/*
* Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.data.api;
import com.google.common.annotations.Beta;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import java.io.Serializable;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import org.opendaylight.yangtools.concepts.Builder;
import org.opendaylight.yangtools.concepts.Immutable;
import org.opendaylight.yangtools.concepts.Path;
import org.opendaylight.yangtools.util.HashCodeBuilder;
import org.opendaylight.yangtools.util.ImmutableOffsetMap;
import org.opendaylight.yangtools.util.SharedSingletonMap;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.common.QNameModule;
import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
/**
* Unique identifier of a particular node instance in the data tree.
*
* <p>
* Java representation of YANG Built-in type <code>instance-identifier</code>,
* which conceptually is XPath expression minimized to uniquely identify element
* in data tree which conforms to constraints maintained by YANG Model,
* effectively this makes Instance Identifier a path to element in data tree.
* </p>
* <p>
* Constraints put in YANG specification on instance-identifier allowed it to be
* effectively represented in Java and it's evaluation does not require
* full-blown XPath processor.
* </p>
* <h3>Path Arguments</h3>
* <p>
* Path to the node represented in instance identifier consists of
* {@link PathArgument} which carries necessary information to uniquely identify
* node on particular level in the subtree.
* </p>
* <ul>
* <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
* <code>0..1</code> in particular subtree in data tree.</li>
* <li>{@link NodeIdentifierWithPredicates} - Identifier of node (list item),
* which has cardinality <code>0..n</code>.</li>
* <li>{@link NodeWithValue} - Identifier of instance <code>leaf</code> node or
* <code>leaf-list</code> node.</li>
* <li>{@link AugmentationIdentifier} - Identifier of instance of
* <code>augmentation</code> node.</li>
* </ul>
*
*
* @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
*/
public abstract class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
/**
* An empty {@link YangInstanceIdentifier}. It corresponds to the path of the conceptual
* root of the YANG namespace.
*/
public static final YangInstanceIdentifier EMPTY = FixedYangInstanceIdentifier.EMPTY_INSTANCE;
private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, String> TOSTRINGCACHE_UPDATER =
AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, String.class, "toStringCache");
private static final long serialVersionUID = 4L;
private final int hash;
private transient volatile String toStringCache = null;
// Package-private to prevent outside subclassing
YangInstanceIdentifier(final int hash) {
this.hash = hash;
}
@Nonnull abstract YangInstanceIdentifier createRelativeIdentifier(int skipFromRoot);
@Nonnull abstract Collection<PathArgument> tryPathArguments();
@Nonnull abstract Collection<PathArgument> tryReversePathArguments();
/**
* Check if this instance identifier has empty path arguments, e.g. it is
* empty and corresponds to {@link #EMPTY}.
*
* @return True if this instance identifier is empty, false otherwise.
*/
public abstract boolean isEmpty();
/**
* Return an optimized version of this identifier, useful when the identifier
* will be used very frequently.
*
* @return A optimized equivalent instance.
*/
@Beta
public abstract YangInstanceIdentifier toOptimized();
/**
* Return the conceptual parent {@link YangInstanceIdentifier}, which has
* one item less in {@link #getPathArguments()}.
*
* @return Parent {@link YangInstanceIdentifier}, or null if this object is {@link #EMPTY}.
*/
@Nullable public abstract YangInstanceIdentifier getParent();
/**
* Return the ancestor {@link YangInstanceIdentifier} with a particular depth, e.g. number of path arguments.
*
* @param depth Ancestor depth
* @return Ancestor {@link YangInstanceIdentifier}
* @throws IllegalArgumentException if the specified depth is negative or is greater than the depth of this object.
*/
@Nonnull public abstract YangInstanceIdentifier getAncestor(int depth);
/**
* Returns an ordered iteration of path arguments.
*
* @return Immutable iteration of path arguments.
*/
public abstract List<PathArgument> getPathArguments();
/**
* Returns an iterable of path arguments in reverse order. This is useful
* when walking up a tree organized this way.
*
* @return Immutable iterable of path arguments in reverse order.
*/
public abstract List<PathArgument> getReversePathArguments();
/**
* Returns the last PathArgument. This is equivalent of iterating
* to the last element of the iterable returned by {@link #getPathArguments()}.
*
* @return The last past argument, or null if there are no PathArguments.
*/
public abstract PathArgument getLastPathArgument();
public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
if (Iterables.isEmpty(path)) {
return EMPTY;
}
final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
for (PathArgument a : path) {
hash.addArgument(a);
}
return FixedYangInstanceIdentifier.create(path, hash.build());
}
public static YangInstanceIdentifier create(final PathArgument... path) {
// We are forcing a copy, since we cannot trust the user
return create(Arrays.asList(path));
}
@Override
public final int hashCode() {
/*
* The caching is safe, since the object contract requires
* immutability of the object and all objects referenced from this
* object.
* Used lists, maps are immutable. Path Arguments (elements) are also
* immutable, since the PathArgument contract requires immutability.
*/
return hash;
}
boolean pathArgumentsEqual(final YangInstanceIdentifier other) {
return Iterables.elementsEqual(getPathArguments(), other.getPathArguments());
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof YangInstanceIdentifier)) {
return false;
}
YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
if (this.hashCode() != obj.hashCode()) {
return false;
}
return pathArgumentsEqual(other);
}
/**
* Constructs a new Instance Identifier with new {@link NodeIdentifier} added to the end of path arguments
*
* @param name QName of {@link NodeIdentifier}
* @return Instance Identifier with additional path argument added to the end.
*/
public final YangInstanceIdentifier node(final QName name) {
return node(new NodeIdentifier(name));
}
/**
*
* Constructs a new Instance Identifier with new {@link PathArgument} added to the end of path arguments
*
* @param arg Path argument which should be added to the end
* @return Instance Identifier with additional path argument added to the end.
*/
public final YangInstanceIdentifier node(final PathArgument arg) {
return new StackedYangInstanceIdentifier(this, arg, HashCodeBuilder.nextHashCode(hash, arg));
}
/**
* Get the relative path from an ancestor. This method attempts to perform
* the reverse of concatenating a base (ancestor) and a path.
*
* @param ancestor
* Ancestor against which the relative path should be calculated
* @return This object's relative path from parent, or Optional.absent() if
* the specified parent is not in fact an ancestor of this object.
*/
public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
if (this == ancestor) {
return Optional.of(EMPTY);
}
if (ancestor.isEmpty()) {
return Optional.of(this);
}
final Iterator<?> lit = getPathArguments().iterator();
final Iterator<?> oit = ancestor.getPathArguments().iterator();
int common = 0;
while (oit.hasNext()) {
// Ancestor is not really an ancestor
if (!lit.hasNext() || !lit.next().equals(oit.next())) {
return Optional.absent();
}
++common;
}
if (common == 0) {
return Optional.of(this);
}
if (!lit.hasNext()) {
return Optional.of(EMPTY);
}
return Optional.of(createRelativeIdentifier(common));
}
@Override
public final boolean contains(@Nonnull final YangInstanceIdentifier other) {
if (this == other) {
return true;
}
Preconditions.checkArgument(other != null, "other should not be null");
final Iterator<?> lit = getPathArguments().iterator();
final Iterator<?> oit = other.getPathArguments().iterator();
while (lit.hasNext()) {
if (!oit.hasNext()) {
return false;
}
if (!lit.next().equals(oit.next())) {
return false;
}
}
return true;
}
@Override
public final String toString() {
/*
* The toStringCache is safe, since the object contract requires
* immutability of the object and all objects referenced from this
* object.
* Used lists, maps are immutable. Path Arguments (elements) are also
* immutable, since the PathArgument contract requires immutability.
* The cache is thread-safe - if multiple computations occurs at the
* same time, cache will be overwritten with same result.
*/
String ret = toStringCache;
if (ret == null) {
final StringBuilder builder = new StringBuilder("/");
PathArgument prev = null;
for (PathArgument argument : getPathArguments()) {
if (prev != null) {
builder.append('/');
}
builder.append(argument.toRelativeString(prev));
prev = argument;
}
ret = builder.toString();
TOSTRINGCACHE_UPDATER.lazySet(this, ret);
}
return ret;
}
private static int hashCode(final Object value) {
if (value == null) {
return 0;
}
if (byte[].class.equals(value.getClass())) {
return Arrays.hashCode((byte[]) value);
}
if (value.getClass().isArray()) {
int hash = 0;
int length = Array.getLength(value);
for (int i = 0; i < length; i++) {
hash += Objects.hashCode(Array.get(value, i));
}
return hash;
}
return Objects.hashCode(value);
}
// Static factories & helpers
/**
* Returns a new InstanceIdentifier with only one path argument of type {@link NodeIdentifier} with supplied QName
*
* @param name QName of first node identifier
* @return Instance Identifier with only one path argument of type {@link NodeIdentifier}
*/
public static YangInstanceIdentifier of(final QName name) {
return create(new NodeIdentifier(name));
}
/**
* Returns new builder for InstanceIdentifier with empty path arguments.
*
* @return new builder for InstanceIdentifier with empty path arguments.
*/
public static InstanceIdentifierBuilder builder() {
return new YangInstanceIdentifierBuilder();
}
/**
*
* Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
*
* @param origin InstanceIdentifier from which path arguments are copied.
* @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
*/
public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
}
/**
* Path argument / component of InstanceIdentifier
*
* Path argument uniquely identifies node in data tree on particular
* level.
* <p>
* This interface itself is used as common parent for actual
* path arguments types and should not be implemented by user code.
* <p>
* Path arguments SHOULD contain only minimum of information
* required to uniquely identify node on particular subtree level.
*
* For actual path arguments types see:
* <ul>
* <li>{@link NodeIdentifier} - Identifier of container or leaf
* <li>{@link NodeIdentifierWithPredicates} - Identifier of list entries, which have key defined
* <li>{@link AugmentationIdentifier} - Identifier of augmentation
* <li>{@link NodeWithValue} - Identifier of leaf-list entry
* </ul>
*/
public interface PathArgument extends Comparable<PathArgument>, Immutable, Serializable {
/**
* If applicable returns unique QName of data node as defined in YANG
* Schema.
*
* This method may return null, if the corresponding schema node, does
* not have QName associated, such as in cases of augmentations.
*
* @return Node type
*/
QName getNodeType();
/**
* Return the string representation of this object for use in context
* provided by a previous object. This method can be implemented in
* terms of {@link #toString()}, but implementations are encourage to
* reuse any context already emitted by the previous object.
*
* @param previous Previous path argument
* @return String representation
*/
String toRelativeString(PathArgument previous);
}
private static abstract class AbstractPathArgument implements PathArgument {
private static final long serialVersionUID = -4546547994250849340L;
private final QName nodeType;
private transient int hashValue;
private transient volatile boolean hashGuard = false;
protected AbstractPathArgument(final QName nodeType) {
this.nodeType = Preconditions.checkNotNull(nodeType);
}
@Override
public final QName getNodeType() {
return nodeType;
}
@Override
public int compareTo(@Nonnull final PathArgument o) {
return nodeType.compareTo(o.getNodeType());
}
protected int hashCodeImpl() {
return 31 + getNodeType().hashCode();
}
@Override
public final int hashCode() {
if (!hashGuard) {
hashValue = hashCodeImpl();
hashGuard = true;
}
return hashValue;
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null || this.getClass() != obj.getClass()) {
return false;
}
return getNodeType().equals(((AbstractPathArgument)obj).getNodeType());
}
@Override
public String toString() {
return getNodeType().toString();
}
@Override
public String toRelativeString(final PathArgument previous) {
if (previous instanceof AbstractPathArgument) {
final QNameModule mod = previous.getNodeType().getModule();
if (getNodeType().getModule().equals(mod)) {
return getNodeType().getLocalName();
}
}
return getNodeType().toString();
}
}
/**
* Simple path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.ContainerNode} or
* {@link org.opendaylight.yangtools.yang.data.api.schema.LeafNode} leaf in particular subtree.
*/
public static final class NodeIdentifier extends AbstractPathArgument {
private static final long serialVersionUID = -2255888212390871347L;
private static final LoadingCache<QName, NodeIdentifier> CACHE = CacheBuilder.newBuilder().weakValues()
.build(new CacheLoader<QName, NodeIdentifier>() {
@Override
public NodeIdentifier load(@Nonnull final QName key) {
return new NodeIdentifier(key);
}
});
public NodeIdentifier(final QName node) {
super(node);
}
/**
* Return a NodeIdentifier for a particular QName. Unlike the constructor, this factory method uses a global
* instance cache, resulting in object reuse for equal inputs.
*
* @param node Node's QName
* @return A {@link NodeIdentifier}
*/
public static NodeIdentifier create(final QName node) {
return CACHE.getUnchecked(node);
}
}
/**
* Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode} leaf
* overall data tree.
*/
public static final class NodeIdentifierWithPredicates extends AbstractPathArgument {
private static final long serialVersionUID = -4787195606494761540L;
private final Map<QName, Object> keyValues;
public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
super(node);
// Retains ImmutableMap for empty maps. For larger sizes uses a shared key set.
this.keyValues = ImmutableOffsetMap.unorderedCopyOf(keyValues);
}
public NodeIdentifierWithPredicates(final QName node, final QName key, final Object value) {
super(node);
this.keyValues = SharedSingletonMap.unorderedOf(key, value);
}
public Map<QName, Object> getKeyValues() {
return keyValues;
}
@Override
protected int hashCodeImpl() {
final int prime = 31;
int result = super.hashCodeImpl();
result = prime * result;
for (Entry<QName, Object> entry : keyValues.entrySet()) {
result += Objects.hashCode(entry.getKey()) + YangInstanceIdentifier.hashCode(entry.getValue());
}
return result;
}
@Override
public boolean equals(final Object obj) {
if (!super.equals(obj)) {
return false;
}
final Map<QName, Object> otherKeyValues = ((NodeIdentifierWithPredicates) obj).keyValues;
// TODO: benchmark to see if just calling equals() on the two maps is not faster
if (keyValues == otherKeyValues) {
return true;
}
if (keyValues.size() != otherKeyValues.size()) {
return false;
}
for (Entry<QName, Object> entry : keyValues.entrySet()) {
if (!otherKeyValues.containsKey(entry.getKey())
|| !Objects.deepEquals(entry.getValue(), otherKeyValues.get(entry.getKey()))) {
return false;
}
}
return true;
}
@Override
public String toString() {
return super.toString() + '[' + keyValues + ']';
}
@Override
public String toRelativeString(final PathArgument previous) {
return super.toRelativeString(previous) + '[' + keyValues + ']';
}
}
/**
* Simple path argument identifying a {@link LeafSetEntryNode} leaf
* overall data tree.
*/
public static final class NodeWithValue<T> extends AbstractPathArgument {
private static final long serialVersionUID = -3637456085341738431L;
private final T value;
public NodeWithValue(final QName node, final T value) {
super(node);
this.value = value;
}
public T getValue() {
return value;
}
@Override
protected int hashCodeImpl() {
final int prime = 31;
int result = super.hashCodeImpl();
result = prime * result + YangInstanceIdentifier.hashCode(value);
return result;
}
@Override
public boolean equals(final Object obj) {
if (!super.equals(obj)) {
return false;
}
final NodeWithValue<?> other = (NodeWithValue<?>) obj;
return Objects.deepEquals(value, other.value);
}
@Override
public String toString() {
return super.toString() + '[' + value + ']';
}
@Override
public String toRelativeString(final PathArgument previous) {
return super.toRelativeString(previous) + '[' + value + ']';
}
}
/**
* Composite path argument identifying a {@link org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode} node in
* particular subtree.
