2 * Copyright (c) 2015 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.parser.spi.meta;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static java.util.Objects.requireNonNull;
13 import com.google.common.annotations.Beta;
14 import com.google.common.base.VerifyException;
15 import java.util.Collection;
16 import java.util.Optional;
17 import org.eclipse.jdt.annotation.NonNull;
18 import org.eclipse.jdt.annotation.Nullable;
19 import org.opendaylight.yangtools.concepts.Immutable;
20 import org.opendaylight.yangtools.yang.common.QName;
21 import org.opendaylight.yangtools.yang.common.QNameModule;
22 import org.opendaylight.yangtools.yang.model.api.meta.ArgumentDefinition;
23 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
24 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
25 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
26 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
27 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
28 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
31 * Support for processing concrete YANG statement.
34 * This interface is intended to be implemented by developers, which want to introduce support of statement to parser.
35 * Consider subclassing {@link AbstractStatementSupport} for easier implementation of this interface.
37 * @param <A> Argument type
38 * @param <D> Declared Statement representation
39 * @param <E> Effective Statement representation
41 public abstract class StatementSupport<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
42 implements StatementDefinition, StatementFactory<A, D, E> {
44 * A baseline class for implementing the {@link StatementFactory#canReuseCurrent(Current, Current, Collection)}
45 * contract in a manner which is consistent with a statement's {@link CopyPolicy}.
47 * @param <A> Argument type
48 * @param <D> Declared Statement representation
50 public abstract static class StatementPolicy<A, D extends DeclaredStatement<A>> implements Immutable {
51 final @NonNull CopyPolicy copyPolicy;
53 StatementPolicy(final CopyPolicy copyPolicy) {
54 this.copyPolicy = requireNonNull(copyPolicy);
58 * Return a {@link StatementPolicy} for {@link CopyPolicy#CONTEXT_INDEPENDENT}.
60 * @param <A> Argument type
61 * @param <D> Declared Statement representation
62 * @return Context-independent policy
64 @SuppressWarnings("unchecked")
65 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> contextIndependent() {
66 return (StatementPolicy<A, D>) EqualSemantics.CONTEXT_INDEPENDENT;
70 * Return a {@link StatementPolicy} for {@link CopyPolicy#IGNORE}.
72 * @param <A> Argument type
73 * @param <D> Declared Statement representation
74 * @return Ignoring policy
76 @SuppressWarnings("unchecked")
77 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> ignore() {
78 return (StatementPolicy<A, D>) AlwaysFail.IGNORE;
82 * Return a {@link StatementPolicy} for {@link CopyPolicy#REJECT}.
84 * @param <A> Argument type
85 * @param <D> Declared Statement representation
86 * @return Rejecting statement policy
88 @SuppressWarnings("unchecked")
89 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> reject() {
90 return (StatementPolicy<A, D>) AlwaysFail.REJECT;
94 * Return a {@link StatementPolicy} for {@link CopyPolicy#DECLARED_COPY}, deferring to a
95 * {@link StatementEquality} for individual decisions.
97 * @param <A> Argument type
98 * @param <D> Declared Statement representation
99 * @param equality {@link StatementEquality} to apply to effective statements
100 * @return Equality-based statement policy
102 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> copyDeclared(
103 final @NonNull StatementEquality<A, D> equality) {
104 return new EqualSemantics<>(equality);
108 * Return a {@link StatementPolicy} for {@link CopyPolicy#DECLARED_COPY}, always performing a copy operation.
110 * @param <A> Argument type
111 * @param <D> Declared Statement representation
112 * @return Rejecting statement policy
114 @SuppressWarnings("unchecked")
115 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> alwaysCopyDeclared() {
116 return (StatementPolicy<A, D>) EqualSemantics.ALWAYS_COPY;
119 @Deprecated(forRemoval = true)
120 // FIXME: 7.0.0: remove this method
121 public static final <A, D extends DeclaredStatement<A>> @NonNull StatementPolicy<A, D> legacyDeclaredCopy() {
122 return alwaysCopyDeclared();
125 abstract boolean canReuseCurrent(@NonNull Current<A, D> copy, @NonNull Current<A, D> current,
126 @NonNull Collection<? extends EffectiveStatement<?, ?>> substatements);
128 private static final class AlwaysFail<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
129 static final @NonNull AlwaysFail<?, ?> IGNORE = new AlwaysFail<>(CopyPolicy.IGNORE);
130 static final @NonNull AlwaysFail<?, ?> REJECT = new AlwaysFail<>(CopyPolicy.REJECT);
132 private AlwaysFail(final CopyPolicy copyPolicy) {
137 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
138 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
139 throw new VerifyException("This implementation should never be invoked");
143 private static final class EqualSemantics<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
144 static final @NonNull EqualSemantics<?, ?> ALWAYS_COPY =
145 new EqualSemantics<>((copy, stmt, substatements) -> false);
146 static final @NonNull EqualSemantics<?, ?> CONTEXT_INDEPENDENT =
147 new EqualSemantics<>(CopyPolicy.CONTEXT_INDEPENDENT, (copy, stmt, substatements) -> true);
149 private final @NonNull StatementEquality<A, D> equality;
151 private EqualSemantics(final CopyPolicy copyPolicy, final StatementEquality<A, D> equality) {
153 this.equality = requireNonNull(equality);
156 EqualSemantics(final StatementEquality<A, D> equality) {
157 this(CopyPolicy.DECLARED_COPY, equality);
161 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
162 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
163 return equality.canReuseCurrent(copy, current, substatements);
169 * Abstract base class for comparators associated with statements with a {@link CopyPolicy#DECLARED_COPY} copy
172 * @param <A> Argument type
173 * @param <D> Declared Statement representation
176 public interface StatementEquality<A, D extends DeclaredStatement<A>> {
178 * Determine whether {@code current} statement has the same semantics as the provided copy. See the contract
179 * specification of {@link StatementFactory#canReuseCurrent(Current, Current, Collection)}.
