diff options
Diffstat (limited to 'storage/myisam/mi_search.c')
| -rw-r--r-- | storage/myisam/mi_search.c | 1927 |
1 files changed, 1927 insertions, 0 deletions
diff --git a/storage/myisam/mi_search.c b/storage/myisam/mi_search.c new file mode 100644 index 00000000..14286e35 --- /dev/null +++ b/storage/myisam/mi_search.c @@ -0,0 +1,1927 @@ +/* + Copyright (c) 2000, 2010, Oracle and/or its affiliates + + 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 St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* key handling functions */ + +#include "fulltext.h" +#include "m_ctype.h" + +static my_bool _mi_get_prev_key(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uchar *keypos, + uint *return_key_length); + + /* Check index */ + +int _mi_check_index(MI_INFO *info, int inx) +{ + if (inx == -1) /* Use last index */ + inx=info->lastinx; + if (inx < 0) + { + my_errno= HA_ERR_WRONG_INDEX; + return -1; + } + if (!mi_is_key_active(info->s->state.key_map, inx)) + { + my_errno= info->s->state.state.records ? HA_ERR_WRONG_INDEX : + HA_ERR_END_OF_FILE; + return -1; + } + if (info->lastinx != inx) /* Index changed */ + { + info->lastinx = inx; + info->page_changed=1; + 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); +} /* mi_check_index */ + + + /* + ** Search after row by a key + ** Position to row is stored in info->lastpos + ** Return: -1 if not found + ** 1 if one should continue search on higher level + */ + +int _mi_search(register MI_INFO *info, register MI_KEYDEF *keyinfo, + uchar *key, uint key_len, uint nextflag, register my_off_t pos) +{ + my_bool last_key; + int error,flag; + uint nod_flag; + uchar *keypos,*maxpos; + uchar lastkey[HA_MAX_KEY_BUFF],*buff; + DBUG_ENTER("_mi_search"); + DBUG_PRINT("enter",("pos: %lu nextflag: %u lastpos: %lu", + (ulong) pos, nextflag, (ulong) info->lastpos)); + DBUG_EXECUTE("key",_mi_print_key(DBUG_FILE,keyinfo->seg,key,key_len);); + + if (pos == HA_OFFSET_ERROR) + { + my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ + info->lastpos= HA_OFFSET_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=_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff, + MY_TEST(!(nextflag & SEARCH_SAVE_BUFF))))) + goto err; + DBUG_DUMP("page", buff, mi_getint(buff)); + + flag=(*keyinfo->bin_search)(info,keyinfo,buff,key,key_len,nextflag, + &keypos,lastkey, &last_key); + if (flag == MI_FOUND_WRONG_KEY) + { + my_errno= HA_ERR_CRASHED; + goto err; + } + nod_flag=mi_test_if_nod(buff); + maxpos=buff+mi_getint(buff)-1; + + if (flag) + { + if ((error=_mi_search(info,keyinfo,key,key_len,nextflag, + _mi_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) && nod_flag && + ((keyinfo->flag & (HA_NOSAME | HA_NULL_PART)) != HA_NOSAME || + key_len != USE_WHOLE_KEY)) + { + if ((error=_mi_search(info,keyinfo,key,key_len,SEARCH_FIND, + _mi_kpos(nod_flag,keypos))) >= 0 || + my_errno != HA_ERR_KEY_NOT_FOUND) + DBUG_RETURN(error); + info->last_keypage= HA_OFFSET_ERROR; /* Buffer not in mem */ + } + } + if (pos != info->last_keypage) + { + uchar *old_buff=buff; + if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff, + MY_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) + { + uint not_used[2]; + if (_mi_get_prev_key(info,keyinfo, buff, info->lastkey, keypos, + &info->lastkey_length)) + goto err; + if (!(nextflag & SEARCH_SMALLER) && + ha_key_cmp(keyinfo->seg, info->lastkey, key, key_len, SEARCH_FIND, + not_used)) + { + my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ + goto err; + } + } + else + { + info->lastkey_length=(*keyinfo->get_key)(keyinfo,nod_flag,&keypos,lastkey); + if (!info->lastkey_length) + goto err; + memcpy(info->lastkey,lastkey,info->lastkey_length); + } + info->lastpos=_mi_dpos(info,0,info->lastkey+info->lastkey_length); + /* Save position for a possible read next / previous */ + info->int_keypos=info->buff+ (keypos-buff); + info->int_maxpos=info->buff+ (maxpos-buff); + info->int_nod_flag=nod_flag; + info->int_keytree_version=keyinfo->version; + info->last_search_keypage=info->last_keypage; + info->page_changed=0; + info->buff_used= (info->buff != buff); /* If we have to reread buff */ + + DBUG_PRINT("exit",("found key at %lu",(ulong) info->lastpos)); + DBUG_RETURN(0); + +err: + DBUG_PRINT("exit",("Error: %d",my_errno)); + info->lastpos= HA_OFFSET_ERROR; + info->page_changed=1; + DBUG_RETURN (-1); +} /* _mi_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 _mi_bin_search(MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uint key_len, uint comp_flag, uchar **ret_pos, + uchar *buff __attribute__((unused)), my_bool *last_key) +{ + reg4 int start,mid,end,save_end; + int UNINIT_VAR(flag); + uint totlength,nod_flag,not_used[2]; + DBUG_ENTER("_mi_bin_search"); + + totlength=keyinfo->keylength+(nod_flag=mi_test_if_nod(page)); + start=0; mid=1; + save_end=end=(int) ((mi_getint(page)-2-nod_flag)/totlength-1); + DBUG_PRINT("test",("mi_getint: %d end: %d",mi_getint(page),end)); + page+=2+nod_flag; + + while (start != end) + { + mid= (start+end)/2; + if ((flag=ha_key_cmp(keyinfo->seg,page+(uint) mid*totlength,key,key_len, + comp_flag, not_used)) + >= 0) + end=mid; + else + start=mid+1; + } + if (mid != start) + flag=ha_key_cmp(keyinfo->seg,page+(uint) start*totlength,key,key_len, + comp_flag, not_used); + if (flag < 0) + start++; /* point at next, bigger key */ + *ret_pos=page+(uint) start*totlength; + *last_key= end == save_end; + DBUG_PRINT("exit",("flag: %d keypos: %d",flag,start)); + DBUG_RETURN(flag); +} /* _mi_bin_search */ + + +/* + Locate a packed key in a key page. + + SYNOPSIS + _mi_seq_search() + info Open table information. + keyinfo Key definition information. + page Key page (beginning). + key Search key. + key_len Length to use from search key or USE_WHOLE_KEY + comp_flag Search flags like SEARCH_SAME etc. + ret_pos RETURN Position in key page behind this key. + buff RETURN Copy of previous or identical unpacked key. + last_key RETURN If key is last in page. + + DESCRIPTION + Used instead of _mi_bin_search() when key is packed. + Puts smaller or identical key in buff. + Key is searched sequentially. + + RETURN + > 0 Key in 'buff' is smaller than search key. + 0 Key in 'buff' is identical to search key. + < 0 Not found. +*/ + +int _mi_seq_search(MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uint key_len, uint comp_flag, uchar **ret_pos, + uchar *buff, my_bool *last_key) +{ + int UNINIT_VAR(flag); + uint nod_flag,UNINIT_VAR(length),not_used[2]; + uchar t_buff[HA_MAX_KEY_BUFF],*end; + DBUG_ENTER("_mi_seq_search"); + + end= page+mi_getint(page); + nod_flag=mi_test_if_nod(page); + page+=2+nod_flag; + *ret_pos=page; + t_buff[0]=0; /* Avoid bugs */ + while (page < end) + { + length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,t_buff); + if (length == 0 || page > end) + { + mi_print_error(info->s, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + DBUG_PRINT("error", + ("Found wrong key: length: %u page: %p end: %p", + length, page, end)); + DBUG_RETURN(MI_FOUND_WRONG_KEY); + } + if ((flag=ha_key_cmp(keyinfo->seg,t_buff,key,key_len,comp_flag, + not_used)) >= 0) + break; +#ifdef EXTRA_DEBUG + DBUG_PRINT("loop",("page: 0x%lx key: '%s' flag: %d", (long) 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 */ + *last_key= page == end; + DBUG_PRINT("exit",("flag: %d ret_pos: %p", flag, *ret_pos)); + DBUG_RETURN(flag); +} /* _mi_seq_search */ + + +int _mi_prefix_search(MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uint key_len, uint nextflag, uchar **ret_pos, + uchar *buff, my_bool *last_key) +{ + /* + my_flag is raw comparison result to be changed according to + SEARCH_NO_FIND,SEARCH_LAST and HA_REVERSE_SORT flags. + flag is the value returned by ha_key_cmp and as treated as final + */ + int flag=0, my_flag=-1; + uint nod_flag, UNINIT_VAR(length), len, matched, cmplen, kseg_len; + uint UNINIT_VAR(prefix_len), suffix_len; + int key_len_skip, UNINIT_VAR(seg_len_pack), key_len_left; + uchar *end, *kseg, *vseg; + const uchar *sort_order= keyinfo->seg->charset->sort_order; + uchar tt_buff[HA_MAX_KEY_BUFF+2], *t_buff=tt_buff+2; + uchar *UNINIT_VAR(saved_from), *UNINIT_VAR(saved_to); + uchar *UNINIT_VAR(saved_vseg); + uint saved_length=0, saved_prefix_len=0; + uint length_pack; + DBUG_ENTER("_mi_prefix_search"); + + t_buff[0]=0; /* Avoid bugs */ + end= page+mi_getint(page); + nod_flag=mi_test_if_nod(page); + page+=2+nod_flag; + *ret_pos=page; + kseg=key; + + get_key_pack_length(kseg_len,length_pack,kseg); + key_len_skip=length_pack+kseg_len; + key_len_left=(int) key_len- (int) key_len_skip; + /* If key_len is 0, then lenght_pack is 1, then key_len_left is -1. */ + cmplen=(key_len_left>=0) ? kseg_len : key_len-length_pack; + DBUG_PRINT("info",("key: '%.*s'",kseg_len,kseg)); + + /* + Keys are compressed the following way: + + If the max length of first key segment <= 127 bytes the prefix is + 1 byte else it's 2 byte + + (prefix) length The high bit is set if this is a prefix for the prev key. + [suffix length] Packed length of suffix if the previous was a prefix. + (suffix) data Key data bytes (past the common prefix or whole segment). + [next-key-seg] Next key segments (([packed length], data), ...) + pointer Reference to the data file (last_keyseg->length). + */ + + matched=0; /* how many char's from prefix were alredy matched */ + len=0; /* length of previous key unpacked */ + + while (page < end) + { + uint packed= *page & 128; + + vseg=page; + if (keyinfo->seg->length >= 127) + { + suffix_len=mi_uint2korr(vseg) & 32767; + vseg+=2; + } + else + suffix_len= *vseg++ & 127; + + if (packed) + { + if (suffix_len == 0) + { + /* == 0x80 or 0x8000, same key, prefix length == old key length. */ + prefix_len=len; + } + else + { + /* > 0x80 or 0x8000, this is prefix lgt, packed suffix lgt follows. */ + prefix_len=suffix_len; + get_key_length(suffix_len,vseg); + } + } + else + { + /* Not packed. No prefix used from last key. */ + prefix_len=0; + } + + len=prefix_len+suffix_len; + seg_len_pack=get_pack_length(len); + t_buff=tt_buff+3-seg_len_pack; + store_key_length(t_buff,len); + + if (prefix_len > saved_prefix_len) + memcpy(t_buff+seg_len_pack+saved_prefix_len,saved_vseg, + prefix_len-saved_prefix_len); + saved_vseg=vseg; + saved_prefix_len=prefix_len; + + DBUG_PRINT("loop",("page: '%.*s%.*s'",prefix_len,t_buff+seg_len_pack, + suffix_len,vseg)); + { + uchar *from=vseg+suffix_len; + HA_KEYSEG *keyseg; + uint l; + + for (keyseg=keyinfo->seg+1 ; keyseg->type ; keyseg++ ) + { + + if (keyseg->flag & HA_NULL_PART) + { + if (!(*from++)) + continue; + } + if (keyseg->flag & (HA_VAR_LENGTH_PART | HA_BLOB_PART | HA_SPACE_PACK)) + { + get_key_length(l,from); + } + else + l=keyseg->length; + + from+=l; + } + from+=keyseg->length; + page=from+nod_flag; + length= (uint) (from - vseg); + } + + if (page > end) + { + mi_print_error(info->s, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + DBUG_PRINT("error", + ("Found wrong key: length: %u page: %p end: %p", + length, page, end)); + DBUG_RETURN(MI_FOUND_WRONG_KEY); + } + + if (matched >= prefix_len) + { + /* We have to compare. But we can still skip part of the key */ + uint left; + uchar *k=kseg+prefix_len; + + /* + If prefix_len > cmplen then we are in the end-space comparison + phase. Do not try to access the key any more ==> left= 0. + */ + left= ((len <= cmplen) ? suffix_len : + ((prefix_len < cmplen) ? cmplen - prefix_len : 0)); + + matched=prefix_len+left; + + if (sort_order) + { + for (my_flag=0;left;left--) + if ((my_flag= (int) sort_order[*vseg++] - (int) sort_order[*k++])) + break; + } + else + { + for (my_flag=0;left;left--) + if ((my_flag= (int) *vseg++ - (int) *k++)) + break; + } + + if (my_flag>0) /* mismatch */ + break; + if (my_flag==0) /* match */ + { + /* + ** len cmplen seg_left_len more_segs + ** < matched=len; continue search + ** > = prefix ? found : (matched=len; continue search) + ** > < - ok, found + ** = < - ok, found + ** = = - ok, found + ** = = + next seg + */ + if (len < cmplen) + { + if ((keyinfo->seg->type != HA_KEYTYPE_TEXT && + keyinfo->seg->type != HA_KEYTYPE_VARTEXT1 && + keyinfo->seg->type != HA_KEYTYPE_VARTEXT2)) + my_flag= -1; + else + { + /* We have to compare k and vseg as if they were space extended */ + uchar *k_end= k+ (cmplen - len); + for ( ; k < k_end && *k == ' '; k++) ; + if (k == k_end) + goto cmp_rest; /* should never happen */ + if (*k < (uchar) ' ') + { + my_flag= 1; /* Compared string is smaller */ + break; + } + my_flag= -1; /* Continue searching */ + } + } + else if (len > cmplen) + { + uchar *vseg_end; + if ((nextflag & SEARCH_PREFIX) && key_len_left == 0) + goto fix_flag; + + /* We have to compare k and vseg as if they were space extended */ + for (vseg_end= vseg + (len-cmplen) ; + vseg < vseg_end && *vseg == (uchar) ' '; + vseg++, matched++) ; + DBUG_ASSERT(vseg < vseg_end); + + if (*vseg > (uchar) ' ') + { + my_flag= 1; /* Compared string is smaller */ + break; + } + my_flag= -1; /* Continue searching */ + } + else + { + cmp_rest: + if (key_len_left>0) + { + uint not_used[2]; + if ((flag = ha_key_cmp(keyinfo->seg+1,vseg, + k, key_len_left, nextflag, not_used)) >= 0) + break; + } + else + { + /* + at this line flag==-1 if the following lines were already + visited and 0 otherwise, i.e. flag <=0 here always !!! + */ + fix_flag: + DBUG_ASSERT(flag <= 0); + if (nextflag & (SEARCH_NO_FIND | SEARCH_LAST)) + flag=(nextflag & (SEARCH_BIGGER | SEARCH_LAST)) ? -1 : 1; + if (flag>=0) + break; + } + } + } + matched-=left; + } + /* else (matched < prefix_len) ---> do nothing. */ + + memcpy(buff,t_buff,saved_length=seg_len_pack+prefix_len); + saved_to=buff+saved_length; + saved_from=saved_vseg; + saved_length=length; + *ret_pos=page; + } + if (my_flag) + flag=(keyinfo->seg->flag & HA_REVERSE_SORT) ? -my_flag : my_flag; + if (flag == 0) + { + memcpy(buff,t_buff,saved_length=seg_len_pack+prefix_len); + saved_to=buff+saved_length; + saved_from=saved_vseg; + saved_length=length; + } + if (saved_length) + memcpy(saved_to,saved_from,saved_length); + + *last_key= page == end; + + DBUG_PRINT("exit",("flag: %d ret_pos: %p", flag, *ret_pos)); + DBUG_RETURN(flag); +} /* _mi_prefix_search */ + + + /* Get pos to a key_block */ + +my_off_t _mi_kpos(uint nod_flag, uchar *after_key) +{ + after_key-=nod_flag; + switch (nod_flag) { +#if SIZEOF_OFF_T > 4 + case 7: + return mi_uint7korr(after_key)*MI_MIN_KEY_BLOCK_LENGTH; + case 6: + return mi_uint6korr(after_key)*MI_MIN_KEY_BLOCK_LENGTH; + case 5: + return mi_uint5korr(after_key)*MI_MIN_KEY_BLOCK_LENGTH; +#else + case 7: + after_key++; + case 6: + after_key++; + case 5: + after_key++; +#endif + case 4: + return ((my_off_t) mi_uint4korr(after_key))*MI_MIN_KEY_BLOCK_LENGTH; + case 3: + return ((my_off_t) mi_uint3korr(after_key))*MI_MIN_KEY_BLOCK_LENGTH; + case 2: + return (my_off_t) (mi_uint2korr(after_key)*MI_MIN_KEY_BLOCK_LENGTH); + case 1: + return (uint) (*after_key)*MI_MIN_KEY_BLOCK_LENGTH; + case 0: /* At leaf page */ + default: /* Impossible */ + return(HA_OFFSET_ERROR); + } +} /* _kpos */ + + + /* Save pos to a key_block */ + +void _mi_kpointer(register MI_INFO *info, register uchar *buff, my_off_t pos) +{ + pos/=MI_MIN_KEY_BLOCK_LENGTH; + switch (info->s->base.key_reflength) { +#if SIZEOF_OFF_T > 4 + case 7: mi_int7store(buff,pos); break; + case 6: mi_int6store(buff,pos); break; + case 5: mi_int5store(buff,pos); break; +#else + case 7: *buff++=0; + /* fall through */ + case 6: *buff++=0; + /* fall through */ + case 5: *buff++=0; + /* fall through */ +#endif + case 4: mi_int4store(buff,pos); break; + case 3: mi_int3store(buff,pos); break; + case 2: mi_int2store(buff,(uint) pos); break; + case 1: buff[0]= (uchar) pos; break; + default: abort(); /* impossible */ + } +} /* _mi_kpointer */ + + + /* Calc pos to a data-record from a key */ + + +my_off_t _mi_dpos(MI_INFO *info, uint nod_flag, uchar *after_key) +{ + my_off_t pos; + after_key-=(nod_flag + info->s->rec_reflength); + switch (info->s->rec_reflength) { +#if SIZEOF_OFF_T > 4 + case 8: pos= (my_off_t) mi_uint8korr(after_key); break; + case 7: pos= (my_off_t) mi_uint7korr(after_key); break; + case 6: pos= (my_off_t) mi_uint6korr(after_key); break; + case 5: pos= (my_off_t) mi_uint5korr(after_key); break; +#else + case 8: pos= (my_off_t) mi_uint4korr(after_key+4); break; + case 7: pos= (my_off_t) mi_uint4korr(after_key+3); break; + case 6: pos= (my_off_t) mi_uint4korr(after_key+2); break; + case 5: pos= (my_off_t) mi_uint4korr(after_key+1); break; +#endif + case 4: pos= (my_off_t) mi_uint4korr(after_key); break; + case 3: pos= (my_off_t) mi_uint3korr(after_key); break; + case 2: pos= (my_off_t) mi_uint2korr(after_key); break; + default: + pos=0L; /* Shut compiler up */ + } + return (info->s->options & + (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) ? pos : + pos*info->s->base.pack_reclength; +} + + +/* Calc position from a record pointer ( in delete link chain ) */ + +my_off_t _mi_rec_pos(MYISAM_SHARE *s, uchar *ptr) +{ + my_off_t pos; + switch (s->rec_reflength) { +#if SIZEOF_OFF_T > 4 + case 8: + pos= (my_off_t) mi_uint8korr(ptr); + if (pos == HA_OFFSET_ERROR) + return HA_OFFSET_ERROR; /* end of list */ + break; + case 7: + pos= (my_off_t) mi_uint7korr(ptr); + if (pos == (((my_off_t) 1) << 56) -1) + return HA_OFFSET_ERROR; /* end of list */ + break; + case 6: + pos= (my_off_t) mi_uint6korr(ptr); + if (pos == (((my_off_t) 1) << 48) -1) + return HA_OFFSET_ERROR; /* end of list */ + break; + case 5: + pos= (my_off_t) mi_uint5korr(ptr); + if (pos == (((my_off_t) 1) << 40) -1) + return HA_OFFSET_ERROR; /* end of list */ + break; +#else + case 8: + case 7: + case 6: + case 5: + ptr+= (s->rec_reflength-4); + /* fall through */ +#endif + case 4: + pos= (my_off_t) mi_uint4korr(ptr); + if (pos == (my_off_t) (uint32) ~0L) + return HA_OFFSET_ERROR; + break; + case 3: + pos= (my_off_t) mi_uint3korr(ptr); + if (pos == (my_off_t) (1 << 24) -1) + return HA_OFFSET_ERROR; + break; + case 2: + pos= (my_off_t) mi_uint2korr(ptr); + if (pos == (my_off_t) (1 << 16) -1) + return HA_OFFSET_ERROR; + break; + default: abort(); /* Impossible */ + } + return ((s->options & + (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) ? pos : + pos*s->base.pack_reclength); +} + + + /* save position to record */ + +void _mi_dpointer(MI_INFO *info, uchar *buff, my_off_t pos) +{ + if (!