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 com.google.common.collect.Lists;
19 import java.util.ArrayDeque;
20 import java.util.ArrayList;
21 import java.util.Arrays;
22 import java.util.Deque;
23 import java.util.HashSet;
24 import java.util.Iterator;
25 import java.util.List;
26 import java.util.Optional;
28 import java.util.regex.Pattern;
29 import java.util.stream.Collectors;
30 import org.eclipse.jdt.annotation.NonNull;
31 import org.eclipse.jdt.annotation.Nullable;
32 import org.opendaylight.yangtools.yang.common.AbstractQName;
33 import org.opendaylight.yangtools.yang.common.QName;
34 import org.opendaylight.yangtools.yang.common.QNameModule;
35 import org.opendaylight.yangtools.yang.common.UnqualifiedQName;
36 import org.opendaylight.yangtools.yang.model.api.ActionNodeContainer;
37 import org.opendaylight.yangtools.yang.model.api.CaseSchemaNode;
38 import org.opendaylight.yangtools.yang.model.api.ChoiceSchemaNode;
39 import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
40 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
41 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
42 import org.opendaylight.yangtools.yang.model.api.DerivableSchemaNode;
43 import org.opendaylight.yangtools.yang.model.api.GroupingDefinition;
44 import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
45 import org.opendaylight.yangtools.yang.model.api.Module;
46 import org.opendaylight.yangtools.yang.model.api.ModuleImport;
47 import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
48 import org.opendaylight.yangtools.yang.model.api.NotificationNodeContainer;
49 import org.opendaylight.yangtools.yang.model.api.OperationDefinition;
50 import org.opendaylight.yangtools.yang.model.api.PathExpression;
51 import org.opendaylight.yangtools.yang.model.api.PathExpression.DerefSteps;
52 import org.opendaylight.yangtools.yang.model.api.PathExpression.LocationPathSteps;
53 import org.opendaylight.yangtools.yang.model.api.PathExpression.Steps;
54 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
55 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
56 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
57 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
58 import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
59 import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
60 import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
61 import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
62 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
63 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
64 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath;
65 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.AxisStep;
66 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.QNameStep;
67 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Step;
68 import org.opendaylight.yangtools.yang.xpath.api.YangXPathAxis;
69 import org.slf4j.Logger;
70 import org.slf4j.LoggerFactory;
73 * The Schema Context Util contains support methods for searching through Schema Context modules for specified schema
74 * nodes via Schema Path or Revision Aware XPath. The Schema Context Util is designed as mixin, so it is not
77 public final class SchemaContextUtil {
78 private static final Logger LOG = LoggerFactory.getLogger(SchemaContextUtil.class);
79 private static final Splitter COLON_SPLITTER = Splitter.on(':');
80 private static final Splitter SLASH_SPLITTER = Splitter.on('/').omitEmptyStrings();
82 private SchemaContextUtil() {
87 * Method attempts to find DataSchemaNode in Schema Context via specified Schema Path. The returned DataSchemaNode
88 * from method will be the node at the end of the SchemaPath. If the DataSchemaNode is not present in the Schema
89 * Context the method will return {@code null}.
92 * In case that Schema Context or Schema Path are not specified correctly (i.e. contains {@code null} values) the
93 * method will throw IllegalArgumentException.
