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/* example.c -- usage example of the zlib compression library

 * Copyright (C) 1995-2003 Jean-loup Gailly.

 * For conditions of distribution and use, see copyright notice in zlib.h

 */

/* @(#) $Id: example.c,v 1.1.1.1 2005/04/24 21:39:37 giles Exp $ */

#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 *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;

}