mirrors/git-annex
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity Actions

comment

Browse source
This commit is contained in:
Joey Hess 2022-07-19 18:10:45 -04:00
parent d832a7c211
commit c933b0074f
No known key found for this signature in database
GPG key ID: DB12DB0FF05F8F38
1 changed files with 24 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

24
doc/todo/registerurl__58___do_changes_in_journal___34__in_place__34____63__/comment_20_fc54794546e8e14b31aa063d93c328de._comment Normal file
View file

@ -0,0 +1,24 @@
[[!comment format=mdwn
username="joey"
subject="""comment 20"""
date="2022-07-19T22:03:07Z"
content="""
Oh, even simpler -- let the journal assume that all the files are a series of
lines. Which they always will be, I'm sure. Then:
When appending to a journal file, first read the last byte.
If it's not a newline, then seek back to the previous newline, to discard
a previous interrupted append.
When reading from a journal file, similarly check the last byte and if not a
newline, discard back to the previous newline.
Reading would not need any locking either. A read that happened while an
append was in progress and read an incomplete line would discard it.
Old versions of git-annex would not get confused by NULs with this method,
the format of the branch files is not changed. So it's significantly safer,
but not fully since old git-annex versions would not deal well with an
interrupted append. So it would still be good to upgrade the repo version
in a way that prevents an old git-annex process from lingering around.
"""]]