Added clen attribute to imgstreams.

[automanga.git] / manga / lib.py

diff --git a/manga/lib.py b/manga/lib.py
index e7c531c..d901e9f 100644 (file)
--- a/manga/lib.py
+++ b/manga/lib.py
@@ -115,7 +115,9 @@ class imgstream(object):
     when exiting the with-scope.
 
     All imgstreams should contain an attribute `ctype', being the
-    Content-Type of the image being read by the stream."""
+    Content-Type of the image being read by the stream, and `clen`,
+    being either an int describing the total number of bytes in the
+    stream, or None if the value is not known in advance."""
 
     def __enter__(self):
         return self
@@ -123,6 +125,12 @@ class imgstream(object):
     def __exit__(self, *exc_info):
         self.close()
 
+    def fileno(self):
+        """If reading the imgstream may block, fileno() should return
+        a file descriptor that can be polled. If fileno() returns
+        None, that should mean that reading will not block."""
+        return None
+
     def close(self):
         """Close this stream."""
         raise NotImplementedError()