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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.mapred.lib;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    import java.io.IOException;<a name="line.21"></a>
<FONT color="green">022</FONT>    import java.util.Iterator;<a name="line.22"></a>
<FONT color="green">023</FONT>    import java.util.TreeMap;<a name="line.23"></a>
<FONT color="green">024</FONT>    <a name="line.24"></a>
<FONT color="green">025</FONT>    import org.apache.hadoop.classification.InterfaceAudience;<a name="line.25"></a>
<FONT color="green">026</FONT>    import org.apache.hadoop.classification.InterfaceStability;<a name="line.26"></a>
<FONT color="green">027</FONT>    import org.apache.hadoop.fs.FileSystem;<a name="line.27"></a>
<FONT color="green">028</FONT>    import org.apache.hadoop.fs.Path;<a name="line.28"></a>
<FONT color="green">029</FONT>    import org.apache.hadoop.mapred.JobConf;<a name="line.29"></a>
<FONT color="green">030</FONT>    import org.apache.hadoop.mapred.FileOutputFormat;<a name="line.30"></a>
<FONT color="green">031</FONT>    import org.apache.hadoop.mapred.RecordWriter;<a name="line.31"></a>
<FONT color="green">032</FONT>    import org.apache.hadoop.mapred.Reporter;<a name="line.32"></a>
<FONT color="green">033</FONT>    import org.apache.hadoop.mapreduce.JobContext;<a name="line.33"></a>
<FONT color="green">034</FONT>    import org.apache.hadoop.mapreduce.MRJobConfig;<a name="line.34"></a>
<FONT color="green">035</FONT>    import org.apache.hadoop.util.Progressable;<a name="line.35"></a>
<FONT color="green">036</FONT>    <a name="line.36"></a>
<FONT color="green">037</FONT>    /**<a name="line.37"></a>
<FONT color="green">038</FONT>     * This abstract class extends the FileOutputFormat, allowing to write the<a name="line.38"></a>
<FONT color="green">039</FONT>     * output data to different output files. There are three basic use cases for<a name="line.39"></a>
<FONT color="green">040</FONT>     * this class.<a name="line.40"></a>
<FONT color="green">041</FONT>     * <a name="line.41"></a>
<FONT color="green">042</FONT>     * Case one: This class is used for a map reduce job with at least one reducer.<a name="line.42"></a>
<FONT color="green">043</FONT>     * The reducer wants to write data to different files depending on the actual<a name="line.43"></a>
<FONT color="green">044</FONT>     * keys. It is assumed that a key (or value) encodes the actual key (value)<a name="line.44"></a>
<FONT color="green">045</FONT>     * and the desired location for the actual key (value).<a name="line.45"></a>
<FONT color="green">046</FONT>     * <a name="line.46"></a>
<FONT color="green">047</FONT>     * Case two: This class is used for a map only job. The job wants to use an<a name="line.47"></a>
<FONT color="green">048</FONT>     * output file name that is either a part of the input file name of the input<a name="line.48"></a>
<FONT color="green">049</FONT>     * data, or some derivation of it.<a name="line.49"></a>
<FONT color="green">050</FONT>     * <a name="line.50"></a>
<FONT color="green">051</FONT>     * Case three: This class is used for a map only job. The job wants to use an<a name="line.51"></a>
<FONT color="green">052</FONT>     * output file name that depends on both the keys and the input file name,<a name="line.52"></a>
<FONT color="green">053</FONT>     */<a name="line.53"></a>
<FONT color="green">054</FONT>    @InterfaceAudience.Public<a name="line.54"></a>
<FONT color="green">055</FONT>    @InterfaceStability.Stable<a name="line.55"></a>
<FONT color="green">056</FONT>    public abstract class MultipleOutputFormat&lt;K, V&gt;<a name="line.56"></a>
<FONT color="green">057</FONT>    extends FileOutputFormat&lt;K, V&gt; {<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 a composite record writer that can write key/value data to different<a name="line.60"></a>
<FONT color="green">061</FONT>       * output files<a name="line.61"></a>
<FONT color="green">062</FONT>       * <a name="line.62"></a>
<FONT color="green">063</FONT>       * @param fs<a name="line.63"></a>
<FONT color="green">064</FONT>       *          the file system to use<a name="line.64"></a>
<FONT color="green">065</FONT>       * @param job<a name="line.65"></a>
<FONT color="green">066</FONT>       *          the job conf for the job<a name="line.66"></a>
<FONT color="green">067</FONT>       * @param name<a name="line.67"></a>
<FONT color="green">068</FONT>       *          the leaf file name for the output file (such as part-00000")<a name="line.68"></a>
<FONT color="green">069</FONT>       * @param arg3<a name="line.69"></a>
<FONT color="green">070</FONT>       *          a progressable for reporting progress.<a name="line.70"></a>
<FONT color="green">071</FONT>       * @return a composite record writer<a name="line.71"></a>
<FONT color="green">072</FONT>       * @throws IOException<a name="line.72"></a>
<FONT color="green">073</FONT>       */<a name="line.73"></a>
<FONT color="green">074</FONT>      public RecordWriter&lt;K, V&gt; getRecordWriter(FileSystem fs, JobConf job,<a name="line.74"></a>
<FONT color="green">075</FONT>          String name, Progressable arg3) throws IOException {<a name="line.75"></a>
<FONT color="green">076</FONT>    <a name="line.76"></a>
<FONT color="green">077</FONT>        final FileSystem myFS = fs;<a name="line.77"></a>
<FONT color="green">078</FONT>        final String myName = generateLeafFileName(name);<a name="line.78"></a>
<FONT color="green">079</FONT>        final JobConf myJob = job;<a name="line.79"></a>
<FONT color="green">080</FONT>        final Progressable myProgressable = arg3;<a name="line.80"></a>
<FONT color="green">081</FONT>    <a name="line.81"></a>
<FONT color="green">082</FONT>        return new RecordWriter&lt;K, V&gt;() {<a name="line.82"></a>
<FONT color="green">083</FONT>    <a name="line.83"></a>
<FONT color="green">084</FONT>          // a cache storing the record writers for different output files.<a name="line.84"></a>
<FONT color="green">085</FONT>          TreeMap&lt;String, RecordWriter&lt;K, V&gt;&gt; recordWriters = new TreeMap&lt;String, RecordWriter&lt;K, V&gt;&gt;();<a name="line.85"></a>
<FONT color="green">086</FONT>    <a name="line.86"></a>
<FONT color="green">087</FONT>          public void write(K key, V value) throws IOException {<a name="line.87"></a>
<FONT color="green">088</FONT>    <a name="line.88"></a>
<FONT color="green">089</FONT>            // get the file name based on the key<a name="line.89"></a>
<FONT color="green">090</FONT>            String keyBasedPath = generateFileNameForKeyValue(key, value, myName);<a name="line.90"></a>
<FONT color="green">091</FONT>    <a name="line.91"></a>
<FONT color="green">092</FONT>            // get the file name based on the input file name<a name="line.92"></a>
<FONT color="green">093</FONT>            String finalPath = getInputFileBasedOutputFileName(myJob, keyBasedPath);<a name="line.93"></a>
<FONT color="green">094</FONT>    <a name="line.94"></a>
<FONT color="green">095</FONT>            // get the actual key<a name="line.95"></a>
<FONT color="green">096</FONT>            K actualKey = generateActualKey(key, value);<a name="line.96"></a>
<FONT color="green">097</FONT>            V actualValue = generateActualValue(key, value);<a name="line.97"></a>
<FONT color="green">098</FONT>    <a name="line.98"></a>
<FONT color="green">099</FONT>            RecordWriter&lt;K, V&gt; rw = this.recordWriters.get(finalPath);<a name="line.99"></a>
<FONT color="green">100</FONT>            if (rw == null) {<a name="line.100"></a>
<FONT color="green">101</FONT>              // if we don't have the record writer yet for the final path, create<a name="line.101"></a>
<FONT color="green">102</FONT>              // one<a name="line.102"></a>
<FONT color="green">103</FONT>              // and add it to the cache<a name="line.103"></a>
