diff options
Diffstat (limited to 'examples/frameCompress.c')
| -rw-r--r-- | examples/frameCompress.c | 237 |
1 files changed, 138 insertions, 99 deletions
diff --git a/examples/frameCompress.c b/examples/frameCompress.c index d62053f..972f716 100644 --- a/examples/frameCompress.c +++ b/examples/frameCompress.c @@ -1,5 +1,5 @@ /* LZ4frame API example : compress a file - * Based on sample code from Zbigniew Jędrzejewski-Szmek + * Modified from an example code by Zbigniew Jędrzejewski-Szmek * * This example streams an input file into an output file * using a bounded memory budget. @@ -52,7 +52,7 @@ typedef struct { } compressResult_t; static compressResult_t -compress_file_internal(FILE* in, FILE* out, +compress_file_internal(FILE* f_in, FILE* f_out, LZ4F_compressionContext_t ctx, void* inBuff, size_t inChunkSize, void* outBuff, size_t outCapacity) @@ -60,6 +60,7 @@ compress_file_internal(FILE* in, FILE* out, 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)); @@ -72,13 +73,13 @@ compress_file_internal(FILE* in, FILE* out, } count_out = headerSize; printf("Buffer size is %zu bytes, header size %zu bytes\n", outCapacity, headerSize); - safe_fwrite(outBuff, 1, headerSize, out); + safe_fwrite(outBuff, 1, headerSize, f_out); } /* stream file */ for (;;) { - size_t const readSize = fread(inBuff, 1, IN_CHUNK_SIZE, in); - if (readSize == 0) break; + 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, @@ -91,21 +92,21 @@ compress_file_internal(FILE* in, FILE* out, } printf("Writing %zu bytes\n", compressedSize); - safe_fwrite(outBuff, 1, compressedSize, out); + 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); + 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, out); + safe_fwrite(outBuff, 1, compressedSize, f_out); count_out += compressedSize; } @@ -118,8 +119,6 @@ compress_file_internal(FILE* in, FILE* out, static compressResult_t compress_file(FILE* f_in, FILE* f_out) { - compressResult_t result = { 1, 0, 0 }; /* == error (default) */ - assert(f_in != NULL); assert(f_out != NULL); @@ -130,6 +129,7 @@ compress_file(FILE* f_in, FILE* f_out) 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, @@ -158,115 +158,152 @@ static size_t get_block_size(const LZ4F_frameInfo_t* info) { case LZ4F_max1MB: return 1 << 20; case LZ4F_max4MB: return 1 << 22; default: - printf("Impossible unless more block sizes are allowed\n"); + printf("Impossible with expected frame specification (<=v1.6.1)\n"); exit(1); } } -static size_t decompress_file(FILE* in, FILE* out) { - void* const src = malloc(IN_CHUNK_SIZE); - void* dst = NULL; - size_t dstCapacity = 0; - LZ4F_dctx* dctx = NULL; +/* @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; - /* Initialization */ - if (!src) { perror("decompress_file(src)"); goto cleanup; } - { size_t const dctxStatus = LZ4F_createDecompressionContext(&dctx, 100); - if (LZ4F_isError(dctxStatus)) { - printf("LZ4F_dctx creation error: %s\n", LZ4F_getErrorName(dctxStatus)); - goto cleanup; - } } + 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 srcSize = fread(src, 1, IN_CHUNK_SIZE, in); - const void* srcPtr = src; - const void* const srcEnd = srcPtr + srcSize; - if (srcSize == 0 || ferror(in)) { + size_t readSize = firstChunk ? filled : fread(src, 1, srcCapacity, f_in); firstChunk=0; + const void* srcPtr = src + alreadyConsumed; alreadyConsumed=0; + const void* const srcEnd = srcPtr + readSize; + if (readSize == 0 || ferror(f_in)) { printf("Decompress: not enough input or error reading file\n"); - goto cleanup; - } - /* Allocate destination buffer if it isn't already */ - if (!dst) { - LZ4F_frameInfo_t info; - ret = LZ4F_getFrameInfo(dctx, &info, src, &srcSize); - if (LZ4F_isError(ret)) { - printf("LZ4F_getFrameInfo error: %s\n", LZ4F_getErrorName(ret)); - goto cleanup; - } - /* Allocating enough space for an entire block isn't