org.opendaylight.mdsal.binding.api

Interface ReadOperations

All Known Subinterfaces:

ReadTransaction, ReadWriteOperations, ReadWriteTransaction

All Known Implementing Classes:

ForwardingReadTransaction, ForwardingReadWriteTransaction

public interface ReadOperations

Read-like operations supported by ReadTransaction and ReadWriteTransaction. This interface defines the operations without a tie-in with lifecycle management.

Method Summary

Modifier and Type	Method and Description
default @NonNull com.google.common.util.concurrent.FluentFuture<Boolean>	exists(@NonNull LogicalDatastoreType store, @NonNull InstanceIdentifier<?> path) Determines if data data exists in the provided logical data store located at the provided path.
<T extends DataObject> @NonNull com.google.common.util.concurrent.FluentFuture<Optional<T>>	read(@NonNull LogicalDatastoreType store, @NonNull InstanceIdentifier<T> path) Reads data from the provided logical data store located at the provided path.

Method Detail

read

<T extends DataObject> @NonNull com.google.common.util.concurrent.FluentFuture<Optional<T>> read(@NonNull LogicalDatastoreType store,
                                                                                                 @NonNull InstanceIdentifier<T> path)

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

If the target is a subtree, then the whole subtree is read (and will be accessible from the returned data object).

Parameters:

store - Logical data store from which read should occur.

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 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.

Throws:

NullPointerException - if any of the arguments is null

IllegalArgumentException - if the path is InstanceIdentifier.isWildcarded()

exists

default @NonNull com.google.common.util.concurrent.FluentFuture<Boolean> exists(@NonNull LogicalDatastoreType store,
                                                                                @NonNull InstanceIdentifier<?> path)

Determines if data data exists in the provided logical data store located at the provided path.

Default implementation just delegates to read(LogicalDatastoreType, InstanceIdentifier). Implementations are recommended to override with a more efficient implementation.

Parameters:

store - Logical data store from which read should occur.

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

Returns:

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

• If the data at the supplied path exists, the Future returns Boolean.TRUE.
• If the data at the supplied path does not exist, the Future returns Boolean.FALSE.
• If the check fails, the Future will fail with a ReadFailedException or an exception derived from ReadFailedException.

Throws:

NullPointerException - if any of the arguments is null

IllegalArgumentException - if the path is InstanceIdentifier.isWildcarded() and the implementation does not support evaluating wildcards.