mirror of
https://github.com/golang/go
synced 2024-10-05 06:11:21 -06:00
839a68469b
TBR=r OCL=23121 CL=23127
98 lines
1.8 KiB
Go
98 lines
1.8 KiB
Go
// Copyright 2009 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 io
|
|
|
|
// Byte buffer for marshaling nested messages.
|
|
|
|
import (
|
|
"io";
|
|
"os";
|
|
)
|
|
|
|
// A simple implementation of the io.Read and io.Write interfaces.
|
|
// A newly allocated ByteBuffer is ready to use.
|
|
|
|
// TODO(r): Do better memory management.
|
|
|
|
func bytecopy(dst []byte, doff int, src []byte, soff int, count int) {
|
|
for i := 0; i < count; i++ {
|
|
dst[doff] = src[soff];
|
|
doff++;
|
|
soff++;
|
|
}
|
|
}
|
|
|
|
type ByteBuffer struct {
|
|
buf []byte;
|
|
off int; // Read from here
|
|
len int; // Write to here
|
|
cap int;
|
|
}
|
|
|
|
func (b *ByteBuffer) Reset() {
|
|
b.off = 0;
|
|
b.len = 0;
|
|
}
|
|
|
|
func (b *ByteBuffer) Write(p []byte) (n int, err *os.Error) {
|
|
plen := len(p);
|
|
if len(b.buf) == 0 {
|
|
b.cap = plen + 1024;
|
|
b.buf = make([]byte, b.cap);
|
|
b.len = 0;
|
|
}
|
|
if b.len + len(p) > b.cap {
|
|
b.cap = 2*(b.cap + plen);
|
|
nb := make([]byte, b.cap);
|
|
bytecopy(nb, 0, b.buf, 0, b.len);
|
|
b.buf = nb;
|
|
}
|
|
bytecopy(b.buf, b.len, p, 0, plen);
|
|
b.len += plen;
|
|
return plen, nil;
|
|
}
|
|
|
|
func (b *ByteBuffer) Read(p []byte) (n int, err *os.Error) {
|
|
plen := len(p);
|
|
if len(b.buf) == 0 {
|
|
return 0, nil
|
|
}
|
|
if b.off == b.len { // empty buffer
|
|
b.Reset();
|
|
return 0, nil
|
|
}
|
|
if plen > b.len - b.off {
|
|
plen = b.len - b.off
|
|
}
|
|
bytecopy(p, 0, b.buf, b.off, plen);
|
|
b.off += plen;
|
|
return plen, nil;
|
|
}
|
|
|
|
func (b *ByteBuffer) Len() int {
|
|
return b.len
|
|
}
|
|
|
|
func (b *ByteBuffer) Off() int {
|
|
return b.off
|
|
}
|
|
|
|
func (b *ByteBuffer) Data() []byte {
|
|
return b.buf[b.off:b.len]
|
|
}
|
|
|
|
func (b *ByteBuffer) AllData() []byte {
|
|
return b.buf[0:b.len]
|
|
}
|
|
|
|
func NewByteBufferFromArray(buf []byte) *ByteBuffer {
|
|
b := new(ByteBuffer);
|
|
b.buf = buf;
|
|
b.off = 0;
|
|
b.len = len(buf);
|
|
b.cap = len(buf);
|
|
return b;
|
|
}
|