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/* SPDX-License-Identifier: GPL-3.0-or-later */
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <zlib.h>
#include "internal.h"
typedef struct {
compressor_t base;
z_stream strm;
bool compress;
size_t block_size;
} gzip_compressor_t;
static void gzip_destroy(compressor_t *base)
{
gzip_compressor_t *gzip = (gzip_compressor_t *)base;
if (gzip->compress) {
deflateEnd(&gzip->strm);
} else {
inflateEnd(&gzip->strm);
}
free(gzip);
}
static int gzip_write_options(compressor_t *base, int fd)
{
(void)base;
(void)fd;
return 0;
}
static int gzip_read_options(compressor_t *base, int fd)
{
(void)base;
(void)fd;
fputs("gzip extra options are not yet implemented\n", stderr);
return -1;
}
static ssize_t gzip_do_block(compressor_t *base, const uint8_t *in,
size_t size, uint8_t *out, size_t outsize)
{
gzip_compressor_t *gzip = (gzip_compressor_t *)base;
size_t written;
int ret;
if (gzip->compress) {
ret = deflateReset(&gzip->strm);
} else {
ret = inflateReset(&gzip->strm);
}
if (ret != Z_OK) {
fputs("resetting zlib stream failed\n", stderr);
return -1;
}
gzip->strm.next_in = (void *)in;
gzip->strm.avail_in = size;
gzip->strm.next_out = out;
gzip->strm.avail_out = outsize;
if (gzip->compress) {
ret = deflate(&gzip->strm, Z_FINISH);
} else {
ret = inflate(&gzip->strm, Z_FINISH);
}
if (ret == Z_STREAM_END) {
written = gzip->strm.total_out;
if (gzip->compress && written >= size)
return 0;
return (ssize_t)written;
}
if (ret != Z_OK) {
fputs("gzip block processing failed\n", stderr);
return -1;
}
return 0;
}
compressor_t *create_gzip_compressor(bool compress, size_t block_size)
{
gzip_compressor_t *gzip = calloc(1, sizeof(*gzip));
compressor_t *base = (compressor_t *)gzip;
int ret;
if (gzip == NULL) {
perror("creating gzip compressor");
return NULL;
}
gzip->compress = compress;
gzip->block_size = block_size;
base->do_block = gzip_do_block;
base->destroy = gzip_destroy;
base->write_options = gzip_write_options;
base->read_options = gzip_read_options;
if (compress) {
ret = deflateInit(&gzip->strm, Z_BEST_COMPRESSION);
} else {
ret = inflateInit(&gzip->strm);
}
if (ret != Z_OK) {
fputs("internal error creating zlib stream\n", stderr);
free(gzip);
return NULL;
}
return base;
}
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