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Revision 1.28 by root, Sat May 24 22:27:11 2008 UTC vs.
Revision 1.146 by root, Wed Jul 8 13:46:46 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util (); 7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util (); 8use Scalar::Util ();
9use Carp (); 9use Carp ();
10use Fcntl (); 10use Fcntl ();
11use Errno qw/EAGAIN EINTR/; 11use Errno qw(EAGAIN EINTR);
12 12
13=head1 NAME 13=head1 NAME
14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17This module is experimental.
18
19=cut 17=cut
20 18
21our $VERSION = '0.04'; 19our $VERSION = 4.8;
22 20
23=head1 SYNOPSIS 21=head1 SYNOPSIS
24 22
25 use AnyEvent; 23 use AnyEvent;
26 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 25
28 my $cv = AnyEvent->condvar; 26 my $cv = AnyEvent->condvar;
29 27
30 my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN); 28 my $handle =
31
32 #TODO
33
34 # or use the constructor to pass the callback:
35
36 my $ae_fh2 =
37 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
38 fh => \*STDIN, 30 fh => \*STDIN,
39 on_eof => sub { 31 on_eof => sub {
40 $cv->broadcast; 32 $cv->send;
41 }, 33 },
42 #TODO
43 ); 34 );
44 35
45 $cv->wait; 36 # send some request line
37 $handle->push_write ("getinfo\015\012");
38
39 # read the response line
40 $handle->push_read (line => sub {
41 my ($handle, $line) = @_;
42 warn "read line <$line>\n";
43 $cv->send;
44 });
45
46 $cv->recv;
46 47
47=head1 DESCRIPTION 48=head1 DESCRIPTION
48 49
49This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
50filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
51on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
52 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
53In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
54means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
55treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
56 60
57All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
59 63
60=head1 METHODS 64=head1 METHODS
61 65
62=over 4 66=over 4
63 67
64=item B<new (%args)> 68=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
65 69
66The constructor supports these arguments (all as key => value pairs). 70The constructor supports these arguments (all as C<< key => value >> pairs).
67 71
68=over 4 72=over 4
69 73
70=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
71 75
72The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
73 77
74NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
75AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
76 81
77=item on_eof => $cb->($self) 82=item on_eof => $cb->($handle)
78 83
79Set the callback to be called on EOF. 84Set the callback to be called when an end-of-file condition is detected,
85i.e. in the case of a socket, when the other side has closed the
86connection cleanly.
80 87
88For sockets, this just means that the other side has stopped sending data,
89you can still try to write data, and, in fact, one can return from the EOF
90callback and continue writing data, as only the read part has been shut
91down.
92
81While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
82otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
83waiting for data. 95waiting for data.
84 96
85=item on_error => $cb->($self) 97If an EOF condition has been detected but no C<on_eof> callback has been
98set, then a fatal error will be raised with C<$!> set to <0>.
86 99
100=item on_error => $cb->($handle, $fatal, $message)
101
87This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
88occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
89or a read error. 104connect or a read error.
90 105
91The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$fatal> being true). On
92called. 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
112AnyEvent::Handle tries to find an appropriate error code for you to check
113against, but in some cases (TLS errors), this does not work well. It is
114recommended to always output the C<$message> argument in human-readable
115error messages (it's usually the same as C<"$!">).
116
117Non-fatal errors can be retried by simply returning, but it is recommended
118to simply ignore this parameter and instead abondon the handle object
119when this callback is invoked. Examples of non-fatal errors are timeouts
120C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
93 121
94On callback entrance, the value of C<$!> contains the operating system 122On callback entrance, the value of C<$!> contains the operating system
95error (or C<ENOSPC> or C<EPIPE>). 123error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
124C<EPROTO>).
96 125
97While not mandatory, it is I<highly> recommended to set this callback, as 126While not mandatory, it is I<highly> recommended to set this callback, as
98you will not be notified of errors otherwise. The default simply calls 127you will not be notified of errors otherwise. The default simply calls
99die. 128C<croak>.
100 129
101=item on_read => $cb->($self) 130=item on_read => $cb->($handle)
102 131
103This sets the default read callback, which is called when data arrives 132This sets the default read callback, which is called when data arrives
104and no read request is in the queue. 133and no read request is in the queue (unlike read queue callbacks, this
134callback will only be called when at least one octet of data is in the
135read buffer).
105 136
106To access (and remove data from) the read buffer, use the C<< ->rbuf >> 137To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107method or access the C<$self->{rbuf}> member directly. 138method or access the C<< $handle->{rbuf} >> member directly. Note that you
139must not enlarge or modify the read buffer, you can only remove data at
140the beginning from it.
108 141
109When an EOF condition is detected then AnyEvent::Handle will first try to 142When an EOF condition is detected then AnyEvent::Handle will first try to
110feed all the remaining data to the queued callbacks and C<on_read> before 143feed all the remaining data to the queued callbacks and C<on_read> before
111calling the C<on_eof> callback. If no progress can be made, then a fatal 144calling the C<on_eof> callback. If no progress can be made, then a fatal
112error will be raised (with C<$!> set to C<EPIPE>). 145error will be raised (with C<$!> set to C<EPIPE>).
113 146
114=item on_drain => $cb->() 147=item on_drain => $cb->($handle)
115 148
116This sets the callback that is called when the write buffer becomes empty 149This sets the callback that is called when the write buffer becomes empty
117(or when the callback is set and the buffer is empty already). 150(or when the callback is set and the buffer is empty already).
118 151
119To append to the write buffer, use the C<< ->push_write >> method. 152To append to the write buffer, use the C<< ->push_write >> method.
120 153
154This callback is useful when you don't want to put all of your write data
155into the queue at once, for example, when you want to write the contents
156of some file to the socket you might not want to read the whole file into
157memory and push it into the queue, but instead only read more data from
158the file when the write queue becomes empty.
159
160=item timeout => $fractional_seconds
161
162If non-zero, then this enables an "inactivity" timeout: whenever this many
163seconds pass without a successful read or write on the underlying file
164handle, the C<on_timeout> callback will be invoked (and if that one is
165missing, a non-fatal C<ETIMEDOUT> error will be raised).
166
167Note that timeout processing is also active when you currently do not have
168any outstanding read or write requests: If you plan to keep the connection
169idle then you should disable the timout temporarily or ignore the timeout
170in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
171restart the timeout.
172
173Zero (the default) disables this timeout.
174
175=item on_timeout => $cb->($handle)
176
177Called whenever the inactivity timeout passes. If you return from this
178callback, then the timeout will be reset as if some activity had happened,
179so this condition is not fatal in any way.
180
121=item rbuf_max => <bytes> 181=item rbuf_max => <bytes>
122 182
123If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 183If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124when the read buffer ever (strictly) exceeds this size. This is useful to 184when the read buffer ever (strictly) exceeds this size. This is useful to
125avoid denial-of-service attacks. 185avoid some forms of denial-of-service attacks.
126 186
127For example, a server accepting connections from untrusted sources should 187For example, a server accepting connections from untrusted sources should
128be configured to accept only so-and-so much data that it cannot act on 188be configured to accept only so-and-so much data that it cannot act on
129(for example, when expecting a line, an attacker could send an unlimited 189(for example, when expecting a line, an attacker could send an unlimited
130amount of data without a callback ever being called as long as the line 190amount of data without a callback ever being called as long as the line
131isn't finished). 191isn't finished).
132 192
193=item autocork => <boolean>
194
195When disabled (the default), then C<push_write> will try to immediately
196write the data to the handle, if possible. This avoids having to register
197a write watcher and wait for the next event loop iteration, but can
198be inefficient if you write multiple small chunks (on the wire, this
199disadvantage is usually avoided by your kernel's nagle algorithm, see
200C<no_delay>, but this option can save costly syscalls).
201
202When enabled, then writes will always be queued till the next event loop
203iteration. This is efficient when you do many small writes per iteration,
204but less efficient when you do a single write only per iteration (or when
205the write buffer often is full). It also increases write latency.
206
207=item no_delay => <boolean>
208
209When doing small writes on sockets, your operating system kernel might
210wait a bit for more data before actually sending it out. This is called
211the Nagle algorithm, and usually it is beneficial.
212
213In some situations you want as low a delay as possible, which can be
214accomplishd by setting this option to a true value.
215
216The default is your opertaing system's default behaviour (most likely
217enabled), this option explicitly enables or disables it, if possible.
218
133=item read_size => <bytes> 219=item read_size => <bytes>
134 220
135The default read block size (the amount of bytes this module will try to read 221The default read block size (the amount of bytes this module will
136on each [loop iteration). Default: C<4096>. 222try to read during each loop iteration, which affects memory
223requirements). Default: C<8192>.
