1da2e3ebdSchin /*********************************************************************** 2da2e3ebdSchin * * 3da2e3ebdSchin * This software is part of the ast package * 4*3e14f97fSRoger A. Faulkner * Copyright (c) 1985-2010 AT&T Intellectual Property * 5da2e3ebdSchin * and is licensed under the * 6da2e3ebdSchin * Common Public License, Version 1.0 * 77c2fbfb3SApril Chin * by AT&T Intellectual Property * 8da2e3ebdSchin * * 9da2e3ebdSchin * A copy of the License is available at * 10da2e3ebdSchin * http://www.opensource.org/licenses/cpl1.0.txt * 11da2e3ebdSchin * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12da2e3ebdSchin * * 13da2e3ebdSchin * Information and Software Systems Research * 14da2e3ebdSchin * AT&T Research * 15da2e3ebdSchin * Florham Park NJ * 16da2e3ebdSchin * * 17da2e3ebdSchin * Glenn Fowler <gsf@research.att.com> * 18da2e3ebdSchin * David Korn <dgk@research.att.com> * 19da2e3ebdSchin * Phong Vo <kpv@research.att.com> * 20da2e3ebdSchin * * 21da2e3ebdSchin ***********************************************************************/ 22da2e3ebdSchin #pragma prototyped 23da2e3ebdSchin /* 24da2e3ebdSchin * Glenn Fowler 25da2e3ebdSchin * AT&T Bell Laboratories 26da2e3ebdSchin * 27da2e3ebdSchin * hash table library 28da2e3ebdSchin */ 29da2e3ebdSchin 30da2e3ebdSchin #include "hashlib.h" 31da2e3ebdSchin 32da2e3ebdSchin /* 33da2e3ebdSchin * return a running 32 bit checksum of buffer b of length n 34da2e3ebdSchin * 35da2e3ebdSchin * c is the return value from a previous 36da2e3ebdSchin * memsum() or strsum() call, 0 on the first call 37da2e3ebdSchin * 38da2e3ebdSchin * the result is the same on all implementations 39da2e3ebdSchin */ 40da2e3ebdSchin 41da2e3ebdSchin unsigned long memsum(const void * ap,int n,register unsigned long c)42da2e3ebdSchinmemsum(const void* ap, int n, register unsigned long c) 43da2e3ebdSchin { 44da2e3ebdSchin register const unsigned char* p = (const unsigned char*)ap; 45da2e3ebdSchin register const unsigned char* e = p + n; 46da2e3ebdSchin 47da2e3ebdSchin while (p < e) HASHPART(c, *p++); 48da2e3ebdSchin #if LONG_MAX > 2147483647 49da2e3ebdSchin return(c & 0xffffffff); 50da2e3ebdSchin #else 51da2e3ebdSchin return(c); 52da2e3ebdSchin #endif 53da2e3ebdSchin } 54