Memory leaks AWS S3 SDK PHP - php

Question

I need to download thousands of images from an S3 bucket. I'm using the PHP SDK for AWS S3, but I can't find a way to remove the memory it's using when downloading the images.
$keyname = 'XXXXXXXXXX';
$bucket = 'XXXXXXXXXX';
$region = 'eu-west-1';
$credentials = new Aws\Credentials\Credentials('XXXXXXXXXX', 'XXXXXXXXXX');
$s3 = new Aws\S3\S3Client([
'version' => 'latest',
'region' => $region,
'credentials' => $credentials,
]);
$idDownloadedImages = array();
do {
$files = $this->check_new_images();
if ( !empty( $files ) ) {
foreach ( $files as $file ) {
$UrlMedia = basename( $file->UrlMedia );
$pathFile = $pathToPlugin . 'images/' . $UrlMedia;
$object = $keyname . $UrlMedia;
try {
// Get the object.
$result = $s3->getObject([
'Bucket' => $bucket,
'Key' => $object,
'SaveAs' => $pathFile,
]);
//gc_collect_cycles();
//xdebug_debug_zval('result');
$idDownloadedImages[] = $file->idMedia;
} catch ( S3Exception $e ) {
$errorCode = '(Error Code: ' . $e->getStatusCode() . ') ' . $e->getAwsErrorMessage();
}
//unset($result);
$result['Body']->__destruct();
}
$idDownloadedImages = implode( ',', $idDownloadedImages );
$wpdb->query( 'UPDATE wp_icat_Media
SET error=0
WHERE idMedia IN (' . $idDownloadedImages .')' );
$idDownloadedImages = array();
}
} while ( $this->check_new_images() );
I have tried to force the PHP garbage collector every time I download an image, to do a set() of $result and $idDownloadedImages and even to do $result['Body']->__destruct(), but I still don't know why it stores the images in memory.
Memory is only freed by forcing the gc_collect_cycles() at the end of the script.

Answer 1

From the documentation, Amazon recommends calling gc_collect_cycles on the before_upload event.
Here is the sample code:
$uploader = new MultipartUploader($client, $source, [
'bucket' => 'your-bucket',
'key' => 'your-key',
'before_upload' => function(\Aws\Command $command) {
gc_collect_cycles();
}
]);