To parse the frm file (continuous update) in order to resolve the Mysqlbing translation table field problem

Source: kelvin19840813 's blog http://www.cnblogs.com/kelvin19840813/

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Many people know that Mysqlbinlog explains the Binlog insert, update is in the opposite position, and the table field is @1 ... @ number, it's disgusting!!!

But did not see someone in the mysql8.0 function requirements when asked to come out, they did not propose

Only to explain the frm file, get the table field name, fields, and then corresponding to the sticker to translate the Binlog SQL statement is not a profound thing, only this diary record

0000 ~ 0001:fe 01 Identify if frm file, fixed

0002:0A is the frm_ver+3+ my_test (Create_info->varchar) of the MySQL version identification location table.cc; For 6 is the 5.0+ version of MySQL, 9 or 10 is the frm file with varchar

0003:0C innuendo enumeration values from the Handler.h file Legacy_db_type, 0 C is 12 just good is the InnoDB type, as follows:

Enum Legacy_db_type
{
Db_type_unknown=0,db_type_diab_isam=1,

..., Db_type_innodb,
......
};

0004 ~ 0005:03 00, the inverse view of the MySQL 5.0+ is always 3, if not 3, then even ...

0006 ~ 0007:00 10, looking back at the io_size:4096

0008 ~ 0009:01 00 I don't know what it is yet.

000a ~ 000d:00 40 00 00 I don't know what it is yet.

000e ~ 000f:f9 tmp_key_length; if equals 0xffff then the key length is 4 byte integer offset 0x002f

0010 ~ 0011:18 rec_length; This is a default value that stores the byte of a string

0012 ~ 0015:00 00 00 00 is the Max_Rows option for the CREATE TABLE statement

0016 ~ 0019:00 00 00 00 is the Min_rows option for the CREATE TABLE statement, in the Handler.h file

typedef struct ST_HA_CREATE_INFORMATION
{

.......

ULONGLONG Max_rows,min_rows;

...}

001a:00 no use.

001B:02 always 2, using long package fields

001c ~ 001d:a3 key_info_length- keyinfo partial byte size

001e ~ 001f:69 00 is a variable of the value of CREATE TABLE [table_option] my_base.h file ha_option_*

0020: Useless

0021:05 is the version number of the frm file

0022 ~ 0025:00 00 00 00 is the avg_row_length specified by the CREATE TABLE [Table_option]

0026:create table [Table_option] Specifies the character set encoding [DEFAULT] CHARACTER Set

0027:00 Don't know

0028:02 is the row_format of CREATE TABLE [Table_option]

Rem0types.h file

Enum Rec_format_enum {

rec_format_redundant= 0,/*!< Redundant row FORMAT */
rec_format_compact= 1,/*!< COMPACT Row FORMAT */
rec_format_compressed= 2,/*!< Compressed Row FORMAT */
rec_format_dynamic= 3/*!< DYNAMIC Row FORMAT */
};

0029:00 Raid_type MySQL 5 before the CREATE TABLE [table_option], no research on why

002a:00 raid_chunks MySQL 5 before the CREATE TABLE [table_option], no research on why

002b ~ 002e:00 xx raid_chunksize MySQL 5 before the CREATE TABLE [table_option], no research why

002f ~ 0032:f9 to index metadata KeyInfo partial byte size

0033 ~ 0036:BF C5 the MySQL version number, relates to a byte order problem, the machine is x86 so is Little-endian, the link is as follows:

Http://baike.baidu.com/link?url=Dd2Z3o5aNoUYQPG6xqIgNwr-jrNS8BTK72r42WVxr-SHhva4TnMsHrEXTcE_N4F6ZEhhe18Akg3hOBe2Eb-M9K

are unsigned int (4 bytes), Little-endian

Generate Mysql_version_major, Mysql_version_minor, Mysql_version_patch

0037 ~ 003a:33 (XX) CREATE TABLE [table_option] Extra_info information

• CONNECTION
• ENGINE
• PARTITION by
• With PARSER
• Table COMMENT

003b ~ 003c:00 xx extra_rec_buf_length

003d:00 if 0C, is the partition table, db_type_partition_db = 12 in the Handler.h file

003e ~ 003f:00 to create TABLE [table_option] of key_block_size in handler.h file of ulong Key_block_size;

Follow down to locate Forminfo_offset, which is where the table field begins.

1. Preparation of knowledge in advance, struct

Format	C	Python	Number of bytes
X	Pad byte	No value	1
C	Char	string of length 1	1
B	Signed Char	Integer	1
B	unsigned char	Integer	1
?	_bool	bool	1
H	Short	Integer	2
H	unsigned short	Integer	2
I	Int	Integer	4
I	unsigned int	Integer or Long	4
L	Long	Integer	4
L	unsigned long	Long	4
Q	Long Long	Long	8
Q	unsigned long long	Long	8
F	Float	Float	4
D	Double	Float	8
S	Char[]	String	1
P	Char[]	String	1
P	void *	Long

2. Little-endian & Big-endian's understanding, x86 is generally Little-endian

The following are fixed lengths, the problem is to find Forminfo_offset, Metadata_length and Metadata_offset:

Forminfo_offset, which is the starting position of the table field, variable

Metadata_offset = forminfo_offset + forminfo_length + screens_length

metadata_length = column_count * Bytes Arrival table 1th Field distance + Metadata_offset

Forminfo_length = 288
Header_size = 64

forminfo_names_length = File location offset:0x0004 (H), 3.23 after version 3, 2 bytes

Column_count = (Forminfo_offset + 258) (H) Total number of fields, accounting for 2 bytes
Screens_length the number of bytes reached in the FormInfo field metadata, accounting for 2 bytes
Screens_length = (Forminfo_offset + 260) (H)

This is the forminfo_offset:0x3000.

metadata_offset:0x328c

metadata_length:0x3446

Positioning the 0x3446 can know the table of the 1th field position, the 2 conversion into characters, PHP, Python has a struct's pack and unpack function, C more trouble, with 0xFF as the field name delimiter:

To be continued tomorrow. Supplemental index information and comment information ...

To parse the frm file (continuous update) in order to resolve the Mysqlbing translation table field problem