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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 org.apache.logging.log4j.message.ParameterizedMessage;
import org.apache.logging.log4j.util.Supplier;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexReaderContext;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.ReaderUtil;
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.common.cache.Cache;
import org.elasticsearch.common.cache.CacheBuilder;
import org.elasticsearch.common.cache.RemovalListener;
import org.elasticsearch.common.cache.RemovalNotification;
import org.elasticsearch.common.lucene.search.Queries;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Setting.Property;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.AbstractIndexComponent;
import org.elasticsearch.index.IndexSettings;
import org.elasticsearch.index.IndexWarmer;
import org.elasticsearch.index.IndexWarmer.TerminationHandle;
import org.elasticsearch.index.engine.Engine;
import org.elasticsearch.index.mapper.DocumentMapper;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.mapper.ObjectMapper;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.shard.ShardUtils;
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.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
/**
* 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 final class BitsetFilterCache extends AbstractIndexComponent implements IndexReader.ClosedListener, RemovalListener<IndexReader.CacheKey, Cache<Query, BitsetFilterCache.Value>>, Closeable {
public static final Setting<Boolean> INDEX_LOAD_RANDOM_ACCESS_FILTERS_EAGERLY_SETTING =
Setting.boolSetting("index.load_fixed_bitset_filters_eagerly", true, Property.IndexScope);
private final boolean loadRandomAccessFiltersEagerly;
private final Cache<IndexReader.CacheKey, Cache<Query, Value>> loadedFilters;
private final Listener listener;
public BitsetFilterCache(IndexSettings indexSettings, Listener listener) {
super(indexSettings);
if (listener == null) {
throw new IllegalArgumentException("listener must not be null");
}
this.loadRandomAccessFiltersEagerly = this.indexSettings.getValue(INDEX_LOAD_RANDOM_ACCESS_FILTERS_EAGERLY_SETTING);
this.loadedFilters = CacheBuilder.<IndexReader.CacheKey, Cache<Query, Value>>builder().removalListener(this).build();
this.listener = listener;
}
public IndexWarmer.Listener createListener(ThreadPool threadPool) {
return new BitSetProducerWarmer(threadPool);
}
public BitSetProducer getBitSetProducer(Query query) {
return new QueryWrapperBitSetProducer(query);
}
@Override
public void onClose(IndexReader.CacheKey ownerCoreCacheKey) {
loadedFilters.invalidate(ownerCoreCacheKey);
}
@Override
public void close() {
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 IndexReader.CacheHelper cacheHelper = context.reader().getCoreCacheHelper();
if (cacheHelper == null) {
throw new IllegalArgumentException("Reader " + context.reader() + " does not support caching");
}
final IndexReader.CacheKey coreCacheReader = cacheHelper.getKey();
final ShardId shardId = ShardUtils.extractShardId(context.reader());
if (indexSettings.getIndex().equals(shardId.getIndex()) == false) {
// insanity
throw new IllegalStateException("Trying to load bit set for index " + shardId.getIndex()
+ " with cache of index " + indexSettings.getIndex());
}
Cache<Query, Value> filterToFbs = loadedFilters.computeIfAbsent(coreCacheReader, key -> {
cacheHelper.addClosedListener(BitsetFilterCache.this);
return CacheBuilder.<Query, Value>builder().build();
});
return filterToFbs.computeIfAbsent(query, key -> {
final IndexReaderContext topLevelContext = ReaderUtil.getTopLevelContext(context);
final IndexSearcher searcher = new IndexSearcher(topLevelContext);
searcher.setQueryCache(null);
final Weight weight = searcher.createNormalizedWeight(query, false);
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<IndexReader.CacheKey, Cache<Query, Value>> notification) {
if (notification.getKey() == null) {
return;
}
Cache<Query, Value> valueCache = notification.getValue();
if (valueCache == null) {
return;
}
for (Value value : valueCache.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 implements IndexWarmer.Listener {
private final Executor executor;
BitSetProducerWarmer(ThreadPool threadPool) {
this.executor = threadPool.executor(ThreadPool.Names.WARMER);
}
@Override
public IndexWarmer.TerminationHandle warmReader(final IndexShard indexShard, final Engine.Searcher searcher) {
if (indexSettings.getIndex().equals(indexShard.indexSettings().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 CountDownLatch latch = new CountDownLatch(searcher.reader().leaves().size() * warmUp.size());
for (final LeafReaderContext ctx : searcher.reader().leaves()) {
for (final Query filterToWarm : warmUp) {
executor.execute(() -> {
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 (Exception e) {
indexShard.warmerService().logger().warn((Supplier<?>) () -> new ParameterizedMessage("failed to load bitset for [{}]", filterToWarm), e);
} finally {
latch.countDown();
}
});
}
}
return () -> latch.await();
}
}
Cache<IndexReader.CacheKey, 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);
}
}