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 RedisProxy 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 RedisProxy, and based on these observations, apply Extract Interface, too.
1 | <?php |
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23 | class RedisProxy |
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24 | { |
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25 | const DRIVER_REDIS = 'redis'; |
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26 | |||
27 | const DRIVER_PREDIS = 'predis'; |
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28 | |||
29 | private $driver; |
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30 | |||
31 | private $host; |
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32 | |||
33 | private $port; |
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34 | |||
35 | private $database = 0; |
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36 | |||
37 | private $timeout; |
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38 | |||
39 | private $supportedDrivers = [ |
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40 | self::DRIVER_REDIS, |
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41 | self::DRIVER_PREDIS, |
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42 | ]; |
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43 | |||
44 | private $driversOrder = []; |
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45 | |||
46 | 112 | public function __construct($host, $port, $timeout = null) |
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53 | |||
54 | 112 | public function setDriversOrder(array $driversOrder) |
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55 | { |
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56 | 112 | if (empty($driversOrder)) { |
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57 | 2 | throw new RedisProxyException('You need to set at least one driver'); |
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58 | } |
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59 | 110 | foreach ($driversOrder as $driver) { |
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60 | 110 | if (!in_array($driver, $this->supportedDrivers)) { |
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61 | 110 | throw new RedisProxyException('Driver "' . $driver . '" is not supported'); |
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62 | } |
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63 | } |
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64 | 108 | $this->driversOrder = $driversOrder; |
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65 | 108 | return $this; |
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66 | } |
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67 | |||
68 | 108 | private function init() |
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73 | |||
74 | 108 | private function prepareDriver() |
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75 | { |
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76 | 108 | if ($this->driver !== null) { |
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77 | 108 | return; |
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78 | } |
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79 | |||
80 | 108 | foreach ($this->driversOrder as $preferredDriver) { |
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81 | 108 | if ($preferredDriver === self::DRIVER_REDIS && extension_loaded('redis')) { |
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82 | 54 | $this->driver = new Redis(); |
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83 | 54 | return; |
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84 | } |
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85 | 54 | if ($preferredDriver === self::DRIVER_PREDIS && class_exists('Predis\Client')) { |
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86 | 54 | $this->driver = new Client(); |
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87 | 54 | return; |
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88 | } |
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89 | } |
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90 | throw new RedisProxyException('No redis library loaded (ext-redis or predis)'); |
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91 | } |
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92 | |||
93 | 108 | private function connect($host, $port, $timeout = null) |
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97 | |||
98 | 108 | private function isConnected() |
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102 | |||
103 | 108 | public function __call($name, $arguments) |
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114 | |||
115 | /** |
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116 | * @param integer $database |
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117 | * @return boolean true on success |
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118 | * @throws RedisProxyException on failure |
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119 | */ |
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120 | 108 | public function select($database) |
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121 | { |
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122 | 108 | $this->prepareDriver(); |
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123 | 108 | if (!$this->isConnected()) { |
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124 | 108 | $this->connect($this->host, $this->port, $this->timeout); |
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125 | } |
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126 | 108 | if ($database == $this->database) { |
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127 | 108 | return true; |
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128 | } |
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129 | try { |
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130 | 12 | $result = $this->driver->select($database); |
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131 | 2 | } catch (Exception $e) { |
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132 | 2 | throw new RedisProxyException('Invalid DB index'); |
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133 | } |
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134 | 10 | $result = $this->transformResult($result); |
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135 | 10 | if ($result === false) { |
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136 | 2 | throw new RedisProxyException('Invalid DB index'); |
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137 | } |
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138 | 8 | $this->database = $database; |
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139 | 8 | return $result; |
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140 | } |
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141 | |||
142 | /** |
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143 | * @param string|null $section |
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144 | * @return array |
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145 | */ |
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146 | 8 | public function info($section = null) |
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162 | |||
163 | /** |
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164 | * Set multiple values to multiple keys |
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165 | * @param array $dictionary |
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166 | * @return boolean true on success |
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167 | * @throws RedisProxyException if number of arguments is wrong |
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168 | */ |
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169 | 12 | public function mset(...$dictionary) |
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170 | { |
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171 | 12 | if (is_array($dictionary[0])) { |
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172 | 8 | $result = $this->driver->mset(...$dictionary); |
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173 | 8 | return $this->transformResult($result); |
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174 | } |
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175 | 8 | $dictionary = $this->prepareKeyValue($dictionary, 'mset'); |
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176 | 4 | $result = $this->driver->mset($dictionary); |
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177 | 4 | return $this->transformResult($result); |
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178 | } |
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179 | |||
180 | /** |
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181 | * @param string $key |
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182 | * @return string|null null if hash field is not set |
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183 | */ |
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184 | 16 | public function get($key) |
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190 | |||
191 | /** |
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192 | * Delete a key(s) |
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193 | * @param array ...$keys |
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194 | * @return integer number of deleted keys |
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195 | */ |
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196 | 20 | public function del(...$keys) |
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201 | |||
202 | /** |
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203 | * Delete a key(s) |
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204 | * @param array ...$keys |
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205 | * @return integer number of deleted keys |
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206 | */ |
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207 | 8 | public function delete(...$keys) |
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211 | |||
