io.axoniq.flowcontrol.producer.grpc.ActiveSubscriptions Maven / Gradle / Ivy
/*
* Copyright (c) 2021. AxonIQ
*
* 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 io.axoniq.flowcontrol.producer.grpc;
import java.util.Optional;
/**
* A collection of subscription used to request new items from publishers.
*
* @author Sara Pellegrini
* @author Milan Savic
* @since 1.0
*/
public interface ActiveSubscriptions {
/**
* Adds a new subscription.
* @param subscription
*/
void add(ActiveSubscription subscription);
/**
* Remove a subscription.
* @param subscription
*/
void remove(ActiveSubscription subscription);
/**
* Returns {@code true} if there is no subscription. //TODO rename method
* @return
*/
boolean hasNext();
/**
* Returns the next subscription that should be used to request next item. It doesn't iterate over all subscriptions
* in a specific order, as it can return for many times the same subscription if this has a greater priority,
* depending on the implementation.
*
* @return the next subscription that should be requested for next item.
*/
Optional next();
/**
* Functional interface to request a new item from a publisher.
*
* @author Sara Pellegrini
* @author Milan Savic
* @since 1.0
*/
interface ActiveSubscription {
/**
* Requests a new item from a publisher.
*/
void request();
}
}