#include <log_event.h>

Inheritance diagram for Log_event:

Public Types
enum	enum_skip_reason { EVENT_SKIP_NOT, EVENT_SKIP_IGNORE, EVENT_SKIP_COUNT }
typedef unsigned char	Byte
Public Member Functions
	Log_event (enum_event_cache_type cache_type_arg=EVENT_INVALID_CACHE, enum_event_logging_type logging_type_arg=EVENT_INVALID_LOGGING)
virtual void	print (FILE file, PRINT_EVENT_INFO print_event_info)=0
void	print_timestamp (IO_CACHE file, time_t ts)
void	print_header (IO_CACHE file, PRINT_EVENT_INFO print_event_info, bool is_more)
void	print_base64 (IO_CACHE file, PRINT_EVENT_INFO print_event_info, bool is_more)
bool	wrapper_my_b_safe_write (IO_CACHE file, const uchar buf, ulong data_length)
virtual Log_event_type	get_type_code ()=0
virtual bool	is_valid () const =0
void	set_artificial_event ()
void	set_relay_log_event ()
bool	is_artificial_event () const
bool	is_relay_log_event () const
bool	is_ignorable_event () const
bool	is_no_filter_event () const
bool	is_using_trans_cache () const
bool	is_using_stmt_cache () const
bool	is_using_immediate_logging () const
	Log_event (const char buf, const Format_description_log_event description_event)
void	register_temp_buf (char *buf)
void	free_temp_buf ()
virtual int	get_data_size ()
const char *	get_type_str ()
Static Public Member Functions
static Log_event *	read_log_event (IO_CACHE file, const Format_description_log_event description_event, my_bool crc_check)
static void *	operator new (size_t size)
static void	operator delete (void *ptr, size_t)
static void *	operator new (size_t, void *ptr)
static void	operator delete (void , void )
static Log_event *	read_log_event (const char buf, uint event_len, const char error, const Format_description_log_event description_event, my_bool crc_check)
static const char *	get_type_str (Log_event_type type)
Public Attributes
my_off_t	log_pos
char *	temp_buf
struct timeval	when
ulong	exec_time
ulong	data_written
uint32	server_id
uint32	unmasked_server_id
uint16	flags
ulong	slave_exec_mode
enum_event_cache_type	event_cache_type
enum_event_logging_type	event_logging_type
ha_checksum	crc
ulong	mts_group_idx
Relay_log_info *	worker
ulonglong	future_event_relay_log_pos
uint8	checksum_alg
Protected Types
enum	enum_event_cache_type { EVENT_INVALID_CACHE = 0, EVENT_STMT_CACHE, EVENT_TRANSACTIONAL_CACHE, EVENT_NO_CACHE, EVENT_CACHE_COUNT }
enum	enum_event_logging_type { EVENT_INVALID_LOGGING = 0, EVENT_NORMAL_LOGGING, EVENT_IMMEDIATE_LOGGING, EVENT_CACHE_LOGGING_COUNT }

Detailed Description

This is the abstract base class for binary log events.

Binary Format

Any Log_event saved on disk consists of the following three components.

Common-Header
Post-Header
Body

The Common-Header, documented in the table below, always has the same form and length within one version of MySQL. Each event type specifies a format and length of the Post-Header. The length of the Common-Header is the same for all events of the same type. The Body may be of different format and length even for different events of the same type. The binary formats of Post-Header and Body are documented separately in each subclass. The binary format of Common-Header is as follows.

Common-Header
Name	Format	Description
timestamp	4 byte unsigned integer	The time when the query started, in seconds since 1970.
type	1 byte enumeration	See enum Log_event_type.
server_id	4 byte unsigned integer	Server ID of the server that created the event.
total_size	4 byte unsigned integer	The total size of this event, in bytes. In other words, this is the sum of the sizes of Common-Header, Post-Header, and Body.
master_position	4 byte unsigned integer	The position of the next event in the master binary log, in bytes from the beginning of the file. In a binlog that is not a relay log, this is just the position of the next event, in bytes from the beginning of the file. In a relay log, this is the position of the next event in the master's binlog.
flags	2 byte bitfield	See Log_event::flags.

