[zk-token-sdk] Refactor pod `FeeParameters` conversion and remove manual byte conversion for the type (#32149)

* replace `decoded::TransferAmountCiphertext` to `DecodedTransferAmountCiphertext`

* refactor pod convert logic for fee parameters

* remove manual byte conversions for `FeeParameters`

* fix error from rebase

zk-token-sdk/src/instruction/transfer/mod.rs

@@ -8,7 +8,6 @@ use {
         elgamal::ElGamalCiphertext,
         pedersen::{PedersenCommitment, PedersenOpening},
     },
-    arrayref::{array_ref, array_refs},
     curve25519_dalek::scalar::Scalar,
 };
 #[cfg(not(target_os = "solana"))]
@@ -92,24 +91,3 @@ pub struct FeeParameters {
     /// Maximum fee assessed on transfers, expressed as an amount of tokens
     pub maximum_fee: u64,
 }
-
-#[cfg(not(target_os = "solana"))]
-impl FeeParameters {
-    pub fn to_bytes(&self) -> [u8; 10] {
-        let mut bytes = [0u8; 10];
-        bytes[..2].copy_from_slice(&self.fee_rate_basis_points.to_le_bytes());
-        bytes[2..10].copy_from_slice(&self.maximum_fee.to_le_bytes());
-
-        bytes
-    }
-
-    pub fn from_bytes(bytes: &[u8]) -> Self {
-        let bytes = array_ref![bytes, 0, 10];
-        let (fee_rate_basis_points, maximum_fee) = array_refs![bytes, 2, 8];
-
-        Self {
-            fee_rate_basis_points: u16::from_le_bytes(*fee_rate_basis_points),
-            maximum_fee: u64::from_le_bytes(*maximum_fee),
-        }
-    }
-}

zk-token-sdk/src/zk_token_elgamal/convert.rs

@@ -53,7 +53,7 @@ mod target_arch {
         crate::{
             curve25519::scalar::PodScalar,
             errors::ProofError,
-            instruction::transfer::{FeeParameters, TransferPubkeys, TransferWithFeePubkeys},
+            instruction::transfer::{TransferPubkeys, TransferWithFeePubkeys},
         },
         curve25519_dalek::{ristretto::CompressedRistretto, scalar::Scalar},
         std::convert::TryFrom,
@@ -132,24 +132,6 @@ mod target_arch {
             })
         }
     }
-
-    impl From<FeeParameters> for pod::FeeParameters {
-        fn from(parameters: FeeParameters) -> Self {
-            Self {
-                fee_rate_basis_points: parameters.fee_rate_basis_points.into(),
-                maximum_fee: parameters.maximum_fee.into(),
-            }
-        }
-    }
-
-    impl From<pod::FeeParameters> for FeeParameters {
-        fn from(pod: pod::FeeParameters) -> Self {
-            Self {
-                fee_rate_basis_points: pod.fee_rate_basis_points.into(),
-                maximum_fee: pod.maximum_fee.into(),
-            }
-        }
-    }
 }
 
 #[cfg(target_os = "solana")]

zk-token-sdk/src/zk_token_elgamal/pod/instruction.rs

@@ -70,3 +70,23 @@ pub struct FeeParameters {
     /// Maximum fee assessed on transfers, expressed as an amount of tokens
     pub maximum_fee: PodU64,
 }
+
+#[cfg(not(target_os = "solana"))]
+impl From<decoded::FeeParameters> for FeeParameters {
+    fn from(decoded_fee_parameters: decoded::FeeParameters) -> Self {
+        FeeParameters {
+            fee_rate_basis_points: decoded_fee_parameters.fee_rate_basis_points.into(),
+            maximum_fee: decoded_fee_parameters.maximum_fee.into(),
+        }
+    }
+}
+
+#[cfg(not(target_os = "solana"))]
+impl From<FeeParameters> for decoded::FeeParameters {
+    fn from(pod_fee_parameters: FeeParameters) -> Self {
+        decoded::FeeParameters {
+            fee_rate_basis_points: pod_fee_parameters.fee_rate_basis_points.into(),
+            maximum_fee: pod_fee_parameters.maximum_fee.into(),
+        }
+    }
+}