1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
// 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++;
}
}
export 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 b.buf == nil {
b.cap = plen + 1024;
b.buf = new([]byte, b.cap);
b.len = 0;
}
if b.len + len(p) > b.cap {
b.cap = 2*(b.cap + plen);
nb := new([]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 b.buf == nil {
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
}
// If the buffer is empty, Data() should still give a valid array.
// Use this variable as a surrogate. It's immutable (can't be
// grown, can't store any data) so it's safe to share.
var EmptyByteArray = new([]byte, 0)
func (b *ByteBuffer) Data() *[]byte {
if b.buf == nil {
return EmptyByteArray
}
return b.buf[b.off:b.len]
}
export func NewByteBufferFromArray(buf *[]byte) *ByteBuffer {
b := new(ByteBuffer);
b.buf = buf;
b.off = 0;
b.len = len(buf);
b.cap = len(buf);
return b;
}
|
