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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.204 by root, Mon Nov 15 03:29:17 2010 UTC vs.
Revision 1.233 by root, Thu Apr 5 06:14:10 2012 UTC

11 11
12 my $hdl; $hdl = new AnyEvent::Handle 12 my $hdl; $hdl = new AnyEvent::Handle
13 fh => \*STDIN, 13 fh => \*STDIN,
14 on_error => sub { 14 on_error => sub {
15 my ($hdl, $fatal, $msg) = @_; 15 my ($hdl, $fatal, $msg) = @_;
16 warn "got error $msg\n"; 16 AE::log error => $msg;
17 $hdl->destroy; 17 $hdl->destroy;
18 $cv->send; 18 $cv->send;
19 }; 19 };
20 20
21 # send some request line 21 # send some request line
22 $hdl->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
23 23
24 # read the response line 24 # read the response line
25 $hdl->push_read (line => sub { 25 $hdl->push_read (line => sub {
26 my ($hdl, $line) = @_; 26 my ($hdl, $line) = @_;
27 warn "got line <$line>\n"; 27 say "got line <$line>";
28 $cv->send; 28 $cv->send;
29 }); 29 });
30 30
31 $cv->recv; 31 $cv->recv;
32 32
114=over 4 114=over 4
115 115
116=item on_prepare => $cb->($handle) 116=item on_prepare => $cb->($handle)
117 117
118This (rarely used) callback is called before a new connection is 118This (rarely used) callback is called before a new connection is
119attempted, but after the file handle has been created. It could be used to 119attempted, but after the file handle has been created (you can access that
120file handle via C<< $handle->{fh} >>). It could be used to prepare the
120prepare the file handle with parameters required for the actual connect 121file handle with parameters required for the actual connect (as opposed to
121(as opposed to settings that can be changed when the connection is already 122settings that can be changed when the connection is already established).
122established).
123 123
124The return value of this callback should be the connect timeout value in 124The return value of this callback should be the connect timeout value in
125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the 125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
126default timeout is to be used). 126default timeout is to be used).
127 127
128=item on_connect => $cb->($handle, $host, $port, $retry->()) 128=item on_connect => $cb->($handle, $host, $port, $retry->())
129 129
130This callback is called when a connection has been successfully established. 130This callback is called when a connection has been successfully established.
131 131
132The peer's numeric host and port (the socket peername) are passed as 132The peer's numeric host and port (the socket peername) are passed as
133parameters, together with a retry callback. 133parameters, together with a retry callback. At the time it is called the
134read and write queues, EOF status, TLS status and similar properties of
135the handle will have been reset.
134 136
137It is not allowed to use the read or write queues while the handle object
138is connecting.
139
135If, for some reason, the handle is not acceptable, calling C<$retry> 140If, for some reason, the handle is not acceptable, calling C<$retry> will
136will continue with the next connection target (in case of multi-homed 141continue with the next connection target (in case of multi-homed hosts or
137hosts or SRV records there can be multiple connection endpoints). At the 142SRV records there can be multiple connection endpoints). The C<$retry>
138time it is called the read and write queues, eof status, tls status and 143callback can be invoked after the connect callback returns, i.e. one can
139similar properties of the handle will have been reset. 144start a handshake and then decide to retry with the next host if the
145handshake fails.
140 146
141In most cases, you should ignore the C<$retry> parameter. 147In most cases, you should ignore the C<$retry> parameter.
142 148
143=item on_connect_error => $cb->($handle, $message) 149=item on_connect_error => $cb->($handle, $message)
144 150
164with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In 170with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
165cases where the other side can close the connection at will, it is 171cases where the other side can close the connection at will, it is
166often easiest to not report C<EPIPE> errors in this callback. 172often easiest to not report C<EPIPE> errors in this callback.
167 173
168AnyEvent::Handle tries to find an appropriate error code for you to check 174AnyEvent::Handle tries to find an appropriate error code for you to check
169against, but in some cases (TLS errors), this does not work well. It is 175against, but in some cases (TLS errors), this does not work well.
170recommended to always output the C<$message> argument in human-readable 176
171error messages (it's usually the same as C<"$!">). 177If you report the error to the user, it is recommended to always output
178the C<$message> argument in human-readable error messages (you don't need
179to report C<"$!"> if you report C<$message>).
180
181If you want to react programmatically to the error, then looking at C<$!>
182and comparing it against some of the documented C<Errno> values is usually
183better than looking at the C<$message>.
172 184
173Non-fatal errors can be retried by returning, but it is recommended 185Non-fatal errors can be retried by returning, but it is recommended
174to simply ignore this parameter and instead abondon the handle object 186to simply ignore this parameter and instead abondon the handle object
175when this callback is invoked. Examples of non-fatal errors are timeouts 187when this callback is invoked. Examples of non-fatal errors are timeouts
176C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>). 188C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
224If an EOF condition has been detected but no C<on_eof> callback has been 236If an EOF condition has been detected but no C<on_eof> callback has been
225set, then a fatal error will be raised with C<$!> set to <0>. 237set, then a fatal error will be raised with C<$!> set to <0>.
226 238
227=item on_drain => $cb->($handle) 239=item on_drain => $cb->($handle)
228 240
229This sets the callback that is called when the write buffer becomes empty 241This sets the callback that is called once when the write buffer becomes
230(or immediately if the buffer is empty already). 242empty (and immediately when the handle object is created).
231 243
232To append to the write buffer, use the C<< ->push_write >> method. 244To append to the write buffer, use the C<< ->push_write >> method.
233 245
234This callback is useful when you don't want to put all of your write data 246This callback is useful when you don't want to put all of your write data
235into the queue at once, for example, when you want to write the contents 247into the queue at once, for example, when you want to write the contents
247many seconds pass without a successful read or write on the underlying 259many seconds pass without a successful read or write on the underlying
248file handle (or a call to C<timeout_reset>), the C<on_timeout> callback 260file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
249will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT> 261will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
250error will be raised). 262error will be raised).
251 263
252There are three variants of the timeouts that work independently 264There are three variants of the timeouts that work independently of each
253of each other, for both read and write, just read, and just write: 265other, for both read and write (triggered when nothing was read I<OR>
266written), just read (triggered when nothing was read), and just write:
254C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks 267C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
255C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions 268C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
256C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>. 269C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
257 270
258Note that timeout processing is active even when you do not have 271Note that timeout processing is active even when you do not have any
259any outstanding read or write requests: If you plan to keep the connection 272outstanding read or write requests: If you plan to keep the connection
260idle then you should disable the timeout temporarily or ignore the timeout 273idle then you should disable the timeout temporarily or ignore the
261in the C<on_timeout> callback, in which case AnyEvent::Handle will simply 274timeout in the corresponding C<on_timeout> callback, in which case
262restart the timeout. 275AnyEvent::Handle will simply restart the timeout.
263 276
264Zero (the default) disables this timeout. 277Zero (the default) disables the corresponding timeout.
265 278
266=item on_timeout => $cb->($handle) 279=item on_timeout => $cb->($handle)
280
281=item on_rtimeout => $cb->($handle)
282
283=item on_wtimeout => $cb->($handle)
267 284
268Called whenever the inactivity timeout passes. If you return from this 285Called whenever the inactivity timeout passes. If you return from this
269callback, then the timeout will be reset as if some activity had happened, 286callback, then the timeout will be reset as if some activity had happened,
270so this condition is not fatal in any way. 287so this condition is not fatal in any way.
271 288
278For example, a server accepting connections from untrusted sources should 295For example, a server accepting connections from untrusted sources should
279be configured to accept only so-and-so much data that it cannot act on 296be configured to accept only so-and-so much data that it cannot act on
280(for example, when expecting a line, an attacker could send an unlimited 297(for example, when expecting a line, an attacker could send an unlimited
281amount of data without a callback ever being called as long as the line 298amount of data without a callback ever being called as long as the line
282isn't finished). 299isn't finished).
300
301=item wbuf_max => <bytes>
302
303If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
304when the write buffer ever (strictly) exceeds this size. This is useful to
305avoid some forms of denial-of-service attacks.
306
307Although the units of this parameter is bytes, this is the I<raw> number
308of bytes not yet accepted by the kernel. This can make a difference when
309you e.g. use TLS, as TLS typically makes your write data larger (but it
310can also make it smaller due to compression).
311
312As an example of when this limit is useful, take a chat server that sends
313chat messages to a client. If the client does not read those in a timely
314manner then the send buffer in the server would grow unbounded.
