Add ring newtype for easy access of bytes and elements

monero-adaptor/src/lib.rs

@@ -11,6 +11,8 @@ use rand::{CryptoRng, Rng};
 use std::convert::TryInto;
 use tiny_keccak::Hasher;
 
+mod ring;
+
 pub const RING_SIZE: usize = 11;
 const HASH_KEY_CLSAG_AGG_0: &str = "CLSAG_agg_0";
 const HASH_KEY_CLSAG_AGG_1: &str = "CLSAG_agg_1";

monero-adaptor/src/ring.rs

@@ -0,0 +1,35 @@
+use std::ops::Index;
+
+pub struct Ring<T> {
+    elements: [T; 11],
+    bytes: [u8; 32 * 11],
+}
+
+impl<T> Ring<T> {
+    pub fn new(elements: [T; 11], serialize_element: impl Fn(&T) -> &[u8; 32]) -> Ring<T> {
+        let mut bytes = [0u8; 32 * 11];
+
+        for (i, element) in elements.iter().enumerate() {
+            let start = i * 32;
+            let end = (i + 1) * 32;
+
+            bytes[start..end].copy_from_slice(serialize_element(element));
+        }
+
+        Ring { elements, bytes }
+    }
+}
+
+impl<T> AsRef<[u8]> for Ring<T> {
+    fn as_ref(&self) -> &[u8] {
+        self.bytes.as_ref()
+    }
+}
+
+impl<T> Index<usize> for Ring<T> {
+    type Output = T;
+
+    fn index(&self, index: usize) -> &Self::Output {
+        &self.elements[index]
+    }
+}