11 #include "../minmax.h"
15 struct fio_zipf_disk {
21 #define FIO_ZIPF_DISK_MAGIC 0x7a697066
22 #define FIO_ZIPF_DISK_VER 1
23 #define FIO_ZIPF_MAGIC ((FIO_ZIPF_DISK_MAGIC << 16) | FIO_ZIPF_DISK_VER)
25 static void write_zipf(struct zipf_state *zs)
27 struct fio_zipf_disk f;
31 sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
32 fd = open(tmp, O_CREAT | O_WRONLY, 0644);
36 f.ver_magic = __cpu_to_le64(FIO_ZIPF_MAGIC);
37 f.nranges = __cpu_to_le64(zs->nranges);
38 f.zetan = __cpu_to_le64(fio_double_to_uint64(zs->zetan));
39 if (write(fd, &f, sizeof(f)) != sizeof(f))
45 static void zipf_update(struct zipf_state *zs)
49 log_info("fio: generating zetan for theta=%f, ranges=%lu\n", zs->theta, zs->nranges);
51 for (i = 0; i < zs->nranges; i++)
52 zs->zetan += pow(1.0 / (double) (i + 1), zs->theta);
57 static void zipf_load_gen_zeta(struct zipf_state *zs)
59 struct fio_zipf_disk f;
63 sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
64 fd = open(tmp, O_RDONLY);
71 if (read(fd, &f, sizeof(f)) != sizeof(f)) {
78 f.ver_magic = le64_to_cpu(f.ver_magic);
79 f.nranges = le64_to_cpu(f.nranges);
80 f.zetan = le64_to_cpu(f.zetan);
82 if (f.ver_magic != FIO_ZIPF_MAGIC) {
87 zs->zetan = fio_uint64_to_double(f.zetan);
88 zs->nranges = f.nranges;
91 static void shared_rand_init(struct zipf_state *zs, unsigned long nranges)
93 memset(zs, 0, sizeof(*zs));
94 zs->nranges = nranges;
97 zs->rand_off = __rand(&zs->rand);
100 void zipf_init(struct zipf_state *zs, unsigned long nranges, double theta)
104 shared_rand_init(zs, nranges);
108 for (i = 1; i <= 2; i++)
109 zs->zeta2 += pow(1.0 / (double) i, zs->theta);
111 zipf_load_gen_zeta(zs);
114 unsigned long long zipf_next(struct zipf_state *zs)
117 double alpha, eta, rand_uni, rand_z;
118 unsigned long long n = zs->nranges;
119 unsigned long long val;
121 alpha = 1.0 / (1.0 - zs->theta);
122 eta = (1.0 - pow(2.0 / n, 1.0 - zs->theta)) / (1.0 - zs->zeta2 / zs->zetan);
124 rand_uni = (double) __rand(&zs->rand) / (double) FRAND_MAX;
125 rand_z = rand_uni * zs->zetan;
129 else if (rand_z < (1.0 + pow(0.5, zs->theta)))
132 val = 1 + (unsigned long long)(n * pow(eta*rand_uni - eta + 1.0, alpha));
134 return (__hash_long(val - 1) + zs->rand_off) % zs->nranges;
137 void pareto_init(struct zipf_state *zs, unsigned long nranges, double h)
139 shared_rand_init(zs, nranges);
140 zs->pareto_pow = log(h) / log(1.0 - h);
143 unsigned long long pareto_next(struct zipf_state *zs)
145 double rand = (double) __rand(&zs->rand) / (double) FRAND_MAX;
146 unsigned long long n = zs->nranges - 1;
148 return (__hash_long(n * pow(rand, zs->pareto_pow)) + zs->rand_off) % zs->nranges;