Principle and implementation of a distributed hashing algorithm with Memcached consistency [PHP implementation]

1<?PHP2 3 Header("Content-type:text/html;charset=utf-8");4 5 Interfacehash{6 7      Public function_hash ($str);8 }9 Interfacedistribution{Ten  One      Public functionLookup$key); A } - /**** - principle and implementation of uniform hash distributed algorithm [PHP implementation] the **/ - classConsistentImplementsHashdistribution{ -     #Store the actual node -     protected $_nodes=Array(); +     #define the number of virtual nodes -     protected $mul=64; +     #defines a location where an array of records nodes are located A     protected $_position=Array(); at     #figure out the node -      Public function_hash ($str){ -         return sprintf('%u ',CRC32($str));//An integer that turns a string into a 32-bit sign -     } -     #core Functions -      Public functionLookup$key){ in         #figure out the current node -         $point=$this->_hash ($key); to         $node= Current($this->_position);//take the smallest node on the ring first +         #Loop so node -         foreach($this->_nodes as $k=$v){ the             #find the number of nodes where the current node is located, if no description is found is greater than so the node is on the smallest node *             if($point<=$k){ $                $node=$v;Panax Notoginseng                 Break; -             } the         } +         return $node; A     } the     #Add a node +      Public functionAddNode ($node){ -         #store in array go to Arrar ([Key=>val]) $ //$this->_nodes[$this->_hash ($node)]= $node; $          for($i= 0;$i<$this->mul;$i++) {  -             $this->_position[$this->_hash ($node.‘ -‘.$i)]=$node; -         } the         $this-_sortnode (); - Wuyi     } the     #Delete a node -      Public functionDelnode ($node){ Wu         foreach($this->_position as $k=$v) { -             if($v==$node){ About                 unset($this->_position[$k]); $             } -         } -     } -     #Sort A     protected function_sortnode () { +         #sort_regular Sort by key size the         Ksort($this->_position,sort_regular); -     } $     #Print out all the virtual nodes the      Public functiongetnodes () { the         Var_dump($this-_position); the     } the } - $con=Newconsistent (); in $con->addnode (' a '); the $con->addnode (' B '); the $con->addnode (' C '); About  the  the Echo' Currently so the server is as follows:<br/> '; the  $con-getnodes (); + Echo' <br/> the current build calculation of the HSAs landing is '.$con->_hash (' name '). ' <br/> '; - Echo' Name '. ' In the '.$con->lookup (' name '). ' Node ';

Principle and implementation of a distributed hashing algorithm with Memcached consistency [PHP implementation]