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Revision 1.80 by root, Sun Jul 27 08:43:32 2008 UTC vs.
Revision 1.129 by root, Mon Jun 29 11:04:09 2009 UTC

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 = 4.22; 19our $VERSION = 4.42;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called when an end-of-file condition is detected, 84Set the callback to be called when an end-of-file condition is detected,
81i.e. in the case of a socket, when the other side has closed the 85i.e. in the case of a socket, when the other side has closed the
82connection cleanly. 86connection cleanly.
83 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
84While not mandatory, it is I<highly> recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
85otherwise 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
86waiting for data. 95waiting for data.
87 96
88If an EOF condition has been detected but no C<on_eof> callback has been 97If an EOF condition has been detected but no C<on_eof> callback has been
89set, then a fatal error will be raised with C<$!> set to <0>. 98set, then a fatal error will be raised with C<$!> set to <0>.
93This is the error callback, which is called when, well, some error 102This is the error callback, which is called when, well, some error
94occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
95connect or a read error. 104connect or a read error.
96 105
97Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
98fatal errors the handle object will be shut down and will not be 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
99usable. Non-fatal errors can be retried by simply returning, but it is 112Non-fatal errors can be retried by simply returning, but it is recommended
100recommended to simply ignore this parameter and instead abondon the handle 113to simply ignore this parameter and instead abondon the handle object
101object when this callback is invoked. 114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
102 116
103On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
104error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
105 119
106While 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
113and no read request is in the queue (unlike read queue callbacks, this 127and no read request is in the queue (unlike read queue callbacks, this
114callback will only be called when at least one octet of data is in the 128callback will only be called when at least one octet of data is in the
115read buffer). 129read buffer).
116 130
117To 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 >>
118method 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.
119 135
120When 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
121feed 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
122calling 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
123error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
138=item timeout => $fractional_seconds 154=item timeout => $fractional_seconds
139 155
140If non-zero, then this enables an "inactivity" timeout: whenever this many 156If non-zero, then this enables an "inactivity" timeout: whenever this many
141seconds pass without a successful read or write on the underlying file 157seconds pass without a successful read or write on the underlying file
142handle, the C<on_timeout> callback will be invoked (and if that one is 158handle, the C<on_timeout> callback will be invoked (and if that one is
143missing, an C<ETIMEDOUT> error will be raised). 159missing, a non-fatal C<ETIMEDOUT> error will be raised).
144 160
145Note that timeout processing is also active when you currently do not have 161Note that timeout processing is also active when you currently do not have
146any outstanding read or write requests: If you plan to keep the connection 162any outstanding read or write requests: If you plan to keep the connection
147idle then you should disable the timout temporarily or ignore the timeout 163idle then you should disable the timout temporarily or ignore the timeout
148in the C<on_timeout> callback. 164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
149 166
150Zero (the default) disables this timeout. 167Zero (the default) disables this timeout.
151 168
152=item on_timeout => $cb->($handle) 169=item on_timeout => $cb->($handle)
153 170
157 174
158=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
159 176
160If 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>)
161when 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
162avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
163 180
164For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
165be 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
166(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
167amount 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
168isn't finished). 185isn't finished).
169 186
170=item autocork => <boolean> 187=item autocork => <boolean>
171 188
172When disabled (the default), then C<push_write> will try to immediately 189When disabled (the default), then C<push_write> will try to immediately
173write the data to the handle if possible. This avoids having to register 190write the data to the handle, if possible. This avoids having to register
174a write watcher and wait for the next event loop iteration, but can be 191a write watcher and wait for the next event loop iteration, but can
175inefficient if you write multiple small chunks (this disadvantage is 192be inefficient if you write multiple small chunks (on the wire, this
176usually avoided by your kernel's nagle algorithm, see C<low_delay>). 193disadvantage is usually avoided by your kernel's nagle algorithm, see
194C<no_delay>, but this option can save costly syscalls).
