AsyncUtil (FoundationDB Java Client API)

java.lang.Object
- com.foundationdb.async.AsyncUtil

```
public class AsyncUtil
extends Object
```
Provided utilities for using and manipulating Futures. Many of the methods in this class have two versions -- one for dealing with PartialFutures and one for Futures.

Method Summary

Methods
Modifier and Type	Method and Description
`static <I,O> Future<O>`	`applySafely(Function<I,Future<O>> func, I value)` Run `Function` `func`, returning all caught exceptions as a `Future` in an error state.
`static <I,O> PartialFuture<O>`	`applySafely(PartialFunction<I,? extends PartialFuture<O>> func, I value)` Run `PartialFunction` `func`, returning all caught exceptions as a `PartialFuture` in an error state.
`static <V> Future<List<V>>`	`collect(AsyncIterable<V> iterable)` Iterates over a set of items and returns the result as a list.
`static <V> Future<List<V>>`	`getAll(Collection<Future<V>> tasks)` Collects the results of many asynchronous processes into one asynchronous output.
`static <V> PartialFuture<List<V>>`	`getAllPartial(Collection<PartialFuture<V>> tasks)` Collects the results of many asynchronous processes into one asynchronous output.
`static <V,T> AsyncIterable<T>`	`mapIterable(AsyncIterable<V> iterable, Function<V,T> func)` Map an `AsyncIterable` into an `AsyncIterable` of another type or with each element modified in some fashion.
`static <V> Future<Void>`	`success(Future<V> task)` Maps the outcome of a task into a completion signal.
`static <V> PartialFuture<Void>`	`success(PartialFuture<V> task)` Maps the outcome of a task into a completion signal.
`static <V,T> Future<V>`	`tag(Future<T> task, V value)` Replaces the output of an asynchronous task with a predetermined value.
`static <V,T> PartialFuture<V>`	`tag(PartialFuture<T> task, V value)` Replaces the output of an asynchronous task with a predetermined value.
`static <V> Future<Void>`	`whenAll(Collection<? extends PartialFuture<V>> input)` Return a `Future` that will be set when all the `PartialFuture` inputs are done.
`static <V> Future<Void>`	`whenAny(Collection<? extends PartialFuture<V>> input)` Return a `Future` that will be set when any of the `PartialFuture` inputs are done.
`static <V> Future<Void>`	`whenReady(PartialFuture<V> task)` Maps the readiness of a `PartialFuture` into a completion signal.
`static Future<Void>`	`whileTrue(Function<Void,Future<Boolean>> body)` Executes an asynchronous operation repeatedly until it returns `False`.
`static PartialFuture<Void>`	`whileTrue(PartialFunction<Void,? extends PartialFuture<Boolean>> body)` Executes an asynchronous operation repeatedly until it returns `False`.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - applySafely
```
public static <I,O> Future<O> applySafely(Function<I,Future<O>> func,
                          I value)
```
    Run Function func, returning all caught exceptions as a Future in an error state.
    
    Parameters:
    func - the Function to run
    value - the input to pass to func
    
    Returns:
    the output of func, or a Future carrying any exception caught in the process.
  - applySafely
```
public static <I,O> PartialFuture<O> applySafely(PartialFunction<I,? extends PartialFuture<O>> func,
                                 I value)
```
    Run PartialFunction func, returning all caught exceptions as a PartialFuture in an error state.
    
    Parameters:
    func - the PartialFunction to run
    value - the input to pass to func
    
    Returns:
    the output of func, or a PartialFuture carrying any exception caught in the process.
  - collect
```
public static <V> Future<List<V>> collect(AsyncIterable<V> iterable)
```
    Iterates over a set of items and returns the result as a list.
    
    Parameters:
    iterable - the source of data over which to iterate
    
    Returns:
    a Future which will be set to the amalgamation of results from iteration.
  - mapIterable
```
public static <V,T> AsyncIterable<T> mapIterable(AsyncIterable<V> iterable,
                                 Function<V,T> func)
```
    Map an AsyncIterable into an AsyncIterable of another type or with each element modified in some fashion.
    
