| <!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_121) on Fri Apr 14 22:11:35 PDT 2017 --> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <title>IDMigrator (Mahout Map-Reduce 0.13.0 API)</title> |
| <meta name="date" content="2017-04-14"> |
| <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="IDMigrator (Mahout Map-Reduce 0.13.0 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/IDMigrator.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/mahout/cf/taste/model/DataModel.html" title="interface in org.apache.mahout.cf.taste.model"><span class="typeNameLink">Prev Class</span></a></li> |
| <li><a href="../../../../../../org/apache/mahout/cf/taste/model/JDBCDataModel.html" title="interface in org.apache.mahout.cf.taste.model"><span class="typeNameLink">Next Class</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../../../index.html?org/apache/mahout/cf/taste/model/IDMigrator.html" target="_top">Frames</a></li> |
| <li><a href="IDMigrator.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>Field | </li> |
| <li>Constr | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li>Field | </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.mahout.cf.taste.model</div> |
| <h2 title="Interface IDMigrator" class="title">Interface IDMigrator</h2> |
| </div> |
| <div class="contentContainer"> |
| <div class="description"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <dl> |
| <dt>All Superinterfaces:</dt> |
| <dd><a href="../../../../../../org/apache/mahout/cf/taste/common/Refreshable.html" title="interface in org.apache.mahout.cf.taste.common">Refreshable</a></dd> |
| </dl> |
| <dl> |
| <dt>All Known Subinterfaces:</dt> |
| <dd><a href="../../../../../../org/apache/mahout/cf/taste/model/UpdatableIDMigrator.html" title="interface in org.apache.mahout.cf.taste.model">UpdatableIDMigrator</a></dd> |
| </dl> |
| <dl> |
| <dt>All Known Implementing Classes:</dt> |
| <dd><a href="../../../../../../org/apache/mahout/cf/taste/impl/model/AbstractIDMigrator.html" title="class in org.apache.mahout.cf.taste.impl.model">AbstractIDMigrator</a>, <a href="../../../../../../org/apache/mahout/cf/taste/impl/model/AbstractJDBCIDMigrator.html" title="class in org.apache.mahout.cf.taste.impl.model">AbstractJDBCIDMigrator</a>, <a href="../../../../../../org/apache/mahout/cf/taste/impl/model/file/FileIDMigrator.html" title="class in org.apache.mahout.cf.taste.impl.model.file">FileIDMigrator</a>, <a href="../../../../../../org/apache/mahout/cf/taste/impl/model/MemoryIDMigrator.html" title="class in org.apache.mahout.cf.taste.impl.model">MemoryIDMigrator</a>, <a href="../../../../../../org/apache/mahout/cf/taste/impl/model/MySQLJDBCIDMigrator.html" title="class in org.apache.mahout.cf.taste.impl.model">MySQLJDBCIDMigrator</a></dd> |
| </dl> |
| <hr> |
| <br> |
| <pre>public interface <span class="typeNameLabel">IDMigrator</span> |
| extends <a href="../../../../../../org/apache/mahout/cf/taste/common/Refreshable.html" title="interface in org.apache.mahout.cf.taste.common">Refreshable</a></pre> |
| <div class="block"><p> |
| Mahout 0.2 changed the framework to operate only in terms of numeric (long) ID values for users and items. |
| This is, obviously, not compatible with applications that used other key types -- most commonly |
| <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang"><code>String</code></a>. Implementation of this class provide support for mapping String to longs and vice versa in |
| order to provide a smoother migration path to applications that must still use strings as IDs. |
| </p> |
| |
| <p> |
| The mapping from strings to 64-bit numeric values is fixed here, to provide a standard implementation that |
| is 'portable' or reproducible outside the framework easily. See <a href="../../../../../../org/apache/mahout/cf/taste/model/IDMigrator.html#toLongID-java.lang.String-"><code>toLongID(String)</code></a>. |
| </p> |
| |
| <p> |
| Because this mapping is deterministically computable, it does not need to be stored. Indeed, subclasses' |
| job is to store the reverse mapping. There are an infinite number of strings but only a fixed number of |
| longs, so, it is possible for two strings to map to the same value. Subclasses do not treat this as an |
