<?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>DbMultipleRecnoDataBuilder</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="dbmultiplekeydatabuilder.html" title="DbMultipleKeyDataBuilder" /> <link rel="next" href="env.html" title="Chapter 5. The DbEnv Handle" /> </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">DbMultipleRecnoDataBuilder</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="dbmultiplekeydatabuilder.html">Prev</a> </td> <th width="60%" align="center">Chapter 4. The Dbt Handle </th> <td width="20%" align="right"> <a accesskey="n" href="env.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="dbmultiplerecnodatabuilder"></a>DbMultipleRecnoDataBuilder</h2></div></div></div><pre class="programlisting">#include <db_cxx.h> class DbMultipleRecnoDataBuilder { public: DbMultipleRecnoDataBuilder(Dbt &dbt); bool append(db_recno_t recno, void *dbuf, size_t dlen); bool reserve(db_recno_t recno, 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_KEY">DB_MULTIPLE_KEY</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 with the recno or queue access methods, or for the <code class="literal">key</code> when the <a class="link" href="dbput.html#put_DB_MULTIPLE">DB_MULTIPLE</a> flag is used. 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="dbmultiplerecnodatabuilder.html#dbmultiplerecnodatabuilder.append" title="DbMultipleRecnoDataBuilder.append()">DbMultipleRecnoDataBuilder.append()</a> or <a class="xref" href="dbmultiplerecnodatabuilder.html#dbmultiplerecnodatabuilder.reserve" title="DbMultipleRecnoDataBuilder.reserve()">DbMultipleRecnoDataBuilder.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> bool append(db_recno_t recno, void *dbuf, size_t dlen); <div class="sect2" lang="en" xml:lang="en"><div class="titlepage"><div><div><h3 class="title"><a id="dbmultiplerecnodatabuilder.append"></a>DbMultipleRecnoDataBuilder.append()</h3></div></div></div><p> The <code class="methodname">DbMultipleRecnoDataBuilder.append()</code> method copies a record number / data pair to the end of the buffer. </p><p> The <code class="methodname">DbMultipleRecnoDataBuilder.append()</code> method returns <code class="literal">false</code> if the record number / data pair 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">recno</code> </p><p> The record number to append. </p></li><li><p> <code class="literal">dbuf</code> </p><p> A pointer to the data item to be copied into the bulk buffer. </p></li><li><p> <code class="literal">dlen</code> </p><p> The number of bytes of the data item 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="dbmultiplerecnodatabuilder.reserve"></a>DbMultipleRecnoDataBuilder.reserve()</h3></div></div></div><p> The <code class="methodname">DbMultipleRecnoDataBuilder.reserve()</code> method reserves space for the next record number / data pair in the bulk buffer. The record number is appended, but unlike the <code class="methodname">append()</code>, the data is not 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">DbMultipleRecnoDataBuilder.reserve()</code> method returns <code class="literal">false</code> if the record 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">recno</code> </p><p> The record number to append. </p></li><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 for the data item. </p></li></ul></div></div><div class="sect2" lang="en" xml:lang="en"><div class="titlepage"><div><div><h3 class="title"><a id="idp6554296"></a>Class</h3></div></div></div><p> <a class="link" href="dbmultiplebuilder.html" title="DbMultipleBuilder">DbMultipleBuilder</a> </p></div><div class="sect2" lang="en" xml:lang="en"><div class="titlepage"><div><div><h3 class="title"><a id="idp6564664"></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="dbmultiplekeydatabuilder.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="env.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">DbMultipleKeyDataBuilder </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Chapter 5. 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