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.yangtools.yang.data.codec.gson;
10 import com.google.common.annotations.Beta;
11 import com.google.common.base.Optional;
12 import com.google.common.base.Stopwatch;
13 import com.google.common.cache.CacheBuilder;
14 import com.google.common.cache.CacheLoader;
15 import com.google.common.cache.LoadingCache;
16 import java.util.List;
17 import org.opendaylight.yangtools.yang.common.QNameModule;
18 import org.opendaylight.yangtools.yang.data.impl.codec.AbstractIntegerStringCodec;
19 import org.opendaylight.yangtools.yang.data.impl.codec.BinaryStringCodec;
20 import org.opendaylight.yangtools.yang.data.impl.codec.BitsStringCodec;
21 import org.opendaylight.yangtools.yang.data.impl.codec.BooleanStringCodec;
22 import org.opendaylight.yangtools.yang.data.impl.codec.DecimalStringCodec;
23 import org.opendaylight.yangtools.yang.data.impl.codec.EnumStringCodec;
24 import org.opendaylight.yangtools.yang.data.impl.codec.StringStringCodec;
25 import org.opendaylight.yangtools.yang.data.util.codec.AbstractCodecFactory;
26 import org.opendaylight.yangtools.yang.data.util.codec.CodecCache;
27 import org.opendaylight.yangtools.yang.data.util.codec.LazyCodecCache;
28 import org.opendaylight.yangtools.yang.data.util.codec.NoopCodecCache;
29 import org.opendaylight.yangtools.yang.data.util.codec.PrecomputedCodecCache;
30 import org.opendaylight.yangtools.yang.data.util.codec.SharedCodecCache;
31 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
32 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
33 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
34 import org.opendaylight.yangtools.yang.model.api.TypedSchemaNode;
35 import org.opendaylight.yangtools.yang.model.api.type.BinaryTypeDefinition;
36 import org.opendaylight.yangtools.yang.model.api.type.BitsTypeDefinition;
37 import org.opendaylight.yangtools.yang.model.api.type.BooleanTypeDefinition;
38 import org.opendaylight.yangtools.yang.model.api.type.DecimalTypeDefinition;
39 import org.opendaylight.yangtools.yang.model.api.type.EmptyTypeDefinition;
40 import org.opendaylight.yangtools.yang.model.api.type.EnumTypeDefinition;
41 import org.opendaylight.yangtools.yang.model.api.type.IdentityrefTypeDefinition;
42 import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
43 import org.opendaylight.yangtools.yang.model.api.type.IntegerTypeDefinition;
44 import org.opendaylight.yangtools.yang.model.api.type.StringTypeDefinition;
45 import org.opendaylight.yangtools.yang.model.api.type.UnionTypeDefinition;
46 import org.opendaylight.yangtools.yang.model.api.type.UnknownTypeDefinition;
47 import org.opendaylight.yangtools.yang.model.api.type.UnsignedIntegerTypeDefinition;
48 import org.slf4j.Logger;
49 import org.slf4j.LoggerFactory;
52 * Factory for creating JSON equivalents of codecs. Each instance of this object is bound to
53 * a particular {@link SchemaContext}, but can be reused by multiple {@link JSONNormalizedNodeStreamWriter}s.
55 * There are multiple implementations available, each with distinct thread-safety, CPU/memory trade-offs and reuse
56 * characteristics. See {@link #getShared(SchemaContext)}, {@link #getPrecomputed(SchemaContext)},
57 * {@link #createLazy(SchemaContext)} and {@link #createSimple(SchemaContext)} for details.
60 public final class JSONCodecFactory extends AbstractCodecFactory<JSONCodec<?>> {
61 private static final class EagerCacheLoader extends CacheLoader<SchemaContext, JSONCodecFactory> {
63 public JSONCodecFactory load(final SchemaContext key) {
64 final Stopwatch sw = Stopwatch.createStarted();
65 final LazyCodecCache<JSONCodec<?>> lazyCache = new LazyCodecCache<>();
66 final JSONCodecFactory lazy = new JSONCodecFactory(key, lazyCache);
67 final int visitedLeaves = requestCodecsForChildren(lazy, key);
70 final PrecomputedCodecCache<JSONCodec<?>> cache = lazyCache.toPrecomputed();
71 LOG.debug("{} leaf nodes resulted in {} simple and {} complex codecs in {}", visitedLeaves,
72 cache.simpleSize(), cache.complexSize(), sw);
73 return new JSONCodecFactory(key, cache);
76 private static int requestCodecsForChildren(final JSONCodecFactory lazy, final DataNodeContainer parent) {
78 for (DataSchemaNode child : parent.getChildNodes()) {
79 if (child instanceof TypedSchemaNode) {
80 lazy.codecFor((TypedSchemaNode) child);
82 } else if (child instanceof DataNodeContainer) {
83 ret += requestCodecsForChildren(lazy, (DataNodeContainer) child);
91 private static final Logger LOG = LoggerFactory.getLogger(JSONCodecFactory.class);
93 // Weak keys to retire the entry when SchemaContext goes away
94 private static final LoadingCache<SchemaContext, JSONCodecFactory> PRECOMPUTED = CacheBuilder.newBuilder()
95 .weakKeys().build(new EagerCacheLoader());
97 // Weak keys to retire the entry when SchemaContext goes away and to force identity-based lookup
98 private static final LoadingCache<SchemaContext, JSONCodecFactory> SHARED = CacheBuilder.newBuilder()
99 .weakKeys().build(new CacheLoader<SchemaContext, JSONCodecFactory>() {
101 public JSONCodecFactory load(final SchemaContext key) {
102 return new JSONCodecFactory(key, new SharedCodecCache<>());
106 private final JSONCodec<?> iidCodec;
108 JSONCodecFactory(final SchemaContext context, final CodecCache<JSONCodec<?>> cache) {
109 super(context, cache);
110 iidCodec = new JSONStringInstanceIdentifierCodec(context, this);
114 * Instantiate a new codec factory attached to a particular context.
116 * @param context SchemaContext to which the factory should be bound
117 * @return A codec factory instance.
119 * @deprecated Use {@link #getShared(SchemaContext)} instead.
122 public static JSONCodecFactory create(final SchemaContext context) {
123 return getShared(context);
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.
132 * Choosing this implementation is appropriate when the memory overhead of keeping a full codec tree is not as
133 * great a concern as predictable performance. When compared to the implementation returned by
134 * {@link #getShared(SchemaContext)}, this implementation is expected to offer higher performance and have lower
135 * peak memory footprint when most of the SchemaContext is actually in use.
137 * For call sites which do not want to pay the CPU cost of pre-computing this implementation, but still would like
138 * to use it if is available (by being populated by some other caller), you can use
139 * {@link #getPrecomputedIfAvailable(SchemaContext)}.
141 * @param context SchemaContext instance
142 * @return A sharable {@link JSONCodecFactory}
143 * @throws NullPointerException if context is null
145 public static JSONCodecFactory getPrecomputed(final SchemaContext context) {
146 return PRECOMPUTED.getUnchecked(context);
150 * Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext, if it is available. This
151 * method is a non-blocking equivalent of {@link #getPrecomputed(SchemaContext)} for use in code paths where
152 * the potential of having to pre-compute the implementation is not acceptable. One such scenario is when the
153 * code base wants to opportunistically take advantage of pre-computed version, but is okay with a fallback to
154 * a different implementation.
156 * @param context SchemaContext instance
157 * @return A sharable {@link JSONCodecFactory}, or absent if such an implementation is not available.
158 * @throws NullPointerException if context is null
160 public static Optional<JSONCodecFactory> getPrecomputedIfAvailable(final SchemaContext context) {
161 return Optional.fromNullable(PRECOMPUTED.getIfPresent(context));
165 * Get a thread-safe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
166 * return the same instance as long as the associated SchemaContext is present or the factory is not invalidated
167 * by memory pressure. Returned object can be safely used by multiple threads concurrently.
