From a785ac2ecf21f259ced5533cfd0841d492a123a2 Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Mon, 29 Jan 2018 16:14:10 +0100
Subject: [PATCH] Helper methods for permission retrieval inside workers

Their internals are rather hacky, but come with a only a minor impact on
the worker performance.

See #2524
---
 .../AbstractRebuildDataWorker.class.php       | 70 +++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/wcfsetup/install/files/lib/system/worker/AbstractRebuildDataWorker.class.php b/wcfsetup/install/files/lib/system/worker/AbstractRebuildDataWorker.class.php
index 45fcc746b8..d3b9d23ee4 100644
--- a/wcfsetup/install/files/lib/system/worker/AbstractRebuildDataWorker.class.php
+++ b/wcfsetup/install/files/lib/system/worker/AbstractRebuildDataWorker.class.php
@@ -1,6 +1,9 @@
 <?php
 namespace wcf\system\worker;
 use wcf\data\DatabaseObjectList;
+use wcf\data\user\group\UserGroup;
+use wcf\system\cache\builder\UserGroupPermissionCacheBuilder;
+use wcf\system\database\util\PreparedStatementConditionBuilder;
 use wcf\system\event\EventHandler;
 use wcf\system\exception\ParentClassException;
 use wcf\system\exception\SystemException;
@@ -100,6 +103,73 @@ abstract class AbstractRebuildDataWorker extends AbstractWorker implements IRebu
 		$this->objectList->sqlOffset = $this->limit * $this->loopCount;
 	}
 	
+	/**
+	 * Returns the value of the permissions for the provided user ids. The special index `0` is
+	 * automatically added and represents a guest user.
+	 * 
+	 * @param       integer[]       $userIDs
+	 * @param       string[]        $permissions
+	 * @return      mixed[]         permission value per user id
+	 */
+	protected function getBulkUserPermissions(array $userIDs, array $permissions) {
+		$conditions = new PreparedStatementConditionBuilder();
+		$conditions->add("userID IN (?)", [$userIDs]);
+		
+		$sql = "SELECT	userID, groupID
+			FROM	wcf".WCF_N."_user_to_group
+			".$conditions;
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute($conditions->getParameters());
+		
+		$groupData = [];
+		while ($row = $statement->fetchArray()) {
+			$userID = $row['userID'];
+			if (!isset($groupData[$userID])) $groupData[$userID] = [];
+			
+			$groupData[$userID][] = $row['groupID'];
+		}
+		
+		$userPermissions = [];
+		foreach ($groupData as $userID => $groupIDs) {
+			$data = UserGroupPermissionCacheBuilder::getInstance()->getData($groupIDs);
+			
+			$userPermissions[$userID] = [];
+			foreach ($permissions as $permission) {
+				$userPermissions[$userID][$permission] = (isset($data[$permission])) ? $data[$permission] : false;
+			}
+		}
+		
+		// add guest user
+		$data = UserGroupPermissionCacheBuilder::getInstance()->getData(UserGroup::getGroupIDsByType([UserGroup::GUESTS, UserGroup::EVERYONE]));
+		$userPermissions[0] = [];
+		foreach ($permissions as $permission) {
+			$userPermissions[0][$permission] = (isset($data[$permission])) ? $data[$permission] : false;
+		}
+		
+		return $userPermissions;
+	}
+	
+	/**
+	 * Returns the permission value for the provided user id, will be treated as guest
+	 * if the user id cannot be found or is invalid. This method is designed to be used
+	 * with the return value of `getBulkUserPermissions()`.
+	 * 
+	 * @param       mixed[]         $userPermissions
+	 * @param       integer         $userID
+	 * @param       string          $permission
+	 * @return      mixed
+	 */
+	protected function getBulkUserPermissionValue(array &$userPermissions, $userID, $permission) {
+		$userID = intval($userID);
+		
+		// resolve non-existing users against the guest permission
+		if ($userID && !isset($userPermissions[$userID])) {
+			return $this->getBulkUserPermissionValue($userPermissions, 0, $permission);
+		}
+		
+		return $userPermissions[$userID][$permission];
+	}
+	
 	/**
 	 * @inheritDoc
 	 */
-- 
2.20.1