+/*
+ * Copyright (c) 2015 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.controller.md.sal.binding.impl;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import java.lang.reflect.Method;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.binding.annotations.RoutingContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+abstract class ContextReferenceExtractor {
+
+ private static final Logger LOG = LoggerFactory.getLogger(ContextReferenceExtractor.class);
+ private static final ContextReferenceExtractor NULL_EXTRACTOR = new ContextReferenceExtractor() {
+
+ @Override
+ InstanceIdentifier<?> extract(final DataObject obj) {
+ return null;
+ }
+ };
+
+
+ private static final LoadingCache<Class<?>, ContextReferenceExtractor> EXTRACTORS = CacheBuilder.newBuilder()
+ .weakKeys().build(new CacheLoader<Class<?>, ContextReferenceExtractor>() {
+
+ @Override
+ public ContextReferenceExtractor load(final Class<?> key) throws Exception {
+ return create(key);
+ }
+ });
+
+
+ private static final String GET_VALUE_NAME = "getValue";
+
+ static ContextReferenceExtractor from(final Class<?> obj) {
+ return EXTRACTORS.getUnchecked(obj);
+ }
+
+ /**
+ * Extract context-reference (Instance Identifier) from
+ * Binding DataObject.
+ *
+ * @param obj DataObject from which context reference
+ * should be extracted.
+ *
+ * @return Instance Identifier representing context reference
+ * or null, if data object does not contain context reference.
+ */
+ abstract @Nullable InstanceIdentifier<?> extract(DataObject obj);
+
+ private static @Nonnull ContextReferenceExtractor create(final Class<?> key) {
+ final Method contextGetter = getContextGetter(key);
+ if (contextGetter == null) {
+ return NULL_EXTRACTOR;
+ }
+ final Class<?> returnType = contextGetter.getReturnType();
+ try {
+ if (InstanceIdentifier.class.isAssignableFrom(returnType)) {
+ return DirectGetterRouteContextExtractor.create(contextGetter);
+ }
+ final Method getValueMethod = findGetValueMethod(returnType,InstanceIdentifier.class);
+ if (getValueMethod != null) {
+ return GetValueRouteContextExtractor.create(contextGetter, getValueMethod);
+ } else {
+ LOG.warn("Class {} can not be used to determine context, falling back to NULL_EXTRACTOR.",returnType);
+ }
+ } catch (final IllegalAccessException e) {
+ LOG.warn("Class {} does not conform to Binding Specification v1. Falling back to NULL_EXTRACTOR", e);
+ }
+ return NULL_EXTRACTOR;
+ }
+
+ private static @Nullable Method findGetValueMethod(final Class<?> type, final Class<?> returnType) {
+ try {
+ final Method method = type.getMethod(GET_VALUE_NAME);
+ if(returnType.equals(method.getReturnType())) {
+ return method;
+ }
+ } catch (final NoSuchMethodException e) {
+ LOG.warn("Value class {} does not comform to Binding Specification v1.", type, e);
+ }
+ return null;
+ }
+
+ private static Method getContextGetter(final Class<?> key) {
+ for (final Method method : key.getMethods()) {
+ if (method.getAnnotation(RoutingContext.class) != null) {
+ return method;
+ }
+ }
+ return null;
+ }
+
+
+
+}