rx.operators.OperationAverage Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rxjava-core Show documentation
Show all versions of rxjava-core Show documentation
rxjava-core developed by Netflix
/**
* Copyright 2014 Netflix, Inc.
*
* 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 rx.operators;
import rx.Observable;
import rx.Observable.OnSubscribeFunc;
import rx.Observer;
import rx.Subscription;
import rx.functions.Func1;
import rx.functions.Func2;
/**
* A few operators for implementing the averaging operation.
*
* @see MSDN: Observable.Average
*/
public final class OperationAverage {
private static final class Tuple2 {
private final T current;
private final Integer count;
private Tuple2(T v1, Integer v2) {
current = v1;
count = v2;
}
}
public static Observable average(Observable source) {
return source.reduce(new Tuple2(0, 0), new Func2, Integer, Tuple2>() {
@Override
public Tuple2 call(Tuple2 accu, Integer next) {
return new Tuple2(accu.current + next, accu.count + 1);
}
}).map(new Func1, Integer>() {
@Override
public Integer call(Tuple2 result) {
if (result.count == 0) {
throw new IllegalArgumentException("Sequence contains no elements");
}
return result.current / result.count;
}
});
}
public static Observable averageLongs(Observable source) {
return source.reduce(new Tuple2(0L, 0), new Func2, Long, Tuple2>() {
@Override
public Tuple2 call(Tuple2 accu, Long next) {
return new Tuple2(accu.current + next, accu.count + 1);
}
}).map(new Func1, Long>() {
@Override
public Long call(Tuple2 result) {
if (result.count == 0) {
throw new IllegalArgumentException("Sequence contains no elements");
}
return result.current / result.count;
}
});
}
public static Observable averageFloats(Observable source) {
return source.reduce(new Tuple2(0.0f, 0), new Func2, Float, Tuple2>() {
@Override
public Tuple2 call(Tuple2 accu, Float next) {
return new Tuple2(accu.current + next, accu.count + 1);
}
}).map(new Func1, Float>() {
@Override
public Float call(Tuple2 result) {
if (result.count == 0) {
throw new IllegalArgumentException("Sequence contains no elements");
}
return result.current / result.count;
}
});
}
public static Observable averageDoubles(Observable source) {
return source.reduce(new Tuple2(0.0d, 0), new Func2, Double, Tuple2>() {
@Override
public Tuple2 call(Tuple2 accu, Double next) {
return new Tuple2(accu.current + next, accu.count + 1);
}
}).map(new Func1, Double>() {
@Override
public Double call(Tuple2 result) {
if (result.count == 0) {
throw new IllegalArgumentException("Sequence contains no elements");
}
return result.current / result.count;
}
});
}
/**
* Compute the average by extracting integer values from the source via an
* extractor function.
*
* @param
* the source value type
*/
public static final class AverageIntegerExtractor implements OnSubscribeFunc {
final Observable source;
final Func1 valueExtractor;
public AverageIntegerExtractor(Observable source, Func1 valueExtractor) {
this.source = source;
this.valueExtractor = valueExtractor;
}
@Override
public Subscription onSubscribe(Observer t1) {
return source.subscribe(new AverageObserver(t1));
}
/** Computes the average. */
private final class AverageObserver implements Observer {
final Observer observer;
int sum;
int count;
public AverageObserver(Observer observer) {
this.observer = observer;
}
@Override
public void onNext(T args) {
sum += valueExtractor.call(args);
count++;
}
@Override
public void onError(Throwable e) {
observer.onError(e);
}
@Override
public void onCompleted() {
if (count > 0) {
try {
observer.onNext(sum / count);
} catch (Throwable t) {
observer.onError(t);
return;
}
observer.onCompleted();
} else {
observer.onError(new IllegalArgumentException("Sequence contains no elements"));
}
}
}
}
/**
* Compute the average by extracting long values from the source via an
* extractor function.
*
* @param
* the source value type
*/
public static final class AverageLongExtractor implements OnSubscribeFunc {
final Observable source;
final Func1 valueExtractor;
public AverageLongExtractor(Observable source, Func1 valueExtractor) {
this.source = source;
this.valueExtractor = valueExtractor;
}
@Override
public Subscription onSubscribe(Observer t1) {
return source.subscribe(new AverageObserver(t1));
}
/** Computes the average. */
private final class AverageObserver implements Observer {
final Observer observer;
long sum;
int count;
public AverageObserver(Observer observer) {
this.observer = observer;
}
@Override
public void onNext(T args) {
sum += valueExtractor.call(args);
count++;
}
@Override
public void onError(Throwable e) {
observer.onError(e);
}
@Override
public void onCompleted() {
if (count > 0) {
try {
observer.onNext(sum / count);
} catch (Throwable t) {
observer.onError(t);
return;
}
observer.onCompleted();
} else {
observer.onError(new IllegalArgumentException("Sequence contains no elements"));
}
}
}
}
/**
* Compute the average by extracting float values from the source via an
* extractor function.
*
* @param
* the source value type
*/
public static final class AverageFloatExtractor implements OnSubscribeFunc {
final Observable source;
final Func1 valueExtractor;
public AverageFloatExtractor(Observable source, Func1 valueExtractor) {
this.source = source;
this.valueExtractor = valueExtractor;
}
@Override
public Subscription onSubscribe(Observer t1) {
return source.subscribe(new AverageObserver(t1));
}
/** Computes the average. */
private final class AverageObserver implements Observer {
final Observer observer;
float sum;
int count;
public AverageObserver(Observer observer) {
this.observer = observer;
}
@Override
public void onNext(T args) {
sum += valueExtractor.call(args);
count++;
}
@Override
public void onError(Throwable e) {
observer.onError(e);
}
@Override
public void onCompleted() {
if (count > 0) {
try {
observer.onNext(sum / count);
} catch (Throwable t) {
observer.onError(t);
return;
}
observer.onCompleted();
} else {
observer.onError(new IllegalArgumentException("Sequence contains no elements"));
}
}
}
}
/**
* Compute the average by extracting double values from the source via an
* extractor function.
*
* @param
* the source value type
*/
public static final class AverageDoubleExtractor implements OnSubscribeFunc {
final Observable source;
final Func1 valueExtractor;
public AverageDoubleExtractor(Observable source, Func1 valueExtractor) {
this.source = source;
this.valueExtractor = valueExtractor;
}
@Override
public Subscription onSubscribe(Observer t1) {
return source.subscribe(new AverageObserver(t1));
}
/** Computes the average. */
private final class AverageObserver implements Observer {
final Observer observer;
double sum;
int count;
public AverageObserver(Observer observer) {
this.observer = observer;
}
@Override
public void onNext(T args) {
sum += valueExtractor.call(args);
count++;
}
@Override
public void onError(Throwable e) {
observer.onError(e);
}
@Override
public void onCompleted() {
if (count > 0) {
try {
observer.onNext(sum / count);
} catch (Throwable t) {
observer.onError(t);
return;
}
observer.onCompleted();
} else {
observer.onError(new IllegalArgumentException("Sequence contains no elements"));
}
}
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy