2 * Copyright (c) 2020 PANTHEON.tech, 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.parser.spi.meta;
10 import com.google.common.annotations.Beta;
11 import com.google.common.cache.CacheBuilder;
12 import com.google.common.cache.CacheLoader;
13 import com.google.common.cache.LoadingCache;
14 import com.google.common.collect.ImmutableList;
15 import org.eclipse.jdt.annotation.NonNull;
16 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
17 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
18 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
19 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
22 * A {@link AbstractStatementSupport} specialized for global interning. This base class is useful when the argument can
23 * be reasonably interned and it dominates the {@link EffectiveStatement} implementation. Typical examples include
24 * {@code position} and {@code value} statements, which typically do not have substatements and are based on simple
28 * Note: use of this base class implies context-independence.
31 public abstract class AbstractInternedStatementSupport<A, D extends DeclaredStatement<A>,
32 E extends EffectiveStatement<A, D>> extends AbstractStatementSupport<A, D, E> {
33 private final LoadingCache<A, D> declaredCache = CacheBuilder.newBuilder().weakValues()
34 .build(new CacheLoader<A, D>() {
36 public D load(final A key) {
37 return createEmptyDeclared(key);
40 private final LoadingCache<D, E> effectiveCache = CacheBuilder.newBuilder().weakValues()
41 .build(new CacheLoader<D, E>() {
43 public E load(final D key) {
44 return createEmptyEffective(key);
48 protected AbstractInternedStatementSupport(final StatementDefinition publicDefinition,
49 final StatementPolicy<A, D> policy) {
50 super(publicDefinition, policy);
54 protected final D createEmptyDeclared(final StmtContext<A, D, ?> ctx) {
55 return declaredCache.getUnchecked(ctx.getArgument());
58 protected abstract @NonNull D createEmptyDeclared(@NonNull A argument);
61 protected final E createEffective(final Current<A, D> stmt,
62 final ImmutableList<? extends EffectiveStatement<?, ?>> substatements) {
63 return substatements.isEmpty() ? effectiveCache.getUnchecked(stmt.declared())
64 : createEffective(stmt.declared(), substatements);
67 protected abstract @NonNull E createEffective(@NonNull D declared,
68 @NonNull ImmutableList<? extends EffectiveStatement<?, ?>> substatements);
70 protected abstract @NonNull E createEmptyEffective(@NonNull D declared);
73 protected final D createDeclared(final StmtContext<A, D, ?> ctx,
74 final ImmutableList<? extends DeclaredStatement<?>> substatements) {
75 return createDeclared(ctx.getArgument(), substatements);
78 protected abstract @NonNull D createDeclared(@NonNull A argument,
79 ImmutableList<? extends DeclaredStatement<?>> substatements);