Complex classes like FrameHandler 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 FrameHandler, and based on these observations, apply Extract Interface, too.
1 | <?php |
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14 | class FrameHandler { |
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15 | |||
16 | /** |
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17 | * The message buffer for data frames. |
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18 | * |
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19 | * @var string |
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20 | */ |
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21 | protected $buffer = ''; |
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22 | |||
23 | /** |
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24 | * @var WebSocketClient |
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25 | */ |
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26 | protected $client; |
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27 | |||
28 | /** |
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29 | * Resume opCode for the `CONTINUATION` handler. |
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30 | * |
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31 | * @var int|null |
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32 | */ |
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33 | protected $continue; |
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34 | |||
35 | /** |
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36 | * Max outgoing fragment size. |
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37 | * |
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38 | * Each browser has its own standard, so this is generalized. |
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39 | * |
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40 | * Defaults to 128 KiB. |
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41 | * |
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42 | * @var int |
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43 | */ |
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44 | protected $fragmentSize = 128 * 1024; |
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45 | |||
46 | /** |
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47 | * Maximum inbound message length (complete payload). |
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48 | * |
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49 | * Defaults to 10 MiB. |
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50 | * |
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51 | * @var int |
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52 | */ |
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53 | protected $maxLength = 10 * 1024 * 1024; |
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54 | |||
55 | /** |
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56 | * @var FrameReader |
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57 | */ |
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58 | protected $reader; |
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59 | |||
60 | /** |
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61 | * Whether binary I/O should bypass buffers. |
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62 | * |
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63 | * @var bool |
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64 | */ |
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65 | protected $stream = false; |
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66 | |||
67 | /** |
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68 | * @param WebSocketClient $client |
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69 | */ |
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70 | public function __construct (WebSocketClient $client) { |
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74 | |||
75 | /** |
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76 | * @return int |
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77 | */ |
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78 | public function getFragmentSize (): int { |
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81 | |||
82 | /** |
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83 | * @return int |
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84 | */ |
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85 | public function getMaxLength (): int { |
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88 | |||
89 | /** |
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90 | * @return bool |
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91 | */ |
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92 | public function isStream (): bool { |
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95 | |||
96 | /** |
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97 | * Progressively receives `BINARY` data into the buffer until the payload is complete. |
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98 | * Passes the complete payload up to {@link WebSocketClient::onBinary()} |
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99 | * |
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100 | * When {@link $stream} is `true`, this bypasses the buffer. |
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101 | * |
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102 | * @param Frame $frame |
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103 | * @throws WebSocketError |
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104 | */ |
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105 | protected function onBinary (Frame $frame): void { |
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119 | |||
120 | /** |
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121 | * When a `CLOSE` frame is received. Calls {@link WebSocketClient::onClose()} |
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122 | * |
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123 | * https://tools.ietf.org/html/rfc6455#section-5.5.1 |
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124 | * > If an endpoint receives a Close frame and did not previously send a |
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125 | * > Close frame, the endpoint MUST send a Close frame in response. (When |
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126 | * > sending a Close frame in response, the endpoint typically echos the |
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127 | * > status code it received.) |
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128 | * |
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129 | * @param Frame $frame |
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130 | */ |
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131 | protected function onClose (Frame $frame): void { |
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134 | |||
135 | /** |
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136 | * When a `CONTINUATION` frame (data fragment) is received. |
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137 | * |
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138 | * @param Frame $frame |
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139 | * @throws WebSocketError |
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140 | */ |
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141 | protected function onContinuation (Frame $frame): void { |
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163 | |||
164 | /** |
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165 | * When a control frame is received. |
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166 | * |
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167 | * https://tools.ietf.org/html/rfc6455#section-5.4 |
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168 | * > Control frames (see Section 5.5) MAY be injected in the middle of |
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169 | * > a fragmented message. |
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170 | * |
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171 | * @param Frame $frame |
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172 | */ |
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173 | protected function onControl (Frame $frame): void { |
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187 | |||
188 | /** |
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189 | * When an initial data frame (not `CONTINUATION`) is received. |
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190 | * |
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191 | * @param Frame $frame |
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192 | */ |
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193 | protected function onData (Frame $frame): void { |
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222 | |||
223 | /** |
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224 | * Validates the message length, but only when the buffer is in use. |
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225 | * |
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226 | * @param Frame $frame |
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227 | * @throws WebSocketError |
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228 | */ |
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229 | protected function onData_CheckLength (Frame $frame): void { |
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238 | |||
239 | /** |
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240 | * Called by {@link WebSocketClient} when a complete frame has been received. |
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241 | * |
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242 | * Delegates to the other handler methods using the program logic outlined in the RFC. |
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243 | * |
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244 | * Eventually calls back to the {@link WebSocketClient} when payloads are complete. |
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245 | * |
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246 | * @param Frame $frame |
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247 | */ |
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248 | public function onFrame (Frame $frame): void { |
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256 | |||
257 | /** |
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258 | * When a `PING` is received. Calls {@link WebSocketClient::onPing()} |
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259 | * |
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260 | * @param Frame $frame |
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261 | */ |
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262 | protected function onPing (Frame $frame): void { |
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265 | |||
266 | /** |
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267 | * When a `PONG` is received. Calls {@link WebSocketClient::onPong()} |
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268 | * |
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269 | * @param Frame $frame |
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270 | */ |
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271 | protected function onPong (Frame $frame): void { |
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274 | |||
275 | /** |
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276 | * Uses {@link FrameReader} to read frames and passes them off to {@link onFrame()} |
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277 | */ |
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278 | public function onReadable (): void { |
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283 | |||
284 | /** |
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285 | * Progressively receives `TEXT` data until the payload is complete. |
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286 | * Validates the complete payload as UTF-8 and passes it up to {@link WebSocketClient::onText()} |
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287 | * |
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288 | * @param Frame $frame |
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289 | * @throws WebSocketError |
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290 | */ |
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291 | protected function onText (Frame $frame): void { |
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303 | |||
304 | /** |
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305 | * @param int $bytes |
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306 | * @return $this |
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307 | */ |
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308 | public function setFragmentSize (int $bytes) { |
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312 | |||
313 | /** |
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314 | * @param int $bytes |
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315 | * @return $this |
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316 | */ |
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317 | public function setMaxLength (int $bytes) { |
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321 | |||
322 | /** |
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323 | * @param bool $stream |
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324 | * @return $this |
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325 | */ |
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326 | public function setStream (bool $stream) { |
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330 | |||
331 | /** |
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332 | * Sends a complete message to the peer, fragmenting if needed. |
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333 | * |
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334 | * @param int $opCode |
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335 | * @param string $payload |
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336 | */ |
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337 | public function write (int $opCode, string $payload): void { |
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349 | |||
350 | /** |
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351 | * @param string $payload |
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352 | */ |
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353 | public function writeBinary (string $payload): void { |
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356 | |||
357 | /** |
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358 | * @param int $code |
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359 | * @param string $reason |
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360 | */ |
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361 | public function writeClose (int $code = Frame::CLOSE_NORMAL, string $reason = ''): void { |
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364 | |||
365 | /** |
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366 | * Writes a single frame. |
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367 | * |
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368 | * @param bool $final |
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369 | * @param int $opCode |
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370 | * @param string $payload |
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371 | */ |
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372 | protected function writeFrame (bool $final, int $opCode, string $payload): void { |
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391 | |||
392 | /** |
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393 | * @param string $payload |
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394 | */ |
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395 | public function writePing (string $payload = ''): void { |
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398 | |||
399 | /** |
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400 | * @param string $payload |
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401 | */ |
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402 | public function writePong (string $payload = ''): void { |
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405 | |||
406 | /** |
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407 | * @param string $payload |
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408 | */ |
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409 | public function writeText (string $payload): void { |
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412 | } |
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
integer
values, zero is a special case, in particular the following results might be unexpected: