From d71f4e2eb4af45a2d676f799079e7a14503b4604 Mon Sep 17 00:00:00 2001
From: Michael Tsitrin <114929630+mtsitrin@users.noreply.github.com>
Date: Fri, 19 Apr 2024 14:38:57 +0300
Subject: [PATCH] fix(manager): re-use submitted DA batches on SL failure
 (#708)

---
 block/manager.go | 10 ++++++--
 block/submit.go  | 59 +++++++++++++++++++++++++++++++++++++++---------
 block/types.go   | 10 ++++++++
 3 files changed, 66 insertions(+), 13 deletions(-)

diff --git a/block/manager.go b/block/manager.go
index 8dada30b9..f30de5925 100644
--- a/block/manager.go
+++ b/block/manager.go
@@ -60,11 +60,17 @@ type Manager struct {
 	// Block production
 	shouldProduceBlocksCh chan bool
 	produceEmptyBlockCh   chan bool
-	lastSubmissionTime    atomic.Int64
-	batchInProcess        sync.Mutex
 	produceBlockMutex     sync.Mutex
 	applyCachedBlockMutex sync.Mutex
 
+	// batch submission
+	batchInProcess     sync.Mutex
+	lastSubmissionTime atomic.Int64
+	// pendingBatch is the result of the last DA submission
+	// that is pending settlement layer submission.
+	// It is used to avoid double submission of the same batch.
+	pendingBatch *PendingBatch
+
 	// Logging
 	logger types.Logger
 
diff --git a/block/submit.go b/block/submit.go
index dce22d41b..4ac1741c1 100644
--- a/block/submit.go
+++ b/block/submit.go
@@ -49,9 +49,30 @@ func (m *Manager) handleSubmissionTrigger(ctx context.Context) {
 		m.logger.Error("produce empty block", "error", err)
 	}
 
-	syncHeight, err := m.submitNextBatch()
+	if m.pendingBatch != nil {
+		m.logger.Info("pending batch exists", "startHeight", m.pendingBatch.batch.StartHeight, "endHeight", m.pendingBatch.batch.EndHeight)
+	} else {
+		nextBatch, err := m.createNextBatch()
+		if err != nil {
+			m.logger.Error("get next batch", "error", err)
+			return
+		}
+
+		resultSubmitToDA, err := m.submitNextBatchToDA(nextBatch)
+		if err != nil {
+			m.logger.Error("submit next batch", "error", err)
+			return
+		}
+
+		m.pendingBatch = &PendingBatch{
+			daResult: resultSubmitToDA,
+			batch:    nextBatch,
+		}
+	}
+
+	syncHeight, err := m.submitPendingBatchToSL()
 	if err != nil {
-		m.logger.Error("submit next batch", "error", err)
+		m.logger.Error("submit next batch to SL", "error", err)
 		return
 	}
 
@@ -59,27 +80,31 @@ func (m *Manager) handleSubmissionTrigger(ctx context.Context) {
 	m.updateSyncParams(syncHeight)
 }
 
-func (m *Manager) submitNextBatch() (uint64, error) {
-	// Get the batch start and end height
+func (m *Manager) createNextBatch() (*types.Batch, error) {
+	// Create the batch
 	startHeight := m.syncTarget.Load() + 1
 	endHeight := m.store.Height()
-
-	// Create the batch
 	nextBatch, err := m.createNextDABatch(startHeight, endHeight)
 	if err != nil {
 		m.logger.Error("create next batch", "startHeight", startHeight, "endHeight", endHeight, "error", err)
-		return 0, err
+		return nil, err
 	}
 
 	if err := m.validateBatch(nextBatch); err != nil {
-		return 0, err
+		return nil, err
 	}
+
+	return nextBatch, nil
+}
+
+func (m *Manager) submitNextBatchToDA(nextBatch *types.Batch) (*da.ResultSubmitBatch, error) {
+	startHeight := nextBatch.StartHeight
 	actualEndHeight := nextBatch.EndHeight
 
 	isLastBlockEmpty, err := m.isBlockEmpty(actualEndHeight)
 	if err != nil {
 		m.logger.Error("validate last block in batch is empty", "startHeight", startHeight, "endHeight", actualEndHeight, "error", err)
-		return 0, err
+		return nil, err
 	}
 	// Verify the last block in the batch is an empty block and that no ibc messages has accidentially passed through.
 	// This block may not be empty if another block has passed it in line. If that's the case our empty block request will
@@ -94,16 +119,28 @@ func (m *Manager) submitNextBatch() (uint64, error) {
 	resultSubmitToDA := m.dalc.SubmitBatch(nextBatch)
 	if resultSubmitToDA.Code != da.StatusSuccess {
 		err = fmt.Errorf("submit next batch to DA Layer: %s", resultSubmitToDA.Message)
-		return 0, err
+		return nil, err
+	}
+	return &resultSubmitToDA, nil
+}
+
+func (m *Manager) submitPendingBatchToSL() (uint64, error) {
+	if m.pendingBatch == nil {
+		return 0, fmt.Errorf("no pending batch to submit")
 	}
 
 	// Submit batch to SL
-	err = m.settlementClient.SubmitBatch(nextBatch, m.dalc.GetClientType(), &resultSubmitToDA)
+	startHeight := m.pendingBatch.batch.StartHeight
+	actualEndHeight := m.pendingBatch.batch.EndHeight
+	err := m.settlementClient.SubmitBatch(m.pendingBatch.batch, m.dalc.GetClientType(), m.pendingBatch.daResult)
 	if err != nil {
 		m.logger.Error("submit batch to SL", "startHeight", startHeight, "endHeight", actualEndHeight, "error", err)
 		return 0, err
 	}
 
+	// Clear pending batch
+	m.pendingBatch = nil
+
 	return actualEndHeight, nil
 }
 
diff --git a/block/types.go b/block/types.go
index b2519c183..22573d46a 100644
--- a/block/types.go
+++ b/block/types.go
@@ -1,5 +1,10 @@
 package block
 
+import (
+	"github.com/dymensionxyz/dymint/da"
+	"github.com/dymensionxyz/dymint/types"
+)
+
 // TODO: move to types package
 type blockSource string
 
@@ -13,3 +18,8 @@ type blockMetaData struct {
 	source   blockSource
 	daHeight uint64
 }
+
+type PendingBatch struct {
+	daResult *da.ResultSubmitBatch
+	batch    *types.Batch
+}