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
|
/*
* Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef _BUFFER_
#define _BUFFER_
// A Buffer is the backing store for the IOBuf abstraction and
// supports producer-consumer filling and draining.
class Buffer {
public:
Buffer(int bufSize);
~Buffer();
char* fillPos(); // Position of the place where buffer should be filled
int remaining(); // Number of bytes that can be placed starting at fillPos
int size(); // Size of the buffer
// Move up fill position by amount (decreases remaining()); returns
// false if not enough space
bool incrFillPos(int amt);
// Read single byte (0..255); returns -1 if no data available.
int readByte();
// Read multiple bytes, non-blocking (this buffer does not define a
// fill mechanism), into provided buffer. Returns number of bytes read.
int readBytes(char* buf, int len);
// Access to drain position. Be very careful using this.
char* drainPos();
int drainRemaining();
bool incrDrainPos(int amt);
// Compact buffer, removing already-consumed input. This must be
// called periodically to yield the illusion of an infinite buffer.
void compact();
private:
Buffer(const Buffer&);
Buffer& operator=(const Buffer&);
char* buf;
int sz;
int fill;
int drain;
};
#endif // #defined _BUFFER_
|