From 1baf7070a3014ae6455835d95ea4f60d8a821101 Mon Sep 17 00:00:00 2001
From: Benny Malengier <benny.malengier@gramps-project.org>
Date: Sun, 31 Oct 2010 08:38:05 +0000
Subject: [PATCH] 4333: memory leak in 3.2

svn: r16092
---
 src/Lru.py                                   |  3 +++
 src/gen/db/read.py                           | 24 ++++++++++++++---
 src/gen/db/undoredo.py                       |  4 +++
 src/gen/db/write.py                          | 19 ++++++++++++-
 src/gen/utils/callback.py                    | 13 +++++++--
 src/gen/utils/configmanager.py               | 16 ++++++-----
 src/gui/editors/displaytabs/nameembedlist.py | 10 +++++++
 src/gui/editors/editfamily.py                |  9 +++++++
 src/gui/editors/editname.py                  | 18 ++++++++-----
 src/gui/editors/editperson.py                |  5 ++++
 src/gui/editors/editprimary.py               | 17 ++++++++++--
 src/gui/editors/editsecondary.py             | 17 ++++++++++--
 src/gui/views/listview.py                    |  3 +++
 src/gui/views/treemodels/eventmodel.py       | 11 ++++++++
 src/gui/views/treemodels/familymodel.py      | 11 ++++++++
 src/gui/views/treemodels/flatbasemodel.py    | 20 ++++++++++++++
 src/gui/views/treemodels/mediamodel.py       | 11 ++++++++
 src/gui/views/treemodels/notemodel.py        | 11 ++++++++
 src/gui/views/treemodels/peoplemodel.py      | 28 +++++++++++++++++++-
 src/gui/views/treemodels/placemodel.py       | 26 ++++++++++++++++++
 src/gui/views/treemodels/repomodel.py        | 12 +++++++++
 src/gui/views/treemodels/sourcemodel.py      | 11 ++++++++
 src/gui/views/treemodels/treebasemodel.py    | 20 ++++++++++++++
 23 files changed, 295 insertions(+), 24 deletions(-)

diff --git a/src/Lru.py b/src/Lru.py
index 4928cbc1f..c35dc3fed 100644
--- a/src/Lru.py
+++ b/src/Lru.py
@@ -151,4 +151,7 @@ class LRU(object):
         """
         Empties LRU
         """
+        for obj, node in self.data.iteritems():
+            node.prev = None
+            node.next = None
         self.data.clear()
diff --git a/src/gen/db/read.py b/src/gen/db/read.py
index 7dd254c71..03d36e8b1 100644
--- a/src/gen/db/read.py
+++ b/src/gen/db/read.py
@@ -92,6 +92,9 @@ class DbBookmarks(object):
     def insert(self, pos, item):
         self.bookmarks.insert(pos, item)
 
+    def close(self):
+        del self.bookmarks
+
 #-------------------------------------------------------------------------
 #
 # GrampsDBReadCursor
@@ -169,7 +172,6 @@ class DbBsddbRead(DbReadBase, Callback):
         """
         Create a new DbBsddbRead instance. 
         """
-        
         DbReadBase.__init__(self)
         Callback.__init__(self)
 
@@ -379,8 +381,24 @@ class DbBsddbRead(DbReadBase, Callback):
         
         The method needs to be overridden in the derived class.
         """
-        pass
-        
+        #remove links to functions
+        self.disconnect_all()
+        for key in self._tables:
+            for subkey in self._tables[key]:
+                self._tables[key][subkey] = None
+            del self._tables[key][subkey]
+            self._tables[key] = None
+        del self._tables
+##        self.bookmarks = None
+##        self.family_bookmarks = None
+##        self.event_bookmarks = None
+##        self.place_bookmarks = None
+##        self.source_bookmarks = None
+##        self.repo_bookmarks = None
+##        self.media_bookmarks = None
+##        self.note_bookmarks = None
+
+
     def is_open(self):
         """
         Return 1 if the database has been opened.
diff --git a/src/gen/db/undoredo.py b/src/gen/db/undoredo.py
index 203af9857..0ad14da0d 100644
--- a/src/gen/db/undoredo.py
+++ b/src/gen/db/undoredo.py
@@ -414,6 +414,10 @@ class DbUndoBSDDB(DbUndo):
         Close the undo/redo database
         """
         self.undodb.close()
+        self.undodb = None
+        self.mapbase = None
+        self.db = None
+        
         try:
             os.remove(self.path)
         except OSError:
diff --git a/src/gen/db/write.py b/src/gen/db/write.py
index dbe5bfd15..739d28657 100644
--- a/src/gen/db/write.py
+++ b/src/gen/db/write.py
@@ -1000,7 +1000,6 @@ class DbBsddb(DbBsddbRead, DbWriteBase, UpdateCallback):
     def close(self):
         if not self.db_is_open:
             return
-
         self.env.txn_checkpoint()
 
