org.apache.ambari.view.internal.actor.repository.Scanner.java Source code

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Here is the source code for org.apache.ambari.view.internal.actor.repository.Scanner.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 org.apache.ambari.view.internal.actor.repository;

import akka.actor.AbstractLoggingActor;
import akka.actor.Cancellable;
import akka.actor.Props;
import akka.japi.pf.ReceiveBuilder;
import org.apache.ambari.view.web.model.dto.ws.ApplicationsWrapper;
import org.apache.ambari.view.web.service.PackageScannerService;
import org.apache.http.client.utils.URIBuilder;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;
import scala.PartialFunction;
import scala.concurrent.duration.Duration;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Date;
import java.util.Optional;
import java.util.concurrent.TimeUnit;

/**
 *
 */
public class Scanner extends AbstractLoggingActor {
    private final String name;
    private final String url;
    private boolean stopped = false;

    private final RestTemplate ws;
    private final PackageScannerService packageService;
    private Cancellable currentScheduler;

    private Scanner(String name, String url, PackageScannerService packageScannerService, RestTemplate ws) {
        this.name = name;
        this.url = url;
        this.packageService = packageScannerService;
        this.ws = ws;

    }

    public static Props props(String name, String url, PackageScannerService packageScannerService,
            RestTemplate ws) {
        return Props.create(Scanner.class, name, url, packageScannerService, ws);
    }

    @Override
    public PartialFunction receive() {
        return ReceiveBuilder.match(Start.class, this::startHandler).match(Stop.class, this::stopHandler)
                .match(Rescan.class, this::rescanHandler).build();
    }

    private void startHandler(Start message) {
        log().info("Starting '{}' scanner for scanning of new packages.", name);
        this.stopped = false;
        scan();
    }

    private void stopHandler(Stop message) {
        log().info("Stopping '{}' scanner for scanning of new packages.", name);
        stopped = true;
        currentScheduler.cancel();
        packageService.scaningStopped(name);
    }

    private void rescanHandler(Rescan message) {
        if (!stopped)
            scan();
    }

    // TODO: Implement this.
    private void scan() {
        log().info("Scanning URL '{}' for new packages.", url);

        Optional<Date> lastScannedTs = packageService.getLastScannedTimestamp(name);
        Long lastScanned = lastScannedTs.map(Date::getTime).orElse(0L);

        URI uri = null;

        try {
            URIBuilder builder = new URIBuilder(url);
            builder.addParameter("after", String.valueOf(lastScanned));
            uri = builder.build();
        } catch (URISyntaxException e) {
            throw new RestClientException("URL Syntax error", e);
        }

        ApplicationsWrapper wrapper = ws.getForObject(uri, ApplicationsWrapper.class);
        packageService.updateApplications(wrapper.getApplications(), name);

        // Do Something
        scheduleRescanMessage();
    }

    private void scheduleRescanMessage() {
        currentScheduler = context().system().scheduler().scheduleOnce(Duration.create(120, TimeUnit.SECONDS),
                self(), new Rescan(), context().dispatcher(), self());
    }

    @Override
    public void postRestart(Throwable reason) throws Exception {
        log().info("Scanner '{}' restarted.", name);
        scheduleRescanMessage();
        super.postRestart(reason);
    }

    public static class Start {
    }

    public static class Stop {
    }

    private static class Rescan {
    }
}