(info->s->options & + (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) && + pos != HA_OFFSET_ERROR) + pos/=info->s->base.pack_reclength; + + switch (info->s->rec_reflength) { +#if SIZEOF_OFF_T > 4 + case 8: mi_int8store(buff,pos); break; + case 7: mi_int7store(buff,pos); break; + case 6: mi_int6store(buff,pos); break; + case 5: mi_int5store(buff,pos); break; +#else + case 8: *buff++=0; + /* fall through */ + case 7: *buff++=0; + /* fall through */ + case 6: *buff++=0; + /* fall through */ + case 5: *buff++=0; + /* fall through */ +#endif + case 4: mi_int4store(buff,pos); break; + case 3: mi_int3store(buff,pos); break; + case 2: mi_int2store(buff,(uint) pos); break; + default: abort(); /* Impossible */ + } +} /* _mi_dpointer */ + + + /* 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 */ + + /* same as _mi_get_key but used with fixed length keys */ + +uint _mi_get_static_key(register MI_KEYDEF *keyinfo, uint nod_flag, + register uchar **page, register uchar *key) +{ + memcpy((uchar*) key,(uchar*) *page, + (size_t) (keyinfo->keylength+nod_flag)); + *page+=keyinfo->keylength+nod_flag; + return(keyinfo->keylength); +} /* _mi_get_static_key */ + + +/* + get key witch is packed against previous key or key with a NULL column. + + SYNOPSIS + _mi_get_pack_key() + keyinfo key definition information. + nod_flag If nod: Length of node pointer, else zero. + page_pos RETURN position in key page behind this key. + key IN/OUT in: prev key, out: unpacked key. + + RETURN + key_length + length of data pointer +*/ + +uint _mi_get_pack_key(register MI_KEYDEF *keyinfo, uint nod_flag, + register uchar **page_pos, register uchar *key) +{ + reg1 HA_KEYSEG *keyseg; + uchar *start_key,*page=*page_pos; + uint length; + + start_key=key; + for (keyseg=keyinfo->seg ; keyseg->type ;keyseg++) + { + if (keyseg->flag & HA_PACK_KEY) + { + /* key with length, packed to previous key */ + uchar *start=key; + uint packed= *page & 128,tot_length,rest_length; + if (keyseg->length >= 127) + { + length=mi_uint2korr(page) & 32767; + page+=2; + } + else + length= *page++ & 127; + + if (packed) + { + if (length > (uint) keyseg->length) + { + mi_print_error(keyinfo->share, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + return 0; /* Error */ + } + if (length == 0) /* Same key */ + { + if (keyseg->flag & HA_NULL_PART) + *key++=1; /* Can't be NULL */ + get_key_length(length,key); + key+= length; /* Same diff_key as prev */ + if (length > keyseg->length) + { + DBUG_PRINT("error", + ("Found too long null packed key: %u of %u at %p", + length, keyseg->length, *page_pos)); + DBUG_DUMP("key", *page_pos, 16); + mi_print_error(keyinfo->share, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + return 0; + } + continue; + } + if (keyseg->flag & HA_NULL_PART) + { + key++; /* Skip null marker*/ + start++; + } + + get_key_length(rest_length,page); + tot_length=rest_length+length; + + /* If the stored length has changed, we must move the key */ + if (tot_length >= 255 && *start != 255) + { + /* length prefix changed from a length of one to a length of 3 */ + bmove_upp(key+length+3, key+length+1, length); + *key=255; + mi_int2store(key+1,tot_length); + key+=3+length; + } + else if (tot_length < 255 && *start == 255) + { + bmove(key+1,key+3,length); + *key=tot_length; + key+=1+length; + } + else + { + store_key_length_inc(key,tot_length); + key+=length; + } + memcpy(key,page,rest_length); + page+=rest_length; + key+=rest_length; + continue; + } + else + { + if (keyseg->flag & HA_NULL_PART) + { + if (!length--) /* Null part */ + { + *key++=0; + continue; + } + *key++=1; /* Not null */ + } + } + if (length > (uint) keyseg->length) + { + DBUG_PRINT("error",("Found too long packed key: %u of %u at %p", + length, keyseg->length, *page_pos)); + DBUG_DUMP("key", *page_pos, 16); + mi_print_error(keyinfo->share, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + return 0; /* Error */ + } + store_key_length_inc(key,length); + } + else + { + if (keyseg->flag & HA_NULL_PART) + { + if (!(*key++ = *page++)) + continue; + } + if (keyseg->flag & + (HA_VAR_LENGTH_PART | HA_BLOB_PART | HA_SPACE_PACK)) + { + uchar *tmp=page; + get_key_length(length,tmp); + length+=(uint) (tmp-page); + } + else + length=keyseg->length; + } + memcpy((uchar*) key,(uchar*) page,(size_t) length); + key+=length; + page+=length; + } + length=keyseg->length+nod_flag; + bmove((uchar*) key,(uchar*) page,length); + *page_pos= page+length; + return ((uint) (key-start_key)+keyseg->length); +} /* _mi_get_pack_key */ + + + +/* key that is packed relatively to previous */ + +uint _mi_get_binary_pack_key(register MI_KEYDEF *keyinfo, uint nod_flag, + register uchar **page_pos, register uchar *key) +{ + reg1 HA_KEYSEG *keyseg; + uchar *start_key,*page,*page_end,*from,*from_end; + uint length,tmp; + DBUG_ENTER("_mi_get_binary_pack_key"); + + page= *page_pos; + page_end=page+HA_MAX_KEY_BUFF+1; + start_key=key; + + /* + Keys are compressed the following way: + + prefix length Packed length of prefix common with prev key (1 or 3 bytes) + for each key segment: + [is null] Null indicator if can be null (1 byte, zero means null) + [length] Packed length if varlength (1 or 3 bytes) + key segment 'length' bytes of key segment value + pointer Reference to the data file (last_keyseg->length). + + get_key_length() is a macro. It gets the prefix length from 'page' + and puts it into 'length'. It increments 'page' by 1 or 3, depending + on the packed length of the prefix length. + */ + get_key_length(length,page); + if (length) + { + if (length > keyinfo->maxlength) + { + DBUG_PRINT("error", + ("Found too long binary packed key: %u of %u at %p", + length, keyinfo->maxlength, *page_pos)); + DBUG_DUMP("key", *page_pos, 16); + goto crashed; /* Wrong key */ + } + /* Key is packed against prev key, take prefix from prev key. */ + from= key; + from_end= key + length; + } + else + { + /* Key is not packed against prev key, take all from page buffer. */ + from= page; + from_end= page_end; + } + + /* + The trouble is that key can be split in two parts: + The first part (prefix) is in from .. from_end - 1. + The second part starts at page. + The split can be at every byte position. So we need to check for + the end of the first part before using every byte. + */ + for (keyseg=keyinfo->seg ; keyseg->type ;keyseg++) + { + if (keyseg->flag & HA_NULL_PART) + { + /* If prefix is used up, switch to rest. */ + if (from == from_end) { from=page; from_end=page_end; } + if (!