perl comet

Comet implementations for Perl

Bulgarian Perl Workshop 2013

Marian HackMan MarinovCo-founder and CEO of 1H [email protected]


What is Comet?

AJAX Push
Reverse AJAXTwo-way-webHTTP Streaming
HTTP Server Push

Replacing browser PULLwith server PUSH

A lot of names for the same technology :)


Implementations

Hidden iframeXMLHttpRequestlong polling with- AJAX- XMLHttpRequest- Script tag


StreamingShort pollingLong polling


Hidden iframe

Iframe sent as chunked blcok

Infinitely long

Works on every browser

Lacks reliable error handlingConnection state unavailable

Does not support cross domain accessBefore IE needs minimum 256bytes of data before executing anythingThe same issue is present in Safari


hackman@gamelon:~$ curl http://localhost:4670/push/12345/iframe/channel1

document.getElementById('counter').innerHTML = '1';document.getElementById('counter').innerHTML = '2';document.getElementById('counter').innerHTML = '3';document.getElementById('counter').innerHTML = '4';document.getElementById('counter').innerHTML = '5';document.getElementById('counter').innerHTML = '6';

Comet test Page

My counter:


XMLHttpRequest

The Ajax way of using CometReliable connection handlingConnection state information

Content-type: multipart/x-mixed-replace; boundary=NEXTPART\r\n\r\n

x-mixed-replace is invented by Netscape 1995since 2004 has support in Gecko browsersit is also included in IE 10 and newerDoes not support cross domain access


hackman@gamelon:~$ curl http://localhost:8000/

--NEXTPARTContent-type: text/plain

document.getElementById('counter').innerHTML = '0';--NEXTPARTContent-type: text/plain

document.getElementById('counter').innerHTML = '1';--NEXTPARTContent-type: text/plain

document.getElementById('counter').innerHTML = '2';--NEXTPART


Long Polling

XMLHttpRequest - creates a request- when all data is received- creates subsequent request

Does not support cross domain accessWorks on all browsers


Long Polling

tag- creates a script tag- when all data is received- creates new script tag

Supports cross domain accessWorks on all browsers


What Comet implementationswe have in Perl

MeteorStardust

Frameworks: - Mojolicious - PSGI
- Continuity

You can do it with CGI.pm but it is not advisable


Meteor

Stand alone web serverSupports: - iframe - xhrinteractive- simplepoll & smartpoll- longpoll- flash & flashloadvars

http://meteorserver.org/

Meteor



ADDMESSAGE chan msg COUNTSUBSCRIBERS chan LISTCHANNELS SHOWSTATS QUIT

Event controller commands



hackman@gamelon:~/Comet$ nc localhost 4671SHOWSTATSOKuptime: 279channel_count: 0subscriber_connections_accepted: 3controller_connections_accepted: 1total_inbound_bytes: 524total_outbound_bytes: 646documents_not_found: 3current_controllers: 1total_requests: 4current_subscribers: 0--EOT--ADDMESSAGE channel1 testingOK 0LISTCHANNELSOKchannel1(1/0)--EOT--ADDMESSAGE channel1 ddddddOK 1



$ curl http://localhost:4670/push/12345/iframe/channel1

window.onError = null;var domainparts = document.domain.split(".");document.domain = domainparts[domainparts.length-2]+". "+domainparts[domainparts.length-1];parent.Meteor.register(this);

ch("channel1", 1);

p(-1,"");p(-1,"");p(2,"channel1","fufufu");p(-1,"");^Chackman@gamelon:~$



$ curl http://localhost:4670/push/12345/xhrinteractive/channel1..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ch("channel1", 2);p(-1,"");p(-1,"");p(-1,"");p(-1,"");p(-1,"");p(3,"channel1","s1dasda");p(-1,""); p(-1,""); ^C hackman@gamelon:~$



$ curl http://localhost:4670/push/12345/simplepoll/channel1 ch("channel1", 3); hackman@gamelon:~$

$ curl http://localhost:4670/push/12345/smartpoll/channel1ch("channel1", 3); hackman@gamelon:~$

$ curl http://localhost:4670/push/12345/longpoll/channel1 ch("channel1", 3); p(-1,""); p(-1,""); p(-1,""); p(-1,""); p(4,"channel1","gtwedsada"); hackman@gamelon:~$



Stand alone web serverAlmost no documentationNo updates since 2011Supports: stream and longpoll

cpan Stardust

Stardust

remove With::Log from stardust.pl

cpan Stardust



$ curl -d 'm={ "type": "Test", "data": [1,2,3] }' http://localhost:5742/channel/foo/stream/foo//channel/foo/stream/foo/ not found.[root@gamelon script]# hackman@gamelon:~$$ curl -d 'm={ "type": "Test", "data": [1,2,3] }' http://localhost:5742/channel/foo$ curl http://localhost:5742/channel/foo[{"messages":[{"_ts":1360399562.89221,"data":[1,2,3],"type":"Test","_ch":"foo"}], "name":"foo","subscribers":[],"size":8,"i":1}]hackman@gamelon:~$

$ curl -d 'm={ "type": "Test", "data": [2,3] }' http://localhost:5742/channel/foo$ curl http://localhost:5742/channel/foo[{"messages":[{"_ts":1360399562.89221,"data":[1,2,3],"type":"Test","_ch":"foo"}, {"_ts":1360399605.81986,"data":[2,3],"type":"Test","_ch":"foo"}], "name":"foo","subscribers":[],"size":8,"i":2}]



Other Perl comet implementations: - POE-Component-Server-Bayeux - Tatsumaki

Additional readings: http://toroid.org/ams/etc/mojolicious-http-streaming http://infrequently.org/2006/03/comet-low-latency-data-for-the-browser/ http://showmetheco.de/articles/2011/2/diving-into-html5-with-websockets-and-perl.html



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More on the subject here: http://www.slideshare.net/simon/time-for-comet

My slides can be found here: http://www.slideshare.net/azilian/perl-comet

More on the subject here: http://www.slideshare.net/simon/time-for-comet


perl comet

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