Store storage availability in database

Storage status is saved in the database. Failed storages are rechecked every
10 minutes, while working storages are rechecked every request.

Using the files_external app will recheck all external storages when the
settings page is viewed, or whenever an external storage is saved.

6 files changed, 565 insertions, 10 deletions

diff --git a/lib/private/files/cache/storage.php b/lib/private/files/cache/storage.php
index ebef245f399..338d8308281 100644
--- a/lib/private/files/cache/storage.php
+++ b/lib/private/files/cache/storage.php
@@ -43,9 +43,10 @@ class Storage {
 
 	/**
 	 * @param \OC\Files\Storage\Storage|string $storage
+	 * @param bool $isAvailable
 	 * @throws \RuntimeException
 	 */
-	public function __construct($storage) {
+	public function __construct($storage, $isAvailable = true) {
 		if ($storage instanceof \OC\Files\Storage\Storage) {
 			$this->storageId = $storage->getId();
 		} else {
@@ -53,17 +54,14 @@ class Storage {
 		}
 		$this->storageId = self::adjustStorageId($this->storageId);
 
-		$sql = 'SELECT `numeric_id` FROM `*PREFIX*storages` WHERE `id` = ?';
-		$result = \OC_DB::executeAudited($sql, array($this->storageId));
-		if ($row = $result->fetchRow()) {
+		if ($row = self::getStorageById($this->storageId)) {
 			$this->numericId = $row['numeric_id'];
 		} else {
 			$connection = \OC_DB::getConnection();
-			if ($connection->insertIfNotExist('*PREFIX*storages', ['id' => $this->storageId])) {
+			if ($connection->insertIfNotExist('*PREFIX*storages', ['id' => $this->storageId, 'available' => $isAvailable])) {
 				$this->numericId = \OC_DB::insertid('*PREFIX*storages');
 			} else {
-				$result = \OC_DB::executeAudited($sql, array($this->storageId));
-				if ($row = $result->fetchRow()) {
+				if ($row = self::getStorageById($this->storageId)) {
 					$this->numericId = $row['numeric_id'];
 				} else {
 					throw new \RuntimeException('Storage could neither be inserted nor be selected from the database');
@@ -73,6 +71,16 @@ class Storage {
 	}
 
 	/**
+	 * @param string $storageId
+	 * @return array|null
+	 */
+	public static function getStorageById($storageId) {
+		$sql = 'SELECT * FROM `*PREFIX*storages` WHERE `id` = ?';
+		$result = \OC_DB::executeAudited($sql, array($storageId));
+		return $result->fetchRow();
+	}
+
+	/**
 	 * Adjusts the storage id to use md5 if too long
 	 * @param string $storageId storage id
 	 * @return string unchanged $storageId if its length is less than 64 characters,
@@ -120,9 +128,7 @@ class Storage {
 	public static function getNumericStorageId($storageId) {
 		$storageId = self::adjustStorageId($storageId);
 
-		$sql = 'SELECT `numeric_id` FROM `*PREFIX*storages` WHERE `id` = ?';
-		$result = \OC_DB::executeAudited($sql, array($storageId));
-		if ($row = $result->fetchRow()) {
+		if ($row = self::getStorageById($storageId)) {
 			return $row['numeric_id'];
 		} else {
 			return null;
@@ -130,6 +136,28 @@ class Storage {
 	}
 
 	/**
+	 * @return array|null [ available, last_checked ]
+	 */
+	public function getAvailability() {
+		if ($row = self::getStorageById($this->storageId)) {
+			return [
+				'available' => $row['available'],
+				'last_checked' => $row['last_checked']
+			];
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * @param bool $isAvailable
+	 */
+	public function setAvailability($isAvailable) {
+		$sql = 'UPDATE `*PREFIX*storages` SET `available` = ?, `last_checked` = ? WHERE `id` = ?';
+		\OC_DB::executeAudited($sql, array($isAvailable, time(), $this->storageId));
+	}
+
+	/**
 	 * Check if a string storage id is known
 	 *
 	 * @param string $storageId
diff --git a/lib/private/files/storage/common.php b/lib/private/files/storage/common.php
index 847cb8492fe..d006f1fb486 100644
--- a/lib/private/files/storage/common.php
+++ b/lib/private/files/storage/common.php
@@ -404,6 +404,11 @@ abstract class Common implements Storage {
 		return implode('/', $output);
 	}
 
