1<!--$Id: mp.so,v 1.4 2007/04/05 21:19:31 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 4.0: memp_XXX</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.4.0/log.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/upgrade.4.0/txn.html"><img src="/images/next.gif" alt="Next"></a> 14</td></tr></table> 15<p align=center><b>Release 4.0: memp_XXX</b></p> 16<p>The C API for the Berkeley DB Memory Pool subsystem was reworked in the 4.0 17release as follows:</p> 18<table border=1 align=center> 19<tr><th>Historic functional interface</th><th>Berkeley DB 4.X method</th></tr> 20<tr><td>memp_register</td><td><a href="/api_c/memp_register.html">DB_ENV->memp_register</a></td></tr> 21<tr><td>memp_stat</td><td><a href="/api_c/memp_stat.html">DB_ENV->memp_stat</a></td></tr> 22<tr><td>memp_sync</td><td><a href="/api_c/memp_sync.html">DB_ENV->memp_sync</a></td></tr> 23<tr><td>memp_trickle</td><td><a href="/api_c/memp_trickle.html">DB_ENV->memp_trickle</a></td></tr> 24<tr><td>memp_fopen</td><td><a href="/api_c/memp_fcreate.html">DB_ENV->memp_fcreate</a></td></tr> 25<tr><td>DB_MPOOL_FINFO: ftype</td><td><a href="/api_c/memp_set_ftype.html">DB_MPOOLFILE->set_ftype</a></td></tr> 26<tr><td>DB_MPOOL_FINFO: pgcookie</td><td><a href="/api_c/memp_set_pgcookie.html">DB_MPOOLFILE->set_pgcookie</a></td></tr> 27<tr><td>DB_MPOOL_FINFO: fileid</td><td><a href="/api_c/memp_set_fileid.html">DB_MPOOLFILE->set_fileid</a></td></tr> 28<tr><td>DB_MPOOL_FINFO: lsn_offset</td><td><a href="/api_c/memp_set_lsn_offset.html">DB_MPOOLFILE->set_lsn_offset</a></td></tr> 29<tr><td>DB_MPOOL_FINFO: clear_len</td><td><a href="/api_c/memp_set_clear_len.html">DB_MPOOLFILE->set_clear_len</a></td></tr> 30<tr><td>memp_fopen</td><td><a href="/api_c/memp_fopen.html">DB_MPOOLFILE->open</a></td></tr> 31<tr><td>memp_fclose</td><td><a href="/api_c/memp_fclose.html">DB_MPOOLFILE->close</a></td></tr> 32<tr><td>memp_fput</td><td><a href="/api_c/memp_fput.html">DB_MPOOLFILE->put</a></td></tr> 33<tr><td>memp_fset</td><td>DB_MPOOLFILE->set</td></tr> 34<tr><td>memp_fsync</td><td><a href="/api_c/memp_fsync.html">DB_MPOOLFILE->sync</a></td></tr> 35</table> 36<p>Applications calling any of the memp_register, memp_stat, memp_sync or 37memp_trickle functions should update those calls to use the enclosing 38<a href="/api_c/env_class.html">DB_ENV</a> handle's method (easily done as the first argument to the 39existing call is the correct <a href="/api_c/env_class.html">DB_ENV</a> handle).</p> 40<p>In addition, the <a href="/api_c/memp_stat.html">DB_ENV->memp_stat</a> call has been changed in the 4.0 41release to take a flags argument. To leave their historic behavior 42unchanged, applications should add a final argument of 0 to any calls 43made to <a href="/api_c/memp_stat.html">DB_ENV->memp_stat</a>.</p> 44<p>Applications calling the memp_fopen function should update those calls 45as follows: First, acquire a <a href="/api_c/mempfile_class.html">DB_MPOOLFILE</a> handle using the 46<a href="/api_c/memp_fcreate.html">DB_ENV->memp_fcreate</a> method. Second, if the DB_MPOOL_FINFO structure 47reference passed to the memp_fopen function was non-NULL, call the 48<a href="/api_c/mempfile_class.html">DB_MPOOLFILE</a> method corresponding to each initialized field in 49the DB_MPOOL_FINFO structure. Third, call the <a href="/api_c/memp_fopen.html">DB_MPOOLFILE->open</a> method 50method to open the underlying file. If the <a href="/api_c/memp_fopen.html">DB_MPOOLFILE->open</a> method call 51fails, then <a href="/api_c/memp_fclose.html">DB_MPOOLFILE->close</a> method must be called to destroy the allocated 52handle.</p> 53<p>Applications calling the memp_fopen, memp_fclose, memp_fput, memp_fset, 54or memp_fsync functions should update those calls to use the enclosing 55<a href="/api_c/mempfile_class.html">DB_MPOOLFILE</a> handle's method. Again, this is easily done as the 56first argument to the existing call is the correct <a href="/api_c/mempfile_class.html">DB_MPOOLFILE</a> 57handle. With one exception, the calling conventions of the old and new 58interfaces are identical; the one exception is the <a href="/api_c/memp_fclose.html">DB_MPOOLFILE->close</a> method, 59which requires an additional flag parameter that should be set to 0.</p> 60<table width="100%"><tr><td><br></td><td align=right><a href="/upgrade.4.0/log.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/upgrade.4.0/txn.html"><img src="/images/next.gif" alt="Next"></a> 61</td></tr></table> 62<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 63</body> 64</html> 65