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Revision 1.37 by root, Mon May 26 20:02:22 2008 UTC vs.
Revision 1.130 by root, Mon Jun 29 21:00:32 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 = 4.45;
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
98The callbakc should throw an exception. If it returns, then
99AnyEvent::Handle will C<croak> for you.
100 119
101While 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
102you will not be notified of errors otherwise. The default simply calls 121you will not be notified of errors otherwise. The default simply calls
103die. 122C<croak>.
104 123
105=item on_read => $cb->($self) 124=item on_read => $cb->($handle)
106 125
107This sets the default read callback, which is called when data arrives 126This sets the default read callback, which is called when data arrives
108and 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).
109 130
110To 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 >>
111method 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.
112 135
113When 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
114feed 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
115calling 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
116error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
117 140
118=item on_drain => $cb->() 141=item on_drain => $cb->($handle)
119 142
120This 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
121(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).
122 145
123To append to the write buffer, use the C<< ->push_write >> method. 146To append to the write buffer, use the C<< ->push_write >> method.
124 147
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
125=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
126 176
127If 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>)
128when 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
129avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
130 180
131For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
132be 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
133(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
134amount 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
135isn't finished). 185isn't finished).
136 186
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
137=item read_size => <bytes> 213=item read_size => <bytes>
138 214
139The 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
140on each [loop iteration). Default: C<4096>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
141 218
142=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
143 220
144Sets 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
145buffer: 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
146considered empty. 223considered empty.
147 224
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
148=item tls => "accept" | "connect" | Net::SSLeay::SSL object 242=item tls => "accept" | "connect" | Net::SSLeay::SSL object
149 243
150When this parameter is given, it enables TLS (SSL) mode, that means it 244When this parameter is given, it enables TLS (SSL) mode, that means
151will start making tls handshake and will transparently encrypt/decrypt 245AnyEvent will start a TLS handshake as soon as the conenction has been
152data. 246established and will transparently encrypt/decrypt data afterwards.
153 247
154TLS mode requires Net::SSLeay to be installed (it will be loaded 248TLS mode requires Net::SSLeay to be installed (it will be loaded
155automatically 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.
156 252
157For 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
158connection, use C<connect> mode. 254C<accept>, and for the TLS client side of a connection, use C<connect>
255mode.
159 256
160You can also provide your own TLS connection object, but you have 257You can also provide your own TLS connection object, but you have
161to 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>
162or 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
163AnyEvent::Handle. 260AnyEvent::Handle.
164 261
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
165See 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.
166 268
167=item tls_ctx => $ssl_ctx 269=item tls_ctx => $ssl_ctx
168 270
169Use 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
170(unless a connection object was specified directly). If this parameter is 272(unless a connection object was specified directly). If this parameter is
171missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 273missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
172 274
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
173=back 286=back
174 287
175=cut 288=cut
176 289
177sub new { 290sub new {
181 294
182 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
183 296
184 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
185 298
186 if ($self->{tls}) {
187 require Net::SSLeay;
188 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
189 } 300 if $self->{tls};
190 301
191 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 302 $self->{_activity} = AnyEvent->now;
192 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 303 $self->_timeout;
304
193 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
194 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 306 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
195 307
196 $self->start_read; 308 $self->start_read
309 if $self->{on_read};
197 310
198 $self 311 $self
199} 312}
200 313
201sub _shutdown { 314sub _shutdown {
202 my ($self) = @_; 315 my ($self) = @_;
203 316
204 delete $self->{rw}; 317 delete @$self{qw(_tw _rw _ww fh rbuf wbuf on_read _queue)};
205 delete $self->{ww};
206 delete $self->{fh};
207}
208 318
319 &_freetls;
320}
321
209sub error { 322sub _error {
210 my ($self) = @_; 323 my ($self, $errno, $fatal) = @_;
211 324
212 {
213 local $!;
214 $self->_shutdown; 325 $self->_shutdown
215 } 326 if $fatal;
216 327
217 $self->{on_error}($self) 328 $! = $errno;
329
218 if $self->{on_error}; 330 if ($self->{on_error}) {
219 331 $self->{on_error}($self, $fatal);
332 } elsif ($self->{fh}) {
220 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 333 Carp::croak "AnyEvent::Handle uncaught error: $!";
334 }
221} 335}
222 336
223=item $fh = $handle->fh 337=item $fh = $handle->fh
224 338
225This 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.
