mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
229 lines
9.4 KiB
HTML
229 lines
9.4 KiB
HTML
|
<?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_append_recno()</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_alloc.html" title="Db::set_alloc()" />
|
|||
|
|
<link rel="next" href="dbset_bt_compare.html" title="Db::set_bt_compare()" />
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<div xmlns="" class="navheader">
|
|||
|
|
<div class="libver">
|
|||
|
|
<p>Library Version 11.2.5.2</p>
|
|||
|
|
</div>
|
|||
|
|
<table width="100%" summary="Navigation header">
|
|||
|
|
<tr>
|
|||
|
|
<th colspan="3" align="center">Db::set_append_recno()</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="dbset_alloc.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_bt_compare.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_append_recno"></a>Db::set_append_recno()</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<pre class="programlisting">#include <db_cxx.h>
|
|||
|
|
|
|||
|
|
int
|
|||
|
|
Db::set_append_recno(int (*db_append_recno_fcn)(DB *dbp, Dbt *data,
|
|||
|
|
db_recno_t recno));</pre>
|
|||
|
|
<p>
|
|||
|
|
When using the <a class="link" href="dbput.html#dbput_DB_APPEND">DB_APPEND</a>
|
|||
|
|
option of the <a class="xref" href="dbput.html" title="Db::put()">Db::put()</a> method, it may be
|
|||
|
|
useful to modify the stored data based on the generated key. If a
|
|||
|
|
callback function is specified using the
|
|||
|
|
<code class="methodname">Db::set_append_recno()</code>
|
|||
|
|
method, it will be called after the record number has been selected,
|
|||
|
|
but before the data has been stored.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">Db::set_append_recno()</code> method configures operations performed
|
|||
|
|
using the specified <a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a>
|
|||
|
|
handle, not all operations performed on the underlying database.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">Db::set_append_recno()</code> method may not be called after the
|
|||
|
|
<a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> method is called.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">Db::set_append_recno()</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="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="id3591128"></a>Parameters</h3>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sect3" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h4 class="title"><a id="id3591120"></a>db_append_recno_fcn</h4>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
The <span class="bold"><strong>db_append_recno_fcn</strong></span> parameter is
|
|||
|
|
a function to call after the record number has been selected but
|
|||
|
|
before the data has been stored into the database. The function takes
|
|||
|
|
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 the enclosing
|
|||
|
|
database handle.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
<code class="literal">data</code>
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <span class="bold"><strong>data</strong></span> parameter is the data
|
|||
|
|
<a class="link" href="dbt.html" title="Chapter 4. The Dbt Handle">Dbt</a> to be stored.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
<code class="literal">recno</code>
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <span class="bold"><strong>recno</strong></span> parameter is the generated
|
|||
|
|
record number.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
</ul>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
The called function may modify the data
|
|||
|
|
<a class="link" href="dbt.html" title="Chapter 4. The Dbt Handle">Dbt</a>. If the function needs to allocate
|
|||
|
|
memory for the <span class="bold"><strong>data</strong></span> field, the
|
|||
|
|
<span class="bold"><strong>flags</strong></span> field of
|
|||
|
|
the returned <a class="link" href="dbt.html" title="Chapter 4. The Dbt Handle">Dbt</a>
|
|||
|
|
should be set to <code class="literal">DB_DBT_APPMALLOC</code>, which indicates that
|
|||
|
|
Berkeley DB should free the memory when it is done with it.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The callback function must return 0 on success and
|
|||
|
|
<span class="bold"><strong>errno</strong></span> or a value outside of
|
|||
|
|
the Berkeley DB error name space on failure.
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h3 class="title"><a id="id3590979"></a>Errors</h3>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">Db::set_append_recno()</code> <span>
|
|||
|
|
|
|||
|
|
<span>
|
|||
|
|
method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
|
|||
|
|
exception, encapsulating one of the following non-zero errors, or return one
|
|||
|
|
of the following non-zero errors:
|
|||
|
|
</span>
|
|||
|
|
</span>
|
|||
|
|
</p>
|
|||
|
|
<div class="sect3" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h4 class="title"><a id="id3591230"></a>EINVAL</h4>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
If the method was called after <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a>
|
|||
|
|
was called; or if an invalid flag value or parameter was specified.
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h3 class="title"><a id="id3591400"></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="id3591293"></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_alloc.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_bt_compare.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">Db::set_alloc() </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="h" href="index.html">Home</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right" valign="top"> Db::set_bt_compare()</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|