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+/* Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+
+ 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 */
+
+#ifndef _SQL_CACHE_H
+#define _SQL_CACHE_H
+
+#include "hash.h"
+#include "my_base.h" /* ha_rows */
+
+class MY_LOCALE;
+struct TABLE_LIST;
+class Time_zone;
+struct LEX;
+struct TABLE;
+typedef struct st_changed_table_list CHANGED_TABLE_LIST;
+
+/* Query cache */
+
+/*
+ Can't create new free memory block if unused memory in block less
+ then QUERY_CACHE_MIN_ALLOCATION_UNIT.
+ if QUERY_CACHE_MIN_ALLOCATION_UNIT == 0 then
+ QUERY_CACHE_MIN_ALLOCATION_UNIT choosed automaticaly
+*/
+#define QUERY_CACHE_MIN_ALLOCATION_UNIT 512
+
+/* inittial size of hashes */
+#define QUERY_CACHE_DEF_QUERY_HASH_SIZE 1024
+#define QUERY_CACHE_DEF_TABLE_HASH_SIZE 1024
+
+/* minimal result data size when data allocated */
+#define QUERY_CACHE_MIN_RESULT_DATA_SIZE (1024*4)
+
+/*
+ start estimation of first result block size only when number of queries
+ bigger then:
+*/
+#define QUERY_CACHE_MIN_ESTIMATED_QUERIES_NUMBER 3
+
+
+
+/* memory bins size spacing (see at Query_cache::init_cache (sql_cache.cc)) */
+#define QUERY_CACHE_MEM_BIN_FIRST_STEP_PWR2 4
+#define QUERY_CACHE_MEM_BIN_STEP_PWR2 2
+#define QUERY_CACHE_MEM_BIN_PARTS_INC 1
+#define QUERY_CACHE_MEM_BIN_PARTS_MUL 1.2
+#define QUERY_CACHE_MEM_BIN_SPC_LIM_PWR2 3
+
+/* how many free blocks check when finding most suitable before other 'end'
+ of list of free blocks */
+#define QUERY_CACHE_MEM_BIN_TRY 5
+
+/* packing parameters */
+#define QUERY_CACHE_PACK_ITERATION 2
+#define QUERY_CACHE_PACK_LIMIT (512*1024L)
+
+#define TABLE_COUNTER_TYPE uint
+
+struct Query_cache_block;
+struct Query_cache_block_table;
+struct Query_cache_table;
+struct Query_cache_query;
+struct Query_cache_result;
+class Query_cache;
+struct Query_cache_tls;
+struct LEX;
+class THD;
+
+typedef my_bool (*qc_engine_callback)(THD *thd, const char *table_key,
+ uint key_length,
+ ulonglong *engine_data);
+
+/**
+ This class represents a node in the linked chain of queries
+ belonging to one table.
+
+ @note The root of this linked list is not a query-type block, but the table-
+ type block which all queries has in common.
+*/
+struct Query_cache_block_table
+{
+ Query_cache_block_table() {} /* Remove gcc warning */
+
+ /**
+ This node holds a position in a static table list belonging
+ to the associated query (base 0).
+ */
+ TABLE_COUNTER_TYPE n;
+
+ /**
+ Pointers to the next and previous node, linking all queries with
+ a common table.
+ */
+ Query_cache_block_table *next, *prev;
+
+ /**
+ A pointer to the table-type block which all
+ linked queries has in common.
+ */
+ Query_cache_table *parent;
+
+ /**
+ A method to calculate the address of the query cache block
+ owning this node. The purpose of this calculation is to
+ make it easier to move the query cache block without having
+ to modify all the pointer addresses.
