nextcloud / server

lib/private/Share/Helper.php

Indentation +232 added lines, -232 removed lines

@@ -36,263 +36,263 @@
 
 class Helper extends \OC\Share\Constants {
 
-	/**
-	 * Generate a unique target for the item
-	 * @param string $itemType
-	 * @param string $itemSource
-	 * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_LINK
-	 * @param string $shareWith User or group the item is being shared with
-	 * @param string $uidOwner User that is the owner of shared item
-	 * @param string $suggestedTarget The suggested target originating from a reshare (optional)
-	 * @param int $groupParent The id of the parent group share (optional)
-	 * @throws \Exception
-	 * @return string Item target
-	 */
-	public static function generateTarget($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $suggestedTarget = null, $groupParent = null) {
-		// FIXME: $uidOwner and $groupParent seems to be unused
-		$backend = \OC\Share\Share::getBackend($itemType);
-		if ($shareType === IShare::TYPE_LINK || $shareType === IShare::TYPE_REMOTE) {
-			if (isset($suggestedTarget)) {
-				return $suggestedTarget;
-			}
-			return $backend->generateTarget($itemSource, false);
-		} else {
-			if ($shareType == IShare::TYPE_USER) {
-				// Share with is a user, so set share type to user and groups
-				$shareType = self::$shareTypeUserAndGroups;
-			}
+    /**
+     * Generate a unique target for the item
+     * @param string $itemType
+     * @param string $itemSource
+     * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_LINK
+     * @param string $shareWith User or group the item is being shared with
+     * @param string $uidOwner User that is the owner of shared item
+     * @param string $suggestedTarget The suggested target originating from a reshare (optional)
+     * @param int $groupParent The id of the parent group share (optional)
+     * @throws \Exception
+     * @return string Item target
+     */
+    public static function generateTarget($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $suggestedTarget = null, $groupParent = null) {
+        // FIXME: $uidOwner and $groupParent seems to be unused
+        $backend = \OC\Share\Share::getBackend($itemType);
+        if ($shareType === IShare::TYPE_LINK || $shareType === IShare::TYPE_REMOTE) {
+            if (isset($suggestedTarget)) {
+                return $suggestedTarget;
+            }
+            return $backend->generateTarget($itemSource, false);
+        } else {
+            if ($shareType == IShare::TYPE_USER) {
+                // Share with is a user, so set share type to user and groups
+                $shareType = self::$shareTypeUserAndGroups;
+            }
 
-			// Check if suggested target exists first
-			if (!isset($suggestedTarget)) {
-				$suggestedTarget = $itemSource;
-			}
-			if ($shareType == IShare::TYPE_GROUP) {
-				$target = $backend->generateTarget($suggestedTarget, false);
-			} else {
-				$target = $backend->generateTarget($suggestedTarget, $shareWith);
-			}
+            // Check if suggested target exists first
+            if (!isset($suggestedTarget)) {
+                $suggestedTarget = $itemSource;
+            }
+            if ($shareType == IShare::TYPE_GROUP) {
+                $target = $backend->generateTarget($suggestedTarget, false);
+            } else {
+                $target = $backend->generateTarget($suggestedTarget, $shareWith);
+            }
 
-			return $target;
-		}
-	}
+            return $target;
+        }
+    }
 
-	/**
-	 * Delete all reshares and group share children of an item
-	 * @param int $parent Id of item to delete
-	 * @param bool $excludeParent If true, exclude the parent from the delete (optional)
-	 * @param string $uidOwner The user that the parent was shared with (optional)
-	 * @param int $newParent new parent for the childrens
-	 * @param bool $excludeGroupChildren exclude group children elements
-	 */
-	public static function delete($parent, $excludeParent = false, $uidOwner = null, $newParent = null, $excludeGroupChildren = false) {
-		$ids = [$parent];
-		$deletedItems = [];
-		$changeParent = [];
-		$parents = [$parent];
-		while (!empty($parents)) {
-			$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
-			$query->select(
-				'id', 'share_with', 'item_type', 'share_type',
-				'item_target', 'file_target', 'parent'
-				)
-				->from('share')
-				->where($query->expr()->in('parent', $query->createNamedParameter(
-					$parents, IQueryBuilder::PARAM_INT_ARRAY
-				)));
+    /**
+     * Delete all reshares and group share children of an item
+     * @param int $parent Id of item to delete
+     * @param bool $excludeParent If true, exclude the parent from the delete (optional)
+     * @param string $uidOwner The user that the parent was shared with (optional)
+     * @param int $newParent new parent for the childrens
+     * @param bool $excludeGroupChildren exclude group children elements
+     */
+    public static function delete($parent, $excludeParent = false, $uidOwner = null, $newParent = null, $excludeGroupChildren = false) {
+        $ids = [$parent];
+        $deletedItems = [];
+        $changeParent = [];
+        $parents = [$parent];
+        while (!empty($parents)) {
+            $query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+            $query->select(
+                'id', 'share_with', 'item_type', 'share_type',
+                'item_target', 'file_target', 'parent'
+                )
+                ->from('share')
+                ->where($query->expr()->in('parent', $query->createNamedParameter(
+                    $parents, IQueryBuilder::PARAM_INT_ARRAY
+                )));
 
-			if (count($ids) === 1 && isset($uidOwner)) {
-				// Check the owner on the first search of reshares, useful for
-				// finding and deleting the reshares by a single user of a group share
-				$query->andWhere($query->expr()->eq('uid_owner', $uidOwner));
-			}
+            if (count($ids) === 1 && isset($uidOwner)) {
+                // Check the owner on the first search of reshares, useful for
+                // finding and deleting the reshares by a single user of a group share
+                $query->andWhere($query->expr()->eq('uid_owner', $uidOwner));
+            }
 
-			if ($excludeGroupChildren) {
-				$query->andWhere($query->expr()->eq('share_type', self::$shareTypeGroupUserUnique));
-			}
+            if ($excludeGroupChildren) {
+                $query->andWhere($query->expr()->eq('share_type', self::$shareTypeGroupUserUnique));
+            }
 
-			$result = $query->execute();
-			// Reset parents array, only go through loop again if items are found
-			$parents = [];
-			while ($item = $result->fetch()) {
-				$tmpItem = [
-					'id' => $item['id'],
-					'shareWith' => $item['share_with'],
-					'itemTarget' => $item['item_target'],
-					'itemType' => $item['item_type'],
-					'shareType' => (int)$item['share_type'],
-				];
-				if (isset($item['file_target'])) {
-					$tmpItem['fileTarget'] = $item['file_target'];
-				}
-				// if we have a new parent for the child we remember the child
-				// to update the parent, if not we add it to the list of items
-				// which should be deleted
-				if ($newParent !== null) {
-					$changeParent[] = $item['id'];
-				} else {
-					$deletedItems[] = $tmpItem;
-					$ids[] = $item['id'];
-					$parents[] = $item['id'];
-				}
-			}
-			$result->closeCursor();
-		}
-		if ($excludeParent) {
-			unset($ids[0]);
-		}
+            $result = $query->execute();
+            // Reset parents array, only go through loop again if items are found
+            $parents = [];
+            while ($item = $result->fetch()) {
+                $tmpItem = [
+                    'id' => $item['id'],
+                    'shareWith' => $item['share_with'],
+                    'itemTarget' => $item['item_target'],
+                    'itemType' => $item['item_type'],
+                    'shareType' => (int)$item['share_type'],
+                ];
+                if (isset($item['file_target'])) {
+                    $tmpItem['fileTarget'] = $item['file_target'];
+                }
+                // if we have a new parent for the child we remember the child
+                // to update the parent, if not we add it to the list of items
+                // which should be deleted
+                if ($newParent !== null) {
+                    $changeParent[] = $item['id'];
+                } else {
+                    $deletedItems[] = $tmpItem;
+                    $ids[] = $item['id'];
+                    $parents[] = $item['id'];
+                }
+            }
+            $result->closeCursor();
+        }
+        if ($excludeParent) {
+            unset($ids[0]);
+        }
 
-		if (!empty($changeParent)) {
-			$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
-			$query->update('share')
-				->set('parent', $query->createNamedParameter($newParent, IQueryBuilder::PARAM_INT))
-				->where($query->expr()->in('id', $query->createNamedParameter($changeParent, IQueryBuilder::PARAM_INT_ARRAY)));
-			$query->execute();
-		}
+        if (!empty($changeParent)) {
+            $query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+            $query->update('share')
+                ->set('parent', $query->createNamedParameter($newParent, IQueryBuilder::PARAM_INT))
+                ->where($query->expr()->in('id', $query->createNamedParameter($changeParent, IQueryBuilder::PARAM_INT_ARRAY)));
+            $query->execute();
+        }
 
-		if (!empty($ids)) {
-			$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
-			$query->delete('share')
-				->where($query->expr()->in('id', $query->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
-			$query->execute();
-		}
+        if (!empty($ids)) {
+            $query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+            $query->delete('share')
+                ->where($query->expr()->in('id', $query->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
+            $query->execute();
+        }
 
-		return $deletedItems;
-	}
+        return $deletedItems;
+    }
 
-	/**
-	 * get default expire settings defined by the admin
-	 * @return array contains 'defaultExpireDateSet', 'enforceExpireDate', 'expireAfterDays'
-	 */
-	public static function getDefaultExpireSetting() {
-		$config = \OC::$server->getConfig();
+    /**
+     * get default expire settings defined by the admin
+     * @return array contains 'defaultExpireDateSet', 'enforceExpireDate', 'expireAfterDays'
+     */
+    public static function getDefaultExpireSetting() {
+        $config = \OC::$server->getConfig();
 
-		$defaultExpireSettings = ['defaultExpireDateSet' => false];
+        $defaultExpireSettings = ['defaultExpireDateSet' => false];
 
-		// get default expire settings
-		$defaultExpireDate = $config->getAppValue('core', 'shareapi_default_expire_date', 'no');
-		if ($defaultExpireDate === 'yes') {
-			$enforceExpireDate = $config->getAppValue('core', 'shareapi_enforce_expire_date', 'no');
-			$defaultExpireSettings['defaultExpireDateSet'] = true;
-			$defaultExpireSettings['expireAfterDays'] = (int)$config->getAppValue('core', 'shareapi_expire_after_n_days', '7');
-			$defaultExpireSettings['enforceExpireDate'] = $enforceExpireDate === 'yes';
-		}
+        // get default expire settings
+        $defaultExpireDate = $config->getAppValue('core', 'shareapi_default_expire_date', 'no');
+        if ($defaultExpireDate === 'yes') {
+            $enforceExpireDate = $config->getAppValue('core', 'shareapi_enforce_expire_date', 'no');
+            $defaultExpireSettings['defaultExpireDateSet'] = true;
+            $defaultExpireSettings['expireAfterDays'] = (int)$config->getAppValue('core', 'shareapi_expire_after_n_days', '7');
+            $defaultExpireSettings['enforceExpireDate'] = $enforceExpireDate === 'yes';
+        }
 
-		return $defaultExpireSettings;
-	}
+        return $defaultExpireSettings;
+    }
 
-	public static function calcExpireDate() {
-		$expireAfter = \OC\Share\Share::getExpireInterval() * 24 * 60 * 60;
-		$expireAt = time() + $expireAfter;
-		$date = new \DateTime();
-		$date->setTimestamp($expireAt);
-		$date->setTime(0, 0, 0);
-		//$dateString = $date->format('Y-m-d') . ' 00:00:00';
+    public static function calcExpireDate() {
+        $expireAfter = \OC\Share\Share::getExpireInterval() * 24 * 60 * 60;
+        $expireAt = time() + $expireAfter;
+        $date = new \DateTime();
+        $date->setTimestamp($expireAt);
+        $date->setTime(0, 0, 0);
+        //$dateString = $date->format('Y-m-d') . ' 00:00:00';
 
-		return $date;
-	}
+        return $date;
+    }
 
-	/**
-	 * calculate expire date
-	 * @param array $defaultExpireSettings contains 'defaultExpireDateSet', 'enforceExpireDate', 'expireAfterDays'
-	 * @param int $creationTime timestamp when the share was created
-	 * @param int $userExpireDate expire timestamp set by the user
-	 * @return mixed integer timestamp or False
-	 */
-	public static function calculateExpireDate($defaultExpireSettings, $creationTime, $userExpireDate = null) {
-		$expires = false;
-		$defaultExpires = null;
+    /**
+     * calculate expire date
+     * @param array $defaultExpireSettings contains 'defaultExpireDateSet', 'enforceExpireDate', 'expireAfterDays'
+     * @param int $creationTime timestamp when the share was created
+     * @param int $userExpireDate expire timestamp set by the user
+     * @return mixed integer timestamp or False
+     */
+    public static function calculateExpireDate($defaultExpireSettings, $creationTime, $userExpireDate = null) {
+        $expires = false;
+        $defaultExpires = null;
 
-		if (!empty($defaultExpireSettings['defaultExpireDateSet'])) {
-			$defaultExpires = $creationTime + $defaultExpireSettings['expireAfterDays'] * 86400;
-		}
+        if (!empty($defaultExpireSettings['defaultExpireDateSet'])) {
+            $defaultExpires = $creationTime + $defaultExpireSettings['expireAfterDays'] * 86400;
+        }
 
 
-		if (isset($userExpireDate)) {
-			// if the admin decided to enforce the default expire date then we only take
-			// the user defined expire date of it is before the default expire date
-			if ($defaultExpires && !empty($defaultExpireSettings['enforceExpireDate'])) {
-				$expires = min($userExpireDate, $defaultExpires);
-			} else {
-				$expires = $userExpireDate;
-			}
-		} elseif ($defaultExpires && !empty($defaultExpireSettings['enforceExpireDate'])) {
-			$expires = $defaultExpires;
-		}
+        if (isset($userExpireDate)) {
+            // if the admin decided to enforce the default expire date then we only take
+            // the user defined expire date of it is before the default expire date
+            if ($defaultExpires && !empty($defaultExpireSettings['enforceExpireDate'])) {
+                $expires = min($userExpireDate, $defaultExpires);
+            } else {
+                $expires = $userExpireDate;
+            }
+        } elseif ($defaultExpires && !empty($defaultExpireSettings['enforceExpireDate'])) {
+            $expires = $defaultExpires;
+        }
 
-		return $expires;
-	}
+        return $expires;
+    }
 
-	/**
-	 * Strips away a potential file names and trailing slashes:
-	 * - http://localhost
-	 * - http://localhost/
-	 * - http://localhost/index.php
-	 * - http://localhost/index.php/s/{shareToken}
-	 *
-	 * all return: http://localhost
-	 *
-	 * @param string $remote
-	 * @return string
-	 */
-	protected static function fixRemoteURL($remote) {
-		$remote = str_replace('\\', '/', $remote);
-		if ($fileNamePosition = strpos($remote, '/index.php')) {
-			$remote = substr($remote, 0, $fileNamePosition);
-		}
-		$remote = rtrim($remote, '/');
+    /**
+     * Strips away a potential file names and trailing slashes:
+     * - http://localhost
+     * - http://localhost/
+     * - http://localhost/index.php
+     * - http://localhost/index.php/s/{shareToken}
+     *
+     * all return: http://localhost
+     *
+     * @param string $remote
+     * @return string
+     */
+    protected static function fixRemoteURL($remote) {
+        $remote = str_replace('\\', '/', $remote);
+        if ($fileNamePosition = strpos($remote, '/index.php')) {
+            $remote = substr($remote, 0, $fileNamePosition);
+        }
+        $remote = rtrim($remote, '/');
 
-		return $remote;
-	}
+        return $remote;
+    }
 
-	/**
-	 * split user and remote from federated cloud id
-	 *
-	 * @param string $id
-	 * @return string[]
-	 * @throws HintException
-	 */
-	public static function splitUserRemote($id) {
-		try {
-			$cloudId = \OC::$server->getCloudIdManager()->resolveCloudId($id);
-			return [$cloudId->getUser(), $cloudId->getRemote()];
-		} catch (\InvalidArgumentException $e) {
-			$l = \OC::$server->getL10N('core');
-			$hint = $l->t('Invalid Federated Cloud ID');
-			throw new HintException('Invalid Federated Cloud ID', $hint, 0, $e);
-		}
-	}
+    /**
+     * split user and remote from federated cloud id
+     *
+     * @param string $id
+     * @return string[]
+     * @throws HintException
+     */
+    public static function splitUserRemote($id) {
+        try {
+            $cloudId = \OC::$server->getCloudIdManager()->resolveCloudId($id);
+            return [$cloudId->getUser(), $cloudId->getRemote()];
+        } catch (\InvalidArgumentException $e) {
+            $l = \OC::$server->getL10N('core');
+            $hint = $l->t('Invalid Federated Cloud ID');
+            throw new HintException('Invalid Federated Cloud ID', $hint, 0, $e);
+        }
+    }
 
-	/**
-	 * check if two federated cloud IDs refer to the same user
-	 *
-	 * @param string $user1
-	 * @param string $server1
-	 * @param string $user2
-	 * @param string $server2
-	 * @return bool true if both users and servers are the same
-	 */
-	public static function isSameUserOnSameServer($user1, $server1, $user2, $server2) {
-		$normalizedServer1 = strtolower(\OC\Share\Share::removeProtocolFromUrl($server1));
-		$normalizedServer2 = strtolower(\OC\Share\Share::removeProtocolFromUrl($server2));
+    /**
+     * check if two federated cloud IDs refer to the same user
+     *
+     * @param string $user1
+     * @param string $server1
+     * @param string $user2
+     * @param string $server2
+     * @return bool true if both users and servers are the same
+     */
+    public static function isSameUserOnSameServer($user1, $server1, $user2, $server2) {
+        $normalizedServer1 = strtolower(\OC\Share\Share::removeProtocolFromUrl($server1));
+        $normalizedServer2 = strtolower(\OC\Share\Share::removeProtocolFromUrl($server2));
 
-		if (rtrim($normalizedServer1, '/') === rtrim($normalizedServer2, '/')) {
-			// FIXME this should be a method in the user management instead
-			\OCP\Util::emitHook(
-					'\OCA\Files_Sharing\API\Server2Server',
-					'preLoginNameUsedAsUserName',
-					['uid' => &$user1]
-			);
-			\OCP\Util::emitHook(
-					'\OCA\Files_Sharing\API\Server2Server',
-					'preLoginNameUsedAsUserName',
-					['uid' => &$user2]
-			);
+        if (rtrim($normalizedServer1, '/') === rtrim($normalizedServer2, '/')) {
+            // FIXME this should be a method in the user management instead
+            \OCP\Util::emitHook(
+                    '\OCA\Files_Sharing\API\Server2Server',
+                    'preLoginNameUsedAsUserName',
+                    ['uid' => &$user1]
+            );
+            \OCP\Util::emitHook(
+                    '\OCA\Files_Sharing\API\Server2Server',
+                    'preLoginNameUsedAsUserName',
+                    ['uid' => &$user2]
+            );
 
-			if ($user1 === $user2) {
-				return true;
-			}
-		}
+            if ($user1 === $user2) {
+                return true;
+            }
+        }
 
-		return false;
-	}
+        return false;
+    }
 }

Spacing +2 added lines, -2 removed lines

@@ -119,7 +119,7 @@ 
 					'shareWith' => $item['share_with'],
 					'itemTarget' => $item['item_target'],
 					'itemType' => $item['item_type'],
-					'shareType' => (int)$item['share_type'],
+					'shareType' => (int) $item['share_type'],
 				];
 				if (isset($item['file_target'])) {
 					$tmpItem['fileTarget'] = $item['file_target'];
@@ -173,7 +173,7 @@ 
 		if ($defaultExpireDate === 'yes') {
 			$enforceExpireDate = $config->getAppValue('core', 'shareapi_enforce_expire_date', 'no');
 			$defaultExpireSettings['defaultExpireDateSet'] = true;
-			$defaultExpireSettings['expireAfterDays'] = (int)$config->getAppValue('core', 'shareapi_expire_after_n_days', '7');
+			$defaultExpireSettings['expireAfterDays'] = (int) $config->getAppValue('core', 'shareapi_expire_after_n_days', '7');
 			$defaultExpireSettings['enforceExpireDate'] = $enforceExpireDate === 'yes';
 		}
 

lib/private/Share/Share.php

Indentation +1096 added lines, -1096 removed lines

@@ -50,1100 +50,1100 @@
  */
 class Share extends Constants {
 
-	/** CRUDS permissions (Create, Read, Update, Delete, Share) using a bitmask
-	 * Construct permissions for share() and setPermissions with Or (|) e.g.
-	 * Give user read and update permissions: PERMISSION_READ | PERMISSION_UPDATE
-	 *
-	 * Check if permission is granted with And (&) e.g. Check if delete is
-	 * granted: if ($permissions & PERMISSION_DELETE)
-	 *
-	 * Remove permissions with And (&) and Not (~) e.g. Remove the update
-	 * permission: $permissions &= ~PERMISSION_UPDATE
-	 *
-	 * Apps are required to handle permissions on their own, this class only
-	 * stores and manages the permissions of shares
-	 * @see lib/public/constants.php
-	 */
-
-	/**
-	 * Register a sharing backend class that implements OCP\Share_Backend for an item type
-	 * @param string $itemType Item type
-	 * @param string $class Backend class
-	 * @param string $collectionOf (optional) Depends on item type
-	 * @param array $supportedFileExtensions (optional) List of supported file extensions if this item type depends on files
-	 * @return boolean true if backend is registered or false if error
-	 */
-	public static function registerBackend($itemType, $class, $collectionOf = null, $supportedFileExtensions = null) {
-		if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_enabled', 'yes') == 'yes') {
-			if (!isset(self::$backendTypes[$itemType])) {
-				self::$backendTypes[$itemType] = [
-					'class' => $class,
-					'collectionOf' => $collectionOf,
-					'supportedFileExtensions' => $supportedFileExtensions
-				];
-				return true;
-			}
-			\OCP\Util::writeLog('OCP\Share',
-				'Sharing backend '.$class.' not registered, '.self::$backendTypes[$itemType]['class']
-				.' is already registered for '.$itemType,
-				ILogger::WARN);
-		}
-		return false;
-	}
-
-	/**
-	 * Get the items of item type shared with the current user
-	 * @param string $itemType
-	 * @param int $format (optional) Format type must be defined by the backend
-	 * @param mixed $parameters (optional)
-	 * @param int $limit Number of items to return (optional) Returns all by default
-	 * @param boolean $includeCollections (optional)
-	 * @return mixed Return depends on format
-	 * @deprecated TESTS ONLY - this methods is only used by tests
-	 * called like this:
-	 * \OC\Share\Share::getItemsSharedWith('folder'); (apps/files_sharing/tests/UpdaterTest.php)
-	 */
-	public static function getItemsSharedWith() {
-		return self::getItems('folder', null, self::$shareTypeUserAndGroups, \OC_User::getUser(), null, self::FORMAT_NONE,
-			null, -1, false);
-	}
-
-	/**
-	 * Get the items of item type shared with a user
-	 * @param string $itemType
-	 * @param string $user id for which user we want the shares
-	 * @param int $format (optional) Format type must be defined by the backend
-	 * @param mixed $parameters (optional)
-	 * @param int $limit Number of items to return (optional) Returns all by default
-	 * @param boolean $includeCollections (optional)
-	 * @return mixed Return depends on format
-	 */
-	public static function getItemsSharedWithUser($itemType, $user, $format = self::FORMAT_NONE,
-												  $parameters = null, $limit = -1, $includeCollections = false) {
-		return self::getItems($itemType, null, self::$shareTypeUserAndGroups, $user, null, $format,
-			$parameters, $limit, $includeCollections);
-	}
-
-	/**
-	 * Get the item of item type shared with a given user by source
-	 * @param string $itemType
-	 * @param string $itemSource
-	 * @param string $user User to whom the item was shared
-	 * @param string $owner Owner of the share
-	 * @param int $shareType only look for a specific share type
-	 * @return array Return list of items with file_target, permissions and expiration
-	 */
-	public static function getItemSharedWithUser($itemType, $itemSource, $user, $owner = null, $shareType = null) {
-		$shares = [];
-		$fileDependent = false;
-
-		$where = 'WHERE';
-		$fileDependentWhere = '';
-		if ($itemType === 'file' || $itemType === 'folder') {
-			$fileDependent = true;
-			$column = 'file_source';
-			$fileDependentWhere = 'INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` ';
-			$fileDependentWhere .= 'INNER JOIN `*PREFIX*storages` ON `numeric_id` = `*PREFIX*filecache`.`storage` ';
-		} else {
-			$column = 'item_source';
-		}
-
-		$select = self::createSelectStatement(self::FORMAT_NONE, $fileDependent);
-
-		$where .= ' `' . $column . '` = ? AND `item_type` = ? ';
-		$arguments = [$itemSource, $itemType];
-		// for link shares $user === null
-		if ($user !== null) {
-			$where .= ' AND `share_with` = ? ';
-			$arguments[] = $user;
-		}
-
-		if ($shareType !== null) {
-			$where .= ' AND `share_type` = ? ';
-			$arguments[] = $shareType;
-		}
-
-		if ($owner !== null) {
-			$where .= ' AND `uid_owner` = ? ';
-			$arguments[] = $owner;
-		}
-
-		$query = \OC_DB::prepare('SELECT ' . $select . ' FROM `*PREFIX*share` '. $fileDependentWhere . $where);
-
-		$result = \OC_DB::executeAudited($query, $arguments);
-
-		while ($row = $result->fetchRow()) {
-			if ($fileDependent && !self::isFileReachable($row['path'], $row['storage_id'])) {
-				continue;
-			}
-			if ($fileDependent && (int)$row['file_parent'] === -1) {
-				// if it is a mount point we need to get the path from the mount manager
-				$mountManager = \OC\Files\Filesystem::getMountManager();
-				$mountPoint = $mountManager->findByStorageId($row['storage_id']);
-				if (!empty($mountPoint)) {
-					$path = $mountPoint[0]->getMountPoint();
-					$path = trim($path, '/');
-					$path = substr($path, strlen($owner) + 1); //normalize path to 'files/foo.txt`
-					$row['path'] = $path;
-				} else {
-					\OC::$server->getLogger()->warning(
-						'Could not resolve mount point for ' . $row['storage_id'],
-						['app' => 'OCP\Share']
-					);
-				}
-			}
-			$shares[] = $row;
-		}
-
-		//if didn't found a result than let's look for a group share.
-		if (empty($shares) && $user !== null) {
-			$userObject = \OC::$server->getUserManager()->get($user);
-			$groups = [];
-			if ($userObject) {
-				$groups = \OC::$server->getGroupManager()->getUserGroupIds($userObject);
-			}
-
-			if (!empty($groups)) {
-				$where = $fileDependentWhere . ' WHERE `' . $column . '` = ? AND `item_type` = ? AND `share_with` in (?)';
-				$arguments = [$itemSource, $itemType, $groups];
-				$types = [null, null, IQueryBuilder::PARAM_STR_ARRAY];
-
-				if ($owner !== null) {
-					$where .= ' AND `uid_owner` = ?';
-					$arguments[] = $owner;
-					$types[] = null;
-				}
-
-				// TODO: inject connection, hopefully one day in the future when this
-				// class isn't static anymore...
-				$conn = \OC::$server->getDatabaseConnection();
-				$result = $conn->executeQuery(
-					'SELECT ' . $select . ' FROM `*PREFIX*share` ' . $where,
-					$arguments,
-					$types
-				);
-
-				while ($row = $result->fetch()) {
-					$shares[] = $row;
-				}
-			}
-		}
-
-		return $shares;
-	}
-
-	/**
-	 * Get the item of item type shared with the current user by source
-	 * @param string $itemType
-	 * @param string $itemSource
-	 * @param int $format (optional) Format type must be defined by the backend
-	 * @param mixed $parameters
-	 * @param boolean $includeCollections
-	 * @param string $shareWith (optional) define against which user should be checked, default: current user
-	 * @return array
-	 */
-	public static function getItemSharedWithBySource($itemType, $itemSource, $format = self::FORMAT_NONE,
-													 $parameters = null, $includeCollections = false, $shareWith = null) {
-		$shareWith = ($shareWith === null) ? \OC_User::getUser() : $shareWith;
-		return self::getItems($itemType, $itemSource, self::$shareTypeUserAndGroups, $shareWith, null, $format,
-			$parameters, 1, $includeCollections, true);
-	}
-
-	/**
-	 * Get the shared item of item type owned by the current user
-	 * @param string $itemType
-	 * @param string $itemSource
-	 * @param int $format (optional) Format type must be defined by the backend
-	 * @param mixed $parameters
-	 * @param boolean $includeCollections
-	 * @return mixed Return depends on format
-	 */
-	public static function getItemShared($itemType, $itemSource, $format = self::FORMAT_NONE,
-										 $parameters = null, $includeCollections = false) {
-		return self::getItems($itemType, $itemSource, null, null, \OC_User::getUser(), $format,
-			$parameters, -1, $includeCollections);
-	}
-
-	/**
-	 * Unshare an item from a user, group, or delete a private link
-	 * @param string $itemType
-	 * @param string $itemSource
-	 * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_LINK
-	 * @param string $shareWith User or group the item is being shared with
-	 * @param string $owner owner of the share, if null the current user is used
-	 * @return boolean true on success or false on failure
-	 */
-	public static function unshare($itemType, $itemSource, $shareType, $shareWith, $owner = null) {
-
-		// check if it is a valid itemType
-		self::getBackend($itemType);
-
-		$items = self::getItemSharedWithUser($itemType, $itemSource, $shareWith, $owner, $shareType);
-
-		$toDelete = [];
-		$newParent = null;
-		$currentUser = $owner ? $owner : \OC_User::getUser();
-		foreach ($items as $item) {
-			// delete the item with the expected share_type and owner
-			if ((int)$item['share_type'] === (int)$shareType && $item['uid_owner'] === $currentUser) {
-				$toDelete = $item;
-			// if there is more then one result we don't have to delete the children
-				// but update their parent. For group shares the new parent should always be
-				// the original group share and not the db entry with the unique name
-			} elseif ((int)$item['share_type'] === self::$shareTypeGroupUserUnique) {
-				$newParent = $item['parent'];
-			} else {
-				$newParent = $item['id'];
-			}
-		}
-
-		if (!empty($toDelete)) {
-			self::unshareItem($toDelete, $newParent);
-			return true;
-		}
-		return false;
-	}
-
-	/**
-	 * Checks whether a share has expired, calls unshareItem() if yes.
-	 * @param array $item Share data (usually database row)
-	 * @return boolean True if item was expired, false otherwise.
-	 */
-	protected static function expireItem(array $item) {
-		$result = false;
-
-		// only use default expiration date for link shares
-		if ((int) $item['share_type'] === IShare::TYPE_LINK) {
-
-			// calculate expiration date
-			if (!empty($item['expiration'])) {
-				$userDefinedExpire = new \DateTime($item['expiration']);
-				$expires = $userDefinedExpire->getTimestamp();
-			} else {
-				$expires = null;
-			}
-
-
-			// get default expiration settings
-			$defaultSettings = Helper::getDefaultExpireSetting();
-			$expires = Helper::calculateExpireDate($defaultSettings, $item['stime'], $expires);
-
-
-			if (is_int($expires)) {
-				$now = time();
-				if ($now > $expires) {
-					self::unshareItem($item);
-					$result = true;
-				}
-			}
-		}
-		return $result;
-	}
-
-	/**
-	 * Unshares a share given a share data array
-	 * @param array $item Share data (usually database row)
-	 * @param int $newParent parent ID
-	 * @return null
-	 */
-	protected static function unshareItem(array $item, $newParent = null) {
-		$shareType = (int)$item['share_type'];
-		$shareWith = null;
-		if ($shareType !== IShare::TYPE_LINK) {
-			$shareWith = $item['share_with'];
-		}
-
-		// Pass all the vars we have for now, they may be useful
-		$hookParams = [
-			'id' => $item['id'],
-			'itemType' => $item['item_type'],
-			'itemSource' => $item['item_source'],
-			'shareType' => $shareType,
-			'shareWith' => $shareWith,
-			'itemParent' => $item['parent'],
-			'uidOwner' => $item['uid_owner'],
-		];
-		if ($item['item_type'] === 'file' || $item['item_type'] === 'folder') {
-			$hookParams['fileSource'] = $item['file_source'];
-			$hookParams['fileTarget'] = $item['file_target'];
-		}
-
-		\OC_Hook::emit(\OCP\Share::class, 'pre_unshare', $hookParams);
-		$deletedShares = Helper::delete($item['id'], false, null, $newParent);
-		$deletedShares[] = $hookParams;
-		$hookParams['deletedShares'] = $deletedShares;
-		\OC_Hook::emit(\OCP\Share::class, 'post_unshare', $hookParams);
-		if ((int)$item['share_type'] === IShare::TYPE_REMOTE && \OC::$server->getUserSession()->getUser()) {
-			list(, $remote) = Helper::splitUserRemote($item['share_with']);
-			self::sendRemoteUnshare($remote, $item['id'], $item['token']);
-		}
-	}
-
-	/**
-	 * Get the backend class for the specified item type
-	 * @param string $itemType
-	 * @throws \Exception
-	 * @return \OCP\Share_Backend
-	 */
-	public static function getBackend($itemType) {
-		$l = \OC::$server->getL10N('lib');
-		if (isset(self::$backends[$itemType])) {
-			return self::$backends[$itemType];
-		} elseif (isset(self::$backendTypes[$itemType]['class'])) {
-			$class = self::$backendTypes[$itemType]['class'];
-			if (class_exists($class)) {
-				self::$backends[$itemType] = new $class;
-				if (!(self::$backends[$itemType] instanceof \OCP\Share_Backend)) {
-					$message = 'Sharing backend %s must implement the interface OCP\Share_Backend';
-					$message_t = $l->t('Sharing backend %s must implement the interface OCP\Share_Backend', [$class]);
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
-					throw new \Exception($message_t);
-				}
-				return self::$backends[$itemType];
-			} else {
-				$message = 'Sharing backend %s not found';
-				$message_t = $l->t('Sharing backend %s not found', [$class]);
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
-				throw new \Exception($message_t);
-			}
-		}
-		$message = 'Sharing backend for %s not found';
-		$message_t = $l->t('Sharing backend for %s not found', [$itemType]);
-		\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemType), ILogger::ERROR);
-		throw new \Exception($message_t);
-	}
-
-	/**
-	 * Check if resharing is allowed
-	 * @return boolean true if allowed or false
-	 *
-	 * Resharing is allowed by default if not configured
-	 */
-	public static function isResharingAllowed() {
-		if (!isset(self::$isResharingAllowed)) {
-			if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_allow_resharing', 'yes') == 'yes') {
-				self::$isResharingAllowed = true;
-			} else {
-				self::$isResharingAllowed = false;
-			}
-		}
-		return self::$isResharingAllowed;
-	}
-
-	/**
-	 * Get a list of collection item types for the specified item type
-	 * @param string $itemType
-	 * @return array
-	 */
-	private static function getCollectionItemTypes($itemType) {
-		$collectionTypes = [$itemType];
-		foreach (self::$backendTypes as $type => $backend) {
-			if (in_array($backend['collectionOf'], $collectionTypes)) {
-				$collectionTypes[] = $type;
-			}
-		}
-		// TODO Add option for collections to be collection of themselves, only 'folder' does it now...
-		if (isset(self::$backendTypes[$itemType]) && (!self::getBackend($itemType) instanceof \OCP\Share_Backend_Collection || $itemType != 'folder')) {
-			unset($collectionTypes[0]);
-		}
-		// Return array if collections were found or the item type is a
-		// collection itself - collections can be inside collections
-		if (count($collectionTypes) > 0) {
-			return $collectionTypes;
-		}
-		return false;
-	}
-
-	/**
-	 * Get shared items from the database
-	 * @param string $itemType
-	 * @param string $item Item source or target (optional)
-	 * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, SHARE_TYPE_LINK, $shareTypeUserAndGroups, or $shareTypeGroupUserUnique
-	 * @param string $shareWith User or group the item is being shared with
-	 * @param string $uidOwner User that is the owner of shared items (optional)
-	 * @param int $format Format to convert items to with formatItems() (optional)
-	 * @param mixed $parameters to pass to formatItems() (optional)
-	 * @param int $limit Number of items to return, -1 to return all matches (optional)
-	 * @param boolean $includeCollections Include collection item types (optional)
-	 * @param boolean $itemShareWithBySource (optional)
-	 * @param boolean $checkExpireDate
-	 * @return array
-	 *
-	 * See public functions getItem(s)... for parameter usage
-	 *
-	 */
-	public static function getItems($itemType, $item = null, $shareType = null, $shareWith = null,
-									$uidOwner = null, $format = self::FORMAT_NONE, $parameters = null, $limit = -1,
-									$includeCollections = false, $itemShareWithBySource = false, $checkExpireDate = true) {
-		if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_enabled', 'yes') != 'yes') {
-			return [];
-		}
-		$backend = self::getBackend($itemType);
-		$collectionTypes = false;
-		// Get filesystem root to add it to the file target and remove from the
-		// file source, match file_source with the file cache
-		if ($itemType == 'file' || $itemType == 'folder') {
-			if (!is_null($uidOwner)) {
-				$root = \OC\Files\Filesystem::getRoot();
-			} else {
-				$root = '';
-			}
-			$where = 'INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` ';
-			if (!isset($item)) {
-				$where .= ' AND `file_target` IS NOT NULL ';
-			}
-			$where .= 'INNER JOIN `*PREFIX*storages` ON `numeric_id` = `*PREFIX*filecache`.`storage` ';
-			$fileDependent = true;
-			$queryArgs = [];
-		} else {
-			$fileDependent = false;
-			$root = '';
-			$collectionTypes = self::getCollectionItemTypes($itemType);
-			if ($includeCollections && !isset($item) && $collectionTypes) {
-				// If includeCollections is true, find collections of this item type, e.g. a music album contains songs
-				if (!in_array($itemType, $collectionTypes)) {
-					$itemTypes = array_merge([$itemType], $collectionTypes);
-				} else {
-					$itemTypes = $collectionTypes;
-				}
-				$placeholders = implode(',', array_fill(0, count($itemTypes), '?'));
-				$where = ' WHERE `item_type` IN ('.$placeholders.'))';
-				$queryArgs = $itemTypes;
-			} else {
-				$where = ' WHERE `item_type` = ?';
-				$queryArgs = [$itemType];
-			}
-		}
-		if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_allow_links', 'yes') !== 'yes') {
-			$where .= ' AND `share_type` != ?';
-			$queryArgs[] = IShare::TYPE_LINK;
-		}
-		if (isset($shareType)) {
-			// Include all user and group items
-			if ($shareType == self::$shareTypeUserAndGroups && isset($shareWith)) {
-				$where .= ' AND ((`share_type` in (?, ?) AND `share_with` = ?) ';
-				$queryArgs[] = IShare::TYPE_USER;
-				$queryArgs[] = self::$shareTypeGroupUserUnique;
-				$queryArgs[] = $shareWith;
-
-				$user = \OC::$server->getUserManager()->get($shareWith);
-				$groups = [];
-				if ($user) {
-					$groups = \OC::$server->getGroupManager()->getUserGroupIds($user);
-				}
-				if (!empty($groups)) {
-					$placeholders = implode(',', array_fill(0, count($groups), '?'));
-					$where .= ' OR (`share_type` = ? AND `share_with` IN ('.$placeholders.')) ';
-					$queryArgs[] = IShare::TYPE_GROUP;
-					$queryArgs = array_merge($queryArgs, $groups);
-				}
-				$where .= ')';
-				// Don't include own group shares
-				$where .= ' AND `uid_owner` != ?';
-				$queryArgs[] = $shareWith;
-			} else {
-				$where .= ' AND `share_type` = ?';
-				$queryArgs[] = $shareType;
-				if (isset($shareWith)) {
-					$where .= ' AND `share_with` = ?';
-					$queryArgs[] = $shareWith;
-				}
-			}
-		}
-		if (isset($uidOwner)) {
-			$where .= ' AND `uid_owner` = ?';
-			$queryArgs[] = $uidOwner;
-			if (!isset($shareType)) {
-				// Prevent unique user targets for group shares from being selected
-				$where .= ' AND `share_type` != ?';
-				$queryArgs[] = self::$shareTypeGroupUserUnique;
-			}
-			if ($fileDependent) {
-				$column = 'file_source';
-			} else {
-				$column = 'item_source';
-			}
-		} else {
-			if ($fileDependent) {
-				$column = 'file_target';
-			} else {
-				$column = 'item_target';
-			}
-		}
-		if (isset($item)) {
-			$collectionTypes = self::getCollectionItemTypes($itemType);
-			if ($includeCollections && $collectionTypes && !in_array('folder', $collectionTypes)) {
-				$where .= ' AND (';
-			} else {
-				$where .= ' AND';
-			}
-			// If looking for own shared items, check item_source else check item_target
-			if (isset($uidOwner) || $itemShareWithBySource) {
-				// If item type is a file, file source needs to be checked in case the item was converted
-				if ($fileDependent) {
-					$where .= ' `file_source` = ?';
-					$column = 'file_source';
-				} else {
-					$where .= ' `item_source` = ?';
-					$column = 'item_source';
-				}
-			} else {
-				if ($fileDependent) {
-					$where .= ' `file_target` = ?';
-					$item = \OC\Files\Filesystem::normalizePath($item);
-				} else {
-					$where .= ' `item_target` = ?';
-				}
-			}
-			$queryArgs[] = $item;
-			if ($includeCollections && $collectionTypes && !in_array('folder', $collectionTypes)) {
-				$placeholders = implode(',', array_fill(0, count($collectionTypes), '?'));
-				$where .= ' OR `item_type` IN ('.$placeholders.'))';
-				$queryArgs = array_merge($queryArgs, $collectionTypes);
-			}
-		}
-
-		if ($shareType == self::$shareTypeUserAndGroups && $limit === 1) {
-			// Make sure the unique user target is returned if it exists,
-			// unique targets should follow the group share in the database
-			// If the limit is not 1, the filtering can be done later
-			$where .= ' ORDER BY `*PREFIX*share`.`id` DESC';
-		} else {
-			$where .= ' ORDER BY `*PREFIX*share`.`id` ASC';
-		}
-
-		if ($limit != -1 && !$includeCollections) {
-			// The limit must be at least 3, because filtering needs to be done
-			if ($limit < 3) {
-				$queryLimit = 3;
-			} else {
-				$queryLimit = $limit;
-			}
-		} else {
-			$queryLimit = null;
-		}
-		$select = self::createSelectStatement($format, $fileDependent, $uidOwner);
-		$root = strlen($root);
-		$query = \OC_DB::prepare('SELECT '.$select.' FROM `*PREFIX*share` '.$where, $queryLimit);
-		$result = $query->execute($queryArgs);
-		if ($result === false) {
-			\OCP\Util::writeLog('OCP\Share',
-				\OC_DB::getErrorMessage() . ', select=' . $select . ' where=',
-				ILogger::ERROR);
-		}
-		$items = [];
-		$targets = [];
-		$switchedItems = [];
-		$mounts = [];
-		while ($row = $result->fetchRow()) {
-			self::transformDBResults($row);
-			// Filter out duplicate group shares for users with unique targets
-			if ($fileDependent && !self::isFileReachable($row['path'], $row['storage_id'])) {
-				continue;
-			}
-			if ($row['share_type'] == self::$shareTypeGroupUserUnique && isset($items[$row['parent']])) {
-				$row['share_type'] = IShare::TYPE_GROUP;
-				$row['unique_name'] = true; // remember that we use a unique name for this user
-				$row['share_with'] = $items[$row['parent']]['share_with'];
-				// if the group share was unshared from the user we keep the permission, otherwise
-				// we take the permission from the parent because this is always the up-to-date
-				// permission for the group share
-				if ($row['permissions'] > 0) {
-					$row['permissions'] = $items[$row['parent']]['permissions'];
-				}
-				// Remove the parent group share
-				unset($items[$row['parent']]);
-				if ($row['permissions'] == 0) {
-					continue;
-				}
-			} elseif (!isset($uidOwner)) {
-				// Check if the same target already exists
-				if (isset($targets[$row['id']])) {
-					// Check if the same owner shared with the user twice
-					// through a group and user share - this is allowed
-					$id = $targets[$row['id']];
-					if (isset($items[$id]) && $items[$id]['uid_owner'] == $row['uid_owner']) {
-						// Switch to group share type to ensure resharing conditions aren't bypassed
-						if ($items[$id]['share_type'] != IShare::TYPE_GROUP) {
-							$items[$id]['share_type'] = IShare::TYPE_GROUP;
-							$items[$id]['share_with'] = $row['share_with'];
-						}
-						// Switch ids if sharing permission is granted on only
-						// one share to ensure correct parent is used if resharing
-						if (~(int)$items[$id]['permissions'] & \OCP\Constants::PERMISSION_SHARE
-							&& (int)$row['permissions'] & \OCP\Constants::PERMISSION_SHARE) {
-							$items[$row['id']] = $items[$id];
-							$switchedItems[$id] = $row['id'];
-							unset($items[$id]);
-							$id = $row['id'];
-						}
-						$items[$id]['permissions'] |= (int)$row['permissions'];
-					}
-					continue;
-				} elseif (!empty($row['parent'])) {
-					$targets[$row['parent']] = $row['id'];
-				}
-			}
-			// Remove root from file source paths if retrieving own shared items
-			if (isset($uidOwner) && isset($row['path'])) {
-				if (isset($row['parent'])) {
-					$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
-					$query->select('file_target')
-						->from('share')
-						->where($query->expr()->eq('id', $query->createNamedParameter($row['parent'])));
-
-					$result = $query->execute();
-					$parentRow = $result->fetch();
-					$result->closeCursor();
-
-					if ($parentRow === false) {
-						\OCP\Util::writeLog('OCP\Share', 'Can\'t select parent: ' .
-							\OC_DB::getErrorMessage() . ', select=' . $select . ' where=' . $where,
-							ILogger::ERROR);
-					} else {
-						$tmpPath = $parentRow['file_target'];
-						// find the right position where the row path continues from the target path
-						$pos = strrpos($row['path'], $parentRow['file_target']);
-						$subPath = substr($row['path'], $pos);
-						$splitPath = explode('/', $subPath);
-						foreach (array_slice($splitPath, 2) as $pathPart) {
-							$tmpPath = $tmpPath . '/' . $pathPart;
-						}
-						$row['path'] = $tmpPath;
-					}
-				} else {
-					if (!isset($mounts[$row['storage']])) {
-						$mountPoints = \OC\Files\Filesystem::getMountByNumericId($row['storage']);
-						if (is_array($mountPoints) && !empty($mountPoints)) {
-							$mounts[$row['storage']] = current($mountPoints);
-						}
-					}
-					if (!empty($mounts[$row['storage']])) {
-						$path = $mounts[$row['storage']]->getMountPoint().$row['path'];
-						$relPath = substr($path, $root); // path relative to data/user
-						$row['path'] = rtrim($relPath, '/');
-					}
-				}
-			}
-
-			if ($checkExpireDate) {
-				if (self::expireItem($row)) {
-					continue;
-				}
-			}
-			// Check if resharing is allowed, if not remove share permission
-			if (isset($row['permissions']) && (!self::isResharingAllowed() | \OCP\Util::isSharingDisabledForUser())) {
-				$row['permissions'] &= ~\OCP\Constants::PERMISSION_SHARE;
-			}
-			// Add display names to result
-			$row['share_with_displayname'] = $row['share_with'];
-			if (isset($row['share_with']) && $row['share_with'] != '' &&
-				$row['share_type'] === IShare::TYPE_USER) {
-				$shareWithUser = \OC::$server->getUserManager()->get($row['share_with']);
-				$row['share_with_displayname'] = $shareWithUser === null ? $row['share_with'] : $shareWithUser->getDisplayName();
-			} elseif (isset($row['share_with']) && $row['share_with'] != '' &&
-				$row['share_type'] === IShare::TYPE_REMOTE) {
-				$addressBookEntries = \OC::$server->getContactsManager()->search($row['share_with'], ['CLOUD']);
-				foreach ($addressBookEntries as $entry) {
-					foreach ($entry['CLOUD'] as $cloudID) {
-						if ($cloudID === $row['share_with']) {
-							$row['share_with_displayname'] = $entry['FN'];
-						}
-					}
-				}
-			}
-			if (isset($row['uid_owner']) && $row['uid_owner'] != '') {
-				$ownerUser = \OC::$server->getUserManager()->get($row['uid_owner']);
-				$row['displayname_owner'] = $ownerUser === null ? $row['uid_owner'] : $ownerUser->getDisplayName();
-			}
-
-			if ($row['permissions'] > 0) {
-				$items[$row['id']] = $row;
-			}
-		}
-
-		// group items if we are looking for items shared with the current user
-		if (isset($shareWith) && $shareWith === \OCP\User::getUser()) {
-			$items = self::groupItems($items, $itemType);
-		}
-
-		if (!empty($items)) {
-			$collectionItems = [];
-			foreach ($items as &$row) {
-				// Return only the item instead of a 2-dimensional array
-				if ($limit == 1 && $row[$column] == $item && ($row['item_type'] == $itemType || $itemType == 'file')) {
-					if ($format == self::FORMAT_NONE) {
-						return $row;
-					} else {
-						break;
-					}
-				}
-				// Check if this is a collection of the requested item type
-				if ($includeCollections && $collectionTypes && $row['item_type'] !== 'folder' && in_array($row['item_type'], $collectionTypes)) {
-					if (($collectionBackend = self::getBackend($row['item_type']))
-						&& $collectionBackend instanceof \OCP\Share_Backend_Collection) {
-						// Collections can be inside collections, check if the item is a collection
-						if (isset($item) && $row['item_type'] == $itemType && $row[$column] == $item) {
-							$collectionItems[] = $row;
-						} else {
-							$collection = [];
-							$collection['item_type'] = $row['item_type'];
-							if ($row['item_type'] == 'file' || $row['item_type'] == 'folder') {
-								$collection['path'] = basename($row['path']);
-							}
-							$row['collection'] = $collection;
-							// Fetch all of the children sources
-							$children = $collectionBackend->getChildren($row[$column]);
-							foreach ($children as $child) {
-								$childItem = $row;
-								$childItem['item_type'] = $itemType;
-								if ($row['item_type'] != 'file' && $row['item_type'] != 'folder') {
-									$childItem['item_source'] = $child['source'];
-									$childItem['item_target'] = $child['target'];
-								}
-								if ($backend instanceof \OCP\Share_Backend_File_Dependent) {
-									if ($row['item_type'] == 'file' || $row['item_type'] == 'folder') {
-										$childItem['file_source'] = $child['source'];
-									} else { // TODO is this really needed if we already know that we use the file backend?
-										$meta = \OC\Files\Filesystem::getFileInfo($child['file_path']);
-										$childItem['file_source'] = $meta['fileid'];
-									}
-									$childItem['file_target'] =
-										\OC\Files\Filesystem::normalizePath($child['file_path']);
-								}
-								if (isset($item)) {
-									if ($childItem[$column] == $item) {
-										// Return only the item instead of a 2-dimensional array
-										if ($limit == 1) {
-											if ($format == self::FORMAT_NONE) {
-												return $childItem;
-											} else {
-												// Unset the items array and break out of both loops
-												$items = [];
-												$items[] = $childItem;
-												break 2;
-											}
-										} else {
-											$collectionItems[] = $childItem;
-										}
-									}
-								} else {
-									$collectionItems[] = $childItem;
-								}
-							}
-						}
-					}
-					// Remove collection item
-					$toRemove = $row['id'];
-					if (array_key_exists($toRemove, $switchedItems)) {
-						$toRemove = $switchedItems[$toRemove];
-					}
-					unset($items[$toRemove]);
-				} elseif ($includeCollections && $collectionTypes && in_array($row['item_type'], $collectionTypes)) {
-					// FIXME: Thats a dirty hack to improve file sharing performance,
-					// see github issue #10588 for more details
-					// Need to find a solution which works for all back-ends
-					$collectionBackend = self::getBackend($row['item_type']);
-					$sharedParents = $collectionBackend->getParents($row['item_source']);
-					foreach ($sharedParents as $parent) {
-						$collectionItems[] = $parent;
-					}
-				}
-			}
-			if (!empty($collectionItems)) {
-				$collectionItems = array_unique($collectionItems, SORT_REGULAR);
-				$items = array_merge($items, $collectionItems);
-			}
-
-			// filter out invalid items, these can appear when subshare entries exist
-			// for a group in which the requested user isn't a member any more
-			$items = array_filter($items, function ($item) {
-				return $item['share_type'] !== self::$shareTypeGroupUserUnique;
-			});
-
-			return self::formatResult($items, $column, $backend, $format, $parameters);
-		} elseif ($includeCollections && $collectionTypes && in_array('folder', $collectionTypes)) {
-			// FIXME: Thats a dirty hack to improve file sharing performance,
-			// see github issue #10588 for more details
-			// Need to find a solution which works for all back-ends
-			$collectionItems = [];
-			$collectionBackend = self::getBackend('folder');
-			$sharedParents = $collectionBackend->getParents($item, $shareWith, $uidOwner);
-			foreach ($sharedParents as $parent) {
-				$collectionItems[] = $parent;
-			}
-			if ($limit === 1) {
-				return reset($collectionItems);
-			}
-			return self::formatResult($collectionItems, $column, $backend, $format, $parameters);
-		}
-
-		return [];
-	}
-
-	/**
-	 * group items with link to the same source
-	 *
-	 * @param array $items
-	 * @param string $itemType
-	 * @return array of grouped items
-	 */
-	protected static function groupItems($items, $itemType) {
-		$fileSharing = $itemType === 'file' || $itemType === 'folder';
-
-		$result = [];
-
-		foreach ($items as $item) {
-			$grouped = false;
-			foreach ($result as $key => $r) {
-				// for file/folder shares we need to compare file_source, otherwise we compare item_source
-				// only group shares if they already point to the same target, otherwise the file where shared
-				// before grouping of shares was added. In this case we don't group them toi avoid confusions
-				if (($fileSharing && $item['file_source'] === $r['file_source'] && $item['file_target'] === $r['file_target']) ||
-					(!$fileSharing && $item['item_source'] === $r['item_source'] && $item['item_target'] === $r['item_target'])) {
-					// add the first item to the list of grouped shares
-					if (!isset($result[$key]['grouped'])) {
-						$result[$key]['grouped'][] = $result[$key];
-					}
-					$result[$key]['permissions'] = (int) $item['permissions'] | (int) $r['permissions'];
-					$result[$key]['grouped'][] = $item;
-					$grouped = true;
-					break;
-				}
-			}
-
-			if (!$grouped) {
-				$result[] = $item;
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * construct select statement
-	 * @param int $format
-	 * @param boolean $fileDependent ist it a file/folder share or a generla share
-	 * @param string $uidOwner
-	 * @return string select statement
-	 */
-	private static function createSelectStatement($format, $fileDependent, $uidOwner = null) {
-		$select = '*';
-		if ($format == self::FORMAT_STATUSES) {
-			if ($fileDependent) {
-				$select = '`*PREFIX*share`.`id`, `*PREFIX*share`.`parent`, `share_type`, `path`, `storage`, '
-					. '`share_with`, `uid_owner` , `file_source`, `stime`, `*PREFIX*share`.`permissions`, '
-					. '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`, '
-					. '`uid_initiator`';
-			} else {
-				$select = '`id`, `parent`, `share_type`, `share_with`, `uid_owner`, `item_source`, `stime`, `*PREFIX*share`.`permissions`';
-			}
-		} else {
-			if (isset($uidOwner)) {
-				if ($fileDependent) {
-					$select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `*PREFIX*share`.`parent`,'
-						. ' `share_type`, `share_with`, `file_source`, `file_target`, `path`, `*PREFIX*share`.`permissions`, `stime`,'
-						. ' `expiration`, `token`, `storage`, `mail_send`, `uid_owner`, '
-						. '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`';
-				} else {
-					$select = '`id`, `item_type`, `item_source`, `parent`, `share_type`, `share_with`, `*PREFIX*share`.`permissions`,'
-						. ' `stime`, `file_source`, `expiration`, `token`, `mail_send`, `uid_owner`';
-				}
-			} else {
-				if ($fileDependent) {
-					if ($format == \OCA\Files_Sharing\ShareBackend\File::FORMAT_GET_FOLDER_CONTENTS || $format == \OCA\Files_Sharing\ShareBackend\File::FORMAT_FILE_APP_ROOT) {
-						$select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `*PREFIX*share`.`parent`, `uid_owner`, '
-							. '`share_type`, `share_with`, `file_source`, `path`, `file_target`, `stime`, '
-							. '`*PREFIX*share`.`permissions`, `expiration`, `storage`, `*PREFIX*filecache`.`parent` as `file_parent`, '
-							. '`name`, `mtime`, `mimetype`, `mimepart`, `size`, `encrypted`, `etag`, `mail_send`';
-					} else {
-						$select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `item_target`,'
-							. '`*PREFIX*share`.`parent`, `share_type`, `share_with`, `uid_owner`,'
-							. '`file_source`, `path`, `file_target`, `*PREFIX*share`.`permissions`,'
-							. '`stime`, `expiration`, `token`, `storage`, `mail_send`,'
-							. '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`';
-					}
-				}
-			}
-		}
-		return $select;
-	}
-
-
-	/**
-	 * transform db results
-	 * @param array $row result
-	 */
-	private static function transformDBResults(&$row) {
-		if (isset($row['id'])) {
-			$row['id'] = (int) $row['id'];
-		}
-		if (isset($row['share_type'])) {
-			$row['share_type'] = (int) $row['share_type'];
-		}
-		if (isset($row['parent'])) {
-			$row['parent'] = (int) $row['parent'];
-		}
-		if (isset($row['file_parent'])) {
-			$row['file_parent'] = (int) $row['file_parent'];
-		}
-		if (isset($row['file_source'])) {
-			$row['file_source'] = (int) $row['file_source'];
-		}
-		if (isset($row['permissions'])) {
-			$row['permissions'] = (int) $row['permissions'];
-		}
-		if (isset($row['storage'])) {
-			$row['storage'] = (int) $row['storage'];
-		}
-		if (isset($row['stime'])) {
-			$row['stime'] = (int) $row['stime'];
-		}
-		if (isset($row['expiration']) && $row['share_type'] !== IShare::TYPE_LINK) {
-			// discard expiration date for non-link shares, which might have been
-			// set by ancient bugs
-			$row['expiration'] = null;
-		}
-	}
-
-	/**
-	 * format result
-	 * @param array $items result
-	 * @param string $column is it a file share or a general share ('file_target' or 'item_target')
-	 * @param \OCP\Share_Backend $backend sharing backend
-	 * @param int $format
-	 * @param array $parameters additional format parameters
-	 * @return array format result
-	 */
-	private static function formatResult($items, $column, $backend, $format = self::FORMAT_NONE , $parameters = null) {
-		if ($format === self::FORMAT_NONE) {
-			return $items;
-		} elseif ($format === self::FORMAT_STATUSES) {
-			$statuses = [];
-			foreach ($items as $item) {
-				if ($item['share_type'] === IShare::TYPE_LINK) {
-					if ($item['uid_initiator'] !== \OC::$server->getUserSession()->getUser()->getUID()) {
-						continue;
-					}
-					$statuses[$item[$column]]['link'] = true;
-				} elseif (!isset($statuses[$item[$column]])) {
-					$statuses[$item[$column]]['link'] = false;
-				}
-				if (!empty($item['file_target'])) {
-					$statuses[$item[$column]]['path'] = $item['path'];
-				}
-			}
-			return $statuses;
-		} else {
-			return $backend->formatItems($items, $format, $parameters);
-		}
-	}
-
-	/**
-	 * remove protocol from URL
-	 *
-	 * @param string $url
-	 * @return string
-	 */
-	public static function removeProtocolFromUrl($url) {
-		if (strpos($url, 'https://') === 0) {
-			return substr($url, strlen('https://'));
-		} elseif (strpos($url, 'http://') === 0) {
-			return substr($url, strlen('http://'));
-		}
-
-		return $url;
-	}
-
-	/**
-	 * try http post first with https and then with http as a fallback
-	 *
-	 * @param string $remoteDomain
-	 * @param string $urlSuffix
-	 * @param array $fields post parameters
-	 * @return array
-	 */
-	private static function tryHttpPostToShareEndpoint($remoteDomain, $urlSuffix, array $fields) {
-		$protocol = 'https://';
-		$result = [
-			'success' => false,
-			'result' => '',
-		];
-		$try = 0;
-		$discoveryService = \OC::$server->query(\OCP\OCS\IDiscoveryService::class);
-		while ($result['success'] === false && $try < 2) {
-			$federationEndpoints = $discoveryService->discover($protocol . $remoteDomain, 'FEDERATED_SHARING');
-			$endpoint = isset($federationEndpoints['share']) ? $federationEndpoints['share'] : '/ocs/v2.php/cloud/shares';
-			$client = \OC::$server->getHTTPClientService()->newClient();
-
-			try {
-				$response = $client->post(
-					$protocol . $remoteDomain . $endpoint . $urlSuffix . '?format=' . self::RESPONSE_FORMAT,
-					[
-						'body' => $fields,
-						'connect_timeout' => 10,
-					]
-				);
-
-				$result = ['success' => true, 'result' => $response->getBody()];
-			} catch (\Exception $e) {
-				$result = ['success' => false, 'result' => $e->getMessage()];
-			}
-
-			$try++;
-			$protocol = 'http://';
-		}
-
-		return $result;
-	}
-
-	/**
-	 * send server-to-server unshare to remote server
-	 *
-	 * @param string $remote url
-	 * @param int $id share id
-	 * @param string $token
-	 * @return bool
-	 */
-	private static function sendRemoteUnshare($remote, $id, $token) {
-		$url = rtrim($remote, '/');
-		$fields = ['token' => $token, 'format' => 'json'];
-		$url = self::removeProtocolFromUrl($url);
-		$result = self::tryHttpPostToShareEndpoint($url, '/'.$id.'/unshare', $fields);
-		$status = json_decode($result['result'], true);
-
-		return ($result['success'] && ($status['ocs']['meta']['statuscode'] === 100 || $status['ocs']['meta']['statuscode'] === 200));
-	}
-
-	/**
-	 * @return int
-	 */
-	public static function getExpireInterval() {
-		return (int)\OC::$server->getConfig()->getAppValue('core', 'shareapi_expire_after_n_days', '7');
-	}
-
-	/**
-	 * Checks whether the given path is reachable for the given owner
-	 *
-	 * @param string $path path relative to files
-	 * @param string $ownerStorageId storage id of the owner
-	 *
-	 * @return boolean true if file is reachable, false otherwise
-	 */
-	private static function isFileReachable($path, $ownerStorageId) {
-		// if outside the home storage, file is always considered reachable
-		if (!(substr($ownerStorageId, 0, 6) === 'home::' ||
-			substr($ownerStorageId, 0, 13) === 'object::user:'
-		)) {
-			return true;
-		}
-
-		// if inside the home storage, the file has to be under "/files/"
-		$path = ltrim($path, '/');
-		if (substr($path, 0, 6) === 'files/') {
-			return true;
-		}
-
-		return false;
-	}
+    /** CRUDS permissions (Create, Read, Update, Delete, Share) using a bitmask
+     * Construct permissions for share() and setPermissions with Or (|) e.g.
+     * Give user read and update permissions: PERMISSION_READ | PERMISSION_UPDATE
+     *
+     * Check if permission is granted with And (&) e.g. Check if delete is
+     * granted: if ($permissions & PERMISSION_DELETE)
+     *
+     * Remove permissions with And (&) and Not (~) e.g. Remove the update
+     * permission: $permissions &= ~PERMISSION_UPDATE
+     *
+     * Apps are required to handle permissions on their own, this class only
+     * stores and manages the permissions of shares
+     * @see lib/public/constants.php
+     */
+
+    /**
+     * Register a sharing backend class that implements OCP\Share_Backend for an item type
+     * @param string $itemType Item type
+     * @param string $class Backend class
+     * @param string $collectionOf (optional) Depends on item type
+     * @param array $supportedFileExtensions (optional) List of supported file extensions if this item type depends on files
+     * @return boolean true if backend is registered or false if error
+     */
+    public static function registerBackend($itemType, $class, $collectionOf = null, $supportedFileExtensions = null) {
+        if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_enabled', 'yes') == 'yes') {
+            if (!isset(self::$backendTypes[$itemType])) {
+                self::$backendTypes[$itemType] = [
+                    'class' => $class,
+                    'collectionOf' => $collectionOf,
+                    'supportedFileExtensions' => $supportedFileExtensions
+                ];
+                return true;
+            }
+            \OCP\Util::writeLog('OCP\Share',
+                'Sharing backend '.$class.' not registered, '.self::$backendTypes[$itemType]['class']
+                .' is already registered for '.$itemType,
+                ILogger::WARN);
+        }
+        return false;
+    }
+
+    /**
+     * Get the items of item type shared with the current user
+     * @param string $itemType
+     * @param int $format (optional) Format type must be defined by the backend
+     * @param mixed $parameters (optional)
+     * @param int $limit Number of items to return (optional) Returns all by default
+     * @param boolean $includeCollections (optional)
+     * @return mixed Return depends on format
+     * @deprecated TESTS ONLY - this methods is only used by tests
+     * called like this:
+     * \OC\Share\Share::getItemsSharedWith('folder'); (apps/files_sharing/tests/UpdaterTest.php)
+     */
+    public static function getItemsSharedWith() {
+        return self::getItems('folder', null, self::$shareTypeUserAndGroups, \OC_User::getUser(), null, self::FORMAT_NONE,
+            null, -1, false);
+    }
+
+    /**
+     * Get the items of item type shared with a user
+     * @param string $itemType
+     * @param string $user id for which user we want the shares
+     * @param int $format (optional) Format type must be defined by the backend
+     * @param mixed $parameters (optional)
+     * @param int $limit Number of items to return (optional) Returns all by default
+     * @param boolean $includeCollections (optional)
+     * @return mixed Return depends on format
+     */
+    public static function getItemsSharedWithUser($itemType, $user, $format = self::FORMAT_NONE,
+                                                    $parameters = null, $limit = -1, $includeCollections = false) {
+        return self::getItems($itemType, null, self::$shareTypeUserAndGroups, $user, null, $format,
+            $parameters, $limit, $includeCollections);
+    }
+
+    /**
+     * Get the item of item type shared with a given user by source
+     * @param string $itemType
+     * @param string $itemSource
+     * @param string $user User to whom the item was shared
+     * @param string $owner Owner of the share
+     * @param int $shareType only look for a specific share type
+     * @return array Return list of items with file_target, permissions and expiration
+     */
+    public static function getItemSharedWithUser($itemType, $itemSource, $user, $owner = null, $shareType = null) {
+        $shares = [];
+        $fileDependent = false;
+
+        $where = 'WHERE';
+        $fileDependentWhere = '';
+        if ($itemType === 'file' || $itemType === 'folder') {
+            $fileDependent = true;
+            $column = 'file_source';
+            $fileDependentWhere = 'INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` ';
+            $fileDependentWhere .= 'INNER JOIN `*PREFIX*storages` ON `numeric_id` = `*PREFIX*filecache`.`storage` ';
+        } else {
+            $column = 'item_source';
+        }
+
+        $select = self::createSelectStatement(self::FORMAT_NONE, $fileDependent);
+
+        $where .= ' `' . $column . '` = ? AND `item_type` = ? ';
+        $arguments = [$itemSource, $itemType];
+        // for link shares $user === null
+        if ($user !== null) {
+            $where .= ' AND `share_with` = ? ';
+            $arguments[] = $user;
+        }
+
+        if ($shareType !== null) {
+            $where .= ' AND `share_type` = ? ';
+            $arguments[] = $shareType;
+        }
+
+        if ($owner !== null) {
+            $where .= ' AND `uid_owner` = ? ';
+            $arguments[] = $owner;
+        }
+
+        $query = \OC_DB::prepare('SELECT ' . $select . ' FROM `*PREFIX*share` '. $fileDependentWhere . $where);
+
+        $result = \OC_DB::executeAudited($query, $arguments);
+
+        while ($row = $result->fetchRow()) {
+            if ($fileDependent && !self::isFileReachable($row['path'], $row['storage_id'])) {
+                continue;
+            }
+            if ($fileDependent && (int)$row['file_parent'] === -1) {
+                // if it is a mount point we need to get the path from the mount manager
+                $mountManager = \OC\Files\Filesystem::getMountManager();
+                $mountPoint = $mountManager->findByStorageId($row['storage_id']);
+                if (!empty($mountPoint)) {
+                    $path = $mountPoint[0]->getMountPoint();
+                    $path = trim($path, '/');
+                    $path = substr($path, strlen($owner) + 1); //normalize path to 'files/foo.txt`
+                    $row['path'] = $path;
+                } else {
+                    \OC::$server->getLogger()->warning(
+                        'Could not resolve mount point for ' . $row['storage_id'],
+                        ['app' => 'OCP\Share']
+                    );
+                }
+            }
+            $shares[] = $row;
+        }
+
+        //if didn't found a result than let's look for a group share.
+        if (empty($shares) && $user !== null) {
+            $userObject = \OC::$server->getUserManager()->get($user);
+            $groups = [];
+            if ($userObject) {
+                $groups = \OC::$server->getGroupManager()->getUserGroupIds($userObject);
+            }
+
+            if (!empty($groups)) {
+                $where = $fileDependentWhere . ' WHERE `' . $column . '` = ? AND `item_type` = ? AND `share_with` in (?)';
+                $arguments = [$itemSource, $itemType, $groups];
+                $types = [null, null, IQueryBuilder::PARAM_STR_ARRAY];
+
+                if ($owner !== null) {
+                    $where .= ' AND `uid_owner` = ?';
+                    $arguments[] = $owner;
+                    $types[] = null;
+                }
+
+                // TODO: inject connection, hopefully one day in the future when this
+                // class isn't static anymore...
+                $conn = \OC::$server->getDatabaseConnection();
+                $result = $conn->executeQuery(
+                    'SELECT ' . $select . ' FROM `*PREFIX*share` ' . $where,
+                    $arguments,
+                    $types
+                );
+
+                while ($row = $result->fetch()) {
+                    $shares[] = $row;
+                }
+            }
+        }
+
+        return $shares;
+    }
+
+    /**
+     * Get the item of item type shared with the current user by source
+     * @param string $itemType
+     * @param string $itemSource
+     * @param int $format (optional) Format type must be defined by the backend
+     * @param mixed $parameters
+     * @param boolean $includeCollections
+     * @param string $shareWith (optional) define against which user should be checked, default: current user
+     * @return array
+     */
+    public static function getItemSharedWithBySource($itemType, $itemSource, $format = self::FORMAT_NONE,
+                                                        $parameters = null, $includeCollections = false, $shareWith = null) {
+        $shareWith = ($shareWith === null) ? \OC_User::getUser() : $shareWith;
+        return self::getItems($itemType, $itemSource, self::$shareTypeUserAndGroups, $shareWith, null, $format,
+            $parameters, 1, $includeCollections, true);
+    }
+
+    /**
+     * Get the shared item of item type owned by the current user
+     * @param string $itemType
+     * @param string $itemSource
+     * @param int $format (optional) Format type must be defined by the backend
+     * @param mixed $parameters
+     * @param boolean $includeCollections
+     * @return mixed Return depends on format
+     */
+    public static function getItemShared($itemType, $itemSource, $format = self::FORMAT_NONE,
+                                            $parameters = null, $includeCollections = false) {
+        return self::getItems($itemType, $itemSource, null, null, \OC_User::getUser(), $format,
+            $parameters, -1, $includeCollections);
+    }
+
+    /**
+     * Unshare an item from a user, group, or delete a private link
+     * @param string $itemType
+     * @param string $itemSource
+     * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_LINK
+     * @param string $shareWith User or group the item is being shared with
+     * @param string $owner owner of the share, if null the current user is used
+     * @return boolean true on success or false on failure
+     */
+    public static function unshare($itemType, $itemSource, $shareType, $shareWith, $owner = null) {
+
+        // check if it is a valid itemType
+        self::getBackend($itemType);
+
+        $items = self::getItemSharedWithUser($itemType, $itemSource, $shareWith, $owner, $shareType);
+
+        $toDelete = [];
+        $newParent = null;
+        $currentUser = $owner ? $owner : \OC_User::getUser();
+        foreach ($items as $item) {
+            // delete the item with the expected share_type and owner
+            if ((int)$item['share_type'] === (int)$shareType && $item['uid_owner'] === $currentUser) {
+                $toDelete = $item;
+            // if there is more then one result we don't have to delete the children
+                // but update their parent. For group shares the new parent should always be
+                // the original group share and not the db entry with the unique name
+            } elseif ((int)$item['share_type'] === self::$shareTypeGroupUserUnique) {
+                $newParent = $item['parent'];
+            } else {
+                $newParent = $item['id'];
+            }
+        }
+
+        if (!empty($toDelete)) {
+            self::unshareItem($toDelete, $newParent);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Checks whether a share has expired, calls unshareItem() if yes.
+     * @param array $item Share data (usually database row)
+     * @return boolean True if item was expired, false otherwise.
+     */
+    protected static function expireItem(array $item) {
+        $result = false;
+
+        // only use default expiration date for link shares
+        if ((int) $item['share_type'] === IShare::TYPE_LINK) {
+
+            // calculate expiration date
+            if (!empty($item['expiration'])) {
+                $userDefinedExpire = new \DateTime($item['expiration']);
+                $expires = $userDefinedExpire->getTimestamp();
+            } else {
+                $expires = null;
+            }
+
+
+            // get default expiration settings
+            $defaultSettings = Helper::getDefaultExpireSetting();
+            $expires = Helper::calculateExpireDate($defaultSettings, $item['stime'], $expires);
+
+
+            if (is_int($expires)) {
+                $now = time();
+                if ($now > $expires) {
+                    self::unshareItem($item);
+                    $result = true;
+                }
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * Unshares a share given a share data array
+     * @param array $item Share data (usually database row)
+     * @param int $newParent parent ID
+     * @return null
+     */
+    protected static function unshareItem(array $item, $newParent = null) {
+        $shareType = (int)$item['share_type'];
+        $shareWith = null;
+        if ($shareType !== IShare::TYPE_LINK) {
+            $shareWith = $item['share_with'];
+        }
+
+        // Pass all the vars we have for now, they may be useful
+        $hookParams = [
+            'id' => $item['id'],
+            'itemType' => $item['item_type'],
+            'itemSource' => $item['item_source'],
+            'shareType' => $shareType,
+            'shareWith' => $shareWith,
+            'itemParent' => $item['parent'],
+            'uidOwner' => $item['uid_owner'],
+        ];
+        if ($item['item_type'] === 'file' || $item['item_type'] === 'folder') {
+            $hookParams['fileSource'] = $item['file_source'];
+            $hookParams['fileTarget'] = $item['file_target'];
+        }
+
+        \OC_Hook::emit(\OCP\Share::class, 'pre_unshare', $hookParams);
+        $deletedShares = Helper::delete($item['id'], false, null, $newParent);
+        $deletedShares[] = $hookParams;
+        $hookParams['deletedShares'] = $deletedShares;
+        \OC_Hook::emit(\OCP\Share::class, 'post_unshare', $hookParams);
+        if ((int)$item['share_type'] === IShare::TYPE_REMOTE && \OC::$server->getUserSession()->getUser()) {
+            list(, $remote) = Helper::splitUserRemote($item['share_with']);
