-/* Copyright (c) 2012-2020. 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 <algorithm>
-#include <climits>
-
-#include "s4u-peer.hpp"
-#include "s4u-tracker.hpp"
-
-XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_bt_peer, "Messages specific for the peers");
-
-/*
- * User parameters for transferred file data. For the test, the default values are :
- * File size: 10 pieces * 5 blocks/piece * 16384 bytes/block = 819200 bytes
- */
-constexpr unsigned long FILE_PIECES = 10UL;
-constexpr unsigned long PIECES_BLOCKS = 5UL;
-constexpr int BLOCK_SIZE = 16384;
-
-/** Number of blocks asked by each request */
-constexpr unsigned long BLOCKS_REQUESTED = 2UL;
-
-constexpr double SLEEP_DURATION = 1.0;
-#define BITS_TO_BYTES(x) (((x) / 8 + (x) % 8) ? 1 : 0)
-
-Peer::Peer(std::vector<std::string> args)
-{
- // Check arguments
- xbt_assert(args.size() == 3 || args.size() == 4, "Wrong number of arguments");
- try {
- id = std::stoi(args[1]);
- mailbox_ = simgrid::s4u::Mailbox::by_name(std::to_string(id));
- } catch (const std::invalid_argument&) {
- throw std::invalid_argument("Invalid ID:" + args[1]);
- }
- random.set_seed(id);
-
- try {
- deadline = std::stod(args[2]);
- } catch (const std::invalid_argument&) {
- throw std::invalid_argument("Invalid deadline:" + args[2]);
- }
- xbt_assert(deadline > 0, "Wrong deadline supplied");
-
- if (args.size() == 4 && args[3] == "1") {
- bitfield_ = (1U << FILE_PIECES) - 1U;
- bitfield_blocks = (1ULL << (FILE_PIECES * PIECES_BLOCKS)) - 1ULL;
- }
- pieces_count.resize(FILE_PIECES);
-
- XBT_INFO("Hi, I'm joining the network with id %d", id);
-}
-
-/** Peer main function */
-void Peer::operator()()
-{
- // Getting peer data from the tracker.
- if (getPeersFromTracker()) {
- XBT_DEBUG("Got %zu peers from the tracker. Current status is: %s", connected_peers.size(), getStatus().c_str());
- begin_receive_time = simgrid::s4u::Engine::get_clock();
- mailbox_->set_receiver(simgrid::s4u::Actor::self());
- if (hasFinished()) {
- sendHandshakeToAllPeers();
- } else {
- leech();
- }
- seed();
- } else {
- XBT_INFO("Couldn't contact the tracker.");
- }
-
- XBT_INFO("Here is my current status: %s", getStatus().c_str());
-}
-
-bool Peer::getPeersFromTracker()
-{
- simgrid::s4u::Mailbox* tracker_mailbox = simgrid::s4u::Mailbox::by_name(TRACKER_MAILBOX);
- // Build the task to send to the tracker
- TrackerQuery* peer_request = new TrackerQuery(id, mailbox_);
- try {
- XBT_DEBUG("Sending a peer request to the tracker.");
- tracker_mailbox->put(peer_request, TRACKER_COMM_SIZE, GET_PEERS_TIMEOUT);
- } catch (const simgrid::TimeoutException&) {
- XBT_DEBUG("Timeout expired when requesting peers to tracker");
- delete peer_request;
- return false;
- }
-
- try {
- TrackerAnswer* answer = static_cast<TrackerAnswer*>(mailbox_->get(GET_PEERS_TIMEOUT));
- // Add the peers the tracker gave us to our peer list.
