delete.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:20k
- /* 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 */
- /* Tar bort ett record fr}n en isam-databas */
- #include "isamdef.h"
- #ifdef __WIN__
- #include <errno.h>
- #endif
- #include <assert.h>
- static int d_search(N_INFO *info,N_KEYDEF *keyinfo,uchar *key,ulong page,
- uchar *anc_buff);
- static int del(N_INFO *info,N_KEYDEF *keyinfo,uchar *key,uchar *anc_buff,
- ulong leaf_page,uchar *leaf_buff,uchar *keypos,
- ulong next_block,uchar *ret_key);
- static int underflow(N_INFO *info,N_KEYDEF *keyinfo,uchar *anc_buff,
- ulong leaf_page, uchar *leaf_buff,uchar *keypos);
- static uint remove_key(N_KEYDEF *keyinfo,uint nod_flag,uchar *keypos,
- uchar *lastkey,uchar *page_end);
- int nisam_delete(N_INFO *info,const byte *record)
- {
- uint i;
- uchar *old_key;
- int save_errno;
- uint32 lastpos;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("nisam_delete");
- /* Test if record is in datafile */
- if (!(info->update & HA_STATE_AKTIV))
- {
- my_errno=HA_ERR_KEY_NOT_FOUND; /* No database read */
- DBUG_RETURN(-1);
- }
- if (share->base.options & HA_OPTION_READ_ONLY_DATA)
- {
- my_errno=EACCES;
- DBUG_RETURN(-1);
- }
- #ifndef NO_LOCKING
- if (_nisam_readinfo(info,F_WRLCK,1)) DBUG_RETURN(-1);
- #endif
- if ((*share->compare_record)(info,record))
- goto err; /* Fel vid kontroll-l{sning */
- /* Remove all keys from the .ISAM file */
- old_key=info->lastkey+share->base.max_key_length;
- for (i=0 ; i < share->state.keys ; i++ )
- {
- VOID(_nisam_make_key(info,i,old_key,record,info->lastpos));
- if (_nisam_ck_delete(info,i,old_key)) goto err;
- }
- if ((*share->delete_record)(info))
- goto err; /* Remove record from database */
- info->update= HA_STATE_CHANGED | HA_STATE_ROW_CHANGED | HA_STATE_DELETED;
- share->state.records--;
- lastpos= (uint32) info->lastpos;
- nisam_log_command(LOG_DELETE,info,(byte*) &lastpos,sizeof(lastpos),0);
- VOID(_nisam_writeinfo(info,1));
- allow_break(); /* Allow SIGHUP & SIGINT */
- DBUG_RETURN(0);
- err:
- save_errno=my_errno;
- lastpos= (uint32) info->lastpos;
- nisam_log_command(LOG_DELETE,info,(byte*) &lastpos, sizeof(lastpos),0);
- VOID(_nisam_writeinfo(info,1));
- info->update|=HA_STATE_WRITTEN; /* Buffer changed */
- allow_break(); /* Allow SIGHUP & SIGINT */
- my_errno=save_errno;
- if (save_errno == HA_ERR_KEY_NOT_FOUND)
- my_errno=HA_ERR_CRASHED;
- DBUG_RETURN(-1);
- } /* nisam_delete */
- /* Tar bort en nyckel till isam-nyckelfilen */
- int _nisam_ck_delete(register N_INFO *info, uint keynr, uchar *key)
- {
- int error;
- uint nod_flag;
- ulong old_root;
- uchar *root_buff;
- N_KEYDEF *keyinfo;
- DBUG_ENTER("_nisam_ck_delete");
- if ((old_root=info->s->state.key_root[keynr]) == NI_POS_ERROR)
- {
- my_errno=HA_ERR_CRASHED;
- DBUG_RETURN(-1);
- }
- keyinfo=info->s->keyinfo+keynr;
- if (!(root_buff= (uchar*) my_alloca((uint) keyinfo->base.block_length+
- N_MAX_KEY_BUFF*2)))
- DBUG_RETURN(-1);
- if (!_nisam_fetch_keypage(info,keyinfo,old_root,root_buff,0))
- {
- error= -1;
- goto err;
- }
- if ((error=d_search(info,keyinfo,key,old_root,root_buff)) >0)
- {
- if (error == 2)
- {