+ */
+ inline Query_cache_block *block();
+};
+
+struct Query_cache_block
+{
+ Query_cache_block() {} /* Remove gcc warning */
+ enum block_type {FREE, QUERY, RESULT, RES_CONT, RES_BEG,
+ RES_INCOMPLETE, TABLE, INCOMPLETE};
+
+ size_t length; // length of all block
+ size_t used; // length of data
+ /*
+ Not used **pprev, **prev because really needed access to pervious block:
+ *pprev to join free blocks
+ *prev to access to opposite side of list in cyclic sorted list
+ */
+ Query_cache_block *pnext,*pprev, // physical next/previous block
+ *next,*prev; // logical next/previous block
+ block_type type;
+ TABLE_COUNTER_TYPE n_tables; // number of tables in query
+
+ inline bool is_free(void) { return type == FREE; }
+ void init(size_t length);
+ void destroy();
+ uint headers_len();
+ uchar* data(void);
+ Query_cache_query *query();
+ Query_cache_table *table();
+ Query_cache_result *result();
+ Query_cache_block_table *table(TABLE_COUNTER_TYPE n);
+};
+
+struct Query_cache_query
+{
+ ulonglong limit_found_rows;
+ mysql_rwlock_t lock;
+ Query_cache_block *res;
+ Query_cache_tls *wri;
+ size_t len;
+ unsigned int last_pkt_nr;
+ uint8 tbls_type;
+ uint8 ready;
+ ulonglong hit_count;
+
+ Query_cache_query() {} /* Remove gcc warning */
+ inline void init_n_lock();
+ void unlock_n_destroy();
+ inline ulonglong found_rows() { return limit_found_rows; }
+ inline void found_rows(ulonglong rows) { limit_found_rows= rows; }
+ inline Query_cache_block *result() { return res; }
+ inline void result(Query_cache_block *p) { res= p; }
+ inline Query_cache_tls *writer() { return wri; }
+ inline void writer(Query_cache_tls *p) { wri= p; }
+ inline uint8 tables_type() { return tbls_type; }
+ inline void tables_type(uint8 type) { tbls_type= type; }
+ inline size_t length() { return len; }
+ inline size_t add(size_t packet_len) { return(len+= packet_len); }
+ inline void length(size_t length_arg) { len= length_arg; }
+ inline uchar* query()
+ {
+ return (((uchar*)this) + ALIGN_SIZE(sizeof(Query_cache_query)));
+ }
+ /**
+ following used to check if result ready in plugin without
+ locking rw_lock of the query.
+ */
+ inline void set_results_ready() { ready= 1; }
+ inline bool is_results_ready() { return ready; }
+ inline void increment_hits() { hit_count++; }
+ inline ulonglong hits() { return hit_count; }
+ void lock_writing();
+ void lock_reading();
+ bool try_lock_writing();
+ void unlock_writing();
+ void unlock_reading();
+};
+
+
+struct Query_cache_table
+{
+ Query_cache_table() {} /* Remove gcc warning */
+ char *tbl;
+ uint32 key_len;
+ uint8 suffix_len; /* For partitioned tables */
+ uint8 table_type;
+ /* unique for every engine reference */
+ qc_engine_callback callback_func;
+ /* data need by some engines */
+ ulonglong engine_data_buff;
+
+ /**
+ The number of queries depending of this table.