283 315
284=item autocork => <boolean> 316=item autocork => <boolean>
285 317
286When disabled (the default), C<push_write> will try to immediately 318When disabled (the default), C<push_write> will try to immediately
287write the data to the handle if possible. This avoids having to register 319write the data to the handle if possible. This avoids having to register
339already have occured on BSD systems), but at least it will protect you 371already have occured on BSD systems), but at least it will protect you
340from most attacks. 372from most attacks.
341 373
342=item read_size => <bytes> 374=item read_size => <bytes>
343 375
344The initial read block size, the number of bytes this module will try to 376The initial read block size, the number of bytes this module will try
345read during each loop iteration. Each handle object will consume at least 377to read during each loop iteration. Each handle object will consume
346this amount of memory for the read buffer as well, so when handling many 378at least this amount of memory for the read buffer as well, so when
347connections requirements). See also C<max_read_size>. Default: C<2048>. 379handling many connections watch out for memory requirements). See also
380C<max_read_size>. Default: C<2048>.
348 381
349=item max_read_size => <bytes> 382=item max_read_size => <bytes>
350 383
351The maximum read buffer size used by the dynamic adjustment 384The maximum read buffer size used by the dynamic adjustment
352algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in 385algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
422Use the C<< ->starttls >> method if you need to start TLS negotiation later. 455Use the C<< ->starttls >> method if you need to start TLS negotiation later.
423 456
424=item tls_ctx => $anyevent_tls 457=item tls_ctx => $anyevent_tls
425 458
426Use the given C<AnyEvent::TLS> object to create the new TLS connection 459Use the given C<AnyEvent::TLS> object to create the new TLS connection
427(unless a connection object was specified directly). If this parameter is 460(unless a connection object was specified directly). If this
428missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 461parameter is missing (or C<undef>), then AnyEvent::Handle will use
462C<AnyEvent::Handle::TLS_CTX>.
429 463
430Instead of an object, you can also specify a hash reference with C<< key 464Instead of an object, you can also specify a hash reference with C<< key
431=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a 465=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
432new TLS context object. 466new TLS context object.
433 467
502 $self->{connect}[0], 536 $self->{connect}[0],
503 $self->{connect}[1], 537 $self->{connect}[1],
504 sub { 538 sub {
505 my ($fh, $host, $port, $retry) = @_; 539 my ($fh, $host, $port, $retry) = @_;
506 540
541 delete $self->{_connect}; # no longer needed
542
507 if ($fh) { 543 if ($fh) {
508 $self->{fh} = $fh; 544 $self->{fh} = $fh;
509 545
510 delete $self->{_skip_drain_rbuf}; 546 delete $self->{_skip_drain_rbuf};
511 $self->_start; 547 $self->_start;
518 }); 554 });
519 555
520 } else { 556 } else {
521 if ($self->{on_connect_error}) { 557 if ($self->{on_connect_error}) {
522 $self->{on_connect_error}($self, "$!"); 558 $self->{on_connect_error}($self, "$!");
523 $self->destroy; 559 $self->destroy if $self;
524 } else { 560 } else {
525 $self->_error ($!, 1); 561 $self->_error ($!, 1);
526 } 562 }
527 } 563 }
528 }, 564 },
529 sub { 565 sub {
530 local $self->{fh} = $_[0]; 566 local $self->{fh} = $_[0];
531 567
532 $self->{on_prepare} 568 $self->{on_prepare}
533 ? $self->{on_prepare}->($self) 569 ? $self->{on_prepare}->($self)
534 : () 570 : ()
535 } 571 }
536 ); 572 );
537 } 573 }
538 574
737 773
738=item $handle->rbuf_max ($max_octets) 774=item $handle->rbuf_max ($max_octets)
739 775
740Configures the C<rbuf_max> setting (C<undef> disables it). 776Configures the C<rbuf_max> setting (C<undef> disables it).
741 777
778=item $handle->wbuf_max ($max_octets)
779
780Configures the C<wbuf_max> setting (C<undef> disables it).
781
742=cut 782=cut
743 783
744sub rbuf_max { 784sub rbuf_max {
745 $_[0]{rbuf_max} = $_[1]; 785 $_[0]{rbuf_max} = $_[1];
746} 786}
747 787
788sub wbuf_max {
789 $_[0]{wbuf_max} = $_[1];
790}
791
748############################################################################# 792#############################################################################
749 793
750=item $handle->timeout ($seconds) 794=item $handle->timeout ($seconds)
751 795
752=item $handle->rtimeout ($seconds) 796=item $handle->rtimeout ($seconds)
753 797
754=item $handle->wtimeout ($seconds) 798=item $handle->wtimeout ($seconds)
755 799
756Configures (or disables) the inactivity timeout. 800Configures (or disables) the inactivity timeout.
801
802The timeout will be checked instantly, so this method might destroy the
803handle before it returns.
757 804
758=item $handle->timeout_reset 805=item $handle->timeout_reset
759 806
760=item $handle->rtimeout_reset 807=item $handle->rtimeout_reset
761 808
845 892
846The write queue is very simple: you can add data to its end, and 893The write queue is very simple: you can add data to its end, and
847AnyEvent::Handle will automatically try to get rid of it for you. 894AnyEvent::Handle will automatically try to get rid of it for you.
848 895
849When data could be written and the write buffer is shorter then the low 896When data could be written and the write buffer is shorter then the low
850water mark, the C<on_drain> callback will be invoked. 897water mark, the C<on_drain> callback will be invoked once.
851 898
852=over 4 899=over 4
853 900
854=item $handle->on_drain ($cb) 901=item $handle->on_drain ($cb)
855 902
870 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}); 917 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
871} 918}
872 919
873=item $handle->push_write ($data) 920=item $handle->push_write ($data)
874 921
875Queues the given scalar to be written. You can push as much data as you 922Queues the given scalar to be written. You can push as much data as
876want (only limited by the available memory), as C<AnyEvent::Handle> 923you want (only limited by the available memory and C<wbuf_max>), as
877buffers it independently of the kernel. 924C<AnyEvent::Handle> buffers it independently of the kernel.
878 925
879This method may invoke callbacks (and therefore the handle might be 926This method may invoke callbacks (and therefore the handle might be
880destroyed after it returns). 927destroyed after it returns).
881 928
882=cut 929=cut
910 $cb->() unless $self->{autocork}; 957 $cb->() unless $self->{autocork};
911 958
912 # if still data left in wbuf, we need to poll 959 # if still data left in wbuf, we need to poll
913 $self->{_ww} = AE::io $self->{fh}, 1, $cb 960 $self->{_ww} = AE::io $self->{fh}, 1, $cb
914 if length $self->{wbuf}; 961 if length $self->{wbuf};
962
963 if (
964 defined $self->{wbuf_max}
965 && $self->{wbuf_max} < length $self->{wbuf}
966 ) {
967 $self->_error (Errno::ENOSPC, 1), return;
968 }
915 }; 969 };
916} 970}
917 971
918our %WH; 972our %WH;
919 973
1039=cut 1093=cut
1040 1094
1041register_write_type storable => sub { 1095register_write_type storable => sub {
1042 my ($self, $ref) = @_; 1096 my ($self, $ref) = @_;
1043 1097
1044 require Storable; 1098 require Storable unless $Storable::VERSION;
1045 1099
1046 pack "w/a*", Storable::nfreeze ($ref) 1100 pack "w/a*", Storable::nfreeze ($ref)
1047}; 1101};
1048 1102
1049=back 1103=back
1054before it was actually written. One way to do that is to replace your 1108before it was actually written. One way to do that is to replace your
1055C<on_drain> handler by a callback that shuts down the socket (and set 1109C<on_drain> handler by a callback that shuts down the socket (and set
1056C<low_water_mark> to C<0>). This method is a shorthand for just that, and 1110C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1057replaces the C<on_drain> callback with: 1111replaces the C<on_drain> callback with:
1058 1112
1059 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown 1113 sub { shutdown $_[0]{fh}, 1 }
1060 1114
1061This simply shuts down the write side and signals an EOF condition to the 1115This simply shuts down the write side and signals an EOF condition to the
1062the peer. 1116the peer.
1063 1117
1064You can rely on the normal read queue and C<on_eof> handling 1118You can rely on the normal read queue and C<on_eof> handling
1086 1140
1087Whenever the given C<type> is used, C<push_write> will the function with 1141Whenever the given C<type> is used, C<push_write> will the function with
1088the handle object and the remaining arguments. 1142the handle object and the remaining arguments.
1089 1143
1090The function is supposed to return a single octet string that will be 1144The function is supposed to return a single octet string that will be
1091appended to the write buffer, so you cna mentally treat this function as a 1145appended to the write buffer, so you can mentally treat this function as a
1092"arguments to on-the-wire-format" converter. 1146"arguments to on-the-wire-format" converter.
