1<!--$Id: db_set_feedback.so,v 10.29 2003/10/19 01:27:11 bostic Exp $--> 2<!--$Id: env_set_feedback.so,v 10.43 2006/05/17 20:47:46 bostic Exp $--> 3<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 4<!--See the file LICENSE for redistribution information.--> 5<html> 6<head> 7<title>Berkeley DB: Db::set_feedback</title> 8<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 9<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 10</head> 11<body bgcolor=white> 12<table width="100%"><tr valign=top> 13<td> 14<b>Db::set_feedback</b> 15</td> 16<td align=right> 17<a href="/api_cxx/api_core.html"><img src="/images/api.gif" alt="API"></a> 18<a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a></td> 19</tr></table> 20<hr size=1 noshade> 21<tt> 22<b><pre> 23#include <db_cxx.h> 24<p> 25int 26Db::set_feedback(void (*db_feedback_fcn)(DB *dbp, int opcode, int percent)); 27</pre></b> 28<hr size=1 noshade> 29<b>Description: Db::set_feedback</b> 30<p>Some operations performed by the Berkeley DB library can take non-trivial 31amounts of time. The Db::set_feedback method can be used by applications 32to monitor progress within these operations. When an operation is 33likely to take a long time, Berkeley DB will call the specified callback 34function with progress information.</p> 35<p>It is up to the callback function to display this information in an 36appropriate manner.</p> 37<p>The Db::set_feedback method may be called at any time during the life of the 38application.</p> 39<p>The Db::set_feedback method 40either returns a non-zero error value 41or throws an exception that encapsulates a non-zero error value on 42failure, and returns 0 on success. 43</p> 44<b>Parameters</b> <br> 45 <b>db_feedback_fcn</b><ul compact><li>The <b>db_feedback_fcn</b> parameter is the application-specified 46feedback function called to report Berkeley DB operation progress. The 47callback function must take three parameters: 48<br> 49<b><b>db</b></b><ul compact><li>The <b>db</b> parameter is a reference to the enclosing database.</ul> 50<b><b>opcode</b></b><ul compact><li>The <b>opcode</b> parameter is an operation code. The <b>opcode</b> 51parameter may take on any of the following values: 52<br> 53<b><a name="DB_UPGRADE">DB_UPGRADE</a></b><ul compact><li>The underlying database is being upgraded.</ul> 54<b><a name="DB_VERIFY">DB_VERIFY</a></b><ul compact><li>The underlying database is being verified.</ul> 55<br></ul> 56<b><b>percent</b></b><ul compact><li>The <b>percent</b> parameter is the percent of the operation that has 57been completed, specified as an integer value between 0 and 100.</ul> 58<br></ul> 59<p>Berkeley DB is not re-entrant. Callback functions should not attempt to make 60library calls (for example, to release locks or close open handles). 61Re-entering Berkeley DB is not guaranteed to work correctly, and the results 62are undefined.</p> 63<br> 64<hr size=1 noshade> 65<br><b>Class</b> 66<a href="/api_cxx/db_class.html">Db</a> 67<br><b>See Also</b> 68<a href="/api_cxx/db_list.html">Databases and Related Methods</a> 69</tt> 70<table width="100%"><tr><td><br></td><td align=right> 71<a href="/api_cxx/api_core.html"><img src="/images/api.gif" alt="API"></a><a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a> 72</td></tr></table> 73<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 74</body> 75</html> 76
