Merge pull request #77 from EspressoSystems/ma/fix-preconf-hotshot-ge…

…nesis

Preconfirmations: skip pre-rollup hotshot blocks

etherman/etherman.go

@@ -498,20 +498,22 @@ func (etherMan *Client) getMaxPreconfirmation() (uint64, error) {
 	return blockHeight, nil
 }
 
-func (etherMan *Client) GetPreconfirmations(ctx context.Context, fromL2Block uint64) ([]Block, map[common.Hash][]Order, error) {
-	l2BlockHeight, err := etherMan.getMaxPreconfirmation()
+func (etherMan *Client) GetPreconfirmations(ctx context.Context, fromL2Batch uint64) ([]Block, map[common.Hash][]Order, error) {
+	hotShotBlockHeight, err := etherMan.getMaxPreconfirmation()
 	if err != nil {
 		return nil, nil, err
 	}
 
 	var blocks []Block
 	order := make(map[common.Hash][]Order)
 
-	log.Infof("Getting L2 blocks in range ", fromL2Block, "-", l2BlockHeight)
-	for l2BlockNum := fromL2Block; l2BlockNum < l2BlockHeight; l2BlockNum++ {
+	fromHotShotBlock := fromL2Batch + etherMan.cfg.GenesisHotShotBlockNumber
+	log.Infof("Getting HotShot blocks in range %d - %d", fromHotShotBlock, hotShotBlockHeight)
+	for hotShotBlockNum := fromHotShotBlock; hotShotBlockNum < hotShotBlockHeight; hotShotBlockNum++ {
 		var batch SequencedBatch
 		var l1BlockNum uint64
-		err = etherMan.fetchL2Block(ctx, l2BlockNum, &batch, &l1BlockNum)
+
+		err = etherMan.fetchL2Block(ctx, hotShotBlockNum, &batch, &l1BlockNum)
 		if err != nil {
 			return nil, nil, err
 		}

synchronizer/synchronizer.go

@@ -276,16 +276,15 @@ func (s *ClientSynchronizer) syncBlocks(lastEthBlockSynced *state.Block) (*state
 func (s *ClientSynchronizer) syncPreconfirmations() error {
 	for {
 		// Figure out where to start from: what is the first L2 block we haven't synchronized yet?
-		// This is the same as the last synchronized batch number, since L2 block numbers and batch
-		// numbers are offset by 1.
+		// This is the first batch after the last synchronized batch number.
 		latestSyncedBatch, err := s.state.GetLastBatchNumber(s.ctx, nil)
 		if err != nil {
 			log.Warn("error getting latest batch synced. Error: ", err)
 			return err
 		}
 
 		// Fetch new preconfirmed blocks from the sequencer.
-		blocks, order, err := s.etherMan.GetPreconfirmations(s.ctx, latestSyncedBatch)
+		blocks, order, err := s.etherMan.GetPreconfirmations(s.ctx, latestSyncedBatch+1)
 		if err != nil {
 			log.Warn("error getting preconfirmations. Error: ", err)
 			return err