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<FONT color="green">001</FONT>    /**<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<FONT color="green">003</FONT>     * or more contributor license agreements.  See the NOTICE file<a name="line.3"></a>
<FONT color="green">004</FONT>     * distributed with this work for additional information<a name="line.4"></a>
<FONT color="green">005</FONT>     * regarding copyright ownership.  The ASF licenses this file<a name="line.5"></a>
<FONT color="green">006</FONT>     * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<FONT color="green">007</FONT>     * "License"); you may not use this file except in compliance<a name="line.7"></a>
<FONT color="green">008</FONT>     * with the License.  You may obtain a copy of the License at<a name="line.8"></a>
<FONT color="green">009</FONT>     *<a name="line.9"></a>
<FONT color="green">010</FONT>     *     http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<FONT color="green">011</FONT>     *<a name="line.11"></a>
<FONT color="green">012</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<FONT color="green">013</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<FONT color="green">014</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<FONT color="green">015</FONT>     * See the License for the specific language governing permissions and<a name="line.15"></a>
<FONT color="green">016</FONT>     * limitations under the License.<a name="line.16"></a>
<FONT color="green">017</FONT>     */<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    package org.apache.hadoop.net;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    import org.apache.hadoop.classification.InterfaceAudience;<a name="line.21"></a>
<FONT color="green">022</FONT>    import org.apache.hadoop.classification.InterfaceStability;<a name="line.22"></a>
<FONT color="green">023</FONT>    import org.apache.hadoop.conf.Configurable;<a name="line.23"></a>
<FONT color="green">024</FONT>    import org.apache.hadoop.conf.Configuration;<a name="line.24"></a>
<FONT color="green">025</FONT>    import org.apache.hadoop.fs.CommonConfigurationKeys;<a name="line.25"></a>
<FONT color="green">026</FONT>    <a name="line.26"></a>
<FONT color="green">027</FONT>    import java.util.HashMap;<a name="line.27"></a>
<FONT color="green">028</FONT>    import java.util.HashSet;<a name="line.28"></a>
<FONT color="green">029</FONT>    import java.util.Map;<a name="line.29"></a>
<FONT color="green">030</FONT>    import java.util.Set;<a name="line.30"></a>
<FONT color="green">031</FONT>    <a name="line.31"></a>
<FONT color="green">032</FONT>    /**<a name="line.32"></a>
<FONT color="green">033</FONT>     * This is a base class for DNS to Switch mappings. &lt;p/&gt; It is not mandatory to<a name="line.33"></a>
<FONT color="green">034</FONT>     * derive {@link DNSToSwitchMapping} implementations from it, but it is strongly<a name="line.34"></a>
<FONT color="green">035</FONT>     * recommended, as it makes it easy for the Hadoop developers to add new methods<a name="line.35"></a>
<FONT color="green">036</FONT>     * to this base class that are automatically picked up by all implementations.<a name="line.36"></a>
<FONT color="green">037</FONT>     * &lt;p/&gt;<a name="line.37"></a>
<FONT color="green">038</FONT>     *<a name="line.38"></a>
<FONT color="green">039</FONT>     * This class does not extend the &lt;code&gt;Configured&lt;/code&gt;<a name="line.39"></a>
<FONT color="green">040</FONT>     * base class, and should not be changed to do so, as it causes problems<a name="line.40"></a>
<FONT color="green">041</FONT>     * for subclasses. The constructor of the &lt;code&gt;Configured&lt;/code&gt; calls<a name="line.41"></a>
<FONT color="green">042</FONT>     * the  {@link #setConf(Configuration)} method, which will call into the<a name="line.42"></a>
<FONT color="green">043</FONT>     * subclasses before they have been fully constructed.<a name="line.43"></a>
<FONT color="green">044</FONT>     *<a name="line.44"></a>
<FONT color="green">045</FONT>     */<a name="line.45"></a>
<FONT color="green">046</FONT>    @InterfaceAudience.Public<a name="line.46"></a>
<FONT color="green">047</FONT>    @InterfaceStability.Evolving<a name="line.47"></a>
<FONT color="green">048</FONT>    public abstract class AbstractDNSToSwitchMapping<a name="line.48"></a>
<FONT color="green">049</FONT>        implements DNSToSwitchMapping, Configurable {<a name="line.49"></a>
<FONT color="green">050</FONT>    <a name="line.50"></a>
<FONT color="green">051</FONT>      private Configuration conf;<a name="line.51"></a>
<FONT color="green">052</FONT>    <a name="line.52"></a>
