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;
18 import java.util.Optional;
19 import java.util.function.BiFunction;
20 import org.eclipse.jdt.annotation.NonNull;
21 import org.opendaylight.yangtools.yang.data.util.codec.CodecCache;
22 import org.opendaylight.yangtools.yang.data.util.codec.LazyCodecCache;
23 import org.opendaylight.yangtools.yang.data.util.codec.NoopCodecCache;
24 import org.opendaylight.yangtools.yang.data.util.codec.PrecomputedCodecCache;
25 import org.opendaylight.yangtools.yang.data.util.codec.SharedCodecCache;
26 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
27 import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
28 import org.opendaylight.yangtools.yang.model.api.stmt.DataTreeAwareEffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.stmt.DataTreeAwareEffectiveStatement.Namespace;
30 import org.opendaylight.yangtools.yang.model.api.stmt.ModuleEffectiveStatement;
31 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
32 import org.slf4j.Logger;
33 import org.slf4j.LoggerFactory;
36 * API entry point for acquiring {@link JSONCodecFactory} instances.
38 * @author Robert Varga
41 public enum JSONCodecFactorySupplier {
43 * Source of {@link JSONCodecFactory} instances compliant with RFC7951.
47 JSONCodecFactory createFactory(final EffectiveModelContext context, final CodecCache<JSONCodec<?>> cache) {
48 return new RFC7951JSONCodecFactory(context, cache);
52 * Source of {@link JSONCodecFactory} instances compliant with draft-lhotka-netmod-yang-json-02.
54 DRAFT_LHOTKA_NETMOD_YANG_JSON_02() {
56 JSONCodecFactory createFactory(final EffectiveModelContext context, final CodecCache<JSONCodec<?>> cache) {
57 return new Lhotka02JSONCodecFactory(context, cache);
61 private static final Logger LOG = LoggerFactory.getLogger(JSONCodecFactorySupplier.class);
63 private static final class EagerCacheLoader extends CacheLoader<EffectiveModelContext, JSONCodecFactory> {
64 private final BiFunction<EffectiveModelContext, CodecCache<JSONCodec<?>>, JSONCodecFactory> factorySupplier;
66 EagerCacheLoader(final BiFunction<EffectiveModelContext,
67 CodecCache<JSONCodec<?>>, JSONCodecFactory> factorySupplier) {
68 this.factorySupplier = requireNonNull(factorySupplier);
72 public JSONCodecFactory load(final EffectiveModelContext key) {
73 final Stopwatch sw = Stopwatch.createStarted();
74 final LazyCodecCache<JSONCodec<?>> lazyCache = new LazyCodecCache<>();
75 final JSONCodecFactory lazy = factorySupplier.apply(key, lazyCache);
76 final SchemaInferenceStack stack = SchemaInferenceStack.of(key);
78 int visitedLeaves = 0;
79 for (ModuleEffectiveStatement module : key.getModuleStatements().values()) {
80 visitedLeaves += codecsForChildren(lazy, stack, module);
85 final PrecomputedCodecCache<JSONCodec<?>> cache = lazyCache.toPrecomputed();
86 LOG.debug("{} leaf nodes resulted in {} simple and {} complex codecs in {}", visitedLeaves,
87 cache.simpleSize(), cache.complexSize(), sw);
88 return factorySupplier.apply(key, cache);
91 private static int codecsForChildren(final JSONCodecFactory lazy, final SchemaInferenceStack stack,
92 final DataTreeAwareEffectiveStatement<?, ?> parent) {
94 for (var entry : parent.getAll(Namespace.class).entrySet()) {
95 final var child = entry.getValue();
96 if (child instanceof DataTreeAwareEffectiveStatement) {
97 stack.enterDataTree(entry.getKey());
98 ret += codecsForChildren(lazy, stack, (DataTreeAwareEffectiveStatement<?, ?>) child);
100 } else if (child instanceof TypedDataSchemaNode) {
101 lazy.codecFor((TypedDataSchemaNode) child, stack);
110 // Weak keys to retire the entry when SchemaContext goes away
111 private final LoadingCache<EffectiveModelContext, JSONCodecFactory> precomputed;
113 // Weak keys to retire the entry when SchemaContext goes away and to force identity-based lookup
114 private final LoadingCache<EffectiveModelContext, JSONCodecFactory> shared;
116 JSONCodecFactorySupplier() {
117 precomputed = CacheBuilder.newBuilder().weakKeys().build(new EagerCacheLoader(this::createFactory));
118 shared = CacheBuilder.newBuilder().weakKeys().build(new CacheLoader<EffectiveModelContext, JSONCodecFactory>() {
120 public JSONCodecFactory load(final EffectiveModelContext key) {
121 return createFactory(key, new SharedCodecCache<>());
127 * Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
128 * return the same instance as long as the associated SchemaContext is present. Returned object can be safely
129 * used by multiple threads concurrently. If the SchemaContext instance does not have a cached instance
130 * of {@link JSONCodecFactory}, it will be completely precomputed before this method will return.
133 * Choosing this implementation is appropriate when the memory overhead of keeping a full codec tree is not as
134 * great a concern as predictable performance. When compared to the implementation returned by
135 * {@link #getShared(EffectiveModelContext)}, this implementation is expected to offer higher performance and have
136 * lower peak memory footprint when most of the SchemaContext is actually in use.
139 * For call sites which do not want to pay the CPU cost of pre-computing this implementation, but still would like
140 * to use it if is available (by being populated by some other caller), you can use
141 * {@link #getPrecomputedIfAvailable(EffectiveModelContext)}.
143 * @param context SchemaContext instance
144 * @return A sharable {@link JSONCodecFactory}
145 * @throws NullPointerException if context is null
147 public @NonNull JSONCodecFactory getPrecomputed(final @NonNull EffectiveModelContext context) {
148 return verifyNotNull(precomputed.getUnchecked(context));
152 * Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext, if it is available. This
153 * method is a non-blocking equivalent of {@link #getPrecomputed(EffectiveModelContext)} for use in code paths where
154 * the potential of having to pre-compute the implementation is not acceptable. One such scenario is when the
155 * code base wants to opportunistically take advantage of pre-computed version, but is okay with a fallback to
156 * a different implementation.
158 * @param context SchemaContext instance
159 * @return A sharable {@link JSONCodecFactory}, or absent if such an implementation is not available.
160 * @throws NullPointerException if context is null
162 public @NonNull Optional<JSONCodecFactory> getPrecomputedIfAvailable(final @NonNull EffectiveModelContext context) {
163 return Optional.ofNullable(precomputed.getIfPresent(context));
167 * Get a thread-safe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
168 * return the same instance as long as the associated EffectiveModelContext is present or the factory is not
169 * invalidated by memory pressure. Returned object can be safely used by multiple threads concurrently.
172 * Choosing this implementation is a safe default, as it will not incur prohibitive blocking, nor will it tie up
173 * memory in face of pressure.
175 * @param context SchemaContext instance
176 * @return A sharable {@link JSONCodecFactory}
177 * @throws NullPointerException if context is null
179 public @NonNull JSONCodecFactory getShared(final @NonNull EffectiveModelContext context) {
180 return verifyNotNull(shared.getUnchecked(context));
184 * Create a new thread-unsafe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method will
185 * return distinct objects every time it is invoked. Returned object may not be used from multiple threads
189 * This implementation is appropriate for one-off serialization from a single thread. It will aggressively cache
190 * codecs for reuse and will tie them up in memory until the factory is freed.
192 * @param context SchemaContext instance
193 * @return A non-sharable {@link JSONCodecFactory}
194 * @throws NullPointerException if context is null
196 public @NonNull JSONCodecFactory createLazy(final @NonNull EffectiveModelContext context) {
197 return createFactory(context, new LazyCodecCache<>());
201 * Create a simplistic, thread-safe {@link JSONCodecFactory} for a {@link EffectiveModelContext}. This method will
202 * return distinct objects every time it is invoked. Returned object may be use from multiple threads concurrently.
205 * This implementation exists mostly for completeness only, as it does not perform any caching at all and each codec
206 * is computed every time it is requested. This may be useful in extremely constrained environments, where memory
207 * footprint is more critical than performance.
209 * @param context SchemaContext instance
210 * @return A non-sharable {@link JSONCodecFactory}
211 * @throws NullPointerException if context is null.
213 public @NonNull JSONCodecFactory createSimple(final @NonNull EffectiveModelContext context) {
214 return createFactory(context, NoopCodecCache.getInstance());
217 abstract @NonNull JSONCodecFactory createFactory(EffectiveModelContext context, CodecCache<JSONCodec<?>> cache);