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rxjava2-extensions developed by David Karnok
/*
* Copyright 2016-2018 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.string;
import java.util.concurrent.atomic.*;
import java.util.regex.Pattern;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.SpscArrayQueue;
import io.reactivex.internal.subscriptions.SubscriptionHelper;
import io.reactivex.internal.util.BackpressureHelper;
import io.reactivex.plugins.RxJavaPlugins;
/**
* Consider a sequence of CharSequence as one and split it based on
* a pattern.
*
* @since 0.13.0
*/
final class FlowableSplit extends Flowable implements FlowableTransformer {
final Publisher source;
final Pattern pattern;
final int bufferSize;
FlowableSplit(Publisher source, Pattern pattern, int bufferSize) {
this.source = source;
this.pattern = pattern;
this.bufferSize = bufferSize;
}
@Override
public Publisher apply(Flowable upstream) {
return new FlowableSplit(upstream, pattern, bufferSize);
}
@Override
protected void subscribeActual(Subscriber s) {
source.subscribe(new SplitSubscriber(s, pattern, bufferSize));
}
static final class SplitSubscriber
extends AtomicInteger
implements ConditionalSubscriber, Subscription {
static final String[] EMPTY = new String[0];
private static final long serialVersionUID = -5022617259701794064L;
final Subscriber actual;
final Pattern pattern;
final SimplePlainQueue queue;
final AtomicLong requested;
final int bufferSize;
final int limit;
Subscription s;
volatile boolean cancelled;
String leftOver;
String[] current;
int index;
int produced;
volatile boolean done;
Throwable error;
int empty;
SplitSubscriber(Subscriber actual, Pattern pattern, int bufferSize) {
this.actual = actual;
this.pattern = pattern;
this.bufferSize = bufferSize;
this.limit = bufferSize - (bufferSize >> 2);
this.queue = new SpscArrayQueue(bufferSize);
this.requested = new AtomicLong();
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
drain();
}
}
@Override
public void cancel() {
cancelled = true;
s.cancel();
if (getAndIncrement() == 0) {
current = null;
queue.clear();
}
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.s, s)) {
this.s = s;
actual.onSubscribe(this);
s.request(bufferSize);
}
}
@Override
public void onNext(String t) {
if (!tryOnNext(t)) {
s.request(1);
}
}
@Override
public boolean tryOnNext(String t) {
String lo = leftOver;
String[] a;
try {
if (lo == null || lo.isEmpty()) {
a = pattern.split(t, -1);
} else {
a = pattern.split(lo + t, -1);
}
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
this.s.cancel();
onError(ex);
return true;
}
if (a.length == 0) {
leftOver = null;
return false;
} else
if (a.length == 1) {
leftOver = a[0];
return false;
}
leftOver = a[a.length - 1];
queue.offer(a);
drain();
return true;
}
@Override
public void onError(Throwable t) {
if (done) {
RxJavaPlugins.onError(t);
return;
}
String lo = leftOver;
if (lo != null && !lo.isEmpty()) {
leftOver = null;
queue.offer(new String[] { lo, null });
}
error = t;
done = true;
drain();
}
@Override
public void onComplete() {
if (!done) {
done = true;
String lo = leftOver;
if (lo != null && !lo.isEmpty()) {
leftOver = null;
queue.offer(new String[] { lo, null });
}
drain();
}
}
void drain() {
if (getAndIncrement() != 0) {
return;
}
SimplePlainQueue q = queue;
int missed = 1;
int consumed = produced;
String[] array = current;
int idx = index;
int emptyCount = empty;
Subscriber a = actual;
for (;;) {
long r = requested.get();
long e = 0;
while (e != r) {
if (cancelled) {
current = null;
q.clear();
return;
}
boolean d = done;
if (array == null) {
array = q.poll();
if (array != null) {
current = array;
if (++consumed == limit) {
consumed = 0;
s.request(limit);
}
}
}
boolean empty = array == null;
if (d && empty) {
current = null;
Throwable ex = error;
if (ex != null) {
a.onError(ex);
} else {
a.onComplete();
}
return;
}
if (empty) {
break;
}
if (array.length == idx + 1) {
array = null;
current = null;
idx = 0;
continue;
}
String v = array[idx];
if (v.isEmpty()) {
emptyCount++;
idx++;
} else {
while (emptyCount != 0 && e != r) {
if (cancelled) {
current = null;
q.clear();
return;
}
a.onNext("");
e++;
emptyCount--;
}
if (e != r && emptyCount == 0) {
a.onNext(v);
e++;
idx++;
}
}
}
if (e == r) {
if (cancelled) {
current = null;
q.clear();
return;
}
boolean d = done;
if (array == null) {
array = q.poll();
if (array != null) {
current = array;
if (++consumed == limit) {
consumed = 0;
s.request(limit);
}
}
}
boolean empty = array == null;
if (d && empty) {
current = null;
Throwable ex = error;
if (ex != null) {
a.onError(ex);
} else {
a.onComplete();
}
return;
}
}
if (e != 0L) {
BackpressureHelper.produced(requested, e);
}
empty = emptyCount;
produced = consumed;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
}
}