syncmail/vc.pm

package vc;

use Convert::Scalar 'weaken';

use Coro;
use Coro::Event;
use Coro::Channel;

BEGIN { *slog = \&::slog }

use constant MAXMSG => 1024;
use constant MAXQ   => 10;

use constant PROTVERSION => 1;

my @send;
my $send_full  = new Coro::Signal;
my $send_empty = new Coro::Signal;

my @port;
my $port;

sub dumpstr {
   local $_ = $_[0];
   s/([^\x20-\x7f\xa0-\xff])/sprintf "\\x{%02x}", ord $1/ge;
   $_ = "\"$_\"";
   (substr $_, 60) = "\"..." if length($_) > 60;
   $_;
}

# catch (accept) an existing vc
sub catch {
   my $class = shift;
   my $self = bless {
      rcv => (new Coro::Channel 1e9),
      @_,
   }, $class;

   weaken ($port[$self->{port}] = $self);
   $self;
}

# create (connect) a new vc
sub create {
   my $class = shift;
   my $self = $class->catch(port => ($port += 2), @_);

   $self;
}

sub DESTROY {
   &close;
}

sub close {
   my $self = shift;

   if ($self->{port}) {
      slog 0, "closing port $self->{port}\n";#d#
      push @{$send[0]}, pack "nn", $self->{port}, 65535;
      $send_full->send;
      delete $self->{port};
   }
}

sub pri {
   my $self = shift;
   $self->{pri} = $_[0];
}

sub _snd {
   my $self = shift;

   slog 8, ">>> :$self->{port} ".dumpstr($_[0])."\n"; #d#
   push @{$send[$self->{pri}]},
      pack "nna*", $self->{port}, length $_[0], $_[0];

}

sub _rcv {
   $_[0]{port} ? $_[0]{rcv}->get : undef;
}

sub snd {
   my $self = shift;
   my ($length, $ofs);

   $send_empty->wait while @send > MAXQ;
   for (@_) {
      if (length && MAXMSG >= length) {
         $self->_snd($_);
      } else {
         $self->_snd("");
         for (my $ofs = 0; $ofs < length; $ofs += MAXMSG) {
            $send_empty->wait while @send > MAXQ;
            $self->_snd(substr $_, $ofs, MAXMSG);
         }
         $self->_snd("");
      }
   }
   $send_full->send;
}

sub rcv {
   my $self = shift;
   my $data = $self->_rcv;

   unless (length $data) {
      my $blk;
      $data .= $blk while length ($blk = $self->_rcv);
   }

   $data;
}

sub feed {
   $_[0]{rcv}->put($_[1]);
}

sub snd_quit {
   push @{$send[0]}, undef; $send_full->send;
}

sub multiplex {
   my ($fh, $slave) = @_;

   $port = $slave ? 1 : 0;

   $fh->timeout($::TIMEOUT);

   # periodically send nop as keepalive signal to avoid the
   # rsync-on-slow-disk-timeout problem.
   my $nopper = Event->timer(parked => 1, cb => sub {
      push @{$send[0]}, pack "nn", 0, 1; $send_full->send;
   });

   my $ident = "\@SYNCMAIL VERSION $VERSION PROTOCOL ".PROTVERSION."\n";

   # the feeder
   async {
      my $id = "a";
      $fh->print(pack "na*", length $ident, $ident);
      command:
      while() {
         for (@send) {
            if (@$_) {
               my $vc = shift @$_;
               if (defined $vc) {
                  $fh->print($vc);
               } else {
                  last command;
               }
               $nopper->at(time+$::IDLE); $nopper->start;
               next command;
            }
         }
         $send_empty->send;
         $send_full->wait;
      }
      $fh->print(pack "nn", 0, 0);
   };

   async {
      eval {
         my ($port, $len, $data);

         $fh->read($len, 2) == 2
            or die "unexpected eof: $!";
         $fh->read($data, unpack "n", $len)
            or die "unexpected eof: $!";

         $data eq $ident
            or die "garbled input or version mismatch: $_";

         while ($fh->read($port, 4) == 4) {
            my ($port, $len) = unpack "nn", $port;

            if ($port) {
               if ($len > 65000) {
                  slog 8, "||| :$port closing\n";#d#
                  if ($port[$port]) {
                     delete $port[$port]{port};
                     $port[$port]->feed(undef);
                     undef $port[$port];
                  }
               } else {
                  $fh->sysread($data, $len) == $len
                     or die "unexpected read error: $!";

                  slog 8, "<<< :$port ".dumpstr($data)."\n"; #d#

                  unless ($port[$port]) {
                     async \&::serve, catch vc port => $port;
                  }

                  $port[$port]->feed($data);
               }
            } else {
               slog 8, "<<< :$port <$len>\n";

               if ($len == 0) {
                  snd_quit;
                  last;
               } elsif ($len == 1) {
                  # nop
               } else {
                  die "illegal control code received";
               }
            }
         }
      };

      slog 0, "ERROR: $@" if $@;
      slog 9, "unlooping\n";#d#
      unloop;
   };

   loop;
}

1;

