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.Serializable;
20 import java.lang.reflect.Array;
21 import java.lang.reflect.Field;
22 import java.util.ArrayList;
23 import java.util.Arrays;
24 import java.util.Collections;
25 import java.util.Iterator;
26 import java.util.List;
28 import java.util.Map.Entry;
29 import java.util.Objects;
31 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
32 import org.opendaylight.yangtools.concepts.Builder;
33 import org.opendaylight.yangtools.concepts.Immutable;
34 import org.opendaylight.yangtools.concepts.Path;
35 import org.opendaylight.yangtools.util.HashCodeBuilder;
36 import org.opendaylight.yangtools.yang.common.QName;
37 import org.opendaylight.yangtools.yang.common.QNameModule;
38 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
41 * Unique identifier of a particular node instance in the data tree.
44 * Java representation of YANG Built-in type <code>instance-identifier</code>,
45 * which conceptually is XPath expression minimized to uniquely identify element
46 * in data tree which conforms to constraints maintained by YANG Model,
47 * effectively this makes Instance Identifier a path to element in data tree.
49 * Constraints put in YANG specification on instance-identifier allowed it to be
50 * effectively represented in Java and it's evaluation does not require
51 * full-blown XPath processor.
53 * <h3>Path Arguments</h3>
54 * Path to the node represented in instance identifier consists of
55 * {@link PathArgument} which carries necessary information to uniquely identify
56 * node on particular level in the subtree.
59 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
60 * <code>0..1</code> in particular subtree in data tree.</li>
61 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
62 * which has cardinality <code>0..n</code>.</li>
63 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
64 * <code>leaf-list</code> node.</li>
65 * <li>{@link AugmentationIdentifier} - Identifier of instance of
66 * <code>augmentation</code> node.</li>
70 * @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
72 public final class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
73 @SuppressWarnings("rawtypes")
74 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, ImmutableList> LEGACYPATH_UPDATER =
75 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, ImmutableList.class, "legacyPath");
76 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
77 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
78 private static final YangInstanceIdentifier EMPTY = trustedCreate(Collections.<PathArgument>emptyList());
79 private static final Field PATHARGUMENTS_FIELD;
81 private static final long serialVersionUID = 3L;
82 private transient final Iterable<PathArgument> pathArguments;
83 private final int hash;
85 private volatile ImmutableList<PathArgument> legacyPath = null;
86 private transient volatile String toStringCache = null;
91 f = YangInstanceIdentifier.class.getDeclaredField("pathArguments");
92 } catch (NoSuchFieldException | SecurityException e) {
93 throw new ExceptionInInitializerError(e);
95 f.setAccessible(true);
97 PATHARGUMENTS_FIELD = f;
100 private final ImmutableList<PathArgument> getLegacyPath() {
101 // Temporary variable saves a volatile read
102 ImmutableList<PathArgument> ret = legacyPath;
104 // We could have used a synchronized block, but the window is quite
105 // small and worst that can happen is duplicate object construction.
106 ret = ImmutableList.copyOf(pathArguments);
107 LEGACYPATH_UPDATER.lazySet(this, ret);
114 * Returns a list of path arguments.
116 * @deprecated Use {@link #getPathArguments()} instead.
117 * @return Immutable list of path arguments.
120 public List<PathArgument> getPath() {
121 return getLegacyPath();
125 * Returns an ordered iteration of path arguments.
127 * @return Immutable iteration of path arguments.
129 public Iterable<PathArgument> getPathArguments() {
130 return pathArguments;
134 * Returns an iterable of path arguments in reverse order. This is useful
135 * when walking up a tree organized this way.
137 * @return Immutable iterable of path arguments in reverse order.
139 public Iterable<PathArgument> getReversePathArguments() {
140 return getLegacyPath().reverse();
144 * Returns the last PathArgument. This is equivalent of iterating
145 * to the last element of the iterable returned by {@link #getPathArguments()}.
147 * @return The last past argument, or null if there are no PathArguments.