+ */
+ int32 m_cached_query_count;
+ /**
+ If table included in the table hash to be found by other queries
+ */
+ my_bool hashed;
+
+ inline char *db() { return (char *) data(); }
+ inline char *table() { return tbl; }
+ inline void table(char *table_arg) { tbl= table_arg; }
+ inline uint32 key_length() { return key_len; }
+ inline void key_length(uint32 len) { key_len= len; }
+ inline uint8 suffix_length() { return suffix_len; }
+ inline void suffix_length(uint8 len) { suffix_len= len; }
+ inline uint8 type() { return table_type; }
+ inline void type(uint8 t) { table_type= t; }
+ inline qc_engine_callback callback() { return callback_func; }
+ inline void callback(qc_engine_callback fn){ callback_func= fn; }
+ inline ulonglong engine_data() { return engine_data_buff; }
+ inline void engine_data(ulonglong data_arg){ engine_data_buff= data_arg; }
+ inline my_bool is_hashed() { return hashed; }
+ inline void set_hashed(my_bool hash) { hashed= hash; }
+ inline uchar* data()
+ {
+ return (uchar*)(((uchar*)this)+
+ ALIGN_SIZE(sizeof(Query_cache_table)));
+ }
+};
+
+struct Query_cache_result
+{
+ Query_cache_result() {} /* Remove gcc warning */
+ Query_cache_block *query;
+
+ inline uchar* data()
+ {
+ return (uchar*)(((uchar*) this)+
+ ALIGN_SIZE(sizeof(Query_cache_result)));
+ }
+ /* data_continue (if not whole packet contained by this block) */
+ inline Query_cache_block *parent() { return query; }
+ inline void parent (Query_cache_block *p) { query=p; }
+};
+
+
+extern "C"
+{
+ uchar *query_cache_query_get_key(const uchar *record, size_t *length,
+ my_bool not_used);
+ uchar *query_cache_table_get_key(const uchar *record, size_t *length,
+ my_bool not_used);
+}
+extern "C" void query_cache_invalidate_by_MyISAM_filename(const char* filename);
+
+
+struct Query_cache_memory_bin
+{
+ Query_cache_memory_bin() {} /* Remove gcc warning */
+#ifndef DBUG_OFF
+ size_t size;
+#endif
+ uint number;
+ Query_cache_block *free_blocks;
+
+ inline void init(size_t size_arg)
+ {
+#ifndef DBUG_OFF
+ size = size_arg;
+#endif
+ number = 0;
+ free_blocks = 0;
+ }
+};
+
+struct Query_cache_memory_bin_step
+{
+ Query_cache_memory_bin_step() {} /* Remove gcc warning */
+ size_t size;
+ size_t increment;
+ size_t idx;
+ inline void init(size_t size_arg, size_t idx_arg, size_t increment_arg)
+ {
+ size = size_arg;
+ idx = idx_arg;
+ increment = increment_arg;
+ }
+};
+
+class Query_cache
+{
+public:
+ /* Info */
+ size_t query_cache_size, query_cache_limit;
+ /* statistics */
+ size_t free_memory, queries_in_cache, hits, inserts, refused,
+ free_memory_blocks, total_blocks, lowmem_prunes;
+
+
+private:
+#ifndef DBUG_OFF
+ my_thread_id m_cache_lock_thread_id;
+#endif
+ mysql_cond_t COND_cache_status_changed;
+ uint m_requests_in_progress;
+ enum Cache_lock_status { UNLOCKED, LOCKED_NO_WAIT, LOCKED };
+ Cache_lock_status m_cache_lock_status;
+ enum Cache_staus {OK, DISABLE_REQUEST, DISABLED};
+ Cache_staus m_cache_status;
+
+ void free_query_internal(Query_cache_block *point);
+ void invalidate_table_internal(THD *thd, uchar *key, size_t key_length);
+
+protected:
+ /*
+ The following mutex is locked when searching or changing global
+ query, tables lists or hashes. When we are operating inside the
+ query structure we locked an internal query block mutex.
+ LOCK SEQUENCE (to prevent deadlocks):
+ 1. structure_guard_mutex
+ 2. query block (for operation inside query (query block/results))
+
+ Thread doing cache flush releases the mutex once it sets
+ m_cache_lock_status flag, so other threads may bypass the cache as
+ if it is disabled, not waiting for reset to finish. The exception
+ is other threads that were going to do cache flush---they'll wait
+ till the end of a flush operation.
