sync() after write to avoid losing file data on power off.

PiPedalCommon/src/CMakeLists.txt

@@ -41,6 +41,7 @@ message(STATUS "NMPIPEDAL CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
 
 # Use the sdbus-c++ target in SDBusCpp namespace
 add_library(PiPedalCommon STATIC
+  ofstream_synced.cpp include/ofstream_synced.hpp
   ConfigSerializer.cpp include/ConfigSerializer.hpp
   WifiRegs.cpp include/WifiRegs.hpp
   WifiRegulations.cpp include/WifiRegulations.hpp

PiPedalCommon/src/ServiceConfiguration.cpp

@@ -30,6 +30,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <tuple>
+#include "ofstream_synced.hpp"
 
 using namespace pipedal;
 
@@ -65,7 +66,7 @@ void ServiceConfiguration::Save()
         std::filesystem::create_directories(directory);
 
         // make sure the file has correct permissions.
-        std::ofstream t;
+        pipedal::ofstream_synced t;
         t.open(filename);
         t.close();
 

PiPedalCommon/src/WriteTemplateFile.cpp

@@ -21,6 +21,7 @@
 #include "WriteTemplateFile.hpp"
 #include <fstream>
 #include <stdexcept>
+#include "ofstream_synced.hpp"
 
 using namespace pipedal;
 
@@ -37,7 +38,7 @@ void pipedal::WriteTemplateFile(
     const std::filesystem::path &inputFile,
     const std::filesystem::path &outputFile)
 {
-    std::ofstream out(outputFile);
+    pipedal::ofstream_synced out(outputFile);
     std::ifstream in(inputFile);
 
     if (!in.is_open())

PiPedalCommon/src/include/ConfigSerializer.hpp

@@ -30,6 +30,7 @@
 #include "autoptr_vector.h"
 #include <unordered_map>
 #include <fstream>
+#include "ofstream_synced.hpp"
 
 namespace config_serializer
 {
@@ -256,7 +257,7 @@ namespace config_serializer
         }
         void Save(const std::string &path)
         {
-            std::ofstream f;
+            pipedal::ofstream_synced f;
             f.open(path);
             if (!f.is_open())
             {

PiPedalCommon/src/include/ofstream_synced.hpp

@@ -0,0 +1,26 @@
+
+#pragma once
+
+#include <fstream>
+
+namespace pipedal
+{
+    void FileSystemSync();
+
+    class ofstream_synced : public std::ofstream
+    {
+    public:
+        ofstream_synced() {}
+
+        explicit ofstream_synced(const std::string &filename, ios_base::openmode mode = ios_base::out)
+            : std::ofstream(filename, mode)
+        {
+        }
+        explicit ofstream_synced(const char *filename, ios_base::openmode mode = ios_base::out)
+            : std::ofstream(filename, mode)
+        {
+        }
+        ~ofstream_synced();
+    };
+
+}

PiPedalCommon/src/ofstream_synced.cpp

@@ -0,0 +1,19 @@
+#include "ofstream_synced.hpp"
+#include "unistd.h"
+
+using namespace pipedal;
+
+
+void pipedal::FileSystemSync()
+{
+    ::sync();
+}
+
+ofstream_synced::~ofstream_synced()
+{
+    if (is_open())
+    {
+        close();
+        ::sync();
+    }
+}