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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* lz4.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <lz4.h>
#include <lz4hc.h>
#include "internal.h"
typedef struct {
compressor_t base;
bool high_compression;
} lz4_compressor_t;
typedef struct {
uint32_t version;
uint32_t flags;
} lz4_options;
#define LZ4LEGACY 1
#define LZ4_FLAG_HC 0x01
static int lz4_write_options(compressor_t *base, int fd)
{
lz4_compressor_t *lz4 = (lz4_compressor_t *)base;
lz4_options opt = {
.version = htole32(LZ4LEGACY),
.flags = htole32(lz4->high_compression ? LZ4_FLAG_HC : 0),
};
return generic_write_options(fd, &opt, sizeof(opt));
}
static int lz4_read_options(compressor_t *base, int fd)
{
lz4_options opt;
(void)base;
if (generic_read_options(fd, &opt, sizeof(opt)))
return -1;
opt.version = le32toh(opt.version);
opt.flags = le32toh(opt.flags);
if (opt.version != LZ4LEGACY) {
fprintf(stderr, "unsupported lz4 version '%d'\n", opt.version);
return -1;
}
return 0;
}
static ssize_t lz4_comp_block(compressor_t *base, const uint8_t *in,
size_t size, uint8_t *out, size_t outsize)
{
lz4_compressor_t *lz4 = (lz4_compressor_t *)base;
int ret;
if (lz4->high_compression) {
ret = LZ4_compress_HC((void *)in, (void *)out,
size, outsize, LZ4HC_CLEVEL_MAX);
} else {
ret = LZ4_compress_default((void *)in, (void *)out,
size, outsize);
}
if (ret < 0) {
fputs("internal error in lz4 compressor\n", stderr);
return -1;
}
return ret;
}
static ssize_t lz4_uncomp_block(compressor_t *base, const uint8_t *in,
size_t size, uint8_t *out, size_t outsize)
{
int ret;
(void)base;
ret = LZ4_decompress_safe((void *)in, (void *)out, size, outsize);
if (ret < 0) {
fputs("internal error in lz4 decompressor\n", stderr);
return -1;
}
return ret;
}
static compressor_t *lz4_create_copy(compressor_t *cmp)
{
lz4_compressor_t *lz4 = malloc(sizeof(*lz4));
if (lz4 == NULL) {
perror("creating additional lz4 compressor");
return NULL;
}
memcpy(lz4, cmp, sizeof(*lz4));
return (compressor_t *)lz4;
}
static void lz4_destroy(compressor_t *base)
{
free(base);
}
compressor_t *create_lz4_compressor(bool compress, size_t block_size,
char *options)
{
lz4_compressor_t *lz4 = calloc(1, sizeof(*lz4));
compressor_t *base = (compressor_t *)lz4;
(void)block_size;
if (lz4 == NULL) {
perror("creating lz4 compressor");
return NULL;
}
lz4->high_compression = false;
if (options != NULL) {
if (strcmp(options, "hc") == 0) {
lz4->high_compression = true;
} else {
fputs("Unsupported extra options for lz4 "
"compressor.\n", stderr);
free(lz4);
return NULL;
}
}
base->destroy = lz4_destroy;
base->do_block = compress ? lz4_comp_block : lz4_uncomp_block;
base->write_options = lz4_write_options;
base->read_options = lz4_read_options;
base->create_copy = lz4_create_copy;
return base;
}
void compressor_lz4_print_help(void)
{
fputs("Available options for lz4 compressor:\n"
"\n"
" hc If present, use slower but better compressing\n"
" variant of lz4.\n"
"\n",
stdout);
}
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