/*
* Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.data.codec.gson;
import com.google.common.annotations.Beta;
import com.google.common.base.Optional;
import com.google.common.base.Stopwatch;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import java.util.List;
import org.opendaylight.yangtools.yang.common.QNameModule;
import org.opendaylight.yangtools.yang.data.impl.codec.AbstractIntegerStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.BinaryStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.BitsStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.BooleanStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.DecimalStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.EnumStringCodec;
import org.opendaylight.yangtools.yang.data.impl.codec.StringStringCodec;
import org.opendaylight.yangtools.yang.data.util.codec.AbstractCodecFactory;
import org.opendaylight.yangtools.yang.data.util.codec.CodecCache;
import org.opendaylight.yangtools.yang.data.util.codec.LazyCodecCache;
import org.opendaylight.yangtools.yang.data.util.codec.NoopCodecCache;
import org.opendaylight.yangtools.yang.data.util.codec.PrecomputedCodecCache;
import org.opendaylight.yangtools.yang.data.util.codec.SharedCodecCache;
import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.api.TypedSchemaNode;
import org.opendaylight.yangtools.yang.model.api.type.BinaryTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BitsTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BooleanTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.DecimalTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EmptyTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EnumTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.IdentityrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.IntegerTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.StringTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.UnionTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.UnknownTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.UnsignedIntegerTypeDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Factory for creating JSON equivalents of codecs. Each instance of this object is bound to
* a particular {@link SchemaContext}, but can be reused by multiple {@link JSONNormalizedNodeStreamWriter}s.
*
* There are multiple implementations available, each with distinct thread-safety, CPU/memory trade-offs and reuse
* characteristics. See {@link #getShared(SchemaContext)}, {@link #getPrecomputed(SchemaContext)},
* {@link #createLazy(SchemaContext)} and {@link #createSimple(SchemaContext)} for details.
*/
@Beta
public final class JSONCodecFactory extends AbstractCodecFactory<JSONCodec<?>> {
private static final class EagerCacheLoader extends CacheLoader<SchemaContext, JSONCodecFactory> {
@Override
public JSONCodecFactory load(final SchemaContext key) {
final Stopwatch sw = Stopwatch.createStarted();
final LazyCodecCache<JSONCodec<?>> lazyCache = new LazyCodecCache<>();
final JSONCodecFactory lazy = new JSONCodecFactory(key, lazyCache);
final int visitedLeaves = requestCodecsForChildren(lazy, key);
sw.stop();
final PrecomputedCodecCache<JSONCodec<?>> cache = lazyCache.toPrecomputed();
LOG.debug("{} leaf nodes resulted in {} simple and {} complex codecs in {}", visitedLeaves,
cache.simpleSize(), cache.complexSize(), sw);
return new JSONCodecFactory(key, cache);
}
private static int requestCodecsForChildren(final JSONCodecFactory lazy, final DataNodeContainer parent) {
int ret = 0;
for (DataSchemaNode child : parent.getChildNodes()) {
if (child instanceof TypedSchemaNode) {
lazy.codecFor((TypedSchemaNode) child);
++ret;
} else if (child instanceof DataNodeContainer) {
ret += requestCodecsForChildren(lazy, (DataNodeContainer) child);
}
}
return ret;
}
}
private static final Logger LOG = LoggerFactory.getLogger(JSONCodecFactory.class);
// Weak keys to retire the entry when SchemaContext goes away
private static final LoadingCache<SchemaContext, JSONCodecFactory> PRECOMPUTED = CacheBuilder.newBuilder()
.weakKeys().build(new EagerCacheLoader());
// Weak keys to retire the entry when SchemaContext goes away and to force identity-based lookup
private static final LoadingCache<SchemaContext, JSONCodecFactory> SHARED = CacheBuilder.newBuilder()
.weakKeys().build(new CacheLoader<SchemaContext, JSONCodecFactory>() {
@Override
public JSONCodecFactory load(final SchemaContext key) {
return new JSONCodecFactory(key, new SharedCodecCache<>());
}
});
private final JSONCodec<?> iidCodec;
JSONCodecFactory(final SchemaContext context, final CodecCache<JSONCodec<?>> cache) {
super(context, cache);
iidCodec = new JSONStringInstanceIdentifierCodec(context, this);
}
/**
* Instantiate a new codec factory attached to a particular context.
*
* @param context SchemaContext to which the factory should be bound
* @return A codec factory instance.
*
* @deprecated Use {@link #getShared(SchemaContext)} instead.
*/
@Deprecated
public static JSONCodecFactory create(final SchemaContext context) {
return getShared(context);
}
/**
* Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
* return the same instance as long as the associated SchemaContext is present. Returned object can be safely
* used by multiple threads concurrently. If the SchemaContext instance does not have a cached instance
* of {@link JSONCodecFactory}, it will be completely precomputed before this method will return.
*
* Choosing this implementation is appropriate when the memory overhead of keeping a full codec tree is not as
* great a concern as predictable performance. When compared to the implementation returned by
* {@link #getShared(SchemaContext)}, this implementation is expected to offer higher performance and have lower
* peak memory footprint when most of the SchemaContext is actually in use.
*
* For call sites which do not want to pay the CPU cost of pre-computing this implementation, but still would like
* to use it if is available (by being populated by some other caller), you can use
* {@link #getPrecomputedIfAvailable(SchemaContext)}.
