| /* LZ4frame API example : compress a file |
| * Modified from an example code by Zbigniew Jędrzejewski-Szmek |
| * |
| * This example streams an input file into an output file |
| * using a bounded memory budget. |
| * Input is read in chunks of IN_CHUNK_SIZE */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <assert.h> |
| |
| #include <lz4frame.h> |
| |
| |
| #define IN_CHUNK_SIZE (16*1024) |
| |
| static const LZ4F_preferences_t kPrefs = { |
| { LZ4F_max256KB, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame, |
| 0 /* unknown content size */, 0 /* no dictID */ , LZ4F_noBlockChecksum }, |
| 0, /* compression level; 0 == default */ |
| 0, /* autoflush */ |
| 0, /* favor decompression speed */ |
| { 0, 0, 0 }, /* reserved, must be set to 0 */ |
| }; |
| |
| |
| /* safe_fwrite() : |
| * performs fwrite(), ensure operation success, or immediately exit() */ |
| static void safe_fwrite(void* buf, size_t eltSize, size_t nbElt, FILE* f) |
| { |
| size_t const writtenSize = fwrite(buf, eltSize, nbElt, f); |
| size_t const expectedSize = eltSize * nbElt; |
| assert(expectedSize / nbElt == eltSize); /* check overflow */ |
| if (writtenSize < expectedSize) { |
| if (ferror(f)) /* note : ferror() must follow fwrite */ |
| fprintf(stderr, "Write failed \n"); |
| else |
| fprintf(stderr, "Short write \n"); |
| exit(1); |
| } |
| } |
| |
| |
| /* ================================================= */ |
| /* Streaming Compression example */ |
| /* ================================================= */ |
| |
| typedef struct { |
| int error; |
| unsigned long long size_in; |
| unsigned long long size_out; |
| } compressResult_t; |
| |
| static compressResult_t |
| compress_file_internal(FILE* f_in, FILE* f_out, |
| LZ4F_compressionContext_t ctx, |
| void* inBuff, size_t inChunkSize, |
| void* outBuff, size_t outCapacity) |
| { |
| compressResult_t result = { 1, 0, 0 }; /* result for an error */ |
| unsigned long long count_in = 0, count_out; |
| |
| assert(f_in != NULL); assert(f_out != NULL); |
| assert(ctx != NULL); |
| assert(outCapacity >= LZ4F_HEADER_SIZE_MAX); |
| assert(outCapacity >= LZ4F_compressBound(inChunkSize, &kPrefs)); |
| |
| /* write frame header */ |
| { size_t const headerSize = LZ4F_compressBegin(ctx, outBuff, outCapacity, &kPrefs); |
| if (LZ4F_isError(headerSize)) { |
| printf("Failed to start compression: error %zu\n", headerSize); |
| return result; |
| } |
| count_out = headerSize; |
| printf("Buffer size is %zu bytes, header size %zu bytes\n", outCapacity, headerSize); |
| safe_fwrite(outBuff, 1, headerSize, f_out); |
| } |
| |
| /* stream file */ |
| for (;;) { |
| size_t const readSize = fread(inBuff, 1, IN_CHUNK_SIZE, f_in); |
| if (readSize == 0) break; /* nothing left to read from input file */ |
| count_in += readSize; |
| |
| size_t const compressedSize = LZ4F_compressUpdate(ctx, |
| outBuff, outCapacity, |
| inBuff, readSize, |
| NULL); |
| if (LZ4F_isError(compressedSize)) { |
| printf("Compression failed: error %zu\n", compressedSize); |
| return result; |
| } |
| |
| printf("Writing %zu bytes\n", compressedSize); |
| safe_fwrite(outBuff, 1, compressedSize, f_out); |
| count_out += compressedSize; |
| } |
| |
| /* flush whatever remains within internal buffers */ |
| { size_t const compressedSize = LZ4F_compressEnd(ctx, |
| outBuff, outCapacity, |
| NULL); |
| if (LZ4F_isError(compressedSize)) { |
| printf("Failed to end compression: error %zu\n", compressedSize); |
| return result; |
| } |
| |
| printf("Writing %zu bytes\n", compressedSize); |
| safe_fwrite(outBuff, 1, compressedSize, f_out); |
| count_out += compressedSize; |
| } |
| |
| result.size_in = count_in; |
| result.size_out = count_out; |
| result.error = 0; |
| return result; |
| } |
| |
| static compressResult_t |
| compress_file(FILE* f_in, FILE* f_out) |
| { |
| assert(f_in != NULL); |
| assert(f_out != NULL); |
| |
| /* ressource allocation */ |
| LZ4F_compressionContext_t ctx; |
| size_t const ctxCreation = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION); |
| void* const src = malloc(IN_CHUNK_SIZE); |