- for (auto const& peer_id : answer->getPeers())
- if (id != peer_id)
- connected_peers.emplace(peer_id, Connection(peer_id));
- delete answer;
- } catch (const simgrid::TimeoutException&) {
- XBT_DEBUG("Timeout expired when requesting peers to tracker");
- return false;
- }
- return true;
-}
-
-void Peer::sendHandshakeToAllPeers()
-{
- for (auto const& kv : connected_peers) {
- const Connection& remote_peer = kv.second;
- Message* handshake = new Message(MESSAGE_HANDSHAKE, id, mailbox_);
- remote_peer.mailbox_->put_init(handshake, MESSAGE_HANDSHAKE_SIZE)->detach();
- XBT_DEBUG("Sending a HANDSHAKE to %d", remote_peer.id);
- }
-}
-
-void Peer::sendMessage(simgrid::s4u::Mailbox* mailbox, e_message_type type, uint64_t size)
-{
- const char* type_names[6] = {"HANDSHAKE", "CHOKE", "UNCHOKE", "INTERESTED", "NOTINTERESTED", "CANCEL"};
- XBT_DEBUG("Sending %s to %s", type_names[type], mailbox->get_cname());
- mailbox->put_init(new Message(type, id, bitfield_, mailbox_), size)->detach();
-}
-
-void Peer::sendBitfield(simgrid::s4u::Mailbox* mailbox)
-{
- XBT_DEBUG("Sending a BITFIELD to %s", mailbox->get_cname());
- mailbox
- ->put_init(new Message(MESSAGE_BITFIELD, id, bitfield_, mailbox_),
- MESSAGE_BITFIELD_SIZE + BITS_TO_BYTES(FILE_PIECES))
- ->detach();
-}
-
-void Peer::sendPiece(simgrid::s4u::Mailbox* mailbox, unsigned int piece, int block_index, int block_length)
-{
- xbt_assert(not hasNotPiece(piece), "Tried to send a unavailable piece.");
- XBT_DEBUG("Sending the PIECE %u (%d,%d) to %s", piece, block_index, block_length, mailbox->get_cname());
- mailbox->put_init(new Message(MESSAGE_PIECE, id, mailbox_, piece, block_index, block_length), BLOCK_SIZE)->detach();
-}
-
-void Peer::sendHaveToAllPeers(unsigned int piece)
-{
- XBT_DEBUG("Sending HAVE message to all my peers");
- for (auto const& kv : connected_peers) {
- const Connection& remote_peer = kv.second;
- remote_peer.mailbox_->put_init(new Message(MESSAGE_HAVE, id, mailbox_, piece), MESSAGE_HAVE_SIZE)->detach();
- }
-}
-
-void Peer::sendRequestTo(Connection* remote_peer, unsigned int piece)
-{
- remote_peer->current_piece = piece;
- xbt_assert(remote_peer->hasPiece(piece));
- int block_index = getFirstMissingBlockFrom(piece);
- if (block_index != -1) {
- int block_length = std::min(BLOCKS_REQUESTED, PIECES_BLOCKS - block_index);
- XBT_DEBUG("Sending a REQUEST to %s for piece %u (%d,%d)", remote_peer->mailbox_->get_cname(), piece, block_index,
- block_length);
- remote_peer->mailbox_
- ->put_init(new Message(MESSAGE_REQUEST, id, mailbox_, piece, block_index, block_length), MESSAGE_REQUEST_SIZE)
- ->detach();
- }
-}
-
-std::string Peer::getStatus() const
-{
- std::string res;
- for (unsigned i = 0; i < FILE_PIECES; i++)
- res += (bitfield_ & (1U << i)) ? '1' : '0';
- return res;
-}
-
-bool Peer::hasFinished() const
-{
- return bitfield_ == (1U << FILE_PIECES) - 1U;
-}
-
-/** Indicates if the remote peer has a piece not stored by the local peer */
-bool Peer::isInterestedBy(const Connection* remote_peer) const
-{
- return remote_peer->bitfield & (bitfield_ ^ ((1 << FILE_PIECES) - 1));
-}
-
-bool Peer::isInterestedByFree(const Connection* remote_peer) const
-{
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (hasNotPiece(i) && remote_peer->hasPiece(i) && isNotDownloadingPiece(i))
- return true;
- return false;
-}
-
-void Peer::updatePiecesCountFromBitfield(unsigned int bitfield)
-{
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (bitfield & (1U << i))
- pieces_count[i]++;
-}
-
-unsigned int Peer::countPieces(unsigned int bitfield) const
-{
- unsigned int count = 0U;
- unsigned int n = bitfield;
- while (n) {
- count += n & 1U;
- n >>= 1U;
- }
- return count;
-}
-
-int Peer::nbInterestedPeers() const
-{
- int nb = 0;
