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.model.util;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static com.google.common.base.Preconditions.checkState;
12 import static java.util.Objects.requireNonNull;
14 import com.google.common.annotations.Beta;
15 import com.google.common.base.MoreObjects;
16 import com.google.common.collect.ImmutableList;
17 import java.util.ArrayDeque;
18 import java.util.Iterator;
19 import java.util.NoSuchElementException;
20 import org.eclipse.jdt.annotation.NonNull;
21 import org.eclipse.jdt.annotation.Nullable;
22 import org.opendaylight.yangtools.concepts.Mutable;
23 import org.opendaylight.yangtools.yang.common.QName;
24 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
25 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContextProvider;
26 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
27 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
28 import org.opendaylight.yangtools.yang.model.api.stmt.GroupingEffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.stmt.ModuleEffectiveStatement;
30 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
31 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaTreeAwareEffectiveStatement;
32 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaTreeEffectiveStatement;
35 * A state tracking utility for walking {@link EffectiveModelContext}'s contents along schema/grouping namespaces. This
36 * is conceptually a stack, tracking {@link EffectiveStatement}s encountered along traversal.
39 * This is meant to be a replacement concept for the use of {@link SchemaPath} in various places, notably
40 * in {@link SchemaContextUtil} methods.
43 * This class is designed for single-threaded uses and does not make any guarantees around concurrent access.
46 public final class SchemaInferenceStack implements Mutable, EffectiveModelContextProvider {
47 private final ArrayDeque<EffectiveStatement<QName, ?>> deque;
48 private final @NonNull EffectiveModelContext effectiveModel;
50 private @Nullable ModuleEffectiveStatement currentModule;
51 private int groupingDepth;
53 private SchemaInferenceStack(final SchemaInferenceStack source) {
54 this.deque = source.deque.clone();
55 this.effectiveModel = source.effectiveModel;
56 this.currentModule = source.currentModule;
57 this.groupingDepth = source.groupingDepth;
61 * Create a new empty stack backed by an effective model.
63 * @param effectiveModel EffectiveModelContext to which this stack is attached
64 * @throws NullPointerException {@code effectiveModel} is null
66 public SchemaInferenceStack(final EffectiveModelContext effectiveModel) {
67 this.deque = new ArrayDeque<>();
68 this.effectiveModel = requireNonNull(effectiveModel);
72 public EffectiveModelContext getEffectiveModelContext() {
73 return effectiveModel;
77 * Create a deep copy of this object.
79 * @return An isolated copy of this object
81 public @NonNull SchemaInferenceStack copy() {
82 return new SchemaInferenceStack(this);
86 * Check if this stack is empty.
88 * @return True if this stack has not entered any node.
90 public boolean isEmpty() {
91 return deque.isEmpty();
95 * Return the statement at the top of the stack.
97 * @return Top statement
98 * @throws IllegalStateException if the stack is empty
100 public @NonNull EffectiveStatement<QName, ?> currentStatement() {
101 return checkNonNullState(deque.peekFirst());
105 * Return current module the stack has entered.
107 * @return Current module
108 * @throws IllegalStateException if the stack is empty
110 public @NonNull ModuleEffectiveStatement currentModule() {
111 return checkNonNullState(currentModule);
115 * Check if the stack is in instantiated context. This indicates the stack is non-empty and there is no grouping
116 * (or similar construct) present in the stack.
118 * @return False if the stack is empty or contains a grouping, true otherwise.
120 public boolean inInstantiatedContext() {
121 return groupingDepth == 0 && !deque.isEmpty();
125 * Reset this stack to empty state.
127 public void clear() {
129 currentModule = null;
134 * Lookup a {@code grouping} by its node identifier and push it to the stack.
136 * @param nodeIdentifier Node identifier of the grouping to enter
137 * @return Resolved grouping
138 * @throws NullPointerException if {@code nodeIdentifier} is null
139 * @throws IllegalArgumentException if the corresponding grouping cannot be found
141 public @NonNull GroupingEffectiveStatement enterGrouping(final QName nodeIdentifier) {
142 return pushGrouping(requireNonNull(nodeIdentifier));
146 * Lookup a {@code schema tree} child by its node identifier and push it to the stack.
148 * @param nodeIdentifier Node identifier of the schema tree child to enter
149 * @return Resolved schema tree child
150 * @throws NullPointerException if {@code nodeIdentifier} is null
151 * @throws IllegalArgumentException if the corresponding child cannot be found
153 public @NonNull SchemaTreeEffectiveStatement<?> enterSchemaTree(final QName nodeIdentifier) {
154 return pushSchema(requireNonNull(nodeIdentifier));
158 * Pop the current statement from the stack.
