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Appendix: Java Code for a Hash Class



//
//                          A Java Hash Class
//      Including Constructors and Methods for Dealing with Hash Values
//
//            Copyright (c)1996 Robert Uzgalis, All Rights Reserved.
//

import java.io.*;
import java.lang.*;

public class Hash
{   private long hash_code;

    private static long initial_hash = 0xe12398c6d9ae3b8aL;  // initial values
    private static long hash_true    = 0x851dcaa2656c6af4L;  // are arbitrary
    private static long hash_false   = 0x1af84a6b589285f7L;  // 64-bit rands
    private static long mix_master[/* 0:255 */]  = {
    /* 000 */ 0x4476081a7043a46fL, 0x45768b8a6e7eac19L, 0xebd556c1cf055952L,
    /*     */ 0x72ed2da1bf010101L, 0x3ff2030b128e8a64L,
    /* 005 */ 0xcbc330238adcfef2L, 0x737807fe42e20c6cL, 0x74dabaedb1095c58L,
    /*     */ 0x968f065c65361d67L, 0xd3f4018ac7a4b199L,
    /* 010 */ 0x954b389b52f24df2L, 0x2f97a9d8d0549327L, 0xb9bea2b49a3b180fL,
    /*     */ 0xaf2f42536b21f2ebL, 0x85d991663cff1325L,
    /* 015 */ 0xb9e1260207b575b9L, 0xf3ea88398a23b7e2L, 0xfaf8c83ffbd9091dL,
    /*     */ 0x4274fe90834dbdf9L, 0x3f20b157b68d6313L,
    /* 020 */ 0x68b48972b6d06b93L, 0x694837b6eba548afL, 0xeecb51d1acc917c9L,
    /*     */ 0xf1c633f02dffbcfaL, 0xa6549ec9d301f3b5L,
    /* 025 */ 0x451dc944f1663592L, 0x446d6acef6ce9e4fL, 0x1c8a5b3013206f02L,
    /*     */ 0x5908ca36f2dc50f7L, 0x4fd55d3f3e880a87L,
    /* 030 */ 0xa03a8dbeabbf065dL, 0x3ccbbe078fabcb6dL, 0x1da53a259116f2d0L,
    /*     */ 0xfb27a96fcb9af152L, 0x50aba242e85aec09L,
    /* 035 */ 0x24d4e414fc4fc987L, 0x83971844a9ce535eL, 0xc26a3fdeb849398eL,
    /*     */ 0xc2380d044d2e70d8L, 0xab418aa8ae19b18fL,
    /* 040 */ 0xd95b6b9247d5ebeaL, 0x8b3b2171fdc60511L, 0xe15cd0ae3fcc44afL,
    /*     */ 0x5a4e27f914a68f17L, 0x377bd28ca09aafdcL,
    /* 045 */ 0xbbeb9828594a3294L, 0x7c8df263ae1de1b9L, 0xba0a48a5fd1c1dd0L,
    /*     */ 0x57cc1b8818b98ee6L, 0x8c570975d357dabcL,
    /* 050 */ 0x76bdcd6f2e8826aaL, 0x529b15b6ec4055f1L, 0x9147c7a54c34f8a9L,
    /*     */ 0x2f96a7728170e402L, 0xe46602f455eca72eL,
    /* 055 */ 0x22834c4dd1bde03fL, 0x2644cf5a25e368ffL, 0x907c6de90b120f4aL,
    /*     */ 0xadfe8ba99028f728L, 0xa85199ae14df0433L,
    /* 060 */ 0x2d749b946dd3601eL, 0x76e35457aa052772L, 0x90410bf6e427f736L,
    /*     */ 0x536ad04d13e35041L, 0x8cc0d76769b76914L,
    /* 065 */ 0xae0249f6e3b3c01cL, 0x1bdfd075307d6fafL, 0xd8e04f70c221deccL,
