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* Licensed to Elasticsearch 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.bitset;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;
import org.apache.lucene.index.IndexReaderContext;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.ReaderUtil;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Weight;
import org.apache.lucene.search.join.BitSetProducer;
import org.apache.lucene.util.Accountable;
import org.apache.lucene.util.BitDocIdSet;
import org.apache.lucene.util.BitSet;
import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.search.Queries;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.AbstractIndexComponent;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.mapper.DocumentMapper;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.mapper.object.ObjectMapper;
import org.elasticsearch.index.settings.IndexSettingsService;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.shard.ShardUtils;
import org.elasticsearch.indices.IndicesWarmer;
import org.elasticsearch.indices.IndicesWarmer.TerminationHandle;
import org.elasticsearch.threadpool.ThreadPool;
import java.io.Closeable;
import java.io.IOException;
import java.util.HashSet;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.*;
/**
* This is a cache for {@link BitDocIdSet} based filters and is unbounded by size or time.
* <p>
* Use this cache with care, only components that require that a filter is to be materialized as a {@link BitDocIdSet}
* and require that it should always be around should use this cache, otherwise the
* {@link org.elasticsearch.index.cache.query.QueryCache} should be used instead.
*/
public class BitsetFilterCache extends AbstractIndexComponent implements LeafReader.CoreClosedListener, RemovalListener<Object, Cache<Query, BitsetFilterCache.Value>>, Closeable {
public static final String LOAD_RANDOM_ACCESS_FILTERS_EAGERLY = "index.load_fixed_bitset_filters_eagerly";
private static final Listener DEFAULT_NOOP_LISTENER = new Listener() {
@Override
public void onCache(ShardId shardId, Accountable accountable) {
}
@Override
public void onRemoval(ShardId shardId, Accountable accountable) {
}
};
private final boolean loadRandomAccessFiltersEagerly;
private final Cache<Object, Cache<Query, Value>> loadedFilters;
private volatile Listener listener = DEFAULT_NOOP_LISTENER;
private final BitSetProducerWarmer warmer;
private IndicesWarmer indicesWarmer;
@Inject
public BitsetFilterCache(Index index, IndexSettingsService indexSettingsService) {
this(index, indexSettingsService.getSettings());
}
//package private for testing
BitsetFilterCache(Index index, Settings indexSettings) {
super(index, indexSettings);
this.loadRandomAccessFiltersEagerly = indexSettings.getAsBoolean(LOAD_RANDOM_ACCESS_FILTERS_EAGERLY, true);
this.loadedFilters = CacheBuilder.newBuilder().removalListener(this).build();
this.warmer = new BitSetProducerWarmer();
}
@Inject(optional = true)
public void setIndicesWarmer(IndicesWarmer indicesWarmer) {
this.indicesWarmer = indicesWarmer;
indicesWarmer.addListener(warmer);
}
/**
* Sets a listener that is invoked for all subsequent cache and removal events.
* @throws IllegalStateException if the listener is set more than once
*/
public void setListener(Listener listener) {
if (listener == null) {
throw new IllegalArgumentException("listener must not be null");
}
if (this.listener != DEFAULT_NOOP_LISTENER) {
throw new IllegalStateException("can't set listener more than once");
}
this.listener = listener;
}
public BitSetProducer getBitSetProducer(Query query) {
return new QueryWrapperBitSetProducer(query);
}
@Override
public void onClose(Object ownerCoreCacheKey) {
loadedFilters.invalidate(ownerCoreCacheKey);
}
@Override
public void close() {
if (indicesWarmer != null) {
indicesWarmer.removeListener(warmer);
}
clear("close");
}
public void clear(String reason) {
logger.debug("clearing all bitsets because [{}]", reason);
loadedFilters.invalidateAll();
}
private BitSet getAndLoadIfNotPresent(final Query query, final LeafReaderContext context) throws IOException, ExecutionException {
final Object coreCacheReader = context.reader().getCoreCacheKey();
final ShardId shardId = ShardUtils.extractShardId(context.reader());
if (shardId != null // can't require it because of the percolator
&& index.getName().equals(shardId.getIndex()) == false) {
// insanity
throw new IllegalStateException("Trying to load bit set for index [" + shardId.getIndex()
+ "] with cache of index [" + index.getName() + "]");
}
Cache<Query, Value> filterToFbs = loadedFilters.get(coreCacheReader, new Callable<Cache<Query, Value>>() {
@Override
public Cache<Query, Value> call() throws Exception {
context.reader().addCoreClosedListener(BitsetFilterCache.this);
return CacheBuilder.newBuilder().build();
}
});
return filterToFbs.get(query,new Callable<Value>() {
@Override
