X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd-alex.git;a=blobdiff_plain;f=src%2Fngircd%2Fhash.c;h=c75b57d596a4d9a4095a89f85153fdaeabb84749;hp=a2801b06fb543b3215022370d98619a2bb4b0fdf;hb=b5faf3055b61afaef73ac49a448cac1a5b063127;hpb=0df6a7610307e8044b1b72298198a8eb83977565 diff --git a/src/ngircd/hash.c b/src/ngircd/hash.c index a2801b06..c75b57d5 100644 --- a/src/ngircd/hash.c +++ b/src/ngircd/hash.c @@ -1,112 +1,118 @@ /* * ngIRCd -- The Next Generation IRC Daemon - * Copyright (c)2001,2002 by Alexander Barton (alex@barton.de) + * Copyright (c)2001-2010 Alexander Barton (alex@barton.de) * - * Dieses Programm ist freie Software. Sie koennen es unter den Bedingungen - * der GNU General Public License (GPL), wie von der Free Software Foundation - * herausgegeben, weitergeben und/oder modifizieren, entweder unter Version 2 - * der Lizenz oder (wenn Sie es wuenschen) jeder spaeteren Version. - * Naehere Informationen entnehmen Sie bitter der Datei COPYING. Eine Liste - * der an ngIRCd beteiligten Autoren finden Sie in der Datei AUTHORS. - * - * $Id: hash.c,v 1.3 2002/03/22 00:21:51 alex Exp $ - * - * hash.c: Hash-Werte berechnen + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * Please read the file COPYING, README and AUTHORS for more information. */ - #include "portab.h" +/** + * @file + * Hash calculation + */ + #include "imp.h" #include #include #include "defines.h" -#include "log.h" #include "tool.h" #include "exp.h" #include "hash.h" +static UINT32 jenkins_hash PARAMS((UINT8 *k, UINT32 length, UINT32 initval)); -LOCAL UINT32 jenkins_hash( register UINT8 *k, register UINT32 length, register UINT32 initval); - - -GLOBAL UINT32 Hash( CHAR *String ) +/** + * Calculate hash value for a given string. + * + * @param String Input string + * @return 32 bit hash value + */ +GLOBAL UINT32 +Hash( const char *String ) { - /* Hash-Wert ueber String berechnen */ - - CHAR buffer[LINE_LEN]; + char buffer[LINE_LEN]; - strncpy( buffer, String, LINE_LEN - 1 ); - buffer[LINE_LEN - 1] = '\0'; - - return jenkins_hash( ngt_LowerStr( buffer ), strlen( buffer ), 42 ); + strlcpy(buffer, String, sizeof(buffer)); + return jenkins_hash((UINT8 *)ngt_LowerStr(buffer), + (UINT32)strlen(buffer), 42); } /* Hash */ - /* - * Die hier verwendete Hash-Funktion stammt aus lookup2.c von Bob Jenkins - * (URL: ). Aus dem Header: + * This hash function originates from lookup3.c of Bob Jenkins + * (URL: ): * -------------------------------------------------------------------- - * lookup2.c, by Bob Jenkins, December 1996, Public Domain. - * hash(), hash2(), hash3, and mix() are externally useful functions. - * Routines to test the hash are included if SELF_TEST is defined. - * You can use this free for any purpose. It has no warranty. + * lookup3.c, by Bob Jenkins, May 2006, Public Domain. + * These are functions for producing 32-bit hashes for hash table lookup. + * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() + * are externally useful functions. Routines to test the hash are included + * if SELF_TEST is defined. You can use this free for any purpose. It's in + * the public domain. It has no warranty. * -------------------------------------------------------------------- - * nicht alle seiner Funktionen werden hier genutzt. + * Not all of his functions are used here. */ - #define hashsize(n) ((UINT32)1<<(n)) #define hashmask(n) (hashsize(n)-1) +#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) #define mix(a,b,c) \ { \ - a -= b; a -= c; a ^= (c>>13); \ - b -= c; b -= a; b ^= (a<<8); \ - c -= a; c -= b; c ^= (b>>13); \ - a -= b; a -= c; a ^= (c>>12); \ - b -= c; b -= a; b ^= (a<<16); \ - c -= a; c -= b; c ^= (b>>5); \ - a -= b; a -= c; a ^= (c>>3); \ - b -= c; b -= a; b ^= (a<<10); \ - c -= a; c -= b; c ^= (b>>15); \ + a -= c; a ^= rot(c, 4); c += b; \ + b -= a; b ^= rot(a, 6); a += c; \ + c -= b; c ^= rot(b, 8); b += a; \ + a -= c; a ^= rot(c,16); c += b; \ + b -= a; b ^= rot(a,19); a += c; \ + c -= b; c ^= rot(b, 4); b += a; \ } /* mix */ - -LOCAL UINT32 jenkins_hash( register UINT8 *k, register UINT32 length, register UINT32 initval) +#define final(a,b,c) \ +{ \ + c ^= b; c -= rot(b,14); \ + a ^= c; a -= rot(c,11); \ + b ^= a; b -= rot(a,25); \ + c ^= b; c -= rot(b,16); \ + a ^= c; a -= rot(c,4); \ + b ^= a; b -= rot(a,14); \ + c ^= b; c -= rot(b,24); \ +} + +static UINT32 +jenkins_hash(UINT8 *k, UINT32 length, UINT32 initval) { /* k: the key * length: length of the key * initval: the previous hash, or an arbitrary value */ - - register UINT32 a,b,c,len; + UINT32 a,b,c; /* Set up the internal state */ - len = length; - a = b = 0x9e3779b9; /* the golden ratio; an arbitrary value */ - c = initval; /* the previous hash value */ + a = b = c = 0xdeadbeef + length + initval; /* handle most of the key */ - while (len >= 12) - { + while (length > 12) { a += (k[0] +((UINT32)k[1]<<8) +((UINT32)k[2]<<16) +((UINT32)k[3]<<24)); b += (k[4] +((UINT32)k[5]<<8) +((UINT32)k[6]<<16) +((UINT32)k[7]<<24)); c += (k[8] +((UINT32)k[9]<<8) +((UINT32)k[10]<<16)+((UINT32)k[11]<<24)); mix(a,b,c); - k += 12; len -= 12; + length -= 12; + k += 12; } - /* handle the last 11 bytes */ - c += length; - switch(len) /* all the case statements fall through */ + /*-------------------------------- last block: affect all 32 bits of (c) */ + switch(length) /* all the case statements fall through */ + { - case 11: c+=((UINT32)k[10]<<24); - case 10: c+=((UINT32)k[9]<<16); - case 9 : c+=((UINT32)k[8]<<8); - /* the first byte of c is reserved for the length */ + case 12: c+=((UINT32)k[11])<<24; + case 11: c+=((UINT32)k[10]<<16); + case 10: c+=((UINT32)k[9]<<8); + case 9 : c+=k[8]; case 8 : b+=((UINT32)k[7]<<24); case 7 : b+=((UINT32)k[6]<<16); case 6 : b+=((UINT32)k[5]<<8); @@ -115,13 +121,11 @@ LOCAL UINT32 jenkins_hash( register UINT8 *k, register UINT32 length, register U case 3 : a+=((UINT32)k[2]<<16); case 2 : a+=((UINT32)k[1]<<8); case 1 : a+=k[0]; - /* case 0: nothing left to add */ + break; + case 0 : return c; } - mix(a,b,c); - - /* report the result */ + final(a,b,c); return c; } /* jenkins_hash */ - /* -eof- */