feat(node-gateway): Add gateway node type

Author: JitpanuM

CMakeLists.txt

@@ -80,6 +80,8 @@ find_package(Criterion)
 find_package(OpalOrchestra)
 find_package(LibXml2)
 find_package(OpalAsyncApi)
+find_package(Protobuf)
+find_package(gRPC)
 
 # Check for tools
 find_program(PROTOBUFC_COMPILER NAMES protoc-c)
@@ -214,6 +216,7 @@ cmake_dependent_option(WITH_NODE_ULDAQ          "Build with uldaq node-type"
 cmake_dependent_option(WITH_NODE_WEBRTC         "Build with webrtc node-type"                           "${WITH_DEFAULTS}" "WITH_WEB; LibDataChannel_FOUND" OFF)
 cmake_dependent_option(WITH_NODE_WEBSOCKET      "Build with websocket node-type"                        "${WITH_DEFAULTS}" "WITH_WEB" OFF)
 cmake_dependent_option(WITH_NODE_ZEROMQ         "Build with zeromq node-type"                           "${WITH_DEFAULTS}" "LIBZMQ_FOUND; NOT WITHOUT_GPL" OFF)
+cmake_dependent_option(WITH_GRPC                "Build with grpc api"                                   "${WITH_DEFAULTS}" "gRPC_FOUND" OFF)
 
 # Set a default for the build type
 if("${CMAKE_BUILD_TYPE}" STREQUAL "")

include/villas/api/requests/gateway.hpp

@@ -0,0 +1,34 @@
+/* Universal Data-exchange API request.
+ *
+ * Author: Steffen Vogel <post@steffenvogel.de>
+ * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <villas/api/requests/node.hpp>
+#include <villas/nodes/gateway.hpp>
+
+namespace villas {
+namespace node {
+
+// Forward declarations
+class Node;
+
+namespace api {
+
+class GatewayRequest : public NodeRequest {
+
+protected:
+  GatewayNode *gateway_node;
+
+public:
+  using NodeRequest::NodeRequest;
+
+  void prepare() override;
+};
+
+} // namespace api
+} // namespace node
+} // namespace villas

include/villas/nodes/gateway.hpp

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <pthread.h>
+
+#include <villas/node.hpp>
+#include <villas/format.hpp>
+
+namespace villas {
+namespace node {
+
+// Forward declarations
+struct Sample;
+
+class GatewayNode : public Node {
+protected:
+  int parse(json_t *json) override;
+
+  int _read(struct Sample *smps[], unsigned cnt) override;
+  int _write(struct Sample *smps[], unsigned cnt) override;
+
+public:
+  GatewayNode(const uuid_t &id = {}, const std::string &name = "");
+  enum ApiType { gRPC };
+
+  struct Direction {
+    Sample *sample;
+    pthread_cond_t cv;
+    pthread_mutex_t mutex;
+    char* buf;
+    size_t buflen;
+    size_t wbytes;
+  };
+
+
+  Direction read, write;
+  std::string address;
+  ApiType type;
+
+  Format *formatter;
+
+  char *buf;
+  size_t buflen;
+  size_t wbytes;
+
+  int prepare() override;
+
+  int check() override;
+
+  int start() override;
+
+  int stop() override;
+
+  ~GatewayNode();
+};
+
+} // namespace node
+} // namespace villas

lib/api/CMakeLists.txt

@@ -42,6 +42,20 @@ if(WITH_GRAPHVIZ)
     list(APPEND LIBRARIES PkgConfig::CGRAPH PkgConfig::GVC)
 endif()
 
+if (WITH_GRPC)
+    find_path(REFLECTION_INCLUDE_DIR
+        NAMES grpc/reflection/v1alpha/reflection.pb.cc
+    )
+    if (REFLECTION_INCLUDE_DIR)
+        list(APPEND API_SRC
+            requests/gateway/grpc.cpp
+            ${REFLECTION_INCLUDE_DIR}/grpc/reflection/v1alpha/reflection.pb.cc
+            ${REFLECTION_INCLUDE_DIR}/grpc/reflection/v1alpha/reflection.grpc.pb.cc
+        )
+        list(APPEND LIBRARIES protobuf::libprotobuf gRPC::grpc++)
+    endif()
+endif()
+
 add_library(api STATIC ${API_SRC})
 target_include_directories(api PUBLIC ${INCLUDE_DIRS})
 target_link_libraries(api PUBLIC ${LIBRARIES})