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<?php |
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|
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|
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if (!defined('ABSPATH')) { |
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exit; |
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} |
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|
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class ABJ_404_Solution_FileSync { |
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|
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/** @var self|null */ |
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private static $instance = null; |
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/** |
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* Test seam: install or clear the cached singleton instance without |
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* private-field reflection. Pass null to reset between tests; pass a |
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* configured instance (or double) to install it. Mirrors the setInstance() |
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* contract on DataAccess / PluginLogic (M105 singleton-reset seam). |
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* |
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* @param self|null $instance |
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* @return void |
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*/ |
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public static function setInstance($instance) { |
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self::$instance = $instance; |
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} |
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|
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|
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/** @return self */ |
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public static function getInstance(): self { |
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if (self::$instance == null) { |
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self::$instance = new ABJ_404_Solution_FileSync(); |
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} |
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|
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return self::$instance; |
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} |
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|
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/** |
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* @param string $key |
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* @return string |
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*/ |
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function getSyncFilePath(string $key): string { |
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$filePath = abj404_getUploadsDir() . 'SYNC_FILE_' . $key . '.txt'; |
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return $filePath; |
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} |
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|
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/** |
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* @param string $key |
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* @return string |
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*/ |
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function getOwnerFromFile(string $key): string { |
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$filePath = $this->getSyncFilePath($key); |
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|
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// Read and catch rather than check-then-read, so there is no TOCTOU |
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// window between "does it exist" and "read it". |
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try { |
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$contents = ABJ_404_Solution_FileSystemService::readFileContents($filePath, false); |
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return $contents; |
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} catch (Exception $e) { |
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// Empty means "no lock owner" to every caller, and for a missing |
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// file that is exactly right. For a file that EXISTS and could not |
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// be read it is dangerous: a permissions problem or a full disk |
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// then presents as an unlocked resource, two workers proceed at |
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// once, and nothing downstream can tell the difference. |
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// |
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// So report rather than decide. This class does file I/O; whether |
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// an unreadable lock file should stop the caller is lock policy, |
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// and lock policy lives in LockOwnerStore. Deciding here also meant |
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// writing a log line from inside a getter, which is its own problem |
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// (lint-hidden-write-getters) and a fair one: a get* that emits |
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// telemetry surprises every caller. |
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if (is_file($filePath)) { |
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throw $e; |
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} |
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return ""; |
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} |
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} |
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|
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/** |
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* @param string $key |
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* @param string $uniqueID |
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* @return void |
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*/ |
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function writeOwnerToFile(string $key, string $uniqueID): void { |
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$filePath = $this->getSyncFilePath($key); |
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|
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// Fixed: Check return value to handle write failures (disk full, permissions, etc.) |
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$result = @file_put_contents($filePath, $uniqueID, LOCK_EX); |
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|
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if ($result === false) { |
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throw new Exception("Failed to write lock file: " . $filePath); |
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} |
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} |
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|
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/** |
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* @param string $uniqueID |
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* @param string $key |
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* @return void |
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*/ |
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function releaseLock(string $uniqueID, string $key): void { |
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$filePath = $this->getSyncFilePath($key); |
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ABJ_404_Solution_FileSystemService::safeUnlink($filePath); |
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} |
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|
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} |
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|
