1. <?php
  3. /**
  4. * Message Queue Result Caching for Monitoring
  5. *
  6. * This script provides a mechanism to cache the results of message queue operations
  7. * for monitoring purposes. It includes verbose logging to track cache hits, misses,
  8. * and errors.
  9. */
  11. class MessageQueueCache {
  13. private $cache = []; // Simple in-memory cache
  14. private $logFile = 'message_queue_cache.log'; // Log file path
  16. /**
  17. * Constructor
  18. */
  19. public function __construct($logFile = 'message_queue_cache.log') {
  20. $this->logFile = $logFile;
  21. $this->logMessage("Cache initialized.");
  22. }
  24. /**
  25. * Cache a message queue operation result.
  26. *
  27. * @param string $key The cache key (e.g., message queue name + operation).
  28. * @param mixed $result The result to be cached.
  29. * @param int $expiryTime (optional) Time to live in seconds. Defaults to 3600 (1 hour).
  30. * @return bool True on success, false on failure.
  31. */
  32. public function cacheResult(string $key, $result, int $expiryTime = 3600): bool {
  33. $expiry = time() + $expiryTime;
  34. $this->cache[$key] = [
  35. 'result' => $result,
  36. 'expiry' => $expiry
  37. ];
  39. $this->logMessage("Cached result for key: $key, expiry: {$expiry}");
  40. return true;
  41. }
  43. /**
  44. * Retrieve a cached result.
  45. *
  46. * @param string $key The cache key.
  47. * @return mixed The cached result, or null if not found or expired.
  48. */
  49. public function getResult(string $key) {
  50. if (isset($this->cache[$key])) {
  51. $entry = $this->cache[$key];
  52. if ($entry['expiry'] > time()) {
  53. $this->logMessage("Cache hit for key: $key");
  54. return $entry['result'];
  55. } else {
  56. $this->logMessage("Cache expired for key: $key");
  57. unset($this->cache[$key]); // Remove expired entry
  58. return null;
  59. }
  60. } else {
  61. $this->logMessage("Cache miss for key: $key");
  62. return null;
  63. }
  64. }
  66. /**
  67. * Remove a cached item.
  68. *
  69. * @param string $key The key of the item to remove.
  70. * @return bool True on success, false if the key doesn't exist.
  71. */
  72. public function removeResult(string $key): bool {
  73. if (isset($this->cache[$key])) {
  74. unset($this->cache[$key]);
  75. $this->logMessage("Removed result for key: $key");
  76. return true;
  77. } else {
  78. $this->logMessage("Key not found for removal: $key");
  79. return false;
  80. }
  81. }
  83. /**
  84. * Log a message to the log file.
  85. *
  86. * @param string $message The message to log.
  87. */
  88. private function logMessage(string $message) {
  89. $timestamp = date('Y-m-d H:i:s');
  90. $logEntry = "[$timestamp] $message\n";
  91. file_put_contents($this->logFile, $logEntry, FILE_APPEND);
  92. }
  93. }
  96. // Example Usage:
  97. $cache = new MessageQueueCache();
  99. // Simulate a message queue operation
  100. $result = 'Data from message queue';
  102. // Cache the result
  103. if ($cache->cacheResult('my_queue_task', $result, 60)) { //Cache for 60 seconds
  104. // Use the cached result
  105. $retrievedResult = $cache->getResult('my_queue_task');
  106. echo "Retrieved result: " . $retrievedResult . "\n";
  107. } else {
  108. echo "Failed to cache result.\n";
  109. }
  111. //Try to get expired result
  112. sleep(61);
  113. $retrievedResult = $cache->getResult('my_queue_task');
  114. echo "Retrieved result after expiry: " . ($retrievedResult === null ? 'null' : $retrievedResult) . "\n";
  116. $cache->removeResult('my_queue_task');
  117. echo "Removed result.\n";
  119. ?>

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