/*
* 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.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
+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 com.google.common.collect.Lists;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.ObjectStreamException;
import java.io.Serializable;
import java.lang.reflect.Array;
-import java.lang.reflect.Field;
-import java.util.ArrayList;
import java.util.Arrays;
-import java.util.Collections;
+import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
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;
* 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>
+ * </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>
+ * </p>
* <ul>
* <li>{@link NodeIdentifier} - Identifier of node, which has cardinality
* <code>0..1</code> in particular subtree in data tree.</li>
*
* @see <a href="http://tools.ietf.org/html/rfc6020#section-9.13">RFC6020</a>
*/
-public final class YangInstanceIdentifier implements Path<YangInstanceIdentifier>, Immutable, Serializable {
- @SuppressWarnings("rawtypes")
- private static final AtomicReferenceFieldUpdater<YangInstanceIdentifier, ImmutableList> LEGACYPATH_UPDATER =
- AtomicReferenceFieldUpdater.newUpdater(YangInstanceIdentifier.class, ImmutableList.class, "legacyPath");
+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 YangInstanceIdentifier EMPTY = trustedCreate(Collections.<PathArgument>emptyList());
- private static final Field PATHARGUMENTS_FIELD;
+ private static final long serialVersionUID = 4L;
- private static final long serialVersionUID = 3L;
- private transient final Iterable<PathArgument> pathArguments;
private final int hash;
-
- private volatile ImmutableList<PathArgument> legacyPath = null;
private transient volatile String toStringCache = null;
- static {
- final Field f;
- try {
- f = YangInstanceIdentifier.class.getDeclaredField("pathArguments");
- } catch (NoSuchFieldException | SecurityException e) {
- throw new ExceptionInInitializerError(e);
- }
- f.setAccessible(true);
-
- PATHARGUMENTS_FIELD = f;
+ // Package-private to prevent outside subclassing
+ YangInstanceIdentifier(final int hash) {
+ this.hash = hash;
}
- private final ImmutableList<PathArgument> getLegacyPath() {
- // Temporary variable saves a volatile read
- ImmutableList<PathArgument> ret = legacyPath;
- if (ret == null) {
- // We could have used a synchronized block, but the window is quite
- // small and worst that can happen is duplicate object construction.
- ret = ImmutableList.copyOf(pathArguments);
- LEGACYPATH_UPDATER.lazySet(this, ret);
- }
+ @Nonnull abstract YangInstanceIdentifier createRelativeIdentifier(int skipFromRoot);
+ @Nonnull abstract Collection<PathArgument> tryPathArguments();
+ @Nonnull abstract Collection<PathArgument> tryReversePathArguments();
- return ret;
- }
+ /**
+ * 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();
/**
- * Returns a list of path arguments.
+ * Return an optimized version of this identifier, useful when the identifier
+ * will be used very frequently.
*
- * @deprecated Use {@link #getPathArguments()} instead.
- * @return Immutable list of path arguments.
+ * @return A optimized equivalent instance.
*/
- @Deprecated
- public List<PathArgument> getPath() {
- return getLegacyPath();
- }
+ @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 Iterable<PathArgument> getPathArguments() {
- return pathArguments;
- }
+ public abstract List<PathArgument> getPathArguments();
/**
* Returns an iterable of path arguments in reverse order. This is useful
*
* @return Immutable iterable of path arguments in reverse order.
*/
- public Iterable<PathArgument> getReversePathArguments() {
- return getLegacyPath().reverse();
- }
+ public abstract List<PathArgument> getReversePathArguments();
/**
* Returns the last PathArgument. This is equivalent of iterating
*
* @return The last past argument, or null if there are no PathArguments.
