[Ndn-interest] download a file using PyNDN
Ishita Dasgupta
ishita.dasgupta at gmail.com
Wed May 31 07:46:23 PDT 2017
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.
>>> MustBeFresh=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/BigBuckBunny_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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