2 * Copyright (c) 2013 Cisco Systems, Inc. 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.annotations.VisibleForTesting;
16 import com.google.common.base.Splitter;
17 import com.google.common.collect.Iterables;
18 import java.util.ArrayDeque;
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.Deque;
22 import java.util.HashSet;
23 import java.util.Iterator;
24 import java.util.List;
25 import java.util.Optional;
27 import java.util.regex.Pattern;
28 import java.util.stream.Collectors;
29 import org.eclipse.jdt.annotation.NonNull;
30 import org.eclipse.jdt.annotation.Nullable;
31 import org.opendaylight.yangtools.yang.common.AbstractQName;
32 import org.opendaylight.yangtools.yang.common.QName;
33 import org.opendaylight.yangtools.yang.common.QNameModule;
34 import org.opendaylight.yangtools.yang.common.UnqualifiedQName;
35 import org.opendaylight.yangtools.yang.model.api.ActionNodeContainer;
36 import org.opendaylight.yangtools.yang.model.api.CaseSchemaNode;
37 import org.opendaylight.yangtools.yang.model.api.ChoiceSchemaNode;
38 import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
39 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
40 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
41 import org.opendaylight.yangtools.yang.model.api.DerivableSchemaNode;
42 import org.opendaylight.yangtools.yang.model.api.GroupingDefinition;
43 import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
44 import org.opendaylight.yangtools.yang.model.api.Module;
45 import org.opendaylight.yangtools.yang.model.api.ModuleImport;
46 import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
47 import org.opendaylight.yangtools.yang.model.api.NotificationNodeContainer;
48 import org.opendaylight.yangtools.yang.model.api.OperationDefinition;
49 import org.opendaylight.yangtools.yang.model.api.PathExpression;
50 import org.opendaylight.yangtools.yang.model.api.PathExpression.DerefSteps;
51 import org.opendaylight.yangtools.yang.model.api.PathExpression.LocationPathSteps;
52 import org.opendaylight.yangtools.yang.model.api.PathExpression.Steps;
53 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
54 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
55 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
56 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
57 import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
58 import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
59 import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
60 import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
61 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
62 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
63 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath;
64 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.AxisStep;
65 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.QNameStep;
66 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.ResolvedQNameStep;
67 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Step;
68 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.UnresolvedQNameStep;
69 import org.opendaylight.yangtools.yang.xpath.api.YangXPathAxis;
70 import org.slf4j.Logger;
71 import org.slf4j.LoggerFactory;
74 * The Schema Context Util contains support methods for searching through Schema Context modules for specified schema
75 * nodes via Schema Path or Revision Aware XPath. The Schema Context Util is designed as mixin, so it is not
78 public final class SchemaContextUtil {
79 private static final Logger LOG = LoggerFactory.getLogger(SchemaContextUtil.class);
80 private static final Splitter COLON_SPLITTER = Splitter.on(':');
81 private static final Splitter SLASH_SPLITTER = Splitter.on('/').omitEmptyStrings();
83 private SchemaContextUtil() {
88 * Method attempts to find DataSchemaNode in Schema Context via specified Schema Path. The returned DataSchemaNode
89 * from method will be the node at the end of the SchemaPath. If the DataSchemaNode is not present in the Schema
90 * Context the method will return {@code null}.
93 * In case that Schema Context or Schema Path are not specified correctly (i.e. contains {@code null} values) the
94 * method will throw IllegalArgumentException.
96 * @param context Schema Context
97 * @param schemaPath Schema Path to search for
98 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
99 * @throws NullPointerException if context or schemaPath is null
101 public static SchemaNode findDataSchemaNode(final SchemaContext context, final SchemaPath schemaPath) {
102 final Iterable<QName> prefixedPath = schemaPath.getPathFromRoot();
103 if (prefixedPath == null) {
104 LOG.debug("Schema path {} has null path", schemaPath);
108 LOG.trace("Looking for path {} in context {}", schemaPath, context);
109 return findNodeInSchemaContext(context, prefixedPath);
113 * Attempt to find a DataSchemaNode based on its path from root, similar to
114 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
116 * @param context Schema Context
117 * @param path Path to search for
118 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
119 * @throws NullPointerException if a any argument is null or if the path contains a null element
122 public static SchemaNode findDataSchemaNode(final SchemaContext context, final List<QName> path) {
123 return findTargetNode(context, null, YangLocationPath.absolute(
124 path.stream().map(YangXPathAxis.CHILD::asStep).collect(Collectors.toList())));
128 * Attempt to find a DataSchemaNode based on its path from root, similar to
129 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
131 * @param context Schema Context
132 * @param path Path to search for
133 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
134 * @throws NullPointerException if a any argument is null or if the path contains a null element
137 public static SchemaNode findDataSchemaNode(final SchemaContext context, final QName... path) {
138 return findDataSchemaNode(context, Arrays.asList(path));
142 * Method attempts to find DataSchemaNode inside of provided Schema Context
143 * and Yang Module accordingly to Non-conditional Revision Aware XPath. The
144 * specified Module MUST be present in Schema Context otherwise the
145 * operation would fail and return <code>null</code>. <br>
146 * The Revision Aware XPath MUST be specified WITHOUT the conditional
147 * statement (i.e. without [cond]) in path, because in this state the Schema
148 * Context is completely unaware of data state and will be not able to
149 * properly resolve XPath. If the XPath contains condition the method will
150 * return IllegalArgumentException. <br>
151 * If the Revision Aware XPath is correct and desired Data Schema Node is
152 * present in Yang module or in depending module in Schema Context the
153 * method will return specified Data Schema Node, otherwise the operation
154 * will fail and method will return <code>null</code>.
160 * @param nonCondXPath
161 * Non Conditional Revision Aware XPath
162 * @return Returns Data Schema Node for specified Schema Context for given
163 * Non-conditional Revision Aware XPath, or <code>null</code> if the
164 * DataSchemaNode is not present in Schema Context.
165 * @throws NullPointerException if any of the arguments is null
166 * @deprecated Use {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, YangLocationPath)} or
167 * {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, PathExpression)} instead.
169 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
170 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
173 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
174 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
175 // via a derived SchemaContext (i.e. this class would have to have a
177 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
179 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
180 // that feels like an overkill.
182 public static SchemaNode findDataSchemaNode(final SchemaContext context, final Module module,
183 final PathExpression nonCondXPath) {
184 requireNonNull(context, "context");
185 requireNonNull(module, "module");
187 final String strXPath = nonCondXPath.getOriginalString();
188 checkArgument(strXPath.indexOf('[') == -1, "Revision Aware XPath may not contain a condition");
189 if (nonCondXPath.isAbsolute()) {
190 return findTargetNode(context, xpathToQNamePath(context, module, strXPath));
196 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
197 final YangLocationPath absPath) {
198 checkArgument(absPath.isAbsolute(), "Unsupported relative path %s", absPath);
199 return findTargetNode(ctx, localModule, absPath);
203 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
204 final PathExpression absPath) {
205 final Steps pathSteps = absPath.getSteps();
206 if (pathSteps instanceof LocationPathSteps) {
207 return findDataTreeSchemaNode(ctx, localModule, ((LocationPathSteps) pathSteps).getLocationPath());
210 // We would need a reference schema node and no, we do not want to use SchemaContext in its SchemaNode capacity
211 checkArgument(!(pathSteps instanceof DerefSteps), "No reference node for steps %s", pathSteps);
213 // We are missing proper API alignment, if this ever triggers
214 throw new IllegalStateException("Unsupported path " + pathSteps);
218 * Method attempts to find DataSchemaNode inside of provided Schema Context
219 * and Yang Module accordingly to Non-conditional relative Revision Aware
220 * XPath. The specified Module MUST be present in Schema Context otherwise
221 * the operation would fail and return <code>null</code>. <br>
222 * The relative Revision Aware XPath MUST be specified WITHOUT the
223 * conditional statement (i.e. without [cond]) in path, because in this
224 * state the Schema Context is completely unaware of data state and will be
225 * not able to properly resolve XPath. If the XPath contains condition the
226 * method will return IllegalArgumentException. <br>
227 * The Actual Schema Node MUST be specified correctly because from this
228 * Schema Node will search starts. If the Actual Schema Node is not correct
229 * the operation will simply fail, because it will be unable to find desired
230 * DataSchemaNode. <br>
231 * If the Revision Aware XPath doesn't have flag
232 * <code>isAbsolute == false</code> the method will throw
233 * IllegalArgumentException. <br>
234 * If the relative Revision Aware XPath is correct and desired Data Schema
235 * Node is present in Yang module or in depending module in Schema Context
236 * the method will return specified Data Schema Node, otherwise the
237 * operation will fail and method will return <code>null</code>.
