From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.mail.ru (smtp1.mail.ru [94.100.179.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 2790C445320 for ; Thu, 6 Aug 2020 19:00:45 +0300 (MSK) References: From: Oleg Babin Message-ID: <6a8870f3-ac79-7021-941d-11b90e687282@tarantool.org> Date: Thu, 6 Aug 2020 19:00:43 +0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-GB Subject: Re: [Tarantool-patches] [PATCH 1/2] tuple: fix multikey field JSON access crash List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladislav Shpilevoy , tarantool-patches@dev.tarantool.org, alyapunov@tarantool.org, korablev@tarantool.org Hi! Thanks for your patch. It's not a review but I have a question. On 05/08/2020 02:45, Vladislav Shpilevoy wrote: > When a tuple had format with multikey indexes in it, any attempt > to get a multikey indexed field by a JSON path from Lua led to a > crash. > > That was because of incorrect interpretation of offset slot value > in tuple's field map. > > Tuple field map is an array stored before the tuple's MessagePack > data. Each element is a 4 byte offset to an indexed value to be > able to get it for O(1) time without MessagePack decoding of all > the previous fields. > > At least it was so before multikeys. Now tuple field map is not > just an array. It is rather a 2-level array, somehow similar to > ext4 FS. Some elements of the root array are positive numbers > pointing at data. Some elements point at a second 'indirect' > array, so called 'extra', size of which is individual for each > tuple. These second arrays are used by multikey indexes to store > offsets to each multikey indexed value in a tuple. Do json path updates use offsets? Is such issue relevant for them? I tried to update poisoned tuple but seems it works fine. But maybe I've missed something.