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 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 an ordered iteration of path arguments.
119 * @return Immutable iteration of path arguments.
121 public abstract List<PathArgument> getPathArguments();
124 * Returns an iterable of path arguments in reverse order. This is useful
125 * when walking up a tree organized this way.
127 * @return Immutable iterable of path arguments in reverse order.
129 public abstract List<PathArgument> getReversePathArguments();
132 * Returns the last PathArgument. This is equivalent of iterating
133 * to the last element of the iterable returned by {@link #getPathArguments()}.
135 * @return The last past argument, or null if there are no PathArguments.
137 public abstract PathArgument getLastPathArgument();
139 public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
140 if (Iterables.isEmpty(path)) {
144 final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
145 for (PathArgument a : path) {
149 return FixedYangInstanceIdentifier.create(path, hash.build());
152 public static YangInstanceIdentifier create(final PathArgument... path) {
153 // We are forcing a copy, since we cannot trust the user
154 return create(Arrays.asList(path));
158 public final int hashCode() {
160 * The caching is safe, since the object contract requires
161 * immutability of the object and all objects referenced from this
163 * Used lists, maps are immutable. Path Arguments (elements) are also
164 * immutable, since the PathArgument contract requires immutability.
169 boolean pathArgumentsEqual(final YangInstanceIdentifier other) {
170 return Iterables.elementsEqual(getPathArguments(), other.getPathArguments());
174 public boolean equals(final Object obj) {
178 if (!(obj instanceof YangInstanceIdentifier)) {
181 YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
182 if (this.hashCode() != obj.hashCode()) {
186 return pathArgumentsEqual(other);
190 * Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
192 * @param name QName of {@link NodeIdentifier}
193 * @return Instance Identifier with additional path argument added to the end.
195 public final YangInstanceIdentifier node(final QName name) {
196 return node(new NodeIdentifier(name));
201 * Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
203 * @param arg Path argument which should be added to the end
204 * @return Instance Identifier with additional path argument added to the end.
206 public final YangInstanceIdentifier node(final PathArgument arg) {
207 return new StackedYangInstanceIdentifier(this, arg, HashCodeBuilder.nextHashCode(hash, arg));
211 * Get the relative path from an ancestor. This method attempts to perform
212 * the reverse of concatenating a base (ancestor) and a path.
215 * Ancestor against which the relative path should be calculated
216 * @return This object's relative path from parent, or Optional.absent() if
217 * the specified parent is not in fact an ancestor of this object.
219 public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
220 final Iterator<?> lit = getPathArguments().iterator();
221 final Iterator<?> oit = ancestor.getPathArguments().iterator();
224 while (oit.hasNext()) {
225 // Ancestor is not really an ancestor
226 if (!lit.hasNext() || !lit.next().equals(oit.next())) {
227 return Optional.absent();
234 return Optional.of(this);
236 if (!lit.hasNext()) {
237 return Optional.of(EMPTY);
240 return Optional.of(createRelativeIdentifier(common));
244 public final boolean contains(final YangInstanceIdentifier other) {
245 Preconditions.checkArgument(other != null, "other should not be null");
247 final Iterator<?> lit = getPathArguments().iterator();
248 final Iterator<?> oit = other.getPathArguments().iterator();
250 while (lit.hasNext()) {
251 if (!oit.hasNext()) {
255 if (!lit.next().equals(oit.next())) {
264 public final String toString() {
266 * The toStringCache is safe, since the object contract requires
267 * immutability of the object and all objects referenced from this
269 * Used lists, maps are immutable. Path Arguments (elements) are also
270 * immutable, since the PathArgument contract requires immutability.
271 * The cache is thread-safe - if multiple computations occurs at the
272 * same time, cache will be overwritten with same result.