- DBUG_PRINT("test",("Enlarging of root when deleting"));
- error=_nisam_enlarge_root(info,keynr,key);
- }
- else
- {
- error=0;
- if (getint(root_buff) <= (nod_flag=test_if_nod(root_buff))+3)
- {
- if (nod_flag)
- info->s->state.key_root[keynr]=_nisam_kpos(nod_flag,
- root_buff+2+nod_flag);
- else
- info->s->state.key_root[keynr]= NI_POS_ERROR;
- if (_nisam_dispose(info,keyinfo,old_root))
- error= -1;
- }
- }
- }
- err:
- my_afree((gptr) root_buff);
- DBUG_RETURN(error);
- } /* _nisam_ck_delete */
- /* Tar bort en nyckel under root */
- /* Returnerar 1 om nuvarande buffert minskade */
- /* Returnerar 2 om nuvarande buffert |kar */
- static int d_search(register N_INFO *info, register N_KEYDEF *keyinfo, uchar *key, ulong page, uchar *anc_buff)
- {
- int flag,ret_value,save_flag;
- uint length,nod_flag;
- uchar *leaf_buff,*keypos,*next_keypos;
- ulong leaf_page,next_block;
- uchar lastkey[N_MAX_KEY_BUFF];
- DBUG_ENTER("d_search");
- DBUG_DUMP("page",(byte*) anc_buff,getint(anc_buff));
- flag=(*keyinfo->bin_search)(info,keyinfo,anc_buff,key,0,SEARCH_SAME,&keypos,
- lastkey);
- nod_flag=test_if_nod(anc_buff);
- leaf_buff=0;
- LINT_INIT(leaf_page);
- if (nod_flag)
- {
- leaf_page=_nisam_kpos(nod_flag,keypos);
- if (!(leaf_buff= (uchar*) my_alloca((uint) keyinfo->base.block_length+
- N_MAX_KEY_BUFF*2)))
- {
- my_errno=ENOMEM;
- DBUG_RETURN(-1);
- }
- if (!_nisam_fetch_keypage(info,keyinfo,leaf_page,leaf_buff,0))
- goto err;
- }
- if (flag != 0)
- {
- if (!nod_flag)
- {
- my_errno=HA_ERR_CRASHED; /* This should newer happend */
- goto err;
- }
- save_flag=0;
- ret_value=d_search(info,keyinfo,key,leaf_page,leaf_buff);
- }
- else
- { /* Found key */
- next_keypos=keypos; /* Find where next block is */
- VOID((*keyinfo->get_key)(keyinfo,nod_flag,&next_keypos,lastkey));
- next_block=_nisam_kpos(nod_flag,next_keypos);
- length=getint(anc_buff);
- length-= remove_key(keyinfo,nod_flag,keypos,lastkey,anc_buff+length);
- putint(anc_buff,length,nod_flag);
- if (!nod_flag)
- { /* On leaf page */
- if (_nisam_write_keypage(info,keyinfo,page,anc_buff))
- DBUG_RETURN(-1);
- DBUG_RETURN(length <= (uint) keyinfo->base.block_length/2);
- }
- save_flag=1;
- ret_value=del(info,keyinfo,key,anc_buff,leaf_page,leaf_buff,keypos,
- next_block,lastkey);
- }
- if (ret_value >0)
- {
- save_flag=1;
- if (ret_value == 1)
- ret_value= underflow(info,keyinfo,anc_buff,leaf_page,leaf_buff,keypos);
- else
- { /* This happens only with packed keys */
- DBUG_PRINT("test",("Enlarging of key when deleting"));
- VOID(_nisam_get_last_key(info,keyinfo,anc_buff,lastkey,keypos));
- ret_value=_nisam_insert(info,keyinfo,key,anc_buff,keypos,lastkey,
- (uchar*) 0,(uchar*) 0,0L);
- }
- }
- if (ret_value == 0 && getint(anc_buff) > keyinfo->base.block_length)
- {
- save_flag=1;
- ret_value=_nisam_splitt_page(info,keyinfo,key,anc_buff,lastkey) | 2;
- }
- if (save_flag)
- ret_value|=_nisam_write_keypage(info,keyinfo,page,anc_buff);
- else
- {
- DBUG_DUMP("page",(byte*) anc_buff,getint(anc_buff));
- }
- my_afree((byte*) leaf_buff);
- DBUG_RETURN(ret_value);
- err:
- my_afree((byte*) leaf_buff);
- DBUG_PRINT("exit",("Error: %d",my_errno));
- DBUG_RETURN (-1);
- } /* d_search */
- /* Remove a key that has a page-reference */
- static int del(register N_INFO *info, register N_KEYDEF *keyinfo, uchar *key,
- uchar *anc_buff, ulong leaf_page, uchar *leaf_buff,
- uchar *keypos, /* Pos to where deleted key was */
- ulong next_block,
- uchar *ret_key) /* key before keypos in anc_buff */
- {
- int ret_value,length;
- uint a_length,nod_flag;
- ulong next_page;
- uchar keybuff[N_MAX_KEY_BUFF],*endpos,*next_buff,*key_start;
- ISAM_SHARE *share=info->s;
- S_PARAM s_temp;
- DBUG_ENTER("del");
- DBUG_PRINT("enter",("leaf_page: %ld keypos: %lx",leaf_page,keypos));
- DBUG_DUMP("leaf_buff",(byte*) leaf_buff,getint(leaf_buff));
- endpos=leaf_buff+getint(leaf_buff);
- key_start=_nisam_get_last_key(info,keyinfo,leaf_buff,keybuff,endpos);
- if ((nod_flag=test_if_nod(leaf_buff)))
- {
- next_page= _nisam_kpos(nod_flag,endpos);
- if (!(next_buff= (uchar*) my_alloca((uint) keyinfo->base.block_length+
- N_MAX_KEY_BUFF)))
- DBUG_RETURN(-1);
- if (!_nisam_fetch_keypage(info,keyinfo,next_page,next_buff,0))
- ret_value= -1;
- else
- {
- DBUG_DUMP("next_page",(byte*) next_buff,getint(next_buff));
- if ((ret_value=del(info,keyinfo,key,anc_buff,next_page,next_buff,
- keypos,next_block,ret_key)) >0)
- {
- endpos=leaf_buff+getint(leaf_buff);
- if (ret_value == 1)
- {
- ret_value=underflow(info,keyinfo,leaf_buff,next_page,
- next_buff,endpos);
- if (ret_value == 0 && getint(leaf_buff) > keyinfo->base.block_length)
- {
- ret_value=_nisam_splitt_page(info,keyinfo,key,leaf_buff,ret_key) | 2;
- }
- }
- else
- {
- DBUG_PRINT("test",("Inserting of key when deleting"));
- VOID(_nisam_get_last_key(info,keyinfo,leaf_buff,keybuff,endpos));
- ret_value=_nisam_insert(info,keyinfo,key,leaf_buff,endpos,keybuff,
- (uchar*) 0,(uchar*) 0,0L);
- }
- }
- if (_nisam_write_keypage(info,keyinfo,leaf_page,leaf_buff))
- goto err;
- }
- my_afree((byte*) next_buff);
- DBUG_RETURN(ret_value);
- }
- /* Remove last key from leaf page */
- putint(leaf_buff,key_start-leaf_buff,nod_flag);
- if (_nisam_write_keypage(info,keyinfo,leaf_page,leaf_buff))
- goto err;
- /* Place last key in ancestor page on deleted key position */
- a_length=getint(anc_buff);
- endpos=anc_buff+a_length;
- VOID(_nisam_get_last_key(info,keyinfo,anc_buff,ret_key,keypos));
- length=_nisam_get_pack_key_length(keyinfo,share->base.key_reflength,
- keypos == endpos ? (uchar*) 0 : keypos,
- ret_key,keybuff,&s_temp);
- if (length > 0)
- bmove_upp((byte*) endpos+length,(byte*) endpos,(uint) (endpos-keypos));
- else
- bmove(keypos,keypos-length, (int) (endpos-keypos)+length);
- _nisam_store_key(keyinfo,keypos,&s_temp);
- /* Save pointer to next leaf */
- VOID((*keyinfo->get_key)(keyinfo,share->base.key_reflength,&keypos,ret_key));
- _nisam_kpointer(info,keypos - share->base.key_reflength,next_block);
- putint(anc_buff,a_length+length,share->base.key_reflength);
- DBUG_RETURN( getint(leaf_buff) <= (uint) keyinfo->base.block_length/2 );
- err:
- DBUG_RETURN(-1);
- } /* del */
- /* Balances adjacent pages if underflow occours */
- static int underflow(register N_INFO *info, register N_KEYDEF *keyinfo,
- uchar *anc_buff,
- ulong leaf_page, /* Ancestor page and underflow page */
- uchar *leaf_buff,
- uchar *keypos) /* Position to pos after key */
- {
- int t_length;
- uint length,anc_length,buff_length,leaf_length,p_length,s_length,nod_flag;
- ulong next_page;
- uchar anc_key[N_MAX_KEY_BUFF],leaf_key[N_MAX_KEY_BUFF],
- *buff,*endpos,*next_keypos,*half_pos,*temp_pos;
- S_PARAM s_temp;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("underflow");
- DBUG_PRINT("enter",("leaf_page: %ld keypos: %lx",leaf_page,keypos));
- DBUG_DUMP("anc_buff",(byte*) anc_buff,getint(anc_buff));
- DBUG_DUMP("leaf_buff",(byte*) leaf_buff,getint(leaf_buff));
- buff=info->buff;
- next_keypos=keypos;
- nod_flag=test_if_nod(leaf_buff);
- p_length=2+nod_flag;
- anc_length=getint(anc_buff);
- leaf_length=getint(leaf_buff);
- info->page_changed=1;
- if ((keypos < anc_buff+anc_length && (share->rnd++ & 1)) ||
- keypos == anc_buff+2+share->base.key_reflength)
- { /* Use page right of anc-page */
- DBUG_PRINT("test",("use right page"));
- VOID((*keyinfo->get_key)(keyinfo,share->base.key_reflength,&next_keypos,
- buff));
- next_page= _nisam_kpos(share->base.key_reflength,next_keypos);
- if (!_nisam_fetch_keypage(info,keyinfo,next_page,buff,0))
- goto err;
- buff_length=getint(buff);
- DBUG_DUMP("next",(byte*) buff,buff_length);
- /* find keys to make a big key-page */
- bmove((byte*) next_keypos-share->base.key_reflength,(byte*) buff+2,
- share->base.key_reflength);
- VOID(_nisam_get_last_key(info,keyinfo,anc_buff,anc_key,next_keypos));
- VOID(_nisam_get_last_key(info,keyinfo,leaf_buff,leaf_key,
- leaf_buff+leaf_length));
- /* merge pages and put parting key from anc_buff between */
- t_length=(int) _nisam_get_pack_key_length(keyinfo,nod_flag,buff+p_length,
- (leaf_length == nod_flag+2 ?
- (uchar*) 0 : leaf_key),
- anc_key,&s_temp);
- length=buff_length-p_length;
- endpos=buff+length+leaf_length+t_length;
- bmove_upp((byte*) endpos, (byte*) buff+buff_length,length);
- memcpy((byte*) buff, (byte*) leaf_buff,(size_t) leaf_length);
- _nisam_store_key(keyinfo,buff+leaf_length,&s_temp);
- buff_length=(uint) (endpos-buff);
- putint(buff,buff_length,nod_flag);
- /* remove key from anc_buff */
- s_length=remove_key(keyinfo,share->base.key_reflength,keypos,anc_key,
- anc_buff+anc_length);
- putint(anc_buff,(anc_length-=s_length),share->base.key_reflength);
- if (buff_length <= keyinfo->base.block_length)
- { /* Keys in one page */
- memcpy((byte*) leaf_buff,(byte*) buff,(size_t) buff_length);
- if (_nisam_dispose(info,keyinfo,next_page))
- goto err;
- }
- else
- { /* Page is full */
- VOID(_nisam_get_last_key(info,keyinfo,anc_buff,anc_key,keypos));
- half_pos=_nisam_find_half_pos(info,keyinfo,buff,leaf_key);
- length=(uint) (half_pos-buff);
- memcpy((byte*) leaf_buff,(byte*) buff,(size_t) length);
- putint(leaf_buff,length,nod_flag);
- endpos=anc_buff+anc_length;
- /* Correct new keypointer to leaf_page */
- length=(*keyinfo->get_key)(keyinfo,nod_flag,&half_pos,leaf_key);
- _nisam_kpointer(info,leaf_key+length,next_page);
- /* Save key in anc_buff */
- t_length=(int) _nisam_get_pack_key_length(keyinfo,
- share->base.key_reflength,
- keypos == endpos ?
