rx.subscriptions.CompositeSubscription Maven / Gradle / Ivy
/**
* Copyright 2014 Netflix, Inc.
*
* 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 rx.subscriptions;
import rx.Subscription;
import rx.exceptions.Exceptions;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Subscription that represents a group of Subscriptions that are unsubscribed together.
*
* All methods of this class are thread-safe.
*/
public final class CompositeSubscription implements Subscription {
private Set subscriptions;
private volatile boolean unsubscribed;
/**
* Constructs an empty Composite subscription.
*/
public CompositeSubscription() {
// start empty
}
public CompositeSubscription(final Subscription... subscriptions) {
this.subscriptions = new HashSet(Arrays.asList(subscriptions));
}
@Override
public boolean isUnsubscribed() {
return unsubscribed;
}
/**
* Adds a new {@link Subscription} to this {@code CompositeSubscription} if the
* {@code CompositeSubscription} is not yet unsubscribed. If the {@code CompositeSubscription} is
* unsubscribed, {@code add} will indicate this by explicitly unsubscribing the new {@code Subscription} as
* well.
*
* @param s
* the {@link Subscription} to add
*/
public void add(final Subscription s) {
if (s.isUnsubscribed()) {
return;
}
if (!unsubscribed) {
synchronized (this) {
if (!unsubscribed) {
if (subscriptions == null) {
subscriptions = new HashSet(4);
}
subscriptions.add(s);
return;
}
}
}
// call after leaving the synchronized block so we're not holding a lock while executing this
s.unsubscribe();
}
/**
* Adds collection of {@link Subscription} to this {@code CompositeSubscription} if the
* {@code CompositeSubscription} is not yet unsubscribed. If the {@code CompositeSubscription} is
* unsubscribed, {@code addAll} will indicate this by explicitly unsubscribing all {@code Subscription} in collection as
* well.
*
* @param subscriptions
* the collection of {@link Subscription} to add
*/
public void addAll(final Subscription... subscriptions) {
if (!unsubscribed) {
synchronized (this) {
if (!unsubscribed) {
if (this.subscriptions == null) {
this.subscriptions = new HashSet(subscriptions.length);
}
for (Subscription s : subscriptions) {
if (!s.isUnsubscribed()) {
this.subscriptions.add(s);
}
}
return;
}
}
}
for (Subscription s : subscriptions) {
s.unsubscribe();
}
}
/**
* Removes a {@link Subscription} from this {@code CompositeSubscription}, and unsubscribes the
* {@link Subscription}.
*
* @param s
* the {@link Subscription} to remove
*/
public void remove(final Subscription s) {
if (!unsubscribed) {
boolean unsubscribe;
synchronized (this) {
if (unsubscribed || subscriptions == null) {
return;
}
unsubscribe = subscriptions.remove(s);
}
if (unsubscribe) {
// if we removed successfully we then need to call unsubscribe on it (outside of the lock)
s.unsubscribe();
}
}
}
/**
* Unsubscribes any subscriptions that are currently part of this {@code CompositeSubscription} and remove
* them from the {@code CompositeSubscription} so that the {@code CompositeSubscription} is empty and
* able to manage new subscriptions.
*/
public void clear() {
if (!unsubscribed) {
Collection unsubscribe;
synchronized (this) {
if (unsubscribed || subscriptions == null) {
return;
} else {
unsubscribe = subscriptions;
subscriptions = null;
}
}
unsubscribeFromAll(unsubscribe);
}
}
/**
* Unsubscribes itself and all inner subscriptions.
* After call of this method, new {@code Subscription}s added to {@link CompositeSubscription}
* will be unsubscribed immediately.
*/
@Override
public void unsubscribe() {
if (!unsubscribed) {
Collection unsubscribe;
synchronized (this) {
if (unsubscribed) {
return;
}
unsubscribed = true;
unsubscribe = subscriptions;
subscriptions = null;
}
// we will only get here once
unsubscribeFromAll(unsubscribe);
}
}
private static void unsubscribeFromAll(Collection subscriptions) {
if (subscriptions == null) {
return;
}
List es = null;
for (Subscription s : subscriptions) {
try {
s.unsubscribe();
} catch (Throwable e) {
if (es == null) {
es = new ArrayList();
}
es.add(e);
}
}
Exceptions.throwIfAny(es);
}
/**
* Returns true if this composite is not unsubscribed and contains subscriptions.
*
* @return {@code true} if this composite is not unsubscribed and contains subscriptions.
* @since 1.0.7
*/
public boolean hasSubscriptions() {
if (!unsubscribed) {
synchronized (this) {
return !unsubscribed && subscriptions != null && !subscriptions.isEmpty();
}
}
return false;
}
}