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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.join;<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.ArrayList;<a name="line.22"></a>
<FONT color="green">023</FONT>    import java.util.Comparator;<a name="line.23"></a>
<FONT color="green">024</FONT>    import java.util.PriorityQueue;<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>    import org.apache.hadoop.classification.InterfaceAudience;<a name="line.26"></a>
<FONT color="green">027</FONT>    import org.apache.hadoop.classification.InterfaceStability;<a name="line.27"></a>
<FONT color="green">028</FONT>    import org.apache.hadoop.conf.Configurable;<a name="line.28"></a>
<FONT color="green">029</FONT>    import org.apache.hadoop.conf.Configuration;<a name="line.29"></a>
<FONT color="green">030</FONT>    import org.apache.hadoop.io.Writable;<a name="line.30"></a>
<FONT color="green">031</FONT>    import org.apache.hadoop.io.WritableComparable;<a name="line.31"></a>
<FONT color="green">032</FONT>    import org.apache.hadoop.io.WritableComparator;<a name="line.32"></a>
<FONT color="green">033</FONT>    import org.apache.hadoop.io.WritableUtils;<a name="line.33"></a>
<FONT color="green">034</FONT>    import org.apache.hadoop.mapred.RecordReader;<a name="line.34"></a>
<FONT color="green">035</FONT>    import org.apache.hadoop.util.ReflectionUtils;<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>     * A RecordReader that can effect joins of RecordReaders sharing a common key<a name="line.38"></a>
<FONT color="green">039</FONT>     * type and partitioning.<a name="line.39"></a>
<FONT color="green">040</FONT>     */<a name="line.40"></a>
<FONT color="green">041</FONT>    @InterfaceAudience.Public<a name="line.41"></a>
<FONT color="green">042</FONT>    @InterfaceStability.Stable<a name="line.42"></a>
<FONT color="green">043</FONT>    public abstract class CompositeRecordReader&lt;<a name="line.43"></a>
<FONT color="green">044</FONT>        K extends WritableComparable, // key type<a name="line.44"></a>
<FONT color="green">045</FONT>        V extends Writable,           // accepts RecordReader&lt;K,V&gt; as children<a name="line.45"></a>
<FONT color="green">046</FONT>        X extends Writable&gt;           // emits Writables of this type<a name="line.46"></a>
<FONT color="green">047</FONT>        implements Configurable {<a name="line.47"></a>
<FONT color="green">048</FONT>    <a name="line.48"></a>
<FONT color="green">049</FONT>    <a name="line.49"></a>
<FONT color="green">050</FONT>      private int id;<a name="line.50"></a>
<FONT color="green">051</FONT>      private Configuration conf;<a name="line.51"></a>
<FONT color="green">052</FONT>      private final ResetableIterator&lt;X&gt; EMPTY = new ResetableIterator.EMPTY&lt;X&gt;();<a name="line.52"></a>
<FONT color="green">053</FONT>    <a name="line.53"></a>
<FONT color="green">054</FONT>      private WritableComparator cmp;<a name="line.54"></a>
<FONT color="green">055</FONT>      private Class&lt;? extends WritableComparable&gt; keyclass;<a name="line.55"></a>
<FONT color="green">056</FONT>      private PriorityQueue&lt;ComposableRecordReader&lt;K,?&gt;&gt; q;<a name="line.56"></a>
<FONT color="green">057</FONT>    <a name="line.57"></a>
<FONT color="green">058</FONT>      protected final JoinCollector jc;<a name="line.58"></a>
<FONT color="green">059</FONT>      protected final ComposableRecordReader&lt;K,? extends V&gt;[] kids;<a name="line.59"></a>
<FONT color="green">060</FONT>    <a name="line.60"></a>
<FONT color="green">061</FONT>      protected abstract boolean combine(Object[] srcs, TupleWritable value);<a name="line.61"></a>
<FONT color="green">062</FONT>    <a name="line.62"></a>
<FONT color="green">063</FONT>      /**<a name="line.63"></a>
<FONT color="green">064</FONT>       * Create a RecordReader with &lt;tt&gt;capacity&lt;/tt&gt; children to position<a name="line.64"></a>
<FONT color="green">065</FONT>       * &lt;tt&gt;id&lt;/tt&gt; in the parent reader.<a name="line.65"></a>
<FONT color="green">066</FONT>       * The id of a root CompositeRecordReader is -1 by convention, but relying<a name="line.66"></a>
<FONT color="green">067</FONT>       * on this is not recommended.<a name="line.67"></a>
<FONT color="green">068</FONT>       */<a name="line.68"></a>
<FONT color="green">069</FONT>      @SuppressWarnings("unchecked") // Generic array assignment<a name="line.69"></a>
<FONT color="green">070</FONT>      public CompositeRecordReader(int id, int capacity,<a name="line.70"></a>
<FONT color="green">071</FONT>          Class&lt;? extends WritableComparator&gt; cmpcl)<a name="line.71"></a>
<FONT color="green">072</FONT>          throws IOException {<a name="line.72"></a>
<FONT color="green">073</FONT>        assert capacity &gt; 0 : "Invalid capacity";<a name="line.73"></a>
<FONT color="green">074</FONT>        this.id = id;<a name="line.74"></a>
<FONT color="green">075</FONT>        if (null != cmpcl) {<a name="line.75"></a>
<FONT color="green">076</FONT>          cmp = ReflectionUtils.newInstance(cmpcl, null);<a name="line.76"></a>
<FONT color="green">077</FONT>          q = new PriorityQueue&lt;ComposableRecordReader&lt;K,?&gt;&gt;(3,<a name="line.77"></a>
<FONT color="green">078</FONT>              new Comparator&lt;ComposableRecordReader&lt;K,?&gt;&gt;() {<a name="line.78"></a>
<FONT color="green">079</FONT>                public int compare(ComposableRecordReader&lt;K,?&gt; o1,<a name="line.79"></a>
<FONT color="green">080</FONT>                                   ComposableRecordReader&lt;K,?&gt; o2) {<a name="line.80"></a>
<FONT color="green">081</FONT>                  return cmp.compare(o1.key(), o2.key());<a name="line.81"></a>
<FONT color="green">082</FONT>                }<a name="line.82"></a>
<FONT color="green">083</FONT>              });<a name="line.83"></a>
<FONT color="green">084</FONT>        }<a name="line.84"></a>
<FONT color="green">085</FONT>        jc = new JoinCollector(capacity);<a name="line.85"></a>
<FONT color="green">086</FONT>        kids = new ComposableRecordReader[capacity];<a name="line.86"></a>
<FONT color="green">087</FONT>      }<a name="line.87"></a>
<FONT color="green">088</FONT>    <a name="line.88"></a>
<FONT color="green">089</FONT>      /**<a name="line.89"></a>
<FONT color="green">090</FONT>       * Return the position in the collector this class occupies.<a name="line.90"></a>
<FONT color="green">091</FONT>       */<a name="line.91"></a>
<FONT color="green">092</FONT>      public int id() {<a name="line.92"></a>
<FONT color="green">093</FONT>        return id;<a name="line.93"></a>
<FONT color="green">094</FONT>      }<a name="line.94"></a>
<FONT color="green">095</FONT>    <a name="line.95"></a>
<FONT color="green">096</FONT>      /**<a name="line.96"></a>
<FONT color="green">097</FONT>       * {@inheritDoc}<a name="line.97"></a>
<FONT color="green">098</FONT>       */<a name="line.98"></a>
<FONT color="green">099</FONT>      public void setConf(Configuration conf) {<a name="line.99"></a>
<FONT color="green">100</FONT>        this.conf = conf;<a name="line.100"></a>
<FONT color="green">101</FONT>      }<a name="line.101"></a>
<FONT color="green">102</FONT>    <a name="line.102"></a>
<FONT color="green">103</FONT>      /**<a name="line.103"></a>
<FONT color="green">104</FONT>       * {@inheritDoc}<a name="line.104"></a>
<FONT color="green">105</FONT>       */<a name="line.105"></a>
<FONT color="green">106</FONT>      public Configuration getConf() {<a name="line.106"></a>
<FONT color="green">107</FONT>        return conf;<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>      /**<a name="line.110"></a>
<FONT color="green">111</FONT>       * Return sorted list of RecordReaders for this composite.<a name="line.111"></a>
<FONT color="green">112</FONT>       */<a name="line.112"></a>
<FONT color="green">113</FONT>      protected PriorityQueue&lt;ComposableRecordReader&lt;K,?&gt;&gt; getRecordReaderQueue() {<a name="line.113"></a>
<FONT color="green">114</FONT>        return q;<a name="line.114"></a>
<FONT color="green">115</FONT>      }<a name="line.115"></a>
<FONT color="green">116</FONT>    <a name="line.116"></a>
<FONT color="green">117</FONT>      /**<a name="line.117"></a>
<FONT color="green">118</FONT>       * Return comparator defining the ordering for RecordReaders in this<a name="line.118"></a>
<FONT color="green">119</FONT>       * composite.<a name="line.119"></a>
<FONT color="green">120</FONT>       */<a name="line.120"></a>
<FONT color="green">121</FONT>      protected WritableComparator getComparator() {<a name="line.121"></a>
<FONT color="green">122</FONT>        return cmp;<a name="line.122"></a>
<FONT color="green">123</FONT>      }<a name="line.123"></a>
<FONT color="green">124</FONT>    <a name="line.124"></a>
<FONT color="green">125</FONT>      /**<a name="line.125"></a>
<FONT color="green">126</FONT>       * Add a RecordReader to this collection.<a name="line.126"></a>
<FONT color="green">127</FONT>       * The id() of a RecordReader determines where in the Tuple its<a name="line.127"></a>
<FONT color="green">128</FONT>       * entry will appear. Adding RecordReaders with the same id has<a name="line.128"></a>
<FONT color="green">129</FONT>       * undefined behavior.<a name="line.129"></a>
