feat: improve import-history ux

cmd/geth/chaincmd.go

@@ -538,7 +538,7 @@ func importHistory(ctx *cli.Context) error {
 	default:
 		return fmt.Errorf("unknown --era.format %q (expected 'era1' or 'erae')", format)
 	}
-	if err := utils.ImportHistory(chain, dir, network, from); err != nil {
+	if err := utils.ImportHistory(chain, db, dir, network, from); err != nil {
 		return err
 	}
 

cmd/utils/cmd.go

@@ -252,10 +252,7 @@ func readList(filename string) ([]string, error) {
 // ImportHistory imports Era1 files containing historical block information,
 // starting from genesis. The assumption is held that the provided chain
 // segment in Era1 file should all be canonical and verified.
-func ImportHistory(chain *core.BlockChain, dir string, network string, from func(f era.ReadAtSeekCloser) (era.Era, error)) error {
-	if chain.CurrentSnapBlock().Number.BitLen() != 0 {
-		return errors.New("history import only supported when starting from genesis")
-	}
+func ImportHistory(chain *core.BlockChain, db ethdb.Database, dir string, network string, from func(f era.ReadAtSeekCloser) (era.Era, error)) error {
 	entries, err := era.ReadDir(dir, network)
 	if err != nil {
 		return fmt.Errorf("error reading %s: %w", dir, err)
@@ -269,6 +266,13 @@ func ImportHistory(chain *core.BlockChain, dir string, network string, from func
 			len(checksums), len(entries))
 	}
 
+	// Determine resume point from last successfully imported block
+	var resumeBlock uint64
+	if tail := rawdb.ReadEraImportTail(db); tail != nil {
+		resumeBlock = *tail
+		log.Info("Resuming era import", "lastBlock", resumeBlock)
+	}
+
 	var (
 		start    = time.Now()
 		reported = time.Now()
@@ -281,12 +285,29 @@ func ImportHistory(chain *core.BlockChain, dir string, network string, from func
 		err := func() error {
 			path := filepath.Join(dir, file)
 
-			// validate against checksum file in directory
 			f, err := os.Open(path)
 			if err != nil {
 				return fmt.Errorf("open %s: %w", path, err)
 			}
 			defer f.Close()
+
+			// Peek at era block range to see if we can skip entirely
+			e, err := from(f)
+			if err != nil {
+				return fmt.Errorf("error opening era: %w", err)
+			}
+			eraStart := e.Start()
+			eraEnd := eraStart + e.Count() - 1
+
+			// Skip era files fully behind resume point
+			if resumeBlock > 0 && eraEnd <= resumeBlock {
+				log.Debug("Skipping already imported Era file", "file", file, "eraEnd", eraEnd, "resumeBlock", resumeBlock)
+				return nil
+			}
+
+			if _, err := f.Seek(0, io.SeekStart); err != nil {
+				return fmt.Errorf("seek %s: %w", path, err)
+			}
 			if _, err := io.Copy(h, f); err != nil {
 				return fmt.Errorf("checksum %s: %w", path, err)
 			}
@@ -294,12 +315,13 @@ func ImportHistory(chain *core.BlockChain, dir string, network string, from func
 			want := checksums[i]
 			h.Reset()
 			scratch.Reset()
-
 			if got != want {
 				return fmt.Errorf("%s checksum mismatch: have %s want %s", file, got, want)
 			}
-			// Import all block data from Era1.
-			e, err := from(f)
+			if _, err := f.Seek(0, io.SeekStart); err != nil {
+				return fmt.Errorf("seek %s: %w", path, err)
+			}
+			e, err = from(f)
 			if err != nil {
 				return fmt.Errorf("error opening era: %w", err)
 			}
@@ -316,6 +338,10 @@ func ImportHistory(chain *core.BlockChain, dir string, network string, from func
 				if block.Number().BitLen() == 0 {
 					continue // skip genesis
 				}
+				// Skip blocks already imported (mid-epoch resume)
+				if resumeBlock > 0 && block.Number().Uint64() <= resumeBlock {
+					continue
+				}
 				receipts, err := it.Receipts()
 				if err != nil {
 					return fmt.Errorf("error reading receipts %d: %w", it.Number(), err)
@@ -324,6 +350,8 @@ func ImportHistory(chain *core.BlockChain, dir string, network string, from func
 				if _, err := chain.InsertReceiptChain([]*types.Block{block}, enc, math.MaxUint64); err != nil {
 					return fmt.Errorf("error inserting body %d: %w", it.Number(), err)
 				}
+				rawdb.WriteEraImportTail(db, block.Number().Uint64())
+				resumeBlock = block.Number().Uint64()
 				imported++
 
 				if time.Since(reported) >= 8*time.Second {

cmd/utils/history_test.go

@@ -182,7 +182,7 @@ func TestHistoryImportAndExport(t *testing.T) {
 			if err != nil {
 				t.Fatalf("unable to initialize chain: %v", err)
 			}
-			if err := ImportHistory(imported, dir, "mainnet", tt.from); err != nil {
+			if err := ImportHistory(imported, db2, dir, "mainnet", tt.from); err != nil {
 				t.Fatalf("failed to import chain: %v", err)
 			}
 			if have, want := imported.CurrentHeader(), chain.CurrentHeader(); have.Hash() != want.Hash() {

core/rawdb/accessors_indexes.go

@@ -32,6 +32,21 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
+func ReadEraImportTail(db ethdb.KeyValueReader) *uint64 {
+	data, _ := db.Get(eraImportTailKey)
+	if len(data) == 0 {
+		return nil
+	}
+	tail := binary.BigEndian.Uint64(data)
+	return &tail
+}
+
+func WriteEraImportTail(db ethdb.KeyValueWriter, blockNumber uint64) {
+	buf := make([]byte, 8)
+	binary.BigEndian.PutUint64(buf, blockNumber)
+	db.Put(eraImportTailKey, buf)
+}
+
 // DecodeTxLookupEntry decodes the supplied tx lookup data.
 func DecodeTxLookupEntry(data []byte, db ethdb.Reader) *uint64 {
 	// Database v6 tx lookup just stores the block number

core/rawdb/schema.go

@@ -87,6 +87,8 @@ var (
 	// txIndexTailKey tracks the oldest block whose transactions have been indexed.
 	txIndexTailKey = []byte("TransactionIndexTail")
 
+	eraImportTailKey = []byte("eraImportTail") // eraImportTailKey -> last fully imported block
+
 	// fastTxLookupLimitKey tracks the transaction lookup limit during fast sync.
 	// This flag is deprecated, it's kept to avoid reporting errors when inspect
 	// database.