MySQL 8.0.30
Source Code Documentation
dblwr Namespace Reference

Namespaces

namespace  recv
 
namespace  v1
 

Classes

struct  Buffer
 IO buffer in UNIV_PAGE_SIZE units and aligned on UNIV_PAGE_SIZE. More...
 
struct  File
 
struct  Mode
 
struct  Reduced_entry
 When –innodb-doublewrite=DETECT_ONLY, page contents are not written to the dblwr buffer. More...
 

Functions

bool is_odd (uint32_t val)
 
std::ostream & operator<< (std::ostream &out, const File &obj) noexcept
 Overload the global output operator to work with dblwr::File type. More...
 
static bool is_encrypted_page (const byte *page) noexcept
 
bool has_encrypted_pages () noexcept
 Check if the dblwr files contain encrypted pages. More...
 
dberr_t open () noexcept
 Startup the background thread(s) and create the instance. More...
 
dberr_t enable_reduced () noexcept
 Enable the doublewrite reduced mode by creating the necessary dblwr files and in-memory structures. More...
 
dberr_t reduced_open () noexcept
 Check and open the reduced doublewrite files if necessary. More...
 
void close () noexcept
 Shutdown the background thread and destroy the instance. More...
 
void force_flush (buf_flush_t flush_type, uint32_t buf_pool_index) noexcept
 Force a write of all pages in the queue. More...
 
void force_flush_all () noexcept
 Force a write of all pages in all dblwr segments (reduced or regular) This is used only when switching the doublewrite mode dynamically. More...
 
dberr_t write (buf_flush_t flush_type, buf_page_t *bpage, bool sync) noexcept
 Writes a page to the doublewrite buffer on disk, syncs it, then writes the page to the datafile. More...
 
file::Blockget_encrypted_frame (buf_page_t *bpage) noexcept
 Obtain the encrypted frame and store it in bpage->m_io_frame. More...
 
void write_complete (buf_page_t *bpage, buf_flush_t flush_type) noexcept
 Updates the double write buffer when a write request is completed. More...
 
void reset_files () noexcept
 Delete or adjust the dblwr file size if required. More...
 
bool is_enabled ()
 Check if doublewrite is enabled. More...
 
bool is_reduced ()
 Check if the doublewrite mode is detect-only (aka reduced). More...
 
bool is_disabled ()
 Check if the doublewrite mode is disabled. More...
 
const char * to_string (ulong mode)
 
void set ()
 Toggle the doublewrite buffer. More...
 

Variables

std::string dir {"."}
 Double write files location. More...
 
ulong n_files {1}
 Number of files to use for the double write buffer. More...
 
ulong batch_size {}
 Maximum number of pages to write in one batch. More...
 
ulong n_pages {64}
 Number of pages per doublewrite thread/segment. More...
 
ulong g_mode {Mode::ON}
 DBLWR mode. More...
 
bool is_reduced_inited = false
 true if DETECT_ONLY (aka reduced) mode is inited More...
 
static page_no_t LEGACY_PAGE1
 Legacy dblwr buffer first segment page number. More...
 
static page_no_t LEGACY_PAGE2
 Legacy dblwr buffer second segment page number. More...
 
page_id_t Force_crash {UINT32_UNDEFINED, UINT32_UNDEFINED}
 Crash the server after writing this page to the data file. More...
 
const uint32_t REDUCED_BATCH_PAGE_SIZE = 8192
 
const uint32_t RB_BATCH_ID_SIZE = 4
 
const uint32_t RB_CHECKSUM_SIZE = 4
 
const uint32_t RB_DATA_LEN_SIZE = 2
 
const uint32_t RB_BATCH_TYPE_SIZE = 1
 
const uint32_t RB_UNUSED_BYTES_SIZE = 9
 
constexpr const uint32_t RB_OFF_BATCH_ID = 0
 
constexpr const uint32_t RB_OFF_CHECKSUM = RB_OFF_BATCH_ID + RB_BATCH_ID_SIZE
 
constexpr const uint32_t RB_OFF_DATA_LEN = RB_OFF_CHECKSUM + RB_CHECKSUM_SIZE
 
constexpr const uint32_t RB_OFF_BATCH_TYPE = RB_OFF_DATA_LEN + RB_DATA_LEN_SIZE
 
constexpr const uint32_t RB_OFF_UNUSED = RB_OFF_BATCH_TYPE + RB_BATCH_TYPE_SIZE
 
constexpr const uint32_t REDUCED_HEADER_SIZE
 
constexpr const uint32_t REDUCED_ENTRY_SIZE
 
constexpr const uint32_t REDUCED_DATA_SIZE
 
constexpr const uint32_t REDUCED_MAX_ENTRIES
 

Function Documentation

◆ close()

void dblwr::close ( )
noexcept

Shutdown the background thread and destroy the instance.

