zlib使用与性能测试

　　3.性能测试
　　针对1M数据分别调用compress压缩和uncompress解压缩，循环10次。
　　代码如下：
#include <stdio.h>
#include <time.h>
#include "zlib.h"
const int MAX_BUFFER_SIZE = 1024*1024*4;
unsigned char DATA_BUFFER[MAX_BUFFER_SIZE];
void testCompress()
{
const char * file = "/tmp/e2.txt.backup";
FILE *f1 = fopen(file，"r");
if(f1)
{
fseek(f1，0，2);
int len = ftell(f1);
fseek(f1，0，0);
char * data = new char[len];
fread(data，1，len，f1);
fclose(f1);
//uLong dst_len = MAX_BUFFER_SIZE;
//Bytef * dst = (Bytef*)DATA_BUFFER;
clock_t start = clock();
for(int i=0; i<10; i++)
{
uLong dst_len = MAX_BUFFER_SIZE;
Bytef * dst = (Bytef*)DATA_BUFFER;
compress(dst，&dst_len，(Bytef *)data，(uLong)len);
}
clock_t end = clock();
printf("time used(ms):%.2f "，1000.0*(end-start)/CLOCKS_PER_SEC);
delete [] data;
}
}
void testunCompress()
{
const char * file = "/tmp/2.gz";
FILE *f1 = fopen(file，"r");
if(f1)
{
fseek(f1，0，2);
int len = ftell(f1);
fseek(f1，0，0);
char * data = new char[len];
fread(data，1，len，f1);
fclose(f1);
//uLong dst_len = MAX_BUFFER_SIZE;
//Bytef * dst = (Bytef*)DATA_BUFFER;
clock_t start = clock();
for(int i=0; i<10; i++)
{
uLong dst_len = MAX_BUFFER_SIZE;
Bytef * dst = (Bytef*)DATA_BUFFER;
uncompress(dst，&dst_len，(Bytef *)data，(uLong)len);
}
clock_t end = clock();
printf("time used(ms):%.2f "，1000.0*(end-start)/CLOCKS_PER_SEC);
delete [] data;
}
}
int main(int argc， char **argv)
{
testCompress();
testunCompress();
return 0;
}
　　测试结果：
time used(ms):470.00
time used(ms):40.00
　　4.总结
　　zlib压缩1M数据耗时47ms左右，解压缩4ms左右。解压非常快。