diff options
author | David Vrabel <david.vrabel@csr.com> | 2008-10-20 16:07:19 +0100 |
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committer | David Vrabel <david.vrabel@csr.com> | 2008-10-20 16:07:19 +0100 |
commit | 61e0e79ee3c609eb34edf2fe023708cba6a79b1f (patch) | |
tree | 663deacffd4071120dc9badb70428fe5f124c7b9 /scripts/basic/hash.c | |
parent | c15895ef30c2c03e99802951787183039a349d32 (diff) | |
parent | 0cfd81031a26717fe14380d18275f8e217571615 (diff) |
Merge branch 'master' into for-upstream
Conflicts:
Documentation/ABI/testing/sysfs-bus-usb
drivers/Makefile
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 00000000000..3299ad7fc8c --- /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); +} + |