refactor of key-switching & external product

core/src/ggsw_ciphertext.rs

@@ -1,35 +1,31 @@
 use base2k::{
-    Backend, FFT64, MatZnxDft, MatZnxDftAlloc, MatZnxDftOps, MatZnxDftScratch, MatZnxDftToMut, MatZnxDftToRef, Module, ScalarZnx,
-    ScalarZnxDft, ScalarZnxDftToRef, ScalarZnxToRef, Scratch, VecZnx, VecZnxAlloc, VecZnxBig, VecZnxBigOps, VecZnxBigScratch,
-    VecZnxDft, VecZnxDftAlloc, VecZnxDftOps, VecZnxDftToMut, VecZnxDftToRef, VecZnxOps, VecZnxToMut, VecZnxToRef, ZnxInfos,
-    ZnxZero,
+    Backend, FFT64, MatZnxDft, MatZnxDftAlloc, MatZnxDftOps, MatZnxDftToMut, MatZnxDftToRef, Module, ScalarZnx, ScalarZnxDft,
+    ScalarZnxDftToRef, ScalarZnxToRef, Scratch, VecZnxAlloc, VecZnxDft, VecZnxDftAlloc, VecZnxDftOps, VecZnxDftToMut,
+    VecZnxDftToRef, VecZnxOps, ZnxInfos, ZnxZero,
 };
 use sampling::source::Source;
 
 use crate::{
     elem::{GetRow, Infos, SetRow},
-    gglwe_ciphertext::GGLWECiphertext,
     glwe_ciphertext::GLWECiphertext,
     glwe_ciphertext_fourier::GLWECiphertextFourier,
     glwe_plaintext::GLWEPlaintext,
     keys::SecretKeyFourier,
-    keyswitch_key::GLWESwitchingKey,
     utils::derive_size,
-    vec_glwe_product::{VecGLWEProduct, VecGLWEProductScratchSpace},
 };
 
 pub struct GGSWCiphertext<C, B: Backend> {
     pub data: MatZnxDft<C, B>,
-    pub log_base2k: usize,
-    pub log_k: usize,
+    pub basek: usize,
+    pub k: usize,
 }
 
 impl<B: Backend> GGSWCiphertext<Vec<u8>, B> {
-    pub fn new(module: &Module<B>, log_base2k: usize, log_k: usize, rows: usize, rank: usize) -> Self {
+    pub fn new(module: &Module<B>, basek: usize, k: usize, rows: usize, rank: usize) -> Self {
         Self {
-            data: module.new_mat_znx_dft(rows, rank + 1, rank + 1, derive_size(log_base2k, log_k)),
-            log_base2k: log_base2k,
-            log_k: log_k,
+            data: module.new_mat_znx_dft(rows, rank + 1, rank + 1, derive_size(basek, k)),
+            basek: basek,
+            k: k,
         }
     }
 }
@@ -42,11 +38,11 @@ impl<T, B: Backend> Infos for GGSWCiphertext<T, B> {
     }
 
     fn basek(&self) -> usize {
-        self.log_base2k
+        self.basek
     }
 
     fn k(&self) -> usize {
-        self.log_k
+        self.k
     }
 }
 
@@ -82,35 +78,28 @@ impl GGSWCiphertext<Vec<u8>, FFT64> {
             + module.bytes_of_vec_znx_dft(rank + 1, size)
     }
 
-    pub fn keyswitch_scratch_space(
+    pub fn external_product_scratch_space(
         module: &Module<FFT64>,
-        res_size: usize,
-        lhs: usize,
-        rhs: usize,
-        rank_in: usize,
-        rank_out: usize,
+        out_size: usize,
+        in_size: usize,
+        ggsw_size: usize,
+        rank: usize,
     ) -> usize {
-        <GGLWECiphertext<Vec<u8>, FFT64> as VecGLWEProductScratchSpace>::prod_with_vec_glwe_scratch_space(
-            module, res_size, lhs, rhs, rank_in, rank_out,
-        )
+        let tmp_in: usize = module.bytes_of_vec_znx_dft(rank + 1, in_size);
+        let tmp_out: usize = module.bytes_of_vec_znx_dft(rank + 1, out_size);
+        let ggsw: usize = GLWECiphertextFourier::external_product_scratch_space(module, out_size, in_size, ggsw_size, rank);
+        tmp_in + tmp_out + ggsw
     }
 
