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 declare(strict_types=1); |
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34 | class ParallelExecutor |
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35 | { |
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36 | private $input; |
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37 | private $output; |
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38 | private $messenger; |
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39 | private $console; |
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40 | private $client; |
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41 | private $config; |
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42 | |||
43 | public function __construct( |
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59 | |||
60 | /** |
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61 | * @param Host[] $hosts |
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62 | */ |
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63 | private function connect(array $hosts) |
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90 | |||
91 | /** |
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92 | * @param Task[] $tasks |
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93 | * @param Host[] $hosts |
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94 | */ |
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95 | public function run(array $tasks, array $hosts): int |
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96 | { |
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97 | $this->persistHosts($hosts); |
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98 | $this->connect($hosts); |
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99 | |||
100 | $localhost = new Localhost(); |
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101 | $limit = (int)$this->input->getOption('limit') ?: count($hosts); |
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102 | |||
103 | foreach ($tasks as $task) { |
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104 | $this->messenger->startTask($task); |
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105 | |||
106 | if ($limit === 1 || count($hosts) === 1) { |
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107 | foreach ($hosts as $host) { |
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108 | $host->getConfig()->getCollection()->load(); |
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109 | $task->run(new Context($host, $this->input, $this->output)); |
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110 | $host->getConfig()->getCollection()->flush(); |
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111 | } |
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112 | } else { |
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113 | foreach (array_chunk($hosts, $limit) as $chunk) { |
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114 | $exitCode = $this->runTask($chunk, $task); |
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115 | if ($exitCode !== 0) { |
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116 | return $exitCode; |
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117 | } |
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118 | } |
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119 | } |
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120 | |||
121 | $this->messenger->endTask($task); |
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122 | } |
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123 | |||
124 | return 0; |
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125 | } |
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126 | |||
127 | private function runTask(array $hosts, Task $task): int |
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161 | |||
162 | protected function getProcess(Host $host, Task $task): Process |
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175 | |||
176 | /** |
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177 | * Start all of the processes. |
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178 | * |
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179 | * @param Process[] $processes |
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180 | * @return void |
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181 | */ |
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182 | protected function startProcesses(array $processes) |
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188 | |||
189 | /** |
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190 | * Determine if any of the processes are running. |
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191 | * |
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192 | * @param Process[] $processes |
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193 | * @return bool |
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194 | */ |
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195 | protected function areRunning(array $processes): bool |
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205 | |||
206 | /** |
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207 | * Gather the output from all of the processes. |
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208 | * |
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209 | * @param Process[] $processes |
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210 | * @param callable $callback |
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211 | * @return void |
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212 | */ |
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213 | protected function gatherOutput(array $processes, callable $callback) |
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227 | |||
228 | /** |
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229 | * Gather the cumulative exit code for the processes. |
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230 | */ |
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231 | protected function gatherExitCodes(array $processes): int |
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241 | |||
242 | /** |
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243 | * @param Host[] $hosts |
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244 | */ |
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245 | private function persistHosts(array $hosts) |
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261 | } |
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262 |
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVar
assignment in line 1 and the$higher
assignment in line 2 are dead. The first because$myVar
is never used and the second because$higher
is always overwritten for every possible time line.