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sequence.c
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sequence.c
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/**
* FIXME: Check that ndx behaves as expected, and adjust if necessary
*/
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <talloc.h>
#include "sequence.h"
#include "rngod.h"
#include "rng-private.h"
struct rng_seq {
struct rngod rng;
size_t cur;
bool loop;
size_t nitems;
uint64_t *items;
};
static uint64_t
rngod_sequence_method_rand(struct rngod *rng) {
struct rng_seq *rngs = talloc_get_type(rng, struct rng_seq);
if (rngs->cur < rngs->nitems) {
return rngs->items[rngs->cur ++];
}
if (rngs->loop) {
rngs->cur = 0;
return rngs->items[rngs->cur ++];
}
return rngs->items[rngs->nitems - 1];
}
static uint64_t
rngod_sequence_method_range(struct rngod *rng, uint64_t min, uint64_t max) {
if (!rng) return 0;
uint64_t val = rng->rand(rng);
if (val >= min && val <= max) {
return val;
}
int range = max - min + 1;
val = val % range;
val += min;
return val;
}
struct rngod *
rngod_sequence_add(size_t nitems, const uint64_t *items) {
struct rng_seq *rngs;
if (nitems < 1 || items == NULL) return NULL;
rngs = talloc(NULL, struct rng_seq);
if (!rngs) return NULL;
rngs->rng.rand = rngod_sequence_method_rand;
default_init(&rngs->rng);
rngs->rng.range = rngod_sequence_method_range;
rngs->loop = true;
rngs->cur = 0;
rngs->nitems = 0;
rngs->items = NULL;
int rv = rngod_sequence_sequence_set(&rngs->rng, nitems, items);
if (rv != 0) {
talloc_free(rngs);
return NULL;
}
return &rngs->rng;
}
int
rngod_sequence_sequence_set(struct rngod *rng, size_t nitems, const uint64_t *items) {
struct rng_seq *rngs = talloc_get_type(rng, struct rng_seq);
if (rngs->rng.rand != rngod_sequence_method_rand) {
return -1;
}
if (nitems < 1 || items == NULL) return -1;
if (rngs->items) talloc_free(rngs->items);
rngs->items = talloc_array(rngs, uint64_t, nitems);
if (rngs->items == NULL) {
rngs->nitems = 0;
return -1;
}
memcpy(rngs->items, items, nitems * sizeof(uint64_t));
rngs->nitems = nitems;
rngs->cur = 0;
return 0;
}
/**
* Do we repeat the last item, or loop
*/
int
rngod_sequence_loop_set(struct rngod *rng, bool loop) {
struct rng_seq *rngs = talloc_get_type(rng, struct rng_seq);
if (rngs->rng.rand != rngod_sequence_method_rand) {
return -1;
}
rngs->loop = loop;
return 0;
}