1 files changed, 97 insertions, 0 deletions
diff --git a/lib/private/Lock/AbstractLockingProvider.php b/lib/private/Lock/AbstractLockingProvider.php
new file mode 100644
index 00000000000..d7e5976079c
--- /dev/null
+++ b/lib/private/Lock/AbstractLockingProvider.php
@@ -0,0 +1,97 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Lock;
+
+use OCP\Lock\ILockingProvider;
+
+/**
+ * Base locking provider that keeps track of locks acquired during the current request
+ * to release any leftover locks at the end of the request
+ */
+abstract class AbstractLockingProvider implements ILockingProvider {
+	protected array $acquiredLocks = [
+		'shared' => [],
+		'exclusive' => []
+	];
+
+	/**
+	 *
+	 * @param int $ttl how long until we clear stray locks in seconds
+	 */
+	public function __construct(
+		protected int $ttl,
+	) {
+	}
+
+	/** @inheritDoc */
+	protected function hasAcquiredLock(string $path, int $type): bool {
+		if ($type === self::LOCK_SHARED) {
+			return isset($this->acquiredLocks['shared'][$path]) && $this->acquiredLocks['shared'][$path] > 0;
+		} else {
+			return isset($this->acquiredLocks['exclusive'][$path]) && $this->acquiredLocks['exclusive'][$path] === true;
+		}
+	}
+
+	/** @inheritDoc */
+	protected function markAcquire(string $path, int $targetType): void {
+		if ($targetType === self::LOCK_SHARED) {
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} else {
+			$this->acquiredLocks['exclusive'][$path] = true;
+		}
+	}
+
+	/** @inheritDoc */
+	protected function markRelease(string $path, int $type): void {
+		if ($type === self::LOCK_SHARED) {
+			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
+				$this->acquiredLocks['shared'][$path]--;
+				if ($this->acquiredLocks['shared'][$path] === 0) {
+					unset($this->acquiredLocks['shared'][$path]);
+				}
+			}
+		} elseif ($type === self::LOCK_EXCLUSIVE) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+		}
+	}
+
+	/** @inheritDoc */
+	protected function markChange(string $path, int $targetType): void {
+		if ($targetType === self::LOCK_SHARED) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} elseif ($targetType === self::LOCK_EXCLUSIVE) {
+			$this->acquiredLocks['exclusive'][$path] = true;
+			$this->acquiredLocks['shared'][$path]--;
+		}
+	}
+
+	/** @inheritDoc */
+	public function releaseAll(): void {
+		foreach ($this->acquiredLocks['shared'] as $path => $count) {
+			for ($i = 0; $i < $count; $i++) {
+				$this->releaseLock($path, self::LOCK_SHARED);
+			}
+		}
+
+		foreach ($this->acquiredLocks['exclusive'] as $path => $hasLock) {
+			$this->releaseLock($path, self::LOCK_EXCLUSIVE);
+		}
+	}
+
+	protected function getOwnSharedLockCount(string $path): int {
+		return $this->acquiredLocks['shared'][$path] ?? 0;
+	}
+}