core refactoring (#69)

core/src/decryption/lwe_ct.rs

@@ -0,0 +1,42 @@
+use backend::hal::{
+    api::{ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxNormalizeInplace, ZnxView, ZnxViewMut},
+    layouts::{Backend, DataMut, DataRef, Module, ScratchOwned},
+    oep::{ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl},
+};
+
+use crate::layouts::{Infos, LWECiphertext, LWEPlaintext, LWESecret, SetMetaData};
+
+impl<DataSelf> LWECiphertext<DataSelf>
+where
+    DataSelf: DataRef,
+{
+    pub fn decrypt<DataPt, DataSk, B: Backend>(&self, module: &Module<B>, pt: &mut LWEPlaintext<DataPt>, sk: &LWESecret<DataSk>)
+    where
+        DataPt: DataMut,
+        DataSk: DataRef,
+        Module<B>: VecZnxNormalizeInplace<B>,
+        B: ScratchOwnedAllocImpl<B> + ScratchOwnedBorrowImpl<B>,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(self.n(), sk.n());
+        }
+
+        (0..pt.size().min(self.size())).for_each(|i| {
+            pt.data.at_mut(0, i)[0] = self.data.at(0, i)[0]
+                + self.data.at(0, i)[1..]
+                    .iter()
+                    .zip(sk.data.at(0, 0))
+                    .map(|(x, y)| x * y)
+                    .sum::<i64>();
+        });
+        module.vec_znx_normalize_inplace(
+            self.basek(),
+            &mut pt.data,
+            0,
+            ScratchOwned::alloc(size_of::<i64>()).borrow(),
+        );
+        pt.set_basek(self.basek());
+        pt.set_k(self.k().min(pt.size() * self.basek()));
+    }
+}