AnyEvent-MP/MP/Global.pm

=head1 NAME

AnyEvent::MP::Global - network backbone services

=head1 SYNOPSIS

   use AnyEvent::MP::Global;

=head1 DESCRIPTION

This module is usually run (or started on) seed nodes and provides a
variety of services to connected nodes, such as the distributed database.

The global nodes form a fully-meshed network, that is, all global nodes
currently maintain connections to all other global nodes.

Loading this module (e.g. as a service) transforms the local node into a
global node. There are no user-servicable parts inside.

For a limited time, this module also exports some AEMP 1.x compatibility
functions (C<grp_reg>, C<grp_get> and C<grp_mon>).

=cut

package AnyEvent::MP::Global;

use common::sense;
use Carp ();

use AnyEvent ();

use AnyEvent::MP;
use AnyEvent::MP::Kernel;

AE::log 7 => "starting global service.";

#############################################################################
# node protocol parts for global nodes

package AnyEvent::MP::Kernel;

# TODO: this is ugly (classical use vars vs. our),
# maybe this should go into MP::Kernel

our %NODE;
our $NODE;

our $GLOBAL;
our $MASTER;
our $MASTER_TIMER;

our %GLOBAL_SLAVE;

our %GLOBAL_DB; # global db
our %LOCAL_DBS; # local databases of other nodes (global and slave)
our %LOCAL_DB;  # this node database

our $SRCNODE; # the origin node id
our %NODE_REQ;

# only in global code
our %GLOBAL_MON; # monitors {family}

# broadcasts a message to all other global nodes
sub g_broadcast {
   snd $_, @_
      for grep $_ ne $NODE && node_is_up $_, keys %{ $GLOBAL_DB{"'g"} }
}

# add/replace/del inside a family in the database
# @$del must not contain any key in %$set
sub g_upd {
   my ($node, $family, $set, $del) = @_;

   my $ldb = $LOCAL_DBS{$node}{$family} ||= {};
   my $gdb = $GLOBAL_DB       {$family} ||= {};

   # add/replace keys
   while (my ($k, $v) = each %$set) {
      $ldb->{$k} =
      $gdb->{$k} = $v;
   }

   my @del; # actual deletes

   # take care of deletes
   keydel:
   for my $k (@$del) {
      next unless exists $ldb->{$k};

      delete $ldb->{$k};
      delete $gdb->{$k};

      # check if some other node still has the key, then we don't delete, but change
      for (values %LOCAL_DBS) {
         if (exists $_->{$family}{$k}) {
            $set->{$k} = $gdb->{$k} = $_->{$family}{$k};

            next keydel;
         }
      }

      push @del, $k;
   }

   # family could be empty now
   delete $GLOBAL_DB{$family} unless %$gdb;
   delete $LOCAL_DBS{$node}{$family} unless %$ldb;

   return unless %$set || @del;

   g_broadcast g_upd => $family, $set, \@del
      if exists $GLOBAL_SLAVE{$node};

   # tell subscribers we have changed the family
   snd $_ => g_chg2 => $family, $set, \@del
      for keys %{ $GLOBAL_MON{$family} };
}

# set the whole (node-local) database - previous value must be empty
sub g_set($$) {
   my ($node, $db) = @_;

   while (my ($f, $k) = each %$db) {
      g_upd $node, $f, $k;
   }
}

# delete all keys from a database
sub g_clr($) {
   my ($node) = @_;

   my $db = $LOCAL_DBS{$node};

   while (my ($f, $k) = each %$db) {
      g_upd $node, $f, undef, [keys %$k];
   }

   delete $LOCAL_DBS{$node};
}

# gather node databases from slaves

# other node wants to make us the master
$NODE_REQ{g_slave} = sub {
   my ($db) = @_
      or return; # empty g_slave is used to start global service

   my $node = $SRCNODE;
   undef $GLOBAL_SLAVE{$node};
   g_set $node, $db;
};

