#include <field.h>

Inheritance diagram for Field_blob:

Public Member Functions
	Field_blob (uchar ptr_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, TABLE_SHARE share, uint blob_pack_length, const CHARSET_INFO *cs)

	Field_blob (uint32 len_arg, bool is_nullable_arg, const char field_name_arg, const CHARSET_INFO cs, bool set_packlength)

	Field_blob (const Field_blob &field)
	Copy static information and reset dynamic information. More...

	Field_blob (uint32 packlength_arg)

enum_field_types	type () const override

bool	match_collation_to_optimize_range () const override

enum ha_base_keytype	key_type () const override

type_conversion_status	store (const char to, size_t length, const CHARSET_INFO charset) override

type_conversion_status	store (double nr) override
	Store double value in Field_string or Field_varstring. More...

type_conversion_status	store (longlong nr, bool unsigned_val) override

type_conversion_status	store (const Field *from)

double	val_real () const override

longlong	val_int () const override

String *	val_str (String , String ) const override

my_decimal *	val_decimal (my_decimal *) const override

int	cmp_max (const uchar , const uchar , uint max_length) const final

int	cmp (const uchar a, const uchar b) const final

int	cmp (const uchar a, uint32 a_length, const uchar b, uint32 b_length) const

int	cmp_binary (const uchar a, const uchar b, uint32 max_length=~0L) const override

int	key_cmp (const uchar , const uchar ) const override

int	key_cmp (const uchar *str, uint length) const override

uint32	key_length () const override

size_t	make_sort_key (uchar *buff, size_t length) const override
	Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More...

size_t	make_sort_key (uchar *to, size_t length, size_t trunc_pos) const final
	Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More...

uint32	pack_length () const final

uint32	pack_length_no_ptr () const
	Return the packed length without the pointer size added. More...

uint	row_pack_length () const final

uint32	max_data_length () const override
	Get the maximum size of the data in packed format. More...

size_t	get_field_buffer_size ()

void	store_length (uchar *i_ptr, uint i_packlength, uint32 i_number)

void	store_length (uint32 number)

uint32	data_length (ptrdiff_t row_offset=0) const final

uint32	get_length (ptrdiff_t row_offset=0) const

uint32	get_length (const uchar *ptr, uint packlength) const

uint32	get_length (const uchar *ptr_arg) const

const uchar *	get_blob_data () const
	Get a const pointer to the BLOB data of this field. More...

uchar *	get_blob_data (ptrdiff_t row_offset=0)
	Get a non-const pointer to the BLOB data of this field. More...

const uchar *	data_ptr () const final
	Get a const pointer to the BLOB data of this field. More...

void	set_ptr (const uchar length, const uchar data)

void	set_ptr_offset (ptrdiff_t ptr_diff, uint32 length, const uchar *data)

void	set_ptr (uint32 length, const uchar *data)

size_t	get_key_image (uchar *buff, size_t length, imagetype type) const override

void	set_key_image (const uchar *buff, size_t length) final

void	sql_type (String &str) const override

bool	copy ()

Field_blob *	clone (MEM_ROOT *mem_root) const override
	Makes a shallow copy of the Field object. More...

uchar *	pack (uchar to, const uchar from, size_t max_length) const final
	Pack the field into a format suitable for storage and transfer. More...

uchar *	pack_with_metadata_bytes (uchar to, const uchar from, uint max_length) const final
	This function does the same thing as pack(), except for the difference that max_length does not mean the number of bytes in the output, but the maximum field length from the input (which must be exactly field->max_field_length()). More...

const uchar *	unpack (uchar , const uchar from, uint param_data) final
	Unpack a blob field from row data. More...

uint	max_packed_col_length () const final
	This is a wrapper around pack_length() used by filesort() to determine how many bytes we need for packing "addon fields". More...

void	mem_free () final

bool	has_charset () const override

uint32	max_display_length () const final
	maximum possible display length for blob. More...

uint32	char_length () const override
	maximum possible character length for blob. More...

bool	copy_blob_value (MEM_ROOT *mem_root)
	This function creates a separate copy of blob value. More...

uint	is_equal (const Create_field *new_field) const override
	Whether a field being created is type-compatible with an existing one. More...

bool	is_text_key_type () const final

void	set_keep_old_value (bool old_value_flag)
	Mark that the BLOB stored in value should be copied before updating it. More...

void	keep_old_value ()
	Save the current BLOB value to avoid that it gets overwritten. More...

void	store_in_allocated_space (const char *from, uint32 length)
	Use to store the blob value into an allocated space. More...

bool	backup_blob_field ()
	Backup data stored in 'value' into the backup_value. More...

void	restore_blob_backup ()
	Restore backup value. More...

Public Member Functions inherited from Field_longstr
	Field_longstr (uchar ptr_arg, uint32 len_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, const CHARSET_INFO charset_arg)

type_conversion_status	store_decimal (const my_decimal *d) override
	Decimal representation of Field_str. More...

bool	is_updatable () const final
	Checks whether a string field is part of write_set. More...

