Partial revert of https://github.com/grpc/grpc/pull/10743

include/grpc++/impl/codegen/config_protobuf.h

@@ -19,8 +19,6 @@
 #ifndef GRPCXX_IMPL_CODEGEN_CONFIG_PROTOBUF_H
 #define GRPCXX_IMPL_CODEGEN_CONFIG_PROTOBUF_H
 
-#define GRPC_OPEN_SOURCE_PROTO
-
 #ifndef GRPC_CUSTOM_PROTOBUF_INT64
 #include <google/protobuf/stubs/common.h>
 #define GRPC_CUSTOM_PROTOBUF_INT64 ::google::protobuf::int64

include/grpc++/impl/codegen/proto_utils.h

@@ -39,7 +39,8 @@ class GrpcBufferWriterPeer;
 
 const int kGrpcBufferWriterMaxBufferLength = 1024 * 1024;
 
-class GrpcBufferWriter : public ::grpc::protobuf::io::ZeroCopyOutputStream {
+class GrpcBufferWriter final
+    : public ::grpc::protobuf::io::ZeroCopyOutputStream {
  public:
   explicit GrpcBufferWriter(grpc_byte_buffer** bp, int block_size)
       : block_size_(block_size), byte_count_(0), have_backup_(false) {
@@ -87,8 +88,6 @@ class GrpcBufferWriter : public ::grpc::protobuf::io::ZeroCopyOutputStream {
 
   grpc::protobuf::int64 ByteCount() const override { return byte_count_; }
 
-  grpc_slice_buffer* SliceBuffer() { return slice_buffer_; }
-
  private:
   friend class GrpcBufferWriterPeer;
   const int block_size_;
@@ -99,7 +98,8 @@ class GrpcBufferWriter : public ::grpc::protobuf::io::ZeroCopyOutputStream {
   grpc_slice slice_;
 };
 
-class GrpcBufferReader : public ::grpc::protobuf::io::ZeroCopyInputStream {
+class GrpcBufferReader final
+    : public ::grpc::protobuf::io::ZeroCopyInputStream {
  public:
   explicit GrpcBufferReader(grpc_byte_buffer* buffer)
       : byte_count_(0), backup_count_(0), status_() {
@@ -160,7 +160,7 @@ class GrpcBufferReader : public ::grpc::protobuf::io::ZeroCopyInputStream {
     return byte_count_ - backup_count_;
   }
 
- protected:
+ private:
   int64_t byte_count_;
   int64_t backup_count_;
   grpc_byte_buffer_reader reader_;
@@ -168,12 +168,14 @@ class GrpcBufferReader : public ::grpc::protobuf::io::ZeroCopyInputStream {
   Status status_;
 };
 
-template <class BufferWriter, class T>
-Status GenericSerialize(const grpc::protobuf::Message& msg,
+}  // namespace internal
+
+template <class T>
+class SerializationTraits<T, typename std::enable_if<std::is_base_of<
+                                 grpc::protobuf::Message, T>::value>::type> {
+ public:
+  static Status Serialize(const grpc::protobuf::Message& msg,
                           grpc_byte_buffer** bp, bool* own_buffer) {
-  static_assert(
-      std::is_base_of<protobuf::io::ZeroCopyOutputStream, BufferWriter>::value,
-      "BufferWriter must be a subclass of io::ZeroCopyOutputStream");
     *own_buffer = true;
     int byte_size = msg.ByteSize();
     if (byte_size <= internal::kGrpcBufferWriterMaxBufferLength) {
@@ -185,25 +187,22 @@ Status GenericSerialize(const grpc::protobuf::Message& msg,
       g_core_codegen_interface->grpc_slice_unref(slice);
       return g_core_codegen_interface->ok();
     } else {
-    BufferWriter writer(bp, internal::kGrpcBufferWriterMaxBufferLength);
+      internal::GrpcBufferWriter writer(
+          bp, internal::kGrpcBufferWriterMaxBufferLength);
       return msg.SerializeToZeroCopyStream(&writer)
                  ? g_core_codegen_interface->ok()
                  : Status(StatusCode::INTERNAL, "Failed to serialize message");
     }
   }
 
-template <class BufferReader, class T>
-Status GenericDeserialize(grpc_byte_buffer* buffer,
+  static Status Deserialize(grpc_byte_buffer* buffer,
                             grpc::protobuf::Message* msg) {
-  static_assert(
-      std::is_base_of<protobuf::io::ZeroCopyInputStream, BufferReader>::value,
-      "BufferReader must be a subclass of io::ZeroCopyInputStream");
     if (buffer == nullptr) {
       return Status(StatusCode::INTERNAL, "No payload");
     }
     Status result = g_core_codegen_interface->ok();
     {
-    BufferReader reader(buffer);
+      internal::GrpcBufferReader reader(buffer);
       if (!reader.status().ok()) {
         return reader.status();
       }
@@ -219,32 +218,7 @@ Status GenericDeserialize(grpc_byte_buffer* buffer,
     g_core_codegen_interface->grpc_byte_buffer_destroy(buffer);
     return result;
   }
-
-}  // namespace internal
-
-// this is needed so the following class does not conflict with protobuf
-// serializers that utilize internal-only tools.
-#ifdef GRPC_OPEN_SOURCE_PROTO
-// This class provides a protobuf serializer. It translates between protobuf
-// objects and grpc_byte_buffers. More information about SerializationTraits can
-// be found in include/grpc++/impl/codegen/serialization_traits.h.
-template <class T>
-class SerializationTraits<T, typename std::enable_if<std::is_base_of<
-                                 grpc::protobuf::Message, T>::value>::type> {
- public:
-  static Status Serialize(const grpc::protobuf::Message& msg,
-                          grpc_byte_buffer** bp, bool* own_buffer) {
-    return internal::GenericSerialize<internal::GrpcBufferWriter, T>(
-        msg, bp, own_buffer);
-  }
-
-  static Status Deserialize(grpc_byte_buffer* buffer,
-                            grpc::protobuf::Message* msg) {
-    return internal::GenericDeserialize<internal::GrpcBufferReader, T>(buffer,
-                                                                       msg);
-  }
 };
-#endif
 
 }  // namespace grpc