Export EVM history

cmd/lachesis/chaincmd.go

@@ -77,6 +77,20 @@ be gzipped
     lachesis export state
 
 Exports blockchain state into a file.
+`,
+			},
+			{
+				Name:      "evm",
+				Usage:     "Export EVM storage",
+				ArgsUsage: "<filename>",
+				Action:    utils.MigrateFlags(exportEvmStorage),
+				Flags: []cli.Flag{
+					DataDirFlag,
+				},
+				Description: `
+    lachesis export evm
+
+Exports EVM storage into a file.
 `,
 			},
 		},

cmd/lachesis/export_evm_history.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"compress/gzip"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/Fantom-foundation/lachesis-base/common/bigendian"
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"gopkg.in/urfave/cli.v1"
+)
+
+func WriteDB(writer io.Writer, db ethdb.Iteratee) error {
+	it := db.NewIterator(nil, nil)
+	defer it.Release()
+	for it.Next() {
+		_, err := writer.Write(bigendian.Uint32ToBytes(uint32(len(it.Key()))))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(it.Key())
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(bigendian.Uint32ToBytes(uint32(len(it.Value()))))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(it.Value())
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func exportEvmStorage(ctx *cli.Context) error {
+	if len(ctx.Args()) != 1 {
+		utils.Fatalf("This command requires one argument.")
+	}
+
+	cfg := makeAllConfigs(ctx)
+
+	gdb, _ := makeStores(cfg.Node.DataDir, &cfg.Lachesis)
+	defer gdb.Close()
+
+	fn := ctx.Args().First()
+
+	// Open the file handle and potentially wrap with a gzip stream
+	fh, err := os.OpenFile(fn, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+	defer fh.Close()
+
+	var writer io.Writer = fh
+	if strings.HasSuffix(fn, ".gz") {
+		writer = gzip.NewWriter(writer)
+		defer writer.(*gzip.Writer).Close()
+	}
+
+	log.Info("Exporting EVM storage to file", "file", fn)
+	defer log.Info("Exported EVM storage to file", "file", fn)
+
+	return WriteDB(writer, gdb.App().EvmTable())
+}