1<!--$Id: log_stat.so,v 10.59 2007/09/21 20:06:02 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_stat</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_stat</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_stat(DB_ENV *env, DB_LOG_STAT **statp, u_int32_t flags); 26<p> 27int 28DB_ENV->log_stat_print(DB_ENV *env, u_int32_t flags); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DB_ENV->log_stat</b> 32<p>The DB_ENV->log_stat method returns the logging subsystem statistics.</p> 33<p>The DB_ENV->log_stat method creates a statistical structure of type 34DB_LOG_STAT and copies a pointer to it into a user-specified memory 35location.</p> 36<p>Statistical structures are stored in allocated memory. If application-specific allocation 37routines have been declared (see <a href="../api_c/env_set_alloc.html">DB_ENV->set_alloc</a> for more 38information), they are used to allocate the memory; otherwise, the 39standard C library <b>malloc</b>(3) is used. The caller is 40responsible for deallocating the memory. To deallocate the memory, free 41the memory reference; references inside the returned memory need not be 42individually freed.</p> 43<p>The following DB_LOG_STAT fields will be filled in:</p> 44<br> 45<b>u_int32_t st_magic;</b><ul compact><li>The magic number that identifies a file as a log file.</ul> 46<b>u_int32_t st_version;</b><ul compact><li>The version of the log file type.</ul> 47<b>int st_mode;</b><ul compact><li>The mode of any created log files.</ul> 48<b>u_int32_t st_lg_bsize;</b><ul compact><li>The in-memory log record cache size.</ul> 49<b>u_int32_t st_lg_size;</b><ul compact><li>The log file size.</ul> 50<b>u_int32_t st_record;</b><ul compact><li>The number of records written to this log.</ul> 51<b>u_int32_t st_w_mbytes;</b><ul compact><li>The number of megabytes written to this log.</ul> 52<b>u_int32_t st_w_bytes;</b><ul compact><li>The number of bytes over and above <b>st_w_mbytes</b> written to this log.</ul> 53<b>u_int32_t st_wc_mbytes;</b><ul compact><li>The number of megabytes written to this log since the last checkpoint.</ul> 54<b>u_int32_t st_wc_bytes;</b><ul compact><li>The number of bytes over and above <b>st_wc_mbytes</b> written to this log 55since the last checkpoint.</ul> 56<b>u_int32_t st_wcount;</b><ul compact><li>The number of times the log has been written to disk.</ul> 57<b>u_int32_t st_wcount_fill;</b><ul compact><li>The number of times the log has been written to disk because the 58in-memory log record cache filled up.</ul> 59<b>u_int32_t st_rcount;</b><ul compact><li>The number of times the log has been read from disk.</ul> 60<b>u_int32_t st_scount;</b><ul compact><li>The number of times the log has been flushed to disk.</ul> 61<b>u_int32_t st_cur_file;</b><ul compact><li>The current log file number.</ul> 62<b>u_int32_t st_cur_offset;</b><ul compact><li>The byte offset in the current log file.</ul> 63<b>u_int32_t st_disk_file;</b><ul compact><li>The log file number of the last record known to be on disk.</ul> 64<b>u_int32_t st_disk_offset;</b><ul compact><li>The byte offset of the last record known to be on disk.</ul> 65<b>u_int32_t st_maxcommitperflush;</b><ul compact><li>The maximum number of commits contained in a single log flush.</ul> 66<b>u_int32_t st_mincommitperflush;</b><ul compact><li>The minimum number of commits contained in a single log flush that 67contained a commit.</ul> 68<b>roff_t st_regsize;</b><ul compact><li>The size of the log region, in bytes.</ul> 69<b>u_int32_t st_region_wait;</b><ul compact><li>The number of times that a thread of control was forced to wait before 70obtaining the log region mutex.</ul> 71<b>u_int32_t st_region_nowait;</b><ul compact><li>The number of times that a thread of control was able to obtain 72the log region mutex without waiting.</ul> 73<br> 74<p>The DB_ENV->log_stat method may not be called before the <a href="../api_c/env_open.html">DB_ENV->open</a> method is called.</p> 75<p>The DB_ENV->log_stat method 76returns a non-zero error value on failure 77and 0 on success. 78</p> 79<b>Parameters</b> <br> 80 <b>flags</b><ul compact><li>The <b>flags</b> parameter must be set to 0 or 81the following value: 82<br> 83<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after returning their values.</ul> 84<br></ul> 85 <b>statp</b><ul compact><li>The <b>statp</b> parameter references memory into which 86a pointer to the allocated statistics structure is copied.</ul> 87<br> 88<br><b>Errors</b> 89<p>The DB_ENV->log_stat method 90may fail and return one of the following non-zero errors:</p> 91<br> 92<b>EINVAL</b><ul compact><li>An 93invalid flag value or parameter was specified.</ul> 94<br> 95<hr size=1 noshade> 96<b>Description: DB_ENV->log_stat_print</b> 97<p>The DB_ENV->log_stat_print method displays the 98logging subsystem statistical information, as described for the DB_ENV->log_stat method. 99The information is printed to a specified output channel (see the 100<a href="../api_c/env_set_msgfile.html">DB_ENV->set_msgfile</a> method for more information), or passed to an 101application callback function (see the <a href="../api_c/env_set_msgcall.html">DB_ENV->set_msgcall</a> method for 102more information).</p> 103<p>The DB_ENV->log_stat_print method may not be called before the <a href="../api_c/env_open.html">DB_ENV->open</a> method is called.</p> 104<p>The DB_ENV->log_stat_print method 105returns a non-zero error value on failure 106and 0 on success. 107</p> 108<b>Parameters</b> <br> 109 <b>flags</b><ul compact><li>The <b>flags</b> parameter must be set to 0 or by bitwise inclusively <b>OR</b>'ing together one 110or more of the following values: 111<br> 112<b><a name="DB_STAT_ALL">DB_STAT_ALL</a></b><ul compact><li>Display all available information.</ul> 113<b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after displaying their values.</ul> 114<br></ul> 115<br> 116<hr size=1 noshade> 117<br><b>Class</b> 118<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> 119<br><b>See Also</b> 120<a href="../api_c/log_list.html">Logging Subsystem and Related Methods</a> 121</tt> 122<table width="100%"><tr><td><br></td><td align=right> 123<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> 124</td></tr></table> 125<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 126</body> 127</html> 128
