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Revision 1.31 by root, Sun May 25 00:08:49 2008 UTC vs.
Revision 1.93 by root, Wed Oct 1 14:49:23 2008 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
17=cut 17=cut
18 18
19our $VERSION = '0.04'; 19our $VERSION = 4.3;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
59argument. 62argument.
60 63
64=head2 SIGPIPE is not handled by this module
65
66SIGPIPE is not handled by this module, so one of the practical
67requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} =
68'IGNORE'>). At least, this is highly recommend in a networked program: If
69you use AnyEvent::Handle in a filter program (like sort), exiting on
70SIGPIPE is probably the right thing to do.
71
61=head1 METHODS 72=head1 METHODS
62 73
63=over 4 74=over 4
64 75
65=item B<new (%args)> 76=item B<new (%args)>
70 81
71=item fh => $filehandle [MANDATORY] 82=item fh => $filehandle [MANDATORY]
72 83
73The filehandle this L<AnyEvent::Handle> object will operate on. 84The filehandle this L<AnyEvent::Handle> object will operate on.
74 85
75NOTE: The filehandle will be set to non-blocking (using 86NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 87C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
88that mode.
77 89
78=item on_eof => $cb->($self) 90=item on_eof => $cb->($handle)
79 91
80Set the callback to be called on EOF. 92Set the callback to be called when an end-of-file condition is detected,
93i.e. in the case of a socket, when the other side has closed the
94connection cleanly.
81 95
96For sockets, this just means that the other side has stopped sending data,
97you can still try to write data, and, in fact, one can return from the eof
98callback and continue writing data, as only the read part has been shut
99down.
100
82While not mandatory, it is highly recommended to set an eof callback, 101While not mandatory, it is I<highly> recommended to set an eof callback,
83otherwise you might end up with a closed socket while you are still 102otherwise you might end up with a closed socket while you are still
84waiting for data. 103waiting for data.
85 104
105If an EOF condition has been detected but no C<on_eof> callback has been
106set, then a fatal error will be raised with C<$!> set to <0>.
107
86=item on_error => $cb->($self) 108=item on_error => $cb->($handle, $fatal)
87 109
88This is the fatal error callback, that is called when, well, a fatal error 110This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 111occured, such as not being able to resolve the hostname, failure to
90or a read error. 112connect or a read error.
91 113
92The object will not be in a usable state when this callback has been 114Some errors are fatal (which is indicated by C<$fatal> being true). On
93called. 115fatal errors the handle object will be shut down and will not be usable
116(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
117errors are an EOF condition with active (but unsatisifable) read watchers
118(C<EPIPE>) or I/O errors.
119
120Non-fatal errors can be retried by simply returning, but it is recommended
121to simply ignore this parameter and instead abondon the handle object
122when this callback is invoked. Examples of non-fatal errors are timeouts
123C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
94 124
95On callback entrance, the value of C<$!> contains the operating system 125On callback entrance, the value of C<$!> contains the operating system
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 126error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
97 127
98While not mandatory, it is I<highly> recommended to set this callback, as 128While not mandatory, it is I<highly> recommended to set this callback, as
99you will not be notified of errors otherwise. The default simply calls 129you will not be notified of errors otherwise. The default simply calls
100die. 130C<croak>.
101 131
102=item on_read => $cb->($self) 132=item on_read => $cb->($handle)
103 133
104This sets the default read callback, which is called when data arrives 134This sets the default read callback, which is called when data arrives
105and no read request is in the queue. 135and no read request is in the queue (unlike read queue callbacks, this
136callback will only be called when at least one octet of data is in the
137read buffer).
106 138
107To access (and remove data from) the read buffer, use the C<< ->rbuf >> 139To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108method or access the C<$self->{rbuf}> member directly. 140method or access the C<$handle->{rbuf}> member directly.
109 141
110When an EOF condition is detected then AnyEvent::Handle will first try to 142When an EOF condition is detected then AnyEvent::Handle will first try to
111feed all the remaining data to the queued callbacks and C<on_read> before 143feed all the remaining data to the queued callbacks and C<on_read> before
112calling the C<on_eof> callback. If no progress can be made, then a fatal 144calling the C<on_eof> callback. If no progress can be made, then a fatal
113error will be raised (with C<$!> set to C<EPIPE>). 145error will be raised (with C<$!> set to C<EPIPE>).
114 146
115=item on_drain => $cb->() 147=item on_drain => $cb->($handle)
116 148
117This sets the callback that is called when the write buffer becomes empty 149This sets the callback that is called when the write buffer becomes empty
118(or when the callback is set and the buffer is empty already). 150(or when the callback is set and the buffer is empty already).
119 151
120To append to the write buffer, use the C<< ->push_write >> method. 152To append to the write buffer, use the C<< ->push_write >> method.
121 153
154This callback is useful when you don't want to put all of your write data
155into the queue at once, for example, when you want to write the contents
156of some file to the socket you might not want to read the whole file into
157memory and push it into the queue, but instead only read more data from
158the file when the write queue becomes empty.
159
160=item timeout => $fractional_seconds
161
162If non-zero, then this enables an "inactivity" timeout: whenever this many
163seconds pass without a successful read or write on the underlying file
164handle, the C<on_timeout> callback will be invoked (and if that one is
165missing, a non-fatal C<ETIMEDOUT> error will be raised).
166
167Note that timeout processing is also active when you currently do not have
168any outstanding read or write requests: If you plan to keep the connection
169idle then you should disable the timout temporarily or ignore the timeout
170in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
171restart the timeout.
172
173Zero (the default) disables this timeout.
174
175=item on_timeout => $cb->($handle)
176
177Called whenever the inactivity timeout passes. If you return from this
178callback, then the timeout will be reset as if some activity had happened,
179so this condition is not fatal in any way.
180
122=item rbuf_max => <bytes> 181=item rbuf_max => <bytes>
123 182
124If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 183If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125when the read buffer ever (strictly) exceeds this size. This is useful to 184when the read buffer ever (strictly) exceeds this size. This is useful to
126avoid denial-of-service attacks. 185avoid some forms of denial-of-service attacks.
127 186
128For example, a server accepting connections from untrusted sources should 187For example, a server accepting connections from untrusted sources should
129be configured to accept only so-and-so much data that it cannot act on 188be configured to accept only so-and-so much data that it cannot act on
130(for example, when expecting a line, an attacker could send an unlimited 189(for example, when expecting a line, an attacker could send an unlimited
131amount of data without a callback ever being called as long as the line 190amount of data without a callback ever being called as long as the line
132isn't finished). 191isn't finished).
133 192
193=item autocork => <boolean>
194
195When disabled (the default), then C<push_write> will try to immediately
196write the data to the handle, if possible. This avoids having to register
197a write watcher and wait for the next event loop iteration, but can
198be inefficient if you write multiple small chunks (on the wire, this
199disadvantage is usually avoided by your kernel's nagle algorithm, see
200C<no_delay>, but this option can save costly syscalls).
201
202When enabled, then writes will always be queued till the next event loop
203iteration. This is efficient when you do many small writes per iteration,
204but less efficient when you do a single write only per iteration (or when
205the write buffer often is full). It also increases write latency.
206
207=item no_delay => <boolean>
208
209When doing small writes on sockets, your operating system kernel might
210wait a bit for more data before actually sending it out. This is called
211the Nagle algorithm, and usually it is beneficial.
212
213In some situations you want as low a delay as possible, which can be
214accomplishd by setting this option to a true value.
215
216The default is your opertaing system's default behaviour (most likely
217enabled), this option explicitly enables or disables it, if possible.
218
134=item read_size => <bytes> 219=item read_size => <bytes>
135 220
136The default read block size (the amount of bytes this module will try to read 221The default read block size (the amount of bytes this module will
137on each [loop iteration). Default: C<4096>. 222try to read during each loop iteration, which affects memory
223requirements). Default: C<8192>.
138 224
139=item low_water_mark => <bytes> 225=item low_water_mark => <bytes>
140 226
141Sets the amount of bytes (default: C<0>) that make up an "empty" write 227Sets the amount of bytes (default: C<0>) that make up an "empty" write
142buffer: If the write reaches this size or gets even samller it is 228buffer: If the write reaches this size or gets even samller it is
143considered empty. 229considered empty.
144 230
231Sometimes it can be beneficial (for performance reasons) to add data to
232the write buffer before it is fully drained, but this is a rare case, as
233the operating system kernel usually buffers data as well, so the default
234is good in almost all cases.
235
236=item linger => <seconds>
237
238If non-zero (default: C<3600>), then the destructor of the
239AnyEvent::Handle object will check whether there is still outstanding
240write data and will install a watcher that will write this data to the
241socket. No errors will be reported (this mostly matches how the operating
242system treats outstanding data at socket close time).
243
244This will not work for partial TLS data that could not be encoded
245yet. This data will be lost. Calling the C<stoptls> method in time might
246help.
247
145=item tls => "accept" | "connect" | Net::SSLeay::SSL object 248=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146 249
147When this parameter is given, it enables TLS (SSL) mode, that means it 250When this parameter is given, it enables TLS (SSL) mode, that means
148will start making tls handshake and will transparently encrypt/decrypt 251AnyEvent will start a TLS handshake as soon as the conenction has been
149data. 252established and will transparently encrypt/decrypt data afterwards.
150 253
151TLS mode requires Net::SSLeay to be installed (it will be loaded 254TLS mode requires Net::SSLeay to be installed (it will be loaded
152automatically when you try to create a TLS handle). 255automatically when you try to create a TLS handle): this module doesn't
256have a dependency on that module, so if your module requires it, you have
257to add the dependency yourself.
153 258
154For the TLS server side, use C<accept>, and for the TLS client side of a 259Unlike TCP, TLS has a server and client side: for the TLS server side, use
155connection, use C<connect> mode. 260C<accept>, and for the TLS client side of a connection, use C<connect>
261mode.
156 262
157You can also provide your own TLS connection object, but you have 263You can also provide your own TLS connection object, but you have
158to make sure that you call either C<Net::SSLeay::set_connect_state> 264to make sure that you call either C<Net::SSLeay::set_connect_state>
159or C<Net::SSLeay::set_accept_state> on it before you pass it to 265or C<Net::SSLeay::set_accept_state> on it before you pass it to
160AnyEvent::Handle. 266AnyEvent::Handle.
161 267
162See the C<starttls> method if you need to start TLs negotiation later. 268See the C<< ->starttls >> method for when need to start TLS negotiation later.
163 269
164=item tls_ctx => $ssl_ctx 270=item tls_ctx => $ssl_ctx
165 271
166Use the given Net::SSLeay::CTX object to create the new TLS connection 272Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
167(unless a connection object was specified directly). If this parameter is 273(unless a connection object was specified directly). If this parameter is
168missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 274missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
275
276=item json => JSON or JSON::XS object
277
278This is the json coder object used by the C<json> read and write types.
279
280If you don't supply it, then AnyEvent::Handle will create and use a
281suitable one (on demand), which will write and expect UTF-8 encoded JSON
282texts.
283
284Note that you are responsible to depend on the JSON module if you want to
285use this functionality, as AnyEvent does not have a dependency itself.
169 286
170=back 287=back
171 288
172=cut 289=cut
173 290
183 if ($self->{tls}) { 300 if ($self->{tls}) {
184 require Net::SSLeay; 301 require Net::SSLeay;
185 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 302 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
186 } 303 }
187 304
188 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 305 $self->{_activity} = AnyEvent->now;
189 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 306 $self->_timeout;
307
190 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 308 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
191 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 309 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
192 310
193 $self->start_read; 311 $self->start_read
312 if $self->{on_read};
194 313
195 $self 314 $self
196} 315}
197 316
198sub _shutdown { 317sub _shutdown {
199 my ($self) = @_; 318 my ($self) = @_;
200 319
320 delete $self->{_tw};
201 delete $self->{rw}; 321 delete $self->{_rw};
202 delete $self->{ww}; 322 delete $self->{_ww};
203 delete $self->{fh}; 323 delete $self->{fh};
204}
205 324
325 &_freetls;
326
327 delete $self->{on_read};
328 delete $self->{_queue};
329}
330
206sub error { 331sub _error {
207 my ($self) = @_; 332 my ($self, $errno, $fatal) = @_;
208 333
209 {
210 local $!;
211 $self->_shutdown; 334 $self->_shutdown
212 } 335 if $fatal;
336
337 $! = $errno;
213 338
214 if ($self->{on_error}) { 339 if ($self->{on_error}) {
215 $self->{on_error}($self); 340 $self->{on_error}($self, $fatal);
216 } else { 341 } else {
217 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 342 Carp::croak "AnyEvent::Handle uncaught error: $!";
218 } 343 }
219} 344}
220 345
221=item $fh = $handle->fh 346=item $fh = $handle->fh
222 347
223This method returns the file handle of the L<AnyEvent::Handle> object. 348This method returns the file handle used to create the L<AnyEvent::Handle> object.
