bzcompress.c (13944B)
1 /* 2 * THIS FILE IS NOT IDENTICAL TO THE ORIGINAL 3 * FROM THE BZIP2 DISTRIBUTION. 4 * 5 * It has been modified, mainly to break the library 6 * into smaller pieces. 7 * 8 * Russ Cox 9 * rsc@plan9.bell-labs.com 10 * July 2000 11 */ 12 13 /*-------------------------------------------------------------*/ 14 /*--- Library top-level functions. ---*/ 15 /*--- bzlib.c ---*/ 16 /*-------------------------------------------------------------*/ 17 18 /*-- 19 This file is a part of bzip2 and/or libbzip2, a program and 20 library for lossless, block-sorting data compression. 21 22 Copyright (C) 1996-2000 Julian R Seward. All rights reserved. 23 24 Redistribution and use in source and binary forms, with or without 25 modification, are permitted provided that the following conditions 26 are met: 27 28 1. Redistributions of source code must retain the above copyright 29 notice, this list of conditions and the following disclaimer. 30 31 2. The origin of this software must not be misrepresented; you must 32 not claim that you wrote the original software. If you use this 33 software in a product, an acknowledgment in the product 34 documentation would be appreciated but is not required. 35 36 3. Altered source versions must be plainly marked as such, and must 37 not be misrepresented as being the original software. 38 39 4. The name of the author may not be used to endorse or promote 40 products derived from this software without specific prior written 41 permission. 42 43 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 44 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 45 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 46 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 47 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 48 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 49 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 50 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 51 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 52 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 53 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 54 55 Julian Seward, Cambridge, UK. 56 jseward@acm.org 57 bzip2/libbzip2 version 1.0 of 21 March 2000 58 59 This program is based on (at least) the work of: 60 Mike Burrows 61 David Wheeler 62 Peter Fenwick 63 Alistair Moffat 64 Radford Neal 65 Ian H. Witten 66 Robert Sedgewick 67 Jon L. Bentley 68 69 For more information on these sources, see the manual. 70 --*/ 71 72 /*-- 73 CHANGES 74 ~~~~~~~ 75 0.9.0 -- original version. 76 77 0.9.0a/b -- no changes in this file. 78 79 0.9.0c 80 * made zero-length BZ_FLUSH work correctly in bzCompress(). 81 * fixed bzWrite/bzRead to ignore zero-length requests. 82 * fixed bzread to correctly handle read requests after EOF. 83 * wrong parameter order in call to bzDecompressInit in 84 bzBuffToBuffDecompress. Fixed. 85 --*/ 86 87 #include "os.h" 88 #include "bzlib.h" 89 #include "bzlib_private.h" 90 91 /*---------------------------------------------------*/ 92 /*--- Compression stuff ---*/ 93 /*---------------------------------------------------*/ 94 95 /*---------------------------------------------------*/ 96 static 97 void prepare_new_block ( EState* s ) 98 { 99 Int32 i; 100 s->nblock = 0; 101 s->numZ = 0; 102 s->state_out_pos = 0; 103 BZ_INITIALISE_CRC ( s->blockCRC ); 104 for (i = 0; i < 256; i++) s->inUse[i] = False; 105 s->blockNo++; 106 } 107 108 109 /*---------------------------------------------------*/ 110 static 111 void init_RL ( EState* s ) 112 { 113 s->state_in_ch = 256; 114 s->state_in_len = 0; 115 } 116 117 118 static 119 Bool isempty_RL ( EState* s ) 120 { 121 if (s->state_in_ch < 256 && s->state_in_len > 0) 122 return False; else 123 return True; 124 } 125 126 127 /*---------------------------------------------------*/ 128 int BZ_API(BZ2_bzCompressInit) 129 ( bz_stream* strm, 130 int blockSize100k, 131 int verbosity, 132 int workFactor ) 133 { 134 Int32 n; 135 EState* s; 136 137 if (!bz_config_ok()) return BZ_CONFIG_ERROR; 138 139 if (strm == NULL || 140 blockSize100k < 1 || blockSize100k > 9 || 141 workFactor < 0 || workFactor > 250) 142 return BZ_PARAM_ERROR; 143 144 if (workFactor == 0) workFactor = 30; 145 if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc; 146 if (strm->bzfree == NULL) strm->bzfree = default_bzfree; 147 148 s = BZALLOC( sizeof(EState) ); 149 if (s == NULL) return BZ_MEM_ERROR; 150 s->strm = strm; 151 152 s->arr1 = NULL; 153 s->arr2 = NULL; 154 s->ftab = NULL; 155 156 n = 100000 * blockSize100k; 157 s->arr1 = BZALLOC( n * sizeof(UInt32) ); 158 s->arr2 = BZALLOC( (n+BZ_N_OVERSHOOT) * sizeof(UInt32) ); 159 s->ftab = BZALLOC( 65537 * sizeof(UInt32) ); 160 161 if (s->arr1 == NULL || s->arr2 == NULL || s->ftab == NULL) { 162 if (s->arr1 != NULL) BZFREE(s->arr1); 163 if (s->arr2 != NULL) BZFREE(s->arr2); 164 if (s->ftab != NULL) BZFREE(s->ftab); 165 if (s != NULL) BZFREE(s); 166 return BZ_MEM_ERROR; 167 } 168 169 s->blockNo = 0; 170 s->state = BZ_S_INPUT; 171 s->mode = BZ_M_RUNNING; 172 s->combinedCRC = 0; 173 s->blockSize100k = blockSize100k; 174 s->nblockMAX = 100000 * blockSize100k - 19; 175 s->verbosity = verbosity; 176 s->workFactor = workFactor; 177 178 s->block = (UChar*)s->arr2; 179 s->mtfv = (UInt16*)s->arr1; 180 s->zbits = NULL; 181 s->ptr = (UInt32*)s->arr1; 182 183 strm->state = s; 184 strm->total_in_lo32 = 0; 185 strm->total_in_hi32 = 0; 186 strm->total_out_lo32 = 0; 187 strm->total_out_hi32 = 0; 188 init_RL ( s ); 189 prepare_new_block ( s ); 190 return BZ_OK; 191 } 192 193 194 /*---------------------------------------------------*/ 195 static 196 void add_pair_to_block ( EState* s ) 197 { 198 Int32 i; 199 UChar ch = (UChar)(s->state_in_ch); 200 for (i = 0; i < s->state_in_len; i++) { 201 BZ_UPDATE_CRC( s->blockCRC, ch ); 202 } 203 s->inUse[s->state_in_ch] = True; 204 switch (s->state_in_len) { 205 case 1: 206 s->block[s->nblock] = (UChar)ch; s->nblock++; 207 break; 208 case 2: 209 s->block[s->nblock] = (UChar)ch; s->nblock++; 210 s->block[s->nblock] = (UChar)ch; s->nblock++; 211 break; 212 case 3: 213 s->block[s->nblock] = (UChar)ch; s->nblock++; 214 s->block[s->nblock] = (UChar)ch; s->nblock++; 215 s->block[s->nblock] = (UChar)ch; s->nblock++; 216 break; 217 default: 218 s->inUse[s->state_in_len-4] = True; 219 s->block[s->nblock] = (UChar)ch; s->nblock++; 220 s->block[s->nblock] = (UChar)ch; s->nblock++; 221 s->block[s->nblock] = (UChar)ch; s->nblock++; 222 s->block[s->nblock] = (UChar)ch; s->nblock++; 223 s->block[s->nblock] = ((UChar)(s->state_in_len-4)); 224 s->nblock++; 225 break; 226 } 227 } 228 229 230 /*---------------------------------------------------*/ 231 static 232 void flush_RL ( EState* s ) 233 { 234 if (s->state_in_ch < 256) add_pair_to_block ( s ); 235 init_RL ( s ); 236 } 237 238 239 /*---------------------------------------------------*/ 240 #define ADD_CHAR_TO_BLOCK(zs,zchh0) \ 241 { \ 242 UInt32 zchh = (UInt32)(zchh0); \ 243 /*-- fast track the common case --*/ \ 244 if (zchh != zs->state_in_ch && \ 245 zs->state_in_len == 1) { \ 246 UChar ch = (UChar)(zs->state_in_ch); \ 247 BZ_UPDATE_CRC( zs->blockCRC, ch ); \ 248 zs->inUse[zs->state_in_ch] = True; \ 249 zs->block[zs->nblock] = (UChar)ch; \ 250 zs->nblock++; \ 251 zs->state_in_ch = zchh; \ 252 } \ 253 else \ 254 /*-- general, uncommon cases --*/ \ 255 if (zchh != zs->state_in_ch || \ 256 zs->state_in_len == 255) { \ 257 if (zs->state_in_ch < 256) \ 258 add_pair_to_block ( zs ); \ 259 zs->state_in_ch = zchh; \ 260 zs->state_in_len = 1; \ 261 } else { \ 262 zs->state_in_len++; \ 263 } \ 264 } 265 266 267 /*---------------------------------------------------*/ 268 static 269 Bool copy_input_until_stop ( EState* s ) 270 { 271 Bool progress_in = False; 272 273 if (s->mode == BZ_M_RUNNING) { 274 275 /*-- fast track the common case --*/ 276 while (True) { 277 /*-- block full? --*/ 278 if (s->nblock >= s->nblockMAX) break; 279 /*-- no input? --*/ 280 if (s->strm->avail_in == 0) break; 281 progress_in = True; 282 ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 283 s->strm->next_in++; 284 s->strm->avail_in--; 285 s->strm->total_in_lo32++; 286 if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++; 287 } 288 289 } else { 290 291 /*-- general, uncommon case --*/ 292 while (True) { 293 /*-- block full? --*/ 294 if (s->nblock >= s->nblockMAX) break; 295 /*-- no input? --*/ 296 if (s->strm->avail_in == 0) break; 297 /*-- flush/finish end? --*/ 298 if (s->avail_in_expect == 0) break; 299 progress_in = True; 300 ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 301 s->strm->next_in++; 302 s->strm->avail_in--; 303 s->strm->total_in_lo32++; 304 if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++; 305 s->avail_in_expect--; 306 } 307 } 308 return progress_in; 309 } 310 311 312 /*---------------------------------------------------*/ 313 static 314 Bool copy_output_until_stop ( EState* s ) 315 { 316 Bool progress_out = False; 317 318 while (True) { 319 320 /*-- no output space? --*/ 321 if (s->strm->avail_out == 0) break; 322 323 /*-- block done? --*/ 324 if (s->state_out_pos >= s->numZ) break; 325 326 progress_out = True; 327 *(s->strm->next_out) = s->zbits[s->state_out_pos]; 328 s->state_out_pos++; 329 s->strm->avail_out--; 330 s->strm->next_out++; 331 s->strm->total_out_lo32++; 332 if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++; 333 } 334 335 return progress_out; 336 } 337 338 339 /*---------------------------------------------------*/ 340 static 341 Bool handle_compress ( bz_stream* strm ) 342 { 343 Bool progress_in = False; 344 Bool progress_out = False; 345 EState* s = strm->state; 346 347 while (True) { 348 349 if (s->state == BZ_S_OUTPUT) { 350 progress_out |= copy_output_until_stop ( s ); 351 if (s->state_out_pos < s->numZ) break; 352 if (s->mode == BZ_M_FINISHING && 353 s->avail_in_expect == 0 && 354 isempty_RL(s)) break; 355 prepare_new_block ( s ); 356 s->state = BZ_S_INPUT; 357 if (s->mode == BZ_M_FLUSHING && 358 s->avail_in_expect == 0 && 359 isempty_RL(s)) break; 360 } 361 362 if (s->state == BZ_S_INPUT) { 363 progress_in |= copy_input_until_stop ( s ); 364 if (s->mode != BZ_M_RUNNING && s->avail_in_expect == 0) { 365 flush_RL ( s ); 366 BZ2_compressBlock ( s, (Bool)(s->mode == BZ_M_FINISHING) ); 367 s->state = BZ_S_OUTPUT; 368 } 369 else 370 if (s->nblock >= s->nblockMAX) { 371 BZ2_compressBlock ( s, False ); 372 s->state = BZ_S_OUTPUT; 373 } 374 else 375 if (s->strm->avail_in == 0) { 376 break; 377 } 378 } 379 380 } 381 382 return progress_in || progress_out; 383 } 384 385 /*---------------------------------------------------*/ 386 int BZ_API(BZ2_bzCompress) ( bz_stream *strm, int action ) 387 { 388 Bool progress; 389 EState* s; 390 if (strm == NULL) return BZ_PARAM_ERROR; 391 s = strm->state; 392 if (s == NULL) return BZ_PARAM_ERROR; 393 if (s->strm != strm) return BZ_PARAM_ERROR; 394 395 preswitch: 396 switch (s->mode) { 397 398 case BZ_M_IDLE: 399 return BZ_SEQUENCE_ERROR; 400 401 case BZ_M_RUNNING: 402 if (action == BZ_RUN) { 403 progress = handle_compress ( strm ); 404 return progress ? BZ_RUN_OK : BZ_PARAM_ERROR; 405 } 406 else 407 if (action == BZ_FLUSH) { 408 s->avail_in_expect = strm->avail_in; 409 s->mode = BZ_M_FLUSHING; 410 goto preswitch; 411 } 412 else 413 if (action == BZ_FINISH) { 414 s->avail_in_expect = strm->avail_in; 415 s->mode = BZ_M_FINISHING; 416 goto preswitch; 417 } 418 else 419 return BZ_PARAM_ERROR; 420 421 case BZ_M_FLUSHING: 422 if (action != BZ_FLUSH) return BZ_SEQUENCE_ERROR; 423 if (s->avail_in_expect != s->strm->avail_in) 424 return BZ_SEQUENCE_ERROR; 425 progress = handle_compress ( strm ); 426 if (!progress) return BZ_SEQUENCE_ERROR; /*rsc added */ 427 if (s->avail_in_expect > 0 || !isempty_RL(s) || 428 s->state_out_pos < s->numZ) return BZ_FLUSH_OK; 429 s->mode = BZ_M_RUNNING; 430 return BZ_RUN_OK; 431 432 case BZ_M_FINISHING: 433 if (action != BZ_FINISH) return BZ_SEQUENCE_ERROR; 434 if (s->avail_in_expect != s->strm->avail_in) 435 return BZ_SEQUENCE_ERROR; 436 progress = handle_compress ( strm ); 437 if (!progress) return BZ_SEQUENCE_ERROR; 438 if (s->avail_in_expect > 0 || !isempty_RL(s) || 439 s->state_out_pos < s->numZ) return BZ_FINISH_OK; 440 s->mode = BZ_M_IDLE; 441 return BZ_STREAM_END; 442 } 443 return BZ_OK; /*--not reached--*/ 444 } 445 446 447 /*---------------------------------------------------*/ 448 int BZ_API(BZ2_bzCompressEnd) ( bz_stream *strm ) 449 { 450 EState* s; 451 if (strm == NULL) return BZ_PARAM_ERROR; 452 s = strm->state; 453 if (s == NULL) return BZ_PARAM_ERROR; 454 if (s->strm != strm) return BZ_PARAM_ERROR; 455 456 if (s->arr1 != NULL) BZFREE(s->arr1); 457 if (s->arr2 != NULL) BZFREE(s->arr2); 458 if (s->ftab != NULL) BZFREE(s->ftab); 459 BZFREE(strm->state); 460 461 strm->state = NULL; 462 463 return BZ_OK; 464 }