<div dir="ltr"><div class="gmail_default" style="font-size:small;color:rgb(0,0,0)">This looks like a reasonable and good suggestion.</div><div class="gmail_default" style="font-size:small;color:rgb(0,0,0)"><br></div><div class="gmail_default" style="font-size:small;color:rgb(0,0,0)">I created issue 987 for it: <a href="https://github.com/connamara/quickfixn/issues/987">https://github.com/connamara/quickfixn/issues/987</a></div><div class="gmail_default" style="font-size:small;color:rgb(0,0,0)"><br></div><div class="gmail_default" style="font-size:small;color:rgb(0,0,0)">I hope to take a deeper look within the next month or 2.</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Thu, Oct 30, 2025 at 5:02 AM Andreas Meisner via Quickfixn <<a href="mailto:quickfixn@lists.quickfixn.com">quickfixn@lists.quickfixn.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi @all,<br>
<br>
this is my first email on this list and I am not yet familiar with the <br>
rules here.<br>
<br>
I have found the following issue, because I have implemented a <br>
IMessageStore for MSSQL server (using EF) having indices on the database <br>
tables:<br>
<br>
In class Session we have the method Persist(Message, string):<br>
<br>
protected void Persist(Message message, string messageString)<br>
{<br>
if (PersistMessages)<br>
{<br>
SeqNumType msgSeqNum = <br>
message.Header.GetULong(Fields.Tags.MsgSeqNum);<br>
_state.Set(msgSeqNum, messageString);<br>
}<br>
_state.IncrNextSenderMsgSeqNum();<br>
}<br>
<br>
The call of Set() and IncrNextSenderMsgSeqNum() should be in one <br>
transaction, but currently I have a straight forward implementation with <br>
no dependencies between these methods. In my case a call to Set() was <br>
successful, but the call to IncrNextSenderMsgSeqNum() failed, leaving <br>
the database in an inconsitant state. I think the same could happen when <br>
using FileStore, but here we do not have an index that could cause an <br>
exception.<br>
<br>
I can catch this in my DbMessageStore implementation, but it would be <br>
nicer to have only one method in this case.<br>
<br>
So my proposal for a change is:<br>
<br>
<br>
1. Add a new method in interface IMessageStore with a default <br>
implementation:<br>
<br>
public interface IMessageStore : IDisposable<br>
{<br>
<br>
// ... existing members<br>
<br>
public bool SetAndIncrNextSenderMsgSeqNum(SeqNumType msgSeqNum, <br>
string msg)<br>
{<br>
bool result = Set(msgSeqNum, msg);<br>
IncrNextSenderMsgSeqNum();<br>
return result;<br>
}<br>
}<br>
<br>
2. Add the method with the same signature to class SessionState:<br>
<br>
public bool SetAndIncrNextSenderMsgSeqNum(SeqNumType msgSeqNum, <br>
string msg)<br>
{<br>
lock (_sync) { return <br>
MessageStore.SetAndIncrNextSenderMsgSeqNum(msgSeqNum, msg); }<br>
}<br>
<br>
3. Call the new method in class Session:<br>
<br>
protected void Persist(Message message, string messageString)<br>
{<br>
if (PersistMessages)<br>
{<br>
SeqNumType msgSeqNum = <br>
message.Header.GetULong(Fields.Tags.MsgSeqNum);<br>
_state.SetAndIncrNextSenderMsgSeqNum(msgSeqNum, <br>
messageString);<br>
}<br>
else<br>
{<br>
_state.IncrNextSenderMsgSeqNum();<br>
}<br>
}<br>
<br>
This change should be 99.9% backwards compatible and should not affect <br>
any existing implementation. The only difference (the 0.1%) is that the <br>
call to Set() and IncrNextSenderMsgSeqNum() is in one lock(_sync) in <br>
class SessionState, but this should be also an improvement.<br>
<br>
Please let me know, if I can add a new pull request with these changes.<br>
<br>
<br>
Thanks,<br>
Andreas<br>
<br>
<br>
-- <br>
Andreas Meisner<br>
Software-Development<br>
<br>
C/Poeto Alonso Quesada 30<br>
35310 Santa Brígida<br>
Las Palmas Gran Canaria<br>
Spain<br>
<br>
Tel. +49 176 42026763<br>
Email: <a href="mailto:software@meisner.de" target="_blank">software@meisner.de</a><br>
Web: <a href="http://software.meisner.de" rel="noreferrer" target="_blank">http://software.meisner.de</a><br>
<br>
N.I.E. Y-9624964-F<br>
<br>
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</blockquote></div><div><br clear="all"></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><span><div dir="ltr" style="margin-left:0pt" align="left"><table style="border:none;border-collapse:collapse"><colgroup><col width="122"><col width="298"></colgroup><tbody><tr style="height:84.75pt"><td style="vertical-align:top;overflow:hidden"><span style="border:none;display:inline-block;overflow:hidden;width:105px;height:83px"><a href="https://www.connamara.com" target="_blank"><img src="https://lh4.googleusercontent.com/1ZKItKWIoLUepUXvEXgEeZWBlntjas7UxLPLuLLnsApbxAcRepKELA_SwZBe1BWEZ3huC6sJdz2ZzvUYLNgu56Zcm8bo2R_iLzXZVjDmMo67675iop6mEMOg_Y6q8Mtz7ylOW9t8RazXt-tyJtEyhE0" width="105" height="83" style="margin-left: 0px; margin-top: 0px;"></a></span></td><td style="vertical-align:top;padding:5pt;overflow:hidden"><br><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Archivo,sans-serif;color:rgb(0,65,107);background-color:transparent;vertical-align:baseline">Grant Birchmeier</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Archivo,sans-serif;color:rgb(0,65,107);background-color:transparent;vertical-align:baseline">Director of Engineering, Connamara</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Archivo,sans-serif;color:rgb(0,65,107);background-color:transparent;vertical-align:baseline"><a href="mailto:gbirchmeier@connamara.com" target="_blank">gbirchmeier@connamara.com</a></span></p></td></tr></tbody></table></div></span></div></div></div>
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