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Revision 1.40 by root, Tue May 27 05:36:27 2008 UTC vs.
Revision 1.127 by root, Tue Jun 23 23:37:32 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 = 4.412;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called 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 => $cb->($handle) 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 callback 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 => $cb->($handle) 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<$handle->{rbuf}> member directly. 132method or access the C<$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>).
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
173=item json => JSON or JSON::XS object 275=item json => JSON or JSON::XS object
174 276
175This is the json coder object used by the C<json> read and write types. 277This is the json coder object used by the C<json> read and write types.
176 278
177If you don't supply it, then AnyEvent::Handle will use C<encode_json> and 279If you don't supply it, then AnyEvent::Handle will create and use a
178C<decode_json>. 280suitable one (on demand), which will write and expect UTF-8 encoded JSON
281texts.
179 282
180Note that you are responsible to depend on the JSON module if you want to 283Note that you are responsible to depend on the JSON module if you want to
181use this functionality, as AnyEvent does not have a dependency itself. 284use this functionality, as AnyEvent does not have a dependency itself.
182 285
183=item filter_r => $cb
184
185=item filter_w => $cb
186
187These exist, but are undocumented at this time.
188
189=back 286=back
190 287
191=cut 288=cut
192 289
193sub new { 290sub new {
197 294
198 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
199 296
200 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
201 298
202 if ($self->{tls}) {
203 require Net::SSLeay;
204 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
205 } 300 if $self->{tls};
206 301
207 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 302 $self->{_activity} = AnyEvent->now;
208 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 303 $self->_timeout;
304
209 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
210 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 306 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
211 307
212 $self->start_read; 308 $self->start_read
309 if $self->{on_read};
213 310
214 $self 311 $self
215} 312}
216 313
217sub _shutdown { 314sub _shutdown {
218 my ($self) = @_; 315 my ($self) = @_;
219 316
317 delete $self->{_tw};
220 delete $self->{_rw}; 318 delete $self->{_rw};
221 delete $self->{_ww}; 319 delete $self->{_ww};
222 delete $self->{fh}; 320 delete $self->{fh};
223}
224 321
322 &_freetls;
323
324 delete $self->{on_read};
325 delete $self->{_queue};
326}
327
225sub error { 328sub _error {
226 my ($self) = @_; 329 my ($self, $errno, $fatal) = @_;
227 330
228 {
229 local $!;
230 $self->_shutdown; 331 $self->_shutdown
231 } 332 if $fatal;
232 333
233 $self->{on_error}($self) 334 $! = $errno;
335
234 if $self->{on_error}; 336 if ($self->{on_error}) {
235 337 $self->{on_error}($self, $fatal);
338 } elsif ($self->{fh}) {
236 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 339 Carp::croak "AnyEvent::Handle uncaught error: $!";
340 }
237} 341}
238 342
239=item $fh = $handle->fh 343=item $fh = $handle->fh
240 344
241This method returns the file handle of the L<AnyEvent::Handle> object. 345This method returns the file handle used to create the L<AnyEvent::Handle> object.
242 346
243=cut 347=cut
244 348
245sub fh { $_[0]{fh} } 349sub fh { $_[0]{fh} }
246 350
262 366
263sub on_eof { 367sub on_eof {
264 $_[0]{on_eof} = $_[1]; 368 $_[0]{on_eof} = $_[1];
265} 369}
266 370
371=item $handle->on_timeout ($cb)
372
373Replace the current C<on_timeout> callback, or disables the callback (but
374not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
375argument and method.
376
377=cut
378
379sub on_timeout {
380 $_[0]{on_timeout} = $_[1];
381}
382
383=item $handle->autocork ($boolean)
384
385Enables or disables the current autocork behaviour (see C<autocork>
386constructor argument). Changes will only take effect on the next write.
387
388=cut
389
390sub autocork {
391 $_[0]{autocork} = $_[1];
392}
393
394=item $handle->no_delay ($boolean)
395
396Enables or disables the C<no_delay> setting (see constructor argument of
397the same name for details).
398
399=cut
400
401sub no_delay {
402 $_[0]{no_delay} = $_[1];
403
404 eval {
405 local $SIG{__DIE__};
406 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
407 };
408}
409
410#############################################################################
411
412=item $handle->timeout ($seconds)
413
414Configures (or disables) the inactivity timeout.
415
416=cut
417
418sub timeout {
419 my ($self, $timeout) = @_;
420
421 $self->{timeout} = $timeout;
422 $self->_timeout;
423}
424
425# reset the timeout watcher, as neccessary
426# also check for time-outs
427sub _timeout {
428 my ($self) = @_;
429
430 if ($self->{timeout}) {
431 my $NOW = AnyEvent->now;
432
433 # when would the timeout trigger?
434 my $after = $self->{_activity} + $self->{timeout} - $NOW;
435
436 # now or in the past already?
