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Revision 1.31 by root, Sun May 25 00:08:49 2008 UTC vs.
Revision 1.95 by root, Thu Oct 2 06:42:39 2008 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 (); 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 $VERSION = 4.3;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
59argument. 62argument.
60 63
64=head2 SIGPIPE is not handled by this module
65
66SIGPIPE is not handled by this module, so one of the practical
67requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} =
68'IGNORE'>). At least, this is highly recommend in a networked program: If
69you use AnyEvent::Handle in a filter program (like sort), exiting on
70SIGPIPE is probably the right thing to do.
71
61=head1 METHODS 72=head1 METHODS
62 73
63=over 4 74=over 4
64 75
65=item B<new (%args)> 76=item B<new (%args)>
70 81
71=item fh => $filehandle [MANDATORY] 82=item fh => $filehandle [MANDATORY]
72 83
73The filehandle this L<AnyEvent::Handle> object will operate on. 84The filehandle this L<AnyEvent::Handle> object will operate on.
74 85
75NOTE: The filehandle will be set to non-blocking (using 86NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 87C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
88that mode.
77 89
78=item on_eof => $cb->($self) 90=item on_eof => $cb->($handle)
79 91
80Set the callback to be called on EOF. 92Set the callback to be called when an end-of-file condition is detected,
93i.e. in the case of a socket, when the other side has closed the
94connection cleanly.
81 95
96For sockets, this just means that the other side has stopped sending data,
97you can still try to write data, and, in fact, one can return from the eof
98callback and continue writing data, as only the read part has been shut
99down.
100
82While not mandatory, it is highly recommended to set an eof callback, 101While 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 102otherwise you might end up with a closed socket while you are still
84waiting for data. 103waiting for data.
85 104
105If an EOF condition has been detected but no C<on_eof> callback has been
106set, then a fatal error will be raised with C<$!> set to <0>.
107
86=item on_error => $cb->($self) 108=item on_error => $cb->($handle, $fatal)
87 109
88This is the fatal error callback, that is called when, well, a fatal error 110This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 111occured, such as not being able to resolve the hostname, failure to
90or a read error. 112connect or a read error.
91 113
92The object will not be in a usable state when this callback has been 114Some errors are fatal (which is indicated by C<$fatal> being true). On
93called. 115fatal errors the handle object will be shut down and will not be usable
116(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
117errors are an EOF condition with active (but unsatisifable) read watchers
118(C<EPIPE>) or I/O errors.
119
120Non-fatal errors can be retried by simply returning, but it is recommended
121to simply ignore this parameter and instead abondon the handle object
122when this callback is invoked. Examples of non-fatal errors are timeouts
123C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
94 124
95On callback entrance, the value of C<$!> contains the operating system 125On callback entrance, the value of C<$!> contains the operating system
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 126error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
97 127
98While not mandatory, it is I<highly> recommended to set this callback, as 128While not mandatory, it is I<highly> recommended to set this callback, as
99you will not be notified of errors otherwise. The default simply calls 129you will not be notified of errors otherwise. The default simply calls
100die. 130C<croak>.
101 131
102=item on_read => $cb->($self) 132=item on_read => $cb->($handle)
103 133
104This sets the default read callback, which is called when data arrives 134This sets the default read callback, which is called when data arrives
105and no read request is in the queue. 135and no read request is in the queue (unlike read queue callbacks, this
136callback will only be called when at least one octet of data is in the
137read buffer).
106 138
107To access (and remove data from) the read buffer, use the C<< ->rbuf >> 139To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108method or access the C<$self->{rbuf}> member directly. 140method or access the C<$handle->{rbuf}> member directly.
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
145=item tls => "accept" | "connect" | Net::SSLeay::SSL object 248=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146 249
147When this parameter is given, it enables TLS (SSL) mode, that means it 250When this parameter is given, it enables TLS (SSL) mode, that means
148will start making tls handshake and will transparently encrypt/decrypt 251AnyEvent will start a TLS handshake as soon as the conenction has been
149data. 252established and will transparently encrypt/decrypt data afterwards.
150 253
151TLS mode requires Net::SSLeay to be installed (it will be loaded 254TLS mode requires Net::SSLeay to be installed (it will be loaded
152automatically 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.
153 258
154For 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
155connection, use C<connect> mode. 260C<accept>, and for the TLS client side of a connection, use C<connect>
261mode.
156 262
157You can also provide your own TLS connection object, but you have 263You can also provide your own TLS connection object, but you have
158to 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>
159or 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
160AnyEvent::Handle. 266AnyEvent::Handle.
161 267
162See the C<starttls> method if you need to start TLs negotiation later. 268See the C<< ->starttls >> method for when need to start TLS negotiation later.