<FONT color="green">130</FONT>       */<a name="line.130"></a>
<FONT color="green">131</FONT>      public void add(ComposableRecordReader&lt;K,? extends V&gt; rr) throws IOException {<a name="line.131"></a>
<FONT color="green">132</FONT>        kids[rr.id()] = rr;<a name="line.132"></a>
<FONT color="green">133</FONT>        if (null == q) {<a name="line.133"></a>
<FONT color="green">134</FONT>          cmp = WritableComparator.get(rr.createKey().getClass());<a name="line.134"></a>
<FONT color="green">135</FONT>          q = new PriorityQueue&lt;ComposableRecordReader&lt;K,?&gt;&gt;(3,<a name="line.135"></a>
<FONT color="green">136</FONT>              new Comparator&lt;ComposableRecordReader&lt;K,?&gt;&gt;() {<a name="line.136"></a>
<FONT color="green">137</FONT>                public int compare(ComposableRecordReader&lt;K,?&gt; o1,<a name="line.137"></a>
<FONT color="green">138</FONT>                                   ComposableRecordReader&lt;K,?&gt; o2) {<a name="line.138"></a>
<FONT color="green">139</FONT>                  return cmp.compare(o1.key(), o2.key());<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>        }<a name="line.142"></a>
<FONT color="green">143</FONT>        if (rr.hasNext()) {<a name="line.143"></a>
<FONT color="green">144</FONT>          q.add(rr);<a name="line.144"></a>
<FONT color="green">145</FONT>        }<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>       * Collector for join values.<a name="line.149"></a>
<FONT color="green">150</FONT>       * This accumulates values for a given key from the child RecordReaders. If<a name="line.150"></a>
<FONT color="green">151</FONT>       * one or more child RR contain duplicate keys, this will emit the cross<a name="line.151"></a>
<FONT color="green">152</FONT>       * product of the associated values until exhausted.<a name="line.152"></a>
<FONT color="green">153</FONT>       */<a name="line.153"></a>
<FONT color="green">154</FONT>      class JoinCollector {<a name="line.154"></a>
<FONT color="green">155</FONT>        private K key;<a name="line.155"></a>
<FONT color="green">156</FONT>        private ResetableIterator&lt;X&gt;[] iters;<a name="line.156"></a>
<FONT color="green">157</FONT>        private int pos = -1;<a name="line.157"></a>
<FONT color="green">158</FONT>        private boolean first = true;<a name="line.158"></a>
<FONT color="green">159</FONT>    <a name="line.159"></a>
<FONT color="green">160</FONT>        /**<a name="line.160"></a>
<FONT color="green">161</FONT>         * Construct a collector capable of handling the specified number of<a name="line.161"></a>
<FONT color="green">162</FONT>         * children.<a name="line.162"></a>
<FONT color="green">163</FONT>         */<a name="line.163"></a>
<FONT color="green">164</FONT>        @SuppressWarnings("unchecked") // Generic array assignment<a name="line.164"></a>
<FONT color="green">165</FONT>        public JoinCollector(int card) {<a name="line.165"></a>
<FONT color="green">166</FONT>          iters = new ResetableIterator[card];<a name="line.166"></a>
<FONT color="green">167</FONT>          for (int i = 0; i &lt; iters.length; ++i) {<a name="line.167"></a>
<FONT color="green">168</FONT>            iters[i] = EMPTY;<a name="line.168"></a>
<FONT color="green">169</FONT>          }<a name="line.169"></a>
<FONT color="green">170</FONT>        }<a name="line.170"></a>
<FONT color="green">171</FONT>    <a name="line.171"></a>
<FONT color="green">172</FONT>        /**<a name="line.172"></a>
<FONT color="green">173</FONT>         * Register a given iterator at position id.<a name="line.173"></a>
<FONT color="green">174</FONT>         */<a name="line.174"></a>
<FONT color="green">175</FONT>        public void add(int id, ResetableIterator&lt;X&gt; i)<a name="line.175"></a>
<FONT color="green">176</FONT>            throws IOException {<a name="line.176"></a>
<FONT color="green">177</FONT>          iters[id] = i;<a name="line.177"></a>
<FONT color="green">178</FONT>        }<a name="line.178"></a>
<FONT color="green">179</FONT>    <a name="line.179"></a>
<FONT color="green">180</FONT>        /**<a name="line.180"></a>
<FONT color="green">181</FONT>         * Return the key associated with this collection.<a name="line.181"></a>
<FONT color="green">182</FONT>         */<a name="line.182"></a>
<FONT color="green">183</FONT>        public K key() {<a name="line.183"></a>
<FONT color="green">184</FONT>          return key;<a name="line.184"></a>
<FONT color="green">185</FONT>        }<a name="line.185"></a>
<FONT color="green">186</FONT>    <a name="line.186"></a>
<FONT color="green">187</FONT>        /**<a name="line.187"></a>
