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Revision 1.64 by root, Fri Jun 6 11:01:17 2008 UTC vs.
Revision 1.109 by root, Wed Jan 14 02:03:43 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 qw(WSAEWOULDBLOCK); 7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util (); 8use Scalar::Util ();
9use Carp (); 9use Carp ();
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
17=cut 17=cut
18 18
19our $VERSION = 4.15; 19our $VERSION = 4.331;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This 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
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means 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
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called when an end-of-file condition is detcted, 84Set the callback to be called when an end-of-file condition is detected,
81i.e. in the case of a socket, when the other side has closed the 85i.e. in the case of a socket, when the other side has closed the
82connection cleanly. 86connection cleanly.
83 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
84While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
85otherwise 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
86waiting for data. 95waiting for data.
96
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>.
87 99
88=item on_error => $cb->($handle, $fatal) 100=item on_error => $cb->($handle, $fatal)
89 101
90This is the error callback, which is called when, well, some error 102This is the error callback, which is called when, well, some error
91occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
92connect or a read error. 104connect or a read error.
93 105
94Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
95fatal errors the handle object will be shut down and will not be 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
96usable. Non-fatal errors can be retried by simply returning, but it is 112Non-fatal errors can be retried by simply returning, but it is recommended
97recommended to simply ignore this parameter and instead abondon the handle 113to simply ignore this parameter and instead abondon the handle object
98object when this callback is invoked. 114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
99 116
100On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
101error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
102 119
103While not mandatory, it is I<highly> recommended to set this callback, as 120While not mandatory, it is I<highly> recommended to set this callback, as
124This sets the callback that is called when the write buffer becomes empty 141This sets the callback that is called when the write buffer becomes empty
125(or when the callback is set and the buffer is empty already). 142(or when the callback is set and the buffer is empty already).
126 143
127To append to the write buffer, use the C<< ->push_write >> method. 144To append to the write buffer, use the C<< ->push_write >> method.
128 145
146This callback is useful when you don't want to put all of your write data
147into the queue at once, for example, when you want to write the contents
148of some file to the socket you might not want to read the whole file into
149memory and push it into the queue, but instead only read more data from
150the file when the write queue becomes empty.
151
129=item timeout => $fractional_seconds 152=item timeout => $fractional_seconds
130 153
131If non-zero, then this enables an "inactivity" timeout: whenever this many 154If non-zero, then this enables an "inactivity" timeout: whenever this many
132seconds pass without a successful read or write on the underlying file 155seconds pass without a successful read or write on the underlying file
133handle, the C<on_timeout> callback will be invoked (and if that one is 156handle, the C<on_timeout> callback will be invoked (and if that one is
134missing, an C<ETIMEDOUT> error will be raised). 157missing, a non-fatal C<ETIMEDOUT> error will be raised).
135 158
136Note that timeout processing is also active when you currently do not have 159Note that timeout processing is also active when you currently do not have
137any outstanding read or write requests: If you plan to keep the connection 160any outstanding read or write requests: If you plan to keep the connection
138idle then you should disable the timout temporarily or ignore the timeout 161idle then you should disable the timout temporarily or ignore the timeout
139in the C<on_timeout> callback. 162in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
163restart the timeout.
140 164
141Zero (the default) disables this timeout. 165Zero (the default) disables this timeout.
142 166
143=item on_timeout => $cb->($handle) 167=item on_timeout => $cb->($handle)
144 168
148 172
149=item rbuf_max => <bytes> 173=item rbuf_max => <bytes>
150 174
151If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 175If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
152when the read buffer ever (strictly) exceeds this size. This is useful to 176when the read buffer ever (strictly) exceeds this size. This is useful to
153avoid denial-of-service attacks. 177avoid some forms of denial-of-service attacks.
154 178
155For example, a server accepting connections from untrusted sources should 179For example, a server accepting connections from untrusted sources should
156be configured to accept only so-and-so much data that it cannot act on 180be configured to accept only so-and-so much data that it cannot act on
157(for example, when expecting a line, an attacker could send an unlimited 181(for example, when expecting a line, an attacker could send an unlimited
158amount of data without a callback ever being called as long as the line 182amount of data without a callback ever being called as long as the line
159isn't finished). 183isn't finished).
160 184
185=item autocork => <boolean>
186
187When disabled (the default), then C<push_write> will try to immediately
188write the data to the handle, if possible. This avoids having to register
189a write watcher and wait for the next event loop iteration, but can
190be inefficient if you write multiple small chunks (on the wire, this
191disadvantage is usually avoided by your kernel's nagle algorithm, see
192C<no_delay>, but this option can save costly syscalls).
193
194When enabled, then writes will always be queued till the next event loop
195iteration. This is efficient when you do many small writes per iteration,
196but less efficient when you do a single write only per iteration (or when
197the write buffer often is full). It also increases write latency.
198
199=item no_delay => <boolean>
200
201When doing small writes on sockets, your operating system kernel might
202wait a bit for more data before actually sending it out. This is called
203the Nagle algorithm, and usually it is beneficial.
204
205In some situations you want as low a delay as possible, which can be
206accomplishd by setting this option to a true value.
207
208The default is your opertaing system's default behaviour (most likely
209enabled), this option explicitly enables or disables it, if possible.
210
161=item read_size => <bytes> 211=item read_size => <bytes>
162 212
163The default read block size (the amount of bytes this module will try to read 213The default read block size (the amount of bytes this module will
164during each (loop iteration). Default: C<8192>. 214try to read during each loop iteration, which affects memory
215requirements). Default: C<8192>.
165 216
166=item low_water_mark => <bytes> 217=item low_water_mark => <bytes>
167 218
168Sets the amount of bytes (default: C<0>) that make up an "empty" write 219Sets the amount of bytes (default: C<0>) that make up an "empty" write
169buffer: If the write reaches this size or gets even samller it is 220buffer: If the write reaches this size or gets even samller it is
170considered empty. 221considered empty.
171 222
223Sometimes it can be beneficial (for performance reasons) to add data to
224the write buffer before it is fully drained, but this is a rare case, as
225the operating system kernel usually buffers data as well, so the default
226is good in almost all cases.
227
172=item linger => <seconds> 228=item linger => <seconds>
173 229
174If non-zero (default: C<3600>), then the destructor of the 230If non-zero (default: C<3600>), then the destructor of the
175AnyEvent::Handle object will check wether there is still outstanding write 231AnyEvent::Handle object will check whether there is still outstanding
176data and will install a watcher that will write out this data. No errors 232write data and will install a watcher that will write this data to the
177will be reported (this mostly matches how the operating system treats 233socket. No errors will be reported (this mostly matches how the operating
178outstanding data at socket close time). 234system treats outstanding data at socket close time).
179 235
180This will not work for partial TLS data that could not yet been 236This will not work for partial TLS data that could not be encoded
181encoded. This data will be lost. 237yet. This data will be lost. Calling the C<stoptls> method in time might
238help.
182 239
183=item tls => "accept" | "connect" | Net::SSLeay::SSL object 240=item tls => "accept" | "connect" | Net::SSLeay::SSL object
184 241
185When this parameter is given, it enables TLS (SSL) mode, that means it 242When this parameter is given, it enables TLS (SSL) mode, that means
186will start making tls handshake and will transparently encrypt/decrypt 243AnyEvent will start a TLS handshake as soon as the conenction has been
187data. 244established and will transparently encrypt/decrypt data afterwards.
188 245
189TLS mode requires Net::SSLeay to be installed (it will be loaded 246TLS mode requires Net::SSLeay to be installed (it will be loaded
190automatically when you try to create a TLS handle). 247automatically when you try to create a TLS handle): this module doesn't
248have a dependency on that module, so if your module requires it, you have
249to add the dependency yourself.
191 250
192For the TLS server side, use C<accept>, and for the TLS client side of a 251Unlike TCP, TLS has a server and client side: for the TLS server side, use
193connection, use C<connect> mode. 252C<accept>, and for the TLS client side of a connection, use C<connect>
253mode.
194 254
195You can also provide your own TLS connection object, but you have 255You can also provide your own TLS connection object, but you have
196to make sure that you call either C<Net::SSLeay::set_connect_state> 256to make sure that you call either C<Net::SSLeay::set_connect_state>
197or C<Net::SSLeay::set_accept_state> on it before you pass it to 257or C<Net::SSLeay::set_accept_state> on it before you pass it to
198AnyEvent::Handle. 258AnyEvent::Handle.
199 259
260B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
261passing in the wrong integer will lead to certain crash. This most often
262happens when one uses a stylish C<< tls => 1 >> and is surprised about the
263segmentation fault.
264
200See the C<starttls> method if you need to start TLs negotiation later. 265See the C<< ->starttls >> method for when need to start TLS negotiation later.
201 266
202=item tls_ctx => $ssl_ctx 267=item tls_ctx => $ssl_ctx
203 268
204Use the given Net::SSLeay::CTX object to create the new TLS connection 269Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
205(unless a connection object was specified directly). If this parameter is 270(unless a connection object was specified directly). If this parameter is
206missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 271missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
207 272
208=item json => JSON or JSON::XS object 273=item json => JSON or JSON::XS object
209 274
210This is the json coder object used by the C<json> read and write types. 275This is the json coder object used by the C<json> read and write types.
211 276
212If you don't supply it, then AnyEvent::Handle will create and use a 277If you don't supply it, then AnyEvent::Handle will create and use a
213suitable one, which will write and expect UTF-8 encoded JSON texts. 278suitable one (on demand), which will write and expect UTF-8 encoded JSON
279texts.
214 280
215Note that you are responsible to depend on the JSON module if you want to 281Note that you are responsible to depend on the JSON module if you want to
216use this functionality, as AnyEvent does not have a dependency itself. 282use this functionality, as AnyEvent does not have a dependency itself.
217 283
218=item filter_r => $cb
219
220=item filter_w => $cb
221
222These exist, but are undocumented at this time.
223
224=back 284=back
225 285
226=cut 286=cut
227 287
228sub new { 288sub new {
232 292
233 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 293 $self->{fh} or Carp::croak "mandatory argument fh is missing";
234 294
235 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 295 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
236 296
237 if ($self->{tls}) {
238 require Net::SSLeay;
239 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 297 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
240 } 298 if $self->{tls};
241 299
242 $self->{_activity} = AnyEvent->now; 300 $self->{_activity} = AnyEvent->now;
243 $self->_timeout; 301 $self->_timeout;
244 302
245 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 303 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
304 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
305
306 $self->start_read
307 if $self->{on_read};
246 308
247 $self 309 $self
248} 310}
249 311
250sub _shutdown { 312sub _shutdown {
253 delete $self->{_tw}; 315 delete $self->{_tw};
254 delete $self->{_rw}; 316 delete $self->{_rw};
255 delete $self->{_ww}; 317 delete $self->{_ww};
256 delete $self->{fh}; 318 delete $self->{fh};
257 319
258 $self->stoptls; 320 &_freetls;
321
322 delete $self->{on_read};
323 delete $self->{_queue};
259} 324}
260 325
261sub _error { 326sub _error {
262 my ($self, $errno, $fatal) = @_; 327 my ($self, $errno, $fatal) = @_;
263 328
266 331
267 $! = $errno; 332 $! = $errno;
268 333
269 if ($self->{on_error}) { 334 if ($self->{on_error}) {
270 $self->{on_error}($self, $fatal); 335 $self->{on_error}($self, $fatal);
271 } else { 336 } elsif ($self->{fh}) {
272 Carp::croak "AnyEvent::Handle uncaught error: $!"; 337 Carp::croak "AnyEvent::Handle uncaught error: $!";
273 } 338 }
274} 339}
275 340
276=item $fh = $handle->fh 341=item $fh = $handle->fh
277 342
278This method returns the file handle of the L<AnyEvent::Handle> object. 343This method returns the file handle used to create the L<AnyEvent::Handle> object.
279 344
280=cut 345=cut
281 346
282sub fh { $_[0]{fh} } 347sub fh { $_[0]{fh} }
283 348
301 $_[0]{on_eof} = $_[1]; 366 $_[0]{on_eof} = $_[1];
302} 367}
303 368
304=item $handle->on_timeout ($cb) 369=item $handle->on_timeout ($cb)
305 370
306Replace the current C<on_timeout> callback, or disables the callback 371Replace the current C<on_timeout> callback, or disables the callback (but
307(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 372not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
308argument. 373argument and method.
309 374
310=cut 375=cut
311 376
312sub on_timeout { 377sub on_timeout {
313 $_[0]{on_timeout} = $_[1]; 378 $_[0]{on_timeout} = $_[1];
379}
380
381=item $handle->autocork ($boolean)
382
383Enables or disables the current autocork behaviour (see C<autocork>
384constructor argument). Changes will only take effect on the next write.
385
386=cut
387
388sub autocork {
389 $_[0]{autocork} = $_[1];
390}
391
392=item $handle->no_delay ($boolean)
393
394Enables or disables the C<no_delay> setting (see constructor argument of
395the same name for details).
396
397=cut
398
399sub no_delay {
400 $_[0]{no_delay} = $_[1];
401
402 eval {
403 local $SIG{__DIE__};
404 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
405 };
314} 406}
315 407
316############################################################################# 408#############################################################################
317 409
318=item $handle->timeout ($seconds) 410=item $handle->timeout ($seconds)
396 my ($self, $cb) = @_; 488 my ($self, $cb) = @_;
397 489
398 $self->{on_drain} = $cb; 490 $self->{on_drain} = $cb;
399 491
400 $cb->($self) 492 $cb->($self)
401 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 493 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
402} 494}
403 495
404=item $handle->push_write ($data) 496=item $handle->push_write ($data)
405 497
406Queues the given scalar to be written. You can push as much data as you 498Queues the given scalar to be written. You can push as much data as you
423 substr $self->{wbuf}, 0, $len, ""; 515 substr $self->{wbuf}, 0, $len, "";
424 516
425 $self->{_activity} = AnyEvent->now; 517 $self->{_activity} = AnyEvent->now;
426 518
427 $self->{on_drain}($self) 519 $self->{on_drain}($self)
428 if $self->{low_water_mark} >= length $self->{wbuf} 520 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
429 && $self->{on_drain}; 521 && $self->{on_drain};
430 522
431 delete $self->{_ww} unless length $self->{wbuf}; 523 delete $self->{_ww} unless length $self->{wbuf};
432 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 524 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
433 $self->_error ($!, 1); 525 $self->_error ($!, 1);
434 } 526 }
435 }; 527 };
436 528
437 # try to write data immediately 529 # try to write data immediately
438 $cb->(); 530 $cb->() unless $self->{autocork};
439 531
440 # if still data left in wbuf, we need to poll 532 # if still data left in wbuf, we need to poll
441 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 533 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
442 if length $self->{wbuf}; 534 if length $self->{wbuf};
443 }; 535 };
457 549
458 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 550 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
459 ->($self, @_); 551 ->($self, @_);
460 } 552 }
461 553
462 if ($self->{filter_w}) { 554 if ($self->{tls}) {
463 $self->{filter_w}($self, \$_[0]); 555 $self->{_tls_wbuf} .= $_[0];
556
557 &_dotls ($self);
464 } else { 558 } else {
465 $self->{wbuf} .= $_[0]; 559 $self->{wbuf} .= $_[0];
466 $self->_drain_wbuf; 560 $self->_drain_wbuf;
467 } 561 }
468} 562}
485=cut 579=cut
486 580
487register_write_type netstring => sub { 581register_write_type netstring => sub {
488 my ($self, $string) = @_; 582 my ($self, $string) = @_;
489 583
490 sprintf "%d:%s,", (length $string), $string 584 (length $string) . ":$string,"
491}; 585};
492 586
493=item packstring => $format, $data 587=item packstring => $format, $data
494 588
495An octet string prefixed with an encoded length. The encoding C<$format> 589An octet string prefixed with an encoded length. The encoding C<$format>
500=cut 594=cut
501 595
502register_write_type packstring => sub { 596register_write_type packstring => sub {
503 my ($self, $format, $string) = @_; 597 my ($self, $format, $string) = @_;
504 598
505 pack "$format/a", $string 599 pack "$format/a*", $string
506}; 600};
507 601
508=item json => $array_or_hashref 602=item json => $array_or_hashref
509 603
510Encodes the given hash or array reference into a JSON object. Unless you 604Encodes the given hash or array reference into a JSON object. Unless you
556register_write_type storable => sub { 650register_write_type storable => sub {
557 my ($self, $ref) = @_; 651 my ($self, $ref) = @_;
558 652
559 require Storable; 653 require Storable;
560 654
561 pack "w/a", Storable::nfreeze ($ref) 655 pack "w/a*", Storable::nfreeze ($ref)
562}; 656};
563 657
564=back 658=back
565 659
566=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 660=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
590ways, the "simple" way, using only C<on_read> and the "complex" way, using 684ways, the "simple" way, using only C<on_read> and the "complex" way, using
591a queue. 685a queue.
592 686
593In the simple case, you just install an C<on_read> callback and whenever 687In the simple case, you just install an C<on_read> callback and whenever
594new data arrives, it will be called. You can then remove some data (if 688new data arrives, it will be called. You can then remove some data (if
595enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 689enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
596or not. 690leave the data there if you want to accumulate more (e.g. when only a
691partial message has been received so far).
597 692
598In the more complex case, you want to queue multiple callbacks. In this 693In the more complex case, you want to queue multiple callbacks. In this
599case, AnyEvent::Handle will call the first queued callback each time new 694case, AnyEvent::Handle will call the first queued callback each time new
600data arrives (also the first time it is queued) and removes it when it has 695data arrives (also the first time it is queued) and removes it when it has
601done its job (see C<push_read>, below). 696done its job (see C<push_read>, below).
619 # handle xml 714 # handle xml
620 }); 715 });
621 }); 716 });
622 }); 717 });
623 718
624Example 2: Implement a client for a protocol that replies either with 719Example 2: Implement a client for a protocol that replies either with "OK"
625"OK" and another line or "ERROR" for one request, and 64 bytes for the 720and another line or "ERROR" for the first request that is sent, and 64
626second request. Due tot he availability of a full queue, we can just 721bytes for the second request. Due to the availability of a queue, we can
627pipeline sending both requests and manipulate the queue as necessary in 722just pipeline sending both requests and manipulate the queue as necessary
628the callbacks: 723in the callbacks.
629 724
630 # request one 725When the first callback is called and sees an "OK" response, it will
726C<unshift> another line-read. This line-read will be queued I<before> the
72764-byte chunk callback.
728
729 # request one, returns either "OK + extra line" or "ERROR"
631 $handle->push_write ("request 1\015\012"); 730 $handle->push_write ("request 1\015\012");
632 731
633 # we expect "ERROR" or "OK" as response, so push a line read 732 # we expect "ERROR" or "OK" as response, so push a line read
634 $handle->push_read (line => sub { 733 $handle->push_read (line => sub {
635 # if we got an "OK", we have to _prepend_ another line, 734 # if we got an "OK", we have to _prepend_ another line,
642 ... 741 ...
643 }); 742 });
644 } 743 }
645 }); 744 });
646 745
647 # request two 746 # request two, simply returns 64 octets
648 $handle->push_write ("request 2\015\012"); 747 $handle->push_write ("request 2\015\012");
649 748
650 # simply read 64 bytes, always 749 # simply read 64 bytes, always
651 $handle->push_read (chunk => 64, sub { 750 $handle->push_read (chunk => 64, sub {
652 my $response = $_[1]; 751 my $response = $_[1];
664 763
665 if ( 764 if (
666 defined $self->{rbuf_max} 765 defined $self->{rbuf_max}
667 && $self->{rbuf_max} < length $self->{rbuf} 766 && $self->{rbuf_max} < length $self->{rbuf}
668 ) { 767 ) {
669 return $self->_error (&Errno::ENOSPC, 1); 768 $self->_error (&Errno::ENOSPC, 1), return;
670 } 769 }
671 770
672 while () { 771 while () {
673 no strict 'refs';
674
675 my $len = length $self->{rbuf}; 772 my $len = length $self->{rbuf};
676 773
677 if (my $cb = shift @{ $self->{_queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
678 unless ($cb->($self)) { 775 unless ($cb->($self)) {
679 if ($self->{_eof}) { 776 if ($self->{_eof}) {
680 # no progress can be made (not enough data and no data forthcoming) 777 # no progress can be made (not enough data and no data forthcoming)
681 $self->_error (&Errno::EPIPE, 1), last; 778 $self->_error (&Errno::EPIPE, 1), return;
682 } 779 }
683 780
684 unshift @{ $self->{_queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
685 last; 782 last;
686 } 783 }
694 && !@{ $self->{_queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
695 && $self->{on_read} # but we still have on_read 792 && $self->{on_read} # but we still have on_read
696 ) { 793 ) {
697 # no further data will arrive 794 # no further data will arrive
698 # so no progress can be made 795 # so no progress can be made
699 $self->_error (&Errno::EPIPE, 1), last 796 $self->_error (&Errno::EPIPE, 1), return
700 if $self->{_eof}; 797 if $self->{_eof};
701 798
702 last; # more data might arrive 799 last; # more data might arrive
703 } 800 }
704 } else { 801 } else {
705 # read side becomes idle 802 # read side becomes idle
706 delete $self->{_rw}; 803 delete $self->{_rw} unless $self->{tls};
707 last; 804 last;
708 } 805 }
709 } 806 }
710 807
808 if ($self->{_eof}) {
809 if ($self->{on_eof}) {
711 $self->{on_eof}($self) 810 $self->{on_eof}($self)
712 if $self->{_eof} && $self->{on_eof}; 811 } else {
812 $self->_error (0, 1);
813 }
814 }
713 815
714 # may need to restart read watcher 816 # may need to restart read watcher
715 unless ($self->{_rw}) { 817 unless ($self->{_rw}) {
716 $self->start_read 818 $self->start_read
717 if $self->{on_read} || @{ $self->{_queue} }; 819 if $self->{on_read} || @{ $self->{_queue} };
843 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 945 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
844 1 946 1
845 } 947 }
846}; 948};
847 949
848# compatibility with older API
849sub push_read_chunk {
850 $_[0]->push_read (chunk => $_[1], $_[2]);
851}
852
853sub unshift_read_chunk {
854 $_[0]->unshift_read (chunk => $_[1], $_[2]);
855}
856
857=item line => [$eol, ]$cb->($handle, $line, $eol) 950=item line => [$eol, ]$cb->($handle, $line, $eol)
858 951
859The callback will be called only once a full line (including the end of 952The callback will be called only once a full line (including the end of
860line marker, C<$eol>) has been read. This line (excluding the end of line 953line marker, C<$eol>) has been read. This line (excluding the end of line
861marker) will be passed to the callback as second argument (C<$line>), and 954marker) will be passed to the callback as second argument (C<$line>), and
876=cut 969=cut
877 970
878register_read_type line => sub { 971register_read_type line => sub {
879 my ($self, $cb, $eol) = @_; 972 my ($self, $cb, $eol) = @_;
880 973
881 $eol = qr|(\015?\012)| if @_ < 3; 974 if (@_ < 3) {
975 # this is more than twice as fast as the generic code below
976 sub {
977 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
978
979 $cb->($_[0], $1, $2);
980 1
981 }
982 } else {
882 $eol = quotemeta $eol unless ref $eol; 983 $eol = quotemeta $eol unless ref $eol;
883 $eol = qr|^(.*?)($eol)|s; 984 $eol = qr|^(.*?)($eol)|s;
884 985
885 sub { 986 sub {
886 $_[0]{rbuf} =~ s/$eol// or return; 987 $_[0]{rbuf} =~ s/$eol// or return;
887 988
888 $cb->($_[0], $1, $2); 989 $cb->($_[0], $1, $2);
990 1
889 1 991 }
890 } 992 }
891}; 993};
892
893# compatibility with older API
894sub push_read_line {
895 my $self = shift;
896 $self->push_read (line => @_);
897}
898
899sub unshift_read_line {
900 my $self = shift;
901 $self->unshift_read (line => @_);
902}
903 994
904=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 995=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
905 996
906Makes a regex match against the regex object C<$accept> and returns 997Makes a regex match against the regex object C<$accept> and returns
907everything up to and including the match. 998everything up to and including the match.
1012An octet string prefixed with an encoded length. The encoding C<$format> 1103An octet string prefixed with an encoded length. The encoding C<$format>
1013uses the same format as a Perl C<pack> format, but must specify a single 1104uses the same format as a Perl C<pack> format, but must specify a single
1014integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1105integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1015optional C<!>, C<< < >> or C<< > >> modifier). 1106optional C<!>, C<< < >> or C<< > >> modifier).
1016 1107
1017DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1108For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1109EPP uses a prefix of C<N> (4 octtes).
1018 1110
1019Example: read a block of data prefixed by its length in BER-encoded 1111Example: read a block of data prefixed by its length in BER-encoded
1020format (very efficient). 1112format (very efficient).
1021 1113
1022 $handle->push_read (packstring => "w", sub { 1114 $handle->push_read (packstring => "w", sub {
1028register_read_type packstring => sub { 1120register_read_type packstring => sub {
1029 my ($self, $cb, $format) = @_; 1121 my ($self, $cb, $format) = @_;
1030 1122
1031 sub { 1123 sub {
1032 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method 1124 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1033 defined (my $len = eval { unpack $format, $_[0]->{rbuf} }) 1125 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1034 or return; 1126 or return;
1035 1127
1128 $format = length pack $format, $len;
1129
1130 # bypass unshift if we already have the remaining chunk
1131 if ($format + $len <= length $_[0]{rbuf}) {
1132 my $data = substr $_[0]{rbuf}, $format, $len;
1133 substr $_[0]{rbuf}, 0, $format + $len, "";
1134 $cb->($_[0], $data);
1135 } else {
1036 # remove prefix 1136 # remove prefix
1037 substr $_[0]->{rbuf}, 0, (length pack $format, $len), ""; 1137 substr $_[0]{rbuf}, 0, $format, "";
1038 1138
1039 # read rest 1139 # read remaining chunk
1040 $_[0]->unshift_read (chunk => $len, $cb); 1140 $_[0]->unshift_read (chunk => $len, $cb);
1141 }
1041 1142
1042 1 1143 1
1043 } 1144 }
1044}; 1145};
1045 1146
1102 1203
1103 require Storable; 1204 require Storable;
1104 1205
1105 sub { 1206 sub {
1106 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method 1207 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1107 defined (my $len = eval { unpack "w", $_[0]->{rbuf} }) 1208 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1108 or return; 1209 or return;
1109 1210
1211 my $format = length pack "w", $len;
1212
1213 # bypass unshift if we already have the remaining chunk
1214 if ($format + $len <= length $_[0]{rbuf}) {
1215 my $data = substr $_[0]{rbuf}, $format, $len;
1216 substr $_[0]{rbuf}, 0, $format + $len, "";
1217 $cb->($_[0], Storable::thaw ($data));
1218 } else {
1110 # remove prefix 1219 # remove prefix
1111 substr $_[0]->{rbuf}, 0, (length pack "w", $len), ""; 1220 substr $_[0]{rbuf}, 0, $format, "";
1112 1221
1113 # read rest 1222 # read remaining chunk
1114 $_[0]->unshift_read (chunk => $len, sub { 1223 $_[0]->unshift_read (chunk => $len, sub {
1115 if (my $ref = eval { Storable::thaw ($_[1]) }) { 1224 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1116 $cb->($_[0], $ref); 1225 $cb->($_[0], $ref);
1117 } else { 1226 } else {
1118 $self->_error (&Errno::EBADMSG); 1227 $self->_error (&Errno::EBADMSG);
1228 }
1119 } 1229 });
1120 }); 1230 }
1231
1232 1
1121 } 1233 }
1122}; 1234};
1123 1235
1124=back 1236=back
1125 1237
1155Note that AnyEvent::Handle will automatically C<start_read> for you when 1267Note that AnyEvent::Handle will automatically C<start_read> for you when
1156you change the C<on_read> callback or push/unshift a read callback, and it 1268you change the C<on_read> callback or push/unshift a read callback, and it
1157will automatically C<stop_read> for you when neither C<on_read> is set nor 1269will automatically C<stop_read> for you when neither C<on_read> is set nor
1158there are any read requests in the queue. 1270there are any read requests in the queue.
1159 1271
1272These methods will have no effect when in TLS mode (as TLS doesn't support
1273half-duplex connections).
1274
1160=cut 1275=cut
1161 1276
1162sub stop_read { 1277sub stop_read {
1163 my ($self) = @_; 1278 my ($self) = @_;
1164 1279
1165 delete $self->{_rw}; 1280 delete $self->{_rw} unless $self->{tls};
1166} 1281}
1167 1282
1168sub start_read { 1283sub start_read {
1169 my ($self) = @_; 1284 my ($self) = @_;
1170 1285
1171 unless ($self->{_rw} || $self->{_eof}) { 1286 unless ($self->{_rw} || $self->{_eof}) {
1172 Scalar::Util::weaken $self; 1287 Scalar::Util::weaken $self;
1173 1288
1174 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1289 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1175 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1290 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1176 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1291 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1177 1292
1178 if ($len > 0) { 1293 if ($len > 0) {
1179 $self->{_activity} = AnyEvent->now; 1294 $self->{_activity} = AnyEvent->now;
1180 1295
1181 $self->{filter_r} 1296 if ($self->{tls}) {
1182 ? $self->{filter_r}($self, $rbuf) 1297 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1183 : $self->{_in_drain} || $self->_drain_rbuf; 1298
1299 &_dotls ($self);
1300 } else {
1301 $self->_drain_rbuf unless $self->{_in_drain};
1302 }
1184 1303
1185 } elsif (defined $len) { 1304 } elsif (defined $len) {
1186 delete $self->{_rw}; 1305 delete $self->{_rw};
1187 $self->{_eof} = 1; 1306 $self->{_eof} = 1;
1188 $self->_drain_rbuf unless $self->{_in_drain}; 1307 $self->_drain_rbuf unless $self->{_in_drain};
1192 } 1311 }
1193 }); 1312 });
1194 } 1313 }
1195} 1314}
1196 1315
1316# poll the write BIO and send the data if applicable
1197sub _dotls { 1317sub _dotls {
1198 my ($self) = @_; 1318 my ($self) = @_;
1199 1319
1200 my $buf; 1320 my $tmp;
1201 1321
1202 if (length $self->{_tls_wbuf}) { 1322 if (length $self->{_tls_wbuf}) {
1203 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1323 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1204 substr $self->{_tls_wbuf}, 0, $len, ""; 1324 substr $self->{_tls_wbuf}, 0, $tmp, "";
1205 } 1325 }
1206 } 1326 }
1207 1327
1208 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1209 $self->{wbuf} .= $buf;
1210 $self->_drain_wbuf;
1211 }
1212
1213 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1328 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1214 if (length $buf) { 1329 unless (length $tmp) {
1215 $self->{rbuf} .= $buf;
1216 $self->_drain_rbuf unless $self->{_in_drain};
1217 } else {
1218 # let's treat SSL-eof as we treat normal EOF 1330 # let's treat SSL-eof as we treat normal EOF
1331 delete $self->{_rw};
1219 $self->{_eof} = 1; 1332 $self->{_eof} = 1;
1220 $self->_shutdown; 1333 &_freetls;
1221 return;
1222 } 1334 }
1223 }
1224 1335
1336 $self->{rbuf} .= $tmp;
1337 $self->_drain_rbuf unless $self->{_in_drain};
1338 $self->{tls} or return; # tls session might have gone away in callback
1339 }
1340
1225 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1341 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1226 1342
1227 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1343 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1228 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1344 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1229 return $self->_error ($!, 1); 1345 return $self->_error ($!, 1);
1230 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1346 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1231 return $self->_error (&Errno::EIO, 1); 1347 return $self->_error (&Errno::EIO, 1);
1232 } 1348 }
1233 1349
1234 # all others are fine for our purposes 1350 # all other errors are fine for our purposes
1351 }
1352
1353 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1354 $self->{wbuf} .= $tmp;
1355 $self->_drain_wbuf;
1235 } 1356 }
1236} 1357}
1237 1358
1238=item $handle->starttls ($tls[, $tls_ctx]) 1359=item $handle->starttls ($tls[, $tls_ctx])
1239 1360
1249 1370
1250The TLS connection object will end up in C<< $handle->{tls} >> after this 1371The TLS connection object will end up in C<< $handle->{tls} >> after this
1251call and can be used or changed to your liking. Note that the handshake 1372call and can be used or changed to your liking. Note that the handshake
1252might have already started when this function returns. 1373might have already started when this function returns.
1253 1374
1375If it an error to start a TLS handshake more than once per
1376AnyEvent::Handle object (this is due to bugs in OpenSSL).
1377
1254=cut 1378=cut
1255 1379
1256sub starttls { 1380sub starttls {
1257 my ($self, $ssl, $ctx) = @_; 1381 my ($self, $ssl, $ctx) = @_;
1258 1382
1259 $self->stoptls; 1383 require Net::SSLeay;
1260 1384
1385 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1386 if $self->{tls};
1387
1261 if ($ssl eq "accept") { 1388 if ($ssl eq "accept") {
1262 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1389 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1263 Net::SSLeay::set_accept_state ($ssl); 1390 Net::SSLeay::set_accept_state ($ssl);
1264 } elsif ($ssl eq "connect") { 1391 } elsif ($ssl eq "connect") {
1265 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1392 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1271 # basically, this is deep magic (because SSL_read should have the same issues) 1398 # basically, this is deep magic (because SSL_read should have the same issues)
1272 # but the openssl maintainers basically said: "trust us, it just works". 1399 # but the openssl maintainers basically said: "trust us, it just works".
1273 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1400 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1274 # and mismaintained ssleay-module doesn't even offer them). 1401 # and mismaintained ssleay-module doesn't even offer them).
1275 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1402 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1403 #
1404 # in short: this is a mess.
1405 #
1406 # note that we do not try to keep the length constant between writes as we are required to do.
1407 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1408 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1409 # have identity issues in that area.
1276 Net::SSLeay::CTX_set_mode ($self->{tls}, 1410 Net::SSLeay::CTX_set_mode ($self->{tls},
1277 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1411 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1278 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1412 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1279 1413
1280 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1414 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1281 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1415 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1282 1416
1283 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1417 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1284 1418
1285 $self->{filter_w} = sub { 1419 &_dotls; # need to trigger the initial handshake
1286 $_[0]{_tls_wbuf} .= ${$_[1]}; 1420 $self->start_read; # make sure we actually do read
1287 &_dotls;
1288 };
1289 $self->{filter_r} = sub {
1290 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1291 &_dotls;
1292 };
1293} 1421}
1294 1422
1295=item $handle->stoptls 1423=item $handle->stoptls
1296 1424
1297Destroys the SSL connection, if any. Partial read or write data will be 1425Shuts down the SSL connection - this makes a proper EOF handshake by
1298lost. 1426sending a close notify to the other side, but since OpenSSL doesn't
1427support non-blocking shut downs, it is not possible to re-use the stream
1428afterwards.
1299 1429
1300=cut 1430=cut
1301 1431
1302sub stoptls { 1432sub stoptls {
1303 my ($self) = @_; 1433 my ($self) = @_;
1304 1434
1435 if ($self->{tls}) {
1436 Net::SSLeay::shutdown ($self->{tls});
1437
1438 &_dotls;
1439
1440 # we don't give a shit. no, we do, but we can't. no...
1441 # we, we... have to use openssl :/
1442 &_freetls;
1443 }
1444}
1445
1446sub _freetls {
1447 my ($self) = @_;
1448
1449 return unless $self->{tls};
1450
1305 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1451 Net::SSLeay::free (delete $self->{tls});
1306 1452
1307 delete $self->{_rbio}; 1453 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1308 delete $self->{_wbio};
1309 delete $self->{_tls_wbuf};
1310 delete $self->{filter_r};
1311 delete $self->{filter_w};
1312} 1454}
1313 1455
1314sub DESTROY { 1456sub DESTROY {
1315 my $self = shift; 1457 my $self = shift;
1316 1458
1317 $self->stoptls; 1459 &_freetls;
1318 1460
1319 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1461 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1320 1462
1321 if ($linger && length $self->{wbuf}) { 1463 if ($linger && length $self->{wbuf}) {
1322 my $fh = delete $self->{fh}; 1464 my $fh = delete $self->{fh};
1337 @linger = (); 1479 @linger = ();
1338 }); 1480 });
1339 } 1481 }
1340} 1482}
1341 1483
1484=item $handle->destroy
1485
1486Shuts down the handle object as much as possible - this call ensures that
1487no further callbacks will be invoked and resources will be freed as much
1488as possible. You must not call any methods on the object afterwards.
1489
1490Normally, you can just "forget" any references to an AnyEvent::Handle
1491object and it will simply shut down. This works in fatal error and EOF
1492callbacks, as well as code outside. It does I<NOT> work in a read or write
1493callback, so when you want to destroy the AnyEvent::Handle object from
1494within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1495that case.
1496
1497The handle might still linger in the background and write out remaining
1498data, as specified by the C<linger> option, however.
1499
1500=cut
1501
1502sub destroy {
1503 my ($self) = @_;
1504
1505 $self->DESTROY;
1506 %$self = ();
1507}
1508
1342=item AnyEvent::Handle::TLS_CTX 1509=item AnyEvent::Handle::TLS_CTX
1343 1510
1344This function creates and returns the Net::SSLeay::CTX object used by 1511This function creates and returns the Net::SSLeay::CTX object used by
1345default for TLS mode. 1512default for TLS mode.
1346 1513
1374 } 1541 }
1375} 1542}
1376 1543
1377=back 1544=back
1378 1545
1546
1547=head1 NONFREQUENTLY ASKED QUESTIONS
1548
1549=over 4
1550
1551=item I C<undef> the AnyEvent::Handle reference inside my callback and
1552still get further invocations!
1553
1554That's because AnyEvent::Handle keeps a reference to itself when handling
1555read or write callbacks.
1556
1557It is only safe to "forget" the reference inside EOF or error callbacks,
1558from within all other callbacks, you need to explicitly call the C<<
1559->destroy >> method.
1560
1561=item I get different callback invocations in TLS mode/Why can't I pause
1562reading?
1563
1564Unlike, say, TCP, TLS connections do not consist of two independent
1565communication channels, one for each direction. Or put differently. The
1566read and write directions are not independent of each other: you cannot
1567write data unless you are also prepared to read, and vice versa.
1568
1569This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1570callback invocations when you are not expecting any read data - the reason
1571is that AnyEvent::Handle always reads in TLS mode.
1572
1573During the connection, you have to make sure that you always have a
1574non-empty read-queue, or an C<on_read> watcher. At the end of the
1575connection (or when you no longer want to use it) you can call the
1576C<destroy> method.
1577
1578=item How do I read data until the other side closes the connection?
1579
1580If you just want to read your data into a perl scalar, the easiest way
1581to achieve this is by setting an C<on_read> callback that does nothing,
1582clearing the C<on_eof> callback and in the C<on_error> callback, the data
1583will be in C<$_[0]{rbuf}>:
1584
1585 $handle->on_read (sub { });
1586 $handle->on_eof (undef);
1587 $handle->on_error (sub {
1588 my $data = delete $_[0]{rbuf};
1589 undef $handle;
1590 });
1591
1592The reason to use C<on_error> is that TCP connections, due to latencies
1593and packets loss, might get closed quite violently with an error, when in
1594fact, all data has been received.
1595
1596It is usually better to use acknowledgements when transferring data,
1597to make sure the other side hasn't just died and you got the data
1598intact. This is also one reason why so many internet protocols have an
1599explicit QUIT command.
1600
1601=item I don't want to destroy the handle too early - how do I wait until
1602all data has been written?
1603
1604After writing your last bits of data, set the C<on_drain> callback
1605and destroy the handle in there - with the default setting of
1606C<low_water_mark> this will be called precisely when all data has been
1607written to the socket:
1608
1609 $handle->push_write (...);
1610 $handle->on_drain (sub {
1611 warn "all data submitted to the kernel\n";
1612 undef $handle;
1613 });
1614
1615=back
1616
1617
1379=head1 SUBCLASSING AnyEvent::Handle 1618=head1 SUBCLASSING AnyEvent::Handle
1380 1619
1381In many cases, you might want to subclass AnyEvent::Handle. 1620In many cases, you might want to subclass AnyEvent::Handle.
1382 1621
1383To make this easier, a given version of AnyEvent::Handle uses these 1622To make this easier, a given version of AnyEvent::Handle uses these
1386=over 4 1625=over 4
1387 1626
1388=item * all constructor arguments become object members. 1627=item * all constructor arguments become object members.
1389 1628
1390At least initially, when you pass a C<tls>-argument to the constructor it 1629At least initially, when you pass a C<tls>-argument to the constructor it
1391will end up in C<< $handle->{tls} >>. Those members might be changes or 1630will end up in C<< $handle->{tls} >>. Those members might be changed or
1392mutated later on (for example C<tls> will hold the TLS connection object). 1631mutated later on (for example C<tls> will hold the TLS connection object).
1393 1632
1394=item * other object member names are prefixed with an C<_>. 1633=item * other object member names are prefixed with an C<_>.
1395 1634
1396All object members not explicitly documented (internal use) are prefixed 1635All object members not explicitly documented (internal use) are prefixed

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