code: function _parseStorage(body, charset, hasPathIndex) {
      var result = {}
  
      var group = helpers.trim(body.toString(charset, 0, protocol.FDFS_GROUP_NAME_MAX_LEN))
      var ip = helpers.trim(body.toString(charset, protocol.FDFS_GROUP_NAME_MAX_LEN, protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1))
      var port = Number('0x' + body.toString('hex',
          protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1,
          protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1 + protocol.FDFS_PROTO_PKG_LEN_SIZE))
  
      result.group = group
      result.host = ip
      result.port = port
  
      if (hasPathIndex &&
          body.length > protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1 + protocol.FDFS_PROTO_PKG_LEN_SIZE) {
          var storePathIndex = Number('0x' + body.toString('hex',
              protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1 + protocol.FDFS_PROTO_PKG_LEN_SIZE,
              protocol.FDFS_GROUP_NAME_MAX_LEN + protocol.FDFS_IPADDR_SIZE - 1 + protocol.FDFS_PROTO_PKG_LEN_SIZE + 1))
  
          result.storePathIndex = storePathIndex
      }
  
      return result
  }
docs: -------------- helper methods 
  @ FDFS_GROUP_NAME_MAX_LEN bytes: group name
  @ FDFS_IPADDR_SIZE - 1 bytes: storage server ip address
  @ FDFS_PROTO_PKG_LEN_SIZE bytes: storage server port
  @1 byte: store path index on the storage server {可以没有这个字节}
  
  @param {Buffer} body
  @param {String} charset
  @param {Boolean} hasPathIndex
  @private {Object}