[Ndn-interest] download a file using PyNDN
Ishita Dasgupta
ishita.dasgupta at gmail.com
Wed May 31 08:14:13 PDT 2017
Hi Jeff,
I have got it working! Let me know if my procedure to extract the version
number by sending a sample interest packet and receiving a sample data
packet is correct or is there a simpler method to do it?
Regards,
Ishita Dasgupta
*Graduate Student**College of Information and Computer Sciences*
*,UMass Amherst*
*Email*: ishitadg at cs.umass.edu
On Wed, May 31, 2017 at 10:46 AM, Ishita Dasgupta <ishita.dasgupta at gmail.com
> wrote:
> Hi Jeff,
>
> To extract the current version, I express an interest on the face and
> extract the version from the data packet received. Then use this version to
> extract our data in segments using segment fetcher.
> The main code lines look something like this
>
>
>> name = Name(url)
>> face.expressInterest(name, counter.onData, counter.onTimeout)
>>
>>
>> while counter._callbackCount < 1:
>> face.processEvents()
>> face.shutdown()
>> name = Name(url+version)
>> dump("Express name ", name.toUri())
>> interest = Interest(name)
>> interest.setInterestLifetimeMilliseconds(1000)
>> SegmentFetcher.fetch(face, interest, None, counter.onComplete,
>> counter.onError)
>> while counter._callbackCount < 2:
>> face.processEvents()
>>
>> face.shutdown()
>
>
> But for the first interest, i receive a "broken" version number
> (
> %FDY.%CF-
> )
> ? which is why the segment fetcher doesn't work (?)
>
> 1496241583.724584 From: 192.1.242.150, To: 192.1.242.151, Tunnel Type:
>> TCP, INTEREST: /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_
>> 05_09.mpd?ndn.MustBeFresh=1&ndn.Nonce=1500003601
>> 1496241583.734759 From: 192.1.242.151, To: 192.1.242.150, Tunnel Type:
>> TCP, DATA: /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_
>> 05_09.mpd/%C1.FS.file/%FDY.%CF-
>
>
> Is this how I should go about to fetch the version number before
> expressing the interest or is there a simpler method?
>
> Regards,
> Ishita Dasgupta
>
> *Graduate Student**College of Information and Computer Sciences*
> *,UMass Amherst*
> *Email*: ishitadg at cs.umass.edu
>
> On Fri, May 26, 2017 at 2:39 PM, Thompson, Jeff <jefft0 at remap.ucla.edu>
> wrote:
>
>> That’s right. The names of the actual segment Data packets should be
>>
>> /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09.mpd/%FDY%
>> 28Q8/%00%00
>> /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09.mpd/%FDY%
>> 28Q8/%00%01
>> /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09.mpd/%FDY%
>> 28Q8/%00%02
>>
>> etc., up to the maximum segment number. You give SegmentFetcher the name
>> without the final segment number component, and it adds the segment number
>> component as it fetches each one.
>>
>> - Jeff T
>>
>> From: Ishita Dasgupta <ishita.dasgupta at gmail.com>
>> Date: Friday, May 26, 2017 at 11:35:00
>>
>> To: Jeff Thompson <jefft0 at remap.ucla.edu>
>> Cc: "ndn-interest at lists.cs.ucla.edu" <ndn-interest at lists.cs.ucla.edu>
>> Subject: Re: [Ndn-interest] download a file using PyNDN
>>
>> So, just so that I understand this correctly: " %FDY%28Q8 " is the
>> version component of the all data packet segments representing the file.
>> And then the Segment Fetcher program sequentially downloads the segments
>> individually (and I don't need to worry about the segment numbers?)
>>
>> Regards,
>> Ishita Dasgupta
>>
>> *Graduate Student **College of Information and Computer Sciences*
>> *, UMass Amherst*
>> *Email*: ishitadg at cs.umass.edu
>>
>> On Fri, May 26, 2017 at 2:31 PM, Thompson, Jeff <jefft0 at remap.ucla.edu>
>> wrote:
>>
>>> Please try the following: Don’t add the line to set the exclude filter,
>>> and change the name to include the version number (without “%C1.FS.file”):
>>>
>>> name3 = Name("/ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09
>>> .mpd/%FDY%28Q8”)
>>>
>>> The reason is that the segment component comes after the version
>>> component “/%FDY%28Q8”.
