- /* Copyright (c) 2012. The SimGrid Team.
- * All rights reserved. */
+/* Copyright (c) 2012. 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 "messages.h"
#include <msg/msg.h>
#include <xbt/RngStream.h>
+#include <limits.h>
XBT_LOG_NEW_DEFAULT_CATEGORY(msg_peers, "Messages specific for the peers");
//TODO: Let users change this
/*
* File transfered data
- *
+ * For the test, default values are :
* File size: 10 pieces * 5 blocks/piece * 16384 bytes/block = 819200 bytes
*/
-static int FILE_SIZE = 10 * 5 * 16384;
-static int FILE_PIECES = 10;
-static int PIECES_BLOCKS = 5;
-static int BLOCK_SIZE = 16384;
-static int BLOCKS_REQUESTED = 2;
+#define FILE_PIECES 10
+#define PIECES_BLOCKS 5
+#define BLOCK_SIZE 16384
/**
+ * Number of blocks asked by each request
+ */
+#define BLOCKS_REQUESTED 2
+
+
+static const int FILE_SIZE = FILE_PIECES * PIECES_BLOCKS * BLOCK_SIZE;
+
+void request_new_piece_to_peer(peer_t peer, connection_t remote_peer);
+void send_request_to_peer(peer_t peer, connection_t remote_peer, int piece);
+void remove_current_piece(peer_t peer, connection_t remote_peer, int current_piece);
+
+
+ /**
* Peer main function
*/
int peer(int argc, char *argv[])
seed_loop(&peer, deadline);
} else {
leech_loop(&peer, deadline);
+// XBT_INFO("%d becomes a seeder", peer.id);
seed_loop(&peer, deadline);
}
} else {
*/
send_handshake_all(peer);
//Wait for at least one "bitfield" message.
- wait_for_pieces(peer, deadline);
+// wait_for_pieces(peer, deadline);
XBT_DEBUG("Starting main leech loop");
+
while (MSG_get_clock() < deadline && peer->pieces < FILE_PIECES) {
if (peer->comm_received == NULL) {
+// XBT_INFO("irecv");
peer->task_received = NULL;
peer->comm_received =
MSG_task_irecv(&peer->task_received, peer->mailbox);
}
if (MSG_comm_test(peer->comm_received)) {
+// XBT_INFO("comm_test OK");
msg_error_t status = MSG_comm_get_status(peer->comm_received);
MSG_comm_destroy(peer->comm_received);
peer->comm_received = NULL;
}
} else {
handle_pending_sends(peer);
- if (peer->current_piece != -1) {
- send_interested_to_peers(peer);
- } else {
- //If the current interested pieces is < MAX
- if (peer->pieces_requested < MAX_PIECES) {
- update_current_piece(peer);
- }
- }
//We don't execute the choke algorithm if we don't already have a piece
if (MSG_get_clock() >= next_choked_update && peer->pieces > 0) {
update_choked_peers(peer);
peer->pieces = 0;
peer->pieces_count = xbt_new0(short, FILE_PIECES);
- peer->pieces_requested = 0;
peer->current_pieces = xbt_dynar_new(sizeof(int), NULL);
- peer->current_piece = -1;
- peer->stream = MSG_host_get_data(MSG_host_self());
+ peer->stream = RngStream_CreateStream("");
peer->comm_received = NULL;
peer->round = 0;
xbt_free(peer->pieces_count);
xbt_free(peer->bitfield);
xbt_free(peer->bitfield_blocks);
+
+ RngStream_DeleteStream(&peer->stream);
}
/**
NULL) ? 1 : 0);
}
+int nb_interested_peers(peer_t peer)
+{
+ xbt_dict_cursor_t cursor = NULL;
+ char *key;
+ connection_t connection;
+ int nb = 0;
+ xbt_dict_foreach(peer->peers, cursor, key, connection) {
+ if (connection->interested)
+ nb++;
+ }
+ return nb;
+}
+
/**
* Handle pending sends and remove those which are done
* @param peer Peer data
}
}
+void update_active_peers_set(peer_t peer, connection_t remote_peer)
+{
+
+ if (remote_peer->interested && !remote_peer->choked_upload) {
+ //add in the active peers set
+ xbt_dict_set_ext(peer->active_peers, (char *) &remote_peer->id,
+ sizeof(int), remote_peer, NULL);
+ } else {
+ //remove
+ xbt_ex_t e;
+ TRY {
+ xbt_dict_remove_ext(peer->active_peers, (char *) &remote_peer->id,
+ sizeof(int));
+ }
+ CATCH(e) {
+ xbt_ex_free(e);
+ }
+ }
+}
+
+
/**
* Handle a received message sent by another peer
* @param peer Peer data
update_pieces_count_from_bitfield(peer, message->bitfield);
//Store the bitfield
remote_peer->bitfield = xbt_strdup(message->bitfield);
- //Update the current piece
- if (peer->current_piece == -1 && peer->pieces < FILE_PIECES) {
- update_current_piece(peer);
+ xbt_assert(!remote_peer->am_interested,
+ "Should not be interested at first");
+ if (is_interested(peer, remote_peer)) {
+ remote_peer->am_interested = 1;
+ send_interested(peer, message->mailbox);
}
break;
case MESSAGE_INTERESTED:
"A non-in-our-list peer has sent us a message. WTH ?");
//Update the interested state of the peer.
