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;
        
        # Note: negative $startId means go back that many messages
        
        push(@{$self->{'subscribers'}},$subscriber) if($persist);
        
        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 $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);
        }
        
        $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
173			# Note: negative $startId means go back that many messages
174
175			push(@{$self->{'subscribers'}},$subscriber) if($persist);
176
177			my $startIndex=$self->indexForMessageID($startId);
178			return unless(defined($startIndex));
179
180			my $msgCount=scalar(@{$self->{'messages'}});
181			my $txt='';
182
183			$startIndex=0 if($startIndex<0);
184
185	knops.gerd	45	if($startIndex<$msgCount)
186	knops.gerd	11	{
187	knops.gerd	45	$subscriber->sendMessages(@{$self->{'messages'}}[$startIndex,$msgCount-1]);
188	knops.gerd	11	}
189			}
190
191			sub removeSubscriber {
192			my $self=shift;
193			my $subscriber=shift;
194
195			my $idx=undef;
196			for(my $i=0;$i<scalar(@{$self->{'subscribers'}});$i++)
197			{
198			if($self->{'subscribers'}->[$i]==$subscriber)
199			{
200			$idx=$i;
201			last;
202			}
203			}
204
205			if(defined($idx))
206			{
207			splice(@{$self->{'subscribers'}},$idx,1);
208			}
209
210			$self->checkExpiration();
211			}
212
213			sub subscriberCount {
214			my $self=shift;
215
216			scalar(@{$self->{'subscribers'}});
217			}
218
219			sub addMessage {
220			my $self=shift;
221			my $messageText=shift;
222
223			my $message=Meteor::Message->newWithID($MessageID++);
224	knops.gerd	16	$message->setText($messageText);
225			$message->setChannelName($self->{'name'});
226	knops.gerd	11	push(@{$self->{'messages'}},$message);
227
228			$self->trimMessageStoreBySize();
229
230	knops.gerd	45	map { $_->sendMessages($message) } @{$self->{'subscribers'}};
231	knops.gerd	46
232			$message;
233	knops.gerd	11	}
234
235			sub messageCount {
236			my $self=shift;
237
238			scalar(@{$self->{'messages'}});
239			}
240
241			sub trimMessageStoreBySize {
242			my $self=shift;
243
244			my $numMessages=scalar(@{$self->{'messages'}});
245
246			if($numMessages>$::CONF{'MaxMessagesPerChannel'})
247			{
248			splice(@{$self->{'messages'}},0,-$::CONF{'MaxMessagesPerChannel'});
249			}
250			}
251
252			sub trimMessageStoreByTimestamp {
253			my $self=shift;
254			my $ts=shift;
255
256			while(scalar(@{$self->{'messages'}})>0 && $self->{'messages'}->[0]->timestamp()<$ts)
257			{
258			my $msg=shift(@{$self->{'messages'}});
259			}
260
261			$self->checkExpiration();
262			}
263
264			sub clearBuffer {
265			my $self=shift;
266
267			$self->{'messages'}=[];
268
269			$self->checkExpiration();
270			}
271
272			sub checkExpiration {
273			my $self=shift;
274
275			if($self->messageCount()==0 && $self->subscriberCount()==0)
276			{
277			my $name=$self->name();
278			&::syslog('debug',"Channel expired: $name");
279			$self->deleteChannel($name);
280			}
281			}
282
283			sub indexForMessageID {
284			my $self=shift;
285			my $id=shift;
286
287			# the messages is always sorted by ID, so we can
288			# use a binary search to find the message.
289			# return undef if there are no messages or the
290			# ID is that of the last message.
291			# Otherwise return the ID of the found message
292			# of if no message with that ID exists the one
293			# with the next higher ID
294			#
295			return undef unless(defined($id));
296
297	knops.gerd	46	my $numMessages=scalar(@{$self->{'messages'}});
298	knops.gerd	11
299			return undef unless($numMessages);
300			return -1 unless($id ne '');
301
302			# Note: negative $id means go back that many messages
303			return $numMessages+$id if($id<0);
304
305			my $low=0;
306			my $high=$numMessages-1;
307			my $mid;
308			my $cond;
309			while($low<=$high)
310			{
311			$mid=($low+$high)>>1;
312			$cond=$id <=> $self->{'messages'}->[$mid]->id();
313			if($cond<0)
314			{
315			$high=$mid-1;
316			}
317			elsif($cond>0)
318			{
319			$low=$mid+1;
320			}
321			else
322			{
323			return $mid;
324			}
325			}
326
327			return undef if($low>=$numMessages);
328
329			return $low;
330			}
331
332	knops.gerd	46	sub lastMsgID {
333			my $self=shift;
334
335			my $numMessages=scalar(@{$self->{'messages'}});
336
337			return 'undefined' unless($numMessages>0);
338
339			@{$self->{'messages'}}[-1]->id();
340			}
341
342	knops.gerd	45	sub descriptionWithTemplate {
343			my $self=shift;
344			my $template=shift;
345
346			$template=~s/~([a-zA-Z0-9_]*)~/
347			if(!defined($1) \|\| $1 eq '')
348			{
349			'~';
350			}
351			elsif($1 eq 'messageCount')
352			{
353			$self->messageCount();
354			}
355			elsif($1 eq 'subscriberCount')
356			{
357			$self->subscriberCount();
358			}
359	knops.gerd	46	elsif($1 eq 'lastMsgID')
360			{
361			$self->lastMsgID();
362			}
363
364	knops.gerd	45	elsif(exists($self->{$1}))
365			{
366			$self->{$1};
367			}
368			else
369			{
370			'';
371			}
372			/gex;
373
374			$template;
375			}
376
377	knops.gerd	11	1;
378	andrew.betts	3	############################################################################EOF