output-slot.cpp

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/*
  OutputSlot  -  capability to transfer data to a physical output
 
   Copyright (C)
     2011,            Hermann Vosseler <Ichthyostega@web.de>
 
 **Lumiera** is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
 Free Software Foundation; either version 2 of the License, or (at your
 option) any later version. See the file COPYING for further details.
 
* *****************************************************************/
 
 
#include "lib/error.hpp"
#include "steam/play/output-slot.hpp"
#include "steam/play/output-slot-connection.hpp"
 
#include <vector>
 
 
namespace steam {
namespace play {
  
  using std::vector;
  
  namespace error = lumiera::error;
  
  
  
  
  OutputSlot::~OutputSlot() { }  // emit VTables here....
  
  OutputSlot::Allocation::~Allocation() { }
  
  OutputSlot::Connection::~Connection() { }
  
  
  
  
  
  bool
  OutputSlot::isFree()  const
  {
    return not this->state_;
  }
  
  
  OutputSlot::Allocation&
  OutputSlot::allocate()
  {
    if (not isFree())
      throw error::Logic ("Attempt to open/allocate an OutputSlot already in use.");
    
    state_.reset (this->buildState());
    return *state_;
  }
  
  
  void
  OutputSlot::disconnect()
  {
    if (not isFree())
      state_.reset(0);
  }
  
  
  
  /* === DataSink frontend === */
  
  BuffHandle
  DataSink::lockBufferFor(FrameID frameNr)
  {
    return impl().claimBufferFor(frameNr);
  }
  
  
  void
  DataSink::emit (FrameID frameNr, BuffHandle const& data2emit, TimeValue currentTime)
  {
    OutputSlot::Connection& connection = impl();
    if (connection.isTimely(frameNr,currentTime))
      connection.transfer(data2emit);
    else
      connection.discard(data2emit);
  }
  
  
  
  
}} // namespace steam::play