Skip to content

Commit 3e73b75

Browse files
abersnazeabersnaze
authored
Merge pull request #47 from akarnokd/SplitBackpressureFix
Reimplement split() with backpressure
2 parents d6d43ef + 47e0c48 commit 3e73b75

File tree

4 files changed

+464
-82
lines changed

4 files changed

+464
-82
lines changed

Diff for: ‎build.gradle

+1-1
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@ apply plugin: 'rxjava-project'
77
apply plugin: 'java'
88

99
dependencies {
10-
compile 'io.reactivex:rxjava:1.1.1'
10+
compile 'io.reactivex:rxjava:1.2.3'
1111
testCompile 'junit:junit-dep:4.10'
1212
testCompile 'org.mockito:mockito-core:1.8.5'
1313
}

Diff for: ‎src/main/java/rx/internal/operators/ObservableSplit.java

+337
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,337 @@
1+
/**
2+
* Copyright 2014 Netflix, Inc.
3+
*
4+
* Licensed under the Apache License, Version 2.0 (the "License");
5+
* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
7+
*
8+
* http://www.apache.org/licenses/LICENSE-2.0
9+
*
10+
* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
12+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
15+
*/
16+
17+
package rx.internal.operators;
18+
19+
import java.util.Queue;
20+
import java.util.concurrent.atomic.*;
21+
import java.util.regex.Pattern;
22+
23+
import rx.*;
24+
import rx.Observable.OnSubscribe;
25+
import rx.exceptions.Exceptions;
26+
import rx.internal.operators.BackpressureUtils;
27+
import rx.internal.util.atomic.SpscAtomicArrayQueue;
28+
import rx.internal.util.unsafe.*;
29+
import rx.plugins.RxJavaHooks;
30+
31+
/**
32+
* Split a sequence of strings based on a Rexexp pattern spanning subsequent
33+
* items if necessary.
34+
*/
35+
public final class ObservableSplit implements OnSubscribe<String> {
36+
37+
final Observable<String> source;
38+
39+
final Pattern pattern;
40+
41+
final int bufferSize;
42+
43+
public ObservableSplit(Observable<String> source, Pattern pattern, int bufferSize) {
44+
this.source = source;
45+
this.pattern = pattern;
46+
this.bufferSize = bufferSize;
47+
}
48+
49+
@Override
50+
public void call(Subscriber<? super String> t) {
51+
SplitSubscriber parent = new SplitSubscriber(t, pattern, bufferSize);
52+
t.add(parent.requested);
53+
t.setProducer(parent.requested);
54+
55+
source.unsafeSubscribe(parent);
56+
}
57+
58+
static final class SplitSubscriber extends Subscriber<String> {
59+
60+
final Subscriber<? super String> actual;
61+
62+
final Pattern pattern;
63+
64+
final Requested requested;
65+
66+
final AtomicInteger wip;
67+
68+
final int limit;
69+
70+
final Queue<String[]> queue;
71+
72+
String[] current;
73+
74+
String leftOver;
75+
76+
int index;
77+
78+
int produced;
79+
80+
int empty;
81+
82+
volatile boolean done;
83+
Throwable error;
84+
85+
volatile boolean cancelled;
86+
87+
SplitSubscriber(Subscriber<? super String> actual, Pattern pattern, int bufferSize) {
88+
this.actual = actual;
89+
this.pattern = pattern;
90+
this.limit = bufferSize - (bufferSize >> 2);
91+
this.requested = new Requested();
92+
this.wip = new AtomicInteger();
93+
if (UnsafeAccess.isUnsafeAvailable()) {
94+
this.queue = new SpscArrayQueue<String[]>(bufferSize);
95+
} else {
96+
this.queue = new SpscAtomicArrayQueue<String[]>(bufferSize);
97+
}
98+
request(bufferSize);
99+
}
100+
101+
@Override
102+
public void onNext(String t) {
103+
String lo = leftOver;
104+
String[] a;
105+
try {
106+
if (lo == null || lo.isEmpty()) {
107+
a = pattern.split(t, -1);
108+
} else {
109+
a = pattern.split(lo + t, -1);
110+
}
111+
} catch (Throwable ex) {
112+
Exceptions.throwIfFatal(ex);
113+
unsubscribe();
114+
onError(ex);
115+
return;
116+
}
117+
118+
if (a.length == 0) {
119+
leftOver = null;
120+
request(1);
121+
return;
122+
} else
123+
if (a.length == 1) {
124+
leftOver = a[0];
125+
request(1);
126+
return;
127+
}
128+
leftOver = a[a.length - 1];
129+
queue.offer(a);
130+
drain();
131+
}
132+
133+
@Override
134+
public void onError(Throwable e) {
135+
if (done) {
136+
RxJavaHooks.onError(e);
137+
return;
138+
}
139+
String lo = leftOver;
140+
if (lo != null && !lo.isEmpty()) {
141+
leftOver = null;
142+
queue.offer(new String[] { lo, null });
143+
}
144+
error = e;
145+
done = true;
146+
drain();
147+
}
148+
149+
@Override
150+
public void onCompleted() {
151+
if (!done) {
152+
done = true;
153+
String lo = leftOver;
154+
if (lo != null && !lo.isEmpty()) {
155+
leftOver = null;
156+
queue.offer(new String[] { lo, null });
157+
}
158+
drain();
159+
}
160+
}
161+
162+
void drain() {
163+
if (wip.getAndIncrement() != 0) {
164+
return;
165+
}
166+
167+
Queue<String[]> q = queue;
168+
169+
int missed = 1;
170+
int consumed = produced;
171+
String[] array = current;
172+
int idx = index;
173+
int emptyCount = empty;
174+
175+
Subscriber<? super String> a = actual;
176+
177+
for (;;) {
178+
long r = requested.get();
179+
long e = 0;
180+
181+
while (e != r) {
182+
if (cancelled) {
183+
current = null;
184+
q.clear();
185+
return;
186+
}
187+
188+
boolean d = done;
189+
190+
if (array == null) {
191+
array = q.poll();
192+
if (array != null) {
193+
current = array;
194+
if (++consumed == limit) {
195+
consumed = 0;
196+
request(limit);
197+
}
198+
}
199+
}
200+
201+
boolean empty = array == null;
202+
203+
if (d && empty) {
204+
current = null;
205+
Throwable ex = error;
206+
if (ex != null) {
207+
a.onError(ex);
208+
} else {
209+
a.onCompleted();
210+
}
211+
return;
212+
}
213+
214+
if (empty) {
215+
break;
216+
}
217+
218+
if (array.length == idx + 1) {
219+
array = null;
220+
current = null;
221+
idx = 0;
222+
continue;
223+
}
224+
225+
String v = array[idx];
226+
227+
if (v.isEmpty()) {
228+
emptyCount++;
229+
idx++;
230+
} else {
231+
while (emptyCount != 0 && e != r) {
232+
if (cancelled) {
233+
current = null;
234+
q.clear();
235+
return;
236+
}
237+
a.onNext("");
238+
e++;
239+
emptyCount--;
240+
}
241+
242+
if (e != r && emptyCount == 0) {
243+
a.onNext(v);
244+
245+
e++;
246+
idx++;
247+
}
248+
}
249+
}
250+
251+
if (e == r) {
252+
if (cancelled) {
253+
current = null;
254+
q.clear();
255+
return;
256+
}
257+
258+
boolean d = done;
259+
260+
if (array == null) {
261+
array = q.poll();
262+
if (array != null) {
263+
current = array;
264+
if (++consumed == limit) {
265+
consumed = 0;
266+
request(limit);
267+
}
268+
}
269+
}
270+
271+
boolean empty = array == null;
272+
273+
if (d && empty) {
274+
current = null;
275+
Throwable ex = error;
276+
if (ex != null) {
277+
a.onError(ex);
278+
} else {
279+
a.onCompleted();
280+
}
281+
return;
282+
}
283+
}
284+
285+
if (e != 0L) {
286+
BackpressureUtils.produced(requested, e);
287+
}
288+
289+
empty = emptyCount;
290+
produced = consumed;
291+
missed = wip.addAndGet(-missed);
292+
if (missed == 0) {
293+
break;
294+
}
295+
}
296+
}
297+
298+
void cancel() {
299+
cancelled = true;
300+
unsubscribe();
301+
if (wip.getAndIncrement() == 0) {
302+
current = null;
303+
queue.clear();
304+
}
305+
}
306+
307+
boolean isCancelled() {
308+
return isUnsubscribed();
309+
}
310+
311+
final class Requested extends AtomicLong implements Producer, Subscription {
312+
313+
private static final long serialVersionUID = 3399839515828647345L;
314+
315+
@Override
316+
public void request(long n) {
317+
if (n > 0) {
318+
BackpressureUtils.getAndAddRequest(this, n);
319+
drain();
320+
}
321+
else if (n < 0) {
322+
throw new IllegalArgumentException("n >= 0 required but it was " + n);
323+
}
324+
}
325+
326+
@Override
327+
public boolean isUnsubscribed() {
328+
return isCancelled();
329+
}
330+
331+
@Override
332+
public void unsubscribe() {
333+
cancel();
334+
}
335+
}
336+
}
337+
}

0 commit comments

Comments
 (0)