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+/* example.c -- usage example of the zlib compression library
+ * Copyright (C) 1995-2006 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zlib.h"
+#include <stdio.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;
+}