DynamicBuffer.h revision a05da9f4
1/*
2 * Copyright 2009-2014, Haiku, Inc. All Rights Reserved.
3 * Distributed under the terms of the MIT License.
4 *
5 * Authors:
6 *              Bruno Albuquerque, bga@bug-br.org.br
7 */
8
9#ifndef _DYNAMIC_BUFFER_H
10#define _DYNAMIC_BUFFER_H
11
12#include <DataIO.h>
13#include <SupportDefs.h>
14
15
16class DynamicBuffer : public BDataIO {
17public:
18	DynamicBuffer(size_t initialSize = 0);
19	~DynamicBuffer();
20
21	DynamicBuffer(const DynamicBuffer& buffer);
22
23	// InitCheck() should be called to guarantee the object initialization
24	// didn't fail. If it does not return B_OK, the initialization failed.
25	status_t InitCheck() const;
26
27	// Insert data at the end of the buffer. The buffer will be increased to
28	// accomodate the data if needed.
29	status_t Write(const void* data, size_t size);
30
31	// Remove data from the start of the buffer. Move the buffer start
32	// pointer to point to the data following it.
33	ssize_t Read(void* data, size_t size);
34
35	// Return a pointer to the underlying buffer. Note this will not
36	// necessarily be a pointer to the start of the allocated memory as the
37	// initial data may be positioned at an offset inside the buffer. In other
38	// words, this returns a pointer to the start of data inside the buffer.
39	unsigned char* Data() const;
40
41	// Returns the actual buffer size. This is the amount of memory allocated
42	// for the buffer.
43	size_t Size() const;
44
45	// Number of bytes of data still present in the buffer that can be
46	// extracted through calls to Remove().
47	size_t BytesRemaining() const;
48
49	// Dump some buffer statistics to stdout.
50	void PrintToStream();
51
52private:
53	status_t _GrowToFit(size_t size, bool exact = false);
54
55	unsigned char* fBuffer;
56	size_t fBufferSize;
57	size_t fDataStart;
58	size_t fDataEnd;
59
60	status_t fInit;
61};
62
63#endif  // _DYNAMIC_BUFFER_H
64