| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <!-- NewPage --> |
| <html lang="en"> |
| <head> |
| <!-- Generated by javadoc (1.8.0_292) on Tue Jun 15 06:00:54 GMT 2021 --> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <title>ValueAggregatorDescriptor (Apache Hadoop Main 3.3.1 API)</title> |
| <meta name="date" content="2021-06-15"> |
| <link rel="stylesheet" type="text/css" href="../../../../../../stylesheet.css" title="Style"> |
| <script type="text/javascript" src="../../../../../../script.js"></script> |
| </head> |
| <body> |
| <script type="text/javascript"><!-- |
| try { |
| if (location.href.indexOf('is-external=true') == -1) { |
| parent.document.title="ValueAggregatorDescriptor (Apache Hadoop Main 3.3.1 API)"; |
| } |
| } |
| catch(err) { |
| } |
| //--> |
| var methods = {"i0":6,"i1":6}; |
| var tabs = {65535:["t0","All Methods"],2:["t2","Instance Methods"],4:["t3","Abstract Methods"]}; |
| var altColor = "altColor"; |
| var rowColor = "rowColor"; |
| var tableTab = "tableTab"; |
| var activeTableTab = "activeTableTab"; |
| </script> |
| <noscript> |
| <div>JavaScript is disabled on your browser.</div> |
| </noscript> |
| <!-- ========= START OF TOP NAVBAR ======= --> |
| <div class="topNav"><a name="navbar.top"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.top" title="Skip navigation links">Skip navigation links</a></div> |
| <a name="navbar.top.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../../../../overview-summary.html">Overview</a></li> |
| <li><a href="package-summary.html">Package</a></li> |
| <li class="navBarCell1Rev">Class</li> |
| <li><a href="class-use/ValueAggregatorDescriptor.html">Use</a></li> |
| <li><a href="package-tree.html">Tree</a></li> |
| <li><a href="../../../../../../deprecated-list.html">Deprecated</a></li> |
| <li><a href="../../../../../../index-all.html">Index</a></li> |
| <li><a href="../../../../../../help-doc.html">Help</a></li> |
| </ul> |
| </div> |
| <div class="subNav"> |
| <ul class="navList"> |
| <li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorCombiner.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate"><span class="typeNameLink">Prev Class</span></a></li> |
| <li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorJob.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate"><span class="typeNameLink">Next Class</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../../../index.html?org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html" target="_top">Frames</a></li> |
| <li><a href="ValueAggregatorDescriptor.html" target="_top">No Frames</a></li> |
| </ul> |
| <ul class="navList" id="allclasses_navbar_top"> |
| <li><a href="../../../../../../allclasses-noframe.html">All Classes</a></li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_top"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>Summary: </li> |
| <li>Nested | </li> |
| <li><a href="#field.summary">Field</a> | </li> |
| <li>Constr | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li><a href="#field.detail">Field</a> | </li> |
| <li>Constr | </li> |
| <li><a href="#method.detail">Method</a></li> |
| </ul> |
| </div> |
| <a name="skip.navbar.top"> |
| <!-- --> |
| </a></div> |
| <!-- ========= END OF TOP NAVBAR ========= --> |
| <!-- ======== START OF CLASS DATA ======== --> |
| <div class="header"> |
| <div class="subTitle">org.apache.hadoop.mapreduce.lib.aggregate</div> |
| <h2 title="Interface ValueAggregatorDescriptor" class="title">Interface ValueAggregatorDescriptor</h2> |
| </div> |
| <div class="contentContainer"> |
| <div class="description"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <dl> |
| <dt>All Known Subinterfaces:</dt> |
| <dd><a href="../../../../../../org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html" title="interface in org.apache.hadoop.mapred.lib.aggregate">ValueAggregatorDescriptor</a></dd> |
| </dl> |
| <dl> |
| <dt>All Known Implementing Classes:</dt> |
| <dd><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/UserDefinedValueAggregatorDescriptor.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate">UserDefinedValueAggregatorDescriptor</a>, <a href="../../../../../../org/apache/hadoop/mapred/lib/aggregate/UserDefinedValueAggregatorDescriptor.html" title="class in org.apache.hadoop.mapred.lib.aggregate">UserDefinedValueAggregatorDescriptor</a>, <a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorBaseDescriptor.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorBaseDescriptor</a>, <a href="../../../../../../org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorBaseDescriptor.html" title="class in org.apache.hadoop.mapred.lib.aggregate">ValueAggregatorBaseDescriptor</a></dd> |