274 String ret = toStringCache;
276 final StringBuilder builder = new StringBuilder("/");
277 PathArgument prev = null;
278 for (PathArgument argument : getPathArguments()) {
282 builder.append(argument.toRelativeString(prev));
286 ret = builder.toString();
287 TOSTRINGCACHE_UPDATER.lazySet(this, ret);
292 private static int hashCode(final Object value) {
297 if (byte[].class.equals(value.getClass())) {
298 return Arrays.hashCode((byte[]) value);
301 if (value.getClass().isArray()) {
303 int length = Array.getLength(value);
304 for (int i = 0; i < length; i++) {
305 hash += Objects.hashCode(Array.get(value, i));
311 return Objects.hashCode(value);
314 // Static factories & helpers
317 * Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
319 * @param name QName of first node identifier
320 * @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
322 public static YangInstanceIdentifier of(final QName name) {
323 return create(new NodeIdentifier(name));
327 * Returns new builder for InstanceIdentifier with empty path arguments.
329 * @return new builder for InstanceIdentifier with empty path arguments.
331 public static InstanceIdentifierBuilder builder() {
332 return new YangInstanceIdentifierBuilder();
337 * Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
339 * @param origin InstanceIdentifier from which path arguments are copied.
340 * @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
342 public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
343 return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
347 * Path argument / component of InstanceIdentifier
349 * Path argument uniquely identifies node in data tree on particular
352 * This interface itself is used as common parent for actual
353 * path arguments types and should not be implemented by user code.
355 * Path arguments SHOULD contain only minimum of information
356 * required to uniquely identify node on particular subtree level.
358 * For actual path arguments types see:
360 * <li>{@link NodeIdentifier} - Identifier of container or leaf
361 * <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
362 * <li>{@link AugmentationIdentifier} - Identifier of augmentation
363 * <li>{@link NodeWithValue} - Identifier of leaf-list entry
366 public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
368 * If applicable returns unique QName of data node as defined in YANG
371 * This method may return null, if the corresponding schema node, does
372 * not have QName associated, such as in cases of augmentations.
379 * Return the string representation of this object for use in context
380 * provided by a previous object. This method can be implemented in
381 * terms of {@link #toString()}, but implementations are encourage to
382 * reuse any context already emitted by the previous object.
384 * @param previous Previous path argument
385 * @return String representation
387 String toRelativeString(PathArgument previous);
390 private static abstract class AbstractPathArgument implements PathArgument {
391 private static final long serialVersionUID = -4546547994250849340L;
392 private final QName nodeType;
393 private transient int hashValue;
394 private volatile transient boolean hashGuard = false;
396 protected AbstractPathArgument(final QName nodeType) {
397 this.nodeType = Preconditions.checkNotNull(nodeType);
401 public final QName getNodeType() {
406 public int compareTo(final PathArgument o) {
407 return nodeType.compareTo(o.getNodeType());
410 protected int hashCodeImpl() {
411 return 31 + getNodeType().hashCode();
415 public final int hashCode() {
417 hashValue = hashCodeImpl();
425 public boolean equals(final Object obj) {
429 if (obj == null || this.getClass() != obj.getClass()) {
433 return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
437 public String toString() {
438 return getNodeType().toString();
442 public String toRelativeString(final PathArgument previous) {
443 if (previous instanceof AbstractPathArgument) {
444 final QNameModule mod = ((AbstractPathArgument)previous).getNodeType().getModule();
445 if (getNodeType().getModule().equals(mod)) {
446 return getNodeType().getLocalName();
450 return getNodeType().toString();
455 * Fluent Builder of Instance Identifier instances
457 public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
459 * Adds a {@link PathArgument} to to path arguments of resulting instance identifier.
