/*
* Created on Apr 5, 2005
* Created by Alon Rohter
* Copyright (C) 2005, 2006 Aelitis, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* AELITIS, SAS au capital de 46,603.30 euros
* 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
*
*/
package com.aelitis.azureus.core.peermanager.unchoker;
import java.util.ArrayList;
import java.util.Iterator;
import org.gudy.azureus2.core3.disk.DiskManager;
import org.gudy.azureus2.core3.peer.impl.PEPeerTransport;
/**
* Unchoker implementation to be used while in downloading mode.
*/
public class DownloadingUnchoker implements Unchoker {
private ArrayList chokes = new ArrayList();
private ArrayList unchokes = new ArrayList();
public DownloadingUnchoker() {
/* nothing */
}
public ArrayList getImmediateUnchokes( int max_to_unchoke, ArrayList all_peers ) {
ArrayList to_unchoke = new ArrayList();
//count all the currently unchoked peers
int num_unchoked = 0;
for( int i=0; i < all_peers.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)all_peers.get( i );
if( !peer.isChokedByMe() ) num_unchoked++;
}
//if not enough unchokes
int needed = max_to_unchoke - num_unchoked;
if( needed > 0 ) {
for( int i=0; i < needed; i++ ) {
PEPeerTransport peer = UnchokerUtil.getNextOptimisticPeer( all_peers, true, true );
if( peer == null ) break; //no more new unchokes avail
to_unchoke.add( peer );
peer.setOptimisticUnchoke( true );
}
}
return to_unchoke;
}
public void calculateUnchokes( int max_to_unchoke, ArrayList all_peers, boolean force_refresh ) {
int max_optimistic = ((max_to_unchoke - 1) / 10) + 1; //one optimistic unchoke for every 10 upload slots
ArrayList optimistic_unchokes = new ArrayList();
ArrayList best_peers = new ArrayList();
long[] bests = new long[ max_to_unchoke ]; //ensure we never pick more slots than allowed to unchoke
//get all the currently unchoked peers
for( int i=0; i < all_peers.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)all_peers.get( i );
if( !peer.isChokedByMe() ) {
if( UnchokerUtil.isUnchokable( peer, true ) ) {
unchokes.add( peer );
if( peer.isOptimisticUnchoke() ) {
optimistic_unchokes.add( peer );
}
}
else { //should be immediately choked
chokes.add( peer );
}
}
}
if( !force_refresh ) { //ensure current optimistic unchokes remain unchoked
for( int i=0; i < optimistic_unchokes.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)optimistic_unchokes.get( i );
if( i < max_optimistic ) {
best_peers.add( peer ); //add them to the front of the "best" list
}
else { //too many optimistics
peer.setOptimisticUnchoke( false );
}
}
}
//fill slots with peers who we are currently downloading the fastest from
int start_pos = best_peers.size();
for( int i=0; i < all_peers.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)all_peers.get( i );
if( peer.isInteresting() && UnchokerUtil.isUnchokable( peer, false ) && !best_peers.contains( peer ) ) { //viable peer found
long rate = peer.getStats().getSmoothDataReceiveRate();
if( rate > 256 ) { //filter out really slow peers
UnchokerUtil.updateLargestValueFirstSort( rate, bests, peer, best_peers, start_pos );
}
}
}
//if we havent yet picked enough slots
if( best_peers.size() < max_to_unchoke ) {
start_pos = best_peers.size();
//fill the remaining slots with peers that we have downloaded from in the past
for( int i=0; i < all_peers.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)all_peers.get( i );
if( peer.isInteresting() && UnchokerUtil.isUnchokable( peer, false ) && !best_peers.contains( peer ) ) { //viable peer found
long uploaded_ratio = peer.getStats().getTotalDataBytesSent() / (peer.getStats().getTotalDataBytesReceived() + (DiskManager.BLOCK_SIZE-1));
//make sure we haven't already uploaded several times as much data as they've sent us
if( uploaded_ratio <3) {
UnchokerUtil.updateLargestValueFirstSort( peer.getStats().getTotalDataBytesReceived(), bests, peer, best_peers, start_pos );
}
}
}
}
if( force_refresh ) {
//make space for new optimistic unchokes
while( best_peers.size() > max_to_unchoke - max_optimistic ) {
best_peers.remove( best_peers.size() - 1 );
}
}
//if we still have remaining slots
while( best_peers.size() < max_to_unchoke ) {
PEPeerTransport peer = UnchokerUtil.getNextOptimisticPeer( all_peers, true, true ); //just pick one optimistically
if( peer == null ) break; //no more new unchokes avail
if( !best_peers.contains( peer ) ) {
best_peers.add( peer );
peer.setOptimisticUnchoke( true );
}
else {
//we're here because the given optimistic peer is already "best", but is choked still,
//which means it will continually get picked by the getNextOptimisticPeer() method,
//and we'll loop forever if there are no other peers to choose from
peer.sendUnChoke(); //send unchoke immediately, so it won't get picked optimistically anymore
//all_peers.remove( peer ); //remove from all_peers list, so it won't get picked optimistically anymore //TODO
}
}
//update chokes
for( Iterator it = unchokes.iterator(); it.hasNext(); ) {
PEPeerTransport peer = (PEPeerTransport)it.next();
if( !best_peers.contains( peer ) ) { //should be choked
if( best_peers.size() < max_to_unchoke ) { //but there are still slots needed (no optimistics avail), so don't bother choking them
best_peers.add( peer );
}
else {
chokes.add( peer );
it.remove();
}
}
}
//update unchokes
for( int i=0; i < best_peers.size(); i++ ) {
PEPeerTransport peer = (PEPeerTransport)best_peers.get( i );
if( !unchokes.contains( peer ) ) {
unchokes.add( peer );
}
}
}
public ArrayList getChokes() {
ArrayList to_choke = chokes;
chokes = new ArrayList();
return to_choke;
}
public ArrayList getUnchokes() {
ArrayList to_unchoke = unchokes;
unchokes = new ArrayList();
return to_unchoke;
}
}
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