| </dl> |
| <hr> |
| <br> |
| <pre>@InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public interface <span class="typeNameLabel">ValueAggregatorDescriptor</span></pre> |
| <div class="block">This interface defines the contract a value aggregator descriptor must |
| support. Such a descriptor can be configured with a <a href="../../../../../../org/apache/hadoop/conf/Configuration.html" title="class in org.apache.hadoop.conf"><code>Configuration</code></a> |
| object. Its main function is to generate a list of aggregation-id/value |
| pairs. An aggregation id encodes an aggregation type which is used to |
| guide the way to aggregate the value in the reduce/combiner phrase of an |
| Aggregate based job. |
| The mapper in an Aggregate based map/reduce job may create one or more of |
| ValueAggregatorDescriptor objects at configuration time. For each input |
| key/value pair, the mapper will use those objects to create aggregation |
| id/value pairs.</div> |
| </li> |
| </ul> |
| </div> |
| <div class="summary"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- =========== FIELD SUMMARY =========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="field.summary"> |
| <!-- --> |
| </a> |
| <h3>Field Summary</h3> |
| <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Field Summary table, listing fields, and an explanation"> |
| <caption><span>Fields</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Field and Description</th> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><code>static <a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#ONE">ONE</a></span></code> </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><code>static <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/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#TYPE_SEPARATOR">TYPE_SEPARATOR</a></span></code> </td> |
| </tr> |
| </table> |
| </li> |
| </ul> |
| <!-- ========== METHOD SUMMARY =========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="method.summary"> |
| <!-- --> |
| </a> |
| <h3>Method Summary</h3> |
| <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation"> |
| <caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd"> </span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd"> </span></span><span id="t3" class="tableTab"><span><a href="javascript:show(4);">Abstract Methods</a></span><span class="tabEnd"> </span></span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Method and Description</th> |
| </tr> |
| <tr id="i0" class="altColor"> |
| <td class="colFirst"><code>void</code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#configure-org.apache.hadoop.conf.Configuration-">configure</a></span>(<a href="../../../../../../org/apache/hadoop/conf/Configuration.html" title="class in org.apache.hadoop.conf">Configuration</a> conf)</code> |
| <div class="block">Configure the object</div> |
| </td> |
| </tr> |
| <tr id="i1" class="rowColor"> |
| <td class="colFirst"><code><a href="https://docs.oracle.com/javase/8/docs/api/java/util/ArrayList.html?is-external=true" title="class or interface in java.util">ArrayList</a><<a href="https://docs.oracle.com/javase/8/docs/api/java/util/Map.Entry.html?is-external=true" title="class or interface in java.util">Map.Entry</a><<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>>></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#generateKeyValPairs-java.lang.Object-java.lang.Object-">generateKeyValPairs</a></span>(<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> key, |
| <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> val)</code> |
| <div class="block">Generate a list of aggregation-id/value pairs for |
| the given key/value pair.</div> |
| </td> |
| </tr> |
| </table> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| <div class="details"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ============ FIELD DETAIL =========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="field.detail"> |
| <!-- --> |
| </a> |
| <h3>Field Detail</h3> |
| <a name="TYPE_SEPARATOR"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>TYPE_SEPARATOR</h4> |
| <pre>static final <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> TYPE_SEPARATOR</pre> |
| <dl> |
| <dt><span class="seeLabel">See Also:</span></dt> |
| <dd><a href="../../../../../../constant-values.html#org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorDescriptor.TYPE_SEPARATOR">Constant Field Values</a></dd> |
| </dl> |
| </li> |
| </ul> |