# other node (global and slave) sends us their database
$NODE_REQ{g_set} = sub {
   &g_set ($SRCNODE, @_);
};

# other node (global and slave) sends us a family update
$NODE_REQ{g_upd} = sub {
   &g_upd ($SRCNODE, @_);
};

# slave node wants to know the listeners of a node
$NODE_REQ{g_find} = sub {
   my ($node) = @_;

   snd $SRCNODE, g_found => $node, $GLOBAL_DB{"'l"}{$node};
};

$NODE_REQ{g_db_family} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, $GLOBAL_DB{$family} || {};
};

$NODE_REQ{g_db_keys} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, [keys %{ $GLOBAL_DB{$family} } ];
};

$NODE_REQ{g_db_values} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, [values %{ $GLOBAL_DB{$family} } ];
};

# monitoring

sub g_disconnect($) {
   my ($node) = @_;

   db_del "'g" => $node;
   g_clr $node;

   if (my $mon = delete $GLOBAL_SLAVE{$node}) {
      while (my ($f, $fv) = each %$mon) {
         delete $GLOBAL_MON{$f}{$_}
            for keys %$fv;

         delete $GLOBAL_MON{$f}
            unless %{ $GLOBAL_MON{$f} };
      }
   }
}

# g_mon0 family - stop monitoring
$NODE_REQ{g_mon0} = sub {
   delete $GLOBAL_MON{$_[0]}{$SRCNODE};
   delete $GLOBAL_MON{$_[0]} unless %{ $GLOBAL_MON{$_[0]} };

   delete $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
};

# g_mon1 family key - start monitoring
$NODE_REQ{g_mon1} = sub {
   undef $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
   undef $GLOBAL_MON{$_[0]}{$SRCNODE};

   snd $SRCNODE, g_chg1 => $_[0], $GLOBAL_DB{$_[0]};
};

#############################################################################
# switch to global mode

# delete data from other nodes on node-down
mon_nodes sub {
   g_disconnect $_[0] unless $_[1];
};

# tell everybody who connects that we are a global node
push @AnyEvent::MP::Transport::HOOK_GREET, sub {
   $_[0]{local_greeting}{global} = 1;
};

# connect from a global node
sub g_global_connect {
   my ($node) = @_;

   # each node puts the set of connected global nodes into
   # 'g - this causes a big duplication and mergefest, but
   # is the easiest way to ensure global nodes have a list
   # of all other global nodes.

   db_set "'g" => $node;

   # global nodes send all local databases of their slaves, merged,
   # as their local database to other global nodes
   my %db;

   while (my ($k, $v) = each %LOCAL_DBS) {
      next unless exists $GLOBAL_SLAVE{$k};

      while (my ($f, $fv) = each %$_) {
         while (my ($k, $kv) = each %$fv) {
            $db{$f}{$k} = $kv;
         }
      }
   }

   snd $node => g_set => \%db;
}

# send our database to every global node that connects
push @AnyEvent::MP::Transport::HOOK_CONNECT, sub {
   return unless $_[0]{remote_greeting}{global};

   g_global_connect $_[0]{remote_node};
};

# tell other global nodes that we are global now
# TODO: there is probably a race when two conencted nodes beocme global at the same time
# very ugly.
for (values %NODE) {
   if ($_->{transport} && $_->{transport}{remote_greeting}{global}) {
      snd $_->{id} => "g_global";
      g_global_connect $_->{id};
   }
}

$NODE_REQ{g_global} = sub {
   g_disconnect $SRCNODE;

   my $node = $NODE{$SRCNODE};
   $node->{transport}{remote_greeting}{global} = 1;

   g_global_connect $SRCNODE;
};

