+++ /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 org.apache.lucene.index.IndexReader;
-import org.apache.lucene.search.DocIdSet;
-import org.apache.lucene.search.DocIdSetIterator;
-import org.apache.lucene.search.Filter;
-import org.apache.lucene.util.OpenBitSet;
-import org.apache.lucene.util.OpenBitSetDISI;
-
-/**
- * <p>
- * Allows multiple {@link Filter}s to be chained.
- * Logical operations such as <b>NOT</b> and <b>XOR</b>
- * are applied between filters. One operation can be used
- * for all filters, or a specific operation can be declared
- * for each filter.
- * </p>
- * <p>
- * Order in which filters are called depends on
- * the position of the filter in the chain. It's probably
- * more efficient to place the most restrictive filters
- * /least computationally-intensive filters first.
- * </p>
- *
- */
-public class ChainedFilter extends Filter
-{
- public static final int OR = 0;
- public static final int AND = 1;
- public static final int ANDNOT = 2;
- public static final int XOR = 3;
- /**
- * Logical operation when none is declared. Defaults to
- * OR.
- */
- public static int DEFAULT = OR;
-
- /** The filter chain */
- private Filter[] chain = null;
-
- private int[] logicArray;
-
- private int logic = -1;
-
- /**
- * Ctor.
- * @param chain The chain of filters
- */
- public ChainedFilter(Filter[] chain)
- {
- this.chain = chain;
- }
-
- /**
- * Ctor.
- * @param chain The chain of filters
- * @param logicArray Logical operations to apply between filters
- */
- public ChainedFilter(Filter[] chain, int[] logicArray)
- {
- this.chain = chain;
- this.logicArray = logicArray;
- }
-
- /**
- * Ctor.
- * @param chain The chain of filters
- * @param logic Logical operation to apply to ALL filters
- */
- public ChainedFilter(Filter[] chain, int logic)
- {
- this.chain = chain;
- this.logic = logic;
- }
-
- /**
- * {@link Filter#getDocIdSet}.
- */
- @Override
- public DocIdSet getDocIdSet(IndexReader reader) throws IOException
- {
- int[] index = new int[1]; // use array as reference to modifiable int;
- index[0] = 0; // an object attribute would not be thread safe.
- if (logic != -1)
- return getDocIdSet(reader, logic, index);
- else if (logicArray != null)
- return getDocIdSet(reader, logicArray, index);
- else
- return getDocIdSet(reader, DEFAULT, index);
- }
-
- private DocIdSetIterator getDISI(Filter filter, IndexReader reader)
- throws IOException {
- DocIdSet docIdSet = filter.getDocIdSet(reader);
- if (docIdSet == null) {
- return DocIdSet.EMPTY_DOCIDSET.iterator();
- } else {
- DocIdSetIterator iter = docIdSet.iterator();
- if (iter == null) {
- return DocIdSet.EMPTY_DOCIDSET.iterator();
- } else {
- return iter;
- }
- }
- }
-
- private OpenBitSetDISI initialResult(IndexReader reader, int logic, int[] index)
- throws IOException
- {
- OpenBitSetDISI result;
- /**
- * First AND operation takes place against a completely false
- * bitset and will always return zero results.
- */
- if (logic == AND)
- {
- result = new OpenBitSetDISI(getDISI(chain[index[0]], reader), reader.maxDoc());
- ++index[0];
- }
- else if (logic == ANDNOT)
- {
- result = new OpenBitSetDISI(getDISI(chain[index[0]], reader), reader.maxDoc());
- result.flip(0,reader.maxDoc()); // NOTE: may set bits for deleted docs.
- ++index[0];
- }
- else
- {
- result = new OpenBitSetDISI(reader.maxDoc());
- }
- return result;
- }
-
- /** Provide a SortedVIntList when it is definitely
- * smaller than an OpenBitSet
- * @deprecated Either use CachingWrapperFilter, or
- * switch to a different DocIdSet implementation yourself.
- * This method will be removed in Lucene 4.0
- **/
- @Deprecated
- protected final DocIdSet finalResult(OpenBitSetDISI result, int maxDocs) {
- return result;
- }
-
-
- /**
- * Delegates to each filter in the chain.
- * @param reader IndexReader
- * @param logic Logical operation
- * @return DocIdSet
- */
- private DocIdSet getDocIdSet(IndexReader reader, int logic, int[] index)
- throws IOException
- {
- OpenBitSetDISI result = initialResult(reader, logic, index);
- for (; index[0] < chain.length; index[0]++)
- {
- doChain(result, logic, chain[index[0]].getDocIdSet(reader));
- }
- return finalResult(result, reader.maxDoc());
- }
-
- /**
- * Delegates to each filter in the chain.
- * @param reader IndexReader
- * @param logic Logical operation
- * @return DocIdSet
- */
- private DocIdSet getDocIdSet(IndexReader reader, int[] logic, int[] index)
- throws IOException
- {
- if (logic.length != chain.length)
- throw new IllegalArgumentException("Invalid number of elements in logic array");
-
- OpenBitSetDISI result = initialResult(reader, logic[0], index);
- for (; index[0] < chain.length; index[0]++)
- {
- doChain(result, logic[index[0]], chain[index[0]].getDocIdSet(reader));
- }
- return finalResult(result, reader.maxDoc());
- }
-
- @Override
- public String toString()
- {
- StringBuilder sb = new StringBuilder();
- sb.append("ChainedFilter: [");
- for (int i = 0; i < chain.length; i++)
- {
- sb.append(chain[i]);
- sb.append(' ');
- }
- sb.append(']');
- return sb.toString();
- }
-
- private void doChain(OpenBitSetDISI result, int logic, DocIdSet dis)
- throws IOException {
-
- if (dis instanceof OpenBitSet) {
- // optimized case for OpenBitSets
- switch (logic) {
- case OR:
- result.or((OpenBitSet) dis);
- break;
- case AND:
- result.and((OpenBitSet) dis);
- break;
- case ANDNOT:
- result.andNot((OpenBitSet) dis);
- break;
- case XOR:
- result.xor((OpenBitSet) dis);
- break;
- default:
- doChain(result, DEFAULT, dis);
- break;
- }
- } else {
- DocIdSetIterator disi;
- if (dis == null) {
- disi = DocIdSet.EMPTY_DOCIDSET.iterator();
- } else {
- disi = dis.iterator();
- if (disi == null) {
- disi = DocIdSet.EMPTY_DOCIDSET.iterator();
- }
- }
-
- switch (logic) {
- case OR:
- result.inPlaceOr(disi);
- break;
- case AND:
- result.inPlaceAnd(disi);
- break;
- case ANDNOT:
- result.inPlaceNot(disi);
- break;
- case XOR:
- result.inPlaceXor(disi);
- break;
- default:
- doChain(result, DEFAULT, dis);
- break;
- }
- }
- }
-
-}
fnp / pylucene.git / blobdiff