1093 1147
1094Example: implement a custom write type C<join> that joins the remaining 1148Example: implement a custom write type C<join> that joins the remaining
1095arguments using the first one. 1149arguments using the first one.
1096 1150
1390data. 1444data.
1391 1445
1392Example: read 2 bytes. 1446Example: read 2 bytes.
1393 1447
1394 $handle->push_read (chunk => 2, sub { 1448 $handle->push_read (chunk => 2, sub {
1395 warn "yay ", unpack "H*", $_[1]; 1449 say "yay " . unpack "H*", $_[1];
1396 }); 1450 });
1397 1451
1398=cut 1452=cut
1399 1453
1400register_read_type chunk => sub { 1454register_read_type chunk => sub {
1434 if (@_ < 3) { 1488 if (@_ < 3) {
1435 # this is more than twice as fast as the generic code below 1489 # this is more than twice as fast as the generic code below
1436 sub { 1490 sub {
1437 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return; 1491 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1438 1492
1439 $cb->($_[0], $1, $2); 1493 $cb->($_[0], "$1", "$2");
1440 1 1494 1
1441 } 1495 }
1442 } else { 1496 } else {
1443 $eol = quotemeta $eol unless ref $eol; 1497 $eol = quotemeta $eol unless ref $eol;
1444 $eol = qr|^(.*?)($eol)|s; 1498 $eol = qr|^(.*?)($eol)|s;
1445 1499
1446 sub { 1500 sub {
1447 $_[0]{rbuf} =~ s/$eol// or return; 1501 $_[0]{rbuf} =~ s/$eol// or return;
1448 1502
1449 $cb->($_[0], $1, $2); 1503 $cb->($_[0], "$1", "$2");
1450 1 1504 1
1451 } 1505 }
1452 } 1506 }
1453}; 1507};
1454 1508
1502 1556
1503 sub { 1557 sub {
1504 # accept 1558 # accept
1505 if ($$rbuf =~ $accept) { 1559 if ($$rbuf =~ $accept) {
1506 $data .= substr $$rbuf, 0, $+[0], ""; 1560 $data .= substr $$rbuf, 0, $+[0], "";
1507 $cb->($self, $data); 1561 $cb->($_[0], $data);
1508 return 1; 1562 return 1;
1509 } 1563 }
1510 1564
1511 # reject 1565 # reject
1512 if ($reject && $$rbuf =~ $reject) { 1566 if ($reject && $$rbuf =~ $reject) {
1513 $self->_error (Errno::EBADMSG); 1567 $_[0]->_error (Errno::EBADMSG);
1514 } 1568 }
1515 1569
1516 # skip 1570 # skip
1517 if ($skip && $$rbuf =~ $skip) { 1571 if ($skip && $$rbuf =~ $skip) {
1518 $data .= substr $$rbuf, 0, $+[0], ""; 1572 $data .= substr $$rbuf, 0, $+[0], "";
1534 my ($self, $cb) = @_; 1588 my ($self, $cb) = @_;
1535 1589
1536 sub { 1590 sub {
1537 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1591 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1538 if ($_[0]{rbuf} =~ /[^0-9]/) { 1592 if ($_[0]{rbuf} =~ /[^0-9]/) {
1539 $self->_error (Errno::EBADMSG); 1593 $_[0]->_error (Errno::EBADMSG);
1540 } 1594 }
1541 return; 1595 return;
1542 } 1596 }
1543 1597
1544 my $len = $1; 1598 my $len = $1;
1545 1599
1546 $self->unshift_read (chunk => $len, sub { 1600 $_[0]->unshift_read (chunk => $len, sub {
1547 my $string = $_[1]; 1601 my $string = $_[1];
1548 $_[0]->unshift_read (chunk => 1, sub { 1602 $_[0]->unshift_read (chunk => 1, sub {
1549 if ($_[1] eq ",") { 1603 if ($_[1] eq ",") {
1550 $cb->($_[0], $string); 1604 $cb->($_[0], $string);
1551 } else { 1605 } else {
1552 $self->_error (Errno::EBADMSG); 1606 $_[0]->_error (Errno::EBADMSG);
1553 } 1607 }
1554 }); 1608 });
1555 }); 1609 });
1556 1610
1557 1 1611 1
1630 1684
1631 my $data; 1685 my $data;
1632 my $rbuf = \$self->{rbuf}; 1686 my $rbuf = \$self->{rbuf};
1633 1687
1634 sub { 1688 sub {
1635 my $ref = eval { $json->incr_parse ($self->{rbuf}) }; 1689 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1636 1690
1637 if ($ref) { 1691 if ($ref) {
1638 $self->{rbuf} = $json->incr_text; 1692 $_[0]{rbuf} = $json->incr_text;
1639 $json->incr_text = ""; 1693 $json->incr_text = "";
1640 $cb->($self, $ref); 1694 $cb->($_[0], $ref);
1641 1695
1642 1 1696 1
1643 } elsif ($@) { 1697 } elsif ($@) {
1644 # error case 1698 # error case
1645 $json->incr_skip; 1699 $json->incr_skip;
1646 1700
1647 $self->{rbuf} = $json->incr_text; 1701 $_[0]{rbuf} = $json->incr_text;
1648 $json->incr_text = ""; 1702 $json->incr_text = "";
1649 1703
1650 $self->_error (Errno::EBADMSG); 1704 $_[0]->_error (Errno::EBADMSG);
1651 1705
1652 () 1706 ()
1653 } else { 1707 } else {
1654 $self->{rbuf} = ""; 1708 $_[0]{rbuf} = "";
1655 1709
1656 () 1710 ()
1657 } 1711 }
1658 } 1712 }
1659}; 1713};
1669=cut 1723=cut
1670 1724
1671register_read_type storable => sub { 1725register_read_type storable => sub {
1672 my ($self, $cb) = @_; 1726 my ($self, $cb) = @_;
1673 1727
1674 require Storable; 1728 require Storable unless $Storable::VERSION;
1675 1729
1676 sub { 1730 sub {
1677 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method 1731 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1678 defined (my $len = eval { unpack "w", $_[0]{rbuf} }) 1732 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1679 or return; 1733 or return;
1682 1736
1683 # bypass unshift if we already have the remaining chunk 1737 # bypass unshift if we already have the remaining chunk
1684 if ($format + $len <= length $_[0]{rbuf}) { 1738 if ($format + $len <= length $_[0]{rbuf}) {
1685 my $data = substr $_[0]{rbuf}, $format, $len; 1739 my $data = substr $_[0]{rbuf}, $format, $len;
1686 substr $_[0]{rbuf}, 0, $format + $len, ""; 1740 substr $_[0]{rbuf}, 0, $format + $len, "";
1741
1687 $cb->($_[0], Storable::thaw ($data)); 1742 eval { $cb->($_[0], Storable::thaw ($data)); 1 }
1743 or return $_[0]->_error (Errno::EBADMSG);
1688 } else { 1744 } else {
1689 # remove prefix 1745 # remove prefix
1690 substr $_[0]{rbuf}, 0, $format, ""; 1746 substr $_[0]{rbuf}, 0, $format, "";
1691 1747
1692 # read remaining chunk 1748 # read remaining chunk
1693 $_[0]->unshift_read (chunk => $len, sub { 1749 $_[0]->unshift_read (chunk => $len, sub {
1694 if (my $ref = eval { Storable::thaw ($_[1]) }) { 1750 eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1695 $cb->($_[0], $ref);
1696 } else {
1697 $self->_error (Errno::EBADMSG); 1751 or $_[0]->_error (Errno::EBADMSG);
1698 }
1699 }); 1752 });
1700 } 1753 }
1701 1754
1702 1 1755 1
1703 } 1756 }
1740Note that AnyEvent::Handle will automatically C<start_read> for you when 1793Note that AnyEvent::Handle will automatically C<start_read> for you when
1741you change the C<on_read> callback or push/unshift a read callback, and it 1794you change the C<on_read> callback or push/unshift a read callback, and it
1742will automatically C<stop_read> for you when neither C<on_read> is set nor 1795will automatically C<stop_read> for you when neither C<on_read> is set nor
1743there are any read requests in the queue. 1796there are any read requests in the queue.
1744 1797
1745These methods will have no effect when in TLS mode (as TLS doesn't support 1798In older versions of this module (<= 5.3), these methods had no effect,
1746half-duplex connections). 1799as TLS does not support half-duplex connections. In current versions they
1800work as expected, as this behaviour is required to avoid certain resource
1801attacks, where the program would be forced to read (and buffer) arbitrary
1802amounts of data before being able to send some data. The drawback is that
1803some readings of the the SSL/TLS specifications basically require this
1804attack to be working, as SSL/TLS implementations might stall sending data
1805during a rehandshake.