95 * @param context Schema Context
96 * @param schemaPath Schema Path to search for
97 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
98 * @throws NullPointerException if context or schemaPath is null
100 public static SchemaNode findDataSchemaNode(final SchemaContext context, final SchemaPath schemaPath) {
101 final Iterable<QName> prefixedPath = schemaPath.getPathFromRoot();
102 if (prefixedPath == null) {
103 LOG.debug("Schema path {} has null path", schemaPath);
107 LOG.trace("Looking for path {} in context {}", schemaPath, context);
108 return findNodeInSchemaContext(context, prefixedPath);
112 * Attempt to find a DataSchemaNode based on its path from root, similar to
113 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
115 * @param context Schema Context
116 * @param path Path to search for
117 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
118 * @throws NullPointerException if a any argument is null or if the path contains a null element
121 public static SchemaNode findDataSchemaNode(final SchemaContext context, final List<QName> path) {
122 return findTargetNode(context, null, YangLocationPath.absolute(
123 path.stream().map(YangXPathAxis.CHILD::asStep).collect(Collectors.toList())));
127 * Attempt to find a DataSchemaNode based on its path from root, similar to
128 * {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
130 * @param context Schema Context
131 * @param path Path to search for
132 * @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
133 * @throws NullPointerException if a any argument is null or if the path contains a null element
136 public static SchemaNode findDataSchemaNode(final SchemaContext context, final QName... path) {
137 return findDataSchemaNode(context, Arrays.asList(path));
141 * Method attempts to find DataSchemaNode inside of provided Schema Context
142 * and Yang Module accordingly to Non-conditional Revision Aware XPath. The
143 * specified Module MUST be present in Schema Context otherwise the
144 * operation would fail and return <code>null</code>. <br>
145 * The Revision Aware XPath MUST be specified WITHOUT the conditional
146 * statement (i.e. without [cond]) in path, because in this state the Schema
147 * Context is completely unaware of data state and will be not able to
148 * properly resolve XPath. If the XPath contains condition the method will
149 * return IllegalArgumentException. <br>
150 * If the Revision Aware XPath is correct and desired Data Schema Node is
151 * present in Yang module or in depending module in Schema Context the
152 * method will return specified Data Schema Node, otherwise the operation
153 * will fail and method will return <code>null</code>.
159 * @param nonCondXPath
160 * Non Conditional Revision Aware XPath
161 * @return Returns Data Schema Node for specified Schema Context for given
162 * Non-conditional Revision Aware XPath, or <code>null</code> if the
163 * DataSchemaNode is not present in Schema Context.
164 * @throws NullPointerException if any of the arguments is null
165 * @deprecated Use {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, YangLocationPath)} or
166 * {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, PathExpression)} instead.
168 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
169 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
172 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
173 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
174 // via a derived SchemaContext (i.e. this class would have to have a
176 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
178 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
179 // that feels like an overkill.
181 public static SchemaNode findDataSchemaNode(final SchemaContext context, final Module module,
182 final PathExpression nonCondXPath) {
183 requireNonNull(context, "context");
184 requireNonNull(module, "module");
186 final String strXPath = nonCondXPath.getOriginalString();
187 checkArgument(strXPath.indexOf('[') == -1, "Revision Aware XPath may not contain a condition");
188 if (nonCondXPath.isAbsolute()) {
189 return findTargetNode(context, xpathToQNamePath(context, module, strXPath));
195 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
196 final YangLocationPath absPath) {
197 checkArgument(absPath.isAbsolute(), "Unsupported relative path %s", absPath);
198 return findTargetNode(ctx, localModule, absPath);
202 public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
203 final PathExpression absPath) {
204 final Steps pathSteps = absPath.getSteps();
205 if (pathSteps instanceof LocationPathSteps) {
206 return findDataTreeSchemaNode(ctx, localModule, ((LocationPathSteps) pathSteps).getLocationPath());
209 // We would need a reference schema node and no, we do not want to use SchemaContext in its SchemaNode capacity
210 checkArgument(!(pathSteps instanceof DerefSteps), "No reference node for steps %s", pathSteps);
212 // We are missing proper API alignment, if this ever triggers
213 throw new IllegalStateException("Unsupported path " + pathSteps);
217 * Method attempts to find DataSchemaNode inside of provided Schema Context
218 * and Yang Module accordingly to Non-conditional relative Revision Aware
219 * XPath. The specified Module MUST be present in Schema Context otherwise
220 * the operation would fail and return <code>null</code>. <br>
221 * The relative Revision Aware XPath MUST be specified WITHOUT the
222 * conditional statement (i.e. without [cond]) in path, because in this
223 * state the Schema Context is completely unaware of data state and will be
224 * not able to properly resolve XPath. If the XPath contains condition the
225 * method will return IllegalArgumentException. <br>
226 * The Actual Schema Node MUST be specified correctly because from this
227 * Schema Node will search starts. If the Actual Schema Node is not correct
228 * the operation will simply fail, because it will be unable to find desired
229 * DataSchemaNode. <br>
230 * If the Revision Aware XPath doesn't have flag
231 * <code>isAbsolute == false</code> the method will throw
232 * IllegalArgumentException. <br>
233 * If the relative Revision Aware XPath is correct and desired Data Schema
234 * Node is present in Yang module or in depending module in Schema Context
235 * the method will return specified Data Schema Node, otherwise the
236 * operation will fail and method will return <code>null</code>.
