trunk/Meteor/Channel.pm

#!/usr/bin/perl -w
###############################################################################
#   Meteor
#   An HTTP server for the 2.0 web
#   Copyright (c) 2006 contributing authors
#
#   Subscriber.pm
#
#       Description:
#       A Meteor Channel
#
###############################################################################
#
#   This program is free software; you can redistribute it and/or modify it
#   under the terms of the GNU General Public License as published by the Free
#   Software Foundation; either version 2 of the License, or (at your option)
#   any later version.
#
#   This program is distributed in the hope that it will be useful, but WITHOUT
#   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#   FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
#   more details.
#
#   You should have received a copy of the GNU General Public License along
#   with this program; if not, write to the Free Software Foundation, Inc.,
#   59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
#   For more information visit www.meteorserver.org
#
###############################################################################

package Meteor::Channel;
###############################################################################
# Configuration
###############################################################################
        
        use strict;
        
        use Meteor::Message;
        
        our %Channels=();
        our $MessageID=0;

###############################################################################
# Class methods
###############################################################################
sub channelWithName {
        my $class=shift;
        my $channelName=shift;
        my $avoidCreation=shift;
        
        unless(exists($Channels{$channelName}))
        {
                return undef if($avoidCreation);
                #
                # Create new channel
                #
                $Channels{$channelName}=$class->newChannel($channelName);
                
                &::syslog('debug',"New channel $channelName");
        }
        
        return $Channels{$channelName};
}

sub listChannels {
        my $class=shift;
        
        my $list='';
        foreach my $channelName (sort keys %Channels)
        {
                my $channel=$Channels{$channelName};
                
                $list.=$channelName.'('.$channel->messageCount().'/'.$channel->subscriberCount().")$::CRLF";
        }
        
        $list;
}

sub listChannelsUsingTemplate {
        my $class=shift;
        my $template=shift;
        
        return '' unless(defined($template) && $template ne '');
        
        my $list='';
        foreach my $channelName (sort keys %Channels)
        {
                my $channel=$Channels{$channelName};
                
                $list.=$channel->descriptionWithTemplate($template);
        }
        
        $list;
}

sub deleteChannel {
        my $class=shift;
        my $channelName=shift;
        
        delete($Channels{$channelName});
}

sub trimMessageStoresByTimestamp {
        my $class=shift;
        my $minTimeStamp=shift;
        
        return unless($minTimeStamp);
        
        map { $_->trimMessageStoreByTimestamp($minTimeStamp) } (values %Channels);
}

sub clearAllBuffers {
        my $class=shift;
        
        map { $_->clearBuffer() } (values %Channels);
}

sub numChannels {
        
        return scalar(keys %Channels);
}

###############################################################################
# Factory methods
###############################################################################
sub new {
        #
        # Create a new empty instance
        #
        my $class=shift;
        
        my $obj={};
        
        bless($obj,$class);
}
        
sub newChannel {
        #
        # new instance from new server connection
        #
        my $self=shift->new();
        
        my $name=shift;
        $self->{'name'}=$name;
        
        $self->{'subscribers'}=[];
        $self->{'messages'}=[];
        
        $self;
}

sub DESTROY {
        my $self=shift;
        
        my @subscribers=@{$self->{'subscribers'}};
        map { $_->closeChannel($self->{'name'}) } @subscribers;
}

###############################################################################
# Instance methods
###############################################################################
sub name {
        shift->{'name'};
}

sub addSubscriber {
        my $self=shift;
        my $subscriber=shift;
        my $startId=shift;
        my $persist=shift;
        my $mode=shift || '';
        my $userAgent=shift || '';
        
        # Note: negative $startId means go back that many messages
        
        push(@{$self->{'subscribers'}},$subscriber) if($persist);
        
