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Revision 1.23 by root, Sat May 24 15:11:22 2008 UTC vs.
Revision 1.115 by root, Tue Feb 10 13:58:49 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 = 4.331;
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
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
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>.
99
85=item on_error => $cb->($self) 100=item on_error => $cb->($handle, $fatal)
86 101
87This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
88occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
89or a read error. 104connect or a read error.
90 105
91The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$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
112Non-fatal errors can be retried by simply returning, but it is recommended
113to simply ignore this parameter and instead abondon the handle object
114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
93 116
94On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
95error (or C<ENOSPC> or C<EPIPE>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96 119
97While 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
98you will not be notified of errors otherwise. The default simply calls 121you will not be notified of errors otherwise. The default simply calls
99die. 122C<croak>.
100 123
101=item on_read => $cb->($self) 124=item on_read => $cb->($handle)
102 125
103This sets the default read callback, which is called when data arrives 126This sets the default read callback, which is called when data arrives
104and no read request is in the queue. 127and no read request is in the queue (unlike read queue callbacks, this
128callback will only be called when at least one octet of data is in the
129read buffer).
105 130
106To access (and remove data from) the read buffer, use the C<< ->rbuf >> 131To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107method or access the C<$self->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly.
108 133
109When an EOF condition is detected then AnyEvent::Handle will first try to 134When 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 135feed 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 136calling the C<on_eof> callback. If no progress can be made, then a fatal
112error will be raised (with C<$!> set to C<EPIPE>). 137error will be raised (with C<$!> set to C<EPIPE>).
113 138
114=item on_drain => $cb->() 139=item on_drain => $cb->($handle)
115 140
116This 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
117(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).
118 143
119To append to the write buffer, use the C<< ->push_write >> method. 144To append to the write buffer, use the C<< ->push_write >> method.
120 145
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
152=item timeout => $fractional_seconds
153
154If non-zero, then this enables an "inactivity" timeout: whenever this many
155seconds pass without a successful read or write on the underlying file
156handle, the C<on_timeout> callback will be invoked (and if that one is
157missing, a non-fatal C<ETIMEDOUT> error will be raised).
158
159Note that timeout processing is also active when you currently do not have
160any outstanding read or write requests: If you plan to keep the connection
161idle then you should disable the timout temporarily or ignore the timeout
162in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
163restart the timeout.
164
165Zero (the default) disables this timeout.
166
167=item on_timeout => $cb->($handle)
168
169Called whenever the inactivity timeout passes. If you return from this
170callback, then the timeout will be reset as if some activity had happened,
171so this condition is not fatal in any way.
172
121=item rbuf_max => <bytes> 173=item rbuf_max => <bytes>
122 174
123If 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>)
124when 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
125avoid denial-of-service attacks. 177avoid some forms of denial-of-service attacks.
126 178
127For example, a server accepting connections from untrusted sources should 179For example, a server accepting connections from untrusted sources should
128be 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
129(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
130amount 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
131isn't finished). 183isn't finished).
132 184
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
133=item read_size => <bytes> 211=item read_size => <bytes>
134 212
135The 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
136on each [loop iteration). Default: C<4096>. 214try to read during each loop iteration, which affects memory
215requirements). Default: C<8192>.
137 216
138=item low_water_mark => <bytes> 217=item low_water_mark => <bytes>
139 218
140Sets 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
141buffer: 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
142considered empty. 221considered empty.
143 222
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
228=item linger => <seconds>
229
230If non-zero (default: C<3600>), then the destructor of the
231AnyEvent::Handle object will check whether there is still outstanding
232write data and will install a watcher that will write this data to the
233socket. No errors will be reported (this mostly matches how the operating
234system treats outstanding data at socket close time).
235
236This will not work for partial TLS data that could not be encoded
237yet. This data will be lost. Calling the C<stoptls> method in time might
238help.
239
144=item tls => "accept" | "connect" | Net::SSLeay::SSL object 240=item tls => "accept" | "connect" | Net::SSLeay::SSL object
145 241
146When this parameter is given, it enables TLS (SSL) mode, that means it 242When this parameter is given, it enables TLS (SSL) mode, that means
147will start making tls handshake and will transparently encrypt/decrypt 243AnyEvent will start a TLS handshake as soon as the conenction has been
148data. 244established and will transparently encrypt/decrypt data afterwards.
149 245
150For the TLS server side, use C<accept>, and for the TLS client side of a 246TLS mode requires Net::SSLeay to be installed (it will be loaded
151connection, use C<connect> mode. 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.
250
251Unlike TCP, TLS has a server and client side: for the TLS server side, use
252C<accept>, and for the TLS client side of a connection, use C<connect>
253mode.
152 254
153You can also provide your own TLS connection object, but you have 255You can also provide your own TLS connection object, but you have
154to 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>
155or 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
156AnyEvent::Handle. 258AnyEvent::Handle.
157 259
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
265See the C<< ->starttls >> method for when need to start TLS negotiation later.
266
158=item tls_ctx => $ssl_ctx 267=item tls_ctx => $ssl_ctx
159 268
160Use 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
161(unless a connection object was specified directly). If this parameter is 270(unless a connection object was specified directly). If this parameter is
162missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 271missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
163 272
273=item json => JSON or JSON::XS object
274
275This is the json coder object used by the C<json> read and write types.
276
277If you don't supply it, then AnyEvent::Handle will create and use a
278suitable one (on demand), which will write and expect UTF-8 encoded JSON
279texts.
280
281Note that you are responsible to depend on the JSON module if you want to
282use this functionality, as AnyEvent does not have a dependency itself.
283
164=back 284=back
165 285
166=cut 286=cut
167 287
168sub new { 288sub new {
172 292
173 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 293 $self->{fh} or Carp::croak "mandatory argument fh is missing";
174 294
175 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 295 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
176 296
177 if ($self->{tls}) {
178 require Net::SSLeay;
179 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 297 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
180 } 298 if $self->{tls};
181 299
182 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 300 $self->{_activity} = AnyEvent->now;
183 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 301 $self->_timeout;
302
184 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 303 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
185 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 304 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
186 305
187 $self->start_read; 306 $self->start_read
307 if $self->{on_read};
188 308
189 $self 309 $self
190} 310}
191 311
192sub _shutdown { 312sub _shutdown {
193 my ($self) = @_; 313 my ($self) = @_;
194 314
315 delete $self->{_tw};
195 delete $self->{rw}; 316 delete $self->{_rw};
196 delete $self->{ww}; 317 delete $self->{_ww};
197 delete $self->{fh}; 318 delete $self->{fh};
198}
199 319
320 &_freetls;
321
322 delete $self->{on_read};
323 delete $self->{_queue};
324}
325
200sub error { 326sub _error {
201 my ($self) = @_; 327 my ($self, $errno, $fatal) = @_;
202 328
203 {
204 local $!;
205 $self->_shutdown; 329 $self->_shutdown
206 } 330 if $fatal;
331
332 $! = $errno;
207 333
208 if ($self->{on_error}) { 334 if ($self->{on_error}) {
209 $self->{on_error}($self); 335 $self->{on_error}($self, $fatal);
210 } else { 336 } elsif ($self->{fh}) {
211 die "AnyEvent::Handle uncaught fatal error: $!"; 337 Carp::croak "AnyEvent::Handle uncaught error: $!";
212 } 338 }
213} 339}
214 340
215=item $fh = $handle->fh 341=item $fh = $handle->fh
216 342
217This 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.
218 344
219=cut 345=cut
220 346
221sub fh { $_[0]->{fh} } 347sub fh { $_[0]{fh} }
222 348
223=item $handle->on_error ($cb) 349=item $handle->on_error ($cb)
224 350
225Replace the current C<on_error> callback (see the C<on_error> constructor argument). 351Replace the current C<on_error> callback (see the C<on_error> constructor argument).
226 352
238 364
239sub on_eof { 365sub on_eof {
240 $_[0]{on_eof} = $_[1]; 366 $_[0]{on_eof} = $_[1];
241} 367}
242 368
369=item $handle->on_timeout ($cb)
370
371Replace the current C<on_timeout> callback, or disables the callback (but
372not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
373argument and method.
374
375=cut
376
377sub on_timeout {
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 };
406}
407
408#############################################################################
409
410=item $handle->timeout ($seconds)
411
412Configures (or disables) the inactivity timeout.
413
414=cut
415
416sub timeout {
417 my ($self, $timeout) = @_;
418
419 $self->{timeout} = $timeout;
420 $self->_timeout;
421}
422
423# reset the timeout watcher, as neccessary
424# also check for time-outs
425sub _timeout {
426 my ($self) = @_;
427
428 if ($self->{timeout}) {
429 my $NOW = AnyEvent->now;
430
431 # when would the timeout trigger?
432 my $after = $self->{_activity} + $self->{timeout} - $NOW;
433
434 # now or in the past already?
435 if ($after <= 0) {
436 $self->{_activity} = $NOW;
437
438 if ($self->{on_timeout}) {
439 $self->{on_timeout}($self);
440 } else {
441 $self->_error (&Errno::ETIMEDOUT);
442 }
443
444 # callback could have changed timeout value, optimise
445 return unless $self->{timeout};
446
447 # calculate new after
448 $after = $self->{timeout};
449 }
450
451 Scalar::Util::weaken $self;
452 return unless $self; # ->error could have destroyed $self
453
454 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
455 delete $self->{_tw};
456 $self->_timeout;
457 });
458 } else {
459 delete $self->{_tw};
460 }
461}
462
243############################################################################# 463#############################################################################
244 464
245=back 465=back
246 466
247=head2 WRITE QUEUE 467=head2 WRITE QUEUE
268 my ($self, $cb) = @_; 488 my ($self, $cb) = @_;
269 489
270 $self->{on_drain} = $cb; 490 $self->{on_drain} = $cb;
271 491
272 $cb->($self) 492 $cb->($self)
273 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 493 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
274} 494}
275 495
276=item $handle->push_write ($data) 496=item $handle->push_write ($data)
277 497
278Queues 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
282=cut 502=cut
283 503
284sub _drain_wbuf { 504sub _drain_wbuf {
285 my ($self) = @_; 505 my ($self) = @_;
286 506
287 unless ($self->{ww}) { 507 if (!$self->{_ww} && length $self->{wbuf}) {
508
288 Scalar::Util::weaken $self; 509 Scalar::Util::weaken $self;
510
289 my $cb = sub { 511 my $cb = sub {
290 my $len = syswrite $self->{fh}, $self->{wbuf}; 512 my $len = syswrite $self->{fh}, $self->{wbuf};
291 513
292 if ($len > 0) { 514 if ($len >= 0) {
293 substr $self->{wbuf}, 0, $len, ""; 515 substr $self->{wbuf}, 0, $len, "";
294 516
517 $self->{_activity} = AnyEvent->now;
518
295 $self->{on_drain}($self) 519 $self->{on_drain}($self)
296 if $self->{low_water_mark} >= length $self->{wbuf} 520 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
297 && $self->{on_drain}; 521 && $self->{on_drain};
298 522
299 delete $self->{ww} unless length $self->{wbuf}; 523 delete $self->{_ww} unless length $self->{wbuf};
300 } elsif ($! != EAGAIN && $! != EINTR) { 524 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
301 $self->error; 525 $self->_error ($!, 1);
302 } 526 }
303 }; 527 };
304 528
529 # try to write data immediately
530 $cb->() unless $self->{autocork};
531
532 # if still data left in wbuf, we need to poll
305 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 533 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
306 534 if length $self->{wbuf};
307 $cb->($self);
308 }; 535 };
536}
537
538our %WH;
539
540sub register_write_type($$) {
541 $WH{$_[0]} = $_[1];
309} 542}
310 543
311sub push_write { 544sub push_write {
312 my $self = shift; 545 my $self = shift;
313 546
547 if (@_ > 1) {
548 my $type = shift;
549
550 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
551 ->($self, @_);
552 }
553
314 if ($self->{filter_w}) { 554 if ($self->{tls}) {
315 $self->{filter_w}->($self, \$_[0]); 555 $self->{_tls_wbuf} .= $_[0];
556
557 &_dotls ($self);
316 } else { 558 } else {
317 $self->{wbuf} .= $_[0]; 559 $self->{wbuf} .= $_[0];
318 $self->_drain_wbuf; 560 $self->_drain_wbuf;
319 } 561 }
320} 562}
321 563
564=item $handle->push_write (type => @args)
565
566Instead of formatting your data yourself, you can also let this module do
567the job by specifying a type and type-specific arguments.
568
569Predefined types are (if you have ideas for additional types, feel free to
570drop by and tell us):
571
572=over 4
573
574=item netstring => $string
575
576Formats the given value as netstring
577(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
578
579=cut
580
581register_write_type netstring => sub {
582 my ($self, $string) = @_;
583
584 (length $string) . ":$string,"
585};
586
587=item packstring => $format, $data
588
589An octet string prefixed with an encoded length. The encoding C<$format>
590uses the same format as a Perl C<pack> format, but must specify a single
591integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
592optional C<!>, C<< < >> or C<< > >> modifier).
593
594=cut
595
596register_write_type packstring => sub {
597 my ($self, $format, $string) = @_;
598
599 pack "$format/a*", $string
600};
601
602=item json => $array_or_hashref
603
604Encodes the given hash or array reference into a JSON object. Unless you
605provide your own JSON object, this means it will be encoded to JSON text
606in UTF-8.
607
608JSON objects (and arrays) are self-delimiting, so you can write JSON at
609one end of a handle and read them at the other end without using any
610additional framing.
611
612The generated JSON text is guaranteed not to contain any newlines: While
613this module doesn't need delimiters after or between JSON texts to be
614able to read them, many other languages depend on that.
615
616A simple RPC protocol that interoperates easily with others is to send
617JSON arrays (or objects, although arrays are usually the better choice as
618they mimic how function argument passing works) and a newline after each
619JSON text:
620
621 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
622 $handle->push_write ("\012");
623
624An AnyEvent::Handle receiver would simply use the C<json> read type and
625rely on the fact that the newline will be skipped as leading whitespace:
626
627 $handle->push_read (json => sub { my $array = $_[1]; ... });
628
629Other languages could read single lines terminated by a newline and pass
630this line into their JSON decoder of choice.
631
632=cut
633
634register_write_type json => sub {
635 my ($self, $ref) = @_;
636
637 require JSON;
638
639 $self->{json} ? $self->{json}->encode ($ref)
640 : JSON::encode_json ($ref)
641};
642
643=item storable => $reference
644
645Freezes the given reference using L<Storable> and writes it to the
646handle. Uses the C<nfreeze> format.
647
648=cut
649
650register_write_type storable => sub {
651 my ($self, $ref) = @_;
652
653 require Storable;
654
655 pack "w/a*", Storable::nfreeze ($ref)
656};
657
658=back
659
660=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
661
662This function (not method) lets you add your own types to C<push_write>.
663Whenever the given C<type> is used, C<push_write> will invoke the code
664reference with the handle object and the remaining arguments.
665
666The code reference is supposed to return a single octet string that will
667be appended to the write buffer.
668
669Note that this is a function, and all types registered this way will be
670global, so try to use unique names.
671
672=cut
673
322############################################################################# 674#############################################################################
323 675
324=back 676=back
325 677
326=head2 READ QUEUE 678=head2 READ QUEUE
332ways, 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
333a queue. 685a queue.
334 686
335In 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
336new 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
337enough 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
338or not. 690leave the data there if you want to accumulate more (e.g. when only a
691partial message has been received so far).
339 692
340In 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
341case, AnyEvent::Handle will call the first queued callback each time new 694case, AnyEvent::Handle will call the first queued callback each time new
342data arrives and removes it when it has done its job (see C<push_read>, 695data arrives (also the first time it is queued) and removes it when it has
343below). 696done its job (see C<push_read>, below).
344 697
345This way you can, for example, push three line-reads, followed by reading 698This way you can, for example, push three line-reads, followed by reading
346a chunk of data, and AnyEvent::Handle will execute them in order. 699a chunk of data, and AnyEvent::Handle will execute them in order.
347 700
348Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 701Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
349the specified number of bytes which give an XML datagram. 702the specified number of bytes which give an XML datagram.
350 703
351 # in the default state, expect some header bytes 704 # in the default state, expect some header bytes
352 $handle->on_read (sub { 705 $handle->on_read (sub {
353 # some data is here, now queue the length-header-read (4 octets) 706 # some data is here, now queue the length-header-read (4 octets)
354 shift->unshift_read_chunk (4, sub { 707 shift->unshift_read (chunk => 4, sub {
355 # header arrived, decode 708 # header arrived, decode
356 my $len = unpack "N", $_[1]; 709 my $len = unpack "N", $_[1];
357 710
358 # now read the payload 711 # now read the payload
359 shift->unshift_read_chunk ($len, sub { 712 shift->unshift_read (chunk => $len, sub {
360 my $xml = $_[1]; 713 my $xml = $_[1];
361 # handle xml 714 # handle xml
362 }); 715 });
363 }); 716 });
364 }); 717 });
365 718
366Example 2: Implement a client for a protocol that replies either with 719Example 2: Implement a client for a protocol that replies either with "OK"
367"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
368second 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
369pipeline sending both requests and manipulate the queue as necessary in 722just pipeline sending both requests and manipulate the queue as necessary
370the callbacks: 723in the callbacks.
371 724
372 # 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"
373 $handle->push_write ("request 1\015\012"); 730 $handle->push_write ("request 1\015\012");
374 731
375 # 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
376 $handle->push_read_line (sub { 733 $handle->push_read (line => sub {
377 # if we got an "OK", we have to _prepend_ another line, 734 # if we got an "OK", we have to _prepend_ another line,
378 # so it will be read before the second request reads its 64 bytes 735 # so it will be read before the second request reads its 64 bytes
379 # which are already in the queue when this callback is called 736 # which are already in the queue when this callback is called
380 # we don't do this in case we got an error 737 # we don't do this in case we got an error
381 if ($_[1] eq "OK") { 738 if ($_[1] eq "OK") {
382 $_[0]->unshift_read_line (sub { 739 $_[0]->unshift_read (line => sub {
383 my $response = $_[1]; 740 my $response = $_[1];
384 ... 741 ...
385 }); 742 });
386 } 743 }
387 }); 744 });
388 745
389 # request two 746 # request two, simply returns 64 octets
390 $handle->push_write ("request 2\015\012"); 747 $handle->push_write ("request 2\015\012");
391 748
392 # simply read 64 bytes, always 749 # simply read 64 bytes, always
393 $handle->push_read_chunk (64, sub { 750 $handle->push_read (chunk => 64, sub {
394 my $response = $_[1]; 751 my $response = $_[1];
395 ... 752 ...
396 }); 753 });
397 754
398=over 4 755=over 4
399 756
400=cut 757=cut
401 758
402sub _drain_rbuf { 759sub _drain_rbuf {
403 my ($self) = @_; 760 my ($self) = @_;
761
762 local $self->{_in_drain} = 1;
404 763
405 if ( 764 if (
406 defined $self->{rbuf_max} 765 defined $self->{rbuf_max}
407 && $self->{rbuf_max} < length $self->{rbuf} 766 && $self->{rbuf_max} < length $self->{rbuf}
408 ) { 767 ) {
409 $! = &Errno::ENOSPC; return $self->error; 768 $self->_error (&Errno::ENOSPC, 1), return;
410 } 769 }
411 770
412 return if $self->{in_drain}; 771 while () {
413 local $self->{in_drain} = 1; 772 $self->{rbuf} .= delete $self->{tls_rbuf} if exists $self->{tls_rbuf};#d#
414 773
415 while (my $len = length $self->{rbuf}) { 774 my $len = length $self->{rbuf};
416 no strict 'refs'; 775
417 if (my $cb = shift @{ $self->{queue} }) { 776 if (my $cb = shift @{ $self->{_queue} }) {
418 if (!$cb->($self)) { 777 unless ($cb->($self)) {
419 if ($self->{eof}) { 778 if ($self->{_eof}) {
420 # no progress can be made (not enough data and no data forthcoming) 779 # no progress can be made (not enough data and no data forthcoming)
421 $! = &Errno::EPIPE; return $self->error; 780 $self->_error (&Errno::EPIPE, 1), return;
422 } 781 }
423 782
424 unshift @{ $self->{queue} }, $cb; 783 unshift @{ $self->{_queue} }, $cb;
425 return; 784 last;
426 } 785 }
427 } elsif ($self->{on_read}) { 786 } elsif ($self->{on_read}) {
787 last unless $len;
788
428 $self->{on_read}($self); 789 $self->{on_read}($self);
429 790
430 if ( 791 if (
431 $self->{eof} # if no further data will arrive
432 && $len == length $self->{rbuf} # and no data has been consumed 792 $len == length $self->{rbuf} # if no data has been consumed
433 && !@{ $self->{queue} } # and the queue is still empty 793 && !@{ $self->{_queue} } # and the queue is still empty
434 && $self->{on_read} # and we still want to read data 794 && $self->{on_read} # but we still have on_read
435 ) { 795 ) {
796 # no further data will arrive
436 # then no progress can be made 797 # so no progress can be made
437 $! = &Errno::EPIPE; return $self->error; 798 $self->_error (&Errno::EPIPE, 1), return
799 if $self->{_eof};
800
801 last; # more data might arrive
438 } 802 }
439 } else { 803 } else {
440 # read side becomes idle 804 # read side becomes idle
441 delete $self->{rw}; 805 delete $self->{_rw} unless $self->{tls};
442 return; 806 last;
443 } 807 }
444 } 808 }
445 809
446 if ($self->{eof}) { 810 if ($self->{_eof}) {
447 $self->_shutdown; 811 if ($self->{on_eof}) {
448 $self->{on_eof}($self) 812 $self->{on_eof}($self)
449 if $self->{on_eof}; 813 } else {
814 $self->_error (0, 1);
815 }
816 }
817
818 # may need to restart read watcher
819 unless ($self->{_rw}) {
820 $self->start_read
821 if $self->{on_read} || @{ $self->{_queue} };
450 } 822 }
451} 823}
452 824
453=item $handle->on_read ($cb) 825=item $handle->on_read ($cb)
454 826
460 832
461sub on_read { 833sub on_read {
462 my ($self, $cb) = @_; 834 my ($self, $cb) = @_;
463 835
464 $self->{on_read} = $cb; 836 $self->{on_read} = $cb;
837 $self->_drain_rbuf if $cb && !$self->{_in_drain};
465} 838}
466 839
467=item $handle->rbuf 840=item $handle->rbuf
468 841
469Returns the read buffer (as a modifiable lvalue). 842Returns the read buffer (as a modifiable lvalue).
500interested in (which can be none at all) and return a true value. After returning 873interested in (which can be none at all) and return a true value. After returning
501true, it will be removed from the queue. 874true, it will be removed from the queue.
502 875
503=cut 876=cut
504 877
878our %RH;
879
880sub register_read_type($$) {
881 $RH{$_[0]} = $_[1];
882}
883
505sub push_read { 884sub push_read {
506 my ($self, $cb) = @_; 885 my $self = shift;
886 my $cb = pop;
507 887
888 if (@_) {
889 my $type = shift;
890
891 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
892 ->($self, $cb, @_);
893 }
894
508 push @{ $self->{queue} }, $cb; 895 push @{ $self->{_queue} }, $cb;
509 $self->_drain_rbuf; 896 $self->_drain_rbuf unless $self->{_in_drain};
510} 897}
511 898
512sub unshift_read { 899sub unshift_read {
513 my ($self, $cb) = @_; 900 my $self = shift;
901 my $cb = pop;
514 902
903 if (@_) {
904 my $type = shift;
905
906 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
907 ->($self, $cb, @_);
908 }
909
910
515 push @{ $self->{queue} }, $cb; 911 unshift @{ $self->{_queue} }, $cb;
516 $self->_drain_rbuf; 912 $self->_drain_rbuf unless $self->{_in_drain};
517} 913}
518 914
519=item $handle->push_read_chunk ($len, $cb->($self, $data)) 915=item $handle->push_read (type => @args, $cb)
520 916
521=item $handle->unshift_read_chunk ($len, $cb->($self, $data)) 917=item $handle->unshift_read (type => @args, $cb)
522 918
523Append the given callback to the end of the queue (C<push_read_chunk>) or 919Instead of providing a callback that parses the data itself you can chose
524prepend it (C<unshift_read_chunk>). 920between a number of predefined parsing formats, for chunks of data, lines
921etc.
525 922
526The callback will be called only once C<$len> bytes have been read, and 923Predefined types are (if you have ideas for additional types, feel free to
527these C<$len> bytes will be passed to the callback. 924drop by and tell us):
528 925
529=cut 926=over 4
530 927
531sub _read_chunk($$) { 928=item chunk => $octets, $cb->($handle, $data)
929
930Invoke the callback only once C<$octets> bytes have been read. Pass the
931data read to the callback. The callback will never be called with less
932data.
933
934Example: read 2 bytes.
935
936 $handle->push_read (chunk => 2, sub {
937 warn "yay ", unpack "H*", $_[1];
938 });
939
940=cut
941
942register_read_type chunk => sub {
532 my ($self, $len, $cb) = @_; 943 my ($self, $cb, $len) = @_;
533 944
534 sub { 945 sub {
535 $len <= length $_[0]{rbuf} or return; 946 $len <= length $_[0]{rbuf} or return;
536 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 947 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
537 1 948 1
538 } 949 }
539} 950};
540 951
541sub push_read_chunk { 952=item line => [$eol, ]$cb->($handle, $line, $eol)
542 $_[0]->push_read (&_read_chunk);
543}
544
545
546sub unshift_read_chunk {
547 $_[0]->unshift_read (&_read_chunk);
548}
549
550=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
551
552=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
553
554Append the given callback to the end of the queue (C<push_read_line>) or
555prepend it (C<unshift_read_line>).
556 953
557The callback will be called only once a full line (including the end of 954The callback will be called only once a full line (including the end of
558line marker, C<$eol>) has been read. This line (excluding the end of line 955line marker, C<$eol>) has been read. This line (excluding the end of line
559marker) will be passed to the callback as second argument (C<$line>), and 956marker) will be passed to the callback as second argument (C<$line>), and
560the end of line marker as the third argument (C<$eol>). 957the end of line marker as the third argument (C<$eol>).
571Partial lines at the end of the stream will never be returned, as they are 968Partial lines at the end of the stream will never be returned, as they are
572not marked by the end of line marker. 969not marked by the end of line marker.
573 970
574=cut 971=cut
575 972
576sub _read_line($$) { 973register_read_type line => sub {
577 my $self = shift; 974 my ($self, $cb, $eol) = @_;
578 my $cb = pop;
579 my $eol = @_ ? shift : qr|(\015?\012)|;
580 my $pos;
581 975
976 if (@_ < 3) {
977 # this is more than twice as fast as the generic code below
978 sub {
979 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
980
981 $cb->($_[0], $1, $2);
982 1
983 }
984 } else {
582 $eol = quotemeta $eol unless ref $eol; 985 $eol = quotemeta $eol unless ref $eol;
583 $eol = qr|^(.*?)($eol)|s; 986 $eol = qr|^(.*?)($eol)|s;
987
988 sub {
989 $_[0]{rbuf} =~ s/$eol// or return;
990
991 $cb->($_[0], $1, $2);
992 1
993 }
994 }
995};
996
997=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
998
999Makes a regex match against the regex object C<$accept> and returns
1000everything up to and including the match.
1001
1002Example: read a single line terminated by '\n'.
1003
1004 $handle->push_read (regex => qr<\n>, sub { ... });
1005
1006If C<$reject> is given and not undef, then it determines when the data is
1007to be rejected: it is matched against the data when the C<$accept> regex
1008does not match and generates an C<EBADMSG> error when it matches. This is
1009useful to quickly reject wrong data (to avoid waiting for a timeout or a
1010receive buffer overflow).
1011
1012Example: expect a single decimal number followed by whitespace, reject
1013anything else (not the use of an anchor).
1014
1015 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1016
1017If C<$skip> is given and not C<undef>, then it will be matched against
1018the receive buffer when neither C<$accept> nor C<$reject> match,
1019and everything preceding and including the match will be accepted
1020unconditionally. This is useful to skip large amounts of data that you
1021know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1022have to start matching from the beginning. This is purely an optimisation
1023and is usually worth only when you expect more than a few kilobytes.
1024
1025Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1026expect the header to be very large (it isn't in practise, but...), we use
1027a skip regex to skip initial portions. The skip regex is tricky in that
1028it only accepts something not ending in either \015 or \012, as these are
1029required for the accept regex.
1030
1031 $handle->push_read (regex =>
1032 qr<\015\012\015\012>,
1033 undef, # no reject
1034 qr<^.*[^\015\012]>,
1035 sub { ... });
1036
1037=cut
1038
1039register_read_type regex => sub {
1040 my ($self, $cb, $accept, $reject, $skip) = @_;
1041
1042 my $data;
1043 my $rbuf = \$self->{rbuf};
584 1044
585 sub { 1045 sub {
586 $_[0]{rbuf} =~ s/$eol// or return; 1046 # accept
1047 if ($$rbuf =~ $accept) {
1048 $data .= substr $$rbuf, 0, $+[0], "";
1049 $cb->($self, $data);
1050 return 1;
1051 }
1052
1053 # reject
1054 if ($reject && $$rbuf =~ $reject) {
1055 $self->_error (&Errno::EBADMSG);
1056 }
587 1057
588 $cb->($_[0], $1, $2); 1058 # skip
1059 if ($skip && $$rbuf =~ $skip) {
1060 $data .= substr $$rbuf, 0, $+[0], "";
1061 }
1062
1063 ()
1064 }
1065};
1066
1067=item netstring => $cb->($handle, $string)
1068
1069A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1070
1071Throws an error with C<$!> set to EBADMSG on format violations.
1072
1073=cut
1074
1075register_read_type netstring => sub {
1076 my ($self, $cb) = @_;
1077
1078 sub {
1079 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1080 if ($_[0]{rbuf} =~ /[^0-9]/) {
1081 $self->_error (&Errno::EBADMSG);
1082 }
1083 return;
1084 }
1085
1086 my $len = $1;
1087
1088 $self->unshift_read (chunk => $len, sub {
1089 my $string = $_[1];
1090 $_[0]->unshift_read (chunk => 1, sub {
1091 if ($_[1] eq ",") {
1092 $cb->($_[0], $string);
1093 } else {
1094 $self->_error (&Errno::EBADMSG);
1095 }
1096 });
1097 });
1098
589 1 1099 1
590 } 1100 }
591} 1101};
592 1102
593sub push_read_line { 1103=item packstring => $format, $cb->($handle, $string)
594 $_[0]->push_read (&_read_line);
595}
596 1104
597sub unshift_read_line { 1105An octet string prefixed with an encoded length. The encoding C<$format>
598 $_[0]->unshift_read (&_read_line); 1106uses the same format as a Perl C<pack> format, but must specify a single
599} 1107integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1108optional C<!>, C<< < >> or C<< > >> modifier).
1109
1110For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1111EPP uses a prefix of C<N> (4 octtes).
1112
1113Example: read a block of data prefixed by its length in BER-encoded
1114format (very efficient).
1115
1116 $handle->push_read (packstring => "w", sub {
1117 my ($handle, $data) = @_;
1118 });
1119
1120=cut
1121
1122register_read_type packstring => sub {
1123 my ($self, $cb, $format) = @_;
1124
1125 sub {
1126 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1127 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1128 or return;
1129
1130 $format = length pack $format, $len;
1131
1132 # bypass unshift if we already have the remaining chunk
1133 if ($format + $len <= length $_[0]{rbuf}) {
1134 my $data = substr $_[0]{rbuf}, $format, $len;
1135 substr $_[0]{rbuf}, 0, $format + $len, "";
1136 $cb->($_[0], $data);
1137 } else {
1138 # remove prefix
1139 substr $_[0]{rbuf}, 0, $format, "";
1140
1141 # read remaining chunk
1142 $_[0]->unshift_read (chunk => $len, $cb);
1143 }
1144
1145 1
1146 }
1147};
1148
1149=item json => $cb->($handle, $hash_or_arrayref)
1150
1151Reads a JSON object or array, decodes it and passes it to the
1152callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1153
1154If a C<json> object was passed to the constructor, then that will be used
1155for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1156
1157This read type uses the incremental parser available with JSON version
11582.09 (and JSON::XS version 2.2) and above. You have to provide a
1159dependency on your own: this module will load the JSON module, but
1160AnyEvent does not depend on it itself.
1161
1162Since JSON texts are fully self-delimiting, the C<json> read and write
1163types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1164the C<json> write type description, above, for an actual example.
1165
1166=cut
1167
1168register_read_type json => sub {
1169 my ($self, $cb) = @_;
1170
1171 require JSON;
1172
1173 my $data;
1174 my $rbuf = \$self->{rbuf};
1175
1176 my $json = $self->{json} ||= JSON->new->utf8;
1177
1178 sub {
1179 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1180
1181 if ($ref) {
1182 $self->{rbuf} = $json->incr_text;
1183 $json->incr_text = "";
1184 $cb->($self, $ref);
1185
1186 1
1187 } elsif ($@) {
1188 # error case
1189 $json->incr_skip;
1190
1191 $self->{rbuf} = $json->incr_text;
1192 $json->incr_text = "";
1193
1194 $self->_error (&Errno::EBADMSG);
1195
1196 ()
1197 } else {
1198 $self->{rbuf} = "";
1199
1200 ()
1201 }
1202 }
1203};
1204
1205=item storable => $cb->($handle, $ref)
1206
1207Deserialises a L<Storable> frozen representation as written by the
1208C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1209data).
1210
1211Raises C<EBADMSG> error if the data could not be decoded.
1212
1213=cut
1214
1215register_read_type storable => sub {
1216 my ($self, $cb) = @_;
1217
1218 require Storable;
1219
1220 sub {
1221 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1222 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1223 or return;
1224
1225 my $format = length pack "w", $len;
1226
1227 # bypass unshift if we already have the remaining chunk
1228 if ($format + $len <= length $_[0]{rbuf}) {
1229 my $data = substr $_[0]{rbuf}, $format, $len;
1230 substr $_[0]{rbuf}, 0, $format + $len, "";
1231 $cb->($_[0], Storable::thaw ($data));
1232 } else {
1233 # remove prefix
1234 substr $_[0]{rbuf}, 0, $format, "";
1235
1236 # read remaining chunk
1237 $_[0]->unshift_read (chunk => $len, sub {
1238 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1239 $cb->($_[0], $ref);
1240 } else {
1241 $self->_error (&Errno::EBADMSG);
1242 }
1243 });
1244 }
1245
1246 1
1247 }
1248};
1249
1250=back
1251
1252=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
1253
1254This function (not method) lets you add your own types to C<push_read>.
1255
1256Whenever the given C<type> is used, C<push_read> will invoke the code
1257reference with the handle object, the callback and the remaining
1258arguments.
1259
1260The code reference is supposed to return a callback (usually a closure)
1261that works as a plain read callback (see C<< ->push_read ($cb) >>).
1262
1263It should invoke the passed callback when it is done reading (remember to
1264pass C<$handle> as first argument as all other callbacks do that).
1265
1266Note that this is a function, and all types registered this way will be
1267global, so try to use unique names.
1268
1269For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
1270search for C<register_read_type>)).
600 1271
601=item $handle->stop_read 1272=item $handle->stop_read
602 1273
603=item $handle->start_read 1274=item $handle->start_read
604 1275
605In rare cases you actually do not want to read anything from the 1276In rare cases you actually do not want to read anything from the
606socket. In this case you can call C<stop_read>. Neither C<on_read> no 1277socket. In this case you can call C<stop_read>. Neither C<on_read> nor
607any queued callbacks will be executed then. To start reading again, call 1278any queued callbacks will be executed then. To start reading again, call
608C<start_read>. 1279C<start_read>.
609 1280
1281Note that AnyEvent::Handle will automatically C<start_read> for you when
1282you change the C<on_read> callback or push/unshift a read callback, and it
1283will automatically C<stop_read> for you when neither C<on_read> is set nor
1284there are any read requests in the queue.
1285
1286These methods will have no effect when in TLS mode (as TLS doesn't support
1287half-duplex connections).
1288
610=cut 1289=cut
611 1290
612sub stop_read { 1291sub stop_read {
613 my ($self) = @_; 1292 my ($self) = @_;
614 1293
615 delete $self->{rw}; 1294 delete $self->{_rw} unless $self->{tls};
616} 1295}
617 1296
618sub start_read { 1297sub start_read {
619 my ($self) = @_; 1298 my ($self) = @_;
620 1299
621 unless ($self->{rw} || $self->{eof}) { 1300 unless ($self->{_rw} || $self->{_eof}) {
622 Scalar::Util::weaken $self; 1301 Scalar::Util::weaken $self;
623 1302
624 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1303 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
625 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1304 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
626 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1305 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
627 1306
628 if ($len > 0) { 1307 if ($len > 0) {
629 $self->{filter_r} 1308 $self->{_activity} = AnyEvent->now;
630 ? $self->{filter_r}->($self, $rbuf) 1309
631 : $self->_drain_rbuf; 1310 if ($self->{tls}) {
1311 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1312
1313 &_dotls ($self);
1314 } else {
1315 $self->_drain_rbuf unless $self->{_in_drain};
1316 }
632 1317
633 } elsif (defined $len) { 1318 } elsif (defined $len) {
634 delete $self->{rw}; 1319 delete $self->{_rw};
635 $self->{eof} = 1; 1320 $self->{_eof} = 1;
636 $self->_drain_rbuf; 1321 $self->_drain_rbuf unless $self->{_in_drain};
637 1322
638 } elsif ($! != EAGAIN && $! != EINTR) { 1323 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
639 return $self->error; 1324 return $self->_error ($!, 1);
640 } 1325 }
641 }); 1326 });
642 } 1327 }
643} 1328}
644 1329
1330# poll the write BIO and send the data if applicable
645sub _dotls { 1331sub _dotls {
646 my ($self) = @_; 1332 my ($self) = @_;
647 1333
1334 my $tmp;
1335
648 if (length $self->{tls_wbuf}) { 1336 if (length $self->{_tls_wbuf}) {
649 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1337 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
650 substr $self->{tls_wbuf}, 0, $len, ""; 1338 substr $self->{_tls_wbuf}, 0, $tmp, "";
651 } 1339 }
652 } 1340 }
653 1341
654 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1342 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1343 unless (length $tmp) {
1344 # let's treat SSL-eof as we treat normal EOF
1345 delete $self->{_rw};
1346 $self->{_eof} = 1;
1347 &_freetls;
1348 }
1349
1350 $self->{tls_rbuf} .= $tmp;#d#
1351 $self->_drain_rbuf unless $self->{_in_drain};
1352 $self->{tls} or return; # tls session might have gone away in callback
1353 }
1354
1355 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1356
1357 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1358 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1359 return $self->_error ($!, 1);
1360 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1361 return $self->_error (&Errno::EIO, 1);
1362 }
1363
1364 # all other errors are fine for our purposes
1365 }
1366
1367 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
655 $self->{wbuf} .= $buf; 1368 $self->{wbuf} .= $tmp;
656 $self->_drain_wbuf; 1369 $self->_drain_wbuf;
657 } 1370 }
658
659 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
660 $self->{rbuf} .= $buf;
661 $self->_drain_rbuf;
662 }
663
664 if (
665 (my $err = Net::SSLeay::get_error ($self->{tls}, -1))
666 != Net::SSLeay::ERROR_WANT_READ ()
667 ) {
668 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
669 $self->error;
670 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
671 $! = &Errno::EIO;
672 $self->error;
673 }
674
675 # all others are fine for our purposes
676 }
677} 1371}
678 1372
679# TODO: maybe document... 1373=item $handle->starttls ($tls[, $tls_ctx])
1374
1375Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1376object is created, you can also do that at a later time by calling
1377C<starttls>.
1378
1379The first argument is the same as the C<tls> constructor argument (either
1380C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1381
1382The second argument is the optional C<Net::SSLeay::CTX> object that is
1383used when AnyEvent::Handle has to create its own TLS connection object.
1384
1385The TLS connection object will end up in C<< $handle->{tls} >> after this
1386call and can be used or changed to your liking. Note that the handshake
1387might have already started when this function returns.
1388
1389If it an error to start a TLS handshake more than once per
1390AnyEvent::Handle object (this is due to bugs in OpenSSL).
1391
1392=cut
1393
680sub starttls { 1394sub starttls {
681 my ($self, $ssl, $ctx) = @_; 1395 my ($self, $ssl, $ctx) = @_;
682 1396
1397 require Net::SSLeay;
1398
1399 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1400 if $self->{tls};
1401
683 if ($ssl eq "accept") { 1402 if ($ssl eq "accept") {
684 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1403 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
685 Net::SSLeay::set_accept_state ($ssl); 1404 Net::SSLeay::set_accept_state ($ssl);
686 } elsif ($ssl eq "connect") { 1405 } elsif ($ssl eq "connect") {
687 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1406 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
692 1411
693 # basically, this is deep magic (because SSL_read should have the same issues) 1412 # basically, this is deep magic (because SSL_read should have the same issues)
694 # but the openssl maintainers basically said: "trust us, it just works". 1413 # but the openssl maintainers basically said: "trust us, it just works".
695 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1414 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
696 # and mismaintained ssleay-module doesn't even offer them). 1415 # and mismaintained ssleay-module doesn't even offer them).
1416 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1417 #
1418 # in short: this is a mess.
1419 #
1420 # note that we do not try to keep the length constant between writes as we are required to do.
1421 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1422 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1423 # have identity issues in that area.
697 Net::SSLeay::CTX_set_mode ($self->{tls}, 1424 Net::SSLeay::CTX_set_mode ($self->{tls},
698 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1425 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
699 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1426 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
700 1427
701 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1428 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
702 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
703 1430
704 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1431 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
705 1432
706 $self->{filter_w} = sub { 1433 &_dotls; # need to trigger the initial handshake
707 $_[0]{tls_wbuf} .= ${$_[1]}; 1434 $self->start_read; # make sure we actually do read
1435}
1436
1437=item $handle->stoptls
1438
1439Shuts down the SSL connection - this makes a proper EOF handshake by
1440sending a close notify to the other side, but since OpenSSL doesn't
1441support non-blocking shut downs, it is not possible to re-use the stream
1442afterwards.
1443
1444=cut
1445
1446sub stoptls {
1447 my ($self) = @_;
1448
1449 if ($self->{tls}) {
1450 Net::SSLeay::shutdown ($self->{tls});
1451
708 &_dotls; 1452 &_dotls;
1453
1454 # we don't give a shit. no, we do, but we can't. no...
1455 # we, we... have to use openssl :/
1456 &_freetls;
709 }; 1457 }
710 $self->{filter_r} = sub { 1458}
711 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]}); 1459
712 &_dotls; 1460sub _freetls {
1461 my ($self) = @_;
1462
1463 return unless $self->{tls};
1464
1465 Net::SSLeay::free (delete $self->{tls});
713 }; 1466
1467 delete @$self{qw(_rbio _wbio _tls_wbuf)};
714} 1468}
715 1469
716sub DESTROY { 1470sub DESTROY {
717 my $self = shift; 1471 my $self = shift;
718 1472
719 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1473 &_freetls;
1474
1475 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1476
1477 if ($linger && length $self->{wbuf}) {
1478 my $fh = delete $self->{fh};
1479 my $wbuf = delete $self->{wbuf};
1480
1481 my @linger;
1482
1483 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1484 my $len = syswrite $fh, $wbuf, length $wbuf;
1485
1486 if ($len > 0) {
1487 substr $wbuf, 0, $len, "";
1488 } else {
1489 @linger = (); # end
1490 }
1491 });
1492 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1493 @linger = ();
1494 });
1495 }
1496}
1497
1498=item $handle->destroy
1499
1500Shuts down the handle object as much as possible - this call ensures that
1501no further callbacks will be invoked and resources will be freed as much
1502as possible. You must not call any methods on the object afterwards.
1503
1504Normally, you can just "forget" any references to an AnyEvent::Handle
1505object and it will simply shut down. This works in fatal error and EOF
1506callbacks, as well as code outside. It does I<NOT> work in a read or write
1507callback, so when you want to destroy the AnyEvent::Handle object from
1508within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1509that case.
1510
1511The handle might still linger in the background and write out remaining
1512data, as specified by the C<linger> option, however.
1513
1514=cut
1515
1516sub destroy {
1517 my ($self) = @_;
1518
1519 $self->DESTROY;
1520 %$self = ();
720} 1521}
721 1522
722=item AnyEvent::Handle::TLS_CTX 1523=item AnyEvent::Handle::TLS_CTX
723 1524
724This function creates and returns the Net::SSLeay::CTX object used by 1525This function creates and returns the Net::SSLeay::CTX object used by
754 } 1555 }
755} 1556}
756 1557
757=back 1558=back
758 1559
1560
1561=head1 NONFREQUENTLY ASKED QUESTIONS
1562
1563=over 4
1564
1565=item I C<undef> the AnyEvent::Handle reference inside my callback and
1566still get further invocations!
1567
1568That's because AnyEvent::Handle keeps a reference to itself when handling
1569read or write callbacks.
1570
1571It is only safe to "forget" the reference inside EOF or error callbacks,
1572from within all other callbacks, you need to explicitly call the C<<
1573->destroy >> method.
1574
1575=item I get different callback invocations in TLS mode/Why can't I pause
1576reading?
1577
1578Unlike, say, TCP, TLS connections do not consist of two independent
1579communication channels, one for each direction. Or put differently. The
1580read and write directions are not independent of each other: you cannot
1581write data unless you are also prepared to read, and vice versa.
1582
1583This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1584callback invocations when you are not expecting any read data - the reason
1585is that AnyEvent::Handle always reads in TLS mode.
1586
1587During the connection, you have to make sure that you always have a
1588non-empty read-queue, or an C<on_read> watcher. At the end of the
1589connection (or when you no longer want to use it) you can call the
1590C<destroy> method.
1591
1592=item How do I read data until the other side closes the connection?
1593
1594If you just want to read your data into a perl scalar, the easiest way
1595to achieve this is by setting an C<on_read> callback that does nothing,
1596clearing the C<on_eof> callback and in the C<on_error> callback, the data
1597will be in C<$_[0]{rbuf}>:
1598
1599 $handle->on_read (sub { });
1600 $handle->on_eof (undef);
1601 $handle->on_error (sub {
1602 my $data = delete $_[0]{rbuf};
1603 undef $handle;
1604 });
1605
1606The reason to use C<on_error> is that TCP connections, due to latencies
1607and packets loss, might get closed quite violently with an error, when in
1608fact, all data has been received.
1609
1610It is usually better to use acknowledgements when transferring data,
1611to make sure the other side hasn't just died and you got the data
1612intact. This is also one reason why so many internet protocols have an
1613explicit QUIT command.
1614
1615=item I don't want to destroy the handle too early - how do I wait until
1616all data has been written?
1617
1618After writing your last bits of data, set the C<on_drain> callback
1619and destroy the handle in there - with the default setting of
1620C<low_water_mark> this will be called precisely when all data has been
1621written to the socket:
1622
1623 $handle->push_write (...);
1624 $handle->on_drain (sub {
1625 warn "all data submitted to the kernel\n";
1626 undef $handle;
1627 });
1628
1629=back
1630
1631
1632=head1 SUBCLASSING AnyEvent::Handle
1633
1634In many cases, you might want to subclass AnyEvent::Handle.
1635
1636To make this easier, a given version of AnyEvent::Handle uses these
1637conventions:
1638
1639=over 4
1640
1641=item * all constructor arguments become object members.
1642
1643At least initially, when you pass a C<tls>-argument to the constructor it
1644will end up in C<< $handle->{tls} >>. Those members might be changed or
1645mutated later on (for example C<tls> will hold the TLS connection object).
1646
1647=item * other object member names are prefixed with an C<_>.
1648
1649All object members not explicitly documented (internal use) are prefixed
1650with an underscore character, so the remaining non-C<_>-namespace is free
1651for use for subclasses.
1652
1653=item * all members not documented here and not prefixed with an underscore
1654are free to use in subclasses.
1655
1656Of course, new versions of AnyEvent::Handle may introduce more "public"
1657member variables, but thats just life, at least it is documented.
1658
1659=back
1660
759=head1 AUTHOR 1661=head1 AUTHOR
760 1662
761Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1663Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
762 1664
763=cut 1665=cut

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