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authorPaul Duncan <pabs@pablotron.org>2019-02-05 00:22:15 -0500
committerPaul Duncan <pabs@pablotron.org>2019-02-05 00:22:15 -0500
commitf557d1f49a2914c6084dd18efc783395228d8ce0 (patch)
tree51111fc899f01956cbab948b87c241478576870d /src/km-rand-erand48.c
parentb5065ea43cb13c0b553874305b53963176c70f59 (diff)
downloadkmeans-f557d1f49a2914c6084dd18efc783395228d8ce0.tar.bz2
kmeans-f557d1f49a2914c6084dd18efc783395228d8ce0.zip
mv *.[hc] src/
Diffstat (limited to 'src/km-rand-erand48.c')
-rw-r--r--src/km-rand-erand48.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/km-rand-erand48.c b/src/km-rand-erand48.c
new file mode 100644
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+++ b/src/km-rand-erand48.c
@@ -0,0 +1,89 @@
+#include <stdbool.h> // bool
+#define _DEFAULT_SOURCE
+#include <stdlib.h> // drand48_r()
+#include <stdio.h> // fopen()
+#include "util.h"
+#include "km.h"
+
+// get N get_floats
+static bool
+on_get_floats(
+ km_rand_t * const rs,
+ const size_t num_vals,
+ float * const vals
+) {
+ unsigned short * const data = rs->data;
+
+ // generate results
+ for (size_t i = 0; i < num_vals; i++) {
+ vals[i] = erand48(data);
+ }
+
+ // return success
+ return true;
+}
+
+// fill sizes callback for system random source
+static bool
+on_get_sizes(
+ km_rand_t * const rs,
+ const size_t num_vals,
+ size_t * const vals
+) {
+ unsigned short * const data = rs->data;
+
+ // generate results
+ for (size_t i = 0; i < num_vals; i++) {
+ vals[i] = nrand48(data);
+ }
+
+ // return success
+ return true;
+}
+
+static void
+on_fini(
+ km_rand_t * const rs
+) {
+ unsigned short * data = rs->data;
+
+ // free rng data
+ free(data);
+
+ // clear pointer
+ rs->data = NULL;
+}
+
+// path random source callbacks
+static const km_rand_cbs_t
+ERAND48_RAND_CBS = {
+ .get_floats = on_get_floats,
+ .get_sizes = on_get_sizes,
+ .fini = on_fini,
+};
+
+// init system random source (uses system rand())
+bool
+km_rand_init_erand48(
+ km_rand_t * const rs,
+ const uint64_t seed
+) {
+ // alloc rng data
+ unsigned short * const data = malloc(3 * sizeof(unsigned short));
+ if (!data) {
+ // return failure
+ return false;
+ }
+
+ // populate seed
+ data[0] = seed & 0xffff;
+ data[1] = (seed >> 16) & 0xffff;
+ data[2] = (seed >> 32) & 0xffff;
+
+ // populate context
+ rs->cbs = &ERAND48_RAND_CBS;
+ rs->data = data;
+
+ // return success
+ return true;
+}