1<!--$Id: callback.so,v 1.5 2000/10/26 15:20:40 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB Reference Guide: Release 3.2: DB callback functions, app_private field</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<table width="100%"><tr valign=top> 12<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></b></td> 13<td align=right><a href="../upgrade.3.2/set_flags.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.3.2/renumber.html"><img src="../../images/next.gif" alt="Next"></a> 14</td></tr></table> 15<p align=center><b>Release 3.2: DB callback functions, app_private field</b></p> 16<p>In the Berkeley DB 3.2 release, four application callback functions (the 17callback functions set by <a href="../../api_c/db_set_bt_compare.html">DB->set_bt_compare</a>, 18<a href="../../api_c/db_set_bt_prefix.html">DB->set_bt_prefix</a>, <a href="../../api_c/db_set_dup_compare.html">DB->set_dup_compare</a> and 19<a href="../../api_c/db_set_h_hash.html">DB->set_h_hash</a>) were modified to take a reference to a 20<a href="../../api_c/db_class.html">DB</a> object as their first argument. This change allows the Berkeley DB 21Java API to reasonably support these interfaces. There is currently no 22need for the callback functions to do anything with this additional 23argument.</p> 24<p>C and C++ applications that specify their own Btree key comparison, 25Btree prefix comparison, duplicate data item comparison or Hash 26functions should modify these functions to take a reference to a 27<a href="../../api_c/db_class.html">DB</a> structure as their first argument. No further change is 28required.</p> 29<p>The app_private field of the <a href="../../api_c/dbt_class.html">DBT</a> structure (accessible only from 30the Berkeley DB C API) has been removed in the 3.2 release. It was replaced 31with app_private fields in the <a href="../../api_c/env_class.html">DB_ENV</a> and <a href="../../api_c/db_class.html">DB</a> handles. 32Applications using this field will have to convert to using one of the 33replacement fields.</p> 34<table width="100%"><tr><td><br></td><td align=right><a href="../upgrade.3.2/set_flags.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.3.2/renumber.html"><img src="../../images/next.gif" alt="Next"></a> 35</td></tr></table> 36<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 37</body> 38</html> 39
