+++ /dev/null
-package org.apache.lucene.search;
-
-/**
- * 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.util.ToStringUtils;
-
-import java.io.IOException;
-import java.util.Set;
-
-
-/**
- * A query that applies a filter to the results of another query.
- *
- * <p>Note: the bits are retrieved from the filter each time this
- * query is used in a search - use a CachingWrapperFilter to avoid
- * regenerating the bits every time.
- *
- * <p>Created: Apr 20, 2004 8:58:29 AM
- *
- * @since 1.4
- * @see CachingWrapperFilter
- */
-public class FilteredQuery
-extends Query {
-
- Query query;
- Filter filter;
-
- /**
- * Constructs a new query which applies a filter to the results of the original query.
- * Filter.getDocIdSet() will be called every time this query is used in a search.
- * @param query Query to be filtered, cannot be <code>null</code>.
- * @param filter Filter to apply to query results, cannot be <code>null</code>.
- */
- public FilteredQuery (Query query, Filter filter) {
- this.query = query;
- this.filter = filter;
- }
-
- /**
- * Returns a Weight that applies the filter to the enclosed query's Weight.
- * This is accomplished by overriding the Scorer returned by the Weight.
- */
- @Override
- public Weight createWeight(final Searcher searcher) throws IOException {
- final Weight weight = query.createWeight (searcher);
- final Similarity similarity = query.getSimilarity(searcher);
- return new Weight() {
- private float value;
-
- // pass these methods through to enclosed query's weight
- @Override
- public float getValue() { return value; }
-
- @Override
- public float sumOfSquaredWeights() throws IOException {
- return weight.sumOfSquaredWeights() * getBoost() * getBoost();
- }
-
- @Override
- public void normalize (float v) {
- weight.normalize(v);
- value = weight.getValue() * getBoost();
- }
-
- @Override
- public Explanation explain (IndexReader ir, int i) throws IOException {
- Explanation inner = weight.explain (ir, i);
- if (getBoost()!=1) {
- Explanation preBoost = inner;
- inner = new Explanation(inner.getValue()*getBoost(),"product of:");
- inner.addDetail(new Explanation(getBoost(),"boost"));
- inner.addDetail(preBoost);
- }
- Filter f = FilteredQuery.this.filter;
- DocIdSet docIdSet = f.getDocIdSet(ir);
- DocIdSetIterator docIdSetIterator = docIdSet == null ? DocIdSet.EMPTY_DOCIDSET.iterator() : docIdSet.iterator();
- if (docIdSetIterator == null) {
- docIdSetIterator = DocIdSet.EMPTY_DOCIDSET.iterator();
- }
- if (docIdSetIterator.advance(i) == i) {
- return inner;
- } else {
- Explanation result = new Explanation
- (0.0f, "failure to match filter: " + f.toString());
- result.addDetail(inner);
- return result;
- }
- }
-
- // return this query
- @Override
- public Query getQuery() { return FilteredQuery.this; }
-
- // return a filtering scorer
- @Override
- public Scorer scorer(IndexReader indexReader, boolean scoreDocsInOrder, boolean topScorer)
- throws IOException {
- final Scorer scorer = weight.scorer(indexReader, true, false);
- if (scorer == null) {
- return null;
- }
- DocIdSet docIdSet = filter.getDocIdSet(indexReader);
- if (docIdSet == null) {
- return null;
- }
- final DocIdSetIterator docIdSetIterator = docIdSet.iterator();
- if (docIdSetIterator == null) {
- return null;
- }
-
- return new Scorer(similarity, this) {
-
- private int doc = -1;
-
- private int advanceToCommon(int scorerDoc, int disiDoc) throws IOException {
- while (scorerDoc != disiDoc) {
- if (scorerDoc < disiDoc) {
- scorerDoc = scorer.advance(disiDoc);
- } else {
- disiDoc = docIdSetIterator.advance(scorerDoc);
- }
- }
- return scorerDoc;
- }
-
- @Override
- public int nextDoc() throws IOException {
- int scorerDoc, disiDoc;
- return doc = (disiDoc = docIdSetIterator.nextDoc()) != NO_MORE_DOCS
- && (scorerDoc = scorer.nextDoc()) != NO_MORE_DOCS
- && advanceToCommon(scorerDoc, disiDoc) != NO_MORE_DOCS ? scorer.docID() : NO_MORE_DOCS;
- }
-
- @Override
- public int docID() { return doc; }
-
- @Override
- public int advance(int target) throws IOException {
- int disiDoc, scorerDoc;
- return doc = (disiDoc = docIdSetIterator.advance(target)) != NO_MORE_DOCS
- && (scorerDoc = scorer.advance(disiDoc)) != NO_MORE_DOCS
- && advanceToCommon(scorerDoc, disiDoc) != NO_MORE_DOCS ? scorer.docID() : NO_MORE_DOCS;
- }
-
- @Override
- public float score() throws IOException { return getBoost() * scorer.score(); }
- };
- }
- };
- }
-
- /** Rewrites the wrapped query. */
- @Override
- public Query rewrite(IndexReader reader) throws IOException {
- Query rewritten = query.rewrite(reader);
- if (rewritten != query) {
- FilteredQuery clone = (FilteredQuery)this.clone();
- clone.query = rewritten;
- return clone;
- } else {
- return this;
- }
- }
-
- public Query getQuery() {
- return query;
- }
-
- public Filter getFilter() {
- return filter;
- }
-
- // inherit javadoc
- @Override
- public void extractTerms(Set<Term> terms) {
- getQuery().extractTerms(terms);
- }
-
- /** Prints a user-readable version of this query. */
- @Override
- public String toString (String s) {
- StringBuilder buffer = new StringBuilder();
- buffer.append("filtered(");
- buffer.append(query.toString(s));
- buffer.append(")->");
- buffer.append(filter);
- buffer.append(ToStringUtils.boost(getBoost()));
- return buffer.toString();
- }
-
- /** Returns true iff <code>o</code> is equal to this. */
- @Override
- public boolean equals(Object o) {
- if (o instanceof FilteredQuery) {
- FilteredQuery fq = (FilteredQuery) o;
- return (query.equals(fq.query) && filter.equals(fq.filter) && getBoost()==fq.getBoost());
- }
- return false;
- }
-
- /** Returns a hash code value for this object. */
- @Override
- public int hashCode() {
- return query.hashCode() ^ filter.hashCode() + Float.floatToRawIntBits(getBoost());
- }
-}
fnp / pylucene.git / blobdiff