From 123fc1e6c81a92d0cb9512904382b4e2c3993653 Mon Sep 17 00:00:00 2001
From: longxboy <longxboyhi@gmail.com>
Date: Tue, 7 Jun 2022 22:38:21 +0800
Subject: [PATCH] feat: add peer for selector (#2088)

* add peer for selector
---
 selector/default_selector.go |  4 ++++
 selector/peer.go             | 25 +++++++++++++++++++++++++
 selector/peer_test.go        | 24 ++++++++++++++++++++++++
 transport/grpc/client.go     |  2 ++
 transport/http/client.go     |  2 ++
 5 files changed, 57 insertions(+)
 create mode 100644 selector/peer.go
 create mode 100644 selector/peer_test.go

diff --git a/selector/default_selector.go b/selector/default_selector.go
index 7550befdd..0e99249eb 100644
--- a/selector/default_selector.go
+++ b/selector/default_selector.go
@@ -53,6 +53,10 @@ func (d *Default) Select(ctx context.Context, opts ...SelectOption) (selected No
 	if err != nil {
 		return nil, nil, err
 	}
+	p, ok := FromPeerContext(ctx)
+	if ok {
+		p.Node = wn.Raw()
+	}
 	return wn.Raw(), done, nil
 }
 
diff --git a/selector/peer.go b/selector/peer.go
new file mode 100644
index 000000000..273ba0649
--- /dev/null
+++ b/selector/peer.go
@@ -0,0 +1,25 @@
+package selector
+
+import (
+	"context"
+)
+
+type peerKey struct{}
+
+// Peer contains the information of the peer for an RPC, such as the address
+// and authentication information.
+type Peer struct {
+	// node is the peer node.
+	Node Node
+}
+
+// NewPeerContext creates a new context with peer information attached.
+func NewPeerContext(ctx context.Context, p *Peer) context.Context {
+	return context.WithValue(ctx, peerKey{}, p)
+}
+
+// FromPeerContext returns the peer information in ctx if it exists.
+func FromPeerContext(ctx context.Context) (p *Peer, ok bool) {
+	p, ok = ctx.Value(peerKey{}).(*Peer)
+	return
+}
diff --git a/selector/peer_test.go b/selector/peer_test.go
new file mode 100644
index 000000000..d0eeeb819
--- /dev/null
+++ b/selector/peer_test.go
@@ -0,0 +1,24 @@
+package selector
+
+import (
+	"context"
+	"testing"
+)
+
+func TestPeer(t *testing.T) {
+	p := Peer{
+		Node: mockWeightedNode{},
+	}
+	ctx := NewPeerContext(context.Background(), &p)
+	p2, ok := FromPeerContext(ctx)
+	if !ok || p2.Node == nil {
+		t.Fatalf(" no peer found!")
+	}
+}
+
+func TestNotPeer(t *testing.T) {
+	_, ok := FromPeerContext(context.Background())
+	if ok {
+		t.Fatalf("test no peer found peer!")
+	}
+}
diff --git a/transport/grpc/client.go b/transport/grpc/client.go
index a5174b738..923e52671 100644
--- a/transport/grpc/client.go
+++ b/transport/grpc/client.go
@@ -184,6 +184,8 @@ func unaryClientInterceptor(ms []middleware.Middleware, timeout time.Duration, f
 		if len(ms) > 0 {
 			h = middleware.Chain(ms...)(h)
 		}
+		var p selector.Peer
+		ctx = selector.NewPeerContext(ctx, &p)
 		_, err := h(ctx, req)
 		return err
 	}
diff --git a/transport/http/client.go b/transport/http/client.go
index 2ae29ffb2..f1c213598 100644
--- a/transport/http/client.go
+++ b/transport/http/client.go
@@ -247,6 +247,8 @@ func (client *Client) invoke(ctx context.Context, req *http.Request, args interf
 		}
 		return reply, nil
 	}
+	var p selector.Peer
+	ctx = selector.NewPeerContext(ctx, &p)
 	if len(client.opts.middleware) > 0 {
 		h = middleware.Chain(client.opts.middleware...)(h)
 	}