Initial commit

adapters/repository/badger/db.go

@@ -0,0 +1,128 @@
+package badger
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path"
+
+	"github.com/dgraph-io/badger/v4"
+	"github.com/dgraph-io/badger/v4/options"
+	"go.uber.org/zap"
+)
+
+const (
+	backupStartPath = "backup_start.db"
+	backupStopPath  = "backup_stop.db"
+)
+
+type BackupType uint8
+
+const (
+	BackupStart BackupType = iota
+	BackupStop
+)
+
+var ErrDBClosed = fmt.Errorf("database is closed")
+
+type logger struct {
+	*zap.SugaredLogger
+}
+
+func (l *logger) Warningf(s string, i ...interface{}) {
+	l.SugaredLogger.Warnf(s, i...)
+}
+
+func NewBadger(dir string, log *zap.Logger) (*badger.DB, error) {
+	opts := badger.DefaultOptions(dir)
+	opts.Logger = &logger{SugaredLogger: log.Sugar()}
+	opts.Compression = options.ZSTD
+	opts.ZSTDCompressionLevel = 6
+
+	db, err := badger.Open(opts)
+	if err != nil {
+		return nil, fmt.Errorf("open database: %w", err)
+	}
+
+	if err := Backup(db, BackupStart); err != nil {
+		log.Error("backup on start failed", zap.Error(err))
+	}
+
+	return db, nil
+}
+
+func Backup(db *badger.DB, bt BackupType) error {
+	dir := db.Opts().Dir
+	var backupPath string
+
+	switch bt {
+	case BackupStart:
+		backupPath = path.Join(dir, backupStartPath)
+	case BackupStop:
+		backupPath = path.Join(dir, backupStopPath)
+	}
+
+	file, err := os.OpenFile(backupPath, os.O_CREATE|os.O_WRONLY, os.FileMode(0600))
+	if err != nil {
+		return fmt.Errorf("open backup file %s: %w", backupPath, err)
+	}
+	defer func() {
+		_ = file.Close()
+	}()
+
+	_, err = db.Backup(file, 0)
+	if err != nil {
+		return fmt.Errorf("backup: %w", err)
+	}
+
+	return nil
+}
+
+func Restore(db *badger.DB) error {
+	dir := db.Opts().Dir
+
+	backupPathStart := path.Join(dir, backupStartPath)
+	backupPathStop := path.Join(dir, backupStopPath)
+
+	startStat, err := os.Stat(backupPathStart)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("stat file %s: %w", backupPathStart, err)
+	}
+
+	stopStat, err := os.Stat(backupPathStop)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("stat file %s: %w", backupPathStop, err)
+	}
+
+	var backupFile string
+
+	switch {
+	case stopStat != nil && startStat != nil:
+		if stopStat.ModTime().After(startStat.ModTime()) {
+			backupFile = backupPathStop
+		} else {
+			backupFile = backupPathStart
+		}
+
+	case stopStat != nil:
+		backupFile = backupPathStart
+
+	case startStat != nil:
+		backupFile = backupPathStop
+	}
+
+	file, err := os.OpenFile(backupFile, os.O_RDONLY, os.FileMode(0600))
+	if err != nil {
+		return fmt.Errorf("open backup file %s: %w", backupFile, err)
+	}
+
+	defer func() {
+		_ = file.Close()
+	}()
+
+	if err := db.Load(file, 20); err != nil {
+		return fmt.Errorf("load backup: %w", err)
+	}
+
+	return nil
+}