+	/**
+	 * Test a storage for availability
+	 *
+	 * @return bool
+	 */
 	public function test() {
 		if ($this->stat('')) {
 			return true;
@@ -650,4 +655,18 @@ abstract class Common implements Storage {
 	public function changeLock($path, $type, ILockingProvider $provider) {
 		$provider->changeLock('files/' . md5($this->getId() . '::' . trim($path, '/')), $type);
 	}
+
+	/**
+	 * @return array [ available, last_checked ]
+	 */
+	public function getAvailability() {
+		return $this->getStorageCache()->getAvailability();
+	}
+
+	/**
+	 * @param bool $isAvailable
+	 */
+	public function setAvailability($isAvailable) {
+		$this->getStorageCache()->setAvailability($isAvailable);
+	}
 }
diff --git a/lib/private/files/storage/wrapper/availability.php b/lib/private/files/storage/wrapper/availability.php
new file mode 100644
index 00000000000..37319a8f7d1
--- /dev/null
+++ b/lib/private/files/storage/wrapper/availability.php
@@ -0,0 +1,462 @@
+<?php
+/**
+ * @author Robin McCorkell <rmccorkell@karoshi.org.uk>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\Files\Storage\Wrapper;
+
+/**
+ * Availability checker for storages
+ *
+ * Throws a StorageNotAvailableException for storages with known failures
+ */
+class Availability extends Wrapper {
+	const RECHECK_TTL_SEC = 600; // 10 minutes
+
+	/**
+	 * @return bool
+	 */
+	private function updateAvailability() {
+		try {
+			$result = $this->test();
+		} catch (\Exception $e) {
+			$result = false;
+		}
+		$this->setAvailability($result);
+		return $result;
+	}
+
+	/**
+	 * @return bool
+	 */
+	private function isAvailable() {
+		$availability = $this->getAvailability();
+		if (!$availability['available']) {
+			// trigger a recheck if TTL reached
+			if ((time() - $availability['last_checked']) > self::RECHECK_TTL_SEC) {
+				return $this->updateAvailability();
+			}
+		}
+		return $availability['available'];
+	}
+
+	/**
+	 * @throws \OCP\Files\StorageNotAvailableException
+	 */
+	private function checkAvailability() {
+		if (!$this->isAvailable()) {
+			throw new \OCP\Files\StorageNotAvailableException();
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function mkdir($path) {
+		$this->checkAvailability();
+		try {
+			return parent::mkdir($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function rmdir($path) {
+		$this->checkAvailability();
+		try {
+			return parent::rmdir($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function opendir($path) {
+		$this->checkAvailability();
+		try {
+			return parent::opendir($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function is_dir($path) {
+		$this->checkAvailability();
+		try {
+			return parent::is_dir($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function is_file($path) {
+		$this->checkAvailability();
+		try {
+			return parent::is_file($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function stat($path) {
+		$this->checkAvailability();
+		try {
+			return parent::stat($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function filetype($path) {
+		$this->checkAvailability();
+		try {
+			return parent::filetype($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function filesize($path) {
+		$this->checkAvailability();
+		try {
+			return parent::filesize($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function isCreatable($path) {
+		$this->checkAvailability();
+		try {
+			return parent::isCreatable($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function isReadable($path) {
+		$this->checkAvailability();
+		try {
+			return parent::isReadable($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function isUpdatable($path) {
+		$this->checkAvailability();
+		try {
+			return parent::isUpdatable($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function isDeletable($path) {
+		$this->checkAvailability();
+		try {
+			return parent::isDeletable($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function isSharable($path) {
+		$this->checkAvailability();
+		try {
+			return parent::isSharable($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getPermissions($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getPermissions($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function file_exists($path) {
+		$this->checkAvailability();
+		try {
+			return parent::file_exists($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function filemtime($path) {
+		$this->checkAvailability();
+		try {
+			return parent::filemtime($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function file_get_contents($path) {
+		$this->checkAvailability();
+		try {
+			return parent::file_get_contents($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function file_put_contents($path, $data) {
+		$this->checkAvailability();
+		try {
+			return parent::file_put_contents($path, $data);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function unlink($path) {
+		$this->checkAvailability();
+		try {
+			return parent::unlink($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function rename($path1, $path2) {
+		$this->checkAvailability();
+		try {
+			return parent::rename($path1, $path2);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function copy($path1, $path2) {
+		$this->checkAvailability();
+		try {
+			return parent::copy($path1, $path2);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function fopen($path, $mode) {
+		$this->checkAvailability();
+		try {
+			return parent::fopen($path, $mode);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getMimeType($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getMimeType($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function hash($type, $path, $raw = false) {
+		$this->checkAvailability();
+		try {
+			return parent::hash($type, $path, $raw);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function free_space($path) {
+		$this->checkAvailability();
+		try {
+			return parent::free_space($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function search($query) {
+		$this->checkAvailability();
+		try {
+			return parent::search($query);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function touch($path, $mtime = null) {
+		$this->checkAvailability();
+		try {
+			return parent::touch($path, $mtime);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getLocalFile($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getLocalFile($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getLocalFolder($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getLocalFolder($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function hasUpdated($path, $time) {
+		$this->checkAvailability();
+		try {
+			return parent::hasUpdated($path, $time);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getOwner($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getOwner($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getETag($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getETag($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getDirectDownload($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getDirectDownload($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function copyFromStorage(\OCP\Files\Storage $sourceStorage, $sourceInternalPath, $targetInternalPath) {
+		$this->checkAvailability();
+		try {
+			return parent::copyFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function moveFromStorage(\OCP\Files\Storage $sourceStorage, $sourceInternalPath, $targetInternalPath) {
+		$this->checkAvailability();
+		try {
+			return parent::moveFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+
+	/** {@inheritdoc} */
+	public function getMetaData($path) {
+		$this->checkAvailability();
+		try {
+			return parent::getMetaData($path);
+		} catch (\OCP\Files\StorageNotAvailableException $e) {
+			$this->setAvailability(false);
+			throw $e;
+		}
+	}
+}
diff --git a/lib/private/files/storage/wrapper/wrapper.php b/lib/private/files/storage/wrapper/wrapper.php
index d1414880beb..b43dd4fe142 100644
--- a/lib/private/files/storage/wrapper/wrapper.php
+++ b/lib/private/files/storage/wrapper/wrapper.php
@@ -498,6 +498,24 @@ class Wrapper implements \OC\Files\Storage\Storage {
 	}
 
 	/**
+	 * Get availability of the storage
+	 *
+	 * @return array [ available, last_checked ]
+	 */
+	public function getAvailability() {
+		return $this->storage->getAvailability();
+	}
+
+	/**
+	 * Set availability of the storage
+	 *
+	 * @param bool $isAvailable
+	 */
+	public function setAvailability($isAvailable) {
+		$this->storage->setAvailability($isAvailable);
+	}
+
+	/**
 	 * @param string $path the path of the target folder
 	 * @param string $fileName the name of the file itself
 	 * @return void
diff --git a/lib/private/util.php b/lib/private/util.php
index 39d64952dc6..8a85a8a5f0d 100644
--- a/lib/private/util.php
+++ b/lib/private/util.php
@@ -143,6 +143,14 @@ class OC_Util {
 			return $storage;
 		});
 
+		// install storage availability wrapper, before most other wrappers
+		\OC\Files\Filesystem::addStorageWrapper('oc_availability', function ($mountPoint, $storage) {
+			if (!$storage->isLocal()) {
+				return new \OC\Files\Storage\Wrapper\Availability(['storage' => $storage]);
+			}
+			return $storage;
+		});
+
 		\OC\Files\Filesystem::addStorageWrapper('oc_quota', function ($mountPoint, $storage) {
 			// set up quota for home storages, even for other users
 			// which can happen when using sharing
diff --git a/lib/public/files/storage.php b/lib/public/files/storage.php
index 41218996382..ac3603e48d4 100644
--- a/lib/public/files/storage.php
+++ b/lib/public/files/storage.php
@@ -439,4 +439,24 @@ interface Storage {
 	 * @since 8.1.0
 	 */
 	public function changeLock($path, $type, ILockingProvider $provider);
+
+	/**
+	 * Test a storage for availability
+	 *
+	 * @since 8.2.0
+	 * @return bool
+	 */
+	public function test();
+
+	/**
+	 * @since 8.2.0
+	 * @return array [ available, last_checked ]
+	 */
+	public function getAvailability();
+
+	/**
+	 * @since 8.2.0
+	 * @param bool $isAvailable
+	 */
+	public function setAvailability($isAvailable);
 }