C#，数值计算——64位哈希表的计算方法与实现代码

1 文本格式

using System;

namespace Legalsoft.Truffer
{
    public class HashAll
    {
        public HashAll()
        {
        }

        ///

        /// Pseudo-DES hashing of the 64-bit word(lword, rword). Both 32-bit arguments
        /// are returned hashed on all bits.
        ///

        ///
        ///
        public static void psdes(ref uint lword, ref uint rword)
        {
            const int NITER = 2;
            uint[] c1 = { 0xbaa96887, 0x1e17d32c, 0x03bcdc3c, 0x0f33d1b2 };
            uint[] c2 = { 0x4b0f3b58, 0xe874f0c3, 0x6955c5a6, 0x55a7ca46 };

            uint itmph = 0;
            uint itmpl = 0;
            for (uint i = 0; i < NITER; i++)
            {
                uint iswap = rword;
                uint ia = (uint)((iswap) ^ c1[i]);
                itmpl = ia & 0xffff;
                itmph = (uint)(ia >> 16);
                uint ib = itmpl * itmpl + ~(itmph * itmph);
                rword = (uint)(lword ^ (((ia = (uint)((ib >> 16) | ((ib & 0xffff) << 16))) ^ c2[i]) + itmpl * itmph));
                lword = iswap;
            }
        }

        ///

        /// Replace the array arr by a same-sized hash, all of whose bits depend on all
        /// of the bits in arr.Uses psdes for the mutual hash of two 32-bit words.
        ///

        ///
        ///
        public static void hashall(uint[] arr)
        {
            int m = arr.Length;
            int n = m - 1;
            n |= n >> 1;
            n |= n >> 2;
            n |= n >> 4;
            n |= n >> 8;
            n |= n >> 16;
            n++;
            int nb = n;
            int nb2 = n >> 1;
            if (n < 2)
            {
                throw new Exception("size must be > 1");
            }
            while (nb > 1)
            {
                for (int jb = 0; jb < n - nb + 1; jb += nb)
                {
                    for (int j = 0; j < nb2; j++)
                    {
                        if (jb + j + nb2 < m)
                        {
                            psdes(ref arr[jb + j], ref arr[jb + j + nb2]);
                            //uint jbj = arr[jb + j];
                            //uint jbjnb2 = arr[jb + j + nb2];
                            //psdes(ref jbj, ref jbjnb2);
                            //arr[jb + j] = jbj;
                            //arr[jb + j + nb2] = jbjnb2;
                        }
                    }
                }
                nb = nb2;
                nb2 >>= 1;
            }
            nb2 = n >> 1;
            if (m != n)
            {
                for (int j = nb2; j < m; j++)
                {
                    psdes(ref arr[j], ref arr[j - nb2]);
                    //uint jbj = arr[j];
                    //uint jbjnb2 = arr[j - nb2];
                    //psdes(ref jbj, ref jbjnb2);
                    //arr[j] = jbj;
                    //arr[j - nb2] = jbjnb2;
                }
            }
        }
    }
}
 

2 代码格式

using System;

namespace Legalsoft.Truffer
{
    public class HashAll
    {
        public HashAll()
        {
        }

        /// 

        /// Pseudo-DES hashing of the 64-bit word(lword, rword). Both 32-bit arguments
        /// are returned hashed on all bits.
        /// 
        /// 
        /// 
        public static void psdes(ref uint lword, ref uint rword)
        {
            const int NITER = 2;
            uint[] c1 = { 0xbaa96887, 0x1e17d32c, 0x03bcdc3c, 0x0f33d1b2 };
            uint[] c2 = { 0x4b0f3b58, 0xe874f0c3, 0x6955c5a6, 0x55a7ca46 };

            uint itmph = 0;
            uint itmpl = 0;
            for (uint i = 0; i < NITER; i++)
            {
                uint iswap = rword;
                uint ia = (uint)((iswap) ^ c1[i]);
                itmpl = ia & 0xffff;
                itmph = (uint)(ia >> 16);
                uint ib = itmpl * itmpl + ~(itmph * itmph);
                rword = (uint)(lword ^ (((ia = (uint)((ib >> 16) | ((ib & 0xffff) << 16))) ^ c2[i]) + itmpl * itmph));
                lword = iswap;
            }
        }

        /// 

        /// Replace the array arr by a same-sized hash, all of whose bits depend on all
        /// of the bits in arr.Uses psdes for the mutual hash of two 32-bit words.
        /// 
        /// 
        /// 
        public static void hashall(uint[] arr)
        {
            int m = arr.Length;
            int n = m - 1;
            n |= n >> 1;
            n |= n >> 2;
            n |= n >> 4;
            n |= n >> 8;
            n |= n >> 16;
            n++;
            int nb = n;
            int nb2 = n >> 1;
            if (n < 2)
            {
                throw new Exception("size must be > 1");
            }
            while (nb > 1)
            {
                for (int jb = 0; jb < n - nb + 1; jb += nb)
                {
                    for (int j = 0; j < nb2; j++)
                    {
                        if (jb + j + nb2 < m)
                        {
                            psdes(ref arr[jb + j], ref arr[jb + j + nb2]);
                            //uint jbj = arr[jb + j];
                            //uint jbjnb2 = arr[jb + j + nb2];
                            //psdes(ref jbj, ref jbjnb2);
                            //arr[jb + j] = jbj;
                            //arr[jb + j + nb2] = jbjnb2;
                        }
                    }
                }
                nb = nb2;
                nb2 >>= 1;
            }
            nb2 = n >> 1;
            if (m != n)
            {
                for (int j = nb2; j < m; j++)
                {
                    psdes(ref arr[j], ref arr[j - nb2]);
                    //uint jbj = arr[j];
                    //uint jbjnb2 = arr[j - nb2];
                    //psdes(ref jbj, ref jbjnb2);
                    //arr[j] = jbj;
                    //arr[j - nb2] = jbjnb2;
                }
            }
        }
    }
}