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Diffstat (limited to 'zlib/example.c')
| -rw-r--r-- | zlib/example.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/zlib/example.c b/zlib/example.c new file mode 100644 index 000000000..8307c841e --- /dev/null +++ b/zlib/example.c @@ -0,0 +1,556 @@ +/* example.c -- usage example of the zlib compression library + * Copyright (C) 1995-1998 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> +#else + extern void exit OF((int)); +#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 *out, const char *in, + Byte *uncompr, int 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 = 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(out, in, uncompr, uncomprLen) + const char *out; /* compressed output file */ + const char *in; /* compressed input file */ + Byte *uncompr; + int uncomprLen; +{ + int err; + int len = strlen(hello)+1; + gzFile file; + z_off_t pos; + + file = gzopen(out, "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(in, "rb"); + if (file == NULL) { + fprintf(stderr, "gzopen error\n"); + } + strcpy((char*)uncompr, "garbage"); + + uncomprLen = gzread(file, uncompr, (unsigned)uncomprLen); + if (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); + } + + gzgets(file, (char*)uncompr, uncomprLen); + uncomprLen = strlen((char*)uncompr); + if (uncomprLen != 6) { /* "hello!" */ + fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err)); + exit(1); + } + if (strcmp((char*)uncompr, hello+7)) { + fprintf(stderr, "bad gzgets after gzseek\n"); + exit(1); + } else { + printf("gzgets() after gzseek: %s\n", (char *)uncompr); + } + + gzclose(file); +} + +/* =========================================================================== + * Test deflate() with small buffers + */ +void test_deflate(compr, comprLen) + Byte *compr; + uLong comprLen; +{ + z_stream c_stream; /* compression stream */ + int err; + int len = 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 != (uLong)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; + int len = 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"); + } + + 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), + (argc > 2 ? argv[2] : TESTFILE), + uncompr, (int)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); + + exit(0); + return 0; /* to avoid warning */ +} |