Prepare an APIv2 call to improve sync performance on phone (battery)

controller/smscontroller.php

@@ -80,6 +80,20 @@ class SmsController extends Controller {
 		return new JSONResponse(array("smslist" => $smsList));
 	}
 
+	/**
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 * 
+	 * This function is used by API v2
+	 * Phone will get this ID to push recent messages
+	 * This call will be used combined with retrieveAllIds
+	 * but will be used more times
+	 */
+	public function retrieveLastTimestamp () {
+		$ts = $this->smsMapper->getLastTimestamp($this->userId);
+		return new JSONResponse(array("timestamp" => $ts));
+	}
+
 	/**
 	 * @NoAdminRequired
 	 * @NoCSRFRequired

db/smsmapper.php

@@ -72,6 +72,18 @@ class SmsMapper extends Mapper {
 		return $smsList;
 	}
 
+	public function getLastTimestamp ($userId) {
+		$query = \OCP\DB::prepare('SELECT max(sms_date) as mx FROM ' .
+			'*PREFIX*ocsms_smsdatas WHERE user_id = ?');
+		$result = $query->execute(array($userId));
+		
+		if ($row = $result->fetchRow()) {
+			return $row["mx"];
+		}
+
+		return 0;
+	}
+
 	public function getAllPeersPhoneNumbers ($userId) {
 		$query = \OCP\DB::prepare('SELECT sms_address FROM ' .
 		'*PREFIX*ocsms_smsdatas WHERE user_id = ? AND sms_mailbox IN (?,?)');