package org.apache.solr.spelling.suggest.fst;
/**
* 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 org.apache.lucene.search.suggest.Lookup;
import org.apache.lucene.search.suggest.fst.FSTLookup;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.spelling.suggest.LookupFactory;
/**
* Factory for {@link FSTLookup}
*/
public class FSTLookupFactory extends LookupFactory {
/**
* The number of separate buckets for weights (discretization). The more buckets,
* the more fine-grained term weights (priorities) can be assigned. The speed of lookup
* will not decrease for prefixes which have highly-weighted completions (because these
* are filled-in first), but will decrease significantly for low-weighted terms (but
* these should be infrequent, so it is all right).
*
* <p>The number of buckets must be within [1, 255] range.
*/
public static final String WEIGHT_BUCKETS = "weightBuckets";
/**
* If <code>true</code>, exact suggestions are returned first, even if they are prefixes
* of other strings in the automaton (possibly with larger weights).
*/
public static final String EXACT_MATCH_FIRST = "exactMatchFirst";
@Override
public Lookup create(NamedList params, SolrCore core) {
int buckets = params.get(WEIGHT_BUCKETS) != null
? Integer.parseInt(params.get(WEIGHT_BUCKETS).toString())
: 10;
boolean exactMatchFirst = params.get(EXACT_MATCH_FIRST) != null
? Boolean.valueOf(params.get(EXACT_MATCH_FIRST).toString())
: true;
return new FSTLookup(buckets, exactMatchFirst);
}
}