org.apache.hadoop.net.NodeBase Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hadoop.net;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/** A base class that implements interface Node
*
*/
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Unstable
public class NodeBase implements Node {
/** Path separator {@value} */
public final static char PATH_SEPARATOR = '/';
/** Path separator as a string {@value} */
public final static String PATH_SEPARATOR_STR = "/";
/** string representation of root {@value} */
public final static String ROOT = "";
protected String name; //host:port#
protected String location; //string representation of this node's location
protected int level; //which level of the tree the node resides
protected Node parent; //its parent
/** Default constructor */
public NodeBase() {
}
/** Construct a node from its path
* @param path
* a concatenation of this node's location, the path separator, and its name
*/
public NodeBase(String path) {
path = normalize(path);
int index = path.lastIndexOf(PATH_SEPARATOR);
if (index== -1) {
set(ROOT, path);
} else {
set(path.substring(index+1), path.substring(0, index));
}
}
/** Construct a node from its name and its location
* @param name this node's name (can be null, must not contain {@link #PATH_SEPARATOR})
* @param location this node's location
*/
public NodeBase(String name, String location) {
set(name, normalize(location));
}
/** Construct a node from its name and its location
* @param name this node's name (can be null, must not contain {@link #PATH_SEPARATOR})
* @param location this node's location
* @param parent this node's parent node
* @param level this node's level in the tree
*/
public NodeBase(String name, String location, Node parent, int level) {
set(name, normalize(location));
this.parent = parent;
this.level = level;
}
/**
* set this node's name and location
* @param name the (nullable) name -which cannot contain the {@link #PATH_SEPARATOR}
* @param location the location
*/
private void set(String name, String location) {
if (name != null && name.contains(PATH_SEPARATOR_STR))
throw new IllegalArgumentException(
"Network location name contains /: "+name);
this.name = (name==null)?"":name;
this.location = location;
}
/** @return this node's name */
@Override
public String getName() { return name; }
/** @return this node's network location */
@Override
public String getNetworkLocation() { return location; }
/** Set this node's network location
* @param location the location
*/
@Override
public void setNetworkLocation(String location) { this.location = location; }
/**
* Get the path of a node
* @param node a non-null node
* @return the path of a node
*/
public static String getPath(Node node) {
return node.getNetworkLocation() + PATH_SEPARATOR_STR + node.getName();
}
/**
* Get the path components of a node.
* @param node a non-null node
* @return the path of a node
*/
public static String[] getPathComponents(Node node) {
return getPath(node).split(PATH_SEPARATOR_STR);
}
@Override
public boolean equals(Object to) {
if (this == to) {
return true;
}
if (!(to instanceof NodeBase)) {
return false;
}
return getPath(this).equals(getPath((NodeBase)to));
}
@Override
public int hashCode() {
return getPath(this).hashCode();
}
/** @return this node's path as its string representation */
@Override
public String toString() {
return getPath(this);
}
/** Normalize a path by stripping off any trailing {@link #PATH_SEPARATOR}
* @param path path to normalize.
* @return the normalised path
* If pathis null or empty {@link #ROOT} is returned
* @throws IllegalArgumentException if the first character of a non empty path
* is not {@link #PATH_SEPARATOR}
*/
public static String normalize(String path) {
if (path == null) {
throw new IllegalArgumentException(
"Network Location is null ");
}
if (path.length() == 0) {
return ROOT;
}
if (path.charAt(0) != PATH_SEPARATOR) {
throw new IllegalArgumentException(
"Network Location path does not start with "
+PATH_SEPARATOR_STR+ ": "+path);
}
int len = path.length();
if (path.charAt(len-1) == PATH_SEPARATOR) {
return path.substring(0, len-1);
}
return path;
}
/** @return this node's parent */
@Override
public Node getParent() { return parent; }
/** Set this node's parent
* @param parent the parent
*/
@Override
public void setParent(Node parent) {
this.parent = parent;
}
/** @return this node's level in the tree.
* E.g. the root of a tree returns 0 and its children return 1
*/
@Override
public int getLevel() { return level; }
/** Set this node's level in the tree
* @param level the level
*/
@Override
public void setLevel(int level) {
this.level = level;
}
public static int locationToDepth(String location) {
String normalizedLocation = normalize(location);
int length = normalizedLocation.length();
int depth = 0;
for (int i = 0; i < length; i++) {
if (normalizedLocation.charAt(i) == PATH_SEPARATOR) {
depth++;
}
}
return depth;
}
}