437 if ($after <= 0) {
438 $self->{_activity} = $NOW;
439
440 if ($self->{on_timeout}) {
441 $self->{on_timeout}($self);
442 } else {
443 $self->_error (&Errno::ETIMEDOUT);
444 }
445
446 # callback could have changed timeout value, optimise
447 return unless $self->{timeout};
448
449 # calculate new after
450 $after = $self->{timeout};
451 }
452
453 Scalar::Util::weaken $self;
454 return unless $self; # ->error could have destroyed $self
455
456 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
457 delete $self->{_tw};
458 $self->_timeout;
459 });
460 } else {
461 delete $self->{_tw};
462 }
463}
464
267############################################################################# 465#############################################################################
268 466
269=back 467=back
270 468
271=head2 WRITE QUEUE 469=head2 WRITE QUEUE
292 my ($self, $cb) = @_; 490 my ($self, $cb) = @_;
293 491
294 $self->{on_drain} = $cb; 492 $self->{on_drain} = $cb;
295 493
296 $cb->($self) 494 $cb->($self)
297 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 495 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
298} 496}
299 497
300=item $handle->push_write ($data) 498=item $handle->push_write ($data)
301 499
302Queues the given scalar to be written. You can push as much data as you 500Queues the given scalar to be written. You can push as much data as you
316 my $len = syswrite $self->{fh}, $self->{wbuf}; 514 my $len = syswrite $self->{fh}, $self->{wbuf};
317 515
318 if ($len >= 0) { 516 if ($len >= 0) {
319 substr $self->{wbuf}, 0, $len, ""; 517 substr $self->{wbuf}, 0, $len, "";
320 518
519 $self->{_activity} = AnyEvent->now;
520
321 $self->{on_drain}($self) 521 $self->{on_drain}($self)
322 if $self->{low_water_mark} >= length $self->{wbuf} 522 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
323 && $self->{on_drain}; 523 && $self->{on_drain};
324 524
325 delete $self->{_ww} unless length $self->{wbuf}; 525 delete $self->{_ww} unless length $self->{wbuf};
326 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAWOULDBLOCK) { 526 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
327 $self->error; 527 $self->_error ($!, 1);
328 } 528 }
329 }; 529 };
330 530
331 # try to write data immediately 531 # try to write data immediately
332 $cb->(); 532 $cb->() unless $self->{autocork};
333 533
334 # if still data left in wbuf, we need to poll 534 # if still data left in wbuf, we need to poll
335 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 535 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
336 if length $self->{wbuf}; 536 if length $self->{wbuf};
337 }; 537 };
351 551
352 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 552 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
353 ->($self, @_); 553 ->($self, @_);
354 } 554 }
355 555
356 if ($self->{filter_w}) { 556 if ($self->{tls}) {
357 $self->{filter_w}->($self, \$_[0]); 557 $self->{_tls_wbuf} .= $_[0];
558
559 &_dotls ($self);
358 } else { 560 } else {
359 $self->{wbuf} .= $_[0]; 561 $self->{wbuf} .= $_[0];
360 $self->_drain_wbuf; 562 $self->_drain_wbuf;
361 } 563 }
362} 564}
363 565
364=item $handle->push_write (type => @args) 566=item $handle->push_write (type => @args)
365 567
366=item $handle->unshift_write (type => @args)
367
368Instead of formatting your data yourself, you can also let this module do 568Instead of formatting your data yourself, you can also let this module do
369the job by specifying a type and type-specific arguments. 569the job by specifying a type and type-specific arguments.
370 570
371Predefined types are (if you have ideas for additional types, feel free to 571Predefined types are (if you have ideas for additional types, feel free to
372drop by and tell us): 572drop by and tell us):
376=item netstring => $string 576=item netstring => $string
377 577
378Formats the given value as netstring 578Formats the given value as netstring
379(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 579(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
380 580
381=back
382
383=cut 581=cut
384 582
385register_write_type netstring => sub { 583register_write_type netstring => sub {
386 my ($self, $string) = @_; 584 my ($self, $string) = @_;
387 585
388 sprintf "%d:%s,", (length $string), $string 586 (length $string) . ":$string,"
587};
588
589=item packstring => $format, $data
590
591An octet string prefixed with an encoded length. The encoding C<$format>
592uses the same format as a Perl C<pack> format, but must specify a single
593integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
594optional C<!>, C<< < >> or C<< > >> modifier).
595
596=cut
597
598register_write_type packstring => sub {
599 my ($self, $format, $string) = @_;
600
601 pack "$format/a*", $string
389}; 602};
390 603
391=item json => $array_or_hashref 604=item json => $array_or_hashref
392 605
393Encodes the given hash or array reference into a JSON object. Unless you 606Encodes the given hash or array reference into a JSON object. Unless you
396 609
397JSON objects (and arrays) are self-delimiting, so you can write JSON at 610JSON objects (and arrays) are self-delimiting, so you can write JSON at
398one end of a handle and read them at the other end without using any 611one end of a handle and read them at the other end without using any
399additional framing. 612additional framing.
400 613
614The generated JSON text is guaranteed not to contain any newlines: While
615this module doesn't need delimiters after or between JSON texts to be
616able to read them, many other languages depend on that.
617
618A simple RPC protocol that interoperates easily with others is to send
619JSON arrays (or objects, although arrays are usually the better choice as
620they mimic how function argument passing works) and a newline after each
621JSON text:
622
623 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
624 $handle->push_write ("\012");
625
626An AnyEvent::Handle receiver would simply use the C<json> read type and
627rely on the fact that the newline will be skipped as leading whitespace:
628
629 $handle->push_read (json => sub { my $array = $_[1]; ... });
630
631Other languages could read single lines terminated by a newline and pass
632this line into their JSON decoder of choice.
633
401=cut 634=cut
402 635
403register_write_type json => sub { 636register_write_type json => sub {
404 my ($self, $ref) = @_; 637 my ($self, $ref) = @_;
405 638
407 640
408 $self->{json} ? $self->{json}->encode ($ref) 641 $self->{json} ? $self->{json}->encode ($ref)
409 : JSON::encode_json ($ref) 642 : JSON::encode_json ($ref)
410}; 643};
411 644
645=item storable => $reference
646
647Freezes the given reference using L<Storable> and writes it to the
648handle. Uses the C<nfreeze> format.
649
650=cut
651
652register_write_type storable => sub {
653 my ($self, $ref) = @_;
654
655 require Storable;
656
657 pack "w/a*", Storable::nfreeze ($ref)
658};
659
660=back
661
412=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 662=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
413 663
414This function (not method) lets you add your own types to C<push_write>. 664This function (not method) lets you add your own types to C<push_write>.
415Whenever the given C<type> is used, C<push_write> will invoke the code 665Whenever the given C<type> is used, C<push_write> will invoke the code
416reference with the handle object and the remaining arguments. 666reference with the handle object and the remaining arguments.
436ways, the "simple" way, using only C<on_read> and the "complex" way, using 686ways, the "simple" way, using only C<on_read> and the "complex" way, using
437a queue. 687a queue.
438 688
439In the simple case, you just install an C<on_read> callback and whenever 689In the simple case, you just install an C<on_read> callback and whenever
440new data arrives, it will be called. You can then remove some data (if 690new data arrives, it will be called. You can then remove some data (if
441enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 691enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
442or not. 692leave the data there if you want to accumulate more (e.g. when only a
693partial message has been received so far).
443 694
444In the more complex case, you want to queue multiple callbacks. In this 695In the more complex case, you want to queue multiple callbacks. In this
445case, AnyEvent::Handle will call the first queued callback each time new 696case, AnyEvent::Handle will call the first queued callback each time new
446data arrives and removes it when it has done its job (see C<push_read>, 697data arrives (also the first time it is queued) and removes it when it has
447below). 698done its job (see C<push_read>, below).
448 699
449This way you can, for example, push three line-reads, followed by reading 700This way you can, for example, push three line-reads, followed by reading
450a chunk of data, and AnyEvent::Handle will execute them in order. 701a chunk of data, and AnyEvent::Handle will execute them in order.
451 702
452Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 703Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
453the specified number of bytes which give an XML datagram. 704the specified number of bytes which give an XML datagram.
454 705
455 # in the default state, expect some header bytes 706 # in the default state, expect some header bytes
456 $handle->on_read (sub { 707 $handle->on_read (sub {
457 # some data is here, now queue the length-header-read (4 octets) 708 # some data is here, now queue the length-header-read (4 octets)
458 shift->unshift_read_chunk (4, sub { 709 shift->unshift_read (chunk => 4, sub {
459 # header arrived, decode 710 # header arrived, decode
460 my $len = unpack "N", $_[1]; 711 my $len = unpack "N", $_[1];
461 712
462 # now read the payload 713 # now read the payload
463 shift->unshift_read_chunk ($len, sub { 714 shift->unshift_read (chunk => $len, sub {
464 my $xml = $_[1]; 715 my $xml = $_[1];
465 # handle xml 716 # handle xml
466 }); 717 });
467 }); 718 });
468 }); 719 });
469 720
470Example 2: Implement a client for a protocol that replies either with 721Example 2: Implement a client for a protocol that replies either with "OK"
471"OK" and another line or "ERROR" for one request, and 64 bytes for the 722and another line or "ERROR" for the first request that is sent, and 64
472second request. Due tot he availability of a full queue, we can just 723bytes for the second request. Due to the availability of a queue, we can
473pipeline sending both requests and manipulate the queue as necessary in 724just pipeline sending both requests and manipulate the queue as necessary
474the callbacks: 725in the callbacks.
475 726
476 # request one 727When the first callback is called and sees an "OK" response, it will
728C<unshift> another line-read. This line-read will be queued I<before> the
72964-byte chunk callback.
730
731 # request one, returns either "OK + extra line" or "ERROR"
477 $handle->push_write ("request 1\015\012"); 732 $handle->push_write ("request 1\015\012");
478 733
479 # we expect "ERROR" or "OK" as response, so push a line read 734 # we expect "ERROR" or "OK" as response, so push a line read
480 $handle->push_read_line (sub { 735 $handle->push_read (line => sub {
481 # if we got an "OK", we have to _prepend_ another line, 736 # if we got an "OK", we have to _prepend_ another line,
482 # so it will be read before the second request reads its 64 bytes 737 # so it will be read before the second request reads its 64 bytes
483 # which are already in the queue when this callback is called 738 # which are already in the queue when this callback is called
484 # we don't do this in case we got an error 739 # we don't do this in case we got an error
485 if ($_[1] eq "OK") { 740 if ($_[1] eq "OK") {
486 $_[0]->unshift_read_line (sub { 741 $_[0]->unshift_read (line => sub {
487 my $response = $_[1]; 742 my $response = $_[1];
488 ... 743 ...
489 }); 744 });
490 } 745 }
491 }); 746 });
492 747
493 # request two 748 # request two, simply returns 64 octets
494 $handle->push_write ("request 2\015\012"); 749 $handle->push_write ("request 2\015\012");
495 750
496 # simply read 64 bytes, always 751 # simply read 64 bytes, always
497 $handle->push_read_chunk (64, sub { 752 $handle->push_read (chunk => 64, sub {
498 my $response = $_[1]; 753 my $response = $_[1];
499 ... 754 ...
500 }); 755 });
501 756
502=over 4 757=over 4
503 758
504=cut 759=cut
505 760
506sub _drain_rbuf { 761sub _drain_rbuf {
507 my ($self) = @_; 762 my ($self) = @_;
763
764 local $self->{_in_drain} = 1;
508 765
509 if ( 766 if (
510 defined $self->{rbuf_max} 767 defined $self->{rbuf_max}
511 && $self->{rbuf_max} < length $self->{rbuf} 768 && $self->{rbuf_max} < length $self->{rbuf}
512 ) { 769 ) {
513 $! = &Errno::ENOSPC; 770 $self->_error (&Errno::ENOSPC, 1), return;
514 $self->error;
515 } 771 }
516 772
517 return if $self->{in_drain}; 773 while () {
518 local $self->{in_drain} = 1; 774 # we need to use a separate tls read buffer, as we must not receive data while
775 # we are draining the buffer, and this can only happen with TLS.
