From: Joe Tsai Date: Wed, 16 Feb 2022 00:59:59 +0000 (-0800) Subject: encoding/binary: add AppendByteOrder X-Git-Tag: go1.19beta1~1192 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=986b04c0f12efa1c57293f147a9e734ec71f0363;p=gostls13.git encoding/binary: add AppendByteOrder AppendByteOrder specifies new methods for LittleEndian and BigEndian for appending an unsigned integer to a byte slice. The performance of AppendXXX methods are slower than PutXXX methods since the former needs to do a few slice operations, while the latter is essentially a single integer store. In practice, existing usages of PutXXX performed slicing operations around the call such that this cost was present, regardless. name time/op PutUint16-24 0.48ns ± 2% AppendUint16-24 1.54ns ± 1% PutUint32-24 0.46ns ± 2% AppendUint32-24 0.89ns ± 1% PutUint64-24 0.46ns ± 2% AppendUint64-24 0.89ns ± 1% LittleEndianPutUint16-24 0.47ns ± 2% LittleEndianAppendUint16-24 1.54ns ± 1% LittleEndianPutUint32-24 0.45ns ± 3% LittleEndianAppendUint32-24 0.92ns ± 2% LittleEndianPutUint64-24 0.46ns ± 3% LittleEndianAppendUint64-24 0.95ns ± 4% Fixes #50601 Change-Id: I33d2bbc93a3ce01a9269feac33a2432bc1166ead Reviewed-on: https://go-review.googlesource.com/c/go/+/386017 Trust: Joseph Tsai Trust: Josh Bleecher Snyder Reviewed-by: Josh Bleecher Snyder Run-TryBot: Joseph Tsai TryBot-Result: Gopher Robot --- diff --git a/src/encoding/binary/binary.go b/src/encoding/binary/binary.go index ee933461ee..0681511fbb 100644 --- a/src/encoding/binary/binary.go +++ b/src/encoding/binary/binary.go @@ -29,7 +29,7 @@ import ( "sync" ) -// A ByteOrder specifies how to convert byte sequences into +// A ByteOrder specifies how to convert byte slices into // 16-, 32-, or 64-bit unsigned integers. type ByteOrder interface { Uint16([]byte) uint16 @@ -41,10 +41,19 @@ type ByteOrder interface { String() string } -// LittleEndian is the little-endian implementation of ByteOrder. +// AppendByteOrder specifies how to append 16-, 32-, or 64-bit unsigned integers +// into a byte slice. +type AppendByteOrder interface { + AppendUint16([]byte, uint16) []byte + AppendUint32([]byte, uint32) []byte + AppendUint64([]byte, uint64) []byte + String() string +} + +// LittleEndian is the little-endian implementation of ByteOrder and AppendByteOrder. var LittleEndian littleEndian -// BigEndian is the big-endian implementation of ByteOrder. +// BigEndian is the big-endian implementation of ByteOrder and AppendByteOrder. var BigEndian bigEndian type littleEndian struct{} @@ -60,6 +69,13 @@ func (littleEndian) PutUint16(b []byte, v uint16) { b[1] = byte(v >> 8) } +func (littleEndian) AppendUint16(b []byte, v uint16) []byte { + return append(b, + byte(v), + byte(v>>8), + ) +} + func (littleEndian) Uint32(b []byte) uint32 { _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 @@ -73,6 +89,15 @@ func (littleEndian) PutUint32(b []byte, v uint32) { b[3] = byte(v >> 24) } +func (littleEndian) AppendUint32(b []byte, v uint32) []byte { + return append(b, + byte(v), + byte(v>>8), + byte(v>>16), + byte(v>>24), + ) +} + func (littleEndian) Uint64(b []byte) uint64 { _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | @@ -91,6 +116,19 @@ func (littleEndian) PutUint64(b []byte, v uint64) { b[7] = byte(v >> 56) } +func (littleEndian) AppendUint64(b []byte, v uint64) []byte { + return append(b, + byte(v), + byte(v>>8), + byte(v>>16), + byte(v>>24), + byte(v>>32), + byte(v>>40), + byte(v>>48), + byte(v>>56), + ) +} + func (littleEndian) String() string { return "LittleEndian" } func (littleEndian) GoString() string { return "binary.LittleEndian" } @@ -108,6 +146,13 @@ func (bigEndian) PutUint16(b []byte, v uint16) { b[1] = byte(v) } +func (bigEndian) AppendUint16(b []byte, v uint16) []byte { + return append(b, + byte(v>>8), + byte(v), + ) +} + func (bigEndian) Uint32(b []byte) uint32 { _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24 @@ -121,6 +166,15 @@ func (bigEndian) PutUint32(b []byte, v uint32) { b[3] = byte(v) } +func (bigEndian) AppendUint32(b []byte, v uint32) []byte { + return append(b, + byte(v>>24), + byte(v>>16), + byte(v>>8), + byte(v), + ) +} + func (bigEndian) Uint64(b []byte) uint64 { _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | @@ -139,6 +193,19 @@ func (bigEndian) PutUint64(b []byte, v uint64) { b[7] = byte(v) } +func (bigEndian) AppendUint64(b []byte, v uint64) []byte { + return append(b, + byte(v>>56), + byte(v>>48), + byte(v>>40), + byte(v>>32), + byte(v>>24), + byte(v>>16), + byte(v>>8), + byte(v), + ) +} + func (bigEndian) String() string { return "BigEndian" } func (bigEndian) GoString() string { return "binary.BigEndian" } diff --git a/src/encoding/binary/binary_test.go b/src/encoding/binary/binary_test.go index 9e1b5f12db..09d08f5ee3 100644 --- a/src/encoding/binary/binary_test.go +++ b/src/encoding/binary/binary_test.go @@ -442,6 +442,65 @@ func testPutUint64SmallSliceLengthPanics() (panicked bool) { return false } +func TestByteOrder(t *testing.T) { + type byteOrder interface { + ByteOrder + AppendByteOrder + } + buf := make([]byte, 8) + for _, order := range []byteOrder{LittleEndian, BigEndian} { + const offset = 3 + for _, value := range []uint64{ + 0x0000000000000000, + 0x0123456789abcdef, + 0xfedcba9876543210, + 0xffffffffffffffff, + 0xaaaaaaaaaaaaaaaa, + math.Float64bits(math.Pi), + math.Float64bits(math.E), + } { + want16 := uint16(value) + order.PutUint16(buf[:2], want16) + if got := order.Uint16(buf[:2]); got != want16 { + t.Errorf("PutUint16: Uint16 = %v, want %v", got, want16) + } + buf = order.AppendUint16(buf[:offset], want16) + if got := order.Uint16(buf[offset:]); got != want16 { + t.Errorf("AppendUint16: Uint16 = %v, want %v", got, want16) + } + if len(buf) != offset+2 { + t.Errorf("AppendUint16: len(buf) = %d, want %d", len(buf), offset+2) + } + + want32 := uint32(value) + order.PutUint32(buf[:4], want32) + if got := order.Uint32(buf[:4]); got != want32 { + t.Errorf("PutUint32: Uint32 = %v, want %v", got, want32) + } + buf = order.AppendUint32(buf[:offset], want32) + if got := order.Uint32(buf[offset:]); got != want32 { + t.Errorf("AppendUint32: Uint32 = %v, want %v", got, want32) + } + if len(buf) != offset+4 { + t.Errorf("AppendUint32: len(buf) = %d, want %d", len(buf), offset+4) + } + + want64 := uint64(value) + order.PutUint64(buf[:8], want64) + if got := order.Uint64(buf[:8]); got != want64 { + t.Errorf("PutUint64: Uint64 = %v, want %v", got, want64) + } + buf = order.AppendUint64(buf[:offset], want64) + if got := order.Uint64(buf[offset:]); got != want64 { + t.Errorf("AppendUint64: Uint64 = %v, want %v", got, want64) + } + if len(buf) != offset+8 { + t.Errorf("AppendUint64: len(buf) = %d, want %d", len(buf), offset+8) + } + } + } +} + func TestEarlyBoundsChecks(t *testing.T) { if testUint64SmallSliceLengthPanics() != true { t.Errorf("binary.LittleEndian.Uint64 expected to panic for small slices, but didn't") @@ -596,41 +655,84 @@ func BenchmarkWriteSlice1000Int32s(b *testing.B) { func BenchmarkPutUint16(b *testing.B) { b.SetBytes(2) for i := 0; i < b.N; i++ { - BigEndian.PutUint16(putbuf[:], uint16(i)) + BigEndian.PutUint16(putbuf[:2], uint16(i)) + } +} + +func BenchmarkAppendUint16(b *testing.B) { + b.SetBytes(2) + for i := 0; i < b.N; i++ { + putbuf = BigEndian.AppendUint16(putbuf[:0], uint16(i)) } } func BenchmarkPutUint32(b *testing.B) { b.SetBytes(4) for i := 0; i < b.N; i++ { - BigEndian.PutUint32(putbuf[:], uint32(i)) + BigEndian.PutUint32(putbuf[:4], uint32(i)) + } +} + +func BenchmarkAppendUint32(b *testing.B) { + b.SetBytes(4) + for i := 0; i < b.N; i++ { + putbuf = BigEndian.AppendUint32(putbuf[:0], uint32(i)) } } func BenchmarkPutUint64(b *testing.B) { b.SetBytes(8) for i := 0; i < b.N; i++ { - BigEndian.PutUint64(putbuf[:], uint64(i)) + BigEndian.PutUint64(putbuf[:8], uint64(i)) + } +} + +func BenchmarkAppendUint64(b *testing.B) { + b.SetBytes(8) + for i := 0; i < b.N; i++ { + putbuf = BigEndian.AppendUint64(putbuf[:0], uint64(i)) } } + func BenchmarkLittleEndianPutUint16(b *testing.B) { b.SetBytes(2) for i := 0; i < b.N; i++ { - LittleEndian.PutUint16(putbuf[:], uint16(i)) + LittleEndian.PutUint16(putbuf[:2], uint16(i)) + } +} + +func BenchmarkLittleEndianAppendUint16(b *testing.B) { + b.SetBytes(2) + for i := 0; i < b.N; i++ { + putbuf = LittleEndian.AppendUint16(putbuf[:0], uint16(i)) } } func BenchmarkLittleEndianPutUint32(b *testing.B) { b.SetBytes(4) for i := 0; i < b.N; i++ { - LittleEndian.PutUint32(putbuf[:], uint32(i)) + LittleEndian.PutUint32(putbuf[:4], uint32(i)) + } +} + +func BenchmarkLittleEndianAppendUint32(b *testing.B) { + b.SetBytes(4) + for i := 0; i < b.N; i++ { + putbuf = LittleEndian.AppendUint32(putbuf[:0], uint32(i)) } } func BenchmarkLittleEndianPutUint64(b *testing.B) { b.SetBytes(8) for i := 0; i < b.N; i++ { - LittleEndian.PutUint64(putbuf[:], uint64(i)) + LittleEndian.PutUint64(putbuf[:8], uint64(i)) + } +} + +func BenchmarkLittleEndianAppendUint64(b *testing.B) { + b.SetBytes(8) + for i := 0; i < b.N; i++ { + putbuf = LittleEndian.AppendUint64(putbuf[:0], uint64(i)) } }