/*
* 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.codecs;
import java.io.Closeable;
import java.io.IOException;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute; // javadocs
import org.apache.lucene.index.Fields;
import org.apache.lucene.util.Accountable;
/**
* Codec API for reading term vectors:
*
* @lucene.experimental
*/
public abstract class TermVectorsReader implements Cloneable, Closeable, Accountable {
/** Sole constructor. (For invocation by subclass
* constructors, typically implicit.) */
protected TermVectorsReader() {
}
/** Returns term vectors for this document, or null if
* term vectors were not indexed. If offsets are
* available they are in an {@link OffsetAttribute}
* available from the {@link org.apache.lucene.index.PostingsEnum}. */
public abstract Fields get(int doc) throws IOException;
/**
* Checks consistency of this reader.
* <p>
* Note that this may be costly in terms of I/O, e.g.
* may involve computing a checksum value against large data files.
* @lucene.internal
*/
public abstract void checkIntegrity() throws IOException;
/** Create a clone that one caller at a time may use to
* read term vectors. */
@Override
public abstract TermVectorsReader clone();
/**
* Returns an instance optimized for merging.
* <p>
* The default implementation returns {@code this} */
public TermVectorsReader getMergeInstance() throws IOException {
return this;
}
}