all cmd changes to pass in functions in chaincmd

cmd/era/main.go

@@ -170,14 +170,15 @@ func open(ctx *cli.Context, epoch uint64) (*onedb.Era, error) {
 		dir     = ctx.String(dirFlag.Name)
 		network = ctx.String(networkFlag.Name)
 	)
-	entries, err := onedb.ReadDir(dir, network)
+	entries, err := era.ReadDir(dir, network)
 	if err != nil {
 		return nil, fmt.Errorf("error reading era dir: %w", err)
 	}
 	if epoch >= uint64(len(entries)) {
 		return nil, fmt.Errorf("epoch out-of-bounds: last %d, want %d", len(entries)-1, epoch)
 	}
-	return onedb.Open(filepath.Join(dir, entries[epoch]))
+	era, err := onedb.Open(filepath.Join(dir, entries[epoch]))
+	return era.(*onedb.Era), err
 }
 
 // verify checks each era1 file in a directory to ensure it is well-formed and
@@ -199,7 +200,7 @@ func verify(ctx *cli.Context) error {
 		reported = time.Now()
 	)
 
-	entries, err := onedb.ReadDir(dir, network)
+	entries, err := era.ReadDir(dir, network)
 	if err != nil {
 		return fmt.Errorf("error reading %s: %w", dir, err)
 	}
@@ -214,18 +215,19 @@ func verify(ctx *cli.Context) error {
 		err := func() error {
 			name := entries[i]
 			e, err := onedb.Open(filepath.Join(dir, name))
+			eraPointer := e.(*onedb.Era)
 			if err != nil {
 				return fmt.Errorf("error opening era1 file %s: %w", name, err)
 			}
 			defer e.Close()
 			// Read accumulator and check against expected.
-			if got, err := e.Accumulator(); err != nil {
+			if got, err := eraPointer.Accumulator(); err != nil {
 				return fmt.Errorf("error retrieving accumulator for %s: %w", name, err)
 			} else if got != want {
 				return fmt.Errorf("invalid root %s: got %s, want %s", name, got, want)
 			}
 			// Recompute accumulator.
-			if err := checkAccumulator(e); err != nil {
+			if err := checkAccumulator(eraPointer); err != nil {
 				return fmt.Errorf("error verify era1 file %s: %w", name, err)
 			}
 			// Give the user some feedback that something is happening.

cmd/geth/chaincmd.go

@@ -43,6 +43,8 @@ import (
 	"github.com/ethereum/go-ethereum/internal/debug"
 	"github.com/ethereum/go-ethereum/internal/era"
 	"github.com/ethereum/go-ethereum/internal/era/eradl"
+	"github.com/ethereum/go-ethereum/internal/era/execdb"
+	"github.com/ethereum/go-ethereum/internal/era/onedb"
 	"github.com/ethereum/go-ethereum/internal/flags"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/node"
@@ -518,11 +520,11 @@ func importHistory(ctx *cli.Context) error {
 	format := ctx.String(utils.EraFormatFlag.Name)
 	switch format {
 	case "era1", "era":
-		if err := utils.ImportHistory(chain, dir, network, utils.Era1); err != nil {
+		if err := utils.ImportHistory(chain, dir, network, onedb.From, onedb.NewIterator); err != nil {
 			return err
 		}
 	case "erae":
-		if err := utils.ImportHistory(chain, dir, network, utils.EraE); err != nil {
+		if err := utils.ImportHistory(chain, dir, network, execdb.From, execdb.NewIterator); err != nil {
 			return err
 		}
 	default:
@@ -563,11 +565,11 @@ func exportHistory(ctx *cli.Context) error {
 	format := ctx.String(utils.EraFormatFlag.Get(ctx))
 	switch format {
 	case "era1", "era":
-		if err := utils.ExportHistory(chain, dir, uint64(first), uint64(last), uint64(era.MaxEra1Size), utils.Era1); err != nil {
+		if err := utils.ExportHistory(chain, dir, uint64(first), uint64(last), uint64(era.MaxSize), onedb.NewBuilder, onedb.Filename); err != nil {
 			utils.Fatalf("Export error: %v\n", err)
 		}
 	case "erae":
-		if err := utils.ExportHistory(chain, dir, uint64(first), uint64(last), uint64(era2.MaxEraESize), utils.EraE); err != nil {
+		if err := utils.ExportHistory(chain, dir, uint64(first), uint64(last), uint64(era.MaxSize), execdb.NewBuilder, execdb.Filename); err != nil {
 			utils.Fatalf("Export error: %v\n", err)
 		}
 	default:

