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Diffstat (limited to 'examples/fileCompress.c')
| -rw-r--r-- | examples/fileCompress.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/examples/fileCompress.c b/examples/fileCompress.c new file mode 100644 index 00000000..4486ea8b --- /dev/null +++ b/examples/fileCompress.c @@ -0,0 +1,232 @@ +/* LZ4file API example : compress a file + * Modified from an example code by anjiahao + * + * This example will demonstrate how + * to manipulate lz4 compressed files like + * normal files */ + +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> + +#include <lz4file.h> + + +#define CHUNK_SIZE (16*1024) + +static size_t get_file_size(char *filename) +{ + struct stat statbuf; + + if (filename == NULL) { + return 0; + } + + if(stat(filename,&statbuf)) { + return 0; + } + + return statbuf.st_size; +} + +static int compress_file(FILE* f_in, FILE* f_out) +{ + assert(f_in != NULL); assert(f_out != NULL); + + LZ4F_errorCode_t ret = LZ4F_OK_NoError; + size_t len; + LZ4_writeFile_t* lz4fWrite; + void* const buf = malloc(CHUNK_SIZE); + if (!buf) { + printf("error: memory allocation failed \n"); + } + + /* Of course, you can also use prefsPtr to + * set the parameters of the compressed file + * NULL is use default + */ + ret = LZ4F_writeOpen(&lz4fWrite, f_out, NULL); + if (LZ4F_isError(ret)) { + printf("LZ4F_writeOpen error: %s\n", LZ4F_getErrorName(ret)); + free(buf); + return 1; + } + + while (1) { + len = fread(buf, 1, CHUNK_SIZE, f_in); + + if (ferror(f_in)) { + printf("fread error\n"); + goto out; + } + + /* nothing to read */ + if (len == 0) { + break; + } + + ret = LZ4F_write(lz4fWrite, buf, len); + if (LZ4F_isError(ret)) { + printf("LZ4F_write: %s\n", LZ4F_getErrorName(ret)); + goto out; + } + } + +out: + free(buf); + if (LZ4F_isError(LZ4F_writeClose(lz4fWrite))) { + printf("LZ4F_writeClose: %s\n", LZ4F_getErrorName(ret)); + return 1; + } + + return 0; +} + +static int decompress_file(FILE* f_in, FILE* f_out) +{ + assert(f_in != NULL); assert(f_out != NULL); + + LZ4F_errorCode_t ret = LZ4F_OK_NoError; + LZ4_readFile_t* lz4fRead; + void* const buf= malloc(CHUNK_SIZE); + if (!buf) { + printf("error: memory allocation failed \n"); + } + + ret = LZ4F_readOpen(&lz4fRead, f_in); + if (LZ4F_isError(ret)) { + printf("LZ4F_readOpen error: %s\n", LZ4F_getErrorName(ret)); + free(buf); + return 1; + } + + while (1) { + ret = LZ4F_read(lz4fRead, buf, CHUNK_SIZE); + if (LZ4F_isError(ret)) { + printf("LZ4F_read error: %s\n", LZ4F_getErrorName(ret)); + goto out; + } + + /* nothing to read */ + if (ret == 0) { + break; + } + + if(fwrite(buf, 1, ret, f_out) != ret) { + printf("write error!\n"); + goto out; + } + } + +out: + free(buf); + if (LZ4F_isError(LZ4F_readClose(lz4fRead))) { + printf("LZ4F_readClose: %s\n", LZ4F_getErrorName(ret)); + return 1; + } + + if (ret) { + return 1; + } + + return 0; +} + +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); + LZ4F_errorCode_t ret = compress_file(inpFp, outFp); + fclose(inpFp); + fclose(outFp); + + if (ret) { + printf("compression error: %s\n", LZ4F_getErrorName(ret)); + return 1; + } + + printf("%s: %zu → %zu bytes, %.1f%%\n", + inpFilename, + get_file_size(inpFilename), + get_file_size(lz4Filename), /* might overflow is size_t is 32 bits and size_{in,out} > 4 GB */ + (double)get_file_size(lz4Filename) / get_file_size(inpFilename) * 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); + LZ4F_errorCode_t ret = decompress_file(inpFp, outFp); + + fclose(outFp); + fclose(inpFp); + + if (ret) { + printf("compression error: %s\n", LZ4F_getErrorName(ret)); + return 1; + } + + 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"); + } + +} |