necessary for - * correctness, but it allows some memcpy's to be elided. - */ - dstCapacity = get_block_size(&info); - dst = malloc(dstCapacity); - if (!dst) { perror("decompress_file(dst)"); goto cleanup; } - srcPtr += srcSize; - srcSize = srcEnd - srcPtr; + return 1; } + /* Decompress: - * Continue while there is more input to read and the frame isn't over. - * If srcPtr == srcEnd then we know that there is no more output left in the - * internal buffer left to flush. + * Continue while there is more input to read (srcPtr != srcEnd) + * and the frame isn't over (ret != 0) */ while (srcPtr != srcEnd && ret != 0) { - /* INVARIANT: Any data left in dst has already been written */ + /* Any data within dst has been flushed at this stage */ size_t dstSize = dstCapacity; + size_t srcSize = srcEnd - 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)); - goto cleanup; + return 1; } /* Flush output */ - if (dstSize != 0){ - size_t written = fwrite(dst, 1, dstSize, out); - printf("Writing %zu bytes\n", dstSize); - if (written != dstSize) { - printf("Decompress: Failed to write to file\n"); - goto cleanup; - } - } + if (dstSize != 0) safe_fwrite(dst, 1, dstSize, f_out); /* Update input */ srcPtr += srcSize; - srcSize = srcEnd - srcPtr; } } + /* Check that there isn't trailing input data after the frame. - * It is valid to have multiple frames in the same file, but this example - * doesn't support it. + * It is valid to have multiple frames in the same file, + * but this example only supports one frame. */ - ret = fread(src, 1, 1, in); - if (ret != 0 || !feof(in)) { - printf("Decompress: Trailing data left in file after frame\n"); - goto cleanup; + { 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; } -cleanup: - free(src); + 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, + dst, dstCapacity); + free(dst); - return LZ4F_freeDecompressionContext(dctx); /* note : free works on NULL */ + 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, 100); + 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 compare(FILE* fp0, FILE* fp1) +int compareFiles(FILE* fp0, FILE* fp1) { int result = 0; - while(0 == result) { + while (result==0) { char b0[1024]; char b1[1024]; - const size_t r0 = fread(b0, 1, sizeof(b0), fp0); - const size_t r1 = fread(b1, 1, sizeof(b1), fp1); + size_t const r0 = fread(b0, 1, sizeof(b0), fp0); + size_t const r1 = fread(b1, 1, sizeof(b1), fp1); - result = (int) r0 - (int) r1; - - if (0 == r0 || 0 == r1) { - break; - } - if (0 == result) { - result = memcmp(b0, b1, r0); - } + result = (r0 != r1); + if (!r0 || !r1) break; + if (!result) result = memcmp(b0, b1, r0); } return result; @@ -278,7 +315,7 @@ int main(int argc, const char **argv) { char lz4Filename[256] = { 0 }; char decFilename[256] = { 0 }; - if(argc < 2) { + if (argc < 2) { printf("Please specify input filename\n"); return 0; } @@ -297,35 +334,36 @@ int main(int argc, const char **argv) { 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 */ + (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"); - - fclose(outFp); - fclose(inpFp); } /* decompress */ { FILE* const inpFp = fopen(lz4Filename, "rb"); FILE* const outFp = fopen(decFilename, "wb"); - size_t ret; printf("decompress : %s -> %s\n", lz4Filename, decFilename); - ret = decompress_file(inpFp, outFp); - if (ret) { - printf("decompress : failed with code %zu\n", ret); - return (int)ret; - } - printf("decompress : done\n"); + 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 */ @@ -333,15 +371,16 @@ int main(int argc, const char **argv) { FILE* const decFp = fopen(decFilename, "rb"); printf("verify : %s <-> %s\n", inpFilename, decFilename); - const int cmp = compare(inpFp, decFp); - if(0 == cmp) { - printf("verify : OK\n"); - } else { - printf("verify : NG\n"); - } + 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; |