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 <div class="subTitle">org.apache.hadoop.mapred.nativetask</div>
 <h2 title="Class Platform" class="title">Class Platform</h2>
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 <pre>@InterfaceAudience.Public
  @InterfaceStability.Evolving
 public abstract class <span class="typeNameLabel">Platform</span>
 extends <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</a></pre>
 <div class="block">Base class for platforms. A platform is a framework running on top of
  MapReduce, like Hadoop, Hive, Pig, Mahout. Each framework defines its
  own key type and value type across a MapReduce job. For each platform,
  we should implement serializers such that we could communicate data with
  native side and native comparators so our native output collectors could
  sort them and write out. We've already provided the <code>HadoopPlatform</code>
  that supports all key types of Hadoop and users could implement their custom
  platform.</div>
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 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colLast" scope="col">Field and Description</th>
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 <tr class="altColor">
 <td class="colFirst"><code>protected <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&gt;</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#keyClassNames">keyClassNames</a></span></code>&nbsp;</td>
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 <td class="colOne"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#Platform--">Platform</a></span>()</code>&nbsp;</td>
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 <td class="colFirst"><code>protected abstract boolean</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#define-java.lang.Class-">define</a></span>(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a>&lt;?&gt;&nbsp;keyComparator)</code>
 <div class="block">whether it's the platform that has defined a custom Java comparator

  NativeTask doesn't support custom Java comparators
  (set with mapreduce.job.output.key.comparator.class)
  but a platform (e.g Pig) could also set that conf and implement native
  comparators so we shouldn't bail out.</div>
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 <td class="colFirst"><code>abstract void</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#init--">init</a></span>()</code>
 <div class="block">initialize a platform, where we should call registerKey</div>
 </td>
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 <td class="colFirst"><code>abstract <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a></code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#name--">name</a></span>()</code>&nbsp;</td>
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 <td class="colFirst"><code>protected void</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#registerKey-java.lang.String-java.lang.Class-">registerKey</a></span>(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;keyClassName,
            <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a>&lt;?&gt;&nbsp;key)</code>
 <div class="block">associate a key class with its serializer and platform</div>
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 <td class="colFirst"><code>protected abstract boolean</code></td>
 <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapred/nativetask/Platform.html#support-java.lang.String-org.apache.hadoop.mapred.nativetask.serde.INativeSerializer-org.apache.hadoop.mapred.JobConf-">support</a></span>(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;keyClassName,
        <a href="../../../../../org/apache/hadoop/mapred/nativetask/serde/INativeSerializer.html" title="interface in org.apache.hadoop.mapred.nativetask.serde">INativeSerializer</a>&lt;?&gt;&nbsp;serializer,
        <a href="../../../../../org/apache/hadoop/mapred/JobConf.html" title="class in org.apache.hadoop.mapred">JobConf</a>&nbsp;job)</code>
 <div class="block">whether a platform supports a specific key should at least satisfy two conditions

  1.</div>
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 <pre>protected&nbsp;<a href="https://docs.oracle.com/javase/8/docs/api/java/util/Set.html?is-external=true" title="class or interface in java.util">Set</a>&lt;<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&gt; keyClassNames</pre>
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 <pre>public abstract&nbsp;void&nbsp;init()
                    throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></pre>
 <div class="block">initialize a platform, where we should call registerKey</div>
 <dl>
 <dt><span class="throwsLabel">Throws:</span></dt>
 <dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code></dd>
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 <pre>public abstract&nbsp;<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;name()</pre>
 <dl>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>name of a Platform, useful for logs and debug</dd>
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 <pre>protected&nbsp;void&nbsp;registerKey(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;keyClassName,
                            <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a>&lt;?&gt;&nbsp;key)
                     throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></pre>
 <div class="block">associate a key class with its serializer and platform</div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>keyClassName</code> - map out key class name</dd>
 <dd><code>key</code> - key serializer class</dd>
 <dt><span class="throwsLabel">Throws:</span></dt>
 <dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code></dd>
 </dl>
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 <pre>protected abstract&nbsp;boolean&nbsp;support(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;keyClassName,
                                    <a href="../../../../../org/apache/hadoop/mapred/nativetask/serde/INativeSerializer.html" title="interface in org.apache.hadoop.mapred.nativetask.serde">INativeSerializer</a>&lt;?&gt;&nbsp;serializer,
                                    <a href="../../../../../org/apache/hadoop/mapred/JobConf.html" title="class in org.apache.hadoop.mapred">JobConf</a>&nbsp;job)</pre>
 <div class="block">whether a platform supports a specific key should at least satisfy two conditions

  1. the key belongs to the platform
  2. the associated serializer must implement <a href="../../../../../org/apache/hadoop/mapred/nativetask/INativeComparable.html" title="interface in org.apache.hadoop.mapred.nativetask"><code>INativeComparable</code></a> interface</div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>keyClassName</code> - map out put key class name</dd>
 <dd><code>serializer</code> - serializer associated with key via registerKey</dd>
 <dd><code>job</code> - job configuration</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>true if the platform has implemented native comparators of the key and
                      false otherwise</dd>
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 <pre>protected abstract&nbsp;boolean&nbsp;define(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a>&lt;?&gt;&nbsp;keyComparator)</pre>
 <div class="block">whether it's the platform that has defined a custom Java comparator

  NativeTask doesn't support custom Java comparators
  (set with mapreduce.job.output.key.comparator.class)
  but a platform (e.g Pig) could also set that conf and implement native
  comparators so we shouldn't bail out.</div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>keyComparator</code> - comparator set with mapreduce.job.output.key.comparator.class</dd>
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