BUG-509: Move DataTree concepts into separate package

[controller.git] / opendaylight / md-sal / sal-dom-broker / src / main / java / org / opendaylight / controller / md / sal / dom / store / impl / tree / data / InMemoryDataTree.java

diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTree.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTree.java
new file mode 100644 (file)
index 0000000..1f2a775
--- /dev/null
+++ b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTree.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.md.sal.dom.store.impl.tree.data;
+
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataPreconditionFailedException;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTree;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeCandidate;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeModification;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreUtils;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+
+/**
+ * Read-only snapshot of the data tree.
+ */
+final class InMemoryDataTree implements DataTree {
+    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 StoreMetadataNode rootNode;
+    private SchemaContext currentSchemaContext;
+
+    public InMemoryDataTree(StoreMetadataNode rootNode, final SchemaContext schemaContext) {
+        this.rootNode = Preconditions.checkNotNull(rootNode);
+        this.currentSchemaContext = schemaContext;
+    }
+
+    @Override
+       public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
+        Preconditions.checkNotNull(newSchemaContext);
+
+        LOG.info("Attepting to install schema context {}", newSchemaContext);
+
+        /*
+         * FIXME: we should walk the schema contexts, both current and new and see
+         *        whether they are compatible here. Reject incompatible changes.
+         */
+
+        // Ready to change the context now, make sure no operations are running
+        rwLock.writeLock().lock();
+        try {
+            this.currentSchemaContext = newSchemaContext;
+        } finally {
+            rwLock.writeLock().unlock();
+        }
+    }
+
+    @Override
+       public InMemoryDataTreeSnapshot takeSnapshot() {
+        rwLock.readLock().lock();
+        try {
+            return new InMemoryDataTreeSnapshot(currentSchemaContext, rootNode);
+        } finally {
+            rwLock.readLock().unlock();
+        }
+    }
+
+       @Override
+       public void validate(DataTreeModification modification) throws DataPreconditionFailedException {
+               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.of(rootNode));
+       }
+
+       @Override
+       public synchronized DataTreeCandidate prepare(DataTreeModification modification) {
+               Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
+
+               final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
+               final NodeModification root = m.getRootModification();
+
+        if (root.getModificationType() == ModificationType.UNMODIFIED) {
+               return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
+        }
+
+        rwLock.writeLock().lock();
+        try {
+               // FIXME: rootNode needs to be a read-write snapshot here...
+               final Optional<StoreMetadataNode> newRoot = m.getStrategy().apply(m.getRootModification(), Optional.of(rootNode), StoreUtils.increase(rootNode.getSubtreeVersion()));
+               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();
+        }
+       }
+
+       @Override
+       public synchronized void commit(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 Store snapshot version: {} with version:{}", rootNode.getSubtreeVersion(), c.getAfterRoot().getSubtreeVersion());
+
+        if (LOG.isTraceEnabled()) {
+            LOG.trace("Data Tree is {}", StoreUtils.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 snapshot %s and transaction snapshot %s differ.", rootNode, c.getBeforeRoot()));
+            this.rootNode = c.getAfterRoot();
+        } finally {
+            rwLock.writeLock().unlock();
+        }
+       }
+}