◆ enable_reduced()

dberr_t dblwr::enable_reduced ( )
noexcept

Enable the doublewrite reduced mode by creating the necessary dblwr files and in-memory structures.

Returns
DB_SUCCESS or error code

◆ force_flush()

void dblwr::force_flush ( buf_flush_t  flush_type,
uint32_t  buf_pool_index 
)
noexcept

Force a write of all pages in the queue.

Parameters
[in]flush_typeFLUSH LIST or LRU_LIST flush request.
[in]buf_pool_indexBuffer pool instance for which called.

◆ force_flush_all()

void dblwr::force_flush_all ( )
noexcept

Force a write of all pages in all dblwr segments (reduced or regular) This is used only when switching the doublewrite mode dynamically.

◆ get_encrypted_frame()

file::Block * dblwr::get_encrypted_frame ( buf_page_t bpage)
noexcept

Obtain the encrypted frame and store it in bpage->m_io_frame.

Parameters
[in,out]bpagethe buffer page containing the unencrypted frame.
Returns
the memory block containing the compressed + encrypted frame.

◆ has_encrypted_pages()

bool dblwr::has_encrypted_pages ( )
noexcept

Check if the dblwr files contain encrypted pages.

Returns
true if dblwr file contains any encrypted pages, false if dblwr file contains no encrypted pages.

◆ is_disabled()

bool dblwr::is_disabled ( )
inline

Check if the doublewrite mode is disabled.

Returns
true if dblwr mode is OFF.

◆ is_enabled()

bool dblwr::is_enabled ( )
inline

Check if doublewrite is enabled.

Returns
true if dblwr mode is ON, DETECT_ONLY, DETECT_AND_RECOVER
false if dblwr mode is OFF.

◆ is_encrypted_page()

static bool dblwr::is_encrypted_page ( const byte page)
staticnoexcept

◆ is_odd()

bool dblwr::is_odd ( uint32_t  val)
inline

◆ is_reduced()

bool dblwr::is_reduced ( )
inline

Check if the doublewrite mode is detect-only (aka reduced).

Returns
true if dblwr mode is DETECT_ONLY.

◆ open()

dberr_t dblwr::open ( )
noexcept

Startup the background thread(s) and create the instance.

Returns
DB_SUCCESS or error code

◆ operator<<()

std::ostream & dblwr::operator<< ( std::ostream &  out,
const File obj 
)
inlinenoexcept

Overload the global output operator to work with dblwr::File type.

Parameters
[in]outoutput stream into which the object is printed.
[in]objAn object to type dblwr::File.
Returns
the output stream.

◆ reduced_open()

dberr_t dblwr::reduced_open ( )
noexcept

Check and open the reduced doublewrite files if necessary.

Returns
DB_SUCCESS or error code

◆ reset_files()

void dblwr::reset_files ( )
noexcept

Delete or adjust the dblwr file size if required.

◆ set()

void dblwr::set ( )

Toggle the doublewrite buffer.

◆ to_string()

const char * dblwr::to_string ( ulong  mode)
Returns
string version of dblwr numeric values
Parameters
[in]modedblwr ENUM

◆ write()

dberr_t dblwr::write ( buf_flush_t  flush_type,
buf_page_t bpage,
bool  sync 
)
noexcept

Writes a page to the doublewrite buffer on disk, syncs it, then writes the page to the datafile.

Parameters
[in]flush_typeFlush type
[in]bpageBuffer block to write
[in]syncTrue if sync IO requested
Returns
DB_SUCCESS or error code

◆ write_complete()

void dblwr::write_complete ( buf_page_t bpage,
buf_flush_t  flush_type 
)
noexcept

Updates the double write buffer when a write request is completed.

Parameters
[in]bpageBlock that has just been writtent to disk.
[in]flush_typeFlush type that triggered the write.

Variable Documentation

◆ batch_size

ulong dblwr::batch_size {}

Maximum number of pages to write in one batch.

◆ dir

std::string dblwr::dir {"."}

Double write files location.

◆ Force_crash

Crash the server after writing this page to the data file.

◆ g_mode

ulong dblwr::g_mode {Mode::ON}

DBLWR mode.

◆ is_reduced_inited

bool dblwr::is_reduced_inited = false

true if DETECT_ONLY (aka reduced) mode is inited

◆ LEGACY_PAGE1

page_no_t dblwr::LEGACY_PAGE1
static

Legacy dblwr buffer first segment page number.

◆ LEGACY_PAGE2

page_no_t dblwr::LEGACY_PAGE2
static

Legacy dblwr buffer second segment page number.

◆ n_files

ulong dblwr::n_files {1}

Number of files to use for the double write buffer.

It must be <= than the number of buffer pool instances.

◆ n_pages

ulong dblwr::n_pages {64}

Number of pages per doublewrite thread/segment.

◆ RB_BATCH_ID_SIZE

const uint32_t dblwr::RB_BATCH_ID_SIZE = 4

◆ RB_BATCH_TYPE_SIZE

const uint32_t dblwr::RB_BATCH_TYPE_SIZE = 1

◆ RB_CHECKSUM_SIZE

const uint32_t dblwr::RB_CHECKSUM_SIZE = 4

◆ RB_DATA_LEN_SIZE

const uint32_t dblwr::RB_DATA_LEN_SIZE = 2

◆ RB_OFF_BATCH_ID

constexpr const uint32_t dblwr::RB_OFF_BATCH_ID = 0
constexpr

◆ RB_OFF_BATCH_TYPE

constexpr const uint32_t dblwr::RB_OFF_BATCH_TYPE = RB_OFF_DATA_LEN + RB_DATA_LEN_SIZE
constexpr

◆ RB_OFF_CHECKSUM

constexpr const uint32_t dblwr::RB_OFF_CHECKSUM = RB_OFF_BATCH_ID + RB_BATCH_ID_SIZE
constexpr

◆ RB_OFF_DATA_LEN

constexpr const uint32_t dblwr::RB_OFF_DATA_LEN = RB_OFF_CHECKSUM + RB_CHECKSUM_SIZE
constexpr

◆ RB_OFF_UNUSED

constexpr const uint32_t dblwr::RB_OFF_UNUSED = RB_OFF_BATCH_TYPE + RB_BATCH_TYPE_SIZE
constexpr

◆ RB_UNUSED_BYTES_SIZE

const uint32_t dblwr::RB_UNUSED_BYTES_SIZE = 9

◆ REDUCED_BATCH_PAGE_SIZE

const uint32_t dblwr::REDUCED_BATCH_PAGE_SIZE = 8192

◆ REDUCED_DATA_SIZE

constexpr const uint32_t dblwr::REDUCED_DATA_SIZE
constexpr
Initial value:
=
const uint32_t REDUCED_BATCH_PAGE_SIZE
Definition: buf0dblwr.h:230
constexpr const uint32_t REDUCED_HEADER_SIZE
Definition: buf0dblwr.h:249

◆ REDUCED_ENTRY_SIZE

constexpr const uint32_t dblwr::REDUCED_ENTRY_SIZE
constexpr
Initial value:
=
sizeof(space_id_t) + sizeof(page_no_t) + sizeof(lsn_t)
uint32_t space_id_t
Tablespace identifier.
Definition: api0api.h:50
uint32_t page_no_t
Page number.
Definition: api0api.h:48
uint64_t lsn_t
Type used for all log sequence number storage and arithmetics.
Definition: log0types.h:62

◆ REDUCED_HEADER_SIZE

constexpr const uint32_t dblwr::REDUCED_HEADER_SIZE
constexpr
Initial value:
=
+ 9
const uint32_t RB_BATCH_TYPE_SIZE
Definition: buf0dblwr.h:239
const uint32_t RB_BATCH_ID_SIZE
Definition: buf0dblwr.h:236
const uint32_t RB_DATA_LEN_SIZE
Definition: buf0dblwr.h:238
const uint32_t RB_CHECKSUM_SIZE
Definition: buf0dblwr.h:237

◆ REDUCED_MAX_ENTRIES

constexpr const uint32_t dblwr::REDUCED_MAX_ENTRIES
constexpr
Initial value:
=
constexpr const uint32_t REDUCED_DATA_SIZE
Definition: buf0dblwr.h:259
constexpr const uint32_t REDUCED_ENTRY_SIZE
Definition: buf0dblwr.h:256