io.atomix.collections.DistributedQueue Maven / Gradle / Ivy
/*
* Copyright 2015 the original author or authors.
*
* 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.atomix.collections;
import io.atomix.collections.internal.QueueCommands;
import io.atomix.collections.util.DistributedQueueFactory;
import io.atomix.copycat.client.CopycatClient;
import io.atomix.resource.AbstractResource;
import io.atomix.resource.ReadConsistency;
import io.atomix.resource.ResourceTypeInfo;
import java.util.Properties;
import java.util.concurrent.CompletableFuture;
/**
* Distributed collection designed for holding ordered items for processing.
*
* The distributed queue is closely modeled on Java's queues. All methods present in the
* {@link java.util.Queue} interface are present in this interface. Queued items are held in
* memory on each stateful node and backed by replicated logs on disk, thus the size of a queue
* is limited by the memory available to the smallest node in the cluster.
*
* Internally, {@code DistributedQueue} uses an {@link java.util.ArrayDeque} to enqueue items
* in memory in the replicated state machine. Operations submitted through this interface are
* replicated and result in calling the associated method on the replicated {@link java.util.ArrayDeque}
* on each stateful node.
*
* To create a distributed queue, use the {@code getQueue} factory method:
*
* {@code
* DistributedQueue queue = atomix.getQueue("foo").get();
* }
*
* All queue modification operations are linearizable, so items added to or removed from the queue will
* be immediately reflected from the perspective of all clients operating on the queue. The queue is
* shared by processes based on the queue name.
*
* Queues support relaxed consistency levels for some read operations line {@link #size(ReadConsistency)}
* and {@link #contains(Object, ReadConsistency)}. By default, read operations on a queue are linearizable
* but require some level of communication between nodes.
*
* @param The queue value type.
* @author Jordan Halterman
*/
@ResourceTypeInfo(id=-14, factory=DistributedQueueFactory.class)
public class DistributedQueue extends AbstractResource> {
public DistributedQueue(CopycatClient client, Properties options) {
super(client, options);
}
/**
* Adds a value to the set.
*
* @param value The value to add.
* @return A completable future to be completed with the result once complete.
*/
public CompletableFuture add(T value) {
return client.submit(new QueueCommands.Add(value));
}
/**
* Adds a value to the queue.
*
* @param value The value to add.
* @return A completable future to be completed with the result once complete.
*/
public CompletableFuture offer(T value) {
return client.submit(new QueueCommands.Offer(value));
}
/**
* Removes a value from the queue.
*
* @return A completable future to be completed with the result once complete.
*/
@SuppressWarnings("unchecked")
public CompletableFuture peek() {
return client.submit(new QueueCommands.Peek()).thenApply(v -> (T) v);
}
/**
* Removes a value from the queue.
*
* @return A completable future to be completed with the result once complete.
*/
@SuppressWarnings("unchecked")
public CompletableFuture poll() {
return client.submit(new QueueCommands.Poll()).thenApply(v -> (T) v);
}
/**
* Removes a value from the queue.
*
* @return A completable future to be completed with the result once complete.
*/
@SuppressWarnings("unchecked")
public CompletableFuture element() {
return client.submit(new QueueCommands.Element()).thenApply(v -> (T) v);
}
/**
* Removes a value from the queue.
*
* @return A completable future to be completed with the result once complete.
*/
@SuppressWarnings("unchecked")
public CompletableFuture remove() {
return client.submit(new QueueCommands.Remove()).thenApply(v -> (T) v);
}
/**
* Removes a value from the set.
*
* @param value The value to remove.
* @return A completable future to be completed with the result once complete.
*/
public CompletableFuture remove(T value) {
return client.submit(new QueueCommands.Remove(value)).thenApply(v -> (boolean) v);
}
/**
* Checks whether the set contains a value.
*
* @param value The value to check.
* @return A completable future to be completed with the result once complete.
*/
public CompletableFuture contains(Object value) {
return client.submit(new QueueCommands.Contains(value));
}
/**
* Checks whether the set contains a value.
*
* @param value The value to check.
* @param consistency The read consistency level.
* @return A completable future to be completed with the result once complete.
*/
public CompletableFuture contains(Object value, ReadConsistency consistency) {
return client.submit(new QueueCommands.Contains(value, consistency.level()));
}
/**
* Gets the set count.
*
* @return A completable future to be completed with the set count.
*/
public CompletableFuture size() {
return client.submit(new QueueCommands.Size());
}
/**
* Gets the set count.
*
* @param consistency The read consistency level.
* @return A completable future to be completed with the set count.
*/
public CompletableFuture size(ReadConsistency consistency) {
return client.submit(new QueueCommands.Size(consistency.level()));
}
/**
* Checks whether the set is empty.
*
* @return A completable future to be completed with a boolean value indicating whether the set is empty.
*/
public CompletableFuture isEmpty() {
return client.submit(new QueueCommands.IsEmpty());
}
/**
* Checks whether the set is empty.
*
* @param consistency The read consistency level.
* @return A completable future to be completed with a boolean value indicating whether the set is empty.
*/
public CompletableFuture isEmpty(ReadConsistency consistency) {
return client.submit(new QueueCommands.IsEmpty(consistency.level()));
}
/**
* Removes all values from the set.
*
* @return A completable future to be completed once the operation is complete.
*/
public CompletableFuture clear() {
return client.submit(new QueueCommands.Clear());
}
}