144 lines
4.9 KiB
C#
144 lines
4.9 KiB
C#
using System;
|
||
using System.Collections.Generic;
|
||
using System.Linq;
|
||
using System.Text;
|
||
using Newtonsoft.Json;
|
||
using System.Web;
|
||
|
||
namespace Common
|
||
{
|
||
/// <summary>
|
||
/// 记录每次（总次数设定上限，超过要求的频率即可）访问的时间，比较当前访问时间与向前指定次数那次的访问时间，如果时间短于规定的时长，则表示已经超过规定时长内访问次数了，即访问过于频繁了。
|
||
/// 如：public static FrequencyControler DoFrequency = new FrequencyControler("act", 10, 3);//定义访问控制器允许10秒内3次请求
|
||
/// DoFrequency.IsTooFrequently(true)//访问过于频繁！
|
||
/// </summary>
|
||
public class FrequencyControler
|
||
{
|
||
/// <summary>
|
||
/// 访问控制器名称，用于区分其它控制器，支持多个控制器
|
||
/// </summary>
|
||
private string Name { get; set; }
|
||
/// <summary>
|
||
/// 限定时长
|
||
/// </summary>
|
||
private int Seconds { get; set; }
|
||
/// <summary>
|
||
/// 限定次数
|
||
/// </summary>
|
||
private int Times { get; set; }
|
||
|
||
public readonly int MAX_TIMES = 100;
|
||
|
||
#region 私有方法
|
||
private string SessionNameDatelist
|
||
{
|
||
get { return String.Format("fc.{0}.datelist", Name); }
|
||
}
|
||
|
||
private string SessionNameDatepos
|
||
{
|
||
get { return String.Format("fc.{0}.datepos", Name); }
|
||
}
|
||
|
||
/// <summary>
|
||
/// 取得用于保存每次访问时间点的数组（做队列用）
|
||
/// </summary>
|
||
/// <returns></returns>
|
||
private long[] GetDateList()
|
||
{
|
||
if (HttpContext.Current.Session[SessionNameDatelist] == null)
|
||
{
|
||
HttpContext.Current.Session[SessionNameDatelist] = new long[MAX_TIMES];
|
||
}
|
||
return (long[])HttpContext.Current.Session[SessionNameDatelist];
|
||
}
|
||
|
||
/// <summary>
|
||
/// 获取时间记录位置，相当于当前队列位置
|
||
/// </summary>
|
||
/// <returns></returns>
|
||
private int GetDatepos()
|
||
{
|
||
if (HttpContext.Current.Session[SessionNameDatepos] == null)
|
||
{
|
||
HttpContext.Current.Session[SessionNameDatepos] = 0;
|
||
}
|
||
return (int)HttpContext.Current.Session[SessionNameDatepos];
|
||
}
|
||
|
||
/// <summary>
|
||
/// 设置时间记录位置，相当于当前队列位置
|
||
/// </summary>
|
||
/// <param name="pos"></param>
|
||
private void SetDatepos(int pos)
|
||
{
|
||
HttpContext.Current.Session[SessionNameDatepos] = pos;
|
||
}
|
||
#endregion
|
||
|
||
/// <summary>
|
||
/// 构造访问检测器，限定指定时间内最多请求次数
|
||
/// </summary>
|
||
/// <param name="name">名称</param>
|
||
/// <param name="seconds">限定时间范围（秒数）</param>
|
||
/// <param name="times">限定次数</param>
|
||
public FrequencyControler(string name, int seconds, int times)
|
||
{
|
||
Name = name;
|
||
Seconds = seconds;
|
||
Times = times;
|
||
if (times > MAX_TIMES) throw new Exception("限定次数设置值超出上限！");
|
||
}
|
||
|
||
/// <summary>
|
||
/// 记录一次访问，在时间点数组的下一个位置（按最大长度循环覆盖存储）
|
||
/// </summary>
|
||
public void Record()
|
||
{
|
||
long[] ds = GetDateList();
|
||
int pos = GetDatepos();
|
||
pos = (pos + 1) % ds.Length;
|
||
ds[pos] = DateTime.Now.Ticks;
|
||
SetDatepos(pos);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 判断是否达到访问限制（并默认记录一次请求）
|
||
/// </summary>
|
||
/// <returns></returns>
|
||
public bool IsTooFrequently()
|
||
{
|
||
return IsTooFrequently(true);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 判断是否达到访问限制（主要外部使用功能）
|
||
/// </summary>
|
||
/// <param name="isRecord">是否包含本次请求，为true时，会先记录一次请求再判断</param>
|
||
/// <returns></returns>
|
||
public bool IsTooFrequently(bool isRecord)
|
||
{
|
||
if (isRecord) Record();
|
||
|
||
long[] ds = GetDateList();
|
||
int pos = GetDatepos();
|
||
|
||
// 取得之前 限定次数 位置的时间点与最后的时间点比较，
|
||
// 如果之前的访问次数还没有达到限定次数则忽略
|
||
int pre_pos = (pos + ds.Length - Times + 1) % ds.Length;
|
||
long pre_ticks = ds[pre_pos];
|
||
long now_ticks = ds[pos];
|
||
// 如果访问的次烤都还没有达到限定次数，pre_ticks 必定为0，所以大于0时才进行比较
|
||
if (pre_ticks > 0)
|
||
{
|
||
TimeSpan span = new TimeSpan(now_ticks - pre_ticks);
|
||
if (span.TotalSeconds <= Seconds)
|
||
{
|
||
return true;
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
}
|
||
}
|