From a175314c3e5827eb193872241446f2f8f5c9d33c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 20:07:14 +0200 Subject: Adding upstream version 1:10.5.12. Signed-off-by: Daniel Baumann --- mysys/my_safehash.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 mysys/my_safehash.h (limited to 'mysys/my_safehash.h') diff --git a/mysys/my_safehash.h b/mysys/my_safehash.h new file mode 100644 index 00000000..71aaf5d0 --- /dev/null +++ b/mysys/my_safehash.h @@ -0,0 +1,56 @@ +/* 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 + +/* + 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); -- cgit v1.2.3