snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

peer/peer.go

@@ -0,0 +1,83 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package peer defines various peer information associated with RPCs and
+// corresponding utils.
+package peer
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strings"
+
+	"google.golang.org/grpc/credentials"
+)
+
+// Peer contains the information of the peer for an RPC, such as the address
+// and authentication information.
+type Peer struct {
+	// Addr is the peer address.
+	Addr net.Addr
+	// LocalAddr is the local address.
+	LocalAddr net.Addr
+	// AuthInfo is the authentication information of the transport.
+	// It is nil if there is no transport security being used.
+	AuthInfo credentials.AuthInfo
+}
+
+// String ensures the Peer types implements the Stringer interface in order to
+// allow to print a context with a peerKey value effectively.
+func (p *Peer) String() string {
+	if p == nil {
+		return "Peer<nil>"
+	}
+	sb := &strings.Builder{}
+	sb.WriteString("Peer{")
+	if p.Addr != nil {
+		fmt.Fprintf(sb, "Addr: '%s', ", p.Addr.String())
+	} else {
+		fmt.Fprintf(sb, "Addr: <nil>, ")
+	}
+	if p.LocalAddr != nil {
+		fmt.Fprintf(sb, "LocalAddr: '%s', ", p.LocalAddr.String())
+	} else {
+		fmt.Fprintf(sb, "LocalAddr: <nil>, ")
+	}
+	if p.AuthInfo != nil {
+		fmt.Fprintf(sb, "AuthInfo: '%s'", p.AuthInfo.AuthType())
+	} else {
+		fmt.Fprintf(sb, "AuthInfo: <nil>")
+	}
+	sb.WriteString("}")
+
+	return sb.String()
+}
+
+type peerKey struct{}
+
+// NewContext creates a new context with peer information attached.
+func NewContext(ctx context.Context, p *Peer) context.Context {
+	return context.WithValue(ctx, peerKey{}, p)
+}
+
+// FromContext returns the peer information in ctx if it exists.
+func FromContext(ctx context.Context) (p *Peer, ok bool) {
+	p, ok = ctx.Value(peerKey{}).(*Peer)
+	return
+}

peer/peer_test.go

@@ -0,0 +1,101 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package peer
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"google.golang.org/grpc/credentials"
+)
+
+const defaultTestTimeout = 10 * time.Second
+
+// A struct that implements AuthInfo interface and implements CommonAuthInfo() method.
+type testAuthInfo struct {
+	credentials.CommonAuthInfo
+}
+
+func (ta testAuthInfo) AuthType() string {
+	return fmt.Sprintf("testAuthInfo-%d", ta.SecurityLevel)
+}
+
+type addr struct {
+	ipAddress string
+}
+
+func (addr) Network() string { return "" }
+
+func (a *addr) String() string { return a.ipAddress }
+
+func TestPeerStringer(t *testing.T) {
+	testCases := []struct {
+		name string
+		peer *Peer
+		want string
+	}{
+		{
+			name: "+Addr-LocalAddr+ValidAuth",
+			peer: &Peer{Addr: &addr{"example.com:1234"}, AuthInfo: testAuthInfo{credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}},
+			want: "Peer{Addr: 'example.com:1234', LocalAddr: <nil>, AuthInfo: 'testAuthInfo-3'}",
+		},
+		{
+			name: "+Addr+LocalAddr+ValidAuth",
+			peer: &Peer{Addr: &addr{"example.com:1234"}, LocalAddr: &addr{"example.com:1234"}, AuthInfo: testAuthInfo{credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}},
+			want: "Peer{Addr: 'example.com:1234', LocalAddr: 'example.com:1234', AuthInfo: 'testAuthInfo-3'}",
+		},
+		{
+			name: "+Addr-LocalAddr+emptyAuth",
+			peer: &Peer{Addr: &addr{"1.2.3.4:1234"}, AuthInfo: testAuthInfo{credentials.CommonAuthInfo{}}},
+			want: "Peer{Addr: '1.2.3.4:1234', LocalAddr: <nil>, AuthInfo: 'testAuthInfo-0'}",
+		},
+		{
+			name: "-Addr-LocalAddr+emptyAuth",
+			peer: &Peer{AuthInfo: testAuthInfo{}},
+			want: "Peer{Addr: <nil>, LocalAddr: <nil>, AuthInfo: 'testAuthInfo-0'}",
+		},
+		{
+			name: "zeroedPeer",
+			peer: &Peer{},
+			want: "Peer{Addr: <nil>, LocalAddr: <nil>, AuthInfo: <nil>}",
+		},
+		{
+			name: "nilPeer",
+			peer: nil,
+			want: "Peer<nil>",
+		},
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			ctx = NewContext(ctx, tc.peer)
+
+			p, ok := FromContext(ctx)
+			if !ok {
+				t.Fatalf("Unable to get peer from context")
+			}
+			if p.String() != tc.want {
+				t.Fatalf("Error using peer String(): expected %q, got %q", tc.want, p.String())
+			}
+		})
+	}
+}