*/
- public PathArgument getLastPathArgument() {
- return Iterables.getFirst(getReversePathArguments(), null);
- }
+ public abstract PathArgument getLastPathArgument();
- private YangInstanceIdentifier(final Iterable<PathArgument> path, final int hash) {
- this.pathArguments = Preconditions.checkNotNull(path, "path must not be null.");
- this.hash = hash;
- }
+ public static YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
+ if (Iterables.isEmpty(path)) {
+ return EMPTY;
+ }
- private static final YangInstanceIdentifier trustedCreate(final Iterable<PathArgument> path) {
final HashCodeBuilder<PathArgument> hash = new HashCodeBuilder<>();
for (PathArgument a : path) {
hash.addArgument(a);
}
- return new YangInstanceIdentifier(path, hash.build());
- }
-
- public static final YangInstanceIdentifier create(final Iterable<? extends PathArgument> path) {
- if (Iterables.isEmpty(path)) {
- return EMPTY;
- }
-
- return trustedCreate(ImmutableList.copyOf(path));
+ return FixedYangInstanceIdentifier.create(path, hash.build());
}
- public static final YangInstanceIdentifier create(final PathArgument... path) {
+ 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 int hashCode() {
+ public final int hashCode() {
/*
* The caching is safe, since the object contract requires
* immutability of the object and all objects referenced from this
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 == null) {
- return false;
- }
- if (getClass() != obj.getClass()) {
+ if (!(obj instanceof YangInstanceIdentifier)) {
return false;
}
YangInstanceIdentifier other = (YangInstanceIdentifier) obj;
if (this.hashCode() != obj.hashCode()) {
return false;
}
- return Iterables.elementsEqual(pathArguments, other.pathArguments);
+
+ return pathArgumentsEqual(other);
}
/**
* @param name QName of {@link NodeIdentifier}
* @return Instance Identifier with additional path argument added to the end.
*/
- public YangInstanceIdentifier node(final QName name) {
+ public final YangInstanceIdentifier node(final QName name) {
return node(new NodeIdentifier(name));
}
* @param arg Path argument which should be added to the end
* @return Instance Identifier with additional path argument added to the end.
*/
- public YangInstanceIdentifier node(final PathArgument arg) {
- return new YangInstanceIdentifier(Iterables.concat(pathArguments, Collections.singleton(arg)), HashCodeBuilder.nextHashCode(hash, arg));
+ public final YangInstanceIdentifier node(final PathArgument arg) {
+ return new StackedYangInstanceIdentifier(this, arg, HashCodeBuilder.nextHashCode(hash, arg));
}
/**
* the specified parent is not in fact an ancestor of this object.
*/
public Optional<YangInstanceIdentifier> relativeTo(final YangInstanceIdentifier ancestor) {
- final Iterator<?> lit = pathArguments.iterator();
- final Iterator<?> oit = ancestor.pathArguments.iterator();
+ final Iterator<?> lit = getPathArguments().iterator();
+ final Iterator<?> oit = ancestor.getPathArguments().iterator();
int common = 0;
while (oit.hasNext()) {
if (!lit.hasNext()) {
return Optional.of(EMPTY);
}
- return Optional.of(trustedCreate(Iterables.skip(pathArguments, common)));
+
+ return Optional.of(createRelativeIdentifier(common));
+ }
+
+ @Override
+ public final boolean contains(final YangInstanceIdentifier other) {
+ 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) {
return 0;
}
- if (value.getClass().equals(byte[].class)) {
+ if (byte[].class.equals(value.getClass())) {
return Arrays.hashCode((byte[]) 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
}
/**
- *
* Returns new builder for InstanceIdentifier with empty path arguments.
*
* @return new builder for InstanceIdentifier with empty path arguments.
*/
- static public InstanceIdentifierBuilder builder() {
- return new BuilderImpl();
+ public static InstanceIdentifierBuilder builder() {
+ return new YangInstanceIdentifierBuilder();
}
/**
*
* Returns new builder for InstanceIdentifier with path arguments copied from original instance identifier.
*
- * @param origin Instace Identifier from which path arguments are copied.
+ * @param origin InstanceIdentifier from which path arguments are copied.
* @return new builder for InstanceIdentifier with path arguments copied from original instance identifier.
