io.druid.server.lookup.PollingLookupFactory.java Source code

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Here is the source code for io.druid.server.lookup.PollingLookupFactory.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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.druid.server.lookup;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonTypeName;
import com.google.common.annotations.VisibleForTesting;
import io.druid.java.util.common.logger.Logger;
import io.druid.query.lookup.LookupExtractorFactory;
import io.druid.query.lookup.LookupIntrospectHandler;
import io.druid.server.lookup.cache.polling.PollingCacheFactory;
import org.joda.time.Period;

import javax.annotation.Nullable;
import java.util.concurrent.atomic.AtomicBoolean;

@JsonTypeName("pollingLookup")
public class PollingLookupFactory implements LookupExtractorFactory {
    private static final Logger LOGGER = new Logger(PollingLookupFactory.class);

    @JsonProperty("pollPeriod")
    private final Period pollPeriod;

    @JsonProperty("dataFetcher")
    private final DataFetcher dataFetcher;

    @JsonProperty("cacheProvider")
    private final PollingCacheFactory cacheFactory;

    private final PollingLookup pollingLookup;

    private final AtomicBoolean started = new AtomicBoolean(false);

    private final String id = Integer.toHexString(System.identityHashCode(this));

    @JsonCreator
    public PollingLookupFactory(@JsonProperty("pollPeriod") Period pollPeriod,
            @JsonProperty("dataFetcher") DataFetcher dataFetcher,
            @JsonProperty("cacheFactory") PollingCacheFactory cacheFactory) {
        this.pollPeriod = pollPeriod == null ? Period.ZERO : pollPeriod;
        this.dataFetcher = dataFetcher;
        this.cacheFactory = cacheFactory;
        this.pollingLookup = new PollingLookup(this.pollPeriod.toStandardDuration().getMillis(), this.dataFetcher,
                this.cacheFactory);
    }

    @VisibleForTesting
    protected PollingLookupFactory(Period pollPeriod, DataFetcher dataFetcher,
            PollingCacheFactory pollingCacheFactory, PollingLookup pollingLookup) {
        this.pollPeriod = pollPeriod;
        this.dataFetcher = dataFetcher;
        this.cacheFactory = pollingCacheFactory;
        this.pollingLookup = pollingLookup;
    }

    @Override
    public boolean start() {
        synchronized (started) {
            if (!started.get()) {
                LOGGER.info("started polling lookup [%s]", id);
                started.set(pollingLookup.isOpen());
            }
            return started.get();
        }
    }

    @Override
    public boolean close() {
        synchronized (started) {
            if (started.getAndSet(false)) {
                LOGGER.info("closing polling lookup [%s]", id);
                pollingLookup.close();
            }
            return !started.get();
        }
    }

    @Override
    public boolean replaces(@Nullable LookupExtractorFactory lookupExtractorFactory) {
        if (lookupExtractorFactory == null) {
            return true;
        }

        return !this.equals(lookupExtractorFactory);
    }

    @Nullable
    @Override
    public LookupIntrospectHandler getIntrospectHandler() {
        //not supported yet
        return null;
    }

    @Override
    public PollingLookup get() {
        return pollingLookup;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof PollingLookupFactory)) {
            return false;
        }

        PollingLookupFactory that = (PollingLookupFactory) o;

        if (pollPeriod != null ? !pollPeriod.equals(that.pollPeriod) : that.pollPeriod != null) {
            return false;
        }
        if (dataFetcher != null ? !dataFetcher.equals(that.dataFetcher) : that.dataFetcher != null) {
            return false;
        }
        return cacheFactory != null
                ? (that.cacheFactory != null && cacheFactory.getClass() == (that.cacheFactory).getClass())
                : that.cacheFactory == null;

    }
}