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/mf_keycaches.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 mysys/mf_keycaches.c (limited to 'mysys/mf_keycaches.c') diff --git a/mysys/mf_keycaches.c b/mysys/mf_keycaches.c new file mode 100644 index 00000000..199fb109 --- /dev/null +++ b/mysys/mf_keycaches.c @@ -0,0 +1,107 @@ +/* Copyright (c) 2003, 2011, Oracle and/or its affiliates. + Copyright (c) 2010, 2011, Monty Program 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; version 2 of the License. + + 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 St, 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 "mysys_priv.h" +#include +#include +#include +#include "my_safehash.h" + +/***************************************************************************** + Functions to handle the key cache objects +*****************************************************************************/ + +/* Variable to store all key cache objects */ +static SAFE_HASH key_cache_hash; + + +my_bool multi_keycache_init(void) +{ + return safe_hash_init(&key_cache_hash, 16, (uchar*) dflt_key_cache); +} + + +void multi_keycache_free(void) +{ + safe_hash_free(&key_cache_hash); +} + +/* + Get a key cache to be used for a specific table. + + SYNOPSIS + multi_key_cache_search() + key key to find (usually table path) + uint length Length of key. + def Default value if no key cache + + NOTES + This function is coded in such a way that we will return the + default key cache even if one never called multi_keycache_init. + This will ensure that it works with old MyISAM clients. + + RETURN + key cache to use +*/ + +KEY_CACHE *multi_key_cache_search(uchar *key, uint length, + KEY_CACHE *def) +{ + if (!key_cache_hash.hash.records) + return def; + return (KEY_CACHE*) safe_hash_search(&key_cache_hash, key, length, + (void*) def); +} + + +/* + Assosiate a key cache with a key + + + SYONOPSIS + multi_key_cache_set() + key key (path to table etc..) + length Length of key + key_cache cache to assococite with the table + + NOTES + This can be used both to insert a new entry and change an existing + entry +*/ + + +my_bool multi_key_cache_set(const uchar *key, uint length, + KEY_CACHE *key_cache) +{ + return safe_hash_set(&key_cache_hash, key, length, (uchar*) key_cache); +} + + +void multi_key_cache_change(KEY_CACHE *old_data, + KEY_CACHE *new_data) +{ + safe_hash_change(&key_cache_hash, (uchar*) old_data, (uchar*) new_data); +} + + -- cgit v1.2.3