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.stmt.reactor;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static com.google.common.base.Verify.verify;
12 import static com.google.common.base.Verify.verifyNotNull;
14 import com.google.common.base.MoreObjects;
15 import com.google.common.base.MoreObjects.ToStringHelper;
16 import com.google.common.base.VerifyException;
17 import java.util.Collection;
19 import java.util.Optional;
21 import org.eclipse.jdt.annotation.NonNull;
22 import org.eclipse.jdt.annotation.Nullable;
23 import org.opendaylight.yangtools.yang.common.QName;
24 import org.opendaylight.yangtools.yang.common.QNameModule;
25 import org.opendaylight.yangtools.yang.common.YangVersion;
26 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
27 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
28 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
30 import org.opendaylight.yangtools.yang.model.api.stmt.AugmentStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.ConfigEffectiveStatement;
32 import org.opendaylight.yangtools.yang.model.api.stmt.DeviationStatement;
33 import org.opendaylight.yangtools.yang.model.api.stmt.RefineStatement;
34 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier;
35 import org.opendaylight.yangtools.yang.model.api.stmt.UsesStatement;
36 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
37 import org.opendaylight.yangtools.yang.parser.spi.meta.CopyType;
38 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStatementState;
39 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
40 import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
41 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
42 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
43 import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour.Registry;
44 import org.opendaylight.yangtools.yang.parser.spi.meta.ParserNamespace;
45 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
46 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
47 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
48 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
49 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace;
50 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace.SupportedFeatures;
51 import org.slf4j.Logger;
52 import org.slf4j.LoggerFactory;
55 * Real "core" reactor statement implementation of {@link Mutable}, supporting basic reactor lifecycle.
57 * @param <A> Argument type
58 * @param <D> Declared Statement representation
59 * @param <E> Effective Statement representation
61 abstract class ReactorStmtCtx<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
62 extends NamespaceStorageSupport implements Mutable<A, D, E>, Current<A, D> {
63 private static final Logger LOG = LoggerFactory.getLogger(ReactorStmtCtx.class);
66 * Substatement refcount tracking. This mechanics deals with retaining substatements for the purposes of
67 * instantiating their lazy copies in InferredStatementContext. It works in concert with {@link #buildEffective()}
68 * and {@link #declared()}: declared/effective statement views hold an implicit reference and refcount-based
69 * sweep is not activated until they are done (or this statement is not {@link #isSupportedToBuildEffective}).
72 * Reference count is hierarchical in that parent references also pin down their child statements and do not allow
76 * The counter's positive values are tracking incoming references via {@link #incRef()}/{@link #decRef()} methods.
77 * Once we transition to sweeping, this value becomes negative counting upwards to {@link #REFCOUNT_NONE} based on
78 * {@link #sweepOnChildDone()}. Once we reach that, we transition to {@link #REFCOUNT_SWEPT}.
80 private int refcount = REFCOUNT_NONE;
82 * No outstanding references, this statement is a potential candidate for sweeping, provided it has populated its
83 * declared and effective views and {@link #parentRef} is known to be absent.
85 private static final int REFCOUNT_NONE = 0;
87 * Reference count overflow or some other recoverable logic error. Do not rely on refcounts and do not sweep
91 * Note on value assignment:
92 * This allow our incRef() to naturally progress to being saturated. Others jump there directly.
93 * It also makes it it impossible to observe {@code Interger.MAX_VALUE} children, which we take advantage of for
94 * {@link #REFCOUNT_SWEEPING}.
96 private static final int REFCOUNT_DEFUNCT = Integer.MAX_VALUE;
98 * This statement is being actively swept. This is a transient value set when we are sweeping our children, so that
99 * we prevent re-entering this statement.
102 * Note on value assignment:
103 * The value is lower than any legal child refcount due to {@link #REFCOUNT_DEFUNCT} while still being higher than
104 * {@link #REFCOUNT_SWEPT}.
106 private static final int REFCOUNT_SWEEPING = -Integer.MAX_VALUE;
108 * This statement, along with its entire subtree has been swept and we positively know all our children have reached
109 * this state. We {@link #sweepNamespaces()} upon reaching this state.
112 * Note on value assignment:
113 * This is the lowest value observable, making it easier on checking others on equality.
115 private static final int REFCOUNT_SWEPT = Integer.MIN_VALUE;
118 * Effective instance built from this context. This field as dual types. Under normal circumstances in matches the
119 * {@link #buildEffective()} instance. If this context is reused, it can be inflated to {@link EffectiveInstances}
120 * and also act as a common instance reuse site.
122 private @Nullable Object effectiveInstance;
124 // Master flag controlling whether this context can yield an effective statement
125 // FIXME: investigate the mechanics that are being supported by this, as it would be beneficial if we can get rid
126 // of this flag -- eliminating the initial alignment shadow used by below gap-filler fields.
127 private boolean isSupportedToBuildEffective = true;
129 // EffectiveConfig mapping
130 private static final int MASK_CONFIG = 0x03;
131 private static final int HAVE_CONFIG = 0x04;
132 // Effective instantiation mechanics for StatementContextBase: if this flag is set all substatements are known not
133 // change when instantiated. This includes context-independent statements as well as any statements which are
134 // ignored during copy instantiation.
135 private static final int ALL_INDEPENDENT = 0x08;
136 // Flag bit assignments
137 private static final int IS_SUPPORTED_BY_FEATURES = 0x10;
138 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x20;
139 private static final int IS_IGNORE_IF_FEATURE = 0x40;
140 private static final int HAVE_IGNORE_IF_FEATURE = 0x80;
141 // Have-and-set flag constants, also used as masks
142 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
143 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
145 private static final EffectiveConfig[] EFFECTIVE_CONFIGS;
148 final EffectiveConfig[] values = EffectiveConfig.values();
149 final int length = values.length;
150 verify(length == 4, "Unexpected EffectiveConfig cardinality %s", length);
151 EFFECTIVE_CONFIGS = values;
154 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
155 // hence improve memory layout.
158 // Flag for use by AbstractResumedStatement, ReplicaStatementContext and InferredStatementContext. Each of them
159 // uses it to indicated a different condition. This is hiding in the alignment shadow created by
160 // 'isSupportedToBuildEffective'.
161 // FIXME: move this out once we have JDK15+
162 private boolean boolFlag;
164 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
165 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
166 // FIXME: this should become 'QName'
167 private SchemaPath schemaPath;
173 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
174 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
175 boolFlag = original.boolFlag;
176 flags = original.flags;
179 // Used by ReplicaStatementContext only
180 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original, final Void dummy) {
181 boolFlag = isSupportedToBuildEffective = original.isSupportedToBuildEffective;
182 flags = original.flags;
187 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
188 // up mixing concerns and simple details with more complex logic.
193 public abstract StatementContextBase<?, ?, ?> getParentContext();
196 public abstract RootStatementContext<?, ?, ?> getRoot();
199 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
202 public final @NonNull Registry getBehaviourRegistry() {
203 return getRoot().getBehaviourRegistryImpl();
207 public final YangVersion yangVersion() {
208 return getRoot().getRootVersionImpl();
212 public final void setRootVersion(final YangVersion version) {
213 getRoot().setRootVersionImpl(version);
217 public final void addRequiredSource(final SourceIdentifier dependency) {
218 getRoot().addRequiredSourceImpl(dependency);
222 public final void setRootIdentifier(final SourceIdentifier identifier) {
223 getRoot().setRootIdentifierImpl(identifier);
227 public final boolean isEnabledSemanticVersioning() {
228 return getRoot().isEnabledSemanticVersioningImpl();
232 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
233 return getRoot().getSourceContext().newInferenceAction(phase);
237 public final StatementDefinition publicDefinition() {
238 return definition().getPublicView();
242 public final Parent effectiveParent() {
243 return getParentContext();
247 public final QName moduleName() {
248 final RootStatementContext<?, ?, ?> root = getRoot();
249 return QName.create(StmtContextUtils.getRootModuleQName(root), root.getRawArgument());
253 public final EffectiveStatement<?, ?> original() {
254 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
258 // In the next two methods we are looking for an effective statement. If we already have an effective instance,
259 // defer to it's implementation of the equivalent search. Otherwise we search our substatement contexts.
261 // Note that the search function is split, so as to allow InferredStatementContext to do its own thing first.
265 public final <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgument(
266 final @NonNull Class<Z> type) {
267 final Object existing = effectiveInstance;
268 return existing != null ? EffectiveInstances.local(existing).findFirstEffectiveSubstatementArgument(type)
269 : findSubstatementArgumentImpl(type);
273 public final boolean hasSubstatement(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
274 final Object existing = effectiveInstance;
275 return existing != null ? EffectiveInstances.local(existing).findFirstEffectiveSubstatement(type).isPresent()
276 : hasSubstatementImpl(type);
279 // Visible due to InferredStatementContext's override. At this point we do not have an effective instance available.
280 <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgumentImpl(
281 final @NonNull Class<Z> type) {
282 return allSubstatementsStream()
283 .filter(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type))
285 .map(ctx -> (X) ctx.getArgument());
288 // Visible due to InferredStatementContext's override. At this point we do not have an effective instance available.
289 boolean hasSubstatementImpl(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
290 return allSubstatementsStream()
291 .anyMatch(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type));
296 @SuppressWarnings("unchecked")
297 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
298 return (StmtContext<A, D, Z>) this;
302 public final String toString() {
303 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
306 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
307 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
311 * Return the context in which this statement was defined.
313 * @return statement definition
315 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
319 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
324 public final <K, V, T extends K, N extends ParserNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
326 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
330 public final <K, V, N extends ParserNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
331 return getNamespace(type);
335 public final <K, V, N extends ParserNamespace<K, V>>
336 Map<K, V> localNamespacePortion(final Class<@NonNull N> type) {
337 return getLocalNamespace(type);
341 protected final void checkLocalNamespaceAllowed(final Class<? extends ParserNamespace<?, ?>> type) {
342 definition().checkNamespaceAllowed(type);
346 protected <K, V, N extends ParserNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
348 // definition().onNamespaceElementAdded(this, type, key, value);
352 * Return the effective statement view of a copy operation. This method may return one of:
354 * <li>{@code this}, when the effective view did not change</li>
355 * <li>an InferredStatementContext, when there is a need for inference-equivalent copy</li>
356 * <li>{@code null}, when the statement failed to materialize</li>
359 * @param parent Proposed new parent
360 * @param type Copy operation type
361 * @param targetModule New target module
362 * @return {@link ReactorStmtCtx} holding effective view
364 abstract @Nullable ReactorStmtCtx<?, ?, ?> asEffectiveChildOf(StatementContextBase<?, ?, ?> parent, CopyType type,
365 QNameModule targetModule);
368 public final ReactorStmtCtx<A, D, E> replicaAsChildOf(final Mutable<?, ?, ?> parent) {
369 checkArgument(parent instanceof StatementContextBase, "Unsupported parent %s", parent);
370 return replicaAsChildOf((StatementContextBase<?, ?, ?>) parent);
373 abstract @NonNull ReplicaStatementContext<A, D, E> replicaAsChildOf(@NonNull StatementContextBase<?, ?, ?> parent);
377 // Statement build entry points -- both public and package-private.
382 public final E buildEffective() {
383 final Object existing;
384 return (existing = effectiveInstance) != null ? EffectiveInstances.local(existing) : loadEffective();
387 private @NonNull E loadEffective() {
388 // Creating an effective statement does not strictly require a declared instance -- there are statements like
389 // 'input', which are implicitly defined.
390 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
391 // we attempt to create effective statement:
394 final E ret = createEffective();
395 effectiveInstance = ret;
396 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
398 if (refcount == REFCOUNT_NONE) {
404 abstract @NonNull E createEffective();
408 * Attach an effective copy of this statement. This essentially acts as a map, where we make a few assumptions:
410 * <li>{@code copy} and {@code this} statement share {@link #getOriginalCtx()} if it exists</li>
411 * <li>{@code copy} did not modify any statements relative to {@code this}</li>
415 * @param state effective statement state, acting as a lookup key
416 * @param copy New copy to append
417 * @return {@code copy} or a previously-created instances with the same {@code state}
419 @SuppressWarnings("unchecked")
420 final @NonNull E attachCopy(final @NonNull EffectiveStatementState state, final @NonNull E copy) {
421 final Object effective = verifyNotNull(effectiveInstance, "Attaching copy to a unbuilt %s", this);
422 final EffectiveInstances<E> instances;
423 if (effective instanceof EffectiveInstances) {
424 instances = (EffectiveInstances<E>) effective;
426 effectiveInstance = instances = new EffectiveInstances<>((E) effective);
428 return instances.attachCopy(state, copy);
432 * Walk this statement's copy history and return the statement closest to original which has not had its effective
433 * statements modified. This statement and returned substatement logically have the same set of substatements, hence
434 * share substatement-derived state.
