[IMP] models: convert deprecated model._all_columns into a dynamic property

The mappings model._all_columns takes quite some memory (around 2MB per
registry) because of the numerous dictionaries (one per model) and inefficient
memory storage of column_info.  Since it is deprecated and almost no longer
used, it can be computed on demand.

openerp/addons/test_new_api/tests/test_related.py

@@ -111,9 +111,6 @@ class TestPropertyField(common.TransactionCase):
         self.partner._columns.update({
             'property_country': fields.property(type='many2one', relation="res.country", string="Country by company"),
         })
-        self.partner._all_columns.update({
-            'property_country': fields.column_info('property_country', self.partner._columns['property_country'], None, None, None),
-        })
         self.partner._field_create(cr)
 
         partner_id = self.partner.create(cr, alice, {

openerp/models.py

@@ -341,7 +341,7 @@ class BaseModel(object):
     # 1. includes self fields,
     # 2. uses column_info instead of a triple.
     # Warning: _all_columns is deprecated, use _fields instead
-    _all_columns = {}
+    # _all_columns = {}
 
     _table = None
     _log_create = False
@@ -491,7 +491,6 @@ class BaseModel(object):
         """
         field = cls._fields.pop(name)
         cls._columns.pop(name, None)
-        cls._all_columns.pop(name, None)
         if hasattr(cls, name):
             delattr(cls, name)
         return field
@@ -2898,7 +2897,7 @@ class BaseModel(object):
 
     @classmethod
     def _inherits_reload(cls):
-        """ Recompute the _inherit_fields and _all_columns mappings. """
+        """ Recompute the _inherit_fields mapping. """
         cls._inherit_fields = struct = {}
         for parent_model, parent_field in cls._inherits.iteritems():
             parent = cls.pool[parent_model]
@@ -2908,19 +2907,17 @@ class BaseModel(object):
             for name, source in parent._inherit_fields.iteritems():
                 struct[name] = (parent_model, parent_field, source[2], source[3])
 
-        # old-api stuff
-        cls._all_columns = cls._get_column_infos()
-
-    @classmethod
-    def _get_column_infos(cls):
-        """Returns a dict mapping all fields names (direct fields and
-           inherited field via _inherits) to a ``column_info`` struct
-           giving detailed columns """
+    @property
+    def _all_columns(self):
+        """ Returns a dict mapping all fields names (direct fields and inherited
+        field via _inherits) to a ``column_info`` struct giving detailed columns.
+        Deprecated.
+        """
         result = {}
         # do not inverse for loops, since local fields may hide inherited ones!
-        for k, (parent, m2o, col, original_parent) in cls._inherit_fields.iteritems():
+        for k, (parent, m2o, col, original_parent) in self._inherit_fields.iteritems():
             result[k] = fields.column_info(k, col, parent, m2o, original_parent)
-        for k, col in cls._columns.iteritems():
+        for k, col in self._columns.iteritems():
             result[k] = fields.column_info(k, col)
         return result
 
@@ -3024,7 +3021,7 @@ class BaseModel(object):
                     field = model._fields[field_name]
                     field._triggers.update(triggers)
 
-        # determine old-api cls._inherit_fields and cls._all_columns
+        # determine old-api structures about inherited fields
         cls._inherits_reload()
 
         # register stuff about low-level function fields

openerp/osv/fields.py

@@ -1681,6 +1681,8 @@ class column_info(object):
             contains it i.e in case of multilevel inheritance, ``None`` for
             local columns.
     """
+    __slots__ = ['name', 'column', 'parent_model', 'parent_column', 'original_parent']
+
     def __init__(self, name, column, parent_model=None, parent_column=None, original_parent=None):
         self.name = name
         self.column = column