node.java

pastry的java实现的2.0b版

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"FreePastry" Peer-to-Peer Application Development Substrate 

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package rice.p2p.commonapi;

import rice.environment.Environment;

/**
 * @(#) Node.java Interface which represents a node in a peer-to-peer system,
 * regardless of the underlying protocol. This represents a factory, in a sense,
 * that will give a application an Endpoint which it can use to send and receive
 * messages.
 *
 * @version $Id: Node.java 3274 2006-05-15 16:17:47Z jeffh $
 * @author Alan Mislove
 * @author Peter Druschel
 */
public interface Node {

  /**
   * This returns a Endpoint specific to the given application and instance name
   * to the application, which the application can then use in order to send an
   * receive messages. This method abstracts away the port number for this
   * application, generating a port by hashing together the class name with the
   * instance name to generate a unique port. Developers who wish for more
   * advanced behavior can specify their port manually, by using the second
   * constructor below.
   *
   * @param application The Application
   * @param instance An identifier for a given instance
   * @return The endpoint specific to this applicationk, which can be used for
   *      message sending/receiving. Endpoint is already registered.
   * @deprecated use buildEndpoint(), then call Endpoint.register(), fixes
   *      synchronization problems, related to implicit behavior
   */
  public Endpoint registerApplication(Application application, String instance);

  /**
   * This returns a Endpoint specific to the given application and instance name
   * to the application, which the application can then use in order to send an
   * receive messages. This method allows advanced developers to specify which
   * "port" on the node they wish their application to register as. This "port"
   * determines which of the applications on top of the node should receive an
   * incoming message. NOTE: Use of this method of registering applications is
   * recommended only for advanced users - 99% of all applications should just
   * use the other registerApplication
   *
   * @return The endpoint specific to this applicationk, which can be used for
   *      message sending/receiving.
   */
//  public Endpoint registerApplication(Application application, int code);

  /**
   * Returns the Id of this node
   *
   * @return This node's Id
   */
  public Id getId();

  /**
   * Returns a factory for Ids specific to this node's protocol.
   *
   * @return A factory for creating Ids.
   */
  public IdFactory getIdFactory();

  /**
   * Returns a handle to the local node. This node handle is serializable, and
   * can therefore be sent to other nodes in the network and still be valid.
   *
   * @return A NodeHandle referring to the local node.
   */
  public NodeHandle getLocalNodeHandle();

  /**
   * Returns the environment. This allows the nodes to be virtualized within the
   * JVM
   *
   * @return the environment for this node/app.
   */
  public Environment getEnvironment();

  /**
   * Same as register application, but returns an unregistered Endpoint. This
   * allows the application to finish initialization that may require the
   * endpoint before it receives messages from the network and notification of
   * changes. When then application is ready, it must call endpoint.register()
   * to receive messages.
   *
   * @param application
   * @param instance
   * @return
   */
  public Endpoint buildEndpoint(Application application, String instance);
}