rx.internal.operators.OnSubscribeGroupJoin 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.internal.operators;
import java.util.*;
import rx.*;
import rx.Observable;
import rx.Observable.OnSubscribe;
import rx.Observer;
import rx.exceptions.Exceptions;
import rx.functions.*;
import rx.observers.*;
import rx.subjects.*;
import rx.subscriptions.*;
/**
* Correlates two sequences when they overlap and groups the results.
*
* @see MSDN: Observable.GroupJoin
* @param the left value type
* @param the right value type
* @param the value type of the left duration
* @param the value type of the right duration
* @param the result value type
*/
public final class OnSubscribeGroupJoin implements OnSubscribe {
final Observable left;
final Observable right;
final Func1> leftDuration;
final Func1> rightDuration;
final Func2, ? extends R> resultSelector;
public OnSubscribeGroupJoin(
Observable left,
Observable right,
Func1> leftDuration,
Func1> rightDuration,
Func2, ? extends R> resultSelector) {
this.left = left;
this.right = right;
this.leftDuration = leftDuration;
this.rightDuration = rightDuration;
this.resultSelector = resultSelector;
}
@Override
public void call(Subscriber child) {
ResultManager ro = new ResultManager(new SerializedSubscriber(child));
child.add(ro);
ro.init();
}
/** Manages sub-observers and subscriptions. */
final class ResultManager extends HashMap>implements Subscription {
// HashMap aspect of `this` refers to `leftMap`
private static final long serialVersionUID = -3035156013812425335L;
final RefCountSubscription cancel;
final Subscriber subscriber;
final CompositeSubscription group;
/** Guarded by this. */
int leftIds;
/** Guarded by this. */
int rightIds;
/** Guarded by this. */
final Map rightMap = new HashMap(); // NOPMD
/** Guarded by this. */
boolean leftDone;
/** Guarded by this. */
boolean rightDone;
public ResultManager(Subscriber subscriber) {
super();
this.subscriber = subscriber;
this.group = new CompositeSubscription();
this.cancel = new RefCountSubscription(group);
}
public void init() {
Subscriber s1 = new LeftObserver();
Subscriber s2 = new RightObserver();
group.add(s1);
group.add(s2);
left.unsafeSubscribe(s1);
right.unsafeSubscribe(s2);
}
@Override
public void unsubscribe() {
cancel.unsubscribe();
}
@Override
public boolean isUnsubscribed() {
return cancel.isUnsubscribed();
}
Map> leftMap() {
return this;
}
/**
* Notify everyone and cleanup.
* @param e the exception
*/
void errorAll(Throwable e) {
List> list;
synchronized (ResultManager.this) {
list = new ArrayList>(leftMap().values());
leftMap().clear();
rightMap.clear();
}
for (Observer o : list) {
o.onError(e);
}
subscriber.onError(e);
cancel.unsubscribe();
}
/**
* Notify only the main subscriber and cleanup.
