Have the coordinator task publish Batches

processor/signers/src/batch/db.rs

@@ -4,7 +4,7 @@ use serai_in_instructions_primitives::{Batch, SignedBatch};
 use serai_db::{Get, DbTxn, create_db};
 
 create_db! {
-  BatchSigner {
+  SignersBatch {
     ActiveSigningProtocols: (session: Session) -> Vec<u32>,
     Batches: (id: u32) -> Batch,
     SignedBatches: (id: u32) -> SignedBatch,

processor/signers/src/batch/mod.rs

@@ -6,7 +6,7 @@ use frost::dkg::ThresholdKeys;
 use serai_validator_sets_primitives::Session;
 use serai_in_instructions_primitives::{SignedBatch, batch_message};
 
-use serai_db::{DbTxn, Db};
+use serai_db::{Get, DbTxn, Db};
 
 use messages::sign::VariantSignId;
 
@@ -23,6 +23,14 @@ use crate::{
 mod db;
 use db::*;
 
+pub(crate) fn last_acknowledged_batch(getter: &impl Get) -> Option<u32> {
+  LastAcknowledgedBatch::get(getter)
+}
+
+pub(crate) fn signed_batch(getter: &impl Get, id: u32) -> Option<SignedBatch> {
+  SignedBatches::get(getter, id)
+}
+
 // Fetches batches to sign and signs them.
 pub(crate) struct BatchSignerTask<D: Db, E: GroupEncoding> {
   db: D,

processor/signers/src/coordinator/db.rs

@@ -0,0 +1,7 @@
+use serai_db::{Get, DbTxn, create_db};
+
+create_db! {
+  SignersCoordinator {
+    LastPublishedBatch: () -> u32,
+  }
+}

processor/signers/src/coordinator/mod.rs

@@ -10,6 +10,8 @@ use crate::{
   Coordinator,
 };
 
+mod db;
+
 // Fetches messages to send the coordinator and sends them.
 pub(crate) struct CoordinatorTask<D: Db, C: Coordinator> {
   db: D,
@@ -93,7 +95,26 @@ impl<D: Db, C: Coordinator> ContinuallyRan for CoordinatorTask<D, C> {
       }
     }
 
-    // TODO: For max(last acknowledged batch, last published batch) onwards, publish every batch
+    // Publish the signed Batches
+    {
+      let mut txn = self.db.txn();
+      // The last acknowledged Batch may exceed the last Batch we published if we didn't sign for
+      // the prior Batch(es) (and accordingly didn't publish them)
+      let last_batch =
+        crate::batch::last_acknowledged_batch(&txn).max(db::LastPublishedBatch::get(&txn));
+      let mut next_batch = last_batch.map_or(0, |id| id + 1);
+      while let Some(batch) = crate::batch::signed_batch(&txn, next_batch) {
+        iterated = true;
+        db::LastPublishedBatch::set(&mut txn, &batch.batch.id);
+        self
+          .coordinator
+          .publish_batch(batch)
+          .await
+          .map_err(|e| format!("couldn't publish Batch: {e:?}"))?;
+        next_batch += 1;
+      }
+      txn.commit();
+    }
 
     Ok(iterated)
   }

processor/signers/src/lib.rs

@@ -169,7 +169,7 @@ impl<ST: SignableTransaction> Signers<ST> {
           .push(ThresholdKeys::from(ThresholdCore::<ST::Ciphersuite>::read(&mut buf).unwrap()));
       }
 
-      // TODO: Batch signer, cosigner, slash report signers
+      // TODO: Cosigner and slash report signers
 
       let (batch_task, batch_handle) = Task::new();
       tokio::spawn(

processor/signers/src/transaction/db.rs

@@ -3,7 +3,7 @@ use serai_validator_sets_primitives::Session;
 use serai_db::{Get, DbTxn, create_db};
 
 create_db! {
-  TransactionSigner {
+  SignersTransaction {
     ActiveSigningProtocols: (session: Session) -> Vec<[u8; 32]>,
     SerializedSignableTransactions: (id: [u8; 32]) -> Vec<u8>,
     SerializedTransactions: (id: [u8; 32]) -> Vec<u8>,