149 public PathArgument getLastPathArgument() {
150 return Iterables.getFirst(getReversePathArguments(), null);
153 private YangInstanceIdentifier(final Iterable<PathArgument> path, final int hash) {
154 this.pathArguments = Preconditions.checkNotNull(path, "path must not be null.");
158 private static final YangInstanceIdentifier trustedCreate(final Iterable<PathArgument> path) {
159 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
160 for (PathArgument a : path) {
164 return new YangInstanceIdentifier(path, hash.toInstance());
167 public static final YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
168 if (Iterables.isEmpty(path)) {
172 return trustedCreate(ImmutableList.copyOf(path));
175 public static final YangInstanceIdentifier create(final PathArgument... path) {
176 // We are forcing a copy, since we cannot trust the user
177 return create(Arrays.asList(path));
181 public int hashCode() {
183 * The caching is safe, since the object contract requires
184 * immutability of the object and all objects referenced from this
186 * Used lists, maps are immutable. Path Arguments (elements) are also
187 * immutable, since the PathArgument contract requires immutability.
193 public boolean equals(final Object obj) {
200 if (getClass() != obj.getClass()) {
203 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
204 if (this.hashCode() != obj.hashCode()) {
207 return Iterables.elementsEqual(pathArguments, other.pathArguments);
211 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
213 * @param name QName of {@link NodeIdentifier}
214 * @return Instance Identifier with additional path argument added to the end.
216 public YangInstanceIdentifier node(final QName name) {
217 return node(new NodeIdentifier(name));
222 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
224 * @param arg Path argument which should be added to the end
225 * @return Instance Identifier with additional path argument added to the end.
227 public YangInstanceIdentifier node(final PathArgument arg) {
228 return new YangInstanceIdentifier(Iterables.concat(pathArguments, Collections.singleton(arg)), HashCodeBuilder.nextHashCode(hash, arg));
232 * Get the relative path from an ancestor. This method attempts to perform
233 * the reverse of concatenating a base (ancestor) and a path.
236 * Ancestor against which the relative path should be calculated
237 * @return This object's relative path from parent, or Optional.absent() if
238 * the specified parent is not in fact an ancestor of this object.
240 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
241 final Iterator<?> lit = pathArguments.iterator();
242 final Iterator<?> oit = ancestor.pathArguments.iterator();
245 while (oit.hasNext()) {
246 // Ancestor is not really an ancestor
247 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
248 return Optional.absent();
255 return Optional.of(this);
257 if (!lit.hasNext()) {
258 return Optional.of(EMPTY);
260 return Optional.of(trustedCreate(Iterables.skip(pathArguments, common)));
263 private static int hashCode(final Object value) {
268 if (value.getClass().equals(byte[].class)) {
269 return Arrays.hashCode((byte[]) value);
272 if (value.getClass().isArray()) {
274 int length = Array.getLength(value);
275 for (int i = 0; i < length; i++) {
276 hash += Objects.hashCode(Array.get(value, i));
282 return Objects.hashCode(value);
285 // Static factories & helpers
289 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
291 * @param name QName of first node identifier
292 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
294 public static YangInstanceIdentifier of(final QName name) {
295 return create(new NodeIdentifier(name));
300 * Returns new builder for InstanceIdentifier with empty path arguments.
302 * @return new builder for InstanceIdentifier with empty path arguments.
304 static public InstanceIdentifierBuilder builder() {
305 return new BuilderImpl();
310 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
312 * @param origin Instace Identifier from which path arguments are copied.
313 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
315 static public InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
316 return new BuilderImpl(origin.getPathArguments(), origin.hashCode());
320 * Path argument / component of InstanceIdentifier
322 * Path argument uniquely identifies node in data tree on particular
325 * This interface itself is used as common parent for actual
326 * path arguments types and should not be implemented by user code.
328 * Path arguments SHOULD contain only minimum of information
329 * required to uniquely identify node on particular subtree level.
331 * For actual path arguments types see:
333 * <li>{@link NodeIdentifier} - Identifier of container or leaf
334 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
335 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
336 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
339 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
341 * If applicable returns unique QName of data node as defined in YANG
344 * This method may return null, if the corresponding schema node, does
345 * not have QName associated, such as in cases of augmentations.
352 * Return the string representation of this object for use in context
353 * provided by a previous object. This method can be implemented in
354 * terms of {@link #toString()}, but implementations are encourage to
355 * reuse any context already emitted by the previous object.
