<!--$Id: log_file.so,v 10.34 2004/08/13 03:38:57 bostic Exp $--> <!--Copyright (c) 1997,2007 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DbEnv::log_file</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <h3>DbEnv::log_file</h3> </td> <td align=right> <a href="../../db46-devel-4.6.21/api_cxx/api_core.html"><img src="../../db46-devel-4.6.21/images/api.gif" alt="API"></a> <a href="../../db46-devel-4.6.21/ref/toc.html"><img src="../../db46-devel-4.6.21/images/ref.gif" alt="Ref"></a></td> </tr></table> <hr size=1 noshade> <tt> <h3><pre> #include <db_cxx.h> <p> int DbEnv::log_file(const DbLsn *lsn, char *namep, size_t len); </pre></h3> <hr size=1 noshade> <h3>Description: DbEnv::log_file</h3> <p>The DbEnv::log_file method maps <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> objects to filenames, returning the name of the file containing the record named by <b>lsn</b>.</p> <p>This mapping of <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> objects to files is needed for database administration. For example, a transaction manager typically records the earliest <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> needed for restart, and the database administrator may want to archive log files to tape when they contain only <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> entries before the earliest one needed for restart.</p> <p>The DbEnv::log_file 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. </p> <h3>Parameters</h3> <dl compact> <dt><b>lsn</b><dd>The <b>lsn</b> parameter is the <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> object for which a filename is wanted. <dt><b>namep</b><dd>The <b>namep</b> parameter references memory into which the name of the file containing the record named by <b>lsn</b> is copied. <dt><b>len</b><dd>The <b>len</b> parameter is the length of the <b>namep</b> buffer in bytes. If <b>namep</b> is too short to hold the filename, DbEnv::log_file will fail. (Log filenames are normally quite short, on the order of 10 characters.) </dl> <h3>Errors</h3> <p>The DbEnv::log_file method may fail and throw <a href="../../db46-devel-4.6.21/api_cxx/except_class.html">DbException</a>, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:</p> <dl compact> <dt>EINVAL<dd>If supplied buffer was too small to hold the log filename; or if an invalid flag value or parameter was specified. </dl> <hr size=1 noshade> <h3>Class</h3> <a href="../../db46-devel-4.6.21/api_cxx/env_class.html">DbEnv</a>, <a href="../../db46-devel-4.6.21/api_cxx/logc_class.html">DbLogc</a>, <a href="../../db46-devel-4.6.21/api_cxx/lsn_class.html">DbLsn</a> <h3>See Also</h3> <a href="../../db46-devel-4.6.21/api_cxx/log_list.html">Logging Subsystem and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../../db46-devel-4.6.21/api_cxx/api_core.html"><img src="../../db46-devel-4.6.21/images/api.gif" alt="API"></a><a href="../../db46-devel-4.6.21/ref/toc.html"><img src="../../db46-devel-4.6.21/images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2007 Oracle. All rights reserved.</font> </body> </html>