feat: 实现配置校验与运维命令及优雅停机

cmd/nixmsg/backup.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"git.asio.asia/nixevol/NixMsg/internal/store"
+)
+
+func cmdBackup(args []string) error {
+	outPath, err := parseBackupArgs(args)
+	if err != nil {
+		return err
+	}
+	cfg, err := loadAndValidateConfig()
+	if err != nil {
+		return err
+	}
+	if dir := filepath.Dir(outPath); dir != "" && dir != "." {
+		if mkErr := os.MkdirAll(dir, 0o755); mkErr != nil {
+			return fmt.Errorf("mkdir backup dir: %w", mkErr)
+		}
+	}
+	absOut, err := filepath.Abs(outPath)
+	if err != nil {
+		return err
+	}
+	ctx := context.Background()
+	// 对运行中的库：单独打开写连接执行 VACUUM INTO（可与 serve 并存，WAL 下安全）。
+	write, err := store.OpenWriter(cfg.DataDir, cfg.SQLiteSynchronous)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = write.Close() }()
+	if err := store.VacuumInto(ctx, write, filepath.ToSlash(absOut)); err != nil {
+		return err
+	}
+	fmt.Fprintf(os.Stderr, "backup written to %s\n", absOut)
+	return nil
+}
+
+func parseBackupArgs(args []string) (string, error) {
+	var out string
+	for i := 0; i < len(args); i++ {
+		switch args[i] {
+		case "--out":
+			if i+1 >= len(args) {
+				return "", errors.New("usage: nixmsg backup --out <file.db>")
+			}
+			out = args[i+1]
+			i++
+		default:
+			return "", fmt.Errorf("unknown argument: %s", args[i])
+		}
+	}
+	if out == "" {
+		return "", errors.New("usage: nixmsg backup --out <file.db>")
+	}
+	return out, nil
+}