grpc-native: Support client calls on native (#452)

* grpc-native: Initial client setup

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Working CompletionQueue

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Working version of NativeClientCall

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Working rewrite state

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Add callback future

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Refactor to use callbacks instead of coroutines

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Fixes after rebase

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Implement bridge to common

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Remove unnecessary C header definitions

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Rename grpcpp_c to kgrpc

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Reduce library dependencies (fixes KRPC-185)

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Write docs

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Address PR comments

Signed-off-by: Johannes Zottele <[email protected]>

* grpc-native: Address PR comments

Signed-off-by: Johannes Zottele <[email protected]>

---------

Signed-off-by: Johannes Zottele <[email protected]>

Author: Jozott00

cinterop-c/BUILD.bazel

@@ -1,34 +1,21 @@
 load("@rules_cc//cc:defs.bzl", "cc_library")
 
-cc_binary(
-    name = "testdemo",
-    srcs = ["src/main.cpp"],
-    deps = [
-        ":protowire",
-    ],
-)
-
 cc_static_library(
-    name = "grpcpp_c_static",
+    name = "kgrpc_static",
     deps = [
-        ":grpcpp_c",
+        ":kgrpc",
     ],
 )
 
 cc_library(
-    name = "grpcpp_c",
-    srcs = ["src/grpcpp_c.cpp"],
-    hdrs = glob(["include/**/*.h"]),
+    name = "kgrpc",
+    srcs = ["src/kgrpc.cpp"],
+    hdrs = glob(["include/kgrpc.h"]),
     copts = ["-std=c++20"],
     includes = ["include"],
     visibility = ["//visibility:public"],
     deps = [
-        # TODO: Reduce the dependencies and only use required once. KRPC-185
-        "@com_github_grpc_grpc//:channelz",
-        "@com_github_grpc_grpc//:generic_stub",
-        "@com_github_grpc_grpc//:grpc++",
-        "@com_github_grpc_grpc//:grpc_credentials_util",
-        "@com_google_protobuf//:protobuf",
+        "@com_github_grpc_grpc//:grpc"
     ],
 )
 
@@ -42,7 +29,7 @@ cc_static_library(
 cc_library(
     name = "protowire",
     srcs = ["src/protowire.cpp"],
-    hdrs = glob(["include/*.h"]),
+    hdrs = glob(["include/protowire.h"]),
     copts = ["-std=c++20"],
     includes = ["include"],
     visibility = ["//visibility:public"],

cinterop-c/MODULE.bazel

@@ -1,5 +1,5 @@
 module(
-    name = "grpcpp_c",
+    name = "kgrpc",
     version = "0.1",
 )
 
@@ -16,7 +16,7 @@ bazel_dep(
     repo_name = "com_google_protobuf",
 )
 
-# gRPC C++ library
+# gRPC library
 bazel_dep(
     name = "grpc",
     version = "1.73.1",

cinterop-c/include/grpcpp_c.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+/*
+ * Helper functions required for gRPC Core cinterop.
+ */
+
+#ifndef GRPCPP_C_H
+#define GRPCPP_C_H
+
+#include <stdbool.h>
+#include <grpc/grpc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Struct that layouts a grpc_completion_queue_functor and user opaque data pointer,
+ * to implement the callback mechanism in the K/N CompletionQueue.
+ */
+typedef struct {
+    grpc_completion_queue_functor functor;
+    void *user_data;
+} kgrpc_cb_tag;
+
+/*
+ * Call to grpc_iomgr_run_in_background(), which is not exposed as extern "C" and therefore must be wrapped.
+ */
+bool kgrpc_iomgr_run_in_background();
+
+#ifdef __cplusplus
+    }
+#endif
+
+#endif //GRPCPP_C_H

cinterop-c/include/kgrpc.h

@@ -1,3 +1,7 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
 #ifndef PROTOWIRE_H
 #define PROTOWIRE_H
 

cinterop-c/include/protowire.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+#include <kgrpc.h>
+
+#include "src/core/lib/iomgr/iomgr.h"
+
+extern "C" {
+
+    bool kgrpc_iomgr_run_in_background() {
+        return grpc_iomgr_run_in_background();
+    }
+
+}
+
+