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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25 | class RedisProxy |
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26 | { |
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27 | const DRIVER_REDIS = 'redis'; |
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28 | |||
29 | const DRIVER_PREDIS = 'predis'; |
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30 | |||
31 | private $driver; |
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32 | |||
33 | private $host; |
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34 | |||
35 | private $port; |
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36 | |||
37 | private $database = 0; |
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38 | |||
39 | private $timeout; |
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40 | |||
41 | private $supportedDrivers = [ |
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42 | self::DRIVER_REDIS, |
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43 | self::DRIVER_PREDIS, |
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44 | ]; |
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45 | |||
46 | private $driversOrder = []; |
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47 | |||
48 | 112 | public function __construct($host, $port, $timeout = null) |
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55 | |||
56 | 112 | public function setDriversOrder(array $driversOrder) |
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69 | |||
70 | 108 | private function init() |
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75 | |||
76 | 108 | private function prepareDriver() |
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94 | |||
95 | 108 | private function connect($host, $port, $timeout = null) |
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99 | |||
100 | 108 | private function isConnected() |
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104 | |||
105 | 108 | public function __call($name, $arguments) |
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116 | |||
117 | /** |
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118 | * @param integer $database |
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119 | * @return boolean true on success |
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120 | * @throws RedisProxyException on failure |
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121 | */ |
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122 | 108 | public function select($database) |
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123 | { |
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124 | 108 | $this->prepareDriver(); |
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125 | 108 | if (!$this->isConnected()) { |
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126 | 108 | $this->connect($this->host, $this->port, $this->timeout); |
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127 | } |
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128 | 108 | if ($database == $this->database) { |
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129 | 108 | return true; |
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130 | } |
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131 | try { |
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132 | 12 | $result = $this->driver->select($database); |
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133 | 2 | } catch (Exception $e) { |
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134 | 2 | throw new RedisProxyException('Invalid DB index'); |
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135 | } |
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136 | 10 | $result = $this->transformResult($result); |
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137 | 10 | if ($result === false) { |
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138 | 2 | throw new RedisProxyException('Invalid DB index'); |
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139 | } |
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140 | 8 | $this->database = $database; |
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141 | 8 | return $result; |
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142 | } |
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143 | |||
144 | /** |
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145 | * @param string|null $section |
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146 | * @return array |
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147 | */ |
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148 | 8 | public function info($section = null) |
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164 | |||
165 | /** |
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166 | * Set multiple values to multiple keys |
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167 | * @param array $dictionary |
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168 | * @return boolean true on success |
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169 | * @throws RedisProxyException if number of arguments is wrong |
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170 | */ |
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171 | 12 | View Code Duplication | public function mset(...$dictionary) |
182 | |||
183 | /** |
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184 | * @param string $key |
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185 | * @return string|null null if hash field is not set |
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186 | */ |
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187 | 16 | public function get($key) |
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193 | |||
194 | /** |
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195 | * Delete a key(s) |
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196 | * @param array $keys |
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197 | * @return integer number of deleted keys |
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198 | */ |
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199 | 20 | public function del(...$keys) |
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204 | |||
205 | /** |
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206 | * Delete a key(s) |
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207 | * @param array $keys |
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208 | * @return integer number of deleted keys |
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209 | */ |
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210 | 8 | public function delete(...$keys) |
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214 | |||
215 | /** |
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216 | * Incrementally iterate the keys space |
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217 | * @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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218 | * @param string $pattern pattern for keys, use * as wild card |
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219 | * @param integer $count |
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220 | * @return array|boolean|null list of found keys, returns null if $iterator is 0 or '0' |
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221 | */ |
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222 | 4 | View Code Duplication | public function scan(&$iterator, $pattern = null, $count = null) |
235 | |||
236 | /** |
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237 | * Get the value of a hash field |
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238 | * @param string $key |
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239 | * @param string $field |
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240 | * @return string|null null if hash field is not set |
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241 | */ |
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242 | 16 | public function hget($key, $field) |
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248 | |||
249 | /** |
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250 | * Delete one or more hash fields, returns number of deleted fields |
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251 | * @param array $key |
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252 | * @param array $fields |
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253 | * @return integer |
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254 | */ |
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255 | 8 | public function hdel($key, ...$fields) |
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256 | { |
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257 | 8 | $this->init(); |
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258 | 8 | if (is_array($fields[0])) { |
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259 | 4 | $fields = $fields[0]; |
