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Diffstat (limited to 'include/keycache.h')
| -rw-r--r-- | include/keycache.h | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/include/keycache.h b/include/keycache.h new file mode 100644 index 00000000..14fd9c80 --- /dev/null +++ b/include/keycache.h @@ -0,0 +1,212 @@ +/* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* Key cache variable structures */ + +#ifndef _keycache_h +#define _keycache_h + +#include "my_sys.h" /* flush_type */ + +C_MODE_START + +/* + 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 +{ + 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, + uint changed_blocks_hash_size); +typedef + int (*RESIZE_KEY_CACHE) + (void *, uint key_cache_block_size, + size_t use_mem, uint division_limit, uint age_threshold, + uint changed_blocks_hash_size); +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); + +/* + 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 +{ + 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 */ + ulonglong param_block_size; /* size of the blocks in the key cache */ + ulonglong param_division_limit;/* min. percentage of warm blocks */ + ulonglong param_age_threshold; /* determines when hot block is downgraded */ + ulonglong param_partitions; /* number of the key cache partitions */ + ulonglong changed_blocks_hash_size; /* number of hash buckets for changed files */ + my_bool key_cache_inited; /* <=> key cache has been created */ + my_bool can_be_used; /* usage of cache for read/write is allowed */ + 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 */ + pthread_mutex_t op_lock; /* to serialize operations like '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 changed_blocks_hash_size, + 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, uint changed_blocks_hash_size); +extern void change_key_cache_param(KEY_CACHE *keycache, uint division_limit, + uint age_threshold); +extern uchar *key_cache_read(KEY_CACHE *keycache, + File file, my_off_t filepos, int level, + uchar *buff, uint length, + uint block_length,int return_buffer); +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, void *file_extra, + my_off_t filepos, int level, + uchar *buff, uint length, + uint block_length, int force_write); +extern int flush_key_blocks(KEY_CACHE *keycache, + 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); +extern void multi_keycache_free(void); +extern KEY_CACHE *multi_key_cache_search(uchar *key, uint length, + KEY_CACHE *def); +extern my_bool multi_key_cache_set(const uchar *key, uint length, + KEY_CACHE *key_cache); +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, void *); +extern int repartition_key_cache(KEY_CACHE *keycache, + uint key_cache_block_size, + size_t use_mem, + uint division_limit, + uint age_threshold, + uint changed_blocks_hash_size, + uint partitions); +C_MODE_END +#endif /* _keycache_h */ |