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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:24:36 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:24:36 +0000
commit06eaf7232e9a920468c0f8d74dcf2fe8b555501c (patch)
treee2c7b5777f728320e5b5542b6213fd3591ba51e2 /storage/innobase/include/buf0rea.h
parentInitial commit. (diff)
downloadmariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.tar.xz
mariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.zip
Adding upstream version 1:10.11.6.upstream/1%10.11.6
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/*****************************************************************************
+
+Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2015, 2021, MariaDB Corporation.
+
+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 Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file include/buf0rea.h
+The database buffer read
+
+Created 11/5/1995 Heikki Tuuri
+*******************************************************/
+
+#ifndef buf0rea_h
+#define buf0rea_h
+
+#include "buf0buf.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.
+@param page_id page id
+@param zip_size ROW_FORMAT=COMPRESSED page size, or 0
+@retval DB_SUCCESS if the page was read and is not corrupted
+@retval DB_SUCCESS_LOCKED_REC if the page was not read
+@retval DB_PAGE_CORRUPTED if page based on checksum check is corrupted
+@retval DB_DECRYPTION_FAILED if page post encryption checksum matches but
+after decryption normal page checksum does not match.
+@retval DB_TABLESPACE_DELETED if tablespace .ibd file is missing */
+dberr_t buf_read_page(const page_id_t page_id, ulint zip_size);
+
+/** 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.
+@param[in,out] space tablespace
+@param[in] page_id page id
+@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0 */
+void buf_read_page_background(fil_space_t *space, const page_id_t page_id,
+ ulint zip_size)
+ MY_ATTRIBUTE((nonnull));
+
+/** Applies a random read-ahead in buf_pool if there are at least a threshold
+value of accessed pages from the random read-ahead area. Does not read any
+page, not even the one at the position (space, offset), if the read-ahead
+mechanism is not activated. NOTE 1: 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 2: 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 i/o.
+@param[in] page_id page id of a page which the current thread
+wants to access
+@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
+@param[in] ibuf whether we are inside ibuf routine
+@return number of page read requests issued; NOTE that if we read ibuf
+pages, it may happen that the page at the given page number does not
+get read even if we return a positive value! */
+ulint
+buf_read_ahead_random(const page_id_t page_id, ulint zip_size, bool ibuf);
+
+/** 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 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.
+@param[in] page_id page id; see NOTE 3 above
+@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
+@param[in] ibuf whether if we are inside ibuf routine
+@return number of page read requests issued */
+ulint
+buf_read_ahead_linear(const page_id_t page_id, ulint zip_size, bool ibuf);
+
+/** Schedule a page for recovery.
+@param space tablespace
+@param page_id page identifier
+@param recs log records
+@param init page initialization, or nullptr if the page needs to be read */
+void buf_read_recover(fil_space_t *space, const page_id_t page_id,
+ page_recv_t &recs, recv_init *init);
+
+/** @name Modes used in read-ahead @{ */
+/** read only pages belonging to the insert buffer tree */
+#define BUF_READ_IBUF_PAGES_ONLY 131
+/** read any page */
+#define BUF_READ_ANY_PAGE 132
+/* @} */
+
+#endif