tbzcompress.c - plan9port - [fork] Plan 9 from user space
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---
tbzcompress.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 }