rx.plugins.RxJavaObservableExecutionHook 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.plugins;
import rx.Observable;
import rx.Observable.OnSubscribe;
import rx.Observable.Operator;
import rx.Subscriber;
import rx.Subscription;
import rx.functions.Func1;
/**
* Abstract ExecutionHook with invocations at different lifecycle points of {@link Observable} execution with a
* default no-op implementation.
*
* See {@link RxJavaPlugins} or the RxJava GitHub Wiki for information on configuring plugins:
* https://github.com/ReactiveX/RxJava/wiki/Plugins.
*
* Note on thread-safety and performance:
*
* A single implementation of this class will be used globally so methods on this class will be invoked
* concurrently from multiple threads so all functionality must be thread-safe.
*
* Methods are also invoked synchronously and will add to execution time of the observable so all behavior
* should be fast. If anything time-consuming is to be done it should be spawned asynchronously onto separate
* worker threads.
*
*/
public abstract class RxJavaObservableExecutionHook { // NOPMD
/**
* Invoked during the construction by {@link Observable#unsafeCreate(OnSubscribe)}
*
* This can be used to decorate or replace the onSubscribe function or just perform extra
* logging, metrics and other such things and pass through the function.
*
* @param the value type
* @param f
* original {@link OnSubscribe}<{@code T}> to be executed
* @return {@link OnSubscribe}<{@code T}> function that can be modified, decorated, replaced or just
* returned as a pass through
*/
@Deprecated
public OnSubscribe onCreate(OnSubscribe f) {
return f;
}
/**
* Invoked before {@link Observable#subscribe(rx.Subscriber)} is about to be executed.
*
* This can be used to decorate or replace the onSubscribe function or just perform extra
* logging, metrics and other such things and pass through the function.
*
* @param the value type
* @param observableInstance the parent observable instance
* @param onSubscribe
* original {@link OnSubscribe}<{@code T}> to be executed
* @return {@link OnSubscribe}<{@code T}> function that can be modified, decorated, replaced or just
* returned as a pass through
*/
@Deprecated
public OnSubscribe onSubscribeStart(Observable observableInstance, final OnSubscribe onSubscribe) {
// pass through by default
return onSubscribe;
}
/**
* Invoked after successful execution of {@link Observable#subscribe(rx.Subscriber)} with returned
* {@link Subscription}.
*
* This can be used to decorate or replace the {@link Subscription} instance or just perform extra logging,
* metrics and other such things and pass through the subscription.
*
* @param the value type
* @param subscription
* original {@link Subscription}
* @return {@link Subscription} subscription that can be modified, decorated, replaced or just returned as a
* pass through
*/
@Deprecated
public Subscription onSubscribeReturn(Subscription subscription) {
// pass through by default
return subscription;
}
/**
* Invoked after failed execution of {@link Observable#subscribe(Subscriber)} with thrown Throwable.
*
* This is not errors emitted via {@link Subscriber#onError(Throwable)} but exceptions thrown when
* attempting to subscribe to a {@link Func1}<{@link Subscriber}{@code }, {@link Subscription}>.
*
* @param the value type
* @param e
* Throwable thrown by {@link Observable#subscribe(Subscriber)}
* @return Throwable that can be decorated, replaced or just returned as a pass through
*/
@Deprecated
public Throwable onSubscribeError(Throwable e) {
// pass through by default
return e;
}
/**
* Invoked just as the operator functions is called to bind two operations together into a new
* {@link Observable} and the return value is used as the lifted function
*
* This can be used to decorate or replace the {@link Operator} instance or just perform extra
* logging, metrics and other such things and pass through the onSubscribe.
*
* @param the upstream's value type (input)
* @param the downstream's value type (output)
* @param lift
* original {@link Operator}{@code }
* @return {@link Operator}{@code } function that can be modified, decorated, replaced or just
* returned as a pass through
*/
@Deprecated
public Operator onLift(final Operator lift) {
return lift;
}
}