+ */
+ mysql_mutex_t structure_guard_mutex;
+ size_t additional_data_size;
+ uchar *cache; // cache memory
+ Query_cache_block *first_block; // physical location block list
+ Query_cache_block *queries_blocks; // query list (LIFO)
+ Query_cache_block *tables_blocks;
+
+ Query_cache_memory_bin *bins; // free block lists
+ Query_cache_memory_bin_step *steps; // bins spacing info
+ HASH queries, tables;
+ /* options */
+ size_t min_allocation_unit, min_result_data_size;
+ uint def_query_hash_size, def_table_hash_size;
+
+ size_t mem_bin_num, mem_bin_steps; // See at init_cache & find_bin
+
+ bool initialized;
+
+ /* Exclude/include from cyclic double linked list */
+ static void double_linked_list_exclude(Query_cache_block *point,
+ Query_cache_block **list_pointer);
+ static void double_linked_list_simple_include(Query_cache_block *point,
+ Query_cache_block **
+ list_pointer);
+ static void double_linked_list_join(Query_cache_block *head_tail,
+ Query_cache_block *tail_head);
+
+ /* The following functions require that structure_guard_mutex is locked */
+ void flush_cache();
+ my_bool free_old_query();
+ void free_query(Query_cache_block *point);
+ my_bool allocate_data_chain(Query_cache_block **result_block,
+ size_t data_len,
+ Query_cache_block *query_block,
+ my_bool first_block);
+ void invalidate_table(THD *thd, TABLE_LIST *table);
+ void invalidate_table(THD *thd, TABLE *table);
+ void invalidate_table(THD *thd, uchar *key, size_t key_length);
+ void invalidate_table(THD *thd, Query_cache_block *table_block);
+ void invalidate_query_block_list(THD *thd,
+ Query_cache_block_table *list_root);
+
+ TABLE_COUNTER_TYPE
+ register_tables_from_list(THD *thd, TABLE_LIST *tables_used,
+ TABLE_COUNTER_TYPE counter,
+ Query_cache_block_table **block_table);
+ my_bool register_all_tables(THD *thd, Query_cache_block *block,
+ TABLE_LIST *tables_used,
+ TABLE_COUNTER_TYPE tables);
+ void unlink_table(Query_cache_block_table *node);
+ Query_cache_block *get_free_block (size_t len, my_bool not_less,
+ size_t min);
+ void free_memory_block(Query_cache_block *point);
+ void split_block(Query_cache_block *block, size_t len);
+ Query_cache_block *join_free_blocks(Query_cache_block *first_block,
+ Query_cache_block *block_in_list);
+ my_bool append_next_free_block(Query_cache_block *block,
+ size_t add_size);
+ void exclude_from_free_memory_list(Query_cache_block *free_block);
+ void insert_into_free_memory_list(Query_cache_block *new_block);
+ my_bool move_by_type(uchar **border, Query_cache_block **before,
+ size_t *gap, Query_cache_block *i);
+ uint find_bin(size_t size);
+ void move_to_query_list_end(Query_cache_block *block);
+ void insert_into_free_memory_sorted_list(Query_cache_block *new_block,
+ Query_cache_block **list);
+ void pack_cache();
+ void relink(Query_cache_block *oblock,
+ Query_cache_block *nblock,
+ Query_cache_block *next,
+ Query_cache_block *prev,
+ Query_cache_block *pnext,
+ Query_cache_block *pprev);
+ my_bool join_results(size_t join_limit);
+
+ /*
+ Following function control structure_guard_mutex
+ by themself or don't need structure_guard_mutex
+ */
+ size_t init_cache();
+ void make_disabled();
+ void free_cache();
+ Query_cache_block *write_block_data(size_t data_len, uchar* data,
+ size_t header_len,
+ Query_cache_block::block_type type,
+ TABLE_COUNTER_TYPE ntab = 0);
+ my_bool append_result_data(Query_cache_block **result,
+ size_t data_len, uchar* data,
+ Query_cache_block *parent);
+ my_bool write_result_data(Query_cache_block **result,
+ size_t data_len, uchar* data,
+ Query_cache_block *parent,
+ Query_cache_block::block_type
+ type=Query_cache_block::RESULT);
+ inline size_t get_min_first_result_data_size();
+ inline size_t get_min_append_result_data_size();
+ Query_cache_block *allocate_block(size_t len, my_bool not_less,
+ size_t min);
+ /*
+ If query is cacheable return number tables in query
+ (query without tables not cached)
+ */
+ TABLE_COUNTER_TYPE is_cacheable(THD *thd,
+ LEX *lex, TABLE_LIST *tables_used,
+ uint8 *tables_type);
+ TABLE_COUNTER_TYPE process_and_count_tables(THD *thd,
+ TABLE_LIST *tables_used,
+ uint8 *tables_type);
+
+ static my_bool ask_handler_allowance(THD *thd, TABLE_LIST *tables_used);
+ public:
+
+ Query_cache(size_t query_cache_limit = ULONG_MAX,
+ size_t min_allocation_unit = QUERY_CACHE_MIN_ALLOCATION_UNIT,
+ size_t min_result_data_size = QUERY_CACHE_MIN_RESULT_DATA_SIZE,
+ uint def_query_hash_size = QUERY_CACHE_DEF_QUERY_HASH_SIZE,
+ uint def_table_hash_size = QUERY_CACHE_DEF_TABLE_HASH_SIZE);
+
+ inline bool is_disabled(void) { return m_cache_status != OK; }
+ inline bool is_disable_in_progress(void)
+ { return m_cache_status == DISABLE_REQUEST; }
+
+ /* initialize cache (mutex) */
+ void init();
+ /* resize query cache (return real query size, 0 if disabled) */
+ size_t resize(size_t query_cache_size);
+ /* set limit on result size */
+ inline void result_size_limit(size_t limit){query_cache_limit=limit;}
+ /* set minimal result data allocation unit size */
+ size_t set_min_res_unit(size_t size);
+
+ /* register query in cache */
+ void store_query(THD *thd, TABLE_LIST *used_tables);
+
+ /*
+ Check if the query is in the cache and if this is true send the
+ data to client.
+ */
+ int send_result_to_client(THD *thd, char *query, uint query_length);
+
+ /* Remove all queries that uses any of the listed following tables */
+ void invalidate(THD *thd, TABLE_LIST *tables_used,
+ my_bool using_transactions);
+ void invalidate(THD *thd, CHANGED_TABLE_LIST *tables_used);
+ void invalidate_locked_for_write(THD *thd, TABLE_LIST *tables_used);
+ void invalidate(THD *thd, TABLE *table, my_bool using_transactions);
+ void invalidate(THD *thd, const char *key, size_t key_length,
+ my_bool using_transactions);
+
+ /* Remove all queries that uses any of the tables in following database */
+ void invalidate(THD *thd, const char *db);
+
+ /* Remove all queries that uses any of the listed following table */
+ void invalidate_by_MyISAM_filename(const char *filename);
+
+ void flush();
+ void pack(THD *thd,
+ size_t join_limit = QUERY_CACHE_PACK_LIMIT,
+ uint iteration_limit = QUERY_CACHE_PACK_ITERATION);
+
+ void destroy();
+
+ void insert(THD *thd, Query_cache_tls *query_cache_tls,
+ const char *packet,
+ size_t length,
+ unsigned pkt_nr);
+ my_bool insert_table(THD *thd, size_t key_len, const char *key,
+ Query_cache_block_table *node,
+ size_t db_length, uint8 suffix_length_arg,
+ uint8 cache_type,
+ qc_engine_callback callback,
+ ulonglong engine_data,
+ my_bool hash);
+
+ void end_of_result(THD *thd);
+ void abort(THD *thd, Query_cache_tls *query_cache_tls);
+
+ /*
+ The following functions are only used when debugging
+ We don't protect these with ifndef DBUG_OFF to not have to recompile
+ everything if we want to add checks of the cache at some places.