public Value call() throws Exception {
final IndexReaderContext topLevelContext = ReaderUtil.getTopLevelContext(context);
final IndexSearcher searcher = new IndexSearcher(topLevelContext);
searcher.setQueryCache(null);
final Weight weight = searcher.createNormalizedWeight(query, false);
final Scorer s = weight.scorer(context);
final BitSet bitSet;
if (s == null) {
bitSet = null;
} else {
bitSet = BitSet.of(s.iterator(), context.reader().maxDoc());
}
Value value = new Value(bitSet, shardId);
listener.onCache(shardId, value.bitset);
return value;
}
}).bitset;
}
@Override
public void onRemoval(RemovalNotification<Object, Cache<Query, Value>> notification) {
Object key = notification.getKey();
if (key == null) {
return;
}
Cache<Query, Value> valueCache = notification.getValue();
if (valueCache == null) {
return;
}
for (Value value : valueCache.asMap().values()) {
listener.onRemoval(value.shardId, value.bitset);
// if null then this means the shard has already been removed and the stats are 0 anyway for the shard this key belongs to
}
}
public static final class Value {
final BitSet bitset;
final ShardId shardId;
public Value(BitSet bitset, ShardId shardId) {
this.bitset = bitset;
this.shardId = shardId;
}
}
final class QueryWrapperBitSetProducer implements BitSetProducer {
final Query query;
QueryWrapperBitSetProducer(Query query) {
this.query = Objects.requireNonNull(query);
}
@Override
public BitSet getBitSet(LeafReaderContext context) throws IOException {
try {
return getAndLoadIfNotPresent(query, context);
} catch (ExecutionException e) {
throw ExceptionsHelper.convertToElastic(e);
}
}
@Override
public String toString() {
return "random_access(" + query + ")";
}
@Override
public boolean equals(Object o) {
if (!(o instanceof QueryWrapperBitSetProducer)) return false;
return this.query.equals(((QueryWrapperBitSetProducer) o).query);
}
@Override
public int hashCode() {
return 31 * getClass().hashCode() + query.hashCode();
}
}
final class BitSetProducerWarmer extends IndicesWarmer.Listener {
@Override
public IndicesWarmer.TerminationHandle warmNewReaders(final IndexShard indexShard, IndexMetaData indexMetaData, IndicesWarmer.WarmerContext context, ThreadPool threadPool) {
if (index.getName().equals(context.shardId().getIndex()) == false) {
// this is from a different index
return TerminationHandle.NO_WAIT;
}
if (!loadRandomAccessFiltersEagerly) {
return TerminationHandle.NO_WAIT;
}
boolean hasNested = false;
final Set<Query> warmUp = new HashSet<>();
final MapperService mapperService = indexShard.mapperService();
for (DocumentMapper docMapper : mapperService.docMappers(false)) {
if (docMapper.hasNestedObjects()) {
hasNested = true;
for (ObjectMapper objectMapper : docMapper.objectMappers().values()) {
if (objectMapper.nested().isNested()) {
ObjectMapper parentObjectMapper = docMapper.findParentObjectMapper(objectMapper);
if (parentObjectMapper != null && parentObjectMapper.nested().isNested()) {
warmUp.add(parentObjectMapper.nestedTypeFilter());
}
}
}
}
}
if (hasNested) {
warmUp.add(Queries.newNonNestedFilter());
}
final Executor executor = threadPool.executor(executor());
final CountDownLatch latch = new CountDownLatch(context.searcher().reader().leaves().size() * warmUp.size());
for (final LeafReaderContext ctx : context.searcher().reader().leaves()) {
for (final Query filterToWarm : warmUp) {
executor.execute(new Runnable() {
@Override
public void run() {
try {
final long start = System.nanoTime();
getAndLoadIfNotPresent(filterToWarm, ctx);
if (indexShard.warmerService().logger().isTraceEnabled()) {
indexShard.warmerService().logger().trace("warmed bitset for [{}], took [{}]", filterToWarm, TimeValue.timeValueNanos(System.nanoTime() - start));
}
} catch (Throwable t) {
indexShard.warmerService().logger().warn("failed to load bitset for [{}]", t, filterToWarm);
} finally {
latch.countDown();
}
}
});
}
}
return new TerminationHandle() {
@Override
public void awaitTermination() throws InterruptedException {
latch.await();
}
};
}
@Override
public TerminationHandle warmTopReader(IndexShard indexShard, IndexMetaData indexMetaData, IndicesWarmer.WarmerContext context, ThreadPool threadPool) {
return TerminationHandle.NO_WAIT;
}
}
Cache<Object, Cache<Query, Value>> getLoadedFilters() {
return loadedFilters;
}
/**
* A listener interface that is executed for each onCache / onRemoval event
*/
public interface Listener {
/**
* Called for each cached bitset on the cache event.
* @param shardId the shard id the bitset was cached for. This can be <code>null</code>
* @param accountable the bitsets ram representation
*/
void onCache(ShardId shardId, Accountable accountable);
/**
* Called for each cached bitset on the removal event.
* @param shardId the shard id the bitset was cached for. This can be <code>null</code>
* @param accountable the bitsets ram representation
*/
void onRemoval(ShardId shardId, Accountable accountable);
}
}