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Revision 1.5 by elmex, Mon Apr 28 08:01:05 2008 UTC vs.
Revision 1.223 by root, Thu Sep 1 04:07:18 2011 UTC

1package AnyEvent::Handle;
2
3use warnings;
4use strict;
5
6use AnyEvent;
7use IO::Handle;
8use Errno qw/EAGAIN EINTR/;
9
10=head1 NAME 1=head1 NAME
11 2
12AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
13
14=head1 VERSION
15
16Version 0.01
17
18=cut
19
20our $VERSION = '0.01';
21 4
22=head1 SYNOPSIS 5=head1 SYNOPSIS
23 6
24 use AnyEvent; 7 use AnyEvent;
25 use AnyEvent::Handle; 8 use AnyEvent::Handle;
26 9
27 my $cv = AnyEvent->condvar; 10 my $cv = AnyEvent->condvar;
28 11
29 my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN); 12 my $hdl; $hdl = new AnyEvent::Handle
13 fh => \*STDIN,
14 on_error => sub {
15 my ($hdl, $fatal, $msg) = @_;
16 AE::log warn => "got error $msg\n";
17 $hdl->destroy;
18 $cv->send;
19 };
30 20
31 $ae_fh->on_eof (sub { $cv->broadcast }); 21 # send some request line
22 $hdl->push_write ("getinfo\015\012");
32 23
33 $ae_fh->readlines (sub { 24 # read the response line
25 $hdl->push_read (line => sub {
34 my ($ae_fh, @lines) = @_; 26 my ($hdl, $line) = @_;
35 for (@lines) { 27 AE::log warn => "got line <$line>\n";
28 $cv->send;
29 });
30
31 $cv->recv;
32
33=head1 DESCRIPTION
34
35This is a helper module to make it easier to do event-based I/O on
36stream-based filehandles (sockets, pipes, and other stream things).
37
38The L<AnyEvent::Intro> tutorial contains some well-documented
39AnyEvent::Handle examples.
40
41In the following, where the documentation refers to "bytes", it means
42characters. As sysread and syswrite are used for all I/O, their
43treatment of characters applies to this module as well.
44
45At the very minimum, you should specify C<fh> or C<connect>, and the
46C<on_error> callback.
47
48All callbacks will be invoked with the handle object as their first
49argument.
50
51=cut
52
53package AnyEvent::Handle;
54
55use Scalar::Util ();
56use List::Util ();
57use Carp ();
58use Errno qw(EAGAIN EINTR);
59
60use AnyEvent (); BEGIN { AnyEvent::common_sense }
61use AnyEvent::Util qw(WSAEWOULDBLOCK);
62
63our $VERSION = $AnyEvent::VERSION;
64
65sub _load_func($) {
66 my $func = $_[0];
67
68 unless (defined &$func) {
69 my $pkg = $func;
70 do {
71 $pkg =~ s/::[^:]+$//
72 or return;
73 eval "require $pkg";
74 } until defined &$func;
75 }
76
77 \&$func
78}
79
80sub MAX_READ_SIZE() { 131072 }
81
82=head1 METHODS
83
84=over 4
85
86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
87
88The constructor supports these arguments (all as C<< key => value >> pairs).
89
90=over 4
91
92=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
93
94The filehandle this L<AnyEvent::Handle> object will operate on.
95NOTE: The filehandle will be set to non-blocking mode (using
96C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
97that mode.
98
99=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
100
101Try to connect to the specified host and service (port), using
102C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
103default C<peername>.
104
105You have to specify either this parameter, or C<fh>, above.
106
107It is possible to push requests on the read and write queues, and modify
108properties of the stream, even while AnyEvent::Handle is connecting.
109
110When this parameter is specified, then the C<on_prepare>,
111C<on_connect_error> and C<on_connect> callbacks will be called under the
112appropriate circumstances:
113
114=over 4
115
116=item on_prepare => $cb->($handle)
117
118This (rarely used) callback is called before a new connection is
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
121file handle with parameters required for the actual connect (as opposed to
122settings that can be changed when the connection is already established).
123
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
126default timeout is to be used).
127
128=item on_connect => $cb->($handle, $host, $port, $retry->())
129
130This callback is called when a connection has been successfully established.
131
132The peer's numeric host and port (the socket peername) are passed as
133parameters, together with a retry callback.
134
135If, for some reason, the handle is not acceptable, calling C<$retry>
136will continue with the next connection target (in case of multi-homed
137hosts or SRV records there can be multiple connection endpoints). At the
138time it is called the read and write queues, eof status, tls status and
139similar properties of the handle will have been reset.
140
141In most cases, you should ignore the C<$retry> parameter.
142
143=item on_connect_error => $cb->($handle, $message)
144
145This callback is called when the connection could not be
146established. C<$!> will contain the relevant error code, and C<$message> a
147message describing it (usually the same as C<"$!">).
148
149If this callback isn't specified, then C<on_error> will be called with a
150fatal error instead.
151
152=back
153
154=item on_error => $cb->($handle, $fatal, $message)
155
156This is the error callback, which is called when, well, some error
157occured, such as not being able to resolve the hostname, failure to
158connect, or a read error.
159
160Some errors are fatal (which is indicated by C<$fatal> being true). On
161fatal errors the handle object will be destroyed (by a call to C<< ->
162destroy >>) after invoking the error callback (which means you are free to
163examine the handle object). Examples of fatal errors are an EOF condition
164with 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
166often easiest to not report C<EPIPE> errors in this callback.
167
168AnyEvent::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
170recommended to always output the C<$message> argument in human-readable
171error messages (it's usually the same as C<"$!">).
172
173Non-fatal errors can be retried by returning, but it is recommended
174to simply ignore this parameter and instead abondon the handle object
175when this callback is invoked. Examples of non-fatal errors are timeouts
176C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
177
178On entry to the callback, the value of C<$!> contains the operating
179system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
180C<EPROTO>).
181
182While not mandatory, it is I<highly> recommended to set this callback, as
183you will not be notified of errors otherwise. The default just calls
184C<croak>.
185
186=item on_read => $cb->($handle)
187
188This sets the default read callback, which is called when data arrives
189and no read request is in the queue (unlike read queue callbacks, this
190callback will only be called when at least one octet of data is in the
191read buffer).
192
193To access (and remove data from) the read buffer, use the C<< ->rbuf >>
194method or access the C<< $handle->{rbuf} >> member directly. Note that you
195must not enlarge or modify the read buffer, you can only remove data at
196the beginning from it.
197
198You can also call C<< ->push_read (...) >> or any other function that
199modifies the read queue. Or do both. Or ...
200
201When an EOF condition is detected, AnyEvent::Handle will first try to
202feed all the remaining data to the queued callbacks and C<on_read> before
203calling the C<on_eof> callback. If no progress can be made, then a fatal
204error will be raised (with C<$!> set to C<EPIPE>).
205
206Note that, unlike requests in the read queue, an C<on_read> callback
207doesn't mean you I<require> some data: if there is an EOF and there
208are outstanding read requests then an error will be flagged. With an
209C<on_read> callback, the C<on_eof> callback will be invoked.
210
211=item on_eof => $cb->($handle)
212
213Set the callback to be called when an end-of-file condition is detected,
214i.e. in the case of a socket, when the other side has closed the
215connection cleanly, and there are no outstanding read requests in the
216queue (if there are read requests, then an EOF counts as an unexpected
217connection close and will be flagged as an error).
218
219For sockets, this just means that the other side has stopped sending data,
220you can still try to write data, and, in fact, one can return from the EOF
221callback and continue writing data, as only the read part has been shut
222down.
223
224If 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>.
226
227=item on_drain => $cb->($handle)
228
229This sets the callback that is called when the write buffer becomes empty
230(or immediately if the buffer is empty already).
231
232To append to the write buffer, use the C<< ->push_write >> method.
233
234This 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
236of some file to the socket you might not want to read the whole file into
237memory and push it into the queue, but instead only read more data from
238the file when the write queue becomes empty.
239
240=item timeout => $fractional_seconds
241
242=item rtimeout => $fractional_seconds
243
244=item wtimeout => $fractional_seconds
245
246If non-zero, then these enables an "inactivity" timeout: whenever this
247many 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
249will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
250error will be raised).
251
252There are three variants of the timeouts that work independently of each
253other, for both read and write (triggered when nothing was read I<OR>
254written), just read (triggered when nothing was read), and just write:
255C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
256C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
257C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
258
259Note that timeout processing is active even when you do not have any
260outstanding read or write requests: If you plan to keep the connection
261idle then you should disable the timeout temporarily or ignore the
262timeout in the corresponding C<on_timeout> callback, in which case
263AnyEvent::Handle will simply restart the timeout.
264
265Zero (the default) disables the corresponding timeout.
266
267=item on_timeout => $cb->($handle)
268
269=item on_rtimeout => $cb->($handle)
270
271=item on_wtimeout => $cb->($handle)
272
273Called whenever the inactivity timeout passes. If you return from this
274callback, then the timeout will be reset as if some activity had happened,
275so this condition is not fatal in any way.
276
277=item rbuf_max => <bytes>
278
279If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
280when the read buffer ever (strictly) exceeds this size. This is useful to
281avoid some forms of denial-of-service attacks.
282
283For example, a server accepting connections from untrusted sources should
284be configured to accept only so-and-so much data that it cannot act on
285(for example, when expecting a line, an attacker could send an unlimited
286amount of data without a callback ever being called as long as the line
287isn't finished).
288
289=item wbuf_max => <bytes>
290
291If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
292when the write buffer ever (strictly) exceeds this size. This is useful to
293avoid some forms of denial-of-service attacks.
294
295Although the units of this parameter is bytes, this is the I<raw> number
296of bytes not yet accepted by the kernel. This can make a difference when
297you e.g. use TLS, as TLS typically makes your write data larger (but it
298can also make it smaller due to compression).
299
300As an example of when this limit is useful, take a chat server that sends
301chat messages to a client. If the client does not read those in a timely
302manner then the send buffer in the server would grow unbounded.
303
304=item autocork => <boolean>
305
306When disabled (the default), C<push_write> will try to immediately
307write the data to the handle if possible. This avoids having to register
308a write watcher and wait for the next event loop iteration, but can
309be inefficient if you write multiple small chunks (on the wire, this
310disadvantage is usually avoided by your kernel's nagle algorithm, see
311C<no_delay>, but this option can save costly syscalls).