>>>
>>> - Jeff T
>>>
>>> From: Ishita Dasgupta <ishita.dasgupta at gmail.com>
>>> Date: Friday, May 26, 2017 at 11:22:00
>>>
>>> To: Jeff Thompson <jefft0 at remap.ucla.edu>
>>> Cc: "ndn-interest at lists.cs.ucla.edu" <ndn-interest at lists.cs.ucla.edu>
>>> Subject: Re: [Ndn-interest] download a file using PyNDN
>>>
>>> Hi Jeff,
>>>
>>> Now it would not return any Data packet at all.
>>> At consumer(ndndump):
>>>
>>>> 1495818158.862071 From: 192.1.242.150, To: 192.1.242.151, Tunnel Type:
>>>> TCP, INTEREST: /ndn/broadcast/ndnfs/BigBuckBu
>>>> nny_4s_simple_2014_05_09.mpd?ndn.ChildSelector=1&ndn.MustBeF
>>>> resh=1&ndn.InterestLifetime=1000&ndn.Nonce=1259570516&ndn.
>>>> Exclude=%C1.FS.file
>>>
>>> <NO DATA PACKET IN RESPONSE>
>>>
>>>
>>> Regards,
>>> Ishita Dasgupta
>>>
>>> *Graduate Student **College of Information and Computer Sciences*
>>> *, UMass Amherst*
>>> *Email*: ishitadg at cs.umass.edu
>>>
>>> On Fri, May 26, 2017 at 12:54 PM, Thompson, Jeff <jefft0 at remap.ucla.edu>
>>> wrote:
>>>
>>>> After
>>>>
>>>> interest = Interest(name3)
>>>>
>>>> try adding
>>>>
>>>> interest.getExclude().appendComponent(Name("%C1.FS.file")[0])
>>>>
>>>> This is because NDNFS not only serves the Data packet segments of the
>>>> file, but a “meta info” packet where the name has the component
>>>> “"%C1.FS.file”. The code above should exclude it.
>>>>
>>>> Let us know,
>>>> - Jeff T
>>>>
>>>> From: Ishita Dasgupta <ishita.dasgupta at gmail.com>
>>>> Date: Friday, May 26, 2017 at 9:38:00
>>>> To: Jeff Thompson <jefft0 at remap.ucla.edu>
>>>> Cc: "ndn-interest at lists.cs.ucla.edu" <ndn-interest at lists.cs.ucla.edu>
>>>>
>>>> Subject: Re: [Ndn-interest] download a file using PyNDN
>>>>
>>>> Hi Jeff,
>>>>
>>>> I have a file test.txt being served on my ndnfs server. Prefix:
>>>> /ndn/broadcast/ndnfs
>>>> I implement SegmentFetcher in the following way and print content and
>>>> error message
>>>>
>>>> name3 = Name(url)
>>>>> dump("Express name ", name3.toUri())
>>>>> interest = Interest(name3)
>>>>> dump(interest.toUri())
>>>>> interest.setInterestLifetimeMilliseconds(1000)
>>>>> SegmentFetcher.fetch(face, interest, None, counter.onComplete,
>>>>> counter.onError)
>>>>
>>>>
>>>> This is what i get:
>>>>
>>>>> /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09.mpd?n
>>>>> dn.MustBeFresh=true
>>>>> onError
>>>>> 2
>>>>> Got an unexpected packet without a segment number:
>>>>> /ndn/broadcast/ndnfs/BigBuckBunny_4s_simple_2014_05_09.mpd/%
>>>>> C1.FS.file/%FDY%28Q8
>>>>
>>>>
>>>> When I do an ndndump on the consumer, I see:
>>>>
>>>>> 1495816236.074843 From: 192.1.242.150, To: 192.1.242.151, Tunnel Type:
>>>>> TCP, INTEREST: /ndn/broadcast/ndnfs/BigBuckBu
>>>>> nny_4s_simple_2014_05_09.mpd?ndn.ChildSelector=1&ndn.MustBeF
>>>>> resh=1&ndn.InterestLifetime=1000&ndn.Nonce=3797640908
>>>>
>>>>
>>>>
>>>> 1495816236.085709 From: 192.1.242.151, To: 192.1.242.150, Tunnel Type:
>>>>> TCP, DATA: /ndn/broadcast/ndnfs/BigBuckBu
>>>>> nny_4s_simple_2014_05_09.mpd/%C1.FS.file/%FDY%28Q8
>>>>
>>>>
>>>> I thought fetching segment number was internally done in your Segment
>>>> Fetcher util. Do I need to implement it some way on my end as well?
