小程序缓存过期

jxcatSetStorageSync: function(key, value) {
    wx.setStorageSync(key, value)
    var timestamp = new Date().getTime()
    // 设置8小时后过期
    var remove_time = 3600000 * 8 + timestamp
    wx.setStorageSync(key + 'remove', remove_time)
  },
  jxcatGetStorageSync: function(key, value) {
    var remove_time = wx.getStorageSync(key + 'remove')
    var timestamp = new Date().getTime()
    var res = ''
    if (timestamp > remove_time) {
      // 过期
      wx.removeStorageSync(key)
    } else {
      res = wx.getStorageSync(key)
    }
    return res
  }