139 lines
3.8 KiB
C
139 lines
3.8 KiB
C
/*
|
|
* 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 <stdlib.h> // malloc, exit
|
|
#include <stdio.h> // fprintf, perror, feof
|
|
#include <string.h> // strerror
|
|
#include <errno.h> // errno
|
|
#define ZSTD_STATIC_LINKING_ONLY
|
|
#include <zstd.h> // presumes zstd library is installed
|
|
#include <zstd_errors.h>
|
|
|
|
#include "zstd_seekable.h"
|
|
|
|
#define MIN(a, b) ((a) < (b) ? (a) : (b))
|
|
|
|
static void* malloc_orDie(size_t size)
|
|
{
|
|
void* const buff = malloc(size);
|
|
if (buff) return buff;
|
|
/* error */
|
|
perror("malloc");
|
|
exit(1);
|
|
}
|
|
|
|
static void* realloc_orDie(void* ptr, size_t size)
|
|
{
|
|
ptr = realloc(ptr, size);
|
|
if (ptr) return ptr;
|
|
/* error */
|
|
perror("realloc");
|
|
exit(1);
|
|
}
|
|
|
|
static FILE* fopen_orDie(const char *filename, const char *instruction)
|
|
{
|
|
FILE* const inFile = fopen(filename, instruction);
|
|
if (inFile) return inFile;
|
|
/* error */
|
|
perror(filename);
|
|
exit(3);
|
|
}
|
|
|
|
static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
|
|
{
|
|
size_t const readSize = fread(buffer, 1, sizeToRead, file);
|
|
if (readSize == sizeToRead) return readSize; /* good */
|
|
if (feof(file)) return readSize; /* good, reached end of file */
|
|
/* error */
|
|
perror("fread");
|
|
exit(4);
|
|
}
|
|
|
|
static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
|
|
{
|
|
size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
|
|
if (writtenSize == sizeToWrite) return sizeToWrite; /* good */
|
|
/* error */
|
|
perror("fwrite");
|
|
exit(5);
|
|
}
|
|
|
|
static size_t fclose_orDie(FILE* file)
|
|
{
|
|
if (!fclose(file)) return 0;
|
|
/* error */
|
|
perror("fclose");
|
|
exit(6);
|
|
}
|
|
|
|
static void fseek_orDie(FILE* file, long int offset, int origin) {
|
|
if (!fseek(file, offset, origin)) {
|
|
if (!fflush(file)) return;
|
|
}
|
|
/* error */
|
|
perror("fseek");
|
|
exit(7);
|
|
}
|
|
|
|
|
|
static void decompressFile_orDie(const char* fname, off_t startOffset, off_t endOffset)
|
|
{
|
|
FILE* const fin = fopen_orDie(fname, "rb");
|
|
FILE* const fout = stdout;
|
|
size_t const buffOutSize = ZSTD_DStreamOutSize(); /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */
|
|
void* const buffOut = malloc_orDie(buffOutSize);
|
|
|
|
ZSTD_seekable* const seekable = ZSTD_seekable_create();
|
|
if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); }
|
|
|
|
size_t const initResult = ZSTD_seekable_initFile(seekable, fin);
|
|
if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
|
|
|
|
while (startOffset < endOffset) {
|
|
size_t const result = ZSTD_seekable_decompress(seekable, buffOut, MIN(endOffset - startOffset, buffOutSize), startOffset);
|
|
|
|
if (ZSTD_isError(result)) {
|
|
fprintf(stderr, "ZSTD_seekable_decompress() error : %s \n",
|
|
ZSTD_getErrorName(result));
|
|
exit(12);
|
|
}
|
|
fwrite_orDie(buffOut, result, fout);
|
|
startOffset += result;
|
|
}
|
|
|
|
ZSTD_seekable_free(seekable);
|
|
fclose_orDie(fin);
|
|
fclose_orDie(fout);
|
|
free(buffOut);
|
|
}
|
|
|
|
|
|
int main(int argc, const char** argv)
|
|
{
|
|
const char* const exeName = argv[0];
|
|
|
|
if (argc!=4) {
|
|
fprintf(stderr, "wrong arguments\n");
|
|
fprintf(stderr, "usage:\n");
|
|
fprintf(stderr, "%s FILE START END\n", exeName);
|
|
return 1;
|
|
}
|
|
|
|
{
|
|
const char* const inFilename = argv[1];
|
|
off_t const startOffset = atoll(argv[2]);
|
|
off_t const endOffset = atoll(argv[3]);
|
|
decompressFile_orDie(inFilename, startOffset, endOffset);
|
|
}
|
|
|
|
return 0;
|
|
}
|