| /** |
| * 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 seperator, 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(); |
| } |
| |
| /** @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 <i>path</i>is 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 || 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; |
| } |
| } |