/*
* ModeShape (http://www.modeshape.org)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.modeshape.jcr.value.basic;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.modeshape.common.annotation.Immutable;
import org.modeshape.common.collection.SingleIterator;
import org.modeshape.common.text.Inflector;
import org.modeshape.common.text.TextEncoder;
import org.modeshape.common.util.CheckArg;
import org.modeshape.jcr.GraphI18n;
import org.modeshape.jcr.value.InvalidPathException;
import org.modeshape.jcr.value.Name;
import org.modeshape.jcr.value.NamespaceRegistry;
import org.modeshape.jcr.value.Path;
/**
* Optimized implementation of {@link Path} that serves as the root path.
*/
@Immutable
public class RootPath extends AbstractPath {
/**
* The serializable version. Version {@value}
*/
private static final long serialVersionUID = 1L;
public static final Path INSTANCE = new RootPath();
private static final Path.Segment[] EMPTY_SEGMENT_ARRAY = new Path.Segment[] {};
private static final List<Path.Segment> EMPTY_SEGMENT_LIST = Collections.emptyList();
private RootPath() {
}
@Override
public Path getAncestor( int degree ) {
CheckArg.isNonNegative(degree, "degree");
if (degree == 0) {
return this;
}
String msg = GraphI18n.pathAncestorDegreeIsInvalid.text(this.getString(), Inflector.getInstance().ordinalize(degree));
throw new InvalidPathException(msg);
}
@Override
protected Iterator<Segment> getSegmentsOfParent() {
return EMPTY_PATH_ITERATOR;
}
@Override
public Path getCanonicalPath() {
return this;
}
@Override
public Path getCommonAncestor( Path that ) {
CheckArg.isNotNull(that, "that");
return this;
}
@Override
public Segment getLastSegment() {
return null;
}
@Override
public boolean endsWith( Name nameOfLastSegment ) {
return false;
}
@Override
public boolean endsWith( Name nameOfLastSegment,
int snsIndex ) {
return false;
}
@Override
public Path getNormalizedPath() {
return this;
}
@Override
public Path relativeToRoot() {
return BasicPath.SELF_PATH;
}
@Override
public Path resolve( Path relativePath ) {
CheckArg.isNotNull(relativePath, "relative path");
if (relativePath.isAbsolute()) {
String msg = GraphI18n.pathIsNotRelative.text(relativePath);
throw new InvalidPathException(msg);
}
// Make an absolute path out of the supplied relative path ...
return new BasicPath(relativePath.getSegmentsList(), true).getNormalizedPath();
}
@Override
public Path getParent() {
return null;
}
@Override
public Segment getSegment( int index ) {
CheckArg.isNonNegative(index, "index");
EMPTY_SEGMENT_LIST.get(index); // throws IndexOutOfBoundsException
return null;
}
@Override
public Segment[] getSegmentsArray() {
// Can return the same array every time, since it's empty ...
return EMPTY_SEGMENT_ARRAY;
}
@Override
public List<Segment> getSegmentsList() {
return EMPTY_SEGMENT_LIST;
}
@Override
public String getString() {
return Path.DELIMITER_STR;
}
@Override
public String getString( TextEncoder encoder ) {
return Path.DELIMITER_STR;
}
@Override
public String getString( NamespaceRegistry namespaceRegistry ) {
CheckArg.isNotNull(namespaceRegistry, "namespaceRegistry");
return Path.DELIMITER_STR;
}
@Override
public String getString( NamespaceRegistry namespaceRegistry,
TextEncoder encoder ) {
CheckArg.isNotNull(namespaceRegistry, "namespaceRegistry");
return Path.DELIMITER_STR;
}
@Override
public String getString( NamespaceRegistry namespaceRegistry,
TextEncoder encoder,
TextEncoder delimiterEncoder ) {
return (delimiterEncoder == null) ? DELIMITER_STR : delimiterEncoder.encode(DELIMITER_STR);
}
@Override
public boolean hasSameAncestor( Path that ) {
CheckArg.isNotNull(that, "that");
return true;
}
@Override
public boolean isAbsolute() {
return true;
}
@Override
public boolean isAncestorOf( Path descendant ) {
CheckArg.isNotNull(descendant, "descendant");
return !descendant.isRoot();
}
@Override
public boolean isAtOrAbove( Path other ) {
CheckArg.isNotNull(other, "other");
return true;
}
@Override
public boolean isAtOrBelow( Path other ) {
CheckArg.isNotNull(other, "other");
return other.isRoot();
}
@Override
public boolean isDescendantOf( Path ancestor ) {
CheckArg.isNotNull(ancestor, "ancestor");
return false;
}
@Override
public boolean isNormalized() {
return true;
}
@Override
public boolean isRoot() {
return true;
}
@Override
public boolean isSameAs( Path other ) {
CheckArg.isNotNull(other, "other");
return other.isRoot();
}
@Override
public Iterator<Segment> iterator() {
return EMPTY_SEGMENT_LIST.iterator();
}
@Override
public Iterator<Path> pathsFromRoot() {
return new SingleIterator<Path>(this);
}
@Override
public int size() {
return 0;
}
@Override
public Path subpath( int beginIndex ) {
CheckArg.isNonNegative(beginIndex, "beginIndex");
if (beginIndex == 0) return this;
EMPTY_SEGMENT_LIST.get(1); // throws IndexOutOfBoundsException
return null;
}
@Override
public Path subpath( int beginIndex,
int endIndex ) {
CheckArg.isNonNegative(beginIndex, "beginIndex");
CheckArg.isNonNegative(endIndex, "endIndex");
if (endIndex >= 1) {
EMPTY_SEGMENT_LIST.get(endIndex); // throws IndexOutOfBoundsException
}
return this;
}
@Override
public int compareTo( Path other ) {
return other.isRoot() ? 0 : -1;
}
@Override
public boolean equals( Object obj ) {
if (obj == this) return true;
if (obj instanceof Path) {
Path that = (Path)obj;
return that.isRoot();
}
return false;
}
@Override
public int hashCode() {
return 1;
}
}