137 224
138=item low_water_mark => <bytes> 225=item low_water_mark => <bytes>
139 226
140Sets the amount of bytes (default: C<0>) that make up an "empty" write 227Sets the amount of bytes (default: C<0>) that make up an "empty" write
141buffer: If the write reaches this size or gets even samller it is 228buffer: If the write reaches this size or gets even samller it is
142considered empty. 229considered empty.
143 230
231Sometimes it can be beneficial (for performance reasons) to add data to
232the write buffer before it is fully drained, but this is a rare case, as
233the operating system kernel usually buffers data as well, so the default
234is good in almost all cases.
235
236=item linger => <seconds>
237
238If non-zero (default: C<3600>), then the destructor of the
239AnyEvent::Handle object will check whether there is still outstanding
240write data and will install a watcher that will write this data to the
241socket. No errors will be reported (this mostly matches how the operating
242system treats outstanding data at socket close time).
243
244This will not work for partial TLS data that could not be encoded
245yet. This data will be lost. Calling the C<stoptls> method in time might
246help.
247
248=item peername => $string
249
250A string used to identify the remote site - usually the DNS hostname
251(I<not> IDN!) used to create the connection, rarely the IP address.
252
253Apart from being useful in error messages, this string is also used in TLS
254peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
255verification will be skipped when C<peername> is not specified or
256C<undef>.
257
144=item tls => "accept" | "connect" | Net::SSLeay::SSL object 258=item tls => "accept" | "connect" | Net::SSLeay::SSL object
145 259
146When this parameter is given, it enables TLS (SSL) mode, that means it 260When this parameter is given, it enables TLS (SSL) mode, that means
147will start making tls handshake and will transparently encrypt/decrypt 261AnyEvent will start a TLS handshake as soon as the conenction has been
148data. 262established and will transparently encrypt/decrypt data afterwards.
263
264All TLS protocol errors will be signalled as C<EPROTO>, with an
265appropriate error message.
149 266
150TLS mode requires Net::SSLeay to be installed (it will be loaded 267TLS mode requires Net::SSLeay to be installed (it will be loaded
151automatically when you try to create a TLS handle). 268automatically when you try to create a TLS handle): this module doesn't
269have a dependency on that module, so if your module requires it, you have
270to add the dependency yourself.
152 271
153For the TLS server side, use C<accept>, and for the TLS client side of a 272Unlike TCP, TLS has a server and client side: for the TLS server side, use
154connection, use C<connect> mode. 273C<accept>, and for the TLS client side of a connection, use C<connect>
274mode.
155 275
156You can also provide your own TLS connection object, but you have 276You can also provide your own TLS connection object, but you have
157to make sure that you call either C<Net::SSLeay::set_connect_state> 277to make sure that you call either C<Net::SSLeay::set_connect_state>
158or C<Net::SSLeay::set_accept_state> on it before you pass it to 278or C<Net::SSLeay::set_accept_state> on it before you pass it to
159AnyEvent::Handle. 279AnyEvent::Handle. Also, this module will take ownership of this connection
280object.
160 281
282At some future point, AnyEvent::Handle might switch to another TLS
283implementation, then the option to use your own session object will go
284away.
285
286B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
287passing in the wrong integer will lead to certain crash. This most often
288happens when one uses a stylish C<< tls => 1 >> and is surprised about the
289segmentation fault.
290
161See the C<starttls> method if you need to start TLs negotiation later. 291See the C<< ->starttls >> method for when need to start TLS negotiation later.
162 292
163=item tls_ctx => $ssl_ctx 293=item tls_ctx => $anyevent_tls
164 294
165Use the given Net::SSLeay::CTX object to create the new TLS connection 295Use the given C<AnyEvent::TLS> object to create the new TLS connection
166(unless a connection object was specified directly). If this parameter is 296(unless a connection object was specified directly). If this parameter is
167missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 297missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
168 298
299Instead of an object, you can also specify a hash reference with C<< key
300=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
301new TLS context object.
302
303=item on_starttls => $cb->($handle, $success[, $error_message])
304
305This callback will be invoked when the TLS/SSL handshake has finished. If
306C<$success> is true, then the TLS handshake succeeded, otherwise it failed
307(C<on_stoptls> will not be called in this case).
308
309The session in C<< $handle->{tls} >> can still be examined in this
310callback, even when the handshake was not successful.
311
312TLS handshake failures will not cause C<on_error> to be invoked when this
313callback is in effect, instead, the error message will be passed to C<on_starttls>.
314
315Without this callback, handshake failures lead to C<on_error> being
316called, as normal.
317
318Note that you cannot call C<starttls> right again in this callback. If you
319need to do that, start an zero-second timer instead whose callback can
320then call C<< ->starttls >> again.
321
322=item on_stoptls => $cb->($handle)
323
324When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
325set, then it will be invoked after freeing the TLS session. If it is not,
326then a TLS shutdown condition will be treated like a normal EOF condition
327on the handle.
328
329The session in C<< $handle->{tls} >> can still be examined in this
330callback.
331
332This callback will only be called on TLS shutdowns, not when the
333underlying handle signals EOF.
334
335=item json => JSON or JSON::XS object
336
337This is the json coder object used by the C<json> read and write types.
338
339If you don't supply it, then AnyEvent::Handle will create and use a
340suitable one (on demand), which will write and expect UTF-8 encoded JSON
341texts.
342
343Note that you are responsible to depend on the JSON module if you want to
344use this functionality, as AnyEvent does not have a dependency itself.
345
169=back 346=back
170 347
171=cut 348=cut
172
173our (%RH, %WH);
174
175sub register_read_type($$) {
176 $RH{$_[0]} = $_[1];
177}
178
179sub register_write_type($$) {
180 $WH{$_[0]} = $_[1];
181}
182 349
183sub new { 350sub new {
184 my $class = shift; 351 my $class = shift;
185
186 my $self = bless { @_ }, $class; 352 my $self = bless { @_ }, $class;
187 353
188 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 354 $self->{fh} or Carp::croak "mandatory argument fh is missing";
189 355
190 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 356 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
191 357
192 if ($self->{tls}) { 358 $self->{_activity} = AnyEvent->now;
193 require Net::SSLeay; 359 $self->_timeout;
360
361 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
362
194 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 363 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
195 } 364 if $self->{tls};
196 365
197 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
198 $self->on_error (delete $self->{on_error}) if $self->{on_error};
199 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 366 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
200 $self->on_read (delete $self->{on_read} ) if $self->{on_read};
201 367
202 $self->start_read; 368 $self->start_read
369 if $self->{on_read};
203 370
204 $self 371 $self->{fh} && $self
205} 372}
206 373
207sub _shutdown { 374sub _shutdown {
208 my ($self) = @_; 375 my ($self) = @_;
209 376
210 delete $self->{rw}; 377 delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
211 delete $self->{ww}; 378 $self->{_eof} = 1; # tell starttls et. al to stop trying
212 delete $self->{fh};
213}
214 379
380 &_freetls;
381}
382
215sub error { 383sub _error {
216 my ($self) = @_; 384 my ($self, $errno, $fatal, $message) = @_;
217 385
218 {
219 local $!;
220 $self->_shutdown; 386 $self->_shutdown
221 } 387 if $fatal;
388
389 $! = $errno;
390 $message ||= "$!";
222 391
223 if ($self->{on_error}) { 392 if ($self->{on_error}) {
224 $self->{on_error}($self); 393 $self->{on_error}($self, $fatal, $message);
225 } else { 394 } elsif ($self->{fh}) {
226 die "AnyEvent::Handle uncaught fatal error: $!"; 395 Carp::croak "AnyEvent::Handle uncaught error: $message";
227 } 396 }
228} 397}
229 398
230=item $fh = $handle->fh 399=item $fh = $handle->fh
231 400
232This method returns the file handle of the L<AnyEvent::Handle> object. 401This method returns the file handle used to create the L<AnyEvent::Handle> object.
233 402
234=cut 403=cut
235 404
236sub fh { $_[0]->{fh} } 405sub fh { $_[0]{fh} }
237 406
238=item $handle->on_error ($cb) 407=item $handle->on_error ($cb)
239 408
240Replace the current C<on_error> callback (see the C<on_error> constructor argument). 409Replace the current C<on_error> callback (see the C<on_error> constructor argument).
