zstd压缩与lz4压缩比较（C语言）
最近由于业务需求需要对数据进行压缩，相关压缩算法介绍的都比较多，比较详细，笔者在这里就不赘述。本篇主要针对C语言调用zstd、lz4压缩算法的接口调用,并对其做简单的比较。
ZSTD源码编译及测试
源码编译
1、获取zstd源码，网址：https://github.com/facebook/zstd/，打开网址如下操作：
点击红色获取Releases版本源码，拉到页面最下边如下图：
2、将源码移到自己的环境解压（tar -zxcf zstd-1.5.2.tar.gz）、编译(make)，生成zstd静态库、动态库及程序调用所需头文件。如下图所示：
案例调用
1、创建一个与刚解压的zstd-1.5.2目录同级的目录zstd_demo；将案例代码与Makefile文件放入目录中，如下图所示：
2、test.c与Makefile文件如下：
/******************************************** Date : 2022-05-17 Author : lijd Func : 用生产业务数据测试zstd压缩算法 ********************************************/ #include#include #include "zstd.h" #include char g_str[] ="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"; // 十六进制转字符串 int HexToStr(char *p_hexstr, int iHexLen, char *pdststr) { int iret = 0; while(p_hexstr != NULL && pdststr != NULL && iHexLen > 1) { char cTemp = '0'; // printf("1:%c, 2:%c\n", p_hexstr[0], p_hexstr[1]); // 小写统一转大写 if(p_hexstr[0] >= '0' && p_hexstr[0] <= '9') { cTemp = p_hexstr[0] - '0'; } else if(p_hexstr[0] >= 'A' && p_hexstr[0] <= 'F') { cTemp = p_hexstr[0] - 'A' + 10; } else if(p_hexstr[0] >= 'a' && p_hexstr[0] <= 'f') { cTemp = p_hexstr[0] - 'a' + 10; } else { printf("the hex str is error!\n"); break; } *pdststr = cTemp * 16; if(p_hexstr[1] >= '0' && p_hexstr[1] <= '9') { cTemp = p_hexstr[1] - '0'; } else if(p_hexstr[1] >= 'A' && p_hexstr[1] <= 'F') { cTemp = p_hexstr[1] - 'A' + 10; } else if(p_hexstr[1] >= 'a' && p_hexstr[1] <= 'f') { cTemp = p_hexstr[1] - 'a' + 10; } else { printf("the hex str is error!\n"); break; } *pdststr += cTemp; // printf("---iHexLen:%d, pdststr:%c\n", iHexLen, *pdststr); iHexLen -= 2; p_hexstr += 2; pdststr++; iret++; } // printf("iret : %d\n", iret); return iret; } int main() { struct timeval curTime; char src[2048] = {0}; char dst[2048] = {0}, src2[2048] = {0}; int iStrlen = HexToStr(g_str, strlen(g_str), src); printf("业务数据原始长度 : %d 字节\n", iStrlen); gettimeofday(&curTime, NULL); int time_usec = curTime.tv_usec; int cSize = ZSTD_compress(dst, 2048, src, iStrlen, 3); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec - time_usec; printf("ZSTD 压缩所用时间 : %u 毫秒, 压缩后长度 : %d 字节\n", time_usec, cSize); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec; int cSize2 = ZSTD_decompress(src2, 2048, dst, cSize); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec - time_usec; printf("压缩后数据解压所需时间 : %u 毫秒, 解压后数据长度 : %d 字节\n", time_usec, cSize2); return 0; } # Func: zstd_demo # Auth: lijd # Date: 2022/05/17 CC := gcc TARGET := zstd_demo INCLUDES := ../zstd-1.5.2/lib/ LIBDIRS := ../zstd-1.5.2/lib/ LIBS := zstd FLAGES := $(addprefix -I, $(INCLUDES)) $(addprefix -L, $(LIBDIRS)) $(addprefix -l, $(LIBS)) SRCS := $(wildcard *.c) $(TARGET): $(SRCS) $(CC) -g -Wall -o $@ $^ $(FLAGES) @echo "==================================== Build OK!!! ====================================" .PHONY: clean clean: @rm -rf $(TARGET)3、编译成功后，运行可能找不到依赖的动态库，需要将环境变量设置一下，注意笔者用的这种设置方式只是暂时的。如下图：
lz4源码编译及测试
源码编译
1、获取zstd源码，网址：Index of /ubuntu/pool/main/l/lz4，打开网址如下操作：
2、将源码移到自己的环境解压（tar -zxcf lz4_1.9.2.orig.tar.gz）、编译(make)，生成lz4静态库、动态库及程序调用所需头文件。如下图所示：
案例调用
1、创建一个与刚解压的lz4_1.9.2目录同级的目录lz4_demo；将test.c与Makefile文件放入目录中，代码只有调用压缩解压的函数接口有变动，其余都一样，Makefile只有小的改动。这里只给出变动的main函数如下：
int main() { struct timeval curTime; char src[2048] = {0}; char dst[2048] = {0}, src2[2048] = {0}; int iStrlen = HexToStr(g_str, strlen(g_str), src); printf("业务数据原始长度 : %d 字节\n", iStrlen); gettimeofday(&curTime, NULL); int time_usec = curTime.tv_usec; int cSize = LZ4_compress_default(src, dst, iStrlen, 2048); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec - time_usec; printf("LZ4 压缩所用时间 : %u 毫秒, 压缩后长度 : %d 字节\n", time_usec, cSize); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec; int cSize2 = LZ4_decompress_safe(dst, src2, cSize, 2048); gettimeofday(&curTime, NULL); time_usec = curTime.tv_usec - time_usec; printf("压缩后数据解压所需时间 : %u 毫秒, 解压后数据长度 : %d 字节\n", time_usec, cSize2); return 0; }2、编译成功后运行如下图：
总结
笔者将相同的业务数据，用不同的压缩解压算法进行压缩、解压；得到的结构也显而易见：zstd(81%)在压缩率优于lz4(71%)；但在压缩、解压时间上lz4远远优于zstd，lz4不愧为压缩界的速度之王。