2.x: add doAfterNext & doAfterSuccess to the other types

src/main/java/io/reactivex/Maybe.java

@@ -2273,6 +2273,25 @@ public final Maybe<T> delaySubscription(long delay, TimeUnit unit, Scheduler sch
         return delaySubscription(Flowable.timer(delay, unit, scheduler));
     }
 
+    /**
+     * Calls the specified consumer with the success item after this item has been emitted to the downstream.
+     * <p>Note that the {@code onAfterNext} action is shared between subscriptions and as such
+     * should be thread-safe.
+     * <dl>
+     *  <dt><b>Scheduler:</b></dt>
+     *  <dd>{@code doAfterSuccess} does not operate by default on a particular {@link Scheduler}.</dd>
+     * </dl>
+     * @param onAfterSuccess the Consumer that will be called after emitting an item from upstream to the downstream
+     * @return the new Maybe instance
+     * @since 2.0.1 - experimental
+     */
+    @SchedulerSupport(SchedulerSupport.NONE)
+    @Experimental
+    public final Maybe<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
+        ObjectHelper.requireNonNull(onAfterSuccess, "doAfterSuccess is null");
+        return RxJavaPlugins.onAssembly(new MaybeDoAfterSuccess<T>(this, onAfterSuccess));
+    }
+
     /**
      * Registers an {@link Action} to be called when this Maybe invokes either
      * {@link MaybeObserver#onComplete onSuccess},

src/main/java/io/reactivex/Observable.java

@@ -6416,6 +6416,27 @@ public final Observable<T> distinctUntilChanged(BiPredicate<? super T, ? super T
         return RxJavaPlugins.onAssembly(new ObservableDistinctUntilChanged<T, T>(this, Functions.<T>identity(), comparer));
     }
 
+    /**
+     * Calls the specified consumer with the current item after this item has been emitted to the downstream.
+     * <p>Note that the {@code onAfterNext} action is shared between subscriptions and as such
+     * should be thread-safe.
+     * <dl>
+     *  <dt><b>Scheduler:</b></dt>
+     *  <dd>{@code doAfterNext} does not operate by default on a particular {@link Scheduler}.</dd>
+     *  <td><b>Operator-fusion:</b></dt>
+     *  <dd>This operator supports boundary-limited synchronous or asynchronous queue-fusion.</dd>
+     * </dl>
+     * @param onAfterNext the Consumer that will be called after emitting an item from upstream to the downstream
+     * @return the new Observable instance
+     * @since 2.0.1 - experimental
+     */
+    @SchedulerSupport(SchedulerSupport.NONE)
+    @Experimental
+    public final Observable<T> doAfterNext(Consumer<? super T> onAfterNext) {
+        ObjectHelper.requireNonNull(onAfterNext, "onAfterNext is null");
+        return RxJavaPlugins.onAssembly(new ObservableDoAfterNext<T>(this, onAfterNext));
+    }
+
     /**
      * Registers an {@link Action} to be called when this ObservableSource invokes either
      * {@link Observer#onComplete onComplete} or {@link Observer#onError onError}.

src/main/java/io/reactivex/Single.java

@@ -1716,6 +1716,25 @@ public final <U> Single<T> delaySubscription(long time, TimeUnit unit, Scheduler
         return delaySubscription(Observable.timer(time, unit, scheduler));
     }
 
+    /**
+     * Calls the specified consumer with the success item after this item has been emitted to the downstream.
+     * <p>Note that the {@code doAfterSuccess} action is shared between subscriptions and as such
+     * should be thread-safe.
+     * <dl>
+     *  <dt><b>Scheduler:</b></dt>
+     *  <dd>{@code doAfterSuccess} does not operate by default on a particular {@link Scheduler}.</dd>
+     * </dl>
+     * @param onAfterSuccess the Consumer that will be called after emitting an item from upstream to the downstream
+     * @return the new Single instance
+     * @since 2.0.1 - experimental
+     */
+    @SchedulerSupport(SchedulerSupport.NONE)
+    @Experimental
+    public final Single<T> doAfterSuccess(Consumer<? super T> onAfterSuccess) {
+        ObjectHelper.requireNonNull(onAfterSuccess, "doAfterSuccess is null");
+        return RxJavaPlugins.onAssembly(new SingleDoAfterSuccess<T>(this, onAfterSuccess));
+    }
+
     /**
      * Calls the specified action after this Single signals onSuccess or onError or gets disposed by
      * the downstream.

