1/****************************************************************************
2** libebml : parse EBML files, see http://embl.sourceforge.net/
3**
4** <file/class description>
5**
6** Copyright (C) 2003 Jory Stone.  All rights reserved.
7**
8** This library is free software; you can redistribute it and/or
9** modify it under the terms of the GNU Lesser General Public
10** License as published by the Free Software Foundation; either
11** version 2.1 of the License, or (at your option) any later version.
12**
13** This library is distributed in the hope that it will be useful,
14** but WITHOUT ANY WARRANTY; without even the implied warranty of
15** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16** Lesser General Public License for more details.
17**
18** You should have received a copy of the GNU Lesser General Public
19** License along with this library; if not, write to the Free Software
20** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21**
22** See http://www.matroska.org/license/lgpl/ for LGPL licensing information.
23**
24** Contact license@matroska.org if any conditions of this licensing are
25** not clear to you.
26**
27**********************************************************************/
28
29/*!
30	\file
31	\version \$Id: MemIOCallback.cpp 693 2004-07-31 08:56:28Z robux4 $
32	\author Jory Stone <jcsston @ toughguy.net>
33*/
34
35#include "ebml/MemIOCallback.h"
36#include "ebml/Debug.h"
37#include "ebml/EbmlConfig.h"
38
39START_LIBEBML_NAMESPACE
40
41MemIOCallback::MemIOCallback(uint64 DefaultSize)
42{
43	//The default size of the buffer is 128 bytes
44	dataBuffer = (binary *)malloc(DefaultSize);
45	if (dataBuffer == NULL) {
46		mOk = false;
47		std::stringstream Msg;
48		Msg << "Failed to alloc memory block of size ";
49// not working with VC6		Msg << DefaultSize;
50		mLastErrorStr = Msg.str();
51		return;
52	}
53
54	dataBufferMemorySize = DefaultSize;
55	dataBufferPos = 0;
56	dataBufferTotalSize = 0;
57	mOk = true;
58}
59
60MemIOCallback::~MemIOCallback()
61{
62	if (dataBuffer != NULL)
63		free(dataBuffer);
64}
65
66uint32 MemIOCallback::read(void *Buffer, size_t Size)
67{
68	if (Buffer == NULL || Size < 1)
69		return 0;
70	//If the size is larger than than the amount left in the buffer
71	if (Size + dataBufferPos > dataBufferTotalSize)
72	{
73		//We will only return the remaining data
74		memcpy(Buffer, dataBuffer + dataBufferPos, dataBufferTotalSize - dataBufferPos);
75		dataBufferPos = dataBufferTotalSize;
76		return dataBufferTotalSize - dataBufferPos;
77	}
78
79	//Well... We made it here, so do a quick and simple copy
80	memcpy(Buffer, dataBuffer+dataBufferPos, Size);
81	dataBufferPos += Size;
82
83	return Size;
84}
85
86void MemIOCallback::setFilePointer(int64 Offset, seek_mode Mode)
87{
88	if (Mode == seek_beginning)
89		dataBufferPos = Offset;
90	else if (Mode == seek_current)
91		dataBufferPos = dataBufferPos + Offset;
92	else if (Mode == seek_end)
93		dataBufferPos = dataBufferTotalSize + Offset;
94}
95
96size_t MemIOCallback::write(const void *Buffer, size_t Size)
97{
98	if (dataBufferMemorySize < dataBufferPos + Size)
99	{
100		//We need more memory!
101		dataBuffer = (binary *)realloc((void *)dataBuffer, dataBufferPos + Size);
102	}
103	memcpy(dataBuffer+dataBufferPos, Buffer, Size);
104	dataBufferPos += Size;
105	if (dataBufferPos > dataBufferTotalSize)
106		dataBufferTotalSize = dataBufferPos;
107
108	return Size;
109}
110
111uint32 MemIOCallback::write(IOCallback & IOToRead, size_t Size)
112{
113	if (dataBufferMemorySize < dataBufferPos + Size)
114	{
115		//We need more memory!
116		dataBuffer = (binary *)realloc((void *)dataBuffer, dataBufferPos + Size);
117	}
118	IOToRead.readFully(&dataBuffer[dataBufferPos], Size);
119	dataBufferTotalSize = Size;
120	return Size;
121}
122
123END_LIBEBML_NAMESPACE
124