        &::syslog('info','',
                'joinchannel',
                $subscriber->{'subscriberID'},
                $self->{'name'},
                $mode,
                $startId,
                $userAgent
        );
        
        my $startIndex=$self->indexForMessageID($startId);
        return unless(defined($startIndex));
        
        my $msgCount=scalar(@{$self->{'messages'}});
        my $txt='';
        
        $startIndex=0 if($startIndex<0);
        
        if($startIndex<$msgCount)
        {
                $subscriber->sendMessages(@{$self->{'messages'}}[$startIndex,$msgCount-1]);
        }
}

sub removeSubscriber {
        my $self=shift;
        my $subscriber=shift;
        my $reason=shift ||'unknown';
        
        my $idx=undef;
        for(my $i=0;$i<scalar(@{$self->{'subscribers'}});$i++)
        {
                if($self->{'subscribers'}->[$i]==$subscriber)
                {
                        $idx=$i;
                        last;
                }
        }
        
        if(defined($idx))
        {
                splice(@{$self->{'subscribers'}},$idx,1);
                
                &::syslog('info','',
                        'leavechannel',
                        $subscriber->{'subscriberID'},
                        $self->{'name'},
                        $subscriber->{'ConnectionStart'},
                        $subscriber->{'MessageCount'},
                        $subscriber->{'bytesWritten'},
                        $reason
                );
        }
        
        $self->checkExpiration();
}

sub subscriberCount {
        my $self=shift;
        
        scalar(@{$self->{'subscribers'}});
}

sub addMessage {
        my $self=shift;
        my $messageText=shift;
        
        my $message=Meteor::Message->newWithID($MessageID++);
        $message->setText($messageText);
        $message->setChannelName($self->{'name'});
        push(@{$self->{'messages'}},$message);
        
        $self->trimMessageStoreBySize();
        
        map { $_->sendMessages($message) } @{$self->{'subscribers'}};
        
        $message;
}

sub messageCount {
        my $self=shift;
        
        scalar(@{$self->{'messages'}});
}

sub trimMessageStoreBySize {
        my $self=shift;
        
        my $numMessages=scalar(@{$self->{'messages'}});
        
        if($numMessages>$::CONF{'MaxMessagesPerChannel'})
        {
                splice(@{$self->{'messages'}},0,-$::CONF{'MaxMessagesPerChannel'});
        }
}

sub trimMessageStoreByTimestamp {
        my $self=shift;
        my $ts=shift;
        
        while(scalar(@{$self->{'messages'}})>0 && $self->{'messages'}->[0]->timestamp()<$ts)
        {
                my $msg=shift(@{$self->{'messages'}});
        }
        
        $self->checkExpiration();
}

sub clearBuffer {
        my $self=shift;
        
        $self->{'messages'}=[];
        
        $self->checkExpiration();
}

sub checkExpiration {
        my $self=shift;
        
        if($self->messageCount()==0 && $self->subscriberCount()==0)
        {
                my $name=$self->name();
                &::syslog('debug',"Channel expired: $name");
                $self->deleteChannel($name);
        }
}

sub indexForMessageID {
        my $self=shift;
        my $id=shift;
        
        # the messages is always sorted by ID, so we can
        # use a binary search to find the message.
        # return undef if there are no messages or the
        # ID is that of the last message.
        # Otherwise return the ID of the found message
        # of if no message with that ID exists the one
        # with the next higher ID
        #
        return undef unless(defined($id));
        
        my $numMessages=scalar(@{$self->{'messages'}});
        
        return undef unless($numMessages);
        return -1 unless($id ne '');
        
        # Note: negative $id means go back that many messages
        return $numMessages+$id if($id<0);
        
        my $low=0;
        my $high=$numMessages-1;
        my $mid;
        my $cond;
        while($low<=$high)
        {
                $mid=($low+$high)>>1;
                $cond=$id <=> $self->{'messages'}->[$mid]->id();
                if($cond<0)
                {
                        $high=$mid-1;
                }
                elsif($cond>0)
                {
                        $low=$mid+1;
                }
                else
                {
                        return $mid;
                }
        }
        
        return undef if($low>=$numMessages);
        
        return $low;
}

sub lastMsgID {
        my $self=shift;
        
        my $numMessages=scalar(@{$self->{'messages'}});
        
        return 'undefined' unless($numMessages>0);
        
