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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 <zstd.h>
#include "internal.h"
#define ZSTD_DEFAULT_COMPRESSION_LEVEL 15
typedef struct {
compressor_t base;
ZSTD_CCtx *zctx;
} zstd_compressor_t;
static int zstd_write_options(compressor_t *base, int fd)
{
(void)base; (void)fd;
return 0;
}
static int zstd_read_options(compressor_t *base, int fd)
{
(void)base; (void)fd;
fputs("zstd extra options are not yet implemented\n", stderr);
return -1;
}
static ssize_t zstd_comp_block(compressor_t *base, const uint8_t *in,
size_t size, uint8_t *out, size_t outsize)
{
zstd_compressor_t *zstd = (zstd_compressor_t *)base;
size_t ret;
ret = ZSTD_compressCCtx(zstd->zctx, out, outsize, in, size,
ZSTD_DEFAULT_COMPRESSION_LEVEL);
if (ZSTD_isError(ret)) {
fputs("internal error in ZSTD compressor\n", stderr);
return -1;
}
return ret < size ? ret : 0;
}
static ssize_t zstd_uncomp_block(compressor_t *base, const uint8_t *in,
size_t size, uint8_t *out, size_t outsize)
{
size_t ret;
(void)base;
ret = ZSTD_decompress(out, outsize, in, size);
if (ZSTD_isError(ret)) {
fputs("error uncompressing ZSTD compressed data", stderr);
return -1;
}
return ret;
}
static void zstd_destroy(compressor_t *base)
{
zstd_compressor_t *zstd = (zstd_compressor_t *)base;
ZSTD_freeCCtx(zstd->zctx);
free(zstd);
}
compressor_t *create_zstd_compressor(bool compress, size_t block_size)
{
zstd_compressor_t *zstd = calloc(1, sizeof(*zstd));
compressor_t *base = (compressor_t *)zstd;
(void)block_size;
if (zstd == NULL) {
perror("creating zstd compressor");
return NULL;
}
zstd->zctx = ZSTD_createCCtx();
if (zstd->zctx == NULL) {
fputs("error creating zstd compression context\n", stderr);
free(zstd);
return NULL;
}
base->destroy = zstd_destroy;
base->do_block = compress ? zstd_comp_block : zstd_uncomp_block;
base->write_options = zstd_write_options;
base->read_options = zstd_read_options;
return base;
}
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