From 80efe0d5be02572578f84421f8581833058be582 Mon Sep 17 00:00:00 2001
From: lia <167905060+lia-viam@users.noreply.github.com>
Date: Mon, 23 Dec 2024 13:11:00 -0500
Subject: [PATCH] RSDK-9556 Forward declarations for grpc Client stuff (#341)

---
 CMakeLists.txt                                |  4 ++
 src/viam/sdk/CMakeLists.txt                   |  5 +-
 src/viam/sdk/common/client_helper.cpp         | 36 ++++++++++++
 src/viam/sdk/common/client_helper.hpp         | 34 +++++++++---
 src/viam/sdk/common/grpc_client_fwd.hpp.in    | 55 +++++++++++++++++++
 src/viam/sdk/common/utils.cpp                 | 32 -----------
 src/viam/sdk/common/utils.hpp                 | 24 --------
 src/viam/sdk/robot/client.cpp                 |  1 +
 .../sdk/services/private/mlmodel_client.cpp   |  2 +-
 9 files changed, 128 insertions(+), 65 deletions(-)
 create mode 100644 src/viam/sdk/common/grpc_client_fwd.hpp.in

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 78d0e9e05..b48d3fc25 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -430,6 +430,10 @@ if ((VIAMCPPSDK_GRPCXX_VERSION VERSION_GREATER 1.51.1) AND (VIAMCPPSDK_PROTOC_VE
   set(VIAMCPPSDK_BUF_REMOTE_PLUGIN_SUPPORTED 1)
 endif()
 
+if (VIAMCPPSDK_GRPCXX_VERSION VERSION_LESS 1.32.0)
+  set(VIAMCPPSDK_GRPCXX_LEGACY_CLIENT_FWD 1)
+endif()
+
 include(FetchContent)
 
 FetchContent_Declare(
diff --git a/src/viam/sdk/CMakeLists.txt b/src/viam/sdk/CMakeLists.txt
index fafeb316b..fe5982e1f 100644
--- a/src/viam/sdk/CMakeLists.txt
+++ b/src/viam/sdk/CMakeLists.txt
@@ -29,6 +29,8 @@ endif()
 message(WARNING "api proto label is ${VIAMCPPSDK_API_PROTO_LABEL}")
 configure_file(common/private/version_metadata.hpp.in common/private/version_metadata.hpp @ONLY)
 
+# Configure the grpc client forward declarations file
+configure_file(common/grpc_client_fwd.hpp.in common/grpc_client_fwd.hpp)
 
 # Set compile and link options based on arguments
 if (VIAMCPPSDK_USE_WALL_WERROR)
@@ -137,6 +139,7 @@ target_sources(viamsdk
   PUBLIC FILE_SET viamsdk_public_includes TYPE HEADERS
     BASE_DIRS
       ../..
+      ${CMAKE_CURRENT_BINARY_DIR}/../..
     FILES
       ../../viam/sdk/common/client_helper.hpp
       ../../viam/sdk/common/exception.hpp
@@ -189,6 +192,7 @@ target_sources(viamsdk
       ../../viam/sdk/spatialmath/geometry.hpp
       ../../viam/sdk/spatialmath/orientation.hpp
       ../../viam/sdk/spatialmath/orientation_types.hpp
+      ${CMAKE_CURRENT_BINARY_DIR}/../../viam/sdk/common/grpc_client_fwd.hpp
 )
 
 set_target_properties(
@@ -207,7 +211,6 @@ target_include_directories(viamsdk
     "$<INSTALL_INTERFACE:${VIAMCPPSDK_GRPC_INCLUDE_DIRS}>"
     "$<BUILD_INTERFACE:${VIAMCPPSDK_PROTOBUF_INCLUDE_DIRS}>"
     "$<INSTALL_INTERFACE:${VIAMCPPSDK_PROTOBUF_INCLUDE_DIRS}>"
-  PRIVATE
     "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/../..>"
 )
 
diff --git a/src/viam/sdk/common/client_helper.cpp b/src/viam/sdk/common/client_helper.cpp
index 84990153d..1d98249b6 100644
--- a/src/viam/sdk/common/client_helper.cpp
+++ b/src/viam/sdk/common/client_helper.cpp
@@ -2,8 +2,12 @@
 
 #include <cstdlib>
 
+#include <grpcpp/client_context.h>
+
 #include <boost/log/trivial.hpp>
 
+#include <viam/sdk/common/private/version_metadata.hpp>
+
 namespace viam {
 namespace sdk {
 
