官网下载zlib库编译后就能使用

#include <string>
#include <iostream>
#include <memory>
#include <assert.h>
#include <cstring>
#include "zlib.h"#define CHUNK 16384/* Compress from file source to file dest until EOF on source.
def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
allocated for processing, Z_STREAM_ERROR if an invalid compression
level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
version of the library linked do not match, or Z_ERRNO if there is
an error reading or writing the files. */
int CompressString(const char* in_str, size_t in_len,std::string& out_str, int level)
{if (!in_str)return Z_DATA_ERROR;int ret, flush;unsigned have;z_stream strm;unsigned char out[CHUNK];/* allocate deflate state */strm.zalloc = Z_NULL;strm.zfree = Z_NULL;strm.opaque = Z_NULL;ret = deflateInit(&strm, level);if (ret != Z_OK)return ret;std::shared_ptr<z_stream> sp_strm(&strm, [](z_stream* strm) {(void)deflateEnd(strm);});const char* end = in_str + in_len;size_t pos_index = 0;size_t distance = 0;/* compress until end of file */do {distance = end - in_str;strm.avail_in = (distance >= CHUNK) ? CHUNK : distance;strm.next_in = (Bytef*)in_str;// next posin_str += strm.avail_in;flush = (in_str == end) ? Z_FINISH : Z_NO_FLUSH;/* run deflate() on input until output buffer not full, finishcompression if all of source has been read in */do {strm.avail_out = CHUNK;strm.next_out = out;ret = deflate(&strm, flush);  /* no bad return value */if (ret == Z_STREAM_ERROR)break;have = CHUNK - strm.avail_out;out_str.append((const char*)out, have);} while (strm.avail_out == 0);if (strm.avail_in != 0);   /* all input will be used */break;/* done when last data in file processed */} while (flush != Z_FINISH);if (ret != Z_STREAM_END) /* stream will be complete */return Z_STREAM_ERROR;/* clean up and return */return Z_OK;
}/* Decompress from file source to file dest until stream ends or EOF.
inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
allocated for processing, Z_DATA_ERROR if the deflate data is
invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
the version of the library linked do not match, or Z_ERRNO if there
is an error reading or writing the files. */
int DecompressString(const char* in_str, size_t in_len, std::string& out_str)
{if (!in_str)return Z_DATA_ERROR;int ret;unsigned have;z_stream strm;unsigned char out[CHUNK];/* allocate inflate state */strm.zalloc = Z_NULL;strm.zfree = Z_NULL;strm.opaque = Z_NULL;strm.avail_in = 0;strm.next_in = Z_NULL;ret = inflateInit(&strm);if (ret != Z_OK)return ret;std::shared_ptr<z_stream> sp_strm(&strm, [](z_stream* strm) {(void)inflateEnd(strm);});const char* end = in_str + in_len;size_t pos_index = 0;size_t distance = 0;int flush = 0;/* decompress until deflate stream ends or end of file */do {distance = end - in_str;strm.avail_in = (distance >= CHUNK) ? CHUNK : distance;strm.next_in = (Bytef*)in_str;// next posin_str += strm.avail_in;flush = (in_str == end) ? Z_FINISH : Z_NO_FLUSH;/* run inflate() on input until output buffer not full */do {strm.avail_out = CHUNK;strm.next_out = out;ret = inflate(&strm, Z_NO_FLUSH);if (ret == Z_STREAM_ERROR) /* state not clobbered */break;switch (ret) {case Z_NEED_DICT:ret = Z_DATA_ERROR;   /* and fall through */case Z_DATA_ERROR:case Z_MEM_ERROR:return ret;}have = CHUNK - strm.avail_out;out_str.append((const char*)out, have);} while (strm.avail_out == 0);/* done when inflate() says it's done */} while (flush != Z_FINISH);/* clean up and return */return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}int main()
{const char* buf = "123123123qazqazqazwsxxswwsxwsx111111111111111111111111111111111111111\n";std::cout << "========= CompressString ===========" << std::endl;std::cout << "Source Buffer Size: " << strlen(buf) << std::endl;std::string out_compress;assert(CompressString(buf, strlen(buf), out_compress, Z_DEFAULT_COMPRESSION) == Z_OK);std::cout <<"compress data: data[" << out_compress.size() << "]:" << out_compress << std::endl;std::cout << "========= DecompressString ===========" << std::endl;std::string out_decompress;assert(DecompressString(out_compress.c_str(), out_compress.size(), out_decompress) == Z_OK);std::cout << "decompress data["<< out_decompress .size()<<"]:"<<out_decompress<<std::endl;assert(!out_decompress.compare(buf));system("pause");return 0;
}