* introduces a new IRootMountProvider to register mount points inside the root storage
* adds a AppdataPreviewObjectStoreStorage to handle the split between preview folders and bucket number
Ref #22033
Signed-off-by: Morris Jobke <hey@morrisjobke.de>
* `php occ preview:repair` - a preview migration tool that moves existing previews into the new location introduced with #19214
* moves `appdata_INSTANCEID/previews/FILEID` to `appdata_INSTANCEID/previews/0/5/8/4/c/e/5/FILEID`
* migration tool can be stopped during migration via `CTRL+C` - it then finishes the current folder (with the previews of one file) and stops gracefully
* if a PHP memory limit is set in the `php.ini` then it will stop automatically once it has less than 25 MiB memory left (this is to avoid hard crashes in the middle of a migration)
* the tool can be used during operation - possible drawbacks:
* there is the chance of a race condition that a new preview is generated in the moment the folder is already migrated away - so the old folder with the newly cached preview is deleted and one cached preview needs to be re-generated
* there is the chance of a race condition during access of a preview while it is migrated to the other folder - then no preview can be shown and results in a 404 (as of now this is an accepted risk)
Signed-off-by: Morris Jobke <hey@morrisjobke.de>
Else the number of files can grow very large very quickly in the preview
folder. Esp on large systems.
This generates the md5 of the fileid. And then creates folders of the
first 7 charts. In that folder is then a folder with the fileid. And
inside there are the previews.
Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>
Morris Jobke
Christoph Wurst
Roeland Jago Douma