Google Cloud Storage get temp filename (using fopen('php://temp')) - php

Question

Similar question asked here a few years ago but with no answer:
Get path of temp file created via fopen('php://temp')
I am using Google Cloud Storage to download a number of large files in parallel and then upload them to another service. Essentially transferring from A to C, via my server B.
Under the hood, Google's StorageObject -> downloadAsStream() uses Guzzle to get the file via fopen('php://temp','r+').
I am running into a disk space issue because Google's Cloud Storage library is not cleaning up the temp files if there is an exception thrown during the transfer. (This is expected behaviour per the docs). Every retry of the script dumps another huge file in my tmp dir which isn't cleaned up.
If Guzzle used tmpfile() I would be able to use stream_get_meta_data()['uri'] to get the file path, but because it uses php://temp, this option seems to be blocked off:
[
"wrapper_type" => "PHP",
"stream_type" => "TEMP",
"mode" => "w+b",
"unread_bytes" => 0,
"seekable" => true,
"uri" => "php://temp", // <<<<<<<< grr.
]
So: does anyone know of a way to get the temporary file name created by fopen('php://temp') such that I can perform a manual clean-up?
UPDATE:
It appears this isn't possible. Hopefully GCS will update their library to change the way the temp file is generated. Until then I am using the following clean-up code:
public function cleanTempDir(int $timeout = 7200) {
foreach (glob(sys_get_temp_dir()."/php*") as $f) {
if (is_writable($f) && filemtime($f) < (time() - $timeout))
unlink($f);
}
}
UPDATE 2
It is possible, see accepted answer below.

Answer 1

Something like the following should do the trick:
use Google\Cloud\Storage\StorageClient;
$client = new StorageClient;
$tempStream = tmpfile();
$tempFile = stream_get_meta_data($tempStream)['uri'];
try {
$stream = $client->bucket('my-bucket')
->object('my-big-ol-file')
->downloadAsStream([
'restOptions' => [
'sink' => $tempStream
]
]);
} catch (\Exception $ex) {
unlink($tempFile);
}
The restOptions option allows you to proxy through commands to the underlying HTTP 1.1 transport (Guzzle, by default). My apologies this isn't clearly documented, but hope it helps!

Answer 2

Google Cloud Platform Support here!
At the moment, using the php Cloud Storage library it is not possible to get the temporary file name created when using the method downloadAsStream(). Therefore I have created a Feature Request on your behalf, you can follow it here.
As a workaround, you may be able to remove the file by hand, you can get the temp file name using the following command:
$filename = shell_exec('ls -lt | awk 'NR==2' | cut -d: -f2 | cut -d " " -f2');
After that, $filename will contain the last modified file name, which will be the one that failed and you wish to remove. With the filename you can now proceed to remove it.
Notice that you will have to be in your php://temp folder before executing the function.

Answer 3

It will most likely be the system configured temporary directory which you can get by sys_get_temp_dir.
Note that this will only save to file if needed and can reside in memory.
https://www.php.net/manual/en/wrappers.php.php
Edit: Ok, the file created. Then you can probably use stream_get_meta_data on the stream handle to get that information from the stream.