remote_peer->interested = 1;
+ update_active_peers_set(peer, remote_peer);
break;
case MESSAGE_NOTINTERESTED:
XBT_DEBUG("Received a NOTINTERESTED message from %s (%s)",
xbt_assert((remote_peer != NULL),
"A non-in-our-list peer has sent us a message. WTH ?");
remote_peer->interested = 0;
+ update_active_peers_set(peer, remote_peer);
break;
case MESSAGE_UNCHOKE:
xbt_assert((remote_peer != NULL),
XBT_DEBUG("Received a UNCHOKE message from %s (%s)", message->mailbox,
message->issuer_host_name);
remote_peer->choked_download = 0;
- xbt_dict_set_ext(peer->active_peers, (char *) &message->peer_id,
- sizeof(int), remote_peer, NULL);
//Send requests to the peer, since it has unchoked us
- send_requests_to_peer(peer, remote_peer);
+ if (remote_peer->am_interested)
+ request_new_piece_to_peer(peer, remote_peer);
break;
case MESSAGE_CHOKE:
xbt_assert((remote_peer != NULL),
XBT_DEBUG("Received a CHOKE message from %s (%s)", message->mailbox,
message->issuer_host_name);
remote_peer->choked_download = 1;
- xbt_ex_t e;
- TRY {
- xbt_dict_remove_ext(peer->active_peers, (char *) &message->peer_id,
- sizeof(int));
- }
- CATCH(e) {
- xbt_ex_free(e);
- }
+ remove_current_piece(peer, remote_peer, remote_peer->current_piece);
break;
case MESSAGE_HAVE:
XBT_DEBUG("Received a HAVE message from %s (%s) of piece %d",
message->mailbox, message->issuer_host_name, message->index);
+ xbt_assert(remote_peer->bitfield, "bitfield not received");
xbt_assert((message->index >= 0
&& message->index < FILE_PIECES),
"Wrong HAVE message received");
- if (remote_peer->bitfield == NULL)
- return;
remote_peer->bitfield[message->index] = '1';
peer->pieces_count[message->index]++;
//If the piece is in our pieces, we tell the peer that we are interested.
- if (!remote_peer->am_interested
- && in_current_pieces(peer, message->index)) {
+ if (!remote_peer->am_interested && peer->bitfield[message->index] == '0') {
remote_peer->am_interested = 1;
- send_interested(peer, remote_peer->mailbox);
+ send_interested(peer, message->mailbox);
+ if (!remote_peer->choked_download)
+ request_new_piece_to_peer(peer, remote_peer);
}
break;
case MESSAGE_REQUEST:
update_bitfield_blocks(peer, message->index, message->block_index,
message->block_length);
if (piece_complete(peer, message->index)) {
- peer->pieces_requested--;
//Removing the piece from our piece list
- unsigned i;
- int piece_index = -1, piece;
- xbt_dynar_foreach(peer->current_pieces, i, piece) {
- if (piece == message->index) {
- piece_index = i;
- break;
- }
- }
- xbt_assert(piece_index != -1, "Received an incorrect piece");
- xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL);
+ remove_current_piece(peer, remote_peer, message->index);
//Setting the fact that we have the piece
peer->bitfield[message->index] = '1';
peer->pieces++;
send_have(peer, message->index);
//sending UNINTERSTED to peers that doesn't have what we want.
update_interested_after_receive(peer);
+ } else { // piece not completed
+ send_request_to_peer(peer, remote_peer, message->index); // ask for the next block
}
} else {
XBT_DEBUG("However, we already have it");
+ request_new_piece_to_peer(peer, remote_peer);
}
}
break;
case MESSAGE_CANCEL:
+ XBT_DEBUG("The received CANCEL from %s (%s)",
+ message->mailbox, message->issuer_host_name);
break;
}
//Update the peer speed.
task_message_free(task);
}
-/**
- * Wait for the node to receive interesting bitfield messages (ie: non empty)
- * to be received
- * @param deadline peer deadline
- * @param peer peer data
- */
-void wait_for_pieces(peer_t peer, double deadline)
+void request_new_piece_to_peer(peer_t peer, connection_t remote_peer)
{
- int finished = 0;
- while (MSG_get_clock() < deadline && !finished) {
- if (peer->comm_received == NULL) {
- peer->task_received = NULL;
- peer->comm_received =
- MSG_task_irecv(&peer->task_received, peer->mailbox);
- }
- msg_error_t status = MSG_comm_wait(peer->comm_received, TIMEOUT_MESSAGE);
- //free the comm already, we don't need it anymore
- MSG_comm_destroy(peer->comm_received);
- peer->comm_received = NULL;
- if (status == MSG_OK) {
- MSG_task_get_data(peer->task_received);
- handle_message(peer, peer->task_received);
- if (peer->current_piece != -1) {
- finished = 1;
- }
+ int piece = select_piece_to_download(peer, remote_peer);
+ if (piece != -1) {
+ xbt_dynar_push_as(peer->current_pieces, int, piece);
+ send_request_to_peer(peer, remote_peer, piece);
+ }
+}
+
+void remove_current_piece(peer_t peer, connection_t remote_peer,
+ int current_piece)
+{
+ int piece_index = -1, piece, i;
+ xbt_dynar_foreach(peer->current_pieces, i, piece) {
+ if (piece == current_piece) {
+ piece_index = i;
+ break;
}
}
+ if (piece_index != -1)
+ xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL);
+ remote_peer->current_piece = -1;
}
/**
}
}
+
+
/**
- * Update the piece the peer is currently interested in.
- * There is two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole :
- * If the peer has less than 3 pieces, he chooses a piece at random.
+ * 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
+ * replicated (rarest policy).
+ * If all pieces have been downloaded or requested, we select a random requested piece (endgame mode).
+
+ * @param peer: local peer
+ * @param remote_peer: information about the connection
+ * @return the piece to download if possible. -1 otherwise
*/
-void update_current_piece(peer_t peer)
+int select_piece_to_download(peer_t peer, connection_t remote_peer)
{
- if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces)) {
- return;
+ int piece = -1;
+
+ piece = partially_downloaded_piece(peer, remote_peer);
+ // strict priority policy
+ if (piece != -1)
+ return piece;
+
+ // end game mode
+ if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces) && is_interested(peer, remote_peer)) {
+ int i;
+ int nb_interesting_pieces = 0;
+ int random_piece_index, current_index = 0;
+ // compute the number of interesting pieces
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') {
+ nb_interesting_pieces++;
+ }
+ }
+ xbt_assert(nb_interesting_pieces != 0, "WTF !!!");
+ // get a random interesting piece
+ random_piece_index = RngStream_RandInt(peer->stream, 0, nb_interesting_pieces-1);
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') {
+ if (random_piece_index == current_index) {
+ piece = i;
+ break;
+ }
+ current_index++;
+ }
+ }
+ xbt_assert(piece != -1,"WTF !!!");
+ return piece;
}
- if (1 || peer->pieces < 3) {
- int i = 0;
- do {
- peer->current_piece =
- RngStream_RandInt(peer->stream, 0, FILE_PIECES - 1);;
- i++;
- } while (!
- (peer->bitfield[peer->current_piece] == '0'
- && !in_current_pieces(peer, peer->current_piece)));
- } else {
- //Trivial min algorithm.
