MySQL  8.0.16
Source Code Documentation
table_def Class Reference

A table definition from the master. More...

#include <rpl_utility.h>

Public Member Functions

 table_def ()
 No-op constructor. More...
 table_def (unsigned char *types, ulong size, uchar *field_metadata, int metadata_size, uchar *null_bitmap, uint16 flags)
 Constructor. More...
 ~table_def ()
ulong size () const
 Return the number of fields there is type data for. More...
enum_field_types binlog_type (ulong index) const
int json_column_count () const
 Return the number of JSON columns in this table. More...
enum_field_types type (ulong index) const
uint16 field_metadata (uint index) const
bool maybe_null (uint index) const
uint32 calc_field_size (uint col, uchar *master_data) const
bool compatible_with (THD *thd, Relay_log_info *rli, TABLE *table, TABLE **conv_table_var) const
 Decide if the table definition is compatible with a table. More...
TABLEcreate_conversion_table (THD *thd, Relay_log_info *rli, TABLE *target_table) const
Create a virtual in-memory temporary table structure. More...

Private Attributes

ulong m_size
unsigned char * m_type
uint m_field_metadata_size
uint16 m_flags
int m_json_column_count

Detailed Description

A table definition from the master.

The responsibilities of this class is:

  • Extract and decode table definition data from the table map event
  • Check if table definition in table map is compatible with table definition on slave
  • expose the type information so that it can be used when encoding or decoding row event data.

Constructor & Destructor Documentation

◆ table_def() [1/2]

table_def::table_def ( )

No-op constructor.

Instances of RPL_TABLE_LIST are created by first allocating memory, then placement-new-ing an RPL_TABLE_LIST object containing an uninitialized table_def object which is only conditionally initialized. See Table_map_log_event::do_apply_event().

◆ table_def() [2/2]

table_def::table_def ( unsigned char *  types,
ulong  size,
uchar field_metadata,
int  metadata_size,
uchar null_bitmap,
uint16  flags 


typesArray of types, each stored as a byte
sizeNumber of elements in array 'types'
field_metadataArray of extra information about fields
metadata_sizeSize of the field_metadata array
null_bitmapThe bitmap of fields that can be null
flagsTable flags

◆ ~table_def()

table_def::~table_def ( )

Member Function Documentation

◆ binlog_type()

enum_field_types table_def::binlog_type ( ulong  index) const

◆ calc_field_size()

uint32 table_def::calc_field_size ( uint  col,
uchar master_data 
) const

◆ compatible_with()

bool table_def::compatible_with ( THD thd,
Relay_log_info rli,
TABLE table,
TABLE **  conv_table_var 
) const

Decide if the table definition is compatible with a table.

Is the definition compatible with a table when it does not belong to the data dictionary?

Compare the definition with a table to see if it is compatible with it.

A table definition is compatible with a table if:

  • The columns types of the table definition is a (not necessarily proper) prefix of the column type of the table.
  • The other way around.
  • Each column on the master that also exists on the slave can be converted according to the current settings of SLAVE_TYPE_CONVERSIONS.
thdCurrent thread
rliPointer to relay log info
tablePointer to table to compare with.
[out]conv_table_varPointer to temporary table for holding conversion table.
Return values
1if the table definition is not compatible with table
0if the table definition is compatible with table

This function first finds out whether the table belongs to the data dictionary. When not, it will compare the master table with an existing table on the slave and see if they are compatible with respect to the current settings of SLAVE_TYPE_CONVERSIONS.

If the tables are compatible and conversions are required, tmp_table_var will be set to a virtual temporary table with field pointers for the fields that require conversions. This allow simple checking of whether a conversion are to be applied or not.

If tables are compatible, but no conversions are necessary, tmp_table_var will be set to NULL.

[in]rliRelay log info, for error reporting.
[in]tableTable to compare with
[out]conv_table_varVirtual temporary table for performing conversions, if necessary.
Return values
trueMaster table is compatible with slave table.
falseWhen the table belongs to the data dictionary or master table is not compatible with slave table.

◆ create_conversion_table()

TABLE * table_def::create_conversion_table ( THD thd,
Relay_log_info rli,
TABLE target_table 
) const

Create a virtual in-memory temporary table structure.

Create a conversion table.

The table structure has records and field array so that a row can be unpacked into the record for further processing.

In the virtual table, each field that requires conversion will have a non-NULL value, while fields that do not require conversion will have a NULL value.

Some information that is missing in the events, such as the character set for string types, are taken from the table that the field is going to be pushed into, so the target table that the data eventually need to be pushed into need to be supplied.

thdThread to allocate memory from.
rliRelay log info structure, for error reporting.
target_tableTarget table for fields.
A pointer to a temporary table with memory allocated in the thread's memroot, NULL if the table could not be created

If the function is unable to create the conversion table, an error will be printed and NULL will be returned.

Pointer to conversion table, or NULL if unable to create conversion table.

◆ field_metadata()

uint16 table_def::field_metadata ( uint  index) const

◆ json_column_count()

int table_def::json_column_count ( ) const

Return the number of JSON columns in this table.

◆ maybe_null()

bool table_def::maybe_null ( uint  index) const

◆ size()

ulong table_def::size ( ) const

Return the number of fields there is type data for.

The number of fields that there is type data for.

◆ type()

enum_field_types table_def::type ( ulong  index) const

Member Data Documentation

◆ m_field_metadata

uint16* table_def::m_field_metadata

◆ m_field_metadata_size

uint table_def::m_field_metadata_size

◆ m_flags

uint16 table_def::m_flags

◆ m_json_column_count

int table_def::m_json_column_count

◆ m_memory

uchar* table_def::m_memory

◆ m_null_bits

uchar* table_def::m_null_bits

◆ m_size

ulong table_def::m_size

◆ m_type

unsigned char* table_def::m_type

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