chore: use WASMValue for wasm arguments as well as return values (#157

)

chore: use `WASMValue` for wasm args

Co-authored-by: Blaine Bublitz <blaine.bublitz@gmail.com>

src/acvm_interop/smart_contract.rs

@@ -36,7 +36,6 @@ impl SmartContract for Barretenberg {
 impl SmartContract for Barretenberg {
     fn eth_contract_from_vk(&self, verification_key: &[u8]) -> String {
         use crate::wasm::POINTER_BYTES;
-        use wasmer::Value;
 
         let g2 = G2::new();
 
@@ -50,7 +49,7 @@ impl SmartContract for Barretenberg {
         let contract_size = self
             .call_multiple(
                 "acir_proofs_get_solidity_verifier",
-                vec![&g2_ptr, &vk_ptr, &Value::I32(contract_ptr_ptr as i32)],
+                vec![&g2_ptr, &vk_ptr, &contract_ptr_ptr.into()],
             )
             .value();
         let contract_size: usize = contract_size.unwrap_i32() as usize;

src/composer.rs

@@ -211,7 +211,7 @@ impl Composer for Barretenberg {
 
         let circuit_size = self
             .call("acir_proofs_get_total_circuit_size", &cs_ptr)
-            .into_i32();
+            .i32();
         let circuit_size =
             u32::try_from(circuit_size).expect("circuit cannot have negative number of gates");
 
@@ -226,7 +226,7 @@ impl Composer for Barretenberg {
 
         let circuit_size = self
             .call("acir_proofs_get_exact_circuit_size", &cs_ptr)
-            .into_i32();
+            .i32();
         let circuit_size =
             u32::try_from(circuit_size).expect("circuit cannot have negative number of gates");
 
@@ -237,7 +237,6 @@ impl Composer for Barretenberg {
 
     fn compute_proving_key(&self, constraint_system: &ConstraintSystem) -> Vec<u8> {
         use super::wasm::POINTER_BYTES;
-        use wasmer::Value;
 
         let cs_buf = constraint_system.to_bytes();
         let cs_ptr = self.allocate(&cs_buf);
@@ -246,13 +245,11 @@ impl Composer for Barretenberg {
         // `pk_ptr_ptr` is a pointer to a pointer which holds the proving key.
         let pk_ptr_ptr: usize = 0;
 
-        let pk_size = self
-            .call_multiple(
-                "acir_proofs_init_proving_key",
-                vec![&cs_ptr, &Value::I32(pk_ptr_ptr as i32)],
-            )
-            .value();
-        let pk_size: usize = pk_size.unwrap_i32() as usize;
+        let pk_size = self.call_multiple(
+            "acir_proofs_init_proving_key",
+            vec![&cs_ptr, &pk_ptr_ptr.into()],
+        );
+        let pk_size: usize = pk_size.i32() as usize;
 
         // We then need to read the pointer at `pk_ptr_ptr` to get the key's location
         // and then slice memory again at `pk_ptr` to get the proving key.
@@ -269,7 +266,6 @@ impl Composer for Barretenberg {
         proving_key: &[u8],
     ) -> Vec<u8> {
         use super::wasm::POINTER_BYTES;
-        use wasmer::Value;
 
         let circuit_size = self.get_circuit_size(constraint_system);
         let CRS {
@@ -287,12 +283,7 @@ impl Composer for Barretenberg {
         let vk_size = self
             .call_multiple(
                 "acir_proofs_init_verification_key",
-                vec![
-                    &pippenger_ptr,
-                    &g2_ptr,
-                    &pk_ptr,
-                    &Value::I32(vk_ptr_ptr as i32),
-                ],
+                vec![&pippenger_ptr, &g2_ptr, &pk_ptr, &vk_ptr_ptr.into()],
             )
             .value();
         let vk_size: usize = vk_size.unwrap_i32() as usize;
@@ -313,7 +304,6 @@ impl Composer for Barretenberg {
         proving_key: &[u8],
     ) -> Vec<u8> {
         use super::wasm::POINTER_BYTES;
-        use wasmer::Value;
 
         let circuit_size = self.get_circuit_size(constraint_system);
         let CRS {
@@ -341,7 +331,7 @@ impl Composer for Barretenberg {
                     &pk_ptr,
                     &cs_ptr,
                     &witness_ptr,
-                    &Value::I32(0),
+                    &0.into(),
                 ],
             )
             .value();
@@ -369,7 +359,6 @@ impl Composer for Barretenberg {
         public_inputs: Assignments,
         verification_key: &[u8],
     ) -> bool {
-        use wasmer::Value;
         let g2_data = G2::new().data;
 
