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 pos
		in_str += strm.avail_in;
		flush = (in_str == end) ? Z_FINISH : Z_NO_FLUSH;

		/* run deflate() on input until output buffer not full, finish
		compression 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 pos
		in_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;
}