Improve fields Function that have the same function

Call only once the function with a list of names instead of name.
It will works only if the names is in the signature of the function and if all
the fields Function have the same arg.

trytond/osv/fields.py

@@ -27,6 +27,7 @@ import psycopg2
 import warnings
 import __builtin__
 import sha
+import inspect
 
 def _symbol_f(symb):
     if symb is None or symb == False:
@@ -628,8 +629,23 @@ class Function(Column):
 
     def get(self, cursor, obj, ids, name, user=None, offset=0, context=None,
             values=None):
-        return getattr(obj, self._fnct)(cursor, user, ids, name, self._arg,
-                context=context)
+        if isinstance(name, list):
+            names = name
+            # Test is the function works with a list of names
+            if 'names' in inspect.getargspec(getattr(obj, self._fnct))[0]:
+                return getattr(obj, self._fnct)(cursor, user, ids, names,
+                        self._arg, context=context)
+            res = {}
+            for name in names:
+                res[name] = getattr(obj, self._fnct)(cursor, user, ids, name,
+                        self._arg, context=context)
+            return res
+        else:
+            # Test is the function works with a list of names
+            if 'names' in inspect.getargspec(getattr(obj, self._fnct))[0]:
+                name = [name]
+            return getattr(obj, self._fnct)(cursor, user, ids, name, self._arg,
+                    context=context)
 
     def set(self, cursor, obj, obj_id, name, value, user=None, context=None):
         if self._fnct_inv:

trytond/osv/orm.py

@@ -1035,12 +1035,26 @@ class ORM(object):
         # whose name is in load is False
         fields_post = [x for x in fields_names if x in self._columns \
                 and not getattr(self._columns[x], load)]
+        func_fields = {}
         for field in fields_post:
+            if isinstance(self._columns[field], fields.Function):
+                key = (self._columns[field]._fnct, self._columns[field]._arg)
+                func_fields.setdefault(key, [])
+                func_fields[key].append(field)
+                continue
             # get the value of that field for all records/ids
             res2 = self._columns[field].get(cursor, self, ids, field, user,
                     context=context, values=res)
             for record in res:
                 record[field] = res2[record['id']]
+        for i in func_fields:
+            field_list = func_fields[i]
+            field = field_list[0]
+            res2 = self._columns[field].get(cursor, self, ids, field_list, user,
+                    context=context, values=res)
+            for field in res2:
+                for record in res:
+                    record[field] = res2[field][record['id']]
         return res
 
     def _validate(self, cursor, user, ids, context=None):