summaryrefslogtreecommitdiffstats
path: root/lzip.h
blob: c5915b1bc173cfc514a1e953d5669b0ccad4c1a7 (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
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
/*  Lzip - LZMA lossless data compressor
    Copyright (C) 2008-2017 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 2 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/>.
*/

class State
  {
  int st;

public:
  enum { states = 12 };
  State() : st( 0 ) {}
  int operator()() const { return st; }
  bool is_char() const { return st < 7; }

  void set_char()
    {
    static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
    st = next[st];
    }
  bool is_char_set_char()
    {
    if( st < 7 ) { st -= ( st < 4 ) ? st : 3; return true; }
    else { st -= ( st < 10 ) ? 3 : 6; return false; }
    }
  void set_char_rep()  { st = 8; }
  void set_match()     { st = ( st < 7 ) ? 7 : 10; }
  void set_rep()       { st = ( st < 7 ) ? 8 : 11; }
  void set_short_rep() { st = ( st < 7 ) ? 9 : 11; }
  };


enum {
  min_dictionary_bits = 12,
  min_dictionary_size = 1 << min_dictionary_bits,	// >= modeled_distances
  max_dictionary_bits = 29,
  max_dictionary_size = 1 << max_dictionary_bits,
  min_member_size = 36,
  literal_context_bits = 3,
  literal_pos_state_bits = 0,				// not used
  pos_state_bits = 2,
  pos_states = 1 << pos_state_bits,
  pos_state_mask = pos_states - 1,

  len_states = 4,
  dis_slot_bits = 6,
  start_dis_model = 4,
  end_dis_model = 14,
  modeled_distances = 1 << (end_dis_model / 2),		// 128
  dis_align_bits = 4,
  dis_align_size = 1 << dis_align_bits,

  len_low_bits = 3,
  len_mid_bits = 3,
  len_high_bits = 8,
  len_low_symbols = 1 << len_low_bits,
  len_mid_symbols = 1 << len_mid_bits,
  len_high_symbols = 1 << len_high_bits,
  max_len_symbols = len_low_symbols + len_mid_symbols + len_high_symbols,

  min_match_len = 2,					// must be 2
  max_match_len = min_match_len + max_len_symbols - 1,	// 273
  min_match_len_limit = 5 };

inline int get_len_state( const int len )
  { return std::min( len - min_match_len, len_states - 1 ); }

inline int get_lit_state( const uint8_t prev_byte )
  { return ( prev_byte >> ( 8 - literal_context_bits ) ); }


enum { bit_model_move_bits = 5,
       bit_model_total_bits = 11,
       bit_model_total = 1 << bit_model_total_bits };

struct Bit_model
  {
  int probability;
  void reset() { probability = bit_model_total / 2; }
  void reset( const int size )
    { for( int i = 0; i < size; ++i ) this[i].reset(); }
  Bit_model() { reset(); }
  };

struct Len_model
  {
  Bit_model choice1;
  Bit_model choice2;
  Bit_model bm_low[pos_states][len_low_symbols];
  Bit_model bm_mid[pos_states][len_mid_symbols];
  Bit_model bm_high[len_high_symbols];

  void reset()
    {
    choice1.reset();
    choice2.reset();
    bm_low[0][0].reset( pos_states * len_low_symbols );
    bm_mid[0][0].reset( pos_states * len_mid_symbols );
    bm_high[0].reset( len_high_symbols );
    }
  };


class Pretty_print
  {
  std::string name_;
  const char * const stdin_name;
  unsigned longest_name;
  mutable bool first_post;

public:
  Pretty_print( const std::vector< std::string > & filenames,
                const int verbosity )
    : stdin_name( "(stdin)" ), longest_name( 0 ), first_post( false )
    {
    if( verbosity <= 0 ) return;
    const unsigned stdin_name_len = std::strlen( stdin_name );
    for( unsigned i = 0; i < filenames.size(); ++i )
      {
      const std::string & s = filenames[i];
      const unsigned len = ( s == "-" ) ? stdin_name_len : s.size();
      if( len > longest_name ) longest_name = len;
      }
    if( longest_name == 0 ) longest_name = stdin_name_len;
    }

  void set_name( const std::string & filename )
    {
    if( filename.size() && filename != "-" ) name_ = filename;
    else name_ = stdin_name;
    first_post = true;
    }

  void reset() const { if( name_.size() ) first_post = true; }
  const char * name() const { return name_.c_str(); }
  void operator()( const char * const msg = 0 ) const;
  };


class CRC32
  {
  uint32_t data[256];		// Table of CRCs of all 8-bit messages.

