| /* |
| * 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. |
| */ |
| |
| package org.apache.lucene.queries.intervals; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.search.MatchesIterator; |
| import org.apache.lucene.search.QueryVisitor; |
| |
| /** |
| * A helper class for {@link IntervalQuery} that provides an {@link IntervalIterator} for a given |
| * field and segment |
| * |
| * <p>Static constructor functions for various different sources can be found in the {@link |
| * Intervals} class |
| */ |
| public abstract class IntervalsSource { |
| |
| /** |
| * Create an {@link IntervalIterator} exposing the minimum intervals defined by this {@link |
| * IntervalsSource} |
| * |
| * <p>Returns {@code null} if no intervals for this field exist in this segment |
| * |
| * @param field the field to read positions from |
| * @param ctx the context for which to return the iterator |
| */ |
| public abstract IntervalIterator intervals(String field, LeafReaderContext ctx) |
| throws IOException; |
| |
| /** |
| * Return a {@link MatchesIterator} over the intervals defined by this {@link IntervalsSource} for |
| * a given document and field |
| * |
| * <p>Returns {@code null} if no intervals exist in the given document and field |
| * |
| * @param field the field to read positions from |
| * @param ctx the document's context |
| * @param doc the document to return matches for |
| */ |
| public abstract IntervalMatchesIterator matches(String field, LeafReaderContext ctx, int doc) |
| throws IOException; |
| |
| /** Expert: visit the tree of sources */ |
| public abstract void visit(String field, QueryVisitor visitor); |
| |
| /** Return the minimum possible width of an interval returned by this source */ |
| public abstract int minExtent(); |
| |
| /** |
| * Expert: return the set of disjunctions that make up this IntervalsSource |
| * |
| * <p>Most implementations can return {@code Collections.singleton(this)} |
| */ |
| public abstract Collection<IntervalsSource> pullUpDisjunctions(); |
| |
| @Override |
| public abstract int hashCode(); |
| |
| @Override |
| public abstract boolean equals(Object other); |
| |
| @Override |
| public abstract String toString(); |
| } |