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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_SynchronizationUtils { |
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|
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/** A prefix for keys used for synchronization methods. |
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* @var string */ |
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const SYNC_KEY_PREFIX = 'SYNC_'; |
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|
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/** @var bool|null */ |
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static $usingFileMode = null; |
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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 = $instance; |
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} |
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|
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/** |
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* Test seam: clear all cached static state (the singleton instance and the |
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* file-vs-DB lock-mode latch) without private-field reflection. |
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* |
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* @return void |
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*/ |
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public static function resetForTests() { |
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self::$instance = null; |
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self::$usingFileMode = null; |
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} |
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|
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|
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/** @return self */ |
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public static function getInstance() { |
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if (self::$instance == null) { |
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self::$instance = new ABJ_404_Solution_SynchronizationUtils(); |
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} |
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|
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return self::$instance; |
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} |
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|
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/** @return string */ |
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private function getFileModePath() { |
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return abj404_getUploadsDir() . 'sync_mode_file.txt'; |
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} |
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|
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/** @return string */ |
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private function getOptionsModePath() { |
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return abj404_getUploadsDir() . 'sync_mode_options.txt'; |
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} |
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|
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/** @return bool */ |
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private function isFileMode() { |
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if (self::$usingFileMode == null) { |
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$fileModePath = $this->getFileModePath(); |
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$optionsModePath = $this->getOptionsModePath(); |
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if (file_exists($fileModePath) && file_exists($optionsModePath)) { |
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ABJ_404_Solution_FileSystemService::safeUnlink($fileModePath); |
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ABJ_404_Solution_FileSystemService::safeUnlink($optionsModePath); |
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} |
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|
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if (file_exists($fileModePath)) { |
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$usingFileMode = true; |
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|
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} else if (file_exists($optionsModePath)) { |
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$usingFileMode = false; |
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|
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} else { |
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// initialize |
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$pass = true; |
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$keyForTesting = ABJ404_PP . "_" . self::SYNC_KEY_PREFIX . 'testing'; |
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$uniqueID = $this->createUniqueID('testing'); |
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|
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// test saving. |
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update_option($keyForTesting, $uniqueID); |
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$result = get_option($keyForTesting); |
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if ($result != $uniqueID) { |
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$pass = false; |
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} |
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|
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// test deleting. |
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delete_option($keyForTesting); |
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$result = get_option($keyForTesting); |
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if ($result != null && $result != '') { |
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$pass = false; |
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} |
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|
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ABJ_404_Solution_FileSystemService::createDirectoryWithErrorMessages(dirname($optionsModePath)); |
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if ($pass) { |
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$usingFileMode = false; |
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touch($optionsModePath); |
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} else { |
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$usingFileMode = true; |
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touch($fileModePath); |
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} |
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} |
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self::$usingFileMode = $usingFileMode; |
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} |
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|
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return self::$usingFileMode; |
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} |
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|
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/** @return void */ |
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function switchToFileSyncMode() { |
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self::$usingFileMode = true; |
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$optionsModePath = $this->getOptionsModePath(); |
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ABJ_404_Solution_FileSystemService::safeUnlink($optionsModePath); |
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|
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$fileModePath = $this->getFileModePath(); |
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ABJ_404_Solution_FileSystemService::createDirectoryWithErrorMessages(dirname($fileModePath)); |
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touch($fileModePath); |
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} |
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|
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/** |
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* @param string $keyFromUser |
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* @return string |
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*/ |
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private function createInternalKey($keyFromUser) { |
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return ABJ404_PP . "_" . self::SYNC_KEY_PREFIX . $keyFromUser; |
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} |
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|
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/** |
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* @param string $keyFromUser |
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* @return string |
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*/ |
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private function createUniqueID($keyFromUser) { |
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return abj_clock()->nowFloat() . "_" . $keyFromUser . '_' . $this->uniqidReal() . uniqid('', true); |
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} |
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|
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/** Returns an empty string if the lock is not acquired. |
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* @param string $synchronizedKeyFromUser |
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* @return string the unique ID that was used. This is needed to release the lock. Or an empty string if |
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* the lock wasn't acquired. |
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*/ |
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function synchronizerAcquireLockTry($synchronizedKeyFromUser) { |
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$uniqueID = $this->createUniqueID($synchronizedKeyFromUser); |
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$internalSynchronizedKey = $this->createInternalKey($synchronizedKeyFromUser); |
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|
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// don't let anyone hold the lock for too long. |
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$this->fixAnUnforeseenIssue($synchronizedKeyFromUser); |
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|
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// acquire the lock. |
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$currentOwner = $this->readOwner($internalSynchronizedKey); |
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// only write the value if it's empty. |
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if (empty($currentOwner)) { |
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$this->writeOwner($internalSynchronizedKey, $uniqueID); |
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} |
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// give a different thread that ran at the same time a chance to overwrite our value. |
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time_nanosleep(0, 10000000 * 30); // 10000000 is 1/100 of a second. |
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// check and see if we're the owner yet. |
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$currentOwner = $this->readOwner($internalSynchronizedKey); |
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|
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if ($currentOwner == $uniqueID) { |
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return $uniqueID; |
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} |
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|
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return ''; |
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} |
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|
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/** Remove the lock if it's been in place for too long. |
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* @param string $synchronizedKeyFromUser |
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* @return void |
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*/ |
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function fixAnUnforeseenIssue($synchronizedKeyFromUser) { |
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$internalSynchronizedKey = $this->createInternalKey($synchronizedKeyFromUser); |
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|
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$uniqueID = $this->readOwner($internalSynchronizedKey); |
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|
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if (empty($uniqueID)) { |
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return; |
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} |
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|
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$uniqueIDInfo = explode("_", $uniqueID); |
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|
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$createTime = $uniqueIDInfo[0]; |
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|
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$timePassed = abj_clock()->nowFloat() - (float)$createTime; |
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|
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$maxExecutionTime = ini_get('max_execution_time'); |
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if (empty($maxExecutionTime) || $maxExecutionTime < 1) { |
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$maxExecutionTime = 60; |
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} else { |
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$maxExecutionTime *= 2; |
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} |
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|
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// it should have been released by now. |
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if ($timePassed > $maxExecutionTime) { |
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$this->deleteOwner($uniqueID, $internalSynchronizedKey); |
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$valueAfterDelete = $this->readOwner($internalSynchronizedKey); |
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|
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// if options mode failed for some reason then switch to file sync mode. |
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if ($valueAfterDelete != null && $valueAfterDelete != '' && |
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!$this->isFileMode()) { |
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$this->switchToFileSyncMode(); |
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return; |
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} |
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|
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$uniqueIDForDebugging = $this->createUniqueID('DEBUG_KEY'); |
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$logger = abj_service('logging'); |
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$logger->errorMessage("Forcibly removed synchronization after " . |
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$timePassed . " seconds for the " . "key " . $internalSynchronizedKey . |
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" with value: " . $uniqueID . ', value after delete: ' . $valueAfterDelete . |
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", microtime: " . abj_clock()->nowFloat() . ", unique ID for debugging: " . |
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$uniqueIDForDebugging . ", File sync mode: " . json_encode($this->isFileMode())); |
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} |
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} |
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|
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/** Waits until the lock can be acquired and then returns the unique ID. |
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* @param string $synchronizedKeyFromUser |
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* @return string the unique ID that was used. This is needed to release the lock. |
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*/ |
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function synchronizerAcquireLockWithWait($synchronizedKeyFromUser) { |
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$uniqueID = $this->createUniqueID($synchronizedKeyFromUser); |
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$internalSynchronizedKey = $this->createInternalKey($synchronizedKeyFromUser); |
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|
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$this->fixAnUnforeseenIssue($synchronizedKeyFromUser); |
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$iterations = 0; |
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|
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// acquire the lock. |
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$currentOwner = $this->readOwner($internalSynchronizedKey); |
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while ($currentOwner != $uniqueID) { |
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// only write the value if it's empty. |
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if (empty($currentOwner)) { |
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$this->writeOwner($internalSynchronizedKey, $uniqueID); |
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} |
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// give a different thread that ran at the same time a chance to overwrite our value. |
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time_nanosleep(0, 500000000); // 10000000 is 1/100 of a second. 500000000 is 1/2 of a second. |
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// check and see if we're the owner yet. |
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$currentOwner = $this->readOwner($internalSynchronizedKey); |
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|
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$iterations++; |
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if ($iterations % 500 == 0) { |
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$this->fixAnUnforeseenIssue($synchronizedKeyFromUser); |
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} |
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} |
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|
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return $uniqueID; |
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} |
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|
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/** Release the lock for a synchronized block. Should be done in a finally block. |
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* @param string $uniqueID |
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* @param string $synchronizedKeyFromUser |
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* @return void |
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* @throws Exception |
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*/ |
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function synchronizerReleaseLock($uniqueID, $synchronizedKeyFromUser) { |
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$internalSynchronizedKey = $this->createInternalKey($synchronizedKeyFromUser); |
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|
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$currentLockHolder = $this->readOwner($internalSynchronizedKey); |
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|
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if ($uniqueID == $currentLockHolder) { |
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$this->deleteOwner($uniqueID, $internalSynchronizedKey); |
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|
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} else { |
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// Fail silently instead of throwing fatal exception. |
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$logger = abj_service('logging'); |
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$logger->debugMessage("Synchronization lock release mismatch. " . |
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"Synchronized key: $synchronizedKeyFromUser, current holder: $currentLockHolder, " . |
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"attempted release by: $uniqueID"); |
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} |
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} |
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|
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/** |
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* @param string $key |
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* @return string |
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*/ |
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function readOwner($key) { |
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$owner = ''; |
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if ($this->isFileMode()) { |
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$fileSync = ABJ_404_Solution_FileSync::getInstance(); |
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$owner = $fileSync->getOwnerFromFile($key); |
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|
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} else { |
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// MULTISITE: Use network-aware option for N-gram locks |
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$ownerRaw = $this->getNetworkAwareOption($key); |
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$owner = is_string($ownerRaw) ? $ownerRaw : ''; |
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} |
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|
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return $owner; |
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} |
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/** |
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* @param string $key |
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* @param string $owner |
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* @return void |
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*/ |
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function writeOwner($key, $owner) { |
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if ($this->isFileMode()) { |
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$fileSync = ABJ_404_Solution_FileSync::getInstance(); |
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$fileSync->writeOwnerToFile($key, $owner); |
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} else { |
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// MULTISITE: Use network-aware option for N-gram locks |
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$this->updateNetworkAwareOption($key, $owner); |
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} |
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} |
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/** |
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* @param string $owner |
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* @param string $key |
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* @return void |
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*/ |
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function deleteOwner($owner, $key) { |
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if ($this->isFileMode()) { |
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$fileSync = ABJ_404_Solution_FileSync::getInstance(); |
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$fileSync->releaseLock($owner, $key); |
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} else { |
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// MULTISITE: Use network-aware option for N-gram locks |
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$this->deleteNetworkAwareOption($key); |
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} |
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} |
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|
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/** |
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* Check if the plugin is network-activated in a multisite environment. |
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* |
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* @return bool True if network-activated, false otherwise |
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*/ |
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private function isNetworkActivated() { |
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if (!is_multisite()) { |
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return false; |
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} |
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|
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if (!function_exists('is_plugin_active_for_network')) { |
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require_once ABSPATH . '/wp-admin/includes/plugin.php'; |
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} |
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|
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return is_plugin_active_for_network(plugin_basename(ABJ404_FILE)); |
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} |
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|
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/** |
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* Determine if this lock key should use network-wide storage. |
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* |
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* N-gram rebuild locks (ngram_rebuild, ngram_schedule) must be network-wide |
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* to coordinate across all sites. Other locks remain site-specific. |
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* |
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* @param string $key The lock key |
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* @return bool True if should use network-wide storage |
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*/ |
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private function shouldUseNetworkStorage($key) { |
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// Extract the user-provided key from the internal key format |
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$userKey = str_replace(ABJ404_PP . "_" . self::SYNC_KEY_PREFIX, '', $key); |
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|
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// N-gram locks must be network-wide when network-activated |
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$networkWideLocks = ['ngram_rebuild', 'ngram_schedule']; |
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|
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return $this->isNetworkActivated() && in_array($userKey, $networkWideLocks); |
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} |
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|
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/** |
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* Get an option value, using network-wide storage for N-gram locks. |
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* |
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* @param string $key The option key |
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* @param mixed $default Default value if option doesn't exist |
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* @return mixed The option value |
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*/ |
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private function getNetworkAwareOption($key, $default = false) { |
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if ($this->shouldUseNetworkStorage($key)) { |
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return get_site_option($key, $default); |
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} |
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return get_option($key, $default); |
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} |
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|
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/** |
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* Update an option value, using network-wide storage for N-gram locks. |
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* |
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* @param string $key The option key |
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* @param mixed $value The value to store |
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* @return bool True if updated successfully |
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*/ |
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private function updateNetworkAwareOption($key, $value) { |
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if ($this->shouldUseNetworkStorage($key)) { |
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return update_site_option($key, $value); |
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} |
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return update_option($key, $value); |
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} |
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|
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/** |
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* Delete an option, using network-wide storage for N-gram locks. |
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* |
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* @param string $key The option key |
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* @return bool True if deleted successfully |
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*/ |
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private function deleteNetworkAwareOption($key) { |
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if ($this->shouldUseNetworkStorage($key)) { |
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return delete_site_option($key); |
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} |
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return delete_option($key); |
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} |
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|
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/** |
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* @return string a random string of characters. |
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* @throws Exception |
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*/ |
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function uniqidReal() { |
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$bytes = null; |
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if (function_exists("random_bytes")) { |
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try { |
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$bytes = random_bytes(max(1, (int)ceil(13 / 2))); |
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} catch (Exception $e) { // allow-silent-catch: random_bytes unavailable; fall through to openssl then uniqid |
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$bytes = null; |
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} |
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} |
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|
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if ($bytes == null && function_exists("openssl_random_pseudo_bytes")) { |
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try { |
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$bytes = openssl_random_pseudo_bytes((int)ceil(13 / 2)); |
| 415 |
} catch (Exception $e) { // allow-silent-catch: openssl fallback unavailable; fall through to uniqid |
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$bytes = null; |
| 417 |
} |
| 418 |
} |
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|
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if ($bytes != null) { |
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return bin2hex($bytes); |
| 422 |
} |
| 423 |
return uniqid("", true); |
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} |
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|
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} |
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|
