*/
package org.opendaylight.yangtools.yang.model.api;
+import com.google.common.base.MoreObjects;
+import com.google.common.base.MoreObjects.ToStringHelper;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.UnmodifiableIterator;
+import java.util.Arrays;
+import java.util.Iterator;
import java.util.List;
-
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import org.opendaylight.yangtools.concepts.Immutable;
import org.opendaylight.yangtools.yang.common.QName;
-import com.google.common.collect.ImmutableList;
-
/**
- *
* Represents unique path to the every node inside the module.
- *
*/
-public class SchemaPath {
+public abstract class SchemaPath implements Immutable {
+
+ /**
+ * An absolute SchemaPath.
+ */
+ private static final class AbsoluteSchemaPath extends SchemaPath {
+ private AbsoluteSchemaPath(final SchemaPath parent, final QName qname) {
+ super(parent, qname);
+ }
+
+ @Override
+ public boolean isAbsolute() {
+ return true;
+ }
+
+ @Override
+ protected SchemaPath createInstance(final SchemaPath parent, final QName qname) {
+ return new AbsoluteSchemaPath(parent, qname);
+ }
+ }
+
+ /**
+ * A relative SchemaPath.
+ */
+ private static final class RelativeSchemaPath extends SchemaPath {
+ private RelativeSchemaPath(final SchemaPath parent, final QName qname) {
+ super(parent, qname);
+ }
+
+ @Override
+ public boolean isAbsolute() {
+ return false;
+ }
+
+ @Override
+ protected SchemaPath createInstance(final SchemaPath parent, final QName qname) {
+ return new RelativeSchemaPath(parent, qname);
+ }
+ }
+
+ @SuppressWarnings("rawtypes")
+ private static final AtomicReferenceFieldUpdater<SchemaPath, ImmutableList> LEGACYPATH_UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(SchemaPath.class, ImmutableList.class, "legacyPath");
+
+ /**
+ * Shared instance of the conceptual root schema node.
+ */
+ public static final SchemaPath ROOT = new AbsoluteSchemaPath(null, null);
+
+ /**
+ * Shared instance of the "same" relative schema node.
+ */
+ public static final SchemaPath SAME = new RelativeSchemaPath(null, null);
+
/**
- * List of QName instances which represents complete path to the node.
+ * Parent path.
*/
- private final List<QName> path;
+ private final SchemaPath parent;
/**
- * Boolean value which represents type of schema path (relative or
- * absolute).
+ * This component.
*/
- private final Boolean absolute;
+ private final QName qname;
+
+ /**
+ * Cached hash code. We can use this since we are immutable.
+ */
+ private final int hash;
+
+ /**
+ * Cached legacy path, filled-in when {@link #getPath()} or {@link #getPathTowardsRoot()}
+ * is invoked.
+ */
+ private volatile ImmutableList<QName> legacyPath;
+
+ protected SchemaPath(final SchemaPath parent, final QName qname) {
+ this.parent = parent;
+ this.qname = qname;
+
+ int h = Objects.hashCode(parent);
+ if (qname != null) {
+ h = h * 31 + qname.hashCode();
+ }
+
+ hash = h;
+ }
+
+ private ImmutableList<QName> getLegacyPath() {
+ ImmutableList<QName> ret = legacyPath;
+ if (ret == null) {
+ ret = ImmutableList.copyOf(getPathTowardsRoot()).reverse();
+ LEGACYPATH_UPDATER.lazySet(this, ret);
+ }
+
+ return ret;
+ }
+
+ /**
+ * Returns the complete path to schema node.
+ *
+ * @return list of <code>QName</code> instances which represents complete
+ * path to schema node
+ *
+ * @deprecated Use {@link #getPathFromRoot()} instead.
+ */
+ @Deprecated
+ public List<QName> getPath() {
+ return getLegacyPath();
+ }
/**
* Constructs new instance of this class with the concrete path.
* @param absolute
* boolean value which specifies if the path is absolute or
* relative
+ *
+ * @return A SchemaPath instance.
*/
- public SchemaPath(final List<QName> path, final boolean absolute) {
- this.path = ImmutableList.copyOf(path);
- this.absolute = absolute;
+ public static SchemaPath create(final Iterable<QName> path, final boolean absolute) {
+ final SchemaPath parent = absolute ? ROOT : SAME;
+ return parent.createChild(path);
}
/**
- * Returns the complete path to schema node.
+ * Constructs new instance of this class with the concrete path.
*
- * @return list of <code>QName</code> instances which represents complete
- * path to schema node
+ * @param absolute
+ * boolean value which specifies if the path is absolute or
+ * relative
+ * @param path
+ * one or more QName instances which specifies exact path to the
+ * module node
+ *
+ * @return A SchemaPath instance.
