| package org.apache.lucene.search.spans; |
| /** |
| * Copyright 2005 The Apache Software Foundation |
| * |
| * Licensed 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 org.apache.lucene.index.Term; |
| import org.apache.lucene.index.DocsAndPositionsEnum; |
| import org.apache.lucene.search.DocIdSetIterator; |
| import org.apache.lucene.util.BytesRef; |
| |
| import java.io.IOException; |
| import java.util.Collections; |
| import java.util.Collection; |
| |
| /** |
| * Expert: |
| * Public for extension only |
| */ |
| public class TermSpans extends Spans { |
| protected final DocsAndPositionsEnum postings; |
| protected final Term term; |
| protected int doc; |
| protected int freq; |
| protected int count; |
| protected int position; |
| protected boolean readPayload; |
| |
| public TermSpans(DocsAndPositionsEnum postings, Term term) { |
| this.postings = postings; |
| this.term = term; |
| doc = -1; |
| } |
| |
| // only for EmptyTermSpans (below) |
| TermSpans() { |
| term = null; |
| postings = null; |
| } |
| |
| @Override |
| public boolean next() throws IOException { |
| if (count == freq) { |
| if (postings == null) { |
| return false; |
| } |
| doc = postings.nextDoc(); |
| if (doc == DocIdSetIterator.NO_MORE_DOCS) { |
| return false; |
| } |
| freq = postings.freq(); |
| count = 0; |
| } |
| position = postings.nextPosition(); |
| count++; |
| readPayload = false; |
| return true; |
| } |
| |
| @Override |
| public boolean skipTo(int target) throws IOException { |
| assert target > doc; |
| doc = postings.advance(target); |
| if (doc == DocIdSetIterator.NO_MORE_DOCS) { |
| return false; |
| } |
| |
| freq = postings.freq(); |
| count = 0; |
| position = postings.nextPosition(); |
| count++; |
| readPayload = false; |
| return true; |
| } |
| |
| @Override |
| public int doc() { |
| return doc; |
| } |
| |
| @Override |
| public int start() { |
| return position; |
| } |
| |
| @Override |
| public int end() { |
| return position + 1; |
| } |
| |
| @Override |
| public long cost() { |
| return postings.cost(); |
| } |
| |
| // TODO: Remove warning after API has been finalized |
| @Override |
| public Collection<byte[]> getPayload() throws IOException { |
| final BytesRef payload = postings.getPayload(); |
| readPayload = true; |
| final byte[] bytes; |
| if (payload != null) { |
| bytes = new byte[payload.length]; |
| System.arraycopy(payload.bytes, payload.offset, bytes, 0, payload.length); |
| } else { |
| bytes = null; |
| } |
| return Collections.singletonList(bytes); |
| } |
| |
| // TODO: Remove warning after API has been finalized |
| @Override |
| public boolean isPayloadAvailable() throws IOException { |
| return readPayload == false && postings.getPayload() != null; |
| } |
| |
| @Override |
| public String toString() { |
| return "spans(" + term.toString() + ")@" + |
| (doc == -1 ? "START" : (doc == Integer.MAX_VALUE) ? "END" : doc + "-" + position); |
| } |
| |
| public DocsAndPositionsEnum getPostings() { |
| return postings; |
| } |
| |
| private static final class EmptyTermSpans extends TermSpans { |
| |
| @Override |
| public boolean next() { |
| return false; |
| } |
| |
| @Override |
| public boolean skipTo(int target) { |
| return false; |
| } |
| |
| @Override |
| public int doc() { |
| return DocIdSetIterator.NO_MORE_DOCS; |
| } |
| |
| @Override |
| public int start() { |
| return -1; |
| } |
| |
| @Override |
| public int end() { |
| return -1; |
| } |
| |
| @Override |
| public Collection<byte[]> getPayload() { |
| return null; |
| } |
| |
| @Override |
| public boolean isPayloadAvailable() { |
| return false; |
| } |
| |
| @Override |
| public long cost() { |
| return 0; |
| } |
| } |
| |
| public static final TermSpans EMPTY_TERM_SPANS = new EmptyTermSpans(); |
| } |