maria-developers team mailing list archive

[Nikita Malyavin <nikitamalyavin@xxxxxxxxx>]

The changes to this commit are secured in 15fe904d3
<https://github.com/MariaDB/server/commit/15fe904d3fd4583f1966c8a7ab6ff36111f1f920>
 fixup

On Tue, 23 Nov 2021 at 22:54, Nikita Malyavin <nikitamalyavin@xxxxxxxxx>
wrote:

> Hello Serg!
>
> TLDR the commit is verbalized, junks are removed, `using` is preferred
> except for tiny getters.
>
> On Fri, 12 Nov 2021 at 19:20, Sergei Golubchik <serg@xxxxxxxxxxx> wrote:
>
>> 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 ....
>>
> Right. Adding as follows:
>
> Event_log is supposed to be a basic logging class that can write events in
> a single file.
>
>
> MYSQL_BIN_LOG in comparison will have:
> * rotation support
> * index files
> * purging
> * gtid, xid and other transactional information handling.
> * is dedicated for a general-purpose binlog
>
>
>
>>
>> > 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
>>
> Yes, I think MYSQL_BIN_LOG is left too specialized for some particular
> needs. I did not want to touch all that tech debt and left as is.
>
> Besides, there's nothing weird in not calling the superclass's method.
>
> I mean, in future commits [spoiler alert!] it will be used anyway:)
>
>>
>> > 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
>
> wow, i wonder how did you notice.
>
>>
>
>
>> > +  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);
>>
>> ?
>>
> Indeed:)
>
>>
>> >    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
>>
> Well, these are so tiny getters so I'm not sure, whether is it more
> comfortable to jump back and forth to check what's there in Event_log, or
> just admit the cost of duplication for a better read comfort. I'd leave it
> as it is now.
>
>>
>> >    inline mysql_cond_t* get_bin_log_cond() { return
>> &COND_bin_log_updated; }
>> >    inline IO_CACHE* get_log_file() { return &log_file; }
>
>
> --
> Yours truly,
> Nikita Malyavin
>


-- 
Yours truly,
Nikita Malyavin