-/*
- * uses the same calling syntax as compress2(), but it
- * creates a stream compatible with HTTP "Content-encoding: gzip"
- */
-#ifdef HAVE_ZLIB
-#define DEF_MEM_LEVEL 8
-#define OS_CODE 0x03 /* unix */
-int ZEXPORT compress_gzip(Bytef * dest, /* compressed buffer */
- size_t * destLen, /* length of the compresed data */
- const Bytef * source, /* source to encode */
- uLong sourceLen, /* length of source to encode */
- int level) /* compression level */
-{
- const int gz_magic[2] = { 0x1f, 0x8b }; /* gzip magic header */
-
- /* write gzip header */
- snprintf((char *) dest, *destLen,
- "%c%c%c%c%c%c%c%c%c%c",
- gz_magic[0], gz_magic[1], Z_DEFLATED,
- 0 /*flags */ , 0, 0, 0, 0 /*time */ , 0 /* xflags */ ,
- OS_CODE);
-
- /* normal deflate */
- z_stream stream;
- int err;
- stream.next_in = (Bytef *) source;
- stream.avail_in = (uInt) sourceLen;
- stream.next_out = dest + 10L; // after header
- stream.avail_out = (uInt) * destLen;
- if ((uLong) stream.avail_out != *destLen)
- return Z_BUF_ERROR;
-
- stream.zalloc = (alloc_func) 0;
- stream.zfree = (free_func) 0;
- stream.opaque = (voidpf) 0;
-
- err = deflateInit2(&stream, level, Z_DEFLATED, -MAX_WBITS,
- DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
- if (err != Z_OK)
- return err;
-
- err = deflate(&stream, Z_FINISH);
- if (err != Z_STREAM_END) {
- deflateEnd(&stream);
- return err == Z_OK ? Z_BUF_ERROR : err;
- }
- *destLen = stream.total_out + 10L;
-
- /* write CRC and Length */
- uLong crc = crc32(0L, source, sourceLen);
- int n;
- for (n = 0; n < 4; ++n, ++*destLen) {
- dest[*destLen] = (int) (crc & 0xff);
- crc >>= 8;
- }
- uLong len = stream.total_in;
- for (n = 0; n < 4; ++n, ++*destLen) {
- dest[*destLen] = (int) (len & 0xff);
- len >>= 8;