X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0746edb369906f57c331d9336bf85ae91094ad51..0bfafcab47ae9cd7856bd8d129404c33079d6afe:/examples/s4u/dht-kademlia/node.cpp

diff --git a/examples/s4u/dht-kademlia/node.cpp b/examples/s4u/dht-kademlia/node.cpp
deleted file mode 100644
index 8ffc0c15e7..0000000000
--- a/examples/s4u/dht-kademlia/node.cpp
+++ /dev/null
@@ -1,308 +0,0 @@
-/* Copyright (c) 2010-2021. 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 "node.hpp"
-#include "routing_table.hpp"
-
-XBT_LOG_NEW_DEFAULT_CATEGORY(kademlia_node, "Messages specific for this example");
-
-namespace kademlia {
-static void destroy(void* message)
-{
-  const auto* msg = static_cast<Message*>(message);
-  delete msg;
-}
-
-/**
-  * @brief Tries to join the network
-  * @param known_id id of the node I know in the network.
-  */
-bool Node::join(unsigned int known_id)
-{
-  bool got_answer = false;
-
-  /* Add the guy we know to our routing table and ourselves. */
-  routingTableUpdate(id_);
-  routingTableUpdate(known_id);
-
-  /* First step: Send a "FIND_NODE" request to the node we know */
-  sendFindNode(known_id, id_);
-
-  simgrid::s4u::Mailbox* mailbox = simgrid::s4u::Mailbox::by_name(std::to_string(id_));
-  do {
-    if (receive_comm == nullptr)
-      receive_comm = mailbox->get_async<Message>(&received_msg);
-    if (receive_comm->test()) {
-      XBT_DEBUG("Received an answer from the node I know.");
-      got_answer = true;
-      // retrieve the node list and ping them.
-      const Answer* node_list = received_msg->answer_.get();
-      if (node_list) {
-        for (auto const& contact : node_list->getNodes())
-          routingTableUpdate(contact.first);
-      } else {
-        handleFindNode(received_msg);
-      }
-      delete received_msg;
-      receive_comm = nullptr;
-    } else
-      simgrid::s4u::this_actor::sleep_for(1);
-  } while (not got_answer);
-
-  /* Second step: Send a FIND_NODE to a random node in buckets */
-  unsigned int bucket_id = table.findBucket(known_id)->getId();
-  xbt_assert(bucket_id <= IDENTIFIER_SIZE);
-  for (unsigned int i = 0; ((bucket_id > i) || (bucket_id + i) <= IDENTIFIER_SIZE) && i < JOIN_BUCKETS_QUERIES; i++) {
-    if (bucket_id > i) {
-      unsigned int id_in_bucket = get_id_in_prefix(id_, bucket_id - i);
-      findNode(id_in_bucket, false);
-    }
-    if (bucket_id + i <= IDENTIFIER_SIZE) {
-      unsigned int id_in_bucket = get_id_in_prefix(id_, bucket_id + i);
-      findNode(id_in_bucket, false);
-    }
-  }
-  return got_answer;
-}
-
-/** @brief Send a "FIND_NODE" to a node
-  * @param id node we are querying
-  * @param destination node we are trying to find.
-  */
-void Node::sendFindNode(unsigned int id, unsigned int destination) const
-{
-  /* Gets the mailbox to send to */
-  simgrid::s4u::Mailbox* mailbox = simgrid::s4u::Mailbox::by_name(std::to_string(id));
-  /* Build the task */
-
-  auto* msg = new Message(id_, destination, simgrid::s4u::Mailbox::by_name(std::to_string(id_)),
-                          simgrid::s4u::Host::current()->get_cname());
-
-  /* Send the task */
-  mailbox->put_init(msg, 1)->detach(kademlia::destroy);
-  XBT_VERB("Asking %u for its closest nodes", id);
-}
-
-/**
-  * Sends to the best "KADEMLIA_ALPHA" nodes in the "node_list" array a "FIND_NODE" request, to ask them for their best
-  * nodes
-  */
-unsigned int Node::sendFindNodeToBest(const Answer* node_list) const
-{
-  unsigned int i           = 0;
-  unsigned int j           = 0;
-  unsigned int destination = node_list->getDestinationId();
-  for (auto const& node_to_query : node_list->getNodes()) {
-    /* We need to have at most "KADEMLIA_ALPHA" requests each time, according to the protocol */
-    /* Gets the node we want to send the query to */
-    if (node_to_query.first != id_) { /* No need to query ourselves */
-      sendFindNode(node_to_query.first, destination);
-      j++;
-    }
-    i++;
-    if (j == KADEMLIA_ALPHA)
-      break;
-  }
-  return i;
-}
-
-/** @brief Updates/Puts the node id unsigned into our routing table
-  * @param id The id of the node we need to add unsigned into our routing table
-  */
-void Node::routingTableUpdate(unsigned int id)
-{
-  // retrieval of the bucket in which the should be
-  Bucket* bucket = table.findBucket(id);
-
-  // check if the id is already in the bucket.
-  auto id_pos = std::find(bucket->nodes_.begin(), bucket->nodes_.end(), id);
-
-  if (id_pos == bucket->nodes_.end()) {
-    /* We check if the bucket is full or not. If it is, we evict an old element */
-    if (bucket->nodes_.size() >= BUCKET_SIZE) {
-      bucket->nodes_.pop_back();
-    }
-    bucket->nodes_.push_front(id);
-    XBT_VERB("I'm adding to my routing table %08x", id);
-  } else {
-    // We push the element to the front
-    bucket->nodes_.erase(id_pos);
-    bucket->nodes_.push_front(id);
-    XBT_VERB("I'm updating %08x", id);
-  }
-}
-
-/** @brief Finds the closest nodes to the node given.
-  * @param node : our node
-  * @param destination_id : the id of the guy we are trying to find
-  */
-std::unique_ptr<Answer> Node::findClosest(unsigned int destination_id)
-{
-  auto answer = std::make_unique<Answer>(destination_id);
-  /* We find the corresponding bucket for the id */
-  const Bucket* bucket = table.findBucket(destination_id);
-  int bucket_id  = bucket->getId();
-  xbt_assert((bucket_id <= IDENTIFIER_SIZE), "Bucket found has a wrong identifier");
-  /* So, we copy the contents of the bucket unsigned into our answer */
-  answer->addBucket(bucket);
-
-  /* However, if we don't have enough elements in our bucket, we NEED to include at least "BUCKET_SIZE" elements
-   * (if, of course, we know at least "BUCKET_SIZE" elements. So we're going to look unsigned into the other buckets.
-   */
-  for (int i = 1; answer->getSize() < BUCKET_SIZE && ((bucket_id - i > 0) || (bucket_id + i < IDENTIFIER_SIZE)); i++) {
-    /* We check the previous buckets */
-    if (bucket_id - i >= 0) {
-      const Bucket* bucket_p = &table.getBucketAt(bucket_id - i);
-      answer->addBucket(bucket_p);
-    }
-    /* We check the next buckets */
-    if (bucket_id + i <= IDENTIFIER_SIZE) {
-      const Bucket* bucket_n = &table.getBucketAt(bucket_id + i);
-      answer->addBucket(bucket_n);
-    }
-  }
-  /* We trim the array to have only BUCKET_SIZE or less elements */
-  answer->trim();
-
-  return answer;
-}
-
-/** @brief Send a request to find a node in the node routing table.
-  * @param id_to_find the id of the node we are trying to find
-  */
-bool Node::findNode(unsigned int id_to_find, bool count_in_stats)
-{
-  unsigned int queries;
-  unsigned int answers;
-  bool destination_found   = false;
-  unsigned int nodes_added = 0;
-  double global_timeout    = simgrid::s4u::Engine::get_clock() + FIND_NODE_GLOBAL_TIMEOUT;
-  unsigned int steps       = 0;
-
-  /* First we build a list of who we already know */
-  std::unique_ptr<Answer> node_list = findClosest(id_to_find);
-  xbt_assert((node_list != nullptr), "node_list incorrect");
-  XBT_DEBUG("Doing a FIND_NODE on %08x", id_to_find);
-
-  /* Ask the nodes on our list if they have information about the node we are trying to find */
-  do {
-    answers        = 0;
-    queries        = sendFindNodeToBest(node_list.get());
-    nodes_added    = 0;
-    double timeout = simgrid::s4u::Engine::get_clock() + FIND_NODE_TIMEOUT;
-    steps++;
-    double time_beginreceive = simgrid::s4u::Engine::get_clock();
-
-    simgrid::s4u::Mailbox* mailbox = simgrid::s4u::Mailbox::by_name(std::to_string(id_));
-    do {
-      if (receive_comm == nullptr)
-        receive_comm = mailbox->get_async<Message>(&received_msg);
-
-      if (receive_comm->test()) {
-        // Check if what we have received is what we are looking for.
-        if (received_msg->answer_ && received_msg->answer_->getDestinationId() == id_to_find) {
-          routingTableUpdate(received_msg->sender_id_);
-          // Handle the answer
-          for (auto const& contact : node_list->getNodes())
-            routingTableUpdate(contact.first);
-          answers++;
-
-          nodes_added = node_list->merge(received_msg->answer_.get());
-          XBT_DEBUG("Received an answer from %s (%s) with %zu nodes on it", received_msg->answer_to_->get_cname(),
-                    received_msg->issuer_host_name_.c_str(), received_msg->answer_->getSize());
-        } else {
-          if (received_msg->answer_) {
-            routingTableUpdate(received_msg->sender_id_);
-            XBT_DEBUG("Received a wrong answer for a FIND_NODE");
-          } else {
-            handleFindNode(received_msg);
-          }
-          // Update the timeout if we didn't have our answer
-          timeout += simgrid::s4u::Engine::get_clock() - time_beginreceive;
-          time_beginreceive = simgrid::s4u::Engine::get_clock();
-        }
-        delete received_msg;
-        receive_comm = nullptr;
-      } else {
-        simgrid::s4u::this_actor::sleep_for(1);
-      }
-    } while (simgrid::s4u::Engine::get_clock() < timeout && answers < queries);
-    destination_found = node_list->destinationFound();
-  } while (not destination_found && (nodes_added > 0 || answers == 0) &&
-           simgrid::s4u::Engine::get_clock() < global_timeout && steps < MAX_STEPS);
-
-  if (destination_found) {
-    if (count_in_stats)
-      find_node_success++;
-    if (queries > 4)
-      XBT_VERB("FIND_NODE on %08x success in %u steps", id_to_find, steps);
-    routingTableUpdate(id_to_find);
-  } else {
-    if (count_in_stats) {
-      find_node_failed++;
-      XBT_VERB("%08x not found in %u steps", id_to_find, steps);
-    }
-  }
-  return destination_found;
-}
-
-/** @brief Does a pseudo-random lookup for someone in the system
-  * @param node caller node data
-  */
-void Node::randomLookup()
-{
-  unsigned int id_to_look = RANDOM_LOOKUP_NODE; // Totally random.
-  /* TODO: Use some pseudo-random generator. */
-  XBT_DEBUG("I'm doing a random lookup");
-  findNode(id_to_look, true);
-}
-
-/** @brief Handles the answer to an incoming "find_node" task */
-void Node::handleFindNode(const Message* msg)
-{
-  routingTableUpdate(msg->sender_id_);
-  XBT_VERB("Received a FIND_NODE from %s (%s), he's trying to find %08x", msg->answer_to_->get_cname(),
-           msg->issuer_host_name_.c_str(), msg->destination_id_);
-  // Building the answer to the request
-  auto* answer =
-      new Message(id_, msg->destination_id_, findClosest(msg->destination_id_),
-                  simgrid::s4u::Mailbox::by_name(std::to_string(id_)), simgrid::s4u::Host::current()->get_cname());
-  // Sending the answer
-  msg->answer_to_->put_init(answer, 1)->detach(kademlia::destroy);
-}
-
-void Node::displaySuccessRate() const
-{
-  XBT_INFO("%u/%u FIND_NODE have succeeded", find_node_success, find_node_success + find_node_failed);
-}
-} // namespace kademlia
-/**@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
- */
-unsigned int get_id_in_prefix(unsigned int id, unsigned int prefix)
-{
-  if (prefix == 0) {
-    return 0;
-  } else {
-    return (1U << (prefix - 1)) ^ id;
-  }
-}
-
-/** @brief Returns the prefix of an identifier.
-  * The prefix is the id of the bucket in which the remote identifier xor our identifier should be stored.
-  * @param id : big unsigned int id to test
-  * @param nb_bits : key size
-  */
-unsigned int get_node_prefix(unsigned int id, unsigned int nb_bits)
-{
-  unsigned int size = sizeof(unsigned int) * 8;
-  for (unsigned int j = 0; j < size; j++) {
-    if (((id >> (size - 1 - j)) & 0x1) != 0) {
-      return nb_bits - (j);
-    }
-  }
-  return 0;
-}