<FONT color="green">104</FONT>              rw = getBaseRecordWriter(myFS, myJob, finalPath, myProgressable);<a name="line.104"></a>
<FONT color="green">105</FONT>              this.recordWriters.put(finalPath, rw);<a name="line.105"></a>
<FONT color="green">106</FONT>            }<a name="line.106"></a>
<FONT color="green">107</FONT>            rw.write(actualKey, actualValue);<a name="line.107"></a>
<FONT color="green">108</FONT>          };<a name="line.108"></a>
<FONT color="green">109</FONT>    <a name="line.109"></a>
<FONT color="green">110</FONT>          public void close(Reporter reporter) throws IOException {<a name="line.110"></a>
<FONT color="green">111</FONT>            Iterator&lt;String&gt; keys = this.recordWriters.keySet().iterator();<a name="line.111"></a>
<FONT color="green">112</FONT>            while (keys.hasNext()) {<a name="line.112"></a>
<FONT color="green">113</FONT>              RecordWriter&lt;K, V&gt; rw = this.recordWriters.get(keys.next());<a name="line.113"></a>
<FONT color="green">114</FONT>              rw.close(reporter);<a name="line.114"></a>
<FONT color="green">115</FONT>            }<a name="line.115"></a>
<FONT color="green">116</FONT>            this.recordWriters.clear();<a name="line.116"></a>
<FONT color="green">117</FONT>          };<a name="line.117"></a>
<FONT color="green">118</FONT>        };<a name="line.118"></a>
<FONT color="green">119</FONT>      }<a name="line.119"></a>
<FONT color="green">120</FONT>    <a name="line.120"></a>
<FONT color="green">121</FONT>      /**<a name="line.121"></a>
<FONT color="green">122</FONT>       * Generate the leaf name for the output file name. The default behavior does<a name="line.122"></a>
<FONT color="green">123</FONT>       * not change the leaf file name (such as part-00000)<a name="line.123"></a>
<FONT color="green">124</FONT>       * <a name="line.124"></a>
<FONT color="green">125</FONT>       * @param name<a name="line.125"></a>
<FONT color="green">126</FONT>       *          the leaf file name for the output file<a name="line.126"></a>
<FONT color="green">127</FONT>       * @return the given leaf file name<a name="line.127"></a>
<FONT color="green">128</FONT>       */<a name="line.128"></a>
<FONT color="green">129</FONT>      protected String generateLeafFileName(String name) {<a name="line.129"></a>
<FONT color="green">130</FONT>        return name;<a name="line.130"></a>
<FONT color="green">131</FONT>      }<a name="line.131"></a>
<FONT color="green">132</FONT>    <a name="line.132"></a>
<FONT color="green">133</FONT>      /**<a name="line.133"></a>
<FONT color="green">134</FONT>       * Generate the file output file name based on the given key and the leaf file<a name="line.134"></a>
<FONT color="green">135</FONT>       * name. The default behavior is that the file name does not depend on the<a name="line.135"></a>
<FONT color="green">136</FONT>       * key.<a name="line.136"></a>
<FONT color="green">137</FONT>       * <a name="line.137"></a>
<FONT color="green">138</FONT>       * @param key<a name="line.138"></a>
<FONT color="green">139</FONT>       *          the key of the output data<a name="line.139"></a>
<FONT color="green">140</FONT>       * @param name<a name="line.140"></a>
<FONT color="green">141</FONT>       *          the leaf file name<a name="line.141"></a>
<FONT color="green">142</FONT>       * @return generated file name<a name="line.142"></a>
<FONT color="green">143</FONT>       */<a name="line.143"></a>
<FONT color="green">144</FONT>      protected String generateFileNameForKeyValue(K key, V value, String name) {<a name="line.144"></a>
<FONT color="green">145</FONT>        return name;<a name="line.145"></a>
<FONT color="green">146</FONT>      }<a name="line.146"></a>
<FONT color="green">147</FONT>    <a name="line.147"></a>
<FONT color="green">148</FONT>      /**<a name="line.148"></a>
<FONT color="green">149</FONT>       * Generate the actual key from the given key/value. The default behavior is that<a name="line.149"></a>
<FONT color="green">150</FONT>       * the actual key is equal to the given key<a name="line.150"></a>
<FONT color="green">151</FONT>       * <a name="line.151"></a>
<FONT color="green">152</FONT>       * @param key<a name="line.152"></a>
<FONT color="green">153</FONT>       *          the key of the output data<a name="line.153"></a>
<FONT color="green">154</FONT>       * @param value<a name="line.154"></a>
<FONT color="green">155</FONT>       *          the value of the output data<a name="line.155"></a>
<FONT color="green">156</FONT>       * @return the actual key derived from the given key/value<a name="line.156"></a>
<FONT color="green">157</FONT>       */<a name="line.157"></a>
<FONT color="green">158</FONT>      protected K generateActualKey(K key, V value) {<a name="line.158"></a>
<FONT color="green">159</FONT>        return key;<a name="line.159"></a>
<FONT color="green">160</FONT>      }<a name="line.160"></a>
<FONT color="green">161</FONT>      <a name="line.161"></a>
<FONT color="green">162</FONT>      /**<a name="line.162"></a>
<FONT color="green">163</FONT>       * Generate the actual value from the given key and value. The default behavior is that<a name="line.163"></a>
<FONT color="green">164</FONT>       * the actual value is equal to the given value<a name="line.164"></a>
<FONT color="green">165</FONT>       * <a name="line.165"></a>
<FONT color="green">166</FONT>       * @param key<a name="line.166"></a>
<FONT color="green">167</FONT>       *          the key of the output data<a name="line.167"></a>
<FONT color="green">168</FONT>       * @param value<a name="line.168"></a>
<FONT color="green">169</FONT>       *          the value of the output data<a name="line.169"></a>
<FONT color="green">170</FONT>       * @return the actual value derived from the given key/value<a name="line.170"></a>
<FONT color="green">171</FONT>       */<a name="line.171"></a>
<FONT color="green">172</FONT>      protected V generateActualValue(K key, V value) {<a name="line.172"></a>
<FONT color="green">173</FONT>        return value;<a name="line.173"></a>
<FONT color="green">174</FONT>      }<a name="line.174"></a>
<FONT color="green">175</FONT>      <a name="line.175"></a>
<FONT color="green">176</FONT>    <a name="line.176"></a>
<FONT color="green">177</FONT>      /**<a name="line.177"></a>
<FONT color="green">178</FONT>       * Generate the outfile name based on a given anme and the input file name. If<a name="line.178"></a>
<FONT color="green">179</FONT>       * the {@link JobContext#MAP_INPUT_FILE} does not exists (i.e. this is not for a map only job),<a name="line.179"></a>
<FONT color="green">180</FONT>       * the given name is returned unchanged. If the config value for<a name="line.180"></a>
<FONT color="green">181</FONT>       * "num.of.trailing.legs.to.use" is not set, or set 0 or negative, the given<a name="line.181"></a>
<FONT color="green">182</FONT>       * name is returned unchanged. Otherwise, return a file name consisting of the<a name="line.182"></a>
<FONT color="green">183</FONT>       * N trailing legs of the input file name where N is the config value for<a name="line.183"></a>
<FONT color="green">184</FONT>       * "num.of.trailing.legs.to.use".<a name="line.184"></a>
<FONT color="green">185</FONT>       * <a name="line.185"></a>
<FONT color="green">186</FONT>       * @param job<a name="line.186"></a>
<FONT color="green">187</FONT>       *          the job config<a name="line.187"></a>
<FONT color="green">188</FONT>       * @param name<a name="line.188"></a>
<FONT color="green">189</FONT>       *          the output file name<a name="line.189"></a>
<FONT color="green">190</FONT>       * @return the outfile name based on a given anme and the input file name.<a name="line.190"></a>
<FONT color="green">191</FONT>       */<a name="line.191"></a>
