65 строки
1.1 KiB
C
65 строки
1.1 KiB
C
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/*
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* Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define DYNAMIC_DEBUG_HASH_BITS 6
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static const char *program;
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static void usage(void)
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{
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printf("Usage: %s <djb2|r5> <modname>\n", program);
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exit(1);
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}
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/* djb2 hashing algorithm by Dan Bernstein. From:
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* http://www.cse.yorku.ca/~oz/hash.html
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*/
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unsigned int djb2_hash(char *str)
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{
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unsigned long hash = 5381;
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int c;
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c = *str;
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while (c) {
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hash = ((hash << 5) + hash) + c;
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c = *++str;
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}
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return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
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}
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unsigned int r5_hash(char *str)
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{
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unsigned long hash = 0;
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int c;
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c = *str;
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while (c) {
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hash = (hash + (c << 4) + (c >> 4)) * 11;
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c = *++str;
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}
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return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
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}
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int main(int argc, char *argv[])
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{
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program = argv[0];
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if (argc != 3)
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usage();
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if (!strcmp(argv[1], "djb2"))
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printf("%d\n", djb2_hash(argv[2]));
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else if (!strcmp(argv[1], "r5"))
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printf("%d\n", r5_hash(argv[2]));
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else
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usage();
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exit(0);
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}
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