241 410
253 422
254sub on_eof { 423sub on_eof {
255 $_[0]{on_eof} = $_[1]; 424 $_[0]{on_eof} = $_[1];
256} 425}
257 426
427=item $handle->on_timeout ($cb)
428
429Replace the current C<on_timeout> callback, or disables the callback (but
430not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
431argument and method.
432
433=cut
434
435sub on_timeout {
436 $_[0]{on_timeout} = $_[1];
437}
438
439=item $handle->autocork ($boolean)
440
441Enables or disables the current autocork behaviour (see C<autocork>
442constructor argument). Changes will only take effect on the next write.
443
444=cut
445
446sub autocork {
447 $_[0]{autocork} = $_[1];
448}
449
450=item $handle->no_delay ($boolean)
451
452Enables or disables the C<no_delay> setting (see constructor argument of
453the same name for details).
454
455=cut
456
457sub no_delay {
458 $_[0]{no_delay} = $_[1];
459
460 eval {
461 local $SIG{__DIE__};
462 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
463 };
464}
465
466=item $handle->on_starttls ($cb)
467
468Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
469
470=cut
471
472sub on_starttls {
473 $_[0]{on_starttls} = $_[1];
474}
475
476=item $handle->on_stoptls ($cb)
477
478Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
479
480=cut
481
482sub on_starttls {
483 $_[0]{on_stoptls} = $_[1];
484}
485
486#############################################################################
487
488=item $handle->timeout ($seconds)
489
490Configures (or disables) the inactivity timeout.
491
492=cut
493
494sub timeout {
495 my ($self, $timeout) = @_;
496
497 $self->{timeout} = $timeout;
498 $self->_timeout;
499}
500
501# reset the timeout watcher, as neccessary
502# also check for time-outs
503sub _timeout {
504 my ($self) = @_;
505
506 if ($self->{timeout}) {
507 my $NOW = AnyEvent->now;
508
509 # when would the timeout trigger?
510 my $after = $self->{_activity} + $self->{timeout} - $NOW;
511
512 # now or in the past already?
513 if ($after <= 0) {
514 $self->{_activity} = $NOW;
515
516 if ($self->{on_timeout}) {
517 $self->{on_timeout}($self);
518 } else {
519 $self->_error (&Errno::ETIMEDOUT);
520 }
521
522 # callback could have changed timeout value, optimise
523 return unless $self->{timeout};
524
525 # calculate new after
526 $after = $self->{timeout};
527 }
528
529 Scalar::Util::weaken $self;
530 return unless $self; # ->error could have destroyed $self
531
532 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
533 delete $self->{_tw};
534 $self->_timeout;
535 });
536 } else {
537 delete $self->{_tw};
538 }
539}
540
258############################################################################# 541#############################################################################
259 542
260=back 543=back
261 544
262=head2 WRITE QUEUE 545=head2 WRITE QUEUE
283 my ($self, $cb) = @_; 566 my ($self, $cb) = @_;
284 567
285 $self->{on_drain} = $cb; 568 $self->{on_drain} = $cb;
286 569
287 $cb->($self) 570 $cb->($self)
288 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 571 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
289} 572}
290 573
291=item $handle->push_write ($data) 574=item $handle->push_write ($data)
292 575
293Queues the given scalar to be written. You can push as much data as you 576Queues the given scalar to be written. You can push as much data as you
297=cut 580=cut
298 581
299sub _drain_wbuf { 582sub _drain_wbuf {
300 my ($self) = @_; 583 my ($self) = @_;
301 584
302 unless ($self->{ww}) { 585 if (!$self->{_ww} && length $self->{wbuf}) {
586
303 Scalar::Util::weaken $self; 587 Scalar::Util::weaken $self;
588
304 my $cb = sub { 589 my $cb = sub {
305 my $len = syswrite $self->{fh}, $self->{wbuf}; 590 my $len = syswrite $self->{fh}, $self->{wbuf};
306 591
307 if ($len > 0) { 592 if (defined $len) {
308 substr $self->{wbuf}, 0, $len, ""; 593 substr $self->{wbuf}, 0, $len, "";
309 594
595 $self->{_activity} = AnyEvent->now;
596
310 $self->{on_drain}($self) 597 $self->{on_drain}($self)
311 if $self->{low_water_mark} >= length $self->{wbuf} 598 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
312 && $self->{on_drain}; 599 && $self->{on_drain};
313 600
314 delete $self->{ww} unless length $self->{wbuf}; 601 delete $self->{_ww} unless length $self->{wbuf};
315 } elsif ($! != EAGAIN && $! != EINTR) { 602 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
316 $self->error; 603 $self->_error ($!, 1);
317 } 604 }
318 }; 605 };
319 606
607 # try to write data immediately
608 $cb->() unless $self->{autocork};
609
610 # if still data left in wbuf, we need to poll
320 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 611 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
321 612 if length $self->{wbuf};
322 $cb->($self);
323 }; 613 };
614}
615
616our %WH;
617
618sub register_write_type($$) {
619 $WH{$_[0]} = $_[1];
324} 620}
325 621
326sub push_write { 622sub push_write {
327 my $self = shift; 623 my $self = shift;
328 624
625 if (@_ > 1) {
626 my $type = shift;
627
628 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
629 ->($self, @_);
630 }
631
329 if ($self->{filter_w}) { 632 if ($self->{tls}) {
330 $self->{filter_w}->($self, \$_[0]); 633 $self->{_tls_wbuf} .= $_[0];
634
635 &_dotls ($self);
331 } else { 636 } else {
332 $self->{wbuf} .= $_[0]; 637 $self->{wbuf} .= $_[0];
333 $self->_drain_wbuf; 638 $self->_drain_wbuf;
334 } 639 }
335} 640}
336 641
642=item $handle->push_write (type => @args)
643
644Instead of formatting your data yourself, you can also let this module do
645the job by specifying a type and type-specific arguments.
646
647Predefined types are (if you have ideas for additional types, feel free to
648drop by and tell us):
649
650=over 4
651
652=item netstring => $string
653
654Formats the given value as netstring
655(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
656
657=cut
658
659register_write_type netstring => sub {
660 my ($self, $string) = @_;
661
662 (length $string) . ":$string,"
663};
664
665=item packstring => $format, $data
666
667An octet string prefixed with an encoded length. The encoding C<$format>
668uses the same format as a Perl C<pack> format, but must specify a single
669integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
670optional C<!>, C<< < >> or C<< > >> modifier).
671
672=cut
673
674register_write_type packstring => sub {
675 my ($self, $format, $string) = @_;
676
677 pack "$format/a*", $string
678};
679
680=item json => $array_or_hashref
681
682Encodes the given hash or array reference into a JSON object. Unless you
683provide your own JSON object, this means it will be encoded to JSON text
684in UTF-8.
685
686JSON objects (and arrays) are self-delimiting, so you can write JSON at
687one end of a handle and read them at the other end without using any
688additional framing.
689
690The generated JSON text is guaranteed not to contain any newlines: While
691this module doesn't need delimiters after or between JSON texts to be
692able to read them, many other languages depend on that.
693
694A simple RPC protocol that interoperates easily with others is to send
695JSON arrays (or objects, although arrays are usually the better choice as
696they mimic how function argument passing works) and a newline after each
697JSON text:
698
699 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
700 $handle->push_write ("\012");
701
702An AnyEvent::Handle receiver would simply use the C<json> read type and
703rely on the fact that the newline will be skipped as leading whitespace:
704
705 $handle->push_read (json => sub { my $array = $_[1]; ... });
706
707Other languages could read single lines terminated by a newline and pass
708this line into their JSON decoder of choice.
709
710=cut
711
712register_write_type json => sub {
713 my ($self, $ref) = @_;
714
715 require JSON;
716
717 $self->{json} ? $self->{json}->encode ($ref)
718 : JSON::encode_json ($ref)
719};
720
721=item storable => $reference
722
723Freezes the given reference using L<Storable> and writes it to the
724handle. Uses the C<nfreeze> format.
725
726=cut
727
728register_write_type storable => sub {
729 my ($self, $ref) = @_;
730
731 require Storable;
732
733 pack "w/a*", Storable::nfreeze ($ref)
734};
735
736=back
737
738=item $handle->push_shutdown
739
740Sometimes you know you want to close the socket after writing your data
741before it was actually written. One way to do that is to replace your
742C<on_drain> handler by a callback that shuts down the socket (and set
743C<low_water_mark> to C<0>). This method is a shorthand for just that, and
744replaces the C<on_drain> callback with:
745
746 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
747
748This simply shuts down the write side and signals an EOF condition to the
749the peer.
750
751You can rely on the normal read queue and C<on_eof> handling
752afterwards. This is the cleanest way to close a connection.
753
754=cut
755
756sub push_shutdown {
757 my ($self) = @_;
758
759 delete $self->{low_water_mark};
760 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
761}
762
763=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
764
765This function (not method) lets you add your own types to C<push_write>.
766Whenever the given C<type> is used, C<push_write> will invoke the code
767reference with the handle object and the remaining arguments.
768
769The code reference is supposed to return a single octet string that will
770be appended to the write buffer.
771
772Note that this is a function, and all types registered this way will be
773global, so try to use unique names.
774
775=cut
776
337############################################################################# 777#############################################################################
338 778
339=back 779=back
340 780
341=head2 READ QUEUE 781=head2 READ QUEUE
347ways, the "simple" way, using only C<on_read> and the "complex" way, using 787ways, the "simple" way, using only C<on_read> and the "complex" way, using
348a queue. 788a queue.
349 789
350In the simple case, you just install an C<on_read> callback and whenever 790In the simple case, you just install an C<on_read> callback and whenever
351new data arrives, it will be called. You can then remove some data (if 791new data arrives, it will be called. You can then remove some data (if
352enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 792enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
353or not. 793leave the data there if you want to accumulate more (e.g. when only a
794partial message has been received so far).
354 795
355In the more complex case, you want to queue multiple callbacks. In this 796In the more complex case, you want to queue multiple callbacks. In this
356case, AnyEvent::Handle will call the first queued callback each time new 797case, AnyEvent::Handle will call the first queued callback each time new
357data arrives and removes it when it has done its job (see C<push_read>, 798data arrives (also the first time it is queued) and removes it when it has
358below). 799done its job (see C<push_read>, below).
359 800
360This way you can, for example, push three line-reads, followed by reading 801This way you can, for example, push three line-reads, followed by reading
361a chunk of data, and AnyEvent::Handle will execute them in order. 802a chunk of data, and AnyEvent::Handle will execute them in order.
362 803
363Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 804Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
364the specified number of bytes which give an XML datagram. 805the specified number of bytes which give an XML datagram.
365 806
366 # in the default state, expect some header bytes 807 # in the default state, expect some header bytes
367 $handle->on_read (sub { 808 $handle->on_read (sub {
368 # some data is here, now queue the length-header-read (4 octets) 809 # some data is here, now queue the length-header-read (4 octets)
369 shift->unshift_read_chunk (4, sub { 810 shift->unshift_read (chunk => 4, sub {
370 # header arrived, decode 811 # header arrived, decode
371 my $len = unpack "N", $_[1]; 812 my $len = unpack "N", $_[1];
372 813
373 # now read the payload 814 # now read the payload
374 shift->unshift_read_chunk ($len, sub { 815 shift->unshift_read (chunk => $len, sub {
375 my $xml = $_[1]; 816 my $xml = $_[1];
376 # handle xml 817 # handle xml
377 }); 818 });
378 }); 819 });
379 }); 820 });
380 821
381Example 2: Implement a client for a protocol that replies either with 822Example 2: Implement a client for a protocol that replies either with "OK"
382"OK" and another line or "ERROR" for one request, and 64 bytes for the 823and another line or "ERROR" for the first request that is sent, and 64
383second request. Due tot he availability of a full queue, we can just 824bytes for the second request. Due to the availability of a queue, we can
384pipeline sending both requests and manipulate the queue as necessary in 825just pipeline sending both requests and manipulate the queue as necessary
385the callbacks: 826in the callbacks.
386 827
387 # request one 828When the first callback is called and sees an "OK" response, it will
829C<unshift> another line-read. This line-read will be queued I<before> the
83064-byte chunk callback.
831
832 # request one, returns either "OK + extra line" or "ERROR"
388 $handle->push_write ("request 1\015\012"); 833 $handle->push_write ("request 1\015\012");
389 834
390 # we expect "ERROR" or "OK" as response, so push a line read 835 # we expect "ERROR" or "OK" as response, so push a line read
391 $handle->push_read_line (sub { 836 $handle->push_read (line => sub {
392 # if we got an "OK", we have to _prepend_ another line, 837 # if we got an "OK", we have to _prepend_ another line,
393 # so it will be read before the second request reads its 64 bytes 838 # so it will be read before the second request reads its 64 bytes
394 # which are already in the queue when this callback is called 839 # which are already in the queue when this callback is called
395 # we don't do this in case we got an error 840 # we don't do this in case we got an error
396 if ($_[1] eq "OK") { 841 if ($_[1] eq "OK") {
397 $_[0]->unshift_read_line (sub { 842 $_[0]->unshift_read (line => sub {
398 my $response = $_[1]; 843 my $response = $_[1];
399 ... 844 ...
400 }); 845 });
401 } 846 }
402 }); 847 });
403 848
404 # request two 849 # request two, simply returns 64 octets
405 $handle->push_write ("request 2\015\012"); 850 $handle->push_write ("request 2\015\012");
406 851
407 # simply read 64 bytes, always 852 # simply read 64 bytes, always
408 $handle->push_read_chunk (64, sub { 853 $handle->push_read (chunk => 64, sub {
409 my $response = $_[1]; 854 my $response = $_[1];
410 ... 855 ...
411 }); 856 });
412 857
413=over 4 858=over 4
414 859
415=cut 860=cut
416 861
417sub _drain_rbuf { 862sub _drain_rbuf {
418 my ($self) = @_; 863 my ($self) = @_;
864
865 local $self->{_in_drain} = 1;
419 866
420 if ( 867 if (
421 defined $self->{rbuf_max} 868 defined $self->{rbuf_max}
422 && $self->{rbuf_max} < length $self->{rbuf} 869 && $self->{rbuf_max} < length $self->{rbuf}
423 ) { 870 ) {
424 $! = &Errno::ENOSPC; return $self->error; 871 $self->_error (&Errno::ENOSPC, 1), return;
425 } 872 }
426 873
427 return if $self->{in_drain}; 874 while () {
428 local $self->{in_drain} = 1; 875 # we need to use a separate tls read buffer, as we must not receive data while
876 # we are draining the buffer, and this can only happen with TLS.
877 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
429 878
430 while (my $len = length $self->{rbuf}) { 879 my $len = length $self->{rbuf};
431 no strict 'refs'; 880
432 if (my $cb = shift @{ $self->{queue} }) { 881 if (my $cb = shift @{ $self->{_queue} }) {
433 if (!$cb->($self)) { 882 unless ($cb->($self)) {
434 if ($self->{eof}) { 883 if ($self->{_eof}) {
435 # no progress can be made (not enough data and no data forthcoming) 884 # no progress can be made (not enough data and no data forthcoming)
436 $! = &Errno::EPIPE; return $self->error; 885 $self->_error (&Errno::EPIPE, 1), return;
437 } 886 }
438 887
439 unshift @{ $self->{queue} }, $cb; 888 unshift @{ $self->{_queue} }, $cb;
440 return; 889 last;
441 } 890 }
442 } elsif ($self->{on_read}) { 891 } elsif ($self->{on_read}) {
892 last unless $len;
893
443 $self->{on_read}($self); 894 $self->{on_read}($self);
444 895
445 if ( 896 if (
446 $self->{eof} # if no further data will arrive
447 && $len == length $self->{rbuf} # and no data has been consumed 897 $len == length $self->{rbuf} # if no data has been consumed
448 && !@{ $self->{queue} } # and the queue is still empty 898 && !@{ $self->{_queue} } # and the queue is still empty
449 && $self->{on_read} # and we still want to read data 899 && $self->{on_read} # but we still have on_read
450 ) { 900 ) {
901 # no further data will arrive
451 # then no progress can be made 902 # so no progress can be made
452 $! = &Errno::EPIPE; return $self->error; 903 $self->_error (&Errno::EPIPE, 1), return
904 if $self->{_eof};
905
906 last; # more data might arrive
453 } 907 }
454 } else { 908 } else {
455 # read side becomes idle 909 # read side becomes idle
456 delete $self->{rw}; 910 delete $self->{_rw} unless $self->{tls};
457 return; 911 last;
458 } 912 }
459 } 913 }
460 914
461 if ($self->{eof}) { 915 if ($self->{_eof}) {
462 $self->_shutdown; 916 if ($self->{on_eof}) {
463 $self->{on_eof}($self) 917 $self->{on_eof}($self)
464 if $self->{on_eof}; 918 } else {
919 $self->_error (0, 1, "Unexpected end-of-file");
920 }
921 }
922
923 # may need to restart read watcher
924 unless ($self->{_rw}) {
925 $self->start_read
926 if $self->{on_read} || @{ $self->{_queue} };
465 } 927 }
466} 928}
467 929
468=item $handle->on_read ($cb) 930=item $handle->on_read ($cb)
469 931
475 937
476sub on_read { 938sub on_read {
477 my ($self, $cb) = @_; 939 my ($self, $cb) = @_;
478 940
479 $self->{on_read} = $cb; 941 $self->{on_read} = $cb;
942 $self->_drain_rbuf if $cb && !$self->{_in_drain};
480} 943}
481 944
482=item $handle->rbuf 945=item $handle->rbuf
483 946
484Returns the read buffer (as a modifiable lvalue). 947Returns the read buffer (as a modifiable lvalue).
485 948
486You can access the read buffer directly as the C<< ->{rbuf} >> member, if 949You can access the read buffer directly as the C<< ->{rbuf} >>
487you want. 950member, if you want. However, the only operation allowed on the
951read buffer (apart from looking at it) is removing data from its
952beginning. Otherwise modifying or appending to it is not allowed and will
953lead to hard-to-track-down bugs.
488 954
489NOTE: The read buffer should only be used or modified if the C<on_read>, 955NOTE: The read buffer should only be used or modified if the C<on_read>,
490C<push_read> or C<unshift_read> methods are used. The other read methods 956C<push_read> or C<unshift_read> methods are used. The other read methods
491automatically manage the read buffer. 957automatically manage the read buffer.
492 958
515interested in (which can be none at all) and return a true value. After returning 981interested in (which can be none at all) and return a true value. After returning
516true, it will be removed from the queue. 982true, it will be removed from the queue.
517 983
518=cut 984=cut
519 985
986our %RH;
987
988sub register_read_type($$) {
989 $RH{$_[0]} = $_[1];
990}
991
520sub push_read { 992sub push_read {
521 my $self = shift; 993 my $self = shift;
522 my $cb = pop; 994 my $cb = pop;
523 995
524 if (@_) { 996 if (@_) {
526 998
527 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 999 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
528 ->($self, $cb, @_); 1000 ->($self, $cb, @_);
529 } 1001 }
530 1002
531 push @{ $self->{queue} }, $cb; 1003 push @{ $self->{_queue} }, $cb;
532 $self->_drain_rbuf; 1004 $self->_drain_rbuf unless $self->{_in_drain};
533} 1005}
534 1006
535sub unshift_read { 1007sub unshift_read {
536 my $self = shift; 1008 my $self = shift;
537 my $cb = pop; 1009 my $cb = pop;
542 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1014 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
543 ->($self, $cb, @_); 1015 ->($self, $cb, @_);
544 } 1016 }
545 1017
546 1018
547 unshift @{ $self->{queue} }, $cb; 1019 unshift @{ $self->{_queue} }, $cb;
548 $self->_drain_rbuf; 1020 $self->_drain_rbuf unless $self->{_in_drain};
549} 1021}
550 1022
551=item $handle->push_read (type => @args, $cb) 1023=item $handle->push_read (type => @args, $cb)
552 1024
553=item $handle->unshift_read (type => @args, $cb) 1025=item $handle->unshift_read (type => @args, $cb)
554 1026
555Instead of providing a callback that parses the data itself you can chose 1027Instead of providing a callback that parses the data itself you can chose
556between a number of predefined parsing formats, for chunks of data, lines 1028between a number of predefined parsing formats, for chunks of data, lines
557etc. 1029etc.
558 1030
559The types currently supported are: 1031Predefined types are (if you have ideas for additional types, feel free to
1032drop by and tell us):
560 1033
561=over 4 1034=over 4
562 1035
563=item chunk => $octets, $cb->($self, $data) 1036=item chunk => $octets, $cb->($handle, $data)
564 1037
565Invoke the callback only once C<$octets> bytes have been read. Pass the 1038Invoke the callback only once C<$octets> bytes have been read. Pass the
566data read to the callback. The callback will never be called with less 1039data read to the callback. The callback will never be called with less
567data. 1040data.
568 1041
582 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1055 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
583 1 1056 1
584 } 1057 }
585}; 1058};
586 1059
587# compatibility with older API
588sub push_read_chunk {
589 $_[0]->push_read (chunk => $_[1], $_[2]);
590}
591
592sub unshift_read_chunk {
593 $_[0]->unshift_read (chunk => $_[1], $_[2]);
594}
595
596=item line => [$eol, ]$cb->($self, $line, $eol) 1060=item line => [$eol, ]$cb->($handle, $line, $eol)
597 1061
598The callback will be called only once a full line (including the end of 1062The callback will be called only once a full line (including the end of
599line marker, C<$eol>) has been read. This line (excluding the end of line 1063line marker, C<$eol>) has been read. This line (excluding the end of line
600marker) will be passed to the callback as second argument (C<$line>), and 1064marker) will be passed to the callback as second argument (C<$line>), and
601the end of line marker as the third argument (C<$eol>). 1065the end of line marker as the third argument (C<$eol>).
615=cut 1079=cut
616 1080
617register_read_type line => sub { 1081register_read_type line => sub {
618 my ($self, $cb, $eol) = @_; 1082 my ($self, $cb, $eol) = @_;
619 1083
620 $eol = qr|(\015?\012)| if @_ < 3; 1084 if (@_ < 3) {
1085 # this is more than twice as fast as the generic code below
1086 sub {
1087 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1088
1089 $cb->($_[0], $1, $2);
1090 1
1091 }
1092 } else {
621 $eol = quotemeta $eol unless ref $eol; 1093 $eol = quotemeta $eol unless ref $eol;
622 $eol = qr|^(.*?)($eol)|s; 1094 $eol = qr|^(.*?)($eol)|s;
1095
1096 sub {
1097 $_[0]{rbuf} =~ s/$eol// or return;
1098
1099 $cb->($_[0], $1, $2);
1100 1
1101 }
1102 }
1103};
1104
1105=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
1106
1107Makes a regex match against the regex object C<$accept> and returns
1108everything up to and including the match.
1109
1110Example: read a single line terminated by '\n'.
1111
1112 $handle->push_read (regex => qr<\n>, sub { ... });
1113
1114If C<$reject> is given and not undef, then it determines when the data is
1115to be rejected: it is matched against the data when the C<$accept> regex
1116does not match and generates an C<EBADMSG> error when it matches. This is
1117useful to quickly reject wrong data (to avoid waiting for a timeout or a
1118receive buffer overflow).
1119
1120Example: expect a single decimal number followed by whitespace, reject
1121anything else (not the use of an anchor).
1122
1123 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1124
1125If C<$skip> is given and not C<undef>, then it will be matched against
1126the receive buffer when neither C<$accept> nor C<$reject> match,
1127and everything preceding and including the match will be accepted
1128unconditionally. This is useful to skip large amounts of data that you
1129know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1130have to start matching from the beginning. This is purely an optimisation
1131and is usually worth only when you expect more than a few kilobytes.
1132
1133Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1134expect the header to be very large (it isn't in practise, but...), we use
1135a skip regex to skip initial portions. The skip regex is tricky in that
1136it only accepts something not ending in either \015 or \012, as these are
1137required for the accept regex.
1138
1139 $handle->push_read (regex =>
1140 qr<\015\012\015\012>,
1141 undef, # no reject
1142 qr<^.*[^\015\012]>,
1143 sub { ... });
1144
1145=cut
1146
1147register_read_type regex => sub {
1148 my ($self, $cb, $accept, $reject, $skip) = @_;
1149
1150 my $data;
1151 my $rbuf = \$self->{rbuf};
623 1152
624 sub { 1153 sub {
625 $_[0]{rbuf} =~ s/$eol// or return; 1154 # accept
1155 if ($$rbuf =~ $accept) {
1156 $data .= substr $$rbuf, 0, $+[0], "";
1157 $cb->($self, $data);
1158 return 1;
1159 }
1160
1161 # reject
1162 if ($reject && $$rbuf =~ $reject) {
1163 $self->_error (&Errno::EBADMSG);
1164 }
626 1165
627 $cb->($_[0], $1, $2); 1166 # skip
1167 if ($skip && $$rbuf =~ $skip) {
1168 $data .= substr $$rbuf, 0, $+[0], "";
1169 }
1170
1171 ()
1172 }
1173};
1174
1175=item netstring => $cb->($handle, $string)
1176
1177A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1178
1179Throws an error with C<$!> set to EBADMSG on format violations.
1180
1181=cut
1182
1183register_read_type netstring => sub {
1184 my ($self, $cb) = @_;
1185
1186 sub {
1187 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1188 if ($_[0]{rbuf} =~ /[^0-9]/) {
1189 $self->_error (&Errno::EBADMSG);
1190 }
1191 return;
1192 }
1193
1194 my $len = $1;
1195
1196 $self->unshift_read (chunk => $len, sub {
1197 my $string = $_[1];
1198 $_[0]->unshift_read (chunk => 1, sub {
1199 if ($_[1] eq ",") {
1200 $cb->($_[0], $string);
1201 } else {
1202 $self->_error (&Errno::EBADMSG);
1203 }
1204 });
1205 });
1206
628 1 1207 1
629 } 1208 }
630}; 1209};
631 1210
632# compatibility with older API 1211=item packstring => $format, $cb->($handle, $string)
633sub push_read_line {
634 my $self = shift;
635 $self->push_read (line => @_);
636}
637 1212
638sub unshift_read_line { 1213An octet string prefixed with an encoded length. The encoding C<$format>
639 my $self = shift; 1214uses the same format as a Perl C<pack> format, but must specify a single
640 $self->unshift_read (line => @_); 1215integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
641} 1216optional C<!>, C<< < >> or C<< > >> modifier).
1217
1218For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1219EPP uses a prefix of C<N> (4 octtes).
1220
1221Example: read a block of data prefixed by its length in BER-encoded
1222format (very efficient).
1223
1224 $handle->push_read (packstring => "w", sub {
1225 my ($handle, $data) = @_;
1226 });
1227
1228=cut
1229
1230register_read_type packstring => sub {
1231 my ($self, $cb, $format) = @_;
1232
1233 sub {
1234 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1235 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1236 or return;
1237
1238 $format = length pack $format, $len;
1239
1240 # bypass unshift if we already have the remaining chunk
1241 if ($format + $len <= length $_[0]{rbuf}) {
1242 my $data = substr $_[0]{rbuf}, $format, $len;
1243 substr $_[0]{rbuf}, 0, $format + $len, "";
1244 $cb->($_[0], $data);
1245 } else {
1246 # remove prefix
1247 substr $_[0]{rbuf}, 0, $format, "";
1248
1249 # read remaining chunk
1250 $_[0]->unshift_read (chunk => $len, $cb);
1251 }
1252
1253 1
1254 }
1255};
1256
1257=item json => $cb->($handle, $hash_or_arrayref)
1258
1259Reads a JSON object or array, decodes it and passes it to the
1260callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1261
1262If a C<json> object was passed to the constructor, then that will be used
1263for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1264
1265This read type uses the incremental parser available with JSON version
12662.09 (and JSON::XS version 2.2) and above. You have to provide a
1267dependency on your own: this module will load the JSON module, but
1268AnyEvent does not depend on it itself.
1269
1270Since JSON texts are fully self-delimiting, the C<json> read and write
1271types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1272the C<json> write type description, above, for an actual example.
1273
1274=cut
1275
1276register_read_type json => sub {
1277 my ($self, $cb) = @_;
1278
1279 my $json = $self->{json} ||=
1280 eval { require JSON::XS; JSON::XS->new->utf8 }
1281 || do { require JSON; JSON->new->utf8 };
1282
1283 my $data;
1284 my $rbuf = \$self->{rbuf};
1285
1286 sub {
1287 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1288
1289 if ($ref) {
1290 $self->{rbuf} = $json->incr_text;
1291 $json->incr_text = "";
1292 $cb->($self, $ref);
1293
1294 1
1295 } elsif ($@) {
1296 # error case
1297 $json->incr_skip;
1298
1299 $self->{rbuf} = $json->incr_text;
1300 $json->incr_text = "";
1301
1302 $self->_error (&Errno::EBADMSG);
1303
1304 ()
1305 } else {
1306 $self->{rbuf} = "";
1307
1308 ()
1309 }
1310 }
1311};
1312
1313=item storable => $cb->($handle, $ref)
1314
1315Deserialises a L<Storable> frozen representation as written by the
1316C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1317data).
1318
1319Raises C<EBADMSG> error if the data could not be decoded.
1320
1321=cut
1322
1323register_read_type storable => sub {
1324 my ($self, $cb) = @_;
1325
1326 require Storable;
1327
1328 sub {
1329 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1330 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1331 or return;
1332
1333 my $format = length pack "w", $len;
1334
1335 # bypass unshift if we already have the remaining chunk
1336 if ($format + $len <= length $_[0]{rbuf}) {
1337 my $data = substr $_[0]{rbuf}, $format, $len;
1338 substr $_[0]{rbuf}, 0, $format + $len, "";
1339 $cb->($_[0], Storable::thaw ($data));
1340 } else {
1341 # remove prefix
1342 substr $_[0]{rbuf}, 0, $format, "";
1343
1344 # read remaining chunk
1345 $_[0]->unshift_read (chunk => $len, sub {
1346 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1347 $cb->($_[0], $ref);
1348 } else {
1349 $self->_error (&Errno::EBADMSG);
1350 }
1351 });
1352 }
1353
1354 1
1355 }
1356};
642 1357
643=back 1358=back
644 1359
1360=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
1361
1362This function (not method) lets you add your own types to C<push_read>.
1363
1364Whenever the given C<type> is used, C<push_read> will invoke the code
1365reference with the handle object, the callback and the remaining
1366arguments.
1367
1368The code reference is supposed to return a callback (usually a closure)
1369that works as a plain read callback (see C<< ->push_read ($cb) >>).
1370
1371It should invoke the passed callback when it is done reading (remember to
1372pass C<$handle> as first argument as all other callbacks do that).
1373
1374Note that this is a function, and all types registered this way will be
1375global, so try to use unique names.
1376
1377For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
1378search for C<register_read_type>)).
1379
645=item $handle->stop_read 1380=item $handle->stop_read
646 1381
647=item $handle->start_read 1382=item $handle->start_read
648 1383
649In rare cases you actually do not want to read anything from the 1384In rare cases you actually do not want to read anything from the
650socket. In this case you can call C<stop_read>. Neither C<on_read> no 1385socket. In this case you can call C<stop_read>. Neither C<on_read> nor
651any queued callbacks will be executed then. To start reading again, call 1386any queued callbacks will be executed then. To start reading again, call
652C<start_read>. 1387C<start_read>.
653 1388
1389Note that AnyEvent::Handle will automatically C<start_read> for you when
1390you change the C<on_read> callback or push/unshift a read callback, and it
1391will automatically C<stop_read> for you when neither C<on_read> is set nor
1392there are any read requests in the queue.
1393
1394These methods will have no effect when in TLS mode (as TLS doesn't support
1395half-duplex connections).
1396
654=cut 1397=cut
655 1398
656sub stop_read { 1399sub stop_read {
657 my ($self) = @_; 1400 my ($self) = @_;
658 1401
659 delete $self->{rw}; 1402 delete $self->{_rw} unless $self->{tls};
660} 1403}
661 1404
662sub start_read { 1405sub start_read {
663 my ($self) = @_; 1406 my ($self) = @_;
664 1407
665 unless ($self->{rw} || $self->{eof}) { 1408 unless ($self->{_rw} || $self->{_eof}) {
666 Scalar::Util::weaken $self; 1409 Scalar::Util::weaken $self;
667 1410
668 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1411 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
669 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1412 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
670 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1413 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
671 1414
672 if ($len > 0) { 1415 if ($len > 0) {
673 $self->{filter_r} 1416 $self->{_activity} = AnyEvent->now;
674 ? $self->{filter_r}->($self, $rbuf) 1417
675 : $self->_drain_rbuf; 1418 if ($self->{tls}) {
1419 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1420
1421 &_dotls ($self);
1422 } else {
1423 $self->_drain_rbuf unless $self->{_in_drain};
1424 }
676 1425
677 } elsif (defined $len) { 1426 } elsif (defined $len) {
678 delete $self->{rw}; 1427 delete $self->{_rw};
679 $self->{eof} = 1; 1428 $self->{_eof} = 1;
680 $self->_drain_rbuf; 1429 $self->_drain_rbuf unless $self->{_in_drain};
681 1430
682 } elsif ($! != EAGAIN && $! != EINTR) { 1431 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
683 return $self->error; 1432 return $self->_error ($!, 1);
684 } 1433 }
685 }); 1434 });
686 } 1435 }
687} 1436}
688 1437
1438our $ERROR_SYSCALL;
1439our $ERROR_WANT_READ;
1440
1441sub _tls_error {
1442 my ($self, $err) = @_;
1443
1444 return $self->_error ($!, 1)
1445 if $err == Net::SSLeay::ERROR_SYSCALL ();
1446
1447 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1448
1449 # reduce error string to look less scary
1450 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1451
1452 if ($self->{_on_starttls}) {
1453 (delete $self->{_on_starttls})->($self, undef, $err);
1454 &_freetls;
1455 } else {
1456 &_freetls;
1457 $self->_error (&Errno::EPROTO, 1, $err);
1458 }
1459}
1460
1461# poll the write BIO and send the data if applicable
1462# also decode read data if possible
1463# this is basiclaly our TLS state machine
1464# more efficient implementations are possible with openssl,
1465# but not with the buggy and incomplete Net::SSLeay.
