update chain route

chain/chain.go

@@ -0,0 +1,107 @@
+package chain
+
+import (
+	"context"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/metadata"
+	"github.com/go-gost/core/selector"
+)
+
+var (
+	_ chain.Chainer = (*chainGroup)(nil)
+)
+
+type chainNamer interface {
+	Name() string
+}
+
+type Chain struct {
+	name     string
+	hops     []chain.Hop
+	marker   selector.Marker
+	metadata metadata.Metadata
+}
+
+func NewChain(name string, hops ...chain.Hop) *Chain {
+	return &Chain{
+		name:   name,
+		hops:   hops,
+		marker: selector.NewFailMarker(),
+	}
+}
+
+func (c *Chain) AddHop(hop chain.Hop) {
+	c.hops = append(c.hops, hop)
+}
+
+func (c *Chain) WithMetadata(md metadata.Metadata) {
+	c.metadata = md
+}
+
+// Metadata implements metadata.Metadatable interface.
+func (c *Chain) Metadata() metadata.Metadata {
+	return c.metadata
+}
+
+// Marker implements selector.Markable interface.
+func (c *Chain) Marker() selector.Marker {
+	return c.marker
+}
+
+func (c *Chain) Name() string {
+	return c.name
+}
+
+func (c *Chain) Route(ctx context.Context, network, address string) chain.Route {
+	if c == nil || len(c.hops) == 0 {
+		return nil
+	}
+
+	rt := NewRoute(ChainRouteOption(c))
+	for _, hop := range c.hops {
+		node := hop.Select(ctx, chain.AddrSelectOption(address))
+		if node == nil {
+			return rt
+		}
+		if node.Options().Transport.Multiplex() {
+			tr := node.Options().Transport.Copy()
+			tr.Options().Route = rt
+			node = node.Copy()
+			node.Options().Transport = tr
+			rt = NewRoute()
+		}
+
+		rt.addNode(node)
+	}
+	return rt
+}
+
+type chainGroup struct {
+	chains   []chain.Chainer
+	selector selector.Selector[chain.Chainer]
+}
+
+func NewChainGroup(chains ...chain.Chainer) *chainGroup {
+	return &chainGroup{chains: chains}
+}
+
+func (p *chainGroup) WithSelector(s selector.Selector[chain.Chainer]) *chainGroup {
+	p.selector = s
+	return p
+}
+
+func (p *chainGroup) Route(ctx context.Context, network, address string) chain.Route {
+	if chain := p.next(ctx); chain != nil {
+		return chain.Route(ctx, network, address)
+	}
+	return nil
+}
+
+func (p *chainGroup) next(ctx context.Context) chain.Chainer {
+	if p == nil || len(p.chains) == 0 {
+		return nil
+	}
+
+	return p.selector.Select(ctx, p.chains...)
+}