Convert coordinator/tributary/nonce_decider to use create_db macro (#423)

* chore: convert nonce_deicer to use create_db macro

* Restore pub NonceDecider

* Remove extraneous comma

I forgot to run git commit --amend on the prior commit :/

---------

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

Cargo.lock

@@ -7578,6 +7578,7 @@ dependencies = [
  "serai-env",
  "serai-message-queue",
  "serai-processor-messages",
+ "serde",
  "serde_json",
  "sp-application-crypto",
  "sp-runtime",

coordinator/Cargo.toml

@@ -41,6 +41,7 @@ serai-client = { path = "../substrate/client", default-features = false, feature
 
 hex = { version = "0.4", default-features = false, features = ["std"] }
 bincode = { version = "1", default-features = false }
+serde = "1"
 serde_json = { version = "1", default-features = false, features = ["std"] }
 
 log = { version = "0.4", default-features = false, features = ["std"] }

coordinator/src/main.rs

@@ -740,7 +740,7 @@ async fn handle_processor_message<D: Db, P: P2p>(
 
           let nonce = loop {
             let Some(nonce) =
-              NonceDecider::<D>::nonce(&txn, genesis, &tx).expect("signed TX didn't have nonce")
+              NonceDecider::nonce(&txn, genesis, &tx).expect("signed TX didn't have nonce")
             else {
               // This can be None if the following events occur, in order:
               // 1) We scanned the relevant transaction(s) in a Tributary block

coordinator/src/tributary/handle.rs

@@ -501,7 +501,7 @@ pub(crate) async fn handle_application_tx<
     Transaction::Batch(_, batch) => {
       // Because this Batch has achieved synchrony, its batch ID should be authorized
       TributaryDb::<D>::recognize_topic(txn, genesis, Topic::Batch(batch));
-      let nonce = NonceDecider::<D>::handle_batch(txn, genesis, batch);
+      let nonce = NonceDecider::handle_batch(txn, genesis, batch);
       recognized_id(spec.set(), genesis, RecognizedIdType::Batch, batch.to_vec(), nonce).await;
     }
 
@@ -511,7 +511,7 @@ pub(crate) async fn handle_application_tx<
           despite us not providing that transaction",
       );
 
-      let nonces = NonceDecider::<D>::handle_substrate_block(txn, genesis, &plan_ids);
+      let nonces = NonceDecider::handle_substrate_block(txn, genesis, &plan_ids);
       for (nonce, id) in nonces.into_iter().zip(plan_ids.into_iter()) {
         TributaryDb::<D>::recognize_topic(txn, genesis, Topic::Sign(id));
         recognized_id(spec.set(), genesis, RecognizedIdType::Plan, id.to_vec(), nonce).await;
@@ -534,7 +534,7 @@ pub(crate) async fn handle_application_tx<
       ) {
         Accumulation::Ready(DataSet::Participating(mut preprocesses)) => {
           unflatten(spec, &mut preprocesses);
-          NonceDecider::<D>::selected_for_signing_batch(txn, genesis, data.plan);
+          NonceDecider::selected_for_signing_batch(txn, genesis, data.plan);
           let key = TributaryDb::<D>::key_pair(txn, spec.set()).unwrap().0 .0;
           processors
             .send(
@@ -602,7 +602,7 @@ pub(crate) async fn handle_application_tx<
       ) {
         Accumulation::Ready(DataSet::Participating(mut preprocesses)) => {
           unflatten(spec, &mut preprocesses);
-          NonceDecider::<D>::selected_for_signing_plan(txn, genesis, data.plan);
+          NonceDecider::selected_for_signing_plan(txn, genesis, data.plan);
           processors
             .send(
               spec.set().network,

coordinator/src/tributary/nonce_decider.rs

@@ -1,89 +1,70 @@
-use core::marker::PhantomData;
+use serai_db::{Get, DbTxn, create_db};
-
-use serai_db::{Get, DbTxn, Db};
 
 use crate::tributary::Transaction;
 
