pepieceimpl.java

这是一个基于java编写的torrent的P2P源码

    public int getNbUnrequested()
    {
        int result =0;
        final boolean[] written =dmPiece.getWritten();
        for (int i =0; i <nbBlocks; i++ )
        {
            if (!downloaded[i] &&requested[i] ==null &&(written ==null ||!written[i]))
                result++;
        }
        return result;
    }

	/**
	 * Assumption - single threaded with getAndMarkBlock
	 */
	public boolean setRequested(PEPeer peer, int blockNumber)
	{
		if (!downloaded[blockNumber])
		{
			requested[blockNumber] =peer.getIp();
			return true;
		}
		return false;
	}
	
	public boolean		
	isRequestable()
	{
		return( dmPiece.isDownloadable() && !( fully_downloaded || fully_requested ));
	}
	
	public int 
	getBlockSize(
		int blockNumber) 
	{
		if ( blockNumber == (nbBlocks - 1)){
			
			int	length = dmPiece.getLength();
			
			if ((length % DiskManager.BLOCK_SIZE) != 0){
				
				return( length % DiskManager.BLOCK_SIZE );
			}
		}
		
		return DiskManager.BLOCK_SIZE;
	}
    
    public int getBlockNumber(int offset)
    {
        return offset /DiskManager.BLOCK_SIZE;
    }
	
	public int getNbBlocks()
	{
		return nbBlocks;
	}

	public List getPieceWrites()
	{
		List result;
		try{
			class_mon.enter();
			
			result = new ArrayList(writes);
		}finally{
			
			class_mon.exit();
		}
		return result;
	}
	
	
	public List getPieceWrites(int blockNumber) {
		final List result;
		try{
			class_mon.enter();
			
			result = new ArrayList(writes);
			
		}finally{
			
			class_mon.exit();
		}
		final Iterator iter = result.iterator();
		while(iter.hasNext()) {
			final PEPieceWriteImpl write = (PEPieceWriteImpl) iter.next();
			if(write.getBlockNumber() != blockNumber)
				iter.remove();
		}
		return result;
	}
	
	
	public List getPieceWrites(PEPeer peer) {
		final List result;
		try{
			class_mon.enter();
			
			result = new ArrayList(writes);
		}finally{
			class_mon.exit();
		}
		final Iterator iter = result.iterator();
		while(iter.hasNext()) {
			PEPieceWriteImpl write = (PEPieceWriteImpl) iter.next();
			if(peer == null || ! peer.getIp().equals(write.getSender()))
				iter.remove();
		}
		return result;
	}
	
	public List 
	getPieceWrites( 
		String	ip ) 
	{
		final List result;
		
		try{
			class_mon.enter();
			
			result = new ArrayList(writes);
			
		}finally{
			
			class_mon.exit();
		}
		
		final Iterator iter = result.iterator();
		
		while(iter.hasNext()) {
			
			final PEPieceWriteImpl write = (PEPieceWriteImpl) iter.next();
			
			if ( !write.getSender().equals( ip )){
				
				iter.remove();
			}
		}
		
		return result;
	}

	public void reset()
	{
		dmPiece.reset();
		for (int i =0; i <nbBlocks; i++)
		{
            requested[i] =null;
			downloaded[i] =false;
			writers[i] =null;
		}
		fully_downloaded = false;
		time_last_download = 0;
		reservedBy =null;
		real_time_data=null;
	}

	public Object
	getRealTimeData()
	{
		return( real_time_data );
	}
	
	public void
	setRealTimeData(
		Object	o )
	{
		real_time_data = o;
	}
	
	protected void addWrite(PEPieceWriteImpl write) {
		try{
			class_mon.enter();
			
			writes.add(write);
			
		}finally{
			
			class_mon.exit();
		}
	}
	
	public void 
	addWrite(
		int blockNumber,
		String sender, 
		byte[] hash,
		boolean correct	)
	{
		addWrite( new PEPieceWriteImpl( blockNumber, sender, hash, correct ));
	}

	public String[] getWriters()
	{
		return writers;
	}

	public int getSpeed()
	{
		return speed;
	}

	public void setSpeed(int newSpeed)
	{
		speed =newSpeed;
	}

	public void
	setLastRequestedPeerSpeed(
		int		peerSpeed )
	{
		// Up the speed on this piece?
		if (peerSpeed > speed ){
			speed++;
		}
	}

	/**
	 * @return Returns the manager.
	 */
	public PEPeerManager getManager()
	{
		return manager;
	}

	public void setReservedBy(String peer)
	{
		reservedBy =peer;
	}

	public String getReservedBy()
	{
		return reservedBy;
	}

	/** for a block that's already downloadedt, mark up the piece
	 * so that the block will get downloaded again.  This is used
	 * when the piece fails hash-checking.
	 */
	public void reDownloadBlock(int blockNumber)
	{
		downloaded[blockNumber] =false;
		requested[blockNumber] =null;
		fully_downloaded = false;
		writers[blockNumber] = null;
		dmPiece.reDownloadBlock(blockNumber);
	}

	/** finds all blocks downloaded by the given address
	 * and marks them up for re-downloading 
	 * @param address String
	 */
	public void reDownloadBlocks(String address)
	{
		for (int i =0; i <writers.length; i++ )
		{
			final String writer =writers[i];

			if (writer !=null &&writer.equals(address))
				reDownloadBlock(i);
		}
	}

	public void setResumePriority(int p)
	{
		resumePriority =p;
	}

	public int getResumePriority()
	{
		return resumePriority;
	}

    /**
     * @return int of availability in the swarm for this piece
     * @see org.gudy.azureus2.core3.peer.PEPeerManager.getAvailability(int pieceNumber)
     */
    public int getAvailability()
    {
        return manager.getAvailability(dmPiece.getPieceNumber());
    }

    /** This support method returns how many blocks have already been
     * written from the dmPiece
     * @return int from dmPiece.getNbWritten()
     * @see org.gudy.azureus2.core3.disk.DiskManagerPiece.getNbWritten()
     */
    public int getNbWritten()
    {
        return dmPiece.getNbWritten();
    }
    
    /** This support method returns the dmPiece's written array
     * @return boolean[] from the dmPiece
     * @see org.gudy.azureus2.core3.disk.DiskManagerPiece.getWritten()
     */
    public boolean[] getWritten()
    {
        return dmPiece.getWritten();
    }
    public boolean isWritten()
    {
        return dmPiece.isWritten();
    }
    
    public boolean isWritten( int block)
    {
        return dmPiece.isWritten( block );
    }
	public int getPieceNumber()
	{
		return dmPiece.getPieceNumber();
	}

	public int getLength()
	{
		return dmPiece.getLength();
	}

	public void setRequestable()
	{
		fully_downloaded	= false;
		fully_requested		= false;
		
		dmPiece.setDownloadable();
	}
	
	public boolean isChecking()
	{
		return dmPiece.isChecking();
	}

	public String
	getString()
	{
		String	text  = "";
		
		text	+= ( isRequestable()?"reqable,":"" );
		text	+= "req=" + getNbRequests() + ",";
		text	+= ( isRequested()?"reqstd,":"" );
		text	+= ( isDownloaded()?"downed,":"" );
		text	+= ( getReservedBy()!=null?"resrv,":"" );
		text	+= "speed=" + getSpeed() + ",";
		text	+= "pri=" + getResumePriority();
		
		if ( text.endsWith(",")){
			text = text.substring(0,text.length()-1);
		}
		
		return( text );
	}
}