issue with repeatable iterator but only on OSX

src/gribreader.cpp

@@ -273,18 +273,24 @@ optional<function<arrow::Result<shared_ptr<arrow::Array>>(shared_ptr<arrow::Arra
 }
 
 Iterator GribReader::begin() { 
- std::cout << "Creating iterator" << endl;
- codes_handle* h = codes_handle_new_from_file(0, fin, PRODUCT_GRIB, &err);
- auto m = new GribMessage(this, h, 0l);
- return Iterator(this, m, m_endMessage);
+ if(isRepeatable) {
+ fseek(fin, 0, SEEK_SET);
+ }
+ if (!isExhausted || isRepeatable) {
+ std::cout << "Creating iterator" << endl;
+ codes_handle* h = codes_handle_new_from_file(0, fin, PRODUCT_GRIB, &err);
+ auto m = new GribMessage(this, h, 0l);
+ return Iterator(this, m, m_endMessage);
+ } else {
+ std::cout << "Iterator is exhausted returning end_message" << endl;
+ return Iterator( this, m_endMessage, m_endMessage );
+ }
 }
 
 Iterator GribReader::end() {
 
- if (isRepeatable) {
- std::cout << "At end of message and is repeatable" << endl;
- fseek(fin, 0, SEEK_SET);
- }
+ isExhausted = true;
+ std::cout << "At end of message and is not repeatable" << endl;
  return Iterator( this, m_endMessage, m_endMessage );
 
 } 

src/gribreader.hpp

@@ -51,6 +51,7 @@ class GribReader
  string filepath;
  int err = 0;
  bool isRepeatable = false;
+ bool isExhausted = false;
  std::shared_ptr<arrow::Table> shared_locations;
  arrow::Table* conversions = NULLPTR;
  std::unordered_map<GridArea, std::shared_ptr<arrow::Table>> locations_in_area;

tests/test_iteration.py

@@ -16,18 +16,16 @@ def test_iterate_once(self, resource):
  reader = GribReader(str(resource) + "/meps_weatherapi_sorlandet.grb")
 
  cnt = self.get_iterator_count(reader)
- assert cnt == 269
+ assert cnt == 268
  cnt = self.get_iterator_count(reader)
  assert cnt == 0
 
- def test_iterate_once(self, resource):
+ def test_iterate_repeatable(self, resource):
  from gribtoarrow import GribReader
 
  reader = GribReader(str(resource) + "/meps_weatherapi_sorlandet.grb").withRepeatableIterator(True)
-
- it = iter(reader)
 
  cnt = self.get_iterator_count(reader)
- assert cnt == 269
+ assert cnt == 268
  cnt = self.get_iterator_count(reader)
- assert cnt == 269
+ assert cnt == 268