        @{$self->{'messages'}}[-1]->id();
}

sub descriptionWithTemplate {
        my $self=shift;
        my $template=shift;
        
        $template=~s/~([a-zA-Z0-9_]*)~/
                if(!defined($1) || $1 eq '')
                {
                        '~';
                }
                elsif($1 eq 'messageCount')
                {
                        $self->messageCount();
                }
                elsif($1 eq 'subscriberCount')
                {
                        $self->subscriberCount();
                }
                elsif($1 eq 'lastMsgID')
                {
                        $self->lastMsgID();
                }
                
                elsif(exists($self->{$1}))
                {
                        $self->{$1};
                }
                else
                {
                        '';
                }
        /gex;
        
        $template;
}

1;
############################################################################EOF
1	knops.gerd	11	#!/usr/bin/perl -w
2			###############################################################################
3			# Meteor
4			# An HTTP server for the 2.0 web
5			# Copyright (c) 2006 contributing authors
6			#
7			# Subscriber.pm
8			#
9			# Description:
10			# A Meteor Channel
11			#
12			###############################################################################
13			#
14			# This program is free software; you can redistribute it and/or modify it
15			# under the terms of the GNU General Public License as published by the Free
16			# Software Foundation; either version 2 of the License, or (at your option)
17			# any later version.
18			#
19			# This program is distributed in the hope that it will be useful, but WITHOUT
20			# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21			# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22			# more details.
23			#
24			# You should have received a copy of the GNU General Public License along
25			# with this program; if not, write to the Free Software Foundation, Inc.,
26			# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27			#
28			# For more information visit www.meteorserver.org
29			#
30			###############################################################################
31
32			package Meteor::Channel;
33			###############################################################################
34			# Configuration
35			###############################################################################
36
37			use strict;
38
39			use Meteor::Message;
40
41			our %Channels=();
42			our $MessageID=0;
43
44			###############################################################################
45			# Class methods
46			###############################################################################
47			sub channelWithName {
48			my $class=shift;
49			my $channelName=shift;
50			my $avoidCreation=shift;
51
52			unless(exists($Channels{$channelName}))
53			{
54			return undef if($avoidCreation);
55			#
56			# Create new channel
57			#
58			$Channels{$channelName}=$class->newChannel($channelName);
59
60			&::syslog('debug',"New channel $channelName");
61			}
62
63			return $Channels{$channelName};
64			}
65
66			sub listChannels {
67			my $class=shift;
68
69			my $list='';
70			foreach my $channelName (sort keys %Channels)
71			{
72			my $channel=$Channels{$channelName};
73
74			$list.=$channelName.'('.$channel->messageCount().'/'.$channel->subscriberCount().")$::CRLF";
75			}
76
77			$list;
78			}
79
80	knops.gerd	45	sub listChannelsUsingTemplate {
81			my $class=shift;
82			my $template=shift;
83
84			return '' unless(defined($template) && $template ne '');
85