312
313When enabled, writes will always be queued till the next event loop
314iteration. This is efficient when you do many small writes per iteration,
315but less efficient when you do a single write only per iteration (or when
316the write buffer often is full). It also increases write latency.
317
318=item no_delay => <boolean>
319
320When doing small writes on sockets, your operating system kernel might
321wait a bit for more data before actually sending it out. This is called
322the Nagle algorithm, and usually it is beneficial.
323
324In some situations you want as low a delay as possible, which can be
325accomplishd by setting this option to a true value.
326
327The default is your operating system's default behaviour (most likely
328enabled). This option explicitly enables or disables it, if possible.
329
330=item keepalive => <boolean>
331
332Enables (default disable) the SO_KEEPALIVE option on the stream socket:
333normally, TCP connections have no time-out once established, so TCP
334connections, once established, can stay alive forever even when the other
335side has long gone. TCP keepalives are a cheap way to take down long-lived
336TCP connections when the other side becomes unreachable. While the default
337is OS-dependent, TCP keepalives usually kick in after around two hours,
338and, if the other side doesn't reply, take down the TCP connection some 10
339to 15 minutes later.
340
341It is harmless to specify this option for file handles that do not support
342keepalives, and enabling it on connections that are potentially long-lived
343is usually a good idea.
344
345=item oobinline => <boolean>
346
347BSD majorly fucked up the implementation of TCP urgent data. The result
348is that almost no OS implements TCP according to the specs, and every OS
349implements it slightly differently.
350
351If you want to handle TCP urgent data, then setting this flag (the default
352is enabled) gives you the most portable way of getting urgent data, by
353putting it into the stream.
354
355Since BSD emulation of OOB data on top of TCP's urgent data can have
356security implications, AnyEvent::Handle sets this flag automatically
357unless explicitly specified. Note that setting this flag after
358establishing a connection I<may> be a bit too late (data loss could
359already have occured on BSD systems), but at least it will protect you
360from most attacks.
361
362=item read_size => <bytes>
363
364The initial read block size, the number of bytes this module will try
365to read during each loop iteration. Each handle object will consume
366at least this amount of memory for the read buffer as well, so when
367handling many connections watch out for memory requirements). See also
368C<max_read_size>. Default: C<2048>.
369
370=item max_read_size => <bytes>
371
372The maximum read buffer size used by the dynamic adjustment
373algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
374one go it will double C<read_size> up to the maximum given by this
375option. Default: C<131072> or C<read_size>, whichever is higher.
376
377=item low_water_mark => <bytes>
378
379Sets the number of bytes (default: C<0>) that make up an "empty" write
380buffer: If the buffer reaches this size or gets even samller it is
381considered empty.
382
383Sometimes it can be beneficial (for performance reasons) to add data to
384the write buffer before it is fully drained, but this is a rare case, as
385the operating system kernel usually buffers data as well, so the default
386is good in almost all cases.
387
388=item linger => <seconds>
389
390If this is non-zero (default: C<3600>), the destructor of the
391AnyEvent::Handle object will check whether there is still outstanding
392write data and will install a watcher that will write this data to the
393socket. No errors will be reported (this mostly matches how the operating
394system treats outstanding data at socket close time).
395
396This will not work for partial TLS data that could not be encoded
397yet. This data will be lost. Calling the C<stoptls> method in time might
398help.
399
400=item peername => $string
401
402A string used to identify the remote site - usually the DNS hostname
403(I<not> IDN!) used to create the connection, rarely the IP address.
404
405Apart from being useful in error messages, this string is also used in TLS
406peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
407verification will be skipped when C<peername> is not specified or is
408C<undef>.
409
410=item tls => "accept" | "connect" | Net::SSLeay::SSL object
411
412When this parameter is given, it enables TLS (SSL) mode, that means
413AnyEvent will start a TLS handshake as soon as the connection has been
414established and will transparently encrypt/decrypt data afterwards.
415
416All TLS protocol errors will be signalled as C<EPROTO>, with an
417appropriate error message.
418
419TLS mode requires Net::SSLeay to be installed (it will be loaded
420automatically when you try to create a TLS handle): this module doesn't
421have a dependency on that module, so if your module requires it, you have
422to add the dependency yourself.
423
424Unlike TCP, TLS has a server and client side: for the TLS server side, use
425C<accept>, and for the TLS client side of a connection, use C<connect>
426mode.
427
428You can also provide your own TLS connection object, but you have
429to make sure that you call either C<Net::SSLeay::set_connect_state>
430or C<Net::SSLeay::set_accept_state> on it before you pass it to
431AnyEvent::Handle. Also, this module will take ownership of this connection
432object.
433
434At some future point, AnyEvent::Handle might switch to another TLS
435implementation, then the option to use your own session object will go
436away.
437
438B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
439passing in the wrong integer will lead to certain crash. This most often
440happens when one uses a stylish C<< tls => 1 >> and is surprised about the
441segmentation fault.
442
443Use the C<< ->starttls >> method if you need to start TLS negotiation later.
444
445=item tls_ctx => $anyevent_tls
446
447Use the given C<AnyEvent::TLS> object to create the new TLS connection
448(unless a connection object was specified directly). If this
449parameter is missing (or C<undef>), then AnyEvent::Handle will use
450C<AnyEvent::Handle::TLS_CTX>.
451
452Instead of an object, you can also specify a hash reference with C<< key
453=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
454new TLS context object.
455
456=item on_starttls => $cb->($handle, $success[, $error_message])
457
458This callback will be invoked when the TLS/SSL handshake has finished. If
459C<$success> is true, then the TLS handshake succeeded, otherwise it failed
460(C<on_stoptls> will not be called in this case).
461
462The session in C<< $handle->{tls} >> can still be examined in this
463callback, even when the handshake was not successful.
464
465TLS handshake failures will not cause C<on_error> to be invoked when this
466callback is in effect, instead, the error message will be passed to C<on_starttls>.
467
468Without this callback, handshake failures lead to C<on_error> being
469called as usual.
470
471Note that you cannot just call C<starttls> again in this callback. If you
472need to do that, start an zero-second timer instead whose callback can
473then call C<< ->starttls >> again.
474
475=item on_stoptls => $cb->($handle)
476
477When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
478set, then it will be invoked after freeing the TLS session. If it is not,
479then a TLS shutdown condition will be treated like a normal EOF condition
480on the handle.
481
482The session in C<< $handle->{tls} >> can still be examined in this
483callback.
484
485This callback will only be called on TLS shutdowns, not when the
486underlying handle signals EOF.
487
488=item json => JSON or JSON::XS object
489
490This is the json coder object used by the C<json> read and write types.
491
492If you don't supply it, then AnyEvent::Handle will create and use a
493suitable one (on demand), which will write and expect UTF-8 encoded JSON
494texts.
495
496Note that you are responsible to depend on the JSON module if you want to
497use this functionality, as AnyEvent does not have a dependency itself.
498
499=back
500
501=cut
502
503sub new {
504 my $class = shift;
505 my $self = bless { @_ }, $class;
506
507 if ($self->{fh}) {
508 $self->_start;
509 return unless $self->{fh}; # could be gone by now
510
511 } elsif ($self->{connect}) {
512 require AnyEvent::Socket;
513
514 $self->{peername} = $self->{connect}[0]
515 unless exists $self->{peername};
516
517 $self->{_skip_drain_rbuf} = 1;
518
519 {
520 Scalar::Util::weaken (my $self = $self);
521
522 $self->{_connect} =
523 AnyEvent::Socket::tcp_connect (
524 $self->{connect}[0],
525 $self->{connect}[1],
526 sub {
527 my ($fh, $host, $port, $retry) = @_;
528
529 delete $self->{_connect}; # no longer needed
530
531 if ($fh) {
532 $self->{fh} = $fh;
533
534 delete $self->{_skip_drain_rbuf};
535 $self->_start;
536
537 $self->{on_connect}
538 and $self->{on_connect}($self, $host, $port, sub {
539 delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
540 $self->{_skip_drain_rbuf} = 1;
541 &$retry;
542 });
543
544 } else {
545 if ($self->{on_connect_error}) {
546 $self->{on_connect_error}($self, "$!");
547 $self->destroy if $self;
548 } else {
549 $self->_error ($!, 1);
550 }
551 }
552 },
553 sub {
554 local $self->{fh} = $_[0];
555
556 $self->{on_prepare}
557 ? $self->{on_prepare}->($self)
558 : ()
559 }
560 );
561 }
562
563 } else {
564 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
565 }
566
567 $self
568}
569
570sub _start {
571 my ($self) = @_;
572
573 # too many clueless people try to use udp and similar sockets
574 # with AnyEvent::Handle, do them a favour.
575 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
576 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
577 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
578
579 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
580
581 $self->{_activity} =
582 $self->{_ractivity} =
583 $self->{_wactivity} = AE::now;
584
585 $self->{read_size} ||= 2048;
586 $self->{max_read_size} = $self->{read_size}
587 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
588
589 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
590 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
591 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
592
593 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
594 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
595
596 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
597
598 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
599 if $self->{tls};
600
601 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
602
603 $self->start_read
604 if $self->{on_read} || @{ $self->{_queue} };
605
606 $self->_drain_wbuf;
607}
608
609sub _error {
610 my ($self, $errno, $fatal, $message) = @_;
611
612 $! = $errno;
613 $message ||= "$!";
614
615 if ($self->{on_error}) {
616 $self->{on_error}($self, $fatal, $message);
617 $self->destroy if $fatal;
618 } elsif ($self->{fh} || $self->{connect}) {
619 $self->destroy;
620 Carp::croak "AnyEvent::Handle uncaught error: $message";
621 }
622}
623
624=item $fh = $handle->fh
625
626This method returns the file handle used to create the L<AnyEvent::Handle> object.
627
628=cut
629
630sub fh { $_[0]{fh} }
631
632=item $handle->on_error ($cb)
633
634Replace the current C<on_error> callback (see the C<on_error> constructor argument).
