67
64
bool in_resize; /* true during resize operation */
68
65
bool resize_in_flush; /* true during flush of resize operation */
69
66
bool can_be_used; /* usage of cache for read/write is allowed */
70
uint32_t hash_entries; /* max number of entries in the hash table */
71
uint32_t key_cache_mem_size; /* specified size of the cache memory */
67
size_t key_cache_mem_size; /* specified size of the cache memory */
72
68
uint32_t key_cache_block_size; /* size of the page buffer of a cache block */
73
int disk_blocks; /* max number of blocks in the cache */
74
69
ulong min_warm_blocks; /* min number of warm blocks; */
75
70
ulong age_threshold; /* age threshold for hot blocks */
76
71
uint64_t keycache_time; /* total number of block link operations */
72
uint32_t hash_entries; /* max number of entries in the hash table */
77
73
int hash_links; /* max number of hash links */
78
74
int hash_links_used; /* number of hash links currently used */
75
int disk_blocks; /* max number of blocks in the cache */
79
76
ulong blocks_used; /* maximum number of concurrently used blocks */
80
77
ulong blocks_unused; /* number of currently unused blocks */
81
78
ulong blocks_changed; /* number of currently dirty blocks */
107
104
initializing the key cache.
110
uint32_t param_buff_size; /* size the memory allocated for the cache */
111
uint32_t param_block_size; /* size of the blocks in the key cache */
112
uint32_t param_division_limit; /* min. percentage of warm blocks */
113
uint32_t param_age_threshold; /* determines when hot block is downgraded */
107
uint64_t param_buff_size; /* size the memory allocated for the cache */
108
ulong param_block_size; /* size of the blocks in the key cache */
109
ulong param_division_limit; /* min. percentage of warm blocks */
110
ulong param_age_threshold; /* determines when hot block is downgraded */
115
int blocks; /* max number of blocks in the cache */
116
112
/* Statistics variables. These are reset in reset_key_cache_counters(). */
117
113
ulong global_blocks_changed; /* number of currently dirty blocks */
118
114
uint64_t global_cache_w_requests;/* number of write requests (write hits) */
120
116
uint64_t global_cache_r_requests;/* number of read requests (read hits) */
121
117
uint64_t global_cache_read; /* number of reads from files to cache */
119
int blocks; /* max number of blocks in the cache */
123
120
bool in_init; /* Set to 1 in MySQL during init/resize */
126
} /* namespace drizzled */
128
123
/* The default key cache */
129
extern drizzled::KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
124
extern KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
131
extern int init_key_cache(drizzled::KEY_CACHE *keycache, uint32_t key_cache_block_size,
126
extern int init_key_cache(KEY_CACHE *keycache, uint32_t key_cache_block_size,
132
127
size_t use_mem, uint32_t division_limit,
133
128
uint32_t age_threshold);
134
extern int resize_key_cache(drizzled::KEY_CACHE *keycache, uint32_t key_cache_block_size,
129
extern int resize_key_cache(KEY_CACHE *keycache, uint32_t key_cache_block_size,
135
130
size_t use_mem, uint32_t division_limit,
136
131
uint32_t age_threshold);
137
extern unsigned char *key_cache_read(drizzled::KEY_CACHE *keycache,
138
int file, drizzled::internal::my_off_t filepos, int level,
132
extern void change_key_cache_param(KEY_CACHE *keycache, uint32_t division_limit,
133
uint32_t age_threshold);
134
extern unsigned char *key_cache_read(KEY_CACHE *keycache,
135
File file, my_off_t filepos, int level,
139
136
unsigned char *buff, uint32_t length,
140
137
uint32_t block_length,int return_buffer);
141
extern int key_cache_insert(drizzled::KEY_CACHE *keycache,
142
int file, drizzled::internal::my_off_t filepos, int level,
138
extern int key_cache_insert(KEY_CACHE *keycache,
139
File file, my_off_t filepos, int level,
143
140
unsigned char *buff, uint32_t length);
144
extern int key_cache_write(drizzled::KEY_CACHE *keycache,
145
int file, drizzled::internal::my_off_t filepos, int level,
141
extern int key_cache_write(KEY_CACHE *keycache,
142
File file, my_off_t filepos, int level,
146
143
unsigned char *buff, uint32_t length,
147
144
uint32_t block_length,int force_write);
148
extern int flush_key_blocks(drizzled::KEY_CACHE *keycache,
145
extern int flush_key_blocks(KEY_CACHE *keycache,
149
146
int file, enum flush_type type);
150
extern void end_key_cache(drizzled::KEY_CACHE *keycache, bool cleanup);
152
extern void reset_key_cache_counters();
155
Next highest power of two
158
my_round_up_to_next_power()
162
Next or equal power of 2
163
Note: 0 will return 0
166
Algorithm by Sean Anderson, according to:
167
http://graphics.stanford.edu/~seander/bithacks.html
168
(Orignal code public domain)
170
Comments shows how this works with 01100000000000000000000000001011
173
static inline uint32_t my_round_up_to_next_power(uint32_t v)
175
v--; /* 01100000000000000000000000001010 */
176
v|= v >> 1; /* 01110000000000000000000000001111 */
177
v|= v >> 2; /* 01111100000000000000000000001111 */
178
v|= v >> 4; /* 01111111110000000000000000001111 */
179
v|= v >> 8; /* 01111111111111111100000000001111 */
180
v|= v >> 16; /* 01111111111111111111111111111111 */
181
return v+1; /* 10000000000000000000000000000000 */
147
extern void end_key_cache(KEY_CACHE *keycache, bool cleanup);
149
/* Functions to handle multiple key caches */
150
extern bool multi_keycache_init(void);
151
extern void multi_keycache_free(void);
152
extern KEY_CACHE *multi_key_cache_search(unsigned char *key, uint32_t length);
153
extern bool multi_key_cache_set(const unsigned char *key, uint32_t length,
154
KEY_CACHE *key_cache);
155
extern void multi_key_cache_change(KEY_CACHE *old_data,
156
KEY_CACHE *new_data);
157
extern int reset_key_cache_counters(const char *name,
158
KEY_CACHE *key_cache);
185
#endif /* PLUGIN_MYISAM_KEYCACHE_H */
164
#endif /* _keycache_h */