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:
| 1 | <?php  | 
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| 27 | class ConnectionConfigurator  | 
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| 28 | { | 
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| 29 | protected $configuration;  | 
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| 30 | |||
| 31 | /**  | 
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| 32 | * __construct  | 
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| 33 | *  | 
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| 34 | * Initialize configuration.  | 
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| 35 | *  | 
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| 36 | * @access public  | 
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| 37 | * @param array $dsn  | 
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| 38 | */  | 
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| 39 | public function __construct($dsn)  | 
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| 40 |     { | 
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| 41 | $this->configuration = new ParameterHolder(  | 
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| 42 | [  | 
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| 43 | 'dsn' => $dsn,  | 
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| 44 | 'configuration' => $this->getDefaultConfiguration(),  | 
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| 45 | ]  | 
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| 46 | );  | 
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| 47 | $this->parseDsn();  | 
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| 48 | }  | 
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| 49 | |||
| 50 | /**  | 
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| 51 | * addConfiguration  | 
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| 52 | *  | 
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| 53 | * Add configuration settings. If settings exist, they are overridden.  | 
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| 54 | *  | 
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| 55 | * @access public  | 
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| 56 | * @param array $configuration  | 
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| 57 | * @return Connection $this  | 
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| 58 | */  | 
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| 59 | public function addConfiguration(array $configuration)  | 
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| 60 |     { | 
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| 61 | $this ->configuration->setParameter(  | 
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| 62 | 'configuration',  | 
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| 63 | array_merge(  | 
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| 64 |                 $this->configuration->getParameter('configuration'), | 
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| 65 | $configuration  | 
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| 66 | )  | 
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| 67 | );  | 
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| 68 | |||
| 69 | return $this;  | 
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| 70 | }  | 
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| 71 | |||
| 72 | /**  | 
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| 73 | * set  | 
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| 74 | *  | 
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| 75 | * Set a new configuration setting.  | 
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| 76 | *  | 
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| 77 | * @access public  | 
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| 78 | * @param string $name  | 
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| 79 | * @param mixed $value  | 
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| 80 | * @return ConnectionConfigurator $this  | 
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| 81 | */  | 
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| 82 | public function set($name, $value)  | 
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| 83 |     { | 
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| 84 |         $configuration = $this->configuration->getParameter('configuration'); | 
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| 85 | $configuration[$name] = $value;  | 
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| 86 | $this  | 
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| 87 | ->configuration  | 
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| 88 | ->setParameter(  | 
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| 89 | 'configuration',  | 
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| 90 | $configuration  | 
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| 91 | );  | 
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| 92 | |||
| 93 | return $this;  | 
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| 94 | }  | 
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| 95 | |||
| 96 | |||
| 97 | /**  | 
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| 98 | * parseDsn()  | 
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| 99 | *  | 
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| 100 | * Sets the different parameters from the DSN.  | 
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| 101 | *  | 
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| 102 | * @access private  | 
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| 103 | * @return Connection $this  | 
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| 104 | * @throws ConnectionException  | 
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| 105 | */  | 
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| 106 | private function parseDsn()  | 
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| 172 | |||
| 173 | /**  | 
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| 174 | * getConnectionString  | 
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| 175 | *  | 
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| 176 | * Return the connection string.  | 
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| 177 | *  | 
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| 178 | * @access public  | 
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| 179 | * @return string  | 
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| 180 | */  | 
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| 181 | public function getConnectionString()  | 
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| 206 | |||
| 207 | /**  | 
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| 208 | * getDefaultConfiguration  | 
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| 209 | *  | 
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| 210 | * Standalone, default configuration.  | 
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| 211 | *  | 
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| 212 | * @access protected  | 
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| 213 | * @return array  | 
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| 214 | */  | 
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| 215 | protected function getDefaultConfiguration()  | 
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| 219 | |||
| 220 | /**  | 
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| 221 | * getConfiguration  | 
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| 222 | *  | 
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| 223 | * Return current configuration settings.  | 
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| 224 | *  | 
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| 225 | * @access public  | 
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| 226 | * @return array  | 
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| 227 | * @throws ConnectionException  | 
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| 228 | */  | 
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| 229 | public function getConfiguration()  | 
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| 244 | }  | 
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| 245 |