wallet-core: Move some functionality from lib's root to notes module

- Add `NOTES_BUFFER_SIZE` to indicate the scratch buffer size for notes
- Add `MAX_INPUT_NOTES`, `phoenix_balance` and `BalanceInfo` under `notes` module
- Remove `MAX_INPUT_NOTES`, `phoenix_balance` and `BalanceInfo` from lib.rs

wallet-core/src/ffi.rs

@@ -39,6 +39,10 @@ use zeroize::Zeroize;
 
 use rkyv::{from_bytes, to_bytes};
 
+/// The size of the scratch buffer used for parsing the notes.
+/// It can roughly contains less than 128 serialized notes.
+const NOTES_BUFFER_SIZE: usize = 96 * 1024;
+
 /// The alignment of the memory allocated by the FFI.
 ///
 /// This is 1 because we're not allocating any complex data structures, and
@@ -126,8 +130,8 @@ pub unsafe fn map_owned(
 
     keys.into_iter().for_each(|mut sk| sk.zeroize());
 
-    let bytes =
-        to_bytes::<_, 4096>(&owned).or(Err(ErrorCode::ArchivingError))?;
+    let bytes = to_bytes::<_, NOTES_BUFFER_SIZE>(&owned)
+        .or(Err(ErrorCode::ArchivingError))?;
 
     let len = bytes.len().to_le_bytes();
 

wallet-core/src/lib.rs

@@ -32,8 +32,8 @@ pub type Seed = [u8; 64];
 
 pub mod prelude {
     //! Re-export of the most commonly used types and traits.
+    pub use crate::input::MAX_INPUT_NOTES;
     pub use crate::keys;
-    pub use crate::{input::MAX_INPUT_NOTES, keys::RNG_SEED};
 }
 
 use alloc::vec::Vec;
@@ -44,62 +44,4 @@ use execution_core::transfer::phoenix::{Note, ViewKey as PhoenixViewKey};
 
 pub use notes::map_owned;
 
-/// Calculate the sum for all the given [`Note`]s that belong to the given
-/// [`PhoenixViewKey`].
-pub fn phoenix_balance<T>(
-    phoenix_vk: &PhoenixViewKey,
-    notes: impl Iterator<Item = T>,
-) -> BalanceInfo
-where
-    T: AsRef<Note>,
-{
-    let mut values: Vec<u64> = notes
-        .filter_map(|note| note.as_ref().value(Some(phoenix_vk)).ok())
-        .collect();
-
-    values.sort_by(|a, b| b.cmp(a));
-
-    let spendable = values.iter().take(input::MAX_INPUT_NOTES).sum();
-    let value =
-        spendable + values.iter().skip(input::MAX_INPUT_NOTES).sum::<u64>();
-
-    BalanceInfo { value, spendable }
-}
-
-/// Information about the balance of a particular key.
-#[derive(Debug, Default, Hash, Clone, Copy, PartialEq, Eq)]
-pub struct BalanceInfo {
-    /// The total value of the balance.
-    pub value: u64,
-    /// The maximum _spendable_ value in a single transaction. This is
-    /// different from `value` since there is a maximum number of notes one can
-    /// spend.
-    pub spendable: u64,
-}
-
-impl Serializable<{ 2 * u64::SIZE }> for BalanceInfo {
-    type Error = dusk_bytes::Error;
-
-    fn from_bytes(buf: &[u8; Self::SIZE]) -> Result<Self, Self::Error>
-    where
-        Self: Sized,
-    {
-        let mut reader = &buf[..];
-
-        let value = u64::from_reader(&mut reader)?;
-        let spendable = u64::from_reader(&mut reader)?;
-
-        Ok(Self { value, spendable })
-    }
-
-    #[allow(unused_must_use)]
-    fn to_bytes(&self) -> [u8; Self::SIZE] {
-        let mut buf = [0u8; Self::SIZE];
-        let mut writer = &mut buf[..];
-
-        writer.write(&self.value.to_bytes());
-        writer.write(&self.spendable.to_bytes());
-
-        buf
-    }
-}
+pub use notes::{map_owned, phoenix_balance, BalanceInfo};

wallet-core/src/notes.rs

@@ -4,17 +4,23 @@
 //
 // Copyright (c) DUSK NETWORK. All rights reserved.
 
-//! Implementations of basic wallet functionalities to create transactions.
+//! Provides functions and types for interacting with notes.
 
 use alloc::vec::Vec;
 use core::ops::Index;
+use dusk_bytes::{DeserializableSlice, Serializable, Write};
+use execution_core::transfer::phoenix::{Note, ViewKey as PhoenixViewKey};
 use execution_core::{
     transfer::phoenix::{NoteLeaf, SecretKey as PhoenixSecretKey},
     BlsScalar,
 };
 
 use rkyv::{Archive, Deserialize, Serialize};
 
+// The maximum amount of input notes that can be spend in one
+// phoenix-transaction
+const MAX_INPUT_NOTES: usize = 4;
+
 /// A collection of notes stored as key-value pairs.
 /// The key is a `BlsScalar` and the value is a `NoteLeaf`.
 /// Duplicates are allowed.
@@ -77,8 +83,6 @@ pub fn map_owned(
     notes.as_ref().iter().fold(
         OwnedList::default(),
         |mut notes_map, note_leaf| {
-            eprintln!("Printing note...");
-            dbg!(note_leaf);
             for sk in keys.as_ref() {
                 if sk.owns(note_leaf.note.stealth_address()) {
                     let nullifier = note_leaf.note.gen_nullifier(sk);
@@ -90,3 +94,62 @@ pub fn map_owned(
         },
     )
 }
+
+/// Calculate the sum for all the given [`Note`]s that belong to the given
+/// [`PhoenixViewKey`].
+pub fn phoenix_balance<T>(
+    phoenix_vk: &PhoenixViewKey,
+    notes: impl Iterator<Item = T>,
+) -> BalanceInfo
+where
+    T: AsRef<Note>,
+{
+    let mut values: Vec<u64> = notes
+        .filter_map(|note| note.as_ref().value(Some(phoenix_vk)).ok())
+        .collect();
+
+    values.sort_by(|a, b| b.cmp(a));
+
+    let spendable = values.iter().take(MAX_INPUT_NOTES).sum();
+    let value = spendable + values.iter().skip(MAX_INPUT_NOTES).sum::<u64>();
+
+    BalanceInfo { value, spendable }
+}
+
+/// Information about the balance of a particular key.
+#[derive(Debug, Default, Hash, Clone, Copy, PartialEq, Eq)]
+pub struct BalanceInfo {
+    /// The total value of the balance.
+    pub value: u64,
+    /// The maximum _spendable_ value in a single transaction. This is
+    /// different from `value` since there is a maximum number of notes one can
+    /// spend.
+    pub spendable: u64,
+}
+
+impl Serializable<{ 2 * u64::SIZE }> for BalanceInfo {
+    type Error = dusk_bytes::Error;
+
+    fn from_bytes(buf: &[u8; Self::SIZE]) -> Result<Self, Self::Error>
+    where
+        Self: Sized,
+    {
+        let mut reader = &buf[..];
+
+        let value = u64::from_reader(&mut reader)?;
+        let spendable = u64::from_reader(&mut reader)?;
+
+        Ok(Self { value, spendable })
+    }
+
+    #[allow(unused_must_use)]
+    fn to_bytes(&self) -> [u8; Self::SIZE] {
+        let mut buf = [0u8; Self::SIZE];
+        let mut writer = &mut buf[..];
+
+        writer.write(&self.value.to_bytes());
+        writer.write(&self.spendable.to_bytes());
+
+        buf
+    }
+}