*/
- public List<QName> getPath() {
- return path;
+ public static SchemaPath create(final boolean absolute, final QName... path) {
+ return create(Arrays.asList(path), absolute);
+ }
+
+ /**
+ * Create a new instance.
+ *
+ * @param parent Parent SchemaPath
+ * @param qname next path element
+ * @return A new SchemaPath instance
+ */
+ protected abstract SchemaPath createInstance(SchemaPath parent, QName qname);
+
+ /**
+ * Create a child path based on concatenation of this path and a relative path.
+ *
+ * @param relative Relative path
+ * @return A new child path
+ */
+ public SchemaPath createChild(final Iterable<QName> relative) {
+ if (Iterables.isEmpty(relative)) {
+ return this;
+ }
+
+ SchemaPath parentPath = this;
+ for (QName qname : relative) {
+ parentPath = parentPath.createInstance(parentPath, qname);
+ }
+
+ return parentPath;
+ }
+
+ /**
+ * Create a child path based on concatenation of this path and a relative path.
+ *
+ * @param relative Relative SchemaPath
+ * @return A new child path
+ */
+ public SchemaPath createChild(final SchemaPath relative) {
+ Preconditions.checkArgument(!relative.isAbsolute(), "Child creation requires relative path");
+
+ SchemaPath parentPath = this;
+ for (QName qname : relative.getPathFromRoot()) {
+ parentPath = parentPath.createInstance(parentPath, qname);
+ }
+
+ return parentPath;
+ }
+
+ /**
+ * Create a child path based on concatenation of this path and additional
+ * path elements.
+ *
+ * @param elements Relative SchemaPath elements
+ * @return A new child path
+ */
+ public SchemaPath createChild(final QName... elements) {
+ return createChild(Arrays.asList(elements));
+ }
+
+ /**
+ * Returns the list of nodes which need to be traversed to get from the
+ * starting point (root for absolute SchemaPaths) to the node represented
+ * by this object.
+ *
+ * @return list of <code>qname</code> instances which represents
+ * path from the root to the schema node.
+ */
+ public Iterable<QName> getPathFromRoot() {
+ return getLegacyPath();
+ }
+
+ /**
+ * Returns the list of nodes which need to be traversed to get from this
+ * node to the starting point (root for absolute SchemaPaths).
+ *
+ * @return list of <code>qname</code> instances which represents
+ * path from the schema node towards the root.
+ */
+ public Iterable<QName> getPathTowardsRoot() {
+ return new Iterable<QName>() {
+ @Override
+ public Iterator<QName> iterator() {
+ return new UnmodifiableIterator<QName>() {
+ private SchemaPath current = SchemaPath.this;
+
+ @Override
+ public boolean hasNext() {
+ return current.parent != null;
+ }
+
+ @Override
+ public QName next() {
+ if (current.parent != null) {
+ final QName ret = current.qname;
+ current = current.parent;
+ return ret;
+ } else {
+ throw new NoSuchElementException("No more elements available");
+ }
+ }
+ };
+ }
+ };
+ }
+
+ /**
+ * Returns the immediate parent SchemaPath.
+ *
+ * @return Parent path, null if this SchemaPath is already toplevel.
+ */
+ public SchemaPath getParent() {
+ return parent;
+ }
+
+ /**
+ * Get the last component of this path.
+ *
+ * @return The last component of this path.
+ */
+ public final QName getLastComponent() {
+ return qname;
}
/**
* @return boolean value which is <code>true</code> if schema path is
* absolute.
*/
- public boolean isAbsolute() {
- return absolute;
- }
+ public abstract boolean isAbsolute();
@Override
- public int hashCode() {
- final int prime = 31;
- int result = 1;
- result = prime * result + absolute.hashCode();
- result = prime * result + ((path == null) ? 0 : path.hashCode());
- return result;
+ public final int hashCode() {
+ return hash;
}
@Override
if (getClass() != obj.getClass()) {
return false;
}
- SchemaPath other = (SchemaPath) obj;
- if (absolute != other.absolute) {
- return false;
- }
- if (path == null) {
- if (other.path != null) {
+ final SchemaPath other = (SchemaPath) obj;
+
+ if (qname != null) {
+ if (!qname.equals(other.qname)) {
+ return false;
+ }
+ } else {
+ if (other.qname != null) {
return false;
}
- } else if (!path.equals(other.path)) {
- return false;
}
- return true;
+
+ if (parent == null) {
+ return other.parent == null;
+ }
+ return parent.equals(other.parent);
}
@Override
- public String toString() {
- StringBuilder builder = new StringBuilder();
- builder.append("SchemaPath [path=");
- builder.append(path);
- builder.append(", absolute=");
- builder.append(absolute);
- builder.append("]");
- return builder.toString();
+ public final String toString() {
+ return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
+ }
+
+ protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
+ return toStringHelper.add("path", getPathFromRoot());
}
}
Code Review / yangtools.git / blobdiff