<FONT color="green">188</FONT>         * Codify the contents of the collector to be iterated over.<a name="line.188"></a>
<FONT color="green">189</FONT>         * When this is called, all RecordReaders registered for this<a name="line.189"></a>
<FONT color="green">190</FONT>         * key should have added ResetableIterators.<a name="line.190"></a>
<FONT color="green">191</FONT>         */<a name="line.191"></a>
<FONT color="green">192</FONT>        public void reset(K key) {<a name="line.192"></a>
<FONT color="green">193</FONT>          this.key = key;<a name="line.193"></a>
<FONT color="green">194</FONT>          first = true;<a name="line.194"></a>
<FONT color="green">195</FONT>          pos = iters.length - 1;<a name="line.195"></a>
<FONT color="green">196</FONT>          for (int i = 0; i &lt; iters.length; ++i) {<a name="line.196"></a>
<FONT color="green">197</FONT>            iters[i].reset();<a name="line.197"></a>
<FONT color="green">198</FONT>          }<a name="line.198"></a>
<FONT color="green">199</FONT>        }<a name="line.199"></a>
<FONT color="green">200</FONT>    <a name="line.200"></a>
<FONT color="green">201</FONT>        /**<a name="line.201"></a>
<FONT color="green">202</FONT>         * Clear all state information.<a name="line.202"></a>
<FONT color="green">203</FONT>         */<a name="line.203"></a>
<FONT color="green">204</FONT>        public void clear() {<a name="line.204"></a>
<FONT color="green">205</FONT>          key = null;<a name="line.205"></a>
<FONT color="green">206</FONT>          pos = -1;<a name="line.206"></a>
<FONT color="green">207</FONT>          for (int i = 0; i &lt; iters.length; ++i) {<a name="line.207"></a>
<FONT color="green">208</FONT>            iters[i].clear();<a name="line.208"></a>
<FONT color="green">209</FONT>            iters[i] = EMPTY;<a name="line.209"></a>
<FONT color="green">210</FONT>          }<a name="line.210"></a>
<FONT color="green">211</FONT>        }<a name="line.211"></a>
<FONT color="green">212</FONT>    <a name="line.212"></a>
<FONT color="green">213</FONT>        /**<a name="line.213"></a>
<FONT color="green">214</FONT>         * Returns false if exhausted or if reset(K) has not been called.<a name="line.214"></a>
<FONT color="green">215</FONT>         */<a name="line.215"></a>
<FONT color="green">216</FONT>        protected boolean hasNext() {<a name="line.216"></a>
<FONT color="green">217</FONT>          return !(pos &lt; 0);<a name="line.217"></a>
<FONT color="green">218</FONT>        }<a name="line.218"></a>
<FONT color="green">219</FONT>    <a name="line.219"></a>
<FONT color="green">220</FONT>        /**<a name="line.220"></a>
<FONT color="green">221</FONT>         * Populate Tuple from iterators.<a name="line.221"></a>
<FONT color="green">222</FONT>         * It should be the case that, given iterators i_1...i_n over values from<a name="line.222"></a>
<FONT color="green">223</FONT>         * sources s_1...s_n sharing key k, repeated calls to next should yield<a name="line.223"></a>
<FONT color="green">224</FONT>         * I x I.<a name="line.224"></a>
<FONT color="green">225</FONT>         */<a name="line.225"></a>
<FONT color="green">226</FONT>        @SuppressWarnings("unchecked") // No static typeinfo on Tuples<a name="line.226"></a>
<FONT color="green">227</FONT>        protected boolean next(TupleWritable val) throws IOException {<a name="line.227"></a>
<FONT color="green">228</FONT>          if (first) {<a name="line.228"></a>
<FONT color="green">229</FONT>            int i = -1;<a name="line.229"></a>
<FONT color="green">230</FONT>            for (pos = 0; pos &lt; iters.length; ++pos) {<a name="line.230"></a>
<FONT color="green">231</FONT>              if (iters[pos].hasNext() &amp;&amp; iters[pos].next((X)val.get(pos))) {<a name="line.231"></a>
<FONT color="green">232</FONT>                i = pos;<a name="line.232"></a>
<FONT color="green">233</FONT>                val.setWritten(i);<a name="line.233"></a>
<FONT color="green">234</FONT>              }<a name="line.234"></a>
<FONT color="green">235</FONT>            }<a name="line.235"></a>
<FONT color="green">236</FONT>            pos = i;<a name="line.236"></a>
<FONT color="green">237</FONT>            first = false;<a name="line.237"></a>
<FONT color="green">238</FONT>            if (pos &lt; 0) {<a name="line.238"></a>
<FONT color="green">239</FONT>              clear();<a name="line.239"></a>
<FONT color="green">240</FONT>              return false;<a name="line.240"></a>
<FONT color="green">241</FONT>            }<a name="line.241"></a>
<FONT color="green">242</FONT>            return true;<a name="line.242"></a>
