indchan.h

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/*
 * indchan.h
 *
 * Indirect I/O channel class.
 *
 * Portable Windows Library
 *
 * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 */

#ifndef PTLIB_INDIRECTCHANNEL_H
#define PTLIB_INDIRECTCHANNEL_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif

#include <ptlib/channel.h>
#include <ptlib/syncthrd.h>

class PIndirectChannel : public PChannel
{
  PCLASSINFO(PIndirectChannel, PChannel);

  public:
    PIndirectChannel();

    ~PIndirectChannel();


    Comparison Compare(
      const PObject & obj   
    ) const;


    virtual PString GetName() const;

    virtual P_INT_PTR GetHandle() const;

    virtual PBoolean Close();

    virtual PBoolean IsOpen() const;

    virtual PBoolean Read(
      void * buf,   
      PINDEX len    
    );

    virtual int ReadChar();

    virtual PBoolean Write(
      const void * buf, 
      PINDEX len        
    );

    virtual PBoolean Shutdown(
      ShutdownValue option   
    );

    virtual bool SetLocalEcho(
      bool localEcho
    );


    virtual PChannel * GetBaseReadChannel() const;

    virtual PChannel * GetBaseWriteChannel() const;

    virtual bool CloseBaseReadChannel();

    virtual bool CloseBaseWriteChannel();

    virtual PString GetErrorText(
      ErrorGroup group = NumErrorGroups   
    ) const;

    PBoolean Open(
      PChannel & channel   
    );

    PBoolean Open(
      PChannel * channel,      
      PBoolean autoDelete = true   
    );

    PBoolean Open(
      PChannel * readChannel,      
      PChannel * writeChannel,     
      PBoolean autoDeleteRead = true,  
      PBoolean autoDeleteWrite = true  
    );

    PChannel * Detach(
      ShutdownValue option = ShutdownReadAndWrite   
    );

    PChannel * GetReadChannel() const;

    bool SetReadChannel(
      PChannel * channel,         
      bool autoDelete = true,     
      bool closeExisting = false  
    );

    PChannel * GetWriteChannel() const;

    PBoolean SetWriteChannel(
      PChannel * channel,         
      bool autoDelete = true,     
      bool closeExisting = false  
    );

    template <class ChannelClass> ChannelClass * FindChannel()
    {
      ChannelClass * channel = dynamic_cast<ChannelClass *>(this);
      if (channel == NULL) {
        PIndirectChannel * indirect = dynamic_cast<PIndirectChannel *>(readChannel);
        if (indirect == NULL || (channel = indirect->FindChannel<ChannelClass>()) == NULL) {
          indirect = dynamic_cast<PIndirectChannel *>(writeChannel);
          if (indirect != NULL)
            channel = indirect->FindChannel<ChannelClass>();
        }
      }
      return channel;
    }


  protected:
    virtual PBoolean OnOpen();


  // Member variables
    PChannel * readChannel;

    PBoolean readAutoDelete;

    PChannel * writeChannel;

    PBoolean writeAutoDelete;

    PDECLARE_READ_WRITE_MUTEX(channelPointerMutex);
};


#endif // PTLIB_INDIRECTCHANNEL_H


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