mariadb/storage/heap/heapdef.h
Monty 52c29f3bdc MDEV-35469 Heap tables are calling mallocs to often
Heap tables are allocated blocks to store rows according to
my_default_record_cache (mapped to the server global variable
 read_buffer_size).
This causes performance issues when the record length is big
(> 1000 bytes) and the my_default_record_cache is small.

Changed to instead split the default heap allocation to 1/16 of the
allowed space and not use my_default_record_cache anymore when creating
the heap. The allocation is also aligned to be just under a power of 2.

For some test that I have been running, which was using record length=633,
the speed of the query doubled thanks to this change.

Other things:
- Fixed calculation of max_records passed to hp_create() to take
  into account padding between records.
- Updated calculation of memory needed by heap tables. Before we
  did not take into account internal structures needed to access rows.
- Changed block sized for memory_table from 1 to 16384 to get less
  fragmentation. This also avoids a problem where we need 1K
  to manage index and row storage which was not counted for before.
- Moved heap memory usage to a separate test for 32 bit.
- Allocate all data blocks in heap in powers of 2. Change reported
  memory usage for heap to reflect this.

Reviewed-by: Sergei Golubchik <serg@mariadb.org>
2025-01-05 16:40:11 +02:00

139 lines
4.9 KiB
C

/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
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; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
/* This file is included in all heap-files */
#include <my_global.h>
#include <my_base.h>
C_MODE_START
#include <my_pthread.h>
#include "heap.h" /* Structs & some defines */
#include "my_tree.h"
/*
When allocating keys /rows in the internal block structure, do it
within the following boundaries.
The challenge is to find the balance between allocate as few blocks
as possible and keep memory consumption down.
*/
#define HP_MIN_RECORDS_IN_BLOCK 16
#define HP_MAX_RECORDS_IN_BLOCK 8192
/* Some extern variables */
extern LIST *heap_open_list,*heap_share_list;
#define test_active(info) \
if (!(info->update & HA_STATE_AKTIV))\
{ my_errno=HA_ERR_NO_ACTIVE_RECORD; DBUG_RETURN(-1); }
#define hp_find_hash(A,B) ((HASH_INFO*) hp_find_block((A),(B)))
/* Find pos for record and update it in info->current_ptr */
#define hp_find_record(info,pos) (info)->current_ptr= hp_find_block(&(info)->s->block,pos)
typedef struct st_hp_hash_info
{
struct st_hp_hash_info *next_key;
uchar *ptr_to_rec;
ulong hash_of_key;
} HASH_INFO;
typedef struct {
HA_KEYSEG *keyseg;
uint key_length;
uint search_flag;
} heap_rb_param;
/* Prototypes for intern functions */
extern HP_SHARE *hp_find_named_heap(const char *name);
extern int hp_rectest(HP_INFO *info,const uchar *old);
extern uchar *hp_find_block(HP_BLOCK *info,ulong pos);
extern int hp_get_new_block(HP_SHARE *info, HP_BLOCK *block,
size_t* alloc_length);
extern void hp_free(HP_SHARE *info);
extern uchar *hp_free_level(HP_BLOCK *block,uint level,HP_PTRS *pos,
uchar *last_pos);
extern int hp_write_key(HP_INFO *info, HP_KEYDEF *keyinfo,
const uchar *record, uchar *recpos);
extern int hp_rb_write_key(HP_INFO *info, HP_KEYDEF *keyinfo,
const uchar *record, uchar *recpos);
extern int hp_rb_delete_key(HP_INFO *info,HP_KEYDEF *keyinfo,
const uchar *record,uchar *recpos,int flag);
extern int hp_delete_key(HP_INFO *info,HP_KEYDEF *keyinfo,
const uchar *record,uchar *recpos,int flag);
extern HASH_INFO *_heap_find_hash(HP_BLOCK *block,ulong pos);
extern uchar *hp_search(HP_INFO *info,HP_KEYDEF *keyinfo,const uchar *key,
uint nextflag);
extern uchar *hp_search_next(HP_INFO *info, HP_KEYDEF *keyinfo,
const uchar *key, HASH_INFO *pos);
extern ulong hp_rec_hashnr(HP_KEYDEF *keyinfo,const uchar *rec);
extern void hp_movelink(HASH_INFO *pos,HASH_INFO *next_link,
HASH_INFO *newlink);
extern int hp_rec_key_cmp(HP_KEYDEF *keydef,const uchar *rec1,
const uchar *rec2);
extern int hp_key_cmp(HP_KEYDEF *keydef,const uchar *rec,
const uchar *key);
extern void hp_make_key(HP_KEYDEF *keydef,uchar *key,const uchar *rec);
extern uint hp_rb_make_key(HP_KEYDEF *keydef, uchar *key,
const uchar *rec, uchar *recpos);
extern uint hp_rb_key_length(HP_KEYDEF *keydef, const uchar *key);
extern uint hp_rb_null_key_length(HP_KEYDEF *keydef, const uchar *key);
extern uint hp_rb_var_key_length(HP_KEYDEF *keydef, const uchar *key);
extern my_bool hp_if_null_in_key(HP_KEYDEF *keyinfo, const uchar *record);
extern int hp_close(HP_INFO *info);
extern void hp_clear(HP_SHARE *info);
extern void hp_clear_keys(HP_SHARE *info);
extern uint hp_rb_pack_key(HP_KEYDEF *keydef, uchar *key, const uchar *old,
key_part_map keypart_map);
extern ha_rows hp_rows_in_memory(size_t reclength, size_t index_size,
size_t memory_limit);
extern size_t hp_memory_needed_per_row(size_t reclength);
extern mysql_mutex_t THR_LOCK_heap;
extern PSI_memory_key hp_key_memory_HP_SHARE;
extern PSI_memory_key hp_key_memory_HP_INFO;
extern PSI_memory_key hp_key_memory_HP_PTRS;
extern PSI_memory_key hp_key_memory_HP_KEYDEF;
#ifdef HAVE_PSI_INTERFACE
void init_heap_psi_keys();
#else
#define init_heap_psi_keys() do { } while(0)
#endif /* HAVE_PSI_INTERFACE */
C_MODE_END
/*
Calculate position number for hash value.
SYNOPSIS
hp_mask()
hashnr Hash value
buffmax Value such that
2^(n-1) < maxlength <= 2^n = buffmax
maxlength
RETURN
Array index, in [0..maxlength)
*/
static inline ulong hp_mask(ulong hashnr, ulong buffmax, ulong maxlength)
{
if ((hashnr & (buffmax-1)) < maxlength) return (hashnr & (buffmax-1));
return (hashnr & ((buffmax >> 1) -1));
}