635
636=cut
637
638sub on_error {
639 $_[0]{on_error} = $_[1];
640}
641
642=item $handle->on_eof ($cb)
643
644Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
645
646=cut
647
648sub on_eof {
649 $_[0]{on_eof} = $_[1];
650}
651
652=item $handle->on_timeout ($cb)
653
654=item $handle->on_rtimeout ($cb)
655
656=item $handle->on_wtimeout ($cb)
657
658Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
659callback, or disables the callback (but not the timeout) if C<$cb> =
660C<undef>. See the C<timeout> constructor argument and method.
661
662=cut
663
664# see below
665
666=item $handle->autocork ($boolean)
667
668Enables or disables the current autocork behaviour (see C<autocork>
669constructor argument). Changes will only take effect on the next write.
670
671=cut
672
673sub autocork {
674 $_[0]{autocork} = $_[1];
675}
676
677=item $handle->no_delay ($boolean)
678
679Enables or disables the C<no_delay> setting (see constructor argument of
680the same name for details).
681
682=cut
683
684sub no_delay {
685 $_[0]{no_delay} = $_[1];
686
687 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
688 if $_[0]{fh};
689}
690
691=item $handle->keepalive ($boolean)
692
693Enables or disables the C<keepalive> setting (see constructor argument of
694the same name for details).
695
696=cut
697
698sub keepalive {
699 $_[0]{keepalive} = $_[1];
700
701 eval {
702 local $SIG{__DIE__};
703 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
704 if $_[0]{fh};
705 };
706}
707
708=item $handle->oobinline ($boolean)
709
710Enables or disables the C<oobinline> setting (see constructor argument of
711the same name for details).
712
713=cut
714
715sub oobinline {
716 $_[0]{oobinline} = $_[1];
717
718 eval {
719 local $SIG{__DIE__};
720 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
721 if $_[0]{fh};
722 };
723}
724
725=item $handle->keepalive ($boolean)
726
727Enables or disables the C<keepalive> setting (see constructor argument of
728the same name for details).
729
730=cut
731
732sub keepalive {
733 $_[0]{keepalive} = $_[1];
734
735 eval {
736 local $SIG{__DIE__};
737 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
738 if $_[0]{fh};
739 };
740}
741
742=item $handle->on_starttls ($cb)
743
744Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
745
746=cut
747
748sub on_starttls {
749 $_[0]{on_starttls} = $_[1];
750}
751
752=item $handle->on_stoptls ($cb)
753
754Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
755
756=cut
757
758sub on_stoptls {
759 $_[0]{on_stoptls} = $_[1];
760}
761
762=item $handle->rbuf_max ($max_octets)
763
764Configures the C<rbuf_max> setting (C<undef> disables it).
765
766=item $handle->wbuf_max ($max_octets)
767
768Configures the C<wbuf_max> setting (C<undef> disables it).
769
770=cut
771
772sub rbuf_max {
773 $_[0]{rbuf_max} = $_[1];
774}
775
776sub wbuf_max {
777 $_[0]{wbuf_max} = $_[1];
778}
779
780#############################################################################
781
782=item $handle->timeout ($seconds)
783
784=item $handle->rtimeout ($seconds)
785
786=item $handle->wtimeout ($seconds)
787
788Configures (or disables) the inactivity timeout.
789
790The timeout will be checked instantly, so this method might destroy the
791handle before it returns.
792
793=item $handle->timeout_reset
794
795=item $handle->rtimeout_reset
796
797=item $handle->wtimeout_reset
798
799Reset the activity timeout, as if data was received or sent.
800
801These methods are cheap to call.
802
803=cut
804
805for my $dir ("", "r", "w") {
806 my $timeout = "${dir}timeout";
807 my $tw = "_${dir}tw";
808 my $on_timeout = "on_${dir}timeout";
809 my $activity = "_${dir}activity";
810 my $cb;
811
812 *$on_timeout = sub {
813 $_[0]{$on_timeout} = $_[1];
814 };
815
816 *$timeout = sub {
817 my ($self, $new_value) = @_;
818
819 $new_value >= 0
820 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
821
822 $self->{$timeout} = $new_value;
823 delete $self->{$tw}; &$cb;
824 };
825
826 *{"${dir}timeout_reset"} = sub {
827 $_[0]{$activity} = AE::now;
828 };
829
830 # main workhorse:
831 # reset the timeout watcher, as neccessary
832 # also check for time-outs
833 $cb = sub {
834 my ($self) = @_;
835
836 if ($self->{$timeout} && $self->{fh}) {
837 my $NOW = AE::now;
838
839 # when would the timeout trigger?
840 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
841
842 # now or in the past already?
843 if ($after <= 0) {
844 $self->{$activity} = $NOW;
845
846 if ($self->{$on_timeout}) {
847 $self->{$on_timeout}($self);
848 } else {
849 $self->_error (Errno::ETIMEDOUT);
850 }
851
852 # callback could have changed timeout value, optimise
853 return unless $self->{$timeout};
854
855 # calculate new after
856 $after = $self->{$timeout};
857 }
858
859 Scalar::Util::weaken $self;
860 return unless $self; # ->error could have destroyed $self
861
862 $self->{$tw} ||= AE::timer $after, 0, sub {
863 delete $self->{$tw};
864 $cb->($self);
36 chomp; 865 };
37 print "Line: $_"; 866 } else {
867 delete $self->{$tw};
868 }
869 }
870}
871
872#############################################################################
873
874=back
875
876=head2 WRITE QUEUE
877
878AnyEvent::Handle manages two queues per handle, one for writing and one
879for reading.
880
881The write queue is very simple: you can add data to its end, and
882AnyEvent::Handle will automatically try to get rid of it for you.
883
884When data could be written and the write buffer is shorter then the low
885water mark, the C<on_drain> callback will be invoked.
886
887=over 4
888
889=item $handle->on_drain ($cb)
890
891Sets the C<on_drain> callback or clears it (see the description of
892C<on_drain> in the constructor).
893
894This method may invoke callbacks (and therefore the handle might be
895destroyed after it returns).
896
897=cut
898
899sub on_drain {
900 my ($self, $cb) = @_;
901
902 $self->{on_drain} = $cb;
903
904 $cb->($self)
905 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
906}
907
908=item $handle->push_write ($data)
909
910Queues the given scalar to be written. You can push as much data as
911you want (only limited by the available memory and C<wbuf_max>), as
912C<AnyEvent::Handle> buffers it independently of the kernel.
913
914This method may invoke callbacks (and therefore the handle might be
915destroyed after it returns).
916
917=cut
918
919sub _drain_wbuf {
920 my ($self) = @_;
921
922 if (!$self->{_ww} && length $self->{wbuf}) {
923
924 Scalar::Util::weaken $self;
925
926 my $cb = sub {
927 my $len = syswrite $self->{fh}, $self->{wbuf};
928
929 if (defined $len) {
930 substr $self->{wbuf}, 0, $len, "";
931
932 $self->{_activity} = $self->{_wactivity} = AE::now;
933
934 $self->{on_drain}($self)
935 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
936 && $self->{on_drain};
937
938 delete $self->{_ww} unless length $self->{wbuf};
939 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
940 $self->_error ($!, 1);
941 }
942 };
943
944 # try to write data immediately
945 $cb->() unless $self->{autocork};
946
947 # if still data left in wbuf, we need to poll
948 $self->{_ww} = AE::io $self->{fh}, 1, $cb
949 if length $self->{wbuf};
950
951 if (
952 defined $self->{wbuf_max}
953 && $self->{wbuf_max} < length $self->{wbuf}
954 ) {
955 $self->_error (Errno::ENOSPC, 1), return;
956 }
957 };
958}
959
960our %WH;
961
962# deprecated
963sub register_write_type($$) {
964 $WH{$_[0]} = $_[1];
965}
966
967sub push_write {
968 my $self = shift;
969
970 if (@_ > 1) {
971 my $type = shift;
972
973 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
974 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
975 ->($self, @_);
976 }
977
978 # we downgrade here to avoid hard-to-track-down bugs,
979 # and diagnose the problem earlier and better.
980
981 if ($self->{tls}) {
982 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
983 &_dotls ($self) if $self->{fh};
984 } else {
985 utf8::downgrade $self->{wbuf} .= $_[0];
986 $self->_drain_wbuf if $self->{fh};
987 }
988}
989
990=item $handle->push_write (type => @args)
991
992Instead of formatting your data yourself, you can also let this module
993do the job by specifying a type and type-specific arguments. You
994can also specify the (fully qualified) name of a package, in which
995case AnyEvent tries to load the package and then expects to find the
996C<anyevent_write_type> function inside (see "custom write types", below).
997
998Predefined types are (if you have ideas for additional types, feel free to
999drop by and tell us):
1000
1001=over 4
1002
1003=item netstring => $string
1004
1005Formats the given value as netstring
1006(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
1007
1008=cut
1009
1010register_write_type netstring => sub {
1011 my ($self, $string) = @_;
1012
1013 (length $string) . ":$string,"
1014};
1015
1016=item packstring => $format, $data
1017
1018An octet string prefixed with an encoded length. The encoding C<$format>
1019uses the same format as a Perl C<pack> format, but must specify a single
1020integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1021optional C<!>, C<< < >> or C<< > >> modifier).
1022
1023=cut
1024
1025register_write_type packstring => sub {
1026 my ($self, $format, $string) = @_;
1027
1028 pack "$format/a*", $string
1029};
1030
1031=item json => $array_or_hashref
1032
1033Encodes the given hash or array reference into a JSON object. Unless you
1034provide your own JSON object, this means it will be encoded to JSON text
1035in UTF-8.
1036
1037JSON objects (and arrays) are self-delimiting, so you can write JSON at
1038one end of a handle and read them at the other end without using any
1039additional framing.
1040
1041The generated JSON text is guaranteed not to contain any newlines: While
1042this module doesn't need delimiters after or between JSON texts to be
1043able to read them, many other languages depend on that.
1044
1045A simple RPC protocol that interoperates easily with others is to send
1046JSON arrays (or objects, although arrays are usually the better choice as
1047they mimic how function argument passing works) and a newline after each
1048JSON text:
1049
1050 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
1051 $handle->push_write ("\012");
1052
1053An AnyEvent::Handle receiver would simply use the C<json> read type and
1054rely on the fact that the newline will be skipped as leading whitespace:
1055
1056 $handle->push_read (json => sub { my $array = $_[1]; ... });
1057
1058Other languages could read single lines terminated by a newline and pass
1059this line into their JSON decoder of choice.
