func BenchmarkUpdateOneFile(b *testing.B) {
	local0 := fileList{
		protocol.FileInfo{Name: "a", Version: protocol.Vector{Counters: []protocol.Counter{{ID: myID, Value: 1000}}}, Blocks: genBlocks(1)},
		protocol.FileInfo{Name: "b", Version: protocol.Vector{Counters: []protocol.Counter{{ID: myID, Value: 1000}}}, Blocks: genBlocks(2)},
		protocol.FileInfo{Name: "c", Version: protocol.Vector{Counters: []protocol.Counter{{ID: myID, Value: 1000}}}, Blocks: genBlocks(3)},
		protocol.FileInfo{Name: "d", Version: protocol.Vector{Counters: []protocol.Counter{{ID: myID, Value: 1000}}}, Blocks: genBlocks(4)},
		// A longer name is more realistic and causes more allocations
		protocol.FileInfo{Name: "zajksdhaskjdh/askjdhaskjdashkajshd/kasjdhaskjdhaskdjhaskdjash/dkjashdaksjdhaskdjahskdjh", Version: protocol.Vector{Counters: []protocol.Counter{{ID: myID, Value: 1000}}}, Blocks: genBlocks(8)},
	}

	ldb, err := db.Open("testdata/benchmarkupdate.db")
	if err != nil {
		b.Fatal(err)
	}
	defer func() {
		ldb.Close()
		os.RemoveAll("testdata/benchmarkupdate.db")
	}()

	m := db.NewFileSet("test", ldb)
	m.Replace(protocol.LocalDeviceID, local0)
	l := local0[4:5]

	for i := 0; i < b.N; i++ {
		l[0].Version = l[0].Version.Update(myID)
		m.Update(protocol.LocalDeviceID, local0)
	}

	b.ReportAllocs()
}

func main() {
	var mode string
	log.SetFlags(0)
	log.SetOutput(os.Stdout)

	flag.StringVar(&mode, "mode", "dump", "Mode of operation: dump, dumpsize")

	flag.Parse()

	path := flag.Arg(0)
	if path == "" {
		path = filepath.Join(defaultConfigDir(), "index-v0.14.0.db")
	}

	fmt.Println("Path:", path)

	ldb, err := db.Open(path)
	if err != nil {
		log.Fatal(err)
	}

	if mode == "dump" {
		dump(ldb)
	} else if mode == "dumpsize" {
		dumpsize(ldb)
	} else {
		fmt.Println("Unknown mode")
	}
}

func tempDB() (*db.Instance, string) {
	dir, err := ioutil.TempDir("", "syncthing")
	if err != nil {
		panic(err)
	}
	dbi, err := db.Open(filepath.Join(dir, "db"))
	if err != nil {
		panic(err)
	}
	return dbi, dir
}

//.........这里部分代码省略.........
		if err == nil {
			l.Warnln("Key exists; will not overwrite.")
			l.Infoln("Device ID:", protocol.NewDeviceID(cert.Certificate[0]))
		} else {
			cert, err = tlsutil.NewCertificate(certFile, keyFile, tlsDefaultCommonName, tlsRSABits)
			if err != nil {
				l.Fatalln("Create certificate:", err)
			}
			myID = protocol.NewDeviceID(cert.Certificate[0])
			if err != nil {
				l.Fatalln("Load certificate:", err)
			}
			if err == nil {
				l.Infoln("Device ID:", protocol.NewDeviceID(cert.Certificate[0]))
			}
		}

		cfgFile := filepath.Join(dir, "config.xml")
		if _, err := os.Stat(cfgFile); err == nil {
			l.Warnln("Config exists; will not overwrite.")
			return
		}
		var myName, _ = os.Hostname()
		var newCfg = defaultConfig(myName)
		var cfg = config.Wrap(cfgFile, newCfg)
		err = cfg.Save()
		if err != nil {
			l.Warnln("Failed to save config", err)
		}

		return
	}

	if info, err := os.Stat(baseDirs["config"]); err == nil && !info.IsDir() {
		l.Fatalln("Config directory", baseDirs["config"], "is not a directory")
	}

	// Ensure that our home directory exists.
	ensureDir(baseDirs["config"], 0700)

	if upgradeTo != "" {
		err := upgrade.ToURL(upgradeTo)
		if err != nil {
			l.Fatalln("Upgrade:", err) // exits 1
		}
		l.Okln("Upgraded from", upgradeTo)
		return
	}

	if doUpgrade || doUpgradeCheck {
		releasesURL := "https://api.github.com/repos/syncthing/syncthing/releases?per_page=30"
		if cfg, _, err := loadConfig(locations[locConfigFile]); err == nil {
			releasesURL = cfg.Options().ReleasesURL
		}
		rel, err := upgrade.LatestRelease(releasesURL, Version)
		if err != nil {
			l.Fatalln("Upgrade:", err) // exits 1
		}

		if upgrade.CompareVersions(rel.Tag, Version) <= 0 {
			l.Infof("No upgrade available (current %q >= latest %q).", Version, rel.Tag)
			os.Exit(exitNoUpgradeAvailable)
		}

		l.Infof("Upgrade available (current %q < latest %q)", Version, rel.Tag)

		if doUpgrade {
			// Use leveldb database locks to protect against concurrent upgrades
			_, err = db.Open(locations[locDatabase])
			if err != nil {
				l.Infoln("Attempting upgrade through running Syncthing...")
				err = upgradeViaRest()
				if err != nil {
					l.Fatalln("Upgrade:", err)
				}
				l.Okln("Syncthing upgrading")
				return
			}

			err = upgrade.To(rel)
			if err != nil {
				l.Fatalln("Upgrade:", err) // exits 1
			}
			l.Okf("Upgraded to %q", rel.Tag)
		}

		return
	}

	if reset {
		resetDB()
		return
	}

	if noRestart {
		syncthingMain()
	} else {
		monitorMain()
	}
}