public static function processDownloadFromQueue($syncProcessID)
{
Zotero_DB::beginTransaction();
// Get a queued process
$smallestFirst = Z_CONFIG::$SYNC_DOWNLOAD_SMALLEST_FIRST;
$sql = "SELECT syncDownloadQueueID, SDQ.userID,\n\t\t\t\tUNIX_TIMESTAMP(lastsync) AS lastsync, version, params, added, objects, ipAddress\n\t\t\t\tFROM syncDownloadQueue SDQ JOIN sessions USING (sessionID)\n\t\t\t\tWHERE started IS NULL ORDER BY tries > 4, ";
if ($smallestFirst) {
$sql .= "ROUND(objects / 100), ";
}
$sql .= "added LIMIT 1 FOR UPDATE";
$row = Zotero_DB::rowQuery($sql);
// No pending processes
if (!$row) {
Zotero_DB::commit();
return 0;
}
$host = gethostbyname(gethostname());
$startedTimestamp = microtime(true);
$sql = "UPDATE syncDownloadQueue SET started=FROM_UNIXTIME(?), processorHost=INET_ATON(?) WHERE syncDownloadQueueID=?";
Zotero_DB::query($sql, array(round($startedTimestamp), $host, $row['syncDownloadQueueID']));
Zotero_DB::commit();
$error = false;
$lockError = false;
try {
if (Zotero_Sync::userIsWriteLocked($row['userID'])) {
$lockError = true;
throw new Exception("User is write locked");
}
$xml = self::getResponseXML($row['version']);
$doc = new DOMDocument();
$domResponse = dom_import_simplexml($xml);
$domResponse = $doc->importNode($domResponse, true);
$doc->appendChild($domResponse);
$params = !empty($row['params']) ? json_decode($row['params'], true) : [];
self::processDownloadInternal($row['userID'], $row['lastsync'], $doc, $row['syncDownloadQueueID'], $syncProcessID, $params);
} catch (Exception $e) {
$error = true;
$code = $e->getCode();
$msg = $e->getMessage();
}
Zotero_DB::beginTransaction();
// Mark download as finished — NULL indicates success
if (!$error) {
$timestamp = $doc->documentElement->getAttribute('timestamp');
$xmldata = $doc->saveXML();
$size = strlen($xmldata);
$sql = "UPDATE syncDownloadQueue SET finished=FROM_UNIXTIME(?), xmldata=? WHERE syncDownloadQueueID=?";
Zotero_DB::query($sql, array($timestamp, $xmldata, $row['syncDownloadQueueID']));
StatsD::increment("sync.process.download.queued.success");
StatsD::updateStats("sync.process.download.queued.size", $size);
StatsD::timing("sync.process.download.process", round((microtime(true) - $startedTimestamp) * 1000));
StatsD::timing("sync.process.download.total", max(0, time() - strtotime($row['added'])) * 1000);
self::logDownload($row['userID'], round($row['lastsync']), $row['objects'], $row['ipAddress'], $host, round((double) microtime(true) - $startedTimestamp, 2), max(0, min(time() - strtotime($row['added']), 65535)), 0);
} else {
if ($lockError || strpos($msg, "Lock wait timeout exceeded; try restarting transaction") !== false || strpos($msg, "Deadlock found when trying to get lock; try restarting transaction") !== false || strpos($msg, "Too many connections") !== false || strpos($msg, "Can't connect to MySQL server") !== false || $code == Z_ERROR_SHARD_UNAVAILABLE) {
Z_Core::logError($e);
$sql = "UPDATE syncDownloadQueue SET started=NULL, tries=tries+1 WHERE syncDownloadQueueID=?";
Zotero_DB::query($sql, $row['syncDownloadQueueID']);
$lockError = true;
StatsD::increment("sync.process.download.queued.errorTemporary");
} else {
Z_Core::logError($e);
$sql = "UPDATE syncDownloadQueue SET finished=?, errorCode=?,\n\t\t\t\t\t\terrorMessage=? WHERE syncDownloadQueueID=?";
Zotero_DB::query($sql, array(Zotero_DB::getTransactionTimestamp(), $e->getCode(), substr(serialize($e), 0, 65535), $row['syncDownloadQueueID']));
StatsD::increment("sync.process.download.queued.errorPermanent");
self::logDownload($row['userID'], $row['lastsync'], $row['objects'], $row['ipAddress'], $host, round((double) microtime(true) - $startedTimestamp, 2), max(0, min(time() - strtotime($row['added']), 65535)), 1);
}
}
Zotero_DB::commit();
if ($lockError) {
return -1;
} else {
if ($error) {
return -2;
}
}
return 1;
}
public function clear()
{
$this->sessionCheck();
if (Zotero_Sync::userIsReadLocked($this->userID) || Zotero_Sync::userIsWriteLocked($this->userID)) {
$message = "You cannot reset server data while one of your libraries " . "is locked for syncing. Please wait for all related syncs to complete.";
$this->error(400, 'SYNC_LOCKED', $message);
}
StatsD::increment("sync.clear");
Zotero_Users::clearAllData($this->userID);
$this->responseXML->addChild('cleared');
$this->end();
}