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();
}
}