source: SVN/cambria/redboot/packages/services/compress/zlib/current/src/example.c @ 1

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1/* example.c -- usage example of the zlib compression library
2 * Copyright (C) 1995-2003 Jean-loup Gailly.
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/* @(#) $Id$ */
7
8#include <stdio.h>
9#include "zlib.h"
10
11#ifdef STDC
12#  include <string.h>
13#  include <stdlib.h>
14#else
15   extern void exit  OF((int));
16#endif
17
18#if defined(VMS) || defined(RISCOS)
19#  define TESTFILE "foo-gz"
20#else
21#  define TESTFILE "foo.gz"
22#endif
23
24#define CHECK_ERR(err, msg) { \
25    if (err != Z_OK) { \
26        fprintf(stderr, "%s error: %d\n", msg, err); \
27        exit(1); \
28    } \
29}
30
31const char hello[] = "hello, hello!";
32/* "hello world" would be more standard, but the repeated "hello"
33 * stresses the compression code better, sorry...
34 */
35
36const char dictionary[] = "hello";
37uLong dictId; /* Adler32 value of the dictionary */
38
39void test_compress      OF((Byte *compr, uLong comprLen,
40                            Byte *uncompr, uLong uncomprLen));
41void test_gzio          OF((const char *fname,
42                            Byte *uncompr, uLong uncomprLen));
43void test_deflate       OF((Byte *compr, uLong comprLen));
44void test_inflate       OF((Byte *compr, uLong comprLen,
45                            Byte *uncompr, uLong uncomprLen));
46void test_large_deflate OF((Byte *compr, uLong comprLen,
47                            Byte *uncompr, uLong uncomprLen));
48void test_large_inflate OF((Byte *compr, uLong comprLen,
49                            Byte *uncompr, uLong uncomprLen));
50void test_flush         OF((Byte *compr, uLong *comprLen));
51void test_sync          OF((Byte *compr, uLong comprLen,
52                            Byte *uncompr, uLong uncomprLen));
53void test_dict_deflate  OF((Byte *compr, uLong comprLen));
54void test_dict_inflate  OF((Byte *compr, uLong comprLen,
55                            Byte *uncompr, uLong uncomprLen));
56int  main               OF((int argc, char *argv[]));
57
58/* ===========================================================================
59 * Test compress() and uncompress()
60 */
61void test_compress(compr, comprLen, uncompr, uncomprLen)
62    Byte *compr, *uncompr;
63    uLong comprLen, uncomprLen;
64{
65    int err;
66    uLong len = (uLong)strlen(hello)+1;
67
68    err = compress(compr, &comprLen, (const Bytef*)hello, len);
69    CHECK_ERR(err, "compress");
70
71    strcpy((char*)uncompr, "garbage");
72
73    err = uncompress(uncompr, &uncomprLen, compr, comprLen);
74    CHECK_ERR(err, "uncompress");
75
76    if (strcmp((char*)uncompr, hello)) {
77        fprintf(stderr, "bad uncompress\n");
78        exit(1);
79    } else {
80        printf("uncompress(): %s\n", (char *)uncompr);
81    }
82}
83
84/* ===========================================================================
85 * Test read/write of .gz files
86 */
87void test_gzio(fname, uncompr, uncomprLen)
88    const char *fname; /* compressed file name */
89    Byte *uncompr;
90    uLong uncomprLen;
91{
92#ifdef NO_GZCOMPRESS
93    fprintf(stderr, "NO_GZCOMPRESS -- gz* functions cannot compress\n");
94#else
95    int err;
96    int len = (int)strlen(hello)+1;
97    gzFile file;
98    z_off_t pos;
99
100    file = gzopen(fname, "wb");
101    if (file == NULL) {
102        fprintf(stderr, "gzopen error\n");
103        exit(1);
104    }
105    gzputc(file, 'h');
106    if (gzputs(file, "ello") != 4) {
107        fprintf(stderr, "gzputs err: %s\n", gzerror(file, &err));
108        exit(1);
109    }
110    if (gzprintf(file, ", %s!", "hello") != 8) {
111        fprintf(stderr, "gzprintf err: %s\n", gzerror(file, &err));
112        exit(1);
113    }
114    gzseek(file, 1L, SEEK_CUR); /* add one zero byte */
115    gzclose(file);
116
117    file = gzopen(fname, "rb");
118    if (file == NULL) {
119        fprintf(stderr, "gzopen error\n");
120        exit(1);
121    }
122    strcpy((char*)uncompr, "garbage");
123
124    if (gzread(file, uncompr, (unsigned)uncomprLen) != len) {
125        fprintf(stderr, "gzread err: %s\n", gzerror(file, &err));
126        exit(1);
127    }
128    if (strcmp((char*)uncompr, hello)) {
129        fprintf(stderr, "bad gzread: %s\n", (char*)uncompr);
130        exit(1);
131    } else {
132        printf("gzread(): %s\n", (char*)uncompr);
133    }
134
135    pos = gzseek(file, -8L, SEEK_CUR);
136    if (pos != 6 || gztell(file) != pos) {
137        fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n",
138                (long)pos, (long)gztell(file));
139        exit(1);
140    }
141
142    if (gzgetc(file) != ' ') {
143        fprintf(stderr, "gzgetc error\n");
144        exit(1);
145    }
146
147    if (gzungetc(' ', file) != ' ') {
148        fprintf(stderr, "gzungetc error\n");
149        exit(1);
150    }
151
152    gzgets(file, (char*)uncompr, (int)uncomprLen);
153    if (strlen((char*)uncompr) != 7) { /* " hello!" */
154        fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err));
155        exit(1);
156    }
157    if (strcmp((char*)uncompr, hello + 6)) {
158        fprintf(stderr, "bad gzgets after gzseek\n");
159        exit(1);
160    } else {
161        printf("gzgets() after gzseek: %s\n", (char*)uncompr);
162    }
163
164    gzclose(file);
165#endif
166}
167
168/* ===========================================================================
169 * Test deflate() with small buffers
170 */
171void test_deflate(compr, comprLen)
172    Byte *compr;
173    uLong comprLen;
174{
175    z_stream c_stream; /* compression stream */
176    int err;
177    uLong len = (uLong)strlen(hello)+1;
178
179    c_stream.zalloc = (alloc_func)0;
180    c_stream.zfree = (free_func)0;
181    c_stream.opaque = (voidpf)0;
182
183    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
184    CHECK_ERR(err, "deflateInit");
185
186    c_stream.next_in  = (Bytef*)hello;
187    c_stream.next_out = compr;
188
189    while (c_stream.total_in != len && c_stream.total_out < comprLen) {
190        c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
191        err = deflate(&c_stream, Z_NO_FLUSH);
192        CHECK_ERR(err, "deflate");
193    }
194    /* Finish the stream, still forcing small buffers: */
195    for (;;) {
196        c_stream.avail_out = 1;
197        err = deflate(&c_stream, Z_FINISH);
198        if (err == Z_STREAM_END) break;
199        CHECK_ERR(err, "deflate");
200    }
201
202    err = deflateEnd(&c_stream);
203    CHECK_ERR(err, "deflateEnd");
204}
205
206/* ===========================================================================
207 * Test inflate() with small buffers
208 */
209void test_inflate(compr, comprLen, uncompr, uncomprLen)
210    Byte *compr, *uncompr;
211    uLong comprLen, uncomprLen;
212{
213    int err;
214    z_stream d_stream; /* decompression stream */
215
216    strcpy((char*)uncompr, "garbage");
217
218    d_stream.zalloc = (alloc_func)0;
219    d_stream.zfree = (free_func)0;
220    d_stream.opaque = (voidpf)0;
221
222    d_stream.next_in  = compr;
223    d_stream.avail_in = 0;
224    d_stream.next_out = uncompr;
225
226    err = inflateInit(&d_stream);
227    CHECK_ERR(err, "inflateInit");
228
229    while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
230        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
231        err = inflate(&d_stream, Z_NO_FLUSH);
232        if (err == Z_STREAM_END) break;
233        CHECK_ERR(err, "inflate");
234    }
235
236    err = inflateEnd(&d_stream);
237    CHECK_ERR(err, "inflateEnd");
238
239    if (strcmp((char*)uncompr, hello)) {
240        fprintf(stderr, "bad inflate\n");
241        exit(1);
242    } else {
243        printf("inflate(): %s\n", (char *)uncompr);
244    }
245}
246
247/* ===========================================================================
248 * Test deflate() with large buffers and dynamic change of compression level
249 */
250void test_large_deflate(compr, comprLen, uncompr, uncomprLen)
251    Byte *compr, *uncompr;
252    uLong comprLen, uncomprLen;
253{
254    z_stream c_stream; /* compression stream */
255    int err;
256
257    c_stream.zalloc = (alloc_func)0;
258    c_stream.zfree = (free_func)0;
259    c_stream.opaque = (voidpf)0;
260
261    err = deflateInit(&c_stream, Z_BEST_SPEED);
262    CHECK_ERR(err, "deflateInit");
263
264    c_stream.next_out = compr;
265    c_stream.avail_out = (uInt)comprLen;
266
267    /* At this point, uncompr is still mostly zeroes, so it should compress
268     * very well:
269     */
270    c_stream.next_in = uncompr;
271    c_stream.avail_in = (uInt)uncomprLen;
272    err = deflate(&c_stream, Z_NO_FLUSH);
273    CHECK_ERR(err, "deflate");
274    if (c_stream.avail_in != 0) {
275        fprintf(stderr, "deflate not greedy\n");
276        exit(1);
277    }
278
279    /* Feed in already compressed data and switch to no compression: */
280    deflateParams(&c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
281    c_stream.next_in = compr;
282    c_stream.avail_in = (uInt)comprLen/2;
283    err = deflate(&c_stream, Z_NO_FLUSH);
284    CHECK_ERR(err, "deflate");
285
286    /* Switch back to compressing mode: */
287    deflateParams(&c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
288    c_stream.next_in = uncompr;
289    c_stream.avail_in = (uInt)uncomprLen;
290    err = deflate(&c_stream, Z_NO_FLUSH);
291    CHECK_ERR(err, "deflate");
292
293    err = deflate(&c_stream, Z_FINISH);
294    if (err != Z_STREAM_END) {
295        fprintf(stderr, "deflate should report Z_STREAM_END\n");
296        exit(1);
297    }
298    err = deflateEnd(&c_stream);
299    CHECK_ERR(err, "deflateEnd");
300}
301
302/* ===========================================================================
303 * Test inflate() with large buffers
304 */
305void test_large_inflate(compr, comprLen, uncompr, uncomprLen)
306    Byte *compr, *uncompr;
307    uLong comprLen, uncomprLen;
308{
309    int err;
310    z_stream d_stream; /* decompression stream */
311
312    strcpy((char*)uncompr, "garbage");
313
314    d_stream.zalloc = (alloc_func)0;
315    d_stream.zfree = (free_func)0;
316    d_stream.opaque = (voidpf)0;
317
318    d_stream.next_in  = compr;
319    d_stream.avail_in = (uInt)comprLen;
320
321    err = inflateInit(&d_stream);
322    CHECK_ERR(err, "inflateInit");
323
324    for (;;) {
325        d_stream.next_out = uncompr;            /* discard the output */
326        d_stream.avail_out = (uInt)uncomprLen;
327        err = inflate(&d_stream, Z_NO_FLUSH);
328        if (err == Z_STREAM_END) break;
329        CHECK_ERR(err, "large inflate");
330    }
331
332    err = inflateEnd(&d_stream);
333    CHECK_ERR(err, "inflateEnd");
334
335    if (d_stream.total_out != 2*uncomprLen + comprLen/2) {
336        fprintf(stderr, "bad large inflate: %ld\n", d_stream.total_out);
