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Diffstat (limited to 'sql/keycaches.cc')
| -rw-r--r-- | sql/keycaches.cc | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/sql/keycaches.cc b/sql/keycaches.cc new file mode 100644 index 00000000000..d68e2bccd96 --- /dev/null +++ b/sql/keycaches.cc @@ -0,0 +1,163 @@ +/* Copyright (C) 2002-2006 MySQL AB, 2009 Sun Microsystems, Inc. + + 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +#include "keycaches.h" + +/**************************************************************************** + Named list handling +****************************************************************************/ + +NAMED_ILIST key_caches; + +/** + ilink (intrusive list element) with a name +*/ +class NAMED_ILINK :public ilink +{ +public: + const char *name; + uint name_length; + uchar* data; + + NAMED_ILINK(I_List<NAMED_ILINK> *links, const char *name_arg, + uint name_length_arg, uchar* data_arg) + :name_length(name_length_arg), data(data_arg) + { + name= my_strndup(name_arg, name_length, MYF(MY_WME)); + links->push_back(this); + } + inline bool cmp(const char *name_cmp, uint length) + { + return length == name_length && !memcmp(name, name_cmp, length); + } + ~NAMED_ILINK() + { + my_free((uchar*) name, MYF(0)); + } +}; + +uchar* find_named(I_List<NAMED_ILINK> *list, const char *name, uint length, + NAMED_ILINK **found) +{ + I_List_iterator<NAMED_ILINK> it(*list); + NAMED_ILINK *element; + while ((element= it++)) + { + if (element->cmp(name, length)) + { + if (found) + *found= element; + return element->data; + } + } + return 0; +} + + +void NAMED_ILIST::delete_elements(void (*free_element)(const char *name, uchar*)) +{ + NAMED_ILINK *element; + DBUG_ENTER("NAMED_ILIST::delete_elements"); + while ((element= get())) + { + (*free_element)(element->name, element->data); + delete element; + } + DBUG_VOID_RETURN; +} + + +/* Key cache functions */ + +LEX_STRING default_key_cache_base= {C_STRING_WITH_LEN("default")}; + +KEY_CACHE zero_key_cache; ///< @@nonexistent_cache.param->value_ptr() points here + +KEY_CACHE *get_key_cache(LEX_STRING *cache_name) +{ + if (!cache_name || ! cache_name->length) + cache_name= &default_key_cache_base; + return ((KEY_CACHE*) find_named(&key_caches, + cache_name->str, cache_name->length, 0)); +} + +KEY_CACHE *create_key_cache(const char *name, uint length) +{ + KEY_CACHE *key_cache; + DBUG_ENTER("create_key_cache"); + DBUG_PRINT("enter",("name: %.*s", length, name)); + + if ((key_cache= (KEY_CACHE*) my_malloc(sizeof(KEY_CACHE), + MYF(MY_ZEROFILL | MY_WME)))) + { + if (!new NAMED_ILINK(&key_caches, name, length, (uchar*) key_cache)) + { + my_free((char*) key_cache, MYF(0)); + key_cache= 0; + } + else + { + /* + Set default values for a key cache + The values in dflt_key_cache_var is set by my_getopt() at startup + + We don't set 'buff_size' as this is used to enable the key cache + */ + key_cache->param_block_size= dflt_key_cache_var.param_block_size; + key_cache->param_division_limit= dflt_key_cache_var.param_division_limit; + key_cache->param_age_threshold= dflt_key_cache_var.param_age_threshold; + } + } + DBUG_RETURN(key_cache); +} + + +KEY_CACHE *get_or_create_key_cache(const char *name, uint length) +{ + LEX_STRING key_cache_name; + KEY_CACHE *key_cache; + + key_cache_name.str= (char *) name; + key_cache_name.length= length; + if (!(key_cache= get_key_cache(&key_cache_name))) + key_cache= create_key_cache(name, length); + return key_cache; +} + + +void free_key_cache(const char *name, KEY_CACHE *key_cache) +{ + end_key_cache(key_cache, 1); // Can never fail + my_free((char*) key_cache, MYF(0)); +} + + +bool process_key_caches(process_key_cache_t func) +{ + I_List_iterator<NAMED_ILINK> it(key_caches); + NAMED_ILINK *element; + + while ((element= it++)) + { + KEY_CACHE *key_cache= (KEY_CACHE *) element->data; + func(element->name, key_cache); + } + return 0; +} + +#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION +template class I_List_iterator<NAMED_ILINK>; +#endif + |