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 an {@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>) AlwaysReuse.CONTEXT_INDEPENDENT;
70 * Return an {@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 an {@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 an {@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 Rejecting 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);
107 abstract boolean canReuseCurrent(@NonNull Current<A, D> copy, @NonNull Current<A, D> current,
108 @NonNull Collection<? extends EffectiveStatement<?, ?>> substatements);
111 @SuppressWarnings("unchecked")
112 static <A, D extends DeclaredStatement<A>> StatementPolicy<A, D> compat(final CopyPolicy copyPolicy) {
113 switch (copyPolicy) {
114 case CONTEXT_INDEPENDENT:
115 return contextIndependent();
117 return (StatementPolicy<A, D>) AlwaysCopy.DECLARED_COPY;
123 throw new IllegalStateException("Unsupported policy " + copyPolicy);
127 private static final class AlwaysCopy<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
129 static final @NonNull AlwaysCopy<?, ?> DECLARED_COPY = new AlwaysCopy<>(CopyPolicy.DECLARED_COPY);
131 AlwaysCopy(final CopyPolicy copyPolicy) {
136 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
137 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
142 private static final class AlwaysReuse<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
143 static final @NonNull AlwaysReuse<?, ?> CONTEXT_INDEPENDENT =
144 new AlwaysReuse<>(CopyPolicy.CONTEXT_INDEPENDENT);
146 private AlwaysReuse(final CopyPolicy copyPolicy) {
151 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
152 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
157 private static final class AlwaysFail<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
158 static final @NonNull AlwaysFail<?, ?> IGNORE = new AlwaysFail<>(CopyPolicy.IGNORE);
159 static final @NonNull AlwaysFail<?, ?> REJECT = new AlwaysFail<>(CopyPolicy.REJECT);
161 private AlwaysFail(final CopyPolicy copyPolicy) {
166 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
167 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
168 throw new VerifyException("This implementation should never be invoked");
172 private static final class EqualSemantics<A, D extends DeclaredStatement<A>> extends StatementPolicy<A, D> {
173 private final @NonNull StatementEquality<A, D> equality;
175 EqualSemantics(final @NonNull StatementEquality<A, D> equality) {
176 super(CopyPolicy.DECLARED_COPY);
177 this.equality = requireNonNull(equality);
181 boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
182 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
183 return equality.canReuseCurrent(copy, current, substatements);
189 * Abstract base class for comparators associated with statements with a {@link CopyPolicy#DECLARED_COPY} copy
192 * @param <A> Argument type
193 * @param <D> Declared Statement representation
196 public interface StatementEquality<A, D extends DeclaredStatement<A>> {
198 * Determine whether {@code current} statement has the same semantics as the provided copy. See the contract
199 * specification of {@link StatementFactory#canReuseCurrent(Current, Current, Collection)}.
201 * @param copy Copy of current effective context
202 * @param current Current effective context
203 * @param substatements Current effective substatements
204 * @return True if {@code current} can be reused in place of {@code copy}, false if the copy needs to be used.
206 boolean canReuseCurrent(@NonNull Current<A, D> copy, @NonNull Current<A, D> current,
207 @NonNull Collection<? extends EffectiveStatement<?, ?>> substatements);
210 private final @NonNull StatementPolicy<A, D> policy;
211 private final @NonNull StatementDefinition def;
212 private final @NonNull CopyPolicy copyPolicy;
215 protected StatementSupport(final StatementDefinition publicDefinition, final StatementPolicy<A, D> policy) {
216 checkArgument(publicDefinition != this);
217 this.def = requireNonNull(publicDefinition);
218 this.policy = requireNonNull(policy);
219 this.copyPolicy = policy.copyPolicy;
224 // FIXME: remove this constructor
225 protected StatementSupport(final StatementDefinition publicDefinition, final CopyPolicy copyPolicy) {
226 this(publicDefinition, StatementPolicy.compat(copyPolicy));
230 * Returns public statement definition, which will be present in built statements.
233 * Public statement definition may be used to provide different implementation of statement definition,
234 * which will not retain any build specific data or context.
236 * @return public statement definition, which will be present in built statements.
238 public final @NonNull StatementDefinition getPublicView() {
243 * Return this statement's {@link CopyPolicy}. This is a static value, reflecting how this statement reacts to being
244 * replicated to a different context, without reflecting on behaviour of potential substatements, which would come
245 * into play in something like:
259 * description "Can be used in description/reference statements to attach additional notes";
262 * description "A nice module extending description statement semantics" {
263 * foo:note "We can now attach description/reference a note.";
264 * foo:note "Also another note";
271 * In this scenario, it is the reactor's job to figure out what to do (like talking to substatements).
273 * @return This statement's copy policy
275 public final @NonNull CopyPolicy copyPolicy() {
280 public final boolean canReuseCurrent(final Current<A, D> copy, final Current<A, D> current,
281 final Collection<? extends EffectiveStatement<?, ?>> substatements) {
282 return policy.canReuseCurrent(copy, current, substatements);
286 * Parses textual representation of argument in object representation.
288 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
289 * @param value String representation of value, as was present in text source.
290 * @return Parsed value
291 * @throws SourceException when an inconsistency is detected.
293 public abstract A parseArgumentValue(StmtContext<?, ?, ?> ctx, String value);
296 * Adapts the argument value to match a new module. Default implementation returns original value stored in context,
297 * which is appropriate for most implementations.
299 * @param ctx Context, which may be used to access source-specific namespaces required for parsing.
300 * @param targetModule Target module, may not be null.
301 * @return Adapted argument value.
303 public A adaptArgumentValue(final @NonNull StmtContext<A, D, E> ctx, final @NonNull QNameModule targetModule) {
304 return ctx.argument();
308 * Invoked when a statement supported by this instance is added to build context. This allows implementations
309 * of this interface to start tracking the statement and perform any modifications to the build context hierarchy,
310 * accessible via {@link StmtContext#getParentContext()}. One such use is populating the parent's namespaces to
311 * allow it to locate this child statement.
313 * @param stmt Context of added statement. No substatements are available.
315 public void onStatementAdded(final @NonNull Mutable<A, D, E> stmt) {
316 // NOOP for most implementations
320 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_PRE_LINKAGE} phase, only substatements
321 * from this and previous phase are available.
324 * Implementation may use method to perform actions on this event or register modification action using
325 * {@link Mutable#newInferenceAction(ModelProcessingPhase)}.
327 * @param stmt Context of added statement.
329 public void onPreLinkageDeclared(final @NonNull Mutable<A, D, E> stmt) {
330 // NOOP for most implementations
334 * Invoked when statement is closed during {@link ModelProcessingPhase#SOURCE_LINKAGE} phase, only substatements
335 * from this and previous phase are available.
338 * Implementation may use method to perform actions on this event or register modification action using
339 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
341 * @param stmt Context of added statement.
342 * @throws SourceException when an inconsistency is detected.
344 public void onLinkageDeclared(final @NonNull Mutable<A, D, E> stmt) {
345 // NOOP for most implementations
349 * Invoked when statement is closed during {@link ModelProcessingPhase#STATEMENT_DEFINITION} phase,
350 * only substatements from this phase are available.
353 * Implementation may use method to perform actions on this event or register modification action using
354 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
356 * @param stmt Context of added statement. Argument and statement parent is accessible.
357 * @throws SourceException when an inconsistency is detected.
359 public void onStatementDefinitionDeclared(final Mutable<A, D, E> stmt) {
360 // NOOP for most implementations
364 * Invoked when statement is closed during {@link ModelProcessingPhase#FULL_DECLARATION} phase,
365 * only substatements from this phase are available.
368 * Implementation may use method to perform actions on this event or register modification action using
369 * {@link StmtContext.Mutable#newInferenceAction(ModelProcessingPhase)}.
371 * @param stmt Context of added statement. Argument and statement parent is accessible.
372 * @throws SourceException when an inconsistency is detected.
374 public void onFullDefinitionDeclared(final StmtContext.Mutable<A, D, E> stmt) {
375 final SubstatementValidator validator = getSubstatementValidator();
376 if (validator != null) {
377 validator.validate(stmt);
382 * Returns corresponding substatement validator of a statement support.
384 * @return substatement validator or null, if substatement validator is not defined
386 // FIXME: rename to 'substatementValidator' and perhaps let it be passed in?
387 protected abstract @Nullable SubstatementValidator getSubstatementValidator();
390 * Returns true if this support has argument specific supports.
392 public boolean hasArgumentSpecificSupports() {
393 // Most of statement supports don't have any argument specific supports, so return 'false'.
398 * If this support has argument specific supports, the method returns support specific for given argument
399 * (e.g. type statement support need to be specialized based on its argument), otherwise returns null.
401 * @param argument argument of statement
402 * @return statement support specific for supplied argument or null
404 public @Nullable StatementSupport<?, ?, ?> getSupportSpecificForArgument(final String argument) {
405 // Most of statement supports don't have any argument specific supports, so return null.
410 * Given a raw string representation of an argument, try to use a shared representation. Default implementation
413 * @param rawArgument Argument string
414 * @return A potentially-shard instance
416 public String internArgument(final String rawArgument) {
421 * Returns unknown statement form of a regular YANG statement supplied as a parameter to the method. Default
422 * implementation does nothing.
424 * @param yangStmtDef statement definition of a regular YANG statement
425 * @return Optional of unknown statement form of a regular YANG statement or empty() if it is not supported by this
428 public Optional<StatementSupport<?, ?, ?>> getUnknownStatementDefinitionOf(final StatementDefinition yangStmtDef) {
429 return Optional.empty();
433 * Returns true if this statement support and all its substatements ignore if-feature statements (e.g. yang-data
434 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
435 * implementation returns false.
437 * @return true if this statement support ignores if-feature statements, otherwise false.
440 public boolean isIgnoringIfFeatures() {
445 * Returns true if this statement support and all its substatements ignore config statements (e.g. yang-data
446 * extension defined in <a href="https://tools.ietf.org/html/rfc8040#section-8">RFC 8040</a>). Default
447 * implementation returns false.
449 * @return true if this statement support ignores config statements,
453 public boolean isIgnoringConfig() {
458 public final QName getStatementName() {
459 return def.getStatementName();
463 public final Optional<ArgumentDefinition> getArgumentDefinition() {
464 return def.getArgumentDefinition();
468 // Non-final for compatible extensions
469 public Class<? extends DeclaredStatement<?>> getDeclaredRepresentationClass() {
470 return def.getDeclaredRepresentationClass();
474 // Non-final for compatible extensions
475 public Class<? extends EffectiveStatement<?,?>> getEffectiveRepresentationClass() {
476 return def.getEffectiveRepresentationClass();
480 * Statement context copy policy, indicating how should reactor handle statement copy operations. Every statement
481 * copied by the reactor is subject to this policy.
483 public enum CopyPolicy {
485 * Reuse the source statement context in the new place, as it cannot be affected by any further operations. This
486 * implies that the semantics of the effective statement are not affected by any of its substatements. Each
487 * of the substatements is free to make its own policy.
490 * This policy is typically used by static constant statements such as {@code description} or {@code length},
491 * where the baseline RFC7950 does not allow any impact. A {@code description} could hold an extension statement
492 * in which case this interaction would come into play. Normal YANG will see empty substatements, so the reactor
493 * will be free to complete reuse the context.
496 * In case any substatement is of stronger policy, it is up to the reactor to handle correct handling of
497 * resulting subobjects.
499 // TODO: does this mean source must have transitioned to ModelProcessingPhase.EFFECTIVE_MODEL?
502 * Create a copy sharing declared instance, but otherwise having a separate disconnected lifecycle.
504 // TODO: will the copy transition to ModelProcessingPhase.FULL_DECLARATION or which phase?
507 * Reject any attempt to copy this statement. This is useful for statements that are defined as top-level
508 * constructs, such as {@code contact}, {@code deviation} and similar.
512 * Ignore this statement's existence for the purposes of the new place -- it is not impacted. This guidance
513 * is left here for completeness, as it can have justifiable uses (but I can't think of any). Any substatements
514 * need to be ignored, too.