         // Barretenberg expects public inputs to be prepended onto the proof
@@ -384,13 +373,7 @@ impl Composer for Barretenberg {
         let verified = self
             .call_multiple(
                 "acir_proofs_verify_proof",
-                vec![
-                    &g2_ptr,
-                    &vk_ptr,
-                    &cs_ptr,
-                    &proof_ptr,
-                    &Value::I32(proof.len() as i32),
-                ],
+                vec![&g2_ptr, &vk_ptr, &cs_ptr, &proof_ptr, &proof.len().into()],
             )
             .value();
 

src/lib.rs

@@ -101,19 +101,46 @@ mod wasm {
         memory: Memory,
     }
 
-    /// A wrapper around the return value from a WASM call.
+    /// A wrapper around the arguments or return value from a WASM call.
     /// Notice, `Option<Value>` is used because not every call returns a value,
     /// some calls are simply made to free a pointer or manipulate the heap.
-    #[derive(Debug)]
+    #[derive(Debug, Clone)]
     pub(super) struct WASMValue(Option<Value>);
 
     impl WASMValue {
         pub(super) fn value(self) -> Value {
             self.0.unwrap()
         }
-        pub(super) fn into_i32(self) -> i32 {
+
+        pub(super) fn i32(self) -> i32 {
             i32::try_from(self.0.unwrap()).expect("expected an i32 value")
         }
+
+        pub(super) fn bool(self) -> bool {
+            match self.i32() {
+                0 => false,
+                1 => true,
+                _ => panic!("expected a boolean value"),
+            }
+        }
+    }
+
+    impl From<usize> for WASMValue {
+        fn from(value: usize) -> Self {
+            WASMValue(Some(Value::I32(value as i32)))
+        }
+    }
+
+    impl From<i32> for WASMValue {
+        fn from(value: i32) -> Self {
+            WASMValue(Some(Value::I32(value)))
+        }
+    }
+
+    impl From<Value> for WASMValue {
+        fn from(value: Value) -> Self {
+            WASMValue(Some(value))
+        }
     }
 
     impl Barretenberg {
@@ -156,38 +183,39 @@ mod wasm {
                 .collect();
         }
 
-        pub(super) fn call(&self, name: &str, param: &Value) -> WASMValue {
+        pub(super) fn call(&self, name: &str, param: &WASMValue) -> WASMValue {
             self.call_multiple(name, vec![param])
         }
 
-        pub(super) fn call_multiple(&self, name: &str, params: Vec<&Value>) -> WASMValue {
+        pub(super) fn call_multiple(&self, name: &str, params: Vec<&WASMValue>) -> WASMValue {
             // We take in a reference to values, since they do not implement Copy.
             // We then clone them inside of this function, so that the API does not have a bunch of Clones everywhere
 
-            let params: Vec<_> = params.into_iter().cloned().collect();
+            let params: Vec<Value> = params
+                .into_iter()
+                .map(|param| param.clone().value())
+                .collect();
             let func = self.instance.exports.get_function(name).unwrap();
             let option_value = func.call(&params).unwrap().first().cloned();
 
             WASMValue(option_value)
         }
 
         /// Creates a pointer and allocates the bytes that the pointer references to, to the heap
-        pub(super) fn allocate(&self, bytes: &[u8]) -> Value {
-            let ptr = self
-                .call("bbmalloc", &Value::I32(bytes.len() as i32))
-                .value();
+        pub(super) fn allocate(&self, bytes: &[u8]) -> WASMValue {
+            let ptr = self.call("bbmalloc", &bytes.len().into()).value();
 
             let i32_bytes = ptr.unwrap_i32().to_be_bytes();
             let u32_bytes = u32::from_be_bytes(i32_bytes);
 
             self.transfer_to_heap(bytes, u32_bytes as usize);
-            ptr
+            ptr.into()
         }
 
         /// Frees a pointer.
         /// Notice we consume the Value, if you clone the value before passing it to free
         /// It most likely is a bug
-        pub(super) fn free(&self, pointer: Value) {
+        pub(super) fn free(&self, pointer: WASMValue) {
             self.call("bbfree", &pointer);
         }
     }

src/pedersen.rs

@@ -52,7 +52,6 @@ impl Pedersen for Barretenberg {
 impl Pedersen for Barretenberg {
     fn compress_native(&self, left: &FieldElement, right: &FieldElement) -> FieldElement {
         use super::FIELD_BYTES;
-        use wasmer::Value;
 
         let lhs_ptr: usize = 0;
         let rhs_ptr: usize = lhs_ptr + FIELD_BYTES;
@@ -63,11 +62,7 @@ impl Pedersen for Barretenberg {
 
         self.call_multiple(
             "pedersen_plookup_compress_fields",
-            vec![
-                &Value::I32(lhs_ptr as i32),
-                &Value::I32(rhs_ptr as i32),
-                &Value::I32(result_ptr as i32),
-            ],
+            vec![&lhs_ptr.into(), &rhs_ptr.into(), &result_ptr.into()],
         );
 
         let result_bytes = self.slice_memory(result_ptr, FIELD_BYTES);
@@ -78,15 +73,14 @@ impl Pedersen for Barretenberg {
     fn compress_many(&self, inputs: Vec<FieldElement>) -> FieldElement {
         use super::FIELD_BYTES;
         use crate::barretenberg_structures::Assignments;
-        use wasmer::Value;
 
         let input_buf = Assignments::from(inputs).to_bytes();
         let input_ptr = self.allocate(&input_buf);
         let result_ptr: usize = 0;
 
         self.call_multiple(
             "pedersen_plookup_compress",
-            vec![&input_ptr, &Value::I32(result_ptr as i32)],
+            vec![&input_ptr, &result_ptr.into()],
         );
 
         let result_bytes = self.slice_memory(result_ptr, FIELD_BYTES);
@@ -96,15 +90,14 @@ impl Pedersen for Barretenberg {
     fn encrypt(&self, inputs: Vec<FieldElement>) -> (FieldElement, FieldElement) {
         use super::FIELD_BYTES;
         use crate::barretenberg_structures::Assignments;
-        use wasmer::Value;
 
         let input_buf = Assignments::from(inputs).to_bytes();
         let input_ptr = self.allocate(&input_buf);
         let result_ptr: usize = 0;
 
         self.call_multiple(
             "pedersen_plookup_commit",
-            vec![&input_ptr, &Value::I32(result_ptr as i32)],
+            vec![&input_ptr, &result_ptr.into()],
         );
 
         let result_bytes = self.slice_memory(result_ptr, 2 * FIELD_BYTES);

src/pippenger.rs

@@ -4,7 +4,7 @@ pub(crate) struct Pippenger {
     #[cfg(feature = "native")]
     pippenger_ptr: *mut std::os::raw::c_void,
     #[cfg(not(feature = "native"))]
-    pippenger_ptr: wasmer::Value,
+    pippenger_ptr: crate::wasm::WASMValue,
 }
 
 #[cfg(feature = "native")]
@@ -16,7 +16,7 @@ impl Pippenger {
 
 #[cfg(not(feature = "native"))]
 impl Pippenger {
-    pub(crate) fn pointer(&self) -> wasmer::Value {
+    pub(crate) fn pointer(&self) -> crate::wasm::WASMValue {
         self.pippenger_ptr.clone()
     }
 }
@@ -34,18 +34,12 @@ impl Barretenberg {
 impl Barretenberg {
     pub(crate) fn get_pippenger(&self, crs_data: &[u8]) -> Pippenger {
         use super::FIELD_BYTES;
-        use wasmer::Value;
 
         let num_points = crs_data.len() / (2 * FIELD_BYTES);
 
         let crs_ptr = self.allocate(crs_data);
 
-        let pippenger_ptr = self
-            .call_multiple(
-                "new_pippenger",
-                vec![&crs_ptr, &Value::I32(num_points as i32)],
-            )
-            .value();
+        let pippenger_ptr = self.call_multiple("new_pippenger", vec![&crs_ptr, &num_points.into()]);
 
         self.free(crs_ptr);
 

src/scalar_mul.rs

@@ -26,15 +26,13 @@ impl ScalarMul for Barretenberg {
 #[cfg(not(feature = "native"))]
 impl ScalarMul for Barretenberg {
     fn fixed_base(&self, input: &FieldElement) -> (FieldElement, FieldElement) {
-        use wasmer::Value;
-
         let lhs_ptr: usize = 0;
         let result_ptr: usize = lhs_ptr + FIELD_BYTES;
         self.transfer_to_heap(&input.to_be_bytes(), lhs_ptr);
 
         self.call_multiple(
             "compute_public_key",
-            vec![&Value::I32(lhs_ptr as i32), &Value::I32(result_ptr as i32)],
+            vec![&lhs_ptr.into(), &result_ptr.into()],
         );
 
         let result_bytes = self.slice_memory(result_ptr, 2 * FIELD_BYTES);