feat(cardav): support result truncation for addressbook federation

Signed-off-by: Hamza Mahjoubi <hamzamahjoubi221@gmail.com>

apps/dav/appinfo/v1/carddav.php

@@ -63,6 +63,7 @@ $cardDavBackend = new CardDavBackend(
 	Server::get(IUserManager::class),
 	Server::get(IEventDispatcher::class),
 	Server::get(\OCA\DAV\CardDAV\Sharing\Backend::class),
+	Server::get(IConfig::class),
 );
 
 $debugging = Server::get(IConfig::class)->getSystemValue('debug', false);

apps/dav/lib/CardDAV/AddressBook.php

@@ -8,7 +8,6 @@
 namespace OCA\DAV\CardDAV;
 
 use OCA\DAV\DAV\Sharing\IShareable;
-use OCA\DAV\Exception\UnsupportedLimitOnInitialSyncException;
 use OCP\DB\Exception;
 use OCP\IL10N;
 use OCP\Server;
@@ -234,9 +233,6 @@ class AddressBook extends \Sabre\CardDAV\AddressBook implements IShareable, IMov
 	}
 
 	public function getChanges($syncToken, $syncLevel, $limit = null) {
-		if (!$syncToken && $limit) {
-			throw new UnsupportedLimitOnInitialSyncException();
-		}
 
 		return parent::getChanges($syncToken, $syncLevel, $limit);
 	}

apps/dav/lib/CardDAV/CardDavBackend.php

@@ -23,6 +23,7 @@ use OCP\AppFramework\Db\TTransactional;
 use OCP\DB\Exception;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IConfig;
 use OCP\IDBConnection;
 use OCP\IUserManager;
 use PDO;
@@ -59,6 +60,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 		private IUserManager $userManager,
 		private IEventDispatcher $dispatcher,
 		private Sharing\Backend $sharingBackend,
+		private IConfig $config,
 	) {
 	}
 
@@ -851,6 +853,8 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 	 * @return array
 	 */
 	public function getChangesForAddressBook($addressBookId, $syncToken, $syncLevel, $limit = null) {
+		$maxLimit = $this->config->getSystemValueInt('carddav_sync_request_truncation', 2500);
+		$limit = ($limit === null) ? $maxLimit : min($limit, $maxLimit);
 		// Current synctoken
 		return $this->atomic(function () use ($addressBookId, $syncToken, $syncLevel, $limit) {
 			$qb = $this->db->getQueryBuilder();
@@ -873,10 +877,35 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 				'modified' => [],
 				'deleted' => [],
 			];
-
-			if ($syncToken) {
+			if (str_starts_with($syncToken, 'init_')) {
+				$syncValues = explode('_', $syncToken);
+				$lastID = $syncValues[1];
+				$initialSyncToken = $syncValues[2];
 				$qb = $this->db->getQueryBuilder();
-				$qb->select('uri', 'operation')
+				$qb->select('id', 'uri')
+					->from('cards')
+					->where(
+						$qb->expr()->andX(
+							$qb->expr()->eq('addressbookid', $qb->createNamedParameter($addressBookId)),
+							$qb->expr()->gt('id', $qb->createNamedParameter($lastID)))
+					)->orderBy('id')
+					->setMaxResults($limit);
+				$stmt = $qb->executeQuery();
+				$values = $stmt->fetchAll(\PDO::FETCH_ASSOC);
+				$stmt->closeCursor();
+				if (count($values) === 0) {
+					$result['syncToken'] = $initialSyncToken;
+					$result['result_truncated'] = false;
+					$result['added'] = [];
+				} else {
+					$lastID = $values[array_key_last($values)]['id'];
+					$result['added'] = array_column($values, 'uri');
+					$result['syncToken'] = count($result['added']) >= $limit ? "init_{$lastID}_$initialSyncToken" : $initialSyncToken ;
+					$result['result_truncated'] = count($result['added']) >= $limit;
+				}
+			} elseif ($syncToken) {
+				$qb = $this->db->getQueryBuilder();
+				$qb->select('uri', 'operation', 'synctoken')
 					->from('addressbookchanges')
 					->where(
 						$qb->expr()->andX(
@@ -886,7 +915,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 						)
 					)->orderBy('synctoken');
 
-				if (is_int($limit) && $limit > 0) {
+				if ($limit > 0) {
 					$qb->setMaxResults($limit);
 				}
 
@@ -899,8 +928,15 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 				// last change on a node is relevant.
 				while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
 					$changes[$row['uri']] = $row['operation'];
+					// get the last synctoken, needed in case a limit was set
+					$result['syncToken'] = $row['synctoken'];
 				}
 				$stmt->closeCursor();
+				
+				// No changes found, use current token
+				if (empty($changes)) {
+					$result['syncToken'] = $currentToken;
+				}
 
 				foreach ($changes as $uri => $operation) {
 					switch ($operation) {
@@ -917,14 +953,27 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 				}
 			} else {
 				$qb = $this->db->getQueryBuilder();
-				$qb->select('uri')
+				$qb->select('id', 'uri')
 					->from('cards')
 					->where(
 						$qb->expr()->eq('addressbookid', $qb->createNamedParameter($addressBookId))
 					);
 				// No synctoken supplied, this is the initial sync.
+				$qb->setMaxResults($limit);
 				$stmt = $qb->executeQuery();
-				$result['added'] = $stmt->fetchAll(\PDO::FETCH_COLUMN);
+				$values = $stmt->fetchAll(\PDO::FETCH_ASSOC);
+				if (empty($values)) {
+					$result['added'] = [];
+					return $result;
+				}
+				$lastID = $values[array_key_last($values)]['id'];
+				if (count($values) >= $limit) {
+					$result['syncToken'] = 'init_' . $lastID . '_' . $currentToken;
+					$result['result_truncated'] = true;
+				}
+
+				$result['added'] = array_column($values, 'uri');
+
 				$stmt->closeCursor();
 			}
 			return $result;

apps/dav/lib/CardDAV/SystemAddressbook.php

@@ -8,7 +8,6 @@ declare(strict_types=1);
  */
 namespace OCA\DAV\CardDAV;
 
-use OCA\DAV\Exception\UnsupportedLimitOnInitialSyncException;
 use OCA\Federation\TrustedServers;
 use OCP\Accounts\IAccountManager;
 use OCP\IConfig;
@@ -212,14 +211,7 @@ class SystemAddressbook extends AddressBook {
 		}
 		return new Card($this->carddavBackend, $this->addressBookInfo, $obj);
 	}
-
-	/**
-	 * @throws UnsupportedLimitOnInitialSyncException
-	 */
 	public function getChanges($syncToken, $syncLevel, $limit = null) {
-		if (!$syncToken && $limit) {
-			throw new UnsupportedLimitOnInitialSyncException();
-		}
 
 		if (!$this->carddavBackend instanceof SyncSupport) {
 			return null;

apps/dav/lib/RootCollection.php

@@ -132,6 +132,7 @@ class RootCollection extends SimpleCollection {
 		);
 
 		$contactsSharingBackend = Server::get(\OCA\DAV\CardDAV\Sharing\Backend::class);
+		$config = Server::get(IConfig::class);
 
 		$pluginManager = new PluginManager(\OC::$server, Server::get(IAppManager::class));
 		$usersCardDavBackend = new CardDavBackend(
@@ -140,6 +141,7 @@ class RootCollection extends SimpleCollection {
 			$userManager,
 			$dispatcher,
 			$contactsSharingBackend,
+			$config
 		);
 		$usersAddressBookRoot = new AddressBookRoot($userPrincipalBackend, $usersCardDavBackend, $pluginManager, $userSession->getUser(), $groupManager, 'principals/users');
 		$usersAddressBookRoot->disableListing = $disableListing;
@@ -150,6 +152,7 @@ class RootCollection extends SimpleCollection {
 			$userManager,
 			$dispatcher,
 			$contactsSharingBackend,
+			$config
 		);
 		$systemAddressBookRoot = new AddressBookRoot(new SystemPrincipalBackend(), $systemCardDavBackend, $pluginManager, $userSession->getUser(), $groupManager, 'principals/system');
 		$systemAddressBookRoot->disableListing = $disableListing;

apps/dav/tests/unit/CardDAV/CardDavBackendTest.php

@@ -50,6 +50,7 @@ class CardDavBackendTest extends TestCase {
 	private IUserManager&MockObject $userManager;
 	private IGroupManager&MockObject $groupManager;
 	private IEventDispatcher&MockObject $dispatcher;
+	private IConfig&MockObject $config;
 	private Backend $sharingBackend;
 	private IDBConnection $db;
 	private CardDavBackend $backend;
@@ -96,6 +97,7 @@ class CardDavBackendTest extends TestCase {
 
 		$this->userManager = $this->createMock(IUserManager::class);
 		$this->groupManager = $this->createMock(IGroupManager::class);
+		$this->config = $this->createMock(IConfig::class);
 		$this->principal = $this->getMockBuilder(Principal::class)
 			->setConstructorArgs([
 				$this->userManager,
@@ -106,7 +108,7 @@ class CardDavBackendTest extends TestCase {
 				$this->createMock(IAppManager::class),
 				$this->createMock(ProxyMapper::class),
 				$this->createMock(KnownUserService::class),
-				$this->createMock(IConfig::class),
+				$this->config,
 				$this->createMock(IFactory::class)
 			])
 			->onlyMethods(['getPrincipalByPath', 'getGroupMembership', 'findByUri'])
@@ -135,6 +137,7 @@ class CardDavBackendTest extends TestCase {
 			$this->userManager,
 			$this->dispatcher,
 			$this->sharingBackend,
+			$this->config,
 		);
 		// start every test with a empty cards_properties and cards table
 		$query = $this->db->getQueryBuilder();
@@ -231,7 +234,7 @@ class CardDavBackendTest extends TestCase {
 	public function testCardOperations(): void {
 		/** @var CardDavBackend&MockObject $backend */
 		$backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend,$this->config])
 			->onlyMethods(['updateProperties', 'purgeProperties'])
 			->getMock();
 
@@ -291,7 +294,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testMultiCard(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend,$this->config])
 			->onlyMethods(['updateProperties'])
 			->getMock();
 
@@ -345,7 +348,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testMultipleUIDOnDifferentAddressbooks(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend,$this->config])
 			->onlyMethods(['updateProperties'])
 			->getMock();
 
@@ -368,7 +371,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testMultipleUIDDenied(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend, $this->config])
 			->onlyMethods(['updateProperties'])
 			->getMock();
 
@@ -390,7 +393,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testNoValidUID(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend, $this->config])
 			->onlyMethods(['updateProperties'])
 			->getMock();
 
@@ -408,7 +411,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testDeleteWithoutCard(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend, $this->config])
 			->onlyMethods([
 				'getCardId',
 				'addChange',
@@ -453,7 +456,7 @@ class CardDavBackendTest extends TestCase {
 
 	public function testSyncSupport(): void {
 		$this->backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend, $this->config])
 			->onlyMethods(['updateProperties'])
 			->getMock();
 
@@ -522,7 +525,7 @@ class CardDavBackendTest extends TestCase {
 		$cardId = 2;
 
 		$backend = $this->getMockBuilder(CardDavBackend::class)
-			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend])
+			->setConstructorArgs([$this->db, $this->principal, $this->userManager, $this->dispatcher, $this->sharingBackend, $this->config])
 			->onlyMethods(['getCardId'])->getMock();
 
 		$backend->expects($this->any())->method('getCardId')->willReturn($cardId);

apps/dav/tests/unit/CardDAV/SyncServiceTest.php

@@ -108,7 +108,7 @@ class SyncServiceTest extends TestCase {
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 
 		$this->assertEquals('http://sabre.io/ns/sync/1', $token);
 	}
@@ -179,7 +179,7 @@ END:VCARD';
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 
 		$this->assertEquals('http://sabre.io/ns/sync/2', $token);
 	}
@@ -250,7 +250,7 @@ END:VCARD';
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 
 		$this->assertEquals('http://sabre.io/ns/sync/3', $token);
 	}
@@ -291,7 +291,7 @@ END:VCARD';
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 
 		$this->assertEquals('http://sabre.io/ns/sync/4', $token);
 	}
@@ -422,7 +422,7 @@ END:VCARD';
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 	}
 
 	#[\PHPUnit\Framework\Attributes\DataProvider('providerUseAbsoluteUriReport')]
@@ -462,7 +462,7 @@ END:VCARD';
 			'1',
 			'principals/system/system',
 			[]
-		);
+		)['token'];
 	}
 
 	public static function providerUseAbsoluteUriReport(): array {

apps/federation/lib/SyncFederationAddressBooks.php

@@ -52,6 +52,12 @@ class SyncFederationAddressBooks {
 			try {
 				$newToken = $this->syncService->syncRemoteAddressBook($url, $cardDavUser, $addressBookUrl, $sharedSecret, $syncToken, $targetBookId, $targetPrincipal, $targetBookProperties);
 				if ($newToken !== $syncToken) {
+					// Finish truncated initial sync.
+					if (strpos($newToken, 'init') !== false) {
+						do {
+							$newToken = $this->syncService->syncRemoteAddressBook($url, $cardDavUser, $addressBookUrl, $sharedSecret, $syncToken, $targetBookId, $targetPrincipal, $targetBookProperties);
+						} while (str_contains($newToken, 'init_'));
+					}
 					$this->dbHandler->setServerStatus($url, TrustedServers::STATUS_OK, $newToken);
 				} else {
 					$this->logger->debug("Sync Token for $url unchanged from previous sync");

config/config.sample.php

@@ -354,6 +354,11 @@ $CONFIG = [
  */
 'carddav_sync_request_timeout' => 30,
 
+/**
+ * The limit applied to the synchronization report request, e.g. federated system address books (as run by `occ federation:sync-addressbooks`).
+ */
+'carddav_sync_request_truncation' => 2500,
+
 /**
  * `true` enables a relaxed session timeout, where the session timeout would no longer be
  * handled by Nextcloud but by either the PHP garbage collection or the expiration of