/**
* 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.flowable;
import java.util.concurrent.atomic.AtomicLong;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.Scheduler.Worker;
import io.reactivex.annotations.Nullable;
import io.reactivex.exceptions.*;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.SpscArrayQueue;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.BackpressureHelper;
import io.reactivex.plugins.RxJavaPlugins;
public final class FlowableObserveOn<T> extends AbstractFlowableWithUpstream<T, T> {
final Scheduler scheduler;
final boolean delayError;
final int prefetch;
public FlowableObserveOn(
Flowable<T> source,
Scheduler scheduler,
boolean delayError,
int prefetch) {
super(source);
this.scheduler = scheduler;
this.delayError = delayError;
this.prefetch = prefetch;
}
@Override
public void subscribeActual(Subscriber<? super T> s) {
Worker worker = scheduler.createWorker();
if (s instanceof ConditionalSubscriber) {
source.subscribe(new ObserveOnConditionalSubscriber<T>(
(ConditionalSubscriber<? super T>) s, worker, delayError, prefetch));
} else {
source.subscribe(new ObserveOnSubscriber<T>(s, worker, delayError, prefetch));
}
}
abstract static class BaseObserveOnSubscriber<T>
extends BasicIntQueueSubscription<T>
implements FlowableSubscriber<T>, Runnable {
private static final long serialVersionUID = -8241002408341274697L;
final Worker worker;
final boolean delayError;
final int prefetch;
final int limit;
final AtomicLong requested;
Subscription s;
SimpleQueue<T> queue;
volatile boolean cancelled;
volatile boolean done;
Throwable error;
int sourceMode;
long produced;
boolean outputFused;
BaseObserveOnSubscriber(
Worker worker,
boolean delayError,
int prefetch) {
this.worker = worker;
this.delayError = delayError;
this.prefetch = prefetch;
this.requested = new AtomicLong();
this.limit = prefetch - (prefetch >> 2);
}
@Override
public final void onNext(T t) {
if (done) {
return;
}
if (sourceMode == ASYNC) {
trySchedule();
return;
}
if (!queue.offer(t)) {
s.cancel();
error = new MissingBackpressureException("Queue is full?!");
done = true;
}
trySchedule();
}
@Override
public final void onError(Throwable t) {
if (done) {
RxJavaPlugins.onError(t);
return;
}
error = t;
done = true;
trySchedule();
}
@Override
public final void onComplete() {
if (!done) {
done = true;
trySchedule();
}
}
@Override
public final void request(long n) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
trySchedule();
}
}
@Override
public final void cancel() {
if (cancelled) {
return;
}
cancelled = true;
s.cancel();
worker.dispose();
if (getAndIncrement() == 0) {
queue.clear();
}
}
final void trySchedule() {
if (getAndIncrement() != 0) {
return;
}
worker.schedule(this);
}
@Override
public final void run() {
if (outputFused) {
runBackfused();
} else if (sourceMode == SYNC) {
runSync();
} else {
runAsync();
}
}
abstract void runBackfused();
abstract void runSync();
abstract void runAsync();
final boolean checkTerminated(boolean d, boolean empty, Subscriber<?> a) {
if (cancelled) {
clear();
return true;
}
if (d) {
if (delayError) {
if (empty) {
Throwable e = error;
if (e != null) {
a.onError(e);
} else {
a.onComplete();
}
worker.dispose();
return true;
}
} else {
Throwable e = error;
if (e != null) {
clear();
a.onError(e);
worker.dispose();
return true;
} else
if (empty) {
a.onComplete();
worker.dispose();
return true;
}
}
}
return false;
}
@Override
public final int requestFusion(int requestedMode) {
if ((requestedMode & ASYNC) != 0) {
outputFused = true;
return ASYNC;
}
return NONE;
}
@Override
public final void clear() {
queue.clear();
}
@Override
public final boolean isEmpty() {
return queue.isEmpty();
}
}
static final class ObserveOnSubscriber<T> extends BaseObserveOnSubscriber<T>
implements FlowableSubscriber<T> {
private static final long serialVersionUID = -4547113800637756442L;
final Subscriber<? super T> actual;
ObserveOnSubscriber(
Subscriber<? super T> actual,
Worker worker,
boolean delayError,
int prefetch) {
super(worker, delayError, prefetch);
this.actual = actual;
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.s, s)) {
this.s = s;
if (s instanceof QueueSubscription) {
@SuppressWarnings("unchecked")
QueueSubscription<T> f = (QueueSubscription<T>) s;
int m = f.requestFusion(ANY | BOUNDARY);
if (m == SYNC) {
sourceMode = SYNC;
queue = f;
done = true;
actual.onSubscribe(this);
return;
} else
if (m == ASYNC) {
sourceMode = ASYNC;
queue = f;
actual.onSubscribe(this);
s.request(prefetch);
return;
}
}
queue = new SpscArrayQueue<T>(prefetch);
actual.onSubscribe(this);
s.request(prefetch);
}
}
@Override
void runSync() {
int missed = 1;
final Subscriber<? super T> a = actual;
final SimpleQueue<T> q = queue;
long e = produced;
