1/****************************************************************************
2** libebml : parse EBML files, see http://embl.sourceforge.net/
3**
4** <file/class description>
5**
6** Copyright (C) 2002-2005 Steve Lhomme.  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: EbmlSInteger.cpp 1079 2005-03-03 13:18:14Z robux4 $
32	\author Steve Lhomme     <robux4 @ users.sf.net>
33	\author Moritz Bunkus <moritz @ bunkus.org>
34*/
35#include <cassert>
36
37#include "ebml/EbmlSInteger.h"
38
39START_LIBEBML_NAMESPACE
40
41EbmlSInteger::EbmlSInteger()
42 :EbmlElement(DEFAULT_INT_SIZE, false)
43{}
44
45EbmlSInteger::EbmlSInteger(const int64 aDefaultValue)
46 :EbmlElement(DEFAULT_INT_SIZE, true), Value(aDefaultValue)
47{
48	DefaultIsSet = true;
49}
50
51EbmlSInteger::EbmlSInteger(const EbmlSInteger & ElementToClone)
52 :EbmlElement(ElementToClone)
53 ,Value(ElementToClone.Value)
54 ,DefaultValue(ElementToClone.DefaultValue)
55{
56}
57
58/*!
59	\todo handle exception on errors
60*/
61uint32 EbmlSInteger::RenderData(IOCallback & output, bool bForceRender, bool bKeepIntact)
62{
63	binary FinalData[8]; // we don't handle more than 64 bits integers
64	unsigned int i;
65
66	if (SizeLength > 8)
67		return 0; // integer bigger coded on more than 64 bits are not supported
68
69	int64 TempValue = Value;
70	for (i=0; i<Size;i++) {
71		FinalData[Size-i-1] = binary(TempValue & 0xFF);
72		TempValue >>= 8;
73	}
74
75	output.writeFully(FinalData,Size);
76
77	return Size;
78}
79
80uint64 EbmlSInteger::UpdateSize(bool bKeepIntact, bool bForceRender)
81{
82	if (!bKeepIntact && IsDefaultValue())
83		return 0;
84
85	if (Value <= 0x7F && Value >= (-0x80)) {
86		Size = 1;
87	} else if (Value <= 0x7FFF && Value >= (-0x8000)) {
88		Size = 2;
89	} else if (Value <= 0x7FFFFF && Value >= (-0x800000)) {
90		Size = 3;
91	} else if (Value <= 0x7FFFFFFF && Value >= (-0x80000000)) {
92		Size = 4;
93	} else if (Value <= EBML_PRETTYLONGINT(0x7FFFFFFFFF) &&
94		   Value >= EBML_PRETTYLONGINT(-0x8000000000)) {
95		Size = 5;
96	} else if (Value <= EBML_PRETTYLONGINT(0x7FFFFFFFFFFF) &&
97		   Value >= EBML_PRETTYLONGINT(-0x800000000000)) {
98		Size = 6;
99	} else if (Value <= EBML_PRETTYLONGINT(0x7FFFFFFFFFFFFF) &&
100		   Value >= EBML_PRETTYLONGINT(-0x80000000000000)) {
101		Size = 7;
102	} else {
103		Size = 8;
104	}
105
106	if (DefaultSize > Size) {
107		Size = DefaultSize;
108	}
109
110	return Size;
111}
112
113uint64 EbmlSInteger::ReadData(IOCallback & input, ScopeMode ReadFully)
114{
115	if (ReadFully != SCOPE_NO_DATA)
116	{
117		binary Buffer[8];
118		input.readFully(Buffer, Size);
119
120		if (Buffer[0] & 0x80)
121			Value = -1; // this is a negative value
122		else
123			Value = 0; // this is a positive value
124
125		for (unsigned int i=0; i<Size; i++)
126		{
127			Value <<= 8;
128			Value |= Buffer[i];
129		}
130		bValueIsSet = true;
131	}
132
133	return Size;
134}
135
136END_LIBEBML_NAMESPACE
137