| 1 | |
| 2 | * Copyright (C) 2008 Red Hat, Inc., Jason Baron <[email protected]>
|
| 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 |
|
| 14 | static void usage(void)
|
| 15 | {
|
| 16 | printf("Usage: %s <djb2|r5> <modname>\n", program);
|
| 17 | exit(1);
|
| 18 | }
|
| 19 |
|
| 20 | |
| 21 | * http://www.cse.yorku.ca/~oz/hash.html
|
| 22 |
|
| 23 |
|
| 24 | unsigned 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 |
|
| 37 | unsigned 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 |
|
| 50 | int 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 |
|