| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 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 | * You may select, at your option, one of the above-listed licenses. |
| 9 | */ |
| 10 | |
| 11 | #include <stdio.h> |
| 12 | #include <stdlib.h> |
| 13 | |
| 14 | #include "zstd_decompress.h" |
| 15 | |
| 16 | typedef unsigned char u8; |
| 17 | |
| 18 | // If the data doesn't have decompressed size with it, fallback on assuming the |
| 19 | // compression ratio is at most 16 |
| 20 | #define MAX_COMPRESSION_RATIO (16) |
| 21 | |
| 22 | // Protect against allocating too much memory for output |
| 23 | #define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024) |
| 24 | |
| 25 | // Error message then exit |
| 26 | #define ERR_OUT(...) { fprintf(stderr, __VA_ARGS__); exit(1); } |
| 27 | |
| 28 | |
| 29 | typedef struct { |
| 30 | u8* address; |
| 31 | size_t size; |
| 32 | } buffer_s; |
| 33 | |
| 34 | static void freeBuffer(buffer_s b) { free(b.address); } |
| 35 | |
| 36 | static buffer_s read_file(const char *path) |
| 37 | { |
| 38 | FILE* const f = fopen(path, "rb"); |
| 39 | if (!f) ERR_OUT("failed to open file %s \n", path); |
| 40 | |
| 41 | fseek(f, 0L, SEEK_END); |
| 42 | size_t const size = (size_t)ftell(f); |
| 43 | rewind(f); |
| 44 | |
| 45 | void* const ptr = malloc(size); |
| 46 | if (!ptr) ERR_OUT("failed to allocate memory to hold %s \n", path); |
| 47 | |
| 48 | size_t const read = fread(ptr, 1, size, f); |
| 49 | if (read != size) ERR_OUT("error while reading file %s \n", path); |
| 50 | |
| 51 | fclose(f); |
| 52 | buffer_s const b = { ptr, size }; |
| 53 | return b; |
| 54 | } |
| 55 | |
| 56 | static void write_file(const char* path, const u8* ptr, size_t size) |
| 57 | { |
| 58 | FILE* const f = fopen(path, "wb"); |
| 59 | if (!f) ERR_OUT("failed to open file %s \n", path); |
| 60 | |
| 61 | size_t written = 0; |
| 62 | while (written < size) { |
| 63 | written += fwrite(ptr+written, 1, size, f); |
| 64 | if (ferror(f)) ERR_OUT("error while writing file %s\n", path); |
| 65 | } |
| 66 | |
| 67 | fclose(f); |
| 68 | } |
| 69 | |
| 70 | int main(int argc, char **argv) |
| 71 | { |
| 72 | if (argc < 3) |
| 73 | ERR_OUT("usage: %s <file.zst> <out_path> [dictionary] \n", argv[0]); |
| 74 | |
| 75 | buffer_s const input = read_file(argv[1]); |
| 76 | |
| 77 | buffer_s dict = { NULL, 0 }; |
| 78 | if (argc >= 4) { |
| 79 | dict = read_file(argv[3]); |
| 80 | } |
| 81 | |
| 82 | size_t out_capacity = ZSTD_get_decompressed_size(input.address, input.size); |
| 83 | if (out_capacity == (size_t)-1) { |
| 84 | out_capacity = MAX_COMPRESSION_RATIO * input.size; |
| 85 | fprintf(stderr, "WARNING: Compressed data does not contain " |
| 86 | "decompressed size, going to assume the compression " |
| 87 | "ratio is at most %d (decompressed size of at most " |
| 88 | "%u) \n", |
| 89 | MAX_COMPRESSION_RATIO, (unsigned)out_capacity); |
| 90 | } |
| 91 | if (out_capacity > MAX_OUTPUT_SIZE) |
| 92 | ERR_OUT("Required output size too large for this implementation \n"); |
| 93 | |
| 94 | u8* const output = malloc(out_capacity); |
| 95 | if (!output) ERR_OUT("failed to allocate memory \n"); |
| 96 | |
| 97 | dictionary_t* const parsed_dict = create_dictionary(); |
| 98 | if (dict.size) { |
| 99 | #if defined (ZDEC_NO_DICTIONARY) |
| 100 | printf("dict.size = %zu \n", dict.size); |
| 101 | ERR_OUT("no dictionary support \n"); |
| 102 | #else |
| 103 | parse_dictionary(parsed_dict, dict.address, dict.size); |
| 104 | #endif |
| 105 | } |
| 106 | size_t const decompressed_size = |
| 107 | ZSTD_decompress_with_dict(output, out_capacity, |
| 108 | input.address, input.size, |
| 109 | parsed_dict); |
| 110 | |
| 111 | free_dictionary(parsed_dict); |
| 112 | |
| 113 | write_file(argv[2], output, decompressed_size); |
| 114 | |
| 115 | freeBuffer(input); |
| 116 | freeBuffer(dict); |
| 117 | free(output); |
| 118 | return 0; |
| 119 | } |