<?php

/**

* Invalidates cache for JSON payloads used in short-lived tasks.

* Handles edge cases like invalid cache keys and database connection issues.

*

* @param string $cacheKey The cache key for the JSON payload.

* @param int $ttl Time to live in seconds.

* @param string $db_host Database host.

* @param string $db_name Database name.

* @param string $db_user Database user.

* @param string $db_pass Database password.

* @return bool True on success, false on failure.

*/

function invalidateJsonCache(string $cacheKey, int $ttl, string $db_host, string $db_name, string $db_user, string $db_pass): bool

{

// Database connection details

$db_connection_string = "mysql:host=$db_host;dbname=$db_name;charset=utf8mb4";

try {

$pdo = new PDO($db_connection_string, $db_user, $db_pass);

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// Check if the cache key is valid

if (empty($cacheKey)) {

error_log("Invalid cache key provided.");

return false;

}

// SQL query to invalidate the cache entry

$sql = "DELETE FROM json_cache WHERE key = :key";

$stmt = $pdo->prepare($sql);

$stmt->bindParam(':key', $cacheKey, PDO::PARAM_STR);

$stmt->execute();

// Optionally, clear the cache after invalidating (e.g., using Redis or Memcached)

// Example: redis_del($redis, $cacheKey);

return true;

} catch (PDOException $e) {

error_log("Database error: " . $e->getMessage());

return false;

} catch (Exception $e) {

error_log("General error: " . $e->getMessage());

return false;

}

}

// Example usage (replace with your actual values)

/*

$cacheKey = 'my_json_data';

$ttl = 60; // Cache for 60 seconds

$db_host = 'localhost';

$db_name = 'my_database';

$db_user = 'my_user';

$db_pass = 'my_password';

if (invalidateJsonCache($cacheKey, $ttl, $db_host, $db_name, $db_user, $db_pass)) {

echo "Cache invalidated successfully.\n";

} else {

echo "Cache invalidation failed.\n";

}

*/

?>