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package org.glassfish.grizzly.utils;
import java.util.concurrent.Future;
import org.glassfish.grizzly.CompletionHandler;
import org.glassfish.grizzly.Copyable;
import org.glassfish.grizzly.EmptyCompletionHandler;
import org.glassfish.grizzly.GrizzlyFuture;
import org.glassfish.grizzly.impl.FutureImpl;
import org.glassfish.grizzly.impl.ReadyFutureImpl;
import org.glassfish.grizzly.impl.SafeFutureImpl;
import org.glassfish.grizzly.impl.UnsafeFutureImpl;
/**
* Set of {@link Future} utilities.
*
* @author Alexey Stashok
*/
public class Futures {
/**
* Returns thread-safe {@link FutureImpl} implementation. (Based on the JDK {@link java.util.concurrent.FutureTask}).
*
* @return thread-safe {@link FutureImpl} implementation.
*/
public static FutureImpl createSafeFuture() {
return SafeFutureImpl.create();
}
/**
* Returns non thread-safe {@link FutureImpl} implementation.
*
* @return non thread-safe {@link FutureImpl} implementation.
*/
public static FutureImpl createUnsafeFuture() {
return UnsafeFutureImpl.create();
}
/**
* Create a {@link Future}, which has a preset result.
*
* @param result the result
* @return a {@link Future}, which has a preset result.
*/
public static GrizzlyFuture createReadyFuture(final R result) {
return ReadyFutureImpl.create(result);
}
/**
* Create a {@link Future}, which has a preset failure.
*
* @param error the failure
* @return a {@link Future}, which has a preset failure.
*/
public static GrizzlyFuture createReadyFuture(final Throwable error) {
return ReadyFutureImpl.create(error);
}
/**
* Complete passed {@link FutureImpl} and {@link CompletionHandler} using
* the passed result object.
*
* @param future {@link FutureImpl} to be notified
* @param completionHandler {@link CompletionHandler} to be notified
* @param result the result
*/
public static void notifyResult(final FutureImpl future,
final CompletionHandler completionHandler, final R result) {
if (completionHandler != null) {
completionHandler.completed(result);
}
if (future != null) {
future.result(result);
}
}
/**
* Complete passed {@link FutureImpl} and {@link CompletionHandler} using
* the passed error
*
* @param future {@link FutureImpl} to be notified
* @param completionHandler {@link CompletionHandler} to be notified
* @param error the error.
*/
public static void notifyFailure(final FutureImpl future,
final CompletionHandler completionHandler, final Throwable error) {
if (completionHandler != null) {
completionHandler.failed(error);
}
if (future != null) {
future.failure(error);
}
}
/**
* Complete passed {@link FutureImpl} and {@link CompletionHandler} via
* the cancellation notification.
*
* @param future {@link FutureImpl} to be notified
* @param completionHandler {@link CompletionHandler} to be notified
*/
public static void notifyCancel(final FutureImpl future,
final CompletionHandler completionHandler) {
if (completionHandler != null) {
completionHandler.cancelled();
}
if (future != null) {
future.cancel(false);
}
}
/**
* Creates {@link CompletionHandler}, which may serve as a bridge for passed
* {@link FutureImpl}. All the notifications coming to the returned
* {@link CompletionHandler} will be passed to the passed {@link FutureImpl}.
*
* @return {@link CompletionHandler}, which may serve as a bridge for passed
* {@link FutureImpl}. All the notifications coming to the returned
* {@link CompletionHandler} will be passed to the passed {@link FutureImpl}.
*/
public static CompletionHandler toCompletionHandler(
final FutureImpl future) {
return new FutureToCompletionHandler(future);
}
/**
* Creates {@link CompletionHandler}, which may serve as a bridge for passed
* {@link FutureImpl} and {@link CompletionHandler} objects.
* All the notifications coming to the returned {@link CompletionHandler}
* will be passed to the {@link FutureImpl} and {@link CompletionHandler}
* passed as parameters.
*
* @return {@link CompletionHandler}, which may serve as a bridge for passed
* {@link FutureImpl} and {@link CompletionHandler} objects.
* All the notifications coming to the returned {@link CompletionHandler}
* will be passed to the {@link FutureImpl} and {@link CompletionHandler}
* passed as parameters.
*/
public static CompletionHandler toCompletionHandler(
final FutureImpl future,
final CompletionHandler completionHandler) {
return new CompletionHandlerAdapter(future, completionHandler);
}
/**
* Creates {@link CompletionHandler}, which may serve as a bridge
* for passed {@link FutureImpl}. All the notifications coming to the returned
* {@link CompletionHandler} will be adapted using
* {@link GenericAdapter} and passed to the {@link FutureImpl}.
*
* @return {@link CompletionHandler}, which may serve as a bridge
* for passed {@link FutureImpl}. All the notifications coming to the returned
* {@link CompletionHandler} will be adapted using
* {@link GenericAdapter} and passed to the {@link FutureImpl}.
*/
public static CompletionHandler toAdaptedCompletionHandler(
final FutureImpl future,
final GenericAdapter adapter) {
return toAdaptedCompletionHandler(future, null, adapter);
}
/**
* Creates {@link CompletionHandler}, which may serve as a bridge
* for passed {@link FutureImpl} and {@link CompletionHandler}.
* All the notifications coming to the returned {@link CompletionHandler}
* will be adapted using {@link GenericAdapter} and passed to the
* {@link FutureImpl} and {@link CompletionHandler}.
*
* @return {@link CompletionHandler}, which may serve as a bridge
* for passed {@link FutureImpl} and {@link CompletionHandler}.
* All the notifications coming to the returned {@link CompletionHandler}
* will be adapted using {@link GenericAdapter} and passed to the
* {@link FutureImpl} and {@link CompletionHandler}.
*/
public static CompletionHandler toAdaptedCompletionHandler(
final FutureImpl future,
final CompletionHandler completionHandler,
final GenericAdapter adapter) {
return new CompletionHandlerAdapter(
future, completionHandler, adapter);
}
private static final class FutureToCompletionHandler
extends EmptyCompletionHandler {
private final FutureImpl future;
public FutureToCompletionHandler(FutureImpl future) {
this.future = future;
}
@Override
public void cancelled() {
future.cancel(false);
}
@Override
@SuppressWarnings("unchecked")
public void completed(E result) {
if (result instanceof Copyable) {
result = (E) ((Copyable) result).copy();
}
future.result(result);
}
@Override
public void failed(final Throwable throwable) {
future.failure(throwable);
}
}
}