1806
1807As a guideline, during the initial handshake, you should not stop reading,
1808and as a client, it might cause problems, depending on your application.
1747 1809
1748=cut 1810=cut
1749 1811
1750sub stop_read { 1812sub stop_read {
1751 my ($self) = @_; 1813 my ($self) = @_;
1752 1814
1753 delete $self->{_rw} unless $self->{tls}; 1815 delete $self->{_rw};
1754} 1816}
1755 1817
1756sub start_read { 1818sub start_read {
1757 my ($self) = @_; 1819 my ($self) = @_;
1758 1820
1799 my ($self, $err) = @_; 1861 my ($self, $err) = @_;
1800 1862
1801 return $self->_error ($!, 1) 1863 return $self->_error ($!, 1)
1802 if $err == Net::SSLeay::ERROR_SYSCALL (); 1864 if $err == Net::SSLeay::ERROR_SYSCALL ();
1803 1865
1804 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ()); 1866 my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1805 1867
1806 # reduce error string to look less scary 1868 # reduce error string to look less scary
1807 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /; 1869 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1808 1870
1809 if ($self->{_on_starttls}) { 1871 if ($self->{_on_starttls}) {
1960 Net::SSLeay::CTX_set_mode ($tls, 1|2); 2022 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1961 2023
1962 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2024 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1963 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2025 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1964 2026
1965 Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf}); 2027 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2028 $self->{rbuf} = "";
1966 2029
1967 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio}); 2030 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1968 2031
1969 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) } 2032 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1970 if $self->{on_starttls}; 2033 if $self->{on_starttls};
2007 $self->{tls_ctx}->_put_session (delete $self->{tls}) 2070 $self->{tls_ctx}->_put_session (delete $self->{tls})
2008 if $self->{tls} > 0; 2071 if $self->{tls} > 0;
2009 2072
2010 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)}; 2073 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
2011} 2074}
2075
2076=item $handle->resettls
2077
2078This rarely-used method simply resets and TLS state on the handle, usually
2079causing data loss.
2080
2081One case where it may be useful is when you want to skip over the data in
2082the stream but you are not interested in interpreting it, so data loss is
2083no concern.
2084
2085=cut
2086
2087*resettls = \&_freetls;
2012 2088
2013sub DESTROY { 2089sub DESTROY {
2014 my ($self) = @_; 2090 my ($self) = @_;
2015 2091
2016 &_freetls; 2092 &_freetls;
2132 2208
2133It is only safe to "forget" the reference inside EOF or error callbacks, 2209It is only safe to "forget" the reference inside EOF or error callbacks,
2134from within all other callbacks, you need to explicitly call the C<< 2210from within all other callbacks, you need to explicitly call the C<<
2135->destroy >> method. 2211->destroy >> method.
2136 2212
2213=item Why is my C<on_eof> callback never called?
2214
2215Probably because your C<on_error> callback is being called instead: When
2216you have outstanding requests in your read queue, then an EOF is
2217considered an error as you clearly expected some data.
2218
2219To avoid this, make sure you have an empty read queue whenever your handle
2220is supposed to be "idle" (i.e. connection closes are O.K.). You can set
2221an C<on_read> handler that simply pushes the first read requests in the
2222queue.
2223
2224See also the next question, which explains this in a bit more detail.
2225
2226=item How can I serve requests in a loop?
2227
2228Most protocols consist of some setup phase (authentication for example)
2229followed by a request handling phase, where the server waits for requests
2230and handles them, in a loop.
2231
2232There are two important variants: The first (traditional, better) variant
2233handles requests until the server gets some QUIT command, causing it to
2234close the connection first (highly desirable for a busy TCP server). A
2235client dropping the connection is an error, which means this variant can
2236detect an unexpected detection close.
2237
2238To handle this case, always make sure you have a on-empty read queue, by
2239pushing the "read request start" handler on it:
2240
2241 # we assume a request starts with a single line
2242 my @start_request; @start_request = (line => sub {
2243 my ($hdl, $line) = @_;
2244
2245 ... handle request
2246
2247 # push next request read, possibly from a nested callback
2248 $hdl->push_read (@start_request);
2249 });
2250
2251 # auth done, now go into request handling loop
2252 # now push the first @start_request
2253 $hdl->push_read (@start_request);
2254
2255By always having an outstanding C<push_read>, the handle always expects
2256some data and raises the C<EPIPE> error when the connction is dropped
2257unexpectedly.