1060
1061=cut
1062
1063sub json_coder() {
1064 eval { require JSON::XS; JSON::XS->new->utf8 }
1065 || do { require JSON; JSON->new->utf8 }
1066}
1067
1068register_write_type json => sub {
1069 my ($self, $ref) = @_;
1070
1071 my $json = $self->{json} ||= json_coder;
1072
1073 $json->encode ($ref)
1074};
1075
1076=item storable => $reference
1077
1078Freezes the given reference using L<Storable> and writes it to the
1079handle. Uses the C<nfreeze> format.
1080
1081=cut
1082
1083register_write_type storable => sub {
1084 my ($self, $ref) = @_;
1085
1086 require Storable;
1087
1088 pack "w/a*", Storable::nfreeze ($ref)
1089};
1090
1091=back
1092
1093=item $handle->push_shutdown
1094
1095Sometimes you know you want to close the socket after writing your data
1096before it was actually written. One way to do that is to replace your
1097C<on_drain> handler by a callback that shuts down the socket (and set
1098C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1099replaces the C<on_drain> callback with:
1100
1101 sub { shutdown $_[0]{fh}, 1 }
1102
1103This simply shuts down the write side and signals an EOF condition to the
1104the peer.
1105
1106You can rely on the normal read queue and C<on_eof> handling
1107afterwards. This is the cleanest way to close a connection.
1108
1109This method may invoke callbacks (and therefore the handle might be
1110destroyed after it returns).
1111
1112=cut
1113
1114sub push_shutdown {
1115 my ($self) = @_;
1116
1117 delete $self->{low_water_mark};
1118 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
1119}
1120
1121=item custom write types - Package::anyevent_write_type $handle, @args
1122
1123Instead of one of the predefined types, you can also specify the name of
1124a package. AnyEvent will try to load the package and then expects to find
1125a function named C<anyevent_write_type> inside. If it isn't found, it
1126progressively tries to load the parent package until it either finds the
1127function (good) or runs out of packages (bad).
1128
1129Whenever the given C<type> is used, C<push_write> will the function with
1130the handle object and the remaining arguments.
1131
1132The function is supposed to return a single octet string that will be
1133appended to the write buffer, so you can mentally treat this function as a
1134"arguments to on-the-wire-format" converter.
1135
1136Example: implement a custom write type C<join> that joins the remaining
1137arguments using the first one.
1138
1139 $handle->push_write (My::Type => " ", 1,2,3);
1140
1141 # uses the following package, which can be defined in the "My::Type" or in
1142 # the "My" modules to be auto-loaded, or just about anywhere when the
1143 # My::Type::anyevent_write_type is defined before invoking it.
1144
1145 package My::Type;
1146
1147 sub anyevent_write_type {
1148 my ($handle, $delim, @args) = @_;
1149
1150 join $delim, @args
1151 }
1152
1153=cut
1154
1155#############################################################################
1156
1157=back
1158
1159=head2 READ QUEUE
1160
1161AnyEvent::Handle manages two queues per handle, one for writing and one
1162for reading.
1163
1164The read queue is more complex than the write queue. It can be used in two
1165ways, the "simple" way, using only C<on_read> and the "complex" way, using
1166a queue.
1167
1168In the simple case, you just install an C<on_read> callback and whenever
1169new data arrives, it will be called. You can then remove some data (if
1170enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
1171leave the data there if you want to accumulate more (e.g. when only a
1172partial message has been received so far), or change the read queue with
1173e.g. C<push_read>.
1174
1175In the more complex case, you want to queue multiple callbacks. In this
1176case, AnyEvent::Handle will call the first queued callback each time new
1177data arrives (also the first time it is queued) and remove it when it has
1178done its job (see C<push_read>, below).
1179
1180This way you can, for example, push three line-reads, followed by reading
1181a chunk of data, and AnyEvent::Handle will execute them in order.
1182
1183Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
1184the specified number of bytes which give an XML datagram.
1185
1186 # in the default state, expect some header bytes
1187 $handle->on_read (sub {
1188 # some data is here, now queue the length-header-read (4 octets)
1189 shift->unshift_read (chunk => 4, sub {
1190 # header arrived, decode
1191 my $len = unpack "N", $_[1];
1192
1193 # now read the payload
1194 shift->unshift_read (chunk => $len, sub {
1195 my $xml = $_[1];
1196 # handle xml
1197 });
1198 });
1199 });
1200
1201Example 2: Implement a client for a protocol that replies either with "OK"
1202and another line or "ERROR" for the first request that is sent, and 64
1203bytes for the second request. Due to the availability of a queue, we can
1204just pipeline sending both requests and manipulate the queue as necessary
1205in the callbacks.
1206
1207When the first callback is called and sees an "OK" response, it will
1208C<unshift> another line-read. This line-read will be queued I<before> the
120964-byte chunk callback.
1210
1211 # request one, returns either "OK + extra line" or "ERROR"
1212 $handle->push_write ("request 1\015\012");
1213
1214 # we expect "ERROR" or "OK" as response, so push a line read
1215 $handle->push_read (line => sub {
1216 # if we got an "OK", we have to _prepend_ another line,
1217 # so it will be read before the second request reads its 64 bytes
1218 # which are already in the queue when this callback is called
1219 # we don't do this in case we got an error
1220 if ($_[1] eq "OK") {
1221 $_[0]->unshift_read (line => sub {
1222 my $response = $_[1];
1223 ...
1224 });
38 } 1225 }
39 }); 1226 });
40 1227
41 # or use the constructor to pass the callback: 1228 # request two, simply returns 64 octets
1229 $handle->push_write ("request 2\015\012");
42 1230
43 my $ae_fh2 = 1231 # simply read 64 bytes, always
44 AnyEvent::Handle->new ( 1232 $handle->push_read (chunk => 64, sub {
45 fh => \*STDIN, 1233 my $response = $_[1];
46 on_eof => sub { 1234 ...
47 $cv->broadcast; 1235 });
48 }, 1236
49 on_readline => sub { 1237=over 4
50 my ($ae_fh, @lines) = @_; 1238
51 for (@lines) { 1239=cut
52 chomp; 1240
53 print "Line: $_"; 1241sub _drain_rbuf {
1242 my ($self) = @_;
1243
1244 # avoid recursion
1245 return if $self->{_skip_drain_rbuf};
1246 local $self->{_skip_drain_rbuf} = 1;
1247
1248 while () {
1249 # we need to use a separate tls read buffer, as we must not receive data while
1250 # we are draining the buffer, and this can only happen with TLS.
1251 $self->{rbuf} .= delete $self->{_tls_rbuf}
1252 if exists $self->{_tls_rbuf};
1253
1254 my $len = length $self->{rbuf};
1255
1256 if (my $cb = shift @{ $self->{_queue} }) {
1257 unless ($cb->($self)) {
1258 # no progress can be made
1259 # (not enough data and no data forthcoming)
1260 $self->_error (Errno::EPIPE, 1), return
1261 if $self->{_eof};
1262
1263 unshift @{ $self->{_queue} }, $cb;
54 } 1264 last;
55 } 1265 }
56 );
57
58 $cv->wait;
59
60=head1 DESCRIPTION
61
62This module is a helper module to make it easier to do non-blocking I/O
63on filehandles (and sockets, see L<AnyEvent::Socket>).
64
65The event loop is provided by L<AnyEvent>.
66
67=head1 METHODS
68
69=over 4
70
71=item B<new (%args)>
72
73The constructor has these arguments:
74
75=over 4
76
77=item fh => $filehandle
78
79The filehandle this L<AnyEvent::Handle> object will operate on.
80
81NOTE: The filehandle will be set to non-blocking.
82
83=item read_block_size => $size
84
85The default read block size use for reads via the C<on_read>
86method.
87
88=item on_read => $cb
89
90=item on_eof => $cb
91
92=item on_error => $cb
93
94These are shortcuts, that will call the corresponding method and set the callback to C<$cb>.
95
96=item on_readline => $cb
97
98The C<readlines> method is called with the default seperator and C<$cb> as callback
99for you.
100
101=back
102
103=cut
104
105sub new {
106 my $this = shift;
107 my $class = ref($this) || $this;
108 my $self = {
109 read_block_size => 4096,
110 rbuf => '',
111 @_
112 };
113 bless $self, $class;
114
115 $self->{fh}->blocking (0) if $self->{fh};
116
117 if ($self->{on_read}) {
118 $self->on_read ($self->{on_read});
119
120 } elsif ($self->{on_readline}) { 1266 } elsif ($self->{on_read}) {
121 $self->readlines ($self->{on_readline}); 1267 last unless $len;
122 1268
1269 $self->{on_read}($self);
1270
1271 if (
1272 $len == length $self->{rbuf} # if no data has been consumed
1273 && !@{ $self->{_queue} } # and the queue is still empty
1274 && $self->{on_read} # but we still have on_read
1275 ) {
1276 # no further data will arrive
1277 # so no progress can be made
1278 $self->_error (Errno::EPIPE, 1), return
1279 if $self->{_eof};
1280
1281 last; # more data might arrive
1282 }
1283 } else {
1284 # read side becomes idle
1285 delete $self->{_rw} unless $self->{tls};
1286 last;
1287 }
1288 }
1289
123 } elsif ($self->{on_eof}) { 1290 if ($self->{_eof}) {
124 $self->on_eof ($self->{on_eof}); 1291 $self->{on_eof}
1292 ? $self->{on_eof}($self)
1293 : $self->_error (0, 1, "Unexpected end-of-file");
125 1294
126 } elsif ($self->{on_error}) { 1295 return;
127 $self->on_eof ($self->{on_error});
128 } 1296 }
129 1297
130 return $self 1298 if (
131} 1299 defined $self->{rbuf_max}
1300 && $self->{rbuf_max} < length $self->{rbuf}
1301 ) {
1302 $self->_error (Errno::ENOSPC, 1), return;
1303 }
132 1304
133=item B<fh> 1305 # may need to restart read watcher
1306 unless ($self->{_rw}) {
1307 $self->start_read
1308 if $self->{on_read} || @{ $self->{_queue} };
1309 }
1310}
134 1311
135This method returns the filehandle of the L<AnyEvent::Handle> object. 1312=item $handle->on_read ($cb)
136 1313
137=cut 1314This replaces the currently set C<on_read> callback, or clears it (when
1315the new callback is C<undef>). See the description of C<on_read> in the
1316constructor.
