Merge pull request #135 from hermeznetwork/feature/synchronizer-sc

Smart Contracts Data Synchronization

db/historydb/historydb.go

@@ -14,6 +14,8 @@ import (
 	"github.com/russross/meddler"
 )
 
+// TODO(Edu): Document here how HistoryDB is kept consistent
+
 // HistoryDB persist the historic of the rollup
 type HistoryDB struct {
 	db *sqlx.DB
@@ -127,10 +129,11 @@ func (hdb *HistoryDB) GetLastBatchNum() (common.BatchNum, error) {
 	return batchNum, row.Scan(&batchNum)
 }
 
-// GetLastL1TxsNum returns the greatest ForgeL1TxsNum in the DB
-func (hdb *HistoryDB) GetLastL1TxsNum() (uint32, error) {
+// GetLastL1TxsNum returns the greatest ForgeL1TxsNum in the DB.  If there's no
+// batch in the DB (nil, nil) is returned.
+func (hdb *HistoryDB) GetLastL1TxsNum() (*int64, error) {
 	row := hdb.db.QueryRow("SELECT MAX(forge_l1_txs_num) FROM batch;")
-	var lastL1TxsNum uint32
+	lastL1TxsNum := new(int64)
 	return lastL1TxsNum, row.Scan(&lastL1TxsNum)
 }
 

db/historydb/historydb_test.go

@@ -89,8 +89,12 @@ func TestBatches(t *testing.T) {
 	// Generate fake batches
 	const nBatches = 9
 	batches := test.GenBatches(nBatches, blocks)
+	// Test GetLastL1TxsNum with no batches
+	fetchedLastL1TxsNum, err := historyDB.GetLastL1TxsNum()
+	assert.NoError(t, err)
+	assert.Nil(t, fetchedLastL1TxsNum)
 	// Add batches to the DB
-	err := historyDB.AddBatches(batches)
+	err = historyDB.AddBatches(batches)
 	assert.NoError(t, err)
 	// Get batches from the DB
 	fetchedBatches, err := historyDB.GetBatches(0, common.BatchNum(nBatches))
@@ -103,9 +107,9 @@ func TestBatches(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, batches[len(batches)-1].BatchNum, fetchedLastBatchNum)
 	// Test GetLastL1TxsNum
-	fetchedLastL1TxsNum, err := historyDB.GetLastL1TxsNum()
+	fetchedLastL1TxsNum, err = historyDB.GetLastL1TxsNum()
 	assert.NoError(t, err)
-	assert.Equal(t, batches[nBatches-1].ForgeL1TxsNum, fetchedLastL1TxsNum)
+	assert.Equal(t, batches[nBatches-1].ForgeL1TxsNum, *fetchedLastL1TxsNum)
 }
 
 func TestBids(t *testing.T) {

db/l2db/l2db.go

@@ -16,6 +16,8 @@ import (
 	"github.com/russross/meddler"
 )
 
+// TODO(Edu): Check DB consistency while there's concurrent use from Coordinator/TxSelector & API
+
 // L2DB stores L2 txs and authorization registers received by the coordinator and keeps them until they are no longer relevant
 // due to them being forged or invalid after a safety period
 type L2DB struct {

db/statedb/statedb.go

@@ -13,6 +13,8 @@ import (
 	"github.com/iden3/go-merkletree/db/pebble"
 )
 
+// TODO(Edu): Document here how StateDB is kept consistent
+
 // ErrStateDBWithoutMT is used when a method that requires a MerkleTree is
 // called in a StateDB that does not have a MerkleTree defined
 var ErrStateDBWithoutMT = errors.New("Can not call method to use MerkleTree in a StateDB without MerkleTree")