*/
package org.opendaylight.yangtools.yang.data.impl.schema.tree;
+import com.google.common.base.MoreObjects;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import java.util.Collections;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
-
/**
* Read-only snapshot of the data tree.
*/
final class InMemoryDataTree implements DataTree {
+ private static final YangInstanceIdentifier PUBLIC_ROOT_PATH = YangInstanceIdentifier.create(Collections.<PathArgument>emptyList());
+ private static final AtomicReferenceFieldUpdater<InMemoryDataTree, DataTreeState> STATE_UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(InMemoryDataTree.class, DataTreeState.class, "state");
private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
- private static final InstanceIdentifier PUBLIC_ROOT_PATH = InstanceIdentifier.builder().build();
- private final ReadWriteLock rwLock = new ReentrantReadWriteLock(true);
- private ModificationApplyOperation applyOper = new AlwaysFailOperation();
- private SchemaContext currentSchemaContext;
- private TreeNode rootNode;
+ /**
+ * Current data store state generation.
+ */
+ private volatile DataTreeState state;
public InMemoryDataTree(final TreeNode rootNode, final SchemaContext schemaContext) {
- this.rootNode = Preconditions.checkNotNull(rootNode);
-
+ state = DataTreeState.createInitial(rootNode);
if (schemaContext != null) {
- // Also sets applyOper
setSchemaContext(schemaContext);
}
}
+ /*
+ * This method is synchronized to guard against user attempting to install
+ * multiple contexts. Otherwise it runs in a lock-free manner.
+ */
@Override
public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
Preconditions.checkNotNull(newSchemaContext);
- LOG.info("Attepting to install schema context {}", newSchemaContext);
+ LOG.info("Attempting to install schema contexts");
+ LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
- /*
- * FIXME: we should walk the schema contexts, both current and new and see
- * whether they are compatible here. Reject incompatible changes.
- */
+ final SchemaAwareApplyOperation operation = SchemaAwareApplyOperation.from(newSchemaContext);
- // Instantiate new apply operation, this still may fail
- final ModificationApplyOperation newApplyOper = SchemaAwareApplyOperation.from(newSchemaContext);
-
- // Ready to change the context now, make sure no operations are running
- rwLock.writeLock().lock();
- try {
- this.applyOper = newApplyOper;
- this.currentSchemaContext = newSchemaContext;
- } finally {
- rwLock.writeLock().unlock();
- }
+ DataTreeState currentState, newState;
+ do {
+ currentState = state;
+ newState = currentState.withSchemaContext(newSchemaContext, operation);
+ } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
}
@Override
public InMemoryDataTreeSnapshot takeSnapshot() {
- rwLock.readLock().lock();
- try {
- return new InMemoryDataTreeSnapshot(currentSchemaContext, rootNode, applyOper);
- } finally {
- rwLock.readLock().unlock();
- }
+ return state.newSnapshot();
}
@Override
public void validate(final DataTreeModification modification) throws DataValidationFailedException {
Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
-
final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
- m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(rootNode));
+
+ m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(state.getRoot()));
}
@Override
- public synchronized DataTreeCandidate prepare(final DataTreeModification modification) {
+ public DataTreeCandidate prepare(final DataTreeModification modification) {
Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
}
- rwLock.writeLock().lock();
- try {
- final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
- Optional.<TreeNode>of(rootNode), rootNode.getSubtreeVersion().next());
- Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
- return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, rootNode, newRoot.get());
- } finally {
- rwLock.writeLock().unlock();
- }
+ final TreeNode currentRoot = state.getRoot();
+ final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
+ Optional.<TreeNode>of(currentRoot), m.getVersion());
+ Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
+ return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, currentRoot, newRoot.get());
}
@Override
- public synchronized void commit(final DataTreeCandidate candidate) {
+ public void commit(final DataTreeCandidate candidate) {
if (candidate instanceof NoopDataTreeCandidate) {
return;
}
Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
- LOG.debug("Updating datastore from {} to {}", rootNode, c.getAfterRoot());
-
if (LOG.isTraceEnabled()) {
- LOG.trace("Data Tree is {}", StoreUtils.toStringTree(c.getAfterRoot().getData()));
+ LOG.trace("Data Tree is {}", NormalizedNodes.toStringTree(c.getAfterRoot().getData()));
}
- // Ready to change the context now, make sure no operations are running
- rwLock.writeLock().lock();
- try {
- Preconditions.checkState(c.getBeforeRoot() == rootNode,
- String.format("Store tree %s and candidate base %s differ.", rootNode, c.getBeforeRoot()));
- this.rootNode = c.getAfterRoot();
- } finally {
- rwLock.writeLock().unlock();
- }
+ final TreeNode newRoot = c.getAfterRoot();
+ DataTreeState currentState, newState;
+ do {
+ currentState = state;
+ final TreeNode currentRoot = currentState.getRoot();
+ LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
+
+ final TreeNode oldRoot = c.getBeforeRoot();
+ Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
+
+ newState = currentState.withRoot(newRoot);
+ LOG.trace("Updated state from {} to {}", currentState, newState);
+ } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this).add("object", super.toString()).add("state", state).toString();
}
}