242 * @param actualSchemaNode
244 * @param relativeXPath
245 * Relative Non Conditional Revision Aware XPath
246 * @return DataSchemaNode if is present in specified Schema Context for
247 * given relative Revision Aware XPath, otherwise will return
249 * @throws NullPointerException if any argument is null
251 // FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
252 // notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
255 // Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
256 // a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
257 // via a derived SchemaContext (i.e. this class would have to have a
259 // SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
261 // which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
262 // that feels like an overkill.
263 // FIXME: YANGTOOLS-1052: this is a static analysis util, move it to a dedicated class
264 public static SchemaNode findDataSchemaNodeForRelativeXPath(final SchemaContext context, final Module module,
265 final SchemaNode actualSchemaNode, final PathExpression relativeXPath) {
266 checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
267 + "for non relative Revision Aware XPath use findDataSchemaNode method");
268 return resolveRelativeXPath(context, module, relativeXPath.getOriginalString(), actualSchemaNode);
272 * Returns parent Yang Module for specified Schema Context in which Schema
273 * Node is declared. If the Schema Node is not present in Schema Context the
274 * operation will return <code>null</code>.
276 * @param context Schema Context
277 * @param schemaNode Schema Node
278 * @return Yang Module for specified Schema Context and Schema Node, if Schema Node is NOT present, the method will
279 * return <code>null</code>
280 * @throws NullPointerException if any of the arguments is null
282 public static Module findParentModule(final SchemaContext context, final SchemaNode schemaNode) {
283 final QName qname = schemaNode.getPath().getLastComponent();
284 checkState(qname != null, "Schema Path contains invalid state of path parts. "
285 + "The Schema Path MUST contain at least ONE QName which defines namespace and Local name of path.");
286 return context.findModule(qname.getModule()).orElse(null);
289 public static SchemaNode findNodeInSchemaContext(final SchemaContext context, final Iterable<QName> path) {
290 final QName current = path.iterator().next();
292 LOG.trace("Looking up module {} in context {}", current, path);
293 final Optional<Module> module = context.findModule(current.getModule());
294 if (module.isEmpty()) {
295 LOG.debug("Module {} not found", current);
299 return findNodeInModule(module.get(), path);
303 * Returns NotificationDefinition from Schema Context.
305 * @param schema SchemaContext in which lookup should be performed.
306 * @param path Schema Path of notification
307 * @return Notification schema or null, if notification is not present in schema context.
310 public static @Nullable NotificationDefinition getNotificationSchema(final @NonNull SchemaContext schema,
311 final @NonNull SchemaPath path) {
312 requireNonNull(schema, "Schema context must not be null.");
313 requireNonNull(path, "Schema path must not be null.");
314 for (final NotificationDefinition potential : schema.getNotifications()) {
315 if (path.equals(potential.getPath())) {
323 * Returns RPC Input or Output Data container from RPC definition.
325 * @param schema SchemaContext in which lookup should be performed.
326 * @param path Schema path of RPC input/output data container
327 * @return Notification schema or null, if notification is not present in schema context.
330 public static @Nullable ContainerSchemaNode getRpcDataSchema(final @NonNull SchemaContext schema,
331 final @NonNull SchemaPath path) {
332 requireNonNull(schema, "Schema context must not be null.");
333 requireNonNull(path, "Schema path must not be null.");
334 final Iterator<QName> it = path.getPathFromRoot().iterator();
335 checkArgument(it.hasNext(), "Rpc must have QName.");
336 final QName rpcName = it.next();
337 checkArgument(it.hasNext(), "input or output must be part of path.");
338 final QName inOrOut = it.next();
339 for (final RpcDefinition potential : schema.getOperations()) {
340 if (rpcName.equals(potential.getQName())) {
341 return SchemaNodeUtils.getRpcDataSchema(potential, inOrOut);
348 * Extract the identifiers of all modules and submodules which were used to create a particular SchemaContext.
350 * @param context SchemaContext to be examined
351 * @return Set of ModuleIdentifiers.
