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 {
74 @SuppressWarnings("rawtypes")
75 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, ImmutableList> LEGACYPATH_UPDATER =
76 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, ImmutableList.class, "legacyPath");
77 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
78 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
79 private static final YangInstanceIdentifier EMPTY = trustedCreate(Collections.<PathArgument>emptyList());
80 private static final Field PATHARGUMENTS_FIELD;
82 private static final long serialVersionUID = 3L;
83 private transient final Iterable<PathArgument> pathArguments;
84 private final int hash;
86 private volatile ImmutableList<PathArgument> legacyPath = null;
87 private transient volatile String toStringCache = null;
92 f = YangInstanceIdentifier.class.getDeclaredField("pathArguments");
93 } catch (NoSuchFieldException | SecurityException e) {
94 throw new ExceptionInInitializerError(e);
96 f.setAccessible(true);
98 PATHARGUMENTS_FIELD = f;
101 private final ImmutableList<PathArgument> getLegacyPath() {
102 // Temporary variable saves a volatile read
103 ImmutableList<PathArgument> ret = legacyPath;
105 // We could have used a synchronized block, but the window is quite
106 // small and worst that can happen is duplicate object construction.
107 ret = ImmutableList.copyOf(pathArguments);
108 LEGACYPATH_UPDATER.lazySet(this, ret);
115 * Returns a list of path arguments.
117 * @deprecated Use {@link #getPathArguments()} instead.
118 * @return Immutable list of path arguments.
121 public List<PathArgument> getPath() {
122 return getLegacyPath();
126 * Returns an ordered iteration of path arguments.
128 * @return Immutable iteration of path arguments.
130 public Iterable<PathArgument> getPathArguments() {
131 return pathArguments;
135 * Returns an iterable of path arguments in reverse order. This is useful
136 * when walking up a tree organized this way.
138 * @return Immutable iterable of path arguments in reverse order.
140 public Iterable<PathArgument> getReversePathArguments() {
141 return getLegacyPath().reverse();
145 * Returns the last PathArgument. This is equivalent of iterating
146 * to the last element of the iterable returned by {@link #getPathArguments()}.
148 * @return The last past argument, or null if there are no PathArguments.
150 public PathArgument getLastPathArgument() {
151 return Iterables.getFirst(getReversePathArguments(), null);
154 private YangInstanceIdentifier(final Iterable<PathArgument> path, final int hash) {
155 this.pathArguments = Preconditions.checkNotNull(path, "path must not be null.");
159 private static final YangInstanceIdentifier trustedCreate(final Iterable<PathArgument> path) {
160 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
161 for (PathArgument a : path) {
165 return new YangInstanceIdentifier(path, hash.build());
168 public static final YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
169 if (Iterables.isEmpty(path)) {
173 return trustedCreate(ImmutableList.copyOf(path));
176 public static final YangInstanceIdentifier create(final PathArgument... path) {
177 // We are forcing a copy, since we cannot trust the user
178 return create(Arrays.asList(path));
182 public int hashCode() {
184 * The caching is safe, since the object contract requires
185 * immutability of the object and all objects referenced from this
187 * Used lists, maps are immutable. Path Arguments (elements) are also
188 * immutable, since the PathArgument contract requires immutability.
194 public boolean equals(final Object obj) {
201 if (getClass() != obj.getClass()) {
204 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
205 if (this.hashCode() != obj.hashCode()) {
208 return Iterables.elementsEqual(pathArguments, other.pathArguments);
212 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
214 * @param name QName of {@link NodeIdentifier}
215 * @return Instance Identifier with additional path argument added to the end.
217 public YangInstanceIdentifier node(final QName name) {
218 return node(new NodeIdentifier(name));
223 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
225 * @param arg Path argument which should be added to the end
226 * @return Instance Identifier with additional path argument added to the end.
