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;
16 import java.io.IOException;
17 import java.io.ObjectInputStream;
18 import java.io.ObjectOutputStream;
19 import java.io.ObjectStreamException;
20 import java.io.Serializable;
21 import java.lang.reflect.Array;
22 import java.lang.reflect.Field;
23 import java.util.ArrayList;
24 import java.util.Arrays;
25 import java.util.Collections;
26 import java.util.Iterator;
27 import java.util.List;
29 import java.util.Map.Entry;
30 import java.util.Objects;
32 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
33 import org.opendaylight.yangtools.concepts.Builder;
34 import org.opendaylight.yangtools.concepts.Immutable;
35 import org.opendaylight.yangtools.concepts.Path;
36 import org.opendaylight.yangtools.util.HashCodeBuilder;
37 import org.opendaylight.yangtools.yang.common.QName;
38 import org.opendaylight.yangtools.yang.common.QNameModule;
39 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
42 * Unique identifier of a particular node instance in the data tree.
45 * Java representation of YANG Built-in type <code>instance-identifier</code>,
46 * which conceptually is XPath expression minimized to uniquely identify element
47 * in data tree which conforms to constraints maintained by YANG Model,
48 * effectively this makes Instance Identifier a path to element in data tree.
50 * Constraints put in YANG specification on instance-identifier allowed it to be
51 * effectively represented in Java and it's evaluation does not require
52 * full-blown XPath processor.
54 * <h3>Path Arguments</h3>
55 * Path to the node represented in instance identifier consists of
56 * {@link PathArgument} which carries necessary information to uniquely identify
57 * node on particular level in the subtree.
60 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
61 * <code>0..1</code> in particular subtree in data tree.</li>
62 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
63 * which has cardinality <code>0..n</code>.</li>
64 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
65 * <code>leaf-list</code> node.</li>
66 * <li>{@link AugmentationIdentifier} - Identifier of instance of
67 * <code>augmentation</code> node.</li>
71 * @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
73 public final class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
75 * An empty {@link YangInstanceIdentifier}. It corresponds to the path of the conceptual
76 * root of the YANG namespace.
78 public static final YangInstanceIdentifier EMPTY = trustedCreate(Collections.<PathArgument>emptyList());
79 @SuppressWarnings("rawtypes")
80 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, ImmutableList> LEGACYPATH_UPDATER =
81 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, ImmutableList.class, "legacyPath");
82 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
83 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
84 private static final Field PATHARGUMENTS_FIELD;
86 private static final long serialVersionUID = 3L;
87 private final transient Iterable<PathArgument> pathArguments;
88 private final int hash;
90 private volatile ImmutableList<PathArgument> legacyPath = null;
91 private transient volatile String toStringCache = null;
96 f = YangInstanceIdentifier.class.getDeclaredField("pathArguments");
97 } catch (NoSuchFieldException | SecurityException e) {
98 throw new ExceptionInInitializerError(e);
100 f.setAccessible(true);
102 PATHARGUMENTS_FIELD = f;
105 private ImmutableList<PathArgument> getLegacyPath() {
106 // Temporary variable saves a volatile read
107 ImmutableList<PathArgument> ret = legacyPath;
109 // We could have used a synchronized block, but the window is quite
110 // small and worst that can happen is duplicate object construction.
111 ret = ImmutableList.copyOf(pathArguments);
112 LEGACYPATH_UPDATER.lazySet(this, ret);
119 * Returns a list of path arguments.
121 * @deprecated Use {@link #getPathArguments()} instead.
122 * @return Immutable list of path arguments.
125 public List<PathArgument> getPath() {
126 return getLegacyPath();
130 * Returns an ordered iteration of path arguments.
132 * @return Immutable iteration of path arguments.
134 public Iterable<PathArgument> getPathArguments() {
135 return pathArguments;
139 * Returns an iterable of path arguments in reverse order. This is useful
140 * when walking up a tree organized this way.
142 * @return Immutable iterable of path arguments in reverse order.
144 public Iterable<PathArgument> getReversePathArguments() {
145 return getLegacyPath().reverse();
149 * Returns the last PathArgument. This is equivalent of iterating
150 * to the last element of the iterable returned by {@link #getPathArguments()}.
152 * @return The last past argument, or null if there are no PathArguments.
154 public PathArgument getLastPathArgument() {
155 return Iterables.getFirst(getReversePathArguments(), null);
158 private YangInstanceIdentifier(final Iterable<PathArgument> path, final int hash) {
159 this.pathArguments = Preconditions.checkNotNull(path, "path must not be null.");
163 private static YangInstanceIdentifier trustedCreate(final Iterable<PathArgument> path) {
164 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
165 for (PathArgument a : path) {
169 return new YangInstanceIdentifier(path, hash.build());
172 public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
173 if (Iterables.isEmpty(path)) {
177 return trustedCreate(ImmutableList.copyOf(path));
180 public static YangInstanceIdentifier create(final PathArgument... path) {
181 // We are forcing a copy, since we cannot trust the user
182 return create(Arrays.asList(path));
186 public int hashCode() {
188 * The caching is safe, since the object contract requires
189 * immutability of the object and all objects referenced from this
191 * Used lists, maps are immutable. Path Arguments (elements) are also
192 * immutable, since the PathArgument contract requires immutability.
198 public boolean equals(final Object obj) {
205 if (getClass() != obj.getClass()) {
208 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
209 if (this.hashCode() != obj.hashCode()) {
212 return Iterables.elementsEqual(pathArguments, other.pathArguments);
216 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
218 * @param name QName of {@link NodeIdentifier}
219 * @return Instance Identifier with additional path argument added to the end.
221 public YangInstanceIdentifier node(final QName name) {
222 return node(new NodeIdentifier(name));
227 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
229 * @param arg Path argument which should be added to the end
230 * @return Instance Identifier with additional path argument added to the end.
232 public YangInstanceIdentifier node(final PathArgument arg) {
233 return new YangInstanceIdentifier(Iterables.concat(pathArguments, Collections.singleton(arg)), HashCodeBuilder.nextHashCode(hash, arg));
237 * Get the relative path from an ancestor. This method attempts to perform
238 * the reverse of concatenating a base (ancestor) and a path.
241 * Ancestor against which the relative path should be calculated
242 * @return This object's relative path from parent, or Optional.absent() if
243 * the specified parent is not in fact an ancestor of this object.
245 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
246 final Iterator<?> lit = pathArguments.iterator();
247 final Iterator<?> oit = ancestor.pathArguments.iterator();
250 while (oit.hasNext()) {
251 // Ancestor is not really an ancestor
252 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
253 return Optional.absent();
260 return Optional.of(this);
262 if (!lit.hasNext()) {
263 return Optional.of(EMPTY);
265 return Optional.of(trustedCreate(Iterables.skip(pathArguments, common)));
268 private static int hashCode(final Object value) {
273 if (value.getClass().equals(byte[].class)) {
274 return Arrays.hashCode((byte[]) value);
277 if (value.getClass().isArray()) {
279 int length = Array.getLength(value);
280 for (int i = 0; i < length; i++) {
281 hash += Objects.hashCode(Array.get(value, i));
287 return Objects.hashCode(value);
290 // Static factories & helpers
294 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
296 * @param name QName of first node identifier
297 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
299 public static YangInstanceIdentifier of(final QName name) {
300 return create(new NodeIdentifier(name));
305 * Returns new builder for InstanceIdentifier with empty path arguments.
307 * @return new builder for InstanceIdentifier with empty path arguments.
309 public static InstanceIdentifierBuilder builder() {
310 return new BuilderImpl();
315 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
317 * @param origin Instace Identifier from which path arguments are copied.
318 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
320 public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
321 return new BuilderImpl(origin.getPathArguments(), origin.hashCode());
325 * Path argument / component of InstanceIdentifier
327 * Path argument uniquely identifies node in data tree on particular
330 * This interface itself is used as common parent for actual
331 * path arguments types and should not be implemented by user code.
333 * Path arguments SHOULD contain only minimum of information
334 * required to uniquely identify node on particular subtree level.
336 * For actual path arguments types see:
338 * <li>{@link NodeIdentifier} - Identifier of container or leaf
339 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
340 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
341 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
344 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
346 * If applicable returns unique QName of data node as defined in YANG
349 * This method may return null, if the corresponding schema node, does
350 * not have QName associated, such as in cases of augmentations.
357 * Return the string representation of this object for use in context
358 * provided by a previous object. This method can be implemented in
359 * terms of {@link #toString()}, but implementations are encourage to
360 * reuse any context already emitted by the previous object.
