2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
3 * This program and the accompanying materials are made available under the
4 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
5 * and is available at http://www.eclipse.org/legal/epl-v10.html
7 package org.opendaylight.yangtools.yang.data.api;
9 import com.google.common.base.Optional;
10 import com.google.common.base.Preconditions;
11 import com.google.common.collect.ImmutableList;
12 import com.google.common.collect.ImmutableMap;
13 import com.google.common.collect.ImmutableSet;
14 import com.google.common.collect.Iterables;
15 import com.google.common.collect.Lists;
17 import java.io.Serializable;
18 import java.lang.reflect.Array;
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.Collections;
22 import java.util.Iterator;
23 import java.util.List;
25 import java.util.Map.Entry;
26 import java.util.Objects;
29 import org.opendaylight.yangtools.concepts.Builder;
30 import org.opendaylight.yangtools.concepts.Immutable;
31 import org.opendaylight.yangtools.concepts.Path;
32 import org.opendaylight.yangtools.util.HashCodeBuilder;
33 import org.opendaylight.yangtools.yang.common.QName;
34 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
37 * Unique identifier of a particular node instance in the data tree.
40 * Java representation of YANG Built-in type <code>instance-identifier</code>,
41 * which conceptually is XPath expression minimized to uniquely identify element
42 * in data tree which conforms to constraints maintained by YANG Model,
43 * effectively this makes Instance Identifier a path to element in data tree.
45 * Constraints put in YANG specification on instance-identifier allowed it to be
46 * effectively represented in Java and it's evaluation does not require
47 * full-blown XPath processor.
49 * <h3>Path Arguments</h3>
50 * Path to the node represented in instance identifier consists of
51 * {@link PathArgument} which carries necessary information to uniquely identify
52 * node on particular level in the subtree.
55 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
56 * <code>0..1</code> in particular subtree in data tree.</li>
57 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
58 * which has cardinality <code>0..n</code>.</li>
59 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
60 * <code>leaf-list</code> node.</li>
61 * <li>{@link AugmentationIdentifier} - Identifier of instance of
62 * <code>augmentation</code> node.</li>
66 * @see http://tools.ietf.org/html/rfc6020#section-9.13
68 public final class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
69 private static final YangInstanceIdentifier EMPTY = trustedCreate(Collections.<PathArgument>emptyList());
71 private static final long serialVersionUID = 2L;
72 private final Iterable<PathArgument> pathArguments;
73 private final int hash;
75 private transient volatile ImmutableList<PathArgument> legacyPath = null;
76 private transient volatile String toStringCache = null;
78 private final ImmutableList<PathArgument> getLegacyPath() {
79 // Temporary variable saves a volatile read
80 ImmutableList<PathArgument> ret = legacyPath;
83 // We could have used a synchronized block, but let's just not bother
84 ret = ImmutableList.copyOf(pathArguments);
93 * Returns a list of path arguments.
95 * @deprecated Use {@link #getPathArguments()} instead.
96 * @return Immutable list of path arguments.
99 public List<PathArgument> getPath() {
100 return getLegacyPath();
104 * Returns an ordered iteration of path arguments.
106 * @return Immutable iteration of path arguments.
108 public Iterable<PathArgument> getPathArguments() {
109 return pathArguments;
113 * Returns an iterable of path arguments in reverse order. This is useful
114 * when walking up a tree organized this way.
116 * @return Immutable iterable of path arguments in reverse order.
118 public Iterable<PathArgument> getReversePathArguments() {
119 return getLegacyPath().reverse();
123 * Returns the last PathArgument. This is equivalent of iterating
124 * to the last element of the iterable returned by {@link #getPathArguments()}.
126 * @return The last past argument, or null if there are no PathArguments.
