Rename Report task to Batch task

processor/bin/src/coordinator.rs

@@ -196,18 +196,6 @@ impl signers::Coordinator for CoordinatorSend {
     }
   }
 
-  fn publish_batch(
-    &mut self,
-    batch: Batch,
-  ) -> impl Send + Future<Output = Result<(), Self::EphemeralError>> {
-    async move {
-      self.send(&messages::ProcessorMessage::Substrate(
-        messages::substrate::ProcessorMessage::Batch { batch },
-      ));
-      Ok(())
-    }
-  }
-
   fn publish_signed_batch(
     &mut self,
     batch: SignedBatch,

processor/messages/src/lib.rs

@@ -9,7 +9,7 @@ use dkg::Participant;
 use serai_primitives::BlockHash;
 use validator_sets_primitives::{Session, KeyPair, Slash};
 use coins_primitives::OutInstructionWithBalance;
-use in_instructions_primitives::{Batch, SignedBatch};
+use in_instructions_primitives::SignedBatch;
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, BorshSerialize, BorshDeserialize)]
 pub struct SubstrateContext {
@@ -208,9 +208,17 @@ pub mod substrate {
     },
   }
 
-  #[derive(Clone, PartialEq, Eq, Debug, BorshSerialize, BorshDeserialize)]
-  pub enum ProcessorMessage {
-    Batch { batch: Batch },
+  #[derive(Clone, PartialEq, Eq, Debug)]
+  pub enum ProcessorMessage {}
+  impl BorshSerialize for ProcessorMessage {
+    fn serialize<W: borsh::io::Write>(&self, _writer: &mut W) -> borsh::io::Result<()> {
+      unimplemented!()
+    }
+  }
+  impl BorshDeserialize for ProcessorMessage {
+    fn deserialize_reader<R: borsh::io::Read>(_reader: &mut R) -> borsh::io::Result<Self> {
+      unimplemented!()
+    }
   }
 }
 
@@ -383,15 +391,7 @@ impl ProcessorMessage {
         res.extend(&id);
         res
       }
-      ProcessorMessage::Substrate(msg) => {
-        let (sub, id) = match msg {
-          substrate::ProcessorMessage::Batch { batch } => (0, batch.id.encode()),
-        };
-
-        let mut res = vec![PROCESSOR_UID, TYPE_SUBSTRATE_UID, sub];
-        res.extend(&id);
-        res
-      }
+      ProcessorMessage::Substrate(_) => panic!("requesting intent for empty message type"),
     }
   }
 }

processor/scanner/src/batch/db.rs

@@ -5,11 +5,10 @@ use group::GroupEncoding;
 
 use scale::{Encode, Decode, IoReader};
 use borsh::{BorshSerialize, BorshDeserialize};
-use serai_db::{Get, DbTxn, create_db, db_channel};
+use serai_db::{Get, DbTxn, create_db};
 
 use serai_primitives::Balance;
 use serai_validator_sets_primitives::Session;
-use serai_in_instructions_primitives::Batch;
 
 use primitives::EncodableG;
 use crate::{ScannerFeed, KeyFor, AddressFor};
@@ -23,9 +22,9 @@ pub(crate) struct BatchInfo<K: BorshSerialize> {
 }
 
 create_db!(
-  ScannerReport {
-    // The next block to potentially report
-    NextToPotentiallyReportBlock: () -> u64,
+  ScannerBatch {
+    // The next block to create batches for
+    NextBlockToBatch: () -> u64,
 
     // The last session to sign a Batch and their first Batch signed
     LastSessionToSignBatchAndFirstBatch: () -> (Session, u32),
@@ -41,19 +40,13 @@ create_db!(
   }
 );
 
-db_channel!(
-  ScannerReport {
-    InternalBatches: <G: GroupEncoding>() -> (Session, EncodableG<G>, Batch),
-  }
-);
-
 pub(crate) struct ReturnInformation<S: ScannerFeed> {
   pub(crate) address: AddressFor<S>,
   pub(crate) balance: Balance,
 }
 
-pub(crate) struct ReportDb<S: ScannerFeed>(PhantomData<S>);
-impl<S: ScannerFeed> ReportDb<S> {
+pub(crate) struct BatchDb<S: ScannerFeed>(PhantomData<S>);
+impl<S: ScannerFeed> BatchDb<S> {
   pub(crate) fn set_last_session_to_sign_batch_and_first_batch(
     txn: &mut impl DbTxn,
     session: Session,
@@ -67,14 +60,11 @@ impl<S: ScannerFeed> ReportDb<S> {
     LastSessionToSignBatchAndFirstBatch::get(getter)
   }
 