436 * @return Closest {@link ReactorStmtCtx} with equivalent effective substatements
438 abstract @NonNull ReactorStmtCtx<A, D, E> unmodifiedEffectiveSource();
441 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
442 * this method does nothing.
444 * @param phase to be executed (completed)
445 * @return true if phase was successfully completed
446 * @throws SourceException when an error occurred in source parsing
448 final boolean tryToCompletePhase(final ModelProcessingPhase phase) {
449 return phase.isCompletedBy(getCompletedPhase()) || doTryToCompletePhase(phase);
452 abstract boolean doTryToCompletePhase(ModelProcessingPhase phase);
456 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
462 public final boolean isSupportedToBuildEffective() {
463 return isSupportedToBuildEffective;
467 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
468 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
472 public final boolean isSupportedByFeatures() {
473 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
475 return fl == SET_SUPPORTED_BY_FEATURES;
477 if (isIgnoringIfFeatures()) {
478 flags |= SET_SUPPORTED_BY_FEATURES;
483 * If parent is supported, we need to check if-features statements of this context.
485 if (isParentSupportedByFeatures()) {
486 // If the set of supported features has not been provided, all features are supported by default.
487 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
488 SupportedFeatures.SUPPORTED_FEATURES);
489 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
490 flags |= SET_SUPPORTED_BY_FEATURES;
495 // Either parent is not supported or this statement is not supported
496 flags |= HAVE_SUPPORTED_BY_FEATURES;
500 protected abstract boolean isParentSupportedByFeatures();
503 * Config statements are not all that common which means we are performing a recursive search towards the root
504 * every time {@link #effectiveConfig()} is invoked. This is quite expensive because it causes a linear search
505 * for the (usually non-existent) config statement.
508 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
509 * result without performing any lookups, solely to support {@link #effectiveConfig()}.
512 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
513 * {@link #isIgnoringConfig(StatementContextBase)}.
515 final @NonNull EffectiveConfig effectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
516 return (flags & HAVE_CONFIG) != 0 ? EFFECTIVE_CONFIGS[flags & MASK_CONFIG] : loadEffectiveConfig(parent);
519 private @NonNull EffectiveConfig loadEffectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
520 final EffectiveConfig parentConfig = parent.effectiveConfig();
522 final EffectiveConfig myConfig;
523 if (parentConfig != EffectiveConfig.IGNORED && !definition().support().isIgnoringConfig()) {
524 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
525 if (optConfig.isPresent()) {
526 if (optConfig.orElseThrow()) {
527 // Validity check: if parent is config=false this cannot be a config=true
528 InferenceException.throwIf(parentConfig == EffectiveConfig.FALSE, this,
529 "Parent node has config=false, this node must not be specifed as config=true");
530 myConfig = EffectiveConfig.TRUE;
532 myConfig = EffectiveConfig.FALSE;
535 // If "config" statement is not specified, the default is the same as the parent's "config" value.
536 myConfig = parentConfig;
539 myConfig = EffectiveConfig.IGNORED;
542 flags = (byte) (flags & ~MASK_CONFIG | HAVE_CONFIG | myConfig.ordinal());
546 protected abstract boolean isIgnoringConfig();
549 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
550 * keep on returning the same result without performing any lookups. Exists only to support
551 * {@link SubstatementContext#isIgnoringConfig()}.
554 * Note: use of this method implies that {@link #isConfiguration()} is realized with
555 * {@link #effectiveConfig(StatementContextBase)}.
557 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
558 return EffectiveConfig.IGNORED == effectiveConfig(parent);
561 protected abstract boolean isIgnoringIfFeatures();
564 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
565 * keep on returning the same result without performing any lookups. Exists only to support
566 * {@link SubstatementContext#isIgnoringIfFeatures()}.
568 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
569 final int fl = flags & SET_IGNORE_IF_FEATURE;
571 return fl == SET_IGNORE_IF_FEATURE;
573 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
574 flags |= SET_IGNORE_IF_FEATURE;
578 flags |= HAVE_IGNORE_IF_FEATURE;
582 // These two exist only due to memory optimization, should live in AbstractResumedStatement.
583 final boolean fullyDefined() {
587 final void setFullyDefined() {
591 // This exists only due to memory optimization, should live in ReplicaStatementContext. In this context the flag
592 // indicates the need to drop source's reference count when we are being swept.
593 final boolean haveSourceReference() {
597 // These three exist due to memory optimization, should live in InferredStatementContext. In this context the flag
598 // indicates whether or not this statement's substatement file was modified, i.e. it is not quite the same as the
600 final boolean isModified() {
604 final void setModified() {
608 final void setUnmodified() {
612 // These two exist only for StatementContextBase. Since we are squeezed for size, with only a single bit available
613 // in flags, we default to 'false' and only set the flag to true when we are absolutely sure -- and all other cases
614 // err on the side of caution by taking the time to evaluate each substatement separately.
615 final boolean allSubstatementsContextIndependent() {
616 return (flags & ALL_INDEPENDENT) != 0;
619 final void setAllSubstatementsContextIndependent() {
620 flags |= ALL_INDEPENDENT;
625 // Various functionality from AbstractTypeStatementSupport. This used to work on top of SchemaPath, now it still
626 // lives here. Ultimate future is either proper graduation or (more likely) move to AbstractTypeStatementSupport.
631 public final QName argumentAsTypeQName() {
632 final Object argument = argument();
633 verify(argument instanceof String, "Unexpected argument %s", argument);
634 return interpretAsQName((String) argument);
638 public final QNameModule effectiveNamespace() {
639 // FIXME: there has to be a better way to do this
640 return getSchemaPath().getLastComponent().getModule();
645 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
649 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
651 final @Nullable SchemaPath substatementGetSchemaPath() {
652 if (schemaPath == null) {
653 schemaPath = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
658 // FIXME: 7.0.0: this method's logic needs to be moved to the respective StatementSupport classes
660 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
661 final SchemaPath parentPath = parent.getSchemaPath();
662 if (StmtContextUtils.isUnknownStatement(this)) {
663 return parentPath.createChild(publicDefinition().getStatementName());
665 final Object argument = argument();
666 if (argument instanceof QName) {
667 final QName qname = (QName) argument;
668 if (producesDeclared(UsesStatement.class)) {
672 return parentPath.createChild(qname);
674 if (argument instanceof String) {
675 return parentPath.createChild(interpretAsQName((String) argument));
677 if (argument instanceof SchemaNodeIdentifier
678 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
679 || producesDeclared(DeviationStatement.class))) {
681 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
684 // FIXME: this does not look right, investigate more?
688 private @NonNull QName interpretAsQName(final String argument) {
689 // FIXME: This may yield illegal argument exceptions
690 return StmtContextUtils.qnameFromArgument(getOriginalCtx().orElse(this), argument);
695 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
696 // contribute to state visible outside of this package.
701 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
702 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
703 * knowledge and update it when {@link #sweep()} is invoked.
705 private byte parentRef = PARENTREF_UNKNOWN;
706 private static final byte PARENTREF_UNKNOWN = -1;
707 private static final byte PARENTREF_ABSENT = 0;
708 private static final byte PARENTREF_PRESENT = 1;
711 * Acquire a reference on this context. As long as there is at least one reference outstanding,
712 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
714 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
716 final void incRef() {
717 final int current = refcount;
718 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
719 if (current != REFCOUNT_DEFUNCT) {
720 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
721 refcount = current + 1;
723 LOG.debug("Disabled refcount increment of {}", this);
728 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
731 final void decRef() {
732 final int current = refcount;
733 if (current == REFCOUNT_DEFUNCT) {
735 LOG.debug("Disabled refcount decrement of {}", this);
738 if (current <= REFCOUNT_NONE) {
739 // Underflow, become defunct
740 // FIXME: add a global 'warn once' flag
741 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
742 refcount = REFCOUNT_DEFUNCT;
746 refcount = current - 1;
747 LOG.trace("Refcount {} on {}", refcount, this);
749 if (refcount == REFCOUNT_NONE) {
755 * Return {@code true} if this context has no outstanding references.