    /*     */ 0x4ab23622a4281a5dL, 0x37a5613da2fcaba7L,
    /* 070 */ 0x19a56203666d4a9fL, 0x158ffab502c4be93L, 0x0bee714e332ecb2fL,
    /*     */ 0x69b71a59f6f74ab0L, 0x0fc7fc622f1dfe8fL,
    /* 075 */ 0x513966de7152a6f9L, 0xc16fae9cc2ea9be7L, 0xb66f0ac586c1899eL,
    /*     */ 0x11e124aee3bdefd7L, 0x86cf5a577512901bL,
    /* 080 */ 0x33f33ba6994a1fbdL, 0xde6c4d1d3d47ff0dL, 0x6a99220dc6f78e66L,
    /*     */ 0x2dc06ca93e2d25d2L, 0x96413b520134d573L,
    /* 085 */ 0xb4715ce8e1023afaL, 0xe6a75900c8c66c0aL, 0x6448f13ad54c12edL,
    /*     */ 0xb9057c28cf6689f0L, 0xf4023daf67f7677aL,
    /* 090 */ 0x877c2650767b9867L, 0xb7ea587dcd5b2341L, 0xc048cf111733f9bcL,
    /*     */ 0x112012c15bc867bfL, 0xc95f52b1d9418811L,
    /* 095 */ 0xa47e624ee7499083L, 0x26928606df9b12e8L, 0x5d020462ec3e0928L,
    /*     */ 0x8bbde651f6d08914L, 0xd5db83db758e524aL,
    /* 100 */ 0x3105e355c000f455L, 0xdd7fe1b81a786c79L, 0x1f3a818c8e012db1L,
    /*     */ 0xd902de819d7b42faL, 0x4200e63325cda5f0L,
    /* 105 */ 0x0e919cdc5fba9220L, 0x5360dd54605a11e1L, 0xa3182d0e6cb23e6cL,
    /*     */ 0x13ee462c1b483b87L, 0x1b1b6087b997ee22L,
    /* 110 */ 0x81c36d0b877f7362L, 0xc24879932c1768d4L, 0x1faa756e1673f9adL,
    /*     */ 0x61651b24d11fe93dL, 0x30fe3d9304e1cde4L,
    /* 115 */ 0x7be867c750747250L, 0x973e52c7005b5db6L, 0x75d6b699bbaf4817L,
    /*     */ 0x25d2a9e97379e196L, 0xe65fb599aca98701L,
    /* 120 */ 0x6ac27960d24bde84L, 0xdfacc04c9fabbcb6L, 0xa46cd07f4a97882bL,
    /*     */ 0x652031d8e59a1fd8L, 0x1185bd967ec7ce10L,
    /* 125 */ 0xfc9bd84c6780f244L, 0x0a0c59872f61b3ffL, 0x63885727a1c71c95L,
    /*     */ 0x5e88b4390b2d765cL, 0xf0005ccaf988514dL,
    /* 130 */ 0x474e44280a98e840L, 0x32de151c1411bc42L, 0x2c4b86d5aa4482c2L,
    /*     */ 0xccd93deb2d9d47daL, 0x3743236ff128a622L,
    /* 135 */ 0x42ed2f2635ba5647L, 0x99c74afd18962dbdL, 0x2d663bb870f6d242L,
    /*     */ 0x7912033bc7635d81L, 0xb442862f43753680L,
    /* 140 */ 0x94b1a5400aeaab4cL, 0x5ce285fe810f2220L, 0xe8a7dbe565d9c0b1L,
    /*     */ 0x219131af78356c94L, 0x7b3a80d130f27e2fL,
    /* 145 */ 0xbaa5d2859d16b440L, 0x821cfb6935771070L, 0xf68cfb6ee9bc2336L,
    /*     */ 0x18244132e935d2fdL, 0x2ed0bda1f4720cffL,
    /* 150 */ 0x4ed48cdf6975173cL, 0xfd37a7a2520e2405L, 0x82c102b2a9e73ce2L,
    /*     */ 0xadac6517062623a7L, 0x5a1294d318e26104L,
    /* 155 */ 0xea84fe65c0e4f061L, 0x4f96f8a9464cfee9L, 0x9831dff8ccdc534aL,
    /*     */ 0x4ca927cd0f192a14L, 0x030900b294b71649L,
    /* 160 */ 0x644b263b9aeb0675L, 0xa601d4e34647e040L, 0x34d897eb397f1004L,
