2 * Copyright (c) 2017-present, Facebook, Inc.
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
13 #include "zstd_decompress.h"
15 typedef unsigned char u8;
17 // If the data doesn't have decompressed size with it, fallback on assuming the
18 // compression ratio is at most 16
19 #define MAX_COMPRESSION_RATIO (16)
21 // Protect against allocating too much memory for output
22 #define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024)
28 size_t read_file(const char *path, u8 **ptr) {
29 FILE *f = fopen(path, "rb");
31 fprintf(stderr, "failed to open file %s\n", path);
35 fseek(f, 0L, SEEK_END);
36 size_t size = ftell(f);
41 fprintf(stderr, "failed to allocate memory to hold %s\n", path);
47 size_t read = fread(&(*ptr)[pos], 1, size, f);
49 fprintf(stderr, "error while reading file %s\n", path);
60 void write_file(const char *path, const u8 *ptr, size_t size) {
61 FILE *f = fopen(path, "wb");
64 while (written < size) {
65 written += fwrite(&ptr[written], 1, size, f);
67 fprintf(stderr, "error while writing file %s\n", path);
75 int main(int argc, char **argv) {
77 fprintf(stderr, "usage: %s <file.zst> <out_path> [dictionary]\n",
83 size_t input_size = read_file(argv[1], &input);
86 dict_size = read_file(argv[3], &dict);
89 size_t decompressed_size = ZSTD_get_decompressed_size(input, input_size);
90 if (decompressed_size == (size_t)-1) {
91 decompressed_size = MAX_COMPRESSION_RATIO * input_size;
92 fprintf(stderr, "WARNING: Compressed data does not contain "
93 "decompressed size, going to assume the compression "
94 "ratio is at most %d (decompressed size of at most "
96 MAX_COMPRESSION_RATIO, decompressed_size);
98 if (decompressed_size > MAX_OUTPUT_SIZE) {
100 "Required output size too large for this implementation\n");
103 output = malloc(decompressed_size);
105 fprintf(stderr, "failed to allocate memory\n");
109 dictionary_t* const parsed_dict = create_dictionary();
111 parse_dictionary(parsed_dict, dict, dict_size);
113 size_t decompressed =
114 ZSTD_decompress_with_dict(output, decompressed_size,
115 input, input_size, parsed_dict);
117 free_dictionary(parsed_dict);
119 write_file(argv[2], output, decompressed);
124 input = output = dict = NULL;