Geodata: Support automatically updating .dat files and hot reloading (#5992)

https://github.com/XTLS/Xray-core/pull/5992#issuecomment-4320551920

Usage: https://github.com/XTLS/Xray-core/pull/5992#issuecomment-4291168039

app/geodata/geodata.go

@@ -0,0 +1,134 @@
+package geodata
+
+import (
+	"context"
+	"sync"
+
+	"github.com/robfig/cron/v3"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/errors"
+	commongeodata "github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/features/routing"
+)
+
+type Instance struct {
+	assets     []*Asset
+	downloader *downloader
+	tasker     *cron.Cron
+
+	mu      sync.Mutex
+	running bool
+}
+
+func New(ctx context.Context, config *Config) (*Instance, error) {
+	if config.Cron == "" {
+		return &Instance{}, nil
+	}
+
+	g := &Instance{
+		assets: config.Assets,
+	}
+
+	if len(g.assets) > 0 {
+		var dispatcher routing.Dispatcher
+		if err := core.RequireFeatures(ctx, func(d routing.Dispatcher) {
+			dispatcher = d
+		}); err != nil {
+			return nil, errors.New("failed to get dispatcher for geodata downloader").Base(err)
+		}
+		g.downloader = newDownloader(ctx, dispatcher, config.Outbound)
+	}
+
+	g.tasker = cron.New(
+		cron.WithChain(cron.SkipIfStillRunning(cron.DiscardLogger)),
+		cron.WithLogger(cron.DiscardLogger),
+	)
+	if _, err := g.tasker.AddFunc(config.Cron, g.execute); err != nil {
+		return nil, errors.New("invalid geodata cron").Base(err)
+	}
+	errors.LogInfo(ctx, "scheduled geodata reload with cron: ", config.Cron)
+
+	return g, nil
+}
+
+func (g *Instance) execute() {
+	var err error
+	if g.downloader != nil {
+		err = g.reloadWithUpdate()
+	} else {
+		err = reload()
+	}
+	if err != nil {
+		errors.LogErrorInner(context.Background(), err, "scheduled geodata reload failed")
+	}
+}
+
+func (g *Instance) reloadWithUpdate() error {
+	staged, err := g.downloader.download(g.assets)
+	if err != nil {
+		return err
+	}
+	defer clean(staged)
+
+	tx, err := swapAll(staged)
+	if err != nil {
+		return err
+	}
+
+	if err := reload(); err != nil {
+		errors.LogErrorInner(context.Background(), err, "failed to reload geodata after downloading assets, rolling back")
+		rollbackErr := tx.rollback()
+		return errors.Combine(err, rollbackErr)
+	}
+
+	return tx.commit()
+}
+
+func reload() error {
+	return errors.Combine(commongeodata.IPReg.Reload(), commongeodata.DomainReg.Reload())
+}
+
+func (g *Instance) Type() interface{} {
+	return (*Instance)(nil)
+}
+
+func (g *Instance) Start() error {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+
+	if g.running {
+		return nil
+	}
+
+	if g.tasker != nil {
+		g.tasker.Start()
+	}
+
+	g.running = true
+
+	return nil
+}
+
+func (g *Instance) Close() error {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+
+	if !g.running {
+		return nil
+	}
+
+	if g.tasker != nil {
+		<-g.tasker.Stop().Done()
+	}
+
+	g.running = false
+
+	return nil
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, cfg interface{}) (interface{}, error) {
+		return New(ctx, cfg.(*Config))
+	}))
+}