protected ExplainResponse shardOperation(ExplainRequest request, int shardId)
throws ElasticSearchException {
IndexService indexService = indicesService.indexService(request.index());
IndexShard indexShard = indexService.shardSafe(shardId);
Term uidTerm =
new Term(UidFieldMapper.NAME, Uid.createUidAsBytes(request.getType(), request.getId()));
Engine.GetResult result = indexShard.get(new Engine.Get(false, uidTerm));
if (!result.exists()) {
return new ExplainResponse(false);
}
SearchContext context =
new SearchContext(
0,
new ShardSearchRequest()
.types(new String[] {request.getType()})
.filteringAliases(request.getFilteringAlias()),
null,
result.searcher(),
indexService,
indexShard,
scriptService);
SearchContext.setCurrent(context);
try {
context.parsedQuery(parseQuery(request, indexService));
context.preProcess();
int topLevelDocId = result.docIdAndVersion().docId + result.docIdAndVersion().reader.docBase;
Explanation explanation;
if (context.rescore() != null) {
RescoreSearchContext ctx = context.rescore();
Rescorer rescorer = ctx.rescorer();
explanation = rescorer.explain(topLevelDocId, context, ctx);
} else {
explanation = context.searcher().explain(context.query(), topLevelDocId);
}
if (request.getFields() != null) {
if (request.getFields().length == 1 && "_source".equals(request.getFields()[0])) {
request.setFields(null); // Load the _source field
}
// 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.getId(), request.getType(), request.getFields());
return new ExplainResponse(true, explanation, getResult);
} else {
return new ExplainResponse(true, explanation);
}
} catch (IOException e) {
throw new ElasticSearchException("Could not explain", e);
} finally {
context.release();
SearchContext.removeCurrent();
}
}
protected ShardIterator shards(ClusterState state, ExplainRequest request)
throws ElasticSearchException {
return clusterService
.operationRouting()
.getShards(
clusterService.state(),
request.index(),
request.getType(),
request.getId(),
request.getRouting(),
request.getPreference());
}
@Override
protected void resolveRequest(ClusterState state, ExplainRequest request) {
String concreteIndex = state.metaData().concreteIndex(request.index());
request.setFilteringAlias(state.metaData().filteringAliases(concreteIndex, request.index()));
request.index(state.metaData().concreteIndex(request.index()));
}
protected ClusterBlockException checkRequestBlock(ClusterState state, ExplainRequest request) {
return state.blocks().indexBlockedException(ClusterBlockLevel.READ, request.index());
}