1 |
=head1 NAME |
2 |
|
3 |
AnyEvent::MP::Global - some network-global services |
4 |
|
5 |
=head1 SYNOPSIS |
6 |
|
7 |
use AnyEvent::MP::Global; |
8 |
|
9 |
=head1 DESCRIPTION |
10 |
|
11 |
This module maintains a fully-meshed network, if possible, and tries to |
12 |
ensure that we are connected to at least one other node. |
13 |
|
14 |
It also manages named port groups - ports can register themselves in any |
15 |
number of groups that will be available network-wide, which is great for |
16 |
discovering services. |
17 |
|
18 |
Running it on one node will automatically run it on all nodes, although, |
19 |
at the moment, the global service is started by default anyways. |
20 |
|
21 |
=head1 GLOBALS AND FUNCTIONS |
22 |
|
23 |
=over 4 |
24 |
|
25 |
=cut |
26 |
|
27 |
package AnyEvent::MP::Global; |
28 |
|
29 |
use common::sense; |
30 |
use Carp (); |
31 |
|
32 |
use AnyEvent (); |
33 |
use AnyEvent::Util (); |
34 |
|
35 |
use AnyEvent::MP; |
36 |
use AnyEvent::MP::Kernel; |
37 |
use AnyEvent::MP::Transport (); |
38 |
|
39 |
use base "Exporter"; |
40 |
|
41 |
our @EXPORT = qw( |
42 |
grp_reg |
43 |
grp_get |
44 |
grp_mon |
45 |
); |
46 |
|
47 |
our $VERSION = $AnyEvent::MP::VERSION; |
48 |
|
49 |
our %addr; # port ID => [address...] mapping |
50 |
|
51 |
our %port; # our rendezvous port on the other side |
52 |
our %lreg; # local registry, name => [pid...] |
53 |
our %lmon; # local registry monitoring name,pid => mon |
54 |
our %greg; # global regstry, name => pid => undef |
55 |
our %gmon; # group monitoring, group => [$cb...] |
56 |
|
57 |
our $nodecnt; |
58 |
|
59 |
$AnyEvent::MP::Kernel::WARN->(7, "starting global service."); |
60 |
|
61 |
############################################################################# |
62 |
# seednodes |
63 |
|
64 |
our @SEEDS; |
65 |
our %SEEDS; # just to check whether a seed is a seed |
66 |
our %SEED_CONNECT; |
67 |
our $SEED_WATCHER; |
68 |
|
69 |
push @AnyEvent::MP::Transport::HOOK_CONNECT, sub { |
70 |
my $peer = $_[0]{local_greeting}{peeraddr}; |
71 |
return unless exists $SEEDS{$peer}; |
72 |
$SEED_CONNECT{$peer} = 2; |
73 |
}; |
74 |
|
75 |
push @AnyEvent::MP::Transport::HOOK_CONNECTED, sub { |
76 |
my $peer = $_[0]{local_greeting}{peeraddr}; |
77 |
return unless exists $SEEDS{$peer}; |
78 |
$SEEDS{$peer} = $_[0]{remote_node}; |
79 |
}; |
80 |
|
81 |
push @AnyEvent::MP::Transport::HOOK_DESTROY, sub { |
82 |
delete $SEED_CONNECT{$_[0]{local_greeting}{peeraddr}}; |
83 |
}; |
84 |
|
85 |
sub seed_connect { |
86 |
my ($seed) = @_; |
87 |
|
88 |
my ($host, $port) = AnyEvent::Socket::parse_hostport $seed |
89 |
or Carp::croak "$seed: unparsable seed address"; |
90 |
|
91 |
return if $SEED_CONNECT{$seed}; |
92 |
|
93 |
$AnyEvent::MP::Kernel::WARN->(9, "trying connect to seed node $seed."); |
94 |
|
95 |
# ughhh |
96 |
$SEED_CONNECT{$seed} ||= AnyEvent::MP::Transport::mp_connect $host, $port, |
97 |
seed => $seed, |
98 |
sub { |
99 |
$SEED_CONNECT{$seed} = 1; |
100 |
}, |
101 |
; |
102 |
} |
103 |
|
104 |
sub more_seeding { |
105 |
my $int = List::Util::max 1, |
106 |
$AnyEvent::MP::Kernel::CONFIG->{connect_interval} |
107 |
* ($nodecnt ? keys %AnyEvent::MP::Kernel::NODE : 1) |
108 |
- rand; |
109 |
|
110 |
$SEED_WATCHER = AE::timer $int, 0, \&more_seeding; |
111 |
|
112 |
@SEEDS = keys %SEEDS unless @SEEDS; |
113 |
return unless @SEEDS; |
114 |
|
115 |
seed_connect splice @SEEDS, rand @SEEDS, 1; |
116 |
} |
117 |
|
118 |
sub avoid_seed($) { |
119 |
delete $SEEDS{$_[0]}; |
120 |
} |
121 |
|
122 |
sub set_seeds(@) { |
123 |
@SEEDS{@_} = (); |
124 |
|
125 |
$SEED_WATCHER ||= AE::timer 5, $AnyEvent::MP::Kernel::MONITOR_TIMEOUT, \&more_seeding; |
126 |
|
127 |
for (1 .. keys %SEEDS) { |
128 |
after 0.100 * rand, \&more_seeding; |
