Make state recover from empty if the recovery height is lower than th…

…e current state height (#513)

blockchain/blockchain.go

@@ -9,6 +9,7 @@ package blockchain
 import (
 	"context"
 	"math/big"
+	"os"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -961,13 +962,26 @@ func (bc *blockchain) startExistingBlockchain(recoveryHeight uint64) error {
 		}
 		startHeight = 1
 	}
-	if recoveryHeight > 0 && startHeight <= recoveryHeight {
+	if recoveryHeight > 0 {
 		for bc.tipHeight > recoveryHeight {
 			if err := bc.dao.deleteTipBlock(); err != nil {
 				return err
 			}
 			bc.tipHeight--
 		}
+		if startHeight > bc.tipHeight {
+			startHeight = 0
+			// Delete existing state DB and reinitialize it
+			if err := os.Remove(bc.config.Chain.TrieDBPath); err != nil {
+				return errors.Wrap(err, "failed to delete existing state DB")
+			}
+			if err := DefaultStateFactoryOption()(bc, bc.config); err != nil {
+				return errors.Wrap(err, "failed to reinitialize state DB")
+			}
+			if err := bc.sf.Start(context.Background()); err != nil {
+				return errors.Wrap(err, "failed to start state factory")
+			}
+		}
 	}
 	for i := startHeight; i <= bc.tipHeight; i++ {
 		blk, err := bc.getBlockByHeight(i)

blockchain/blockchain_test.go

@@ -1098,7 +1098,7 @@ func TestStartExistingBlockchain(t *testing.T) {
 	}()
 
 	require.NoError(addTestingTsfBlocks(bc))
-	require.True(5 == bc.TipHeight())
+	require.Equal(uint64(5), bc.TipHeight())
 
 	// delete state db and recover to tip
 	testutil.CleanupPath(t, testTriePath)
@@ -1114,7 +1114,7 @@ func TestStartExistingBlockchain(t *testing.T) {
 	height, _ := chain.sf.Height()
 	require.Equal(bc.TipHeight(), height)
 
-	// recover to height 3
+	// recover to height 3 from empty state DB
 	testutil.CleanupPath(t, testTriePath)
 	sf, err = factory.NewFactory(cfg, factory.DefaultTrieOption())
 	require.NoError(err)
@@ -1125,7 +1125,13 @@ func TestStartExistingBlockchain(t *testing.T) {
 	require.NoError(chain.startExistingBlockchain(3))
 	height, _ = chain.sf.Height()
 	require.Equal(bc.TipHeight(), height)
-	require.True(3 == height)
+	require.Equal(uint64(3), height)
+
+	// recover to height 2 from an existing state DB with Height 3
+	require.NoError(chain.startExistingBlockchain(2))
+	height, _ = chain.sf.Height()
+	require.Equal(bc.TipHeight(), height)
+	require.Equal(uint64(2), height)
 }
 
 func addCreatorToFactory(sf factory.Factory) error {

server/main.go

@@ -25,6 +25,7 @@ import (
 	_ "go.uber.org/automaxprocs"
 	"go.uber.org/zap"
 
+	"github.com/iotexproject/iotex-core/blockchain"
 	"github.com/iotexproject/iotex-core/config"
 	"github.com/iotexproject/iotex-core/pkg/log"
 	"github.com/iotexproject/iotex-core/pkg/probe"
@@ -50,6 +51,7 @@ func main() {
 	signal.Notify(stop, os.Interrupt)
 	signal.Notify(stop, syscall.SIGTERM)
 	ctx, cancel := context.WithCancel(context.Background())
+	ctxWithValue := context.WithValue(ctx, blockchain.RecoveryHeightKey, uint64(recoveryHeight))
 	stopped := make(chan struct{})
 	livenessCtx, livenessCancel := context.WithCancel(context.Background())
 
@@ -93,7 +95,7 @@ func main() {
 		}
 	}
 
-	itx.StartServer(ctx, svr, probeSvr, cfg)
+	itx.StartServer(ctxWithValue, svr, probeSvr, cfg)
 	close(stopped)
 	<-livenessCtx.Done()
 }