package org.apache.lucene.index;
/**
* 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 java.io.Closeable;
/** TermDocs provides an interface for enumerating <document, frequency>
pairs for a term. <p> The document portion names each document containing
the term. Documents are indicated by number. The frequency portion gives
the number of times the term occurred in each document. <p> The pairs are
ordered by document number.
@see IndexReader#termDocs()
*/
public interface TermDocs extends Closeable {
/** Sets this to the data for a term.
* The enumeration is reset to the start of the data for this term.
*/
void seek(Term term) throws IOException;
/** Sets this to the data for the current term in a {@link TermEnum}.
* This may be optimized in some implementations.
*/
void seek(TermEnum termEnum) throws IOException;
/** Returns the current document number. <p> This is invalid until {@link
#next()} is called for the first time.*/
int doc();
/** Returns the frequency of the term within the current document. <p> This
is invalid until {@link #next()} is called for the first time.*/
int freq();
/** Moves to the next pair in the enumeration. <p> Returns true iff there is
such a next pair in the enumeration. */
boolean next() throws IOException;
/** Attempts to read multiple entries from the enumeration, up to length of
* <i>docs</i>. Document numbers are stored in <i>docs</i>, and term
* frequencies are stored in <i>freqs</i>. The <i>freqs</i> array must be as
* long as the <i>docs</i> array.
*
* <p>Returns the number of entries read. Zero is only returned when the
* stream has been exhausted. */
int read(int[] docs, int[] freqs) throws IOException;
/** Skips entries to the first beyond the current whose document number is
* greater than or equal to <i>target</i>. <p>Returns true iff there is such
* an entry. <p>Behaves as if written: <pre>
* boolean skipTo(int target) {
* do {
* if (!next())
* return false;
* } while (target > doc());
* return true;
* }
* </pre>
* Some implementations are considerably more efficient than that.
*/
boolean skipTo(int target) throws IOException;
/** Frees associated resources. */
void close() throws IOException;
}