First Commit of Voltha-Go-Controller from Radisys

Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/uber/jaeger-client-go/observer.go b/vendor/github.com/uber/jaeger-client-go/observer.go
new file mode 100644
index 0000000..7bbd028
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/observer.go
@@ -0,0 +1,88 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// 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 jaeger
+
+import opentracing "github.com/opentracing/opentracing-go"
+
+// Observer can be registered with the Tracer to receive notifications about
+// new Spans.
+//
+// Deprecated: use jaeger.ContribObserver instead.
+type Observer interface {
+	OnStartSpan(operationName string, options opentracing.StartSpanOptions) SpanObserver
+}
+
+// SpanObserver is created by the Observer and receives notifications about
+// other Span events.
+//
+// Deprecated: use jaeger.ContribSpanObserver instead.
+type SpanObserver interface {
+	OnSetOperationName(operationName string)
+	OnSetTag(key string, value interface{})
+	OnFinish(options opentracing.FinishOptions)
+}
+
+// compositeObserver is a dispatcher to other observers
+type compositeObserver struct {
+	observers []ContribObserver
+}
+
+// compositeSpanObserver is a dispatcher to other span observers
+type compositeSpanObserver struct {
+	observers []ContribSpanObserver
+}
+
+// noopSpanObserver is used when there are no observers registered
+// on the Tracer or none of them returns span observers from OnStartSpan.
+var noopSpanObserver = &compositeSpanObserver{}
+
+func (o *compositeObserver) append(contribObserver ContribObserver) {
+	o.observers = append(o.observers, contribObserver)
+}
+
+func (o *compositeObserver) OnStartSpan(sp opentracing.Span, operationName string, options opentracing.StartSpanOptions) ContribSpanObserver {
+	var spanObservers []ContribSpanObserver
+	for _, obs := range o.observers {
+		spanObs, ok := obs.OnStartSpan(sp, operationName, options)
+		if ok {
+			if spanObservers == nil {
+				spanObservers = make([]ContribSpanObserver, 0, len(o.observers))
+			}
+			spanObservers = append(spanObservers, spanObs)
+		}
+	}
+	if len(spanObservers) == 0 {
+		return noopSpanObserver
+	}
+	return &compositeSpanObserver{observers: spanObservers}
+}
+
+func (o *compositeSpanObserver) OnSetOperationName(operationName string) {
+	for _, obs := range o.observers {
+		obs.OnSetOperationName(operationName)
+	}
+}
+
+func (o *compositeSpanObserver) OnSetTag(key string, value interface{}) {
+	for _, obs := range o.observers {
+		obs.OnSetTag(key, value)
+	}
+}
+
+func (o *compositeSpanObserver) OnFinish(options opentracing.FinishOptions) {
+	for _, obs := range o.observers {
+		obs.OnFinish(options)
+	}
+}