Package org.apache.bookkeeper.common.concurrent

Class FutureUtils

java.lang.Object

org.apache.bookkeeper.common.concurrent.FutureUtils

public final class FutureUtils
extends Object

Future related utils.

Method Summary

Modifier and Type	Method	Description
static <T> CompletableFuture<List<T>>	collect(List<CompletableFuture<T>> futureList)
static <T> void	complete(CompletableFuture<T> result, T value)
static <T> void	completeExceptionally(CompletableFuture<T> result, Throwable cause)
static <T> CompletableFuture<T>	createFuture()
static <T> CompletableFuture<T>	ensure(CompletableFuture<T> future, Runnable ensureBlock)
static <T> CompletableFuture<T>	exception(Throwable cause)
static <T> CompletableFuture<Void>	ignore(CompletableFuture<T> future)	Ignore exception from the future.
static <T> CompletableFuture<Void>	ignore(CompletableFuture<T> future, String errorMsg)	Ignore exception from the future and log errorMsg on exceptions.
static <T, R> CompletableFuture<List<R>>	processList(List<T> collection, Function<T,CompletableFuture<R>> processFunc, ExecutorService callbackExecutor)	Process the list of items one by one using the process function processFunc.
static <T> void	proxyTo(CompletableFuture<T> src, CompletableFuture<T> target)
static <T> CompletableFuture<T>	rescue(CompletableFuture<T> future, Function<Throwable,CompletableFuture<T>> rescueFuc)
static <T> T	result(CompletableFuture<T> future)
static <T> T	result(CompletableFuture<T> future, long timeout, TimeUnit timeUnit)
static <T, ExceptionT extends Throwable> T	result(CompletableFuture<T> future, Function<Throwable,ExceptionT> exceptionHandler)
static <T, ExceptionT extends Throwable> T	result(CompletableFuture<T> future, Function<Throwable,ExceptionT> exceptionHandler, long timeout, TimeUnit timeUnit)
static <T> CompletableFuture<T>	stats(CompletableFuture<T> result, OpStatsLogger opStatsLogger, com.google.common.base.Stopwatch stopwatch)	Add a event listener over result for collecting the operation stats.
static <T> CompletableFuture<T>	value(T value)
static CompletableFuture<Void>	Void()
static <T> CompletableFuture<T>	whenCompleteAsync(CompletableFuture<T> future, BiConsumer<? super T,? super Throwable> action, OrderedScheduler scheduler, Object scheduleKey)	Completing the future in the thread in the scheduler identified by the scheduleKey.
static <T> CompletableFuture<T>	within(CompletableFuture<T> promise, long timeout, TimeUnit unit, Throwable cause, OrderedScheduler scheduler, Object key)	Raise an exception to the promise within a given timeout period.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

Void

public static CompletableFuture<Void> Void()

result

public static <T> T result(CompletableFuture<T> future)
                    throws Exception

Throws:

Exception

result

public static <T> T result(CompletableFuture<T> future,
 long timeout,
 TimeUnit timeUnit)
                    throws Exception

Throws:

Exception

result

public static <T,
ExceptionT extends Throwable> T result(CompletableFuture<T> future,
 Function<Throwable,ExceptionT> exceptionHandler)
                                                 throws ExceptionT

Throws:

ExceptionT extends Throwable

result

public static <T,
ExceptionT extends Throwable> T result(CompletableFuture<T> future,
 Function<Throwable,ExceptionT> exceptionHandler,
 long timeout,
 TimeUnit timeUnit)
                                                 throws ExceptionT,
TimeoutException

Throws:

ExceptionT extends Throwable

TimeoutException

createFuture

public static <T> CompletableFuture<T> createFuture()

value

public static <T> CompletableFuture<T> value(T value)

exception

public static <T> CompletableFuture<T> exception(Throwable cause)

complete

public static <T> void complete(CompletableFuture<T> result,
 T value)

completeExceptionally

public static <T> void completeExceptionally(CompletableFuture<T> result,
 Throwable cause)

whenCompleteAsync

public static <T> CompletableFuture<T> whenCompleteAsync(CompletableFuture<T> future,
 BiConsumer<? super T,? super Throwable> action,
 OrderedScheduler scheduler,
 Object scheduleKey)

Completing the future in the thread in the scheduler identified by the scheduleKey.

Type Parameters:

T -

Parameters:

future - future to complete

action - action to execute when complete

scheduler - scheduler to execute the action.

scheduleKey - key to choose the thread to execute the action

Returns:

collect

public static <T> CompletableFuture<List<T>> collect(List<CompletableFuture<T>> futureList)

proxyTo

public static <T> void proxyTo(CompletableFuture<T> src,
 CompletableFuture<T> target)

processList

public static <T,
R> CompletableFuture<List<R>> processList(List<T> collection,
 Function<T,CompletableFuture<R>> processFunc,
 @Nullable
 ExecutorService callbackExecutor)

Process the list of items one by one using the process function processFunc. The process will be stopped immediately if it fails on processing any one.

Parameters:

collection - list of items

processFunc - process function

callbackExecutor - executor to process the item

Returns:

future presents the list of processed results

within

public static <T> CompletableFuture<T> within(CompletableFuture<T> promise,
 long timeout,
 TimeUnit unit,
 Throwable cause,
 OrderedScheduler scheduler,
 Object key)

Raise an exception to the promise within a given timeout period. If the promise has been satisfied before raising, it won't change the state of the promise.

Parameters:

promise - promise to raise exception

timeout - timeout period

unit - timeout period unit

cause - cause to raise

scheduler - scheduler to execute raising exception

key - the submit key used by the scheduler

Returns:

the promise applied with the raise logic

ignore

public static <T> CompletableFuture<Void> ignore(CompletableFuture<T> future)

Ignore exception from the future.

Parameters:

future - the original future

Returns:

a transformed future ignores exceptions

ignore

public static <T> CompletableFuture<Void> ignore(CompletableFuture<T> future,
 String errorMsg)

Ignore exception from the future and log errorMsg on exceptions.

Parameters:

future - the original future

errorMsg - the error message to log on exceptions

Returns:

a transformed future ignores exceptions

ensure

public static <T> CompletableFuture<T> ensure(CompletableFuture<T> future,
 Runnable ensureBlock)

rescue

public static <T> CompletableFuture<T> rescue(CompletableFuture<T> future,
 Function<Throwable,CompletableFuture<T>> rescueFuc)

stats

public static <T> CompletableFuture<T> stats(CompletableFuture<T> result,
 OpStatsLogger opStatsLogger,
 com.google.common.base.Stopwatch stopwatch)

Add a event listener over result for collecting the operation stats.

Type Parameters:

T -

Parameters:

result - result to listen on

opStatsLogger - stats logger to record operations stats

stopwatch - stop watch to time operation

Returns:

result after registered the event listener