mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
224 lines
8.3 KiB
HTML
224 lines
8.3 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>DbMultipleDataBuilder</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="dbt.html" title="Chapter 4. The Dbt Handle" />
|
||
<link rel="prev" href="dbmultiplebuilder.html" title="DbMultipleBuilder" />
|
||
<link rel="next" href="dbmultiplekeydatabuilder.html" title="DbMultipleKeyDataBuilder" />
|
||
</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">DbMultipleDataBuilder</th>
|
||
</tr>
|
||
<tr>
|
||
<td width="20%" align="left"><a accesskey="p" href="dbmultiplebuilder.html">Prev</a> </td>
|
||
<th width="60%" align="center">Chapter 4.
|
||
The Dbt Handle
|
||
</th>
|
||
<td width="20%" align="right"> <a accesskey="n" href="dbmultiplekeydatabuilder.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="dbmultipledatabuilder"></a>DbMultipleDataBuilder</h2>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<pre class="programlisting">#include <db_cxx.h>
|
||
|
||
class DbMultipleDataBuilder
|
||
{
|
||
public:
|
||
DbMultipleDataBuilder(Dbt &dbt);
|
||
|
||
bool append(void *dbuf, size_t dlen);
|
||
bool reserve(void *&ddest, size_t dlen);
|
||
}; </pre>
|
||
<p>
|
||
This class builds a bulk buffer for use when the
|
||
<a class="link" href="dbput.html#put_DB_MULTIPLE">DB_MULTIPLE</a>
|
||
flag is specified to either the
|
||
<a class="xref" href="dbput.html" title="Db::put()">Db::put()</a> or
|
||
<a class="xref" href="dbdel.html" title="Db::del()">Db::del()</a> methods. The buffer in
|
||
the <a class="link" href="dbt.html" title="Chapter 4. The Dbt Handle">Dbt</a> passed to the constructor is
|
||
filled by calls to
|
||
<a class="xref" href="dbmultipledatabuilder.html#dbmultipledatabuilder.append" title="DbMultipleDataBuilder.append()">DbMultipleDataBuilder.append()</a>
|
||
or
|
||
<a class="xref" href="dbmultipledatabuilder.html#dbmultipledatabuilder.reserve" title="DbMultipleDataBuilder.reserve()">DbMultipleDataBuilder.reserve()</a>.
|
||
</p>
|
||
<p>
|
||
The constructor takes a <a class="xref" href="dbt.html" title="Chapter 4. The Dbt Handle">
|
||
The Dbt Handle
|
||
</a>
|
||
that must be configured to contain a buffer managed by the application,
|
||
with the <code class="literal">ulen</code> field set to the size of the buffer.
|
||
</p>
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
All instances of the bulk retrieval classes may be used only once,
|
||
and to build the bulk buffer in the forward direction only.
|
||
</p>
|
||
</div>
|
||
<p>
|
||
Parameters are:
|
||
</p>
|
||
<div class="itemizedlist">
|
||
<ul type="disc">
|
||
<li>
|
||
<p>
|
||
<code class="literal">dbt</code>
|
||
</p>
|
||
<p>
|
||
The <span class="bold"><strong>dbt</strong></span> parameter is a <a class="xref" href="dbt.html" title="Chapter 4. The Dbt Handle">
|
||
The Dbt Handle
|
||
</a> that must already be configured to contain a buffer managed by the application, with the <code class="literal">ulen</code> field set to the size of the buffer, which must be a multiple of 4.
|
||
</p>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
<div class="sect2" lang="en" xml:lang="en">
|
||
<div class="titlepage">
|
||
<div>
|
||
<div>
|
||
<h3 class="title"><a id="dbmultipledatabuilder.append"></a>DbMultipleDataBuilder.append()</h3>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<p>
|
||
The <code class="methodname">DbMultipleDataBuilder.append()</code> method
|
||
copies a data item to the end of the buffer.