<FONT color="green">243</FONT>          }<a name="line.243"></a>
<FONT color="green">244</FONT>          while (0 &lt;= pos &amp;&amp; !(iters[pos].hasNext() &amp;&amp;<a name="line.244"></a>
<FONT color="green">245</FONT>                               iters[pos].next((X)val.get(pos)))) {<a name="line.245"></a>
<FONT color="green">246</FONT>            --pos;<a name="line.246"></a>
<FONT color="green">247</FONT>          }<a name="line.247"></a>
<FONT color="green">248</FONT>          if (pos &lt; 0) {<a name="line.248"></a>
<FONT color="green">249</FONT>            clear();<a name="line.249"></a>
<FONT color="green">250</FONT>            return false;<a name="line.250"></a>
<FONT color="green">251</FONT>          }<a name="line.251"></a>
<FONT color="green">252</FONT>          val.setWritten(pos);<a name="line.252"></a>
<FONT color="green">253</FONT>          for (int i = 0; i &lt; pos; ++i) {<a name="line.253"></a>
<FONT color="green">254</FONT>            if (iters[i].replay((X)val.get(i))) {<a name="line.254"></a>
<FONT color="green">255</FONT>              val.setWritten(i);<a name="line.255"></a>
<FONT color="green">256</FONT>            }<a name="line.256"></a>
<FONT color="green">257</FONT>          }<a name="line.257"></a>
<FONT color="green">258</FONT>          while (pos + 1 &lt; iters.length) {<a name="line.258"></a>
<FONT color="green">259</FONT>            ++pos;<a name="line.259"></a>
<FONT color="green">260</FONT>            iters[pos].reset();<a name="line.260"></a>
<FONT color="green">261</FONT>            if (iters[pos].hasNext() &amp;&amp; iters[pos].next((X)val.get(pos))) {<a name="line.261"></a>
<FONT color="green">262</FONT>              val.setWritten(pos);<a name="line.262"></a>
<FONT color="green">263</FONT>            }<a name="line.263"></a>
<FONT color="green">264</FONT>          }<a name="line.264"></a>
<FONT color="green">265</FONT>          return true;<a name="line.265"></a>
<FONT color="green">266</FONT>        }<a name="line.266"></a>
<FONT color="green">267</FONT>    <a name="line.267"></a>
<FONT color="green">268</FONT>        /**<a name="line.268"></a>
<FONT color="green">269</FONT>         * Replay the last Tuple emitted.<a name="line.269"></a>
<FONT color="green">270</FONT>         */<a name="line.270"></a>
<FONT color="green">271</FONT>        @SuppressWarnings("unchecked") // No static typeinfo on Tuples<a name="line.271"></a>
<FONT color="green">272</FONT>        public boolean replay(TupleWritable val) throws IOException {<a name="line.272"></a>
<FONT color="green">273</FONT>          // The last emitted tuple might have drawn on an empty source;<a name="line.273"></a>
<FONT color="green">274</FONT>          // it can't be cleared prematurely, b/c there may be more duplicate<a name="line.274"></a>
<FONT color="green">275</FONT>          // keys in iterator positions &lt; pos<a name="line.275"></a>
<FONT color="green">276</FONT>          assert !first;<a name="line.276"></a>
<FONT color="green">277</FONT>          boolean ret = false;<a name="line.277"></a>
<FONT color="green">278</FONT>          for (int i = 0; i &lt; iters.length; ++i) {<a name="line.278"></a>
<FONT color="green">279</FONT>            if (iters[i].replay((X)val.get(i))) {<a name="line.279"></a>
<FONT color="green">280</FONT>              val.setWritten(i);<a name="line.280"></a>
<FONT color="green">281</FONT>              ret = true;<a name="line.281"></a>
<FONT color="green">282</FONT>            }<a name="line.282"></a>
<FONT color="green">283</FONT>          }<a name="line.283"></a>
<FONT color="green">284</FONT>          return ret;<a name="line.284"></a>
<FONT color="green">285</FONT>        }<a name="line.285"></a>
<FONT color="green">286</FONT>    <a name="line.286"></a>
<FONT color="green">287</FONT>        /**<a name="line.287"></a>
<FONT color="green">288</FONT>         * Close all child iterators.<a name="line.288"></a>
<FONT color="green">289</FONT>         */<a name="line.289"></a>
<FONT color="green">290</FONT>        public void close() throws IOException {<a name="line.290"></a>
<FONT color="green">291</FONT>          for (int i = 0; i &lt; iters.length; ++i) {<a name="line.291"></a>
<FONT color="green">292</FONT>            iters[i].close();<a name="line.292"></a>
<FONT color="green">293</FONT>          }<a name="line.293"></a>
<FONT color="green">294</FONT>        }<a name="line.294"></a>
<FONT color="green">295</FONT>    <a name="line.295"></a>
<FONT color="green">296</FONT>        /**<a name="line.296"></a>
<FONT color="green">297</FONT>         * Write the next value into key, value as accepted by the operation<a name="line.297"></a>
<FONT color="green">298</FONT>         * associated with this set of RecordReaders.<a name="line.298"></a>
<FONT color="green">299</FONT>         */<a name="line.299"></a>
<FONT color="green">300</FONT>        public boolean flush(TupleWritable value) throws IOException {<a name="line.300"></a>
<FONT color="green">301</FONT>          while (hasNext()) {<a name="line.301"></a>
<FONT color="green">302</FONT>            value.clearWritten();<a name="line.302"></a>
<FONT color="green">303</FONT>            if (next(value) &amp;&amp; combine(kids, value)) {<a name="line.303"></a>
<FONT color="green">304</FONT>              return true;<a name="line.304"></a>
<FONT color="green">305</FONT>            }<a name="line.305"></a>
<FONT color="green">306</FONT>          }<a name="line.306"></a>
<FONT color="green">307</FONT>          return false;<a name="line.307"></a>
<FONT color="green">308</FONT>        }<a name="line.308"></a>
<FONT color="green">309</FONT>      }<a name="line.309"></a>
<FONT color="green">310</FONT>    <a name="line.310"></a>
<FONT color="green">311</FONT>      /**<a name="line.311"></a>
<FONT color="green">312</FONT>       * Return the key for the current join or the value at the top of the<a name="line.312"></a>
<FONT color="green">313</FONT>       * RecordReader heap.<a name="line.313"></a>
<FONT color="green">314</FONT>       */<a name="line.314"></a>
<FONT color="green">315</FONT>      public K key() {<a name="line.315"></a>
<FONT color="green">316</FONT>        if (jc.hasNext()) {<a name="line.316"></a>
<FONT color="green">317</FONT>          return jc.key();<a name="line.317"></a>
<FONT color="green">318</FONT>        }<a name="line.318"></a>
<FONT color="green">319</FONT>        if (!q.isEmpty()) {<a name="line.319"></a>
<FONT color="green">320</FONT>          return q.peek().key();<a name="line.320"></a>
<FONT color="green">321</FONT>        }<a name="line.321"></a>
<FONT color="green">322</FONT>        return null;<a name="line.322"></a>
<FONT color="green">323</FONT>      }<a name="line.323"></a>
<FONT color="green">324</FONT>    <a name="line.324"></a>
<FONT color="green">325</FONT>      /**<a name="line.325"></a>
<FONT color="green">326</FONT>       * Clone the key at the top of this RR into the given object.<a name="line.326"></a>
<FONT color="green">327</FONT>       */<a name="line.327"></a>
<FONT color="green">328</FONT>      public void key(K key) throws IOException {<a name="line.328"></a>
<FONT color="green">329</FONT>        WritableUtils.cloneInto(key, key());<a name="line.329"></a>
<FONT color="green">330</FONT>      }<a name="line.330"></a>
<FONT color="green">331</FONT>    <a name="line.331"></a>
<FONT color="green">332</FONT>      /**<a name="line.332"></a>
<FONT color="green">333</FONT>       * Return true if it is possible that this could emit more values.<a name="line.333"></a>
<FONT color="green">334</FONT>       */<a name="line.334"></a>
<FONT color="green">335</FONT>      public boolean hasNext() {<a name="line.335"></a>
<FONT color="green">336</FONT>        return jc.hasNext() || !q.isEmpty();<a name="line.336"></a>
<FONT color="green">337</FONT>      }<a name="line.337"></a>
<FONT color="green">338</FONT>    <a name="line.338"></a>
<FONT color="green">339</FONT>      /**<a name="line.339"></a>
<FONT color="green">340</FONT>       * Pass skip key to child RRs.<a name="line.340"></a>
<FONT color="green">341</FONT>       */<a name="line.341"></a>
<FONT color="green">342</FONT>      public void skip(K key) throws IOException {<a name="line.342"></a>
<FONT color="green">343</FONT>        ArrayList&lt;ComposableRecordReader&lt;K,?&gt;&gt; tmp =<a name="line.343"></a>
<FONT color="green">344</FONT>          new ArrayList&lt;ComposableRecordReader&lt;K,?&gt;&gt;();<a name="line.344"></a>
<FONT color="green">345</FONT>        while (!q.isEmpty() &amp;&amp; cmp.compare(q.peek().key(), key) &lt;= 0) {<a name="line.345"></a>
<FONT color="green">346</FONT>          tmp.add(q.poll());<a name="line.346"></a>
<FONT color="green">347</FONT>        }<a name="line.347"></a>
<FONT color="green">348</FONT>        for (ComposableRecordReader&lt;K,?&gt; rr : tmp) {<a name="line.348"></a>
<FONT color="green">349</FONT>          rr.skip(key);<a name="line.349"></a>
<FONT color="green">350</FONT>          if (rr.hasNext()) {<a name="line.350"></a>
<FONT color="green">351</FONT>            q.add(rr);<a name="line.351"></a>
<FONT color="green">352</FONT>          }<a name="line.352"></a>
<FONT color="green">353</FONT>        }<a name="line.353"></a>
<FONT color="green">354</FONT>      }<a name="line.354"></a>
<FONT color="green">355</FONT>    <a name="line.355"></a>