177 195
178When enabled, then writes will always be queued till the next event loop 196When enabled, then writes will always be queued till the next event loop
179iteration. This is efficient when you do many small writes per iteration, 197iteration. This is efficient when you do many small writes per iteration,
180but less efficient when you do a single write only. 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.
181 200
182=item no_delay => <boolean> 201=item no_delay => <boolean>
183 202
184When doing small writes on sockets, your operating system kernel might 203When doing small writes on sockets, your operating system kernel might
185wait a bit for more data before actually sending it out. This is called 204wait a bit for more data before actually sending it out. This is called
186the Nagle algorithm, and usually it is beneficial. 205the Nagle algorithm, and usually it is beneficial.
187 206
188In some situations you want as low a delay as possible, which cna be 207In some situations you want as low a delay as possible, which can be
189accomplishd by setting this option to true. 208accomplishd by setting this option to a true value.
190 209
191The default is your opertaing system's default behaviour, this option 210The default is your opertaing system's default behaviour (most likely
192explicitly enables or disables it, if possible. 211enabled), this option explicitly enables or disables it, if possible.
193 212
194=item read_size => <bytes> 213=item read_size => <bytes>
195 214
196The 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
197during each (loop iteration). Default: C<8192>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
198 218
199=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
200 220
201Sets 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
202buffer: 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
203considered empty. 223considered empty.
204 224
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
205=item linger => <seconds> 230=item linger => <seconds>
206 231
207If non-zero (default: C<3600>), then the destructor of the 232If non-zero (default: C<3600>), then the destructor of the
208AnyEvent::Handle object will check wether there is still outstanding write 233AnyEvent::Handle object will check whether there is still outstanding
209data and will install a watcher that will write out this data. No errors 234write data and will install a watcher that will write this data to the
210will be reported (this mostly matches how the operating system treats 235socket. No errors will be reported (this mostly matches how the operating
211outstanding data at socket close time). 236system treats outstanding data at socket close time).
212 237
213This will not work for partial TLS data that could not yet been 238This will not work for partial TLS data that could not be encoded
214encoded. This data will be lost. 239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
215 241
216=item tls => "accept" | "connect" | Net::SSLeay::SSL object 242=item tls => "accept" | "connect" | Net::SSLeay::SSL object
217 243
218When this parameter is given, it enables TLS (SSL) mode, that means it 244When this parameter is given, it enables TLS (SSL) mode, that means
219will start making tls handshake and will transparently encrypt/decrypt 245AnyEvent will start a TLS handshake as soon as the conenction has been
220data. 246established and will transparently encrypt/decrypt data afterwards.
221 247
222TLS mode requires Net::SSLeay to be installed (it will be loaded 248TLS mode requires Net::SSLeay to be installed (it will be loaded
223automatically 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.
224 252
225For 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
226connection, use C<connect> mode. 254C<accept>, and for the TLS client side of a connection, use C<connect>
255mode.
227 256
228You can also provide your own TLS connection object, but you have 257You can also provide your own TLS connection object, but you have
229to 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>
230or 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
231AnyEvent::Handle. 260AnyEvent::Handle.
232 261
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
233See 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.
234 268
235=item tls_ctx => $ssl_ctx 269=item tls_ctx => $ssl_ctx
236 270
237Use 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
238(unless a connection object was specified directly). If this parameter is 272(unless a connection object was specified directly). If this parameter is
239missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 273missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
240 274
241=item json => JSON or JSON::XS object 275=item json => JSON or JSON::XS object
242 276
243This 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.
244 278
245If you don't supply it, then AnyEvent::Handle will create and use a 279If you don't supply it, then AnyEvent::Handle will create and use a
246suitable one, which will write and expect UTF-8 encoded JSON texts. 280suitable one (on demand), which will write and expect UTF-8 encoded JSON
281texts.
247 282
248Note 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
249use this functionality, as AnyEvent does not have a dependency itself. 284use this functionality, as AnyEvent does not have a dependency itself.
250 285
251=item filter_r => $cb
252
253=item filter_w => $cb
254
255These exist, but are undocumented at this time.
256
257=back 286=back
258 287
259=cut 288=cut
260 289
261sub new { 290sub new {
265 294
266 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
267 296
268 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
269 298
270 if ($self->{tls}) {
271 require Net::SSLeay;
272 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
273 } 300 if $self->{tls};
274 301
275 $self->{_activity} = AnyEvent->now; 302 $self->{_activity} = AnyEvent->now;
276 $self->_timeout; 303 $self->_timeout;
277 304
278 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
285} 312}
286 313
287sub _shutdown { 314sub _shutdown {
288 my ($self) = @_; 315 my ($self) = @_;
289 316
290 delete $self->{_tw}; 317 delete @$self{qw(_tw _rw _ww fh rbuf wbuf on_read _queue)};
291 delete $self->{_rw};
292 delete $self->{_ww};
293 delete $self->{fh};
294 318
295 $self->stoptls; 319 &_freetls;
296} 320}
297 321
298sub _error { 322sub _error {
299 my ($self, $errno, $fatal) = @_; 323 my ($self, $errno, $fatal) = @_;
300 324
303 327
304 $! = $errno; 328 $! = $errno;
305 329
306 if ($self->{on_error}) { 330 if ($self->{on_error}) {
307 $self->{on_error}($self, $fatal); 331 $self->{on_error}($self, $fatal);
308 } else { 332 } elsif ($self->{fh}) {
309 Carp::croak "AnyEvent::Handle uncaught error: $!"; 333 Carp::croak "AnyEvent::Handle uncaught error: $!";
310 } 334 }
311} 335}
312 336
313=item $fh = $handle->fh 337=item $fh = $handle->fh
314 338
315This 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.
316 340
317=cut 341=cut
318 342
319sub fh { $_[0]{fh} } 343sub fh { $_[0]{fh} }
320 344
338 $_[0]{on_eof} = $_[1]; 362 $_[0]{on_eof} = $_[1];
339} 363}
340 364
341=item $handle->on_timeout ($cb) 365=item $handle->on_timeout ($cb)
342 366
343Replace the current C<on_timeout> callback, or disables the callback 367Replace the current C<on_timeout> callback, or disables the callback (but
344(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 368not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
345argument. 369argument and method.
346 370
347=cut 371=cut
348 372
349sub on_timeout { 373sub on_timeout {
350 $_[0]{on_timeout} = $_[1]; 374 $_[0]{on_timeout} = $_[1];
351} 375}
352 376
353=item $handle->autocork ($boolean) 377=item $handle->autocork ($boolean)
354 378
355Enables or disables the current autocork behaviour (see C<autocork> 379Enables or disables the current autocork behaviour (see C<autocork>
356constructor argument). 380constructor argument). Changes will only take effect on the next write.
357 381
358=cut 382=cut
383
384sub autocork {
385 $_[0]{autocork} = $_[1];
386}
359 387
360=item $handle->no_delay ($boolean) 388=item $handle->no_delay ($boolean)
361 389
362Enables or disables the C<no_delay> setting (see constructor argument of 390Enables or disables the C<no_delay> setting (see constructor argument of
363the same name for details). 391the same name for details).
