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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* gzip.c
*
* Copyright (C) 2021 David Oberhollenzer <goliath@infraroot.at>
*/
#include <stdlib.h>
#include <stdio.h>
#include <zlib.h>
#include "xfrm/stream.h"
#include "xfrm/compress.h"
typedef struct {
xfrm_stream_t base;
z_stream strm;
bool compress;
} xfrm_stream_gzip_t;
static const int zlib_action[] = {
[XFRM_STREAM_FLUSH_NONE] = Z_NO_FLUSH,
[XFRM_STREAM_FLUSH_SYNC] = Z_SYNC_FLUSH,
[XFRM_STREAM_FLUSH_FULL] = Z_FINISH,
};
static int process_data(xfrm_stream_t *stream, const void *in,
sqfs_u32 in_size, void *out, sqfs_u32 out_size,
sqfs_u32 *in_read, sqfs_u32 *out_written,
int flush_mode)
{
xfrm_stream_gzip_t *gzip = (xfrm_stream_gzip_t *)stream;
sqfs_u32 diff;
int ret;
if (flush_mode < 0 || flush_mode >= XFRM_STREAM_FLUSH_COUNT)
flush_mode = XFRM_STREAM_FLUSH_NONE;
while (in_size > 0 && out_size > 0) {
gzip->strm.next_in = (void *)in;
gzip->strm.avail_in = in_size;
gzip->strm.next_out = out;
gzip->strm.avail_out = out_size;
if (gzip->compress) {
ret = deflate(&gzip->strm, zlib_action[flush_mode]);
} else {
ret = inflate(&gzip->strm, zlib_action[flush_mode]);
}
if (ret == Z_STREAM_ERROR)
return XFRM_STREAM_ERROR;
diff = in_size - gzip->strm.avail_in;
in = (const char *)in + diff;
in_size -= diff;
*in_read += diff;
diff = out_size - gzip->strm.avail_out;
out = (char *)out + diff;
out_size -= diff;
*out_written += diff;
if (ret == Z_STREAM_END) {
if (gzip->compress) {
ret = deflateReset(&gzip->strm);
} else {
ret = inflateReset(&gzip->strm);
}
if (ret != Z_OK)
return XFRM_STREAM_ERROR;
return XFRM_STREAM_END;
}
if (ret == Z_BUF_ERROR)
return XFRM_STREAM_BUFFER_FULL;
}
return XFRM_STREAM_OK;
}
static void destroy(sqfs_object_t *obj)
{
xfrm_stream_gzip_t *gzip = (xfrm_stream_gzip_t *)obj;
if (gzip->compress) {
deflateEnd(&gzip->strm);
} else {
inflateEnd(&gzip->strm);
}
free(gzip);
}
static xfrm_stream_t *create_stream(const compressor_config_t *cfg,
bool compress)
{
xfrm_stream_gzip_t *gzip = calloc(1, sizeof(*gzip));
xfrm_stream_t *xfrm = (xfrm_stream_t *)gzip;
int ret;
if (gzip == NULL) {
perror("creating gzip stream compressor");
return NULL;
}
if (compress) {
int level = COMP_GZIP_DEFAULT_LEVEL;
int wnd = COMP_GZIP_DEFAULT_WINDOW;
if (cfg != NULL) {
level = cfg->level;
wnd = cfg->opt.gzip.window_size;
}
ret = deflateInit2(&gzip->strm, level, Z_DEFLATED,
wnd + 16, 8, Z_DEFAULT_STRATEGY);
} else {
ret = inflateInit2(&gzip->strm, 16 + 15);
}
if (ret != Z_OK) {
fputs("internal error creating gzip compressor.\n", stderr);
free(gzip);
return NULL;
}
gzip->compress = compress;
xfrm->process_data = process_data;
sqfs_object_init(xfrm, destroy, NULL);
return xfrm;
}
xfrm_stream_t *compressor_stream_gzip_create(const compressor_config_t *cfg)
{
return create_stream(cfg, true);
}
xfrm_stream_t *decompressor_stream_gzip_create(void)
{
return create_stream(NULL, false);
}
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