2 * Copyright (c) 2014 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.data.api;
10 import com.google.common.annotations.Beta;
11 import com.google.common.base.Optional;
12 import com.google.common.base.Preconditions;
13 import com.google.common.collect.ImmutableMap;
14 import com.google.common.collect.ImmutableSet;
15 import com.google.common.collect.Iterables;
16 import java.io.Serializable;
17 import java.lang.reflect.Array;
18 import java.util.Arrays;
19 import java.util.Collection;
20 import java.util.Iterator;
21 import java.util.List;
23 import java.util.Map.Entry;
24 import java.util.Objects;
26 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
27 import javax.annotation.Nonnull;
28 import javax.annotation.Nullable;
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.common.QNameModule;
35 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
38 * Unique identifier of a particular node instance in the data tree.
41 * Java representation of YANG Built-in type <code>instance-identifier</code>,
42 * which conceptually is XPath expression minimized to uniquely identify element
43 * in data tree which conforms to constraints maintained by YANG Model,
44 * effectively this makes Instance Identifier a path to element in data tree.
46 * Constraints put in YANG specification on instance-identifier allowed it to be
47 * effectively represented in Java and it's evaluation does not require
48 * full-blown XPath processor.
50 * <h3>Path Arguments</h3>
51 * Path to the node represented in instance identifier consists of
52 * {@link PathArgument} which carries necessary information to uniquely identify
53 * node on particular level in the subtree.
56 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
57 * <code>0..1</code> in particular subtree in data tree.</li>
58 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
59 * which has cardinality <code>0..n</code>.</li>
60 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
61 * <code>leaf-list</code> node.</li>
62 * <li>{@link AugmentationIdentifier} - Identifier of instance of
63 * <code>augmentation</code> node.</li>
67 * @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
69 public abstract class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
71 * An empty {@link YangInstanceIdentifier}. It corresponds to the path of the conceptual
72 * root of the YANG namespace.
74 public static final YangInstanceIdentifier EMPTY = FixedYangInstanceIdentifier.EMPTY_INSTANCE;
76 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
77 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
78 private static final long serialVersionUID = 4L;
80 private final int hash;
81 private transient volatile String toStringCache = null;
83 // Package-private to prevent outside subclassing
84 YangInstanceIdentifier(final int hash) {
88 @Nonnull abstract YangInstanceIdentifier createRelativeIdentifier(int skipFromRoot);
89 @Nonnull abstract Collection<PathArgument> tryPathArguments();
90 @Nonnull abstract Collection<PathArgument> tryReversePathArguments();
93 * Check if this instance identifier has empty path arguments, e.g. it is
94 * empty and corresponds to {@link #EMPTY}.
96 * @return True if this instance identifier is empty, false otherwise.
98 public abstract boolean isEmpty();
101 * Return an optimized version of this identifier, useful when the identifier
102 * will be used very frequently.
104 * @return A optimized equivalent instance.
107 public abstract YangInstanceIdentifier toOptimized();
110 * Return the conceptual parent {@link YangInstanceIdentifier}, which has
111 * one item less in {@link #getPathArguments()}.
113 * @return Parent {@link YangInstanceIdentifier}, or null if this is object is {@link #EMPTY}.
115 @Nullable public abstract YangInstanceIdentifier getParent();
118 * Returns an ordered iteration of path arguments.
120 * @return Immutable iteration of path arguments.
122 public abstract List<PathArgument> getPathArguments();
125 * Returns an iterable of path arguments in reverse order. This is useful
126 * when walking up a tree organized this way.
128 * @return Immutable iterable of path arguments in reverse order.
130 public abstract List<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));
245 public final boolean contains(final YangInstanceIdentifier other) {
246 Preconditions.checkArgument(other != null, "other should not be null");
248 final Iterator<?> lit = getPathArguments().iterator();
249 final Iterator<?> oit = other.getPathArguments().iterator();
251 while (lit.hasNext()) {
252 if (!oit.hasNext()) {
256 if (!lit.next().equals(oit.next())) {
265 public final String toString() {
267 * The toStringCache is safe, since the object contract requires
268 * immutability of the object and all objects referenced from this
270 * Used lists, maps are immutable. Path Arguments (elements) are also
271 * immutable, since the PathArgument contract requires immutability.
