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

232 lines
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// LZ4 HC streaming API example : ring buffer
// Based on a previous example by Takayuki Matsuoka
/**************************************
* Compiler Options
**************************************/
#if defined(_MSC_VER) && (_MSC_VER <= 1800) /* Visual Studio <= 2013 */
# define _CRT_SECURE_NO_WARNINGS
# define snprintf sprintf_s
#endif
#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#ifdef __GNUC__
# pragma GCC diagnostic ignored "-Wmissing-braces" /* GCC bug 53119 : doesn't accept { 0 } as initializer (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119) */
#endif
/**************************************
* Includes
**************************************/
#include "lz4hc.h"
#include "lz4.h"
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
enum {
MESSAGE_MAX_BYTES = 1024,
RING_BUFFER_BYTES = 1024 * 8 + MESSAGE_MAX_BYTES,
DEC_BUFFER_BYTES = RING_BUFFER_BYTES + MESSAGE_MAX_BYTES // Intentionally larger to test unsynchronized ring buffers
};
size_t write_int32(FILE* fp, int32_t i) {
return fwrite(&i, sizeof(i), 1, fp);
}
size_t write_bin(FILE* fp, const void* array, int arrayBytes) {
assert(arrayBytes >= 0);
return fwrite(array, 1, (size_t)arrayBytes, fp);
}
size_t read_int32(FILE* fp, int32_t* i) {
return fread(i, sizeof(*i), 1, fp);
}
size_t read_bin(FILE* fp, void* array, int arrayBytes) {
assert(arrayBytes >= 0);
return fread(array, 1, (size_t)arrayBytes, fp);
}
void test_compress(FILE* outFp, FILE* inpFp)
{
LZ4_streamHC_t lz4Stream_body = { 0 };
LZ4_streamHC_t* lz4Stream = &lz4Stream_body;
static char inpBuf[RING_BUFFER_BYTES];
int inpOffset = 0;
for(;;) {
// Read random length ([1,MESSAGE_MAX_BYTES]) data to the ring buffer.
char* const inpPtr = &inpBuf[inpOffset];
const int randomLength = (rand() % MESSAGE_MAX_BYTES) + 1;
const int inpBytes = (int) read_bin(inpFp, inpPtr, randomLength);
if (0 == inpBytes) break;
#define CMPBUFSIZE (LZ4_COMPRESSBOUND(MESSAGE_MAX_BYTES))
{ char cmpBuf[CMPBUFSIZE];
const int cmpBytes = LZ4_compress_HC_continue(lz4Stream, inpPtr, cmpBuf, inpBytes, CMPBUFSIZE);
if(cmpBytes <= 0) break;
write_int32(outFp, cmpBytes);
write_bin(outFp, cmpBuf, cmpBytes);
inpOffset += inpBytes;
// Wraparound the ringbuffer offset
if(inpOffset >= RING_BUFFER_BYTES - MESSAGE_MAX_BYTES)
inpOffset = 0;
}
}
write_int32(outFp, 0);
}
void test_decompress(FILE* outFp, FILE* inpFp)
{
static char decBuf[DEC_BUFFER_BYTES];
int decOffset = 0;
LZ4_streamDecode_t lz4StreamDecode_body = { 0 };
LZ4_streamDecode_t* lz4StreamDecode = &lz4StreamDecode_body;
for(;;) {
int cmpBytes = 0;
char cmpBuf[CMPBUFSIZE];
{ const size_t r0 = read_int32(inpFp, &cmpBytes);
size_t r1;
if(r0 != 1 || cmpBytes <= 0)
break;
r1 = read_bin(inpFp, cmpBuf, cmpBytes);
if(r1 != (size_t) cmpBytes)
break;
}
{ char* const decPtr = &decBuf[decOffset];
const int decBytes = LZ4_decompress_safe_continue(
lz4StreamDecode, cmpBuf, decPtr, cmpBytes, MESSAGE_MAX_BYTES);
if(decBytes <= 0)
break;
decOffset += decBytes;
write_bin(outFp, decPtr, decBytes);
// Wraparound the ringbuffer offset
if(decOffset >= DEC_BUFFER_BYTES - MESSAGE_MAX_BYTES)
decOffset = 0;
}
}
}
// Compare 2 files content
// return 0 if identical
// return ByteNb>0 if different
size_t compare(FILE* f0, FILE* f1)
{
size_t result = 1;
for (;;) {
char b0[65536];
char b1[65536];
const size_t r0 = fread(b0, 1, sizeof(b0), f0);
const size_t r1 = fread(b1, 1, sizeof(b1), f1);
if ((r0==0) && (r1==0)) return 0; // success
if (r0 != r1) {
size_t smallest = r0;
if (r1<r0) smallest = r1;
result += smallest;
break;
}
if (memcmp(b0, b1, r0)) {
unsigned errorPos = 0;
while ((errorPos < r0) && (b0[errorPos]==b1[errorPos])) errorPos++;
result += errorPos;
break;
}
result += sizeof(b0);
}
return result;
}
int main(int argc, const char** argv)
{
char inpFilename[256] = { 0 };
char lz4Filename[256] = { 0 };
char decFilename[256] = { 0 };
unsigned fileID = 1;
unsigned pause = 0;
if(argc < 2) {
printf("Please specify input filename\n");
return 0;
}
if (!strcmp(argv[1], "-p")) { pause = 1; fileID = 2; }
snprintf(inpFilename, 256, "%s", argv[fileID]);
snprintf(lz4Filename, 256, "%s.lz4s-%d", argv[fileID], 9);
snprintf(decFilename, 256, "%s.lz4s-%d.dec", argv[fileID], 9);
printf("input = [%s]\n", inpFilename);
printf("lz4 = [%s]\n", lz4Filename);
printf("decoded = [%s]\n", decFilename);
// compress
{ FILE* const inpFp = fopen(inpFilename, "rb");
FILE* const outFp = fopen(lz4Filename, "wb");
test_compress(outFp, inpFp);
fclose(outFp);
fclose(inpFp);
}
// decompress
{ FILE* const inpFp = fopen(lz4Filename, "rb");
FILE* const outFp = fopen(decFilename, "wb");
test_decompress(outFp, inpFp);
fclose(outFp);
fclose(inpFp);
}
// verify
{ FILE* const inpFp = fopen(inpFilename, "rb");
FILE* const decFp = fopen(decFilename, "rb");
const size_t cmp = compare(inpFp, decFp);
if(0 == cmp) {
printf("Verify : OK\n");
} else {
printf("Verify : NG : error at pos %u\n", (unsigned)cmp-1);
}
fclose(decFp);
fclose(inpFp);
}
if (pause) {
int unused;
printf("Press enter to continue ...\n");
unused = getchar(); (void)unused; /* silence static analyzer */
}
return 0;
}