2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.binding.dom.codec.impl;
10 import static java.util.Objects.requireNonNull;
12 import com.google.common.base.Throwables;
13 import com.google.common.cache.CacheBuilder;
14 import com.google.common.cache.CacheLoader;
15 import com.google.common.cache.LoadingCache;
16 import java.lang.invoke.MethodHandle;
17 import java.lang.invoke.MethodHandles;
18 import java.lang.invoke.MethodHandles.Lookup;
19 import java.lang.invoke.MethodType;
20 import java.lang.reflect.Method;
21 import java.util.concurrent.ExecutionException;
22 import org.eclipse.jdt.annotation.NonNull;
23 import org.opendaylight.mdsal.binding.spec.naming.BindingMapping;
26 * Derived YANG types are just immutable value holders for simple value
27 * types, which are same as in NormalizedNode model.
29 final class EncapsulatedValueCodec extends SchemaUnawareCodec {
30 private static final MethodType OBJ_METHOD = MethodType.methodType(Object.class, Object.class);
33 * Use identity comparison for keys and allow classes to be GCd themselves.
35 * Since codecs can (and typically do) hold a direct or indirect strong reference to the class, they need to be also
36 * accessed via reference. Using a weak reference could be problematic, because the codec would quite often be only
37 * weakly reachable. We therefore use a soft reference, whose implementation guidance is suitable to our use case:
39 * "Virtual machine implementations are, however, encouraged to bias against clearing recently-created or
40 * recently-used soft references."
42 private static final LoadingCache<Class<?>, EncapsulatedValueCodec> CACHE = CacheBuilder.newBuilder().weakKeys()
43 .softValues().build(new CacheLoader<>() {
45 public EncapsulatedValueCodec load(final Class<?> key) throws ReflectiveOperationException {
46 final Method m = key.getMethod(BindingMapping.SCALAR_TYPE_OBJECT_GET_VALUE_NAME);
47 final Lookup lookup = MethodHandles.publicLookup();
48 final MethodHandle getter = lookup.unreflect(m).asType(OBJ_METHOD);
49 final Class<?> valueType = m.getReturnType();
50 final MethodHandle constructor = lookup.findConstructor(key,
51 MethodType.methodType(void.class, valueType)).asType(OBJ_METHOD);
52 return new EncapsulatedValueCodec(constructor, getter, valueType);
56 private final MethodHandle constructor;
57 private final MethodHandle getter;
58 private final Class<?> valueType;
60 private EncapsulatedValueCodec(final MethodHandle constructor, final MethodHandle getter,
61 final Class<?> valueType) {
62 this.constructor = requireNonNull(constructor);
63 this.getter = requireNonNull(getter);
64 this.valueType = requireNonNull(valueType);
67 static @NonNull EncapsulatedValueCodec of(final Class<?> typeClz) throws ExecutionException {
68 // FIXME: require base class to be ScalarTypeObject
69 return CACHE.get(typeClz);
73 * Quick check if a value object has a chance to deserialize using {@link #deserialize(Object)}.
75 * @param value Value to be checked
76 * @return True if the value can be encapsulated
78 boolean canAcceptObject(final Object value) {
79 return valueType.isInstance(value);
83 @SuppressWarnings("checkstyle:illegalCatch")
84 protected Object deserializeImpl(final Object input) {
86 return constructor.invokeExact(input);
87 } catch (Throwable e) {
88 Throwables.throwIfUnchecked(e);
89 throw new IllegalStateException(e);
94 @SuppressWarnings("checkstyle:illegalCatch")
95 protected Object serializeImpl(final Object input) {
97 return getter.invokeExact(input);
98 } catch (Throwable e) {
99 Throwables.throwIfUnchecked(e);
100 throw new IllegalStateException(e);