mariadb/strings/strxnmov.c
monty@mysql.com e42c980967 Table definition cache, part 2
The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
  object and open a handler to the table object

Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it

- For a busy system this change will give you:
 - Less memory usage for table object
 - Faster opening of tables (if it's has been in use or is in table definition cache)
 - Allow you to cache many table definitions objects
 - Faster drop of table
2005-11-23 22:45:02 +02:00

63 lines
2 KiB
C

/* Copyright (C) 2002 MySQL AB
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA */
/* File : strxnmov.c
Author : Richard A. O'Keefe.
Updated: 2 June 1984
Defines: strxnmov()
strxnmov(dst, len, src1, ..., srcn, NullS)
moves the first len characters of the concatenation of src1,...,srcn
to dst and add a closing NUL character.
It is just like strnmov except that it concatenates multiple sources.
Beware: the last argument should be the null character pointer.
Take VERY great care not to omit it! Also be careful to use NullS
and NOT to use 0, as on some machines 0 is not the same size as a
character pointer, or not the same bit pattern as NullS.
NOTE
strxnmov is like strnmov in that it moves up to len
characters; dst will be padded on the right with one '\0' character.
if total-string-length >= length then dst[length] will be set to \0
*/
#include <my_global.h>
#include "m_string.h"
#include <stdarg.h>
char *strxnmov(char *dst,uint len, const char *src, ...)
{
va_list pvar;
char *end_of_dst=dst+len;
va_start(pvar,src);
while (src != NullS)
{
do
{
if (dst == end_of_dst)
goto end;
}
while ((*dst++ = *src++));
dst--;
src = va_arg(pvar, char *);
}
end:
*dst=0;
va_end(pvar);
return dst;
}