[ndnSIM] Using the setExpiryTImer

Sun Nov 25 16:31:44 PST 2018

Hi all,

Thank you for all your support and guidance. I was not able to send Data
with “m_forwarder.onOutgoingData” instead of  “sendData” as stated before.
So, I changed the Strategy.cpp of the NFD and reinstalled everything so
that my separate repository is also able to use the updated Strategy.cpp.
In the Strategy.cpp I just commented out the
"pitEntry->deleteInRecord(outFace); ".

Now the multiple data produced are able to reach the consumer with just one
interest.

Best Regards
Ashish Pradhan,

On Sun, Nov 25, 2018 at 6:58 PM Ashish Pradhan <ashishpradhan1162 at gmail.com>
wrote:

> This is my sendData reimplementation code(just commented the 2 lines):
> void CustomStrategy::sendData(const shared_ptr<pit::Entry>& pitEntry,
> const Data& data, const Face& outFace)
> {
>       //BOOST_ASSERT(pitEntry->getInterest().matchesData(data));
>
>       // delete the PIT entry's in-record based on outFace,
>       // since Data is sent to outFace from which the Interest was received
>       //pitEntry->deleteInRecord(outFace);
>       NFD_LOG_INFO("pitEntry not deleted");
>
>       Strategy::m_forwarder.onOutgoingData(data,
> *const_pointer_cast<Face>(outFace.shared_from_this()));
> }
> I get this error : error: ‘nfd::Forwarder& nfd::fw::Strategy::m_forwarder’
> is private within this context
>
> Best Regards,
> Ashish Pradhan
>
>
> On Sun, Nov 25, 2018 at 6:35 PM Ashish Pradhan <
> ashishpradhan1162 at gmail.com> wrote:
>
>> Hello Xinyu,
>>
>> Thank you for reaching out. Trying to send Data with “m_forwarder.
>> onOutgoingData” gives an error of m_forwarder being a private member.
>>
>> The multiple data objects have the same name.
>>
>>
>>
>> On Sun, Nov 25, 2018 at 6:17 PM Xinyu Ma <bitmxy at gmail.com> wrote:
>>
>>> Hello, Pradhan
>>>
>>> On Nov 24, 2018, at 9:38 PM, Ashish Pradhan <ashishpradhan1162 at gmail.com>
>>> wrote:
>>>
>>> Can't this be done simply by making a custom strategy and using the
>>> setExpiryTimer? If not, where is the setExpiryTimer useful?
>>>
>>> In the documentation it is mentioned that "If the strategy wishes to
>>> collect responses from additional upstream nodes, it should invoke
>>> setExpiryTimer within this function to prolong the PIT entry lifetime.
>>> If a Data arrives from another upstream during the extended PIT entry
>>> lifetime, this trigger will be invoked again. At that time, this function
>>> must invoke setExpiryTimer again to continue collecting more responses."
>>>
>>> http://ndnsim.net/current/doxygen/classnfd_1_1fw_1_1Strategy.html#a97b4f1e5496c4dd08cc17b5d3d265f08
>>>
>>> Shouldn't this simply work?
>>>
>>>
>>> Yes, this works if you only want to "prolong the PIT entry lifetime”
>>> and “collecting more responses” at this node.
>>> But what you need is to continue forwarding data, which means the
>>> in-record of PIT entry should not be deleted.
>>> In-records are deleted in the “Strategy::sendData” function, which is
>>> called by “Strategy::afterReceiveData” after “beforeSatisfyInterest”
>>> So if you don’t want to hack NFD, you can override “afterReceiveData”
>>> and try to send Data with “m_forwarder.onOutgoingData” but not
>>>  “sendData”.
>>>
>>> On Sun, Nov 25, 2018 at 2:31 PM Lixia Zhang <lixia at cs.ucla.edu> wrote:
>>>
>>>>
>>>>
>>>> On Nov 24, 2018, at 9:20 PM, Ashish Pradhan <
>>>> ashishpradhan1162 at gmail.com> wrote:
>>>>
>>>> No, the producers produces multiple data objects(not segmenting into
>>>> multiple data packets).
>>>>
>>>>
>>>> no difference: the producer knows how many total packets it produces.
>>>>
>>>>
