Performance improvement in XML marshaller by mimicking StringIO in unicode-friendly buffer UnicodeBuffer and added a class appy.gen.No allowing to explain why some workflow condition cannot be triggered.

shared/__init__.py

@@ -41,15 +41,17 @@ class UnicodeBuffer:
     '''With StringIO class, I have tons of encoding problems. So I define a
        similar class here, that uses an internal unicode buffer.'''
     def __init__(self):
-        self.buffer = u''
+        self.buffer = []
     def write(self, s):
         if s == None: return
         if isinstance(s, unicode):
-            self.buffer += s
+            self.buffer.append(s)
         elif isinstance(s, str):
-            self.buffer += s.decode('utf-8')
+            self.buffer.append(s.decode('utf-8'))
         else:
-            self.buffer += unicode(s)
+            self.buffer.append(unicode(s))
+    def getValue(self):
+        return u''.join(self.buffer)
 
 # ------------------------------------------------------------------------------
 class Dummy: pass

shared/xml_parser.py

@@ -503,7 +503,7 @@ class XmlMarshaller:
         self.marshallSpecificElements(instance, res)
         # Return the result
         res.write('</'); res.write(self.rootElementName); res.write('>')
-        res = res.buffer
+        res = res.getValue()
         if not self.dumpUnicode:
             res = res.encode('utf-8')
         return res