Always use lazy leaf nodes

[yangtools.git] / yang / yang-data-impl / src / main / java / org / opendaylight / yangtools / yang / data / impl / schema / nodes / AbstractImmutableDataContainerNode.java

diff --git a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/AbstractImmutableDataContainerNode.java b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/AbstractImmutableDataContainerNode.java
index 01bfe32b2811d9afaf93040f6c8c112af899bdf7..6b5e0d7e5124eb8ee661fa9f8119a624252f7daf 100644 (file)
--- a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/AbstractImmutableDataContainerNode.java
+++ b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/AbstractImmutableDataContainerNode.java
@@ -7,60 +7,38 @@
  */
 package org.opendaylight.yangtools.yang.data.impl.schema.nodes;
 
-import com.google.common.base.Optional;
-
-import java.util.Collections;
+import java.util.Collection;
 import java.util.Map;
-
-import org.opendaylight.yangtools.concepts.Immutable;
+import java.util.Optional;
+import org.opendaylight.yangtools.util.ImmutableOffsetMap;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerNode;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
-public abstract class AbstractImmutableDataContainerNode<K extends PathArgument> extends AbstractImmutableNormalizedNode<K, Iterable<DataContainerChild<? extends PathArgument, ?>>> implements Immutable, DataContainerNode<K> {
-    private static final Logger LOG = LoggerFactory.getLogger(AbstractImmutableDataContainerNode.class);
-    private final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> children;
+public abstract class AbstractImmutableDataContainerNode<K extends PathArgument>
+        extends AbstractImmutableNormalizedNode<K, Collection<DataContainerChild<? extends PathArgument, ?>>>
+        implements DataContainerNode<K> {
+    private final Map<PathArgument, Object> children;
 
-    public AbstractImmutableDataContainerNode(
-            final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> children, final K nodeIdentifier) {
+    protected AbstractImmutableDataContainerNode(final Map<PathArgument, Object> children, final K nodeIdentifier) {
         super(nodeIdentifier);
 
-        /*
-         * There is a code path where AbstractImmutableDataContainerNodeBuilder can reflect
-         * the collection acquired via getChildren() back to us. This is typically the case
-         * in the datastore where transactions cancel each other out, leaving an unmodified
-         * node. In that case we want to skip wrapping the map again (and again and again).
-         *
-         * In a perfect world, Collection.unmodifiableMap() would be doing the instanceof
-         * check which would stop the proliferation. Unfortunately this not the case and the
-         * 'unmodifiable' trait is not exposed by anything we can query. Furthermore the API
-         * contract there is sufficiently vague so an implementation may actually return a
-         * different implementation based on input map -- for example
-         * Collections.unmodifiableMap(Collections.emptyMap()) returning the same thing as
-         * Collections.emptyMap().
-         *
-         * This means that we have to perform the instantiation here (as opposed to once at
-         * class load time) and then compare the classes.
-         */
-        final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> pub = Collections.unmodifiableMap(children);
-        if (children.getClass().equals(pub.getClass())) {
-            LOG.trace("Reusing already-unmodifiable children {}", children);
-            this.children = children;
-        } else {
-            this.children = pub;
-        }
+        this.children = ImmutableOffsetMap.unorderedCopyOf(children);
     }
 
     @Override
     public final Optional<DataContainerChild<? extends PathArgument, ?>> getChild(final PathArgument child) {
-        return Optional.<DataContainerChild<? extends PathArgument, ?>> fromNullable(children.get(child));
+        return Optional.ofNullable(LazyLeafOperations.getChild(children, child));
+    }
+
+    @Override
+    public final Collection<DataContainerChild<? extends PathArgument, ?>> getValue() {
+        return new LazyValues(children);
     }
 
     @Override
-    public final Iterable<DataContainerChild<? extends PathArgument, ?>> getValue() {
-        return children.values();
+    public final int size() {
+        return children.size();
     }
 
     @Override
@@ -68,16 +46,22 @@ public abstract class AbstractImmutableDataContainerNode<K extends PathArgument>
         return children.hashCode();
     }
 
-    public final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> getChildren() {
+    /**
+     * DO NOT USE THIS METHOD.
+     *
+     * <p>
+     * This is an implementation-internal API and no outside users should use it. If you do, you are asking for trouble,
+     * as the returned object is not guaranteed to conform to java.util.Map interface, nor is its contents well-defined.
+     *
+     * @return An unmodifiable view if this node's children.
+     */
+    public final Map<PathArgument, Object> getChildren() {
         return children;
     }
 
     @Override
     protected boolean valueEquals(final AbstractImmutableNormalizedNode<?, ?> other) {
-        if (!(other instanceof AbstractImmutableDataContainerNode<?>)) {
-            return false;
-        }
-
-        return children.equals(((AbstractImmutableDataContainerNode<?>)other).children);
+        return other instanceof AbstractImmutableDataContainerNode<?> && children.equals(
+                ((AbstractImmutableDataContainerNode<?>) other).children);
     }
 }