-    pub fn keyswitch_inplace_scratch_space(module: &Module<FFT64>, res_size: usize, rhs: usize, rank: usize) -> usize {
-        <GGLWECiphertext<Vec<u8>, FFT64> as VecGLWEProductScratchSpace>::prod_with_vec_glwe_inplace_scratch_space(
-            module, res_size, rhs, rank,
-        )
-    }
-
-    pub fn external_product_scratch_space(module: &Module<FFT64>, res_size: usize, lhs: usize, rhs: usize, rank: usize) -> usize {
-        <GGSWCiphertext<Vec<u8>, FFT64> as VecGLWEProductScratchSpace>::prod_with_vec_glwe_scratch_space(
-            module, res_size, lhs, rhs, rank, rank,
-        )
-    }
-
-    pub fn external_product_inplace_scratch_space(module: &Module<FFT64>, res_size: usize, rhs: usize, rank: usize) -> usize {
-        <GGSWCiphertext<Vec<u8>, FFT64> as VecGLWEProductScratchSpace>::prod_with_glwe_inplace_scratch_space(
-            module, res_size, rhs, rank,
-        )
+    pub fn external_product_inplace_scratch_space(
+        module: &Module<FFT64>,
+        out_size: usize,
+        ggsw_size: usize,
+        rank: usize,
+    ) -> usize {
+        let tmp: usize = module.bytes_of_vec_znx_dft(rank + 1, out_size);
+        let ggsw: usize = GLWECiphertextFourier::external_product_inplace_scratch_space(module, out_size, ggsw_size, rank);
+        tmp + ggsw
     }
 }
 
@@ -140,7 +129,7 @@ where
         }
 
         let size: usize = self.size();
-        let log_base2k: usize = self.basek();
+        let basek: usize = self.basek();
         let k: usize = self.k();
         let cols: usize = self.rank() + 1;
 
@@ -149,20 +138,20 @@ where
 
         let mut vec_znx_pt: GLWEPlaintext<&mut [u8]> = GLWEPlaintext {
             data: tmp_znx_pt,
-            basek: log_base2k,
+            basek: basek,
             k: k,
         };
 
         let mut vec_znx_ct: GLWECiphertext<&mut [u8]> = GLWECiphertext {
             data: tmp_znx_ct,
-            basek: log_base2k,
+            basek: basek,
             k,
         };
 
         (0..self.rows()).for_each(|row_j| {
             // Adds the scalar_znx_pt to the i-th limb of the vec_znx_pt
             module.vec_znx_add_scalar_inplace(&mut vec_znx_pt, 0, row_j, pt, 0);
-            module.vec_znx_normalize_inplace(log_base2k, &mut vec_znx_pt, 0, scrach_2);
+            module.vec_znx_normalize_inplace(basek, &mut vec_znx_pt, 0, scrach_2);
 
             (0..cols).for_each(|col_i| {
                 // rlwe encrypt of vec_znx_pt into vec_znx_ct
@@ -193,30 +182,6 @@ where
         });
     }
 
-    pub fn keyswitch<DataLhs, DataRhs>(
-        &mut self,
-        module: &Module<FFT64>,
-        lhs: &GGSWCiphertext<DataLhs, FFT64>,
-        rhs: &GLWESwitchingKey<DataRhs, FFT64>,
-        scratch: &mut Scratch,
-    ) where
-        MatZnxDft<DataLhs, FFT64>: MatZnxDftToRef<FFT64>,
-        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
-    {
-        rhs.0.prod_with_vec_glwe(module, self, lhs, scratch);
-    }
-
-    pub fn keyswitch_inplace<DataRhs>(
-        &mut self,
-        module: &Module<FFT64>,
-        rhs: &GLWESwitchingKey<DataRhs, FFT64>,
-        scratch: &mut Scratch,
-    ) where
-        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
-    {
-        rhs.0.prod_with_vec_glwe_inplace(module, self, scratch);
-    }
-
     pub fn external_product<DataLhs, DataRhs>(
         &mut self,
         module: &Module<FFT64>,
@@ -227,7 +192,55 @@ where
         MatZnxDft<DataLhs, FFT64>: MatZnxDftToRef<FFT64>,
         MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
     {
-        rhs.prod_with_vec_glwe(module, self, lhs, scratch);
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(
+                self.rank(),
+                lhs.rank(),
+                "ggsw_out rank: {} != ggsw_in rank: {}",
+                self.rank(),
+                lhs.rank()
+            );
+            assert_eq!(
+                self.rank(),
+                rhs.rank(),
+                "ggsw_in rank: {} != ggsw_apply rank: {}",
+                self.rank(),
+                rhs.rank()
+            );
+        }
+
+        let (tmp_in_data, scratch1) = scratch.tmp_vec_znx_dft(module, lhs.rank() + 1, lhs.size());
+
+        let mut tmp_in: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
+            data: tmp_in_data,
+            basek: lhs.basek(),
+            k: lhs.k(),
+        };
+
+        let (tmp_out_data, scratch2) = scratch1.tmp_vec_znx_dft(module, self.rank() + 1, self.size());
+
+        let mut tmp_out: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
+            data: tmp_out_data,
+            basek: self.basek(),
+            k: self.k(),
+        };
+
+        (0..self.rank() + 1).for_each(|col_i| {
+            (0..self.rows()).for_each(|row_j| {
+                lhs.get_row(module, row_j, col_i, &mut tmp_in);
+                tmp_out.external_product(module, &tmp_in, rhs, scratch2);
+                self.set_row(module, row_j, col_i, &tmp_out);
+            });
+        });
+
+        tmp_out.data.zero();
+
+        (self.rows().min(lhs.rows())..self.rows()).for_each(|row_i| {
+            (0..self.rank() + 1).for_each(|col_j| {
+                self.set_row(module, row_i, col_j, &tmp_out);
+            });
+        });
     }
 
     pub fn external_product_inplace<DataRhs>(
@@ -238,7 +251,32 @@ where
     ) where
         MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
     {
-        rhs.prod_with_vec_glwe_inplace(module, self, scratch);
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(
+                self.rank(),
+                rhs.rank(),
+                "ggsw_out rank: {} != ggsw_apply: {}",
+                self.rank(),
+                rhs.rank()
+            );
+        }
+
+        let (tmp_data, scratch1) = scratch.tmp_vec_znx_dft(module, self.rank() + 1, self.size());
+
+        let mut tmp: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
+            data: tmp_data,
+            basek: self.basek(),
+            k: self.k(),
+        };
+
+        (0..self.rank() + 1).for_each(|col_i| {
+            (0..self.rows()).for_each(|row_j| {
+                self.get_row(module, row_j, col_i, &mut tmp);
+                tmp.external_product_inplace(module, rhs, scratch1);
+                self.set_row(module, row_j, col_i, &tmp);
+            });
+        });
     }
 }
 
@@ -270,73 +308,3 @@ where
         module.vmp_prepare_row(self, row_i, col_j, a);
     }
 }
-
-impl VecGLWEProductScratchSpace for GGSWCiphertext<Vec<u8>, FFT64> {
-    fn prod_with_glwe_scratch_space(
-        module: &Module<FFT64>,
-        res_size: usize,
-        a_size: usize,
-        rgsw_size: usize,
-        rank_in: usize,
-        rank_out: usize,
-    ) -> usize {
-        module.bytes_of_vec_znx_dft(rank_out + 1, rgsw_size)
-            + ((module.bytes_of_vec_znx_dft(rank_in + 1, a_size)
-                + module.vmp_apply_tmp_bytes(
-                    res_size,
-                    a_size,
-                    a_size,
-                    rank_in + 1,
-                    rank_out + 1,
-                    rgsw_size,
-                ))
-                | module.vec_znx_big_normalize_tmp_bytes())
-    }
-}
-
-impl<C> VecGLWEProduct for GGSWCiphertext<C, FFT64>
-where
-    MatZnxDft<C, FFT64>: MatZnxDftToRef<FFT64> + ZnxInfos,
-{
-    fn prod_with_glwe<R, A>(
-        &self,
-        module: &Module<FFT64>,
-        res: &mut GLWECiphertext<R>,
-        a: &GLWECiphertext<A>,
-        scratch: &mut Scratch,
-    ) where
-        VecZnx<R>: VecZnxToMut,
-        VecZnx<A>: VecZnxToRef,
-    {
-        let log_base2k: usize = self.basek();
-
-        #[cfg(debug_assertions)]
-        {
-            assert_eq!(self.rank(), a.rank());
-            assert_eq!(self.rank(), res.rank());
-            assert_eq!(res.basek(), log_base2k);
-            assert_eq!(a.basek(), log_base2k);
-            assert_eq!(self.n(), module.n());
-            assert_eq!(res.n(), module.n());
-            assert_eq!(a.n(), module.n());
-        }
-
-        let cols: usize = self.rank() + 1;
-
-        let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols, self.size()); // Todo optimise
-
-        {
-            let (mut a_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols, a.size());
-            (0..cols).for_each(|col_i| {
-                module.vec_znx_dft(&mut a_dft, col_i, a, col_i);
-            });
-            module.vmp_apply(&mut res_dft, &a_dft, self, scratch2);
-        }
-
-        let res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(res_dft);
-
-        (0..cols).for_each(|i| {
-            module.vec_znx_big_normalize(log_base2k, res, i, &res_big, i, scratch1);
-        });
-    }
-}