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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.35 by root, Mon May 26 05:46:35 2008 UTC vs.
Revision 1.134 by root, Fri Jul 3 00:09:04 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util qw(WSAWOULDBLOCK); 7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util (); 8use Scalar::Util ();
9use Carp (); 9use Carp ();
10use Fcntl (); 10use Fcntl ();
11use Errno qw/EAGAIN EINTR/; 11use Errno qw(EAGAIN EINTR);
12 12
13=head1 NAME 13=head1 NAME
14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17=cut 17=cut
18 18
19our $VERSION = '0.04'; 19our $VERSION = 4.45;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
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 => $cb->($self) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called on EOF. 84Set the callback to be called when an end-of-file condition is detected,
85i.e. in the case of a socket, when the other side has closed the
86connection cleanly.
81 87
88For sockets, this just means that the other side has stopped sending data,
89you can still try to write data, and, in fact, one can return from the EOF
90callback and continue writing data, as only the read part has been shut
91down.
92
82While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
83otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
84waiting for data. 95waiting for data.
85 96
86=item on_error => $cb->($self) 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>.
87 99
100=item on_error => $cb->($handle, $fatal, $message)
101
88This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
90or a read error. 104connect or a read error.
91 105
92The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$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
112AnyEvent::Handle tries to find an appropriate error code for you to check
113against, but in some cases (TLS errors), this does not work well. It is
114recommended to always output the C<$message> argument in human-readable
115error messages (it's usually the same as C<"$!">).
116
117Non-fatal errors can be retried by simply returning, but it is recommended
118to simply ignore this parameter and instead abondon the handle object
119when this callback is invoked. Examples of non-fatal errors are timeouts
120C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
94 121
95On callback entrance, the value of C<$!> contains the operating system 122On callback entrance, the value of C<$!> contains the operating system
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 123error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
124C<EPROTO>).
97 125
98While not mandatory, it is I<highly> recommended to set this callback, as 126While not mandatory, it is I<highly> recommended to set this callback, as
99you will not be notified of errors otherwise. The default simply calls 127you will not be notified of errors otherwise. The default simply calls
100die. 128C<croak>.
101 129
102=item on_read => $cb->($self) 130=item on_read => $cb->($handle)
103 131
104This sets the default read callback, which is called when data arrives 132This sets the default read callback, which is called when data arrives
105and no read request is in the queue. 133and no read request is in the queue (unlike read queue callbacks, this
134callback will only be called when at least one octet of data is in the
135read buffer).
106 136
107To access (and remove data from) the read buffer, use the C<< ->rbuf >> 137To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108method or access the C<$self->{rbuf}> member directly. 138method or access the C<$handle->{rbuf}> member directly. Note that you
139must not enlarge or modify the read buffer, you can only remove data at
140the beginning from it.
109 141
110When an EOF condition is detected then AnyEvent::Handle will first try to 142When an EOF condition is detected then AnyEvent::Handle will first try to
111feed all the remaining data to the queued callbacks and C<on_read> before 143feed all the remaining data to the queued callbacks and C<on_read> before
112calling the C<on_eof> callback. If no progress can be made, then a fatal 144calling the C<on_eof> callback. If no progress can be made, then a fatal
113error will be raised (with C<$!> set to C<EPIPE>). 145error will be raised (with C<$!> set to C<EPIPE>).
114 146
115=item on_drain => $cb->() 147=item on_drain => $cb->($handle)
116 148
117This sets the callback that is called when the write buffer becomes empty 149This sets the callback that is called when the write buffer becomes empty
118(or when the callback is set and the buffer is empty already). 150(or when the callback is set and the buffer is empty already).
119 151
120To append to the write buffer, use the C<< ->push_write >> method. 152To append to the write buffer, use the C<< ->push_write >> method.
121 153
154This callback is useful when you don't want to put all of your write data
155into the queue at once, for example, when you want to write the contents
156of some file to the socket you might not want to read the whole file into
157memory and push it into the queue, but instead only read more data from
158the file when the write queue becomes empty.
159
160=item timeout => $fractional_seconds
161
162If non-zero, then this enables an "inactivity" timeout: whenever this many
163seconds pass without a successful read or write on the underlying file
164handle, the C<on_timeout> callback will be invoked (and if that one is
165missing, a non-fatal C<ETIMEDOUT> error will be raised).
166
167Note that timeout processing is also active when you currently do not have
168any outstanding read or write requests: If you plan to keep the connection
169idle then you should disable the timout temporarily or ignore the timeout
170in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
171restart the timeout.
172
173Zero (the default) disables this timeout.
174
175=item on_timeout => $cb->($handle)
176
177Called whenever the inactivity timeout passes. If you return from this
178callback, then the timeout will be reset as if some activity had happened,
179so this condition is not fatal in any way.
180
122=item rbuf_max => <bytes> 181=item rbuf_max => <bytes>
123 182
124If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 183If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125when the read buffer ever (strictly) exceeds this size. This is useful to 184when the read buffer ever (strictly) exceeds this size. This is useful to
126avoid denial-of-service attacks. 185avoid some forms of denial-of-service attacks.
127 186
128For example, a server accepting connections from untrusted sources should 187For example, a server accepting connections from untrusted sources should
129be configured to accept only so-and-so much data that it cannot act on 188be configured to accept only so-and-so much data that it cannot act on
130(for example, when expecting a line, an attacker could send an unlimited 189(for example, when expecting a line, an attacker could send an unlimited
131amount of data without a callback ever being called as long as the line 190amount of data without a callback ever being called as long as the line
132isn't finished). 191isn't finished).
133 192
193=item autocork => <boolean>
194
195When disabled (the default), then C<push_write> will try to immediately
196write the data to the handle, if possible. This avoids having to register
197a write watcher and wait for the next event loop iteration, but can
198be inefficient if you write multiple small chunks (on the wire, this
199disadvantage is usually avoided by your kernel's nagle algorithm, see
200C<no_delay>, but this option can save costly syscalls).
201
202When enabled, then writes will always be queued till the next event loop
203iteration. This is efficient when you do many small writes per iteration,
204but less efficient when you do a single write only per iteration (or when
205the write buffer often is full). It also increases write latency.
206
207=item no_delay => <boolean>
208
209When doing small writes on sockets, your operating system kernel might
210wait a bit for more data before actually sending it out. This is called
211the Nagle algorithm, and usually it is beneficial.
212
213In some situations you want as low a delay as possible, which can be
214accomplishd by setting this option to a true value.
215
216The default is your opertaing system's default behaviour (most likely
217enabled), this option explicitly enables or disables it, if possible.
218
134=item read_size => <bytes> 219=item read_size => <bytes>
135 220
136The default read block size (the amount of bytes this module will try to read 221The default read block size (the amount of bytes this module will
137on each [loop iteration). Default: C<4096>. 222try to read during each loop iteration, which affects memory
223requirements). Default: C<8192>.
138 224
139=item low_water_mark => <bytes> 225=item low_water_mark => <bytes>
140 226
141Sets the amount of bytes (default: C<0>) that make up an "empty" write 227Sets the amount of bytes (default: C<0>) that make up an "empty" write
142buffer: If the write reaches this size or gets even samller it is 228buffer: If the write reaches this size or gets even samller it is
143considered empty. 229considered empty.
144 230
231Sometimes it can be beneficial (for performance reasons) to add data to
232the write buffer before it is fully drained, but this is a rare case, as
233the operating system kernel usually buffers data as well, so the default
234is good in almost all cases.
235
236=item linger => <seconds>
237
238If non-zero (default: C<3600>), then the destructor of the
239AnyEvent::Handle object will check whether there is still outstanding
240write data and will install a watcher that will write this data to the
241socket. No errors will be reported (this mostly matches how the operating
242system treats outstanding data at socket close time).
243
244This will not work for partial TLS data that could not be encoded
245yet. This data will be lost. Calling the C<stoptls> method in time might
246help.
247
248=item peername => $string
249
250A string used to identify the remote site - usually the DNS hostname
251(I<not> IDN!) used to create the connection, rarely the IP address.
252
253Apart from being useful in error messages, this string is also used in TLS
254common name verification (see C<verify_cn> in L<AnyEvent::TLS>).
255
145=item tls => "accept" | "connect" | Net::SSLeay::SSL object 256=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146 257
147When this parameter is given, it enables TLS (SSL) mode, that means it 258When this parameter is given, it enables TLS (SSL) mode, that means
148will start making tls handshake and will transparently encrypt/decrypt 259AnyEvent will start a TLS handshake as soon as the conenction has been
149data. 260established and will transparently encrypt/decrypt data afterwards.
261
262All TLS protocol errors will be signalled as C<EPROTO>, with an
263appropriate error message.
150 264
151TLS mode requires Net::SSLeay to be installed (it will be loaded 265TLS mode requires Net::SSLeay to be installed (it will be loaded
152automatically when you try to create a TLS handle). 266automatically when you try to create a TLS handle): this module doesn't
267have a dependency on that module, so if your module requires it, you have
268to add the dependency yourself.
153 269
154For the TLS server side, use C<accept>, and for the TLS client side of a 270Unlike TCP, TLS has a server and client side: for the TLS server side, use
155connection, use C<connect> mode. 271C<accept>, and for the TLS client side of a connection, use C<connect>
272mode.
156 273
157You can also provide your own TLS connection object, but you have 274You can also provide your own TLS connection object, but you have
158to make sure that you call either C<Net::SSLeay::set_connect_state> 275to make sure that you call either C<Net::SSLeay::set_connect_state>
159or C<Net::SSLeay::set_accept_state> on it before you pass it to 276or C<Net::SSLeay::set_accept_state> on it before you pass it to
160AnyEvent::Handle. 277AnyEvent::Handle. Also, this module will take ownership of this connection
278object.
161 279
280At some future point, AnyEvent::Handle might switch to another TLS
281implementation, then the option to use your own session object will go
282away.
283
284B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
285passing in the wrong integer will lead to certain crash. This most often
286happens when one uses a stylish C<< tls => 1 >> and is surprised about the
287segmentation fault.
288
162See the C<starttls> method if you need to start TLs negotiation later. 289See the C<< ->starttls >> method for when need to start TLS negotiation later.
163 290
164=item tls_ctx => $ssl_ctx 291=item tls_ctx => $anyevent_tls
165 292
166Use the given Net::SSLeay::CTX object to create the new TLS connection 293Use the given C<AnyEvent::TLS> object to create the new TLS connection
167(unless a connection object was specified directly). If this parameter is 294(unless a connection object was specified directly). If this parameter is
168missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 295missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169 296
297Instead of an object, you can also specify a hash reference with C<< key
298=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
299new TLS context object.
300
301=item json => JSON or JSON::XS object
302
303This is the json coder object used by the C<json> read and write types.
304
305If you don't supply it, then AnyEvent::Handle will create and use a
306suitable one (on demand), which will write and expect UTF-8 encoded JSON
307texts.
308
309Note that you are responsible to depend on the JSON module if you want to
310use this functionality, as AnyEvent does not have a dependency itself.
311
170=back 312=back
171 313
172=cut 314=cut
173 315
174sub new { 316sub new {
175 my $class = shift; 317 my $class = shift;
176
177 my $self = bless { @_ }, $class; 318 my $self = bless { @_ }, $class;
178 319
179 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 320 $self->{fh} or Carp::croak "mandatory argument fh is missing";
180 321
181 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 322 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182 323
183 if ($self->{tls}) { 324 $self->{_activity} = AnyEvent->now;
184 require Net::SSLeay; 325 $self->_timeout;
326
327 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
328
185 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 329 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186 } 330 if $self->{tls};
187 331
188 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
189 $self->on_error (delete $self->{on_error}) if $self->{on_error};
190 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 332 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
191 $self->on_read (delete $self->{on_read} ) if $self->{on_read};
192 333
193 $self->start_read; 334 $self->start_read
335 if $self->{on_read};
194 336
195 $self 337 $self->{fh} && $self
196} 338}
197 339
198sub _shutdown { 340sub _shutdown {
199 my ($self) = @_; 341 my ($self) = @_;
200 342
201 delete $self->{rw}; 343 delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
202 delete $self->{ww}; 344 $self->{_eof} = 1; # tell starttls et. al to stop trying
203 delete $self->{fh};
204}
205 345
346 &_freetls;
347}
348
206sub error { 349sub _error {
207 my ($self) = @_; 350 my ($self, $errno, $fatal, $message) = @_;
208 351
209 {
210 local $!;
211 $self->_shutdown; 352 $self->_shutdown
212 } 353 if $fatal;
354
355 $! = $errno;
356 $message ||= "$!";
213 357
214 if ($self->{on_error}) { 358 if ($self->{on_error}) {
215 $self->{on_error}($self); 359 $self->{on_error}($self, $fatal, $message);
216 } else { 360 } elsif ($self->{fh}) {
217 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 361 Carp::croak "AnyEvent::Handle uncaught error: $message";
218 } 362 }
219} 363}
220 364
221=item $fh = $handle->fh 365=item $fh = $handle->fh
222 366
223This method returns the file handle of the L<AnyEvent::Handle> object. 367This method returns the file handle used to create the L<AnyEvent::Handle> object.
224 368
225=cut 369=cut
226 370
227sub fh { $_[0]->{fh} } 371sub fh { $_[0]{fh} }
228 372
229=item $handle->on_error ($cb) 373=item $handle->on_error ($cb)
230 374
231Replace the current C<on_error> callback (see the C<on_error> constructor argument). 375Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232 376
244 388
245sub on_eof { 389sub on_eof {
246 $_[0]{on_eof} = $_[1]; 390 $_[0]{on_eof} = $_[1];
247} 391}
248 392
393=item $handle->on_timeout ($cb)
394
395Replace the current C<on_timeout> callback, or disables the callback (but
396not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
397argument and method.
398
399=cut
400
401sub on_timeout {
402 $_[0]{on_timeout} = $_[1];
403}
404
405=item $handle->autocork ($boolean)
406
407Enables or disables the current autocork behaviour (see C<autocork>
408constructor argument). Changes will only take effect on the next write.
409
410=cut
411
412sub autocork {
413 $_[0]{autocork} = $_[1];
414}
415
416=item $handle->no_delay ($boolean)
417
418Enables or disables the C<no_delay> setting (see constructor argument of
419the same name for details).
420
421=cut
422
423sub no_delay {
424 $_[0]{no_delay} = $_[1];
425
426 eval {
427 local $SIG{__DIE__};
428 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
429 };
430}
431
432#############################################################################
433
434=item $handle->timeout ($seconds)
435
436Configures (or disables) the inactivity timeout.
437
438=cut
439
440sub timeout {
441 my ($self, $timeout) = @_;
442
443 $self->{timeout} = $timeout;
444 $self->_timeout;
445}
446
447# reset the timeout watcher, as neccessary
448# also check for time-outs
449sub _timeout {
450 my ($self) = @_;
451
452 if ($self->{timeout}) {
453 my $NOW = AnyEvent->now;
454
455 # when would the timeout trigger?
456 my $after = $self->{_activity} + $self->{timeout} - $NOW;
457
458 # now or in the past already?
459 if ($after <= 0) {
460 $self->{_activity} = $NOW;
461
462 if ($self->{on_timeout}) {
463 $self->{on_timeout}($self);
464 } else {
465 $self->_error (&Errno::ETIMEDOUT);
466 }
467
468 # callback could have changed timeout value, optimise
469 return unless $self->{timeout};
470
471 # calculate new after
472 $after = $self->{timeout};
473 }
474
475 Scalar::Util::weaken $self;
476 return unless $self; # ->error could have destroyed $self
477
478 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
479 delete $self->{_tw};
480 $self->_timeout;
481 });
482 } else {
483 delete $self->{_tw};
484 }
485}
486
249############################################################################# 487#############################################################################
250 488
251=back 489=back
252 490
253=head2 WRITE QUEUE 491=head2 WRITE QUEUE
274 my ($self, $cb) = @_; 512 my ($self, $cb) = @_;
275 513
276 $self->{on_drain} = $cb; 514 $self->{on_drain} = $cb;
277 515
278 $cb->($self) 516 $cb->($self)
279 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 517 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280} 518}
281 519
282=item $handle->push_write ($data) 520=item $handle->push_write ($data)
283 521
284Queues the given scalar to be written. You can push as much data as you 522Queues the given scalar to be written. You can push as much data as you
288=cut 526=cut
289 527
290sub _drain_wbuf { 528sub _drain_wbuf {
291 my ($self) = @_; 529 my ($self) = @_;
292 530
293 if (!$self->{ww} && length $self->{wbuf}) { 531 if (!$self->{_ww} && length $self->{wbuf}) {
294 532
295 Scalar::Util::weaken $self; 533 Scalar::Util::weaken $self;
296 534
297 my $cb = sub { 535 my $cb = sub {
298 my $len = syswrite $self->{fh}, $self->{wbuf}; 536 my $len = syswrite $self->{fh}, $self->{wbuf};
299 537
300 if ($len >= 0) { 538 if ($len >= 0) {
301 substr $self->{wbuf}, 0, $len, ""; 539 substr $self->{wbuf}, 0, $len, "";
302 540
541 $self->{_activity} = AnyEvent->now;
542
303 $self->{on_drain}($self) 543 $self->{on_drain}($self)
304 if $self->{low_water_mark} >= length $self->{wbuf} 544 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
305 && $self->{on_drain}; 545 && $self->{on_drain};
306 546
307 delete $self->{ww} unless length $self->{wbuf}; 547 delete $self->{_ww} unless length $self->{wbuf};
308 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAWOULDBLOCK) { 548 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
309 $self->error; 549 $self->_error ($!, 1);
310 } 550 }
311 }; 551 };
312 552
313 # try to write data immediately 553 # try to write data immediately
314 $cb->(); 554 $cb->() unless $self->{autocork};
315 555
316 # if still data left in wbuf, we need to poll 556 # if still data left in wbuf, we need to poll
317 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 557 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
318 if length $self->{wbuf}; 558 if length $self->{wbuf};
319 }; 559 };
320} 560}
321 561
322our %WH; 562our %WH;
333 573
334 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 574 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
335 ->($self, @_); 575 ->($self, @_);
336 } 576 }
337 577
338 if ($self->{filter_w}) { 578 if ($self->{tls}) {
339 $self->{filter_w}->($self, \$_[0]); 579 $self->{_tls_wbuf} .= $_[0];
580
581 &_dotls ($self);
340 } else { 582 } else {
341 $self->{wbuf} .= $_[0]; 583 $self->{wbuf} .= $_[0];
342 $self->_drain_wbuf; 584 $self->_drain_wbuf;
343 } 585 }
344} 586}
345 587
346=item $handle->push_write (type => @args) 588=item $handle->push_write (type => @args)
347 589
348=item $handle->unshift_write (type => @args)
349
350Instead of formatting your data yourself, you can also let this module do 590Instead of formatting your data yourself, you can also let this module do
351the job by specifying a type and type-specific arguments. 591the job by specifying a type and type-specific arguments.
352 592
353Predefined types are (if you have ideas for additional types, feel free to 593Predefined types are (if you have ideas for additional types, feel free to
354drop by and tell us): 594drop by and tell us):
358=item netstring => $string 598=item netstring => $string
359 599
360Formats the given value as netstring 600Formats the given value as netstring
361(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 601(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
362 602
363=back
364
365=cut 603=cut
366 604
367register_write_type netstring => sub { 605register_write_type netstring => sub {
368 my ($self, $string) = @_; 606 my ($self, $string) = @_;
369 607
370 sprintf "%d:%s,", (length $string), $string 608 (length $string) . ":$string,"
371}; 609};
372 610
611=item packstring => $format, $data
612
613An octet string prefixed with an encoded length. The encoding C<$format>
614uses the same format as a Perl C<pack> format, but must specify a single
615integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
616optional C<!>, C<< < >> or C<< > >> modifier).
617
618=cut
619
620register_write_type packstring => sub {
621 my ($self, $format, $string) = @_;
622
623 pack "$format/a*", $string
624};
625
626=item json => $array_or_hashref
627
628Encodes the given hash or array reference into a JSON object. Unless you
629provide your own JSON object, this means it will be encoded to JSON text
630in UTF-8.
631
632JSON objects (and arrays) are self-delimiting, so you can write JSON at
633one end of a handle and read them at the other end without using any
634additional framing.
635
636The generated JSON text is guaranteed not to contain any newlines: While
637this module doesn't need delimiters after or between JSON texts to be
638able to read them, many other languages depend on that.
639
640A simple RPC protocol that interoperates easily with others is to send
641JSON arrays (or objects, although arrays are usually the better choice as
642they mimic how function argument passing works) and a newline after each
643JSON text:
644
645 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
646 $handle->push_write ("\012");
647
648An AnyEvent::Handle receiver would simply use the C<json> read type and
649rely on the fact that the newline will be skipped as leading whitespace:
650
651 $handle->push_read (json => sub { my $array = $_[1]; ... });
652
653Other languages could read single lines terminated by a newline and pass
654this line into their JSON decoder of choice.
655
656=cut
657
658register_write_type json => sub {
659 my ($self, $ref) = @_;
660
661 require JSON;
662
663 $self->{json} ? $self->{json}->encode ($ref)
664 : JSON::encode_json ($ref)
665};
666
667=item storable => $reference
668
669Freezes the given reference using L<Storable> and writes it to the
670handle. Uses the C<nfreeze> format.
671
672=cut
673
674register_write_type storable => sub {
675 my ($self, $ref) = @_;
676
677 require Storable;
678
679 pack "w/a*", Storable::nfreeze ($ref)
680};
681
682=back
683
684=item $handle->push_shutdown
685
686Sometimes you know you want to close the socket after writing your data
687before it was actually written. One way to do that is to replace your
688C<on_drain> handler by a callback that shuts down the socket. This method
689is a shorthand for just that, and replaces the C<on_drain> callback with:
690
691 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
692
693This simply shuts down the write side and signals an EOF condition to the
694the peer.
695
696You can rely on the normal read queue and C<on_eof> handling
697afterwards. This is the cleanest way to close a connection.
698
699=cut
700
701sub push_shutdown {
702 $_[0]->{on_drain} = sub { shutdown $_[0]{fh}, 1 };
703}
704
373=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 705=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
374 706
375This function (not method) lets you add your own types to C<push_write>. 707This function (not method) lets you add your own types to C<push_write>.
376Whenever the given C<type> is used, C<push_write> will invoke the code 708Whenever the given C<type> is used, C<push_write> will invoke the code
377reference with the handle object and the remaining arguments. 709reference with the handle object and the remaining arguments.
378 710
397ways, the "simple" way, using only C<on_read> and the "complex" way, using 729ways, the "simple" way, using only C<on_read> and the "complex" way, using
398a queue. 730a queue.
399 731
400In the simple case, you just install an C<on_read> callback and whenever 732In the simple case, you just install an C<on_read> callback and whenever
401new data arrives, it will be called. You can then remove some data (if 733new data arrives, it will be called. You can then remove some data (if
402enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 734enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
403or not. 735leave the data there if you want to accumulate more (e.g. when only a
736partial message has been received so far).
404 737
405In the more complex case, you want to queue multiple callbacks. In this 738In the more complex case, you want to queue multiple callbacks. In this
406case, AnyEvent::Handle will call the first queued callback each time new 739case, AnyEvent::Handle will call the first queued callback each time new
407data arrives and removes it when it has done its job (see C<push_read>, 740data arrives (also the first time it is queued) and removes it when it has
408below). 741done its job (see C<push_read>, below).
409 742
410This way you can, for example, push three line-reads, followed by reading 743This way you can, for example, push three line-reads, followed by reading
411a chunk of data, and AnyEvent::Handle will execute them in order. 744a chunk of data, and AnyEvent::Handle will execute them in order.
412 745
413Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 746Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
414the specified number of bytes which give an XML datagram. 747the specified number of bytes which give an XML datagram.
415 748
416 # in the default state, expect some header bytes 749 # in the default state, expect some header bytes
417 $handle->on_read (sub { 750 $handle->on_read (sub {
418 # some data is here, now queue the length-header-read (4 octets) 751 # some data is here, now queue the length-header-read (4 octets)
419 shift->unshift_read_chunk (4, sub { 752 shift->unshift_read (chunk => 4, sub {
420 # header arrived, decode 753 # header arrived, decode
421 my $len = unpack "N", $_[1]; 754 my $len = unpack "N", $_[1];
422 755
423 # now read the payload 756 # now read the payload
424 shift->unshift_read_chunk ($len, sub { 757 shift->unshift_read (chunk => $len, sub {
425 my $xml = $_[1]; 758 my $xml = $_[1];
426 # handle xml 759 # handle xml
427 }); 760 });
428 }); 761 });
429 }); 762 });
430 763
431Example 2: Implement a client for a protocol that replies either with 764Example 2: Implement a client for a protocol that replies either with "OK"
432"OK" and another line or "ERROR" for one request, and 64 bytes for the 765and another line or "ERROR" for the first request that is sent, and 64
433second request. Due tot he availability of a full queue, we can just 766bytes for the second request. Due to the availability of a queue, we can
434pipeline sending both requests and manipulate the queue as necessary in 767just pipeline sending both requests and manipulate the queue as necessary
435the callbacks: 768in the callbacks.
436 769
437 # request one 770When the first callback is called and sees an "OK" response, it will
771C<unshift> another line-read. This line-read will be queued I<before> the
77264-byte chunk callback.
773
774 # request one, returns either "OK + extra line" or "ERROR"
438 $handle->push_write ("request 1\015\012"); 775 $handle->push_write ("request 1\015\012");
439 776
440 # we expect "ERROR" or "OK" as response, so push a line read 777 # we expect "ERROR" or "OK" as response, so push a line read
441 $handle->push_read_line (sub { 778 $handle->push_read (line => sub {
442 # if we got an "OK", we have to _prepend_ another line, 779 # if we got an "OK", we have to _prepend_ another line,
443 # so it will be read before the second request reads its 64 bytes 780 # so it will be read before the second request reads its 64 bytes
444 # which are already in the queue when this callback is called 781 # which are already in the queue when this callback is called
445 # we don't do this in case we got an error 782 # we don't do this in case we got an error
446 if ($_[1] eq "OK") { 783 if ($_[1] eq "OK") {
447 $_[0]->unshift_read_line (sub { 784 $_[0]->unshift_read (line => sub {
448 my $response = $_[1]; 785 my $response = $_[1];
449 ... 786 ...
450 }); 787 });
451 } 788 }
452 }); 789 });
453 790
454 # request two 791 # request two, simply returns 64 octets
455 $handle->push_write ("request 2\015\012"); 792 $handle->push_write ("request 2\015\012");
456 793
457 # simply read 64 bytes, always 794 # simply read 64 bytes, always
458 $handle->push_read_chunk (64, sub { 795 $handle->push_read (chunk => 64, sub {
459 my $response = $_[1]; 796 my $response = $_[1];
460 ... 797 ...
461 }); 798 });
462 799
463=over 4 800=over 4
464 801
465=cut 802=cut
466 803
467sub _drain_rbuf { 804sub _drain_rbuf {
468 my ($self) = @_; 805 my ($self) = @_;
806
807 local $self->{_in_drain} = 1;
469 808
470 if ( 809 if (
471 defined $self->{rbuf_max} 810 defined $self->{rbuf_max}
472 && $self->{rbuf_max} < length $self->{rbuf} 811 && $self->{rbuf_max} < length $self->{rbuf}
473 ) { 812 ) {
474 $! = &Errno::ENOSPC; return $self->error; 813 $self->_error (&Errno::ENOSPC, 1), return;
475 } 814 }
476 815
477 return if $self->{in_drain}; 816 while () {
478 local $self->{in_drain} = 1; 817 # we need to use a separate tls read buffer, as we must not receive data while
818 # we are draining the buffer, and this can only happen with TLS.
819 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
479 820
480 while (my $len = length $self->{rbuf}) { 821 my $len = length $self->{rbuf};
481 no strict 'refs'; 822
482 if (my $cb = shift @{ $self->{queue} }) { 823 if (my $cb = shift @{ $self->{_queue} }) {
483 unless ($cb->($self)) { 824 unless ($cb->($self)) {
484 if ($self->{eof}) { 825 if ($self->{_eof}) {
485 # no progress can be made (not enough data and no data forthcoming) 826 # no progress can be made (not enough data and no data forthcoming)
486 $! = &Errno::EPIPE; return $self->error; 827 $self->_error (&Errno::EPIPE, 1), return;
487 } 828 }
488 829
489 unshift @{ $self->{queue} }, $cb; 830 unshift @{ $self->{_queue} }, $cb;
490 return; 831 last;
491 } 832 }
492 } elsif ($self->{on_read}) { 833 } elsif ($self->{on_read}) {
834 last unless $len;
835
493 $self->{on_read}($self); 836 $self->{on_read}($self);
494 837
495 if ( 838 if (
496 $self->{eof} # if no further data will arrive
497 && $len == length $self->{rbuf} # and no data has been consumed 839 $len == length $self->{rbuf} # if no data has been consumed
498 && !@{ $self->{queue} } # and the queue is still empty 840 && !@{ $self->{_queue} } # and the queue is still empty
499 && $self->{on_read} # and we still want to read data 841 && $self->{on_read} # but we still have on_read
500 ) { 842 ) {
843 # no further data will arrive
501 # then no progress can be made 844 # so no progress can be made
502 $! = &Errno::EPIPE; return $self->error; 845 $self->_error (&Errno::EPIPE, 1), return
846 if $self->{_eof};
847
848 last; # more data might arrive
503 } 849 }
504 } else { 850 } else {
505 # read side becomes idle 851 # read side becomes idle
506 delete $self->{rw}; 852 delete $self->{_rw} unless $self->{tls};
507 return; 853 last;
508 } 854 }
509 } 855 }
510 856
511 if ($self->{eof}) { 857 if ($self->{_eof}) {
512 $self->_shutdown; 858 if ($self->{on_eof}) {
513 $self->{on_eof}($self) 859 $self->{on_eof}($self)
514 if $self->{on_eof}; 860 } else {
861 $self->_error (0, 1);
862 }
863 }
864
865 # may need to restart read watcher
866 unless ($self->{_rw}) {
867 $self->start_read
868 if $self->{on_read} || @{ $self->{_queue} };
515 } 869 }
516} 870}
517 871
518=item $handle->on_read ($cb) 872=item $handle->on_read ($cb)
519 873
525 879
526sub on_read { 880sub on_read {
527 my ($self, $cb) = @_; 881 my ($self, $cb) = @_;
528 882
529 $self->{on_read} = $cb; 883 $self->{on_read} = $cb;
884 $self->_drain_rbuf if $cb && !$self->{_in_drain};
530} 885}
531 886
532=item $handle->rbuf 887=item $handle->rbuf
533 888
534Returns the read buffer (as a modifiable lvalue). 889Returns the read buffer (as a modifiable lvalue).