@@ -16,5 +20,37 @@ namespace client_helper_details {
 }
 
 }  // namespace client_helper_details
+
+ClientContext::ClientContext() : wrapped_context_(std::make_unique<GrpcClientContext>()) {
+    set_client_ctx_authority_();
+    add_viam_client_version_();
+}
+
+ClientContext::~ClientContext() = default;
+
+ClientContext::operator const GrpcClientContext*() const {
+    return wrapped_context_.get();
+}
+
+ClientContext::operator GrpcClientContext*() {
+    return wrapped_context_.get();
+}
+
+void ClientContext::try_cancel() {
+    wrapped_context_->TryCancel();
+}
+
+void ClientContext::set_debug_key(const std::string& debug_key) {
+    wrapped_context_->AddMetadata("dtname", debug_key);
+}
+
+void ClientContext::set_client_ctx_authority_() {
+    wrapped_context_->set_authority("viam-placeholder");
+}
+
+void ClientContext::add_viam_client_version_() {
+    wrapped_context_->AddMetadata("viam_client", impl::k_version);
+}
+
 }  // namespace sdk
 }  // namespace viam
diff --git a/src/viam/sdk/common/client_helper.hpp b/src/viam/sdk/common/client_helper.hpp
index c68e7fe85..27171c9e0 100644
--- a/src/viam/sdk/common/client_helper.hpp
+++ b/src/viam/sdk/common/client_helper.hpp
@@ -1,12 +1,9 @@
 #pragma once
 
-#include <grpcpp/client_context.h>
-#include <grpcpp/support/sync_stream.h>
-
 #include <viam/sdk/common/exception.hpp>
+#include <viam/sdk/common/grpc_client_fwd.hpp>
 #include <viam/sdk/common/private/utils.hpp>
 #include <viam/sdk/common/proto_value.hpp>
-#include <viam/sdk/common/utils.hpp>
 
 namespace grpc {
 
@@ -23,16 +20,39 @@ namespace client_helper_details {
 
 }  // namespace client_helper_details
 
+// the authority on a grpc::ClientContext is sometimes set to an invalid uri on mac, causing
+// `rust-utils` to fail to process gRPC requests. This class provides a convenience wrapper around a
+// grpc ClientContext that allows us to make any necessary modifications to authority or else where
+// to avoid runtime issues.
+// For more details, see https://viam.atlassian.net/browse/RSDK-5194.
+class ClientContext {
+   public:
+    ClientContext();
+    ~ClientContext();
+
+    void try_cancel();
+
+    operator GrpcClientContext*();
+    operator const GrpcClientContext*() const;
+
+    void set_debug_key(const std::string& debug_key);
+
+   private:
+    void set_client_ctx_authority_();
+    void add_viam_client_version_();
+    std::unique_ptr<GrpcClientContext> wrapped_context_;
+};
+
 // Method type for a gRPC call that returns a response message type.
 template <typename StubType, typename RequestType, typename ResponseType>
-using SyncMethodType = ::grpc::Status (StubType::*)(::grpc::ClientContext*,
+using SyncMethodType = ::grpc::Status (StubType::*)(GrpcClientContext*,
                                                     const RequestType&,
                                                     ResponseType*);
 
 // Method type for a gRPC call that returns a stream of response message type.
 template <typename StubType, typename RequestType, typename ResponseType>
-using StreamingMethodType = std::unique_ptr<::grpc::ClientReaderInterface<ResponseType>> (
-    StubType::*)(::grpc::ClientContext*, const RequestType&);
+using StreamingMethodType = std::unique_ptr<GrpcClientReaderInterface<ResponseType>> (StubType::*)(
+    GrpcClientContext*, const RequestType&);
 
 template <typename ClientType,
           typename StubType,
diff --git a/src/viam/sdk/common/grpc_client_fwd.hpp.in b/src/viam/sdk/common/grpc_client_fwd.hpp.in
new file mode 100644
index 000000000..e6ba5799f
--- /dev/null
+++ b/src/viam/sdk/common/grpc_client_fwd.hpp.in
@@ -0,0 +1,55 @@
+#pragma once
+
+#cmakedefine VIAMCPPSDK_GRPCXX_LEGACY_CLIENT_FWD
+
+#ifndef VIAMCPPSDK_GRPCXX_LEGACY_CLIENT_FWD
+
+// Forward declaration file for grpc ClientContext and ClientReaderInterface<T>.
+// This file provides includes for recent (>= 1.32.0) versions of grpc.
+
+namespace grpc {
+
+class ClientContext;
+
+template <typename>
+class ClientReaderInterface;
+
+}  // namespace grpc
+
+namespace viam {
+namespace sdk {
+
+using GrpcClientContext = ::grpc::ClientContext;
+
+template <typename T>
+using GrpcClientReaderInterface = ::grpc::ClientReaderInterface<T>;
+
+}  // namespace sdk
+}  // namespace viam
+
+#else
+
+// Forward declaration file for grpc ClientContext and ClientReaderInterface<T>.
+// This file provides includes for the oldest supported versions of grpc (< 1.32.0).
+
+namespace grpc_impl {
+
+class ClientContext;
+
+template <typename>
+class ClientReaderInterface;
+
+}  // namespace grpc_impl
+
+namespace viam {
+namespace sdk {
+
+using GrpcClientContext = ::grpc_impl::ClientContext;
+
+template <typename T>
+using GrpcClientReaderInterface = ::grpc_impl::ClientReaderInterface<T>;
+
+}  // namespace sdk
+}  // namespace viam
+
+#endif
diff --git a/src/viam/sdk/common/utils.cpp b/src/viam/sdk/common/utils.cpp
index fdd03b6da..d6375cbde 100644
--- a/src/viam/sdk/common/utils.cpp
+++ b/src/viam/sdk/common/utils.cpp
@@ -18,7 +18,6 @@
 #include <viam/api/common/v1/common.pb.h>
 
