/* Copyright (C) 2003 MySQL 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 */ /* Handling of multiple key caches The idea is to have a thread safe hash on the table name, with a default key cache value that is returned if the table name is not in the cache. */ #include <hash.h> /* Struct to store a key and pointer to object */ typedef struct st_safe_hash_entry { uchar *key; uint length; uchar *data; struct st_safe_hash_entry *next, **prev; } SAFE_HASH_ENTRY; typedef struct st_safe_hash_with_default { #ifdef THREAD rw_lock_t mutex; #endif HASH hash; uchar *default_value; SAFE_HASH_ENTRY *root; } SAFE_HASH; my_bool safe_hash_init(SAFE_HASH *hash, uint elements, uchar *default_value); void safe_hash_free(SAFE_HASH *hash); uchar *safe_hash_search(SAFE_HASH *hash, const uchar *key, uint length, uchar *def); my_bool safe_hash_set(SAFE_HASH *hash, const uchar *key, uint length, uchar *data); void safe_hash_change(SAFE_HASH *hash, uchar *old_data, uchar *new_data);