228 public YangInstanceIdentifier node(final PathArgument arg) {
229 return new YangInstanceIdentifier(Iterables.concat(pathArguments, Collections.singleton(arg)), HashCodeBuilder.nextHashCode(hash, arg));
233 * Get the relative path from an ancestor. This method attempts to perform
234 * the reverse of concatenating a base (ancestor) and a path.
237 * Ancestor against which the relative path should be calculated
238 * @return This object's relative path from parent, or Optional.absent() if
239 * the specified parent is not in fact an ancestor of this object.
241 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
242 final Iterator<?> lit = pathArguments.iterator();
243 final Iterator<?> oit = ancestor.pathArguments.iterator();
246 while (oit.hasNext()) {
247 // Ancestor is not really an ancestor
248 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
249 return Optional.absent();
256 return Optional.of(this);
258 if (!lit.hasNext()) {
259 return Optional.of(EMPTY);
261 return Optional.of(trustedCreate(Iterables.skip(pathArguments, common)));
264 private static int hashCode(final Object value) {
269 if (value.getClass().equals(byte[].class)) {
270 return Arrays.hashCode((byte[]) value);
273 if (value.getClass().isArray()) {
275 int length = Array.getLength(value);
276 for (int i = 0; i < length; i++) {
277 hash += Objects.hashCode(Array.get(value, i));
283 return Objects.hashCode(value);
286 // Static factories & helpers
290 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
292 * @param name QName of first node identifier
293 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
295 public static YangInstanceIdentifier of(final QName name) {
296 return create(new NodeIdentifier(name));
301 * Returns new builder for InstanceIdentifier with empty path arguments.
303 * @return new builder for InstanceIdentifier with empty path arguments.
305 static public InstanceIdentifierBuilder builder() {
306 return new BuilderImpl();
311 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
313 * @param origin Instace Identifier from which path arguments are copied.
314 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
316 static public InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
317 return new BuilderImpl(origin.getPathArguments(), origin.hashCode());
321 * Path argument / component of InstanceIdentifier
323 * Path argument uniquely identifies node in data tree on particular
326 * This interface itself is used as common parent for actual
327 * path arguments types and should not be implemented by user code.
329 * Path arguments SHOULD contain only minimum of information
330 * required to uniquely identify node on particular subtree level.
332 * For actual path arguments types see:
334 * <li>{@link NodeIdentifier} - Identifier of container or leaf
335 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
336 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
337 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
340 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
342 * If applicable returns unique QName of data node as defined in YANG
345 * This method may return null, if the corresponding schema node, does
346 * not have QName associated, such as in cases of augmentations.
353 * Return the string representation of this object for use in context
354 * provided by a previous object. This method can be implemented in
355 * terms of {@link #toString()}, but implementations are encourage to
356 * reuse any context already emitted by the previous object.
358 * @param previous Previous path argument
359 * @return String representation
361 String toRelativeString(PathArgument previous);
364 private static abstract class AbstractPathArgument implements PathArgument {
365 private static final AtomicReferenceFieldUpdater<AbstractPathArgument, Integer> HASH_UPDATER =
366 AtomicReferenceFieldUpdater.newUpdater(AbstractPathArgument.class, Integer.class, "hash");
367 private static final long serialVersionUID = -4546547994250849340L;
368 private final QName nodeType;
369 private volatile transient Integer hash = null;
371 protected AbstractPathArgument(final QName nodeType) {
372 this.nodeType = Preconditions.checkNotNull(nodeType);
376 public final QName getNodeType() {
381 public int compareTo(final PathArgument o) {
382 return nodeType.compareTo(o.getNodeType());
385 protected int hashCodeImpl() {
386 return 31 + getNodeType().hashCode();
390 public final int hashCode() {
393 ret = hashCodeImpl();
394 HASH_UPDATER.lazySet(this, ret);
401 public boolean equals(final Object obj) {
405 if (obj == null || this.getClass() != obj.getClass()) {
409 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
413 public String toString() {
414 return getNodeType().toString();
418 public String toRelativeString(final PathArgument previous) {
419 if (previous instanceof AbstractPathArgument) {