*/
- static public InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
- return new BuilderImpl(origin.getPathArguments(), origin.hashCode());
+ public static InstanceIdentifierBuilder builder(final YangInstanceIdentifier origin) {
+ return new YangInstanceIdentifierBuilder(origin.getPathArguments(), origin.hashCode());
}
/**
}
private static abstract class AbstractPathArgument implements PathArgument {
- private static final AtomicReferenceFieldUpdater<AbstractPathArgument, Integer> HASH_UPDATER =
- AtomicReferenceFieldUpdater.newUpdater(AbstractPathArgument.class, Integer.class, "hash");
private static final long serialVersionUID = -4546547994250849340L;
private final QName nodeType;
- private volatile transient Integer hash = null;
+ private transient int hashValue;
+ private transient volatile boolean hashGuard = false;
protected AbstractPathArgument(final QName nodeType) {
this.nodeType = Preconditions.checkNotNull(nodeType);
@Override
public final int hashCode() {
- Integer ret = hash;
- if (ret == null) {
- ret = hashCodeImpl();
- HASH_UPDATER.lazySet(this, ret);
+ if (!hashGuard) {
+ hashValue = hashCodeImpl();
+ hashGuard = true;
}
- return ret;
+ return hashValue;
}
@Override
}
}
- /**
- * Fluent Builder of Instance Identifier instances
- */
- public interface InstanceIdentifierBuilder extends Builder<YangInstanceIdentifier> {
- /**
- * 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();
-
- /*
- * @deprecated use #build()
- */
- @Deprecated
- YangInstanceIdentifier toInstance();
- }
-
/**
* 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(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);
+ }
}
/**
public NodeIdentifierWithPredicates(final QName node, final Map<QName, Object> keyValues) {
super(node);
- this.keyValues = ImmutableMap.copyOf(keyValues);
+ // 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) {
- this(node, ImmutableMap.of(key, value));
+ super(node);
+ this.keyValues = SharedSingletonMap.unorderedOf(key, value);
}
public Map<QName, Object> getKeyValues() {
}
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;
}
}
}
- private static class BuilderImpl implements InstanceIdentifierBuilder {
- private final HashCodeBuilder<PathArgument> hash;
- private final List<PathArgument> path;
-
- public BuilderImpl() {
- this.hash = new HashCodeBuilder<>();
- this.path = new ArrayList<>();
- }
-
- public BuilderImpl(final Iterable<PathArgument> prefix, final int hash) {
- this.path = Lists.newArrayList(prefix);
- this.hash = new HashCodeBuilder<>(hash);
- }
-
- @Override
- public InstanceIdentifierBuilder node(final QName nodeType) {
- final PathArgument arg = new NodeIdentifier(nodeType);
- path.add(arg);
- hash.addArgument(arg);
- return this;
- }
-
- @Override
- public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final QName key, final Object value) {
- final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, key, value);
- path.add(arg);
- hash.addArgument(arg);
- return this;
- }
-
- @Override
- public InstanceIdentifierBuilder nodeWithKey(final QName nodeType, final Map<QName, Object> keyValues) {
- final PathArgument arg = new NodeIdentifierWithPredicates(nodeType, keyValues);
- path.add(arg);
- hash.addArgument(arg);
- return this;
- }
-
- @Override
- @Deprecated
- public YangInstanceIdentifier toInstance() {
- return build();
- }
-
- @Override
- public YangInstanceIdentifier build() {
- return new YangInstanceIdentifier(ImmutableList.copyOf(path), hash.build());
- }
- }
-
- @Override
- public boolean contains(final YangInstanceIdentifier other) {
- Preconditions.checkArgument(other != null, "other should not be null");
-
- final Iterator<?> lit = pathArguments.iterator();
- final Iterator<?> oit = other.pathArguments.iterator();
-
- while (lit.hasNext()) {
- if (!oit.hasNext()) {
- return false;
- }
-
- if (!lit.next().equals(oit.next())) {
- return false;
- }
- }
-
- return true;
- }
-
- @Override
- public 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.
+ /**
+ * 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
*/
- 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;
- }
+ InstanceIdentifierBuilder node(PathArgument arg);
- private void readObject(final ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
- inputStream.defaultReadObject();
+ /**
+ * 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);
- try {
- PATHARGUMENTS_FIELD.set(this, legacyPath);
- } catch (IllegalArgumentException | IllegalAccessException e) {
- throw new IOException(e);
- }
- }
+ /**
+ * 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);
- private Object readResolve() throws ObjectStreamException {
- return legacyPath.isEmpty() ? EMPTY : this;
- }
+ /**
+ * 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);
- private void writeObject(final ObjectOutputStream outputStream) throws IOException {
- /*
- * This may look strange, but what we are doing here is side-stepping the fact
- * that pathArguments is not generally serializable. We are forcing instantiation
- * of the legacy path, which is an ImmutableList (thus Serializable) and write
- * it out. The read path does the opposite -- it reads the legacyPath and then
- * uses invocation API to set the field.
+ /**
+ *
+ * Builds an {@link YangInstanceIdentifier} with path arguments from this builder
+ *
+ * @return {@link YangInstanceIdentifier}
*/
- getLegacyPath();
- outputStream.defaultWriteObject();
+ @Override
+ YangInstanceIdentifier build();
}
}