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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.33 by root, Sun May 25 03:03:51 2008 UTC vs.
Revision 1.129 by root, Mon Jun 29 11:04:09 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util qw(WSAWOULDBLOCK); 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 = 4.42;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($self) 82=item on_eof => $cb->($handle)
79 83
80Set 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.
81 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
82While not mandatory, it is highly recommended to set an eof callback, 93While 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 94otherwise you might end up with a closed socket while you are still
84waiting for data. 95waiting for data.
85 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
86=item on_error => $cb->($self) 100=item on_error => $cb->($handle, $fatal)
87 101
88This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
90or a read error. 104connect or a read error.
91 105
92The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$fatal> being true). On
93called. 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>).
94 116
95On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
97 119
98While 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
99you will not be notified of errors otherwise. The default simply calls 121you will not be notified of errors otherwise. The default simply calls
100die. 122C<croak>.
101 123
102=item on_read => $cb->($self) 124=item on_read => $cb->($handle)
103 125
104This sets the default read callback, which is called when data arrives 126This sets the default read callback, which is called when data arrives
105and 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).
106 130
107To 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 >>
108method or access the C<$self->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly. Note that you
133must not enlarge or modify the read buffer, you can only remove data at
134the beginning from it.
109 135
110When an EOF condition is detected then AnyEvent::Handle will first try to 136When 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 137feed 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 138calling the C<on_eof> callback. If no progress can be made, then a fatal
113error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
114 140
115=item on_drain => $cb->() 141=item on_drain => $cb->($handle)
116 142
117This sets the callback that is called when the write buffer becomes empty 143This 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). 144(or when the callback is set and the buffer is empty already).
119 145
120To append to the write buffer, use the C<< ->push_write >> method. 146To append to the write buffer, use the C<< ->push_write >> method.
121 147
148This callback is useful when you don't want to put all of your write data
149into the queue at once, for example, when you want to write the contents
150of some file to the socket you might not want to read the whole file into
151memory and push it into the queue, but instead only read more data from
152the file when the write queue becomes empty.
153
154=item timeout => $fractional_seconds
155
156If non-zero, then this enables an "inactivity" timeout: whenever this many
157seconds pass without a successful read or write on the underlying file
158handle, the C<on_timeout> callback will be invoked (and if that one is
159missing, a non-fatal C<ETIMEDOUT> error will be raised).
160
161Note that timeout processing is also active when you currently do not have
162any outstanding read or write requests: If you plan to keep the connection
163idle then you should disable the timout temporarily or ignore the timeout
164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
166
167Zero (the default) disables this timeout.
168
169=item on_timeout => $cb->($handle)
170
171Called whenever the inactivity timeout passes. If you return from this
172callback, then the timeout will be reset as if some activity had happened,
173so this condition is not fatal in any way.
174
122=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
123 176
124If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 177If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125when the read buffer ever (strictly) exceeds this size. This is useful to 178when the read buffer ever (strictly) exceeds this size. This is useful to
126avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
127 180
128For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
129be configured to accept only so-and-so much data that it cannot act on 182be 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 183(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 184amount of data without a callback ever being called as long as the line
132isn't finished). 185isn't finished).
133 186
187=item autocork => <boolean>
188
189When disabled (the default), then C<push_write> will try to immediately
190write the data to the handle, if possible. This avoids having to register
191a write watcher and wait for the next event loop iteration, but can
192be inefficient if you write multiple small chunks (on the wire, this
193disadvantage is usually avoided by your kernel's nagle algorithm, see
194C<no_delay>, but this option can save costly syscalls).
195
196When enabled, then writes will always be queued till the next event loop
197iteration. This is efficient when you do many small writes per iteration,
198but less efficient when you do a single write only per iteration (or when
199the write buffer often is full). It also increases write latency.
200
201=item no_delay => <boolean>
202
203When doing small writes on sockets, your operating system kernel might
204wait a bit for more data before actually sending it out. This is called
205the Nagle algorithm, and usually it is beneficial.
206
207In some situations you want as low a delay as possible, which can be
208accomplishd by setting this option to a true value.
209
210The default is your opertaing system's default behaviour (most likely
211enabled), this option explicitly enables or disables it, if possible.
212
134=item read_size => <bytes> 213=item read_size => <bytes>
135 214
136The default read block size (the amount of bytes this module will try to read 215The default read block size (the amount of bytes this module will
137on each [loop iteration). Default: C<4096>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
138 218
139=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
140 220
141Sets the amount of bytes (default: C<0>) that make up an "empty" write 221Sets 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 222buffer: If the write reaches this size or gets even samller it is
143considered empty. 223considered empty.
144 224
225Sometimes it can be beneficial (for performance reasons) to add data to
226the write buffer before it is fully drained, but this is a rare case, as
227the operating system kernel usually buffers data as well, so the default
228is good in almost all cases.
229
230=item linger => <seconds>
231
232If non-zero (default: C<3600>), then the destructor of the
233AnyEvent::Handle object will check whether there is still outstanding
234write data and will install a watcher that will write this data to the
235socket. No errors will be reported (this mostly matches how the operating
236system treats outstanding data at socket close time).
237
238This will not work for partial TLS data that could not be encoded
239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
241
145=item tls => "accept" | "connect" | Net::SSLeay::SSL object 242=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146 243
147When this parameter is given, it enables TLS (SSL) mode, that means it 244When this parameter is given, it enables TLS (SSL) mode, that means
148will start making tls handshake and will transparently encrypt/decrypt 245AnyEvent will start a TLS handshake as soon as the conenction has been
149data. 246established and will transparently encrypt/decrypt data afterwards.
150 247
151TLS mode requires Net::SSLeay to be installed (it will be loaded 248TLS mode requires Net::SSLeay to be installed (it will be loaded
152automatically when you try to create a TLS handle). 249automatically when you try to create a TLS handle): this module doesn't
250have a dependency on that module, so if your module requires it, you have
251to add the dependency yourself.
153 252
154For the TLS server side, use C<accept>, and for the TLS client side of a 253Unlike TCP, TLS has a server and client side: for the TLS server side, use
155connection, use C<connect> mode. 254C<accept>, and for the TLS client side of a connection, use C<connect>
255mode.
156 256
157You can also provide your own TLS connection object, but you have 257You can also provide your own TLS connection object, but you have
158to make sure that you call either C<Net::SSLeay::set_connect_state> 258to 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 259or C<Net::SSLeay::set_accept_state> on it before you pass it to
160AnyEvent::Handle. 260AnyEvent::Handle.
161 261
262B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
263passing in the wrong integer will lead to certain crash. This most often
264happens when one uses a stylish C<< tls => 1 >> and is surprised about the
265segmentation fault.
266
162See the C<starttls> method if you need to start TLs negotiation later. 267See the C<< ->starttls >> method for when need to start TLS negotiation later.
163 268
164=item tls_ctx => $ssl_ctx 269=item tls_ctx => $ssl_ctx
165 270
166Use the given Net::SSLeay::CTX object to create the new TLS connection 271Use 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 272(unless a connection object was specified directly). If this parameter is
168missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 273missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169 274
275=item json => JSON or JSON::XS object
276
277This is the json coder object used by the C<json> read and write types.
278
279If you don't supply it, then AnyEvent::Handle will create and use a
280suitable one (on demand), which will write and expect UTF-8 encoded JSON
281texts.
282
283Note that you are responsible to depend on the JSON module if you want to
284use this functionality, as AnyEvent does not have a dependency itself.
285
170=back 286=back
171 287
172=cut 288=cut
173 289
174sub new { 290sub new {
178 294
179 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
180 296
181 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182 298
183 if ($self->{tls}) {
184 require Net::SSLeay;
185 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186 } 300 if $self->{tls};
187 301
188 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 302 $self->{_activity} = AnyEvent->now;
189 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 303 $self->_timeout;
304
190 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
191 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 306 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
192 307
193 $self->start_read; 308 $self->start_read
309 if $self->{on_read};
194 310
195 $self 311 $self
196} 312}
197 313
198sub _shutdown { 314sub _shutdown {
199 my ($self) = @_; 315 my ($self) = @_;
200 316
201 delete $self->{rw}; 317 delete @$self{qw(_tw _rw _ww fh rbuf wbuf on_read _queue)};
202 delete $self->{ww};
203 delete $self->{fh};
204}
205 318
319 &_freetls;
320}
321
206sub error { 322sub _error {
207 my ($self) = @_; 323 my ($self, $errno, $fatal) = @_;
208 324
209 {
210 local $!;
211 $self->_shutdown; 325 $self->_shutdown
212 } 326 if $fatal;
327
328 $! = $errno;
213 329
214 if ($self->{on_error}) { 330 if ($self->{on_error}) {
215 $self->{on_error}($self); 331 $self->{on_error}($self, $fatal);
216 } else { 332 } elsif ($self->{fh}) {
217 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 333 Carp::croak "AnyEvent::Handle uncaught error: $!";
218 } 334 }
219} 335}
220 336
221=item $fh = $handle->fh 337=item $fh = $handle->fh
222 338
223This method returns the file handle of the L<AnyEvent::Handle> object. 339This method returns the file handle used to create the L<AnyEvent::Handle> object.
224 340
225=cut 341=cut
226 342
227sub fh { $_[0]->{fh} } 343sub fh { $_[0]{fh} }
228 344
229=item $handle->on_error ($cb) 345=item $handle->on_error ($cb)
230 346
231Replace the current C<on_error> callback (see the C<on_error> constructor argument). 347Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232 348
244 360
245sub on_eof { 361sub on_eof {
246 $_[0]{on_eof} = $_[1]; 362 $_[0]{on_eof} = $_[1];
247} 363}
248 364
365=item $handle->on_timeout ($cb)
366
367Replace the current C<on_timeout> callback, or disables the callback (but
368not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
369argument and method.
370
371=cut
372
373sub on_timeout {
374 $_[0]{on_timeout} = $_[1];
375}
376
377=item $handle->autocork ($boolean)
378
379Enables or disables the current autocork behaviour (see C<autocork>
380constructor argument). Changes will only take effect on the next write.
381
382=cut
383
384sub autocork {
385 $_[0]{autocork} = $_[1];
386}
387
388=item $handle->no_delay ($boolean)
389
390Enables or disables the C<no_delay> setting (see constructor argument of
391the same name for details).
392
393=cut
394
395sub no_delay {
396 $_[0]{no_delay} = $_[1];
397
398 eval {
399 local $SIG{__DIE__};
400 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
401 };
402}
403
404#############################################################################
405
406=item $handle->timeout ($seconds)
407
408Configures (or disables) the inactivity timeout.
409
410=cut
411
412sub timeout {
413 my ($self, $timeout) = @_;
414
415 $self->{timeout} = $timeout;
416 $self->_timeout;
417}
418
419# reset the timeout watcher, as neccessary
420# also check for time-outs
421sub _timeout {
422 my ($self) = @_;
423
424 if ($self->{timeout}) {
425 my $NOW = AnyEvent->now;
426
427 # when would the timeout trigger?
428 my $after = $self->{_activity} + $self->{timeout} - $NOW;
429
430 # now or in the past already?
431 if ($after <= 0) {
432 $self->{_activity} = $NOW;
433
434 if ($self->{on_timeout}) {
435 $self->{on_timeout}($self);
436 } else {
437 $self->_error (&Errno::ETIMEDOUT);
438 }
439
440 # callback could have changed timeout value, optimise
441 return unless $self->{timeout};
442
443 # calculate new after
444 $after = $self->{timeout};
445 }
446
447 Scalar::Util::weaken $self;
448 return unless $self; # ->error could have destroyed $self
449
450 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
451 delete $self->{_tw};
452 $self->_timeout;
453 });
454 } else {
455 delete $self->{_tw};
456 }
457}
458
249############################################################################# 459#############################################################################
250 460
251=back 461=back
252 462
253=head2 WRITE QUEUE 463=head2 WRITE QUEUE
274 my ($self, $cb) = @_; 484 my ($self, $cb) = @_;
275 485
276 $self->{on_drain} = $cb; 486 $self->{on_drain} = $cb;
277 487
278 $cb->($self) 488 $cb->($self)
279 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 489 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280} 490}
281 491
282=item $handle->push_write ($data) 492=item $handle->push_write ($data)
283 493
284Queues the given scalar to be written. You can push as much data as you 494Queues the given scalar to be written. You can push as much data as you
288=cut 498=cut
289 499
290sub _drain_wbuf { 500sub _drain_wbuf {
291 my ($self) = @_; 501 my ($self) = @_;
292 502
293 if (!$self->{ww} && length $self->{wbuf}) { 503 if (!$self->{_ww} && length $self->{wbuf}) {
504
294 Scalar::Util::weaken $self; 505 Scalar::Util::weaken $self;
506
295 my $cb = sub { 507 my $cb = sub {
296 my $len = syswrite $self->{fh}, $self->{wbuf}; 508 my $len = syswrite $self->{fh}, $self->{wbuf};
297 509
298 if ($len >= 0) { 510 if ($len >= 0) {
299 substr $self->{wbuf}, 0, $len, ""; 511 substr $self->{wbuf}, 0, $len, "";
300 512
513 $self->{_activity} = AnyEvent->now;
514
301 $self->{on_drain}($self) 515 $self->{on_drain}($self)
302 if $self->{low_water_mark} >= length $self->{wbuf} 516 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303 && $self->{on_drain}; 517 && $self->{on_drain};
304 518
305 delete $self->{ww} unless length $self->{wbuf}; 519 delete $self->{_ww} unless length $self->{wbuf};
306 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAWOULDBLOCK) { 520 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307 $self->error; 521 $self->_error ($!, 1);
308 } 522 }
309 }; 523 };
310 524
525 # try to write data immediately
526 $cb->() unless $self->{autocork};
527
528 # if still data left in wbuf, we need to poll
311 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 529 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
312 530 if length $self->{wbuf};
313 $cb->($self);
314 }; 531 };
315} 532}
316 533
317our %WH; 534our %WH;
318 535
328 545
329 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 546 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
330 ->($self, @_); 547 ->($self, @_);
331 } 548 }
332 549
333 if ($self->{filter_w}) { 550 if ($self->{tls}) {
334 $self->{filter_w}->($self, \$_[0]); 551 $self->{_tls_wbuf} .= $_[0];
552
553 &_dotls ($self);
335 } else { 554 } else {
336 $self->{wbuf} .= $_[0]; 555 $self->{wbuf} .= $_[0];
337 $self->_drain_wbuf; 556 $self->_drain_wbuf;
338 } 557 }
339} 558}
340 559
341=item $handle->push_write (type => @args) 560=item $handle->push_write (type => @args)
342 561
343=item $handle->unshift_write (type => @args)
344
345Instead of formatting your data yourself, you can also let this module do 562Instead of formatting your data yourself, you can also let this module do
346the job by specifying a type and type-specific arguments. 563the job by specifying a type and type-specific arguments.
347 564
348Predefined types are (if you have ideas for additional types, feel free to 565Predefined types are (if you have ideas for additional types, feel free to
349drop by and tell us): 566drop by and tell us):
353=item netstring => $string 570=item netstring => $string
354 571
355Formats the given value as netstring 572Formats the given value as netstring
356(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 573(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357 574
358=back
359
360=cut 575=cut
361 576
362register_write_type netstring => sub { 577register_write_type netstring => sub {
363 my ($self, $string) = @_; 578 my ($self, $string) = @_;
364 579
365 sprintf "%d:%s,", (length $string), $string 580 (length $string) . ":$string,"
366}; 581};
367 582
583=item packstring => $format, $data
584
585An octet string prefixed with an encoded length. The encoding C<$format>
586uses the same format as a Perl C<pack> format, but must specify a single
587integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
588optional C<!>, C<< < >> or C<< > >> modifier).
589
590=cut
591
592register_write_type packstring => sub {
593 my ($self, $format, $string) = @_;
594
595 pack "$format/a*", $string
596};
597
598=item json => $array_or_hashref
599
600Encodes the given hash or array reference into a JSON object. Unless you
601provide your own JSON object, this means it will be encoded to JSON text
602in UTF-8.
603
604JSON objects (and arrays) are self-delimiting, so you can write JSON at
605one end of a handle and read them at the other end without using any
606additional framing.
607
608The generated JSON text is guaranteed not to contain any newlines: While
609this module doesn't need delimiters after or between JSON texts to be
610able to read them, many other languages depend on that.
611
612A simple RPC protocol that interoperates easily with others is to send
613JSON arrays (or objects, although arrays are usually the better choice as
614they mimic how function argument passing works) and a newline after each
615JSON text:
616
617 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
618 $handle->push_write ("\012");
619
620An AnyEvent::Handle receiver would simply use the C<json> read type and
621rely on the fact that the newline will be skipped as leading whitespace:
622
623 $handle->push_read (json => sub { my $array = $_[1]; ... });
624
625Other languages could read single lines terminated by a newline and pass
626this line into their JSON decoder of choice.
627
628=cut
629
630register_write_type json => sub {
631 my ($self, $ref) = @_;
632
633 require JSON;
634
635 $self->{json} ? $self->{json}->encode ($ref)
636 : JSON::encode_json ($ref)
637};
638
639=item storable => $reference
640
641Freezes the given reference using L<Storable> and writes it to the
642handle. Uses the C<nfreeze> format.
643
644=cut
645
646register_write_type storable => sub {
647 my ($self, $ref) = @_;
648
649 require Storable;
650
651 pack "w/a*", Storable::nfreeze ($ref)
652};
653
654=back
655
368=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 656=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
369 657
370This function (not method) lets you add your own types to C<push_write>. 658This 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 659Whenever the given C<type> is used, C<push_write> will invoke the code
372reference with the handle object and the remaining arguments. 660reference with the handle object and the remaining arguments.
373 661
392ways, the "simple" way, using only C<on_read> and the "complex" way, using 680ways, the "simple" way, using only C<on_read> and the "complex" way, using
393a queue. 681a queue.
394 682
395In the simple case, you just install an C<on_read> callback and whenever 683In 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 684new 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 685enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
398or not. 686leave the data there if you want to accumulate more (e.g. when only a
687partial message has been received so far).
399 688
400In the more complex case, you want to queue multiple callbacks. In this 689In the more complex case, you want to queue multiple callbacks. In this
401case, AnyEvent::Handle will call the first queued callback each time new 690case, 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>, 691data arrives (also the first time it is queued) and removes it when it has
403below). 692done its job (see C<push_read>, below).
404 693
405This way you can, for example, push three line-reads, followed by reading 694This way you can, for example, push three line-reads, followed by reading
406a chunk of data, and AnyEvent::Handle will execute them in order. 695a chunk of data, and AnyEvent::Handle will execute them in order.
407 696
408Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 697Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409the specified number of bytes which give an XML datagram. 698the specified number of bytes which give an XML datagram.
410 699
411 # in the default state, expect some header bytes 700 # in the default state, expect some header bytes
412 $handle->on_read (sub { 701 $handle->on_read (sub {
413 # some data is here, now queue the length-header-read (4 octets) 702 # some data is here, now queue the length-header-read (4 octets)
414 shift->unshift_read_chunk (4, sub { 703 shift->unshift_read (chunk => 4, sub {
415 # header arrived, decode 704 # header arrived, decode
416 my $len = unpack "N", $_[1]; 705 my $len = unpack "N", $_[1];
417 706
418 # now read the payload 707 # now read the payload
419 shift->unshift_read_chunk ($len, sub { 708 shift->unshift_read (chunk => $len, sub {
420 my $xml = $_[1]; 709 my $xml = $_[1];
421 # handle xml 710 # handle xml
422 }); 711 });
423 }); 712 });
424 }); 713 });
425 714
426Example 2: Implement a client for a protocol that replies either with 715Example 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 716and 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 717bytes for the second request. Due to the availability of a queue, we can
429pipeline sending both requests and manipulate the queue as necessary in 718just pipeline sending both requests and manipulate the queue as necessary
430the callbacks: 719in the callbacks.
431 720
432 # request one 721When the first callback is called and sees an "OK" response, it will
722C<unshift> another line-read. This line-read will be queued I<before> the
72364-byte chunk callback.
724
725 # request one, returns either "OK + extra line" or "ERROR"
433 $handle->push_write ("request 1\015\012"); 726 $handle->push_write ("request 1\015\012");
434 727
435 # we expect "ERROR" or "OK" as response, so push a line read 728 # we expect "ERROR" or "OK" as response, so push a line read
436 $handle->push_read_line (sub { 729 $handle->push_read (line => sub {
437 # if we got an "OK", we have to _prepend_ another line, 730 # if we got an "OK", we have to _prepend_ another line,
438 # so it will be read before the second request reads its 64 bytes 731 # so it will be read before the second request reads its 64 bytes
439 # which are already in the queue when this callback is called 732 # which are already in the queue when this callback is called
440 # we don't do this in case we got an error 733 # we don't do this in case we got an error
441 if ($_[1] eq "OK") { 734 if ($_[1] eq "OK") {
442 $_[0]->unshift_read_line (sub { 735 $_[0]->unshift_read (line => sub {
443 my $response = $_[1]; 736 my $response = $_[1];
444 ... 737 ...
445 }); 738 });
446 } 739 }
447 }); 740 });
448 741
449 # request two 742 # request two, simply returns 64 octets
450 $handle->push_write ("request 2\015\012"); 743 $handle->push_write ("request 2\015\012");
451 744
452 # simply read 64 bytes, always 745 # simply read 64 bytes, always
453 $handle->push_read_chunk (64, sub { 746 $handle->push_read (chunk => 64, sub {
454 my $response = $_[1]; 747 my $response = $_[1];
455 ... 748 ...
456 }); 749 });
457 750
458=over 4 751=over 4
459 752
460=cut 753=cut
461 754
462sub _drain_rbuf { 755sub _drain_rbuf {
463 my ($self) = @_; 756 my ($self) = @_;
757
758 local $self->{_in_drain} = 1;
464 759
465 if ( 760 if (
466 defined $self->{rbuf_max} 761 defined $self->{rbuf_max}
467 && $self->{rbuf_max} < length $self->{rbuf} 762 && $self->{rbuf_max} < length $self->{rbuf}
468 ) { 763 ) {
469 $! = &Errno::ENOSPC; return $self->error; 764 $self->_error (&Errno::ENOSPC, 1), return;
470 } 765 }
471 766
472 return if $self->{in_drain}; 767 while () {
473 local $self->{in_drain} = 1; 768 # we need to use a separate tls read buffer, as we must not receive data while
769 # we are draining the buffer, and this can only happen with TLS.
770 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
474 771
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).
530 841
531You can access the read buffer directly as the C<< ->{rbuf} >> member, if 842You can access the read buffer directly as the C<< ->{rbuf} >>
532you want. 843member, if you want. However, the only operation allowed on the
844read buffer (apart from looking at it) is removing data from its
845beginning. Otherwise modifying or appending to it is not allowed and will
846lead to hard-to-track-down bugs.
533 847
534NOTE: The read buffer should only be used or modified if the C<on_read>, 848NOTE: The read buffer should only be used or modified if the C<on_read>,
535C<push_read> or C<unshift_read> methods are used. The other read methods 849C<push_read> or C<unshift_read> methods are used. The other read methods
536automatically manage the read buffer. 850automatically manage the read buffer.
537 851
577 891
578 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 892 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
579 ->($self, $cb, @_); 893 ->($self, $cb, @_);
580 } 894 }
581 895
582 push @{ $self->{queue} }, $cb; 896 push @{ $self->{_queue} }, $cb;
583 $self->_drain_rbuf; 897 $self->_drain_rbuf unless $self->{_in_drain};
584} 898}
585 899
586sub unshift_read { 900sub unshift_read {
587 my $self = shift; 901 my $self = shift;
588 my $cb = pop; 902 my $cb = pop;
593 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 907 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
594 ->($self, $cb, @_); 908 ->($self, $cb, @_);
595 } 909 }
596 910
597 911
598 unshift @{ $self->{queue} }, $cb; 912 unshift @{ $self->{_queue} }, $cb;
599 $self->_drain_rbuf; 913 $self->_drain_rbuf unless $self->{_in_drain};
600} 914}
601 915
602=item $handle->push_read (type => @args, $cb) 916=item $handle->push_read (type => @args, $cb)
603 917
604=item $handle->unshift_read (type => @args, $cb) 918=item $handle->unshift_read (type => @args, $cb)
610Predefined types are (if you have ideas for additional types, feel free to 924Predefined types are (if you have ideas for additional types, feel free to
611drop by and tell us): 925drop by and tell us):
612 926
613=over 4 927=over 4
614 928
615=item chunk => $octets, $cb->($self, $data) 929=item chunk => $octets, $cb->($handle, $data)
616 930
617Invoke the callback only once C<$octets> bytes have been read. Pass the 931Invoke 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 932data read to the callback. The callback will never be called with less
619data. 933data.
620 934
634 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 948 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635 1 949 1
636 } 950 }
637}; 951};
638 952
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, $eol) 953=item line => [$eol, ]$cb->($handle, $line, $eol)
649 954
650The callback will be called only once a full line (including the end of 955The callback will be called only once a full line (including the end of
651line marker, C<$eol>) has been read. This line (excluding the end of line 956line 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 957marker) will be passed to the callback as second argument (C<$line>), and
653the end of line marker as the third argument (C<$eol>). 958the end of line marker as the third argument (C<$eol>).
667=cut 972=cut
668 973
669register_read_type line => sub { 974register_read_type line => sub {
670 my ($self, $cb, $eol) = @_; 975 my ($self, $cb, $eol) = @_;
671 976
672 $eol = qr|(\015?\012)| if @_ < 3; 977 if (@_ < 3) {
978 # this is more than twice as fast as the generic code below
979 sub {
980 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
981
982 $cb->($_[0], $1, $2);
983 1
984 }
985 } else {
673 $eol = quotemeta $eol unless ref $eol; 986 $eol = quotemeta $eol unless ref $eol;
674 $eol = qr|^(.*?)($eol)|s; 987 $eol = qr|^(.*?)($eol)|s;
988
989 sub {
990 $_[0]{rbuf} =~ s/$eol// or return;
991
992 $cb->($_[0], $1, $2);
993 1
994 }
995 }
996};
997
998=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
999
1000Makes a regex match against the regex object C<$accept> and returns
1001everything up to and including the match.
1002
1003Example: read a single line terminated by '\n'.
1004
1005 $handle->push_read (regex => qr<\n>, sub { ... });
1006
1007If C<$reject> is given and not undef, then it determines when the data is
1008to be rejected: it is matched against the data when the C<$accept> regex
1009does not match and generates an C<EBADMSG> error when it matches. This is
1010useful to quickly reject wrong data (to avoid waiting for a timeout or a
1011receive buffer overflow).
1012
1013Example: expect a single decimal number followed by whitespace, reject
1014anything else (not the use of an anchor).
1015
1016 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1017
1018If C<$skip> is given and not C<undef>, then it will be matched against
1019the receive buffer when neither C<$accept> nor C<$reject> match,
1020and everything preceding and including the match will be accepted
1021unconditionally. This is useful to skip large amounts of data that you
1022know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1023have to start matching from the beginning. This is purely an optimisation
1024and is usually worth only when you expect more than a few kilobytes.
1025
1026Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1027expect the header to be very large (it isn't in practise, but...), we use
1028a skip regex to skip initial portions. The skip regex is tricky in that
1029it only accepts something not ending in either \015 or \012, as these are
1030required for the accept regex.
1031
1032 $handle->push_read (regex =>
1033 qr<\015\012\015\012>,
1034 undef, # no reject
1035 qr<^.*[^\015\012]>,
1036 sub { ... });
1037
1038=cut
1039
1040register_read_type regex => sub {
1041 my ($self, $cb, $accept, $reject, $skip) = @_;
1042
1043 my $data;
1044 my $rbuf = \$self->{rbuf};
675 1045
676 sub { 1046 sub {
677 $_[0]{rbuf} =~ s/$eol// or return; 1047 # accept
678 1048 if ($$rbuf =~ $accept) {
679 $cb->($_[0], $1, $2); 1049 $data .= substr $$rbuf, 0, $+[0], "";
1050 $cb->($self, $data);
1051 return 1;
1052 }
680 1 1053
1054 # reject
1055 if ($reject && $$rbuf =~ $reject) {
1056 $self->_error (&Errno::EBADMSG);
1057 }
1058
1059 # skip
1060 if ($skip && $$rbuf =~ $skip) {
1061 $data .= substr $$rbuf, 0, $+[0], "";
1062 }
1063
1064 ()
681 } 1065 }
682}; 1066};
683 1067
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) 1068=item netstring => $cb->($handle, $string)
696 1069
697A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1070A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698 1071
699Throws an error with C<$!> set to EBADMSG on format violations. 1072Throws an error with C<$!> set to EBADMSG on format violations.
700 1073
704 my ($self, $cb) = @_; 1077 my ($self, $cb) = @_;
705 1078
706 sub { 1079 sub {
707 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1080 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708 if ($_[0]{rbuf} =~ /[^0-9]/) { 1081 if ($_[0]{rbuf} =~ /[^0-9]/) {
709 $! = &Errno::EBADMSG; 1082 $self->_error (&Errno::EBADMSG);
710 $self->error;
711 } 1083 }
712 return; 1084 return;
713 } 1085 }
714 1086
715 my $len = $1; 1087 my $len = $1;
718 my $string = $_[1]; 1090 my $string = $_[1];
719 $_[0]->unshift_read (chunk => 1, sub { 1091 $_[0]->unshift_read (chunk => 1, sub {
720 if ($_[1] eq ",") { 1092 if ($_[1] eq ",") {
721 $cb->($_[0], $string); 1093 $cb->($_[0], $string);
722 } else { 1094 } else {
723 $! = &Errno::EBADMSG; 1095 $self->_error (&Errno::EBADMSG);
724 $self->error;
725 } 1096 }
726 }); 1097 });
727 }); 1098 });
728 1099
729 1 1100 1
730 } 1101 }
731}; 1102};
732 1103
1104=item packstring => $format, $cb->($handle, $string)
1105
1106An octet string prefixed with an encoded length. The encoding C<$format>
1107uses the same format as a Perl C<pack> format, but must specify a single
1108integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1109optional C<!>, C<< < >> or C<< > >> modifier).
1110
1111For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1112EPP uses a prefix of C<N> (4 octtes).
1113
1114Example: read a block of data prefixed by its length in BER-encoded
1115format (very efficient).
1116
1117 $handle->push_read (packstring => "w", sub {
1118 my ($handle, $data) = @_;
1119 });
1120
1121=cut
1122
1123register_read_type packstring => sub {
1124 my ($self, $cb, $format) = @_;
1125
1126 sub {
1127 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1128 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1129 or return;
1130
1131 $format = length pack $format, $len;
1132
1133 # bypass unshift if we already have the remaining chunk
1134 if ($format + $len <= length $_[0]{rbuf}) {
1135 my $data = substr $_[0]{rbuf}, $format, $len;
1136 substr $_[0]{rbuf}, 0, $format + $len, "";
1137 $cb->($_[0], $data);
1138 } else {
1139 # remove prefix
1140 substr $_[0]{rbuf}, 0, $format, "";
1141
1142 # read remaining chunk
1143 $_[0]->unshift_read (chunk => $len, $cb);
1144 }
1145
1146 1
1147 }
1148};
1149
1150=item json => $cb->($handle, $hash_or_arrayref)
1151
1152Reads a JSON object or array, decodes it and passes it to the
1153callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1154
1155If a C<json> object was passed to the constructor, then that will be used
1156for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1157
1158This read type uses the incremental parser available with JSON version
11592.09 (and JSON::XS version 2.2) and above. You have to provide a
1160dependency on your own: this module will load the JSON module, but
1161AnyEvent does not depend on it itself.
1162
1163Since JSON texts are fully self-delimiting, the C<json> read and write
1164types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1165the C<json> write type description, above, for an actual example.
1166
1167=cut
1168
1169register_read_type json => sub {
1170 my ($self, $cb) = @_;
1171
1172 require JSON;
1173
1174 my $data;
1175 my $rbuf = \$self->{rbuf};
1176
1177 my $json = $self->{json} ||= JSON->new->utf8;
1178
1179 sub {
1180 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1181
1182 if ($ref) {
1183 $self->{rbuf} = $json->incr_text;
1184 $json->incr_text = "";
1185 $cb->($self, $ref);
1186
1187 1
1188 } elsif ($@) {
1189 # error case
1190 $json->incr_skip;
1191
1192 $self->{rbuf} = $json->incr_text;
1193 $json->incr_text = "";
1194
1195 $self->_error (&Errno::EBADMSG);
1196
1197 ()
1198 } else {
1199 $self->{rbuf} = "";
1200
1201 ()
1202 }
1203 }
1204};
1205
1206=item storable => $cb->($handle, $ref)
1207
1208Deserialises a L<Storable> frozen representation as written by the
1209C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1210data).
1211
1212Raises C<EBADMSG> error if the data could not be decoded.
1213
1214=cut
1215
1216register_read_type storable => sub {
1217 my ($self, $cb) = @_;
1218
1219 require Storable;
1220
1221 sub {
1222 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1223 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1224 or return;
1225
1226 my $format = length pack "w", $len;
1227
1228 # bypass unshift if we already have the remaining chunk
1229 if ($format + $len <= length $_[0]{rbuf}) {
1230 my $data = substr $_[0]{rbuf}, $format, $len;
1231 substr $_[0]{rbuf}, 0, $format + $len, "";
1232 $cb->($_[0], Storable::thaw ($data));
1233 } else {
1234 # remove prefix
1235 substr $_[0]{rbuf}, 0, $format, "";
1236
1237 # read remaining chunk
1238 $_[0]->unshift_read (chunk => $len, sub {
1239 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1240 $cb->($_[0], $ref);
1241 } else {
1242 $self->_error (&Errno::EBADMSG);
1243 }
1244 });
1245 }
1246
1247 1
1248 }
1249};
1250
733=back 1251=back
734 1252
735=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1253=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
736 1254
737This function (not method) lets you add your own types to C<push_read>. 1255This function (not method) lets you add your own types to C<push_read>.
738 1256
739Whenever the given C<type> is used, C<push_read> will invoke the code 1257Whenever the given C<type> is used, C<push_read> will invoke the code
740reference with the handle object, the callback and the remaining 1258reference with the handle object, the callback and the remaining
742 1260
743The code reference is supposed to return a callback (usually a closure) 1261The code reference is supposed to return a callback (usually a closure)
744that works as a plain read callback (see C<< ->push_read ($cb) >>). 1262that works as a plain read callback (see C<< ->push_read ($cb) >>).
745 1263
746It should invoke the passed callback when it is done reading (remember to 1264It should invoke the passed callback when it is done reading (remember to
747pass C<$self> as first argument as all other callbacks do that). 1265pass C<$handle> as first argument as all other callbacks do that).
748 1266
749Note that this is a function, and all types registered this way will be 1267Note that this is a function, and all types registered this way will be
750global, so try to use unique names. 1268global, so try to use unique names.
751 1269
752For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1270For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
755=item $handle->stop_read 1273=item $handle->stop_read
756 1274
757=item $handle->start_read 1275=item $handle->start_read
758 1276
759In rare cases you actually do not want to read anything from the 1277In rare cases you actually do not want to read anything from the
760socket. In this case you can call C<stop_read>. Neither C<on_read> no 1278socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761any queued callbacks will be executed then. To start reading again, call 1279any queued callbacks will be executed then. To start reading again, call
762C<start_read>. 1280C<start_read>.
763 1281
1282Note that AnyEvent::Handle will automatically C<start_read> for you when
1283you change the C<on_read> callback or push/unshift a read callback, and it
1284will automatically C<stop_read> for you when neither C<on_read> is set nor
1285there are any read requests in the queue.
1286
1287These methods will have no effect when in TLS mode (as TLS doesn't support
1288half-duplex connections).
1289
764=cut 1290=cut
765 1291
766sub stop_read { 1292sub stop_read {
767 my ($self) = @_; 1293 my ($self) = @_;
768 1294
769 delete $self->{rw}; 1295 delete $self->{_rw} unless $self->{tls};
770} 1296}
771 1297
772sub start_read { 1298sub start_read {
773 my ($self) = @_; 1299 my ($self) = @_;
774 1300
775 unless ($self->{rw} || $self->{eof}) { 1301 unless ($self->{_rw} || $self->{_eof}) {
776 Scalar::Util::weaken $self; 1302 Scalar::Util::weaken $self;
777 1303
778 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1304 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
779 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1305 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1306 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781 1307
782 if ($len > 0) { 1308 if ($len > 0) {
783 $self->{filter_r} 1309 $self->{_activity} = AnyEvent->now;
784 ? $self->{filter_r}->($self, $rbuf) 1310
785 : $self->_drain_rbuf; 1311 if ($self->{tls}) {
1312 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1313
1314 &_dotls ($self);
1315 } else {
1316 $self->_drain_rbuf unless $self->{_in_drain};
1317 }
786 1318
787 } elsif (defined $len) { 1319 } elsif (defined $len) {
788 delete $self->{rw}; 1320 delete $self->{_rw};
789 $self->{eof} = 1; 1321 $self->{_eof} = 1;
790 $self->_drain_rbuf; 1322 $self->_drain_rbuf unless $self->{_in_drain};
791 1323
792 } elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAWOULDBLOCK) { 1324 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793 return $self->error; 1325 return $self->_error ($!, 1);
794 } 1326 }
795 }); 1327 });
796 } 1328 }
797} 1329}
798 1330
1331# poll the write BIO and send the data if applicable
799sub _dotls { 1332sub _dotls {
800 my ($self) = @_; 1333 my ($self) = @_;
801 1334
1335 my $tmp;
1336
802 if (length $self->{tls_wbuf}) { 1337 if (length $self->{_tls_wbuf}) {
803 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1338 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804 substr $self->{tls_wbuf}, 0, $len, ""; 1339 substr $self->{_tls_wbuf}, 0, $tmp, "";
805 } 1340 }
806 } 1341 }
807 1342
808 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1343 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1344 unless (length $tmp) {
1345 # let's treat SSL-eof as we treat normal EOF
1346 delete $self->{_rw};
1347 $self->{_eof} = 1;
1348 &_freetls;
1349 }
1350
1351 $self->{_tls_rbuf} .= $tmp;
1352 $self->_drain_rbuf unless $self->{_in_drain};
1353 $self->{tls} or return; # tls session might have gone away in callback
1354 }
1355
1356 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1357
1358 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1359 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1360 return $self->_error ($!, 1);
1361 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1362 return $self->_error (&Errno::EIO, 1);
1363 }
1364
1365 # all other errors are fine for our purposes
1366 }
1367
1368 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809 $self->{wbuf} .= $buf; 1369 $self->{wbuf} .= $tmp;
810 $self->_drain_wbuf; 1370 $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 } 1371 }
830} 1372}
831 1373
832=item $handle->starttls ($tls[, $tls_ctx]) 1374=item $handle->starttls ($tls[, $tls_ctx])
833 1375
839C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1381C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840 1382
841The second argument is the optional C<Net::SSLeay::CTX> object that is 1383The second argument is the optional C<Net::SSLeay::CTX> object that is
842used when AnyEvent::Handle has to create its own TLS connection object. 1384used when AnyEvent::Handle has to create its own TLS connection object.
843 1385
844=cut 1386The TLS connection object will end up in C<< $handle->{tls} >> after this
1387call and can be used or changed to your liking. Note that the handshake
1388might have already started when this function returns.
845 1389
846# TODO: maybe document... 1390If it an error to start a TLS handshake more than once per
1391AnyEvent::Handle object (this is due to bugs in OpenSSL).
1392
1393=cut
1394
847sub starttls { 1395sub starttls {
848 my ($self, $ssl, $ctx) = @_; 1396 my ($self, $ssl, $ctx) = @_;
849 1397
850 $self->stoptls; 1398 require Net::SSLeay;
851 1399
1400 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1401 if $self->{tls};
1402
852 if ($ssl eq "accept") { 1403 if ($ssl eq "accept") {
853 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1404 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
854 Net::SSLeay::set_accept_state ($ssl); 1405 Net::SSLeay::set_accept_state ($ssl);
855 } elsif ($ssl eq "connect") { 1406 } elsif ($ssl eq "connect") {
856 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1407 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
862 # basically, this is deep magic (because SSL_read should have the same issues) 1413 # 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". 1414 # but the openssl maintainers basically said: "trust us, it just works".
864 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1415 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
865 # and mismaintained ssleay-module doesn't even offer them). 1416 # and mismaintained ssleay-module doesn't even offer them).
866 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1417 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1418 #
1419 # in short: this is a mess.
1420 #
1421 # note that we do not try to keep the length constant between writes as we are required to do.
1422 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1423 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1424 # have identity issues in that area.
867 Net::SSLeay::CTX_set_mode ($self->{tls}, 1425 Net::SSLeay::CTX_set_mode ($self->{tls},
868 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1426 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1427 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
870 1428
871 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1430 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873 1431
874 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1432 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
875 1433
876 $self->{filter_w} = sub { 1434 &_dotls; # need to trigger the initial handshake
877 $_[0]{tls_wbuf} .= ${$_[1]}; 1435 $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} 1436}
885 1437
886=item $handle->stoptls 1438=item $handle->stoptls
887 1439
888Destroys the SSL connection, if any. Partial read or write data will be 1440Shuts down the SSL connection - this makes a proper EOF handshake by
889lost. 1441sending a close notify to the other side, but since OpenSSL doesn't
1442support non-blocking shut downs, it is not possible to re-use the stream
1443afterwards.
890 1444
891=cut 1445=cut
892 1446
893sub stoptls { 1447sub stoptls {
894 my ($self) = @_; 1448 my ($self) = @_;
895 1449
1450 if ($self->{tls}) {
1451 Net::SSLeay::shutdown ($self->{tls});
1452
1453 &_dotls;
1454
1455 # we don't give a shit. no, we do, but we can't. no...