456 my ($self, $cb) = @_; 484 my ($self, $cb) = @_;
457 485
458 $self->{on_drain} = $cb; 486 $self->{on_drain} = $cb;
459 487
460 $cb->($self) 488 $cb->($self)
461 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 489 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
462} 490}
463 491
464=item $handle->push_write ($data) 492=item $handle->push_write ($data)
465 493
466Queues 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
483 substr $self->{wbuf}, 0, $len, ""; 511 substr $self->{wbuf}, 0, $len, "";
484 512
485 $self->{_activity} = AnyEvent->now; 513 $self->{_activity} = AnyEvent->now;
486 514
487 $self->{on_drain}($self) 515 $self->{on_drain}($self)
488 if $self->{low_water_mark} >= length $self->{wbuf} 516 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
489 && $self->{on_drain}; 517 && $self->{on_drain};
490 518
491 delete $self->{_ww} unless length $self->{wbuf}; 519 delete $self->{_ww} unless length $self->{wbuf};
492 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 520 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
493 $self->_error ($!, 1); 521 $self->_error ($!, 1);
517 545
518 @_ = ($WH{$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")
519 ->($self, @_); 547 ->($self, @_);
520 } 548 }
521 549
522 if ($self->{filter_w}) { 550 if ($self->{tls}) {
523 $self->{filter_w}($self, \$_[0]); 551 $self->{_tls_wbuf} .= $_[0];
552
553 &_dotls ($self);
524 } else { 554 } else {
525 $self->{wbuf} .= $_[0]; 555 $self->{wbuf} .= $_[0];
526 $self->_drain_wbuf; 556 $self->_drain_wbuf;
527 } 557 }
528} 558}
545=cut 575=cut
546 576
547register_write_type netstring => sub { 577register_write_type netstring => sub {
548 my ($self, $string) = @_; 578 my ($self, $string) = @_;
549 579
550 sprintf "%d:%s,", (length $string), $string 580 (length $string) . ":$string,"
551}; 581};
552 582
553=item packstring => $format, $data 583=item packstring => $format, $data
554 584
555An octet string prefixed with an encoded length. The encoding C<$format> 585An octet string prefixed with an encoded length. The encoding C<$format>
729 759
730 if ( 760 if (
731 defined $self->{rbuf_max} 761 defined $self->{rbuf_max}
732 && $self->{rbuf_max} < length $self->{rbuf} 762 && $self->{rbuf_max} < length $self->{rbuf}
733 ) { 763 ) {
734 return $self->_error (&Errno::ENOSPC, 1); 764 $self->_error (&Errno::ENOSPC, 1), return;
735 } 765 }
736 766
737 while () { 767 while () {
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};
771
738 my $len = length $self->{rbuf}; 772 my $len = length $self->{rbuf};
739 773
740 if (my $cb = shift @{ $self->{_queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
741 unless ($cb->($self)) { 775 unless ($cb->($self)) {
742 if ($self->{_eof}) { 776 if ($self->{_eof}) {
743 # 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)
744 $self->_error (&Errno::EPIPE, 1), last; 778 $self->_error (&Errno::EPIPE, 1), return;
745 } 779 }
746 780
747 unshift @{ $self->{_queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
748 last; 782 last;
749 } 783 }
757 && !@{ $self->{_queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
758 && $self->{on_read} # but we still have on_read 792 && $self->{on_read} # but we still have on_read
759 ) { 793 ) {
760 # no further data will arrive 794 # no further data will arrive
761 # so no progress can be made 795 # so no progress can be made
762 $self->_error (&Errno::EPIPE, 1), last 796 $self->_error (&Errno::EPIPE, 1), return
763 if $self->{_eof}; 797 if $self->{_eof};
764 798
765 last; # more data might arrive 799 last; # more data might arrive
766 } 800 }
767 } else { 801 } else {
768 # read side becomes idle 802 # read side becomes idle
769 delete $self->{_rw}; 803 delete $self->{_rw} unless $self->{tls};
770 last; 804 last;
771 } 805 }
772 } 806 }
773 807
774 if ($self->{_eof}) { 808 if ($self->{_eof}) {
803 837
804=item $handle->rbuf 838=item $handle->rbuf
805 839
806Returns the read buffer (as a modifiable lvalue). 840Returns the read buffer (as a modifiable lvalue).
807 841
808You can access the read buffer directly as the C<< ->{rbuf} >> member, if 842You can access the read buffer directly as the C<< ->{rbuf} >>
809you want. 843member, if you want. However, the only operation allowed on the
844read buffer (apart from looking at it) is removing data from its
845beginning. Otherwise modifying or appending to it is not allowed and will
846lead to hard-to-track-down bugs.
810 847
811NOTE: The read buffer should only be used or modified if the C<on_read>, 848NOTE: The read buffer should only be used or modified if the C<on_read>,
812C<push_read> or C<unshift_read> methods are used. The other read methods 849C<push_read> or C<unshift_read> methods are used. The other read methods
813automatically manage the read buffer. 850automatically manage the read buffer.
814 851
1069An octet string prefixed with an encoded length. The encoding C<$format> 1106An octet string prefixed with an encoded length. The encoding C<$format>
1070uses the same format as a Perl C<pack> format, but must specify a single 1107uses the same format as a Perl C<pack> format, but must specify a single
1071integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1108integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1072optional C<!>, C<< < >> or C<< > >> modifier). 1109optional C<!>, C<< < >> or C<< > >> modifier).
1073 1110
1074DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1111For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1112EPP uses a prefix of C<N> (4 octtes).
1075 1113
1076Example: read a block of data prefixed by its length in BER-encoded 1114Example: read a block of data prefixed by its length in BER-encoded
1077format (very efficient). 1115format (very efficient).
1078 1116
1079 $handle->push_read (packstring => "w", sub { 1117 $handle->push_read (packstring => "w", sub {
1109 } 1147 }
1110}; 1148};
1111 1149
1112=item json => $cb->($handle, $hash_or_arrayref) 1150=item json => $cb->($handle, $hash_or_arrayref)
1113 1151
1114Reads a JSON object or array, decodes it and passes it to the callback. 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.
1115 1154
1116If a C<json> object was passed to the constructor, then that will be used 1155If a C<json> object was passed to the constructor, then that will be used
1117for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1156for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1118 1157
1119This read type uses the incremental parser available with JSON version 1158This read type uses the incremental parser available with JSON version
1136 my $rbuf = \$self->{rbuf}; 1175 my $rbuf = \$self->{rbuf};
1137 1176
1138 my $json = $self->{json} ||= JSON->new->utf8; 1177 my $json = $self->{json} ||= JSON->new->utf8;
1139 1178
1140 sub { 1179 sub {
1141 my $ref = $json->incr_parse ($self->{rbuf}); 1180 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1142 1181
1143 if ($ref) { 1182 if ($ref) {
1144 $self->{rbuf} = $json->incr_text; 1183 $self->{rbuf} = $json->incr_text;
1145 $json->incr_text = ""; 1184 $json->incr_text = "";
1146 $cb->($self, $ref); 1185 $cb->($self, $ref);
1147 1186
1148 1 1187 1
1188 } elsif ($@) {
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 ()
1149 } else { 1198 } else {
1150 $self->{rbuf} = ""; 1199 $self->{rbuf} = "";
1200
1151 () 1201 ()
1152 } 1202 }
1153 } 1203 }
1154}; 1204};
1155 1205
1232Note that AnyEvent::Handle will automatically C<start_read> for you when 1282Note that AnyEvent::Handle will automatically C<start_read> for you when
1233you change the C<on_read> callback or push/unshift a read callback, and it 1283you change the C<on_read> callback or push/unshift a read callback, and it
1234will automatically C<stop_read> for you when neither C<on_read> is set nor 1284will automatically C<stop_read> for you when neither C<on_read> is set nor
1235there are any read requests in the queue. 1285there are any read requests in the queue.
1236 1286
1287These methods will have no effect when in TLS mode (as TLS doesn't support
1288half-duplex connections).
1289
1237=cut 1290=cut
1238 1291
1239sub stop_read { 1292sub stop_read {
1240 my ($self) = @_; 1293 my ($self) = @_;
1241 1294
1242 delete $self->{_rw}; 1295 delete $self->{_rw} unless $self->{tls};
1243} 1296}
1244 1297
1245sub start_read { 1298sub start_read {
1246 my ($self) = @_; 1299 my ($self) = @_;
1247 1300
1248 unless ($self->{_rw} || $self->{_eof}) { 1301 unless ($self->{_rw} || $self->{_eof}) {
1249 Scalar::Util::weaken $self; 1302 Scalar::Util::weaken $self;
1250 1303
1251 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1304 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1252 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1305 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1253 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;
1254 1307
1255 if ($len > 0) { 1308 if ($len > 0) {
1256 $self->{_activity} = AnyEvent->now; 1309 $self->{_activity} = AnyEvent->now;
1257 1310
1258 $self->{filter_r} 1311 if ($self->{tls}) {
1259 ? $self->{filter_r}($self, $rbuf) 1312 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1260 : $self->{_in_drain} || $self->_drain_rbuf; 1313
1314 &_dotls ($self);
1315 } else {
1316 $self->_drain_rbuf unless $self->{_in_drain};
1317 }
1261 1318
1262 } elsif (defined $len) { 1319 } elsif (defined $len) {
1263 delete $self->{_rw}; 1320 delete $self->{_rw};
1264 $self->{_eof} = 1; 1321 $self->{_eof} = 1;
1265 $self->_drain_rbuf unless $self->{_in_drain}; 1322 $self->_drain_rbuf unless $self->{_in_drain};
1269 } 1326 }
1270 }); 1327 });
1271 } 1328 }
1272} 1329}
1273 1330
1331# poll the write BIO and send the data if applicable
1274sub _dotls { 1332sub _dotls {
1275 my ($self) = @_; 1333 my ($self) = @_;
1276 1334
1277 my $buf; 1335 my $tmp;
1278 1336
1279 if (length $self->{_tls_wbuf}) { 1337 if (length $self->{_tls_wbuf}) {
1280 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1338 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1281 substr $self->{_tls_wbuf}, 0, $len, ""; 1339 substr $self->{_tls_wbuf}, 0, $tmp, "";
1282 } 1340 }
1283 } 1341 }
1284 1342
1285 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1286 $self->{wbuf} .= $buf;
1287 $self->_drain_wbuf;
1288 }
1289
1290 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1343 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1291 if (length $buf) { 1344 unless (length $tmp) {
1292 $self->{rbuf} .= $buf;
1293 $self->_drain_rbuf unless $self->{_in_drain};
1294 } else {
1295 # let's treat SSL-eof as we treat normal EOF 1345 # let's treat SSL-eof as we treat normal EOF
1346 delete $self->{_rw};
1296 $self->{_eof} = 1; 1347 $self->{_eof} = 1;
1297 $self->_shutdown; 1348 &_freetls;
1298 return;
1299 } 1349 }
1300 }
1301 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
1302 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1356 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1303 1357
1304 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1358 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1305 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1359 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1306 return $self->_error ($!, 1); 1360 return $self->_error ($!, 1);
1307 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1361 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1308 return $self->_error (&Errno::EIO, 1); 1362 return $self->_error (&Errno::EIO, 1);
1309 } 1363 }
1310 1364
1311 # all others are fine for our purposes 1365 # all other errors are fine for our purposes
1366 }
1367
1368 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1369 $self->{wbuf} .= $tmp;
1370 $self->_drain_wbuf;
1312 } 1371 }
1313} 1372}
1314 1373
1315=item $handle->starttls ($tls[, $tls_ctx]) 1374=item $handle->starttls ($tls[, $tls_ctx])
1316 1375
1326 1385
1327The TLS connection object will end up in C<< $handle->{tls} >> after this 1386The TLS connection object will end up in C<< $handle->{tls} >> after this
1328call and can be used or changed to your liking. Note that the handshake 1387call and can be used or changed to your liking. Note that the handshake
1329might have already started when this function returns. 1388might have already started when this function returns.
1330 1389
1390If it an error to start a TLS handshake more than once per
1391AnyEvent::Handle object (this is due to bugs in OpenSSL).