src/main/java/io/reactivex/internal/operators/maybe/MaybeDoAfterSuccess.java

@@ -0,0 +1,99 @@
+/**
+ * Copyright 2016 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 io.reactivex.internal.operators.maybe;
+
+import io.reactivex.*;
+import io.reactivex.annotations.Experimental;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.exceptions.Exceptions;
+import io.reactivex.functions.Consumer;
+import io.reactivex.internal.disposables.DisposableHelper;
+import io.reactivex.plugins.RxJavaPlugins;
+
+/**
+ * Calls a consumer after pushing the current item to the downstream.
+ * @param <T> the value type
+ * @since 2.0.1 - experimental
+ */
+@Experimental
+public final class MaybeDoAfterSuccess<T> extends AbstractMaybeWithUpstream<T, T> {
+
+    final Consumer<? super T> onAfterSuccess;
+
+    public MaybeDoAfterSuccess(MaybeSource<T> source, Consumer<? super T> onAfterSuccess) {
+        super(source);
+        this.onAfterSuccess = onAfterSuccess;
+    }
+
+    @Override
+    protected void subscribeActual(MaybeObserver<? super T> s) {
+        source.subscribe(new DoAfterObserver<T>(s, onAfterSuccess));
+    }
+
+    static final class DoAfterObserver<T> implements MaybeObserver<T>, Disposable {
+
+        final MaybeObserver<? super T> actual;
+
+        final Consumer<? super T> onAfterSuccess;
+
+        Disposable d;
+
+        DoAfterObserver(MaybeObserver<? super T> actual, Consumer<? super T> onAfterSuccess) {
+            this.actual = actual;
+            this.onAfterSuccess = onAfterSuccess;
+        }
+
+        @Override
+        public void onSubscribe(Disposable d) {
+            if (DisposableHelper.validate(this.d, d)) {
+                this.d = d;
+
+                actual.onSubscribe(this);
+            }
+        }
+
+        @Override
+        public void onSuccess(T t) {
+            actual.onSuccess(t);
+
+            try {
+                onAfterSuccess.accept(t);
+            } catch (Throwable ex) {
+                Exceptions.throwIfFatal(ex);
+             // remember, onSuccess is a terminal event and we can't call onError
+                RxJavaPlugins.onError(ex);
+            }
+        }
+
+        @Override
+        public void onError(Throwable e) {
+            actual.onError(e);
+        }
+
+        @Override
+        public void onComplete() {
+            actual.onComplete();
+        }
+
+        @Override
+        public void dispose() {
+            d.dispose();
+        }
+
+        @Override
+        public boolean isDisposed() {
+            return d.isDisposed();
+        }
+    }
+}

src/main/java/io/reactivex/internal/operators/observable/ObservableDoAfterNext.java

@@ -0,0 +1,77 @@
+/**
+ * Copyright 2016 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 io.reactivex.internal.operators.observable;
+
+import io.reactivex.*;
+import io.reactivex.annotations.Experimental;
+import io.reactivex.functions.Consumer;
+import io.reactivex.internal.observers.BasicFuseableObserver;
+
+/**
+ * Calls a consumer after pushing the current item to the downstream.
+ * @param <T> the value type
+ * @since 2.0.1 - experimental
+ */
+@Experimental
+public final class ObservableDoAfterNext<T> extends AbstractObservableWithUpstream<T, T> {
+
+    final Consumer<? super T> onAfterNext;
+
+    public ObservableDoAfterNext(ObservableSource<T> source, Consumer<? super T> onAfterNext) {
+        super(source);
+        this.onAfterNext = onAfterNext;
+    }
+
+    @Override
+    protected void subscribeActual(Observer<? super T> s) {
+        source.subscribe(new DoAfterObserver<T>(s, onAfterNext));
+    }
+
+    static final class DoAfterObserver<T> extends BasicFuseableObserver<T, T> {
+
+        final Consumer<? super T> onAfterNext;
+
+        DoAfterObserver(Observer<? super T> actual, Consumer<? super T> onAfterNext) {
+            super(actual);
+            this.onAfterNext = onAfterNext;
+        }
+
+        @Override
+        public void onNext(T t) {
+            actual.onNext(t);
+
+            if (sourceMode == NONE) {
+                try {
+                    onAfterNext.accept(t);
+                } catch (Throwable ex) {
+                    fail(ex);
+                }
+            }
+        }
+
+        @Override
+        public int requestFusion(int mode) {
+            return transitiveBoundaryFusion(mode);
+        }
+
+        @Override
+        public T poll() throws Exception {
+            T v = qs.poll();
+            if (v != null) {
+                onAfterNext.accept(v);
+            }
+            return v;
+        }
+    }
+}

src/main/java/io/reactivex/internal/operators/single/SingleDoAfterSuccess.java

@@ -0,0 +1,96 @@
+/**
+ * Copyright 2016 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 io.reactivex.internal.operators.single;
+
+import io.reactivex.*;
+import io.reactivex.annotations.Experimental;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.exceptions.Exceptions;
+import io.reactivex.functions.Consumer;
+import io.reactivex.internal.disposables.DisposableHelper;
+import io.reactivex.plugins.RxJavaPlugins;
+
+/**
+ * Calls a consumer after pushing the current item to the downstream.
+ * @param <T> the value type
+ * @since 2.0.1 - experimental
+ */
+@Experimental
+public final class SingleDoAfterSuccess<T> extends Single<T> {
+
+    final SingleSource<T> source;
+
+    final Consumer<? super T> onAfterSuccess;
+
+    public SingleDoAfterSuccess(SingleSource<T> source, Consumer<? super T> onAfterSuccess) {
+        this.source = source;
+        this.onAfterSuccess = onAfterSuccess;
+    }
+
+    @Override
+    protected void subscribeActual(SingleObserver<? super T> s) {
+        source.subscribe(new DoAfterObserver<T>(s, onAfterSuccess));
+    }
+
+    static final class DoAfterObserver<T> implements SingleObserver<T>, Disposable {
+
+        final SingleObserver<? super T> actual;
+
+        final Consumer<? super T> onAfterSuccess;
+
+        Disposable d;
+
+        DoAfterObserver(SingleObserver<? super T> actual, Consumer<? super T> onAfterSuccess) {
+            this.actual = actual;
+            this.onAfterSuccess = onAfterSuccess;
+        }
+
+        @Override
+        public void onSubscribe(Disposable d) {
+            if (DisposableHelper.validate(this.d, d)) {
+                this.d = d;
+
+                actual.onSubscribe(this);
+            }
+        }
+
+        @Override
+        public void onSuccess(T t) {
+            actual.onSuccess(t);
+
+            try {
+                onAfterSuccess.accept(t);
+            } catch (Throwable ex) {
+                Exceptions.throwIfFatal(ex);
+             // remember, onSuccess is a terminal event and we can't call onError
+                RxJavaPlugins.onError(ex);
+            }
+        }
+
+        @Override
+        public void onError(Throwable e) {
+            actual.onError(e);
+        }
+
+        @Override
+        public void dispose() {
+            d.dispose();
+        }
+
+        @Override
+        public boolean isDisposed() {
+            return d.isDisposed();
+        }
+    }
+}