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/* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 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
{
mysql_rwlock_t mutex;
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);
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