272 * The cache is thread-safe - if multiple computations occurs at the
273 * same time, cache will be overwritten with same result.
275 String ret = toStringCache;
277 final StringBuilder builder = new StringBuilder("/");
278 PathArgument prev = null;
279 for (PathArgument argument : getPathArguments()) {
283 builder.append(argument.toRelativeString(prev));
287 ret = builder.toString();
288 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
293 private static int hashCode(final Object value) {
298 if (byte[].class.equals(value.getClass())) {
299 return Arrays.hashCode((byte[]) value);
302 if (value.getClass().isArray()) {
304 int length = Array.getLength(value);
305 for (int i = 0; i < length; i++) {
306 hash += Objects.hashCode(Array.get(value, i));
312 return Objects.hashCode(value);
315 // Static factories & helpers
318 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
320 * @param name QName of first node identifier
321 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
323 public static YangInstanceIdentifier of(final QName name) {
324 return create(new NodeIdentifier(name));
328 * Returns new builder for InstanceIdentifier with empty path arguments.
330 * @return new builder for InstanceIdentifier with empty path arguments.
332 public static InstanceIdentifierBuilder builder() {
333 return new YangInstanceIdentifierBuilder();
338 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
340 * @param origin InstanceIdentifier from which path arguments are copied.
341 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
343 public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
344 return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
348 * Path argument / component of InstanceIdentifier
350 * Path argument uniquely identifies node in data tree on particular
353 * This interface itself is used as common parent for actual
354 * path arguments types and should not be implemented by user code.
356 * Path arguments SHOULD contain only minimum of information
357 * required to uniquely identify node on particular subtree level.
359 * For actual path arguments types see:
361 * <li>{@link NodeIdentifier} - Identifier of container or leaf
362 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
363 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
364 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
367 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
369 * If applicable returns unique QName of data node as defined in YANG
372 * This method may return null, if the corresponding schema node, does
373 * not have QName associated, such as in cases of augmentations.
380 * Return the string representation of this object for use in context
381 * provided by a previous object. This method can be implemented in
382 * terms of {@link #toString()}, but implementations are encourage to
383 * reuse any context already emitted by the previous object.
385 * @param previous Previous path argument
386 * @return String representation
388 String toRelativeString(PathArgument previous);
391 private static abstract class AbstractPathArgument implements PathArgument {
392 private static final long serialVersionUID = -4546547994250849340L;
393 private final QName nodeType;
394 private transient int hashValue;
395 private volatile transient boolean hashGuard = false;
397 protected AbstractPathArgument(final QName nodeType) {
398 this.nodeType = Preconditions.checkNotNull(nodeType);
402 public final QName getNodeType() {
407 public int compareTo(final PathArgument o) {
408 return nodeType.compareTo(o.getNodeType());
411 protected int hashCodeImpl() {
412 return 31 + getNodeType().hashCode();
416 public final int hashCode() {
418 hashValue = hashCodeImpl();
426 public boolean equals(final Object obj) {
430 if (obj == null || this.getClass() != obj.getClass()) {
434 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
438 public String toString() {
439 return getNodeType().toString();
443 public String toRelativeString(final PathArgument previous) {
444 if (previous instanceof AbstractPathArgument) {
445 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
446 if (getNodeType().getModule().equals(mod)) {
447 return getNodeType().getLocalName();
451 return getNodeType().toString();
456 * Fluent Builder of Instance Identifier instances
458 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
460 * Adds a {@link PathArgument} to to path arguments of resulting instance identifier.
462 * @param arg A {@link PathArgument} to be added
463 * @return this builder
465 InstanceIdentifierBuilder node(PathArgument arg);
468 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
470 * @param nodeType QName of {@link NodeIdentifier} which will be added
471 * @return this builder
473 InstanceIdentifierBuilder node(QName nodeType);
476 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
478 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
479 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
480 * @return this builder
482 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
485 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
487 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
488 * @param key QName of key which will be added
489 * @param value value of key which will be added
490 * @return this builder
492 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
496 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
498 * @return {@link YangInstanceIdentifier}
501 YangInstanceIdentifier build();
504 * @deprecated use #build()
507 YangInstanceIdentifier toInstance();
511 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
512 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
514 public static final class NodeIdentifier extends AbstractPathArgument {
515 private static final long serialVersionUID = -2255888212390871347L;
517 public NodeIdentifier(final QName node) {
523 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
526 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
527 private static final long serialVersionUID = -4787195606494761540L;
529 private final Map<QName, Object> keyValues;
531 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
533 this.keyValues = ImmutableMap.copyOf(keyValues);
536 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
537 this(node, ImmutableMap.of(key, value));
540 public Map<QName, Object> getKeyValues() {
545 protected int hashCodeImpl() {
546 final int prime = 31;
547 int result = super.hashCodeImpl();
548 result = prime * result;
550 for (Entry<QName, Object> entry : keyValues.entrySet()) {
551 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
557 public boolean equals(final Object obj) {
558 if (!super.equals(obj)) {
562 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
564 // TODO: benchmark to see if just calling equals() on the two maps is not faster
565 if (keyValues == otherKeyValues) {
568 if (keyValues.size() != otherKeyValues.size()) {
572 for (Entry<QName, Object> entry : keyValues.entrySet()) {
573 if (!otherKeyValues.containsKey(entry.getKey())
574 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
584 public String toString() {
585 return super.toString() + '[' + keyValues + ']';
589 public String toRelativeString(final PathArgument previous) {
590 return super.toRelativeString(previous) + '[' + keyValues + ']';
595 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
598 public static final class NodeWithValue extends AbstractPathArgument {
599 private static final long serialVersionUID = -3637456085341738431L;
601 private final Object value;
603 public NodeWithValue(final QName node, final Object value) {
608 public Object getValue() {
613 protected int hashCodeImpl() {
614 final int prime = 31;
615 int result = super.hashCodeImpl();
616 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
621 public boolean equals(final Object obj) {
622 if (!super.equals(obj)) {
625 final NodeWithValue other = (NodeWithValue) obj;
626 return Objects.deepEquals(value, other.value);
630 public String toString() {
631 return super.toString() + '[' + value + ']';
635 public String toRelativeString(final PathArgument previous) {
636 return super.toRelativeString(previous) + '[' + value + ']';
641 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
642 * particular subtree.
644 * Augmentation is uniquely identified by set of all possible child nodes.
646 * to identify instance of augmentation,
647 * since RFC6020 states that <code>augment</code> that augment
648 * statement must not add multiple nodes from same namespace
649 * / module to the target node.
652 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
654 public static final class AugmentationIdentifier implements PathArgument {
655 private static final long serialVersionUID = -8122335594681936939L;
656 private final ImmutableSet<QName> childNames;
659 public QName getNodeType() {
660 // This should rather throw exception than return always null
661 throw new UnsupportedOperationException("Augmentation node has no QName");
666 * Construct new augmentation identifier using supplied set of possible
670 * Set of possible child nodes.
672 public AugmentationIdentifier(final Set<QName> childNames) {
673 this.childNames = ImmutableSet.copyOf(childNames);
677 * Returns set of all possible child nodes
679 * @return set of all possible child nodes.
681 public Set<QName> getPossibleChildNames() {
686 public String toString() {
687 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
688 sb.append("childNames=").append(childNames).append('}');
689 return sb.toString();
693 public String toRelativeString(final PathArgument previous) {
698 public boolean equals(final Object o) {
702 if (!(o instanceof AugmentationIdentifier)) {
706 AugmentationIdentifier that = (AugmentationIdentifier) o;
707 return childNames.equals(that.childNames);
711 public int hashCode() {
712 return childNames.hashCode();
716 public int compareTo(final PathArgument o) {
717 if (!(o instanceof AugmentationIdentifier)) {
720 AugmentationIdentifier other = (AugmentationIdentifier) o;
721 Set<QName> otherChildNames = other.getPossibleChildNames();
722 int thisSize = childNames.size();
723 int otherSize = otherChildNames.size();
724 if (thisSize == otherSize) {
725 Iterator<QName> otherIterator = otherChildNames.iterator();
726 for (QName name : childNames) {
727 int c = name.compareTo(otherIterator.next());
733 } else if (thisSize < otherSize) {