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.annotations.Beta;
10 import com.google.common.base.Optional;
11 import com.google.common.base.Preconditions;
12 import com.google.common.collect.ImmutableMap;
13 import com.google.common.collect.ImmutableSet;
14 import com.google.common.collect.Iterables;
15 import java.io.Serializable;
16 import java.lang.reflect.Array;
17 import java.util.Arrays;
18 import java.util.Collection;
19 import java.util.Iterator;
20 import java.util.List;
22 import java.util.Map.Entry;
23 import java.util.Objects;
25 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
26 import javax.annotation.Nonnull;
27 import javax.annotation.Nullable;
28 import org.opendaylight.yangtools.concepts.Builder;
29 import org.opendaylight.yangtools.concepts.Immutable;
30 import org.opendaylight.yangtools.concepts.Path;
31 import org.opendaylight.yangtools.util.HashCodeBuilder;
32 import org.opendaylight.yangtools.yang.common.QName;
33 import org.opendaylight.yangtools.yang.common.QNameModule;
34 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
37 * Unique identifier of a particular node instance in the data tree.
40 * Java representation of YANG Built-in type <code>instance-identifier</code>,
41 * which conceptually is XPath expression minimized to uniquely identify element
42 * in data tree which conforms to constraints maintained by YANG Model,
43 * effectively this makes Instance Identifier a path to element in data tree.
45 * Constraints put in YANG specification on instance-identifier allowed it to be
46 * effectively represented in Java and it's evaluation does not require
47 * full-blown XPath processor.
49 * <h3>Path Arguments</h3>
50 * Path to the node represented in instance identifier consists of
51 * {@link PathArgument} which carries necessary information to uniquely identify
52 * node on particular level in the subtree.
55 * <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
56 * <code>0..1</code> in particular subtree in data tree.</li>
57 * <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
58 * which has cardinality <code>0..n</code>.</li>
59 * <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
60 * <code>leaf-list</code> node.</li>
61 * <li>{@link AugmentationIdentifier} - Identifier of instance of
62 * <code>augmentation</code> node.</li>
66 * @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
68 public abstract class YangInstanceIdentifier extends IterablePathArguments implements Path<YangInstanceIdentifier>, Immutable, Serializable {
70 * An empty {@link YangInstanceIdentifier}. It corresponds to the path of the conceptual
71 * root of the YANG namespace.
73 public static final YangInstanceIdentifier EMPTY = FixedYangInstanceIdentifier.EMPTY_INSTANCE;
75 private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
76 AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
77 private static final long serialVersionUID = 4L;
79 private final int hash;
80 private transient volatile String toStringCache = null;
82 // Package-private to prevent outside subclassing
83 YangInstanceIdentifier(final int hash) {
87 @Nonnull abstract YangInstanceIdentifier createRelativeIdentifier(int skipFromRoot);
88 @Nonnull abstract Collection<PathArgument> tryPathArguments();
89 @Nonnull abstract Collection<PathArgument> tryReversePathArguments();
92 * Check if this instance identifier has empty path arguments, e.g. it is
93 * empty and corresponds to {@link #EMPTY}.
95 * @return True if this instance identifier is empty, false otherwise.
97 public abstract boolean isEmpty();
100 * Return an optimized version of this identifier, useful when the identifier
101 * will be used very frequently.
103 * @return A optimized equivalent instance.
106 public abstract YangInstanceIdentifier toOptimized();
109 * Return the conceptual parent {@link YangInstanceIdentifier}, which has
110 * one item less in {@link #getPathArguments()}.
112 * @return Parent {@link YangInstanceIdentifier}, or null if this is object is {@link #EMPTY}.
114 @Nullable public abstract YangInstanceIdentifier getParent();
117 * Returns a list of path arguments.
119 * @deprecated Use {@link #getPathArguments()} instead.
120 * @return Immutable list of path arguments.
