1 files changed, 185 insertions, 0 deletions
diff --git a/apps/files_versions/lib/expiration.php b/apps/files_versions/lib/expiration.php
new file mode 100644
index 00000000000..d42c62f0ee3
--- /dev/null
+++ b/apps/files_versions/lib/expiration.php
@@ -0,0 +1,185 @@
+<?php
+/**
+ * @author Victor Dubiniuk <dubiniuk@owncloud.com>
+ *
+ * @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 OCA\Files_Versions;
+
+use \OCP\IConfig;
+use \OCP\AppFramework\Utility\ITimeFactory;
+
+class Expiration {
+
+	// how long do we keep files a version if no other value is defined in the config file (unit: days)
+	const NO_OBLIGATION = -1;
+
+	/** @var ITimeFactory */
+	private $timeFactory;
+
+	/** @var string */
+	private $retentionObligation;
+
+	/** @var int */
+	private $minAge;
+
+	/** @var int */
+	private $maxAge;
+
+	/** @var bool */
+	private $canPurgeToSaveSpace;
+
+	public function __construct(IConfig $config,ITimeFactory $timeFactory){
+		$this->timeFactory = $timeFactory;
+		$this->retentionObligation = $config->getSystemValue('versions_retention_obligation', 'auto');
+
+		if ($this->retentionObligation !== 'disabled') {
+			$this->parseRetentionObligation();
+		}
+	}
+
+	/**
+	 * Is versions expiration enabled
+	 * @return bool
+	 */
+	public function isEnabled(){
+		return $this->retentionObligation !== 'disabled';
+	}
+
+	/**
+	 * Is default expiration active
+	 */
+	public function shouldAutoExpire(){
+		return $this->minAge === self::NO_OBLIGATION
+				|| $this->maxAge === self::NO_OBLIGATION;
+	}
+
+	/**
+	 * Check if given timestamp in expiration range
+	 * @param int $timestamp
+	 * @param bool $quotaExceeded
+	 * @return bool
+	 */
+	public function isExpired($timestamp, $quotaExceeded = false){
+		// No expiration if disabled
+		if (!$this->isEnabled()) {
+			return false;
+		}
+
+		// Purge to save space (if allowed)
+		if ($quotaExceeded && $this->canPurgeToSaveSpace) {
+			return true;
+		}
+
+		$time = $this->timeFactory->getTime();
+		// Never expire dates in future e.g. misconfiguration or negative time
+		// adjustment
+		if ($time<$timestamp) {
+			return false;
+		}
+
+		// Purge as too old
+		if ($this->maxAge !== self::NO_OBLIGATION) {
+			$maxTimestamp = $time - ($this->maxAge * 86400);
+			$isOlderThanMax = $timestamp < $maxTimestamp;
+		} else {
+			$isOlderThanMax = false;
+		}
+
+		if ($this->minAge !== self::NO_OBLIGATION) {
+			// older than Min obligation and we are running out of quota?
+			$minTimestamp = $time - ($this->minAge * 86400);
+			$isMinReached = ($timestamp < $minTimestamp) && $quotaExceeded;
+		} else {
+			$isMinReached = false;
+		}
+
+		return $isOlderThanMax || $isMinReached;
+	}
+
+	/**
+	* Read versions_retention_obligation, validate it 
+	* and set private members accordingly
+	*/
+	private function parseRetentionObligation(){
+		$splitValues = explode(',', $this->retentionObligation);
+		if (!isset($splitValues[0])) {
+			$minValue = 'auto';
+		} else {
+			$minValue = trim($splitValues[0]);
+		}
+
+		if (!isset($splitValues[1])) {
+			$maxValue = self::NO_OBLIGATION;
+		} else {
+			$maxValue = trim($splitValues[1]);
+		}
+
+		$isValid = true;
+		// Validate
+		if (!ctype_digit($minValue) && $minValue !== 'auto') {
+			$isValid = false;
+			\OC::$server->getLogger()->warning(
+					$minValue . ' is not a valid value for minimal versions retention obligation. Check versions_retention_obligation in your config.php. Falling back to auto.',
+					['app'=>'files_versions']
+			);
+		}
+
+		if (!ctype_digit($maxValue) && $maxValue !== 'auto') {
+			$isValid = false;
+			\OC::$server->getLogger()->warning(
+					$maxValue . ' is not a valid value for maximal versions retention obligation. Check versions_retention_obligation in your config.php. Falling back to auto.',
+					['app'=>'files_versions']
+			);
+		}
+
+		if (!$isValid){
+			$minValue = 'auto';
+			$maxValue = 'auto';
+		}
+
+
+		if ($minValue === 'auto' && $maxValue === 'auto') {
+			// Default: Delete anytime if space needed
+			$this->minAge = self::NO_OBLIGATION;
+			$this->maxAge = self::NO_OBLIGATION;
+			$this->canPurgeToSaveSpace = true;
+		} elseif ($minValue !== 'auto' && $maxValue === 'auto') {
+			// Keep for X days but delete anytime if space needed
+			$this->minAge = intval($minValue);
+			$this->maxAge = self::NO_OBLIGATION;
+			$this->canPurgeToSaveSpace = true;
+		} elseif ($minValue === 'auto' && $maxValue !== 'auto') {
+			// Delete anytime if space needed, Delete all older than max automatically
+			$this->minAge = self::NO_OBLIGATION;
+			$this->maxAge = intval($maxValue);
+			$this->canPurgeToSaveSpace = true;
+		} elseif ($minValue !== 'auto' && $maxValue !== 'auto') {
+			// Delete all older than max OR older than min if space needed
+
+			// Max < Min as per https://github.com/owncloud/core/issues/16301
+			if ($maxValue < $minValue) {
+				$maxValue = $minValue;
+			}
+
+			$this->minAge = intval($minValue);
+			$this->maxAge = intval($maxValue);
+			$this->canPurgeToSaveSpace = false;
+		}
+	}
+}