/** * 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.internal.util; import java.io.Serializable; import org.reactivestreams.*; import io.reactivex.Observer; import io.reactivex.disposables.Disposable; import io.reactivex.internal.functions.ObjectHelper; /** * 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 ObjectHelper.equals(e, n.e); } return false; } } /** * Wraps a Subscription. */ static final class SubscriptionNotification implements Serializable { private static final long serialVersionUID = -1322257508628817540L; final Subscription s; SubscriptionNotification(Subscription s) { this.s = s; } @Override public String toString() { return "NotificationLite.Subscription[" + s + "]"; } } /** * Wraps a Disposable. */ static final class DisposableNotification implements Serializable { private static final long serialVersionUID = -7482590109178395495L; final Disposable d; DisposableNotification(Disposable d) { this.d = d; } @Override public String toString() { return "NotificationLite.Disposable[" + d + "]"; } } /** * Converts a value into a notification value. * @param <T> the actual value type * @param value the value to convert * @return the notification representing the value */ public static <T> 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 <T> the expected value type when unwrapped * @param o the notification object * @return the extracted value */ @SuppressWarnings("unchecked") public static <T> 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).s; } public static Disposable getDisposable(Object o) { return ((DisposableNotification)o).d; } /** * Calls the appropriate Subscriber method based on the type of the notification. * <p>Does not check for a subscription notification, see {@link #acceptFull(Object, Subscriber)}. * @param <T> 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 <T> boolean accept(Object o, Subscriber<? super T> 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. * <p>Does not check for a subscription notification. * @param <T> the expected value type when unwrapped * @param o the notification object * @param s the Observer to call methods on * @return true if the notification was a terminal event (i.e., complete or error) */ @SuppressWarnings("unchecked") public static <T> boolean accept(Object o, Observer<? super T> 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 Subscriber method based on the type of the notification. * @param <T> 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 <T> boolean acceptFull(Object o, Subscriber<? super T> 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).s); return false; } s.onNext((T)o); return false; } /** * Calls the appropriate Observer method based on the type of the notification. * @param <T> 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, Observer) */ @SuppressWarnings("unchecked") public static <T> boolean acceptFull(Object o, Observer<? super T> s) { if (o == COMPLETE) { s.onComplete(); return true; } else if (o instanceof ErrorNotification) { s.onError(((ErrorNotification)o).e); return true; } else if (o instanceof DisposableNotification) { s.onSubscribe(((DisposableNotification)o).d); return false; } s.onNext((T)o); return false; } @Override public String toString() { return "NotificationLite.Complete"; } }