776 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
519 777
520 while (my $len = length $self->{rbuf}) { 778 my $len = length $self->{rbuf};
521 no strict 'refs'; 779
522 if (my $cb = shift @{ $self->{_queue} }) { 780 if (my $cb = shift @{ $self->{_queue} }) {
523 unless ($cb->($self)) { 781 unless ($cb->($self)) {
524 if ($self->{_eof}) { 782 if ($self->{_eof}) {
525 # no progress can be made (not enough data and no data forthcoming) 783 # no progress can be made (not enough data and no data forthcoming)
526 $! = &Errno::EPIPE; 784 $self->_error (&Errno::EPIPE, 1), return;
527 $self->error;
528 } 785 }
529 786
530 unshift @{ $self->{_queue} }, $cb; 787 unshift @{ $self->{_queue} }, $cb;
531 return; 788 last;
532 } 789 }
533 } elsif ($self->{on_read}) { 790 } elsif ($self->{on_read}) {
791 last unless $len;
792
534 $self->{on_read}($self); 793 $self->{on_read}($self);
535 794
536 if ( 795 if (
537 $self->{_eof} # if no further data will arrive
538 && $len == length $self->{rbuf} # and no data has been consumed 796 $len == length $self->{rbuf} # if no data has been consumed
539 && !@{ $self->{_queue} } # and the queue is still empty 797 && !@{ $self->{_queue} } # and the queue is still empty
540 && $self->{on_read} # and we still want to read data 798 && $self->{on_read} # but we still have on_read
541 ) { 799 ) {
800 # no further data will arrive
542 # then no progress can be made 801 # so no progress can be made
543 $! = &Errno::EPIPE; 802 $self->_error (&Errno::EPIPE, 1), return
544 $self->error; 803 if $self->{_eof};
804
805 last; # more data might arrive
545 } 806 }
546 } else { 807 } else {
547 # read side becomes idle 808 # read side becomes idle
548 delete $self->{_rw}; 809 delete $self->{_rw} unless $self->{tls};
549 return; 810 last;
550 } 811 }
551 } 812 }
552 813
553 if ($self->{_eof}) { 814 if ($self->{_eof}) {
554 $self->_shutdown; 815 if ($self->{on_eof}) {
555 $self->{on_eof}($self) 816 $self->{on_eof}($self)
556 if $self->{on_eof}; 817 } else {
818 $self->_error (0, 1);
819 }
820 }
821
822 # may need to restart read watcher
823 unless ($self->{_rw}) {
824 $self->start_read
825 if $self->{on_read} || @{ $self->{_queue} };
557 } 826 }
558} 827}
559 828
560=item $handle->on_read ($cb) 829=item $handle->on_read ($cb)
561 830
567 836
568sub on_read { 837sub on_read {
569 my ($self, $cb) = @_; 838 my ($self, $cb) = @_;
570 839
571 $self->{on_read} = $cb; 840 $self->{on_read} = $cb;
841 $self->_drain_rbuf if $cb && !$self->{_in_drain};
572} 842}
573 843
574=item $handle->rbuf 844=item $handle->rbuf
575 845
576Returns the read buffer (as a modifiable lvalue). 846Returns the read buffer (as a modifiable lvalue).
577 847
578You can access the read buffer directly as the C<< ->{rbuf} >> member, if 848You can access the read buffer directly as the C<< ->{rbuf} >>
579you want. 849member, if you want. However, the only operation allowed on the
850read buffer (apart from looking at it) is removing data from its
851beginning. Otherwise modifying or appending to it is not allowed and will
852lead to hard-to-track-down bugs.
580 853
581NOTE: The read buffer should only be used or modified if the C<on_read>, 854NOTE: The read buffer should only be used or modified if the C<on_read>,
582C<push_read> or C<unshift_read> methods are used. The other read methods 855C<push_read> or C<unshift_read> methods are used. The other read methods
583automatically manage the read buffer. 856automatically manage the read buffer.
584 857
625 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 898 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
626 ->($self, $cb, @_); 899 ->($self, $cb, @_);
627 } 900 }
628 901
629 push @{ $self->{_queue} }, $cb; 902 push @{ $self->{_queue} }, $cb;
630 $self->_drain_rbuf; 903 $self->_drain_rbuf unless $self->{_in_drain};
631} 904}
632 905
633sub unshift_read { 906sub unshift_read {
634 my $self = shift; 907 my $self = shift;
635 my $cb = pop; 908 my $cb = pop;
641 ->($self, $cb, @_); 914 ->($self, $cb, @_);
642 } 915 }
643 916
644 917
645 unshift @{ $self->{_queue} }, $cb; 918 unshift @{ $self->{_queue} }, $cb;
646 $self->_drain_rbuf; 919 $self->_drain_rbuf unless $self->{_in_drain};
647} 920}
648 921
649=item $handle->push_read (type => @args, $cb) 922=item $handle->push_read (type => @args, $cb)
650 923
651=item $handle->unshift_read (type => @args, $cb) 924=item $handle->unshift_read (type => @args, $cb)
681 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 954 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
682 1 955 1
683 } 956 }
684}; 957};
685 958
686# compatibility with older API
687sub push_read_chunk {
688 $_[0]->push_read (chunk => $_[1], $_[2]);
689}
690
691sub unshift_read_chunk {
692 $_[0]->unshift_read (chunk => $_[1], $_[2]);
693}
694
695=item line => [$eol, ]$cb->($handle, $line, $eol) 959=item line => [$eol, ]$cb->($handle, $line, $eol)
696 960
697The callback will be called only once a full line (including the end of 961The callback will be called only once a full line (including the end of
698line marker, C<$eol>) has been read. This line (excluding the end of line 962line marker, C<$eol>) has been read. This line (excluding the end of line
699marker) will be passed to the callback as second argument (C<$line>), and 963marker) will be passed to the callback as second argument (C<$line>), and
714=cut 978=cut
715 979
716register_read_type line => sub { 980register_read_type line => sub {
717 my ($self, $cb, $eol) = @_; 981 my ($self, $cb, $eol) = @_;
718 982
719 $eol = qr|(\015?\012)| if @_ < 3; 983 if (@_ < 3) {
720 $eol = quotemeta $eol unless ref $eol; 984 # this is more than twice as fast as the generic code below
721 $eol = qr|^(.*?)($eol)|s;
722
723 sub { 985 sub {
724 $_[0]{rbuf} =~ s/$eol// or return; 986 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
725 987
726 $cb->($_[0], $1, $2); 988 $cb->($_[0], $1, $2);
727 1
728 }
729};
730
731# compatibility with older API
732sub push_read_line {
733 my $self = shift;
734 $self->push_read (line => @_);
735}
736
737sub unshift_read_line {
738 my $self = shift;
739 $self->unshift_read (line => @_);
740}
741
742=item netstring => $cb->($handle, $string)
743
744A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
745
746Throws an error with C<$!> set to EBADMSG on format violations.
