Berkeley DB: DbEnv::log

DbEnv::log_stat

#include <db_cxx.h> int DbEnv::log_stat(DB_LOG_STAT **statp, u_int32_t flags); int DbEnv::log_stat_print(u_int32_t flags); Description: DbEnv::log_stat The DbEnv::log_stat method returns the logging subsystem statistics. The DbEnv::log_stat method creates a statistical structure of type DB_LOG_STAT and copies a pointer to it into a user-specified memory location. Statistical structures are stored in allocated memory. If application-specific allocation routines have been declared (see DbEnv::set_alloc for more information), they are used to allocate the memory; otherwise, the standard C library malloc(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. The following DB_LOG_STAT fields will be filled in: u_int32_t st_magic; The magic number that identifies a file as a log file. u_int32_t st_version; The version of the log file type. int st_mode; The mode of any created log files. u_int32_t st_lg_bsize; The in-memory log record cache size. u_int32_t st_lg_size; The log file size. u_int32_t st_record; The number of records written to this log. u_int32_t st_w_mbytes; The number of megabytes written to this log. u_int32_t st_w_bytes; The number of bytes over and above st_w_mbytes written to this log. u_int32_t st_wc_mbytes; The number of megabytes written to this log since the last checkpoint. u_int32_t st_wc_bytes; The number of bytes over and above st_wc_mbytes written to this log since the last checkpoint. u_int32_t st_wcount; The number of times the log has been written to disk. u_int32_t st_wcount_fill; The number of times the log has been written to disk because the in-memory log record cache filled up. u_int32_t st_rcount; The number of times the log has been read from disk. u_int32_t st_scount; The number of times the log has been flushed to disk. u_int32_t st_cur_file; The current log file number. u_int32_t st_cur_offset; The byte offset in the current log file. u_int32_t st_disk_file; The log file number of the last record known to be on disk. u_int32_t st_disk_offset; The byte offset of the last record known to be on disk. u_int32_t st_maxcommitperflush; The maximum number of commits contained in a single log flush. u_int32_t st_mincommitperflush; The minimum number of commits contained in a single log flush that contained a commit. roff_t st_regsize; The size of the log region, in bytes. u_int32_t st_region_wait; The number of times that a thread of control was forced to wait before obtaining the log region mutex. u_int32_t st_region_nowait; The number of times that a thread of control was able to obtain the log region mutex without waiting. The DbEnv::log_stat 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. Parameters flags The flags parameter must be set to 0 or the following value: DB_STAT_CLEAR Reset statistics after returning their values. statp The statp parameter references memory into which a pointer to the allocated statistics structure is copied. Errors The DbEnv::log_stat method may fail and throw DbException, encapsulating one of the following non-zero errors, or return one of the following non-zero errors: EINVAL An invalid flag value or parameter was specified. Description: DbEnv::log_stat_print The DbEnv::log_stat_print method displays the logging subsystem statistical information, as described for the DbEnv::log_stat method. The information is printed to a specified output channel (see the DbEnv::set_msgfile method for more information), or passed to an application callback function (see the DbEnv::set_msgcall method for more information). The DbEnv::log_stat_print method may not be called before the DbEnv::open method has been called. The DbEnv::log_stat_print 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. Parameters flags The flags parameter must be set to 0 or the following value: DB_STAT_ALL Display all available information. Class DbEnv, DbLogc, DbLsn See Also Logging Subsystem and Related Methods