core/api/src/main/java/org/onosproject/store/service/AsyncIterator.java

/*
 * Copyright 2018-present Open Networking 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.
 */
package org.onosproject.store.service;

import java.util.concurrent.CompletableFuture;

/**
 * Asynchronous iterator.
 */
public interface AsyncIterator<T> {

    /**
     * Returns whether the iterator has a next item.
     *
     * @return whether a next item exists in the iterator
     */
    CompletableFuture<Boolean> hasNext();

    /**
     * Returns the next item in the iterator.
     *
     * @return the next item in the iterator
     */
    CompletableFuture<T> next();
}