floodidqueue.java

来自「DSr project for the java applications」· Java 代码 · 共 78 行

package dsr;




//this class is implemented to store the info about the RREQ packets that have been sent out
//so that we don't have duplicate entries floating around in the network
import java.io.*;
import java.util.*;
import java.net.*;

public class FloodIDQueue {
  public static List IDQueue;      //List

  //constructor
  public FloodIDQueue() {
    IDQueue = Collections.synchronizedList(new LinkedList());
  }

  //print out the entries in the flood Queue
  public static void PrintFloodIDQueue() {
    Iterator r = IDQueue.iterator();
    System.out.println("************************************************************************");
    System.out.println("The entries in the flood id queue are");
    System.out.println("************************************************************************");
    while (r.hasNext()) {
      System.out.println(((FloodIDQueueEntry)r.next()).toString());
    }
    System.out.println("************************************************************************");
  }

  //find a particular Entry in the queue. Returns the entry if found, null otherwise
  public static FloodIDQueueEntry findFloodIDQueueEntry(InetAddress dstIP, int floodID) {
    FloodIDQueueEntry tmpEntry = new FloodIDQueueEntry();
    for (int i = 0; i < IDQueue.size(); ++i) {
      tmpEntry = (FloodIDQueueEntry)IDQueue.get(i);
      //the combination of destination address and the flood ID uniquely identifies an entry
      if (tmpEntry.dstIP.equals(dstIP) && tmpEntry.floodID == floodID)
        return tmpEntry;
    }
    return null;
  }

  //clean up the whole queue
  public void cleanUpFloodIDQueue() {
    IDQueue.clear();
  }

  //insert an entry into the FloodID Queue
  public static void insertFloodIDQueueEntry(InetAddress srcIP, InetAddress dstIP, int floodID,
      long lifetime) {
    FloodIDQueueEntry tmpEntry = new FloodIDQueueEntry(srcIP, dstIP, lifetime);
    IDQueue.add(tmpEntry);
  }

  //find out if this entry is valid. After the lifetime is over the entry is no more valid
  public boolean isFloodIDQueueEntryValid(FloodIDQueueEntry tmpEntry) {
    if (tmpEntry.lifetime < System.currentTimeMillis())
      return false;
    else
      return true;
  }

  //goes through the list and deletes the entries that are no more valid
  public void deleteInvalidFloodIDQueueEntry() {
    FloodIDQueueEntry tmpEntry = new FloodIDQueueEntry();
    for (int i=0; i < IDQueue.size(); ++i) {
      tmpEntry = (FloodIDQueueEntry)IDQueue.get(i);
      if (tmpEntry.lifetime < System.currentTimeMillis())
        IDQueue.remove(i);
    }
  }

  //delete this particular entry in the food ID queue
  public void deleteThisFloodIDQueueEntry(FloodIDQueueEntry tmpEntry) {
    IDQueue.remove(tmpEntry);
  }
}