+++ /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 java.util.ArrayList;
-import java.util.Collections;
-
-import org.simgrid.msg.Msg;
-
-public class RoutingTable {
- /* Bucket list */
- private ArrayList<Bucket> buckets;
- /* Id of the routing table owner */
- private int id;
-
- public RoutingTable(int id) {
- this.id = id;
- buckets = new ArrayList<>();
- for (int i = 0; i < Common.IDENTIFIER_SIZE + 1; i++) {
- buckets.add(new Bucket(i));
- }
- }
-
- /**
- * @brief Returns an identifier which is in a specific bucket of a routing table
- * @param id id of the routing table owner
- * @param prefix id of the bucket where we want that identifier to be
- */
- public int getIdInPrefix(int id, int prefix) {
- if (prefix == 0) {
- return 0;
- }
- int identifier = 1;
- identifier = identifier << (prefix - 1);
- identifier = identifier ^ id;
- return identifier;
- }
-
- /* Returns the corresponding node prefix for a given id */
- public int getNodePrefix(int id) {
- for (int j = 0; j < 32; j++) {
- if ((id >> (32 - 1 - j) & 0x1) != 0) {
- return 32 - j;
- }
- }
- return 0;
- }
-
- /* Finds the corresponding bucket in a routing table for a given identifier */
- public Bucket findBucket(int id) {
- int xorNumber = id ^ this.id;
- int prefix = this.getNodePrefix(xorNumber);
- return buckets.get(prefix);
- }
-
- /* Updates the routing table with a new value. */
- public void update(int id) {
- Bucket bucket = this.findBucket(id);
- if (bucket.contains(id)) {
- Msg.debug("Updating " + Integer.toString(id) + " in my routing table");
- //If the element is already in the bucket, we update it.
- bucket.pushToFront(id);
- } else {
- Msg.debug("Adding " + id + " to my routing table");
- bucket.add(id);
- if (bucket.size() > Common.BUCKET_SIZE) {
- // TODO
- Msg.debug("Should ping the least seen guy and remove him if he is offline.");
- }
- }
- }
-
- /* Returns the closest notes we know to a given id */
- public Answer findClosest(int destinationId) {
- Answer answer = new Answer(destinationId);
- Bucket bucket = this.findBucket(destinationId);
- bucket.addToAnswer(answer,destinationId);
-
- for (int i = 1; answer.size() < Common.BUCKET_SIZE && ((bucket.getId() - i) >= 0 ||
- (bucket.getId() + i) <= Common.IDENTIFIER_SIZE); i++) {
- //Check the previous buckets
- if (bucket.getId() - i >= 0) {
- Bucket bucketP = this.buckets.get(bucket.getId() - i);
- bucketP.addToAnswer(answer,destinationId);
- }
- //Check the next buckets
- if (bucket.getId() + i <= Common.IDENTIFIER_SIZE) {
- Bucket bucketN = this.buckets.get(bucket.getId() + i);
- bucketN.addToAnswer(answer, destinationId);
- }
- }
- //We sort the list
- Collections.sort(answer.getNodes());
- //We trim the list
- answer.trim();
-
- return answer;
- }
-
- @Override
- public String toString() {
- StringBuilder string = new StringBuilder("RoutingTable [ id=" + id + " ");
- for (int i = 0; i < buckets.size(); i++) {
- if (buckets.get(i).size() > 0) {
- string.append(buckets.get(i) + " ");
- }
- }
- return string.toString();
- }
-}