encoding/gob: use simple append-only buffer for encoding
Bytes buffers have more API and are a little slower. Since appending
is a key part of the path in encode, using a faster implementation
speeds things up measurably.
The couple of positive swings are likely garbage-collection related
since memory allocation looks different in the benchmark now.
I am not concerned by them.
benchmark old ns/op new ns/op delta
BenchmarkEndToEndPipe 6620 6388 -3.50%
BenchmarkEndToEndByteBuffer 3548 3600 +1.47%
BenchmarkEndToEndSliceByteBuffer 336678 367980 +9.30%
BenchmarkEncodeComplex128Slice 78199 71297 -8.83%
BenchmarkEncodeFloat64Slice 37731 32258 -14.51%
BenchmarkEncodeInt32Slice 26780 22977 -14.20%
BenchmarkEncodeStringSlice 35882 26492 -26.17%
BenchmarkDecodeComplex128Slice 194819 185126 -4.98%
BenchmarkDecodeFloat64Slice 120538 120102 -0.36%
BenchmarkDecodeInt32Slice 106442 107275 +0.78%
BenchmarkDecodeStringSlice 272902 269866 -1.11%
LGTM=ruiu
R=golang-codereviews, ruiu
CC=golang-codereviews
https://golang.org/cl/160990043
diff --git a/src/encoding/gob/codec_test.go b/src/encoding/gob/codec_test.go
index 4f17a28..b3749e3 100644
--- a/src/encoding/gob/codec_test.go
+++ b/src/encoding/gob/codec_test.go
@@ -53,7 +53,7 @@
// Test basic encode/decode routines for unsigned integers
func TestUintCodec(t *testing.T) {
defer testError(t)
- b := new(bytes.Buffer)
+ b := new(encBuffer)
encState := newEncoderState(b)
for _, tt := range encodeT {
b.Reset()
@@ -62,10 +62,10 @@
t.Errorf("encodeUint: %#x encode: expected % x got % x", tt.x, tt.b, b.Bytes())
}
}
- decState := newDecodeState(b)
for u := uint64(0); ; u = (u + 1) * 7 {
b.Reset()
encState.encodeUint(u)
+ decState := newDecodeState(bytes.NewBuffer(b.Bytes()))
v := decState.decodeUint()
if u != v {
t.Errorf("Encode/Decode: sent %#x received %#x", u, v)
@@ -78,10 +78,10 @@
func verifyInt(i int64, t *testing.T) {
defer testError(t)
- var b = new(bytes.Buffer)
+ var b = new(encBuffer)
encState := newEncoderState(b)
encState.encodeInt(i)
- decState := newDecodeState(b)
+ decState := newDecodeState(bytes.NewBuffer(b.Bytes()))
decState.buf = make([]byte, 8)
j := decState.decodeInt()
if i != j {
@@ -125,7 +125,7 @@
return d
}
-func newEncoderState(b *bytes.Buffer) *encoderState {
+func newEncoderState(b *encBuffer) *encoderState {
b.Reset()
state := &encoderState{enc: nil, b: b}
state.fieldnum = -1
@@ -135,7 +135,7 @@
// Test instruction execution for encoding.
// Do not run the machine yet; instead do individual instructions crafted by hand.
func TestScalarEncInstructions(t *testing.T) {
- var b = new(bytes.Buffer)
+ var b = new(encBuffer)
// bool
{