138 1317
139sub fh { $_[0]->{fh} } 1318This method may invoke callbacks (and therefore the handle might be
140 1319destroyed after it returns).
141=item B<on_read ($callback)>
142
143This method installs a C<$callback> that will be called
144when new data arrived. You can access the read buffer via the C<rbuf>
145method (see below).
146
147The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
148 1320
149=cut 1321=cut
150 1322
151sub on_read { 1323sub on_read {
152 my ($self, $cb) = @_; 1324 my ($self, $cb) = @_;
1325
153 $self->{on_read} = $cb; 1326 $self->{on_read} = $cb;
1327 $self->_drain_rbuf if $cb;
1328}
154 1329
155 unless (defined $self->{on_read}) { 1330=item $handle->rbuf
156 delete $self->{on_read_w}; 1331
1332Returns the read buffer (as a modifiable lvalue). You can also access the
1333read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1334much faster, and no less clean).
1335
1336The only operation allowed on the read buffer (apart from looking at it)
1337is removing data from its beginning. Otherwise modifying or appending to
1338it is not allowed and will lead to hard-to-track-down bugs.
1339
1340NOTE: The read buffer should only be used or modified in the C<on_read>
1341callback or when C<push_read> or C<unshift_read> are used with a single
1342callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1343will manage the read buffer on their own.
1344
1345=cut
1346
1347sub rbuf : lvalue {
1348 $_[0]{rbuf}
1349}
1350
1351=item $handle->push_read ($cb)
1352
1353=item $handle->unshift_read ($cb)
1354
1355Append the given callback to the end of the queue (C<push_read>) or
1356prepend it (C<unshift_read>).
1357
1358The callback is called each time some additional read data arrives.
1359
1360It must check whether enough data is in the read buffer already.
1361
1362If not enough data is available, it must return the empty list or a false
1363value, in which case it will be called repeatedly until enough data is
1364available (or an error condition is detected).
1365
1366If enough data was available, then the callback must remove all data it is
1367interested in (which can be none at all) and return a true value. After returning
1368true, it will be removed from the queue.
1369
1370These methods may invoke callbacks (and therefore the handle might be
1371destroyed after it returns).
1372
1373=cut
1374
1375our %RH;
1376
1377sub register_read_type($$) {
1378 $RH{$_[0]} = $_[1];
1379}
1380
1381sub push_read {
1382 my $self = shift;
1383 my $cb = pop;
1384
1385 if (@_) {
1386 my $type = shift;
1387
1388 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1389 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
1390 ->($self, $cb, @_);
1391 }
1392
1393 push @{ $self->{_queue} }, $cb;
1394 $self->_drain_rbuf;
1395}
1396
1397sub unshift_read {
1398 my $self = shift;
1399 my $cb = pop;
1400
1401 if (@_) {
1402 my $type = shift;
1403
1404 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1405 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
1406 ->($self, $cb, @_);
1407 }
1408
1409 unshift @{ $self->{_queue} }, $cb;
1410 $self->_drain_rbuf;
1411}
1412
1413=item $handle->push_read (type => @args, $cb)
1414
1415=item $handle->unshift_read (type => @args, $cb)
1416
1417Instead of providing a callback that parses the data itself you can chose
1418between a number of predefined parsing formats, for chunks of data, lines
1419etc. You can also specify the (fully qualified) name of a package, in
1420which case AnyEvent tries to load the package and then expects to find the
1421C<anyevent_read_type> function inside (see "custom read types", below).
1422
1423Predefined types are (if you have ideas for additional types, feel free to
1424drop by and tell us):
1425
1426=over 4
1427
1428=item chunk => $octets, $cb->($handle, $data)
1429
1430Invoke the callback only once C<$octets> bytes have been read. Pass the
1431data read to the callback. The callback will never be called with less
1432data.
1433
1434Example: read 2 bytes.
1435
1436 $handle->push_read (chunk => 2, sub {
1437 AE::log debug => "yay " . unpack "H*", $_[1];
1438 });
1439
1440=cut
1441
1442register_read_type chunk => sub {
1443 my ($self, $cb, $len) = @_;
1444
1445 sub {
1446 $len <= length $_[0]{rbuf} or return;
1447 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
1448 1
1449 }
1450};
1451
1452=item line => [$eol, ]$cb->($handle, $line, $eol)
1453
1454The callback will be called only once a full line (including the end of
1455line marker, C<$eol>) has been read. This line (excluding the end of line
1456marker) will be passed to the callback as second argument (C<$line>), and
1457the end of line marker as the third argument (C<$eol>).
1458
1459The end of line marker, C<$eol>, can be either a string, in which case it
1460will be interpreted as a fixed record end marker, or it can be a regex
1461object (e.g. created by C<qr>), in which case it is interpreted as a
1462regular expression.
1463
1464The end of line marker argument C<$eol> is optional, if it is missing (NOT
1465undef), then C<qr|\015?\012|> is used (which is good for most internet
1466protocols).
1467
1468Partial lines at the end of the stream will never be returned, as they are
1469not marked by the end of line marker.
1470
1471=cut
1472
1473register_read_type line => sub {
1474 my ($self, $cb, $eol) = @_;
1475
1476 if (@_ < 3) {
1477 # this is more than twice as fast as the generic code below
1478 sub {
1479 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1480
1481 $cb->($_[0], $1, $2);
1482 1
1483 }
1484 } else {
1485 $eol = quotemeta $eol unless ref $eol;
1486 $eol = qr|^(.*?)($eol)|s;
1487
1488 sub {
1489 $_[0]{rbuf} =~ s/$eol// or return;
1490
1491 $cb->($_[0], $1, $2);
1492 1
1493 }
1494 }
1495};
1496
1497=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
1498
1499Makes a regex match against the regex object C<$accept> and returns
1500everything up to and including the match.
1501
1502Example: read a single line terminated by '\n'.
1503
1504 $handle->push_read (regex => qr<\n>, sub { ... });
1505
1506If C<$reject> is given and not undef, then it determines when the data is
1507to be rejected: it is matched against the data when the C<$accept> regex
1508does not match and generates an C<EBADMSG> error when it matches. This is
1509useful to quickly reject wrong data (to avoid waiting for a timeout or a
1510receive buffer overflow).
1511
1512Example: expect a single decimal number followed by whitespace, reject
1513anything else (not the use of an anchor).
1514
1515 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1516
1517If C<$skip> is given and not C<undef>, then it will be matched against
1518the receive buffer when neither C<$accept> nor C<$reject> match,
1519and everything preceding and including the match will be accepted
1520unconditionally. This is useful to skip large amounts of data that you
1521know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1522have to start matching from the beginning. This is purely an optimisation
1523and is usually worth it only when you expect more than a few kilobytes.
1524
1525Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1526expect the header to be very large (it isn't in practice, but...), we use
1527a skip regex to skip initial portions. The skip regex is tricky in that
1528it only accepts something not ending in either \015 or \012, as these are
1529required for the accept regex.
1530
1531 $handle->push_read (regex =>
1532 qr<\015\012\015\012>,
1533 undef, # no reject
1534 qr<^.*[^\015\012]>,
1535 sub { ... });
1536
1537=cut
1538
1539register_read_type regex => sub {
1540 my ($self, $cb, $accept, $reject, $skip) = @_;
1541
1542 my $data;
1543 my $rbuf = \$self->{rbuf};
1544
1545 sub {
1546 # accept
1547 if ($$rbuf =~ $accept) {
1548 $data .= substr $$rbuf, 0, $+[0], "";
1549 $cb->($_[0], $data);
1550 return 1;
1551 }
1552
1553 # reject
1554 if ($reject && $$rbuf =~ $reject) {
1555 $_[0]->_error (Errno::EBADMSG);
1556 }
1557
1558 # skip
1559 if ($skip && $$rbuf =~ $skip) {
1560 $data .= substr $$rbuf, 0, $+[0], "";
1561 }
1562
1563 ()
1564 }
1565};
1566
1567=item netstring => $cb->($handle, $string)
1568
1569A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1570
1571Throws an error with C<$!> set to EBADMSG on format violations.
1572
1573=cut
1574
1575register_read_type netstring => sub {
1576 my ($self, $cb) = @_;
1577
1578 sub {
1579 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1580 if ($_[0]{rbuf} =~ /[^0-9]/) {
1581 $_[0]->_error (Errno::EBADMSG);
1582 }
157 return; 1583 return;
1584 }
1585
1586 my $len = $1;
1587
1588 $_[0]->unshift_read (chunk => $len, sub {
1589 my $string = $_[1];
1590 $_[0]->unshift_read (chunk => 1, sub {
1591 if ($_[1] eq ",") {
1592 $cb->($_[0], $string);
1593 } else {
1594 $_[0]->_error (Errno::EBADMSG);
1595 }
1596 });
1597 });
1598
1599 1
1600 }
1601};
1602
1603=item packstring => $format, $cb->($handle, $string)
1604
1605An octet string prefixed with an encoded length. The encoding C<$format>
1606uses the same format as a Perl C<pack> format, but must specify a single
1607integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1608optional C<!>, C<< < >> or C<< > >> modifier).
1609
1610For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1611EPP uses a prefix of C<N> (4 octtes).
1612
1613Example: read a block of data prefixed by its length in BER-encoded
1614format (very efficient).
1615
1616 $handle->push_read (packstring => "w", sub {
1617 my ($handle, $data) = @_;
158 } 1618 });
159 1619
160 $self->{on_read_w} = 1620=cut
161 AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub { 1621
162 #d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n"; 1622register_read_type packstring => sub {
1623 my ($self, $cb, $format) = @_;
1624
1625 sub {
1626 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1627 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1628 or return;
1629
1630 $format = length pack $format, $len;
1631
1632 # bypass unshift if we already have the remaining chunk
1633 if ($format + $len <= length $_[0]{rbuf}) {
1634 my $data = substr $_[0]{rbuf}, $format, $len;
1635 substr $_[0]{rbuf}, 0, $format + $len, "";
1636 $cb->($_[0], $data);
1637 } else {
1638 # remove prefix
1639 substr $_[0]{rbuf}, 0, $format, "";
1640
1641 # read remaining chunk
1642 $_[0]->unshift_read (chunk => $len, $cb);
1643 }
1644
1645 1
1646 }
1647};
1648
1649=item json => $cb->($handle, $hash_or_arrayref)
1650
1651Reads a JSON object or array, decodes it and passes it to the
1652callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1653
1654If a C<json> object was passed to the constructor, then that will be used
1655for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1656
1657This read type uses the incremental parser available with JSON version
16582.09 (and JSON::XS version 2.2) and above. You have to provide a
1659dependency on your own: this module will load the JSON module, but
1660AnyEvent does not depend on it itself.
