VOL-4019: Initial commit with grpc nbi, sbi, etcd, kafka and hw management rpcs.

Change-Id: I78feaf7da284028fc61f42c5e0c5f56e72fe9e78
diff --git a/pkg/models/device/models.go b/pkg/models/device/models.go
new file mode 100644
index 0000000..ab9611d
--- /dev/null
+++ b/pkg/models/device/models.go
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2020-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Package device stores methods and functions related to device
+package device
+
+import (
+	"context"
+	"sync"
+
+	"github.com/opencord/device-management-interface/go/dmi"
+
+	"github.com/jinzhu/copier"
+	"github.com/opencord/opendevice-manager/pkg/config"
+
+	v1 "github.com/opencord/opendevice-manager/pkg/models/device/v1"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
+)
+
+// Constants defined are the DB Path meant for storing device info records
+const (
+	DbPathUuidToName   = config.DBPrefix + config.CurDBVer + "/DevRec/DevUuid/%s"
+	DbPathNameToRecord = config.DBPrefix + config.CurDBVer + "/DevRec/DevName/%s"
+)
+
+// deviceCache stores device informations in buffer
+type deviceCache struct {
+	nameToRec  *sync.Map // nameToRecord maintains cache for mapping from name to main record
+	uuidToName *sync.Map // uuidToName maintains cache for mapping from uuid to name
+}
+
+var cache *deviceCache
+
+// logger represents the log object
+var logger log.CLogger
+
+// initCache initialises device cache
+func initCache() {
+	cache = new(deviceCache)
+	cache.nameToRec = new(sync.Map)
+	cache.uuidToName = new(sync.Map)
+}
+
+// init function for the package
+func init() {
+	logger = config.Initlog()
+	initCache()
+}
+
+// ClearCacheEntry clearsentry from device cache
+func ClearCacheEntry(ctx context.Context, name, uuid string) {
+	if name != "" {
+		logger.Debugw(ctx, "Clearing-name-key-from-device-cache", log.Fields{"name": name})
+		cache.nameToRec.Delete(name)
+	}
+	if uuid != "" {
+		logger.Debugw(ctx, "Clearing-uuid-key-from-device-cache", log.Fields{"uuid": uuid})
+		cache.uuidToName.Delete(name)
+	}
+}
+
+// DeviceRecord refers to the structure defined for storing OLT info
+type DeviceRecord v1.DeviceRecordV1_0
+
+// NewDeviceRecord return record for aliased ModifiableComponent
+func NewDeviceRecord(ctx context.Context, req *dmi.ModifiableComponent) (*DeviceRecord, error) {
+	rec := new(DeviceRecord)
+	err := copier.Copy(&rec, &req)
+	if err != nil {
+		logger.Errorw(ctx, "Failed-at-creating-object-for-new-device-info", log.Fields{"error": err, "req": req})
+		return nil, err
+	}
+	rec.Uri = req.Uri.Uri
+	rec.State = new(dmi.ComponentState)
+	rec.State.AdminState = req.AdminState
+	logger.Infow(ctx, "Successful-at-creating-object-for-new-device-info", log.Fields{"new-object": rec})
+	return rec, nil
+}