Add new exception when file not found

pythonApi/grib_to_arrow.cpp

@@ -1,5 +1,6 @@
 #include "../src/gribreader.hpp"
 #include "../src/gribmessage.hpp"
+#include "../src/exceptions/notsuchfileexception.hpp"
 
 //#define USE_CMAKE
 
@@ -24,6 +25,8 @@ namespace py = pybind11;
 using namespace std;
 PYBIND11_MODULE(gribtoarrow, m)
 {
+
+ py::register_exception<NoSuchFileException>(m, "NoSuchFileException");
  arrow::py::import_pyarrow();
  py::class_<GribReader>(m, "GribReader")
  .def(py::init<string>(), pybind11::call_guard<pybind11::gil_scoped_release>(), R"EOL(

src/exceptions/notsuchfileexception.hpp

@@ -0,0 +1,22 @@
+#include <exception>
+#include <string>
+
+using namespace std;
+
+class NoSuchFileException : public std::exception {
+
+ public:
+
+ NoSuchFileException(string filepath) : filepath(filepath) {
+ std::string errType = "Unable to find file ";
+ errMsg = (errType + filepath).c_str();
+ };
+
+ const char* what() const noexcept {
+ return errMsg;
+ }
+
+ private:
+ std::string filepath;
+ const char* errMsg;
+};

src/gribreader.cpp

@@ -24,6 +24,7 @@
 #include "gribmessageiterator.hpp"
 #include "caster.hpp"
 #include "converter.hpp"
+#include "exceptions/notsuchfileexception.hpp"
 
 using namespace std;
 namespace cp = arrow::compute;
@@ -37,6 +38,7 @@ GribReader::GribReader(string filepath) : filepath(filepath) {
  -999l);
  fin = fopen(filepath.c_str(), "rb");
  if (!fin) {
+ throw NoSuchFileException(filepath);
  cout << "Error: unable to open input file" << filepath << endl;
  } else {
  cout << "I'm ready file is " << fin << endl;