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.ImmutableMap;
12 import com.google.common.collect.ImmutableSet;
13 import com.google.common.collect.Iterables;
14 import java.io.Serializable;
15 import java.lang.reflect.Array;
16 import java.util.Arrays;
17 import java.util.Collection;
18 import java.util.Iterator;
19 import java.util.List;
21 import java.util.Map.Entry;
22 import java.util.Objects;
24 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
25 import javax.annotation.Nonnull;
26 import javax.annotation.Nullable;
27 import org.opendaylight.yangtools.concepts.Builder;
28 import org.opendaylight.yangtools.concepts.Immutable;
29 import org.opendaylight.yangtools.concepts.Path;
30 import org.opendaylight.yangtools.util.HashCodeBuilder;
31 import org.opendaylight.yangtools.yang.common.QName;
32 import org.opendaylight.yangtools.yang.common.QNameModule;
33 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
36 * Unique identifier of a particular node instance in the data tree.
39 * Java representation of YANG Built-in type <code>instance-identifier</code>,
40 * which conceptually is XPath expression minimized to uniquely identify element
41 * in data tree which conforms to constraints maintained by YANG Model,
42 * effectively this makes Instance Identifier a path to element in data tree.
44 * Constraints put in YANG specification on instance-identifier allowed it to be
45 * effectively represented in Java and it's evaluation does not require
46 * full-blown XPath processor.
48 * <h3>Path Arguments</h3>
49 * Path to the node represented in instance identifier consists of
50 * {@link PathArgument} which carries necessary information to uniquely identify
51 * node on particular level in the subtree.
54 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
55 * <code>0..1</code> in particular subtree in data tree.</li>
56 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
57 * which has cardinality <code>0..n</code>.</li>
58 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
59 * <code>leaf-list</code> node.</li>
60 * <li>{@link AugmentationIdentifier} - Identifier of instance of
61 * <code>augmentation</code> node.</li>
65 * @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
67 public abstract class YangInstanceIdentifier extends IterablePathArguments implements Path<YangInstanceIdentifier>, Immutable, Serializable {
69 * An empty {@link YangInstanceIdentifier}. It corresponds to the path of the conceptual
70 * root of the YANG namespace.
72 public static final YangInstanceIdentifier EMPTY = FixedYangInstanceIdentifier.EMPTY_INSTANCE;
74 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
75 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
76 private static final long serialVersionUID = 4L;
78 private final int hash;
79 private transient volatile String toStringCache = null;
81 // Package-private to prevent outside subclassing
82 YangInstanceIdentifier(final int hash) {
86 @Nonnull abstract YangInstanceIdentifier createRelativeIdentifier(int skipFromRoot);
87 @Nonnull abstract Collection<PathArgument> tryPathArguments();
88 @Nonnull abstract Collection<PathArgument> tryReversePathArguments();
91 * Check if this instance identifier has empty path arguments, e.g. it is
92 * empty and corresponds to {@link #EMPTY}.
94 * @return True if this instance identifier is empty, false otherwise.
96 public abstract boolean isEmpty();
99 * Return the conceptual parent {@link YangInstanceIdentifier}, which has
100 * one item less in {@link #getPathArguments()}.
102 * @return Parent {@link YangInstanceIdentifier}, or null if this is object is {@link #EMPTY}.
104 @Nullable public abstract YangInstanceIdentifier getParent();
107 * Returns a list of path arguments.
109 * @deprecated Use {@link #getPathArguments()} instead.
110 * @return Immutable list of path arguments.
113 public abstract List<PathArgument> getPath();
116 * Returns an ordered iteration of path arguments.
118 * @return Immutable iteration of path arguments.
121 public abstract Collection<PathArgument> getPathArguments();
124 * Returns an iterable of path arguments in reverse order. This is useful
125 * when walking up a tree organized this way.
127 * @return Immutable iterable of path arguments in reverse order.
130 public abstract Collection<PathArgument> getReversePathArguments();
133 * Returns the last PathArgument. This is equivalent of iterating
134 * to the last element of the iterable returned by {@link #getPathArguments()}.
136 * @return The last past argument, or null if there are no PathArguments.
138 public abstract PathArgument getLastPathArgument();
140 public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
141 if (Iterables.isEmpty(path)) {
145 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
146 for (PathArgument a : path) {
150 return FixedYangInstanceIdentifier.create(path, hash.build());
153 public static YangInstanceIdentifier create(final PathArgument... path) {
154 // We are forcing a copy, since we cannot trust the user
155 return create(Arrays.asList(path));
159 public final int hashCode() {
161 * The caching is safe, since the object contract requires
162 * immutability of the object and all objects referenced from this
164 * Used lists, maps are immutable. Path Arguments (elements) are also
165 * immutable, since the PathArgument contract requires immutability.
