<!--$Id: log_stat.so,v 10.59 2007/09/21 20:06:02 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DB_ENV->log_stat</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>DB_ENV->log_stat</b> </td> <td align=right> <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></td> </tr></table> <hr size=1 noshade> <tt> <b><pre> #include <db.h> <p> int DB_ENV->log_stat(DB_ENV *env, DB_LOG_STAT **statp, u_int32_t flags); <p> int DB_ENV->log_stat_print(DB_ENV *env, u_int32_t flags); </pre></b> <hr size=1 noshade> <b>Description: DB_ENV->log_stat</b> <p>The DB_ENV->log_stat method returns the logging subsystem statistics.</p> <p>The DB_ENV->log_stat method creates a statistical structure of type DB_LOG_STAT and copies a pointer to it into a user-specified memory location.</p> <p>Statistical structures are stored in allocated memory. If application-specific allocation routines have been declared (see <a href="../api_c/env_set_alloc.html">DB_ENV->set_alloc</a> for more information), they are used to allocate the memory; otherwise, the standard C library <b>malloc</b>(3) is used. The caller is responsible for deallocating the memory. To deallocate the memory, free the memory reference; references inside the returned memory need not be individually freed.</p> <p>The following DB_LOG_STAT fields will be filled in:</p> <br> <b>u_int32_t st_magic;</b><ul compact><li>The magic number that identifies a file as a log file.</ul> <b>u_int32_t st_version;</b><ul compact><li>The version of the log file type.</ul> <b>int st_mode;</b><ul compact><li>The mode of any created log files.</ul> <b>u_int32_t st_lg_bsize;</b><ul compact><li>The in-memory log record cache size.</ul> <b>u_int32_t st_lg_size;</b><ul compact><li>The log file size.</ul> <b>u_int32_t st_record;</b><ul compact><li>The number of records written to this log.</ul> <b>u_int32_t st_w_mbytes;</b><ul compact><li>The number of megabytes written to this log.</ul> <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> <b>u_int32_t st_wc_mbytes;</b><ul compact><li>The number of megabytes written to this log since the last checkpoint.</ul> <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 since the last checkpoint.</ul> <b>u_int32_t st_wcount;</b><ul compact><li>The number of times the log has been written to disk.</ul> <b>u_int32_t st_wcount_fill;</b><ul compact><li>The number of times the log has been written to disk because the in-memory log record cache filled up.</ul> <b>u_int32_t st_rcount;</b><ul compact><li>The number of times the log has been read from disk.</ul> <b>u_int32_t st_scount;</b><ul compact><li>The number of times the log has been flushed to disk.</ul> <b>u_int32_t st_cur_file;</b><ul compact><li>The current log file number.</ul> <b>u_int32_t st_cur_offset;</b><ul compact><li>The byte offset in the current log file.</ul> <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> <b>u_int32_t st_disk_offset;</b><ul compact><li>The byte offset of the last record known to be on disk.</ul> <b>u_int32_t st_maxcommitperflush;</b><ul compact><li>The maximum number of commits contained in a single log flush.</ul> <b>u_int32_t st_mincommitperflush;</b><ul compact><li>The minimum number of commits contained in a single log flush that contained a commit.</ul> <b>roff_t st_regsize;</b><ul compact><li>The size of the log region, in bytes.</ul> <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 obtaining the log region mutex.</ul> <b>u_int32_t st_region_nowait;</b><ul compact><li>The number of times that a thread of control was able to obtain the log region mutex without waiting.</ul> <br> <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> <p>The DB_ENV->log_stat method returns a non-zero error value on failure and 0 on success. </p> <b>Parameters</b> <br> <b>flags</b><ul compact><li>The <b>flags</b> parameter must be set to 0 or the following value: <br> <b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after returning their values.</ul> <br></ul> <b>statp</b><ul compact><li>The <b>statp</b> parameter references memory into which a pointer to the allocated statistics structure is copied.</ul> <br> <br><b>Errors</b> <p>The DB_ENV->log_stat method may fail and return one of the following non-zero errors:</p> <br> <b>EINVAL</b><ul compact><li>An invalid flag value or parameter was specified.</ul> <br> <hr size=1 noshade> <b>Description: DB_ENV->log_stat_print</b> <p>The DB_ENV->log_stat_print method displays the logging subsystem statistical information, as described for the DB_ENV->log_stat method. The information is printed to a specified output channel (see the <a href="../api_c/env_set_msgfile.html">DB_ENV->set_msgfile</a> method for more information), or passed to an application callback function (see the <a href="../api_c/env_set_msgcall.html">DB_ENV->set_msgcall</a> method for more information).</p> <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> <p>The DB_ENV->log_stat_print method returns a non-zero error value on failure and 0 on success. </p> <b>Parameters</b> <br> <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 or more of the following values: <br> <b><a name="DB_STAT_ALL">DB_STAT_ALL</a></b><ul compact><li>Display all available information.</ul> <b><a name="DB_STAT_CLEAR">DB_STAT_CLEAR</a></b><ul compact><li>Reset statistics after displaying their values.</ul> <br></ul> <br> <hr size=1 noshade> <br><b>Class</b> <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> <br><b>See Also</b> <a href="../api_c/log_list.html">Logging Subsystem and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <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> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. 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