535 890
536You can access the read buffer directly as the C<< ->{rbuf} >> member, if 891You can access the read buffer directly as the C<< ->{rbuf} >>
537you want. 892member, if you want. However, the only operation allowed on the
893read buffer (apart from looking at it) is removing data from its
894beginning. Otherwise modifying or appending to it is not allowed and will
895lead to hard-to-track-down bugs.
538 896
539NOTE: The read buffer should only be used or modified if the C<on_read>, 897NOTE: The read buffer should only be used or modified if the C<on_read>,
540C<push_read> or C<unshift_read> methods are used. The other read methods 898C<push_read> or C<unshift_read> methods are used. The other read methods
541automatically manage the read buffer. 899automatically manage the read buffer.
542 900
582 940
583 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 941 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
584 ->($self, $cb, @_); 942 ->($self, $cb, @_);
585 } 943 }
586 944
587 push @{ $self->{queue} }, $cb; 945 push @{ $self->{_queue} }, $cb;
588 $self->_drain_rbuf; 946 $self->_drain_rbuf unless $self->{_in_drain};
589} 947}
590 948
591sub unshift_read { 949sub unshift_read {
592 my $self = shift; 950 my $self = shift;
593 my $cb = pop; 951 my $cb = pop;
598 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 956 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
599 ->($self, $cb, @_); 957 ->($self, $cb, @_);
600 } 958 }
601 959
602 960
603 unshift @{ $self->{queue} }, $cb; 961 unshift @{ $self->{_queue} }, $cb;
604 $self->_drain_rbuf; 962 $self->_drain_rbuf unless $self->{_in_drain};
605} 963}
606 964
607=item $handle->push_read (type => @args, $cb) 965=item $handle->push_read (type => @args, $cb)
608 966
609=item $handle->unshift_read (type => @args, $cb) 967=item $handle->unshift_read (type => @args, $cb)
615Predefined types are (if you have ideas for additional types, feel free to 973Predefined types are (if you have ideas for additional types, feel free to
616drop by and tell us): 974drop by and tell us):
617 975
618=over 4 976=over 4
619 977
620=item chunk => $octets, $cb->($self, $data) 978=item chunk => $octets, $cb->($handle, $data)
621 979
622Invoke the callback only once C<$octets> bytes have been read. Pass the 980Invoke the callback only once C<$octets> bytes have been read. Pass the
623data read to the callback. The callback will never be called with less 981data read to the callback. The callback will never be called with less
624data. 982data.
625 983
639 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 997 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
640 1 998 1
641 } 999 }
642}; 1000};
643 1001
644# compatibility with older API
645sub push_read_chunk {
646 $_[0]->push_read (chunk => $_[1], $_[2]);
647}
648
649sub unshift_read_chunk {
650 $_[0]->unshift_read (chunk => $_[1], $_[2]);
651}
652
653=item line => [$eol, ]$cb->($self, $line, $eol) 1002=item line => [$eol, ]$cb->($handle, $line, $eol)
654 1003
655The callback will be called only once a full line (including the end of 1004The callback will be called only once a full line (including the end of
656line marker, C<$eol>) has been read. This line (excluding the end of line 1005line marker, C<$eol>) has been read. This line (excluding the end of line
657marker) will be passed to the callback as second argument (C<$line>), and 1006marker) will be passed to the callback as second argument (C<$line>), and
658the end of line marker as the third argument (C<$eol>). 1007the end of line marker as the third argument (C<$eol>).
672=cut 1021=cut
673 1022
674register_read_type line => sub { 1023register_read_type line => sub {
675 my ($self, $cb, $eol) = @_; 1024 my ($self, $cb, $eol) = @_;
676 1025
677 $eol = qr|(\015?\012)| if @_ < 3; 1026 if (@_ < 3) {
1027 # this is more than twice as fast as the generic code below
1028 sub {
1029 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1030
1031 $cb->($_[0], $1, $2);
1032 1
1033 }
1034 } else {
678 $eol = quotemeta $eol unless ref $eol; 1035 $eol = quotemeta $eol unless ref $eol;
679 $eol = qr|^(.*?)($eol)|s; 1036 $eol = qr|^(.*?)($eol)|s;
1037
1038 sub {
1039 $_[0]{rbuf} =~ s/$eol// or return;
1040
1041 $cb->($_[0], $1, $2);
1042 1
1043 }
1044 }
1045};
1046
1047=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
1048
1049Makes a regex match against the regex object C<$accept> and returns
1050everything up to and including the match.
1051
1052Example: read a single line terminated by '\n'.
1053
1054 $handle->push_read (regex => qr<\n>, sub { ... });
1055
1056If C<$reject> is given and not undef, then it determines when the data is
1057to be rejected: it is matched against the data when the C<$accept> regex
1058does not match and generates an C<EBADMSG> error when it matches. This is
1059useful to quickly reject wrong data (to avoid waiting for a timeout or a
1060receive buffer overflow).
1061
1062Example: expect a single decimal number followed by whitespace, reject
1063anything else (not the use of an anchor).
1064
1065 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1066
1067If C<$skip> is given and not C<undef>, then it will be matched against
1068the receive buffer when neither C<$accept> nor C<$reject> match,
1069and everything preceding and including the match will be accepted
1070unconditionally. This is useful to skip large amounts of data that you
1071know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1072have to start matching from the beginning. This is purely an optimisation
1073and is usually worth only when you expect more than a few kilobytes.
1074
1075Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1076expect the header to be very large (it isn't in practise, but...), we use
1077a skip regex to skip initial portions. The skip regex is tricky in that
1078it only accepts something not ending in either \015 or \012, as these are
1079required for the accept regex.
1080
1081 $handle->push_read (regex =>
1082 qr<\015\012\015\012>,
1083 undef, # no reject
1084 qr<^.*[^\015\012]>,
1085 sub { ... });
1086
1087=cut
1088
1089register_read_type regex => sub {
1090 my ($self, $cb, $accept, $reject, $skip) = @_;
1091
1092 my $data;
1093 my $rbuf = \$self->{rbuf};
680 1094
681 sub { 1095 sub {
682 $_[0]{rbuf} =~ s/$eol// or return; 1096 # accept
683 1097 if ($$rbuf =~ $accept) {
684 $cb->($_[0], $1, $2); 1098 $data .= substr $$rbuf, 0, $+[0], "";
1099 $cb->($self, $data);
1100 return 1;
1101 }
685 1 1102
1103 # reject
1104 if ($reject && $$rbuf =~ $reject) {
1105 $self->_error (&Errno::EBADMSG);
1106 }
1107
1108 # skip
1109 if ($skip && $$rbuf =~ $skip) {
1110 $data .= substr $$rbuf, 0, $+[0], "";
1111 }
1112
1113 ()
686 } 1114 }
687}; 1115};
688 1116
689# compatibility with older API
690sub push_read_line {
691 my $self = shift;
692 $self->push_read (line => @_);
693}
694
695sub unshift_read_line {
696 my $self = shift;
697 $self->unshift_read (line => @_);
698}
699
700=item netstring => $cb->($string) 1117=item netstring => $cb->($handle, $string)
701 1118
702A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1119A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
703 1120
704Throws an error with C<$!> set to EBADMSG on format violations. 1121Throws an error with C<$!> set to EBADMSG on format violations.
705 1122
709 my ($self, $cb) = @_; 1126 my ($self, $cb) = @_;
710 1127
711 sub { 1128 sub {
712 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1129 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
713 if ($_[0]{rbuf} =~ /[^0-9]/) { 1130 if ($_[0]{rbuf} =~ /[^0-9]/) {
714 $! = &Errno::EBADMSG; 1131 $self->_error (&Errno::EBADMSG);
715 $self->error;
716 } 1132 }
717 return; 1133 return;
718 } 1134 }
719 1135
720 my $len = $1; 1136 my $len = $1;
723 my $string = $_[1]; 1139 my $string = $_[1];
724 $_[0]->unshift_read (chunk => 1, sub { 1140 $_[0]->unshift_read (chunk => 1, sub {
725 if ($_[1] eq ",") { 1141 if ($_[1] eq ",") {
726 $cb->($_[0], $string); 1142 $cb->($_[0], $string);
727 } else { 1143 } else {
728 $! = &Errno::EBADMSG; 1144 $self->_error (&Errno::EBADMSG);
729 $self->error;
730 } 1145 }
731 }); 1146 });
732 }); 1147 });
733 1148
734 1 1149 1
735 } 1150 }
736}; 1151};
737 1152
1153=item packstring => $format, $cb->($handle, $string)
1154
1155An octet string prefixed with an encoded length. The encoding C<$format>
1156uses the same format as a Perl C<pack> format, but must specify a single
1157integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1158optional C<!>, C<< < >> or C<< > >> modifier).
1159
1160For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1161EPP uses a prefix of C<N> (4 octtes).
1162
1163Example: read a block of data prefixed by its length in BER-encoded
1164format (very efficient).
1165
1166 $handle->push_read (packstring => "w", sub {
1167 my ($handle, $data) = @_;
1168 });
1169
1170=cut
1171
1172register_read_type packstring => sub {
1173 my ($self, $cb, $format) = @_;
1174
1175 sub {
1176 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1177 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1178 or return;
1179
1180 $format = length pack $format, $len;
1181
1182 # bypass unshift if we already have the remaining chunk
1183 if ($format + $len <= length $_[0]{rbuf}) {
1184 my $data = substr $_[0]{rbuf}, $format, $len;
1185 substr $_[0]{rbuf}, 0, $format + $len, "";
1186 $cb->($_[0], $data);
1187 } else {
1188 # remove prefix
1189 substr $_[0]{rbuf}, 0, $format, "";
1190
1191 # read remaining chunk
1192 $_[0]->unshift_read (chunk => $len, $cb);
1193 }
1194
1195 1
1196 }
1197};
1198
1199=item json => $cb->($handle, $hash_or_arrayref)
1200
1201Reads a JSON object or array, decodes it and passes it to the
1202callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1203
1204If a C<json> object was passed to the constructor, then that will be used
1205for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1206
1207This read type uses the incremental parser available with JSON version
12082.09 (and JSON::XS version 2.2) and above. You have to provide a
1209dependency on your own: this module will load the JSON module, but
1210AnyEvent does not depend on it itself.
1211
1212Since JSON texts are fully self-delimiting, the C<json> read and write
1213types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1214the C<json> write type description, above, for an actual example.
1215
1216=cut
1217
1218register_read_type json => sub {
1219 my ($self, $cb) = @_;
1220
1221 require JSON;
1222
1223 my $data;
1224 my $rbuf = \$self->{rbuf};
1225
1226 my $json = $self->{json} ||= JSON->new->utf8;
1227
1228 sub {
1229 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1230
1231 if ($ref) {
1232 $self->{rbuf} = $json->incr_text;
1233 $json->incr_text = "";
1234 $cb->($self, $ref);
1235
1236 1
1237 } elsif ($@) {
1238 # error case
1239 $json->incr_skip;
1240
1241 $self->{rbuf} = $json->incr_text;
1242 $json->incr_text = "";
1243
1244 $self->_error (&Errno::EBADMSG);
1245
1246 ()
1247 } else {
1248 $self->{rbuf} = "";
1249
1250 ()
1251 }
1252 }
1253};
1254
1255=item storable => $cb->($handle, $ref)
1256
1257Deserialises a L<Storable> frozen representation as written by the
1258C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1259data).
1260
1261Raises C<EBADMSG> error if the data could not be decoded.
1262
1263=cut
1264
1265register_read_type storable => sub {
1266 my ($self, $cb) = @_;
1267
1268 require Storable;
1269
1270 sub {
1271 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1272 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1273 or return;
1274
1275 my $format = length pack "w", $len;
1276
1277 # bypass unshift if we already have the remaining chunk
1278 if ($format + $len <= length $_[0]{rbuf}) {
1279 my $data = substr $_[0]{rbuf}, $format, $len;
1280 substr $_[0]{rbuf}, 0, $format + $len, "";
1281 $cb->($_[0], Storable::thaw ($data));
1282 } else {
1283 # remove prefix
1284 substr $_[0]{rbuf}, 0, $format, "";
1285
1286 # read remaining chunk
1287 $_[0]->unshift_read (chunk => $len, sub {
1288 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1289 $cb->($_[0], $ref);
1290 } else {
1291 $self->_error (&Errno::EBADMSG);
1292 }
1293 });
1294 }
1295
1296 1
1297 }
1298};
1299
738=back 1300=back
739 1301
740=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1302=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
741 1303
742This function (not method) lets you add your own types to C<push_read>. 1304This function (not method) lets you add your own types to C<push_read>.
743 1305
744Whenever the given C<type> is used, C<push_read> will invoke the code 1306Whenever the given C<type> is used, C<push_read> will invoke the code
745reference with the handle object, the callback and the remaining 1307reference with the handle object, the callback and the remaining
747 1309
748The code reference is supposed to return a callback (usually a closure) 1310The code reference is supposed to return a callback (usually a closure)
749that works as a plain read callback (see C<< ->push_read ($cb) >>). 1311that works as a plain read callback (see C<< ->push_read ($cb) >>).
750 1312
751It should invoke the passed callback when it is done reading (remember to 1313It should invoke the passed callback when it is done reading (remember to
752pass C<$self> as first argument as all other callbacks do that). 1314pass C<$handle> as first argument as all other callbacks do that).
753 1315
754Note that this is a function, and all types registered this way will be 1316Note that this is a function, and all types registered this way will be
755global, so try to use unique names. 1317global, so try to use unique names.
756 1318
757For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1319For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
760=item $handle->stop_read 1322=item $handle->stop_read
761 1323
762=item $handle->start_read 1324=item $handle->start_read
763 1325
764In rare cases you actually do not want to read anything from the 1326In rare cases you actually do not want to read anything from the
765socket. In this case you can call C<stop_read>. Neither C<on_read> no 1327socket. In this case you can call C<stop_read>. Neither C<on_read> nor
766any queued callbacks will be executed then. To start reading again, call 1328any queued callbacks will be executed then. To start reading again, call
767C<start_read>. 1329C<start_read>.
768 1330
1331Note that AnyEvent::Handle will automatically C<start_read> for you when
1332you change the C<on_read> callback or push/unshift a read callback, and it
1333will automatically C<stop_read> for you when neither C<on_read> is set nor
1334there are any read requests in the queue.
1335
1336These methods will have no effect when in TLS mode (as TLS doesn't support
1337half-duplex connections).
