Add cross-basek normalization (#90)

* added cross_basek_normalization

* updated method signatures to take layouts

* fixed cross-base normalization

fix #91
fix #93

poulpy-core/src/layouts/lwe_ct.rs

@@ -1,15 +1,75 @@
 use std::fmt;
 
 use poulpy_hal::{
-    layouts::{Data, DataMut, DataRef, FillUniform, ReaderFrom, Reset, WriterTo, Zn, ZnToMut, ZnToRef, ZnxInfos},
+    layouts::{Data, DataMut, DataRef, FillUniform, ReaderFrom, WriterTo, Zn, ZnToMut, ZnToRef, ZnxInfos},
     source::Source,
 };
 
+use crate::layouts::{Base2K, BuildError, Degree, TorusPrecision};
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+
+pub trait LWEInfos {
+    fn n(&self) -> Degree;
+    fn k(&self) -> TorusPrecision;
+    fn max_k(&self) -> TorusPrecision {
+        TorusPrecision(self.k().0 * self.size() as u32)
+    }
+    fn base2k(&self) -> Base2K;
+    fn size(&self) -> usize {
+        self.k().0.div_ceil(self.base2k().0) as usize
+    }
+    fn lwe_layout(&self) -> LWECiphertextLayout {
+        LWECiphertextLayout {
+            n: self.n(),
+            k: self.k(),
+            base2k: self.base2k(),
+        }
+    }
+}
+
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+pub struct LWECiphertextLayout {
+    pub n: Degree,
+    pub k: TorusPrecision,
+    pub base2k: Base2K,
+}
+
+impl LWEInfos for LWECiphertextLayout {
+    fn base2k(&self) -> Base2K {
+        self.base2k
+    }
+
+    fn k(&self) -> TorusPrecision {
+        self.k
+    }
+
+    fn n(&self) -> Degree {
+        self.n
+    }
+}
+
 #[derive(PartialEq, Eq, Clone)]
 pub struct LWECiphertext<D: Data> {
     pub(crate) data: Zn<D>,
-    pub(crate) k: usize,
-    pub(crate) basek: usize,
+    pub(crate) k: TorusPrecision,
+    pub(crate) base2k: Base2K,
+}
+
+impl<D: Data> LWEInfos for LWECiphertext<D> {
+    fn base2k(&self) -> Base2K {
+        self.base2k
+    }
+
+    fn k(&self) -> TorusPrecision {
+        self.k
+    }
+    fn n(&self) -> Degree {
+        Degree(self.data.n() as u32 - 1)
+    }
+
+    fn size(&self) -> usize {
+        self.data.size()
+    }
 }
 
 impl<D: DataRef> LWECiphertext<D> {
@@ -26,7 +86,7 @@ impl<D: DataMut> LWECiphertext<D> {
 
 impl<D: DataRef> fmt::Debug for LWECiphertext<D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self)
+        write!(f, "{self}")
     }
 }
 
@@ -34,22 +94,14 @@ impl<D: DataRef> fmt::Display for LWECiphertext<D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
             f,
-            "LWECiphertext: basek={} k={}: {}",
-            self.basek(),
-            self.k(),
+            "LWECiphertext: base2k={} k={}: {}",
+            self.base2k().0,
+            self.k().0,
             self.data
         )
     }
 }
 
-impl<D: DataMut> Reset for LWECiphertext<D> {
-    fn reset(&mut self) {
-        self.data.reset();
-        self.basek = 0;
-        self.k = 0;
-    }
-}
-
 impl<D: DataMut> FillUniform for LWECiphertext<D>
 where
     Zn<D>: FillUniform,
@@ -60,45 +112,106 @@ where
 }
 
 impl LWECiphertext<Vec<u8>> {
-    pub fn alloc(n: usize, basek: usize, k: usize) -> Self {
+    pub fn alloc<A>(infos: &A) -> Self
+    where
+        A: LWEInfos,
+    {
+        Self::alloc_with(infos.n(), infos.base2k(), infos.k())
+    }
+
+    pub fn alloc_with(n: Degree, base2k: Base2K, k: TorusPrecision) -> Self {
         Self {
-            data: Zn::alloc(n + 1, 1, k.div_ceil(basek)),
+            data: Zn::alloc((n + 1).into(), 1, k.0.div_ceil(base2k.0) as usize),
             k,
-            basek,
+            base2k,
+        }
+    }
+
+    pub fn alloc_bytes<A>(infos: &A) -> usize
+    where
+        A: LWEInfos,
+    {
+        Self::alloc_bytes_with(infos.n(), infos.base2k(), infos.k())
+    }
+
+    pub fn alloc_bytes_with(n: Degree, base2k: Base2K, k: TorusPrecision) -> usize {
+        Zn::alloc_bytes((n + 1).into(), 1, k.0.div_ceil(base2k.0) as usize)
+    }
+}
+
+impl LWECiphertextBuilder<Vec<u8>> {
+    #[inline]
+    pub fn layout<A>(mut self, layout: A) -> Self
+    where
+        A: LWEInfos,
+    {
+        self.data = Some(Zn::alloc((layout.n() + 1).into(), 1, layout.size()));
+        self.base2k = Some(layout.base2k());
+        self.k = Some(layout.k());
+        self
+    }
+}
+
+pub struct LWECiphertextBuilder<D: Data> {
+    data: Option<Zn<D>>,
+    base2k: Option<Base2K>,
+    k: Option<TorusPrecision>,
+}
+
+impl<D: Data> LWECiphertext<D> {
+    #[inline]
+    pub fn builder() -> LWECiphertextBuilder<D> {
+        LWECiphertextBuilder {
+            data: None,
+            base2k: None,
+            k: None,
         }
     }
 }
 
-impl<D: Data> Infos for LWECiphertext<D>
-where
-    Zn<D>: ZnxInfos,
-{
-    type Inner = Zn<D>;
-
-    fn n(&self) -> usize {
-        &self.inner().n() - 1
+impl<D: Data> LWECiphertextBuilder<D> {
+    #[inline]
+    pub fn data(mut self, data: Zn<D>) -> Self {
+        self.data = Some(data);
+        self
+    }
+    #[inline]
+    pub fn base2k(mut self, base2k: Base2K) -> Self {
+        self.base2k = Some(base2k);
+        self
+    }
+    #[inline]
+    pub fn k(mut self, k: TorusPrecision) -> Self {
+        self.k = Some(k);
+        self
     }
 
-    fn inner(&self) -> &Self::Inner {
-        &self.data
-    }
+    pub fn build(self) -> Result<LWECiphertext<D>, BuildError> {
+        let data: Zn<D> = self.data.ok_or(BuildError::MissingData)?;
+        let base2k: Base2K = self.base2k.ok_or(BuildError::MissingBase2K)?;
+        let k: TorusPrecision = self.k.ok_or(BuildError::MissingK)?;
 
-    fn basek(&self) -> usize {
-        self.basek
-    }
+        if base2k.0 == 0 {
+            return Err(BuildError::ZeroBase2K);
+        }
 
-    fn k(&self) -> usize {
-        self.k
-    }
-}
+        if k.0 == 0 {
+            return Err(BuildError::ZeroTorusPrecision);
+        }
 
-impl<DataSelf: DataMut> SetMetaData for LWECiphertext<DataSelf> {
-    fn set_k(&mut self, k: usize) {
-        self.k = k
-    }
+        if data.n() == 0 {
+            return Err(BuildError::ZeroDegree);
+        }
 
-    fn set_basek(&mut self, basek: usize) {
-        self.basek = basek
+        if data.cols() == 0 {
+            return Err(BuildError::ZeroCols);
+        }
+
+        if data.size() == 0 {
+            return Err(BuildError::ZeroLimbs);
+        }
+
+        Ok(LWECiphertext { data, base2k, k })
     }
 }
 
@@ -108,11 +221,12 @@ pub trait LWECiphertextToRef {
 
 impl<D: DataRef> LWECiphertextToRef for LWECiphertext<D> {
     fn to_ref(&self) -> LWECiphertext<&[u8]> {
-        LWECiphertext {
-            data: self.data.to_ref(),
-            basek: self.basek,
-            k: self.k,
-        }
+        LWECiphertext::builder()
+            .base2k(self.base2k())
+            .k(self.k())
+            .data(self.data.to_ref())
+            .build()
+            .unwrap()
     }
 }
 
@@ -123,30 +237,27 @@ pub trait LWECiphertextToMut {
 
 impl<D: DataMut> LWECiphertextToMut for LWECiphertext<D> {
     fn to_mut(&mut self) -> LWECiphertext<&mut [u8]> {
-        LWECiphertext {
-            data: self.data.to_mut(),
-            basek: self.basek,
-            k: self.k,
-        }
+        LWECiphertext::builder()
+            .base2k(self.base2k())
+            .k(self.k())
+            .data(self.data.to_mut())
+            .build()
+            .unwrap()
     }
 }
 
-use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
-
-use crate::layouts::{Infos, SetMetaData};
-
 impl<D: DataMut> ReaderFrom for LWECiphertext<D> {
     fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
-        self.k = reader.read_u64::<LittleEndian>()? as usize;
-        self.basek = reader.read_u64::<LittleEndian>()? as usize;
+        self.k = TorusPrecision(reader.read_u32::<LittleEndian>()?);
+        self.base2k = Base2K(reader.read_u32::<LittleEndian>()?);
         self.data.read_from(reader)
     }
 }
 
 impl<D: DataRef> WriterTo for LWECiphertext<D> {
     fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
-        writer.write_u64::<LittleEndian>(self.k as u64)?;
-        writer.write_u64::<LittleEndian>(self.basek as u64)?;
+        writer.write_u32::<LittleEndian>(self.k.into())?;
+        writer.write_u32::<LittleEndian>(self.base2k.into())?;
         self.data.write_to(writer)
     }
 }