<?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>Db::set_feedback()</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="db.html" title="Chapter 2. The Db Handle" /> <link rel="prev" href="dbset_errpfx.html" title="Db::set_errpfx()" /> <link rel="next" href="dbset_flags.html" title="Db::set_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">Db::set_feedback()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="dbset_errpfx.html">Prev</a> </td> <th width="60%" align="center">Chapter 2. The Db Handle </th> <td width="20%" align="right"> <a accesskey="n" href="dbset_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="dbset_feedback"></a>Db::set_feedback()</h2> </div> </div> </div> <pre class="programlisting">#include <db_cxx.h> int Db::set_feedback(void (*db_feedback_fcn)(DB *dbp, int opcode, int percent));</pre> <p> Some operations performed by the Berkeley DB library can take non-trivial amounts of time. The <code class="methodname">Db::set_feedback()</code> method can be used by applications to monitor progress within these operations. When an operation is likely to take a long time, Berkeley DB will call the specified callback function with progress information. </p> <p> It is up to the callback function to display this information in an appropriate manner. </p> <p> The <code class="methodname">Db::set_feedback()</code> method may be called at any time during the life of the application. </p> <p> The <code class="methodname">Db::set_feedback()</code> method returns a non-zero error value on failure and 0 on success. </p> <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> <h3 class="title">Note</h3> <p> Berkeley DB is not re-entrant. Callback functions should not attempt to make library calls (for example, to release locks or close open handles). Re-entering Berkeley DB is not guaranteed to work correctly, and the results are undefined. </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp396360"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp73568"></a>db_feedback_fcn</h4> </div> </div> </div> <p> The <span class="bold"><strong>db_feedback_fcn</strong></span> parameter is the application-specified feedback function called to report Berkeley DB operation progress. The callback function must take three parameters: </p> <div class="itemizedlist"> <ul type="disc"> <li> <p> <code class="literal">dbp</code> </p> <p> The <span class="bold"><strong>dbp</strong></span> parameter is a reference to the enclosing database. </p> </li> <li> <p> <code class="literal">opcode</code> </p> <p> The <span class="bold"><strong>opcode</strong></span> parameter is an operation code. The <span class="bold"><strong>opcode</strong></span> parameter may take on any of the following values: </p> <div class="itemizedlist"> <ul type="circle"> <li> <p><a id="set_feedback_DB_UPGRADE"></a> <code class="literal">DB_UPGRADE</code> </p> <p> The underlying database is being upgraded. </p> </li> <li> <p><a id="set_feedback_DB_VERIFY"></a> <code class="literal">DB_VERIFY</code> </p> <p> The underlying database is being verified. </p> </li> </ul> </div> </li> <li> <p> <code class="literal">percent</code> </p> <p> The <span class="bold"><strong>percent</strong></span> parameter is the percent of the operation that has been completed, specified as an integer value between 0 and 100. </p> </li> </ul> </div> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idm1983360"></a>Class</h3> </div> </div> </div> <p> <a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idm1227552"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="dbset_errpfx.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="db.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="dbset_flags.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Db::set_errpfx() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Db::set_flags()</td> </tr> </table> </div> </body> </html>