+++ /dev/null
-package org.apache.lucene.search.grouping;
-
-/*
- * 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.search.Collector;
-import org.apache.lucene.util.FixedBitSet;
-
-import java.io.IOException;
-import java.util.Collection;
-
-/**
- * This collector specializes in collecting the most relevant document (group head) for each group that match the query.
- *
- * @lucene.experimental
- */
-public abstract class AbstractAllGroupHeadsCollector<GH extends AbstractAllGroupHeadsCollector.GroupHead> extends Collector {
-
- protected final int[] reversed;
- protected final int compIDXEnd;
- protected final TemporalResult temporalResult;
-
- protected AbstractAllGroupHeadsCollector(int numberOfSorts) {
- this.reversed = new int[numberOfSorts];
- this.compIDXEnd = numberOfSorts - 1;
- temporalResult = new TemporalResult();
- }
-
- /**
- * @param maxDoc The maxDoc of the top level {@link IndexReader}.
- * @return an {@link FixedBitSet} containing all group heads.
- */
- public FixedBitSet retrieveGroupHeads(int maxDoc) {
- FixedBitSet bitSet = new FixedBitSet(maxDoc);
-
- Collection<GH> groupHeads = getCollectedGroupHeads();
- for (GroupHead groupHead : groupHeads) {
- bitSet.set(groupHead.doc);
- }
-
- return bitSet;
- }
-
- /**
- * @return an int array containing all group heads. The size of the array is equal to number of collected unique groups.
- */
- public int[] retrieveGroupHeads() {
- Collection<GH> groupHeads = getCollectedGroupHeads();
- int[] docHeads = new int[groupHeads.size()];
-
- int i = 0;
- for (GroupHead groupHead : groupHeads) {
- docHeads[i++] = groupHead.doc;
- }
-
- return docHeads;
- }
-
- /**
- * @return the number of group heads found for a query.
- */
- public int groupHeadsSize() {
- return getCollectedGroupHeads().size();
- }
-
- /**
- * Returns the group head and puts it into {@link #temporalResult}.
- * If the group head wasn't encountered before then it will be added to the collected group heads.
- * <p/>
- * The {@link TemporalResult#stop} property will be <code>true</code> if the group head wasn't encountered before
- * otherwise <code>false</code>.
- *
- * @param doc The document to retrieve the group head for.
- * @throws IOException If I/O related errors occur
- */
- protected abstract void retrieveGroupHeadAndAddIfNotExist(int doc) throws IOException;
-
- /**
- * Returns the collected group heads.
- * Subsequent calls should return the same group heads.
- *
- * @return the collected group heads
- */
- protected abstract Collection<GH> getCollectedGroupHeads();
-
- public void collect(int doc) throws IOException {
- retrieveGroupHeadAndAddIfNotExist(doc);
- if (temporalResult.stop) {
- return;
- }
- GH groupHead = temporalResult.groupHead;
-
- // Ok now we need to check if the current doc is more relevant then current doc for this group
- for (int compIDX = 0; ; compIDX++) {
- final int c = reversed[compIDX] * groupHead.compare(compIDX, doc);
- if (c < 0) {
- // Definitely not competitive. So don't even bother to continue
- return;
- } else if (c > 0) {
- // Definitely competitive.
- break;
- } else if (compIDX == compIDXEnd) {
- // Here c=0. If we're at the last comparator, this doc is not
- // competitive, since docs are visited in doc Id order, which means
- // this doc cannot compete with any other document in the queue.
- return;
- }
- }
- groupHead.updateDocHead(doc);
- }
-
- public boolean acceptsDocsOutOfOrder() {
- return true;
- }
-
- /**
- * Contains the result of group head retrieval.
- * To prevent new object creations of this class for every collect.
- */
- protected class TemporalResult {
-
- public GH groupHead;
- public boolean stop;
-
- }
-
- /**
- * Represents a group head. A group head is the most relevant document for a particular group.
- * The relevancy is based is usually based on the sort.
- *
- * The group head contains a group value with its associated most relevant document id.
- */
- public static abstract class GroupHead<GROUP_VALUE_TYPE> {
-
- public final GROUP_VALUE_TYPE groupValue;
- public int doc;
-
- protected GroupHead(GROUP_VALUE_TYPE groupValue, int doc) {
- this.groupValue = groupValue;
- this.doc = doc;
- }
-
- /**
- * Compares the specified document for a specified comparator against the current most relevant document.
- *
- * @param compIDX The comparator index of the specified comparator.
- * @param doc The specified document.
- * @return -1 if the specified document wasn't competitive against the current most relevant document, 1 if the
- * specified document was competitive against the current most relevant document. Otherwise 0.
- * @throws IOException If I/O related errors occur
- */
- protected abstract int compare(int compIDX, int doc) throws IOException;
-
- /**
- * Updates the current most relevant document with the specified document.
- *
- * @param doc The specified document
- * @throws IOException If I/O related errors occur
- */
- protected abstract void updateDocHead(int doc) throws IOException;
-
- }
-
-}
fnp / pylucene.git / blobdiff