controllers/Download.php

@@ -34,7 +34,7 @@ class Download
 		$files = [];
 
 		$album_ids = array_merge([$album->id_tag], $this->getChildAlbumIds($album->id_tag));
-		foreach($album_ids as $album_id)
+		foreach ($album_ids as $album_id)
 		{
 			$iterator = AssetIterator::getByOptions(['id_tag' => $album_id]);
 			while ($asset = $iterator->next())
@@ -42,8 +42,8 @@ class Download
 		}
 
 		$descriptorspec = [
-			0 => ['pipe', 'r'],
-			1 => ['pipe', 'w'],
+			0 => ['pipe', 'r'], // STDIN
+			1 => ['pipe', 'w'], // STDOUT
 		];
 
 		$command = 'tar -cf - -C ' . escapeshellarg(ASSETSDIR) . ' --null -T -';
@@ -59,22 +59,33 @@ class Download
 		if(!$pipes[1])
 			throw new UnexpectedValueException('Could not open pipe for STDOUT');
 
-		$album_name = $album->tag;
+		// STDOUT should not block.
+		stream_set_blocking($pipes[1], 0);
 
 		header('Pragma: no-cache');
 		header('Content-Description: File Download');
-		header('Content-disposition: attachment; filename="' . $album_name . '.tar"');
+		header('Content-disposition: attachment; filename="' . $album->tag . '.tar"');
 		header('Content-Type: application/octet-stream');
 		header('Content-Transfer-Encoding: binary');
 
-		foreach($files as $file)
+		// Write filenames to include to STDIN, separated by null bytes.
+		foreach ($files as $file)
 			fwrite($pipes[0], $file . "\0");
 
+		// Close STDIN pipe to start archiving.
 		fclose($pipes[0]);
 
-		while($chunk = stream_get_contents($pipes[1], 4096))
-			echo $chunk;
+		do
+		{
+			// Read STDOUT as `tar` is doing its work.
+			echo stream_get_contents($pipes[1], 4096);
 
+			// Are we still running?
+			$status = proc_get_status($proc);
+		}
+		while (!empty($status) && $status['running']);
+
+		// Close STDOUT pipe and clean up process.
 		fclose($pipes[1]);
 
 		proc_close($proc);