database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-07 00:04:31 +03:00
Code Activity

Updated documentation of how to add new native functions.

Browse Source 
Small cleanups


Docs/manual.texi:
  Updated how to add new native functions
mysql-test/r/func_crypt.result:
  Fix for crypt on FreeBSD
mysql-test/t/func_crypt.test:
  Fix for crypt on FreeBSD
mysys/thr_lock.c:
  Changed to use statistics_increment macro for statistic variables.
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted
This commit is contained in:
unknown
2001-05-23 02:30:17 +03:00
parent 112ad67205
commit 36b93f91db
5 changed files with 52 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
BitKeeper/etc/logging_ok
View File

@@ -1,6 +1 @@
mwagner@evoq.mwagner.org
tim@threads.polyesthetic.msg
tim@work.mysql.com
heikki@donna.mysql.fi
paul@central.snake.net
monty@donna.mysql.fi
monty@tik.mysql.fi

59
Docs/manual.texi
View File

@@ -10361,7 +10361,7 @@ feature).
Ignore the @code{delay_key_write} option for all tables.
@xref{Server parameters}.
@item -Sg, --skip-grant-tables
@item --skip-grant-tables
This option causes the server not to use the privilege system at all. This
gives everyone @emph{full access} to all databases! (You can tell a running
server to start using the grant tables again by executing @code{mysqladmin
@@ -35307,12 +35307,20 @@ To add a new native @strong{MySQL} function, follow these steps:
Add one line to @file{lex.h} that defines the function name in the
@code{sql_functions[]} array.
@item
Add two lines to @file{sql_yacc.yy}. One indicates the preprocessor
symbol that @code{yacc} should define (this should be added at the
beginning of the file). Then define the function parameters and add an
``item'' with these parameters to the @code{simple_expr} parsing rule.
For an example, check all occurrences of @code{SOUNDEX} in
@file{sql_yacc.yy} to see how this is done.
If the function prototype is simple (just takes zero, one, two or three
arguments), you should in lex.h specify SYM(FUNC_ARG#) (where # is the
number of arguments) as the second argument in the
@code{sql_functions[]} array and add a function that creates a function
object in @file{item_create.cc}. Take a look at @code{"ABS"} and
@code{create_funcs_abs()} for an example of this.
If the function prototype is complicated (for example takes a variable number
of arguments), you should add two lines to @file{sql_yacc.yy}. One
indicates the preprocessor symbol that @code{yacc} should define (this
should be added at the beginning of the file). Then define the function
parameters and add an ``item'' with these parameters to the
@code{simple_expr} parsing rule. For an example, check all occurrences
of @code{ATAN} in @file{sql_yacc.yy} to see how this is done.
@item
In @file{item_func.h}, declare a class inheriting from @code{Item_num_func} or
@code{Item_str_func}, depending on whether your function returns a number or a
@@ -35325,28 +35333,45 @@ double Item_func_newname::val()
longlong Item_func_newname::val_int()
String *Item_func_newname::Str(String *str)
@end example
If you inherit your object from any of the standard items (like
@code{Item_num_func} you probably only have to define one of the above
functions and let the parent object take care of the other functions.
For example, the @code{Item_str_func} class defines a @code{val()} function
that executes @code{atof()} on the value returned by @code{::str()}.
@item
You should probably also define the following function:
You should probably also define the following object function:
@example
void Item_func_newname::fix_length_and_dec()
@end example
This function should at least calculate @code{max_length} based on the
given arguments. @code{max_length} is the maximum number of characters
the function may return. This function should also set @code{maybe_null = 0}
if the main function can't return a @code{NULL} value. The function can check
if any of the function arguments can return @code{NULL} by checking the
arguments @code{maybe_null} variable.
the function may return. This function should also set @code{maybe_null
= 0} if the main function can't return a @code{NULL} value. The
function can check if any of the function arguments can return
@code{NULL} by checking the arguments @code{maybe_null} variable. You
can take a look at @code{Item_func_mod::fix_length_and_dec} for a
typical example of how to do this.
@end enumerate
All functions must be thread safe.
All functions must be thread safe (In other words, don't use any global or
static variables in the functions without protecting them with mutexes).
If you want to return @code{NULL}, from @code{::val()}, @code{::val_int()}
or @code{::str()} you should set @code{null_value} to 1 and return 0.
For @code{::str()} object functions, there are some additional
considerations to be aware of:
For string functions, there are some additional considerations to be aware of:
@itemize @bullet
@item
The @code{String *str} argument provides a string
buffer that may be used to hold the result.
The @code{String *str} argument provides a string buffer that may be
used to hold the result. (For more information about the @code{String} type,
take a look at the @file{sql_string.h} file.)
@item
The function should return the string that holds the result.
The @code{::str()} function should return the string that holds the result or
@code{(char*) 0} if the result is @code{NULL}.
@item
All current string functions try to avoid allocating any memory unless
absolutely necessary!

4
mysql-test/r/func_crypt.result
View File

@@ -1,2 +1,2 @@
encrypt('foo', 'ff')
ffTU0fyIP09Z.
length(encrypt('foo', 'ff')) <> 0
1

3
mysql-test/t/func_crypt.test
View File

@@ -1 +1,2 @@
select encrypt('foo', 'ff');
select length(encrypt('foo', 'ff')) <> 0;

10
mysys/thr_lock.c
View File

@@ -449,7 +449,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
check_locks(lock,"read lock with old write lock",0);
if (lock->get_status)
(*lock->get_status)(data->status_param);
++locks_immediate;
statistic_increment(locks_immediate,&THR_LOCK_lock);
goto end;
}
if (lock->write.data->type == TL_WRITE_ONLY)
@@ -473,7 +473,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
if ((int) lock_type == (int) TL_READ_NO_INSERT)
lock->read_no_write_count++;
check_locks(lock,"read lock with no write locks",0);
++locks_immediate;
statistic_increment(locks_immediate,&THR_LOCK_lock);
goto end;
}
/* Can't get lock yet; Wait for it */
@@ -505,7 +505,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
data->cond=get_cond();
if (lock->get_status)
(*lock->get_status)(data->status_param);
++locks_immediate;
statistic_increment(locks_immediate,&THR_LOCK_lock);
goto end;
}
}
@@ -540,7 +540,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
check_locks(lock,"second write lock",0);
if (data->lock->get_status)
(*data->lock->get_status)(data->status_param);
++locks_immediate;
statistic_increment(locks_immediate,&THR_LOCK_lock);
goto end;
}
DBUG_PRINT("lock",("write locked by thread: %ld",
@@ -566,7 +566,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
if (data->lock->get_status)
(*data->lock->get_status)(data->status_param);
check_locks(lock,"only write lock",0);
++locks_immediate;
statistic_increment(locks_immediate,&THR_LOCK_lock);
goto end;
}
}