IReadable.read(): document out-of-range errors

[tahoe-lafs/tahoe-lafs.git] / src / allmydata / interfaces.py

diff --git a/src/allmydata/interfaces.py b/src/allmydata/interfaces.py
index 4ec5a0e6ce5deef32c00c0bae1dc7f394f0297d9..e495c759a0e7735833257cce6f1b898679936d1b 100644 (file)
--- a/src/allmydata/interfaces.py
+++ b/src/allmydata/interfaces.py
@@ -665,7 +665,10 @@ class IReadable(Interface):
         the last byte has been given to it, or because the consumer threw an
         exception during write(), possibly because it no longer wants to
         receive data). The portion downloaded will start at 'offset' and
-        contain 'size' bytes (or the remainder of the file if size==None).
+        contain 'size' bytes (or the remainder of the file if size==None). It
+        is an error to read beyond the end of the file: callers must use
+        get_size() and clip any non-default offset= and size= parameters. It
+        is permissible to read zero bytes.
 
         The consumer will be used in non-streaming mode: an IPullProducer
         will be attached to it.
@@ -1291,7 +1294,8 @@ class IDirectoryNode(IFilesystemNode):
         is a file, or if must_be_file is True and the child is a directory,
         I raise ChildOfWrongTypeError."""
 
-    def create_subdirectory(name, initial_children={}, overwrite=True, metadata=None):
+    def create_subdirectory(name, initial_children={}, overwrite=True,
+                            mutable=True, mutable_version=None, metadata=None):
         """I create and attach a directory at the given name. The new
         directory can be empty, or it can be populated with children
         according to 'initial_children', which takes a dictionary in the same