Mercurial > hgsubversion
view tests/fixtures/subdir_is_file_prefix.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 | c6388ed0ec0a |
children |
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SVN-fs-dump-format-version: 2 UUID: 924a052a-5e5a-4a8e-a677-da5565bec340 Revision-number: 0 Prop-content-length: 56 Content-length: 56 K 8 svn:date V 27 2011-03-04T12:33:29.342045Z PROPS-END Revision-number: 1 Prop-content-length: 123 Content-length: 123 K 7 svn:log V 22 Create directory flaf. K 10 svn:author V 6 danchr K 8 svn:date V 27 2011-03-04T12:34:00.349950Z PROPS-END Node-path: flaf Node-kind: dir Node-action: add Prop-content-length: 10 Content-length: 10 PROPS-END Revision-number: 2 Prop-content-length: 138 Content-length: 138 K 7 svn:log V 37 Create the file flaf.txt within flaf. K 10 svn:author V 6 danchr K 8 svn:date V 27 2011-03-04T12:45:01.701033Z PROPS-END Node-path: flaf/flaf.txt Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 15 Text-content-md5: 8c0059c8f7998e8003836b8e8fcb74d7 Text-content-sha1: b7d680bc5411f46395c4ef267001e1a307d7b0d5 Content-length: 25 PROPS-END Goodbye world.