cap the number of entries we cache in smb's statcache

apps/files_external/lib/smb.php

@@ -35,6 +35,7 @@ use Icewind\SMB\NativeServer;
 use Icewind\SMB\Server;
 use Icewind\Streams\CallbackWrapper;
 use Icewind\Streams\IteratorDirectory;
+use OC\Cache\CappedMemoryCache;
 use OC\Files\Filesystem;
 
 class SMB extends Common {
@@ -48,10 +49,15 @@ class SMB extends Common {
 	 */
 	protected $share;
 
+	/**
+	 * @var string
+	 */
+	protected $root;
+
 	/**
 	 * @var \Icewind\SMB\FileInfo[]
 	 */
-	protected $statCache = array();
+	protected $statCache;
 
 	public function __construct($params) {
 		if (isset($params['host']) && isset($params['user']) && isset($params['password']) && isset($params['share'])) {
@@ -72,6 +78,7 @@ class SMB extends Common {
 		} else {
 			throw new \Exception('Invalid configuration');
 		}
+		$this->statCache = new CappedMemoryCache();
 	}
 
 	/**

lib/private/cache/cappedmemorycache.php

@@ -0,0 +1,87 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, 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\Cache;
+
+use OCP\ICache;
+
+/**
+ * In-memory cache with a capacity limit to keep memory usage in check
+ *
+ * Uses a simple FIFO expiry mechanism
+ */
+class CappedMemoryCache implements ICache, \ArrayAccess {
+
+	private $capacity;
+	private $cache = [];
+
+	public function __construct($capacity = 512) {
+		$this->capacity = $capacity;
+	}
+
+	public function hasKey($key) {
+		return isset($this->cache[$key]);
+	}
+
+	public function get($key) {
+		return isset($this->cache[$key]) ? $this->cache[$key] : null;
+	}
+
+	public function set($key, $value, $ttl = 0) {
+		$this->cache[$key] = $value;
+		$this->garbageCollect();
+	}
+
+	public function remove($key) {
+		unset($this->cache[$key]);
+		return true;
+	}
+
+	public function clear($prefix = '') {
+		$this->cache = [];
+		return true;
+	}
+
+	public function offsetExists($offset) {
+		return $this->hasKey($offset);
+	}
+
+	public function offsetGet($offset) {
+		return $this->get($offset);
+	}
+
+	public function offsetSet($offset, $value) {
+		$this->set($offset, $value);
+	}
+
+	public function offsetUnset($offset) {
+		$this->remove($offset);
+	}
+
+
+	private function garbageCollect() {
+		while (count($this->cache) > $this->capacity) {
+			reset($this->cache);
+			$key = key($this->cache);
+			$this->remove($key);
+		}
+	}
+}

tests/lib/cache.php

@@ -8,7 +8,7 @@
 
 abstract class Test_Cache extends \Test\TestCase {
 	/**
-	 * @var \OC\Cache cache;
+	 * @var \OCP\ICache cache;
 	 */
 	protected $instance;
 

tests/lib/cache/cappedmemorycache.php

@@ -0,0 +1,67 @@
+<?php
+/**
+ * ownCloud
+ *
+ * @author Robin Appelman
+ * @copyright 2016 Robin Appelman icewind@owncloud.com
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library 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 along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Test\Cache;
+
+/**
+ * Class FileCache
+ *
+ * @group DB
+ *
+ * @package Test\Cache
+ */
+class CappedMemoryCache extends \Test_Cache {
+	public function setUp() {
+		parent::setUp();
+		$this->instance = new \OC\Cache\CappedMemoryCache();
+	}
+
+	public function testSetOverCap() {
+		$instance = new \OC\Cache\CappedMemoryCache(3);
+
+		$instance->set('1', 'a');
+		$instance->set('2', 'b');
+		$instance->set('3', 'c');
+		$instance->set('4', 'd');
+		$instance->set('5', 'e');
+
+		$this->assertFalse($instance->hasKey('1'));
+		$this->assertFalse($instance->hasKey('2'));
+		$this->assertTrue($instance->hasKey('3'));
+		$this->assertTrue($instance->hasKey('4'));
+		$this->assertTrue($instance->hasKey('5'));
+	}
+
+	function testClear() {
+		$value = 'ipsum lorum';
+		$this->instance->set('1_value1', $value);
+		$this->instance->set('1_value2', $value);
+		$this->instance->set('2_value1', $value);
+		$this->instance->set('3_value1', $value);
+
+		$this->assertTrue($this->instance->clear());
+		$this->assertFalse($this->instance->hasKey('1_value1'));
+		$this->assertFalse($this->instance->hasKey('1_value2'));
+		$this->assertFalse($this->instance->hasKey('2_value1'));
+		$this->assertFalse($this->instance->hasKey('3_value1'));
+	}
+}