689sub _dotls { 1466sub _dotls {
690 my ($self) = @_; 1467 my ($self) = @_;
691 1468
1469 my $tmp;
1470
692 if (length $self->{tls_wbuf}) { 1471 if (length $self->{_tls_wbuf}) {
693 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1472 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
694 substr $self->{tls_wbuf}, 0, $len, ""; 1473 substr $self->{_tls_wbuf}, 0, $tmp, "";
695 } 1474 }
696 }
697 1475
1476 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1477 return $self->_tls_error ($tmp)
1478 if $tmp != $ERROR_WANT_READ
1479 && ($tmp != $ERROR_SYSCALL || $!);
1480 }
1481
698 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1482 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1483 unless (length $tmp) {
1484 $self->{_on_starttls}
1485 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1486 &_freetls;
1487
1488 if ($self->{on_stoptls}) {
1489 $self->{on_stoptls}($self);
1490 return;
1491 } else {
1492 # let's treat SSL-eof as we treat normal EOF
1493 delete $self->{_rw};
1494 $self->{_eof} = 1;
1495 }
1496 }
1497
1498 $self->{_tls_rbuf} .= $tmp;
1499 $self->_drain_rbuf unless $self->{_in_drain};
1500 $self->{tls} or return; # tls session might have gone away in callback
1501 }
1502
1503 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1504 return $self->_tls_error ($tmp)
1505 if $tmp != $ERROR_WANT_READ
1506 && ($tmp != $ERROR_SYSCALL || $!);
1507
1508 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
699 $self->{wbuf} .= $buf; 1509 $self->{wbuf} .= $tmp;
700 $self->_drain_wbuf; 1510 $self->_drain_wbuf;
701 } 1511 }
702 1512
703 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) { 1513 $self->{_on_starttls}
704 $self->{rbuf} .= $buf; 1514 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
705 $self->_drain_rbuf; 1515 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
706 }
707
708 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
709
710 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
711 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
712 $self->error;
713 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
714 $! = &Errno::EIO;
715 $self->error;
716 }
717
718 # all others are fine for our purposes
719 }
720} 1516}
721 1517
722=item $handle->starttls ($tls[, $tls_ctx]) 1518=item $handle->starttls ($tls[, $tls_ctx])
723 1519
724Instead of starting TLS negotiation immediately when the AnyEvent::Handle 1520Instead of starting TLS negotiation immediately when the AnyEvent::Handle
726C<starttls>. 1522C<starttls>.
727 1523
728The first argument is the same as the C<tls> constructor argument (either 1524The first argument is the same as the C<tls> constructor argument (either
729C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1525C<"connect">, C<"accept"> or an existing Net::SSLeay object).
730 1526
731The second argument is the optional C<Net::SSLeay::CTX> object that is 1527The second argument is the optional C<AnyEvent::TLS> object that is used
732used when AnyEvent::Handle has to create its own TLS connection object. 1528when AnyEvent::Handle has to create its own TLS connection object, or
1529a hash reference with C<< key => value >> pairs that will be used to
1530construct a new context.
733 1531
734=cut 1532The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1533context in C<< $handle->{tls_ctx} >> after this call and can be used or
1534changed to your liking. Note that the handshake might have already started
1535when this function returns.
735 1536
736# TODO: maybe document... 1537If it an error to start a TLS handshake more than once per
1538AnyEvent::Handle object (this is due to bugs in OpenSSL).
1539
1540=cut
1541
1542our %TLS_CACHE; #TODO not yet documented, should we?
1543
737sub starttls { 1544sub starttls {
738 my ($self, $ssl, $ctx) = @_; 1545 my ($self, $ssl, $ctx) = @_;
739 1546
740 $self->stoptls; 1547 require Net::SSLeay;
741 1548
742 if ($ssl eq "accept") { 1549 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
743 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1550 if $self->{tls};
744 Net::SSLeay::set_accept_state ($ssl); 1551
745 } elsif ($ssl eq "connect") { 1552 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
746 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1553 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
747 Net::SSLeay::set_connect_state ($ssl); 1554
1555 $ctx ||= $self->{tls_ctx};
1556
1557 if ("HASH" eq ref $ctx) {
1558 require AnyEvent::TLS;
1559
1560 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1561
1562 if ($ctx->{cache}) {
1563 my $key = $ctx+0;
1564 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1565 } else {
1566 $ctx = new AnyEvent::TLS %$ctx;
1567 }
1568 }
748 } 1569
749 1570 $self->{tls_ctx} = $ctx || TLS_CTX ();
750 $self->{tls} = $ssl; 1571 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername});
751 1572
752 # basically, this is deep magic (because SSL_read should have the same issues) 1573 # basically, this is deep magic (because SSL_read should have the same issues)
753 # but the openssl maintainers basically said: "trust us, it just works". 1574 # but the openssl maintainers basically said: "trust us, it just works".
754 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1575 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
755 # and mismaintained ssleay-module doesn't even offer them). 1576 # and mismaintained ssleay-module doesn't even offer them).
756 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1577 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1578 #
1579 # in short: this is a mess.
1580 #
1581 # note that we do not try to keep the length constant between writes as we are required to do.
1582 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1583 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1584 # have identity issues in that area.
757 Net::SSLeay::CTX_set_mode ($self->{tls}, 1585# Net::SSLeay::CTX_set_mode ($ssl,
758 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1586# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
759 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1587# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1588 Net::SSLeay::CTX_set_mode ($ssl, 1|2);
760 1589
761 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1590 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
762 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1591 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
763 1592
764 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1593 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
765 1594
766 $self->{filter_w} = sub { 1595 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
767 $_[0]{tls_wbuf} .= ${$_[1]}; 1596 if $self->{on_starttls};
768 &_dotls; 1597
769 }; 1598 &_dotls; # need to trigger the initial handshake
770 $self->{filter_r} = sub { 1599 $self->start_read; # make sure we actually do read
771 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
772 &_dotls;
773 };
774} 1600}
775 1601
776=item $handle->stoptls 1602=item $handle->stoptls
777 1603
778Destroys the SSL connection, if any. Partial read or write data will be 1604Shuts down the SSL connection - this makes a proper EOF handshake by
779lost. 1605sending a close notify to the other side, but since OpenSSL doesn't
1606support non-blocking shut downs, it is not possible to re-use the stream
1607afterwards.
780 1608
781=cut 1609=cut
782 1610
783sub stoptls { 1611sub stoptls {
784 my ($self) = @_; 1612 my ($self) = @_;
785 1613
786 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1614 if ($self->{tls}) {
787 delete $self->{tls_rbio}; 1615 Net::SSLeay::shutdown ($self->{tls});
788 delete $self->{tls_wbio}; 1616
789 delete $self->{tls_wbuf}; 1617 &_dotls;
790 delete $self->{filter_r}; 1618
791 delete $self->{filter_w}; 1619# # we don't give a shit. no, we do, but we can't. no...#d#
1620# # we, we... have to use openssl :/#d#
1621# &_freetls;#d#
1622 }
1623}
1624
1625sub _freetls {
1626 my ($self) = @_;
1627
1628 return unless $self->{tls};
1629
1630 $self->{tls_ctx}->_put_session (delete $self->{tls});
1631
1632 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
792} 1633}
793 1634
794sub DESTROY { 1635sub DESTROY {
795 my $self = shift; 1636 my ($self) = @_;
796 1637
797 $self->stoptls; 1638 &_freetls;
1639
1640 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1641
1642 if ($linger && length $self->{wbuf}) {
1643 my $fh = delete $self->{fh};
1644 my $wbuf = delete $self->{wbuf};
1645
1646 my @linger;
1647
1648 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1649 my $len = syswrite $fh, $wbuf, length $wbuf;
1650
1651 if ($len > 0) {
1652 substr $wbuf, 0, $len, "";
1653 } else {
1654 @linger = (); # end
1655 }
1656 });
1657 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1658 @linger = ();
1659 });
1660 }
1661}
1662
1663=item $handle->destroy
1664
1665Shuts down the handle object as much as possible - this call ensures that
1666no further callbacks will be invoked and as many resources as possible
1667will be freed. You must not call any methods on the object afterwards.
1668
1669Normally, you can just "forget" any references to an AnyEvent::Handle
1670object and it will simply shut down. This works in fatal error and EOF
1671callbacks, as well as code outside. It does I<NOT> work in a read or write
1672callback, so when you want to destroy the AnyEvent::Handle object from
1673within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1674that case.
1675
1676The handle might still linger in the background and write out remaining
1677data, as specified by the C<linger> option, however.
1678
1679=cut
1680
1681sub destroy {
1682 my ($self) = @_;
1683
1684 $self->DESTROY;
1685 %$self = ();
798} 1686}
799 1687
800=item AnyEvent::Handle::TLS_CTX 1688=item AnyEvent::Handle::TLS_CTX
801 1689
802This function creates and returns the Net::SSLeay::CTX object used by 1690This function creates and returns the AnyEvent::TLS object used by default
803default for TLS mode. 1691for TLS mode.
804 1692
805The context is created like this: 1693The context is created by calling L<AnyEvent::TLS> without any arguments.
806
807 Net::SSLeay::load_error_strings;
808 Net::SSLeay::SSLeay_add_ssl_algorithms;
809 Net::SSLeay::randomize;
810
811 my $CTX = Net::SSLeay::CTX_new;
812
813 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
814 1694
815=cut 1695=cut
816 1696
817our $TLS_CTX; 1697our $TLS_CTX;
818 1698
819sub TLS_CTX() { 1699sub TLS_CTX() {
820 $TLS_CTX || do { 1700 $TLS_CTX ||= do {
821 require Net::SSLeay; 1701 require AnyEvent::TLS;
822 1702
823 Net::SSLeay::load_error_strings (); 1703 new AnyEvent::TLS
824 Net::SSLeay::SSLeay_add_ssl_algorithms ();
825 Net::SSLeay::randomize ();
826
827 $TLS_CTX = Net::SSLeay::CTX_new ();
828
829 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
830
831 $TLS_CTX
832 } 1704 }
833} 1705}
834 1706
835=back 1707=back
836 1708
1709
1710=head1 NONFREQUENTLY ASKED QUESTIONS
1711
1712=over 4
1713
1714=item I C<undef> the AnyEvent::Handle reference inside my callback and
1715still get further invocations!
1716
1717That's because AnyEvent::Handle keeps a reference to itself when handling
1718read or write callbacks.
1719
1720It is only safe to "forget" the reference inside EOF or error callbacks,
1721from within all other callbacks, you need to explicitly call the C<<
1722->destroy >> method.
1723
1724=item I get different callback invocations in TLS mode/Why can't I pause
1725reading?
1726
1727Unlike, say, TCP, TLS connections do not consist of two independent
1728communication channels, one for each direction. Or put differently. The
1729read and write directions are not independent of each other: you cannot
1730write data unless you are also prepared to read, and vice versa.
1731
1732This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1733callback invocations when you are not expecting any read data - the reason
1734is that AnyEvent::Handle always reads in TLS mode.
1735
1736During the connection, you have to make sure that you always have a
1737non-empty read-queue, or an C<on_read> watcher. At the end of the
1738connection (or when you no longer want to use it) you can call the
1739C<destroy> method.
1740
1741=item How do I read data until the other side closes the connection?
1742
1743If you just want to read your data into a perl scalar, the easiest way
1744to achieve this is by setting an C<on_read> callback that does nothing,
1745clearing the C<on_eof> callback and in the C<on_error> callback, the data
1746will be in C<$_[0]{rbuf}>:
1747
1748 $handle->on_read (sub { });
1749 $handle->on_eof (undef);
1750 $handle->on_error (sub {
1751 my $data = delete $_[0]{rbuf};
1752 undef $handle;
1753 });
1754
1755The reason to use C<on_error> is that TCP connections, due to latencies
1756and packets loss, might get closed quite violently with an error, when in
1757fact, all data has been received.
1758
1759It is usually better to use acknowledgements when transferring data,
1760to make sure the other side hasn't just died and you got the data
1761intact. This is also one reason why so many internet protocols have an
1762explicit QUIT command.
1763
1764=item I don't want to destroy the handle too early - how do I wait until
1765all data has been written?
1766
1767After writing your last bits of data, set the C<on_drain> callback
1768and destroy the handle in there - with the default setting of
1769C<low_water_mark> this will be called precisely when all data has been
1770written to the socket:
1771
1772 $handle->push_write (...);
1773 $handle->on_drain (sub {
1774 warn "all data submitted to the kernel\n";
1775 undef $handle;
1776 });
1777
1778If you just want to queue some data and then signal EOF to the other side,
1779consider using C<< ->push_shutdown >> instead.
1780
1781=item I want to contact a TLS/SSL server, I don't care about security.
1782
1783If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
1784simply connect to it and then create the AnyEvent::Handle with the C<tls>
1785parameter:
1786
1787 tcp_connect $host, $port, sub {
1788 my ($fh) = @_;
1789
1790 my $handle = new AnyEvent::Handle
1791 fh => $fh,
1792 tls => "connect",
1793 on_error => sub { ... };
1794
1795 $handle->push_write (...);
1796 };
1797
1798=item I want to contact a TLS/SSL server, I do care about security.
1799
1800Then you should additionally enable certificate verification, including
1801peername verification, if the protocol you use supports it (see
1802L<AnyEvent::TLS>, C<verify_peername>).
1803
1804E.g. for HTTPS:
1805
1806 tcp_connect $host, $port, sub {
1807 my ($fh) = @_;
1808
1809 my $handle = new AnyEvent::Handle
1810 fh => $fh,
1811 peername => $host,
1812 tls => "connect",
1813 tls_ctx => { verify => 1, verify_peername => "https" },
1814 ...
1815
1816Note that you must specify the hostname you connected to (or whatever
1817"peername" the protocol needs) as the C<peername> argument, otherwise no
1818peername verification will be done.
1819
1820The above will use the system-dependent default set of trusted CA
1821certificates. If you want to check against a specific CA, add the
1822C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1823
1824 tls_ctx => {
1825 verify => 1,
1826 verify_peername => "https",
1827 ca_file => "my-ca-cert.pem",
1828 },
1829
1830=item I want to create a TLS/SSL server, how do I do that?
1831
1832Well, you first need to get a server certificate and key. You have
1833three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1834self-signed certificate (cheap. check the search engine of your choice,
1835there are many tutorials on the net) or c) make your own CA (tinyca2 is a
1836nice program for that purpose).
1837
1838Then create a file with your private key (in PEM format, see
1839L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
1840file should then look like this:
1841
1842 -----BEGIN RSA PRIVATE KEY-----
1843 ...header data
1844 ... lots of base64'y-stuff
1845 -----END RSA PRIVATE KEY-----
1846
1847 -----BEGIN CERTIFICATE-----
1848 ... lots of base64'y-stuff
1849 -----END CERTIFICATE-----
1850
1851The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
1852specify this file as C<cert_file>:
1853
1854 tcp_server undef, $port, sub {
1855 my ($fh) = @_;
1856
1857 my $handle = new AnyEvent::Handle
1858 fh => $fh,
1859 tls => "accept",
1860 tls_ctx => { cert_file => "my-server-keycert.pem" },
1861 ...
1862
1863When you have intermediate CA certificates that your clients might not
1864know about, just append them to the C<cert_file>.
1865
1866=back
1867
1868
1869=head1 SUBCLASSING AnyEvent::Handle
1870
1871In many cases, you might want to subclass AnyEvent::Handle.
1872
1873To make this easier, a given version of AnyEvent::Handle uses these
1874conventions:
1875
1876=over 4
1877
1878=item * all constructor arguments become object members.
1879
1880At least initially, when you pass a C<tls>-argument to the constructor it
1881will end up in C<< $handle->{tls} >>. Those members might be changed or
1882mutated later on (for example C<tls> will hold the TLS connection object).
1883
1884=item * other object member names are prefixed with an C<_>.
1885
1886All object members not explicitly documented (internal use) are prefixed
1887with an underscore character, so the remaining non-C<_>-namespace is free
1888for use for subclasses.
1889
1890=item * all members not documented here and not prefixed with an underscore
1891are free to use in subclasses.
1892
1893Of course, new versions of AnyEvent::Handle may introduce more "public"
1894member variables, but thats just life, at least it is documented.
1895
1896=back
1897
837=head1 AUTHOR 1898=head1 AUTHOR
838 1899
839Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1900Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
840 1901
841=cut 1902=cut

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