169 * Choosing this implementation is a safe default, as it will not incur prohibitive blocking, nor will it tie up
170 * memory in face of pressure.
172 * @param context SchemaContext instance
173 * @return A sharable {@link JSONCodecFactory}
174 * @throws NullPointerException if context is null
176 public static JSONCodecFactory getShared(final SchemaContext context) {
177 return SHARED.getUnchecked(context);
181 * Create a new thread-unsafe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method will
182 * return distinct objects every time it is invoked. Returned object may not be used from multiple threads
185 * This implementation is appropriate for one-off serialization from a single thread. It will aggressively cache
186 * codecs for reuse and will tie them up in memory until the factory is freed.
188 * @param context SchemaContext instance
189 * @return A non-sharable {@link JSONCodecFactory}
190 * @throws NullPointerException if context is null
192 public static JSONCodecFactory createLazy(final SchemaContext context) {
193 return new JSONCodecFactory(context, new LazyCodecCache<>());
197 * Create a simplistic, thread-safe {@link JSONCodecFactory} for a {@link SchemaContext}. This method will return
198 * distinct objects every time it is invoked. Returned object may be use from multiple threads concurrently.
200 * This implementation exists mostly for completeness only, as it does not perform any caching at all and each codec
201 * is computed every time it is requested. This may be useful in extremely constrained environments, where memory
202 * footprint is more critical than performance.
204 * @param context SchemaContext instance
205 * @return A non-sharable {@link JSONCodecFactory}
206 * @throws NullPointerException if context is null.
208 public static JSONCodecFactory createSimple(final SchemaContext context) {
209 return new JSONCodecFactory(context, NoopCodecCache.getInstance());
213 protected JSONCodec<?> binaryCodec(final BinaryTypeDefinition type) {
214 return new QuotedJSONCodec<>(BinaryStringCodec.from(type));
218 protected JSONCodec<?> booleanCodec(final BooleanTypeDefinition type) {
219 return new BooleanJSONCodec(BooleanStringCodec.from(type));
223 protected JSONCodec<?> bitsCodec(final BitsTypeDefinition type) {
224 return new QuotedJSONCodec<>(BitsStringCodec.from(type));
228 protected JSONCodec<?> decimalCodec(final DecimalTypeDefinition type) {
229 return new NumberJSONCodec<>(DecimalStringCodec.from(type));
233 protected JSONCodec<?> emptyCodec(final EmptyTypeDefinition type) {
234 return EmptyJSONCodec.INSTANCE;
238 protected JSONCodec<?> enumCodec(final EnumTypeDefinition type) {
239 return new QuotedJSONCodec<>(EnumStringCodec.from(type));
243 protected JSONCodec<?> identityRefCodec(final IdentityrefTypeDefinition type, final QNameModule module) {
244 return new IdentityrefJSONCodec(getSchemaContext(), module);
248 protected JSONCodec<?> instanceIdentifierCodec(final InstanceIdentifierTypeDefinition type) {
249 // FIXME: there really are two favors, as 'require-instance true' needs to be validated. In order to deal
250 // with that, though, we need access to the current data store.
255 protected JSONCodec<?> intCodec(final IntegerTypeDefinition type) {
256 return new NumberJSONCodec<>(AbstractIntegerStringCodec.from(type));
260 protected JSONCodec<?> stringCodec(final StringTypeDefinition type) {
261 return new QuotedJSONCodec<>(StringStringCodec.from(type));
265 protected JSONCodec<?> uintCodec(final UnsignedIntegerTypeDefinition type) {
266 return new NumberJSONCodec<>(AbstractIntegerStringCodec.from(type));
270 protected JSONCodec<?> unionCodec(final UnionTypeDefinition type, final List<JSONCodec<?>> codecs) {
271 return UnionJSONCodec.create(type, codecs);
275 protected JSONCodec<?> unknownCodec(final UnknownTypeDefinition type) {
276 return NullJSONCodec.INSTANCE;