362 * @param previous Previous path argument
363 * @return String representation
365 String toRelativeString(PathArgument previous);
368 private static abstract class AbstractPathArgument implements PathArgument {
369 private static final AtomicReferenceFieldUpdater<AbstractPathArgument, Integer> HASH_UPDATER =
370 AtomicReferenceFieldUpdater.newUpdater(AbstractPathArgument.class, Integer.class, "hash");
371 private static final long serialVersionUID = -4546547994250849340L;
372 private final QName nodeType;
373 private volatile transient Integer hash = null;
375 protected AbstractPathArgument(final QName nodeType) {
376 this.nodeType = Preconditions.checkNotNull(nodeType);
380 public final QName getNodeType() {
385 public int compareTo(final PathArgument o) {
386 return nodeType.compareTo(o.getNodeType());
389 protected int hashCodeImpl() {
390 return 31 + getNodeType().hashCode();
394 public final int hashCode() {
397 ret = hashCodeImpl();
398 HASH_UPDATER.lazySet(this, ret);
405 public boolean equals(final Object obj) {
409 if (obj == null || this.getClass() != obj.getClass()) {
413 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
417 public String toString() {
418 return getNodeType().toString();
422 public String toRelativeString(final PathArgument previous) {
423 if (previous instanceof AbstractPathArgument) {
424 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
425 if (getNodeType().getModule().equals(mod)) {
426 return getNodeType().getLocalName();
430 return getNodeType().toString();
435 * Fluent Builder of Instance Identifier instances
437 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
439 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
441 * @param nodeType QName of {@link NodeIdentifier} which will be added
442 * @return this builder
444 InstanceIdentifierBuilder node(QName nodeType);
447 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
449 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
450 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
451 * @return this builder
453 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
456 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
458 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
459 * @param key QName of key which will be added
460 * @param value value of key which will be added
461 * @return this builder
463 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
467 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
469 * @return {@link YangInstanceIdentifier}
472 YangInstanceIdentifier build();
475 * @deprecated use #build()
478 YangInstanceIdentifier toInstance();
482 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
483 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
485 public static final class NodeIdentifier extends AbstractPathArgument {
486 private static final long serialVersionUID = -2255888212390871347L;
488 public NodeIdentifier(final QName node) {
494 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
497 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
498 private static final long serialVersionUID = -4787195606494761540L;
500 private final Map<QName, Object> keyValues;
502 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
504 this.keyValues = ImmutableMap.copyOf(keyValues);
507 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
508 this(node, ImmutableMap.of(key, value));
511 public Map<QName, Object> getKeyValues() {
516 protected int hashCodeImpl() {
517 final int prime = 31;
518 int result = super.hashCodeImpl();
519 result = prime * result;
521 for (Entry<QName, Object> entry : keyValues.entrySet()) {
522 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
528 public boolean equals(final Object obj) {
529 if (!super.equals(obj)) {
533 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
534 if (keyValues.size() != otherKeyValues.size()) {
538 for (Entry<QName, Object> entry : keyValues.entrySet()) {
539 if (!otherKeyValues.containsKey(entry.getKey())
540 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
550 public String toString() {
551 return super.toString() + '[' + keyValues + ']';
555 public String toRelativeString(final PathArgument previous) {
556 return super.toRelativeString(previous) + '[' + keyValues + ']';
561 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
564 public static final class NodeWithValue extends AbstractPathArgument {
565 private static final long serialVersionUID = -3637456085341738431L;
567 private final Object value;
569 public NodeWithValue(final QName node, final Object value) {
574 public Object getValue() {
579 protected int hashCodeImpl() {
580 final int prime = 31;
581 int result = super.hashCodeImpl();
582 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
587 public boolean equals(final Object obj) {
588 if (!super.equals(obj)) {
591 final NodeWithValue other = (NodeWithValue) obj;
592 return Objects.deepEquals(value, other.value);
596 public String toString() {
597 return super.toString() + '[' + value + ']';
601 public String toRelativeString(final PathArgument previous) {
602 return super.toRelativeString(previous) + '[' + value + ']';
607 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
608 * particular subtree.
610 * Augmentation is uniquely identified by set of all possible child nodes.
612 * to identify instance of augmentation,
613 * since RFC6020 states that <code>augment</code> that augment
614 * statement must not add multiple nodes from same namespace
615 * / module to the target node.
