Merge pull request #2161 from lewisgross1296/delete_tally

Add extern function to delete a tally by its index in the tallies vector

docs/source/capi/index.rst

@@ -460,6 +460,13 @@ Functions
    :return: Return status (negative if an error occurs)
    :rtype: int
 
+.. c:function:: int openmc_remove_tally(int32_t index);
+
+   Given an index of a tally, remove it from the tallies array
+   :param int index: Index in tallies array
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
 .. c:function:: int openmc_run()
 
    Run a simulation

include/openmc/capi.h

@@ -118,6 +118,7 @@ int openmc_regular_mesh_get_params(
 int openmc_regular_mesh_set_dimension(int32_t index, int n, const int* dims);
 int openmc_regular_mesh_set_params(int32_t index, int n, const double* ll,
   const double* ur, const double* width);
+int openmc_remove_tally(int32_t index);
 int openmc_reset();
 int openmc_reset_timers();
 int openmc_run();

include/openmc/tallies/tally.h

@@ -47,9 +47,11 @@ class Tally {
 
   void set_nuclides(const vector<std::string>& nuclides);
 
-  const vector<int32_t>& filters() const { return filters_; }
+  //! returns vector of indices corresponding to the tally this is called on
+  const vector<int32_t>& filters() const { return filters_; } 
 
-  int32_t filters(int i) const { return filters_[i]; }
+  //! \brief Returns the tally filter at index i
+  int32_t filters(int i) const { return filters_[i]; } 
 
   void set_filters(gsl::span<Filter*> filters);
 

openmc/lib/tally.py

@@ -87,6 +87,9 @@
 _dll.openmc_tally_set_writable.argtypes = [c_int32, c_bool]
 _dll.openmc_tally_set_writable.restype = c_int
 _dll.openmc_tally_set_writable.errcheck = _error_handler
+_dll.openmc_remove_tally.argtypes = [c_int32]
+_dll.openmc_remove_tally.restype = c_int
+_dll.openmc_remove_tally.errcheck = _error_handler
 _dll.tallies_size.restype = c_size_t
 
 
@@ -405,4 +408,8 @@ def __len__(self):
     def __repr__(self):
         return repr(dict(self))
 
+    def __delitem__(self, key):
+        """Delete a tally from tally vector and remove the ID,index pair from tally"""
+        _dll.openmc_remove_tally(self[key]._index)
+
 tallies = _TallyMapping()

src/tallies/tally.cpp

@@ -46,6 +46,7 @@ namespace openmc {
 //==============================================================================
 
 namespace model {
+//! a mapping of tally ID to index in the tallies vector
 std::unordered_map<int, int> tally_map;
 vector<unique_ptr<Tally>> tallies;
 vector<int> active_tallies;
@@ -1271,4 +1272,20 @@ extern "C" size_t tallies_size()
   return model::tallies.size();
 }
 
+// given a tally ID, remove it from the tallies vector
+extern "C" int openmc_remove_tally(int32_t index)
+{
+  // check that id is in the map
+  if (index < 0 || index > model::tallies.size()) {
+    return OPENMC_E_OUT_OF_BOUNDS;
+  }
+  // grab tally so it's ID can be obtained to remove the (ID,index) pair from tally_map
+  auto& tally = model::tallies[index];
+  // delete the tally via iterator pointing to correct position
+  // this calls the Tally destructor, removing the tally from the map as well
+  model::tallies.erase(model::tallies.begin() + index);
+
+  return 0;
+}
+
 } // namespace openmc

tests/unit_tests/test_lib.py

@@ -340,6 +340,20 @@ def test_new_tally(lib_init):
     assert len(openmc.lib.tallies) == 5
 
 
+def test_delete_tally(lib_init):
+    # delete tally 10 which was added in the above test
+    # check length is one less than before
+    del openmc.lib.tallies[10]
+    assert len(openmc.lib.tallies) == 4
+
+
+def test_invalid_tally_id(lib_init):
+    # attempt to access a tally that is guaranteed not to have a valid index
+    max_id = max(openmc.lib.tallies.keys())
+    with pytest.raises(KeyError):
+        openmc.lib.tallies[max_id+1]
+
+
 def test_tally_activate(lib_simulation_init):
     t = openmc.lib.tallies[1]
     assert not t.active

tests/unit_tests/test_tallies.py

@@ -38,4 +38,4 @@ def test_xml_roundtrip(run_in_tmpdir):
     assert len(new_tally.triggers) == 1
     assert new_tally.triggers[0].trigger_type == tally.triggers[0].trigger_type
     assert new_tally.triggers[0].threshold == tally.triggers[0].threshold
-    assert new_tally.triggers[0].scores == tally.triggers[0].scores
+    assert new_tally.triggers[0].scores == tally.triggers[0].scores