BUG-509: merge InMemoryDataTreeModification.resolveSnapshot()

This patch adds some minimal documentation and merges the two
resolveSnapshot() methods into one, making the call stack a bit easier
to understand.

Change-Id: Ib23fccdc9d2987aa255483becc63155904ebc332
Signed-off-by: Robert Varga <rovarga@cisco.com>

diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
index df3ef8b7e128b2be29eb5473bd86d056cba218d2..1540feca661aed15b7a41ffdfa40f6077e9f712d 100644 (file)
--- a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
+++ b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
@@ -88,21 +88,22 @@ final class InMemoryDataTreeModification implements DataTreeModification {
 
     @Override
     public Optional<NormalizedNode<?, ?>> readNode(final InstanceIdentifier path) {
-        Entry<InstanceIdentifier, NodeModification> modification = TreeNodeUtils.findClosestsOrFirstMatch(rootNode, path, NodeModification.IS_TERMINAL_PREDICATE);
-
-        Optional<StoreMetadataNode> result = resolveSnapshot(modification);
+        /*
+         * Walk the tree from the top, looking for the first node between root and
+         * the requested path which has been modified. If no such node exists,
+         * we use the node itself.
+         */
+        final Entry<InstanceIdentifier, NodeModification> entry = TreeNodeUtils.findClosestsOrFirstMatch(rootNode, path, NodeModification.IS_TERMINAL_PREDICATE);
+        final InstanceIdentifier key = entry.getKey();
+        final NodeModification mod = entry.getValue();
+
+        final Optional<StoreMetadataNode> result = resolveSnapshot(key, mod);
         if (result.isPresent()) {
             NormalizedNode<?, ?> data = result.get().getData();
-            return NormalizedNodeUtils.findNode(modification.getKey(), data, path);
+            return NormalizedNodeUtils.findNode(key, data, path);
+        } else {
+            return Optional.absent();
         }
-        return Optional.absent();
-    }
-
-    private Optional<StoreMetadataNode> resolveSnapshot(
-            final Entry<InstanceIdentifier, NodeModification> keyModification) {
-        InstanceIdentifier path = keyModification.getKey();
-        NodeModification modification = keyModification.getValue();
-        return resolveSnapshot(path, modification);
     }
 
     private Optional<StoreMetadataNode> resolveSnapshot(final InstanceIdentifier path,