X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=yang%2Fyang-parser-impl%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Fyang%2Fparser%2Fstmt%2Freactor%2FStatementContextBase.java;h=498894cc0a69d4f4e19f4485fbea87ed625737af;hb=30d51f4c77264c9b3904caf3a544d38345f7a462;hp=0f55001b5f2bdec373f003f9e39bcc659809b4cf;hpb=481a692d463636bbcf75f023da71703913e1b605;p=yangtools.git

diff --git a/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/StatementContextBase.java b/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/StatementContextBase.java
index 0f55001b5f..498894cc0a 100644
--- a/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/StatementContextBase.java
+++ b/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/reactor/StatementContextBase.java
@@ -7,209 +7,444 @@
  */
 package org.opendaylight.yangtools.yang.parser.stmt.reactor;
 
+import com.google.common.base.MoreObjects;
+import com.google.common.base.MoreObjects.ToStringHelper;
 import com.google.common.base.Preconditions;
-import com.google.common.base.Throwables;
-import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMultimap;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Multimap;
+import com.google.common.collect.Multimaps;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.EnumMap;
 import java.util.EventListener;
 import java.util.Iterator;
-import java.util.LinkedHashMap;
+import java.util.Optional;
+import java.util.Set;
 import javax.annotation.Nonnull;
-import org.opendaylight.yangtools.concepts.Identifiable;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.util.OptionalBoolean;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.common.QNameModule;
+import org.opendaylight.yangtools.yang.model.api.YangStmtMapping;
 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
 import org.opendaylight.yangtools.yang.model.api.meta.IdentifierNamespace;
 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
 import org.opendaylight.yangtools.yang.model.api.meta.StatementSource;
+import org.opendaylight.yangtools.yang.parser.spi.meta.CopyHistory;
+import org.opendaylight.yangtools.yang.parser.spi.meta.CopyType;
 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
 import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour;
-import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour.StorageNodeType;
 import org.opendaylight.yangtools.yang.parser.spi.meta.StatementNamespace;
+import org.opendaylight.yangtools.yang.parser.spi.meta.StatementSupport;
 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
+import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
+import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
+import org.opendaylight.yangtools.yang.parser.spi.source.ImplicitSubstatement;
 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
 import org.opendaylight.yangtools.yang.parser.spi.source.StatementSourceReference;
+import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace;
+import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace.SupportedFeatures;
 import org.opendaylight.yangtools.yang.parser.stmt.reactor.NamespaceBehaviourWithListeners.ValueAddedListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-public abstract class StatementContextBase<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>> extends
-        NamespaceStorageSupport implements StmtContext.Mutable<A, D, E>, Identifiable<StatementIdentifier> {
-
-    interface OnNamespaceItemAdded extends EventListener{
-
-        void namespaceItemAdded(StatementContextBase<?,?,?> context, Class<?> namespace, Object key, Object value) throws SourceException;
-
+public abstract class StatementContextBase<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
+        extends NamespaceStorageSupport implements Mutable<A, D, E> {
+    /**
+     * Event listener when an item is added to model namespace.
+     */
+    interface OnNamespaceItemAdded extends EventListener {
+        /**
+         * Invoked whenever a new item is added to a namespace.
+         */
+        void namespaceItemAdded(StatementContextBase<?, ?, ?> context, Class<?> namespace, Object key, Object value);
     }
 
-    interface OnPhaseFinished extends EventListener{
-
-        void phaseFinished(StatementContextBase<?,?,?> context, ModelProcessingPhase phase) throws SourceException;
-
+    /**
+     * Event listener when a parsing {@link ModelProcessingPhase} is completed.
+     */
+    interface OnPhaseFinished extends EventListener {
+        /**
+         * Invoked whenever a processing phase has finished.
+         */
+        boolean phaseFinished(StatementContextBase<?, ?, ?> context, ModelProcessingPhase phase);
     }
 