Public Member Functions inherited from Field_str
	Field_str (uchar ptr_arg, uint32 len_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, const CHARSET_INFO charset)

Item_result	result_type () const override

Item_result	numeric_context_result_type () const final
	Returns Item_result type of a field when it appears in numeric context such as: SELECT time_column + 1; SELECT SUM(time_column); Examples: More...

uint	decimals () const override

void	make_send_field (Send_field *field) const override
	Populates a Send_field object with metadata about the column represented by this Field object. More...

uint	repertoire () const final

const CHARSET_INFO *	charset () const override

void	set_charset (const CHARSET_INFO *charset_arg)

void	set_field_length (uint32 length) final

enum Derivation	derivation () const final

void	set_derivation (enum Derivation derivation_arg) final

bool	binary () const override

bool	str_needs_quotes () const final

void	add_to_cost (CostOfItem *cost) const override
	Update '*cost' with the fact that this Field is accessed. More...

Public Member Functions inherited from Field
	Field (const Field &)=default

void	operator= (Field &)=delete

bool	has_insert_default_general_value_expression () const
	Checks if the field is marked as having a general expression to generate default values. More...

bool	has_insert_default_datetime_value_expression () const
	Checks if the field is marked as having a datetime value expression to generate default values on inserts. More...

bool	has_update_default_datetime_value_expression () const
	Checks if the field is marked as having a datetime value expression to generate default values on updates. More...

bool	has_insert_default_constant_expression () const
	Checks if the field is marked as having a constant expression to generate default values. More...

uchar *	get_null_ptr ()

bool	is_flag_set (unsigned flag) const

void	set_flag (unsigned flag)

void	clear_flag (unsigned flag)

uint32	all_flags () const

virtual bool	is_wrapper_field () const
	If true, it's a Create_field_wrapper (a sub-class of Field used during CREATE/ALTER that we mustn't cast to other sub-classes of Field that aren't on a direct path of inheritance, e.g. More...

virtual bool	is_unsigned () const
	Whether the field is signed or not. More...

bool	is_gcol () const

bool	is_virtual_gcol () const

void	set_hidden (dd::Column::enum_hidden_type hidden)
	Sets the hidden type for this field. More...

dd::Column::enum_hidden_type	hidden () const

bool	is_hidden () const

bool	is_hidden_by_system () const

bool	is_hidden_by_user () const

bool	is_field_for_functional_index () const

	Field (uchar ptr_arg, uint32 length_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg)
	This is used as a table name when the table structure is not set up. More...

virtual	~Field ()=default

void	reset_warnings ()

void	set_tmp_nullable ()
	Turn on temporary nullability for the field. More...

void	reset_tmp_nullable ()
	Turn off temporary nullability for the field. More...

void	reset_tmp_null ()
	Reset temporary NULL value for field. More...

void	set_tmp_null ()
	Set field to temporary value NULL. More...

bool	is_tmp_nullable () const

bool	is_tmp_null () const

virtual type_conversion_status	store_packed (longlong nr)
	Store a temporal value in packed longlong format into a field. More...

virtual type_conversion_status	store_time (MYSQL_TIME *ltime, uint8 dec_arg)
	Store MYSQL_TIME value with the given amount of decimal digits into a field. More...

type_conversion_status	store_time (MYSQL_TIME *ltime)
	Store MYSQL_TYPE value into a field when the number of fractional digits is not important or is not know. More...

type_conversion_status	store (const char to, size_t length, const CHARSET_INFO cs, enum_check_fields check_level)

virtual longlong	val_time_temporal () const
	Returns TIME value in packed longlong format. More...

virtual longlong	val_date_temporal () const
	Returns DATE/DATETIME value in packed longlong format. More...

virtual longlong	val_time_temporal_at_utc () const

virtual longlong	val_date_temporal_at_utc () const

longlong	val_temporal_by_field_type () const
	Returns "native" packed longlong representation of a TIME or DATE/DATETIME field depending on field type. More...

String *	val_str (String *str) const

String *	val_int_as_str (String *val_buffer, bool unsigned_flag) const
	Interpret field value as an integer but return the result as a string. More...

virtual Item_result	cmp_type () const

virtual Item_result	cast_to_int_type () const

bool	gcol_expr_is_equal (const Create_field *field) const
	Check whether generated columns' expressions are the same. More...

virtual bool	eq (const Field *field) const

virtual bool	eq_def (const Field *field) const

virtual uint32	pack_length_in_rec () const

virtual bool	compatible_field_size (uint metadata, Relay_log_info , uint16, int order) const
	Check to see if field size is compatible with destination. More...

virtual uint	pack_length_from_metadata (uint field_metadata) const

int	save_field_metadata (uchar *first_byte)

virtual type_conversion_status	reset ()

virtual bool	get_timestamp (my_timeval tm, int warnings) const
	Returns a UTC component in `struct timeval` format. More...

virtual void	store_timestamp (const my_timeval *)
	Stores a timestamp value in timeval format in a field. More...

virtual void	set_default ()

void	evaluate_insert_default_function ()
	Evaluates the `INSERT` default function and stores the result in the field. More...

void	evaluate_update_default_function ()
	Evaluates the `UPDATE` default function, if one exists, and stores the result in the record buffer. More...

virtual bool	zero_pack () const

virtual enum_field_types	real_type () const

virtual enum_field_types	binlog_type () const

int	cmp (const uchar *str) const

virtual int	cmp_offset (ptrdiff_t row_offset) const

virtual int	cmp_binary_offset (ptrdiff_t row_offset) const

bool	is_null (ptrdiff_t row_offset=0) const
	Check whether the full table's row is NULL or the Field has value NULL. More...

bool	is_real_null (ptrdiff_t row_offset=0) const
	Check whether the Field has value NULL (temporary or actual). More...