cmd/utils/cmd.go

@@ -44,7 +44,7 @@ import (
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/internal/debug"
-	era2 "github.com/ethereum/go-ethereum/internal/era/execdb"
+	"github.com/ethereum/go-ethereum/internal/era"
 	"github.com/ethereum/go-ethereum/internal/era/onedb"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/node"
@@ -253,11 +253,11 @@ 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) error {
+func ImportHistory(chain *core.BlockChain, dir string, network string, from era.FromFn, iterator era.NewIteratorFn) error {
 	if chain.CurrentSnapBlock().Number.BitLen() != 0 {
 		return errors.New("history import only supported when starting from genesis")
 	}
-	entries, err := onedb.ReadDir(dir, network)
+	entries, err := era.ReadDir(dir, network)
 	if err != nil {
 		return fmt.Errorf("error reading %s: %w", dir, err)
 	}
@@ -301,11 +301,11 @@ func ImportHistory(chain *core.BlockChain, dir string, network string) error {
 				return fmt.Errorf("%s checksum mismatch: have %s want %s", file, got, want)
 			}
 			// Import all block data from Era1.
-			e, err := onedb.From(f)
+			e, err := from(f)
 			if err != nil {
 				return fmt.Errorf("error opening era: %w", err)
 			}
-			it, err := onedb.NewIterator(e)
+			it, err := iterator(e)
 			if err != nil {
 				return fmt.Errorf("error creating iterator: %w", err)
 			}
@@ -347,105 +347,6 @@ func ImportHistory(chain *core.BlockChain, dir string, network string) error {
 	return nil
 }
 
-// ImportHistoryEraE imports Era-E files containing historical block information,
-// starting from genesis. Currently this function follows the assumptions that the provided chain
-// segment in Era-E file should all be canonical and verified. In the future, this function will be
-// extended to support importing Era-E files with proof verification.
-func ImportHistoryEraE(chain *core.BlockChain, dir, network string) error {
-	if chain.CurrentSnapBlock().Number.Sign() != 0 {
-		return errors.New("history import only supported when starting from genesis")
-	}
-
-	entries, err := era2.ReadDir(dir, network)
-	if err != nil {
-		return fmt.Errorf("reading %q: %w", dir, err)
-	}
-	checksums, err := readList(filepath.Join(dir, "checksums.txt"))
-	if err != nil {
-		return fmt.Errorf("reading checksums.txt: %w", err)
-	}
-	if len(entries) != len(checksums) {
-		return fmt.Errorf("mismatch: %d erae files, %d checksums", len(entries), len(checksums))
-	}
-
-	var (
-		start    = time.Now()
-		reported = time.Now()
-		imported int
-		h        = sha256.New()
-		scratch  bytes.Buffer
-	)
-
-	for i, file := range entries {
-		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)
-		}
-		if _, err := io.Copy(h, f); err != nil {
-			f.Close()
-			return fmt.Errorf("checksum %s: %w", path, err)
-		}
-		got := common.BytesToHash(h.Sum(scratch.Bytes()[:])).Hex()
-		want := checksums[i]
-		h.Reset()
-		scratch.Reset()
-		if got != want {
-			f.Close()
-			return fmt.Errorf("%s checksum mismatch: have %s want %s", file, got, want)
-		}
-		// rewind for reading
-		if _, err := f.Seek(0, io.SeekStart); err != nil {
-			f.Close()
-			return fmt.Errorf("rewind %s: %w", file, err)
-		}
-		// import archive
-		e, err := era2.From(f)
-		if err != nil {
-			f.Close()
-			return fmt.Errorf("open erae %s: %w", file, err)
-		}
-		blockCount := e.Count()
-
-		for j := uint64(0); j < blockCount; j++ {
-			hdr, err := e.GetHeader(e.Start() + j)
-			if err != nil {
-				return fmt.Errorf("header #%d: %w", hdr.Number.Uint64(), err)
-			}
-			if hdr.Number.Sign() == 0 { // skip genesis
-				continue
-			}
-			body, err := e.GetBody(hdr.Number.Uint64())
-			if err != nil {
-				return fmt.Errorf("body #%d: %w", hdr.Number.Uint64(), err)
-			}
-			rcpts, err := e.GetReceipts(hdr.Number.Uint64(), 1)
-			if err != nil {
-				return fmt.Errorf("receipts #%d: %w", hdr.Number.Uint64(), err)
-			}
-			blk := types.NewBlockWithHeader(hdr).WithBody(*body)
-
-			enc := types.EncodeBlockReceiptLists(rcpts)
-			if _, err := chain.InsertReceiptChain([]*types.Block{blk}, enc, ^uint64(0)); err != nil {
-				return fmt.Errorf("insert #%d: %w", hdr.Number.Uint64(), err)
-			}
-
-			imported++
-			if time.Since(reported) >= 8*time.Second {
-				log.Info("Importing Era‑E", "head", hdr.Number, "imported", imported, "elapsed", common.PrettyDuration(time.Since(start)))
-				reported = time.Now()
-				imported = 0
-			}
-		}
-		f.Close()
-	}
-
-	log.Info("Era‑E import complete", "duration", common.PrettyDuration(time.Since(start)))
-	return nil
-}
-
 func missingBlocks(chain *core.BlockChain, blocks []*types.Block) []*types.Block {
 	head := chain.CurrentBlock()
 	for i, block := range blocks {
@@ -516,7 +417,7 @@ func ExportAppendChain(blockchain *core.BlockChain, fn string, first uint64, las
 