+    /**
+     * Interface for all mutations within an {@link ModelActionBuilder.InferenceAction}.
+     */
     interface ContextMutation {
 
         boolean isFinished();
-
     }
 
-    abstract static class ContextBuilder<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>> {
+    private static final Logger LOG = LoggerFactory.getLogger(StatementContextBase.class);
+
+    private final StatementDefinitionContext<A, D, E> definition;
+    private final StatementSourceReference statementDeclSource;
+    private final StmtContext<?, ?, ?> originalCtx;
+    private final CopyHistory copyHistory;
+    private final String rawArgument;
+
+    private Multimap<ModelProcessingPhase, OnPhaseFinished> phaseListeners = ImmutableMultimap.of();
+    private Multimap<ModelProcessingPhase, ContextMutation> phaseMutation = ImmutableMultimap.of();
+    private Collection<Mutable<?, ?, ?>> effective = ImmutableList.of();
+    private Collection<StmtContext<?, ?, ?>> effectOfStatement = ImmutableList.of();
+    private StatementMap substatements = StatementMap.empty();
+
+    private boolean isSupportedToBuildEffective = true;
+    private ModelProcessingPhase completedPhase = null;
+    private D declaredInstance;
+    private E effectiveInstance;
 
-        private final StatementDefinitionContext<A, D, E> definition;
-        private final StatementSourceReference stmtRef;
-        private String rawArg;
-        private StatementSourceReference argRef;
+    // BooleanFields value
+    private byte supportedByFeatures;
 
-        public ContextBuilder(StatementDefinitionContext<A, D, E> def, StatementSourceReference sourceRef) {
-            this.definition = def;
-            this.stmtRef = sourceRef;
-        }
+    StatementContextBase(final StatementDefinitionContext<A, D, E> def, final StatementSourceReference ref,
+            final String rawArgument) {
+        this.definition = Preconditions.checkNotNull(def);
+        this.statementDeclSource = Preconditions.checkNotNull(ref);
+        this.rawArgument = def.internArgument(rawArgument);
+        this.copyHistory = CopyHistory.original();
+        this.originalCtx = null;
+    }
 
-        public void setArgument(@Nonnull String argument, @Nonnull StatementSourceReference argumentSource) {
-            Preconditions.checkArgument(definition.hasArgument(), "Statement does not take argument.");
-            this.rawArg = Preconditions.checkNotNull(argument);
-            this.argRef = Preconditions.checkNotNull(argumentSource);
-        }
+    StatementContextBase(final StatementContextBase<A, D, E> original, final CopyType copyType) {
+        this.definition = Preconditions.checkNotNull(original.definition,
+                "Statement context definition cannot be null copying from: %s", original.getStatementSourceReference());
+        this.statementDeclSource = Preconditions.checkNotNull(original.statementDeclSource,
+                "Statement context statementDeclSource cannot be null copying from: %s",
+                original.getStatementSourceReference());
+        this.rawArgument = original.rawArgument;
+        this.copyHistory = CopyHistory.of(copyType, original.getCopyHistory());
+        this.originalCtx = original.getOriginalCtx().orElse(original);
+    }
+
+    @Override
+    public Collection<? extends StmtContext<?, ?, ?>> getEffectOfStatement() {
+        return effectOfStatement;
+    }
 
-        public String getRawArgument() {
-            return rawArg;
+    @Override
+    public void addAsEffectOfStatement(final StmtContext<?, ?, ?> ctx) {
+        if (effectOfStatement.isEmpty()) {
+            effectOfStatement = new ArrayList<>(1);
         }
+        effectOfStatement.add(ctx);
+    }
 
-        public StatementSourceReference getStamementSource() {
-            return stmtRef;
+    @Override
+    public void addAsEffectOfStatement(final Collection<? extends StmtContext<?, ?, ?>> ctxs) {
+        if (ctxs.isEmpty()) {
+            return;
         }
 
-        public StatementSourceReference getArgumentSource() {
-            return argRef;
+        if (effectOfStatement.isEmpty()) {
+            effectOfStatement = new ArrayList<>(ctxs.size());
         }
+        effectOfStatement.addAll(ctxs);
+    }
 
-        public StatementDefinitionContext<A, D, E> getDefinition() {
-            return definition;
+    @Override
+    public boolean isSupportedByFeatures() {
+        if (OptionalBoolean.isPresent(supportedByFeatures)) {
+            return OptionalBoolean.get(supportedByFeatures);
         }
 
-        public StatementIdentifier getIdentifier() {
-            return new StatementIdentifier(definition.getStatementName(), rawArg);
+        if (isIgnoringIfFeatures()) {
+            supportedByFeatures = OptionalBoolean.of(true);
+            return true;
         }
 
-        public abstract StatementContextBase<A, D, E> build() throws SourceException;
+        final boolean isParentSupported = isParentSupportedByFeatures();
+        /*
+         * If parent is not supported, then this context is also not supported.
+         * So we do not need to check if-features statements of this context and
+         * we can return false immediately.
+         */
+        if (!isParentSupported) {
+            supportedByFeatures = OptionalBoolean.of(false);
+            return false;
+        }
 
