add attributes package

internal/attributes/attributes.go

@@ -0,0 +1,55 @@
+/*
+ *
+ * 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 attributes contains functions for getting and setting attributes.
+package attributes
+
+import (
+	"net/url"
+
+	"google.golang.org/grpc/resolver"
+)
+
+type keyType string
+
+const userAndConnectAddrKey = keyType("grpc.resolver.delegatingresolver.userAndConnectAddr")
+
+type attr struct {
+	user *url.Userinfo
+	addr string
+}
+
+// SetUserAndConnectAddr returns a copy of the provided resolver.Address with
+// attributes containing address to be sent in connect request to proxy and the
+// user info.  It's data should not be mutated after calling SetConnectAddr.
+func SetUserAndConnectAddr(resAddr resolver.Address, user *url.Userinfo, addr string) resolver.Address {
+	resAddr.Attributes = resAddr.Attributes.WithValue(userAndConnectAddrKey, attr{user: user, addr: addr})
+	return resAddr
+}
+
+// ProxyConnectAddr returns the proxy connect address in resolver.Address, or nil
+// if not present. The returned data should not be mutated.
+func ProxyConnectAddr(addr resolver.Address) string {
+	return addr.Attributes.Value(userAndConnectAddrKey).(attr).addr
+}
+
+// User returns the user info in the resolver.Address, or nil if not present.
+// The returned data should not be mutated.
+func User(addr resolver.Address) *url.Userinfo {
+	return addr.Attributes.Value(userAndConnectAddrKey).(attr).user
+}

internal/resolver/delegatingresolver/delegatingresolver.go

@@ -30,6 +30,7 @@ import (
 	"sync"
 
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/attributes"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/serviceconfig"
 )
@@ -147,41 +148,12 @@ func (r *delegatingResolver) Close() {
 	}
 }
 
-type keyType string
-
-const userAndConnectAddrKey = keyType("grpc.resolver.delegatingresolver.userAndConnectAddr")
-
-type attr struct {
-	user *url.Userinfo
-	addr string
-}
-
-// SetUserAndConnectAddr returns a copy of the provided resolver.Address with
-// attributes containing address to be sent in connect request to proxy and the
-// user info.  It's data should not be mutated after calling SetConnectAddr.
-func SetUserAndConnectAddr(resAddr resolver.Address, user *url.Userinfo, addr string) resolver.Address {
-	resAddr.Attributes = resAddr.Attributes.WithValue(userAndConnectAddrKey, attr{user: user, addr: addr})
-	return resAddr
-}
-
-// ProxyConnectAddr returns the proxy connect address in resolver.Address, or nil
-// if not present. The returned data should not be mutated.
-func ProxyConnectAddr(addr resolver.Address) string {
-	return addr.Attributes.Value(userAndConnectAddrKey).(attr).addr
-}
-
-// User returns the user info in the resolver.Address, or nil if not present.
-// The returned data should not be mutated.
-func User(addr resolver.Address) *url.Userinfo {
-	return addr.Attributes.Value(userAndConnectAddrKey).(attr).user
-}
-
 func (r *delegatingResolver) updateState() []resolver.Address {
 	var addresses []resolver.Address
 	for _, proxyAddr := range r.proxyAddrs {
 		for _, targetAddr := range r.targetAddrs {
 			newAddr := resolver.Address{Addr: proxyAddr.Addr}
-			newAddr = SetUserAndConnectAddr(newAddr, r.proxyURL.User, targetAddr.Addr)
+			newAddr = attributes.SetUserAndConnectAddr(newAddr, r.proxyURL.User, targetAddr.Addr)
 			addresses = append(addresses, newAddr)
 		}
 	}

internal/resolver/delegatingresolver/delegatingresolver_test.go

@@ -24,6 +24,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc/internal/attributes"
 	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/testutils"
 	"google.golang.org/grpc/resolver"
@@ -182,7 +183,7 @@ func (s) TestDelegatingResolverwithDNSAndProxyWithTargetResolution(t *testing.T)
 
 	// Verify that the delegating resolver outputs the same address.
 	expectedAddr := resolver.Address{Addr: resolvedProxyTestAddr}
-	expectedAddr = SetUserAndConnectAddr(expectedAddr, nil, resolvedTargetTestAddr)
+	expectedAddr = attributes.SetUserAndConnectAddr(expectedAddr, nil, resolvedTargetTestAddr)
 	expectedState := resolver.State{Addresses: []resolver.Address{expectedAddr}}
 
 	if state := <-stateCh; len(state.Addresses) != 1 || !cmp.Equal(expectedState, state) {
@@ -226,7 +227,7 @@ func (s) TestDelegatingResolverwithDNSAndProxyWithNoTargetResolution(t *testing.
 
 	// Verify that the delegating resolver outputs the same address.
 	expectedAddr := resolver.Address{Addr: resolvedProxyTestAddr}
-	expectedAddr = SetUserAndConnectAddr(expectedAddr, nil, targetTestAddr)
+	expectedAddr = attributes.SetUserAndConnectAddr(expectedAddr, nil, targetTestAddr)
 	expectedState := resolver.State{Addresses: []resolver.Address{expectedAddr}}
 
 	if state := <-stateCh; len(state.Addresses) != 1 || !cmp.Equal(expectedState, state) {
@@ -279,16 +280,16 @@ func (s) TestDelegatingResolverwithCustomResolverAndProxy(t *testing.T) {
 	})
 
 	expectedAddr := resolver.Address{Addr: resolvedProxyTestAddr}
-	expectedAddr = SetUserAndConnectAddr(expectedAddr, nil, resolvedTargetTestAddr)
+	expectedAddr = attributes.SetUserAndConnectAddr(expectedAddr, nil, resolvedTargetTestAddr)
 
 	expectedAddr1 := resolver.Address{Addr: resolvedProxyTestAddr}
-	expectedAddr1 = SetUserAndConnectAddr(expectedAddr1, nil, resolvedTargetTestAddr1)
+	expectedAddr1 = attributes.SetUserAndConnectAddr(expectedAddr1, nil, resolvedTargetTestAddr1)
 
 	expectedAddr2 := resolver.Address{Addr: resolvedProxyTestAddr1}
-	expectedAddr2 = SetUserAndConnectAddr(expectedAddr2, nil, resolvedTargetTestAddr)
+	expectedAddr2 = attributes.SetUserAndConnectAddr(expectedAddr2, nil, resolvedTargetTestAddr)
 
 	expectedAddr3 := resolver.Address{Addr: resolvedProxyTestAddr1}
-	expectedAddr3 = SetUserAndConnectAddr(expectedAddr3, nil, resolvedTargetTestAddr1)
+	expectedAddr3 = attributes.SetUserAndConnectAddr(expectedAddr3, nil, resolvedTargetTestAddr1)
 
 	expectedState := resolver.State{Addresses: []resolver.Address{
 		expectedAddr,