-  pub(crate) fn set_next_to_potentially_report_block(
-    txn: &mut impl DbTxn,
-    next_to_potentially_report_block: u64,
-  ) {
-    NextToPotentiallyReportBlock::set(txn, &next_to_potentially_report_block);
+  pub(crate) fn set_next_block_to_batch(txn: &mut impl DbTxn, next_block_to_batch: u64) {
+    NextBlockToBatch::set(txn, &next_block_to_batch);
   }
-  pub(crate) fn next_to_potentially_report_block(getter: &impl Get) -> Option<u64> {
-    NextToPotentiallyReportBlock::get(getter)
+  pub(crate) fn next_block_to_batch(getter: &impl Get) -> Option<u64> {
+    NextBlockToBatch::get(getter)
   }
 
   pub(crate) fn acquire_batch_id(txn: &mut impl DbTxn) -> u32 {

processor/scanner/src/batch/mod.rs

@@ -0,0 +1,252 @@
+use core::{marker::PhantomData, future::Future};
+
+use blake2::{digest::typenum::U32, Digest, Blake2b};
+
+use scale::Encode;
+use serai_db::{DbTxn, Db};
+
+use serai_validator_sets_primitives::Session;
+use serai_in_instructions_primitives::{MAX_BATCH_SIZE, Batch};
+
+use primitives::{EncodableG, task::ContinuallyRan};
+use crate::{
+  db::{
+    Returnable, ScannerGlobalDb, InInstructionData, ScanToBatchDb, BatchData, BatchToReportDb,
+    BatchesToSign,
+  },
+  scan::next_to_scan_for_outputs_block,
+  substrate, ScannerFeed, KeyFor,
+};
+
+mod db;
+pub(crate) use db::{BatchInfo, ReturnInformation};
+use db::BatchDb;
+
+pub(crate) fn take_info_for_batch<S: ScannerFeed>(
+  txn: &mut impl DbTxn,
+  id: u32,
+) -> Option<BatchInfo<EncodableG<KeyFor<S>>>> {
+  BatchDb::<S>::take_info_for_batch(txn, id)
+}
+
+pub(crate) fn take_return_information<S: ScannerFeed>(
+  txn: &mut impl DbTxn,
+  id: u32,
+) -> Option<Vec<Option<ReturnInformation<S>>>> {
+  BatchDb::<S>::take_return_information(txn, id)
+}
+
+/*
+  This task produces Batches for notable blocks, with all InInstructions, in an ordered fashion.
+
+  We only produce batches once both tasks, scanning for received outputs and checking for resolved
+  Eventualities, have processed the block. This ensures we know if this block is notable, and have
+  the InInstructions for it.
+*/
+#[allow(non_snake_case)]
+pub(crate) struct BatchTask<D: Db, S: ScannerFeed> {
+  db: D,
+  _S: PhantomData<S>,
+}
+
+impl<D: Db, S: ScannerFeed> BatchTask<D, S> {
+  pub(crate) fn new(mut db: D, start_block: u64) -> Self {
+    if BatchDb::<S>::next_block_to_batch(&db).is_none() {
+      // Initialize the DB
+      let mut txn = db.txn();
+      BatchDb::<S>::set_next_block_to_batch(&mut txn, start_block);
+      txn.commit();
+    }
+
+    Self { db, _S: PhantomData }
+  }
+}
+
+impl<D: Db, S: ScannerFeed> ContinuallyRan for BatchTask<D, S> {
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+    async move {
+      let highest_batchable = {
+        // Fetch the next to scan block
+        let next_to_scan = next_to_scan_for_outputs_block::<S>(&self.db)
+          .expect("BatchTask run before writing the start block");
+        // If we haven't done any work, return
+        if next_to_scan == 0 {
+          return Ok(false);
+        }
+        // The last scanned block is the block prior to this
+        #[allow(clippy::let_and_return)]
+        let last_scanned = next_to_scan - 1;
+        // The last scanned block is the highest batchable block as we only scan blocks within a
+        // window where it's safe to immediately report the block
+        // See `eventuality.rs` for more info
+        last_scanned
+      };
+
+      let next_block_to_batch = BatchDb::<S>::next_block_to_batch(&self.db)
+        .expect("BatchTask run before writing the start block");
+
+      for block_number in next_block_to_batch ..= highest_batchable {
+        let mut txn = self.db.txn();
+
+        // Receive the InInstructions for this block
+        // We always do this as we can't trivially tell if we should recv InInstructions before we
+        // do
+        let InInstructionData {
+          session_to_sign_batch,
+          external_key_for_session_to_sign_batch,
+          returnable_in_instructions: in_instructions,
+        } = ScanToBatchDb::<S>::recv_in_instructions(&mut txn, block_number);
+
+        let notable = ScannerGlobalDb::<S>::is_block_notable(&txn, block_number);
+        if !notable {
+          assert!(in_instructions.is_empty(), "block wasn't notable yet had InInstructions");
+        }
+        // If this block is notable, create the Batch(s) for it
+        if notable {
+          let network = S::NETWORK;
+          let mut batch_id = BatchDb::<S>::acquire_batch_id(&mut txn);
+
+          // start with empty batch
+          let mut batches = vec![Batch { network, id: batch_id, instructions: vec![] }];
+          // We also track the return information for the InInstructions within a Batch in case
+          // they error
+          let mut return_information = vec![vec![]];
+
+          for Returnable { return_address, in_instruction } in in_instructions {
+            let balance = in_instruction.balance;
+
+            let batch = batches.last_mut().unwrap();
+            batch.instructions.push(in_instruction);
+
+            // check if batch is over-size
+            if batch.encode().len() > MAX_BATCH_SIZE {
+              // pop the last instruction so it's back in size
+              let in_instruction = batch.instructions.pop().unwrap();
+
+              // bump the id for the new batch
+              batch_id = BatchDb::<S>::acquire_batch_id(&mut txn);
+
+              // make a new batch with this instruction included
