From 5650885dca7113a5845964f02ba827063b5a6f08 Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@cryptogams.org>
Date: Mon, 27 May 2024 10:03:12 +0200
Subject: [PATCH] bindings/rust: add MultiPoint trait.

This allows application to perform multi-point operations directly on
arrays of affine points without going through p{1,2}_affines class.
---
 bindings/rust/src/lib.rs              |  7 ++++++
 bindings/rust/src/pippenger-no_std.rs | 29 ++++++++++++++++-------
 bindings/rust/src/pippenger.rs        | 33 +++++++++++++++++++--------
 3 files changed, 51 insertions(+), 18 deletions(-)

diff --git a/bindings/rust/src/lib.rs b/bindings/rust/src/lib.rs
index 6f68ccdc..49dac393 100644
--- a/bindings/rust/src/lib.rs
+++ b/bindings/rust/src/lib.rs
@@ -1971,6 +1971,13 @@ pub mod min_sig {
     );
 }
 
+pub trait MultiPoint {
+    type Output;
+
+    fn mult(&self, scalars: &[u8], nbits: usize) -> Self::Output;
+    fn add(&self) -> Self::Output;
+}
+
 #[cfg(feature = "std")]
 include!("pippenger.rs");
 
diff --git a/bindings/rust/src/pippenger-no_std.rs b/bindings/rust/src/pippenger-no_std.rs
index c316e87a..24249708 100644
--- a/bindings/rust/src/pippenger-no_std.rs
+++ b/bindings/rust/src/pippenger-no_std.rs
@@ -59,16 +59,29 @@ macro_rules! pippenger_mult_impl {
                 ret
             }
 
+            #[inline]
             pub fn mult(&self, scalars: &[u8], nbits: usize) -> $point {
-                let npoints = self.points.len();
+                self.as_slice().mult(scalars, nbits)
+            }
+
+            #[inline]
+            pub fn add(&self) -> $point {
+                self.as_slice().add()
+            }
+        }
+
+        impl MultiPoint for [$point_affine] {
+            type Output = $point;
+
+            fn mult(&self, scalars: &[u8], nbits: usize) -> $point {
+                let npoints = self.len();
                 let nbytes = (nbits + 7) / 8;
 
                 if scalars.len() < nbytes * npoints {
                     panic!("scalars length mismatch");
                 }
 
-                let p: [*const $point_affine; 2] =
-                    [&self.points[0], ptr::null()];
+                let p: [*const $point_affine; 2] = [&self[0], ptr::null()];
                 let s: [*const u8; 2] = [&scalars[0], ptr::null()];
 
                 let mut ret = <$point>::default();
@@ -89,10 +102,10 @@ macro_rules! pippenger_mult_impl {
                 ret
             }
 
-            pub fn add(&self) -> $point {
-                let npoints = self.points.len();
+            fn add(&self) -> $point {
+                let npoints = self.len();
 
-                let p: [*const _; 2] = [&self.points[0], ptr::null()];
+                let p: [*const _; 2] = [&self[0], ptr::null()];
                 let mut ret = <$point>::default();
                 unsafe { $add(&mut ret, &p[0], npoints) };
 
@@ -125,7 +138,7 @@ pippenger_mult_impl!(
     blst_p1s_tile_pippenger,
     blst_p1_add_or_double,
     blst_p1_double,
-    p1_multi_scalar,
+    p1_multi_point,
     blst_p1_generator,
     blst_p1_mult,
     blst_p1s_add,
@@ -141,7 +154,7 @@ pippenger_mult_impl!(
     blst_p2s_tile_pippenger,
     blst_p2_add_or_double,
     blst_p2_double,
-    p2_multi_scalar,
+    p2_multi_point,
     blst_p2_generator,
     blst_p2_mult,
     blst_p2s_add,
diff --git a/bindings/rust/src/pippenger.rs b/bindings/rust/src/pippenger.rs
index bdaec95a..2932e6a6 100644
--- a/bindings/rust/src/pippenger.rs
+++ b/bindings/rust/src/pippenger.rs
@@ -113,8 +113,22 @@ macro_rules! pippenger_mult_impl {
                 ret
             }
 
+            #[inline]
             pub fn mult(&self, scalars: &[u8], nbits: usize) -> $point {
-                let npoints = self.points.len();
+                self.as_slice().mult(scalars, nbits)
+            }
+
+            #[inline]
+            pub fn add(&self) -> $point {
+                self.as_slice().add()
+            }
+        }
+
+        impl MultiPoint for [$point_affine] {
+            type Output = $point;
+
+            fn mult(&self, scalars: &[u8], nbits: usize) -> $point {
+                let npoints = self.len();
                 let nbytes = (nbits + 7) / 8;
 
                 if scalars.len() < nbytes * npoints {
@@ -124,8 +138,7 @@ macro_rules! pippenger_mult_impl {
                 let pool = mt::da_pool();
                 let ncpus = pool.max_count();
                 if ncpus < 2 || npoints < 32 {
-                    let p: [*const $point_affine; 2] =
-                        [&self.points[0], ptr::null()];
+                    let p: [*const $point_affine; 2] = [&self[0], ptr::null()];
                     let s: [*const u8; 2] = [&scalars[0], ptr::null()];
 
                     unsafe {
@@ -178,7 +191,7 @@ macro_rules! pippenger_mult_impl {
                 }
                 let grid = &grid[..];
 
-                let points = &self.points[..];
+                let points = &self[..];
                 let sz = unsafe { $scratch_sizeof(0) / 8 };
 
                 let mut row_sync: Vec<AtomicUsize> = Vec::with_capacity(ny);
@@ -262,13 +275,13 @@ macro_rules! pippenger_mult_impl {
                 ret
             }
 
-            pub fn add(&self) -> $point {
-                let npoints = self.points.len();
+            fn add(&self) -> $point {
+                let npoints = self.len();
 
                 let pool = mt::da_pool();
                 let ncpus = pool.max_count();
                 if ncpus < 2 || npoints < 384 {
-                    let p: [*const _; 2] = [&self.points[0], ptr::null()];
+                    let p: [*const _; 2] = [&self[0], ptr::null()];
                     let mut ret = <$point>::default();
                     unsafe { $add(&mut ret, &p[0], npoints) };
                     return ret;
@@ -295,7 +308,7 @@ macro_rules! pippenger_mult_impl {
                             if work >= npoints {
                                 break;
                             }
-                            p[0] = &self.points[work];
+                            p[0] = &self[work];
                             if work + chunk > npoints {
                                 chunk = npoints - work;
                             }
@@ -345,7 +358,7 @@ pippenger_mult_impl!(
     blst_p1s_tile_pippenger,
     blst_p1_add_or_double,
     blst_p1_double,
-    p1_multi_scalar,
+    p1_multi_point,
     blst_p1_generator,
     blst_p1_mult,
     blst_p1s_add,
@@ -361,7 +374,7 @@ pippenger_mult_impl!(
     blst_p2s_tile_pippenger,
     blst_p2_add_or_double,
     blst_p2_double,
-    p2_multi_scalar,
+    p2_multi_point,
     blst_p2_generator,
     blst_p2_mult,
     blst_p2s_add,