353 public static Set<SourceIdentifier> getConstituentModuleIdentifiers(final SchemaContext context) {
354 final Set<SourceIdentifier> ret = new HashSet<>();
356 for (Module module : context.getModules()) {
357 ret.add(moduleToIdentifier(module));
359 for (Module submodule : module.getSubmodules()) {
360 ret.add(moduleToIdentifier(submodule));
367 private static SourceIdentifier moduleToIdentifier(final Module module) {
368 return RevisionSourceIdentifier.create(module.getName(), module.getRevision());
371 private static SchemaNode findNodeInModule(final Module module, final Iterable<QName> path) {
372 if (!path.iterator().hasNext()) {
373 LOG.debug("No node matching {} found in node {}", path, module);
377 final QName current = path.iterator().next();
378 LOG.trace("Looking for node {} in module {}", current, module);
380 SchemaNode foundNode = null;
381 final Iterable<QName> nextPath = nextLevel(path);
383 foundNode = module.getDataChildByName(current);
384 if (foundNode != null && nextPath.iterator().hasNext()) {
385 foundNode = findNodeIn(foundNode, nextPath);
388 if (foundNode == null) {
389 foundNode = getGroupingByName(module, current);
390 if (foundNode != null && nextPath.iterator().hasNext()) {
391 foundNode = findNodeIn(foundNode, nextPath);
395 if (foundNode == null) {
396 foundNode = getRpcByName(module, current);
397 if (foundNode != null && nextPath.iterator().hasNext()) {
398 foundNode = findNodeIn(foundNode, nextPath);
402 if (foundNode == null) {
403 foundNode = getNotificationByName(module, current);
404 if (foundNode != null && nextPath.iterator().hasNext()) {
405 foundNode = findNodeIn(foundNode, nextPath);
409 if (foundNode == null) {
410 LOG.debug("No node matching {} found in node {}", path, module);
416 private static SchemaNode findNodeIn(final SchemaNode parent, final Iterable<QName> path) {
417 if (!path.iterator().hasNext()) {
418 LOG.debug("No node matching {} found in node {}", path, parent);
422 final QName current = path.iterator().next();
423 LOG.trace("Looking for node {} in node {}", current, parent);
425 SchemaNode foundNode = null;
426 final Iterable<QName> nextPath = nextLevel(path);
428 if (parent instanceof DataNodeContainer) {
429 final DataNodeContainer parentDataNodeContainer = (DataNodeContainer) parent;
431 foundNode = parentDataNodeContainer.getDataChildByName(current);
432 if (foundNode != null && nextPath.iterator().hasNext()) {
433 foundNode = findNodeIn(foundNode, nextPath);
436 if (foundNode == null) {
437 foundNode = getGroupingByName(parentDataNodeContainer, current);
438 if (foundNode != null && nextPath.iterator().hasNext()) {
439 foundNode = findNodeIn(foundNode, nextPath);
444 if (foundNode == null && parent instanceof ActionNodeContainer) {
445 foundNode = ((ActionNodeContainer) parent).getActions().stream()
446 .filter(act -> current.equals(act.getQName())).findFirst().orElse(null);
447 if (foundNode != null && nextPath.iterator().hasNext()) {
448 foundNode = findNodeIn(foundNode, nextPath);
452 if (foundNode == null && parent instanceof NotificationNodeContainer) {
453 foundNode = ((NotificationNodeContainer) parent).getNotifications().stream()
454 .filter(notif -> current.equals(notif.getQName())).findFirst().orElse(null);
455 if (foundNode != null && nextPath.iterator().hasNext()) {
456 foundNode = findNodeIn(foundNode, nextPath);
460 if (foundNode == null && parent instanceof OperationDefinition) {
461 final OperationDefinition parentRpcDefinition = (OperationDefinition) parent;
463 if (current.getLocalName().equals("input")) {
464 foundNode = parentRpcDefinition.getInput();
465 if (foundNode != null && nextPath.iterator().hasNext()) {
466 foundNode = findNodeIn(foundNode, nextPath);
470 if (current.getLocalName().equals("output")) {
471 foundNode = parentRpcDefinition.getOutput();
472 if (foundNode != null && nextPath.iterator().hasNext()) {
473 foundNode = findNodeIn(foundNode, nextPath);
477 if (foundNode == null) {
478 foundNode = getGroupingByName(parentRpcDefinition, current);
479 if (foundNode != null && nextPath.iterator().hasNext()) {
480 foundNode = findNodeIn(foundNode, nextPath);
485 if (foundNode == null && parent instanceof ChoiceSchemaNode) {
