+++ /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.util.ArrayUtil;
-import java.io.IOException;
-import java.util.Collection;
-import java.util.Comparator;
-
-/** Scorer for conjunctions, sets of queries, all of which are required. */
-class ConjunctionScorer extends Scorer {
-
- private final Scorer[] scorers;
- private final float coord;
- private int lastDoc = -1;
-
- public ConjunctionScorer(Weight weight, float coord, Collection<Scorer> scorers) throws IOException {
- this(weight, coord, scorers.toArray(new Scorer[scorers.size()]));
- }
-
- public ConjunctionScorer(Weight weight, float coord, Scorer... scorers) throws IOException {
- super(weight);
- this.scorers = scorers;
- this.coord = coord;
-
- for (int i = 0; i < scorers.length; i++) {
- if (scorers[i].nextDoc() == NO_MORE_DOCS) {
- // If even one of the sub-scorers does not have any documents, this
- // scorer should not attempt to do any more work.
- lastDoc = NO_MORE_DOCS;
- return;
- }
- }
-
- // Sort the array the first time...
- // We don't need to sort the array in any future calls because we know
- // it will already start off sorted (all scorers on same doc).
-
- // Note that this comparator is not consistent with equals!
- // Also we use mergeSort here to be stable (so order of Scoreres that
- // match on first document keeps preserved):
- ArrayUtil.mergeSort(scorers, new Comparator<Scorer>() { // sort the array
- public int compare(Scorer o1, Scorer o2) {
- return o1.docID() - o2.docID();
- }
- });
-
- // NOTE: doNext() must be called before the re-sorting of the array later on.
- // The reason is this: assume there are 5 scorers, whose first docs are 1,
- // 2, 3, 5, 5 respectively. Sorting (above) leaves the array as is. Calling
- // doNext() here advances all the first scorers to 5 (or a larger doc ID
- // they all agree on).
- // However, if we re-sort before doNext() is called, the order will be 5, 3,
- // 2, 1, 5 and then doNext() will stop immediately, since the first scorer's
- // docs equals the last one. So the invariant that after calling doNext()
- // all scorers are on the same doc ID is broken.
- if (doNext() == NO_MORE_DOCS) {
- // The scorers did not agree on any document.
- lastDoc = NO_MORE_DOCS;
- return;
- }
-
- // If first-time skip distance is any predictor of
- // scorer sparseness, then we should always try to skip first on
- // those scorers.
- // Keep last scorer in it's last place (it will be the first
- // to be skipped on), but reverse all of the others so that
- // they will be skipped on in order of original high skip.
- int end = scorers.length - 1;
- int max = end >> 1;
- for (int i = 0; i < max; i++) {
- Scorer tmp = scorers[i];
- int idx = end - i - 1;
- scorers[i] = scorers[idx];
- scorers[idx] = tmp;
- }
- }
-
- private int doNext() throws IOException {
- int first = 0;
- int doc = scorers[scorers.length - 1].docID();
- Scorer firstScorer;
- while ((firstScorer = scorers[first]).docID() < doc) {
- doc = firstScorer.advance(doc);
- first = first == scorers.length - 1 ? 0 : first + 1;
- }
- return doc;
- }
-
- @Override
- public int advance(int target) throws IOException {
- if (lastDoc == NO_MORE_DOCS) {
- return lastDoc;
- } else if (scorers[(scorers.length - 1)].docID() < target) {
- scorers[(scorers.length - 1)].advance(target);
- }
- return lastDoc = doNext();
- }
-
- @Override
- public int docID() {
- return lastDoc;
- }
-
- @Override
- public int nextDoc() throws IOException {
- if (lastDoc == NO_MORE_DOCS) {
- return lastDoc;
- } else if (lastDoc == -1) {
- return lastDoc = scorers[scorers.length - 1].docID();
- }
- scorers[(scorers.length - 1)].nextDoc();
- return lastDoc = doNext();
- }
-
- @Override
- public float score() throws IOException {
- float sum = 0.0f;
- for (int i = 0; i < scorers.length; i++) {
- sum += scorers[i].score();
- }
- return sum * coord;
- }
-}
fnp / pylucene.git / blobdiff