github.com/cellofellow/gopkg@v0.0.0-20140722061823-eec0544a62ad/database/mysql/driver.go (about) 1 // Copyright 2012 The Go-MySQL-Driver Authors. All rights reserved. 2 // 3 // This Source Code Form is subject to the terms of the Mozilla Public 4 // License, v. 2.0. If a copy of the MPL was not distributed with this file, 5 // You can obtain one at http://mozilla.org/MPL/2.0/. 6 7 // Go MySQL Driver - A MySQL-Driver for Go's database/sql package 8 // 9 // The driver should be used via the database/sql package: 10 // 11 // import "database/sql" 12 // import _ "github.com/chai2010/gopkg/database/mysql" 13 // 14 // db, err := sql.Open("mysql", "user:password@/dbname") 15 // 16 // See https://github.com/chai2010/gopkg/tree/master/database/mysql#usage for details 17 package mysql 18 19 import ( 20 "database/sql" 21 "database/sql/driver" 22 "net" 23 ) 24 25 // This struct is exported to make the driver directly accessible. 26 // In general the driver is used via the database/sql package. 27 type MySQLDriver struct{} 28 29 // DialFunc is a function which can be used to establish the network connection. 30 // Custom dial functions must be registered with RegisterDial 31 type DialFunc func(addr string) (net.Conn, error) 32 33 var dials map[string]DialFunc 34 35 // RegisterDial registers a custom dial function. It can then be used by the 36 // network address mynet(addr), where mynet is the registered new network. 37 // addr is passed as a parameter to the dial function. 38 func RegisterDial(net string, dial DialFunc) { 39 if dials == nil { 40 dials = make(map[string]DialFunc) 41 } 42 dials[net] = dial 43 } 44 45 // Open new Connection. 46 // See https://github.com/go-sql-driver/mysql#dsn-data-source-name for how 47 // the DSN string is formated 48 func (d MySQLDriver) Open(dsn string) (driver.Conn, error) { 49 var err error 50 51 // New mysqlConn 52 mc := &mysqlConn{ 53 maxPacketAllowed: maxPacketSize, 54 maxWriteSize: maxPacketSize - 1, 55 } 56 mc.cfg, err = parseDSN(dsn) 57 if err != nil { 58 return nil, err 59 } 60 61 // Connect to Server 62 if dial, ok := dials[mc.cfg.net]; ok { 63 mc.netConn, err = dial(mc.cfg.addr) 64 } else { 65 nd := net.Dialer{Timeout: mc.cfg.timeout} 66 mc.netConn, err = nd.Dial(mc.cfg.net, mc.cfg.addr) 67 } 68 if err != nil { 69 return nil, err 70 } 71 72 // Enable TCP Keepalives on TCP connections 73 if tc, ok := mc.netConn.(*net.TCPConn); ok { 74 if err := tc.SetKeepAlive(true); err != nil { 75 mc.Close() 76 return nil, err 77 } 78 } 79 80 mc.buf = newBuffer(mc.netConn) 81 82 // Reading Handshake Initialization Packet 83 cipher, err := mc.readInitPacket() 84 if err != nil { 85 mc.Close() 86 return nil, err 87 } 88 89 // Send Client Authentication Packet 90 if err = mc.writeAuthPacket(cipher); err != nil { 91 mc.Close() 92 return nil, err 93 } 94 95 // Read Result Packet 96 err = mc.readResultOK() 97 if err != nil { 98 // Retry with old authentication method, if allowed 99 if mc.cfg != nil && mc.cfg.allowOldPasswords && err == ErrOldPassword { 100 if err = mc.writeOldAuthPacket(cipher); err != nil { 101 mc.Close() 102 return nil, err 103 } 104 if err = mc.readResultOK(); err != nil { 105 mc.Close() 106 return nil, err 107 } 108 } else { 109 mc.Close() 110 return nil, err 111 } 112 113 } 114 115 // Get max allowed packet size 116 maxap, err := mc.getSystemVar("max_allowed_packet") 117 if err != nil { 118 mc.Close() 119 return nil, err 120 } 121 mc.maxPacketAllowed = stringToInt(maxap) - 1 122 if mc.maxPacketAllowed < maxPacketSize { 123 mc.maxWriteSize = mc.maxPacketAllowed 124 } 125 126 // Handle DSN Params 127 err = mc.handleParams() 128 if err != nil { 129 mc.Close() 130 return nil, err 131 } 132 133 return mc, nil 134 } 135 136 func init() { 137 sql.Register("mysql", &MySQLDriver{}) 138 }