- for (auto const& kv : connected_peers)
- if (kv.second.interested)
- nb++;
- return nb;
-}
-
-void Peer::leech()
-{
- double next_choked_update = simgrid::s4u::Engine::get_clock() + UPDATE_CHOKED_INTERVAL;
- XBT_DEBUG("Start downloading.");
-
- /* Send a "handshake" message to all the peers it got (since it couldn't have gotten more than 50 peers) */
- sendHandshakeToAllPeers();
- XBT_DEBUG("Starting main leech loop listening on mailbox: %s", mailbox_->get_cname());
-
- void* data = nullptr;
- while (simgrid::s4u::Engine::get_clock() < deadline && countPieces(bitfield_) < FILE_PIECES) {
- if (comm_received == nullptr) {
- comm_received = mailbox_->get_async(&data);
- }
- if (comm_received->test()) {
- message = static_cast<Message*>(data);
- handleMessage();
- delete message;
- comm_received = nullptr;
- } else {
- // We don't execute the choke algorithm if we don't already have a piece
- if (simgrid::s4u::Engine::get_clock() >= next_choked_update && countPieces(bitfield_) > 0) {
- updateChokedPeers();
- next_choked_update += UPDATE_CHOKED_INTERVAL;
- } else {
- simgrid::s4u::this_actor::sleep_for(SLEEP_DURATION);
- }
- }
- }
- if (hasFinished())
- XBT_DEBUG("%d becomes a seeder", id);
-}
-
-void Peer::seed()
-{
- double next_choked_update = simgrid::s4u::Engine::get_clock() + UPDATE_CHOKED_INTERVAL;
- XBT_DEBUG("Start seeding.");
- // start the main seed loop
- void* data = nullptr;
- while (simgrid::s4u::Engine::get_clock() < deadline) {
- if (comm_received == nullptr) {
- comm_received = mailbox_->get_async(&data);
- }
- if (comm_received->test()) {
- message = static_cast<Message*>(data);
- handleMessage();
- delete message;
- comm_received = nullptr;
- } else {
- if (simgrid::s4u::Engine::get_clock() >= next_choked_update) {
- updateChokedPeers();
- // TODO: Change the choked peer algorithm when seeding.
- next_choked_update += UPDATE_CHOKED_INTERVAL;
- } else {
- simgrid::s4u::this_actor::sleep_for(SLEEP_DURATION);
- }
- }
- }
-}
-
-void Peer::updateActivePeersSet(Connection* remote_peer)
-{
- if (remote_peer->interested && not remote_peer->choked_upload)
- active_peers.insert(remote_peer);
- else
- active_peers.erase(remote_peer);
-}
-
-void Peer::handleMessage()
-{
- const char* type_names[10] = {"HANDSHAKE", "CHOKE", "UNCHOKE", "INTERESTED", "NOTINTERESTED",
- "HAVE", "BITFIELD", "REQUEST", "PIECE", "CANCEL"};
-
- XBT_DEBUG("Received a %s message from %s", type_names[message->type], message->return_mailbox->get_cname());
-
- auto known_peer = connected_peers.find(message->peer_id);
- Connection* remote_peer = (known_peer == connected_peers.end()) ? nullptr : &known_peer->second;
- xbt_assert(remote_peer != nullptr || message->type == MESSAGE_HANDSHAKE,
- "The impossible did happened: A not-in-our-list peer sent us a message.");
-
- switch (message->type) {
- case MESSAGE_HANDSHAKE:
- // Check if the peer is in our connection list.
- if (remote_peer == nullptr) {
- XBT_DEBUG("This peer %d was unknown, answer to its handshake", message->peer_id);
- connected_peers.emplace(message->peer_id, Connection(message->peer_id));
- sendMessage(message->return_mailbox, MESSAGE_HANDSHAKE, MESSAGE_HANDSHAKE_SIZE);
- }
- // Send our bitfield to the peer
- sendBitfield(message->return_mailbox);
- break;
- case MESSAGE_BITFIELD:
- // Update the pieces list
- updatePiecesCountFromBitfield(message->bitfield);
- // Store the bitfield
- remote_peer->bitfield = message->bitfield;
- xbt_assert(not remote_peer->am_interested, "Should not be interested at first");
- if (isInterestedBy(remote_peer)) {
- remote_peer->am_interested = true;
- sendMessage(message->return_mailbox, MESSAGE_INTERESTED, MESSAGE_INTERESTED_SIZE);
- }
- break;
- case MESSAGE_INTERESTED:
- // Update the interested state of the peer.
