The Sparse Flooding Algorithm

action onMsgReceived(msg,emitter)
    
    if not(isEntityInDeck(msg.eid)) //No information about the entity in database
        
        if not(isFullDXM(msg))
            sendFullDXMRequest(emitter,msg.eid)
            return //End action and wait for new message
        
        if not(isInteresting(msg))
            return //Discard message
        
        storeEntityInDeck(msg)
        
        foreach neighbors as neighbor
            if neighbor != emitter
                sendDXM(neighbor,msg) //Flood full message
    
    else //There is already a knowledge about the entity in database
    
        currentInfo = getEntityFromDeck(msg.eid)
        
        if msg.timestamp <= currentInfo.timestamp
            return //Message to old
        
        //Make msg a complete InformationCard
        if not(isFullDXM(msg))
            msg = mergeInfos(currentInfo,msg)
            
        //Get the records which have changed
        infoDiff = getInfoChanges(currentInfo,msg)
        
        if isEmpty(infoDiff)
            return //Nothing has changed
        
        if not(isInteresting(msg))
            removeEntityFromDeck(msg.eid)
            return //Discard entity
        
        storeEntityInDeck(msg)
        
        foreach neighbors as neighbor
            if neighbor != emitter
                sendDXM(neighbor,infoDiff) //Flood partial message
    
    return //End action onMsgReceived
    
    
    
action onFullDXMRequestReceived(eid,questioner)
    
    if eid != null //Send particular InformationCard
    
        infoCard = getEntityFromDeck(eid)
        sendDXM(questioner,infoCard)
            
    else //Demand for all known entities
    
        foreach entitiesInDeck as infoCard
            sendDXM(questioner,infoCard)
        
    return //End action onFullDXMRequestReceived