/*
* Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.model.util;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.yangtools.yang.common.AbstractQName;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.common.QNameModule;
import org.opendaylight.yangtools.yang.common.UnqualifiedQName;
import org.opendaylight.yangtools.yang.model.api.ActionNodeContainer;
import org.opendaylight.yangtools.yang.model.api.CaseSchemaNode;
import org.opendaylight.yangtools.yang.model.api.ChoiceSchemaNode;
import org.opendaylight.yangtools.yang.model.api.ContainerLike;
import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
import org.opendaylight.yangtools.yang.model.api.DerivableSchemaNode;
import org.opendaylight.yangtools.yang.model.api.GroupingDefinition;
import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.ModuleImport;
import org.opendaylight.yangtools.yang.model.api.ModuleLike;
import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
import org.opendaylight.yangtools.yang.model.api.NotificationNodeContainer;
import org.opendaylight.yangtools.yang.model.api.OperationDefinition;
import org.opendaylight.yangtools.yang.model.api.PathExpression;
import org.opendaylight.yangtools.yang.model.api.PathExpression.DerefSteps;
import org.opendaylight.yangtools.yang.model.api.PathExpression.LocationPathSteps;
import org.opendaylight.yangtools.yang.model.api.PathExpression.Steps;
import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.api.SchemaNode;
import org.opendaylight.yangtools.yang.model.api.SchemaPath;
import org.opendaylight.yangtools.yang.model.api.Submodule;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.TypedDataSchemaNode;
import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath;
import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.AxisStep;
import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.QNameStep;
import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Step;
import org.opendaylight.yangtools.yang.xpath.api.YangXPathAxis;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The Schema Context Util contains support methods for searching through Schema Context modules for specified schema
* nodes via Schema Path or Revision Aware XPath. The Schema Context Util is designed as mixin, so it is not
* instantiable.
*/
public final class SchemaContextUtil {
private static final Logger LOG = LoggerFactory.getLogger(SchemaContextUtil.class);
private static final Splitter COLON_SPLITTER = Splitter.on(':');
private static final Splitter SLASH_SPLITTER = Splitter.on('/').omitEmptyStrings();
private static final Pattern GROUPS_PATTERN = Pattern.compile("\\[(.*?)\\]");
private SchemaContextUtil() {
// Hidden on purpose
}
/**
* Method attempts to find DataSchemaNode in Schema Context via specified Schema Path. The returned DataSchemaNode
* from method will be the node at the end of the SchemaPath. If the DataSchemaNode is not present in the Schema
* Context the method will return {@code null}.
*
*
* In case that Schema Context or Schema Path are not specified correctly (i.e. contains {@code null} values) the
* method will throw IllegalArgumentException.
*
* @param context Schema Context
* @param schemaPath Schema Path to search for
* @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
* @throws NullPointerException if context or schemaPath is null
*/
public static SchemaNode findDataSchemaNode(final SchemaContext context, final SchemaPath schemaPath) {
final Iterable prefixedPath = schemaPath.getPathFromRoot();
if (prefixedPath == null) {
LOG.debug("Schema path {} has null path", schemaPath);
return null;
}
LOG.trace("Looking for path {} in context {}", schemaPath, context);
return findNodeInSchemaContext(context, prefixedPath);
}
/**
* Attempt to find a DataSchemaNode based on its path from root, similar to
* {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
*
* @param context Schema Context
* @param path Path to search for
* @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
* @throws NullPointerException if a any argument is null or if the path contains a null element
*/
@Beta
public static SchemaNode findDataSchemaNode(final SchemaContext context, final List path) {
return findTargetNode(context, null, YangLocationPath.absolute(
path.stream().map(YangXPathAxis.CHILD::asStep).collect(Collectors.toList())));
}
/**
* Attempt to find a DataSchemaNode based on its path from root, similar to
* {@link #findDataSchemaNode(SchemaContext, Module, PathExpression)} without requiring an expression.
*
* @param context Schema Context
* @param path Path to search for
* @return SchemaNode from the end of the Schema Path or {@code null} if the Node is not present.
