FileSnapshot.notRacyClean() assumed a worst case filesystem timestamp
resolution of 2.5 sec (FAT has a resolution of 2 sec). Instead measure
timestamp resolution to avoid unnecessary IO caused by false positives
in detecting the racy git problem caused by finite filesystem timestamp
resolution [1].
Cache the measured resolution per FileStore since timestamp resolution
depends on the respective filesystem type. If timestamp resolution
cannot be measured or fails due to an exception fallback to the worst
case FAT timestamp resolution and avoid caching this value.
Add a 10% safety margin in FileSnapshot.notRacyClean(), though running
FsTest.testFsTimestampResolution() 1000 times which is not using a
safety margin didn't fail on Mac using APFS and Java 8, 11, 12.
Measured Java file timestamp resolution: [2]
[1] https://github.com/git/git/blob/master/Documentation/technical/racy-git.txt
[2] https://docs.google.com/spreadsheets/d/1imy0y6WmRqBf0kjCxzxj2X7M50eIVfa7oaUIzEOHmjo
Bug: 546891
Change-Id: I493f3b57b6b306285ffa7d392339d253e5966ab8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Do not reload packfiles when their associated filesnapshot is not
modified on disk compared to the one currently stored in memory.
Fix the regression introduced by fef78212 which, in conjunction with
core.trustfolderstats = false, caused any lookup of objects inside
the packlist to loop forever when the object was not found in the pack
list.
Bug: 546190
Change-Id: I38d752ebe47cefc3299740aeba319a2641f19391
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
The prune method did not delete empty fanout directories when loose
objects moved to a new pack file but only when loose unreferenced
objects were pruned.
Change-Id: Ia068f4914c54d9cf9f40b75e8ea50759402b5000
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Due to finite filesystem timestamp resolution the last modified
timestamp of files cannot detect file changes which happened in the
immediate past (less than one filesystem timer tick ago).
Read and consider file size also, so that differing file size can help
to more accurately detect file changes without reading the file content.
Use bulk read to avoid multiple stat calls to retrieve file attributes.
Change-Id: I974288fff78ac78c52245d9218b5639603f67a46
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
ProtocolV2Parser explains:
// TODO(ifrade): This validation should be done after the
// protocol parsing. It is not a protocol problem asking for an
// unexisting ref and we wouldn't need the ref database here.
Do so. This way all ref database accesses are in one place, in the
UploadPack class.
No user-visible change intended --- this is just to make the code
easier to manipulate.
Change-Id: I68e87dff7b9a63ccc169bd0836e8e8baaf5d1048
Signed-off-by: Jonathan Nieder <jrn@google.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
when multiple match options are given in git describe the result must
not depend on the order of the match options. JGit wrongly picked the
first match using the match options in the order they were defined. Fix
this by concatenating the streams of matching tags for all match options
and then choosing the first match on the concatenated stream sorted in
tie break order.
See https://git-scm.com/docs/git-describe#git-describe---matchltpatterngt
Change-Id: Id01433d35fa16fb4c30526605bee041ac1d954b2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Correct behaviour as git 1.7.1.1 is to resolve tie-breakers to choose
the most recent tag.
https://github.com/git/git/blob/master/Documentation/RelNotes/1.7.1.1.txt:
* "git describe" did not tie-break tags that point at the same commit
correctly; newer ones are preferred by paying attention to the
tagger date now.
Bug: 538610
Change-Id: Ib0b2a301997bb7f75935baf7005473f4de952a64
Signed-off-by: Håvard Wall <haavardw@gmail.com>
Matthias Sohn
Luca Milanesio
Jonathan Nieder
Håvard Wall