 0 {
+			return p.LeafPageElement(p.Count() - 1).Key()
+		}
+	default:
+		ch <- fmt.Errorf("unexpected page type (flags: %x) for pgId:%d", p.Flags(), pgId)
+	}
+	return maxKeyInSubtree
+}
+
+/***
+ * verifyKeyOrder checks whether an entry with given #index on pgId (pageType: "branch|leaf") that has given "key",
+ * is within range determined by (previousKey..maxKeyOpen) and reports found violations to the channel (ch).
+ */
+func verifyKeyOrder(pgId common.Pgid, pageType string, index int, key []byte, previousKey []byte, maxKeyOpen []byte, ch chan error, keyToString func([]byte) string, pagesStack []common.Pgid) {
+	if index == 0 && previousKey != nil && compareKeys(previousKey, key) > 0 {
+		ch <- fmt.Errorf("the first key[%d]=(hex)%s on %s page(%d) needs to be >= the key in the ancestor (%s). Stack: %v",
+			index, keyToString(key), pageType, pgId, keyToString(previousKey), pagesStack)
+	}
+	if index > 0 {
+		cmpRet := compareKeys(previousKey, key)
+		if cmpRet > 0 {
+			ch <- fmt.Errorf("key[%d]=(hex)%s on %s page(%d) needs to be > (found <) than previous element (hex)%s. Stack: %v",
+				index, keyToString(key), pageType, pgId, keyToString(previousKey), pagesStack)
+		}
+		if cmpRet == 0 {
+			ch <- fmt.Errorf("key[%d]=(hex)%s on %s page(%d) needs to be > (found =) than previous element (hex)%s. Stack: %v",
+				index, keyToString(key), pageType, pgId, keyToString(previousKey), pagesStack)
+		}
+	}
+	if maxKeyOpen != nil && compareKeys(key, maxKeyOpen) >= 0 {
+		ch <- fmt.Errorf("key[%d]=(hex)%s on %s page(%d) needs to be < than key of the next element in ancestor (hex)%s. Pages stack: %v",
+			index, keyToString(key), pageType, pgId, keyToString(previousKey), pagesStack)
+	}
+}
+
+// ===========================================================================================
+
+type checkConfig struct {
+	kvStringer KVStringer
+	pageId     uint64
+}
+
+type CheckOption func(options *checkConfig)
+
+func WithKVStringer(kvStringer KVStringer) CheckOption {
+	return func(c *checkConfig) {
+		c.kvStringer = kvStringer
+	}
+}
+
+// WithPageId sets a page ID from which the check command starts to check
+func WithPageId(pageId uint64) CheckOption {
+	return func(c *checkConfig) {
+		c.pageId = pageId
+	}
+}
+
+// KVStringer allows to prepare human-readable diagnostic messages.
+type KVStringer interface {
+	KeyToString([]byte) string
+	ValueToString([]byte) string
+}
+
+// HexKVStringer serializes both key & value to hex representation.
+func HexKVStringer() KVStringer {
+	return hexKvStringer{}
+}
+
+type hexKvStringer struct{}
+
+func (_ hexKvStringer) KeyToString(key []byte) string {
+	return hex.EncodeToString(key)
+}
+
+func (_ hexKvStringer) ValueToString(value []byte) string {
+	return hex.EncodeToString(value)
+}