Bug 499: Added support for change listeners.
[controller.git] / opendaylight / md-sal / sal-dom-broker / src / main / java / org / opendaylight / controller / md / sal / dom / store / impl / DataChangeEventResolver.java
diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/DataChangeEventResolver.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/DataChangeEventResolver.java
new file mode 100644 (file)
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@@ -0,0 +1,215 @@
+package org.opendaylight.controller.md.sal.dom.store.impl;
+
+import static org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.builder;
+import static org.opendaylight.controller.md.sal.dom.store.impl.StoreUtils.append;
+import static org.opendaylight.controller.md.sal.dom.store.impl.tree.TreeNodeUtils.getChild;
+
+import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
+import org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.Builder;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerRegistrationNode;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.NodeModification;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreMetadataNode;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerRegistrationNode.DataChangeListenerRegistration;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+
+public class DataChangeEventResolver {
+
+    private static final DOMImmutableDataChangeEvent NO_CHANGE = builder().build();
+    private InstanceIdentifier rootPath;
+    private ListenerRegistrationNode listenerRoot;
+    private NodeModification modificationRoot;
+    private Optional<StoreMetadataNode> beforeRoot;
+    private Optional<StoreMetadataNode> afterRoot;
+    private final ImmutableList.Builder<ChangeListenerNotifyTask> tasks = ImmutableList.builder();
+
+    protected InstanceIdentifier getRootPath() {
+        return rootPath;
+    }
+
+    protected DataChangeEventResolver setRootPath(final InstanceIdentifier rootPath) {
+        this.rootPath = rootPath;
+        return this;
+    }
+
+    protected ListenerRegistrationNode getListenerRoot() {
+        return listenerRoot;
+    }
+
+    protected DataChangeEventResolver setListenerRoot(final ListenerRegistrationNode listenerRoot) {
+        this.listenerRoot = listenerRoot;
+        return this;
+    }
+
+    protected NodeModification getModificationRoot() {
+        return modificationRoot;
+    }
+
+    protected DataChangeEventResolver setModificationRoot(final NodeModification modificationRoot) {
+        this.modificationRoot = modificationRoot;
+        return this;
+    }
+
+    protected Optional<StoreMetadataNode> getBeforeRoot() {
+        return beforeRoot;
+    }
+
+    protected DataChangeEventResolver setBeforeRoot(final Optional<StoreMetadataNode> beforeRoot) {
+        this.beforeRoot = beforeRoot;
+        return this;
+    }
+
+    protected Optional<StoreMetadataNode> getAfterRoot() {
+        return afterRoot;
+    }
+
+    protected DataChangeEventResolver setAfterRoot(final Optional<StoreMetadataNode> afterRoot) {
+        this.afterRoot = afterRoot;
+        return this;
+    }
+
+    public Iterable<ChangeListenerNotifyTask> resolve() {
+        resolveAnyChangeEvent(rootPath, Optional.of(listenerRoot), modificationRoot, beforeRoot, afterRoot);
+        return tasks.build();
+    }
+
+    private DOMImmutableDataChangeEvent resolveAnyChangeEvent(final InstanceIdentifier path,
+            final Optional<ListenerRegistrationNode> listeners, final NodeModification modification,
+            final Optional<StoreMetadataNode> before, final Optional<StoreMetadataNode> after) {
+        // No listeners are present in listener registration subtree
+        // no before and after state is present
+        if (!before.isPresent() && !after.isPresent()) {
+            return NO_CHANGE;
+        }
+        switch (modification.getModificationType()) {
+        case SUBTREE_MODIFIED:
+            return resolveSubtreeChangeEvent(path, listeners, modification, before.get(), after.get());
+        case WRITE:
+            if (before.isPresent()) {
+                return resolveReplacedEvent(path, listeners, modification, before.get(), after.get());
+            } else {
+                return resolveCreateEvent(path, listeners, after.get());
+            }
+        case DELETE:
+            return resolveDeleteEvent(path, listeners, before.get());
+        default:
+            return NO_CHANGE;
+        }
+
+    }
+
+    /**
+     * Resolves create events deep down the interest listener tree.
+     *
+     *
+     * @param path
+     * @param listeners
+     * @param afterState
+     * @return
+     */
+    private DOMImmutableDataChangeEvent resolveCreateEvent(final InstanceIdentifier path,
+            final Optional<ListenerRegistrationNode> listeners, final StoreMetadataNode afterState) {
+        final NormalizedNode<?, ?> node = afterState.getData();
+        Builder builder = builder().setAfter(node).addCreated(path, node);
+
+        for (StoreMetadataNode child : afterState.getChildren()) {
+            PathArgument childId = child.getIdentifier();
+            Optional<ListenerRegistrationNode> childListeners = getChild(listeners, childId);
+
+            InstanceIdentifier childPath = StoreUtils.append(path, childId);
+            builder.merge(resolveCreateEvent(childPath, childListeners, child));
+        }
+        DOMImmutableDataChangeEvent event = builder.build();
+        if (listeners.isPresent()) {
+            addNotifyTask(listeners.get().getListeners(), event);
+        }
+        return event;
+    }
+
+    private DOMImmutableDataChangeEvent resolveDeleteEvent(final InstanceIdentifier path,
+            final Optional<ListenerRegistrationNode> listeners, final StoreMetadataNode beforeState) {
+        final NormalizedNode<?, ?> node = beforeState.getData();
+        Builder builder = builder().setBefore(node).addRemoved(path, node);
+
+        for (StoreMetadataNode child : beforeState.getChildren()) {
+            PathArgument childId = child.getIdentifier();
+            Optional<ListenerRegistrationNode> childListeners = getChild(listeners, childId);
+            InstanceIdentifier childPath = StoreUtils.append(path, childId);
+            builder.merge(resolveDeleteEvent(childPath, childListeners, child));
+        }
+        DOMImmutableDataChangeEvent event = builder.build();
+        if (listeners.isPresent()) {
+            addNotifyTask(listeners.get().getListeners(), event);
+        }
+        return event;
+
+    }
+
+    private DOMImmutableDataChangeEvent resolveSubtreeChangeEvent(final InstanceIdentifier path,
+            final Optional<ListenerRegistrationNode> listeners, final NodeModification modification,
+            final StoreMetadataNode before, final StoreMetadataNode after) {
+
+        Builder one = builder().setBefore(before.getData()).setAfter(after.getData());
+
+        Builder subtree = builder();
+
+        for (NodeModification childMod : modification.getModifications()) {
+            PathArgument childId = childMod.getIdentifier();
+            InstanceIdentifier childPath = append(path, childId);
+            Optional<ListenerRegistrationNode> childListen = getChild(listeners, childId);
+
+            Optional<StoreMetadataNode> childBefore = before.getChild(childId);
+            Optional<StoreMetadataNode> childAfter = after.getChild(childId);
+
+            switch (childMod.getModificationType()) {
+            case WRITE:
+            case DELETE:
+                one.merge(resolveAnyChangeEvent(childPath, childListen, childMod, childBefore, childBefore));
+                break;
+            case SUBTREE_MODIFIED:
+                subtree.merge(resolveSubtreeChangeEvent(childPath, childListen, childMod, childBefore.get(),
+                        childAfter.get()));
+                break;
+            }
+        }
+        DOMImmutableDataChangeEvent oneChangeEvent = one.build();
+        subtree.merge(oneChangeEvent);
+        DOMImmutableDataChangeEvent subtreeEvent = subtree.build();
+        if (listeners.isPresent()) {
+            addNotifyTask(listeners.get(), DataChangeScope.ONE, oneChangeEvent);
+            addNotifyTask(listeners.get(), DataChangeScope.SUBTREE, subtreeEvent);
+        }
+        return subtreeEvent;
+    }
+
+    private DOMImmutableDataChangeEvent resolveReplacedEvent(final InstanceIdentifier path,
+            final Optional<ListenerRegistrationNode> listeners, final NodeModification modification,
+            final StoreMetadataNode before, final StoreMetadataNode after) {
+        // FIXME Add task
+        return builder().build();
+    }
+
+    private void addNotifyTask(final ListenerRegistrationNode listenerRegistrationNode, final DataChangeScope one,
+            final DOMImmutableDataChangeEvent event) {
+
+
+
+    }
+
+    private void addNotifyTask(final Iterable<DataChangeListenerRegistration<?>> listeners,
+            final DOMImmutableDataChangeEvent event) {
+        tasks .add(new ChangeListenerNotifyTask(ImmutableSet.copyOf(listeners),event));
+    }
+
+    public static DataChangeEventResolver create() {
+        return new DataChangeEventResolver();
+    }
+
+
+
+}