- remote_peer->interested = true;
- updateActivePeersSet(remote_peer);
- break;
- case MESSAGE_NOTINTERESTED:
- remote_peer->interested = false;
- updateActivePeersSet(remote_peer);
- break;
- case MESSAGE_UNCHOKE:
- xbt_assert(remote_peer->choked_download);
- remote_peer->choked_download = false;
- // Send requests to the peer, since it has unchoked us
- if (remote_peer->am_interested)
- requestNewPieceTo(remote_peer);
- break;
- case MESSAGE_CHOKE:
- xbt_assert(not remote_peer->choked_download);
- remote_peer->choked_download = true;
- if (remote_peer->current_piece != -1)
- removeCurrentPiece(remote_peer, remote_peer->current_piece);
- break;
- case MESSAGE_HAVE:
- XBT_DEBUG("\t for piece %d", message->piece);
- xbt_assert((message->piece >= 0 && static_cast<unsigned int>(message->piece) < FILE_PIECES),
- "Wrong HAVE message received");
- remote_peer->bitfield = remote_peer->bitfield | (1U << static_cast<unsigned int>(message->piece));
- pieces_count[message->piece]++;
- // If the piece is in our pieces, we tell the peer that we are interested.
- if (not remote_peer->am_interested && hasNotPiece(message->piece)) {
- remote_peer->am_interested = true;
- sendMessage(message->return_mailbox, MESSAGE_INTERESTED, MESSAGE_INTERESTED_SIZE);
- if (not remote_peer->choked_download)
- requestNewPieceTo(remote_peer);
- }
- break;
- case MESSAGE_REQUEST:
- xbt_assert(remote_peer->interested);
- xbt_assert((message->piece >= 0 && static_cast<unsigned int>(message->piece) < FILE_PIECES),
- "Wrong HAVE message received");
- if (not remote_peer->choked_upload) {
- XBT_DEBUG("\t for piece %d (%d,%d)", message->piece, message->block_index,
- message->block_index + message->block_length);
- if (not hasNotPiece(message->piece)) {
- sendPiece(message->return_mailbox, message->piece, message->block_index, message->block_length);
- }
- } else {
- XBT_DEBUG("\t for piece %d but he is choked.", message->peer_id);
- }
- break;
- case MESSAGE_PIECE:
- XBT_DEBUG(" \t for piece %d (%d,%d)", message->piece, message->block_index,
- message->block_index + message->block_length);
- xbt_assert(not remote_peer->choked_download);
- xbt_assert(not remote_peer->choked_download, "Can't received a piece if I'm choked !");
- xbt_assert((message->piece >= 0 && static_cast<unsigned int>(message->piece) < FILE_PIECES),
- "Wrong piece received");
- // TODO: Execute a computation.
- if (hasNotPiece(static_cast<unsigned int>(message->piece))) {
- updateBitfieldBlocks(message->piece, message->block_index, message->block_length);
- if (hasCompletedPiece(static_cast<unsigned int>(message->piece))) {
- // Removing the piece from our piece list
- removeCurrentPiece(remote_peer, message->piece);
- // Setting the fact that we have the piece
- bitfield_ = bitfield_ | (1U << static_cast<unsigned int>(message->piece));
- XBT_DEBUG("My status is now %s", getStatus().c_str());
- // Sending the information to all the peers we are connected to
- sendHaveToAllPeers(message->piece);
- // sending UNINTERESTED to peers that do not have what we want.
- updateInterestedAfterReceive();
- } else { // piece not completed
- sendRequestTo(remote_peer, message->piece); // ask for the next block
- }
- } else {
- XBT_DEBUG("However, we already have it");
- requestNewPieceTo(remote_peer);
- }
- break;
- case MESSAGE_CANCEL:
- break;
- default:
- THROW_IMPOSSIBLE;
- }
- // Update the peer speed.
- if (remote_peer) {
- remote_peer->addSpeedValue(1.0 / (simgrid::s4u::Engine::get_clock() - begin_receive_time));
- }
- begin_receive_time = simgrid::s4u::Engine::get_clock();
-}
-
-/** Selects the appropriate piece to download and requests it to the remote_peer */
-void Peer::requestNewPieceTo(Connection* remote_peer)
-{
- int piece = selectPieceToDownload(remote_peer);
- if (piece != -1) {
- current_pieces |= (1U << (unsigned int)piece);
- sendRequestTo(remote_peer, piece);
- }
-}
-
-void Peer::removeCurrentPiece(Connection* remote_peer, unsigned int current_piece)
-{
- current_pieces &= ~(1U << current_piece);
- remote_peer->current_piece = -1;
-}
-
-/** @brief Return the piece to be downloaded
- * There are two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole :
- * If a piece is partially downloaded, this piece will be selected prioritarily
- * If the peer has strictly less than 4 pieces, he chooses a piece at random.
- * If the peer has more than pieces, he downloads the pieces that are the less replicated (rarest policy).
