Merge pull request #41755 from nextcloud/enh/noid/lazyconfig

Lazy grouping within IAppConfig

12 files changed, 1895 insertions, 307 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 61fd3193fa2..f1de00a49bf 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -273,6 +273,10 @@ return array(
     'OCP\\EventDispatcher\\GenericEvent' => $baseDir . '/lib/public/EventDispatcher/GenericEvent.php',
     'OCP\\EventDispatcher\\IEventDispatcher' => $baseDir . '/lib/public/EventDispatcher/IEventDispatcher.php',
     'OCP\\EventDispatcher\\IEventListener' => $baseDir . '/lib/public/EventDispatcher/IEventListener.php',
+    'OCP\\Exceptions\\AppConfigException' => $baseDir . '/lib/public/Exceptions/AppConfigException.php',
+    'OCP\\Exceptions\\AppConfigIncorrectTypeException' => $baseDir . '/lib/public/Exceptions/AppConfigIncorrectTypeException.php',
+    'OCP\\Exceptions\\AppConfigTypeConflictException' => $baseDir . '/lib/public/Exceptions/AppConfigTypeConflictException.php',
+    'OCP\\Exceptions\\AppConfigUnknownKeyException' => $baseDir . '/lib/public/Exceptions/AppConfigUnknownKeyException.php',
     'OCP\\Federation\\Events\\TrustedServerRemovedEvent' => $baseDir . '/lib/public/Federation/Events/TrustedServerRemovedEvent.php',
     'OCP\\Federation\\Exceptions\\ActionNotSupportedException' => $baseDir . '/lib/public/Federation/Exceptions/ActionNotSupportedException.php',
     'OCP\\Federation\\Exceptions\\AuthenticationFailedException' => $baseDir . '/lib/public/Federation/Exceptions/AuthenticationFailedException.php',
@@ -1237,6 +1241,7 @@ return array(
     'OC\\Core\\Migrations\\Version28000Date20230906104802' => $baseDir . '/core/Migrations/Version28000Date20230906104802.php',
     'OC\\Core\\Migrations\\Version28000Date20231004103301' => $baseDir . '/core/Migrations/Version28000Date20231004103301.php',
     'OC\\Core\\Migrations\\Version28000Date20231103104802' => $baseDir . '/core/Migrations/Version28000Date20231103104802.php',
+    'OC\\Core\\Migrations\\Version29000Date20231126110901' => $baseDir . '/core/Migrations/Version29000Date20231126110901.php',
     'OC\\Core\\Migrations\\Version29000Date20231213104850' => $baseDir . '/core/Migrations/Version29000Date20231213104850.php',
     'OC\\Core\\Notification\\CoreNotifier' => $baseDir . '/core/Notification/CoreNotifier.php',
     'OC\\Core\\Service\\LoginFlowV2Service' => $baseDir . '/core/Service/LoginFlowV2Service.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index eaacd3939c4..017918b3f44 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -306,6 +306,10 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OCP\\EventDispatcher\\GenericEvent' => __DIR__ . '/../../..' . '/lib/public/EventDispatcher/GenericEvent.php',
         'OCP\\EventDispatcher\\IEventDispatcher' => __DIR__ . '/../../..' . '/lib/public/EventDispatcher/IEventDispatcher.php',
         'OCP\\EventDispatcher\\IEventListener' => __DIR__ . '/../../..' . '/lib/public/EventDispatcher/IEventListener.php',
+        'OCP\\Exceptions\\AppConfigException' => __DIR__ . '/../../..' . '/lib/public/Exceptions/AppConfigException.php',
+        'OCP\\Exceptions\\AppConfigIncorrectTypeException' => __DIR__ . '/../../..' . '/lib/public/Exceptions/AppConfigIncorrectTypeException.php',
+        'OCP\\Exceptions\\AppConfigTypeConflictException' => __DIR__ . '/../../..' . '/lib/public/Exceptions/AppConfigTypeConflictException.php',
+        'OCP\\Exceptions\\AppConfigUnknownKeyException' => __DIR__ . '/../../..' . '/lib/public/Exceptions/AppConfigUnknownKeyException.php',
         'OCP\\Federation\\Events\\TrustedServerRemovedEvent' => __DIR__ . '/../../..' . '/lib/public/Federation/Events/TrustedServerRemovedEvent.php',
         'OCP\\Federation\\Exceptions\\ActionNotSupportedException' => __DIR__ . '/../../..' . '/lib/public/Federation/Exceptions/ActionNotSupportedException.php',
         'OCP\\Federation\\Exceptions\\AuthenticationFailedException' => __DIR__ . '/../../..' . '/lib/public/Federation/Exceptions/AuthenticationFailedException.php',
@@ -1270,6 +1274,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Core\\Migrations\\Version28000Date20230906104802' => __DIR__ . '/../../..' . '/core/Migrations/Version28000Date20230906104802.php',
         'OC\\Core\\Migrations\\Version28000Date20231004103301' => __DIR__ . '/../../..' . '/core/Migrations/Version28000Date20231004103301.php',
         'OC\\Core\\Migrations\\Version28000Date20231103104802' => __DIR__ . '/../../..' . '/core/Migrations/Version28000Date20231103104802.php',
+        'OC\\Core\\Migrations\\Version29000Date20231126110901' => __DIR__ . '/../../..' . '/core/Migrations/Version29000Date20231126110901.php',
         'OC\\Core\\Migrations\\Version29000Date20231213104850' => __DIR__ . '/../../..' . '/core/Migrations/Version29000Date20231213104850.php',
         'OC\\Core\\Notification\\CoreNotifier' => __DIR__ . '/../../..' . '/core/Notification/CoreNotifier.php',
         'OC\\Core\\Service\\LoginFlowV2Service' => __DIR__ . '/../../..' . '/core/Service/LoginFlowV2Service.php',
diff --git a/lib/private/AllConfig.php b/lib/private/AllConfig.php
index 92178d64635..ab4359c798f 100644
--- a/lib/private/AllConfig.php
+++ b/lib/private/AllConfig.php
@@ -43,7 +43,6 @@ use OCP\PreConditionNotMetException;
  * Class to combine all the configuration options ownCloud offers
  */
 class AllConfig implements IConfig {
-	private SystemConfig $systemConfig;
 	private ?IDBConnection $connection = null;
 
 	/**
@@ -68,9 +67,10 @@ class AllConfig implements IConfig {
 	 */
 	private CappedMemoryCache $userCache;
 
-	public function __construct(SystemConfig $systemConfig) {
+	public function __construct(
+		private SystemConfig $systemConfig
+	) {
 		$this->userCache = new CappedMemoryCache();
-		$this->systemConfig = $systemConfig;
 	}
 
 	/**
@@ -190,6 +190,7 @@ class AllConfig implements IConfig {
 	 *
 	 * @param string $appName the appName that we stored the value under
 	 * @return string[] the keys stored for the app
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function getAppKeys($appName) {
 		return \OC::$server->get(AppConfig::class)->getKeys($appName);
@@ -201,6 +202,7 @@ class AllConfig implements IConfig {
 	 * @param string $appName the appName that we want to store the value under
 	 * @param string $key the key of the value, under which will be saved
 	 * @param string|float|int $value the value that should be stored
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function setAppValue($appName, $key, $value) {
 		\OC::$server->get(AppConfig::class)->setValue($appName, $key, $value);
@@ -213,6 +215,7 @@ class AllConfig implements IConfig {
 	 * @param string $key the key of the value, under which it was saved
 	 * @param string $default the default value to be returned if the value isn't set
 	 * @return string the saved value
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function getAppValue($appName, $key, $default = '') {
 		return \OC::$server->get(AppConfig::class)->getValue($appName, $key, $default);
@@ -223,6 +226,7 @@ class AllConfig implements IConfig {
 	 *
 	 * @param string $appName the appName that we stored the value under
 	 * @param string $key the key of the value, under which it was saved
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function deleteAppValue($appName, $key) {
 		\OC::$server->get(AppConfig::class)->deleteKey($appName, $key);
@@ -232,6 +236,7 @@ class AllConfig implements IConfig {
 	 * Removes all keys in appconfig belonging to the app
 	 *
 	 * @param string $appName the appName the configs are stored under
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function deleteAppValues($appName) {
 		\OC::$server->get(AppConfig::class)->deleteApp($appName);
diff --git a/lib/private/AppConfig.php b/lib/private/AppConfig.php
index f92abb2caad..e8192530c17 100644
--- a/lib/private/AppConfig.php
+++ b/lib/private/AppConfig.php
@@ -1,4 +1,6 @@
 <?php
+
+declare(strict_types=1);
 /**
  * @copyright Copyright (c) 2017, Joas Schilling <coding@schilljs.com>
  * @copyright Copyright (c) 2016, ownCloud, Inc.
@@ -9,6 +11,7 @@
  * @author Jakob Sack <mail@jakobsack.de>
  * @author Joas Schilling <coding@schilljs.com>
  * @author Jörn Friedrich Dreyer <jfd@butonic.de>
+ * @author Maxence Lange <maxence@artificial-owl.com>
  * @author michaelletzgus <michaelletzgus@users.noreply.github.com>
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Robin Appelman <robin@icewind.nl>
@@ -30,416 +33,1397 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>
  *
  */
+
 namespace OC;
 
-use OC\DB\Connection;
-use OC\DB\OracleConnection;
+use InvalidArgumentException;
+use JsonException;
+use OCP\DB\Exception as DBException;
 use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\Exceptions\AppConfigIncorrectTypeException;
+use OCP\Exceptions\AppConfigTypeConflictException;
+use OCP\Exceptions\AppConfigUnknownKeyException;
 use OCP\IAppConfig;
 use OCP\IConfig;
+use OCP\IDBConnection;
+use Psr\Log\LoggerInterface;
 
 /**
  * This class provides an easy way for apps to store config values in the
  * database.
+ *
+ * **Note:** since 29.0.0, it supports **lazy loading**
+ *
+ * ### What is lazy loading ?
+ * In order to avoid loading useless config values into memory for each request,
+ * only non-lazy values are now loaded.
+ *
+ * Once a value that is lazy is requested, all lazy values will be loaded.
+ *
+ * Similarly, some methods from this class are marked with a warning about ignoring
+ * lazy loading. Use them wisely and only on parts of the code that are called
+ * during specific requests or actions to avoid loading the lazy values all the time.
+ *
+ * @since 7.0.0
+ * @since 29.0.0 - Supporting types and lazy loading
  */
 class AppConfig implements IAppConfig {
-	/** @var array[] */
-	protected $sensitiveValues = [
-		'circles' => [
-			'/^key_pairs$/',
-			'/^local_gskey$/',
-		],
-		'external' => [
-			'/^sites$/',
-		],
-		'integration_discourse' => [
-			'/^private_key$/',
-			'/^public_key$/',
-		],
-		'integration_dropbox' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-		],
-		'integration_github' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-		],
-		'integration_gitlab' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-			'/^oauth_instance_url$/',
-		],
-		'integration_google' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-		],
-		'integration_jira' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-			'/^forced_instance_url$/',
-		],
-		'integration_onedrive' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-		],
-		'integration_openproject' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-			'/^oauth_instance_url$/',
-		],
-		'integration_reddit' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-		],
-		'integration_suitecrm' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-			'/^oauth_instance_url$/',
-		],
-		'integration_twitter' => [
-			'/^consumer_key$/',
-			'/^consumer_secret$/',
-			'/^followed_user$/',
-		],
-		'integration_zammad' => [
-			'/^client_id$/',
-			'/^client_secret$/',
-			'/^oauth_instance_url$/',
-		],
-		'notify_push' => [
-			'/^cookie$/',
-		],
-		'serverinfo' => [
-			'/^token$/',
-		],
-		'spreed' => [
-			'/^bridge_bot_password$/',
-			'/^hosted-signaling-server-(.*)$/',
-			'/^recording_servers$/',
-			'/^signaling_servers$/',
-			'/^signaling_ticket_secret$/',
-			'/^signaling_token_privkey_(.*)$/',
-			'/^signaling_token_pubkey_(.*)$/',
-			'/^sip_bridge_dialin_info$/',
-			'/^sip_bridge_shared_secret$/',
-			'/^stun_servers$/',
-			'/^turn_servers$/',
-			'/^turn_server_secret$/',
-		],
-		'support' => [
-			'/^last_response$/',
-			'/^potential_subscription_key$/',
-			'/^subscription_key$/',
-		],
-		'theming' => [
-			'/^imprintUrl$/',
-			'/^privacyUrl$/',
-			'/^slogan$/',
-			'/^url$/',
-		],
-		'user_ldap' => [
-			'/^(s..)?ldap_agent_password$/',
-		],
-		'user_saml' => [
-			'/^idp-x509cert$/',
-		],
-	];
-
-	/** @var Connection */
-	protected $conn;
-
-	/** @var array[] */
-	private $cache = [];
-
-	/** @var bool */
-	private $configLoaded = false;
-
-	/**
-	 * @param Connection $conn
-	 */
-	public function __construct(Connection $conn) {
-		$this->conn = $conn;
+	private const APP_MAX_LENGTH = 32;
+	private const KEY_MAX_LENGTH = 64;
+
+	/** @var array<string, array<string, mixed>> ['app_id' => ['config_key' => 'config_value']] */
+	private array $fastCache = [];   // cache for normal config keys
+	/** @var array<string, array<string, mixed>> ['app_id' => ['config_key' => 'config_value']] */
+	private array $lazyCache = [];   // cache for lazy config keys
+	/** @var array<string, array<string, int>> ['app_id' => ['config_key' => bitflag]] */
+	private array $valueTypes = [];  // type for all config values
+	private bool $fastLoaded = false;
+	private bool $lazyLoaded = false;
+
+	/**
+	 * $migrationCompleted is only needed to manage the previous structure
+	 * of the database during the upgrading process to nc29.
+	 * @TODO: remove this value in Nextcloud 30+
+	 */
+	private bool $migrationCompleted = true;
+
+	public function __construct(
+		protected IDBConnection $connection,
+		private LoggerInterface $logger,
+	) {
 	}
 
 	/**
-	 * @param string $app
-	 * @return array
+	 * @inheritDoc
+	 *
+	 * @return string[] list of app ids
+	 * @since 7.0.0
+	 */
+	public function getApps(): array {
+		$this->loadConfigAll();
+		$apps = array_merge(array_keys($this->fastCache), array_keys($this->lazyCache));
+		sort($apps);
+
+		return array_values(array_unique($apps));
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 *
+	 * @return string[] list of stored config keys
+	 * @since 29.0.0
+	 */
+	public function getKeys(string $app): array {
+		$this->assertParams($app);
+		$this->loadConfigAll();
+		$keys = array_merge(array_keys($this->fastCache[$app] ?? []), array_keys($this->lazyCache[$app] ?? []));
+		sort($keys);
+
+		return array_values(array_unique($keys));
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool|null $lazy TRUE to search within lazy loaded config, NULL to search within all config
+	 *
+	 * @return bool TRUE if key exists
+	 * @since 7.0.0
+	 * @since 29.0.0 Added the $lazy argument
 	 */
-	private function getAppValues($app) {
-		$this->loadConfigValues();
+	public function hasKey(string $app, string $key, ?bool $lazy = false): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfig($lazy);
 
-		if (isset($this->cache[$app])) {
-			return $this->cache[$app];
+		if ($lazy === null) {
+			$appCache = $this->getAllValues($app);
+			return isset($appCache[$key]);
 		}
 
-		return [];
+		if ($lazy) {
+			return isset($this->lazyCache[$app][$key]);
+		}
+
+		return isset($this->fastCache[$app][$key]);
+	}
+
+	/**
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool|null $lazy TRUE to search within lazy loaded config, NULL to search within all config
+	 *
+	 * @return bool
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @since 29.0.0
+	 */
+	public function isSensitive(string $app, string $key, ?bool $lazy = false): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfig($lazy);
+
+		return $this->isTyped(self::VALUE_SENSITIVE, $this->valueTypes[$app][$key] ?? throw new AppConfigUnknownKeyException('unknown config key'));
 	}
 
 	/**
-	 * Get all apps using the config
+	 * @inheritDoc
 	 *
-	 * @return string[] an array of app ids
+	 * @param string $app if of the app
+	 * @param string $key config key
 	 *
-	 * This function returns a list of all apps that have at least one
-	 * entry in the appconfig table.
+	 * @return bool TRUE if config is lazy loaded
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @see IAppConfig for details about lazy loading
+	 * @since 29.0.0
 	 */
-	public function getApps() {
-		$this->loadConfigValues();
+	public function isLazy(string $app, string $key): bool {
+		// there is a huge probability the non-lazy config are already loaded
+		if ($this->hasKey($app, $key, false)) {
+			return false;
+		}
+
+		// key not found, we search in the lazy config
+		if ($this->hasKey($app, $key, true)) {
+			return true;
+		}
 
-		return $this->getSortedKeys($this->cache);
+		throw new AppConfigUnknownKeyException('unknown config key');
 	}
 
+
 	/**
-	 * Get the available keys for an app
+	 * @inheritDoc
 	 *
-	 * @param string $app the app we are looking for
-	 * @return array an array of key names
+	 * @param string $app id of the app
+	 * @param string $key config keys prefix to search
+	 * @param bool $filtered TRUE to hide sensitive config values. Value are replaced by {@see IConfig::SENSITIVE_VALUE}
 	 *
-	 * This function gets all keys of an app. Please note that the values are
-	 * not returned.
+	 * @return array<string, string> [configKey => configValue]
+	 * @since 29.0.0
 	 */
-	public function getKeys($app) {
-		$this->loadConfigValues();
+	public function getAllValues(string $app, string $key = '', bool $filtered = false): array {
+		$this->assertParams($app, $key);
+		// if we want to filter values, we need to get sensitivity
+		$this->loadConfigAll();
+		// array_merge() will remove numeric keys (here config keys), so addition arrays instead
+		$values = ($this->fastCache[$app] ?? []) + ($this->lazyCache[$app] ?? []);
+
+		if (!$filtered) {
+			return $values;
+		}
+
+		/**
+		 * Using the old (deprecated) list of sensitive values.
+		 */
+		foreach ($this->getSensitiveKeys($app) as $sensitiveKeyExp) {
+			$sensitiveKeys = preg_grep($sensitiveKeyExp, array_keys($values));
+			foreach ($sensitiveKeys as $sensitiveKey) {
+				$this->valueTypes[$app][$sensitiveKey] = ($this->valueTypes[$app][$sensitiveKey] ?? 0) | self::VALUE_SENSITIVE;
+			}
+		}
 
-		if (isset($this->cache[$app])) {
-			return $this->getSortedKeys($this->cache[$app]);
+		$result = [];
+		foreach ($values as $key => $value) {
+			$result[$key] = $this->isTyped(self::VALUE_SENSITIVE, $this->valueTypes[$app][$key] ?? 0) ? IConfig::SENSITIVE_VALUE : $value;
 		}
 
-		return [];
+		return $result;
 	}
 
-	public function getSortedKeys($data) {
-		$keys = array_keys($data);
-		sort($keys);
-		return $keys;
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $key config key
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return array<string, string> [appId => configValue]
+	 * @since 29.0.0
+	 */
+	public function searchValues(string $key, bool $lazy = false): array {
+		$this->assertParams('', $key, true);
+		$this->loadConfig($lazy);
+		$values = [];
+
+		/** @var array<array-key, array<array-key, mixed>> $cache */
+		if ($lazy) {
+			$cache = $this->lazyCache;
+		} else {
+			$cache = $this->fastCache;
+		}
+
+		foreach (array_keys($cache) as $app) {
+			if (isset($cache[$app][$key])) {
+				$values[$app] = $cache[$app][$key];
+			}
+		}
+
+		return $values;
 	}
 
+
 	/**
-	 * Gets the config value
+	 * Get the config value as string.
+	 * If the value does not exist the given default will be returned.
+	 *
+	 * Set lazy to `null` to ignore it and get the value from either source.
+	 *
+	 * **WARNING:** Method is internal and **SHOULD** not be used, as it is better to get the value with a type.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $default config value
+	 * @param null|bool $lazy get config as lazy loaded or not. can be NULL
 	 *
-	 * @param string $app app
-	 * @param string $key key
-	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @internal
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueString()
+	 * @see getValueInt()
+	 * @see getValueFloat()
+	 * @see getValueBool()
+	 * @see getValueArray()
+	 */
+	public function getValueMixed(
+		string $app,
+		string $key,
+		string $default = '',
+		?bool $lazy = false
+	): string {
+		return $this->getTypedValue(
+			$app,
+			$key,
+			$default,
+			($lazy === null) ? $this->isLazy($app, $key) : $lazy,
+			self::VALUE_MIXED
+		);
+	}
+
+	/**
+	 * @inheritDoc
 	 *
-	 * This function gets a value from the appconfig table. If the key does
-	 * not exist the default value will be returned
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return string stored config value or $default if not set in database
+	 * @throws InvalidArgumentException if one of the argument format is invalid
+	 * @throws AppConfigTypeConflictException in case of conflict with the value type set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
 	 */
-	public function getValue($app, $key, $default = null) {
-		$this->loadConfigValues();
+	public function getValueString(
+		string $app,
+		string $key,
+		string $default = '',
+		bool $lazy = false
+	): string {
+		return $this->getTypedValue($app, $key, $default, $lazy, self::VALUE_STRING);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param int $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return int stored config value or $default if not set in database
+	 * @throws InvalidArgumentException if one of the argument format is invalid
+	 * @throws AppConfigTypeConflictException in case of conflict with the value type set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function getValueInt(
+		string $app,
+		string $key,
+		int $default = 0,
+		bool $lazy = false
+	): int {
+		return (int)$this->getTypedValue($app, $key, (string)$default, $lazy, self::VALUE_INT);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param float $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return float stored config value or $default if not set in database
+	 * @throws InvalidArgumentException if one of the argument format is invalid
+	 * @throws AppConfigTypeConflictException in case of conflict with the value type set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function getValueFloat(string $app, string $key, float $default = 0, bool $lazy = false): float {
+		return (float)$this->getTypedValue($app, $key, (string)$default, $lazy, self::VALUE_FLOAT);
+	}
 
-		if ($this->hasKey($app, $key)) {
-			return $this->cache[$app][$key];
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return bool stored config value or $default if not set in database
+	 * @throws InvalidArgumentException if one of the argument format is invalid
+	 * @throws AppConfigTypeConflictException in case of conflict with the value type set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function getValueBool(string $app, string $key, bool $default = false, bool $lazy = false): bool {
+		$b = strtolower($this->getTypedValue($app, $key, $default ? 'true' : 'false', $lazy, self::VALUE_BOOL));
+		return in_array($b, ['1', 'true', 'yes', 'on']);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param array $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return array stored config value or $default if not set in database
+	 * @throws InvalidArgumentException if one of the argument format is invalid
+	 * @throws AppConfigTypeConflictException in case of conflict with the value type set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function getValueArray(
+		string $app,
+		string $key,
+		array $default = [],
+		bool $lazy = false
+	): array {
+		try {
+			$defaultJson = json_encode($default, JSON_THROW_ON_ERROR);
+			$value = json_decode($this->getTypedValue($app, $key, $defaultJson, $lazy, self::VALUE_ARRAY), true, flags: JSON_THROW_ON_ERROR);
+
+			return is_array($value) ? $value : [];
+		} catch (JsonException) {
+			return [];
+		}
+	}
+
+	/**
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 * @param int $type value type {@see VALUE_STRING} {@see VALUE_INT}{@see VALUE_FLOAT} {@see VALUE_BOOL} {@see VALUE_ARRAY}
+	 *
+	 * @return string
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @throws InvalidArgumentException
+	 */
+	private function getTypedValue(
+		string $app,
+		string $key,
+		string $default,
+		bool $lazy,
+		int $type
+	): string {
+		$this->assertParams($app, $key, valueType: $type);
+		$this->loadConfig($lazy);
+
+		/**
+		 * We ignore check if mixed type is requested.
+		 * If type of stored value is set as mixed, we don't filter.
+		 * If type of stored value is defined, we compare with the one requested.
+		 */
+		$knownType = $this->valueTypes[$app][$key] ?? 0;
+		if (!$this->isTyped(self::VALUE_MIXED, $type)
+			&& $knownType > 0
+			&& !$this->isTyped(self::VALUE_MIXED, $knownType)
+			&& !$this->isTyped($type, $knownType)) {
+			$this->logger->warning('conflict with value type from database', ['app' => $app, 'key' => $key, 'type' => $type, 'knownType' => $knownType]);
+			throw new AppConfigTypeConflictException('conflict with value type from database');
 		}
 
-		return $default;
+		if ($lazy) {
+			return $this->lazyCache[$app][$key] ?? $default;
+		}
+
+		return $this->fastCache[$app][$key] ?? $default;
 	}
 
 	/**
-	 * check if a key is set in the appconfig
+	 * @inheritDoc
 	 *
-	 * @param string $app
-	 * @param string $key
-	 * @return bool
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @return int type of the value
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @since 29.0.0
+	 * @see VALUE_STRING
+	 * @see VALUE_INT
+	 * @see VALUE_FLOAT
+	 * @see VALUE_BOOL
+	 * @see VALUE_ARRAY
 	 */
-	public function hasKey($app, $key) {
-		$this->loadConfigValues();
+	public function getValueType(string $app, string $key): int {
+		$this->assertParams($app, $key);
+		$this->loadConfigAll();
+
+		if (!isset($this->valueTypes[$app][$key])) {
+			throw new AppConfigUnknownKeyException('unknown config key');
+		}
 
-		return isset($this->cache[$app][$key]);
+		$type = $this->valueTypes[$app][$key];
+		$type &= ~self::VALUE_SENSITIVE;
+		return $type;
 	}
 
+
 	/**
-	 * Sets a value. If the key did not exist before it will be created.
+	 * Store a config key and its value in database as VALUE_MIXED
 	 *
-	 * @param string $app app
-	 * @param string $key key
-	 * @param string|float|int $value value
-	 * @return bool True if the value was inserted or updated, false if the value was the same
+	 * **WARNING:** Method is internal and **MUST** not be used as it is best to set a real value type
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED
+	 * @internal
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueString()
+	 * @see setValueInt()
+	 * @see setValueFloat()
+	 * @see setValueBool()
+	 * @see setValueArray()
 	 */
-	public function setValue($app, $key, $value) {
-		if (!$this->hasKey($app, $key)) {
-			$inserted = (bool) $this->conn->insertIfNotExist('*PREFIX*appconfig', [
-				'appid' => $app,
-				'configkey' => $key,
-				'configvalue' => $value,
-			], [
-				'appid',
-				'configkey',
-			]);
-
-			if ($inserted) {
-				if (!isset($this->cache[$app])) {
-					$this->cache[$app] = [];
-				}
+	public function setValueMixed(
+		string $app,
+		string $key,
+		string $value,
+		bool $lazy = false,
+		bool $sensitive = false
+	): bool {
+		return $this->setTypedValue(
+			$app,
+			$key,
+			$value,
+			$lazy,
+			self::VALUE_MIXED | ($sensitive ? self::VALUE_SENSITIVE : 0)
+		);
+	}
 
-				$this->cache[$app][$key] = $value;
-				return true;
-			}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function setValueString(
+		string $app,
+		string $key,
+		string $value,
+		bool $lazy = false,
+		bool $sensitive = false
+	): bool {
+		return $this->setTypedValue(
+			$app,
+			$key,
+			$value,
+			$lazy,
+			self::VALUE_STRING | ($sensitive ? self::VALUE_SENSITIVE : 0)
+		);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param int $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function setValueInt(
+		string $app,
+		string $key,
+		int $value,
+		bool $lazy = false,
+		bool $sensitive = false
+	): bool {
+		if ($value > 2000000000) {
+			$this->logger->debug('You are trying to store an integer value around/above 2,147,483,647. This is a reminder that reaching this theoretical limit on 32 bits system will throw an exception.');
 		}
 
-		$sql = $this->conn->getQueryBuilder();
-		$sql->update('appconfig')
-			->set('configvalue', $sql->createNamedParameter($value))
-			->where($sql->expr()->eq('appid', $sql->createNamedParameter($app)))
-			->andWhere($sql->expr()->eq('configkey', $sql->createNamedParameter($key)));
+		return $this->setTypedValue(
+			$app,
+			$key,
+			(string)$value,
+			$lazy,
+			self::VALUE_INT | ($sensitive ? self::VALUE_SENSITIVE : 0)
+		);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param float $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function setValueFloat(
+		string $app,
+		string $key,
+		float $value,
+		bool $lazy = false,
+		bool $sensitive = false
+	): bool {
+		return $this->setTypedValue(
+			$app,
+			$key,
+			(string)$value,
+			$lazy,
+			self::VALUE_FLOAT | ($sensitive ? self::VALUE_SENSITIVE : 0)
+		);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function setValueBool(
+		string $app,
+		string $key,
+		bool $value,
+		bool $lazy = false
+	): bool {
+		return $this->setTypedValue(
+			$app,
+			$key,
+			($value) ? '1' : '0',
+			$lazy,
+			self::VALUE_BOOL
+		);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param array $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @throws JsonException
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	public function setValueArray(
+		string $app,
+		string $key,
+		array $value,
+		bool $lazy = false,
+		bool $sensitive = false
+	): bool {
+		try {
+			return $this->setTypedValue(
+				$app,
+				$key,
+				json_encode($value, JSON_THROW_ON_ERROR),
+				$lazy,
+				self::VALUE_ARRAY | ($sensitive ? self::VALUE_SENSITIVE : 0)
+			);
+		} catch (JsonException $e) {
+			$this->logger->warning('could not setValueArray', ['app' => $app, 'key' => $key, 'exception' => $e]);
+			throw $e;
+		}
+	}
+
+	/**
+	 * Store a config key and its value in database
+	 *
+	 * If config key is already known with the exact same config value and same sensitive/lazy status, the
+	 * database is not updated. If config value was previously stored as sensitive, status will not be
+	 * altered.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $value config value
+	 * @param bool $lazy config set as lazy loaded
+	 * @param int $type value type {@see VALUE_STRING} {@see VALUE_INT} {@see VALUE_FLOAT} {@see VALUE_BOOL} {@see VALUE_ARRAY}
+	 *
+	 * @return bool TRUE if value was updated in database
+	 * @throws AppConfigTypeConflictException if type from database is not VALUE_MIXED and different from the requested one
+	 * @see IAppConfig for explanation about lazy loading
+	 */
+	private function setTypedValue(
+		string $app,
+		string $key,
+		string $value,
+		bool $lazy,
+		int $type
+	): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfig($lazy);
+
+		$sensitive = $this->isTyped(self::VALUE_SENSITIVE, $type);
 
 		/*
-		 * Only limit to the existing value for non-Oracle DBs:
-		 * http://docs.oracle.com/cd/E11882_01/server.112/e26088/conditions002.htm#i1033286
-		 * > Large objects (LOBs) are not supported in comparison conditions.
+		 * no update if key is already known with set lazy status, or value is
+		 * different, or sensitivity switched from false to true.
 		 */
-		if (!($this->conn instanceof OracleConnection)) {
-			/*
-			 * Only update the value when it is not the same
-			 * Note that NULL requires some special handling. Since comparing
-			 * against null can have special results.
+		if ($this->hasKey($app, $key, $lazy)
+			&& $value === $this->getTypedValue($app, $key, $value, $lazy, $type)
+			&& (!$sensitive || $this->isSensitive($app, $key, $lazy))) {
+			return false;
+		}
+
+		$refreshCache = false;
+		$insert = $this->connection->getQueryBuilder();
+		$insert->insert('appconfig')
+			   ->setValue('appid', $insert->createNamedParameter($app))
+			   ->setValue('lazy', $insert->createNamedParameter($lazy, IQueryBuilder::PARAM_BOOL))
+			   ->setValue('type', $insert->createNamedParameter($type, IQueryBuilder::PARAM_INT))
+			   ->setValue('configkey', $insert->createNamedParameter($key))
+			   ->setValue('configvalue', $insert->createNamedParameter($value));
+		try {
+			$insert->executeStatement();
+		} catch (DBException $e) {
+			if ($e->getReason() !== DBException::REASON_UNIQUE_CONSTRAINT_VIOLATION) {
+				throw $e; // TODO: throw exception or just log and returns false !?
+			}
+
+			$currType = $this->valueTypes[$app][$key] ?? 0;
+			if ($currType === 0) { // this might happen when switching lazy loading status
+				$this->loadConfigAll();
+				$currType = $this->valueTypes[$app][$key] ?? 0;
+			}
+
+			/**
+			 * This should only happen during the upgrade process from 28 to 29.
+			 * We only log a warning and set it to VALUE_MIXED.
 			 */
+			if ($currType === 0) {
+				$this->logger->warning('Value type is set to zero (0) in database. This is fine only during the upgrade process from 28 to 29.', ['app' => $app, 'key' => $key]);
+				$currType = self::VALUE_MIXED;
+			}
 
-			if ($value === null) {
-				$sql->andWhere(
-					$sql->expr()->isNotNull('configvalue')
-				);
-			} else {
-				$sql->andWhere(
-					$sql->expr()->orX(
-						$sql->expr()->isNull('configvalue'),
-						$sql->expr()->neq('configvalue', $sql->createNamedParameter($value), IQueryBuilder::PARAM_STR)
-					)
-				);
+			/**
+			 * we only accept a different type from the one stored in database
+			 * if the one stored in database is not-defined (VALUE_MIXED)
+			 */
+			if (!$this->isTyped(self::VALUE_MIXED, $currType) &&
+				($type | self::VALUE_SENSITIVE) !== ($currType | self::VALUE_SENSITIVE)) {
+				try {
+					$currType = $this->convertTypeToString($currType);
+					$type = $this->convertTypeToString($type);
+				} catch (AppConfigIncorrectTypeException) {
+					// can be ignored, this was just needed for a better exception message.
+				}
+				throw new AppConfigTypeConflictException('conflict between new type (' . $type . ') and old type (' . $currType . ')');
 			}
+
+			// we fix $type if the stored value, or the new value as it might be changed, is set as sensitive
+			if ($sensitive || $this->isTyped(self::VALUE_SENSITIVE, $currType)) {
+				$type = $type | self::VALUE_SENSITIVE;
+			}
+
+			if ($lazy !== $this->isLazy($app, $key)) {
+				$refreshCache = true;
+			}
+
+			$update = $this->connection->getQueryBuilder();
+			$update->update('appconfig')
+				   ->set('configvalue', $update->createNamedParameter($value))
+				   ->set('lazy', $update->createNamedParameter($lazy, IQueryBuilder::PARAM_BOOL))
+				   ->set('type', $update->createNamedParameter($type, IQueryBuilder::PARAM_INT))
+				   ->where($update->expr()->eq('appid', $update->createNamedParameter($app)))
+				   ->andWhere($update->expr()->eq('configkey', $update->createNamedParameter($key)));
+
+			$update->executeStatement();
 		}
 
-		$changedRow = (bool) $sql->execute();
+		if ($refreshCache) {
+			$this->clearCache();
+			return true;
+		}
 
-		$this->cache[$app][$key] = $value;
+		// update local cache
+		if ($lazy) {
+			$cache = &$this->lazyCache;
+		} else {
+			$cache = &$this->fastCache;
+		}
+		$cache[$app][$key] = $value;
+		$this->valueTypes[$app][$key] = $type;
 
-		return $changedRow;
+		return true;
 	}
 
 	/**
-	 * Deletes a key
+	 * Change the type of config value.
 	 *
-	 * @param string $app app
-	 * @param string $key key
-	 * @return boolean
+	 * **WARNING:** Method is internal and **MUST** not be used as it may break things.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param int $type value type {@see VALUE_STRING} {@see VALUE_INT} {@see VALUE_FLOAT} {@see VALUE_BOOL} {@see VALUE_ARRAY}
+	 *
+	 * @return bool TRUE if database update were necessary
+	 * @throws AppConfigUnknownKeyException if $key is now known in database
+	 * @throws AppConfigIncorrectTypeException if $type is not valid
+	 * @internal
+	 * @since 29.0.0
 	 */
-	public function deleteKey($app, $key) {
-		$this->loadConfigValues();
+	public function updateType(string $app, string $key, int $type = self::VALUE_MIXED): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfigAll();
+		$lazy = $this->isLazy($app, $key);
+
+		if (!$this->hasKey($app, $key, $lazy)) {
+			throw new AppConfigUnknownKeyException('Unknown config key');
+		}
+
+		// type can only be one type
+		if (!in_array($type, [self::VALUE_MIXED, self::VALUE_STRING, self::VALUE_INT, self::VALUE_FLOAT, self::VALUE_BOOL, self::VALUE_ARRAY])) {
+			throw new AppConfigIncorrectTypeException('Unknown value type');
+		}
+
+		$currType = $this->valueTypes[$app][$key];
+		if (($type | self::VALUE_SENSITIVE) === ($currType | self::VALUE_SENSITIVE)) {
+			return false;
+		}
+
+		// we complete with sensitive flag if the stored value is set as sensitive
+		if ($this->isTyped(self::VALUE_SENSITIVE, $currType)) {
+			$type = $type | self::VALUE_SENSITIVE;
+		}
 
-		$sql = $this->conn->getQueryBuilder();
-		$sql->delete('appconfig')
-			->where($sql->expr()->eq('appid', $sql->createParameter('app')))
-			->andWhere($sql->expr()->eq('configkey', $sql->createParameter('configkey')))
-			->setParameter('app', $app)
-			->setParameter('configkey', $key);
-		$sql->execute();
+		$update = $this->connection->getQueryBuilder();
+		$update->update('appconfig')
+			   ->set('type', $update->createNamedParameter($type, IQueryBuilder::PARAM_INT))
+			   ->where($update->expr()->eq('appid', $update->createNamedParameter($app)))
+			   ->andWhere($update->expr()->eq('configkey', $update->createNamedParameter($key)));
+		$update->executeStatement();
+		$this->valueTypes[$app][$key] = $type;
 