129 |
} |
130 |
} |
131 |
|
132 |
# returns all (up) seed nodes, or all nodes if no seednodes are up/known |
133 |
sub _route_nodes { |
134 |
my @seeds = grep node_is_up $_, values %SEEDS; |
135 |
@seeds = up_nodes unless @seeds; |
136 |
@seeds |
137 |
} |
138 |
|
139 |
############################################################################# |
140 |
|
141 |
sub _change { |
142 |
my ($group, $add, $del) = @_; |
143 |
|
144 |
my $kv = $greg{$group} ||= {}; |
145 |
|
146 |
delete @$kv{@$del}; |
147 |
@$kv{@$add} = (); |
148 |
|
149 |
my $ports = [keys %$kv]; |
150 |
$_->($ports, $add, $del) for @{ $gmon{$group} }; |
151 |
} |
152 |
|
153 |
sub unreg_groups($) { |
154 |
my ($node) = @_; |
155 |
|
156 |
my $qr = qr/^\Q$node\E(?:#|$)/; |
157 |
my @del; |
158 |
|
159 |
while (my ($group, $ports) = each %greg) { |
160 |
@del = grep /$qr/, keys %$ports; |
161 |
_change $group, [], \@del |
162 |
if @del; |
163 |
} |
164 |
} |
165 |
|
166 |
sub set_groups($$) { |
167 |
my ($node, $lreg) = @_; |
168 |
|
169 |
while (my ($k, $v) = each %$lreg) { |
170 |
_change $k, $v, []; |
171 |
} |
172 |
} |
173 |
|
174 |
=item $guard = grp_reg $group, $port |
175 |
|
176 |
Register the given (local!) port in the named global group C<$group>. |
177 |
|
178 |
The port will be unregistered automatically when the port is destroyed. |
179 |
|
180 |
When not called in void context, then a guard object will be returned that |
181 |
will also cause the name to be unregistered when destroyed. |
182 |
|
183 |
=cut |
184 |
|
185 |
# unregister local port |
186 |
sub unregister { |
187 |
my ($port, $group) = @_; |
188 |
|
189 |
delete $lmon{"$group\x00$port"}; |
190 |
@{ $lreg{$group} } = grep $_ ne $port, @{ $lreg{$group} }; |
191 |
|
192 |
_change $group, [], [$port]; |
193 |
|
194 |
snd $_, reg0 => $group, $port |
195 |
for values %port; |
196 |
} |
197 |
|
198 |
# register local port |
199 |
sub grp_reg($$) { |
200 |
my ($group, $port) = @_; |
201 |
|
202 |
port_is_local $port |
203 |
or Carp::croak "AnyEvent::MP::Global::grp_reg can only be called for local ports, caught"; |
204 |
|
205 |
grep $_ eq $port, @{ $lreg{$group} } |
206 |
and Carp::croak "'$group': group already registered, cannot register a second time"; |
207 |
|
208 |
$lmon{"$group\x00$port"} = mon $port, sub { unregister $port, $group }; |
209 |
push @{ $lreg{$group} }, $port; |
210 |
|
211 |
snd $_, reg1 => $group, $port |
212 |
for values %port; |
213 |
|
214 |
_change $group, [$port], []; |
215 |
|
216 |
wantarray && AnyEvent::Util::guard { unregister $port, $group } |
217 |
} |
218 |
|
219 |
=item $ports = grp_get $group |
220 |
|
221 |
Returns all the ports currently registered to the given group (as |
222 |
read-only(!) array reference). When the group has no registered members, |
223 |
return C<undef>. |
224 |
|
225 |
=cut |
226 |
|
227 |
sub grp_get($) { |
228 |
my @ports = keys %{ $greg{$_[0]} }; |
229 |
@ports ? \@ports : undef |
230 |
} |
231 |
|
232 |
=item $guard = grp_mon $group, $callback->($ports, $add, $del) |
233 |
|
234 |
Installs a monitor on the given group. Each time there is a change it |
235 |
will be called with the current group members as an arrayref as the |
236 |
first argument. The second argument only contains ports added, the third |
237 |
argument only ports removed. |
238 |
|
239 |
Unlike C<grp_get>, all three arguments will always be array-refs, even if |
240 |
the array is empty. None of the arrays must be modified in any way. |
241 |
|
242 |
The first invocation will be with the first two arguments set to the |
243 |
current members, as if all of them were just added, but only when the |
244 |
group is atcually non-empty. |
245 |
|
246 |
Optionally returns a guard object that uninstalls the watcher when it is |
