2 * THIS FILE IS NOT IDENTICAL TO THE ORIGINAL
3 * FROM THE BZIP2 DISTRIBUTION.
5 * It has been modified, mainly to break the library
9 * rsc@plan9.bell-labs.com
13 /*-------------------------------------------------------------*/
14 /*--- Library top-level functions. ---*/
16 /*-------------------------------------------------------------*/
19 This file is a part of bzip2 and/or libbzip2, a program and
20 library for lossless, block-sorting data compression.
22 Copyright (C) 1996-2000 Julian R Seward. All rights reserved.
24 Redistribution and use in source and binary forms, with or without
25 modification, are permitted provided that the following conditions
28 1. Redistributions of source code must retain the above copyright
29 notice, this list of conditions and the following disclaimer.
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.
36 3. Altered source versions must be plainly marked as such, and must
37 not be misrepresented as being the original software.
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
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.
55 Julian Seward, Cambridge, UK.
57 bzip2/libbzip2 version 1.0 of 21 March 2000
59 This program is based on (at least) the work of:
69 For more information on these sources, see the manual.
75 0.9.0 -- original version.
77 0.9.0a/b -- no changes in this file.
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.
89 #include "bzlib_private.h"
91 /*---------------------------------------------------*/
92 /*--- Decompression stuff ---*/
93 /*---------------------------------------------------*/
95 /*---------------------------------------------------*/
96 int BZ_API(BZ2_bzDecompressInit)
103 if (!bz_config_ok()) return BZ_CONFIG_ERROR;
105 if (strm == NULL) return BZ_PARAM_ERROR;
106 if (small != 0 && small != 1) return BZ_PARAM_ERROR;
107 if (verbosity < 0 || verbosity > 4) return BZ_PARAM_ERROR;
109 if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc;
110 if (strm->bzfree == NULL) strm->bzfree = default_bzfree;
112 s = BZALLOC( sizeof(DState) );
113 if (s == NULL) return BZ_MEM_ERROR;
116 s->state = BZ_X_MAGIC_1;
119 s->calculatedCombinedCRC = 0;
120 strm->total_in_lo32 = 0;
121 strm->total_in_hi32 = 0;
122 strm->total_out_lo32 = 0;
123 strm->total_out_hi32 = 0;
124 s->smallDecompress = (Bool)small;
129 s->verbosity = verbosity;
135 /*---------------------------------------------------*/
137 void unRLE_obuf_to_output_FAST ( DState* s )
141 if (s->blockRandomised) {
144 /* try to finish existing run */
146 if (s->strm->avail_out == 0) return;
147 if (s->state_out_len == 0) break;
148 *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
149 BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
152 s->strm->avail_out--;
153 s->strm->total_out_lo32++;
154 if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
157 /* can a new run be started? */
158 if (s->nblock_used == s->save_nblock+1) return;
161 s->state_out_len = 1;
162 s->state_out_ch = s->k0;
163 BZ_GET_FAST(k1); BZ_RAND_UPD_MASK;
164 k1 ^= BZ_RAND_MASK; s->nblock_used++;
165 if (s->nblock_used == s->save_nblock+1) continue;
166 if (k1 != s->k0) { s->k0 = k1; continue; };
168 s->state_out_len = 2;
169 BZ_GET_FAST(k1); BZ_RAND_UPD_MASK;
170 k1 ^= BZ_RAND_MASK; s->nblock_used++;
171 if (s->nblock_used == s->save_nblock+1) continue;
172 if (k1 != s->k0) { s->k0 = k1; continue; };
174 s->state_out_len = 3;
175 BZ_GET_FAST(k1); BZ_RAND_UPD_MASK;
176 k1 ^= BZ_RAND_MASK; s->nblock_used++;
177 if (s->nblock_used == s->save_nblock+1) continue;
178 if (k1 != s->k0) { s->k0 = k1; continue; };
180 BZ_GET_FAST(k1); BZ_RAND_UPD_MASK;
181 k1 ^= BZ_RAND_MASK; s->nblock_used++;
182 s->state_out_len = ((Int32)k1) + 4;
183 BZ_GET_FAST(s->k0); BZ_RAND_UPD_MASK;
184 s->k0 ^= BZ_RAND_MASK; s->nblock_used++;
190 UInt32 c_calculatedBlockCRC = s->calculatedBlockCRC;
191 UChar c_state_out_ch = s->state_out_ch;
192 Int32 c_state_out_len = s->state_out_len;
193 Int32 c_nblock_used = s->nblock_used;
195 UInt32* c_tt = s->tt;
196 UInt32 c_tPos = s->tPos;
197 char* cs_next_out = s->strm->next_out;
198 unsigned int cs_avail_out = s->strm->avail_out;
201 UInt32 avail_out_INIT = cs_avail_out;
202 Int32 s_save_nblockPP = s->save_nblock+1;
203 unsigned int total_out_lo32_old;
207 /* try to finish existing run */
208 if (c_state_out_len > 0) {
210 if (cs_avail_out == 0) goto return_notr;
211 if (c_state_out_len == 1) break;
212 *( (UChar*)(cs_next_out) ) = c_state_out_ch;
213 BZ_UPDATE_CRC ( c_calculatedBlockCRC, c_state_out_ch );
218 s_state_out_len_eq_one:
220 if (cs_avail_out == 0) {
221 c_state_out_len = 1; goto return_notr;
223 *( (UChar*)(cs_next_out) ) = c_state_out_ch;
224 BZ_UPDATE_CRC ( c_calculatedBlockCRC, c_state_out_ch );
229 /* can a new run be started? */
230 if (c_nblock_used == s_save_nblockPP) {
231 c_state_out_len = 0; goto return_notr;
233 c_state_out_ch = c_k0;
234 BZ_GET_FAST_C(k1); c_nblock_used++;
236 c_k0 = k1; goto s_state_out_len_eq_one;
238 if (c_nblock_used == s_save_nblockPP)
239 goto s_state_out_len_eq_one;
242 BZ_GET_FAST_C(k1); c_nblock_used++;
243 if (c_nblock_used == s_save_nblockPP) continue;
244 if (k1 != c_k0) { c_k0 = k1; continue; };
247 BZ_GET_FAST_C(k1); c_nblock_used++;
248 if (c_nblock_used == s_save_nblockPP) continue;
249 if (k1 != c_k0) { c_k0 = k1; continue; };
251 BZ_GET_FAST_C(k1); c_nblock_used++;
252 c_state_out_len = ((Int32)k1) + 4;
253 BZ_GET_FAST_C(c_k0); c_nblock_used++;
257 total_out_lo32_old = s->strm->total_out_lo32;
258 s->strm->total_out_lo32 += (avail_out_INIT - cs_avail_out);
259 if (s->strm->total_out_lo32 < total_out_lo32_old)
260 s->strm->total_out_hi32++;
263 s->calculatedBlockCRC = c_calculatedBlockCRC;
264 s->state_out_ch = c_state_out_ch;
265 s->state_out_len = c_state_out_len;
266 s->nblock_used = c_nblock_used;
270 s->strm->next_out = cs_next_out;
271 s->strm->avail_out = cs_avail_out;
278 /*---------------------------------------------------*/
279 __inline__ Int32 BZ2_indexIntoF ( Int32 indx, Int32 *cftab )
285 mid = (nb + na) >> 1;
286 if (indx >= cftab[mid]) nb = mid; else na = mid;
288 while (na - nb != 1);
293 /*---------------------------------------------------*/
295 void unRLE_obuf_to_output_SMALL ( DState* s )
299 if (s->blockRandomised) {
302 /* try to finish existing run */
304 if (s->strm->avail_out == 0) return;
305 if (s->state_out_len == 0) break;
306 *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
307 BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
310 s->strm->avail_out--;
311 s->strm->total_out_lo32++;
312 if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
315 /* can a new run be started? */
316 if (s->nblock_used == s->save_nblock+1) return;
319 s->state_out_len = 1;
320 s->state_out_ch = s->k0;
321 BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK;
322 k1 ^= BZ_RAND_MASK; s->nblock_used++;
323 if (s->nblock_used == s->save_nblock+1) continue;
324 if (k1 != s->k0) { s->k0 = k1; continue; };
326 s->state_out_len = 2;