160 * @return Previous statement
161 * @throws NoSuchElementException if this stack is empty
163 public @NonNull EffectiveStatement<QName, ?> exit() {
164 final EffectiveStatement<QName, ?> prev = deque.pop();
165 if (prev instanceof GroupingEffectiveStatement) {
168 if (deque.isEmpty()) {
169 currentModule = null;
175 * Convert current state into an absolute schema node identifier.
177 * @return Absolute schema node identifier representing current state
178 * @throws IllegalStateException if current state is not instantiated
180 public @NonNull Absolute toSchemaNodeIdentifier() {
181 checkState(inInstantiatedContext(), "Cannot convert uninstantiated context %s", this);
182 final ImmutableList.Builder<QName> builder = ImmutableList.builderWithExpectedSize(deque.size());
183 deque.descendingIterator().forEachRemaining(stmt -> builder.add(stmt.argument()));
184 return Absolute.of(builder.build());
188 * Convert current state into a SchemaPath.
190 * @return Absolute SchemaPath representing current state
191 * @throws IllegalStateException if current state is not instantiated
192 * @deprecated This method is meant only for interoperation with SchemaPath-based APIs.
195 public @NonNull SchemaPath toSchemaPath() {
196 SchemaPath ret = SchemaPath.ROOT;
197 final Iterator<EffectiveStatement<QName, ?>> it = deque.descendingIterator();
198 while (it.hasNext()) {
199 ret = ret.createChild(it.next().argument());
205 public String toString() {
206 return MoreObjects.toStringHelper(this).add("stack", deque).toString();
209 private @NonNull GroupingEffectiveStatement pushGrouping(final @NonNull QName nodeIdentifier) {
210 final EffectiveStatement<QName, ?> parent = deque.peekFirst();
211 return parent != null ? pushGrouping(parent, nodeIdentifier) : pushFirstGrouping(nodeIdentifier);
214 private @NonNull GroupingEffectiveStatement pushGrouping(final @NonNull EffectiveStatement<?, ?> parent,
215 final @NonNull QName nodeIdentifier) {
216 final GroupingEffectiveStatement ret = parent.streamEffectiveSubstatements(GroupingEffectiveStatement.class)
217 .filter(stmt -> nodeIdentifier.equals(stmt.argument()))
219 .orElseThrow(() -> new IllegalArgumentException("Grouping " + nodeIdentifier + " not present"));
225 private @NonNull GroupingEffectiveStatement pushFirstGrouping(final @NonNull QName nodeIdentifier) {
226 final ModuleEffectiveStatement module = getModule(nodeIdentifier);
227 final GroupingEffectiveStatement ret = pushGrouping(module, nodeIdentifier);
228 currentModule = module;
232 private @NonNull SchemaTreeEffectiveStatement<?> pushSchema(final @NonNull QName nodeIdentifier) {
233 final EffectiveStatement<QName, ?> parent = deque.peekFirst();
234 return parent != null ? pushSchema(parent, nodeIdentifier) : pushFirstSchema(nodeIdentifier);
237 private @NonNull SchemaTreeEffectiveStatement<?> pushSchema(final EffectiveStatement<QName, ?> parent,
238 final @NonNull QName nodeIdentifier) {
239 checkState(parent instanceof SchemaTreeAwareEffectiveStatement, "Cannot descend schema tree at %s", parent);
240 return pushSchema((SchemaTreeAwareEffectiveStatement<?, ?>) parent, nodeIdentifier);
243 private @NonNull SchemaTreeEffectiveStatement<?> pushSchema(
244 final @NonNull SchemaTreeAwareEffectiveStatement<?, ?> parent, final @NonNull QName nodeIdentifier) {
245 final SchemaTreeEffectiveStatement<?> ret = parent.findSchemaTreeNode(nodeIdentifier).orElseThrow(
246 () -> new IllegalArgumentException("Schema tree child " + nodeIdentifier + " not present"));
251 private @NonNull SchemaTreeEffectiveStatement<?> pushFirstSchema(final @NonNull QName nodeIdentifier) {
252 final ModuleEffectiveStatement module = getModule(nodeIdentifier);
253 final SchemaTreeEffectiveStatement<?> ret = pushSchema(module, nodeIdentifier);
254 currentModule = module;
258 private @NonNull ModuleEffectiveStatement getModule(final @NonNull QName nodeIdentifier) {
259 final ModuleEffectiveStatement module = effectiveModel.getModuleStatements().get(nodeIdentifier.getModule());
260 checkArgument(module != null, "Module for %s not found", nodeIdentifier);
264 private static <T> @NonNull T checkNonNullState(final @Nullable T obj) {
266 throw new IllegalStateException("Cannot execute on empty stack");