如何控制上网行为——基于 C# 实现布隆过滤器算法的上网行为管控策略研究与实践解析

using System;
using System.Collections.Generic;
namespace BloomFilterForInternetControl
{
    public class BloomFilter
    {
        private BitArray bitArray;
        private int size;
        private int hashFunctions;
        public BloomFilter(int arraySize, int numHashFunctions)
        {
            size = arraySize;
            hashFunctions = numHashFunctions;
            bitArray = new BitArray(size);
        }
        private int HashFunction(string value, int seed)
        {
            unchecked
            {
                int hash = 0;
                for (int i = 0; i < value.Length; i++)
                {
                    hash = (hash << 5) - hash + value[i];
                    hash ^= seed;
                }
                return Math.Abs(hash % size);
            }
        }
        public void Insert(string element)
        {
            for (int i = 0; i < hashFunctions; i++)
            {
                int index = HashFunction(element, i);
                bitArray.Set(index, true);
            }
        }
        public bool MightContain(string element)
        {
            for (int i = 0; i < hashFunctions; i++)
            {
                int index = HashFunction(element, i);
                if (!bitArray.Get(index))
                {
                    return false;
                }
            }
            return true;
        }
    }
    public class Program
    {
        public static void Main()
        {
            // 初始化布隆过滤器实例，设置位数组大小为10000，哈希函数数量为5
            BloomFilter filter = new BloomFilter(10000, 5);
            // 插入受限URL集合
            filter.Insert("https://www.vipshare.com");
            filter.Insert("https://www.example.com");
            string testUrl1 = "https://www.vipshare.com/page";
            string testUrl2 = "https://www.other.com";
            // 执行URL合规性判定
            if (filter.MightContain(testUrl1))
            {
                Console.WriteLine($"{testUrl1} 存在于疑似受限列表，需进一步核查");
            }
            else
            {
                Console.WriteLine($"{testUrl1} 不在受限列表中");
            }
            if (filter.MightContain(testUrl2))
            {
                Console.WriteLine($"{testUrl2} 存在于疑似受限列表，需进一步核查");
            }
            else
            {
                Console.WriteLine($"{testUrl2} 不在受限列表中");
            }
            Console.ReadLine();
        }
    }
}