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WL#86: Partitioned key cache for MyISAM.

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This is the base patch for the task.
This commit is contained in:
Igor Babaev
2010-02-16 08:41:11 -08:00
parent abb87914ec
commit 7e4d89c973
33 changed files with 8063 additions and 325 deletions
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179
include/keycache.h
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@@ -19,96 +19,121 @@
#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
/*
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 MAX_KEY_CACHE_PARTITIONS 64
/* The structure to get statistical data about a key cache */
typedef struct st_key_cache_statistics
{
struct st_my_thread_var *last_thread; /* circular list of waiting threads */
} KEYCACHE_WQUEUE;
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 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;
/* The type of a key cache object */
typedef enum key_cache_type
{
SIMPLE_KEY_CACHE,
PARTITIONED_KEY_CACHE
} KEY_CACHE_TYPE;
#define CHANGED_BLOCKS_HASH 128 /* must be power of 2 */
/*
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
{
int (*init) (void *, uint key_cache_block_size,
size_t use_mem, uint division_limit, uint age_threshold);
int (*resize) (void *, uint key_cache_block_size,
size_t use_mem, uint division_limit, uint age_threshold);
void (*change_param) (void *keycache_cb,
uint division_limit, uint age_threshold);
uchar* (*read) (void *keycache_cb,
File file, my_off_t filepos, int level,
uchar *buff, uint length,
uint block_length, int return_buffer);
int (*insert) (void *keycache_cb,
File file, my_off_t filepos, int level,
uchar *buff, uint length);
int (*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);
int (*flush) (void *keycache_cb,
int file, void *file_extra,
enum flush_type type);
int (*reset_counters) (const char *name, void *keycache_cb);
void (*end) (void *keycache_cb, my_bool cleanup);
void (*get_stats) (void *keycache_cb, uint partition_no,
KEY_CACHE_STATISTICS *key_cache_stats);
ulonglong (*get_stat_val) (void *keycache_cb, uint var_no);
} 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 */
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 */
ulong blocks_used; /* maximum number of concurrently used blocks */
ulong blocks_unused; /* number of currently unused blocks */
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 */
} 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 +147,18 @@ 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);
extern ulonglong get_key_cache_stat_value(KEY_CACHE *keycache, uint var_no);
/* Functions to handle multiple key caches */
extern my_bool multi_keycache_init(void);
@@ -140,5 +171,11 @@ 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 */