1661
1662Since JSON texts are fully self-delimiting, the C<json> read and write
1663types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1664the C<json> write type description, above, for an actual example.
1665
1666=cut
1667
1668register_read_type json => sub {
1669 my ($self, $cb) = @_;
1670
1671 my $json = $self->{json} ||= json_coder;
1672
1673 my $data;
163 my $rbuf_len = length $self->{rbuf}; 1674 my $rbuf = \$self->{rbuf};
164 my $l; 1675
1676 sub {
1677 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1678
1679 if ($ref) {
1680 $_[0]{rbuf} = $json->incr_text;
1681 $json->incr_text = "";
1682 $cb->($_[0], $ref);
1683
1684 1
1685 } elsif ($@) {
1686 # error case
1687 $json->incr_skip;
1688
1689 $_[0]{rbuf} = $json->incr_text;
1690 $json->incr_text = "";
1691
1692 $_[0]->_error (Errno::EBADMSG);
1693
1694 ()
1695 } else {
1696 $_[0]{rbuf} = "";
1697
1698 ()
1699 }
1700 }
1701};
1702
1703=item storable => $cb->($handle, $ref)
1704
1705Deserialises a L<Storable> frozen representation as written by the
1706C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1707data).
1708
1709Raises C<EBADMSG> error if the data could not be decoded.
1710
1711=cut
1712
1713register_read_type storable => sub {
1714 my ($self, $cb) = @_;
1715
1716 require Storable;
1717
1718 sub {
1719 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1720 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1721 or return;
1722
1723 my $format = length pack "w", $len;
1724
1725 # bypass unshift if we already have the remaining chunk
1726 if ($format + $len <= length $_[0]{rbuf}) {
1727 my $data = substr $_[0]{rbuf}, $format, $len;
1728 substr $_[0]{rbuf}, 0, $format + $len, "";
1729 $cb->($_[0], Storable::thaw ($data));
1730 } else {
1731 # remove prefix
1732 substr $_[0]{rbuf}, 0, $format, "";
1733
1734 # read remaining chunk
1735 $_[0]->unshift_read (chunk => $len, sub {
1736 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1737 $cb->($_[0], $ref);
1738 } else {
1739 $_[0]->_error (Errno::EBADMSG);
1740 }
1741 });
1742 }
1743
1744 1
1745 }
1746};
1747
1748=back
1749
1750=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1751
1752Instead of one of the predefined types, you can also specify the name
1753of a package. AnyEvent will try to load the package and then expects to
1754find a function named C<anyevent_read_type> inside. If it isn't found, it
1755progressively tries to load the parent package until it either finds the
1756function (good) or runs out of packages (bad).
1757
1758Whenever this type is used, C<push_read> will invoke the function with the
1759handle object, the original callback and the remaining arguments.
1760
1761The function is supposed to return a callback (usually a closure) that
1762works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1763mentally treat the function as a "configurable read type to read callback"
1764converter.
1765
1766It should invoke the original callback when it is done reading (remember
1767to pass C<$handle> as first argument as all other callbacks do that,
1768although there is no strict requirement on this).
1769
1770For examples, see the source of this module (F<perldoc -m
1771AnyEvent::Handle>, search for C<register_read_type>)).
1772
1773=item $handle->stop_read
1774
1775=item $handle->start_read
1776
1777In rare cases you actually do not want to read anything from the
1778socket. In this case you can call C<stop_read>. Neither C<on_read> nor
1779any queued callbacks will be executed then. To start reading again, call
1780C<start_read>.
1781
1782Note that AnyEvent::Handle will automatically C<start_read> for you when
1783you change the C<on_read> callback or push/unshift a read callback, and it
1784will automatically C<stop_read> for you when neither C<on_read> is set nor
1785there are any read requests in the queue.
1786
1787In older versions of this module (<= 5.3), these methods had no effect,
1788as TLS does not support half-duplex connections. In current versions they
1789work as expected, as this behaviour is required to avoid certain resource
1790attacks, where the program would be forced to read (and buffer) arbitrary
1791amounts of data before being able to send some data. The drawback is that
1792some readings of the the SSL/TLS specifications basically require this
1793attack to be working, as SSL/TLS implementations might stall sending data
1794during a rehandshake.
1795
1796As a guideline, during the initial handshake, you should not stop reading,
1797and as a client, it might cause problems, depending on your applciation.
1798
1799=cut
1800
1801sub stop_read {
1802 my ($self) = @_;
1803
1804 delete $self->{_rw};
1805}
1806
1807sub start_read {
1808 my ($self) = @_;
1809
1810 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1811 Scalar::Util::weaken $self;
1812
1813 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1814 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1815 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1816
1817 if ($len > 0) {
1818 $self->{_activity} = $self->{_ractivity} = AE::now;
1819
1820 if ($self->{tls}) {
1821 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1822
1823 &_dotls ($self);
1824 } else {
1825 $self->_drain_rbuf;
1826 }
1827
165 if (defined $self->{read_size}) { 1828 if ($len == $self->{read_size}) {
166 $l = sysread $self->{fh}, $self->{rbuf}, 1829 $self->{read_size} *= 2;
167 ($self->{read_size} - $rbuf_len), $rbuf_len; 1830 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1831 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1832 }
1833
1834 } elsif (defined $len) {
1835 delete $self->{_rw};
1836 $self->{_eof} = 1;
1837 $self->_drain_rbuf;
1838
1839 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1840 return $self->_error ($!, 1);
1841 }
1842 };
1843 }
1844}
1845
1846our $ERROR_SYSCALL;
1847our $ERROR_WANT_READ;
1848
1849sub _tls_error {
1850 my ($self, $err) = @_;
1851
1852 return $self->_error ($!, 1)
1853 if $err == Net::SSLeay::ERROR_SYSCALL ();
1854
1855 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1856
1857 # reduce error string to look less scary
1858 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1859
1860 if ($self->{_on_starttls}) {
1861 (delete $self->{_on_starttls})->($self, undef, $err);
1862 &_freetls;
1863 } else {
1864 &_freetls;
1865 $self->_error (Errno::EPROTO, 1, $err);
1866 }
1867}
1868
1869# poll the write BIO and send the data if applicable
1870# also decode read data if possible
1871# this is basiclaly our TLS state machine
1872# more efficient implementations are possible with openssl,
1873# but not with the buggy and incomplete Net::SSLeay.
1874sub _dotls {
1875 my ($self) = @_;
1876
1877 my $tmp;
1878
1879 if (length $self->{_tls_wbuf}) {
1880 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1881 substr $self->{_tls_wbuf}, 0, $tmp, "";
1882 }
1883
1884 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1885 return $self->_tls_error ($tmp)
1886 if $tmp != $ERROR_WANT_READ
1887 && ($tmp != $ERROR_SYSCALL || $!);
1888 }
1889
1890 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1891 unless (length $tmp) {
1892 $self->{_on_starttls}
1893 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1894 &_freetls;
1895
1896 if ($self->{on_stoptls}) {
1897 $self->{on_stoptls}($self);
1898 return;
168 } else { 1899 } else {
169 $l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len; 1900 # let's treat SSL-eof as we treat normal EOF
170 }
171 #d# warn "READL $l [$self->{rbuf}]\n";
172
173 if (not defined $l) {
174 return if $! == EAGAIN || $! == EINTR;
175 $self->{on_error}->($self) if $self->{on_error};
176 delete $self->{on_read_w}; 1901 delete $self->{_rw};
177
178 } elsif ($l == 0) {
179 $self->{on_eof}->($self) if $self->{on_eof};
180 delete $self->{on_read_w};
181
182 } else {
183 $self->{on_read}->($self);
184 }
185 });
186}
187
188=item B<on_error ($callback)>
189
190Whenever a read or write operation resulted in an error the C<$callback>
191will be called.
192
193The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself.
194The error is given as errno in C<$!>.
195
196=cut
197
198sub on_error {
199 $_[0]->{on_error} = $_[1];
200}
201
202=item B<on_eof ($callback)>
203
204Installs the C<$callback> that will be called when the end of file is
205encountered in a read operation this C<$callback> will be called. The first
206argument will be the L<AnyEvent::Handle> object itself.
207
208=cut
209
210sub on_eof {
211 $_[0]->{on_eof} = $_[1];
212}
213
214=item B<rbuf>
215
216Returns a reference to the read buffer.
217
218NOTE: The read buffer should only be used or modified if the C<on_read>
219method is used directly. The C<read> and C<readlines> methods will provide
220the read data to their callbacks.
221
222=cut
223
224sub rbuf : lvalue {
225 $_[0]->{rbuf}
226}
227
228=item B<read ($len, $callback)>
229
230Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
231if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
232object itself and the second argument the read data.
233
234NOTE: This method will override any callbacks installed via the C<on_read> method.
235
236=cut
237
238sub read {
239 my ($self, $len, $cb) = @_;
240
241 $self->{read_cb} = $cb;
242 my $old_blk_size = $self->{read_block_size};
243 $self->{read_block_size} = $len;
244
245 $self->on_read (sub {
246 #d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247
248 if ($len == length $_[0]->{rbuf}) {
249 $_[0]->{read_block_size} = $old_blk_size;
250 $_[0]->on_read (undef);
251 $_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
252 }
253 });
254}
255
256=item B<readlines ($callback)>
257
258=item B<readlines ($sep, $callback)>
259
260This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
261if C<$sep> is not provided. C<$sep> will be used as "line" seperator.
262
263The C<$callback> will be called when at least one
264line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
265object itself and the rest of the arguments will be the read lines.
266
267NOTE: This method will override any callbacks installed via the C<on_read> method.
