X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/FilteredDocIdSetIterator.java diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/FilteredDocIdSetIterator.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/FilteredDocIdSetIterator.java new file mode 100644 index 0000000..afd2657 --- /dev/null +++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/FilteredDocIdSetIterator.java @@ -0,0 +1,85 @@ +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; + +/** + * Abstract decorator class of a DocIdSetIterator + * implementation that provides on-demand filter/validation + * mechanism on an underlying DocIdSetIterator. See {@link + * FilteredDocIdSet}. + */ +public abstract class FilteredDocIdSetIterator extends DocIdSetIterator { + protected DocIdSetIterator _innerIter; + private int doc; + + /** + * Constructor. + * @param innerIter Underlying DocIdSetIterator. + */ + public FilteredDocIdSetIterator(DocIdSetIterator innerIter) { + if (innerIter == null) { + throw new IllegalArgumentException("null iterator"); + } + _innerIter = innerIter; + doc = -1; + } + + /** + * Validation method to determine whether a docid should be in the result set. + * @param doc docid to be tested + * @return true if input docid should be in the result set, false otherwise. + * @see #FilteredDocIdSetIterator(DocIdSetIterator) + */ + abstract protected boolean match(int doc) throws IOException; + + @Override + public int docID() { + return doc; + } + + @Override + public int nextDoc() throws IOException { + while ((doc = _innerIter.nextDoc()) != NO_MORE_DOCS) { + if (match(doc)) { + return doc; + } + } + return doc; + } + + @Override + public int advance(int target) throws IOException { + doc = _innerIter.advance(target); + if (doc != NO_MORE_DOCS) { + if (match(doc)) { + return doc; + } else { + while ((doc = _innerIter.nextDoc()) != NO_MORE_DOCS) { + if (match(doc)) { + return doc; + } + } + return doc; + } + } + return doc; + } + +}