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Updated file to use doxygen commenting style.

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trudy@linux.site 2006-12-18 14:28:15 -08:00
parent b1d173f510
commit 7b74da641f
1 changed files with 151 additions and 57 deletions
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208
storage/example/ha_example.h
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@ -14,20 +14,31 @@
along with this program; if not, write to the Free Software along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* /** @file ha_example.h
Please read ha_exmple.cc before reading this file.
Please keep in mind that the example storage engine implements all methods @brief
that are required to be implemented. handler.h has a full list of methods The ha_example engine is a stubbed storage engine for example purposes only;
that you can implement. it does nothing at this point. Its purpose is to provide a source
code illustration of how to begin writing new storage engines; see also
/storage/example/ha_example.cc.
@note
Please read ha_example.cc before reading this file.
Reminder: The example storage engine implements all methods that are *required*
to be implemented. For a full list of all methods that you can implement, see
handler.h.
@see
/sql/handler.h and /storage/example/ha_example.cc
*/ */
#ifdef USE_PRAGMA_INTERFACE #ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */ #pragma interface /* gcc class implementation */
#endif #endif
/* /** @brief
EXAMPLE_SHARE is a structure that will be shared amoung all open handlers EXAMPLE_SHARE is a structure that will be shared among all open handlers.
The example implements the minimum of what you will probably need. This example implements the minimum of what you will probably need.
*/ */
typedef struct st_example_share { typedef struct st_example_share {
char *table_name; char *table_name;
@ -36,117 +47,200 @@ typedef struct st_example_share {
THR_LOCK lock; THR_LOCK lock;
} EXAMPLE_SHARE; } EXAMPLE_SHARE;
/* /** @brief
Class definition for the storage engine Class definition for the storage engine
*/ */
class ha_example: public handler class ha_example: public handler
{ {
THR_LOCK_DATA lock; /* MySQL lock */ THR_LOCK_DATA lock; ///< MySQL lock
EXAMPLE_SHARE *share; /* Shared lock info */ EXAMPLE_SHARE *share; ///< Shared lock info
public: public:
ha_example(handlerton *hton, TABLE_SHARE *table_arg); ha_example(handlerton *hton, TABLE_SHARE *table_arg);
~ha_example() ~ha_example()
{ {
} }
/* The name that will be used for display purposes */
/** @brief
The name that will be used for display purposes.
*/
const char *table_type() const { return "EXAMPLE"; } const char *table_type() const { return "EXAMPLE"; }
/*
The name of the index type that will be used for display /** @brief
don't implement this method unless you really have indexes The name of the index type that will be used for display.
Don't implement this method unless you really have indexes.
*/ */
const char *index_type(uint inx) { return "HASH"; } const char *index_type(uint inx) { return "HASH"; }
/** @brief
The file extensions.
*/
const char **bas_ext() const; const char **bas_ext() const;
/*
This is a list of flags that says what the storage engine /** @brief
implements. The current table flags are documented in This is a list of flags that indicate what functionality the storage engine
handler.h implements. The current table flags are documented in handler.h
*/ */
ulonglong table_flags() const ulonglong table_flags() const
{ {
return 0; return 0;
} }
/*
This is a bitmap of flags that says how the storage engine
implements indexes. The current index flags are documented in
handler.h. If you do not implement indexes, just return zero
here.
part is the key part to check. First key part is 0 /** @brief
If all_parts it's set, MySQL want to know the flags for the combined This is a bitmap of flags that indicates how the storage engine
index up to and including 'part'. implements indexes. The current index flags are documented in
handler.h. If you do not implement indexes, just return zero here.
@details
part is the key part to check. First key part is 0.
If all_parts is set, MySQL wants to know the flags for the combined
index, up to and including 'part'.
*/ */
ulong index_flags(uint inx, uint part, bool all_parts) const ulong index_flags(uint inx, uint part, bool all_parts) const
{ {
return 0; return 0;
} }
/*
unireg.cc will call the following to make sure that the storage engine can
handle the data it is about to send.
Return *real* limits of your storage engine here. MySQL will do /** @brief
min(your_limits, MySQL_limits) automatically unireg.cc will call max_supported_record_length(), max_supported_keys(),
max_supported_key_parts(), uint max_supported_key_length()
There is no need to implement ..._key_... methods if you don't suport to make sure that the storage engine can handle the data it is about to
indexes. send. Return *real* limits of your storage engine here; MySQL will do
*/ min(your_limits, MySQL_limits) automatically.
*/
uint max_supported_record_length() const { return HA_MAX_REC_LENGTH; } uint max_supported_record_length() const { return HA_MAX_REC_LENGTH; }
/** @brief
unireg.cc will call this to make sure that the storage engine can handle
the data it is about to send. Return *real* limits of your storage engine
here; MySQL will do min(your_limits, MySQL_limits) automatically.
