Handle which allows to do reads / writes for the opened file. More...

#include <log0types.h>

Static Public Member Functions
static uint64_t	fsyncs_in_progress ()

static uint64_t	total_fsyncs ()

Private Member Functions
	Log_file_handle (const Log_file_handle &other)=delete

Log_file_handle &	operator= (const Log_file_handle &rhs)=delete

Private Attributes
Log_file_id	m_file_id
	Id of the redo log file (part of its file name) More...

Log_file_access_mode	m_access_mode
	Access mode allowed for this handle (if not yet closed). More...

Encryption_metadata &	m_encryption_metadata
	Encryption metadata to be used for all IO operations on this file except those related to the first LOG_FILE_HDR_SIZE bytes. More...

Log_file_type	m_file_type
	Type of redo log file. More...

bool	m_is_open
	Whether file is opened. More...

bool	m_is_modified
	Whether file has been modified using this handle since it was opened. More...

std::string	m_file_path
	File name. More...

pfs_os_file_t	m_raw_handle
	OS handle for file (if opened) More...

os_offset_t	m_block_size
	Size of single physical block (if opened) More...

os_offset_t	m_file_size
	Size of file in bytes (if opened) More...

Friends
struct	Log_file

Log_file_handle implementation
static Log_file_io_callback	s_on_before_read
	Callback called on each read operation. More...

static Log_file_io_callback	s_on_before_write
	Callback called on each write operation. More...

static bool	s_skip_fsyncs = false
	True iff all fsyncs should be no-op. More...

static std::atomic< size_t >	s_n_open {0}
	Number of all opened Log_file_handle existing currently. More...

static std::atomic< uint64_t >	s_fsyncs_in_progress {0}
	Number of fsyncs in-progress. More...

static std::atomic< uint64_t >	s_total_fsyncs {0}
	Total number of fsyncs that have been started since the server has started. More...

	Log_file_handle (Encryption_metadata &encryption_metadata)

	Log_file_handle (Log_file_handle &&other)

Log_file_handle &	operator= (Log_file_handle &&rhs)

	~Log_file_handle ()
	Closes handle if was opened (calling fsync if was modified). More...

bool	is_open () const

void	close ()
	Closes file represented by this handle (must be opened). More...

Log_file_id	file_id () const

const std::string &	file_path () const

os_offset_t	file_size () const

dberr_t	read (os_offset_t read_offset, os_offset_t read_size, byte *buf)
	Reads from the log file at the given offset (to the provided buffer). More...

dberr_t	write (os_offset_t write_offset, os_offset_t write_size, const byte *buf)
	Writes the provided buffer to the log file at the given offset. More...

void	fsync ()
	Executes fsync operation for this redo log file. More...

	Log_file_handle (const Log_files_context &files_ctx, Log_file_id id, Log_file_access_mode access_mode, Encryption_metadata &encryption_metadata, Log_file_type file_type)
	Tries to open a given redo log file with with a given access mode. More...

dberr_t	open ()
	Open the log file with the configured access mode. More...

IORequest	prepare_io_request (int req_type, os_offset_t offset, os_offset_t size, bool can_use_encryption)
	Creates and configures an io request object according to currently configured encryption metadata (m_encryption_*) and m_block_size. More...

Detailed Description

Handle which allows to do reads / writes for the opened file.

For particular kind of reads or writes (for checkpoint headers, data blocks, main file header or encryption header) there are helper functions defined outside this class. Unless you wanted to transfer the whole file as-is, you should rather use those functions for read/write operations.

Constructor & Destructor Documentation

◆ Log_file_handle() [1/4]

Log_file_handle::Log_file_handle ( Encryption_metadata & encryption_metadata )

explicit

◆ Log_file_handle() [2/4]

Log_file_handle::Log_file_handle ( Log_file_handle && other )

◆ ~Log_file_handle()

Log_file_handle::~Log_file_handle ( )

Closes handle if was opened (calling fsync if was modified).

Destructs the handle object.

◆ Log_file_handle() [3/4]

Log_file_handle::Log_file_handle	(	const Log_files_context &	files_ctx,
		Log_file_id	id,
		Log_file_access_mode	access_mode,
		Encryption_metadata &	encryption_metadata,
		Log_file_type	file_type
	)

private

Tries to open a given redo log file with with a given access mode.

If succeeded then this handle represents the opened file and allows to performs reads and/or writes (depends on the requested access mode). If encountered error during the attempt to open, error message is emitted to the error log, in which case this handle remains closed.

Parameters

[in]	files_ctx	context within which files exist
[in]	id	id of the log file
[in]	access_mode	access mode for the opened file
[in]	encryption_metadata	encryption metadata
[in]	file_type	type of redo file

◆ Log_file_handle() [4/4]

Log_file_handle::Log_file_handle ( const Log_file_handle & other )

privatedelete

Member Function Documentation

◆ close()

void Log_file_handle::close ( void )

Closes file represented by this handle (must be opened).

◆ file_id()

Log_file_id Log_file_handle::file_id ( ) const

Returns: id of the log file

◆ file_path()

const std::string & Log_file_handle::file_path ( ) const

Returns: path to the log file (including the file name)

◆ file_size()

os_offset_t Log_file_handle::file_size ( ) const

Returns: file size in bytes

◆ fsync()

void Log_file_handle::fsync ( )

Executes fsync operation for this redo log file.

◆ fsyncs_in_progress()

static uint64_t Log_file_handle::fsyncs_in_progress ( )

inlinestatic

Returns: number of fsyncs in-progress

◆ is_open()

bool Log_file_handle::is_open ( ) const

Returns: true iff file is opened (by this handle)

◆ open()

dberr_t Log_file_handle::open ( )

private

Open the log file with the configured access mode.

Returns: DB_SUCCESS or error

◆ operator=() [1/2]

Log_file_handle & Log_file_handle::operator= ( const Log_file_handle & rhs )

privatedelete

◆ operator=() [2/2]

Log_file_handle & Log_file_handle::operator= ( Log_file_handle && rhs )

◆ prepare_io_request()

IORequest Log_file_handle::prepare_io_request	(	int	req_type,
		os_offset_t	offset,
		os_offset_t	size,
		bool	can_use_encryption
	)

private

Creates and configures an io request object according to currently configured encryption metadata (m_encryption_*) and m_block_size.

Parameters

[in]	req_type	defines type of IO operation (read or write)
[in]	offset	offset in bytes from the beginning of the file
[in]	size	number of bytes to write or read
[in]	can_use_encryption	e.g. whether newly blocks should be encrypted

Returns: IORequest instance

◆ read()

dberr_t Log_file_handle::read	(	os_offset_t	read_offset,
		os_offset_t	read_size,
		byte *	buf
	)

Reads from the log file at the given offset (to the provided buffer).

Parameters

[in]	read_offset	offset in bytes from the beginning of the file
[in]	read_size	number of bytes to read
[out]	buf	allocated buffer to fill when reading

Returns: DB_SUCCESS or error

◆ total_fsyncs()

static uint64_t Log_file_handle::total_fsyncs ( )

inlinestatic

Returns: total number of fsyncs that have been started since the server has started

◆ write()

dberr_t Log_file_handle::write	(	os_offset_t	write_offset,
		os_offset_t	write_size,
		const byte *	buf
	)

Writes the provided buffer to the log file at the given offset.

Parameters

[in]	write_offset	offset in bytes from the beginning of the file
[in]	write_size	number of bytes to write
[in]	buf	buffer to write

Returns: DB_SUCCESS or error

Friends And Related Function Documentation

◆ Log_file

friend struct Log_file

friend

Member Data Documentation

◆ m_access_mode

Log_file_access_mode Log_file_handle::m_access_mode

private

Access mode allowed for this handle (if not yet closed).

◆ m_block_size

os_offset_t Log_file_handle::m_block_size

private

Size of single physical block (if opened)

◆ m_encryption_metadata

Encryption_metadata& Log_file_handle::m_encryption_metadata

private

Encryption metadata to be used for all IO operations on this file except those related to the first LOG_FILE_HDR_SIZE bytes.

Remarks: If Encryption::set_key() and Encryption::set_initial_vector() started to accept their arguments as const pointers, this could become a const pointer too). In such case, all usages of Encryption_metadata* inside redo log code, could also become changed to usages of the const pointer.

◆ m_file_id

Log_file_id Log_file_handle::m_file_id

private

Id of the redo log file (part of its file name)

◆ m_file_path

std::string Log_file_handle::m_file_path

private

File name.

◆ m_file_size

os_offset_t Log_file_handle::m_file_size

private

Size of file in bytes (if opened)

◆ m_file_type

Log_file_type Log_file_handle::m_file_type

private

Type of redo log file.

◆ m_is_modified

bool Log_file_handle::m_is_modified

private

Whether file has been modified using this handle since it was opened.

◆ m_is_open

bool Log_file_handle::m_is_open

private

Whether file is opened.

◆ m_raw_handle

pfs_os_file_t Log_file_handle::m_raw_handle

private

OS handle for file (if opened)

◆ s_fsyncs_in_progress

std::atomic< uint64_t > Log_file_handle::s_fsyncs_in_progress {0}

staticprivate

Number of fsyncs in-progress.

◆ s_n_open

std::atomic< size_t > Log_file_handle::s_n_open {0}

staticprivate

Number of all opened Log_file_handle existing currently.

◆ s_on_before_read

Log_file_io_callback Log_file_handle::s_on_before_read

static

Callback called on each read operation.

◆ s_on_before_write

Log_file_io_callback Log_file_handle::s_on_before_write

static

Callback called on each write operation.

◆ s_skip_fsyncs

bool Log_file_handle::s_skip_fsyncs = false

static

True iff all fsyncs should be no-op.

◆ s_total_fsyncs

std::atomic< uint64_t > Log_file_handle::s_total_fsyncs {0}

staticprivate

Total number of fsyncs that have been started since the server has started.

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

storage/innobase/include/log0types.h
storage/innobase/log/log0files_io.cc

Static Public Member Functions

Private Member Functions

Private Attributes

Friends

Log_file_handle implementation

Detailed Description

Constructor & Destructor Documentation

◆ Log_file_handle() [1/4]

◆ Log_file_handle() [2/4]

◆ ~Log_file_handle()

◆ Log_file_handle() [3/4]

◆ Log_file_handle() [4/4]

Member Function Documentation

◆ close()

◆ file_id()

◆ file_path()

◆ file_size()

◆ fsync()

◆ fsyncs_in_progress()

◆ is_open()

◆ open()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ prepare_io_request()

◆ read()

◆ total_fsyncs()

◆ write()

Friends And Related Function Documentation

◆ Log_file

Member Data Documentation

◆ m_access_mode

◆ m_block_size

◆ m_encryption_metadata

◆ m_file_id

◆ m_file_path

◆ m_file_size

◆ m_file_type

◆ m_is_modified

◆ m_is_open

◆ m_raw_handle

◆ s_fsyncs_in_progress

◆ s_n_open

◆ s_on_before_read

◆ s_on_before_write

◆ s_skip_fsyncs

◆ s_total_fsyncs