170 boolean pathArgumentsEqual(final YangInstanceIdentifier other) {
171 return Iterables.elementsEqual(getPathArguments(), other.getPathArguments());
175 public boolean equals(final Object obj) {
179 if (!(obj instanceof YangInstanceIdentifier)) {
182 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
183 if (this.hashCode() != obj.hashCode()) {
187 return pathArgumentsEqual(other);
191 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
193 * @param name QName of {@link NodeIdentifier}
194 * @return Instance Identifier with additional path argument added to the end.
196 public final YangInstanceIdentifier node(final QName name) {
197 return node(new NodeIdentifier(name));
202 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
204 * @param arg Path argument which should be added to the end
205 * @return Instance Identifier with additional path argument added to the end.
207 public final YangInstanceIdentifier node(final PathArgument arg) {
208 return new StackedYangInstanceIdentifier(this, arg, HashCodeBuilder.nextHashCode(hash, arg));
212 * Get the relative path from an ancestor. This method attempts to perform
213 * the reverse of concatenating a base (ancestor) and a path.
216 * Ancestor against which the relative path should be calculated
217 * @return This object's relative path from parent, or Optional.absent() if
218 * the specified parent is not in fact an ancestor of this object.
220 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
221 final Iterator<?> lit = getPathArguments().iterator();
222 final Iterator<?> oit = ancestor.getPathArguments().iterator();
225 while (oit.hasNext()) {
226 // Ancestor is not really an ancestor
227 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
228 return Optional.absent();
235 return Optional.of(this);
237 if (!lit.hasNext()) {
238 return Optional.of(EMPTY);
241 return Optional.of(createRelativeIdentifier(common));
244 private static int hashCode(final Object value) {
249 if (value.getClass().equals(byte[].class)) {
250 return Arrays.hashCode((byte[]) value);
253 if (value.getClass().isArray()) {
255 int length = Array.getLength(value);
256 for (int i = 0; i < length; i++) {
257 hash += Objects.hashCode(Array.get(value, i));
263 return Objects.hashCode(value);
266 // Static factories & helpers
270 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
272 * @param name QName of first node identifier
273 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
275 public static YangInstanceIdentifier of(final QName name) {
276 return create(new NodeIdentifier(name));
281 * Returns new builder for InstanceIdentifier with empty path arguments.
283 * @return new builder for InstanceIdentifier with empty path arguments.
285 public static InstanceIdentifierBuilder builder() {
286 return new YangInstanceIdentifierBuilder();
291 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
293 * @param origin Instace Identifier from which path arguments are copied.
294 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
296 public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
297 return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
301 * Path argument / component of InstanceIdentifier
303 * Path argument uniquely identifies node in data tree on particular
306 * This interface itself is used as common parent for actual
307 * path arguments types and should not be implemented by user code.
309 * Path arguments SHOULD contain only minimum of information
310 * required to uniquely identify node on particular subtree level.
312 * For actual path arguments types see:
314 * <li>{@link NodeIdentifier} - Identifier of container or leaf
315 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
316 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
317 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
320 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
322 * If applicable returns unique QName of data node as defined in YANG
325 * This method may return null, if the corresponding schema node, does
326 * not have QName associated, such as in cases of augmentations.
333 * Return the string representation of this object for use in context
334 * provided by a previous object. This method can be implemented in
335 * terms of {@link #toString()}, but implementations are encourage to
336 * reuse any context already emitted by the previous object.
338 * @param previous Previous path argument
339 * @return String representation
341 String toRelativeString(PathArgument previous);
344 private static abstract class AbstractPathArgument implements PathArgument {
345 private static final long serialVersionUID = -4546547994250849340L;
346 private final QName nodeType;
347 private transient int hashValue;
348 private volatile transient boolean hashGuard = false;
350 protected AbstractPathArgument(final QName nodeType) {
351 this.nodeType = Preconditions.checkNotNull(nodeType);
355 public final QName getNodeType() {
360 public int compareTo(final PathArgument o) {
361 return nodeType.compareTo(o.getNodeType());
364 protected int hashCodeImpl() {
365 return 31 + getNodeType().hashCode();
369 public final int hashCode() {
371 hashValue = hashCodeImpl();
379 public boolean equals(final Object obj) {
383 if (obj == null || this.getClass() != obj.getClass()) {
387 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
391 public String toString() {
392 return getNodeType().toString();
396 public String toRelativeString(final PathArgument previous) {
397 if (previous instanceof AbstractPathArgument) {
398 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
399 if (getNodeType().getModule().equals(mod)) {
400 return getNodeType().getLocalName();
404 return getNodeType().toString();
409 * Fluent Builder of Instance Identifier instances
411 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
413 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
415 * @param nodeType QName of {@link NodeIdentifier} which will be added
416 * @return this builder
418 InstanceIdentifierBuilder node(QName nodeType);
421 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
423 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
424 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
425 * @return this builder
427 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
430 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
432 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
433 * @param key QName of key which will be added
434 * @param value value of key which will be added
435 * @return this builder
437 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
441 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
443 * @return {@link YangInstanceIdentifier}
446 YangInstanceIdentifier build();
449 * @deprecated use #build()
452 YangInstanceIdentifier toInstance();
456 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
457 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
459 public static final class NodeIdentifier extends AbstractPathArgument {
460 private static final long serialVersionUID = -2255888212390871347L;
462 public NodeIdentifier(final QName node) {
468 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
471 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
472 private static final long serialVersionUID = -4787195606494761540L;
474 private final Map<QName, Object> keyValues;
476 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
478 this.keyValues = ImmutableMap.copyOf(keyValues);
481 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
482 this(node, ImmutableMap.of(key, value));
485 public Map<QName, Object> getKeyValues() {
490 protected int hashCodeImpl() {
491 final int prime = 31;
492 int result = super.hashCodeImpl();
493 result = prime * result;
495 for (Entry<QName, Object> entry : keyValues.entrySet()) {
496 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
502 public boolean equals(final Object obj) {
503 if (!super.equals(obj)) {
507 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
508 if (keyValues.size() != otherKeyValues.size()) {
512 for (Entry<QName, Object> entry : keyValues.entrySet()) {
513 if (!otherKeyValues.containsKey(entry.getKey())
514 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
524 public String toString() {
525 return super.toString() + '[' + keyValues + ']';
529 public String toRelativeString(final PathArgument previous) {
530 return super.toRelativeString(previous) + '[' + keyValues + ']';
535 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
538 public static final class NodeWithValue extends AbstractPathArgument {
539 private static final long serialVersionUID = -3637456085341738431L;
541 private final Object value;
543 public NodeWithValue(final QName node, final Object value) {
548 public Object getValue() {
553 protected int hashCodeImpl() {
554 final int prime = 31;
555 int result = super.hashCodeImpl();
556 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
561 public boolean equals(final Object obj) {
562 if (!super.equals(obj)) {
565 final NodeWithValue other = (NodeWithValue) obj;
566 return Objects.deepEquals(value, other.value);
570 public String toString() {
571 return super.toString() + '[' + value + ']';
575 public String toRelativeString(final PathArgument previous) {
576 return super.toRelativeString(previous) + '[' + value + ']';
581 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
582 * particular subtree.
584 * Augmentation is uniquely identified by set of all possible child nodes.
586 * to identify instance of augmentation,
587 * since RFC6020 states that <code>augment</code> that augment
588 * statement must not add multiple nodes from same namespace
589 * / module to the target node.
592 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
594 public static final class AugmentationIdentifier implements PathArgument {
595 private static final long serialVersionUID = -8122335594681936939L;
596 private final ImmutableSet<QName> childNames;
599 public QName getNodeType() {
600 // This should rather throw exception than return always null
601 throw new UnsupportedOperationException("Augmentation node has no QName");
606 * Construct new augmentation identifier using supplied set of possible
610 * Set of possible child nodes.
612 public AugmentationIdentifier(final Set<QName> childNames) {
613 this.childNames = ImmutableSet.copyOf(childNames);
617 * Returns set of all possible child nodes
619 * @return set of all possible child nodes.
621 public Set<QName> getPossibleChildNames() {
626 public String toString() {
627 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
628 sb.append("childNames=").append(childNames).append('}');
629 return sb.toString();
633 public String toRelativeString(final PathArgument previous) {
638 public boolean equals(final Object o) {
642 if (!(o instanceof AugmentationIdentifier)) {
646 AugmentationIdentifier that = (AugmentationIdentifier) o;
647 return childNames.equals(that.childNames);
651 public int hashCode() {
652 return childNames.hashCode();
656 public int compareTo(final PathArgument o) {
657 if (!(o instanceof AugmentationIdentifier)) {
660 AugmentationIdentifier other = (AugmentationIdentifier) o;
661 Set<QName> otherChildNames = other.getPossibleChildNames();
662 int thisSize = childNames.size();
663 int otherSize = otherChildNames.size();
664 if (thisSize == otherSize) {
665 Iterator<QName> otherIterator = otherChildNames.iterator();
666 for (QName name : childNames) {
667 int c = name.compareTo(otherIterator.next());
673 } else if (thisSize < otherSize) {
682 public final boolean contains(final YangInstanceIdentifier other) {
683 Preconditions.checkArgument(other != null, "other should not be null");
685 final Iterator<?> lit = getPathArguments().iterator();
686 final Iterator<?> oit = other.getPathArguments().iterator();
688 while (lit.hasNext()) {
689 if (!oit.hasNext()) {
693 if (!lit.next().equals(oit.next())) {
702 public final String toString() {
704 * The toStringCache is safe, since the object contract requires
705 * immutability of the object and all objects referenced from this
707 * Used lists, maps are immutable. Path Arguments (elements) are also
708 * immutable, since the PathArgument contract requires immutability.
709 * The cache is thread-safe - if multiple computations occurs at the
710 * same time, cache will be overwritten with same result.
712 String ret = toStringCache;
714 final StringBuilder builder = new StringBuilder("/");
715 PathArgument prev = null;
716 for (PathArgument argument : getPathArguments()) {
720 builder.append(argument.toRelativeString(prev));
724 ret = builder.toString();
725 TOSTRINGCACHE_UPDATER.lazySet(this, ret);