| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | namespace Thruster\Component\SocketClient; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | use Thruster\Component\EventLoop\EventLoopInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  | use Thruster\Component\Stream\DuplexStreamInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | use Thruster\Component\Stream\Stream; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | use Thruster\Component\Stream\WritableStreamInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  * Class SecureStream | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  * @package Thruster\Component\SocketClient | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  |  * @author  Aurimas Niekis <[email protected]> | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  | class SecureStream extends Stream implements DuplexStreamInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |      * @var Stream | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |     private $decorating; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |     public function __construct(Stream $stream, EventLoopInterface $loop) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |         $this->stream     = $stream->stream; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |         $this->decorating = $stream; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |         $this->loop       = $loop; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |         $stream->on('error', function ($error) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |             $this->emit('error', [$error, $this]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |         }); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |         $stream->on('end', function () { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |             $this->emit('end', [$this]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |         }); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |         $stream->on('close', function () { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |             $this->emit('close', [$this]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 |  |  |         }); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |         $stream->on('drain', function () { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |             $this->emit('drain', [$this]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |         }); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |         $stream->pause(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |         $this->resume(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |     public function handleData($stream) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |         $data = stream_get_contents($stream); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |         $this->emit('data', [$data, $this]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |         if (false === is_resource($stream) || feof($stream)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |             $this->end(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |      * @return Stream | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |     public function getDecorating() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |         return $this->decorating; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |     public function pause() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |         $this->loop->removeReadStream($this->decorating->stream); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |     public function resume() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |         if ($this->isReadable()) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 |  |  |             $this->loop->addReadStream($this->decorating->stream, [$this, 'handleData']); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |     public function isReadable() : bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |         return $this->decorating->isReadable(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |     public function isWritable() : bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |         return $this->decorating->isWritable(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |     public function write($data) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 |  |  |         return $this->decorating->write($data); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |     public function close() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 |  |  |         return $this->decorating->close(); | 
                            
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                | 99 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 100 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 101 |  |  |     public function end($data = null) | 
            
                                                                        
                            
            
                                    
            
            
                | 102 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 103 |  |  |         return $this->decorating->end($data); | 
                            
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                | 104 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 |  |  |     public function pipe(WritableStreamInterface $destination, array $options = []) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |         $this->pipeAll($this, $destination, $options); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |         return $destination; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 112 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 113 |  |  |  | 
            
                        
If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.
Let’s take a look at an example:
Our function
my_functionexpects aPostobject, and outputs the author of the post. The base classPostreturns a simple string and outputting a simple string will work just fine. However, the child classBlogPostwhich is a sub-type ofPostinstead decided to return anobject, and is therefore violating the SOLID principles. If aBlogPostwere passed tomy_function, PHP would not complain, but ultimately fail when executing thestrtouppercall in its body.