123 public final List<PathArgument> getPath() {
124 return getPathArguments();
128 * Returns an ordered iteration of path arguments.
130 * @return Immutable iteration of path arguments.
133 public abstract List<PathArgument> getPathArguments();
136 * Returns an iterable of path arguments in reverse order. This is useful
137 * when walking up a tree organized this way.
139 * @return Immutable iterable of path arguments in reverse order.
142 public abstract List<PathArgument> getReversePathArguments();
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 abstract PathArgument getLastPathArgument();
152 public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
153 if (Iterables.isEmpty(path)) {
157 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
158 for (PathArgument a : path) {
162 return FixedYangInstanceIdentifier.create(path, hash.build());
165 public static YangInstanceIdentifier create(final PathArgument... path) {
166 // We are forcing a copy, since we cannot trust the user
167 return create(Arrays.asList(path));
171 public final int hashCode() {
173 * The caching is safe, since the object contract requires
174 * immutability of the object and all objects referenced from this
176 * Used lists, maps are immutable. Path Arguments (elements) are also
177 * immutable, since the PathArgument contract requires immutability.
182 boolean pathArgumentsEqual(final YangInstanceIdentifier other) {
183 return Iterables.elementsEqual(getPathArguments(), other.getPathArguments());
187 public boolean equals(final Object obj) {
191 if (!(obj instanceof YangInstanceIdentifier)) {
194 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
195 if (this.hashCode() != obj.hashCode()) {
199 return pathArgumentsEqual(other);
203 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
205 * @param name QName of {@link NodeIdentifier}
206 * @return Instance Identifier with additional path argument added to the end.
208 public final YangInstanceIdentifier node(final QName name) {
209 return node(new NodeIdentifier(name));
214 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
216 * @param arg Path argument which should be added to the end
217 * @return Instance Identifier with additional path argument added to the end.
219 public final YangInstanceIdentifier node(final PathArgument arg) {
220 return new StackedYangInstanceIdentifier(this, arg, HashCodeBuilder.nextHashCode(hash, arg));
224 * Get the relative path from an ancestor. This method attempts to perform
225 * the reverse of concatenating a base (ancestor) and a path.
228 * Ancestor against which the relative path should be calculated
229 * @return This object's relative path from parent, or Optional.absent() if
230 * the specified parent is not in fact an ancestor of this object.
232 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
233 final Iterator<?> lit = getPathArguments().iterator();
234 final Iterator<?> oit = ancestor.getPathArguments().iterator();
237 while (oit.hasNext()) {
238 // Ancestor is not really an ancestor
239 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
240 return Optional.absent();
247 return Optional.of(this);
249 if (!lit.hasNext()) {
250 return Optional.of(EMPTY);
253 return Optional.of(createRelativeIdentifier(common));
257 public final boolean contains(final YangInstanceIdentifier other) {
258 Preconditions.checkArgument(other != null, "other should not be null");
260 final Iterator<?> lit = getPathArguments().iterator();
261 final Iterator<?> oit = other.getPathArguments().iterator();
263 while (lit.hasNext()) {
264 if (!oit.hasNext()) {
268 if (!lit.next().equals(oit.next())) {
277 public final String toString() {
279 * The toStringCache is safe, since the object contract requires
280 * immutability of the object and all objects referenced from this
282 * Used lists, maps are immutable. Path Arguments (elements) are also
283 * immutable, since the PathArgument contract requires immutability.
284 * The cache is thread-safe - if multiple computations occurs at the
285 * same time, cache will be overwritten with same result.
