Singleton configuration reader

CMakeLists.txt

@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.15)
-project(TextReader LANGUAGES CXX)
+cmake_minimum_required(VERSION 3.19)
+project(BodyPipeline LANGUAGES CXX)
 
 # Set C++ standard and enable modern practices
 set(CMAKE_CXX_STANDARD 17)
@@ -66,12 +66,15 @@ include_directories(${PROJECT_SOURCE_DIR}/sink_manager.hpp)
 include_directories(${PROJECT_SOURCE_DIR}/message_handling.hpp)
 include_directories(${PROJECT_SOURCE_DIR}/rtsp_streaming_manager.hpp)
 include_directories(${PROJECT_SOURCE_DIR}/metrics_manager.hpp)
+include_directories(${PROJECT_SOURCE_DIR}/config_manager.hpp)
+
+
 
 set(SOURCES src/main.cpp  src/camera_manager.cpp src/pipeline_manager.cpp src/streammux_manager.cpp 
             src/source_bin.cpp src/gstds_example_manager.cpp src/tiler_manager.cpp
             src/nv_video_convert_manager.cpp src/nv_osd_manager.cpp src/queue_manager.cpp 
             src/nv_ds_logger_manager.cpp src/sink_manager.cpp src/message_handling.cpp
-            src/rtsp_streaming_manager.cpp src/metrics_manager.cpp)
+            src/rtsp_streaming_manager.cpp src/metrics_manager.cpp src/config_manager.cpp)
 # Create the executable
 add_executable(${PROJECT_NAME}  ${SOURCES})
 

src/config_manager.cpp

@@ -0,0 +1,16 @@
+#include "config_manager.hpp"
+
+ConfigManager::ConfigManager() {
+    std::ifstream file("../data/configuration.json");
+    if (!file) {
+        throw std::runtime_error("Could not open configuration.json");
+    }
+    file >> config;
+}
+
+ConfigManager& ConfigManager::get_instance() {
+    static ConfigManager instance;
+    return instance;
+}
+
+const nlohmann::json& ConfigManager::get_config() const { return config; }

src/config_manager.hpp

@@ -0,0 +1,19 @@
+#pragma once
+#include <fstream>
+#include <nlohmann/json.hpp>
+#include <stdexcept>
+#include <string>
+
+class ConfigManager {
+   public:
+    static ConfigManager& get_instance();
+
+    const nlohmann::json& get_config() const;
+
+   private:
+    ConfigManager();  // constructor loads the JSON file
+    ConfigManager(const ConfigManager&) = delete;
+    ConfigManager& operator=(const ConfigManager&) = delete;
+
+    nlohmann::json config;
+};

src/rtsp_streaming_manager.cpp

@@ -4,8 +4,6 @@
     g_object_set(G_OBJECT(object), "gpu-id", gpu_id, NULL);
 #define GPU_ID 0
 
-using json = nlohmann::json;
-
 GstRTSPServer *RtspStreamingManager::server;
 std::string RtspStreamingManager::codec_rtsp_out = "";
 std::string RtspStreamingManager::mount_address = "";
@@ -16,19 +14,17 @@ guint RtspStreamingManager::updsink_port_num = 1;
 guint RtspStreamingManager::payload = 1;
 
 RtspStreamingManager::RtspStreamingManager() {
-    json j;
-    std::ifstream i("../data/configuration.json");
-    i >> j;
+    const auto &config = ConfigManager::get_instance().get_config();
 
-    j.at("codec_rtsp_out").get_to(codec_rtsp_out);
-    j.at("mount_address").get_to(mount_address);
-    j.at("udp_buffer_size").get_to(udp_buffer_size);
-    j.at("clock_rate").get_to(clock_rate);
-    j.at("bitrate").get_to(bitrate);
-    j.at("rtsp_port").get_to(rtsp_port);
-    j.at("updsink_port_num").get_to(updsink_port_num);
-    j.at("payload").get_to(payload);
-    j.at("host").get_to(host);
+    config.at("codec_rtsp_out").get_to(codec_rtsp_out);
+    config.at("mount_address").get_to(mount_address);
+    config.at("udp_buffer_size").get_to(udp_buffer_size);
+    config.at("clock_rate").get_to(clock_rate);
+    config.at("bitrate").get_to(bitrate);
+    config.at("rtsp_port").get_to(rtsp_port);
+    config.at("updsink_port_num").get_to(updsink_port_num);
+    config.at("payload").get_to(payload);
+    config.at("host").get_to(host);
 }
 
 gboolean RtspStreamingManager::start_rtsp_streaming() {

src/rtsp_streaming_manager.hpp

@@ -3,10 +3,9 @@
 #include <gst/rtsp-server/rtsp-server.h>
 
 #include <fstream>
-#include <nlohmann/json.hpp>
 
+#include "config_manager.hpp"
 #include "cuda_runtime_api.h"
-#include "json.hpp"
 
 class RtspStreamingManager {
    private:

src/sink_manager.cpp

@@ -4,15 +4,11 @@
     g_object_set(G_OBJECT(object), "gpu-id", gpu_id, NULL);
 #define GPU_ID 0
 
-using json = nlohmann::json;
-
 SinkManager::SinkManager() {
-    json j;
-    std::ifstream i("../data/configuration.json");
-    i >> j;
-    j.at("output_video_path").get_to(output_video_path);
-    j.at("display_output").get_to(display_output);
-    j.at("codec_rtsp_out").get_to(codec_rtsp_out);
+    const auto& config = ConfigManager::get_instance().get_config();
+    config.at("output_video_path").get_to(output_video_path);
+    config.at("display_output").get_to(display_output);
+    config.at("codec_rtsp_out").get_to(codec_rtsp_out);
 }
 
 bool SinkManager::create_sink(cudaDeviceProp prop) {

src/sink_manager.hpp

@@ -2,10 +2,9 @@
 #include <gst/gst.h>
 
 #include <fstream>
-#include <nlohmann/json.hpp>
 
+#include "config_manager.hpp"
 #include "cuda_runtime_api.h"
-#include "json.hpp"
 
 class SinkManager {
    private:

src/streammux_manager.cpp

@@ -5,15 +5,11 @@
 #define GPU_ID 0
 #define MUXER_BATCH_TIMEOUT_USEC 40000
 
-using json = nlohmann::json;
-
 StreammuxManager::StreammuxManager() {
-    json j;
-    std::ifstream i("../data/configuration.json");
-    i >> j;
+    const auto& config = ConfigManager::get_instance().get_config();
 
-    MUXER_OUTPUT_HEIGHT = j["MUXER_OUTPUT_HEIGHT"];
-    MUXER_OUTPUT_WIDTH = j["MUXER_OUTPUT_WIDTH"];
+    MUXER_OUTPUT_HEIGHT = config["MUXER_OUTPUT_HEIGHT"];
+    MUXER_OUTPUT_WIDTH = config["MUXER_OUTPUT_WIDTH"];
 }
 
 bool StreammuxManager::create_streammux(int num_sources) {

src/streammux_manager.hpp

@@ -2,13 +2,11 @@
 
 #include <fstream>
 #include <iostream>
-#include <nlohmann/json.hpp>
 
-#include "json.hpp"
+#include "config_manager.hpp"
 
 class StreammuxManager {
    private:
-
    public:
     GstElement *streammux = NULL;
     int MUXER_OUTPUT_WIDTH;