From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <c.ebner@proxmox.com>
Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits))
 (No client certificate requested)
 by lists.proxmox.com (Postfix) with ESMTPS id D3276912F4
 for <pbs-devel@lists.proxmox.com>; Wed,  3 Apr 2024 14:18:04 +0200 (CEST)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
 by firstgate.proxmox.com (Proxmox) with ESMTP id ADCE21764B
 for <pbs-devel@lists.proxmox.com>; Wed,  3 Apr 2024 14:18:04 +0200 (CEST)
Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com
 [94.136.29.106])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256)
 (No client certificate requested)
 by firstgate.proxmox.com (Proxmox) with ESMTPS
 for <pbs-devel@lists.proxmox.com>; Wed,  3 Apr 2024 14:18:03 +0200 (CEST)
Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1])
 by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 7D15344D74
 for <pbs-devel@lists.proxmox.com>; Wed,  3 Apr 2024 14:18:03 +0200 (CEST)
Message-ID: <a61a16a3-65f7-4aec-b3bc-90b8d2c5c1bb@proxmox.com>
Date: Wed, 3 Apr 2024 14:18:02 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
To: Proxmox Backup Server development discussion <pbs-devel@lists.proxmox.com>,
 =?UTF-8?Q?Fabian_Gr=C3=BCnbichler?= <f.gruenbichler@proxmox.com>
References: <20240328123707.336951-1-c.ebner@proxmox.com>
 <20240328123707.336951-8-c.ebner@proxmox.com>
 <1712138653.sp8y5k19rp.astroid@yuna.none>
Content-Language: en-US, de-DE
From: Christian Ebner <c.ebner@proxmox.com>
In-Reply-To: <1712138653.sp8y5k19rp.astroid@yuna.none>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-SPAM-LEVEL: Spam detection results:  0
 AWL 0.029 Adjusted score from AWL reputation of From: address
 BAYES_00                 -1.9 Bayes spam probability is 0 to 1%
 DMARC_MISSING             0.1 Missing DMARC policy
 KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment
 SPF_HELO_NONE           0.001 SPF: HELO does not publish an SPF Record
 SPF_PASS               -0.001 SPF: sender matches SPF record
Subject: Re: [pbs-devel] [PATCH v3 pxar 07/58] decoder/accessor: add
 optional payload input stream
X-BeenThere: pbs-devel@lists.proxmox.com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Proxmox Backup Server development discussion
 <pbs-devel.lists.proxmox.com>
List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pbs-devel>, 
 <mailto:pbs-devel-request@lists.proxmox.com?subject=unsubscribe>
List-Archive: <http://lists.proxmox.com/pipermail/pbs-devel/>
List-Post: <mailto:pbs-devel@lists.proxmox.com>
List-Help: <mailto:pbs-devel-request@lists.proxmox.com?subject=help>
List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel>, 
 <mailto:pbs-devel-request@lists.proxmox.com?subject=subscribe>
X-List-Received-Date: Wed, 03 Apr 2024 12:18:04 -0000

On 4/3/24 12:38, Fabian Grünbichler wrote:
>> +
>> +                if let Some(payload_input) = self.payload_input.as_mut() {
> 
> this condition (cted below)
> 
>> +                    if seq_read_position(payload_input)
>> +                        .await
>> +                        .transpose()?
>> +                        .is_none()
>> +                    {
>> +                        // Skip payload padding for injected chunks in sequential decoder
>> +                        let to_skip = payload_ref.offset - self.payload_consumed;
> 
> should we add a check here for the invariant that offsets should only
> ever be increasing? (and avoid an underflow for corrupt/invalid archives
> ;))

This is called by both, seq and random access decoder instances, so that 
will not be possible I guess.

> 
>> +                        self.skip_payload(to_skip).await?;
>> +                    }
>> +                }
>> +
>> +                if let Some(payload_input) = self.payload_input.as_mut() {
> 
> and this condition here are the same?

While this seems just duplicate, it makes the borrow checker happy as 
otherwise it complains that the &mut self borrow of the skip_payload 
call and the following seq_read_entry call taking the payload_input are 
in conflict.
I am happy for any hint on how to make the borrow checker happy without 
having to perform the if check two time
> 
>> +                    let header: u64 = seq_read_entry(payload_input).await?;
> 
> why not read a Header here?

Yeah, definitely better to read the full header, and then check against 
the htype and content_size(). Will change this for the next version.

> 
> 
> then these could use the size helpers of Header ;)