package org.apache.solr.spelling.suggest;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*/
import java.text.ParseException;
import java.util.HashSet;
import java.util.Set;
import org.apache.lucene.expressions.Expression;
import org.apache.lucene.expressions.SimpleBindings;
import org.apache.lucene.expressions.js.JavascriptCompiler;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.spell.Dictionary;
import org.apache.lucene.search.suggest.DocumentValueSourceDictionary;
import org.apache.solr.core.SolrCore;
import org.apache.solr.schema.DoubleField;
import org.apache.solr.schema.FieldType;
import org.apache.solr.schema.FloatField;
import org.apache.solr.schema.IntField;
import org.apache.solr.schema.LongField;
import org.apache.solr.schema.TrieDoubleField;
import org.apache.solr.schema.TrieFloatField;
import org.apache.solr.schema.TrieIntField;
import org.apache.solr.schema.TrieLongField;
import org.apache.solr.search.SolrIndexSearcher;
/**
* Factory for {@link org.apache.lucene.search.suggest.DocumentValueSourceDictionary}
*/
public class DocumentExpressionDictionaryFactory extends DictionaryFactory {
/** Label for defining field to use for terms */
public static final String FIELD = "field";
/** Label for defining payloadField to use for terms (optional) */
public static final String PAYLOAD_FIELD = "payloadField";
/** Label for defining expression to evaluate the weight for the terms */
public static final String WEIGHT_EXPRESSION = "weightExpression";
/** Label used to define the name of the
* sortField used in the {@link #WEIGHT_EXPRESSION} */
public static final String SORT_FIELD = "sortField";
@Override
public Dictionary create(SolrCore core, SolrIndexSearcher searcher) {
if(params == null) {
// should not happen; implies setParams was not called
throw new IllegalStateException("Value of params not set");
}
String field = (String) params.get(FIELD);
String payloadField = (String) params.get(PAYLOAD_FIELD);
String weightExpression = (String) params.get(WEIGHT_EXPRESSION);
Set<SortField> sortFields = new HashSet<>();
if (field == null) {
throw new IllegalArgumentException(FIELD + " is a mandatory parameter");
}
if (weightExpression == null) {
throw new IllegalArgumentException(WEIGHT_EXPRESSION + " is a mandatory parameter");
}
for(int i = 0; i < params.size(); i++) {
if (params.getName(i).equals(SORT_FIELD)) {
String sortFieldName = (String) params.getVal(i);
SortField.Type sortFieldType = getSortFieldType(core, sortFieldName);
if (sortFieldType == null) {
throw new IllegalArgumentException(sortFieldName + " could not be mapped to any appropriate type"
+ " [long, int, float, double]");
}
SortField sortField = new SortField(sortFieldName, sortFieldType);
sortFields.add(sortField);
}
}
return new DocumentValueSourceDictionary(searcher.getIndexReader(), field, fromExpression(weightExpression,
sortFields), payloadField);
}
public ValueSource fromExpression(String weightExpression, Set<SortField> sortFields) {
Expression expression = null;
try {
expression = JavascriptCompiler.compile(weightExpression);
} catch (ParseException e) {
throw new RuntimeException();
}
SimpleBindings bindings = new SimpleBindings();
for (SortField sortField : sortFields) {
bindings.add(sortField);
}
return expression.getValueSource(bindings);
}
private SortField.Type getSortFieldType(SolrCore core, String sortFieldName) {
SortField.Type type = null;
String fieldTypeName = core.getLatestSchema().getField(sortFieldName).getType().getTypeName();
FieldType ft = core.getLatestSchema().getFieldTypes().get(fieldTypeName);
if (ft instanceof FloatField || ft instanceof TrieFloatField) {
type = SortField.Type.FLOAT;
} else if (ft instanceof IntField || ft instanceof TrieIntField) {
type = SortField.Type.INT;
} else if (ft instanceof LongField || ft instanceof TrieLongField) {
type = SortField.Type.LONG;
} else if (ft instanceof DoubleField || ft instanceof TrieDoubleField) {
type = SortField.Type.DOUBLE;
}
return type;
}
}