The initial office preview implementation converted an office document with LibreOffice to PDF, used ImageMagick to extract the first page as JPEG, and passed it OC_Image.
https://github.com/nextcloud/server/pull/10198 changed the implementation to use PNG rather than PDF. OC_Image can use a PNG as a preview right away, so the ImageMagick step is unnecessary.
The registration code was updated to not ask ImageMagick if PDF is supported, as PDFs are no longer used to create office document previews.
Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
LibreOffice only allows one invocation per user profile.[^1]
The office provider set the user profile to /tmp/owncloud-instanceid and therefore only one invocation per instance is allowed. This was introduced a while ago, yet it's unclear if this was intentionally or just a side effect.[^2]
The limitation on one invocation leads to the situation that the preview generation only works for a couple of files if you upload a whole folder of emf or word files.
This commit removes the limitation by using a new user profile for each preview. That's done by using instance id plus file id as postfix for getTemporaryFolder.
This has some drawbacks:
- Overload protection: If you upload 100 emf files, you may end up with 100 LibreOffice invocations. Though, you can use preview_concurrency_new to limit the number of previews that can be generated concurrently when php-sysvsem is available.
- New profile: I assume it takes a few bits to generate a fresh LibreOffice user profile. It appears that there is no way to ask LibreOffice to not create a profile and just work with the defaults. The profile will be cleaned after use by our temp manager.
- Remove the configuration option preview_office_cl_parameters: This is not strictly necessary yet, but if you set the configuration option, the generated path for the user profile is also missing. The configuration option is not well documented (e.g., it's unclear that the last option needs to be --outdir) and actually, there should be no reason to change it after all.
[^1]: https://wiki.documentfoundation.org/UserProfile
[^2]: https://github.com/owncloud/core/pull/9784
Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
user_usage_report keeps a counter for files read.
The app uses
- OC_Filesystem::read hook
- Event listener (the legacy one) for IPreview::EVENT
Request for previews do not trigger the hook, hence the additional event listener.
The thumbnails for a list or grid view should not count, so we need the width and height.
Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
We use a forked version of getID3 to read embedded images from mp3 files to use them as previews.
If the library is unable to extract a image or fails on something different we should handle it properly.
Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
getCachedPreview used to call `getFile`, and this calls `getDirectoryListing` (or underlying function that list directory) to find the file. This was done for every preview spec.
Now, this is done only once at the beginning of the loop, and the array is just iterated when needed to find the correct entry.
Signed-off-by: Glandos <bugs-github@antipoul.fr>
The use of `exec` will spawn a shell, using `/bin/sh` on POSIX platforms. But in restricted environment, such as AppArmor, this means giving execution to `/bin/sh`, which renders the execution restriction quite useless.
Using an array with `proc_open` reduces this, and paved the way for file streaming instead of temporary file.
Signed-off-by: Glandos <bugs-github@antipoul.fr>
If the maximum preview generated gives some kind of invalid IImage, it's dimentions and filename can be set to zero.
And then later we do a division by zero to keep the aspect ratio of the previews.
Signed-off-by: Thomas Citharel <tcit@tcit.fr>
