ag/cpython-source-deps
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Import BSDDB 4.7.25 (as of svn r89086)

Browse Source
This commit is contained in:
Zachary Ware
2017-09-04 13:40:25 -05:00
parent 4b29e0458f
commit 8f590873d0
4781 changed files with 2241032 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
docs/api_cxx/memp_set_fileid.html Normal file
View File

@@ -0,0 +1,92 @@
<!--$Id: memp_set_fileid.html 63573 2008-05-23 21:43:21Z trent.nelson $-->
<!--Copyright (c) 1997,2008 Oracle. All rights reserved.-->
<!--See the file LICENSE for redistribution information.-->
<html>
<head>
<title>Berkeley DB: DbMpoolFile::set_fileid</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>
<b>DbMpoolFile::set_fileid</b>
</td>
<td align=right>
<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></td>
</tr></table>
<hr size=1 noshade>
<tt>
<b><pre>
#include &lt;db_cxx.h&gt;
<p>
int
DbMpoolFile::set(u_int8_t *fileid);
<p>
int DbMpoolFile::get_fileid(u_int8_t *fileid);
</pre></b>
<hr size=1 noshade>
<b>Description: DbMpoolFile::set_fileid</b>
<p>The DbMpoolFile::set_fileid method specifies a unique identifier for the file.
(The shared memory buffer pool functions must be able to uniquely
identify files in order that multiple processes wanting to share a file
will correctly identify it in the pool.)</p>
<p>On most UNIX/POSIX systems, the <b>fileid</b> field will not need to
be set, and the memory pool functions will use the file's device and
inode numbers for this purpose. On Windows systems, the memory pool
functions use the values returned by GetFileInformationByHandle() by
default -- these values are known to be constant between processes and
over reboot in the case of NTFS (in which they are the NTFS MFT
indices).</p>
<p>On other filesystems (for example, FAT or NFS), these default values
are not necessarily unique between processes or across system reboots.
<b>Applications wanting to maintain a shared memory buffer pool
between processes or across system reboots, in which the pool contains
pages from files stored on such filesystems, must specify a unique file
identifier using the DbMpoolFile::set_fileid method, and each process opening
the file must provide the same unique identifier.</b></p>
<p>This call should not be necessary for most applications. Specifically,
it is not necessary if the memory pool is not shared between processes
and is reinstantiated after each system reboot, if the application is
using the Berkeley DB access methods instead of calling the pool functions
explicitly, or if the files in the memory pool are stored on filesystems
in which the default values as described previously are invariant
between process and across system reboots.</p>
<p>The DbMpoolFile::set_fileid method configures a file in the memory pool, not only
operations performed using the specified <a href="../api_cxx/mempfile_class.html">DbMpoolFile</a> handle.</p>
<p>The DbMpoolFile::set_fileid method may not be called after the <a href="../api_cxx/memp_fopen.html">DbMpoolFile::open</a> method is
called.
</p>
<p>The DbMpoolFile::set_fileid 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>
<b>Parameters</b> <br>
<b>fileid</b><ul compact><li>The <b>fileid</b> parameter is the unique identifier for the file.
Unique file identifiers must be a DB_FILE_ID_LEN length array of bytes.</ul>
<br>
<hr size=1 noshade>
<b>Description: DbMpoolFile::get_fileid</b>
<p>The DbMpoolFile::get_fileid method copies the file's identifier into the
memory location referenced by <b>fileid</b>.</p>
<p>The DbMpoolFile::get_fileid 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>
<p>The DbMpoolFile::get_fileid method may be called at any time during the life of the
application.</p>
<hr size=1 noshade>
<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>, <a href="../api_cxx/mempfile_class.html">DbMpoolFile</a>
<br><b>See Also</b>
<a href="../api_cxx/memp_list.html">Memory Pools and Related Methods</a>
</tt>
<table width="100%"><tr><td><br></td><td align=right>
<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>
</td></tr></table>
<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font>
</body>
</html>