bool	is_null_in_record (const uchar *record) const
	Check if the Field has value NULL or the record specified by argument has value NULL for this Field. More...

void	set_null (ptrdiff_t row_offset=0)
	Set field to value NULL. More...

void	set_notnull (ptrdiff_t row_offset=0)
	Set field to value NOT NULL. More...

type_conversion_status	check_constraints (int mysql_errno)
	Check NOT NULL constraint on the field after temporary nullability is disabled. More...

void	set_check_for_truncated_fields (enum_check_fields check_for_truncated_fields)
	Remember the value of THD::check_for_truncated_fields to handle possible NOT-NULL constraint errors after BEFORE-trigger execution is finished. More...

bool	is_nullable () const

uint	null_offset (const uchar *record) const

uint	null_offset () const

void	set_null_ptr (uchar *p_null_ptr, uint p_null_bit)

virtual bool	optimize_range (uint idx, uint part) const
	Whether this field can be used for index range scans when in the given keypart of the given index. More...

virtual bool	can_be_compared_as_longlong () const

virtual Field *	new_field (MEM_ROOT root, TABLE new_table) const

Field *	new_field (MEM_ROOT root, TABLE new_table, uchar new_ptr, uchar new_null_ptr, uint new_null_bit) const

virtual Field *	new_key_field (MEM_ROOT root, TABLE new_table, uchar new_ptr, uchar new_null_ptr, uint new_null_bit) const

Field *	new_key_field (MEM_ROOT root, TABLE new_table, uchar *new_ptr) const

void	move_field (uchar ptr_arg, uchar null_ptr_arg, uchar null_bit_arg)

virtual void	move_field_offset (ptrdiff_t ptr_diff)

virtual void	get_image (uchar buff, size_t length, const CHARSET_INFO ) const

virtual void	set_image (const uchar buff, size_t length, const CHARSET_INFO )

longlong	val_int_offset (ptrdiff_t row_offset)

longlong	val_int (uchar *new_ptr)

String *	val_str (String str, uchar new_ptr)

virtual bool	send_to_protocol (Protocol *protocol) const
	Send the value of this field over the protocol using the correct Protocol::store*() function which matches the type of the field. More...

uchar *	pack (uchar *to) const

const uchar *	unpack (const uchar *from)

virtual bool	pack_diff (uchar **to, ulonglong value_options) const
	Write the field for the binary log in diff format. More...

uint	offset (uchar *record) const

void	copy_data (ptrdiff_t src_record_offset)

virtual bool	get_date (MYSQL_TIME *ltime, my_time_flags_t fuzzydate) const

virtual bool	get_time (MYSQL_TIME *ltime) const

const CHARSET_INFO *	charset_for_protocol () const

virtual const CHARSET_INFO *	sort_charset () const

bool	set_warning (Sql_condition::enum_severity_level level, unsigned int code, int cut_increment)
	Produce warning or note about data saved into field. More...

bool	set_warning (Sql_condition::enum_severity_level level, uint code, int cut_increment, const char view_db, const char view_name)
	Produce warning or note about data saved into field. More...

bool	warn_if_overflow (int op_result)
	Process decimal library return codes and issue warnings for overflow and truncation. More...

virtual void	init (TABLE *table_arg)

longlong	convert_decimal2longlong (const my_decimal val, bool unsigned_flag, bool has_overflow)
	Conversion from decimal to longlong. More...

virtual geometry_type	get_geometry_type () const

void	dbug_print () const

ha_storage_media	field_storage_type () const

void	set_storage_type (ha_storage_media storage_type_arg)

column_format_type	column_format () const

void	set_column_format (column_format_type column_format_arg)

virtual type_conversion_status	validate_stored_val (THD *thd)

virtual void	hash (ulong nr, ulong nr2) const

virtual ulonglong	get_max_int_value () const
	Get the upper limit of the MySQL integral and floating-point type. More...

const uchar *	field_ptr () const
	Return a const pointer to where the field is stored in the record buffer. More...

uchar *	field_ptr ()
	Return a pointer to where the field is stored in the record buffer. More...

void	set_field_ptr (uchar *ptr_arg)

bool	is_part_of_actual_key (THD thd, uint cur_index, KEY cur_index_info) const
	Check whether field is part of the index taking the index extensions flag into account. More...

Key_map	get_covering_prefix_keys () const
	Get covering prefix keys. More...

virtual bool	is_array () const
	Whether the field is a typed array. More...

virtual uint32	get_length_bytes () const
	Return number of bytes the field's length takes. More...

bool	handle_old_value () const
	Whether field's old valued have to be handled. More...

virtual void	set_field_index (uint16 field_index)
	Sets field index. More...

uint16	field_index () const
	Returns field index. More...

Protected Member Functions
void	store_ptr_and_length (const char *from, uint32 length)
	Store ptr and length. More...

Protected Member Functions inherited from Field_longstr
type_conversion_status	check_string_copy_error (const char well_formed_error_pos, const char cannot_convert_error_pos, const char from_end_pos, const char end, bool count_spaces, const CHARSET_INFO from_cs, const CHARSET_INFO to_cs)
	Report "not well formed" or "cannot convert" error after storing a character string info a field. More...

Protected Member Functions inherited from Field
uchar *	pack_int16 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int16 (uchar to, const uchar from) const

uchar *	pack_int24 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int24 (uchar to, const uchar from) const

uchar *	pack_int32 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int32 (uchar to, const uchar from) const

uchar *	pack_int64 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int64 (uchar to, const uchar from) const

Static Protected Member Functions
static uchar *	get_blob_data (const uchar *position)
	Get the BLOB data pointer stored at the specified position in the record buffer. More...

