Merged revisions 88528 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
........
r88528 | lars.gustaebel | 2011-02-23 12:42:22 +0100 (Wed, 23 Feb 2011) | 16 lines
Issue #11224: Improved sparse file read support (r85916) introduced a
regression in _FileInFile which is used in file-like objects returned
by TarFile.extractfile(). The inefficient design of the
_FileInFile.read() method causes various dramatic side-effects and
errors:
- The data segment of a file member is read completely into memory
every(!) time a small block is accessed. This is not only slow
but may cause unexpected MemoryErrors with very large files.
- Reading members from compressed tar archives is even slower
because of the excessive backwards seeking which is done when the
same data segment is read over and over again.
- As a backwards seek on a TarFile opened in stream mode is not
possible, using extractfile() fails with a StreamError.
........
diff --git a/Misc/NEWS b/Misc/NEWS
index a5ac7c1..7488686 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -15,6 +15,10 @@
Library
-------
+- Issue #11224: Fixed a regression in tarfile that affected the file-like
+ objects returned by TarFile.extractfile() regarding performance, memory
+ consumption and failures with the stream interface.
+
- Issue #11074: Make 'tokenize' so it can be reloaded.
- Issue #4681: Allow mmap() to work on file sizes and offsets larger than