Re: [reSIProcate] Matching INFO requests and responses
I tested the branch code within our app and its working great for all
the scenarios. It looks good to go from my end.
-Aron
On Thu, Dec 9, 2010 at 11:16 AM, Francis Joanis
<francis.joanis@xxxxxxxxx> wrote:
> Hi,
> (thanks to you both for the suggestions and examples :))
> I went ahead and did a first working
> implementation: https://svn.resiprocate.org/rep/resiprocate/branches/b-nit-contents-20101209/
> I cached it as a smart pointer (SharedPtr<SipMessage>) since that is what we
> are passing around anyway in the code. If we cached a copy instead, wouldn't
> we loose things like the branch parameter and other things set in
> DUM::send()?
> If no NIT request was sent, then users can validate the SharedPtr using the
> implicit conversion to bool (i.e. assert(mySharedPtr)).
> I've also modified BasicCall.cxx to test it (using both INFO and MESSAGE). I
> added assertions to ensure that it works and I also ran it under Valgrind on
> Linux. I will test it on Windows shortly.
> Feel free to comment,
> Francis
>
> On Thu, Dec 9, 2010 at 12:27 PM, Scott Godin <sgodin@xxxxxxxxxxxxxxx> wrote:
>>
>> The other InviteSession API's return objects by reference (ie.
>> SipMessage&) - you just need to handle the case when a caller accesses the
>> new API and you don't have a previous NIT request to return - returning a
>> reference to a static empty SipMessage makes sense for this case
>> (see InviteSession::getLocalOfferAnswer for an example.
>> Scott
>>
>> On Thu, Dec 9, 2010 at 12:02 PM, Aron Rosenberg <arosenberg@xxxxxxxxxxxx>
>> wrote:
>>>
>>> The only "main" reason to expand the callback API was to try and match
>>> ClientPagerMessageHandler...but I can rework the API to still keep the
>>> last request in the NIT queue but expose a new method on InviteSession
>>> called getLastNITRequest() . Should that return a
>>> auto_ptr<SipMessage>, const SipMessage* or something else?
>>>
>>> -Aron
>>>
>>>
>>> On Thu, Dec 9, 2010 at 6:53 AM, Scott Godin <sgodin@xxxxxxxxxxxxxxx>
>>> wrote:
>>> > That works for me too - in fact if you are going with this approach,
>>> > then
>>> > you may as well store the entire last IT request and make it available
>>> > instead of just the contents. A branch sounds like a good idea. : )
>>> > Thanks,
>>> > Scott
>>> >
>>> > On Thu, Dec 9, 2010 at 9:44 AM, Francis Joanis
>>> > <francis.joanis@xxxxxxxxx>
>>> > wrote:
>>> >>
>>> >> Hi,
>>> >> What about the following: rather than changing the DUM callbacks we
>>> >> could
>>> >> expose a reader to get the last Contents that was sent as a NIT? A bit
>>> >> like
>>> >> InviteSession::getRemoteSdp().
>>> >> That way, if someone wants to access it, it can simply be done in the
>>> >> on*
>>> >> callbacks. It would be cleaner in the sense that it won't change the
>>> >> interfaces at all.
>>> >> I will take care of ensuring that the memory is properly managed
>>> >> (helped
>>> >> by valgrind). I was thinking of cloning the contents of the message
>>> >> then
>>> >> assigning it to an auto_ptr as a member of InviteSession.
>>> >> I also want to code a test suite to ensure that it works for INFO,
>>> >> MESSAGE. We also need to ensure that it doesn't screw up the REFERs
>>> >> since
>>> >> currently nitComplete() is also called from Dialog.cxx.
>>> >> I was thinking of creating a branch to do this:
>>> >> b-nit-contents-20101209.
>>> >> Scott, let me know if you think that would be a bad idea ;)
>>> >> I'll let you know of my progress.