287 String ret = toStringCache;
289 final StringBuilder builder = new StringBuilder("/");
290 PathArgument prev = null;
291 for (PathArgument argument : getPathArguments()) {
295 builder.append(argument.toRelativeString(prev));
299 ret = builder.toString();
300 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
305 private static int hashCode(final Object value) {
310 if (byte[].class.equals(value.getClass())) {
311 return Arrays.hashCode((byte[]) value);
314 if (value.getClass().isArray()) {
316 int length = Array.getLength(value);
317 for (int i = 0; i < length; i++) {
318 hash += Objects.hashCode(Array.get(value, i));
324 return Objects.hashCode(value);
327 // Static factories & helpers
330 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
332 * @param name QName of first node identifier
333 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
335 public static YangInstanceIdentifier of(final QName name) {
336 return create(new NodeIdentifier(name));
340 * Returns new builder for InstanceIdentifier with empty path arguments.
342 * @return new builder for InstanceIdentifier with empty path arguments.
344 public static InstanceIdentifierBuilder builder() {
345 return new YangInstanceIdentifierBuilder();
350 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
352 * @param origin InstanceIdentifier from which path arguments are copied.
353 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
355 public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
356 return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
360 * Path argument / component of InstanceIdentifier
362 * Path argument uniquely identifies node in data tree on particular
365 * This interface itself is used as common parent for actual
366 * path arguments types and should not be implemented by user code.
368 * Path arguments SHOULD contain only minimum of information
369 * required to uniquely identify node on particular subtree level.
371 * For actual path arguments types see:
373 * <li>{@link NodeIdentifier} - Identifier of container or leaf
374 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
375 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
376 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
379 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
381 * If applicable returns unique QName of data node as defined in YANG
384 * This method may return null, if the corresponding schema node, does
385 * not have QName associated, such as in cases of augmentations.
392 * Return the string representation of this object for use in context
393 * provided by a previous object. This method can be implemented in
394 * terms of {@link #toString()}, but implementations are encourage to
395 * reuse any context already emitted by the previous object.
397 * @param previous Previous path argument
398 * @return String representation
400 String toRelativeString(PathArgument previous);
403 private static abstract class AbstractPathArgument implements PathArgument {
404 private static final long serialVersionUID = -4546547994250849340L;
405 private final QName nodeType;
406 private transient int hashValue;
407 private volatile transient boolean hashGuard = false;
409 protected AbstractPathArgument(final QName nodeType) {
410 this.nodeType = Preconditions.checkNotNull(nodeType);
414 public final QName getNodeType() {
419 public int compareTo(final PathArgument o) {
420 return nodeType.compareTo(o.getNodeType());
423 protected int hashCodeImpl() {
424 return 31 + getNodeType().hashCode();
428 public final int hashCode() {
430 hashValue = hashCodeImpl();
438 public boolean equals(final Object obj) {
442 if (obj == null || this.getClass() != obj.getClass()) {
446 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
450 public String toString() {
451 return getNodeType().toString();
455 public String toRelativeString(final PathArgument previous) {
456 if (previous instanceof AbstractPathArgument) {
457 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
458 if (getNodeType().getModule().equals(mod)) {
459 return getNodeType().getLocalName();
463 return getNodeType().toString();
468 * Fluent Builder of Instance Identifier instances
470 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
472 * Adds a {@link PathArgument} to to path arguments of resulting instance identifier.
