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Revision 1.9 by root, Fri May 2 16:07:46 2008 UTC vs.
Revision 1.164 by root, Mon Jul 27 22:44:43 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings;
4use strict;
5
6use AnyEvent ();
7use AnyEvent::Util ();
8use Scalar::Util (); 3use Scalar::Util ();
9use Carp (); 4use Carp ();
10use Fcntl ();
11use Errno qw/EAGAIN EINTR/; 5use Errno qw(EAGAIN EINTR);
6
7use AnyEvent (); BEGIN { AnyEvent::common_sense }
8use AnyEvent::Util qw(WSAEWOULDBLOCK);
12 9
13=head1 NAME 10=head1 NAME
14 11
15AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent 12AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 13
17=cut 14=cut
18 15
19our $VERSION = '0.02'; 16our $VERSION = 4.87;
20 17
21=head1 SYNOPSIS 18=head1 SYNOPSIS
22 19
23 use AnyEvent; 20 use AnyEvent;
24 use AnyEvent::Handle; 21 use AnyEvent::Handle;
25 22
26 my $cv = AnyEvent->condvar; 23 my $cv = AnyEvent->condvar;
27 24
28 my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN); 25 my $hdl; $hdl = new AnyEvent::Handle
29
30 #TODO
31
32 # or use the constructor to pass the callback:
33
34 my $ae_fh2 =
35 AnyEvent::Handle->new (
36 fh => \*STDIN, 26 fh => \*STDIN,
37 on_eof => sub { 27 on_error => sub {
38 $cv->broadcast; 28 my ($hdl, $fatal, $msg) = @_;
39 }, 29 warn "got error $msg\n";
40 #TODO 30 $hdl->destroy;
31 $cv->send;
41 ); 32 );
42 33
43 $cv->wait; 34 # send some request line
35 $hdl->push_write ("getinfo\015\012");
36
37 # read the response line
38 $hdl->push_read (line => sub {
39 my ($hdl, $line) = @_;
40 warn "got line <$line>\n";
41 $cv->send;
42 });
43
44 $cv->recv;
44 45
45=head1 DESCRIPTION 46=head1 DESCRIPTION
46 47
47This module is a helper module to make it easier to do event-based I/O on 48This module is a helper module to make it easier to do event-based I/O on
48filehandles (and sockets, see L<AnyEvent::Socket> for an easy way to make 49filehandles.
49non-blocking resolves and connects). 50
51The L<AnyEvent::Intro> tutorial contains some well-documented
52AnyEvent::Handle examples.
50 53
51In the following, when the documentation refers to of "bytes" then this 54In the following, when the documentation refers to of "bytes" then this
52means characters. As sysread and syswrite are used for all I/O, their 55means characters. As sysread and syswrite are used for all I/O, their
53treatment of characters applies to this module as well. 56treatment of characters applies to this module as well.
54 57
58At the very minimum, you should specify C<fh> or C<connect>, and the
59C<on_error> callback.
60
55All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
56argument. 62argument.
57 63
58=head1 METHODS 64=head1 METHODS
59 65
60=over 4 66=over 4
61 67
62=item B<new (%args)> 68=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
63 69
64The constructor supports these arguments (all as key => value pairs). 70The constructor supports these arguments (all as C<< key => value >> pairs).
65 71
66=over 4 72=over 4
67 73
68=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
69 75
70The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
71
72NOTE: The filehandle will be set to non-blocking (using 77NOTE: The filehandle will be set to non-blocking mode (using
73AnyEvent::Util::fh_nonblocking). 78C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
79that mode.
74 80
75=item on_error => $cb->($self) [MANDATORY] 81=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
76 82
77This is the fatal error callback, that is called when a fatal error ocurs, 83Try to connect to the specified host and service (port), using
84C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
85default C<peername>.
86
87You have to specify either this parameter, or C<fh>, above.
88
89It is possible to push requests on the read and write queues, and modify
90properties of the stream, even while AnyEvent::Handle is connecting.
91
92When this parameter is specified, then the C<on_prepare>,
93C<on_connect_error> and C<on_connect> callbacks will be called under the
94appropriate circumstances:
95
96=over 4
97
98=item on_prepare => $cb->($handle)
99
100This (rarely used) callback is called before a new connection is
101attempted, but after the file handle has been created. It could be used to
102prepare the file handle with parameters required for the actual connect
103(as opposed to settings that can be changed when the connection is already
104established).
105
106The return value of this callback should be the connect timeout value in
107seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
108timeout is to be used).
109
110=item on_connect => $cb->($handle, $host, $port, $retry->())
111
112This callback is called when a connection has been successfully established.
113
114The actual numeric host and port (the socket peername) are passed as
115parameters, together with a retry callback.
116
117When, for some reason, the handle is not acceptable, then calling
118C<$retry> will continue with the next conenction target (in case of
119multi-homed hosts or SRV records there can be multiple connection
120endpoints). When it is called then the read and write queues, eof status,
121tls status and similar properties of the handle are being reset.
122
123In most cases, ignoring the C<$retry> parameter is the way to go.
124
125=item on_connect_error => $cb->($handle, $message)
126
127This callback is called when the conenction could not be
128established. C<$!> will contain the relevant error code, and C<$message> a
129message describing it (usually the same as C<"$!">).
130
131If this callback isn't specified, then C<on_error> will be called with a
132fatal error instead.
133
134=back
135
136=item on_error => $cb->($handle, $fatal, $message)
137
138This is the error callback, which is called when, well, some error
78such as not being able to resolve the hostname, failure to connect or a 139occured, such as not being able to resolve the hostname, failure to
79read error. 140connect or a read error.
80 141
81The object will not be in a usable state when this callback has been 142Some errors are fatal (which is indicated by C<$fatal> being true). On
82called. 143fatal errors the handle object will be destroyed (by a call to C<< ->
144destroy >>) after invoking the error callback (which means you are free to
145examine the handle object). Examples of fatal errors are an EOF condition
146with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
147cases where the other side can close the connection at their will it is
148often easiest to not report C<EPIPE> errors in this callback.
83 149
150AnyEvent::Handle tries to find an appropriate error code for you to check
151against, but in some cases (TLS errors), this does not work well. It is
152recommended to always output the C<$message> argument in human-readable
153error messages (it's usually the same as C<"$!">).
154
155Non-fatal errors can be retried by simply returning, but it is recommended
156to simply ignore this parameter and instead abondon the handle object
157when this callback is invoked. Examples of non-fatal errors are timeouts
158C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
159
84On callback entrance, the value of C<$!> contains the opertaing system 160On callback entrance, the value of C<$!> contains the operating system
85error (or C<ENOSPC> or C<EPIPE>). 161error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
162C<EPROTO>).
86 163
87=item on_eof => $cb->($self) [MANDATORY] 164While not mandatory, it is I<highly> recommended to set this callback, as
165you will not be notified of errors otherwise. The default simply calls
166C<croak>.
88 167
89Set the callback to be called on EOF.
90
91=item on_read => $cb->($self) 168=item on_read => $cb->($handle)
92 169
93This sets the default read callback, which is called when data arrives 170This sets the default read callback, which is called when data arrives
94and no read request is in the queue. If the read callback is C<undef> 171and no read request is in the queue (unlike read queue callbacks, this
95or has never been set, than AnyEvent::Handle will cease reading from the 172callback will only be called when at least one octet of data is in the
96filehandle. 173read buffer).
97 174
98To access (and remove data from) the read buffer, use the C<< ->rbuf >> 175To access (and remove data from) the read buffer, use the C<< ->rbuf >>
99method or acces sthe C<$self->{rbuf}> member directly. 176method or access the C<< $handle->{rbuf} >> member directly. Note that you
177must not enlarge or modify the read buffer, you can only remove data at
178the beginning from it.
100 179
101When an EOF condition is detected then AnyEvent::Handle will first try to 180When an EOF condition is detected then AnyEvent::Handle will first try to
102feed all the remaining data to the queued callbacks and C<on_read> before 181feed all the remaining data to the queued callbacks and C<on_read> before
103calling the C<on_eof> callback. If no progress can be made, then a fatal 182calling the C<on_eof> callback. If no progress can be made, then a fatal
104error will be raised (with C<$!> set to C<EPIPE>). 183error will be raised (with C<$!> set to C<EPIPE>).
105 184
185Note that, unlike requests in the read queue, an C<on_read> callback
186doesn't mean you I<require> some data: if there is an EOF and there
187are outstanding read requests then an error will be flagged. With an
188C<on_read> callback, the C<on_eof> callback will be invoked.
189
190=item on_eof => $cb->($handle)
191
192Set the callback to be called when an end-of-file condition is detected,
193i.e. in the case of a socket, when the other side has closed the
194connection cleanly, and there are no outstanding read requests in the
195queue (if there are read requests, then an EOF counts as an unexpected
196connection close and will be flagged as an error).
