How to store an Intervention image in gridfs/mongodb? - php

Question

In my application there is a call which might request a resized version of the image. In the case when it is resized I want to store the resized version long-term onto gridfs, exactly like the other images.
I can easily resize the image and return it using Intervention (http://image.intervention.io/getting_started/introduction) however it seems to be that it's not possible to store the resized image to the DB without saving it to a temporary file.
In particular this fails:
$bucket = DB::getMongoDB()->selectGridFSBucket();
$stream = $bucket->openDownloadStreamByName($name);
$document = $bucket->getFileDocumentForStream($stream);
$metadata = $document['metadata']->getArrayCopy();
$file = stream_get_contents($stream);
$img = Image::cache(function($image) use ($file){
$image->make($file);
}, 60, true);
$img->resize($width, $height, function ($constraint) {
$constraint->aspectRatio();
$constraint->upsize();
});
$bucket->uploadFromStream($randomName, $img, ['metadata' => $metadata]);
The call to uploadFromStream fails saying: Expected $source to have type "resource" but found "Intervention\Image\CachedImage".
Trying to change:
$bucket->uploadFromStream($randomName, $img, ['metadata' => $metadata]);
to:
$bucket->uploadFromStream($randomName, $img->stream('png'), ['metadata' => $metadata]);
Leads to the same error only that the type changes from Intevention\Image\CachedImage to GuzzleHttp\Psr7\Stream.
Now I could do:
$img->save('/tmp/test.png')
$stream = fopen('/tmp/test.png')
$bucket->uploadFromStream($randomName, $stream, ['metadata' => $metadata]);
but this is abysmally bad because:
it has a race condition. I would need to ensure the filename used is unique otherwise it might be overwritten
it writes to disk which means it's going to be way slower than just using an in-memory stream
it writes to disk which means it deteriorates more. Consider that this write is completely useless so I'd avoid using it. It can be triggered quite often.
So, is there a way to save the resized image to GridFS without passing throught the disk?

Answer 1

I found a solution: you can obtain the binary data as a string using $img->response()->content() and then instead of using uploadFromStream you can use openUploadStream and write the data.
The full working solution would be:
$bucket = DB::getMongoDB()->selectGridFSBucket();
$stream = $bucket->openDownloadStreamByName($name);
$document = $bucket->getFileDocumentForStream($stream);
$metadata = $document['metadata']->getArrayCopy();
$file = stream_get_contents($stream);
$img = Image::cache(function($image) use ($file){
$image->make($file);
}, 60, true);
$img->resize($width, $height, function ($constraint) {
$constraint->aspectRatio();
$constraint->upsize();
});
$stream = $bucket->openUploadStream($randomName, ['metadata' => $metadata]);
fwrite($stream, $img->response()->content());
fclose($stream);