1. <?php
  3. class HTTPCache {
  5. private $cache = [];
  6. private $rateLimit = 10; // Requests per second
  7. private $lastRequestTime = 0;
  8. private $cacheDuration = 60; //Cache duration in seconds
  9. private $proxy = null; //Optional proxy object
  11. public function __construct($proxy = null) {
  12. $this->proxy = $proxy;
  13. }
  15. /**
  16. * Makes an HTTP request, caching the result.
  17. *
  18. * @param string $url The URL to request.
  19. * @param callable $callback A callback function to execute with the response data.
  20. * @return mixed The result of the callback function.
  21. * @throws Exception If rate limit is exceeded.
  22. */
  23. public function get($url, callable $callback) {
  24. //Check if the request is already in the cache and within the cache duration
  25. if ($this->isCached($url)) {
  26. return $this->cache[$url];
  27. }
  29. // Apply rate limiting
  30. $currentTime = time();
  31. if ($currentTime - $this->lastRequestTime < 1 / $this->rateLimit) {
  32. throw new Exception("Rate limit exceeded.");
  33. }
  34. $this->lastRequestTime = $currentTime;
  36. try {
  37. $response = $this->makeRequest($url);
  38. if ($response) {
  39. $this->cache[$url] = $response;
  40. $this->cacheExpiration($url, $this->cacheDuration);
  41. return $callback($response);
  42. } else {
  43. return null; //Or handle the error as needed. Can return an empty array or similar.
  44. }
  45. } catch (Exception $e) {
  46. //Handle exceptions (e.g., network errors, HTTP errors)
  47. error_log("HTTP Request Error: " . $url . " - " . $e->getMessage());
  48. throw $e; // Re-throw the exception to be handled by the caller.
  49. }
  50. }
  52. /**
  53. * Checks if a URL is in the cache and if it's still valid.
  54. *
  55. * @param string $url The URL to check.
  56. * @return bool True if the URL is in the cache and not expired, false otherwise.
  57. */
  58. private function isCached(string $url): bool {
  59. if (!isset($this->cache[$url])) {
  60. return false;
  61. }
  63. $cacheEntry = $this->cache[$url];
  64. if ($cacheEntry['expiry'] > time()) {
  65. return true;
  66. } else {
  67. $this->deleteCacheEntry($url);
  68. return false;
  69. }
  70. }
  72. /**
  73. * Makes an HTTP request. Uses cURL.
  74. *
  75. * @param string $url The URL to request.
  76. * @return string|null The response body, or null on error.
  77. * @throws Exception If the request fails.
  78. */
  79. private function makeRequest(string $url): ?string {
  80. $ch = $this->proxy ? curl_init($url) : curl_init($url);
  82. if ($ch === false) {
  83. throw new Exception("cURL initialization failed.");
  84. }
  86. curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  87. curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); //Follow redirects
  88. curl_setopt($ch, CURLOPT_TIMEOUT, 10); // Set a timeout
  89. curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // Disable SSL verification (for testing only!)
  91. $response = curl_exec($ch);
  93. if ($response === false) {
  94. $error = curl_error($ch);
  95. throw new Exception("cURL error: " . $error);
  96. }
  98. curl_close($ch);
  99. return $response;
  100. }
  102. /**
  103. * Expires a cache entry.
  104. *
  105. * @param string $url The URL of the cached entry.
  106. * @param int $duration The cache duration in seconds.
  107. */
  108. private function cacheExpiration(string $url, int $duration): void {
  109. $this->cache[$url]['expiry'] = time() + $duration;
  110. }
  112. /**
  113. * Deletes a cache entry.
  114. *
  115. * @param string $url The URL of the entry to delete.
  116. */
  117. private function

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