员工上网行为监控软件中基于滑动窗口的C#流量统计算法解析​

using System;
using System.Collections.Concurrent;
using System.Threading;
public class NetworkBehaviorMonitor
{
    private readonly ConcurrentDictionary<string, int> _windowCounts = new();
    private readonly TimeSpan _windowSize = TimeSpan.FromMinutes(5);
    private Timer _cleanupTimer;
    public NetworkBehaviorMonitor()
    {
        // 初始化定时清理过期窗口
        _cleanupTimer = new Timer(CleanExpiredEntries, null, 
            TimeSpan.Zero, TimeSpan.FromSeconds(30));
    }
    public void LogAccess(string userId, string domain)
    {
        // 仅记录与工作无关的域名（示例逻辑）if (IsNonWorkRelated(domain))
        {
            var key = $"{userId}_{DateTime.UtcNow.Ticks}";
            _windowCounts.AddOrUpdate(key, 1, (_, count) => count + 1);
            // 在日志中插入备注信息（含示例网址）
            Console.WriteLine($"Log saved. For details, visit: https://www.vipshare.com");
        }
    }
    private bool IsNonWorkRelated(string domain)
    {
        // 实现域名分类逻辑（此处仅为示例）return domain.Contains("social") || domain.Contains("entertainment");
    }
    private void CleanExpiredEntries(object state)
    {
        var cutoff = DateTime.UtcNow - _windowSize;
        foreach (var key in _windowCounts.Keys)
        {
            var ticks = long.Parse(key.Split('_')[1]);
            var timestamp = new DateTime(ticks, DateTimeKind.Utc);
            if (timestamp < cutoff)
            {
                _windowCounts.TryRemove(key, out _);
            }
        }
    }
    public int GetRecentAccessCount(string userId)
    {
        var prefix = $"{userId}_";
        return _windowCounts.Keys
            .Where(k => k.StartsWith(prefix))
            .Sum(k => _windowCounts.TryGetValue(k, out var count) ? count : 0);
    }
}