16 static void zipf_update(struct zipf_state *zs)  in zipf_update()  argument
26 	to_gen = min(zs->nranges, (uint64_t) ZIPF_MAX_GEN);  in zipf_update()
29 		zs->zetan += pow(1.0 / (double) (i + 1), zs->theta);  in zipf_update()
32 static void shared_rand_init(struct zipf_state *zs, unsigned long nranges,  in shared_rand_init()  argument
35 	memset(zs, 0, sizeof(*zs));  in shared_rand_init()
36 	zs->nranges = nranges;  in shared_rand_init()
38 	init_rand_seed(&zs->rand, seed);  in shared_rand_init()
39 	zs->rand_off = __rand(&zs->rand);  in shared_rand_init()
42 void zipf_init(struct zipf_state *zs, unsigned long nranges, double theta,  in zipf_init()  argument
45 	shared_rand_init(zs, nranges, seed);  in zipf_init()
47 	zs->theta = theta;  in zipf_init()
48 	zs->zeta2 = pow(1.0, zs->theta) + pow(0.5, zs->theta);  in zipf_init()
50 	zipf_update(zs);  in zipf_init()
53 unsigned long long zipf_next(struct zipf_state *zs)  in zipf_next()  argument
56 	unsigned long long n = zs->nranges;  in zipf_next()
59 	alpha = 1.0 / (1.0 - zs->theta);  in zipf_next()
60 	eta = (1.0 - pow(2.0 / n, 1.0 - zs->theta)) / (1.0 - zs->zeta2 / zs->zetan);  in zipf_next()
62 	rand_uni = (double) __rand(&zs->rand) / (double) FRAND_MAX;  in zipf_next()
63 	rand_z = rand_uni * zs->zetan;  in zipf_next()
67 	else if (rand_z < (1.0 + pow(0.5, zs->theta)))  in zipf_next()
72 	return (__hash_u64(val - 1) + zs->rand_off) % zs->nranges;  in zipf_next()
75 void pareto_init(struct zipf_state *zs, unsigned long nranges, double h,  in pareto_init()  argument
78 	shared_rand_init(zs, nranges, seed);  in pareto_init()
79 	zs->pareto_pow = log(h) / log(1.0 - h);  in pareto_init()
82 unsigned long long pareto_next(struct zipf_state *zs)  in pareto_next()  argument
84 	double rand = (double) __rand(&zs->rand) / (double) FRAND_MAX;  in pareto_next()
85 	unsigned long long n = zs->nranges - 1;  in pareto_next()
87 	return (__hash_u64(n * pow(rand, zs->pareto_pow)) + zs->rand_off) % zs->nranges;  in pareto_next()