|
||
</p>
|
||
<p>
|
||
The <code class="methodname">DbMultipleDataBuilder.append()</code>
|
||
method returns <code class="literal">false</code> if the data does not fit
|
||
in the buffer and <code class="literal">true</code> otherwise.
|
||
</p>
|
||
<p>
|
||
Parameters are:
|
||
</p>
|
||
<div class="itemizedlist">
|
||
<ul type="disc">
|
||
<li>
|
||
<p>
|
||
<code class="literal">dbuf</code>
|
||
</p>
|
||
<p>
|
||
A pointer to the data to be copied into the bulk buffer.
|
||
</p>
|
||
</li>
|
||
<li>
|
||
<p>
|
||
<code class="literal">dlen</code>
|
||
</p>
|
||
<p>
|
||
The number of bytes to be copied.
|
||
</p>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
<div class="sect2" lang="en" xml:lang="en">
|
||
<div class="titlepage">
|
||
<div>
|
||
<div>
|
||
<h3 class="title"><a id="dbmultipledatabuilder.reserve"></a>DbMultipleDataBuilder.reserve()</h3>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<p>
|
||
The <code class="methodname">DbMultipleDataBuilder.reserve()</code>
|
||
method reserves space for the next data item in the bulk buffer.
|
||
Unlike the <code class="methodname">append()</code>, no data is actually
|
||
copied into the bulk buffer by <code class="methodname">reserve()</code>:
|
||
copying the data is the responsibility of the application.
|
||
</p>
|
||
<p>
|
||
The <code class="methodname">DbMultipleDataBuilder.reserve()</code>
|
||
method returns <code class="literal">false</code> if the data does
|
||
not fit in the buffer and <code class="literal">true</code> otherwise.
|
||
</p>
|
||
<p>
|
||
Parameters are:
|
||
</p>
|
||
<div class="itemizedlist">
|
||
<ul type="disc">
|
||
<li>
|
||
<p>
|
||
<code class="literal">ddest</code>
|
||
</p>
|
||
<p>
|
||
Set to a pointer to the position in the bulk buffer reserved for the data item, if enough space is available.
|
||
</p>
|
||
</li>
|
||
<li>
|
||
<p>
|
||
<code class="literal">dlen</code>
|
||
</p>
|
||
<p>
|
||
The number of bytes to reserve.
|
||
</p>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
<div class="sect2" lang="en" xml:lang="en">
|
||
<div class="titlepage">
|
||
<div>
|
||
<div>
|
||
<h3 class="title"><a id="id3610721"></a>Class</h3>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<p>
|
||
<a class="link" href="dbt.html" title="Chapter 4. The Dbt Handle">Dbt</a>
|
||
</p>
|
||
</div>
|
||
<div class="sect2" lang="en" xml:lang="en">
|
||
<div class="titlepage">
|
||
<div>
|
||
<div>
|
||
<h3 class="title"><a id="id3610182"></a>See Also</h3>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<p>
|
||
<a class="xref" href="dbt.html#dbtlist" title="DBT and Bulk Operations">DBT and Bulk Operations</a>
|
||
</p>
|
||
</div>
|
||
</div>
|
||
<div class="navfooter">
|
||
<hr />
|
||
<table width="100%" summary="Navigation footer">
|
||
<tr>
|
||
<td width="40%" align="left"><a accesskey="p" href="dbmultiplebuilder.html">Prev</a> </td>
|
||
<td width="20%" align="center">
|
||
<a accesskey="u" href="dbt.html">Up</a>
|
||
</td>
|
||
<td width="40%" align="right"> <a accesskey="n" href="dbmultiplekeydatabuilder.html">Next</a></td>
|
||
</tr>
|
||
<tr>
|
||
<td width="40%" align="left" valign="top">DbMultipleBuilder </td>
|
||
<td width="20%" align="center">
|
||
<a accesskey="h" href="index.html">Home</a>
|
||
</td>
|
||
<td width="40%" align="right" valign="top"> DbMultipleKeyDataBuilder</td>
|
||
</tr>
|
||
</table>
|
||
</div>
|
||
</body>
|
||
</html>
|