xfs: implement ->dirty_inode to fix timestamp handling
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / scripts / basic / hash.c
blob3299ad7fc8c0faae87debf0860d155dbae5d7b83
1 /*
2 * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
4 */
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
10 #define DYNAMIC_DEBUG_HASH_BITS 6
12 static const char *program;
14 static void usage(void)
16 printf("Usage: %s <djb2|r5> <modname>\n", program);
17 exit(1);
20 /* djb2 hashing algorithm by Dan Bernstein. From:
21 * http://www.cse.yorku.ca/~oz/hash.html
24 unsigned int djb2_hash(char *str)
26 unsigned long hash = 5381;
27 int c;
29 c = *str;
30 while (c) {
31 hash = ((hash << 5) + hash) + c;
32 c = *++str;
34 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
37 unsigned int r5_hash(char *str)
39 unsigned long hash = 0;
40 int c;
42 c = *str;
43 while (c) {
44 hash = (hash + (c << 4) + (c >> 4)) * 11;
45 c = *++str;
47 return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
50 int main(int argc, char *argv[])
52 program = argv[0];
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);