<FONT color="green">356</FONT>      /**<a name="line.356"></a>
<FONT color="green">357</FONT>       * Obtain an iterator over the child RRs apropos of the value type<a name="line.357"></a>
<FONT color="green">358</FONT>       * ultimately emitted from this join.<a name="line.358"></a>
<FONT color="green">359</FONT>       */<a name="line.359"></a>
<FONT color="green">360</FONT>      protected abstract ResetableIterator&lt;X&gt; getDelegate();<a name="line.360"></a>
<FONT color="green">361</FONT>    <a name="line.361"></a>
<FONT color="green">362</FONT>      /**<a name="line.362"></a>
<FONT color="green">363</FONT>       * If key provided matches that of this Composite, give JoinCollector<a name="line.363"></a>
<FONT color="green">364</FONT>       * iterator over values it may emit.<a name="line.364"></a>
<FONT color="green">365</FONT>       */<a name="line.365"></a>
<FONT color="green">366</FONT>      @SuppressWarnings("unchecked") // No values from static EMPTY class<a name="line.366"></a>
<FONT color="green">367</FONT>      public void accept(CompositeRecordReader.JoinCollector jc, K key)<a name="line.367"></a>
<FONT color="green">368</FONT>          throws IOException {<a name="line.368"></a>
<FONT color="green">369</FONT>        if (hasNext() &amp;&amp; 0 == cmp.compare(key, key())) {<a name="line.369"></a>
<FONT color="green">370</FONT>          fillJoinCollector(createKey());<a name="line.370"></a>
<FONT color="green">371</FONT>          jc.add(id, getDelegate());<a name="line.371"></a>
<FONT color="green">372</FONT>          return;<a name="line.372"></a>
<FONT color="green">373</FONT>        }<a name="line.373"></a>
<FONT color="green">374</FONT>        jc.add(id, EMPTY);<a name="line.374"></a>
<FONT color="green">375</FONT>      }<a name="line.375"></a>
<FONT color="green">376</FONT>    <a name="line.376"></a>
<FONT color="green">377</FONT>      /**<a name="line.377"></a>
<FONT color="green">378</FONT>       * For all child RRs offering the key provided, obtain an iterator<a name="line.378"></a>
<FONT color="green">379</FONT>       * at that position in the JoinCollector.<a name="line.379"></a>
<FONT color="green">380</FONT>       */<a name="line.380"></a>
<FONT color="green">381</FONT>      protected void fillJoinCollector(K iterkey) throws IOException {<a name="line.381"></a>
<FONT color="green">382</FONT>        if (!q.isEmpty()) {<a name="line.382"></a>
<FONT color="green">383</FONT>          q.peek().key(iterkey);<a name="line.383"></a>
<FONT color="green">384</FONT>          while (0 == cmp.compare(q.peek().key(), iterkey)) {<a name="line.384"></a>
<FONT color="green">385</FONT>            ComposableRecordReader&lt;K,?&gt; t = q.poll();<a name="line.385"></a>
<FONT color="green">386</FONT>            t.accept(jc, iterkey);<a name="line.386"></a>
<FONT color="green">387</FONT>            if (t.hasNext()) {<a name="line.387"></a>
<FONT color="green">388</FONT>              q.add(t);<a name="line.388"></a>
<FONT color="green">389</FONT>            } else if (q.isEmpty()) {<a name="line.389"></a>
<FONT color="green">390</FONT>              return;<a name="line.390"></a>
<FONT color="green">391</FONT>            }<a name="line.391"></a>
<FONT color="green">392</FONT>          }<a name="line.392"></a>
<FONT color="green">393</FONT>        }<a name="line.393"></a>
<FONT color="green">394</FONT>      }<a name="line.394"></a>
<FONT color="green">395</FONT>    <a name="line.395"></a>
<FONT color="green">396</FONT>      /**<a name="line.396"></a>
<FONT color="green">397</FONT>       * Implement Comparable contract (compare key of join or head of heap<a name="line.397"></a>
<FONT color="green">398</FONT>       * with that of another).<a name="line.398"></a>
<FONT color="green">399</FONT>       */<a name="line.399"></a>
<FONT color="green">400</FONT>      public int compareTo(ComposableRecordReader&lt;K,?&gt; other) {<a name="line.400"></a>
<FONT color="green">401</FONT>        return cmp.compare(key(), other.key());<a name="line.401"></a>
<FONT color="green">402</FONT>      }<a name="line.402"></a>
<FONT color="green">403</FONT>    <a name="line.403"></a>
<FONT color="green">404</FONT>      /**<a name="line.404"></a>
<FONT color="green">405</FONT>       * Create a new key value common to all child RRs.<a name="line.405"></a>
<FONT color="green">406</FONT>       * @throws ClassCastException if key classes differ.<a name="line.406"></a>
<FONT color="green">407</FONT>       */<a name="line.407"></a>
<FONT color="green">408</FONT>      @SuppressWarnings("unchecked") // Explicit check for key class agreement<a name="line.408"></a>
<FONT color="green">409</FONT>      public K createKey() {<a name="line.409"></a>
