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author | serg@infomag.ape.relarn.ru <> | 2000-08-14 15:27:19 +0400 |
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committer | serg@infomag.ape.relarn.ru <> | 2000-08-14 15:27:19 +0400 |
commit | 5886090182881b29143091c9bb4d7e7b406ea5df (patch) | |
tree | 290f97643db41800f2922e6143b2a89e93d5476d /myisammrg/myrg_rprev.c | |
parent | 807460bbceceec25bf97352bc5e232c3e766d70f (diff) | |
download | mariadb-git-5886090182881b29143091c9bb4d7e7b406ea5df.tar.gz |
PART I: Keys support for MyMERGE tables
myisammrg/ |
Makefile.am |
mymrgdef.h | support for keys
myrg_open.c | &
myrg_queue.c | bugfixes
myrg_rfirst.c |
myrg_rkey.c |
myrg_rlast.c |
myrg_rnext.c |
myrg_rprev.c |
myrg_rrnd.c |
include/myisammrg.h | rkey/rnext/etc prototyped
sql/ |
ha_myisammrg.cc | support for keys
ha_myisammrg.h |
myisam/ |
mi_rkey.c | buf==NULL extension, _mi_rkey()
mi_rnext.c |
mi_rprev.c |
include/queues.h | reinit_queue() - same as init_queue, but w/o malloc
mysys/queues.c |
PART II: Miscellaneous
myisam/common_words | deleted (looks like I checked it in by mistake)
some files (like acconfig.h, Makefile.am, COPYING.LIB, etc)
| Change mode to -rw-r--r-- (by `chmod a-x ')
Diffstat (limited to 'myisammrg/myrg_rprev.c')
-rw-r--r-- | myisammrg/myrg_rprev.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/myisammrg/myrg_rprev.c b/myisammrg/myrg_rprev.c new file mode 100644 index 00000000000..3ee0894b42c --- /dev/null +++ b/myisammrg/myrg_rprev.c @@ -0,0 +1,76 @@ +/* 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 */ + +#include "mymrgdef.h" + + /* + Read previous row with the same key as previous read + */ + +int myrg_rprev(MYRG_INFO *info, byte *buf, int inx) +{ + MYRG_TABLE *table; + MI_INFO *mi; + uchar *key_buff; + uint pack_key_length; + int err; + + /* at first, do rnext for the table found before */ + err=mi_rprev(info->current_table->table,NULL,inx); + if (err == HA_ERR_END_OF_FILE) + { + queue_remove(&(info->by_key),0); + if (!info->by_key.elements) + return HA_ERR_END_OF_FILE; + } + else if (err) + return err; + else + { + /* Found here, adding to queue */ + queue_top(&(info->by_key))=(byte *)(info->current_table); + queue_replaced(&(info->by_key)); + } + + /* next, let's finish myrg_rkey's initial scan */ + table=info->last_used_table+1; + if (table < info->end_table) + { + mi=info->last_used_table->table; + key_buff=mi->lastkey+mi->s->base.max_key_length; + pack_key_length=mi->last_rkey_length; + for (; table < info->end_table ; table++) + { + mi=table->table; + err=_mi_rkey(mi,NULL,inx,key_buff,pack_key_length,HA_READ_KEY_OR_PREV,FALSE); + info->last_used_table=table; + + if (err == HA_ERR_KEY_NOT_FOUND) + continue; + if (err) + return err; + + /* Found here, adding to queue */ + queue_insert(&(info->by_key),(byte *)table); + } + } + + /* now, mymerge's read_prev is as simple as one queue_top */ + mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table; + return mi_rrnd(mi,buf,mi->lastpos); +} + + |