core/rawdb: scaffold era database

core/rawdb/eradb/eradb.go

@@ -0,0 +1,131 @@
+// Copyright 2025 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package eradb
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/internal/era"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+type EraDatabase struct {
+	datadir string
+	table   map[uint64]*era.Era
+	mu      sync.RWMutex
+}
+
+// New creates a new EraDatabase instance.
+func New(datadir string) (*EraDatabase, error) {
+	// Ensure the datadir is not a symbolic link if it exists.
+	if info, err := os.Lstat(datadir); !os.IsNotExist(err) {
+		if info == nil {
+			log.Warn("Could not Lstat the database", "path", datadir)
+			return nil, errors.New("lstat failed")
+		}
+		if info.Mode()&os.ModeSymlink != 0 {
+			log.Warn("Symbolic link erastore is not supported", "path", datadir)
+			return nil, errors.New("symbolic link datadir is not supported")
+		}
+	}
+	if err := os.MkdirAll(datadir, 0755); err != nil {
+		return nil, err
+	}
+	log.Info("Opened erastore", "datadir", datadir)
+	return &EraDatabase{datadir: datadir, table: make(map[uint64]*era.Era)}, nil
+}
+
+// scan returns a list of all era1 files in the datadir.
+func (db *EraDatabase) scan() ([]string, error) {
+	entries, err := os.ReadDir(db.datadir)
+	if err != nil {
+		return nil, err
+	}
+	var files []string
+	for _, entry := range entries {
+		if entry.IsDir() || entry.Type()&os.ModeSymlink != 0 {
+			continue
+		}
+		// Skip files that are not era1 files.
+		if path.Ext(entry.Name()) != ".era1" {
+			continue
+		}
+		files = append(files, entry.Name())
+	}
+	return files, nil
+}
+
+func (db *EraDatabase) openEra(name string) (*era.Era, error) {
+	e, err := era.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	// Assign an epoch to the table.
+	if e.Count() != uint64(era.MaxEra1Size) {
+		return nil, fmt.Errorf("pre-merge era1 files must be full. Want: %d, have: %d", era.MaxEra1Size, e.Count())
+	}
+	if e.Start()%uint64(era.MaxEra1Size) != 0 {
+		return nil, fmt.Errorf("pre-merge era1 file has invalid boundary. %d %% %d != 0", e.Start(), era.MaxEra1Size)
+	}
+	epoch := e.Start() / uint64(era.MaxEra1Size)
+	db.mu.Lock()
+	db.table[epoch] = e
+	db.mu.Unlock()
+	return e, nil
+}
+
+func (db *EraDatabase) Close() {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+	for _, e := range db.table {
+		if err := e.Close(); err != nil {
+			log.Warn("Failed to close era", "error", err)
+		}
+	}
+	db.table = nil
+}
+
+func (db *EraDatabase) GetBlockByNumber(number uint64) (*types.Block, error) {
+	files, err := db.scan()
+	if err != nil {
+		return nil, err
+	}
+	for _, file := range files {
+		_, err := db.openEra(path.Join(db.datadir, file))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Lookup the table by epoch.
+	epoch := number / uint64(era.MaxEra1Size)
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	if e, ok := db.table[epoch]; ok {
+		block, err := e.GetBlockByNumber(number)
+		if err == nil {
+			return block, nil
+		}
+	}
+
+	return nil, errors.New("block not found")
+}

core/rawdb/eradb/eradb_test.go

@@ -0,0 +1,39 @@
+// Copyright 2025 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package eradb
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestEraDatabase_Scan(t *testing.T) {
+	// Create the database
+	db, err := New("testdata")
+	require.NoError(t, err)
+
+	// Scan for era files
+	files, err := db.scan()
+	require.NoError(t, err)
+
+	t.Log(files)
+	block, err := db.GetBlockByNumber(15000)
+	require.NoError(t, err)
+	defer db.Close()
+	require.Equal(t, uint64(15000), block.NumberU64())
+}