From 71a0cdceaaad76cd08f48c28d3da40d7fc8d2abf Mon Sep 17 00:00:00 2001
From: Ari Selseng <ari@selseng.net>
Date: Sun, 3 Mar 2019 01:36:27 +0100
Subject: [PATCH] Reconnect to DB after timeout for Notify command. Fixes
 #14479

Signed-off-by: Ari Selseng <ari@selseng.net>
---
 apps/files_external/lib/Command/Notify.php | 58 ++++++++++++++++++----
 1 file changed, 48 insertions(+), 10 deletions(-)

diff --git a/apps/files_external/lib/Command/Notify.php b/apps/files_external/lib/Command/Notify.php
index b859a825c8..a0b116f07d 100644
--- a/apps/files_external/lib/Command/Notify.php
+++ b/apps/files_external/lib/Command/Notify.php
@@ -2,6 +2,7 @@
 /**
  * @copyright Copyright (c) 2016 Robin Appelman <robin@icewind.nl>
  *
+ * @author Ari Selseng <ari@selseng.net>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Roeland Jago Douma <roeland@famdouma.nl>
  *
@@ -24,6 +25,7 @@
 
 namespace OCA\Files_External\Command;
 
+use Doctrine\DBAL\Exception\DriverException;
 use OC\Core\Command\Base;
 use OCA\Files_External\Lib\InsufficientDataForMeaningfulAnswerException;
 use OCA\Files_External\Lib\StorageConfig;
@@ -52,12 +54,7 @@ class Notify extends Base {
 		parent::__construct();
 		$this->globalService = $globalService;
 		$this->connection = $connection;
-		// the query builder doesn't really like subqueries with parameters
-		$this->updateQuery = $this->connection->prepare(
-			'UPDATE *PREFIX*filecache SET size = -1
-			WHERE `path` = ?
-			AND `storage` IN (SELECT storage_id FROM *PREFIX*mounts WHERE mount_id = ?)'
-		);
+		$this->updateQuery = $this->getUpdateQuery($this->connection);
 	}
 
 	protected function configure() {
@@ -143,9 +140,9 @@ class Notify extends Base {
 				$this->logUpdate($change, $output);
 			}
 			if ($change instanceof IRenameChange) {
-				$this->markParentAsOutdated($mount->getId(), $change->getTargetPath());
+				$this->markParentAsOutdated($mount->getId(), $change->getTargetPath(), $output);
 			}
-			$this->markParentAsOutdated($mount->getId(), $change->getPath());
+			$this->markParentAsOutdated($mount->getId(), $change->getPath(), $output);
 		});
 	}
 
@@ -154,12 +151,20 @@ class Notify extends Base {
 		return new $class($mount->getBackendOptions());
 	}
 
-	private function markParentAsOutdated($mountId, $path) {
+	private function markParentAsOutdated($mountId, $path, OutputInterface $output) {
 		$parent = ltrim(dirname($path), '/');
 		if ($parent === '.') {
 			$parent = '';
 		}
-		$this->updateQuery->execute([$parent, $mountId]);
+
+		try {
+			$this->updateQuery->execute([$parent, $mountId]);
+		} catch (DriverException $th) {
+			$this->connection = $this->reconnectToDatabase($this->connection, $output);
+			$output->writeln('<info>Needed to reconnect to the database</info>');
+			$this->updateQuery = $this->getUpdateQuery($this->connection);
+			$this->updateQuery->execute([$parent, $mountId]);
+		}
 	}
 
 	private function logUpdate(IChange $change, OutputInterface $output) {
@@ -188,6 +193,39 @@ class Notify extends Base {
 		$output->writeln($text);
 	}
 
+	/**
+	 * @return \Doctrine\DBAL\Statement
+	*/
+	private function getUpdateQuery(IDBConnection $connection) {
+		// the query builder doesn't really like subqueries with parameters
+		return $connection->prepare(
+			'UPDATE *PREFIX*filecache SET size = -1
+			WHERE `path` = ?
+			AND `storage` IN (SELECT storage_id FROM *PREFIX*mounts WHERE mount_id = ?)'
+		);
+	}
+
+	/**
+	 * @return \OCP\IDBConnection
+	*/
+	private function reconnectToDatabase(IDBConnection $connection, OutputInterface $output) {
+		try {
+			$connection->close();
+		} catch (\Exception $ex) {
+			$output->writeln("<info>Error while disconnecting from database: {$ex->getMessage()}</info>");
+		}
+		while (!$connection->isConnected()) {
+			try {
+				$connection->connect();
+			} catch (\Exception $ex) {
+				$output->writeln("<info>Error while re-connecting to database: {$ex->getMessage()}</info>");
+				sleep(60);
+			}
+		}
+		return $connection;
+	}
+
+
 	private function selfTest(IStorage $storage, INotifyHandler $notifyHandler, $verbose, OutputInterface $output) {
 		usleep(100 * 1000); //give time for the notify to start
 		$storage->file_put_contents('/.nc_test_file.txt', 'test content');