Re: [PATCH] Re: Adding a reset option to the session helper

 On Tue, 04 Oct 2011 23:21:13 +0100, Andrew Beverley wrote:
> On Tue, 2011-10-04 at 18:59 +0100, Andrew Beverley wrote:
>> However, I'm now having problems with multiple instances of the
>> session
>> helper writing to the same database. I thought I had fixed this with
>> the
>> ->sync option, but it appears not. If I open multiple instances of
>> ext_session_acl in terminal windows on the same database, then I do
>> not
>> get consistent results between each process. If I do a "LOGIN" on
>> one,
>> then I can still get "No session available" on the other. Any ideas
>> why
>> this might be? Is it a bug with db-185? Debugging shows that the key
>> does not exist in the second process, despite having been written in
>> the
>> first.
>
> After further investigation, the problem appears to be that the
> *read*
> database process is being cached (I'm not sure where). So even if the
> writing process syncs its changes to the DB file, these aren't
> reflected
> in the process that is reading the DB file.
>
> After a lot of Googling, the only way I can see to fix this is to
> close
> and re-open the database on every read. This is very messy, but does
> anyone have any better suggestions?
>
>> I also found another bug with the session helper when used in active
>> mode (which might have been created by me). I'll submit a patch once
>> I've got a way ahead with the DB.
>
> The problem here was that the "LOGIN" was being written to the
> database,
> as well as the desired key (even though the correct string length was
> specified). So it was never actually matching a subsequent query.
>
> Please find attached a patch that fixes both of these. The fix for
> the
> first is messy; the fix for the second is simple, just using strtok
> instead of strrchr, so as to force the key to be correctly truncated.
>
> Andy

 The reason it was doing strrchr() was that people are free to specify
 multi-word keys. We need to scan from the end of the line backwards for
 the token.
  I think strrchr() is still probably the best to use. The buffer is
 local so if you can map the strrchr output to an offset it can be freely
 adjusted to add \0 in the space before "LOGIN".

 Amos
Received on Tue Oct 04 2011 - 23:07:44 MDT