>>> >> Francis
>>> >>
>>> >> On Thu, Dec 9, 2010 at 1:43 AM, Aron Rosenberg
>>> >> <arosenberg@xxxxxxxxxxxx>
>>> >> wrote:
>>> >>>
>>> >>> I coded up a working patch based on Scott's feedback. The only
>>> >>> difference is that neither set of callbacks are pure-virtual now. I
>>> >>> figure this was better moving forward so that new code didn't need to
>>> >>> reference the old handler. It also seems that dealing with the
>>> >>> responses to INFO and MESSAGE aren't needed by most normal UA's. I
>>> >>> tested this patch with MESSAGE requests on the wire and it works.
>>> >>>
>>> >>> My only worry with this patch is that the memory handling semantics
>>> >>> are correct. mNITQueue holds SharedPtr<SipMessage> and it seems ok
>>> >>> for
>>> >>> that to stay valid after dum.send() has been called. On the callback
>>> >>> we pass a const Contents* rather than an auto_ptr since we can't get
>>> >>> an auto_ptr from SipMessage for Contents without a clone call. I
>>> >>> figure the developer who needs this longer than the life of the
>>> >>> callback can clone themselves.
>>> >>>
>>> >>> Francis: Can you test the INFO side to make sure you are getting the
>>> >>> right data back.
>>> >>>
>>> >>> -Aron
>>> >>>
>>> >>>
>>> >>> On Wed, Dec 8, 2010 at 1:56 PM, Scott Godin <sgodin@xxxxxxxxxxxxxxx>
>>> >>> wrote:
>>> >>> > I think we could add the new callback and leave the old one place.
>>> >>> > The
>>> >>> > new
>>> >>> > handler would not be virtual, and the default handler for the new
>>> >>> > callback
>>> >>> > would just throw away the contents and call the old callback. This
>>> >>> > will
>>> >>> > allow current applications to use the new dum version without any
>>> >>> > code
>>> >>> > changes. For applications that want to see the Contents, they
>>> >>> > would
>>> >>> > need to
>>> >>> > implement both callbacks, but the old callback can be left blank as
>>> >>> > it
>>> >>> > will
>>> >>> > never get called.
>>> >>> > Scott
>>> >>> >
>>> >>> > On Wed, Dec 8, 2010 at 4:36 PM, Aron Rosenberg
>>> >>> > <arosenberg@xxxxxxxxxxxx>
>>> >>> > wrote:
>>> >>> >>
>>> >>> >> The major use-case we need to fix is this:
>>> >>> >>
>>> >>> >> InviteSession based MESSAGE requests where the far end returns 415
>>> >>> >> (mime-type invalid) for some types (text/plain works, but
>>> >>> >> text/html
>>> >>> >> doesn't, application/im-iscomposing+xml doesn't). Without the
>>> >>> >> Contents* of the request that failed, we can't tell which type
>>> >>> >> failed
>>> >>> >> to determine if we need to notify the user sending the message.
>>> >>> >>
>>> >>> >> Scott: You have an opinion on if changing the callback type is an
>>> >>> >> ok
>>> >>> >> way to proceed?
>>> >>> >>
>>> >>> >> Francis: I have attached a prototype patch for this, it has only
>>> >>> >> been
>>> >>> >> compile tested if you want to try it and flesh it out some more.
>>> >>> >>
>>> >>> >> -Aron
>>> >>> >>
>>> >>> >> On Wed, Dec 8, 2010 at 12:39 PM, Francis Joanis
>>> >>> >> <francis.joanis@xxxxxxxxx> wrote:
>>> >>> >> > Hi,
>>> >>> >> > I like what you are proposing since any user-specific
>>> >>> >> > information
>>> >>> >> > would
>>> >>> >> > go
>>> >>> >> > in the user-derived Contents object: it acts a bit like an
>>> >>> >> > AppDialog/Set
>>> >>> >> > in
>>> >>> >> > that sense.
>>> >>> >> > We could even implement this by only caching the Contents of the
>>> >>> >> > last
>>> >>> >> > sent
>>> >>> >> > NIT request, since they're all sent serially (so no need to do
>>> >>> >> > the
>>> >>> >> > extra
>>> >>> >> > management on mNITQueue). This would mainly require adding a new
>>> >>> >> > member
>>> >>> >> > variable (probably an auto_ptr<Contents>) to InviteSession and
>>> >>> >> > changing
>>> >>> >> > the
>>> >>> >> > various on* callbacks in InviteSessionHandler.
