11 #include "../minmax.h"
14 struct fio_zipf_disk {
20 #define FIO_ZIPF_DISK_MAGIC 0x7a697066
21 #define FIO_ZIPF_DISK_VER 1
22 #define FIO_ZIPF_MAGIC ((FIO_ZIPF_DISK_MAGIC << 16) | FIO_ZIPF_DISK_VER)
24 static void write_zipf(struct zipf_state *zs)
26 struct fio_zipf_disk f;
30 sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
31 fd = open(tmp, O_CREAT | O_WRONLY, 0644);
35 f.ver_magic = __cpu_to_le64(FIO_ZIPF_MAGIC);
36 f.nranges = __cpu_to_le64(zs->nranges);
37 f.zetan = __cpu_to_le64(fio_double_to_uint64(zs->zetan));
38 if (write(fd, &f, sizeof(f)) != sizeof(f))
44 static void zipf_update(struct zipf_state *zs)
48 log_info("fio: generating zetan for theta=%f, ranges=%lu\n", zs->theta, zs->nranges);
50 for (i = 0; i < zs->nranges; i++)
51 zs->zetan += pow(1.0 / (double) (i + 1), zs->theta);
56 static void zipf_load_gen_zeta(struct zipf_state *zs)
58 struct fio_zipf_disk f;
62 sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
63 fd = open(tmp, O_RDONLY);
70 if (read(fd, &f, sizeof(f)) != sizeof(f)) {
77 f.ver_magic = le64_to_cpu(f.ver_magic);
78 f.nranges = le64_to_cpu(f.nranges);
79 f.zetan = le64_to_cpu(f.zetan);
81 if (f.ver_magic != FIO_ZIPF_MAGIC) {
86 zs->zetan = fio_uint64_to_double(f.zetan);
87 zs->nranges = f.nranges;
90 void zipf_init(struct zipf_state *zs, unsigned long nranges, double theta)
94 memset(zs, 0, sizeof(*zs));
96 zs->nranges = nranges;
99 for (i = 1; i <= 2; i++)
100 zs->zeta2 += pow(1.0 / (double) i, zs->theta);
102 init_rand(&zs->rand);
104 zipf_load_gen_zeta(zs);
107 unsigned long long zipf_next(struct zipf_state *zs)
110 double alpha, eta, rand_uni, rand_z;
111 unsigned long long n = zs->nranges;
112 unsigned long long val;
114 alpha = 1.0 / (1.0 - zs->theta);
115 eta = (1.0 - pow(2.0 / n, 1.0 - zs->theta)) / (1.0 - zs->zeta2 / zs->zetan);
117 rand_uni = (double) __rand(&zs->rand) / (double) FRAND_MAX;
118 rand_z = rand_uni * zs->zetan;
122 else if (rand_z < (1.0 + pow(0.5, zs->theta)))
125 val = 1 + (unsigned long long)(n * pow(eta*rand_uni - eta + 1.0, alpha));