Revision:	1.4
Committed:	Mon Oct 29 00:37:41 2001 UTC (22 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.3:	+7 -8 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package vc;
2
3			use Convert::Scalar 'weaken';
4
5			use Coro;
6			use Coro::Event;
7			use Coro::Channel;
8
9			BEGIN { *slog = \&::slog }
10
11			use constant MAXMSG => 1024;
12			use constant MAXQ => 10;
13
14	root	1.3	use constant PROTVERSION => 1;
15
16	root	1.1	my @send;
17			my $send_full = new Coro::Signal;
18			my $send_empty = new Coro::Signal;
19
20			my @port;
21			my $port;
22
23			sub dumpstr {
24	root	1.3	local $_ = $_[0];
25	root	1.1	s/([^\x20-\x7f\xa0-\xff])/sprintf "\\x{%02x}", ord $1/ge;
26			$_ = "\"$_\"";
27			(substr $_, 60) = "\"..." if length($_) > 60;
28			$_;
29			}
30
31	root	1.3	# catch (accept) an existing vc
32			sub catch {
33	root	1.1	my $class = shift;
34			my $self = bless {
35	root	1.2	rcv => (new Coro::Channel 1e9),
36	root	1.1	@_,
37			}, $class;
38
39			weaken ($port[$self->{port}] = $self);
40			$self;
41			}
42
43	root	1.3	# create (connect) a new vc
44			sub create {
45	root	1.1	my $class = shift;
46	root	1.3	my $self = $class->catch(port => ($port += 2), @_);
47	root	1.1
48			$self;
49			}
50
51			sub DESTROY {
52			&close;
53			}
54
55			sub close {
56			my $self = shift;
57
58			if ($self->{port}) {
59	root	1.4	slog 0, "closing port $self->{port}\n";#d#
60	root	1.1	push @{$send[0]}, pack "nn", $self->{port}, 65535;
61	root	1.4	$send_full->send;
62	root	1.1	delete $self->{port};
63			}
64			}
65
66			sub pri {
67			my $self = shift;
68			$self->{pri} = $_[0];
69			}
70
71	root	1.3	sub _snd {
72			my $self = shift;
73
74			slog 8, ">>> :$self->{port} ".dumpstr($_[0])."\n"; #d#
75			push @{$send[$self->{pri}]},
76			pack "nna*", $self->{port}, length $_[0], $_[0];
77
78			}
79
80			sub _rcv {
81			$_[0]{port} ? $_[0]{rcv}->get : undef;
82			}
83
84	root	1.1	sub snd {
85			my $self = shift;
86	root	1.3	my ($length, $ofs);
87	root	1.1
88			$send_empty->wait while @send > MAXQ;
89			for (@_) {
90	root	1.3	if (length && MAXMSG >= length) {
91			$self->_snd($_);
92			} else {
93			$self->_snd("");
94			for (my $ofs = 0; $ofs < length; $ofs += MAXMSG) {
95			$send_empty->wait while @send > MAXQ;
96			$self->_snd(substr $_, $ofs, MAXMSG);
97			}
98			$self->_snd("");
99			}
100	root	1.1	}
101			$send_full->send;
102			}
103
104			sub rcv {
105	root	1.3	my $self = shift;
106			my $data = $self->_rcv;
107
108			unless (length $data) {
109			my $blk;
110			$data .= $blk while length ($blk = $self->_rcv);
111			}
112
113			$data;
114	root	1.1	}
115
116			sub feed {
117			$_[0]{rcv}->put($_[1]);
118			}
119
120			sub snd_quit {
121			push @{$send[0]}, undef; $send_full->send;
122			}
123
124			sub multiplex {
125			my ($fh, $slave) = @_;
126
127			$port = $slave ? 1 : 0;
128
129			$fh->timeout($::TIMEOUT);
130
131			# periodically send nop as keepalive signal to avoid the
132			# rsync-on-slow-disk-timeout problem.
133			my $nopper = Event->timer(parked => 1, cb => sub {
134			push @{$send[0]}, pack "nn", 0, 1; $send_full->send;
135			});
136
137			my $ident = "\@SYNCMAIL VERSION $VERSION PROTOCOL ".PROTVERSION."\n";
138
139			# the feeder
140			async {
141			my $id = "a";
142			$fh->print(pack "na*", length $ident, $ident);
143			command:
144			while() {
145			for (@send) {
146			if (@$_) {
147			my $vc = shift @$_;
148			if (defined $vc) {
149			$fh->print($vc);
150			} else {
151			last command;
152			}
153			$nopper->at(time+$::IDLE); $nopper->start;
154			next command;
155			}
156			}
157			$send_empty->send;
158			$send_full->wait;
159			}
160			$fh->print(pack "nn", 0, 0);
161			};
162
163			async {
164			eval {
165			my ($port, $len, $data);
166
167			$fh->read($len, 2) == 2
168			or die "unexpected eof: $!";
169			$fh->read($data, unpack "n", $len)
170			or die "unexpected eof: $!";
171
172			$data eq $ident
173			or die "garbled input or version mismatch: $_";
174
175			while ($fh->read($port, 4) == 4) {
176			my ($port, $len) = unpack "nn", $port;
177
178			if ($port) {
179			if ($len > 65000) {
180			slog 8, "\|\|\| :$port closing\n";#d#
181			if ($port[$port]) {
182			delete $port[$port]{port};
183			$port[$port]->feed(undef);
184			undef $port[$port];
185			}
186			} else {
187			$fh->sysread($data, $len) == $len
188			or die "unexpected read error: $!";
189
190			slog 8, "<<< :$port ".dumpstr($data)."\n"; #d#
191
192	root	1.4	unless ($port[$port]) {
193			async \&::serve, catch vc port => $port;
194			}
195
196			$port[$port]->feed($data);
197	root	1.1	}
198			} else {
199			slog 8, "<<< :$port <$len>\n";
200
201			if ($len == 0) {
202			snd_quit;
203			last;
204			} elsif ($len == 1) {
205			# nop
206			} else {
207			die "illegal control code received";
208			}
209			}
210			}
211			};
212
213			slog 0, "ERROR: $@" if $@;
214			slog 9, "unlooping\n";#d#
215			unloop;
216			};
217
218			loop;
219			}
220
221			1;
222