- * If all pieces have been downloaded or requested, we select a random requested piece (endgame mode).
- * @param remote_peer: information about the connection
- * @return the piece to download if possible. -1 otherwise
- */
-int Peer::selectPieceToDownload(const Connection* remote_peer)
-{
- int piece = partiallyDownloadedPiece(remote_peer);
- // strict priority policy
- if (piece != -1)
- return piece;
-
- // end game mode
- if (countPieces(current_pieces) >= (FILE_PIECES - countPieces(bitfield_)) && isInterestedBy(remote_peer)) {
- int nb_interesting_pieces = 0;
- // compute the number of interesting pieces
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (remotePeerHasMissingPiece(remote_peer, i))
- nb_interesting_pieces++;
-
- xbt_assert(nb_interesting_pieces != 0);
- // get a random interesting piece
- int random_piece_index = random.uniform_int(0, nb_interesting_pieces - 1);
- int current_index = 0;
- for (unsigned int i = 0; i < FILE_PIECES; i++) {
- if (remotePeerHasMissingPiece(remote_peer, i)) {
- if (random_piece_index == current_index) {
- piece = i;
- break;
- }
- current_index++;
- }
- }
- xbt_assert(piece != -1);
- return piece;
- }
- // Random first policy
- if (countPieces(bitfield_) < 4 && isInterestedByFree(remote_peer)) {
- int nb_interesting_pieces = 0;
- // compute the number of interesting pieces
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i))
- nb_interesting_pieces++;
- xbt_assert(nb_interesting_pieces != 0);
- // get a random interesting piece
- int random_piece_index = random.uniform_int(0, nb_interesting_pieces - 1);
- int current_index = 0;
- for (unsigned int i = 0; i < FILE_PIECES; i++) {
- if (remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i)) {
- if (random_piece_index == current_index) {
- piece = i;
- break;
- }
- current_index++;
- }
- }
- xbt_assert(piece != -1);
- return piece;
- } else { // Rarest first policy
- short min = SHRT_MAX;
- int nb_min_pieces = 0;
- int current_index = 0;
- // compute the smallest number of copies of available pieces
- for (unsigned int i = 0; i < FILE_PIECES; i++) {
- if (pieces_count[i] < min && remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i))
- min = pieces_count[i];
- }
-
- xbt_assert(min != SHRT_MAX || not isInterestedByFree(remote_peer));
- // compute the number of rarest pieces
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (pieces_count[i] == min && remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i))
- nb_min_pieces++;
-
- xbt_assert(nb_min_pieces != 0 || not isInterestedByFree(remote_peer));
- // get a random rarest piece
- int random_rarest_index = 0;
- if (nb_min_pieces > 0) {
- random_rarest_index = random.uniform_int(0, nb_min_pieces - 1);
- }
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (pieces_count[i] == min && remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i)) {
- if (random_rarest_index == current_index) {
- piece = i;
- break;
- }
- current_index++;
- }
-
- xbt_assert(piece != -1 || not isInterestedByFree(remote_peer));
- return piece;
- }
-}
-
-void Peer::updateChokedPeers()
-{
- if (nbInterestedPeers() == 0)
- return;
- XBT_DEBUG("(%d) update_choked peers %zu active peers", id, active_peers.size());
- // update the current round
- round_ = (round_ + 1) % 3;
- Connection* chosen_peer = nullptr;
- // select first active peer and remove it from the set
- Connection* choked_peer;
- if (active_peers.empty()) {
- choked_peer = nullptr;
- } else {
- choked_peer = *active_peers.begin();
- active_peers.erase(choked_peer);
- }
-
- /**If we are currently seeding, we unchoke the peer which has been unchoked the last time.*/
- if (hasFinished()) {
- double unchoke_time = simgrid::s4u::Engine::get_clock() + 1;
- for (auto& kv : connected_peers) {
- Connection& remote_peer = kv.second;
- if (remote_peer.last_unchoke < unchoke_time && remote_peer.interested && remote_peer.choked_upload) {
- unchoke_time = remote_peer.last_unchoke;
- chosen_peer = &remote_peer;
- }
- }
- } else {
- // Random optimistic unchoking
- if (round_ == 0) {
- int j = 0;
- do {
- // We choose a random peer to unchoke.