+        /*
+         * If parent is supported, we need to check if-features statements of
+         * this context.
+         */
+        // If the set of supported features has not been provided, all features are supported by default.
+        final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
+                SupportedFeatures.SUPPORTED_FEATURES);
+        final boolean ret = supportedFeatures == null ? true
+                : StmtContextUtils.checkFeatureSupport(this, supportedFeatures);
+
+        supportedByFeatures = OptionalBoolean.of(ret);
+        return ret;
     }
 
-    private final StatementDefinitionContext<A, D, E> definition;
-    private final StatementIdentifier identifier;
-    private final StatementSourceReference statementDeclSource;
+    protected abstract boolean isParentSupportedByFeatures();
 
-    private LinkedHashMap<StatementIdentifier, StatementContextBase<?, ?, ?> > substatements = new LinkedHashMap<>();
+    protected abstract boolean isIgnoringIfFeatures();
 
-    private Collection<StatementContextBase<?, ?, ?>> declared = new ArrayList<>();
-    private Collection<StatementContextBase<?, ?, ?>> effective = new ArrayList<>();
+    protected abstract boolean isIgnoringConfig();
 
-    private ModelProcessingPhase completedPhase;
+    @Override
+    public boolean isSupportedToBuildEffective() {
+        return isSupportedToBuildEffective;
+    }
 
-    private Multimap<ModelProcessingPhase,OnPhaseFinished> phaseListeners = HashMultimap.create();
-    private Multimap<ModelProcessingPhase, ContextMutation> phaseMutation = HashMultimap.create();
+    @Override
+    public void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
+        this.isSupportedToBuildEffective = isSupportedToBuildEffective;
+    }
 
-    private D declaredInstance;
-    private E effectiveInstance;
+    @Override
+    public CopyHistory getCopyHistory() {
+        return copyHistory;
+    }
 
+    @Override
+    public Optional<StmtContext<?, ?, ?>> getOriginalCtx() {
+        return Optional.ofNullable(originalCtx);
+    }
 
-    StatementContextBase(@Nonnull ContextBuilder<A, D, E> builder) throws SourceException {
-        this.definition = builder.getDefinition();
-        this.identifier = builder.getIdentifier();
-        this.statementDeclSource = builder.getStamementSource();
-        this.completedPhase = null;
+    @Override
+    public ModelProcessingPhase getCompletedPhase() {
+        return completedPhase;
     }
 
-    StatementContextBase(StatementContextBase<A,D,E> original) {
-        this.definition = original.definition;
-        this.identifier = original.identifier;
-        this.statementDeclSource = original.statementDeclSource;
-        this.completedPhase = null;
+    @Override
+    public void setCompletedPhase(final ModelProcessingPhase completedPhase) {
+        this.completedPhase = completedPhase;
     }
 
     @Override
     public abstract StatementContextBase<?, ?, ?> getParentContext();
 
+    /**
+     * Returns the model root for this statement.
+     *
+     * @return root context of statement
+     */
+    @Nonnull
     @Override
     public abstract RootStatementContext<?, ?, ?> getRoot();
 
-
-    @Override
-    public StatementIdentifier getIdentifier() {
-        return identifier;
-    }
-
+    /**
+     * Returns the origin of the statement.
+     *
+     * @return origin of statement
+     */
+    @Nonnull
     @Override
     public StatementSource getStatementSource() {
         return statementDeclSource.getStatementSource();
     }
 
+    /**
+     * Returns a reference to statement source.
+     *
+     * @return reference of statement source
+     */
+    @Nonnull
     @Override
     public StatementSourceReference getStatementSourceReference() {
         return statementDeclSource;
     }
 
     @Override
-    public String rawStatementArgument() {
-        return identifier.getArgument();
+    public final String rawStatementArgument() {
+        return rawArgument;
+    }
+
+    @Nonnull
+    @Override
+    public Collection<? extends StmtContext<?, ?, ?>> declaredSubstatements() {
+        return substatements.values();
+    }
+
+    @Nonnull
+    @Override
+    public Collection<? extends Mutable<?, ?, ?>> mutableDeclaredSubstatements() {
+        return substatements.values();
     }
 
     @Override
-    public Collection<StatementContextBase<?, ?, ?>> declaredSubstatements() {
-        return Collections.unmodifiableCollection(declared);
+    public Collection<? extends StmtContext<?, ?, ?>> effectiveSubstatements() {
+        return mutableEffectiveSubstatements();
     }
 