# enable global mode
$GLOBAL = 1;

# global nodes are their own masters - this
# resends global requests and sets the local database.
master_set $NODE;

# from here on we should be able to act normally

# now add us to the set of global nodes
db_set "'g" => $NODE;

# maintain connections to all global nodes that we know of
db_mon "'g" => sub {
   keepalive_add $_ for @{ $_[1] };
   keepalive_del $_ for @{ $_[3] };
};

#############################################################################
# compatibility functions for aemp 1.0

package AnyEvent::MP::Global;

use base "Exporter";
our @EXPORT = qw(grp_reg grp_get grp_mon);

sub grp_reg($$) {
   &db_reg
}

sub grp_get($) {
   my @ports = keys %{ $AnyEvent::MP::Kernel::GLOBAL_DB{$_[0]} };

   @ports ? \@ports : undef
}

sub grp_mon($$) {
   my ($grp, $cb) = @_;

   db_mon $grp => sub {
      my ($ports, $add, $chg, $del) = @_;

      $cb->([keys %$ports], $add, $del);
   };
}

=head1 SEE ALSO

L<AnyEvent::MP>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.68
Committed:	Sat Mar 24 13:05:40 2012 UTC (12 years, 2 months ago) by root
Branch:	MAIN
Changes since 1.67:	+24 -15 lines
Log Message:	* empty log message *
#	Content
1	=head1 NAME
2
3	AnyEvent::MP::Global - network backbone services
4
5	=head1 SYNOPSIS
6
7	use AnyEvent::MP::Global;
8
9	=head1 DESCRIPTION
10
11	This module is usually run (or started on) seed nodes and provides a
12	variety of services to connected nodes, such as the distributed database.
13
14	The global nodes form a fully-meshed network, that is, all global nodes
15	currently maintain connections to all other global nodes.
16
17	Loading this module (e.g. as a service) transforms the local node into a
18	global node. There are no user-servicable parts inside.
19
20	For a limited time, this module also exports some AEMP 1.x compatibility
21	functions (C<grp_reg>, C<grp_get> and C<grp_mon>).
22
23	=cut
24
25	package AnyEvent::MP::Global;
26
27	use common::sense;
28	use Carp ();
29
30	use AnyEvent ();
31
32	use AnyEvent::MP;
33	use AnyEvent::MP::Kernel;
34
35	AE::log 7 => "starting global service.";
36
37	#############################################################################
38	# node protocol parts for global nodes
39
40	package AnyEvent::MP::Kernel;
41
42	# TODO: this is ugly (classical use vars vs. our),
43	# maybe this should go into MP::Kernel
44
45	our %NODE;
46	our $NODE;
47
48	our $GLOBAL;
49	our $MASTER;
50	our $MASTER_TIMER;
51
52	our %GLOBAL_SLAVE;
53
54	our %GLOBAL_DB; # global db
55	our %LOCAL_DBS; # local databases of other nodes (global and slave)
56	our %LOCAL_DB; # this node database
57
58	our $SRCNODE; # the origin node id
59	our %NODE_REQ;
60
61	# only in global code
62	our %GLOBAL_MON; # monitors {family}
63
64	# broadcasts a message to all other global nodes
65	sub g_broadcast {
66	snd $_, @_
67	for grep $_ ne $NODE && node_is_up $_, keys %{ $GLOBAL_DB{"'g"} }
68	}
69
70	# add/replace/del inside a family in the database
71	# @$del must not contain any key in %$set
72	sub g_upd {
73	my ($node, $family, $set, $del) = @_;
74
75	my $ldb = $LOCAL_DBS{$node}{$family} \|\|= {};
76	my $gdb = $GLOBAL_DB {$family} \|\|= {};
77
78	# add/replace keys
79	while (my ($k, $v) = each %$set) {
