/**
* 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.concurrent.*;
import java.util.concurrent.atomic.
AtomicLong;
import rx.*;
import rx.
Scheduler.
Worker;
import rx.functions.
Action0;
import rx.internal.producers.
ProducerArbiter;
import rx.internal.subscriptions.
SequentialSubscription;
import rx.plugins.
RxJavaHooks;
/**
* Switches to consuming a fallback Observable if the main source doesn't signal an onNext event
* within the given time frame after subscription or the previous onNext event.
*
* @param <T> the value type
* @since 1.3.3
*/
public final class
OnSubscribeTimeoutTimedWithFallback<T> implements
Observable.
OnSubscribe<T> {
final
Observable<T>
source;
final long
timeout;
final
TimeUnit unit;
final
Scheduler scheduler;
final
Observable<? extends T>
fallback;
public
OnSubscribeTimeoutTimedWithFallback(
Observable<T>
source, long
timeout,
TimeUnit unit,
Scheduler scheduler,
Observable<? extends T>
fallback) {
this.
source =
source;
this.
timeout =
timeout;
this.
unit =
unit;
this.
scheduler =
scheduler;
this.
fallback =
fallback;
}
@
Override
public void
call(
Subscriber<? super T>
t) {
TimeoutMainSubscriber<T>
parent = new
TimeoutMainSubscriber<T>(
t,
timeout,
unit,
scheduler.
createWorker(),
fallback);
t.
add(
parent.
upstream);
t.
setProducer(
parent.
arbiter);
parent.
startTimeout(0L);
source.
subscribe(
parent);
}
static final class
TimeoutMainSubscriber<T> extends
Subscriber<T> {
final
Subscriber<? super T>
actual;
final long
timeout;
final
TimeUnit unit;
final
Worker worker;
final
Observable<? extends T>
fallback;
final
ProducerArbiter arbiter;
final
AtomicLong index;
final
SequentialSubscription task;
final
SequentialSubscription upstream;
long
consumed;
TimeoutMainSubscriber(
Subscriber<? super T>
actual, long
timeout,
TimeUnit unit,
Worker worker,
Observable<? extends T>
fallback) {
this.
actual =
actual;
this.
timeout =
timeout;
this.
unit =
unit;
this.
worker =
worker;
this.
fallback =
fallback;
this.
arbiter = new
ProducerArbiter();
this.
index = new
AtomicLong();
this.
task = new
SequentialSubscription();
this.
upstream = new
SequentialSubscription(this);
this.
add(
worker);
this.
add(
task);
}
@
Override
public void
onNext(T
t) {
long
idx =
index.
get();
if (
idx ==
Long.
MAX_VALUE || !
index.
compareAndSet(
idx,
idx + 1)) {
return;
}
Subscription s =
task.
get();
if (
s != null) {
s.
unsubscribe();
}
consumed++;
actual.
onNext(
t);
startTimeout(
idx + 1);
}
void
startTimeout(long
nextIdx) {
task.
replace(
worker.
schedule(new
TimeoutTask(
nextIdx),
timeout,
unit));
}
@
Override
public void
onError(
Throwable e) {
if (
index.
getAndSet(
Long.
MAX_VALUE) !=
Long.
MAX_VALUE) {
task.
unsubscribe();
actual.
onError(
e);
worker.
unsubscribe();
} else {
RxJavaHooks.
onError(
e);
}
}
@
Override
public void
onCompleted() {
if (
index.
getAndSet(
Long.
MAX_VALUE) !=
Long.
MAX_VALUE) {
task.
unsubscribe();
actual.
onCompleted();
worker.
unsubscribe();
}
}
@
Override
public void
setProducer(
Producer p) {
arbiter.
setProducer(
p);
}
void
onTimeout(long
idx) {
if (!
index.
compareAndSet(
idx,
Long.
MAX_VALUE)) {
return;
}
unsubscribe();
if (
fallback == null) {
actual.
onError(new
TimeoutException());
} else {
long
c =
consumed;
if (
c != 0L) {
arbiter.
produced(
c);
}
FallbackSubscriber<T>
fallbackSubscriber = new
FallbackSubscriber<T>(
actual,
arbiter);
if (
upstream.
replace(
fallbackSubscriber)) {
fallback.
subscribe(
fallbackSubscriber);
}
}
}
final class
TimeoutTask implements
Action0 {
final long
idx;
TimeoutTask(long
idx) {
this.
idx =
idx;
}
@
Override
public void
call() {
onTimeout(
idx);
}
}
}
static final class
FallbackSubscriber<T> extends
Subscriber<T> {
final
Subscriber<? super T>
actual;
final
ProducerArbiter arbiter;
FallbackSubscriber(
Subscriber<? super T>
actual,
ProducerArbiter arbiter) {
this.
actual =
actual;
this.
arbiter =
arbiter;
}
@
Override
public void
onNext(T
t) {
actual.
onNext(
t);
}
@
Override
public void
onError(
Throwable e) {
actual.
onError(
e);
}
@
Override
public void
onCompleted() {
actual.
onCompleted();
}
@
Override
public void
setProducer(
Producer p) {
arbiter.
setProducer(
p);
}
}
}