Package kvd.client

Class KvdTransaction

java.lang.Object

kvd.client.KvdTransaction

All Implemented Interfaces:

AutoCloseable, KvdOperations

public class KvdTransaction
extends Object
implements KvdOperations, AutoCloseable

Transaction support, Unit of Work pattern

Method Summary

Modifier and Type	Method	Description
void	close()	Rollback and close transaction.
void	commit()	Commit and close the transaction.
Future<Boolean>	commitAsync()	Commit and close the transaction.
Future<Boolean>	containsAsync(byte[] key)	The returned Future evaluates to true if the key exists on the server, false otherwise
Future<InputStream>	getAsync(byte[] key)	Returns the value to which the specified key is mapped
boolean	lock(String key)
Future<Boolean>	lockAsync(byte[] key)	Obtain write lock on the key in the same way a put or remove operation would do.
Future<Boolean>	lockAsync(String key)	Obtain write lock on the key in the same way a put or remove operation would do.
Future<OutputStream>	putAsync(byte[] key)	Put a new value or replace an existing.
Future<Boolean>	removeAsync(byte[] key)	Removes the mapping for the specified key from the server.
void	rollback()	Rollback and close the transaction.
Future<Boolean>	rollbackAsync()	Rollback and close the transaction.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface kvd.client.KvdOperations

contains, contains, containsAsync, get, get, getAsync, getBytes, getString, getString, put, put, putAsync, putBytes, putString, putString, remove, remove, removeAsync

Method Detail

close

public void close()

Rollback and close transaction.

Specified by:

close in interface AutoCloseable

commitAsync

public Future<Boolean> commitAsync()

Commit and close the transaction. No further operations are allowed on the transaction after commit and the transaction object can be discarded.

Returns:

Future future that resolves to true or completes exceptionally.

commit

public void commit()

Commit and close the transaction. No further operations are allowed on the transaction after commit and the transaction object can be discarded.

rollbackAsync

public Future<Boolean> rollbackAsync()

Rollback and close the transaction. No further operations are allowed on the transaction after commit and the transaction object can be discarded.

Returns:

Future that resolves to true or completes exceptionally.

rollback

public void rollback()

Rollback and close the transaction. No further operations are allowed on the transaction after commit and the transaction object can be discarded.

putAsync

public Future<OutputStream> putAsync(byte[] key)

Description copied from interface: KvdOperations

Put a new value or replace an existing.

Specified by:

putAsync in interface KvdOperations

Parameters:

key - key with which the specified value is to be associated

Returns:

Future that evaluates either to an OutputStream to be used to stream the value in. or fails (e.g. on optimistic lock or deadlock). Close the OutputStream to signal that the value is complete.

getAsync

public Future<InputStream> getAsync(byte[] key)

Description copied from interface: KvdOperations

Returns the value to which the specified key is mapped

Specified by:

getAsync in interface KvdOperations

Parameters:

key - the key whose associated value is to be returned

Returns:

Future that evaluates either to an InputStream for keys that exist or null for keys that don't exist on the server.

containsAsync

public Future<Boolean> containsAsync(byte[] key)

Description copied from interface: KvdOperations

The returned Future evaluates to true if the key exists on the server, false otherwise

Specified by:

containsAsync in interface KvdOperations

Parameters:

key - The key whose presence is to be tested

Returns:

Future evaluates to true if the key exists on the server, false otherwise

removeAsync

public Future<Boolean> removeAsync(byte[] key)

Description copied from interface: KvdOperations

Removes the mapping for the specified key from the server.

Specified by:

removeAsync in interface KvdOperations

Parameters:

key - key whose mapping is to be removed

Returns:

Future which evaluates to true if the key/value was removed from the server, false otherwise.

lockAsync

public Future<Boolean> lockAsync(byte[] key)

Obtain write lock on the key in the same way a put or remove operation would do. It does not matter whether the key exists in the database or not.

Parameters:

key - the key to write lock

Returns:

Future that evaluates to true if concurrency mode is different from NONE or false for concurrency mode NONE or completes exceptionally if the key can't be write locked because either another transaction has a write lock on the key already in optimistic concurrency mode or a deadlock is detected in pessimistic concurrency mode

lockAsync

public Future<Boolean> lockAsync(String key)

Obtain write lock on the key in the same way a put or remove operation would do. It does not matter whether the key exists in the database or not.

Parameters:

key - the key to write lock

Returns:

Future that evaluates to true if concurrency mode is different from NONE or false for concurrency mode NONE or completes exceptionally if the key can't be write locked because either another transaction has a write lock on the key already in optimistic concurrency mode or a deadlock is detected in pessimistic concurrency mode

lock

public boolean lock(String key)

Parameters:

key - the key to write lock

Returns:

see lockAsync(String)

toString

public String toString()

Overrides:

toString in class Object