327 BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK;
328 k1 ^= BZ_RAND_MASK; s->nblock_used++;
329 if (s->nblock_used == s->save_nblock+1) continue;
330 if (k1 != s->k0) { s->k0 = k1; continue; };
332 s->state_out_len = 3;
333 BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK;
334 k1 ^= BZ_RAND_MASK; s->nblock_used++;
335 if (s->nblock_used == s->save_nblock+1) continue;
336 if (k1 != s->k0) { s->k0 = k1; continue; };
338 BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK;
339 k1 ^= BZ_RAND_MASK; s->nblock_used++;
340 s->state_out_len = ((Int32)k1) + 4;
341 BZ_GET_SMALL(s->k0); BZ_RAND_UPD_MASK;
342 s->k0 ^= BZ_RAND_MASK; s->nblock_used++;
348 /* try to finish existing run */
350 if (s->strm->avail_out == 0) return;
351 if (s->state_out_len == 0) break;
352 *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
353 BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
356 s->strm->avail_out--;
357 s->strm->total_out_lo32++;
358 if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
361 /* can a new run be started? */
362 if (s->nblock_used == s->save_nblock+1) return;
364 s->state_out_len = 1;
365 s->state_out_ch = s->k0;
366 BZ_GET_SMALL(k1); s->nblock_used++;
367 if (s->nblock_used == s->save_nblock+1) continue;
368 if (k1 != s->k0) { s->k0 = k1; continue; };
370 s->state_out_len = 2;
371 BZ_GET_SMALL(k1); s->nblock_used++;
372 if (s->nblock_used == s->save_nblock+1) continue;
373 if (k1 != s->k0) { s->k0 = k1; continue; };
375 s->state_out_len = 3;
376 BZ_GET_SMALL(k1); s->nblock_used++;
377 if (s->nblock_used == s->save_nblock+1) continue;
378 if (k1 != s->k0) { s->k0 = k1; continue; };
380 BZ_GET_SMALL(k1); s->nblock_used++;
381 s->state_out_len = ((Int32)k1) + 4;
382 BZ_GET_SMALL(s->k0); s->nblock_used++;
389 /*---------------------------------------------------*/
390 int BZ_API(BZ2_bzDecompress) ( bz_stream *strm )
393 if (strm == NULL) return BZ_PARAM_ERROR;
395 if (s == NULL) return BZ_PARAM_ERROR;
396 if (s->strm != strm) return BZ_PARAM_ERROR;
399 if (s->state == BZ_X_IDLE) return BZ_SEQUENCE_ERROR;
400 if (s->state == BZ_X_OUTPUT) {
401 if (s->smallDecompress)
402 unRLE_obuf_to_output_SMALL ( s ); else
403 unRLE_obuf_to_output_FAST ( s );
404 if (s->nblock_used == s->save_nblock+1 && s->state_out_len == 0) {
405 BZ_FINALISE_CRC ( s->calculatedBlockCRC );
406 if (s->verbosity >= 3)
407 VPrintf2 ( " {0x%x, 0x%x}", s->storedBlockCRC,
408 s->calculatedBlockCRC );
409 if (s->verbosity >= 2) VPrintf0 ( "]" );
410 if (s->calculatedBlockCRC != s->storedBlockCRC)
411 return BZ_DATA_ERROR;
412 s->calculatedCombinedCRC
413 = (s->calculatedCombinedCRC << 1) |
414 (s->calculatedCombinedCRC >> 31);
415 s->calculatedCombinedCRC ^= s->calculatedBlockCRC;
416 s->state = BZ_X_BLKHDR_1;
421 if (s->state >= BZ_X_MAGIC_1) {
422 Int32 r = BZ2_decompress ( s );
423 if (r == BZ_STREAM_END) {
424 if (s->verbosity >= 3)
425 VPrintf2 ( "\n combined CRCs: stored = 0x%x, computed = 0x%x",
426 s->storedCombinedCRC, s->calculatedCombinedCRC );
427 if (s->calculatedCombinedCRC != s->storedCombinedCRC)
428 return BZ_DATA_ERROR;
431 if (s->state != BZ_X_OUTPUT) return r;
437 return 0; /*NOTREACHED*/
441 /*---------------------------------------------------*/
442 int BZ_API(BZ2_bzDecompressEnd) ( bz_stream *strm )
445 if (strm == NULL) return BZ_PARAM_ERROR;
447 if (s == NULL) return BZ_PARAM_ERROR;
448 if (s->strm != strm) return BZ_PARAM_ERROR;
450 if (s->tt != NULL) BZFREE(s->tt);
451 if (s->ll16 != NULL) BZFREE(s->ll16);
452 if (s->ll4 != NULL) BZFREE(s->ll4);