| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | namespace Puzzle\AMQP\Messages\Bodies; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | use Puzzle\AMQP\Messages\Body; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  | use Puzzle\AMQP\Messages\Chunks\Chunk; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | use Puzzle\AMQP\Messages\Chunks\ChunkedMessageMetadata; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | use Puzzle\ValueObjects\Uuid; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  | use Puzzle\AMQP\Messages\ContentType; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | use Puzzle\AMQP\Messages\Chunks\ChunkSize; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  | class StreamedFile implements Body | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  |     private | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |         $filepath, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |         $chunkSize, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |         $metadata; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 | 5 |  |     public function __construct($filepath, ChunkSize $chunkSize = null) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 | 5 |  |         $this->ensureFilepathIsValid($filepath); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 | 4 |  |         $this->filepath = $filepath; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 | 4 |  |         $this->chunkSize = $chunkSize; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 | 4 |  |         $this->metadata = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 | 4 |  |         if($chunkSize instanceof ChunkSize) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 | 4 |  |         { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 | 1 |  |             $size = filesize($filepath); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 | 1 |  |             $nbChunks = (int) ceil($size / $chunkSize->toBytes()); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 | 1 |  |             $this->metadata = new ChunkedMessageMetadata(new Uuid(), $size, $nbChunks, sha1_file($filepath)); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 | 1 |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 | 4 |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 | 5 |  |     private function ensureFilepathIsValid($filepath) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 | 5 |  |         if(is_file($filepath) === false || is_readable($filepath) === false) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 | 5 |  |         { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 | 1 |  |             throw new \InvalidArgumentException("Cannot read $filepath"); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 | 4 |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 | 1 |  |     public function inOriginalFormat() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 | 1 |  |         return file_get_contents($this->filepath); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 | 2 |  |     public function asTransported() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 | 2 |  |         if($this->isChunked() === false) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 | 2 |  |         { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 | 1 |  |             return $this->inOriginalFormat(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 | 1 |  |         return $this->asTransportedInChunks(); | 
                            
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                | 58 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |      * @return \Generator | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 62 |  |  |      */ | 
            
                                                                        
                            
            
                                    
            
            
                | 63 | 1 |  |     private function asTransportedInChunks() | 
            
                                                                        
                            
            
                                    
            
            
                | 64 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 65 | 1 |  |         $offset = 0; | 
            
                                                                        
                            
            
                                    
            
            
                | 66 | 1 |  |         $playhead = 0; | 
            
                                                                        
                            
            
                                    
            
            
                | 67 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 68 | 1 |  |         $stream = fopen($this->filepath, 'r'); | 
            
                                                                        
                            
            
                                    
            
            
                | 69 |  |  |  | 
            
                                                                        
                            
            
                                                                    
                                                                                                        
            
            
                | 70 | 1 | View Code Duplication |         while(! feof($stream)) | 
                            
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                | 71 |  |  |         { | 
            
                                                                        
                            
            
                                    
            
            
                | 72 | 1 |  |             $content = fread($stream, $this->chunkSize->toBytes()); | 
            
                                                                        
                            
            
                                    
            
            
                | 73 | 1 |  |             $playhead++; | 
            
                                                                        
                            
            
                                    
            
            
                | 74 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 75 | 1 |  |             $chunk = new Chunk($playhead, $offset, $content, $this->metadata); | 
                            
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                | 76 | 1 |  |             yield $chunk; | 
            
                                                                        
                            
            
                                    
            
            
                | 77 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 78 | 1 |  |             $offset += $chunk->size(); | 
            
                                                                        
                            
            
                                    
            
            
                | 79 | 1 |  |             unset($chunk, $content); | 
            
                                                                        
                            
            
                                    
            
            
                | 80 | 1 |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 81 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 82 | 1 |  |         fclose($stream); | 
            
                                                                        
                            
            
                                    
            
            
                | 83 | 1 |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 | 3 |  |     public function getContentType() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 | 3 |  |         return ContentType::BINARY; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 | 1 |  |     public function __toString() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 | 1 |  |         return sprintf( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 | 1 |  |             '<binary stream of %d bytes>', | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 | 1 |  |             filesize($this->filepath) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 | 1 |  |         ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 | 4 |  |     public function isChunked() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 | 4 |  |         return $this->chunkSize instanceof ChunkSize; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 102 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 103 |  |  |  | 
            
                        
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.