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260 | } |
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261 | 8 | return $this->driver->hdel($key, ...$fields); |
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262 | } |
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263 | |||
264 | /** |
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265 | * Increment the integer value of hash field by given number |
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266 | * @param string $key |
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267 | * @param string $field |
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268 | * @param integer $increment |
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269 | * @return integer |
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270 | */ |
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271 | 4 | public function hincrby($key, $field, $increment = 1) |
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276 | |||
277 | /** |
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278 | * Increment the float value of hash field by given amount |
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279 | * @param string $key |
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280 | * @param string $field |
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281 | * @param float $increment |
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282 | * @return float |
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283 | */ |
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284 | 4 | public function hincrbyfloat($key, $field, $increment = 1) |
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289 | |||
290 | /** |
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291 | * Set multiple values to multiple hash fields |
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292 | * @param string $key |
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293 | * @param array $dictionary |
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294 | * @return boolean true on success |
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295 | * @throws RedisProxyException if number of arguments is wrong |
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296 | */ |
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297 | 12 | View Code Duplication | public function hmset($key, ...$dictionary) |
308 | |||
309 | /** |
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310 | * Incrementally iterate hash fields and associated values |
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311 | * @param string $key |
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312 | * @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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313 | * @param string $pattern pattern for fields, use * as wild card |
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314 | * @param integer $count |
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315 | * @return array|boolean|null list of found fields with associated values, returns null if $iterator is 0 or '0' |
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316 | */ |
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317 | 4 | View Code Duplication | public function hscan($key, &$iterator, $pattern = null, $count = null) |
330 | |||
331 | /** |
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332 | * Add one or more members to a set |
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333 | * @param string $key |
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334 | * @param array $members |
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335 | * @return integer number of new members added to set |
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336 | */ |
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337 | 12 | public function sadd($key, ...$members) |
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338 | { |
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339 | 12 | $this->init(); |
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340 | 12 | if (is_array($members[0])) { |
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341 | 8 | $members = $members[0]; |
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342 | } |
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343 | 12 | return $this->driver->sadd($key, ...$members); |
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344 | } |
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345 | |||
346 | /** |
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347 | * Remove and return one or multiple random members from a set |
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348 | * @param string $key |
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349 | * @param integer $count number of members |
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350 | * @return mixed string if $count is null or 1 and $key exists, array if $count > 1 and $key exists, null if $key doesn't exist |
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351 | */ |
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352 | 4 | public function spop($key, $count = 1) |
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353 | { |
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354 | 4 | $this->init(); |
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355 | 4 | if ($count == 1 || $count === null) { |
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356 | 4 | $result = $this->driver->spop($key); |
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357 | 4 | return $this->convertFalseToNull($result); |
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358 | } |
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359 | |||
360 | 4 | $members = []; |
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361 | 4 | for ($i = 0; $i < $count; ++$i) { |
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362 | 4 | $member = $this->driver->spop($key); |
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363 | 4 | if (!$member) { |
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364 | 4 | break; |
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365 | } |
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366 | 4 | $members[] = $member; |
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367 | } |
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368 | 4 | return empty($members) ? null : $members; |
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369 | } |
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370 | |||
371 | /** |
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372 | * Incrementally iterate Set elements |
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373 | * @param string $key |
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374 | * @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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375 | * @param string $pattern pattern for member's values, use * as wild card |
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376 | * @param integer $count |
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377 | * @return array|boolean|null list of found members, returns null if $iterator is 0 or '0' |
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378 | */ |
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379 | 4 | View Code Duplication | public function sscan($key, &$iterator, $pattern = null, $count = null) |
392 | |||
393 | 36 | private function convertFalseToNull($result) |
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397 | |||
398 | 108 | private function transformResult($result) |
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399 | { |
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400 | 108 | if ($this->driver instanceof Client && $result instanceof Status) { |
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401 | 54 | $result = $result->getPayload() === 'OK'; |
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402 | } |
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403 | 108 | return $result; |
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404 | } |
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405 | |||
406 | /** |
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407 | * Create array from input array - odd keys are used as keys, even keys are used as values |
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408 | * @param array $dictionary |
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409 | * @param string $command |
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410 | * @return array |
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411 | * @throws RedisProxyException if number of keys is not the same as number of values |
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412 | */ |
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413 | 16 | private function prepareKeyValue(array $dictionary, $command) |
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427 | } |
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428 |