+            self::sendRemoteUnshare($remote, $item['id'], $item['token']);
+        }
+    }
+
+    /**
+     * Get the backend class for the specified item type
+     * @param string $itemType
+     * @throws \Exception
+     * @return \OCP\Share_Backend
+     */
+    public static function getBackend($itemType) {
+        $l = \OC::$server->getL10N('lib');
+        if (isset(self::$backends[$itemType])) {
+            return self::$backends[$itemType];
+        } elseif (isset(self::$backendTypes[$itemType]['class'])) {
+            $class = self::$backendTypes[$itemType]['class'];
+            if (class_exists($class)) {
+                self::$backends[$itemType] = new $class;
+                if (!(self::$backends[$itemType] instanceof \OCP\Share_Backend)) {
+                    $message = 'Sharing backend %s must implement the interface OCP\Share_Backend';
+                    $message_t = $l->t('Sharing backend %s must implement the interface OCP\Share_Backend', [$class]);
+                    \OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
+                    throw new \Exception($message_t);
+                }
+                return self::$backends[$itemType];
+            } else {
+                $message = 'Sharing backend %s not found';
+                $message_t = $l->t('Sharing backend %s not found', [$class]);
+                \OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
+                throw new \Exception($message_t);
+            }
+        }
+        $message = 'Sharing backend for %s not found';
+        $message_t = $l->t('Sharing backend for %s not found', [$itemType]);
+        \OCP\Util::writeLog('OCP\Share', sprintf($message, $itemType), ILogger::ERROR);
+        throw new \Exception($message_t);
+    }
+
+    /**
+     * Check if resharing is allowed
+     * @return boolean true if allowed or false
+     *
+     * Resharing is allowed by default if not configured
+     */
+    public static function isResharingAllowed() {
+        if (!isset(self::$isResharingAllowed)) {
+            if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_allow_resharing', 'yes') == 'yes') {
+                self::$isResharingAllowed = true;
+            } else {
+                self::$isResharingAllowed = false;
+            }
+        }
+        return self::$isResharingAllowed;
+    }
+
+    /**
+     * Get a list of collection item types for the specified item type
+     * @param string $itemType
+     * @return array
+     */
+    private static function getCollectionItemTypes($itemType) {
+        $collectionTypes = [$itemType];
+        foreach (self::$backendTypes as $type => $backend) {
+            if (in_array($backend['collectionOf'], $collectionTypes)) {
+                $collectionTypes[] = $type;
+            }
+        }
+        // TODO Add option for collections to be collection of themselves, only 'folder' does it now...
+        if (isset(self::$backendTypes[$itemType]) && (!self::getBackend($itemType) instanceof \OCP\Share_Backend_Collection || $itemType != 'folder')) {
+            unset($collectionTypes[0]);
+        }
+        // Return array if collections were found or the item type is a
+        // collection itself - collections can be inside collections
+        if (count($collectionTypes) > 0) {
+            return $collectionTypes;
+        }
+        return false;
+    }
+
+    /**
+     * Get shared items from the database
+     * @param string $itemType
+     * @param string $item Item source or target (optional)
+     * @param int $shareType SHARE_TYPE_USER, SHARE_TYPE_GROUP, SHARE_TYPE_LINK, $shareTypeUserAndGroups, or $shareTypeGroupUserUnique
+     * @param string $shareWith User or group the item is being shared with
+     * @param string $uidOwner User that is the owner of shared items (optional)
+     * @param int $format Format to convert items to with formatItems() (optional)
+     * @param mixed $parameters to pass to formatItems() (optional)
+     * @param int $limit Number of items to return, -1 to return all matches (optional)
+     * @param boolean $includeCollections Include collection item types (optional)
+     * @param boolean $itemShareWithBySource (optional)
+     * @param boolean $checkExpireDate
+     * @return array
+     *
+     * See public functions getItem(s)... for parameter usage
+     *
+     */
+    public static function getItems($itemType, $item = null, $shareType = null, $shareWith = null,
+                                    $uidOwner = null, $format = self::FORMAT_NONE, $parameters = null, $limit = -1,
+                                    $includeCollections = false, $itemShareWithBySource = false, $checkExpireDate = true) {
+        if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_enabled', 'yes') != 'yes') {
+            return [];
+        }
+        $backend = self::getBackend($itemType);
+        $collectionTypes = false;
+        // Get filesystem root to add it to the file target and remove from the
+        // file source, match file_source with the file cache
+        if ($itemType == 'file' || $itemType == 'folder') {
+            if (!is_null($uidOwner)) {
+                $root = \OC\Files\Filesystem::getRoot();
+            } else {
+                $root = '';
+            }
+            $where = 'INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` ';
+            if (!isset($item)) {
+                $where .= ' AND `file_target` IS NOT NULL ';
+            }
+            $where .= 'INNER JOIN `*PREFIX*storages` ON `numeric_id` = `*PREFIX*filecache`.`storage` ';
+            $fileDependent = true;
+            $queryArgs = [];
+        } else {
+            $fileDependent = false;
+            $root = '';
+            $collectionTypes = self::getCollectionItemTypes($itemType);
+            if ($includeCollections && !isset($item) && $collectionTypes) {
+                // If includeCollections is true, find collections of this item type, e.g. a music album contains songs
+                if (!in_array($itemType, $collectionTypes)) {
+                    $itemTypes = array_merge([$itemType], $collectionTypes);
+                } else {
+                    $itemTypes = $collectionTypes;
+                }
+                $placeholders = implode(',', array_fill(0, count($itemTypes), '?'));
+                $where = ' WHERE `item_type` IN ('.$placeholders.'))';
+                $queryArgs = $itemTypes;
+            } else {
+                $where = ' WHERE `item_type` = ?';
+                $queryArgs = [$itemType];
+            }
+        }
+        if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_allow_links', 'yes') !== 'yes') {
+            $where .= ' AND `share_type` != ?';
+            $queryArgs[] = IShare::TYPE_LINK;
+        }
+        if (isset($shareType)) {
+            // Include all user and group items
+            if ($shareType == self::$shareTypeUserAndGroups && isset($shareWith)) {
+                $where .= ' AND ((`share_type` in (?, ?) AND `share_with` = ?) ';
+                $queryArgs[] = IShare::TYPE_USER;
+                $queryArgs[] = self::$shareTypeGroupUserUnique;
+                $queryArgs[] = $shareWith;
+
+                $user = \OC::$server->getUserManager()->get($shareWith);
+                $groups = [];
+                if ($user) {
+                    $groups = \OC::$server->getGroupManager()->getUserGroupIds($user);
+                }
+                if (!empty($groups)) {
+                    $placeholders = implode(',', array_fill(0, count($groups), '?'));
+                    $where .= ' OR (`share_type` = ? AND `share_with` IN ('.$placeholders.')) ';
+                    $queryArgs[] = IShare::TYPE_GROUP;
+                    $queryArgs = array_merge($queryArgs, $groups);
+                }
+                $where .= ')';
+                // Don't include own group shares
+                $where .= ' AND `uid_owner` != ?';
+                $queryArgs[] = $shareWith;
+            } else {
+                $where .= ' AND `share_type` = ?';
+                $queryArgs[] = $shareType;
+                if (isset($shareWith)) {
+                    $where .= ' AND `share_with` = ?';
+                    $queryArgs[] = $shareWith;
+                }
+            }
+        }
+        if (isset($uidOwner)) {
+            $where .= ' AND `uid_owner` = ?';
+            $queryArgs[] = $uidOwner;
+            if (!isset($shareType)) {
+                // Prevent unique user targets for group shares from being selected
+                $where .= ' AND `share_type` != ?';
+                $queryArgs[] = self::$shareTypeGroupUserUnique;
+            }
+            if ($fileDependent) {
+                $column = 'file_source';
+            } else {
+                $column = 'item_source';
+            }
+        } else {
+            if ($fileDependent) {
+                $column = 'file_target';
+            } else {
+                $column = 'item_target';
+            }
+        }
+        if (isset($item)) {
+            $collectionTypes = self::getCollectionItemTypes($itemType);
+            if ($includeCollections && $collectionTypes && !in_array('folder', $collectionTypes)) {
+                $where .= ' AND (';
+            } else {
+                $where .= ' AND';
+            }
+            // If looking for own shared items, check item_source else check item_target
+            if (isset($uidOwner) || $itemShareWithBySource) {
+                // If item type is a file, file source needs to be checked in case the item was converted
+                if ($fileDependent) {
+                    $where .= ' `file_source` = ?';
+                    $column = 'file_source';
+                } else {
+                    $where .= ' `item_source` = ?';
+                    $column = 'item_source';
+                }
+            } else {
+                if ($fileDependent) {
+                    $where .= ' `file_target` = ?';
+                    $item = \OC\Files\Filesystem::normalizePath($item);
+                } else {
+                    $where .= ' `item_target` = ?';
+                }
+            }
+            $queryArgs[] = $item;
+            if ($includeCollections && $collectionTypes && !in_array('folder', $collectionTypes)) {
+                $placeholders = implode(',', array_fill(0, count($collectionTypes), '?'));
+                $where .= ' OR `item_type` IN ('.$placeholders.'))';
+                $queryArgs = array_merge($queryArgs, $collectionTypes);
+            }
+        }
+
+        if ($shareType == self::$shareTypeUserAndGroups && $limit === 1) {
+            // Make sure the unique user target is returned if it exists,
+            // unique targets should follow the group share in the database
+            // If the limit is not 1, the filtering can be done later
+            $where .= ' ORDER BY `*PREFIX*share`.`id` DESC';
+        } else {
+            $where .= ' ORDER BY `*PREFIX*share`.`id` ASC';
+        }
+
+        if ($limit != -1 && !$includeCollections) {
+            // The limit must be at least 3, because filtering needs to be done
+            if ($limit < 3) {
+                $queryLimit = 3;
+            } else {
+                $queryLimit = $limit;
+            }
+        } else {
+            $queryLimit = null;
+        }
+        $select = self::createSelectStatement($format, $fileDependent, $uidOwner);
+        $root = strlen($root);
+        $query = \OC_DB::prepare('SELECT '.$select.' FROM `*PREFIX*share` '.$where, $queryLimit);
+        $result = $query->execute($queryArgs);
+        if ($result === false) {
+            \OCP\Util::writeLog('OCP\Share',
+                \OC_DB::getErrorMessage() . ', select=' . $select . ' where=',
+                ILogger::ERROR);
+        }
+        $items = [];
+        $targets = [];
+        $switchedItems = [];
+        $mounts = [];
+        while ($row = $result->fetchRow()) {
+            self::transformDBResults($row);
+            // Filter out duplicate group shares for users with unique targets
+            if ($fileDependent && !self::isFileReachable($row['path'], $row['storage_id'])) {
+                continue;
+            }
+            if ($row['share_type'] == self::$shareTypeGroupUserUnique && isset($items[$row['parent']])) {
+                $row['share_type'] = IShare::TYPE_GROUP;
+                $row['unique_name'] = true; // remember that we use a unique name for this user
+                $row['share_with'] = $items[$row['parent']]['share_with'];
+                // if the group share was unshared from the user we keep the permission, otherwise
+                // we take the permission from the parent because this is always the up-to-date
+                // permission for the group share
+                if ($row['permissions'] > 0) {
+                    $row['permissions'] = $items[$row['parent']]['permissions'];
+                }
+                // Remove the parent group share
+                unset($items[$row['parent']]);
+                if ($row['permissions'] == 0) {
+                    continue;
+                }
+            } elseif (!isset($uidOwner)) {
+                // Check if the same target already exists
+                if (isset($targets[$row['id']])) {
+                    // Check if the same owner shared with the user twice
+                    // through a group and user share - this is allowed
+                    $id = $targets[$row['id']];
+                    if (isset($items[$id]) && $items[$id]['uid_owner'] == $row['uid_owner']) {
+                        // Switch to group share type to ensure resharing conditions aren't bypassed
+                        if ($items[$id]['share_type'] != IShare::TYPE_GROUP) {
+                            $items[$id]['share_type'] = IShare::TYPE_GROUP;
+                            $items[$id]['share_with'] = $row['share_with'];
+                        }
+                        // Switch ids if sharing permission is granted on only
+                        // one share to ensure correct parent is used if resharing
+                        if (~(int)$items[$id]['permissions'] & \OCP\Constants::PERMISSION_SHARE
+                            && (int)$row['permissions'] & \OCP\Constants::PERMISSION_SHARE) {
+                            $items[$row['id']] = $items[$id];
+                            $switchedItems[$id] = $row['id'];
+                            unset($items[$id]);
+                            $id = $row['id'];
+                        }
+                        $items[$id]['permissions'] |= (int)$row['permissions'];
+                    }
+                    continue;
+                } elseif (!empty($row['parent'])) {
+                    $targets[$row['parent']] = $row['id'];
+                }
+            }
+            // Remove root from file source paths if retrieving own shared items
+            if (isset($uidOwner) && isset($row['path'])) {
+                if (isset($row['parent'])) {
+                    $query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+                    $query->select('file_target')
+                        ->from('share')
+                        ->where($query->expr()->eq('id', $query->createNamedParameter($row['parent'])));
+
+                    $result = $query->execute();
+                    $parentRow = $result->fetch();
+                    $result->closeCursor();
+
+                    if ($parentRow === false) {
+                        \OCP\Util::writeLog('OCP\Share', 'Can\'t select parent: ' .
+                            \OC_DB::getErrorMessage() . ', select=' . $select . ' where=' . $where,
+                            ILogger::ERROR);
+                    } else {
+                        $tmpPath = $parentRow['file_target'];
+                        // find the right position where the row path continues from the target path
+                        $pos = strrpos($row['path'], $parentRow['file_target']);
+                        $subPath = substr($row['path'], $pos);
+                        $splitPath = explode('/', $subPath);
+                        foreach (array_slice($splitPath, 2) as $pathPart) {
+                            $tmpPath = $tmpPath . '/' . $pathPart;
+                        }
+                        $row['path'] = $tmpPath;
+                    }
+                } else {
+                    if (!isset($mounts[$row['storage']])) {
+                        $mountPoints = \OC\Files\Filesystem::getMountByNumericId($row['storage']);
+                        if (is_array($mountPoints) && !empty($mountPoints)) {
+                            $mounts[$row['storage']] = current($mountPoints);
+                        }
+                    }
+                    if (!empty($mounts[$row['storage']])) {
+                        $path = $mounts[$row['storage']]->getMountPoint().$row['path'];
+                        $relPath = substr($path, $root); // path relative to data/user
+                        $row['path'] = rtrim($relPath, '/');
+                    }
+                }
+            }
+
+            if ($checkExpireDate) {
+                if (self::expireItem($row)) {
+                    continue;
+                }
+            }
+            // Check if resharing is allowed, if not remove share permission
+            if (isset($row['permissions']) && (!self::isResharingAllowed() | \OCP\Util::isSharingDisabledForUser())) {
+                $row['permissions'] &= ~\OCP\Constants::PERMISSION_SHARE;
+            }
+            // Add display names to result
+            $row['share_with_displayname'] = $row['share_with'];
+            if (isset($row['share_with']) && $row['share_with'] != '' &&
+                $row['share_type'] === IShare::TYPE_USER) {
+                $shareWithUser = \OC::$server->getUserManager()->get($row['share_with']);
+                $row['share_with_displayname'] = $shareWithUser === null ? $row['share_with'] : $shareWithUser->getDisplayName();
+            } elseif (isset($row['share_with']) && $row['share_with'] != '' &&
+                $row['share_type'] === IShare::TYPE_REMOTE) {
+                $addressBookEntries = \OC::$server->getContactsManager()->search($row['share_with'], ['CLOUD']);
+                foreach ($addressBookEntries as $entry) {
+                    foreach ($entry['CLOUD'] as $cloudID) {
+                        if ($cloudID === $row['share_with']) {
+                            $row['share_with_displayname'] = $entry['FN'];
+                        }
+                    }