224 349
225=cut 350=cut
226 351
227sub fh { $_[0]->{fh} } 352sub fh { $_[0]{fh} }
228 353
229=item $handle->on_error ($cb) 354=item $handle->on_error ($cb)
230 355
231Replace the current C<on_error> callback (see the C<on_error> constructor argument). 356Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232 357
244 369
245sub on_eof { 370sub on_eof {
246 $_[0]{on_eof} = $_[1]; 371 $_[0]{on_eof} = $_[1];
247} 372}
248 373
374=item $handle->on_timeout ($cb)
375
376Replace the current C<on_timeout> callback, or disables the callback (but
377not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
378argument and method.
379
380=cut
381
382sub on_timeout {
383 $_[0]{on_timeout} = $_[1];
384}
385
386=item $handle->autocork ($boolean)
387
388Enables or disables the current autocork behaviour (see C<autocork>
389constructor argument).
390
391=cut
392
393=item $handle->no_delay ($boolean)
394
395Enables or disables the C<no_delay> setting (see constructor argument of
396the same name for details).
397
398=cut
399
400sub no_delay {
401 $_[0]{no_delay} = $_[1];
402
403 eval {
404 local $SIG{__DIE__};
405 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
406 };
407}
408
409#############################################################################
410
411=item $handle->timeout ($seconds)
412
413Configures (or disables) the inactivity timeout.
414
415=cut
416
417sub timeout {
418 my ($self, $timeout) = @_;
419
420 $self->{timeout} = $timeout;
421 $self->_timeout;
422}
423
424# reset the timeout watcher, as neccessary
425# also check for time-outs
426sub _timeout {
427 my ($self) = @_;
428
429 if ($self->{timeout}) {
430 my $NOW = AnyEvent->now;
431
432 # when would the timeout trigger?
433 my $after = $self->{_activity} + $self->{timeout} - $NOW;
434
435 # now or in the past already?
436 if ($after <= 0) {
437 $self->{_activity} = $NOW;
438
439 if ($self->{on_timeout}) {
440 $self->{on_timeout}($self);
441 } else {
442 $self->_error (&Errno::ETIMEDOUT);
443 }
444
445 # callback could have changed timeout value, optimise
446 return unless $self->{timeout};
447
448 # calculate new after
449 $after = $self->{timeout};
450 }
451
452 Scalar::Util::weaken $self;
453 return unless $self; # ->error could have destroyed $self
454
455 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
456 delete $self->{_tw};
457 $self->_timeout;
458 });
459 } else {
460 delete $self->{_tw};
461 }
462}
463
249############################################################################# 464#############################################################################
250 465
251=back 466=back
252 467
253=head2 WRITE QUEUE 468=head2 WRITE QUEUE
274 my ($self, $cb) = @_; 489 my ($self, $cb) = @_;
275 490
276 $self->{on_drain} = $cb; 491 $self->{on_drain} = $cb;
277 492
278 $cb->($self) 493 $cb->($self)
279 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 494 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280} 495}
281 496
282=item $handle->push_write ($data) 497=item $handle->push_write ($data)
283 498
284Queues the given scalar to be written. You can push as much data as you 499Queues the given scalar to be written. You can push as much data as you
288=cut 503=cut
289 504
290sub _drain_wbuf { 505sub _drain_wbuf {
291 my ($self) = @_; 506 my ($self) = @_;
292 507
293 if (!$self->{ww} && length $self->{wbuf}) { 508 if (!$self->{_ww} && length $self->{wbuf}) {
509
294 Scalar::Util::weaken $self; 510 Scalar::Util::weaken $self;
511
295 my $cb = sub { 512 my $cb = sub {
296 my $len = syswrite $self->{fh}, $self->{wbuf}; 513 my $len = syswrite $self->{fh}, $self->{wbuf};
297 514
298 if ($len >= 0) { 515 if ($len >= 0) {
299 substr $self->{wbuf}, 0, $len, ""; 516 substr $self->{wbuf}, 0, $len, "";
300 517
518 $self->{_activity} = AnyEvent->now;
519
301 $self->{on_drain}($self) 520 $self->{on_drain}($self)
302 if $self->{low_water_mark} >= length $self->{wbuf} 521 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303 && $self->{on_drain}; 522 && $self->{on_drain};
304 523
305 delete $self->{ww} unless length $self->{wbuf}; 524 delete $self->{_ww} unless length $self->{wbuf};
306 } elsif ($! != EAGAIN && $! != EINTR) { 525 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307 $self->error; 526 $self->_error ($!, 1);
308 } 527 }
309 }; 528 };
310 529
530 # try to write data immediately
531 $cb->() unless $self->{autocork};
532
533 # if still data left in wbuf, we need to poll
311 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 534 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
312 535 if length $self->{wbuf};
313 $cb->($self);
314 }; 536 };
315} 537}
316 538
317our %WH; 539our %WH;
318 540
328 550
329 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 551 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
330 ->($self, @_); 552 ->($self, @_);
331 } 553 }
332 554
333 if ($self->{filter_w}) { 555 if ($self->{tls}) {
334 $self->{filter_w}->($self, \$_[0]); 556 $self->{_tls_wbuf} .= $_[0];
557 &_dotls ($self);
335 } else { 558 } else {
336 $self->{wbuf} .= $_[0]; 559 $self->{wbuf} .= $_[0];
337 $self->_drain_wbuf; 560 $self->_drain_wbuf;
338 } 561 }
339} 562}
340 563
341=item $handle->push_write (type => @args) 564=item $handle->push_write (type => @args)
342 565
343=item $handle->unshift_write (type => @args)
344
345Instead of formatting your data yourself, you can also let this module do 566Instead of formatting your data yourself, you can also let this module do
346the job by specifying a type and type-specific arguments. 567the job by specifying a type and type-specific arguments.
347 568
348Predefined types are (if you have ideas for additional types, feel free to 569Predefined types are (if you have ideas for additional types, feel free to
349drop by and tell us): 570drop by and tell us):
353=item netstring => $string 574=item netstring => $string
354 575
355Formats the given value as netstring 576Formats the given value as netstring
356(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 577(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357 578
358=back
359
360=cut 579=cut
361 580
362register_write_type netstring => sub { 581register_write_type netstring => sub {
363 my ($self, $string) = @_; 582 my ($self, $string) = @_;
364 583
365 sprintf "%d:%s,", (length $string), $string 584 sprintf "%d:%s,", (length $string), $string
366}; 585};
367 586
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
368=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 660=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
369 661
370This function (not method) lets you add your own types to C<push_write>. 662This function (not method) lets you add your own types to C<push_write>.
371Whenever the given C<type> is used, C<push_write> will invoke the code 663Whenever the given C<type> is used, C<push_write> will invoke the code
372reference with the handle object and the remaining arguments. 664reference with the handle object and the remaining arguments.
373 665
392ways, 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
393a queue. 685a queue.
394 686
395In 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
396new 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
397enough 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
398or not. 690leave the data there if you want to accumulate more (e.g. when only a
691partial message has been received so far).
399 692
400In 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
401case, AnyEvent::Handle will call the first queued callback each time new 694case, AnyEvent::Handle will call the first queued callback each time new
402data 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
403below). 696done its job (see C<push_read>, below).
404 697
405This 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
406a chunk of data, and AnyEvent::Handle will execute them in order. 699a chunk of data, and AnyEvent::Handle will execute them in order.
407 700
408Example 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
409the specified number of bytes which give an XML datagram. 702the specified number of bytes which give an XML datagram.
410 703
411 # in the default state, expect some header bytes 704 # in the default state, expect some header bytes
412 $handle->on_read (sub { 705 $handle->on_read (sub {
413 # 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)
414 shift->unshift_read_chunk (4, sub { 707 shift->unshift_read (chunk => 4, sub {
415 # header arrived, decode 708 # header arrived, decode
416 my $len = unpack "N", $_[1]; 709 my $len = unpack "N", $_[1];
417 710
418 # now read the payload 711 # now read the payload
419 shift->unshift_read_chunk ($len, sub { 712 shift->unshift_read (chunk => $len, sub {
420 my $xml = $_[1]; 713 my $xml = $_[1];
421 # handle xml 714 # handle xml
422 }); 715 });
423 }); 716 });
424 }); 717 });
425 718
426Example 2: Implement a client for a protocol that replies either with 719Example 2: Implement a client for a protocol that replies either with "OK"
427"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
428second 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
429pipeline sending both requests and manipulate the queue as necessary in 722just pipeline sending both requests and manipulate the queue as necessary
430the callbacks: 723in the callbacks.
431 724
432 # 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"
433 $handle->push_write ("request 1\015\012"); 730 $handle->push_write ("request 1\015\012");
434 731
435 # 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
436 $handle->push_read_line (sub { 733 $handle->push_read (line => sub {
437 # if we got an "OK", we have to _prepend_ another line, 734 # if we got an "OK", we have to _prepend_ another line,
438 # so it will be read before the second request reads its 64 bytes 735 # so it will be read before the second request reads its 64 bytes
439 # which are already in the queue when this callback is called 736 # which are already in the queue when this callback is called
440 # we don't do this in case we got an error 737 # we don't do this in case we got an error
441 if ($_[1] eq "OK") { 738 if ($_[1] eq "OK") {
442 $_[0]->unshift_read_line (sub { 739 $_[0]->unshift_read (line => sub {
443 my $response = $_[1]; 740 my $response = $_[1];
444 ... 741 ...
445 }); 742 });
446 } 743 }
447 }); 744 });
448 745
449 # request two 746 # request two, simply returns 64 octets
450 $handle->push_write ("request 2\015\012"); 747 $handle->push_write ("request 2\015\012");
451 748
452 # simply read 64 bytes, always 749 # simply read 64 bytes, always
453 $handle->push_read_chunk (64, sub { 750 $handle->push_read (chunk => 64, sub {
454 my $response = $_[1]; 751 my $response = $_[1];
455 ... 752 ...
456 }); 753 });
457 754
458=over 4 755=over 4
459 756
460=cut 757=cut
461 758
462sub _drain_rbuf { 759sub _drain_rbuf {
463 my ($self) = @_; 760 my ($self) = @_;
761
762 local $self->{_in_drain} = 1;
464 763
465 if ( 764 if (
466 defined $self->{rbuf_max} 765 defined $self->{rbuf_max}
467 && $self->{rbuf_max} < length $self->{rbuf} 766 && $self->{rbuf_max} < length $self->{rbuf}
468 ) { 767 ) {
469 $! = &Errno::ENOSPC; return $self->error; 768 $self->_error (&Errno::ENOSPC, 1), return;
470 } 769 }
471 770
472 return if $self->{in_drain}; 771 while () {
473 local $self->{in_drain} = 1;
474
475 while (my $len = length $self->{rbuf}) { 772 my $len = length $self->{rbuf};
476 no strict 'refs'; 773
477 if (my $cb = shift @{ $self->{queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
478 unless ($cb->($self)) { 775 unless ($cb->($self)) {
479 if ($self->{eof}) { 776 if ($self->{_eof}) {
480 # 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)
481 $! = &Errno::EPIPE; return $self->error; 778 $self->_error (&Errno::EPIPE, 1), return;
482 } 779 }
483 780
484 unshift @{ $self->{queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
485 return; 782 last;
486 } 783 }
487 } elsif ($self->{on_read}) { 784 } elsif ($self->{on_read}) {
785 last unless $len;
786
488 $self->{on_read}($self); 787 $self->{on_read}($self);
489 788
490 if ( 789 if (
491 $self->{eof} # if no further data will arrive
492 && $len == length $self->{rbuf} # and no data has been consumed 790 $len == length $self->{rbuf} # if no data has been consumed
493 && !@{ $self->{queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
494 && $self->{on_read} # and we still want to read data 792 && $self->{on_read} # but we still have on_read
495 ) { 793 ) {
794 # no further data will arrive
496 # then no progress can be made 795 # so no progress can be made
497 $! = &Errno::EPIPE; return $self->error; 796 $self->_error (&Errno::EPIPE, 1), return
797 if $self->{_eof};
798
799 last; # more data might arrive
498 } 800 }
499 } else { 801 } else {
500 # read side becomes idle 802 # read side becomes idle
501 delete $self->{rw}; 803 delete $self->{_rw} unless $self->{tls};
502 return; 804 last;
503 } 805 }
504 } 806 }
505 807
506 if ($self->{eof}) { 808 if ($self->{_eof}) {
507 $self->_shutdown; 809 if ($self->{on_eof}) {
508 $self->{on_eof}($self) 810 $self->{on_eof}($self)
509 if $self->{on_eof}; 811 } else {
812 $self->_error (0, 1);
813 }
814 }
815
816 # may need to restart read watcher
817 unless ($self->{_rw}) {
818 $self->start_read
819 if $self->{on_read} || @{ $self->{_queue} };
510 } 820 }
511} 821}
512 822
513=item $handle->on_read ($cb) 823=item $handle->on_read ($cb)
514 824
520 830
521sub on_read { 831sub on_read {
522 my ($self, $cb) = @_; 832 my ($self, $cb) = @_;
523 833
524 $self->{on_read} = $cb; 834 $self->{on_read} = $cb;
835 $self->_drain_rbuf if $cb && !$self->{_in_drain};
525} 836}
526 837
527=item $handle->rbuf 838=item $handle->rbuf
528 839
529Returns the read buffer (as a modifiable lvalue). 840Returns the read buffer (as a modifiable lvalue).
577 888
578 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 889 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
579 ->($self, $cb, @_); 890 ->($self, $cb, @_);
580 } 891 }
581 892
582 push @{ $self->{queue} }, $cb; 893 push @{ $self->{_queue} }, $cb;
583 $self->_drain_rbuf; 894 $self->_drain_rbuf unless $self->{_in_drain};
584} 895}
585 896
586sub unshift_read { 897sub unshift_read {
587 my $self = shift; 898 my $self = shift;
588 my $cb = pop; 899 my $cb = pop;
593 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 904 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
594 ->($self, $cb, @_); 905 ->($self, $cb, @_);
595 } 906 }
596 907
597 908
598 unshift @{ $self->{queue} }, $cb; 909 unshift @{ $self->{_queue} }, $cb;
599 $self->_drain_rbuf; 910 $self->_drain_rbuf unless $self->{_in_drain};
600} 911}
601 912
602=item $handle->push_read (type => @args, $cb) 913=item $handle->push_read (type => @args, $cb)
603 914
604=item $handle->unshift_read (type => @args, $cb) 915=item $handle->unshift_read (type => @args, $cb)
610Predefined types are (if you have ideas for additional types, feel free to 921Predefined types are (if you have ideas for additional types, feel free to
611drop by and tell us): 922drop by and tell us):
612 923
613=over 4 924=over 4
614 925
615=item chunk => $octets, $cb->($self, $data) 926=item chunk => $octets, $cb->($handle, $data)
616 927
617Invoke the callback only once C<$octets> bytes have been read. Pass the 928Invoke the callback only once C<$octets> bytes have been read. Pass the
618data read to the callback. The callback will never be called with less 929data read to the callback. The callback will never be called with less
619data. 930data.
620 931
634 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 945 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635 1 946 1
636 } 947 }
637}; 948};
638 949
639# compatibility with older API
640sub push_read_chunk {
641 $_[0]->push_read (chunk => $_[1], $_[2]);
642}
643
644sub unshift_read_chunk {
645 $_[0]->unshift_read (chunk => $_[1], $_[2]);
646}
647
648=item line => [$eol, ]$cb->($self, $line, $eol) 950=item line => [$eol, ]$cb->($handle, $line, $eol)
649 951
650The callback will be called only once a full line (including the end of 952The callback will be called only once a full line (including the end of
651line marker, C<$eol>) has been read. This line (excluding the end of line 953line marker, C<$eol>) has been read. This line (excluding the end of line
652marker) will be passed to the callback as second argument (C<$line>), and 954marker) will be passed to the callback as second argument (C<$line>), and
653the end of line marker as the third argument (C<$eol>). 955the end of line marker as the third argument (C<$eol>).
667=cut 969=cut
668 970
669register_read_type line => sub { 971register_read_type line => sub {
670 my ($self, $cb, $eol) = @_; 972 my ($self, $cb, $eol) = @_;
671 973
672 $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 {
673 $eol = quotemeta $eol unless ref $eol; 983 $eol = quotemeta $eol unless ref $eol;
674 $eol = qr|^(.*?)($eol)|s; 984 $eol = qr|^(.*?)($eol)|s;
985
986 sub {
987 $_[0]{rbuf} =~ s/$eol// or return;
988
989 $cb->($_[0], $1, $2);
990 1
991 }
992 }
993};
994
995=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
996
997Makes a regex match against the regex object C<$accept> and returns
998everything up to and including the match.
999
1000Example: read a single line terminated by '\n'.
1001
1002 $handle->push_read (regex => qr<\n>, sub { ... });
1003
1004If C<$reject> is given and not undef, then it determines when the data is
1005to be rejected: it is matched against the data when the C<$accept> regex
1006does not match and generates an C<EBADMSG> error when it matches. This is
1007useful to quickly reject wrong data (to avoid waiting for a timeout or a
1008receive buffer overflow).
1009
1010Example: expect a single decimal number followed by whitespace, reject
1011anything else (not the use of an anchor).
1012
1013 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1014
1015If C<$skip> is given and not C<undef>, then it will be matched against
1016the receive buffer when neither C<$accept> nor C<$reject> match,
1017and everything preceding and including the match will be accepted
1018unconditionally. This is useful to skip large amounts of data that you
1019know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1020have to start matching from the beginning. This is purely an optimisation
1021and is usually worth only when you expect more than a few kilobytes.
1022
1023Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1024expect the header to be very large (it isn't in practise, but...), we use
1025a skip regex to skip initial portions. The skip regex is tricky in that
1026it only accepts something not ending in either \015 or \012, as these are
1027required for the accept regex.
1028
1029 $handle->push_read (regex =>
1030 qr<\015\012\015\012>,
1031 undef, # no reject
1032 qr<^.*[^\015\012]>,
1033 sub { ... });
1034
1035=cut
1036
1037register_read_type regex => sub {
1038 my ($self, $cb, $accept, $reject, $skip) = @_;
1039
1040 my $data;
1041 my $rbuf = \$self->{rbuf};
675 1042
676 sub { 1043 sub {
677 $_[0]{rbuf} =~ s/$eol// or return; 1044 # accept
678 1045 if ($$rbuf =~ $accept) {
679 $cb->($_[0], $1, $2); 1046 $data .= substr $$rbuf, 0, $+[0], "";
1047 $cb->($self, $data);
1048 return 1;
1049 }
680 1 1050
1051 # reject
1052 if ($reject && $$rbuf =~ $reject) {
1053 $self->_error (&Errno::EBADMSG);
1054 }
1055
1056 # skip
1057 if ($skip && $$rbuf =~ $skip) {
1058 $data .= substr $$rbuf, 0, $+[0], "";
1059 }
1060
1061 ()
681 } 1062 }
682}; 1063};
683 1064
684# compatibility with older API
685sub push_read_line {
686 my $self = shift;
687 $self->push_read (line => @_);
688}
689
690sub unshift_read_line {
691 my $self = shift;
692 $self->unshift_read (line => @_);
693}
694
695=item netstring => $cb->($string) 1065=item netstring => $cb->($handle, $string)
696 1066
697A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1067A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698 1068
699Throws an error with C<$!> set to EBADMSG on format violations. 1069Throws an error with C<$!> set to EBADMSG on format violations.
700 1070
704 my ($self, $cb) = @_; 1074 my ($self, $cb) = @_;
705 1075
706 sub { 1076 sub {
707 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1077 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708 if ($_[0]{rbuf} =~ /[^0-9]/) { 1078 if ($_[0]{rbuf} =~ /[^0-9]/) {
709 $! = &Errno::EBADMSG; 1079 $self->_error (&Errno::EBADMSG);
710 $self->error;
711 } 1080 }
712 return; 1081 return;
713 } 1082 }
714 1083
715 my $len = $1; 1084 my $len = $1;
718 my $string = $_[1]; 1087 my $string = $_[1];
719 $_[0]->unshift_read (chunk => 1, sub { 1088 $_[0]->unshift_read (chunk => 1, sub {
720 if ($_[1] eq ",") { 1089 if ($_[1] eq ",") {
721 $cb->($_[0], $string); 1090 $cb->($_[0], $string);
722 } else { 1091 } else {
723 $! = &Errno::EBADMSG; 1092 $self->_error (&Errno::EBADMSG);
724 $self->error;
725 } 1093 }
726 }); 1094 });
727 }); 1095 });
728 1096
729 1 1097 1
730 } 1098 }
731}; 1099};
732 1100
1101=item packstring => $format, $cb->($handle, $string)
1102
1103An octet string prefixed with an encoded length. The encoding C<$format>
1104uses the same format as a Perl C<pack> format, but must specify a single
1105integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1106optional C<!>, C<< < >> or C<< > >> modifier).
1107
1108DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
1109
1110Example: read a block of data prefixed by its length in BER-encoded
1111format (very efficient).
1112
1113 $handle->push_read (packstring => "w", sub {
1114 my ($handle, $data) = @_;
1115 });
1116
1117=cut
1118
1119register_read_type packstring => sub {
1120 my ($self, $cb, $format) = @_;
1121
1122 sub {
1123 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1124 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1125 or return;
1126
1127 $format = length pack $format, $len;
1128
1129 # bypass unshift if we already have the remaining chunk
1130 if ($format + $len <= length $_[0]{rbuf}) {
1131 my $data = substr $_[0]{rbuf}, $format, $len;
1132 substr $_[0]{rbuf}, 0, $format + $len, "";
1133 $cb->($_[0], $data);
1134 } else {
1135 # remove prefix
1136 substr $_[0]{rbuf}, 0, $format, "";
1137
1138 # read remaining chunk
1139 $_[0]->unshift_read (chunk => $len, $cb);
1140 }
1141
1142 1
1143 }
1144};
1145
1146=item json => $cb->($handle, $hash_or_arrayref)
1147
1148Reads a JSON object or array, decodes it and passes it to the callback.
1149
1150If a C<json> object was passed to the constructor, then that will be used
1151for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1152
1153This read type uses the incremental parser available with JSON version
11542.09 (and JSON::XS version 2.2) and above. You have to provide a
1155dependency on your own: this module will load the JSON module, but
1156AnyEvent does not depend on it itself.
1157
1158Since JSON texts are fully self-delimiting, the C<json> read and write
1159types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1160the C<json> write type description, above, for an actual example.
1161
1162=cut
1163
1164register_read_type json => sub {
1165 my ($self, $cb) = @_;
1166
1167 require JSON;
1168
1169 my $data;
1170 my $rbuf = \$self->{rbuf};
1171
1172 my $json = $self->{json} ||= JSON->new->utf8;
1173
1174 sub {
1175 my $ref = $json->incr_parse ($self->{rbuf});
1176
1177 if ($ref) {
1178 $self->{rbuf} = $json->incr_text;
1179 $json->incr_text = "";
1180 $cb->($self, $ref);
1181
1182 1
1183 } else {
1184 $self->{rbuf} = "";
1185 ()
1186 }
1187 }
1188};
1189
1190=item storable => $cb->($handle, $ref)
1191
1192Deserialises a L<Storable> frozen representation as written by the
1193C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1194data).
1195
1196Raises C<EBADMSG> error if the data could not be decoded.
1197
1198=cut
1199
1200register_read_type storable => sub {
1201 my ($self, $cb) = @_;
1202
1203 require Storable;
1204
1205 sub {
1206 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1207 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1208 or return;
1209
1210 my $format = length pack "w", $len;
1211
1212 # bypass unshift if we already have the remaining chunk
1213 if ($format + $len <= length $_[0]{rbuf}) {
1214 my $data = substr $_[0]{rbuf}, $format, $len;
1215 substr $_[0]{rbuf}, 0, $format + $len, "";
1216 $cb->($_[0], Storable::thaw ($data));
1217 } else {
1218 # remove prefix
1219 substr $_[0]{rbuf}, 0, $format, "";
1220
1221 # read remaining chunk
1222 $_[0]->unshift_read (chunk => $len, sub {
1223 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1224 $cb->($_[0], $ref);
1225 } else {
1226 $self->_error (&Errno::EBADMSG);
1227 }
1228 });
1229 }
1230
1231 1
1232 }
1233};
1234
733=back 1235=back
734 1236
735=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1237=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
736 1238
737This function (not method) lets you add your own types to C<push_read>. 1239This function (not method) lets you add your own types to C<push_read>.
738 1240
739Whenever the given C<type> is used, C<push_read> will invoke the code 1241Whenever the given C<type> is used, C<push_read> will invoke the code
740reference with the handle object, the callback and the remaining 1242reference with the handle object, the callback and the remaining
742 1244
743The code reference is supposed to return a callback (usually a closure) 1245The code reference is supposed to return a callback (usually a closure)
744that works as a plain read callback (see C<< ->push_read ($cb) >>). 1246that works as a plain read callback (see C<< ->push_read ($cb) >>).
745 1247
746It should invoke the passed callback when it is done reading (remember to 1248It should invoke the passed callback when it is done reading (remember to
747pass C<$self> as first argument as all other callbacks do that). 1249pass C<$handle> as first argument as all other callbacks do that).
748 1250
749Note that this is a function, and all types registered this way will be 1251Note that this is a function, and all types registered this way will be
750global, so try to use unique names. 1252global, so try to use unique names.
751 1253
752For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1254For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
755=item $handle->stop_read 1257=item $handle->stop_read
756 1258
757=item $handle->start_read 1259=item $handle->start_read
758 1260
759In rare cases you actually do not want to read anything from the 1261In rare cases you actually do not want to read anything from the
760socket. In this case you can call C<stop_read>. Neither C<on_read> no 1262socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761any queued callbacks will be executed then. To start reading again, call 1263any queued callbacks will be executed then. To start reading again, call
762C<start_read>. 1264C<start_read>.
763 1265
1266Note that AnyEvent::Handle will automatically C<start_read> for you when
1267you change the C<on_read> callback or push/unshift a read callback, and it
1268will automatically C<stop_read> for you when neither C<on_read> is set nor
1269there are any read requests in the queue.
1270
1271These methods will have no effect when in TLS mode (as TLS doesn't support
1272half-duplex connections).
1273
764=cut 1274=cut
765 1275
766sub stop_read { 1276sub stop_read {
767 my ($self) = @_; 1277 my ($self) = @_;
768 1278
769 delete $self->{rw}; 1279 delete $self->{_rw} unless $self->{tls};
770} 1280}
771 1281
772sub start_read { 1282sub start_read {
773 my ($self) = @_; 1283 my ($self) = @_;
774 1284
775 unless ($self->{rw} || $self->{eof}) { 1285 unless ($self->{_rw} || $self->{_eof}) {
776 Scalar::Util::weaken $self; 1286 Scalar::Util::weaken $self;
777 1287
778 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1288 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
779 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1289 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1290 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781 1291
782 if ($len > 0) { 1292 if ($len > 0) {
783 $self->{filter_r} 1293 $self->{_activity} = AnyEvent->now;
784 ? $self->{filter_r}->($self, $rbuf) 1294
785 : $self->_drain_rbuf; 1295 if ($self->{tls}) {
1296 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1297 &_dotls ($self);
1298 } else {
1299 $self->_drain_rbuf unless $self->{_in_drain};
1300 }
786 1301
787 } elsif (defined $len) { 1302 } elsif (defined $len) {
788 delete $self->{rw}; 1303 delete $self->{_rw};
789 $self->{eof} = 1; 1304 $self->{_eof} = 1;
790 $self->_drain_rbuf; 1305 $self->_drain_rbuf unless $self->{_in_drain};
791 1306
792 } elsif ($! != EAGAIN && $! != EINTR) { 1307 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793 return $self->error; 1308 return $self->_error ($!, 1);
794 } 1309 }
795 }); 1310 });
796 } 1311 }
797} 1312}
798 1313
799sub _dotls { 1314sub _dotls {
800 my ($self) = @_; 1315 my ($self) = @_;
801 1316
1317 my $buf;
1318
802 if (length $self->{tls_wbuf}) { 1319 if (length $self->{_tls_wbuf}) {
803 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1320 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804 substr $self->{tls_wbuf}, 0, $len, ""; 1321 substr $self->{_tls_wbuf}, 0, $len, "";
805 } 1322 }
806 } 1323 }
807 1324
1325 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
1326 unless (length $buf) {
1327 # let's treat SSL-eof as we treat normal EOF
1328 delete $self->{_rw};
1329 $self->{_eof} = 1;
1330 &_freetls;
1331 }
1332
1333 $self->{rbuf} .= $buf;
1334 $self->_drain_rbuf unless $self->{_in_drain};
1335 $self->{tls} or return; # tls session might have gone away in callback
1336 }
1337
1338 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1339
1340 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1341 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1342 return $self->_error ($!, 1);
1343 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1344 return $self->_error (&Errno::EIO, 1);
1345 }
1346
1347 # all others are fine for our purposes
1348 }
1349
808 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1350 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809 $self->{wbuf} .= $buf; 1351 $self->{wbuf} .= $buf;
810 $self->_drain_wbuf; 1352 $self->_drain_wbuf;
811 }
812
813 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
814 $self->{rbuf} .= $buf;
815 $self->_drain_rbuf;
816 }
817
818 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
819
820 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
821 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
822 $self->error;
823 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
824 $! = &Errno::EIO;
825 $self->error;
826 }
827
828 # all others are fine for our purposes
829 } 1353 }
830} 1354}
831 1355
832=item $handle->starttls ($tls[, $tls_ctx]) 1356=item $handle->starttls ($tls[, $tls_ctx])
833 1357
839C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1363C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840 1364
841The second argument is the optional C<Net::SSLeay::CTX> object that is 1365The second argument is the optional C<Net::SSLeay::CTX> object that is
842used when AnyEvent::Handle has to create its own TLS connection object. 1366used when AnyEvent::Handle has to create its own TLS connection object.
843 1367
844=cut 1368The TLS connection object will end up in C<< $handle->{tls} >> after this
1369call and can be used or changed to your liking. Note that the handshake
1370might have already started when this function returns.
845 1371
846# TODO: maybe document... 1372If it an error to start a TLS handshake more than once per
1373AnyEvent::Handle object (this is due to bugs in OpenSSL).
1374
1375=cut
1376
847sub starttls { 1377sub starttls {
848 my ($self, $ssl, $ctx) = @_; 1378 my ($self, $ssl, $ctx) = @_;
849 1379
850 $self->stoptls; 1380 Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"
851 1381 if $self->{tls};
1382
852 if ($ssl eq "accept") { 1383 if ($ssl eq "accept") {
853 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1384 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
854 Net::SSLeay::set_accept_state ($ssl); 1385 Net::SSLeay::set_accept_state ($ssl);
855 } elsif ($ssl eq "connect") { 1386 } elsif ($ssl eq "connect") {
856 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1387 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
862 # basically, this is deep magic (because SSL_read should have the same issues) 1393 # basically, this is deep magic (because SSL_read should have the same issues)
863 # but the openssl maintainers basically said: "trust us, it just works". 1394 # but the openssl maintainers basically said: "trust us, it just works".
864 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1395 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
865 # and mismaintained ssleay-module doesn't even offer them). 1396 # and mismaintained ssleay-module doesn't even offer them).
866 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1397 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1398 #
1399 # in short: this is a mess.
1400 #
1401 # note that we do not try to keep the length constant between writes as we are required to do.
1402 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1403 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1404 # have identity issues in that area.
867 Net::SSLeay::CTX_set_mode ($self->{tls}, 1405 Net::SSLeay::CTX_set_mode ($self->{tls},
868 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1406 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1407 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
870 1408
871 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1409 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1410 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873 1411
874 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1412 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
875 1413
876 $self->{filter_w} = sub { 1414 &_dotls; # need to trigger the initial handshake
877 $_[0]{tls_wbuf} .= ${$_[1]}; 1415 $self->start_read; # make sure we actually do read
878 &_dotls;
879 };
880 $self->{filter_r} = sub {
881 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882 &_dotls;
883 };
884} 1416}
885 1417
886=item $handle->stoptls 1418=item $handle->stoptls
887 1419
888Destroys the SSL connection, if any. Partial read or write data will be 1420Shuts down the SSL connection - this makes a proper EOF handshake by
889lost. 1421sending a close notify to the other side, but since OpenSSL doesn't
1422support non-blocking shut downs, it is not possible to re-use the stream
1423afterwards.
890 1424
891=cut 1425=cut
892 1426
893sub stoptls { 1427sub stoptls {
894 my ($self) = @_; 1428 my ($self) = @_;
895 1429
1430 if ($self->{tls}) {
1431 Net::SSLeay::shutdown $self->{tls};
1432
1433 &_dotls;
1434
1435 # we don't give a shit. no, we do, but we can't. no...
1436 # we, we... have to use openssl :/
1437 &_freetls;
1438 }
1439}
1440
1441sub _freetls {
1442 my ($self) = @_;
1443
1444 return unless $self->{tls};
1445
896 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1446 Net::SSLeay::free (delete $self->{tls});
897 delete $self->{tls_rbio}; 1447
898 delete $self->{tls_wbio}; 1448 delete @$self{qw(_rbio _wbio _tls_wbuf)};
899 delete $self->{tls_wbuf};
900 delete $self->{filter_r};
901 delete $self->{filter_w};
902} 1449}
903 1450
904sub DESTROY { 1451sub DESTROY {
905 my $self = shift; 1452 my $self = shift;
906 1453
907 $self->stoptls; 1454 &_freetls;
1455
1456 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1457
1458 if ($linger && length $self->{wbuf}) {
1459 my $fh = delete $self->{fh};
1460 my $wbuf = delete $self->{wbuf};
1461
1462 my @linger;
1463
1464 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1465 my $len = syswrite $fh, $wbuf, length $wbuf;
1466
1467 if ($len > 0) {
1468 substr $wbuf, 0, $len, "";
1469 } else {
1470 @linger = (); # end
1471 }
1472 });
1473 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1474 @linger = ();
1475 });
1476 }
908} 1477}
909 1478
910=item AnyEvent::Handle::TLS_CTX 1479=item AnyEvent::Handle::TLS_CTX
911 1480
912This function creates and returns the Net::SSLeay::CTX object used by 1481This function creates and returns the Net::SSLeay::CTX object used by
942 } 1511 }
943} 1512}
944 1513
945=back 1514=back
946 1515
1516=head1 SUBCLASSING AnyEvent::Handle
1517
1518In many cases, you might want to subclass AnyEvent::Handle.
1519
1520To make this easier, a given version of AnyEvent::Handle uses these
1521conventions:
1522
1523=over 4
1524
1525=item * all constructor arguments become object members.
1526
1527At least initially, when you pass a C<tls>-argument to the constructor it
1528will end up in C<< $handle->{tls} >>. Those members might be changed or
1529mutated later on (for example C<tls> will hold the TLS connection object).
1530
1531=item * other object member names are prefixed with an C<_>.
1532
1533All object members not explicitly documented (internal use) are prefixed
1534with an underscore character, so the remaining non-C<_>-namespace is free
1535for use for subclasses.
1536
1537=item * all members not documented here and not prefixed with an underscore
1538are free to use in subclasses.
1539
1540Of course, new versions of AnyEvent::Handle may introduce more "public"
1541member variables, but thats just life, at least it is documented.
1542
1543=back
1544
947=head1 AUTHOR 1545=head1 AUTHOR
948 1546
949Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1547Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950 1548
951=cut 1549=cut

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