/* example.c -- usage example of the zlib compression library | |
* Copyright (C) 1995-2004 Jean-loup Gailly. | |
* For conditions of distribution and use, see copyright notice in zlib.h | |
*/ | |
/* @(#) $Id$ */ | |
#include <stdio.h> | |
#include "zlib.h" | |
#ifdef STDC | |
# include <string.h> | |
# include <stdlib.h> | |
#endif | |
#if defined(VMS) || defined(RISCOS) | |
# define TESTFILE "foo-gz" | |
#else | |
# define TESTFILE "foo.gz" | |
#endif | |
#define CHECK_ERR(err, msg) { \ | |
if (err != Z_OK) { \ | |
fprintf(stderr, "%s error: %d\n", msg, err); \ | |
exit(1); \ | |
} \ | |
} | |
const char hello[] = "hello, hello!"; | |
/* "hello world" would be more standard, but the repeated "hello" | |
* stresses the compression code better, sorry... | |
*/ | |
const char dictionary[] = "hello"; | |
uLong dictId; /* Adler32 value of the dictionary */ | |
void test_compress OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_gzio OF((const char *fname, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_deflate OF((Byte *compr, uLong comprLen)); | |
void test_inflate OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_large_deflate OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_large_inflate OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_flush OF((Byte *compr, uLong *comprLen)); | |
void test_sync OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
void test_dict_deflate OF((Byte *compr, uLong comprLen)); | |
void test_dict_inflate OF((Byte *compr, uLong comprLen, | |
Byte *uncompr, uLong uncomprLen)); | |
int main OF((int argc, char *argv[])); | |
/* =========================================================================== | |
* Test compress() and uncompress() | |
*/ | |
void test_compress(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
int err; | |
uLong len = (uLong)strlen(hello)+1; | |
err = compress(compr, &comprLen, (const Bytef*)hello, len); | |
CHECK_ERR(err, "compress"); | |
strcpy((char*)uncompr, "garbage"); | |
err = uncompress(uncompr, &uncomprLen, compr, comprLen); | |
CHECK_ERR(err, "uncompress"); | |
if (strcmp((char*)uncompr, hello)) { | |
fprintf(stderr, "bad uncompress\n"); | |
exit(1); | |
} else { | |
printf("uncompress(): %s\n", (char *)uncompr); | |
} | |
} | |
/* =========================================================================== | |
* Test read/write of .gz files | |
*/ | |
void test_gzio(fname, uncompr, uncomprLen) | |
const char *fname; /* compressed file name */ | |
Byte *uncompr; | |
uLong uncomprLen; | |
{ | |
#ifdef NO_GZCOMPRESS | |
fprintf(stderr, "NO_GZCOMPRESS -- gz* functions cannot compress\n"); | |
#else | |
int err; | |
int len = (int)strlen(hello)+1; | |
gzFile file; | |
z_off_t pos; | |
file = gzopen(fname, "wb"); | |
if (file == NULL) { | |
fprintf(stderr, "gzopen error\n"); | |
exit(1); | |
} | |
gzputc(file, 'h'); | |
if (gzputs(file, "ello") != 4) { | |
fprintf(stderr, "gzputs err: %s\n", gzerror(file, &err)); | |
exit(1); | |
} | |
if (gzprintf(file, ", %s!", "hello") != 8) { | |
fprintf(stderr, "gzprintf err: %s\n", gzerror(file, &err)); | |
exit(1); | |
} | |
gzseek(file, 1L, SEEK_CUR); /* add one zero byte */ | |
gzclose(file); | |
file = gzopen(fname, "rb"); | |
if (file == NULL) { | |
fprintf(stderr, "gzopen error\n"); | |
exit(1); | |
} | |
strcpy((char*)uncompr, "garbage"); | |
if (gzread(file, uncompr, (unsigned)uncomprLen) != len) { | |
fprintf(stderr, "gzread err: %s\n", gzerror(file, &err)); | |
exit(1); | |
} | |
if (strcmp((char*)uncompr, hello)) { | |
fprintf(stderr, "bad gzread: %s\n", (char*)uncompr); | |
exit(1); | |
} else { | |
printf("gzread(): %s\n", (char*)uncompr); | |
} | |
pos = gzseek(file, -8L, SEEK_CUR); | |
if (pos != 6 || gztell(file) != pos) { | |
fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n", | |
(long)pos, (long)gztell(file)); | |
exit(1); | |
} | |
if (gzgetc(file) != ' ') { | |
fprintf(stderr, "gzgetc error\n"); | |
exit(1); | |
} | |
if (gzungetc(' ', file) != ' ') { | |
fprintf(stderr, "gzungetc error\n"); | |
exit(1); | |
} | |
gzgets(file, (char*)uncompr, (int)uncomprLen); | |
if (strlen((char*)uncompr) != 7) { /* " hello!" */ | |
fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err)); | |
exit(1); | |
} | |
if (strcmp((char*)uncompr, hello + 6)) { | |
fprintf(stderr, "bad gzgets after gzseek\n"); | |
exit(1); | |
} else { | |
printf("gzgets() after gzseek: %s\n", (char*)uncompr); | |
} | |
gzclose(file); | |
#endif | |
} | |
/* =========================================================================== | |
* Test deflate() with small buffers | |
*/ | |
void test_deflate(compr, comprLen) | |
Byte *compr; | |
uLong comprLen; | |
{ | |
z_stream c_stream; /* compression stream */ | |
int err; | |
uLong len = (uLong)strlen(hello)+1; | |
c_stream.zalloc = (alloc_func)0; | |
c_stream.zfree = (free_func)0; | |
c_stream.opaque = (voidpf)0; | |
err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION); | |
CHECK_ERR(err, "deflateInit"); | |
c_stream.next_in = (Bytef*)hello; | |
c_stream.next_out = compr; | |
while (c_stream.total_in != len && c_stream.total_out < comprLen) { | |
c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */ | |
err = deflate(&c_stream, Z_NO_FLUSH); | |
CHECK_ERR(err, "deflate"); | |
} | |
/* Finish the stream, still forcing small buffers: */ | |
for (;;) { | |
c_stream.avail_out = 1; | |
err = deflate(&c_stream, Z_FINISH); | |
if (err == Z_STREAM_END) break; | |
CHECK_ERR(err, "deflate"); | |
} | |
err = deflateEnd(&c_stream); | |
CHECK_ERR(err, "deflateEnd"); | |
} | |
/* =========================================================================== | |
* Test inflate() with small buffers | |
*/ | |
void test_inflate(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
int err; | |
z_stream d_stream; /* decompression stream */ | |
strcpy((char*)uncompr, "garbage"); | |
d_stream.zalloc = (alloc_func)0; | |
d_stream.zfree = (free_func)0; | |
d_stream.opaque = (voidpf)0; | |
d_stream.next_in = compr; | |
d_stream.avail_in = 0; | |
d_stream.next_out = uncompr; | |
err = inflateInit(&d_stream); | |
CHECK_ERR(err, "inflateInit"); | |
while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) { | |
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */ | |
err = inflate(&d_stream, Z_NO_FLUSH); | |
if (err == Z_STREAM_END) break; | |
CHECK_ERR(err, "inflate"); | |
} | |
err = inflateEnd(&d_stream); | |
CHECK_ERR(err, "inflateEnd"); | |
if (strcmp((char*)uncompr, hello)) { | |
fprintf(stderr, "bad inflate\n"); | |
exit(1); | |
} else { | |
printf("inflate(): %s\n", (char *)uncompr); | |
} | |
} | |
/* =========================================================================== | |
* Test deflate() with large buffers and dynamic change of compression level | |
*/ | |
void test_large_deflate(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
z_stream c_stream; /* compression stream */ | |
int err; | |
c_stream.zalloc = (alloc_func)0; | |
c_stream.zfree = (free_func)0; | |
c_stream.opaque = (voidpf)0; | |
err = deflateInit(&c_stream, Z_BEST_SPEED); | |
CHECK_ERR(err, "deflateInit"); | |
c_stream.next_out = compr; | |
c_stream.avail_out = (uInt)comprLen; | |
/* At this point, uncompr is still mostly zeroes, so it should compress | |
* very well: | |
*/ | |
c_stream.next_in = uncompr; | |
c_stream.avail_in = (uInt)uncomprLen; | |
err = deflate(&c_stream, Z_NO_FLUSH); | |
CHECK_ERR(err, "deflate"); | |
if (c_stream.avail_in != 0) { | |
fprintf(stderr, "deflate not greedy\n"); | |
exit(1); | |
} | |
/* Feed in already compressed data and switch to no compression: */ | |
deflateParams(&c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY); | |
c_stream.next_in = compr; | |
c_stream.avail_in = (uInt)comprLen/2; | |
err = deflate(&c_stream, Z_NO_FLUSH); | |
CHECK_ERR(err, "deflate"); | |