1338
769=cut 1339=cut
770 1340
771sub stop_read { 1341sub stop_read {
772 my ($self) = @_; 1342 my ($self) = @_;
773 1343
774 delete $self->{rw}; 1344 delete $self->{_rw} unless $self->{tls};
775} 1345}
776 1346
777sub start_read { 1347sub start_read {
778 my ($self) = @_; 1348 my ($self) = @_;
779 1349
780 unless ($self->{rw} || $self->{eof}) { 1350 unless ($self->{_rw} || $self->{_eof}) {
781 Scalar::Util::weaken $self; 1351 Scalar::Util::weaken $self;
782 1352
783 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1353 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
784 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1354 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
785 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1355 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
786 1356
787 if ($len > 0) { 1357 if ($len > 0) {
788 $self->{filter_r} 1358 $self->{_activity} = AnyEvent->now;
789 ? $self->{filter_r}->($self, $rbuf) 1359
790 : $self->_drain_rbuf; 1360 if ($self->{tls}) {
1361 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1362
1363 &_dotls ($self);
1364 } else {
1365 $self->_drain_rbuf unless $self->{_in_drain};
1366 }
791 1367
792 } elsif (defined $len) { 1368 } elsif (defined $len) {
793 delete $self->{rw}; 1369 delete $self->{_rw};
794 $self->{eof} = 1; 1370 $self->{_eof} = 1;
795 $self->_drain_rbuf; 1371 $self->_drain_rbuf unless $self->{_in_drain};
796 1372
797 } elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAWOULDBLOCK) { 1373 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
798 return $self->error; 1374 return $self->_error ($!, 1);
799 } 1375 }
800 }); 1376 });
801 } 1377 }
802} 1378}
803 1379
1380our $ERROR_SYSCALL;
1381our $ERROR_WANT_READ;
1382our $ERROR_ZERO_RETURN;
1383
1384sub _tls_error {
1385 my ($self, $err) = @_;
1386 warn "$err,$!\n";#d#
1387
1388 return $self->_error ($!, 1)
1389 if $err == Net::SSLeay::ERROR_SYSCALL ();
1390
1391 $self->_error (&Errno::EPROTO, 1,
1392 Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ()));
1393}
1394
1395# poll the write BIO and send the data if applicable
1396# also decode read data if possible
1397# this is basiclaly our TLS state machine
1398# more efficient implementations are possible with openssl,
1399# but not with the buggy and incomplete Net::SSLeay.
804sub _dotls { 1400sub _dotls {
805 my ($self) = @_; 1401 my ($self) = @_;
806 1402
1403 my $tmp;
1404
807 if (length $self->{tls_wbuf}) { 1405 if (length $self->{_tls_wbuf}) {
808 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1406 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
809 substr $self->{tls_wbuf}, 0, $len, ""; 1407 substr $self->{_tls_wbuf}, 0, $tmp, "";
810 } 1408 }
811 }
812 1409
1410 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1411 return $self->_tls_error ($tmp)
1412 if $tmp != $ERROR_WANT_READ
1413 && ($tmp != $ERROR_SYSCALL || $!)
1414 && $tmp != $ERROR_ZERO_RETURN;
1415 }
1416
813 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1417 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1418 unless (length $tmp) {
1419 # let's treat SSL-eof as we treat normal EOF
1420 delete $self->{_rw};
1421 $self->{_eof} = 1;
1422 &_freetls;
1423 }
1424
1425 $self->{_tls_rbuf} .= $tmp;
1426 $self->_drain_rbuf unless $self->{_in_drain};
1427 $self->{tls} or return; # tls session might have gone away in callback
1428 }
1429
1430 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1431 return $self->_tls_error ($tmp)
1432 if $tmp != $ERROR_WANT_READ
1433 && ($tmp != $ERROR_SYSCALL || $!)
1434 && $tmp != $ERROR_ZERO_RETURN;
1435
1436 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
814 $self->{wbuf} .= $buf; 1437 $self->{wbuf} .= $tmp;
815 $self->_drain_wbuf; 1438 $self->_drain_wbuf;
816 }
817
818 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
819 $self->{rbuf} .= $buf;
820 $self->_drain_rbuf;
821 }
822
823 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
824
825 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
826 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
827 $self->error;
828 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
829 $! = &Errno::EIO;
830 $self->error;
831 }
832
833 # all others are fine for our purposes
834 } 1439 }
835} 1440}
836 1441
837=item $handle->starttls ($tls[, $tls_ctx]) 1442=item $handle->starttls ($tls[, $tls_ctx])
838 1443
841C<starttls>. 1446C<starttls>.
842 1447
843The first argument is the same as the C<tls> constructor argument (either 1448The first argument is the same as the C<tls> constructor argument (either
844C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1449C<"connect">, C<"accept"> or an existing Net::SSLeay object).
845 1450
846The second argument is the optional C<Net::SSLeay::CTX> object that is 1451The second argument is the optional C<AnyEvent::TLS> object that is used
847used when AnyEvent::Handle has to create its own TLS connection object. 1452when AnyEvent::Handle has to create its own TLS connection object, or
1453a hash reference with C<< key => value >> pairs that will be used to
1454construct a new context.
848 1455
849=cut 1456The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1457context in C<< $handle->{tls_ctx} >> after this call and can be used or
1458changed to your liking. Note that the handshake might have already started
1459when this function returns.
850 1460
851# TODO: maybe document... 1461If it an error to start a TLS handshake more than once per
1462AnyEvent::Handle object (this is due to bugs in OpenSSL).
1463
1464=cut
1465
852sub starttls { 1466sub starttls {
853 my ($self, $ssl, $ctx) = @_; 1467 my ($self, $ssl, $ctx) = @_;
854 1468
855 $self->stoptls; 1469 require Net::SSLeay;
856 1470
857 if ($ssl eq "accept") { 1471 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
858 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1472 if $self->{tls};
859 Net::SSLeay::set_accept_state ($ssl); 1473
860 } elsif ($ssl eq "connect") { 1474 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
861 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1475 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
862 Net::SSLeay::set_connect_state ($ssl); 1476 $ERROR_ZERO_RETURN = Net::SSLeay::ERROR_ZERO_RETURN ();
1477
1478 $ctx ||= $self->{tls_ctx};
1479
1480 if ("HASH" eq ref $ctx) {
1481 require AnyEvent::TLS;
1482
1483 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1484 $ctx = new AnyEvent::TLS %$ctx;
1485 }
863 } 1486
864 1487 $self->{tls_ctx} = $ctx || TLS_CTX ();
865 $self->{tls} = $ssl; 1488 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername});
866 1489
867 # basically, this is deep magic (because SSL_read should have the same issues) 1490 # basically, this is deep magic (because SSL_read should have the same issues)
868 # but the openssl maintainers basically said: "trust us, it just works". 1491 # but the openssl maintainers basically said: "trust us, it just works".
869 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1492 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
870 # and mismaintained ssleay-module doesn't even offer them). 1493 # and mismaintained ssleay-module doesn't even offer them).
871 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1494 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1495 #
1496 # in short: this is a mess.
1497 #
1498 # note that we do not try to keep the length constant between writes as we are required to do.
1499 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1500 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1501 # have identity issues in that area.
872 Net::SSLeay::CTX_set_mode ($self->{tls}, 1502# Net::SSLeay::CTX_set_mode ($ssl,
873 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1503# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
874 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1504# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1505 Net::SSLeay::CTX_set_mode ($ssl, 1|2);
875 1506
876 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1507 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
877 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1508 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
878 1509
879 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1510 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
880 1511
881 $self->{filter_w} = sub { 1512 &_dotls; # need to trigger the initial handshake
882 $_[0]{tls_wbuf} .= ${$_[1]}; 1513 $self->start_read; # make sure we actually do read
883 &_dotls;
884 };
885 $self->{filter_r} = sub {
886 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
887 &_dotls;
888 };
889} 1514}
890 1515
891=item $handle->stoptls 1516=item $handle->stoptls
892 1517
893Destroys the SSL connection, if any. Partial read or write data will be 1518Shuts down the SSL connection - this makes a proper EOF handshake by
894lost. 1519sending a close notify to the other side, but since OpenSSL doesn't
1520support non-blocking shut downs, it is not possible to re-use the stream
1521afterwards.