<FONT color="green">053</FONT>      /**<a name="line.53"></a>
<FONT color="green">054</FONT>       * Create an unconfigured instance<a name="line.54"></a>
<FONT color="green">055</FONT>       */<a name="line.55"></a>
<FONT color="green">056</FONT>      protected AbstractDNSToSwitchMapping() {<a name="line.56"></a>
<FONT color="green">057</FONT>      }<a name="line.57"></a>
<FONT color="green">058</FONT>    <a name="line.58"></a>
<FONT color="green">059</FONT>      /**<a name="line.59"></a>
<FONT color="green">060</FONT>       * Create an instance, caching the configuration file.<a name="line.60"></a>
<FONT color="green">061</FONT>       * This constructor does not call {@link #setConf(Configuration)}; if<a name="line.61"></a>
<FONT color="green">062</FONT>       * a subclass extracts information in that method, it must call it explicitly.<a name="line.62"></a>
<FONT color="green">063</FONT>       * @param conf the configuration<a name="line.63"></a>
<FONT color="green">064</FONT>       */<a name="line.64"></a>
<FONT color="green">065</FONT>      protected AbstractDNSToSwitchMapping(Configuration conf) {<a name="line.65"></a>
<FONT color="green">066</FONT>        this.conf = conf;<a name="line.66"></a>
<FONT color="green">067</FONT>      }<a name="line.67"></a>
<FONT color="green">068</FONT>    <a name="line.68"></a>
<FONT color="green">069</FONT>      @Override<a name="line.69"></a>
<FONT color="green">070</FONT>      public Configuration getConf() {<a name="line.70"></a>
<FONT color="green">071</FONT>        return conf;<a name="line.71"></a>
<FONT color="green">072</FONT>      }<a name="line.72"></a>
<FONT color="green">073</FONT>    <a name="line.73"></a>
<FONT color="green">074</FONT>      @Override<a name="line.74"></a>
<FONT color="green">075</FONT>      public void setConf(Configuration conf) {<a name="line.75"></a>
<FONT color="green">076</FONT>        this.conf = conf;<a name="line.76"></a>
<FONT color="green">077</FONT>      }<a name="line.77"></a>
<FONT color="green">078</FONT>    <a name="line.78"></a>
<FONT color="green">079</FONT>      /**<a name="line.79"></a>
<FONT color="green">080</FONT>       * Predicate that indicates that the switch mapping is known to be<a name="line.80"></a>
<FONT color="green">081</FONT>       * single-switch. The base class returns false: it assumes all mappings are<a name="line.81"></a>
<FONT color="green">082</FONT>       * multi-rack. Subclasses may override this with methods that are more aware<a name="line.82"></a>
<FONT color="green">083</FONT>       * of their topologies.<a name="line.83"></a>
<FONT color="green">084</FONT>       *<a name="line.84"></a>
<FONT color="green">085</FONT>       * &lt;p/&gt;<a name="line.85"></a>
<FONT color="green">086</FONT>       *<a name="line.86"></a>
<FONT color="green">087</FONT>       * This method is used when parts of Hadoop need know whether to apply<a name="line.87"></a>
<FONT color="green">088</FONT>       * single rack vs multi-rack policies, such as during block placement.<a name="line.88"></a>
<FONT color="green">089</FONT>       * Such algorithms behave differently if they are on multi-switch systems.<a name="line.89"></a>
<FONT color="green">090</FONT>       * &lt;/p&gt;<a name="line.90"></a>
<FONT color="green">091</FONT>       *<a name="line.91"></a>
<FONT color="green">092</FONT>       * @return true if the mapping thinks that it is on a single switch<a name="line.92"></a>
<FONT color="green">093</FONT>       */<a name="line.93"></a>
<FONT color="green">094</FONT>      public boolean isSingleSwitch() {<a name="line.94"></a>
<FONT color="green">095</FONT>        return false;<a name="line.95"></a>
<FONT color="green">096</FONT>      }<a name="line.96"></a>
<FONT color="green">097</FONT>    <a name="line.97"></a>
<FONT color="green">098</FONT>      /**<a name="line.98"></a>
<FONT color="green">099</FONT>       * Get a copy of the map (for diagnostics)<a name="line.99"></a>
<FONT color="green">100</FONT>       * @return a clone of the map or null for none known<a name="line.100"></a>
<FONT color="green">101</FONT>       */<a name="line.101"></a>
<FONT color="green">102</FONT>      public Map&lt;String, String&gt; getSwitchMap() {<a name="line.102"></a>
<FONT color="green">103</FONT>        return null;<a name="line.103"></a>
<FONT color="green">104</FONT>      }<a name="line.104"></a>
<FONT color="green">105</FONT>    <a name="line.105"></a>
<FONT color="green">106</FONT>      /**<a name="line.106"></a>
<FONT color="green">107</FONT>       * Generate a string listing the switch mapping implementation,<a name="line.107"></a>
<FONT color="green">108</FONT>       * the mapping for every known node and the number of nodes and<a name="line.108"></a>
