<?php 

declare (strict_types = 1);

namespace app\common\model;
	
class  ConsistentHash {

		protected $nodes = array();

		protected $virtualNodes = array();

		protected $isSort = false;

		protected $virtualNodesNum = 10;

		public function __construct(){

		}
	
		public function setVirtualNum($num){
			$this->virtualNodesNum = $num;
		}

		public function addNode($node){
			$this->nodes[] = $node;
			for($i=0;$i<$this->virtualNodesNum;$i++){
				$virtualHash = sprintf('%u',crc32($node.$i));
				$this->virtualNodes[$virtualHash] = $node;
			}
		}

		public function addNodes($nodes){
			foreach($nodes as $node){
				 $this->addNode($node);
			}
		}	
		

		public function getNode($key){
			if(!$this->isSort){
				ksort($this->virtualNodes);
				$this->sort = true;
			}
			$hashKey = sprintf("%u",crc32($key));
			foreach($this->virtualNodes as $hash=>$node){
				//环中比当前值大的那个节点
				if($hash>$hashKey){
					return $node;
				}
			}
			return $node[0];
		}
		
	}

?>