80	$ldb->{$k} =
81	$gdb->{$k} = $v;
82	}
83
84	my @del; # actual deletes
85
86	# take care of deletes
87	keydel:
88	for my $k (@$del) {
89	next unless exists $ldb->{$k};
90
91	delete $ldb->{$k};
92	delete $gdb->{$k};
93
94	# check if some other node still has the key, then we don't delete, but change
95	for (values %LOCAL_DBS) {
96	if (exists $_->{$family}{$k}) {
97	$set->{$k} = $gdb->{$k} = $_->{$family}{$k};
98
99	next keydel;
100	}
101	}
102
103	push @del, $k;
104	}
105
106	# family could be empty now
107	delete $GLOBAL_DB{$family} unless %$gdb;
108	delete $LOCAL_DBS{$node}{$family} unless %$ldb;
109
110	return unless %$set \|\| @del;
111
112	g_broadcast g_upd => $family, $set, \@del
113	if exists $GLOBAL_SLAVE{$node};
114
115	# tell subscribers we have changed the family
116	snd $_ => g_chg2 => $family, $set, \@del
117	for keys %{ $GLOBAL_MON{$family} };
118	}
119
120	# set the whole (node-local) database - previous value must be empty
121	sub g_set($$) {
122	my ($node, $db) = @_;
123
124	while (my ($f, $k) = each %$db) {
125	g_upd $node, $f, $k;
126	}
127	}
128
129	# delete all keys from a database
130	sub g_clr($) {
131	my ($node) = @_;
132
133	my $db = $LOCAL_DBS{$node};
134
135	while (my ($f, $k) = each %$db) {
136	g_upd $node, $f, undef, [keys %$k];
137	}
138
139	delete $LOCAL_DBS{$node};
140	}
141
142	# gather node databases from slaves
143
144	# other node wants to make us the master
145	$NODE_REQ{g_slave} = sub {
146	my ($db) = @_
147	or return; # empty g_slave is used to start global service
148
149	my $node = $SRCNODE;
150	undef $GLOBAL_SLAVE{$node};
151	g_set $node, $db;
152	};
153
154	# other node (global and slave) sends us their database
155	$NODE_REQ{g_set} = sub {
156	&g_set ($SRCNODE, @_);
157	};
158
159	# other node (global and slave) sends us a family update
160	$NODE_REQ{g_upd} = sub {
161	&g_upd ($SRCNODE, @_);
162	};
163
164	# slave node wants to know the listeners of a node
165	$NODE_REQ{g_find} = sub {
166	my ($node) = @_;
167
168	snd $SRCNODE, g_found => $node, $GLOBAL_DB{"'l"}{$node};
169	};
170
171	$NODE_REQ{g_db_family} = sub {
172	my ($family, $id) = @_;
173	snd $SRCNODE, g_reply => $id, $GLOBAL_DB{$family} \|\| {};
174	};
175
176	$NODE_REQ{g_db_keys} = sub {
177	my ($family, $id) = @_;
178	snd $SRCNODE, g_reply => $id, [keys %{ $GLOBAL_DB{$family} } ];
179	};
180
181	$NODE_REQ{g_db_values} = sub {
182	my ($family, $id) = @_;
183	snd $SRCNODE, g_reply => $id, [values %{ $GLOBAL_DB{$family} } ];
184	};
185
186	# monitoring
187
188	sub g_disconnect($) {
189	my ($node) = @_;
190
191	db_del "'g" => $node;
192	g_clr $node;
193
194	if (my $mon = delete $GLOBAL_SLAVE{$node}) {
195	while (my ($f, $fv) = each %$mon) {
196	delete $GLOBAL_MON{$f}{$_}
197	for keys %$fv;
198
199	delete $GLOBAL_MON{$f}
200	unless %{ $GLOBAL_MON{$f} };
201	}
202	}
203	}
204
205	# g_mon0 family - stop monitoring
206	$NODE_REQ{g_mon0} = sub {
207	delete $GLOBAL_MON{$_[0]}{$SRCNODE};
208	delete $GLOBAL_MON{$_[0]} unless %{ $GLOBAL_MON{$_[0]} };
209
210	delete $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
211	};
212
213	# g_mon1 family key - start monitoring
214	$NODE_REQ{g_mon1} = sub {
215	undef $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
