*/
package org.opendaylight.yangtools.yang.data.impl.schema.tree;
-import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
-import com.google.common.base.Predicate;
+import static com.google.common.base.Verify.verifyNotNull;
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.base.MoreObjects.ToStringHelper;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
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 java.util.Optional;
+import java.util.function.Predicate;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
+import org.opendaylight.yangtools.yang.data.api.schema.DistinctNodeContainer;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
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
+ * Node Modification Node and Tree.
*
- * Tree which structurally resembles data tree and captures client modifications
- * to the data store tree.
+ * <p>
+ * 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()}.
+ * <p>
+ * 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 -> {
+ requireNonNull(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()));
+ default:
+ throw new IllegalArgumentException("Unhandled modification type " + input.getOperation());
}
};
private final Map<PathArgument, ModifiedNode> children;
- private final Optional<TreeNode> original;
+ private final Optional<? extends TreeNode> original;
private final PathArgument identifier;
private LogicalOperation operation = LogicalOperation.NONE;
private Optional<TreeNode> snapshotCache;
- private NormalizedNode<?, ?> value;
+ private NormalizedNode value;
private ModificationType modType;
- private ModifiedNode(final PathArgument identifier, final Optional<TreeNode> original, final ChildTrackingPolicy childPolicy) {
- this.identifier = identifier;
- this.original = original;
+ // Alternative history introduced in WRITE nodes. Instantiated when we touch any child underneath such a node.
+ private TreeNode writtenOriginal;
- switch (childPolicy) {
- case NONE:
- children = Collections.emptyMap();
- break;
- case ORDERED:
- children = new LinkedHashMap<>();
- break;
- case UNORDERED:
- children = new HashMap<>();
- break;
- default:
- throw new IllegalArgumentException("Unsupported child tracking policy " + childPolicy);
- }
- }
+ // Internal cache for TreeNodes created as part of validation
+ private ModificationApplyOperation validatedOp;
+ private Optional<? extends TreeNode> validatedCurrent;
+ private Optional<? extends TreeNode> validatedNode;
- /**
- * Return the value which was written to this node.
- *
- * @return Currently-written value
- */
- public NormalizedNode<?, ?> getWrittenValue() {
- return value;
+ private ModifiedNode(final PathArgument identifier, final Optional<? extends TreeNode> original,
+ final ChildTrackingPolicy childPolicy) {
+ this.identifier = identifier;
+ this.original = original;
+ this.children = childPolicy.createMap();
}
@Override
}
@Override
- Optional<TreeNode> getOriginal() {
- return original;
+ LogicalOperation getOperation() {
+ return operation;
}
@Override
- LogicalOperation getOperation() {
- return operation;
+ Optional<? extends TreeNode> getOriginal() {
+ return original;
}
/**
+ * 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}.
*
- * Returns child modification if child was modified
- *
- * @return Child modification if direct child or it's subtree
- * was modified.
+ * @return Currently-written value
+ */
+ @NonNull NormalizedNode getWrittenValue() {
+ return verifyNotNull(value);
+ }
+
+ /**
+ * Returns child modification if child was modified.
*
+ * @return Child modification if direct child or it's subtree was modified.
*/
@Override
- public Optional<ModifiedNode> getChild(final PathArgument child) {
- return Optional.<ModifiedNode> fromNullable(children.get(child));
+ public ModifiedNode childByArg(final PathArgument arg) {
+ return children.get(arg);
+ }
+
+ private Optional<? extends TreeNode> metadataFromSnapshot(final @NonNull PathArgument child) {
+ return original.isPresent() ? original.get().findChildByArg(child) : Optional.empty();
+ }
+
+ private Optional<? extends TreeNode> metadataFromData(final @NonNull 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.findChildByArg(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<? extends TreeNode> findOriginalMetadata(final @NonNull PathArgument child,
+ final Version modVersion) {
+ switch (operation) {
+ case DELETE:
+ // DELETE implies non-presence
+ return Optional.empty();
+ case NONE:
+ case TOUCH:
+ case MERGE:
+ return metadataFromSnapshot(child);
+ case WRITE:
+ // WRITE implies presence based on written data
+ return metadataFromData(child, modVersion);
+ default:
+ throw new IllegalStateException("Unhandled node operation " + operation);
+ }
+ }
+
+ /**
* Returns child modification if child was modified, creates {@link ModifiedNode}
- * for child otherwise.
- *
- * If this node's {@link ModificationType} is {@link ModificationType#UNMODIFIED}
- * changes modification type to {@link ModificationType#SUBTREE_MODIFIED}
+ * for child otherwise. If this node's {@link ModificationType} is {@link ModificationType#UNMODIFIED}
+ * 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(final @NonNull PathArgument child, final @NonNull ModificationApplyOperation childOper,
+ final @NonNull 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<? extends 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 NormalizedNode childData = ((DistinctNodeContainer)value).childByArg(child);
+ if (childData != null) {
+ childOper.mergeIntoModifiedNode(newlyCreated, childData, modVersion);
+ }
}
- final ModifiedNode newlyCreated = new ModifiedNode(child, currentMetadata, childPolicy);
children.put(child, newlyCreated);
return newlyCreated;
}
/**
- * Returns all recorded direct child modification
+ * Returns all recorded direct child modifications.
