| package org.apache.lucene.search.spans; |
| |
| /** |
| * 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.index.IndexReader; |
| import org.apache.lucene.index.Term; |
| import org.apache.lucene.search.*; |
| import org.apache.lucene.search.Explanation.IDFExplanation; |
| |
| import java.io.IOException; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| /** |
| * Expert-only. Public for use by other weight implementations |
| */ |
| public class SpanWeight extends Weight { |
| protected Similarity similarity; |
| protected float value; |
| protected float idf; |
| protected float queryNorm; |
| protected float queryWeight; |
| |
| protected Set<Term> terms; |
| protected SpanQuery query; |
| private IDFExplanation idfExp; |
| |
| public SpanWeight(SpanQuery query, Searcher searcher) |
| throws IOException { |
| this.similarity = query.getSimilarity(searcher); |
| this.query = query; |
| |
| terms=new HashSet<Term>(); |
| query.extractTerms(terms); |
| |
| idfExp = similarity.idfExplain(terms, searcher); |
| idf = idfExp.getIdf(); |
| } |
| |
| @Override |
| public Query getQuery() { return query; } |
| |
| @Override |
| public float getValue() { return value; } |
| |
| @Override |
| public float sumOfSquaredWeights() throws IOException { |
| queryWeight = idf * query.getBoost(); // compute query weight |
| return queryWeight * queryWeight; // square it |
| } |
| |
| @Override |
| public void normalize(float queryNorm) { |
| this.queryNorm = queryNorm; |
| queryWeight *= queryNorm; // normalize query weight |
| value = queryWeight * idf; // idf for document |
| } |
| |
| @Override |
| public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException { |
| return new SpanScorer(query.getSpans(reader), this, similarity, reader |
| .norms(query.getField())); |
| } |
| |
| @Override |
| public Explanation explain(IndexReader reader, int doc) |
| throws IOException { |
| |
| ComplexExplanation result = new ComplexExplanation(); |
| result.setDescription("weight("+getQuery()+" in "+doc+"), product of:"); |
| String field = ((SpanQuery)getQuery()).getField(); |
| |
| Explanation idfExpl = |
| new Explanation(idf, "idf(" + field + ": " + idfExp.explain() + ")"); |
| |
| // explain query weight |
| Explanation queryExpl = new Explanation(); |
| queryExpl.setDescription("queryWeight(" + getQuery() + "), product of:"); |
| |
| Explanation boostExpl = new Explanation(getQuery().getBoost(), "boost"); |
| if (getQuery().getBoost() != 1.0f) |
| queryExpl.addDetail(boostExpl); |
| queryExpl.addDetail(idfExpl); |
| |
| Explanation queryNormExpl = new Explanation(queryNorm,"queryNorm"); |
| queryExpl.addDetail(queryNormExpl); |
| |
| queryExpl.setValue(boostExpl.getValue() * |
| idfExpl.getValue() * |
| queryNormExpl.getValue()); |
| |
| result.addDetail(queryExpl); |
| |
| // explain field weight |
| ComplexExplanation fieldExpl = new ComplexExplanation(); |
| fieldExpl.setDescription("fieldWeight("+field+":"+query.toString(field)+ |
| " in "+doc+"), product of:"); |
| |
| Explanation tfExpl = ((SpanScorer)scorer(reader, true, false)).explain(doc); |
| fieldExpl.addDetail(tfExpl); |
| fieldExpl.addDetail(idfExpl); |
| |
| Explanation fieldNormExpl = new Explanation(); |
| byte[] fieldNorms = reader.norms(field); |
| float fieldNorm = |
| fieldNorms!=null ? Similarity.decodeNorm(fieldNorms[doc]) : 1.0f; |
| fieldNormExpl.setValue(fieldNorm); |
| fieldNormExpl.setDescription("fieldNorm(field="+field+", doc="+doc+")"); |
| fieldExpl.addDetail(fieldNormExpl); |
| |
| fieldExpl.setMatch(Boolean.valueOf(tfExpl.isMatch())); |
| fieldExpl.setValue(tfExpl.getValue() * |
| idfExpl.getValue() * |
| fieldNormExpl.getValue()); |
| |
| result.addDetail(fieldExpl); |
| result.setMatch(fieldExpl.getMatch()); |
| |
| // combine them |
| result.setValue(queryExpl.getValue() * fieldExpl.getValue()); |
| |
| if (queryExpl.getValue() == 1.0f) |
| return fieldExpl; |
| |
| return result; |
| } |
| } |