perf(dav): avoid repeated stack lookups for object etags

Signed-off-by: Jaggob <37583151+Jaggob@users.noreply.github.com>

Author: Jaggob

lib/DAV/CalendarObject.php

@@ -81,7 +81,11 @@ public function getContentType() {
 	}
 
 	public function getETag() {
-		return '"' . md5($this->sourceItem->getLastModified() . '|' . $this->backend->getObjectRevisionFingerprint($this->sourceItem)) . '"';
+		return '"' . md5($this->sourceItem->getLastModified() . '|' . $this->backend->getObjectRevisionFingerprint(
+			$this->sourceItem,
+			$this->calendar->getBoardId(),
+			$this->calendar->getStackId()
+		)) . '"';
 	}
 
 	public function getSize() {

lib/DAV/DeckCalendarBackend.php

@@ -192,21 +192,32 @@ public function getCalendarRevisionFingerprint(int $boardId, ?int $stackId = nul
 	/**
 	 * @param Card|Stack $sourceItem
 	 */
-	public function getObjectRevisionFingerprint($sourceItem): string {
+	public function getObjectRevisionFingerprint($sourceItem, ?int $boardId = null, ?int $calendarStackId = null): string {
 		$mode = $this->configService->getCalDavListMode();
 		if (!($sourceItem instanceof Card)) {
 			return $mode;
 		}
 
-		try {
-			$stack = $this->stackService->find($sourceItem->getStackId());
-			$boardId = $stack->getBoardId();
-		} catch (\Throwable $e) {
-			return $mode;
+		$stackId = $calendarStackId ?? $sourceItem->getStackId();
+		$stack = null;
+
+		if ($mode === ConfigService::SETTING_CALDAV_LIST_MODE_LIST_AS_CATEGORY || $boardId === null) {
+			try {
+				$stack = $this->stackService->find($sourceItem->getStackId());
+				$boardId ??= $stack->getBoardId();
+				$stackId = $stack->getId();
+			} catch (\Throwable $e) {
+				return $mode;
+			}
 		}
 
-		$fingerprint = [$mode, 'stack:' . $stack->getId()];
+		$fingerprint = [$mode, 'stack:' . $stackId];
 		if ($mode === ConfigService::SETTING_CALDAV_LIST_MODE_LIST_AS_CATEGORY) {
+			try {
+				$stack ??= $this->stackService->find($sourceItem->getStackId());
+			} catch (\Throwable $e) {
+				return $mode;
+			}
 			$fingerprint[] = $stack->getTitle();
 			$fingerprint[] = (string)$stack->getDeletedAt();
 		}

tests/unit/DAV/CalendarObjectTest.php

@@ -59,4 +59,25 @@ public function testCardObjectAclKeepsWriteForEditors(): void {
 
 		$this->assertSame($expectedAcl, $calendarObject->getACL());
 	}
+
+	public function testGetETagPassesCalendarContextToBackendFingerprint(): void {
+		$calendar = $this->createMock(Calendar::class);
+		$calendar->method('getBoardId')->willReturn(12);
+		$calendar->method('getStackId')->willReturn(9);
+
+		$backend = $this->createMock(DeckCalendarBackend::class);
+
+		$card = $this->createMock(Card::class);
+		$card->method('getCalendarObject')->willReturn(new VCalendar());
+		$card->method('getLastModified')->willReturn(1234567890);
+
+		$backend->expects($this->once())
+			->method('getObjectRevisionFingerprint')
+			->with($card, 12, 9)
+			->willReturn('fingerprint');
+
+		$calendarObject = new CalendarObject($calendar, 'card-7.ics', $backend, $card);
+
+		$this->assertSame('"' . md5('1234567890|fingerprint') . '"', $calendarObject->getETag());
+	}
 }

tests/unit/DAV/DeckCalendarBackendTest.php

@@ -1091,4 +1091,17 @@ public function testUpdateCardLimitsAutoCreatedLabelsPerSync(): void {
 
 		$this->backend->updateCalendarObject($sourceCard, $calendarData);
 	}
+
+	public function testGetObjectRevisionFingerprintUsesKnownBoardContextWithoutStackLookup(): void {
+		$card = new Card();
+		$card->setId(123);
+		$card->setStackId(42);
+
+		$this->stackService->expects($this->never())
+			->method('find');
+
+		$fingerprint = $this->backend->getObjectRevisionFingerprint($card, 12, 42);
+
+		$this->assertSame(ConfigService::SETTING_CALDAV_LIST_MODE_ROOT_TASKS . '|stack:42', $fingerprint);
+	}
 }