<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>DbMpoolFile::get_fileid()</title> <link rel="stylesheet" href="apiReference.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" /> <link rel="up" href="memp.html" title="Chapter 9. The DbMpoolFile Handle" /> <link rel="prev" href="mempget_clear_len.html" title="DbMpoolFile::get_clear_len()" /> <link rel="next" href="mempget_flags.html" title="DbMpoolFile::get_flags()" /> </head> <body> <div xmlns="" class="navheader"> <div class="libver"> <p>Library Version 11.2.5.3</p> </div> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">DbMpoolFile::get_fileid()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="mempget_clear_len.html">Prev</a> </td> <th width="60%" align="center">Chapter 9. The DbMpoolFile Handle </th> <td width="20%" align="right"> <a accesskey="n" href="mempget_flags.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="mempget_fileid"></a>DbMpoolFile::get_fileid()</h2> </div> </div> </div> <pre class="programlisting">#include <db_cxx.h> int DbMpoolFile::get_fileid(u_int8_t *fileid);</pre> <p> The <code class="methodname">DbMpoolFile::get_fileid()</code> method copies the file's identifier into the memory location referenced by <span class="bold"><strong>fileid</strong></span>. The fileid specifies a unique identifier for the file, which is used so that the cache functions (that is, the shared memory buffer pool functions) are able to uniquely identify files. This is necessary for multiple processes wanting to share a file to correctly identify the file in the cache. </p> <p> The <code class="methodname">DbMpoolFile::get_fileid()</code> <span> <span> method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8973520"></a>Class</h3> </div> </div> </div> <p> <a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>, <a class="link" href="memp.html" title="Chapter 9. The DbMpoolFile Handle">DbMpoolFile</a> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp8974600"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="memp.html#memplist" title="Memory Pools and Related Methods">Memory Pools and Related Methods</a>, <a class="xref" href="mempset_fileid.html" title="DbMpoolFile::set_fileid()">DbMpoolFile::set_fileid()</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="mempget_clear_len.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="memp.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="mempget_flags.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">DbMpoolFile::get_clear_len() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> DbMpoolFile::get_flags()</td> </tr> </table> </div> </body> </html>