Create per-protocol fees modules.

zcash_client_backend/src/fees.rs

@@ -3,8 +3,8 @@ use zcash_primitives::{
     transaction::{
         components::{
             amount::{Amount, BalanceError},
-            sapling::builder::{SaplingInput, SaplingOutput},
-            transparent::{builder::TransparentInput, TxOut},
+            sapling::fees as sapling,
+            transparent::fees as transparent,
         },
         fees::{FeeRule, FixedFeeRule},
     },
@@ -79,10 +79,10 @@ pub trait ChangeStrategy {
         &self,
         params: &P,
         target_height: BlockHeight,
-        transparent_inputs: &[impl TransparentInput],
-        transparent_outputs: &[TxOut],
-        sapling_inputs: &[impl SaplingInput],
-        sapling_outputs: &[impl SaplingOutput],
+        transparent_inputs: &[impl transparent::InputView],
+        transparent_outputs: &[impl transparent::OutputView],
+        sapling_inputs: &[impl sapling::InputView],
+        sapling_outputs: &[impl sapling::OutputView],
     ) -> Result<TransactionBalance, ChangeError<Self::Error>>;
 }
 
@@ -112,10 +112,10 @@ impl ChangeStrategy for BasicFixedFeeChangeStrategy {
         &self,
         _params: &P,
         _target_height: BlockHeight,
-        transparent_inputs: &[impl TransparentInput],
-        transparent_outputs: &[TxOut],
-        sapling_inputs: &[impl SaplingInput],
-        sapling_outputs: &[impl SaplingOutput],
+        transparent_inputs: &[impl transparent::InputView],
+        transparent_outputs: &[impl transparent::OutputView],
+        sapling_inputs: &[impl sapling::InputView],
+        sapling_outputs: &[impl sapling::OutputView],
     ) -> Result<TransactionBalance, ChangeError<Self::Error>> {
         let overflow = || ChangeError::StrategyError(BalanceError::Overflow);
         let underflow = || ChangeError::StrategyError(BalanceError::Underflow);
@@ -127,7 +127,7 @@ impl ChangeStrategy for BasicFixedFeeChangeStrategy {
             .ok_or_else(overflow)?;
         let t_out = transparent_outputs
             .iter()
-            .map(|t_out| t_out.value)
+            .map(|t_out| t_out.value())
             .sum::<Option<_>>()
             .ok_or_else(overflow)?;
         let sapling_in = sapling_inputs

zcash_primitives/src/transaction/builder.rs

@@ -23,21 +23,21 @@ use crate::{
             amount::Amount,
             sapling::{
                 self,
-                builder::{SaplingBuilder, SaplingInput, SaplingMetadata, SaplingOutput},
-            },
-            transparent::{
-                self,
-                builder::{TransparentBuilder, TransparentInput},
+                builder::{SaplingBuilder, SaplingMetadata},
             },
+            transparent::{self, builder::TransparentBuilder},
         },
         fees::FeeRule,
         sighash::{signature_hash, SignableInput},
         txid::TxIdDigester,
-        Transaction, TransactionData, TxOut, TxVersion, Unauthorized,
+        Transaction, TransactionData, TxVersion, Unauthorized,
     },
     zip32::ExtendedSpendingKey,
 };
 
+#[cfg(feature = "transparent-inputs")]
+use crate::transaction::components::transparent::TxOut;
+
 #[cfg(feature = "zfuture")]
 use crate::{
     extensions::transparent::{ExtensionTxBuilder, ToPayload},
@@ -159,25 +159,25 @@ impl<'a, P, R> Builder<'a, P, R> {
 
     /// Returns the set of transparent inputs currently committed to be consumed
     /// by the transaction.
-    pub fn transparent_inputs(&self) -> &[impl TransparentInput] {
+    pub fn transparent_inputs(&self) -> &[impl transparent::fees::InputView] {
         self.transparent_builder.inputs()
     }
 
