【Hash概念与Java语言】 (代码)
2011-09-06 00:33
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// // A Java Hash Class // Including Constructors and Methods for Dealing with Hash Values // // Copyright (c)1996 Robert Uzgalis, All Rights Reserved. // Modified hash code (c) 2011 Robert Uzgalis // This versions is slightly less efficient but will work // for long keys and is less easy to break. -- BUZ // 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; long j = 37; for ( int i=0; i<arg.length(); ++i ) h = (h<<1) ^ (h>>>63) ^ mix_master[ ( arg.charAt(i) ^ (arg.charAt(i)>>>8) + j ) & 0xff ]; j = h>>>7 & 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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