Merged revisions 88528 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
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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.
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3 files changed