import org.opendaylight.yangtools.concepts.ListenerRegistration;
import org.opendaylight.yangtools.concepts.Path;
+/**
+ * Base interface that provides access to a conceptual data tree store and also provides the ability to
+ * subscribe for changes to data under a given branch of the tree.
+ *
+ * <p>
+ * All operations on the data tree are performed via one of the transactions:
+ * <ul>
+ * <li>Read-Only - allocated using {@link #newReadOnlyTransaction()}
+ * <li>Write-Only - allocated using {@link #newWriteOnlyTransaction()}
+ * <li>Read-Write - allocated using {@link #newReadWriteTransaction()}
+ * </ul>
+ *
+ * <p>
+ * These transactions provide a stable isolated view of data tree, which is
+ * guaranteed to be not affected by other concurrent transactions, until
+ * transaction is committed.
+ *
+ * <p>
+ * For a detailed explanation of how transaction are isolated and how transaction-local
+ * changes are committed to global data tree, see
+ * {@link AsyncReadTransaction}, {@link AsyncWriteTransaction},
+ * {@link AsyncReadWriteTransaction} and {@link AsyncWriteTransaction#submit()}.
+ *
+ *
+ * <p>
+ * It is strongly recommended to use the type of transaction, which
+ * provides only the minimal capabilities you need. This allows for
+ * optimizations at the data broker / data store level. For example,
+ * implementations may optimize the transaction for reading if they know ahead
+ * of time that you only need to read data - such as not keeping additional meta-data,
+ * which may be required for write transactions.
+ *
+ * <p>
+ * <b>Implementation Note:</b> This interface is not intended to be implemented
+ * by users of MD-SAL, but only to be consumed by them.
+ *
+ * @param <P>
+ * Type of path (subtree identifier), which represents location in
+ * tree
+ * @param <D>
+ * Type of data (payload), which represents data payload
+ */
public interface AsyncDataBroker<P extends Path<P>, D, L extends AsyncDataChangeListener<P, D>> extends //
AsyncDataTransactionFactory<P, D> {
/**
- *
* Scope of Data Change
*
+ * <p>
* Represents scope of data change (addition, replacement, deletion).
+ * The terminology for scope types is reused from LDAP.
+ *
+ * <h2>Examples</h2>
+ *
+ * <p>
+ * Following is an example model with comments describing what notifications
+ * you would receive based on the scope you specify, when you are
+ * registering for changes on container a.
+ *
+ * <pre>
+ * container a // scope BASE, ONE, SUBTREE
+ * leaf "foo" // scope ONE, SUBTREE
+ * container // scope ONE, SUBTREE
+ * leaf "bar" // scope SUBTREE
+ * list list // scope ONE, SUBTREE
+ * list [a] // scope SUBTREE
+ * id "a" // scope SUBTREE
+ * list [b] // scope SUBTREE
+ * id "b" // scope SUBTREE
+ * </pre>
*
- * The terminology for types is reused from LDAP
+ * <p>
+ * Following is an example model with comments describing what notifications
+ * you would receive based on the scope you specify, when you are
+ * registering for changes on list list (without specifying concrete item in
+ * the list).
*
- * @see http://www.idevelopment.info/data/LDAP/LDAP_Resources/SEARCH_Setting_the_SCOPE_Parameter.shtml
+ * <pre>
+ * list list // scope BASE, ONE, SUBTREE
+ * list [a] // scope ONE, SUBTREE
+ * id "a" // scope SUBTREE
+ * list [b] // scope ONE, SUBTREE
+ * id "b" // scope SUBTREE
+ * </pre>
+ *
+ *
+ * @see <a href="http://www.idevelopment.info/data/LDAP/LDAP_Resources/SEARCH_Setting_the_SCOPE_Parameter.shtml">LDAP</a>
*/
- public enum DataChangeScope {
+ enum DataChangeScope {
- /**
- * Represents only a direct change of the node, such as replacement of node,
- * addition or deletion.
- *
- */
- BASE,
- /**
- * Represent a change (addition,replacement,deletion)
- * of the node or one of it's direct childs.
- *
- */
- ONE,
- /**
- * Represents a change of the node or any of it's child nodes.
- *
- */
- SUBTREE
+ /**
+ * Represents only a direct change of the node, such as replacement of a node, addition or
+ * deletion. Note that, as described in {@link #ONE}, this may have counterintuitive
+ * interactions when viewed from a <i>binding aware</i> application, in particular when it
+ * pertains to lists.
+ *
+ */
+ BASE,
+ /**
+ * Represent a change (addition,replacement,deletion) of the node or one of its direct
+ * children.
+ *
+ * <p>
+ * Note that this is done in the <i>binding independent</i> data tree and so the behavior
+ * might be counterintuitive when used with <i>binding aware</i> interfaces particularly
+ * when it comes to lists. The list itself is a node in the <i>binding independent</i> tree,
+ * which means that if you want to listen on new elements you must listen on the list itself
+ * with the scope of {@link #ONE}.
+ *
+ * <p>
+ * As an example, in the below YANG snippet, listening on <tt>node</tt> with scope
+ * {@link #ONE} would tell you if the <tt>node-connector</tt> list was created or deleted,
+ * but not when elements were added or removed from the list assuming the list itself
+ * already existed.
+ *
+ * <pre>
+ * container nodes {
+ * list node {
+ * key "id";
+ * leaf id {
+ * type string;
+ * }
+ * list node-connector {
+ * leaf id {
+ * type string;
+ * }
+ * }
+ * }
+ * }
+ * </pre>
+ *
+ * <p>
+ * This scope is superset of {@link #BASE}.
+ *
+ */
+ ONE,
+ /**
+ * Represents a change of the node or any of or any of its child nodes,
+ * direct and nested.
+ *
+ * <p>
+ * This scope is superset of {@link #ONE} and {@link #BASE}.
+ *
+ */
+ SUBTREE
}
@Override
-
public AsyncReadTransaction<P, D> newReadOnlyTransaction();
+
AsyncReadOnlyTransaction<P, D> newReadOnlyTransaction();
@Override
- public AsyncReadWriteTransaction<P,D> newReadWriteTransaction();
+ AsyncReadWriteTransaction<P, D> newReadWriteTransaction();
@Override
-
public AsyncWriteTransaction<P, D> newWriteOnlyTransaction();
+ AsyncWriteTransaction<P, D> newWriteOnlyTransaction();
/**
- * Registers {@link DataChangeListener} for Data Change callbacks
- * which will be triggered on which will be triggered on the store
- *
- * @param store Logical store in which listener is registered.
- * @param path Path (subtree identifier) on which client listener will be invoked.
- * @param listener Instance of listener which should be invoked on
- * @param triggeringScope Scope of change which triggers callback.
- * @return Listener registration of the listener, call {@link ListenerRegistration#close()}
- * to stop delivery of change events.
+ * Registers a {@link AsyncDataChangeListener} to receive
+ * notifications when data changes under a given path in the conceptual data
+ * tree.
+ *
+ * <p>
+ * You are able to register for notifications for any node or subtree
+ * which can be reached via the supplied path.
+ *
+ * <p>
+ * If path type <code>P</code> allows it, you may specify paths up to the leaf nodes
+ * then it is possible to listen on leaf nodes.
+ *
+ * <p>
+ * You are able to register for data change notifications for a subtree even
+ * if it does not exist. You will receive notification once that node is created.
+ *
+ * <p>
+ * If there is any preexisting data in data tree on path for which you are
+ * registering, you will receive initial data change event, which will
+ * contain all preexisting data, marked as created.
+ *
+ * <p>
+ * You are also able to specify the scope of the changes you want to be
+ * notified.
+ *
+ * <p>
+ * Supported scopes are:
+ * <ul>
+ * <li>{@link DataChangeScope#BASE} - notification events will only be
+ * triggered when a node referenced by path is created, removed or replaced.
+ * <li>{@link DataChangeScope#ONE} - notifications events will only be
+ * triggered when a node referenced by path is created, removed or replaced,
+ * or any or any of its immediate children are created, updated or removed.
+ * <li>{@link DataChangeScope#SUBTREE} - notification events will be
+ * triggered when a node referenced by the path is created, removed
+ * or replaced or any of the children in its subtree are created, removed
+ * or replaced.
+ * </ul>
+ * See {@link DataChangeScope} for examples.
+ *
+ * <p>
+ * This method returns a {@link ListenerRegistration} object. To
+ * "unregister" your listener for changes call the "close" method on this
+ * returned object.
+ *
+ * <p>
+ * You MUST call close when you no longer need to receive notifications
+ * (such as during shutdown or for example if your bundle is shutting down).
+ *
+ * @param store
+ * Logical Data Store - Logical Datastore you want to listen for
+ * changes in. For example
+ * {@link LogicalDatastoreType#OPERATIONAL} or
+ * {@link LogicalDatastoreType#CONFIGURATION}
+ * @param path
+ * Path (subtree identifier) on which client listener will be
+ * invoked.
+ * @param listener
+ * Instance of listener which should be invoked on
+ * @param triggeringScope
+ * Scope of change which triggers callback.
+ * @return Listener registration object, which may be used to unregister
+ * your listener using {@link ListenerRegistration#close()} to stop
+ * delivery of change events.
*/
- ListenerRegistration<L> registerDataChangeListener(LogicalDatastoreType store, P path, L listener, DataChangeScope triggeringScope);
+ @Deprecated
+ default ListenerRegistration<L> registerDataChangeListener(LogicalDatastoreType store, P path, L listener,
+ DataChangeScope triggeringScope) {
+ throw new UnsupportedOperationException("Data change listeners are no longer supported.");
+ }
}
Code Review / controller.git / blobdiff