From f4480c60ce1b30d766c98ca5520d99d9ddf9456e Mon Sep 17 00:00:00 2001
From: Jurgen Lentz <jurgenlentz26@gmail.com>
Date: Fri, 18 Oct 2024 15:24:33 +0200
Subject: [PATCH] fix memory leaks

---
 amplpy/ampl.pyx      |  4 +++-
 amplpy/dataframe.pxi |  1 -
 amplpy/entity.pxi    | 11 +++++++++++
 amplpy/parameter.pxi |  9 +++++++--
 amplpy/util.pxi      |  4 +++-
 5 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/amplpy/ampl.pyx b/amplpy/ampl.pyx
index 40c525a..52aa118 100644
--- a/amplpy/ampl.pyx
+++ b/amplpy/ampl.pyx
@@ -515,7 +515,9 @@ cdef class AMPL:
         """
         cdef campl.AMPL_VARIANT* v
         PY_AMPL_CALL(campl.AMPL_GetValue(self._c_ampl, scalar_expression.encode('utf-8'), &v))
-        return to_py_variant(v)
+        py_variant = to_py_variant(v)
+        campl.AMPL_VariantFree(&v)
+        return py_variant
 
     def set_data(self, data, set_name=None):
         """
diff --git a/amplpy/dataframe.pxi b/amplpy/dataframe.pxi
index 1351d87..c9f5dd2 100644
--- a/amplpy/dataframe.pxi
+++ b/amplpy/dataframe.pxi
@@ -36,7 +36,6 @@ cdef class Row(object):
 
     def __getitem__(self, key):
         cdef campl.AMPL_VARIANT* v
-        #campl.AMPL_DataFrameGetColumnIndex(self._df, key.encode('utf-8'), &column_index)
         campl.AMPL_DataFrameElement(self._df, self._index, key, &v)
         return to_py_variant(v)
 
diff --git a/amplpy/entity.pxi b/amplpy/entity.pxi
index 429c6f4..56ad2c9 100644
--- a/amplpy/entity.pxi
+++ b/amplpy/entity.pxi
@@ -48,6 +48,10 @@ cdef class Entity(object):
         entity.wrap_function = campl.AMPL_UNDEFINED
         return entity
 
+    #def __dealloc__(self):
+    #    if self._index is not NULL:
+    #        campl.AMPL_TupleFree(&self._index)
+
     def to_string(self):
         cdef char* output_c
         campl.AMPL_EntityGetDeclaration(self._c_ampl, self._name.encode('utf-8'), &output_c)
@@ -179,6 +183,7 @@ cdef class Entity(object):
             The string representation of the indexing sets for this entity or
             an empty array if the entity is scalar.
         """
+        cdef size_t i
         cdef size_t size
         cdef char** sets
         cdef list pylist = []
@@ -188,6 +193,9 @@ cdef class Entity(object):
                 pylist.append(sets[i].decode('utf-8'))
             else:
                 pylist.append(None)
+            campl.AMPL_StringFree(&sets[i])
+        free(sets)
+        
         return pylist
 
     def xref(self):
@@ -297,15 +305,18 @@ cdef class Entity(object):
             df = data
             df_c = df.get_ptr()
             campl.AMPL_EntitySetValues(self._c_ampl, _name_c, df_c)
+            campl.AMPL_StringFree(&_name_c)
         elif isinstance(data, dict):
             df = DataFrame.from_dict(data)
             df_c = df.get_ptr()
             campl.AMPL_EntitySetValues(self._c_ampl, _name_c, df_c)
+            campl.AMPL_StringFree(&_name_c)
         else:
             if pd is not None and isinstance(data, (pd.DataFrame, pd.Series)):
                 df = DataFrame.from_pandas(data, indexarity=self.indexarity())
                 df_c = df.get_ptr()
                 campl.AMPL_EntitySetValues(self._c_ampl, _name_c, df_c)
+                campl.AMPL_StringFree(&_name_c)
                 return
             raise TypeError(f"Unexpected data type: {type(data)}.")
 
diff --git a/amplpy/parameter.pxi b/amplpy/parameter.pxi
index acccb9b..88d7a94 100644
--- a/amplpy/parameter.pxi
+++ b/amplpy/parameter.pxi
@@ -79,7 +79,10 @@ cdef class Parameter(Entity):
         cdef campl.AMPL_VARIANT* v
         campl.AMPL_InstanceGetName(self._c_ampl, self._name.encode('utf-8'), tuple_c, &expression)
         campl.AMPL_GetValue(self._c_ampl, expression, &v)
-        return to_py_variant(v)
+        campl.AMPL_StringFree(&expression)
+        py_variant = to_py_variant(v)
+        campl.AMPL_VariantFree(&v)
+        return py_variant
 
     def value(self):
         """
@@ -87,7 +90,9 @@ cdef class Parameter(Entity):
         """
         cdef campl.AMPL_VARIANT* v
         campl.AMPL_GetValue(self._c_ampl, self._name.encode('utf-8'), &v)
-        return to_py_variant(v)
+        py_variant = to_py_variant(v)
+        campl.AMPL_VariantFree(&v)
+        return py_variant
 
     def set(self, *args):
         """
diff --git a/amplpy/util.pxi b/amplpy/util.pxi
index 744d7bf..44d239a 100644
--- a/amplpy/util.pxi
+++ b/amplpy/util.pxi
@@ -180,11 +180,13 @@ cdef void setValuesPyDict(campl.AMPL* ampl, str name, dicts):
         for i, (key, value) in enumerate(dicts.items()):
             key_c = to_c_tuple(key)
             campl.AMPL_ParameterInstanceSetStringValue(ampl, name.encode('utf-8'), key_c, value.encode('utf-8'))
+            campl.AMPL_TupleFree(&key_c)
     elif has_numbers and not has_strings:
         for i, (key, value) in enumerate(dicts.items()):
             if isinstance(value, int) or isinstance(value, float):
                 key_c = to_c_tuple(key)
-                campl.AMPL_ParameterInstanceSetNumericValue(ampl, name.encode('utf-8'), key_c, value)            
+                campl.AMPL_ParameterInstanceSetNumericValue(ampl, name.encode('utf-8'), key_c, value)   
+                campl.AMPL_TupleFree(&key_c)         
             else:
                 raise ValueError("Unexpected value type")
     else: