+++ /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 java.io.IOException;
-import java.util.ArrayList;
-
-import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.Term;
-
-class ConstantScoreAutoRewrite extends TermCollectingRewrite<BooleanQuery> {
-
- // Defaults derived from rough tests with a 20.0 million
- // doc Wikipedia index. With more than 350 terms in the
- // query, the filter method is fastest:
- public static int DEFAULT_TERM_COUNT_CUTOFF = 350;
-
- // If the query will hit more than 1 in 1000 of the docs
- // in the index (0.1%), the filter method is fastest:
- public static double DEFAULT_DOC_COUNT_PERCENT = 0.1;
-
- private int termCountCutoff = DEFAULT_TERM_COUNT_CUTOFF;
- private double docCountPercent = DEFAULT_DOC_COUNT_PERCENT;
-
- /** If the number of terms in this query is equal to or
- * larger than this setting then {@link
- * #CONSTANT_SCORE_FILTER_REWRITE} is used. */
- public void setTermCountCutoff(int count) {
- termCountCutoff = count;
- }
-
- /** @see #setTermCountCutoff */
- public int getTermCountCutoff() {
- return termCountCutoff;
- }
-
- /** If the number of documents to be visited in the
- * postings exceeds this specified percentage of the
- * maxDoc() for the index, then {@link
- * #CONSTANT_SCORE_FILTER_REWRITE} is used.
- * @param percent 0.0 to 100.0 */
- public void setDocCountPercent(double percent) {
- docCountPercent = percent;
- }
-
- /** @see #setDocCountPercent */
- public double getDocCountPercent() {
- return docCountPercent;
- }
-
- @Override
- protected BooleanQuery getTopLevelQuery() {
- return new BooleanQuery(true);
- }
-
- @Override
- protected void addClause(BooleanQuery topLevel, Term term, float boost /*ignored*/) {
- topLevel.add(new TermQuery(term), BooleanClause.Occur.SHOULD);
- }
-
- @Override
- public Query rewrite(final IndexReader reader, final MultiTermQuery query) throws IOException {
-
- // Get the enum and start visiting terms. If we
- // exhaust the enum before hitting either of the
- // cutoffs, we use ConstantBooleanQueryRewrite; else,
- // ConstantFilterRewrite:
- final int docCountCutoff = (int) ((docCountPercent / 100.) * reader.maxDoc());
- final int termCountLimit = Math.min(BooleanQuery.getMaxClauseCount(), termCountCutoff);
-
- final CutOffTermCollector col = new CutOffTermCollector(reader, docCountCutoff, termCountLimit);
- collectTerms(reader, query, col);
-
- if (col.hasCutOff) {
- return MultiTermQuery.CONSTANT_SCORE_FILTER_REWRITE.rewrite(reader, query);
- } else {
- final Query result;
- if (col.pendingTerms.isEmpty()) {
- result = getTopLevelQuery();
- } else {
- BooleanQuery bq = getTopLevelQuery();
- for(Term term : col.pendingTerms) {
- addClause(bq, term, 1.0f);
- }
- // Strip scores
- result = new ConstantScoreQuery(bq);
- result.setBoost(query.getBoost());
- }
- query.incTotalNumberOfTerms(col.pendingTerms.size());
- return result;
- }
- }
-
- private static final class CutOffTermCollector implements TermCollector {
- CutOffTermCollector(IndexReader reader, int docCountCutoff, int termCountLimit) {
- this.reader = reader;
- this.docCountCutoff = docCountCutoff;
- this.termCountLimit = termCountLimit;
- }
-
- public boolean collect(Term t, float boost) throws IOException {
- pendingTerms.add(t);
- // Loading the TermInfo from the terms dict here
- // should not be costly, because 1) the
- // query/filter will load the TermInfo when it
- // runs, and 2) the terms dict has a cache:
- docVisitCount += reader.docFreq(t);
- if (pendingTerms.size() >= termCountLimit || docVisitCount >= docCountCutoff) {
- hasCutOff = true;
- return false;
- }
- return true;
- }
-
- int docVisitCount = 0;
- boolean hasCutOff = false;
-
- final IndexReader reader;
- final int docCountCutoff, termCountLimit;
- final ArrayList<Term> pendingTerms = new ArrayList<Term>();
- }
-
- @Override
- public int hashCode() {
- final int prime = 1279;
- return (int) (prime * termCountCutoff + Double.doubleToLongBits(docCountPercent));
- }
-
- @Override
- public boolean equals(Object obj) {
- if (this == obj)
- return true;
- if (obj == null)
- return false;
- if (getClass() != obj.getClass())
- return false;
-
- ConstantScoreAutoRewrite other = (ConstantScoreAutoRewrite) obj;
- if (other.termCountCutoff != termCountCutoff) {
- return false;
- }
-
- if (Double.doubleToLongBits(other.docCountPercent) != Double.doubleToLongBits(docCountPercent)) {
- return false;
- }
-
- return true;
- }
-}
fnp / pylucene.git / blobdiff