@details
There is no need to implement ..._key_... methods if your engine doesn't
support indexes.
*/
uint max_supported_keys() const { return 0; } uint max_supported_keys() const { return 0; }
/** @brief
unireg.cc will call this to make sure that the storage engine can handle
the data it is about to send. Return *real* limits of your storage engine
here; MySQL will do min(your_limits, MySQL_limits) automatically.
@details
There is no need to implement ..._key_... methods if your engine doesn't
support indexes.
*/
uint max_supported_key_parts() const { return 0; } uint max_supported_key_parts() const { return 0; }
/** @brief
unireg.cc will call this to make sure that the storage engine can handle
the data it is about to send. Return *real* limits of your storage engine
here; MySQL will do min(your_limits, MySQL_limits) automatically.
@details
There is no need to implement ..._key_... methods if your engine doesn't
support indexes.
*/
uint max_supported_key_length() const { return 0; } uint max_supported_key_length() const { return 0; }
/*
/** @brief
Called in test_quick_select to determine if indexes should be used. Called in test_quick_select to determine if indexes should be used.
*/ */
virtual double scan_time() { return (double) (stats.records+stats.deleted) / 20.0+10; } virtual double scan_time() { return (double) (stats.records+stats.deleted) / 20.0+10; }
/*
The next method will never be called if you do not implement indexes. /** @brief
This method will never be called if you do not implement indexes.
*/ */
virtual double read_time(ha_rows rows) { return (double) rows / 20.0+1; } virtual double read_time(ha_rows rows) { return (double) rows / 20.0+1; }
/* /*
Everything below are methods that we implment in ha_example.cc. Everything below are methods that we implement in ha_example.cc.
Most of these methods are not obligatory, skip them and Most of these methods are not obligatory, skip them and
MySQL will treat them as not implemented MySQL will treat them as not implemented
*/ */
/** @brief
We implement this in ha_example.cc; it's a required method.
*/
int open(const char *name, int mode, uint test_if_locked); // required int open(const char *name, int mode, uint test_if_locked); // required
/** @brief
We implement this in ha_example.cc; it's a required method.
*/
int close(void); // required int close(void); // required
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int write_row(byte * buf); int write_row(byte * buf);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int update_row(const byte * old_data, byte * new_data); int update_row(const byte * old_data, byte * new_data);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int delete_row(const byte * buf); int delete_row(const byte * buf);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int index_read(byte * buf, const byte * key, int index_read(byte * buf, const byte * key,
uint key_len, enum ha_rkey_function find_flag); uint key_len, enum ha_rkey_function find_flag);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int index_next(byte * buf); int index_next(byte * buf);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int index_prev(byte * buf); int index_prev(byte * buf);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int index_first(byte * buf); int index_first(byte * buf);
/** @brief
We implement this in ha_example.cc. It's not an obligatory method;
skip it and and MySQL will treat it as not implemented.
*/
int index_last(byte * buf); int index_last(byte * buf);
/*
unlike index_init(), rnd_init() can be called two times /** @brief
without rnd_end() in between (it only makes sense if scan=1). Unlike index_init(), rnd_init() can be called two consecutive times
then the second call should prepare for the new table scan without rnd_end() in between (it only makes sense if scan=1). In this
(e.g if rnd_init allocates the cursor, second call should case, the second call should prepare for the new table scan (e.g if
position it to the start of the table, no need to deallocate rnd_init() allocates the cursor, the second call should position the
and allocate it again cursor to the start of the table; no need to deallocate and allocate
it again. This is a required method.
*/ */
int rnd_init(bool scan); //required int rnd_init(bool scan); //required
int rnd_end(); int rnd_end();
int rnd_next(byte *buf); //required int rnd_next(byte *buf); ///< required
int rnd_pos(byte * buf, byte *pos); //required int rnd_pos(byte * buf, byte *pos); ///< required
void position(const byte *record); //required void position(const byte *record); ///< required
int info(uint); //required int info(uint); ///< required
int extra(enum ha_extra_function operation); int extra(enum ha_extra_function operation);
int external_lock(THD *thd, int lock_type); //required int external_lock(THD *thd, int lock_type); ///< required
int delete_all_rows(void); int delete_all_rows(void);
ha_rows records_in_range(uint inx, key_range *min_key, ha_rows records_in_range(uint inx, key_range *min_key,
key_range *max_key); key_range *max_key);
int delete_table(const char *from); int delete_table(const char *from);
int rename_table(const char * from, const char * to); int rename_table(const char * from, const char * to);
int create(const char *name, TABLE *form, int create(const char *name, TABLE *form,
HA_CREATE_INFO *create_info); //required HA_CREATE_INFO *create_info); ///< required
THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to, THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
enum thr_lock_type lock_type); //required enum thr_lock_type lock_type); ///< required
};