// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.search.yql;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Set;
import com.google.common.annotations.Beta;
import com.yahoo.component.chain.dependencies.After;
import com.yahoo.component.chain.dependencies.Before;
import com.yahoo.prelude.fastsearch.FastHit;
import com.yahoo.processing.request.CompoundName;
import com.yahoo.search.Query;
import com.yahoo.search.Result;
import com.yahoo.search.Searcher;
import com.yahoo.search.result.Hit;
import com.yahoo.search.searchchain.Execution;
/**
* Remove fields which are not explicitly requested, if any field is explicitly
* requested. Disable using FieldFilter.disable=true in request.
*
* @author Steinar Knutsen
*/
@Beta
@After(MinimalQueryInserter.EXTERNAL_YQL)
@Before("com.yahoo.search.yql.FieldFiller")
public class FieldFilter extends Searcher {
public static final CompoundName FIELD_FILTER_DISABLE = new CompoundName("FieldFilter.disable");
@Override
public Result search(Query query, Execution execution) {
Result result = execution.search(query);
filter(result);
return result;
}
@Override
public void fill(Result result, String summaryClass, Execution execution) {
execution.fill(result, summaryClass);
filter(result);
}
private void filter(Result result) {
Set requestedFields;
if (result.getQuery().properties().getBoolean(FIELD_FILTER_DISABLE)) return;
if (result.getQuery().getPresentation().getSummaryFields().isEmpty()) return;
requestedFields = result.getQuery().getPresentation().getSummaryFields();
for (Iterator i = result.hits().unorderedDeepIterator(); i.hasNext();) {
Hit h = i.next();
if (h.isMeta()) continue;
for (Iterator> fields = h.fieldIterator(); fields.hasNext();) {
Entry field = fields.next();
if ( ! requestedFields.contains(field.getKey()))
fields.remove();
}
}
}
}