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

common/geodata/domain_registry.go

@@ -1,11 +1,59 @@
 package geodata
 
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
 type DomainRegistry struct {
-	factory DomainMatcherFactory
+	mu       sync.Mutex
+	factory  DomainMatcherFactory
+	matchers []*DynamicDomainMatcher
 }
 
 func (r *DomainRegistry) BuildDomainMatcher(rules []*DomainRule) (DomainMatcher, error) {
-	return r.factory.BuildMatcher(rules)
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	m, err := r.factory.BuildMatcher(rules)
+	if err != nil {
+		return nil, err
+	}
+
+	d := NewDynamicDomainMatcher(rules, m)
+	r.matchers = append(r.matchers, d)
+	return d, nil
+}
+
+func (r *DomainRegistry) Reload() error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	errors.LogInfo(context.Background(), "reloading GeoSite data for ", len(r.matchers), " domain matcher(s)")
+
+	factory := newDomainMatcherFactory()
+	type reloadEntry struct {
+		dynamic *DynamicDomainMatcher
+		matcher DomainMatcher
+	}
+	reloaded := make([]reloadEntry, len(r.matchers))
+	for i, d := range r.matchers {
+		m, err := factory.BuildMatcher(d.rules)
+		if err != nil {
+			errors.LogErrorInner(context.Background(), err, "failed to reload GeoSite data for domain matcher ", i)
+			return err
+		}
+		reloaded[i] = reloadEntry{dynamic: d, matcher: m}
+	}
+	for _, entry := range reloaded {
+		entry.dynamic.Reload(entry.matcher)
+	}
+	r.factory = factory
+	errors.LogInfo(context.Background(), "reloaded GeoSite data for ", len(r.matchers), " domain matcher(s)")
+	return nil
 }
 
 func newDomainRegistry() *DomainRegistry {
@@ -15,3 +63,32 @@ func newDomainRegistry() *DomainRegistry {
 }
 
 var DomainReg = newDomainRegistry()
+
+type domainMatcherState struct {
+	matcher DomainMatcher
+}
+
+type DynamicDomainMatcher struct {
+	rules []*DomainRule
+	state atomic.Pointer[domainMatcherState]
+}
+
+// Match implements DomainMatcher.
+func (d *DynamicDomainMatcher) Match(input string) []uint32 {
+	return d.state.Load().matcher.Match(input)
+}
+
+// MatchAny implements DomainMatcher.
+func (d *DynamicDomainMatcher) MatchAny(input string) bool {
+	return d.state.Load().matcher.MatchAny(input)
+}
+
+func (d *DynamicDomainMatcher) Reload(newMatcher DomainMatcher) {
+	d.state.Store(&domainMatcherState{matcher: newMatcher})
+}
+
+func NewDynamicDomainMatcher(rules []*DomainRule, matcher DomainMatcher) *DynamicDomainMatcher {
+	d := &DynamicDomainMatcher{rules: rules}
+	d.Reload(matcher)
+	return d
+}