1392
1331=cut 1393=cut
1332 1394
1333sub starttls { 1395sub starttls {
1334 my ($self, $ssl, $ctx) = @_; 1396 my ($self, $ssl, $ctx) = @_;
1335 1397
1336 $self->stoptls; 1398 require Net::SSLeay;
1337 1399
1400 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1401 if $self->{tls};
1402
1338 if ($ssl eq "accept") { 1403 if ($ssl eq "accept") {
1339 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1404 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1340 Net::SSLeay::set_accept_state ($ssl); 1405 Net::SSLeay::set_accept_state ($ssl);
1341 } elsif ($ssl eq "connect") { 1406 } elsif ($ssl eq "connect") {
1342 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1407 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1348 # 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)
1349 # but the openssl maintainers basically said: "trust us, it just works". 1414 # but the openssl maintainers basically said: "trust us, it just works".
1350 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1415 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1351 # and mismaintained ssleay-module doesn't even offer them). 1416 # and mismaintained ssleay-module doesn't even offer them).
1352 # 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.
1353 Net::SSLeay::CTX_set_mode ($self->{tls}, 1425 Net::SSLeay::CTX_set_mode ($self->{tls},
1354 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1426 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1355 | (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));
1356 1428
1357 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1358 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1430 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1359 1431
1360 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1432 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1361 1433
1362 $self->{filter_w} = sub { 1434 &_dotls; # need to trigger the initial handshake
1363 $_[0]{_tls_wbuf} .= ${$_[1]}; 1435 $self->start_read; # make sure we actually do read
1364 &_dotls;
1365 };
1366 $self->{filter_r} = sub {
1367 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1368 &_dotls;
1369 };
1370} 1436}
1371 1437
1372=item $handle->stoptls 1438=item $handle->stoptls
1373 1439
1374Destroys the SSL connection, if any. Partial read or write data will be 1440Shuts down the SSL connection - this makes a proper EOF handshake by
1375lost. 1441sending a close notify to the other side, but since OpenSSL doesn't
1442support non-blocking shut downs, it is not possible to re-use the stream
1443afterwards.
1376 1444
1377=cut 1445=cut
1378 1446
1379sub stoptls { 1447sub stoptls {
1380 my ($self) = @_; 1448 my ($self) = @_;
1381 1449
1450 if ($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
1382 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1466 Net::SSLeay::free (delete $self->{tls});
1383 1467
1384 delete $self->{_rbio}; 1468 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1385 delete $self->{_wbio};
1386 delete $self->{_tls_wbuf};
1387 delete $self->{filter_r};
1388 delete $self->{filter_w};
1389} 1469}
1390 1470
1391sub DESTROY { 1471sub DESTROY {
1392 my $self = shift; 1472 my ($self) = @_;
1393 1473
1394 $self->stoptls; 1474 &_freetls;
1395 1475
1396 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1476 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1397 1477
1398 if ($linger && length $self->{wbuf}) { 1478 if ($linger && length $self->{wbuf}) {
1399 my $fh = delete $self->{fh}; 1479 my $fh = delete $self->{fh};
1414 @linger = (); 1494 @linger = ();
1415 }); 1495 });
1416 } 1496 }
1417} 1497}
1418 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 = ();
1522}
1523
1419=item AnyEvent::Handle::TLS_CTX 1524=item AnyEvent::Handle::TLS_CTX
1420 1525
1421This function creates and returns the Net::SSLeay::CTX object used by 1526This function creates and returns the Net::SSLeay::CTX object used by
1422default for TLS mode. 1527default for TLS mode.
1423 1528
1451 } 1556 }
1452} 1557}
1453 1558
1454=back 1559=back
1455 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
1456=head1 SUBCLASSING AnyEvent::Handle 1633=head1 SUBCLASSING AnyEvent::Handle
1457 1634
1458In many cases, you might want to subclass AnyEvent::Handle. 1635In many cases, you might want to subclass AnyEvent::Handle.
1459 1636
1460To make this easier, a given version of AnyEvent::Handle uses these 1637To make this easier, a given version of AnyEvent::Handle uses these

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