constants.go

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreedto in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package vmysql

const (
	// MaxPacketSize is the maximum payload length of a packet
	// the server supports.
	MaxPacketSize = (1 << 24) - 1

	// protocolVersion is the current version of the protocol.
	// Always 10.
	protocolVersion = 10
)

// Supported auth forms.
const (
	// MysqlNativePassword uses a salt and transmits a hash on the wire.
	MysqlNativePassword = "mysql_native_password"

	// MysqlClearPassword transmits the password in the clear.
	MysqlClearPassword = "mysql_clear_password"

	// MysqlDialog uses the dialog plugin on the client side.
	// It transmits data in the clear.
	MysqlDialog = "dialog"
)

// Capability flags.
// Originally found in include/mysql/mysql_com.h
const (
	// CapabilityClientLongPassword is CLIENT_LONG_PASSWORD.
	// New more secure passwords. Assumed to be set since 4.1.1.
	// We do not check this anywhere.
	CapabilityClientLongPassword = 1

	// CapabilityClientFoundRows is CLIENT_FOUND_ROWS.
	CapabilityClientFoundRows = 1 << 1

	// CapabilityClientLongFlag is CLIENT_LONG_FLAG.
	// Longer flags in Protocol::ColumnDefinition320.
	// Set it everywhere, not used, as we use Protocol::ColumnDefinition41.
	CapabilityClientLongFlag = 1 << 2

	// CapabilityClientConnectWithDB is CLIENT_CONNECT_WITH_DB.
	// One can specify db on connect.
	CapabilityClientConnectWithDB = 1 << 3

	// CLIENT_NO_SCHEMA 1 << 4
	// Do not permit database.table.column. We do permit it.

	// CLIENT_COMPRESS 1 << 5
	// We do not support compression. CPU is usually our bottleneck.

	// CLIENT_ODBC 1 << 6
	// No special behavior since 3.22.

	// CLIENT_LOCAL_FILES 1 << 7
	// Client can use LOCAL INFILE request of LOAD DATA|XML.
	// We do not set it.
	CapabilityClientLoadDataLocal = 1 << 7

	// CLIENT_IGNORE_SPACE 1 << 8
	// Parser can ignore spaces before '('.
	// We ignore this.

	// CapabilityClientProtocol41 is CLIENT_PROTOCOL_41.
	// New 4.1 protocol. Enforced everywhere.
	CapabilityClientProtocol41 = 1 << 9

	// CLIENT_INTERACTIVE 1 << 10
	// Not specified, ignored.

	// CapabilityClientSSL is CLIENT_SSL.
	// Switch to SSL after handshake.
	CapabilityClientSSL = 1 << 11

	// CLIENT_IGNORE_SIGPIPE 1 << 12
	// Do not issue SIGPIPE if network failures occur (libmysqlclient only).

	// CapabilityClientTransactions is CLIENT_TRANSACTIONS.
	// Can send status flags in EOF_Packet.
	// This flag is optional in 3.23, but always set by the server since 4.0.
	// We just do it all the time.
	CapabilityClientTransactions = 1 << 13

	// CLIENT_RESERVED 1 << 14

	// CapabilityClientSecureConnection is CLIENT_SECURE_CONNECTION.
	// New 4.1 authentication. Always set, expected, never checked.
	CapabilityClientSecureConnection = 1 << 15

	// CapabilityClientMultiStatements is CLIENT_MULTI_STATEMENTS
	// Can handle multiple statements per COM_QUERY and COM_STMT_PREPARE.
	CapabilityClientMultiStatements = 1 << 16

	// CapabilityClientMultiResults is CLIENT_MULTI_RESULTS
	// Can send multiple resultsets for COM_QUERY.
	CapabilityClientMultiResults = 1 << 17

	// CapabilityClientPluginAuth is CLIENT_PLUGIN_AUTH.
	// Client supports plugin authentication.
	CapabilityClientPluginAuth = 1 << 19

	// CapabilityClientConnAttr is CLIENT_CONNECT_ATTRS
	// Permits connection attributes in Protocol::HandshakeResponse41.
	CapabilityClientConnAttr = 1 << 20

	// CapabilityClientPluginAuthLenencClientData is CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA
	CapabilityClientPluginAuthLenencClientData = 1 << 21

	// CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS 1 << 22
	// Announces support for expired password extension.
	// Not yet supported.

	// CLIENT_SESSION_TRACK 1 << 23
	// Can set SERVER_SESSION_STATE_CHANGED in the Status Flags
	// and send session-state change data after a OK packet.
	// Not yet supported.

