/*
* Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
*
* 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 reactor.core.publisher;
import java.util.
Objects;
import java.util.function.
BiPredicate;
import java.util.function.
Consumer;
import java.util.function.
Function;
import java.util.function.
Supplier;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Fuseable;
import reactor.core.
Fuseable.
ConditionalSubscriber;
import reactor.core.
Fuseable.
QueueSubscription;
import reactor.util.annotation.
Nullable;
import reactor.util.context.
Context;
/**
* For each subscriber, tracks the source values that have been seen and
* filters out duplicates.
*
* @param <T> the source value type
* @param <K> the key extracted from the source value to be used for duplicate testing
* @param <C> the backing store type used together with the keys when testing for duplicates with {@link BiPredicate}
*
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxDistinct<T, K, C> extends
FluxOperator<T, T> {
final
Function<? super T, ? extends K>
keyExtractor;
final
Supplier<C>
collectionSupplier;
final
BiPredicate<C, K>
distinctPredicate;
final
Consumer<C>
cleanupCallback;
FluxDistinct(
Flux<? extends T>
source,
Function<? super T, ? extends K>
keyExtractor,
Supplier<C>
collectionSupplier,
BiPredicate<C, K>
distinctPredicate,
Consumer<C>
cleanupCallback) {
super(
source);
this.
keyExtractor =
Objects.
requireNonNull(
keyExtractor, "keyExtractor");
this.
collectionSupplier =
Objects.
requireNonNull(
collectionSupplier, "collectionSupplier");
this.
distinctPredicate =
Objects.
requireNonNull(
distinctPredicate, "distinctPredicate");
this.
cleanupCallback =
Objects.
requireNonNull(
cleanupCallback, "cleanupCallback");
}
@
Override
@
SuppressWarnings("unchecked")
public void
subscribe(
CoreSubscriber<? super T>
actual) {
C
collection;
try {
collection =
Objects.
requireNonNull(
collectionSupplier.
get(),
"The collectionSupplier returned a null collection");
}
catch (
Throwable e) {
Operators.
error(
actual,
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
if (
actual instanceof
ConditionalSubscriber) {
source.
subscribe(new
DistinctConditionalSubscriber<>((
ConditionalSubscriber<? super T>)
actual,
collection,
keyExtractor,
distinctPredicate,
cleanupCallback));
}
else {
source.
subscribe(new
DistinctSubscriber<>(
actual,
collection,
keyExtractor,
distinctPredicate,
cleanupCallback));
}
}
static final class
DistinctSubscriber<T, K, C>
implements
ConditionalSubscriber<T>,
InnerOperator<T, T> {
final
CoreSubscriber<? super T>
actual;
final
Context ctx;
final C
collection;
final
Function<? super T, ? extends K>
keyExtractor;
final
BiPredicate<C, K>
distinctPredicate;
final
Consumer<C>
cleanupCallback;
Subscription s;
boolean
done;
DistinctSubscriber(
CoreSubscriber<? super T>
actual,
C
collection,
Function<? super T, ? extends K>
keyExtractor,
BiPredicate<C, K>
distinctPredicate,
Consumer<C>
cleanupCallback) {
this.
actual =
actual;
this.
ctx =
actual.
currentContext();
this.
collection =
collection;
this.
keyExtractor =
keyExtractor;
this.
distinctPredicate =
distinctPredicate;
this.
cleanupCallback =
cleanupCallback;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (!
tryOnNext(
t)) {
s.
request(1);
}
}
@
Override
public boolean
tryOnNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t, this.
ctx);
return true;
}
K
k;
try {
k =
Objects.
requireNonNull(
keyExtractor.
apply(
t),
"The distinct extractor returned a null value.");
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
boolean
b;
try {
b =
distinctPredicate.
test(
collection,
k);
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t,
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
if (
b) {
actual.
onNext(
t);
return true;
}
Operators.
onDiscard(
t ,
ctx);
return false;
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t, this.
ctx);
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onComplete();
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
s.
request(
n);
}
@
Override
public void
cancel() {
s.
cancel();
if (
collection != null) {
cleanupCallback.
accept(
collection);
}
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
TERMINATED) return
done;
return
InnerOperator.super.scanUnsafe(
key);
}
}
static final class
DistinctConditionalSubscriber<T, K, C>
implements
ConditionalSubscriber<T>,
InnerOperator<T, T> {
final
ConditionalSubscriber<? super T>
actual;
final
Context ctx;
final C
collection;
final
Function<? super T, ? extends K>
keyExtractor;
final
BiPredicate<C, K>
distinctPredicate;
final
Consumer<C>
cleanupCallback;
Subscription s;
boolean
done;
DistinctConditionalSubscriber(
ConditionalSubscriber<? super T>
actual,
C
collection,
Function<? super T, ? extends K>
keyExtractor,
BiPredicate<C, K>
distinctPredicate,
Consumer<C>
cleanupCallback) {
this.
actual =
actual;
this.
ctx =
actual.
currentContext();
this.
collection =
collection;
this.
keyExtractor =
keyExtractor;
this.
distinctPredicate =
distinctPredicate;
this.
cleanupCallback =
cleanupCallback;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t, this.
ctx);
return;
}
K
k;
try {
k =
Objects.
requireNonNull(
keyExtractor.
apply(
t),
"The distinct extractor returned a null value.");
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return;
}
boolean
b;
try {
b =
distinctPredicate.
test(
collection,
k);
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return;
}
if (
b) {
actual.
onNext(
t);
}
else {
Operators.
onDiscard(
t,
ctx);
s.
request(1);
}
}
@
Override
public boolean
tryOnNext(T
t) {
if (
done) {
Operators.
onNextDropped(
t, this.
ctx);
return true;
}
K
k;
try {
k =
Objects.
requireNonNull(
keyExtractor.
apply(
t),
"The distinct extractor returned a null value.");
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
boolean
b;
try {
b =
distinctPredicate.
test(
collection,
k);
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
s,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
if (
b) {
return
actual.
tryOnNext(
t);
}
else {
Operators.
onDiscard(
t,
ctx);
return false;
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t, this.
ctx);
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onComplete();
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
s.
request(
n);
}
@
Override
public void
cancel() {
s.
cancel();
if (
collection != null) {
cleanupCallback.
accept(
collection);
}
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
TERMINATED) return
done;
return
InnerOperator.super.scanUnsafe(
key);
}
}
static final class
DistinctFuseableSubscriber<T, K, C>
implements
ConditionalSubscriber<T>,
InnerOperator<T, T>,
QueueSubscription<T> {
final
CoreSubscriber<? super T>
actual;
final
Context ctx;
final C
collection;
final
Function<? super T, ? extends K>
keyExtractor;
final
BiPredicate<C, K>
distinctPredicate;
final
Consumer<C>
cleanupCallback;
QueueSubscription<T>
qs;
boolean
done;
int
sourceMode;
DistinctFuseableSubscriber(
CoreSubscriber<? super T>
actual, C
collection,
Function<? super T, ? extends K>
keyExtractor,
BiPredicate<C, K>
predicate,
Consumer<C>
callback) {
this.
actual =
actual;
this.
ctx =
actual.
currentContext();
this.
collection =
collection;
this.
keyExtractor =
keyExtractor;
this.
distinctPredicate =
predicate;
this.
cleanupCallback =
callback;
}
@
SuppressWarnings("unchecked")
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
qs,
s)) {
this.
qs = (
QueueSubscription<T>)
s;
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
if (!
tryOnNext(
t)) {
qs.
request(1);
}
}
@
Override
public boolean
tryOnNext(T
t) {
if (
sourceMode ==
Fuseable.
ASYNC) {
actual.
onNext(null);
return true;
}
if (
done) {
Operators.
onNextDropped(
t, this.
ctx);
return true;
}
K
k;
try {
k =
Objects.
requireNonNull(
keyExtractor.
apply(
t),
"The distinct extractor returned a null value.");
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
qs,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
boolean
b;
try {
b =
distinctPredicate.
test(
collection,
k);
}
catch (
Throwable e) {
onError(
Operators.
onOperatorError(
qs,
e,
t, this.
ctx));
Operators.
onDiscard(
t, this.
ctx);
return true;
}
if (
b) {
actual.
onNext(
t);
return true;
}
Operators.
onDiscard(
t,
ctx);
return false;
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
Operators.
onErrorDropped(
t, this.
ctx);
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onError(
t);
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
cleanupCallback.
accept(
collection);
actual.
onComplete();
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
@
Override
public void
request(long
n) {
qs.
request(
n);
}
@
Override
public void
cancel() {
qs.
cancel();
if (
collection != null) {
cleanupCallback.
accept(
collection);
}
}
@
Override
public int
requestFusion(int
requestedMode) {
int
m =
qs.
requestFusion(
requestedMode);
sourceMode =
m;
return
m;
}
@
Override
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
qs;
if (
key ==
Attr.
TERMINATED) return
done;
return
InnerOperator.super.scanUnsafe(
key);
}
@
Override
@
Nullable
public T
poll() {
if (
sourceMode ==
Fuseable.
ASYNC) {
long
dropped = 0;
for (; ; ) {
T
v =
qs.
poll();
if (
v == null) {
return null;
}
try {
K
r =
Objects.
requireNonNull(
keyExtractor.
apply(
v),
"The keyExtractor returned a null collection");
if (
distinctPredicate.
test(
collection,
r)) {
if (
dropped != 0) {
request(
dropped);
}
return
v;
}
Operators.
onDiscard(
v,
ctx);
dropped++;
}
catch (
Throwable error) {
Operators.
onDiscard(
v, this.
ctx);
throw
error;
}
}
}
else {
for (; ; ) {
T
v =
qs.
poll();
if (
v == null) {
return null;
}
try {
K
r =
Objects.
requireNonNull(
keyExtractor.
apply(
v),
"The keyExtractor returned a null collection");
if (
distinctPredicate.
test(
collection,
r)) {
return
v;
}
else {
Operators.
onDiscard(
v,
ctx);
}
}
catch (
Throwable error) {
Operators.
onDiscard(
v, this.
ctx);
throw
error;
}
}
}
}
@
Override
public boolean
isEmpty() {
return
qs.
isEmpty();
}
@
Override
public void
clear() {
qs.
clear();
cleanupCallback.
accept(
collection);
}
@
Override
public int
size() {
return
qs.
size();
}
}
}