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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.PriorityQueue;<a name="line.22"></a>
<FONT color="green">023</FONT>    <a name="line.23"></a>
<FONT color="green">024</FONT>    import org.apache.hadoop.classification.InterfaceAudience;<a name="line.24"></a>
<FONT color="green">025</FONT>    import org.apache.hadoop.classification.InterfaceStability;<a name="line.25"></a>
<FONT color="green">026</FONT>    import org.apache.hadoop.io.Writable;<a name="line.26"></a>
<FONT color="green">027</FONT>    import org.apache.hadoop.io.WritableComparable;<a name="line.27"></a>
<FONT color="green">028</FONT>    import org.apache.hadoop.io.WritableComparator;<a name="line.28"></a>
<FONT color="green">029</FONT>    import org.apache.hadoop.io.WritableUtils;<a name="line.29"></a>
<FONT color="green">030</FONT>    import org.apache.hadoop.util.ReflectionUtils;<a name="line.30"></a>
<FONT color="green">031</FONT>    import org.apache.hadoop.mapred.JobConf;<a name="line.31"></a>
<FONT color="green">032</FONT>    import org.apache.hadoop.mapred.RecordReader;<a name="line.32"></a>
<FONT color="green">033</FONT>    <a name="line.33"></a>
<FONT color="green">034</FONT>    /**<a name="line.34"></a>
<FONT color="green">035</FONT>     * Base class for Composite join returning values derived from multiple<a name="line.35"></a>
<FONT color="green">036</FONT>     * sources, but generally not tuples.<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.Stable<a name="line.39"></a>
<FONT color="green">040</FONT>    public abstract class MultiFilterRecordReader&lt;K extends WritableComparable,<a name="line.40"></a>
<FONT color="green">041</FONT>                                                  V extends Writable&gt;<a name="line.41"></a>
<FONT color="green">042</FONT>        extends CompositeRecordReader&lt;K,V,V&gt;<a name="line.42"></a>
<FONT color="green">043</FONT>        implements ComposableRecordReader&lt;K,V&gt; {<a name="line.43"></a>
<FONT color="green">044</FONT>    <a name="line.44"></a>
<FONT color="green">045</FONT>      private Class&lt;? extends Writable&gt; valueclass;<a name="line.45"></a>
<FONT color="green">046</FONT>      private TupleWritable ivalue;<a name="line.46"></a>
<FONT color="green">047</FONT>    <a name="line.47"></a>
<FONT color="green">048</FONT>      public MultiFilterRecordReader(int id, JobConf conf, int capacity,<a name="line.48"></a>
<FONT color="green">049</FONT>          Class&lt;? extends WritableComparator&gt; cmpcl) throws IOException {<a name="line.49"></a>
<FONT color="green">050</FONT>        super(id, capacity, cmpcl);<a name="line.50"></a>
<FONT color="green">051</FONT>        setConf(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>      /**<a name="line.54"></a>
<FONT color="green">055</FONT>       * For each tuple emitted, return a value (typically one of the values<a name="line.55"></a>
<FONT color="green">056</FONT>       * in the tuple).<a name="line.56"></a>
<FONT color="green">057</FONT>       * Modifying the Writables in the tuple is permitted and unlikely to affect<a name="line.57"></a>
<FONT color="green">058</FONT>       * join behavior in most cases, but it is not recommended. It's safer to<a name="line.58"></a>
<FONT color="green">059</FONT>       * clone first.<a name="line.59"></a>
<FONT color="green">060</FONT>       */<a name="line.60"></a>
<FONT color="green">061</FONT>      protected abstract V emit(TupleWritable dst) throws IOException;<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>       * Default implementation offers {@link #emit} every Tuple from the<a name="line.64"></a>
<FONT color="green">065</FONT>       * collector (the outer join of child RRs).<a name="line.65"></a>
<FONT color="green">066</FONT>       */<a name="line.66"></a>
<FONT color="green">067</FONT>      protected boolean combine(Object[] srcs, TupleWritable dst) {<a name="line.67"></a>
<FONT color="green">068</FONT>        return true;<a name="line.68"></a>
<FONT color="green">069</FONT>      }<a name="line.69"></a>
<FONT color="green">070</FONT>    <a name="line.70"></a>
<FONT color="green">071</FONT>      /** {@inheritDoc} */<a name="line.71"></a>
<FONT color="green">072</FONT>      public boolean next(K key, V value) throws IOException {<a name="line.72"></a>
<FONT color="green">073</FONT>        if (jc.flush(ivalue)) {<a name="line.73"></a>
<FONT color="green">074</FONT>          WritableUtils.cloneInto(key, jc.key());<a name="line.74"></a>
<FONT color="green">075</FONT>          WritableUtils.cloneInto(value, emit(ivalue));<a name="line.75"></a>
<FONT color="green">076</FONT>          return true;<a name="line.76"></a>
<FONT color="green">077</FONT>        }<a name="line.77"></a>
<FONT color="green">078</FONT>        jc.clear();<a name="line.78"></a>
<FONT color="green">079</FONT>        K iterkey = createKey();<a name="line.79"></a>
<FONT color="green">080</FONT>        final PriorityQueue&lt;ComposableRecordReader&lt;K,?&gt;&gt; q = getRecordReaderQueue();<a name="line.80"></a>
<FONT color="green">081</FONT>        while (!q.isEmpty()) {<a name="line.81"></a>
<FONT color="green">082</FONT>          fillJoinCollector(iterkey);<a name="line.82"></a>
<FONT color="green">083</FONT>          jc.reset(iterkey);<a name="line.83"></a>
<FONT color="green">084</FONT>          if (jc.flush(ivalue)) {<a name="line.84"></a>
<FONT color="green">085</FONT>            WritableUtils.cloneInto(key, jc.key());<a name="line.85"></a>
<FONT color="green">086</FONT>            WritableUtils.cloneInto(value, emit(ivalue));<a name="line.86"></a>
<FONT color="green">087</FONT>            return true;<a name="line.87"></a>
<FONT color="green">088</FONT>          }<a name="line.88"></a>
<FONT color="green">089</FONT>          jc.clear();<a name="line.89"></a>
<FONT color="green">090</FONT>        }<a name="line.90"></a>
<FONT color="green">091</FONT>        return false;<a name="line.91"></a>
<FONT color="green">092</FONT>      }<a name="line.92"></a>
<FONT color="green">093</FONT>    <a name="line.93"></a>
<FONT color="green">094</FONT>      /** {@inheritDoc} */<a name="line.94"></a>
<FONT color="green">095</FONT>      @SuppressWarnings("unchecked") // Explicit check for value class agreement<a name="line.95"></a>
<FONT color="green">096</FONT>      public V createValue() {<a name="line.96"></a>
<FONT color="green">097</FONT>        if (null == valueclass) {<a name="line.97"></a>
<FONT color="green">098</FONT>          final Class&lt;?&gt; cls = kids[0].createValue().getClass();<a name="line.98"></a>
<FONT color="green">099</FONT>          for (RecordReader&lt;K,? extends V&gt; rr : kids) {<a name="line.99"></a>
<FONT color="green">100</FONT>            if (!cls.equals(rr.createValue().getClass())) {<a name="line.100"></a>
<FONT color="green">101</FONT>              throw new ClassCastException("Child value classes fail to agree");<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>          valueclass = cls.asSubclass(Writable.class);<a name="line.104"></a>
<FONT color="green">105</FONT>          ivalue = createInternalValue();<a name="line.105"></a>
<FONT color="green">106</FONT>        }<a name="line.106"></a>
<FONT color="green">107</FONT>        return (V) ReflectionUtils.newInstance(valueclass, null);<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 an iterator returning a single value from the tuple.<a name="line.111"></a>
<FONT color="green">112</FONT>       * @see MultiFilterDelegationIterator<a name="line.112"></a>
<FONT color="green">113</FONT>       */<a name="line.113"></a>
<FONT color="green">114</FONT>      protected ResetableIterator&lt;V&gt; getDelegate() {<a name="line.114"></a>
<FONT color="green">115</FONT>        return new MultiFilterDelegationIterator();<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>      /**<a name="line.118"></a>
<FONT color="green">119</FONT>       * Proxy the JoinCollector, but include callback to emit.<a name="line.119"></a>
<FONT color="green">120</FONT>       */<a name="line.120"></a>
<FONT color="green">121</FONT>      protected class MultiFilterDelegationIterator<a name="line.121"></a>
<FONT color="green">122</FONT>          implements ResetableIterator&lt;V&gt; {<a name="line.122"></a>
<FONT color="green">123</FONT>    <a name="line.123"></a>
<FONT color="green">124</FONT>        public boolean hasNext() {<a name="line.124"></a>
<FONT color="green">125</FONT>          return jc.hasNext();<a name="line.125"></a>
<FONT color="green">126</FONT>        }<a name="line.126"></a>
<FONT color="green">127</FONT>    <a name="line.127"></a>
<FONT color="green">128</FONT>        public boolean next(V val) throws IOException {<a name="line.128"></a>
<FONT color="green">129</FONT>          boolean ret;<a name="line.129"></a>
<FONT color="green">130</FONT>          if (ret = jc.flush(ivalue)) {<a name="line.130"></a>
<FONT color="green">131</FONT>            WritableUtils.cloneInto(val, emit(ivalue));<a name="line.131"></a>
<FONT color="green">132</FONT>          }<a name="line.132"></a>
<FONT color="green">133</FONT>          return ret;<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>        public boolean replay(V val) throws IOException {<a name="line.136"></a>
<FONT color="green">137</FONT>          WritableUtils.cloneInto(val, emit(ivalue));<a name="line.137"></a>
<FONT color="green">138</FONT>          return true;<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>        public void reset() {<a name="line.141"></a>
<FONT color="green">142</FONT>          jc.reset(jc.key());<a name="line.142"></a>
<FONT color="green">143</FONT>        }<a name="line.143"></a>
<FONT color="green">144</FONT>    <a name="line.144"></a>
<FONT color="green">145</FONT>        public void add(V item) throws IOException {<a name="line.145"></a>
<FONT color="green">146</FONT>          throw new UnsupportedOperationException();<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>        public void close() throws IOException {<a name="line.149"></a>
<FONT color="green">150</FONT>          jc.close();<a name="line.150"></a>
<FONT color="green">151</FONT>        }<a name="line.151"></a>
<FONT color="green">152</FONT>    <a name="line.152"></a>
<FONT color="green">153</FONT>        public void clear() {<a name="line.153"></a>
<FONT color="green">154</FONT>          jc.clear();<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>
<FONT color="green">157</FONT>    <a name="line.157"></a>
<FONT color="green">158</FONT>    }<a name="line.158"></a>




























































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