+                }
+            }
+            if (isset($row['uid_owner']) && $row['uid_owner'] != '') {
+                $ownerUser = \OC::$server->getUserManager()->get($row['uid_owner']);
+                $row['displayname_owner'] = $ownerUser === null ? $row['uid_owner'] : $ownerUser->getDisplayName();
+            }
+
+            if ($row['permissions'] > 0) {
+                $items[$row['id']] = $row;
+            }
+        }
+
+        // group items if we are looking for items shared with the current user
+        if (isset($shareWith) && $shareWith === \OCP\User::getUser()) {
+            $items = self::groupItems($items, $itemType);
+        }
+
+        if (!empty($items)) {
+            $collectionItems = [];
+            foreach ($items as &$row) {
+                // Return only the item instead of a 2-dimensional array
+                if ($limit == 1 && $row[$column] == $item && ($row['item_type'] == $itemType || $itemType == 'file')) {
+                    if ($format == self::FORMAT_NONE) {
+                        return $row;
+                    } else {
+                        break;
+                    }
+                }
+                // Check if this is a collection of the requested item type
+                if ($includeCollections && $collectionTypes && $row['item_type'] !== 'folder' && in_array($row['item_type'], $collectionTypes)) {
+                    if (($collectionBackend = self::getBackend($row['item_type']))
+                        && $collectionBackend instanceof \OCP\Share_Backend_Collection) {
+                        // Collections can be inside collections, check if the item is a collection
+                        if (isset($item) && $row['item_type'] == $itemType && $row[$column] == $item) {
+                            $collectionItems[] = $row;
+                        } else {
+                            $collection = [];
+                            $collection['item_type'] = $row['item_type'];
+                            if ($row['item_type'] == 'file' || $row['item_type'] == 'folder') {
+                                $collection['path'] = basename($row['path']);
+                            }
+                            $row['collection'] = $collection;
+                            // Fetch all of the children sources
+                            $children = $collectionBackend->getChildren($row[$column]);
+                            foreach ($children as $child) {
+                                $childItem = $row;
+                                $childItem['item_type'] = $itemType;
+                                if ($row['item_type'] != 'file' && $row['item_type'] != 'folder') {
+                                    $childItem['item_source'] = $child['source'];
+                                    $childItem['item_target'] = $child['target'];
+                                }
+                                if ($backend instanceof \OCP\Share_Backend_File_Dependent) {
+                                    if ($row['item_type'] == 'file' || $row['item_type'] == 'folder') {
+                                        $childItem['file_source'] = $child['source'];
+                                    } else { // TODO is this really needed if we already know that we use the file backend?
+                                        $meta = \OC\Files\Filesystem::getFileInfo($child['file_path']);
+                                        $childItem['file_source'] = $meta['fileid'];
+                                    }
+                                    $childItem['file_target'] =
+                                        \OC\Files\Filesystem::normalizePath($child['file_path']);
+                                }
+                                if (isset($item)) {
+                                    if ($childItem[$column] == $item) {
+                                        // Return only the item instead of a 2-dimensional array
+                                        if ($limit == 1) {
+                                            if ($format == self::FORMAT_NONE) {
+                                                return $childItem;
+                                            } else {
+                                                // Unset the items array and break out of both loops
+                                                $items = [];
+                                                $items[] = $childItem;
+                                                break 2;
+                                            }
+                                        } else {
+                                            $collectionItems[] = $childItem;
+                                        }
+                                    }
+                                } else {
+                                    $collectionItems[] = $childItem;
+                                }
+                            }
+                        }
+                    }
+                    // Remove collection item
+                    $toRemove = $row['id'];
+                    if (array_key_exists($toRemove, $switchedItems)) {
+                        $toRemove = $switchedItems[$toRemove];
+                    }
+                    unset($items[$toRemove]);
+                } elseif ($includeCollections && $collectionTypes && in_array($row['item_type'], $collectionTypes)) {
+                    // FIXME: Thats a dirty hack to improve file sharing performance,
+                    // see github issue #10588 for more details
+                    // Need to find a solution which works for all back-ends
+                    $collectionBackend = self::getBackend($row['item_type']);
+                    $sharedParents = $collectionBackend->getParents($row['item_source']);
+                    foreach ($sharedParents as $parent) {
+                        $collectionItems[] = $parent;
+                    }
+                }
+            }
+            if (!empty($collectionItems)) {
+                $collectionItems = array_unique($collectionItems, SORT_REGULAR);
+                $items = array_merge($items, $collectionItems);
+            }
+
+            // filter out invalid items, these can appear when subshare entries exist
+            // for a group in which the requested user isn't a member any more
+            $items = array_filter($items, function ($item) {
+                return $item['share_type'] !== self::$shareTypeGroupUserUnique;
+            });
+
+            return self::formatResult($items, $column, $backend, $format, $parameters);
+        } elseif ($includeCollections && $collectionTypes && in_array('folder', $collectionTypes)) {
+            // FIXME: Thats a dirty hack to improve file sharing performance,
+            // see github issue #10588 for more details
+            // Need to find a solution which works for all back-ends
+            $collectionItems = [];
+            $collectionBackend = self::getBackend('folder');
+            $sharedParents = $collectionBackend->getParents($item, $shareWith, $uidOwner);
+            foreach ($sharedParents as $parent) {
+                $collectionItems[] = $parent;
+            }
+            if ($limit === 1) {
+                return reset($collectionItems);
+            }
+            return self::formatResult($collectionItems, $column, $backend, $format, $parameters);
+        }
+
+        return [];
+    }
+
+    /**
+     * group items with link to the same source
+     *
+     * @param array $items
+     * @param string $itemType
+     * @return array of grouped items
+     */
+    protected static function groupItems($items, $itemType) {
+        $fileSharing = $itemType === 'file' || $itemType === 'folder';
+
+        $result = [];
+
+        foreach ($items as $item) {
+            $grouped = false;
+            foreach ($result as $key => $r) {
+                // for file/folder shares we need to compare file_source, otherwise we compare item_source
+                // only group shares if they already point to the same target, otherwise the file where shared
+                // before grouping of shares was added. In this case we don't group them toi avoid confusions
+                if (($fileSharing && $item['file_source'] === $r['file_source'] && $item['file_target'] === $r['file_target']) ||
+                    (!$fileSharing && $item['item_source'] === $r['item_source'] && $item['item_target'] === $r['item_target'])) {
+                    // add the first item to the list of grouped shares
+                    if (!isset($result[$key]['grouped'])) {
+                        $result[$key]['grouped'][] = $result[$key];
+                    }
+                    $result[$key]['permissions'] = (int) $item['permissions'] | (int) $r['permissions'];
+                    $result[$key]['grouped'][] = $item;
+                    $grouped = true;
+                    break;
+                }
+            }
+
+            if (!$grouped) {
+                $result[] = $item;
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * construct select statement
+     * @param int $format
+     * @param boolean $fileDependent ist it a file/folder share or a generla share
+     * @param string $uidOwner
+     * @return string select statement
+     */
+    private static function createSelectStatement($format, $fileDependent, $uidOwner = null) {
+        $select = '*';
+        if ($format == self::FORMAT_STATUSES) {
+            if ($fileDependent) {
+                $select = '`*PREFIX*share`.`id`, `*PREFIX*share`.`parent`, `share_type`, `path`, `storage`, '
+                    . '`share_with`, `uid_owner` , `file_source`, `stime`, `*PREFIX*share`.`permissions`, '
+                    . '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`, '
+                    . '`uid_initiator`';
+            } else {
+                $select = '`id`, `parent`, `share_type`, `share_with`, `uid_owner`, `item_source`, `stime`, `*PREFIX*share`.`permissions`';
+            }
+        } else {
+            if (isset($uidOwner)) {
+                if ($fileDependent) {
+                    $select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `*PREFIX*share`.`parent`,'
+                        . ' `share_type`, `share_with`, `file_source`, `file_target`, `path`, `*PREFIX*share`.`permissions`, `stime`,'
+                        . ' `expiration`, `token`, `storage`, `mail_send`, `uid_owner`, '
+                        . '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`';
+                } else {
+                    $select = '`id`, `item_type`, `item_source`, `parent`, `share_type`, `share_with`, `*PREFIX*share`.`permissions`,'
+                        . ' `stime`, `file_source`, `expiration`, `token`, `mail_send`, `uid_owner`';
+                }
+            } else {
+                if ($fileDependent) {
+                    if ($format == \OCA\Files_Sharing\ShareBackend\File::FORMAT_GET_FOLDER_CONTENTS || $format == \OCA\Files_Sharing\ShareBackend\File::FORMAT_FILE_APP_ROOT) {
+                        $select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `*PREFIX*share`.`parent`, `uid_owner`, '
+                            . '`share_type`, `share_with`, `file_source`, `path`, `file_target`, `stime`, '
+                            . '`*PREFIX*share`.`permissions`, `expiration`, `storage`, `*PREFIX*filecache`.`parent` as `file_parent`, '
+                            . '`name`, `mtime`, `mimetype`, `mimepart`, `size`, `encrypted`, `etag`, `mail_send`';
+                    } else {
+                        $select = '`*PREFIX*share`.`id`, `item_type`, `item_source`, `item_target`,'
+                            . '`*PREFIX*share`.`parent`, `share_type`, `share_with`, `uid_owner`,'
+                            . '`file_source`, `path`, `file_target`, `*PREFIX*share`.`permissions`,'
+                            . '`stime`, `expiration`, `token`, `storage`, `mail_send`,'
+                            . '`*PREFIX*storages`.`id` AS `storage_id`, `*PREFIX*filecache`.`parent` as `file_parent`';
+                    }
+                }
+            }
+        }
+        return $select;
+    }
+
+
+    /**
+     * transform db results
+     * @param array $row result
+     */
+    private static function transformDBResults(&$row) {
+        if (isset($row['id'])) {
+            $row['id'] = (int) $row['id'];
+        }
+        if (isset($row['share_type'])) {
+            $row['share_type'] = (int) $row['share_type'];
+        }
+        if (isset($row['parent'])) {
+            $row['parent'] = (int) $row['parent'];
+        }
+        if (isset($row['file_parent'])) {
+            $row['file_parent'] = (int) $row['file_parent'];
+        }
+        if (isset($row['file_source'])) {
+            $row['file_source'] = (int) $row['file_source'];
+        }
+        if (isset($row['permissions'])) {
+            $row['permissions'] = (int) $row['permissions'];
+        }
+        if (isset($row['storage'])) {
+            $row['storage'] = (int) $row['storage'];
+        }
+        if (isset($row['stime'])) {
+            $row['stime'] = (int) $row['stime'];
+        }
+        if (isset($row['expiration']) && $row['share_type'] !== IShare::TYPE_LINK) {
+            // discard expiration date for non-link shares, which might have been
+            // set by ancient bugs
+            $row['expiration'] = null;
+        }
+    }
+
+    /**
+     * format result
+     * @param array $items result
+     * @param string $column is it a file share or a general share ('file_target' or 'item_target')
+     * @param \OCP\Share_Backend $backend sharing backend
+     * @param int $format
+     * @param array $parameters additional format parameters
+     * @return array format result
+     */
+    private static function formatResult($items, $column, $backend, $format = self::FORMAT_NONE , $parameters = null) {
+        if ($format === self::FORMAT_NONE) {
+            return $items;
+        } elseif ($format === self::FORMAT_STATUSES) {
+            $statuses = [];
+            foreach ($items as $item) {
+                if ($item['share_type'] === IShare::TYPE_LINK) {
+                    if ($item['uid_initiator'] !== \OC::$server->getUserSession()->getUser()->getUID()) {
+                        continue;
+                    }
+                    $statuses[$item[$column]]['link'] = true;
+                } elseif (!isset($statuses[$item[$column]])) {
+                    $statuses[$item[$column]]['link'] = false;
+                }
+                if (!empty($item['file_target'])) {
+                    $statuses[$item[$column]]['path'] = $item['path'];
+                }
+            }
+            return $statuses;
+        } else {
+            return $backend->formatItems($items, $format, $parameters);
+        }
+    }
+
+    /**
+     * remove protocol from URL
+     *
+     * @param string $url
+     * @return string
+     */
+    public static function removeProtocolFromUrl($url) {
+        if (strpos($url, 'https://') === 0) {
+            return substr($url, strlen('https://'));
+        } elseif (strpos($url, 'http://') === 0) {
+            return substr($url, strlen('http://'));
+        }
+
+        return $url;
+    }
+
+    /**
+     * try http post first with https and then with http as a fallback
+     *
+     * @param string $remoteDomain
+     * @param string $urlSuffix
+     * @param array $fields post parameters
+     * @return array
+     */
+    private static function tryHttpPostToShareEndpoint($remoteDomain, $urlSuffix, array $fields) {
+        $protocol = 'https://';
+        $result = [
+            'success' => false,
+            'result' => '',
+        ];
+        $try = 0;
+        $discoveryService = \OC::$server->query(\OCP\OCS\IDiscoveryService::class);
+        while ($result['success'] === false && $try < 2) {
+            $federationEndpoints = $discoveryService->discover($protocol . $remoteDomain, 'FEDERATED_SHARING');
+            $endpoint = isset($federationEndpoints['share']) ? $federationEndpoints['share'] : '/ocs/v2.php/cloud/shares';
+            $client = \OC::$server->getHTTPClientService()->newClient();
+
+            try {
+                $response = $client->post(
+                    $protocol . $remoteDomain . $endpoint . $urlSuffix . '?format=' . self::RESPONSE_FORMAT,
+                    [
+                        'body' => $fields,
+                        'connect_timeout' => 10,
+                    ]
+                );
+
+                $result = ['success' => true, 'result' => $response->getBody()];
+            } catch (\Exception $e) {
+                $result = ['success' => false, 'result' => $e->getMessage()];
+            }
+
+            $try++;
+            $protocol = 'http://';
+        }
+
+        return $result;
+    }
+
+    /**
+     * send server-to-server unshare to remote server
+     *
+     * @param string $remote url
+     * @param int $id share id
+     * @param string $token
+     * @return bool
+     */
+    private static function sendRemoteUnshare($remote, $id, $token) {
+        $url = rtrim($remote, '/');
+        $fields = ['token' => $token, 'format' => 'json'];
+        $url = self::removeProtocolFromUrl($url);
+        $result = self::tryHttpPostToShareEndpoint($url, '/'.$id.'/unshare', $fields);
+        $status = json_decode($result['result'], true);
+
+        return ($result['success'] && ($status['ocs']['meta']['statuscode'] === 100 || $status['ocs']['meta']['statuscode'] === 200));
+    }
+
+    /**
+     * @return int
+     */
+    public static function getExpireInterval() {
+        return (int)\OC::$server->getConfig()->getAppValue('core', 'shareapi_expire_after_n_days', '7');
+    }
+
+    /**
+     * Checks whether the given path is reachable for the given owner
+     *
+     * @param string $path path relative to files
+     * @param string $ownerStorageId storage id of the owner
+     *
+     * @return boolean true if file is reachable, false otherwise
+     */
+    private static function isFileReachable($path, $ownerStorageId) {
+        // if outside the home storage, file is always considered reachable
+        if (!(substr($ownerStorageId, 0, 6) === 'home::' ||
+            substr($ownerStorageId, 0, 13) === 'object::user:'
+        )) {
+            return true;
+        }
+
+        // if inside the home storage, the file has to be under "/files/"
+        $path = ltrim($path, '/');
+        if (substr($path, 0, 6) === 'files/') {
+            return true;
+        }
+
+        return false;
+    }
 }

Spacing +22 added lines, -22 removed lines

@@ -150,7 +150,7 @@ 
 
 		$select = self::createSelectStatement(self::FORMAT_NONE, $fileDependent);
 
-		$where .= ' `' . $column . '` = ? AND `item_type` = ? ';
+		$where .= ' `'.$column.'` = ? AND `item_type` = ? ';
 		$arguments = [$itemSource, $itemType];
 		// for link shares $user === null
 		if ($user !== null) {
@@ -168,7 +168,7 @@ 
 			$arguments[] = $owner;
 		}
 
-		$query = \OC_DB::prepare('SELECT ' . $select . ' FROM `*PREFIX*share` '. $fileDependentWhere . $where);
+		$query = \OC_DB::prepare('SELECT '.$select.' FROM `*PREFIX*share` '.$fileDependentWhere.$where);
 
 		$result = \OC_DB::executeAudited($query, $arguments);
 
@@ -176,7 +176,7 @@ 
 			if ($fileDependent && !self::isFileReachable($row['path'], $row['storage_id'])) {
 				continue;
 			}
-			if ($fileDependent && (int)$row['file_parent'] === -1) {
+			if ($fileDependent && (int) $row['file_parent'] === -1) {
 				// if it is a mount point we need to get the path from the mount manager
 				$mountManager = \OC\Files\Filesystem::getMountManager();
 				$mountPoint = $mountManager->findByStorageId($row['storage_id']);
@@ -187,7 +187,7 @@ 
 					$row['path'] = $path;
 				} else {
 					\OC::$server->getLogger()->warning(
-						'Could not resolve mount point for ' . $row['storage_id'],
+						'Could not resolve mount point for '.$row['storage_id'],
 						['app' => 'OCP\Share']
 					);
 				}
@@ -204,7 +204,7 @@ 
 			}
 
 			if (!empty($groups)) {
-				$where = $fileDependentWhere . ' WHERE `' . $column . '` = ? AND `item_type` = ? AND `share_with` in (?)';
+				$where = $fileDependentWhere.' WHERE `'.$column.'` = ? AND `item_type` = ? AND `share_with` in (?)';
 				$arguments = [$itemSource, $itemType, $groups];
 				$types = [null, null, IQueryBuilder::PARAM_STR_ARRAY];
 
@@ -218,7 +218,7 @@ 
 				// class isn't static anymore...
 				$conn = \OC::$server->getDatabaseConnection();
 				$result = $conn->executeQuery(
-					'SELECT ' . $select . ' FROM `*PREFIX*share` ' . $where,
+					'SELECT '.$select.' FROM `*PREFIX*share` '.$where,
 					$arguments,
 					$types
 				);
@@ -285,12 +285,12 @@ 
 		$currentUser = $owner ? $owner : \OC_User::getUser();
 		foreach ($items as $item) {
 			// delete the item with the expected share_type and owner
-			if ((int)$item['share_type'] === (int)$shareType && $item['uid_owner'] === $currentUser) {
+			if ((int) $item['share_type'] === (int) $shareType && $item['uid_owner'] === $currentUser) {
 				$toDelete = $item;
 			// if there is more then one result we don't have to delete the children
 				// but update their parent. For group shares the new parent should always be
 				// the original group share and not the db entry with the unique name
-			} elseif ((int)$item['share_type'] === self::$shareTypeGroupUserUnique) {
+			} elseif ((int) $item['share_type'] === self::$shareTypeGroupUserUnique) {
 				$newParent = $item['parent'];
 			} else {
 				$newParent = $item['id'];
@@ -347,7 +347,7 @@ 
 	 * @return null
 	 */
 	protected static function unshareItem(array $item, $newParent = null) {
-		$shareType = (int)$item['share_type'];
+		$shareType = (int) $item['share_type'];
 		$shareWith = null;
 		if ($shareType !== IShare::TYPE_LINK) {
 			$shareWith = $item['share_with'];
@@ -373,7 +373,7 @@ 
 		$deletedShares[] = $hookParams;
 		$hookParams['deletedShares'] = $deletedShares;
 		\OC_Hook::emit(\OCP\Share::class, 'post_unshare', $hookParams);
-		if ((int)$item['share_type'] === IShare::TYPE_REMOTE && \OC::$server->getUserSession()->getUser()) {
+		if ((int) $item['share_type'] === IShare::TYPE_REMOTE && \OC::$server->getUserSession()->getUser()) {
 			list(, $remote) = Helper::splitUserRemote($item['share_with']);
 			self::sendRemoteUnshare($remote, $item['id'], $item['token']);
 		}
@@ -628,7 +628,7 @@ 
 		$result = $query->execute($queryArgs);
 		if ($result === false) {
 			\OCP\Util::writeLog('OCP\Share',
-				\OC_DB::getErrorMessage() . ', select=' . $select . ' where=',
+				\OC_DB::getErrorMessage().', select='.$select.' where=',
 				ILogger::ERROR);
 		}
 		$items = [];
@@ -670,14 +670,14 @@ 
 						}
 						// Switch ids if sharing permission is granted on only
 						// one share to ensure correct parent is used if resharing
-						if (~(int)$items[$id]['permissions'] & \OCP\Constants::PERMISSION_SHARE
-							&& (int)$row['permissions'] & \OCP\Constants::PERMISSION_SHARE) {
+						if (~(int) $items[$id]['permissions'] & \OCP\Constants::PERMISSION_SHARE
+							&& (int) $row['permissions'] & \OCP\Constants::PERMISSION_SHARE) {
 							$items[$row['id']] = $items[$id];
 							$switchedItems[$id] = $row['id'];
 							unset($items[$id]);
 							$id = $row['id'];
 						}
-						$items[$id]['permissions'] |= (int)$row['permissions'];
+						$items[$id]['permissions'] |= (int) $row['permissions'];
 					}
 					continue;
 				} elseif (!empty($row['parent'])) {
@@ -697,8 +697,8 @@ 
 					$result->closeCursor();
 
 					if ($parentRow === false) {
-						\OCP\Util::writeLog('OCP\Share', 'Can\'t select parent: ' .
-							\OC_DB::getErrorMessage() . ', select=' . $select . ' where=' . $where,
+						\OCP\Util::writeLog('OCP\Share', 'Can\'t select parent: '.
+							\OC_DB::getErrorMessage().', select='.$select.' where='.$where,
 							ILogger::ERROR);
 					} else {
 						$tmpPath = $parentRow['file_target'];
@@ -707,7 +707,7 @@ 
 						$subPath = substr($row['path'], $pos);
 						$splitPath = explode('/', $subPath);
 						foreach (array_slice($splitPath, 2) as $pathPart) {
-							$tmpPath = $tmpPath . '/' . $pathPart;
+							$tmpPath = $tmpPath.'/'.$pathPart;
 						}
 						$row['path'] = $tmpPath;
 					}
@@ -857,7 +857,7 @@ 
 
 			// filter out invalid items, these can appear when subshare entries exist
 			// for a group in which the requested user isn't a member any more
-			$items = array_filter($items, function ($item) {
+			$items = array_filter($items, function($item) {
 				return $item['share_type'] !== self::$shareTypeGroupUserUnique;
 			});
 
@@ -1015,7 +1015,7 @@ 
 	 * @param array $parameters additional format parameters
 	 * @return array format result
 	 */
-	private static function formatResult($items, $column, $backend, $format = self::FORMAT_NONE , $parameters = null) {
+	private static function formatResult($items, $column, $backend, $format = self::FORMAT_NONE, $parameters = null) {
 		if ($format === self::FORMAT_NONE) {
 			return $items;
 		} elseif ($format === self::FORMAT_STATUSES) {
@@ -1072,13 +1072,13 @@ 
 		$try = 0;
 		$discoveryService = \OC::$server->query(\OCP\OCS\IDiscoveryService::class);
 		while ($result['success'] === false && $try < 2) {
-			$federationEndpoints = $discoveryService->discover($protocol . $remoteDomain, 'FEDERATED_SHARING');
+			$federationEndpoints = $discoveryService->discover($protocol.$remoteDomain, 'FEDERATED_SHARING');
 			$endpoint = isset($federationEndpoints['share']) ? $federationEndpoints['share'] : '/ocs/v2.php/cloud/shares';
 			$client = \OC::$server->getHTTPClientService()->newClient();
 
 			try {
 				$response = $client->post(
-					$protocol . $remoteDomain . $endpoint . $urlSuffix . '?format=' . self::RESPONSE_FORMAT,
+					$protocol.$remoteDomain.$endpoint.$urlSuffix.'?format='.self::RESPONSE_FORMAT,
 					[
 						'body' => $fields,
 						'connect_timeout' => 10,
@@ -1119,7 +1119,7 @@ 
 	 * @return int
 	 */
 	public static function getExpireInterval() {
-		return (int)\OC::$server->getConfig()->getAppValue('core', 'shareapi_expire_after_n_days', '7');
+		return (int) \OC::$server->getConfig()->getAppValue('core', 'shareapi_expire_after_n_days', '7');
 	}
 
 	/**