2258
2259The second variant is a protocol where the client can drop the connection
2260at any time. For TCP, this means that the server machine may run out of
2261sockets easier, and in general, it means you cannot distinguish a protocl
2262failure/client crash from a normal connection close. Nevertheless, these
2263kinds of protocols are common (and sometimes even the best solution to the
2264problem).
2265
2266Having an outstanding read request at all times is possible if you ignore
2267C<EPIPE> errors, but this doesn't help with when the client drops the
2268connection during a request, which would still be an error.
2269
2270A better solution is to push the initial request read in an C<on_read>
2271callback. This avoids an error, as when the server doesn't expect data
2272(i.e. is idly waiting for the next request, an EOF will not raise an
2273error, but simply result in an C<on_eof> callback. It is also a bit slower
2274and simpler:
2275
2276 # auth done, now go into request handling loop
2277 $hdl->on_read (sub {
2278 my ($hdl) = @_;
2279
2280 # called each time we receive data but the read queue is empty
2281 # simply start read the request
2282
2283 $hdl->push_read (line => sub {
2284 my ($hdl, $line) = @_;
2285
2286 ... handle request
2287
2288 # do nothing special when the request has been handled, just
2289 # let the request queue go empty.
2290 });
2291 });
2292
2137=item I get different callback invocations in TLS mode/Why can't I pause 2293=item I get different callback invocations in TLS mode/Why can't I pause
2138reading? 2294reading?
2139 2295
2140Unlike, say, TCP, TLS connections do not consist of two independent 2296Unlike, say, TCP, TLS connections do not consist of two independent
2141communication channels, one for each direction. Or put differently, the 2297communication channels, one for each direction. Or put differently, the
2162 $handle->on_eof (undef); 2318 $handle->on_eof (undef);
2163 $handle->on_error (sub { 2319 $handle->on_error (sub {
2164 my $data = delete $_[0]{rbuf}; 2320 my $data = delete $_[0]{rbuf};
2165 }); 2321 });
2166 2322
2323Note that this example removes the C<rbuf> member from the handle object,
2324which is not normally allowed by the API. It is expressly permitted in
2325this case only, as the handle object needs to be destroyed afterwards.
2326
2167The reason to use C<on_error> is that TCP connections, due to latencies 2327The reason to use C<on_error> is that TCP connections, due to latencies
2168and packets loss, might get closed quite violently with an error, when in 2328and packets loss, might get closed quite violently with an error, when in
2169fact all data has been received. 2329fact all data has been received.
2170 2330
2171It is usually better to use acknowledgements when transferring data, 2331It is usually better to use acknowledgements when transferring data,
2181C<low_water_mark> this will be called precisely when all data has been 2341C<low_water_mark> this will be called precisely when all data has been
2182written to the socket: 2342written to the socket:
2183 2343
2184 $handle->push_write (...); 2344 $handle->push_write (...);
2185 $handle->on_drain (sub { 2345 $handle->on_drain (sub {
2186 warn "all data submitted to the kernel\n"; 2346 AE::log debug => "All data submitted to the kernel.";
2187 undef $handle; 2347 undef $handle;
2188 }); 2348 });
2189 2349
2190If you just want to queue some data and then signal EOF to the other side, 2350If you just want to queue some data and then signal EOF to the other side,
2191consider using C<< ->push_shutdown >> instead. 2351consider using C<< ->push_shutdown >> instead.
2275When you have intermediate CA certificates that your clients might not 2435When you have intermediate CA certificates that your clients might not
2276know about, just append them to the C<cert_file>. 2436know about, just append them to the C<cert_file>.
2277 2437
2278=back 2438=back
2279 2439
2280
2281=head1 SUBCLASSING AnyEvent::Handle 2440=head1 SUBCLASSING AnyEvent::Handle
2282 2441
2283In many cases, you might want to subclass AnyEvent::Handle. 2442In many cases, you might want to subclass AnyEvent::Handle.
2284 2443
2285To make this easier, a given version of AnyEvent::Handle uses these 2444To make this easier, a given version of AnyEvent::Handle uses these
2311 2470
2312Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 2471Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
2313 2472
2314=cut 2473=cut
2315 2474
23161; # End of AnyEvent::Handle 24751
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