data to pyobject mapping doesn't work

there could be multiple owners so we don't know which one
was used this time.  consequently the data is now always
copied when binding.

also need to use dealloc slot not the finalize slot

Author: rogerbinns

src/apsw.c

@@ -1069,9 +1069,6 @@ static PyObject *
 apsw_fini(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   fini_apsw_strings();
-#ifdef SQLITE_ENABLE_CARRAY
-  free(carray_owner_array);
-#endif
   Py_RETURN_NONE;
 }
 #endif

src/carray.c

@@ -1,60 +1,8 @@
 
-/* The destructor API does a callback on the void * passed in which means
-   we can't get back to the PyObject that owns it.  This array is
-   used to store the mapping.  Hopefully it can be deleted at some point.  */
-
-typedef struct
-{
-  void *aData;
-  PyObject *owner;
-} carray_pyobject_owner;
-
-static carray_pyobject_owner *carray_owner_array = 0;
-size_t carray_owner_array_length = 0;
-
-/* returns 0 on success, -1 on failure */
-static int
-carray_add_owner(void *aData, PyObject *owner)
-{
-  assert(aData && owner);
-
-  for (size_t i = 0; i < carray_owner_array_length; i++)
-  {
-    if (!carray_owner_array[i].aData)
-    {
-      carray_owner_array[i].aData = aData;
-      carray_owner_array[i].owner = owner;
-      return 0;
-    }
-  }
-  carray_pyobject_owner *new_array
-      = realloc(carray_owner_array, sizeof(carray_pyobject_owner) * (carray_owner_array_length + 1));
-  if (!new_array)
-    return -1;
-  carray_owner_array = new_array;
-  carray_owner_array[carray_owner_array_length].aData = aData;
-  carray_owner_array[carray_owner_array_length].owner = owner;
-  carray_owner_array_length++;
-  return 0;
-}
-
-/* returns the owner and clears the entry - ie can only be called once */
-static PyObject *
-carray_get_owner(void *aData)
-{
-  for (size_t i = 0; i < carray_owner_array_length; i++)
-  {
-    if (carray_owner_array[i].aData == aData)
-    {
-      PyObject *owner = carray_owner_array[i].owner;
-
-      carray_owner_array[i].aData = 0;
-      carray_owner_array[i].owner = 0;
-      return owner;
-    }
-  }
-  Py_UNREACHABLE();
-}
+/* The destructor API does a callback on the void * passed in, but we
+could have multiple PyObject owners referencing the same array so the
+data always has to be duplicated when passed to sqlite3_carray_bind/.
+   */
 
 typedef struct
 {
@@ -110,36 +58,35 @@ CArrayBind_init(PyObject *self_, PyObject *args, PyObject *kwargs)
   self->aData = self->view.buf;
   self->nData = self->view.len / 8;
   self->mFlags = flags;
-
-  if (carray_add_owner(self->aData, (PyObject *)self))
-  {
-    PyErr_NoMemory();
-    goto error;
-  }
-
   return 0;
+
 error:
   if (res == 0)
     PyBuffer_Release(&self->view);
+  self->aData = 0;
   return -1;
 }
 
 static void
-carray_bind_destructor(void *value)
+CArrayBind_dealloc(PyObject *self_)
 {
-  PyGILState_STATE gilstate = PyGILState_Ensure();
-  CArrayBind *self = (CArrayBind *)carray_get_owner(value);
-  PyBuffer_Release(&self->view);
-  /* undo incref in APSWCursor_dobinding */
-  Py_DECREF((PyObject *)self);
-  PyGILState_Release(gilstate);
+
+  CArrayBind *self = (CArrayBind *)self_;
+
+  if (self->aData)
+  {
+    PyBuffer_Release(&self->view);
+    self->aData = 0;
+  }
+  Py_TpFree(self_);
 }
 
 static PyTypeObject CArrayBindType = {
   PyVarObject_HEAD_INIT(NULL, 0).tp_name = "apsw.carray",
   .tp_basicsize = sizeof(CArrayBind),
-  .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+  .tp_flags = Py_TPFLAGS_DEFAULT,
   .tp_init = CArrayBind_init,
   .tp_new = PyType_GenericNew,
+  .tp_dealloc = CArrayBind_dealloc,
   .tp_doc = Apsw_carray_DOC,
 };

src/cursor.c

@@ -699,12 +699,9 @@ APSWCursor_dobinding(APSWCursor *self, int arg, PyObject *obj)
 #ifdef SQLITE_ENABLE_CARRAY
   else if (PyObject_TypeCheck(obj, &CArrayBindType) == 1)
   {
-    /* This is decref in carray_bind_destructor and ensures the buffer
-       lives at least as long as SQLite wants it to */
-    Py_INCREF(obj);
     CArrayBind *cab = (CArrayBind *)obj;
     res = sqlite3_carray_bind(self->statement->vdbestatement, arg, cab->aData, cab->nData, cab->mFlags,
-                              carray_bind_destructor);
+                              SQLITE_TRANSIENT);
   }
 #endif
   else if (CONVERT_BINDING)
@@ -2206,17 +2203,18 @@ PyObjectBind_init(PyObject *self_, PyObject *args, PyObject *kwargs)
 }
 
 static void
-PyObjectBind_finalize(PyObject *self)
+PyObjectBind_dealloc(PyObject *self)
 {
   Py_CLEAR(((PyObjectBind *)self)->object);
+  Py_TpFree(self);
 }
 
 static PyTypeObject PyObjectBindType = {
   PyVarObject_HEAD_INIT(NULL, 0).tp_name = "apsw.pyobject",
   .tp_basicsize = sizeof(PyObjectBind),
   .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
   .tp_init = PyObjectBind_init,
-  .tp_finalize = PyObjectBind_finalize,
+  .tp_dealloc = PyObjectBind_dealloc,
   .tp_new = PyType_GenericNew,
   .tp_doc = Apsw_pyobject_DOC,
 };