Drizzled Public API Documentation

buf_block_struct Struct Reference

#include <buf0buf.h>

List of all members.

Public Attributes

Optimistic search field
ib_uint64_t modify_clock
Hash search fields (unprotected)

NOTE that these fields are NOT protected by any semaphore!

ulint n_hash_helps
ulint n_fields
ulint n_bytes
ibool left_side
Hash search fields

These 6 fields may only be modified when we have an x-latch on btr_search_latch AND

  • we are holding an s-latch or x-latch on buf_block_struct::lock or
  • we know that buf_block_struct::buf_fix_count == 0.

An exception to this is when we init or create a page in the buffer pool in buf0buf.c.

unsigned is_hashed:1
unsigned curr_n_fields:10
unsigned curr_n_bytes:15
unsigned curr_left_side:1
dict_index_tindex

General fields

buf_page_t page
byte * frame
mutex_t mutex
rw_lock_t lock
unsigned lock_hash_val:32
ibool check_index_page_at_flush
 UT_LIST_NODE_T (buf_block_t) unzip_LRU

Detailed Description

The buffer control block structure

Definition at line 1343 of file buf0buf.h.


Member Function Documentation

node of the decompressed LRU list; a block is in the unzip_LRU list if page.state == BUF_BLOCK_FILE_PAGE and page.zip.data != NULL


Member Data Documentation

TRUE if we know that this is an index page, and want the database to check its consistency before flush; note that there may be pages in the buffer pool which are index pages, but this flag is not set because we do not keep track of all pages; NOT protected by any mutex

Definition at line 1383 of file buf0buf.h.

Referenced by btr_create(), btr_cur_open_at_index_side_func(), btr_cur_search_to_nth_level(), btr_pcur_move_to_next_page(), buf_reset_check_index_page_at_flush(), and page_zip_reorganize().

TRUE if hash index has already been built on this page; note that it does not guarantee that the index is complete, though: there may have been hash collisions, record deletions, etc.

Definition at line 1439 of file buf0buf.h.

Referenced by btr_cur_del_mark_set_clust_rec(), btr_cur_del_mark_set_sec_rec(), btr_cur_update_in_place(), btr_search_drop_page_hash_index(), btr_search_move_or_delete_hash_entries(), btr_search_update_hash_node_on_insert(), btr_search_update_hash_on_delete(), btr_search_update_hash_on_insert(), buf_page_peek_if_search_hashed(), and page_set_max_trx_id().

TRUE or FALSE, depending on whether the leftmost record of several records with the same prefix should be indexed in the hash index

Definition at line 1417 of file buf0buf.h.

Referenced by btr_search_move_or_delete_hash_entries().

hashed value of the page address in the record lock hash table; protected by buf_block_t::lock (or buf_block_t::mutex, buf_pool->mutex in buf_page_get_gen(), buf_page_init_for_read() and buf_page_create())

Definition at line 1375 of file buf0buf.h.

Referenced by buf_page_get_gen().

this clock is incremented every time a pointer to a record on the page may become obsolete; this is used in the optimistic cursor positioning: if the modify clock has not changed, we know that the pointer is still valid; this field may be changed if the thread (1) owns the pool mutex and the page is not bufferfixed, or (2) the thread has an x-latch on the block

Definition at line 1395 of file buf0buf.h.

Referenced by buf_page_optimistic_get().

mutex protecting this block: state (also protected by the buffer pool mutex), io_fix, buf_fix_count, and accessed; we introduce this new mutex in InnoDB-5.1 to relieve contention on the buffer pool mutex

Definition at line 1367 of file buf0buf.h.

Referenced by buf_LRU_block_free_non_file_page(), buf_LRU_get_free_only(), buf_page_create(), buf_page_get_gen(), buf_page_get_known_nowait(), buf_page_init_for_read(), buf_page_optimistic_get(), and buf_page_try_get_func().

recommended prefix: number of bytes in an incomplete field

Definition at line 1415 of file buf0buf.h.

Referenced by btr_search_move_or_delete_hash_entries().

recommended prefix length for hash search: number of full fields

Definition at line 1413 of file buf0buf.h.

Referenced by btr_search_move_or_delete_hash_entries().

counter which controls building of a new hash index for the page

Definition at line 1411 of file buf0buf.h.


The documentation for this struct was generated from the following file: