diff options
Diffstat (limited to 'isam/_search.c')
| -rw-r--r-- | isam/_search.c | 889 |
1 files changed, 0 insertions, 889 deletions
diff --git a/isam/_search.c b/isam/_search.c deleted file mode 100644 index fbffd6786e1..00000000000 --- a/isam/_search.c +++ /dev/null @@ -1,889 +0,0 @@ -/* 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 */ - -/* S|ker efter positionen f|r en nyckel samt d{rmedh|rande funktioner */ - -#include "isamdef.h" -#include "m_ctype.h" - -#define CMP(a,b) (a<b ? -1 : a == b ? 0 : 1) - - /* Check index */ - -int _nisam_check_index(N_INFO *info, int inx) -{ - if (inx == -1) /* Use last index */ - inx=info->lastinx; - if (inx >= (int) info->s->state.keys || inx < 0) - { - my_errno=HA_ERR_WRONG_INDEX; - return -1; - } - if (info->lastinx != inx) /* Index changed */ - { - info->lastinx = inx; - info->lastpos = NI_POS_ERROR; - info->update= ((info->update & (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED)) | - HA_STATE_NEXT_FOUND | HA_STATE_PREV_FOUND); - } - if (info->opt_flag & WRITE_CACHE_USED && flush_io_cache(&info->rec_cache)) - return(-1); - return(inx); -} /* ni_check_index */ - - - /* S|ker reda p} positionen f|r ett record p} basen av en nyckel */ - /* Positionen l{ggs i info->lastpos */ - /* Returns -1 if not found and 1 if search at upper levels */ - -int _nisam_search(register N_INFO *info, register N_KEYDEF *keyinfo, uchar *key, uint key_len, uint nextflag, register ulong pos) -{ - int error,flag; - uint nod_flag; - uchar *keypos,*maxpos; - uchar lastkey[N_MAX_KEY_BUFF],*buff; - DBUG_ENTER("_nisam_search"); - DBUG_PRINT("enter",("pos: %ld nextflag: %d lastpos: %ld", - pos,nextflag,info->lastpos)); - - if (pos == NI_POS_ERROR) - { - my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ - info->lastpos= NI_POS_ERROR; - if (!(nextflag & (SEARCH_SMALLER | SEARCH_BIGGER | SEARCH_LAST))) - DBUG_RETURN(-1); /* Not found ; return error */ - DBUG_RETURN(1); /* Search at upper levels */ - } - - if (!(buff=_nisam_fetch_keypage(info,keyinfo,pos,info->buff, - test(!(nextflag & SEARCH_SAVE_BUFF))))) - goto err; - DBUG_DUMP("page",(byte*) buff,getint(buff)); - - flag=(*keyinfo->bin_search)(info,keyinfo,buff,key,key_len,nextflag, - &keypos,lastkey); - nod_flag=test_if_nod(buff); - maxpos=buff+getint(buff)-1; - - if (flag) - { - if ((error=_nisam_search(info,keyinfo,key,key_len,nextflag, - _nisam_kpos(nod_flag,keypos))) <= 0) - DBUG_RETURN(error); - - if (flag >0) - { - if ((nextflag & (SEARCH_SMALLER | SEARCH_LAST)) && - keypos == buff+2+nod_flag) - DBUG_RETURN(1); /* Bigger than key */ - } - else if (nextflag & SEARCH_BIGGER && keypos >= maxpos) - DBUG_RETURN(1); /* Smaller than key */ - } - else - { - if (nextflag & SEARCH_FIND && (!(keyinfo->base.flag & HA_NOSAME) - || key_len) && nod_flag) - { - if ((error=_nisam_search(info,keyinfo,key,key_len,SEARCH_FIND, - _nisam_kpos(nod_flag,keypos))) >= 0 || - my_errno != HA_ERR_KEY_NOT_FOUND) - DBUG_RETURN(error); - info->int_pos= NI_POS_ERROR; /* Buffer not in memory */ - } - } - if (pos != info->int_pos) - { - uchar *old_buff=buff; - if (!(buff=_nisam_fetch_keypage(info,keyinfo,pos,info->buff, - test(!(nextflag & SEARCH_SAVE_BUFF))))) - goto err; - keypos=buff+(keypos-old_buff); - maxpos=buff+(maxpos-old_buff); - } - - if ((nextflag & (SEARCH_SMALLER | SEARCH_LAST)) && flag != 0) - { - keypos=_nisam_get_last_key(info,keyinfo,buff,lastkey,keypos); - if (!(nextflag & SEARCH_SMALLER) && - _nisam_key_cmp(keyinfo->seg, lastkey, key, key_len, SEARCH_FIND)) - { - my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ - goto err; - } - } - - VOID((*keyinfo->get_key)(keyinfo,nod_flag,&keypos,lastkey)); - VOID(_nisam_move_key(keyinfo,info->lastkey,lastkey)); - info->lastpos=_nisam_dpos(info,nod_flag,keypos); - info->int_keypos=info->buff+ (keypos-buff); - info->int_maxpos=info->buff+ (maxpos-buff); - info->page_changed=0; - info->buff_used= (info->buff != buff); - info->last_search_keypage=info->int_pos; - - DBUG_PRINT("exit",("found key at %ld",info->lastpos)); - DBUG_RETURN(0); -err: - DBUG_PRINT("exit",("Error: %d",my_errno)); - info->lastpos= NI_POS_ERROR; - DBUG_RETURN (-1); -} /* _nisam_search */ - - - /* Search after key in page-block */ - /* If packed key puts smaller or identical key in buff */ - /* ret_pos point to where find or bigger key starts */ - /* ARGSUSED */ - -int _nisam_bin_search(N_INFO *info, register N_KEYDEF *keyinfo, uchar *page, - uchar *key, uint key_len, uint comp_flag, uchar **ret_pos, - uchar *buff __attribute__((unused))) -{ - reg4 int start,mid,end; - int flag; - uint totlength,nod_flag; - DBUG_ENTER("_nisam_bin_search"); - - LINT_INIT(flag); - totlength=keyinfo->base.keylength+(nod_flag=test_if_nod(page)); - start=0; mid=1; - end= (int) ((getint(page)-2-nod_flag)/totlength-1); - DBUG_PRINT("test",("getint: %d end: %d",getint(page),end)); - page+=2+nod_flag; - - while (start != end) - { - mid= (start+end)/2; - if ((flag=_nisam_key_cmp(keyinfo->seg,page+(uint) mid*totlength,key,key_len, - comp_flag)) - >= 0) - end=mid; - else - start=mid+1; - } - if (mid != start) - flag=_nisam_key_cmp(keyinfo->seg,page+(uint) start*totlength,key,key_len, - comp_flag); - if (flag < 0) - start++; /* point at next, bigger key */ - *ret_pos=page+(uint) start*totlength; - DBUG_PRINT("exit",("flag: %d keypos: %d",flag,start)); - DBUG_RETURN(flag); -} /* _nisam_bin_search */ - - - /* Used instead of _nisam_bin_search() when key is packed */ - /* Puts smaller or identical key in buff */ - /* Key is searched sequentially */ - -int _nisam_seq_search(N_INFO *info, register N_KEYDEF *keyinfo, uchar *page, uchar *key, uint key_len, uint comp_flag, uchar **ret_pos, uchar *buff) -{ - int flag; - uint nod_flag,length; - uchar t_buff[N_MAX_KEY_BUFF],*end; - DBUG_ENTER("_nisam_seq_search"); - - LINT_INIT(flag); LINT_INIT(length); - end= page+getint(page); - nod_flag=test_if_nod(page); - page+=2+nod_flag; - *ret_pos=page; - while (page < end) - { - length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,t_buff); - if ((flag=_nisam_key_cmp(keyinfo->seg,t_buff,key,key_len,comp_flag)) >= 0) - break; -#ifdef EXTRA_DEBUG - DBUG_PRINT("loop",("page: %lx key: '%s' flag: %d",page,t_buff,flag)); -#endif - memcpy(buff,t_buff,length); - *ret_pos=page; - } - if (flag == 0) - memcpy(buff,t_buff,length); /* Result is first key */ - DBUG_PRINT("exit",("flag: %d ret_pos: %lx",flag,*ret_pos)); - DBUG_RETURN(flag); -} /* _nisam_seq_search */ - - - /* Get pos to a key_block */ - -ulong _nisam_kpos(uint nod_flag, uchar *after_key) -{ - after_key-=nod_flag; - switch (nod_flag) { - case 3: - return uint3korr(after_key)*512L; - case 2: - return uint2korr(after_key)*512L; - case 1: - return (uint) (*after_key)*512L; - case 0: /* At leaf page */ - default: /* Impossible */ - return(NI_POS_ERROR); - } -} /* _kpos */ - - - /* Save pos to a key_block */ - -void _nisam_kpointer(register N_INFO *info, register uchar *buff, ulong pos) -{ - pos/=512L; - switch (info->s->base.key_reflength) { - case 3: int3store(buff,pos); break; - case 2: int2store(buff,(uint) pos); break; - case 1: buff[0]= (uchar) pos; break; - default: abort(); /* impossible */ - } -} /* _nisam_kpointer */ - - - /* Calc pos to a data-record */ - -ulong _nisam_dpos(N_INFO *info, uint nod_flag, uchar *after_key) -{ - ulong pos; - after_key-=(nod_flag + info->s->rec_reflength); - switch (info->s->rec_reflength) { - case 4: - pos= (ulong) uint4korr(after_key); - break; - case 3: - pos= (ulong) uint3korr(after_key); - break; - case 2: - pos= (ulong) uint2korr(after_key); - break; - default: - pos=0L; /* Shut compiler up */ - } - return (info->s->base.options & - (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) ? pos : - pos*info->s->base.reclength; -} - - /* save pos to record */ - -void _nisam_dpointer(N_INFO *info, uchar *buff, ulong pos) -{ - if (!(info->s->base.options & - (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD))) - pos/=info->s->base.reclength; - - switch (info->s->rec_reflength) { - case 4: int4store(buff,pos); break; - case 3: int3store(buff,pos); break; - case 2: int2store(buff,(uint) pos); break; - default: abort(); /* Impossible */ - } -} /* _nisam_dpointer */ - - - /* - ** Compare two keys with is bigger - ** Returns <0, 0, >0 acording to with is bigger - ** Key_length specifies length of key to use. Number-keys can't - ** be splitted - ** If flag <> SEARCH_FIND compare also position - */ -int _nisam_key_cmp(register N_KEYSEG *keyseg, register uchar *a, register uchar *b, uint key_length, uint nextflag) -{ - reg4 int flag,length_diff; - int16 s_1,s_2; - int32 l_1,l_2; - uint32 u_1,u_2; - float f_1,f_2; - double d_1,d_2; - reg5 uchar *end; - - if (!(nextflag & (SEARCH_FIND | SEARCH_NO_FIND | SEARCH_LAST)) - || key_length == 0) - key_length=N_MAX_KEY_BUFF*2; - - for ( ; (int) key_length >0 ; key_length-= (keyseg++)->base.length) - { - end= a+ min(keyseg->base.length,key_length); - switch ((enum ha_base_keytype) keyseg->base.type) { - case HA_KEYTYPE_TEXT: /* Ascii; Key is converted */ - case HA_KEYTYPE_BINARY: - if (keyseg->base.flag & HA_SPACE_PACK) - { - uchar *as, *bs; - int length,b_length; - - as=a++; bs=b++; - length= (length_diff= ((int) *as - (b_length= (int) *bs))) < 0 ? - (int) *as : b_length; - end= a+ min(key_length,(uint) length); - - if (use_strnxfrm(default_charset_info)) { - if (((enum ha_base_keytype) keyseg->base.type) == HA_KEYTYPE_BINARY) - { - while (a < end) - if ((flag= (int) *a++ - (int) *b++)) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - } - else - { - if ((flag = my_strnncoll(default_charset_info, - a, (int) (end-a), b, b_length))) - return (keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag; - b+= (uint) (end-a); - a=end; - } - } - else - { - while (a < end) - if ((flag= (int) *a++ - (int) *b++)) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - } - if (key_length < (uint) keyseg->base.length) - { /* key_part */ - if (length_diff) - { - if (length_diff < 0 || (uint) *as <= key_length) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? - -length_diff : length_diff); - for (length= (int) key_length-b_length; length-- > 0 ;) - { - if (*a++ != ' ') - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -1 : 1); - } - } - if (nextflag & SEARCH_NO_FIND) /* Find record after key */ - return (nextflag & SEARCH_BIGGER) ? -1 : 1; - return 0; - } - else - { - if (length_diff) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? - -length_diff : length_diff); - } - a=as+ (uint) *as+1 ; b= bs+ b_length+1; /* to next key */ - } - else - { - if (use_strnxfrm(default_charset_info)) { - if (((enum ha_base_keytype) keyseg->base.type) == HA_KEYTYPE_BINARY) - { - while (a < end) - if ((flag= (int) *a++ - (int) *b++)) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - } - else - { - if ((flag = my_strnncoll(default_charset_info, - a, (int) (end-a), b, (int) (end-a)))) - return (keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag; - b+= (uint) (end-a); - a=end; - } - } - else - { - while (a < end) - if ((flag= (int) *a++ - (int) *b++)) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - } - } - break; - case HA_KEYTYPE_INT8: - { - int i_1= (int) *((signed char*) a); - int i_2= (int) *((signed char*) b); - if ((flag = CMP(i_1,i_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b++; - break; - } - case HA_KEYTYPE_SHORT_INT: - shortget(s_1,a); - shortget(s_2,b); - if ((flag = CMP(s_1,s_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= 2; /* sizeof(short int); */ - break; - case HA_KEYTYPE_USHORT_INT: - { - uint16 us_1,us_2; - ushortget(us_1,a); - ushortget(us_2,b); - if ((flag = CMP(us_1,us_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+=2; /* sizeof(short int); */ - break; - } - case HA_KEYTYPE_LONG_INT: - longget(l_1,a); - longget(l_2,b); - if ((flag = CMP(l_1,l_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= 4; /* sizeof(long int); */ - break; - case HA_KEYTYPE_ULONG_INT: - ulongget(u_1,a); - ulongget(u_2,b); - if ((flag = CMP(u_1,u_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= 4; /* sizeof(long int); */ - break; - case HA_KEYTYPE_INT24: - l_1=sint3korr(a); - l_2=sint3korr(b); - if ((flag = CMP(l_1,l_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= 3; - break; - case HA_KEYTYPE_UINT24: - l_1=(long) uint3korr(a); - l_2=(long) uint3korr(b); - if ((flag = CMP(l_1,l_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= 3; - break; - case HA_KEYTYPE_FLOAT: - bmove((byte*) &f_1,(byte*) a,(int) sizeof(float)); - bmove((byte*) &f_2,(byte*) b,(int) sizeof(float)); - if ((flag = CMP(f_1,f_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= sizeof(float); - break; - case HA_KEYTYPE_DOUBLE: - doubleget(d_1,a); - doubleget(d_2,b); - if ((flag = CMP(d_1,d_2))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= sizeof(double); - break; - case HA_KEYTYPE_NUM: /* Numeric key */ - { - int swap_flag=keyseg->base.flag & HA_REVERSE_SORT; - if (keyseg->base.flag & HA_SPACE_PACK) - { - int alength,blength; - - if (swap_flag) - swap_variables(uchar*, a, b); - alength= *a++; blength= *b++; - if ((flag=(int) (keyseg->base.length-key_length)) < 0) - flag=0; - if (alength != blength+flag) - { - if ((alength > blength+flag && *a != '-') || - (alength < blength+flag && *b == '-')) - return 1; - else - return -1; - } - if (*a == '-' && *b == '-') - { - swap_flag=1; - swap_variables(uchar*, a, b); - } - end=a+alength; - while (a < end) - if (*a++ != *b++) - { - a--; b--; - if (my_isdigit(default_charset_info, (char) *a) && - my_isdigit(default_charset_info, (char) *b)) - return ((int) *a - (int) *b); - if (*a == '-' || my_isdigit(default_charset_info,(char) *b)) - return (-1); - if (*b == '-' || *b++ == ' ' || - my_isdigit(default_charset_info,(char) *a)) - return (1); - if (*a++ == ' ') - return (-1); - } - } - else - { - for ( ; a < end && *a == ' ' && *b == ' ' ; a++, b++) ; - if (*a == '-' && *b == '-') - swap_flag=1; - if (swap_flag) - { - end=b+(int) (end-a); - swap_variables(uchar*, a, b); - } - while (a < end) - if (*a++ != *b++) - { - a--; b--; - if (my_isdigit(default_charset_info,(char) *a) && - my_isdigit(default_charset_info,(char) *b)) - return ((int) *a - (int) *b); - if (*a == '-' || my_isdigit(default_charset_info,(char) *b)) - return (-1); - if (*b == '-' || *b++ == ' ' || - my_isdigit(default_charset_info,(char) *a)) - return (1); - if (*a++ == ' ') - return -1; - } - } - if (swap_flag) - swap_variables(uchar*, a, b); - break; - } -#ifdef HAVE_LONG_LONG - case HA_KEYTYPE_LONGLONG: - { - longlong ll_a,ll_b; - longlongget(ll_a,a); - longlongget(ll_b,b); - if ((flag = CMP(ll_a,ll_b))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= sizeof(longlong); - break; - } - case HA_KEYTYPE_ULONGLONG: - { - ulonglong ll_a,ll_b; - longlongget(ll_a,a); - longlongget(ll_b,b); - if ((flag = CMP(ll_a,ll_b))) - return ((keyseg->base.flag & HA_REVERSE_SORT) ? -flag : flag); - a= end; - b+= sizeof(ulonglong); - break; - } -#endif - case HA_KEYTYPE_END: /* Ready */ - case HA_KEYTYPE_VARTEXT: /* Impossible */ - case HA_KEYTYPE_VARBINARY: /* Impossible */ - goto end; - } - } -end: - if (!(nextflag & SEARCH_FIND)) - { - if (nextflag & (SEARCH_NO_FIND | SEARCH_LAST)) /* Find record after key */ - return (nextflag & (SEARCH_BIGGER | SEARCH_LAST)) ? -1 : 1; - LINT_INIT(l_1); LINT_INIT(l_2); - switch (keyseg->base.length) { - case 4: - u_1= (ulong) uint4korr(a); - u_2= (ulong) uint4korr(b); - break; - case 3: - u_1= (ulong) uint3korr(a); - u_2= (ulong) uint3korr(b); - break; - case 2: - u_1= (ulong) uint2korr(a); - u_2= (ulong) uint2korr(b); - break; - default: abort(); /* Impossible */ - } - flag = CMP(u_1,u_2); - - if (nextflag & SEARCH_SAME) - return (flag); /* read same */ - if (nextflag & SEARCH_BIGGER) - return (flag <= 0 ? -1 : 1); /* read next */ - return (flag < 0 ? -1 : 1); /* read previous */ - } - return 0; -} /* _nisam_key_cmp */ - - - /* Get key from key-block */ - /* page points at previous key; its advanced to point at next key */ - /* key should contain previous key */ - /* Returns length of found key + pointers */ - /* nod_flag is a flag if we are on nod */ - -uint _nisam_get_key(register N_KEYDEF *keyinfo, uint nod_flag, - register uchar **page, register uchar *key) -{ - reg1 N_KEYSEG *keyseg; - uchar *start,*start_key; - uint length,c_length; - - LINT_INIT(start); - start_key=key; c_length=0; - for (keyseg=keyinfo->seg ; keyseg->base.type ;keyseg++) - { - if (keyseg->base.flag & (HA_SPACE_PACK | HA_PACK_KEY)) - { - start=key; - if (keyseg->base.flag & HA_SPACE_PACK) - key++; - if ((length= *(*page)++) & 128) - { - key+= (c_length=(length & 127)); - if (c_length == 0) /* Same key */ - { - key+= *start; /* Same diff_key as prev */ - length=0; - } - else - { - if (keyseg->base.flag & HA_SPACE_PACK) - length= *(*page)++; - else - length=keyseg->base.length-length+128; /* Rest of key */ - /* Prevent core dumps if wrong data formats */ - if (length > keyseg->base.length) - length=0; - } - } - } - else - length=keyseg->base.length; - memcpy((byte*) key,(byte*) *page,(size_t) length); key+=length; - if (keyseg->base.flag & HA_SPACE_PACK) - *start= (uchar) ((key-start)-1); - *page+=length; - } - length=keyseg->base.length+nod_flag; - bmove((byte*) key,(byte*) *page,length); - *page+=length; - return((uint) (key-start_key)+keyseg->base.length); -} /* _nisam_get_key */ - - - /* same as _nisam_get_key but used with fixed length keys */ - -uint _nisam_get_static_key(register N_KEYDEF *keyinfo, uint nod_flag, register uchar **page, register uchar *key) -{ - memcpy((byte*) key,(byte*) *page, - (size_t) (keyinfo->base.keylength+nod_flag)); - *page+=keyinfo->base.keylength+nod_flag; - return(keyinfo->base.keylength); -} /* _nisam_get_static_key */ - - - /* Get last key from key-block, starting from keypos */ - /* Return pointer to where keystarts */ - -uchar *_nisam_get_last_key(N_INFO *info, N_KEYDEF *keyinfo, uchar *keypos, uchar *lastkey, uchar *endpos) -{ - uint nod_flag; - uchar *lastpos; - - nod_flag=test_if_nod(keypos); - if (! (keyinfo->base.flag & (HA_PACK_KEY | HA_SPACE_PACK_USED))) - { - lastpos=endpos-keyinfo->base.keylength-nod_flag; - if (lastpos > keypos) - bmove((byte*) lastkey,(byte*) lastpos,keyinfo->base.keylength+nod_flag); - } - else - { - lastpos=0 ; keypos+=2+nod_flag; - lastkey[0]=0; - while (keypos < endpos) - { - lastpos=keypos; - VOID(_nisam_get_key(keyinfo,nod_flag,&keypos,lastkey)); - } - } - return lastpos; -} /* _nisam_get_last_key */ - - - /* Calculate length of key */ - -uint _nisam_keylength(N_KEYDEF *keyinfo, register uchar *key) -{ - reg1 N_KEYSEG *keyseg; - uchar *start; - - if (! (keyinfo->base.flag & HA_SPACE_PACK_USED)) - return (keyinfo->base.keylength); - - start=key; - for (keyseg=keyinfo->seg ; keyseg->base.type ; keyseg++) - { - if (keyseg->base.flag & HA_SPACE_PACK) - key+= *key+1; - else - key+= keyseg->base.length; - } - return((uint) (key-start)+keyseg->base.length); -} /* _nisam_keylength */ - - - /* Move a key */ - -uchar *_nisam_move_key(N_KEYDEF *keyinfo, uchar *to, uchar *from) -{ - reg1 uint length; - memcpy((byte*) to, (byte*) from, - (size_t) (length=_nisam_keylength(keyinfo,from))); - return to+length; -} - - /* Find next/previous record with same key */ - /* This can't be used when database is touched after last read */ - -int _nisam_search_next(register N_INFO *info, register N_KEYDEF *keyinfo, - uchar *key, uint nextflag, ulong pos) -{ - int error; - uint nod_flag; - uchar lastkey[N_MAX_KEY_BUFF]; - DBUG_ENTER("_nisam_search_next"); - DBUG_PRINT("enter",("nextflag: %d lastpos: %d int_keypos: %lx", - nextflag,info->lastpos,info->int_keypos)); - DBUG_EXECUTE("key",_nisam_print_key(DBUG_FILE,keyinfo->seg,key);); - - if ((nextflag & SEARCH_BIGGER && info->int_keypos >= info->int_maxpos) || - info->int_pos == NI_POS_ERROR || info->page_changed) - DBUG_RETURN(_nisam_search(info,keyinfo,key,0,nextflag | SEARCH_SAVE_BUFF, - pos)); - - if (info->buff_used) - { - if (!_nisam_fetch_keypage(info,keyinfo,info->last_search_keypage, - info->buff,0)) - { - info->lastpos= NI_POS_ERROR; - DBUG_RETURN(-1); - } - info->buff_used=0; - } - - /* Last used buffer is in info->buff */ - - nod_flag=test_if_nod(info->buff); - VOID(_nisam_move_key(keyinfo,lastkey,key)); - - if (nextflag & SEARCH_BIGGER) /* Next key */ - { - ulong tmp_pos=_nisam_kpos(nod_flag,info->int_keypos); - if (tmp_pos != NI_POS_ERROR) - { - if ((error=_nisam_search(info,keyinfo,key,0,nextflag | SEARCH_SAVE_BUFF, - tmp_pos)) <=0) - DBUG_RETURN(error); - } - VOID((*keyinfo->get_key)(keyinfo,nod_flag,&info->int_keypos,lastkey)); - } - else /* Previous key */ - { - info->int_keypos=_nisam_get_last_key(info,keyinfo,info->buff,lastkey, - info->int_keypos); - if (info->int_keypos == info->buff+2) - DBUG_RETURN(_nisam_search(info,keyinfo,key,0,nextflag | SEARCH_SAVE_BUFF, - pos)); - if ((error=_nisam_search(info,keyinfo,key,0,nextflag | SEARCH_SAVE_BUFF, - _nisam_kpos(nod_flag,info->int_keypos))) <= 0) - DBUG_RETURN(error); - } - - info->int_keypos=_nisam_get_last_key(info,keyinfo,info->buff,lastkey, - info->int_keypos); - VOID(_nisam_move_key(keyinfo,info->lastkey,lastkey)); - VOID((*keyinfo->get_key)(keyinfo,nod_flag,&info->int_keypos,info->lastkey)); - info->lastpos=_nisam_dpos(info,nod_flag,info->int_keypos); - DBUG_PRINT("exit",("found key at %d",info->lastpos)); - DBUG_RETURN(0); -} /* _nisam_search_next */ - - - /* S|ker reda p} positionen f|r f|rsta recordet i ett index */ - /* Positionen l{ggs i info->lastpos */ - -int _nisam_search_first(register N_INFO *info, register N_KEYDEF *keyinfo, register ulong pos) -{ - uint nod_flag; - uchar *page; - DBUG_ENTER("_nisam_search_first"); - - if (pos == NI_POS_ERROR) - { - my_errno=HA_ERR_KEY_NOT_FOUND; - info->lastpos= NI_POS_ERROR; - DBUG_RETURN(-1); - } - - do - { - if (!_nisam_fetch_keypage(info,keyinfo,pos,info->buff,0)) - { - info->lastpos= NI_POS_ERROR; - DBUG_RETURN(-1); - } - nod_flag=test_if_nod(info->buff); - page=info->buff+2+nod_flag; - } while ((pos=_nisam_kpos(nod_flag,page)) != NI_POS_ERROR); - - VOID((*keyinfo->get_key)(keyinfo,nod_flag,&page,info->lastkey)); - info->int_keypos=page; info->int_maxpos=info->buff+getint(info->buff)-1; - info->lastpos=_nisam_dpos(info,nod_flag,page); - info->page_changed=info->buff_used=0; - info->last_search_keypage=info->int_pos; - - DBUG_PRINT("exit",("found key at %d",info->lastpos)); - DBUG_RETURN(0); -} /* _nisam_search_first */ - - - /* S|ker reda p} positionen f|r sista recordet i ett index */ - /* Positionen l{ggs i info->lastpos */ - -int _nisam_search_last(register N_INFO *info, register N_KEYDEF *keyinfo, register ulong pos) -{ - uint nod_flag; - uchar *buff,*page; - DBUG_ENTER("_nisam_search_last"); - - if (pos == NI_POS_ERROR) - { - my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ - info->lastpos= NI_POS_ERROR; - DBUG_RETURN(-1); - } - - buff=info->buff; - do - { - if (!_nisam_fetch_keypage(info,keyinfo,pos,buff,0)) - { - info->lastpos= NI_POS_ERROR; - DBUG_RETURN(-1); - } - page= buff+getint(buff); - nod_flag=test_if_nod(buff); - } while ((pos=_nisam_kpos(nod_flag,page)) != NI_POS_ERROR); - - VOID(_nisam_get_last_key(info,keyinfo,buff,info->lastkey,page)); - info->lastpos=_nisam_dpos(info,nod_flag,page); - info->int_keypos=info->int_maxpos=page; - info->page_changed=info->buff_used=0; - info->last_search_keypage=info->int_pos; - - DBUG_PRINT("exit",("found key at %d",info->lastpos)); - DBUG_RETURN(0); -} /* _nisam_search_last */ |