(*key++ = *from++)) + continue; /* Null part */ + } + if (keyseg->flag & (HA_VAR_LENGTH_PART | HA_BLOB_PART | HA_SPACE_PACK)) + { + /* If prefix is used up, switch to rest. */ + if (from == from_end) { from=page; from_end=page_end; } + /* Get length of dynamic length key part */ + if ((length= (*key++ = *from++)) == 255) + { + /* If prefix is used up, switch to rest. */ + if (from == from_end) { from=page; from_end=page_end; } + length= (uint) ((*key++ = *from++)) << 8; + /* If prefix is used up, switch to rest. */ + if (from == from_end) { from=page; from_end=page_end; } + length+= (uint) ((*key++ = *from++)); + } + if (length > keyseg->length) + goto crashed; + } + else + length=keyseg->length; + + if ((tmp=(uint) (from_end-from)) <= length) + { + key+=tmp; /* Use old key */ + length-=tmp; + from=page; from_end=page_end; + } + DBUG_PRINT("info",("key: %p from: %p length: %u", + key, from, length)); + memmove((uchar*) key, (uchar*) from, (size_t) length); + key+=length; + from+=length; + } + /* + Last segment (type == 0) contains length of data pointer. + If we have mixed key blocks with data pointer and key block pointer, + we have to copy both. + */ + length=keyseg->length+nod_flag; + if ((tmp=(uint) (from_end-from)) <= length) + { + /* Remaining length is less or equal max possible length. */ + memcpy(key+tmp,page,length-tmp); /* Get last part of key */ + *page_pos= page+length-tmp; + } + else + { + /* + Remaining length is greater than max possible length. + This can happen only if we switched to the new key bytes already. + 'page_end' is calculated with MI_MAX_KEY_BUFF. So it can be far + behind the real end of the key. + */ + if (from_end != page_end) + { + DBUG_PRINT("error",("Error when unpacking key")); + goto crashed; /* Error */ + } + /* Copy data pointer and, if appropriate, key block pointer. */ + memcpy((uchar*) key,(uchar*) from,(size_t) length); + *page_pos= from+length; + } + DBUG_RETURN((uint) (key-start_key)+keyseg->length); + + crashed: + mi_print_error(keyinfo->share, HA_ERR_CRASHED); + my_errno= HA_ERR_CRASHED; + DBUG_RETURN(0); +} + + + /* Get key at position without knowledge of previous key */ + /* Returns pointer to next key */ + +uchar *_mi_get_key(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uchar *keypos, uint *return_key_length) +{ + uint nod_flag; + DBUG_ENTER("_mi_get_key"); + + nod_flag=mi_test_if_nod(page); + if (! (keyinfo->flag & (HA_VAR_LENGTH_KEY | HA_BINARY_PACK_KEY))) + { + bmove((uchar*) key,(uchar*) keypos,keyinfo->keylength+nod_flag); + DBUG_RETURN(keypos+keyinfo->keylength+nod_flag); + } + else + { + page+=2+nod_flag; + key[0]=0; /* safety */ + while (page <= keypos) + { + *return_key_length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,key); + if (*return_key_length == 0) + { + mi_print_error(info->s, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + DBUG_RETURN(0); + } + } + } + DBUG_PRINT("exit",("page: %p length: %u", page, + *return_key_length)); + DBUG_RETURN(page); +} /* _mi_get_key */ + + + /* Get key at position without knowledge of previous key */ + /* Returns 0 if ok */ + +static my_bool _mi_get_prev_key(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, + uchar *key, uchar *keypos, + uint *return_key_length) +{ + uint nod_flag; + DBUG_ENTER("_mi_get_prev_key"); + + nod_flag=mi_test_if_nod(page); + if (! (keyinfo->flag & (HA_VAR_LENGTH_KEY | HA_BINARY_PACK_KEY))) + { + *return_key_length=keyinfo->keylength; + bmove((uchar*) key,(uchar*) keypos- *return_key_length-nod_flag, + *return_key_length); + DBUG_RETURN(0); + } + else + { + page+=2+nod_flag; + key[0]=0; /* safety */ + while (page < keypos) + { + *return_key_length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,key); + if (*return_key_length == 0) + { + mi_print_error(info->s, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + DBUG_RETURN(1); + } + } + } + DBUG_RETURN(0); +} /* _mi_get_key */ + + + + /* Get last key from key-page */ + /* Return pointer to where key starts */ + +uchar *_mi_get_last_key(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, + uchar *lastkey, uchar *endpos, uint *return_key_length) +{ + uint nod_flag; + uchar *lastpos; + DBUG_ENTER("_mi_get_last_key"); + DBUG_PRINT("enter",("page:%p endpos: %p", page, + endpos)); + + nod_flag=mi_test_if_nod(page); + if (! (keyinfo->flag & (HA_VAR_LENGTH_KEY | HA_BINARY_PACK_KEY))) + { + lastpos=endpos-keyinfo->keylength-nod_flag; + *return_key_length=keyinfo->keylength; + if (lastpos > page) + bmove((uchar*) lastkey,(uchar*) lastpos,keyinfo->keylength+nod_flag); + } + else + { + lastpos=(page+=2+nod_flag); + lastkey[0]=0; + while (page < endpos) + { + lastpos=page; + *return_key_length=(*keyinfo->get_key)(keyinfo,nod_flag,&page,lastkey); + if (*return_key_length == 0) + { + DBUG_PRINT("error",("Couldn't find last key: page: %p", + page)); + mi_print_error(info->s, HA_ERR_CRASHED); + my_errno=HA_ERR_CRASHED; + DBUG_RETURN(0); + } + } + } + DBUG_PRINT("exit",("lastpos: %p length: %u", lastpos, + *return_key_length)); + DBUG_RETURN(lastpos); +} /* _mi_get_last_key */ + + + /* Calculate length of key */ + +uint _mi_keylength(MI_KEYDEF *keyinfo, register uchar *key) +{ + reg1 HA_KEYSEG *keyseg; + uchar *start; + + if (! (keyinfo->flag & (HA_VAR_LENGTH_KEY | HA_BINARY_PACK_KEY))) + return (keyinfo->keylength); + + start=key; + for (keyseg=keyinfo->seg ; keyseg->type ; keyseg++) + { + if (keyseg->flag & HA_NULL_PART) + if (!*key++) + continue; + if (keyseg->flag & (HA_SPACE_PACK | HA_BLOB_PART | HA_VAR_LENGTH_PART)) + { + uint length; + get_key_length(length,key); + key+=length; + } + else + key+= keyseg->length; + } + return((uint) (key-start)+keyseg->length); +} /* _mi_keylength */ + + +/* + Calculate length of part key. + + Used in mi_rkey() to find the key found for the key-part that was used. + This is needed in case of multi-byte character sets where we may search + after '0xDF' but find 'ss' +*/ + +uint _mi_keylength_part(MI_KEYDEF *keyinfo, register uchar *key, + HA_KEYSEG *end) +{ + reg1 HA_KEYSEG *keyseg; + uchar *start= key; + + for (keyseg=keyinfo->seg ; keyseg != end ; keyseg++) + { + if (keyseg->flag & HA_NULL_PART) + if (!