+    @Nonnull
     @Override
-    public Collection<StatementContextBase<?, ?, ?>> effectiveSubstatements() {
+    public Collection<? extends Mutable<?, ?, ?>> mutableEffectiveSubstatements() {
+        if (effective instanceof ImmutableCollection) {
+            return effective;
+        }
+
         return Collections.unmodifiableCollection(effective);
     }
 
-    public void addEffectiveSubstatement(StatementContextBase<?, ?, ?> substatement){
-        effective.add(substatement);
+    public void removeStatementsFromEffectiveSubstatements(
+            final Collection<? extends StmtContext<?, ?, ?>> substatements) {
+        if (!effective.isEmpty()) {
+            effective.removeAll(substatements);
+            shrinkEffective();
+        }
     }
 
-    public void addDeclaredSubstatement(StatementContextBase<?, ?, ?> substatement){
-        declared.add(substatement);
+    private void shrinkEffective() {
+        if (effective.isEmpty()) {
+            effective = ImmutableList.of();
+        }
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
-    public ContextBuilder<?, ?, ?> substatementBuilder(StatementDefinitionContext<?, ?, ?> def,
-            StatementSourceReference ref) {
-        return new ContextBuilder(def, ref) {
+    public void removeStatementFromEffectiveSubstatements(final StatementDefinition statementDef) {
+        if (effective.isEmpty()) {
+            return;
+        }
 
-            @Override
-            public StatementContextBase build() throws SourceException {
-                StatementContextBase<?, ?, ?> potential = substatements.get(getIdentifier());
-                if(potential == null) {
-                    potential = new SubstatementContext(StatementContextBase.this, this);
-                    substatements.put(getIdentifier(), potential);
-                }
-                potential.resetLists();
-                switch (this.getStamementSource().getStatementSource()) {
-                    case DECLARATION:
-                        declared.add(potential);
-                        break;
-                    case CONTEXT:
-                        effective.add(potential);
-                        break;
-                }
-                return potential;
+        final Iterator<? extends StmtContext<?, ?, ?>> iterator = effective.iterator();
+        while (iterator.hasNext()) {
+            final StmtContext<?, ?, ?> next = iterator.next();
+            if (statementDef.equals(next.getPublicDefinition())) {
+                iterator.remove();
+            }
+        }
+
+        shrinkEffective();
+    }
+
+    /**
+     * Removes a statement context from the effective substatements based on its statement definition (i.e statement
+     * keyword) and raw (in String form) statement argument. The statement context is removed only if both statement
+     * definition and statement argument match with one of the effective substatements' statement definition
+     * and argument.
+     *
+     * <p>
+     * If the statementArg parameter is null, the statement context is removed based only on its statement definition.
+     *
+     * @param statementDef statement definition of the statement context to remove
+     * @param statementArg statement argument of the statement context to remove
+     */
+    public void removeStatementFromEffectiveSubstatements(final StatementDefinition statementDef,
+            final String statementArg) {
+        if (statementArg == null) {
+            removeStatementFromEffectiveSubstatements(statementDef);
+        }
+
+        if (effective.isEmpty()) {
+            return;
+        }
+
+        final Iterator<Mutable<?, ?, ?>> iterator = effective.iterator();
+        while (iterator.hasNext()) {
+            final Mutable<?, ?, ?> next = iterator.next();
+            if (statementDef.equals(next.getPublicDefinition()) && statementArg.equals(next.rawStatementArgument())) {
+                iterator.remove();
             }
-        };
+        }
+
+        shrinkEffective();
     }
 
+    /**
+     * Adds an effective statement to collection of substatements.
+     *
+     * @param substatement substatement
+     * @throws IllegalStateException
+     *             if added in declared phase
+     * @throws NullPointerException
+     *             if statement parameter is null
+     */
+    public void addEffectiveSubstatement(final Mutable<?, ?, ?> substatement) {
+        beforeAddEffectiveStatement(1);
+        effective.add(substatement);
+    }
 
+    /**
+     * Adds an effective statement to collection of substatements.
+     *
+     * @param substatements substatements
+     * @throws IllegalStateException
+     *             if added in declared phase
+     * @throws NullPointerException
+     *             if statement parameter is null
+     */
+    public void addEffectiveSubstatements(final Collection<? extends Mutable<?, ?, ?>> substatements) {
+        if (substatements.isEmpty()) {
+            return;
+        }
 
-    @Override
-    public StorageNodeType getStorageNodeType() {
-        return StorageNodeType.STATEMENT_LOCAL;
+        substatements.forEach(Preconditions::checkNotNull);
+        beforeAddEffectiveStatement(substatements.size());
+        effective.addAll(substatements);
+    }
+
+    private void beforeAddEffectiveStatement(final int toAdd) {
+        final ModelProcessingPhase inProgressPhase = getRoot().getSourceContext().getInProgressPhase();
+        Preconditions.checkState(inProgressPhase == ModelProcessingPhase.FULL_DECLARATION
+                || inProgressPhase == ModelProcessingPhase.EFFECTIVE_MODEL,
+                "Effective statement cannot be added in declared phase at: %s", getStatementSourceReference());
+
+        if (effective.isEmpty()) {
+            effective = new ArrayList<>(toAdd);
+        }
+    }
+
+    /**
+     * Create a new substatement at the specified offset.
+     *
+     * @param offset Substatement offset
+     * @param def definition context
+     * @param ref source reference
+     * @param argument statement argument
+     * @return A new substatement
+     */
+    public final <CA, CD extends DeclaredStatement<CA>, CE extends EffectiveStatement<CA, CD>>
+            StatementContextBase<CA, CD, CE> createSubstatement(final int offset,
+                    final StatementDefinitionContext<CA, CD, CE> def, final StatementSourceReference ref,
+                    final String argument) {
+        final ModelProcessingPhase inProgressPhase = getRoot().getSourceContext().getInProgressPhase();
+        Preconditions.checkState(inProgressPhase != ModelProcessingPhase.EFFECTIVE_MODEL,
+                "Declared statement cannot be added in effective phase at: %s", getStatementSourceReference());
+
+        final Optional<StatementSupport<?, ?, ?>> implicitParent = definition.getImplicitParentFor(def.getPublicView());
+        if (implicitParent.isPresent()) {
+            return createImplicitParent(offset, implicitParent.get(), ref, argument).createSubstatement(offset, def,
+                    ref, argument);
+        }
+
+        final StatementContextBase<CA, CD, CE> ret = new SubstatementContext<>(this, def, ref, argument);
+        substatements = substatements.put(offset, ret);
+        def.onStatementAdded(ret);
+        return ret;
+    }
+
+    private StatementContextBase<?, ?, ?> createImplicitParent(final int offset,
+            final StatementSupport<?, ?, ?> implicitParent, final StatementSourceReference ref, final String argument) {
+        final StatementDefinitionContext<?, ?, ?> def = new StatementDefinitionContext<>(implicitParent);
+        return createSubstatement(offset, def, ImplicitSubstatement.of(ref), argument);
+    }
+
+    /**
+     * Lookup substatement by its offset in this statement.
+     *
+     * @param offset Substatement offset
+     * @return Substatement, or null if substatement does not exist.
+     */
+    final StatementContextBase<?, ?, ?> lookupSubstatement(final int offset) {
+        return substatements.get(offset);
     }
 
     @Override
     public D buildDeclared() {
-        Preconditions.checkArgument(completedPhase == ModelProcessingPhase.FULL_DECLARATION || completedPhase == ModelProcessingPhase.EFFECTIVE_MODEL);
+        Preconditions.checkArgument(completedPhase == ModelProcessingPhase.FULL_DECLARATION
+                || completedPhase == ModelProcessingPhase.EFFECTIVE_MODEL);
         if (declaredInstance == null) {
             declaredInstance = definition().getFactory().createDeclared(this);
         }
@@ -218,139 +453,291 @@ public abstract class StatementContextBase<A, D extends DeclaredStatement<A>, E
 
     @Override
     public E buildEffective() {
-        Preconditions.checkArgument(completedPhase == ModelProcessingPhase.EFFECTIVE_MODEL);
         if (effectiveInstance == null) {
             effectiveInstance = definition().getFactory().createEffective(this);
         }
         return effectiveInstance;
     }
 
+    /**
+     * tries to execute current {@link ModelProcessingPhase} of source parsing.
+     *
+     * @param phase
+     *            to be executed (completed)
+     * @return if phase was successfully completed
+     * @throws SourceException
+     *             when an error occured in source parsing
+     */
+    boolean tryToCompletePhase(final ModelProcessingPhase phase) {
 