Protected Attributes
uint	packlength
	The number of bytes used to represent the length of the blob. More...

String	value
	The 'value'-object is a cache fronting the storage engine. More...

Protected Attributes inherited from Field_str
const CHARSET_INFO *	field_charset

enum Derivation	field_derivation

Protected Attributes inherited from Field
uchar *	ptr
	Holds the position to the field in record. More...

Private Member Functions
virtual type_conversion_status	store_internal (const char from, size_t length, const CHARSET_INFO cs)

type_conversion_status	store_to_mem (const char from, size_t length, const CHARSET_INFO cs, size_t max_length, Blob_mem_storage *)
	Copy value to memory storage. More...

int	do_save_field_metadata (uchar *first_byte) const override
	Save the field metadata for blob fields. More...

Private Attributes
String	old_value
	In order to support update of virtual generated columns of blob type, we need to allocate the space blob needs on server for old_row and new_row respectively. More...

bool	m_keep_old_value
	Whether we need to move the content of 'value' to 'old_value' before updating the BLOB stored in 'value'. More...

String	m_blob_backup
	Backup String for table's blob fields. More...

bool	m_uses_backup {false}
	Whether the field uses table's backup value storage. More...

Additional Inherited Members
Public Types inherited from Field
enum	enum_auto_flags { NONE = 0 , NEXT_NUMBER = 1 , DEFAULT_NOW = 2 , ON_UPDATE_NOW = 4 , GENERATED_FROM_EXPRESSION = 8 }
	Flags for Field::auto_flags / Create_field::auto_flags bitmaps. More...

enum	geometry_type { GEOM_GEOMETRY = 0 , GEOM_POINT = 1 , GEOM_LINESTRING = 2 , GEOM_POLYGON = 3 , GEOM_MULTIPOINT = 4 , GEOM_MULTILINESTRING = 5 , GEOM_MULTIPOLYGON = 6 , GEOM_GEOMETRYCOLLECTION = 7 }

enum	imagetype { itRAW , itMBR }

Static Public Member Functions inherited from Field
static bool	type_can_have_key_part (enum_field_types)
	Check whether a field type can be partially indexed by a key. More...

static enum_field_types	field_type_merge (enum_field_types, enum_field_types)
	Return type of which can carry value of both given types in UNION result. More...

static Item_result	result_merge_type (enum_field_types)
	Detect Item_result by given field type of UNION merge result. More...

Public Attributes inherited from Field_str
uint32	char_length_cache

Public Attributes inherited from Field
TABLE *	table
	Pointer to TABLE object that owns this field. More...

const char *	orig_db_name {nullptr}
	Pointer to original database name, only non-NULL for a temporary table. More...

const char *	orig_table_name {nullptr}
	Pointer to original table name, only non-NULL for a temporary table. More...

const char **	table_name

const char *	field_name

LEX_CSTRING	comment

Key_map	key_start

Key_map	part_of_key
	Keys that includes this field except of prefix keys. More...

Key_map	part_of_prefixkey
	Prefix keys. More...

Key_map	part_of_sortkey

Key_map	part_of_key_not_extended
	All keys that include this field, but not extended by the storage engine to include primary key columns. More...

uint32	field_length

uchar	null_bit

uchar	auto_flags
	Bitmap of flags indicating if field value is auto-generated by default and/or on update, and in which way. More...

bool	is_created_from_null_item
	If true, this field was created in create_tmp_field_from_item from a NULL value. More...

bool	m_indexed
	True if this field belongs to some index (unlike part_of_key, the index might have only a prefix). More...

LEX_CSTRING	m_engine_attribute = EMPTY_CSTR

LEX_CSTRING	m_secondary_engine_attribute = EMPTY_CSTR

Value_generator *	gcol_info {nullptr}

bool	stored_in_db
	Indication that the field is physically stored in tables rather than just generated on SQL queries. More...

Value_generator *	m_default_val_expr {nullptr}
	Holds the expression to be used to generate default values. More...

Static Public Attributes inherited from Field
static constexpr size_t	MAX_VARCHAR_WIDTH {65535}

static constexpr size_t	MAX_TINY_BLOB_WIDTH {255}

static constexpr size_t	MAX_SHORT_BLOB_WIDTH {65535}

static constexpr size_t	MAX_MEDIUM_BLOB_WIDTH {16777215}

static constexpr size_t	MAX_LONG_BLOB_WIDTH {4294967295}

Static Protected Attributes inherited from Field
static uchar	dummy_null_buffer = ' '

Constructor & Destructor Documentation

◆ Field_blob() [1/4]

Field_blob::Field_blob	(	uchar *	ptr_arg,
		uchar *	null_ptr_arg,
		uchar	null_bit_arg,
		uchar	auto_flags_arg,
		const char *	field_name_arg,
		TABLE_SHARE *	share,
		uint	blob_pack_length,
		const CHARSET_INFO *	cs
	)

◆ Field_blob() [2/4]

Field_blob::Field_blob	(	uint32	len_arg,
		bool	is_nullable_arg,
		const char *	field_name_arg,
		const CHARSET_INFO *	cs,
		bool	set_packlength
	)

inline

◆ Field_blob() [3/4]

Field_blob::Field_blob ( const Field_blob & field )

inline

Copy static information and reset dynamic information.

◆ Field_blob() [4/4]

Field_blob::Field_blob ( uint32 packlength_arg )

explicit

Member Function Documentation

◆ backup_blob_field()

bool Field_blob::backup_blob_field ( )

Backup data stored in 'value' into the backup_value.

See also: Field_blob::backup_value

Returns: true if backup fails false otherwise

◆ char_length()

uint32 Field_blob::char_length ( ) const

overridevirtual

maximum possible character length for blob.

This method is used in Item_field::set_field to calculate max_length for Item.

For example: CREATE TABLE t2 SELECT CONCAT(tinyblob_utf8_column) FROM t1; must create a "VARCHAR(255) CHARACTER SET utf8" column.

Returns: length

Reimplemented from Field.

Reimplemented in Field_vector, and Field_typed_array.

◆ clone()

Field_blob * Field_blob::clone ( MEM_ROOT * mem_root ) const

inlineoverridevirtual

Makes a shallow copy of the Field object.

Note: This member function must be overridden in all concrete subclasses. Several of the Field subclasses are concrete even though they are not leaf classes, so the compiler will not always catch this.

Parameters

mem_root MEM_ROOT to use for memory allocation.

Return values

NULL	If memory allocation failed.

Implements Field.

Reimplemented in Field_geom, Field_vector, Field_json, and Field_typed_array.

◆ cmp() [1/2]

int Field_blob::cmp	(	const uchar *	a,
		const uchar *	b
	)		const

inlinefinalvirtual

Implements Field.

◆ cmp() [2/2]

int Field_blob::cmp	(	const uchar *	a,
		uint32	a_length,
		const uchar *	b,
		uint32	b_length
	)		const

◆ cmp_binary()

int Field_blob::cmp_binary	(	const uchar *	a,
		const uchar *	b,
		uint32	max_length = `~0L`
	)		const

overridevirtual

Reimplemented from Field.

Reimplemented in Field_json.

◆ cmp_max()

int Field_blob::cmp_max	(	const uchar *	a_ptr,
		const uchar *	b_ptr,
		uint	max_length
	)		const

finalvirtual

Reimplemented from Field.

◆ copy()

bool Field_blob::copy ( )

◆ copy_blob_value()

bool Field_blob::copy_blob_value ( MEM_ROOT * mem_root )

This function creates a separate copy of blob value.

Parameters

[in] mem_root mem_root that is used to allocate memory for 'copy_of_value'.

Returns: - Can fail if we are out of memory.

Return values

false	Success
true	Failure

◆ data_length()

uint32 Field_blob::data_length ( ptrdiff_t row_offset = 0 ) const

inlinefinalvirtual

Reimplemented from Field.

◆ data_ptr()

const uchar * Field_blob::data_ptr ( ) const

inlinefinalvirtual

Get a const pointer to the BLOB data of this field.

Reimplemented from Field.

◆ do_save_field_metadata()

int Field_blob::do_save_field_metadata ( uchar * metadata_ptr ) const

overrideprivatevirtual

Save the field metadata for blob fields.

Saves the pack length in the first byte of the field metadata array at index of *metadata_ptr.

Parameters

metadata_ptr First byte of field metadata

Returns: number of bytes written to metadata_ptr

Reimplemented from Field.

Reimplemented in Field_typed_array.

◆ get_blob_data() [1/3]

const uchar * Field_blob::get_blob_data ( ) const

inline

Get a const pointer to the BLOB data of this field.

◆ get_blob_data() [2/3]

static uchar * Field_blob::get_blob_data ( const uchar * position )

inlinestaticprotected

Get the BLOB data pointer stored at the specified position in the record buffer.

◆ get_blob_data() [3/3]

uchar * Field_blob::get_blob_data ( ptrdiff_t row_offset = 0 )

inline

Get a non-const pointer to the BLOB data of this field.

◆ get_field_buffer_size()

size_t Field_blob::get_field_buffer_size ( )

inline

◆ get_key_image()

size_t Field_blob::get_key_image	(	uchar *	buff,
		size_t	length,
		imagetype	type
	)		const

overridevirtual

Reimplemented from Field.

Reimplemented in Field_typed_array.

◆ get_length() [1/3]

uint32 Field_blob::get_length	(	const uchar *	ptr,
		uint	packlength
	)		const

◆ get_length() [2/3]

uint32 Field_blob::get_length ( const uchar * ptr_arg ) const

◆ get_length() [3/3]

uint32 Field_blob::get_length ( ptrdiff_t row_offset = 0 ) const

◆ has_charset()

bool Field_blob::has_charset ( ) const

inlineoverridevirtual

Reimplemented from Field.

Reimplemented in Field_json.

◆ is_equal()

uint Field_blob::is_equal ( const Create_field * new_field ) const

overridevirtual

Whether a field being created is type-compatible with an existing one.

Used by the ALTER TABLE code to evaluate whether the new definition of a table is compatible with the old definition so that it can determine if data needs to be copied over (table data change). Constraints and generation clause (default value, generation expression) are not checked by this function.

Parameters

new_field new field definition from alter.

Return values

IS_EQUAL_YES	if there is no change.
IS_EQUAL_PACK_LENGTH	if the data are unchanged, but the length requirements have changed
IS_EQUAL_NO	if there is an incompatible change requiring copy.

Reimplemented from Field_str.

Reimplemented in Field_geom, Field_json, and Field_vector.