+ */
+ void wreck(uint line, const char *message);
+ void bins_dump();
+ void cache_dump();
+ void queries_dump();
+ void tables_dump();
+ my_bool check_integrity(bool not_locked);
+ my_bool in_list(Query_cache_block * root, Query_cache_block * point,
+ const char *name);
+ my_bool in_table_list(Query_cache_block_table * root,
+ Query_cache_block_table * point,
+ const char *name);
+ my_bool in_blocks(Query_cache_block * point);
+
+ /* Table key generation */
+ static uint filename_2_table_key (char *key, const char *filename,
+ uint32 *db_langth);
+
+ enum Cache_try_lock_mode {WAIT, TIMEOUT, TRY};
+ bool try_lock(THD *thd, Cache_try_lock_mode mode= WAIT);
+ void lock(THD *thd);
+ void lock_and_suspend(void);
+ void unlock(void);
+
+ void disable_query_cache(THD *thd);
+};
+
+#ifdef HAVE_QUERY_CACHE
+struct Query_cache_query_flags
+{
+ unsigned int client_long_flag:1;
+ unsigned int client_protocol_41:1;
+ unsigned int client_depr_eof:1;
+ unsigned int protocol_type:2;
+ unsigned int more_results_exists:1;
+ unsigned int in_trans:1;
+ unsigned int autocommit:1;
+ unsigned int pkt_nr;
+ uint character_set_client_num;
+ uint character_set_results_num;
+ uint collation_connection_num;
+ uint group_concat_max_len;
+ ha_rows limit;
+ Time_zone *time_zone;
+ sql_mode_t sql_mode;
+ ulonglong max_sort_length;
+ size_t default_week_format;
+ size_t div_precision_increment;
+ MY_LOCALE *lc_time_names;
+};
+#define QUERY_CACHE_FLAGS_SIZE sizeof(Query_cache_query_flags)
+#define QUERY_CACHE_DB_LENGTH_SIZE 2
+#include "sql_cache.h"
+#define query_cache_abort(A,B) query_cache.abort(A,B)
+#define query_cache_end_of_result(A) query_cache.end_of_result(A)
+#define query_cache_store_query(A, B) query_cache.store_query(A, B)
+#define query_cache_destroy() query_cache.destroy()
+#define query_cache_result_size_limit(A) query_cache.result_size_limit(A)
+#define query_cache_init() query_cache.init()
+#define query_cache_resize(A) query_cache.resize(A)
+#define query_cache_set_min_res_unit(A) query_cache.set_min_res_unit(A)
+#define query_cache_invalidate3(A, B, C) query_cache.invalidate(A, B, C)
+#define query_cache_invalidate1(A, B) query_cache.invalidate(A, B)
+#define query_cache_send_result_to_client(A, B, C) \
+ query_cache.send_result_to_client(A, B, C)
+#define query_cache_invalidate_by_MyISAM_filename_ref \
+ &query_cache_invalidate_by_MyISAM_filename
+/* note the "maybe": it's a read without mutex */
+#define query_cache_maybe_disabled(T) \
+ (T->variables.query_cache_type == 0 || query_cache.query_cache_size == 0)
+#define query_cache_is_cacheable_query(L) \
+ (((L)->sql_command == SQLCOM_SELECT) && (L)->safe_to_cache_query)
+#else
+#define QUERY_CACHE_FLAGS_SIZE 0
+#define query_cache_store_query(A, B) do { } while(0)
+#define query_cache_destroy() do { } while(0)
+#define query_cache_result_size_limit(A) do { } while(0)
+#define query_cache_init() do { } while(0)
+#define query_cache_resize(A) do { } while(0)
+#define query_cache_set_min_res_unit(A) do { } while(0)
+#define query_cache_invalidate3(A, B, C) do { } while(0)
+#define query_cache_invalidate1(A,B) do { } while(0)
+#define query_cache_send_result_to_client(A, B, C) 0
+#define query_cache_invalidate_by_MyISAM_filename_ref NULL
+
+#define query_cache_abort(A,B) do { } while(0)
+#define query_cache_end_of_result(A) do { } while(0)
+#define query_cache_maybe_disabled(T) 1
+#define query_cache_is_cacheable_query(L) 0
+#endif /*HAVE_QUERY_CACHE*/
+
+extern MYSQL_PLUGIN_IMPORT Query_cache query_cache;
+#endif
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