+              batches.push(Batch { network, id: batch_id, instructions: vec![in_instruction] });
+              // Since we're allocating a new batch, allocate a new set of return addresses for it
+              return_information.push(vec![]);
+            }
+
+            // For the set of return addresses for the InInstructions for the batch we just pushed
+            // onto, push this InInstruction's return addresses
+            return_information
+              .last_mut()
+              .unwrap()
+              .push(return_address.map(|address| ReturnInformation { address, balance }));
+          }
+
+          // Now that we've finalized the Batches, save the information for each to the database
+          assert_eq!(batches.len(), return_information.len());
+          for (batch, return_information) in batches.iter().zip(&return_information) {
+            assert_eq!(batch.instructions.len(), return_information.len());
+            BatchDb::<S>::save_batch_info(
+              &mut txn,
+              batch.id,
+              block_number,
+              session_to_sign_batch,
+              external_key_for_session_to_sign_batch,
+              Blake2b::<U32>::digest(batch.instructions.encode()).into(),
+            );
+            BatchDb::<S>::save_return_information(&mut txn, batch.id, return_information);
+          }
+
+          for batch in batches {
+            BatchToReportDb::<S>::send_batch(
+              &mut txn,
+              &BatchData {
+                session_to_sign_batch,
+                external_key_for_session_to_sign_batch: EncodableG(
+                  external_key_for_session_to_sign_batch,
+                ),
+                batch,
+              },
+            );
+          }
+        }
+
+        // Update the next block to batch
+        BatchDb::<S>::set_next_block_to_batch(&mut txn, block_number + 1);
+
+        txn.commit();
+      }
+
+      // TODO: This should be its own task. The above doesn't error, doesn't return early, so this
+      // is fine, but this is precarious and would be better as its own task
+      loop {
+        let mut txn = self.db.txn();
+        let Some(BatchData {
+          session_to_sign_batch,
+          external_key_for_session_to_sign_batch,
+          batch,
+        }) = BatchToReportDb::<S>::try_recv_batch(&mut txn)
+        else {
+          break;
+        };
+
+        /*
+          If this is the handover Batch, the first Batch signed by a session which retires the
+          prior validator set, then this should only be signed after the prior validator set's
+          actions are fully validated.
+
+          The new session will only be responsible for signing this Batch if the prior key has
+          retired, successfully completed all its on-external-network actions.
+
+          We check here the prior session has successfully completed all its on-Serai-network
+          actions by ensuring we've validated all Batches expected from it. Only then do we sign
+          the Batch confirming the handover.
+
+          We also wait for the Batch confirming the handover to be accepted on-chain, ensuring we
+          don't verify the prior session's Batches, sign the handover Batch and the following
+          Batch, have the prior session publish a malicious Batch where our handover Batch should
+          be, before our following Batch becomes our handover Batch.
+        */
+        if session_to_sign_batch != Session(0) {
+          // We may have Session(1)'s first Batch be Batch 0 if Session(0) never publishes a
+          // Batch. This is fine as we'll hit the distinct Session check and then set the correct
+          // values into this DB entry. All other sessions must complete the handover process,
+          // which requires having published at least one Batch
+          let (last_session, first_batch) =
+            BatchDb::<S>::last_session_to_sign_batch_and_first_batch(&txn)
+              .unwrap_or((Session(0), 0));
+          // Because this boolean was expanded, we lose short-circuiting. That's fine
+          let handover_batch = last_session != session_to_sign_batch;
+          let batch_after_handover_batch =
+            (last_session == session_to_sign_batch) && ((first_batch + 1) == batch.id);
+          if handover_batch || batch_after_handover_batch {
+            let verified_prior_batch = substrate::last_acknowledged_batch::<S>(&txn)
+              // Since `batch.id = 0` in the Session(0)-never-published-a-Batch case, we don't
+              // check `last_acknowledged_batch >= (batch.id - 1)` but instead this
+              .map(|last_acknowledged_batch| (last_acknowledged_batch + 1) >= batch.id)
+              // We've never verified any Batches
+              .unwrap_or(false);
+            if !verified_prior_batch {
+              // Drop the txn to restore the Batch to report to the DB
+              drop(txn);
+              break;
+            }
+          }
+
+          // If this is the handover Batch, update the last session to sign a Batch
+          if handover_batch {
+            BatchDb::<S>::set_last_session_to_sign_batch_and_first_batch(
+              &mut txn,
+              session_to_sign_batch,
+              batch.id,
+            );
+          }
+        }
+
+        BatchesToSign::send(&mut txn, &external_key_for_session_to_sign_batch.0, &batch);
+        txn.commit();
+      }
+
+      // Run dependents if were able to batch any blocks
+      Ok(next_block_to_batch <= highest_batchable)
+    }
+  }
+}

processor/scanner/src/db.rs

@@ -482,7 +482,7 @@ struct BlockBoundInInstructions {
 }
 
 db_channel! {
-  ScannerScanReport {
+  ScannerScanBatch {
     InInstructions: () -> BlockBoundInInstructions,
   }
 }
@@ -493,8 +493,8 @@ pub(crate) struct InInstructionData<S: ScannerFeed> {
   pub(crate) returnable_in_instructions: Vec<Returnable<S>>,
 }
 
-pub(crate) struct ScanToReportDb<S: ScannerFeed>(PhantomData<S>);
-impl<S: ScannerFeed> ScanToReportDb<S> {
+pub(crate) struct ScanToBatchDb<S: ScannerFeed>(PhantomData<S>);
+impl<S: ScannerFeed> ScanToBatchDb<S> {
   pub(crate) fn send_in_instructions(
     txn: &mut impl DbTxn,
     block_number: u64,
@@ -545,6 +545,30 @@ impl<S: ScannerFeed> ScanToReportDb<S> {
   }
 }
 
+#[derive(BorshSerialize, BorshDeserialize)]
+pub(crate) struct BatchData<K: BorshSerialize + BorshDeserialize> {
+  pub(crate) session_to_sign_batch: Session,
+  pub(crate) external_key_for_session_to_sign_batch: K,
+  pub(crate) batch: Batch,
+}
+
+db_channel! {
+  ScannerBatchReport {
+    BatchToReport: <K: Borshy>() -> BatchData<K>,
+  }
+}
+
+pub(crate) struct BatchToReportDb<S: ScannerFeed>(PhantomData<S>);
+impl<S: ScannerFeed> BatchToReportDb<S> {
+  pub(crate) fn send_batch(txn: &mut impl DbTxn, batch_data: &BatchData<EncodableG<KeyFor<S>>>) {
+    BatchToReport::send(txn, batch_data);
+  }
+
+  pub(crate) fn try_recv_batch(txn: &mut impl DbTxn) -> Option<BatchData<EncodableG<KeyFor<S>>>> {
+    BatchToReport::try_recv(txn)
+  }
+}
+
 db_channel! {
   ScannerSubstrateEventuality {
     Burns: (acknowledged_block: u64) -> Vec<OutInstructionWithBalance>,
@@ -583,7 +607,6 @@ mod _public_db {
 
   db_channel! {
     ScannerPublic {
-      Batches: () -> Batch,
       BatchesToSign: (key: &[u8]) -> Batch,
       AcknowledgedBatches: (key: &[u8]) -> u32,
       CompletedEventualities: (key: &[u8]) -> [u8; 32],
@@ -591,21 +614,6 @@ mod _public_db {
   }
 }
 
