mysql-5.5.62/sql/log.h

/* Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.

   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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#ifndef LOG_H
#define LOG_H

#include "unireg.h"                    // REQUIRED: for other includes
#include "handler.h"                            /* my_xid */

class Relay_log_info;

class Format_description_log_event;

bool trans_has_updated_trans_table(const THD* thd);
bool stmt_has_updated_trans_table(Ha_trx_info* ha_list);
bool use_trans_cache(const THD* thd, bool is_transactional);
bool ending_trans(THD* thd, const bool all);
bool ending_single_stmt_trans(THD* thd, const bool all);
bool trans_has_updated_non_trans_table(const THD* thd);
bool stmt_has_updated_non_trans_table(const THD* thd);

/*
  Transaction Coordinator log - a base abstract class
  for two different implementations
*/
class TC_LOG
{
  public:
  int using_heuristic_recover();
  TC_LOG() {}
  virtual ~TC_LOG() {}

  virtual int open(const char *opt_name)=0;
  virtual void close()=0;
  virtual int log_xid(THD *thd, my_xid xid)=0;
  virtual int unlog(ulong cookie, my_xid xid)=0;
};

class TC_LOG_DUMMY: public TC_LOG // use it to disable the logging
{
public:
  TC_LOG_DUMMY() {}
  int open(const char *opt_name)        { return 0; }
  void close()                          { }
  int log_xid(THD *thd, my_xid xid)         { return 1; }
  int unlog(ulong cookie, my_xid xid)  { return 0; }
};

#ifdef HAVE_MMAP
class TC_LOG_MMAP: public TC_LOG
{
  public:                // only to keep Sun Forte on sol9x86 happy
  typedef enum {
    PS_POOL,                 // page is in pool
    PS_ERROR,                // last sync failed
    PS_DIRTY                 // new xids added since last sync
  } PAGE_STATE;

  private:
  typedef struct st_page {
    struct st_page *next; // page a linked in a fifo queue
    my_xid *start, *end;  // usable area of a page
    my_xid *ptr;          // next xid will be written here
    int size, free;       // max and current number of free xid slots on the page
    int waiters;          // number of waiters on condition
    PAGE_STATE state;     // see above
    mysql_mutex_t lock; // to access page data or control structure
    mysql_cond_t  cond; // to wait for a sync
  } PAGE;

  char logname[FN_REFLEN];
  File fd;
  my_off_t file_length;
  uint npages, inited;
  uchar *data;
  struct st_page *pages, *syncing, *active, *pool, *pool_last;
  /*
    note that, e.g. LOCK_active is only used to protect
    'active' pointer, to protect the content of the active page
    one has to use active->lock.
    Same for LOCK_pool and LOCK_sync
  */
  mysql_mutex_t LOCK_active, LOCK_pool, LOCK_sync;
  mysql_cond_t COND_pool, COND_active;

  public:
  TC_LOG_MMAP(): inited(0) {}
  int open(const char *opt_name);
  void close();
  int log_xid(THD *thd, my_xid xid);
  int unlog(ulong cookie, my_xid xid);
  int recover();

  private:
  void get_active_from_pool();
  int sync();
  int overflow();
};
#else
#define TC_LOG_MMAP TC_LOG_DUMMY
#endif

extern TC_LOG *tc_log;
extern TC_LOG_MMAP tc_log_mmap;
extern TC_LOG_DUMMY tc_log_dummy;

/* log info errors */
#define LOG_INFO_EOF -1
#define LOG_INFO_IO  -2
#define LOG_INFO_INVALID -3
#define LOG_INFO_SEEK -4
#define LOG_INFO_MEM -6
#define LOG_INFO_FATAL -7
#define LOG_INFO_IN_USE -8
#define LOG_INFO_EMFILE -9


/* bitmap to SQL_LOG::close() */
#define LOG_CLOSE_INDEX		1
#define LOG_CLOSE_TO_BE_OPENED	2
#define LOG_CLOSE_STOP_EVENT	4

/*
  Maximum unique log filename extension.
  Note: setting to 0x7FFFFFFF due to atol windows
        overflow/truncate.
 */
#define MAX_LOG_UNIQUE_FN_EXT 0x7FFFFFFF

/*
   Number of warnings that will be printed to error log
   before extension number is exhausted.
*/
#define LOG_WARN_UNIQUE_FN_EXT_LEFT 1000

class Relay_log_info;

#ifdef HAVE_PSI_INTERFACE
extern PSI_mutex_key key_LOG_INFO_lock;
#endif

/*
  Note that we destroy the lock mutex in the desctructor here.
  This means that object instances cannot be destroyed/go out of scope,
  until we have reset thd->current_linfo to NULL;
 */
typedef struct st_log_info
{
  char log_file_name[FN_REFLEN];
  my_off_t index_file_offset, index_file_start_offset;
  my_off_t pos;
  bool fatal; // if the purge happens to give us a negative offset
  mysql_mutex_t lock;
  st_log_info()
    : index_file_offset(0), index_file_start_offset(0),
      pos(0), fatal(0)
    {
      log_file_name[0] = '\0';
      mysql_mutex_init(key_LOG_INFO_lock, &lock, MY_MUTEX_INIT_FAST);
    }
  ~st_log_info() { mysql_mutex_destroy(&lock);}
} LOG_INFO;

/*
  Currently we have only 3 kinds of logging functions: old-fashioned
  logs, stdout and csv logging routines.
*/
#define MAX_LOG_HANDLERS_NUM 3

/* log event handler flags */
#define LOG_NONE       1
#define LOG_FILE       2
#define LOG_TABLE      4

class Log_event;
class Rows_log_event;

enum enum_log_type { LOG_UNKNOWN, LOG_NORMAL, LOG_BIN };
enum enum_log_state { LOG_OPENED, LOG_CLOSED, LOG_TO_BE_OPENED };

/*
  TODO use mmap instead of IO_CACHE for binlog
  (mmap+fsync is two times faster than write+fsync)
*/

class MYSQL_LOG
{
public:
  MYSQL_LOG();
  void init_pthread_objects();
  void cleanup();
  bool open(
#ifdef HAVE_PSI_INTERFACE
            PSI_file_key log_file_key,
#endif
            const char *log_name,
            enum_log_type log_type,
            const char *new_name,
            enum cache_type io_cache_type_arg);
  bool init_and_set_log_file_name(const char *log_name,
                                  const char *new_name,
                                  enum_log_type log_type_arg,
                                  enum cache_type io_cache_type_arg);
  void init(enum_log_type log_type_arg,
            enum cache_type io_cache_type_arg);
  void close(uint exiting);
  inline bool is_open() { return log_state != LOG_CLOSED; }
  const char *generate_name(const char *log_name, const char *suffix,
                            bool strip_ext, char *buff);
  int generate_new_name(char *new_name, const char *log_name);
 protected:
  /* LOCK_log is inited by init_pthread_objects() */
  mysql_mutex_t LOCK_log;
  char *name;
  char log_file_name[FN_REFLEN];
  char time_buff[20], db[NAME_LEN + 1];
  bool write_error, inited;
  IO_CACHE log_file;
  enum_log_type log_type;
  volatile enum_log_state log_state;
  enum cache_type io_cache_type;
  friend class Log_event;
#ifdef HAVE_PSI_INTERFACE
  /** Instrumentation key to use for file io in @c log_file */
  PSI_file_key m_log_file_key;
#endif
};

