import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
import java.util.Map;
import javax.annotation.Nonnull;
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.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;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNodeFactory;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version;
/**
* 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, ModificationApplyOperation, Version)} 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> {
- static final Predicate<ModifiedNode> IS_TERMINAL_PREDICATE = new Predicate<ModifiedNode>() {
- @Override
- public boolean apply(@Nonnull final ModifiedNode input) {
- Preconditions.checkNotNull(input);
- switch (input.getOperation()) {
+ static final Predicate<ModifiedNode> IS_TERMINAL_PREDICATE = input -> {
+ Preconditions.checkNotNull(input);
+ switch (input.getOperation()) {
case DELETE:
case MERGE:
case WRITE:
case TOUCH:
case NONE:
return false;
- }
-
- throw new IllegalArgumentException(String.format("Unhandled modification type %s", input.getOperation()));
}
+
+ throw new IllegalArgumentException(String.format("Unhandled modification type %s", input.getOperation()));
};
- private static final int DEFAULT_CHILD_COUNT = 8;
private final Map<PathArgument, ModifiedNode> children;
private final Optional<TreeNode> original;
private NormalizedNode<?, ?> value;
private ModificationType modType;
+ // Alternative history introduced in WRITE nodes. Instantiated when we touch any child underneath such a node.
+ private TreeNode writtenOriginal;
+
+ // Internal cache for TreeNodes created as part of validation
+ private SchemaAwareApplyOperation validatedOp;
+ private Optional<TreeNode> validatedCurrent;
+ private TreeNode validatedNode;
+
private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original, final ChildTrackingPolicy childPolicy) {
this.identifier = identifier;
this.original = original;
-
- switch (childPolicy) {
- case NONE:
- children = Collections.emptyMap();
- break;
- case ORDERED:
- children = new LinkedHashMap<>(DEFAULT_CHILD_COUNT);
- break;
- case UNORDERED:
- children = new HashMap<>(DEFAULT_CHILD_COUNT);
- break;
- default:
- throw new IllegalArgumentException("Unsupported child tracking policy " + childPolicy);
- }
- }
-
- /**
- * Return the value which was written to this node.
- *
- * @return Currently-written value
- */
- public NormalizedNode<?, ?> getWrittenValue() {
- return value;
+ this.children = childPolicy.createMap();
}
@Override
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;
}
/**
*/
@Override
public Optional<ModifiedNode> getChild(final PathArgument child) {
- return Optional.<ModifiedNode> fromNullable(children.get(child));
+ return Optional.fromNullable(children.get(child));
+ }
+
+ private Optional<TreeNode> metadataFromSnapshot(@Nonnull final PathArgument child) {
+ return original.isPresent() ? original.get().getChild(child) : Optional.absent();
+ }
+
+ private Optional<TreeNode> metadataFromData(@Nonnull final PathArgument child, final Version modVersion) {
+ if (writtenOriginal == null) {
+ // Lazy instantiation, as we do not want do this for all writes. We are using the modification's version
+ // here, as that version is what the SchemaAwareApplyOperation will see when dealing with the resulting
+ // modifications.
+ writtenOriginal = TreeNodeFactory.createTreeNode(value, modVersion);
+ }
+
+ return writtenOriginal.getChild(child);
+ }
+
+ /**
+ * Determine the base tree node we are going to apply the operation to. This is not entirely trivial because
+ * both DELETE and WRITE operations unconditionally detach their descendants from the original snapshot, so we need
+ * to take the current node's operation into account.
+ *
+ * @param child Child we are looking to modify
+ * @param modVersion Version allocated by the calling {@link InMemoryDataTreeModification}
+ * @return Before-image tree node as observed by that child.
+ */
+ private Optional<TreeNode> findOriginalMetadata(@Nonnull final PathArgument child, final Version modVersion) {
+ switch (operation) {
+ case DELETE:
+ // DELETE implies non-presence
+ return Optional.absent();
+ case NONE:
+ case TOUCH:
+ case MERGE:
+ return metadataFromSnapshot(child);
+ case WRITE:
+ // WRITE implies presence based on written data
+ return metadataFromData(child, modVersion);
+ }
+
+ throw new IllegalStateException("Unhandled node operation " + operation);
}
/**
* changes modification type to {@link ModificationType#SUBTREE_MODIFIED}
*
* @param child child identifier, may not be null
- * @param childPolicy child tracking policy for the node we are looking for
+ * @param childOper Child operation
+ * @param modVersion Version allocated by the calling {@link InMemoryDataTreeModification}
* @return {@link ModifiedNode} for specified child, with {@link #getOriginal()}
* containing child metadata if child was present in original data.
*/
- ModifiedNode modifyChild(@Nonnull final PathArgument child, @Nonnull final ChildTrackingPolicy childPolicy) {
+ ModifiedNode modifyChild(@Nonnull final PathArgument child, @Nonnull final ModificationApplyOperation childOper,
+ @Nonnull final Version modVersion) {
clearSnapshot();
if (operation == LogicalOperation.NONE) {
updateOperationType(LogicalOperation.TOUCH);
return potential;
}
- final Optional<TreeNode> currentMetadata;
- if (original.isPresent()) {
- final TreeNode orig = original.get();
- currentMetadata = orig.getChild(child);
- } else {
- currentMetadata = Optional.absent();
+ final Optional<TreeNode> currentMetadata = findOriginalMetadata(child, modVersion);
+
+
+ final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childOper.getChildPolicy());
+ 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()) {
+ childOper.mergeIntoModifiedNode(newlyCreated, childData.get(), modVersion);
+ }
}
- final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childPolicy);
children.put(child, newlyCreated);
return newlyCreated;
}
newType = LogicalOperation.DELETE;
break;
case MERGE:
+ // In case of merge - delete needs to be recored and must not to be changed into
+ // NONE, because lazy expansion of parent MERGE node would reintroduce it
+ // again.
+ newType = LogicalOperation.DELETE;
+ break;
case TOUCH:
case WRITE:
/*
* @param value
*/
void write(final NormalizedNode<?, ?> value) {
- clearSnapshot();
- updateOperationType(LogicalOperation.WRITE);
+ updateValue(LogicalOperation.WRITE, value);
children.clear();
- 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.
+ * Seal the modification node and prune any children which has not been modified.
+ *
+ * @param schema
*/
- void seal() {
+ void seal(final ModificationApplyOperation schema, final Version version) {
clearSnapshot();
+ writtenOriginal = null;
- // A TOUCH node without any children is a no-op
- if (operation == LogicalOperation.TOUCH && children.isEmpty()) {
- updateOperationType(LogicalOperation.NONE);
+ switch (operation) {
+ case TOUCH:
+ // A TOUCH node without any children is a no-op
+ if (children.isEmpty()) {
+ updateOperationType(LogicalOperation.NONE);
+ }
+ break;
+ case WRITE:
+ // A WRITE can collapse all of its children
+ if (!children.isEmpty()) {
+ value = schema.apply(this, getOriginal(), version).get().getData();
+ children.clear();
+ }
+
+ schema.verifyStructure(value, true);
+ break;
+ default:
+ break;
}
}
return snapshot;
}
- private void updateOperationType(final LogicalOperation type) {
+ void updateOperationType(final LogicalOperation type) {
operation = type;
modType = null;
+
+ // Make sure we do not reuse previously-instantiated data-derived metadata
+ writtenOriginal = null;
clearSnapshot();
}
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);
}
+
+ void setValidatedNode(final SchemaAwareApplyOperation op, final Optional<TreeNode> current, final TreeNode node) {
+ this.validatedOp = Preconditions.checkNotNull(op);
+ this.validatedCurrent = Preconditions.checkNotNull(current);
+ this.validatedNode = Preconditions.checkNotNull(node);
+ }
+
+ TreeNode getValidatedNode(final SchemaAwareApplyOperation op, final Optional<TreeNode> current) {
+ return op.equals(validatedOp) && current.equals(validatedCurrent) ? validatedNode : null;
+ }
}