181 * @param copy Copy of current effective context
182 * @param current Current effective context
183 * @param substatements Current effective substatements
184 * @return True if {@code current} can be reused in place of {@code copy}, false if the copy needs to be used.
186 boolean canReuseCurrent(@NonNull Current<A, D> copy, @NonNull Current<A, D> current,
187 @NonNull Collection<? extends EffectiveStatement<?, ?>> substatements);
190 private final @NonNull StatementPolicy<A, D> policy;
191 private final @NonNull StatementDefinition def;
192 private final @NonNull CopyPolicy copyPolicy;
195 protected StatementSupport(final StatementSupport<A, D, E> delegate) {
196 checkArgument(delegate != this);
197 this.def = delegate.def;
198 this.policy = delegate.policy;
199 this.copyPolicy = delegate.copyPolicy;
203 protected StatementSupport(final StatementDefinition publicDefinition, final StatementPolicy<A, D> policy) {
204 checkArgument(publicDefinition != this);
205 this.def = requireNonNull(publicDefinition);
206 this.policy = requireNonNull(policy);
207 this.copyPolicy = policy.copyPolicy;
211 * Returns public statement definition, which will be present in built statements.
214 * Public statement definition may be used to provide different implementation of statement definition,
215 * which will not retain any build specific data or context.
217 * @return public statement definition, which will be present in built statements.
219 public final @NonNull StatementDefinition getPublicView() {
224 * Return this statement's {@link CopyPolicy}. This is a static value, reflecting how this statement reacts to being
225 * replicated to a different context, without reflecting on behaviour of potential substatements, which would come
226 * into play in something like:
240 * description "Can be used in description/reference statements to attach additional notes";
243 * description "A nice module extending description statement semantics" {
244 * foo:note "We can now attach description/reference a note.";
245 * foo:note "Also another note";
252 * In this scenario, it is the reactor's job to figure out what to do (like talking to substatements).
254 * @return This statement's copy policy
256 public final @NonNull CopyPolicy copyPolicy() {
261 public final boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
262 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
263 return policy.canReuseCurrent(copy, current, substatements);
267 * Parses textual representation of argument in object representation.
269 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
270 * @param value String representation of value, as was present in text source.
271 * @return Parsed value
272 * @throws SourceException when an inconsistency is detected.
274 public abstract A parseArgumentValue(StmtContext<?, ?, ?> ctx, String value);
277 * Adapts the argument value to match a new module. Default implementation returns original value stored in context,
278 * which is appropriate for most implementations.
280 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
281 * @param targetModule Target module, may not be null.
282 * @return Adapted argument value.
284 public A adaptArgumentValue(final @NonNull StmtContext<A, D, E> ctx, final @NonNull QNameModule targetModule) {
285 return ctx.argument();
289 * Invoked when a statement supported by this instance is added to build context. This allows implementations
290 * of this interface to start tracking the statement and perform any modifications to the build context hierarchy,
291 * accessible via {@link StmtContext#getParentContext()}. One such use is populating the parent's namespaces to
292 * allow it to locate this child statement.
294 * @param stmt Context of added statement. No substatements are available.
296 public void onStatementAdded(final @NonNull Mutable<A, D, E> stmt) {
297 // NOOP for most implementations
301 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_PRE_LINKAGE} phase, only substatements
302 * from this and previous phase are available.
305 * Implementation may use method to perform actions on this event or register modification action using
306 * {@link Mutable#newInferenceAction(ModelProcessingPhase)}.
308 * @param stmt Context of added statement.
310 public void onPreLinkageDeclared(final @NonNull Mutable<A, D, E> stmt) {
311 // NOOP for most implementations
315 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_LINKAGE} phase, only substatements
316 * from this and previous phase are available.
319 * Implementation may use method to perform actions on this event or register modification action using
320 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
322 * @param stmt Context of added statement.
323 * @throws SourceException when an inconsistency is detected.
325 public void onLinkageDeclared(final @NonNull Mutable<A, D, E> stmt) {
326 // NOOP for most implementations
330 * Invoked when statement is closed during {@link ModelProcessingPhase#STATEMENT_DEFINITION} phase,
331 * only substatements from this phase are available.
