Mercurial > hgsubversion
view tests/fixtures/executable_file_empty_prop.svndump @ 931:e1dbd9646d6a
svnwrap: use custom StringIO class in get_file()
The wrappers were calling ra.get_file() with a cStringIO object.
Empirically, svn 1.7.5 is writing 16kB blocks to the stream object, and
cStringIO reallocates its internal buffer and doubles its size whenever
it is filled. With large committed files this requires two large
memory blocks at the same time.
SimpleStringIO implements the mimimum StringIO interface used by
ra.get_file() but instead stores all the blocks and "join" them at the
end. It means more fragmentation but requires only one large block,
without overallocation. Also, 16kB blocks should be friendly to most
allocators.
In practice, this simple change let me convert a revision containing
multiple moderately large files, the largest being around 450MB, with a
32-bits Windows setup, python 2.7, swig svn 1.7.5, in stupid mode, while
it was previously aborting with "not enough memory". The same revision
still fails in replay mode.
| author | Patrick Mezard <patrick@mezard.eu> |
|---|---|
| date | Sun, 16 Sep 2012 19:31:49 +0200 |
| parents | 5497d1264b4d |
| children |
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SVN-fs-dump-format-version: 2 UUID: 60adb0cc-4d5c-4038-bbb4-90f4595cf81c Revision-number: 0 Prop-content-length: 56 Content-length: 56 K 8 svn:date V 27 2008-11-25T15:02:16.557895Z PROPS-END Revision-number: 1 Prop-content-length: 115 Content-length: 115 K 7 svn:log V 15 Basic structure K 10 svn:author V 5 Augie K 8 svn:date V 27 2008-11-25T15:02:45.454954Z PROPS-END Node-path: branches Node-kind: dir Node-action: add Prop-content-length: 10 Content-length: 10 PROPS-END Node-path: tags Node-kind: dir Node-action: add Prop-content-length: 10 Content-length: 10 PROPS-END Node-path: trunk Node-kind: dir Node-action: add Prop-content-length: 10 Content-length: 10 PROPS-END Revision-number: 2 Prop-content-length: 103 Content-length: 103 K 7 svn:log V 4 blah K 10 svn:author V 5 Augie K 8 svn:date V 27 2008-11-25T15:03:45.151223Z PROPS-END Node-path: trunk/foo Node-kind: file Node-action: add Prop-content-length: 36 Text-content-length: 4 Text-content-md5: c157a79031e1c40f85931829bc5fc552 Content-length: 40 K 14 svn:executable V 0 PROPS-END bar