 // ExportHistory exports blockchain history into the specified directory,
 // following the Era format.
-func ExportHistory(bc *core.BlockChain, dir string, first, last, step uint64) error {
+func ExportHistory(bc *core.BlockChain, dir string, first, last, step uint64, builderfn era.NewBuilderFn, filename era.FilenameFn) error {
 	log.Info("Exporting blockchain history", "dir", dir)
 	if head := bc.CurrentBlock().Number.Uint64(); head < last {
 		log.Warn("Last block beyond head, setting last = head", "head", head, "last", last)
@@ -545,7 +446,7 @@ func ExportHistory(bc *core.BlockChain, dir string, first, last, step uint64) er
 
 	for batch := first; batch <= last; batch += step {
 		idx := int(batch / step)
-		tmpPath := filepath.Join(dir, onedb.Filename(network, idx, common.Hash{}))
+		tmpPath := filepath.Join(dir, filename(network, idx, common.Hash{}))
 
 		if err := func() error {
 			fh, err := os.Create(tmpPath)
@@ -554,7 +455,7 @@ func ExportHistory(bc *core.BlockChain, dir string, first, last, step uint64) er
 			}
 			defer fh.Close()
 
-			bldr := onedb.NewBuilder(fh)
+			bldr := builderfn(fh)
 
 			for j := uint64(0); j < step && batch+j <= last; j++ {
 				n := batch + j

core/rawdb/eradb/eradb.go

@@ -308,7 +308,7 @@ func (db *Store) openEraFile(epoch uint64) (*onedb.Era, error) {
 		return nil, fmt.Errorf("pre-merge era1 file has invalid boundary. %d %% %d != 0", e.Start(), era.MaxSize)
 	}
 	log.Debug("Opened era1 file", "epoch", epoch)
-	return e, nil
+	return e.(*onedb.Era), nil
 }
 
 // doneWithFile signals that the caller has finished using a file.

internal/era/era.go

@@ -1,11 +1,17 @@
 package era
 
 import (
+	"fmt"
 	"io"
 	"math/big"
+	"os"
+	"path"
+	"strconv"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	// Removed import of internal/era to avoid import cycle and missing metadata error
 )
 
