diff options
Diffstat (limited to 'include/keycache.h')
| -rw-r--r-- | include/keycache.h | 213 |
1 files changed, 137 insertions, 76 deletions
diff --git a/include/keycache.h b/include/keycache.h index 8c4ee4afe81..acb85522c0e 100644 --- a/include/keycache.h +++ b/include/keycache.h @@ -19,96 +19,146 @@ #define _keycache_h C_MODE_START -/* declare structures that is used by st_key_cache */ -struct st_block_link; -typedef struct st_block_link BLOCK_LINK; -struct st_keycache_page; -typedef struct st_keycache_page KEYCACHE_PAGE; -struct st_hash_link; -typedef struct st_hash_link HASH_LINK; -/* info about requests in a waiting queue */ -typedef struct st_keycache_wqueue -{ - struct st_my_thread_var *last_thread; /* circular list of waiting threads */ -} KEYCACHE_WQUEUE; +/* + Currently the default key cache is created as non-partitioned at + the start of the server unless the server is started with the parameter + --key-cache-partitions that is greater than 0 +*/ + +#define DEFAULT_KEY_CACHE_PARTITIONS 0 + +/* + MAX_KEY_CACHE_PARTITIONS cannot be greater than + sizeof(MYISAM_SHARE::dirty_part_map) + Currently sizeof(MYISAM_SHARE::dirty_part_map)=sizeof(ulonglong) +*/ -#define CHANGED_BLOCKS_HASH 128 /* must be power of 2 */ +#define MAX_KEY_CACHE_PARTITIONS 64 + +/* The structure to get statistical data about a key cache */ + +typedef struct st_key_cache_statistics +{ + ulonglong mem_size; /* memory for cache buffers/auxiliary structures */ + ulonglong block_size; /* size of the each buffers in the key cache */ + ulonglong blocks_used; /* maximum number of used blocks/buffers */ + ulonglong blocks_unused; /* number of currently unused blocks */ + ulonglong blocks_changed; /* number of currently dirty blocks */ + ulonglong blocks_warm; /* number of blocks in warm sub-chain */ + ulonglong read_requests; /* number of read requests (read hits) */ + ulonglong reads; /* number of actual reads from files into buffers */ + ulonglong write_requests; /* number of write requests (write hits) */ + ulonglong writes; /* number of actual writes from buffers into files */ +} KEY_CACHE_STATISTICS; + +#define NUM_LONG_KEY_CACHE_STAT_VARIABLES 3 + +/* The type of a key cache object */ +typedef enum key_cache_type +{ + SIMPLE_KEY_CACHE, + PARTITIONED_KEY_CACHE +} KEY_CACHE_TYPE; + + +typedef + int (*INIT_KEY_CACHE) + (void *, uint key_cache_block_size, + size_t use_mem, uint division_limit, uint age_threshold); +typedef + int (*RESIZE_KEY_CACHE) + (void *, uint key_cache_block_size, + size_t use_mem, uint division_limit, uint age_threshold); +typedef + void (*CHANGE_KEY_CACHE_PARAM) + (void *keycache_cb, + uint division_limit, uint age_threshold); +typedef + uchar* (*KEY_CACHE_READ) + (void *keycache_cb, + File file, my_off_t filepos, int level, + uchar *buff, uint length, + uint block_length, int return_buffer); +typedef + int (*KEY_CACHE_INSERT) + (void *keycache_cb, + File file, my_off_t filepos, int level, + uchar *buff, uint length); +typedef + int (*KEY_CACHE_WRITE) + (void *keycache_cb, + File file, void *file_extra, + my_off_t filepos, int level, + uchar *buff, uint length, + uint block_length, int force_write); +typedef + int (*FLUSH_KEY_BLOCKS) + (void *keycache_cb, + int file, void *file_extra, + enum flush_type type); +typedef + int (*RESET_KEY_CACHE_COUNTERS) + (const char *name, void *keycache_cb); +typedef + void (*END_KEY_CACHE) + (void *keycache_cb, my_bool cleanup); +typedef + void (*GET_KEY_CACHE_STATISTICS) + (void *keycache_cb, uint partition_no, + KEY_CACHE_STATISTICS *key_cache_stats); /* - The key cache structure - It also contains read-only statistics parameters. + An object of the type KEY_CACHE_FUNCS contains pointers to all functions + from the key cache interface. + Currently a key cache can be of two types: simple and partitioned. + For each of them its own static structure of the type KEY_CACHE_FUNCS is + defined . The structures contain the pointers to the implementations of + the interface functions used by simple key caches and partitioned key + caches respectively. Pointers to these structures are assigned to key cache + objects at the time of their creation. */ +typedef struct st_key_cache_funcs +{ + INIT_KEY_CACHE init; + RESIZE_KEY_CACHE resize; + CHANGE_KEY_CACHE_PARAM change_param; + KEY_CACHE_READ read; + KEY_CACHE_INSERT insert; + KEY_CACHE_WRITE write; + FLUSH_KEY_BLOCKS flush; + RESET_KEY_CACHE_COUNTERS reset_counters; + END_KEY_CACHE end; + GET_KEY_CACHE_STATISTICS get_stats; +} KEY_CACHE_FUNCS; + + typedef struct st_key_cache { - my_bool key_cache_inited; - my_bool in_resize; /* true during resize operation */ - my_bool resize_in_flush; /* true during flush of resize operation */ + KEY_CACHE_TYPE key_cache_type; /* type of the key cache used for debugging */ + void *keycache_cb; /* control block of the used key cache */ + KEY_CACHE_FUNCS *interface_funcs; /* interface functions of the key cache */ + ulonglong param_buff_size; /* size the memory allocated for the cache */ + ulong param_block_size; /* size of the blocks in the key cache */ + ulong param_division_limit; /* min. percentage of warm blocks */ + ulong param_age_threshold; /* determines when hot block is downgraded */ + ulong param_partitions; /* number of the key cache partitions */ + my_bool key_cache_inited; /* <=> key cache has been created */ my_bool can_be_used; /* usage of cache for read/write is allowed */ - size_t key_cache_mem_size; /* specified size of the cache memory */ - uint key_cache_block_size; /* size of the page buffer of a cache block */ - ulong min_warm_blocks; /* min number of warm blocks; */ - ulong age_threshold; /* age threshold for hot blocks */ - ulonglong keycache_time; /* total number of block link operations */ - uint hash_entries; /* max number of entries in the hash table */ - int hash_links; /* max number of hash links */ - int hash_links_used; /* number of hash links currently used */ - int disk_blocks; /* max number of blocks in the cache */ - ulong blocks_used; /* maximum number of concurrently used blocks */ - ulong blocks_unused; /* number of currently unused blocks */ - ulong blocks_changed; /* number of currently dirty blocks */ - ulong warm_blocks; /* number of blocks in warm sub-chain */ - ulong cnt_for_resize_op; /* counter to block resize operation */ - long blocks_available; /* number of blocks available in the LRU chain */ - HASH_LINK **hash_root; /* arr. of entries into hash table buckets */ - HASH_LINK *hash_link_root; /* memory for hash table links */ - HASH_LINK *free_hash_list; /* list of free hash links */ - BLOCK_LINK *free_block_list; /* list of free blocks */ - BLOCK_LINK *block_root; /* memory for block links */ - uchar HUGE_PTR *block_mem; /* memory for block buffers */ - BLOCK_LINK *used_last; /* ptr to the last block of the LRU chain */ - BLOCK_LINK *used_ins; /* ptr to the insertion block in LRU chain */ - pthread_mutex_t cache_lock; /* to lock access to the cache structure */ - KEYCACHE_WQUEUE resize_queue; /* threads waiting during resize operation */ - /* - Waiting for a zero resize count. Using a queue for symmetry though - only one thread can wait here. - */ - KEYCACHE_WQUEUE waiting_for_resize_cnt; - KEYCACHE_WQUEUE waiting_for_hash_link; /* waiting for a free hash link */ - KEYCACHE_WQUEUE waiting_for_block; /* requests waiting for a free block */ - BLOCK_LINK *changed_blocks[CHANGED_BLOCKS_HASH]; /* hash for dirty file bl.*/ - BLOCK_LINK *file_blocks[CHANGED_BLOCKS_HASH]; /* hash for other file bl.*/ - - /* - The following variables are and variables used to hold parameters for - initializing the key cache. - */ - - ulonglong param_buff_size; /* size the memory allocated for the cache */ - ulong param_block_size; /* size of the blocks in the key cache */ - ulong param_division_limit; /* min. percentage of warm blocks */ - ulong param_age_threshold; /* determines when hot block is downgraded */ - - /* Statistics variables. These are reset in reset_key_cache_counters(). */ - ulong global_blocks_changed; /* number of currently dirty blocks */ - ulonglong global_cache_w_requests;/* number of write requests (write hits) */ - ulonglong global_cache_write; /* number of writes from cache to files */ - ulonglong global_cache_r_requests;/* number of read requests (read hits) */ - ulonglong global_cache_read; /* number of reads from files to cache */ - - int blocks; /* max number of blocks in the cache */ - my_bool in_init; /* Set to 1 in MySQL during init/resize */ + my_bool in_init; /* Set to 1 in MySQL during init/resize */ + uint partitions; /* actual number of partitions */ + size_t key_cache_mem_size; /* specified size of the cache memory */ } KEY_CACHE; + /* The default key cache */ extern KEY_CACHE dflt_key_cache_var, *dflt_key_cache; extern int init_key_cache(KEY_CACHE *keycache, uint key_cache_block_size, size_t use_mem, uint division_limit, - uint age_threshold); + uint age_threshold, uint partitions); extern int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size, size_t use_mem, uint division_limit, uint age_threshold); @@ -122,12 +172,17 @@ extern int key_cache_insert(KEY_CACHE *keycache, File file, my_off_t filepos, int level, uchar *buff, uint length); extern int key_cache_write(KEY_CACHE *keycache, - File file, my_off_t filepos, int level, + File file, void *file_extra, + my_off_t filepos, int level, uchar *buff, uint length, - uint block_length,int force_write); + uint block_length, int force_write); extern int flush_key_blocks(KEY_CACHE *keycache, - int file, enum flush_type type); + int file, void *file_extra, + enum flush_type type); extern void end_key_cache(KEY_CACHE *keycache, my_bool cleanup); +extern void get_key_cache_statistics(KEY_CACHE *keycache, + uint partition_no, + KEY_CACHE_STATISTICS *key_cache_stats); /* Functions to handle multiple key caches */ extern my_bool multi_keycache_init(void); @@ -140,5 +195,11 @@ extern void multi_key_cache_change(KEY_CACHE *old_data, KEY_CACHE *new_data); extern int reset_key_cache_counters(const char *name, KEY_CACHE *key_cache); +extern int repartition_key_cache(KEY_CACHE *keycache, + uint key_cache_block_size, + size_t use_mem, + uint division_limit, + uint age_threshold, + uint partitions); C_MODE_END #endif /* _keycache_h */ |