- (uchar*) 0 : keypos,
- anc_key,leaf_key,&s_temp);
- if (t_length >= 0)
- bmove_upp((byte*) endpos+t_length,(byte*) endpos,
- (uint) (endpos-keypos));
- else
- bmove(keypos,keypos-t_length,(uint) (endpos-keypos)+t_length);
- _nisam_store_key(keyinfo,keypos,&s_temp);
- putint(anc_buff,(anc_length+=t_length),share->base.key_reflength);
- /* Store new page */
- if (nod_flag)
- bmove((byte*) buff+2,(byte*) half_pos-nod_flag,(size_t) nod_flag);
- VOID((*keyinfo->get_key)(keyinfo,nod_flag,&half_pos,leaf_key));
- t_length=(int) _nisam_get_pack_key_length(keyinfo,nod_flag,(uchar*) 0,
- (uchar*) 0, leaf_key,&s_temp);
- s_temp.n_length= *half_pos; /* For _nisam_store_key */
- length=(uint) ((buff+getint(buff))-half_pos);
- bmove((byte*) buff+p_length+t_length,(byte*) half_pos,(size_t) length);
- _nisam_store_key(keyinfo,buff+p_length,&s_temp);
- putint(buff,length+t_length+p_length,nod_flag);
- if (_nisam_write_keypage(info,keyinfo,next_page,buff))
- goto err;
- }
- if (_nisam_write_keypage(info,keyinfo,leaf_page,leaf_buff))
- goto err;
- DBUG_RETURN(anc_length <= (uint) keyinfo->base.block_length/2);
- }
- DBUG_PRINT("test",("use left page"));
- keypos=_nisam_get_last_key(info,keyinfo,anc_buff,anc_key,keypos);
- next_page= _nisam_kpos(share->base.key_reflength,keypos);
- if (!_nisam_fetch_keypage(info,keyinfo,next_page,buff,0))
- goto err;
- buff_length=getint(buff);
- endpos=buff+buff_length;
- DBUG_DUMP("prev",(byte*) buff,buff_length);
- /* find keys to make a big key-page */
- bmove((byte*) next_keypos - share->base.key_reflength,(byte*) leaf_buff+2,
- share->base.key_reflength);
- next_keypos=keypos;
- VOID((*keyinfo->get_key)(keyinfo,share->base.key_reflength,&next_keypos,
- anc_key));
- VOID(_nisam_get_last_key(info,keyinfo,buff,leaf_key,endpos));
- /* merge pages and put parting key from anc_buff between */
- t_length=(int) _nisam_get_pack_key_length(keyinfo,nod_flag,
- leaf_buff+p_length,
- (leaf_length == nod_flag+2 ?
- (uchar*) 0 : leaf_key),
- anc_key,&s_temp);
- if (t_length >= 0)
- bmove((byte*) endpos+t_length,(byte*) leaf_buff+p_length,
- (size_t) (leaf_length-p_length));
- else /* We gained space */
- bmove((byte*) endpos,(byte*) leaf_buff+((int) p_length-t_length),
- (size_t) (leaf_length-p_length+t_length));
- _nisam_store_key(keyinfo,endpos,&s_temp);
- buff_length=buff_length+leaf_length-p_length+t_length;
- putint(buff,buff_length,nod_flag);
- /* remove key from anc_buff */
- s_length=remove_key(keyinfo,share->base.key_reflength,keypos,anc_key,
- anc_buff+anc_length);
- putint(anc_buff,(anc_length-=s_length),share->base.key_reflength);
- if (buff_length <= keyinfo->base.block_length)
- { /* Keys in one page */
- if (_nisam_dispose(info,keyinfo,leaf_page))
- goto err;
- }
- else
- { /* Page is full */
- VOID(_nisam_get_last_key(info,keyinfo,anc_buff,anc_key,keypos));
- endpos=half_pos=_nisam_find_half_pos(info,keyinfo,buff,leaf_key);
- /* Correct new keypointer to leaf_page */
- length=(*keyinfo->get_key)(keyinfo,nod_flag,&half_pos,leaf_key);
- _nisam_kpointer(info,leaf_key+length,leaf_page);
- /* Save key in anc_buff */
- DBUG_DUMP("anc_buff",(byte*) anc_buff,anc_length);
- DBUG_DUMP("key",(byte*) leaf_key,16);
- temp_pos=anc_buff+anc_length;
- t_length=(int) _nisam_get_pack_key_length(keyinfo,
