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bool in_init; /* Set to 1 in MySQL during init/resize */
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} /* namespace drizzled */
123
128
/* The default key cache */
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extern KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
129
extern drizzled::KEY_CACHE dflt_key_cache_var, *dflt_key_cache;
126
extern int init_key_cache(KEY_CACHE *keycache, uint32_t key_cache_block_size,
127
uint32_t use_mem, uint32_t division_limit,
131
extern int init_key_cache(drizzled::KEY_CACHE *keycache, uint32_t key_cache_block_size,
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size_t use_mem, uint32_t division_limit,
128
133
uint32_t age_threshold);
129
extern int resize_key_cache(KEY_CACHE *keycache, uint32_t key_cache_block_size,
130
uint32_t use_mem, uint32_t division_limit,
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,
131
136
uint32_t age_threshold);
132
extern unsigned char *key_cache_read(KEY_CACHE *keycache,
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int file, my_off_t filepos, int level,
137
extern unsigned char *key_cache_read(drizzled::KEY_CACHE *keycache,
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int file, drizzled::internal::my_off_t filepos, int level,
134
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unsigned char *buff, uint32_t length,
135
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uint32_t block_length,int return_buffer);
136
extern int key_cache_insert(KEY_CACHE *keycache,
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int file, my_off_t filepos, int level,
141
extern int key_cache_insert(drizzled::KEY_CACHE *keycache,
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int file, drizzled::internal::my_off_t filepos, int level,
138
143
unsigned char *buff, uint32_t length);
139
extern int key_cache_write(KEY_CACHE *keycache,
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int file, my_off_t filepos, int level,
144
extern int key_cache_write(drizzled::KEY_CACHE *keycache,
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int file, drizzled::internal::my_off_t filepos, int level,
141
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unsigned char *buff, uint32_t length,
142
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uint32_t block_length,int force_write);
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extern int flush_key_blocks(KEY_CACHE *keycache,
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extern int flush_key_blocks(drizzled::KEY_CACHE *keycache,
144
149
int file, enum flush_type type);
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extern void end_key_cache(KEY_CACHE *keycache, bool cleanup);
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extern void end_key_cache(drizzled::KEY_CACHE *keycache, bool cleanup);
147
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extern void reset_key_cache_counters();
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Next highest power of two
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my_round_up_to_next_power()
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Next or equal power of 2
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Note: 0 will return 0
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Algorithm by Sean Anderson, according to:
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http://graphics.stanford.edu/~seander/bithacks.html
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(Orignal code public domain)
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Comments shows how this works with 01100000000000000000000000001011
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static inline uint32_t my_round_up_to_next_power(uint32_t v)
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v--; /* 01100000000000000000000000001010 */
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v|= v >> 1; /* 01110000000000000000000000001111 */
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v|= v >> 2; /* 01111100000000000000000000001111 */
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v|= v >> 4; /* 01111111110000000000000000001111 */
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v|= v >> 8; /* 01111111111111111100000000001111 */
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v|= v >> 16; /* 01111111111111111111111111111111 */
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return v+1; /* 10000000000000000000000000000000 */
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185
#endif /* PLUGIN_MYISAM_KEYCACHE_H */