    /*     */ 0xa6101c37f4ec8dfcL, 0xc29d2a8bbfd0006bL,
    /* 165 */ 0xc6b07df8c5b4ed0fL, 0xce1b7d92ba6bccbeL, 0xfa2f99442e03fe1bL,
    /*     */ 0xd8863e4c16f0b363L, 0x033b2cccc3392942L,
    /* 170 */ 0x757dc33522d6cf9cL, 0xf07b1ff6ce55fec5L, 0x1569e75f09b40463L,
    /*     */ 0xfa33fa08f14a310bL, 0x6eb79aa27bbcf76bL,
    /* 175 */ 0x157061207c249602L, 0x25e5a71fc4e99555L, 0x5df1fe93de625355L,
    /*     */ 0x235b56090c1aa55dL, 0xe51068613eaced91L,
    /* 180 */ 0x45bd47b893b9ff1eL, 0x6595e1798d381f2dL, 0xc9b5848cbcdb5ba8L,
    /*     */ 0x65985146ff7792bcL, 0x4ab4a17bf05a19a0L,
    /* 185 */ 0xfd94f4ca560ffb0cL, 0xcf9bad581a68fa68L, 0x92b4f0b502b1ce1aL,
    /*     */ 0xbcbec0769a610474L, 0x8dbd31ded1a0fecbL,
    /* 190 */ 0xdd1f5ed9f90e8533L, 0x61c1e6a523f84d95L, 0xf24475f383c110c4L,
    /*     */ 0xdb2dffa66f90588dL, 0xac06d88e9ee04455L,
    /* 195 */ 0xa215fc47c40504baL, 0x86d7caebfee93369L, 0x9eaec31985804099L,
    /*     */ 0x0fba2214abe5d01bL, 0x5a32975a4b3865d6L,
    /* 200 */ 0x8cceebc98a5c108fL, 0x7e12c4589654f2dcL, 0xa49ad49fb0d19772L,
    /*     */ 0x3d142dd9c406152bL, 0x9f13589e7be2b8a5L,
    /* 205 */ 0x5e8dbac1892967adL, 0xcc23b93a6308e597L, 0x1ef35f5fe874e16aL,
    /*     */ 0x63ae9cc08d2e274fL, 0x5bbabee56007fc05L,
    /* 210 */ 0xabfd72994230fc39L, 0x9d71a13a99144de1L, 0xd9daf5aa8dcc89b3L,
    /*     */ 0xe145ec0514161bfdL, 0x143befc2498cd270L,
    /* 215 */ 0xa8e192557dbbd9f8L, 0xcbeda2445628d7d0L, 0x997f0a93205d9ea4L,
    /*     */ 0x01014a97f214ebfaL, 0x70c026ffd1ebedafL,
    /* 220 */ 0xf8737b1b3237002fL, 0x8afcbef3147e6e5eL, 0x0e1bb0684483ebd3L,
    /*     */ 0x4cbad70ae9b05aa6L, 0xd4a31f523517c363L,
    /* 225 */ 0xdb0f057ae8e9e8a2L, 0x400894a919d89df6L, 0x6a626a9b62defab3L,
    /*     */ 0xf907fd7e14f4e201L, 0xe10e4a5657c48f3fL,
    /* 230 */ 0xb17f9f54b8e6e5dcL, 0x6b9e69045fa6d27aL, 0x8b74b6a41dc3078eL,
    /*     */ 0x027954d45ca367f9L, 0xd07207b8fdcbb7ccL,
    /* 235 */ 0xf397c47d2f36414bL, 0x05e4e8b11d3a034fL, 0x36adb3f7122d654fL,
    /*     */ 0x607d9540eb336078L, 0xb639118e3a8b9600L,
    /* 240 */ 0xd0a406770b5f1484L, 0x3cbee8213ccfb7c6L, 0x467967bb2ff89cf1L,
    /*     */ 0xb115fe29609919a6L, 0xba740e6ffa83287eL,
    /* 245 */ 0xb4e51be9b694b7cdL, 0xc9a081c677df5aeaL, 0x2e1fbcd8944508ccL,
    /*     */ 0xf626e7895581fbb8L, 0x3ce6e9b5728a05cbL,
    /* 250 */ 0x46e87f2664a31712L, 0x8c1dc526c2f6acfaL, 0x7b4826726e560b10L,
    /*     */ 0x2966e0099d8d7ce1L, 0xbb0dd5240d2b2adeL, 0x0d527cc60bbaa936L
              };


    // Utility Methods for Hash Values
    //

    // Move the bits in an integer long into a StringBuffer without
    // conversion, then hash the string buffer, returning a long.

    private static long lhv (long arg)   // Hash a long
    {   StringBuffer tmp = new StringBuffer(4);
        long aval = arg;

        tmp.setLength(4);
        for ( int i=0; i<4; ++i, aval >>>= 16 )
           tmp.setCharAt( i, (char) aval);

        return buzhash( tmp );
        }



    // This is buzhash the hash function on which most other Hash methods
    // and constructors are built.

    private static long buzhash (StringBuffer arg) /* Hash StringBuffer   */
    {   long h = initial_hash;
        for ( int i=0; i<arg.length(); ++i )
           h = (h<<1) ^ (h>>>63) ^
               mix_master[ ( arg.charAt(i) ^ (arg.charAt(i)>>>8) ) & 0xff ];
        return h;
        }

    //  Constructors for Hash values;
    //  invoked as: new Hash( some-key-to-be-hashed )
    //  they operate on the key and return a Hash value.

    public Hash()               // The Hash of nothing
    {   this.hash_code = initial_hash; }

    public Hash ( Hash hc )     // The next extension of a Hash value
    {   this.hash_code = lhv( hc.hash_code ); }

    public Hash (boolean arg)   // Make Hash from boolean
    {   this.hash_code = ( arg ? hash_true : hash_false ) ; }

    public Hash (byte arg)      // Make Hash from byte
    {   this.hash_code = mix_master[ (((int)(arg))+183) & 0xff ]; }

    public Hash (short arg)     // Make Hash from short
    {   this.hash_code = lhv( (long) arg ); }

    public Hash (char arg)      // Make Hash from char
    {   this.hash_code = lhv( (long) arg ); }

    public Hash (int arg)       // Make Hash from int
    {   this.hash_code = lhv( (long) arg ); }

    public Hash (long arg)      // Make Hash from long
    {   this.hash_code = lhv( arg ); }

    //   These are commented out because they require a C routine
    //   to give back the floating point bits back unconverted
    //   as a long integer.
    //
    // public Hash (float arg)      // Make Hash from float
    // {   this.hash_code = lhv( bytes8( (double) arg ) ); }
    //
    // public Hash (double arg)     // Make Hash from double
    // {   this.hash_code = lhv( bytes8( (double) arg ) ); }

    public Hash (String arg)        // Make Hash from String
    {   this.hash_code = buzhash( new StringBuffer(arg) ); }

    public Hash (StringBuffer arg)  // Make Hash from StringBuffer
    {   this.hash_code = buzhash( arg ); }

    // These are all the constructors supported here, one could think
    // of others, there should be one for every type for which an
    // an equal comparison works.






    // Hash Abstract Type Methods for manipulating Hash Values

    // Methods to Compare Hash Values and Return Boolean.

    public boolean equal ( Hash b )  // Test Equivalence of two Hashes
    {   return ( this.hash_code == b.hash_code ); }

    public boolean not_equal ( Hash b )  // Test Equivalence of two Hashes
    {   return ( this.hash_code != b.hash_code ); }

    public boolean more ( Hash b )  // Test Hash Value a bigger than b
    {   if ( (this.hash_code>>>1) > (b.hash_code>>>1) )
             return true;
        else if ( (this.hash_code>>>1) < (b.hash_code>>>1) )
             return false;
        else return (this.hash_code&0x1) > (b.hash_code&0x1);
        }

    public boolean less ( Hash b )  // Test Hash Value a less than b
    {   return b.more(this); }

    // Methods for Combining Two Hash Values.

    public Hash wag ( Hash b )  // Weak Agglomeration of two Hashes
    {   Hash result = new Hash();
        result.hash_code = this.hash_code ^ b.hash_code;
        return result;
        }

    public Hash sag ( Hash b )  // Strong Agglomeration of two Hashes
    {   StringBuffer tmp = new StringBuffer(8);
        Hash result = new Hash();
        long aval   = this.hash_code;
        long bval   = b.hash_code;

        tmp.setLength(8);
        for( int i=0; i<4; i+=2 )
        {   tmp.setCharAt( i,   (char) aval );
            aval >>>= 16;
            tmp.setCharAt( i+1, (char) bval );
            bval >>>= 16;
            }

        result.hash_code = buzhash( tmp );
        return result;
        }

    // Methods which Convert Hash Values to Integers.

    private static long NOSIGN = 0x7fffffffffffffffL;

    public byte  bag ( byte b )   // Convert Hash to byte
    {   return (byte) ((this.hash_code & NOSIGN ) % (b<0? -b : b )); }

    public short bag ( short b )  // Convert Hash to short
    {   return (short)((this.hash_code & NOSIGN ) % (b<0? -b : b )); }

    public char  bag ( char b )   // Convert Hash to char
    {   return (char) ((this.hash_code & NOSIGN ) % b); }

    public int   bag ( int b )    // Convert Hash to int
    {   return (int)  ((this.hash_code & NOSIGN ) % (b<0? -b : b )); }

    public long  bag ( long b )   // Convert Hash to long
    {   return         (this.hash_code & NOSIGN ) % (b<0? -b : b ); }

}







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Copyright © 1996 Robert Uzgalis, All Rights Reserved.
Contact: Robert Uzgalis <buz@zis.com>
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