895 1522
896=cut 1523=cut
897 1524
898sub stoptls { 1525sub stoptls {
899 my ($self) = @_; 1526 my ($self) = @_;
900 1527
901 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1528 if ($self->{tls}) {
902 delete $self->{tls_rbio}; 1529 Net::SSLeay::shutdown ($self->{tls});
903 delete $self->{tls_wbio}; 1530
904 delete $self->{tls_wbuf}; 1531 &_dotls;
905 delete $self->{filter_r}; 1532
906 delete $self->{filter_w}; 1533 # we don't give a shit. no, we do, but we can't. no...
1534 # we, we... have to use openssl :/
1535 &_freetls;
1536 }
1537}
1538
1539sub _freetls {
1540 my ($self) = @_;
1541
1542 return unless $self->{tls};
1543
1544 $self->{tls_ctx}->_put_session (delete $self->{tls});
1545
1546 delete @$self{qw(_rbio _wbio _tls_wbuf)};
907} 1547}
908 1548
909sub DESTROY { 1549sub DESTROY {
910 my $self = shift; 1550 my ($self) = @_;
911 1551
912 $self->stoptls; 1552 &_freetls;
1553
1554 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1555
1556 if ($linger && length $self->{wbuf}) {
1557 my $fh = delete $self->{fh};
1558 my $wbuf = delete $self->{wbuf};
1559
1560 my @linger;
1561
1562 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1563 my $len = syswrite $fh, $wbuf, length $wbuf;
1564
1565 if ($len > 0) {
1566 substr $wbuf, 0, $len, "";
1567 } else {
1568 @linger = (); # end
1569 }
1570 });
1571 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1572 @linger = ();
1573 });
1574 }
1575}
1576
1577=item $handle->destroy
1578
1579Shuts down the handle object as much as possible - this call ensures that
1580no further callbacks will be invoked and resources will be freed as much
1581as possible. You must not call any methods on the object afterwards.
1582
1583Normally, you can just "forget" any references to an AnyEvent::Handle
1584object and it will simply shut down. This works in fatal error and EOF
1585callbacks, as well as code outside. It does I<NOT> work in a read or write
1586callback, so when you want to destroy the AnyEvent::Handle object from
1587within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1588that case.
1589
1590The handle might still linger in the background and write out remaining
1591data, as specified by the C<linger> option, however.
1592
1593=cut
1594
1595sub destroy {
1596 my ($self) = @_;
1597
1598 $self->DESTROY;
1599 %$self = ();
913} 1600}
914 1601
915=item AnyEvent::Handle::TLS_CTX 1602=item AnyEvent::Handle::TLS_CTX
916 1603
917This function creates and returns the Net::SSLeay::CTX object used by 1604This function creates and returns the AnyEvent::TLS object used by default
918default for TLS mode. 1605for TLS mode.
919 1606
920The context is created like this: 1607The context is created by calling L<AnyEvent::TLS> without any arguments.
921
922 Net::SSLeay::load_error_strings;
923 Net::SSLeay::SSLeay_add_ssl_algorithms;
924 Net::SSLeay::randomize;
925
926 my $CTX = Net::SSLeay::CTX_new;
927
928 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
929 1608
930=cut 1609=cut
931 1610
932our $TLS_CTX; 1611our $TLS_CTX;
933 1612
934sub TLS_CTX() { 1613sub TLS_CTX() {
935 $TLS_CTX || do { 1614 $TLS_CTX ||= do {
936 require Net::SSLeay; 1615 require AnyEvent::TLS;
937 1616
938 Net::SSLeay::load_error_strings (); 1617 new AnyEvent::TLS
939 Net::SSLeay::SSLeay_add_ssl_algorithms ();
940 Net::SSLeay::randomize ();
941
942 $TLS_CTX = Net::SSLeay::CTX_new ();
943
944 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
945
946 $TLS_CTX
947 } 1618 }
948} 1619}
949 1620
950=back 1621=back
951 1622
1623
1624=head1 NONFREQUENTLY ASKED QUESTIONS
1625
1626=over 4
1627
1628=item I C<undef> the AnyEvent::Handle reference inside my callback and
1629still get further invocations!
1630
1631That's because AnyEvent::Handle keeps a reference to itself when handling
1632read or write callbacks.
1633
1634It is only safe to "forget" the reference inside EOF or error callbacks,
1635from within all other callbacks, you need to explicitly call the C<<
1636->destroy >> method.
1637
1638=item I get different callback invocations in TLS mode/Why can't I pause
1639reading?
1640
1641Unlike, say, TCP, TLS connections do not consist of two independent
1642communication channels, one for each direction. Or put differently. The
1643read and write directions are not independent of each other: you cannot
1644write data unless you are also prepared to read, and vice versa.
1645
1646This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1647callback invocations when you are not expecting any read data - the reason
1648is that AnyEvent::Handle always reads in TLS mode.
1649
1650During the connection, you have to make sure that you always have a
1651non-empty read-queue, or an C<on_read> watcher. At the end of the
1652connection (or when you no longer want to use it) you can call the
1653C<destroy> method.
1654
1655=item How do I read data until the other side closes the connection?
1656
1657If you just want to read your data into a perl scalar, the easiest way
1658to achieve this is by setting an C<on_read> callback that does nothing,
1659clearing the C<on_eof> callback and in the C<on_error> callback, the data
1660will be in C<$_[0]{rbuf}>:
1661
1662 $handle->on_read (sub { });
1663 $handle->on_eof (undef);
1664 $handle->on_error (sub {
1665 my $data = delete $_[0]{rbuf};
1666 undef $handle;
1667 });
1668
1669The reason to use C<on_error> is that TCP connections, due to latencies
1670and packets loss, might get closed quite violently with an error, when in
1671fact, all data has been received.
1672
1673It is usually better to use acknowledgements when transferring data,
1674to make sure the other side hasn't just died and you got the data
1675intact. This is also one reason why so many internet protocols have an
1676explicit QUIT command.
1677
1678=item I don't want to destroy the handle too early - how do I wait until
1679all data has been written?
1680
1681After writing your last bits of data, set the C<on_drain> callback
1682and destroy the handle in there - with the default setting of
1683C<low_water_mark> this will be called precisely when all data has been
1684written to the socket:
1685
1686 $handle->push_write (...);
1687 $handle->on_drain (sub {
1688 warn "all data submitted to the kernel\n";
1689 undef $handle;
1690 });
1691
1692=back
1693
1694
1695=head1 SUBCLASSING AnyEvent::Handle
1696
1697In many cases, you might want to subclass AnyEvent::Handle.
1698
1699To make this easier, a given version of AnyEvent::Handle uses these
1700conventions:
1701
1702=over 4
1703
1704=item * all constructor arguments become object members.
1705
1706At least initially, when you pass a C<tls>-argument to the constructor it
1707will end up in C<< $handle->{tls} >>. Those members might be changed or
1708mutated later on (for example C<tls> will hold the TLS connection object).
1709
1710=item * other object member names are prefixed with an C<_>.
1711
1712All object members not explicitly documented (internal use) are prefixed
1713with an underscore character, so the remaining non-C<_>-namespace is free
1714for use for subclasses.
1715
1716=item * all members not documented here and not prefixed with an underscore
1717are free to use in subclasses.
1718
1719Of course, new versions of AnyEvent::Handle may introduce more "public"
1720member variables, but thats just life, at least it is documented.
1721
1722=back
1723
952=head1 AUTHOR 1724=head1 AUTHOR
953 1725
954Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1726Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
955 1727
956=cut 1728=cut

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