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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.82 by root, Thu Aug 21 18:45:16 2008 UTC vs.
Revision 1.132 by elmex, Thu Jul 2 22:25:13 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 = 4.232; 19our $VERSION = 4.45;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
60 63
61=head1 METHODS 64=head1 METHODS
62 65
63=over 4 66=over 4
64 67
65=item B<new (%args)> 68=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
66 69
67The constructor supports these arguments (all as key => value pairs). 70The constructor supports these arguments (all as C<< key => value >> pairs).
68 71
69=over 4 72=over 4
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
84For sockets, this just means that the other side has stopped sending data, 88For sockets, this just means that the other side has stopped sending data,
85you can still try to write data, and, in fact, one can return from the eof 89you can still try to write data, and, in fact, one can return from the EOF
86callback and continue writing data, as only the read part has been shut 90callback and continue writing data, as only the read part has been shut
87down. 91down.
88 92
89While 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,
90otherwise 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
91waiting for data. 95waiting for data.
92 96
93If 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
94set, 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>.
99occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
100connect or a read error. 104connect or a read error.
101 105
102Some 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
103fatal errors the handle object will be shut down and will not be usable 107fatal errors the handle object will be shut down and will not be usable
104(but you are free to look at the current C< ->rbuf >). Examples of fatal 108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
105errors are an EOF condition with active (but unsatisifable) read watchers 109errors are an EOF condition with active (but unsatisifable) read watchers
106(C<EPIPE>) or I/O errors. 110(C<EPIPE>) or I/O errors.
107 111
108Non-fatal errors can be retried by simply returning, but it is recommended 112Non-fatal errors can be retried by simply returning, but it is recommended
109to simply ignore this parameter and instead abondon the handle object 113to simply ignore this parameter and instead abondon the handle object
123and 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
124callback 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
125read buffer). 129read buffer).
126 130
127To 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 >>
128method 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.
129 135
130When 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
131feed 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
132calling 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
133error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
148=item timeout => $fractional_seconds 154=item timeout => $fractional_seconds
149 155
150If non-zero, then this enables an "inactivity" timeout: whenever this many 156If non-zero, then this enables an "inactivity" timeout: whenever this many
151seconds pass without a successful read or write on the underlying file 157seconds pass without a successful read or write on the underlying file
152handle, 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
153missing, an C<ETIMEDOUT> error will be raised). 159missing, a non-fatal C<ETIMEDOUT> error will be raised).
154 160
155Note 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
156any 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
157idle then you should disable the timout temporarily or ignore the timeout 163idle then you should disable the timout temporarily or ignore the timeout
158in the C<on_timeout> callback. 164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
159 166
160Zero (the default) disables this timeout. 167Zero (the default) disables this timeout.
161 168
162=item on_timeout => $cb->($handle) 169=item on_timeout => $cb->($handle)
163 170
167 174
168=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
169 176
170If 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>)
171when 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
172avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
173 180
174For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
175be 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
176(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
177amount 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
178isn't finished). 185isn't finished).
179 186
180=item autocork => <boolean> 187=item autocork => <boolean>
181 188
182When disabled (the default), then C<push_write> will try to immediately 189When disabled (the default), then C<push_write> will try to immediately
183write 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
184a 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
185inefficient if you write multiple small chunks (this disadvantage is 192be inefficient if you write multiple small chunks (on the wire, this
186usually 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).
187 195
188When 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
189iteration. This is efficient when you do many small writes per iteration, 197iteration. This is efficient when you do many small writes per iteration,
190but 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.
191 200
192=item no_delay => <boolean> 201=item no_delay => <boolean>
193 202
194When doing small writes on sockets, your operating system kernel might 203When doing small writes on sockets, your operating system kernel might
195wait 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
196the Nagle algorithm, and usually it is beneficial. 205the Nagle algorithm, and usually it is beneficial.
197 206
198In 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
199accomplishd by setting this option to true. 208accomplishd by setting this option to a true value.
200 209
201The default is your opertaing system's default behaviour, this option 210The default is your opertaing system's default behaviour (most likely
202explicitly enables or disables it, if possible. 211enabled), this option explicitly enables or disables it, if possible.