243 * @param actualSchemaNode
245 * @param relativeXPath
246 * Relative Non Conditional Revision Aware XPath
247 * @return DataSchemaNode if is present in specified Schema Context for
248 * given relative Revision Aware XPath, otherwise will return
250 * @throws NullPointerException if any argument is null
252 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
253 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
256 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
257 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
258 // via a derived SchemaContext (i.e. this class would have to have a
260 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
262 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
263 // that feels like an overkill.
264 // FIXME: YANGTOOLS-1052: this is a static analysis util, move it to a dedicated class
265 public static SchemaNode findDataSchemaNodeForRelativeXPath(final SchemaContext context, final Module module,
266 final SchemaNode actualSchemaNode, final PathExpression relativeXPath) {
267 checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
268 + "for non relative Revision Aware XPath use findDataSchemaNode method");
269 return resolveRelativeXPath(context, module, relativeXPath, actualSchemaNode);
273 * Returns parent Yang Module for specified Schema Context in which Schema
274 * Node is declared. If the Schema Node is not present in Schema Context the
275 * operation will return <code>null</code>.
277 * @param context Schema Context
278 * @param schemaNode Schema Node
279 * @return Yang Module for specified Schema Context and Schema Node, if Schema Node is NOT present, the method will
280 * return <code>null</code>
281 * @throws NullPointerException if any of the arguments is null
283 public static Module findParentModule(final SchemaContext context, final SchemaNode schemaNode) {
284 final QName qname = schemaNode.getPath().getLastComponent();
285 checkState(qname != null, "Schema Path contains invalid state of path parts. "
286 + "The Schema Path MUST contain at least ONE QName which defines namespace and Local name of path.");
287 return context.findModule(qname.getModule()).orElse(null);
290 public static SchemaNode findNodeInSchemaContext(final SchemaContext context, final Iterable<QName> path) {
291 final QName current = path.iterator().next();
293 LOG.trace("Looking up module {} in context {}", current, path);
294 final Optional<Module> module = context.findModule(current.getModule());
295 if (module.isEmpty()) {
296 LOG.debug("Module {} not found", current);
300 return findNodeInModule(module.get(), path);
304 * Returns NotificationDefinition from Schema Context.
306 * @param schema SchemaContext in which lookup should be performed.
307 * @param path Schema Path of notification
308 * @return Notification schema or null, if notification is not present in schema context.
311 public static @Nullable NotificationDefinition getNotificationSchema(final @NonNull SchemaContext schema,
312 final @NonNull SchemaPath path) {
313 requireNonNull(schema, "Schema context must not be null.");
314 requireNonNull(path, "Schema path must not be null.");
315 for (final NotificationDefinition potential : schema.getNotifications()) {
316 if (path.equals(potential.getPath())) {
324 * Returns RPC Input or Output Data container from RPC definition.
326 * @param schema SchemaContext in which lookup should be performed.
327 * @param path Schema path of RPC input/output data container
328 * @return Notification schema or null, if notification is not present in schema context.
331 public static @Nullable ContainerSchemaNode getRpcDataSchema(final @NonNull SchemaContext schema,
332 final @NonNull SchemaPath path) {
333 requireNonNull(schema, "Schema context must not be null.");
334 requireNonNull(path, "Schema path must not be null.");
335 final Iterator<QName> it = path.getPathFromRoot().iterator();
336 checkArgument(it.hasNext(), "Rpc must have QName.");
337 final QName rpcName = it.next();
338 checkArgument(it.hasNext(), "input or output must be part of path.");
339 final QName inOrOut = it.next();
340 for (final RpcDefinition potential : schema.getOperations()) {
341 if (rpcName.equals(potential.getQName())) {
342 return SchemaNodeUtils.getRpcDataSchema(potential, inOrOut);
349 * Extract the identifiers of all modules and submodules which were used to create a particular SchemaContext.
351 * @param context SchemaContext to be examined
352 * @return Set of ModuleIdentifiers.
354 public static Set<SourceIdentifier> getConstituentModuleIdentifiers(final SchemaContext context) {
355 final Set<SourceIdentifier> ret = new HashSet<>();
357 for (Module module : context.getModules()) {
358 ret.add(moduleToIdentifier(module));
360 for (Module submodule : module.getSubmodules()) {
361 ret.add(moduleToIdentifier(submodule));
368 private static SourceIdentifier moduleToIdentifier(final Module module) {
369 return RevisionSourceIdentifier.create(module.getName(), module.getRevision());
372 private static SchemaNode findNodeInModule(final Module module, final Iterable<QName> path) {
373 if (!path.iterator().hasNext()) {
374 LOG.debug("No node matching {} found in node {}", path, module);
378 final QName current = path.iterator().next();
379 LOG.trace("Looking for node {} in module {}", current, module);
381 SchemaNode foundNode = null;
382 final Iterable<QName> nextPath = nextLevel(path);
384 foundNode = module.getDataChildByName(current);
385 if (foundNode != null && nextPath.iterator().hasNext()) {
386 foundNode = findNodeIn(foundNode, nextPath);
389 if (foundNode == null) {
390 foundNode = getGroupingByName(module, current);
391 if (foundNode != null && nextPath.iterator().hasNext()) {
392 foundNode = findNodeIn(foundNode, nextPath);
396 if (foundNode == null) {
397 foundNode = getRpcByName(module, current);
398 if (foundNode != null && nextPath.iterator().hasNext()) {
399 foundNode = findNodeIn(foundNode, nextPath);
403 if (foundNode == null) {
404 foundNode = getNotificationByName(module, current);
405 if (foundNode != null && nextPath.iterator().hasNext()) {
406 foundNode = findNodeIn(foundNode, nextPath);
410 if (foundNode == null) {
411 LOG.debug("No node matching {} found in node {}", path, module);
417 private static SchemaNode findNodeIn(final SchemaNode parent, final Iterable<QName> path) {
418 if (!path.iterator().hasNext()) {
419 LOG.debug("No node matching {} found in node {}", path, parent);
423 final QName current = path.iterator().next();
424 LOG.trace("Looking for node {} in node {}", current, parent);
426 SchemaNode foundNode = null;
427 final Iterable<QName> nextPath = nextLevel(path);
429 if (parent instanceof DataNodeContainer) {
430 final DataNodeContainer parentDataNodeContainer = (DataNodeContainer) parent;
432 foundNode = parentDataNodeContainer.getDataChildByName(current);
433 if (foundNode != null && nextPath.iterator().hasNext()) {
434 foundNode = findNodeIn(foundNode, nextPath);
437 if (foundNode == null) {
438 foundNode = getGroupingByName(parentDataNodeContainer, current);
439 if (foundNode != null && nextPath.iterator().hasNext()) {
440 foundNode = findNodeIn(foundNode, nextPath);
445 if (foundNode == null && parent instanceof ActionNodeContainer) {
446 foundNode = ((ActionNodeContainer) parent).getActions().stream()
447 .filter(act -> current.equals(act.getQName())).findFirst().orElse(null);
448 if (foundNode != null && nextPath.iterator().hasNext()) {
449 foundNode = findNodeIn(foundNode, nextPath);
453 if (foundNode == null && parent instanceof NotificationNodeContainer) {
454 foundNode = ((NotificationNodeContainer) parent).getNotifications().stream()
455 .filter(notif -> current.equals(notif.getQName())).findFirst().orElse(null);
456 if (foundNode != null && nextPath.iterator().hasNext()) {
457 foundNode = findNodeIn(foundNode, nextPath);
461 if (foundNode == null && parent instanceof OperationDefinition) {
462 final OperationDefinition parentRpcDefinition = (OperationDefinition) parent;
464 if (current.getLocalName().equals("input")) {
465 foundNode = parentRpcDefinition.getInput();
466 if (foundNode != null && nextPath.iterator().hasNext()) {
467 foundNode = findNodeIn(foundNode, nextPath);
471 if (current.getLocalName().equals("output")) {
472 foundNode = parentRpcDefinition.getOutput();
473 if (foundNode != null && nextPath.iterator().hasNext()) {
474 foundNode = findNodeIn(foundNode, nextPath);
478 if (foundNode == null) {
479 foundNode = getGroupingByName(parentRpcDefinition, current);
480 if (foundNode != null && nextPath.iterator().hasNext()) {
481 foundNode = findNodeIn(foundNode, nextPath);
486 if (foundNode == null && parent instanceof ChoiceSchemaNode) {
487 foundNode = ((ChoiceSchemaNode) parent).getCaseNodeByName(current);
489 if (foundNode != null && nextPath.iterator().hasNext()) {
490 foundNode = findNodeIn(foundNode, nextPath);
493 if (foundNode == null) {
494 // fallback that tries to map into one of the child cases
495 for (final CaseSchemaNode caseNode : ((ChoiceSchemaNode) parent).getCases().values()) {
496 final DataSchemaNode maybeChild = caseNode.getDataChildByName(current);
497 if (maybeChild != null) {
498 foundNode = findNodeIn(maybeChild, nextPath);
505 if (foundNode == null) {
506 LOG.debug("No node matching {} found in node {}", path, parent);
513 private static Iterable<QName> nextLevel(final Iterable<QName> path) {
514 return Iterables.skip(path, 1);
517 private static RpcDefinition getRpcByName(final Module module, final QName name) {
518 for (final RpcDefinition rpc : module.getRpcs()) {
519 if (rpc.getQName().equals(name)) {
526 private static NotificationDefinition getNotificationByName(final Module module, final QName name) {
527 for (final NotificationDefinition notification : module.getNotifications()) {
528 if (notification.getQName().equals(name)) {
535 private static GroupingDefinition getGroupingByName(final DataNodeContainer dataNodeContainer, final QName name) {
536 for (final GroupingDefinition grouping : dataNodeContainer.getGroupings()) {
537 if (grouping.getQName().equals(name)) {
544 private static GroupingDefinition getGroupingByName(final OperationDefinition rpc, final QName name) {
545 for (final GroupingDefinition grouping : rpc.getGroupings()) {
546 if (grouping.getQName().equals(name)) {
554 * Transforms string representation of XPath to Queue of QNames. The XPath
555 * is split by "/" and for each part of XPath is assigned correct module in
557 * If Schema Context, Parent Module or XPath string contains
558 * <code>null</code> values, the method will throws IllegalArgumentException
562 * @param parentModule
566 * @return return a list of QName
568 private static List<QName> xpathToQNamePath(final SchemaContext context, final Module parentModule,
569 final String xpath) {
570 final List<QName> path = new ArrayList<>();
571 for (final String pathComponent : SLASH_SPLITTER.split(xpath)) {
572 path.add(stringPathPartToQName(context, parentModule, pathComponent));
578 * Transforms part of Prefixed Path as java String to QName. <br>
579 * If the string contains module prefix separated by ":" (i.e.
580 * mod:container) this module is provided from from Parent Module list of
581 * imports. If the Prefixed module is present in Schema Context the QName
582 * can be constructed. <br>
583 * If the Prefixed Path Part does not contains prefix the Parent's Module
584 * namespace is taken for construction of QName. <br>
586 * @param context Schema Context
587 * @param parentModule Parent Module
588 * @param prefixedPathPart Prefixed Path Part string
589 * @return QName from prefixed Path Part String.
590 * @throws NullPointerException if any arguments are null
592 private static QName stringPathPartToQName(final SchemaContext context, final Module parentModule,
593 final String prefixedPathPart) {
594 requireNonNull(context, "context");
596 if (prefixedPathPart.indexOf(':') != -1) {
597 final Iterator<String> prefixedName = COLON_SPLITTER.split(prefixedPathPart).iterator();
598 final String modulePrefix = prefixedName.next();
600 final Module module = resolveModuleForPrefix(context, parentModule, modulePrefix);
601 checkArgument(module != null, "Failed to resolve xpath: no module found for prefix %s in module %s",
602 modulePrefix, parentModule.getName());
604 return QName.create(module.getQNameModule(), prefixedName.next());
607 return QName.create(parentModule.getNamespace(), parentModule.getRevision(), prefixedPathPart);
611 * Method will attempt to resolve and provide Module reference for specified module prefix. Each Yang module could
612 * contains multiple imports which MUST be associated with corresponding module prefix. The method simply looks into
613 * module imports and returns the module that is bounded with specified prefix. If the prefix is not present
614 * in module or the prefixed module is not present in specified Schema Context, the method will return {@code null}.
616 * If String prefix is the same as prefix of the specified Module the reference to this module is returned.<br>
618 * @param context Schema Context
619 * @param module Yang Module
620 * @param prefix Module Prefix
621 * @return Module for given prefix in specified Schema Context if is present, otherwise returns <code>null</code>
622 * @throws NullPointerException if any arguments are null
624 private static Module resolveModuleForPrefix(final SchemaContext context, final Module module,
625 final String prefix) {
626 requireNonNull(context, "context");
628 if (prefix.equals(module.getPrefix())) {
632 final Set<ModuleImport> imports = module.getImports();
633 for (final ModuleImport mi : imports) {
634 if (prefix.equals(mi.getPrefix())) {
635 return context.findModule(mi.getModuleName(), mi.getRevision()).orElse(null);
642 * Resolve a relative XPath into a set of QNames.
648 * @param relativeXPath
649 * Non conditional Revision Aware Relative XPath
650 * @param actualSchemaNode
652 * @return target schema node
653 * @throws IllegalArgumentException if any arguments are null
655 private static @Nullable SchemaNode resolveRelativeXPath(final SchemaContext context, final Module module,
656 final PathExpression relativeXPath, final SchemaNode actualSchemaNode) {
657 checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
658 + "for non relative Revision Aware XPath use findDataSchemaNode method");
659 checkState(actualSchemaNode.getPath() != null, "Schema Path reference for Leafref cannot be NULL");
661 final String orig = relativeXPath.getOriginalString();
662 return orig.startsWith("deref(") ? resolveDerefPath(context, module, actualSchemaNode, orig)
663 : findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode, doSplitXPath(orig)));
666 private static Iterable<QName> resolveRelativePath(final SchemaContext context, final Module module,
667 final SchemaNode actualSchemaNode, final List<String> steps) {
668 // Find out how many "parent" components there are and trim them
669 final int colCount = normalizeXPath(steps);
670 final List<String> xpaths = colCount == 0 ? steps : steps.subList(colCount, steps.size());
672 final Iterable<QName> schemaNodePath = actualSchemaNode.getPath().getPathFromRoot();
673 if (Iterables.size(schemaNodePath) - colCount >= 0) {
674 return Iterables.concat(Iterables.limit(schemaNodePath, Iterables.size(schemaNodePath) - colCount),
675 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
677 return Iterables.concat(schemaNodePath,
678 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
681 private static SchemaNode resolveDerefPath(final SchemaContext context, final Module module,
682 final SchemaNode actualSchemaNode, final String xpath) {
683 final int paren = xpath.indexOf(')', 6);
684 checkArgument(paren != -1, "Cannot find matching parentheses in %s", xpath);
686 final String derefArg = xpath.substring(6, paren).strip();
687 // Look up the node which we need to reference
688 final SchemaNode derefTarget = findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
689 doSplitXPath(derefArg)));
690 checkArgument(derefTarget != null, "Cannot find deref(%s) target node %s in context of %s", derefArg,
692 checkArgument(derefTarget instanceof TypedDataSchemaNode, "deref(%s) resolved to non-typed %s", derefArg,
695 // We have a deref() target, decide what to do about it
696 final TypeDefinition<?> targetType = ((TypedDataSchemaNode) derefTarget).getType();
697 if (targetType instanceof InstanceIdentifierTypeDefinition) {
698 // Static inference breaks down, we cannot determine where this points to
699 // FIXME: dedicated exception, users can recover from it, derive from IAE
700 throw new UnsupportedOperationException("Cannot infer instance-identifier reference " + targetType);
703 // deref() is define only for instance-identifier and leafref types, handle the latter
704 checkArgument(targetType instanceof LeafrefTypeDefinition, "Illegal target type %s", targetType);
706 final PathExpression targetPath = ((LeafrefTypeDefinition) targetType).getPathStatement();
707 LOG.debug("Derefencing path {}", targetPath);
709 final SchemaNode deref = targetPath.isAbsolute()
710 ? findTargetNode(context, actualSchemaNode.getQName().getModule(),
711 ((LocationPathSteps) targetPath.getSteps()).getLocationPath())
712 : findDataSchemaNodeForRelativeXPath(context, module, actualSchemaNode, targetPath);
714 LOG.debug("Path {} could not be derefenced", targetPath);
718 checkArgument(deref instanceof LeafSchemaNode, "Unexpected %s reference in %s", deref, targetPath);
720 final List<String> qnames = doSplitXPath(xpath.substring(paren + 1).stripLeading());
721 return findTargetNode(context, resolveRelativePath(context, module, deref, qnames));
724 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final QNameModule defaultModule,
725 final YangLocationPath path) {
726 final Deque<QName> ret = new ArrayDeque<>();
727 for (Step step : path.getSteps()) {
728 if (step instanceof AxisStep) {
729 // We only support parent axis steps
730 final YangXPathAxis axis = ((AxisStep) step).getAxis();
731 checkState(axis == YangXPathAxis.PARENT, "Unexpected axis %s", axis);
736 // This has to be a QNameStep
737 checkState(step instanceof QNameStep, "Unhandled step %s in %s", step, path);
739 if (step instanceof ResolvedQNameStep) {
740 qname = ((ResolvedQNameStep) step).getQName();
741 } else if (step instanceof UnresolvedQNameStep) {
742 final AbstractQName toResolve = ((UnresolvedQNameStep) step).getQName();
743 // TODO: should handle qualified QNames, too? parser should have resolved them when we get here...
744 checkState(toResolve instanceof UnqualifiedQName, "Unhandled qname %s in %s", toResolve, path);
745 qname = QName.create(defaultModule, toResolve.getLocalName());
747 throw new IllegalStateException("Unhandled step " + step);
753 return findTargetNode(context, ret);
756 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final Iterable<QName> qnamePath) {
757 // We do not have enough information about resolution context, hence cannot account for actions, RPCs
758 // and notifications. We therefore attempt to make a best estimate, but this can still fail.
759 final Optional<DataSchemaNode> pureData = context.findDataTreeChild(qnamePath);
760 return pureData.isPresent() ? pureData.get() : findNodeInSchemaContext(context, qnamePath);
764 static int normalizeXPath(final List<String> xpath) {
765 LOG.trace("Normalize {}", xpath);
767 // We need to make multiple passes here, as the leading XPaths as we can have "../abc/../../def", which really
770 // Next up: count leading ".." components
771 int leadingParents = 0;
773 if (leadingParents == xpath.size()) {
774 return leadingParents;
776 if (!"..".equals(xpath.get(leadingParents))) {
783 // Now let's see if there there is a '..' in the rest
784 final int dots = findDots(xpath, leadingParents + 1);
786 return leadingParents;
789 xpath.remove(dots - 1);
790 xpath.remove(dots - 1);
791 LOG.trace("Next iteration {}", xpath);
795 private static int findDots(final List<String> xpath, final int startIndex) {
796 for (int i = startIndex; i < xpath.size(); ++i) {
797 if ("..".equals(xpath.get(i))) {
805 private static List<String> doSplitXPath(final String xpath) {
806 return SLASH_SPLITTER.splitToList(xpath);
810 * Extracts the base type of node on which schema node points to. If target node is again of type
811 * LeafrefTypeDefinition, methods will be call recursively until it reach concrete type definition.
813 * @param typeDefinition
814 * type of node which will be extracted
815 * @param schemaContext
819 * @return recursively found type definition this leafref is pointing to or null if the xpath is incorrect (null
820 * is there to preserve backwards compatibility)
822 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
823 final SchemaContext schemaContext, final SchemaNode schema) {
824 PathExpression pathStatement = typeDefinition.getPathStatement();
825 pathStatement = new PathExpressionImpl(stripConditionsFromXPathString(pathStatement),
826 pathStatement.isAbsolute());
828 final DataSchemaNode dataSchemaNode;
829 if (pathStatement.isAbsolute()) {
830 SchemaNode baseSchema = schema;
831 while (baseSchema instanceof DerivableSchemaNode) {
832 final Optional<? extends SchemaNode> basePotential = ((DerivableSchemaNode) baseSchema).getOriginal();
833 if (basePotential.isPresent()) {
834 baseSchema = basePotential.get();
840 Module parentModule = findParentModuleOfReferencingType(schemaContext, baseSchema);
841 dataSchemaNode = (DataSchemaNode) findDataSchemaNode(schemaContext, parentModule, pathStatement);
843 Module parentModule = findParentModule(schemaContext, schema);
844 dataSchemaNode = (DataSchemaNode) findDataSchemaNodeForRelativeXPath(schemaContext, parentModule, schema,
848 // FIXME this is just to preserve backwards compatibility since yangtools do not mind wrong leafref xpaths
849 // and current expected behaviour for such cases is to just use pure string
850 // This should throw an exception about incorrect XPath in leafref
851 if (dataSchemaNode == null) {
855 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
857 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
858 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
861 return targetTypeDefinition;
865 * Returns base type for {@code typeDefinition} which belongs to module specified via {@code qname}. This handle
866 * the case when leafref type isn't specified as type substatement of leaf or leaf-list but is defined in other
867 * module as typedef which is then imported to referenced module.
870 * Because {@code typeDefinition} is definied via typedef statement, only absolute path is meaningful.
872 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
873 final SchemaContext schemaContext, final QName qname) {
874 final PathExpression pathStatement = typeDefinition.getPathStatement();
875 if (!pathStatement.isAbsolute()) {
879 final PathExpression strippedPathStatement = new PathExpressionImpl(
880 stripConditionsFromXPathString(pathStatement), true);
882 final Optional<Module> parentModule = schemaContext.findModule(qname.getModule());
883 checkArgument(parentModule.isPresent(), "Failed to find parent module for %s", qname);
885 final DataSchemaNode dataSchemaNode = (DataSchemaNode) findDataSchemaNode(schemaContext, parentModule.get(),
886 strippedPathStatement);
887 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
888 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
889 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
892 return targetTypeDefinition;
895 private static Module findParentModuleOfReferencingType(final SchemaContext schemaContext,
896 final SchemaNode schemaNode) {
897 checkArgument(schemaContext != null, "Schema Context reference cannot be NULL!");
898 checkArgument(schemaNode instanceof TypedDataSchemaNode, "Unsupported node %s", schemaNode);
900 TypeDefinition<?> nodeType = ((TypedDataSchemaNode) schemaNode).getType();
901 if (nodeType.getBaseType() != null) {
902 while (nodeType.getBaseType() != null) {
903 nodeType = nodeType.getBaseType();
906 return schemaContext.findModule(nodeType.getQName().getModule()).orElse(null);
909 return findParentModule(schemaContext, schemaNode);
912 private static final Pattern STRIP_PATTERN = Pattern.compile("\\[[^\\[\\]]*\\]");
915 * Removes conditions from xPath pointed to target node.
917 * @param pathStatement
918 * xPath to target node
919 * @return string representation of xPath without conditions
922 static String stripConditionsFromXPathString(final PathExpression pathStatement) {
923 return STRIP_PATTERN.matcher(pathStatement.getOriginalString()).replaceAll("");
927 * Gets the base type of DataSchemaNode value.
930 * a node representing DataSchemaNode
931 * @return concrete type definition of node value
933 private static TypeDefinition<?> typeDefinition(final DataSchemaNode node) {
934 checkArgument(node instanceof TypedDataSchemaNode, "Unhandled parameter type %s", node);
936 TypeDefinition<?> current = ((TypedDataSchemaNode) node).getType();
937 // TODO: don't we have a utility for this?
938 TypeDefinition<?> base = current.getBaseType();
939 while (base != null) {
941 base = current.getBaseType();