486 foundNode = ((ChoiceSchemaNode) parent).getCaseNodeByName(current);
488 if (foundNode != null && nextPath.iterator().hasNext()) {
489 foundNode = findNodeIn(foundNode, nextPath);
492 if (foundNode == null) {
493 // fallback that tries to map into one of the child cases
494 for (final CaseSchemaNode caseNode : ((ChoiceSchemaNode) parent).getCases().values()) {
495 final DataSchemaNode maybeChild = caseNode.getDataChildByName(current);
496 if (maybeChild != null) {
497 foundNode = findNodeIn(maybeChild, nextPath);
504 if (foundNode == null) {
505 LOG.debug("No node matching {} found in node {}", path, parent);
512 private static Iterable<QName> nextLevel(final Iterable<QName> path) {
513 return Iterables.skip(path, 1);
516 private static RpcDefinition getRpcByName(final Module module, final QName name) {
517 for (final RpcDefinition rpc : module.getRpcs()) {
518 if (rpc.getQName().equals(name)) {
525 private static NotificationDefinition getNotificationByName(final Module module, final QName name) {
526 for (final NotificationDefinition notification : module.getNotifications()) {
527 if (notification.getQName().equals(name)) {
534 private static GroupingDefinition getGroupingByName(final DataNodeContainer dataNodeContainer, final QName name) {
535 for (final GroupingDefinition grouping : dataNodeContainer.getGroupings()) {
536 if (grouping.getQName().equals(name)) {
543 private static GroupingDefinition getGroupingByName(final OperationDefinition rpc, final QName name) {
544 for (final GroupingDefinition grouping : rpc.getGroupings()) {
545 if (grouping.getQName().equals(name)) {
553 * Transforms string representation of XPath to Queue of QNames. The XPath
554 * is split by "/" and for each part of XPath is assigned correct module in
556 * If Schema Context, Parent Module or XPath string contains
557 * <code>null</code> values, the method will throws IllegalArgumentException
561 * @param parentModule
565 * @return return a list of QName
567 private static List<QName> xpathToQNamePath(final SchemaContext context, final Module parentModule,
568 final String xpath) {
569 final List<QName> path = new ArrayList<>();
570 for (final String pathComponent : SLASH_SPLITTER.split(xpath)) {
571 path.add(stringPathPartToQName(context, parentModule, pathComponent));
577 * Transforms part of Prefixed Path as java String to QName. <br>
578 * If the string contains module prefix separated by ":" (i.e.
579 * mod:container) this module is provided from from Parent Module list of
580 * imports. If the Prefixed module is present in Schema Context the QName
581 * can be constructed. <br>
582 * If the Prefixed Path Part does not contains prefix the Parent's Module
583 * namespace is taken for construction of QName. <br>
585 * @param context Schema Context
586 * @param parentModule Parent Module
587 * @param prefixedPathPart Prefixed Path Part string
588 * @return QName from prefixed Path Part String.
589 * @throws NullPointerException if any arguments are null
591 private static QName stringPathPartToQName(final SchemaContext context, final Module parentModule,
592 final String prefixedPathPart) {
593 requireNonNull(context, "context");
595 if (prefixedPathPart.indexOf(':') != -1) {
596 final Iterator<String> prefixedName = COLON_SPLITTER.split(prefixedPathPart).iterator();
597 final String modulePrefix = prefixedName.next();
599 final Module module = resolveModuleForPrefix(context, parentModule, modulePrefix);
600 checkArgument(module != null, "Failed to resolve xpath: no module found for prefix %s in module %s",
601 modulePrefix, parentModule.getName());
603 return QName.create(module.getQNameModule(), prefixedName.next());
606 return QName.create(parentModule.getNamespace(), parentModule.getRevision(), prefixedPathPart);
610 * Method will attempt to resolve and provide Module reference for specified module prefix. Each Yang module could
611 * contains multiple imports which MUST be associated with corresponding module prefix. The method simply looks into
612 * module imports and returns the module that is bounded with specified prefix. If the prefix is not present
613 * in module or the prefixed module is not present in specified Schema Context, the method will return {@code null}.
