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
|
/* Lzip - A data compressor based on the LZMA algorithm
Copyright (C) 2008, 2009 Antonio Diaz Diaz.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _FILE_OFFSET_BITS 64
#include <algorithm>
#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include "lzip.h"
#include "decoder.h"
const CRC32 crc32;
bool Input_buffer::read_block()
{
if( at_stream_end ) return false;
stream_pos = readblock( ides_, (char *)buffer, buffer_size );
if( stream_pos != buffer_size && errno ) throw Error( "read error" );
pos = 0;
at_stream_end = ( stream_pos < buffer_size );
return !finished();
}
void LZ_decoder::flush_data()
{
const int size = pos - stream_pos;
if( size > 0 )
{
crc32.update( crc_, buffer + stream_pos, size );
if( odes_ >= 0 &&
writeblock( odes_, (char *)buffer + stream_pos, size ) != size )
throw Error( "write error" );
if( pos >= buffer_size ) { partial_data_pos += pos; pos = 0; }
stream_pos = pos;
}
}
bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const
{
bool error = false;
File_trailer trailer;
const int trailer_size = trailer.size( format_version );
for( int i = 0; i < trailer_size && !error; ++i )
{
if( !range_decoder.finished() )
((uint8_t *)&trailer)[i] = range_decoder.get_byte();
else
{
error = true;
if( verbosity >= 0 )
{
pp();
std::fprintf( stderr, "trailer truncated at trailer position %d;"
" some checks may fail.\n", i );
}
}
}
if( format_version == 0 ) trailer.member_size( member_position() );
if( trailer.data_crc() != crc() )
{
error = true;
if( verbosity >= 0 )
{
pp();
std::fprintf( stderr, "crc mismatch; trailer says %08X, data crc is %08X.\n",
trailer.data_crc(), crc() );
}
}
if( trailer.data_size() != data_position() )
{
error = true;
if( verbosity >= 0 )
{
if( trailer.data_size() >= 0 )
{ pp();
std::fprintf( stderr, "data size mismatch; trailer says %lld, data size is %lld.\n",
trailer.data_size(), data_position() ); }
else pp( "member trailer is corrupt" );
}
}
if( trailer.member_size() != member_position() )
{
error = true;
if( verbosity >= 0 )
{
if( trailer.member_size() >= 0 )
{ pp();
std::fprintf( stderr, "member size mismatch; trailer says %lld, member size is %lld.\n",
trailer.member_size(), member_position() ); }
else pp( "member trailer is corrupt" );
}
}
if( !error && verbosity >= 3 )
std::fprintf( stderr, "data crc %08X, data size %8lld, member size %8lld. ",
trailer.data_crc(), trailer.data_size(), trailer.member_size() );
return !error;
}
// Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
// 3 = trailer error, 4 = unknown marker found.
int LZ_decoder::decode_member( const Pretty_print & pp )
{
unsigned int rep0 = 0;
unsigned int rep1 = 0;
unsigned int rep2 = 0;
unsigned int rep3 = 0;
State state;
uint8_t prev_byte = 0;
while( true )
{
if( range_decoder.finished() ) { flush_data(); return 2; }
const int pos_state = data_position() & pos_state_mask;
if( range_decoder.decode_bit( bm_match[state()][pos_state] ) == 0 )
{
if( state.is_char() )
prev_byte = literal_decoder.decode( range_decoder, prev_byte );
else
prev_byte = literal_decoder.decode_matched( range_decoder, prev_byte,
get_byte( rep0 ) );
put_byte( prev_byte );
state.set_char();
}
else
{
int len;
if( range_decoder.decode_bit( bm_rep[state()] ) == 1 )
{
len = 0;
if( range_decoder.decode_bit( bm_rep0[state()] ) == 0 )
{
if( range_decoder.decode_bit( bm_len[state()][pos_state] ) == 0 )
{ len = 1; state.set_short_rep(); }
}
else
{
unsigned int distance;
if( range_decoder.decode_bit( bm_rep1[state()] ) == 0 )
distance = rep1;
else
{
if( range_decoder.decode_bit( bm_rep2[state()] ) == 0 )
distance = rep2;
else { distance = rep3; rep3 = rep2; }
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
if( len == 0 )
{
len = min_match_len + rep_match_len_decoder.decode( range_decoder, pos_state );
state.set_rep();
}
}
else
{
unsigned int rep0_saved = rep0;
len = min_match_len + len_decoder.decode( range_decoder, pos_state );
const int dis_slot = range_decoder.decode_tree( bm_dis_slot[get_dis_state(len)], dis_slot_bits );
if( dis_slot < start_dis_model ) rep0 = dis_slot;
else
{
const int direct_bits = ( dis_slot >> 1 ) - 1;
rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
if( dis_slot < end_dis_model )
rep0 += range_decoder.decode_tree_reversed( bm_dis + rep0 - dis_slot, direct_bits );
else
{
rep0 += range_decoder.decode( direct_bits - dis_align_bits ) << dis_align_bits;
rep0 += range_decoder.decode_tree_reversed( bm_align, dis_align_bits );
if( rep0 == 0xFFFFFFFF ) // Marker found
{
rep0 = rep0_saved;
range_decoder.normalize();
flush_data();
if( len == min_match_len ) // End Of Stream marker
{
if( verify_trailer( pp ) ) return 0; else return 3;
}
if( len == min_match_len + 1 ) // Sync Flush marker
{
range_decoder.reload(); continue;
}
if( verbosity >= 0 )
{
pp();
std::fprintf( stderr, "unsupported marker code `%d'.\n", len );
}
return 4;
}
if( rep0 >= (unsigned int)dictionary_size )
{ flush_data(); return 1; }
}
}
rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
state.set_match();
}
copy_block( rep0, len );
prev_byte = get_byte( 0 );
}
}
}
|
