Add a benchmark package to store and monitor timings. (#367)

pkg/timing/timing.go

@@ -0,0 +1,90 @@
+/*
+Copyright 2018 Google LLC
+
+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 timing
+
+import (
+	"bytes"
+	"fmt"
+	"sync"
+	"text/template"
+	"time"
+)
+
+// For testing
+var currentTimeFunc = time.Now
+
+// DefaultRun is the default "singleton" TimedRun instance.
+var DefaultRun = NewTimedRun()
+
+// TimedRun provides a running store of how long is spent in each category.
+type TimedRun struct {
+	cl         sync.Mutex
+	categories map[string]time.Duration // protected by cl
+}
+
+// Stop stops the specified timer and increments the time spent in that category.
+func (tr *TimedRun) Stop(t *Timer) {
+	stop := currentTimeFunc()
+	if _, ok := tr.categories[t.category]; !ok {
+		tr.categories[t.category] = 0
+	}
+	fmt.Println(stop)
+	tr.cl.Lock()
+	defer tr.cl.Unlock()
+	tr.categories[t.category] += stop.Sub(t.startTime)
+}
+
+// Start starts a new Timer and returns it.
+func Start(category string) *Timer {
+	t := Timer{
+		category:  category,
+		startTime: currentTimeFunc(),
+	}
+	return &t
+}
+
+// NewTimedRun returns an initialized TimedRun instance.
+func NewTimedRun() *TimedRun {
+	tr := TimedRun{
+		categories: map[string]time.Duration{},
+	}
+	return &tr
+}
+
+// Timer represents a running timer.
+type Timer struct {
+	category  string
+	startTime time.Time
+}
+
+// DefaultFormat is a default format string used by Summary.
+var DefaultFormat = template.Must(template.New("").Parse("{{range $c, $t := .}}{{$c}}: {{$t}}\n{{end}}"))
+
+// Summary outputs a summary of the DefaultTimedRun.
+func Summary() string {
+	return DefaultRun.Summary()
+}
+
+// Summary outputs a summary of the specified TimedRun.
+func (tr *TimedRun) Summary() string {
+	b := bytes.Buffer{}
+
+	tr.cl.Lock()
+	defer tr.cl.Unlock()
+	DefaultFormat.Execute(&b, tr.categories)
+	return b.String()
+}

pkg/timing/timing_test.go

@@ -0,0 +1,139 @@
+/*
+Copyright 2018 Google LLC
+
+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 timing
+
+import (
+	"testing"
+	"time"
+)
+
+func patchTime(timeFunc func() time.Time) func() {
+	old := currentTimeFunc
+	currentTimeFunc = timeFunc
+	return func() {
+		currentTimeFunc = old
+	}
+}
+
+func mockTimeFunc(t time.Time) func() time.Time {
+	return func() time.Time {
+		return t
+	}
+}
+
+func TestTimedRun_StartStop(t *testing.T) {
+	type args struct {
+		categories map[string]time.Duration
+		category   string
+		waitTime   time.Duration
+	}
+	tests := []struct {
+		name string
+		args args
+		want time.Duration
+	}{
+		{
+			name: "new category",
+			args: args{
+				categories: map[string]time.Duration{},
+				category:   "foo",
+				waitTime:   3 * time.Second,
+			},
+			want: 3 * time.Second,
+		},
+		{
+			name: "existing category",
+			args: args{
+				categories: map[string]time.Duration{
+					"foo": 4 * time.Second,
+				},
+				category: "foo",
+				waitTime: 2 * time.Second,
+			},
+			want: 6 * time.Second,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tr := &TimedRun{
+				categories: tt.args.categories,
+			}
+
+			timer := Timer{
+				category:  tt.args.category,
+				startTime: time.Time{},
+			}
+
+			defer patchTime(mockTimeFunc(timer.startTime.Add(tt.args.waitTime)))()
+			tr.Stop(&timer)
+			if got := tr.categories[tt.args.category]; got != tt.want {
+				t.Errorf("Expected %d, got %d", tt.want, got)
+			}
+		})
+	}
+}
+
+func TestTimedRun_Summary(t *testing.T) {
+	type fields struct {
+		categories map[string]time.Duration
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		want   string
+	}{
+		{
+			name: "single key",
+			fields: fields{
+				categories: map[string]time.Duration{
+					"foo": 3 * time.Second,
+				},
+			},
+			want: "foo: 3s\n",
+		},
+		{
+			name: "two keys",
+			fields: fields{
+				categories: map[string]time.Duration{
+					"foo": 3 * time.Second,
+					"bar": 1 * time.Second,
+				},
+			},
+			want: "bar: 1s\nfoo: 3s\n",
+		},
+		{
+			name: "units",
+			fields: fields{
+				categories: map[string]time.Duration{
+					"foo": 3 * time.Second,
+					"bar": 1 * time.Millisecond,
+				},
+			},
+			want: "bar: 1ms\nfoo: 3s\n",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tr := &TimedRun{
+				categories: tt.fields.categories,
+			}
+			if got := tr.Summary(); got != tt.want {
+				t.Errorf("TimedRun.Summary() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}