1 /* 2 * Copyright (c) 2017-present, Facebook, Inc. 3 * All rights reserved. 4 * 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). 8 */ 9 10 #include <stdio.h> 11 #include <stdlib.h> 12 13 #include "zstd_decompress.h" 14 15 typedef unsigned char u8; 16 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) 20 21 // Protect against allocating too much memory for output 22 #define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024) 23 24 u8 *input; 25 u8 *output; 26 u8 *dict; 27 28 size_t read_file(const char *path, u8 **ptr) { 29 FILE *f = fopen(path, "rb"); 30 if (!f) { 31 fprintf(stderr, "failed to open file %s\n", path); 32 exit(1); 33 } 34 35 fseek(f, 0L, SEEK_END); 36 size_t size = ftell(f); 37 rewind(f); 38 39 *ptr = malloc(size); 40 if (!ptr) { 41 fprintf(stderr, "failed to allocate memory to hold %s\n", path); 42 exit(1); 43 } 44 45 size_t pos = 0; 46 while (!feof(f)) { 47 size_t read = fread(&(*ptr)[pos], 1, size, f); 48 if (ferror(f)) { 49 fprintf(stderr, "error while reading file %s\n", path); 50 exit(1); 51 } 52 pos += read; 53 } 54 55 fclose(f); 56 57 return pos; 58 } 59 60 void write_file(const char *path, const u8 *ptr, size_t size) { 61 FILE *f = fopen(path, "wb"); 62 63 size_t written = 0; 64 while (written < size) { 65 written += fwrite(&ptr[written], 1, size, f); 66 if (ferror(f)) { 67 fprintf(stderr, "error while writing file %s\n", path); 68 exit(1); 69 } 70 } 71 72 fclose(f); 73 } 74 75 int main(int argc, char **argv) { 76 if (argc < 3) { 77 fprintf(stderr, "usage: %s <file.zst> <out_path> [dictionary]\n", 78 argv[0]); 79 80 return 1; 81 } 82 83 size_t input_size = read_file(argv[1], &input); 84 size_t dict_size = 0; 85 if (argc >= 4) { 86 dict_size = read_file(argv[3], &dict); 87 } 88 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 " 95 "%zu)\n", 96 MAX_COMPRESSION_RATIO, decompressed_size); 97 } 98 if (decompressed_size > MAX_OUTPUT_SIZE) { 99 fprintf(stderr, 100 "Required output size too large for this implementation\n"); 101 return 1; 102 } 103 output = malloc(decompressed_size); 104 if (!output) { 105 fprintf(stderr, "failed to allocate memory\n"); 106 return 1; 107 } 108 109 dictionary_t* const parsed_dict = create_dictionary(); 110 if (dict) { 111 parse_dictionary(parsed_dict, dict, dict_size); 112 } 113 size_t decompressed = 114 ZSTD_decompress_with_dict(output, decompressed_size, 115 input, input_size, parsed_dict); 116 117 free_dictionary(parsed_dict); 118 119 write_file(argv[2], output, decompressed); 120 121 free(input); 122 free(output); 123 free(dict); 124 input = output = dict = NULL; 125 } 126