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rust-rocksdb/librocksdb-sys/lz4/examples/blockStreaming_doubleBuffer.c

202 lines
4.7 KiB

// LZ4 streaming API example : double buffer
// Copyright : Takayuki Matsuoka
#if defined(_MSC_VER) && (_MSC_VER <= 1800) /* Visual Studio <= 2013 */
# define _CRT_SECURE_NO_WARNINGS
# define snprintf sprintf_s
#endif
#include "lz4.h"
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
enum {
BLOCK_BYTES = 1024 * 8,
// BLOCK_BYTES = 1024 * 64,
};
size_t write_int(FILE* fp, int i) {
return fwrite(&i, sizeof(i), 1, fp);
}
size_t write_bin(FILE* fp, const void* array, size_t arrayBytes) {
return fwrite(array, 1, arrayBytes, fp);
}
size_t read_int(FILE* fp, int* i) {
return fread(i, sizeof(*i), 1, fp);
}
size_t read_bin(FILE* fp, void* array, size_t arrayBytes) {
return fread(array, 1, arrayBytes, fp);
}
void test_compress(FILE* outFp, FILE* inpFp)
{
LZ4_stream_t lz4Stream_body;
LZ4_stream_t* lz4Stream = &lz4Stream_body;
char inpBuf[2][BLOCK_BYTES];
int inpBufIndex = 0;
LZ4_initStream(lz4Stream, sizeof (*lz4Stream));
for(;;) {
char* const inpPtr = inpBuf[inpBufIndex];
const int inpBytes = (int) read_bin(inpFp, inpPtr, BLOCK_BYTES);
if(0 == inpBytes) {
break;
}
{
char cmpBuf[LZ4_COMPRESSBOUND(BLOCK_BYTES)];
const int cmpBytes = LZ4_compress_fast_continue(
lz4Stream, inpPtr, cmpBuf, inpBytes, sizeof(cmpBuf), 1);
if(cmpBytes <= 0) {
break;
}
write_int(outFp, cmpBytes);
write_bin(outFp, cmpBuf, (size_t) cmpBytes);
}
inpBufIndex = (inpBufIndex + 1) % 2;
}
write_int(outFp, 0);
}
void test_decompress(FILE* outFp, FILE* inpFp)
{
LZ4_streamDecode_t lz4StreamDecode_body;
LZ4_streamDecode_t* lz4StreamDecode = &lz4StreamDecode_body;
char decBuf[2][BLOCK_BYTES];
int decBufIndex = 0;
LZ4_setStreamDecode(lz4StreamDecode, NULL, 0);
for(;;) {
char cmpBuf[LZ4_COMPRESSBOUND(BLOCK_BYTES)];
int cmpBytes = 0;
{
const size_t readCount0 = read_int(inpFp, &cmpBytes);
if(readCount0 != 1 || cmpBytes <= 0) {
break;
}
const size_t readCount1 = read_bin(inpFp, cmpBuf, (size_t) cmpBytes);
if(readCount1 != (size_t) cmpBytes) {
break;
}
}
{
char* const decPtr = decBuf[decBufIndex];
const int decBytes = LZ4_decompress_safe_continue(
lz4StreamDecode, cmpBuf, decPtr, cmpBytes, BLOCK_BYTES);
if(decBytes <= 0) {
break;
}
write_bin(outFp, decPtr, (size_t) decBytes);
}
decBufIndex = (decBufIndex + 1) % 2;
}
}
int compare(FILE* fp0, FILE* fp1)
{
int result = 0;
while(0 == result) {
char b0[65536];
char b1[65536];
const size_t r0 = read_bin(fp0, b0, sizeof(b0));
const size_t r1 = read_bin(fp1, b1, sizeof(b1));
result = (int) r0 - (int) r1;
if(0 == r0 || 0 == r1) {
break;
}
if(0 == result) {
result = memcmp(b0, b1, r0);
}
}
return result;
}
int main(int argc, 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.lz4s-%d", argv[1], BLOCK_BYTES);
snprintf(decFilename, 256, "%s.lz4s-%d.dec", argv[1], BLOCK_BYTES);
printf("inp = [%s]\n", inpFilename);
printf("lz4 = [%s]\n", lz4Filename);
printf("dec = [%s]\n", decFilename);
// compress
{
FILE* inpFp = fopen(inpFilename, "rb");
FILE* outFp = fopen(lz4Filename, "wb");
printf("compress : %s -> %s\n", inpFilename, lz4Filename);
test_compress(outFp, inpFp);
printf("compress : done\n");
fclose(outFp);
fclose(inpFp);
}
// decompress
{
FILE* inpFp = fopen(lz4Filename, "rb");
FILE* outFp = fopen(decFilename, "wb");
printf("decompress : %s -> %s\n", lz4Filename, decFilename);
test_decompress(outFp, inpFp);
printf("decompress : done\n");
fclose(outFp);
fclose(inpFp);
}
// verify
{
FILE* inpFp = fopen(inpFilename, "rb");
FILE* 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");
}
fclose(decFp);
fclose(inpFp);
}
return 0;
}