garbage collect when clear undo stack

Author: ArnoChenFx

NodeGraphQt/base/commands.py

@@ -1,7 +1,7 @@
 #!/usr/bin/python
 from .. import QtWidgets
-
 from ..constants import IN_PORT, OUT_PORT
+from .utils import minimize_node_ref_count
 
 
 class PropertyChangedCmd(QtWidgets.QUndoCommand):
@@ -177,6 +177,9 @@ def redo(self):
         self.model.nodes.pop(self.node.id)
         self.node.delete()
 
+    def __del__(self):
+        minimize_node_ref_count(self.node)
+
 
 class NodeInputConnectedCmd(QtWidgets.QUndoCommand):
     """

NodeGraphQt/base/graph.py

@@ -4,7 +4,7 @@
 import os
 import re
 import copy
-
+import gc
 from .. import QtCore, QtWidgets, QtGui
 from .commands import (NodeAddedCmd,
                        NodeRemovedCmd,
@@ -541,6 +541,7 @@ def clear_undo_stack(self):
             :meth:`NodeGraph.undo_stack()`
         """
         self._undo_stack.clear()
+        gc.collect()
 
     def begin_undo(self, name):
         """
@@ -1095,7 +1096,7 @@ def clear_session(self):
                 continue
             self._undo_stack.push(NodeRemovedCmd(self, n))
         self.set_node_space(root_node)
-        self._undo_stack.clear()
+        self.clear_undo_stack()
         self._model.session = None
         self.session_changed.emit("")
 
@@ -1251,7 +1252,7 @@ def deserialize_session(self, layout_data):
         """
         self.clear_session()
         self._deserialize(layout_data)
-        self._undo_stack.clear()
+        self.clear_undo_stack()
 
     def save_session(self, file_path):
         """
@@ -1326,7 +1327,7 @@ def import_session(self, file_path):
             self.set_grid_mode(layout_data['graph'].get('grid_mode', VIEWER_GRID_LINES))
 
         self.set_node_space(self.root_node())
-        self._undo_stack.clear()
+        self.clear_undo_stack()
         self._model.session = file_path
         self.session_changed.emit(file_path)
         self._auto_update = _temp_auto_update

NodeGraphQt/base/node.py

@@ -462,7 +462,7 @@ def delete(self):
         self._view.delete()
         if self._parent is not None:
             self._parent.remove_child(self)
-        # self.set_parent(None)
+            self._parent = None
 
     def hide(self):
         """
@@ -884,7 +884,6 @@ def delete_input(self, port):
         self._inputs.remove(port)
         self._model.inputs.pop(port.name())
         self._view.delete_input(port.view)
-        del port
         self.draw()
 
     def delete_output(self, port):
@@ -901,7 +900,6 @@ def delete_output(self, port):
         self._outputs.remove(port)
         self._model.outputs.pop(port.name())
         self._view.delete_output(port.view)
-        del port
         self.draw()
 
     def set_ports(self, port_data):

NodeGraphQt/base/utils.py

@@ -214,7 +214,7 @@ def _clear_undo(graph):
     viewer = graph.viewer()
     msg = 'Clear all undo history, Are you sure?'
     if viewer.question_dialog('Clear Undo History', msg):
-        graph.undo_stack().clear()
+        graph.clear_undo_stack()
 
 
 def _copy_nodes(graph):
@@ -748,3 +748,36 @@ def auto_layout_down(start_nodes=[], all_nodes=[]):
             current_y += dy * 0.5 + 10
 
         current_x += max_width * 0.5 + 100
+
+
+# garbage collect
+
+def minimize_node_ref_count(node):
+    """
+    Minimize node reference count for garbage collect.
+
+    Args:
+        node (NodeGraphQt.NodeObject): node.
+    """
+    if node.graph is None or node.id not in node.graph.model.nodes:
+        if hasattr(node, 'deleted'):
+            del node
+            return
+        from .node import BaseNode, SubGraph
+        node._parent = None
+        if isinstance(node, BaseNode):
+            [wid.deleteLater() for wid in node.view._widgets.values()]
+            node.view._widgets.clear()
+            for port in node._inputs:
+                port.model.node = None
+            for port in node._outputs:
+                port.model.node = None
+
+            if isinstance(node, SubGraph):
+                node._children.clear()
+                node.sub_graph_input_nodes.clear()
+                node.sub_graph_output_nodes.clear()
+            if isinstance(node, QtCore.QObject):
+                node.deleteLater()
+            node.deleted = True
+        del node

example_auto_nodes/node_base/auto_node.py

@@ -365,4 +365,9 @@ def error(self, message=None):
             return self._error
         self._show_error(message)
 
+    # def __del__(self):
+    #     """
+    #     Check gc.
+    #     """
+    #     print("Delete: ", self.name())