Summing up the numbers above, we see that the total size of the common header is 19 bytes.

Format of Atomic Primitives

All numbers, whether they are 16-, 24-, 32-, or 64-bit numbers, are stored in little endian, i.e., the least significant byte first, unless otherwise specified.

Some events use a special format for efficient representation of unsigned integers, called Packed Integer. A Packed Integer has the capacity of storing up to 8-byte integers, while small integers still can use 1, 3, or 4 bytes. The value of the first byte determines how to read the number, according to the following table:

Format of Packed Integer
First byte	Format
0-250	The first byte is the number (in the range 0-250), and no more bytes are used.
252	Two more bytes are used. The number is in the range 251-0xffff.
253	Three more bytes are used. The number is in the range 0xffff-0xffffff.
254	Eight more bytes are used. The number is in the range 0xffffff-0xffffffffffffffff.

Strings are stored in various formats. The format of each string is documented separately.

Member Enumeration Documentation

enum Log_event::enum_skip_reason

Enumeration of what kinds of skipping (and non-skipping) that can occur when the slave executes an event.

See also:: shall_skip; do_shall_skip

Enumerator:

EVENT_SKIP_NOT

Don't skip event.

EVENT_SKIP_IGNORE

Skip event by ignoring it.

This means that the slave skip counter will not be changed.

EVENT_SKIP_COUNT

Skip event and decrease skip counter.

Constructor & Destructor Documentation

Log_event::Log_event	(	enum_event_cache_type	cache_type_arg = `EVENT_INVALID_CACHE`,
		enum_event_logging_type	logging_type_arg = `EVENT_INVALID_LOGGING`
	)		`[inline]`

This minimal constructor is for when you are not even sure that there is a valid THD. For example in the server when we are shutting down or flushing logs after receiving a SIGHUP (then we must write a Rotate to the binlog but we have no THD, so we need this minimal constructor).

Member Function Documentation

const char * Log_event::get_type_str ( Log_event_type type ) [static]

Returns the human readable name of the given event type.

Prints a "session_var=value" string. Used by mysqlbinlog to print some SET commands just before it prints a query.

Returns:: returns the human readable name of the event's type

const char * Log_event::get_type_str ( )

Returns the human readable name of this event's type.

Log_event * Log_event::read_log_event	(	const char *	buf,
		uint	event_len,
		const char **	error,
		const Format_description_log_event *	description_event,
		my_bool	crc_check
	)		`[static]`

Binlog format tolerance is in (buf, event_len, description_event) constructors.

Member Data Documentation

ha_checksum Log_event::crc

Placeholder for event checksum while writing to binlog.

enum_event_cache_type Log_event::event_cache_type

Defines the type of the cache, if any, where the event will be stored before being flushed to disk.

enum_event_logging_type Log_event::event_logging_type

Defines when information, i.e. event or cache, will be flushed to disk.

uint16 Log_event::flags

Some 16 flags. See the definitions above for LOG_EVENT_TIME_F, LOG_EVENT_FORCED_ROTATE_F, LOG_EVENT_THREAD_SPECIFIC_F, and LOG_EVENT_SUPPRESS_USE_F for notes.

Reimplemented in Rotate_log_event, and User_var_log_event.

ulonglong Log_event::future_event_relay_log_pos

A copy of the main rli value stored into event to pass to MTS worker rli

ulong Log_event::mts_group_idx

Index in rli->gaq array to indicate a group that this event is purging. The index is set by Coordinator to a group terminator event is checked by Worker at the event execution. The indexed data represent the Worker progress status.

ulong Log_event::slave_exec_mode

A storage to cache the global system variable's value. Handling of a separate event will be governed its member.

Relay_log_info* Log_event::worker

MTS: associating the event with either an assigned Worker or Coordinator. Additionally the member serves to tag deferred (IRU) events to avoid the event regular time destruction.

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

log_event.h
log_event.cc

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes