Convert services to singletons and use lazy loading to improve performance (#479)

* use singletons to reduce need to recreate the same objects

* unable to make the constructor private

* comment out debug printing to log file

* correct typo of treating self() as a var instead of a function

* utilise Localisation service as a singleton

* fix errent line that should have been commented

* remove phpinfo

* correct mistake in stock controller

* try storing app in apcu

* serialise inside the app closures

* get timings for db-changed-time

* get timings for db-changed-time

* store localisation service in apcu

* stor translations in apcu instead of localisation service (due to database connection)

* correct syntax error

* forgot to uncomment instance map

* correct indentation and variable out of scope

* more timings for app execution time

* try apc caching for views

* correct scope for Pot variable

* remove additional fopen

* correct timings for app build time

* correct timings for app object build time

* correct timings for app route build time

* get timings for routing timings

* get more in depth timings for routing loading

* fix more in depth timings for routing loading

* start investigating session auth middleware creation

* start investigating session auth middleware creation

* start investigating Login controller time

* start investigating Login controller time

* in depth look at Logincontroller timings

* comment out debug printing

* lazily obtain valus for page rendering

* correct syntax error

* correct scope of variable

* correct visibiity of methds inherited from BaseController

* missing use for Userfieldsservice

* lazy loading of open api spec

* lazy loading of users service

* lazy loading of batteries service

* lazy loading of services in controllers

* lazy loading of services in services

* correct mistake

* fix userservice

* fix userservice

* fix userfieldservice

* fix chores service

* fix calendar service

* remove Dockerfile used for development

* Remove docker compose file used for development

* Clean up app.php

* remove last diff

* Clean up base controller

* Clean up controllers

* lean up middleware

* Clean up and tuen all services into singletons

* remove debug from routes.php

* remove acpu from localisation

* Complete removal of acpu from localisation

* fixes for things broken

* More fixes following merge

* Fix for start up bug. Re factoring singleton code had brroken due to scope of clas var.

* fix bug where getUsersService is declared twice

* bug fixes following merge

* bug fixes following merge

* bug fixes following merge

* bug fixes following merge

* bug fixes following merge

* Fix all the not working things...

* Deleted off-topic files

* Deleted off-topic files

Co-authored-by: Bernd Bestel <bernd@berrnd.de>

services/DatabaseService.php

@@ -2,10 +2,22 @@
 
 namespace Grocy\Services;
 
-use \Grocy\Services\ApplicationService;
+#use \Grocy\Services\ApplicationService;
 
 class DatabaseService
 {
+	private static $instance = null;
+
+	public static function getInstance()
+	{
+		if (self::$instance == null)
+		{
+			self::$instance = new self();
+		}
+
+		return self::$instance;
+	}
+
 	private function GetDbFilePath()
 	{
 		if (GROCY_MODE === 'demo' || GROCY_MODE === 'prerelease')
@@ -16,34 +28,34 @@ class DatabaseService
 		return GROCY_DATAPATH . '/grocy.db';
 	}
 
-	private $DbConnectionRaw;
+    private static $DbConnectionRaw = null;
 	/**
 	 * @return \PDO
 	 */
 	public function GetDbConnectionRaw()
 	{
-		if ($this->DbConnectionRaw == null)
+		if (self::$DbConnectionRaw == null)
 		{
 			$pdo = new \PDO('sqlite:' . $this->GetDbFilePath());
 			$pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
-			$this->DbConnectionRaw = $pdo;
+			self::$DbConnectionRaw = $pdo;
 		}
 
-		return $this->DbConnectionRaw;
+		return self::$DbConnectionRaw;
 	}
 
-	private $DbConnection;
+	private static $DbConnection = null;
 	/**
 	 * @return \LessQL\Database
 	 */
 	public function GetDbConnection()
 	{
-		if ($this->DbConnection == null)
+		if (self::$DbConnection == null)
 		{
-			$this->DbConnection = new \LessQL\Database($this->GetDbConnectionRaw());
+			self::$DbConnection = new \LessQL\Database($this->GetDbConnectionRaw());
 		}
 
-		return $this->DbConnection;
+		return self::$DbConnection;
 	}
 
 	/**