	// CapabilityClientDeprecateEOF is CLIENT_DEPRECATE_EOF
	// Expects an OK (instead of EOF) after the resultset rows of a Text Resultset.
	CapabilityClientDeprecateEOF = 1 << 24
)

// Packet types.
// Originally found in include/mysql/mysql_com.h
const (
	// ComQuit is COM_QUIT.
	ComQuit = 0x01

	// ComInitDB is COM_INIT_DB.
	ComInitDB = 0x02

	// ComQuery is COM_QUERY.
	ComQuery = 0x03

	// ComPing is COM_PING.
	ComPing = 0x0e

	// ComSetOption is COM_SET_OPTION
	ComSetOption = 0x1b

	// OKPacket is the header of the OK packet.
	OKPacket = 0x00

	// EOFPacket is the header of the EOF packet.
	EOFPacket = 0xfe

	// AuthSwitchRequestPacket is used to switch auth method.
	AuthSwitchRequestPacket = 0xfe

	// ErrPacket is the header of the error packet.
	ErrPacket = 0xff

	// NullValue is the encoded value of NULL.
	NullValue = 0xfb
)

// Error codes for client-side errors.
// Originally found in include/mysql/errmsg.h and
// https://dev.mysql.com/doc/refman/5.7/en/error-messages-client.html
const (
	// CRUnknownError is CR_UNKNOWN_ERROR
	CRUnknownError = 2000

	// CRServerGone is CR_SERVER_GONE_ERROR.
	// This is returned if the client tries to send a command but it fails.
	CRServerGone = 2006

	// CRServerHandshakeErr is CR_SERVER_HANDSHAKE_ERR
	CRServerHandshakeErr = 2012

	// CRServerLost is CR_SERVER_LOST.
	// Used when:
	// - the client cannot write an initial auth packet.
	// - the client cannot read an initial auth packet.
	// - the client cannot read a response from the server.
	CRServerLost = 2013

	// CRMalformedPacket is CR_MALFORMED_PACKET
	CRMalformedPacket = 2027
)

// Error codes return in SQLErrors generated by vitess. These error codes
// are in a high range to avoid conflicting with mysql error codes below.
const (
	// ERVitessMaxRowsExceeded is when a user tries to select more rows than the max rows as enforced by vitess.
	ERVitessMaxRowsExceeded = 10001
)

// Error codes for server-side errors.
// Originally found in include/mysql/mysqld_error.h and
// https://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html
// The below are in sorted order by value, grouped by vterror code they should be bucketed into.
// See above reference for more information on each code.
const (
	// unknown
	ERUnknownError = 1105

	// unavailable
	ERServerShutdown = 1053

	// permissions
	ERAccessDeniedError = 1045

	// invalid arg
	ERUnknownComError = 1047

	ERParseError = 1064
)

// Sql states for errors.
// Originally found in include/mysql/sql_state.h
const (
	// SSUnknownSqlstate is ER_SIGNAL_EXCEPTION in
	// include/mysql/sql_state.h, but:
	// const char *unknown_sqlstate= "HY000"
	// in client.c. So using that one.
	SSUnknownSQLState = "HY000"

	// SSUnknownComError is ER_UNKNOWN_COM_ERROR
	SSUnknownComError = "08S01"

	// SSHandshakeError is ER_HANDSHAKE_ERROR

	// SSServerShutdown is ER_SERVER_SHUTDOWN
	SSServerShutdown = "08S01"

	// SSAccessDeniedError is ER_ACCESS_DENIED_ERROR
	SSAccessDeniedError = "28000"
)

// Status flags. They are returned by the server in a few cases.
// Originally found in include/mysql/mysql_com.h
// See http://dev.mysql.com/doc/internals/en/status-flags.html
const (

	// ServerMoreResultsExists is SERVER_MORE_RESULTS_EXISTS
	ServerMoreResultsExists = 0x0008
)

// A few interesting character set values.
// See http://dev.mysql.com/doc/internals/en/character-set.html#packet-Protocol::CharacterSet
const (
	// CharacterSetUtf8 is for UTF8. We use this by default.
	CharacterSetUtf8 = 33

	// CharacterSetBinary is for binary. Use by integer fields for instance.
	CharacterSetBinary = 63
)

// CharacterSetMap maps the charset name (used in ConnParams) to the
// integer value.  Interesting ones have their own constant above.
var CharacterSetMap = map[string]uint8{
	"big5":     1,
	"dec8":     3,
	"cp850":    4,
	"hp8":      6,
	"koi8r":    7,
	"latin1":   8,
	"latin2":   9,
	"swe7":     10,
	"ascii":    11,
	"ujis":     12,
	"sjis":     13,
	"hebrew":   16,
	"tis620":   18,
	"euckr":    19,
	"koi8u":    22,
	"gb2312":   24,
	"greek":    25,
	"cp1250":   26,
	"gbk":      28,
	"latin5":   30,
	"armscii8": 32,
	"utf8":     CharacterSetUtf8,
	"ucs2":     35,
	"cp866":    36,
	"keybcs2":  37,
	"macce":    38,
	"macroman": 39,
	"cp852":    40,
	"latin7":   41,
	"utf8mb4":  45,
	"cp1251":   51,
	"utf16":    54,
	"utf16le":  56,
	"cp1256":   57,
	"cp1257":   59,
	"utf32":    60,
	"binary":   CharacterSetBinary,
	"geostd8":  92,
	"cp932":    95,
	"eucjpms":  97,
}

// IsNum returns true if a MySQL type is a numeric value.
// It is the same as IS_NUM defined in mysql.h.
//
// FIXME(alainjobart) This needs to use the constants in
// replication/constants.go, so we are using numerical values here.
func IsNum(typ uint8) bool {
	return ((typ <= 9 /* MYSQL_TYPE_INT24 */ && typ != 7 /* MYSQL_TYPE_TIMESTAMP */) || typ == 13 /* MYSQL_TYPE_YEAR */ || typ == 246 /* MYSQL_TYPE_NEWDECIMAL */)
}