615 * If String prefix is the same as prefix of the specified Module the reference to this module is returned.<br>
617 * @param context Schema Context
618 * @param module Yang Module
619 * @param prefix Module Prefix
620 * @return Module for given prefix in specified Schema Context if is present, otherwise returns <code>null</code>
621 * @throws NullPointerException if any arguments are null
623 private static Module resolveModuleForPrefix(final SchemaContext context, final Module module,
624 final String prefix) {
625 requireNonNull(context, "context");
627 if (prefix.equals(module.getPrefix())) {
631 final Set<ModuleImport> imports = module.getImports();
632 for (final ModuleImport mi : imports) {
633 if (prefix.equals(mi.getPrefix())) {
634 return context.findModule(mi.getModuleName(), mi.getRevision()).orElse(null);
641 * Resolve a relative XPath into a set of QNames.
649 * @param actualSchemaNode
651 * @return target schema node
652 * @throws IllegalArgumentException if any arguments are null
654 private static @Nullable SchemaNode resolveRelativeXPath(final SchemaContext context, final Module module,
655 final String pathStr, final SchemaNode actualSchemaNode) {
656 checkState(actualSchemaNode.getPath() != null, "Schema Path reference for Leafref cannot be NULL");
658 return pathStr.startsWith("deref(") ? resolveDerefPath(context, module, actualSchemaNode, pathStr)
659 : findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
660 doSplitXPath(pathStr)));
663 private static Iterable<QName> resolveRelativePath(final SchemaContext context, final Module module,
664 final SchemaNode actualSchemaNode, final List<String> steps) {
665 // Find out how many "parent" components there are and trim them
666 final int colCount = normalizeXPath(steps);
667 final List<String> xpaths = colCount == 0 ? steps : steps.subList(colCount, steps.size());
669 final List<QName> walkablePath = createWalkablePath(actualSchemaNode.getPath().getPathFromRoot(),
672 if (walkablePath.size() - colCount >= 0) {
673 return Iterables.concat(Iterables.limit(walkablePath, walkablePath.size() - colCount),
674 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
676 return Iterables.concat(walkablePath,
677 Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
681 * Return List of qNames that are walkable using xPath. When getting a path from schema node it will return path
682 * with parents like CaseSchemaNode and ChoiceSchemaNode as well if they are parents of the node. We need to get
683 * rid of these in order to find the node that xPath is pointing to. Also we can not remove any node beyond the
684 * amount of "../" because we will not be able to find the correct schema node from schema context
686 * @param schemaNodePath list of qNames as a path to the leaf of type leafref
687 * @param context create schema context
688 * @param colCount amount of "../" in the xPath expression
689 * @return list of QNames as a path where we should be able to find referenced node
691 private static List<QName> createWalkablePath(final Iterable<QName> schemaNodePath, final SchemaContext context,
692 final int colCount) {
693 final List<Integer> indexToRemove = new ArrayList<>();
694 List<QName> schemaNodePathRet = Lists.newArrayList(schemaNodePath);
695 for (int j = 0, i = schemaNodePathRet.size() - 1; i >= 0 && j != colCount; i--, j++) {
696 final SchemaNode nodeIn = findTargetNode(context, schemaNodePathRet);
697 if (nodeIn instanceof CaseSchemaNode || nodeIn instanceof ChoiceSchemaNode) {
698 indexToRemove.add(i);
701 schemaNodePathRet.remove(i);
703 schemaNodePathRet = Lists.newArrayList(schemaNodePath);
704 for (int i : indexToRemove) {
705 schemaNodePathRet.remove(i);
707 return schemaNodePathRet;
710 private static SchemaNode resolveDerefPath(final SchemaContext context, final Module module,
711 final SchemaNode actualSchemaNode, final String xpath) {
712 final int paren = xpath.indexOf(')', 6);
713 checkArgument(paren != -1, "Cannot find matching parentheses in %s", xpath);
715 final String derefArg = xpath.substring(6, paren).strip();
716 // Look up the node which we need to reference
717 final SchemaNode derefTarget = findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
718 doSplitXPath(derefArg)));
