feat: add an option to filter what paths get checked for updates

lib/private/Files/Cache/Watcher.php

@@ -7,8 +7,11 @@
  */
 namespace OC\Files\Cache;
 
+use OCP\Files\Cache\ICache;
 use OCP\Files\Cache\ICacheEntry;
+use OCP\Files\Cache\IScanner;
 use OCP\Files\Cache\IWatcher;
+use OCP\Files\Storage\IStorage;
 
 /**
  * check the storage backends for updates and change the cache accordingly
@@ -19,27 +22,26 @@ class Watcher implements IWatcher {
 	protected $checkedPaths = [];
 
 	/**
-	 * @var \OC\Files\Storage\Storage $storage
+	 * @var IStorage $storage
 	 */
 	protected $storage;
 
 	/**
-	 * @var Cache $cache
+	 * @var ICache $cache
 	 */
 	protected $cache;
 
 	/**
-	 * @var Scanner $scanner ;
+	 * @var IScanner $scanner ;
 	 */
 	protected $scanner;
 
 	/** @var callable[] */
 	protected $onUpdate = [];
 
-	/**
-	 * @param \OC\Files\Storage\Storage $storage
-	 */
-	public function __construct(\OC\Files\Storage\Storage $storage) {
+	protected ?string $checkFilter = null;
+
+	public function __construct(IStorage $storage) {
 		$this->storage = $storage;
 		$this->cache = $storage->getCache();
 		$this->scanner = $storage->getScanner();
@@ -52,6 +54,10 @@ public function setPolicy($policy) {
 		$this->watchPolicy = $policy;
 	}
 
+	public function setCheckFilter(?string $filter): void {
+		$this->checkFilter = $filter;
+	}
+
 	/**
 	 * @return int either \OC\Files\Cache\Watcher::CHECK_NEVER, \OC\Files\Cache\Watcher::CHECK_ONCE, \OC\Files\Cache\Watcher::CHECK_ALWAYS
 	 */
@@ -116,6 +122,12 @@ public function update($path, $cachedData) {
 	 * @return bool
 	 */
 	public function needsUpdate($path, $cachedData) {
+		if ($this->checkFilter !== null) {
+			if (!preg_match($this->checkFilter, $path)) {
+				return false;
+			}
+		}
+
 		if ($this->watchPolicy === self::CHECK_ALWAYS || ($this->watchPolicy === self::CHECK_ONCE && !in_array($path, $this->checkedPaths))) {
 			$this->checkedPaths[] = $path;
 			return $cachedData['storage_mtime'] === null || $this->storage->hasUpdated($path, $cachedData['storage_mtime']);

lib/private/Files/Storage/Common.php

@@ -331,6 +331,7 @@ public function getWatcher(string $path = '', ?IStorage $storage = null): IWatch
 			$this->watcher = new Watcher($storage);
 			$globalPolicy = Server::get(IConfig::class)->getSystemValueInt('filesystem_check_changes', Watcher::CHECK_NEVER);
 			$this->watcher->setPolicy((int)$this->getMountOption('filesystem_check_changes', $globalPolicy));
+			$this->watcher->setCheckFilter($this->getMountOption('filesystem_check_filter'));
 		}
 		return $this->watcher;
 	}

lib/public/Files/Cache/IWatcher.php

@@ -34,6 +34,17 @@ interface IWatcher {
 	 */
 	public function setPolicy($policy);
 
+	/**
+	 * Set a filter regex, only paths matching the regex will be checked for updates.
+	 *
+	 * When set to `null`, every path will be checked for updates
+	 *
+	 * @param ?string $filter
+	 * @return void
+	 * @since 33.0.0
+	 */
+	public function setCheckFilter(?string $filter): void;
+
 	/**
 	 * @return int either IWatcher::CHECK_NEVER, IWatcher::CHECK_ONCE, IWatcher::CHECK_ALWAYS
 	 * @since 9.0.0

tests/lib/Files/Cache/WatcherTest.php

@@ -8,9 +8,13 @@
 
 namespace Test\Files\Cache;
 
+use OC\Files\Cache\CacheEntry;
 use OC\Files\Cache\Watcher;
 use OC\Files\Storage\Storage;
 use OC\Files\Storage\Temporary;
+use OCP\Files\Cache\IWatcher;
+use OCP\Files\Storage\IStorage;
+use PHPUnit\Framework\Attributes\DataProvider;
 
 /**
  * Class WatcherTest
@@ -192,4 +196,43 @@ private function getTestStorage($scan = true) {
 		$this->storages[] = $storage;
 		return $storage;
 	}
+
+	public static function checkFilterProvider(): array {
+		return [
+			[null, [
+				'' => true,
+				'foo' => true,
+				'foo.txt' => true,
+			]],
+			['/^.+$/', [
+				'' => false,
+				'foo' => true,
+				'foo.txt' => true,
+			]],
+			['/^.+\..+$/', [
+				'' => false,
+				'foo' => false,
+				'foo.txt' => true,
+			]]
+		];
+	}
+
+	#[DataProvider('checkFilterProvider')]
+	public function testCheckFilter($filter, $paths) {
+		$storage = $this->createMock(IStorage::class);
+		$storage->method('hasUpdated')
+			->willReturn(true);
+		$watcher = new Watcher($storage);
+		$watcher->setPolicy(IWatcher::CHECK_ALWAYS);
+
+		$watcher->setCheckFilter($filter);
+
+		$entry = new CacheEntry([
+			'storage_mtime' => 0,
+		]);
+
+		foreach ($paths as $patch => $shouldUpdate) {
+			$this->assertEquals($shouldUpdate, $watcher->needsUpdate($patch, $entry));
+		}
+	}
 }