         self.__close_metadata()
@@ -1045,6 +1044,24 @@ class DbBsddb(DbBsddbRead, DbWriteBase, UpdateCallback):
         self.env            = None
         self.metadata       = None
         self.db_is_open     = False
+        
+        DbBsddbRead.close(self)
+        
+        self.person_map = None
+        self.family_map = None
+        self.repository_map = None
+        self.note_map = None
+        self.place_map = None
+        self.source_map = None
+        self.media_map = None
+        self.event_map = None
+        self.reference_map_primary_map = None
+        self.reference_map_referenced_map = None
+        self.reference_map = None
+        self.undo_callback = None
+        self.redo_callback = None
+        self.undo_history_callback = None
+        self.undodb = None
 
         try:
             clear_lock_file(self.get_save_path())
diff --git a/src/gen/utils/callback.py b/src/gen/utils/callback.py
index 04c98878d..50eaa031e 100644
--- a/src/gen/utils/callback.py
+++ b/src/gen/utils/callback.py
@@ -40,6 +40,7 @@ import sys
 import types
 import traceback
 import inspect
+import copy
 
 log = sys.stderr.write
 
@@ -311,8 +312,16 @@ class Callback(object):
                               ": %s with key: %s\n" % (signal_name, 
                                                        str(key)))
                     self.__callback_map[signal_name].remove(cb)
-                    
-                    
+
+    def disconnect_all(self):# Find the key in the callback map.
+        for signal_name in self.__callback_map:
+            keymap = copy.copy(self.__callback_map[signal_name])
+            for key in keymap:
+                self.__callback_map[signal_name].remove(key)
+            self.__callback_map[signal_name] = None
+        self.__callback_map = None
+        del self.__callback_map
+
     def emit(self, signal_name, args=tuple()):
         """
         Emit the signal called signal_name. The args must be a tuple of
diff --git a/src/gen/utils/configmanager.py b/src/gen/utils/configmanager.py
index b73d5c1fd..9aaf129d3 100644
--- a/src/gen/utils/configmanager.py
+++ b/src/gen/utils/configmanager.py
@@ -38,14 +38,18 @@ import ConfigParser
 import errno
 import copy
 
-try:
-    from ast import literal_eval as safe_eval
-except:
-    # PYTHON2.5 COMPATIBILITY: no ast present
-    # not as safe as literal_eval, but works for python2.5:
-    def safe_eval(exp):
+def safe_eval(exp):
         # restrict eval to empty environment
         return eval(exp, {})
+##try:
+##    from ast import literal_eval as safe_eval
+##    # this leaks memory !!
+##except:
+##    # PYTHON2.5 COMPATIBILITY: no ast present
+##    # not as safe as literal_eval, but works for python2.5:
+##    def safe_eval(exp):
+##        # restrict eval to empty environment
+##        return eval(exp, {})
 
 #---------------------------------------------------------------
 #
diff --git a/src/gui/editors/displaytabs/nameembedlist.py b/src/gui/editors/displaytabs/nameembedlist.py
index 40a3af727..65d153a25 100644
--- a/src/gui/editors/displaytabs/nameembedlist.py
+++ b/src/gui/editors/displaytabs/nameembedlist.py
@@ -78,6 +78,8 @@ class NameEmbedList(GroupEmbeddedList):
         ]
     
     def __init__(self, dbstate, uistate, track, data, person, callback):
+        """callback is the function to call when preferred name changes
+           on the namelist """
         self.data = data
         self.person = person
         self.callback = callback
@@ -86,6 +88,14 @@ class NameEmbedList(GroupEmbeddedList):
                               NameModel, move_buttons=True)
         self.tree.expand_all()
 