203 212
204=item read_size => <bytes> 213=item read_size => <bytes>
205 214
206The 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
207during each (loop iteration). Default: C<8192>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
208 218
209=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
210 220
211Sets 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
212buffer: 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
213considered empty. 223considered empty.
214 224
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
215=item linger => <seconds> 230=item linger => <seconds>
216 231
217If non-zero (default: C<3600>), then the destructor of the 232If non-zero (default: C<3600>), then the destructor of the
218AnyEvent::Handle object will check wether there is still outstanding write 233AnyEvent::Handle object will check whether there is still outstanding
219data 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
220will be reported (this mostly matches how the operating system treats 235socket. No errors will be reported (this mostly matches how the operating
221outstanding data at socket close time). 236system treats outstanding data at socket close time).
222 237
223This 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
224encoded. This data will be lost. 239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
241
242=item common_name => $string
243
244The common name used by some verification methods (most notably SSL/TLS)
245associated with this connection. Usually this is the remote hostname used
246to connect, but can be almost anything.
225 247
226=item tls => "accept" | "connect" | Net::SSLeay::SSL object 248=item tls => "accept" | "connect" | Net::SSLeay::SSL object
227 249
228When this parameter is given, it enables TLS (SSL) mode, that means it 250When this parameter is given, it enables TLS (SSL) mode, that means
229will start making tls handshake and will transparently encrypt/decrypt 251AnyEvent will start a TLS handshake as soon as the conenction has been
230data. 252established and will transparently encrypt/decrypt data afterwards.
231 253
232TLS mode requires Net::SSLeay to be installed (it will be loaded 254TLS mode requires Net::SSLeay to be installed (it will be loaded
233automatically when you try to create a TLS handle). 255automatically when you try to create a TLS handle): this module doesn't
256have a dependency on that module, so if your module requires it, you have
257to add the dependency yourself.
234 258
235For the TLS server side, use C<accept>, and for the TLS client side of a 259Unlike TCP, TLS has a server and client side: for the TLS server side, use
236connection, use C<connect> mode. 260C<accept>, and for the TLS client side of a connection, use C<connect>
261mode.
237 262
238You can also provide your own TLS connection object, but you have 263You can also provide your own TLS connection object, but you have
239to make sure that you call either C<Net::SSLeay::set_connect_state> 264to make sure that you call either C<Net::SSLeay::set_connect_state>
240or C<Net::SSLeay::set_accept_state> on it before you pass it to 265or C<Net::SSLeay::set_accept_state> on it before you pass it to
241AnyEvent::Handle. 266AnyEvent::Handle. Also, this module will take ownership of this connection
267object.
242 268
269At some future point, AnyEvent::Handle might switch to another TLS
270implementation, then the option to use your own session object will go
271away.
272
273B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
274passing in the wrong integer will lead to certain crash. This most often
275happens when one uses a stylish C<< tls => 1 >> and is surprised about the
276segmentation fault.
277
243See the C<starttls> method if you need to start TLS negotiation later. 278See the C<< ->starttls >> method for when need to start TLS negotiation later.
244 279
245=item tls_ctx => $ssl_ctx 280=item tls_ctx => $anyevent_tls
246 281
247Use the given Net::SSLeay::CTX object to create the new TLS connection 282Use the given C<AnyEvent::TLS> object to create the new TLS connection
248(unless a connection object was specified directly). If this parameter is 283(unless a connection object was specified directly). If this parameter is
249missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 284missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
250 285
286Instead of an object, you can also specify a hash reference with C<< key
287=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
288new TLS context object.
289
251=item json => JSON or JSON::XS object 290=item json => JSON or JSON::XS object
252 291
253This is the json coder object used by the C<json> read and write types. 292This is the json coder object used by the C<json> read and write types.
254 293
255If you don't supply it, then AnyEvent::Handle will create and use a 294If you don't supply it, then AnyEvent::Handle will create and use a
256suitable one, which will write and expect UTF-8 encoded JSON texts. 295suitable one (on demand), which will write and expect UTF-8 encoded JSON
296texts.
257 297
258Note that you are responsible to depend on the JSON module if you want to 298Note that you are responsible to depend on the JSON module if you want to
259use this functionality, as AnyEvent does not have a dependency itself. 299use this functionality, as AnyEvent does not have a dependency itself.
260 300
261=item filter_r => $cb
262
263=item filter_w => $cb
264
265These exist, but are undocumented at this time.
266
267=back 301=back
268 302
269=cut 303=cut
270 304
271sub new { 305sub new {
272 my $class = shift; 306 my $class = shift;
273
274 my $self = bless { @_ }, $class; 307 my $self = bless { @_ }, $class;
275 308
276 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 309 $self->{fh} or Carp::croak "mandatory argument fh is missing";
277 310
278 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 311 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
279
280 if ($self->{tls}) {
281 require Net::SSLeay;
282 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
283 }
284 312
285 $self->{_activity} = AnyEvent->now; 313 $self->{_activity} = AnyEvent->now;
286 $self->_timeout; 314 $self->_timeout;
287 315
316 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
317
318 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
319 if $self->{tls};
320
288 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 321 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
289 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
290 322
291 $self->start_read 323 $self->start_read
292 if $self->{on_read}; 324 if $self->{on_read};
293 325
294 $self 326 $self->{fh} && $self
295} 327}
296 328
297sub _shutdown { 329sub _shutdown {
298 my ($self) = @_; 330 my ($self) = @_;
299 331
300 delete $self->{_tw}; 332 delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
301 delete $self->{_rw}; 333 $self->{_eof} = 1; # tell starttls et. al to stop trying
302 delete $self->{_ww};
303 delete $self->{fh};
304 334
305 $self->stoptls; 335 &_freetls;
306
307 delete $self->{on_read};
308 delete $self->{_queue};
309} 336}
310 337
311sub _error { 338sub _error {
312 my ($self, $errno, $fatal) = @_; 339 my ($self, $errno, $fatal) = @_;
313 340
316 343
317 $! = $errno; 344 $! = $errno;
318 345
319 if ($self->{on_error}) { 346 if ($self->{on_error}) {
320 $self->{on_error}($self, $fatal); 347 $self->{on_error}($self, $fatal);
321 } else { 348 } elsif ($self->{fh}) {
322 Carp::croak "AnyEvent::Handle uncaught error: $!"; 349 Carp::croak "AnyEvent::Handle uncaught error: $!";
323 } 350 }
324} 351}
325 352
326=item $fh = $handle->fh 353=item $fh = $handle->fh
327 354
328This method returns the file handle of the L<AnyEvent::Handle> object. 355This method returns the file handle used to create the L<AnyEvent::Handle> object.
329 356
330=cut 357=cut
331 358
332sub fh { $_[0]{fh} } 359sub fh { $_[0]{fh} }
333 360
351 $_[0]{on_eof} = $_[1]; 378 $_[0]{on_eof} = $_[1];
352} 379}
353 380
354=item $handle->on_timeout ($cb) 381=item $handle->on_timeout ($cb)
355 382
356Replace the current C<on_timeout> callback, or disables the callback 383Replace the current C<on_timeout> callback, or disables the callback (but
357(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 384not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
358argument. 385argument and method.
359 386
360=cut 387=cut
361 388
362sub on_timeout { 389sub on_timeout {
363 $_[0]{on_timeout} = $_[1]; 390 $_[0]{on_timeout} = $_[1];
364} 391}
365 392
366=item $handle->autocork ($boolean) 393=item $handle->autocork ($boolean)
367 394
368Enables or disables the current autocork behaviour (see C<autocork> 395Enables or disables the current autocork behaviour (see C<autocork>
369constructor argument). 396constructor argument). Changes will only take effect on the next write.
370 397
371=cut 398=cut
399
400sub autocork {
401 $_[0]{autocork} = $_[1];
402}
372 403
373=item $handle->no_delay ($boolean) 404=item $handle->no_delay ($boolean)
374 405
375Enables or disables the C<no_delay> setting (see constructor argument of 406Enables or disables the C<no_delay> setting (see constructor argument of
376the same name for details). 407the same name for details).
469 my ($self, $cb) = @_; 500 my ($self, $cb) = @_;
470 501
471 $self->{on_drain} = $cb; 502 $self->{on_drain} = $cb;
472 503
473 $cb->($self) 504 $cb->($self)
474 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 505 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
475} 506}
476 507
477=item $handle->push_write ($data) 508=item $handle->push_write ($data)
478 509
479Queues the given scalar to be written. You can push as much data as you 510Queues the given scalar to be written. You can push as much data as you
496 substr $self->{wbuf}, 0, $len, ""; 527 substr $self->{wbuf}, 0, $len, "";
497 528
498 $self->{_activity} = AnyEvent->now; 529 $self->{_activity} = AnyEvent->now;
499 530
500 $self->{on_drain}($self) 531 $self->{on_drain}($self)
501 if $self->{low_water_mark} >= length $self->{wbuf} 532 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
502 && $self->{on_drain}; 533 && $self->{on_drain};
503 534
504 delete $self->{_ww} unless length $self->{wbuf}; 535 delete $self->{_ww} unless length $self->{wbuf};
505 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 536 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
506 $self->_error ($!, 1); 537 $self->_error ($!, 1);
530 561
531 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 562 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
532 ->($self, @_); 563 ->($self, @_);
533 } 564 }
534 565
535 if ($self->{filter_w}) { 566 if ($self->{tls}) {
536 $self->{filter_w}($self, \$_[0]); 567 $self->{_tls_wbuf} .= $_[0];
568
569 &_dotls ($self);
537 } else { 570 } else {
538 $self->{wbuf} .= $_[0]; 571 $self->{wbuf} .= $_[0];
539 $self->_drain_wbuf; 572 $self->_drain_wbuf;
540 } 573 }
541} 574}
558=cut 591=cut
559 592
560register_write_type netstring => sub { 593register_write_type netstring => sub {
561 my ($self, $string) = @_; 594 my ($self, $string) = @_;
562 595
563 sprintf "%d:%s,", (length $string), $string 596 (length $string) . ":$string,"
564}; 597};
565 598
566=item packstring => $format, $data 599=item packstring => $format, $data
567 600
568An octet string prefixed with an encoded length. The encoding C<$format> 601An octet string prefixed with an encoded length. The encoding C<$format>
746 ) { 779 ) {
747 $self->_error (&Errno::ENOSPC, 1), return; 780 $self->_error (&Errno::ENOSPC, 1), return;
748 } 781 }
749 782
750 while () { 783 while () {
784 # we need to use a separate tls read buffer, as we must not receive data while
785 # we are draining the buffer, and this can only happen with TLS.
786 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
787
751 my $len = length $self->{rbuf}; 788 my $len = length $self->{rbuf};
752 789
753 if (my $cb = shift @{ $self->{_queue} }) { 790 if (my $cb = shift @{ $self->{_queue} }) {
754 unless ($cb->($self)) { 791 unless ($cb->($self)) {
755 if ($self->{_eof}) { 792 if ($self->{_eof}) {
777 814
778 last; # more data might arrive 815 last; # more data might arrive
779 } 816 }
780 } else { 817 } else {
781 # read side becomes idle 818 # read side becomes idle
782 delete $self->{_rw}; 819 delete $self->{_rw} unless $self->{tls};
783 last; 820 last;
784 } 821 }
785 } 822 }
786 823
787 if ($self->{_eof}) { 824 if ($self->{_eof}) {
816 853
817=item $handle->rbuf 854=item $handle->rbuf
818 855
819Returns the read buffer (as a modifiable lvalue). 856Returns the read buffer (as a modifiable lvalue).
820 857
821You can access the read buffer directly as the C<< ->{rbuf} >> member, if 858You can access the read buffer directly as the C<< ->{rbuf} >>
822you want. 859member, if you want. However, the only operation allowed on the
860read buffer (apart from looking at it) is removing data from its
861beginning. Otherwise modifying or appending to it is not allowed and will
862lead to hard-to-track-down bugs.
823 863
824NOTE: The read buffer should only be used or modified if the C<on_read>, 864NOTE: The read buffer should only be used or modified if the C<on_read>,
825C<push_read> or C<unshift_read> methods are used. The other read methods 865C<push_read> or C<unshift_read> methods are used. The other read methods
826automatically manage the read buffer. 866automatically manage the read buffer.