- share->base.key_reflength,
- keypos == temp_pos ? (uchar*) 0
- : keypos,
- anc_key,leaf_key,&s_temp);
- if (t_length > 0)
- bmove_upp((byte*) temp_pos+t_length,(byte*) temp_pos,
- (uint) (temp_pos-keypos));
- else
- bmove(keypos,keypos-t_length,(uint) (temp_pos-keypos)+t_length);
- _nisam_store_key(keyinfo,keypos,&s_temp);
- putint(anc_buff,(anc_length+=t_length),share->base.key_reflength);
- /* Store new page */
- if (nod_flag)
- bmove((byte*) leaf_buff+2,(byte*) half_pos-nod_flag,(size_t) nod_flag);
- VOID((*keyinfo->get_key)(keyinfo,nod_flag,&half_pos,leaf_key));
- t_length=(int) _nisam_get_pack_key_length(keyinfo,nod_flag, (uchar*) 0,
- (uchar*) 0, leaf_key, &s_temp);
- s_temp.n_length= *half_pos; /* For _nisam_store_key */
- length=(uint) ((buff+buff_length)-half_pos);
- bmove((byte*) leaf_buff+p_length+t_length,(byte*) half_pos,
- (size_t) length);
- _nisam_store_key(keyinfo,leaf_buff+p_length,&s_temp);
- putint(leaf_buff,length+t_length+p_length,nod_flag);
- putint(buff,endpos-buff,nod_flag);
- if (_nisam_write_keypage(info,keyinfo,leaf_page,leaf_buff))
- goto err;
- }
- if (_nisam_write_keypage(info,keyinfo,next_page,buff))
- goto err;
- DBUG_RETURN(anc_length <= (uint) keyinfo->base.block_length/2);
- err:
- DBUG_RETURN(-1);
- } /* underflow */
- /* remove a key from packed buffert */
- /* returns how many chars was removed */
- static uint remove_key(N_KEYDEF *keyinfo, uint nod_flag,
- uchar *keypos, /* Where key starts */
- uchar *lastkey, /* key to be removed */
- uchar *page_end) /* End of page */
- {
- int r_length,s_length,first,diff_flag;
- uchar *start;
- DBUG_ENTER("remove_key");
- DBUG_PRINT("enter",("keypos: %lx page_end: %lx",keypos,page_end));
- start=keypos;
- if (!(keyinfo->base.flag & (HA_PACK_KEY | HA_SPACE_PACK_USED)))
- s_length=(int) (keyinfo->base.keylength+nod_flag);
- else
- { /* Let keypos point at next key */
- VOID((*keyinfo->get_key)(keyinfo,nod_flag,&keypos,lastkey));
- s_length=(uint) (keypos-start);
- if (keyinfo->base.flag & HA_PACK_KEY)
- {
- diff_flag= (keyinfo->seg[0].base.flag & HA_SPACE_PACK);
- first= *start;
- if (keypos != page_end && *keypos & 128 && first != 128)
- { /* Referens length */
- if ((r_length= *keypos++ & 127) == 0)
- { /* Same key after */
- if (first & 128)
- start++; /* Skip ref length */
- if (diff_flag)
- start+= *start+1; /* Skip key length */
- else
- start+=keyinfo->seg[0].base.length- (first & 127);
- s_length=(uint)(keypos-start); /* Remove pntrs and next-key-flag */
- }
- else if (! (first & 128))
- { /* Deleted key was not compressed */
- if (diff_flag)
- {
- *start= (uchar) (r_length+ *keypos);
- start+=r_length+1; /* Let ref-part remain */
- s_length=(uint) (keypos-start)+1; /* Skip everything between */
- }
- else
- {
- start+=r_length+1; /* Let ref-part remain */
- s_length=(uint) (keypos-start); /* Skip everything between */
- }
- }
- else if ((first & 127) < r_length)
- { /* mid-part of key is used */
- r_length-=(first & 127);
- start++; /* Ref remains the same */
- if (diff_flag)
- *start++= (uchar) (*keypos++ + r_length);
- start+= r_length;
- s_length=(uint) (keypos-start); /* Skip everything between */
- }
- }
- }
- }
- bmove((byte*) start,(byte*) start+s_length,
- (uint) (page_end-start-s_length));
- DBUG_RETURN((uint) s_length);
- } /* remove_key */