BackgroundTasksHandler::fillPoolSlots()

Complexity

Conditions	17
Paths	92

Size

Total Lines	71
Code Lines	38

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	0

<?php
    private function fillPoolSlots(): void {
        $maxPool = min((int) $this->maxParallelTasks, 2);
        $availableSlots = $maxPool - count($this->pool);
        if ($availableSlots <= 0) return;

        // Don't launch anything while an exclusive task is running
        foreach ($this->pool as $entry) {
            if ($this->isExclusiveTask($entry['task']['process_type'])) {
                return;
            }
        }

        // Collect resource keys of running tasks
        $runningKeys = [];
        foreach ($this->pool as $entry) {
            if ($entry['resourceKey'] !== null) {
                $runningKeys[] = $entry['resourceKey'];
            }
        }

        // Fetch candidate tasks from DB
        $candidates = DB::query(
            'SELECT increment_id, process_type, arguments
            FROM ' . prefixTable('background_tasks') . '
            WHERE is_in_progress = 0
            AND (finished_at IS NULL OR finished_at = "")
            ORDER BY increment_id ASC
            LIMIT %i',
            $this->batchSize
        );

        foreach ($candidates as $task) {
            if ($availableSlots <= 0) break;

            $isExclusive = $this->isExclusiveTask($task['process_type']);
            $resourceKey = $this->getResourceKey($task);

            // Exclusive task: only launch if pool is completely empty
            if ($isExclusive && !empty($this->pool)) {
                continue;
            }

            // Resource key conflict: skip if same key is already running
            if ($resourceKey !== null && in_array($resourceKey, $runningKeys, true)) {
                if (LOG_TASKS === true) $this->logger->log(
                    'Task ' . $task['increment_id'] . ' deferred: resource conflict (' . $resourceKey . ')',
                    'INFO'
                );
                continue;
            }

            // Launch the task
            if (LOG_TASKS === true) $this->logger->log(
                'Launching task ' . $task['increment_id'] . ' (' . $task['process_type'] . ')',
                'INFO'
            );

            $process = $this->launchTask($task);
            if ($process !== null) {
                $this->pool[(int) $task['increment_id']] = [
                    'process' => $process,
                    'task' => $task,
                    'resourceKey' => $resourceKey,
                ];
                if ($resourceKey !== null) {
                    $runningKeys[] = $resourceKey;
                }
                $availableSlots--;

                // If we just launched an exclusive task, stop filling
                if ($isExclusive) break;
            }