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#include <u.h>
#include <libc.h>
enum {
MULT = 31,
NHASH = 37,
};
uint
hash(char *s)
{
uint h;
h = 0;
while(*s != 0)
h = MULT * h + (uchar)*s++;
return h % NHASH;
}
uint
djb2(char *s)
{
uint h;
h = 5381;
while(*s != 0)
h = ((h << 5) + h) + (uchar)*s++;
return h % NHASH;
}
uint
djb2a(char *s)
{
uint h;
h = 5381;
while(*s != 0)
h = ((h << 5) + h) ^ (uchar)*s++;
return h % NHASH;
}
uint
fnv1(char *s)
{
uint h;
h = 0x811c9dc5;
while(*s != 0)
h = (h*0x1000193) ^ (uchar)*s++;
return h % NHASH;
}
uint
fnv1a(char *s)
{
uint h;
h = 0x811c9dc5;
while(*s != 0)
h = (h^(uchar)*s++) * 0x1000193;
return h % NHASH;
}
void
usage(void)
{
fprint(2, "usage: %s word\n", argv0);
exits("usage");
}
void
main(int argc, char *argv[])
{
ARGBEGIN{
default: usage();
}ARGEND;
if(argc != 1)
usage();
print("tpop:\t%ud\n", hash(*argv));
print("djb2:\t%ud\n", djb2(*argv));
print("djb2a:\t%ud\n", djb2a(*argv));
print("fnv1:\t%ud\n", fnv1(*argv));
print("fnv1a:\t%ud\n", fnv1a(*argv));
exits(0);
}
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