add hop

chain/chain.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/logger"
 	"github.com/go-gost/core/metadata"
 	"github.com/go-gost/core/selector"
 )
@@ -12,6 +13,25 @@ var (
 	_ chain.Chainer = (*chainGroup)(nil)
 )
 
+type ChainOptions struct {
+	Metadata metadata.Metadata
+	Logger   logger.Logger
+}
+
+type ChainOption func(*ChainOptions)
+
+func MetadataChainOption(md metadata.Metadata) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Metadata = md
+	}
+}
+
+func LoggerChainOption(logger logger.Logger) ChainOption {
+	return func(opts *ChainOptions) {
+		opts.Logger = logger
+	}
+}
+
 type chainNamer interface {
 	Name() string
 }
@@ -21,13 +41,22 @@ type Chain struct {
 	hops     []chain.Hop
 	marker   selector.Marker
 	metadata metadata.Metadata
+	logger   logger.Logger
 }
 
-func NewChain(name string, hops ...chain.Hop) *Chain {
+func NewChain(name string, opts ...ChainOption) *Chain {
+	var options ChainOptions
+	for _, opt := range opts {
+		if opt != nil {
+			opt(&options)
+		}
+	}
+
 	return &Chain{
-		name:   name,
-		hops:   hops,
-		marker: selector.NewFailMarker(),
+		name:     name,
+		metadata: options.Metadata,
+		marker:   selector.NewFailMarker(),
+		logger:   options.Logger,
 	}
 }
 
@@ -35,10 +64,6 @@ 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