197
198For sockets, this just means that the other side has stopped sending data,
199you can still try to write data, and, in fact, one can return from the EOF
200callback and continue writing data, as only the read part has been shut
201down.
202
203If an EOF condition has been detected but no C<on_eof> callback has been
204set, then a fatal error will be raised with C<$!> set to <0>.
205
106=item on_drain => $cb->() 206=item on_drain => $cb->($handle)
107 207
108This sets the callback that is called when the write buffer becomes empty 208This sets the callback that is called when the write buffer becomes empty
109(or when the callback is set and the buffer is empty already). 209(or when the callback is set and the buffer is empty already).
110 210
111To append to the write buffer, use the C<< ->push_write >> method. 211To append to the write buffer, use the C<< ->push_write >> method.
112 212
213This callback is useful when you don't want to put all of your write data
214into the queue at once, for example, when you want to write the contents
215of some file to the socket you might not want to read the whole file into
216memory and push it into the queue, but instead only read more data from
217the file when the write queue becomes empty.
218
219=item timeout => $fractional_seconds
220
221If non-zero, then this enables an "inactivity" timeout: whenever this many
222seconds pass without a successful read or write on the underlying file
223handle, the C<on_timeout> callback will be invoked (and if that one is
224missing, a non-fatal C<ETIMEDOUT> error will be raised).
225
226Note that timeout processing is also active when you currently do not have
227any outstanding read or write requests: If you plan to keep the connection
228idle then you should disable the timout temporarily or ignore the timeout
229in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
230restart the timeout.
231
232Zero (the default) disables this timeout.
233
234=item on_timeout => $cb->($handle)
235
236Called whenever the inactivity timeout passes. If you return from this
237callback, then the timeout will be reset as if some activity had happened,
238so this condition is not fatal in any way.
239
113=item rbuf_max => <bytes> 240=item rbuf_max => <bytes>
114 241
115If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 242If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
116when the read buffer ever (strictly) exceeds this size. This is useful to 243when the read buffer ever (strictly) exceeds this size. This is useful to
117avoid denial-of-service attacks. 244avoid some forms of denial-of-service attacks.
118 245
119For example, a server accepting connections from untrusted sources should 246For example, a server accepting connections from untrusted sources should
120be configured to accept only so-and-so much data that it cannot act on 247be configured to accept only so-and-so much data that it cannot act on
121(for example, when expecting a line, an attacker could send an unlimited 248(for example, when expecting a line, an attacker could send an unlimited
122amount of data without a callback ever being called as long as the line 249amount of data without a callback ever being called as long as the line
123isn't finished). 250isn't finished).
124 251
252=item autocork => <boolean>
253
254When disabled (the default), then C<push_write> will try to immediately
255write the data to the handle, if possible. This avoids having to register
256a write watcher and wait for the next event loop iteration, but can
257be inefficient if you write multiple small chunks (on the wire, this
258disadvantage is usually avoided by your kernel's nagle algorithm, see
259C<no_delay>, but this option can save costly syscalls).
260
261When enabled, then writes will always be queued till the next event loop
262iteration. This is efficient when you do many small writes per iteration,
263but less efficient when you do a single write only per iteration (or when
264the write buffer often is full). It also increases write latency.
265
266=item no_delay => <boolean>
267
268When doing small writes on sockets, your operating system kernel might
269wait a bit for more data before actually sending it out. This is called
270the Nagle algorithm, and usually it is beneficial.
271
272In some situations you want as low a delay as possible, which can be
273accomplishd by setting this option to a true value.
274
275The default is your opertaing system's default behaviour (most likely
276enabled), this option explicitly enables or disables it, if possible.
277
125=item read_size => <bytes> 278=item read_size => <bytes>
126 279
127The default read block size (the amount of bytes this module will try to read 280The default read block size (the amount of bytes this module will
128on each [loop iteration). Default: C<4096>. 281try to read during each loop iteration, which affects memory
282requirements). Default: C<8192>.
129 283
130=item low_water_mark => <bytes> 284=item low_water_mark => <bytes>
131 285
132Sets the amount of bytes (default: C<0>) that make up an "empty" write 286Sets the amount of bytes (default: C<0>) that make up an "empty" write
133buffer: If the write reaches this size or gets even samller it is 287buffer: If the write reaches this size or gets even samller it is
134considered empty. 288considered empty.
135 289
290Sometimes it can be beneficial (for performance reasons) to add data to
291the write buffer before it is fully drained, but this is a rare case, as
292the operating system kernel usually buffers data as well, so the default
293is good in almost all cases.
294
295=item linger => <seconds>
296
297If non-zero (default: C<3600>), then the destructor of the
298AnyEvent::Handle object will check whether there is still outstanding
299write data and will install a watcher that will write this data to the
300socket. No errors will be reported (this mostly matches how the operating
301system treats outstanding data at socket close time).
302
303This will not work for partial TLS data that could not be encoded
304yet. This data will be lost. Calling the C<stoptls> method in time might
305help.
306
307=item peername => $string
308
309A string used to identify the remote site - usually the DNS hostname
310(I<not> IDN!) used to create the connection, rarely the IP address.
311
312Apart from being useful in error messages, this string is also used in TLS
313peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
314verification will be skipped when C<peername> is not specified or
315C<undef>.
316
317=item tls => "accept" | "connect" | Net::SSLeay::SSL object
318
319When this parameter is given, it enables TLS (SSL) mode, that means
320AnyEvent will start a TLS handshake as soon as the conenction has been
321established and will transparently encrypt/decrypt data afterwards.
322
323All TLS protocol errors will be signalled as C<EPROTO>, with an
324appropriate error message.
325
326TLS mode requires Net::SSLeay to be installed (it will be loaded
327automatically when you try to create a TLS handle): this module doesn't
328have a dependency on that module, so if your module requires it, you have
329to add the dependency yourself.
330
331Unlike TCP, TLS has a server and client side: for the TLS server side, use
332C<accept>, and for the TLS client side of a connection, use C<connect>
333mode.
334
335You can also provide your own TLS connection object, but you have
336to make sure that you call either C<Net::SSLeay::set_connect_state>
337or C<Net::SSLeay::set_accept_state> on it before you pass it to
338AnyEvent::Handle. Also, this module will take ownership of this connection
339object.
340
341At some future point, AnyEvent::Handle might switch to another TLS
342implementation, then the option to use your own session object will go
343away.
344
345B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
346passing in the wrong integer will lead to certain crash. This most often
347happens when one uses a stylish C<< tls => 1 >> and is surprised about the
348segmentation fault.
349
350See the C<< ->starttls >> method for when need to start TLS negotiation later.
351
352=item tls_ctx => $anyevent_tls
353
354Use the given C<AnyEvent::TLS> object to create the new TLS connection
355(unless a connection object was specified directly). If this parameter is
356missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
357
358Instead of an object, you can also specify a hash reference with C<< key
359=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
360new TLS context object.
361
362=item on_starttls => $cb->($handle, $success[, $error_message])
363
364This callback will be invoked when the TLS/SSL handshake has finished. If
365C<$success> is true, then the TLS handshake succeeded, otherwise it failed
366(C<on_stoptls> will not be called in this case).
367
368The session in C<< $handle->{tls} >> can still be examined in this
369callback, even when the handshake was not successful.
370
371TLS handshake failures will not cause C<on_error> to be invoked when this
372callback is in effect, instead, the error message will be passed to C<on_starttls>.
373
374Without this callback, handshake failures lead to C<on_error> being
375called, as normal.
376
377Note that you cannot call C<starttls> right again in this callback. If you
378need to do that, start an zero-second timer instead whose callback can
379then call C<< ->starttls >> again.
380
381=item on_stoptls => $cb->($handle)
382
383When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
384set, then it will be invoked after freeing the TLS session. If it is not,
385then a TLS shutdown condition will be treated like a normal EOF condition
386on the handle.
387
388The session in C<< $handle->{tls} >> can still be examined in this
389callback.
390
391This callback will only be called on TLS shutdowns, not when the
392underlying handle signals EOF.
393
394=item json => JSON or JSON::XS object
395
396This is the json coder object used by the C<json> read and write types.
397
398If you don't supply it, then AnyEvent::Handle will create and use a
399suitable one (on demand), which will write and expect UTF-8 encoded JSON
400texts.
401
402Note that you are responsible to depend on the JSON module if you want to
403use this functionality, as AnyEvent does not have a dependency itself.
404
136=back 405=back
137 406
138=cut 407=cut
139 408
140sub new { 409sub new {
141 my $class = shift; 410 my $class = shift;
142
143 my $self = bless { @_ }, $class; 411 my $self = bless { @_ }, $class;
144 412
145 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 413 if ($self->{fh}) {
414 $self->_start;
415 return unless $self->{fh}; # could be gone by now
416
417 } elsif ($self->{connect}) {
418 require AnyEvent::Socket;
419
420 $self->{peername} = $self->{connect}[0]
421 unless exists $self->{peername};
422
423 $self->{_skip_drain_rbuf} = 1;
424
425 {
426 Scalar::Util::weaken (my $self = $self);
427
428 $self->{_connect} =
429 AnyEvent::Socket::tcp_connect (
430 $self->{connect}[0],
431 $self->{connect}[1],
432 sub {
433 my ($fh, $host, $port, $retry) = @_;
434
435 if ($fh) {
436 $self->{fh} = $fh;
437
438 delete $self->{_skip_drain_rbuf};
439 $self->_start;
440
441 $self->{on_connect}
442 and $self->{on_connect}($self, $host, $port, sub {
443 delete @$self{qw(fh _tw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
444 $self->{_skip_drain_rbuf} = 1;
445 &$retry;
446 });
447
448 } else {
449 if ($self->{on_connect_error}) {
450 $self->{on_connect_error}($self, "$!");
451 $self->destroy;
452 } else {
453 $self->_error ($!, 1);
454 }
455 }
456 },
457 sub {
458 local $self->{fh} = $_[0];
459
460 $self->{on_prepare}
461 ? $self->{on_prepare}->($self)
462 : ()
463 }
464 );
465 }
466
467 } else {
468 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
469 }
470
471 $self
472}
473
474sub _start {
475 my ($self) = @_;
146 476
147 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 477 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
148 478
149 $self->on_error ((delete $self->{on_error}) or Carp::croak "mandatory argument on_error is missing"); 479 $self->{_activity} = AnyEvent->now;
150 $self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing"); 480 $self->_timeout;
481
482 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
483
484 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
485 if $self->{tls};
151 486
152 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 487 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
153 $self->on_read (delete $self->{on_read} ) if $self->{on_read};
154 488
155 $self 489 $self->start_read
156} 490 if $self->{on_read} || @{ $self->{_queue} };
157 491
492 $self->_drain_wbuf;
493}
494
158sub _shutdown { 495#sub _shutdown {
159 my ($self) = @_; 496# my ($self) = @_;
497#
498# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
499# $self->{_eof} = 1; # tell starttls et. al to stop trying
500#
501# &_freetls;
502#}
160 503
161 delete $self->{rw};
162 delete $self->{ww};
163 delete $self->{fh};
164}
165
166sub error { 504sub _error {
167 my ($self) = @_; 505 my ($self, $errno, $fatal, $message) = @_;
168 506
169 { 507 $! = $errno;
170 local $!; 508 $message ||= "$!";
509
510 if ($self->{on_error}) {
511 $self->{on_error}($self, $fatal, $message);
512 $self->destroy if $fatal;
513 } elsif ($self->{fh}) {
171 $self->_shutdown; 514 $self->destroy;
515 Carp::croak "AnyEvent::Handle uncaught error: $message";
172 } 516 }
173
174 $self->{on_error}($self);
175} 517}
176 518
177=item $fh = $handle->fh 519=item $fh = $handle->fh
178 520
179This method returns the filehandle of the L<AnyEvent::Handle> object. 521This method returns the file handle used to create the L<AnyEvent::Handle> object.
180 522
181=cut 523=cut
182 524
183sub fh { $_[0]->{fh} } 525sub fh { $_[0]{fh} }
184 526
185=item $handle->on_error ($cb) 527=item $handle->on_error ($cb)
186 528
187Replace the current C<on_error> callback (see the C<on_error> constructor argument). 529Replace the current C<on_error> callback (see the C<on_error> constructor argument).
188 530
200 542
201sub on_eof { 543sub on_eof {
202 $_[0]{on_eof} = $_[1]; 544 $_[0]{on_eof} = $_[1];
203} 545}
204 546
547=item $handle->on_timeout ($cb)
548
549Replace the current C<on_timeout> callback, or disables the callback (but
550not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
551argument and method.
552
553=cut
554
555sub on_timeout {
556 $_[0]{on_timeout} = $_[1];
557}
558
559=item $handle->autocork ($boolean)
560
561Enables or disables the current autocork behaviour (see C<autocork>
562constructor argument). Changes will only take effect on the next write.
563
564=cut
565
566sub autocork {
567 $_[0]{autocork} = $_[1];
568}
569
570=item $handle->no_delay ($boolean)
571
572Enables or disables the C<no_delay> setting (see constructor argument of
573the same name for details).
574
575=cut
576
577sub no_delay {
578 $_[0]{no_delay} = $_[1];
579
580 eval {
581 local $SIG{__DIE__};
582 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]
583 if $_[0]{fh};
584 };
585}
586
587=item $handle->on_starttls ($cb)
588
589Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
590
591=cut
592
593sub on_starttls {
594 $_[0]{on_starttls} = $_[1];
595}
596
597=item $handle->on_stoptls ($cb)
598
599Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
600
601=cut
602
603sub on_starttls {
604 $_[0]{on_stoptls} = $_[1];
605}
606
607#############################################################################
608
609=item $handle->timeout ($seconds)
610
611Configures (or disables) the inactivity timeout.
612
613=cut
614
615sub timeout {
616 my ($self, $timeout) = @_;
617
618 $self->{timeout} = $timeout;
619 $self->_timeout;
620}
621
622# reset the timeout watcher, as neccessary
623# also check for time-outs
624sub _timeout {
625 my ($self) = @_;
626
627 if ($self->{timeout} && $self->{fh}) {
628 my $NOW = AnyEvent->now;
629
630 # when would the timeout trigger?
631 my $after = $self->{_activity} + $self->{timeout} - $NOW;
632
633 # now or in the past already?
634 if ($after <= 0) {
635 $self->{_activity} = $NOW;
636
637 if ($self->{on_timeout}) {
638 $self->{on_timeout}($self);
639 } else {
640 $self->_error (Errno::ETIMEDOUT);
641 }
642
643 # callback could have changed timeout value, optimise
644 return unless $self->{timeout};
645
646 # calculate new after
647 $after = $self->{timeout};
648 }
649
650 Scalar::Util::weaken $self;
651 return unless $self; # ->error could have destroyed $self
652
653 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
654 delete $self->{_tw};
655 $self->_timeout;
656 });
657 } else {
658 delete $self->{_tw};
659 }
660}
661
205############################################################################# 662#############################################################################
206 663
207=back 664=back
208 665
209=head2 WRITE QUEUE 666=head2 WRITE QUEUE
212for reading. 669for reading.
213 670
214The write queue is very simple: you can add data to its end, and 671The write queue is very simple: you can add data to its end, and
215AnyEvent::Handle will automatically try to get rid of it for you. 672AnyEvent::Handle will automatically try to get rid of it for you.
216 673
217When data could be writtena nd the write buffer is shorter then the low 674When data could be written and the write buffer is shorter then the low
218water mark, the C<on_drain> callback will be invoked. 675water mark, the C<on_drain> callback will be invoked.
219 676
220=over 4 677=over 4
221 678
222=item $handle->on_drain ($cb) 679=item $handle->on_drain ($cb)
230 my ($self, $cb) = @_; 687 my ($self, $cb) = @_;
231 688
232 $self->{on_drain} = $cb; 689 $self->{on_drain} = $cb;
233 690
234 $cb->($self) 691 $cb->($self)
235 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 692 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
236} 693}
237 694
238=item $handle->push_write ($data) 695=item $handle->push_write ($data)
239 696
240Queues the given scalar to be written. You can push as much data as you 697Queues the given scalar to be written. You can push as much data as you
241want (only limited by the available memory), as C<AnyEvent::Handle> 698want (only limited by the available memory), as C<AnyEvent::Handle>
242buffers it independently of the kernel. 699buffers it independently of the kernel.
243 700
244=cut 701=cut
245 702
246sub push_write { 703sub _drain_wbuf {
247 my ($self, $data) = @_; 704 my ($self) = @_;
248 705
249 $self->{wbuf} .= $data; 706 if (!$self->{_ww} && length $self->{wbuf}) {
250 707
251 unless ($self->{ww}) {
252 Scalar::Util::weaken $self; 708 Scalar::Util::weaken $self;
709
253 my $cb = sub { 710 my $cb = sub {
254 my $len = syswrite $self->{fh}, $self->{wbuf}; 711 my $len = syswrite $self->{fh}, $self->{wbuf};
255 712
256 if ($len > 0) { 713 if (defined $len) {
257 substr $self->{wbuf}, 0, $len, ""; 714 substr $self->{wbuf}, 0, $len, "";
258 715
716 $self->{_activity} = AnyEvent->now;
259 717
260 $self->{on_drain}($self) 718 $self->{on_drain}($self)
261 if $self->{low_water_mark} >= length $self->{wbuf} 719 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
262 && $self->{on_drain}; 720 && $self->{on_drain};
263 721
264 delete $self->{ww} unless length $self->{wbuf}; 722 delete $self->{_ww} unless length $self->{wbuf};
265 } elsif ($! != EAGAIN && $! != EINTR) { 723 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
266 $self->error; 724 $self->_error ($!, 1);
267 } 725 }
268 }; 726 };
269 727
728 # try to write data immediately
729 $cb->() unless $self->{autocork};
730
731 # if still data left in wbuf, we need to poll
270 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 732 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
271 733 if length $self->{wbuf};
272 $cb->($self);
273 }; 734 };
274} 735}
736
737our %WH;
738
739sub register_write_type($$) {
740 $WH{$_[0]} = $_[1];
741}
742
743sub push_write {
744 my $self = shift;
745
746 if (@_ > 1) {
747 my $type = shift;
748
749 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
750 ->($self, @_);
751 }
752
753 if ($self->{tls}) {
754 $self->{_tls_wbuf} .= $_[0];
755 &_dotls ($self) if $self->{fh};
756 } else {
757 $self->{wbuf} .= $_[0];
758 $self->_drain_wbuf if $self->{fh};
759 }
760}
761
762=item $handle->push_write (type => @args)
763
764Instead of formatting your data yourself, you can also let this module do
765the job by specifying a type and type-specific arguments.