| size_t const outbufCapacity = LZ4F_compressBound(IN_CHUNK_SIZE, &kPrefs); /* large enough for any input <= IN_CHUNK_SIZE */ |
| void* const outbuff = malloc(outbufCapacity); |
| |
| compressResult_t result = { 1, 0, 0 }; /* == error (default) */ |
| if (!LZ4F_isError(ctxCreation) && src && outbuff) { |
| result = compress_file_internal(f_in, f_out, |
| ctx, |
| src, IN_CHUNK_SIZE, |
| outbuff, outbufCapacity); |
| } else { |
| printf("error : ressource allocation failed \n"); |
| } |
| |
| LZ4F_freeCompressionContext(ctx); /* supports free on NULL */ |
| free(src); |
| free(outbuff); |
| return result; |
| } |
| |
| |
| /* ================================================= */ |
| /* Streaming decompression example */ |
| /* ================================================= */ |
| |
| static size_t get_block_size(const LZ4F_frameInfo_t* info) { |
| switch (info->blockSizeID) { |
| case LZ4F_default: |
| case LZ4F_max64KB: return 1 << 16; |
| case LZ4F_max256KB: return 1 << 18; |
| case LZ4F_max1MB: return 1 << 20; |
| case LZ4F_max4MB: return 1 << 22; |
| default: |
| printf("Impossible with expected frame specification (<=v1.6.1)\n"); |
| exit(1); |
| } |
| } |
| |
| /* @return : 1==error, 0==success */ |
| static int |
| decompress_file_internal(FILE* f_in, FILE* f_out, |
| LZ4F_dctx* dctx, |
| void* src, size_t srcCapacity, size_t filled, size_t alreadyConsumed, |
| void* dst, size_t dstCapacity) |
| { |
| int firstChunk = 1; |
| size_t ret = 1; |
| |
| assert(f_in != NULL); assert(f_out != NULL); |
| assert(dctx != NULL); |
| assert(src != NULL); assert(srcCapacity > 0); assert(filled <= srcCapacity); assert(alreadyConsumed <= filled); |
| assert(dst != NULL); assert(dstCapacity > 0); |
| |
| /* Decompression */ |
| while (ret != 0) { |
| /* Load more input */ |
| size_t readSize = firstChunk ? filled : fread(src, 1, srcCapacity, f_in); firstChunk=0; |
| const void* srcPtr = (const char*)src + alreadyConsumed; alreadyConsumed=0; |
| const void* const srcEnd = (const char*)srcPtr + readSize; |
| if (readSize == 0 || ferror(f_in)) { |
| printf("Decompress: not enough input or error reading file\n"); |
| return 1; |
| } |
| |
| /* Decompress: |
| * Continue while there is more input to read (srcPtr != srcEnd) |
| * and the frame isn't over (ret != 0) |
| */ |
| while (srcPtr < srcEnd && ret != 0) { |
| /* Any data within dst has been flushed at this stage */ |
| size_t dstSize = dstCapacity; |
| size_t srcSize = (const char*)srcEnd - (const char*)srcPtr; |
| ret = LZ4F_decompress(dctx, dst, &dstSize, srcPtr, &srcSize, /* LZ4F_decompressOptions_t */ NULL); |
| if (LZ4F_isError(ret)) { |
| printf("Decompression error: %s\n", LZ4F_getErrorName(ret)); |
| return 1; |
| } |
| /* Flush output */ |
| if (dstSize != 0) safe_fwrite(dst, 1, dstSize, f_out); |
| /* Update input */ |
| srcPtr = (const char*)srcPtr + srcSize; |
| } |
| |
| assert(srcPtr <= srcEnd); |
| |
| /* Ensure all input data has been consumed. |
| * It is valid to have multiple frames in the same file, |
| * but this example only supports one frame. |
| */ |
| if (srcPtr < srcEnd) { |
| printf("Decompress: Trailing data left in file after frame\n"); |
| return 1; |
| } |
| } |
| |
| /* Check that there isn't trailing data in the file after the frame. |
| * It is valid to have multiple frames in the same file, |
| * but this example only supports one frame. |
| */ |
| { size_t const readSize = fread(src, 1, 1, f_in); |
| if (readSize != 0 || !feof(f_in)) { |
| printf("Decompress: Trailing data left in file after frame\n"); |
| return 1; |
| } } |
| |
| return 0; |
| } |
| |
| |
| /* @return : 1==error, 0==completed */ |
| static int |
| decompress_file_allocDst(FILE* f_in, FILE* f_out, |
| LZ4F_dctx* dctx, |
| void* src, size_t srcCapacity) |
| { |
| assert(f_in != NULL); assert(f_out != NULL); |
| assert(dctx != NULL); |
| assert(src != NULL); |
| assert(srcCapacity >= LZ4F_HEADER_SIZE_MAX); /* ensure LZ4F_getFrameInfo() can read enough data */ |
| |
| /* Read Frame header */ |
| size_t const readSize = fread(src, 1, srcCapacity, f_in); |
| if (readSize == 0 || ferror(f_in)) { |
| printf("Decompress: not enough input or error reading file\n"); |
| return 1; |
| } |
| |
| LZ4F_frameInfo_t info; |
| size_t consumedSize = readSize; |
| { size_t const fires = LZ4F_getFrameInfo(dctx, &info, src, &consumedSize); |
| if (LZ4F_isError(fires)) { |
| printf("LZ4F_getFrameInfo error: %s\n", LZ4F_getErrorName(fires)); |
| return 1; |
| } } |
| |
| /* Allocating enough space for an entire block isn't necessary for |
| * correctness, but it allows some memcpy's to be elided. |
| */ |
| size_t const dstCapacity = get_block_size(&info); |
| void* const dst = malloc(dstCapacity); |
| if (!dst) { perror("decompress_file(dst)"); return 1; } |
| |
| int const decompressionResult = decompress_file_internal( |
| f_in, f_out, |
| dctx, |
| src, srcCapacity, readSize-consumedSize, consumedSize, |
| dst, dstCapacity); |
| |
| free(dst); |
| return decompressionResult; |
| } |
| |
| |
| /* @result : 1==error, 0==success */ |
| static int decompress_file(FILE* f_in, FILE* f_out) |
| { |
| assert(f_in != NULL); assert(f_out != NULL); |
| |
| /* Ressource allocation */ |
| void* const src = malloc(IN_CHUNK_SIZE); |
| if (!src) { perror("decompress_file(src)"); return 1; } |
| |
| LZ4F_dctx* dctx; |
| { size_t const dctxStatus = LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION); |
| if (LZ4F_isError(dctxStatus)) { |
| printf("LZ4F_dctx creation error: %s\n", LZ4F_getErrorName(dctxStatus)); |
| } } |
| |
| int const result = !dctx ? 1 /* error */ : |
| decompress_file_allocDst(f_in, f_out, dctx, src, IN_CHUNK_SIZE); |
| |
| free(src); |
| LZ4F_freeDecompressionContext(dctx); /* note : free works on NULL */ |
| return result; |
| } |
| |
| |
| int compareFiles(FILE* fp0, FILE* fp1) |
| { |
| int result = 0; |
| |
| while (result==0) { |
| char b0[1024]; |
| char b1[1024]; |
| size_t const r0 = fread(b0, 1, sizeof(b0), fp0); |
| size_t const r1 = fread(b1, 1, sizeof(b1), fp1); |
| |
| result = (r0 != r1); |
| if (!r0 || !r1) break; |
| if (!result) result = memcmp(b0, b1, r0); |
| } |
| |
| return result; |
| } |
| |
| |
| int main(int argc, const char **argv) { |
| char inpFilename[256] = { 0 }; |
| char lz4Filename[256] = { 0 }; |
| char decFilename[256] = { 0 }; |
| |
| if (argc < 2) { |
| printf("Please specify input filename\n"); |
| return 0; |
| } |
| |
| snprintf(inpFilename, 256, "%s", argv[1]); |
| snprintf(lz4Filename, 256, "%s.lz4", argv[1]); |
| snprintf(decFilename, 256, "%s.lz4.dec", argv[1]); |
| |
| printf("inp = [%s]\n", inpFilename); |
| printf("lz4 = [%s]\n", lz4Filename); |
| printf("dec = [%s]\n", decFilename); |
| |
| /* compress */ |
| { FILE* const inpFp = fopen(inpFilename, "rb"); |
| FILE* const outFp = fopen(lz4Filename, "wb"); |
| |
| printf("compress : %s -> %s\n", inpFilename, lz4Filename); |
| compressResult_t const ret = compress_file(inpFp, outFp); |
| |
| fclose(outFp); |
| fclose(inpFp); |
| |
| if (ret.error) { |
| printf("compress : failed with code %i\n", ret.error); |
| return ret.error; |
| } |
| printf("%s: %zu → %zu bytes, %.1f%%\n", |
| inpFilename, |
| (size_t)ret.size_in, (size_t)ret.size_out, /* might overflow is size_t is 32 bits and size_{in,out} > 4 GB */ |
| (double)ret.size_out / ret.size_in * 100); |
| printf("compress : done\n"); |
| } |
| |
| /* decompress */ |
| { FILE* const inpFp = fopen(lz4Filename, "rb"); |
| FILE* const outFp = fopen(decFilename, "wb"); |
| |
| printf("decompress : %s -> %s\n", lz4Filename, decFilename); |
| int const ret = decompress_file(inpFp, outFp); |
| |
| fclose(outFp); |
| fclose(inpFp); |
| |
| if (ret) { |
| printf("decompress : failed with code %i\n", ret); |
| return ret; |
| } |
| printf("decompress : done\n"); |
| } |
| |
| /* verify */ |
| { FILE* const inpFp = fopen(inpFilename, "rb"); |
| FILE* const decFp = fopen(decFilename, "rb"); |
| |
| printf("verify : %s <-> %s\n", inpFilename, decFilename); |
| int const cmp = compareFiles(inpFp, decFp); |
| |
| fclose(decFp); |
| fclose(inpFp); |
| |
| if (cmp) { |
| printf("corruption detected : decompressed file differs from original\n"); |
| return cmp; |
| } |
| printf("verify : OK\n"); |
| } |
| |
| return 0; |
| } |