[VOL-5291] On demand statistics for ONU and OLT

Change-Id: I4850bb0f0d2235122cb0c1bcf835b3672bb34436
Signed-off-by: Akash Reddy Kankanala <akash.kankanala@radisys.com>
diff --git a/vendor/google.golang.org/grpc/resolver/resolver.go b/vendor/google.golang.org/grpc/resolver/resolver.go
index e73a00d..353c10b 100644
--- a/vendor/google.golang.org/grpc/resolver/resolver.go
+++ b/vendor/google.golang.org/grpc/resolver/resolver.go
@@ -22,8 +22,10 @@
 
 import (
 	"context"
+	"fmt"
 	"net"
 	"net/url"
+	"strings"
 
 	"google.golang.org/grpc/attributes"
 	"google.golang.org/grpc/credentials"
@@ -39,8 +41,9 @@
 
 // TODO(bar) install dns resolver in init(){}.
 
-// Register registers the resolver builder to the resolver map. b.Scheme will be
-// used as the scheme registered with this builder.
+// Register registers the resolver builder to the resolver map. b.Scheme will
+// be used as the scheme registered with this builder. The registry is case
+// sensitive, and schemes should not contain any uppercase characters.
 //
 // NOTE: this function must only be called during initialization time (i.e. in
 // an init() function), and is not thread-safe. If multiple Resolvers are
@@ -121,7 +124,7 @@
 	Attributes *attributes.Attributes
 
 	// BalancerAttributes contains arbitrary data about this address intended
-	// for consumption by the LB policy.  These attribes do not affect SubConn
+	// for consumption by the LB policy.  These attributes do not affect SubConn
 	// creation, connection establishment, handshaking, etc.
 	BalancerAttributes *attributes.Attributes
 
@@ -139,13 +142,28 @@
 
 // Equal returns whether a and o are identical.  Metadata is compared directly,
 // not with any recursive introspection.
-func (a *Address) Equal(o Address) bool {
+func (a Address) Equal(o Address) bool {
 	return a.Addr == o.Addr && a.ServerName == o.ServerName &&
 		a.Attributes.Equal(o.Attributes) &&
 		a.BalancerAttributes.Equal(o.BalancerAttributes) &&
 		a.Type == o.Type && a.Metadata == o.Metadata
 }
 
+// String returns JSON formatted string representation of the address.
+func (a Address) String() string {
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("{Addr: %q, ", a.Addr))
+	sb.WriteString(fmt.Sprintf("ServerName: %q, ", a.ServerName))
+	if a.Attributes != nil {
+		sb.WriteString(fmt.Sprintf("Attributes: %v, ", a.Attributes.String()))
+	}
+	if a.BalancerAttributes != nil {
+		sb.WriteString(fmt.Sprintf("BalancerAttributes: %v", a.BalancerAttributes.String()))
+	}
+	sb.WriteString("}")
+	return sb.String()
+}
+
 // BuildOptions includes additional information for the builder to create
 // the resolver.
 type BuildOptions struct {
@@ -196,6 +214,15 @@
 // gRPC to add new methods to this interface.
 type ClientConn interface {
 	// UpdateState updates the state of the ClientConn appropriately.
+	//
+	// If an error is returned, the resolver should try to resolve the
+	// target again. The resolver should use a backoff timer to prevent
+	// overloading the server with requests. If a resolver is certain that
+	// reresolving will not change the result, e.g. because it is
+	// a watch-based resolver, returned errors can be ignored.
+	//
+	// If the resolved State is the same as the last reported one, calling
+	// UpdateState can be omitted.
 	UpdateState(State) error
 	// ReportError notifies the ClientConn that the Resolver encountered an
 	// error.  The ClientConn will notify the load balancer and begin calling
@@ -241,9 +268,6 @@
 	Scheme string
 	// Deprecated: use URL.Host instead.
 	Authority string
-	// Deprecated: use URL.Path or URL.Opaque instead. The latter is set when
-	// the former is empty.
-	Endpoint string
 	// URL contains the parsed dial target with an optional default scheme added
 	// to it if the original dial target contained no scheme or contained an
 	// unregistered scheme. Any query params specified in the original dial
@@ -251,6 +275,24 @@
 	URL url.URL
 }
 
+// Endpoint retrieves endpoint without leading "/" from either `URL.Path`
+// or `URL.Opaque`. The latter is used when the former is empty.
+func (t Target) Endpoint() string {
+	endpoint := t.URL.Path
+	if endpoint == "" {
+		endpoint = t.URL.Opaque
+	}
+	// For targets of the form "[scheme]://[authority]/endpoint, the endpoint
+	// value returned from url.Parse() contains a leading "/". Although this is
+	// in accordance with RFC 3986, we do not want to break existing resolver
+	// implementations which expect the endpoint without the leading "/". So, we
+	// end up stripping the leading "/" here. But this will result in an
+	// incorrect parsing for something like "unix:///path/to/socket". Since we
+	// own the "unix" resolver, we can workaround in the unix resolver by using
+	// the `URL` field.
+	return strings.TrimPrefix(endpoint, "/")
+}
+
 // Builder creates a resolver that will be used to watch name resolution updates.
 type Builder interface {
 	// Build creates a new resolver for the given target.
@@ -258,8 +300,10 @@
 	// gRPC dial calls Build synchronously, and fails if the returned error is
 	// not nil.
 	Build(target Target, cc ClientConn, opts BuildOptions) (Resolver, error)
-	// Scheme returns the scheme supported by this resolver.
-	// Scheme is defined at https://github.com/grpc/grpc/blob/master/doc/naming.md.
+	// Scheme returns the scheme supported by this resolver.  Scheme is defined
+	// at https://github.com/grpc/grpc/blob/master/doc/naming.md.  The returned
+	// string should not contain uppercase characters, as they will not match
+	// the parsed target's scheme as defined in RFC 3986.
 	Scheme() string
 }