 // Type constants for the e2store entries in the Era1 and EraE formats.
@@ -36,12 +42,74 @@ type Iterator interface {
 	Next() bool
 	Number() uint64
 	Block() (*types.Block, error)
+	BlockAndReceipts() (*types.Block, types.Receipts, error)
 	Receipts() (types.Receipts, error)
 	Error() error
 }
 
 // Builder represents the interface for various types of era formats.
 type Builder interface {
-	Add(block *types.Block, receipts types.Receipts, td *big.Int, proof []byte) error
+	Add(block *types.Block, receipts types.Receipts, td *big.Int, proof Proof) error
+	AddRLP(header, body, receipts, proof []byte, number uint64, hash common.Hash, td, difficulty *big.Int) error
 	Finalize() (common.Hash, error)
 }
+
+// Era represents the interface for reading era data.
+type Era interface {
+	Close() error
+	Start() uint64
+	Count() uint64
+	GetBlockByNumber(num uint64) (*types.Block, error)
+	GetRawBodyByNumber(num uint64) ([]byte, error)
+	GetRawReceiptsByNumber(num uint64) ([]byte, error)
+}
+
+// NewBuilderFn defines a function type for creating a new Builder.
+type NewBuilderFn func(w io.Writer) Builder
+
+// FilenameFn defines a function type for generating a filename based on network, epoch, and root hash.
+type FilenameFn func(network string, epoch int, root common.Hash) string
+
+// FromFn defines a function type for creating an Era from a ReadAtSeekCloser.
+type FromFn func(f ReadAtSeekCloser) (Era, error)
+
+// NewIteratorFn defines a function type for creating a new Iterator from an Era.
+type NewIteratorFn func(e Era) (Iterator, error)
+
+// ReadDir reads all the era1 files in a directory for a given network.
+// Format: <network>-<epoch>-<hexroot>.erae or <network>-<epoch>-<hexroot>.era1
+func ReadDir(dir, network string) ([]string, error) {
+	entries, err := os.ReadDir(dir)
+	var directoryExtension string
+	if err != nil {
+		return nil, fmt.Errorf("error reading directory %s: %w", dir, err)
+	}
+	var (
+		next = uint64(0)
+		eras []string
+	)
+	for i, entry := range entries {
+		fileExtension := path.Ext(entry.Name())
+		if i == 0 {
+			directoryExtension = fileExtension
+		} else if directoryExtension != fileExtension {
+			return nil, fmt.Errorf("directory %s contains mixed era file formats", dir)
+		}
+		if fileExtension != ".erae" || fileExtension != ".era1" {
+			continue
+		}
+		parts := strings.Split(entry.Name(), "-")
+		if len(parts) != 3 || parts[0] != network {
+			// Invalid era1 filename, skip.
+			continue
+		}
+		if epoch, err := strconv.ParseUint(parts[1], 10, 64); err != nil {
+			return nil, fmt.Errorf("malformed era filenames: %s", entry.Name())
+		} else if epoch != next {
+			return nil, fmt.Errorf("missing epoch %d", next)
+		}
+		next += 1
+		eras = append(eras, entry.Name())
+	}
+	return eras, nil
+}

internal/era/execdb/builder.go

@@ -51,9 +51,11 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/history"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/internal/era"
 	"github.com/ethereum/go-ethereum/internal/era/e2store"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/golang/snappy"
 )
@@ -91,7 +93,7 @@ type Builder struct {
 }
 
 // NewBuilder returns a new Builder instance.
-func NewBuilder(w io.Writer) *Builder {
+func NewBuilder(w io.Writer) era.Builder {
 	tmp := bytes.NewBuffer(nil)
 	return &Builder{
 		w:   e2store.NewWriter(w),
@@ -137,12 +139,15 @@ func (b *Builder) Add(block *types.Block, receipts types.Receipts, td *big.Int,
 	return b.AddRLP(
 		eh, eb, er, ep,
 		header.Number.Uint64(),
-		header.Hash(), td,
+		header.Hash(), td, nil,
 	)
 }
 
