Implementation:Alibaba MNN FlatBuffers gRPC Header

Knowledge Sources	Alibaba_MNN FlatBuffers
Domains	Serialization, RPC
Last Updated	2026-02-10 12:00 GMT

Overview

Integration header enabling FlatBuffers serialization as a message format within gRPC services.

Description

grpc.h provides the glue layer between FlatBuffers and gRPC. It defines grpc::MessageBuilder which extends FlatBufferBuilder with gRPC-compatible slice allocation, and grpc::Message<T> which wraps serialized FlatBuffers for transport over gRPC channels. This allows gRPC services to use FlatBuffers instead of Protocol Buffers as the wire format.

Usage

Vendored dependency used internally by MNN for model serialization. Not directly imported by end users.

Code Reference

Source Location

• Repository: Alibaba_MNN
• File: 3rd_party/flatbuffers/include/flatbuffers/grpc.h
• Lines: 1-328

Signature

namespace flatbuffers {
namespace grpc {
  class MessageBuilder;
  template<class T> class Message;
  class SliceAllocator;
}}

Import

#include "flatbuffers/grpc.h"

I/O Contract

Input	Output
FlatBuffer data constructed via MessageBuilder	grpc::Message<T> ready for gRPC transport
Incoming gRPC message	Zero-copy FlatBuffer root pointer

Usage Examples

#include "flatbuffers/grpc.h"

flatbuffers::grpc::MessageBuilder mb;
auto name = mb.CreateString("request");
// ... build table ...
mb.Finish(root_offset);

auto msg = mb.ReleaseMessage<MyRequest>();
// Send msg via gRPC stub

Related Pages

• Environment:Alibaba_MNN_CPU_Build_Environment