Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Connection often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Connection, and based on these observations, apply Extract Interface, too.
1 | <?php |
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9 | class Connection extends ClientConnection |
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10 | { |
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11 | |||
12 | /** |
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13 | * @var integer Sequence. Pointer of packet sequence |
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14 | */ |
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15 | public $seq = 0; |
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16 | |||
17 | /** |
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18 | * @var integer Client flags |
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19 | */ |
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20 | public $clientFlags = 239237; |
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21 | |||
22 | /** |
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23 | * @var integer |
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24 | */ |
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25 | public $threadId; |
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26 | |||
27 | /** |
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28 | * @var string |
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29 | */ |
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30 | public $scramble; |
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31 | |||
32 | /** |
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33 | * @var string |
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34 | */ |
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35 | public $serverver; |
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36 | |||
37 | /** |
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38 | * @var integer |
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39 | */ |
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40 | public $serverCaps; |
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41 | |||
42 | /** |
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43 | * @var integer |
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44 | */ |
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45 | public $serverLang; |
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46 | |||
47 | /** |
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48 | * @var integer Server flags: http://dev.mysql.com/doc/internals/en/status-flags.html |
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49 | */ |
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50 | public $serverStatus; |
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51 | |||
52 | /** |
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53 | * @var integer Number of warnings generated by the command |
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54 | */ |
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55 | public $warnCount; |
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56 | |||
57 | /** |
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58 | * @var string |
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59 | */ |
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60 | public $message; |
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61 | |||
62 | /** |
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63 | * @var integer Charset number (see MySQL charset list) |
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64 | */ |
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65 | public $charsetNumber = 0x21; |
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66 | |||
67 | /** |
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68 | * @var string User name |
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69 | */ |
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70 | protected $user = 'root'; |
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71 | |||
72 | /** |
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73 | * @var string Password |
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74 | */ |
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75 | protected $password = ''; |
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76 | |||
77 | /** |
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78 | * @var string Database name |
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79 | */ |
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80 | public $dbname = ''; |
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81 | |||
82 | /** |
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83 | * @TODO DESCR |
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84 | */ |
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85 | const STATE_STANDBY = 0; |
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86 | |||
87 | /** |
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88 | * @TODO DESCR |
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89 | */ |
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90 | const STATE_BODY = 1; |
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91 | |||
92 | /** |
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93 | * @var string Phase |
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94 | */ |
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95 | protected $phase = 0; |
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96 | |||
97 | /** |
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98 | * @TODO DESCR |
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99 | */ |
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100 | const PHASE_GOT_INIT = 1; |
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101 | |||
102 | /** |
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103 | * @TODO DESCR |
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104 | */ |
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105 | const PHASE_AUTH_SENT = 2; |
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106 | |||
107 | /** |
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108 | * @TODO DESCR |
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109 | */ |
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110 | const PHASE_AUTH_ERR = 3; |
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111 | |||
112 | /** |
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113 | * @TODO DESCR |
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114 | */ |
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115 | const PHASE_HANDSHAKED = 4; |
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116 | |||
117 | /** |
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118 | * @var integer State of pointer of incoming data. 0 - Result Set Header Packet, 1 - Field Packet, 2 - Row Packet |
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119 | */ |
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120 | protected $rsState = 0; |
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121 | |||
122 | /** |
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123 | * @TODO DESCR |
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124 | */ |
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125 | const RS_STATE_HEADER = 0; |
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126 | |||
127 | /** |
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128 | * @TODO DESCR |
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129 | */ |
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130 | const RS_STATE_FIELD = 1; |
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131 | |||
132 | /** |
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133 | * @TODO DESCR |
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134 | */ |
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135 | const RS_STATE_ROW = 2; |
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136 | |||
137 | /** |
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138 | * @var integer Packet size |
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139 | */ |
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140 | protected $pctSize = 0; |
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141 | |||
142 | /** |
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143 | * @var array Result rows |
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144 | */ |
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145 | public $resultRows = []; |
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146 | |||
147 | /** |
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148 | * @var array Result fields |
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149 | */ |
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150 | public $resultFields = []; |
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151 | |||
152 | /** |
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153 | * @var object Property holds a reference to user's object |
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154 | */ |
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155 | public $context; |
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156 | |||
157 | /** |
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158 | * @var integer INSERT_ID() |
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159 | */ |
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160 | public $insertId; |
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161 | |||
162 | /** |
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163 | * @var integer Affected rows |
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164 | */ |
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165 | public $affectedRows; |
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166 | |||
167 | /** |
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168 | * @var integer Protocol version |
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169 | */ |
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170 | public $protover = 0; |
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171 | |||
172 | /** |
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173 | * @var integer Timeout |
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174 | */ |
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175 | public $timeout = 120; |
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176 | |||
177 | /** |
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178 | * @var integer Error number |
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179 | */ |
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180 | public $errno = 0; |
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181 | |||
182 | /** |
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183 | * @var string Error message |
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184 | */ |
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185 | public $errmsg = ''; |
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186 | |||
187 | /** |
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188 | * @var integer Low mark |
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189 | */ |
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190 | protected $lowMark = 4; |
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191 | |||
192 | /** |
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193 | * Executes the given callback when/if the connection is handshaked |
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194 | * @param callable $cb Callback |
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195 | * @callback $cb ( Connection $conn, boolean $success ) |
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196 | * @return void |
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197 | */ |
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198 | View Code Duplication | public function onConnected($cb) |
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199 | { |
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200 | if ($this->phase === self::PHASE_AUTH_ERR) { |
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201 | $cb($this, false); |
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202 | } elseif ($this->phase === self::PHASE_HANDSHAKED) { |
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203 | $cb($this, true); |
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204 | } else { |
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205 | if (!$this->onConnected) { |
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206 | $this->onConnected = new StackCallbacks(); |
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207 | } |
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208 | $this->onConnected->push($cb); |
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209 | } |
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210 | } |
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211 | |||
212 | /** |
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213 | * Called when the connection is handshaked (at low-level), and peer is ready to recv. data |
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214 | * @return void |
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215 | */ |
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216 | public function onReady() |
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222 | |||
223 | /** |
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224 | * Sends a packet |
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225 | * @param string $packet Data |
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226 | * @return boolean Success |
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227 | */ |
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228 | public function sendPacket($packet) |
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233 | |||
234 | /** |
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235 | * Builds length-encoded binary string |
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236 | * @param string $s String |
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237 | * @return string Resulting binary string |
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238 | */ |
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239 | public function buildLenEncodedBinary($s) |
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261 | |||
262 | /** |
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263 | * Parses length-encoded binary integer |
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264 | * @return integer Result |
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265 | */ |
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266 | public function parseEncodedBinary() |
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286 | |||
287 | /** |
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288 | * Parse length-encoded string |
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289 | * @return integer Result |
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290 | */ |
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291 | public function parseEncodedString() |
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299 | |||
300 | /** |
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301 | * Generates auth. token |
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302 | * @param string $scramble Scramble string |
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303 | * @param string $password Password |
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304 | * @return string Result |
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305 | */ |
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306 | public function getAuthToken($scramble, $password) |
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310 | |||
311 | /** |
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312 | * Sends auth. packet |
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313 | * @return void |
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314 | */ |
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315 | public function auth() |
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316 | { |
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317 | if ($this->phase !== self::PHASE_GOT_INIT) { |
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318 | return; |
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319 | } |
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320 | $this->phase = self::PHASE_AUTH_SENT; |
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321 | View Code Duplication | $this->onResponse->push(function ($conn, $result) { |
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322 | if ($conn->onConnected) { |
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323 | $conn->connected = true; |
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324 | $conn->onConnected->executeAll($conn, $result); |
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325 | $conn->onConnected = null; |
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326 | } |
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327 | }); |
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328 | $this->clientFlags = |
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329 | Pool::CLIENT_LONG_PASSWORD | |
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330 | Pool::CLIENT_LONG_FLAG | |
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331 | Pool::CLIENT_LOCAL_FILES | |
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332 | Pool::CLIENT_PROTOCOL_41 | |
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333 | Pool::CLIENT_INTERACTIVE | |
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334 | Pool::CLIENT_TRANSACTIONS | |
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335 | Pool::CLIENT_SECURE_CONNECTION | |
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336 | Pool::CLIENT_MULTI_STATEMENTS | |
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337 | Pool::CLIENT_MULTI_RESULTS; |
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338 | |||
339 | $this->sendPacket( |
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340 | $packet = pack('VVc', $this->clientFlags, $this->pool->maxAllowedPacket, $this->charsetNumber) |
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341 | . "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" |
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342 | . $this->user . "\x00" |
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343 | . ($this->password === '' ? "\x00" : $this->buildLenEncodedBinary( |
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344 | $this->getAuthToken($this->scramble, $this->password) |
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345 | )) |
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346 | . ($this->path !== '' ? $this->path . "\x00" : '') |
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347 | ); |
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348 | } |
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349 | |||
350 | /** |
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351 | * Sends SQL-query |
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352 | * @param string $q Query |
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353 | * @param callable $cb Optional. Callback called when response received |
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354 | * @callback $cb ( Connection $conn, boolean $success ) |
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355 | * @return boolean Success |
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356 | */ |
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357 | public function query($q, $cb = null) |
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364 | |||
365 | /** |
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366 | * Begins a transaction |
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367 | * @param callable $cb Optional. Callback called when response received |
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368 | * @throws ConnectionFinished |
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369 | */ |
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370 | public function begin($cb = null) |
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375 | |||
376 | /** |
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377 | * Commit a transaction |
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378 | * @param callable $cb Optional. Callback called when response received |
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379 | * @throws ConnectionFinished |
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380 | */ |
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381 | public function commit($cb = null) |
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386 | |||
387 | /** |
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388 | * Rollback a transaction |
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389 | * @throws ConnectionFinished |
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390 | */ |
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391 | public function rollback($cb = null) |
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396 | |||
397 | /** |
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398 | * Sends echo-request |
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399 | * @param callable $cb Optional. Callback called when response received |
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400 | * @callback $cb ( Connection $conn, boolean $success ) |
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401 | * @return boolean Success |
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402 | */ |
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403 | public function ping($cb = null) |
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407 | |||
408 | /** |
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409 | * Sends arbitrary command |
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410 | * @param string $cmd Command |
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411 | * @param string $q Data |
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412 | * @param callable $cb Optional |
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413 | * @throws ConnectionFinished |
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414 | * @callback $cb ( Connection $conn, boolean $success ) |
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415 | * @return boolean Success |
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416 | */ |
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417 | View Code Duplication | public function command($cmd, $q = '', $cb = null) |
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429 | |||
430 | /** |
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431 | * Sets default database name |
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432 | * @param string $name Database name |
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433 | * @return boolean Success |
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434 | */ |
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435 | public function selectDB($name) |
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445 | |||
446 | /** |
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447 | * Called when new data received |
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448 | * @return void |
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449 | */ |
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450 | public function onRead() |
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451 | { |
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452 | packet: |
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453 | if ($this->state === self::STATE_STANDBY) { |
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454 | if ($this->bev->input->length < 4) { |
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455 | return; |
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456 | } |
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457 | $this->pctSize = Binary::bytes2int($this->read(3), true); |
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458 | $this->setWatermark($this->pctSize, $this->pctSize); |
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459 | $this->state = self::STATE_BODY; |
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460 | $this->seq = ord($this->read(1)) + 1; |
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461 | } |
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462 | /* STATE_BODY */ |
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463 | $l = $this->bev->input->length; |
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464 | if ($l < $this->pctSize) { |
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465 | return; |
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466 | } |
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467 | $this->state = self::STATE_STANDBY; |
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468 | $this->setWatermark(4); |
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469 | if ($this->phase === 0) { |
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470 | $this->phase = self::PHASE_GOT_INIT; |
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471 | $this->protover = ord($this->read(1)); |
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472 | if ($this->protover === 0xFF) { // error |
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473 | $fieldCount = $this->protover; |
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474 | $this->protover = 0; |
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475 | View Code Duplication | $this->onResponse->push(function ($conn, $result) { |
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476 | if ($conn->onConnected) { |
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477 | $conn->connected = true; |
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478 | $conn->onConnected->executeAll($conn, $result); |
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479 | $conn->onConnected = null; |
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480 | } |
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481 | }); |
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482 | goto field; |
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483 | } |
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484 | if (($p = $this->search("\x00")) === false) { |
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485 | $this->log('nul-terminator of \'serverver\' is not found'); |
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486 | $this->finish(); |
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487 | return; |
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488 | } |
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489 | $this->serverver = $this->read($p); |
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490 | $this->drain(1); // drain nul-byte |
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491 | $this->threadId = Binary::bytes2int($this->read(4), true); |
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492 | $this->scramble = $this->read(8); |
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493 | $this->drain(1); // ???? |
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494 | |||
