Add to codegen interface, refactor proto serialization

This change allows for some internal proto serialization
changes to be made

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

@@ -34,6 +34,8 @@
 #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/core_codegen.h

@@ -79,11 +79,15 @@ class CoreCodegen : public CoreCodegenInterface {
 
   grpc_byte_buffer* grpc_raw_byte_buffer_create(grpc_slice* slice,
                                                 size_t nslices) override;
-
+  grpc_slice grpc_slice_new_with_user_data(void* p, size_t len,
+                                           void (*destroy)(void*),
+                                           void* user_data) override;
   grpc_slice grpc_empty_slice() override;
   grpc_slice grpc_slice_malloc(size_t length) override;
   void grpc_slice_unref(grpc_slice slice) override;
+  grpc_slice grpc_slice_ref(grpc_slice slice) override;
   grpc_slice grpc_slice_split_tail(grpc_slice* s, size_t split) override;
+  grpc_slice grpc_slice_split_head(grpc_slice* s, size_t split) override;
   void grpc_slice_buffer_add(grpc_slice_buffer* sb, grpc_slice slice) override;
   void grpc_slice_buffer_pop(grpc_slice_buffer* sb) override;
   grpc_slice grpc_slice_from_static_buffer(const void* buffer,

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

@@ -95,11 +95,15 @@ class CoreCodegenInterface {
 
   virtual grpc_byte_buffer* grpc_raw_byte_buffer_create(grpc_slice* slice,
                                                         size_t nslices) = 0;
-
+  virtual grpc_slice grpc_slice_new_with_user_data(void* p, size_t len,
+                                                     void (*destroy)(void*),
+                                                     void* user_data) = 0;
   virtual grpc_slice grpc_empty_slice() = 0;
   virtual grpc_slice grpc_slice_malloc(size_t length) = 0;
   virtual void grpc_slice_unref(grpc_slice slice) = 0;
+  virtual grpc_slice grpc_slice_ref(grpc_slice slice) = 0;
   virtual grpc_slice grpc_slice_split_tail(grpc_slice* s, size_t split) = 0;
+  virtual grpc_slice grpc_slice_split_head(grpc_slice* s, size_t split) = 0;
   virtual void grpc_slice_buffer_add(grpc_slice_buffer* sb,
                                      grpc_slice slice) = 0;
   virtual void grpc_slice_buffer_pop(grpc_slice_buffer* sb) = 0;

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

@@ -54,8 +54,7 @@ class GrpcBufferWriterPeer;
 
 const int kGrpcBufferWriterMaxBufferLength = 8192;
 
-class GrpcBufferWriter final
-    : public ::grpc::protobuf::io::ZeroCopyOutputStream {
+class GrpcBufferWriter : 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) {
@@ -103,6 +102,8 @@ class GrpcBufferWriter final
 
   grpc::protobuf::int64 ByteCount() const override { return byte_count_; }
 
+  grpc_slice_buffer* SliceBuffer() { return slice_buffer_; }
+
  private:
   friend class GrpcBufferWriterPeer;
   const int block_size_;
@@ -113,8 +114,7 @@ class GrpcBufferWriter final
   grpc_slice slice_;
 };
 
-class GrpcBufferReader final
-    : public ::grpc::protobuf::io::ZeroCopyInputStream {
+class GrpcBufferReader : public ::grpc::protobuf::io::ZeroCopyInputStream {
  public:
   explicit GrpcBufferReader(grpc_byte_buffer* buffer)
       : byte_count_(0), backup_count_(0), status_() {
@@ -175,20 +175,17 @@ class GrpcBufferReader final
     return byte_count_ - backup_count_;
   }
 
- private:
+ protected:
   int64_t byte_count_;
   int64_t backup_count_;
   grpc_byte_buffer_reader reader_;
   grpc_slice slice_;
   Status status_;
 };
-}  // 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,
+// BufferWriter must be a subclass of io::ZeroCopyOutputStream.
+template <class BufferWriter, class T>
+Status GenericSerialize(const grpc::protobuf::Message& msg,
                         grpc_byte_buffer** bp, bool* own_buffer) {
   *own_buffer = true;
   int byte_size = msg.ByteSize();
@@ -201,22 +198,23 @@ class SerializationTraits<T, typename std::enable_if<std::is_base_of<
     g_core_codegen_interface->grpc_slice_unref(slice);
     return g_core_codegen_interface->ok();
   } else {
-      internal::GrpcBufferWriter writer(
-          bp, internal::kGrpcBufferWriterMaxBufferLength);
+    BufferWriter writer(bp, internal::kGrpcBufferWriterMaxBufferLength);
     return msg.SerializeToZeroCopyStream(&writer)
                ? g_core_codegen_interface->ok()
                : Status(StatusCode::INTERNAL, "Failed to serialize message");
   }
 }
 
-  static Status Deserialize(grpc_byte_buffer* buffer,
+// BufferReader must be a subclass of io::ZeroCopyInputStream.
+template <class BufferReader, class T>
+Status GenericDeserialize(grpc_byte_buffer* buffer,
                           grpc::protobuf::Message* msg) {
   if (buffer == nullptr) {
     return Status(StatusCode::INTERNAL, "No payload");
   }
   Status result = g_core_codegen_interface->ok();
   {
-      internal::GrpcBufferReader reader(buffer);
+    BufferReader reader(buffer);
     if (!reader.status().ok()) {
       return reader.status();
     }
@@ -232,7 +230,32 @@ class SerializationTraits<T, typename std::enable_if<std::is_base_of<
   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
 

src/cpp/common/core_codegen.cc

@@ -116,6 +116,12 @@ grpc_byte_buffer* CoreCodegen::grpc_raw_byte_buffer_create(grpc_slice* slice,
   return ::grpc_raw_byte_buffer_create(slice, nslices);
 }
 
+grpc_slice CoreCodegen::grpc_slice_new_with_user_data(void* p, size_t len,
+                                                      void (*destroy)(void*),
+                                                      void* user_data) {
+  return ::grpc_slice_new_with_user_data(p, len, destroy, user_data);
+}
+
 grpc_slice CoreCodegen::grpc_empty_slice() { return ::grpc_empty_slice(); }
 
 grpc_slice CoreCodegen::grpc_slice_malloc(size_t length) {
@@ -126,10 +132,18 @@ void CoreCodegen::grpc_slice_unref(grpc_slice slice) {
   ::grpc_slice_unref(slice);
 }
 
+grpc_slice CoreCodegen::grpc_slice_ref(grpc_slice slice) {
+  return ::grpc_slice_ref(slice);
+}
+
 grpc_slice CoreCodegen::grpc_slice_split_tail(grpc_slice* s, size_t split) {
   return ::grpc_slice_split_tail(s, split);
 }
 
+grpc_slice CoreCodegen::grpc_slice_split_head(grpc_slice* s, size_t split) {
+  return ::grpc_slice_split_head(s, split);
+}
+
 grpc_slice CoreCodegen::grpc_slice_from_static_buffer(const void* buffer,
                                                       size_t length) {
   return ::grpc_slice_from_static_buffer(buffer, length);