util/kvstore/KVStoreIterator.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.util.kvstore;
0019
0020 import java.io.Closeable;
0021 import java.util.Iterator;
0022 import java.util.List;
0023
0024 import org.apache.spark.annotation.Private;
0025
0026 /**
0027  * An iterator for KVStore.
0028  *
0029  * <p>
0030  * Iterators may keep references to resources that need to be closed. It's recommended that users
0031  * explicitly close iterators after they're used.
0032  * </p>
0033  */
0034 @Private
0035 public interface KVStoreIterator<T> extends Iterator<T>, Closeable {
0036
0037   /**
0038    * Retrieve multiple elements from the store.
0039    *
0040    * @param max Maximum number of elements to retrieve.
0041    */
0042   List<T> next(int max);
0043
0044   /**
0045    * Skip in the iterator.
0046    *
0047    * @return Whether there are items left after skipping.
0048    */
0049   boolean skip(long n);
0050
0051 }