337        exit(1);
338    } else {
339        printf("large_inflate(): OK\n");
340    }
341}
342
343/* ===========================================================================
344 * Test deflate() with full flush
345 */
346void test_flush(compr, comprLen)
347    Byte *compr;
348    uLong *comprLen;
349{
350    z_stream c_stream; /* compression stream */
351    int err;
352    uInt len = (uInt)strlen(hello)+1;
353
354    c_stream.zalloc = (alloc_func)0;
355    c_stream.zfree = (free_func)0;
356    c_stream.opaque = (voidpf)0;
357
358    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
359    CHECK_ERR(err, "deflateInit");
360
361    c_stream.next_in  = (Bytef*)hello;
362    c_stream.next_out = compr;
363    c_stream.avail_in = 3;
364    c_stream.avail_out = (uInt)*comprLen;
365    err = deflate(&c_stream, Z_FULL_FLUSH);
366    CHECK_ERR(err, "deflate");
367
368    compr[3]++; /* force an error in first compressed block */
369    c_stream.avail_in = len - 3;
370
371    err = deflate(&c_stream, Z_FINISH);
372    if (err != Z_STREAM_END) {
373        CHECK_ERR(err, "deflate");
374    }
375    err = deflateEnd(&c_stream);
376    CHECK_ERR(err, "deflateEnd");
377
378    *comprLen = c_stream.total_out;
379}
380
381/* ===========================================================================
382 * Test inflateSync()
383 */
384void test_sync(compr, comprLen, uncompr, uncomprLen)
385    Byte *compr, *uncompr;
386    uLong comprLen, uncomprLen;
387{
388    int err;
389    z_stream d_stream; /* decompression stream */
390
391    strcpy((char*)uncompr, "garbage");
392
393    d_stream.zalloc = (alloc_func)0;
394    d_stream.zfree = (free_func)0;
395    d_stream.opaque = (voidpf)0;
396
397    d_stream.next_in  = compr;
398    d_stream.avail_in = 2; /* just read the zlib header */
399
400    err = inflateInit(&d_stream);
401    CHECK_ERR(err, "inflateInit");
402
403    d_stream.next_out = uncompr;
404    d_stream.avail_out = (uInt)uncomprLen;
405
406    inflate(&d_stream, Z_NO_FLUSH);
407    CHECK_ERR(err, "inflate");
408
409    d_stream.avail_in = (uInt)comprLen-2;   /* read all compressed data */
410    err = inflateSync(&d_stream);           /* but skip the damaged part */
411    CHECK_ERR(err, "inflateSync");
412
413    err = inflate(&d_stream, Z_FINISH);
414    if (err != Z_DATA_ERROR) {
415        fprintf(stderr, "inflate should report DATA_ERROR\n");
416        /* Because of incorrect adler32 */
417        exit(1);
418    }
419    err = inflateEnd(&d_stream);
420    CHECK_ERR(err, "inflateEnd");
421
422    printf("after inflateSync(): hel%s\n", (char *)uncompr);
423}
424
425/* ===========================================================================
426 * Test deflate() with preset dictionary
427 */
428void test_dict_deflate(compr, comprLen)
429    Byte *compr;
430    uLong comprLen;
431{
432    z_stream c_stream; /* compression stream */
433    int err;
434
435    c_stream.zalloc = (alloc_func)0;
436    c_stream.zfree = (free_func)0;
437    c_stream.opaque = (voidpf)0;
438
439    err = deflateInit(&c_stream, Z_BEST_COMPRESSION);
440    CHECK_ERR(err, "deflateInit");
441
442    err = deflateSetDictionary(&c_stream,
443                               (const Bytef*)dictionary, sizeof(dictionary));
444    CHECK_ERR(err, "deflateSetDictionary");
445
446    dictId = c_stream.adler;
447    c_stream.next_out = compr;
448    c_stream.avail_out = (uInt)comprLen;
449
450    c_stream.next_in = (Bytef*)hello;
451    c_stream.avail_in = (uInt)strlen(hello)+1;
452
453    err = deflate(&c_stream, Z_FINISH);
454    if (err != Z_STREAM_END) {
455        fprintf(stderr, "deflate should report Z_STREAM_END\n");