766
767Predefined types are (if you have ideas for additional types, feel free to
768drop by and tell us):
769
770=over 4
771
772=item netstring => $string
773
774Formats the given value as netstring
775(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
776
777=cut
778
779register_write_type netstring => sub {
780 my ($self, $string) = @_;
781
782 (length $string) . ":$string,"
783};
784
785=item packstring => $format, $data
786
787An octet string prefixed with an encoded length. The encoding C<$format>
788uses the same format as a Perl C<pack> format, but must specify a single
789integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
790optional C<!>, C<< < >> or C<< > >> modifier).
791
792=cut
793
794register_write_type packstring => sub {
795 my ($self, $format, $string) = @_;
796
797 pack "$format/a*", $string
798};
799
800=item json => $array_or_hashref
801
802Encodes the given hash or array reference into a JSON object. Unless you
803provide your own JSON object, this means it will be encoded to JSON text
804in UTF-8.
805
806JSON objects (and arrays) are self-delimiting, so you can write JSON at
807one end of a handle and read them at the other end without using any
808additional framing.
809
810The generated JSON text is guaranteed not to contain any newlines: While
811this module doesn't need delimiters after or between JSON texts to be
812able to read them, many other languages depend on that.
813
814A simple RPC protocol that interoperates easily with others is to send
815JSON arrays (or objects, although arrays are usually the better choice as
816they mimic how function argument passing works) and a newline after each
817JSON text:
818
819 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
820 $handle->push_write ("\012");
821
822An AnyEvent::Handle receiver would simply use the C<json> read type and
823rely on the fact that the newline will be skipped as leading whitespace:
824
825 $handle->push_read (json => sub { my $array = $_[1]; ... });
826
827Other languages could read single lines terminated by a newline and pass
828this line into their JSON decoder of choice.
829
830=cut
831
832register_write_type json => sub {
833 my ($self, $ref) = @_;
834
835 require JSON;
836
837 $self->{json} ? $self->{json}->encode ($ref)
838 : JSON::encode_json ($ref)
839};
840
841=item storable => $reference
842
843Freezes the given reference using L<Storable> and writes it to the
844handle. Uses the C<nfreeze> format.
845
846=cut
847
848register_write_type storable => sub {
849 my ($self, $ref) = @_;
850
851 require Storable;
852
853 pack "w/a*", Storable::nfreeze ($ref)
854};
855
856=back
857
858=item $handle->push_shutdown
859
860Sometimes you know you want to close the socket after writing your data
861before it was actually written. One way to do that is to replace your
862C<on_drain> handler by a callback that shuts down the socket (and set
863C<low_water_mark> to C<0>). This method is a shorthand for just that, and
864replaces the C<on_drain> callback with:
865
866 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
867
868This simply shuts down the write side and signals an EOF condition to the
869the peer.
870
871You can rely on the normal read queue and C<on_eof> handling
872afterwards. This is the cleanest way to close a connection.
873
874=cut
875
876sub push_shutdown {
877 my ($self) = @_;
878
879 delete $self->{low_water_mark};
880 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
881}
882
883=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
884
885This function (not method) lets you add your own types to C<push_write>.
886Whenever the given C<type> is used, C<push_write> will invoke the code
887reference with the handle object and the remaining arguments.
888
889The code reference is supposed to return a single octet string that will
890be appended to the write buffer.
891
892Note that this is a function, and all types registered this way will be
893global, so try to use unique names.
894
895=cut
275 896
276############################################################################# 897#############################################################################
277 898
278=back 899=back
279 900
286ways, the "simple" way, using only C<on_read> and the "complex" way, using 907ways, the "simple" way, using only C<on_read> and the "complex" way, using
287a queue. 908a queue.
288 909
289In the simple case, you just install an C<on_read> callback and whenever 910In the simple case, you just install an C<on_read> callback and whenever
290new data arrives, it will be called. You can then remove some data (if 911new data arrives, it will be called. You can then remove some data (if
291enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 912enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
292or not. 913leave the data there if you want to accumulate more (e.g. when only a
914partial message has been received so far).
293 915
294In the more complex case, you want to queue multiple callbacks. In this 916In the more complex case, you want to queue multiple callbacks. In this
295case, AnyEvent::Handle will call the first queued callback each time new 917case, AnyEvent::Handle will call the first queued callback each time new
296data arrives and removes it when it has done its job (see C<push_read>, 918data arrives (also the first time it is queued) and removes it when it has
297below). 919done its job (see C<push_read>, below).
298 920
299This way you can, for example, push three line-reads, followed by reading 921This way you can, for example, push three line-reads, followed by reading
300a chunk of data, and AnyEvent::Handle will execute them in order. 922a chunk of data, and AnyEvent::Handle will execute them in order.
301 923
302Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 924Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
303the specified number of bytes which give an XML datagram. 925the specified number of bytes which give an XML datagram.
304 926
305 # in the default state, expect some header bytes 927 # in the default state, expect some header bytes
306 $handle->on_read (sub { 928 $handle->on_read (sub {
307 # some data is here, now queue the length-header-read (4 octets) 929 # some data is here, now queue the length-header-read (4 octets)
308 shift->unshift_read_chunk (4, sub { 930 shift->unshift_read (chunk => 4, sub {
309 # header arrived, decode 931 # header arrived, decode
310 my $len = unpack "N", $_[1]; 932 my $len = unpack "N", $_[1];
311 933
312 # now read the payload 934 # now read the payload
313 shift->unshift_read_chunk ($len, sub { 935 shift->unshift_read (chunk => $len, sub {
314 my $xml = $_[1]; 936 my $xml = $_[1];
315 # handle xml 937 # handle xml
316 }); 938 });
317 }); 939 });
318 }); 940 });
319 941
320Example 2: Implement a client for a protocol that replies either with 942Example 2: Implement a client for a protocol that replies either with "OK"
321"OK" and another line or "ERROR" for one request, and 64 bytes for the 943and another line or "ERROR" for the first request that is sent, and 64
322second request. Due tot he availability of a full queue, we can just 944bytes for the second request. Due to the availability of a queue, we can
323pipeline sending both requests and manipulate the queue as necessary in 945just pipeline sending both requests and manipulate the queue as necessary
324the callbacks: 946in the callbacks.
325 947
326 # request one 948When the first callback is called and sees an "OK" response, it will
949C<unshift> another line-read. This line-read will be queued I<before> the
95064-byte chunk callback.
951
952 # request one, returns either "OK + extra line" or "ERROR"
327 $handle->push_write ("request 1\015\012"); 953 $handle->push_write ("request 1\015\012");
328 954
329 # we expect "ERROR" or "OK" as response, so push a line read 955 # we expect "ERROR" or "OK" as response, so push a line read
330 $handle->push_read_line (sub { 956 $handle->push_read (line => sub {
331 # if we got an "OK", we have to _prepend_ another line, 957 # if we got an "OK", we have to _prepend_ another line,
332 # so it will be read before the second request reads its 64 bytes 958 # so it will be read before the second request reads its 64 bytes
333 # which are already in the queue when this callback is called 959 # which are already in the queue when this callback is called
334 # we don't do this in case we got an error 960 # we don't do this in case we got an error
335 if ($_[1] eq "OK") { 961 if ($_[1] eq "OK") {
336 $_[0]->unshift_read_line (sub { 962 $_[0]->unshift_read (line => sub {
337 my $response = $_[1]; 963 my $response = $_[1];
338 ... 964 ...
339 }); 965 });
340 } 966 }
341 }); 967 });
342 968
343 # request two 969 # request two, simply returns 64 octets
344 $handle->push_write ("request 2\015\012"); 970 $handle->push_write ("request 2\015\012");
345 971
346 # simply read 64 bytes, always 972 # simply read 64 bytes, always
347 $handle->push_read_chunk (64, sub { 973 $handle->push_read (chunk => 64, sub {
348 my $response = $_[1]; 974 my $response = $_[1];
349 ... 975 ...
350 }); 976 });
351 977
352=over 4 978=over 4
353 979
980=cut
981
354sub _drain_rbuf { 982sub _drain_rbuf {
355 my ($self) = @_; 983 my ($self) = @_;
356 984
985 # avoid recursion
357 return if exists $self->{in_drain}; 986 return if exists $self->{_skip_drain_rbuf};
358 local $self->{in_drain} = 1; 987 local $self->{_skip_drain_rbuf} = 1;
359 988
989 if (
990 defined $self->{rbuf_max}
991 && $self->{rbuf_max} < length $self->{rbuf}
992 ) {
993 $self->_error (Errno::ENOSPC, 1), return;
994 }
995
996 while () {
997 # we need to use a separate tls read buffer, as we must not receive data while
998 # we are draining the buffer, and this can only happen with TLS.
999 $self->{rbuf} .= delete $self->{_tls_rbuf}
1000 if exists $self->{_tls_rbuf};
1001
360 while (my $len = length $self->{rbuf}) { 1002 my $len = length $self->{rbuf};
361 no strict 'refs'; 1003
362 if (@{ $self->{queue} }) { 1004 if (my $cb = shift @{ $self->{_queue} }) {
363 if ($self->{queue}[0]($self)) { 1005 unless ($cb->($self)) {
1006 # no progress can be made
1007 # (not enough data and no data forthcoming)
1008 $self->_error (Errno::EPIPE, 1), return
1009 if $self->{_eof};
1010
364 shift @{ $self->{queue} }; 1011 unshift @{ $self->{_queue} }, $cb;
365 } elsif ($self->{eof}) {
366 # no progress can be made (not enough data and no data forthcoming)
367 $! = &Errno::EPIPE; return $self->error;
368 } else {
369 return; 1012 last;
370 } 1013 }
371 } elsif ($self->{on_read}) { 1014 } elsif ($self->{on_read}) {
1015 last unless $len;
1016
372 $self->{on_read}($self); 1017 $self->{on_read}($self);
373 1018
374 if ( 1019 if (
375 $self->{eof} # if no further data will arrive
376 && $len == length $self->{rbuf} # and no data has been consumed 1020 $len == length $self->{rbuf} # if no data has been consumed
377 && !@{ $self->{queue} } # and the queue is still empty 1021 && !@{ $self->{_queue} } # and the queue is still empty
378 && $self->{on_read} # and we still want to read data 1022 && $self->{on_read} # but we still have on_read
379 ) { 1023 ) {
1024 # no further data will arrive
380 # then no progress can be made 1025 # so no progress can be made
381 $! = &Errno::EPIPE; return $self->error; 1026 $self->_error (Errno::EPIPE, 1), return
1027 if $self->{_eof};
1028
1029 last; # more data might arrive
382 } 1030 }
383 } else { 1031 } else {
384 # read side becomes idle 1032 # read side becomes idle
385 delete $self->{rw}; 1033 delete $self->{_rw} unless $self->{tls};
386 return; 1034 last;
387 } 1035 }
388 } 1036 }
389 1037
390 if ($self->{eof}) { 1038 if ($self->{_eof}) {
391 $self->_shutdown; 1039 $self->{on_eof}
392 $self->{on_eof}($self); 1040 ? $self->{on_eof}($self)
1041 : $self->_error (0, 1, "Unexpected end-of-file");
1042
1043 return;
1044 }
1045
1046 # may need to restart read watcher
1047 unless ($self->{_rw}) {
1048 $self->start_read
1049 if $self->{on_read} || @{ $self->{_queue} };
393 } 1050 }
394} 1051}
395 1052
396=item $handle->on_read ($cb) 1053=item $handle->on_read ($cb)
397 1054
403 1060
404sub on_read { 1061sub on_read {
405 my ($self, $cb) = @_; 1062 my ($self, $cb) = @_;
406 1063
407 $self->{on_read} = $cb; 1064 $self->{on_read} = $cb;
408
409 unless ($self->{rw} || $self->{eof}) {
410 Scalar::Util::weaken $self;
411
412 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
413 my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};
414
415 if ($len > 0) {
416 if (exists $self->{rbuf_max}) {
417 if ($self->{rbuf_max} < length $self->{rbuf}) {
418 $! = &Errno::ENOSPC; return $self->error;
419 }
420 }
421
422 } elsif (defined $len) {
423 $self->{eof} = 1;
424 delete $self->{rw};
425
426 } elsif ($! != EAGAIN && $! != EINTR) {
427 return $self->error;
428 }
429
430 $self->_drain_rbuf; 1065 $self->_drain_rbuf if $cb;
431 });
432 }
433} 1066}
434 1067
435=item $handle->rbuf 1068=item $handle->rbuf
436 1069
437Returns the read buffer (as a modifiable lvalue). 1070Returns the read buffer (as a modifiable lvalue).
438 1071
439You can access the read buffer directly as the C<< ->{rbuf} >> member, if 1072You can access the read buffer directly as the C<< ->{rbuf} >>
440you want. 1073member, if you want. However, the only operation allowed on the
1074read buffer (apart from looking at it) is removing data from its
1075beginning. Otherwise modifying or appending to it is not allowed and will
1076lead to hard-to-track-down bugs.
441 1077
442NOTE: The read buffer should only be used or modified if the C<on_read>, 1078NOTE: The read buffer should only be used or modified if the C<on_read>,
443C<push_read> or C<unshift_read> methods are used. The other read methods 1079C<push_read> or C<unshift_read> methods are used. The other read methods
444automatically manage the read buffer. 1080automatically manage the read buffer.
445 1081
456Append the given callback to the end of the queue (C<push_read>) or 1092Append the given callback to the end of the queue (C<push_read>) or
457prepend it (C<unshift_read>). 1093prepend it (C<unshift_read>).
458 1094
459The callback is called each time some additional read data arrives. 1095The callback is called each time some additional read data arrives.
460 1096
461It must check wether enough data is in the read buffer already. 1097It must check whether enough data is in the read buffer already.
462 1098
463If not enough data is available, it must return the empty list or a false 1099If not enough data is available, it must return the empty list or a false
464value, in which case it will be called repeatedly until enough data is 1100value, in which case it will be called repeatedly until enough data is
465available (or an error condition is detected). 1101available (or an error condition is detected).
466 1102
468interested in (which can be none at all) and return a true value. After returning 1104interested in (which can be none at all) and return a true value. After returning
469true, it will be removed from the queue. 1105true, it will be removed from the queue.
470 1106
471=cut 1107=cut
472 1108
1109our %RH;
1110
1111sub register_read_type($$) {
1112 $RH{$_[0]} = $_[1];
1113}
1114
473sub push_read { 1115sub push_read {
474 my ($self, $cb) = @_; 1116 my $self = shift;
1117 my $cb = pop;
475 1118
1119 if (@_) {
1120 my $type = shift;
1121
1122 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
1123 ->($self, $cb, @_);
1124 }
1125
476 push @{ $self->{queue} }, $cb; 1126 push @{ $self->{_queue} }, $cb;
477 $self->_drain_rbuf; 1127 $self->_drain_rbuf;
478} 1128}
479 1129
480sub unshift_read { 1130sub unshift_read {
481 my ($self, $cb) = @_; 1131 my $self = shift;
1132 my $cb = pop;
482 1133
1134 if (@_) {
1135 my $type = shift;
1136
1137 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
1138 ->($self, $cb, @_);
1139 }
1140
1141
483 push @{ $self->{queue} }, $cb; 1142 unshift @{ $self->{_queue} }, $cb;
484 $self->_drain_rbuf; 1143 $self->_drain_rbuf;
485} 1144}
486 1145
487=item $handle->push_read_chunk ($len, $cb->($self, $data)) 1146=item $handle->push_read (type => @args, $cb)
488 1147
489=item $handle->unshift_read_chunk ($len, $cb->($self, $data)) 1148=item $handle->unshift_read (type => @args, $cb)
490 1149
491Append the given callback to the end of the queue (C<push_read_chunk>) or 1150Instead of providing a callback that parses the data itself you can chose
492prepend it (C<unshift_read_chunk>). 1151between a number of predefined parsing formats, for chunks of data, lines
1152etc.
493 1153
494The callback will be called only once C<$len> bytes have been read, and 1154Predefined types are (if you have ideas for additional types, feel free to
495these C<$len> bytes will be passed to the callback. 1155drop by and tell us):
496 1156
497=cut 1157=over 4
498 1158
499sub _read_chunk($$) { 1159=item chunk => $octets, $cb->($handle, $data)
500 my ($len, $cb) = @_; 1160
1161Invoke the callback only once C<$octets> bytes have been read. Pass the
1162data read to the callback. The callback will never be called with less
1163data.
1164
1165Example: read 2 bytes.
1166
1167 $handle->push_read (chunk => 2, sub {
1168 warn "yay ", unpack "H*", $_[1];
1169 });
1170
1171=cut
1172
1173register_read_type chunk => sub {
1174 my ($self, $cb, $len) = @_;
501 1175
502 sub { 1176 sub {
503 $len <= length $_[0]{rbuf} or return; 1177 $len <= length $_[0]{rbuf} or return;
504 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1178 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
505 1 1179 1
506 } 1180 }
507} 1181};
508 1182
509sub push_read_chunk { 1183=item line => [$eol, ]$cb->($handle, $line, $eol)
510 my ($self, $len, $cb) = @_;
511
512 $self->push_read (_read_chunk $len, $cb);
513}
514
515
516sub unshift_read_chunk {
517 my ($self, $len, $cb) = @_;
518
519 $self->unshift_read (_read_chunk $len, $cb);
520}
521
522=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
523
524=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
525
526Append the given callback to the end of the queue (C<push_read_line>) or
527prepend it (C<unshift_read_line>).
528 1184
529The callback will be called only once a full line (including the end of 1185The callback will be called only once a full line (including the end of
530line marker, C<$eol>) has been read. This line (excluding the end of line 1186line marker, C<$eol>) has been read. This line (excluding the end of line
531marker) will be passed to the callback as second argument (C<$line>), and 1187marker) will be passed to the callback as second argument (C<$line>), and
532the end of line marker as the third argument (C<$eol>). 1188the end of line marker as the third argument (C<$eol>).
543Partial lines at the end of the stream will never be returned, as they are 1199Partial lines at the end of the stream will never be returned, as they are
544not marked by the end of line marker. 1200not marked by the end of line marker.
545 1201
546=cut 1202=cut
547 1203
548sub _read_line($$) { 1204register_read_type line => sub {
549 my $cb = pop; 1205 my ($self, $cb, $eol) = @_;
550 my $eol = @_ ? shift : qr|(\015?\012)|;
551 my $pos;
552 1206
1207 if (@_ < 3) {
1208 # this is more than twice as fast as the generic code below
1209 sub {
1210 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1211
1212 $cb->($_[0], $1, $2);
1213 1
1214 }
1215 } else {
553 $eol = qr|(\Q$eol\E)| unless ref $eol; 1216 $eol = quotemeta $eol unless ref $eol;
554 $eol = qr|^(.*?)($eol)|; 1217 $eol = qr|^(.*?)($eol)|s;
1218
1219 sub {
1220 $_[0]{rbuf} =~ s/$eol// or return;
1221
1222 $cb->($_[0], $1, $2);
1223 1
1224 }
1225 }
1226};
1227
1228=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
1229
1230Makes a regex match against the regex object C<$accept> and returns
1231everything up to and including the match.
1232
1233Example: read a single line terminated by '\n'.
1234
1235 $handle->push_read (regex => qr<\n>, sub { ... });
1236
1237If C<$reject> is given and not undef, then it determines when the data is
1238to be rejected: it is matched against the data when the C<$accept> regex
1239does not match and generates an C<EBADMSG> error when it matches. This is
1240useful to quickly reject wrong data (to avoid waiting for a timeout or a
1241receive buffer overflow).
1242
1243Example: expect a single decimal number followed by whitespace, reject
1244anything else (not the use of an anchor).
1245
1246 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1247
1248If C<$skip> is given and not C<undef>, then it will be matched against
1249the receive buffer when neither C<$accept> nor C<$reject> match,
1250and everything preceding and including the match will be accepted
1251unconditionally. This is useful to skip large amounts of data that you
1252know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1253have to start matching from the beginning. This is purely an optimisation
1254and is usually worth only when you expect more than a few kilobytes.
1255
1256Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1257expect the header to be very large (it isn't in practise, but...), we use
1258a skip regex to skip initial portions. The skip regex is tricky in that
1259it only accepts something not ending in either \015 or \012, as these are
1260required for the accept regex.
1261
1262 $handle->push_read (regex =>
1263 qr<\015\012\015\012>,
1264 undef, # no reject
1265 qr<^.*[^\015\012]>,
1266 sub { ... });
1267
1268=cut
1269
1270register_read_type regex => sub {
1271 my ($self, $cb, $accept, $reject, $skip) = @_;
1272
1273 my $data;
1274 my $rbuf = \$self->{rbuf};
555 1275
556 sub { 1276 sub {
557 $_[0]{rbuf} =~ s/$eol// or return; 1277 # accept
1278 if ($$rbuf =~ $accept) {
1279 $data .= substr $$rbuf, 0, $+[0], "";
1280 $cb->($self, $data);
1281 return 1;
1282 }
1283
1284 # reject
1285 if ($reject && $$rbuf =~ $reject) {
1286 $self->_error (Errno::EBADMSG);
1287 }
558 1288
559 $cb->($1, $2); 1289 # skip
1290 if ($skip && $$rbuf =~ $skip) {
1291 $data .= substr $$rbuf, 0, $+[0], "";
1292 }
1293
1294 ()
1295 }
1296};
1297
1298=item netstring => $cb->($handle, $string)
1299
1300A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1301
1302Throws an error with C<$!> set to EBADMSG on format violations.
1303
1304=cut
1305
1306register_read_type netstring => sub {
1307 my ($self, $cb) = @_;
1308
1309 sub {
1310 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1311 if ($_[0]{rbuf} =~ /[^0-9]/) {
1312 $self->_error (Errno::EBADMSG);
1313 }
1314 return;
1315 }
1316
1317 my $len = $1;
1318
1319 $self->unshift_read (chunk => $len, sub {
1320 my $string = $_[1];
1321 $_[0]->unshift_read (chunk => 1, sub {
1322 if ($_[1] eq ",") {
1323 $cb->($_[0], $string);
1324 } else {
1325 $self->_error (Errno::EBADMSG);
1326 }
1327 });
1328 });
1329
560 1 1330 1
561 } 1331 }
562} 1332};
563 1333
564sub push_read_line { 1334=item packstring => $format, $cb->($handle, $string)
565 my $self = shift;
566 1335
567 $self->push_read (&_read_line); 1336An octet string prefixed with an encoded length. The encoding C<$format>
568} 1337uses the same format as a Perl C<pack> format, but must specify a single
1338integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1339optional C<!>, C<< < >> or C<< > >> modifier).
569 1340
570sub unshift_read_line { 1341For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
571 my $self = shift; 1342EPP uses a prefix of C<N> (4 octtes).
572 1343
573 $self->unshift_read (&_read_line); 1344Example: read a block of data prefixed by its length in BER-encoded
574} 1345format (very efficient).
1346
1347 $handle->push_read (packstring => "w", sub {
1348 my ($handle, $data) = @_;
1349 });
1350
1351=cut
1352
1353register_read_type packstring => sub {
1354 my ($self, $cb, $format) = @_;
1355
1356 sub {
1357 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1358 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1359 or return;
1360
1361 $format = length pack $format, $len;
1362
1363 # bypass unshift if we already have the remaining chunk
1364 if ($format + $len <= length $_[0]{rbuf}) {
1365 my $data = substr $_[0]{rbuf}, $format, $len;
1366 substr $_[0]{rbuf}, 0, $format + $len, "";
1367 $cb->($_[0], $data);
1368 } else {
1369 # remove prefix
1370 substr $_[0]{rbuf}, 0, $format, "";
1371
1372 # read remaining chunk
1373 $_[0]->unshift_read (chunk => $len, $cb);
1374 }
1375
1376 1
1377 }
1378};
1379
1380=item json => $cb->($handle, $hash_or_arrayref)
1381
1382Reads a JSON object or array, decodes it and passes it to the
1383callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1384
1385If a C<json> object was passed to the constructor, then that will be used
1386for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1387
1388This read type uses the incremental parser available with JSON version
13892.09 (and JSON::XS version 2.2) and above. You have to provide a
1390dependency on your own: this module will load the JSON module, but
1391AnyEvent does not depend on it itself.
1392
1393Since JSON texts are fully self-delimiting, the C<json> read and write
1394types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1395the C<json> write type description, above, for an actual example.
1396
1397=cut
1398
1399register_read_type json => sub {
1400 my ($self, $cb) = @_;
1401
1402 my $json = $self->{json} ||=
1403 eval { require JSON::XS; JSON::XS->new->utf8 }
1404 || do { require JSON; JSON->new->utf8 };
1405
1406 my $data;
1407 my $rbuf = \$self->{rbuf};
1408
1409 sub {
1410 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1411
1412 if ($ref) {
1413 $self->{rbuf} = $json->incr_text;
1414 $json->incr_text = "";
1415 $cb->($self, $ref);
1416
1417 1
1418 } elsif ($@) {
1419 # error case
1420 $json->incr_skip;
1421
1422 $self->{rbuf} = $json->incr_text;
1423 $json->incr_text = "";
1424
1425 $self->_error (Errno::EBADMSG);
1426
1427 ()
1428 } else {
1429 $self->{rbuf} = "";
1430
1431 ()
1432 }
1433 }
1434};
1435
1436=item storable => $cb->($handle, $ref)
1437
1438Deserialises a L<Storable> frozen representation as written by the
1439C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1440data).
1441
1442Raises C<EBADMSG> error if the data could not be decoded.