-/// Decides the nonce which should be used for a transaction on a Tributary.
+use scale::Encode;
-///
-/// Deterministically builds a list of nonces to use based on the on-chain events and expected
-/// transactions in response. Enables rebooting/rebuilding validators with full safety.
-pub struct NonceDecider<D: Db>(PhantomData<D>);
 
 const BATCH_CODE: u8 = 0;
 const BATCH_SIGNING_CODE: u8 = 1;
 const PLAN_CODE: u8 = 2;
 const PLAN_SIGNING_CODE: u8 = 3;
 
-impl<D: Db> NonceDecider<D> {
+create_db!(
-  fn next_nonce_key(genesis: [u8; 32]) -> Vec<u8> {
+  NonceDeciderDb {
-    D::key(b"coordinator_tributary_nonce", b"next", genesis)
+    NextNonceDb: (genesis: [u8; 32]) -> u32,
+    ItemNonceDb: (genesis: [u8; 32], code: u8, id: &[u8]) -> u32
   }
-  fn allocate_nonce(txn: &mut D::Transaction<'_>, genesis: [u8; 32]) -> u32 {
+);
-    let key = Self::next_nonce_key(genesis);
+
-    let next =
+impl NextNonceDb {
-      txn.get(&key).map(|bytes| u32::from_le_bytes(bytes.try_into().unwrap())).unwrap_or(3);
+  pub fn allocate_nonce(txn: &mut impl DbTxn, genesis: [u8; 32]) -> u32 {
-    txn.put(key, (next + 1).to_le_bytes());
+    let next = Self::get(txn, genesis).unwrap_or(3);
+    Self::set(txn, genesis, &(next + 1));
     next
   }
+}
 
-  fn item_nonce_key(genesis: [u8; 32], code: u8, id: &[u8]) -> Vec<u8> {
+/// Decides the nonce which should be used for a transaction on a Tributary.
-    D::key(
+///
-      b"coordinator_tributary_nonce",
+/// Deterministically builds a list of nonces to use based on the on-chain events and expected
-      b"item",
+/// transactions in response. Enables rebooting/rebuilding validators with full safety.
-      [genesis.as_slice(), [code].as_ref(), id].concat(),
+pub struct NonceDecider;
-    )
+impl NonceDecider {
-  }
+  pub fn handle_batch(txn: &mut impl DbTxn, genesis: [u8; 32], batch: [u8; 5]) -> u32 {
-  fn set_nonce(txn: &mut D::Transaction<'_>, genesis: [u8; 32], code: u8, id: &[u8], nonce: u32) {
+    let nonce_for = NextNonceDb::allocate_nonce(txn, genesis);
-    txn.put(Self::item_nonce_key(genesis, code, id), nonce.to_le_bytes())
+    ItemNonceDb::set(txn, genesis, BATCH_CODE, &batch, &nonce_for);
-  }
-  fn db_nonce<G: Get>(getter: &G, genesis: [u8; 32], code: u8, id: &[u8]) -> Option<u32> {
-    getter
-      .get(Self::item_nonce_key(genesis, code, id))
-      .map(|bytes| u32::from_le_bytes(bytes.try_into().unwrap()))
-  }
-
-  pub fn handle_batch(txn: &mut D::Transaction<'_>, genesis: [u8; 32], batch: [u8; 5]) -> u32 {
-    let nonce_for = Self::allocate_nonce(txn, genesis);
-    Self::set_nonce(txn, genesis, BATCH_CODE, &batch, nonce_for);
     nonce_for
   }
-  // TODO: The processor won't yield shares for this if the signing protocol aborts. We need to
-  // detect when we're expecting shares for an aborted protocol and insert a dummy transaction
-  // there.
-  pub fn selected_for_signing_batch(
-    txn: &mut D::Transaction<'_>,
-    genesis: [u8; 32],
-    batch: [u8; 5],
-  ) {
-    let nonce_for = Self::allocate_nonce(txn, genesis);
-    Self::set_nonce(txn, genesis, BATCH_SIGNING_CODE, &batch, nonce_for);
-  }
 