public:
  CRC32()
    {
    for( unsigned n = 0; n < 256; ++n )
      {
      unsigned c = n;
      for( int k = 0; k < 8; ++k )
        { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; }
      data[n] = c;
      }
    }

  uint32_t operator[]( const uint8_t byte ) const { return data[byte]; }

  void update_byte( uint32_t & crc, const uint8_t byte ) const
    { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); }

  void update_buf( uint32_t & crc, const uint8_t * const buffer,
                   const int size ) const
    {
    uint32_t c = crc;
    for( int i = 0; i < size; ++i )
      c = data[(c^buffer[i])&0xFF] ^ ( c >> 8 );
    crc = c;
    }
  };

extern const CRC32 crc32;


inline bool isvalid_ds( const unsigned dictionary_size )
  { return ( dictionary_size >= min_dictionary_size &&
             dictionary_size <= max_dictionary_size ); }


inline int real_bits( unsigned value )
  {
  int bits = 0;
  while( value > 0 ) { value >>= 1; ++bits; }
  return bits;
  }


const uint8_t magic_string[4] = { 0x4C, 0x5A, 0x49, 0x50 };	// "LZIP"

struct File_header
  {
  uint8_t data[6];			// 0-3 magic bytes
					//   4 version
					//   5 coded_dict_size
  enum { size = 6 };

  void set_magic() { std::memcpy( data, magic_string, 4 ); data[4] = 1; }
  bool verify_magic() const
    { return ( std::memcmp( data, magic_string, 4 ) == 0 ); }
  bool verify_prefix( const int size ) const	// detect truncated header
    {
    for( int i = 0; i < size && i < 4; ++i )
      if( data[i] != magic_string[i] ) return false;
    return ( size > 0 );
    }

  uint8_t version() const { return data[4]; }
  bool verify_version() const { return ( data[4] == 1 ); }

  unsigned dictionary_size() const
    {
    unsigned sz = ( 1 << ( data[5] & 0x1F ) );
    if( sz > min_dictionary_size )
      sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 7 );
    return sz;
    }

  bool dictionary_size( const unsigned sz )
    {
    if( !isvalid_ds( sz ) ) return false;
    data[5] = real_bits( sz - 1 );
    if( sz > min_dictionary_size )
      {
      const unsigned base_size = 1 << data[5];
      const unsigned fraction = base_size / 16;
      for( unsigned i = 7; i >= 1; --i )
        if( base_size - ( i * fraction ) >= sz )
          { data[5] |= ( i << 5 ); break; }
      }
    return true;
    }
  };


struct File_trailer
  {
  uint8_t data[20];	//  0-3  CRC32 of the uncompressed data
			//  4-11 size of the uncompressed data
			// 12-19 member size including header and trailer

  enum { size = 20 };

  unsigned data_crc() const
    {
    unsigned tmp = 0;
    for( int i = 3; i >= 0; --i ) { tmp <<= 8; tmp += data[i]; }
    return tmp;
    }

  void data_crc( unsigned crc )
    { for( int i = 0; i <= 3; ++i ) { data[i] = (uint8_t)crc; crc >>= 8; } }

  unsigned long long data_size() const
    {
    unsigned long long tmp = 0;
    for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; }
    return tmp;
    }

  void data_size( unsigned long long sz )
    { for( int i = 4; i <= 11; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } }

  unsigned long long member_size() const
    {
    unsigned long long tmp = 0;
    for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; }
    return tmp;
    }

  void member_size( unsigned long long sz )
    { for( int i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } }
  };


struct Error
  {
  const char * const msg;
  explicit Error( const char * const s ) : msg( s ) {}
  };


const char * const bad_magic_msg = "Bad magic number (file not in lzip format).";
const char * const bad_dict_msg = "Invalid dictionary size in member header.";
const char * const trailing_msg = "Trailing data not allowed.";

// defined in decoder.cc
int readblock( const int fd, uint8_t * const buf, const int size );
int writeblock( const int fd, const uint8_t * const buf, const int size );

// defined in list.cc
int list_files( const std::vector< std::string > & filenames,
                const bool ignore_trailing );

// defined in main.cc
extern int verbosity;
struct stat;
const char * bad_version( const unsigned version );
const char * format_ds( const unsigned dictionary_size );
int open_instream( const char * const name, struct stat * const in_statsp,
                   const bool no_ofile, const bool reg_only = false );
void show_error( const char * const msg, const int errcode = 0,
                 const bool help = false );
void show_file_error( const char * const filename, const char * const msg,
                      const int errcode = 0 );
void internal_error( const char * const msg );
class Matchfinder_base;
void show_progress( const unsigned long long partial_size = 0,
                    const Matchfinder_base * const m = 0,
                    const Pretty_print * const p = 0,
                    const unsigned long long cfile_size = 0 );