827 867
1082An octet string prefixed with an encoded length. The encoding C<$format> 1122An octet string prefixed with an encoded length. The encoding C<$format>
1083uses the same format as a Perl C<pack> format, but must specify a single 1123uses the same format as a Perl C<pack> format, but must specify a single
1084integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1124integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1085optional C<!>, C<< < >> or C<< > >> modifier). 1125optional C<!>, C<< < >> or C<< > >> modifier).
1086 1126
1087DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1127For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1128EPP uses a prefix of C<N> (4 octtes).
1088 1129
1089Example: read a block of data prefixed by its length in BER-encoded 1130Example: read a block of data prefixed by its length in BER-encoded
1090format (very efficient). 1131format (very efficient).
1091 1132
1092 $handle->push_read (packstring => "w", sub { 1133 $handle->push_read (packstring => "w", sub {
1122 } 1163 }
1123}; 1164};
1124 1165
1125=item json => $cb->($handle, $hash_or_arrayref) 1166=item json => $cb->($handle, $hash_or_arrayref)
1126 1167
1127Reads a JSON object or array, decodes it and passes it to the callback. 1168Reads a JSON object or array, decodes it and passes it to the
1169callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1128 1170
1129If a C<json> object was passed to the constructor, then that will be used 1171If a C<json> object was passed to the constructor, then that will be used
1130for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1172for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1131 1173
1132This read type uses the incremental parser available with JSON version 1174This read type uses the incremental parser available with JSON version
1149 my $rbuf = \$self->{rbuf}; 1191 my $rbuf = \$self->{rbuf};
1150 1192
1151 my $json = $self->{json} ||= JSON->new->utf8; 1193 my $json = $self->{json} ||= JSON->new->utf8;
1152 1194
1153 sub { 1195 sub {
1154 my $ref = $json->incr_parse ($self->{rbuf}); 1196 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1155 1197
1156 if ($ref) { 1198 if ($ref) {
1157 $self->{rbuf} = $json->incr_text; 1199 $self->{rbuf} = $json->incr_text;
1158 $json->incr_text = ""; 1200 $json->incr_text = "";
1159 $cb->($self, $ref); 1201 $cb->($self, $ref);
1160 1202
1161 1 1203 1
1204 } elsif ($@) {
1205 # error case
1206 $json->incr_skip;
1207
1208 $self->{rbuf} = $json->incr_text;
1209 $json->incr_text = "";
1210
1211 $self->_error (&Errno::EBADMSG);
1212
1213 ()
1162 } else { 1214 } else {
1163 $self->{rbuf} = ""; 1215 $self->{rbuf} = "";
1216
1164 () 1217 ()
1165 } 1218 }
1166 } 1219 }
1167}; 1220};
1168 1221
1245Note that AnyEvent::Handle will automatically C<start_read> for you when 1298Note that AnyEvent::Handle will automatically C<start_read> for you when
1246you change the C<on_read> callback or push/unshift a read callback, and it 1299you change the C<on_read> callback or push/unshift a read callback, and it
1247will automatically C<stop_read> for you when neither C<on_read> is set nor 1300will automatically C<stop_read> for you when neither C<on_read> is set nor
1248there are any read requests in the queue. 1301there are any read requests in the queue.
1249 1302
1303These methods will have no effect when in TLS mode (as TLS doesn't support
1304half-duplex connections).
1305
1250=cut 1306=cut
1251 1307
1252sub stop_read { 1308sub stop_read {
1253 my ($self) = @_; 1309 my ($self) = @_;
1254 1310
1255 delete $self->{_rw}; 1311 delete $self->{_rw} unless $self->{tls};
1256} 1312}
1257 1313
1258sub start_read { 1314sub start_read {
1259 my ($self) = @_; 1315 my ($self) = @_;
1260 1316
1261 unless ($self->{_rw} || $self->{_eof}) { 1317 unless ($self->{_rw} || $self->{_eof}) {
1262 Scalar::Util::weaken $self; 1318 Scalar::Util::weaken $self;
1263 1319
1264 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1320 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1265 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1321 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1266 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1322 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1267 1323
1268 if ($len > 0) { 1324 if ($len > 0) {
1269 $self->{_activity} = AnyEvent->now; 1325 $self->{_activity} = AnyEvent->now;
1270 1326
1271 $self->{filter_r} 1327 if ($self->{tls}) {
1272 ? $self->{filter_r}($self, $rbuf) 1328 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1273 : $self->{_in_drain} || $self->_drain_rbuf; 1329
1330 &_dotls ($self);
1331 } else {
1332 $self->_drain_rbuf unless $self->{_in_drain};
1333 }
1274 1334
1275 } elsif (defined $len) { 1335 } elsif (defined $len) {
1276 delete $self->{_rw}; 1336 delete $self->{_rw};
1277 $self->{_eof} = 1; 1337 $self->{_eof} = 1;
1278 $self->_drain_rbuf unless $self->{_in_drain}; 1338 $self->_drain_rbuf unless $self->{_in_drain};
1282 } 1342 }
1283 }); 1343 });
1284 } 1344 }
1285} 1345}
1286 1346
1347# poll the write BIO and send the data if applicable
1287sub _dotls { 1348sub _dotls {
1288 my ($self) = @_; 1349 my ($self) = @_;
1289 1350
1290 my $buf; 1351 my $tmp;
1291 1352
1292 if (length $self->{_tls_wbuf}) { 1353 if (length $self->{_tls_wbuf}) {
1293 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1354 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1294 substr $self->{_tls_wbuf}, 0, $len, ""; 1355 substr $self->{_tls_wbuf}, 0, $tmp, "";
1295 } 1356 }
1296 } 1357 }
1297 1358
1298 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1299 $self->{wbuf} .= $buf;
1300 $self->_drain_wbuf;
1301 }
1302
1303 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1359 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1304 if (length $buf) { 1360 unless (length $tmp) {
1305 $self->{rbuf} .= $buf;
1306 $self->_drain_rbuf unless $self->{_in_drain};
1307 } else {
1308 # let's treat SSL-eof as we treat normal EOF 1361 # let's treat SSL-eof as we treat normal EOF
1362 delete $self->{_rw};
1309 $self->{_eof} = 1; 1363 $self->{_eof} = 1;
1310 $self->_shutdown; 1364 &_freetls;
1311 return;
1312 } 1365 }
1313 }
1314 1366
1367 $self->{_tls_rbuf} .= $tmp;
1368 $self->_drain_rbuf unless $self->{_in_drain};
1369 $self->{tls} or return; # tls session might have gone away in callback
1370 }
1371
1315 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1372 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1316 1373
1317 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1374 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1318 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1375 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1319 return $self->_error ($!, 1); 1376 return $self->_error ($!, 1);
1320 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1377 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1321 return $self->_error (&Errno::EIO, 1); 1378 return $self->_error (&Errno::EIO, 1);
1322 } 1379 }
1323 1380
1324 # all others are fine for our purposes 1381 # all other errors are fine for our purposes
1382 }
1383
1384 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1385 $self->{wbuf} .= $tmp;
1386 $self->_drain_wbuf;
1325 } 1387 }
1326} 1388}
1327 1389
1328=item $handle->starttls ($tls[, $tls_ctx]) 1390=item $handle->starttls ($tls[, $tls_ctx])
1329 1391
1332C<starttls>. 1394C<starttls>.
1333 1395
1334The first argument is the same as the C<tls> constructor argument (either 1396The first argument is the same as the C<tls> constructor argument (either
1335C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1397C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1336 1398
1337The second argument is the optional C<Net::SSLeay::CTX> object that is 1399The second argument is the optional C<AnyEvent::TLS> object that is used
1338used when AnyEvent::Handle has to create its own TLS connection object. 1400when AnyEvent::Handle has to create its own TLS connection object, or
1401a hash reference with C<< key => value >> pairs that will be used to
1402construct a new context.
1339 1403
1340The TLS connection object will end up in C<< $handle->{tls} >> after this 1404The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1341call and can be used or changed to your liking. Note that the handshake 1405context in C<< $handle->{tls_ctx} >> after this call and can be used or
1342might have already started when this function returns. 1406changed to your liking. Note that the handshake might have already started
1407when this function returns.
1408
1409If it an error to start a TLS handshake more than once per
1410AnyEvent::Handle object (this is due to bugs in OpenSSL).
