2 * Copyright © 2020 FRINX s.r.o. and others. All rights reserved.
3 * Copyright © 2021 PANTHEON.tech, s.r.o.
5 * This program and the accompanying materials are made available under the
6 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
7 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.restconf.nb.rfc8040.utils.parser;
11 import static java.util.Objects.requireNonNull;
13 import java.util.ArrayList;
14 import java.util.HashSet;
15 import java.util.LinkedList;
16 import java.util.List;
18 import org.eclipse.jdt.annotation.NonNull;
19 import org.eclipse.jdt.annotation.Nullable;
20 import org.opendaylight.netconf.dom.api.NetconfDataTreeService;
21 import org.opendaylight.restconf.api.query.FieldsParam;
22 import org.opendaylight.restconf.api.query.FieldsParam.NodeSelector;
23 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
24 import org.opendaylight.yangtools.yang.common.Empty;
25 import org.opendaylight.yangtools.yang.common.ErrorTag;
26 import org.opendaylight.yangtools.yang.common.ErrorType;
27 import org.opendaylight.yangtools.yang.common.QName;
28 import org.opendaylight.yangtools.yang.common.QNameModule;
29 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
30 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
31 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
33 import org.opendaylight.yangtools.yang.data.util.DataSchemaContext;
34 import org.opendaylight.yangtools.yang.data.util.DataSchemaContext.PathMixin;
35 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
36 import org.opendaylight.yangtools.yang.model.api.LeafListSchemaNode;
37 import org.opendaylight.yangtools.yang.model.api.ListSchemaNode;
40 * A translator between {@link FieldsParam} and {@link YangInstanceIdentifier}s suitable for use as field identifiers
41 * in {@code netconf-dom-api}.
44 * Fields parser that stores a set of all the leaf {@link LinkedPathElement}s specified in {@link FieldsParam}.
45 * Using {@link LinkedPathElement} it is possible to create a chain of path arguments and build complete paths
46 * since this element contains identifiers of intermediary mixin nodes and also linked to its parent
47 * {@link LinkedPathElement}.
50 * Example: field 'a(b/c;d/e)' ('e' is place under choice node 'x') is parsed into following levels:
52 * - './a' +- 'a/b' - 'b/c'
57 public final class NetconfFieldsTranslator {
59 * {@link DataSchemaContext} of data element grouped with identifiers of leading mixin nodes and previous path
61 * - identifiers of mixin nodes on the path to the target node - required for construction of full valid
63 * - {@link LinkedPathElement} of the previous non-mixin node - required to successfully create a chain
64 * of {@link PathArgument}s
66 * @param parentPathElement parent path element
67 * @param mixinNodesToTarget identifiers of mixin nodes on the path to the target node
68 * @param targetNode target non-mixin node
70 private record LinkedPathElement(
71 @Nullable LinkedPathElement parentPathElement,
72 @NonNull List<PathArgument> mixinNodesToTarget,
73 @NonNull DataSchemaContext targetNode) {
75 requireNonNull(mixinNodesToTarget);
76 requireNonNull(targetNode);
80 private NetconfFieldsTranslator() {
85 * Translate a {@link FieldsParam} to a list of child node paths saved in lists, suitable for use with
86 * {@link NetconfDataTreeService}.
88 * @param modelContext EffectiveModelContext
89 * @param startNode Root DataSchemaNode
90 * @param input input value of fields parameter
91 * @return {@link List} of {@link YangInstanceIdentifier} that are relative to the last {@link PathArgument}
92 * of provided {@code identifier}
94 public static @NonNull List<YangInstanceIdentifier> translate(
95 final @NonNull EffectiveModelContext modelContext, final @NonNull DataSchemaContext startNode,
96 final @NonNull FieldsParam input) {
97 final var parsed = new HashSet<LinkedPathElement>();
98 processSelectors(parsed, modelContext, startNode.dataSchemaNode().getQName().getModule(),
99 new LinkedPathElement(null, List.of(), startNode), input.nodeSelectors());
100 return parsed.stream().map(NetconfFieldsTranslator::buildPath).toList();
103 private static void processSelectors(final Set<LinkedPathElement> parsed, final EffectiveModelContext context,
104 final QNameModule startNamespace, final LinkedPathElement startPathElement,
105 final List<NodeSelector> selectors) {
106 for (var selector : selectors) {
107 var pathElement = startPathElement;
108 var namespace = startNamespace;
110 // Note: path is guaranteed to have at least one step
111 final var it = selector.path().iterator();
113 final var step = it.next();
114 final var module = step.module();
115 if (module != null) {
116 // FIXME: this is not defensive enough, as we can fail to find the module
117 namespace = context.findModules(module).iterator().next().getQNameModule();
120 // add parsed path element linked to its parent
121 pathElement = addChildPathElement(pathElement, step.identifier().bindTo(namespace));
122 } while (it.hasNext());
124 final var subs = selector.subSelectors();
125 if (!subs.isEmpty()) {
126 processSelectors(parsed, context, namespace, pathElement, subs);
128 parsed.add(pathElement);
133 private static LinkedPathElement addChildPathElement(final LinkedPathElement currentElement,
134 final QName childQName) {
135 final var collectedMixinNodes = new ArrayList<PathArgument>();
137 DataSchemaContext currentNode = currentElement.targetNode;
138 DataSchemaContext actualContextNode = childByQName(currentNode, childQName);
139 if (actualContextNode == null) {
140 actualContextNode = resolveMixinNode(currentNode, currentNode.getPathStep().getNodeType());
141 actualContextNode = childByQName(actualContextNode, childQName);
144 while (actualContextNode != null && actualContextNode instanceof PathMixin) {
145 final var actualDataSchemaNode = actualContextNode.dataSchemaNode();
146 if (actualDataSchemaNode instanceof ListSchemaNode listSchema && listSchema.getKeyDefinition().isEmpty()) {
147 // we need just a single node identifier from list in the path IFF it is an unkeyed list, otherwise
148 // we need both (which is the default case)
149 actualContextNode = childByQName(actualContextNode, childQName);
150 } else if (actualDataSchemaNode instanceof LeafListSchemaNode) {
151 // NodeWithValue is unusable - stop parsing
154 collectedMixinNodes.add(actualContextNode.getPathStep());
155 actualContextNode = childByQName(actualContextNode, childQName);
159 if (actualContextNode == null) {
160 throw new RestconfDocumentedException("Child " + childQName.getLocalName() + " node missing in "
161 + currentNode.getPathStep().getNodeType().getLocalName(),
162 ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
165 return new LinkedPathElement(currentElement, collectedMixinNodes, actualContextNode);
168 private static @Nullable DataSchemaContext childByQName(final DataSchemaContext parent, final QName qname) {
169 return parent instanceof DataSchemaContext.Composite composite ? composite.childByQName(qname) : null;
172 private static YangInstanceIdentifier buildPath(final LinkedPathElement lastPathElement) {
173 LinkedPathElement pathElement = lastPathElement;
174 final var path = new LinkedList<PathArgument>();
176 path.addFirst(contextPathArgument(pathElement.targetNode));
177 path.addAll(0, pathElement.mixinNodesToTarget);
178 pathElement = pathElement.parentPathElement;
179 } while (pathElement.parentPathElement != null);
181 return YangInstanceIdentifier.of(path);
184 private static @NonNull PathArgument contextPathArgument(final DataSchemaContext context) {
185 final var arg = context.pathStep();
190 final var schema = context.dataSchemaNode();
191 if (schema instanceof ListSchemaNode listSchema && !listSchema.getKeyDefinition().isEmpty()) {
192 return NodeIdentifierWithPredicates.of(listSchema.getQName());
194 if (schema instanceof LeafListSchemaNode leafListSchema) {
195 return new NodeWithValue<>(leafListSchema.getQName(), Empty.value());
197 throw new UnsupportedOperationException("Unsupported schema " + schema);
200 private static DataSchemaContext resolveMixinNode(final DataSchemaContext node,
201 final @NonNull QName qualifiedName) {
202 DataSchemaContext currentNode = node;
203 while (currentNode != null && currentNode instanceof PathMixin currentMixin) {
204 currentNode = currentMixin.childByQName(qualifiedName);