 // AddRLP takes the RLP encoded block components and writes them to the underlying e2store file.
-func (b *Builder) AddRLP(headerRLP []byte, bodyRLP []byte, receipts []byte, proof []byte, blockNum uint64, blockHash common.Hash, td *big.Int) error {
+func (b *Builder) AddRLP(headerRLP []byte, bodyRLP []byte, receipts []byte, proof []byte, blockNum uint64, blockHash common.Hash, td, difficulty *big.Int) error {
+	if difficulty != nil {
+		return fmt.Errorf("block difficulty not allowed in erae format")
+	}
 	if len(b.buff.headers) >= era.MaxSize {
 		return fmt.Errorf("exceeds max size %d", era.MaxSize)
 	}
@@ -156,6 +161,11 @@ func (b *Builder) AddRLP(headerRLP []byte, bodyRLP []byte, receipts []byte, proo
 		b.buff.proofs = append(b.buff.proofs, proof)
 	}
 
+	mergeblock := history.PrunePoints[params.MainnetGenesisHash]
+	if mergeblock != nil && blockNum <= mergeblock.BlockNumber {
+		b.buff.tds = append(b.buff.tds, new(big.Int).Set(td))
+	}
+
 	// Write Era2 version before writing any blocks.
 	if b.startNum == nil {
 		b.startNum = new(uint64)

internal/era/execdb/era_test.go

@@ -139,7 +139,7 @@ func TestEra2Builder(t *testing.T) {
 			t.Fatalf("body %d mismatch", i)
 		}
 
-		rawBody, err := era.GetRawBodyFrameByNumber(bn)
+		rawBody, err := era.GetRawBodyByNumber(bn)
 		if err != nil {
 			t.Fatalf("raw body %d: %v", i, err)
 		}
@@ -153,7 +153,7 @@ func TestEra2Builder(t *testing.T) {
 			t.Fatalf("body frame %d mismatch", i)
 		}
 
-		rawRcpt, err := era.GetRawReceiptsFrameByNumber(bn)
+		rawRcpt, err := era.GetRawReceiptsByNumber(bn)
 		if err != nil {
 			t.Fatalf("raw receipts %d: %v", i, err)
 		}

internal/era/execdb/iterator.go

@@ -35,8 +35,8 @@ type Iterator struct {
 
 // NewIterator returns a header/body/receipt iterator over the archive.
 // Call Next immediately to position on the first block.
-func NewIterator(e *Era) (*Iterator, error) {
+func NewIterator(e era.Era) (era.Iterator, error) {
-	inner, err := NewRawIterator(e)
+	inner, err := NewRawIterator(e.(*Era))
 	if err != nil {
 		return nil, err
 	}

internal/era/execdb/reader.go

@@ -22,10 +22,7 @@ import (
 	"io"
 	"math/big"
 	"os"
-	"path"
 	"slices"
-	"strconv"
-	"strings"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -72,7 +69,7 @@ func (e *Era) Close() error {
 }
 
 // From returns an Era backed by f.
-func From(f era.ReadAtSeekCloser) (*Era, error) {
+func From(f era.ReadAtSeekCloser) (era.Era, error) {
 	e := &Era{f: f, s: e2store.NewReader(f)}
 	if err := e.loadIndex(); err != nil {
 		f.Close()
@@ -81,37 +78,6 @@ func From(f era.ReadAtSeekCloser) (*Era, error) {
 	return e, nil
 }
 