     /// Returns the set of transparent outputs currently set to be produced by
     /// the transaction.
-    pub fn transparent_outputs(&self) -> &[TxOut] {
+    pub fn transparent_outputs(&self) -> &[impl transparent::fees::OutputView] {
         self.transparent_builder.outputs()
     }
 
     /// Returns the set of Sapling inputs currently committed to be consumed
     /// by the transaction.
-    pub fn sapling_inputs(&self) -> &[impl SaplingInput] {
+    pub fn sapling_inputs(&self) -> &[impl sapling::fees::InputView] {
         self.sapling_builder.inputs()
     }
 
     /// Returns the set of Sapling outputs currently set to be produced by
     /// the transaction.
-    pub fn sapling_outputs(&self) -> &[impl SaplingOutput] {
+    pub fn sapling_outputs(&self) -> &[impl sapling::fees::OutputView] {
         self.sapling_builder.outputs()
     }
 }

zcash_primitives/src/transaction/components/sapling.rs

@@ -24,6 +24,7 @@ use super::{amount::Amount, GROTH_PROOF_SIZE};
 pub type GrothProofBytes = [u8; GROTH_PROOF_SIZE];
 
 pub mod builder;
+pub mod fees;
 
 pub trait Authorization: Debug {
     type Proof: Clone + Debug;

zcash_primitives/src/transaction/components/sapling/builder.rs

@@ -25,7 +25,7 @@ use crate::{
         components::{
             amount::Amount,
             sapling::{
-                Authorization, Authorized, Bundle, GrothProofBytes, OutputDescription,
+                fees, Authorization, Authorized, Bundle, GrothProofBytes, OutputDescription,
                 SpendDescription,
             },
         },
@@ -60,20 +60,6 @@ impl fmt::Display for Error {
     }
 }
 
-/// A trait that provides a minimized view of a Sapling input suitable for use in
-/// fee and change calculation.
-pub trait SaplingInput {
-    /// The value of the input being spent.
-    fn value(&self) -> Amount;
-}
-
-/// A trait that provides a minimized view of a Sapling output suitable for use in
-/// fee and change calculation.
-pub trait SaplingOutput {
-    /// The value of the output being produced.
-    fn value(&self) -> Amount;
-}
-
 #[derive(Debug, Clone)]
 pub struct SpendDescriptionInfo {
     extsk: ExtendedSpendingKey,
@@ -83,7 +69,7 @@ pub struct SpendDescriptionInfo {
     merkle_path: MerklePath<Node>,
 }
 
-impl SaplingInput for SpendDescriptionInfo {
+impl fees::InputView for SpendDescriptionInfo {
     fn value(&self) -> Amount {
         // An existing note to be spent must have a valid
         // amount value.
@@ -174,7 +160,7 @@ impl SaplingOutputInfo {
     }
 }
 
-impl SaplingOutput for SaplingOutputInfo {
+impl fees::OutputView for SaplingOutputInfo {
     fn value(&self) -> Amount {
         Amount::from_u64(self.note.value).expect("Note values should be checked at construction.")
     }
@@ -257,12 +243,12 @@ impl<P> SaplingBuilder<P> {
 
     /// Returns the list of Sapling inputs that will be consumed by the transaction being
     /// constructed.
-    pub fn inputs(&self) -> &[impl SaplingInput] {
+    pub fn inputs(&self) -> &[impl fees::InputView] {
         &self.spends
     }
 
     /// Returns the Sapling outputs that will be produced by the transaction being constructed
-    pub fn outputs(&self) -> &[impl SaplingOutput] {
+    pub fn outputs(&self) -> &[impl fees::OutputView] {
         &self.outputs
     }
 

zcash_primitives/src/transaction/components/sapling/fees.rs

@@ -0,0 +1,18 @@
+//! Types related to computation of fees and change related to the Sapling components
+//! of a transaction.
+
+use crate::transaction::components::amount::Amount;
+
+/// A trait that provides a minimized view of a Sapling input suitable for use in
+/// fee and change calculation.
+pub trait InputView {
+    /// The value of the input being spent.
+    fn value(&self) -> Amount;
+}
+
+/// A trait that provides a minimized view of a Sapling output suitable for use in
+/// fee and change calculation.
+pub trait OutputView {
+    /// The value of the output being produced.
+    fn value(&self) -> Amount;
+}

zcash_primitives/src/transaction/components/transparent.rs

@@ -10,6 +10,7 @@ use crate::legacy::{Script, TransparentAddress};
 use super::amount::{Amount, BalanceError};
 
 pub mod builder;
+pub mod fees;
 
 pub trait Authorization: Debug {
     type ScriptSig: Debug + Clone + PartialEq;

zcash_primitives/src/transaction/components/transparent/builder.rs

@@ -7,7 +7,7 @@ use crate::{
     transaction::{
         components::{
             amount::Amount,
-            transparent::{self, Authorization, Authorized, Bundle, TxIn, TxOut},
+            transparent::{self, fees, Authorization, Authorized, Bundle, TxIn, TxOut},
         },
         sighash::TransparentAuthorizingContext,
         OutPoint,
@@ -40,22 +40,13 @@ impl fmt::Display for Error {
     }
 }
 
-/// This trait provides a minimized view of a transparent input suitable for use in
-/// fee computation.
-pub trait TransparentInput {
-    /// The outpoint to which the input refers.
-    fn outpoint(&self) -> &OutPoint;
-    /// The previous output being spent.
-    fn coin(&self) -> &TxOut;
-}
-
 /// An uninhabited type that allows the type of [`TransparentBuilder::inputs`]
 /// to resolve when the transparent-inputs feature is not turned on.
 #[cfg(not(feature = "transparent-inputs"))]
 enum InvalidTransparentInput {}
 
 #[cfg(not(feature = "transparent-inputs"))]
-impl TransparentInput for InvalidTransparentInput {
+impl fees::InputView for InvalidTransparentInput {
     fn outpoint(&self) -> &OutPoint {
         panic!("transparent-inputs feature flag is not enabled.");
     }
@@ -74,7 +65,7 @@ struct TransparentInputInfo {
 }
 
 #[cfg(feature = "transparent-inputs")]
-impl TransparentInput for TransparentInputInfo {
+impl fees::InputView for TransparentInputInfo {
     fn outpoint(&self) -> &OutPoint {
         &self.utxo
     }
@@ -118,7 +109,7 @@ impl TransparentBuilder {
 
     /// Returns the list of transparent inputs that will be consumed by the transaction being
     /// constructed.
-    pub fn inputs(&self) -> &[impl TransparentInput] {
+    pub fn inputs(&self) -> &[impl fees::InputView] {
         #[cfg(feature = "transparent-inputs")]
         return &self.inputs;
 
@@ -130,7 +121,7 @@ impl TransparentBuilder {
     }
 
     /// Returns the transparent outputs that will be produced by the transaction being constructed.
-    pub fn outputs(&self) -> &[TxOut] {
+    pub fn outputs(&self) -> &[impl fees::OutputView] {
         &self.vout
     }
 

zcash_primitives/src/transaction/components/transparent/fees.rs

@@ -0,0 +1,36 @@
+//! Types related to computation of fees and change related to the transparent components
+//! of a transaction.
+
+use super::TxOut;
+use crate::{
+    legacy::Script,
+    transaction::{components::amount::Amount, OutPoint},
+};
+
+/// This trait provides a minimized view of a transparent input suitable for use in
+/// fee and change computation.
+pub trait InputView {
+    /// The outpoint to which the input refers.
+    fn outpoint(&self) -> &OutPoint;
+    /// The previous output being spent.
+    fn coin(&self) -> &TxOut;
+}
+
+/// This trait provides a minimized view of a transparent output suitable for use in
+/// fee and change computation.
+pub trait OutputView {
+    /// Returns the value of the output being created.
+    fn value(&self) -> Amount;
+    /// Returns the script corresponding to the newly created output.
+    fn script_pubkey(&self) -> &Script;
+}
+
+impl OutputView for TxOut {
+    fn value(&self) -> Amount {
+        self.value
+    }
+
+    fn script_pubkey(&self) -> &Script {
+        &self.script_pubkey
+    }
+}

zcash_primitives/src/transaction/components/tze.rs

@@ -12,6 +12,7 @@ use super::amount::Amount;
 use crate::{extensions::transparent as tze, transaction::TxId};
 
 pub mod builder;
+pub mod fees;
 
 fn to_io_error(_: std::num::TryFromIntError) -> io::Error {
     io::Error::new(io::ErrorKind::InvalidData, "value out of range")

zcash_primitives/src/transaction/components/tze/builder.rs

@@ -9,7 +9,7 @@ use crate::{
         self as tx,
         components::{
             amount::Amount,
-            tze::{Authorization, Authorized, Bundle, OutPoint, TzeIn, TzeOut},
+            tze::{fees, Authorization, Authorized, Bundle, OutPoint, TzeIn, TzeOut},
         },
     },
 };
@@ -35,20 +35,13 @@ pub struct TzeSigner<'a, BuildCtx> {
     builder: Box<dyn FnOnce(&BuildCtx) -> Result<(u32, Vec<u8>), Error> + 'a>,
 }
 
-/// This trait provides a minimized view of a TZE input suitable for use in
-/// fee computation.
-pub trait TzeInput {
-    fn outpoint(&self) -> &OutPoint;
-    fn coin(&self) -> &TzeOut;
-}
-
 #[derive(Clone)]
 struct TzeBuildInput {
     tzein: TzeIn<()>,
     coin: TzeOut,
 }
 
-impl TzeInput for TzeBuildInput {
+impl fees::InputView for TzeBuildInput {
     fn outpoint(&self) -> &OutPoint {
         &self.tzein.prevout
     }
@@ -79,11 +72,11 @@ impl<'a, BuildCtx> TzeBuilder<'a, BuildCtx> {
         }
     }
 
-    pub fn inputs(&self) -> &[impl TzeInput] {
+    pub fn inputs(&self) -> &[impl fees::InputView] {
         &self.vin
     }
 
-    pub fn outputs(&self) -> &[TzeOut] {
+    pub fn outputs(&self) -> &[impl fees::OutputView] {
         &self.vout
     }
 

zcash_primitives/src/transaction/components/tze/fees.rs

@@ -0,0 +1,37 @@
+//! Abstractions and types related to fee calculations for TZE components of a transaction.
+
+use crate::{
+    extensions::transparent::{self as tze},
+    transaction::components::{
+        amount::Amount,
+        tze::{OutPoint, TzeOut},
+    },
+};
+
+/// This trait provides a minimized view of a TZE input suitable for use in
+/// fee computation.
+pub trait InputView {
+    /// The outpoint to which the input refers.
+    fn outpoint(&self) -> &OutPoint;
+    /// The previous output being consumed.
+    fn coin(&self) -> &TzeOut;
+}
+
+/// This trait provides a minimized view of a TZE output suitable for use in
+/// fee computation.
+pub trait OutputView {
+    /// The value of the newly created output
+    fn value(&self) -> Amount;
+    /// The precondition that must be satisfied in order to spend this output.
+    fn precondition(&self) -> &tze::Precondition;
+}
+
+impl OutputView for TzeOut {
+    fn value(&self) -> Amount {
+        self.value
+    }
+
+    fn precondition(&self) -> &tze::Precondition {
+        &self.precondition
+    }
+}

zcash_primitives/src/transaction/fees.rs

@@ -3,14 +3,12 @@
 use crate::{
     consensus::{self, BlockHeight},
     transaction::components::{
-        amount::Amount,
-        sapling::builder::{SaplingInput, SaplingOutput},
-        transparent::{builder::TransparentInput, TxOut},
+        amount::Amount, sapling::fees as sapling, transparent::fees as transparent,
     },
 };
 