* @param e the exception
*/
void errorMain(Throwable e) {
synchronized (ResultManager.this) {
leftMap().clear();
rightMap.clear();
}
subscriber.onError(e);
cancel.unsubscribe();
}
void complete(List> list) {
if (list != null) {
for (Observer o : list) {
o.onCompleted();
}
subscriber.onCompleted();
cancel.unsubscribe();
}
}
/** Observe the left source. */
final class LeftObserver extends Subscriber {
@Override
public void onNext(T1 args) {
try {
int id;
Subject subj = PublishSubject.create();
Observer subjSerial = new SerializedObserver(subj);
synchronized (ResultManager.this) {
id = leftIds++;
leftMap().put(id, subjSerial);
}
Observable window = Observable.create(new WindowObservableFunc(subj, cancel));
Observable duration = leftDuration.call(args);
Subscriber d1 = new LeftDurationObserver(id);
group.add(d1);
duration.unsafeSubscribe(d1);
R result = resultSelector.call(args, window);
List rightMapValues;
synchronized (ResultManager.this) {
rightMapValues = new ArrayList(rightMap.values());
}
subscriber.onNext(result);
for (T2 t2 : rightMapValues) {
subjSerial.onNext(t2);
}
} catch (Throwable t) {
Exceptions.throwOrReport(t, this);
}
}
@Override
public void onCompleted() {
List> list = null;
synchronized (ResultManager.this) {
leftDone = true;
if (rightDone) {
list = new ArrayList>(leftMap().values());
leftMap().clear();
rightMap.clear();
}
}
complete(list);
}
@Override
public void onError(Throwable e) {
errorAll(e);
}
}
/** Observe the right source. */
final class RightObserver extends Subscriber {
@Override
public void onNext(T2 args) {
try {
int id;
synchronized (ResultManager.this) {
id = rightIds++;
rightMap.put(id, args);
}
Observable duration = rightDuration.call(args);
Subscriber d2 = new RightDurationObserver(id);
group.add(d2);
duration.unsafeSubscribe(d2);
List> list;
synchronized (ResultManager.this) {
list = new ArrayList>(leftMap().values());
}
for (Observer o : list) {
o.onNext(args);
}
} catch (Throwable t) {
Exceptions.throwOrReport(t, this);
}
}
@Override
public void onCompleted() {
List> list = null;
synchronized (ResultManager.this) {
rightDone = true;
if (leftDone) {
list = new ArrayList>(leftMap().values());
leftMap().clear();
rightMap.clear();
}
}
complete(list);
}
@Override
public void onError(Throwable e) {
errorAll(e);
}
}
/** Observe left duration and apply termination. */
final class LeftDurationObserver extends Subscriber {
final int id;
boolean once = true;
public LeftDurationObserver(int id) {
this.id = id;
}
@Override
public void onCompleted() {
if (once) {
once = false;
Observer gr;
synchronized (ResultManager.this) {
gr = leftMap().remove(id);
}
if (gr != null) {
gr.onCompleted();
}
group.remove(this);
}
}
@Override
public void onError(Throwable e) {
errorMain(e);
}
@Override
public void onNext(D1 args) {
onCompleted();
}
}
/** Observe right duration and apply termination. */
final class RightDurationObserver extends Subscriber {
final int id;
boolean once = true;
public RightDurationObserver(int id) {
this.id = id;
}
@Override
public void onCompleted() {
if (once) {
once = false;
synchronized (ResultManager.this) {
rightMap.remove(id);
}
group.remove(this);
}
}
@Override
public void onError(Throwable e) {
errorMain(e);
}
@Override
public void onNext(D2 args) {
onCompleted();
}
}
}
/**
* The reference-counted window observable.
* Subscribes to the underlying Observable by using a reference-counted
* subscription.
*/
final static class WindowObservableFunc implements OnSubscribe {
final RefCountSubscription refCount;
final Observable underlying;
public WindowObservableFunc(Observable underlying, RefCountSubscription refCount) {
this.refCount = refCount;
this.underlying = underlying;
}
@Override
public void call(Subscriber t1) {
Subscription ref = refCount.get();
WindowSubscriber wo = new WindowSubscriber(t1, ref);
wo.add(ref);
underlying.unsafeSubscribe(wo);
}
/** Observe activities on the window. */
final class WindowSubscriber extends Subscriber {
final Subscriber subscriber;
private final Subscription ref;
public WindowSubscriber(Subscriber subscriber, Subscription ref) {
super(subscriber);
this.subscriber = subscriber;
this.ref = ref;
}
@Override
public void onNext(T args) {
subscriber.onNext(args);
}
@Override
public void onError(Throwable e) {
subscriber.onError(e);
ref.unsubscribe();
}
@Override
public void onCompleted() {
subscriber.onCompleted();
ref.unsubscribe();
}
}
}
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