268
269=cut
270
271sub readlines {
272 my ($self, $sep, $cb) = @_;
273
274 if (ref $sep) {
275 $cb = $sep;
276 $sep = "\n";
277
278 } elsif (not defined $sep) {
279 $sep = "\n";
280 }
281
282 my $sep_len = length $sep;
283
284 $self->{on_readline} = $cb;
285
286 $self->on_read (sub {
287 my @lines;
288 my $rb = \$_[0]->{rbuf};
289 my $pos;
290 while (($pos = index ($$rb, $sep)) >= 0) {
291 push @lines, substr $$rb, 0, $pos + $sep_len, '';
292 }
293 $self->{on_readline}->($_[0], @lines);
294 });
295}
296
297=item B<write ($data)>
298
299=item B<write ($callback)>
300
301=item B<write ($data, $callback)>
302
303This method will write C<$data> to the filehandle and call the C<$callback>
304afterwards. If only C<$callback> is provided it will be called when the
305write buffer becomes empty the next time (or immediately if it already is empty).
306
307=cut
308
309sub write {
310 my ($self, $data, $cb) = @_;
311 if (ref $data) { $cb = $data; undef $data }
312 push @{$self->{write_bufs}}, [$data, $cb];
313 $self->_check_writer;
314}
315
316sub _check_writer {
317 my ($self) = @_;
318
319 if ($self->{write_w}) {
320 unless ($self->{write_cb}) {
321 while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
322 my $wba = shift @{$self->{write_bufs}};
323 $self->{wbuf} .= $wba->[0]; 1902 $self->{_eof} = 1;
324 } 1903 }
325 } 1904 }
326 return;
327 }
328 1905
329 my $wba = shift @{$self->{write_bufs}} 1906 $self->{_tls_rbuf} .= $tmp;
330 or return; 1907 $self->_drain_rbuf;
331 1908 $self->{tls} or return; # tls session might have gone away in callback
332 unless (defined $wba->[0]) {
333 $wba->[1]->($self) if $wba->[1];
334 $self->_check_writer;
335 return;
336 } 1909 }
337 1910
338 $self->{wbuf} = $wba->[0]; 1911 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
339 $self->{write_cb} = $wba->[1]; 1912 return $self->_tls_error ($tmp)
1913 if $tmp != $ERROR_WANT_READ
1914 && ($tmp != $ERROR_SYSCALL || $!);
340 1915
341 $self->{write_w} = 1916 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
342 AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub { 1917 $self->{wbuf} .= $tmp;
343 my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf}; 1918 $self->_drain_wbuf;
1919 $self->{tls} or return; # tls session might have gone away in callback
1920 }
344 1921
345 if (not defined $l) { 1922 $self->{_on_starttls}
346 return if $! == EAGAIN || $! == EINTR; 1923 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
347 delete $self->{write_w}; 1924 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
348 $self->{on_error}->($self) if $self->{on_error}; 1925}
349 1926
1927=item $handle->starttls ($tls[, $tls_ctx])
1928
1929Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1930object is created, you can also do that at a later time by calling
1931C<starttls>.
1932
1933Starting TLS is currently an asynchronous operation - when you push some
1934write data and then call C<< ->starttls >> then TLS negotiation will start
1935immediately, after which the queued write data is then sent.
1936
1937The first argument is the same as the C<tls> constructor argument (either
1938C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1939
1940The second argument is the optional C<AnyEvent::TLS> object that is used
1941when AnyEvent::Handle has to create its own TLS connection object, or
1942a hash reference with C<< key => value >> pairs that will be used to
1943construct a new context.
1944
1945The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1946context in C<< $handle->{tls_ctx} >> after this call and can be used or
1947changed to your liking. Note that the handshake might have already started
1948when this function returns.
1949
1950Due to bugs in OpenSSL, it might or might not be possible to do multiple
1951handshakes on the same stream. It is best to not attempt to use the
1952stream after stopping TLS.
1953
1954This method may invoke callbacks (and therefore the handle might be
1955destroyed after it returns).
1956
1957=cut
1958
1959our %TLS_CACHE; #TODO not yet documented, should we?
1960
1961sub starttls {
1962 my ($self, $tls, $ctx) = @_;
1963
1964 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1965 if $self->{tls};
1966
1967 $self->{tls} = $tls;
1968 $self->{tls_ctx} = $ctx if @_ > 2;
1969
1970 return unless $self->{fh};
1971
1972 require Net::SSLeay;
1973
1974 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1975 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1976
1977 $tls = delete $self->{tls};
1978 $ctx = $self->{tls_ctx};
1979
1980 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1981
1982 if ("HASH" eq ref $ctx) {
1983 require AnyEvent::TLS;
1984
1985 if ($ctx->{cache}) {
1986 my $key = $ctx+0;
1987 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
350 } else { 1988 } else {
1989 $ctx = new AnyEvent::TLS %$ctx;
1990 }
1991 }
1992
1993 $self->{tls_ctx} = $ctx || TLS_CTX ();
1994 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1995
1996 # basically, this is deep magic (because SSL_read should have the same issues)
1997 # but the openssl maintainers basically said: "trust us, it just works".
1998 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1999 # and mismaintained ssleay-module doesn't even offer them).
2000 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
2001 #
2002 # in short: this is a mess.
2003 #
2004 # note that we do not try to keep the length constant between writes as we are required to do.
2005 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
2006 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
2007 # have identity issues in that area.
2008# Net::SSLeay::CTX_set_mode ($ssl,
2009# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
2010# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
2011 Net::SSLeay::CTX_set_mode ($tls, 1|2);
2012
2013 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
2014 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
2015
2016 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2017 $self->{rbuf} = "";
2018
2019 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
2020
2021 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
2022 if $self->{on_starttls};
2023
2024 &_dotls; # need to trigger the initial handshake
2025 $self->start_read; # make sure we actually do read
2026}
2027
2028=item $handle->stoptls
2029
2030Shuts down the SSL connection - this makes a proper EOF handshake by
2031sending a close notify to the other side, but since OpenSSL doesn't
2032support non-blocking shut downs, it is not guaranteed that you can re-use
2033the stream afterwards.
2034
2035This method may invoke callbacks (and therefore the handle might be
2036destroyed after it returns).
2037
2038=cut
2039
2040sub stoptls {
2041 my ($self) = @_;
2042
2043 if ($self->{tls} && $self->{fh}) {
2044 Net::SSLeay::shutdown ($self->{tls});
2045
2046 &_dotls;
2047
2048# # we don't give a shit. no, we do, but we can't. no...#d#
2049# # we, we... have to use openssl :/#d#
2050# &_freetls;#d#
2051 }
2052}
2053
2054sub _freetls {
2055 my ($self) = @_;
2056
2057 return unless $self->{tls};
2058
2059 $self->{tls_ctx}->_put_session (delete $self->{tls})
2060 if $self->{tls} > 0;
2061
2062 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
2063}
2064
2065=item $handle->resettls
2066
2067This rarely-used method simply resets and TLS state on the handle, usually
2068causing data loss.
2069
2070One case where it may be useful is when you want to skip over the data in
2071the stream but you are not interested in interpreting it, so data loss is
2072no concern.
2073
2074=cut
2075
2076*resettls = \&_freetls;
2077
2078sub DESTROY {
2079 my ($self) = @_;
2080
2081 &_freetls;
2082
2083 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
2084
2085 if ($linger && length $self->{wbuf} && $self->{fh}) {
2086 my $fh = delete $self->{fh};
2087 my $wbuf = delete $self->{wbuf};
2088
2089 my @linger;
2090
2091 push @linger, AE::io $fh, 1, sub {
2092 my $len = syswrite $fh, $wbuf, length $wbuf;
2093
2094 if ($len > 0) {
351 substr $self->{wbuf}, 0, $l, ''; 2095 substr $wbuf, 0, $len, "";
352 2096 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
353 if (length ($self->{wbuf}) == 0) { 2097 @linger = (); # end
354 $self->{write_cb}->($self) if $self->{write_cb};
355
356 delete $self->{write_w};
357 delete $self->{wbuf};
358 delete $self->{write_cb};
359
360 $self->_check_writer;
361 }
362 } 2098 }
2099 };
2100 push @linger, AE::timer $linger, 0, sub {
2101 @linger = ();
2102 };
2103 }
2104}
2105
2106=item $handle->destroy
2107
2108Shuts down the handle object as much as possible - this call ensures that
2109no further callbacks will be invoked and as many resources as possible
2110will be freed. Any method you will call on the handle object after
2111destroying it in this way will be silently ignored (and it will return the
2112empty list).
2113
2114Normally, you can just "forget" any references to an AnyEvent::Handle
2115object and it will simply shut down. This works in fatal error and EOF
2116callbacks, as well as code outside. It does I<NOT> work in a read or write
2117callback, so when you want to destroy the AnyEvent::Handle object from
2118within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
2119that case.
2120
2121Destroying the handle object in this way has the advantage that callbacks
2122will be removed as well, so if those are the only reference holders (as
2123is common), then one doesn't need to do anything special to break any
2124reference cycles.
2125
2126The handle might still linger in the background and write out remaining
2127data, as specified by the C<linger> option, however.
2128
2129=cut
2130
2131sub destroy {
2132 my ($self) = @_;
2133
2134 $self->DESTROY;
2135 %$self = ();
2136 bless $self, "AnyEvent::Handle::destroyed";
2137}
2138
2139sub AnyEvent::Handle::destroyed::AUTOLOAD {
2140 #nop
2141}
2142
2143=item $handle->destroyed
2144
2145Returns false as long as the handle hasn't been destroyed by a call to C<<
2146->destroy >>, true otherwise.
2147
2148Can be useful to decide whether the handle is still valid after some
2149callback possibly destroyed the handle. For example, C<< ->push_write >>,
2150C<< ->starttls >> and other methods can call user callbacks, which in turn
2151can destroy the handle, so work can be avoided by checking sometimes:
2152
2153 $hdl->starttls ("accept");
2154 return if $hdl->destroyed;
2155 $hdl->push_write (...
2156
2157Note that the call to C<push_write> will silently be ignored if the handle
2158has been destroyed, so often you can just ignore the possibility of the
2159handle being destroyed.
