Package org.opendaylight.mdsal.dom.spi.store

Class SnapshotBackedReadTransaction<T>

java.lang.Object

org.opendaylight.mdsal.dom.spi.store.AbstractDOMStoreTransaction<T>

org.opendaylight.mdsal.dom.spi.store.SnapshotBackedReadTransaction<T>

Type Parameters:

T - identifier type

All Implemented Interfaces:

AutoCloseable, DOMStoreReadTransaction, DOMStoreTransaction, SnapshotBackedTransaction, Identifiable<Object>

@Beta
public final class SnapshotBackedReadTransaction<T>
extends AbstractDOMStoreTransaction<T>
implements DOMStoreReadTransaction, SnapshotBackedTransaction

Implementation of read-only transaction backed by DataTreeSnapshot which delegates most of its calls to similar methods provided by underlying snapshot.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SnapshotBackedReadTransaction.TransactionClosePrototype<T>	Prototype implementation of close().

Method Summary

Modifier and Type	Method	Description
void	close()
FluentFuture<Boolean>	exists(YangInstanceIdentifier path)	Checks if data is available in the logical data store located at provided path.
Optional<DataTreeSnapshot>	getSnapshot()	Returns the DataTreeSnapshot underlying this transaction.
FluentFuture<Optional<NormalizedNode>>	read(YangInstanceIdentifier path)	Reads data from provided logical data store located at provided path.

Methods inherited from class org.opendaylight.mdsal.dom.spi.store.AbstractDOMStoreTransaction

addToStringAttributes, getDebugContext, getIdentifier, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.opendaylight.mdsal.dom.spi.store.DOMStoreReadTransaction

execute

Methods inherited from interface org.opendaylight.mdsal.dom.spi.store.DOMStoreTransaction

getIdentifier

Method Detail

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DOMStoreTransaction

read

public FluentFuture<Optional<NormalizedNode>> read(YangInstanceIdentifier path)

Description copied from interface: DOMStoreReadTransaction

Reads data from provided logical data store located at provided path.

Specified by:

read in interface DOMStoreReadTransaction

Parameters:

path - Path which uniquely identifies subtree which client want to read

Returns:

a FluentFuture containing the result of the read. The Future blocks until the commit operation is complete. Once complete:

• If the data at the supplied path exists, the Future returns an Optional object containing the data.
• If the data at the supplied path does not exist, the Future returns Optional.empty().
• If the read of the data fails, the Future will fail with a ReadFailedException or an exception derived from ReadFailedException.

exists

public FluentFuture<Boolean> exists(YangInstanceIdentifier path)

Description copied from interface: DOMStoreReadTransaction

Checks if data is available in the logical data store located at provided path.

Note: a successful result from this method makes no guarantee that a subsequent call to DOMStoreReadTransaction.read(org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier) will succeed. It is possible that the data resides in a data store on a remote node and, if that node goes down or a network failure occurs, a subsequent read would fail. Another scenario is if the data is deleted in between the calls to exists and read

Specified by:

exists in interface DOMStoreReadTransaction

Parameters:

path - Path which uniquely identifies subtree which client want to check existence of

Returns:

a FluentFuture containing the result of the check.

• If the data at the supplied path exists, the Future returns a Boolean whose value is true, false otherwise
• If checking for the data fails, the Future will fail with a ReadFailedException or an exception derived from ReadFailedException.

getSnapshot

public Optional<DataTreeSnapshot> getSnapshot()

Description copied from interface: SnapshotBackedTransaction

Returns the DataTreeSnapshot underlying this transaction. If this transaction is no longer open, Optional.empty() is returned.

Specified by:

getSnapshot in interface SnapshotBackedTransaction

Returns:

DataTreeSnapshot attached to this transaction if this transaction is still open.