/**
* 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.
TimeoutException;
import java.util.concurrent.atomic.
AtomicLong;
import rx.*;
import rx.exceptions.
Exceptions;
import rx.functions.
Func1;
import rx.internal.operators.
OnSubscribeTimeoutTimedWithFallback.
FallbackSubscriber;
import rx.internal.producers.
ProducerArbiter;
import rx.internal.subscriptions.
SequentialSubscription;
import rx.plugins.
RxJavaHooks;
/**
* Switches to the fallback Observable if: the first upstream item doesn't arrive before
* the first timeout Observable signals an item or completes; or the Observable generated from
* the previous upstream item signals its item or completes before the upstream signals the next item
* of its own.
*
* @param <T> the input and output value type
* @param <U> the value type of the first timeout Observable
* @param <V> the value type of the item-based timeout Observable
*
* @since 1.3.3
*/
public final class
OnSubscribeTimeoutSelectorWithFallback<T, U, V> implements
Observable.
OnSubscribe<T> {
final
Observable<T>
source;
final
Observable<U>
firstTimeoutIndicator;
final
Func1<? super T, ? extends
Observable<V>>
itemTimeoutIndicator;
final
Observable<? extends T>
fallback;
public
OnSubscribeTimeoutSelectorWithFallback(
Observable<T>
source,
Observable<U>
firstTimeoutIndicator,
Func1<? super T, ? extends
Observable<V>>
itemTimeoutIndicator,
Observable<? extends T>
fallback) {
this.
source =
source;
this.
firstTimeoutIndicator =
firstTimeoutIndicator;
this.
itemTimeoutIndicator =
itemTimeoutIndicator;
this.
fallback =
fallback;
}
@
Override
public void
call(
Subscriber<? super T>
t) {
TimeoutMainSubscriber<T>
parent = new
TimeoutMainSubscriber<T>(
t,
itemTimeoutIndicator,
fallback);
t.
add(
parent.
upstream);
t.
setProducer(
parent.
arbiter);
parent.
startFirst(
firstTimeoutIndicator);
source.
subscribe(
parent);
}
static final class
TimeoutMainSubscriber<T> extends
Subscriber<T> {
final
Subscriber<? super T>
actual;
final
Func1<? super T, ? extends
Observable<?>>
itemTimeoutIndicator;
final
Observable<? extends T>
fallback;
final
ProducerArbiter arbiter;
final
AtomicLong index;
final
SequentialSubscription task;
final
SequentialSubscription upstream;
long
consumed;
TimeoutMainSubscriber(
Subscriber<? super T>
actual,
Func1<? super T, ? extends
Observable<?>>
itemTimeoutIndicator,
Observable<? extends T>
fallback) {
this.
actual =
actual;
this.
itemTimeoutIndicator =
itemTimeoutIndicator;
this.
fallback =
fallback;
this.
arbiter = new
ProducerArbiter();
this.
index = new
AtomicLong();
this.
task = new
SequentialSubscription();
this.
upstream = new
SequentialSubscription(this);
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();
}
actual.
onNext(
t);
consumed++;
Observable<?>
timeoutObservable;
try {
timeoutObservable =
itemTimeoutIndicator.
call(
t);
if (
timeoutObservable == null) {
throw new
NullPointerException("The itemTimeoutIndicator returned a null Observable");
}
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
unsubscribe();
index.
getAndSet(
Long.
MAX_VALUE);
actual.
onError(
ex);
return;
}
TimeoutConsumer tc = new
TimeoutConsumer(
idx + 1);
if (
task.
replace(
tc)) {
timeoutObservable.
subscribe(
tc);
}
}
void
startFirst(
Observable<?>
firstTimeoutIndicator) {
if (
firstTimeoutIndicator != null) {
TimeoutConsumer tc = new
TimeoutConsumer(0L);
if (
task.
replace(
tc)) {
firstTimeoutIndicator.
subscribe(
tc);
}
}
}
@
Override
public void
onError(
Throwable e) {
if (
index.
getAndSet(
Long.
MAX_VALUE) !=
Long.
MAX_VALUE) {
task.
unsubscribe();
actual.
onError(
e);
} else {
RxJavaHooks.
onError(
e);
}
}
@
Override
public void
onCompleted() {
if (
index.
getAndSet(
Long.
MAX_VALUE) !=
Long.
MAX_VALUE) {
task.
unsubscribe();
actual.
onCompleted();
}
}
@
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);
}
}
}
void
onTimeoutError(long
idx,
Throwable ex) {
if (
index.
compareAndSet(
idx,
Long.
MAX_VALUE)) {
unsubscribe();
actual.
onError(
ex);
} else {
RxJavaHooks.
onError(
ex);
}
}
final class
TimeoutConsumer extends
Subscriber<
Object> {
final long
idx;
boolean
done;
TimeoutConsumer(long
idx) {
this.
idx =
idx;
}
@
Override
public void
onNext(
Object t) {
if (!
done) {
done = true;
unsubscribe();
onTimeout(
idx);
}
}
@
Override
public void
onError(
Throwable e) {
if (!
done) {
done = true;
onTimeoutError(
idx,
e);
} else {
RxJavaHooks.
onError(
e);
}
}
@
Override
public void
onCompleted() {
if (!
done) {
done = true;
onTimeout(
idx);
}
}
}
}
}