com.facebook.presto.hive.util

Class AsyncQueue<T>

java.lang.Object

com.facebook.presto.hive.util.AsyncQueue<T>

@ThreadSafe
public class AsyncQueue<T>
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AsyncQueue.BorrowResult<T,R>

Constructor Summary

Constructors

Constructor and Description
AsyncQueue(int targetQueueSize, Executor executor)

Method Summary

Modifier and Type	Method and Description
<O> com.google.common.util.concurrent.ListenableFuture<O>	borrowBatchAsync(int maxSize, Function<List<T>,AsyncQueue.BorrowResult<T,O>> function) Invoke function with up to maxSize elements removed from the head of the queue, and insert elements in the return value to the tail of the queue.
void	finish()
com.google.common.util.concurrent.ListenableFuture<List<T>>	getBatchAsync(int maxSize)
boolean	isFinished() Returns true if all future attempts to retrieve elements from this queue are guaranteed to return empty.
com.google.common.util.concurrent.ListenableFuture<?>	offer(T element)

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncQueue

public AsyncQueue(int targetQueueSize,
                  Executor executor)

Method Detail

isFinished

public boolean isFinished()

Returns true if all future attempts to retrieve elements from this queue are guaranteed to return empty.

finish

public void finish()

offer

public com.google.common.util.concurrent.ListenableFuture<?> offer(T element)

getBatchAsync

public com.google.common.util.concurrent.ListenableFuture<List<T>> getBatchAsync(int maxSize)

borrowBatchAsync

public <O> com.google.common.util.concurrent.ListenableFuture<O> borrowBatchAsync(int maxSize,
                                                                                  Function<List<T>,AsyncQueue.BorrowResult<T,O>> function)

Invoke function with up to maxSize elements removed from the head of the queue, and insert elements in the return value to the tail of the queue.

If no element is currently available, invocation of function will be deferred until some element is available, or no more elements will be. Spurious invocation of function is possible.

Insertion through return value of function will be effective even if finish() has been invoked. When borrow (of a non-empty list) is ongoing, isFinished() will return false. If an empty list is supplied to function, it must not return a result indicating intention to insert elements into the queue.