| 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.*; |
| |
| /** |
| * Position of a term in a document that takes into account the term offset within the phrase. |
| */ |
| final class PhrasePositions { |
| int doc; // current doc |
| int position; // position in doc |
| int count; // remaining pos in this doc |
| int offset; // position in phrase |
| final int ord; // unique across all PhrasePositions instances |
| TermPositions tp; // stream of positions |
| PhrasePositions next; // used to make lists |
| boolean repeats; // there's other pp for same term (e.g. query="1st word 2nd word"~1) |
| |
| PhrasePositions(TermPositions t, int o, int ord) { |
| tp = t; |
| offset = o; |
| this.ord = ord; |
| } |
| |
| final boolean next() throws IOException { // increments to next doc |
| if (!tp.next()) { |
| tp.close(); // close stream |
| doc = Integer.MAX_VALUE; // sentinel value |
| return false; |
| } |
| doc = tp.doc(); |
| position = 0; |
| return true; |
| } |
| |
| final boolean skipTo(int target) throws IOException { |
| if (!tp.skipTo(target)) { |
| tp.close(); // close stream |
| doc = Integer.MAX_VALUE; // sentinel value |
| return false; |
| } |
| doc = tp.doc(); |
| position = 0; |
| return true; |
| } |
| |
| |
| final void firstPosition() throws IOException { |
| count = tp.freq(); // read first pos |
| nextPosition(); |
| } |
| |
| /** |
| * Go to next location of this term current document, and set |
| * <code>position</code> as <code>location - offset</code>, so that a |
| * matching exact phrase is easily identified when all PhrasePositions |
| * have exactly the same <code>position</code>. |
| */ |
| final boolean nextPosition() throws IOException { |
| if (count-- > 0) { // read subsequent pos's |
| position = tp.nextPosition() - offset; |
| return true; |
| } else |
| return false; |
| } |
| } |