86			my $list='';
87			foreach my $channelName (sort keys %Channels)
88			{
89			my $channel=$Channels{$channelName};
90
91			$list.=$channel->descriptionWithTemplate($template);
92			}
93
94			$list;
95			}
96
97	knops.gerd	11	sub deleteChannel {
98			my $class=shift;
99			my $channelName=shift;
100
101			delete($Channels{$channelName});
102			}
103
104			sub trimMessageStoresByTimestamp {
105			my $class=shift;
106			my $minTimeStamp=shift;
107
108			return unless($minTimeStamp);
109
110			map { $_->trimMessageStoreByTimestamp($minTimeStamp) } (values %Channels);
111			}
112
113			sub clearAllBuffers {
114			my $class=shift;
115
116			map { $_->clearBuffer() } (values %Channels);
117			}
118
119	knops.gerd	25	sub numChannels {
120
121			return scalar(keys %Channels);
122			}
123
124	knops.gerd	11	###############################################################################
125			# Factory methods
126			###############################################################################
127			sub new {
128			#
129			# Create a new empty instance
130			#
131			my $class=shift;
132
133			my $obj={};
134
135			bless($obj,$class);
136			}
137
138			sub newChannel {
139			#
140			# new instance from new server connection
141			#
142			my $self=shift->new();
143
144			my $name=shift;
145			$self->{'name'}=$name;
146
147			$self->{'subscribers'}=[];
148			$self->{'messages'}=[];
149
150			$self;
151			}
152
153			sub DESTROY {
154			my $self=shift;
155
156			my @subscribers=@{$self->{'subscribers'}};
157	knops.gerd	13	map { $_->closeChannel($self->{'name'}) } @subscribers;
158	knops.gerd	11	}
159
160			###############################################################################
161			# Instance methods
162			###############################################################################
163			sub name {
164			shift->{'name'};
165			}
166
167			sub addSubscriber {
168			my $self=shift;
169			my $subscriber=shift;
170			my $startId=shift;
171			my $persist=shift;
172	knops.gerd	47	my $mode=shift \|\| '';
173			my $userAgent=shift \|\| '';
174	knops.gerd	11
175			# Note: negative $startId means go back that many messages
176
177			push(@{$self->{'subscribers'}},$subscriber) if($persist);
178
179	knops.gerd	47	&::syslog('info','',
180			'joinchannel',
181			$subscriber->{'subscriberID'},
182			$self->{'name'},
183			$mode,
184			$startId,
185			$userAgent
186			);
187
188	knops.gerd	11	my $startIndex=$self->indexForMessageID($startId);
189			return unless(defined($startIndex));
190
191			my $msgCount=scalar(@{$self->{'messages'}});
192			my $txt='';
193
194			$startIndex=0 if($startIndex<0);
195
196	knops.gerd	45	if($startIndex<$msgCount)
197	knops.gerd	11	{
198	knops.gerd	45	$subscriber->sendMessages(@{$self->{'messages'}}[$startIndex,$msgCount-1]);
199	knops.gerd	11	}
200			}
201
202			sub removeSubscriber {
203			my $self=shift;
204			my $subscriber=shift;
205	knops.gerd	47	my $reason=shift \|\|'unknown';
206	knops.gerd	11
207			my $idx=undef;
208			for(my $i=0;$i<scalar(@{$self->{'subscribers'}});$i++)
209			{
210			if($self->{'subscribers'}->[$i]==$subscriber)
211			{
212			$idx=$i;
213			last;
214			}
215			}
216
217			if(defined($idx))
218			{
219			splice(@{$self->{'subscribers'}},$idx,1);
220	knops.gerd	47
221			&::syslog('info','',
222			'leavechannel',
223			$subscriber->{'subscriberID'},
224			$self->{'name'},
225			$subscriber->{'ConnectionStart'},
226			$subscriber->{'MessageCount'},
227			$subscriber->{'bytesWritten'},
228			$reason
229			);
230	knops.gerd	11	}
231
232			$self->checkExpiration();
233			}
234
235			sub subscriberCount {
236			my $self=shift;
237
238			scalar(@{$self->{'subscribers'}});
239			}