class MYSQL_QUERY_LOG: public MYSQL_LOG
{
public:
  MYSQL_QUERY_LOG() : last_time(0) {}
  void reopen_file();
  bool write(time_t event_time, const char *user_host,
             uint user_host_len, int thread_id,
             const char *command_type, uint command_type_len,
             const char *sql_text, uint sql_text_len);
  bool write(THD *thd, time_t current_time, time_t query_start_arg,
             const char *user_host, uint user_host_len,
             ulonglong query_utime, ulonglong lock_utime, bool is_command,
             const char *sql_text, uint sql_text_len);
  bool open_slow_log(const char *log_name)
  {
    char buf[FN_REFLEN];
    return open(
#ifdef HAVE_PSI_INTERFACE
                key_file_slow_log,
#endif
                generate_name(log_name, "-slow.log", 0, buf),
                LOG_NORMAL, 0, WRITE_CACHE);
  }
  bool open_query_log(const char *log_name)
  {
    char buf[FN_REFLEN];
    return open(
#ifdef HAVE_PSI_INTERFACE
                key_file_query_log,
#endif
                generate_name(log_name, ".log", 0, buf),
                LOG_NORMAL, 0, WRITE_CACHE);
  }

private:
  time_t last_time;
};

class MYSQL_BIN_LOG: public TC_LOG, private MYSQL_LOG
{
 private:
#ifdef HAVE_PSI_INTERFACE
  /** The instrumentation key to use for @ LOCK_index. */
  PSI_mutex_key m_key_LOCK_index;
  /** The instrumentation key to use for @ update_cond. */
  PSI_cond_key m_key_update_cond;
  /** The instrumentation key to use for opening the log file. */
  PSI_file_key m_key_file_log;
  /** The instrumentation key to use for opening the log index file. */
  PSI_file_key m_key_file_log_index;
#endif
  /* LOCK_log and LOCK_index are inited by init_pthread_objects() */
  mysql_mutex_t LOCK_index;
  mysql_mutex_t LOCK_prep_xids;
  mysql_cond_t  COND_prep_xids;
  mysql_cond_t update_cond;
  ulonglong bytes_written;
  IO_CACHE index_file;
  char index_file_name[FN_REFLEN];
  /*
    purge_file is a temp file used in purge_logs so that the index file
    can be updated before deleting files from disk, yielding better crash
    recovery. It is created on demand the first time purge_logs is called
    and then reused for subsequent calls. It is cleaned up in cleanup().
  */
  IO_CACHE purge_index_file;
  char purge_index_file_name[FN_REFLEN];
  /*
     The max size before rotation (usable only if log_type == LOG_BIN: binary
     logs and relay logs).
     For a binlog, max_size should be max_binlog_size.
     For a relay log, it should be max_relay_log_size if this is non-zero,
     max_binlog_size otherwise.
     max_size is set in init(), and dynamically changed (when one does SET
     GLOBAL MAX_BINLOG_SIZE|MAX_RELAY_LOG_SIZE) by fix_max_binlog_size and
     fix_max_relay_log_size).
  */
  ulong max_size;
  long prepared_xids; /* for tc log - number of xids to remember */
  // current file sequence number for load data infile binary logging
  uint file_id;
  uint open_count;				// For replication
  int readers_count;
  bool need_start_event;
  /*
    no_auto_events means we don't want any of these automatic events :
    Start/Rotate/Stop. That is, in 4.x when we rotate a relay log, we don't
    want a Rotate_log event to be written to the relay log. When we start a
    relay log etc. So in 4.x this is 1 for relay logs, 0 for binlogs.
    In 5.0 it's 0 for relay logs too!
  */
  bool no_auto_events;

  /* pointer to the sync period variable, for binlog this will be
     sync_binlog_period, for relay log this will be
     sync_relay_log_period
  */
  uint *sync_period_ptr;
  uint sync_counter;

  inline uint get_sync_period()
  {
    return *sync_period_ptr;
  }

  int write_to_file(IO_CACHE *cache);
  /*
    This is used to start writing to a new log file. The difference from
    new_file() is locking. new_file_without_locking() does not acquire
    LOCK_log.
  */
  int new_file_without_locking();
  int new_file_impl(bool need_lock);

public:
  using MYSQL_LOG::generate_name;
  using MYSQL_LOG::is_open;

  /* This is relay log */
  bool is_relay_log;
  ulong signal_cnt;  // update of the counter is checked by heartbeat
  /*
    These describe the log's format. This is used only for relay logs.
    _for_exec is used by the SQL thread, _for_queue by the I/O thread. It's
    necessary to have 2 distinct objects, because the I/O thread may be reading
    events in a different format from what the SQL thread is reading (consider
    the case of a master which has been upgraded from 5.0 to 5.1 without doing
    RESET MASTER, or from 4.x to 5.0).
  */
  Format_description_log_event *description_event_for_exec,
    *description_event_for_queue;

  MYSQL_BIN_LOG(uint *sync_period);
  /*
    note that there's no destructor ~MYSQL_BIN_LOG() !
    The reason is that we don't want it to be automatically called
    on exit() - but only during the correct shutdown process
  */

#ifdef HAVE_PSI_INTERFACE
  void set_psi_keys(PSI_mutex_key key_LOCK_index,
                    PSI_cond_key key_update_cond,
                    PSI_file_key key_file_log,
                    PSI_file_key key_file_log_index)
  {
    m_key_LOCK_index= key_LOCK_index;
    m_key_update_cond= key_update_cond;
    m_key_file_log= key_file_log;
    m_key_file_log_index= key_file_log_index;
  }
#endif

  int open(const char *opt_name);
  void close();
  int log_xid(THD *thd, my_xid xid);
  int unlog(ulong cookie, my_xid xid);
  int recover(IO_CACHE *log, Format_description_log_event *fdle);
#if !defined(MYSQL_CLIENT)

  int flush_and_set_pending_rows_event(THD *thd, Rows_log_event* event,
                                       bool is_transactional);
  int remove_pending_rows_event(THD *thd, bool is_transactional);

#endif /* !defined(MYSQL_CLIENT) */
  void reset_bytes_written()
  {
    bytes_written = 0;
  }
  void harvest_bytes_written(ulonglong* counter)
  {
#ifndef DBUG_OFF
    char buf1[22],buf2[22];
#endif
    DBUG_ENTER("harvest_bytes_written");
    (*counter)+=bytes_written;
    DBUG_PRINT("info",("counter: %s  bytes_written: %s", llstr(*counter,buf1),
		       llstr(bytes_written,buf2)));
    bytes_written=0;
    DBUG_VOID_RETURN;
  }
  void set_max_size(ulong max_size_arg);
  void signal_update();
  void wait_for_update_relay_log(THD* thd);
  int  wait_for_update_bin_log(THD* thd, const struct timespec * timeout);
  void set_need_start_event() { need_start_event = 1; }
  void init(bool no_auto_events_arg, ulong max_size);
  void init_pthread_objects();
  void cleanup();
  bool open(const char *log_name,
            enum_log_type log_type,
            const char *new_name,
	    enum cache_type io_cache_type_arg,
	    bool no_auto_events_arg, ulong max_size,
            bool null_created,
            bool need_mutex);
  bool open_index_file(const char *index_file_name_arg,
                       const char *log_name, bool need_mutex);
  /* Use this to start writing a new log file */
  int new_file();

  bool write(Log_event* event_info); // binary log write
  bool write(THD *thd, IO_CACHE *cache, Log_event *commit_event, bool incident);
  bool write_incident(THD *thd, bool lock);

  int  write_cache(IO_CACHE *cache, bool lock_log, bool flush_and_sync);
  void set_write_error(THD *thd, bool is_transactional);
  bool check_write_error(THD *thd);

  void start_union_events(THD *thd, query_id_t query_id_param);
  void stop_union_events(THD *thd);
  bool is_query_in_union(THD *thd, query_id_t query_id_param);

  /*
    v stands for vector
    invoked as appendv(buf1,len1,buf2,len2,...,bufn,lenn,0)
  */
  bool appendv(const char* buf,uint len,...);
  bool append(Log_event* ev);

  void make_log_name(char* buf, const char* log_ident);
  bool is_active(const char* log_file_name);
  int update_log_index(LOG_INFO* linfo, bool need_update_threads);
  int rotate(bool force_rotate, bool* check_purge);
  void purge();
  int rotate_and_purge(bool force_rotate);
  /**
     Flush binlog cache and synchronize to disk.

