Complex classes like PostgreSQL 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 PostgreSQL, and based on these observations, apply Extract Interface, too.
1 | <?php |
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9 | class PostgreSQL extends _Abstract { |
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10 | /** |
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11 | * @var resource DB connection handler |
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12 | */ |
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13 | protected $handler; |
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14 | /** |
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15 | * @var resource |
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16 | */ |
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17 | protected $query_result; |
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18 | /** |
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19 | * @inheritdoc |
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20 | */ |
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21 | function __construct ($database, $user = '', $password = '', $host = 'localhost', $prefix = '') { |
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22 | $start = microtime(true); |
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23 | /** |
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24 | * Parsing of $host variable, detecting port and persistent connection |
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25 | */ |
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26 | list($host, $port, $persistent) = $this->get_host_port_and_persistent($host); |
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27 | $connection_string = "host=$host port=$port dbname=$database user=$user password=$password options='--client_encoding=UTF8'"; |
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28 | $this->handler = $persistent ? pg_connect($connection_string) : pg_pconnect($connection_string); |
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29 | if (!is_resource($this->handler)) { |
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30 | return; |
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31 | } |
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32 | $this->database = $database; |
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33 | $this->connected = true; |
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34 | $this->connecting_time = microtime(true) - $start; |
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35 | $this->db_type = 'postgresql'; |
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36 | $this->prefix = $prefix; |
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37 | } |
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38 | /** |
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39 | * Parse host string into host, port and persistent separately |
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40 | * |
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41 | * Understands `p:` prefix for persistent connections |
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42 | * |
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43 | * @param string $host_string |
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44 | * |
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45 | * @return array |
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46 | */ |
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47 | protected function get_host_port_and_persistent ($host_string) { |
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69 | /** |
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70 | * @inheritdoc |
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71 | */ |
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72 | function q ($query, $params = [], ...$param) { |
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113 | /** |
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114 | * @inheritdoc |
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115 | * |
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116 | * @return false|resource |
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117 | */ |
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118 | protected function q_internal ($query) { |
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124 | /** |
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125 | * @inheritdoc |
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126 | */ |
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127 | protected function q_multi_internal ($query) { |
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130 | /** |
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131 | * @inheritdoc |
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132 | * |
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133 | * @param false|resource $query_result |
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134 | */ |
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135 | function f ($query_result, $single_column = false, $array = false, $indexed = false) { |
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151 | /** |
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152 | * @inheritdoc |
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153 | */ |
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154 | function id () { |
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157 | /** |
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158 | * @inheritdoc |
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159 | */ |
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160 | function affected () { |
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163 | /** |
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164 | * @inheritdoc |
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165 | * |
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166 | * @param false|resource $query_result |
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167 | */ |
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168 | function free ($query_result) { |
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174 | /** |
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175 | * @inheritdoc |
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176 | */ |
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177 | function columns ($table, $like = false) { |
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199 | /** |
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200 | * @inheritdoc |
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201 | */ |
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202 | function tables ($like = false) { |
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222 | /** |
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223 | * @inheritdoc |
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224 | */ |
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225 | protected function s_internal ($string, $single_quotes_around) { |
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228 | /** |
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229 | * @inheritdoc |
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230 | */ |
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231 | function server () { |
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234 | /** |
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235 | * @inheritdoc |
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236 | */ |
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237 | function __destruct () { |
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243 | } |
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244 |