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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.mapreduce.lib.db;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    import java.sql.ResultSet;<a name="line.21"></a>
<FONT color="green">022</FONT>    import java.sql.SQLException;<a name="line.22"></a>
<FONT color="green">023</FONT>    import java.util.ArrayList;<a name="line.23"></a>
<FONT color="green">024</FONT>    import java.util.List;<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>    import org.apache.commons.logging.Log;<a name="line.26"></a>
<FONT color="green">027</FONT>    import org.apache.commons.logging.LogFactory;<a name="line.27"></a>
<FONT color="green">028</FONT>    <a name="line.28"></a>
<FONT color="green">029</FONT>    import org.apache.hadoop.classification.InterfaceAudience;<a name="line.29"></a>
<FONT color="green">030</FONT>    import org.apache.hadoop.classification.InterfaceStability;<a name="line.30"></a>
<FONT color="green">031</FONT>    import org.apache.hadoop.conf.Configuration;<a name="line.31"></a>
<FONT color="green">032</FONT>    import org.apache.hadoop.mapreduce.InputSplit;<a name="line.32"></a>
<FONT color="green">033</FONT>    import org.apache.hadoop.mapreduce.MRJobConfig;<a name="line.33"></a>
<FONT color="green">034</FONT>    <a name="line.34"></a>
<FONT color="green">035</FONT>    /**<a name="line.35"></a>
<FONT color="green">036</FONT>     * Implement DBSplitter over floating-point values.<a name="line.36"></a>
<FONT color="green">037</FONT>     */<a name="line.37"></a>
<FONT color="green">038</FONT>    @InterfaceAudience.Public<a name="line.38"></a>
<FONT color="green">039</FONT>    @InterfaceStability.Evolving<a name="line.39"></a>
<FONT color="green">040</FONT>    public class FloatSplitter implements DBSplitter {<a name="line.40"></a>
<FONT color="green">041</FONT>    <a name="line.41"></a>
<FONT color="green">042</FONT>      private static final Log LOG = LogFactory.getLog(FloatSplitter.class);<a name="line.42"></a>
<FONT color="green">043</FONT>    <a name="line.43"></a>
<FONT color="green">044</FONT>      private static final double MIN_INCREMENT = 10000 * Double.MIN_VALUE;<a name="line.44"></a>
<FONT color="green">045</FONT>    <a name="line.45"></a>
<FONT color="green">046</FONT>      public List&lt;InputSplit&gt; split(Configuration conf, ResultSet results, String colName)<a name="line.46"></a>
<FONT color="green">047</FONT>          throws SQLException {<a name="line.47"></a>
<FONT color="green">048</FONT>    <a name="line.48"></a>
<FONT color="green">049</FONT>        LOG.warn("Generating splits for a floating-point index column. Due to the");<a name="line.49"></a>
<FONT color="green">050</FONT>        LOG.warn("imprecise representation of floating-point values in Java, this");<a name="line.50"></a>
<FONT color="green">051</FONT>        LOG.warn("may result in an incomplete import.");<a name="line.51"></a>
<FONT color="green">052</FONT>        LOG.warn("You are strongly encouraged to choose an integral split column.");<a name="line.52"></a>
<FONT color="green">053</FONT>    <a name="line.53"></a>
<FONT color="green">054</FONT>        List&lt;InputSplit&gt; splits = new ArrayList&lt;InputSplit&gt;();<a name="line.54"></a>
<FONT color="green">055</FONT>    <a name="line.55"></a>
<FONT color="green">056</FONT>        if (results.getString(1) == null &amp;&amp; results.getString(2) == null) {<a name="line.56"></a>
<FONT color="green">057</FONT>          // Range is null to null. Return a null split accordingly.<a name="line.57"></a>
<FONT color="green">058</FONT>          splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(<a name="line.58"></a>
<FONT color="green">059</FONT>              colName + " IS NULL", colName + " IS NULL"));<a name="line.59"></a>
<FONT color="green">060</FONT>          return splits;<a name="line.60"></a>
<FONT color="green">061</FONT>        }<a name="line.61"></a>
<FONT color="green">062</FONT>    <a name="line.62"></a>
<FONT color="green">063</FONT>        double minVal = results.getDouble(1);<a name="line.63"></a>
<FONT color="green">064</FONT>        double maxVal = results.getDouble(2);<a name="line.64"></a>
<FONT color="green">065</FONT>    <a name="line.65"></a>
<FONT color="green">066</FONT>        // Use this as a hint. May need an extra task if the size doesn't<a name="line.66"></a>
<FONT color="green">067</FONT>        // divide cleanly.<a name="line.67"></a>
<FONT color="green">068</FONT>        int numSplits = conf.getInt(MRJobConfig.NUM_MAPS, 1);<a name="line.68"></a>
<FONT color="green">069</FONT>        double splitSize = (maxVal - minVal) / (double) numSplits;<a name="line.69"></a>
<FONT color="green">070</FONT>    <a name="line.70"></a>
<FONT color="green">071</FONT>        if (splitSize &lt; MIN_INCREMENT) {<a name="line.71"></a>
<FONT color="green">072</FONT>          splitSize = MIN_INCREMENT;<a name="line.72"></a>
<FONT color="green">073</FONT>        }<a name="line.73"></a>
<FONT color="green">074</FONT>    <a name="line.74"></a>
<FONT color="green">075</FONT>        String lowClausePrefix = colName + " &gt;= ";<a name="line.75"></a>
<FONT color="green">076</FONT>        String highClausePrefix = colName + " &lt; ";<a name="line.76"></a>
<FONT color="green">077</FONT>    <a name="line.77"></a>
<FONT color="green">078</FONT>        double curLower = minVal;<a name="line.78"></a>
<FONT color="green">079</FONT>        double curUpper = curLower + splitSize;<a name="line.79"></a>
<FONT color="green">080</FONT>    <a name="line.80"></a>
<FONT color="green">081</FONT>        while (curUpper &lt; maxVal) {<a name="line.81"></a>
<FONT color="green">082</FONT>          splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(<a name="line.82"></a>
<FONT color="green">083</FONT>              lowClausePrefix + Double.toString(curLower),<a name="line.83"></a>
<FONT color="green">084</FONT>              highClausePrefix + Double.toString(curUpper)));<a name="line.84"></a>
<FONT color="green">085</FONT>    <a name="line.85"></a>
<FONT color="green">086</FONT>          curLower = curUpper;<a name="line.86"></a>
<FONT color="green">087</FONT>          curUpper += splitSize;<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>        // Catch any overage and create the closed interval for the last split.<a name="line.90"></a>
<FONT color="green">091</FONT>        if (curLower &lt;= maxVal || splits.size() == 1) {<a name="line.91"></a>
<FONT color="green">092</FONT>          splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(<a name="line.92"></a>
<FONT color="green">093</FONT>              lowClausePrefix + Double.toString(curUpper),<a name="line.93"></a>
<FONT color="green">094</FONT>              colName + " &lt;= " + Double.toString(maxVal)));<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>        if (results.getString(1) == null || results.getString(2) == null) {<a name="line.97"></a>
<FONT color="green">098</FONT>          // At least one extrema is null; add a null split.<a name="line.98"></a>
<FONT color="green">099</FONT>          splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(<a name="line.99"></a>
<FONT color="green">100</FONT>              colName + " IS NULL", colName + " IS NULL"));<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>        return splits;<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>




























































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