import javax.annotation.concurrent.NotThreadSafe;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
-import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodeContainer;
import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
import org.opendaylight.yangtools.yang.data.api.schema.tree.StoreTreeNode;
import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
/**
* Node Modification Node and Tree
*
- * Tree which structurally resembles data tree and captures client modifications
- * to the data store tree.
+ * Tree which structurally resembles data tree and captures client modifications to the data store tree. This tree is
+ * lazily created and populated via {@link #modifyChild(PathArgument)} and {@link TreeNode} which represents original
+ * state as tracked by {@link #getOriginal()}.
*
- * This tree is lazily created and populated via {@link #modifyChild(PathArgument)}
- * and {@link TreeNode} which represents original state as tracked by {@link #getOriginal()}.
+ * The contract is that the state information exposed here preserves the temporal ordering of whatever modifications
+ * were executed. A child's effects pertain to data node as modified by its ancestors. This means that in order to
+ * reconstruct the effective data node presentation, it is sufficient to perform a depth-first pre-order traversal of
+ * the tree.
*/
@NotThreadSafe
final class ModifiedNode extends NodeModification implements StoreTreeNode<ModifiedNode> {
this.children = childPolicy.createMap();
}
- /**
- * Return the value which was written to this node.
- *
- * @return Currently-written value
- */
- public NormalizedNode<?, ?> getWrittenValue() {
- return value;
- }
-
@Override
public PathArgument getIdentifier() {
return identifier;
}
+ @Override
+ LogicalOperation getOperation() {
+ return operation;
+ }
+
@Override
Optional<TreeNode> getOriginal() {
return original;
}
- @Override
- LogicalOperation getOperation() {
- return operation;
+ /**
+ * Return the value which was written to this node. The returned object is only valid for
+ * {@link LogicalOperation#MERGE} and {@link LogicalOperation#WRITE}.
+ * operations. It should only be consulted when this modification is going to end up being
+ * {@link ModificationType#WRITE}.
+ *
+ * @return Currently-written value
+ */
+ NormalizedNode<?, ?> getWrittenValue() {
+ return value;
}
/**
return Optional.absent();
case NONE:
case TOUCH:
- return metadataFromSnapshot(child);
case MERGE:
- // MERGE is half-way between TOUCH and WRITE. If the child exists in data, it behaves as a WRITE, otherwise
- // it behaves as a TOUCH
- if (NormalizedNodes.findNode(value, child).isPresent()) {
- return metadataFromData(child, modVersion);
- } else {
- return metadataFromSnapshot(child);
- }
+ return metadataFromSnapshot(child);
case WRITE:
// WRITE implies presence based on written data
return metadataFromData(child, modVersion);
final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childPolicy);
+ if (operation == LogicalOperation.MERGE && value != null) {
+ /*
+ * We are attempting to modify a previously-unmodified part of a MERGE node. If the
+ * value contains this component, we need to materialize it as a MERGE modification.
+ */
+ @SuppressWarnings({ "rawtypes", "unchecked" })
+ final Optional<NormalizedNode<?, ?>> childData = ((NormalizedNodeContainer)value).getChild(child);
+ if (childData.isPresent()) {
+ newlyCreated.updateValue(LogicalOperation.MERGE, childData.get());
+ }
+ }
+
children.put(child, newlyCreated);
return newlyCreated;
}
* @param value
*/
void write(final NormalizedNode<?, ?> value) {
- pushWrite(value);
+ updateValue(LogicalOperation.WRITE, value);
children.clear();
}
- // Promote the node to write, but do not lose children
- void pushWrite(final NormalizedNode<?, ?> value) {
- clearSnapshot();
- updateOperationType(LogicalOperation.WRITE);
- this.value = value;
- }
-
- void merge(final NormalizedNode<?, ?> value) {
- clearSnapshot();
- updateOperationType(LogicalOperation.MERGE);
-
- /*
- * Blind overwrite of any previous data is okay, no matter whether the node
- * is simple or complex type.
- *
- * If this is a simple or complex type with unkeyed children, this merge will
- * be turned into a write operation, overwriting whatever was there before.
- *
- * If this is a container with keyed children, there are two possibilities:
- * - if it existed before, this value will never be consulted and the children
- * will get explicitly merged onto the original data.
- * - if it did not exist before, this value will be used as a seed write and
- * children will be merged into it.
- * In either case we rely on OperationWithModification to manipulate the children
- * before calling this method, so unlike a write we do not want to clear them.
- */
- this.value = value;
- }
-
/**
* Seal the modification node and prune any children which has not been modified.
*
return snapshot;
}
- private void updateOperationType(final LogicalOperation type) {
+ void updateOperationType(final LogicalOperation type) {
operation = type;
modType = null;
modType = type;
}
+ /**
+ * Update this node's value and operation type without disturbing any of its child modifications.
+ *
+ * @param type New operation type
+ * @param value New node value
+ */
+ void updateValue(final LogicalOperation type, final NormalizedNode<?, ?> value) {
+ this.value = Preconditions.checkNotNull(value);
+ updateOperationType(type);
+ }
+
/**
* Return the physical modification done to data. May return null if the
* operation has not been applied to the underlying tree. This is different
return modType;
}
- /**
- * Create a node which will reflect the state of this node, except it will behave as newly-written
- * value. This is useful only for merge validation.
- *
- * @param value Value associated with the node
- * @return An isolated node. This node should never reach a datatree.
- */
- ModifiedNode asNewlyWritten(final NormalizedNode<?, ?> value) {
- /*
- * We are instantiating an "equivalent" of this node. Currently the only callsite does not care
- * about the actual iteration order, so we do not have to specify the same tracking policy as
- * we were instantiated with. Since this is the only time we need to know that policy (it affects
- * only things in constructor), we do not want to retain it (saves some memory on per-instance
- * basis).
- *
- * We could reconstruct it using two instanceof checks (to undo what the constructor has done),
- * which would give perfect results. The memory saving would be at most 32 bytes of a short-lived
- * object, so let's not bother with that.
- */
- final ModifiedNode ret = new ModifiedNode(getIdentifier(), Optional.<TreeNode>absent(), ChildTrackingPolicy.UNORDERED);
- ret.write(value);
- return ret;
- }
-
public static ModifiedNode createUnmodified(final TreeNode metadataTree, final ChildTrackingPolicy childPolicy) {
return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), childPolicy);
}
Code Review / yangtools.git / blobdiff