使用zlib对字符串进行压缩

最新推荐文章于 2024-01-04 21:09:41 发布

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最新推荐文章于 2024-01-04 21:09:41 发布

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分类专栏： c++ 文章标签： zlib

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编译好的zlib库：
https://download.youkuaiyun.com/download/yuxing55555/11938358

参考源码中的示例：zlib-1.2.11/test/example.c

压缩，解压缩及其测试：

在.pro中添加：

ZLIB_DIR = F:/zlib/qt5.3/lib-debug
INCLUDEPATH += $${ZLIB_DIR}/include
LIBS += -L$${ZLIB_DIR}/lib \
        libzlib

#include "zlib.h"
#include <stdio.h>
#include <iostream>

#ifdef STDC
#  include <string.h>
#  include <stdlib.h>
#endif

#define CHECK_ERR(err, msg) { \
    if (err != Z_OK) { \
        fprintf(stderr, "%s error: %d\n", msg, err); \
        exit(1); \
    } \
}
//压缩
char* Compress(char* src,int srcLen, int* comprLen){
    int compressrate = 2;
    int err;
    int len = strlen(src) + 1;
    std::cout << "len:"<<len<<",srcLen:"<<srcLen<<std::endl;
    if(len != srcLen){
        std::cout << "strlen != srcLen" << std::endl;
    }
    *comprLen = len*compressrate*sizeof(int);
    std::cout << "ori comprLen:" << *comprLen << std::endl;
    Byte *compr = (Byte*)calloc((uInt)(*comprLen), 1);
    if (compr == Z_NULL) {
        printf("out of memory\n");
        return NULL;
    }
    err = compress(compr,(uLong*)comprLen,(const Bytef*)src,(uLong)len);
    CHECK_ERR(err, "compress");
    return (char*)compr;
}
//解压缩
char* Uncompress(char* compr, int comprLen,int& uncomprLen){
    int compressrate = 2;
    uncomprLen = comprLen * compressrate * sizeof(int);
    std::cout << "ori uncomprLen:" << uncomprLen << std::endl;
    Byte *uncompr = (Byte*)calloc((uInt)(uncomprLen), 1);
    if (uncompr == Z_NULL) {
        printf("out of memory\n");
        return NULL;
    }
    int err;
    err = uncompress(uncompr, (uLong*)(&uncomprLen),
                     (Byte*)compr, (uLong)comprLen);
    CHECK_ERR(err, "uncompress");
    return (char*)uncompr;
}

int main(int argc, char *argv[])
{
    //测试
    char* test = "hello,world";
    int srcLen = strlen(test)+1;
    int comprLen = 0;
    char* compress = Compress(test,srcLen,&comprLen);
    printf("compress(): %s %d\n", compress,comprLen);
    int uncomprLen = 0;
    char* uncompress = Uncompress(compress,comprLen,uncomprLen);
    printf("uncompress(): %s %d\n", uncompress,uncomprLen);
    if(compress != NULL){
        free(compress);
    }
    if(uncompress != NULL){
        free(uncompress);
    }
    return 0;
}