gob: move benchmarks to a new timing_test.go file.

Add malloc counts for encode and decode.

R=rsc
CC=golang-dev
https://golang.org/cl/4290048

src/pkg/gob/encoder_test.go

@@ -514,39 +514,3 @@ func TestNestedInterfaces(t *testing.T) {
 		t.Fatalf("final value %d; expected %d", inner.A, 7)
 	}
 }
-
-type Bench struct {
-	A int
-	B float64
-	C string
-	D []byte
-}
-
-func benchmarkEndToEnd(r io.Reader, w io.Writer, b *testing.B) {
-	b.StopTimer()
-	enc := NewEncoder(w)
-	dec := NewDecoder(r)
-	bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
-	b.StartTimer()
-	for i := 0; i < b.N; i++ {
-		if enc.Encode(bench) != nil {
-			panic("encode error")
-		}
-		if dec.Decode(bench) != nil {
-			panic("decode error")
-		}
-	}
-}
-
-func BenchmarkEndToEndPipe(b *testing.B) {
-	r, w, err := os.Pipe()
-	if err != nil {
-		panic("can't get pipe:" + err.String())
-	}
-	benchmarkEndToEnd(r, w, b)
-}
-
-func BenchmarkEndToEndByteBuffer(b *testing.B) {
-	var buf bytes.Buffer
-	benchmarkEndToEnd(&buf, &buf, b)
-}

src/pkg/gob/timing_test.go

+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gob
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"runtime/pprof"
+	"testing"
+)
+
+type Bench struct {
+	A int
+	B float64
+	C string
+	D []byte
+}
+
+var memprofile = flag.String("memprofile", "", "write the memory profile in Test*Mallocs to the named file")
+
+func benchmarkEndToEnd(r io.Reader, w io.Writer, b *testing.B) {
+	b.StopTimer()
+	enc := NewEncoder(w)
+	dec := NewDecoder(r)
+	bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		if enc.Encode(bench) != nil {
+			panic("encode error")
+		}
+		if dec.Decode(bench) != nil {
+			panic("decode error")
+		}
+	}
+}
+
+func BenchmarkEndToEndPipe(b *testing.B) {
+	r, w, err := os.Pipe()
+	if err != nil {
+		panic("can't get pipe:" + err.String())
+	}
+	benchmarkEndToEnd(r, w, b)
+}
+
+func BenchmarkEndToEndByteBuffer(b *testing.B) {
+	var buf bytes.Buffer
+	benchmarkEndToEnd(&buf, &buf, b)
+}
+
+func TestCountEncodeMallocs(t *testing.T) {
+	runtime.MemProfileRate = 1
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+	bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
+	mallocs := 0 - runtime.MemStats.Mallocs
+	const count = 1000
+	for i := 0; i < count; i++ {
+		err := enc.Encode(bench)
+		if err != nil {
+			t.Fatal("encode:", err)
+		}
+	}
+	mallocs += runtime.MemStats.Mallocs
+	if *memprofile != "" {
+		if fd, err := os.Open(*memprofile, os.O_WRONLY|os.O_CREAT|os.O_TRUNC, 0666); err != nil {
+			t.Errorf("can't open %s: %s", *memprofile, err)
+		} else {
+			if err = pprof.WriteHeapProfile(fd); err != nil {
+				t.Errorf("can't write %s: %s", *memprofile, err)
+			}
+			fd.Close()
+		}
+	}
+	fmt.Printf("mallocs per encode of type Bench: %d\n", mallocs/count)
+}
+
+func TestCountDecodeMallocs(t *testing.T) {
+	runtime.MemProfileRate = 1
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+	bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
+	const count = 1000
+	for i := 0; i < count; i++ {
+		err := enc.Encode(bench)
+		if err != nil {
+			t.Fatal("encode:", err)
+		}
+	}
+	dec := NewDecoder(&buf)
+	mallocs := 0 - runtime.MemStats.Mallocs
+	for i := 0; i < count; i++ {
+		*bench = Bench{}
+		err := dec.Decode(&bench)
+		if err != nil {
+			t.Fatal("decode:", err)
+		}
+	}
+	mallocs += runtime.MemStats.Mallocs
+	if *memprofile != "" {
+		if fd, err := os.Open(*memprofile, os.O_WRONLY|os.O_CREAT|os.O_TRUNC, 0666); err != nil {
+			t.Errorf("can't open %s: %s", *memprofile, err)
+		} else {
+			if err = pprof.WriteHeapProfile(fd); err != nil {
+				t.Errorf("can't write %s: %s", *memprofile, err)
+			}
+			fd.Close()
+		}
+	}
+	fmt.Printf("mallocs per decode of type Bench: %d\n", mallocs/count)
+}