#line 1 "/user/cvsspst/ees1cg/RAVL/RAVL-0.7/OS/Network/NetIPort.hh"
// This file is part of RAVL, Recognition And Vision Library 
// Copyright (C) 2001, University of Surrey
// This code may be redistributed under the terms of the GNU Lesser
// General Public License (LGPL). See the lgpl.licence file for details or
// see http://www.gnu.org/copyleft/lesser.html
// file-header-ends-here
#ifndef RAVL_NETIPORT_HEADER
#define RAVL_NETIPORT_HEADER 1
////////////////////////////////////////////////////////////////////
//! rcsid="$Id: NetIPort.hh,v 1.3 2002/08/08 16:03:20 craftit Exp $"
//! author="Charles Galambos"
//! lib=RavlNet
//! docentry="Ravl.OS.Network.NetPort"
//! file="Ravl/OS/Network/NetIPort.hh"

#include "Ravl/DP/SPort.hh"
#include "Ravl/OS/NetEndPoint.hh"
#include "Ravl/Threads/RWLock.hh"
#include "Ravl/Threads/Semaphore.hh"

namespace RavlN {

  //! userlevel=Develop
  //: Base class for NetIPorts.
  
  class NetISPortBaseC 
  {
  public:
    NetISPortBaseC(const StringC &server,const StringC &portName,const type_info &ndataType);
    //: Default constructor.
    
  protected:
    bool Init();
    //: Initalise link.
    
    bool RecvState(UIntT &at,UIntT &start,UIntT &end);
    //: Handle incoming state info.
    
    bool ReqFailed(IntT &flag);
    //: Handle request failed.
    
    NetEndPointC ep;
    
    StringC portName,dataType;
    
    UIntT start,size;    
    UIntT at; // Position in stream.
    bool gotEOS; // Got an End Of Stream.
    RWLockC rwlock;
    SemaphoreC recieved; // Posted when new data arrives.
    UIntT flag;
  };
  
  //! userlevel=Develop
  //: Input port body
  
  template<class DataT>
  class NetISPortBodyC
    : public DPISPortBodyC<DataT>,
      public NetISPortBaseC
  {
  public:
    NetISPortBodyC(const StringC &server,const StringC &portName)
      : NetISPortBaseC(server,portName,typeid(DataT))
    { Init(); }
    //: Constructor.
    
    virtual bool Seek(UIntT off) { 
      at = off; 
      return true;
    }
    //: Seek to location in stream.
    // Returns false, if seek failed. (Maybe because its
    // not implemented.)
    // if an error occurered (Seek returned False) then stream
    // position will not be changed.
    
    virtual bool DSeek(IntT off) {
      if(off < 0) {
	if((UIntT) (-off) > at)
	  return false; // Seek to before beginning on file.
      }
      // Should check size & start ?
      at += off;
      return true;
    }
    //: Delta Seek, goto location relative to the current one.
    // The default behavour of this functions is :
    // Do some error checking then:
    //   Seek((UIntT)((IntT) Tell() + off));
    // if an error occurered (DSeek returned False) then stream
    // position will not be changed.
    
    virtual UIntT Tell() const 
    { return at; }
    //: Find current location in stream.
    // Defined as the index of the next object to be written or read.
    // May return ((UIntT) (-1)) if not implemented.
    
    virtual UIntT Size() const
    { return size; }
    //: Find the total size of the stream. (assuming it starts from 0)
    // May return ((UIntT) (-1)) if not implemented.
    
    virtual UIntT Start() const
    { return start; }
    //: Find the offset where the stream begins, normally zero.
    // Defaults to 0
    
    virtual bool IsGetReady() const
    { return !gotEOS && ep.IsValid(); } 
    //: Is some data ready ?
    // true = yes.
    
    virtual bool IsGetEOS() const
    { return gotEOS; }
    //: Has the End Of Stream been reached ?
    // true = yes.
    
    virtual DataT Get();
    //: Get next piece of data.
    
    virtual bool Get(DataT &buf);
    //: Get next piece of data.
    
  protected:
    bool Init();
    //: Initalise link.
    
    bool RecvData(UIntT &pos,DataT &dat);
    //: Recieve data.
    
    DataT data; 
  };

  //! userlevel=Normal
  //: Input port.
  
  template<class DataT>
  class NetISPortC
    : public DPISPortC<DataT>
  {
  public:
    NetISPortC()
    {}
    //: Default constructor.
    // creates an invalid handle.
    
    NetISPortC(const StringC &server,const StringC &portName)
      : DPEntityC(*new NetISPortBodyC<DataT>(server,portName))
    {}
    //: Constructor.
  };


  /////////////////////////////////////////////////////////////////////////////////////

  template<class DataT>
  bool NetISPortBodyC<DataT>::Init() {
    ep.RegisterR(5,"SendData",*this,&NetISPortBodyC<DataT>::RecvData);
    return NetISPortBaseC::Init();
  }
  
  template<class DataT>
  bool NetISPortBodyC<DataT>::RecvData(UIntT &pos,DataT &dat) {
    //cerr << "NetISPortBodyC<DataT>::RecvData(), Called for Pos=" << pos << "\n";
    RWLockHoldC hold(rwlock,false);
    data = dat;
    flag = 0;
    hold.Unlock();
    recieved.Post();
    //cerr << "NetISPortBodyC<DataT>::RecvData(), Done for Pos=" << pos << "\n";
    return true;
  }

  //: Get next piece of data.
  
  template<class DataT>
  bool NetISPortBodyC<DataT>::Get(DataT &buf) {
    //cerr << "NetISPortBodyC<DataT>::Get(DataT &), Called for Pos=" << at << "\n";
    if(gotEOS)
      return false;
    RWLockHoldC hold(rwlock,true);
    hold.Unlock();
    ep.Send(4,at);
    recieved.Wait();
    hold.LockRd();
    if(flag != 0)
      return false;
    buf = data;
    if(at != (UIntT)(-1))
      at++;
    //cerr << "NetISPortBodyC<DataT>::Get(DataT &), Done for Pos=" << at << "\n";
    return true;
  }
  
  template<class DataT>
  DataT NetISPortBodyC<DataT>::Get() {
    DataT tmp;
    if(!Get(tmp))
      throw DataNotReadyC("Get failed. ");
    return tmp;
  }

  
  
}


#endif