/**
* 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.operators.observable;
import io.reactivex.internal.functions.ObjectHelper;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.*;
import io.reactivex.ObservableSource;
import io.reactivex.Observer;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.functions.Function;
import io.reactivex.internal.disposables.*;
import io.reactivex.internal.queue.SpscLinkedArrayQueue;
import io.reactivex.observables.GroupedObservable;
public final class ObservableGroupBy<T, K, V> extends AbstractObservableWithUpstream<T, GroupedObservable<K, V>> {
final Function<? super T, ? extends K> keySelector;
final Function<? super T, ? extends V> valueSelector;
final int bufferSize;
final boolean delayError;
public ObservableGroupBy(ObservableSource<T> source,
Function<? super T, ? extends K> keySelector, Function<? super T, ? extends V> valueSelector,
int bufferSize, boolean delayError) {
super(source);
this.keySelector = keySelector;
this.valueSelector = valueSelector;
this.bufferSize = bufferSize;
this.delayError = delayError;
}
@Override
public void subscribeActual(Observer<? super GroupedObservable<K, V>> t) {
source.subscribe(new GroupByObserver<T, K, V>(t, keySelector, valueSelector, bufferSize, delayError));
}
public static final class GroupByObserver<T, K, V> extends AtomicInteger implements Observer<T>, Disposable {
private static final long serialVersionUID = -3688291656102519502L;
final Observer<? super GroupedObservable<K, V>> actual;
final Function<? super T, ? extends K> keySelector;
final Function<? super T, ? extends V> valueSelector;
final int bufferSize;
final boolean delayError;
final Map<Object, GroupedUnicast<K, V>> groups;
static final Object NULL_KEY = new Object();
Disposable s;
final AtomicBoolean cancelled = new AtomicBoolean();
public GroupByObserver(Observer<? super GroupedObservable<K, V>> actual, Function<? super T, ? extends K> keySelector, Function<? super T, ? extends V> valueSelector, int bufferSize, boolean delayError) {
this.actual = actual;
this.keySelector = keySelector;
this.valueSelector = valueSelector;
this.bufferSize = bufferSize;
this.delayError = delayError;
this.groups = new ConcurrentHashMap<Object, GroupedUnicast<K, V>>();
this.lazySet(1);
}
@Override
public void onSubscribe(Disposable s) {
if (DisposableHelper.validate(this.s, s)) {
this.s = s;
actual.onSubscribe(this);
}
}
@Override
public void onNext(T t) {
K key;
try {
key = keySelector.apply(t);
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.dispose();
onError(e);
return;
}
Object mapKey = key != null ? key : NULL_KEY;
GroupedUnicast<K, V> group = groups.get(mapKey);
if (group == null) {
// if the main has been cancelled, stop creating groups
// and skip this value
if (cancelled.get()) {
return;
}
group = GroupedUnicast.createWith(key, bufferSize, this, delayError);
groups.put(mapKey, group);
getAndIncrement();
actual.onNext(group);
}
V v;
try {
v = ObjectHelper.requireNonNull(valueSelector.apply(t), "The value supplied is null");
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.dispose();
onError(e);
return;
}
group.onNext(v);
}
@Override
public void onError(Throwable t) {
List<GroupedUnicast<K, V>> list = new ArrayList<GroupedUnicast<K, V>>(groups.values());
groups.clear();
for (GroupedUnicast<K, V> e : list) {
e.onError(t);
}
actual.onError(t);
}
@Override
public void onComplete() {
List<GroupedUnicast<K, V>> list = new ArrayList<GroupedUnicast<K, V>>(groups.values());
groups.clear();
for (GroupedUnicast<K, V> e : list) {
e.onComplete();
}
actual.onComplete();
}
@Override
public void dispose() {
// cancelling the main source means we don't want any more groups
// but running groups still require new values
if (cancelled.compareAndSet(false, true)) {
if (decrementAndGet() == 0) {
s.dispose();
}
}
}
@Override
public boolean isDisposed() {
return cancelled.get();
}
public void cancel(K key) {
Object mapKey = key != null ? key : NULL_KEY;
groups.remove(mapKey);
if (decrementAndGet() == 0) {
s.dispose();
}
}
}
static final class GroupedUnicast<K, T> extends GroupedObservable<K, T> {
final State<T, K> state;
public static <T, K> GroupedUnicast<K, T> createWith(K key, int bufferSize, GroupByObserver<?, K, T> parent, boolean delayError) {
State<T, K> state = new State<T, K>(bufferSize, parent, key, delayError);
return new GroupedUnicast<K, T>(key, state);
}
protected GroupedUnicast(K key, State<T, K> state) {
super(key);
this.state = state;
}
@Override
protected void subscribeActual(Observer<? super T> observer) {
state.subscribe(observer);
}
public void onNext(T t) {
state.onNext(t);
}
public void onError(Throwable e) {
state.onError(e);
}
public void onComplete() {
state.onComplete();
}
}
static final class State<T, K> extends AtomicInteger implements Disposable, ObservableSource<T> {
private static final long serialVersionUID = -3852313036005250360L;
final K key;
final SpscLinkedArrayQueue<T> queue;
final GroupByObserver<?, K, T> parent;
final boolean delayError;
volatile boolean done;
Throwable error;
final AtomicBoolean cancelled = new AtomicBoolean();
final AtomicBoolean once = new AtomicBoolean();
final AtomicReference<Observer<? super T>> actual = new AtomicReference<Observer<? super T>>();
State(int bufferSize, GroupByObserver<?, K, T> parent, K key, boolean delayError) {
this.queue = new SpscLinkedArrayQueue<T>(bufferSize);
this.parent = parent;
this.key = key;
this.delayError = delayError;
}
@Override
public void dispose() {
if (cancelled.compareAndSet(false, true)) {
if (getAndIncrement() == 0) {
actual.lazySet(null);
parent.cancel(key);
}
}
}
@Override
public boolean isDisposed() {
return cancelled.get();
}
@Override
public void subscribe(Observer<? super T> s) {
if (once.compareAndSet(false, true)) {
s.onSubscribe(this);
actual.lazySet(s);
if (cancelled.get()) {
actual.lazySet(null);
} else {
drain();
}
} else {
EmptyDisposable.error(new IllegalStateException("Only one Observer allowed!"), s);
}
}
public void onNext(T t) {
queue.offer(t);
drain();
}
public void onError(Throwable e) {
error = e;
done = true;
drain();
}
public void onComplete() {
done = true;
drain();
}
void drain() {
if (getAndIncrement() != 0) {
return;
}
int missed = 1;
final SpscLinkedArrayQueue<T> q = queue;
final boolean delayError = this.delayError;
Observer<? super T> a = actual.get();
for (;;) {
if (a != null) {
for (;;) {
boolean d = done;
T v = q.poll();
boolean empty = v == null;
if (checkTerminated(d, empty, a, delayError)) {
return;
}
if (empty) {
break;
}
a.onNext(v);
}
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
if (a == null) {
a = actual.get();
}
}
}
boolean checkTerminated(boolean d, boolean empty, Observer<? super T> a, boolean delayError) {
if (cancelled.get()) {
queue.clear();
parent.cancel(key);
actual.lazySet(null);
return true;
}
if (d) {
if (delayError) {
if (empty) {
Throwable e = error;
actual.lazySet(null);
if (e != null) {
a.onError(e);
} else {
a.onComplete();
}
return true;
}
} else {
Throwable e = error;
if (e != null) {
queue.clear();
actual.lazySet(null);
a.onError(e);
return true;
} else
if (empty) {
actual.lazySet(null);
a.onComplete();
return true;
}
}
}
return false;
}
}
}