*
* @param context SchemaContext instance
* @return A sharable {@link JSONCodecFactory}
* @throws NullPointerException if context is null
*/
public static JSONCodecFactory getPrecomputed(final SchemaContext context) {
return PRECOMPUTED.getUnchecked(context);
}
/**
* Get a thread-safe, eagerly-caching {@link JSONCodecFactory} for a SchemaContext, if it is available. This
* method is a non-blocking equivalent of {@link #getPrecomputed(SchemaContext)} for use in code paths where
* the potential of having to pre-compute the implementation is not acceptable. One such scenario is when the
* code base wants to opportunistically take advantage of pre-computed version, but is okay with a fallback to
* a different implementation.
*
* @param context SchemaContext instance
* @return A sharable {@link JSONCodecFactory}, or absent if such an implementation is not available.
* @throws NullPointerException if context is null
*/
public static Optional<JSONCodecFactory> getPrecomputedIfAvailable(final SchemaContext context) {
return Optional.fromNullable(PRECOMPUTED.getIfPresent(context));
}
/**
* Get a thread-safe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method can, and will,
* return the same instance as long as the associated SchemaContext is present or the factory is not invalidated
* by memory pressure. Returned object can be safely used by multiple threads concurrently.
*
* Choosing this implementation is a safe default, as it will not incur prohibitive blocking, nor will it tie up
* memory in face of pressure.
*
* @param context SchemaContext instance
* @return A sharable {@link JSONCodecFactory}
* @throws NullPointerException if context is null
*/
public static JSONCodecFactory getShared(final SchemaContext context) {
return SHARED.getUnchecked(context);
}
/**
* Create a new thread-unsafe, lazily-caching {@link JSONCodecFactory} for a SchemaContext. This method will
* return distinct objects every time it is invoked. Returned object may not be used from multiple threads
* concurrently.
*
* This implementation is appropriate for one-off serialization from a single thread. It will aggressively cache
* codecs for reuse and will tie them up in memory until the factory is freed.
*
* @param context SchemaContext instance
* @return A non-sharable {@link JSONCodecFactory}
* @throws NullPointerException if context is null
*/
public static JSONCodecFactory createLazy(final SchemaContext context) {
return new JSONCodecFactory(context, new LazyCodecCache<>());
}
/**
* Create a simplistic, thread-safe {@link JSONCodecFactory} for a {@link SchemaContext}. This method will return
* distinct objects every time it is invoked. Returned object may be use from multiple threads concurrently.
*
* This implementation exists mostly for completeness only, as it does not perform any caching at all and each codec
* is computed every time it is requested. This may be useful in extremely constrained environments, where memory
* footprint is more critical than performance.
*
* @param context SchemaContext instance
* @return A non-sharable {@link JSONCodecFactory}
* @throws NullPointerException if context is null.
*/
public static JSONCodecFactory createSimple(final SchemaContext context) {
return new JSONCodecFactory(context, NoopCodecCache.getInstance());
}
@Override
protected JSONCodec<?> binaryCodec(final BinaryTypeDefinition type) {
return new QuotedJSONCodec<>(BinaryStringCodec.from(type));
}
@Override
protected JSONCodec<?> booleanCodec(final BooleanTypeDefinition type) {
return new BooleanJSONCodec(BooleanStringCodec.from(type));
}
@Override
protected JSONCodec<?> bitsCodec(final BitsTypeDefinition type) {
return new QuotedJSONCodec<>(BitsStringCodec.from(type));
}
@Override
protected JSONCodec<?> decimalCodec(final DecimalTypeDefinition type) {
return new NumberJSONCodec<>(DecimalStringCodec.from(type));
}
@Override
protected JSONCodec<?> emptyCodec(final EmptyTypeDefinition type) {
return EmptyJSONCodec.INSTANCE;
}
@Override
protected JSONCodec<?> enumCodec(final EnumTypeDefinition type) {
return new QuotedJSONCodec<>(EnumStringCodec.from(type));
}
@Override
protected JSONCodec<?> identityRefCodec(final IdentityrefTypeDefinition type, final QNameModule module) {
return new IdentityrefJSONCodec(getSchemaContext(), module);
}
@Override
protected JSONCodec<?> instanceIdentifierCodec(final InstanceIdentifierTypeDefinition type) {
// FIXME: there really are two favors, as 'require-instance true' needs to be validated. In order to deal
// with that, though, we need access to the current data store.
return iidCodec;
}
@Override
protected JSONCodec<?> intCodec(final IntegerTypeDefinition type) {
return new NumberJSONCodec<>(AbstractIntegerStringCodec.from(type));
}
@Override
protected JSONCodec<?> stringCodec(final StringTypeDefinition type) {
return new QuotedJSONCodec<>(StringStringCodec.from(type));
}
@Override
protected JSONCodec<?> uintCodec(final UnsignedIntegerTypeDefinition type) {
return new NumberJSONCodec<>(AbstractIntegerStringCodec.from(type));
}
@Override
protected JSONCodec<?> unionCodec(final UnionTypeDefinition type, final List<JSONCodec<?>> codecs) {
return UnionJSONCodec.create(type, codecs);
}
@Override
protected JSONCodec<?> unknownCodec(final UnknownTypeDefinition type) {
return NullJSONCodec.INSTANCE;
}
}