Mercurial > hgsubversion
view tests/fixtures/copyafterclose.svndump @ 1233:0d0132cba155
editor: fix edge case with in memory file-store size limit
There are a few cases where we will set a single file into to the
editor's FileStore object more than once. Notably, for copied and
then modified files, we will set it at least twice. Three times if
editing fails (which it can for symlinks).
If we pass the in-memory storage limit in between the first (or second
if editing fails) time we set the file and the last time we set the
file, we will write the data to the in memory store the first time and
the file store the last time. We didn't remove it form the in-memory
store though, and we always prefer reading from the in-memory store.
This means we can sometimes end up with the wrong version of a file.
This is fairly unlikely to happen in normal use since you need to hit
the memory limit between two writes to the store for the same file.
We only write a file multiple times if a) the file (and not one of
it's parent directories) is copied and then modified or b) editing
fails. From what I can tell, it's only common for editing to fail for
symlinks, and they ten to be relatively small data that is unlikely to
push over the limit. Finally, the default limit is 100MB which I
would expect to be most often either well over (source code) or well
under (binaries or automated changes) the size of the changes files in
a single commit.
The easiest way to reproduce this is to set the in-memory cache size
to 0 and then commit a copied and modified symlink. The empty-string
version from the failed editing will be the one that persists. I
happened to stumble upon this while trying (and failing) to test a
bug-fix for a related bug with identical symptoms (empty simlink). I
have seen this in the wild, once, but couldn't reproduce it at the
time. The repo in question is quite large and quite active, so I am
quite confident in my estimation that this is a real, but very rare,
problem.
The test changes attached to this was mneant to test a related bug,
but turned out not to actually cover the bug in question. They did
trigger this bug though, and are worthwhile to test, so I kept them.
| author | David Schleimer <dschleimer@fb.com> |
|---|---|
| date | Mon, 07 Apr 2014 17:51:59 -0700 |
| parents | ba8485b9fee0 |
| children |
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SVN-fs-dump-format-version: 2 UUID: 288797d9-b527-4683-aa49-2eb9e084ffad Revision-number: 0 Prop-content-length: 56 Content-length: 56 K 8 svn:date V 27 2014-04-03T22:42:41.334418Z PROPS-END Revision-number: 1 Prop-content-length: 108 Content-length: 108 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.393547Z K 7 svn:log V 3 btt 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: 123 Content-length: 123 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.442353Z K 7 svn:log V 17 Add file and dir. PROPS-END Node-path: trunk/dir Node-kind: dir Node-action: add Prop-content-length: 10 Content-length: 10 PROPS-END Node-path: trunk/dir/file Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 7 Text-content-md5: 5f2a436c7d4aa15dfbdca7b303fcae35 Text-content-sha1: 391157987cb6fefff86fd89353356611ea621906 Content-length: 17 PROPS-END trunk1 Node-path: trunk/file Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 7 Text-content-md5: 5f2a436c7d4aa15dfbdca7b303fcae35 Text-content-sha1: 391157987cb6fefff86fd89353356611ea621906 Content-length: 17 PROPS-END trunk1 Revision-number: 3 Prop-content-length: 112 Content-length: 112 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.504478Z K 7 svn:log V 7 Branch. PROPS-END Node-path: branches/test Node-kind: dir Node-action: add Node-copyfrom-rev: 2 Node-copyfrom-path: trunk Revision-number: 4 Prop-content-length: 121 Content-length: 121 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.549176Z K 7 svn:log V 15 edit on branch. PROPS-END Node-path: branches/test/dir/file Node-kind: file Node-action: change Text-content-length: 8 Text-content-md5: ed787ace107676c1dfcced2ae527df92 Text-content-sha1: b8486c4feca589a4237a1ee428322d7109ede12e Content-length: 8 branch1 Node-path: branches/test/file Node-kind: file Node-action: change Text-content-length: 8 Text-content-md5: ed787ace107676c1dfcced2ae527df92 Text-content-sha1: b8486c4feca589a4237a1ee428322d7109ede12e Content-length: 8 branch1 Revision-number: 5 Prop-content-length: 119 Content-length: 119 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.600193Z K 7 svn:log V 13 edit on trunk PROPS-END Node-path: trunk/dir/file Node-kind: file Node-action: change Text-content-length: 7 Text-content-md5: 28d0a7e7ef2864416b7a9398623e4d09 Text-content-sha1: 91454e2d3487f712490f17481157e389c11a6fe0 Content-length: 7 trunk2 Node-path: trunk/file Node-kind: file Node-action: change Text-content-length: 7 Text-content-md5: 28d0a7e7ef2864416b7a9398623e4d09 Text-content-sha1: 91454e2d3487f712490f17481157e389c11a6fe0 Content-length: 7 trunk2 Revision-number: 6 Prop-content-length: 118 Content-length: 118 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.650888Z K 7 svn:log V 12 Close trunk. PROPS-END Node-path: trunk Node-action: delete Revision-number: 7 Prop-content-length: 134 Content-length: 134 K 10 svn:author V 10 dschleimer K 8 svn:date V 27 2014-04-03T22:42:41.757761Z K 7 svn:log V 28 copy from trunk before close PROPS-END Node-path: branches/test/dir Node-kind: dir Node-action: delete Node-path: branches/test/dir Node-kind: dir Node-action: add Node-copyfrom-rev: 5 Node-copyfrom-path: trunk/dir Node-path: branches/test/file Node-kind: file Node-action: delete Node-path: branches/test/file Node-kind: file Node-action: add Node-copyfrom-rev: 5 Node-copyfrom-path: trunk/file Text-copy-source-md5: 28d0a7e7ef2864416b7a9398623e4d09 Text-copy-source-sha1: 91454e2d3487f712490f17481157e389c11a6fe0