212 | /** |
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213 | * Incrementally iterate the keys space |
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214 | * @param mixed $iterator iterator / cursor, use $iterator = null for start scanning, when $iterator is changed to 0 or '0', scanning is finished |
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215 | * @param string $pattern pattern for keys, use * as wild card |
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216 | * @param integer $count |
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217 | * @return array|boolean|null list of found keys, returns null if $iterator is 0 or '0' |
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218 | */ |
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219 | 4 | View Code Duplication | public function scan(&$iterator, $pattern = null, $count = null) |
220 | { |
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221 | 4 | if ((string)$iterator === '0') { |
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222 | 4 | return null; |
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223 | } |
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224 | 4 | $this->init(); |
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225 | 4 | if ($this->driver instanceof Client) { |
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226 | 2 | $returned = $this->driver->scan($iterator, ['match' => $pattern, 'count' => $count]); |
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227 | 2 | $iterator = $returned[0]; |
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228 | 2 | return $returned[1]; |
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229 | } |
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230 | 2 | return $this->driver->scan($iterator, $pattern, $count); |
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231 | } |
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232 | |||
233 | /** |
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234 | * Get the value of a hash field |
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235 | * @param string $key |
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236 | * @param string $field |
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237 | * @return string|null null if hash field is not set |
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238 | */ |
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239 | 16 | public function hget($key, $field) |
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245 | |||
246 | /** |
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247 | * Delete one or more hash fields, returns number of deleted fields |
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248 | * @param array $key |
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249 | * @param array ...$fields |
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250 | * @return integer |
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251 | */ |
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252 | 8 | public function hdel($key, ...$fields) |
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253 | { |
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254 | 8 | if (is_array($fields[0])) { |
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255 | 4 | $fields = $fields[0]; |
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256 | } |
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257 | 8 | return $this->driver->hdel($key, ...$fields); |
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258 | } |
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259 | |||
260 | /** |
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261 | * Increment the integer value of hash field by given number |
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262 | * @param string $key |
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263 | * @param string $field |
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264 | * @param integer $increment |
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265 | * @return integer |
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266 | */ |
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267 | 4 | public function hincrby($key, $field, $increment = 1) |
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271 | |||
272 | /** |
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273 | * Increment the float value of hash field by given amount |
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274 | * @param string $key |
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275 | * @param string $field |
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276 | * @param float $increment |
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277 | * @return float |
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278 | */ |
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279 | 4 | public function hincrbyfloat($key, $field, $increment = 1) |
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283 | |||
284 | /** |
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285 | * Set multiple values to multiple hash fields |
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286 | * @param string $key |
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287 | * @param array $dictionary |
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288 | * @return boolean true on success |
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289 | * @throws RedisProxyException if number of arguments is wrong |
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290 | */ |
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291 | 12 | public function hmset($key, ...$dictionary) |
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301 | |||
302 | /** |
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303 | * Incrementally iterate hash fields and associated values |
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304 | * @param string $key |
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305 | * @param mixed $iterator iterator / cursor, use $iterator = null for start scanning, when $iterator is changed to 0 or '0', scanning is finished |
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306 | * @param string $pattern pattern for fields, use * as wild card |
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307 | * @param integer $count |
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308 | * @return array|boolean|null list of found fields with associated values, returns null if $iterator is 0 or '0' |
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309 | */ |
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310 | 4 | View Code Duplication | public function hscan($key, &$iterator, $pattern = null, $count = null) |
323 | |||
324 | /** |
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325 | * Add one or more members to a set |
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326 | * @param string $key |
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327 | * @param array ...$members |
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328 | * @return integer number of new members added to set |
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329 | */ |
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330 | 12 | public function sadd($key, ...$members) |
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337 | |||
338 | /** |
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339 | * Remove and return one or multiple random members from a set |
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340 | * @param string $key |
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341 | * @param integer $count number of members |
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342 | * @return mixed string if $count is null or 1 and $key exists, array if $count > 1 and $key exists, null if $key doesn't exist |
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343 | */ |
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344 | 4 | public function spop($key, $count = 1) |
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361 | |||
362 | /** |
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363 | * Incrementally iterate Set elements |
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364 | * @param string $key |
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365 | * @param mixed $iterator iterator / cursor, use $iterator = null for start scanning, when $iterator is changed to 0 or '0', scanning is finished |
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366 | * @param string $pattern pattern for member's values, use * as wild card |
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367 | * @param integer $count |
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368 | * @return array|boolean|null list of found members, returns null if $iterator is 0 or '0' |
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369 | */ |
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370 | 4 | View Code Duplication | public function sscan($key, &$iterator, $pattern = null, $count = null) |
383 | |||
384 | 36 | private function convertFalseToNull($result) |
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388 | |||
389 | 108 | private function transformResult($result) |
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396 | |||
397 | /** |
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398 | * Create array from input array - odd keys are used as keys, even keys are used as values |
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399 | * @param array $dictionary |
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400 | * @param string $command |
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401 | * @return array |
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402 | * @throws RedisProxyException if number of keys is not the same as number of values |
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403 | */ |
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404 | 16 | private function prepareKeyValue(array $dictionary, $command) |
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418 | } |
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419 |