1 /* Copyright (c) 2010, 2012-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
8 #include "routing_table.h"
12 #include "xbt/asserts.h"
13 XBT_LOG_NEW_DEFAULT_CATEGORY(msg_kademlia_node,
14 "Messages specific for this msg example");
16 * \brief Initialization of a node
17 * \param node_id the id of the node
18 * \return the node created
20 node_t node_init(unsigned int node_id)
22 node_t node = xbt_new(s_node_t, 1);
25 node->table = routing_table_init(node_id);
26 sprintf(node->mailbox, "%0*x", MAILBOX_NAME_SIZE, node_id);
27 node->find_node_failed = 0;
28 node->find_node_success = 0;
30 node->task_received = NULL;
31 node->receive_comm = NULL;
37 * \brief Node destructor
39 void node_free(node_t node)
41 routing_table_free(node->table);
46 * @brief Updates/Puts the node id unsigned into our routing table
47 * @param node Our node data
48 * @param id The id of the node we need to add unsigned into our routing table
50 void node_routing_table_update(node_t node, unsigned int id)
52 routing_table_t table = node->table;
53 //retrieval of the bucket in which the should be
54 bucket_t bucket = routing_table_find_bucket(table, id);
56 //check if the id is already in the bucket.
57 unsigned int id_pos = bucket_find_id(bucket, id);
60 /* We check if the bucket is full or not. If it is, we evict
61 * old offline elements */
62 if (xbt_dynar_length(bucket->nodes) < bucket_size) {
63 //TODO: this is not really very efficient. Maybe we should use something else than dynars ?
64 xbt_dynar_unshift(bucket->nodes, &id);
65 XBT_VERB("I'm adding to my routing table %08x", id);
67 /* TODO: we need to evict the old elements: that's why this function is in "node" instead of "routing table". This is not implemented yet. */
70 //We push to the front of the dynar the element.
71 unsigned int element =
72 xbt_dynar_get_as(bucket->nodes, id_pos, unsigned int);
73 xbt_dynar_remove_at(bucket->nodes, id_pos, NULL);
74 xbt_dynar_unshift(bucket->nodes, &element);
75 XBT_VERB("I'm updating %08x", element);
80 * Finds the closest nodes to the node given.
81 * @param node : our node
82 * @param destination_id : the id of the guy we are trying to find
84 answer_t node_find_closest(node_t node, unsigned int destination_id)
87 answer_t answer = answer_init(destination_id);
88 /* We find the corresponding bucket for the id */
89 bucket_t bucket = routing_table_find_bucket(node->table, destination_id);
90 int bucket_id = bucket->id;
91 xbt_assert((bucket_id <= identifier_size),
92 "Bucket found has a wrong identifier");
93 /* So, we copy the contents of the bucket unsigned into our result dynar */
94 answer_add_bucket(bucket, answer);
96 /* However, if we don't have enough elements in our bucket, we NEED to
98 * "bucket_size" elements (if, of course, we know at least "bucket_size" elements. So we're going to look unsigned into the other buckets.
101 answer->size < bucket_size && ((bucket_id - i > 0)
102 || (bucket_id + i < identifier_size));
104 /* We check the previous buckets */
105 if (bucket_id - i >= 0) {
106 bucket_t bucket_p = &node->table->buckets[bucket_id - i];
107 answer_add_bucket(bucket_p, answer);
109 /* We check the next buckets */
110 if (bucket_id + i <= identifier_size) {
111 bucket_t bucket_n = &node->table->buckets[bucket_id + i];
112 answer_add_bucket(bucket_n, answer);
115 /* We sort the array by XOR distance */
117 /* We trim the array to have only bucket_size or less elements */
124 * Returns an identifier which is in a specific bucket of a routing table
125 * @brief id id of the routing table owner
126 * @brief prefix id of the bucket where we want that identifier to be
128 unsigned int get_id_in_prefix(unsigned int id, unsigned int prefix)
133 unsigned int n = 1 << (prefix - 1);
138 * \brief Returns the prefix of an identifier.
139 * The prefix is the id of the bucket in which the remote identifier xor our identifier should be stored.
140 * @param id : bigunsigned int id to test
141 * @param nb_bits : key size
143 unsigned int get_node_prefix(unsigned int id, unsigned int nb_bits)
145 unsigned int j, size = sizeof(unsigned int) * 8;
146 for (j = 0; j < size; j++) {
147 if (((id >> (size - 1 - j)) & 0x1) != 0) {
148 return nb_bits - (j);
155 * \brief Gets the mailbox name of a host given its identifier
157 void get_node_mailbox(unsigned int id, char *mailbox)
159 sprintf(mailbox, "%0*x", MAILBOX_NAME_SIZE, id);
163 * Constructor, build a new contact information.
165 node_contact_t node_contact_new(unsigned int id, unsigned int distance)
167 node_contact_t contact = xbt_new(s_node_contact_t, 1);
170 contact->distance = distance;
176 * Builds a contact information from a contact information
178 node_contact_t node_contact_copy(node_contact_t node_contact)
180 node_contact_t contact = xbt_new(s_node_contact_t, 1);
182 contact->id = node_contact->id;
183 contact->distance = node_contact->distance;
190 * @param contact the node_contact to kill.
192 void node_contact_free(node_contact_t contact)