diff options
Diffstat (limited to 'isam/_key.c')
| -rw-r--r-- | isam/_key.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/isam/_key.c b/isam/_key.c new file mode 100644 index 00000000000..62f080af172 --- /dev/null +++ b/isam/_key.c @@ -0,0 +1,239 @@ +/* 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 */ + +/* Functions to handle keys */ + +#include "isamdef.h" +#include "m_ctype.h" + +static void _nisam_put_key_in_record(N_INFO *info,uint keynr,byte *record); + + /* Make a intern key from a record */ + /* If ascii key convert according to sortorder */ + /* Ret: Length of key */ + +uint _nisam_make_key(register N_INFO *info, uint keynr, uchar *key, const char *record, ulong filepos) +{ + uint length; + byte *pos,*end; + uchar *start; + reg1 N_KEYSEG *keyseg; + enum ha_base_keytype type; + DBUG_ENTER("_nisam_make_key"); + + start=key; + for (keyseg=info->s->keyinfo[keynr].seg ; keyseg->base.type ;keyseg++) + { + type=(enum ha_base_keytype) keyseg->base.type; + if (keyseg->base.flag & HA_SPACE_PACK) + { + pos= (byte*) record+keyseg->base.start; end=pos+keyseg->base.length; + if (type != HA_KEYTYPE_NUM) + { + while (end > pos && end[-1] == ' ') + end--; + } + else + { + while (pos < end && pos[0] == ' ') + pos++; + } + *key++= (uchar) (length=(uint) (end-pos)); + memcpy((byte*) key,(byte*) pos,(size_t) length); +#ifdef USE_STRCOLL + if (!use_strcoll(default_charset_info)) +#endif + { + if (type == HA_KEYTYPE_TEXT) + case_sort((byte*) key,length); + } + key+=length; + } + else + { + memcpy((byte*) key,(byte*) record+keyseg->base.start, + (size_t) keyseg->base.length); +#ifdef USE_STRCOLL + if (!use_strcoll(default_charset_info)) +#endif + { + if (type == HA_KEYTYPE_TEXT) + case_sort((byte*) key,(uint) keyseg->base.length); + } +#ifdef NAN_TEST + else if (type == HA_KEYTYPE_FLOAT) + { + float nr; + bmove((byte*) &nr,(byte*) key,sizeof(float)); + if (nr == (float) FLT_MAX) + { + nr= (float) FLT_MAX; + bmove((byte*) key,(byte*) &nr,sizeof(float)); + } + } + else if (type == HA_KEYTYPE_DOUBLE) + { + double nr; + bmove((byte*) &nr,(byte*) key,sizeof(double)); + if (nr == DBL_MAX) + { + nr=DBL_MAX; + bmove((byte*) key,(byte*) &nr,sizeof(double)); + } + } +#endif + key+= keyseg->base.length; + } + } + _nisam_dpointer(info,key,filepos); + DBUG_PRINT("exit",("keynr: %d",keynr)); + DBUG_DUMP("key",(byte*) start,(uint) (key-start)+keyseg->base.length); + DBUG_EXECUTE("key",_nisam_print_key(DBUG_FILE,info->s->keyinfo[keynr].seg,start);); + DBUG_RETURN((uint) (key-start)); /* Return keylength */ +} /* _nisam_make_key */ + + + /* Pack a key to intern format from given format (c_rkey) */ + /* if key_length is set returns new length of key */ + +uint _nisam_pack_key(register N_INFO *info, uint keynr, uchar *key, uchar *old, uint key_length) + + + + /* Length of used key */ +{ + int k_length; + uint length; + uchar *pos,*end; + reg1 N_KEYSEG *keyseg; + enum ha_base_keytype type; + DBUG_ENTER("_nisam_pack_key"); + + if ((k_length=(int) key_length) <= 0) + k_length=N_MAX_KEY_BUFF; + + for (keyseg=info->s->keyinfo[keynr].seg ; + keyseg->base.type && k_length >0; + k_length-=keyseg->base.length, old+=keyseg->base.length, keyseg++) + { + length=min((uint) keyseg->base.length,(uint) k_length); + type=(enum ha_base_keytype) keyseg->base.type; + if (keyseg->base.flag & HA_SPACE_PACK) + { + pos=old; end=pos+length; + if (type != HA_KEYTYPE_NUM) + { + while (end > pos && end[-1] == ' ') + end--; + } + else + { + while (pos < end && pos[0] == ' ') + pos++; + } + *key++ = (uchar) (length=(uint) (end-pos)); + memcpy((byte*) key,pos,(size_t) length); + } + else + memcpy((byte*) key,old,(size_t) length); +#ifdef USE_STRCOLL + if (!use_strcoll(default_charset_info)) +#endif + { + if (type == HA_KEYTYPE_TEXT) + case_sort((byte*) key,length); + } + key+= length; + } + if (!keyseg->base.type) + { + if (k_length >= 0) /* Hole key */ + key_length=0; + } + else + { /* Part-key ; fill with null */ + length= (uint) -k_length; /* unused part of last key */ + do + { + length+= (keyseg->base.flag & HA_SPACE_PACK) ? 1 : + keyseg->base.length; + keyseg++; + } while (keyseg->base.type); + bzero((byte*) key,length); + } + DBUG_RETURN(key_length); /* Return part-keylength */ +} /* _nisam_pack_key */ + + + /* Put a key in record */ + /* Used when only-keyread is wanted */ + +static void _nisam_put_key_in_record(register N_INFO *info, uint keynr, byte *record) +{ + uint length; + reg2 byte *key; + byte *pos; + reg1 N_KEYSEG *keyseg; + DBUG_ENTER("_nisam_put_key_in_record"); + + key=(byte*) info->lastkey; + for (keyseg=info->s->keyinfo[keynr].seg ; keyseg->base.type ;keyseg++) + { + if (keyseg->base.flag & HA_SPACE_PACK) + { + length= (uint) (uchar) *key++; + pos= record+keyseg->base.start; + if (keyseg->base.type != (int) HA_KEYTYPE_NUM) + { + memcpy(pos,key,(size_t) length); + bfill(pos+length,keyseg->base.length-length,' '); + } + else + { + bfill(pos,keyseg->base.length-length,' '); + memcpy(pos+keyseg->base.length-length,key,(size_t) length); + } + key+=length; + } + else + { + memcpy(record+keyseg->base.start,(byte*) key, + (size_t) keyseg->base.length); + key+= keyseg->base.length; + } + } + DBUG_VOID_RETURN; +} /* _nisam_put_key_in_record */ + + + /* Here when key reads are used */ + +int _nisam_read_key_record(N_INFO *info, ulong filepos, byte *buf) +{ + VOID(_nisam_writeinfo(info,0)); + if (filepos != NI_POS_ERROR) + { + if (info->lastinx >= 0) + { /* Read only key */ + _nisam_put_key_in_record(info,(uint) info->lastinx,buf); + info->update|= HA_STATE_AKTIV; /* We should find a record */ + return 0; + } + my_errno=HA_ERR_WRONG_INDEX; + return(-1); + } + return(-1); /* Wrong data to read */ +} |