Pages recovered from the doublewrite buffer. More...

Public Types
using	Buffers = std::vector< Page , ut::allocator< Page > >

using	Page_entries = std::vector< Page_entry, ut::allocator< Page_entry > >

Public Member Functions
	Pages ()
	Default constructor. More...

	~Pages () noexcept
	Destructor. More...

void	add (page_no_t page_no, const byte *page, uint32_t n_bytes) noexcept
	Add a page frame to the doublewrite recovery buffer. More...

void	add_entry (Page_entry &pg_entry)
	Add a page entry from reduced doublewrite buffer to vector. More...

void	done_loading_prepare_for_recovery () noexcept
	Indicates that all add() calls were done, and it is time to prepare this data structure for subsequent recover() calls. More...

const byte *	find (const page_id_t &page_id) const noexcept
	Find a doublewrite copy of a page. More...

const byte *	get_first_page_content_for_recovery (space_id_t space_id, page_size_t page_size, const std::string &file_path, const byte *page_content) const
	Checks if content of the first page provided from the specified space requires recovery from the Double-write Buffer. More...

void	dblwr_recover_page (const fil_space_t &space, page_no_t page_no, byte *dblwr_page) noexcept
	Checks if Double-write recovery of the specified tablespace page is needed. More...

bool	is_actual_page_corrupted (const fil_space_t &space, const page_id_t &page_id)
	Checks if page in tablespace is corrupted or an all-zero page. More...

std::optional< lsn_t >	get_max_lsn_of_reduced_page_entries (const page_id_t &page_id) const noexcept
	Check if page was logged in reduced doublewrite buffer mode, and if so also return the maximum page LSN mentioned for all entries for this page ID. More...

void	recover (fil_space_t &space) noexcept
	Restore corrupted pages of the tablespace from the double write buffer. More...

void	check_missing_tablespaces () const noexcept
	Check if some pages could be restored because of missing tablespace IDs. More...

Buffers &	get_pages () noexcept
	Object the vector of pages. More...

Private Member Functions
void	detect_corruption_from_reduced_entries (const fil_space_t &space) noexcept
	Checks if there are any corrupted pages in the tablespace that can be found in the reduced double write buffer. More...

	Pages (const Pages &)=delete

	Pages (Pages &&)=delete

Pages &	operator= (Pages &&)=delete

Pages &	operator= (const Pages &)=delete

Private Attributes
Buffers	m_pages
	Recovered doublewrite buffer page frames. More...

Page_entries	m_page_entries
	Page entries from reduced doublewrite buffer. More...

std::unordered_set< space_id_t >	m_recovered_spaces

bool	m_is_sorted {true}
	Initially true. More...

Detailed Description

Pages recovered from the doublewrite buffer.

Member Typedef Documentation

◆ Buffers

using dblwr::recv::Pages::Buffers = std::vector<Page *, ut::allocator<Page *> >

◆ Page_entries

using dblwr::recv::Pages::Page_entries = std::vector<Page_entry, ut::allocator<Page_entry> >

Constructor & Destructor Documentation

◆ Pages() [1/3]

dblwr::recv::Pages::Pages ( )

inline

Default constructor.

◆ ~Pages()

dblwr::recv::Pages::~Pages ( )

inlinenoexcept

Destructor.

◆ Pages() [2/3]

dblwr::recv::Pages::Pages ( const Pages & )

privatedelete

◆ Pages() [3/3]

dblwr::recv::Pages::Pages ( Pages && )

privatedelete

Member Function Documentation

◆ add()

void recv::Pages::add	(	page_no_t	page_no,
		const byte *	page,
		uint32_t	n_bytes
	)

noexcept

Add a page frame to the doublewrite recovery buffer.

Parameters

[in]	page_no	Page number in the doublewrite buffer
[in]	page	Page contents
[in]	n_bytes	Size in bytes

◆ add_entry()

void dblwr::recv::Pages::add_entry ( Page_entry & pg_entry )

inline

Add a page entry from reduced doublewrite buffer to vector.

Parameters

[in] pg_entry Reduced doublewrite buffer entry

◆ check_missing_tablespaces()

void recv::Pages::check_missing_tablespaces ( ) const

noexcept

Check if some pages could be restored because of missing tablespace IDs.

◆ dblwr_recover_page()

void recv::Pages::dblwr_recover_page	(	const fil_space_t &	space,
		page_no_t	page_no,
		byte *	dblwr_page
	)

noexcept

Checks if Double-write recovery of the specified tablespace page is needed.

Checks if the provided image of the dblwr_page from the Double-write buffer is usable (non-zero and not corrupted) and if so, checks if the space 's page page_no is corrupted, in which case it uses the provided dblwr_page image to restore it. In case of any errors (IO errors, out of bounds space access) we crash the server as it means the tablespace is corrupted beyond our ability to recover and we should not attempt any more actions.

Parameters

[in]	space	Tablespace the page belongs to
[in]	page_no	Page number in the tablespace
[in]	dblwr_page	Data loaded from Double-write buffer to write to <space, page_no>

◆ detect_corruption_from_reduced_entries()

void recv::Pages::detect_corruption_from_reduced_entries ( const fil_space_t & space )

privatenoexcept

Checks if there are any corrupted pages in the tablespace that can be found in the reduced double write buffer.

Scans the stored double write buffer reduced entries for mentions of pages from the specified space, and for each such page checks if tablespace file contains a corrupted version of it and if so, we abort the Server. We cannot recover page because the entire page is not logged only an entry of space_id, page_id, LSN is logged. It is expected that the user restores from backup.

Parameters

[in] space Tablespace to check in reduced pages.

◆ done_loading_prepare_for_recovery()

void recv::Pages::done_loading_prepare_for_recovery ( )

noexcept

Indicates that all add() calls were done, and it is time to prepare this data structure for subsequent recover() calls.

◆ find()

const byte * recv::Pages::find ( const page_id_t & page_id ) const

noexcept

Find a doublewrite copy of a page.

Parameters

[in] page_id Page number to lookup

Returns: page frame

Return values

nullptr if no page was found

◆ get_first_page_content_for_recovery()

const byte * recv::Pages::get_first_page_content_for_recovery	(	space_id_t	space_id,
		page_size_t	page_size,
		const std::string &	file_path,
		const byte *	page_content
	)		const

Checks if content of the first page provided from the specified space requires recovery from the Double-write Buffer.

If the supplied page_content has a valid not corrupted page, no action is taken. If it is not, then we try to get a non-corrupted copy from the Double-write Buffer. If there are any entries in the Reduced Double-write pages list, we may crash.

Parameters

[in]	space_id	ID of the space to be checked.
[in]	page_size	Page size structure to use for the tablespace page manipulation.
[in]	file_path	Path of a file to be used for error reporting.
[in]	page_content	Content of the first page of the specified tablespace read from the disk. The buffer must hold at least `page_size.physical()` bytes.

Returns: pointer to page_content if the page does not require recovery, a pointer to page contents from the Double-write Buffer or nullptr if page_content is corrupted, but there's no valid image of it in the Double-write Buffer to restore it from.

◆ get_max_lsn_of_reduced_page_entries()

std::optional< lsn_t > dblwr::recv::Pages::get_max_lsn_of_reduced_page_entries ( const page_id_t & page_id ) const

inlinenoexcept

Check if page was logged in reduced doublewrite buffer mode, and if so also return the maximum page LSN mentioned for all entries for this page ID.

Parameters

[in] page_id Page number to lookup

Return values

Maximum LSN of the reduced entries for the specified page ID, if any is found.

◆ get_pages()

Buffers & dblwr::recv::Pages::get_pages ( )

inlinenoexcept

Object the vector of pages.

Returns: the vector of pages.

◆ is_actual_page_corrupted()

bool dblwr::recv::Pages::is_actual_page_corrupted	(	const fil_space_t &	space,
		const page_id_t &	page_id
	)

Checks if page in tablespace is corrupted or an all-zero page.

Parameters

[in]	space	Tablespace object
[in]	page_id	Page number to check for corruption

Returns: true if corrupted or page is all zero bytes.

◆ operator=() [1/2]

Pages & dblwr::recv::Pages::operator= ( const Pages & )

privatedelete

◆ operator=() [2/2]

Pages & dblwr::recv::Pages::operator= ( Pages && )

privatedelete

◆ recover()

void recv::Pages::recover ( fil_space_t & space )

noexcept

Restore corrupted pages of the tablespace from the double write buffer.

Iterates over the previously loaded double write buffer pages, but only ones that are not corrupted, searching for mentions of pages from the specified space, and for each such page checks if tablespace file contains a corrupted version of it and if so, restores it from the backup in image found in double write buffer page, unless this is impossible because the double write buffer page does not contain the body (in reduced, detect-only mode). In case of any errors (IO errors, out of bounds space access) we crash the server.

Parameters

[in] space Tablespace to restore pages in.

Member Data Documentation

◆ m_is_sorted

bool dblwr::recv::Pages::m_is_sorted {true}

private

Initially true.

Transitions to false whenever add() or add_entry() is called, and to true in done_loading_prepare_for_recovery(). Calling find(), get_max_lsn_of_reduced_page_entries(), get_first_page_content_for_recovery(), and recover() is only allowed when true.

◆ m_page_entries

Page_entries dblwr::recv::Pages::m_page_entries

private

Page entries from reduced doublewrite buffer.

◆ m_pages

Buffers dblwr::recv::Pages::m_pages

private

Recovered doublewrite buffer page frames.

◆ m_recovered_spaces

std::unordered_set<space_id_t> dblwr::recv::Pages::m_recovered_spaces

private

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

storage/innobase/buf/buf0dblwr.cc

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ Buffers

◆ Page_entries

Constructor & Destructor Documentation

◆ Pages() [1/3]

◆ ~Pages()

◆ Pages() [2/3]

◆ Pages() [3/3]

Member Function Documentation

◆ add()

◆ add_entry()

◆ check_missing_tablespaces()

◆ dblwr_recover_page()

◆ detect_corruption_from_reduced_entries()

◆ done_loading_prepare_for_recovery()

◆ find()

◆ get_first_page_content_for_recovery()

◆ get_max_lsn_of_reduced_page_entries()

◆ get_pages()

◆ is_actual_page_corrupted()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ recover()

Member Data Documentation

◆ m_is_sorted

◆ m_page_entries

◆ m_pages

◆ m_recovered_spaces