495 | $this->serverCaps = Binary::bytes2int($this->read(2), true); |
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496 | $this->serverLang = ord($this->read(1)); |
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497 | $this->serverStatus = Binary::bytes2int($this->read(2), true); |
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498 | $this->drain(13); |
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499 | $restScramble = $this->read(12); |
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500 | $this->scramble .= $restScramble; |
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501 | $this->drain(1); |
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502 | |||
503 | $this->auth(); |
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504 | } else { |
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505 | $fieldCount = ord($this->read(1)); |
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506 | field: |
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507 | if ($fieldCount === 0xFF) { |
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508 | // Error packet |
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509 | $u = unpack('v', $this->read(2)); |
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510 | $this->errno = $u[1]; |
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511 | $state = $this->read(6); |
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512 | $this->errmsg = $this->read($this->pctSize - $l + $this->bev->input->length); |
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513 | $this->onError(); |
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514 | $this->errno = 0; |
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515 | $this->errmsg = ''; |
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516 | } elseif ($fieldCount === 0x00) { |
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517 | // OK Packet Empty |
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518 | if ($this->phase === self::PHASE_AUTH_SENT) { |
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519 | $this->phase = self::PHASE_HANDSHAKED; |
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520 | |||
521 | if ($this->dbname !== '') { |
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522 | $this->query('USE `' . $this->dbname . '`'); |
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523 | } |
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524 | } |
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525 | |||
526 | $this->affectedRows = $this->parseEncodedBinary(); |
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527 | |||
528 | $this->insertId = $this->parseEncodedBinary(); |
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529 | |||
530 | $u = unpack('v', $this->read(2)); |
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531 | $this->serverStatus = $u[1]; |
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532 | |||
533 | $u = unpack('v', $this->read(2)); |
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534 | $this->warnCount = $u[1]; |
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535 | |||
536 | $this->message = $this->read($this->pctSize - $l + $this->bev->input->length); |
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537 | $this->onResultDone(); |
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538 | } elseif ($fieldCount === 0xFE) { |
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539 | // EOF Packet |
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540 | if ($this->rsState === self::RS_STATE_ROW) { |
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541 | $this->onResultDone(); |
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542 | } else { |
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543 | ++$this->rsState; |
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544 | } |
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545 | } else { |
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546 | // Data packet |
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547 | $this->prependInput(chr($fieldCount)); |
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548 | |||
549 | if ($this->rsState === self::RS_STATE_HEADER) { |
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550 | // Result Set Header Packet |
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551 | $extra = $this->parseEncodedBinary(); |
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552 | $this->rsState = self::RS_STATE_FIELD; |
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553 | } elseif ($this->rsState === self::RS_STATE_FIELD) { |
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554 | // Field Packet |
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555 | $field = [ |
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556 | 'catalog' => $this->parseEncodedString(), |
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557 | 'db' => $this->parseEncodedString(), |
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558 | 'table' => $this->parseEncodedString(), |
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559 | 'org_table' => $this->parseEncodedString(), |
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560 | 'name' => $this->parseEncodedString(), |
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561 | 'org_name' => $this->parseEncodedString() |
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562 | ]; |
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563 | |||
564 | $this->drain(1); // filler |
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565 | |||
566 | $u = unpack('v', $this->read(2)); |
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567 | |||
568 | $field['charset'] = $u[1]; |
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569 | $u = unpack('V', $this->read(4)); |
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570 | $field['length'] = $u[1]; |
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571 | |||
572 | $field['type'] = ord($this->read(1)); |
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573 | |||
574 | $u = unpack('v', $this->read(2)); |
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575 | $field['flags'] = $u[1]; |
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576 | |||
577 | $field['decimals'] = ord($this->read(1)); |
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578 | |||
579 | $this->resultFields[] = $field; |
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580 | } elseif ($this->rsState === self::RS_STATE_ROW) { |
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581 | // Row Packet |
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582 | $row = []; |
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583 | |||
584 | for ($i = 0, $nf = sizeof($this->resultFields); $i < $nf; ++$i) { |
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585 | $row[$this->resultFields[$i]['name']] = $this->parseEncodedString(); |
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586 | } |
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587 | |||
588 | $this->resultRows[] = $row; |
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589 | } |
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590 | } |
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591 | } |
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592 | if ($this->finished) { |
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593 | return; |
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594 | } |
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595 | $this->drain($this->pctSize - $l + $this->bev->input->length); // drain the rest of packet |
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596 | goto packet; |
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597 | } |
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598 | |||
599 | /** |
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600 | * Called when connection finishes |
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601 | * @return void |
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602 | */ |
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603 | public function onFinish() |
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608 | |||
609 | /** |
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610 | * Called when the whole result received |
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611 | * @return void |
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612 | */ |
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613 | public function onResultDone() |
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621 | |||
622 | /** |
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623 | * Called when error occured |
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624 | * @return void |
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625 | */ |
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626 | public function onError() |
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642 | } |
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643 |
This check looks
TODO
comments that have been left in the code.``TODO``s show that something is left unfinished and should be attended to.