/* Switch back to compressing mode: */ | |
deflateParams(&c_stream, Z_BEST_COMPRESSION, Z_FILTERED); | |
c_stream.next_in = uncompr; | |
c_stream.avail_in = (uInt)uncomprLen; | |
err = deflate(&c_stream, Z_NO_FLUSH); | |
CHECK_ERR(err, "deflate"); | |
err = deflate(&c_stream, Z_FINISH); | |
if (err != Z_STREAM_END) { | |
fprintf(stderr, "deflate should report Z_STREAM_END\n"); | |
exit(1); | |
} | |
err = deflateEnd(&c_stream); | |
CHECK_ERR(err, "deflateEnd"); | |
} | |
/* =========================================================================== | |
* Test inflate() with large buffers | |
*/ | |
void test_large_inflate(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
int err; | |
z_stream d_stream; /* decompression stream */ | |
strcpy((char*)uncompr, "garbage"); | |
d_stream.zalloc = (alloc_func)0; | |
d_stream.zfree = (free_func)0; | |
d_stream.opaque = (voidpf)0; | |
d_stream.next_in = compr; | |
d_stream.avail_in = (uInt)comprLen; | |
err = inflateInit(&d_stream); | |
CHECK_ERR(err, "inflateInit"); | |
for (;;) { | |
d_stream.next_out = uncompr; /* discard the output */ | |
d_stream.avail_out = (uInt)uncomprLen; | |
err = inflate(&d_stream, Z_NO_FLUSH); | |
if (err == Z_STREAM_END) break; | |
CHECK_ERR(err, "large inflate"); | |
} | |
err = inflateEnd(&d_stream); | |
CHECK_ERR(err, "inflateEnd"); | |
if (d_stream.total_out != 2*uncomprLen + comprLen/2) { | |
fprintf(stderr, "bad large inflate: %ld\n", d_stream.total_out); | |
exit(1); | |
} else { | |
printf("large_inflate(): OK\n"); | |
} | |
} | |
/* =========================================================================== | |
* Test deflate() with full flush | |
*/ | |
void test_flush(compr, comprLen) | |
Byte *compr; | |
uLong *comprLen; | |
{ | |
z_stream c_stream; /* compression stream */ | |
int err; | |
uInt len = (uInt)strlen(hello)+1; | |
c_stream.zalloc = (alloc_func)0; | |
c_stream.zfree = (free_func)0; | |
c_stream.opaque = (voidpf)0; | |
err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION); | |
CHECK_ERR(err, "deflateInit"); | |
c_stream.next_in = (Bytef*)hello; | |
c_stream.next_out = compr; | |
c_stream.avail_in = 3; | |
c_stream.avail_out = (uInt)*comprLen; | |
err = deflate(&c_stream, Z_FULL_FLUSH); | |
CHECK_ERR(err, "deflate"); | |
compr[3]++; /* force an error in first compressed block */ | |
c_stream.avail_in = len - 3; | |
err = deflate(&c_stream, Z_FINISH); | |
if (err != Z_STREAM_END) { | |
CHECK_ERR(err, "deflate"); | |
} | |
err = deflateEnd(&c_stream); | |
CHECK_ERR(err, "deflateEnd"); | |
*comprLen = c_stream.total_out; | |
} | |
/* =========================================================================== | |
* Test inflateSync() | |
*/ | |
void test_sync(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
int err; | |
z_stream d_stream; /* decompression stream */ | |
strcpy((char*)uncompr, "garbage"); | |
d_stream.zalloc = (alloc_func)0; | |
d_stream.zfree = (free_func)0; | |
d_stream.opaque = (voidpf)0; | |
d_stream.next_in = compr; | |
d_stream.avail_in = 2; /* just read the zlib header */ | |
err = inflateInit(&d_stream); | |
CHECK_ERR(err, "inflateInit"); | |
d_stream.next_out = uncompr; | |
d_stream.avail_out = (uInt)uncomprLen; | |
inflate(&d_stream, Z_NO_FLUSH); | |
CHECK_ERR(err, "inflate"); | |
d_stream.avail_in = (uInt)comprLen-2; /* read all compressed data */ | |
err = inflateSync(&d_stream); /* but skip the damaged part */ | |
CHECK_ERR(err, "inflateSync"); | |
err = inflate(&d_stream, Z_FINISH); | |
if (err != Z_DATA_ERROR) { | |
fprintf(stderr, "inflate should report DATA_ERROR\n"); | |
/* Because of incorrect adler32 */ | |
exit(1); | |
} | |
err = inflateEnd(&d_stream); | |
CHECK_ERR(err, "inflateEnd"); | |
printf("after inflateSync(): hel%s\n", (char *)uncompr); | |
} | |
/* =========================================================================== | |
* Test deflate() with preset dictionary | |
*/ | |
void test_dict_deflate(compr, comprLen) | |
Byte *compr; | |
uLong comprLen; | |
{ | |
z_stream c_stream; /* compression stream */ | |
int err; | |
c_stream.zalloc = (alloc_func)0; | |
c_stream.zfree = (free_func)0; | |
c_stream.opaque = (voidpf)0; | |
err = deflateInit(&c_stream, Z_BEST_COMPRESSION); | |
CHECK_ERR(err, "deflateInit"); | |
err = deflateSetDictionary(&c_stream, | |
(const Bytef*)dictionary, sizeof(dictionary)); | |
CHECK_ERR(err, "deflateSetDictionary"); | |
dictId = c_stream.adler; | |
c_stream.next_out = compr; | |
c_stream.avail_out = (uInt)comprLen; | |
c_stream.next_in = (Bytef*)hello; | |
c_stream.avail_in = (uInt)strlen(hello)+1; | |
err = deflate(&c_stream, Z_FINISH); | |
if (err != Z_STREAM_END) { | |
fprintf(stderr, "deflate should report Z_STREAM_END\n"); | |
exit(1); | |
} | |
err = deflateEnd(&c_stream); | |
CHECK_ERR(err, "deflateEnd"); | |
} | |
/* =========================================================================== | |
* Test inflate() with a preset dictionary | |
*/ | |
void test_dict_inflate(compr, comprLen, uncompr, uncomprLen) | |
Byte *compr, *uncompr; | |
uLong comprLen, uncomprLen; | |
{ | |
int err; | |
z_stream d_stream; /* decompression stream */ | |
strcpy((char*)uncompr, "garbage"); | |
d_stream.zalloc = (alloc_func)0; | |
d_stream.zfree = (free_func)0; | |
d_stream.opaque = (voidpf)0; | |
d_stream.next_in = compr; | |
d_stream.avail_in = (uInt)comprLen; | |
err = inflateInit(&d_stream); | |
CHECK_ERR(err, "inflateInit"); | |
d_stream.next_out = uncompr; | |
d_stream.avail_out = (uInt)uncomprLen; | |
for (;;) { | |
err = inflate(&d_stream, Z_NO_FLUSH); | |
if (err == Z_STREAM_END) break; | |
if (err == Z_NEED_DICT) { | |
if (d_stream.adler != dictId) { | |
fprintf(stderr, "unexpected dictionary"); | |
exit(1); | |
} | |
err = inflateSetDictionary(&d_stream, (const Bytef*)dictionary, | |
sizeof(dictionary)); | |
} | |
CHECK_ERR(err, "inflate with dict"); | |
} | |
err = inflateEnd(&d_stream); | |
CHECK_ERR(err, "inflateEnd"); | |
if (strcmp((char*)uncompr, hello)) { | |
fprintf(stderr, "bad inflate with dict\n"); | |
exit(1); | |
} else { | |
printf("inflate with dictionary: %s\n", (char *)uncompr); | |
} | |
} | |
/* =========================================================================== | |
* Usage: example [output.gz [input.gz]] | |
*/ | |
int main(argc, argv) | |
int argc; | |
char *argv[]; | |
{ | |
Byte *compr, *uncompr; | |
uLong comprLen = 10000*sizeof(int); /* don't overflow on MSDOS */ | |
uLong uncomprLen = comprLen; | |
static const char* myVersion = ZLIB_VERSION; | |
if (zlibVersion()[0] != myVersion[0]) { | |
fprintf(stderr, "incompatible zlib version\n"); | |
exit(1); | |
} else if (strcmp(zlibVersion(), ZLIB_VERSION) != 0) { | |
fprintf(stderr, "warning: different zlib version\n"); | |
} | |
printf("zlib version %s = 0x%04x, compile flags = 0x%lx\n", | |
ZLIB_VERSION, ZLIB_VERNUM, zlibCompileFlags()); | |
compr = (Byte*)calloc((uInt)comprLen, 1); | |
uncompr = (Byte*)calloc((uInt)uncomprLen, 1); | |
/* compr and uncompr are cleared to avoid reading uninitialized | |
* data and to ensure that uncompr compresses well. | |
*/ | |
if (compr == Z_NULL || uncompr == Z_NULL) { | |
printf("out of memory\n"); | |
exit(1); | |
} | |
test_compress(compr, comprLen, uncompr, uncomprLen); | |
test_gzio((argc > 1 ? argv[1] : TESTFILE), | |
uncompr, uncomprLen); | |
test_deflate(compr, comprLen); | |
test_inflate(compr, comprLen, uncompr, uncomprLen); | |
test_large_deflate(compr, comprLen, uncompr, uncomprLen); | |
test_large_inflate(compr, comprLen, uncompr, uncomprLen); | |
test_flush(compr, &comprLen); | |
test_sync(compr, comprLen, uncompr, uncomprLen); | |
comprLen = uncomprLen; | |
test_dict_deflate(compr, comprLen); | |
test_dict_inflate(compr, comprLen, uncompr, uncomprLen); | |
free(compr); | |
free(uncompr); | |
return 0; | |
} |