 #include <viam/sdk/common/private/utils.hpp>
-#include <viam/sdk/common/private/version_metadata.hpp>
 #include <viam/sdk/components/component.hpp>
 #include <viam/sdk/registry/registry.hpp>
 
@@ -151,37 +150,6 @@ ProtoStruct with_debug_entry(ProtoStruct&& map) {
     return map;
 }
 
-ClientContext::ClientContext() : wrapped_context_(std::make_unique<grpc::ClientContext>()) {
-    set_client_ctx_authority_();
-    add_viam_client_version_();
-}
-
-ClientContext::~ClientContext() = default;
-
-ClientContext::operator const grpc::ClientContext*() const {
-    return wrapped_context_.get();
-}
-
-ClientContext::operator grpc::ClientContext*() {
-    return wrapped_context_.get();
-}
-
-void ClientContext::try_cancel() {
-    wrapped_context_->TryCancel();
-}
-
-void ClientContext::set_debug_key(const std::string& debug_key) {
-    wrapped_context_->AddMetadata("dtname", debug_key);
-}
-
-void ClientContext::set_client_ctx_authority_() {
-    wrapped_context_->set_authority("viam-placeholder");
-}
-
-void ClientContext::add_viam_client_version_() {
-    wrapped_context_->AddMetadata("viam_client", impl::k_version);
-}
-
 bool from_dm_from_extra(const ProtoStruct& extra) {
     auto pos = extra.find("fromDataManagement");
     if (pos != extra.end()) {
diff --git a/src/viam/sdk/common/utils.hpp b/src/viam/sdk/common/utils.hpp
index cb3c76532..f47442750 100644
--- a/src/viam/sdk/common/utils.hpp
+++ b/src/viam/sdk/common/utils.hpp
@@ -3,7 +3,6 @@
 #include <memory>
 
 #include <boost/optional/optional.hpp>
-#include <grpcpp/client_context.h>
 
 #include <viam/sdk/common/proto_value.hpp>
 #include <viam/sdk/components/component.hpp>
@@ -82,29 +81,6 @@ struct from_proto<common::v1::ResponseMetadata> {
 std::vector<unsigned char> string_to_bytes(std::string const& s);
 std::string bytes_to_string(std::vector<unsigned char> const& b);
 
-// the authority on a grpc::ClientContext is sometimes set to an invalid uri on mac, causing
-// `rust-utils` to fail to process gRPC requests. This class provides a convenience wrapper around a
-// grpc ClientContext that allows us to make any necessary modifications to authority or else where
-// to avoid runtime issues.
-// For more details, see https://viam.atlassian.net/browse/RSDK-5194.
-class ClientContext {
-   public:
-    ClientContext();
-    ~ClientContext();
-
-    void try_cancel();
-
-    operator grpc::ClientContext*();
-    operator const grpc::ClientContext*() const;
-
-    void set_debug_key(const std::string& debug_key);
-
-   private:
-    void set_client_ctx_authority_();
-    void add_viam_client_version_();
-    std::unique_ptr<grpc::ClientContext> wrapped_context_;
-};
-
 /// @brief Given a fully qualified resource name, returns remote name (or "" if no remote name
 /// exists) and short name
 std::pair<std::string, std::string> long_name_to_remote_and_short(const std::string& long_name);
diff --git a/src/viam/sdk/robot/client.cpp b/src/viam/sdk/robot/client.cpp
index 3fe5d4d1f..f0befb2d9 100644
--- a/src/viam/sdk/robot/client.cpp
+++ b/src/viam/sdk/robot/client.cpp
@@ -19,6 +19,7 @@
 #include <viam/api/robot/v1/robot.grpc.pb.h>
 #include <viam/api/robot/v1/robot.pb.h>
 
+#include <viam/sdk/common/client_helper.hpp>
 #include <viam/sdk/common/private/repeated_ptr_convert.hpp>
 #include <viam/sdk/common/proto_value.hpp>
 #include <viam/sdk/common/utils.hpp>
diff --git a/src/viam/sdk/services/private/mlmodel_client.cpp b/src/viam/sdk/services/private/mlmodel_client.cpp
index 8b7fd6039..2c98960dd 100644
--- a/src/viam/sdk/services/private/mlmodel_client.cpp
+++ b/src/viam/sdk/services/private/mlmodel_client.cpp
@@ -16,7 +16,7 @@
 
 #include <grpcpp/channel.h>
 
-#include <viam/sdk/common/utils.hpp>
+#include <viam/sdk/common/client_helper.hpp>
 #include <viam/sdk/services/private/mlmodel.hpp>
 
 #include <viam/sdk/common/exception.hpp>