     This function flushes events in binlog cache to binary log file,
     it will do synchronizing according to the setting of system
     variable 'sync_binlog'. If file is synchronized, @c synced will
     be set to 1, otherwise 0.

     @param[out] synced if not NULL, set to 1 if file is synchronized, otherwise 0

     @retval 0 Success
     @retval other Failure
  */
  bool flush_and_sync(bool *synced);
  int purge_logs(const char *to_log, bool included,
                 bool need_mutex, bool need_update_threads,
                 ulonglong *decrease_log_space);
  int purge_logs_before_date(time_t purge_time);
  int purge_first_log(Relay_log_info* rli, bool included);
  int set_purge_index_file_name(const char *base_file_name);
  int open_purge_index_file(bool destroy);
  bool is_inited_purge_index_file();
  int close_purge_index_file();
  int clean_purge_index_file();
  int sync_purge_index_file();
  int register_purge_index_entry(const char* entry);
  int register_create_index_entry(const char* entry);
  int purge_index_entry(THD *thd, ulonglong *decrease_log_space,
                        bool need_mutex);
  bool reset_logs(THD* thd);
  void close(uint exiting);

  // iterating through the log index file
  int find_log_pos(LOG_INFO* linfo, const char* log_name,
		   bool need_mutex);
  int find_next_log(LOG_INFO* linfo, bool need_mutex);
  int get_current_log(LOG_INFO* linfo);
  int raw_get_current_log(LOG_INFO* linfo);
  uint next_file_id();
  inline char* get_index_fname() { return index_file_name;}
  inline char* get_log_fname() { return log_file_name; }
  inline char* get_name() { return name; }
  inline mysql_mutex_t* get_log_lock() { return &LOCK_log; }
  inline mysql_cond_t* get_log_cond() { return &update_cond; }
  inline IO_CACHE* get_log_file() { return &log_file; }

  inline void lock_index() { mysql_mutex_lock(&LOCK_index);}
  inline void unlock_index() { mysql_mutex_unlock(&LOCK_index);}
  inline IO_CACHE *get_index_file() { return &index_file;}
  inline uint32 get_open_count() { return open_count; }
};

class Log_event_handler
{
public:
  Log_event_handler() {}
  virtual bool init()= 0;
  virtual void cleanup()= 0;

  virtual bool log_slow(THD *thd, time_t current_time,
                        time_t query_start_arg, const char *user_host,
                        uint user_host_len, ulonglong query_utime,
                        ulonglong lock_utime, bool is_command,
                        const char *sql_text, uint sql_text_len)= 0;
  virtual bool log_error(enum loglevel level, const char *format,
                         va_list args)= 0;
  virtual bool log_general(THD *thd, time_t event_time, const char *user_host,
                           uint user_host_len, int thread_id,
                           const char *command_type, uint command_type_len,
                           const char *sql_text, uint sql_text_len,
                           CHARSET_INFO *client_cs)= 0;
  virtual ~Log_event_handler() {}
};


int check_if_log_table(size_t db_len, const char *db, size_t table_name_len,
                       const char *table_name, bool check_if_opened);

class Log_to_csv_event_handler: public Log_event_handler
{
  friend class LOGGER;

public:
  Log_to_csv_event_handler();
  ~Log_to_csv_event_handler();
  virtual bool init();
  virtual void cleanup();

  virtual bool log_slow(THD *thd, time_t current_time,
                        time_t query_start_arg, const char *user_host,
                        uint user_host_len, ulonglong query_utime,
                        ulonglong lock_utime, bool is_command,
                        const char *sql_text, uint sql_text_len);
  virtual bool log_error(enum loglevel level, const char *format,
                         va_list args);
  virtual bool log_general(THD *thd, time_t event_time, const char *user_host,
                           uint user_host_len, int thread_id,
                           const char *command_type, uint command_type_len,
                           const char *sql_text, uint sql_text_len,
                           CHARSET_INFO *client_cs);

  int activate_log(THD *thd, uint log_type);
};


