Mercurial > hgsubversion
view tests/fixtures/tag_deletion_tag_branch.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 | e1b23a6ca093 |
| children |
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SVN-fs-dump-format-version: 2 UUID: eef88803-8121-4c2d-a584-b15733364666 Revision-number: 0 Prop-content-length: 56 Content-length: 56 K 8 svn:date V 27 2009-05-30T18:12:25.144447Z PROPS-END Revision-number: 1 Prop-content-length: 103 Content-length: 103 K 7 svn:log V 4 init K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:13:59.514904Z 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 Node-path: trunk/alpha Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 18 Text-content-md5: 207dd96a2baf1c1bfe2728ea67da7e37 Content-length: 28 PROPS-END content of alpha. Node-path: trunk/beta Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 17 Text-content-md5: 868f9a1cd3f678461c02fee4d8b7d44c Content-length: 27 PROPS-END content of beta. Node-path: trunk/delta Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 18 Text-content-md5: cee60c4f880a73eea79fac90547d0142 Content-length: 28 PROPS-END content of delta. Node-path: trunk/gamma Node-kind: file Node-action: add Prop-content-length: 10 Text-content-length: 18 Text-content-md5: 865ce111ce132951995b1b7b63f0f2dc Content-length: 28 PROPS-END content of gamma. Revision-number: 2 Prop-content-length: 105 Content-length: 105 K 7 svn:log V 6 remove K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:14:10.610589Z PROPS-END Node-path: trunk/delta Node-action: delete Revision-number: 3 Prop-content-length: 114 Content-length: 114 K 7 svn:log V 14 trunk at 2 tag K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:14:43.562547Z PROPS-END Node-path: tags/trunk_at_2 Node-kind: dir Node-action: add Node-copyfrom-rev: 2 Node-copyfrom-path: trunk Revision-number: 4 Prop-content-length: 115 Content-length: 115 K 7 svn:log V 15 branch of trunk K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:15:06.771293Z PROPS-END Node-path: branches/from_2 Node-kind: dir Node-action: add Node-copyfrom-rev: 3 Node-copyfrom-path: trunk Revision-number: 5 Prop-content-length: 106 Content-length: 106 K 7 svn:log V 7 Untag 2 K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:15:30.999412Z PROPS-END Node-path: tags/trunk_at_2 Node-action: delete Revision-number: 6 Prop-content-length: 114 Content-length: 114 K 7 svn:log V 14 make a new tag K 10 svn:author V 5 durin K 8 svn:date V 27 2009-05-30T18:16:01.917326Z PROPS-END Node-path: tags/new_tag Node-kind: dir Node-action: add Node-copyfrom-rev: 5 Node-copyfrom-path: branches/from_2