kmime_codecs.h

/*
    kmime_codecs.h
 
    This file is part of KMime, the KDE internet mail/usenet news message library.
    Copyright (c) 2001-2002 Marc Mutz <mutz@kde.org>
 
    KMime is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License, version 2, as
    published by the Free Software Foundation.
 
    KMime 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
    General Public License for more details.
 
    You should have received a copy of the GNU 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
 
    In addition, as a special exception, the copyright holders give
    permission to link the code of this library with any edition of
    the TQt library by Trolltech AS, Norway (or with modified versions
    of TQt that use the same license as TQt), and distribute linked
    combinations including the two.  You must obey the GNU General
    Public License in all respects for all of the code used other than
    TQt.  If you modify this file, you may extend this exception to
    your version of the file, but you are not obligated to do so.  If
    you do not wish to do so, delete this exception statement from
    your version.
*/
 
#ifndef __KMIME_CODECS__
#define __KMIME_CODECS__
 
#include <tqasciidict.h>
#if defined(TQT_THREAD_SUPPORT)
#  include <tqmutex.h>
#endif
 
#include <tqcstring.h> // TQByteArray
 
#include <kdebug.h> // for kdFatal()
#include <tdemacros.h>
 
namespace KMime {
 
// forward declarations:
class Encoder;
class Decoder;
 
class TDE_EXPORT Codec {
protected:
 
  static TQAsciiDict<Codec>* all;
#if defined(TQT_THREAD_SUPPORT)
  static TQMutex* dictLock;
#endif
 
  Codec() {}
private:
  static void fillDictionary();
 
public:
  static Codec * codecForName( const char * name );
  static Codec * codecForName( const TQCString & name );
 
  virtual int maxEncodedSizeFor( int insize, bool withCRLF=false ) const = 0;
  virtual int maxDecodedSizeFor( int insize, bool withCRLF=false ) const = 0;
 
  virtual Encoder * makeEncoder( bool withCRLF=false ) const = 0;
  virtual Decoder * makeDecoder( bool withCRLF=false ) const = 0;
 
  virtual bool encode( const char* & scursor, const char * const send,
               char* & dcursor, const char * const dend,
               bool withCRLF=false ) const;
 
  virtual bool decode( const char* & scursor, const char * const send,
               char* & dcursor, const char * const dend,
               bool withCRLF=false ) const;
 
  virtual TQByteArray encode( const TQByteArray & src, bool withCRLF=false ) const;
 
  virtual TQCString encodeToTQCString( const TQByteArray & src, bool withCRLF=false ) const;
 
  virtual TQByteArray decode( const TQByteArray & src, bool withCRLF=false ) const;
 
  virtual const char * name() const = 0;
 
  virtual ~Codec() {}
 
};
 
class Decoder {
protected:
  friend class Codec;
  Decoder( bool withCRLF=false )
    : mWithCRLF( withCRLF ) {}
public:
  virtual ~Decoder() {}
 
  virtual bool decode( const char* & scursor, const char * const send,
               char* & dcursor, const char * const dend ) = 0;
  virtual bool finish( char* & dcursor, const char * const dend ) = 0;
 
protected:
  const bool mWithCRLF;
};
 
class Encoder {
protected:
  friend class Codec;
  Encoder( bool withCRLF=false )
    : mOutputBufferCursor( 0 ), mWithCRLF( withCRLF ) {}
public:
  virtual ~Encoder() {}
 
  virtual bool encode( const char* & scursor, const char * const send,
               char* & dcursor, const char * const dend ) = 0;
 
  virtual bool finish( char* & dcursor, const char * const dend ) = 0;
 
protected:
  enum { maxBufferedChars = 8 };
 
  bool write( char ch, char* & dcursor, const char * const dend ) {
    if ( dcursor != dend ) {
      // if there's space in the output stream, write there:
      *dcursor++ = ch;
      return true;
    } else {
      // else buffer the output:
      kdFatal( mOutputBufferCursor >= maxBufferedChars )
    << "KMime::Encoder: internal buffer overflow!" << endl;
      mOutputBuffer[ mOutputBufferCursor++ ] = ch;
      return false;
    }
  }
 
  bool flushOutputBuffer( char* & dcursor, const char * const dend );
 
  bool writeCRLF( char* & dcursor, const char * const dend ) {
    if ( mWithCRLF )
      write( '\r', dcursor, dend );
    return write( '\n', dcursor, dend );
  }
 
private:
  char mOutputBuffer[ maxBufferedChars ];
protected:
  uchar mOutputBufferCursor;
  const bool mWithCRLF;
};
 
} // namespace KMime
 
#endif // __KMIME_CODECS__