* @throws NullPointerException if a any argument is null or if the path contains a null element
*/
@Beta
public static SchemaNode findDataSchemaNode(final SchemaContext context, final QName... path) {
return findDataSchemaNode(context, Arrays.asList(path));
}
/**
* Method attempts to find DataSchemaNode inside of provided Schema Context
* and Yang Module accordingly to Non-conditional Revision Aware XPath. The
* specified Module MUST be present in Schema Context otherwise the
* operation would fail and return null
.
* The Revision Aware XPath MUST be specified WITHOUT the conditional
* statement (i.e. without [cond]) in path, because in this state the Schema
* Context is completely unaware of data state and will be not able to
* properly resolve XPath. If the XPath contains condition the method will
* return IllegalArgumentException.
* If the Revision Aware XPath is correct and desired Data Schema Node is
* present in Yang module or in depending module in Schema Context the
* method will return specified Data Schema Node, otherwise the operation
* will fail and method will return null
.
*
* @param context
* Schema Context
* @param module
* Yang Module
* @param nonCondXPath
* Non Conditional Revision Aware XPath
* @return Returns Data Schema Node for specified Schema Context for given
* Non-conditional Revision Aware XPath, or null
if the
* DataSchemaNode is not present in Schema Context.
* @throws NullPointerException if any of the arguments is null
* @deprecated Use {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, YangLocationPath)} or
* {@link #findDataTreeSchemaNode(SchemaContext, QNameModule, PathExpression)} instead.
*/
// FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
// notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
// of RFC7950.
//
// Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
// a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
// via a derived SchemaContext (i.e. this class would have to have a
//
// SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
//
// which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
// that feels like an overkill.
@Deprecated
public static SchemaNode findDataSchemaNode(final SchemaContext context, final Module module,
final PathExpression nonCondXPath) {
requireNonNull(context, "context");
requireNonNull(module, "module");
final String strXPath = nonCondXPath.getOriginalString();
checkArgument(strXPath.indexOf('[') == -1, "Revision Aware XPath may not contain a condition");
if (nonCondXPath.isAbsolute()) {
return findTargetNode(context, xpathToQNamePath(context, module, strXPath));
}
return null;
}
@Beta
public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
final YangLocationPath absPath) {
checkArgument(absPath.isAbsolute(), "Unsupported relative path %s", absPath);
return findTargetNode(ctx, localModule, absPath);
}
@Beta
public static SchemaNode findDataTreeSchemaNode(final SchemaContext ctx, final QNameModule localModule,
final PathExpression absPath) {
final Steps pathSteps = absPath.getSteps();
if (pathSteps instanceof LocationPathSteps) {
return findDataTreeSchemaNode(ctx, localModule, ((LocationPathSteps) pathSteps).getLocationPath());
}
// We would need a reference schema node and no, we do not want to use SchemaContext in its SchemaNode capacity
checkArgument(!(pathSteps instanceof DerefSteps), "No reference node for steps %s", pathSteps);
// We are missing proper API alignment, if this ever triggers
throw new IllegalStateException("Unsupported path " + pathSteps);
}
/**
* Method attempts to find DataSchemaNode inside of provided Schema Context
* and Yang Module accordingly to Non-conditional relative Revision Aware
* XPath. The specified Module MUST be present in Schema Context otherwise
* the operation would fail and return null
.
* The relative Revision Aware XPath MUST be specified WITHOUT the
* conditional statement (i.e. without [cond]) in path, because in this
* state the Schema Context is completely unaware of data state and will be
* not able to properly resolve XPath. If the XPath contains condition the
* method will return IllegalArgumentException.
* The Actual Schema Node MUST be specified correctly because from this
* Schema Node will search starts. If the Actual Schema Node is not correct
* the operation will simply fail, because it will be unable to find desired
* DataSchemaNode.
* If the Revision Aware XPath doesn't have flag
* isAbsolute == false
the method will throw
* IllegalArgumentException.
* If the relative Revision Aware XPath is correct and desired Data Schema
* Node is present in Yang module or in depending module in Schema Context
* the method will return specified Data Schema Node, otherwise the
* operation will fail and method will return null
.