420 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
421 if (getNodeType().getModule().equals(mod)) {
422 return getNodeType().getLocalName();
426 return getNodeType().toString();
431 * Fluent Builder of Instance Identifier instances
433 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
435 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
437 * @param nodeType QName of {@link NodeIdentifier} which will be added
438 * @return this builder
440 InstanceIdentifierBuilder node(QName nodeType);
443 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
445 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
446 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
447 * @return this builder
449 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
452 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
454 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
455 * @param key QName of key which will be added
456 * @param value value of key which will be added
457 * @return this builder
459 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
463 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
465 * @return {@link YangInstanceIdentifier}
468 YangInstanceIdentifier build();
471 * @deprecated use #build()
474 YangInstanceIdentifier toInstance();
478 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
479 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
481 public static final class NodeIdentifier extends AbstractPathArgument {
482 private static final long serialVersionUID = -2255888212390871347L;
484 public NodeIdentifier(final QName node) {
490 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
493 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
494 private static final long serialVersionUID = -4787195606494761540L;
496 private final Map<QName, Object> keyValues;
498 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
500 this.keyValues = ImmutableMap.copyOf(keyValues);
503 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
504 this(node, ImmutableMap.of(key, value));
507 public Map<QName, Object> getKeyValues() {
512 protected int hashCodeImpl() {
513 final int prime = 31;
514 int result = super.hashCodeImpl();
515 result = prime * result;
517 for (Entry<QName, Object> entry : keyValues.entrySet()) {
518 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
524 public boolean equals(final Object obj) {
525 if (!super.equals(obj)) {
529 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
530 if (keyValues.size() != otherKeyValues.size()) {
534 for (Entry<QName, Object> entry : keyValues.entrySet()) {
535 if (!otherKeyValues.containsKey(entry.getKey())
536 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
546 public String toString() {
547 return super.toString() + '[' + keyValues + ']';
551 public String toRelativeString(final PathArgument previous) {
552 return super.toRelativeString(previous) + '[' + keyValues + ']';
557 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
560 public static final class NodeWithValue extends AbstractPathArgument {
561 private static final long serialVersionUID = -3637456085341738431L;
563 private final Object value;
565 public NodeWithValue(final QName node, final Object value) {
570 public Object getValue() {
575 protected int hashCodeImpl() {
576 final int prime = 31;
577 int result = super.hashCodeImpl();
578 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
583 public boolean equals(final Object obj) {
584 if (!super.equals(obj)) {
587 final NodeWithValue other = (NodeWithValue) obj;
588 return Objects.deepEquals(value, other.value);
592 public String toString() {
593 return super.toString() + '[' + value + ']';
597 public String toRelativeString(final PathArgument previous) {
598 return super.toRelativeString(previous) + '[' + value + ']';
603 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
604 * particular subtree.
606 * Augmentation is uniquely identified by set of all possible child nodes.
608 * to identify instance of augmentation,
609 * since RFC6020 states that <code>augment</code> that augment
610 * statement must not add multiple nodes from same namespace
611 * / module to the target node.
614 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
616 public static final class AugmentationIdentifier implements PathArgument {
617 private static final long serialVersionUID = -8122335594681936939L;
618 private final ImmutableSet<QName> childNames;
621 public QName getNodeType() {
622 // This should rather throw exception than return always null
623 throw new UnsupportedOperationException("Augmentation node has no QName");
628 * Construct new augmentation identifier using supplied set of possible
632 * Set of possible child nodes.
634 public AugmentationIdentifier(final Set<QName> childNames) {
635 this.childNames = ImmutableSet.copyOf(childNames);
639 * Returns set of all possible child nodes
641 * @return set of all possible child nodes.
643 public Set<QName> getPossibleChildNames() {
648 public String toString() {
649 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
650 sb.append("childNames=").append(childNames).append('}');
651 return sb.toString();
655 public String toRelativeString(final PathArgument previous) {
660 public boolean equals(final Object o) {
664 if (!(o instanceof AugmentationIdentifier)) {
668 AugmentationIdentifier that = (AugmentationIdentifier) o;
669 return childNames.equals(that.childNames);
673 public int hashCode() {
674 return childNames.hashCode();
678 public int compareTo(final PathArgument o) {
679 if (!(o instanceof AugmentationIdentifier)) {
682 AugmentationIdentifier other = (AugmentationIdentifier) o;
683 Set<QName> otherChildNames = other.getPossibleChildNames();
684 int thisSize = childNames.size();
685 int otherSize = otherChildNames.size();
686 if (thisSize == otherSize) {
687 Iterator<QName> otherIterator = otherChildNames.iterator();
688 for (QName name : childNames) {
689 int c = name.compareTo(otherIterator.next());
695 } else if (thisSize < otherSize) {
703 private static class BuilderImpl implements InstanceIdentifierBuilder {
704 private final HashCodeBuilder<PathArgument> hash;
705 private final List<PathArgument> path;
707 public BuilderImpl() {
708 this.hash = new HashCodeBuilder<>();
709 this.path = new ArrayList<>();
712 public BuilderImpl(final Iterable<PathArgument> prefix, final int hash) {
713 this.path = Lists.newArrayList(prefix);
714 this.hash = new HashCodeBuilder<>(hash);
718 public InstanceIdentifierBuilder node(final QName nodeType) {
719 final PathArgument arg = new NodeIdentifier(nodeType);
721 hash.addArgument(arg);
726 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final QName key, final Object value) {
727 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, key, value);
729 hash.addArgument(arg);
734 public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final Map<QName, Object> keyValues) {
735 final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, keyValues);
737 hash.addArgument(arg);
743 public YangInstanceIdentifier toInstance() {
748 public YangInstanceIdentifier build() {
749 return new YangInstanceIdentifier(ImmutableList.copyOf(path), hash.build());
754 public boolean contains(final YangInstanceIdentifier other) {
755 Preconditions.checkArgument(other != null, "other should not be null");
757 final Iterator<?> lit = pathArguments.iterator();
758 final Iterator<?> oit = other.pathArguments.iterator();
760 while (lit.hasNext()) {
761 if (!oit.hasNext()) {
765 if (!lit.next().equals(oit.next())) {
774 public String toString() {
776 * The toStringCache is safe, since the object contract requires
777 * immutability of the object and all objects referenced from this
779 * Used lists, maps are immutable. Path Arguments (elements) are also
780 * immutable, since the PathArgument contract requires immutability.
781 * The cache is thread-safe - if multiple computations occurs at the
782 * same time, cache will be overwritten with same result.
784 String ret = toStringCache;
786 final StringBuilder builder = new StringBuilder("/");
787 PathArgument prev = null;
788 for (PathArgument argument : getPathArguments()) {
792 builder.append(argument.toRelativeString(prev));
796 ret = builder.toString();
797 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
802 private void readObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
803 inputStream.defaultReadObject();
806 PATHARGUMENTS_FIELD.set(this, legacyPath);
807 } catch (IllegalArgumentException | IllegalAccessException e) {
808 throw new IOException(e);
812 private Object readResolve() throws ObjectStreamException {
813 return legacyPath.isEmpty() ? EMPTY : this;
816 private void writeObject(final ObjectOutputStream outputStream) throws IOException {
818 * This may look strange, but what we are doing here is side-stepping the fact
819 * that pathArguments is not generally serializable. We are forcing instantiation
820 * of the legacy path, which is an ImmutableList (thus Serializable) and write
821 * it out. The read path does the opposite -- it reads the legacyPath and then
822 * uses invocation API to set the field.
825 outputStream.defaultWriteObject();