org.apache.hadoop.fs.s3a.impl

Class ExecutingStoreOperation<T>

java.lang.Object

org.apache.hadoop.fs.s3a.impl.AbstractStoreOperation

org.apache.hadoop.fs.s3a.impl.ExecutingStoreOperation<T>

Type Parameters:

T - return type of executed operation.

Direct Known Subclasses:

DeleteOperation, RenameOperation

public abstract class ExecutingStoreOperation<T>
extends AbstractStoreOperation

A subclass of AbstractStoreOperation which provides a method execute() that may be invoked exactly once.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ExecutingStoreOperation(StoreContext storeContext) constructor.

Method Summary

Modifier and Type	Method and Description
abstract T	execute() Execute the operation.
protected void	executeOnlyOnce() Check that the operation has not been invoked twice.

Methods inherited from class org.apache.hadoop.fs.s3a.impl.AbstractStoreOperation

getStoreContext

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutingStoreOperation

protected ExecutingStoreOperation(StoreContext storeContext)

constructor.

Parameters:

storeContext - store context.

Method Detail

execute

public abstract T execute()
                   throws IOException

Execute the operation. Subclasses MUST call executeOnlyOnce() so as to force the (atomic) re-entrancy check.

Returns:

the result.

Throws:

IOException - IO problem

executeOnlyOnce

protected void executeOnlyOnce()

Check that the operation has not been invoked twice. This is an atomic check.

Throws:

IllegalStateException - on a second invocation.