PHP实现的一致性HASH算法示例

<"%u", $hash * 33) + ord($s{$i});
      //$hash = ($hash * 33 + ord($s{$i})) & 0x7FFFFFFF;
      $hash = ($hash << $seed) + $hash + ord($s{$i});
    }
    return $hash & 0x7FFFFFFF;
  }
  /**
   * 增加节点
   * @param string $node 节点名称
   * @return object $this
   */
  public function addNode($node)
  {
    if (in_array($node, array_keys($this->nodes))) {
      return;
    }
    for ($i = 1; $i <= $this->virtual; $i++) {
      $key         = $this->time33($node . '-' . $i);
      $this->_ring[$key]  = $node;
      $this->nodes[$node][] = $key;
    }
    ksort($this->_ring, SORT_NUMERIC);
    return $this;
  }
  /**
   * 获取字符串的HASH在圆环上面映射到的节点
   * @param string $key
   * @return string $node
   */
  public function getNode($key)
  {
    $node = current($this->_ring);
    $hash = $this->time33($key);
    foreach ($this->_ring as $key => $value) {
      if ($hash <= $key) {
        $node = $value;
        break;
      }
    }
    return $node;
  }
  /**
   * 获取映射到特定节点的KEY
   * 此方法需手动调用，非特殊情况不建议程序中使用此方法
   * @param string $node
   * @param string $keyPre
   * @return mixed
   */
  public function getKey($node, $keyPre = ""){
    if(!in_array($node, array_keys($this->nodes))){
      return false;
    }
    $result = false;
    for($i=1;$i<=10000;$i++){
      $key = $keyPre . md5(rand(1000, 9999));
      if($this->getNode($key) == $node){
        $result = true;
        break;
      }
    }
    return $result "asofiwjamfdalksjfkasasdflasfja";
$key2 = "jaksldfjlasfjsdjfioafaslkjflsadkjfl";
$key3 = "asjldflkjasfsdjflkajkldsjfksajdlflajs";
$key4 = "iowanfasijfmasdnfoas";
$key5 = "pqkisndfhoalnfiewlkl";
$key6 = "qjklasjdifoajfalsjflsa";
echo sprintf("%-50s 映射到节点 %s\n", $key1, $ch_obj->getNode($key1));
echo sprintf("%-50s 映射到节点 %s\n", $key2, $ch_obj->getNode($key2));
echo sprintf("%-50s 映射到节点 %s\n", $key3, $ch_obj->getNode($key3));
echo sprintf("%-50s 映射到节点 %s\n", $key4, $ch_obj->getNode($key4));
echo sprintf("%-50s 映射到节点 %s\n", $key5, $ch_obj->getNode($key5));
echo sprintf("%-50s 映射到节点 %s\n", $key6, $ch_obj->getNode($key6));
// +----------------------------------------------------------------------
// | 查看圆环和节点信息
// +----------------------------------------------------------------------
// var_dump($ch_obj->getRing());
// var_dump($ch_obj->nodes);
// +----------------------------------------------------------------------
// | 获取特定节点的KEY
// +----------------------------------------------------------------------
// $key1 = $ch_obj->getKey('node_1', 'pre_');
// var_dump($key1);
// +----------------------------------------------------------------------
// | 测试分布
// +----------------------------------------------------------------------
// $keys = array();
// $rings = array();
// for ($i = 1; $i <= 60000; $i++) {
//   $key = sha1(rand(1000000,9999999));
//   $node = $ch_obj->getNode($key);
//   $rings[$node] = isset($rings[$node]) "htmlcode">

asofiwjamfdalksjfkasasdflasfja           映射到节点 node_1
jaksldfjlasfjsdjfioafaslkjflsadkjfl        映射到节点 node_2
asjldflkjasfsdjflkajkldsjfksajdlflajs       映射到节点 node_1
iowanfasijfmasdnfoas                映射到节点 node_2
pqkisndfhoalnfiewlkl                映射到节点 node_3
qjklasjdifoajfalsjflsa               映射到节点 node_5




PS：这里再为大家提供2款hash相关在线工具供大家参考使用：
在线散列/哈希算法加密工具：

http://tools.jb51.net/password/hash_encrypt
在线MD5/hash/SHA-1/SHA-2/SHA-256/SHA-512/SHA-3/RIPEMD-160加密工具：

http://tools.jb51.net/password/hash_md5_sha
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希望本文所述对大家PHP程序设计有所帮助。