<FONT color="green">410</FONT>        if (null == keyclass) {<a name="line.410"></a>
<FONT color="green">411</FONT>          final Class&lt;?&gt; cls = kids[0].createKey().getClass();<a name="line.411"></a>
<FONT color="green">412</FONT>          for (RecordReader&lt;K,? extends Writable&gt; rr : kids) {<a name="line.412"></a>
<FONT color="green">413</FONT>            if (!cls.equals(rr.createKey().getClass())) {<a name="line.413"></a>
<FONT color="green">414</FONT>              throw new ClassCastException("Child key classes fail to agree");<a name="line.414"></a>
<FONT color="green">415</FONT>            }<a name="line.415"></a>
<FONT color="green">416</FONT>          }<a name="line.416"></a>
<FONT color="green">417</FONT>          keyclass = cls.asSubclass(WritableComparable.class);<a name="line.417"></a>
<FONT color="green">418</FONT>        }<a name="line.418"></a>
<FONT color="green">419</FONT>        return (K) ReflectionUtils.newInstance(keyclass, getConf());<a name="line.419"></a>
<FONT color="green">420</FONT>      }<a name="line.420"></a>
<FONT color="green">421</FONT>    <a name="line.421"></a>
<FONT color="green">422</FONT>      /**<a name="line.422"></a>
<FONT color="green">423</FONT>       * Create a value to be used internally for joins.<a name="line.423"></a>
<FONT color="green">424</FONT>       */<a name="line.424"></a>
<FONT color="green">425</FONT>      protected TupleWritable createInternalValue() {<a name="line.425"></a>
<FONT color="green">426</FONT>        Writable[] vals = new Writable[kids.length];<a name="line.426"></a>
<FONT color="green">427</FONT>        for (int i = 0; i &lt; vals.length; ++i) {<a name="line.427"></a>
<FONT color="green">428</FONT>          vals[i] = kids[i].createValue();<a name="line.428"></a>
<FONT color="green">429</FONT>        }<a name="line.429"></a>
<FONT color="green">430</FONT>        return new TupleWritable(vals);<a name="line.430"></a>
<FONT color="green">431</FONT>      }<a name="line.431"></a>
<FONT color="green">432</FONT>    <a name="line.432"></a>
<FONT color="green">433</FONT>      /**<a name="line.433"></a>
<FONT color="green">434</FONT>       * Unsupported (returns zero in all cases).<a name="line.434"></a>
<FONT color="green">435</FONT>       */<a name="line.435"></a>
<FONT color="green">436</FONT>      public long getPos() throws IOException {<a name="line.436"></a>
<FONT color="green">437</FONT>        return 0;<a name="line.437"></a>
<FONT color="green">438</FONT>      }<a name="line.438"></a>
<FONT color="green">439</FONT>    <a name="line.439"></a>
<FONT color="green">440</FONT>      /**<a name="line.440"></a>
<FONT color="green">441</FONT>       * Close all child RRs.<a name="line.441"></a>
<FONT color="green">442</FONT>       */<a name="line.442"></a>
<FONT color="green">443</FONT>      public void close() throws IOException {<a name="line.443"></a>
<FONT color="green">444</FONT>        if (kids != null) {<a name="line.444"></a>
<FONT color="green">445</FONT>          for (RecordReader&lt;K,? extends Writable&gt; rr : kids) {<a name="line.445"></a>
<FONT color="green">446</FONT>            rr.close();<a name="line.446"></a>
<FONT color="green">447</FONT>          }<a name="line.447"></a>
<FONT color="green">448</FONT>        }<a name="line.448"></a>
<FONT color="green">449</FONT>        if (jc != null) {<a name="line.449"></a>
<FONT color="green">450</FONT>          jc.close();<a name="line.450"></a>
<FONT color="green">451</FONT>        }<a name="line.451"></a>
<FONT color="green">452</FONT>      }<a name="line.452"></a>
<FONT color="green">453</FONT>    <a name="line.453"></a>
<FONT color="green">454</FONT>      /**<a name="line.454"></a>
<FONT color="green">455</FONT>       * Report progress as the minimum of all child RR progress.<a name="line.455"></a>
<FONT color="green">456</FONT>       */<a name="line.456"></a>
<FONT color="green">457</FONT>      public float getProgress() throws IOException {<a name="line.457"></a>
<FONT color="green">458</FONT>        float ret = 1.0f;<a name="line.458"></a>
<FONT color="green">459</FONT>        for (RecordReader&lt;K,? extends Writable&gt; rr : kids) {<a name="line.459"></a>
<FONT color="green">460</FONT>          ret = Math.min(ret, rr.getProgress());<a name="line.460"></a>
<FONT color="green">461</FONT>        }<a name="line.461"></a>
<FONT color="green">462</FONT>        return ret;<a name="line.462"></a>
<FONT color="green">463</FONT>      }<a name="line.463"></a>
<FONT color="green">464</FONT>    }<a name="line.464"></a>




























































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