240
241			sub addMessage {
242			my $self=shift;
243			my $messageText=shift;
244
245			my $message=Meteor::Message->newWithID($MessageID++);
246	knops.gerd	16	$message->setText($messageText);
247			$message->setChannelName($self->{'name'});
248	knops.gerd	11	push(@{$self->{'messages'}},$message);
249
250			$self->trimMessageStoreBySize();
251
252	knops.gerd	45	map { $_->sendMessages($message) } @{$self->{'subscribers'}};
253	knops.gerd	46
254			$message;
255	knops.gerd	11	}
256
257			sub messageCount {
258			my $self=shift;
259
260			scalar(@{$self->{'messages'}});
261			}
262
263			sub trimMessageStoreBySize {
264			my $self=shift;
265
266			my $numMessages=scalar(@{$self->{'messages'}});
267
268			if($numMessages>$::CONF{'MaxMessagesPerChannel'})
269			{
270			splice(@{$self->{'messages'}},0,-$::CONF{'MaxMessagesPerChannel'});
271			}
272			}
273
274			sub trimMessageStoreByTimestamp {
275			my $self=shift;
276			my $ts=shift;
277
278			while(scalar(@{$self->{'messages'}})>0 && $self->{'messages'}->[0]->timestamp()<$ts)
279			{
280			my $msg=shift(@{$self->{'messages'}});
281			}
282
283			$self->checkExpiration();
284			}
285
286			sub clearBuffer {
287			my $self=shift;
288
289			$self->{'messages'}=[];
290
291			$self->checkExpiration();
292			}
293
294			sub checkExpiration {
295			my $self=shift;
296
297			if($self->messageCount()==0 && $self->subscriberCount()==0)
298			{
299			my $name=$self->name();
300			&::syslog('debug',"Channel expired: $name");
301			$self->deleteChannel($name);
302			}
303			}
304
305			sub indexForMessageID {
306			my $self=shift;
307			my $id=shift;
308
309			# the messages is always sorted by ID, so we can
310			# use a binary search to find the message.
311			# return undef if there are no messages or the
312			# ID is that of the last message.
313			# Otherwise return the ID of the found message
314			# of if no message with that ID exists the one
315			# with the next higher ID
316			#
317			return undef unless(defined($id));
318
319	knops.gerd	46	my $numMessages=scalar(@{$self->{'messages'}});
320	knops.gerd	11
321			return undef unless($numMessages);
322			return -1 unless($id ne '');
323
324			# Note: negative $id means go back that many messages
325			return $numMessages+$id if($id<0);
326
327			my $low=0;
328			my $high=$numMessages-1;
329			my $mid;
330			my $cond;
331			while($low<=$high)
332			{
333			$mid=($low+$high)>>1;
334			$cond=$id <=> $self->{'messages'}->[$mid]->id();
335			if($cond<0)
336			{
337			$high=$mid-1;
338			}
339			elsif($cond>0)
340			{
341			$low=$mid+1;
342			}
343			else
344			{
345			return $mid;
346			}
347			}
348
349			return undef if($low>=$numMessages);
350
351			return $low;
352			}
353
354	knops.gerd	46	sub lastMsgID {
355			my $self=shift;
356
357			my $numMessages=scalar(@{$self->{'messages'}});
358
359			return 'undefined' unless($numMessages>0);
360
361			@{$self->{'messages'}}[-1]->id();
362			}
363
364	knops.gerd	45	sub descriptionWithTemplate {
365			my $self=shift;
366			my $template=shift;
367
368			$template=~s/~([a-zA-Z0-9_]*)~/
369			if(!defined($1) \|\| $1 eq '')
370			{
371			'~';
372			}
373			elsif($1 eq 'messageCount')
374			{
375			$self->messageCount();
376			}
377			elsif($1 eq 'subscriberCount')
378			{
379			$self->subscriberCount();
380			}
381	knops.gerd	46	elsif($1 eq 'lastMsgID')
382			{
383			$self->lastMsgID();
384			}
385
386	knops.gerd	45	elsif(exists($self->{$1}))
387			{
388			$self->{$1};
389			}
390			else
391			{
392			'';
393			}
394			/gex;
395
396			$template;
397			}
398
399	knops.gerd	11	1;
400	andrew.betts	3	############################################################################EOF