◆ is_text_key_type()

bool Field_blob::is_text_key_type ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ keep_old_value()

void Field_blob::keep_old_value ( )

inline

Save the current BLOB value to avoid that it gets overwritten.

This is used when updating virtual generated columns that are BLOBs. Some storage engines require that we have both the old and new BLOB value for virtual generated columns that are indexed in order for the storage engine to be able to maintain the index. This function will transfer the buffer storing the current BLOB value from 'value' to 'old_value'. This avoids that the current BLOB value is over-written when the new BLOB value is saved into this field.

The reason this requires special handling when updating/deleting virtual columns of BLOB type is that the BLOB value is not known to the storage engine. For stored columns, the "old" BLOB value is read by the storage engine, Field_blob is made to point to the engine's internal buffer; Field_blob's internal buffer (Field_blob::value) isn't used and remains available to store the "new" value. For virtual generated columns, the "old" value is written directly into Field_blob::value when reading the record to be updated/deleted. This is done in update_generated_read_fields(). Since, in this case, the "old" value already occupies the place to store the "new" value, we must call this function before we write the "new" value into Field_blob::value object so that the "old" value does not get over-written. The table->record[1] buffer will have a pointer that points to the memory buffer inside old_value. The storage engine will use table->record[1] to read the old value for the BLOB and use table->record[0] to read the new value.

This function must be called before we store the new BLOB value in this field object.

◆ key_cmp() [1/2]

int Field_blob::key_cmp	(	const uchar *	a,
		const uchar *	b
	)		const

overridevirtual

Reimplemented from Field.

Reimplemented in Field_typed_array.

◆ key_cmp() [2/2]

int Field_blob::key_cmp	(	const uchar *	str,
		uint	length
	)		const

overridevirtual

Reimplemented from Field.

Reimplemented in Field_typed_array.

◆ key_length()

uint32 Field_blob::key_length ( ) const

inlineoverridevirtual

Reimplemented from Field.

Reimplemented in Field_typed_array.

◆ key_type()

enum ha_base_keytype Field_blob::key_type ( ) const

inlineoverridevirtual

Reimplemented from Field.

Reimplemented in Field_geom.

◆ make_sort_key() [1/2]

size_t Field_blob::make_sort_key	(	uchar *	buff,
		size_t	length
	)		const

overridevirtual

Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.

Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer.

Parameters

buff	The buffer, assumed to be at least length bytes.
length	Number of bytes to write.

Return values

The	number of bytes actually written.

Note: This is now only used by replication; filesort makes its own sort keys based off of Items, not Fields.

Implements Field.

Reimplemented in Field_json, Field_typed_array, Field_json, Field_typed_array, and Field_typed_array.

◆ make_sort_key() [2/2]

size_t Field_blob::make_sort_key	(	uchar *	buff,
		size_t	length,
		size_t	trunc_pos
	)		const

finalvirtual

Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.

Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer. Field_string, Field_varstring and Field_blob classes are truncated after pos number of characters.

Parameters

buff	The buffer, assumed to be at least length bytes.
length	Number of bytes to write.
trunc_pos	Number of characters which should be included before truncation.

Return values

The	number of bytes actually written.

Note: This is now only used by replication; filesort makes its own sort keys based off of Items, not Fields.

Reimplemented from Field.

Reimplemented in Field_json, and Field_typed_array.

◆ match_collation_to_optimize_range()

bool Field_blob::match_collation_to_optimize_range ( ) const

inlineoverridevirtual

Reimplemented from Field.

Reimplemented in Field_geom, and Field_typed_array.

◆ max_data_length()

uint32 Field_blob::max_data_length ( ) const

inlineoverridevirtual

Get the maximum size of the data in packed format.

Returns: Maximum data length of the field when packed using the Field::pack() function.

Reimplemented from Field_longstr.

Reimplemented in Field_vector.

◆ max_display_length()

uint32 Field_blob::max_display_length ( ) const

finalvirtual

maximum possible display length for blob.

Returns: length

Reimplemented from Field_str.

◆ max_packed_col_length()

uint Field_blob::max_packed_col_length ( ) const

finalvirtual

This is a wrapper around pack_length() used by filesort() to determine how many bytes we need for packing "addon fields".

Returns: maximum size of a row when stored in the filesort buffer.

Reimplemented from Field.

◆ mem_free()

void Field_blob::mem_free ( void )

inlinefinalvirtual

Reimplemented from Field.

◆ pack()

uchar * Field_blob::pack	(	uchar *	to,
		const uchar *	from,
		size_t	max_length
	)		const

finalvirtual

Pack the field into a format suitable for storage and transfer.

To implement packing functionality, only the virtual function should be overridden. The other functions are just convenience functions and hence should not be overridden.

The actual format is opaque and will vary between types of Field (it is meant to be unpacked by unpack(), but be aware that it is used among others in the replication log, so you cannot change it without incurring a format break.

Note: The default implementation just copies the raw bytes of the record into the destination, but never more than max_length characters.

Parameters

to	Pointer to memory area where representation of field should be put.
from	Pointer to memory area where record representation of field is stored, typically field->field_ptr().
max_length	Available space in “to”, in bytes. pack() will not write more bytes than this; if the field is too short, the contents are not unpackable by unpack(). (It is nominally supposed to be a prefix of what would have been written with a full buffer, ie., the same as packing and then truncating the output, but not all Field classes follow this.)

Returns: The byte after the last byte in “to” written to. If the return value is equal to (to + max_length), it could either be that the value fit exactly, or that the buffer was too small; you cannot distinguish between the two cases based on the return value alone.

Reimplemented from Field.

◆ pack_length()

uint32 Field_blob::pack_length ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ pack_length_no_ptr()

uint32 Field_blob::pack_length_no_ptr ( ) const

inline

Return the packed length without the pointer size added.

This is used to determine the size of the actual data in the row buffer.

Returns: The length of the raw data itself without the pointer.

◆ pack_with_metadata_bytes()

uchar * Field_blob::pack_with_metadata_bytes	(	uchar *	to,
		const uchar *	from,
		uint	max_length
	)		const

finalvirtual

This function does the same thing as pack(), except for the difference that max_length does not mean the number of bytes in the output, but the maximum field length from the input (which must be exactly field->max_field_length()).

The difference is currently only relevant for Field_blob, but can be summed up as follows:

If the actual field length is longer than "max_length", by way of software bug or otherwise, the function may behave as if it were shorter, and write something that is still readable by unpack().
There is no bounds checking; the caller must verify that there is sufficient space in "to". Even in the case of truncation, "to" must be long enough to hold the untruncated field, as the return pointer would otherwise be invalid, causing undefined behavior as per the C++ standard.

Reimplemented from Field.

◆ restore_blob_backup()

void Field_blob::restore_blob_backup ( )

Restore backup value.

See also: Field_blob::backup_value

◆ row_pack_length()

uint Field_blob::row_pack_length ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ set_keep_old_value()

void Field_blob::set_keep_old_value ( bool old_value_flag )

inline

Mark that the BLOB stored in value should be copied before updating it.

When updating virtual generated columns we need to keep the old 'value' for BLOBs since this can be needed when the storage engine does the update. During read of the record the old 'value' for the BLOB is evaluated and stored in 'value'. This function is to be used to specify that we need to copy this BLOB 'value' into 'old_value' before we compute the new BLOB 'value'. For more information

See also: Field_blob::keep_old_value().

◆ set_key_image()

void Field_blob::set_key_image	(	const uchar *	buff,
		size_t	length
	)

finalvirtual

Reimplemented from Field.

◆ set_ptr() [1/2]

void Field_blob::set_ptr	(	const uchar *	length,
		const uchar *	data
	)

inline

◆ set_ptr() [2/2]

void Field_blob::set_ptr	(	uint32	length,
		const uchar *	data
	)

inline

◆ set_ptr_offset()

void Field_blob::set_ptr_offset	(	ptrdiff_t	ptr_diff,
		uint32	length,
		const uchar *	data
	)

inline

◆ sql_type()

void Field_blob::sql_type ( String & str ) const

overridevirtual

Implements Field.

Reimplemented in Field_vector, Field_geom, Field_typed_array, and Field_json.

◆ store() [1/4]

type_conversion_status Field_blob::store	(	const char *	to,
		size_t	length,
		const CHARSET_INFO *	charset
	)

overridevirtual

Implements Field_str.

Reimplemented in Field_vector, Field_geom, Field_vector, Field_geom, Field_json, and Field_typed_array.

◆ store() [2/4]

type_conversion_status Field_blob::store ( const Field * from )

◆ store() [3/4]

type_conversion_status Field_blob::store ( double nr )

overridevirtual

Store double value in Field_string or Field_varstring.

Pretty prints double number into field_length characters buffer.

Parameters

nr number

Reimplemented from Field_str.

Reimplemented in Field_vector, Field_geom, Field_vector, Field_geom, Field_json, and Field_typed_array.

◆ store() [4/4]

type_conversion_status Field_blob::store	(	longlong	nr,
		bool	unsigned_val
	)

overridevirtual

Implements Field_str.

Reimplemented in Field_vector, Field_geom, Field_vector, Field_geom, Field_json, and Field_typed_array.

◆ store_in_allocated_space()

void Field_blob::store_in_allocated_space	(	const char *	from,
		uint32	length
	)

inline

Use to store the blob value into an allocated space.

◆ store_internal()

type_conversion_status Field_blob::store_internal	(	const char *	from,
		size_t	length,
		const CHARSET_INFO *	cs
	)

privatevirtual

Reimplemented in Field_geom.

◆ store_length() [1/2]

void Field_blob::store_length	(	uchar *	i_ptr,
		uint	i_packlength,
		uint32	i_number
	)

◆ store_length() [2/2]

void Field_blob::store_length ( uint32 number )

inline

◆ store_ptr_and_length()

void Field_blob::store_ptr_and_length	(	const char *	from,
		uint32	length
	)

inlineprotected

Store ptr and length.

◆ store_to_mem()

type_conversion_status Field_blob::store_to_mem	(	const char *	from,
		size_t	length,
		const CHARSET_INFO *	cs,
		size_t	max_length,
		Blob_mem_storage *
	)

private

Copy value to memory storage.

Store a blob value to memory storage.

Parameters

from	the string value to store.
length	length of the string value.
cs	character set of the string value.
max_length	Cut at this length safely (multibyte aware).

◆ type()

enum_field_types Field_blob::type ( ) const

inlineoverridevirtual

Implements Field.

Reimplemented in Field_vector, Field_geom, Field_json, and Field_typed_array.

◆ unpack()

const uchar * Field_blob::unpack	(	uchar *	,
		const uchar *	from,
		uint	param_data
	)

finalvirtual

Unpack a blob field from row data.

