2 * Copyright (c) 2017 Pantheon Technologies, s.r.o. 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.yangtools.yang.data.codec.gson;
10 import static com.google.common.base.Verify.verifyNotNull;
11 import static java.util.Objects.requireNonNull;
13 import com.google.common.annotations.Beta;
14 import com.google.common.base.Stopwatch;
15 import com.google.common.cache.CacheBuilder;
16 import com.google.common.cache.CacheLoader;
17 import com.google.common.cache.LoadingCache;
19 import java.util.Optional;
20 import java.util.function.BiFunction;
21 import org.eclipse.jdt.annotation.NonNull;
22 import org.opendaylight.yangtools.yang.common.QName;
23 import org.opendaylight.yangtools.yang.data.util.codec.CodecCache;
24 import org.opendaylight.yangtools.yang.data.util.codec.LazyCodecCache;
25 import org.opendaylight.yangtools.yang.data.util.codec.NoopCodecCache;
26 import org.opendaylight.yangtools.yang.data.util.codec.PrecomputedCodecCache;
27 import org.opendaylight.yangtools.yang.data.util.codec.SharedCodecCache;
28 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
29 import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
30 import org.opendaylight.yangtools.yang.model.api.stmt.DataTreeAwareEffectiveStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.DataTreeEffectiveStatement;
32 import org.opendaylight.yangtools.yang.model.api.stmt.ModuleEffectiveStatement;
33 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
34 import org.slf4j.Logger;
35 import org.slf4j.LoggerFactory;
38 * API entry point for acquiring {@link JSONCodecFactory} instances.
40 * @author Robert Varga
43 public enum JSONCodecFactorySupplier {
45 * Source of {@link JSONCodecFactory} instances compliant with RFC7951.
49 JSONCodecFactory createFactory(final EffectiveModelContext context, final CodecCache<JSONCodec<?>> cache) {
50 return new RFC7951JSONCodecFactory(context, cache);
54 * Source of {@link JSONCodecFactory} instances compliant with draft-lhotka-netmod-yang-json-02.
56 DRAFT_LHOTKA_NETMOD_YANG_JSON_02() {
58 JSONCodecFactory createFactory(final EffectiveModelContext context, final CodecCache<JSONCodec<?>> cache) {
59 return new Lhotka02JSONCodecFactory(context, cache);
63 private static final Logger LOG = LoggerFactory.getLogger(JSONCodecFactorySupplier.class);
65 private static final class EagerCacheLoader extends CacheLoader<EffectiveModelContext, JSONCodecFactory> {
66 private final BiFunction<EffectiveModelContext, CodecCache<JSONCodec<?>>, JSONCodecFactory> factorySupplier;
68 EagerCacheLoader(final BiFunction<EffectiveModelContext,
69 CodecCache<JSONCodec<?>>, JSONCodecFactory> factorySupplier) {
70 this.factorySupplier = requireNonNull(factorySupplier);
74 public JSONCodecFactory load(final EffectiveModelContext key) {
75 final Stopwatch sw = Stopwatch.createStarted();
76 final LazyCodecCache<JSONCodec<?>> lazyCache = new LazyCodecCache<>();
77 final JSONCodecFactory lazy = factorySupplier.apply(key, lazyCache);
78 final SchemaInferenceStack stack = SchemaInferenceStack.of(key);
80 int visitedLeaves = 0;
81 for (ModuleEffectiveStatement module : key.getModuleStatements().values()) {
82 visitedLeaves += codecsForChildren(lazy, stack, module);
87 final PrecomputedCodecCache<JSONCodec<?>> cache = lazyCache.toPrecomputed();
88 LOG.debug("{} leaf nodes resulted in {} simple and {} complex codecs in {}", visitedLeaves,
89 cache.simpleSize(), cache.complexSize(), sw);
90 return factorySupplier.apply(key, cache);
93 private static int codecsForChildren(final JSONCodecFactory lazy, final SchemaInferenceStack stack,
94 final DataTreeAwareEffectiveStatement<?, ?> parent) {
96 final Map<QName, DataTreeEffectiveStatement<?>> dataTree =
97 parent.getAll(DataTreeAwareEffectiveStatement.Namespace.class);
98 for (DataTreeEffectiveStatement<?> child : dataTree.values()) {
99 if (child instanceof DataTreeAwareEffectiveStatement) {
100 stack.enterDataTree(child.argument());
101 ret += codecsForChildren(lazy, stack, (DataTreeAwareEffectiveStatement<?, ?>) child);
103 } else if (child instanceof TypedDataSchemaNode) {
104 lazy.codecFor((TypedDataSchemaNode) child, stack);
113 // Weak keys to retire the entry when SchemaContext goes away
114 private final LoadingCache<EffectiveModelContext, JSONCodecFactory> precomputed;
116 // Weak keys to retire the entry when SchemaContext goes away and to force identity-based lookup
117 private final LoadingCache<EffectiveModelContext, JSONCodecFactory> shared;
119 JSONCodecFactorySupplier() {
120 precomputed = CacheBuilder.newBuilder().weakKeys().build(new EagerCacheLoader(this::createFactory));
121 shared = CacheBuilder.newBuilder().weakKeys().build(new CacheLoader<EffectiveModelContext, JSONCodecFactory>() {
123 public JSONCodecFactory load(final EffectiveModelContext key) {
124 return createFactory(key, new SharedCodecCache<>());
130 * Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
131 * return the same instance as long as the associated SchemaContext is present. Returned object can be safely
132 * used by multiple threads concurrently. If the SchemaContext instance does not have a cached instance
133 * of {@link JSONCodecFactory}, it will be completely precomputed before this method will return.
136 * Choosing this implementation is appropriate when the memory overhead of keeping a full codec tree is not as
137 * great a concern as predictable performance. When compared to the implementation returned by
138 * {@link #getShared(EffectiveModelContext)}, this implementation is expected to offer higher performance and have
139 * lower peak memory footprint when most of the SchemaContext is actually in use.
142 * For call sites which do not want to pay the CPU cost of pre-computing this implementation, but still would like
143 * to use it if is available (by being populated by some other caller), you can use
144 * {@link #getPrecomputedIfAvailable(EffectiveModelContext)}.
146 * @param context SchemaContext instance
147 * @return A sharable {@link JSONCodecFactory}
148 * @throws NullPointerException if context is null
150 public @NonNull JSONCodecFactory getPrecomputed(final @NonNull EffectiveModelContext context) {
151 return verifyNotNull(precomputed.getUnchecked(context));
155 * Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext, if it is available. This
156 * method is a non-blocking equivalent of {@link #getPrecomputed(EffectiveModelContext)} for use in code paths where
157 * the potential of having to pre-compute the implementation is not acceptable. One such scenario is when the
158 * code base wants to opportunistically take advantage of pre-computed version, but is okay with a fallback to
159 * a different implementation.
161 * @param context SchemaContext instance
162 * @return A sharable {@link JSONCodecFactory}, or absent if such an implementation is not available.
163 * @throws NullPointerException if context is null
165 public @NonNull Optional<JSONCodecFactory> getPrecomputedIfAvailable(final @NonNull EffectiveModelContext context) {
166 return Optional.ofNullable(precomputed.getIfPresent(context));
170 * Get a thread-safe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
171 * return the same instance as long as the associated EffectiveModelContext is present or the factory is not
172 * invalidated by memory pressure. Returned object can be safely used by multiple threads concurrently.
175 * Choosing this implementation is a safe default, as it will not incur prohibitive blocking, nor will it tie up
176 * memory in face of pressure.
178 * @param context SchemaContext instance
179 * @return A sharable {@link JSONCodecFactory}
180 * @throws NullPointerException if context is null
182 public @NonNull JSONCodecFactory getShared(final @NonNull EffectiveModelContext context) {
183 return verifyNotNull(shared.getUnchecked(context));
187 * Create a new thread-unsafe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method will
188 * return distinct objects every time it is invoked. Returned object may not be used from multiple threads
192 * This implementation is appropriate for one-off serialization from a single thread. It will aggressively cache
193 * codecs for reuse and will tie them up in memory until the factory is freed.
195 * @param context SchemaContext instance
196 * @return A non-sharable {@link JSONCodecFactory}
197 * @throws NullPointerException if context is null
199 public @NonNull JSONCodecFactory createLazy(final @NonNull EffectiveModelContext context) {
200 return createFactory(context, new LazyCodecCache<>());
204 * Create a simplistic, thread-safe {@link JSONCodecFactory} for a {@link EffectiveModelContext}. This method will
205 * return distinct objects every time it is invoked. Returned object may be use from multiple threads concurrently.
208 * This implementation exists mostly for completeness only, as it does not perform any caching at all and each codec
209 * is computed every time it is requested. This may be useful in extremely constrained environments, where memory
210 * footprint is more critical than performance.
212 * @param context SchemaContext instance
213 * @return A non-sharable {@link JSONCodecFactory}
214 * @throws NullPointerException if context is null.
216 public @NonNull JSONCodecFactory createSimple(final @NonNull EffectiveModelContext context) {
217 return createFactory(context, NoopCodecCache.getInstance());
220 abstract @NonNull JSONCodecFactory createFactory(EffectiveModelContext context, CodecCache<JSONCodec<?>> cache);