/* type of the log table */
#define QUERY_LOG_SLOW 1
#define QUERY_LOG_GENERAL 2

class Log_to_file_event_handler: public Log_event_handler
{
  MYSQL_QUERY_LOG mysql_log;
  MYSQL_QUERY_LOG mysql_slow_log;
  bool is_initialized;
public:
  Log_to_file_event_handler(): is_initialized(FALSE)
  {}
  virtual bool init();
  virtual void cleanup();

  virtual bool log_slow(THD *thd, time_t current_time,
                        time_t query_start_arg, const char *user_host,
                        uint user_host_len, ulonglong query_utime,
                        ulonglong lock_utime, bool is_command,
                        const char *sql_text, uint sql_text_len);
  virtual bool log_error(enum loglevel level, const char *format,
                         va_list args);
  virtual bool log_general(THD *thd, time_t event_time, const char *user_host,
                           uint user_host_len, int thread_id,
                           const char *command_type, uint command_type_len,
                           const char *sql_text, uint sql_text_len,
                           CHARSET_INFO *client_cs);
  void flush();
  void init_pthread_objects();
  MYSQL_QUERY_LOG *get_mysql_slow_log() { return &mysql_slow_log; }
  MYSQL_QUERY_LOG *get_mysql_log() { return &mysql_log; }
};


/* Class which manages slow, general and error log event handlers */
class LOGGER
{
  mysql_rwlock_t LOCK_logger;
  /* flag to check whether logger mutex is initialized */
  uint inited;

  /* available log handlers */
  Log_to_csv_event_handler *table_log_handler;
  Log_to_file_event_handler *file_log_handler;

  /* NULL-terminated arrays of log handlers */
  Log_event_handler *error_log_handler_list[MAX_LOG_HANDLERS_NUM + 1];
  Log_event_handler *slow_log_handler_list[MAX_LOG_HANDLERS_NUM + 1];
  Log_event_handler *general_log_handler_list[MAX_LOG_HANDLERS_NUM + 1];

public:

  bool is_log_tables_initialized;

  LOGGER() : inited(0), table_log_handler(NULL),
             file_log_handler(NULL), is_log_tables_initialized(FALSE)
  {}
  void lock_shared() { mysql_rwlock_rdlock(&LOCK_logger); }
  void lock_exclusive() { mysql_rwlock_wrlock(&LOCK_logger); }
  void unlock() { mysql_rwlock_unlock(&LOCK_logger); }
  bool is_log_table_enabled(uint log_table_type);
  bool log_command(THD *thd, enum enum_server_command command);

  /*
    We want to initialize all log mutexes as soon as possible,
    but we cannot do it in constructor, as safe_mutex relies on
    initialization, performed by MY_INIT(). This why this is done in
    this function.
  */
  void init_base();
  void init_log_tables();
  bool flush_logs(THD *thd);
  bool flush_slow_log();
  bool flush_general_log();
  /* Perform basic logger cleanup. this will leave e.g. error log open. */
  void cleanup_base();
  /* Free memory. Nothing could be logged after this function is called */
  void cleanup_end();
  bool error_log_print(enum loglevel level, const char *format,
                      va_list args);
  bool slow_log_print(THD *thd, const char *query, uint query_length,
                      ulonglong current_utime);
  bool general_log_print(THD *thd,enum enum_server_command command,
                         const char *format, va_list args);
  bool general_log_write(THD *thd, enum enum_server_command command,
                         const char *query, uint query_length);