-		unset($this->cache[$app][$key]);
-		return false;
+		return true;
 	}
 
+
 	/**
-	 * Remove app from appconfig
+	 * @inheritDoc
 	 *
-	 * @param string $app app
-	 * @return boolean
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $sensitive TRUE to set as sensitive, FALSE to unset
 	 *
-	 * Removes all keys in appconfig belonging to the app.
+	 * @return bool TRUE if database update were necessary
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @since 29.0.0
 	 */
-	public function deleteApp($app) {
-		$this->loadConfigValues();
+	public function updateSensitive(string $app, string $key, bool $sensitive): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfigAll();
 
-		$sql = $this->conn->getQueryBuilder();
-		$sql->delete('appconfig')
-			->where($sql->expr()->eq('appid', $sql->createParameter('app')))
-			->setParameter('app', $app);
-		$sql->execute();
+		if ($sensitive === $this->isSensitive($app, $key, null)) {
+			return false;
+		}
+
+		/**
+		 * type returned by getValueType() is already cleaned from sensitive flag
+		 * we just need to update it based on $sensitive and store it in database
+		 */
+		$type = $this->getValueType($app, $key);
+		if ($sensitive) {
+			$type = $type | self::VALUE_SENSITIVE;
+		}
+
+		$update = $this->connection->getQueryBuilder();
+		$update->update('appconfig')
+			   ->set('type', $update->createNamedParameter($type, IQueryBuilder::PARAM_INT))
+			   ->where($update->expr()->eq('appid', $update->createNamedParameter($app)))
+			   ->andWhere($update->expr()->eq('configkey', $update->createNamedParameter($key)));
+		$update->executeStatement();
 
-		unset($this->cache[$app]);
-		return false;
+		$this->valueTypes[$app][$key] = $type;
+
+		return true;
 	}
 
 	/**
-	 * get multiple values, either the app or key can be used as wildcard by setting it to false
+	 * @inheritDoc
 	 *
-	 * @param string|false $app
-	 * @param string|false $key
-	 * @return array|false
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $lazy TRUE to set as lazy loaded, FALSE to unset
+	 *
+	 * @return bool TRUE if database update was necessary
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @since 29.0.0
 	 */
-	public function getValues($app, $key) {
-		if (($app !== false) === ($key !== false)) {
+	public function updateLazy(string $app, string $key, bool $lazy): bool {
+		$this->assertParams($app, $key);
+		$this->loadConfigAll();
+
+		if ($lazy === $this->isLazy($app, $key)) {
 			return false;
 		}
 
-		if ($key === false) {
-			return $this->getAppValues($app);
+		$update = $this->connection->getQueryBuilder();
+		$update->update('appconfig')
+			   ->set('lazy', $update->createNamedParameter($lazy, IQueryBuilder::PARAM_BOOL))
+			   ->where($update->expr()->eq('appid', $update->createNamedParameter($app)))
+			   ->andWhere($update->expr()->eq('configkey', $update->createNamedParameter($key)));
+		$update->executeStatement();
+
+		// At this point, it is a lot safer to clean cache
+		$this->clearCache();
+
+		return true;
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @return array
+	 * @throws AppConfigUnknownKeyException if config key is not known in database
+	 * @since 29.0.0
+	 */
+	public function getDetails(string $app, string $key): array {
+		$this->assertParams($app, $key);
+		$this->loadConfigAll();
+		$lazy = $this->isLazy($app, $key);
+
+		if ($lazy) {
+			$cache = $this->lazyCache;
 		} else {
-			$appIds = $this->getApps();
-			$values = array_map(function ($appId) use ($key) {
-				return $this->cache[$appId][$key] ?? null;
-			}, $appIds);
-			$result = array_combine($appIds, $values);
+			$cache = $this->fastCache;
+		}
 
-			return array_filter($result);
+		$type = $this->getValueType($app, $key);
+		try {
+			$typeString = $this->convertTypeToString($type);
+		} catch (AppConfigIncorrectTypeException $e) {
+			$this->logger->warning('type stored in database is not correct', ['exception' => $e, 'type' => $type]);
+			$typeString = (string)$type;
 		}
+
+		return [
+			'app' => $app,
+			'key' => $key,
+			'value' => $cache[$app][$key] ?? throw new AppConfigUnknownKeyException('unknown config key'),
+			'type' => $type,
+			'lazy' => $lazy,
+			'typeString' => $typeString,
+			'sensitive' => $this->isSensitive($app, $key, null)
+		];
 	}
 
 	/**
-	 * get all values of the app or and filters out sensitive data
+	 * @param string $type
+	 *
+	 * @return int
+	 * @throws AppConfigIncorrectTypeException
+	 * @since 29.0.0
+	 */
+	public function convertTypeToInt(string $type): int {
+		return match (strtolower($type)) {
+			'mixed' => IAppConfig::VALUE_MIXED,
+			'string' => IAppConfig::VALUE_STRING,
+			'integer' => IAppConfig::VALUE_INT,
+			'float' => IAppConfig::VALUE_FLOAT,
+			'boolean' => IAppConfig::VALUE_BOOL,
+			'array' => IAppConfig::VALUE_ARRAY,
+			default => throw new AppConfigIncorrectTypeException('Unknown type ' . $type)
+		};
+	}
+
+	/**
+	 * @param int $type
+	 *
+	 * @return string
+	 * @throws AppConfigIncorrectTypeException
+	 * @since 29.0.0
+	 */
+	public function convertTypeToString(int $type): string {
+		$type &= ~self::VALUE_SENSITIVE;
+
+		return match ($type) {
+			IAppConfig::VALUE_MIXED => 'mixed',
+			IAppConfig::VALUE_STRING => 'string',
+			IAppConfig::VALUE_INT => 'integer',
+			IAppConfig::VALUE_FLOAT => 'float',
+			IAppConfig::VALUE_BOOL => 'boolean',
+			IAppConfig::VALUE_ARRAY => 'array',
+			default => throw new AppConfigIncorrectTypeException('Unknown numeric type ' . $type)
+		};
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @since 29.0.0
+	 */
+	public function deleteKey(string $app, string $key): void {
+		$this->assertParams($app, $key);
+		$qb = $this->connection->getQueryBuilder();
+		$qb->delete('appconfig')
+		   ->where($qb->expr()->eq('appid', $qb->createNamedParameter($app)))
+		   ->andWhere($qb->expr()->eq('configkey', $qb->createNamedParameter($key)));
+		$qb->executeStatement();
+
+		unset($this->lazyCache[$app][$key]);
+		unset($this->fastCache[$app][$key]);
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param string $app id of the app
+	 *
+	 * @since 29.0.0
+	 */
+	public function deleteApp(string $app): void {
+		$this->assertParams($app);
+		$qb = $this->connection->getQueryBuilder();
+		$qb->delete('appconfig')
+		   ->where($qb->expr()->eq('appid', $qb->createNamedParameter($app)));
+		$qb->executeStatement();
+
+		$this->clearCache();
+	}
+
+	/**
+	 * @inheritDoc
+	 *
+	 * @param bool $reload set to TRUE to refill cache instantly after clearing it
+	 *
+	 * @since 29.0.0
+	 */
+	public function clearCache(bool $reload = false): void {
+		$this->lazyLoaded = $this->fastLoaded = false;
+		$this->lazyCache = $this->fastCache = $this->valueTypes = [];
+
+		if (!$reload) {
+			return;
+		}
+
+		$this->loadConfigAll();
+	}
+
+
+	/**
+	 * For debug purpose.
+	 * Returns the cached data.
 	 *
-	 * @param string $app
 	 * @return array
+	 * @since 29.0.0
+	 * @internal
 	 */
-	public function getFilteredValues($app) {
-		$values = $this->getValues($app, false);
+	public function statusCache(): array {
+		return [
+			'fastLoaded' => $this->fastLoaded,
+			'fastCache' => $this->fastCache,
+			'lazyLoaded' => $this->lazyLoaded,
+			'lazyCache' => $this->lazyCache,
+		];
+	}
 
-		if (isset($this->sensitiveValues[$app])) {
-			foreach ($this->sensitiveValues[$app] as $sensitiveKeyExp) {
-				$sensitiveKeys = preg_grep($sensitiveKeyExp, array_keys($values));
-				foreach ($sensitiveKeys as $sensitiveKey) {
-					$values[$sensitiveKey] = IConfig::SENSITIVE_VALUE;
-				}
+	/**
+	 * @param int $needle bitflag to search
+	 * @param int $type known value
+	 *
+	 * @return bool TRUE if bitflag $needle is set in $type
+	 */
+	private function isTyped(int $needle, int $type): bool {
+		return (($needle & $type) !== 0);
+	}
+
+	/**
+	 * Confirm the string set for app and key fit the database description
+	 *
+	 * @param string $app assert $app fit in database
+	 * @param string $configKey assert config key fit in database
+	 * @param bool $allowEmptyApp $app can be empty string
+	 * @param int $valueType assert value type is only one type
+	 *
+	 * @throws InvalidArgumentException
+	 */
+	private function assertParams(string $app = '', string $configKey = '', bool $allowEmptyApp = false, int $valueType = -1): void {
+		if (!$allowEmptyApp && $app === '') {
+			throw new InvalidArgumentException('app cannot be an empty string');
+		}
+		if (strlen($app) > self::APP_MAX_LENGTH) {
+			throw new InvalidArgumentException(
+				'Value (' . $app . ') for app is too long (' . self::APP_MAX_LENGTH . ')'
+			);
+		}
+		if (strlen($configKey) > self::KEY_MAX_LENGTH) {
+			throw new InvalidArgumentException('Value (' . $configKey . ') for key is too long (' . self::KEY_MAX_LENGTH . ')');
+		}
+		if ($valueType > -1) {
+			$valueType &= ~self::VALUE_SENSITIVE;
+			if (!in_array($valueType, [self::VALUE_MIXED, self::VALUE_STRING, self::VALUE_INT, self::VALUE_FLOAT, self::VALUE_BOOL, self::VALUE_ARRAY])) {
+				throw new InvalidArgumentException('Unknown value type');
 			}
 		}
+	}
 
-		return $values;
+	private function loadConfigAll(): void {
+		$this->loadConfig(null);
 	}
 
 	/**
-	 * Load all the app config values
+	 * Load normal config or config set as lazy loaded
+	 *
+	 * @param bool|null $lazy set to TRUE to load config set as lazy loaded, set to NULL to load all config
 	 */
-	protected function loadConfigValues() {
-		if ($this->configLoaded) {
+	private function loadConfig(?bool $lazy = false): void {
+		if ($this->isLoaded($lazy)) {
 			return;
 		}
 
-		$this->cache = [];
+		$qb = $this->connection->getQueryBuilder();
+		$qb->from('appconfig');
 
-		$sql = $this->conn->getQueryBuilder();
-		$sql->select('*')
-			->from('appconfig');
-		$result = $sql->execute();
+		/**
+		 * The use of $this->>migrationCompleted is only needed to manage the
+		 * database during the upgrading process to nc29.
+		 */
+		if (!$this->migrationCompleted) {
+			$qb->select('appid', 'configkey', 'configvalue');
+		} else {
+			$qb->select('appid', 'configkey', 'configvalue', 'type', 'lazy');
+			if ($lazy !== null) {
+				if ($this->connection->getDatabaseProvider() === IDBConnection::PLATFORM_ORACLE) {
+					// Oracle does not like empty string nor false boolean !?
+					if ($lazy) {
+						$qb->where($qb->expr()->eq('lazy', $qb->createNamedParameter('1', IQueryBuilder::PARAM_INT)));
+					} else {
+						$qb->where($qb->expr()->orX(
+							$qb->expr()->isNull('lazy'),
+							$qb->expr()->eq('lazy', $qb->createNamedParameter('0', IQueryBuilder::PARAM_INT))
+						));
+					}
+				} else {
+					$qb->where($qb->expr()->eq('lazy', $qb->createNamedParameter($lazy, IQueryBuilder::PARAM_BOOL)));
+				}
+			}
+		}
+
+		try {
+			$result = $qb->executeQuery();
+		} catch (DBException $e) {
+			/**
+			 * in case of issue with field name, it means that migration is not completed.
+			 * Falling back to a request without select on lazy.
+			 * This whole try/catch and the migrationCompleted variable can be removed in NC30.
+			 */
+			if ($e->getReason() !== DBException::REASON_INVALID_FIELD_NAME) {
+				throw $e;
+			}
+
+			$this->migrationCompleted = false;
+			$this->loadConfig($lazy);
+
+			return;
+		}
 
-		// we are going to store the result in memory anyway
 		$rows = $result->fetchAll();
 		foreach ($rows as $row) {
-			if (!isset($this->cache[$row['appid']])) {
-				$this->cache[(string)$row['appid']] = [];
+			// if migration is not completed, 'lazy' and 'type' does not exist in $row
+			// also on oracle, lazy can be null ...
+			if ($row['lazy'] ?? false) {
+				$cache = &$this->lazyCache;
+			} else {
+				$cache = &$this->fastCache;
 			}
-
-			$this->cache[(string)$row['appid']][(string)$row['configkey']] = (string)$row['configvalue'];
+			$cache[$row['appid']][$row['configkey']] = $row['configvalue'] ?? '';
+			$this->valueTypes[$row['appid']][$row['configkey']] = (int)($row['type'] ?? 0);
 		}
 		$result->closeCursor();
+		$this->setAsLoaded($lazy);
+	}
+
+	/**
+	 * if $lazy is:
+	 *  - false: will returns true if fast config is loaded
+	 *  - true : will returns true if lazy config is loaded
+	 *  - null : will returns true if both config are loaded
+	 *
+	 * @param bool $lazy
+	 *
+	 * @return bool
+	 */
+	private function isLoaded(?bool $lazy): bool {
+		if ($lazy === null) {
+			return $this->lazyLoaded && $this->fastLoaded;
+		}
+
+		return $lazy ? $this->lazyLoaded : $this->fastLoaded;
+	}
+
+	/**
+	 * if $lazy is:
+	 * - false: set fast config as loaded
+	 * - true : set lazy config as loaded
+	 * - null : set both config as loaded
+	 *
+	 * @param bool $lazy
+	 */
+	private function setAsLoaded(?bool $lazy): void {
+		if ($lazy === null) {
+			$this->fastLoaded = true;
+			$this->lazyLoaded = true;
+
+			return;
+		}
 
-		$this->configLoaded = true;
+		if ($lazy) {
+			$this->lazyLoaded = true;
+		} else {
+			$this->fastLoaded = true;
+		}
 	}
 
+	/**
+	 * Gets the config value
+	 *
+	 * @param string $app app
+	 * @param string $key key
+	 * @param string $default = null, default value if the key does not exist
+	 *
+	 * @return string the value or $default
+	 * @deprecated - use getValue*()
+	 *
+	 * This function gets a value from the appconfig table. If the key does
+	 * not exist the default value will be returned
+	 */
+	public function getValue($app, $key, $default = null) {
+		$this->loadConfig();
+
+		return $this->fastCache[$app][$key] ?? $default;
+	}
+
+	/**
+	 * Sets a value. If the key did not exist before it will be created.
+	 *
+	 * @param string $app app
+	 * @param string $key key
+	 * @param string|float|int $value value
+	 *
+	 * @return bool True if the value was inserted or updated, false if the value was the same
+	 * @throws AppConfigTypeConflictException
+	 * @throws AppConfigUnknownKeyException
+	 * @deprecated
+	 */
+	public function setValue($app, $key, $value) {
+		return $this->setTypedValue($app, $key, (string)$value, false, self::VALUE_MIXED);
+	}
+
+
+	/**
+	 * get multiple values, either the app or key can be used as wildcard by setting it to false
+	 *
+	 * @param string|false $app
+	 * @param string|false $key
+	 *
+	 * @return array|false
+	 * @deprecated 29.0.0 use getAllValues()
+	 */
+	public function getValues($app, $key) {
+		if (($app !== false) === ($key !== false)) {
+			return false;
+		}
+
+		$key = ($key === false) ? '' : $key;
+		if (!$app) {
+			return $this->searchValues($key);
+		} else {
+			return $this->getAllValues($app, $key);
+		}
+	}
+
+	/**
+	 * get all values of the app or and filters out sensitive data
+	 *
+	 * @param string $app
+	 *
+	 * @return array
+	 * @deprecated 29.0.0 use getAllValues()
+	 */
+	public function getFilteredValues($app) {
+		return $this->getAllValues($app, filtered: true);
+	}
+
+	/**
+	 * @param string $app
+	 *
+	 * @return string[]
+	 * @deprecated data sensitivity should be set when calling setValue*()
+	 */
+	private function getSensitiveKeys(string $app): array {
+		$sensitiveValues = [
+			'circles' => [
+				'/^key_pairs$/',
+				'/^local_gskey$/',
+			],
+			'external' => [
+				'/^sites$/',
+			],
+			'integration_discourse' => [
+				'/^private_key$/',
+				'/^public_key$/',
+			],
+			'integration_dropbox' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+			],
+			'integration_github' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+			],
+			'integration_gitlab' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+				'/^oauth_instance_url$/',
+			],
+			'integration_google' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+			],
+			'integration_jira' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+				'/^forced_instance_url$/',
+			],
+			'integration_onedrive' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+			],
+			'integration_openproject' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+				'/^oauth_instance_url$/',
+			],
+			'integration_reddit' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+			],
+			'integration_suitecrm' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+				'/^oauth_instance_url$/',
+			],
+			'integration_twitter' => [
+				'/^consumer_key$/',
+				'/^consumer_secret$/',
+				'/^followed_user$/',
+			],
+			'integration_zammad' => [
+				'/^client_id$/',
+				'/^client_secret$/',
+				'/^oauth_instance_url$/',
+			],
+			'notify_push' => [
+				'/^cookie$/',
+			],
+			'serverinfo' => [
+				'/^token$/',
+			],
+			'spreed' => [
+				'/^bridge_bot_password$/',
+				'/^hosted-signaling-server-(.*)$/',
+				'/^recording_servers$/',
+				'/^signaling_servers$/',
+				'/^signaling_ticket_secret$/',
+				'/^signaling_token_privkey_(.*)$/',
+				'/^signaling_token_pubkey_(.*)$/',
+				'/^sip_bridge_dialin_info$/',
+				'/^sip_bridge_shared_secret$/',
+				'/^stun_servers$/',
+				'/^turn_servers$/',
+				'/^turn_server_secret$/',
+			],
+			'support' => [
+				'/^last_response$/',
+				'/^potential_subscription_key$/',
+				'/^subscription_key$/',
+			],
+			'theming' => [
+				'/^imprintUrl$/',
+				'/^privacyUrl$/',
+				'/^slogan$/',
+				'/^url$/',
+			],
+			'user_ldap' => [
+				'/^(s..)?ldap_agent_password$/',
+			],
+			'user_saml' => [
+				'/^idp-x509cert$/',
+			],
+		];
+
+		return $sensitiveValues[$app] ?? [];
+	}
 
 	/**
 	 * Clear all the cached app config values
 	 * New cache will be generated next time a config value is retrieved
+	 *
+	 * @deprecated use {@see clearCache()}
 	 */
 	public function clearCachedConfig(): void {
-		$this->configLoaded = false;
+		$this->clearCache();
 	}
 }
diff --git a/lib/private/SystemConfig.php b/lib/private/SystemConfig.php
index bba74e96490..f63663fbfe3 100644
--- a/lib/private/SystemConfig.php
+++ b/lib/private/SystemConfig.php
@@ -124,11 +124,9 @@ class SystemConfig {
 		],
 	];
 
-	/** @var Config */
-	private $config;
-
-	public function __construct(Config $config) {
-		$this->config = $config;
+	public function __construct(
+		private Config $config,
+	) {
 	}
 
 	/**
diff --git a/lib/private/legacy/OC_App.php b/lib/private/legacy/OC_App.php
index 395c1f44c03..6e4b40b4165 100644
--- a/lib/private/legacy/OC_App.php
+++ b/lib/private/legacy/OC_App.php
@@ -63,6 +63,7 @@ use OCP\App\IAppManager;
 use OCP\App\ManagerEvent;
 use OCP\Authentication\IAlternativeLogin;
 use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IAppConfig;
 use Psr\Container\ContainerExceptionInterface;
 use Psr\Log\LoggerInterface;
 
@@ -730,8 +731,9 @@ class OC_App {
 		static $versions;
 
 		if (!$versions) {
-			$appConfig = \OC::$server->getAppConfig();
-			$versions = $appConfig->getValues(false, 'installed_version');
+			/** @var IAppConfig $appConfig */
+			$appConfig = \OCP\Server::get(IAppConfig::class);
+			$versions = $appConfig->searchValues('installed_version');
 		}
 		return $versions;
 	}
diff --git a/lib/public/Exceptions/AppConfigException.php b/lib/public/Exceptions/AppConfigException.php
new file mode 100644
index 00000000000..73c91d9f018
--- /dev/null
+++ b/lib/public/Exceptions/AppConfigException.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright 2023 Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Exceptions;
+
+use Exception;
+
+/**
+ * @since 29.0.0
+ */
+class AppConfigException extends Exception {
+}
diff --git a/lib/public/Exceptions/AppConfigIncorrectTypeException.php b/lib/public/Exceptions/AppConfigIncorrectTypeException.php
new file mode 100644
index 00000000000..1284e4b193e
--- /dev/null
+++ b/lib/public/Exceptions/AppConfigIncorrectTypeException.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright 2023 Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Exceptions;
+
+/**
+ * @since 29.0.0
+ */
+class AppConfigIncorrectTypeException extends AppConfigException {
+}
diff --git a/lib/public/Exceptions/AppConfigTypeConflictException.php b/lib/public/Exceptions/AppConfigTypeConflictException.php
new file mode 100644
index 00000000000..599fed0cb3b
--- /dev/null
+++ b/lib/public/Exceptions/AppConfigTypeConflictException.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright 2023 Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Exceptions;
+
+/**
+ * @since 29.0.0
+ */
+class AppConfigTypeConflictException extends AppConfigException {
+}
diff --git a/lib/public/Exceptions/AppConfigUnknownKeyException.php b/lib/public/Exceptions/AppConfigUnknownKeyException.php
new file mode 100644
index 00000000000..e2b9d7fd3dc
--- /dev/null
+++ b/lib/public/Exceptions/AppConfigUnknownKeyException.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright 2023 Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Exceptions;
+
+/**
+ * @since 29.0.0
+ */
+class AppConfigUnknownKeyException extends AppConfigException {
+}
diff --git a/lib/public/IAppConfig.php b/lib/public/IAppConfig.php
index cf387a8a44c..9bdeb14b295 100644
--- a/lib/public/IAppConfig.php
+++ b/lib/public/IAppConfig.php
@@ -1,9 +1,12 @@
 <?php
+
+declare(strict_types=1);
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
  *
  * @author Bart Visscher <bartv@thisnet.nl>
  * @author Joas Schilling <coding@schilljs.com>
+ * @author Maxence Lange <maxence@artificial-owl.com>
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Robin McCorkell <robin@mccorkell.me.uk>
@@ -26,28 +29,486 @@
  */
 namespace OCP;
 
+use OCP\Exceptions\AppConfigUnknownKeyException;
+
 /**
  * This class provides an easy way for apps to store config values in the
  * database.
+ *
+ * **Note:** since 29.0.0, it supports **lazy loading**
+ *
+ * ### What is lazy loading ?
+ * In order to avoid loading useless config values into memory for each request,
+ * only non-lazy values are now loaded.
+ *
+ * Once a value that is lazy is requested, all lazy values will be loaded.
+ *
+ * Similarly, some methods from this class are marked with a warning about ignoring
+ * lazy loading. Use them wisely and only on parts of the code that are called
+ * during specific requests or actions to avoid loading the lazy values all the time.
+ *
  * @since 7.0.0
+ * @since 29.0.0 - Supporting types and lazy loading
  */
 interface IAppConfig {
+	/** @since 29.0.0 */
+	public const VALUE_SENSITIVE = 1;
+	/** @since 29.0.0 */
+	public const VALUE_MIXED = 2;
+	/** @since 29.0.0 */
+	public const VALUE_STRING = 4;
+	/** @since 29.0.0 */
+	public const VALUE_INT = 8;
+	/** @since 29.0.0 */
+	public const VALUE_FLOAT = 16;
+	/** @since 29.0.0 */
+	public const VALUE_BOOL = 32;
+	/** @since 29.0.0 */
+	public const VALUE_ARRAY = 64;
+
 	/**
-	 * check if a key is set in the appconfig
-	 * @param string $app
-	 * @param string $key
-	 * @return bool
+	 * Get list of all apps that have at least one config value stored in database
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @return string[] list of app ids
 	 * @since 7.0.0
 	 */
-	public function hasKey($app, $key);
+	public function getApps(): array;
+
+	/**
+	 * Returns all keys stored in database, related to an app.
+	 * Please note that the values are not returned.
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @param string $app id of the app
+	 *
+	 * @return string[] list of stored config keys
+	 * @since 29.0.0
+	 */
+	public function getKeys(string $app): array;
+
+	/**
+	 * Check if a key exists in the list of stored config values.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return bool TRUE if key exists
+	 * @since 29.0.0 Added the $lazy argument
+	 * @since 7.0.0
+	 */
+	public function hasKey(string $app, string $key, ?bool $lazy = false): bool;
+
+	/**
+	 * best way to see if a value is set as sensitive (not displayed in report)
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool|null $lazy search within lazy loaded config
+	 *
+	 * @return bool TRUE if value is sensitive
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @since 29.0.0
+	 */
+	public function isSensitive(string $app, string $key, ?bool $lazy = false): bool;
+
+	/**
+	 * Returns if the config key stored in database is lazy loaded
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @return bool TRUE if config is lazy loaded
+	 * @throws AppConfigUnknownKeyException if config key is not known
+	 * @see IAppConfig for details about lazy loading
+	 * @since 29.0.0
+	 */
+	public function isLazy(string $app, string $key): bool;
+
+	/**
+	 * List all config values from an app with config key starting with $key.
+	 * Returns an array with config key as key, stored value as value.
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config keys prefix to search, can be empty.
+	 * @param bool $filtered filter sensitive config values
+	 *
+	 * @return array<string, string> [configKey => configValue]
+	 * @since 29.0.0
+	 */
+	public function getAllValues(string $app, string $key = '', bool $filtered = false): array;
+
+	/**
+	 * List all apps storing a specific config key and its stored value.
+	 * Returns an array with appId as key, stored value as value.
+	 *
+	 * @param string $key config key
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return array<string, string> [appId => configValue]
+	 * @since 29.0.0
+	 */
+	public function searchValues(string $key, bool $lazy = false): array;
+
+	/**
+	 * Get config value assigned to a config key.
+	 * If config key is not found in database, default value is returned.
+	 * If config key is set as lazy loaded, the $lazy argument needs to be set to TRUE.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return string stored config value or $default if not set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueInt()
+	 * @see getValueFloat()
+	 * @see getValueBool()
+	 * @see getValueArray()
+	 */
+	public function getValueString(string $app, string $key, string $default = '', bool $lazy = false): string;
+
+	/**
+	 * Get config value assigned to a config key.
+	 * If config key is not found in database, default value is returned.
+	 * If config key is set as lazy loaded, the $lazy argument needs to be set to TRUE.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param int $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return int stored config value or $default if not set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueString()
+	 * @see getValueFloat()
+	 * @see getValueBool()
+	 * @see getValueArray()
+	 */
+	public function getValueInt(string $app, string $key, int $default = 0, bool $lazy = false): int;
+
+	/**
+	 * Get config value assigned to a config key.
+	 * If config key is not found in database, default value is returned.
+	 * If config key is set as lazy loaded, the $lazy argument needs to be set to TRUE.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param float $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return float stored config value or $default if not set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueString()
+	 * @see getValueInt()
+	 * @see getValueBool()
+	 * @see getValueArray()
+	 */
+	public function getValueFloat(string $app, string $key, float $default = 0, bool $lazy = false): float;
+
+	/**
+	 * Get config value assigned to a config key.
+	 * If config key is not found in database, default value is returned.
+	 * If config key is set as lazy loaded, the $lazy argument needs to be set to TRUE.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return bool stored config value or $default if not set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueString()
+	 * @see getValueInt()
+	 * @see getValueFloat()
+	 * @see getValueArray()
+	 */
+	public function getValueBool(string $app, string $key, bool $default = false, bool $lazy = false): bool;
+
+	/**
+	 * Get config value assigned to a config key.
+	 * If config key is not found in database, default value is returned.
+	 * If config key is set as lazy loaded, the $lazy argument needs to be set to TRUE.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param array $default default value
+	 * @param bool $lazy search within lazy loaded config
+	 *
+	 * @return array stored config value or $default if not set in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see getValueString()
+	 * @see getValueInt()
+	 * @see getValueFloat()
+	 * @see getValueBool()
+	 */
+	public function getValueArray(string $app, string $key, array $default = [], bool $lazy = false): array;
+
+	/**
+	 * returns the type of config value
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @return int
+	 * @throws AppConfigUnknownKeyException
+	 * @since 29.0.0
+	 * @see VALUE_STRING
+	 * @see VALUE_INT
+	 * @see VALUE_FLOAT
+	 * @see VALUE_BOOL
+	 * @see VALUE_ARRAY
+	 */
+	public function getValueType(string $app, string $key): int;
+
+	/**
+	 * Store a config key and its value in database
+	 *
+	 * If config key is already known with the exact same config value, the database is not updated.
+	 * If config key is not supposed to be read during the boot of the cloud, it is advised to set it as lazy loaded.
+	 *
+	 * If config value was previously stored as sensitive or lazy loaded, status cannot be altered without using {@see deleteKey()} first
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param string $value config value
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueInt()
+	 * @see setValueFloat()
+	 * @see setValueBool()
+	 * @see setValueArray()
+	 */
+	public function setValueString(string $app, string $key, string $value, bool $lazy = false, bool $sensitive = false): bool;
+
+	/**
+	 * Store a config key and its value in database
+	 *
+	 * When handling huge value around and/or above 2,147,483,647, a debug log will be generated
+	 * on 64bits system, as php int type reach its limit (and throw an exception) on 32bits when using huge numbers.
+	 *
+	 * When using huge numbers, it is advised to use {@see \OCP\Util::numericToNumber()} and {@see setValueString()}
+	 *
+	 * If config key is already known with the exact same config value, the database is not updated.
+	 * If config key is not supposed to be read during the boot of the cloud, it is advised to set it as lazy loaded.
+	 *
+	 * If config value was previously stored as sensitive or lazy loaded, status cannot be altered without using {@see deleteKey()} first
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param int $value config value
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueString()
+	 * @see setValueFloat()
+	 * @see setValueBool()
+	 * @see setValueArray()
+	 */
+	public function setValueInt(string $app, string $key, int $value, bool $lazy = false, bool $sensitive = false): bool;
+
+	/**
+	 * Store a config key and its value in database.
+	 *
+	 * If config key is already known with the exact same config value, the database is not updated.
+	 * If config key is not supposed to be read during the boot of the cloud, it is advised to set it as lazy loaded.
+	 *
+	 * If config value was previously stored as sensitive or lazy loaded, status cannot be altered without using {@see deleteKey()} first
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param float $value config value
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueString()
+	 * @see setValueInt()
+	 * @see setValueBool()
+	 * @see setValueArray()
+	 */
+	public function setValueFloat(string $app, string $key, float $value, bool $lazy = false, bool $sensitive = false): bool;
+
+	/**
+	 * Store a config key and its value in database
+	 *
+	 * If config key is already known with the exact same config value, the database is not updated.
+	 * If config key is not supposed to be read during the boot of the cloud, it is advised to set it as lazy loaded.
+	 *
+	 * If config value was previously stored as lazy loaded, status cannot be altered without using {@see deleteKey()} first
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $value config value
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueString()
+	 * @see setValueInt()
+	 * @see setValueFloat()
+	 * @see setValueArray()
+	 */
+	public function setValueBool(string $app, string $key, bool $value, bool $lazy = false): bool;
+
+	/**
+	 * Store a config key and its value in database
+	 *
+	 * If config key is already known with the exact same config value, the database is not updated.
+	 * If config key is not supposed to be read during the boot of the cloud, it is advised to set it as lazy loaded.
+	 *
+	 * If config value was previously stored as sensitive or lazy loaded, status cannot be altered without using {@see deleteKey()} first
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param array $value config value
+	 * @param bool $sensitive if TRUE value will be hidden when listing config values.
+	 * @param bool $lazy set config as lazy loaded
+	 *
+	 * @return bool TRUE if value was different, therefor updated in database
+	 * @since 29.0.0
+	 * @see IAppConfig for explanation about lazy loading
+	 * @see setValueString()
+	 * @see setValueInt()
+	 * @see setValueFloat()
+	 * @see setValueBool()
+	 */
+	public function setValueArray(string $app, string $key, array $value, bool $lazy = false, bool $sensitive = false): bool;
+
+	/**
+	 * switch sensitive status of a config value
+	 *
+	 * **WARNING:** ignore lazy filtering, all config values are loaded from database
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $sensitive TRUE to set as sensitive, FALSE to unset
+	 *
+	 * @return bool TRUE if database update were necessary
+	 * @since 29.0.0
+	 */
+	public function updateSensitive(string $app, string $key, bool $sensitive): bool;
+
+	/**
+	 * switch lazy loading status of a config value
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @param bool $lazy TRUE to set as lazy loaded, FALSE to unset
+	 *
+	 * @return bool TRUE if database update was necessary
+	 * @since 29.0.0
+	 */
+	public function updateLazy(string $app, string $key, bool $lazy): bool;
+
+	/**
+	 * returns an array contains details about a config value
+	 *
+	 * ```
+	 * [
+	 *   "app" => "myapp",
+	 *   "key" => "mykey",
+	 *   "value" => "its_value",
+	 *   "lazy" => false,
+	 *   "type" => 4,
+	 *   "typeString" => "string",
+	 *   'sensitive' => true
+	 * ]
+	 * ```
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 *
+	 * @return array
+	 * @throws AppConfigUnknownKeyException if config key is not known in database
+	 * @since 29.0.0
+	 */
+	public function getDetails(string $app, string $key): array;
+
+	/**
+	 * Convert string like 'string', 'integer', 'float', 'bool' or 'array' to
+	 * to bitflag {@see VALUE_STRING}, {@see VALUE_INT}, {@see VALUE_FLOAT},
+	 * {@see VALUE_BOOL} and {@see VALUE_ARRAY}
+	 *
+	 * @param string $type
+	 *
+	 * @return int
+	 * @since 29.0.0
+	 */
+	public function convertTypeToInt(string $type): int;
+
+	/**
+	 * Convert bitflag {@see VALUE_STRING}, {@see VALUE_INT}, {@see VALUE_FLOAT},
+	 * {@see VALUE_BOOL} and {@see VALUE_ARRAY} to human-readable string
+	 *
+	 * @param int $type
+	 *
+	 * @return string
+	 * @since 29.0.0
+	 */
+	public function convertTypeToString(int $type): string;
+
+	/**
+	 * Delete single config key from database.
+	 *
+	 * @param string $app id of the app
+	 * @param string $key config key
+	 * @since 29.0.0
+	 */
+	public function deleteKey(string $app, string $key): void;
+
+	/**
+	 * delete all config keys linked to an app
+	 *
+	 * @param string $app id of the app
+	 * @since 29.0.0
+	 */
+	public function deleteApp(string $app): void;
+
+	/**
+	 * Clear the cache.
+	 *
+	 * The cache will be rebuilt only the next time a config value is requested.
+	 *
+	 * @param bool $reload set to TRUE to refill cache instantly after clearing it
+	 * @since 29.0.0
+	 */
+	public function clearCache(bool $reload = false): void;
 
 	/**
 	 * get multiply values, either the app or key can be used as wildcard by setting it to false
 	 *
 	 * @param string|false $key
 	 * @param string|false $app
+	 *
 	 * @return array|false
 	 * @since 7.0.0
+	 * @deprecated 29.0.0 Use {@see getAllValues()} or {@see searchValues()}
 	 */
 	public function getValues($app, $key);
 
@@ -55,18 +516,10 @@ interface IAppConfig {
 	 * get all values of the app or and filters out sensitive data
 	 *
 	 * @param string $app
+	 *
 	 * @return array
 	 * @since 12.0.0
+	 * @deprecated 29.0.0 Use {@see getAllValues()} or {@see searchValues()}
 	 */
 	public function getFilteredValues($app);
-
-	/**
-	 * Get all apps using the config
-	 * @return string[] an array of app ids
-	 *
-	 * This function returns a list of all apps that have at least one
-	 * entry in the appconfig table.
-	 * @since 7.0.0
-	 */
-	public function getApps();
 }
diff --git a/lib/public/IConfig.php b/lib/public/IConfig.php
index 0e7a7523218..706e4776221 100644
--- a/lib/public/IConfig.php
+++ b/lib/public/IConfig.php
@@ -126,6 +126,7 @@ interface IConfig {
 	 * @param string $appName the appName that we stored the value under
 	 * @return string[] the keys stored for the app
 	 * @since 8.0.0
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function getAppKeys($appName);
 
@@ -137,6 +138,7 @@ interface IConfig {
 	 * @param string $value the value that should be stored
 	 * @return void
 	 * @since 6.0.0
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function setAppValue($appName, $key, $value);
 
@@ -146,8 +148,10 @@ interface IConfig {
 	 * @param string $appName the appName that we stored the value under
 	 * @param string $key the key of the value, under which it was saved
 	 * @param string $default the default value to be returned if the value isn't set
+	 *
 	 * @return string the saved value
 	 * @since 6.0.0 - parameter $default was added in 7.0.0
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function getAppValue($appName, $key, $default = '');
 
@@ -157,6 +161,7 @@ interface IConfig {
 	 * @param string $appName the appName that we stored the value under
 	 * @param string $key the key of the value, under which it was saved
 	 * @since 8.0.0
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function deleteAppValue($appName, $key);
 
@@ -165,6 +170,7 @@ interface IConfig {
 	 *
 	 * @param string $appName the appName the configs are stored under
 	 * @since 8.0.0
+	 * @deprecated 29.0.0 Use {@see IAppConfig} directly
 	 */
 	public function deleteAppValues($appName);