719 checkArgument(derefTarget != null, "Cannot find deref(%s) target node %s in context of %s", derefArg,
721 checkArgument(derefTarget instanceof TypedDataSchemaNode, "deref(%s) resolved to non-typed %s", derefArg,
724 // We have a deref() target, decide what to do about it
725 final TypeDefinition<?> targetType = ((TypedDataSchemaNode) derefTarget).getType();
726 if (targetType instanceof InstanceIdentifierTypeDefinition) {
727 // Static inference breaks down, we cannot determine where this points to
728 // FIXME: dedicated exception, users can recover from it, derive from IAE
729 throw new UnsupportedOperationException("Cannot infer instance-identifier reference " + targetType);
732 // deref() is define only for instance-identifier and leafref types, handle the latter
733 checkArgument(targetType instanceof LeafrefTypeDefinition, "Illegal target type %s", targetType);
735 final PathExpression targetPath = ((LeafrefTypeDefinition) targetType).getPathStatement();
736 LOG.debug("Derefencing path {}", targetPath);
738 final SchemaNode deref = targetPath.isAbsolute()
739 ? findTargetNode(context, actualSchemaNode.getQName().getModule(),
740 ((LocationPathSteps) targetPath.getSteps()).getLocationPath())
741 : findDataSchemaNodeForRelativeXPath(context, module, actualSchemaNode, targetPath);
743 LOG.debug("Path {} could not be derefenced", targetPath);
747 checkArgument(deref instanceof LeafSchemaNode, "Unexpected %s reference in %s", deref, targetPath);
749 final List<String> qnames = doSplitXPath(xpath.substring(paren + 1).stripLeading());
750 return findTargetNode(context, resolveRelativePath(context, module, deref, qnames));
753 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final QNameModule localNamespace,
754 final YangLocationPath path) {
755 final Deque<QName> ret = new ArrayDeque<>();
756 for (Step step : path.getSteps()) {
757 if (step instanceof AxisStep) {
758 // We only support parent axis steps
759 final YangXPathAxis axis = ((AxisStep) step).getAxis();
760 checkState(axis == YangXPathAxis.PARENT, "Unexpected axis %s", axis);
765 // This has to be a QNameStep
766 checkState(step instanceof QNameStep, "Unhandled step %s in %s", step, path);
767 ret.addLast(resolve(((QNameStep) step).getQName(), localNamespace));
770 return findTargetNode(context, ret);
773 private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final Iterable<QName> qnamePath) {
774 // We do not have enough information about resolution context, hence cannot account for actions, RPCs
775 // and notifications. We therefore attempt to make a best estimate, but this can still fail.
776 final Optional<DataSchemaNode> pureData = context.findDataTreeChild(qnamePath);
777 return pureData.isPresent() ? pureData.get() : findNodeInSchemaContext(context, qnamePath);
780 private static QName resolve(final AbstractQName toResolve, final QNameModule localNamespace) {
781 if (toResolve instanceof QName) {
782 return (QName) toResolve;
783 } else if (toResolve instanceof UnqualifiedQName) {
784 return ((UnqualifiedQName) toResolve).bindTo(localNamespace);
786 throw new IllegalStateException("Unhandled step " + toResolve);
791 static int normalizeXPath(final List<String> xpath) {
792 LOG.trace("Normalize {}", xpath);
794 // We need to make multiple passes here, as the leading XPaths as we can have "../abc/../../def", which really
797 // Next up: count leading ".." components
798 int leadingParents = 0;
800 if (leadingParents == xpath.size()) {
801 return leadingParents;
803 if (!"..".equals(xpath.get(leadingParents))) {
810 // Now let's see if there there is a '..' in the rest
811 final int dots = findDots(xpath, leadingParents + 1);
813 return leadingParents;
816 xpath.remove(dots - 1);
817 xpath.remove(dots - 1);
818 LOG.trace("Next iteration {}", xpath);
822 private static int findDots(final List<String> xpath, final int startIndex) {
823 for (int i = startIndex; i < xpath.size(); ++i) {
824 if ("..".equals(xpath.get(i))) {
832 private static List<String> doSplitXPath(final String xpath) {
833 return SLASH_SPLITTER.splitToList(xpath);
837 * Extracts the base type of node on which schema node points to. If target node is again of type
838 * LeafrefTypeDefinition, methods will be call recursively until it reach concrete type definition.
