/**
* 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.observable;
import java.util.
Iterator;
import io.reactivex.*;
import io.reactivex.annotations.
Nullable;
import io.reactivex.exceptions.
Exceptions;
import io.reactivex.internal.disposables.
EmptyDisposable;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.internal.observers.
BasicQueueDisposable;
public final class
ObservableFromIterable<T> extends
Observable<T> {
final
Iterable<? extends T>
source;
public
ObservableFromIterable(
Iterable<? extends T>
source) {
this.
source =
source;
}
@
Override
public void
subscribeActual(
Observer<? super T>
observer) {
Iterator<? extends T>
it;
try {
it =
source.
iterator();
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
EmptyDisposable.
error(
e,
observer);
return;
}
boolean
hasNext;
try {
hasNext =
it.
hasNext();
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
EmptyDisposable.
error(
e,
observer);
return;
}
if (!
hasNext) {
EmptyDisposable.
complete(
observer);
return;
}
FromIterableDisposable<T>
d = new
FromIterableDisposable<T>(
observer,
it);
observer.
onSubscribe(
d);
if (!
d.
fusionMode) {
d.
run();
}
}
static final class
FromIterableDisposable<T> extends
BasicQueueDisposable<T> {
final
Observer<? super T>
downstream;
final
Iterator<? extends T>
it;
volatile boolean
disposed;
boolean
fusionMode;
boolean
done;
boolean
checkNext;
FromIterableDisposable(
Observer<? super T>
actual,
Iterator<? extends T>
it) {
this.
downstream =
actual;
this.
it =
it;
}
void
run() {
boolean
hasNext;
do {
if (
isDisposed()) {
return;
}
T
v;
try {
v =
ObjectHelper.
requireNonNull(
it.
next(), "The iterator returned a null value");
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
downstream.
onError(
e);
return;
}
downstream.
onNext(
v);
if (
isDisposed()) {
return;
}
try {
hasNext =
it.
hasNext();
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
downstream.
onError(
e);
return;
}
} while (
hasNext);
if (!
isDisposed()) {
downstream.
onComplete();
}
}
@
Override
public int
requestFusion(int
mode) {
if ((
mode &
SYNC) != 0) {
fusionMode = true;
return
SYNC;
}
return
NONE;
}
@
Nullable
@
Override
public T
poll() {
if (
done) {
return null;
}
if (
checkNext) {
if (!
it.
hasNext()) {
done = true;
return null;
}
} else {
checkNext = true;
}
return
ObjectHelper.
requireNonNull(
it.
next(), "The iterator returned a null value");
}
@
Override
public boolean
isEmpty() {
return
done;
}
@
Override
public void
clear() {
done = true;
}
@
Override
public void
dispose() {
disposed = true;
}
@
Override
public boolean
isDisposed() {
return
disposed;
}
}
}