Stop cron after update

[nickvergessen]

Ref #4978

Need a way to refresh the OC\Config::$cache array or to ignore it.

The best option I see atm is to pipe a method purgeConfigCache through AllConfig > SystemConfig > Config
The problem is currently we don't re-read the config file, so all this checking is useless...

[mention-bot]

@nickvergessen, thanks for your PR! By analyzing the history of the files in this pull request, we identified @butonic, @icewind1991 and @jakobsack to be potential reviewers.

[blizzz]

The best option I see atm is to pipe a method purgeConfigCache through AllConfig > SystemConfig > Config

Agreed, the alternatives that come to my mind do not look better at all.

[nickvergessen]

A second idea I just had was to automatically invalidate the cache every x seconds, so when a config is get/set later than x seconds, the data is refetched before.

The main problem I start seeing now is, that when two processes run for quite some time, and both write a config value, the later one will overwrite the config value of the first write with the old value it read... time to get rid of the stupid config file :/

[patschi]

What about checking for any file modification of the config file itself? Like filemtime or any simple hash function like md5?

[nickvergessen]

Yeah however, then we should do it on every write and save the md5 in memcache or something

[blizzz]

A second idea I just had was to automatically invalidate the cache every x seconds, so when a config is get/set later than x seconds, the data is refetched before.

The main problem I start seeing now is, that when two processes run for quite some time, and both write a config value, the later one will overwrite the config value of the first write with the old value it read... time to get rid of the stupid config file :/

Paradise for race conditions. Even without the latter scenario.

[MorrisJobke]

What is the status of this?

[MorrisJobke]

I'm pretty sure, that this will not work, because the config is already loaded and will still hold the old version.

[codecov]

Codecov Report

Merging #5172 into master will increase coverage by 2.43%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #5172      +/-   ##
============================================
+ Coverage     51.71%   54.14%   +2.43%     
+ Complexity    25672    22286    -3386     
============================================
  Files          1634     1379     -255     
  Lines         95813    85346   -10467     
  Branches       1382     1321      -61     
============================================
- Hits          49550    46212    -3338     
+ Misses        46263    39134    -7129

Impacted Files	Coverage Δ	Complexity Δ
cron.php	0% <0%> (ø)	0 <0> (ø)	⬇️
...are/Security/Exceptions/AppNotEnabledException.php	0% <0%> (-100%)	1% <0%> (ø)
...ware/Security/Exceptions/NotConfirmedException.php	0% <0%> (-100%)	1% <0%> (ø)
apps/workflowengine/lib/Check/RequestUserAgent.php	0% <0%> (-96.43%)	10% <0%> (-4%)
lib/private/Preview/GeneratorHelper.php	0% <0%> (-80%)	5% <0%> (ø)
apps/files_sharing/lib/Helper.php	20.35% <0%> (-58.96%)	38% <0%> (+27%)
apps/files/appinfo/app.php	43.47% <0%> (-56.53%)	0% <0%> (ø)
apps/comments/lib/Activity/Listener.php	24% <0%> (-56.4%)	10% <0%> (ø)
core/Command/Maintenance/Mimetype/UpdateJS.php	0% <0%> (-52.64%)	13% <0%> (ø)
lib/private/Template/JSResourceLocator.php	0% <0%> (-50.91%)	22% <0%> (-1%)
... and 1307 more

[MorrisJobke]

We splitted this one up into #9561 and #9562 because the approach here is not going to work.