src/lib/Bcd/Clients/ClientsListeners.pm

   1 package Bcd::Clients::ClientsListeners;
   2
   3 # This file is part of the breadcrumbs daemon (bcd).
   4 # Copyright (C) 2007 Pasqualino Ferrentino
   5
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful, but
  12 # WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 # 02110-1301, USA.
  20
  21 # Contact: lino.ferrentino@yahoo.it (in Italian, English or German).
  22
  23 #this file contains the set of the listeners in our program.
  24 #each listener is in its own thread.
  25
  26 #this file is a singleton.
  27
  28 use strict;
  29 use warnings;
  30 use threads;
  31 use threads::shared;
  32 use Class::Singleton;
  33
  34 use Bcd::Clients::Listener;
  35 use Data::Dumper;
  36
  37 use vars qw(@ISA);
  38 @ISA = qw(Class::Singleton);
  39 use constant EOL => "\015\012";
  40
  41 use constant{
  42     # Some constants to initialize the number of threads in this program...
  43     INITAL_LISTENERS => 1,
  44     MAX_LISTENERS => 5,
  45 };
  46
  47
  48
  49 sub _new_instance{
  50     my ($class, $script, $files_to_delete, $queue_of_files_to_delete) = @_;
  51
  52     my $self = {};
  53
  54     bless ($self, $class);
  55
  56     $self->{script} = $script;
  57     $self->{files_to_delete} = $files_to_delete;
  58     $self->{queue_of_files_to_delete} = $queue_of_files_to_delete;
  59
  60     $self->_create_the_listeners($script);
  61
  62
  63     return $self;
  64 }
  65
  66 sub _create_the_listeners{
  67
  68     my ($self, $script) = @_;
  69
  70     #if you want the script you have only one listener...
  71     my @listeners;
  72
  73     my $listeners_num;
  74
  75     if ($script == 1) {
  76         $listeners_num = 1;
  77     } else {
  78         $listeners_num = INITAL_LISTENERS;
  79     }
  80
  81     for ( my $i = 0 ; $i < $listeners_num ; ++$i){
  82         #ok, let's create them
  83
  84         my $listener = Bcd::Clients::Listener->new
  85             ($script, $self->{queue_of_files_to_delete});
  86         push (@listeners, $listener);
  87     }
  88
  89     $self->{"listeners"} = \@listeners;
  90 }
  91
  92 #this function is called whenever a new client wants to talk to the
  93 #daemon.  this function can blocks the incoming client because we have
  94 #not reasource available to serve it
  95 sub a_new_client_has_arrived{
  96
  97     my ($self, $client) = @_;
  98
  99     #ok, let's try to get a free listener for this client
 100
 101     foreach (@{$self->{listeners}}){
 102         if ($_->are_you_free()){
 103             #ok... this listener is free
 104             $_->serve_this_client($client, $self->{files_to_delete});
 105             return; #all ok, you can return
 106         }
 107     }
 108
 109
 110     #can I create another listener?
 111     if ( scalar(@{$self->{listeners}}) < MAX_LISTENERS){
 112         #I can add a listener
 113         my $listener = Bcd::Clients::Listener->new
 114             ($self->{script}, $self->{queue_of_files_to_delete});
 115         push (@{$self->{listeners}}, $listener);
 116
 117         #This listener is obviously free
 118         $listener->serve_this_client($client, $self->{files_to_delete});
 119         return;
 120
 121     } else {
 122         #I cannot create another listener...
 123         #pick one at random
 124         my $index = int(rand(scalar(@{$self->{listeners}})));
 125         $self->{listeners}->[$index]->serve_this_client($client, $self->{files_to_delete});
 126     }
 127
 128 }
 129
 130 1;