>>> >>> >> > In the case of the REFER (which is also using mNITQueue), it
>>> >>> >> > would
>>> >>> >> > most
>>> >>> >> > likely have a NULL Contents, so it could get ignored on the
>>> >>> >> > callbacks
>>> >>> >> > (i.e.
>>> >>> >> > no need to modify the onRefer* callbacks).
>>> >>> >> > I started playing around with the code but I'd like to know if
>>> >>> >> > such
>>> >>> >> > a
>>> >>> >> > change
>>> >>> >> > would be a good one or not from the perspective of the more
>>> >>> >> > experienced
>>> >>> >> > developers. Changing callback APIs seems like a somewhat major
>>> >>> >> > change
>>> >>> >> > (i.e.
>>> >>> >> > it will break current apps) and I wouldn't want to do it unless
>>> >>> >> > there is
>>> >>> >> > really a good use case.
>>> >>> >> > Regards,
>>> >>> >> > Francis
>>> >>> >> >
>>> >>> >> >
>>> >>> >> > On Wed, Dec 8, 2010 at 1:32 PM, Aron Rosenberg
>>> >>> >> > <arosenberg@xxxxxxxxxxxx>
>>> >>> >> > wrote:
>>> >>> >> >>
>>> >>> >> >> For a slightly different issue (matching 415's to outbound
>>> >>> >> >> MESSAGE
>>> >>> >> >> requests) I was looking at modifying InviteSession to remove
>>> >>> >> >> the
>>> >>> >> >> SipMessage* from the mNITQueue upon end of transaction rather
>>> >>> >> >> than
>>> >>> >> >> beginning of transaction. We could then pass up the Contents*
>>> >>> >> >> like
>>> >>> >> >> is
>>> >>> >> >> done with ClientPagerMessage.
>>> >>> >> >>
>>> >>> >> >> onMessageSuccess(resip::InviteSessionHandle ish, const
>>> >>> >> >> resip::SipMessage&status) would become
>>> >>> >> >> onMessageSuccess(resip::InviteSessionHandle ish, const
>>> >>> >> >> resip::SipMessage&status, std::auto_ptr<Contents> contents)
>>> >>> >> >> onMessageFailure(resip::InviteSessionHandle ish, const
>>> >>> >> >> resip::SipMessage &status) would become
>>> >>> >> >> onMessageFailure(resip::InviteSessionHandle ish, const
>>> >>> >> >> resip::SipMessage &status, std::auto_ptr<Contents> contents)
>>> >>> >> >>
>>> >>> >> >> This would also work in the INFO cases with the same changes to
>>> >>> >> >> add
>>> >>> >> >> std::auto_ptr<Contents> contents to the callbacks.
>>> >>> >> >>
>>> >>> >> >> I also attempted to try the other way, dig into the
>>> >>> >> >> TransactionController / TU and create a "SipMessage*
>>> >>> >> >> findLastRequestForResponse(SipMessage*)" that used the tid, but
>>> >>> >> >> this
>>> >>> >> >> would require adding a number of public functions to SipStack,
>>> >>> >> >> TransactionMap and some other classes.
>>> >>> >> >>
>>> >>> >> >> -Aron
>>> >>> >> >>
>>> >>> >> >> Aron Rosenberg
>>> >>> >> >> Logitech Inc. (SightSpeed Group)
>>> >>> >> >>
>>> >>> >> >>
>>> >>> >> >>
>>> >>> >> >> On Wed, Dec 8, 2010 at 10:08 AM, Francis Joanis
>>> >>> >> >> <francis.joanis@xxxxxxxxx> wrote:
>>> >>> >> >> > So I guess it leaves me with the original workaround of
>>> >>> >> >> > leveraging
>>> >>> >> >> > the
>>> >>> >> >> > fact
>>> >>> >> >> > that all NITs are sequential. Also I think I could use an
>>> >>> >> >> > outgoing
>>> >>> >> >> > DumFeature to inspect outgoing messages, but that would be
>>> >>> >> >> > called
>>> >>> >> >> > for
>>> >>> >> >> > all
>>> >>> >> >> > outgoing messages, which will impact performance.
