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rxjava2-extensions developed by David Karnok
/*
* Copyright 2016-2017 David Karnok
*
* 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 hu.akarnokd.rxjava2.operators;
import org.reactivestreams.Subscriber;
import io.reactivex.Flowable;
import io.reactivex.internal.fuseable.ConditionalSubscriber;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.BackpressureHelper;
/**
* Repeats a scalar value indefinitely.
*
* @param the value type
*
* @since 0.14.2
*/
final class FlowableRepeatScalar extends Flowable {
final T value;
FlowableRepeatScalar(T value) {
this.value = value;
}
@Override
protected void subscribeActual(Subscriber s) {
if (s instanceof ConditionalSubscriber) {
s.onSubscribe(new RepeatScalarConditionalSubscription((ConditionalSubscriber)s, value));
} else {
s.onSubscribe(new RepeatScalarSubscription(s, value));
}
}
static final class RepeatScalarSubscription extends BasicQueueSubscription {
private static final long serialVersionUID = -231033913007168200L;
final Subscriber actual;
T value;
volatile boolean cancelled;
RepeatScalarSubscription(Subscriber actual, T value) {
this.actual = actual;
this.value = value;
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
if (BackpressureHelper.add(this, n) == 0) {
if (n == Long.MAX_VALUE) {
fastpath();
} else {
slowpath(n);
}
}
}
}
void fastpath() {
T v = value;
for (;;) {
if (cancelled) {
break;
}
actual.onNext(v);
}
}
void slowpath(long r) {
T v = value;
long e = 0L;
for (;;) {
while (e != r) {
if (cancelled) {
return;
}
actual.onNext(v);
e++;
}
if (cancelled) {
return;
}
r = get();
if (e == r) {
r = addAndGet(-e);
if (r == 0L) {
break;
}
e = 0L;
}
}
}
@Override
public void cancel() {
cancelled = true;
}
@Override
public int requestFusion(int mode) {
return mode & SYNC;
}
@Override
public T poll() throws Exception {
return value;
}
@Override
public boolean isEmpty() {
return value == null;
}
@Override
public void clear() {
value = null;
}
}
static final class RepeatScalarConditionalSubscription extends BasicQueueSubscription {
private static final long serialVersionUID = -231033913007168200L;
final ConditionalSubscriber actual;
T value;
volatile boolean cancelled;
RepeatScalarConditionalSubscription(ConditionalSubscriber actual, T value) {
this.actual = actual;
this.value = value;
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
if (BackpressureHelper.add(this, n) == 0) {
if (n == Long.MAX_VALUE) {
fastpath();
} else {
slowpath(n);
}
}
}
}
void fastpath() {
T v = value;
for (;;) {
if (cancelled) {
break;
}
actual.tryOnNext(v);
}
}
void slowpath(long r) {
T v = value;
long e = 0L;
for (;;) {
while (e != r) {
if (cancelled) {
return;
}
if (actual.tryOnNext(v)) {
e++;
}
}
if (cancelled) {
return;
}
r = get();
if (e == r) {
r = addAndGet(-e);
if (r == 0L) {
break;
}
e = 0L;
}
}
}
@Override
public void cancel() {
cancelled = true;
}
@Override
public int requestFusion(int mode) {
return mode & SYNC;
}
@Override
public T poll() throws Exception {
return value;
}
@Override
public boolean isEmpty() {
return value == null;
}
@Override
public void clear() {
value = null;
}
}
}