461 * @param arg A {@link PathArgument} to be added
462 * @return this builder
464 InstanceIdentifierBuilder node(PathArgument arg);
467 * Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
469 * @param nodeType QName of {@link NodeIdentifier} which will be added
470 * @return this builder
472 InstanceIdentifierBuilder node(QName nodeType);
475 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
477 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
478 * @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
479 * @return this builder
481 InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
484 * Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
486 * @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
487 * @param key QName of key which will be added
488 * @param value value of key which will be added
489 * @return this builder
491 InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
495 * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
497 * @return {@link YangInstanceIdentifier}
500 YangInstanceIdentifier build();
503 * @deprecated use #build()
506 YangInstanceIdentifier toInstance();
510 * Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
511 * {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
513 public static final class NodeIdentifier extends AbstractPathArgument {
514 private static final long serialVersionUID = -2255888212390871347L;
516 public NodeIdentifier(final QName node) {
522 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
525 public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
526 private static final long serialVersionUID = -4787195606494761540L;
528 private final Map<QName, Object> keyValues;
530 public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
532 this.keyValues = ImmutableMap.copyOf(keyValues);
535 public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
536 this(node, ImmutableMap.of(key, value));
539 public Map<QName, Object> getKeyValues() {
544 protected int hashCodeImpl() {
545 final int prime = 31;
546 int result = super.hashCodeImpl();
547 result = prime * result;
549 for (Entry<QName, Object> entry : keyValues.entrySet()) {
550 result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
556 public boolean equals(final Object obj) {
557 if (!super.equals(obj)) {
561 final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
563 // TODO: benchmark to see if just calling equals() on the two maps is not faster
564 if (keyValues == otherKeyValues) {
567 if (keyValues.size() != otherKeyValues.size()) {
571 for (Entry<QName, Object> entry : keyValues.entrySet()) {
572 if (!otherKeyValues.containsKey(entry.getKey())
573 || !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
583 public String toString() {
584 return super.toString() + '[' + keyValues + ']';
588 public String toRelativeString(final PathArgument previous) {
589 return super.toRelativeString(previous) + '[' + keyValues + ']';
594 * Simple path argument identifying a {@link LeafSetEntryNode} leaf
597 public static final class NodeWithValue extends AbstractPathArgument {
598 private static final long serialVersionUID = -3637456085341738431L;
600 private final Object value;
602 public NodeWithValue(final QName node, final Object value) {
607 public Object getValue() {
612 protected int hashCodeImpl() {
613 final int prime = 31;
614 int result = super.hashCodeImpl();
615 result = prime * result + ((value == null) ? 0 : YangInstanceIdentifier.hashCode(value));
620 public boolean equals(final Object obj) {
621 if (!super.equals(obj)) {
624 final NodeWithValue other = (NodeWithValue) obj;
625 return Objects.deepEquals(value, other.value);
629 public String toString() {
630 return super.toString() + '[' + value + ']';
634 public String toRelativeString(final PathArgument previous) {
635 return super.toRelativeString(previous) + '[' + value + ']';
640 * Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
641 * particular subtree.
643 * Augmentation is uniquely identified by set of all possible child nodes.
645 * to identify instance of augmentation,
646 * since RFC6020 states that <code>augment</code> that augment
647 * statement must not add multiple nodes from same namespace
648 * / module to the target node.
651 * @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
653 public static final class AugmentationIdentifier implements PathArgument {
654 private static final long serialVersionUID = -8122335594681936939L;
655 private final ImmutableSet<QName> childNames;
658 public QName getNodeType() {
659 // This should rather throw exception than return always null
660 throw new UnsupportedOperationException("Augmentation node has no QName");
665 * Construct new augmentation identifier using supplied set of possible
669 * Set of possible child nodes.
671 public AugmentationIdentifier(final Set<QName> childNames) {
672 this.childNames = ImmutableSet.copyOf(childNames);
676 * Returns set of all possible child nodes
678 * @return set of all possible child nodes.
680 public Set<QName> getPossibleChildNames() {
685 public String toString() {
686 final StringBuilder sb = new StringBuilder("AugmentationIdentifier{");
687 sb.append("childNames=").append(childNames).append('}');
688 return sb.toString();
692 public String toRelativeString(final PathArgument previous) {
697 public boolean equals(final Object o) {
701 if (!(o instanceof AugmentationIdentifier)) {
705 AugmentationIdentifier that = (AugmentationIdentifier) o;
706 return childNames.equals(that.childNames);
710 public int hashCode() {
711 return childNames.hashCode();
715 public int compareTo(final PathArgument o) {
716 if (!(o instanceof AugmentationIdentifier)) {
719 AugmentationIdentifier other = (AugmentationIdentifier) o;
720 Set<QName> otherChildNames = other.getPossibleChildNames();
721 int thisSize = childNames.size();
722 int otherSize = otherChildNames.size();
723 if (thisSize == otherSize) {
724 Iterator<QName> otherIterator = otherChildNames.iterator();
725 for (QName name : childNames) {
726 int c = name.compareTo(otherIterator.next());
732 } else if (thisSize < otherSize) {