summaryrefslogtreecommitdiff
path: root/src/deflate.cpp
blob: 704d17228185c9b648cb2860076bfd0431f685eb (plain)
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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
/*
 * Copyright (C) 2007-2011 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#include "bu/deflate.h"
#include "bu/trace.h"

#include <zlib.h>

#define pState ((z_stream *)prState)

using namespace Bu;

Bu::Deflate::Deflate( Bu::Stream &rNext, int nCompression, Format eFmt ) :
	Bu::Filter( rNext ),
	prState( NULL ),
	nCompression( nCompression ),
	sTotalOut( 0 ),
	eFmt( eFmt ),
	bEos( false )
{
	TRACE( nCompression );
	start();
}

Bu::Deflate::~Deflate()
{
	TRACE();
	stop();
}

void Bu::Deflate::start()
{
	TRACE();
	prState = new z_stream;
	pState->zalloc = NULL;
	pState->zfree = NULL;
	pState->opaque = NULL;
	pState->state = NULL;

	nBufSize = 64*1024;
	pBuf = new char[nBufSize];
}

Bu::size Bu::Deflate::stop()
{
	TRACE();
	if( pState && pState->state )
	{
		if( bReading )
		{
			inflateEnd( pState );
			delete[] pBuf;
			pBuf = NULL;
			delete pState;
			prState = NULL;
			return 0;
		}
		else
		{
			for(;;)
			{
				pState->next_in = NULL;
				pState->avail_in = 0;
				pState->avail_out = nBufSize;
				pState->next_out = (Bytef *)pBuf;
				int res = deflate( pState, Z_FINISH );
				if( pState->avail_out < nBufSize )
				{
					sTotalOut += rNext.write( pBuf, nBufSize-pState->avail_out );
				}
				if( res == Z_STREAM_END )
					break;
			}
			deflateEnd( pState );
			delete[] pBuf;
			pBuf = NULL;
			delete pState;
			prState = NULL;
			return sTotalOut;
		}
	}
	return 0;
}

void Bu::Deflate::zError( int code )
{
	TRACE( code );
	switch( code )
	{
		case Z_OK:
		case Z_STREAM_END:
		case Z_NEED_DICT:
			return;

		case Z_ERRNO:
			throw ExceptionBase("Deflate: Errno - %s", pState->msg );

		case Z_STREAM_ERROR:
			throw ExceptionBase("Deflate: Stream Error - %s", pState->msg );

		case Z_DATA_ERROR:
			throw ExceptionBase("Deflate: Data Error - %s", pState->msg );

		case Z_MEM_ERROR:
			throw ExceptionBase("Deflate: Mem Error - %s", pState->msg );

		case Z_BUF_ERROR:
			throw ExceptionBase("Deflate: Buf Error - %s", pState->msg );

		case Z_VERSION_ERROR:
			throw ExceptionBase("Deflate: Version Error - %s", pState->msg );

		default:
			throw ExceptionBase("Deflate: Unknown error encountered - %s.", pState->msg );
	
	}
}

Bu::size Bu::Deflate::read( void *pData, Bu::size nBytes )
{
	TRACE( pData, nBytes );
	if( nBytes  <= 0 )
		return 0;
	if( !pState->state )
	{
		bReading = true;
		if( eFmt&AutoDetect )
			inflateInit2( pState, 32+15 ); // Auto-detect, large window
		else if( eFmt == Raw )
			inflateInit2( pState, -15 ); // Raw
		else if( eFmt == Zlib )
			inflateInit2( pState, 15 ); // Zlib
		else if( eFmt == Gzip )
			inflateInit2( pState, 16+15 ); // GZip
		else
			throw Bu::ExceptionBase("Format mode for deflate read.");
		pState->next_in = (Bytef *)pBuf;
		pState->avail_in = 0;
	}
	if( bReading == false )
		throw ExceptionBase("This deflate filter is in writing mode, you can't read.");

	int nRead = 0;
	int nReadTotal = pState->total_out;
	pState->next_out = (Bytef *)pData;
	pState->avail_out = nBytes;
	for(;;)
	{
		int ret = inflate( pState, Z_NO_FLUSH );
		nReadTotal += nRead-pState->avail_out;

		if( ret == Z_STREAM_END )
		{
			bEos = true;
			if( pState->avail_in > 0 )
			{
				if( rNext.isSeekable() )
				{
					rNext.seek( -pState->avail_in );
				}
			}
			return nBytes-pState->avail_out;
		}
		if( ret != Z_BUF_ERROR )
			zError( ret );

		if( pState->avail_out )
		{
			if( pState->avail_in == 0 )
			{
				nRead = rNext.read( pBuf, nBufSize );
				if( nRead == 0 && rNext.isEos() )
				{
					throw Bu::ExceptionBase("Premature end of underlying "
							"stream found reading deflate stream.");
				}
				pState->next_in = (Bytef *)pBuf;
				pState->avail_in = nRead;
			}
		}
		else
		{
			return nBytes-pState->avail_out;
		}
	}
	return 0;
}

Bu::size Bu::Deflate::write( const void *pData, Bu::size nBytes )
{
	TRACE( pData, nBytes );
	if( nBytes  <= 0 )
		return 0;
	if( !pState->state )
	{
		bReading = false;
		int iFmt = eFmt&Gzip;
		if( iFmt == Raw )
			deflateInit2( pState, nCompression, Z_DEFLATED, -15, 9,
				Z_DEFAULT_STRATEGY );
		else if( iFmt == Zlib )
			deflateInit2( pState, nCompression, Z_DEFLATED, 15, 9,
				Z_DEFAULT_STRATEGY );
		else if( iFmt == Gzip )
			deflateInit2( pState, nCompression, Z_DEFLATED, 16+15, 9,
				Z_DEFAULT_STRATEGY );
		else
			throw Bu::ExceptionBase("Invalid format for deflate.");
	}
	if( bReading == true )
		throw ExceptionBase("This deflate filter is in reading mode, you can't write.");

	pState->next_in = (Bytef *)pData;
	pState->avail_in = nBytes;
	for(;;)
	{
		pState->avail_out = nBufSize;
		pState->next_out = (Bytef *)pBuf;

		zError( deflate( pState, Z_NO_FLUSH ) );

		if( pState->avail_out < nBufSize )
		{
			sTotalOut += rNext.write( pBuf, nBufSize-pState->avail_out );
		}
		if( pState->avail_in == 0 )
			break;
	}

	return nBytes;
}

bool Bu::Deflate::isOpen()
{
	TRACE();
	return (pState != NULL && pState->state != NULL);
}

bool Bu::Deflate::isEos()
{
	TRACE();
	return bEos;
}

Bu::size Bu::Deflate::getCompressedSize()
{
	return sTotalOut;
}