replace StringIO with cStringIO in python 2.x

Author: chfw

ezodf/bytestreammanager.py

@@ -15,9 +15,9 @@
 class ByteStreamManager(FileManager):
     def __init__(self, buffer=None):
         if is_stream(buffer):
-            self._zipfile_as_bytes = buffer
+            self._zipfile_as_bytes = buffer.getvalue()
         else:
-            self._zipfile_as_bytes = StringIO(buffer)
+            self._zipfile_as_bytes = buffer
         super(ByteStreamManager, self).__init__()
 
     def save(self, filename, backup=False):
@@ -31,5 +31,4 @@ def has_zip(self):
         return self._zipfile_as_bytes is not None
 
     def _open_bytestream(self):
-        self._zipfile_as_bytes.seek(0)
-        return self._zipfile_as_bytes
+        return StringIO(self._zipfile_as_bytes)

ezodf/compatibility.py

@@ -40,8 +40,9 @@ def is_stream(instance):
 
 else: # PY2
     # distiguish StringIO
-    from StringIO import StringIO
+    from cStringIO import StringIO
     from cStringIO import InputType, OutputType
+    from StringIO import SlowStringIO
 
     tostr=unicode
     def is_string(value):
@@ -80,4 +81,4 @@ def is_zipfile(data):
     def is_stream(instance):
         return (isinstance(instance, InputType) or
                 isinstance(instance, OutputType) or
-                isinstance(instance, StringIO))
+                isinstance(instance, SlowStringIO))