for (;;) {
long r = requested.get();
while (e != r) {
T v;
try {
v = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
s.cancel();
a.onError(ex);
worker.dispose();
return;
}
if (cancelled) {
return;
}
if (v == null) {
a.onComplete();
worker.dispose();
return;
}
a.onNext(v);
e++;
}
if (cancelled) {
return;
}
if (q.isEmpty()) {
a.onComplete();
worker.dispose();
return;
}
int w = get();
if (missed == w) {
produced = e;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
} else {
missed = w;
}
}
}
@Override
void runAsync() {
int missed = 1;
final Subscriber<? super T> a = actual;
final SimpleQueue<T> q = queue;
long e = produced;
for (;;) {
long r = requested.get();
while (e != r) {
boolean d = done;
T v;
try {
v = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
s.cancel();
q.clear();
a.onError(ex);
worker.dispose();
return;
}
boolean empty = v == null;
if (checkTerminated(d, empty, a)) {
return;
}
if (empty) {
break;
}
a.onNext(v);
e++;
if (e == limit) {
if (r != Long.MAX_VALUE) {
r = requested.addAndGet(-e);
}
s.request(e);
e = 0L;
}
}
if (e == r && checkTerminated(done, q.isEmpty(), a)) {
return;
}
int w = get();
if (missed == w) {
produced = e;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
} else {
missed = w;
}
}
}
@Override
void runBackfused() {
int missed = 1;
for (;;) {
if (cancelled) {
return;
}
boolean d = done;
actual.onNext(null);
if (d) {
Throwable e = error;
if (e != null) {
actual.onError(e);
} else {
actual.onComplete();
}
worker.dispose();
return;
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
@Nullable
@Override
public T poll() throws Exception {
T v = queue.poll();
if (v != null && sourceMode != SYNC) {
long p = produced + 1;
if (p == limit) {
produced = 0;
s.request(p);
} else {
produced = p;
}
}
return v;
}
}
static final class ObserveOnConditionalSubscriber<T>
extends BaseObserveOnSubscriber<T> {
private static final long serialVersionUID = 644624475404284533L;
final ConditionalSubscriber<? super T> actual;
long consumed;
ObserveOnConditionalSubscriber(
ConditionalSubscriber<? super T> actual,
Worker worker,
boolean delayError,
int prefetch) {
super(worker, delayError, prefetch);
this.actual = actual;
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.s, s)) {
this.s = s;
if (s instanceof QueueSubscription) {
@SuppressWarnings("unchecked")
QueueSubscription<T> f = (QueueSubscription<T>) s;
int m = f.requestFusion(ANY | BOUNDARY);
if (m == SYNC) {
sourceMode = SYNC;
queue = f;
done = true;
actual.onSubscribe(this);
return;
} else
if (m == ASYNC) {
sourceMode = ASYNC;
queue = f;
actual.onSubscribe(this);
s.request(prefetch);
return;
}
}
queue = new SpscArrayQueue<T>(prefetch);
actual.onSubscribe(this);
s.request(prefetch);
}
}
@Override
void runSync() {
int missed = 1;
final ConditionalSubscriber<? super T> a = actual;
final SimpleQueue<T> q = queue;
long e = produced;
for (;;) {
long r = requested.get();
while (e != r) {
T v;
try {
v = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
s.cancel();
a.onError(ex);
worker.dispose();
return;
}
if (cancelled) {
return;
}
if (v == null) {
a.onComplete();
worker.dispose();
return;
}
if (a.tryOnNext(v)) {
e++;
}
}
if (cancelled) {
return;
}
if (q.isEmpty()) {
a.onComplete();
worker.dispose();
return;
}
int w = get();
if (missed == w) {
produced = e;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
} else {
missed = w;
}
}
}
@Override
void runAsync() {
int missed = 1;
final ConditionalSubscriber<? super T> a = actual;
final SimpleQueue<T> q = queue;
long emitted = produced;
long polled = consumed;
for (;;) {
long r = requested.get();
while (emitted != r) {
boolean d = done;
T v;
try {
v = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
s.cancel();
q.clear();
a.onError(ex);
worker.dispose();
return;
}
boolean empty = v == null;
if (checkTerminated(d, empty, a)) {
return;
}
if (empty) {
break;
}
if (a.tryOnNext(v)) {
emitted++;
}
polled++;
if (polled == limit) {
s.request(polled);
polled = 0L;
}
}
if (emitted == r && checkTerminated(done, q.isEmpty(), a)) {
return;
}
int w = get();
if (missed == w) {
produced = emitted;
consumed = polled;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
} else {
missed = w;
}
}
}
@Override
void runBackfused() {
int missed = 1;
for (;;) {
if (cancelled) {
return;
}
boolean d = done;
actual.onNext(null);
if (d) {
Throwable e = error;
if (e != null) {
actual.onError(e);
} else {
actual.onComplete();
}
worker.dispose();
return;
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
@Nullable
@Override
public T poll() throws Exception {
T v = queue.poll();
if (v != null && sourceMode != SYNC) {
long p = consumed + 1;
if (p == limit) {
consumed = 0;
s.request(p);
} else {
consumed = p;
}
}
return v;
}
}
}