update chain route

chain/hop.go

@@ -0,0 +1,87 @@
+package chain
+
+import (
+	"context"
+
+	"github.com/go-gost/core/bypass"
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/selector"
+)
+
+type HopOptions struct {
+	bypass   bypass.Bypass
+	selector selector.Selector[*chain.Node]
+}
+
+type HopOption func(*HopOptions)
+
+func BypassHopOption(bp bypass.Bypass) HopOption {
+	return func(o *HopOptions) {
+		o.bypass = bp
+	}
+}
+
+func SelectorHopOption(s selector.Selector[*chain.Node]) HopOption {
+	return func(o *HopOptions) {
+		o.selector = s
+	}
+}
+
+type chainHop struct {
+	nodes   []*chain.Node
+	options HopOptions
+}
+
+func NewChainHop(nodes []*chain.Node, opts ...HopOption) chain.Hop {
+	var options HopOptions
+	for _, opt := range opts {
+		if opt != nil {
+			opt(&options)
+		}
+	}
+
+	return &chainHop{
+		nodes:   nodes,
+		options: options,
+	}
+}
+
+func (p *chainHop) Nodes() []*chain.Node {
+	return p.nodes
+}
+
+func (p *chainHop) Select(ctx context.Context, opts ...chain.SelectOption) *chain.Node {
+	var options chain.SelectOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	if p == nil || len(p.nodes) == 0 {
+		return nil
+	}
+
+	// hop level bypass
+	if p.options.bypass != nil && p.options.bypass.Contains(options.Addr) {
+		return nil
+	}
+
+	var nodes []*chain.Node
+	for _, node := range p.nodes {
+		if node == nil {
+			continue
+		}
+		// node level bypass
+		if node.Options().Bypass != nil && node.Options().Bypass.Contains(options.Addr) {
+			continue
+		}
+		nodes = append(nodes, node)
+	}
+	if len(nodes) == 0 {
+		return nil
+	}
+
+	if s := p.options.selector; s != nil {
+		return s.Select(ctx, nodes...)
+	}
+	return nodes[0]
+}