-    void resetLists() {
-        declared.clear();
-    }
-
-    boolean tryToCompletePhase(ModelProcessingPhase phase) throws SourceException {
-        if(phase.equals(completedPhase)) {
-            return true;
-        }
-        Iterator<ContextMutation> openMutations = phaseMutation.get(phase).iterator();
         boolean finished = true;
-        while(openMutations.hasNext()) {
-            ContextMutation current = openMutations.next();
-            if(current.isFinished()) {
-                openMutations.remove();
-            } else {
-                finished = false;
+        final Collection<ContextMutation> openMutations = phaseMutation.get(phase);
+        if (!openMutations.isEmpty()) {
+            final Iterator<ContextMutation> it = openMutations.iterator();
+            while (it.hasNext()) {
+                final ContextMutation current = it.next();
+                if (current.isFinished()) {
+                    it.remove();
+                } else {
+                    finished = false;
+                }
+            }
+
+            if (openMutations.isEmpty()) {
+                phaseMutation.removeAll(phase);
+                if (phaseMutation.isEmpty()) {
+                    phaseMutation = ImmutableMultimap.of();
+                }
             }
         }
-        for(StatementContextBase<?, ?, ?> child: declared) {
+
+        for (final StatementContextBase<?, ?, ?> child : substatements.values()) {
             finished &= child.tryToCompletePhase(phase);
         }
-        for(StatementContextBase<?, ?, ?> child: effective) {
-            finished &= child.tryToCompletePhase(phase);
+        for (final Mutable<?, ?, ?> child : effective) {
+            if (child instanceof StatementContextBase) {
+                finished &= ((StatementContextBase<?, ?, ?>) child).tryToCompletePhase(phase);
+            }
         }
-        if(finished) {
+
+        if (finished) {
             onPhaseCompleted(phase);
             return true;
         }
         return false;
     }
 
-
-    private void onPhaseCompleted(ModelProcessingPhase phase) throws SourceException {
+    /**
+     * Occurs on end of {@link ModelProcessingPhase} of source parsing.
+     *
+     * @param phase
+     *            that was to be completed (finished)
+     * @throws SourceException
+     *             when an error occurred in source parsing
+     */
+    private void onPhaseCompleted(final ModelProcessingPhase phase) {
         completedPhase = phase;
-        Iterator<OnPhaseFinished> listener = phaseListeners.get(completedPhase).iterator();
-        while(listener.hasNext()) {
-            listener.next().phaseFinished(this, phase);
-            listener.remove();
+
+        final Collection<OnPhaseFinished> listeners = phaseListeners.get(phase);
+        if (listeners.isEmpty()) {
+            return;
+        }
+
+        final Iterator<OnPhaseFinished> listener = listeners.iterator();
+        while (listener.hasNext()) {
+            final OnPhaseFinished next = listener.next();
+            if (next.phaseFinished(this, phase)) {
+                listener.remove();
+            }
+        }
+
+        if (listeners.isEmpty()) {
+            phaseListeners.removeAll(phase);
+            if (phaseListeners.isEmpty()) {
+                phaseListeners = ImmutableMultimap.of();
+            }
         }
     }
 
     /**
-     *
      * Ends declared section of current node.
-     *
-     * @param ref
-     * @throws SourceException
-     *
      */
-    void endDeclared(StatementSourceReference ref,ModelProcessingPhase phase) throws SourceException {
-        definition().onDeclarationFinished(this,phase);
+    void endDeclared(final StatementSourceReference ref, final ModelProcessingPhase phase) {
+        definition().onDeclarationFinished(this, phase);
     }
 
+    /**
+     * Return the context in which this statement was defined.
+     *
+     * @return statement definition
+     */
     protected final StatementDefinitionContext<A, D, E> definition() {
         return definition;
     }
 
     @Override
-    protected void checkLocalNamespaceAllowed(Class<? extends IdentifierNamespace<?, ?>> type) {
+    protected void checkLocalNamespaceAllowed(final Class<? extends IdentifierNamespace<?, ?>> type) {
         definition().checkNamespaceAllowed(type);
     }
 
     @Override
-    protected <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceElementAdded(Class<N> type, K key, V value) {
-        //definition().onNamespaceElementAdded(this, type, key, value);
+    protected <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
+            final V value) {
+        // definition().onNamespaceElementAdded(this, type, key, value);
     }
 
-    <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceItemAddedAction(final Class<N> type, K key, final OnNamespaceItemAdded listener) throws SourceException {
-        Object potential = getFromNamespace(type, key);
-        if(potential != null) {
+    <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceItemAddedAction(final Class<N> type, final K key,
+            final OnNamespaceItemAdded listener) throws SourceException {
+        final Object potential = getFromNamespace(type, key);
+        if (potential != null) {
+            LOG.trace("Listener on {} key {} satisfied immediately", type, key);
             listener.namespaceItemAdded(this, type, key, potential);
             return;
         }
-        NamespaceBehaviour<K,V,N> behaviour = getBehaviourRegistry().getNamespaceBehaviour(type);
-        if(behaviour instanceof NamespaceBehaviourWithListeners) {
-            NamespaceBehaviourWithListeners<K, V, N> casted = (NamespaceBehaviourWithListeners<K,V,N>) behaviour;
-            casted.addValueListener(key, new ValueAddedListener(this) {
-                @Override
-                void onValueAdded(Object key, Object value) {
-                    try {
-                        listener.namespaceItemAdded(StatementContextBase.this, type, key, value);
-                    } catch (SourceException e) {
-                        throw Throwables.propagate(e);
-                    }
-                }
-            });
-        }
+
+        final NamespaceBehaviour<K, V, N> behaviour = getBehaviourRegistry().getNamespaceBehaviour(type);
+        Preconditions.checkArgument(behaviour instanceof NamespaceBehaviourWithListeners,
+            "Namespace {} does not support listeners", type);
+
+        final NamespaceBehaviourWithListeners<K, V, N> casted = (NamespaceBehaviourWithListeners<K, V, N>) behaviour;
+        casted.addValueListener(new ValueAddedListener<K>(this, key) {
+            @Override
+            void onValueAdded(final Object key, final Object value) {
+                listener.namespaceItemAdded(StatementContextBase.this, type, key, value);
+            }
+        });
     }
 
+    /**
+     * See {@link StatementSupport#getPublicView()}.
+     */
+    @Nonnull
     @Override
     public StatementDefinition getPublicDefinition() {
         return definition().getPublicView();
     }
 
     @Override
-    public ModelActionBuilder newInferenceAction(ModelProcessingPhase phase) {
+    public ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
         return getRoot().getSourceContext().newInferenceAction(phase);
     }
 
-    void addPhaseCompletedListener(ModelProcessingPhase phase, OnPhaseFinished listener) throws SourceException {
+    private static <T> Multimap<ModelProcessingPhase, T> newMultimap() {
+        return Multimaps.newListMultimap(new EnumMap<>(ModelProcessingPhase.class), () -> new ArrayList<>(1));
+    }
+
+    /**
+     * Adds {@link OnPhaseFinished} listener for a {@link ModelProcessingPhase} end.
+     */
+    void addPhaseCompletedListener(final ModelProcessingPhase phase, final OnPhaseFinished listener) {
+        Preconditions.checkNotNull(phase, "Statement context processing phase cannot be null at: %s",
+                getStatementSourceReference());
+        Preconditions.checkNotNull(listener, "Statement context phase listener cannot be null at: %s",
+                getStatementSourceReference());
+
         ModelProcessingPhase finishedPhase = completedPhase;
         while (finishedPhase != null) {
-            if(phase.equals(finishedPhase)) {
+            if (phase.equals(finishedPhase)) {
                 listener.phaseFinished(this, finishedPhase);
                 return;
             }
             finishedPhase = finishedPhase.getPreviousPhase();
         }
+        if (phaseListeners.isEmpty()) {
+            phaseListeners = newMultimap();
+        }
+
         phaseListeners.put(phase, listener);
     }
 
-    void addMutation(ModelProcessingPhase phase, ContextMutation mutation) {
+    /**
+     * Adds a {@link ContextMutation} to a {@link ModelProcessingPhase}.
+     *
+     * @throws IllegalStateException
+     *             when the mutation was registered after phase was completed
+     */
+    void addMutation(final ModelProcessingPhase phase, final ContextMutation mutation) {
         ModelProcessingPhase finishedPhase = completedPhase;
         while (finishedPhase != null) {
-            if(phase.equals(finishedPhase)) {
-                throw new IllegalStateException("Mutation registered after phase was completed.");
-            }
+            Preconditions.checkState(!phase.equals(finishedPhase),
+                "Mutation registered after phase was completed at: %s", getStatementSourceReference());
             finishedPhase = finishedPhase.getPreviousPhase();
         }
+
+        if (phaseMutation.isEmpty()) {
+            phaseMutation = newMultimap();
+        }
         phaseMutation.put(phase, mutation);
     }
 
