io.mandrel.frontier.Revisitor.java Source code

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Here is the source code for io.mandrel.frontier.Revisitor.java

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/*
 * Licensed to Mandrel under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Mandrel licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package io.mandrel.frontier;

import io.mandrel.metadata.MetadataStore;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.commons.collections.CollectionUtils;

import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;

@Slf4j
@RequiredArgsConstructor
public class Revisitor implements Runnable {

    private final AtomicBoolean run = new AtomicBoolean(false);

    private final Frontier frontier;
    private final MetadataStore metadatastore;

    public void start() {
        run.set(true);
    }

    public void pause() {
        run.set(false);
    }

    public boolean isRunning() {
        return run.get();
    }

    @Override
    public void run() {

        while (true) {

            if (!run.get()) {
                log.trace("Waiting...");
                try {
                    TimeUnit.MILLISECONDS.sleep(2000);
                } catch (InterruptedException e) {
                    // Don't care
                    log.trace("", e);
                }
                continue;
            }

            metadatastore.byPages(1000, entries -> {
                try {
                    if (entries != null) {
                        entries.forEach(entry -> {
                            if (frontier.revisit().isScheduledForRevisit(entry)) {
                                frontier.schedule(entry.getUri());
                            }
                        });
                    }
                } catch (Exception e) {
                    log.debug("Uhhh...", e);
                    return false;
                }
                return CollectionUtils.isNotEmpty(entries);
            });
        }
    }
}