Mercurial > hgsubversion
view tests/fixtures/two_revs.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 | d78dbf88c13d |
| children |
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SVN-fs-dump-format-version: 2 UUID: df2126f7-00ab-4d49-b42c-7e981dde0bcf Revision-number: 0 Prop-content-length: 56 Content-length: 56 K 8 svn:date V 27 2008-10-07T22:49:12.059692Z PROPS-END Revision-number: 1 Prop-content-length: 111 Content-length: 111 K 7 svn:log V 11 Empty dirs. K 10 svn:author V 5 durin K 8 svn:date V 27 2008-10-07T22:49:41.118037Z 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: 108 Content-length: 108 K 7 svn:log V 9 Add alpha K 10 svn:author V 5 durin K 8 svn:date V 27 2008-10-07T23:23:02.991743Z PROPS-END Node-path: trunk/alpha Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 12 Text-content-md5: 3c72ebf8bbd7fa88b1fdcee5398b5a17 Content-length: 22 PROPS-END file: alpha Revision-number: 3 Prop-content-length: 107 Content-length: 107 K 7 svn:log V 8 Add beta K 10 svn:author V 5 durin K 8 svn:date V 27 2008-10-07T23:28:22.651398Z PROPS-END Node-path: trunk/beta Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 13 Text-content-md5: 981d1eb5fd0bbe05354c292105944863 Content-length: 23 PROPS-END Data of beta