token-swap: Changed Wrap SwapCurve's calculator field into Arc instead of Box (#2860)

* box changed to arc

* Imported Arc in all files

* warnings removed

* Updated fuzz

Author: Anurag5086

token-swap/program/fuzz/src/instructions.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use {
     arbitrary::Arbitrary,
     honggfuzz::fuzz,
@@ -459,12 +461,12 @@ fn get_swap_curve(curve_type: CurveType) -> SwapCurve {
     SwapCurve {
         curve_type,
         calculator: match curve_type {
-            CurveType::ConstantProduct => Box::new(ConstantProductCurve),
-            CurveType::ConstantPrice => Box::new(ConstantPriceCurve {
+            CurveType::ConstantProduct => Arc::new(ConstantProductCurve),
+            CurveType::ConstantPrice => Arc::new(ConstantPriceCurve {
                 token_b_price: 10_000_000,
             }),
-            CurveType::Stable => Box::new(StableCurve { amp: 100 }),
-            CurveType::Offset => Box::new(OffsetCurve {
+            CurveType::Stable => Arc::new(StableCurve { amp: 100 }),
+            CurveType::Offset => Arc::new(OffsetCurve {
                 token_b_offset: 100_000_000_000,
             }),
         },

token-swap/program/src/constraints.rs

@@ -7,7 +7,6 @@ use crate::{
     },
     error::SwapError,
 };
-
 use solana_program::program_error::ProgramError;
 
 #[cfg(feature = "production")]
@@ -17,7 +16,7 @@ use std::env;
 /// may be used by multiple frontends, to ensure that proper fees are being
 /// assessed.
 /// Since this struct needs to be created at compile-time, we only have access
-/// to const functions and constructors. Since SwapCurve contains a Box, it
+/// to const functions and constructors. Since SwapCurve contains a Arc, it
 /// cannot be used, so we have to split the curves based on their types.
 pub struct SwapConstraints<'a> {
     /// Owner of the program
@@ -100,8 +99,8 @@ pub const SWAP_CONSTRAINTS: Option<SwapConstraints> = {
 #[cfg(test)]
 mod tests {
     use super::*;
-
     use crate::curve::{base::CurveType, constant_product::ConstantProductCurve};
+    use std::sync::Arc;
 
     #[test]
     fn validate_fees() {
@@ -128,7 +127,7 @@ mod tests {
         let calculator = ConstantProductCurve {};
         let swap_curve = SwapCurve {
             curve_type,
-            calculator: Box::new(calculator.clone()),
+            calculator: Arc::new(calculator.clone()),
         };
         let constraints = SwapConstraints {
             owner_key,
@@ -187,7 +186,7 @@ mod tests {
 
         let swap_curve = SwapCurve {
             curve_type: CurveType::ConstantPrice,
-            calculator: Box::new(calculator),
+            calculator: Arc::new(calculator),
         };
         assert_eq!(
             Err(SwapError::UnsupportedCurveType.into()),

token-swap/program/src/curve/base.rs

@@ -16,6 +16,7 @@ use crate::curve::{
 use arrayref::{array_mut_ref, array_ref, array_refs, mut_array_refs};
 use std::convert::{TryFrom, TryInto};
 use std::fmt::Debug;
+use std::sync::Arc;
 
 #[cfg(feature = "fuzz")]
 use arbitrary::Arbitrary;
@@ -61,7 +62,7 @@ pub struct SwapCurve {
     pub curve_type: CurveType,
     /// The actual calculator, represented as a trait object to allow for many
     /// different types of curves
-    pub calculator: Box<dyn CurveCalculator>,
+    pub calculator: Arc<dyn CurveCalculator>,
 }
 
 impl SwapCurve {
@@ -162,14 +163,14 @@ impl SwapCurve {
 }
 
 /// Default implementation for SwapCurve cannot be derived because of
-/// the contained Box.
+/// the contained Arc.
 impl Default for SwapCurve {
     fn default() -> Self {
         let curve_type: CurveType = Default::default();
         let calculator: ConstantProductCurve = Default::default();
         Self {
             curve_type,
-            calculator: Box::new(calculator),
+            calculator: Arc::new(calculator),
         }
     }
 }
@@ -216,13 +217,13 @@ impl Pack for SwapCurve {
             curve_type,
             calculator: match curve_type {
                 CurveType::ConstantProduct => {
-                    Box::new(ConstantProductCurve::unpack_from_slice(calculator)?)
+                    Arc::new(ConstantProductCurve::unpack_from_slice(calculator)?)
                 }
                 CurveType::ConstantPrice => {
-                    Box::new(ConstantPriceCurve::unpack_from_slice(calculator)?)
+                    Arc::new(ConstantPriceCurve::unpack_from_slice(calculator)?)
                 }
-                CurveType::Stable => Box::new(StableCurve::unpack_from_slice(calculator)?),
-                CurveType::Offset => Box::new(OffsetCurve::unpack_from_slice(calculator)?),
+                CurveType::Stable => Arc::new(StableCurve::unpack_from_slice(calculator)?),
+                CurveType::Offset => Arc::new(OffsetCurve::unpack_from_slice(calculator)?),
             },
         })
     }
@@ -268,7 +269,7 @@ mod tests {
         let curve_type = CurveType::ConstantProduct;
         let swap_curve = SwapCurve {
             curve_type,
-            calculator: Box::new(curve),
+            calculator: Arc::new(curve),
         };
 
         let mut packed = [0u8; SwapCurve::LEN];
@@ -310,7 +311,7 @@ mod tests {
         let curve = ConstantProductCurve {};
         let swap_curve = SwapCurve {
             curve_type: CurveType::ConstantProduct,
-            calculator: Box::new(curve),
+            calculator: Arc::new(curve),
         };
         let result = swap_curve
             .swap(
@@ -355,7 +356,7 @@ mod tests {
         let curve = ConstantProductCurve {};
         let swap_curve = SwapCurve {
             curve_type: CurveType::ConstantProduct,
-            calculator: Box::new(curve),
+            calculator: Arc::new(curve),
         };
         let result = swap_curve
             .swap(
@@ -382,7 +383,7 @@ mod tests {
         let fees = Fees::default();
         let swap_curve = SwapCurve {
             curve_type: CurveType::ConstantProduct,
-            calculator: Box::new(curve),
+            calculator: Arc::new(curve),
         };
         let result = swap_curve
             .swap(

token-swap/program/src/instruction.rs

@@ -566,8 +566,8 @@ pub fn unpack<T>(input: &[u8]) -> Result<&T, ProgramError> {
 #[cfg(test)]
 mod tests {
     use super::*;
-
     use crate::curve::{base::CurveType, stable::StableCurve};
+    use std::sync::Arc;
 
     #[test]
     fn pack_intialize() {
@@ -591,7 +591,7 @@ mod tests {
         };
         let amp: u64 = 1;
         let curve_type = CurveType::Stable;
-        let calculator = Box::new(StableCurve { amp });
+        let calculator = Arc::new(StableCurve { amp });
         let swap_curve = SwapCurve {
             curve_type,
             calculator,