- int i, min_id = -1;
- short min = -1;
+
+ // Random first policy
+ if (peer->pieces < 4 && is_interested_and_free(peer, remote_peer)) {
+ int i;
+ int nb_interesting_pieces = 0;
+ int random_piece_index, current_index = 0;
+ // compute the number of interesting pieces
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) {
+ nb_interesting_pieces++;
+ }
+ }
+ xbt_assert(nb_interesting_pieces != 0, "WTF !!!");
+ // get a random interesting piece
+ random_piece_index = RngStream_RandInt(peer->stream, 0, nb_interesting_pieces-1);
for (i = 0; i < FILE_PIECES; i++) {
- if (peer->bitfield[i] == '0') {
- min = peer->pieces_count[i];
- min_id = i;
- break;
+ if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) {
+ if (random_piece_index == current_index) {
+ piece = i;
+ break;
+ }
+ current_index++;
}
}
- xbt_assert((min > -1), "Couldn't find a minimum");
- for (i = 1; i < FILE_PIECES; i++) {
- if (peer->pieces_count[i] < min && peer->bitfield[i] == '0') {
- min = peer->pieces_count[i];
- min_id = i;
+ xbt_assert(piece != -1,"WTF !!!");
+ return piece;
+ } else { // Rarest first policy
+ int i;
+ short min = SHRT_MAX;
+ int nb_min_pieces = 0;
+ int random_rarest_index, current_index = 0;
+ // compute the smallest number of copies of available pieces
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->pieces_count[i] < min && peer->bitfield[i] == '0'
+ && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i))
+ min = peer->pieces_count[i];
+ }
+ xbt_assert(min != SHRT_MAX || !is_interested_and_free(peer, remote_peer), "WTF !!!");
+ // compute the number of rarest pieces
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->pieces_count[i] == min && peer->bitfield[i] == '0'
+ && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i))
+ nb_min_pieces++;
+ }
+ xbt_assert(nb_min_pieces != 0 || !is_interested_and_free(peer, remote_peer), "WTF !!!");
+ // get a random rarest piece
+ random_rarest_index = RngStream_RandInt(peer->stream, 0, nb_min_pieces-1);
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (peer->pieces_count[i] == min && peer->bitfield[i] == '0'
+ && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) {
+ if (random_rarest_index == current_index) {
+ piece = i;
+ break;
+ }
+ current_index++;
}
}
- peer->current_piece = min_id;
+ xbt_assert(piece != -1 || !is_interested_and_free(peer, remote_peer),"WTF !!!");
+ return piece;
}
- xbt_dynar_push_as(peer->current_pieces, int, peer->current_piece);
- XBT_DEBUG("New interested piece: %d", peer->current_piece);
- xbt_assert((peer->current_piece >= 0 && peer->current_piece < FILE_PIECES),
- "Peer want to retrieve a piece that doesn't exist.");
}
+
/**
* Update the list of current choked and unchoked peers, using the
* choke algorithm
*/
void update_choked_peers(peer_t peer)
{
+ if (nb_interested_peers(peer) == 0)
+ return;
+ // if(xbt_dict_size(peer->active_peers) > 0)
+ // return;
+ XBT_DEBUG("(%d) update_choked peers %d active peers", peer->id,
+ xbt_dict_size(peer->active_peers));
//update the current round
peer->round = (peer->round + 1) % 3;
- char *key;
+ char *key, *key_choked;
connection_t peer_choosed = NULL;
+ connection_t peer_choked = NULL;
//remove a peer from the list
xbt_dict_cursor_t cursor = NULL;
xbt_dict_cursor_first(peer->active_peers, &cursor);
- if (!xbt_dict_is_empty(peer->active_peers)) {
- key = xbt_dict_cursor_get_key(cursor);
- connection_t peer_choked = xbt_dict_cursor_get_data(cursor);
- if (peer_choked) {
- send_choked(peer, peer_choked->mailbox);
- peer_choked->choked_upload = 1;
- }
- xbt_dict_remove_ext(peer->active_peers, key, sizeof(int));
+ if (xbt_dict_length(peer->active_peers) > 0) {
+ key_choked = xbt_dict_cursor_get_key(cursor);
+ peer_choked = xbt_dict_cursor_get_data(cursor);
}
xbt_dict_cursor_free(&cursor);
- /**
- * If we are currently seeding, we unchoke the peer which has
- * been unchoke the least time.
- */
+ /**
+ * If we are currently seeding, we unchoke the peer which has
+ * been unchoke the least time.
+ */
if (peer->pieces == FILE_PIECES) {
connection_t connection;
double unchoke_time = MSG_get_clock() + 1;
xbt_dict_foreach(peer->peers, cursor, key, connection) {
- if (connection->last_unchoke < unchoke_time && connection->interested) {
+ if (connection->last_unchoke < unchoke_time && connection->interested
+ && connection->choked_upload) {
unchoke_time = connection->last_unchoke;
peer_choosed = connection;
}
i++;
}
xbt_dict_cursor_free(&cursor);
- if (peer_choosed->interested == 0) {
+ if (!peer_choosed->interested || !peer_choosed->choked_upload) {
peer_choosed = NULL;
}
j++;
}
}
- if (peer_choosed != NULL) {
- peer_choosed->choked_upload = 0;
- xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id,
- sizeof(int), peer_choosed, NULL);
- peer_choosed->last_unchoke = MSG_get_clock();
- send_unchoked(peer, peer_choosed->mailbox);
- }
+ if (peer_choosed != NULL)
+ XBT_DEBUG
+ ("(%d) update_choked peers unchoked (%d) ; int (%d) ; choked (%d) ",
+ peer->id, peer_choosed->id, peer_choosed->interested,
+ peer_choosed->choked_upload);
+ // if (xbt_dict_size(peer->peers) > 0)
+ // xbt_assert((xbt_dict_size(peer->active_peers) != 0),
+ // "No more active peers !");
+
+
+ // if (peer_choked != NULL && peer_choked->choked_upload != 0)
+ // peer_choked = NULL;
+ // if (peer_choosed != NULL && peer_choosed->choked_upload == 0)
+ // peer_choosed = NULL;
+
+ if (peer_choked != peer_choosed) {
+ if (peer_choked != NULL) {
+ xbt_assert((!peer_choked->choked_upload),
+ "Tries to choked a choked peer");
+ peer_choked->choked_upload = 1;
+ xbt_assert((*((int *) key_choked) == peer_choked->id), "WTF !!!");
+ update_active_peers_set(peer, peer_choked);
+ // xbt_dict_remove_ext(peer->active_peers, key_choked, sizeof(int));
+ XBT_DEBUG("(%d) Sending a CHOKE to %d", peer->id, peer_choked->id);
+ send_choked(peer, peer_choked->mailbox);
+ }
+ if (peer_choosed != NULL) {
+ xbt_assert((peer_choosed->choked_upload),
+ "Tries to unchoked an unchoked peer");
+ peer_choosed->choked_upload = 0;
+ xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id,
+ sizeof(int), peer_choosed, NULL);
+ peer_choosed->last_unchoke = MSG_get_clock();
+ XBT_DEBUG("(%d) Sending a UNCHOKE to %d", peer->id, peer_choosed->id);
+ update_active_peers_set(peer, peer_choosed);
+ send_unchoked(peer, peer_choosed->mailbox);
+ }
+ }
}
/**
xbt_dict_foreach(peer->peers, cursor, key, connection) {
interested = 0;
if (connection->am_interested) {
+ xbt_assert(connection->bitfield, "Bitfield not received");
//Check if the peer still has a piece we want.
- xbt_dynar_foreach(peer->current_pieces, cpt, piece) {
- xbt_assert((piece >= 0), "Wrong piece.");
- if (connection->bitfield && connection->bitfield[piece] == '1') {
+ int i;
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (connection->bitfield[i] == '1' && peer->bitfield[i] == '0') {
interested = 1;
break;
}
}
- if (!interested) {
+ if (!interested) { //no more piece to download from connection
connection->am_interested = 0;
send_notinterested(peer, connection->mailbox);
}
}
/**
- * Returns the first block that a peer doesn't have in a piece
+ * Returns the first block that a peer doesn't have in a piece.
+ * If the peer has all blocks of the piece, returns -1.
*/
int get_first_block(peer_t peer, int piece)
{
return -1;
}
+/**
+ * Indicates if the remote peer has a piece not stored by the local peer
+ */
+int is_interested(peer_t peer, connection_t remote_peer)
+{
+ xbt_assert(remote_peer->bitfield, "Bitfield not received");
+ int i;
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0') {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Indicates if the remote peer has a piece not stored by the local peer nor requested by the local peer
+ */
+int is_interested_and_free(peer_t peer, connection_t remote_peer)
+{
+ xbt_assert(remote_peer->bitfield, "Bitfield not received");
+ int i;
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0'
+ && !in_current_pieces(peer, i)) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+
+/**
+ * Returns a piece that is partially downloaded and stored by the remote peer if any
+ * -1 otherwise.
+ */
+int partially_downloaded_piece(peer_t peer, connection_t remote_peer)
+{
+ xbt_assert(remote_peer->bitfield, "Bitfield not received");
+ int i;
+ for (i = 0; i < FILE_PIECES; i++) {
+ if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0'
+ && !in_current_pieces(peer, i)) {
+ if (get_first_block(peer, i) > 0)
+ return i;
+ }
+ }
+ return -1;
+}
+
+
/**
* Send request messages to a peer that have unchoked us
* @param peer peer
* @param remote_peer peer data to the peer we want to send the request
*/
-void send_requests_to_peer(peer_t peer, connection_t remote_peer)
+void send_request_to_peer(peer_t peer, connection_t remote_peer, int piece)
{
+ remote_peer->current_piece = piece;
unsigned i;
- int piece, block_index, block_length;
- xbt_dynar_foreach(peer->current_pieces, i, piece) {
- if (remote_peer->bitfield && remote_peer->bitfield[piece] == '1') {
- block_index = get_first_block(peer, piece);
- if (block_index != -1) {
- block_length = PIECES_BLOCKS - block_index;
- block_length = min(BLOCKS_REQUESTED, block_length);
- send_request(peer, remote_peer->mailbox, piece, block_index,
- block_length);
- break;
- }
- }
+ int block_index, block_length;
+ xbt_assert(remote_peer->bitfield, "bitfield not received");
+ xbt_assert(remote_peer->bitfield[piece] == '1', "WTF !!!");
+ block_index = get_first_block(peer, piece);
+ if (block_index != -1) {
+ block_length = PIECES_BLOCKS - block_index;
+ block_length = min(BLOCKS_REQUESTED, block_length);
+ send_request(peer, remote_peer->mailbox, piece, block_index,
+ block_length);
}
}
+
/**
- * Find the peers that have the current interested piece and send them
- * the "interested" message
+ * Indicates if a piece is currently being downloaded by the peer.
*/
-void send_interested_to_peers(peer_t peer)
+int in_current_pieces(peer_t peer, int piece)
{
- char *key;
- xbt_dict_cursor_t cursor = NULL;
- connection_t connection;
- xbt_assert((peer->current_piece != -1),
- "Tried to send a interested message wheras the current_piece is -1");
- xbt_dict_foreach(peer->peers, cursor, key, connection) {
- if (connection->bitfield
- && connection->bitfield[peer->current_piece] == '1') {
- connection->am_interested = 1;
- msg_task_t task =
- task_message_new(MESSAGE_INTERESTED, peer->hostname, peer->mailbox,
- peer->id, task_message_size(MESSAGE_INTERESTED));
- MSG_task_dsend(task, connection->mailbox, task_message_free);
- XBT_DEBUG("Send INTERESTED to %s", connection->mailbox);
+ unsigned i;
+ int peer_piece;
+ xbt_dynar_foreach(peer->current_pieces, i, peer_piece) {
+ if (peer_piece == piece) {
+ return 1;
}
}
- peer->current_piece = -1;
- peer->pieces_requested++;
+ return 0;
}
+
+
+
+/***********************************************************
+ *
+ * Low level message functions
+ *
+ ***********************************************************/
+
+
+
/**
* Send a "interested" message to a peer
* @param peer peer data
stalled, block_index, block_length, BLOCK_SIZE);
MSG_task_dsend(task, mailbox, task_message_free);
}
-
-int in_current_pieces(peer_t peer, int piece)
-{
- unsigned i;
- int is_in = 0, peer_piece;
- xbt_dynar_foreach(peer->current_pieces, i, peer_piece) {
- if (peer_piece == piece) {
- is_in = 1;
- break;
- }
- }
- return is_in;
-}