357 * @param previous Previous path argument
358 * @return String representation
360 String toRelativeString(PathArgument previous);
363 private static abstract class AbstractPathArgument implements PathArgument {
364 private static final AtomicReferenceFieldUpdater<AbstractPathArgument, Integer> HASH_UPDATER =
365 AtomicReferenceFieldUpdater.newUpdater(AbstractPathArgument.class, Integer.class, "hash");
366 private static final long serialVersionUID = -4546547994250849340L;
367 private final QName nodeType;
368 private volatile transient Integer hash = null;
370 protected AbstractPathArgument(final QName nodeType) {
371 this.nodeType = Preconditions.checkNotNull(nodeType);
375 public final QName getNodeType() {
380 public int compareTo(final PathArgument o) {
381 return nodeType.compareTo(o.getNodeType());
384 protected int hashCodeImpl() {
385 return 31 + getNodeType().hashCode();
389 public final int hashCode() {
392 ret = hashCodeImpl();
393 HASH_UPDATER.lazySet(this, ret);
400 public boolean equals(final Object obj) {
404 if (obj == null || this.getClass() != obj.getClass()) {
408 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
412 public String toString() {
413 return getNodeType().toString();
417 public String toRelativeString(final PathArgument previous) {
418 if (previous instanceof AbstractPathArgument) {
419 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
420 if (getNodeType().getModule().equals(mod)) {
421 return getNodeType().getLocalName();
425 return getNodeType().toString();
431 * Fluent Builder of Instance Identifier instances
436 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
438 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
440 * @param nodeType QName of {@link NodeIdentifier} which will be added
441 * @return this builder
443 InstanceIdentifierBuilder node(QName nodeType);
446 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
448 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
449 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
450 * @return this builder
452 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
455 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
457 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
458 * @param key QName of key which will be added
459 * @param value value of key which will be added
460 * @return this builder
462 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
466 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
468 * @return {@link YangInstanceIdentifier}
470 YangInstanceIdentifier build();
474 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
475 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
477 public static final class NodeIdentifier extends AbstractPathArgument {
478 private static final long serialVersionUID = -2255888212390871347L;
480 public NodeIdentifier(final QName node) {
486 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
489 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
490 private static final long serialVersionUID = -4787195606494761540L;
492 private final Map<QName, Object> keyValues;
494 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
496 this.keyValues = ImmutableMap.copyOf(keyValues);
499 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
500 this(node, ImmutableMap.of(key, value));
503 public Map<QName, Object> getKeyValues() {
508 protected int hashCodeImpl() {
509 final int prime = 31;
510 int result = super.hashCodeImpl();
511 result = prime * result;
513 for (Entry<QName, Object> entry : keyValues.entrySet()) {
514 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
520 public boolean equals(final Object obj) {
521 if (!super.equals(obj)) {
525 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
526 if (keyValues.size() != otherKeyValues.size()) {
530 for (Entry<QName, Object> entry : keyValues.entrySet()) {
531 if (!otherKeyValues.containsKey(entry.getKey())
532 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
542 public String toString() {
543 return super.toString() + '[' + keyValues + ']';
547 public String toRelativeString(final PathArgument previous) {
548 return super.toRelativeString(previous) + '[' + keyValues + ']';
553 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
556 public static final class NodeWithValue extends AbstractPathArgument {
557 private static final long serialVersionUID = -3637456085341738431L;
559 private final Object value;
561 public NodeWithValue(final QName node, final Object value) {
566 public Object getValue() {
571 protected int hashCodeImpl() {
572 final int prime = 31;
573 int result = super.hashCodeImpl();
574 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
579 public boolean equals(final Object obj) {
580 if (!super.equals(obj)) {
583 final NodeWithValue other = (NodeWithValue) obj;
584 return Objects.deepEquals(value, other.value);
588 public String toString() {
589 return super.toString() + '[' + value + ']';
593 public String toRelativeString(final PathArgument previous) {
594 return super.toRelativeString(previous) + '[' + value + ']';
599 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
600 * particular subtree.
602 * Augmentation is uniquely identified by set of all possible child nodes.
604 * to identify instance of augmentation,
605 * since RFC6020 states that <code>augment</code> that augment
606 * statement must not add multiple nodes from same namespace
607 * / module to the target node.
610 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
612 public static final class AugmentationIdentifier implements PathArgument {
613 private static final long serialVersionUID = -8122335594681936939L;
614 private final ImmutableSet<QName> childNames;
617 public QName getNodeType() {
618 // This should rather throw exception than return always null
619 throw new UnsupportedOperationException("Augmentation node has no QName");
624 * Construct new augmentation identifier using supplied set of possible
628 * Set of possible child nodes.
