zlib stream
官方帮助手册
http://www.zlib.net/manual.html
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include "zlib.h"
/* Compress data */
int zcompress(Bytef *data , uLong ndata ,
Bytef * zdata, uLong * nzdata)
{
z_stream c_stream;
int err = 0;
if( data && ndata > 0)
{
c_stream.zalloc = ( alloc_func)0;
c_stream.zfree = ( free_func)0;
c_stream.opaque = ( voidpf)0;
if( deflateInit(&c_stream, Z_DEFAULT_COMPRESSION ) != Z_OK ) return -1;
c_stream.next_in = data;
c_stream.avail_in = ndata;
c_stream.next_out = zdata;
c_stream.avail_out = * nzdata;
while (c_stream.avail_in != 0 && c_stream.total_out < * nzdata)
{
if(deflate(&c_stream, Z_NO_FLUSH) != Z_OK ) return -1;
}
if(c_stream.avail_in != 0) return c_stream.avail_in;
for (;;) {
if((err = deflate(&c_stream, Z_FINISH)) == Z_STREAM_END) break;
if(err != Z_OK) return -1;
}
if(deflateEnd(&c_stream) != Z_OK) return -1;
* nzdata = c_stream.total_out;
return 0;
}
return -1;
}
/* Compress gzip data */
int gzcompress(Bytef *data , uLong ndata ,
Bytef * zdata, uLong * nzdata)
{
z_stream c_stream;
int err = 0;
if( data && ndata > 0)
{
c_stream.zalloc = ( alloc_func)0;
c_stream.zfree = ( free_func)0;
c_stream.opaque = ( voidpf)0;
if( deflateInit2(&c_stream, Z_DEFAULT_COMPRESSION , Z_DEFLATED ,
- MAX_WBITS, 8, Z_DEFAULT_STRATEGY) != Z_OK ) return -1;
c_stream.next_in = data;
c_stream.avail_in = ndata;
c_stream.next_out = zdata;
c_stream.avail_out = * nzdata;
while (c_stream.avail_in != 0 && c_stream.total_out < * nzdata)
{
if(deflate(&c_stream, Z_NO_FLUSH) != Z_OK ) return -1;
}
if(c_stream.avail_in != 0) return c_stream.avail_in;
for (;;) {
if((err = deflate(&c_stream, Z_FINISH)) == Z_STREAM_END) break;
if(err != Z_OK) return -1;
}
if(deflateEnd(&c_stream) != Z_OK) return -1;
* nzdata = c_stream.total_out;
return 0;
}
return -1;
}
/* Uncompress data */
int zdecompress(Byte *zdata , uLong nzdata ,
Byte * data, uLong * ndata)
{
int err = 0;
z_stream d_stream; /* decompression stream */
d_stream.zalloc = ( alloc_func)0;
d_stream.zfree = ( free_func)0;
d_stream.opaque = ( voidpf)0;
d_stream.next_in = zdata;
d_stream.avail_in = 0;
d_stream.next_out = data;
if( inflateInit(&d_stream) != Z_OK ) return -1;
while (d_stream.total_out < * ndata && d_stream.total_in < nzdata) {
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
if((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_STREAM_END ) break ;
if(err != Z_OK) return -1;
}
if(inflateEnd(&d_stream) != Z_OK) return -1;
* ndata = d_stream.total_out;
return 0;
}
/* HTTP gzip decompress */
int httpgzdecompress(Byte *zdata , uLong nzdata ,
Byte * data, uLong * ndata)
{
int err = 0;
z_stream d_stream = {0}; /* decompression stream */
static char dummy_head[2] =
{
0x8 + 0x7 * 0x10,
(((0x8 + 0x7 * 0x10) * 0x100 + 30) / 31 * 31) & 0xFF,
};
d_stream.zalloc = ( alloc_func)0;
d_stream.zfree = ( free_func)0;
d_stream.opaque = ( voidpf)0;
d_stream.next_in = zdata;
d_stream.avail_in = 0;
d_stream.next_out = data;
if( inflateInit2(&d_stream, 47) != Z_OK ) return -1;
while (d_stream.total_out < * ndata && d_stream.total_in < nzdata) {
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
if((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_STREAM_END ) break ;
if(err != Z_OK )
{
if(err == Z_DATA_ERROR)
{
d_stream.next_in = ( Bytef*) dummy_head;
d_stream.avail_in = sizeof(dummy_head);
if((err = inflate(&d_stream, Z_NO_FLUSH)) != Z_OK )
{
return -1;
}
}
else return -1;
}
}
if(inflateEnd(&d_stream) != Z_OK) return -1;
* ndata = d_stream.total_out;
return 0;
}
/* Uncompress gzip data */
int gzdecompress(Byte *zdata , uLong nzdata ,
Byte * data, uLong * ndata)
{
int err = 0;
z_stream d_stream = {0}; /* decompression stream */
static char dummy_head[2] =
{
0x8 + 0x7 * 0x10,
(((0x8 + 0x7 * 0x10) * 0x100 + 30) / 31 * 31) & 0xFF,
};
int v = 20;
* ndata = 20;
for (;v<65330; v++)
{
zdata[v] = '\0';
}
d_stream.zalloc = ( alloc_func)0;
d_stream.zfree = ( free_func)0;
d_stream.opaque = ( voidpf)0;
d_stream.next_in = zdata;
d_stream.avail_in = 0;
d_stream.next_out = data;
if( inflateInit2(&d_stream, -MAX_WBITS ) != Z_OK ) return -1;
//if(inflateInit2(&d_stream, 47) != Z_OK) return -1;
while (d_stream.total_out < * ndata && d_stream.total_in < nzdata) {
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
if((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_STREAM_END ) break ;
if(err != Z_OK )
{
if(err == Z_DATA_ERROR)
{
d_stream.next_in = ( Bytef*) dummy_head;
d_stream.avail_in = sizeof(dummy_head);
if((err = inflate(&d_stream, Z_NO_FLUSH)) != Z_OK )
{
return -1;
}
}
else return -1;
}
}
if(inflateEnd(&d_stream) != Z_OK) return -1;
* ndata = d_stream.total_out;
return 0;
}
#define BUF_SIZE 65535
int main()
{
char *data = "hello word. this test message for this programe.for our work!hello word. this test message for this programe.for our work!hello word. this test message for this programe.for our work!";
uLong ndata = strlen(data);
Bytef zdata[ BUF_SIZE];
uLong nzdata = BUF_SIZE;
Bytef odata[ BUF_SIZE];
uLong nodata = BUF_SIZE;
memset(zdata, 0, BUF_SIZE);
//if(zcompress((Bytef *)data, ndata, zdata, &nzdata) == 0)
if(gzcompress(( Bytef *)data, ndata, zdata, &nzdata) == 0)
{
fprintf( stdout, "nzdata:%d %s\n", nzdata, zdata);
memset(odata, 0, BUF_SIZE);
//if(zdecompress(zdata, ndata, odata, &nodata) == 0)
if(gzdecompress(zdata, ndata, odata, &nodata) == 0)
//if(httpgzdecompress(zdata, ndata, odata, &nodata) == 0)
{
fprintf( stdout, "%d %s\n", nodata, odata);
}
}
}