1456 # we, we... have to use openssl :/
1457 &_freetls;
1458 }
1459}
1460
1461sub _freetls {
1462 my ($self) = @_;
1463
1464 return unless $self->{tls};
1465
896 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1466 Net::SSLeay::free (delete $self->{tls});
897 delete $self->{tls_rbio}; 1467
898 delete $self->{tls_wbio}; 1468 delete @$self{qw(_rbio _wbio _tls_wbuf)};
899 delete $self->{tls_wbuf};
900 delete $self->{filter_r};
901 delete $self->{filter_w};
902} 1469}
903 1470
904sub DESTROY { 1471sub DESTROY {
905 my $self = shift; 1472 my ($self) = @_;
906 1473
907 $self->stoptls; 1474 &_freetls;
1475
1476 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1477
1478 if ($linger && length $self->{wbuf}) {
1479 my $fh = delete $self->{fh};
1480 my $wbuf = delete $self->{wbuf};
1481
1482 my @linger;
1483
1484 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1485 my $len = syswrite $fh, $wbuf, length $wbuf;
1486
1487 if ($len > 0) {
1488 substr $wbuf, 0, $len, "";
1489 } else {
1490 @linger = (); # end
1491 }
1492 });
1493 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1494 @linger = ();
1495 });
1496 }
1497}
1498
1499=item $handle->destroy
1500
1501Shuts down the handle object as much as possible - this call ensures that
1502no further callbacks will be invoked and resources will be freed as much
1503as possible. You must not call any methods on the object afterwards.
1504
1505Normally, you can just "forget" any references to an AnyEvent::Handle
1506object and it will simply shut down. This works in fatal error and EOF
1507callbacks, as well as code outside. It does I<NOT> work in a read or write
1508callback, so when you want to destroy the AnyEvent::Handle object from
1509within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1510that case.
1511
1512The handle might still linger in the background and write out remaining
1513data, as specified by the C<linger> option, however.
1514
1515=cut
1516
1517sub destroy {
1518 my ($self) = @_;
1519
1520 $self->DESTROY;
1521 %$self = ();
908} 1522}
909 1523
910=item AnyEvent::Handle::TLS_CTX 1524=item AnyEvent::Handle::TLS_CTX
911 1525
912This function creates and returns the Net::SSLeay::CTX object used by 1526This function creates and returns the Net::SSLeay::CTX object used by
942 } 1556 }
943} 1557}
944 1558
945=back 1559=back
946 1560
1561
1562=head1 NONFREQUENTLY ASKED QUESTIONS
1563
1564=over 4
1565
1566=item I C<undef> the AnyEvent::Handle reference inside my callback and
1567still get further invocations!
1568
1569That's because AnyEvent::Handle keeps a reference to itself when handling
1570read or write callbacks.
1571
1572It is only safe to "forget" the reference inside EOF or error callbacks,
1573from within all other callbacks, you need to explicitly call the C<<
1574->destroy >> method.
1575
1576=item I get different callback invocations in TLS mode/Why can't I pause
1577reading?
1578
1579Unlike, say, TCP, TLS connections do not consist of two independent
1580communication channels, one for each direction. Or put differently. The
1581read and write directions are not independent of each other: you cannot
1582write data unless you are also prepared to read, and vice versa.
1583
1584This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1585callback invocations when you are not expecting any read data - the reason
1586is that AnyEvent::Handle always reads in TLS mode.
1587
1588During the connection, you have to make sure that you always have a
1589non-empty read-queue, or an C<on_read> watcher. At the end of the
1590connection (or when you no longer want to use it) you can call the
1591C<destroy> method.
1592
1593=item How do I read data until the other side closes the connection?
1594
1595If you just want to read your data into a perl scalar, the easiest way
1596to achieve this is by setting an C<on_read> callback that does nothing,
1597clearing the C<on_eof> callback and in the C<on_error> callback, the data
1598will be in C<$_[0]{rbuf}>:
1599
1600 $handle->on_read (sub { });
1601 $handle->on_eof (undef);
1602 $handle->on_error (sub {
1603 my $data = delete $_[0]{rbuf};
1604 undef $handle;
1605 });
1606
1607The reason to use C<on_error> is that TCP connections, due to latencies
1608and packets loss, might get closed quite violently with an error, when in
1609fact, all data has been received.
1610
1611It is usually better to use acknowledgements when transferring data,
1612to make sure the other side hasn't just died and you got the data
1613intact. This is also one reason why so many internet protocols have an
1614explicit QUIT command.
1615
1616=item I don't want to destroy the handle too early - how do I wait until
1617all data has been written?
1618
1619After writing your last bits of data, set the C<on_drain> callback
1620and destroy the handle in there - with the default setting of
1621C<low_water_mark> this will be called precisely when all data has been
1622written to the socket:
1623
1624 $handle->push_write (...);
1625 $handle->on_drain (sub {
1626 warn "all data submitted to the kernel\n";
1627 undef $handle;
1628 });
1629
1630=back
1631
1632
1633=head1 SUBCLASSING AnyEvent::Handle
1634
1635In many cases, you might want to subclass AnyEvent::Handle.
1636
1637To make this easier, a given version of AnyEvent::Handle uses these
1638conventions:
1639
1640=over 4
1641
1642=item * all constructor arguments become object members.
1643
1644At least initially, when you pass a C<tls>-argument to the constructor it
1645will end up in C<< $handle->{tls} >>. Those members might be changed or
1646mutated later on (for example C<tls> will hold the TLS connection object).
1647
1648=item * other object member names are prefixed with an C<_>.
1649
1650All object members not explicitly documented (internal use) are prefixed
1651with an underscore character, so the remaining non-C<_>-namespace is free
1652for use for subclasses.
1653
1654=item * all members not documented here and not prefixed with an underscore
1655are free to use in subclasses.
1656
1657Of course, new versions of AnyEvent::Handle may introduce more "public"
1658member variables, but thats just life, at least it is documented.
1659
1660=back
1661
947=head1 AUTHOR 1662=head1 AUTHOR
948 1663
949Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1664Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950 1665
951=cut 1666=cut

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