>>> >>> >> >> > Thanks,
>>> >>> >> >> > Francis
>>> >>> >> >> >
>>> >>> >> >> > On Wed, Dec 8, 2010 at 11:28 AM, Scott Godin
>>> >>> >> >> > <sgodin@xxxxxxxxxxxxxxx>
>>> >>> >> >> > wrote:
>>> >>> >> >> >>
>>> >>> >> >> >> The branch parameter is "reset" in DialogUsageManager send
>>> >>> >> >> >> (ln
>>> >>> >> >> >> 824)
>>> >>> >> >> >> -
>>> >>> >> >> >> so
>>> >>> >> >> >> it won't help to store the branch parameter in the message
>>> >>> >> >> >> created
>>> >>> >> >> >> (same
>>> >>> >> >> >> applies for onReadyToSend).
>>> >>> >> >> >> Scott
>>> >>> >> >> >>
>>> >>> >> >> >> On Wed, Dec 8, 2010 at 11:08 AM, Francis Joanis
>>> >>> >> >> >> <francis.joanis@xxxxxxxxx>
>>> >>> >> >> >> wrote:
>>> >>> >> >> >>>
>>> >>> >> >> >>> Hi Scott,
>>> >>> >> >> >>> Thanks for your reply.
>>> >>> >> >> >>> What about if we changed InviteSession::info/refer/message
>>> >>> >> >> >>> to
>>> >>> >> >> >>> return a
>>> >>> >> >> >>> _copy_ of the constructed SipMessage rather than returning
>>> >>> >> >> >>> void?
>>> >>> >> >> >>> I ran a quick test and it looks like the transaction id is
>>> >>> >> >> >>> set
>>> >>> >> >> >>> when
>>> >>> >> >> >>> the
>>> >>> >> >> >>> message is constructed. That way, I can immediately cache
>>> >>> >> >> >>> the
>>> >>> >> >> >>> SIP
>>> >>> >> >> >>> transaction id to pair it with my "key". This removes the
>>> >>> >> >> >>> need
>>> >>> >> >> >>> for
>>> >>> >> >> >>> my
>>> >>> >> >> >>> extra
>>> >>> >> >> >>> "key list" and does not require message inspection in
>>> >>> >> >> >>> onReadyToSend.
>>> >>> >> >> >>> (I've also attached a patch to do this.)
>>> >>> >> >> >>> Thanks,
>>> >>> >> >> >>> Francis
>>> >>> >> >> >>>
>>> >>> >> >> >>> On Wed, Dec 8, 2010 at 9:12 AM, Scott Godin
>>> >>> >> >> >>> <sgodin@xxxxxxxxxxxxxxx>
>>> >>> >> >> >>> wrote:
>>> >>> >> >> >>>>
>>> >>> >> >> >>>> ...inline...
>>> >>> >> >> >>>>
>>> >>> >> >> >>>> On Tue, Dec 7, 2010 at 8:40 PM, Francis Joanis
>>> >>> >> >> >>>> <francis.joanis@xxxxxxxxx> wrote:
>>> >>> >> >> >>>>>
>>> >>> >> >> >>>>> Hi guys,
>>> >>> >> >> >>>>> I have a question about sending multiple NIT messages
>>> >>> >> >> >>>>> logically
>>> >>> >> >> >>>>> "at
>>> >>> >> >> >>>>> the
>>> >>> >> >> >>>>> same time" (with DUM). I do know that the current code
>>> >>> >> >> >>>>> doesn't
>>> >>> >> >> >>>>> allow
>>> >>> >> >> >>>>> for
>>> >>> >> >> >>>>> real parallel NIT requests (i.e. the NIT queue in
>>> >>> >> >> >>>>> InviteSession)
>>> >>> >> >> >>>>> -
>>> >>> >> >> >>>>> but
>>> >>> >> >> >>>>> that's not my issue.
