Commit 94ab2caa authored by unknown's avatar unknown
Browse files

documenting HA_STATUS_xxx flags

parent e69de4f6

include/my_base.h

+42 −9
Original line number Diff line number Diff line
@@ -260,14 +260,47 @@ enum ha_base_keytype { 
#define HA_CREATE_CHECKSUM	8

#define HA_CREATE_DELAY_KEY_WRITE 64



	/* Bits in flag to _status */

/*

  The following flags (OR-ed) are passed to handler::info() method.

  The method copies misc handler information out of the storage engine

  to data structures accessible from MySQL



  Same flags are also passed down to mi_status, myrg_status, etc.

*/



#define HA_STATUS_POS		1		/* Return position */

#define HA_STATUS_NO_LOCK	2		/* Don't use external lock */

#define HA_STATUS_TIME		4		/* Return update time */

#define HA_STATUS_CONST		8		/* Return constants values */

/* this one is not used */

#define HA_STATUS_POS            1

/*

  assuming the table keeps shared actual copy of the 'info' and

  local, possibly outdated copy, the following flag means that

  it should not try to get the actual data (locking the shared structure)

  slightly outdated version will suffice

*/

#define HA_STATUS_NO_LOCK        2

/* update the time of the last modification (in handler::update_time) */

#define HA_STATUS_TIME           4

/*

  update the 'constant' part of the info:

  handler::max_data_file_length, max_index_file_length, create_time

  sortkey, ref_length, block_size, data_file_name, index_file_name.

  handler::table->s->keys_in_use, keys_for_keyread, rec_per_key

*/

#define HA_STATUS_CONST          8

/*

  update the 'variable' part of the info:

  handler::records, deleted, data_file_length, index_file_length,

  delete_length, check_time, mean_rec_length

*/

#define HA_STATUS_VARIABLE      16

/*

  get the information about the key that caused last duplicate value error

  update handler::errkey and handler::dupp_ref

  see handler::get_dup_key()

*/

#define HA_STATUS_ERRKEY        32

/*

  update handler::auto_increment_value

*/

#define HA_STATUS_AUTO          64



	/* Errorcodes given by functions */

sql/examples/ha_example.cc

+2 −0
Original line number Diff line number Diff line
@@ -480,6 +480,8 @@ int ha_example::rnd_pos(byte * buf, byte *pos) 


/*

  ::info() is used to return information to the optimizer.

  see my_base.h for the complete description



  Currently this table handler doesn't implement most of the fields

  really needed. SHOW also makes use of this data

  Another note, you will probably want to have the following in your

sql/handler.h

+1 −1
Original line number Diff line number Diff line
@@ -672,7 +672,7 @@ class handler :public Sql_alloc 
                                   key_range *max_key)

    { return (ha_rows) 10; }

  virtual void position(const byte *record)=0;

  virtual void info(uint)=0;

  virtual void info(uint)=0; // see my_base.h for full description

  virtual int extra(enum ha_extra_function operation)

  { return 0; }

  virtual int extra_opt(enum ha_extra_function operation, ulong cache_size)