*
* @param context
* Schema Context
* @param module
* Yang Module
* @param actualSchemaNode
* Actual Schema Node
* @param relativeXPath
* Relative Non Conditional Revision Aware XPath
* @return DataSchemaNode if is present in specified Schema Context for
* given relative Revision Aware XPath, otherwise will return
* null
.
* @throws NullPointerException if any argument is null
*/
// FIXME: This entire method is ill-defined, as the resolution process depends on where the XPath is defined --
// notably RPCs, actions and notifications modify the data tree temporarily. See sections 6.4.1 and 9.9.2
// of RFC7950.
//
// Most notably we need to understand whether the XPath is being resolved in the data tree, or as part of
// a notification/action/RPC, as then the SchemaContext grows tentative nodes ... which could be addressed
// via a derived SchemaContext (i.e. this class would have to have a
//
// SchemaContext notificationSchemaContext(SchemaContext delegate, NotificationDefinition notif)
//
// which would then be passed in to a method similar to this one. In static contexts, like MD-SAL codegen,
// that feels like an overkill.
// FIXME: YANGTOOLS-1052: this is a static analysis util, move it to a dedicated class
public static SchemaNode findDataSchemaNodeForRelativeXPath(final SchemaContext context, final Module module,
final SchemaNode actualSchemaNode, final PathExpression relativeXPath) {
checkState(!relativeXPath.isAbsolute(), "Revision Aware XPath MUST be relative i.e. MUST contains ../, "
+ "for non relative Revision Aware XPath use findDataSchemaNode method");
return resolveRelativeXPath(context, module, removePredicatesFromXpath(relativeXPath.getOriginalString()),
actualSchemaNode);
}
private static String removePredicatesFromXpath(final String xpath) {
return GROUPS_PATTERN.matcher(xpath).replaceAll("");
}
/**
* Returns parent Yang Module for specified Schema Context in which Schema
* Node is declared. If the Schema Node is not present in Schema Context the
* operation will return null
.
*
* @param context Schema Context
* @param schemaNode Schema Node
* @return Yang Module for specified Schema Context and Schema Node, if Schema Node is NOT present, the method will
* return null
* @throws NullPointerException if any of the arguments is null
*/
public static Module findParentModule(final SchemaContext context, final SchemaNode schemaNode) {
final QName qname = schemaNode.getPath().getLastComponent();
checkState(qname != null, "Schema Path contains invalid state of path parts. "
+ "The Schema Path MUST contain at least ONE QName which defines namespace and Local name of path.");
return context.findModule(qname.getModule()).orElse(null);
}
public static SchemaNode findNodeInSchemaContext(final SchemaContext context, final Iterable path) {
final QName current = path.iterator().next();
LOG.trace("Looking up module {} in context {}", current, path);
final Optional module = context.findModule(current.getModule());
if (module.isEmpty()) {
LOG.debug("Module {} not found", current);
return null;
}
return findNodeInModule(module.get(), path);
}
/**
* Returns NotificationDefinition from Schema Context.
*
* @param schema SchemaContext in which lookup should be performed.
* @param path Schema Path of notification
* @return Notification schema or null, if notification is not present in schema context.
*/
@Beta
public static @Nullable NotificationDefinition getNotificationSchema(final @NonNull SchemaContext schema,
final @NonNull SchemaPath path) {
requireNonNull(schema, "Schema context must not be null.");
requireNonNull(path, "Schema path must not be null.");
for (final NotificationDefinition potential : schema.getNotifications()) {
if (path.equals(potential.getPath())) {
return potential;
}
}
return null;
}
/**
* Returns RPC Input or Output Data container from RPC definition.
*
* @param schema SchemaContext in which lookup should be performed.
* @param path Schema path of RPC input/output data container
* @return Notification schema or null, if notification is not present in schema context.
*/
@Beta
public static @Nullable ContainerLike getRpcDataSchema(final @NonNull SchemaContext schema,
final @NonNull SchemaPath path) {
requireNonNull(schema, "Schema context must not be null.");
requireNonNull(path, "Schema path must not be null.");
final Iterator it = path.getPathFromRoot().iterator();
checkArgument(it.hasNext(), "Rpc must have QName.");
final QName rpcName = it.next();
checkArgument(it.hasNext(), "input or output must be part of path.");
final QName inOrOut = it.next();
for (final RpcDefinition potential : schema.getOperations()) {
if (rpcName.equals(potential.getQName())) {
return SchemaNodeUtils.getRpcDataSchema(potential, inOrOut);
}
}
return null;
}
/**
* Extract the identifiers of all modules and submodules which were used to create a particular SchemaContext.
*
* @param context SchemaContext to be examined
* @return Set of ModuleIdentifiers.
*/
public static Set getConstituentModuleIdentifiers(final SchemaContext context) {
final Set ret = new HashSet<>();
for (Module module : context.getModules()) {
ret.add(moduleToIdentifier(module));
for (Submodule submodule : module.getSubmodules()) {
ret.add(moduleToIdentifier(submodule));
}
}
return ret;
}
private static SourceIdentifier moduleToIdentifier(final ModuleLike module) {
return RevisionSourceIdentifier.create(module.getName(), module.getRevision());
}
private static SchemaNode findNodeInModule(final Module module, final Iterable path) {
if (!path.iterator().hasNext()) {
LOG.debug("No node matching {} found in node {}", path, module);
return null;
}
final QName current = path.iterator().next();
LOG.trace("Looking for node {} in module {}", current, module);
SchemaNode foundNode = null;
final Iterable nextPath = nextLevel(path);
foundNode = module.dataChildByName(current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
if (foundNode == null) {
foundNode = getGroupingByName(module, current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (foundNode == null) {
foundNode = getRpcByName(module, current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (foundNode == null) {
foundNode = getNotificationByName(module, current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (foundNode == null) {
LOG.debug("No node matching {} found in node {}", path, module);
}
return foundNode;
}
private static SchemaNode findNodeIn(final SchemaNode parent, final Iterable path) {
if (!path.iterator().hasNext()) {
LOG.debug("No node matching {} found in node {}", path, parent);
return null;
}
final QName current = path.iterator().next();
LOG.trace("Looking for node {} in node {}", current, parent);
SchemaNode foundNode = null;
final Iterable nextPath = nextLevel(path);
if (parent instanceof DataNodeContainer) {
final DataNodeContainer parentDataNodeContainer = (DataNodeContainer) parent;
foundNode = parentDataNodeContainer.dataChildByName(current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
if (foundNode == null) {
foundNode = getGroupingByName(parentDataNodeContainer, current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
}
if (foundNode == null && parent instanceof ActionNodeContainer) {
final Optional extends SchemaNode> next = ((ActionNodeContainer) parent).getActions().stream()
.filter(act -> current.equals(act.getQName())).findFirst();
if (next.isPresent() && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(next.orElseThrow(), nextPath);
}
}
if (foundNode == null && parent instanceof NotificationNodeContainer) {
foundNode = ((NotificationNodeContainer) parent).getNotifications().stream()
.filter(notif -> current.equals(notif.getQName())).findFirst().orElse(null);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (foundNode == null && parent instanceof OperationDefinition) {
final OperationDefinition parentRpcDefinition = (OperationDefinition) parent;
if (current.getLocalName().equals("input")) {
foundNode = parentRpcDefinition.getInput();
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (current.getLocalName().equals("output")) {
foundNode = parentRpcDefinition.getOutput();
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
if (foundNode == null) {
foundNode = getGroupingByName(parentRpcDefinition, current);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
}
}
if (foundNode == null && parent instanceof ChoiceSchemaNode) {
foundNode = ((ChoiceSchemaNode) parent).findCase(current).orElse(null);
if (foundNode != null && nextPath.iterator().hasNext()) {
foundNode = findNodeIn(foundNode, nextPath);
}
if (foundNode == null) {
// fallback that tries to map into one of the child cases
for (final CaseSchemaNode caseNode : ((ChoiceSchemaNode) parent).getCases()) {
final DataSchemaNode maybeChild = caseNode.dataChildByName(current);
if (maybeChild != null) {
foundNode = findNodeIn(maybeChild, nextPath);
break;
}
}
}
}
if (foundNode == null) {
LOG.debug("No node matching {} found in node {}", path, parent);
}
return foundNode;
}
private static Iterable nextLevel(final Iterable path) {
return Iterables.skip(path, 1);
}
private static RpcDefinition getRpcByName(final Module module, final QName name) {
for (final RpcDefinition rpc : module.getRpcs()) {
if (rpc.getQName().equals(name)) {
return rpc;
}
}
return null;
}
private static NotificationDefinition getNotificationByName(final Module module, final QName name) {
for (final NotificationDefinition notification : module.getNotifications()) {
if (notification.getQName().equals(name)) {
return notification;
}
}
return null;
}
private static GroupingDefinition getGroupingByName(final DataNodeContainer dataNodeContainer, final QName name) {
for (final GroupingDefinition grouping : dataNodeContainer.getGroupings()) {
if (grouping.getQName().equals(name)) {
return grouping;
}
}
return null;
}
private static GroupingDefinition getGroupingByName(final OperationDefinition rpc, final QName name) {
for (final GroupingDefinition grouping : rpc.getGroupings()) {
if (grouping.getQName().equals(name)) {
return grouping;
}
}
return null;
}
/**
* Transforms string representation of XPath to Queue of QNames. The XPath
* is split by "/" and for each part of XPath is assigned correct module in
* Schema Path.