1343 1411
1344=cut 1412=cut
1345 1413
1346sub starttls { 1414sub starttls {
1347 my ($self, $ssl, $ctx) = @_; 1415 my ($self, $ssl, $ctx) = @_;
1348 1416
1349 $self->stoptls; 1417 require Net::SSLeay;
1350 1418
1351 if ($ssl eq "accept") { 1419 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1352 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1420 if $self->{tls};
1353 Net::SSLeay::set_accept_state ($ssl); 1421
1354 } elsif ($ssl eq "connect") { 1422 $ctx ||= $self->{tls_ctx};
1355 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1423
1356 Net::SSLeay::set_connect_state ($ssl); 1424 if ("HASH" eq ref $ctx) {
1425 require AnyEvent::TLS;
1426
1427 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1428 $ctx = new AnyEvent::TLS %$ctx;
1429 }
1357 } 1430
1358 1431 $self->{tls_ctx} = $ctx || TLS_CTX ();
1359 $self->{tls} = $ssl; 1432 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self);
1360 1433
1361 # basically, this is deep magic (because SSL_read should have the same issues) 1434 # basically, this is deep magic (because SSL_read should have the same issues)
1362 # but the openssl maintainers basically said: "trust us, it just works". 1435 # but the openssl maintainers basically said: "trust us, it just works".
1363 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1436 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1364 # and mismaintained ssleay-module doesn't even offer them). 1437 # and mismaintained ssleay-module doesn't even offer them).
1365 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1438 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1439 #
1440 # in short: this is a mess.
1441 #
1442 # note that we do not try to keep the length constant between writes as we are required to do.
1443 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1444 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1445 # have identity issues in that area.
1366 Net::SSLeay::CTX_set_mode ($self->{tls}, 1446# Net::SSLeay::CTX_set_mode ($ssl,
1367 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1447# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1368 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1448# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1449 Net::SSLeay::CTX_set_mode ($ssl, 1|2);
1369 1450
1370 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1451 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1371 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1452 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372 1453
1373 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1454 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1374 1455
1375 $self->{filter_w} = sub { 1456 &_dotls; # need to trigger the initial handshake
1376 $_[0]{_tls_wbuf} .= ${$_[1]}; 1457 $self->start_read; # make sure we actually do read
1377 &_dotls;
1378 };
1379 $self->{filter_r} = sub {
1380 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1381 &_dotls;
1382 };
1383} 1458}
1384 1459
1385=item $handle->stoptls 1460=item $handle->stoptls
1386 1461
1387Destroys the SSL connection, if any. Partial read or write data will be 1462Shuts down the SSL connection - this makes a proper EOF handshake by
1388lost. 1463sending a close notify to the other side, but since OpenSSL doesn't
1464support non-blocking shut downs, it is not possible to re-use the stream
1465afterwards.
1389 1466
1390=cut 1467=cut
1391 1468
1392sub stoptls { 1469sub stoptls {
1393 my ($self) = @_; 1470 my ($self) = @_;
1394 1471
1395 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1472 if ($self->{tls}) {
1473 Net::SSLeay::shutdown ($self->{tls});
1396 1474
1397 delete $self->{_rbio}; 1475 &_dotls;
1398 delete $self->{_wbio}; 1476
1399 delete $self->{_tls_wbuf}; 1477 # we don't give a shit. no, we do, but we can't. no...
1400 delete $self->{filter_r}; 1478 # we, we... have to use openssl :/
1401 delete $self->{filter_w}; 1479 &_freetls;
1480 }
1481}
1482
1483sub _freetls {
1484 my ($self) = @_;
1485
1486 return unless $self->{tls};
1487
1488 $self->{tls_ctx}->_put_session (delete $self->{tls});
1489
1490 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1402} 1491}
1403 1492
1404sub DESTROY { 1493sub DESTROY {
1405 my $self = shift; 1494 my ($self) = @_;
1406 1495
1407 $self->stoptls; 1496 &_freetls;
1408 1497
1409 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1498 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1410 1499
1411 if ($linger && length $self->{wbuf}) { 1500 if ($linger && length $self->{wbuf}) {
1412 my $fh = delete $self->{fh}; 1501 my $fh = delete $self->{fh};
1427 @linger = (); 1516 @linger = ();
1428 }); 1517 });
1429 } 1518 }
1430} 1519}
1431 1520
1521=item $handle->destroy
1522
1523Shuts down the handle object as much as possible - this call ensures that
1524no further callbacks will be invoked and resources will be freed as much
1525as possible. You must not call any methods on the object afterwards.
