1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>DB_ENV->set_feedback()</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C API Reference" /> 10 <link rel="up" href="env.html" title="Chapter��5.�� The DB_ENV Handle" /> 11 <link rel="prev" href="envset_errpfx.html" title="DB_ENV->set_errpfx()" /> 12 <link rel="next" href="envset_flags.html" title="DB_ENV->set_flags()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DB_ENV->set_feedback()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="envset_errpfx.html">Prev</a>��</td> 22 <th width="60%" align="center">Chapter��5.�� 23 The DB_ENV Handle 24 </th> 25 <td width="20%" align="right">��<a accesskey="n" href="envset_flags.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="sect1" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title" style="clear: both"><a id="envset_feedback"></a>DB_ENV->set_feedback()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db.h> 39 40int 41DB_ENV->set_feedback(DB_ENV *dbenv, 42 void (*db_feedback_fcn)(DB_ENV *dbenv, int opcode, int percent)); </pre> 43 <p> 44 Some operations performed by the Berkeley DB library can take 45 non-trivial amounts of time. The <code class="methodname">DB_ENV->set_feedback()</code> method can 46 be used by applications to monitor progress within these operations. 47 When an operation is likely to take a long time, Berkeley DB will call 48 the specified callback function with progress information. 49 </p> 50 <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> 51 <h3 class="title">Note</h3> 52 <p> 53 Berkeley DB is not re-entrant. Callback functions should not attempt to make library calls (for 54 example, to release locks or close open handles). Re-entering Berkeley DB is not guaranteed to work 55 correctly, and the results are undefined. 56 </p> 57 </div> 58 <p> 59 It is up to the callback function to display this information in an 60 appropriate manner. 61 </p> 62 <p> 63 The <code class="methodname">DB_ENV->set_feedback()</code> method configures operations performed 64 using the specified <a class="link" href="env.html" title="Chapter��5.�� The DB_ENV Handle">DB_ENV</a> handle. 65 </p> 66 <p> 67 The <code class="methodname">DB_ENV->set_feedback()</code> method may be called at any time during 68 the life of the application. 69 </p> 70 <p> 71 The <code class="methodname">DB_ENV->set_feedback()</code> method returns a non-zero error value on 72 failure and 0 on success. 73 </p> 74 <div class="sect2" lang="en" xml:lang="en"> 75 <div class="titlepage"> 76 <div> 77 <div> 78 <h3 class="title"><a id="id1669110"></a>Parameters</h3> 79 </div> 80 </div> 81 </div> 82 <div class="sect3" lang="en" xml:lang="en"> 83 <div class="titlepage"> 84 <div> 85 <div> 86 <h4 class="title"><a id="id1669034"></a>db_feedback_fcn</h4> 87 </div> 88 </div> 89 </div> 90 <p> 91 The <span class="bold"><strong>db_feedback_fcn</strong></span> parameter is the 92 application-specified feedback function called to report Berkeley DB 93 operation progress. The callback function must take three parameters: 94 </p> 95 <div class="itemizedlist"> 96 <ul type="disc"> 97 <li> 98 <p> 99 <code class="literal">dbenv</code> 100 </p> 101 <p> 102 The <span class="bold"><strong>dbenv</strong></span> parameter is a reference to 103 the enclosing database environment. 104 </p> 105 </li> 106 <li> 107 <p> 108 <code class="literal">opcode</code> 109 </p> 110 <p> 111 The <span class="bold"><strong>opcode</strong></span> parameter is an operation 112 code. The <span class="bold"><strong>opcode</strong></span> parameter may take 113 on any of the following values: 114 </p> 115 <div class="itemizedlist"> 116 <ul type="circle"> 117 <li> 118 <p><a id="set_feedback_DB_RECOVER"></a> 119 <code class="literal">DB_RECOVER</code> 120 </p> 121 <p> 122 The environment is being recovered. 123 </p> 124 </li> 125 </ul> 126 </div> 127 </li> 128 <li> 129 <p> 130 <code class="literal">percent</code> 131 </p> 132 <p> 133 The <span class="bold"><strong>percent</strong></span> parameter is the percent 134 of the operation that has been completed, specified as an integer 135 value between 0 and 100. 136 </p> 137 </li> 138 </ul> 139 </div> 140 </div> 141 </div> 142 <div class="sect2" lang="en" xml:lang="en"> 143 <div class="titlepage"> 144 <div> 145 <div> 146 <h3 class="title"><a id="id1669273"></a>Class</h3> 147 </div> 148 </div> 149 </div> 150 <p> 151 <a class="link" href="env.html" title="Chapter��5.�� The DB_ENV Handle">DB_ENV</a> 152 </p> 153 </div> 154 <div class="sect2" lang="en" xml:lang="en"> 155 <div class="titlepage"> 156 <div> 157 <div> 158 <h3 class="title"><a id="id1669385"></a>See Also</h3> 159 </div> 160 </div> 161 </div> 162 <p> 163 <a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a> 164 </p> 165 </div> 166 </div> 167 <div class="navfooter"> 168 <hr /> 169 <table width="100%" summary="Navigation footer"> 170 <tr> 171 <td width="40%" align="left"><a accesskey="p" href="envset_errpfx.html">Prev</a>��</td> 172 <td width="20%" align="center"> 173 <a accesskey="u" href="env.html">Up</a> 174 </td> 175 <td width="40%" align="right">��<a accesskey="n" href="envset_flags.html">Next</a></td> 176 </tr> 177 <tr> 178 <td width="40%" align="left" valign="top">DB_ENV->set_errpfx()��</td> 179 <td width="20%" align="center"> 180 <a accesskey="h" href="index.html">Home</a> 181 </td> 182 <td width="40%" align="right" valign="top">��DB_ENV->set_flags()</td> 183 </tr> 184 </table> 185 </div> 186 </body> 187</html> 188