sprint/io/xstream/xgzipfilter.h

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/******************************************************************************
*   sprint::xgzip
*
*   Copyright (C) 2005-2011  Paolo Medici <www.pmx.it>
*
*  This library is free software; you can redistribute it and/or
*  modify it under the terms of the GNU Lesser General Public
*  License as published by the Free Software Foundation; either
*  version 2.1 of the License, or (at your option) any later version.
*
*  This library is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
*  Lesser General Public License for more details.
*
*  You should have received a copy of the GNU Lesser General Public
*  License along with this library; if not, write to the Free Software
*  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*
*******************************************************************************/
#ifndef _XSTREAM_GZIP_FILTER_H
#define _XSTREAM_GZIP_FILTER_H

#include <sprint/io/xstream/xstream.h>
#include <zlib.h>

namespace sprint {
  namespace io {

class gzipf: public xstream {
        static const unsigned int BufferSize = 65536 - 256;
        
        xstream * m_stream;   
        int m_mode;           
        bool opened;          
        
        long out_size;     
    long in_size;       

        long cur_file_ptr;  
        unsigned int crc16; 
    unsigned long crc32; 
        char b[BufferSize]; 
        
        z_stream stream;  
        
        private:
        void skip(unsigned int len);
        int get(void);
        unsigned int get_word(void);
    void put_long(unsigned int);
        std::string get_string(void);
        bool read_header(void);
    void write_header(void);
        int decode_buffer(char *ptr, unsigned int len);
    int flush(void);
    bool do_flush(int f);
        public:
        gzipf(xstream * stream, flag_t open_mode, unsigned int compression_level);
        ~gzipf();
        bool is_good() const { return opened; }
        unsigned int capabilities() const;
        state_t state();        
        file_size_t length();
        file_size_t seek(file_size_t offset, seek_t type);
        int write(const char *data, unsigned int size);
        int read(char *data, unsigned int size);
                
};

} 
}

#endif