Low level functions for storing data to be send to the MySQL client. More...

#include "sql/protocol_classic.h"
#include <openssl/ssl.h>
#include <string.h>
#include <algorithm>
#include <limits>
#include "decimal.h"
#include "lex_string.h"
#include "m_ctype.h"
#include "m_string.h"
#include "my_byteorder.h"
#include "my_compiler.h"
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_loglevel.h"
#include "my_sys.h"
#include "my_time.h"
#include "mysql/com_data.h"
#include "mysql/psi/mysql_socket.h"
#include "mysqld_error.h"
#include "mysys_err.h"
#include "sql/field.h"
#include "sql/item.h"
#include "sql/item_func.h"
#include "sql/my_decimal.h"
#include "sql/mysqld.h"
#include "sql/session_tracker.h"
#include "sql/sql_class.h"
#include "sql/sql_error.h"
#include "sql/sql_lex.h"
#include "sql/sql_list.h"
#include "sql/sql_prepare.h"
#include "sql/system_variables.h"
#include "sql_string.h"
#include "template_utils.h"

Functions
static bool	net_send_error_packet (THD , uint, const char , const char *)

static bool	net_send_error_packet (NET , uint, const char , const char , bool, ulong, const CHARSET_INFO )

static bool	write_eof_packet (THD thd, NET net, uint server_status, uint statement_warn_count)
	Format EOF packet according to the current protocol and write it to the network output buffer. More...

static ulong	get_ps_param_len (enum enum_field_types type, uchar packet, ulong packet_left_len, ulong header_len, bool *err)
	Returns the length of the encoded data. More...

static bool	ensure_packet_capacity (size_t length, String *packet)
	Ensures that the packet buffer has enough capacity to hold a string of the given length. More...

static bool	net_store_data (const uchar from, size_t length, String packet)
	Store length and data in a network packet buffer. More...

static bool	net_store_zero_padded_data (const char data, size_t data_length, size_t padded_length, String packet)
	Stores a string in the network buffer. More...

bool	net_send_error (THD thd, uint sql_errno, const char err)
	Send a error string to client. More...

bool	net_send_error (NET net, uint sql_errno, const char err)
	Send a error string to client using net struct. More...

static bool	net_send_ok (THD thd, uint server_status, uint statement_warn_count, ulonglong affected_rows, ulonglong id, const char message, bool eof_identifier)
	Return OK to the client. More...

static bool	net_send_eof (THD *thd, uint server_status, uint statement_warn_count)
	Send eof (= end of result set) to the client. More...

static uchar *	net_store_length_fast (uchar *packet, size_t length)
	Faster net_store_length when we know that length is less than 65536. More...

uchar *	net_store_data (uchar to, const uchar from, size_t length)

static bool	parse_query_bind_params (THD thd, uint param_count, PS_PARAM out_parameters, unsigned char out_has_new_types, unsigned long out_parameter_count, Prepared_statement stmt_data, uchar *inout_read_pos, size_t inout_packet_left, bool receive_named_params, bool receive_parameter_set_count)

bool	store (Protocol prot, I_List< i_string > str_list)
	Send a set of strings as one long string with ',' in between. More...

static bool	store_integer (int64 value, bool unsigned_flag, uint32 zerofill, String *packet)
	Stores an integer in the protocol buffer for the text protocol. More...

static size_t	floating_point_to_text (double value, uint32 decimals, my_gcvt_arg_type gcvt_arg_type, char *buffer)
	Converts a floating-point value to text for the text protocol. More...

static bool	store_floating_point (double value, uint32 decimals, uint32 zerofill, my_gcvt_arg_type gcvt_arg_type, String *packet)
	Stores a floating-point value in the text protocol. More...

template<typename ToString >
static bool	store_temporal (ToString to_string, String *packet)
	Stores a temporal value in the protocol buffer for the text protocol. More...

static ulong	get_param_length (uchar packet, ulong packet_left_len, ulong header_len)
	Read the length of the parameter data and return it back to the caller. More...

Variables
static const unsigned int	PACKET_BUFFER_EXTRA_ALLOC = 1024

static uchar	eof_buff [1] = {(uchar)254}

Detailed Description

Low level functions for storing data to be send to the MySQL client.

The actual communication is handled by the net_xxx functions in net_serv.cc

Function Documentation

◆ ensure_packet_capacity()

static bool ensure_packet_capacity	(	size_t	length,
		String *	packet
	)

static

Ensures that the packet buffer has enough capacity to hold a string of the given length.

Parameters

	length	the length of the string
[in,out]	packet	the buffer

Returns: true if memory could not be allocated, false on success

◆ floating_point_to_text()

static size_t floating_point_to_text	(	double	value,
		uint32	decimals,
		my_gcvt_arg_type	gcvt_arg_type,
		char *	buffer
	)

static

Converts a floating-point value to text for the text protocol.

Parameters

value	the floating point value
decimals	the precision of the value
gcvt_arg_type	the type of the floating-point value
buffer	a buffer large enough to hold FLOATING_POINT_BUFFER characters plus a terminating zero character

Returns: the length of the text representation of the value

◆ get_param_length()

static ulong get_param_length	(	uchar *	packet,
		ulong	packet_left_len,
		ulong *	header_len
	)

static

Read the length of the parameter data and return it back to the caller.

Parameters

packet	a pointer to the data
packet_left_len	remaining packet length
header_len	size of the header stored at the beginning of the packet and used to specify the length of the data.

Returns: Length of data piece.

◆ get_ps_param_len()

static ulong get_ps_param_len	(	enum enum_field_types	type,
		uchar *	packet,
		ulong	packet_left_len,
		ulong *	header_len,
		bool *	err
	)

static

Returns the length of the encoded data.

Parameters

[in]	type	parameter data type
[in]	packet	network buffer
[in]	packet_left_len	number of bytes left in packet
[out]	header_len	the size of the header(bytes to be skipped)
[out]	err	boolean to store if an error occurred

◆ net_send_eof()

static bool net_send_eof	(	THD *	thd,
		uint	server_status,
		uint	statement_warn_count
	)

static

Send eof (= end of result set) to the client.

See EOF_Packet packet for the structure of the packet.

note The warning count will not be sent if 'no_flush' is set as we don't want to report the warning count until all data is sent to the client.

Parameters

thd	Thread handler
server_status	The server status
statement_warn_count	Total number of warnings

Return values

false	The message was successfully sent
true	An error occurred and the message wasn't sent properly

◆ net_send_error() [1/2]

bool net_send_error	(	NET *	net,
		uint	sql_errno,
		const char *	err
	)

Send a error string to client using net struct.

This is used initial connection handling code.

Parameters

net	Low-level net struct
sql_errno	The error code to send
err	A pointer to the error message

Return values

false	The message was sent to the client
true	An error occurred and the message wasn't sent properly

◆ net_send_error() [2/2]

bool net_send_error	(	THD *	thd,
		uint	sql_errno,
		const char *	err
	)

Send a error string to client.

Design note:

net_printf_error and net_send_error are low-level functions that shall be used only when a new connection is being established or at server startup.

For SIGNAL/RESIGNAL and GET DIAGNOSTICS functionality it's critical that every error that can be intercepted is issued in one place only, my_message_sql.

Parameters

thd	Thread handler
sql_errno	The error code to send
err	A pointer to the error message

Return values

false	The message was sent to the client
true	An error occurred and the message wasn't sent properly

◆ net_send_error_packet() [1/2]

static bool net_send_error_packet	(	NET *	net,
		uint	sql_errno,
		const char *	err,
		const char *	sqlstate,
		bool	bootstrap,
		ulong	client_capabilities,
		const CHARSET_INFO *	character_set_results
	)

static

Parameters

net	Low-level NET struct
sql_errno	The error code to send
err	A pointer to the error message
sqlstate	SQL state
bootstrap	Server is started in bootstrap mode
client_capabilities	Client capabilities flag
character_set_results	Char set info

Return values

false	The message was successfully sent
true	An error occurred and the messages wasn't sent properly

◆ net_send_error_packet() [2/2]

static bool net_send_error_packet	(	THD *	thd,
		uint	sql_errno,
		const char *	err,
		const char *	sqlstate
	)

static

Parameters

thd	Thread handler
sql_errno	The error code to send
err	A pointer to the error message
sqlstate	SQL state

Return values

false	The message was successfully sent
true	An error occurred and the messages wasn't sent properly

◆ net_send_ok()

static bool net_send_ok	(	THD *	thd,
		uint	server_status,
		uint	statement_warn_count,
		ulonglong	affected_rows,
		ulonglong	id,
		const char *	message,
		bool	eof_identifier
	)

static

Return OK to the client.

See OK_Packet for the OK packet structure.

Parameters

thd	Thread handler
server_status	The server status
statement_warn_count	Total number of warnings
affected_rows	Number of rows changed by statement
id	Auto_increment id for first row (if used)
message	Message to send to the client (Used by mysql_status)
eof_identifier	when true [FE] will be set in OK header else [00] will be used

Return values

false	The message was successfully sent
true	An error occurred and the messages wasn't sent properly

◆ net_store_data() [1/2]

static bool net_store_data	(	const uchar *	from,
		size_t	length,
		String *	packet
	)

inlinestatic

Store length and data in a network packet buffer.