* If Schema Context, Parent Module or XPath string contains
* null
values, the method will throws IllegalArgumentException
*
* @param context
* Schema Context
* @param parentModule
* Parent Module
* @param xpath
* XPath String
* @return return a list of QName
*/
private static List xpathToQNamePath(final SchemaContext context, final Module parentModule,
final String xpath) {
final List path = new ArrayList<>();
for (final String pathComponent : SLASH_SPLITTER.split(xpath)) {
path.add(stringPathPartToQName(context, parentModule, pathComponent));
}
return path;
}
/**
* Transforms part of Prefixed Path as java String to QName.
* If the string contains module prefix separated by ":" (i.e.
* mod:container) this module is provided from from Parent Module list of
* imports. If the Prefixed module is present in Schema Context the QName
* can be constructed.
* If the Prefixed Path Part does not contains prefix the Parent's Module
* namespace is taken for construction of QName.
*
* @param context Schema Context
* @param parentModule Parent Module
* @param prefixedPathPart Prefixed Path Part string
* @return QName from prefixed Path Part String.
* @throws NullPointerException if any arguments are null
*/
private static QName stringPathPartToQName(final SchemaContext context, final Module parentModule,
final String prefixedPathPart) {
requireNonNull(context, "context");
if (prefixedPathPart.indexOf(':') != -1) {
final Iterator prefixedName = COLON_SPLITTER.split(prefixedPathPart).iterator();
final String modulePrefix = prefixedName.next();
final Module module = resolveModuleForPrefix(context, parentModule, modulePrefix);
checkArgument(module != null, "Failed to resolve xpath: no module found for prefix %s in module %s",
modulePrefix, parentModule.getName());
return QName.create(module.getQNameModule(), prefixedName.next());
}
return QName.create(parentModule.getQNameModule(), prefixedPathPart);
}
/**
* Method will attempt to resolve and provide Module reference for specified module prefix. Each Yang module could
* contains multiple imports which MUST be associated with corresponding module prefix. The method simply looks into
* module imports and returns the module that is bounded with specified prefix. If the prefix is not present
* in module or the prefixed module is not present in specified Schema Context, the method will return {@code null}.
*
* If String prefix is the same as prefix of the specified Module the reference to this module is returned.
*
* @param context Schema Context
* @param module Yang Module
* @param prefix Module Prefix
* @return Module for given prefix in specified Schema Context if is present, otherwise returns null
* @throws NullPointerException if any arguments are null
*/
private static Module resolveModuleForPrefix(final SchemaContext context, final Module module,
final String prefix) {
requireNonNull(context, "context");
if (prefix.equals(module.getPrefix())) {
return module;
}
for (final ModuleImport mi : module.getImports()) {
if (prefix.equals(mi.getPrefix())) {
return context.findModule(mi.getModuleName(), mi.getRevision()).orElse(null);
}
}
return null;
}
/**
* Resolve a relative XPath into a set of QNames.
*
* @param context
* Schema Context
* @param module
* Yang Module
* @param pathStr
* xPath of leafref
* @param actualSchemaNode
* actual schema node
* @return target schema node
* @throws IllegalArgumentException if any arguments are null
*/
private static @Nullable SchemaNode resolveRelativeXPath(final SchemaContext context, final Module module,
final String pathStr, final SchemaNode actualSchemaNode) {
checkState(actualSchemaNode.getPath() != null, "Schema Path reference for Leafref cannot be NULL");
return pathStr.startsWith("deref(") ? resolveDerefPath(context, module, actualSchemaNode, pathStr)
: findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
doSplitXPath(pathStr)));
}
private static Iterable resolveRelativePath(final SchemaContext context, final Module module,
final SchemaNode actualSchemaNode, final List steps) {
// Find out how many "parent" components there are and trim them
final int colCount = normalizeXPath(steps);
final List xpaths = colCount == 0 ? steps : steps.subList(colCount, steps.size());
final List walkablePath = createWalkablePath(actualSchemaNode.getPath().getPathFromRoot(),
context, colCount);
if (walkablePath.size() - colCount >= 0) {
return Iterables.concat(Iterables.limit(walkablePath, walkablePath.size() - colCount),
Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
}
return Iterables.concat(walkablePath,
Iterables.transform(xpaths, input -> stringPathPartToQName(context, module, input)));
}
/**
* Return List of qNames that are walkable using xPath. When getting a path from schema node it will return path
* with parents like CaseSchemaNode and ChoiceSchemaNode as well if they are parents of the node. We need to get
* rid of these in order to find the node that xPath is pointing to. Also we can not remove any node beyond the
* amount of "../" because we will not be able to find the correct schema node from schema context
*
* @param schemaNodePath list of qNames as a path to the leaf of type leafref
* @param context create schema context
* @param colCount amount of "../" in the xPath expression
* @return list of QNames as a path where we should be able to find referenced node
*/
private static List createWalkablePath(final Iterable schemaNodePath, final SchemaContext context,
final int colCount) {
final List indexToRemove = new ArrayList<>();
List schemaNodePathRet = Lists.newArrayList(schemaNodePath);
for (int j = 0, i = schemaNodePathRet.size() - 1; i >= 0 && j != colCount; i--, j++) {
final SchemaNode nodeIn = findTargetNode(context, schemaNodePathRet);
if (nodeIn instanceof CaseSchemaNode || nodeIn instanceof ChoiceSchemaNode) {
indexToRemove.add(i);
j--;
}
schemaNodePathRet.remove(i);
}
schemaNodePathRet = Lists.newArrayList(schemaNodePath);
for (int i : indexToRemove) {
schemaNodePathRet.remove(i);
}
return schemaNodePathRet;
}
private static SchemaNode resolveDerefPath(final SchemaContext context, final Module module,
final SchemaNode actualSchemaNode, final String xpath) {
final int paren = xpath.indexOf(')', 6);
checkArgument(paren != -1, "Cannot find matching parentheses in %s", xpath);
final String derefArg = xpath.substring(6, paren).strip();
// Look up the node which we need to reference
final SchemaNode derefTarget = findTargetNode(context, resolveRelativePath(context, module, actualSchemaNode,
doSplitXPath(derefArg)));
checkArgument(derefTarget != null, "Cannot find deref(%s) target node %s in context of %s", derefArg,
actualSchemaNode);
checkArgument(derefTarget instanceof TypedDataSchemaNode, "deref(%s) resolved to non-typed %s", derefArg,
derefTarget);
// We have a deref() target, decide what to do about it
final TypeDefinition> targetType = ((TypedDataSchemaNode) derefTarget).getType();
if (targetType instanceof InstanceIdentifierTypeDefinition) {
// Static inference breaks down, we cannot determine where this points to
