feat: optional MySQL/MariaDB database driver for deployments that cannot use local SQLite

internal/infrastructure/persistence/database/dumpBackup.go

@@ -0,0 +1,79 @@
+package database
+
+import (
+	domain "RenewCMS/internal/domain/update"
+	"bufio"
+	"os"
+	"time"
+)
+
+const (
+	dumpFileExtension        = ".sql"
+	dumpPartialFileExtension = ".partial"
+)
+
+type DumpBackup struct {
+	open      func() (DumpSource, error)
+	directory string
+	now       func() time.Time
+}
+
+var _ domain.DatabaseBackup = &DumpBackup{}
+
+func NewDumpBackup(open func() (DumpSource, error), directory string, now func() time.Time) *DumpBackup {
+	return &DumpBackup{open: open, directory: directory, now: now}
+}
+
+func (b *DumpBackup) Backup() (string, error) {
+	target, err := newBackupTarget(b.directory, b.now(), dumpFileExtension)
+	if err != nil {
+		return "", err
+	}
+	if err := b.writeAtomically(target); err != nil {
+		return "", err
+	}
+	if err := pruneBackups(b.directory, dumpFileExtension); err != nil {
+		return "", err
+	}
+	return target, nil
+}
+
+func (b *DumpBackup) writeAtomically(target string) error {
+	partial := target + dumpPartialFileExtension
+	if err := b.writePartial(partial); err != nil {
+		_ = os.Remove(partial)
+		return err
+	}
+	if err := os.Rename(partial, target); err != nil {
+		_ = os.Remove(partial)
+		return err
+	}
+	return nil
+}
+
+func (b *DumpBackup) writePartial(partial string) error {
+	source, err := b.open()
+	if err != nil {
+		return err
+	}
+	defer source.Close()
+
+	file, err := os.OpenFile(partial, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o600)
+	if err != nil {
+		return err
+	}
+	buffered := bufio.NewWriter(file)
+	if err := WriteDump(buffered, source); err != nil {
+		_ = file.Close()
+		return err
+	}
+	if err := buffered.Flush(); err != nil {
+		_ = file.Close()
+		return err
+	}
+	if err := file.Sync(); err != nil {
+		_ = file.Close()
+		return err
+	}
+	return file.Close()
+}