474 * @param arg A {@link PathArgument} to be added
475 * @return this builder
477 InstanceIdentifierBuilder node(PathArgument arg);
480 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
482 * @param nodeType QName of {@link NodeIdentifier} which will be added
483 * @return this builder
485 InstanceIdentifierBuilder node(QName nodeType);
488 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
490 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
491 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
492 * @return this builder
494 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
497 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
499 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
500 * @param key QName of key which will be added
501 * @param value value of key which will be added
502 * @return this builder
504 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
508 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
510 * @return {@link YangInstanceIdentifier}
513 YangInstanceIdentifier build();
516 * @deprecated use #build()
519 YangInstanceIdentifier toInstance();
523 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
524 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
526 public static final class NodeIdentifier extends AbstractPathArgument {
527 private static final long serialVersionUID = -2255888212390871347L;
529 public NodeIdentifier(final QName node) {
535 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
538 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
539 private static final long serialVersionUID = -4787195606494761540L;
541 private final Map<QName, Object> keyValues;
543 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
545 this.keyValues = ImmutableMap.copyOf(keyValues);
548 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
549 this(node, ImmutableMap.of(key, value));
552 public Map<QName, Object> getKeyValues() {
557 protected int hashCodeImpl() {
558 final int prime = 31;
559 int result = super.hashCodeImpl();
560 result = prime * result;
562 for (Entry<QName, Object> entry : keyValues.entrySet()) {
563 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
569 public boolean equals(final Object obj) {
570 if (!super.equals(obj)) {
574 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
576 // TODO: benchmark to see if just calling equals() on the two maps is not faster
577 if (keyValues == otherKeyValues) {
580 if (keyValues.size() != otherKeyValues.size()) {
584 for (Entry<QName, Object> entry : keyValues.entrySet()) {
585 if (!otherKeyValues.containsKey(entry.getKey())
586 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
596 public String toString() {
597 return super.toString() + '[' + keyValues + ']';
601 public String toRelativeString(final PathArgument previous) {
602 return super.toRelativeString(previous) + '[' + keyValues + ']';
607 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
610 public static final class NodeWithValue extends AbstractPathArgument {
611 private static final long serialVersionUID = -3637456085341738431L;
613 private final Object value;
615 public NodeWithValue(final QName node, final Object value) {
620 public Object getValue() {
625 protected int hashCodeImpl() {
626 final int prime = 31;
627 int result = super.hashCodeImpl();
628 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
633 public boolean equals(final Object obj) {
634 if (!super.equals(obj)) {
637 final NodeWithValue other = (NodeWithValue) obj;
638 return Objects.deepEquals(value, other.value);
642 public String toString() {
643 return super.toString() + '[' + value + ']';
647 public String toRelativeString(final PathArgument previous) {
648 return super.toRelativeString(previous) + '[' + value + ']';
653 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
654 * particular subtree.
656 * Augmentation is uniquely identified by set of all possible child nodes.
658 * to identify instance of augmentation,
659 * since RFC6020 states that <code>augment</code> that augment
660 * statement must not add multiple nodes from same namespace
661 * / module to the target node.
664 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
666 public static final class AugmentationIdentifier implements PathArgument {
667 private static final long serialVersionUID = -8122335594681936939L;
668 private final ImmutableSet<QName> childNames;
671 public QName getNodeType() {
672 // This should rather throw exception than return always null
673 throw new UnsupportedOperationException("Augmentation node has no QName");
678 * Construct new augmentation identifier using supplied set of possible
682 * Set of possible child nodes.
684 public AugmentationIdentifier(final Set<QName> childNames) {
685 this.childNames = ImmutableSet.copyOf(childNames);
689 * Returns set of all possible child nodes
691 * @return set of all possible child nodes.
693 public Set<QName> getPossibleChildNames() {
698 public String toString() {
699 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
700 sb.append("childNames=").append(childNames).append('}');
701 return sb.toString();
705 public String toRelativeString(final PathArgument previous) {
710 public boolean equals(final Object o) {
714 if (!(o instanceof AugmentationIdentifier)) {
718 AugmentationIdentifier that = (AugmentationIdentifier) o;
719 return childNames.equals(that.childNames);
723 public int hashCode() {
724 return childNames.hashCode();
728 public int compareTo(final PathArgument o) {
729 if (!(o instanceof AugmentationIdentifier)) {
732 AugmentationIdentifier other = (AugmentationIdentifier) o;
733 Set<QName> otherChildNames = other.getPossibleChildNames();
734 int thisSize = childNames.size();
735 int otherSize = otherChildNames.size();
736 if (thisSize == otherSize) {
737 Iterator<QName> otherIterator = otherChildNames.iterator();
738 for (QName name : childNames) {
739 int c = name.compareTo(otherIterator.next());
745 } else if (thisSize < otherSize) {