1443
1444=cut
1445
1446register_read_type storable => sub {
1447 my ($self, $cb) = @_;
1448
1449 require Storable;
1450
1451 sub {
1452 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1453 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1454 or return;
1455
1456 my $format = length pack "w", $len;
1457
1458 # bypass unshift if we already have the remaining chunk
1459 if ($format + $len <= length $_[0]{rbuf}) {
1460 my $data = substr $_[0]{rbuf}, $format, $len;
1461 substr $_[0]{rbuf}, 0, $format + $len, "";
1462 $cb->($_[0], Storable::thaw ($data));
1463 } else {
1464 # remove prefix
1465 substr $_[0]{rbuf}, 0, $format, "";
1466
1467 # read remaining chunk
1468 $_[0]->unshift_read (chunk => $len, sub {
1469 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1470 $cb->($_[0], $ref);
1471 } else {
1472 $self->_error (Errno::EBADMSG);
1473 }
1474 });
1475 }
1476
1477 1
1478 }
1479};
575 1480
576=back 1481=back
577 1482
1483=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
1484
1485This function (not method) lets you add your own types to C<push_read>.
1486
1487Whenever the given C<type> is used, C<push_read> will invoke the code
1488reference with the handle object, the callback and the remaining
1489arguments.
1490
1491The code reference is supposed to return a callback (usually a closure)
1492that works as a plain read callback (see C<< ->push_read ($cb) >>).
1493
1494It should invoke the passed callback when it is done reading (remember to
1495pass C<$handle> as first argument as all other callbacks do that).
1496
1497Note that this is a function, and all types registered this way will be
1498global, so try to use unique names.
1499
1500For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
1501search for C<register_read_type>)).
1502
1503=item $handle->stop_read
1504
1505=item $handle->start_read
1506
1507In rare cases you actually do not want to read anything from the
1508socket. In this case you can call C<stop_read>. Neither C<on_read> nor
1509any queued callbacks will be executed then. To start reading again, call
1510C<start_read>.
1511
1512Note that AnyEvent::Handle will automatically C<start_read> for you when
1513you change the C<on_read> callback or push/unshift a read callback, and it
1514will automatically C<stop_read> for you when neither C<on_read> is set nor
1515there are any read requests in the queue.
1516
1517These methods will have no effect when in TLS mode (as TLS doesn't support
1518half-duplex connections).
1519
1520=cut
1521
1522sub stop_read {
1523 my ($self) = @_;
1524
1525 delete $self->{_rw} unless $self->{tls};
1526}
1527
1528sub start_read {
1529 my ($self) = @_;
1530
1531 unless ($self->{_rw} || $self->{_eof}) {
1532 Scalar::Util::weaken $self;
1533
1534 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1535 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1536 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1537
1538 if ($len > 0) {
1539 $self->{_activity} = AnyEvent->now;
1540
1541 if ($self->{tls}) {
1542 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1543
1544 &_dotls ($self);
1545 } else {
1546 $self->_drain_rbuf;
1547 }
1548
1549 } elsif (defined $len) {
1550 delete $self->{_rw};
1551 $self->{_eof} = 1;
1552 $self->_drain_rbuf;
1553
1554 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1555 return $self->_error ($!, 1);
1556 }
1557 });
1558 }
1559}
1560
1561our $ERROR_SYSCALL;
1562our $ERROR_WANT_READ;
1563
1564sub _tls_error {
1565 my ($self, $err) = @_;
1566
1567 return $self->_error ($!, 1)
1568 if $err == Net::SSLeay::ERROR_SYSCALL ();
1569
1570 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1571
1572 # reduce error string to look less scary
1573 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1574
1575 if ($self->{_on_starttls}) {
1576 (delete $self->{_on_starttls})->($self, undef, $err);
1577 &_freetls;
1578 } else {
1579 &_freetls;
1580 $self->_error (Errno::EPROTO, 1, $err);
1581 }
1582}
1583
1584# poll the write BIO and send the data if applicable
1585# also decode read data if possible
1586# this is basiclaly our TLS state machine
1587# more efficient implementations are possible with openssl,
1588# but not with the buggy and incomplete Net::SSLeay.
1589sub _dotls {
1590 my ($self) = @_;
1591
1592 my $tmp;
1593
1594 if (length $self->{_tls_wbuf}) {
1595 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1596 substr $self->{_tls_wbuf}, 0, $tmp, "";
1597 }
1598
1599 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1600 return $self->_tls_error ($tmp)
1601 if $tmp != $ERROR_WANT_READ
1602 && ($tmp != $ERROR_SYSCALL || $!);
1603 }
1604
1605 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1606 unless (length $tmp) {
1607 $self->{_on_starttls}
1608 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1609 &_freetls;
1610
1611 if ($self->{on_stoptls}) {
1612 $self->{on_stoptls}($self);
1613 return;
1614 } else {
1615 # let's treat SSL-eof as we treat normal EOF
1616 delete $self->{_rw};
1617 $self->{_eof} = 1;
1618 }
1619 }
1620
1621 $self->{_tls_rbuf} .= $tmp;
1622 $self->_drain_rbuf;
1623 $self->{tls} or return; # tls session might have gone away in callback
1624 }
1625
1626 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1627 return $self->_tls_error ($tmp)
1628 if $tmp != $ERROR_WANT_READ
1629 && ($tmp != $ERROR_SYSCALL || $!);
1630
1631 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1632 $self->{wbuf} .= $tmp;
1633 $self->_drain_wbuf;
1634 }
1635
1636 $self->{_on_starttls}
1637 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1638 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1639}
1640
1641=item $handle->starttls ($tls[, $tls_ctx])
1642
1643Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1644object is created, you can also do that at a later time by calling
1645C<starttls>.
1646
1647Starting TLS is currently an asynchronous operation - when you push some
1648write data and then call C<< ->starttls >> then TLS negotiation will start
1649immediately, after which the queued write data is then sent.
1650
1651The first argument is the same as the C<tls> constructor argument (either
1652C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1653
1654The second argument is the optional C<AnyEvent::TLS> object that is used
1655when AnyEvent::Handle has to create its own TLS connection object, or
1656a hash reference with C<< key => value >> pairs that will be used to
1657construct a new context.
1658
1659The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1660context in C<< $handle->{tls_ctx} >> after this call and can be used or
1661changed to your liking. Note that the handshake might have already started
1662when this function returns.
1663
1664Due to bugs in OpenSSL, it might or might not be possible to do multiple
1665handshakes on the same stream. Best do not attempt to use the stream after
1666stopping TLS.
1667
1668=cut
1669
1670our %TLS_CACHE; #TODO not yet documented, should we?
1671
1672sub starttls {
1673 my ($self, $tls, $ctx) = @_;
1674
1675 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1676 if $self->{tls};
1677
1678 $self->{tls} = $tls;
1679 $self->{tls_ctx} = $ctx if @_ > 2;
1680
1681 return unless $self->{fh};
1682
1683 require Net::SSLeay;
1684
1685 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1686 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1687
1688 $tls = $self->{tls};
1689 $ctx = $self->{tls_ctx};
1690
1691 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1692
1693 if ("HASH" eq ref $ctx) {
1694 require AnyEvent::TLS;
1695
1696 if ($ctx->{cache}) {
1697 my $key = $ctx+0;
1698 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1699 } else {
1700 $ctx = new AnyEvent::TLS %$ctx;
1701 }
1702 }
1703
1704 $self->{tls_ctx} = $ctx || TLS_CTX ();
1705 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1706
1707 # basically, this is deep magic (because SSL_read should have the same issues)
1708 # but the openssl maintainers basically said: "trust us, it just works".
1709 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1710 # and mismaintained ssleay-module doesn't even offer them).
1711 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1712 #
1713 # in short: this is a mess.
1714 #
1715 # note that we do not try to keep the length constant between writes as we are required to do.
1716 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1717 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1718 # have identity issues in that area.
1719# Net::SSLeay::CTX_set_mode ($ssl,
1720# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1721# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1722 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1723
1724 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1725 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1726
1727 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1728
1729 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1730 if $self->{on_starttls};
1731
1732 &_dotls; # need to trigger the initial handshake
1733 $self->start_read; # make sure we actually do read
1734}
1735
1736=item $handle->stoptls
1737
1738Shuts down the SSL connection - this makes a proper EOF handshake by
1739sending a close notify to the other side, but since OpenSSL doesn't
1740support non-blocking shut downs, it is not guarenteed that you can re-use
1741the stream afterwards.