1526
1527Normally, you can just "forget" any references to an AnyEvent::Handle
1528object and it will simply shut down. This works in fatal error and EOF
1529callbacks, as well as code outside. It does I<NOT> work in a read or write
1530callback, so when you want to destroy the AnyEvent::Handle object from
1531within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1532that case.
1533
1534The handle might still linger in the background and write out remaining
1535data, as specified by the C<linger> option, however.
1536
1537=cut
1538
1539sub destroy {
1540 my ($self) = @_;
1541
1542 $self->DESTROY;
1543 %$self = ();
1544}
1545
1432=item AnyEvent::Handle::TLS_CTX 1546=item AnyEvent::Handle::TLS_CTX
1433 1547
1434This function creates and returns the Net::SSLeay::CTX object used by 1548This function creates and returns the AnyEvent::TLS object used by default
1435default for TLS mode. 1549for TLS mode.
1436 1550
1437The context is created like this: 1551The context is created by calling L<AnyEvent::TLS> without any arguments.
1438
1439 Net::SSLeay::load_error_strings;
1440 Net::SSLeay::SSLeay_add_ssl_algorithms;
1441 Net::SSLeay::randomize;
1442
1443 my $CTX = Net::SSLeay::CTX_new;
1444
1445 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1446 1552
1447=cut 1553=cut
1448 1554
1449our $TLS_CTX; 1555our $TLS_CTX;
1450 1556
1451sub TLS_CTX() { 1557sub TLS_CTX() {
1452 $TLS_CTX || do { 1558 $TLS_CTX ||= do {
1453 require Net::SSLeay; 1559 require AnyEvent::TLS;
1454 1560
1455 Net::SSLeay::load_error_strings (); 1561 new AnyEvent::TLS
1456 Net::SSLeay::SSLeay_add_ssl_algorithms ();
1457 Net::SSLeay::randomize ();
1458
1459 $TLS_CTX = Net::SSLeay::CTX_new ();
1460
1461 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1462
1463 $TLS_CTX
1464 } 1562 }
1465} 1563}
1466 1564
1467=back 1565=back
1566
1567
1568=head1 NONFREQUENTLY ASKED QUESTIONS
1569
1570=over 4
1571
1572=item I C<undef> the AnyEvent::Handle reference inside my callback and
1573still get further invocations!
1574
1575That's because AnyEvent::Handle keeps a reference to itself when handling
1576read or write callbacks.
1577
1578It is only safe to "forget" the reference inside EOF or error callbacks,
1579from within all other callbacks, you need to explicitly call the C<<
1580->destroy >> method.
1581
1582=item I get different callback invocations in TLS mode/Why can't I pause
1583reading?
1584
1585Unlike, say, TCP, TLS connections do not consist of two independent
1586communication channels, one for each direction. Or put differently. The
1587read and write directions are not independent of each other: you cannot
1588write data unless you are also prepared to read, and vice versa.
1589
1590This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1591callback invocations when you are not expecting any read data - the reason
1592is that AnyEvent::Handle always reads in TLS mode.
1593
1594During the connection, you have to make sure that you always have a
1595non-empty read-queue, or an C<on_read> watcher. At the end of the
1596connection (or when you no longer want to use it) you can call the
1597C<destroy> method.
1598
1599=item How do I read data until the other side closes the connection?
1600
1601If you just want to read your data into a perl scalar, the easiest way
1602to achieve this is by setting an C<on_read> callback that does nothing,
1603clearing the C<on_eof> callback and in the C<on_error> callback, the data
1604will be in C<$_[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
1468 1638
1469=head1 SUBCLASSING AnyEvent::Handle 1639=head1 SUBCLASSING AnyEvent::Handle
1470 1640
1471In many cases, you might want to subclass AnyEvent::Handle. 1641In many cases, you might want to subclass AnyEvent::Handle.
1472 1642

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