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Diffstat (limited to 'include/pagecache.h')
| -rw-r--r-- | include/pagecache.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/include/pagecache.h b/include/pagecache.h new file mode 100644 index 00000000000..32e23fb54ea --- /dev/null +++ b/include/pagecache.h @@ -0,0 +1,228 @@ +/* Copyright (C) 2006 MySQL AB + + 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; either version 2 of the License, or + (at your option) any later version. + + 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +/* Page cache variable structures */ + +#ifndef _pagecache_h +#define _pagecache_h +C_MODE_START + +#include "../storage/maria/ma_loghandler_lsn.h" +#include <m_string.h> + +/* Type of the page */ +enum pagecache_page_type +{ +#ifndef DBUG_OFF + /* used only for control page type changing during debugging */ + PAGECACHE_EMPTY_PAGE, +#endif + /* the page does not contain LSN */ + PAGECACHE_PLAIN_PAGE, + /* the page contain LSN (maria tablespace page) */ + PAGECACHE_LSN_PAGE +}; + +/* + This enum describe lock status changing. every type of page cache will + interpret WRITE/READ lock as it need. +*/ +enum pagecache_page_lock +{ + PAGECACHE_LOCK_LEFT_UNLOCKED, /* free -> free */ + PAGECACHE_LOCK_LEFT_READLOCKED, /* read -> read */ + PAGECACHE_LOCK_LEFT_WRITELOCKED, /* write -> write */ + PAGECACHE_LOCK_READ, /* free -> read */ + PAGECACHE_LOCK_WRITE, /* free -> write */ + PAGECACHE_LOCK_READ_UNLOCK, /* read -> free */ + PAGECACHE_LOCK_WRITE_UNLOCK, /* write -> free */ + PAGECACHE_LOCK_WRITE_TO_READ /* write -> read */ +}; +/* + This enum describe pin status changing +*/ +enum pagecache_page_pin +{ + PAGECACHE_PIN_LEFT_PINNED, /* pinned -> pinned */ + PAGECACHE_PIN_LEFT_UNPINNED, /* unpinned -> unpinned */ + PAGECACHE_PIN, /* unpinned -> pinned */ + PAGECACHE_UNPIN /* pinned -> unpinned */ +}; +/* How to write the page */ +enum pagecache_write_mode +{ + /* do not write immediately, i.e. it will be dirty page */ + PAGECACHE_WRITE_DELAY, + /* write page to the file and put it to the cache */ + PAGECACHE_WRITE_NOW, + /* page already is in the file. (key cache insert analogue) */ + PAGECACHE_WRITE_DONE +}; + +typedef void *PAGECACHE_PAGE_LINK; + +/* file descriptor for Maria */ +typedef struct st_pagecache_file +{ + int file; /* it is for debugging purposes then it will be uint32 file_no */ +} PAGECACHE_FILE; + +/* page number for maria */ +typedef uint32 pgcache_page_no_t; + +/* declare structures that is used by st_pagecache */ + +struct st_pagecache_block_link; +typedef struct st_pagecache_block_link PAGECACHE_BLOCK_LINK; +struct st_pagecache_page; +typedef struct st_pagecache_page PAGECACHE_PAGE; +struct st_pagecache_hash_link; +typedef struct st_pagecache_hash_link PAGECACHE_HASH_LINK; + +#include <wqueue.h> + +typedef my_bool (*pagecache_disk_read_validator)(byte *page, gptr data); + +#define PAGECACHE_CHANGED_BLOCKS_HASH 128 /* must be power of 2 */ + +/* + The page cache structure + It also contains read-only statistics parameters. +*/ + +typedef struct st_pagecache +{ + my_bool inited; + my_bool resize_in_flush; /* true during flush of resize operation */ + my_bool can_be_used; /* usage of cache for read/write is allowed */ + uint shift; /* block size = 2 ^ shift */ + my_size_t mem_size; /* specified size of the cache memory */ + uint32 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 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 taken from free links pool */ + 