334 * Implementation may use method to perform actions on this event or register modification action using
335 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
337 * @param stmt Context of added statement. Argument and statement parent is accessible.
338 * @throws SourceException when an inconsistency is detected.
340 public void onStatementDefinitionDeclared(final Mutable<A, D, E> stmt) {
341 // NOOP for most implementations
345 * Invoked when statement is closed during {@link ModelProcessingPhase#FULL_DECLARATION} phase,
346 * only substatements from this phase are available.
349 * Implementation may use method to perform actions on this event or register modification action using
350 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
352 * @param stmt Context of added statement. Argument and statement parent is accessible.
353 * @throws SourceException when an inconsistency is detected.
355 public void onFullDefinitionDeclared(final StmtContext.Mutable<A, D, E> stmt) {
356 final SubstatementValidator validator = getSubstatementValidator();
357 if (validator != null) {
358 validator.validate(stmt);
363 * Returns corresponding substatement validator of a statement support.
365 * @return substatement validator or null, if substatement validator is not defined
367 // FIXME: rename to 'substatementValidator' and perhaps let it be passed in?
368 protected abstract @Nullable SubstatementValidator getSubstatementValidator();
371 * Returns true if this support has argument specific supports.
373 public boolean hasArgumentSpecificSupports() {
374 // Most of statement supports don't have any argument specific supports, so return 'false'.
379 * If this support has argument specific supports, the method returns support specific for given argument
380 * (e.g. type statement support need to be specialized based on its argument), otherwise returns null.
382 * @param argument argument of statement
383 * @return statement support specific for supplied argument or null
385 public @Nullable StatementSupport<?, ?, ?> getSupportSpecificForArgument(final String argument) {
386 // Most of statement supports don't have any argument specific supports, so return null.
391 * Given a raw string representation of an argument, try to use a shared representation. Default implementation
394 * @param rawArgument Argument string
395 * @return A potentially-shard instance
397 public String internArgument(final String rawArgument) {
402 * Returns unknown statement form of a regular YANG statement supplied as a parameter to the method. Default
403 * implementation does nothing.
405 * @param yangStmtDef statement definition of a regular YANG statement
406 * @return Optional of unknown statement form of a regular YANG statement or empty() if it is not supported by this
409 public Optional<StatementSupport<?, ?, ?>> getUnknownStatementDefinitionOf(final StatementDefinition yangStmtDef) {
410 return Optional.empty();
414 * Returns true if this statement support and all its substatements ignore if-feature statements (e.g. yang-data
415 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
416 * implementation returns false.
418 * @return true if this statement support ignores if-feature statements, otherwise false.
421 public boolean isIgnoringIfFeatures() {
426 * Returns true if this statement support and all its substatements ignore config statements (e.g. yang-data
427 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
428 * implementation returns false.
430 * @return true if this statement support ignores config statements,
434 public boolean isIgnoringConfig() {
439 public final QName getStatementName() {
440 return def.getStatementName();
444 public final Optional<ArgumentDefinition> getArgumentDefinition() {
445 return def.getArgumentDefinition();
449 // Non-final for compatible extensions
450 public Class<? extends DeclaredStatement<?>> getDeclaredRepresentationClass() {
451 return def.getDeclaredRepresentationClass();
455 // Non-final for compatible extensions
456 public Class<? extends EffectiveStatement<?,?>> getEffectiveRepresentationClass() {
457 return def.getEffectiveRepresentationClass();
461 * Statement context copy policy, indicating how should reactor handle statement copy operations. Every statement
462 * copied by the reactor is subject to this policy.
464 public enum CopyPolicy {
466 * Reuse the source statement context in the new place, as it cannot be affected by any further operations. This
467 * implies that the semantics of the effective statement are not affected by any of its substatements. Each
468 * of the substatements is free to make its own policy.
471 * This policy is typically used by static constant statements such as {@code description} or {@code length},
472 * where the baseline RFC7950 does not allow any impact. A {@code description} could hold an extension statement
473 * in which case this interaction would come into play. Normal YANG will see empty substatements, so the reactor
474 * will be free to complete reuse the context.
477 * In case any substatement is of stronger policy, it is up to the reactor to handle correct handling of
478 * resulting subobjects.
480 // TODO: does this mean source must have transitioned to ModelProcessingPhase.EFFECTIVE_MODEL?
483 * Create a copy sharing declared instance, but otherwise having a separate disconnected lifecycle.
485 // TODO: will the copy transition to ModelProcessingPhase.FULL_DECLARATION or which phase?
488 * Reject any attempt to copy this statement. This is useful for statements that are defined as top-level
489 * constructs, such as {@code contact}, {@code deviation} and similar.
493 * Ignore this statement's existence for the purposes of the new place -- it is not impacted. This guidance
494 * is left here for completeness, as it can have justifiable uses (but I can't think of any). Any substatements
495 * need to be ignored, too.