   pub fn handle_substrate_block(
-    txn: &mut D::Transaction<'_>,
+    txn: &mut impl DbTxn,
     genesis: [u8; 32],
     plans: &[[u8; 32]],
   ) -> Vec<u32> {
     let mut res = Vec::with_capacity(plans.len());
     for plan in plans {
-      let nonce_for = Self::allocate_nonce(txn, genesis);
+      let nonce_for = NextNonceDb::allocate_nonce(txn, genesis);
-      Self::set_nonce(txn, genesis, PLAN_CODE, plan, nonce_for);
+      ItemNonceDb::set(txn, genesis, PLAN_CODE, plan, &nonce_for);
       res.push(nonce_for);
     }
     res
   }
-  // TODO: Same TODO as selected_for_signing_batch
+
-  pub fn selected_for_signing_plan(
+  // TODO: The processor won't yield shares for this if the signing protocol aborts. We need to
-    txn: &mut D::Transaction<'_>,
+  // detect when we're expecting shares for an aborted protocol and insert a dummy transaction
-    genesis: [u8; 32],
+  // there.
-    plan: [u8; 32],
+  pub fn selected_for_signing_batch(txn: &mut impl DbTxn, genesis: [u8; 32], batch: [u8; 5]) {
-  ) {
+    let nonce_for = NextNonceDb::allocate_nonce(txn, genesis);
-    let nonce_for = Self::allocate_nonce(txn, genesis);
+    ItemNonceDb::set(txn, genesis, BATCH_SIGNING_CODE, &batch, &nonce_for);
-    Self::set_nonce(txn, genesis, PLAN_SIGNING_CODE, &plan, nonce_for);
   }
 
-  pub fn nonce<G: Get>(getter: &G, genesis: [u8; 32], tx: &Transaction) -> Option<Option<u32>> {
+  // TODO: Same TODO as selected_for_signing_batch
+  pub fn selected_for_signing_plan(txn: &mut impl DbTxn, genesis: [u8; 32], plan: [u8; 32]) {
+    let nonce_for = NextNonceDb::allocate_nonce(txn, genesis);
+    ItemNonceDb::set(txn, genesis, PLAN_SIGNING_CODE, &plan, &nonce_for);
+  }
+
+  pub fn nonce(getter: &impl Get, genesis: [u8; 32], tx: &Transaction) -> Option<Option<u32>> {
     match tx {
       Transaction::RemoveParticipant(_) => None,
 
@@ -105,28 +86,24 @@ impl<D: Db> NonceDecider<D> {
         assert_eq!(*attempt, 0);
         Some(Some(2))
       }
-
       Transaction::Batch(_, _) => None,
       Transaction::SubstrateBlock(_) => None,
-
       Transaction::BatchPreprocess(data) => {
         assert_eq!(data.attempt, 0);
-        Some(Self::db_nonce(getter, genesis, BATCH_CODE, &data.plan))
+        Some(ItemNonceDb::get(getter, genesis, BATCH_CODE, &data.plan))
       }
       Transaction::BatchShare(data) => {
         assert_eq!(data.attempt, 0);
-        Some(Self::db_nonce(getter, genesis, BATCH_SIGNING_CODE, &data.plan))
+        Some(ItemNonceDb::get(getter, genesis, BATCH_SIGNING_CODE, &data.plan))
       }
-
       Transaction::SignPreprocess(data) => {
         assert_eq!(data.attempt, 0);
-        Some(Self::db_nonce(getter, genesis, PLAN_CODE, &data.plan))
+        Some(ItemNonceDb::get(getter, genesis, PLAN_CODE, &data.plan))
       }
       Transaction::SignShare(data) => {
         assert_eq!(data.attempt, 0);
-        Some(Self::db_nonce(getter, genesis, PLAN_SIGNING_CODE, &data.plan))
+        Some(ItemNonceDb::get(getter, genesis, PLAN_SIGNING_CODE, &data.plan))
       }
-
       Transaction::SignCompleted { .. } => None,
     }
   }