zcash_client_backend: Factor out a common type from `WalletSaplingOut…

…put` and `WalletOrchardOutput`.

zcash_client_backend/CHANGELOG.md

@@ -71,7 +71,8 @@ and this library adheres to Rust's notion of
   - `Note`
   - `ReceivedNote`
   - `Recipient::{map_internal_account, internal_account_transpose_option}`
-  - `WalletSaplingOutput::recipient_key_scope`
+  - `WalletOutput`
+  - `WalletSaplingOutput::key_source`
   - `WalletOrchardOutput` behind the `orchard` feature flag.
   - `WalletSpend` 
   - `WalletTx::{orchard_spends, orchard_outputs}` behind the `orchard` feature flag.

zcash_client_backend/src/wallet.rs

@@ -272,29 +272,27 @@ impl KeySource {
     }
 }
 
-/// A subset of an [`OutputDescription`] relevant to wallets and light clients.
-///
-/// [`OutputDescription`]: sapling::bundle::OutputDescription
-pub struct WalletSaplingOutput {
+/// An output that was successfully decrypted in the process of wallet scanning.
+pub struct WalletOutput<Note, Nullifier> {
     index: usize,
     ephemeral_key: EphemeralKeyBytes,
-    note: sapling::Note,
+    note: Note,
     is_change: bool,
     note_commitment_tree_position: Position,
-    nf: Option<sapling::Nullifier>,
+    nf: Option<Nullifier>,
     key_source: KeySource,
 }
 
-impl WalletSaplingOutput {
+impl<Note, Nullifier> WalletOutput<Note, Nullifier> {
     /// Constructs a new `WalletSaplingOutput` value from its constituent parts.
     #[allow(clippy::too_many_arguments)]
     pub fn from_parts(
         index: usize,
         ephemeral_key: EphemeralKeyBytes,
-        note: sapling::Note,
+        note: Note,
         is_change: bool,
         note_commitment_tree_position: Position,
-        nf: Option<sapling::Nullifier>,
+        nf: Option<Nullifier>,
         key_source: KeySource,
     ) -> Self {
         Self {
@@ -308,29 +306,29 @@ impl WalletSaplingOutput {
         }
     }
 
-    /// The index of the output in the transaction that created this output.
+    /// The index of the output or action in the transaction that created this output.
     pub fn index(&self) -> usize {
         self.index
     }
-    /// The [`EphemeralKeyBytes`] of the transaction output.
+    /// The [`EphemeralKeyBytes`] value of the transaction output.
     pub fn ephemeral_key(&self) -> &EphemeralKeyBytes {
         &self.ephemeral_key
     }
     /// The note.
-    pub fn note(&self) -> &sapling::Note {
+    pub fn note(&self) -> &Note {
         &self.note
     }
     /// A flag indicating whether the process of note decryption determined that this
     /// output should be classified as change.
     pub fn is_change(&self) -> bool {
         self.is_change
     }
-    /// The position of the note in the global Sapling note commitment tree.
+    /// The position of the note in the global note commitment tree.
     pub fn note_commitment_tree_position(&self) -> Position {
         self.note_commitment_tree_position
     }
     /// The nullifier for the note, if the key used to decrypt the note was able to compute it.
-    pub fn nf(&self) -> Option<&sapling::Nullifier> {
+    pub fn nf(&self) -> Option<&Nullifier> {
         self.nf.as_ref()
     }
     /// Source metadata for the key that decrypted this note.
@@ -339,74 +337,16 @@ impl WalletSaplingOutput {
     }
 }
 
-#[cfg(feature = "orchard")]
-pub struct WalletOrchardOutput {
-    index: usize,
-    ephemeral_key: EphemeralKeyBytes,
-    note: orchard::note::Note,
-    is_change: bool,
-    note_commitment_tree_position: Position,
-    nf: Option<orchard::note::Nullifier>,
-    key_source: KeySource,
-}
+/// A subset of an [`OutputDescription`] relevant to wallets and light clients.
+///
+/// [`OutputDescription`]: sapling::bundle::OutputDescription
+pub type WalletSaplingOutput = WalletOutput<sapling::Note, sapling::Nullifier>;
 
 /// The output part of an Orchard [`Action`] that was decrypted in the process of scanning.
 ///
 /// [`Action`]: orchard::Action
 #[cfg(feature = "orchard")]
-impl WalletOrchardOutput {
-    /// Constructs a new `WalletOrchardOutput` value from its constituent parts.
-    #[allow(clippy::too_many_arguments)]
-    pub fn from_parts(
-        index: usize,
-        ephemeral_key: EphemeralKeyBytes,
-        note: orchard::note::Note,
-        is_change: bool,
-        note_commitment_tree_position: Position,
-        nf: Option<orchard::note::Nullifier>,
-        key_source: KeySource,
-    ) -> Self {
-        Self {
-            index,
-            ephemeral_key,
-            note,
-            is_change,
-            note_commitment_tree_position,
-            nf,
-            key_source,
-        }
-    }
-
-    /// The index of the Orchard action in the transaction that created this output.
-    pub fn index(&self) -> usize {
-        self.index
-    }
-    /// The [`EphemeralKeyBytes`] of the transaction output.
-    pub fn ephemeral_key(&self) -> &EphemeralKeyBytes {
-        &self.ephemeral_key
-    }
-    /// The note.
-    pub fn note(&self) -> &orchard::note::Note {
-        &self.note
-    }
-    /// A flag indicating whether the process of note decryption determined that this
-    /// output should be classified as change.
-    pub fn is_change(&self) -> bool {
-        self.is_change
-    }
-    /// The position of the note in the global Orchard note commitment tree.
-    pub fn note_commitment_tree_position(&self) -> Position {
-        self.note_commitment_tree_position
-    }
-    /// The nullifier for the note, if the key used to decrypt the note was able to compute it.
-    pub fn nf(&self) -> Option<&orchard::note::Nullifier> {
-        self.nf.as_ref()
-    }
-    /// Source metadata for the key that decrypted this note.
-    pub fn key_source(&self) -> KeySource {
-        self.key_source
-    }
-}
+pub type WalletOrchardOutput = WalletOutput<orchard::note::Note, orchard::note::Nullifier>;
 
 /// An enumeration of supported shielded note types for use in [`ReceivedNote`]
 #[derive(Debug, Clone, PartialEq, Eq)]