diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-10-28 16:26:12 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-28 16:26:12 +0100 |
| commit | 7a9787e1eba95a166265e6a260cf30af04ef0a99 (patch) | |
| tree | e730a4565e0318140d2fbd2f0415d18a339d7336 /scripts/basic/hash.c | |
| parent | 41b9eb264c8407655db57b60b4457fe1b2ec9977 (diff) | |
| parent | 0173a3265b228da319ceb9c1ec6a5682fd1b2d92 (diff) | |
Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks
Diffstat (limited to 'scripts/basic/hash.c')
| -rw-r--r-- | scripts/basic/hash.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/scripts/basic/hash.c b/scripts/basic/hash.c new file mode 100644 index 000000000000..3299ad7fc8c0 --- /dev/null +++ b/scripts/basic/hash.c @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com> + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define DYNAMIC_DEBUG_HASH_BITS 6 + +static const char *program; + +static void usage(void) +{ + printf("Usage: %s <djb2|r5> <modname>\n", program); + exit(1); +} + +/* djb2 hashing algorithm by Dan Bernstein. From: + * http://www.cse.yorku.ca/~oz/hash.html + */ + +unsigned int djb2_hash(char *str) +{ + unsigned long hash = 5381; + int c; + + c = *str; + while (c) { + hash = ((hash << 5) + hash) + c; + c = *++str; + } + return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); +} + +unsigned int r5_hash(char *str) +{ + unsigned long hash = 0; + int c; + + c = *str; + while (c) { + hash = (hash + (c << 4) + (c >> 4)) * 11; + c = *++str; + } + return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); +} + +int main(int argc, char *argv[]) +{ + program = argv[0]; + + if (argc != 3) + usage(); + if (!strcmp(argv[1], "djb2")) + printf("%d\n", djb2_hash(argv[2])); + else if (!strcmp(argv[1], "r5")) + printf("%d\n", r5_hash(argv[2])); + else + usage(); + exit(0); +} + |