226 340
227=cut 341=cut
228 342
229sub fh { $_[0]->{fh} } 343sub fh { $_[0]{fh} }
230 344
231=item $handle->on_error ($cb) 345=item $handle->on_error ($cb)
232 346
233Replace 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).
234 348
246 360
247sub on_eof { 361sub on_eof {
248 $_[0]{on_eof} = $_[1]; 362 $_[0]{on_eof} = $_[1];
249} 363}
250 364
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 $self->{_tw};
456 }
457}
458
251############################################################################# 459#############################################################################
252 460
253=back 461=back
254 462
255=head2 WRITE QUEUE 463=head2 WRITE QUEUE
276 my ($self, $cb) = @_; 484 my ($self, $cb) = @_;
277 485
278 $self->{on_drain} = $cb; 486 $self->{on_drain} = $cb;
279 487
280 $cb->($self) 488 $cb->($self)
281 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 489 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
282} 490}
283 491
284=item $handle->push_write ($data) 492=item $handle->push_write ($data)
285 493
286Queues 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
290=cut 498=cut
291 499
292sub _drain_wbuf { 500sub _drain_wbuf {
293 my ($self) = @_; 501 my ($self) = @_;
294 502
295 if (!$self->{ww} && length $self->{wbuf}) { 503 if (!$self->{_ww} && length $self->{wbuf}) {
296 504
297 Scalar::Util::weaken $self; 505 Scalar::Util::weaken $self;
298 506
299 my $cb = sub { 507 my $cb = sub {
300 my $len = syswrite $self->{fh}, $self->{wbuf}; 508 my $len = syswrite $self->{fh}, $self->{wbuf};
301 509
302 if ($len >= 0) { 510 if ($len >= 0) {
303 substr $self->{wbuf}, 0, $len, ""; 511 substr $self->{wbuf}, 0, $len, "";
304 512
513 $self->{_activity} = AnyEvent->now;
514
305 $self->{on_drain}($self) 515 $self->{on_drain}($self)
306 if $self->{low_water_mark} >= length $self->{wbuf} 516 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
307 && $self->{on_drain}; 517 && $self->{on_drain};
308 518
309 delete $self->{ww} unless length $self->{wbuf}; 519 delete $self->{_ww} unless length $self->{wbuf};
310 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAWOULDBLOCK) { 520 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
311 $self->error; 521 $self->_error ($!, 1);
312 } 522 }
313 }; 523 };
314 524
315 # try to write data immediately 525 # try to write data immediately
316 $cb->(); 526 $cb->() unless $self->{autocork};
317 527
318 # if still data left in wbuf, we need to poll 528 # if still data left in wbuf, we need to poll
319 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 529 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
320 if length $self->{wbuf}; 530 if length $self->{wbuf};
321 }; 531 };
322} 532}
323 533
324our %WH; 534our %WH;
335 545
336 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 546 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
337 ->($self, @_); 547 ->($self, @_);
338 } 548 }
339 549
340 if ($self->{filter_w}) { 550 if ($self->{tls}) {
341 $self->{filter_w}->($self, \$_[0]); 551 $self->{_tls_wbuf} .= $_[0];
552
553 &_dotls ($self);
342 } else { 554 } else {
343 $self->{wbuf} .= $_[0]; 555 $self->{wbuf} .= $_[0];
344 $self->_drain_wbuf; 556 $self->_drain_wbuf;
345 } 557 }
346} 558}
347 559
348=item $handle->push_write (type => @args) 560=item $handle->push_write (type => @args)
349 561
350=item $handle->unshift_write (type => @args)
351
352Instead 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
353the job by specifying a type and type-specific arguments. 563the job by specifying a type and type-specific arguments.
354 564
355Predefined 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
356drop by and tell us): 566drop by and tell us):
360=item netstring => $string 570=item netstring => $string
361 571
362Formats the given value as netstring 572Formats the given value as netstring
363(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 573(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
364 574
365=back
366
367=cut 575=cut
368 576
369register_write_type netstring => sub { 577register_write_type netstring => sub {
370 my ($self, $string) = @_; 578 my ($self, $string) = @_;
371 579
372 sprintf "%d:%s,", (length $string), $string 580 (length $string) . ":$string,"
373}; 581};
374 582
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
375=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 656=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
376 657
377This 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>.
378Whenever 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
379reference with the handle object and the remaining arguments. 660reference with the handle object and the remaining arguments.
380 661
399ways, 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
400a queue. 681a queue.
401 682
402In 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
403new 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
404enough 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
405or not. 686leave the data there if you want to accumulate more (e.g. when only a
687partial message has been received so far).
406 688
407In 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
408case, AnyEvent::Handle will call the first queued callback each time new 690case, AnyEvent::Handle will call the first queued callback each time new
409data 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
410below). 692done its job (see C<push_read>, below).
411 693
412This 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
413a chunk of data, and AnyEvent::Handle will execute them in order. 695a chunk of data, and AnyEvent::Handle will execute them in order.
414 696
415Example 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
416the specified number of bytes which give an XML datagram. 698the specified number of bytes which give an XML datagram.
417 699
418 # in the default state, expect some header bytes 700 # in the default state, expect some header bytes
419 $handle->on_read (sub { 701 $handle->on_read (sub {
420 # 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)
421 shift->unshift_read_chunk (4, sub { 703 shift->unshift_read (chunk => 4, sub {
422 # header arrived, decode 704 # header arrived, decode
423 my $len = unpack "N", $_[1]; 705 my $len = unpack "N", $_[1];
424 706
425 # now read the payload 707 # now read the payload
426 shift->unshift_read_chunk ($len, sub { 708 shift->unshift_read (chunk => $len, sub {
427 my $xml = $_[1]; 709 my $xml = $_[1];
428 # handle xml 710 # handle xml
429 }); 711 });
430 }); 712 });
431 }); 713 });
432 714
433Example 2: Implement a client for a protocol that replies either with 715Example 2: Implement a client for a protocol that replies either with "OK"
434"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
435second 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
436pipeline sending both requests and manipulate the queue as necessary in 718just pipeline sending both requests and manipulate the queue as necessary
437the callbacks: 719in the callbacks.
438 720
439 # 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"
440 $handle->push_write ("request 1\015\012"); 726 $handle->push_write ("request 1\015\012");
441 727
442 # 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
443 $handle->push_read_line (sub { 729 $handle->push_read (line => sub {
444 # if we got an "OK", we have to _prepend_ another line, 730 # if we got an "OK", we have to _prepend_ another line,
445 # so it will be read before the second request reads its 64 bytes 731 # so it will be read before the second request reads its 64 bytes
446 # which are already in the queue when this callback is called 732 # which are already in the queue when this callback is called
447 # we don't do this in case we got an error 733 # we don't do this in case we got an error
448 if ($_[1] eq "OK") { 734 if ($_[1] eq "OK") {
449 $_[0]->unshift_read_line (sub { 735 $_[0]->unshift_read (line => sub {
450 my $response = $_[1]; 736 my $response = $_[1];
451 ... 737 ...
452 }); 738 });
453 } 739 }
454 }); 740 });
455 741
456 # request two 742 # request two, simply returns 64 octets
457 $handle->push_write ("request 2\015\012"); 743 $handle->push_write ("request 2\015\012");
458 744
459 # simply read 64 bytes, always 745 # simply read 64 bytes, always
460 $handle->push_read_chunk (64, sub { 746 $handle->push_read (chunk => 64, sub {
461 my $response = $_[1]; 747 my $response = $_[1];
462 ... 748 ...
463 }); 749 });
464 750
465=over 4 751=over 4
466 752
467=cut 753=cut
468 754
469sub _drain_rbuf { 755sub _drain_rbuf {
470 my ($self) = @_; 756 my ($self) = @_;
757
758 local $self->{_in_drain} = 1;
471 759
472 if ( 760 if (
473 defined $self->{rbuf_max} 761 defined $self->{rbuf_max}
474 && $self->{rbuf_max} < length $self->{rbuf} 762 && $self->{rbuf_max} < length $self->{rbuf}
475 ) { 763 ) {
476 $! = &Errno::ENOSPC; 764 $self->_error (&Errno::ENOSPC, 1), return;
477 $self->error;
478 } 765 }
479 766
480 return if $self->{in_drain}; 767 while () {
481 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};
482 771
483 while (my $len = length $self->{rbuf}) { 772 my $len = length $self->{rbuf};
484 no strict 'refs'; 773
485 if (my $cb = shift @{ $self->{queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
486 unless ($cb->($self)) { 775 unless ($cb->($self)) {
487 if ($self->{eof}) { 776 if ($self->{_eof}) {
488 # 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)
489 $! = &Errno::EPIPE; 778 $self->_error (&Errno::EPIPE, 1), return;
490 $self->error;
491 } 779 }
492 780
493 unshift @{ $self->{queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
494 return; 782 last;
495 } 783 }
496 } elsif ($self->{on_read}) { 784 } elsif ($self->{on_read}) {
785 last unless $len;
786
497 $self->{on_read}($self); 787 $self->{on_read}($self);
498 788
499 if ( 789 if (
500 $self->{eof} # if no further data will arrive
501 && $len == length $self->{rbuf} # and no data has been consumed 790 $len == length $self->{rbuf} # if no data has been consumed
502 && !@{ $self->{queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
503 && $self->{on_read} # and we still want to read data 792 && $self->{on_read} # but we still have on_read
504 ) { 793 ) {
794 # no further data will arrive
505 # then no progress can be made 795 # so no progress can be made
506 $! = &Errno::EPIPE; 796 $self->_error (&Errno::EPIPE, 1), return
507 $self->error; 797 if $self->{_eof};
798
799 last; # more data might arrive
508 } 800 }
509 } else { 801 } else {
510 # read side becomes idle 802 # read side becomes idle
511 delete $self->{rw}; 803 delete $self->{_rw} unless $self->{tls};
512 return; 804 last;
513 } 805 }
514 } 806 }
515 807
516 if ($self->{eof}) { 808 if ($self->{_eof}) {
517 $self->_shutdown; 809 if ($self->{on_eof}) {
518 $self->{on_eof}($self) 810 $self->{on_eof}($self)
519 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} };
520 } 820 }
521} 821}
522 822
523=item $handle->on_read ($cb) 823=item $handle->on_read ($cb)
524 824
530 830
531sub on_read { 831sub on_read {
532 my ($self, $cb) = @_; 832 my ($self, $cb) = @_;
533 833
534 $self->{on_read} = $cb; 834 $self->{on_read} = $cb;
835 $self->_drain_rbuf if $cb && !$self->{_in_drain};
535} 836}
536 837
537=item $handle->rbuf 838=item $handle->rbuf
538 839
539Returns the read buffer (as a modifiable lvalue). 840Returns the read buffer (as a modifiable lvalue).
540 841
541You can access the read buffer directly as the C<< ->{rbuf} >> member, if 842You can access the read buffer directly as the C<< ->{rbuf} >>
542you 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.
543 847
544NOTE: 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>,
545C<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
546automatically manage the read buffer. 850automatically manage the read buffer.
547 851
587 891
588 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 892 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
589 ->($self, $cb, @_); 893 ->($self, $cb, @_);
590 } 894 }
591 895
592 push @{ $self->{queue} }, $cb; 896 push @{ $self->{_queue} }, $cb;
593 $self->_drain_rbuf; 897 $self->_drain_rbuf unless $self->{_in_drain};
594} 898}
595 899
596sub unshift_read { 900sub unshift_read {
597 my $self = shift; 901 my $self = shift;
598 my $cb = pop; 902 my $cb = pop;
603 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 907 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
604 ->($self, $cb, @_); 908 ->($self, $cb, @_);
605 } 909 }
606 910
607 911
608 unshift @{ $self->{queue} }, $cb; 912 unshift @{ $self->{_queue} }, $cb;
609 $self->_drain_rbuf; 913 $self->_drain_rbuf unless $self->{_in_drain};
610} 914}
611 915
612=item $handle->push_read (type => @args, $cb) 916=item $handle->push_read (type => @args, $cb)
613 917
614=item $handle->unshift_read (type => @args, $cb) 918=item $handle->unshift_read (type => @args, $cb)
620Predefined 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
621drop by and tell us): 925drop by and tell us):
622 926
623=over 4 927=over 4
624 928
625=item chunk => $octets, $cb->($self, $data) 929=item chunk => $octets, $cb->($handle, $data)
626 930
627Invoke the callback only once C<$octets> bytes have been read. Pass the 931Invoke the callback only once C<$octets> bytes have been read. Pass the
628data 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
629data. 933data.