747
748=cut
749
750register_read_type netstring => sub {
751 my ($self, $cb) = @_;
752
753 sub {
754 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
755 if ($_[0]{rbuf} =~ /[^0-9]/) {
756 $! = &Errno::EBADMSG;
757 $self->error;
758 } 989 1
759 return;
760 } 990 }
991 } else {
992 $eol = quotemeta $eol unless ref $eol;
993 $eol = qr|^(.*?)($eol)|s;
761 994
762 my $len = $1; 995 sub {
996 $_[0]{rbuf} =~ s/$eol// or return;
763 997
764 $self->unshift_read (chunk => $len, sub { 998 $cb->($_[0], $1, $2);
765 my $string = $_[1];
766 $_[0]->unshift_read (chunk => 1, sub {
767 if ($_[1] eq ",") {
768 $cb->($_[0], $string);
769 } else {
770 $! = &Errno::EBADMSG;
771 $self->error;
772 }
773 }); 999 1
774 }); 1000 }
775
776 1
777 } 1001 }
778}; 1002};
779 1003
780=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1004=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
781 1005
833 return 1; 1057 return 1;
834 } 1058 }
835 1059
836 # reject 1060 # reject
837 if ($reject && $$rbuf =~ $reject) { 1061 if ($reject && $$rbuf =~ $reject) {
838 $! = &Errno::EBADMSG; 1062 $self->_error (&Errno::EBADMSG);
839 $self->error;
840 } 1063 }
841 1064
842 # skip 1065 # skip
843 if ($skip && $$rbuf =~ $skip) { 1066 if ($skip && $$rbuf =~ $skip) {
844 $data .= substr $$rbuf, 0, $+[0], ""; 1067 $data .= substr $$rbuf, 0, $+[0], "";
846 1069
847 () 1070 ()
848 } 1071 }
849}; 1072};
850 1073
1074=item netstring => $cb->($handle, $string)
1075
1076A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1077
1078Throws an error with C<$!> set to EBADMSG on format violations.
1079
1080=cut
1081
1082register_read_type netstring => sub {
1083 my ($self, $cb) = @_;
1084
1085 sub {
1086 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1087 if ($_[0]{rbuf} =~ /[^0-9]/) {
1088 $self->_error (&Errno::EBADMSG);
1089 }
1090 return;
1091 }
1092
1093 my $len = $1;
1094
1095 $self->unshift_read (chunk => $len, sub {
1096 my $string = $_[1];
1097 $_[0]->unshift_read (chunk => 1, sub {
1098 if ($_[1] eq ",") {
1099 $cb->($_[0], $string);
1100 } else {
1101 $self->_error (&Errno::EBADMSG);
1102 }
1103 });
1104 });
1105
1106 1
1107 }
1108};
1109
1110=item packstring => $format, $cb->($handle, $string)
1111
1112An octet string prefixed with an encoded length. The encoding C<$format>
1113uses the same format as a Perl C<pack> format, but must specify a single
1114integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1115optional C<!>, C<< < >> or C<< > >> modifier).
1116
1117For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1118EPP uses a prefix of C<N> (4 octtes).
1119
1120Example: read a block of data prefixed by its length in BER-encoded
1121format (very efficient).
1122
1123 $handle->push_read (packstring => "w", sub {
1124 my ($handle, $data) = @_;
1125 });
1126
1127=cut
1128
1129register_read_type packstring => sub {
1130 my ($self, $cb, $format) = @_;
1131
1132 sub {
1133 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1134 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1135 or return;
1136
1137 $format = length pack $format, $len;
1138
1139 # bypass unshift if we already have the remaining chunk
1140 if ($format + $len <= length $_[0]{rbuf}) {
1141 my $data = substr $_[0]{rbuf}, $format, $len;
1142 substr $_[0]{rbuf}, 0, $format + $len, "";
1143 $cb->($_[0], $data);
1144 } else {
1145 # remove prefix
1146 substr $_[0]{rbuf}, 0, $format, "";
1147
1148 # read remaining chunk
1149 $_[0]->unshift_read (chunk => $len, $cb);
1150 }
1151
1152 1
1153 }
1154};
1155
851=item json => $cb->($handle, $hash_or_arrayref) 1156=item json => $cb->($handle, $hash_or_arrayref)
852 1157
853Reads a JSON object or array, decodes it and passes it to the callback. 1158Reads a JSON object or array, decodes it and passes it to the
1159callback. When a parse error occurs, an C<EBADMSG> error will be raised.
854 1160
855If a C<json> object was passed to the constructor, then that will be used 1161If a C<json> object was passed to the constructor, then that will be used
856for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1162for the final decode, otherwise it will create a JSON coder expecting UTF-8.
857 1163
858This read type uses the incremental parser available with JSON version 1164This read type uses the incremental parser available with JSON version
8592.09 (and JSON::XS version 2.2) and above. You have to provide a 11652.09 (and JSON::XS version 2.2) and above. You have to provide a
860dependency on your own: this module will load the JSON module, but 1166dependency on your own: this module will load the JSON module, but
861AnyEvent does not depend on it itself. 1167AnyEvent does not depend on it itself.
862 1168
863Since JSON texts are fully self-delimiting, the C<json> read and write 1169Since JSON texts are fully self-delimiting, the C<json> read and write
864types are an ideal simple RPC protocol: just exchange JSON datagrams. 1170types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1171the C<json> write type description, above, for an actual example.
865 1172
866=cut 1173=cut
867 1174
868register_read_type json => sub { 1175register_read_type json => sub {
869 my ($self, $cb, $accept, $reject, $skip) = @_; 1176 my ($self, $cb) = @_;
870 1177
871 require JSON; 1178 require JSON;
872 1179
873 my $data; 1180 my $data;
874 my $rbuf = \$self->{rbuf}; 1181 my $rbuf = \$self->{rbuf};
875 1182
876 my $json = $self->{json} ||= JSON::XS->new->utf8; 1183 my $json = $self->{json} ||= JSON->new->utf8;
877 1184
878 sub { 1185 sub {
879 my $ref = $json->incr_parse ($self->{rbuf}); 1186 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
880 1187
881 if ($ref) { 1188 if ($ref) {
882 $self->{rbuf} = $json->incr_text; 1189 $self->{rbuf} = $json->incr_text;
883 $json->incr_text = ""; 1190 $json->incr_text = "";
884 $cb->($self, $ref); 1191 $cb->($self, $ref);
885 1192
886 1 1193 1
1194 } elsif ($@) {
1195 # error case
1196 $json->incr_skip;
1197
1198 $self->{rbuf} = $json->incr_text;
1199 $json->incr_text = "";
1200
1201 $self->_error (&Errno::EBADMSG);
1202
1203 ()
887 } else { 1204 } else {
888 $self->{rbuf} = ""; 1205 $self->{rbuf} = "";
1206
889 () 1207 ()
890 } 1208 }
1209 }
1210};
1211
1212=item storable => $cb->($handle, $ref)
1213
1214Deserialises a L<Storable> frozen representation as written by the
1215C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1216data).
1217
1218Raises C<EBADMSG> error if the data could not be decoded.
1219
1220=cut
1221
1222register_read_type storable => sub {
1223 my ($self, $cb) = @_;
1224
1225 require Storable;
1226
1227 sub {
1228 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1229 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1230 or return;
1231
1232 my $format = length pack "w", $len;
1233
1234 # bypass unshift if we already have the remaining chunk
1235 if ($format + $len <= length $_[0]{rbuf}) {
1236 my $data = substr $_[0]{rbuf}, $format, $len;
1237 substr $_[0]{rbuf}, 0, $format + $len, "";
1238 $cb->($_[0], Storable::thaw ($data));
1239 } else {
1240 # remove prefix
1241 substr $_[0]{rbuf}, 0, $format, "";
1242
1243 # read remaining chunk
1244 $_[0]->unshift_read (chunk => $len, sub {
1245 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1246 $cb->($_[0], $ref);
1247 } else {
1248 $self->_error (&Errno::EBADMSG);
1249 }
1250 });
1251 }
1252
1253 1
891 } 1254 }
892}; 1255};
893 1256
894=back 1257=back
895 1258
916=item $handle->stop_read 1279=item $handle->stop_read
917 1280
918=item $handle->start_read 1281=item $handle->start_read
919 1282
920In rare cases you actually do not want to read anything from the 1283In rare cases you actually do not want to read anything from the
921socket. In this case you can call C<stop_read>. Neither C<on_read> no 1284socket. In this case you can call C<stop_read>. Neither C<on_read> nor
922any queued callbacks will be executed then. To start reading again, call 1285any queued callbacks will be executed then. To start reading again, call
923C<start_read>. 1286C<start_read>.
924 1287
1288Note that AnyEvent::Handle will automatically C<start_read> for you when
1289you change the C<on_read> callback or push/unshift a read callback, and it
1290will automatically C<stop_read> for you when neither C<on_read> is set nor
1291there are any read requests in the queue.
1292
1293These methods will have no effect when in TLS mode (as TLS doesn't support
1294half-duplex connections).
1295
925=cut 1296=cut
926 1297
927sub stop_read { 1298sub stop_read {
928 my ($self) = @_; 1299 my ($self) = @_;
929 1300
930 delete $self->{_rw}; 1301 delete $self->{_rw} unless $self->{tls};
931} 1302}
932 1303
933sub start_read { 1304sub start_read {
934 my ($self) = @_; 1305 my ($self) = @_;
935 1306
936 unless ($self->{_rw} || $self->{_eof}) { 1307 unless ($self->{_rw} || $self->{_eof}) {
937 Scalar::Util::weaken $self; 1308 Scalar::Util::weaken $self;
938 1309
939 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1310 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
940 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1311 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
941 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1312 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
942 1313
943 if ($len > 0) { 1314 if ($len > 0) {
944 $self->{filter_r} 1315 $self->{_activity} = AnyEvent->now;
945 ? $self->{filter_r}->($self, $rbuf) 1316
946 : $self->_drain_rbuf; 1317 if ($self->{tls}) {
1318 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1319
1320 &_dotls ($self);
1321 } else {
1322 $self->_drain_rbuf unless $self->{_in_drain};
1323 }
947 1324
948 } elsif (defined $len) { 1325 } elsif (defined $len) {
949 delete $self->{_rw}; 1326 delete $self->{_rw};
950 $self->{_eof} = 1; 1327 $self->{_eof} = 1;
951 $self->_drain_rbuf; 1328 $self->_drain_rbuf unless $self->{_in_drain};
952 1329
953 } elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAWOULDBLOCK) { 1330 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
954 return $self->error; 1331 return $self->_error ($!, 1);
955 } 1332 }
956 }); 1333 });
957 } 1334 }
958} 1335}
959 1336
1337# poll the write BIO and send the data if applicable
960sub _dotls { 1338sub _dotls {
961 my ($self) = @_; 1339 my ($self) = @_;
962 1340
1341 my $tmp;
1342
963 if (length $self->{_tls_wbuf}) { 1343 if (length $self->{_tls_wbuf}) {
964 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1344 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
965 substr $self->{_tls_wbuf}, 0, $len, ""; 1345 substr $self->{_tls_wbuf}, 0, $tmp, "";
966 } 1346 }
967 } 1347 }
968 1348
1349 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1350 unless (length $tmp) {
1351 # let's treat SSL-eof as we treat normal EOF
1352 delete $self->{_rw};
1353 $self->{_eof} = 1;
1354 &_freetls;
1355 }
1356
1357 $self->{_tls_rbuf} .= $tmp;
1358 $self->_drain_rbuf unless $self->{_in_drain};
1359 $self->{tls} or return; # tls session might have gone away in callback
1360 }
1361
1362 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1363
1364 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1365 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1366 return $self->_error ($!, 1);
1367 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1368 return $self->_error (&Errno::EIO, 1);
1369 }
1370
1371 # all other errors are fine for our purposes
1372 }
1373
969 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 1374 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
970 $self->{wbuf} .= $buf; 1375 $self->{wbuf} .= $tmp;
971 $self->_drain_wbuf; 1376 $self->_drain_wbuf;
972 }
973
974 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
975 $self->{rbuf} .= $buf;
976 $self->_drain_rbuf;
977 }
978
979 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
980
981 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
982 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
983 $self->error;
984 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
985 $! = &Errno::EIO;
986 $self->error;
987 }
988
989 # all others are fine for our purposes
990 } 1377 }
991} 1378}
992 1379
993=item $handle->starttls ($tls[, $tls_ctx]) 1380=item $handle->starttls ($tls[, $tls_ctx])
994 1381
1004 1391
1005The TLS connection object will end up in C<< $handle->{tls} >> after this 1392The TLS connection object will end up in C<< $handle->{tls} >> after this
1006call and can be used or changed to your liking. Note that the handshake 1393call and can be used or changed to your liking. Note that the handshake
1007might have already started when this function returns. 1394might have already started when this function returns.
1008 1395
1009=cut 1396If it an error to start a TLS handshake more than once per
1397AnyEvent::Handle object (this is due to bugs in OpenSSL).
1010 1398
1011# TODO: maybe document... 1399=cut
1400
1012sub starttls { 1401sub starttls {
1013 my ($self, $ssl, $ctx) = @_; 1402 my ($self, $ssl, $ctx) = @_;
1014 1403
1015 $self->stoptls; 1404 require Net::SSLeay;
1016 1405
1406 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1407 if $self->{tls};
1408
1017 if ($ssl eq "accept") { 1409 if ($ssl eq "accept") {
1018 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1410 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1019 Net::SSLeay::set_accept_state ($ssl); 1411 Net::SSLeay::set_accept_state ($ssl);
1020 } elsif ($ssl eq "connect") { 1412 } elsif ($ssl eq "connect") {
1021 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1413 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1027 # basically, this is deep magic (because SSL_read should have the same issues) 1419 # basically, this is deep magic (because SSL_read should have the same issues)
1028 # but the openssl maintainers basically said: "trust us, it just works". 1420 # but the openssl maintainers basically said: "trust us, it just works".
1029 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1421 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1030 # and mismaintained ssleay-module doesn't even offer them). 1422 # and mismaintained ssleay-module doesn't even offer them).
1031 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1423 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1424 #
1425 # in short: this is a mess.
1426 #
1427 # note that we do not try to keep the length constant between writes as we are required to do.
1428 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1429 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1430 # have identity issues in that area.
1032 Net::SSLeay::CTX_set_mode ($self->{tls}, 1431 Net::SSLeay::CTX_set_mode ($self->{tls},
1033 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1432 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1034 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1433 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1035 1434
1036 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1435 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1037 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1436 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1038 1437
1039 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1438 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1040 1439
1041 $self->{filter_w} = sub { 1440 &_dotls; # need to trigger the initial handshake
1042 $_[0]{_tls_wbuf} .= ${$_[1]}; 1441 $self->start_read; # make sure we actually do read
1043 &_dotls;
1044 };
1045 $self->{filter_r} = sub {
1046 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1047 &_dotls;
1048 };
1049} 1442}
1050 1443
1051=item $handle->stoptls 1444=item $handle->stoptls
1052 1445
1053Destroys the SSL connection, if any. Partial read or write data will be 1446Shuts down the SSL connection - this makes a proper EOF handshake by
1054lost. 1447sending a close notify to the other side, but since OpenSSL doesn't
1448support non-blocking shut downs, it is not possible to re-use the stream
1449afterwards.
1055 1450
1056=cut 1451=cut
1057 1452
1058sub stoptls { 1453sub stoptls {
1059 my ($self) = @_; 1454 my ($self) = @_;
1060 1455
1456 if ($self->{tls}) {
1457 Net::SSLeay::shutdown ($self->{tls});
1458
1459 &_dotls;
1460
1461 # we don't give a shit. no, we do, but we can't. no...
