+++ /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.util.List;
-import java.io.IOException;
-
-import org.apache.lucene.util.ScorerDocQueue;
-
-/** A Scorer for OR like queries, counterpart of <code>ConjunctionScorer</code>.
- * This Scorer implements {@link Scorer#skipTo(int)} and uses skipTo() on the given Scorers.
- */
-class DisjunctionSumScorer extends Scorer {
- /** The number of subscorers. */
- private final int nrScorers;
-
- /** The subscorers. */
- protected final List<Scorer> subScorers;
-
- /** The minimum number of scorers that should match. */
- private final int minimumNrMatchers;
-
- /** The scorerDocQueue contains all subscorers ordered by their current doc(),
- * with the minimum at the top.
- * <br>The scorerDocQueue is initialized the first time next() or skipTo() is called.
- * <br>An exhausted scorer is immediately removed from the scorerDocQueue.
- * <br>If less than the minimumNrMatchers scorers
- * remain in the scorerDocQueue next() and skipTo() return false.
- * <p>
- * After each to call to next() or skipTo()
- * <code>currentSumScore</code> is the total score of the current matching doc,
- * <code>nrMatchers</code> is the number of matching scorers,
- * and all scorers are after the matching doc, or are exhausted.
- */
- private ScorerDocQueue scorerDocQueue;
-
- /** The document number of the current match. */
- private int currentDoc = -1;
-
- /** The number of subscorers that provide the current match. */
- protected int nrMatchers = -1;
-
- private float currentScore = Float.NaN;
-
- /** Construct a <code>DisjunctionScorer</code>.
- * @param weight The weight to be used.
- * @param subScorers A collection of at least two subscorers.
- * @param minimumNrMatchers The positive minimum number of subscorers that should
- * match to match this query.
- * <br>When <code>minimumNrMatchers</code> is bigger than
- * the number of <code>subScorers</code>,
- * no matches will be produced.
- * <br>When minimumNrMatchers equals the number of subScorers,
- * it more efficient to use <code>ConjunctionScorer</code>.
- */
- public DisjunctionSumScorer(Weight weight, List<Scorer> subScorers, int minimumNrMatchers) throws IOException {
- super(weight);
-
- nrScorers = subScorers.size();
-
- if (minimumNrMatchers <= 0) {
- throw new IllegalArgumentException("Minimum nr of matchers must be positive");
- }
- if (nrScorers <= 1) {
- throw new IllegalArgumentException("There must be at least 2 subScorers");
- }
-
- this.minimumNrMatchers = minimumNrMatchers;
- this.subScorers = subScorers;
-
- initScorerDocQueue();
- }
-
- /** Construct a <code>DisjunctionScorer</code>, using one as the minimum number
- * of matching subscorers.
- */
- public DisjunctionSumScorer(Weight weight, List<Scorer> subScorers) throws IOException {
- this(weight, subScorers, 1);
- }
-
- /** Called the first time next() or skipTo() is called to
- * initialize <code>scorerDocQueue</code>.
- */
- private void initScorerDocQueue() throws IOException {
- scorerDocQueue = new ScorerDocQueue(nrScorers);
- for (Scorer se : subScorers) {
- if (se.nextDoc() != NO_MORE_DOCS) {
- scorerDocQueue.insert(se);
- }
- }
- }
-
- /** Scores and collects all matching documents.
- * @param collector The collector to which all matching documents are passed through.
- */
- @Override
- public void score(Collector collector) throws IOException {
- collector.setScorer(this);
- while (nextDoc() != NO_MORE_DOCS) {
- collector.collect(currentDoc);
- }
- }
-
- /** Expert: Collects matching documents in a range. Hook for optimization.
- * Note that {@link #next()} must be called once before this method is called
- * for the first time.
- * @param collector The collector to which all matching documents are passed through.
- * @param max Do not score documents past this.
- * @return true if more matching documents may remain.
- */
- @Override
- protected boolean score(Collector collector, int max, int firstDocID) throws IOException {
- // firstDocID is ignored since nextDoc() sets 'currentDoc'
- collector.setScorer(this);
- while (currentDoc < max) {
- collector.collect(currentDoc);
- if (nextDoc() == NO_MORE_DOCS) {
- return false;
- }
- }
- return true;
- }
-
- @Override
- public int nextDoc() throws IOException {
- if (scorerDocQueue.size() < minimumNrMatchers || !advanceAfterCurrent()) {
- currentDoc = NO_MORE_DOCS;
- }
- return currentDoc;
- }
-
- /** Advance all subscorers after the current document determined by the
- * top of the <code>scorerDocQueue</code>.
- * Repeat until at least the minimum number of subscorers match on the same
- * document and all subscorers are after that document or are exhausted.
- * <br>On entry the <code>scorerDocQueue</code> has at least <code>minimumNrMatchers</code>
- * available. At least the scorer with the minimum document number will be advanced.
- * @return true iff there is a match.
- * <br>In case there is a match, </code>currentDoc</code>, </code>currentSumScore</code>,
- * and </code>nrMatchers</code> describe the match.
- *
- * TODO: Investigate whether it is possible to use skipTo() when
- * the minimum number of matchers is bigger than one, ie. try and use the
- * character of ConjunctionScorer for the minimum number of matchers.
- * Also delay calling score() on the sub scorers until the minimum number of
- * matchers is reached.
- * <br>For this, a Scorer array with minimumNrMatchers elements might
- * hold Scorers at currentDoc that are temporarily popped from scorerQueue.
- */
- protected boolean advanceAfterCurrent() throws IOException {
- do { // repeat until minimum nr of matchers
- currentDoc = scorerDocQueue.topDoc();
- currentScore = scorerDocQueue.topScore();
- nrMatchers = 1;
- do { // Until all subscorers are after currentDoc
- if (!scorerDocQueue.topNextAndAdjustElsePop()) {
- if (scorerDocQueue.size() == 0) {
- break; // nothing more to advance, check for last match.
- }
- }
- if (scorerDocQueue.topDoc() != currentDoc) {
- break; // All remaining subscorers are after currentDoc.
- }
- currentScore += scorerDocQueue.topScore();
- nrMatchers++;
- } while (true);
-
- if (nrMatchers >= minimumNrMatchers) {
- return true;
- } else if (scorerDocQueue.size() < minimumNrMatchers) {
- return false;
- }
- } while (true);
- }
-
- /** Returns the score of the current document matching the query.
- * Initially invalid, until {@link #nextDoc()} is called the first time.
- */
- @Override
- public float score() throws IOException { return currentScore; }
-
- @Override
- public int docID() {
- return currentDoc;
- }
-
- /** Returns the number of subscorers matching the current document.
- * Initially invalid, until {@link #nextDoc()} is called the first time.
- */
- public int nrMatchers() {
- return nrMatchers;
- }
-
- /**
- * Advances to the first match beyond the current whose document number is
- * greater than or equal to a given target. <br>
- * The implementation uses the skipTo() method on the subscorers.
- *
- * @param target
- * The target document number.
- * @return the document whose number is greater than or equal to the given
- * target, or -1 if none exist.
- */
- @Override
- public int advance(int target) throws IOException {
- if (scorerDocQueue.size() < minimumNrMatchers) {
- return currentDoc = NO_MORE_DOCS;
- }
- if (target <= currentDoc) {
- return currentDoc;
- }
- do {
- if (scorerDocQueue.topDoc() >= target) {
- return advanceAfterCurrent() ? currentDoc : (currentDoc = NO_MORE_DOCS);
- } else if (!scorerDocQueue.topSkipToAndAdjustElsePop(target)) {
- if (scorerDocQueue.size() < minimumNrMatchers) {
- return currentDoc = NO_MORE_DOCS;
- }
- }
- } while (true);
- }
-}
fnp / pylucene.git / blobdiff