618 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
620 public static final class AugmentationIdentifier implements PathArgument {
621 private static final long serialVersionUID = -8122335594681936939L;
622 private final ImmutableSet<QName> childNames;
625 public QName getNodeType() {
626 // This should rather throw exception than return always null
627 throw new UnsupportedOperationException("Augmentation node has no QName");
632 * Construct new augmentation identifier using supplied set of possible
636 * Set of possible child nodes.
638 public AugmentationIdentifier(final Set<QName> childNames) {
639 this.childNames = ImmutableSet.copyOf(childNames);
643 * Returns set of all possible child nodes
645 * @return set of all possible child nodes.
647 public Set<QName> getPossibleChildNames() {
652 public String toString() {
653 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
654 sb.append("childNames=").append(childNames).append('}');
655 return sb.toString();
659 public String toRelativeString(final PathArgument previous) {
664 public boolean equals(final Object o) {
668 if (!(o instanceof AugmentationIdentifier)) {
672 AugmentationIdentifier that = (AugmentationIdentifier) o;
673 return childNames.equals(that.childNames);
677 public int hashCode() {
678 return childNames.hashCode();
682 public int compareTo(final PathArgument o) {
683 if (!(o instanceof AugmentationIdentifier)) {
686 AugmentationIdentifier other = (AugmentationIdentifier) o;
687 Set<QName> otherChildNames = other.getPossibleChildNames();
688 int thisSize = childNames.size();
689 int otherSize = otherChildNames.size();
690 if (thisSize == otherSize) {
691 Iterator<QName> otherIterator = otherChildNames.iterator();
692 for (QName name : childNames) {
693 int c = name.compareTo(otherIterator.next());
699 } else if (thisSize < otherSize) {
707 private static class BuilderImpl implements InstanceIdentifierBuilder {
708 private final HashCodeBuilder<PathArgument> hash;
709 private final List<PathArgument> path;
711 public BuilderImpl() {
712 this.hash = new HashCodeBuilder<>();
713 this.path = new ArrayList<>();
716 public BuilderImpl(final Iterable<PathArgument> prefix, final int hash) {
717 this.path = Lists.newArrayList(prefix);
718 this.hash = new HashCodeBuilder<>(hash);
722 public InstanceIdentifierBuilder node(final QName nodeType) {
723 final PathArgument arg = new NodeIdentifier(nodeType);
725 hash.addArgument(arg);
730 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final QName key, final Object value) {
731 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, key, value);
733 hash.addArgument(arg);
738 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final Map<QName, Object> keyValues) {
739 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, keyValues);
741 hash.addArgument(arg);
747 public YangInstanceIdentifier toInstance() {
752 public YangInstanceIdentifier build() {
753 return new YangInstanceIdentifier(ImmutableList.copyOf(path), hash.build());
758 public boolean contains(final YangInstanceIdentifier other) {
759 Preconditions.checkArgument(other != null, "other should not be null");
761 final Iterator<?> lit = pathArguments.iterator();
762 final Iterator<?> oit = other.pathArguments.iterator();
764 while (lit.hasNext()) {
765 if (!oit.hasNext()) {
769 if (!lit.next().equals(oit.next())) {
778 public String toString() {
780 * The toStringCache is safe, since the object contract requires
781 * immutability of the object and all objects referenced from this
783 * Used lists, maps are immutable. Path Arguments (elements) are also
784 * immutable, since the PathArgument contract requires immutability.
785 * The cache is thread-safe - if multiple computations occurs at the
786 * same time, cache will be overwritten with same result.
788 String ret = toStringCache;
790 final StringBuilder builder = new StringBuilder("/");
791 PathArgument prev = null;
792 for (PathArgument argument : getPathArguments()) {
796 builder.append(argument.toRelativeString(prev));
800 ret = builder.toString();
801 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
806 private void readObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
807 inputStream.defaultReadObject();
810 PATHARGUMENTS_FIELD.set(this, legacyPath);
811 } catch (IllegalArgumentException | IllegalAccessException e) {
812 throw new IOException(e);
816 private Object readResolve() throws ObjectStreamException {
817 return legacyPath.isEmpty() ? EMPTY : this;
820 private void writeObject(final ObjectOutputStream outputStream) throws IOException {
822 * This may look strange, but what we are doing here is side-stepping the fact
823 * that pathArguments is not generally serializable. We are forcing instantiation
824 * of the legacy path, which is an ImmutableList (thus Serializable) and write
825 * it out. The read path does the opposite -- it reads the legacyPath and then
826 * uses invocation API to set the field.
829 outputStream.defaultWriteObject();