#include "zipf.h"
#include "../minmax.h"
#include "../hash.h"
-#include "../os/os.h"
-struct fio_zipf_disk {
- uint64_t ver_magic;
- uint64_t nranges;
- uint64_t zetan;
-};
-
-#define FIO_ZIPF_DISK_MAGIC 0x7a697066
-#define FIO_ZIPF_DISK_VER 1
-#define FIO_ZIPF_MAGIC ((FIO_ZIPF_DISK_MAGIC << 16) | FIO_ZIPF_DISK_VER)
-
-static void write_zipf(struct zipf_state *zs)
-{
- struct fio_zipf_disk f;
- char tmp[80];
- int fd;
-
- sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
- fd = open(tmp, O_CREAT | O_WRONLY, 0644);
- if (fd == -1)
- return;
-
- f.ver_magic = __cpu_to_le64(FIO_ZIPF_MAGIC);
- f.nranges = __cpu_to_le64(zs->nranges);
- f.zetan = __cpu_to_le64(fio_double_to_uint64(zs->zetan));
- if (write(fd, &f, sizeof(f)) != sizeof(f))
- unlink(tmp);
-
- close(fd);
-}
+#define ZIPF_MAX_GEN 10000000UL
static void zipf_update(struct zipf_state *zs)
{
+ unsigned long to_gen;
unsigned int i;
- log_info("fio: generating zetan for theta=%f, ranges=%lu\n", zs->theta, zs->nranges);
+ /*
+ * It can become very costly to generate long sequences. Just cap it at
+ * 10M max, that should be doable in 1-2s on even slow machines.
+ * Precision will take a slight hit, but nothing major.
+ */
+ to_gen = min(zs->nranges, (uint64_t) ZIPF_MAX_GEN);
- for (i = 0; i < zs->nranges; i++)
+ for (i = 0; i < to_gen; i++)
zs->zetan += pow(1.0 / (double) (i + 1), zs->theta);
-
- write_zipf(zs);
}
-static void zipf_load_gen_zeta(struct zipf_state *zs)
+static void shared_rand_init(struct zipf_state *zs, unsigned long nranges,
+ unsigned int seed)
{
- struct fio_zipf_disk f;
- char tmp[80];
- int fd;
-
- sprintf(tmp, "fio.zipf.%f.%llu", zs->theta, (unsigned long long) zs->nranges);
- fd = open(tmp, O_RDONLY);
- if (fd == -1) {
-punt:
- zipf_update(zs);
- return;
- }
-
- if (read(fd, &f, sizeof(f)) != sizeof(f)) {
- close(fd);
- goto punt;
- }
-
- close(fd);
-
- f.ver_magic = le64_to_cpu(f.ver_magic);
- f.nranges = le64_to_cpu(f.nranges);
- f.zetan = le64_to_cpu(f.zetan);
-
- if (f.ver_magic != FIO_ZIPF_MAGIC) {
- unlink(tmp);
- goto punt;
- }
-
- zs->zetan = fio_uint64_to_double(f.zetan);
- zs->nranges = f.nranges;
+ memset(zs, 0, sizeof(*zs));
+ zs->nranges = nranges;
+
+ init_rand_seed(&zs->rand, seed, 0);
+ zs->rand_off = __rand(&zs->rand);
}
-void zipf_init(struct zipf_state *zs, unsigned long nranges, double theta)
+void zipf_init(struct zipf_state *zs, unsigned long nranges, double theta,
+ unsigned int seed)
{
- unsigned int i;
+ shared_rand_init(zs, nranges, seed);
- memset(zs, 0, sizeof(*zs));
-
- zs->nranges = nranges;
zs->theta = theta;
+ zs->zeta2 = pow(1.0, zs->theta) + pow(0.5, zs->theta);
- for (i = 1; i <= 2; i++)
- zs->zeta2 += pow(1.0 / (double) i, zs->theta);
-
- init_rand(&zs->rand);
-
- zipf_load_gen_zeta(zs);
+ zipf_update(zs);
}
unsigned long long zipf_next(struct zipf_state *zs)
{
-
double alpha, eta, rand_uni, rand_z;
unsigned long long n = zs->nranges;
unsigned long long val;
alpha = 1.0 / (1.0 - zs->theta);
eta = (1.0 - pow(2.0 / n, 1.0 - zs->theta)) / (1.0 - zs->zeta2 / zs->zetan);
- rand_uni = (double) __rand(&zs->rand) / (double) FRAND_MAX;
+ rand_uni = (double) __rand(&zs->rand) / (double) FRAND32_MAX;
rand_z = rand_uni * zs->zetan;
if (rand_z < 1.0)
else
val = 1 + (unsigned long long)(n * pow(eta*rand_uni - eta + 1.0, alpha));
- return __hash_long(val - 1) % zs->nranges;
+ return (__hash_u64(val - 1) + zs->rand_off) % zs->nranges;
}
-void pareto_init(struct zipf_state *zs, unsigned long nranges, double h)
+void pareto_init(struct zipf_state *zs, unsigned long nranges, double h,
+ unsigned int seed)
{
- memset(zs, 0, sizeof(*zs));
-
- zs->nranges = nranges;
+ shared_rand_init(zs, nranges, seed);
zs->pareto_pow = log(h) / log(1.0 - h);
-
- init_rand(&zs->rand);
}
unsigned long long pareto_next(struct zipf_state *zs)
{
- double rand = (double) __rand(&zs->rand) / (double) FRAND_MAX;
+ double rand = (double) __rand(&zs->rand) / (double) FRAND32_MAX;
unsigned long long n = zs->nranges - 1;
- return __hash_long(n * pow(rand, zs->pareto_pow)) % zs->nranges;
+ return (__hash_u64(n * pow(rand, zs->pareto_pow)) + zs->rand_off) % zs->nranges;
}