2160
2161=cut
2162
2163sub destroyed { 0 }
2164sub AnyEvent::Handle::destroyed::destroyed { 1 }
2165
2166=item AnyEvent::Handle::TLS_CTX
2167
2168This function creates and returns the AnyEvent::TLS object used by default
2169for TLS mode.
2170
2171The context is created by calling L<AnyEvent::TLS> without any arguments.
2172
2173=cut
2174
2175our $TLS_CTX;
2176
2177sub TLS_CTX() {
2178 $TLS_CTX ||= do {
2179 require AnyEvent::TLS;
2180
2181 new AnyEvent::TLS
2182 }
2183}
2184
2185=back
2186
2187
2188=head1 NONFREQUENTLY ASKED QUESTIONS
2189
2190=over 4
2191
2192=item I C<undef> the AnyEvent::Handle reference inside my callback and
2193still get further invocations!
2194
2195That's because AnyEvent::Handle keeps a reference to itself when handling
2196read or write callbacks.
2197
2198It is only safe to "forget" the reference inside EOF or error callbacks,
2199from within all other callbacks, you need to explicitly call the C<<
2200->destroy >> method.
2201
2202=item Why is my C<on_eof> callback never called?
2203
2204Probably because your C<on_error> callback is being called instead: When
2205you have outstanding requests in your read queue, then an EOF is
2206considered an error as you clearly expected some data.
2207
2208To avoid this, make sure you have an empty read queue whenever your handle
2209is supposed to be "idle" (i.e. connection closes are O.K.). You can set
2210an C<on_read> handler that simply pushes the first read requests in the
2211queue.
2212
2213See also the next question, which explains this in a bit more detail.
2214
2215=item How can I serve requests in a loop?
2216
2217Most protocols consist of some setup phase (authentication for example)
2218followed by a request handling phase, where the server waits for requests
2219and handles them, in a loop.
2220
2221There are two important variants: The first (traditional, better) variant
2222handles requests until the server gets some QUIT command, causing it to
2223close the connection first (highly desirable for a busy TCP server). A
2224client dropping the connection is an error, which means this variant can
2225detect an unexpected detection close.
2226
2227To handle this case, always make sure you have a on-empty read queue, by
2228pushing the "read request start" handler on it:
2229
2230 # we assume a request starts with a single line
2231 my @start_request; @start_request = (line => sub {
2232 my ($hdl, $line) = @_;
2233
2234 ... handle request
2235
2236 # push next request read, possibly from a nested callback
2237 $hdl->push_read (@start_request);
2238 });
2239
2240 # auth done, now go into request handling loop
2241 # now push the first @start_request
2242 $hdl->push_read (@start_request);
2243
2244By always having an outstanding C<push_read>, the handle always expects
2245some data and raises the C<EPIPE> error when the connction is dropped
2246unexpectedly.
2247
2248The second variant is a protocol where the client can drop the connection
2249at any time. For TCP, this means that the server machine may run out of
2250sockets easier, and in general, it means you cannot distinguish a protocl
2251failure/client crash from a normal connection close. Nevertheless, these
2252kinds of protocols are common (and sometimes even the best solution to the
2253problem).
2254
2255Having an outstanding read request at all times is possible if you ignore
2256C<EPIPE> errors, but this doesn't help with when the client drops the
2257connection during a request, which would still be an error.
2258
2259A better solution is to push the initial request read in an C<on_read>
2260callback. This avoids an error, as when the server doesn't expect data
2261(i.e. is idly waiting for the next request, an EOF will not raise an
2262error, but simply result in an C<on_eof> callback. It is also a bit slower
2263and simpler:
2264
2265 # auth done, now go into request handling loop
2266 $hdl->on_read (sub {
2267 my ($hdl) = @_;
2268
2269 # called each time we receive data but the read queue is empty
2270 # simply start read the request
2271
2272 $hdl->push_read (line => sub {
2273 my ($hdl, $line) = @_;
2274
2275 ... handle request
2276
2277 # do nothing special when the request has been handled, just
2278 # let the request queue go empty.
363 }); 2279 });
364} 2280 });
2281
2282=item I get different callback invocations in TLS mode/Why can't I pause
2283reading?
2284
2285Unlike, say, TCP, TLS connections do not consist of two independent
2286communication channels, one for each direction. Or put differently, the
2287read and write directions are not independent of each other: you cannot
2288write data unless you are also prepared to read, and vice versa.
2289
2290This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2291callback invocations when you are not expecting any read data - the reason
2292is that AnyEvent::Handle always reads in TLS mode.
2293
2294During the connection, you have to make sure that you always have a
2295non-empty read-queue, or an C<on_read> watcher. At the end of the
2296connection (or when you no longer want to use it) you can call the
2297C<destroy> method.
2298
2299=item How do I read data until the other side closes the connection?
2300
2301If you just want to read your data into a perl scalar, the easiest way
2302to achieve this is by setting an C<on_read> callback that does nothing,
2303clearing the C<on_eof> callback and in the C<on_error> callback, the data
2304will be in C<$_[0]{rbuf}>:
2305
2306 $handle->on_read (sub { });
2307 $handle->on_eof (undef);
2308 $handle->on_error (sub {
2309 my $data = delete $_[0]{rbuf};
2310 });
2311
2312Note that this example removes the C<rbuf> member from the handle object,
2313which is not normally allowed by the API. It is expressly permitted in
2314this case only, as the handle object needs to be destroyed afterwards.
2315
2316The reason to use C<on_error> is that TCP connections, due to latencies
2317and packets loss, might get closed quite violently with an error, when in
2318fact all data has been received.
2319
2320It is usually better to use acknowledgements when transferring data,
2321to make sure the other side hasn't just died and you got the data
2322intact. This is also one reason why so many internet protocols have an
2323explicit QUIT command.
2324
2325=item I don't want to destroy the handle too early - how do I wait until
2326all data has been written?
2327
2328After writing your last bits of data, set the C<on_drain> callback
2329and destroy the handle in there - with the default setting of
2330C<low_water_mark> this will be called precisely when all data has been
2331written to the socket:
2332
2333 $handle->push_write (...);
2334 $handle->on_drain (sub {
2335 AE::log debug => "all data submitted to the kernel\n";
2336 undef $handle;
2337 });
2338
2339If you just want to queue some data and then signal EOF to the other side,
2340consider using C<< ->push_shutdown >> instead.
2341
2342=item I want to contact a TLS/SSL server, I don't care about security.
2343
2344If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2345connect to it and then create the AnyEvent::Handle with the C<tls>
2346parameter:
2347
2348 tcp_connect $host, $port, sub {
2349 my ($fh) = @_;
2350
2351 my $handle = new AnyEvent::Handle
2352 fh => $fh,
2353 tls => "connect",
2354 on_error => sub { ... };
2355
2356 $handle->push_write (...);
2357 };
2358
2359=item I want to contact a TLS/SSL server, I do care about security.
2360
2361Then you should additionally enable certificate verification, including
2362peername verification, if the protocol you use supports it (see
2363L<AnyEvent::TLS>, C<verify_peername>).
2364
2365E.g. for HTTPS:
2366
2367 tcp_connect $host, $port, sub {
2368 my ($fh) = @_;
2369
2370 my $handle = new AnyEvent::Handle
2371 fh => $fh,
2372 peername => $host,
2373 tls => "connect",
2374 tls_ctx => { verify => 1, verify_peername => "https" },
2375 ...
2376
2377Note that you must specify the hostname you connected to (or whatever
2378"peername" the protocol needs) as the C<peername> argument, otherwise no
2379peername verification will be done.
2380
2381The above will use the system-dependent default set of trusted CA
2382certificates. If you want to check against a specific CA, add the
2383C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
2384
2385 tls_ctx => {
2386 verify => 1,
2387 verify_peername => "https",
2388 ca_file => "my-ca-cert.pem",
2389 },
2390
2391=item I want to create a TLS/SSL server, how do I do that?
2392
2393Well, you first need to get a server certificate and key. You have
2394three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
2395self-signed certificate (cheap. check the search engine of your choice,
2396there are many tutorials on the net) or c) make your own CA (tinyca2 is a
2397nice program for that purpose).
2398
2399Then create a file with your private key (in PEM format, see
2400L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
2401file should then look like this:
2402
2403 -----BEGIN RSA PRIVATE KEY-----
2404 ...header data
2405 ... lots of base64'y-stuff
2406 -----END RSA PRIVATE KEY-----
2407
2408 -----BEGIN CERTIFICATE-----
2409 ... lots of base64'y-stuff
2410 -----END CERTIFICATE-----
2411
2412The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2413specify this file as C<cert_file>:
2414
2415 tcp_server undef, $port, sub {
2416 my ($fh) = @_;
2417
2418 my $handle = new AnyEvent::Handle
2419 fh => $fh,
2420 tls => "accept",
2421 tls_ctx => { cert_file => "my-server-keycert.pem" },
2422 ...
2423
2424When you have intermediate CA certificates that your clients might not
2425know about, just append them to the C<cert_file>.
365 2426
366=back 2427=back
367 2428
2429
2430=head1 SUBCLASSING AnyEvent::Handle
2431
2432In many cases, you might want to subclass AnyEvent::Handle.
2433
2434To make this easier, a given version of AnyEvent::Handle uses these
2435conventions:
2436
2437=over 4
2438
2439=item * all constructor arguments become object members.
2440
2441At least initially, when you pass a C<tls>-argument to the constructor it
2442will end up in C<< $handle->{tls} >>. Those members might be changed or
2443mutated later on (for example C<tls> will hold the TLS connection object).
2444
2445=item * other object member names are prefixed with an C<_>.
2446
2447All object members not explicitly documented (internal use) are prefixed
2448with an underscore character, so the remaining non-C<_>-namespace is free
2449for use for subclasses.
2450
2451=item * all members not documented here and not prefixed with an underscore
2452are free to use in subclasses.
2453
2454Of course, new versions of AnyEvent::Handle may introduce more "public"
2455member variables, but that's just life. At least it is documented.
2456
2457=back
2458
368=head1 AUTHOR 2459=head1 AUTHOR
369 2460
370Robin Redeker, C<< <elmex at ta-sa.org> >> 2461Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
371 2462
372=cut 2463=cut
373 2464
3741; # End of AnyEvent::Handle 24651; # End of AnyEvent::Handle

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