| <a name="ONE"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>ONE</h4> |
| <pre>static final <a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a> ONE</pre> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| <!-- ============ METHOD DETAIL ========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="method.detail"> |
| <!-- --> |
| </a> |
| <h3>Method Detail</h3> |
| <a name="generateKeyValPairs-java.lang.Object-java.lang.Object-"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>generateKeyValPairs</h4> |
| <pre><a href="https://docs.oracle.com/javase/8/docs/api/java/util/ArrayList.html?is-external=true" title="class or interface in java.util">ArrayList</a><<a href="https://docs.oracle.com/javase/8/docs/api/java/util/Map.Entry.html?is-external=true" title="class or interface in java.util">Map.Entry</a><<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>>> generateKeyValPairs(<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> key, |
| <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> val)</pre> |
| <div class="block">Generate a list of aggregation-id/value pairs for |
| the given key/value pair. |
| This function is usually called by the mapper of an Aggregate based job.</div> |
| <dl> |
| <dt><span class="paramLabel">Parameters:</span></dt> |
| <dd><code>key</code> - input key</dd> |
| <dd><code>val</code> - input value</dd> |
| <dt><span class="returnLabel">Returns:</span></dt> |
| <dd>a list of aggregation id/value pairs. An aggregation id encodes an |
| aggregation type which is used to guide the way to aggregate the |
| value in the reduce/combiner phrase of an Aggregate based job.</dd> |
| </dl> |
| </li> |
| </ul> |
| <a name="configure-org.apache.hadoop.conf.Configuration-"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>configure</h4> |
| <pre>void configure(<a href="../../../../../../org/apache/hadoop/conf/Configuration.html" title="class in org.apache.hadoop.conf">Configuration</a> conf)</pre> |
| <div class="block">Configure the object</div> |
| <dl> |
| <dt><span class="paramLabel">Parameters:</span></dt> |
| <dd><code>conf</code> - a Configuration object that may contain the information |
| that can be used to configure the object.</dd> |
| </dl> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| </div> |
| <!-- ========= END OF CLASS DATA ========= --> |
| <!-- ======= START OF BOTTOM NAVBAR ====== --> |
| <div class="bottomNav"><a name="navbar.bottom"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.bottom" title="Skip navigation links">Skip navigation links</a></div> |
| <a name="navbar.bottom.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../../../../overview-summary.html">Overview</a></li> |
| <li><a href="package-summary.html">Package</a></li> |
| <li class="navBarCell1Rev">Class</li> |
| <li><a href="class-use/ValueAggregatorDescriptor.html">Use</a></li> |
| <li><a href="package-tree.html">Tree</a></li> |
| <li><a href="../../../../../../deprecated-list.html">Deprecated</a></li> |
| <li><a href="../../../../../../index-all.html">Index</a></li> |
| <li><a href="../../../../../../help-doc.html">Help</a></li> |
| </ul> |
| </div> |
| <div class="subNav"> |
| <ul class="navList"> |
| <li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorCombiner.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate"><span class="typeNameLink">Prev Class</span></a></li> |
| <li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorJob.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate"><span class="typeNameLink">Next Class</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../../../index.html?org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html" target="_top">Frames</a></li> |
| <li><a href="ValueAggregatorDescriptor.html" target="_top">No Frames</a></li> |
| </ul> |
| <ul class="navList" id="allclasses_navbar_bottom"> |
| <li><a href="../../../../../../allclasses-noframe.html">All Classes</a></li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_bottom"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>Summary: </li> |
| <li>Nested | </li> |
| <li><a href="#field.summary">Field</a> | </li> |
| <li>Constr | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li><a href="#field.detail">Field</a> | </li> |
| <li>Constr | </li> |
| <li><a href="#method.detail">Method</a></li> |
| </ul> |
| </div> |
| <a name="skip.navbar.bottom"> |
| <!-- --> |
| </a></div> |
| <!-- ======== END OF BOTTOM NAVBAR ======= --> |
| <p class="legalCopy"><small>Copyright © 2021 <a href="https://www.apache.org">Apache Software Foundation</a>. All rights reserved.</small></p> |
| </body> |
| </html> |