This method is used to unpack a blob field from a master whose size of the field is less than that of the slave. Note: This method is included to satisfy inheritance rules, but is not needed for blob fields. It simply is used as a pass-through to the original unpack() method for blob fields.

Parameters

from	Source of the data
param_data	The "metadata", as stored in the Table_map_log_event for this field. This metadata is the number of bytes used to represent the length of the blob (1, 2, 3, or 4).

Returns: New pointer into memory based on from + length of the data

Reimplemented from Field.

◆ val_decimal()

my_decimal * Field_blob::val_decimal ( my_decimal * decimal_value ) const

overridevirtual

Implements Field.

Reimplemented in Field_json.

◆ val_int()

longlong Field_blob::val_int ( void ) const

overridevirtual

Implements Field.

Reimplemented in Field_json.

◆ val_real()

double Field_blob::val_real ( void ) const

overridevirtual

Implements Field.

Reimplemented in Field_json.

◆ val_str()

String * Field_blob::val_str	(	String *	,
		String *	val_ptr
	)		const

overridevirtual

Implements Field.

Reimplemented in Field_vector, and Field_json.

Member Data Documentation

◆ m_blob_backup

String Field_blob::m_blob_backup

private

Backup String for table's blob fields.

UPDATE of a virtual field (for index update) requires two values to be kept at the same time - 'new' and 'old' since SE (InnoDB) doesn't know the latter. In the case when there was an indexed record, it got deleted and When INSERT inserts into an index a record that coincides with a previously deleted one, InnoDB needs to recalculate value that was deleted in order to properly insert the new one. When two above overlap, a field have to keep 3 different values at the same time - 'new', 'old' and 'deleted'. This backup_value is used by

See also: my_eval_gcolumn_expr_helper() to save 'new' and provide space for 'deleted' to avoid thrashing the former. Unlike the old_value, backup_value is allocated once and reused for each new re-calculation, to avoid excessive [re-]allocations. It's freed at the end of statement. Since InnoDB consumes calculated values only after all needed table's virtual fields were calculated, we have to have such backup buffer for each field.

Also used for set operation hashing: we need to compare the new and the existing record with the same hash.

◆ m_keep_old_value

bool Field_blob::m_keep_old_value

private

Whether we need to move the content of 'value' to 'old_value' before updating the BLOB stored in 'value'.

This needs to be done for updates of BLOB columns that are virtual since the storage engine does not have its own copy of the old 'value'. This variable is set to true when we read the data into 'value'. It is reset when we move 'value' to 'old_value'. The purpose of having this is to avoid that we do the move operation from 'value' to 'old_value' more than one time per record. Currently, this variable is introduced because the following call in sql_data_change.cc: \/**

◆ m_uses_backup

bool Field_blob::m_uses_backup {false}

private

Whether the field uses table's backup value storage.

See also: TABLE::m_blob_backup. Used only for debug.

◆ old_value

String Field_blob::old_value

private

In order to support update of virtual generated columns of blob type, we need to allocate the space blob needs on server for old_row and new_row respectively.

This variable is used to record the allocated blob space for old_row.

◆ packlength

uint Field_blob::packlength

protected

The number of bytes used to represent the length of the blob.

◆ value

String Field_blob::value

protected

The 'value'-object is a cache fronting the storage engine.

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

sql/field.h
sql/field.cc

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ Field_blob() [1/4]

◆ Field_blob() [2/4]

◆ Field_blob() [3/4]

◆ Field_blob() [4/4]

Member Function Documentation

◆ backup_blob_field()

◆ char_length()

◆ clone()

◆ cmp() [1/2]

◆ cmp() [2/2]

◆ cmp_binary()

◆ cmp_max()

◆ copy()

◆ copy_blob_value()

◆ data_length()

◆ data_ptr()

◆ do_save_field_metadata()

◆ get_blob_data() [1/3]

◆ get_blob_data() [2/3]

◆ get_blob_data() [3/3]

◆ get_field_buffer_size()

◆ get_key_image()

◆ get_length() [1/3]

◆ get_length() [2/3]

◆ get_length() [3/3]

◆ has_charset()

◆ is_equal()

◆ is_text_key_type()

◆ keep_old_value()

◆ key_cmp() [1/2]

◆ key_cmp() [2/2]

◆ key_length()

◆ key_type()

◆ make_sort_key() [1/2]

◆ make_sort_key() [2/2]

◆ match_collation_to_optimize_range()

◆ max_data_length()

◆ max_display_length()

◆ max_packed_col_length()

◆ mem_free()

◆ pack()

◆ pack_length()

◆ pack_length_no_ptr()

◆ pack_with_metadata_bytes()

◆ restore_blob_backup()

◆ row_pack_length()

◆ set_keep_old_value()

◆ set_key_image()

◆ set_ptr() [1/2]

◆ set_ptr() [2/2]

◆ set_ptr_offset()

◆ sql_type()

◆ store() [1/4]

◆ store() [2/4]

◆ store() [3/4]

◆ store() [4/4]

◆ store_in_allocated_space()

◆ store_internal()

◆ store_length() [1/2]

◆ store_length() [2/2]

◆ store_ptr_and_length()

◆ store_to_mem()

◆ type()

◆ unpack()

◆ val_decimal()

◆ val_int()

◆ val_real()

◆ val_str()

Member Data Documentation

◆ m_blob_backup

◆ m_keep_old_value

◆ m_uses_backup