*/
@Beta
public final class ChildSchemaNodeNamespace<D extends DeclaredStatement<QName>, E extends EffectiveStatement<QName, D>>
- extends NamespaceBehaviour<QName, StmtContext<?, D, E>, ChildSchemaNodeNamespace<D, E>>
- implements StatementNamespace<QName, D, E> {
-
+ extends NamespaceBehaviour<QName, StmtContext<?, D, E>, ChildSchemaNodeNamespace<D, E>>
+ implements StatementNamespace<QName, D, E> {
public ChildSchemaNodeNamespace() {
super((Class) ChildSchemaNodeNamespace.class);
}
@Override
public StmtContext<?, D, E> getFrom(final NamespaceStorageNode storage, final QName key) {
- return globalOrStatementSpecific(storage).getFromLocalStorage(getIdentifier(), key);
+ // Get the backing storage node for the requested storage
+ final NamespaceStorageNode storageNode = globalOrStatementSpecific(storage);
+ // Check try to look up existing node
+ final StmtContext<?, D, E> existing = storageNode.getFromLocalStorage(getIdentifier(), key);
+
+ // An existing node takes precedence, if it does not exist try to request it
+ return existing != null ? existing : requestFrom(storageNode, key);
+ }
+
+ private static <D extends DeclaredStatement<QName>, E extends EffectiveStatement<QName, D>>
+ StmtContext<?, D, E> requestFrom(final NamespaceStorageNode storageNode, final QName key) {
+ return storageNode instanceof OnDemandSchemaTreeStorageNode
+ ? ((OnDemandSchemaTreeStorageNode) storageNode).requestSchemaTreeChild(key) : null;
}
@Override
import static java.util.Objects.requireNonNull;
+import com.google.common.annotations.Beta;
import com.google.common.base.MoreObjects.ToStringHelper;
import com.google.common.base.Verify;
import java.util.Map;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.yangtools.concepts.AbstractIdentifiable;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
+import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
import org.opendaylight.yangtools.yang.model.api.meta.IdentifierNamespace;
/**
V value);
}
+ /**
+ * Interface implemented by {@link NamespaceStorageNode}s which support dynamic addition of child elements as they
+ * are requested. This means that such a node can, defer creation of child namespace storage nodes, in effect lazily
+ * expanding this namespace on an if-needed basis.
+ */
+ @Beta
+ public interface OnDemandSchemaTreeStorageNode extends NamespaceStorageNode {
+ /**
+ * Request that a new member of this node's schema tree statement be added. Implementations are required to
+ * perform lookup in their internal structure and create a child if tracktable. Resulting node is expected to
+ * have been registered with local storage, so that it is accessible through
+ * {@link #getFromLocalStorage(Class, Object)}.
+ *
+ * <p>
+ * This method must not change its mind about a child's presence -- once it returns non-present, it has to be
+ * always returning non-present.
+ *
+ * @param qname node identifier of the child being requested
+ * @return Requested child, if it is present.
+ */
+ <D extends DeclaredStatement<QName>, E extends EffectiveStatement<QName, D>>
+ @Nullable StmtContext<QName, D, E> requestSchemaTreeChild(QName qname);
+ }
+
protected NamespaceBehaviour(final Class<N> identifier) {
super(identifier);
}