    Parameters:
    iterable - input
    func - mapping function applied to each element
    
    Returns:
    a new iterable with each element mapped to a different value
  - whileTrue
```
public static PartialFuture<Void> whileTrue(PartialFunction<Void,? extends PartialFuture<Boolean>> body)
```
    Executes an asynchronous operation repeatedly until it returns False.
    
    Parameters:
    body - the asynchronous operation over which to loop
    
    Returns:
    a PartialFuture which will be set at completion of the loop.
  - whileTrue
```
public static Future<Void> whileTrue(Function<Void,Future<Boolean>> body)
```
    Executes an asynchronous operation repeatedly until it returns False.
    
    Parameters:
    body - the asynchronous operation over which to loop
    
    Returns:
    a Future which will be set at completion of the loop.
  - success
```
public static <V> Future<Void> success(Future<V> task)
```
    Maps the outcome of a task into a completion signal. Can be useful if task has side-effects for which all is needed is a signal of completion. All errors from task will be passed to the resulting Future.
    
    Parameters:
    task - the asynchronous process for which to signal completion
    
    Returns:
    a newly created Future that is set when task completes
  - success
```
public static <V> PartialFuture<Void> success(PartialFuture<V> task)
```
    Maps the outcome of a task into a completion signal. Can be useful if task has side-effects for which all is needed is a signal of completion. All errors from task will be passed to the resulting PartialFuture.
    
    Parameters:
    task - the asynchronous process for which to signal completion
    
    Returns:
    a newly created Future that is set when task completes
  - whenReady
```
public static <V> Future<Void> whenReady(PartialFuture<V> task)
```
    Maps the readiness of a PartialFuture into a completion signal. When the given PartialFuture is set to a value or an error, the returned Future will be set to null. The returned Future will never be set to an error unless it is explicitly cancelled.
    
    Parameters:
    task - the asynchronous process to monitor the readiness of
    
    Returns:
    a new Future that is set when task is ready.
  - getAll
```
public static <V> Future<List<V>> getAll(Collection<Future<V>> tasks)
```
    Collects the results of many asynchronous processes into one asynchronous output. If any of the tasks returns an error, the output is set to that error.
    
    Parameters:
    tasks - the tasks whose output is to be added to the output
    
    Returns:
    a Future that will be set to the collective result of the tasks
  - getAllPartial
```
public static <V> PartialFuture<List<V>> getAllPartial(Collection<PartialFuture<V>> tasks)
```
    Collects the results of many asynchronous processes into one asynchronous output. If any of the tasks returns an error, the output is set to that error.
    
    Parameters:
    tasks - the tasks whose output is to be added to the output
    
    Returns:
    a Future that will be set to the collective result of the tasks
  - tag
```
public static <V,T> Future<V> tag(Future<T> task,
                  V value)
```
    Replaces the output of an asynchronous task with a predetermined value.
    
    Parameters:
    task - the asynchronous process whose output is to be replaced
    value - the predetermined value to be returned on success of task
    
    Returns:
    a Future that will be set to value on completion of task
  - tag
```
public static <V,T> PartialFuture<V> tag(PartialFuture<T> task,
                         V value)
```
    Replaces the output of an asynchronous task with a predetermined value.
    
    Parameters:
    task - the asynchronous process whose output is to be replaced
    value - the predetermined value to be returned on success of task
    
    Returns:
    a Future that will be set to value on completion of task
  - whenAny
```
public static <V> Future<Void> whenAny(Collection<? extends PartialFuture<V>> input)
```
    Return a Future that will be set when any of the PartialFuture inputs are done. A Future is done both on success and failure.
    
    Parameters:
    input - the list of PartialFutures to monitor. This list must not be modified during the execution of this call.
    
    Returns:
    a signal that will be set when any of the Futures are done
  - whenAll
```
public static <V> Future<Void> whenAll(Collection<? extends PartialFuture<V>> input)
```
    Return a Future that will be set when all the PartialFuture inputs are done. A Future is done both on success and failure.
    
    Parameters:
    input - the list of PartialFutures to monitor. This list must not be modified during the execution of this call.
    
    Returns:
    a signal that will be set when all of the Futures are done

Class AsyncUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

applySafely

applySafely

collect

mapIterable

whileTrue

whileTrue

success

success

whenReady

getAll

getAllPartial

tag

tag

whenAny

whenAll