-// ReadDir reads all the era1 files in a directory for a given network.
-// Format: <network>-<epoch>-<hexroot>.erae
-func ReadDir(dir, network string) ([]string, error) {
-	entries, err := os.ReadDir(dir)
-	if err != nil {
-		return nil, fmt.Errorf("error reading directory %s: %w", dir, err)
-	}
-	var (
-		next = uint64(0)
-		eras []string
-	)
-	for _, entry := range entries {
-		if path.Ext(entry.Name()) != ".erae" {
-			continue
-		}
-		parts := strings.Split(entry.Name(), "-")
-		if len(parts) != 3 || parts[0] != network {
-			// Invalid era1 filename, skip.
-			continue
-		}
-		if epoch, err := strconv.ParseUint(parts[1], 10, 64); err != nil {
-			return nil, fmt.Errorf("malformed era1 filename: %s", entry.Name())
-		} else if epoch != next {
-			return nil, fmt.Errorf("missing epoch %d", next)
-		}
-		next += 1
-		eras = append(eras, entry.Name())
-	}
-	return eras, nil
-}
-
 // Start retrieves the starting block number.
 func (e *Era) Start() uint64 {
 	return e.m.start
@@ -185,8 +151,8 @@ func (e *Era) getTD(blockNum uint64) (*big.Int, error) {
 	return td, nil
 }
 
-// GetRawBodyFrameByNumber retrieves the raw body frame in bytes of a specific block.
+// GetRawBodyByNumber returns the RLP-encoded body for the given block number.
-func (e *Era) GetRawBodyFrameByNumber(blockNum uint64) ([]byte, error) {
+func (e *Era) GetRawBodyByNumber(blockNum uint64) ([]byte, error) {
 	off, err := e.bodyOff(blockNum)
 	if err != nil {
 		return nil, err
@@ -198,8 +164,8 @@ func (e *Era) GetRawBodyFrameByNumber(blockNum uint64) ([]byte, error) {
 	return io.ReadAll(r)
 }
 
-// GetRawReceiptsFrameByNumber retrieves the raw receipts frame in bytes of a specific block.
+// GetRawReceiptsByNumber returns the RLP-encoded receipts for the given block number.
-func (e *Era) GetRawReceiptsFrameByNumber(blockNum uint64) ([]byte, error) {
+func (e *Era) GetRawReceiptsByNumber(blockNum uint64) ([]byte, error) {
 	off, err := e.receiptOff(blockNum)
 	if err != nil {
 		return nil, err
@@ -211,7 +177,7 @@ func (e *Era) GetRawReceiptsFrameByNumber(blockNum uint64) ([]byte, error) {
 	return io.ReadAll(r)
 }
 
-// GetRawProofFrameByNumber retrieves the raw proof frame in bytes of a specific block proof.
+// GetRawProofFrameByNumber returns the RLP-encoded receipts for the given block number.
 func (e *Era) GetRawProofFrameByNumber(blockNum uint64) ([]byte, error) {
 	off, err := e.proofOff(blockNum)
 	if err != nil {

internal/era/onedb/builder.go

@@ -86,7 +86,7 @@ type Builder struct {
 }
 
 // NewBuilder returns a new Builder instance.
-func NewBuilder(w io.Writer) *Builder {
+func NewBuilder(w io.Writer) era.Builder {
 	buf := bytes.NewBuffer(nil)
 	return &Builder{
 		w:      e2store.NewWriter(w),
@@ -113,12 +113,15 @@ func (b *Builder) Add(block *types.Block, receipts types.Receipts, td *big.Int,
 	if err != nil {
 		return err
 	}
-	return b.AddRLP(eh, eb, er, block.NumberU64(), block.Hash(), td, block.Difficulty())
+	return b.AddRLP(eh, eb, er, nil, block.NumberU64(), block.Hash(), td, block.Difficulty())
 }
 
 // AddRLP writes a compressed block entry and compressed receipts entry to the
 // underlying e2store file.
-func (b *Builder) AddRLP(header, body, receipts []byte, number uint64, hash common.Hash, td, difficulty *big.Int) error {
+func (b *Builder) AddRLP(header, body, receipts, proof []byte, number uint64, hash common.Hash, td, difficulty *big.Int) error {
+	if proof != nil {
+		return fmt.Errorf("proof not allowed in era1 format")
+	}
 	// Write Era1 version entry before first block.
 	if b.startNum == nil {
 		n, err := b.w.Write(era.TypeVersion, nil)