247 |
destroyed. |
248 |
|
249 |
=cut |
250 |
|
251 |
sub grp_mon($$) { |
252 |
my ($grp, $cb) = @_; |
253 |
|
254 |
AnyEvent::MP::Kernel::delay sub { |
255 |
return unless $cb; |
256 |
|
257 |
push @{ $gmon{$grp} }, $cb; |
258 |
$cb->(((grp_get $grp) || return) x 2, []); |
259 |
}; |
260 |
|
261 |
defined wantarray && AnyEvent::Util::::guard { |
262 |
my @mon = grep $_ != $cb, @{ delete $gmon{$grp} }; |
263 |
$gmon{$grp} = \@mon if @mon; |
264 |
undef $cb; |
265 |
} |
266 |
} |
267 |
|
268 |
sub start_node { |
269 |
my ($node) = @_; |
270 |
|
271 |
return if exists $port{$node}; |
272 |
return if $node eq $NODE; # do not connect to ourselves |
273 |
|
274 |
# establish connection |
275 |
my $port = $port{$node} = spawn $node, "AnyEvent::MP::Global::connect", 0, $NODE; |
276 |
|
277 |
mon $port, sub { |
278 |
unreg_groups $node; |
279 |
delete $port{$node}; |
280 |
}; |
281 |
|
282 |
snd $port, addr => $AnyEvent::MP::Kernel::LISTENER; |
283 |
snd $port, nodes => \%addr if %addr; |
284 |
snd $port, set => \%lreg if %lreg; |
285 |
} |
286 |
|
287 |
# other nodes connect via this |
288 |
sub connect { |
289 |
my ($version, $node) = @_; |
290 |
|
291 |
# monitor them, silently die |
292 |
mon $node, psub { kil $SELF }; |
293 |
|
294 |
rcv $SELF, |
295 |
addr => sub { |
296 |
my $addresses = shift; |
297 |
$AnyEvent::MP::Kernel::WARN->(9, "$node told us its addresses (@$addresses)."); |
298 |
$addr{$node} = $addresses; |
299 |
|
300 |
# to help listener-less nodes, we broadcast new addresses to them unconditionally |
301 |
#TODO: should be done by a node finding out about a listener-less one |
302 |
if (@$addresses) { |
303 |
for my $other (values %AnyEvent::MP::Kernel::NODE) { |
304 |
if ($other->{transport}) { |
305 |
if ($addr{$other->{id}} && !@{ $addr{$other->{id}} }) { |
306 |
$AnyEvent::MP::Kernel::WARN->(9, "helping $other->{id} to find $node."); |
307 |
snd $port{$other->{id}}, nodes => { $node => $addresses }; |
308 |
} |
309 |
} |
310 |
} |
311 |
} |
312 |
}, |
313 |
nodes => sub { |
314 |
my ($kv) = @_; |
315 |
|
316 |
use JSON::XS;#d# |
317 |
my $kv_txt = JSON::XS->new->encode ($kv);#d# |
318 |
$AnyEvent::MP::Kernel::WARN->(9, "$node told us it knows about $kv_txt.");#d# |
319 |
|
320 |
while (my ($id, $addresses) = each %$kv) { |
321 |
my $node = AnyEvent::MP::Kernel::add_node $id; |
322 |
$node->connect (@$addresses); |
323 |
start_node $id; |
324 |
} |
325 |
}, |
326 |
find => sub { |
327 |
my ($othernode) = @_; |
328 |
|
329 |
$AnyEvent::MP::Kernel::WARN->(9, "$node asked us to find $othernode."); |
330 |
snd $port{$node}, nodes => { $othernode => $addr{$othernode} } |
331 |
if $addr{$othernode}; |
332 |
}, |
333 |
set => sub { |
334 |
set_groups $node, shift; |
335 |
}, |
336 |
reg0 => sub { |
337 |
_change $_[0], [], [$_[1]]; |
338 |
}, |
339 |
reg1 => sub { |
340 |
_change $_[0], [$_[1]], []; |
341 |
}, |
342 |
; |
343 |
} |
344 |
|
345 |
sub mon_node { |
346 |
my ($node, $is_up) = @_; |
347 |
|
348 |
if ($is_up) { |
349 |
++$nodecnt; |
350 |
start_node $node; |
351 |
} else { |
352 |
--$nodecnt; |
353 |
more_seeding unless $nodecnt; |
354 |
unreg_groups $node; |
355 |
|
356 |
# forget about the node |
357 |
delete $addr{$node}; |
358 |
# ask other nodes if they know the node |
359 |
snd $_, find => $node |
360 |
for values %port; |
361 |
} |
362 |
#warn "node<$node,$is_up>\n";#d# |
363 |
} |
364 |
|
365 |
mon_node $_, 1 |
366 |
for up_nodes; |
367 |
|
368 |
mon_nodes \&mon_node; |
369 |
|
370 |
=back |
371 |
|
372 |
=head1 SEE ALSO |
373 |
|
374 |
L<AnyEvent::MP>. |
375 |
|
376 |
=head1 AUTHOR |
377 |
|
378 |
Marc Lehmann <schmorp@schmorp.de> |
379 |
http://home.schmorp.de/ |
380 |
|
381 |
=cut |
382 |
|
383 |
1 |
384 |
|