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 */ + ulong blocks_available; /* number of blocks available in the LRU chain */ + PAGECACHE_HASH_LINK **hash_root;/* arr. of entries into hash table buckets */ + PAGECACHE_HASH_LINK *hash_link_root;/* memory for hash table links */ + PAGECACHE_HASH_LINK *free_hash_list;/* list of free hash links */ + PAGECACHE_BLOCK_LINK *free_block_list;/* list of free blocks */ + PAGECACHE_BLOCK_LINK *block_root;/* memory for block links */ + byte HUGE_PTR *block_mem; /* memory for block buffers */ + PAGECACHE_BLOCK_LINK *used_last;/* ptr to the last block of the LRU chain */ + PAGECACHE_BLOCK_LINK *used_ins;/* ptr to the insertion block in LRU chain */ + pthread_mutex_t cache_lock; /* to lock access to the cache structure */ + WQUEUE resize_queue; /* threads waiting during resize operation */ + WQUEUE waiting_for_hash_link;/* waiting for a free hash link */ + WQUEUE waiting_for_block; /* requests waiting for a free block */ + /* hash for dirty file bl.*/ + PAGECACHE_BLOCK_LINK *changed_blocks[PAGECACHE_CHANGED_BLOCKS_HASH]; + /* hash for other file bl.*/ + PAGECACHE_BLOCK_LINK *file_blocks[PAGECACHE_CHANGED_BLOCKS_HASH]; + + /* + 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_pagecache_counters(). */ + 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 */ +} PAGECACHE; + +extern int init_pagecache(PAGECACHE *pagecache, my_size_t use_mem, + uint division_limit, uint age_threshold, + uint block_size); +extern int resize_pagecache(PAGECACHE *pagecache, + my_size_t use_mem, uint division_limit, + uint age_threshold); +extern void change_pagecache_param(PAGECACHE *pagecache, uint division_limit, + uint age_threshold); + +#define pagecache_read(P,F,N,L,B,T,K,I) \ + pagecache_valid_read(P,F,N,L,B,T,K,I,0,0) + +extern byte *pagecache_valid_read(PAGECACHE *pagecache, + PAGECACHE_FILE *file, + pgcache_page_no_t pageno, + uint level, + byte *buff, + enum pagecache_page_type type, + enum pagecache_page_lock lock, + PAGECACHE_PAGE_LINK *link, + pagecache_disk_read_validator validator, + gptr validator_data); +extern my_bool pagecache_write(PAGECACHE *pagecache, + PAGECACHE_FILE *file, + pgcache_page_no_t pageno, + uint level, + byte *buff, + enum pagecache_page_type type, + enum pagecache_page_lock lock, + enum pagecache_page_pin pin, + enum pagecache_write_mode write_mode, + PAGECACHE_PAGE_LINK *link); +extern void pagecache_unlock_page(PAGECACHE *pagecache, + PAGECACHE_FILE *file, + pgcache_page_no_t pageno, + enum pagecache_page_lock lock, + enum pagecache_page_pin pin, + LSN first_REDO_LSN_for_page); +extern void pagecache_unlock(PAGECACHE *pagecache, + PAGECACHE_PAGE_LINK *link, + enum pagecache_page_lock lock, + enum pagecache_page_pin pin, + LSN first_REDO_LSN_for_page); +extern void pagecache_unpin_page(PAGECACHE *pagecache, + PAGECACHE_FILE *file, + pgcache_page_no_t pageno); +extern void pagecache_unpin(PAGECACHE *pagecache, + PAGECACHE_PAGE_LINK *link); +extern int flush_pagecache_blocks(PAGECACHE *keycache, + PAGECACHE_FILE *file, + enum flush_type type); +extern my_bool pagecache_delete_page(PAGECACHE *pagecache, + PAGECACHE_FILE *file, + pgcache_page_no_t pageno, + enum pagecache_page_lock lock, + my_bool flush); +extern void end_pagecache(PAGECACHE *keycache, my_bool cleanup); +extern my_bool pagecache_collect_changed_blocks_with_lsn(PAGECACHE *pagecache, + LEX_STRING *str, + LSN *max_lsn); +extern int reset_pagecache_counters(const char *name, PAGECACHE *pagecache); + +C_MODE_END +#endif /* _keycache_h */ |