feat: improve block parsing starting height calculations

CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+### Changes
+#### Blocks
+- ([\#72](https://github.com/forbole/juno/pull/72)) Updated missing blocks parsing 
+
+
 ## v3.3.0
 ### Changes
 - ([\#67](https://github.com/forbole/juno/pull/67)) Added support for concurrent transaction handling

cmd/parse/blocks/blocks.go

@@ -44,8 +44,18 @@ will be replaced with the data downloaded from the node.
 			end, _ := cmd.Flags().GetInt64(flagEnd)
 			force, _ := cmd.Flags().GetBool(flagForce)
 
+			lastBlockHeight, err := parseCtx.Database.GetLastBlockHeight()
+			if err != nil {
+				return err
+			}
+
 			// Get the start height, default to the config's height; use flagStart if set
 			startHeight := config.Cfg.Parser.StartHeight
+
+			if lastBlockHeight > startHeight {
+				startHeight = lastBlockHeight
+			}
+
 			if start > 0 {
 				startHeight = start
 			}

cmd/start/cmd.go

@@ -130,6 +130,28 @@ func enqueueMissingBlocks(exportQueue types.HeightQueue, ctx *parser.Context) {
 		panic(fmt.Errorf("failed to get last block from RPCConfig client: %s", err))
 	}
 
+	lastBlockHeightInDB, err := ctx.Database.GetLastBlockHeight()
+	if err != nil {
+		fmt.Errorf("failed to get last block height from database: %s", err)
+	}
+
+	// Get the start height, default to the config's height
+	startHeight := cfg.StartHeight
+
+	// Set startHeight to the latest height in database
+	// if is not set inside config.yaml file,
+	if startHeight == 0 {
+		if lastBlockHeightInDB > 0 {
+			startHeight = lastBlockHeightInDB
+		} else {
+			startHeight = 1
+		}
+	}
+
+	if lastBlockHeightInDB > startHeight {
+		startHeight = lastBlockHeightInDB
+	}
+
 	if cfg.FastSync {
 		ctx.Logger.Info("fast sync is enabled, ignoring all previous blocks", "latest_block_height", latestBlockHeight)
 		for _, module := range ctx.Modules {
@@ -146,7 +168,7 @@ func enqueueMissingBlocks(exportQueue types.HeightQueue, ctx *parser.Context) {
 		}
 	} else {
 		ctx.Logger.Info("syncing missing blocks...", "latest_block_height", latestBlockHeight)
-		for i := cfg.StartHeight; i <= latestBlockHeight; i++ {
+		for i := startHeight; i <= latestBlockHeight; i++ {
 			ctx.Logger.Debug("enqueueing missing block", "height", i)
 			exportQueue <- i
 		}

database/database.go

@@ -16,6 +16,10 @@ type Database interface {
 	// An error is returned if the operation fails.
 	HasBlock(height int64) (bool, error)
 
+	// GetLastBlockHeight returns the last block height stored in database..
+	// An error is returned if the operation fails.
+	GetLastBlockHeight() (int64, error)
+
 	// SaveBlock will be called when a new block is parsed, passing the block itself
 	// and the transactions contained inside that block.
 	// An error is returned if the operation fails.

database/postgresql/postgresql.go

@@ -96,6 +96,22 @@ func (db *Database) HasBlock(height int64) (bool, error) {
 	return res, err
 }
 
+// GetLastBlockHeight returns the last block height stored inside the database
+func (db *Database) GetLastBlockHeight() (int64, error) {
+	stmt := `SELECT height FROM block ORDER BY height DESC LIMIT 1;`
+
+	var height int64
+	if err := db.Sql.QueryRow(stmt).Scan(&height); err != nil {
+		return 0, fmt.Errorf("error while getting last block height, error: %s", err)
+	}
+
+	if height == 0 {
+		return 0, fmt.Errorf("cannot get block height, no blocks saved")
+	}
+
+	return height, nil
+}
+
 // SaveBlock implements database.Database
 func (db *Database) SaveBlock(block *types.Block) error {
 	sqlStatement := `