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* 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
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package org.elasticsearch.action.explain;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Explanation;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.RoutingMissingException;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.single.shard.TransportShardSingleOperationAction;
import org.elasticsearch.cache.recycler.PageCacheRecycler;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.routing.ShardIterator;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.BigArrays;
import org.elasticsearch.index.engine.Engine;
import org.elasticsearch.index.get.GetResult;
import org.elasticsearch.index.mapper.Uid;
import org.elasticsearch.index.mapper.internal.UidFieldMapper;
import org.elasticsearch.index.service.IndexService;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.shard.service.IndexShard;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.script.ScriptService;
import org.elasticsearch.search.internal.DefaultSearchContext;
import org.elasticsearch.search.internal.SearchContext;
import org.elasticsearch.search.internal.ShardSearchLocalRequest;
import org.elasticsearch.search.rescore.RescoreSearchContext;
import org.elasticsearch.search.rescore.Rescorer;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;
import java.io.IOException;
/**
* Explain transport action. Computes the explain on the targeted shard.
*/
// TODO: AggregatedDfs. Currently the idf can be different then when executing a normal search with explain.
public class TransportExplainAction extends TransportShardSingleOperationAction<ExplainRequest, ExplainResponse> {
private final IndicesService indicesService;
private final ScriptService scriptService;
private final PageCacheRecycler pageCacheRecycler;
private final BigArrays bigArrays;
@Inject
public TransportExplainAction(Settings settings, ThreadPool threadPool, ClusterService clusterService,
TransportService transportService, IndicesService indicesService,
ScriptService scriptService, PageCacheRecycler pageCacheRecycler,
BigArrays bigArrays, ActionFilters actionFilters) {
super(settings, ExplainAction.NAME, threadPool, clusterService, transportService, actionFilters);
this.indicesService = indicesService;
this.scriptService = scriptService;
this.pageCacheRecycler = pageCacheRecycler;
this.bigArrays = bigArrays;
}
@Override
protected void doExecute(ExplainRequest request, ActionListener<ExplainResponse> listener) {
request.nowInMillis = System.currentTimeMillis();
super.doExecute(request, listener);
}
protected String executor() {
return ThreadPool.Names.GET; // Or use Names.SEARCH?
}
@Override
protected boolean resolveIndex() {
return true;
}
@Override
protected void resolveRequest(ClusterState state, InternalRequest request) {
request.request().filteringAlias(state.metaData().filteringAliases(request.concreteIndex(), request.request().index()));
// Fail fast on the node that received the request.
if (request.request().routing() == null && state.getMetaData().routingRequired(request.concreteIndex(), request.request().type())) {
throw new RoutingMissingException(request.concreteIndex(), request.request().type(), request.request().id());
}
}
@Override
protected ExplainResponse shardOperation(ExplainRequest request, ShardId shardId) throws ElasticsearchException {
IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
IndexShard indexShard = indexService.shardSafe(shardId.id());
Term uidTerm = new Term(UidFieldMapper.NAME, Uid.createUidAsBytes(request.type(), request.id()));
Engine.GetResult result = indexShard.get(new Engine.Get(false, uidTerm));
if (!result.exists()) {
return new ExplainResponse(shardId.getIndex(), request.type(), request.id(), false);
}
SearchContext context = new DefaultSearchContext(
0, new ShardSearchLocalRequest(new String[]{request.type()}, request.nowInMillis, request.filteringAlias()),
null, result.searcher(), indexService, indexShard,
scriptService, pageCacheRecycler,
bigArrays, threadPool.estimatedTimeInMillisCounter()
);
SearchContext.setCurrent(context);
try {
context.parsedQuery(indexService.queryParserService().parseQuery(request.source()));
context.preProcess();
int topLevelDocId = result.docIdAndVersion().docId + result.docIdAndVersion().context.docBase;
Explanation explanation = context.searcher().explain(context.query(), topLevelDocId);
for (RescoreSearchContext ctx : context.rescore()) {
Rescorer rescorer = ctx.rescorer();
explanation = rescorer.explain(topLevelDocId, context, ctx, explanation);
}
if (request.fields() != null || (request.fetchSourceContext() != null && request.fetchSourceContext().fetchSource())) {
// Advantage is that we're not opening a second searcher to retrieve the _source. Also
// because we are working in the same searcher in engineGetResult we can be sure that a
// doc isn't deleted between the initial get and this call.
GetResult getResult = indexShard.getService().get(result, request.id(), request.type(), request.fields(), request.fetchSourceContext(), false);
return new ExplainResponse(shardId.getIndex(), request.type(), request.id(), true, explanation, getResult);
} else {
return new ExplainResponse(shardId.getIndex(), request.type(), request.id(), true, explanation);
}
} catch (IOException e) {
throw new ElasticsearchException("Could not explain", e);
} finally {
context.close();
SearchContext.removeCurrent();
}
}
protected ExplainRequest newRequest() {
return new ExplainRequest();
}
protected ExplainResponse newResponse() {
return new ExplainResponse();
}
@Override
protected ShardIterator shards(ClusterState state, InternalRequest request) throws ElasticsearchException {
return clusterService.operationRouting().getShards(
clusterService.state(), request.concreteIndex(), request.request().type(), request.request().id(), request.request().routing(), request.request().preference()
);
}
}