  /* we use this function to setup all enabled log event handlers */
  int set_handlers(uint error_log_printer,
                   uint slow_log_printer,
                   uint general_log_printer);
  void init_error_log(uint error_log_printer);
  void init_slow_log(uint slow_log_printer);
  void init_general_log(uint general_log_printer);
  void deactivate_log_handler(THD* thd, uint log_type);
  bool activate_log_handler(THD* thd, uint log_type);
  MYSQL_QUERY_LOG *get_slow_log_file_handler() const
  {
    if (file_log_handler)
      return file_log_handler->get_mysql_slow_log();
    return NULL;
  }
  MYSQL_QUERY_LOG *get_log_file_handler() const
  {
    if (file_log_handler)
      return file_log_handler->get_mysql_log();
    return NULL;
  }
};

enum enum_binlog_format {
  BINLOG_FORMAT_MIXED= 0, ///< statement if safe, otherwise row - autodetected
  BINLOG_FORMAT_STMT=  1, ///< statement-based
  BINLOG_FORMAT_ROW=   2, ///< row-based
  BINLOG_FORMAT_UNSPEC=3  ///< thd_binlog_format() returns it when binlog is closed
};

int query_error_code(THD *thd, bool not_killed);
uint purge_log_get_error_code(int res);

int vprint_msg_to_log(enum loglevel level, const char *format, va_list args);
void sql_print_error(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
void sql_print_warning(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
void sql_print_information(const char *format, ...)
  ATTRIBUTE_FORMAT(printf, 1, 2);
typedef void (*sql_print_message_func)(const char *format, ...)
  ATTRIBUTE_FORMAT_FPTR(printf, 1, 2);
extern sql_print_message_func sql_print_message_handlers[];

int error_log_print(enum loglevel level, const char *format,
                    va_list args);

bool slow_log_print(THD *thd, const char *query, uint query_length,
                    ulonglong current_utime);

bool general_log_print(THD *thd, enum enum_server_command command,
                       const char *format,...);

bool general_log_write(THD *thd, enum enum_server_command command,
                       const char *query, uint query_length);

void sql_perror(const char *message);
bool flush_error_log();

File open_binlog(IO_CACHE *log, const char *log_file_name,
                 const char **errmsg);

char *make_log_name(char *buff, const char *name, const char* log_ext);

/**
  Check given log name against certain blacklisted names/extensions.

  @param name     Log name to check
  @param len      Length of log name

  @returns true if name is valid, false otherwise.
*/
bool is_valid_log_name(const char *name, size_t len);

extern MYSQL_PLUGIN_IMPORT MYSQL_BIN_LOG mysql_bin_log;
extern LOGGER logger;


/**
  Turns a relative log binary log path into a full path, based on the
  opt_bin_logname or opt_relay_logname.

  @param from         The log name we want to make into an absolute path.
  @param to           The buffer where to put the results of the
                      normalization.
  @param is_relay_log Switch that makes is used inside to choose which
                      option (opt_bin_logname or opt_relay_logname) to
                      use when calculating the base path.

  @returns true if a problem occurs, false otherwise.
 */

inline bool normalize_binlog_name(char *to, const char *from, bool is_relay_log)
{
  DBUG_ENTER("normalize_binlog_name");
  bool error= false;
  char buff[FN_REFLEN];
  char *ptr= (char*) from;
  char *opt_name= is_relay_log ? opt_relay_logname : opt_bin_logname;

  DBUG_ASSERT(from);

  /* opt_name is not null and not empty and from is a relative path */
  if (opt_name && opt_name[0] && from && !test_if_hard_path(from))
  {
    // take the path from opt_name
    // take the filename from from
    char log_dirpart[FN_REFLEN], log_dirname[FN_REFLEN];
    size_t log_dirpart_len, log_dirname_len;
    dirname_part(log_dirpart, opt_name, &log_dirpart_len);
    dirname_part(log_dirname, from, &log_dirname_len);

    /* log may be empty => relay-log or log-bin did not
        hold paths, just filename pattern */
    if (log_dirpart_len > 0)
    {
      /* create the new path name */
      if(fn_format(buff, from+log_dirname_len, log_dirpart, "",
                   MYF(MY_UNPACK_FILENAME | MY_SAFE_PATH)) == NULL)
      {
        error= true;
        goto end;
      }

      ptr= buff;
    }
  }

  DBUG_ASSERT(ptr);

  if (ptr)
    strmake(to, ptr, strlen(ptr));

end:
  DBUG_RETURN(error);
}


#endif /* LOG_H */