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 com.google.common.collect.Iterators;
18 import java.util.ArrayDeque;
19 import java.util.Iterator;
20 import java.util.NoSuchElementException;
21 import org.eclipse.jdt.annotation.NonNull;
22 import org.eclipse.jdt.annotation.Nullable;
23 import org.opendaylight.yangtools.concepts.Mutable;
24 import org.opendaylight.yangtools.yang.common.QName;
25 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
26 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContextProvider;
27 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
28 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.stmt.GroupingEffectiveStatement;
30 import org.opendaylight.yangtools.yang.model.api.stmt.ModuleEffectiveStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
32 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaTreeAwareEffectiveStatement;
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 * Create a new stack backed by an effective model, pointing to specified schema node identified by
75 * @param effectiveModel EffectiveModelContext to which this stack is attached
76 * @throws NullPointerException {@code effectiveModel} is null
77 * @throws IllegalArgumentException if {@code path} cannot be resolved in the effective model
79 public static @NonNull SchemaInferenceStack of(final EffectiveModelContext effectiveModel, final Absolute path) {
80 final SchemaInferenceStack ret = new SchemaInferenceStack(effectiveModel);
81 path.getNodeIdentifiers().forEach(ret::enterSchemaTree);
86 * Create a new stack backed by an effective model, pointing to specified schema node identified by an absolute
87 * {@link SchemaPath} and its {@link SchemaPath#getPathFromRoot()}.
89 * @param effectiveModel EffectiveModelContext to which this stack is attached
90 * @throws NullPointerException {@code effectiveModel} is null
91 * @throws IllegalArgumentException if {@code path} cannot be resolved in the effective model or if it is not an
94 // FIXME: 7.0.0: consider deprecating this method
95 public static @NonNull SchemaInferenceStack ofInstantiatedPath(final EffectiveModelContext effectiveModel,
96 final SchemaPath path) {
97 checkArgument(path.isAbsolute(), "Cannot operate on relative path %s", path);
98 final SchemaInferenceStack ret = new SchemaInferenceStack(effectiveModel);
99 path.getPathFromRoot().forEach(ret::enterSchemaTree);
104 public EffectiveModelContext getEffectiveModelContext() {
105 return effectiveModel;
109 * Create a deep copy of this object.
111 * @return An isolated copy of this object
113 public @NonNull SchemaInferenceStack copy() {
114 return new SchemaInferenceStack(this);
118 * Check if this stack is empty.
120 * @return True if this stack has not entered any node.
122 public boolean isEmpty() {
123 return deque.isEmpty();
127 * Return the statement at the top of the stack.
129 * @return Top statement
130 * @throws IllegalStateException if the stack is empty
132 public @NonNull EffectiveStatement<QName, ?> currentStatement() {
133 return checkNonNullState(deque.peekFirst());
137 * Return current module the stack has entered.
139 * @return Current module
140 * @throws IllegalStateException if the stack is empty
142 public @NonNull ModuleEffectiveStatement currentModule() {
143 return checkNonNullState(currentModule);
147 * Check if the stack is in instantiated context. This indicates the stack is non-empty and there is no grouping
148 * (or similar construct) present in the stack.
150 * @return False if the stack is empty or contains a grouping, true otherwise.
152 public boolean inInstantiatedContext() {
153 return groupingDepth == 0 && !deque.isEmpty();
157 * Reset this stack to empty state.
159 public void clear() {
161 currentModule = null;
166 * Lookup a grouping by its node identifier and push it to the stack.
168 * @param nodeIdentifier Node identifier of the grouping to enter
169 * @return Resolved grouping
170 * @throws NullPointerException if {@code nodeIdentifier} is null
171 * @throws IllegalArgumentException if the corresponding grouping cannot be found
173 public @NonNull GroupingEffectiveStatement enterGrouping(final QName nodeIdentifier) {
174 return pushGrouping(requireNonNull(nodeIdentifier));
178 * Lookup a schema tree child by its node identifier and push it to the stack.
180 * @param nodeIdentifier Node identifier of the schema tree child to enter
181 * @return Resolved schema tree child
182 * @throws NullPointerException if {@code nodeIdentifier} is null
183 * @throws IllegalArgumentException if the corresponding grouping cannot be found
185 public @NonNull EffectiveStatement<QName, ?> enterSchemaTree(final QName nodeIdentifier) {
186 return pushSchema(requireNonNull(nodeIdentifier));
190 * Pop the current statement from the stack.
192 * @return Previous statement
193 * @throws NoSuchElementException if this stack is empty
195 public @NonNull EffectiveStatement<QName, ?> exit() {
196 final EffectiveStatement<QName, ?> prev = deque.pop();
197 if (prev instanceof GroupingEffectiveStatement) {
200 if (deque.isEmpty()) {
201 currentModule = null;
207 * Convert current state into an absolute schema node identifier.
209 * @return Absolute schema node identifier representing current state
210 * @throws IllegalStateException if current state is not instantiated
212 public @NonNull Absolute toSchemaNodeIdentifier() {
213 checkState(inInstantiatedContext(), "Cannot convert uninstantiated context %s", this);
214 final ImmutableList.Builder<QName> builder = ImmutableList.builderWithExpectedSize(deque.size());
215 deque.descendingIterator().forEachRemaining(stmt -> builder.add(stmt.argument()));
216 return Absolute.of(builder.build());
220 * Convert current state into a SchemaPath.
222 * @return Absolute SchemaPath representing current state
223 * @throws IllegalStateException if current state is not instantiated
224 * @deprecated This method is meant only for interoperation with SchemaPath-based APIs.
227 public @NonNull SchemaPath toSchemaPath() {
228 SchemaPath ret = SchemaPath.ROOT;
229 final Iterator<EffectiveStatement<QName, ?>> it = deque.descendingIterator();
230 while (it.hasNext()) {
231 ret = ret.createChild(it.next().argument());
237 * Return an iterator along {@link SchemaPath#getPathFromRoot()}. This method is a faster equivalent of
238 * {@code toSchemaPath().getPathFromRoot().iterator()}.
240 * @return An unmodifiable iterator
243 public @NonNull Iterator<QName> schemaPathIterator() {
244 return Iterators.unmodifiableIterator(Iterators.transform(deque.descendingIterator(),
245 EffectiveStatement::argument));
249 public String toString() {
250 return MoreObjects.toStringHelper(this).add("stack", deque).toString();
253 private @NonNull GroupingEffectiveStatement pushGrouping(final @NonNull QName nodeIdentifier) {
254 final EffectiveStatement<QName, ?> parent = deque.peekFirst();
255 return parent != null ? pushGrouping(parent, nodeIdentifier) : pushFirstGrouping(nodeIdentifier);
258 private @NonNull GroupingEffectiveStatement pushGrouping(final @NonNull EffectiveStatement<?, ?> parent,
259 final @NonNull QName nodeIdentifier) {
260 final GroupingEffectiveStatement ret = parent.streamEffectiveSubstatements(GroupingEffectiveStatement.class)
261 .filter(stmt -> nodeIdentifier.equals(stmt.argument()))
263 .orElseThrow(() -> new IllegalArgumentException("Grouping " + nodeIdentifier + " not present"));
269 private @NonNull GroupingEffectiveStatement pushFirstGrouping(final @NonNull QName nodeIdentifier) {
270 final ModuleEffectiveStatement module = getModule(nodeIdentifier);
271 final GroupingEffectiveStatement ret = pushGrouping(module, nodeIdentifier);
272 currentModule = module;
276 private @NonNull EffectiveStatement<QName, ?> pushSchema(final @NonNull QName nodeIdentifier) {
277 final EffectiveStatement<QName, ?> parent = deque.peekFirst();
278 return parent != null ? pushSchema(parent, nodeIdentifier) : pushFirstSchema(nodeIdentifier);
281 private @NonNull EffectiveStatement<QName, ?> pushSchema(final EffectiveStatement<QName, ?> parent,
282 final @NonNull QName nodeIdentifier) {
283 checkState(parent instanceof SchemaTreeAwareEffectiveStatement, "Cannot descend schema tree at %s", parent);
284 return pushSchema((SchemaTreeAwareEffectiveStatement<?, ?>) parent, nodeIdentifier);
287 private @NonNull EffectiveStatement<QName, ?> pushSchema(
288 final @NonNull SchemaTreeAwareEffectiveStatement<?, ?> parent, final @NonNull QName nodeIdentifier) {
289 final EffectiveStatement<QName, ?> ret = parent.findSchemaTreeNode(nodeIdentifier).orElseThrow(
290 () -> new IllegalArgumentException("Schema tree child " + nodeIdentifier + " not present"));
295 private @NonNull EffectiveStatement<QName, ?> pushFirstSchema(final @NonNull QName nodeIdentifier) {
296 final ModuleEffectiveStatement module = getModule(nodeIdentifier);
297 final EffectiveStatement<QName, ?> ret = pushSchema(module, nodeIdentifier);
298 currentModule = module;
302 private @NonNull ModuleEffectiveStatement getModule(final @NonNull QName nodeIdentifier) {
303 final ModuleEffectiveStatement module = effectiveModel.getModuleStatements().get(nodeIdentifier.getModule());
304 checkArgument(module != null, "Module for %s not found", nodeIdentifier);
308 private static <T> @NonNull T checkNonNullState(final @Nullable T obj) {
310 throw new IllegalStateException("Cannot execute on empty stack");