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Diffstat (limited to 'innobase/include/buf0rea.h')
| -rw-r--r-- | innobase/include/buf0rea.h | 103 |
1 files changed, 0 insertions, 103 deletions
diff --git a/innobase/include/buf0rea.h b/innobase/include/buf0rea.h deleted file mode 100644 index 380a42f4b80..00000000000 --- a/innobase/include/buf0rea.h +++ /dev/null @@ -1,103 +0,0 @@ -/****************************************************** -The database buffer read - -(c) 1995 Innobase Oy - -Created 11/5/1995 Heikki Tuuri -*******************************************************/ - -#ifndef buf0rea_h -#define buf0rea_h - -#include "univ.i" -#include "buf0types.h" - -/************************************************************************ -High-level function which reads a page asynchronously from a file to the -buffer buf_pool if it is not already there. Sets the io_fix flag and sets -an exclusive lock on the buffer frame. The flag is cleared and the x-lock -released by the i/o-handler thread. Does a random read-ahead if it seems -sensible. */ - -ulint -buf_read_page( -/*==========*/ - /* out: number of page read requests issued: this can - be > 1 if read-ahead occurred */ - ulint space, /* in: space id */ - ulint offset);/* in: page number */ -/************************************************************************ -Applies linear read-ahead if in the buf_pool the page is a border page of -a linear read-ahead area and all the pages in the area have been accessed. -Does not read any page if the read-ahead mechanism is not activated. Note -that the the algorithm looks at the 'natural' adjacent successor and -predecessor of the page, which on the leaf level of a B-tree are the next -and previous page in the chain of leaves. To know these, the page specified -in (space, offset) must already be present in the buf_pool. Thus, the -natural way to use this function is to call it when a page in the buf_pool -is accessed the first time, calling this function just after it has been -bufferfixed. -NOTE 1: as this function looks at the natural predecessor and successor -fields on the page, what happens, if these are not initialized to any -sensible value? No problem, before applying read-ahead we check that the -area to read is within the span of the space, if not, read-ahead is not -applied. An uninitialized value may result in a useless read operation, but -only very improbably. -NOTE 2: the calling thread may own latches on pages: to avoid deadlocks this -function must be written such that it cannot end up waiting for these -latches! -NOTE 3: the calling thread must want access to the page given: this rule is -set to prevent unintended read-aheads performed by ibuf routines, a situation -which could result in a deadlock if the OS does not support asynchronous io. */ - -ulint -buf_read_ahead_linear( -/*==================*/ - /* out: number of page read requests issued */ - ulint space, /* in: space id */ - ulint offset);/* in: page number of a page; NOTE: the current thread - must want access to this page (see NOTE 3 above) */ -/************************************************************************ -Issues read requests for pages which the ibuf module wants to read in, in -order to contract the insert buffer tree. Technically, this function is like -a read-ahead function. */ - -void -buf_read_ibuf_merge_pages( -/*======================*/ - ibool sync, /* in: TRUE if the caller wants this function - to wait for the highest address page to get - read in, before this function returns */ - ulint* space_ids, /* in: array of space ids */ - ib_longlong* space_versions,/* in: the spaces must have this version - number (timestamp), otherwise we discard the - read; we use this to cancel reads if - DISCARD + IMPORT may have changed the - tablespace size */ - ulint* page_nos, /* in: array of page numbers to read, with the - highest page number the last in the array */ - ulint n_stored); /* in: number of page numbers in the array */ -/************************************************************************ -Issues read requests for pages which recovery wants to read in. */ - -void -buf_read_recv_pages( -/*================*/ - ibool sync, /* in: TRUE if the caller wants this function - to wait for the highest address page to get - read in, before this function returns */ - ulint space, /* in: space id */ - ulint* page_nos, /* in: array of page numbers to read, with the - highest page number the last in the array */ - ulint n_stored); /* in: number of page numbers in the array */ - -/* The size in pages of the area which the read-ahead algorithms read if -invoked */ - -#define BUF_READ_AHEAD_AREA ut_min(64, ut_2_power_up(buf_pool->curr_size / 32)) - -/* Modes used in read-ahead */ -#define BUF_READ_IBUF_PAGES_ONLY 131 -#define BUF_READ_ANY_PAGE 132 - -#endif |