feat(TaskProcessingApiController): Add new next_batch endpoint

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

Author: marcelklehr

core/Controller/TaskProcessingApiController.php

@@ -532,29 +532,7 @@ public function cancelTask(int $taskId): DataResponse {
 	#[ApiRoute(verb: 'GET', url: '/tasks_provider/next', root: '/taskprocessing')]
 	public function getNextScheduledTask(array $providerIds, array $taskTypeIds): DataResponse {
 		try {
-			$providerIdsBasedOnTaskTypesWithNull = array_unique(array_map(function ($taskTypeId) {
-				try {
-					return $this->taskProcessingManager->getPreferredProvider($taskTypeId)->getId();
-				} catch (Exception) {
-					return null;
-				}
-			}, $taskTypeIds));
-
-			$providerIdsBasedOnTaskTypes = array_filter($providerIdsBasedOnTaskTypesWithNull, fn ($providerId) => $providerId !== null);
-
-			// restrict $providerIds to providers that are configured as preferred for the passed task types
-			$possibleProviderIds = array_values(array_intersect($providerIdsBasedOnTaskTypes, $providerIds));
-
-			// restrict $taskTypeIds to task types that can actually be run by one of the now restricted providers
-			$possibleTaskTypeIds = array_values(array_filter($taskTypeIds, function ($taskTypeId) use ($possibleProviderIds) {
-				try {
-					$providerForTaskType = $this->taskProcessingManager->getPreferredProvider($taskTypeId)->getId();
-				} catch (Exception) {
-					// no provider found for task type
-					return false;
-				}
-				return in_array($providerForTaskType, $possibleProviderIds, true);
-			}));
+			[$possibleProviderIds, $possibleTaskTypeIds] = $this->intersectTaskTypesAndProviders($taskTypeIds, $providerIds);
 
 			if (count($possibleProviderIds) === 0 || count($possibleTaskTypeIds) === 0) {
 				throw new NotFoundException();
@@ -596,6 +574,73 @@ public function getNextScheduledTask(array $providerIds, array $taskTypeIds): Da
 		}
 	}
 
+	/**
+	 * Returns the next n scheduled tasks for the specified set of taskTypes and providers
+	 *
+	 * @param list<string> $providerIds The ids of the providers
+	 * @param list<string> $taskTypeIds The ids of the task types
+	 * @param int $numberOfTasks The number of tasks to return
+	 * @return DataResponse<Http::STATUS_OK, array{tasks: list<array{task: CoreTaskProcessingTask, provider: string}>, has_more: bool}, array{}>|DataResponse<Http::STATUS_NO_CONTENT, null, array{}>|DataResponse<Http::STATUS_INTERNAL_SERVER_ERROR, array{message: string}, array{}>
+	 *
+	 * 200: Tasks returned
+	 */
+	#[ExAppRequired]
+	#[ApiRoute(verb: 'GET', url: '/tasks_provider/next_batch', root: '/taskprocessing')]
+	public function getNextScheduledTaskBatch(array $providerIds, array $taskTypeIds, int $numberOfTasks = 1): DataResponse {
+		try {
+			[$possibleProviderIds, $possibleTaskTypeIds] = $this->intersectTaskTypesAndProviders($taskTypeIds, $providerIds);
+
+			if (count($possibleProviderIds) === 0 || count($possibleTaskTypeIds) === 0) {
+				return new DataResponse([
+					'tasks' => [],
+					'has_more' => false,
+				]);
+			}
+
+			/** @var list<array{task:CoreTaskProcessingTask, provider:string}> $tasks */
+			$tasks = [];
+			$taskIdsToIgnore = [];
+			// Stop when $numberOfTasks is reached or the json payload is larger than 50MiB
+			while (count($tasks) < $numberOfTasks && strlen(json_encode($tasks)) < 50 * 1024 * 1024) {
+				// Until we find a task whose task type is set to be provided by the providers requested with this request
+				// Or no scheduled task is found anymore (given the taskIds to ignore)
+				try {
+					$task = $this->taskProcessingManager->getNextScheduledTask($possibleTaskTypeIds, $taskIdsToIgnore);
+				} catch (NotFoundException) {
+					break;
+				}
+				try {
+					$provider = $this->taskProcessingManager->getPreferredProvider($task->getTaskTypeId());
+					if (in_array($provider->getId(), $possibleProviderIds, true)) {
+						if ($this->taskProcessingManager->lockTask($task)) {
+							$tasks[] = ['task' => $task->jsonSerialize(), 'provider' => $provider->getId()];
+							continue;
+						}
+					}
+				} catch (Exception) {
+					// There is no provider set for the task type of this task
+					// proceed to ignore this task
+				}
+
+				$taskIdsToIgnore[] = (int)$task->getId();
+			}
+
+			try {
+				$this->taskProcessingManager->getNextScheduledTask($possibleTaskTypeIds, $taskIdsToIgnore);
+				$hasMore = true;
+			} catch (\Throwable) {
+				$hasMore = false;
+			}
+
+			return new DataResponse([
+				'tasks' => $tasks,
+				'has_more' => $hasMore,
+			]);
+		} catch (Exception) {
+			return new DataResponse(['message' => $this->l->t('Internal error')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+	}
+
 	/**
 	 * @param resource $data
 	 * @return int
@@ -611,4 +656,36 @@ private function setFileContentsInternal($data): int {
 		$file = $folder->newFile(time() . '-' . rand(1, 100000), $data);
 		return $file->getId();
 	}
+
+	/**
+	 * @param array $taskTypeIds
+	 * @param array $providerIds
+	 * @return array
+	 */
+	public function intersectTaskTypesAndProviders(array $taskTypeIds, array $providerIds): array {
+		$providerIdsBasedOnTaskTypesWithNull = array_unique(array_map(function ($taskTypeId) {
+			try {
+				return $this->taskProcessingManager->getPreferredProvider($taskTypeId)->getId();
+			} catch (Exception) {
+				return null;
+			}
+		}, $taskTypeIds));
+
+		$providerIdsBasedOnTaskTypes = array_filter($providerIdsBasedOnTaskTypesWithNull, fn ($providerId) => $providerId !== null);
+
+		// restrict $providerIds to providers that are configured as preferred for the passed task types
+		$possibleProviderIds = array_values(array_intersect($providerIdsBasedOnTaskTypes, $providerIds));
+
+		// restrict $taskTypeIds to task types that can actually be run by one of the now restricted providers
+		$possibleTaskTypeIds = array_values(array_filter($taskTypeIds, function ($taskTypeId) use ($possibleProviderIds) {
+			try {
+				$providerForTaskType = $this->taskProcessingManager->getPreferredProvider($taskTypeId)->getId();
+			} catch (Exception) {
+				// no provider found for task type
+				return false;
+			}
+			return in_array($providerForTaskType, $possibleProviderIds, true);
+		}));
+		return [$possibleProviderIds, $possibleTaskTypeIds];
+	}
 }