Opentracing support

vendor/github.com/uber/jaeger-lib/metrics/stopwatch.go

@@ -0,0 +1,43 @@
+// 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 metrics
+
+import (
+	"time"
+)
+
+// StartStopwatch begins recording the executing time of an event, returning
+// a Stopwatch that should be used to stop the recording the time for
+// that event.  Multiple events can be occurring simultaneously each
+// represented by different active Stopwatches
+func StartStopwatch(timer Timer) Stopwatch {
+	return Stopwatch{t: timer, start: time.Now()}
+}
+
+// A Stopwatch tracks the execution time of a specific event
+type Stopwatch struct {
+	t     Timer
+	start time.Time
+}
+
+// Stop stops executing of the stopwatch and records the amount of elapsed time
+func (s Stopwatch) Stop() {
+	s.t.Record(s.ElapsedTime())
+}
+
+// ElapsedTime returns the amount of elapsed time (in time.Duration)
+func (s Stopwatch) ElapsedTime() time.Duration {
+	return time.Since(s.start)
+}