From cc31c3827749e2eeb3437648226413742ffe7dcd Mon Sep 17 00:00:00 2001
From: Arthur Schiwon <blizzz@arthur-schiwon.de>
Date: Thu, 12 Mar 2020 12:45:52 +0100
Subject: [PATCH] don't circulate with only one backend

- saves some overhead costs
- in some occasions saves LDAP requests

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>
---
 apps/user_ldap/lib/Group_Proxy.php |  8 +++++++-
 apps/user_ldap/lib/Proxy.php       | 17 +++++++++++++++--
 apps/user_ldap/lib/User_Proxy.php  |  8 +++++++-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/apps/user_ldap/lib/Group_Proxy.php b/apps/user_ldap/lib/Group_Proxy.php
index 3bd0cc4c40..a586906df8 100644
--- a/apps/user_ldap/lib/Group_Proxy.php
+++ b/apps/user_ldap/lib/Group_Proxy.php
@@ -60,7 +60,9 @@ class Group_Proxy extends Proxy implements \OCP\GroupInterface, IGroupLDAP, IGet
 		$cacheKey = $this->getGroupCacheKey($gid);
 		foreach ($this->backends as $configPrefix => $backend) {
 			if ($result = call_user_func_array([$backend, $method], $parameters)) {
-				$this->writeToCache($cacheKey, $configPrefix);
+				if(!$this->isSingleBackend()) {
+					$this->writeToCache($cacheKey, $configPrefix);
+				}
 				return $result;
 			}
 		}
@@ -99,6 +101,10 @@ class Group_Proxy extends Proxy implements \OCP\GroupInterface, IGroupLDAP, IGet
 		return false;
 	}
 
+	protected function activeBackends(): int {
+		return count($this->backends);
+	}
+
 	/**
 	 * is user in group?
 	 * @param string $uid uid of the user
diff --git a/apps/user_ldap/lib/Proxy.php b/apps/user_ldap/lib/Proxy.php
index 3cf55f8cd5..09f4ac407d 100644
--- a/apps/user_ldap/lib/Proxy.php
+++ b/apps/user_ldap/lib/Proxy.php
@@ -40,6 +40,8 @@ use OCA\User_LDAP\User\Manager;
 abstract class Proxy {
 	private static $accesses = [];
 	private $ldap = null;
+	/** @var bool  */
+	private $isSingleBackend;
 
 	/** @var \OCP\ICache|null */
 	private $cache;
@@ -139,6 +141,15 @@ abstract class Proxy {
 	 */
 	abstract public function getLDAPAccess($id);
 
+	abstract protected function activeBackends(): int;
+
+	protected function isSingleBackend(): bool{
+		if($this->isSingleBackend === null) {
+			$this->isSingleBackend = $this->activeBackends() === 1;
+		}
+		return $this->isSingleBackend;
+	}
+
 	/**
 	 * Takes care of the request to the User backend
 	 * @param string $id
@@ -148,8 +159,10 @@ abstract class Proxy {
 	 * @return mixed, the result of the specified method
 	 */
 	protected function handleRequest($id, $method, $parameters, $passOnWhen = false) {
-		$result = $this->callOnLastSeenOn($id,  $method, $parameters, $passOnWhen);
-		if ($result === $passOnWhen) {
+		if (!$this->isSingleBackend()) {
+			$result = $this->callOnLastSeenOn($id, $method, $parameters, $passOnWhen);
+		}
+		if (!isset($result) || $result === $passOnWhen) {
 			$result = $this->walkBackends($id, $method, $parameters);
 		}
 		return $result;
diff --git a/apps/user_ldap/lib/User_Proxy.php b/apps/user_ldap/lib/User_Proxy.php
index e9ff92d03e..d4eba412b4 100644
--- a/apps/user_ldap/lib/User_Proxy.php
+++ b/apps/user_ldap/lib/User_Proxy.php
@@ -86,7 +86,9 @@ class User_Proxy extends Proxy implements \OCP\IUserBackend, \OCP\UserInterface,
 				$instance = $this->getAccess($configPrefix);
 			}
 			if ($result = call_user_func_array([$instance, $method], $parameters)) {
-				$this->writeToCache($cacheKey, $configPrefix);
+				if(!$this->isSingleBackend()) {
+					$this->writeToCache($cacheKey, $configPrefix);
+				}
 				return $result;
 			}
 		}
@@ -130,6 +132,10 @@ class User_Proxy extends Proxy implements \OCP\IUserBackend, \OCP\UserInterface,
 		return false;
 	}
 
+	protected function activeBackends(): int {
+		return count($this->backends);
+	}
+
 	/**
 	 * Check if backend implements actions
 	 * @param int $actions bitwise-or'ed actions