view tests/fixtures/truncatedhistory.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 3b60f223893a
children
line wrap: on
line source

SVN-fs-dump-format-version: 2

UUID: a632509c-657a-43d2-ae0b-85387476b20e

Revision-number: 0
Prop-content-length: 56
Content-length: 56

K 8
svn:date
V 27
2008-11-11T19:00:25.260082Z
PROPS-END

Revision-number: 1
Prop-content-length: 114
Content-length: 114

K 7
svn:log
V 12
init project
K 10
svn:author
V 7
pmezard
K 8
svn:date
V 27
2008-11-11T19:00:25.322759Z
PROPS-END

Node-path: project1
Node-kind: dir
Node-action: add
Prop-content-length: 10
Content-length: 10

PROPS-END


Node-path: project2
Node-kind: dir
Node-action: add
Prop-content-length: 10
Content-length: 10

PROPS-END


Revision-number: 2
Prop-content-length: 106
Content-length: 106

K 7
svn:log
V 5
add a
K 10
svn:author
V 7
pmezard
K 8
svn:date
V 27
2008-11-11T19:00:26.173269Z
PROPS-END

Node-path: project1/a
Node-kind: file
Node-action: add
Prop-content-length: 10
Text-content-length: 2
Text-content-md5: 60b725f10c9c85c70d97880dfe8191b3
Content-length: 12

PROPS-END
a


Revision-number: 3
Prop-content-length: 117
Content-length: 117

K 7
svn:log
V 15
rename project1
K 10
svn:author
V 7
pmezard
K 8
svn:date
V 27
2008-11-11T19:00:29.152593Z
PROPS-END

Node-path: project2/trunk
Node-kind: dir
Node-action: add
Node-copyfrom-rev: 2
Node-copyfrom-path: project1
Prop-content-length: 34
Content-length: 34

K 13
svn:mergeinfo
V 0

PROPS-END


Node-path: project1
Node-action: delete


Revision-number: 4
Prop-content-length: 106
Content-length: 106

K 7
svn:log
V 5
add b
K 10
svn:author
V 7
pmezard
K 8
svn:date
V 27
2008-11-11T19:00:30.178261Z
PROPS-END

Node-path: project2/trunk/b
Node-kind: file
Node-action: add
Prop-content-length: 10
Text-content-length: 2
Text-content-md5: 3b5d5c3712955042212316173ccf37be
Content-length: 12

PROPS-END
b