// FIXME: dedicated exception, users can recover from it, derive from IAE
throw new UnsupportedOperationException("Cannot infer instance-identifier reference " + targetType);
}
// deref() is define only for instance-identifier and leafref types, handle the latter
checkArgument(targetType instanceof LeafrefTypeDefinition, "Illegal target type %s", targetType);
final PathExpression targetPath = ((LeafrefTypeDefinition) targetType).getPathStatement();
LOG.debug("Derefencing path {}", targetPath);
final SchemaNode deref = targetPath.isAbsolute()
? findTargetNode(context, actualSchemaNode.getQName().getModule(),
((LocationPathSteps) targetPath.getSteps()).getLocationPath())
: findDataSchemaNodeForRelativeXPath(context, module, actualSchemaNode, targetPath);
if (deref == null) {
LOG.debug("Path {} could not be derefenced", targetPath);
return null;
}
checkArgument(deref instanceof LeafSchemaNode, "Unexpected %s reference in %s", deref, targetPath);
final List qnames = doSplitXPath(xpath.substring(paren + 1).stripLeading());
return findTargetNode(context, resolveRelativePath(context, module, deref, qnames));
}
private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final QNameModule localNamespace,
final YangLocationPath path) {
final Deque ret = new ArrayDeque<>();
for (Step step : path.getSteps()) {
if (step instanceof AxisStep) {
// We only support parent axis steps
final YangXPathAxis axis = ((AxisStep) step).getAxis();
checkState(axis == YangXPathAxis.PARENT, "Unexpected axis %s", axis);
ret.removeLast();
continue;
}
// This has to be a QNameStep
checkState(step instanceof QNameStep, "Unhandled step %s in %s", step, path);
ret.addLast(resolve(((QNameStep) step).getQName(), localNamespace));
}
return findTargetNode(context, ret);
}
private static @Nullable SchemaNode findTargetNode(final SchemaContext context, final Iterable qnamePath) {
// We do not have enough information about resolution context, hence cannot account for actions, RPCs
// and notifications. We therefore attempt to make a best estimate, but this can still fail.
final Optional pureData = context.findDataTreeChild(qnamePath);
return pureData.isPresent() ? pureData.get() : findNodeInSchemaContext(context, qnamePath);
}
private static QName resolve(final AbstractQName toResolve, final QNameModule localNamespace) {
if (toResolve instanceof QName) {
return (QName) toResolve;
} else if (toResolve instanceof UnqualifiedQName) {
return ((UnqualifiedQName) toResolve).bindTo(localNamespace);
} else {
throw new IllegalStateException("Unhandled step " + toResolve);
}
}
@VisibleForTesting
static int normalizeXPath(final List xpath) {
LOG.trace("Normalize {}", xpath);
// We need to make multiple passes here, as the leading XPaths as we can have "../abc/../../def", which really
// is "../../def"
while (true) {
// Next up: count leading ".." components
int leadingParents = 0;
while (true) {
if (leadingParents == xpath.size()) {
return leadingParents;
}
if (!"..".equals(xpath.get(leadingParents))) {
break;
}
++leadingParents;
}
// Now let's see if there there is a '..' in the rest
final int dots = findDots(xpath, leadingParents + 1);
if (dots == -1) {
return leadingParents;
}
xpath.remove(dots - 1);
xpath.remove(dots - 1);
LOG.trace("Next iteration {}", xpath);
}
}
private static int findDots(final List xpath, final int startIndex) {
for (int i = startIndex; i < xpath.size(); ++i) {
if ("..".equals(xpath.get(i))) {
return i;
}
}
return -1;
}
private static List doSplitXPath(final String xpath) {
final List ret = new ArrayList<>();
for (String str : SLASH_SPLITTER.split(xpath)) {
ret.add(str);
}
return ret;
}
/**
* Extracts the base type of node on which schema node points to. If target node is again of type
* LeafrefTypeDefinition, methods will be call recursively until it reach concrete type definition.
