directappsocket.java

pastry的java实现的2.0b版

/*************************************************************************

"FreePastry" Peer-to-Peer Application Development Substrate 

Copyright 2002, Rice University. All rights reserved.

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- Redistributions of source code must retain the above copyright
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- Redistributions in binary form must reproduce the above copyright
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- Neither  the name  of Rice  University (RICE) nor  the names  of its
contributors may be  used to endorse or promote  products derived from
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This software is provided by RICE and the contributors on an "as is"
basis, without any representations or warranties of any kind, express
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********************************************************************************/
/*
 *  Created on Jan 30, 2006
 */
package rice.pastry.direct;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.util.*;

import rice.p2p.commonapi.*;
import rice.p2p.commonapi.appsocket.*;
import rice.p2p.commonapi.exception.*;
import rice.pastry.client.PastryAppl;

/**
 * DESCRIBE THE CLASS
 *
 * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
 * @author jeffh
 */
public class DirectAppSocket {

  DirectNodeHandle acceptorNodeHandle;

  PastryAppl acceptorAppl;

  AppSocketReceiver connectorReceiver;
  PastryAppl connectorAppl;

  NetworkSimulator simulator;

  DirectAppSocketEndpoint acceptorEndpoint;
  DirectAppSocketEndpoint connectorEndpoint;
  /**
   * DESCRIBE THE FIELD
   */
  public final static byte[] EOF = new byte[0];

  /**
   * The sum the simulated read/write buffers for one direction of a socket
   */
  private final static int MAX_BYTES_IN_FLIGHT = 10000;

  /**
   * Constructor for DirectAppSocket.
   *
   * @param acceptor DESCRIBE THE PARAMETER
   * @param connector DESCRIBE THE PARAMETER
   * @param connectorAppl DESCRIBE THE PARAMETER
   * @param simulator DESCRIBE THE PARAMETER
   */
  DirectAppSocket(DirectNodeHandle acceptor, AppSocketReceiver connector, PastryAppl connectorAppl, NetworkSimulator simulator) {
    this.acceptorNodeHandle = acceptor;
    DirectPastryNode acceptorNode = acceptor.getRemote();
    this.connectorReceiver = connector;
    this.connectorAppl = connectorAppl;
    this.simulator = simulator;
    acceptorAppl = acceptorNode.getMessageDispatch().getDestinationByAddress(connectorAppl.getAddress());

    acceptorEndpoint = new DirectAppSocketEndpoint(acceptor);
    connectorEndpoint = new DirectAppSocketEndpoint(connectorAppl.getNodeHandle());
    acceptorEndpoint.setCounterpart(connectorEndpoint);
    connectorEndpoint.setCounterpart(acceptorEndpoint);

  }

  /**
   * Gets the AcceptorDelivery attribute of the DirectAppSocket object
   *
   * @return The AcceptorDelivery value
   */
  public Delivery getAcceptorDelivery() {
    return new AcceptorDelivery();
  }

  /**
   * DESCRIBE THE CLASS
   *
   * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
   * @author jeffh
   */
  class DirectAppSocketEndpoint implements AppSocket {
    DirectAppSocketEndpoint counterpart;

    AppSocketReceiver reader;
    AppSocketReceiver writer;
    NodeHandle localNodeHandle;

    boolean inputClosed;
    boolean outputClosed;

    // these three are tightly related, and should only be modified in synchronized methods on DirectAppSocketEndpoint.this
    // bytes that are either in deliveries, or in the local buffer
    int bytesInFlight = 0;
    /**
     * of byte[]
     */
    LinkedList byteDeliveries = new LinkedList();
    /**
     * The offset of the first delivery, in case the reader didn't have enough
     * space to read everything available.
     */
    int firstOffset = 0;


    /**
     * Constructor for DirectAppSocketEndpoint.
     *
     * @param localNodeHandle DESCRIBE THE PARAMETER
     */
    public DirectAppSocketEndpoint(NodeHandle localNodeHandle) {
      this.localNodeHandle = localNodeHandle;
    }

    /**
     * Gets the RemoteNodeHandle attribute of the DirectAppSocketEndpoint object
     *
     * @return The RemoteNodeHandle value
     */
    public NodeHandle getRemoteNodeHandle() {
      return counterpart.localNodeHandle;
    }

    /**
     * Sets the Counterpart attribute of the DirectAppSocketEndpoint object
     *
     * @param counterpart The new Counterpart value
     */
    public void setCounterpart(DirectAppSocketEndpoint counterpart) {
      this.counterpart = counterpart;
    }

    /**
     * DESCRIBE THE METHOD
     *
     * @param dsts DESCRIBE THE PARAMETER
     * @param offset DESCRIBE THE PARAMETER
     * @param length DESCRIBE THE PARAMETER
     * @return DESCRIBE THE RETURN VALUE
     */
    public long read(ByteBuffer[] dsts, int offset, int length) {
      int lengthRead = 0;

      synchronized (this) {
        if (byteDeliveries.getFirst() == EOF) {
          inputClosed = true;
          return -1;
        }
        Iterator i = byteDeliveries.iterator();
        // loop over all messages to be delivered
        while (i.hasNext()) {
          byte[] msg = (byte[]) i.next();

          // loop through all the dsts, and fill them with the current message if possible
          for (int dstCtr = offset; dstCtr < offset + length; dstCtr++) {
            ByteBuffer curBuffer = dsts[dstCtr];
            int lengthToPut = curBuffer.remaining();
            if (lengthToPut > (msg.length - firstOffset)) {
              lengthToPut = msg.length - firstOffset;
            }

            curBuffer.put(msg, firstOffset, lengthToPut);
            firstOffset += lengthToPut;
            lengthRead += lengthToPut;

            // we finished a message
            if (firstOffset == msg.length) {
              break;
            }
            // for distCtr loop

            // optimization: if we are here then there must be no more remaining in curBuffer
            offset = dstCtr + 1;
          }

          // see if we finished a message
          if (firstOffset == msg.length) {
            i.remove();
            firstOffset = 0;
          } else {
            break;
            // i.hasNext() loop
          }
        }
      }
      // synchronized(this)

      bytesInFlight -= lengthRead;
      simulator.enqueueDelivery(
        new Delivery() {
          public void deliver() {
            notifyCanWrite();
          }
        });
      return lengthRead;
    }

    /**
     * DESCRIBE THE METHOD
     *
     * @param srcs DESCRIBE THE PARAMETER
     * @param offset DESCRIBE THE PARAMETER
     * @param length DESCRIBE THE PARAMETER
     * @return DESCRIBE THE RETURN VALUE
     * @exception IOException DESCRIBE THE EXCEPTION
     */
    public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
      if (outputClosed) {
        throw new ClosedChannelException();
      }
      int availableToWrite = 0;
      for (int i = offset; i < offset + length; i++) {
        availableToWrite += srcs[i].remaining();
      }

      int lengthToWrite;
      synchronized (counterpart) {
        lengthToWrite = MAX_BYTES_IN_FLIGHT - counterpart.bytesInFlight;
        if (lengthToWrite > availableToWrite) {
          lengthToWrite = availableToWrite;
        }
        counterpart.bytesInFlight += lengthToWrite;
      }

      final byte[] msg = new byte[lengthToWrite];
      int remaining = lengthToWrite;
      int i = offset;
      while (remaining > 0) {
        int lengthToReadFromBuffer = srcs[i].remaining();
        if (remaining < lengthToReadFromBuffer) {
          lengthToReadFromBuffer = remaining;
        }
        srcs[i].get(msg, lengthToWrite - remaining, lengthToReadFromBuffer);
        remaining -= lengthToReadFromBuffer;
        i++;
      }

      simulator.enqueueDelivery(
        new Delivery() {
          public void deliver() {
            counterpart.addToReadQueue(msg);
          }
        });
      return lengthToWrite;
    }

    /**
     * only called on simulator thread
     *
     * @param msg The feature to be added to the ToReadQueue attribute
     */
    protected void addToReadQueue(byte[] msg) {
      synchronized (this) {
        byteDeliveries.addLast(msg);
      }
      notifyCanRead();
    }

    /**
     * must be called on the simulator thread
     */
    protected void notifyCanWrite() {
      if (writer == null) {
        return;
      }
      if (counterpart.bytesInFlight < MAX_BYTES_IN_FLIGHT) {
        AppSocketReceiver temp = writer;
        writer = null;
        temp.receiveSelectResult(this, false, true);
      }
    }

    /**
     * must be called on the simulator thread
     */
    protected void notifyCanRead() {
      if (byteDeliveries.isEmpty()) {
        return;
      }
      if (reader != null) {
        AppSocketReceiver temp = reader;
        reader = null;
        temp.receiveSelectResult(this, true, false);
      }
    }

    /**
     * Can be called on any thread
     *
     * @param wantToRead DESCRIBE THE PARAMETER
     * @param wantToWrite DESCRIBE THE PARAMETER
     * @param timeout DESCRIBE THE PARAMETER
     * @param receiver DESCRIBE THE PARAMETER
     */
    public void register(boolean wantToRead, boolean wantToWrite, int timeout,
                         AppSocketReceiver receiver) {
      if (wantToWrite) {
        writer = receiver;

        simulator.enqueueDelivery(
          new Delivery() {
            public void deliver() {
              notifyCanWrite();
              // only actually notifies if proper at the time
            }
          });
      }

      if (wantToRead) {
        reader = receiver;

        simulator.enqueueDelivery(
          new Delivery() {
            public void deliver() {
              notifyCanRead();
              // only actually notifies if proper at the time
            }
          });
      }
    }

    /**
     * DESCRIBE THE METHOD
     */
    public void shutdownOutput() {
      outputClosed = true;
      simulator.enqueueDelivery(
        new Delivery() {
          public void deliver() {
            counterpart.addToReadQueue(EOF);
          }
        });
    }

    /**
     * DESCRIBE THE METHOD
     */
    public void shutdownInput() {
      inputClosed = true;
    }

    /**
     * DESCRIBE THE METHOD
     */
    public void close() {
      shutdownOutput();
      shutdownInput();
    }
  }


  /**
   * DESCRIBE THE CLASS
   *
   * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
   * @author jeffh
   */
  class AcceptorDelivery implements Delivery {
    /**
     * DESCRIBE THE METHOD
     */
    public void deliver() {
      if (acceptorNodeHandle.isAlive()) {
        if (acceptorAppl == null) {
          simulator.enqueueDelivery(new ConnectorExceptionDelivery(new AppNotRegisteredException()));
        } else {
          if (acceptorAppl.receiveSocket(acceptorEndpoint)) {
            simulator.enqueueDelivery(new ConnectorDelivery());
          } else {
            simulator.enqueueDelivery(new ConnectorExceptionDelivery(new NoReceiverAvailableException()));
          }
        }
      } else {
        simulator.enqueueDelivery(new ConnectorExceptionDelivery(new NodeIsDeadException()));
      }
    }
  }

  /**
   * DESCRIBE THE CLASS
   *
   * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
   * @author jeffh
   */
  class ConnectorDelivery implements Delivery {
    /**
     * DESCRIBE THE METHOD
     */
    public void deliver() {
      if (connectorAppl.getNodeHandle().isAlive()) {
        connectorReceiver.receiveSocket(connectorEndpoint);
      } else {
        System.out.println("NOT IMPLEMENTED: Connector died during application socket initiation.");
//        simulator.enqueueDelivery(new ConnectorExceptionDelivery(new NodeIsDeadException(acceptorNodeHandle)));
      }
    }
  }

  /**
   * DESCRIBE THE CLASS
   *
   * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
   * @author jeffh
   */
  class ConnectorExceptionDelivery implements Delivery {
    Exception e;

    /**
     * Constructor for ConnectorExceptionDelivery.
     *
     * @param e DESCRIBE THE PARAMETER
     */
    public ConnectorExceptionDelivery(Exception e) {
      this.e = e;
    }

    /**
     * DESCRIBE THE METHOD
     */
    public void deliver() {
      connectorReceiver.receiveException(null, e);
    }
  }
}