c# - byte[] 数组模式搜索

Question

任何人都知道在 byte[] 数组中搜索/匹配字节模式然后返回位置的好而有效的方法。

例如

byte[] pattern = new byte[] {12,3,5,76,8,0,6,125};

byte[] toBeSearched = new byte[] {23,36,43,76,125,56,34,234,12,3,5,76,8,0,6,125,234,56,211,122,22,4,7,89,76,64,12,3,5,76,8,0,6,125}

Answer 1

我可以建议一些不涉及创建字符串、复制数组或不安全代码的东西吗:

using System;
using System.Collections.Generic;

static class ByteArrayRocks
{    
    static readonly int[] Empty = new int[0];

    public static int[] Locate (this byte[] self, byte[] candidate)
    {
        if (IsEmptyLocate(self, candidate))
            return Empty;

        var list = new List<int>();

        for (int i = 0; i < self.Length; i++)
        {
            if (!IsMatch(self, i, candidate))
                continue;

            list.Add(i);
        }

        return list.Count == 0 ? Empty : list.ToArray();
    }

    static bool IsMatch (byte[] array, int position, byte[] candidate)
    {
        if (candidate.Length > (array.Length - position))
            return false;

        for (int i = 0; i < candidate.Length; i++)
            if (array[position + i] != candidate[i])
                return false;

        return true;
    }

    static bool IsEmptyLocate (byte[] array, byte[] candidate)
    {
        return array == null
            || candidate == null
            || array.Length == 0
            || candidate.Length == 0
            || candidate.Length > array.Length;
    }

    static void Main()
    {
        var data = new byte[] { 23, 36, 43, 76, 125, 56, 34, 234, 12, 3, 5, 76, 8, 0, 6, 125, 234, 56, 211, 122, 22, 4, 7, 89, 76, 64, 12, 3, 5, 76, 8, 0, 6, 125 };
        var pattern = new byte[] { 12, 3, 5, 76, 8, 0, 6, 125 };

        foreach (var position in data.Locate(pattern))
            Console.WriteLine(position);
    }
}

编辑(通过 IAbstract) - 移动 post 的内容在这里，因为它不是答案

出于好奇，我创建了一个带有不同答案的小基准。

这是一百万次迭代的结果:

solution [Locate]:            00:00:00.7714027
solution [FindAll]:           00:00:03.5404399
solution [SearchBytePattern]: 00:00:01.1105190
solution [MatchBytePattern]:  00:00:03.0658212