com.github.basking2.sdsai.dsds.node.tx

Class Operation<KEY,VALUE>

java.lang.Object

com.github.basking2.sdsai.dsds.node.tx.Operation<KEY,VALUE>

Direct Known Subclasses:

CachedReadOperation

public abstract class Operation<KEY,VALUE>
extends java.lang.Object

An Operation is write, read, or other activity on a NodeStore which is included in a TransactionalNodeStore.

Constructor Summary

Constructors

Constructor and Description
Operation() Create a new operation with key and value set to null.
Operation(KEY key, VALUE value) Create a new operation with key and value set to the given parameters.

Method Summary

Modifier and Type	Method and Description
void	delete() Delete this operation.
protected abstract void	doExecute() Implementing classes should implement this method.
void	execute() Execute this operation if delete() has not been called on it.
KEY	getKey() Return a unique identifier that allows for tracking of this operation.
VALUE	getValue() Return the value of this operation if it is successful.
boolean	isDeleted() Return if this operation is deleted.

Methods inherited from class java.lang.Object

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

Constructor Detail

Operation

public Operation()

Create a new operation with key and value set to null.

Operation

public Operation(KEY key,
                 VALUE value)

Create a new operation with key and value set to the given parameters.

Method Detail

getValue

public VALUE getValue()

Return the value of this operation if it is successful. The null value is appropriate if this is a write operation where there is no data returned.

Returns:

VALUE of operation or null.

getKey

public KEY getKey()

Return a unique identifier that allows for tracking of this operation.

delete

public void delete()

Delete this operation. An operation structure typically has a lot of data associated with it. When a future operation obviates a previous operation that previous operation is not removed from the TransactionalNodeStore structure. Rather, its delete() method is called to release all unecessary data and mark the Operation as deleted. Deleted operations will not be executed when the TransactionalNodeStore is committed.

isDeleted

public boolean isDeleted()

Return if this operation is deleted.

execute

public void execute()

Execute this operation if delete() has not been called on it.

Throws:

java.lang.RuntimeException - or other unchecked exceptions to communicate failure.

doExecute

protected abstract void doExecute()

Implementing classes should implement this method. This is conditionally called by execute() if delete() has not been previously called.

Throws:

java.lang.RuntimeException - or other unchecked exceptions to communicate failure.