>>> >>> >> >> >>>>> The issue I have is regarding how to match incoming INFO
>>> >>> >> >> >>>>> responses
>>> >>> >> >> >>>>> to
>>> >>> >> >> >>>>> their request. Imagine I need to send INFO messages
>>> >>> >> >> >>>>> regarding
>>> >>> >> >> >>>>> application-specific transactions (like DB transactions
>>> >>> >> >> >>>>> or
>>> >>> >> >> >>>>> whatever
>>> >>> >> >> >>>>> application specific thing like a button click). I'll
>>> >>> >> >> >>>>> call
>>> >>> >> >> >>>>> those
>>> >>> >> >> >>>>> non-SIP
>>> >>> >> >> >>>>> transaction ids "keys".
>>> >>> >> >> >>>>> If I can't have the keys passed into the INFO body and
>>> >>> >> >> >>>>> then
>>> >>> >> >> >>>>> have
>>> >>> >> >> >>>>> them
>>> >>> >> >> >>>>> resupplied back into the INFO response, there is no easy
>>> >>> >> >> >>>>> way
>>> >>> >> >> >>>>> of
>>> >>> >> >> >>>>> matching
>>> >>> >> >> >>>>> which response is for which request (especially if my
>>> >>> >> >> >>>>> application
>>> >>> >> >> >>>>> would
>>> >>> >> >> >>>>> allow multiple requests to be sent (queued in NIT queue)
>>> >>> >> >> >>>>> at
>>> >>> >> >> >>>>> the
>>> >>> >> >> >>>>> same
>>> >>> >> >> >>>>> time).
>>> >>> >> >> >>>>> The "workaround" would be to leverage the fact that NITs
>>> >>> >> >> >>>>> in
>>> >>> >> >> >>>>> an
>>> >>> >> >> >>>>> INVITE
>>> >>> >> >> >>>>> dialog are all serialized: I could keep a separate list
>>> >>> >> >> >>>>> of
>>> >>> >> >> >>>>> "keys".
>>> >>> >> >> >>>>> If I were
>>> >>> >> >> >>>>> to add my key to the list right before sending the INFO
>>> >>> >> >> >>>>> message,
>>> >>> >> >> >>>>> I
>>> >>> >> >> >>>>> would
>>> >>> >> >> >>>>> then know that the next INFO response will relate to that
>>> >>> >> >> >>>>> key
>>> >>> >> >> >>>>> (oldest
>>> >>> >> >> >>>>> element of the key list). But this can get messy since I
>>> >>> >> >> >>>>> would
>>> >>> >> >> >>>>> need
>>> >>> >> >> >>>>> to make
>>> >>> >> >> >>>>> sure that the "key list" is properly managed.
>>> >>> >> >> >>>>
>>> >>> >> >> >>>> [Scott] This solution works without having to modify DUM,
>>> >>> >> >> >>>> and
>>> >>> >> >> >>>> its
>>> >>> >> >> >>>> likely very similar to how it would be implemented in DUM
>>> >>> >> >> >>>> if
>>> >>> >> >> >>>> we
>>> >>> >> >> >>>> added
>>> >>> >> >> >>>> some
>>> >>> >> >> >>>> kind of key/id to the info() call and response callback.
>>> >>> >> >> >>>> Alternatively, you
>>> >>> >> >> >>>> could track the transaction id's as the INFO messages flow
>>> >>> >> >> >>>> out
>>> >>> >> >> >>>> of
>>> >>> >> >> >>>> the
>>> >>> >> >> >>>> invite
>>> >>> >> >> >>>> session by watching the onReadyToSend callback, but I
>>> >>> >> >> >>>> don't
>>> >>> >> >> >>>> think
>>> >>> >> >> >>>> that
>>> >>> >> >> >>>> offers any advantage over assuming the requests are
>>> >>> >> >> >>>> serialized.
>>> >>> >> >> >>>>
>>> >>> >> >> >>>>>
>>> >>> >> >> >>>>> If I look at the similar scenario but with INVITE
>>> >>> >> >> >>>>> messages,
>>> >>> >> >> >>>>> one
>>> >>> >> >> >>>>> can
>>> >>> >> >> >>>>> easily leverage the AppDialogSet/... to do this: set the
>>> >>> >> >> >>>>> "key" on
>>> >>> >> >> >>>>> the
>>> >>> >> >> >>>>> AppDialogSet and then it will be easily accessible once
>>> >>> >> >> >>>>> INVITE
>>> >>> >> >> >>>>> responses
>>> >>> >> >> >>>>> arrive (extracted from the INVITE session).