128 public PathArgument getLastPathArgument() {
129 return Iterables.getFirst(getReversePathArguments(), null);
132 private YangInstanceIdentifier(final Iterable<PathArgument> path, final int hash) {
133 this.pathArguments = Preconditions.checkNotNull(path, "path must not be null.");
137 private static final YangInstanceIdentifier trustedCreate(final Iterable<PathArgument> path) {
138 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
139 for (PathArgument a : path) {
143 return new YangInstanceIdentifier(path, hash.toInstance());
146 public static final YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
147 if (Iterables.isEmpty(path)) {
151 return trustedCreate(ImmutableList.copyOf(path));
154 public static final YangInstanceIdentifier create(final PathArgument... path) {
155 // We are forcing a copy, since we cannot trust the user
156 return create(Arrays.asList(path));
160 public int hashCode() {
162 * The caching is safe, since the object contract requires
163 * immutability of the object and all objects referenced from this
165 * Used lists, maps are immutable. Path Arguments (elements) are also
166 * immutable, since the PathArgument contract requires immutability.
172 public boolean equals(final Object obj) {
179 if (getClass() != obj.getClass()) {
182 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
183 if (this.hashCode() != obj.hashCode()) {
186 return Iterables.elementsEqual(pathArguments, other.pathArguments);
190 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
192 * @param name QName of {@link NodeIdentifier}
193 * @return Instance Identifier with additional path argument added to the end.
195 public YangInstanceIdentifier node(final QName name) {
196 return node(new NodeIdentifier(name));
201 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
203 * @param arg Path argument which should be added to the end
204 * @return Instance Identifier with additional path argument added to the end.
206 public YangInstanceIdentifier node(final PathArgument arg) {
207 return new YangInstanceIdentifier(Iterables.concat(pathArguments, Collections.singleton(arg)), HashCodeBuilder.nextHashCode(hash, arg));
211 * Get the relative path from an ancestor. This method attempts to perform
212 * the reverse of concatenating a base (ancestor) and a path.
215 * Ancestor against which the relative path should be calculated
216 * @return This object's relative path from parent, or Optional.absent() if
217 * the specified parent is not in fact an ancestor of this object.
219 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
220 final Iterator<?> lit = pathArguments.iterator();
221 final Iterator<?> oit = ancestor.pathArguments.iterator();
224 while (oit.hasNext()) {
225 // Ancestor is not really an ancestor
226 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
227 return Optional.absent();
234 return Optional.of(this);
236 if (!lit.hasNext()) {
237 return Optional.of(EMPTY);
239 return Optional.of(trustedCreate(Iterables.skip(pathArguments, common)));
242 private static int hashCode(final Object value) {
247 if (value.getClass().equals(byte[].class)) {
248 return Arrays.hashCode((byte[]) value);
251 if (value.getClass().isArray()) {
253 int length = Array.getLength(value);
254 for (int i = 0; i < length; i++) {
255 hash += Objects.hashCode(Array.get(value, i));
261 return Objects.hashCode(value);
264 // Static factories & helpers
268 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
270 * @param name QName of first node identifier
271 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
273 public static YangInstanceIdentifier of(final QName name) {
274 return create(new NodeIdentifier(name));
279 * Returns new builder for InstanceIdentifier with empty path arguments.
281 * @return new builder for InstanceIdentifier with empty path arguments.
283 static public InstanceIdentifierBuilder builder() {
284 return new BuilderImpl();
289 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
291 * @param origin Instace Identifier from which path arguments are copied.
292 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
294 static public InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
295 return new BuilderImpl(origin.getPathArguments(), origin.hashCode());
299 * Returns new builder for InstanceIdentifier with first path argument set to {@link NodeIdentifier}.
301 * @param node QName of first {@link NodeIdentifier} path argument.
302 * @return new builder for InstanceIdentifier with first path argument set to {@link NodeIdentifier}.
304 * @deprecated Either use {@link #node(QName)} or instantiate an intermediate builder.
307 public static InstanceIdentifierBuilder builder(final QName node) {
308 return builder().node(node);
312 * Path argument / component of InstanceIdentifier
314 * Path argument uniquelly identifies node in data tree on particular
317 * This interface itself is used as common parent for actual
318 * path arguments types and should not be implemented by user code.
320 * Path arguments SHOULD contain only minimum of information
321 * required to uniquely identify node on particular subtree level.
323 * For actual path arguments types see:
325 * <li>{@link NodeIdentifier} - Identifier of container or leaf
326 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
327 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
328 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
331 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
333 * If applicable returns unique QName of data node as defined in YANG
336 * This method may return null, if the corresponding schema node, does
337 * not have QName associated, such as in cases of augmentations.
344 private static abstract class AbstractPathArgument implements PathArgument {
345 private static final long serialVersionUID = -4546547994250849340L;
346 private final QName nodeType;
348 protected AbstractPathArgument(final QName nodeType) {
349 this.nodeType = Preconditions.checkNotNull(nodeType);
353 public final QName getNodeType() {
358 public int compareTo(final PathArgument o) {
359 return nodeType.compareTo(o.getNodeType());
363 public int hashCode() {
364 return 31 + getNodeType().hashCode();
368 public boolean equals(final Object obj) {
372 if (obj == null || this.getClass() != obj.getClass()) {
376 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
380 public String toString() {
381 return getNodeType().toString();
387 * Fluent Builder of Instance Identifier instances
392 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
394 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
396 * @param nodeType QName of {@link NodeIdentifier} which will be added
397 * @return this builder
399 InstanceIdentifierBuilder node(QName nodeType);
402 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
404 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
405 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
406 * @return this builder
408 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
411 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
413 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
414 * @param key QName of key which will be added
415 * @param value value of key which will be added
416 * @return this builder
418 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
422 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
424 * @return {@link YangInstanceIdentifier}
426 YangInstanceIdentifier build();
430 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
431 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
433 public static final class NodeIdentifier extends AbstractPathArgument {
434 private static final long serialVersionUID = -2255888212390871347L;
436 public NodeIdentifier(final QName node) {
442 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
445 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
446 private static final long serialVersionUID = -4787195606494761540L;
448 private final Map<QName, Object> keyValues;
450 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
452 this.keyValues = ImmutableMap.copyOf(keyValues);
455 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
456 this(node, ImmutableMap.of(key, value));
459 public Map<QName, Object> getKeyValues() {
464 public int hashCode() {
465 final int prime = 31;
466 int result = super.hashCode();
467 result = prime * result;
469 for (Entry<QName, Object> entry : keyValues.entrySet()) {
470 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
476 public boolean equals(final Object obj) {
477 if (!super.equals(obj)) {
481 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
482 if (keyValues.size() != otherKeyValues.size()) {
486 for (Entry<QName, Object> entry : keyValues.entrySet()) {
487 if (!otherKeyValues.containsKey(entry.getKey())
488 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
498 public String toString() {
499 return super.toString() + '[' + keyValues + ']';
504 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
507 public static final class NodeWithValue extends AbstractPathArgument {
508 private static final long serialVersionUID = -3637456085341738431L;
510 private final Object value;
512 public NodeWithValue(final QName node, final Object value) {
517 public Object getValue() {
522 public int hashCode() {
523 final int prime = 31;
524 int result = super.hashCode();
525 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
530 public boolean equals(final Object obj) {
531 if (!super.equals(obj)) {
534 final NodeWithValue other = (NodeWithValue) obj;
535 return Objects.deepEquals(value, other.value);
539 public String toString() {
540 return super.toString() + '[' + value + ']';
545 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
546 * particular subtree.
548 * Augmentation is uniquely identified by set of all possible child nodes.
550 * to identify instance of augmentation,
551 * since RFC6020 states that <code>augment</code> that augment
552 * statement must not add multiple nodes from same namespace
553 * / module to the target node.
556 * @see http://tools.ietf.org/html/rfc6020#section-7.15
558 public static final class AugmentationIdentifier implements PathArgument {
559 private static final long serialVersionUID = -8122335594681936939L;
560 private final ImmutableSet<QName> childNames;
563 public QName getNodeType() {
564 // This should rather throw exception than return always null
565 throw new UnsupportedOperationException("Augmentation node has no QName");
570 * Construct new augmentation identifier using supplied set of possible
574 * Set of possible child nodes.
576 public AugmentationIdentifier(final Set<QName> childNames) {
577 this.childNames = ImmutableSet.copyOf(childNames);
581 * Augmentation node has no QName
584 * {@link AugmentationIdentifier#AugmentationIdentifier(Set)}
588 public AugmentationIdentifier(final QName nodeType, final Set<QName> childNames) {
594 * Returns set of all possible child nodes
596 * @return set of all possible child nodes.
598 public Set<QName> getPossibleChildNames() {
603 public String toString() {
604 final StringBuffer sb = new StringBuffer("AugmentationIdentifier{");
605 sb.append("childNames=").append(childNames).append('}');
606 return sb.toString();
610 public boolean equals(final Object o) {
614 if (!(o instanceof AugmentationIdentifier)) {
618 AugmentationIdentifier that = (AugmentationIdentifier) o;
619 return childNames.equals(that.childNames);
623 public int hashCode() {
624 return childNames.hashCode();
628 public int compareTo(final PathArgument o) {
629 if (!(o instanceof AugmentationIdentifier)) {
632 AugmentationIdentifier other = (AugmentationIdentifier) o;
633 Set<QName> otherChildNames = other.getPossibleChildNames();
634 int thisSize = childNames.size();
635 int otherSize = otherChildNames.size();
636 if (thisSize == otherSize) {
637 Iterator<QName> otherIterator = otherChildNames.iterator();
638 for (QName name : childNames) {
639 int c = name.compareTo(otherIterator.next());
645 } else if (thisSize < otherSize) {
653 private static class BuilderImpl implements InstanceIdentifierBuilder {
654 private final HashCodeBuilder<PathArgument> hash;
655 private final List<PathArgument> path;
657 public BuilderImpl() {
658 this.hash = new HashCodeBuilder<>();
659 this.path = new ArrayList<>();
662 public BuilderImpl(final Iterable<PathArgument> prefix, final int hash) {
663 this.path = Lists.newArrayList(prefix);
664 this.hash = new HashCodeBuilder<>(hash);
668 public InstanceIdentifierBuilder node(final QName nodeType) {
669 final PathArgument arg = new NodeIdentifier(nodeType);
671 hash.addArgument(arg);
676 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final QName key, final Object value) {
677 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, key, value);
679 hash.addArgument(arg);
684 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final Map<QName, Object> keyValues) {
685 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, keyValues);
687 hash.addArgument(arg);
693 public YangInstanceIdentifier toInstance() {
698 public YangInstanceIdentifier build() {
699 return new YangInstanceIdentifier(ImmutableList.copyOf(path), hash.toInstance());
704 public boolean contains(final YangInstanceIdentifier other) {
705 Preconditions.checkArgument(other != null, "other should not be null");
707 final Iterator<?> lit = pathArguments.iterator();
708 final Iterator<?> oit = other.pathArguments.iterator();
710 while (lit.hasNext()) {
711 if (!oit.hasNext()) {
715 if (!lit.next().equals(oit.next())) {
724 public String toString() {
726 * The toStringCache is safe, since the object contract requires
727 * immutability of the object and all objects referenced from this
729 * Used lists, maps are immutable. Path Arguments (elements) are also
730 * immutable, since the PathArgument contract requires immutability.
731 * The cache is thread-safe - if multiple computations occurs at the
732 * same time, cache will be overwritten with same result.
734 String ret = toStringCache;
736 synchronized (this) {
739 final StringBuilder builder = new StringBuilder('/');
740 boolean first = true;
741 for (PathArgument argument : getPathArguments()) {
747 builder.append(argument.toString());
750 ret = builder.toString();