2 /* Copyright (c) 2010, 2012. The SimGrid Team.
3 * All rights reserved. */
5 /* This program is free software; you can redistribute it and/or modify it
6 * under the terms of the license (GNU LGPL) which comes with this package. */
9 #include "routing_table.h"
13 #include "xbt/asserts.h"
14 XBT_LOG_NEW_DEFAULT_CATEGORY(msg_kademlia_node,
15 "Messages specific for this msg example");
17 * \brief Initialization of a node
18 * \param node_id the id of the node
19 * \return the node created
21 node_t node_init(unsigned int node_id)
23 node_t node = xbt_new(s_node_t, 1);
26 node->table = routing_table_init(node_id);
27 sprintf(node->mailbox, "%0*x", MAILBOX_NAME_SIZE, node_id);
28 node->find_node_failed = 0;
29 node->find_node_success = 0;
31 node->task_received = NULL;
32 node->receive_comm = NULL;
38 * \brief Node destructor
40 void node_free(node_t node)
42 routing_table_free(node->table);
47 * @brief Updates/Puts the node id unsigned into our routing table
48 * @param node Our node data
49 * @param id The id of the node we need to add unsigned into our routing table
51 void node_routing_table_update(node_t node, unsigned int id)
53 routing_table_t table = node->table;
54 //retrieval of the bucket in which the should be
55 bucket_t bucket = routing_table_find_bucket(table, id);
57 //check if the id is already in the bucket.
58 unsigned int id_pos = bucket_find_id(bucket, id);
61 /* We check if the bucket is full or not. If it is, we evict
62 * old offline elements */
63 if (xbt_dynar_length(bucket->nodes) < bucket_size) {
64 //TODO: this is not really very efficient. Maybe we should use something else than dynars ?
65 xbt_dynar_unshift(bucket->nodes, &id);
66 XBT_VERB("I'm adding to my routing table %08x", id);
68 /* 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. */
71 //We push to the front of the dynar the element.
72 unsigned int element =
73 xbt_dynar_get_as(bucket->nodes, id_pos, unsigned int);
74 xbt_dynar_remove_at(bucket->nodes, id_pos, NULL);
75 xbt_dynar_unshift(bucket->nodes, &element);
76 XBT_VERB("I'm updating %08x", element);
81 * Finds the closest nodes to the node given.
82 * @param node : our node
83 * @param destination_id : the id of the guy we are trying to find
85 answer_t node_find_closest(node_t node, unsigned int destination_id)
88 answer_t answer = answer_init(destination_id);
89 /* We find the corresponding bucket for the id */
90 bucket_t bucket = routing_table_find_bucket(node->table, destination_id);
91 int bucket_id = bucket->id;
92 xbt_assert((bucket_id <= identifier_size),
93 "Bucket found has a wrong identifier");
94 /* So, we copy the contents of the bucket unsigned into our result dynar */
95 answer_add_bucket(bucket, answer);
97 /* However, if we don't have enough elements in our bucket, we NEED to
99 * "bucket_size" elements (if, of course, we know at least "bucket_size" elements. So we're going to look unsigned into the other buckets.
102 answer->size < bucket_size && ((bucket_id - i > 0)
103 || (bucket_id + i < identifier_size));
105 /* We check the previous buckets */
106 if (bucket_id - i >= 0) {
107 bucket_t bucket_p = &node->table->buckets[bucket_id - i];
108 answer_add_bucket(bucket_p, answer);
110 /* We check the next buckets */
111 if (bucket_id + i <= identifier_size) {
112 bucket_t bucket_n = &node->table->buckets[bucket_id + i];
113 answer_add_bucket(bucket_n, answer);
116 /* We sort the array by XOR distance */
118 /* We trim the array to have only bucket_size or less elements */
125 * Returns an identifier which is in a specific bucket of a routing table
126 * @brief id id of the routing table owner
127 * @brief prefix id of the bucket where we want that identifier to be
129 unsigned int get_id_in_prefix(unsigned int id, unsigned int prefix)
134 unsigned int n = 1 << (prefix - 1);
139 * \brief Returns the prefix of an identifier.
140 * The prefix is the id of the bucket in which the remote identifier xor our identifier should be stored.
141 * @param id : bigunsigned int id to test
142 * @param nb_bits : key size
144 unsigned int get_node_prefix(unsigned int id, unsigned int nb_bits)
146 unsigned int j, size = sizeof(unsigned int) * 8;
147 for (j = 0; j < size; j++) {
148 if (((id >> (size - 1 - j)) & 0x1) != 0) {
149 return nb_bits - (j);
156 * \brief Gets the mailbox name of a host given its identifier
158 void get_node_mailbox(unsigned int id, char *mailbox)
160 sprintf(mailbox, "%0*x", MAILBOX_NAME_SIZE, id);
164 * Constructor, build a new contact information.
166 node_contact_t node_contact_new(unsigned int id, unsigned int distance)
168 node_contact_t contact = xbt_new(s_node_contact_t, 1);
171 contact->distance = distance;
177 * Builds a contact information from a contact information
179 node_contact_t node_contact_copy(node_contact_t node_contact)
181 node_contact_t contact = xbt_new(s_node_contact_t, 1);
183 contact->id = node_contact->id;
184 contact->distance = node_contact->distance;
191 * @param contact the node_contact to kill.
193 void node_contact_free(node_contact_t contact)