630 934
644 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 948 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
645 1 949 1
646 } 950 }
647}; 951};
648 952
649# compatibility with older API
650sub push_read_chunk {
651 $_[0]->push_read (chunk => $_[1], $_[2]);
652}
653
654sub unshift_read_chunk {
655 $_[0]->unshift_read (chunk => $_[1], $_[2]);
656}
657
658=item line => [$eol, ]$cb->($self, $line, $eol) 953=item line => [$eol, ]$cb->($handle, $line, $eol)
659 954
660The callback will be called only once a full line (including the end of 955The callback will be called only once a full line (including the end of
661line marker, C<$eol>) has been read. This line (excluding the end of line 956line marker, C<$eol>) has been read. This line (excluding the end of line
662marker) will be passed to the callback as second argument (C<$line>), and 957marker) will be passed to the callback as second argument (C<$line>), and
663the end of line marker as the third argument (C<$eol>). 958the end of line marker as the third argument (C<$eol>).
677=cut 972=cut
678 973
679register_read_type line => sub { 974register_read_type line => sub {
680 my ($self, $cb, $eol) = @_; 975 my ($self, $cb, $eol) = @_;
681 976
682 $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 {
683 $eol = quotemeta $eol unless ref $eol; 986 $eol = quotemeta $eol unless ref $eol;
684 $eol = qr|^(.*?)($eol)|s; 987 $eol = qr|^(.*?)($eol)|s;
685 988
686 sub { 989 sub {
687 $_[0]{rbuf} =~ s/$eol// or return; 990 $_[0]{rbuf} =~ s/$eol// or return;
688 991
689 $cb->($_[0], $1, $2); 992 $cb->($_[0], $1, $2);
993 1
690 1 994 }
691 } 995 }
692}; 996};
693 997
694# compatibility with older API
695sub push_read_line {
696 my $self = shift;
697 $self->push_read (line => @_);
698}
699
700sub unshift_read_line {
701 my $self = shift;
702 $self->unshift_read (line => @_);
703}
704
705=item netstring => $cb->($string)
706
707A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
708
709Throws an error with C<$!> set to EBADMSG on format violations.
710
711=cut
712
713register_read_type netstring => sub {
714 my ($self, $cb) = @_;
715
716 sub {
717 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
718 if ($_[0]{rbuf} =~ /[^0-9]/) {
719 $! = &Errno::EBADMSG;
720 $self->error;
721 }
722 return;
723 }
724
725 my $len = $1;
726
727 $self->unshift_read (chunk => $len, sub {
728 my $string = $_[1];
729 $_[0]->unshift_read (chunk => 1, sub {
730 if ($_[1] eq ",") {
731 $cb->($_[0], $string);
732 } else {
733 $! = &Errno::EBADMSG;
734 $self->error;
735 }
736 });
737 });
738
739 1
740 }
741};
742
743=item regex => $accept[, $reject[, $skip], $cb->($data) 998=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
744 999
745Makes a regex match against the regex object C<$accept> and returns 1000Makes a regex match against the regex object C<$accept> and returns
746everything up to and including the match. 1001everything up to and including the match.
747 1002
748Example: read a single line terminated by '\n'. 1003Example: read a single line terminated by '\n'.
796 return 1; 1051 return 1;
797 } 1052 }
798 1053
799 # reject 1054 # reject
800 if ($reject && $$rbuf =~ $reject) { 1055 if ($reject && $$rbuf =~ $reject) {
801 $! = &Errno::EBADMSG; 1056 $self->_error (&Errno::EBADMSG);
802 $self->error;
803 } 1057 }
804 1058
805 # skip 1059 # skip
806 if ($skip && $$rbuf =~ $skip) { 1060 if ($skip && $$rbuf =~ $skip) {
807 $data .= substr $$rbuf, 0, $+[0], ""; 1061 $data .= substr $$rbuf, 0, $+[0], "";
809 1063
810 () 1064 ()
811 } 1065 }
812}; 1066};
813 1067
1068=item netstring => $cb->($handle, $string)
1069
1070A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1071
1072Throws an error with C<$!> set to EBADMSG on format violations.
1073
1074=cut
1075
1076register_read_type netstring => sub {
1077 my ($self, $cb) = @_;
1078
1079 sub {
1080 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1081 if ($_[0]{rbuf} =~ /[^0-9]/) {
1082 $self->_error (&Errno::EBADMSG);
1083 }
1084 return;
1085 }
1086
1087 my $len = $1;
1088
1089 $self->unshift_read (chunk => $len, sub {
1090 my $string = $_[1];
1091 $_[0]->unshift_read (chunk => 1, sub {
1092 if ($_[1] eq ",") {
1093 $cb->($_[0], $string);
1094 } else {
1095 $self->_error (&Errno::EBADMSG);
1096 }
1097 });
1098 });
1099
1100 1
1101 }
1102};
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
814=back 1251=back
815 1252
816=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1253=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
817 1254
818This function (not method) lets you add your own types to C<push_read>. 1255This function (not method) lets you add your own types to C<push_read>.
