| /* |
| * 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 java.util.Collections; |
| import java.util.Objects; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.search.BooleanClause; |
| import org.apache.lucene.search.QueryVisitor; |
| |
| /** |
| * Tracks a reference intervals source, and produces a pseudo-interval that appears |
| * either one position before or one position after each interval from the reference |
| */ |
| class OffsetIntervalsSource extends IntervalsSource { |
| |
| private final IntervalsSource in; |
| private final boolean before; |
| |
| OffsetIntervalsSource(IntervalsSource in, boolean before) { |
| this.in = in; |
| this.before = before; |
| } |
| |
| @Override |
| public IntervalIterator intervals(String field, LeafReaderContext ctx) throws IOException { |
| IntervalIterator it = in.intervals(field, ctx); |
| if (it == null) { |
| return null; |
| } |
| return offset(it); |
| } |
| |
| private IntervalIterator offset(IntervalIterator it) { |
| if (before) { |
| return new OffsetIntervalIterator(it) { |
| @Override |
| public int start() { |
| int pos = in.start(); |
| if (pos == -1) { |
| return -1; |
| } |
| if (pos == NO_MORE_INTERVALS) { |
| return NO_MORE_INTERVALS; |
| } |
| return Math.max(0, pos - 1); |
| } |
| }; |
| } |
| else { |
| return new OffsetIntervalIterator(it) { |
| @Override |
| public int start() { |
| int pos = in.end() + 1; |
| if (pos == 0) { |
| return -1; |
| } |
| if (pos < 0) { // overflow |
| return Integer.MAX_VALUE; |
| } |
| if (pos == Integer.MAX_VALUE) { |
| return Integer.MAX_VALUE - 1; |
| } |
| return pos; |
| } |
| }; |
| } |
| } |
| |
| private static abstract class OffsetIntervalIterator extends IntervalIterator { |
| |
| final IntervalIterator in; |
| |
| OffsetIntervalIterator(IntervalIterator in) { |
| this.in = in; |
| } |
| |
| @Override |
| public int end() { |
| return start(); |
| } |
| |
| @Override |
| public int gaps() { |
| return 0; |
| } |
| |
| @Override |
| public int nextInterval() throws IOException { |
| in.nextInterval(); |
| return start(); |
| } |
| |
| @Override |
| public float matchCost() { |
| return in.matchCost(); |
| } |
| |
| @Override |
| public int docID() { |
| return in.docID(); |
| } |
| |
| @Override |
| public int nextDoc() throws IOException { |
| return in.nextDoc(); |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| return in.advance(target); |
| } |
| |
| @Override |
| public long cost() { |
| return in.cost(); |
| } |
| } |
| |
| @Override |
| public IntervalMatchesIterator matches(String field, LeafReaderContext ctx, int doc) throws IOException { |
| IntervalMatchesIterator mi = in.matches(field, ctx, doc); |
| if (mi == null) { |
| return null; |
| } |
| return IntervalMatches.asMatches(offset(IntervalMatches.wrapMatches(mi, doc)), mi, doc); |
| } |
| |
| @Override |
| public void visit(String field, QueryVisitor visitor) { |
| in.visit(field, visitor.getSubVisitor(BooleanClause.Occur.MUST, new IntervalQuery(field, this))); |
| } |
| |
| @Override |
| public int minExtent() { |
| return 1; |
| } |
| |
| @Override |
| public Collection<IntervalsSource> pullUpDisjunctions() { |
| return Collections.singleton(this); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) return false; |
| OffsetIntervalsSource that = (OffsetIntervalsSource) o; |
| return before == that.before && |
| Objects.equals(in, that.in); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(in, before); |
| } |
| |
| @Override |
| public String toString() { |
| if (before) { |
| return ("PRECEDING(" + in + ")"); |
| } |
| return ("FOLLOWING(" + in + ")"); |
| } |
| } |