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#!/usr/bin/perl |
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|
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# "HTTP Push" is not readily attainable, so instead we will simulate it using a |
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# long-pull, aka "Comet". The client browser simply opens an HTTP connection to |
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# the server and waits for a response. The server doesn't respond until there |
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# is some event (here a new message), giving the appearance of HTTP-push. |
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# |
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# Each user gets three continuations for these three cases: |
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# |
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# - Initial load or reload of the page |
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# - Sending a message (uses AJAX on the client) |
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# - Recieving messages (uses COMET on the client) |
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|
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use strict; |
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use lib 'lib'; |
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use Continuity; |
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use Continuity::REPL; |
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use Data::Dump qw/dump/; |
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|
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use View; |
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|
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use Template::Declare; |
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use Template::Declare::Tags; # defaults to 'HTML' |
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Template::Declare->init( roots => ['View']); |
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warn "templates = ",dump( Template::Declare->templates ); |
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|
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my @messages; # Global (shared) list of messages |
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my $got_message; # Flag to indicate that there is a new message to display |
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|
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use vars qw( $repl $server @messages ); |
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$repl = Continuity::REPL->new; |
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|
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$server = Continuity->new( |
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port => 16001, |
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path_session => 1, |
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cookie_session => 'sid', |
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); |
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$server->debug_level( 2 ); |
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|
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$server->loop; |
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|
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# This is the main entrypoint. We are looking for one of three things -- a |
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# pushstream, a sent message, or a request for the main HTML. We delegate each |
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# of these cases, none of which will return (they all loop forever). |
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sub main { |
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my ($req) = @_; |
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|
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my $path = $req->request->url->path; |
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print STDERR "Path: '$path'\n"; |
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|
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warn $req->request->header('User_Agent'); |
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#warn dump( $req ); |
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|
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# If this is a request for the pushtream, then give them that |
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if($path =~ /pushstream/) { |
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pushstream($req); |
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} |
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|
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# If they are sending us a message, we give them a thread for that too |
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if($path =~ /sendmessage/) { |
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send_message($req); |
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} |
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|
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# Otherwise, lets give them the base page |
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send_base_page($req); |
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} |
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|
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# Here we accept a connection to the browser, and keep it open. Meanwhile we |
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# watch the global $got_message variable, and when it gets touched we send off |
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# the list of messages through the held-open connection. Then we let the |
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# browser open a new connection and begin again. |
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sub pushstream { |
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my ($req) = @_; |
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# Set up watch event -- this will be triggered when $got_message is written |
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my $w = Coro::Event->var(var => \$got_message, poll => 'w'); |
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while(1) { |
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print STDERR "**** GOT MESSAGE, SENDING ****\n"; |
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my $log = join "<br>", @messages; |
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$req->print($log); |
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$req->next; |
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print STDERR "**** Waiting for got_message indicator ****\n"; |
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$w->next; |
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} |
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} |
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|
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|
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# Watch for the user to send us a message. As soon as we get it, we add it to |
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# our list of messages and touch the $got_message flag to let all the |
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# pushstreams know. |
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sub send_message { |
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my ($req) = @_; |
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while(1) { |
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my $msg = $req->param('message'); |
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my $name = $req->param('username'); |
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if($msg) { |
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unshift @messages, "$name: $msg"; |
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pop @messages if $#messages > 15; # Only keep the recent 15 messages |
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} |
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$got_message = 1; |
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$req->print("Got it!"); |
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$req->next; |
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} |
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} |
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|
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# This isn't a pushstream, nor a new message. It is just the main page. We loop |
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# in case they ask for it multiple times :) |
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sub send_base_page { |
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my ($req) = @_; |
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while(1) { |
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warn "base page"; |
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$req->print( Template::Declare->show( 'user' ) ); |
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=for later |
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$req->print(qq{ |
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<html> |
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<head> |
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<title>Chat!</title> |
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<script src="jquery.js" type="text/javascript"></script> |
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<script src="chat-ajax-push.js" type="text/javascript"></script> |
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</head> |
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<body> |
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<form id=f> |
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<input type=text id=username name=usernamename size=10> |
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<input type=text id=message name=message size=50> |
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<input type=submit name="sendbutton" value="Send" id="sendbutton"> |
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<span id=status></span> |
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</form> |
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<br> |
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<div id=log>-- no messages yet --</div> |
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</body> |
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</html> |
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}); |
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=cut |
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$req->next; |
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} |
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} |
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|
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