zlib deflate and inflate class for c++-白红宇

zlib deflate and inflate class for c++

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发布时间：2019-06-30

本文共 4604 字，大约阅读时间需要 15 分钟。

Compression.h

/* * Compression.h * *  Created on: Aug 26, 2013 *      Author: jerome */#ifndef COMPRESSION_H_#define COMPRESSION_H_#include 
    
     #include 
     
      #include 
      
       #include 
       
        #define COMPRESSION_LEVEL Z_DEFAULT_COMPRESSION#define BUFFER_SIZE 16384typedef std::vector
        
          StlVecUnChar;class Compression{public:    enum CompressLevel    {        NO_COMPRESSION      = Z_NO_COMPRESSION,        BEST_SPEED          = Z_BEST_SPEED,        BEST_COMPRESSION    = Z_BEST_COMPRESSION,        DEFAULT_COMPRESSION = Z_DEFAULT_COMPRESSION    };	Compression()        : m_zstream(), m_IsCompress(true), m_bufferInCapa(BUFFER_SIZE), m_bufferOutCapa(BUFFER_SIZE), m_compressLevel(DEFAULT_COMPRESSION)	{	}    Compression(bool isCom, CompressLevel level = DEFAULT_COMPRESSION)        : m_zstream(), m_IsCompress(isCom), m_bufferInCapa(BUFFER_SIZE), m_bufferOutCapa(BUFFER_SIZE), m_compressLevel(level)	{	}	virtual ~Compression();	int Init();    int Deflate(const StlVecUnChar &inStr, StlVecUnChar &outStr);    int Inflate(const StlVecUnChar &inStr, StlVecUnChar &outStr);private:    z_stream      m_zstream;               // Stream structure used by zlib    bool          m_IsCompress;            // True: compress. False: decompress    unsigned char m_bufferIn[BUFFER_SIZE]; // Input buffer for zlib    unsigned char m_bufferOut[BUFFER_SIZE];// Output Buffer for zlib    const int     m_bufferInCapa;          // Input buffer capacity    const int     m_bufferOutCapa;         // Output buffer capacity    CompressLevel m_compressLevel;         // Compress level};#endif /* COMPRESSION_H_ */

Compression.cpp

/* * Compression.cpp * *  Created on: Aug 26, 2013 *      Author: jerome */#include "Compression.h"#include 
    
     #include 
     
      #include 
      
       Compression::~Compression() {	// TODO Auto-generated destructor stub}int Compression::Init(){    int ret;	m_zstream.zalloc = NULL;	m_zstream.zfree  = NULL;	m_zstream.opaque = NULL;	if(m_IsCompress)	{		ret = deflateInit2_(&m_zstream, m_compressLevel, Z_DEFLATED, MAX_WBITS,				MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY, ZLIB_VERSION, sizeof(z_stream));	}	else	{		ret = inflateInit2_(&m_zstream, MAX_WBITS, ZLIB_VERSION, sizeof(z_stream));	}	return ret;}int Compression::Deflate(const StlVecUnChar &inStr, StlVecUnChar &outStr){    int ret;    int flush;    size_t lastByte = inStr.size ();	int have  = 0;    while (lastByte > 0)	{        if (lastByte > m_bufferInCapa)		{            memcpy (m_bufferIn, &inStr[inStr.size () - lastByte], m_bufferInCapa);            lastByte           -= m_bufferInCapa;            m_zstream.avail_in  = m_bufferInCapa;            flush               = Z_NO_FLUSH;		}		else		{            memcpy (m_bufferIn, &inStr[inStr.size () - lastByte], lastByte);            m_zstream.avail_in = lastByte;            lastByte           = 0;            flush              = Z_FINISH;		}        m_zstream.next_in  = m_bufferIn;		do		{            m_zstream.avail_out = m_bufferOutCapa;            m_zstream.next_out  = m_bufferOut;			ret = deflate(&m_zstream, flush);			assert(ret != Z_STREAM_ERROR);            have = m_bufferOutCapa - m_zstream.avail_out;            outStr.insert (outStr.end (), m_bufferOut, m_bufferOut + have);		}while(m_zstream.avail_out == 0);		assert(m_zstream.avail_in == 0);	}	// Finish deflate	(void)deflateEnd(&m_zstream);	return Z_OK;}int Compression::Inflate(const StlVecUnChar &inStr, StlVecUnChar &outStr){    int ret;	int lastByte = inStr.size();	int have  = 0;	while (lastByte > 0)	{        if (lastByte > m_bufferInCapa)		{            memcpy(m_bufferIn, &inStr[inStr.size () - lastByte], m_bufferInCapa);            lastByte          -= m_bufferInCapa;            m_zstream.avail_in = m_bufferInCapa;		}		else		{            memcpy(m_bufferIn, &inStr[inStr.size () - lastByte], lastByte);			m_zstream.avail_in = lastByte;			lastByte = 0;		}        m_zstream.next_in  = m_bufferIn;		do		{            m_zstream.next_out  = m_bufferOut;            m_zstream.avail_out = m_bufferOutCapa;			ret = inflate(&m_zstream, Z_NO_FLUSH);			assert(ret != Z_STREAM_ERROR);			switch(ret)			{			case Z_NEED_DICT:				ret = Z_DATA_ERROR;			case Z_DATA_ERROR:			case Z_MEM_ERROR:				(void)inflateEnd(&m_zstream);				return ret;			}            have  = m_bufferOutCapa - m_zstream.avail_out;            outStr.insert (outStr.end (), m_bufferOut, m_bufferOut + have);		}while(m_zstream.avail_out == 0);	}	(void)inflateEnd(&m_zstream);	return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;}