maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Nikita!

On Nov 12, Nikita Malyavin wrote:
> revision-id: 4af7a583802 (mariadb-10.5.2-474-g4af7a583802)
> parent(s): 2da3dc5d422
> author: Nikita Malyavin
> committer: Nikita Malyavin
> timestamp: 2021-01-08 20:59:09 +1000
> message:
> 
> Refactor MYSQL_BIN_LOG: extract Event_log ancestor

Would be good to have some explanation here. I understand that you'll
use this refactoring in following commits, but conceptually, what Event_log is?

I mean, like

  Event_log is a log where Log_event_xxx events are written, but not
  _something else that MYSQL_BIN_LOG is and Event_log isn't_

or

  Event_log is a log where Log_event_xxx events are written. While
  MYSQL_BIN_LOG is Event_log that also does ....

> diff --git a/sql/log.cc b/sql/log.cc
> index 827a34c2883..6f4e3191588 100644
> --- a/sql/log.cc
> +++ b/sql/log.cc
> @@ -3701,64 +3765,25 @@ bool MYSQL_BIN_LOG::open(const char *log_name,
>        write_file_name_to_index_file= 1;
>      }

a bit strange that MYSQL_BIN_LOG::open doesn't use Event_log::open

> diff --git a/sql/log.h b/sql/log.h
> index 73cd66d5a4a..74c409e1ac7 100644
> --- a/sql/log.h
> +++ b/sql/log.h
> @@ -327,6 +327,7 @@ class MYSQL_LOG
>                              bool strip_ext, char *buff);
>    virtual int generate_new_name(char *new_name, const char *log_name,
>                                  ulong next_log_number);
> +  inline mysql_mutex_t* get_log_lock() { return &LOCK_log; }
>   protected:
>    /* LOCK_log is inited by init_pthread_objects() */
>    mysql_mutex_t LOCK_log;
> @@ -376,6 +377,64 @@ struct Rows_event_factory
>    }
>  };
>  
> +class Event_log: public MYSQL_LOG
> +{
> +public:
> +#if !defined(MYSQL_CLIENT)
> +  Rows_log_event*
> +  prepare_pending_rows_event(THD *thd, TABLE* table,
> +                             binlog_cache_data *cache_data,
> +                             uint32 serv_id, size_t needed,
> +                             bool is_transactional,
> +                             Rows_event_factory event_factory);

forgot to delete the same from MYSQL_BIN_LOG

> +#endif
> +
> +  bool flush_and_sync(bool *synced);

same

> +  void cleanup()
> +  {
> +    if (inited)
> +      mysql_mutex_destroy(&LOCK_binlog_end_pos);
> +
> +    MYSQL_LOG::cleanup();
> +  }
> +  void init_pthread_objects()
> +  {
> +    MYSQL_LOG::init_pthread_objects();
> +
> +    mysql_mutex_init(m_key_LOCK_binlog_end_pos, &LOCK_binlog_end_pos,
> +                     MY_MUTEX_INIT_SLOW);
> +  }
> +
> +  bool open(
> +          const char *log_name,
> +          enum_log_type log_type,
> +          const char *new_name, ulong next_file_number,
> +          enum cache_type io_cache_type_arg);
> +  IO_CACHE *get_log_file() { return &log_file; }
> +
> +  int write_description_event(enum_binlog_checksum_alg checksum_alg,
> +                              bool encrypt, bool dont_set_created);
> +
> +  bool write_event(Log_event *ev, binlog_cache_data *data, IO_CACHE *file);
> +};
> +
>  /* Tell the io thread if we can delay the master info sync. */
>  #define SEMI_SYNC_SLAVE_DELAY_SYNC 1
>  /* Tell the io thread if the current event needs a ack. */
> @@ -451,7 +510,7 @@ class binlog_cache_data;
>  struct rpl_gtid;
>  struct wait_for_commit;
>  
> -class MYSQL_BIN_LOG: public TC_LOG, private MYSQL_LOG
> +class MYSQL_BIN_LOG: public TC_LOG, private Event_log
>  {
>    /** The instrumentation key to use for @ LOCK_index. */
>    PSI_mutex_key m_key_LOCK_index;
> @@ -849,15 +901,13 @@ class MYSQL_BIN_LOG: public TC_LOG, private MYSQL_LOG
>  
> -  bool write_event(Log_event *ev, binlog_cache_data *data, IO_CACHE *file);
> +  bool write_event(Log_event *ev, binlog_cache_data *data, IO_CACHE *file)
> +  { return Event_log::write_event(ev, data, file); }

Perhaps

    using Event_log::write_event(Log_event *ev, binlog_cache_data *data, IO_CACHE *file);

?

>    bool write_event(Log_event *ev) { return write_event(ev, 0, &log_file); }
>  
>    bool write_event_buffer(uchar* buf,uint len);
> @@ -918,7 +968,6 @@ class MYSQL_BIN_LOG: public TC_LOG, private MYSQL_LOG
>    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; }

should remove that too, I reckon

>    inline mysql_cond_t* get_bin_log_cond() { return &COND_bin_log_updated; }
>    inline IO_CACHE* get_log_file() { return &log_file; }

Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx