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/*
* Copyright (c) 2017-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
#include <stdio.h>
#include <stdlib.h>
#include "zstd_decompress.h"
typedef unsigned char u8;
// If the data doesn't have decompressed size with it, fallback on assuming the
// compression ratio is at most 16
#define MAX_COMPRESSION_RATIO (16)
// Protect against allocating too much memory for output
#define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024)
u8 *input;
u8 *output;
u8 *dict;
size_t read_file(const char *path, u8 **ptr) {
FILE *f = fopen(path, "rb");
if (!f) {
fprintf(stderr, "failed to open file %s\n", path);
exit(1);
}
fseek(f, 0L, SEEK_END);
size_t size = ftell(f);
rewind(f);
*ptr = malloc(size);
if (!ptr) {
fprintf(stderr, "failed to allocate memory to hold %s\n", path);
exit(1);
}
size_t pos = 0;
while (!feof(f)) {
size_t read = fread(&(*ptr)[pos], 1, size, f);
if (ferror(f)) {
fprintf(stderr, "error while reading file %s\n", path);
exit(1);
}
pos += read;
}
fclose(f);
return pos;
}
void write_file(const char *path, const u8 *ptr, size_t size) {
FILE *f = fopen(path, "wb");
size_t written = 0;
while (written < size) {
written += fwrite(&ptr[written], 1, size, f);
if (ferror(f)) {
fprintf(stderr, "error while writing file %s\n", path);
exit(1);
}
}
fclose(f);
}
int main(int argc, char **argv) {
if (argc < 3) {
fprintf(stderr, "usage: %s <file.zst> <out_path> [dictionary]\n",
argv[0]);
return 1;
}
size_t input_size = read_file(argv[1], &input);
size_t dict_size = 0;
if (argc >= 4) {
dict_size = read_file(argv[3], &dict);
}
size_t decompressed_size = ZSTD_get_decompressed_size(input, input_size);
if (decompressed_size == (size_t)-1) {
decompressed_size = MAX_COMPRESSION_RATIO * input_size;
fprintf(stderr, "WARNING: Compressed data does not contain "
"decompressed size, going to assume the compression "
"ratio is at most %d (decompressed size of at most "
"%zu)\n",
MAX_COMPRESSION_RATIO, decompressed_size);
}
if (decompressed_size > MAX_OUTPUT_SIZE) {
fprintf(stderr,
"Required output size too large for this implementation\n");
return 1;
}
output = malloc(decompressed_size);
if (!output) {
fprintf(stderr, "failed to allocate memory\n");
return 1;
}
dictionary_t* const parsed_dict = create_dictionary();
if (dict) {
parse_dictionary(parsed_dict, dict, dict_size);
}
size_t decompressed =
ZSTD_decompress_with_dict(output, decompressed_size,
input, input_size, parsed_dict);
free_dictionary(parsed_dict);
write_file(argv[2], output, decompressed);
free(input);
free(output);
free(dict);
input = output = dict = NULL;
}
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