*key++) + continue; + if (keyseg->flag & (HA_SPACE_PACK | HA_BLOB_PART | HA_VAR_LENGTH_PART)) + { + uint length; + get_key_length(length,key); + key+=length; + } + else + key+= keyseg->length; + } + return (uint) (key-start); +} + + /* Move a key */ + +uchar *_mi_move_key(MI_KEYDEF *keyinfo, uchar *to, uchar *from) +{ + reg1 uint length; + memcpy((uchar*) to, (uchar*) from, + (size_t) (length=_mi_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 _mi_search_next(register MI_INFO *info, register MI_KEYDEF *keyinfo, + uchar *key, uint key_length, uint nextflag, my_off_t pos) +{ + int error; + uint nod_flag; + uchar lastkey[HA_MAX_KEY_BUFF]; + DBUG_ENTER("_mi_search_next"); + DBUG_PRINT("enter",("nextflag: %u lastpos: %llu int_keypos: %p", + nextflag, info->lastpos, + info->int_keypos)); + DBUG_EXECUTE("key",_mi_print_key(DBUG_FILE,keyinfo->seg,key,key_length);); + + /* Force full read if we are at last key or if we are not on a leaf + and the key tree has changed since we used it last time + Note that even if the key tree has changed since last read, we can use + the last read data from the leaf if we haven't used the buffer for + something else. + */ + + if (((nextflag & SEARCH_BIGGER) && info->int_keypos >= info->int_maxpos) || + info->page_changed || + (info->int_keytree_version != keyinfo->version && + (info->int_nod_flag || info->buff_used))) + DBUG_RETURN(_mi_search(info,keyinfo,key, USE_WHOLE_KEY, + nextflag | SEARCH_SAVE_BUFF, pos)); + + if (info->buff_used) + { + if (!_mi_fetch_keypage(info,keyinfo,info->last_search_keypage, + DFLT_INIT_HITS,info->buff,0)) + DBUG_RETURN(-1); + info->buff_used=0; + } + + /* Last used buffer is in info->buff */ + nod_flag=mi_test_if_nod(info->buff); + + if (nextflag & SEARCH_BIGGER) /* Next key */ + { + my_off_t tmp_pos=_mi_kpos(nod_flag,info->int_keypos); + if (tmp_pos != HA_OFFSET_ERROR) + { + if ((error=_mi_search(info,keyinfo,key, USE_WHOLE_KEY, + nextflag | SEARCH_SAVE_BUFF, tmp_pos)) <=0) + DBUG_RETURN(error); + } + memcpy(lastkey,key,key_length); + if (!(info->lastkey_length=(*keyinfo->get_key)(keyinfo,nod_flag, + &info->int_keypos,lastkey))) + DBUG_RETURN(-1); + } + else /* Previous key */ + { + uint length; + /* Find start of previous key */ + info->int_keypos=_mi_get_last_key(info,keyinfo,info->buff,lastkey, + info->int_keypos, &length); + if (!info->int_keypos) + DBUG_RETURN(-1); + if (info->int_keypos == info->buff+2) + DBUG_RETURN(_mi_search(info,keyinfo,key, USE_WHOLE_KEY, + nextflag | SEARCH_SAVE_BUFF, pos)); + if ((error=_mi_search(info,keyinfo,key, USE_WHOLE_KEY, + nextflag | SEARCH_SAVE_BUFF, + _mi_kpos(nod_flag,info->int_keypos))) <= 0) + DBUG_RETURN(error); + + /* QQ: We should be able to optimize away the following call */ + if (! _mi_get_last_key(info,keyinfo,info->buff,lastkey, + info->int_keypos,&info->lastkey_length)) + DBUG_RETURN(-1); + } + memcpy(info->lastkey,lastkey,info->lastkey_length); + info->lastpos=_mi_dpos(info,0,info->lastkey+info->lastkey_length); + DBUG_PRINT("exit",("found key at %lu",(ulong) info->lastpos)); + DBUG_RETURN(0); +} /* _mi_search_next */ + + + /* Search after position for the first row in an index */ + /* This is stored in info->lastpos */ + +int _mi_search_first(register MI_INFO *info, register MI_KEYDEF *keyinfo, + register my_off_t pos) +{ + uint nod_flag; + uchar *page; + DBUG_ENTER("_mi_search_first"); + + if (pos == HA_OFFSET_ERROR) + { + my_errno=HA_ERR_KEY_NOT_FOUND; + info->lastpos= HA_OFFSET_ERROR; + DBUG_RETURN(-1); + } + + do + { + if (!_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff,0)) + { + info->lastpos= HA_OFFSET_ERROR; + DBUG_RETURN(-1); + } + nod_flag=mi_test_if_nod(info->buff); + page=info->buff+2+nod_flag; + } while ((pos=_mi_kpos(nod_flag,page)) != HA_OFFSET_ERROR); + + if (!(info->lastkey_length=(*keyinfo->get_key)(keyinfo,nod_flag,&page, + info->lastkey))) + DBUG_RETURN(-1); /* Crashed */ + + info->int_keypos=page; info->int_maxpos=info->buff+mi_getint(info->buff)-1; + info->int_nod_flag=nod_flag; + info->int_keytree_version=keyinfo->version; + info->last_search_keypage=info->last_keypage; + info->page_changed=info->buff_used=0; + info->lastpos=_mi_dpos(info,0,info->lastkey+info->lastkey_length); + + DBUG_PRINT("exit",("found key at %lu", (ulong) info->lastpos)); + DBUG_RETURN(0); +} /* _mi_search_first */ + + + /* Search after position for the last row in an index */ + /* This is stored in info->lastpos */ + +int _mi_search_last(register MI_INFO *info, register MI_KEYDEF *keyinfo, + register my_off_t pos) +{ + uint nod_flag; + uchar *buff,*page; + DBUG_ENTER("_mi_search_last"); + + if (pos == HA_OFFSET_ERROR) + { + my_errno=HA_ERR_KEY_NOT_FOUND; /* Didn't find key */ + info->lastpos= HA_OFFSET_ERROR; + DBUG_RETURN(-1); + } + + buff=info->buff; + do + { + if (!_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,buff,0)) + { + info->lastpos= HA_OFFSET_ERROR; + DBUG_RETURN(-1); + } + page= buff+mi_getint(buff); + nod_flag=mi_test_if_nod(buff); + } while ((pos=_mi_kpos(nod_flag,page)) != HA_OFFSET_ERROR); + + if (!_mi_get_last_key(info,keyinfo,buff,info->lastkey,page, + &info->lastkey_length)) + DBUG_RETURN(-1); + info->lastpos=_mi_dpos(info,0,info->lastkey+info->lastkey_length); + info->int_keypos=info->int_maxpos=page; + info->int_nod_flag=nod_flag; + info->int_keytree_version=keyinfo->version; + info->last_search_keypage=info->last_keypage; + info->page_changed=info->buff_used=0; + + DBUG_PRINT("exit",("found key at %lu",(ulong) info->lastpos)); + DBUG_RETURN(0); +} /* _mi_search_last */ + + + +/**************************************************************************** +** +** Functions to store and pack a key in a page +** +** mi_calc_xx_key_length takes the following arguments: +** nod_flag If nod: Length of nod-pointer +** next_key Position to pos after the new key in buffer +** org_key Key that was before the next key in buffer +** prev_key Last key before current key +** key Key that will be stored +** s_temp Information how next key will be packed +****************************************************************************/ + +/* Static length key */ + +int +_mi_calc_static_key_length(MI_KEYDEF *keyinfo,uint nod_flag, + uchar *next_pos __attribute__((unused)), + uchar *org_key __attribute__((unused)), + uchar *prev_key __attribute__((unused)), + uchar *key, MI_KEY_PARAM *s_temp) +{ + s_temp->key=key; + return (int) (s_temp->totlength=keyinfo->keylength+nod_flag); +} + +/* Variable length key */ + +int +_mi_calc_var_key_length(MI_KEYDEF *keyinfo,uint nod_flag, + uchar *next_pos __attribute__((unused)), + uchar *org_key __attribute__((unused)), + uchar *prev_key __attribute__((unused)), + uchar *key, MI_KEY_PARAM *s_temp) +{ + s_temp->key=key; + return (int) (s_temp->totlength=_mi_keylength(keyinfo,key)+nod_flag); +} + +/* + length of key with a variable length first segment which is prefix + compressed (myisamchk reports 'packed + stripped') + + Keys are compressed the following way: + + If the max length of first key segment <= 127 bytes the prefix is + 1 byte else it's 2 byte + + prefix byte(s) The high bit is set if this is a prefix for the prev key + length Packed length if the previous was a prefix byte + [length] data bytes ('length' bytes) + next-key-seg Next key segments + + If the first segment can have NULL: + The length is 0 for NULLS and 1+length for not null columns. + +*/ + +int +_mi_calc_var_pack_key_length(MI_KEYDEF *keyinfo,uint nod_flag,uchar *next_key, + uchar *org_key, uchar *prev_key, uchar *key, + MI_KEY_PARAM *s_temp) +{ + reg1 HA_KEYSEG *keyseg; + int length; + uint key_length,ref_length,org_key_length=0, + length_pack,new_key_length,diff_flag,pack_marker; + uchar *start,*end,*key_end; + const uchar *sort_order; + my_bool same_length; + + length_pack=s_temp->ref_length=s_temp->n_ref_length=s_temp->n_length=0; + same_length=0; keyseg=keyinfo->seg; + key_length=_mi_keylength(keyinfo,key)+nod_flag; + + sort_order=0; + if ((keyinfo->flag & HA_FULLTEXT) && + ((keyseg->type == HA_KEYTYPE_TEXT) || + (keyseg->type == HA_KEYTYPE_VARTEXT1) || + (keyseg->type == HA_KEYTYPE_VARTEXT2)) && + !use_strnxfrm(keyseg->charset)) + sort_order=keyseg->charset->sort_order; + + /* diff flag contains how many bytes is needed to pack key */ + if (keyseg->length >= 127) + { + diff_flag=2; + pack_marker=32768; + } + else + { + diff_flag= 1; + pack_marker=128; + } + s_temp->pack_marker=pack_marker; + + /* Handle the case that the first part have NULL values */ + if (keyseg->flag & HA_NULL_PART) + { + if (!*key++) + { + s_temp->key=key; + s_temp->key_length= 0; + s_temp->totlength=key_length-1+diff_flag; + s_temp->next_key_pos=0; /* No next key */ + return (s_temp->totlength); + } + s_temp->store_not_null=1; + key_length--; /* We don't store NULL */ + if (prev_key && !*prev_key++) + org_key=prev_key=0; /* Can't pack against prev */ + else if (org_key) + org_key++; /* Skip NULL */ + } + else + s_temp->store_not_null=0; + s_temp->prev_key=org_key; + + /* The key part will start with a packed length */ + + get_key_pack_length(new_key_length,length_pack,key); + end=key_end= key+ new_key_length; + start=key; + + /* Calc how many characters are identical between this and the prev. key */ + if (prev_key) + { + get_key_length(org_key_length,prev_key); + s_temp->prev_key=prev_key; /* Pointer at data */ + /* Don't use key-pack if length == 0 */ + if (new_key_length && new_key_length == org_key_length) + same_length=1; + else if (new_key_length > org_key_length) + end=key + org_key_length; + + if (sort_order) /* SerG */ + { + while (key < end && sort_order[*key] == sort_order[*prev_key]) + { + key++; prev_key++; + } + } + else + { + while (key < end && *key == *prev_key) + { + key++; prev_key++; + } + } + } + + s_temp->key=key; + s_temp->key_length= (uint) (key_end-key); + + if (same_length && key == key_end) + { + /* identical variable length key */ + s_temp->ref_length= pack_marker; + length=(int) key_length-(int) (key_end-start)-length_pack; + length+= diff_flag; + if (next_key) + { /* Can't combine with next */ + s_temp->n_length= *next_key; /* Needed by _mi_store_key */ + next_key=0; + } + } + else + { + if (start != key) + { /* Starts as prev key */ + ref_length= (uint) (key-start); + s_temp->ref_length= ref_length + pack_marker; + length= (int) (key_length - ref_length); + + length-= length_pack; + length+= diff_flag; + length+= ((new_key_length-ref_length) >= 255) ? 3 : 1;/* Rest_of_key */ + } + else + { + s_temp->key_length+=s_temp->store_not_null; /* If null */ + length= key_length - length_pack+ diff_flag; + } + } + s_temp->totlength=(uint) length; + s_temp->prev_length=0; + DBUG_PRINT("test",("tot_length: %u length: %d uniq_key_length: %u", + key_length, length, s_temp->key_length)); + + /* If something after that hasn't length=0, test if we can combine */ + if ((s_temp->next_key_pos=next_key)) + { + uint packed,n_length; + + packed = *next_key & 128; + if (diff_flag == 2) + { + n_length= mi_uint2korr(next_key) & 32767; /* Length of next key */ + next_key+=2; + } + else + n_length= *next_key++ & 127; + if (!packed) + n_length-= s_temp->store_not_null; + + if (n_length || packed) /* Don't pack 0 length keys */ + { + uint next_length_pack, new_ref_length=s_temp->ref_length; + + if (packed) + { + /* If first key and next key is packed (only on delete) */ + if (!prev_key && org_key) + { + get_key_length(org_key_length,org_key); + key=start; + if (sort_order) /* SerG */ + { + while (key < end && sort_order[*key] == sort_order[*org_key]) + { + key++; org_key++; + } + } + else + { + while (key < end && *key == *org_key) + { + key++; org_key++; + } + } + if ((new_ref_length= (uint) (key - start))) + new_ref_length+=pack_marker; + } + + if (!n_length) + { + /* + We put a different key between two identical variable length keys + Extend next key to have same prefix as this key + */ + if (new_ref_length) /* prefix of previus key */ + { /* make next key longer */ + s_temp->part_of_prev_key= new_ref_length; + s_temp->prev_length= org_key_length - + (new_ref_length-pack_marker); + s_temp->n_ref_length= s_temp->part_of_prev_key; + s_temp->n_length= s_temp->prev_length; + n_length= get_pack_length(s_temp->prev_length); + s_temp->prev_key+= (new_ref_length - pack_marker); + length+= s_temp->prev_length + n_length; + } + else + { /* Can't use prev key */ + s_temp->part_of_prev_key=0; + s_temp->prev_length= org_key_length; + s_temp->n_ref_length=s_temp->n_length= org_key_length; + length+= org_key_length; + } + return (int) length; + } + + ref_length=n_length; + /* Get information about not packed key suffix */ + get_key_pack_length(n_length,next_length_pack,next_key); + + /* Test if new keys has fewer characters that match the previous key */ + if (!new_ref_length) + { /* Can't use prev key */ + s_temp->part_of_prev_key= 0; + s_temp->prev_length= ref_length; + s_temp->n_ref_length= s_temp->n_length= n_length+ref_length; + return (int) length+ref_length-next_length_pack; + } + if (ref_length+pack_marker > new_ref_length) + { + uint new_pack_length=new_ref_length-pack_marker; + /* We must copy characters from the original key to the next key */ + s_temp->part_of_prev_key= new_ref_length; + s_temp->prev_length= ref_length - new_pack_length; + s_temp->n_ref_length=s_temp->n_length=n_length + s_temp->prev_length; + s_temp->prev_key+= new_pack_length; + length-= (next_length_pack - get_pack_length(s_temp->n_length)); + return (int) length + s_temp->prev_length; + } + } + else + { + /* Next key wasn't a prefix of previous key */ + ref_length=0; + next_length_pack=0; + } + DBUG_PRINT("test",("length: %d next_key: %p", length, + next_key)); + + { + uint tmp_length; + key=(start+=ref_length); + if (key+n_length < key_end) /* Normalize length based */ + key_end=key+n_length; + if (sort_order) /* SerG */ + { + while (key < key_end && sort_order[*key] == + sort_order[*next_key]) + { + key++; next_key++; + } + } + else + { + while (key < key_end && *key == *next_key) + { + key++; next_key++; + } + } + if (!