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Diffstat (limited to 'storage/myisammrg/myrg_rkey.c')
-rw-r--r--storage/myisammrg/myrg_rkey.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/storage/myisammrg/myrg_rkey.c b/storage/myisammrg/myrg_rkey.c
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index 00000000000..a85ef6a3b5e
--- /dev/null
+++ b/storage/myisammrg/myrg_rkey.c
@@ -0,0 +1,87 @@
+/* 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 */
+
+/* Read record based on a key */
+
+/*
+ * HA_READ_KEY_EXACT => SEARCH_BIGGER
+ * HA_READ_KEY_OR_NEXT => SEARCH_BIGGER
+ * HA_READ_AFTER_KEY => SEARCH_BIGGER
+ * HA_READ_PREFIX => SEARCH_BIGGER
+ * HA_READ_KEY_OR_PREV => SEARCH_SMALLER
+ * HA_READ_BEFORE_KEY => SEARCH_SMALLER
+ * HA_READ_PREFIX_LAST => SEARCH_SMALLER
+ */
+
+
+#include "myrg_def.h"
+
+/* todo: we could store some additional info to speedup lookups:
+ column (key, keyseg) can be constant per table
+ it can also be increasing (table1.val > table2.val > ...),
+ or decreasing, <=, >=, etc.
+ SerG
+*/
+
+int myrg_rkey(MYRG_INFO *info,byte *buf,int inx, const byte *key,
+ uint key_len, enum ha_rkey_function search_flag)
+{
+ byte *key_buff;
+ uint pack_key_length;
+ MYRG_TABLE *table;
+ MI_INFO *mi;
+ int err;
+ LINT_INIT(key_buff);
+ LINT_INIT(pack_key_length);
+
+ if (_myrg_init_queue(info,inx,search_flag))
+ return my_errno;
+
+ for (table=info->open_tables ; table != info->end_table ; table++)
+ {
+ mi=table->table;
+
+ if (table == info->open_tables)
+ {
+ err=mi_rkey(mi,0,inx,key,key_len,search_flag);
+ key_buff=(byte*) mi->lastkey+mi->s->base.max_key_length;
+ pack_key_length=mi->last_rkey_length;
+ }
+ else
+ {
+ mi->once_flags|= USE_PACKED_KEYS;
+ err=mi_rkey(mi,0,inx,key_buff,pack_key_length,search_flag);
+ }
+ info->last_used_table=table+1;
+
+ if (err)
+ {
+ if (err == HA_ERR_KEY_NOT_FOUND)
+ continue;
+ return err;
+ }
+ /* adding to queue */
+ queue_insert(&(info->by_key),(byte *)table);
+
+ }
+
+ if (!info->by_key.elements)
+ return HA_ERR_KEY_NOT_FOUND;
+
+ mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
+ mi->once_flags|= RRND_PRESERVE_LASTINX;
+ return _myrg_mi_read_record(mi,buf);
+}