*
* @param typeDefinition
* type of node which will be extracted
* @param schemaContext
* Schema Context
* @param schema
* Schema Node
* @return recursively found type definition this leafref is pointing to or null if the xpath is incorrect (null
* is there to preserve backwards compatibility)
*/
public static TypeDefinition> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
final SchemaContext schemaContext, final SchemaNode schema) {
final PathExpression pathStatement = typeDefinition.getPathStatement();
final String pathStr = stripConditionsFromXPathString(pathStatement);
final DataSchemaNode dataSchemaNode;
if (pathStatement.isAbsolute()) {
SchemaNode baseSchema = schema;
while (baseSchema instanceof DerivableSchemaNode) {
final Optional extends SchemaNode> basePotential = ((DerivableSchemaNode) baseSchema).getOriginal();
if (basePotential.isPresent()) {
baseSchema = basePotential.get();
} else {
break;
}
}
final Module parentModule = findParentModuleOfReferencingType(schemaContext, baseSchema);
dataSchemaNode = (DataSchemaNode) findTargetNode(schemaContext,
xpathToQNamePath(schemaContext, parentModule, pathStr));
} else {
Module parentModule = findParentModule(schemaContext, schema);
dataSchemaNode = (DataSchemaNode) resolveRelativeXPath(schemaContext, parentModule, pathStr, schema);
}
// FIXME this is just to preserve backwards compatibility since yangtools do not mind wrong leafref xpaths
// and current expected behaviour for such cases is to just use pure string
// This should throw an exception about incorrect XPath in leafref
if (dataSchemaNode == null) {
return null;
}
final TypeDefinition> targetTypeDefinition = typeDefinition(dataSchemaNode);
if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
}
return targetTypeDefinition;
}
/**
* Returns base type for {@code typeDefinition} which belongs to module specified via {@code qname}. This handle
* the case when leafref type isn't specified as type substatement of leaf or leaf-list but is defined in other
* module as typedef which is then imported to referenced module.
*
*
* Because {@code typeDefinition} is definied via typedef statement, only absolute path is meaningful.
*/
public static TypeDefinition> getBaseTypeForLeafRef(final LeafrefTypeDefinition typeDefinition,
final SchemaContext schemaContext, final QName qname) {
final PathExpression pathStatement = typeDefinition.getPathStatement();
if (!pathStatement.isAbsolute()) {
return null;
}
final Optional parentModule = schemaContext.findModule(qname.getModule());
checkArgument(parentModule.isPresent(), "Failed to find parent module for %s", qname);
final DataSchemaNode dataSchemaNode = (DataSchemaNode) findTargetNode(schemaContext,
xpathToQNamePath(schemaContext, parentModule.get(), stripConditionsFromXPathString(pathStatement)));
final TypeDefinition> targetTypeDefinition = typeDefinition(dataSchemaNode);
if (targetTypeDefinition instanceof LeafrefTypeDefinition) {
return getBaseTypeForLeafRef((LeafrefTypeDefinition) targetTypeDefinition, schemaContext, dataSchemaNode);
}
return targetTypeDefinition;
}
private static Module findParentModuleOfReferencingType(final SchemaContext schemaContext,
final SchemaNode schemaNode) {
checkArgument(schemaContext != null, "Schema Context reference cannot be NULL!");
checkArgument(schemaNode instanceof TypedDataSchemaNode, "Unsupported node %s", schemaNode);
TypeDefinition> nodeType = ((TypedDataSchemaNode) schemaNode).getType();
if (nodeType.getBaseType() != null) {
while (nodeType.getBaseType() != null) {
nodeType = nodeType.getBaseType();
}
return schemaContext.findModule(nodeType.getQName().getModule()).orElse(null);
}
return findParentModule(schemaContext, schemaNode);
}
private static final Pattern STRIP_PATTERN = Pattern.compile("\\[[^\\[\\]]*\\]");
/**
* Removes conditions from xPath pointed to target node.
*
* @param pathStatement
* xPath to target node
* @return string representation of xPath without conditions
*/
@VisibleForTesting
static String stripConditionsFromXPathString(final PathExpression pathStatement) {
return STRIP_PATTERN.matcher(pathStatement.getOriginalString()).replaceAll("");
}
/**
* Gets the base type of DataSchemaNode value.
*
* @param node
* a node representing DataSchemaNode
* @return concrete type definition of node value
*/
private static TypeDefinition> typeDefinition(final DataSchemaNode node) {
checkArgument(node instanceof TypedDataSchemaNode, "Unhandled parameter type %s", node);
TypeDefinition> current = ((TypedDataSchemaNode) node).getType();
// TODO: don't we have a utility for this?
TypeDefinition> base = current.getBaseType();
while (base != null) {
current = base;
base = current.getBaseType();
}
return current;
}
}