refactor: DNS

dns/transport_registry.go

@@ -0,0 +1,72 @@
+package dns
+
+import (
+	"context"
+	"sync"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+type TransportConstructorFunc[T any] func(ctx context.Context, logger log.ContextLogger, tag string, options T) (adapter.DNSTransport, error)
+
+func RegisterTransport[Options any](registry *TransportRegistry, transportType string, constructor TransportConstructorFunc[Options]) {
+	registry.register(transportType, func() any {
+		return new(Options)
+	}, func(ctx context.Context, logger log.ContextLogger, tag string, rawOptions any) (adapter.DNSTransport, error) {
+		var options *Options
+		if rawOptions != nil {
+			options = rawOptions.(*Options)
+		}
+		return constructor(ctx, logger, tag, common.PtrValueOrDefault(options))
+	})
+}
+
+var _ adapter.DNSTransportRegistry = (*TransportRegistry)(nil)
+
+type (
+	optionsConstructorFunc func() any
+	constructorFunc        func(ctx context.Context, logger log.ContextLogger, tag string, options any) (adapter.DNSTransport, error)
+)
+
+type TransportRegistry struct {
+	access       sync.Mutex
+	optionsType  map[string]optionsConstructorFunc
+	constructors map[string]constructorFunc
+}
+
+func NewTransportRegistry() *TransportRegistry {
+	return &TransportRegistry{
+		optionsType:  make(map[string]optionsConstructorFunc),
+		constructors: make(map[string]constructorFunc),
+	}
+}
+
+func (r *TransportRegistry) CreateOptions(transportType string) (any, bool) {
+	r.access.Lock()
+	defer r.access.Unlock()
+	optionsConstructor, loaded := r.optionsType[transportType]
+	if !loaded {
+		return nil, false
+	}
+	return optionsConstructor(), true
+}
+
+func (r *TransportRegistry) CreateDNSTransport(ctx context.Context, logger log.ContextLogger, tag string, transportType string, options any) (adapter.DNSTransport, error) {
+	r.access.Lock()
+	defer r.access.Unlock()
+	constructor, loaded := r.constructors[transportType]
+	if !loaded {
+		return nil, E.New("transport type not found: " + transportType)
+	}
+	return constructor(ctx, logger, tag, options)
+}
+
+func (r *TransportRegistry) register(transportType string, optionsConstructor optionsConstructorFunc, constructor constructorFunc) {
+	r.access.Lock()
+	defer r.access.Unlock()
+	r.optionsType[transportType] = optionsConstructor
+	r.constructors[transportType] = constructor
+}