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#include <assert.h>
#include <zlib.h>
#include "zbuffer.h"
#define BUFSZ_ZOUT (256*1024)
struct zbuffer {
u8 *out;
i64 outfill;
z_stream strm;
zbuffer_writefunc *wf;
void *payload;
};
struct zbuffer* zbuffer_init(zbuffer_writefunc *wf,void *payload){
struct zbuffer *z=malloc(1,struct zbuffer);
z->out=malloc(BUFSZ_ZOUT,u8);
z->outfill=0;
z->strm.zalloc=Z_NULL;
z->strm.zfree=Z_NULL;
z->strm.opaque=Z_NULL;
// so zbuffer_write can start writing immediately
z->strm.avail_out=BUFSZ_ZOUT;
z->strm.next_out=z->out;
if(deflateInit(&z->strm,Z_DEFAULT_COMPRESSION)!=Z_OK){
return NULL;
}
z->wf=wf;
z->payload=payload;
return z;
}
void zbuffer_write(struct zbuffer *z,u8 *data,i64 len){
z->strm.avail_in=len;
z->strm.next_in=data;
assert(z->strm.avail_out>0);
while(true){
int ret=deflate(&z->strm,Z_NO_FLUSH);
assert(ret==Z_OK);
if(z->strm.avail_out>0)break;
z->wf(z->out,BUFSZ_ZOUT,z->payload);
z->strm.avail_out=BUFSZ_ZOUT;
z->strm.next_out=z->out;
}
assert(z->strm.avail_in==0);
}
void zbuffer_flush(struct zbuffer *z){
assert(z->strm.avail_out>0);
while(true){
int ret=deflate(&z->strm,Z_SYNC_FLUSH);
assert(ret==Z_OK);
z->wf(z->out,BUFSZ_ZOUT-z->strm.avail_out,z->payload);
bool done=z->strm.avail_out>0;
z->strm.avail_out=BUFSZ_ZOUT;
z->strm.next_out=z->out;
if(done)break;
}
}
void zbuffer_finish_destroy(struct zbuffer *z){
assert(z->strm.avail_out>0);
while(true){
int ret=deflate(&z->strm,Z_FINISH);
assert(ret==Z_OK||ret==Z_STREAM_END);
z->wf(z->out,BUFSZ_ZOUT-z->strm.avail_out,z->payload);
if(z->strm.avail_out>0)break;
z->strm.avail_out=BUFSZ_ZOUT;
z->strm.next_out=z->out;
}
free(z->out);
free(z);
}
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