add chain group

chain/chain.go

@@ -1,18 +1,30 @@
 package chain
 
+import (
+	"github.com/go-gost/core/metadata"
+)
+
 type Chainer interface {
 	Route(network, address string) *Route
 }
 
+type SelectableChainer interface {
+	Chainer
+	Selectable
+}
+
 type Chain struct {
-	name   string
-	groups []*NodeGroup
+	name     string
+	groups   []*NodeGroup
+	marker   Marker
+	metadata metadata.Metadata
 }
 
 func NewChain(name string, groups ...*NodeGroup) *Chain {
 	return &Chain{
 		name:   name,
 		groups: groups,
+		marker: NewFailMarker(),
 	}
 }
 
@@ -20,6 +32,18 @@ func (c *Chain) AddNodeGroup(group *NodeGroup) {
 	c.groups = append(c.groups, group)
 }
 
+func (c *Chain) WithMetadata(md metadata.Metadata) {
+	c.metadata = md
+}
+
+func (c *Chain) Metadata() metadata.Metadata {
+	return c.metadata
+}
+
+func (c *Chain) Marker() Marker {
+	return c.marker
+}
+
 func (c *Chain) Route(network, address string) (r *Route) {
 	if c == nil || len(c.groups) == 0 {
 		return
@@ -38,11 +62,11 @@ func (c *Chain) Route(network, address string) (r *Route) {
 		if node == nil {
 			return
 		}
-		if node.Transport.Multiplex() {
-			tr := node.Transport.Copy().
+		if node.transport.Multiplex() {
+			tr := node.transport.Copy().
 				WithRoute(r)
 			node = node.Copy()
-			node.Transport = tr
+			node.transport = tr
 			r = &Route{}
 		}
 
@@ -50,3 +74,27 @@ func (c *Chain) Route(network, address string) (r *Route) {
 	}
 	return r
 }
+
+type ChainGroup struct {
+	Chains   []SelectableChainer
+	Selector Selector[SelectableChainer]
+}
+
+func (p *ChainGroup) Route(network, address string) *Route {
+	if chain := p.next(); chain != nil {
+		return chain.Route(network, address)
+	}
+	return nil
+}
+
+func (p *ChainGroup) next() Chainer {
+	if p == nil || len(p.Chains) == 0 {
+		return nil
+	}
+
+	s := p.Selector
+	if s == nil {
+		s = DefaultChainSelector
+	}
+	return s.Select(p.Chains...)
+}