UrlVisitedActor.java

package io.monokkel.actors;

import akka.actor.Props;
import akka.actor.UntypedActor;
import com.google.common.collect.Sets;
import io.monokkel.messages.AddUrlsToVisitedSet;
import io.monokkel.messages.IsUrlVisitedBefore;
import io.monokkel.messages.UrlAdded;
import io.monokkel.messages.UrlIsNotVisitedBefore;
import org.slf4j.LoggerFactory;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * Created by tarjei on 28/05/14.
 */
public class UrlVisitedActor extends UntypedActor {

    private static final Integer DISABLED_MAX_DEPTH = -1;

    private org.slf4j.Logger log = LoggerFactory.getLogger(UrlVisitedActor.class);

    public static Props props() {
        return Props.create(UrlVisitedActor.class, UrlVisitedActor::new);
    }

    private Set<String> urlVisitedRepo = Collections.synchronizedSet(Sets.newHashSet());

    @Override
    public void onReceive(Object message) throws Exception {
        if (message instanceof IsUrlVisitedBefore) {
            IsUrlVisitedBefore isUrlVisitedBefore = (IsUrlVisitedBefore) message;
            final List<String> urls = isUrlVisitedBefore.getUrls();
            log.debug("Urls are tested {}", urls);

            final boolean disabled = isUrlVisitedBefore.getMaxDepth().equals(DISABLED_MAX_DEPTH);
            if (isUrlVisitedBefore.getDepth() < isUrlVisitedBefore.getMaxDepth() || disabled) {
                final List<String> urlsToVisit = urls.parallelStream().filter(url -> !urlVisitedRepo.contains(url)).collect(Collectors.toList());
                log.debug("Urls to visit {}", urlsToVisit);

                getSender().tell(new UrlIsNotVisitedBefore(urlsToVisit, isUrlVisitedBefore.getDepth(), isUrlVisitedBefore.getMaxDepth()), getSelf());
            } else {
                log.debug("Url hit max depth settings at depth {}",isUrlVisitedBefore.getDepth());
            }
        } else if (message instanceof AddUrlsToVisitedSet) {
            AddUrlsToVisitedSet addUrlsToVisitedSet = (AddUrlsToVisitedSet) message;
            final List<String> urls = addUrlsToVisitedSet.getUrls();
            urlVisitedRepo.addAll(urls);
            getSender().tell(new UrlAdded(), getSender());
        } else {
            unhandled(message);
        }
    }
}