1462 # we, we... have to use openssl :/
1463 &_freetls;
1464 }
1465}
1466
1467sub _freetls {
1468 my ($self) = @_;
1469
1470 return unless $self->{tls};
1471
1061 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1472 Net::SSLeay::free (delete $self->{tls});
1062 1473
1063 delete $self->{_rbio}; 1474 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1064 delete $self->{_wbio};
1065 delete $self->{_tls_wbuf};
1066 delete $self->{filter_r};
1067 delete $self->{filter_w};
1068} 1475}
1069 1476
1070sub DESTROY { 1477sub DESTROY {
1071 my $self = shift; 1478 my ($self) = @_;
1072 1479
1073 $self->stoptls; 1480 &_freetls;
1481
1482 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1483
1484 if ($linger && length $self->{wbuf}) {
1485 my $fh = delete $self->{fh};
1486 my $wbuf = delete $self->{wbuf};
1487
1488 my @linger;
1489
1490 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1491 my $len = syswrite $fh, $wbuf, length $wbuf;
1492
1493 if ($len > 0) {
1494 substr $wbuf, 0, $len, "";
1495 } else {
1496 @linger = (); # end
1497 }
1498 });
1499 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1500 @linger = ();
1501 });
1502 }
1503}
1504
1505=item $handle->destroy
1506
1507Shuts down the handle object as much as possible - this call ensures that
1508no further callbacks will be invoked and resources will be freed as much
1509as possible. You must not call any methods on the object afterwards.
1510
1511Normally, you can just "forget" any references to an AnyEvent::Handle
1512object and it will simply shut down. This works in fatal error and EOF
1513callbacks, as well as code outside. It does I<NOT> work in a read or write
1514callback, so when you want to destroy the AnyEvent::Handle object from
1515within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1516that case.
1517
1518The handle might still linger in the background and write out remaining
1519data, as specified by the C<linger> option, however.
1520
1521=cut
1522
1523sub destroy {
1524 my ($self) = @_;
1525
1526 $self->DESTROY;
1527 %$self = ();
1074} 1528}
1075 1529
1076=item AnyEvent::Handle::TLS_CTX 1530=item AnyEvent::Handle::TLS_CTX
1077 1531
1078This function creates and returns the Net::SSLeay::CTX object used by 1532This function creates and returns the Net::SSLeay::CTX object used by
1108 } 1562 }
1109} 1563}
1110 1564
1111=back 1565=back
1112 1566
1567
1568=head1 NONFREQUENTLY ASKED QUESTIONS
1569
1570=over 4
1571
1572=item I C<undef> the AnyEvent::Handle reference inside my callback and
1573still get further invocations!
1574
1575That's because AnyEvent::Handle keeps a reference to itself when handling
1576read or write callbacks.
1577
1578It is only safe to "forget" the reference inside EOF or error callbacks,
1579from within all other callbacks, you need to explicitly call the C<<
1580->destroy >> method.
1581
1582=item I get different callback invocations in TLS mode/Why can't I pause
1583reading?
1584
1585Unlike, say, TCP, TLS connections do not consist of two independent
1586communication channels, one for each direction. Or put differently. The
1587read and write directions are not independent of each other: you cannot
1588write data unless you are also prepared to read, and vice versa.
1589
1590This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1591callback invocations when you are not expecting any read data - the reason
1592is that AnyEvent::Handle always reads in TLS mode.
1593
1594During the connection, you have to make sure that you always have a
1595non-empty read-queue, or an C<on_read> watcher. At the end of the
1596connection (or when you no longer want to use it) you can call the
1597C<destroy> method.
1598
1599=item How do I read data until the other side closes the connection?
1600
1601If you just want to read your data into a perl scalar, the easiest way
1602to achieve this is by setting an C<on_read> callback that does nothing,
1603clearing the C<on_eof> callback and in the C<on_error> callback, the data
1604will be in C<$_[0]{rbuf}>:
1605
1606 $handle->on_read (sub { });
1607 $handle->on_eof (undef);
1608 $handle->on_error (sub {
1609 my $data = delete $_[0]{rbuf};
1610 undef $handle;
1611 });
1612
1613The reason to use C<on_error> is that TCP connections, due to latencies
1614and packets loss, might get closed quite violently with an error, when in
1615fact, all data has been received.
1616
1617It is usually better to use acknowledgements when transferring data,
1618to make sure the other side hasn't just died and you got the data
1619intact. This is also one reason why so many internet protocols have an
1620explicit QUIT command.
1621
1622=item I don't want to destroy the handle too early - how do I wait until
1623all data has been written?
1624
1625After writing your last bits of data, set the C<on_drain> callback
1626and destroy the handle in there - with the default setting of
1627C<low_water_mark> this will be called precisely when all data has been
1628written to the socket:
1629
1630 $handle->push_write (...);
1631 $handle->on_drain (sub {
1632 warn "all data submitted to the kernel\n";
1633 undef $handle;
1634 });
1635
1636=back
1637
1638
1113=head1 SUBCLASSING AnyEvent::Handle 1639=head1 SUBCLASSING AnyEvent::Handle
1114 1640
1115In many cases, you might want to subclass AnyEvent::Handle. 1641In many cases, you might want to subclass AnyEvent::Handle.
1116 1642
1117To make this easier, a given version of AnyEvent::Handle uses these 1643To make this easier, a given version of AnyEvent::Handle uses these
1120=over 4 1646=over 4
1121 1647
1122=item * all constructor arguments become object members. 1648=item * all constructor arguments become object members.
1123 1649
1124At least initially, when you pass a C<tls>-argument to the constructor it 1650At least initially, when you pass a C<tls>-argument to the constructor it
1125will end up in C<< $handle->{tls} >>. Those members might be changes or 1651will end up in C<< $handle->{tls} >>. Those members might be changed or
1126mutated later on (for example C<tls> will hold the TLS connection object). 1652mutated later on (for example C<tls> will hold the TLS connection object).
1127 1653
1128=item * other object member names are prefixed with an C<_>. 1654=item * other object member names are prefixed with an C<_>.
1129 1655
1130All object members not explicitly documented (internal use) are prefixed 1656All object members not explicitly documented (internal use) are prefixed

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