Creating an image without storing it as a local file

Question

Here\'s my situation - I want to create a resized jpeg image from a user uploaded image, and then send it to S3 for storage, but am looking to avoid writing the resized jpeg

Answer 1

I encounter the same problem, using openstack object store and php-opencloud library.

Here is my solution, which does not use the ob_start and ob_end_clean function, but store the image in memory and in temp file. The size of the memory and the temp file may be adapted at runtime.

// $image is a resource created by gd2
var_dump($image); // resource(2) of type (gd)

// we create a resource in memory + temp file 
$tmp = fopen('php://temp', '$r+');

// we write the image into our resource
\imagejpeg($image, $tmp);

// the image is now in $tmp, and you can handle it as a stream
// you can, then, upload it as a stream (not tested but mentioned in doc http://docs.aws.amazon.com/aws-sdk-php/v2/guide/service-s3.html#uploading-from-a-stream)
$s3->putObject(array(
   'Bucket' => $bucket,
   'Key'    => 'data_from_stream.txt',
   'Body'   => $tmp
));

// or, for the ones who prefers php-opencloud :
$container->createObject([
    'name'  => 'data_from_stream.txt',
    'stream' => \Guzzle\Psr7\stream_for($tmp),
    'contentType' => 'image/jpeg'
]);

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About php://temp (from the official documentation of php):

php://memory and php://temp are read-write streams that allow temporary data to be stored in a file-like wrapper. The only difference between the two is that php://memory will always store its data in memory, whereas php://temp will use a temporary file once the amount of data stored hits a predefined limit (the default is 2 MB). The location of this temporary file is determined in the same way as the sys_get_temp_dir() function.

The memory limit of php://temp can be controlled by appending /maxmemory:NN, where NN is the maximum amount of data to keep in memory before using a temporary file, in bytes.