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collision resolving

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unknown 2002-04-13 20:08:00 +03:00
commit b54d2759d9
4 changed files with 49 additions and 45 deletions
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39
include/my_alloc.h Normal file
View file

@ -0,0 +1,39 @@
/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
Data structures for mysys/my_alloc.c (root memory allocator)
*/
#ifndef ST_USED_MEM_DEFINED
#define ST_USED_MEM_DEFINED
typedef struct st_used_mem { /* struct for once_alloc (block) */
struct st_used_mem *next; /* Next block in use */
unsigned int left; /* memory left in block */
unsigned int size; /* size of block */
} USED_MEM;
typedef struct st_mem_root {
USED_MEM *free; /* blocks with free memory in it */
USED_MEM *used; /* blocks almost without free memory */
USED_MEM *pre_alloc; /* preallocated block */
/* if block have less memory it will be put in 'used' list*/
unsigned int min_malloc;
unsigned int block_size; /* initial block size */
unsigned int block_num; /* allocated blocks counter */
void (*error_handler)(void);
} MEM_ROOT;
#endif

21
include/my_sys.h
View file

@ -464,26 +464,7 @@ typedef struct st_changeable_var {
} CHANGEABLE_VAR;
/* structs for alloc_root */
#ifndef ST_USED_MEM_DEFINED
#define ST_USED_MEM_DEFINED
typedef struct st_used_mem { /* struct for once_alloc */
struct st_used_mem *next; /* Next block in use */
unsigned int left; /* memory left in block */
unsigned int size; /* Size of block */
} USED_MEM;
typedef struct st_mem_root {
USED_MEM *free;
USED_MEM *used;
USED_MEM *pre_alloc;
unsigned int min_malloc;
unsigned int block_size;
void (*error_handler)(void);
} MEM_ROOT;
#endif
#include "my_alloc.h"
/* Prototypes for mysys and my_func functions */

18
include/mysql.h
View file

@ -100,23 +100,7 @@ typedef struct st_mysql_rows {
typedef MYSQL_ROWS *MYSQL_ROW_OFFSET; /* offset to current row */
#ifndef ST_USED_MEM_DEFINED
#define ST_USED_MEM_DEFINED
typedef struct st_used_mem { /* struct for once_alloc */
struct st_used_mem *next; /* Next block in use */
unsigned int left; /* memory left in block */
unsigned int size; /* size of block */
} USED_MEM;
typedef struct st_mem_root {
USED_MEM *free;
USED_MEM *used;
USED_MEM *pre_alloc;
unsigned int min_malloc;
unsigned int block_size;
void (*error_handler)(void);
} MEM_ROOT;
#endif
#include "my_alloc.h"
typedef struct st_mysql_data {
my_ulonglong rows;

16
mysys/my_alloc.c
View file

@ -29,6 +29,7 @@ void init_alloc_root(MEM_ROOT *mem_root, uint block_size,
mem_root->min_malloc=32;
mem_root->block_size=block_size-MALLOC_OVERHEAD-sizeof(USED_MEM)-8;
mem_root->error_handler=0;
mem_root->block_num= 0;
#if !(defined(HAVE_purify) && defined(EXTRA_DEBUG))
if (pre_alloc_size)
{
@ -61,25 +62,20 @@ gptr alloc_root(MEM_ROOT *mem_root,unsigned int Size)
mem_root->used=next;
return (gptr) (((char*) next)+ALIGN_SIZE(sizeof(USED_MEM)));
#else
uint get_size,max_left;
uint get_size, block_size;
gptr point;
reg1 USED_MEM *next;
reg2 USED_MEM **prev;
Size= ALIGN_SIZE(Size);
prev= &mem_root->free;
max_left=0;
for (next= *prev ; next && next->left < Size ; next= next->next)
{
if (next->left > max_left)
max_left=next->left;
prev= &next->next;
}
if (! next)
{ /* Time to alloc new block */
block_size= mem_root->block_size*((mem_root->block_num>>2)+1);
get_size= Size+ALIGN_SIZE(sizeof(USED_MEM));
if (max_left*4 < mem_root->block_size && get_size < mem_root->block_size)
get_size=mem_root->block_size; /* Normal alloc */
get_size= max(get_size, block_size);
if (!(next = (USED_MEM*) my_malloc(get_size,MYF(MY_WME))))
{
@ -87,6 +83,7 @@ gptr alloc_root(MEM_ROOT *mem_root,unsigned int Size)
(*mem_root->error_handler)();
return((gptr) 0); /* purecov: inspected */
}
mem_root->block_num++;
next->next= *prev;
next->size= get_size;
next->left= get_size-ALIGN_SIZE(sizeof(USED_MEM));
@ -165,7 +162,10 @@ void free_root(MEM_ROOT *root, myf MyFlags)
root->free=root->pre_alloc;
root->free->left=root->pre_alloc->size-ALIGN_SIZE(sizeof(USED_MEM));
root->free->next=0;
root->block_num= 1;
}
else
root->block_num= 0;
DBUG_VOID_RETURN;
}