internal/era/onedb/builder_test.go

@@ -67,7 +67,7 @@ func TestEra1Builder(t *testing.T) {
 			hash     = common.Hash{byte(i)}
 			td       = chain.tds[i]
 		)
-		if err = builder.AddRLP(header, body, receipts, uint64(i), hash, td, big.NewInt(1)); err != nil {
+		if err = builder.AddRLP(header, body, receipts, nil, uint64(i), hash, td, big.NewInt(1)); err != nil {
 			t.Fatalf("error adding entry: %v", err)
 		}
 	}
@@ -83,7 +83,11 @@ func TestEra1Builder(t *testing.T) {
 		t.Fatalf("failed to open era: %v", err)
 	}
 	defer e.Close()
-	it, err := NewRawIterator(e)
+	eraPtr, ok := e.(*Era)
+	if !ok {
+		t.Fatalf("failed to assert *Era type")
+	}
+	it, err := NewRawIterator(eraPtr)
 	if err != nil {
 		t.Fatalf("failed to make iterator: %s", err)
 	}
@@ -120,7 +124,7 @@ func TestEra1Builder(t *testing.T) {
 		if !bytes.Equal(rawReceipts, chain.receipts[i]) {
 			t.Fatalf("mismatched receipts: want %s, got %s", chain.receipts[i], rawReceipts)
 		}
-		receipts, err := getReceiptsByNumber(e, i)
+		receipts, err := getReceiptsByNumber(eraPtr, i)
 		if err != nil {
 			t.Fatalf("error reading receipts: %v", err)
 		}

internal/era/onedb/iterator.go

@@ -34,8 +34,8 @@ type Iterator struct {
 
 // NewIterator returns a new Iterator instance. Next must be immediately
 // called on new iterators to load the first item.
-func NewIterator(e *Era) (*Iterator, error) {
+func NewIterator(e era.Era) (era.Iterator, error) {
-	inner, err := NewRawIterator(e)
+	inner, err := NewRawIterator(e.(*Era))
 	if err != nil {
 		return nil, err
 	}

internal/era/onedb/reader.go

@@ -22,10 +22,7 @@ import (
 	"io"
 	"math/big"
 	"os"
-	"path"
 	"slices"
-	"strconv"
-	"strings"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -42,37 +39,6 @@ func Filename(network string, epoch int, root common.Hash) string {
 	return fmt.Sprintf("%s-%05d-%s.era1", network, epoch, root.Hex()[2:10])
 }
 
-// ReadDir reads all the era1 files in a directory for a given network.
-// Format: <network>-<epoch>-<hexroot>.era1
-func ReadDir(dir, network string) ([]string, error) {
-	entries, err := os.ReadDir(dir)
-	if err != nil {
-		return nil, fmt.Errorf("error reading directory %s: %w", dir, err)
-	}
-	var (
-		next = uint64(0)
-		eras []string
-	)
-	for _, entry := range entries {
-		if path.Ext(entry.Name()) != ".era1" {
-			continue
-		}
-		parts := strings.Split(entry.Name(), "-")
-		if len(parts) != 3 || parts[0] != network {
-			// Invalid era1 filename, skip.
-			continue
-		}
-		if epoch, err := strconv.ParseUint(parts[1], 10, 64); err != nil {
-			return nil, fmt.Errorf("malformed era1 filename: %s", entry.Name())
-		} else if epoch != next {
-			return nil, fmt.Errorf("missing epoch %d", next)
-		}
-		next += 1
-		eras = append(eras, entry.Name())
-	}
-	return eras, nil
-}
-
 type ReadAtSeekCloser interface {
 	io.ReaderAt
 	io.Seeker
@@ -89,7 +55,7 @@ type Era struct {
 }
 
 // From returns an Era backed by f.
-func From(f ReadAtSeekCloser) (*Era, error) {
+func From(f era.ReadAtSeekCloser) (era.Era, error) {
 	m, err := readMetadata(f)
 	if err != nil {
 		return nil, err
@@ -103,7 +69,7 @@ func From(f ReadAtSeekCloser) (*Era, error) {
 }
 
 // Open returns an Era backed by the given filename.
-func Open(filename string) (*Era, error) {
+func Open(filename string) (era.Era, error) {
 	f, err := os.Open(filename)
 	if err != nil {
 		return nil, err