819 1256
820Whenever the given C<type> is used, C<push_read> will invoke the code 1257Whenever the given C<type> is used, C<push_read> will invoke the code
821reference with the handle object, the callback and the remaining 1258reference with the handle object, the callback and the remaining
823 1260
824The code reference is supposed to return a callback (usually a closure) 1261The code reference is supposed to return a callback (usually a closure)
825that works as a plain read callback (see C<< ->push_read ($cb) >>). 1262that works as a plain read callback (see C<< ->push_read ($cb) >>).
826 1263
827It should invoke the passed callback when it is done reading (remember to 1264It should invoke the passed callback when it is done reading (remember to
828pass C<$self> as first argument as all other callbacks do that). 1265pass C<$handle> as first argument as all other callbacks do that).
829 1266
830Note 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
831global, so try to use unique names. 1268global, so try to use unique names.
832 1269
833For 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>,
836=item $handle->stop_read 1273=item $handle->stop_read
837 1274
838=item $handle->start_read 1275=item $handle->start_read
839 1276
840In rare cases you actually do not want to read anything from the 1277In rare cases you actually do not want to read anything from the
841socket. In this case you can call C<stop_read>. Neither C<on_read> no 1278socket. In this case you can call C<stop_read>. Neither C<on_read> nor
842any queued callbacks will be executed then. To start reading again, call 1279any queued callbacks will be executed then. To start reading again, call
843C<start_read>. 1280C<start_read>.
844 1281
1282Note that AnyEvent::Handle will automatically C<start_read> for you when
1283you change the C<on_read> callback or push/unshift a read callback, and it
1284will automatically C<stop_read> for you when neither C<on_read> is set nor
1285there are any read requests in the queue.
1286
1287These methods will have no effect when in TLS mode (as TLS doesn't support
1288half-duplex connections).
1289
845=cut 1290=cut
846 1291
847sub stop_read { 1292sub stop_read {
848 my ($self) = @_; 1293 my ($self) = @_;
849 1294
850 delete $self->{rw}; 1295 delete $self->{_rw} unless $self->{tls};
851} 1296}
852 1297
853sub start_read { 1298sub start_read {
854 my ($self) = @_; 1299 my ($self) = @_;
855 1300
856 unless ($self->{rw} || $self->{eof}) { 1301 unless ($self->{_rw} || $self->{_eof}) {
857 Scalar::Util::weaken $self; 1302 Scalar::Util::weaken $self;
858 1303
859 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1304 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
860 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1305 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
861 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;
862 1307
863 if ($len > 0) { 1308 if ($len > 0) {
864 $self->{filter_r} 1309 $self->{_activity} = AnyEvent->now;
865 ? $self->{filter_r}->($self, $rbuf) 1310
866 : $self->_drain_rbuf; 1311 if ($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 }
867 1318
868 } elsif (defined $len) { 1319 } elsif (defined $len) {
869 delete $self->{rw}; 1320 delete $self->{_rw};
870 $self->{eof} = 1; 1321 $self->{_eof} = 1;
871 $self->_drain_rbuf; 1322 $self->_drain_rbuf unless $self->{_in_drain};
872 1323
873 } elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAWOULDBLOCK) { 1324 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
874 return $self->error; 1325 return $self->_error ($!, 1);
875 } 1326 }
876 }); 1327 });
877 } 1328 }
878} 1329}
879 1330
1331# poll the write BIO and send the data if applicable
880sub _dotls { 1332sub _dotls {
881 my ($self) = @_; 1333 my ($self) = @_;
882 1334
1335 my $tmp;
1336
883 if (length $self->{tls_wbuf}) { 1337 if (length $self->{_tls_wbuf}) {
884 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1338 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
885 substr $self->{tls_wbuf}, 0, $len, ""; 1339 substr $self->{_tls_wbuf}, 0, $tmp, "";
886 } 1340 }
887 } 1341 }
888 1342
889 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}))) {
890 $self->{wbuf} .= $buf; 1369 $self->{wbuf} .= $tmp;
891 $self->_drain_wbuf; 1370 $self->_drain_wbuf;
892 }
893
894 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
895 $self->{rbuf} .= $buf;
896 $self->_drain_rbuf;
897 }
898
899 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
900
901 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
902 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
903 $self->error;
904 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
905 $! = &Errno::EIO;
906 $self->error;
907 }
908
909 # all others are fine for our purposes
910 } 1371 }
911} 1372}
912 1373
913=item $handle->starttls ($tls[, $tls_ctx]) 1374=item $handle->starttls ($tls[, $tls_ctx])
914 1375
920C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1381C<"connect">, C<"accept"> or an existing Net::SSLeay object).
