gzfstream.h

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// -*-c++-*-
 
/*
 *Copyright:
 
 Copyright (C) Hidehisa Akiyama
 
 This code 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 3 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 *EndCopyright:
 */
 
 
#ifndef RCSC_GZ_GZFSTREAM_H
#define RCSC_GZ_GZFSTREAM_H
 
#include <memory>
#include <iostream>
#include <string>
 
namespace rcsc {
 
class gzfilebuf
    : public std::streambuf {
public:
    enum CompressionLevel {
        DEFAULT_COMPRESSION = -1,
        NO_COMPRESSION = 0,
        BEST_SPEED = 1,
        BEST_COMPRESSION = 9,
    };
 
    enum Strategy {
        DEFAULT_STRATEGY = 0,
        FILTERED = 1,
        HUFFMAN_ONLY = 2,
        RLE = 3,
    };
 
private:
 
    struct Impl;
 
    std::unique_ptr< Impl > M_impl;
 
    std::size_t M_buf_size;
    char_type * M_buf;
 
    int M_remained_size;
    char_type M_remained_char;
 
 
    gzfilebuf( const gzfilebuf & ) = delete;
    gzfilebuf & operator=( const gzfilebuf & ) = delete;
 
public:
    gzfilebuf();
 
    virtual
    ~gzfilebuf();
 
    bool is_open();
 
    gzfilebuf * open( const char * path,
                      std::ios_base::openmode mode,
                      int level = DEFAULT_COMPRESSION,
                      int strategy = DEFAULT_STRATEGY );
 
    gzfilebuf * close() throw();
 
 
private:
 
    bool flushBuf();
 
    std::string makeModeString( std::ios_base::openmode mode,
                                int level,
                                int strategy );
 
    void destroyInternalBuffer() throw();
 
protected:
    //virtual
    //void imbue( const locale& loc );
    //virtual
    //int_type pbackfail( int_type c );
    //virtual
    //std::streambuf* setbuf( char_type* p, std::streamsize n );
 
    virtual
    std::streampos seekoff( std::streamoff off,
                            std::ios_base::seekdir way,
                            std::ios_base::openmode mode );
 
    virtual
    std::streampos seekpos( std::streampos pos,
                            std::ios_base::openmode mode );
 
    virtual
    std::streamsize showmanyc();
 
    virtual
    int sync();
 
    virtual
    std::streambuf::int_type overflow( std::streambuf::int_type c );
 
    // Not need to override because super class works sufficiently.
    //virtual
    //int_type uflow();
 
    virtual
    std::streambuf::int_type underflow();
 
    // Not need to override because super class works sufficiently.
    //virtual
    //std::streamsize xsgetn( char_type* s, std::streamsize n );
 
    // Not need to override because super class works sufficiently.
    //virtual
    //std::streamsize xsputn( char_type * s, std::streamsize n );
 
    /*   All virtual methods defined in std::streambuf.
         See: http://www.cplusplus.com/ref/iostream/
      XXX imbue Imbue locale [virtual]
      OK overflow Put character at current position [virtual]
      XXX pbackfail Put character back [virtual]
      N/A seekoff Set relative position of internal position pointer [virtual]
      OK seekpos  Set absolute position of internal position pointer [virtual]
      XXX setbuf  Set buffer [virtual]
      OK showmanyc  Get number of characters availbale in input sequence [virtual]
      OK sync Synchronize stream buffer [virtual]
      OK uflow  Get current character [virtual]
      OK underflow  Get current character [virtual]
      OK xsgetn Get some characters [virtual]
      OK xsputn Write some characters [virtual]
    */
};
 
 
/*-------------------------------------------------------------------*/
/*-------------------------------------------------------------------*/
/*-------------------------------------------------------------------*/
 
 
class gzifstream
    : public std::istream {
private:
    gzfilebuf M_file_buf;
public:
    gzifstream();
 
    explicit
    gzifstream( const char * path );
 
    gzfilebuf * rdbuf() const
      {
          return const_cast< gzfilebuf * >( &M_file_buf );
      }
 
    bool is_open()
      {
          return M_file_buf.is_open();
      }
 
    void open( const char * path );
 
    void close();
};
 
/*****************************************************************************/
 
class gzofstream
    : public std::ostream {
private:
    gzfilebuf M_file_buf;
 
public:
    gzofstream();
 
    explicit
    gzofstream( const char* path,
                int level = gzfilebuf::DEFAULT_COMPRESSION,
                int strategy = gzfilebuf::DEFAULT_STRATEGY );
 
    gzfilebuf * rdbuf() const
      {
          return const_cast< gzfilebuf * >( &M_file_buf );
      }
 
    bool is_open()
      {
          return M_file_buf.is_open();
      }
 
    void  open( const char * path,
                int level = gzfilebuf::DEFAULT_COMPRESSION,
                int strategy = gzfilebuf::DEFAULT_STRATEGY );
 
    void close();
};
 
} // end namespace
 
#endif // include guard