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/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
Copyright (C) 2010 Red Hat, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <zlib.h>
#include "red-common.h"
#include "zlib-encoder.h"
struct ZlibEncoder {
ZlibEncoderUsrContext *usr;
z_stream strm;
int last_level;
};
ZlibEncoder* zlib_encoder_create(ZlibEncoderUsrContext *usr, int level)
{
ZlibEncoder *enc;
int z_ret;
if (!usr->more_space || !usr->more_input) {
return NULL;
}
enc = g_new0(ZlibEncoder, 1);
enc->usr = usr;
enc->strm.zalloc = Z_NULL;
enc->strm.zfree = Z_NULL;
enc->strm.opaque = Z_NULL;
z_ret = deflateInit(&enc->strm, level);
enc->last_level = level;
if (z_ret != Z_OK) {
g_warning("zlib error");
g_free(enc);
return NULL;
}
return enc;
}
void zlib_encoder_destroy(ZlibEncoder *encoder)
{
deflateEnd(&encoder->strm);
g_free(encoder);
}
/* returns the total size of the encoded data */
int zlib_encode(ZlibEncoder *zlib, int level, int input_size,
uint8_t *io_ptr, unsigned int num_io_bytes)
{
int flush;
int enc_size = 0;
int out_size = 0;
int z_ret;
z_ret = deflateReset(&zlib->strm);
if (z_ret != Z_OK) {
spice_error("deflateReset failed");
}
zlib->strm.next_out = io_ptr;
zlib->strm.avail_out = num_io_bytes;
if (level != zlib->last_level) {
if (zlib->strm.avail_out == 0) {
zlib->strm.avail_out = zlib->usr->more_space(zlib->usr, &zlib->strm.next_out);
if (zlib->strm.avail_out == 0) {
spice_error("not enough space");
}
}
z_ret = deflateParams(&zlib->strm, level, Z_DEFAULT_STRATEGY);
if (z_ret != Z_OK) {
spice_error("deflateParams failed");
}
zlib->last_level = level;
}
do {
zlib->strm.avail_in = zlib->usr->more_input(zlib->usr, &zlib->strm.next_in);
if (zlib->strm.avail_in <= 0) {
spice_error("more input failed");
}
enc_size += zlib->strm.avail_in;
flush = (enc_size == input_size) ? Z_FINISH : Z_NO_FLUSH;
while (1) {
int deflate_size = zlib->strm.avail_out;
z_ret = deflate(&zlib->strm, flush);
spice_assert(z_ret != Z_STREAM_ERROR);
out_size += deflate_size - zlib->strm.avail_out;
if (zlib->strm.avail_out) {
break;
}
zlib->strm.avail_out = zlib->usr->more_space(zlib->usr, &zlib->strm.next_out);
if (zlib->strm.avail_out == 0) {
spice_error("not enough space");
}
}
} while (flush != Z_FINISH);
spice_assert(z_ret == Z_STREAM_END);
return out_size;
}
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