log_pre_8_0_30 Namespace Reference

Classes
struct	Checkpoint_header
	Meta data stored in one of two checkpoint headers. More...

Functions
os_offset_t	compute_real_offset_for_lsn (size_t n_files, os_offset_t file_size, lsn_t some_file_lsn, os_offset_t some_file_offset, lsn_t requested_lsn)
	Provides a file offset for the given lsn. More...
bool	checkpoint_header_deserialize (const byte *buf, Checkpoint_header &header)
	Deserializes the log checkpoint header stored in the given buffer. More...
std::string	file_name (Log_file_id file_id)
	Provides name of the log file with the given file id, e.g. More...
bool	files_validate_format (const Log_files_context &files_ctx, const ut::vector< Log_file_id_and_header > &files, Log_format &format)
	Validates that ib_logfile0 exists and has format older than VERSION_8_0_30. More...
static os_offset_t	compute_size_offset (os_offset_t file_size, os_offset_t real_offset)
static os_offset_t	compute_real_offset (os_offset_t file_size, os_offset_t size_offset)

Variables
constexpr const char *const	FILE_BASE_NAME = "ib_logfile"
	Prefix of log file name in the old redo format (before 8.0.30). More...
constexpr Log_file_id	FILE_MAX_ID = 99
	Maximum redo log file id in the old format (before 8.0.30). More...
constexpr os_offset_t	FIELD_CHECKPOINT_NO = 0
	Checkpoint number. More...
constexpr os_offset_t	FIELD_CHECKPOINT_LSN = 8
	Checkpoint lsn. More...
constexpr os_offset_t	FIELD_CHECKPOINT_OFFSET = 16
	Offset within the log files, which corresponds to checkpoint lsn. More...
constexpr uint32_t	FIELD_CHECKPOINT_LOG_BUF_SIZE = 24
	Size of the log buffer, when the checkpoint write was started. More...

Function Documentation

checkpoint_header_deserialize()

bool log_pre_8_0_30::checkpoint_header_deserialize	(	const byte *	buf,
		Checkpoint_header &	header
	)

Deserializes the log checkpoint header stored in the given buffer.

Parameters

[in]	buf	the buffer to deserialize
[out]	header	the deserialized header

compute_real_offset()

static os_offset_t log_pre_8_0_30::compute_real_offset ( os_offset_t  file_size, os_offset_t  size_offset  )

static

compute_real_offset_for_lsn()

os_offset_t log_pre_8_0_30::compute_real_offset_for_lsn	(	size_t	n_files,
		os_offset_t	file_size,
		lsn_t	some_file_lsn,
		os_offset_t	some_file_offset,
		lsn_t	requested_lsn
	)

Provides a file offset for the given lsn.

For this function to work, some existing file lsn and corresponding offset to that file lsn have to be provided.

Parameters

[in]	n_files	number of log files
[in]	file_size	size of each log file (in bytes)
[in]	some_file_lsn	some file_lsn for which offset is known
[in]	some_file_offset	file offset corresponding to the given some_file_lsn
[in]	requested_lsn	the given lsn for which offset is computed

Returns

file offset corresponding to the given requested_lsn

compute_size_offset()

static os_offset_t log_pre_8_0_30::compute_size_offset ( os_offset_t  file_size, os_offset_t  real_offset  )

static

file_name()

std::string log_pre_8_0_30::file_name

(

Log_file_id

file_id

)

Provides name of the log file with the given file id, e.g.

'ib_logfile0'.

Parameters

[in]

file_id

id of the log file

Returns

file name

files_validate_format()

bool log_pre_8_0_30::files_validate_format	(	const Log_files_context &	files_ctx,
		const ut::vector< Log_file_id_and_header > &	files,
		Log_format &	format
	)

Validates that ib_logfile0 exists and has format older than VERSION_8_0_30.

Parameters

[in]	files_ctx	defines context within which redo log files exist
[in]	files	non-empty list of file headers of existing log files, ordered by file_id
[out]	format	discovered redo format if true was returned

Returns

true iff ib_logfile0 exists and has format older than VERSION_8_0_30

Variable Documentation

FIELD_CHECKPOINT_LOG_BUF_SIZE

constexpr uint32_t log_pre_8_0_30::FIELD_CHECKPOINT_LOG_BUF_SIZE = 24

constexpr

Size of the log buffer, when the checkpoint write was started.

It seems it was write-only field in InnoDB. Not used by recovery.

Note

Note that when the log buffer is being resized, all the log background threads were stopped, so there was no concurrent checkpoint write (the log_checkpointer thread was stopped).

FIELD_CHECKPOINT_LSN

constexpr os_offset_t log_pre_8_0_30::FIELD_CHECKPOINT_LSN = 8

constexpr

Checkpoint lsn.

Recovery starts from this lsn and searches for the first log record group that starts since then. In InnoDB < 8.0.5, it was the exact value at which the first log record group started. Since 8.0.5, the order in flush lists became relaxed and because of that checkpoint lsn values were not precise anymore.

FIELD_CHECKPOINT_NO

constexpr os_offset_t log_pre_8_0_30::FIELD_CHECKPOINT_NO = 0

constexpr

Checkpoint number.

It was incremented by one for each next checkpoint. During recovery, all headers were scanned, and one with the maximum checkpoint number was used for the recovery (checkpoint_lsn from that header was used).

FIELD_CHECKPOINT_OFFSET

constexpr os_offset_t log_pre_8_0_30::FIELD_CHECKPOINT_OFFSET = 16

constexpr

Offset within the log files, which corresponds to checkpoint lsn.

Used for calibration of lsn and offset calculations.

FILE_BASE_NAME

constexpr const char* const log_pre_8_0_30::FILE_BASE_NAME = "ib_logfile"

constexpr

Prefix of log file name in the old redo format (before 8.0.30).

For more details

See also

Log_files_ruleset

FILE_MAX_ID

constexpr Log_file_id log_pre_8_0_30::FILE_MAX_ID = 99

constexpr

Maximum redo log file id in the old format (before 8.0.30).