multipeeruploader.java

这是一个基于java编写的torrent的P2P源码

      return 0;  //not allowed to write
    }
        
    HashMap connections_to_notify_of_exception = new HashMap();
    ArrayList manual_notifications = new ArrayList();
    
    int num_bytes_remaining = num_bytes_to_write;    
    
    try {
      lists_lock.enter();
      
      int num_unusable_connections = 0;
      
      while( num_bytes_remaining > 0 && num_unusable_connections < ready_connections.size() ) {
    	NetworkConnectionBase conn = (NetworkConnectionBase)ready_connections.removeFirst();
        
        if( !conn.getTransportBase().isReadyForWrite( waiter ) ) {  //not yet ready for writing
          ready_connections.addLast( conn );  //re-add to end as currently unusable
          num_unusable_connections++;
          continue;  //move on to the next connection
        }
        
        int total_size = conn.getOutgoingMessageQueue().getTotalSize();
        
        if( total_size < 1 ) {  //oops, all messages have been removed
          addToWaitingList( conn );
          continue;  //move on to the next connection
        }
        
        int mss_size = conn.getMssSize();
        int num_bytes_allowed = num_bytes_remaining > mss_size ? mss_size : num_bytes_remaining;  //allow a single full packet at most
        int num_bytes_available = total_size > mss_size ? mss_size : total_size;  //allow a single full packet at most
        
        if( num_bytes_allowed >= num_bytes_available ) { //we're allowed enough (for either a full packet or to drain any remaining data)
          int written = 0;
          try {
            written = conn.getOutgoingMessageQueue().deliverToTransport( num_bytes_available, true );
                   
            if( written > 0 ) {  
              manual_notifications.add( conn );  //register it for manual listener notification
            }
            
            boolean has_urgent_data = conn.getOutgoingMessageQueue().hasUrgentMessage();
            int remaining = conn.getOutgoingMessageQueue().getTotalSize();
            
            if( remaining >= mss_size || has_urgent_data ) {  //still has a full packet's worth, or has urgent data
              ready_connections.addLast( conn );  //re-add to end for further writing
              num_unusable_connections = 0;  //reset the unusable count so that it has a chance to try this connection again in the loop
            }
            else {  //connection does not have enough for a full packet, so remove and place into waiting list
              addToWaitingList( conn );
            }
          }
          catch( Throwable e ) {  //write exception, so move to waiting list while it waits for removal
            
            if( AEDiagnostics.TRACE_CONNECTION_DROPS ) {
              if( e.getMessage() == null ) {
                Debug.out( "null write exception message: ", e );
              }
              else {
                if( e.getMessage().indexOf( "An existing connection was forcibly closed by the remote host" ) == -1 &&
                    e.getMessage().indexOf( "Connection reset by peer" ) == -1 &&
                    e.getMessage().indexOf( "Broken pipe" ) == -1 &&
                    e.getMessage().indexOf( "An established connection was aborted by the software in your host machine" ) == -1 ) {
                  
                  System.out.println( "MP: write exception [" +conn.getTransportBase().getDescription()+ "]: " +e.getMessage() );
                }
              }
            }
            
            connections_to_notify_of_exception.put( conn, e );  //do exception notification outside of sync'd block
            addToWaitingList( conn );
          }
          
          num_bytes_remaining -= written;
        }
        else {  //we're not allowed enough to maximize the packet payload
          ready_connections.addLast( conn );  //re-add to end as currently unusable
          num_unusable_connections++;
          continue;  //move on to the next connection
        }
      }
    }
    finally {
      lists_lock.exit();
    }
    
    //manual queue listener notifications
    for( int i=0; i < manual_notifications.size(); i++ ) {
      NetworkConnectionBase conn = (NetworkConnectionBase)manual_notifications.get( i );
      conn.getOutgoingMessageQueue().doListenerNotifications();
    }
    
