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/*
* HT Editor
* cstream.cc
*
* Copyright (C) 1999, 2000, 2001 Sebastian Biallas (sb@web-productions.de)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "cstream.h"
#include "htdebug.h"
#include "htendian.h"
#include "minilzo.h"
#include "tools.h"
#include <string.h>
void ht_compressed_stream::init(ht_stream *stream, bool own_stream, UINT granularity=10240)
{
ht_layer_stream::init(stream, own_stream);
if ((get_access_mode() & (FAM_READ | FAM_WRITE)) == (FAM_READ | FAM_WRITE)) {
// ht_compressed_stream cant be used for read and write access simultaneously
assert(0);
}
buffer = (byte *)smalloc(granularity);
bufferpos = 0;
buffersize = granularity;
}
void ht_compressed_stream::done()
{
if (get_access_mode() & FAM_WRITE) {
flush_compressed();
}
if (buffer) free(buffer);
ht_layer_stream::done();
}
bool ht_compressed_stream::flush_compressed()
{
if (bufferpos) {
byte *cbuf = (byte *)smalloc(bufferpos + bufferpos / 64 + 16 + 3);
byte *workbuf = (byte *)smalloc(LZO1X_1_MEM_COMPRESS);
lzo_uint cbuf_len;
byte n[4];
lzo1x_1_compress(buffer, bufferpos, cbuf, &cbuf_len, workbuf);
free(workbuf);
h2n_int(n, bufferpos, 4);
if (stream->write(n, 4)!=4) {
free(cbuf);
return false;
}
h2n_int(n, cbuf_len, 4);
if (stream->write(n, 4)!=4) {
free(cbuf);
return false;
}
if (stream->write(cbuf, cbuf_len)!=cbuf_len) {
free(cbuf);
return false;
}
free(cbuf);
bufferpos = 0;
}
return true;
}
bool ht_compressed_stream::flush_uncompressed()
{
if (bufferpos==0) {
free(buffer);
buffer = NULL;
UINT cbuf_len;
byte n[4];
if (stream->read(n, 4)!=4) return false;
n2h_int((int*)&cbuf_len, n, 4);
if (stream->read(n, 4)!=4) return false;
n2h_int((int*)&cbuf_len, n, 4);
buffer = (byte *)smalloc(buffersize);
byte *cbuf = (byte *)smalloc(cbuf_len);
if (stream->read(cbuf, cbuf_len)!=cbuf_len) return false;
lzo_uint dummy;
lzo1x_decompress(cbuf, cbuf_len, buffer, &dummy, NULL);
free(cbuf);
bufferpos = buffersize;
}
return true;
}
UINT ht_compressed_stream::read(void *buf, UINT size)
{
UINT ssize = size;
while (size >= bufferpos) {
memcpy(buf, buffer+buffersize-bufferpos, bufferpos);
((byte *)buf) += bufferpos;
size -= bufferpos;
bufferpos = 0;
if (size) {
if (!flush_uncompressed()) return ssize - size;
} else break;
}
if (size) {
memcpy(buf, buffer+buffersize-bufferpos, size);
bufferpos -= size;
}
return ssize;
}
UINT ht_compressed_stream::write(void *buf, UINT size)
{
UINT ssize = size;
while (bufferpos+size >= buffersize) {
memcpy(buffer+bufferpos, buf, buffersize-bufferpos);
size -= buffersize-bufferpos;
((byte *)buf) += buffersize-bufferpos;
bufferpos = buffersize;
if (size) {
if (!flush_compressed()) return ssize - size;
} else break;
}
if (size) {
memcpy(buffer+bufferpos, buf, size);
bufferpos += size;
}
return ssize;
}
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