Parameters

	from	the data to store
	length	the length of the data
[in,out]	packet	the buffer

Returns: true if there is not enough memory, false on success

◆ net_store_data() [2/2]

uchar * net_store_data	(	uchar *	to,
		const uchar *	from,
		size_t	length
	)

◆ net_store_length_fast()

static uchar * net_store_length_fast	(	uchar *	packet,
		size_t	length
	)

static

Faster net_store_length when we know that length is less than 65536.

We keep a separate version for that range because it's widely used in libmysql.

uint is used as argument type because of MySQL type conventions:

uint for 0..65536
ulong for 0..4294967296
ulonglong for bigger numbers.

◆ net_store_zero_padded_data()

static bool net_store_zero_padded_data	(	const char *	data,
		size_t	data_length,
		size_t	padded_length,
		String *	packet
	)

static

Stores a string in the network buffer.

The string is padded with zeros if it is shorter than the specified padded length.

Parameters

	data	the string to store
	data_length	the length of the string
	padded_length	the length of the zero-padded string
[in,out]	packet	the network buffer

◆ parse_query_bind_params()

static bool parse_query_bind_params	(	THD *	thd,
		uint	param_count,
		PS_PARAM **	out_parameters,
		unsigned char *	out_has_new_types,
		unsigned long *	out_parameter_count,
		Prepared_statement *	stmt_data,
		uchar **	inout_read_pos,
		size_t *	inout_packet_left,
		bool	receive_named_params,
		bool	receive_parameter_set_count
	)

static

◆ store()

bool store	(	Protocol *	prot,
		I_List< i_string > *	str_list
	)

Send a set of strings as one long string with ',' in between.

◆ store_floating_point()

static bool store_floating_point	(	double	value,
		uint32	decimals,
		uint32	zerofill,
		my_gcvt_arg_type	gcvt_arg_type,
		String *	packet
	)

static

Stores a floating-point value in the text protocol.

Parameters

value	the floating point value
decimals	the precision of the value
zerofill	the length up to which the value should be zero-padded, or 0 if no zero-padding should be used
gcvt_arg_type	the type of the floating-point value
packet	the destination buffer

Returns: false on success, true on error

◆ store_integer()

static bool store_integer	(	int64	value,
		bool	unsigned_flag,
		uint32	zerofill,
		String *	packet
	)

static

Stores an integer in the protocol buffer for the text protocol.

Parameters

value	the integer value to convert to a string
unsigned_flag	true if the integer is unsigned
zerofill	the length up to which the value should be zero-padded
packet	the destination buffer

Returns: false on success, true on error

◆ store_temporal()

template<typename ToString >

static bool store_temporal	(	ToString	to_string,
		String *	packet
	)

static

Stores a temporal value in the protocol buffer for the text protocol.

Parameters

to_string	the function that converts the temporal value to a string
packet	the destination buffer

Returns: false on success, true on error

◆ write_eof_packet()

static bool write_eof_packet	(	THD *	thd,
		NET *	net,
		uint	server_status,
		uint	statement_warn_count
	)

static

Format EOF packet according to the current protocol and write it to the network output buffer.

Variable Documentation

◆ eof_buff

uchar eof_buff[1] = {(uchar)254}

static

◆ PACKET_BUFFER_EXTRA_ALLOC

const unsigned int PACKET_BUFFER_EXTRA_ALLOC = 1024

static

thd	The thread handler
net	The network handler
server_status	The server status
statement_warn_count	The number of warnings

false	The message was sent successfully
true	An error occurred and the messages wasn't sent properly

Functions

Variables

Detailed Description

Function Documentation

◆ ensure_packet_capacity()

◆ floating_point_to_text()

◆ get_param_length()

◆ get_ps_param_len()

◆ net_send_eof()

◆ net_send_error() [1/2]

◆ net_send_error() [2/2]

◆ net_send_error_packet() [1/2]

◆ net_send_error_packet() [2/2]

◆ net_send_ok()

◆ net_store_data() [1/2]

◆ net_store_data() [2/2]

◆ net_store_length_fast()

◆ net_store_zero_padded_data()

◆ parse_query_bind_params()

◆ store()

◆ store_floating_point()

◆ store_integer()

◆ store_temporal()

◆ write_eof_packet()

Variable Documentation

◆ eof_buff

◆ PACKET_BUFFER_EXTRA_ALLOC