*
* @return all recorded direct child modifications
*/
final LogicalOperation newType;
switch (operation) {
- case DELETE:
- case NONE:
- // We need to record this delete.
- newType = LogicalOperation.DELETE;
- break;
- case MERGE:
- case TOUCH:
- case WRITE:
- /*
- * We are canceling a previous modification. This is a bit tricky,
- * as the original write may have just introduced the data, or it
- * may have modified it.
- *
- * As documented in BUG-2470, a delete of data introduced in this
- * transaction needs to be turned into a no-op.
- */
- newType = original.isPresent() ? LogicalOperation.DELETE : LogicalOperation.NONE;
- break;
- default:
- throw new IllegalStateException("Unhandled deletion of node with " + operation);
+ case DELETE:
+ case NONE:
+ // We need to record this delete.
+ 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:
+ /*
+ * We are canceling a previous modification. This is a bit tricky, as the original write may have just
+ * introduced the data, or it may have modified it.
+ *
+ * As documented in BUG-2470, a delete of data introduced in this transaction needs to be turned into
+ * a no-op.
+ */
+ newType = original.isPresent() ? LogicalOperation.DELETE : LogicalOperation.NONE;
+ break;
+ default:
+ throw new IllegalStateException("Unhandled deletion of node with " + operation);
}
clearSnapshot();
/**
* Records a write for associated node.
*
- * @param value
+ * @param newValue new value
*/
- void write(final NormalizedNode<?, ?> value) {
- clearSnapshot();
- updateOperationType(LogicalOperation.WRITE);
+ void write(final NormalizedNode newValue) {
+ updateValue(LogicalOperation.WRITE, newValue);
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 associated apply operation
+ * @param version target version
*/
- 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).map(TreeNode::getData).orElse(null);
+ children.clear();
+ }
+
+ if (value == null) {
+ // The write has ended up being empty, such as a write of an empty list.
+ updateOperationType(LogicalOperation.DELETE);
+ } else {
+ schema.fullVerifyStructure(value);
+ }
+ break;
+ default:
+ break;
}
}
}
Optional<TreeNode> setSnapshot(final Optional<TreeNode> snapshot) {
- snapshotCache = Preconditions.checkNotNull(snapshot);
+ snapshotCache = requireNonNull(snapshot);
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();
}
@Override
public String toString() {
- return "NodeModification [identifier=" + identifier + ", modificationType="
- + operation + ", childModification=" + children + "]";
+ final ToStringHelper helper = MoreObjects.toStringHelper(this).omitNullValues()
+ .add("identifier", identifier).add("operation", operation).add("modificationType", modType);
+ if (!children.isEmpty()) {
+ helper.add("childModification", children);
+ }
+ return helper.toString();
}
- void resolveModificationType(@Nonnull final ModificationType type) {
+ void resolveModificationType(final @NonNull ModificationType type) {
modType = type;
}
+ /**
+ * Update this node's value and operation type without disturbing any of its child modifications.
+ *
+ * @param type New operation type
+ * @param newValue New node value
+ */
+ void updateValue(final LogicalOperation type, final NormalizedNode newValue) {
+ this.value = requireNonNull(newValue);
+ 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;
}
+ public static ModifiedNode createUnmodified(final TreeNode metadataTree, final ChildTrackingPolicy childPolicy) {
+ return new ModifiedNode(metadataTree.getIdentifier(), Optional.of(metadataTree), childPolicy);
+ }
+
+ void setValidatedNode(final ModificationApplyOperation op, final Optional<? extends TreeNode> current,
+ final Optional<? extends TreeNode> node) {
+ this.validatedOp = requireNonNull(op);
+ this.validatedCurrent = requireNonNull(current);
+ this.validatedNode = requireNonNull(node);
+ }
+
/**
- * 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.
+ * Acquire pre-validated node assuming a previous operation and node. This is a counterpart to
+ * {@link #setValidatedNode(ModificationApplyOperation, Optional, Optional)}.
*
- * @param value Value associated with the node
- * @return An isolated node. This node should never reach a datatree.
+ * @param op Currently-executing operation
+ * @param current Currently-used tree node
+ * @return {@code null} if there is a mismatch with previously-validated node (if present) or the result of previous
+ * validation.
*/
- 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);
+ @SuppressFBWarnings(value = "NP_OPTIONAL_RETURN_NULL",
+ justification = "The contract is package-internal and well documented, we do not need a separate wrapper")
+ @Nullable Optional<? extends TreeNode> getValidatedNode(final ModificationApplyOperation op,
+ final Optional<? extends TreeNode> current) {
+ return op.equals(validatedOp) && current.equals(validatedCurrent) ? validatedNode : null;
}
}