757 * @return True if this context has no outstanding references.
759 final boolean noRefs() {
760 final int local = refcount;
761 return local < REFCOUNT_NONE || local == REFCOUNT_NONE && noParentRef();
764 private void lastDecRef() {
765 if (noImplictRef()) {
766 // We are no longer guarded by effective instance
771 final byte prevRefs = parentRef;
772 if (prevRefs == PARENTREF_ABSENT) {
773 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
776 } else if (prevRefs == PARENTREF_UNKNOWN) {
777 // Noone observed our parentRef, just update it
778 loadParentRefcount();
782 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
783 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
784 final byte prevRef = stmt.parentRef;
785 stmt.parentRef = PARENTREF_ABSENT;
786 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
787 // Child thinks it is pinned down, update its perspective
788 stmt.markNoParentRef();
793 abstract void markNoParentRef();
795 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
796 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
802 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
804 private void sweep() {
805 parentRef = PARENTREF_ABSENT;
806 if (refcount == REFCOUNT_NONE && noImplictRef()) {
807 LOG.trace("Releasing {}", this);
812 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
814 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
815 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
823 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
824 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
828 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
830 * @return True if the entire tree has been completely swept, false otherwise.
832 abstract int sweepSubstatements();
834 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
835 private void sweepOnDecrement() {
836 LOG.trace("Sweeping on decrement {}", this);
838 // No further parent references, sweep our state.
842 // Propagate towards parent if there is one
843 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
844 if (parent != null) {
845 parent.sweepOnChildDecrement();
849 // Called from child when it has lost its final reference
850 private void sweepOnChildDecrement() {
851 if (isAwaitingChildren()) {
852 // We are a child for which our parent is waiting. Notify it and we are done.
857 // Check parent reference count
858 final int refs = refcount;
859 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
864 // parent is potentially reclaimable
866 LOG.trace("Cleanup {} of parent {}", refcount, this);
868 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
869 if (parent != null) {
870 parent.sweepOnChildDecrement();
876 private boolean noImplictRef() {
877 return effectiveInstance != null || !isSupportedToBuildEffective();
880 private boolean noParentRef() {
881 return parentRefcount() == PARENTREF_ABSENT;
884 private byte parentRefcount() {
886 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
889 private byte loadParentRefcount() {
890 return parentRef = calculateParentRefcount();
893 private byte calculateParentRefcount() {
894 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
895 if (parent == null) {
896 return PARENTREF_ABSENT;
898 // There are three possibilities:
899 // - REFCOUNT_NONE, in which case we need to search next parent
900 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
902 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
903 final int refs = parent.refcount;
904 if (refs == REFCOUNT_NONE) {
905 return parent.parentRefcount();
907 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
910 private boolean isAwaitingChildren() {
911 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
914 private void sweepOnChildDone() {
915 LOG.trace("Sweeping on child done {}", this);
916 final int current = refcount;
917 if (current >= REFCOUNT_NONE) {
918 // no-op, perhaps we want to handle some cases differently?
919 LOG.trace("Ignoring child sweep of {} for {}", this, current);
922 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
924 refcount = current + 1;
925 LOG.trace("Child refcount {}", refcount);
926 if (refcount == REFCOUNT_NONE) {
928 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
929 LOG.trace("Propagating to parent {}", parent);
930 if (parent != null && parent.isAwaitingChildren()) {
931 parent.sweepOnChildDone();
936 private void sweepDone() {
937 LOG.trace("Sweep done for {}", this);
938 refcount = REFCOUNT_SWEPT;
942 private boolean sweepState() {
943 refcount = REFCOUNT_SWEEPING;
944 final int childRefs = sweepSubstatements();
945 if (childRefs == 0) {
949 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
950 // FIXME: add a global 'warn once' flag
951 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
953 refcount = REFCOUNT_DEFUNCT;
955 LOG.trace("Still {} outstanding children of {}", childRefs, this);
956 refcount = -childRefs;