| error but rather retain only the most recent mapping, overwriting a previous mapping. The probability of |
| collision in a 64-bit space is quite small, but not zero. However, in the context of a collaborative |
| filtering problem, the consequence of a collision is small, at worst -- perhaps one user receives another |
| recommendations. |
| </p></div> |
| <dl> |
| <dt><span class="simpleTagLabel">Since:</span></dt> |
| <dd>0.2</dd> |
| </dl> |
| </li> |
| </ul> |
| </div> |
| <div class="summary"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ========== 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>long</code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/mahout/cf/taste/model/IDMigrator.html#toLongID-java.lang.String-">toLongID</a></span>(<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a> stringID)</code> </td> |
| </tr> |
| <tr id="i1" class="rowColor"> |
| <td class="colFirst"><code><a href="http://docs.oracle.com/javase/7/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/mahout/cf/taste/model/IDMigrator.html#toStringID-long-">toStringID</a></span>(long longID)</code> </td> |
| </tr> |
| </table> |
| <ul class="blockList"> |
| <li class="blockList"><a name="methods.inherited.from.class.org.apache.mahout.cf.taste.common.Refreshable"> |
| <!-- --> |
| </a> |
| <h3>Methods inherited from interface org.apache.mahout.cf.taste.common.<a href="../../../../../../org/apache/mahout/cf/taste/common/Refreshable.html" title="interface in org.apache.mahout.cf.taste.common">Refreshable</a></h3> |
| <code><a href="../../../../../../org/apache/mahout/cf/taste/common/Refreshable.html#refresh-java.util.Collection-">refresh</a></code></li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| <div class="details"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ============ METHOD DETAIL ========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="method.detail"> |
| <!-- --> |
| </a> |
| <h3>Method Detail</h3> |
| <a name="toLongID-java.lang.String-"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>toLongID</h4> |
| <pre>long toLongID(<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a> stringID)</pre> |
| <dl> |
| <dt><span class="returnLabel">Returns:</span></dt> |
| <dd>the top 8 bytes of the MD5 hash of the bytes of the given <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang"><code>String</code></a>'s UTF-8 encoding as a |
| long.</dd> |
| </dl> |
| </li> |
| </ul> |
| <a name="toStringID-long-"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>toStringID</h4> |
| <pre><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a> toStringID(long longID) |
| throws <a href="../../../../../../org/apache/mahout/cf/taste/common/TasteException.html" title="class in org.apache.mahout.cf.taste.common">TasteException</a></pre> |
| <dl> |
| <dt><span class="returnLabel">Returns:</span></dt> |
| <dd>the string ID most recently associated with the given long ID, or null if doesn't exist</dd> |
| <dt><span class="throwsLabel">Throws:</span></dt> |
| <dd><code><a href="../../../../../../org/apache/mahout/cf/taste/common/TasteException.html" title="class in org.apache.mahout.cf.taste.common">TasteException</a></code> - if an error occurs while retrieving the mapping</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/IDMigrator.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/mahout/cf/taste/model/DataModel.html" title="interface in org.apache.mahout.cf.taste.model"><span class="typeNameLink">Prev Class</span></a></li> |
| <li><a href="../../../../../../org/apache/mahout/cf/taste/model/JDBCDataModel.html" title="interface in org.apache.mahout.cf.taste.model"><span class="typeNameLink">Next Class</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../../../index.html?org/apache/mahout/cf/taste/model/IDMigrator.html" target="_top">Frames</a></li> |
| <li><a href="IDMigrator.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>Field | </li> |
| <li>Constr | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li>Field | </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 © 2008–2017 <a href="http://www.apache.org/">The Apache Software Foundation</a>. All rights reserved.</small></p> |
| </body> |
| </html> |
