Generation of zip file in php is slow - php

Question

I have a script which put images, floor plans and video into a zip file, it can reach 500mb easily but most of the time average is 150mb.
The generation of the zip file is extremely slow and i can't figurate why. Is there any tips to improve my script?
It took me 10 min to create the zip file in the server just for 100mb.
if( !empty( $files ) ){
$random_nbr = mt_rand(1,5646866662);
$path = 'webroot/img/tmp/' . $random_nbr;
if (!file_exists(\Cake\Core\Configure::read('pathTo') . 'webroot/img/tmp')) {
mkdir(\Cake\Core\Configure::read('pathTo') . 'webroot/img/tmp', 0777, true);
}
$destination = \Cake\Core\Configure::read('pathTo') . $path . '_media.zip';
$media_url = \Cake\Core\Configure::read('websiteUrl') . '/img/tmp/' . $random_nbr . '_media.zip';
$zip = new ZipArchive();
$zip->open( $destination, ZIPARCHIVE::CREATE | ZIPARCHIVE::OVERWRITE );
// Photos
if (isset($files['photos'])):
foreach( $files['photos'] as $f ){
$context = stream_context_create(array('http' => array('header'=>'Connection: close\r\n')));
// Original
$parsed_file = $f['original_file'];
$download_file = file_get_contents($parsed_file, false,$context);
$zip->addFromString('photos/original/' . basename($parsed_file), $download_file);
// Web with or without a watermark
$web = $this->Images->state_image(1270, $f['id'], 0, '');
$web = $web->response('jpg');
$zip->addFromString('photos/web/' . $f['name'], $web);
// High Res Web with or without a watermark
$web = $this->Images->state_image(2000, $f['id'], 0, '');
$web = $web->response('jpg');
$zip->addFromString('photos/high_res_web/' . $f['name'], $web);
}
endif;
// Floor Plan
if (isset($files['floorplan'])):
foreach( $files['floorplan'] as $f ){
$parsed_file = $f['original_file'];
$context = stream_context_create(array('http' => array('header'=>'Connection: close\r\n')));
$download_file = file_get_contents($parsed_file, false,$context);
$zip->addFromString('floorplan/' . basename($parsed_file), $download_file);
}
endif;
// Video
if (isset($files['video'])):
foreach( $files['video'] as $f ){
$parsed_file = $f['original_file'];
$context = stream_context_create(array('http' => array('header'=>'Connection: close\r\n')));
$download_file = file_get_contents($parsed_file, false,$context);
$zip->addFromString('floorplan/' . basename($parsed_file), $download_file);
}
endif;
$zip->close();
echo $media_url;
die();
}

Answer 1

Outside of dedicated hardware, there probably is not much you'll be able to do to speed up the actual zipping process. You could try exec()'ing the system zip utility rather than using PHP to do it, but that may not change things.
What you can do though (if the host allows it) is background the process and provide a status page so users can see how long until their file is ready. I've done this in the past for similar problems.
What I did was have a table in the database that would store information about the zip file to be created, and a list of all the files to be added to the zip file. Then I'd exec() off a background script with the ID of the newly created DB record.
The background process would read the DB for all the details and begin creating the zip file. Periodically it would update the DB with a % complete. When finished it'd update the DB with the file system path to the newly generated zip file.
Then I had another page for the end user that displayed a progress bar. The page would periodically make an Ajax request to the server to get the new % complete for the file and update the bar accordingly. When the file was complete it would change to a download link for them to begin downloading the file.
There was another cron job process that would periodically go through and delete all the temp files older than 5 days. If users needed the file again they had to have it re-generated.