1. <?php
  3. class TaskQueue {
  5. private $tasks = [];
  7. public function addTask(string $taskName, callable $taskFunction, array $dependencies = []): bool {
  8. // Basic validation: task name must not be empty
  9. if (empty($taskName)) {
  10. return false;
  11. }
  13. // Store task information
  14. $this->tasks[] = [
  15. 'name' => $taskName,
  16. 'function' => $taskFunction,
  17. 'dependencies' => $dependencies,
  18. 'status' => 'pending'
  19. ];
  20. return true;
  21. }
  23. public function executeTasks(): void {
  24. foreach ($this->tasks as $task) {
  25. if ($this->canExecuteTask($task)) {
  26. $this->executeTask($task);
  27. }
  28. }
  29. }
  31. private function canExecuteTask(array $task): bool {
  32. // Check dependencies
  33. foreach ($task['dependencies'] as $dependencyName) {
  34. $dependency = $this->findTask($dependencyName);
  35. if ($dependency && $dependency['status'] !== 'completed') {
  36. return false; // Dependency not met
  37. }
  38. }
  39. return true;
  40. }
  42. private function executeTask(array $task): void {
  43. // Execute the task
  44. try {
  45. $task['function']();
  46. $task['status'] = 'completed';
  47. echo "Task '$task['name']' executed successfully.\n";
  48. } catch (Exception $e) {
  49. $task['status'] = 'failed';
  50. echo "Error executing task '$task['name']': " . $e->getMessage() . "\n";
  51. }
  52. }
  54. private function findTask(string $taskName): ?array {
  55. foreach ($this->tasks as $task) {
  56. if ($task['name'] === $taskName) {
  57. return $task;
  58. }
  59. }
  60. return null;
  61. }
  62. }
  64. // Example Usage
  65. $taskQueue = new TaskQueue();
  67. // Define some tasks
  68. $taskQueue->addTask('Task1', function () { echo "Executing Task 1...\n"; });
  69. $taskQueue->addTask('Task2', function () { echo "Executing Task 2...\n"; }, ['Task1']);
  70. $taskQueue->addTask('Task3', function () { echo "Executing Task 3...\n"; }, ['Task2']);
  71. $taskQueue->addTask('Task4', function () { echo "Executing Task 4...\n"; });
  76. // Execute the tasks
  77. $taskQueue->executeTasks();
  79. ?>

Add your comment