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, org.opendaylight.yangtools.concepts.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.

Method Summary

Modifier and Type	Method and Description
void	close()
com.google.common.util.concurrent.FluentFuture<Boolean>	exists(org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier path) Checks if data is available in the logical data store located at provided path.
Optional<org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot>	getSnapshot() Returns the DataTreeSnapshot underlying this transaction.
com.google.common.util.concurrent.FluentFuture<Optional<org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode<?,?>>>	read(org.opendaylight.yangtools.yang.data.api.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.DOMStoreTransaction

getIdentifier

Method Detail

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DOMStoreTransaction

read

public com.google.common.util.concurrent.FluentFuture<Optional<org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode<?,?>>> read(org.opendaylight.yangtools.yang.data.api.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 com.google.common.util.concurrent.FluentFuture<Boolean> exists(org.opendaylight.yangtools.yang.data.api.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<org.opendaylight.yangtools.yang.data.api.schema.tree.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.