dot/state: update rewind to forcefully set blocktree root, update fla…

…g param to be block to rewind to (#1443)

cmd/gossamer/flags.go

@@ -43,10 +43,10 @@ var (
 		Name:  "roles",
 		Usage: "Roles of the gossamer node",
 	}
-	// RewindFlag rewinds the head of the chain by the given number of blocks. Useful for development
+	// RewindFlag rewinds the head of the chain to the given block number. Useful for development
 	RewindFlag = cli.IntFlag{
 		Name:  "rewind",
-		Usage: "Rewind head of chain by given number of blocks",
+		Usage: "Rewind head of chain to the given block number",
 	}
 )
 

dot/services.go

@@ -64,7 +64,7 @@ func createStateService(cfg *Config) (*state.Service, error) {
 	}
 
 	if cfg.State.Rewind != 0 {
-		err = stateSrvc.Rewind(cfg.State.Rewind)
+		err = stateSrvc.Rewind(int64(cfg.State.Rewind))
 		if err != nil {
 			return nil, fmt.Errorf("failed to rewind state: %w", err)
 		}

dot/state/service.go

@@ -19,6 +19,7 @@ package state
 import (
 	"bytes"
 	"fmt"
+	"math/big"
 	"os"
 	"path/filepath"
 
@@ -321,13 +322,22 @@ func (s *Service) Start() error {
 	return nil
 }
 
-// Rewind rewinds the chain by the given number of blocks.
+// Rewind rewinds the chain to the given block number.
 // If the given number of blocks is greater than the chain height, it will rewind to genesis.
-func (s *Service) Rewind(numBlocks int) error {
+func (s *Service) Rewind(toBlock int64) error {
 	num, _ := s.Block.BestBlockNumber()
+	if toBlock > num.Int64() {
+		return fmt.Errorf("cannot rewind, given height is higher than our current height")
+	}
+
+	logger.Info("rewinding state...", "current height", num, "desired height", toBlock)
+
+	root, err := s.Block.GetBlockByNumber(big.NewInt(toBlock))
+	if err != nil {
+		return err
+	}
 
-	logger.Info("rewinding state...", "current height", num, "to rewind", numBlocks)
-	s.Block.bt.Rewind(numBlocks)
+	s.Block.bt = blocktree.NewBlockTreeFromRoot(root.Header, s.db)
 	newHead := s.Block.BestBlockHash()
 
 	header, _ := s.Block.BestBlockHeader()