fix(blurhash): Use preview API to generate the previews

[artonge]

1. feat(previews): Support in memory preview request
This allows callers to use the API without increasing the disk usage.

2. fix(blurhash): Use preview API to generate the previews
This allows to benefit from all the checks done by the API.
This also used the newly introduced cacheResult argument to limit disk usage.

• Fix github.com/[Bug]: cron.php crashes with memory exception in GenerateBlurhashMetadata.php because of large images #52063

[skjnldsv]

One comment otherwise good!

[come-nc]

psalm:update-baseline needed

[miaulalala]

/backport to stable31

[miaulalala]

/backport to stable30

[miaulalala]

/backport to stable29

[susnux]

🧪 💥

1. Test\Preview\GeneratorTest::testGetNewPreview
   Expectation failed for method name is "putContent" when invoked 1 time(s).
   Method was expected to be called 1 times, actually called 0 times.

[skazi0]

@artonge did you test this with 'enable_previews' => false ?

[artonge]

@artonge did you test this with 'enable_previews' => false ?

No. By reading the code, I assume this would skip blurhash generation. Which would be expected as blurhashes are a kind of preview.

[skazi0]

@artonge did you test this with 'enable_previews' => false ?

No. By reading the code, I assume this would skip blurhash generation. Which would be expected as blurhashes are a kind of preview.

It doesn't generate blurhash but also logs:

"Exception":"OCP\\\\Files\\\\NotFoundException","Message":"Previews disabled","Code":0,
"Trace":[
{"file":"/var/www/nextcloud/lib/private/PreviewManager.php","line":157,"function":"throwIfPreviewsDisabled","class":"OC\\\\PreviewManager","type":"->"},
{"file":"/var/www/nextcloud/lib/private/Blurhash/Listener/GenerateBlurhashMetadata.php","line":71,"function":"getPreview","class":"OC\\\\PreviewManager","type":"->"},
{"file":"/var/www/nextcloud/lib/private/EventDispatcher/ServiceEventListener.php","line":68,"function":"handle","class":"OC\\\\Blurhash\\\\Listener\\\\GenerateBlurhashMetadata","type":"->"},
{"file":"/var/www/nextcloud/3rdparty/symfony/event-dispatcher/EventDispatcher.php","line":220,"function":"__invoke","class":"OC\\\\EventDispatcher\\\\ServiceEventListener","type":"->"},
{"file":"/var/www/nextcloud/3rdparty/symfony/event-dispatcher/EventDispatcher.php","line":56,"function":"callListeners","class":"Symfony\\\\Component\\\\EventDispatcher\\\\EventDispatcher","type":"->"},
{"file":"/var/www/nextcloud/lib/private/EventDispatcher/EventDispatcher.php","line":67,"function":"dispatch","class":"Symfony\\\\Component\\\\EventDispatcher\\\\EventDispatcher","type":"->"},
{"file":"/var/www/nextcloud/lib/private/EventDispatcher/EventDispatcher.php","line":79,"function":"dispatch","class":"OC\\\\EventDispatcher\\\\EventDispatcher","type":"->"},
{"file":"/var/www/nextcloud/lib/private/FilesMetadata/FilesMetadataManager.php","line":100,"function":"dispatchTyped","class":"OC\\\\EventDispatcher\\\\EventDispatcher","type":"->"},
{"file":"/var/www/nextcloud/lib/private/FilesMetadata/Job/UpdateSingleMetadata.php","line":43,"function":"refreshMetadata","class":"OC\\\\FilesMetadata\\\\FilesMetadataManager","type":"->"},
{"file":"/var/www/nextcloud/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OC\\\\FilesMetadata\\\\Job\\\\UpdateSingleMetadata","type":"->"},
{"file":"/var/www/nextcloud/lib/public/BackgroundJob/QueuedJob.php","line":43,"function":"start","class":"OCP\\\\BackgroundJob\\\\Job","type":"->"},
{"file":"/var/www/nextcloud/lib/public/BackgroundJob/QueuedJob.php","line":29,"function":"start","class":"OCP\\\\BackgroundJob\\\\QueuedJob","type":"->"},
{"file":"/var/www/nextcloud/cron.php","line":170,"function":"execute","class":"OCP\\\\BackgroundJob\\\\QueuedJob","type":"->"}
]

IMO, this should be caught in GenerateBlurhashMetadata and ignored silently.