hp_delete.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:6k
- /* 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 */
- /* remove current record in heap-database */
- #include "heapdef.h"
- int heap_delete(HP_INFO *info, const byte *record)
- {
- byte *pos;
- HP_SHARE *share=info->s;
- HP_KEYDEF *keydef, *end, *p_lastinx;
- DBUG_ENTER("heap_delete");
- DBUG_PRINT("enter",("info: %lx record: %lx",info,record));
- test_active(info);
- if (info->opt_flag & READ_CHECK_USED && hp_rectest(info,record))
- DBUG_RETURN(my_errno); /* Record changed */
- share->changed=1;
- if ( --(share->records) < share->blength >> 1) share->blength>>=1;
- pos=info->current_ptr;
- p_lastinx = share->keydef + info->lastinx;
- for (keydef = share->keydef, end = keydef + share->keys; keydef < end;
- keydef++)
- {
- if ((*keydef->delete_key)(info, keydef, record, pos, keydef == p_lastinx))
- goto err;
- }
- info->update=HA_STATE_DELETED;
- *((byte**) pos)=share->del_link;
- share->del_link=pos;
- pos[share->reclength]=0; /* Record deleted */
- share->deleted++;
- info->current_hash_ptr=0;
- #if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
- DBUG_EXECUTE("check_heap",heap_check_heap(info, 0););
- #endif
- DBUG_RETURN(0);
- err:
- if (++(share->records) == share->blength)
- share->blength+= share->blength;
- DBUG_RETURN(my_errno);
- }
- /*
- Remove one key from rb-tree
- */
- int hp_rb_delete_key(HP_INFO *info, register HP_KEYDEF *keyinfo,
- const byte *record, byte *recpos, int flag)
- {
- heap_rb_param custom_arg;
- uint old_allocated;
- int res;
- if (flag)
- info->last_pos= NULL; /* For heap_rnext/heap_rprev */
- custom_arg.keyseg= keyinfo->seg;
- custom_arg.key_length= hp_rb_make_key(keyinfo, info->recbuf, record, recpos);
- custom_arg.search_flag= SEARCH_SAME;
- old_allocated= keyinfo->rb_tree.allocated;
- res= tree_delete(&keyinfo->rb_tree, info->recbuf, &custom_arg);
- info->s->index_length-= (old_allocated - keyinfo->rb_tree.allocated);
- return res;
- }
- /*
- Remove one key from hash-table
- SYNPOSIS
- hp_delete_key()
- info Hash handler
- keyinfo key definition of key that we want to delete
- record row data to be deleted
- recpos Pointer to heap record in memory
- flag Is set if we want's to correct info->current_ptr
- RETURN
- 0 Ok
- other Error code
- */
- int hp_delete_key(HP_INFO *info, register HP_KEYDEF *keyinfo,
- const byte *record, byte *recpos, int flag)
- {
- ulong blength,pos2,pos_hashnr,lastpos_hashnr;
- HASH_INFO *lastpos,*gpos,*pos,*pos3,*empty,*last_ptr;
- HP_SHARE *share=info->s;
- DBUG_ENTER("hp_delete_key");
- blength=share->blength;
- if (share->records+1 == blength)
- blength+= blength;
- lastpos=hp_find_hash(&keyinfo->block,share->records);
- last_ptr=0;
- /* Search after record with key */
- pos= hp_find_hash(&keyinfo->block,
- hp_mask(hp_rec_hashnr(keyinfo, record), blength,
- share->records + 1));
- gpos = pos3 = 0;
- while (pos->ptr_to_rec != recpos)
- {
- if (flag && !hp_rec_key_cmp(keyinfo, record, pos->ptr_to_rec))
- last_ptr=pos; /* Previous same key */
- gpos=pos;
- if (!(pos=pos->next_key))
- {
- DBUG_RETURN(my_errno=HA_ERR_CRASHED); /* This shouldn't happend */
- }
- }
- /* Remove link to record */
- if (flag)
- {
- /* Save for heap_rnext/heap_rprev */
- info->current_hash_ptr=last_ptr;
- info->current_ptr = last_ptr ? last_ptr->ptr_to_rec : 0;
- DBUG_PRINT("info",("Corrected current_ptr to point at: %lx",
- info->current_ptr));
- }
- empty=pos;
- if (gpos)
- gpos->next_key=pos->next_key; /* unlink current ptr */
- else if (pos->next_key)
- {
- empty=pos->next_key;
- pos->ptr_to_rec=empty->ptr_to_rec;
- pos->next_key=empty->next_key;
- }
- else
- keyinfo->hash_buckets--;
- if (empty == lastpos) /* deleted last hash key */
- DBUG_RETURN (0);
- /* Move the last key (lastpos) */
- lastpos_hashnr = hp_rec_hashnr(keyinfo, lastpos->ptr_to_rec);
- /* pos is where lastpos should be */
- pos=hp_find_hash(&keyinfo->block, hp_mask(lastpos_hashnr, share->blength,
- share->records));
- if (pos == empty) /* Move to empty position. */
- {
- empty[0]=lastpos[0];
- DBUG_RETURN(0);
- }
- pos_hashnr = hp_rec_hashnr(keyinfo, pos->ptr_to_rec);
- /* pos3 is where the pos should be */
- pos3= hp_find_hash(&keyinfo->block,
- hp_mask(pos_hashnr, share->blength, share->records));
- if (pos != pos3)
- { /* pos is on wrong posit */
- empty[0]=pos[0]; /* Save it here */
- pos[0]=lastpos[0]; /* This shold be here */
- hp_movelink(pos, pos3, empty); /* Fix link to pos */
- DBUG_RETURN(0);
- }
- pos2= hp_mask(lastpos_hashnr, blength, share->records + 1);
- if (pos2 == hp_mask(pos_hashnr, blength, share->records + 1))
- { /* Identical key-positions */
- if (pos2 != share->records)
- {
- empty[0]=lastpos[0];
- hp_movelink(lastpos, pos, empty);
- DBUG_RETURN(0);
- }
- pos3= pos; /* Link pos->next after lastpos */
- }
- else
- {
- pos3= 0; /* Different positions merge */
- keyinfo->hash_buckets--;
- }
- empty[0]=lastpos[0];
- hp_movelink(pos3, empty, pos->next_key);
- pos->next_key=empty;
- DBUG_RETURN(0);
- }