X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0e72b989742d684a4fcc27bb60eaf4b3d2129ac3..417742f1c7f6545db82079acd702fde03547d400:/examples/msg/dht-kademlia/answer.c

diff --git a/examples/msg/dht-kademlia/answer.c b/examples/msg/dht-kademlia/answer.c
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+/* Copyright (c) 2012-2014. 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. */
+
+#include "answer.h"
+
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(msg_kademlia_node);
+
+/** Initialize a node answer object. */
+answer_t answer_init(unsigned int destination_id)
+{
+  answer_t answer = xbt_new(s_answer_t, 1);
+  answer->nodes = xbt_dynar_new(sizeof(node_contact_t), NULL);
+  answer->size = 0;
+  answer->destination_id = destination_id;
+
+  return answer;
+}
+
+/** Destroys a node answer object. */
+void answer_free(answer_t answer)
+{
+  unsigned int i;
+  for (i = 0; i < answer->size; i++) {
+    node_contact_free(*(void **) xbt_dynar_get_ptr(answer->nodes, i));
+  }
+  xbt_dynar_free(&answer->nodes);
+  xbt_free(answer);
+}
+
+/** @brief Prints a answer_t, for debugging purposes */
+void answer_print(answer_t answer)
+{
+  unsigned int cpt;
+  node_contact_t contact;
+  XBT_INFO("Searching %08x, size %d", answer->destination_id, answer->size);
+  xbt_dynar_foreach(answer->nodes, cpt, contact) {
+    XBT_INFO("Node %08x: %08x is at distance %d", cpt, contact->id, contact->distance);
+  }
+}
+
+/** @brief Merge two answer_t together, only keeping the best nodes
+  * @param destination the destination in which the nodes will be put
+  * @param source the source of the nodes to add
+  */
+unsigned int answer_merge(answer_t destination, answer_t source)
+{
+  node_contact_t contact, contact_copy;
+  unsigned int cpt;
+  unsigned int nb_added = 0;
+  /* TODO: Check if same destination */
+  xbt_dynar_foreach(source->nodes, cpt, contact) {
+    if (!answer_contains(destination, contact->id)) {
+      contact_copy = node_contact_copy(contact);
+      xbt_dynar_push(destination->nodes, &contact_copy);
+      destination->size++;
+      nb_added++;
+    }
+  }
+  answer_sort(destination);
+  answer_trim(destination);
+  return nb_added;
+}
+
+/** Helper to sort answer_t objects */
+static int _answer_sort_function(const void *e1, const void *e2)
+{
+  node_contact_t c1 = *(void **) e1;
+  node_contact_t c2 = *(void **) e2;
+  if (c1->distance == c2->distance)
+    return 0;
+  else
+    if (c1->distance < c2->distance)
+      return -1;
+    else
+      return 1;
+}
+
+/** @brief Sorts a answer_t, by node distance.
+  * @param answer the answer to sort
+  * @param destination_id the id of the guy we are trying to find
+  */
+void answer_sort(answer_t answer)
+{
+  xbt_dynar_sort(answer->nodes, &_answer_sort_function);
+}
+
+/** @brief Trims a answer_t, in order for it to have a size of less or equal to "bucket_size"
+  * @param answer the answer_t to trim
+  */
+void answer_trim(answer_t answer)
+{
+  node_contact_t value;
+  while (answer->size > bucket_size) {
+    xbt_dynar_pop(answer->nodes, &value);
+    answer->size--;
+    node_contact_free(value);
+  }
+  xbt_assert(xbt_dynar_length(answer->nodes) == answer->size, "Wrong size for the answer");
+}
+
+/** @brief Adds the content of a bucket unsigned into a answer object.
+  * @param bucket the bucket we have to had unsigned into
+  * @param answer the answer object we're going  to put the data in
+  * @param destination_id the id of the guy we are trying to find.
+  */
+void answer_add_bucket(bucket_t bucket, answer_t answer)
+{
+  unsigned int cpt;
+  unsigned int id, distance;
+  node_contact_t contact;
+  xbt_assert((bucket != NULL), "Provided a NULL bucket");
+  xbt_assert((bucket->nodes != NULL), "Provided a bucket which nodes are NULL");
+  xbt_dynar_foreach(bucket->nodes, cpt, id) {
+    distance = id ^ answer->destination_id;
+    contact = node_contact_new(id, distance);
+    xbt_dynar_push(answer->nodes, &contact);
+    answer->size++;
+  }
+}
+
+/** @brief Returns if the id supplied is in the answer.
+  * @param id : id we're looking for
+  */
+unsigned int answer_contains(answer_t answer, unsigned int id)
+{
+  unsigned int i = 0;
+  node_contact_t contact;
+  xbt_dynar_foreach(answer->nodes, i, contact){
+    if (id == contact->id) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/** @brief Returns if the destination we are trying to find is found
+  * @param answer the answer
+  * @return if the destination is found.
+  */
+unsigned int answer_destination_found(answer_t answer)
+{
+  if (xbt_dynar_length(answer->nodes) < 1) {
+    return 0;
+  }
+  node_contact_t contact_tail = xbt_dynar_get_as(answer->nodes, 0, node_contact_t);
+  return contact_tail->distance == 0;
+}