630 public AugmentationIdentifier(final Set<QName> childNames) {
631 this.childNames = ImmutableSet.copyOf(childNames);
635 * Returns set of all possible child nodes
637 * @return set of all possible child nodes.
639 public Set<QName> getPossibleChildNames() {
644 public String toString() {
645 final StringBuffer sb = new StringBuffer("AugmentationIdentifier{");
646 sb.append("childNames=").append(childNames).append('}');
647 return sb.toString();
651 public String toRelativeString(final PathArgument previous) {
656 public boolean equals(final Object o) {
660 if (!(o instanceof AugmentationIdentifier)) {
664 AugmentationIdentifier that = (AugmentationIdentifier) o;
665 return childNames.equals(that.childNames);
669 public int hashCode() {
670 return childNames.hashCode();
674 public int compareTo(final PathArgument o) {
675 if (!(o instanceof AugmentationIdentifier)) {
678 AugmentationIdentifier other = (AugmentationIdentifier) o;
679 Set<QName> otherChildNames = other.getPossibleChildNames();
680 int thisSize = childNames.size();
681 int otherSize = otherChildNames.size();
682 if (thisSize == otherSize) {
683 Iterator<QName> otherIterator = otherChildNames.iterator();
684 for (QName name : childNames) {
685 int c = name.compareTo(otherIterator.next());
691 } else if (thisSize < otherSize) {
699 private static class BuilderImpl implements InstanceIdentifierBuilder {
700 private final HashCodeBuilder<PathArgument> hash;
701 private final List<PathArgument> path;
703 public BuilderImpl() {
704 this.hash = new HashCodeBuilder<>();
705 this.path = new ArrayList<>();
708 public BuilderImpl(final Iterable<PathArgument> prefix, final int hash) {
709 this.path = Lists.newArrayList(prefix);
710 this.hash = new HashCodeBuilder<>(hash);
714 public InstanceIdentifierBuilder node(final QName nodeType) {
715 final PathArgument arg = new NodeIdentifier(nodeType);
717 hash.addArgument(arg);
722 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final QName key, final Object value) {
723 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, key, value);
725 hash.addArgument(arg);
730 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final Map<QName, Object> keyValues) {
731 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, keyValues);
733 hash.addArgument(arg);
739 public YangInstanceIdentifier toInstance() {
744 public YangInstanceIdentifier build() {
745 return new YangInstanceIdentifier(ImmutableList.copyOf(path), hash.toInstance());
750 public boolean contains(final YangInstanceIdentifier other) {
751 Preconditions.checkArgument(other != null, "other should not be null");
753 final Iterator<?> lit = pathArguments.iterator();
754 final Iterator<?> oit = other.pathArguments.iterator();
756 while (lit.hasNext()) {
757 if (!oit.hasNext()) {
761 if (!lit.next().equals(oit.next())) {
770 public String toString() {
772 * The toStringCache is safe, since the object contract requires
773 * immutability of the object and all objects referenced from this
775 * Used lists, maps are immutable. Path Arguments (elements) are also
776 * immutable, since the PathArgument contract requires immutability.
777 * The cache is thread-safe - if multiple computations occurs at the
778 * same time, cache will be overwritten with same result.
780 String ret = toStringCache;
782 final StringBuilder builder = new StringBuilder("/");
783 PathArgument prev = null;
784 for (PathArgument argument : getPathArguments()) {
788 builder.append(argument.toRelativeString(prev));
792 ret = builder.toString();
793 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
798 private void readObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
799 inputStream.defaultReadObject();
802 PATHARGUMENTS_FIELD.set(this, legacyPath);
803 } catch (IllegalArgumentException | IllegalAccessException e) {
804 throw new IOException(e);
808 private void writeObject(final ObjectOutputStream outputStream) throws IOException {
810 * This may look strange, but what we are doing here is side-stepping the fact
811 * that pathArguments is not generally serializable. We are forcing instantiation
812 * of the legacy path, which is an ImmutableList (thus Serializable) and write
813 * it out. The read path does the opposite -- it reads the legacyPath and then
814 * uses invocation API to set the field.
817 outputStream.defaultWriteObject();