Separate out mdsal-binding-dom-codec-spi

[mdsal.git] / binding / mdsal-binding-dom-codec-spi / src / main / java / org / opendaylight / mdsal / binding / dom / codec / spi / AbstractBindingLazyContainerNode.java

diff --git a/binding/mdsal-binding-dom-codec-spi/src/main/java/org/opendaylight/mdsal/binding/dom/codec/spi/AbstractBindingLazyContainerNode.java b/binding/mdsal-binding-dom-codec-spi/src/main/java/org/opendaylight/mdsal/binding/dom/codec/spi/AbstractBindingLazyContainerNode.java
new file mode 100644 (file)
index 0000000..3ced7d8
--- /dev/null
+++ b/binding/mdsal-binding-dom-codec-spi/src/main/java/org/opendaylight/mdsal/binding/dom/codec/spi/AbstractBindingLazyContainerNode.java
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2018 Pantheon Technologies, s.r.o. 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.mdsal.binding.dom.codec.spi;
+
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ForwardingObject;
+import java.util.Collection;
+import java.util.Optional;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
+import org.opendaylight.mdsal.binding.dom.codec.api.BindingLazyContainerNode;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
+import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
+import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
+
+/**
+ * A {@link ContainerNode} backed by a binding {@link DataObject}, with lazy instantiation of the ContainerNode view.
+ * This class is thread-safe.
+ *
+ * @param <T> Binding DataObject type
+ * @author Robert Varga
+ */
+@Beta
+public abstract class AbstractBindingLazyContainerNode<T extends DataObject, C> extends ForwardingObject
+        implements BindingLazyContainerNode<T> {
+    private final @NonNull NodeIdentifier identifier;
+    private final @NonNull T bindingData;
+
+    private volatile @Nullable ContainerNode delegate;
+    @GuardedBy("this")
+    private @Nullable C context;
+
+    protected AbstractBindingLazyContainerNode(final @NonNull NodeIdentifier identifier, final @NonNull T bindingData,
+            final C context) {
+        this.identifier = requireNonNull(identifier);
+        this.bindingData = requireNonNull(bindingData);
+        this.context = context;
+    }
+
+    @Override
+    public final @NonNull T getDataObject() {
+        return bindingData;
+    }
+
+    @Override
+    public final @NonNull NodeIdentifier getIdentifier() {
+        return identifier;
+    }
+
+    @Override
+    public final QName getNodeType() {
+        return identifier.getNodeType();
+    }
+
+    @Override
+    public final ContainerNode getDelegate() {
+        return delegate();
+    }
+
+    @Override
+    public Collection<DataContainerChild<? extends PathArgument, ?>> getValue() {
+        return delegate().getValue();
+    }
+
+    @Override
+    public Optional<DataContainerChild<? extends PathArgument, ?>> getChild(final PathArgument child) {
+        return delegate().getChild(child);
+    }
+
+    @Override
+    public int hashCode() {
+        return delegate().hashCode();
+    }
+
+    @Override
+    public boolean equals(final @Nullable Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof ContainerNode)) {
+            return false;
+        }
+        final ContainerNode other = (ContainerNode) obj;
+        return delegate().equals(other);
+    }
+
+    @Override
+    protected final @NonNull ContainerNode delegate() {
+        ContainerNode local = delegate;
+        if (local == null) {
+            synchronized (this) {
+                local = delegate;
+                if (local == null) {
+                    local = delegate = requireNonNull(computeContainerNode(context));
+                    context = null;
+                }
+            }
+        }
+
+        return local;
+    }
+
+    @GuardedBy("this")
+    protected abstract @NonNull ContainerNode computeContainerNode(C context);
+}