- std::unordered_map<int, Connection>::iterator chosen_peer_it = connected_peers.begin();
- std::advance(chosen_peer_it, random.uniform_int(0, connected_peers.size() - 1));
- chosen_peer = &chosen_peer_it->second;
- if (not chosen_peer->interested || not chosen_peer->choked_upload)
- chosen_peer = nullptr;
- else
- XBT_DEBUG("Nothing to do, keep going");
- j++;
- } while (chosen_peer == nullptr && j < MAXIMUM_PEERS);
- } else {
- // Use the "fastest download" policy.
- double fastest_speed = 0.0;
- for (auto& kv : connected_peers) {
- Connection& remote_peer = kv.second;
- if (remote_peer.peer_speed > fastest_speed && remote_peer.choked_upload && remote_peer.interested) {
- fastest_speed = remote_peer.peer_speed;
- chosen_peer = &remote_peer;
- }
- }
- }
- }
-
- if (chosen_peer != nullptr)
- XBT_DEBUG("(%d) update_choked peers unchoked (%d) ; int (%d) ; choked (%d) ", id, chosen_peer->id,
- chosen_peer->interested, chosen_peer->choked_upload);
-
- if (choked_peer != chosen_peer) {
- if (choked_peer != nullptr) {
- xbt_assert(not choked_peer->choked_upload, "Tries to choked a choked peer");
- choked_peer->choked_upload = true;
- updateActivePeersSet(choked_peer);
- XBT_DEBUG("(%d) Sending a CHOKE to %d", id, choked_peer->id);
- sendMessage(choked_peer->mailbox_, MESSAGE_CHOKE, MESSAGE_CHOKE_SIZE);
- }
- if (chosen_peer != nullptr) {
- xbt_assert((chosen_peer->choked_upload), "Tries to unchoked an unchoked peer");
- chosen_peer->choked_upload = false;
- active_peers.insert(chosen_peer);
- chosen_peer->last_unchoke = simgrid::s4u::Engine::get_clock();
- XBT_DEBUG("(%d) Sending a UNCHOKE to %d", id, chosen_peer->id);
- updateActivePeersSet(chosen_peer);
- sendMessage(chosen_peer->mailbox_, MESSAGE_UNCHOKE, MESSAGE_UNCHOKE_SIZE);
- }
- }
-}
-
-/** @brief Update "interested" state of peers: send "not interested" to peers that don't have any more pieces we want.*/
-void Peer::updateInterestedAfterReceive()
-{
- for (auto& kv : connected_peers) {
- Connection& remote_peer = kv.second;
- if (remote_peer.am_interested) {
- bool interested = false;
- // Check if the peer still has a piece we want.
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (remotePeerHasMissingPiece(&remote_peer, i)) {
- interested = true;
- break;
- }
-
- if (not interested) { // no more piece to download from connection
- remote_peer.am_interested = false;
- sendMessage(remote_peer.mailbox_, MESSAGE_NOTINTERESTED, MESSAGE_NOTINTERESTED_SIZE);
- }
- }
- }
-}
-
-void Peer::updateBitfieldBlocks(int piece, int block_index, int block_length)
-{
- xbt_assert((piece >= 0 && static_cast<unsigned int>(piece) <= FILE_PIECES), "Wrong piece.");
- xbt_assert((block_index >= 0 && static_cast<unsigned int>(block_index) <= PIECES_BLOCKS), "Wrong block : %d.",
- block_index);
- for (int i = block_index; i < (block_index + block_length); i++)
- bitfield_blocks |= (1ULL << static_cast<unsigned int>(piece * PIECES_BLOCKS + i));
-}
-
-bool Peer::hasCompletedPiece(unsigned int piece) const
-{
- for (unsigned int i = 0; i < PIECES_BLOCKS; i++)
- if (not(bitfield_blocks & 1ULL << (piece * PIECES_BLOCKS + i)))
- return false;
- return true;
-}
-
-int Peer::getFirstMissingBlockFrom(int piece) const
-{
- for (unsigned int i = 0; i < PIECES_BLOCKS; i++)
- if (not(bitfield_blocks & 1ULL << (piece * PIECES_BLOCKS + i)))
- return i;
- return -1;
-}
-
-/** Returns a piece that is partially downloaded and stored by the remote peer if any -1 otherwise. */
-int Peer::partiallyDownloadedPiece(const Connection* remote_peer) const
-{
- for (unsigned int i = 0; i < FILE_PIECES; i++)
- if (remotePeerHasMissingPiece(remote_peer, i) && isNotDownloadingPiece(i) && getFirstMissingBlockFrom(i) > 0)
- return i;
- return -1;
-}