pkg/util: move trace.go to k8s.io/apiserver/pkg/util/trace

pkg/util/trace/trace.go

@@ -0,0 +1,72 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+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 trace
+
+import (
+	"bytes"
+	"fmt"
+	"time"
+
+	"github.com/golang/glog"
+)
+
+type traceStep struct {
+	stepTime time.Time
+	msg      string
+}
+
+type Trace struct {
+	name      string
+	startTime time.Time
+	steps     []traceStep
+}
+
+func New(name string) *Trace {
+	return &Trace{name, time.Now(), nil}
+}
+
+func (t *Trace) Step(msg string) {
+	if t.steps == nil {
+		// traces almost always have less than 6 steps, do this to avoid more than a single allocation
+		t.steps = make([]traceStep, 0, 6)
+	}
+	t.steps = append(t.steps, traceStep{time.Now(), msg})
+}
+
+func (t *Trace) Log() {
+	endTime := time.Now()
+	var buffer bytes.Buffer
+
+	buffer.WriteString(fmt.Sprintf("Trace %q (started %v):\n", t.name, t.startTime))
+	lastStepTime := t.startTime
+	for _, step := range t.steps {
+		buffer.WriteString(fmt.Sprintf("[%v] [%v] %v\n", step.stepTime.Sub(t.startTime), step.stepTime.Sub(lastStepTime), step.msg))
+		lastStepTime = step.stepTime
+	}
+	buffer.WriteString(fmt.Sprintf("[%v] [%v] END\n", endTime.Sub(t.startTime), endTime.Sub(lastStepTime)))
+	glog.Info(buffer.String())
+}
+
+func (t *Trace) LogIfLong(threshold time.Duration) {
+	if time.Since(t.startTime) >= threshold {
+		t.Log()
+	}
+}
+
+func (t *Trace) TotalTime() time.Duration {
+	return time.Since(t.startTime)
+}