Outline of the transaction-chaining scheduler

processor/scanner/Cargo.toml

@@ -19,7 +19,6 @@ workspace = true
 [dependencies]
 # Macros
 async-trait = { version = "0.1", default-features = false }
-thiserror = { version = "1", default-features = false }
 
 # Encoders
 hex = { version = "0.4", default-features = false, features = ["std"] }
@@ -37,7 +36,6 @@ serai-db = { path = "../../common/db" }
 
 serai-primitives = { path = "../../substrate/primitives", default-features = false, features = ["std"] }
 serai-in-instructions-primitives = { path = "../../substrate/in-instructions/primitives", default-features = false, features = ["std"] }
-serai-coins-primitives = { path = "../../substrate/coins/primitives", default-features = false, features = ["std"] }
+serai-coins-primitives = { path = "../../substrate/coins/primitives", default-features = false, features = ["std", "borsh"] }
 
-messages = { package = "serai-processor-messages", path = "../messages" }
 primitives = { package = "serai-processor-primitives", path = "../primitives" }

processor/scanner/src/eventuality/mod.rs

@@ -4,7 +4,7 @@ use group::GroupEncoding;
 
 use serai_db::{Get, DbTxn, Db};
 
-use primitives::{task::ContinuallyRan, OutputType, ReceivedOutput, Eventuality, Block};
+use primitives::{task::ContinuallyRan, OutputType, ReceivedOutput, Eventuality, Block, Payment};
 
 use crate::{
   lifetime::LifetimeStage,
@@ -12,7 +12,7 @@ use crate::{
     SeraiKey, OutputWithInInstruction, ReceiverScanData, ScannerGlobalDb, SubstrateToEventualityDb,
     ScanToEventualityDb,
   },
-  BlockExt, ScannerFeed, KeyFor, OutputFor, EventualityFor, Payment, SchedulerUpdate, Scheduler,
+  BlockExt, ScannerFeed, KeyFor, AddressFor, OutputFor, EventualityFor, SchedulerUpdate, Scheduler,
   sort_outputs,
   scan::{next_to_scan_for_outputs_block, queue_output_until_block},
 };
@@ -168,7 +168,10 @@ impl<D: Db, S: ScannerFeed, Sch: Scheduler<S>> EventualityTask<D, S, Sch> {
         let new_eventualities = self.scheduler.fulfill(
           &mut txn,
           &keys_with_stages,
-          burns.into_iter().filter_map(|burn| Payment::try_from(burn).ok()).collect(),
+          burns
+            .into_iter()
+            .filter_map(|burn| Payment::<AddressFor<S>>::try_from(burn).ok())
+            .collect(),
         );
         intake_eventualities::<S>(&mut txn, new_eventualities);
       }

processor/scanner/src/lib.rs

@@ -5,11 +5,11 @@ use group::GroupEncoding;
 
 use serai_db::{Get, DbTxn, Db};
 
-use serai_primitives::{NetworkId, Coin, Amount, Balance, Data};
+use serai_primitives::{NetworkId, Coin, Amount};
 use serai_in_instructions_primitives::Batch;
 use serai_coins_primitives::OutInstructionWithBalance;
 
-use primitives::{task::*, Address, ReceivedOutput, Block};
+use primitives::{task::*, Address, ReceivedOutput, Block, Payment};
 
 // Logic for deciding where in its lifetime a multisig is.
 mod lifetime;
@@ -195,6 +195,16 @@ impl<S: ScannerFeed> Return<S> {
     let output = OutputFor::<S>::read(reader)?;
     Ok(Return { address, output })
   }
+
+  /// The address to return the output to.
+  pub fn address(&self) -> &AddressFor<S> {
+    &self.address
+  }
+
+  /// The output to return.
+  pub fn output(&self) -> &OutputFor<S> {
+    &self.output
+  }
 }
 
 /// An update for the scheduler.
@@ -219,40 +229,6 @@ impl<S: ScannerFeed> SchedulerUpdate<S> {
   }
 }
 
-/// A payment to fulfill.
-#[derive(Clone)]
-pub struct Payment<S: ScannerFeed> {
-  address: AddressFor<S>,
-  balance: Balance,
-  data: Option<Vec<u8>>,
-}
-
-impl<S: ScannerFeed> TryFrom<OutInstructionWithBalance> for Payment<S> {
-  type Error = ();
-  fn try_from(out_instruction_with_balance: OutInstructionWithBalance) -> Result<Self, ()> {
-    Ok(Payment {
-      address: out_instruction_with_balance.instruction.address.try_into().map_err(|_| ())?,
-      balance: out_instruction_with_balance.balance,
-      data: out_instruction_with_balance.instruction.data.map(Data::consume),
-    })
-  }
-}
-
-impl<S: ScannerFeed> Payment<S> {
-  /// The address to pay.
-  pub fn address(&self) -> &AddressFor<S> {
-    &self.address
-  }
-  /// The balance to transfer.
-  pub fn balance(&self) -> Balance {
-    self.balance
-  }
-  /// The data to associate with this payment.
-  pub fn data(&self) -> &Option<Vec<u8>> {
-    &self.data
-  }
-}
-
 /// The object responsible for accumulating outputs and planning new transactions.
 pub trait Scheduler<S: ScannerFeed>: 'static + Send {
   /// Activate a key.
@@ -327,7 +303,7 @@ pub trait Scheduler<S: ScannerFeed>: 'static + Send {
     &mut self,
     txn: &mut impl DbTxn,
     active_keys: &[(KeyFor<S>, LifetimeStage)],
-    payments: Vec<Payment<S>>,
+    payments: Vec<Payment<AddressFor<S>>>,
   ) -> HashMap<Vec<u8>, Vec<EventualityFor<S>>>;
 }
 

processor/scanner/src/lifetime.rs

@@ -6,7 +6,7 @@ use crate::ScannerFeed;
 /// rotation process. Steps 7-8 regard a multisig which isn't retiring yet retired, and
 /// accordingly, no longer exists, so they are not modelled here (as this only models active
 /// multisigs. Inactive multisigs aren't represented in the first place).
-#[derive(Clone, Copy, PartialEq)]
+#[derive(Clone, Copy, PartialEq, Debug)]
 pub enum LifetimeStage {
   /// A new multisig, once active, shouldn't actually start receiving coins until several blocks
   /// later. If any UI is premature in sending to this multisig, we delay to report the outputs to