org.elasticsearch.index.cache.filter.soft.SoftFilterCache.java Source code

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Here is the source code for org.elasticsearch.index.cache.filter.soft.SoftFilterCache.java

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/*
 * Licensed to ElasticSearch and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. ElasticSearch 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 org.elasticsearch.index.cache.filter.soft;

import com.google.common.base.Objects;
import com.google.common.collect.MapEvictionListener;
import com.google.common.collect.MapMaker;
import org.apache.lucene.search.Filter;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.docset.DocSet;
import org.elasticsearch.common.metrics.CounterMetric;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.cache.filter.support.AbstractConcurrentMapFilterCache;
import org.elasticsearch.index.settings.IndexSettings;
import org.elasticsearch.index.settings.IndexSettingsService;

import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;

/**
 * A soft reference based filter cache that has soft keys on the <tt>IndexReader</tt>.
 *
 *
 */
public class SoftFilterCache extends AbstractConcurrentMapFilterCache
        implements MapEvictionListener<Filter, DocSet> {

    private final IndexSettingsService indexSettingsService;

    private volatile int maxSize;
    private volatile TimeValue expire;

    private final CounterMetric evictions = new CounterMetric();

    private final ApplySettings applySettings = new ApplySettings();

    @Inject
    public SoftFilterCache(Index index, @IndexSettings Settings indexSettings,
            IndexSettingsService indexSettingsService) {
        super(index, indexSettings);
        this.indexSettingsService = indexSettingsService;
        this.maxSize = indexSettings.getAsInt("index.cache.filter.max_size",
                componentSettings.getAsInt("max_size", -1));
        this.expire = indexSettings.getAsTime("index.cache.filter.expire",
                componentSettings.getAsTime("expire", null));
        logger.debug("using [soft] filter cache with max_size [{}], expire [{}]", maxSize, expire);

        indexSettingsService.addListener(applySettings);
    }

    @Override
    public void close() {
        indexSettingsService.removeListener(applySettings);
        super.close();
    }

    @Override
    protected ConcurrentMap<Object, DocSet> buildFilterMap() {
        // DocSet are not really stored with strong reference only when searching on them...
        // Filter might be stored in query cache
        MapMaker mapMaker = new MapMaker().softValues();
        if (maxSize != -1) {
            mapMaker.maximumSize(maxSize);
        }
        if (expire != null && expire.nanos() > 0) {
            mapMaker.expireAfterAccess(expire.nanos(), TimeUnit.NANOSECONDS);
        }
        mapMaker.evictionListener(this);
        return mapMaker.makeMap();
    }

    @Override
    public String type() {
        return "soft";
    }

    @Override
    public long evictions() {
        return evictions.count();
    }

    @Override
    public void onEviction(Filter filter, DocSet docSet) {
        evictions.inc();
    }

    static {
        IndexMetaData.addDynamicSettings("index.cache.field.max_size", "index.cache.field.expire");
    }

    class ApplySettings implements IndexSettingsService.Listener {
        @Override
        public void onRefreshSettings(Settings settings) {
            int maxSize = settings.getAsInt("index.cache.filter.max_size", SoftFilterCache.this.maxSize);
            TimeValue expire = settings.getAsTime("index.cache.filter.expire", SoftFilterCache.this.expire);
            boolean changed = false;
            if (maxSize != SoftFilterCache.this.maxSize) {
                logger.info("updating index.cache.filter.max_size from [{}] to [{}]", SoftFilterCache.this.maxSize,
                        maxSize);
                changed = true;
                SoftFilterCache.this.maxSize = maxSize;
            }
            if (!Objects.equal(expire, SoftFilterCache.this.expire)) {
                logger.info("updating index.cache.filter.expire from [{}] to [{}]", SoftFilterCache.this.expire,
                        expire);
                changed = true;
                SoftFilterCache.this.expire = expire;
            }
            if (changed) {
                clear();
            }
        }
    }
}