456        exit(1);
457    }
458    err = deflateEnd(&c_stream);
459    CHECK_ERR(err, "deflateEnd");
460}
461
462/* ===========================================================================
463 * Test inflate() with a preset dictionary
464 */
465void test_dict_inflate(compr, comprLen, uncompr, uncomprLen)
466    Byte *compr, *uncompr;
467    uLong comprLen, uncomprLen;
468{
469    int err;
470    z_stream d_stream; /* decompression stream */
471
472    strcpy((char*)uncompr, "garbage");
473
474    d_stream.zalloc = (alloc_func)0;
475    d_stream.zfree = (free_func)0;
476    d_stream.opaque = (voidpf)0;
477
478    d_stream.next_in  = compr;
479    d_stream.avail_in = (uInt)comprLen;
480
481    err = inflateInit(&d_stream);
482    CHECK_ERR(err, "inflateInit");
483
484    d_stream.next_out = uncompr;
485    d_stream.avail_out = (uInt)uncomprLen;
486
487    for (;;) {
488        err = inflate(&d_stream, Z_NO_FLUSH);
489        if (err == Z_STREAM_END) break;
490        if (err == Z_NEED_DICT) {
491            if (d_stream.adler != dictId) {
492                fprintf(stderr, "unexpected dictionary");
493                exit(1);
494            }
495            err = inflateSetDictionary(&d_stream, (const Bytef*)dictionary,
496                                       sizeof(dictionary));
497        }
498        CHECK_ERR(err, "inflate with dict");
499    }
500
501    err = inflateEnd(&d_stream);
502    CHECK_ERR(err, "inflateEnd");
503
504    if (strcmp((char*)uncompr, hello)) {
505        fprintf(stderr, "bad inflate with dict\n");
506        exit(1);
507    } else {
508        printf("inflate with dictionary: %s\n", (char *)uncompr);
509    }
510}
511
512/* ===========================================================================
513 * Usage:  example [output.gz  [input.gz]]
514 */
515
516int main(argc, argv)
517    int argc;
518    char *argv[];
519{
520    Byte *compr, *uncompr;
521    uLong comprLen = 10000*sizeof(int); /* don't overflow on MSDOS */
522    uLong uncomprLen = comprLen;
523    static const char* myVersion = ZLIB_VERSION;
524
525    if (zlibVersion()[0] != myVersion[0]) {
526        fprintf(stderr, "incompatible zlib version\n");
527        exit(1);
528
529    } else if (strcmp(zlibVersion(), ZLIB_VERSION) != 0) {
530        fprintf(stderr, "warning: different zlib version\n");
531    }
532
533    printf("zlib version %s = 0x%04x, compile flags = 0x%lx\n",
534            ZLIB_VERSION, ZLIB_VERNUM, zlibCompileFlags());
535
536    compr    = (Byte*)calloc((uInt)comprLen, 1);
537    uncompr  = (Byte*)calloc((uInt)uncomprLen, 1);
538    /* compr and uncompr are cleared to avoid reading uninitialized
539     * data and to ensure that uncompr compresses well.
540     */
541    if (compr == Z_NULL || uncompr == Z_NULL) {
542        printf("out of memory\n");
543        exit(1);
544    }
545    test_compress(compr, comprLen, uncompr, uncomprLen);
546
547    test_gzio((argc > 1 ? argv[1] : TESTFILE),
548              uncompr, uncomprLen);
549
550    test_deflate(compr, comprLen);
551    test_inflate(compr, comprLen, uncompr, uncomprLen);
552
553    test_large_deflate(compr, comprLen, uncompr, uncomprLen);
554    test_large_inflate(compr, comprLen, uncompr, uncomprLen);
555
556    test_flush(compr, &comprLen);
557    test_sync(compr, comprLen, uncompr, uncomprLen);
558    comprLen = uncomprLen;
559
560    test_dict_deflate(compr, comprLen);
561    test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
562
563    free(compr);
564    free(uncompr);
565
566    return 0;
567}
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