921 1382
922The 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
923used when AnyEvent::Handle has to create its own TLS connection object. 1384used when AnyEvent::Handle has to create its own TLS connection object.
924 1385
925=cut 1386The TLS connection object will end up in C<< $handle->{tls} >> after this
1387call and can be used or changed to your liking. Note that the handshake
1388might have already started when this function returns.
926 1389
927# TODO: maybe document... 1390If it an error to start a TLS handshake more than once per
1391AnyEvent::Handle object (this is due to bugs in OpenSSL).
1392
1393=cut
1394
928sub starttls { 1395sub starttls {
929 my ($self, $ssl, $ctx) = @_; 1396 my ($self, $ssl, $ctx) = @_;
930 1397
931 $self->stoptls; 1398 require Net::SSLeay;
932 1399
1400 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1401 if $self->{tls};
1402
933 if ($ssl eq "accept") { 1403 if ($ssl eq "accept") {
934 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1404 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
935 Net::SSLeay::set_accept_state ($ssl); 1405 Net::SSLeay::set_accept_state ($ssl);
936 } elsif ($ssl eq "connect") { 1406 } elsif ($ssl eq "connect") {
937 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1407 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
943 # 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)
944 # but the openssl maintainers basically said: "trust us, it just works". 1414 # but the openssl maintainers basically said: "trust us, it just works".
945 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1415 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
946 # and mismaintained ssleay-module doesn't even offer them). 1416 # and mismaintained ssleay-module doesn't even offer them).
947 # 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.
948 Net::SSLeay::CTX_set_mode ($self->{tls}, 1425 Net::SSLeay::CTX_set_mode ($self->{tls},
949 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1426 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
950 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1427 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
951 1428
952 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
953 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1430 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
954 1431
955 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1432 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
956 1433
957 $self->{filter_w} = sub { 1434 &_dotls; # need to trigger the initial handshake
958 $_[0]{tls_wbuf} .= ${$_[1]}; 1435 $self->start_read; # make sure we actually do read
959 &_dotls;
960 };
961 $self->{filter_r} = sub {
962 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
963 &_dotls;
964 };
965} 1436}
966 1437
967=item $handle->stoptls 1438=item $handle->stoptls
968 1439
969Destroys the SSL connection, if any. Partial read or write data will be 1440Shuts down the SSL connection - this makes a proper EOF handshake by
970lost. 1441sending a close notify to the other side, but since OpenSSL doesn't
1442support non-blocking shut downs, it is not possible to re-use the stream
1443afterwards.
971 1444
972=cut 1445=cut
973 1446
974sub stoptls { 1447sub stoptls {
975 my ($self) = @_; 1448 my ($self) = @_;
976 1449
1450 if ($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
977 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1466 Net::SSLeay::free (delete $self->{tls});
978 delete $self->{tls_rbio}; 1467
979 delete $self->{tls_wbio}; 1468 delete @$self{qw(_rbio _wbio _tls_wbuf)};
980 delete $self->{tls_wbuf};
981 delete $self->{filter_r};
982 delete $self->{filter_w};
983} 1469}
984 1470
985sub DESTROY { 1471sub DESTROY {
986 my $self = shift; 1472 my ($self) = @_;
987 1473
988 $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 = ();
989} 1522}
990 1523
991=item AnyEvent::Handle::TLS_CTX 1524=item AnyEvent::Handle::TLS_CTX
992 1525
993This function creates and returns the Net::SSLeay::CTX object used by 1526This function creates and returns the Net::SSLeay::CTX object used by
1023 } 1556 }
1024} 1557}
1025 1558
1026=back 1559=back
1027 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
1028=head1 AUTHOR 1662=head1 AUTHOR
1029 1663
1030Robin 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>.
1031 1665
1032=cut 1666=cut

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