1 /*
2 * Copyright (c) 2017-2020, 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 * 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
freeBuffer(buffer_s b)34 static void freeBuffer(buffer_s b) { free(b.address); }
35
read_file(const char * path)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
write_file(const char * path,const u8 * ptr,size_t size)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
main(int argc,char ** argv)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 }
120