62
67
bool in_resize; /* true during resize operation */
63
68
bool resize_in_flush; /* true during flush of resize operation */
64
69
bool can_be_used; /* usage of cache for read/write is allowed */
65
size_t key_cache_mem_size; /* specified size of the cache memory */
66
uint key_cache_block_size; /* size of the page buffer of a cache block */
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 */
72
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 */
67
74
ulong min_warm_blocks; /* min number of warm blocks; */
68
75
ulong age_threshold; /* age threshold for hot blocks */
69
76
uint64_t keycache_time; /* total number of block link operations */
70
uint hash_entries; /* max number of entries in the hash table */
71
77
int hash_links; /* max number of hash links */
72
78
int hash_links_used; /* number of hash links currently used */
73
int disk_blocks; /* max number of blocks in the cache */
74
79
ulong blocks_used; /* maximum number of concurrently used blocks */
75
80
ulong blocks_unused; /* number of currently unused blocks */
76
81
ulong blocks_changed; /* number of currently dirty blocks */
114
120
uint64_t global_cache_r_requests;/* number of read requests (read hits) */
115
121
uint64_t global_cache_read; /* number of reads from files to cache */
117
int blocks; /* max number of blocks in the cache */
118
123
bool in_init; /* Set to 1 in MySQL during init/resize */
126
} /* namespace drizzled */
121
128
/* The default key cache */
122
extern KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
129
extern drizzled::KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
124
extern int init_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
125
size_t use_mem, uint division_limit,
127
extern int resize_key_cache(KEY_CACHE *keycache, uint key_cache_block_size,
128
size_t use_mem, uint division_limit,
130
extern void change_key_cache_param(KEY_CACHE *keycache, uint division_limit,
132
extern uchar *key_cache_read(KEY_CACHE *keycache,
133
File file, my_off_t filepos, int level,
134
uchar *buff, uint length,
135
uint block_length,int return_buffer);
136
extern int key_cache_insert(KEY_CACHE *keycache,
137
File file, my_off_t filepos, int level,
138
uchar *buff, uint length);
139
extern int key_cache_write(KEY_CACHE *keycache,
140
File file, my_off_t filepos, int level,
141
uchar *buff, uint length,
142
uint block_length,int force_write);
143
extern int flush_key_blocks(KEY_CACHE *keycache,
131
extern int init_key_cache(drizzled::KEY_CACHE *keycache, uint32_t key_cache_block_size,
132
size_t use_mem, uint32_t division_limit,
133
uint32_t age_threshold);
134
extern int resize_key_cache(drizzled::KEY_CACHE *keycache, uint32_t key_cache_block_size,
135
size_t use_mem, uint32_t division_limit,
136
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,
139
unsigned char *buff, uint32_t length,
140
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,
143
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,
146
unsigned char *buff, uint32_t length,
147
uint32_t block_length,int force_write);
148
extern int flush_key_blocks(drizzled::KEY_CACHE *keycache,
144
149
int file, enum flush_type type);
145
extern void end_key_cache(KEY_CACHE *keycache, bool cleanup);
147
/* Functions to handle multiple key caches */
148
extern bool multi_keycache_init(void);
149
extern void multi_keycache_free(void);
150
extern KEY_CACHE *multi_key_cache_search(uchar *key, uint length);
151
extern bool multi_key_cache_set(const uchar *key, uint length,
152
KEY_CACHE *key_cache);
153
extern void multi_key_cache_change(KEY_CACHE *old_data,
154
KEY_CACHE *new_data);
155
extern int reset_key_cache_counters(const char *name,
156
KEY_CACHE *key_cache);
158
#endif /* _keycache_h */
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 */
185
#endif /* PLUGIN_MYISAM_KEYCACHE_H */