*
* Augmentation is uniquely identified by set of all possible child nodes.
* This is possible
* to identify instance of augmentation,
* since RFC6020 states that <code>augment</code> that augment
* statement must not add multiple nodes from same namespace
* / module to the target node.
*
*
* @see <a href="http://tools.ietf.org/html/rfc6020#section-7.15">RFC6020</a>
*/
public static final class AugmentationIdentifier implements PathArgument {
private static final long serialVersionUID = -8122335594681936939L;
private final ImmutableSet<QName> childNames;
@Override
public QName getNodeType() {
// This should rather throw exception than return always null
throw new UnsupportedOperationException("Augmentation node has no QName");
}
/**
*
* Construct new augmentation identifier using supplied set of possible
* child nodes
*
* @param childNames
* Set of possible child nodes.
*/
public AugmentationIdentifier(final Set<QName> childNames) {
this.childNames = ImmutableSet.copyOf(childNames);
}
/**
* Returns set of all possible child nodes
*
* @return set of all possible child nodes.
*/
public Set<QName> getPossibleChildNames() {
return childNames;
}
@Override
public String toString() {
return "AugmentationIdentifier{" + "childNames=" + childNames + '}';
}
@Override
public String toRelativeString(final PathArgument previous) {
return toString();
}
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (!(o instanceof AugmentationIdentifier)) {
return false;
}
AugmentationIdentifier that = (AugmentationIdentifier) o;
return childNames.equals(that.childNames);
}
@Override
public int hashCode() {
return childNames.hashCode();
}
@Override
public int compareTo(@Nonnull final PathArgument o) {
if (!(o instanceof AugmentationIdentifier)) {
return -1;
}
AugmentationIdentifier other = (AugmentationIdentifier) o;
Set<QName> otherChildNames = other.getPossibleChildNames();
int thisSize = childNames.size();
int otherSize = otherChildNames.size();
if (thisSize == otherSize) {
Iterator<QName> otherIterator = otherChildNames.iterator();
for (QName name : childNames) {
int c = name.compareTo(otherIterator.next());
if (c != 0) {
return c;
}
}
return 0;
} else if (thisSize < otherSize) {
return 1;
} else {
return -1;
}
}
}
/**
* Fluent Builder of Instance Identifier instances
*/
public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
/**
* Adds a {@link PathArgument} to to path arguments of resulting instance identifier.
*
* @param arg A {@link PathArgument} to be added
* @return this builder
*/
InstanceIdentifierBuilder node(PathArgument arg);
/**
* Adds {@link NodeIdentifier} with supplied QName to path arguments of resulting instance identifier.
*
* @param nodeType QName of {@link NodeIdentifier} which will be added
* @return this builder
*/
InstanceIdentifierBuilder node(QName nodeType);
/**
* Adds {@link NodeIdentifierWithPredicates} with supplied QName and key values to path arguments of resulting instance identifier.
*
* @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
* @param keyValues Map of key components and their respective values for {@link NodeIdentifierWithPredicates}
* @return this builder
*/
InstanceIdentifierBuilder nodeWithKey(QName nodeType, Map<QName, Object> keyValues);
/**
* Adds {@link NodeIdentifierWithPredicates} with supplied QName and key, value.
*
* @param nodeType QName of {@link NodeIdentifierWithPredicates} which will be added
* @param key QName of key which will be added
* @param value value of key which will be added
* @return this builder
*/
InstanceIdentifierBuilder nodeWithKey(QName nodeType, QName key, Object value);
/**
*
* Builds an {@link YangInstanceIdentifier} with path arguments from this builder
*
* @return {@link YangInstanceIdentifier}
*/
@Override
YangInstanceIdentifier build();
}
}