feat: initial tracing support (#1623)

vendor/google.golang.org/grpc/internal/credentials/credentials.go

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2021 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 credentials
+
+import (
+	"context"
+)
+
+// requestInfoKey is a struct to be used as the key to store RequestInfo in a
+// context.
+type requestInfoKey struct{}
+
+// NewRequestInfoContext creates a context with ri.
+func NewRequestInfoContext(ctx context.Context, ri interface{}) context.Context {
+	return context.WithValue(ctx, requestInfoKey{}, ri)
+}
+
+// RequestInfoFromContext extracts the RequestInfo from ctx.
+func RequestInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(requestInfoKey{})
+}
+
+// clientHandshakeInfoKey is a struct used as the key to store
+// ClientHandshakeInfo in a context.
+type clientHandshakeInfoKey struct{}
+
+// ClientHandshakeInfoFromContext extracts the ClientHandshakeInfo from ctx.
+func ClientHandshakeInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(clientHandshakeInfoKey{})
+}
+
+// NewClientHandshakeInfoContext creates a context with chi.
+func NewClientHandshakeInfoContext(ctx context.Context, chi interface{}) context.Context {
+	return context.WithValue(ctx, clientHandshakeInfoKey{}, chi)
+}