Extension support - easy lookup for toOFJava

[openflowplugin.git] / extension / openflowplugin-extension-api / src / main / java / org / opendaylight / openflowplugin / extension / api / GroupingResolver.java

diff --git a/extension/openflowplugin-extension-api/src/main/java/org/opendaylight/openflowplugin/extension/api/GroupingResolver.java b/extension/openflowplugin-extension-api/src/main/java/org/opendaylight/openflowplugin/extension/api/GroupingResolver.java
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+/**
+ * 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.openflowplugin.extension.api;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.opendaylight.yangtools.yang.binding.Augmentable;
+import org.opendaylight.yangtools.yang.binding.Augmentation;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+
+/**
+ * Provides augmentation resolving upon given {@link Augmentable}.
+ * Used {@link #classes} share the same {@link Augmentable}.
+ * <br/>
+ * <b>Usage:</b> in case there is {@link Augmentable} which might contain
+ * multiple {@link Augmentation}s depending on origin. And those {@link Augmentation}s 
+ * are sharing the same grouping so that they could be processed in the same way.
+ * 
+ * @param <GROUPING>
+ * @param <T>
+ */
+public class GroupingResolver<GROUPING, T extends Augmentable<T>> {
+
+    Class<GROUPING> commonInterface;
+    Set<Class<? extends Augmentation<T>>> classes;
+
+    /**
+     * @param commonInterface
+     */
+    public GroupingResolver(Class<GROUPING> commonInterface) {
+        this.commonInterface = commonInterface;
+        classes = new HashSet<>();
+    }
+
+    /**
+     * @param cls equivalent augmentation class
+     * @return this for chaining
+     */
+    public <X extends Augmentation<T>> GroupingResolver<GROUPING, T> add(Class<X> cls) {
+        Preconditions.checkArgument(commonInterface.isAssignableFrom(cls));
+        classes.add(cls);
+        return this;
+    }
+
+    /**
+     * @param clses set of equivalent augmentation classes
+     */
+    public void setAugmentations(Set<Class<? extends Augmentation<T>>> clses) {
+        for (Class<? extends Augmentation<T>> cls : clses) {
+            Preconditions.checkArgument(commonInterface.isAssignableFrom(cls));
+        }
+        classes = clses;
+    }
+
+    /**
+     * @param data
+     * @return shared grouping
+     */
+    @SuppressWarnings("unchecked")
+    public Optional<GROUPING> getExtension(T data) {
+        for (Class<? extends Augmentation<T>> cls : classes) {
+            Augmentation<T> potential = data.getAugmentation(cls);
+            if (potential != null) {
+                return Optional.of((GROUPING) potential);
+            }
+        }
+        return Optional.absent();
+    }
+}
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