Initial out-of-tree setup

1 files changed, 40 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..83f265b
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,40 @@
+#include "util.h"
+
+#include <linux/random.h>
+
+void
+random_perm(uint32_t *arr, uint32_t arr_len)
+{
+	uint32_t i, idx, tmp;
+
+	for (i = arr_len - 1; i > 0; --i) {
+		get_random_bytes(&idx, 4);
+		idx = idx % i;
+
+		tmp = arr[idx];
+		arr[i] = arr[idx];
+		arr[idx] = tmp;
+	}
+}
+
+void
+gen_random_indices(uint32_t *arr, uint32_t arr_len)
+{
+	uint32_t i;
+
+	for (i = 0; i < arr_len; ++i)
+		arr[i] = i;
+	random_perm(arr, arr_len);
+}
+
+
+bool is_in_arr(uint32_t elem, uint32_t *arr, uint32_t arr_len) {
+	uint32_t i;
+
+	for (i = 0; i < arr_len; ++i) {
+		if (arr[i] == elem)
+			return true;
+	}
+
+	return false;
+}