io.reactivex.rxjava3.internal.util.NotificationLite Maven / Gradle / Ivy
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/*
* Copyright (c) 2016-present, RxJava Contributors.
*
* 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.reactivex.rxjava3.internal.util;
import java.io.Serializable;
import java.util.Objects;
import org.reactivestreams.*;
import io.reactivex.rxjava3.core.Observer;
import io.reactivex.rxjava3.disposables.Disposable;
/**
* Lightweight notification handling utility class.
*/
public enum NotificationLite {
COMPLETE
;
/**
* Wraps a Throwable.
*/
static final class ErrorNotification implements Serializable {
private static final long serialVersionUID = -8759979445933046293L;
final Throwable e;
ErrorNotification(Throwable e) {
this.e = e;
}
@Override
public String toString() {
return "NotificationLite.Error[" + e + "]";
}
@Override
public int hashCode() {
return e.hashCode();
}
@Override
public boolean equals(Object obj) {
if (obj instanceof ErrorNotification) {
ErrorNotification n = (ErrorNotification) obj;
return Objects.equals(e, n.e);
}
return false;
}
}
/**
* Wraps a Subscription.
*/
static final class SubscriptionNotification implements Serializable {
private static final long serialVersionUID = -1322257508628817540L;
final Subscription upstream;
SubscriptionNotification(Subscription s) {
this.upstream = s;
}
@Override
public String toString() {
return "NotificationLite.Subscription[" + upstream + "]";
}
}
/**
* Wraps a Disposable.
*/
static final class DisposableNotification implements Serializable {
private static final long serialVersionUID = -7482590109178395495L;
final Disposable upstream;
DisposableNotification(Disposable d) {
this.upstream = d;
}
@Override
public String toString() {
return "NotificationLite.Disposable[" + upstream + "]";
}
}
/**
* Converts a value into a notification value.
* @param the actual value type
* @param value the value to convert
* @return the notification representing the value
*/
public static Object next(T value) {
return value;
}
/**
* Returns a complete notification.
* @return a complete notification
*/
public static Object complete() {
return COMPLETE;
}
/**
* Converts a Throwable into a notification value.
* @param e the Throwable to convert
* @return the notification representing the Throwable
*/
public static Object error(Throwable e) {
return new ErrorNotification(e);
}
/**
* Converts a Subscription into a notification value.
* @param s the Subscription to convert
* @return the notification representing the Subscription
*/
public static Object subscription(Subscription s) {
return new SubscriptionNotification(s);
}
/**
* Converts a Disposable into a notification value.
* @param d the disposable to convert
* @return the notification representing the Disposable
*/
public static Object disposable(Disposable d) {
return new DisposableNotification(d);
}
/**
* Checks if the given object represents a complete notification.
* @param o the object to check
* @return true if the object represents a complete notification
*/
public static boolean isComplete(Object o) {
return o == COMPLETE;
}
/**
* Checks if the given object represents a error notification.
* @param o the object to check
* @return true if the object represents a error notification
*/
public static boolean isError(Object o) {
return o instanceof ErrorNotification;
}
/**
* Checks if the given object represents a subscription notification.
* @param o the object to check
* @return true if the object represents a subscription notification
*/
public static boolean isSubscription(Object o) {
return o instanceof SubscriptionNotification;
}
public static boolean isDisposable(Object o) {
return o instanceof DisposableNotification;
}
/**
* Extracts the value from the notification object.
* @param the expected value type when unwrapped
* @param o the notification object
* @return the extracted value
*/
@SuppressWarnings("unchecked")
public static T getValue(Object o) {
return (T)o;
}
/**
* Extracts the Throwable from the notification object.
* @param o the notification object
* @return the extracted Throwable
*/
public static Throwable getError(Object o) {
return ((ErrorNotification)o).e;
}
/**
* Extracts the Subscription from the notification object.
* @param o the notification object
* @return the extracted Subscription
*/
public static Subscription getSubscription(Object o) {
return ((SubscriptionNotification)o).upstream;
}
public static Disposable getDisposable(Object o) {
return ((DisposableNotification)o).upstream;
}
/**
* Calls the appropriate Subscriber method based on the type of the notification.
* Does not check for a subscription notification, see {@link #acceptFull(Object, Subscriber)}.
* @param the expected value type when unwrapped
* @param o the notification object
* @param s the subscriber to call methods on
* @return true if the notification was a terminal event (i.e., complete or error)
* @see #acceptFull(Object, Subscriber)
*/
@SuppressWarnings("unchecked")
public static boolean accept(Object o, Subscriber s) {
if (o == COMPLETE) {
s.onComplete();
return true;
} else
if (o instanceof ErrorNotification) {
s.onError(((ErrorNotification)o).e);
return true;
}
s.onNext((T)o);
return false;
}
/**
* Calls the appropriate Observer method based on the type of the notification.
* Does not check for a subscription notification.
* @param the expected value type when unwrapped
* @param o the notification object
* @param observer the Observer to call methods on
* @return true if the notification was a terminal event (i.e., complete or error)
*/
@SuppressWarnings("unchecked")
public static boolean accept(Object o, Observer observer) {
if (o == COMPLETE) {
observer.onComplete();
return true;
} else
if (o instanceof ErrorNotification) {
observer.onError(((ErrorNotification)o).e);
return true;
}
observer.onNext((T)o);
return false;
}
/**
* Calls the appropriate Subscriber method based on the type of the notification.
* @param the expected value type when unwrapped
* @param o the notification object
* @param s the subscriber to call methods on
* @return true if the notification was a terminal event (i.e., complete or error)
* @see #accept(Object, Subscriber)
*/
@SuppressWarnings("unchecked")
public static boolean acceptFull(Object o, Subscriber s) {
if (o == COMPLETE) {
s.onComplete();
return true;
} else
if (o instanceof ErrorNotification) {
s.onError(((ErrorNotification)o).e);
return true;
} else
if (o instanceof SubscriptionNotification) {
s.onSubscribe(((SubscriptionNotification)o).upstream);
return false;
}
s.onNext((T)o);
return false;
}
/**
* Calls the appropriate Observer method based on the type of the notification.
* @param the expected value type when unwrapped
* @param o the notification object
* @param observer the subscriber to call methods on
* @return true if the notification was a terminal event (i.e., complete or error)
* @see #accept(Object, Observer)
*/
@SuppressWarnings("unchecked")
public static boolean acceptFull(Object o, Observer observer) {
if (o == COMPLETE) {
observer.onComplete();
return true;
} else
if (o instanceof ErrorNotification) {
observer.onError(((ErrorNotification)o).e);
return true;
} else
if (o instanceof DisposableNotification) {
observer.onSubscribe(((DisposableNotification)o).upstream);
return false;
}
observer.onNext((T)o);
return false;
}
@Override
public String toString() {
return "NotificationLite.Complete";
}
}