-/// The batches to publish.
-///
-/// This is used for auditing the Batches published to Serai.
-pub struct Batches;
-impl Batches {
-  pub(crate) fn send(txn: &mut impl DbTxn, batch: &Batch) {
-    _public_db::Batches::send(txn, batch);
-  }
-
-  /// Receive a batch to publish.
-  pub fn try_recv(txn: &mut impl DbTxn) -> Option<Batch> {
-    _public_db::Batches::try_recv(txn)
-  }
-}
-
 /// The batches to sign and publish.
 ///
 /// This is used for publishing Batches onto Serai.

processor/scanner/src/lib.rs

@@ -23,13 +23,13 @@ pub use lifetime::LifetimeStage;
 // Database schema definition and associated functions.
 mod db;
 use db::ScannerGlobalDb;
-pub use db::{Batches, BatchesToSign, AcknowledgedBatches, CompletedEventualities};
+pub use db::{BatchesToSign, AcknowledgedBatches, CompletedEventualities};
 // Task to index the blockchain, ensuring we don't reorganize finalized blocks.
 mod index;
 // Scans blocks for received coins.
 mod scan;
-/// Task which reports Batches to Substrate.
-mod report;
+/// Task which creates Batches for Substrate.
+mod batch;
 /// Task which handles events from Substrate once we can.
 mod substrate;
 /// Check blocks for transactions expected to eventually occur.
@@ -379,24 +379,24 @@ impl<S: ScannerFeed> Scanner<S> {
 
     let index_task = index::IndexTask::new(db.clone(), feed.clone(), start_block).await;
     let scan_task = scan::ScanTask::new(db.clone(), feed.clone(), start_block);
-    let report_task = report::ReportTask::<_, S>::new(db.clone(), start_block);
+    let batch_task = batch::BatchTask::<_, S>::new(db.clone(), start_block);
     let substrate_task = substrate::SubstrateTask::<_, S>::new(db.clone());
     let eventuality_task =
       eventuality::EventualityTask::<_, _, _>::new(db, feed, scheduler, start_block);
 
     let (index_task_def, _index_handle) = Task::new();
     let (scan_task_def, scan_handle) = Task::new();
-    let (report_task_def, report_handle) = Task::new();
+    let (batch_task_def, batch_handle) = Task::new();
     let (substrate_task_def, substrate_handle) = Task::new();
     let (eventuality_task_def, eventuality_handle) = Task::new();
 
     // Upon indexing a new block, scan it
     tokio::spawn(index_task.continually_run(index_task_def, vec![scan_handle.clone()]));
-    // Upon scanning a block, report it
-    tokio::spawn(scan_task.continually_run(scan_task_def, vec![report_handle]));
-    // Upon reporting a block, we do nothing (as the burden is on Substrate which won't be
-    // immediately ready)
-    tokio::spawn(report_task.continually_run(report_task_def, vec![]));
+    // Upon scanning a block, creates the batches for it
+    tokio::spawn(scan_task.continually_run(scan_task_def, vec![batch_handle]));
+    // Upon creating batches for a block, we do nothing (as the burden is on Substrate which won't
+    // be immediately ready)
+    tokio::spawn(batch_task.continually_run(batch_task_def, vec![]));
     // Upon handling an event from Substrate, we run the Eventuality task (as it's what's affected)
     tokio::spawn(substrate_task.continually_run(substrate_task_def, vec![eventuality_handle]));
     // Upon handling the Eventualities in a block, we run the scan task as we've advanced the

processor/scanner/src/report/mod.rs

@@ -1,240 +0,0 @@
-use core::{marker::PhantomData, future::Future};
-
-use blake2::{digest::typenum::U32, Digest, Blake2b};
-
-use scale::Encode;
-use serai_db::{DbTxn, Db};
-
-use serai_validator_sets_primitives::Session;
-use serai_in_instructions_primitives::{MAX_BATCH_SIZE, Batch};
-
-use primitives::{EncodableG, task::ContinuallyRan};
-use crate::{
-  db::{Returnable, ScannerGlobalDb, InInstructionData, ScanToReportDb, Batches, BatchesToSign},
-  scan::next_to_scan_for_outputs_block,
-  substrate, ScannerFeed, KeyFor,
-};
-
-mod db;
-pub(crate) use db::{BatchInfo, ReturnInformation, InternalBatches};
-use db::ReportDb;
-
-pub(crate) fn take_info_for_batch<S: ScannerFeed>(
-  txn: &mut impl DbTxn,
-  id: u32,
-) -> Option<BatchInfo<EncodableG<KeyFor<S>>>> {
-  ReportDb::<S>::take_info_for_batch(txn, id)
-}
-
-pub(crate) fn take_return_information<S: ScannerFeed>(
-  txn: &mut impl DbTxn,
-  id: u32,
-) -> Option<Vec<Option<ReturnInformation<S>>>> {
-  ReportDb::<S>::take_return_information(txn, id)
-}
-
-/*
-  This task produces Batches for notable blocks, with all InInstructions, in an ordered fashion.
-
-  We only report blocks once both tasks, scanning for received outputs and checking for resolved
-  Eventualities, have processed the block. This ensures we know if this block is notable, and have
-  the InInstructions for it.
-*/
-#[allow(non_snake_case)]
-pub(crate) struct ReportTask<D: Db, S: ScannerFeed> {
-  db: D,
-  _S: PhantomData<S>,
-}
-
-impl<D: Db, S: ScannerFeed> ReportTask<D, S> {
-  pub(crate) fn new(mut db: D, start_block: u64) -> Self {
-    if ReportDb::<S>::next_to_potentially_report_block(&db).is_none() {
-      // Initialize the DB
-      let mut txn = db.txn();
-      ReportDb::<S>::set_next_to_potentially_report_block(&mut txn, start_block);
-      txn.commit();
-    }
-
-    Self { db, _S: PhantomData }
-  }
-}
-
-impl<D: Db, S: ScannerFeed> ContinuallyRan for ReportTask<D, S> {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
-    async move {
-      let highest_reportable = {
-        // Fetch the next to scan block
-        let next_to_scan = next_to_scan_for_outputs_block::<S>(&self.db)
-          .expect("ReportTask run before writing the start block");
-        // If we haven't done any work, return
-        if next_to_scan == 0 {
-          return Ok(false);
-        }
-        // The last scanned block is the block prior to this
-        #[allow(clippy::let_and_return)]
-        let last_scanned = next_to_scan - 1;
-        // The last scanned block is the highest reportable block as we only scan blocks within a
-        // window where it's safe to immediately report the block
-        // See `eventuality.rs` for more info
-        last_scanned
-      };
-
-      let next_to_potentially_report = ReportDb::<S>::next_to_potentially_report_block(&self.db)
-        .expect("ReportTask run before writing the start block");
-
-      for block_number in next_to_potentially_report ..= highest_reportable {
-        let mut txn = self.db.txn();
-
-        // Receive the InInstructions for this block
-        // We always do this as we can't trivially tell if we should recv InInstructions before we
-        // do
-        let InInstructionData {
-          session_to_sign_batch,
-          external_key_for_session_to_sign_batch,
-          returnable_in_instructions: in_instructions,
-        } = ScanToReportDb::<S>::recv_in_instructions(&mut txn, block_number);
-
-        let notable = ScannerGlobalDb::<S>::is_block_notable(&txn, block_number);
-        if !notable {
-          assert!(in_instructions.is_empty(), "block wasn't notable yet had InInstructions");
-        }
-        // If this block is notable, create the Batch(s) for it
-        if notable {
-          let network = S::NETWORK;
-          let mut batch_id = ReportDb::<S>::acquire_batch_id(&mut txn);
-
-          // start with empty batch
-          let mut batches = vec![Batch { network, id: batch_id, instructions: vec![] }];
-          // We also track the return information for the InInstructions within a Batch in case
-          // they error
-          let mut return_information = vec![vec![]];
-
-          for Returnable { return_address, in_instruction } in in_instructions {
-            let balance = in_instruction.balance;
-
-            let batch = batches.last_mut().unwrap();
-            batch.instructions.push(in_instruction);
-
-            // check if batch is over-size
-            if batch.encode().len() > MAX_BATCH_SIZE {
-              // pop the last instruction so it's back in size
-              let in_instruction = batch.instructions.pop().unwrap();
-
-              // bump the id for the new batch
-              batch_id = ReportDb::<S>::acquire_batch_id(&mut txn);
-
-              // make a new batch with this instruction included
-              batches.push(Batch { network, id: batch_id, instructions: vec![in_instruction] });
-              // Since we're allocating a new batch, allocate a new set of return addresses for it
-              return_information.push(vec![]);
-            }
-
-            // For the set of return addresses for the InInstructions for the batch we just pushed
-            // onto, push this InInstruction's return addresses
-            return_information
-              .last_mut()
-              .unwrap()
-              .push(return_address.map(|address| ReturnInformation { address, balance }));
-          }
-
-          // Now that we've finalized the Batches, save the information for each to the database
-          assert_eq!(batches.len(), return_information.len());
-          for (batch, return_information) in batches.iter().zip(&return_information) {
-            assert_eq!(batch.instructions.len(), return_information.len());
-            ReportDb::<S>::save_batch_info(
-              &mut txn,
-              batch.id,
-              block_number,
-              session_to_sign_batch,
-              external_key_for_session_to_sign_batch,
-              Blake2b::<U32>::digest(batch.instructions.encode()).into(),
-            );
-            ReportDb::<S>::save_return_information(&mut txn, batch.id, return_information);
-          }
-
-          for batch in batches {
-            InternalBatches::send(
-              &mut txn,
-              &(session_to_sign_batch, EncodableG(external_key_for_session_to_sign_batch), batch),
-            );
-          }
-        }
-
-        // Update the next to potentially report block
-        ReportDb::<S>::set_next_to_potentially_report_block(&mut txn, block_number + 1);
-
-        txn.commit();
-      }
-
-      // TODO: This should be its own task. The above doesn't error, doesn't return early, so this
-      // is fine, but this is precarious and would be better as its own task
-      {
-        let mut txn = self.db.txn();
-        while let Some((session_to_sign_batch, external_key_for_session_to_sign_batch, batch)) =
-          InternalBatches::<KeyFor<S>>::peek(&txn)
-        {
-          /*
-            If this is the handover Batch, the first Batch signed by a session which retires the
-            prior validator set, then this should only be signed after the prior validator set's
-            actions are fully validated.
-
-            The new session will only be responsible for signing this Batch if the prior key has
-            retired, successfully completed all its on-external-network actions.
-
-            We check here the prior session has successfully completed all its on-Serai-network
-            actions by ensuring we've validated all Batches expected from it. Only then do we sign
-            the Batch confirming the handover.
-
-            We also wait for the Batch confirming the handover to be accepted on-chain, ensuring we
-            don't verify the prior session's Batches, sign the handover Batch and the following
-            Batch, have the prior session publish a malicious Batch where our handover Batch should
-            be, before our following Batch becomes our handover Batch.
-          */
-          if session_to_sign_batch != Session(0) {
-            // We may have Session(1)'s first Batch be Batch 0 if Session(0) never publishes a
-            // Batch. This is fine as we'll hit the distinct Session check and then set the correct
-            // values into this DB entry. All other sessions must complete the handover process,
-            // which requires having published at least one Batch
-            let (last_session, first_batch) =
-              ReportDb::<S>::last_session_to_sign_batch_and_first_batch(&txn)
-                .unwrap_or((Session(0), 0));
-            // Because this boolean was expanded, we lose short-circuiting. That's fine
-            let handover_batch = last_session != session_to_sign_batch;
-            let batch_after_handover_batch =
-              (last_session == session_to_sign_batch) && ((first_batch + 1) == batch.id);
-            if handover_batch || batch_after_handover_batch {
-              let verified_prior_batch = substrate::last_acknowledged_batch::<S>(&txn)
-                // Since `batch.id = 0` in the Session(0)-never-published-a-Batch case, we don't
-                // check `last_acknowledged_batch >= (batch.id - 1)` but instead this
-                .map(|last_acknowledged_batch| (last_acknowledged_batch + 1) >= batch.id)
-                // We've never verified any Batches
-                .unwrap_or(false);
-              if !verified_prior_batch {
-                break;
-              }
-            }
-
-            // If this is the handover Batch, update the last session to sign a Batch
-            if handover_batch {
-              ReportDb::<S>::set_last_session_to_sign_batch_and_first_batch(
-                &mut txn,
-                session_to_sign_batch,
-                batch.id,
-              );
-            }
-          }
-
-          // Since we should handle this batch now, recv it from the channel
-          InternalBatches::<KeyFor<S>>::try_recv(&mut txn).unwrap();
-
-          Batches::send(&mut txn, &batch);
-          BatchesToSign::send(&mut txn, &external_key_for_session_to_sign_batch.0, &batch);
-        }
-        txn.commit();
-      }
-
-      // Run dependents if we decided to report any blocks
-      Ok(next_to_potentially_report <= highest_reportable)
-    }
-  }
-}

processor/scanner/src/scan/mod.rs

@@ -14,7 +14,7 @@ use crate::{
   lifetime::LifetimeStage,
   db::{
     OutputWithInInstruction, Returnable, SenderScanData, ScannerGlobalDb, InInstructionData,
-    ScanToReportDb, ScanToEventualityDb,
+    ScanToBatchDb, ScanToEventualityDb,
   },
   BlockExt, ScannerFeed, AddressFor, OutputFor, Return, sort_outputs,
   eventuality::latest_scannable_block,
@@ -345,7 +345,7 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for ScanTask<D, S> {
         // We need to also specify which key is responsible for signing the Batch for these, which
         // will always be the oldest key (as the new key signing the Batch signifies handover
         // acceptance)
-        ScanToReportDb::<S>::send_in_instructions(
+        ScanToBatchDb::<S>::send_in_instructions(
           &mut txn,
           b,
           &InInstructionData {

processor/scanner/src/substrate/mod.rs

@@ -8,7 +8,7 @@ use serai_validator_sets_primitives::Session;
 use primitives::task::ContinuallyRan;
 use crate::{
   db::{ScannerGlobalDb, SubstrateToEventualityDb, AcknowledgedBatches},
-  report, ScannerFeed, KeyFor,
+  batch, ScannerFeed, KeyFor,
 };
 
 mod db;
@@ -82,12 +82,12 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for SubstrateTask<D, S> {
             key_to_activate,
           }) => {
             // Check if we have the information for this batch
-            let Some(report::BatchInfo {
+            let Some(batch::BatchInfo {
               block_number,
               session_to_sign_batch,
               external_key_for_session_to_sign_batch,
               in_instructions_hash: expected_in_instructions_hash,
-            }) = report::take_info_for_batch::<S>(&mut txn, batch_id)
+            }) = batch::take_info_for_batch::<S>(&mut txn, batch_id)
             else {
               // If we don't, drop this txn (restoring the action to the database)
               drop(txn);
@@ -143,7 +143,7 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for SubstrateTask<D, S> {
 
             // Return the balances for any InInstructions which failed to execute
             {
-              let return_information = report::take_return_information::<S>(&mut txn, batch_id)
+              let return_information = batch::take_return_information::<S>(&mut txn, batch_id)
                 .expect("didn't save the return information for Batch we published");
               assert_eq!(
               in_instruction_results.len(),
@@ -159,7 +159,7 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for SubstrateTask<D, S> {
                   continue;
                 }
 
-                if let Some(report::ReturnInformation { address, balance }) = return_information {
+                if let Some(batch::ReturnInformation { address, balance }) = return_information {
                   burns.push(OutInstructionWithBalance {
                     instruction: OutInstruction { address: address.into() },
                     balance,

processor/signers/src/coordinator/mod.rs

@@ -136,20 +136,6 @@ impl<D: Db, C: Coordinator> ContinuallyRan for CoordinatorTask<D, C> {
         }
       }
 
-      // Publish the Batches
-      {
-        let mut txn = self.db.txn();
-        while let Some(batch) = scanner::Batches::try_recv(&mut txn) {
-          iterated = true;
-          self
-            .coordinator
-            .publish_batch(batch)
-            .await
-            .map_err(|e| format!("couldn't publish Batch: {e:?}"))?;
-        }
-        txn.commit();
-      }
-
       // Publish the signed Batches
       {
         let mut txn = self.db.txn();

processor/signers/src/lib.rs

@@ -64,12 +64,6 @@ pub trait Coordinator: 'static + Send + Sync {
     signature: Signature,
   ) -> impl Send + Future<Output = Result<(), Self::EphemeralError>>;
 
-  /// Publish a `Batch`.
-  fn publish_batch(
-    &mut self,
-    batch: Batch,
-  ) -> impl Send + Future<Output = Result<(), Self::EphemeralError>>;
-
   /// Publish a `SignedBatch`.
   fn publish_signed_batch(
     &mut self,