1742
1743=cut
1744
1745sub stoptls {
1746 my ($self) = @_;
1747
1748 if ($self->{tls}) {
1749 Net::SSLeay::shutdown ($self->{tls});
1750
1751 &_dotls;
1752
1753# # we don't give a shit. no, we do, but we can't. no...#d#
1754# # we, we... have to use openssl :/#d#
1755# &_freetls;#d#
1756 }
1757}
1758
1759sub _freetls {
1760 my ($self) = @_;
1761
1762 return unless $self->{tls};
1763
1764 $self->{tls_ctx}->_put_session (delete $self->{tls})
1765 if ref $self->{tls};
1766
1767 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1768}
1769
1770sub DESTROY {
1771 my ($self) = @_;
1772
1773 &_freetls;
1774
1775 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1776
1777 if ($linger && length $self->{wbuf} && $self->{fh}) {
1778 my $fh = delete $self->{fh};
1779 my $wbuf = delete $self->{wbuf};
1780
1781 my @linger;
1782
1783 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1784 my $len = syswrite $fh, $wbuf, length $wbuf;
1785
1786 if ($len > 0) {
1787 substr $wbuf, 0, $len, "";
1788 } else {
1789 @linger = (); # end
1790 }
1791 });
1792 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1793 @linger = ();
1794 });
1795 }
1796}
1797
1798=item $handle->destroy
1799
1800Shuts down the handle object as much as possible - this call ensures that
1801no further callbacks will be invoked and as many resources as possible
1802will be freed. You must not call any methods on the object afterwards.
1803
1804Normally, you can just "forget" any references to an AnyEvent::Handle
1805object and it will simply shut down. This works in fatal error and EOF
1806callbacks, as well as code outside. It does I<NOT> work in a read or write
1807callback, so when you want to destroy the AnyEvent::Handle object from
1808within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1809that case.
1810
1811Destroying the handle object in this way has the advantage that callbacks
1812will be removed as well, so if those are the only reference holders (as
1813is common), then one doesn't need to do anything special to break any
1814reference cycles.
1815
1816The handle might still linger in the background and write out remaining
1817data, as specified by the C<linger> option, however.
1818
1819=cut
1820
1821sub destroy {
1822 my ($self) = @_;
1823
1824 $self->DESTROY;
1825 %$self = ();
1826 bless $self, "AnyEvent::Handle::destroyed";
1827}
1828
1829{
1830 package AnyEvent::Handle::destroyed;
1831
1832 sub AUTOLOAD {
1833 #nop
1834 }
1835}
1836
1837=item AnyEvent::Handle::TLS_CTX
1838
1839This function creates and returns the AnyEvent::TLS object used by default
1840for TLS mode.
1841
1842The context is created by calling L<AnyEvent::TLS> without any arguments.
1843
1844=cut
1845
1846our $TLS_CTX;
1847
1848sub TLS_CTX() {
1849 $TLS_CTX ||= do {
1850 require AnyEvent::TLS;
1851
1852 new AnyEvent::TLS
1853 }
1854}
1855
1856=back
1857
1858
1859=head1 NONFREQUENTLY ASKED QUESTIONS
1860
1861=over 4
1862
1863=item I C<undef> the AnyEvent::Handle reference inside my callback and
1864still get further invocations!
1865
1866That's because AnyEvent::Handle keeps a reference to itself when handling
1867read or write callbacks.
1868
1869It is only safe to "forget" the reference inside EOF or error callbacks,
1870from within all other callbacks, you need to explicitly call the C<<
1871->destroy >> method.
1872
1873=item I get different callback invocations in TLS mode/Why can't I pause
1874reading?
1875
1876Unlike, say, TCP, TLS connections do not consist of two independent
1877communication channels, one for each direction. Or put differently. The
1878read and write directions are not independent of each other: you cannot
1879write data unless you are also prepared to read, and vice versa.
1880
1881This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1882callback invocations when you are not expecting any read data - the reason
1883is that AnyEvent::Handle always reads in TLS mode.
1884
1885During the connection, you have to make sure that you always have a
1886non-empty read-queue, or an C<on_read> watcher. At the end of the
1887connection (or when you no longer want to use it) you can call the
1888C<destroy> method.
1889
1890=item How do I read data until the other side closes the connection?
1891
1892If you just want to read your data into a perl scalar, the easiest way
1893to achieve this is by setting an C<on_read> callback that does nothing,
1894clearing the C<on_eof> callback and in the C<on_error> callback, the data
1895will be in C<$_[0]{rbuf}>:
1896
1897 $handle->on_read (sub { });
1898 $handle->on_eof (undef);
1899 $handle->on_error (sub {
1900 my $data = delete $_[0]{rbuf};
1901 });
1902
1903The reason to use C<on_error> is that TCP connections, due to latencies
1904and packets loss, might get closed quite violently with an error, when in
1905fact, all data has been received.
1906
1907It is usually better to use acknowledgements when transferring data,
1908to make sure the other side hasn't just died and you got the data
1909intact. This is also one reason why so many internet protocols have an
1910explicit QUIT command.
1911
1912=item I don't want to destroy the handle too early - how do I wait until
1913all data has been written?
1914
1915After writing your last bits of data, set the C<on_drain> callback
1916and destroy the handle in there - with the default setting of
1917C<low_water_mark> this will be called precisely when all data has been
1918written to the socket:
1919
1920 $handle->push_write (...);
1921 $handle->on_drain (sub {
1922 warn "all data submitted to the kernel\n";
1923 undef $handle;
1924 });
1925
1926If you just want to queue some data and then signal EOF to the other side,
1927consider using C<< ->push_shutdown >> instead.
1928
1929=item I want to contact a TLS/SSL server, I don't care about security.
1930
1931If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
1932simply connect to it and then create the AnyEvent::Handle with the C<tls>
1933parameter:
1934
1935 tcp_connect $host, $port, sub {
1936 my ($fh) = @_;
1937
1938 my $handle = new AnyEvent::Handle
1939 fh => $fh,
1940 tls => "connect",
1941 on_error => sub { ... };
1942
1943 $handle->push_write (...);
1944 };
1945
1946=item I want to contact a TLS/SSL server, I do care about security.
1947
1948Then you should additionally enable certificate verification, including
1949peername verification, if the protocol you use supports it (see
1950L<AnyEvent::TLS>, C<verify_peername>).
1951
1952E.g. for HTTPS:
1953
1954 tcp_connect $host, $port, sub {
1955 my ($fh) = @_;
1956
1957 my $handle = new AnyEvent::Handle
1958 fh => $fh,
1959 peername => $host,
1960 tls => "connect",
1961 tls_ctx => { verify => 1, verify_peername => "https" },
1962 ...
1963
1964Note that you must specify the hostname you connected to (or whatever
1965"peername" the protocol needs) as the C<peername> argument, otherwise no
1966peername verification will be done.
1967
1968The above will use the system-dependent default set of trusted CA
1969certificates. If you want to check against a specific CA, add the
1970C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1971
1972 tls_ctx => {
1973 verify => 1,
1974 verify_peername => "https",
1975 ca_file => "my-ca-cert.pem",
1976 },
1977
1978=item I want to create a TLS/SSL server, how do I do that?
1979
1980Well, you first need to get a server certificate and key. You have
1981three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1982self-signed certificate (cheap. check the search engine of your choice,
1983there are many tutorials on the net) or c) make your own CA (tinyca2 is a
1984nice program for that purpose).
1985
1986Then create a file with your private key (in PEM format, see
1987L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
1988file should then look like this:
1989
1990 -----BEGIN RSA PRIVATE KEY-----
1991 ...header data
1992 ... lots of base64'y-stuff
1993 -----END RSA PRIVATE KEY-----
1994
1995 -----BEGIN CERTIFICATE-----
1996 ... lots of base64'y-stuff
1997 -----END CERTIFICATE-----
1998
1999The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2000specify this file as C<cert_file>:
2001
2002 tcp_server undef, $port, sub {
2003 my ($fh) = @_;
2004
2005 my $handle = new AnyEvent::Handle
2006 fh => $fh,
2007 tls => "accept",
2008 tls_ctx => { cert_file => "my-server-keycert.pem" },
2009 ...
2010
2011When you have intermediate CA certificates that your clients might not
2012know about, just append them to the C<cert_file>.
2013
2014=back
2015
2016
2017=head1 SUBCLASSING AnyEvent::Handle
2018
2019In many cases, you might want to subclass AnyEvent::Handle.
2020
2021To make this easier, a given version of AnyEvent::Handle uses these
2022conventions:
2023
2024=over 4
2025
2026=item * all constructor arguments become object members.
2027
2028At least initially, when you pass a C<tls>-argument to the constructor it
2029will end up in C<< $handle->{tls} >>. Those members might be changed or
2030mutated later on (for example C<tls> will hold the TLS connection object).
2031
2032=item * other object member names are prefixed with an C<_>.
2033
2034All object members not explicitly documented (internal use) are prefixed
2035with an underscore character, so the remaining non-C<_>-namespace is free
2036for use for subclasses.
2037
2038=item * all members not documented here and not prefixed with an underscore
2039are free to use in subclasses.
2040
2041Of course, new versions of AnyEvent::Handle may introduce more "public"
2042member variables, but thats just life, at least it is documented.
2043
2044=back
2045
578=head1 AUTHOR 2046=head1 AUTHOR
579 2047
580Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 2048Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
581 2049
582=cut 2050=cut

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