216	undef $GLOBAL_MON{$_[0]}{$SRCNODE};
217
218	snd $SRCNODE, g_chg1 => $_[0], $GLOBAL_DB{$_[0]};
219	};
220
221	#############################################################################
222	# switch to global mode
223
224	# delete data from other nodes on node-down
225	mon_nodes sub {
226	g_disconnect $_[0] unless $_[1];
227	};
228
229	# tell everybody who connects that we are a global node
230	push @AnyEvent::MP::Transport::HOOK_GREET, sub {
231	$_[0]{local_greeting}{global} = 1;
232	};
233
234	# connect from a global node
235	sub g_global_connect {
236	my ($node) = @_;
237
238	# each node puts the set of connected global nodes into
239	# 'g - this causes a big duplication and mergefest, but
240	# is the easiest way to ensure global nodes have a list
241	# of all other global nodes.
242
243	db_set "'g" => $node;
244
245	# global nodes send all local databases of their slaves, merged,
246	# as their local database to other global nodes
247	my %db;
248
249	while (my ($k, $v) = each %LOCAL_DBS) {
250	next unless exists $GLOBAL_SLAVE{$k};
251
252	while (my ($f, $fv) = each %$_) {
253	while (my ($k, $kv) = each %$fv) {
254	$db{$f}{$k} = $kv;
255	}
256	}
257	}
258
259	snd $node => g_set => \%db;
260	}
261
262	# send our database to every global node that connects
263	push @AnyEvent::MP::Transport::HOOK_CONNECT, sub {
264	return unless $_[0]{remote_greeting}{global};
265
266	g_global_connect $_[0]{remote_node};
267	};
268
269	# tell other global nodes that we are global now
270	# TODO: there is probably a race when two conencted nodes beocme global at the same time
271	# very ugly.
272	for (values %NODE) {
273	if ($_->{transport} && $_->{transport}{remote_greeting}{global}) {
274	snd $_->{id} => "g_global";
275	g_global_connect $_->{id};
276	}
277	}
278
279	$NODE_REQ{g_global} = sub {
280	g_disconnect $SRCNODE;
281
282	my $node = $NODE{$SRCNODE};
283	$node->{transport}{remote_greeting}{global} = 1;
284
285	g_global_connect $SRCNODE;
286	};
287
288	# enable global mode
289	$GLOBAL = 1;
290
291	# global nodes are their own masters - this
292	# resends global requests and sets the local database.
293	master_set $NODE;
294
295	# from here on we should be able to act normally
296
297	# now add us to the set of global nodes
298	db_set "'g" => $NODE;
299
300	# maintain connections to all global nodes that we know of
301	db_mon "'g" => sub {
302	keepalive_add $_ for @{ $_[1] };
303	keepalive_del $_ for @{ $_[3] };
304	};
305
306	#############################################################################
307	# compatibility functions for aemp 1.0
308
309	package AnyEvent::MP::Global;
310
311	use base "Exporter";
312	our @EXPORT = qw(grp_reg grp_get grp_mon);
313
314	sub grp_reg($$) {
315	&db_reg
316	}
317
318	sub grp_get($) {
319	my @ports = keys %{ $AnyEvent::MP::Kernel::GLOBAL_DB{$_[0]} };
320
321	@ports ? \@ports : undef
322	}
323
324	sub grp_mon($$) {
325	my ($grp, $cb) = @_;
326
327	db_mon $grp => sub {
328	my ($ports, $add, $chg, $del) = @_;
329
330	$cb->([keys %$ports], $add, $del);
331	};
332	}
333
334	=head1 SEE ALSO
335
336	L<AnyEvent::MP>.
337
338	=head1 AUTHOR
339
340	Marc Lehmann <schmorp@schmorp.de>
341	http://home.schmorp.de/
342
343	=cut
344
345	1
346