+++ /dev/null
-/* Copyright (c) 2012-2023. The SimGrid Team.
- * All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-package dht.kademlia;
-
-import org.simgrid.msg.Host;
-
-import org.simgrid.msg.Msg;
-import org.simgrid.msg.Comm;
-import org.simgrid.msg.Task;
-import org.simgrid.msg.Process;
-import org.simgrid.msg.MsgException;
-
-public class Node extends Process {
- protected int id;
- protected RoutingTable table;
- protected int deadline;
- protected int findNodeSuccedded = 0;
- protected int findNodeFailed = 0;
- protected Comm comm;
-
- public Node(Host host, String name, String[]args) {
- super(host,name,args);
- }
-
- @Override
- public void main(String[] args) throws MsgException {
- //Check the number of arguments.
- if (args.length != 2 && args.length != 3) {
- Msg.info("Wrong argument count.");
- return;
- }
- this.id = Integer.parseInt(args[0]);
- this.table = new RoutingTable(this.id);
-
- if (args.length == 3) {
- this.deadline = Integer.parseInt(args[2]);
- Msg.info("Hi, I'm going to join the network with the id " + id + "!");
- if (joinNetwork(Integer.parseInt(args[1]))) {
- this.mainLoop();
- }
- else {
- Msg.info("I couldn't join the network :(");
- }
- }
- else {
- this.deadline = Integer.parseInt(args[1]);
- Msg.info("Hi, I'm going to create the network with the id " + id + "!");
- table.update(this.id);
- this.mainLoop();
- }
- Msg.debug("I'm leaving the network");
- Msg.debug("Here is my routing table:" + table);
- }
-
- public void mainLoop() {
- double nextLookupTime = Msg.getClock() + Common.RANDOM_LOOKUP_INTERVAL;
- while (Msg.getClock() < this.deadline) {
- try {
- if (comm == null) {
- comm = Task.irecv(Integer.toString(id));
- }
- if (!comm.test()) {
- if (Msg.getClock() >= nextLookupTime) {
- randomLookup();
- nextLookupTime += Common.RANDOM_LOOKUP_INTERVAL;
- } else {
- waitFor(1);
- }
- } else {
- Task task = comm.getTask();
- handleTask(task);
- comm = null;
- }
- }
- catch (Exception e) {
- Msg.debug("Caught exception: " + e);
- }
- }
- Msg.info(findNodeSuccedded + "/" + (findNodeSuccedded + findNodeFailed) + " FIND_NODE have succeeded.");
- }
-
- /**
- * @brief Try to make the node join the network
- * @param idKnown Id of someone we know in the system
- */
- public boolean joinNetwork(int idKnown) {
- boolean answerGot = false;
- double timeBegin = Msg.getClock();
- Msg.debug("Joining the network knowing " + idKnown);
- //Add ourselves and the node we know to our routing table
- table.update(this.id);
- table.update(idKnown);
- //Send a "FIND_NODE" to the node we know.
- sendFindNode(idKnown,this.id);
- //Wait for the answer.
- int trials = 0;
-
- do {
- try {
- if (comm == null) {
- comm = Task.irecv(Integer.toString(id));
- }
- if (comm != null) {
- if (!comm.test()) {
- waitFor(1);
- } else {
- Task task = comm.getTask();
- if (task instanceof FindNodeAnswerTask) {
- //Retrieve the node list and ping them
- FindNodeAnswerTask answerTask = (FindNodeAnswerTask)task;
- Answer answer = answerTask.getAnswer();
- answerGot = true;
- if (answer.getDestinationId() == this.id) {
- //Ping everyone in the list
- for (Contact c : answer.getNodes()) {
- table.update(c.getId());
- }
- }
- } else {
- handleTask(task);
- }
- comm = null;
- }
- }
- }
- catch (Exception ex) {
- trials++;
- Msg.info("FIND_NODE failed");
- }
- } while (!answerGot && trials < Common.MAX_JOIN_TRIALS);
- /* Second step: Send a FIND_NODE in a node in each bucket */
- int bucketId = table.findBucket(idKnown).getId();
- for (int i = 0; ((bucketId - i) > 0 ||
- (bucketId + i) <= Common.IDENTIFIER_SIZE) &&
- i < Common.JOIN_BUCKETS_QUERIES; i++) {
- if (bucketId - i > 0) {
- int idInBucket = table.getIdInPrefix(this.id,bucketId - i);
- this.findNode(idInBucket,false);
- }
- if (bucketId + i <= Common.IDENTIFIER_SIZE) {
- int idInBucket = table.getIdInPrefix(this.id,bucketId + i);
- findNode(idInBucket,false);
- }
- }
- Msg.debug("Time spent:" + (Msg.getClock() - timeBegin));
- return answerGot;
- }
-
- /* Send a request to find a node in the node's routing table. */
- public boolean findNode(int destination, boolean counts) {
- int queries;
- int answers;
- int nodesAdded;
- boolean destinationFound;
- int steps = 0;
- double timeBeginReceive;
- double timeout;
- double globalTimeout = Msg.getClock() + Common.FIND_NODE_GLOBAL_TIMEOUT;
- //Build a list of the closest nodes we already know.
- Answer nodeList = table.findClosest(destination);
- Msg.verb("Doing a FIND_NODE on " + destination);
- do {
- timeBeginReceive = Msg.getClock();
- answers = 0;
- queries = this.sendFindNodeToBest(nodeList);
- nodesAdded = 0;
- timeout = Msg.getClock() + Common.FIND_NODE_TIMEOUT;
- steps++;
- do {
- try {
- if (comm == null) {
- comm = Task.irecv(Integer.toString(id));
- }
- if (!comm.test()) {
- waitFor(1);
- } else {
- Task task = comm.getTask();
- if (task instanceof FindNodeAnswerTask) {
- FindNodeAnswerTask answerTask = (FindNodeAnswerTask)task;
- //Check if we received what we are looking for.
- if (answerTask.getDestinationId() == destination) {
- table.update(answerTask.getSenderId());
- //Add the answer to our routing table
- for (Contact c: answerTask.getAnswer().getNodes()) {
- table.update(c.getId());
- }
- answers++;
-
- nodesAdded = nodeList.merge(answerTask.getAnswer());
- } else {
- /* If it's not our answer, we answer to the node that has queried us anyway */
- handleTask(task);
- //Update the timeout if it's not our answer.
- timeout += Msg.getClock() - timeBeginReceive;
- timeBeginReceive = Msg.getClock();
- }
- } else {
- handleTask(task);
- timeout += Msg.getClock() - timeBeginReceive;
- timeBeginReceive = Msg.getClock();
- }
- comm = null;
- }
- }
- catch (Exception e) {
- comm = null;
- }
- } while (answers < queries && Msg.getClock() < timeout);
- destinationFound = nodeList.destinationFound();
- } while (!destinationFound && (nodesAdded > 0 || answers == 0) && Msg.getClock() < globalTimeout
- && steps < Common.MAX_STEPS);
-
- if (destinationFound) {
- if (counts) {
- findNodeSuccedded++;
- }
- Msg.debug("Find node on " + destination + " succeeded");
- } else {
- Msg.debug("Find node on " + destination + " failed");
- Msg.debug("Queried " + queries + " nodes to find " + destination);
- Msg.debug(nodeList.toString());
- if (counts) {
- findNodeFailed++;
- }
- }
- return destinationFound;
- }
-
- /**
- * @brief Sends a "FIND_NODE" request (task) to a node we know.
- * @param id Id of the node we are querying
- * @param destination id of the node we are trying to find.
- */
- public void sendFindNode(int id, int destination) {
- Msg.debug("Sending a FIND_NODE to " + Integer.toString(id) + " to find " + destination );
- FindNodeTask task = new FindNodeTask(this.id,destination);
- task.dsend(Integer.toString(id));
- }
-
- /** Sends a "FIND_NODE" request to the best "alpha" nodes in a node list */
- public int sendFindNodeToBest(Answer nodeList) {
- int destination = nodeList.getDestinationId();
- int i;
- for (i = 0; i < Common.ALPHA && i < nodeList.size(); i++) {
- Contact node = nodeList.getNodes().get(i);
- if (node.getId() != this.id) {
- this.sendFindNode(node.getId(),destination);
- }
- }
- return i;
- }
-
- public void randomLookup() {
- findNode(0,true);
- }
-
- /**
- * @brief Handles an incoming task
- * @param task The task we need to handle
- */
- public void handleTask(Task task) {
- if (task instanceof KademliaTask) {
- table.update(((KademliaTask) task).getSenderId());
- if (task instanceof FindNodeTask) {
- handleFindNode((FindNodeTask)task);
- }
- }
- }
-
- public void handleFindNode(FindNodeTask task) {
- Msg.debug("Received a FIND_NODE from " + task.getSenderId());
- Answer answer = table.findClosest(task.getDestination());
- FindNodeAnswerTask taskToSend = new FindNodeAnswerTask(this.id,task.getDestination(),answer);
- taskToSend.dsend(Integer.toString(task.getSenderId()));
- }
-}
