<?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_env_set_func_ioinfo</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="setfunc.html" title="Appendix C. Berkeley DB Application Space Static Functions" /> <link rel="prev" href="db_env_set_func_ftruncate.html" title="db_env_set_func_ftruncate" /> <link rel="next" href="db_env_set_func_malloc.html" title="db_env_set_func_malloc" /> </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_env_set_func_ioinfo</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="db_env_set_func_ftruncate.html">Prev</a> </td> <th width="60%" align="center">Appendix C. Berkeley DB Application Space Static Functions </th> <td width="20%" align="right"> <a accesskey="n" href="db_env_set_func_malloc.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="db_env_set_func_ioinfo"></a>db_env_set_func_ioinfo</h2> </div> </div> </div> <pre class="programlisting">#include <db.h> int db_env_set_func_ioinfo(int (*func_ioinfo)(const char *path, int fd, u_int32_t *mbytesp, u_int32_t *bytesp, u_int32_t *iosizep)); </pre> <p> The Berkeley DB library requires the ability to determine the size and I/O characteristics of a file. </p> <p> The <code class="function">db_env_set_func_ioinfo()</code> function configures all operations performed by a process and all of its threads of control, not operations confined to a single database environment. </p> <p> Although the <code class="function">db_env_set_func_ioinfo()</code> function may be called at any time during the life of the application, it should normally be called before making calls to the <a class="xref" href="envcreate.html" title="db_env_create">db_env_create</a> or <a class="xref" href="dbcreate.html" title="db_create">db_create</a> methods. </p> <p> The <code class="function">db_env_set_func_ioinfo()</code> <span> function returns a non-zero error value on failure and 0 on success. </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp55638192"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp55638384"></a>func_ioinfo</h4> </div> </div> </div> <p> The <span class="bold"><strong>func_ioinfo</strong></span> parameter is the function which returns the size and I/O characteristics of a file. </p> <p> The <span class="bold"><strong>path</strong></span> parameter is the pathname of the file to be checked, and the <span class="bold"><strong>fd</strong></span> parameter is an open file descriptor on the file. </p> <p> If the <span class="bold"><strong>mbytesp</strong></span> and <span class="bold"><strong>bytesp</strong></span> parameters are non-NULL, the <span class="bold"><strong>ioinfo</strong></span> function must return in them the size of the file: the number of megabytes in the file into the memory location to which the <span class="bold"><strong>mbytesp</strong></span> parameter refers, and the number of bytes over and above that number of megabytes into the memory location to which the <span class="bold"><strong>bytesp</strong></span> parameter refers. </p> <p> In addition, if the <span class="bold"><strong>iosizep</strong></span> parameter is non-NULL, the <span class="bold"><strong>ioinfo</strong></span> function must return the optimum granularity for I/O operations to the file into the memory location to which it refers. </p> <p> The <span class="bold"><strong>func_ioinfo</strong></span> function must return the value of <span class="bold"><strong>errno</strong></span> on failure and 0 on success. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp55632920"></a>See Also</h3> </div> </div> </div> <p> <a href="../../programmer_reference/program_runtime.html" class="olink">Run-time configuration</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="db_env_set_func_ftruncate.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="setfunc.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="db_env_set_func_malloc.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">db_env_set_func_ftruncate </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> db_env_set_func_malloc</td> </tr> </table> </div> </body> </html>