/**
* 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.Iterator;
import org.reactivestreams.Subscriber;
import io.reactivex.Flowable;
import io.reactivex.annotations.Nullable;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.internal.fuseable.ConditionalSubscriber;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.BackpressureHelper;
public final class FlowableFromIterable<T> extends Flowable<T> {
final Iterable<? extends T> source;
public FlowableFromIterable(Iterable<? extends T> source) {
this.source = source;
}
@Override
public void subscribeActual(Subscriber<? super T> s) {
Iterator<? extends T> it;
try {
it = source.iterator();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
EmptySubscription.error(e, s);
return;
}
subscribe(s, it);
}
public static <T> void subscribe(Subscriber<? super T> s, Iterator<? extends T> it) {
boolean hasNext;
try {
hasNext = it.hasNext();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
EmptySubscription.error(e, s);
return;
}
if (!hasNext) {
EmptySubscription.complete(s);
return;
}
if (s instanceof ConditionalSubscriber) {
s.onSubscribe(new IteratorConditionalSubscription<T>(
(ConditionalSubscriber<? super T>)s, it));
} else {
s.onSubscribe(new IteratorSubscription<T>(s, it));
}
}
abstract static class BaseRangeSubscription<T> extends BasicQueueSubscription<T> {
private static final long serialVersionUID = -2252972430506210021L;
Iterator<? extends T> it;
volatile boolean cancelled;
boolean once;
BaseRangeSubscription(Iterator<? extends T> it) {
this.it = it;
}
@Override
public final int requestFusion(int mode) {
return mode & SYNC;
}
@Nullable
@Override
public final T poll() {
if (it == null) {
return null;
}
if (!once) {
once = true;
} else {
if (!it.hasNext()) {
return null;
}
}
return ObjectHelper.requireNonNull(it.next(), "Iterator.next() returned a null value");
}
@Override
public final boolean isEmpty() {
return it == null || !it.hasNext();
}
@Override
public final void clear() {
it = null;
}
@Override
public final void request(long n) {
if (SubscriptionHelper.validate(n)) {
if (BackpressureHelper.add(this, n) == 0L) {
if (n == Long.MAX_VALUE) {
fastPath();
} else {
slowPath(n);
}
}
}
}
@Override
public final void cancel() {
cancelled = true;
}
abstract void fastPath();
abstract void slowPath(long r);
}
static final class IteratorSubscription<T> extends BaseRangeSubscription<T> {
private static final long serialVersionUID = -6022804456014692607L;
final Subscriber<? super T> actual;
IteratorSubscription(Subscriber<? super T> actual, Iterator<? extends T> it) {
super(it);
this.actual = actual;
}
@Override
void fastPath() {
Iterator<? extends T> it = this.it;
Subscriber<? super T> a = actual;
for (;;) {
if (cancelled) {
return;
}
T t;
try {
t = it.next();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (cancelled) {
return;
}
if (t == null) {
a.onError(new NullPointerException("Iterator.next() returned a null value"));
return;
} else {
a.onNext(t);
}
if (cancelled) {
return;
}
boolean b;
try {
b = it.hasNext();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (!b) {
if (!cancelled) {
a.onComplete();
}
return;
}
}
}
@Override
void slowPath(long r) {
long e = 0L;
Iterator<? extends T> it = this.it;
Subscriber<? super T> a = actual;
for (;;) {
while (e != r) {
if (cancelled) {
return;
}
T t;
try {
t = it.next();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (cancelled) {
return;
}
if (t == null) {
a.onError(new NullPointerException("Iterator.next() returned a null value"));
return;
} else {
a.onNext(t);
}
if (cancelled) {
return;
}
boolean b;
try {
b = it.hasNext();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (!b) {
if (!cancelled) {
a.onComplete();
}
return;
}
e++;
}
r = get();
if (e == r) {
r = addAndGet(-e);
if (r == 0L) {
return;
}
e = 0L;
}
}
}
}
static final class IteratorConditionalSubscription<T> extends BaseRangeSubscription<T> {
private static final long serialVersionUID = -6022804456014692607L;
final ConditionalSubscriber<? super T> actual;
IteratorConditionalSubscription(ConditionalSubscriber<? super T> actual, Iterator<? extends T> it) {
super(it);
this.actual = actual;
}
@Override
void fastPath() {
Iterator<? extends T> it = this.it;
ConditionalSubscriber<? super T> a = actual;
for (;;) {
if (cancelled) {
return;
}
T t;
try {
t = it.next();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (cancelled) {
return;
}
if (t == null) {
a.onError(new NullPointerException("Iterator.next() returned a null value"));
return;
} else {
a.tryOnNext(t);
}
if (cancelled) {
return;
}
boolean b;
try {
b = it.hasNext();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (!b) {
if (!cancelled) {
a.onComplete();
}
return;
}
}
}
@Override
void slowPath(long r) {
long e = 0L;
Iterator<? extends T> it = this.it;
ConditionalSubscriber<? super T> a = actual;
for (;;) {
while (e != r) {
if (cancelled) {
return;
}
T t;
try {
t = it.next();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (cancelled) {
return;
}
boolean b;
if (t == null) {
a.onError(new NullPointerException("Iterator.next() returned a null value"));
return;
} else {
b = a.tryOnNext(t);
}
if (cancelled) {
return;
}
boolean hasNext;
try {
hasNext = it.hasNext();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
a.onError(ex);
return;
}
if (!hasNext) {
if (!cancelled) {
a.onComplete();
}
return;
}
if (b) {
e++;
}
}
r = get();
if (e == r) {
r = addAndGet(-e);
if (r == 0L) {
return;
}
e = 0L;
}
}
}
}
}