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.Cache;
14 import com.google.common.cache.CacheBuilder;
15 import java.lang.invoke.MethodHandle;
16 import java.lang.invoke.MethodHandles;
17 import java.lang.invoke.MethodHandles.Lookup;
18 import java.lang.invoke.MethodType;
19 import java.lang.reflect.Method;
20 import java.util.concurrent.ExecutionException;
21 import org.eclipse.jdt.annotation.NonNull;
22 import org.opendaylight.mdsal.binding.dom.codec.impl.ValueTypeCodec.SchemaUnawareCodec;
23 import org.opendaylight.mdsal.binding.spec.naming.BindingMapping;
24 import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
27 * Derived YANG types are just immutable value holders for simple value
28 * types, which are same as in NormalizedNode model.
30 final class EncapsulatedValueCodec extends ReflectionBasedCodec implements SchemaUnawareCodec {
32 * Use identity comparison for keys and allow classes to be GCd themselves.
34 * Since codecs can (and typically do) hold a direct or indirect strong reference to the class, they need to be also
35 * accessed via reference. Using a weak reference could be problematic, because the codec would quite often be only
36 * weakly reachable. We therefore use a soft reference, whose implementation guidance is suitable to our use case:
38 * "Virtual machine implementations are, however, encouraged to bias against clearing recently-created or
39 * recently-used soft references."
41 private static final Cache<Class<?>, EncapsulatedValueCodec> CACHE = CacheBuilder.newBuilder().weakKeys()
42 .softValues().build();
43 private static final MethodType OBJ_METHOD = MethodType.methodType(Object.class, Object.class);
45 private final MethodHandle constructor;
46 private final MethodHandle getter;
47 private final Class<?> valueType;
49 private EncapsulatedValueCodec(final Class<?> typeClz, final MethodHandle constructor, final MethodHandle getter,
50 final Class<?> valueType) {
52 this.constructor = requireNonNull(constructor);
53 this.getter = requireNonNull(getter);
54 this.valueType = requireNonNull(valueType);
57 static @NonNull EncapsulatedValueCodec of(final Class<?> typeClz, final TypeDefinition<?> typeDef)
58 throws ExecutionException {
59 return CACHE.get(typeClz, () -> {
60 final Method m = typeClz.getMethod(BindingMapping.SCALAR_TYPE_OBJECT_GET_VALUE_NAME);
61 final Lookup lookup = MethodHandles.publicLookup();
62 final MethodHandle getter = lookup.unreflect(m).asType(OBJ_METHOD);
63 final Class<?> valueType = m.getReturnType();
64 final MethodHandle constructor = lookup.findConstructor(typeClz,
65 MethodType.methodType(void.class, valueType)).asType(OBJ_METHOD);
66 return new EncapsulatedValueCodec(typeClz, constructor, getter, valueType);
71 * Quick check if a value object has a chance to deserialize using {@link #deserialize(Object)}.
73 * @param value Value to be checked
74 * @return True if the value can be encapsulated
76 boolean canAcceptObject(final Object value) {
77 return valueType.isInstance(value);
81 @SuppressWarnings("checkstyle:illegalCatch")
82 public Object deserialize(final Object input) {
84 return constructor.invokeExact(input);
85 } catch (Throwable e) {
86 Throwables.throwIfUnchecked(e);
87 throw new IllegalStateException(e);
92 @SuppressWarnings("checkstyle:illegalCatch")
93 public Object serialize(final Object input) {
95 return getter.invokeExact(input);
96 } catch (Throwable e) {
97 Throwables.throwIfUnchecked(e);
98 throw new IllegalStateException(e);