summaryrefslogtreecommitdiff
path: root/storage/heap/hp_delete.c
blob: b1df6d78a61909bd6ade04c9ca506fa40dc6f8c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/* Copyright (C) 2000-2002, 2004-2007 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; 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 Street, Fifth Floor, Boston, MA  02110-1301, USA */

/* remove current record in heap-database */

#include "heapdef.h"

int heap_delete(HP_INFO *info, const uchar *record)
{
  uchar *pos;
  HP_SHARE *share=info->s;
  HP_KEYDEF *keydef, *end, *p_lastinx;
  DBUG_ENTER("heap_delete");
  DBUG_PRINT("enter",("info: 0x%lx  record: 0x%lx", (long) info, (long) 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;
  *((uchar**) 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 uchar *record, uchar *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.key_length,
                   &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 uchar *record, uchar *recpos, int flag)
{
  ulong blength, pos2, pos_hashnr, lastpos_hashnr, key_pos;
  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 */
  key_pos= hp_mask(hp_rec_hashnr(keyinfo, record), blength, share->records + 1);
  pos= hp_find_hash(&keyinfo->block, key_pos);

  gpos = pos3 = 0;

  while (pos->ptr_to_rec != recpos)
  {
    if (flag && !hp_rec_key_cmp(keyinfo, record, pos->ptr_to_rec, 0))
      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: 0x%lx",
		       (long) 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 */
    /* 
      One of elements from the bucket we're scanning is moved to the
      beginning of the list. Reset search since this element may not have
      been processed yet. 
    */
    if (flag && pos2 == key_pos)
    {
      info->current_ptr= 0;
      info->current_hash_ptr= 0;
    }
  }
  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);
}