1. <?php
  3. /**
  4. * API Endpoint Rate Limiter for Scheduled Runs
  5. *
  6. * Reads configuration from a file to define limits and enforces them.
  7. */
  9. class RateLimiter {
  11. private $config;
  12. private $request_counts = []; // Stores request counts per endpoint and user/identifier
  14. public function __construct(string $config_file) {
  15. $this->config = $this->loadConfig($config_file);
  16. }
  18. /**
  19. * Loads the configuration from the specified file.
  20. * @param string $config_file Path to the configuration file.
  21. * @return array|null An associative array containing the configuration data.
  22. */
  23. private function loadConfig(string $config_file): ?array {
  24. if (file_exists($config_file)) {
  25. $config = json_decode(file_get_contents($config_file), true);
  26. if (json_last_error() !== JSON_ERROR_NONE) {
  27. error_log("Error decoding config file: " . json_last_error_msg());
  28. return null;
  29. }
  30. return $config;
  31. } else {
  32. error_log("Config file not found: " . $config_file);
  33. return null;
  34. }
  35. }
  37. /**
  38. * Checks if an API endpoint request is allowed based on the configuration.
  39. * @param string $endpoint The API endpoint being called.
  40. * @param string $user_identifier A unique identifier for the user/system making the request.
  41. * @return bool True if the request is allowed, false otherwise.
  42. */
  43. public function isAllowed(string $endpoint, string $user_identifier): bool {
  44. if (!isset($this->config[$endpoint])) {
  45. // Endpoint not configured, allow unlimited requests.
  46. return true;
  47. }
  49. $limit = $this->config[$endpoint]['limit'];
  50. $window = $this->config[$endpoint]['window'];
  52. if (empty($this->request_counts[$user_identifier][$endpoint])) {
  53. $this->request_counts[$user_identifier][$endpoint] = [
  54. 'count' => 0,
  55. 'last_reset' => time()
  56. ];
  57. }
  59. $current_count = $this->request_counts[$user_identifier][$endpoint]['count'];
  61. if (time() - $this->request_counts[$user_identifier][$endpoint]['last_reset'] > $window) {
  62. $current_count = 0; // Reset count at the beginning of the window
  63. }
  65. if ($current_count < $limit) {
  66. $this->request_counts[$user_identifier][$endpoint]['count']++;
  67. $this->request_counts[$user_identifier][$endpoint]['last_reset'] = time();
  68. return true;
  69. } else {
  70. return false; // Rate limit exceeded
  71. }
  72. }
  74. /**
  75. * Resets the request count for a user and endpoint.
  76. * @param string $user_identifier The identifier of the user.
  77. * @param string $endpoint The API endpoint.
  78. */
  79. public function resetCount(string $user_identifier, string $endpoint): void {
  80. if (isset($this->request_counts[$user_identifier][$endpoint])) {
  81. $this->request_counts[$user_identifier][$endpoint]['count'] = 0;
  82. $this->request_counts[$user_identifier][$endpoint]['last_reset'] = time();
  83. }
  84. }
  85. }
  87. // Example Usage (within your API endpoint handler)
  88. /*
  89. $rateLimiter = new RateLimiter('config.json');
  91. if ($rateLimiter->isAllowed('scheduled_task', 'user123')) {
  92. // Process the API request
  93. echo "Request allowed!";
  94. } else {
  95. // Rate limit exceeded
  96. header('HTTP/1.1 429 Too Many Requests');
  97. echo 'Rate limit exceeded. Please try again later.';
  98. exit;
  99. }
  100. */
  102. ?>

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