>>>>
>>>> Regards,
>>>> Ishita Dasgupta
>>>>
>>>> *Graduate Student **College of Information and Computer Sciences*
>>>> *, UMass Amherst*
>>>> *Email*: ishitadg at cs.umass.edu
>>>>
>>>> On Thu, May 25, 2017 at 2:15 PM, Thompson, Jeff <jefft0 at remap.ucla.edu>
>>>> wrote:
>>>>
>>>>> Hi Ishita,
>>>>>
>>>>> We have NDNFS producing sample data at memoria.ndn.ucla.edu. The
>>>>> PyNDN code below uses the SegmentFetcher to fetch the segments of a file (a
>>>>> JavaScript file). NDNFS has split the file into 12 segments, which
>>>>> SegmentFetcher retrieves to supply the content to the callback.
>>>>> SegmentFetcher documentation is here:
>>>>> https://github.com/named-data/PyNDN2/blob/master/python/pynd
>>>>> n/util/segment_fetcher.py#L142
>>>>>
>>>>> - Jeff T
>>>>>
>>>>> import time, sys
>>>>> from pyndn import Name, Interest, Face
>>>>> from pyndn.util import SegmentFetcher
>>>>>
>>>>> face = Face("memoria.ndn.ucla.edu")
>>>>> SegmentFetcher.fetch(face, Interest(Name(
>>>>> "/ndn/edu/ucla/remap/demo/ndn-js-test/named-data.net/wp-incl
>>>>> udes/js/jquery/jquery.js/%FDX%DC5B")),
>>>>> None, lambda content: sys.stdout.write(content.toRawStr()),
>>>>> lambda errorCode, message: sys.stdout.write("Got error " + message))
>>>>>
>>>>> while True:
>>>>> face.processEvents()
>>>>> time.sleep(0.01)
>>>>>
>>>>>
>>>>> From: Ishita Dasgupta <ishita.dasgupta at gmail.com>
>>>>> Date: Thursday, May 25, 2017 at 6:00:00
>>>>> To: Jeff Thompson <jefft0 at remap.ucla.edu>, "
>>>>> ndn-interest at lists.cs.ucla.edu" <ndn-interest at lists.cs.ucla.edu>
>>>>> Subject: Re: [Ndn-interest] download a file using PyNDN
>>>>>
>>>>> Hi Jeff,
>>>>>
>>>>> Yes
>>>>> , the producer is responding to Interests with Data packets
>>>>> representing the file. I run NDNFS on the producer.
>>>>>
>>>>>
>>>>> On Wed, May 24, 2017 at 4:35 PM Thompson, Jeff <jefft0 at remap.ucla.edu>
>>>>> wrote:
>>>>>
>>>>>> Hi Ishta,
>>>>>>
>>>>>> In NDN, there is a producer and consumer. The consumer sends an
>>>>>> Interest and the producer (or a cache in the network) responds with a Data
>>>>>> packet. When you say “an entire file from an NDN server” I assume you mean
>>>>>> a producer that is responding to Interests with Data packets representing
>>>>>> the file. What producer software is running on the server?
>>>>>>
>>>>>> - Jeff T
>>>>>>
>>>>>> From: Ndn-interest <ndn-interest-bounces at lists.cs.ucla.edu> on
>>>>>> behalf of Ishita Dasgupta <ishita.dasgupta at gmail.com>
>>>>>> Date: Wednesday, May 24, 2017 at 8:29:00
>>>>>> To: "ndn-interest at lists.cs.ucla.edu" <ndn-interest at lists.cs.ucla.edu>
>>>>>> Subject: [Ndn-interest] download a file using PyNDN
>>>>>>
>>>>>> Hi All,
>>>>>>
>>>>>> Has anybody used PyNDN to download an entire file from an ndn server?
>>>>>> I see or receive jibberish data in form of one data packet but don't
>>>>>> seem to copying the exact content of the file(no matter the size, i.e
>>>>>> irrespective of the fact that the file gets divided to multiple segments or
>>>>>> just one segment).
>>>>>> Any guidance with this would be helpful.
>>>>>>
>>>>>> Thanks,
>>>>>> Ishita
>>>>>>
>>>>>
>>>>
>>>
>>
>
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