(tmp_length=(uint) (key-start))) + { /* Key can't be re-packed */ + s_temp->next_key_pos=0; + return length; + } + ref_length+=tmp_length; + n_length-=tmp_length; + length-=tmp_length+next_length_pack; /* We gained these chars */ + } + if (n_length == 0 && ref_length == new_key_length) + { + s_temp->n_ref_length=pack_marker; /* Same as prev key */ + } + else + { + s_temp->n_ref_length=ref_length | pack_marker; + length+= get_pack_length(n_length); + s_temp->n_length=n_length; + } + } + } + return length; +} + + +/* Length of key which is prefix compressed */ + +int +_mi_calc_bin_pack_key_length(MI_KEYDEF *keyinfo,uint nod_flag,uchar *next_key, + uchar *org_key, uchar *prev_key, uchar *key, + MI_KEY_PARAM *s_temp) +{ + uint length,key_length,ref_length; + + s_temp->totlength=key_length=_mi_keylength(keyinfo,key)+nod_flag; +#ifdef HAVE_valgrind + s_temp->n_length= s_temp->n_ref_length=0; /* For valgrind */ +#endif + s_temp->key=key; + s_temp->prev_key=org_key; + if (prev_key) /* If not first key in block */ + { + /* pack key against previous key */ + /* + As keys may be identical when running a sort in myisamchk, we + have to guard against the case where keys may be identical + */ + uchar *end; + end=key+key_length; + for ( ; *key == *prev_key && key < end; key++,prev_key++) ; + s_temp->ref_length= ref_length=(uint) (key-s_temp->key); + length=key_length - ref_length + get_pack_length(ref_length); + } + else + { + /* No previous key */ + s_temp->ref_length=ref_length=0; + length=key_length+1; + } + if ((s_temp->next_key_pos=next_key)) /* If another key after */ + { + /* pack key against next key */ + uint next_length,next_length_pack; + get_key_pack_length(next_length,next_length_pack,next_key); + + /* If first key and next key is packed (only on delete) */ + if (!prev_key && org_key && next_length) + { + uchar *end; + for (key= s_temp->key, end=key+next_length ; + *key == *org_key && key < end; + key++,org_key++) ; + ref_length= (uint) (key - s_temp->key); + } + + if (next_length > ref_length) + { + /* We put a key with different case between two keys with the same prefix + Extend next key to have same prefix as + this key */ + s_temp->n_ref_length= ref_length; + s_temp->prev_length= next_length-ref_length; + s_temp->prev_key+= ref_length; + return (int) (length+ s_temp->prev_length - next_length_pack + + get_pack_length(ref_length)); + } + /* Check how many characters are identical to next key */ + key= s_temp->key+next_length; + s_temp->prev_length= 0; + while (*key++ == *next_key++) ; + if ((ref_length= (uint) (key - s_temp->key)-1) == next_length) + { + s_temp->next_key_pos=0; + return length; /* can't pack next key */ + } + s_temp->n_ref_length=ref_length; + return (int) (length-(ref_length - next_length) - next_length_pack + + get_pack_length(ref_length)); + } + return (int) length; +} + + +/* +** store a key packed with _mi_calc_xxx_key_length in page-buffert +*/ + +/* store key without compression */ + +void _mi_store_static_key(MI_KEYDEF *keyinfo __attribute__((unused)), + register uchar *key_pos, + register MI_KEY_PARAM *s_temp) +{ + memcpy((uchar*) key_pos,(uchar*) s_temp->key,(size_t) s_temp->totlength); +} + + +/* store variable length key with prefix compression */ + +#define store_pack_length(test,pos,length) { \ + if (test) { *((pos)++) = (uchar) (length); } else \ + { *((pos)++) = (uchar) ((length) >> 8); *((pos)++) = (uchar) (length); } } + + +void _mi_store_var_pack_key(MI_KEYDEF *keyinfo __attribute__((unused)), + register uchar *key_pos, + register MI_KEY_PARAM *s_temp) +{ + uint length; + uchar *start; + + start=key_pos; + + if (s_temp->ref_length) + { + /* Packed against previous key */ + store_pack_length(s_temp->pack_marker == 128,key_pos,s_temp->ref_length); + /* If not same key after */ + if (s_temp->ref_length != s_temp->pack_marker) + store_key_length_inc(key_pos,s_temp->key_length); + } + else + { + /* Not packed against previous key */ + store_pack_length(s_temp->pack_marker == 128,key_pos,s_temp->key_length); + } + bmove((uchar*) key_pos,(uchar*) s_temp->key, + (length=s_temp->totlength-(uint) (key_pos-start))); + + if (!s_temp->next_key_pos) /* No following key */ + return; + key_pos+=length; + + if (s_temp->prev_length) + { + /* Extend next key because new key didn't have same prefix as prev key */ + if (s_temp->part_of_prev_key) + { + store_pack_length(s_temp->pack_marker == 128,key_pos, + s_temp->part_of_prev_key); + store_key_length_inc(key_pos,s_temp->n_length); + } + else + { + s_temp->n_length+= s_temp->store_not_null; + store_pack_length(s_temp->pack_marker == 128,key_pos, + s_temp->n_length); + } + memcpy(key_pos, s_temp->prev_key, s_temp->prev_length); + } + else if (s_temp->n_ref_length) + { + store_pack_length(s_temp->pack_marker == 128,key_pos,s_temp->n_ref_length); + if (s_temp->n_ref_length == s_temp->pack_marker) + return; /* Identical key */ + store_key_length(key_pos,s_temp->n_length); + } + else + { + s_temp->n_length+= s_temp->store_not_null; + store_pack_length(s_temp->pack_marker == 128,key_pos,s_temp->n_length); + } +} + + +/* variable length key with prefix compression */ + +void _mi_store_bin_pack_key(MI_KEYDEF *keyinfo __attribute__((unused)), + register uchar *key_pos, + register MI_KEY_PARAM *s_temp) +{ + store_key_length_inc(key_pos,s_temp->ref_length); + memcpy((char*) key_pos,(char*) s_temp->key+s_temp->ref_length, + (size_t) s_temp->totlength-s_temp->ref_length); + + if (s_temp->next_key_pos) + { + key_pos+=(uint) (s_temp->totlength-s_temp->ref_length); + store_key_length_inc(key_pos,s_temp->n_ref_length); + if (s_temp->prev_length) /* If we must extend key */ + { + memcpy(key_pos,s_temp->prev_key,s_temp->prev_length); + } + } +} |