 #[cfg(feature = "zfuture")]
-use crate::transaction::components::tze::{builder::TzeInput, TzeOut};
+use crate::transaction::components::tze::fees as tze;
 
 /// A trait that represents the ability to compute the fees that must be paid
 /// by a transaction having a specified set of inputs and outputs.
@@ -26,10 +24,10 @@ pub trait FeeRule {
         &self,
         params: &P,
         target_height: BlockHeight,
-        transparent_inputs: &[impl TransparentInput],
-        transparent_outputs: &[TxOut],
-        sapling_inputs: &[impl SaplingInput],
-        sapling_outputs: &[impl SaplingOutput],
+        transparent_inputs: &[impl transparent::InputView],
+        transparent_outputs: &[impl transparent::OutputView],
+        sapling_inputs: &[impl sapling::InputView],
+        sapling_outputs: &[impl sapling::OutputView],
     ) -> Result<Amount, Self::Error>;
 }
 
@@ -47,12 +45,12 @@ pub trait FutureFeeRule: FeeRule {
         &self,
         params: &P,
         target_height: BlockHeight,
-        transparent_inputs: &[impl TransparentInput],
-        transparent_outputs: &[TxOut],
-        sapling_inputs: &[impl SaplingInput],
-        sapling_outputs: &[impl SaplingOutput],
-        tze_inputs: &[impl TzeInput],
-        tze_outputs: &[TzeOut],
+        transparent_inputs: &[impl transparent::InputView],
+        transparent_outputs: &[impl transparent::OutputView],
+        sapling_inputs: &[impl sapling::InputView],
+        sapling_outputs: &[impl sapling::OutputView],
+        tze_inputs: &[impl tze::InputView],
+        tze_outputs: &[impl tze::OutputView],
     ) -> Result<Amount, Self::Error>;
 }
 
@@ -76,10 +74,10 @@ impl FeeRule for FixedFeeRule {
         &self,
         _params: &P,
         _target_height: BlockHeight,
-        _transparent_inputs: &[impl TransparentInput],
-        _transparent_outputs: &[TxOut],
-        _sapling_inputs: &[impl SaplingInput],
-        _sapling_outputs: &[impl SaplingOutput],
+        _transparent_inputs: &[impl transparent::InputView],
+        _transparent_outputs: &[impl transparent::OutputView],
+        _sapling_inputs: &[impl sapling::InputView],
+        _sapling_outputs: &[impl sapling::OutputView],
     ) -> Result<Amount, Self::Error> {
         Ok(self.fixed_fee)
     }
@@ -91,12 +89,12 @@ impl FutureFeeRule for FixedFeeRule {
         &self,
         _params: &P,
         _target_height: BlockHeight,
-        _transparent_inputs: &[impl TransparentInput],
-        _transparent_outputs: &[TxOut],
-        _sapling_inputs: &[impl SaplingInput],
-        _sapling_outputs: &[impl SaplingOutput],
-        _tze_inputs: &[impl TzeInput],
-        _tze_outputs: &[TzeOut],
+        _transparent_inputs: &[impl transparent::InputView],
+        _transparent_outputs: &[impl transparent::OutputView],
+        _sapling_inputs: &[impl sapling::InputView],
+        _sapling_outputs: &[impl sapling::OutputView],
+        _tze_inputs: &[impl tze::InputView],
+        _tze_outputs: &[impl tze::OutputView],
     ) -> Result<Amount, Self::Error> {
         Ok(self.fixed_fee)
     }