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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */
/* Write a record to heap-databas */
#include "heapdef.h"
#ifdef __WIN__
#include <fcntl.h>
#endif
#define LOWFIND 1
#define LOWUSED 2
#define HIGHFIND 4
#define HIGHUSED 8
static byte *next_free_record_pos(HP_SHARE *info);
static HASH_INFO *_hp_find_free_hash(HP_SHARE *info, HP_BLOCK *block,
ulong records);
int heap_write(HP_INFO *info, const byte *record)
{
uint key;
byte *pos;
HP_SHARE *share=info->s;
DBUG_ENTER("heap_write");
#ifndef DBUG_OFF
if (info->mode && O_RDONLY)
{
DBUG_RETURN(my_errno=EACCES);
}
#endif
if (!(pos=next_free_record_pos(share)))
DBUG_RETURN(my_errno);
share->changed=1;
for (key=0 ; key < share->keys ; key++)
{
if (_hp_write_key(share,share->keydef+key,record,pos))
goto err;
}
memcpy(pos,record,(size_t) share->reclength);
pos[share->reclength]=1; /* Mark record as not deleted */
if (++share->records == share->blength)
share->blength+= share->blength;
info->current_ptr=pos;
info->current_hash_ptr=0;
info->update|=HA_STATE_AKTIV;
DBUG_RETURN(0);
err:
info->errkey= key;
do
{
if (_hp_delete_key(info,share->keydef+key,record,pos,0))
break;
} while (key-- > 0);
share->deleted++;
*((byte**) pos)=share->del_link;
share->del_link=pos;
pos[share->reclength]=0; /* Record deleted */
DBUG_RETURN(my_errno);
} /* heap_write */
/* Find where to place new record */
static byte *next_free_record_pos(HP_SHARE *info)
{
int block_pos;
byte *pos;
ulong length;
DBUG_ENTER("next_free_record_pos");
if (info->del_link)
{
pos=info->del_link;
info->del_link= *((byte**) pos);
info->deleted--;
DBUG_PRINT("exit",("Used old position: %lx",pos));
DBUG_RETURN(pos);
}
if (!(block_pos=(info->records % info->block.records_in_block)))
{
if (info->records > info->max_records && info->max_records)
{
my_errno=HA_ERR_RECORD_FILE_FULL;
DBUG_RETURN(NULL);
}
if (_hp_get_new_block(&info->block,&length))
DBUG_RETURN(NULL);
info->data_length+=length;
}
DBUG_PRINT("exit",("Used new position: %lx",
(byte*) info->block.level_info[0].last_blocks+block_pos*
info->block.recbuffer));
DBUG_RETURN((byte*) info->block.level_info[0].last_blocks+
block_pos*info->block.recbuffer);
}
/* Write a hash-key to the hash-index */
int _hp_write_key(register HP_SHARE *info, HP_KEYDEF *keyinfo,
const byte *record, byte *recpos)
{
int flag;
ulong halfbuff,hashnr,first_index;
byte *ptr_to_rec,*ptr_to_rec2;
HASH_INFO *empty,*gpos,*gpos2,*pos;
DBUG_ENTER("hp_write_key");
LINT_INIT(gpos); LINT_INIT(gpos2);
LINT_INIT(ptr_to_rec); LINT_INIT(ptr_to_rec2);
flag=0;
if (!(empty= _hp_find_free_hash(info,&keyinfo->block,info->records)))
DBUG_RETURN(-1); /* No more memory */
halfbuff= (long) info->blength >> 1;
pos= hp_find_hash(&keyinfo->block,(first_index=info->records-halfbuff));
if (pos != empty) /* If some records */
{
do
{
hashnr=_hp_rec_hashnr(keyinfo,pos->ptr_to_rec);
if (flag == 0) /* First loop; Check if ok */
if (_hp_mask(hashnr,info->blength,info->records) != first_index)
break;
if (!(hashnr & halfbuff))
{ /* Key will not move */
if (!(flag & LOWFIND))
{
if (flag & HIGHFIND)
{
flag=LOWFIND | HIGHFIND;
/* key shall be moved to the current empty position */
gpos=empty;
ptr_to_rec=pos->ptr_to_rec;
empty=pos; /* This place is now free */
}
else
{
flag=LOWFIND | LOWUSED; /* key isn't changed */
gpos=pos;
ptr_to_rec=pos->ptr_to_rec;
}
}
else
{
if (!(flag & LOWUSED))
{
/* Change link of previous LOW-key */
gpos->ptr_to_rec=ptr_to_rec;
gpos->next_key=pos;
flag= (flag & HIGHFIND) | (LOWFIND | LOWUSED);
}
gpos=pos;
ptr_to_rec=pos->ptr_to_rec;
}
}
else
{ /* key will be moved */
if (!(flag & HIGHFIND))
{
flag= (flag & LOWFIND) | HIGHFIND;
/* key shall be moved to the last (empty) position */
gpos2 = empty; empty=pos;
ptr_to_rec2=pos->ptr_to_rec;
}
else
{
if (!(flag & HIGHUSED))
{
/* Change link of previous hash-key and save */
gpos2->ptr_to_rec=ptr_to_rec2;
gpos2->next_key=pos;
flag= (flag & LOWFIND) | (HIGHFIND | HIGHUSED);
}
gpos2=pos;
ptr_to_rec2=pos->ptr_to_rec;
}
}
}
while ((pos=pos->next_key));
if ((flag & (LOWFIND | LOWUSED)) == LOWFIND)
{
gpos->ptr_to_rec=ptr_to_rec;
gpos->next_key=0;
}
if ((flag & (HIGHFIND | HIGHUSED)) == HIGHFIND)
{
gpos2->ptr_to_rec=ptr_to_rec2;
gpos2->next_key=0;
}
}
/* Check if we are at the empty position */
pos=hp_find_hash(&keyinfo->block,_hp_mask(_hp_rec_hashnr(keyinfo,record),
info->blength,info->records+1));
if (pos == empty)
{
pos->ptr_to_rec=recpos;
pos->next_key=0;
}
else
{
/* Check if more records in same hash-nr family */
empty[0]=pos[0];
gpos=hp_find_hash(&keyinfo->block,
_hp_mask(_hp_rec_hashnr(keyinfo,pos->ptr_to_rec),
info->blength,info->records+1));
if (pos == gpos)
{
pos->ptr_to_rec=recpos;
pos->next_key=empty;
}
else
{
pos->ptr_to_rec=recpos;
pos->next_key=0;
_hp_movelink(pos,gpos,empty);
}
/* Check if dupplicated keys */
if ((keyinfo->flag & HA_NOSAME) && pos == gpos)
{
pos=empty;
do
{
if (! _hp_rec_key_cmp(keyinfo,record,pos->ptr_to_rec))
{
DBUG_RETURN(my_errno=HA_ERR_FOUND_DUPP_KEY);
}
} while ((pos=pos->next_key));
}
}
DBUG_RETURN(0);
}
/* Returns ptr to block, and allocates block if neaded */
static HASH_INFO *_hp_find_free_hash(HP_SHARE *info,
HP_BLOCK *block, ulong records)
{
uint block_pos;
ulong length;
if (records < block->last_allocated)
return hp_find_hash(block,records);
if (!(block_pos=(records % block->records_in_block)))
{
if (_hp_get_new_block(block,&length))
return(NULL);
info->index_length+=length;
}
block->last_allocated=records+1;
return((HASH_INFO*) ((byte*) block->level_info[0].last_blocks+
block_pos*block->recbuffer));
}
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