| /* |
| * Copyright (c) 2016-2021, 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). |
| * You may select, at your option, one of the above-listed licenses. |
| */ |
| |
| #include <string.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #define ZSTD_STATIC_LINKING_ONLY |
| #include "util.h" |
| #include "zstd.h" |
| |
| #define CHECK(cond, ...) \ |
| do { \ |
| if (!(cond)) { \ |
| fprintf(stderr, "%s:%d CHECK(%s) failed: ", __FILE__, __LINE__, #cond); \ |
| fprintf(stderr, "" __VA_ARGS__); \ |
| fprintf(stderr, "\n"); \ |
| exit(1); \ |
| } \ |
| } while (0) |
| |
| static void usage(char const *program) { |
| fprintf(stderr, "USAGE: %s FILE.zst PREFIX\n", program); |
| fprintf(stderr, "FILE.zst: A zstd compressed file with multiple frames\n"); |
| fprintf(stderr, "PREFIX: The output prefix. Uncompressed files will be " |
| "created named ${PREFIX}0 ${PREFIX}1...\n\n"); |
| fprintf(stderr, "This program takes concatenated zstd frames and " |
| "decompresses them into individual files.\n"); |
| fprintf(stderr, "E.g. files created with a command like: zstd -r directory " |
| "-o file.zst\n"); |
| } |
| |
| typedef struct { |
| char *data; |
| size_t size; |
| size_t frames; |
| size_t maxFrameSize; |
| } ZstdFrames; |
| |
| static ZstdFrames readFile(char const *fileName) { |
| U64 const fileSize = UTIL_getFileSize(fileName); |
| CHECK(fileSize != UTIL_FILESIZE_UNKNOWN, "Unknown file size!"); |
| |
| char *const data = (char *)malloc(fileSize); |
| CHECK(data != NULL, "Allocation failed"); |
| |
| FILE *file = fopen(fileName, "rb"); |
| CHECK(file != NULL, "fopen failed"); |
| |
| size_t const readSize = fread(data, 1, fileSize, file); |
| CHECK(readSize == fileSize, "fread failed"); |
| |
| fclose(file); |
| ZstdFrames frames; |
| frames.data = (char *)data; |
| frames.size = fileSize; |
| frames.frames = 0; |
| |
| size_t index; |
| size_t maxFrameSize = 0; |
| for (index = 0; index < fileSize;) { |
| size_t const frameSize = |
| ZSTD_findFrameCompressedSize(data + index, fileSize - index); |
| CHECK(!ZSTD_isError(frameSize), "Bad zstd frame: %s", |
| ZSTD_getErrorName(frameSize)); |
| if (frameSize > maxFrameSize) |
| maxFrameSize = frameSize; |
| frames.frames += 1; |
| index += frameSize; |
| } |
| CHECK(index == fileSize, "Zstd file corrupt!"); |
| frames.maxFrameSize = maxFrameSize; |
| |
| return frames; |
| } |
| |
| static int computePadding(size_t numFrames) { |
| return snprintf(NULL, 0, "%u", (unsigned)numFrames); |
| } |
| |
| int main(int argc, char **argv) { |
| if (argc != 3) { |
| usage(argv[0]); |
| exit(1); |
| } |
| char const *const zstdFile = argv[1]; |
| char const *const prefix = argv[2]; |
| |
| ZstdFrames frames = readFile(zstdFile); |
| |
| if (frames.frames <= 1) { |
| fprintf( |
| stderr, |
| "%s only has %u zstd frame. Simply use `zstd -d` to decompress it.\n", |
| zstdFile, (unsigned)frames.frames); |
| exit(1); |
| } |
| |
| int const padding = computePadding(frames.frames - 1); |
| |
| size_t const outFileNameSize = strlen(prefix) + padding + 1; |
| char* outFileName = malloc(outFileNameSize); |
| CHECK(outFileName != NULL, "Allocation failure"); |
| |
| size_t const bufferSize = 128 * 1024; |
| void *buffer = malloc(bufferSize); |
| CHECK(buffer != NULL, "Allocation failure"); |
| |
| ZSTD_DCtx* dctx = ZSTD_createDCtx(); |
| CHECK(dctx != NULL, "Allocation failure"); |
| |
| fprintf(stderr, "Recovering %u files...\n", (unsigned)frames.frames); |
| |
| size_t index; |
| size_t frame = 0; |
| for (index = 0; index < frames.size; ++frame) { |
| size_t const frameSize = |
| ZSTD_findFrameCompressedSize(frames.data + index, frames.size - index); |
| |
| int const ret = snprintf(outFileName, outFileNameSize, "%s%0*u", prefix, padding, (unsigned)frame); |
| CHECK(ret >= 0 && (size_t)ret <= outFileNameSize, "snprintf failed!"); |
| |
| FILE* outFile = fopen(outFileName, "wb"); |
| CHECK(outFile != NULL, "fopen failed"); |
| |
| ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only); |
| ZSTD_inBuffer in = {frames.data + index, frameSize, 0}; |
| while (in.pos < in.size) { |
| ZSTD_outBuffer out = {buffer, bufferSize, 0}; |
| CHECK(!ZSTD_isError(ZSTD_decompressStream(dctx, &out, &in)), "decompression failed"); |
| size_t const writeSize = fwrite(out.dst, 1, out.pos, outFile); |
| CHECK(writeSize == out.pos, "fwrite failed"); |
| } |
| fclose(outFile); |
| fprintf(stderr, "Recovered %s\n", outFileName); |
| index += frameSize; |
| } |
| fprintf(stderr, "Complete\n"); |
| |
| free(outFileName); |
| ZSTD_freeDCtx(dctx); |
| free(buffer); |
| free(frames.data); |
| return 0; |
| } |