>>> Could you please tell me whether the multiple data objects have the same
>>> name?
>>> If their names are different, I think you can make it with out keep the
>>> PIT entry.
>>>
>>> Best wishes,
>>> Xinyu Ma.
>>>
>>>
>>>>
>>>> On Sun, Nov 25, 2018 at 2:15 PM Lixia Zhang <lixia at cs.ucla.edu> wrote:
>>>>
>>>>>
>>>>> On Nov 24, 2018, at 4:08 PM, Ashish Pradhan <
>>>>> ashishpradhan1162 at gmail.com> wrote:
>>>>>
>>>>> Hi Xinyu,
>>>>>
>>>>> Thank you for your reply.
>>>>>
>>>>> I am fully aware of the One-Interest-One-Data behavior. However, I
>>>>> have a custom app(a producer) where it produces multiple data for a single
>>>>> interest.
>>>>>
>>>>>
>>>>> I would like to better understand what is going on here: do you mean
>>>>> the producer app generates a data object which needs to be segmented into
>>>>> multiple data packets?
>>>>>
>>>>> If so: yes one can find a way to hack the code to allow the bread
>>>>> crumb of one Interest to retrieve multiple data packets, but it is unclear
>>>>> to me a good idea to use across a network
>>>>> (one interest can retrieve the first data packet, which can carry "FinalBlockId"
>>>>> to inform the consumer how many more data packets to fetch).
>>>>>
>>>>> Lixia
>>>>>
>>>>> Then I want all the produced data to reach the consumer. So for that,
>>>>> I am implementing a custom strategy where the PIT entry lifetime of the
>>>>> nodes are extended after it receives the first data from the producer. I
>>>>> have followed the ndnSIM API documentation for it.
>>>>>
>>>>> beforeSatisfyInterest documentation:
>>>>>
>>>>> http://ndnsim.net/current/doxygen/classnfd_1_1fw_1_1Strategy.html#a97b4f1e5496c4dd08cc17b5d3d265f08
>>>>>
>>>>> setExpiryTimer documentation:
>>>>>
>>>>> http://ndnsim.net/current/doxygen/classnfd_1_1fw_1_1Strategy.html#a967ad88184231f79b245ce202e9d4ea7
>>>>>
>>>>> Best regards,
>>>>> Ashish Pradhan
>>>>>
>>>>>
>>>>>
>>>>> On Sun, Nov 25, 2018 at 2:21 AM Xinyu Ma <bitmxy at gmail.com> wrote:
>>>>>
>>>>>> Hello, Pradhan
>>>>>>
>>>>>> I’m sorry I don’t understand why you want to extend the PIT entry’s
>>>>>> lifetime and what you mean by “data response other than the first one”.
>>>>>> NDN follows One-Interest-One-Data, so the PIT entry should be deleted
>>>>>> after receiving the data.
>>>>>> You can send another Interest if you still want the PIT entry to be
>>>>>> there.
>>>>>>
>>>>>> Best,
>>>>>> Xinyu Ma.
>>>>>>
>>>>>> On Nov 24, 2018, at 6:20 AM, Ashish Pradhan <
>>>>>> ashishpradhan1162 at gmail.com> wrote:
>>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I am trying to use the setExpiryTimer to extend the PIT entry's
>>>>>> lifetime. However the data response other than the first one is not being
>>>>>> forwarded back to the consumer. I have included the setExpiryTimer in the
>>>>>> beforeSatisfyInterest function as follows:
>>>>>> "NFD_LOG_DEBUG("beforeSatisfyInterest pitEntry=" <<
>>>>>> pitEntry->getName() <<
>>>>>>                 " inFace=" << inFace.getId() << " data=" <<
>>>>>> data.getName());
>>>>>>
>>>>>>   this->Strategy::setExpiryTimer(pitEntry,
>>>>>> ndn::time::milliseconds(100));"
>>>>>>
>>>>>> Is there any thing that needs to be added?
>>>>>>
>>>>>> After looking at the sendData function there is this line
>>>>>> "pitEntry->deleteInRecord(outFace);". If it is deleting the inRecord how
>>>>>> does the setExpiryTimer help to preserve the entry?
>>>>>>
>>>>>> Best regards,
>>>>>> Ashish Pradhan
>>>>>>
>>>>>> _______________________________________________
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>>>>>>
>>>>>>
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