840 * @param typeDefinition
841 * type of node which will be extracted
842 * @param schemaContext
846 * @return recursively found type definition this leafref is pointing to or null if the xpath is incorrect (null
847 * is there to preserve backwards compatibility)
849 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
850 final SchemaContext schemaContext, final SchemaNode schema) {
851 final PathExpression pathStatement = typeDefinition.getPathStatement();
852 final String pathStr = stripConditionsFromXPathString(pathStatement);
854 final DataSchemaNode dataSchemaNode;
855 if (pathStatement.isAbsolute()) {
856 SchemaNode baseSchema = schema;
857 while (baseSchema instanceof DerivableSchemaNode) {
858 final Optional<? extends SchemaNode> basePotential = ((DerivableSchemaNode) baseSchema).getOriginal();
859 if (basePotential.isPresent()) {
860 baseSchema = basePotential.get();
866 final Module parentModule = findParentModuleOfReferencingType(schemaContext, baseSchema);
867 dataSchemaNode = (DataSchemaNode) findTargetNode(schemaContext,
868 xpathToQNamePath(schemaContext, parentModule, pathStr));
870 Module parentModule = findParentModule(schemaContext, schema);
871 dataSchemaNode = (DataSchemaNode) resolveRelativeXPath(schemaContext, parentModule, pathStr, schema);
874 // FIXME this is just to preserve backwards compatibility since yangtools do not mind wrong leafref xpaths
875 // and current expected behaviour for such cases is to just use pure string
876 // This should throw an exception about incorrect XPath in leafref
877 if (dataSchemaNode == null) {
881 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
883 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
884 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
887 return targetTypeDefinition;
891 * Returns base type for {@code typeDefinition} which belongs to module specified via {@code qname}. This handle
892 * the case when leafref type isn't specified as type substatement of leaf or leaf-list but is defined in other
893 * module as typedef which is then imported to referenced module.
896 * Because {@code typeDefinition} is definied via typedef statement, only absolute path is meaningful.
898 public static TypeDefinition<?> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
899 final SchemaContext schemaContext, final QName qname) {
900 final PathExpression pathStatement = typeDefinition.getPathStatement();
901 if (!pathStatement.isAbsolute()) {
905 final Optional<Module> parentModule = schemaContext.findModule(qname.getModule());
906 checkArgument(parentModule.isPresent(), "Failed to find parent module for %s", qname);
908 final DataSchemaNode dataSchemaNode = (DataSchemaNode) findTargetNode(schemaContext,
909 xpathToQNamePath(schemaContext, parentModule.get(), stripConditionsFromXPathString(pathStatement)));
910 final TypeDefinition<?> targetTypeDefinition = typeDefinition(dataSchemaNode);
911 if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
912 return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
915 return targetTypeDefinition;
918 private static Module findParentModuleOfReferencingType(final SchemaContext schemaContext,
919 final SchemaNode schemaNode) {
920 checkArgument(schemaContext != null, "Schema Context reference cannot be NULL!");
921 checkArgument(schemaNode instanceof TypedDataSchemaNode, "Unsupported node %s", schemaNode);
923 TypeDefinition<?> nodeType = ((TypedDataSchemaNode) schemaNode).getType();
924 if (nodeType.getBaseType() != null) {
925 while (nodeType.getBaseType() != null) {
926 nodeType = nodeType.getBaseType();
929 return schemaContext.findModule(nodeType.getQName().getModule()).orElse(null);
932 return findParentModule(schemaContext, schemaNode);
935 private static final Pattern STRIP_PATTERN = Pattern.compile("\\[[^\\[\\]]*\\]");
938 * Removes conditions from xPath pointed to target node.
940 * @param pathStatement
941 * xPath to target node
942 * @return string representation of xPath without conditions
945 static String stripConditionsFromXPathString(final PathExpression pathStatement) {
946 return STRIP_PATTERN.matcher(pathStatement.getOriginalString()).replaceAll("");
950 * Gets the base type of DataSchemaNode value.
953 * a node representing DataSchemaNode
954 * @return concrete type definition of node value
956 private static TypeDefinition<?> typeDefinition(final DataSchemaNode node) {
957 checkArgument(node instanceof TypedDataSchemaNode, "Unhandled parameter type %s", node);
959 TypeDefinition<?> current = ((TypedDataSchemaNode) node).getType();
960 // TODO: don't we have a utility for this?
961 TypeDefinition<?> base = current.getBaseType();
962 while (base != null) {
964 base = current.getBaseType();