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Diffstat (limited to 'sql/table_cache.h')
| -rw-r--r-- | sql/table_cache.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/sql/table_cache.h b/sql/table_cache.h new file mode 100644 index 00000000..433df5e0 --- /dev/null +++ b/sql/table_cache.h @@ -0,0 +1,117 @@ +#ifndef TABLE_CACHE_H_INCLUDED +#define TABLE_CACHE_H_INCLUDED +/* Copyright (c) 2000, 2012, Oracle and/or its affiliates. + Copyright (c) 2010, 2011 Monty Program Ab + Copyright (C) 2013 Sergey Vojtovich and MariaDB Foundation + + 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 */ + + +struct Share_free_tables +{ + typedef I_P_List <TABLE, TABLE_share> List; + List list; + /** Avoid false sharing between instances */ + char pad[CPU_LEVEL1_DCACHE_LINESIZE]; +}; + + +struct TDC_element +{ + uchar m_key[NAME_LEN + 1 + NAME_LEN + 1]; + uint m_key_length; + bool flushed; + TABLE_SHARE *share; + + /** + Protects ref_count, m_flush_tickets, all_tables, flushed, all_tables_refs. + */ + mysql_mutex_t LOCK_table_share; + mysql_cond_t COND_release; + TDC_element *next, **prev; /* Link to unused shares */ + uint ref_count; /* How many TABLE objects uses this */ + uint all_tables_refs; /* Number of refs to all_tables */ + /** + List of tickets representing threads waiting for the share to be flushed. + */ + Wait_for_flush_list m_flush_tickets; + /* + Doubly-linked (back-linked) lists of used and unused TABLE objects + for this share. + */ + All_share_tables_list all_tables; + /** Avoid false sharing between TDC_element and free_tables */ + char pad[CPU_LEVEL1_DCACHE_LINESIZE]; + Share_free_tables free_tables[1]; + + inline void wait_for_refs(uint my_refs); + void flush(THD *thd, bool mark_flushed); + void flush_unused(bool mark_flushed); +}; + + +extern ulong tdc_size; +extern ulong tc_size; +extern uint32 tc_instances; + +extern bool tdc_init(void); +extern void tdc_start_shutdown(void); +extern void tdc_deinit(void); +extern ulong tdc_records(void); +extern void tdc_purge(bool all); +extern TDC_element *tdc_lock_share(THD *thd, const char *db, + const char *table_name); +extern void tdc_unlock_share(TDC_element *element); +int tdc_share_is_cached(THD *thd, const char *db, const char *table_name); +extern TABLE_SHARE *tdc_acquire_share(THD *thd, TABLE_LIST *tl, uint flags, + TABLE **out_table= 0); +extern void tdc_release_share(TABLE_SHARE *share); +void tdc_remove_referenced_share(THD *thd, TABLE_SHARE *share); +void tdc_remove_table(THD *thd, const char *db, const char *table_name); + +extern int tdc_wait_for_old_version(THD *thd, const char *db, + const char *table_name, + ulong wait_timeout, uint deadlock_weight); +extern int tdc_iterate(THD *thd, my_hash_walk_action action, void *argument, + bool no_dups= false); + +extern uint tc_records(void); +int show_tc_active_instances(THD *thd, SHOW_VAR *var, char *buff, + enum enum_var_type scope); +extern void tc_purge(); +extern void tc_add_table(THD *thd, TABLE *table); +extern void tc_release_table(TABLE *table); +extern TABLE *tc_acquire_table(THD *thd, TDC_element *element); + +/** + Create a table cache key for non-temporary table. + + @param key Buffer for key (must be at least NAME_LEN*2+2 bytes). + @param db Database name. + @param table_name Table name. + + @return Length of key. +*/ + +inline uint tdc_create_key(char *key, const char *db, const char *table_name) +{ + /* + In theory caller should ensure that both db and table_name are + not longer than NAME_LEN bytes. In practice we play safe to avoid + buffer overruns. + */ + return (uint) (strmake(strmake(key, db, NAME_LEN) + 1, table_name, + NAME_LEN) - key + 1); +} +#endif /* TABLE_CACHE_H_INCLUDED */ |