es.uam.eps.ir.relison.diffusion.selections.LooseTimestampBasedSelectionMechanism Maven / Gradle / Ivy
/*
* Copyright (C) 2020 Information Retrieval Group at Universidad Autónoma
* de Madrid, http://ir.ii.uam.es
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
package es.uam.eps.ir.relison.diffusion.selections;
import es.uam.eps.ir.relison.diffusion.data.Data;
import es.uam.eps.ir.relison.diffusion.data.PropagatedInformation;
import es.uam.eps.ir.relison.diffusion.simulation.SimulationState;
import es.uam.eps.ir.relison.diffusion.simulation.UserState;
import java.io.Serializable;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Selection mechanism that takes the real timestamps of the users into account. Each own piece of information
* is released when the timestamp of the piece is equal to the timestamp of the simulation. No information pieces
* are repropagated.
*
* Information pieces from other users are propagated if they are received and the timestamp of the real propagation
* is smaller or equal than the current one.
*
* @author Javier Sanz-Cruzado ([email protected])
* @author Pablo Castells ([email protected])
*
* @param type of the users.
* @param type of the information pieces.
* @param type of the parameters.
*/
public class LooseTimestampBasedSelectionMechanism extends TimestampBasedSelectionMechanism
{
/**
* Map containing, for each user, the information pieces which should have been propagated
* in the past (originated in other users), but have not been propagated yet, because
* the piece was not previously received.
*/
private final Map> notProp = new ConcurrentHashMap<>();
@Override
protected List getReceivedInformation(UserState user, Data data, SimulationState state, int numIter, Long timestamp)
{
U u = user.getUserId();
List prop = new ArrayList<>();
int uidx = data.getUserIndex().object2idx(user.getUserId());
// If some piece which should have been propagated has not been received until now, propagate it!
if(notProp.containsKey(u))
{
notProp.get(u).forEach(i ->
{
if(user.containsReceivedInformation(i))
{
prop.add(new PropagatedInformation(i, numIter, uidx));
/*notProp.get(u).remove(i);
if(notProp.get(u).isEmpty()) notProp.remove(u);*/
}
});
for(PropagatedInformation p : prop)
{
notProp.get(u).remove(p.getInfoId());
if(notProp.get(u).isEmpty()) notProp.remove(u);
}
}
// In case the timestamp is null, there will not be more pieces.
if(timestamp != null)
{
data.getRealPropPiecesByTimestamp(timestamp, u).forEach(i ->
{
int iidx = data.getInformationPiecesIndex().object2idx(i);
if(user.containsReceivedInformation(iidx))
{
prop.add(new PropagatedInformation(iidx, numIter, uidx));
}
else
{
if(!notProp.containsKey(u))
{
notProp.put(u, new HashSet<>());
}
notProp.get(u).add(iidx);
}
});
}
return prop;
}
@Override
public Stream getSelectableUsers(Data data, SimulationState state, int numIter, Long timestamp)
{
Set set;
if(timestamp != null)
{
set = data.getUsersByTimestamp(timestamp).collect(Collectors.toCollection(HashSet::new));
data.getRealPropUsersByTimestamp(timestamp).forEach(set::add);
}
else
{
set = new HashSet<>();
}
set.addAll(notProp.keySet());
return set.stream();
}
}