1<!--$Id: log_put.so,v 10.41 2004/08/13 03:38:57 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: DB_ENV->log_put</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> 13<b>DB_ENV->log_put</b> 14</td> 15<td align=right> 16<a href="/api_c/api_core.html"><img src="/images/api.gif" alt="API"></a> 17<a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a></td> 18</tr></table> 19<hr size=1 noshade> 20<tt> 21<b><pre> 22#include <db.h> 23<p> 24int 25DB_ENV->log_put(DB_ENV *env, 26 DB_LSN *lsn, const DBT *data, u_int32_t flags); 27</pre></b> 28<hr size=1 noshade> 29<b>Description: DB_ENV->log_put</b> 30<p>The DB_ENV->log_put method appends records to the log. The <a href="/api_c/lsn_class.html">DB_LSN</a> of 31the put record is returned in the <b>lsn</b> parameter.</p> 32<p>The DB_ENV->log_put method 33returns a non-zero error value on failure 34and 0 on success. 35</p> 36<b>Parameters</b> <br> 37 <b>data</b><ul compact><li>The <b>data</b> parameter is the record to write to the log. 38<p>The caller is responsible for providing any necessary structure to 39<b>data</b>. (For example, in a write-ahead logging protocol, the 40application must understand what part of <b>data</b> is an operation 41code, what part is redo information, and what part is undo information. 42In addition, most transaction managers will store in <b>data</b> the 43<a href="/api_c/lsn_class.html">DB_LSN</a> of the previous log record for the same transaction, to 44support chaining back through the transaction's log records during 45undo.)</p></ul> 46 <b>flags</b><ul compact><li>The <b>flags</b> parameter must be set to 0 or 47the following value: 48<br> 49<b><a name="DB_FLUSH">DB_FLUSH</a></b><ul compact><li>The log is forced to disk after this record is written, guaranteeing 50that all records with <a href="/api_c/lsn_class.html">DB_LSN</a> values less than or equal to the 51one being "put" are on disk before DB_ENV->log_put returns.</ul> 52<br></ul> 53 <b>lsn</b><ul compact><li>The <b>lsn</b> parameter references memory into which 54 the <a href="/api_c/lsn_class.html">DB_LSN</a> of the put record is copied.</ul> 55<br> 56<br><b>Errors</b> 57<p>The <a href="/api_c/log_flush.html">DB_ENV->log_flush</a> method 58may fail and return one of the following non-zero errors:</p> 59<br> 60<b>EINVAL</b><ul compact><li>If the record to be logged is larger than the maximum log record; or if an 61invalid flag value or parameter was specified.</ul> 62<br> 63<hr size=1 noshade> 64<br><b>Class</b> 65<a href="/api_c/env_class.html">DB_ENV</a>, <a href="/api_c/logc_class.html">DB_LOGC</a>, <a href="/api_c/lsn_class.html">DB_LSN</a> 66<br><b>See Also</b> 67<a href="/api_c/log_list.html">Logging Subsystem and Related Methods</a> 68</tt> 69<table width="100%"><tr><td><br></td><td align=right> 70<a href="/api_c/api_core.html"><img src="/images/api.gif" alt="API"></a><a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a> 71</td></tr></table> 72<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 73</body> 74</html> 75
