io.reactivex.internal.operators.flowable.FlowableOnBackpressureBuffer Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rxjava Show documentation
Show all versions of rxjava Show documentation
Reactive Extensions for Java
/**
* 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.annotations.Nullable;
import io.reactivex.exceptions.*;
import io.reactivex.functions.Action;
import io.reactivex.internal.fuseable.SimplePlainQueue;
import io.reactivex.internal.queue.*;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.BackpressureHelper;
public final class FlowableOnBackpressureBuffer extends AbstractFlowableWithUpstream {
final int bufferSize;
final boolean unbounded;
final boolean delayError;
final Action onOverflow;
public FlowableOnBackpressureBuffer(Flowable source, int bufferSize, boolean unbounded,
boolean delayError, Action onOverflow) {
super(source);
this.bufferSize = bufferSize;
this.unbounded = unbounded;
this.delayError = delayError;
this.onOverflow = onOverflow;
}
@Override
protected void subscribeActual(Subscriber s) {
source.subscribe(new BackpressureBufferSubscriber(s, bufferSize, unbounded, delayError, onOverflow));
}
static final class BackpressureBufferSubscriber extends BasicIntQueueSubscription implements FlowableSubscriber {
private static final long serialVersionUID = -2514538129242366402L;
final Subscriber downstream;
final SimplePlainQueue queue;
final boolean delayError;
final Action onOverflow;
Subscription upstream;
volatile boolean cancelled;
volatile boolean done;
Throwable error;
final AtomicLong requested = new AtomicLong();
boolean outputFused;
BackpressureBufferSubscriber(Subscriber actual, int bufferSize,
boolean unbounded, boolean delayError, Action onOverflow) {
this.downstream = actual;
this.onOverflow = onOverflow;
this.delayError = delayError;
SimplePlainQueue q;
if (unbounded) {
q = new SpscLinkedArrayQueue(bufferSize);
} else {
q = new SpscArrayQueue(bufferSize);
}
this.queue = q;
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.upstream, s)) {
this.upstream = s;
downstream.onSubscribe(this);
s.request(Long.MAX_VALUE);
}
}
@Override
public void onNext(T t) {
if (!queue.offer(t)) {
upstream.cancel();
MissingBackpressureException ex = new MissingBackpressureException("Buffer is full");
try {
onOverflow.run();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
ex.initCause(e);
}
onError(ex);
return;
}
if (outputFused) {
downstream.onNext(null);
} else {
drain();
}
}
@Override
public void onError(Throwable t) {
error = t;
done = true;
if (outputFused) {
downstream.onError(t);
} else {
drain();
}
}
@Override
public void onComplete() {
done = true;
if (outputFused) {
downstream.onComplete();
} else {
drain();
}
}
@Override
public void request(long n) {
if (!outputFused) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
drain();
}
}
}
@Override
public void cancel() {
if (!cancelled) {
cancelled = true;
upstream.cancel();
if (!outputFused && getAndIncrement() == 0) {
queue.clear();
}
}
}
void drain() {
if (getAndIncrement() == 0) {
int missed = 1;
final SimplePlainQueue q = queue;
final Subscriber a = downstream;
for (;;) {
if (checkTerminated(done, q.isEmpty(), a)) {
return;
}
long r = requested.get();
long e = 0L;
while (e != r) {
boolean d = done;
T v = q.poll();
boolean empty = v == null;
if (checkTerminated(d, empty, a)) {
return;
}
if (empty) {
break;
}
a.onNext(v);
e++;
}
if (e == r) {
boolean d = done;
boolean empty = q.isEmpty();
if (checkTerminated(d, empty, a)) {
return;
}
}
if (e != 0L) {
if (r != Long.MAX_VALUE) {
requested.addAndGet(-e);
}
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
}
boolean checkTerminated(boolean d, boolean empty, Subscriber a) {
if (cancelled) {
queue.clear();
return true;
}
if (d) {
if (delayError) {
if (empty) {
Throwable e = error;
if (e != null) {
a.onError(e);
} else {
a.onComplete();
}
return true;
}
} else {
Throwable e = error;
if (e != null) {
queue.clear();
a.onError(e);
return true;
} else
if (empty) {
a.onComplete();
return true;
}
}
}
return false;
}
@Override
public int requestFusion(int mode) {
if ((mode & ASYNC) != 0) {
outputFused = true;
return ASYNC;
}
return NONE;
}
@Nullable
@Override
public T poll() throws Exception {
return queue.poll();
}
@Override
public void clear() {
queue.clear();
}
@Override
public boolean isEmpty() {
return queue.isEmpty();
}
}
}