1 /* 2 * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com> 3 * 4 */ 5 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <string.h> 9 10 #define DYNAMIC_DEBUG_HASH_BITS 6 11 12 static const char *program; 13 usage(void)14static void usage(void) 15 { 16 printf("Usage: %s <djb2|r5> <modname>\n", program); 17 exit(1); 18 } 19 20 /* djb2 hashing algorithm by Dan Bernstein. From: 21 * http://www.cse.yorku.ca/~oz/hash.html 22 */ 23 djb2_hash(char * str)24unsigned int djb2_hash(char *str) 25 { 26 unsigned long hash = 5381; 27 int c; 28 29 c = *str; 30 while (c) { 31 hash = ((hash << 5) + hash) + c; 32 c = *++str; 33 } 34 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); 35 } 36 r5_hash(char * str)37unsigned int r5_hash(char *str) 38 { 39 unsigned long hash = 0; 40 int c; 41 42 c = *str; 43 while (c) { 44 hash = (hash + (c << 4) + (c >> 4)) * 11; 45 c = *++str; 46 } 47 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); 48 } 49 main(int argc,char * argv[])50int main(int argc, char *argv[]) 51 { 52 program = argv[0]; 53 54 if (argc != 3) 55 usage(); 56 if (!strcmp(argv[1], "djb2")) 57 printf("%d\n", djb2_hash(argv[2])); 58 else if (!strcmp(argv[1], "r5")) 59 printf("%d\n", r5_hash(argv[2])); 60 else 61 usage(); 62 exit(0); 63 } 64 65