     @Override
-    public <K,KT extends K, N extends StatementNamespace<K, ?, ?>> void addContext(
-            Class<N> namepsace, KT key, StmtContext<?, ?, ?> stmt) {
-        addContextToNamespace(namepsace,(K) key, stmt);
+    public <K, KT extends K, N extends StatementNamespace<K, ?, ?>> void addContext(final Class<N> namespace,
+            final KT key,final StmtContext<?, ?, ?> stmt) {
+        addContextToNamespace(namespace, key, stmt);
+    }
+
+    @Override
+    public <X, Y extends DeclaredStatement<X>, Z extends EffectiveStatement<X, Y>> Mutable<X, Y, Z> childCopyOf(
+            final StmtContext<X, Y, Z> stmt, final CopyType type, final QNameModule targetModule) {
+        Preconditions.checkState(stmt.getCompletedPhase() == ModelProcessingPhase.EFFECTIVE_MODEL,
+                "Attempted to copy statement %s which has completed phase %s", stmt, stmt.getCompletedPhase());
+
+        Preconditions.checkArgument(stmt instanceof SubstatementContext, "Unsupported statement %s", stmt);
+
+        final SubstatementContext<X, Y, Z> original = (SubstatementContext<X, Y, Z>)stmt;
+        final SubstatementContext<X, Y, Z> copy = new SubstatementContext<>(original, this, type, targetModule);
+
+        original.definition().onStatementAdded(copy);
+        original.copyTo(copy, type, targetModule);
+
+        return copy;
+    }
+
+    final void copyTo(final StatementContextBase<?, ?, ?> target, final CopyType typeOfCopy,
+            @Nullable final QNameModule targetModule) {
+        final Collection<Mutable<?, ?, ?>> buffer = new ArrayList<>(substatements.size() + effective.size());
+
+        for (final Mutable<?, ?, ?> stmtContext : substatements.values()) {
+            if (stmtContext.isSupportedByFeatures()) {
+                copySubstatement(stmtContext, target, typeOfCopy, targetModule, buffer);
+            }
+        }
+
+        for (final Mutable<?, ?, ?> stmtContext : effective) {
+            copySubstatement(stmtContext, target, typeOfCopy, targetModule, buffer);
+        }
+
+        target.addEffectiveSubstatements(buffer);
+    }
+
+    private void copySubstatement(final Mutable<?, ?, ?> stmtContext,  final Mutable<?, ?, ?> target,
+            final CopyType typeOfCopy, final QNameModule newQNameModule, final Collection<Mutable<?, ?, ?>> buffer) {
+        if (needToCopyByUses(stmtContext)) {
+            final Mutable<?, ?, ?> copy = target.childCopyOf(stmtContext, typeOfCopy, newQNameModule);
+            LOG.debug("Copying substatement {} for {} as", stmtContext, this, copy);
+            buffer.add(copy);
+        } else if (isReusedByUses(stmtContext)) {
+            LOG.debug("Reusing substatement {} for {}", stmtContext, this);
+            buffer.add(stmtContext);
+        } else {
+            LOG.debug("Skipping statement {}", stmtContext);
+        }
+    }
+
+    // FIXME: revise this, as it seems to be wrong
+    private static final Set<YangStmtMapping> NOCOPY_FROM_GROUPING_SET = ImmutableSet.of(
+        YangStmtMapping.DESCRIPTION,
+        YangStmtMapping.REFERENCE,
+        YangStmtMapping.STATUS);
+    private static final Set<YangStmtMapping> REUSED_DEF_SET = ImmutableSet.of(
+        YangStmtMapping.TYPE,
+        YangStmtMapping.TYPEDEF,
+        YangStmtMapping.USES);
+
+    private static boolean needToCopyByUses(final StmtContext<?, ?, ?> stmtContext) {
+        final StatementDefinition def = stmtContext.getPublicDefinition();
+        if (REUSED_DEF_SET.contains(def)) {
+            LOG.debug("Will reuse {} statement {}", def, stmtContext);
+            return false;
+        }
+        if (NOCOPY_FROM_GROUPING_SET.contains(def)) {
+            return !YangStmtMapping.GROUPING.equals(stmtContext.getParentContext().getPublicDefinition());
+        }
+
+        LOG.debug("Will copy {} statement {}", def, stmtContext);
+        return true;
+    }
+
+    private static boolean isReusedByUses(final StmtContext<?, ?, ?> stmtContext) {
+        return REUSED_DEF_SET.contains(stmtContext.getPublicDefinition());
+    }
+
+    @Override
+    public final String toString() {
+        return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
+    }
+
+    protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
+        return toStringHelper.add("definition", definition).add("rawArgument", rawArgument);
     }
 }