>>> >>> >> >> >>>>> I was thinking of extracting the id of the SIP
>>> >>> >> >> >>>>> transaction
>>> >>> >> >> >>>>> created
>>> >>> >> >> >>>>> for
>>> >>> >> >> >>>>> the INFO to use it for a lookup between the SIP
>>> >>> >> >> >>>>> transaction
>>> >>> >> >> >>>>> id
>>> >>> >> >> >>>>> and
>>> >>> >> >> >>>>> my "key".
>>> >>> >> >> >>>>> That way, when handling onInfo* callbacks I would be able
>>> >>> >> >> >>>>> to
>>> >>> >> >> >>>>> access
>>> >>> >> >> >>>>> the SIP
>>> >>> >> >> >>>>> transaction id from the response message and map it with
>>> >>> >> >> >>>>> my
>>> >>> >> >> >>>>> "key".
>>> >>> >> >> >>>>> However, this might not be feasible if the SIP
>>> >>> >> >> >>>>> transaction id
>>> >>> >> >> >>>>> is
>>> >>> >> >> >>>>> unknown to the DUM at this time (prior to sending it).
>>> >>> >> >> >>>>> What do you make out of this?
>>> >>> >> >> >>>>> I suspect this will get worst if reSIProcate ever allows
>>> >>> >> >> >>>>> multiple
>>> >>> >> >> >>>>> NITs
>>> >>> >> >> >>>>> in parallel at the same time (in an INVITE dialog), since
>>> >>> >> >> >>>>> then
>>> >>> >> >> >>>>> there
>>> >>> >> >> >>>>> would
>>> >>> >> >> >>>>> really be no easy way of matching them up to application
>>> >>> >> >> >>>>> specific
>>> >>> >> >> >>>>> data (or
>>> >>> >> >> >>>>> am I asking for an AppTransaction class ;)?)
>>> >>> >> >> >>>>
>>> >>> >> >> >>>> [Scott] Not sure we would ever allow this - I remember
>>> >>> >> >> >>>> this
>>> >>> >> >> >>>> being
>>> >>> >> >> >>>> discouraged by the IETF.
>>> >>> >> >> >>>>
>>> >>> >> >> >>>>>
>>> >>> >> >> >>>>> Thanks a lot,
>>> >>> >> >> >>>>> Francis
>>> >>> >> >> >>>>> _______________________________________________
>>> >>> >> >> >>>>> resiprocate-devel mailing list
>>> >>> >> >> >>>>> resiprocate-devel@xxxxxxxxxxxxxxx
>>> >>> >> >> >>>>>
>>> >>> >> >> >>>>>
>>> >>> >> >> >>>>> https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>>> >>> >> >> >>>>
>>> >>> >> >> >>>
>>> >>> >> >> >>
>>> >>> >> >> >
>>> >>> >> >> >
>>> >>> >> >> > _______________________________________________
>>> >>> >> >> > resiprocate-devel mailing list
>>> >>> >> >> > resiprocate-devel@xxxxxxxxxxxxxxx
>>> >>> >> >> >
>>> >>> >> >> > https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>>> >>> >> >> >
>>> >>> >> >
>>> >>> >> >
>>> >>> >>
>>> >>> >> _______________________________________________
>>> >>> >> resiprocate-devel mailing list
>>> >>> >> resiprocate-devel@xxxxxxxxxxxxxxx
>>> >>> >> https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>>> >>> >
>>> >>> >
>>> >>>
>>> >>> _______________________________________________
>>> >>> resiprocate-devel mailing list
>>> >>> resiprocate-devel@xxxxxxxxxxxxxxx
>>> >>> https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> resiprocate-devel mailing list
>>> >> resiprocate-devel@xxxxxxxxxxxxxxx
>>> >> https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>>> >
>>> >
>>
>
>