mariadb/plugin/sql_errlog/service_logger.h
Alexey Botchkov 5c01f1ac14 MDEV-15 Log all sql errors.
modified for MySQL 5.5. Logger service moved to the
        plugin/sql_errlog directory to be properly used later.

plugin/sql_errlog/sql_errlog.c:
  Fixes for bugs #956427 (SQL_ERROR_LOG plugin produces bogus warnings about sql-error-log-size-limit value) and #956463 (Server crashes if SQL_ERROR_LOG fails to initialize) they're also MDEV-184 and MDEV-183
    
  The sql_error_log_deinit() should be prepared for the logger_file to be NULL.
  The logger_file_size_limit upper limit wasn't properly set.
2012-03-24 11:24:20 +01:00

100 lines
3.1 KiB
C

/* Copyright (C) 2012 Monty Program Ab
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef MYSQL_SERVICE_LOGGER_INCLUDED
#define MYSQL_SERVICE_LOGGER_INCLUDED
#ifndef MYSQL_ABI_CHECK
#include <stdarg.h>
#endif
/**
@file
logger service
Log file with rotation implementation.
This service implements logging with possible rotation
of the log files. Interface intentionally tries to be similar to FILE*
related functions.
So that one can open the log with logger_open(), specifying
the limit on the logfile size and the rotations number.
Then it's possible to write messages to the log with
logger_printf or logger_vprintf functions.
As the size of the logfile grows over the specified limit,
it is renamed to 'logfile.1'. The former 'logfile.1' becomes
'logfile.2', etc. The file 'logfile.rotations' is removed.
That's how the rotation works.
The rotation can be forced with the logger_rotate() call.
Finally the log should be closed with logger_close().
@notes:
Implementation checks the size of the log file before it starts new
printf into it. So the size of the file gets over the limit when it rotates.
The access is secured with the mutex, so the log is threadsafe.
*/
#ifdef __cplusplus
extern "C" {
#endif
typedef struct logger_handle_st LOGGER_HANDLE;
extern struct logger_service_st {
LOGGER_HANDLE* (*open)(const char *path,
unsigned long long size_limit,
unsigned int rotations);
int (*close)(LOGGER_HANDLE *log);
int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
int (*rotate)(LOGGER_HANDLE *log);
} *logger_service;
#if 0 /*MYSQL_DYNAMIC_PLUGIN*/
#define logger_open(path, size_limit, rotations) \
(logger_service->open(path, size_limit, rotations))
#define logger_close(log) (logger_service->close(log))
#define logger_rotate(log) (logger_service->rotate(log))
#define logger_vprintf(log, fmt, argptr) (logger_service->\
vprintf(log, fmt, argptr))
#define logger_printf logger_service->printf
#else
LOGGER_HANDLE *logger_open(const char *path,
unsigned long long size_limit,
unsigned int rotations);
int logger_close(LOGGER_HANDLE *log);
int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
int logger_rotate(LOGGER_HANDLE *log);
int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
void init_logger_mutexes();
#endif
#ifdef __cplusplus
}
#endif
#endif /*MYSQL_SERVICE_LOGGER_INCLUDED*/