+    def _cleanup_on_exit(self):
+        """Unset all things that can block garbage collection.
+        Finalize rest
+        """
+        self.person = None
+        self.callback = None
+        self.data = None
+
     def get_data(self):
         return ([self.person.get_primary_name()], 
                  self.data)
diff --git a/src/gui/editors/editfamily.py b/src/gui/editors/editfamily.py
index d7e852520..8765a4be2 100644
--- a/src/gui/editors/editfamily.py
+++ b/src/gui/editors/editfamily.py
@@ -425,6 +425,15 @@ class EditFamily(EditPrimary):
         else:
             self.add_parent = False
 
+    def _cleanup_on_exit(self):
+        """Unset all things that can block garbage collection.
+        Finalize rest
+        """
+        #FIXME, we rebind show_all below, this prevents garbage collection of
+        #  the dialog, fix the rebind
+        self.window.show_all = None
+        EditPrimary._cleanup_on_exit(self)
+
     def empty_object(self):
         return gen.lib.Family()
 
diff --git a/src/gui/editors/editname.py b/src/gui/editors/editname.py
index e95622ade..f70b56a43 100644
--- a/src/gui/editors/editname.py
+++ b/src/gui/editors/editname.py
@@ -248,16 +248,17 @@ class EditName(EditSecondary):
         notebook = self.top.get_object("notebook")
 
         self._add_tab(notebook, self.gennam)
+        self.track_ref_for_deletion("gennam")
 
-        self.srcref_list = self._add_tab(
-            notebook,
-            SourceEmbedList(self.dbstate,self.uistate,self.track,self.obj))
+        self.srcref_list = SourceEmbedList(self.dbstate,self.uistate,self.track,self.obj)
+        self._add_tab(notebook, self.srcref_list)
+        self.track_ref_for_deletion("srcref_list")
         
-        self.note_tab = self._add_tab(
-            notebook,
-            NoteTab(self.dbstate, self.uistate, self.track,
+        self.note_tab = NoteTab(self.dbstate, self.uistate, self.track,
                     self.obj.get_note_list(),
-                    notetype=NoteType.PERSONNAME))
+                    notetype=NoteType.PERSONNAME)
+        self._add_tab(notebook, self.note_tab)
+        self.track_ref_for_deletion("note_tab")
 
         self._setup_notebook_tabs( notebook)
         
@@ -423,6 +424,7 @@ class EditName(EditSecondary):
         if closeit:
             if self.callback:
                 self.callback(self.obj)
+            self.callback = None
             self.close()
 
     def _cleanup_on_exit(self):
@@ -434,5 +436,7 @@ class EditName(EditSecondary):
         data must be saved, and also bug 1892 occurs on reopening of the editor.
         """
         # can't use group_over, see Note in gen/lib/name/Name.set_group_as().
+        print 'cleaning up'
         if not self.group_as.obj.get_editable():
             self.obj.set_group_as("")
+        EditSecondary._cleanup_on_exit(self)
diff --git a/src/gui/editors/editperson.py b/src/gui/editors/editperson.py
index b497e4da9..6b82fca89 100644
--- a/src/gui/editors/editperson.py
+++ b/src/gui/editors/editperson.py
@@ -754,6 +754,7 @@ class EditPerson(EditPrimary):
         self.close()
         if self.callback:
             self.callback(self.obj)
+        self.callback = None
 
     def _edit_name_clicked(self, obj):
         """
@@ -889,10 +890,14 @@ class EditPerson(EditPrimary):
         return child_ref_list
 
     def _cleanup_on_exit(self):
+        """Unset all things that can block garbage collection.
+        Finalize rest
+        """
         config.set('interface.prefix-suffix', self.prefix_suffix.active_key)
         config.set('interface.patro-title', self.patro_title.active_key)
         config.save()
 
+        EditPrimary._cleanup_on_exit(self)
 
 class GenderDialog(gtk.MessageDialog):
     def __init__(self, parent=None):
diff --git a/src/gui/editors/editprimary.py b/src/gui/editors/editprimary.py
index b6ca9a764..6aa9e1bf6 100644
--- a/src/gui/editors/editprimary.py
+++ b/src/gui/editors/editprimary.py
@@ -151,7 +151,13 @@ class EditPrimary(ManagedWindow.ManagedWindow, DbGUIElement):
         return page
 
     def _cleanup_on_exit(self):
-        pass
+        """Unset all things that can block garbage collection.
+        Finalize rest
+        """
+        for tab in self.__tabs:
+            if hasattr(tab, '_cleanup_on_exit'):
+                tab._cleanup_on_exit()
+        self.__tabs = None
 
     def object_is_empty(self):
         return cmp(self.obj.serialize()[1:],
@@ -173,7 +179,12 @@ class EditPrimary(ManagedWindow.ManagedWindow, DbGUIElement):
         self._cleanup_db_connects()
         self.dbstate.disconnect(self.dbstate_connect_key)
         self._cleanup_on_exit()
+        self.get_from_handle = None
+        self.get_from_gramps_id = None
         ManagedWindow.ManagedWindow.close(self)
+        self.dbstate = None
+        self.uistate = None
+        self.db = None
 
     def _cleanup_db_connects(self):
         """
@@ -236,7 +247,9 @@ class EditPrimary(ManagedWindow.ManagedWindow, DbGUIElement):
                        self.obj.serialize()[1:]) != 0
 
     def save(self, *obj):
-        pass
+        """ Save changes and close. Inheriting classes must implement this
+        """
+        self.close()
         
     def set_contexteventbox(self, eventbox):
         """Set the contextbox that grabs button presses if not grabbed
diff --git a/src/gui/editors/editsecondary.py b/src/gui/editors/editsecondary.py
index 0126f22f6..80c8784c6 100644
--- a/src/gui/editors/editsecondary.py
+++ b/src/gui/editors/editsecondary.py
@@ -106,7 +106,20 @@ class EditSecondary(ManagedWindow.ManagedWindow, DbGUIElement):
         return page
 
     def _cleanup_on_exit(self):
-        pass
+        """Unset all things that can block garbage collection.
+        Finalize rest
+        """
+        for tab in self.__tabs:
+            if hasattr(tab, '_cleanup_on_exit'):
+                tab._cleanup_on_exit()
+        self.__tabs = None
+        self.dbstate = None
+        self.uistate = None
+        self.obj = None
+        self.db = None
+        if self.callman:
+            self.callman.database = None
+        self.callman = None
 
     def define_ok_button(self,button,function):
         button.connect('clicked',function)
@@ -121,8 +134,8 @@ class EditSecondary(ManagedWindow.ManagedWindow, DbGUIElement):
 
     def close(self,*obj):
         self._cleanup_db_connects()
-        self._cleanup_on_exit()
         ManagedWindow.ManagedWindow.close(self)
+        self._cleanup_on_exit()
 
     def _cleanup_db_connects(self):
         """
diff --git a/src/gui/views/listview.py b/src/gui/views/listview.py
index 17ccf85dc..f6c4dee26 100644
--- a/src/gui/views/listview.py
+++ b/src/gui/views/listview.py
@@ -258,6 +258,9 @@ class ListView(NavigationView):
                 filter_info = (False, value, value[0] in self.exact_search())
 
             if self.dirty or not self.model:
+                if self.model:
+                    self.list.set_model(None)
+                    self.model.destroy()
                 self.model = self.make_model(self.dbstate.db, self.sort_col, 
                                              search=filter_info,
                                              sort_map=self.column_order())
diff --git a/src/gui/views/treemodels/eventmodel.py b/src/gui/views/treemodels/eventmodel.py
index e98e6d52a..0fa85c545 100644
--- a/src/gui/views/treemodels/eventmodel.py
+++ b/src/gui/views/treemodels/eventmodel.py
@@ -101,6 +101,17 @@ class EventModel(FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, tooltip_column=9,
                            search=search, skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def on_get_n_columns(self):
         return len(self.fmap)+1
 
diff --git a/src/gui/views/treemodels/familymodel.py b/src/gui/views/treemodels/familymodel.py
index df62d927d..7a2619c19 100644
--- a/src/gui/views/treemodels/familymodel.py
+++ b/src/gui/views/treemodels/familymodel.py
@@ -90,6 +90,17 @@ class FamilyModel(FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, tooltip_column=6, 
                            search=search, skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def marker_column(self):
         """
         Return the column for marker colour.
diff --git a/src/gui/views/treemodels/flatbasemodel.py b/src/gui/views/treemodels/flatbasemodel.py
index 005a294b4..0b2a12c99 100644
--- a/src/gui/views/treemodels/flatbasemodel.py
+++ b/src/gui/views/treemodels/flatbasemodel.py
@@ -122,6 +122,14 @@ class FlatNodeMap(object):
         self._reverse = False
         self.__corr = (0, 1)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self._index2hndl = None
+        self._fullhndl = None
+        self._hndl2index = None
+
     def set_path_map(self, index2hndllist, fullhndllist, identical=True,
                      reverse=False):
         """
@@ -414,6 +422,18 @@ class FlatBaseModel(gtk.GenericTreeModel):
         _LOG.debug(self.__class__.__name__ + ' __init__ ' +
                     str(time.clock() - cput) + ' sec')
 
+    def destroy(self):
+        """
+        Unset all elements that prevent garbage collection
+        """
+        self.db = None
+        self.sort_func = None
+        if self.node_map:
+            self.node_map.destroy()
+        self.node_map = None
+        self.rebuild_data = None
+        self.search = None
+
     def set_search(self, search):
         """
         Change the search function that filters the data in the model. 
diff --git a/src/gui/views/treemodels/mediamodel.py b/src/gui/views/treemodels/mediamodel.py
index 2f58ed56b..e6ad5c5a4 100644
--- a/src/gui/views/treemodels/mediamodel.py
+++ b/src/gui/views/treemodels/mediamodel.py
@@ -83,6 +83,17 @@ class MediaModel(FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, tooltip_column=7,
                            search=search, skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def on_get_n_columns(self):
         return len(self.fmap)+1
 
diff --git a/src/gui/views/treemodels/notemodel.py b/src/gui/views/treemodels/notemodel.py
index e72b88d52..07ba85f82 100644
--- a/src/gui/views/treemodels/notemodel.py
+++ b/src/gui/views/treemodels/notemodel.py
@@ -78,6 +78,17 @@ class NoteModel(FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, search=search,
                            skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def marker_column(self):
         """
         Return the column for marker colour.
diff --git a/src/gui/views/treemodels/peoplemodel.py b/src/gui/views/treemodels/peoplemodel.py
index 3f8fee959..49cc6ff1e 100644
--- a/src/gui/views/treemodels/peoplemodel.py
+++ b/src/gui/views/treemodels/peoplemodel.py
@@ -146,6 +146,17 @@ class PeopleBaseModel(object):
         self.lru_bdate = LRU(PeopleBaseModel._CACHE_SIZE)
         self.lru_ddate = LRU(PeopleBaseModel._CACHE_SIZE)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        self.clear_local_cache()
+
     def marker_column(self):
         """
         Return the column for marker colour.
@@ -454,7 +465,6 @@ class PersonListModel(PeopleBaseModel, FlatBaseModel):
     """
     def __init__(self, db, scol=0, order=gtk.SORT_ASCENDING, search=None,
                  skip=set(), sort_map=None):
-
         PeopleBaseModel.__init__(self, db)
         FlatBaseModel.__init__(self, db, search=search, skip=skip,
                                 tooltip_column=12,
@@ -464,6 +474,13 @@ class PersonListModel(PeopleBaseModel, FlatBaseModel):
         """ Clear the LRU cache """
         PeopleBaseModel.clear_local_cache(self, handle)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        PeopleBaseModel.destroy(self)
+        FlatBaseModel.destroy(self)
+
 class PersonTreeModel(PeopleBaseModel, TreeBaseModel):
     """
     Hierarchical people model.
@@ -475,6 +492,15 @@ class PersonTreeModel(PeopleBaseModel, TreeBaseModel):
         TreeBaseModel.__init__(self, db, 12, search=search, skip=skip,
                                 scol=scol, order=order, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        PeopleBaseModel.destroy(self)
+        self.hmap = None
+        self.number_items = None
+        TreeBaseModel.destroy(self)
+
     def _set_base_data(self):
         """See TreeBaseModel, we also set some extra lru caches
         """
diff --git a/src/gui/views/treemodels/placemodel.py b/src/gui/views/treemodels/placemodel.py
index e327f8b2c..1b7346ece 100644
--- a/src/gui/views/treemodels/placemodel.py
+++ b/src/gui/views/treemodels/placemodel.py
@@ -117,6 +117,16 @@ class PlaceBaseModel(object):
             self.column_handle,
             ]
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+
     def on_get_n_columns(self):
         return len(self.fmap)+1
 
@@ -218,6 +228,13 @@ class PlaceListModel(PlaceBaseModel, FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, tooltip_column=14,
                            search=search, skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        PlaceBaseModel.destroy(self)
+        FlatBaseModel.destroy(self)
+
     def column_name(self, data):
         return unicode(data[2])
 
@@ -240,6 +257,15 @@ class PlaceTreeModel(PlaceBaseModel, TreeBaseModel):
                                 nrgroups = 3,
                                 group_can_have_handle = True)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        PlaceBaseModel.destroy(self)
+        self.hmap = None
+        self.number_items = None
+        TreeBaseModel.destroy(self)
+
     def _set_base_data(self):
         """See TreeBaseModel, for place, most have been set in init of
         PlaceBaseModel
diff --git a/src/gui/views/treemodels/repomodel.py b/src/gui/views/treemodels/repomodel.py
index 2d5ac4738..fadb4532a 100644
--- a/src/gui/views/treemodels/repomodel.py
+++ b/src/gui/views/treemodels/repomodel.py
@@ -94,6 +94,18 @@ class RepositoryModel(FlatBaseModel):
         FlatBaseModel.__init__(self, db, scol, order, tooltip_column=14,
                            search=search, skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.get_handles = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def on_get_n_columns(self):
         return len(self.fmap)+1
 
diff --git a/src/gui/views/treemodels/sourcemodel.py b/src/gui/views/treemodels/sourcemodel.py
index c985acf55..0842c3372 100644
--- a/src/gui/views/treemodels/sourcemodel.py
+++ b/src/gui/views/treemodels/sourcemodel.py
@@ -77,6 +77,17 @@ class SourceModel(FlatBaseModel):
         FlatBaseModel.__init__(self,db,scol, order,tooltip_column=7,search=search,
                            skip=skip, sort_map=sort_map)
 
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.db = None
+        self.gen_cursor = None
+        self.map = None
+        self.fmap = None
+        self.smap = None
+        FlatBaseModel.destroy(self)
+
     def on_get_n_columns(self):
         return len(self.fmap)+1
 
diff --git a/src/gui/views/treemodels/treebasemodel.py b/src/gui/views/treemodels/treebasemodel.py
index c077cb1e3..e7007e7e2 100644
--- a/src/gui/views/treemodels/treebasemodel.py
+++ b/src/gui/views/treemodels/treebasemodel.py
@@ -173,6 +173,12 @@ class NodeMap(object):
     """
     def __init__(self):
         self.id2node = {}
+
+    def destroy(self):
+        """
+        Unset all elements that can prevent garbage collection
+        """
+        self.id2node.clear()
     
     def add_node(self, node):
         """
@@ -321,6 +327,20 @@ class TreeBaseModel(gtk.GenericTreeModel):
         _LOG.debug(self.__class__.__name__ + ' __init__ ' +
                     str(time.clock() - cput) + ' sec')
 
+    def destroy(self):
+        """
+        Unset all elements that prevent garbage collection
+        """
+        self.db = None
+        self.sort_func = None
+        if self.nodemap:
+            self.nodemap.destroy()
+        self.nodemap = None
+        self.rebuild_data = None
+        self._build_data = None
+        self.search = None
+        self.clear_cache()
+
     def _set_base_data(self):
         """
         This method must be overwritten in the inheriting class, setting