    //exception notifications
    for( Iterator i = connections_to_notify_of_exception.entrySet().iterator(); i.hasNext(); ) {
      Map.Entry entry = (Map.Entry)i.next();
      NetworkConnectionBase conn = (NetworkConnectionBase)entry.getKey();
      Throwable exception = (Throwable)entry.getValue();
      conn.notifyOfException( exception );
    }
    
    int num_bytes_written = num_bytes_to_write - num_bytes_remaining;
    if( num_bytes_written > 0 ) {
      rate_handler.bytesProcessed( num_bytes_written );
    }
    
    return num_bytes_written;
  }
  
  
  
  /**
   * Does this entity have data ready for writing.
   * @return true if it has data to send, false if empty
   */
  /*
  public boolean hasWriteDataAvailable() {
    if( ready_connections.isEmpty() )  return false;
    return true;
  }
  */
  
  
  
  private static class PeerData {
    private OutgoingMessageQueue.MessageQueueListener queue_listener;
    private long last_message_added_time;
  }
  
  public long
  getBytesReadyToWrite()
  {
	  long	total = 0;
	  
	  try {
		  lists_lock.enter();

		  for( Iterator i = waiting_connections.keySet().iterator(); i.hasNext(); ) {
			 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  total += conn.getOutgoingMessageQueue().getTotalSize();
		  }
		  
		  for( Iterator i = ready_connections.iterator(); i.hasNext(); ) {
				 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  total += conn.getOutgoingMessageQueue().getTotalSize();
		  }
	  }finally{
		  
		  lists_lock.exit();
	  }
	  
	  return( total );
  }
  
  public int
  getConnectionCount()
  {
	  return( waiting_connections.size() + ready_connections.size());
  }
  
  public int
  getReadyConnectionCount(
	EventWaiter	waiter )
  {
	  int	total = 0;
	  
	  try {
		  lists_lock.enter();

		  for( Iterator i = waiting_connections.keySet().iterator(); i.hasNext(); ) {
			 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  if ( conn.getTransportBase().isReadyForWrite(waiter)){
				  
				  total++;
			  }
		  }
		  
		  for( Iterator i = ready_connections.iterator(); i.hasNext(); ) {
				 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  if ( conn.getTransportBase().isReadyForWrite(waiter)){
				  
				  total++;
			  }
		  }
	  }finally{
		  
		  lists_lock.exit();
	  }
	  
	  return( total );
  }
  
  //////////////// RateControlledWriteEntity implementation ////////////////////
  
  public boolean canProcess( EventWaiter waiter ) {
    flushCheck();  //since this method is called repeatedly from a loop, we can use it to check flushes

    if( ready_connections.isEmpty() )  return false;  //no data to send
    if( rate_handler.getCurrentNumBytesAllowed() < 1/*NetworkManager.getTcpMssSize()*/ )  return false;
    return true;
  }
  
  public boolean doProcessing( EventWaiter waiter ) {
    int num_bytes_allowed = rate_handler.getCurrentNumBytesAllowed();
    if( num_bytes_allowed < 1 )  return false;
    
    return write( waiter, num_bytes_allowed ) > 0 ? true : false;
  }

  public int getPriority() {
    return RateControlledEntity.PRIORITY_HIGH;
  }
  
  public String
  getString()
  {
	  String	str = "can_process=" + canProcess(null) + ",bytes_allowed=" + rate_handler.getCurrentNumBytesAllowed() + ", waiting ";
  
	  try {
		  lists_lock.enter();

		  for( Iterator i = waiting_connections.keySet().iterator(); i.hasNext(); ) {
			 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  str += "," + conn.getString();
		  }
		  
		  str += ": ready ";
		  
		  for( Iterator i = ready_connections.iterator(); i.hasNext(); ) {
				 
			  NetworkConnectionBase conn = (NetworkConnectionBase)i.next();
			  
			  str += "," + conn.getString();
		  }
	  }finally{
		  
		  lists_lock.exit();
	  }
	  
	  return( "MPU: " + str );
  }  
}