<FONT color="green">109</FONT>       * unique switches known about -each entry to a separate line.<a name="line.109"></a>
<FONT color="green">110</FONT>       * @return a string that can be presented to the ops team or used in<a name="line.110"></a>
<FONT color="green">111</FONT>       * debug messages.<a name="line.111"></a>
<FONT color="green">112</FONT>       */<a name="line.112"></a>
<FONT color="green">113</FONT>      public String dumpTopology() {<a name="line.113"></a>
<FONT color="green">114</FONT>        Map&lt;String, String&gt; rack = getSwitchMap();<a name="line.114"></a>
<FONT color="green">115</FONT>        StringBuilder builder = new StringBuilder();<a name="line.115"></a>
<FONT color="green">116</FONT>        builder.append("Mapping: ").append(toString()).append("\n");<a name="line.116"></a>
<FONT color="green">117</FONT>        if (rack != null) {<a name="line.117"></a>
<FONT color="green">118</FONT>          builder.append("Map:\n");<a name="line.118"></a>
<FONT color="green">119</FONT>          Set&lt;String&gt; switches = new HashSet&lt;String&gt;();<a name="line.119"></a>
<FONT color="green">120</FONT>          for (Map.Entry&lt;String, String&gt; entry : rack.entrySet()) {<a name="line.120"></a>
<FONT color="green">121</FONT>            builder.append("  ")<a name="line.121"></a>
<FONT color="green">122</FONT>                .append(entry.getKey())<a name="line.122"></a>
<FONT color="green">123</FONT>                .append(" -&gt; ")<a name="line.123"></a>
<FONT color="green">124</FONT>                .append(entry.getValue())<a name="line.124"></a>
<FONT color="green">125</FONT>                .append("\n");<a name="line.125"></a>
<FONT color="green">126</FONT>            switches.add(entry.getValue());<a name="line.126"></a>
<FONT color="green">127</FONT>          }<a name="line.127"></a>
<FONT color="green">128</FONT>          builder.append("Nodes: ").append(rack.size()).append("\n");<a name="line.128"></a>
<FONT color="green">129</FONT>          builder.append("Switches: ").append(switches.size()).append("\n");<a name="line.129"></a>
<FONT color="green">130</FONT>        } else {<a name="line.130"></a>
<FONT color="green">131</FONT>          builder.append("No topology information");<a name="line.131"></a>
<FONT color="green">132</FONT>        }<a name="line.132"></a>
<FONT color="green">133</FONT>        return builder.toString();<a name="line.133"></a>
<FONT color="green">134</FONT>      }<a name="line.134"></a>
<FONT color="green">135</FONT>    <a name="line.135"></a>
<FONT color="green">136</FONT>      protected boolean isSingleSwitchByScriptPolicy() {<a name="line.136"></a>
<FONT color="green">137</FONT>        return conf != null<a name="line.137"></a>
<FONT color="green">138</FONT>            &amp;&amp; conf.get(CommonConfigurationKeys.NET_TOPOLOGY_SCRIPT_FILE_NAME_KEY) == null;<a name="line.138"></a>
<FONT color="green">139</FONT>      }<a name="line.139"></a>
<FONT color="green">140</FONT>    <a name="line.140"></a>
<FONT color="green">141</FONT>      /**<a name="line.141"></a>
<FONT color="green">142</FONT>       * Query for a {@link DNSToSwitchMapping} instance being on a single<a name="line.142"></a>
<FONT color="green">143</FONT>       * switch.<a name="line.143"></a>
<FONT color="green">144</FONT>       * &lt;p/&gt;<a name="line.144"></a>
<FONT color="green">145</FONT>       * This predicate simply assumes that all mappings not derived from<a name="line.145"></a>
<FONT color="green">146</FONT>       * this class are multi-switch.<a name="line.146"></a>
<FONT color="green">147</FONT>       * @param mapping the mapping to query<a name="line.147"></a>
<FONT color="green">148</FONT>       * @return true if the base class says it is single switch, or the mapping<a name="line.148"></a>
<FONT color="green">149</FONT>       * is not derived from this class.<a name="line.149"></a>
<FONT color="green">150</FONT>       */<a name="line.150"></a>
<FONT color="green">151</FONT>      public static boolean isMappingSingleSwitch(DNSToSwitchMapping mapping) {<a name="line.151"></a>
<FONT color="green">152</FONT>        return mapping != null &amp;&amp; mapping instanceof AbstractDNSToSwitchMapping<a name="line.152"></a>
<FONT color="green">153</FONT>            &amp;&amp; ((AbstractDNSToSwitchMapping) mapping).isSingleSwitch();<a name="line.153"></a>
<FONT color="green">154</FONT>      }<a name="line.154"></a>
<FONT color="green">155</FONT>    <a name="line.155"></a>
<FONT color="green">156</FONT>    }<a name="line.156"></a>




























































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