lib: move math functions to new module

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 185 insertions, 0 deletions

diff --git a/lib/math.c b/lib/math.c
new file mode 100644
index 0000000..37bd33f
--- /dev/null
+++ b/lib/math.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2020 Jo-Philipp Wich <jo@mein.io>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "../module.h"
+
+#include <math.h>
+#include <sys/time.h>
+
+static const struct ut_ops *ops;
+
+static double
+to_double(struct json_object *v)
+{
+	int64_t n;
+	double d;
+
+	return (ops->cast_number(v, &n, &d) == json_type_double) ? d : (double)n;
+}
+
+static int64_t
+to_int64(struct json_object *v)
+{
+	int64_t n;
+	double d;
+
+	return (ops->cast_number(v, &n, &d) == json_type_double) ? (int64_t)d : n;
+}
+
+static struct json_object *
+ut_abs(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	struct json_object *v = json_object_array_get_idx(args, 0);
+	enum json_type t;
+	int64_t n;
+	double d;
+
+	if (json_object_is_type(v, json_type_null))
+		return ops->new_double(NAN);
+
+	t = ops->cast_number(v, &n, &d);
+
+	if (t == json_type_double)
+		return (isnan(d) || d < 0) ? ops->new_double(-d) : json_object_get(v);
+
+	return (n < 0) ? json_object_new_int64(-n) : json_object_get(v);
+}
+
+static struct json_object *
+ut_atan2(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d1 = to_double(json_object_array_get_idx(args, 0));
+	double d2 = to_double(json_object_array_get_idx(args, 1));
+
+	if (isnan(d1) || isnan(d2))
+		return ops->new_double(NAN);
+
+	return ops->new_double(atan2(d1, d2));
+}
+
+static struct json_object *
+ut_cos(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d = to_double(json_object_array_get_idx(args, 0));
+
+	if (isnan(d))
+		return ops->new_double(NAN);
+
+	return ops->new_double(cos(d));
+}
+
+static struct json_object *
+ut_exp(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d = to_double(json_object_array_get_idx(args, 0));
+
+	if (isnan(d))
+		return ops->new_double(NAN);
+
+	return ops->new_double(exp(d));
+}
+
+static struct json_object *
+ut_log(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d = to_double(json_object_array_get_idx(args, 0));
+
+	if (isnan(d))
+		return ops->new_double(NAN);
+
+	return ops->new_double(log(d));
+}
+
+static struct json_object *
+ut_sin(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d = to_double(json_object_array_get_idx(args, 0));
+
+	if (isnan(d))
+		return ops->new_double(NAN);
+
+	return ops->new_double(sin(d));
+}
+
+static struct json_object *
+ut_sqrt(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double d = to_double(json_object_array_get_idx(args, 0));
+
+	if (isnan(d))
+		return ops->new_double(NAN);
+
+	return ops->new_double(sqrt(d));
+}
+
+static struct json_object *
+ut_pow(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	double x = to_double(json_object_array_get_idx(args, 0));
+	double y = to_double(json_object_array_get_idx(args, 1));
+
+	if (isnan(x) || isnan(y))
+		return ops->new_double(NAN);
+
+	return ops->new_double(pow(x, y));
+}
+
+static struct json_object *
+ut_rand(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+	struct timeval tv;
+
+	if (!s->srand_called) {
+		gettimeofday(&tv, NULL);
+		srand((tv.tv_sec * 1000) + (tv.tv_usec / 1000));
+
+		s->srand_called = true;
+	}
+
+	return json_object_new_int64(rand());
+}
+
+static struct json_object *
+ut_srand(struct ut_state *s, uint32_t off, struct json_object *args)
+{
+
+	int64_t n = to_int64(json_object_array_get_idx(args, 0));
+
+	srand((unsigned int)n);
+	s->srand_called = true;
+
+	return NULL;
+}
+
+static const struct { const char *name; ut_c_fn *func; } global_fns[] = {
+	{ "abs",		ut_abs },
+	{ "atan2",		ut_atan2 },
+	{ "cos",		ut_cos },
+	{ "exp",		ut_exp },
+	{ "log",		ut_log },
+	{ "sin",		ut_sin },
+	{ "sqrt",		ut_sqrt },
+	{ "pow",		ut_pow },
+	{ "rand",		ut_rand },
+	{ "srand",		ut_srand },
+};
+
+void ut_module_init(const struct ut_ops *ut, struct ut_state *s, struct json_object *scope)
+{
+	ops = ut;
+
+	register_functions(ops, global_fns, scope);
+}