<FONT color="green">192</FONT>      protected String getInputFileBasedOutputFileName(JobConf job, String name) {<a name="line.192"></a>
<FONT color="green">193</FONT>        String infilepath = job.get(MRJobConfig.MAP_INPUT_FILE);<a name="line.193"></a>
<FONT color="green">194</FONT>        if (infilepath == null) {<a name="line.194"></a>
<FONT color="green">195</FONT>          // if the {@link JobContext#MAP_INPUT_FILE} does not exists,<a name="line.195"></a>
<FONT color="green">196</FONT>          // then return the given name<a name="line.196"></a>
<FONT color="green">197</FONT>          return name;<a name="line.197"></a>
<FONT color="green">198</FONT>        }<a name="line.198"></a>
<FONT color="green">199</FONT>        int numOfTrailingLegsToUse = job.getInt("mapred.outputformat.numOfTrailingLegs", 0);<a name="line.199"></a>
<FONT color="green">200</FONT>        if (numOfTrailingLegsToUse &lt;= 0) {<a name="line.200"></a>
<FONT color="green">201</FONT>          return name;<a name="line.201"></a>
<FONT color="green">202</FONT>        }<a name="line.202"></a>
<FONT color="green">203</FONT>        Path infile = new Path(infilepath);<a name="line.203"></a>
<FONT color="green">204</FONT>        Path parent = infile.getParent();<a name="line.204"></a>
<FONT color="green">205</FONT>        String midName = infile.getName();<a name="line.205"></a>
<FONT color="green">206</FONT>        Path outPath = new Path(midName);<a name="line.206"></a>
<FONT color="green">207</FONT>        for (int i = 1; i &lt; numOfTrailingLegsToUse; i++) {<a name="line.207"></a>
<FONT color="green">208</FONT>          if (parent == null) break;<a name="line.208"></a>
<FONT color="green">209</FONT>          midName = parent.getName();<a name="line.209"></a>
<FONT color="green">210</FONT>          if (midName.length() == 0) break;<a name="line.210"></a>
<FONT color="green">211</FONT>          parent = parent.getParent();<a name="line.211"></a>
<FONT color="green">212</FONT>          outPath = new Path(midName, outPath);<a name="line.212"></a>
<FONT color="green">213</FONT>        }<a name="line.213"></a>
<FONT color="green">214</FONT>        return outPath.toString();<a name="line.214"></a>
<FONT color="green">215</FONT>      }<a name="line.215"></a>
<FONT color="green">216</FONT>    <a name="line.216"></a>
<FONT color="green">217</FONT>      /**<a name="line.217"></a>
<FONT color="green">218</FONT>       * <a name="line.218"></a>
<FONT color="green">219</FONT>       * @param fs<a name="line.219"></a>
<FONT color="green">220</FONT>       *          the file system to use<a name="line.220"></a>
<FONT color="green">221</FONT>       * @param job<a name="line.221"></a>
<FONT color="green">222</FONT>       *          a job conf object<a name="line.222"></a>
<FONT color="green">223</FONT>       * @param name<a name="line.223"></a>
<FONT color="green">224</FONT>       *          the name of the file over which a record writer object will be<a name="line.224"></a>
<FONT color="green">225</FONT>       *          constructed<a name="line.225"></a>
<FONT color="green">226</FONT>       * @param arg3<a name="line.226"></a>
<FONT color="green">227</FONT>       *          a progressable object<a name="line.227"></a>
<FONT color="green">228</FONT>       * @return A RecordWriter object over the given file<a name="line.228"></a>
<FONT color="green">229</FONT>       * @throws IOException<a name="line.229"></a>
<FONT color="green">230</FONT>       */<a name="line.230"></a>
<FONT color="green">231</FONT>      abstract protected RecordWriter&lt;K, V&gt; getBaseRecordWriter(FileSystem fs,<a name="line.231"></a>
<FONT color="green">232</FONT>          JobConf job, String name, Progressable arg3) throws IOException;<a name="line.232"></a>
<FONT color="green">233</FONT>    }<a name="line.233"></a>




























































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