163 269
164=item tls_ctx => $ssl_ctx 270=item tls_ctx => $ssl_ctx
165 271
166Use the given Net::SSLeay::CTX object to create the new TLS connection 272Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
167(unless a connection object was specified directly). If this parameter is 273(unless a connection object was specified directly). If this parameter is
168missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 274missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169 275
276=item json => JSON or JSON::XS object
277
278This is the json coder object used by the C<json> read and write types.
279
280If you don't supply it, then AnyEvent::Handle will create and use a
281suitable one (on demand), which will write and expect UTF-8 encoded JSON
282texts.
283
284Note that you are responsible to depend on the JSON module if you want to
285use this functionality, as AnyEvent does not have a dependency itself.
286
170=back 287=back
171 288
172=cut 289=cut
173 290
174sub new { 291sub new {
178 295
179 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 296 $self->{fh} or Carp::croak "mandatory argument fh is missing";
180 297
181 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 298 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182 299
183 if ($self->{tls}) {
184 require Net::SSLeay;
185 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 300 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186 } 301 if $self->{tls};
187 302
188 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 303 $self->{_activity} = AnyEvent->now;
189 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 304 $self->_timeout;
305
190 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 306 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
191 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 307 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
192 308
193 $self->start_read; 309 $self->start_read
310 if $self->{on_read};
194 311
195 $self 312 $self
196} 313}
197 314
198sub _shutdown { 315sub _shutdown {
199 my ($self) = @_; 316 my ($self) = @_;
200 317
318 delete $self->{_tw};
201 delete $self->{rw}; 319 delete $self->{_rw};
202 delete $self->{ww}; 320 delete $self->{_ww};
203 delete $self->{fh}; 321 delete $self->{fh};
204}
205 322
323 &_freetls;
324
325 delete $self->{on_read};
326 delete $self->{_queue};
327}
328
206sub error { 329sub _error {
207 my ($self) = @_; 330 my ($self, $errno, $fatal) = @_;
208 331
209 {
210 local $!;
211 $self->_shutdown; 332 $self->_shutdown
212 } 333 if $fatal;
334
335 $! = $errno;
213 336
214 if ($self->{on_error}) { 337 if ($self->{on_error}) {
215 $self->{on_error}($self); 338 $self->{on_error}($self, $fatal);
216 } else { 339 } else {
217 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 340 Carp::croak "AnyEvent::Handle uncaught error: $!";
218 } 341 }
219} 342}
220 343
221=item $fh = $handle->fh 344=item $fh = $handle->fh
222 345
223This method returns the file handle of the L<AnyEvent::Handle> object. 346This method returns the file handle used to create the L<AnyEvent::Handle> object.
224 347
225=cut 348=cut
226 349
227sub fh { $_[0]->{fh} } 350sub fh { $_[0]{fh} }
228 351
229=item $handle->on_error ($cb) 352=item $handle->on_error ($cb)
230 353
231Replace the current C<on_error> callback (see the C<on_error> constructor argument). 354Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232 355
244 367
245sub on_eof { 368sub on_eof {
246 $_[0]{on_eof} = $_[1]; 369 $_[0]{on_eof} = $_[1];
247} 370}
248 371
372=item $handle->on_timeout ($cb)
373
374Replace the current C<on_timeout> callback, or disables the callback (but
375not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
376argument and method.
377
378=cut
379
380sub on_timeout {
381 $_[0]{on_timeout} = $_[1];
382}
383
384=item $handle->autocork ($boolean)
385
386Enables or disables the current autocork behaviour (see C<autocork>
387constructor argument).
388
389=cut
390
391=item $handle->no_delay ($boolean)
392
393Enables or disables the C<no_delay> setting (see constructor argument of
394the same name for details).
395
396=cut
397
398sub no_delay {
399 $_[0]{no_delay} = $_[1];
400
401 eval {
402 local $SIG{__DIE__};
403 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
404 };
405}
406
407#############################################################################
408
409=item $handle->timeout ($seconds)
410
411Configures (or disables) the inactivity timeout.
412
413=cut
414
415sub timeout {
416 my ($self, $timeout) = @_;
417
418 $self->{timeout} = $timeout;
419 $self->_timeout;
420}
421
422# reset the timeout watcher, as neccessary
423# also check for time-outs
424sub _timeout {
425 my ($self) = @_;
426
427 if ($self->{timeout}) {
428 my $NOW = AnyEvent->now;
429
430 # when would the timeout trigger?
431 my $after = $self->{_activity} + $self->{timeout} - $NOW;
432
433 # now or in the past already?
434 if ($after <= 0) {
435 $self->{_activity} = $NOW;
436
437 if ($self->{on_timeout}) {
438 $self->{on_timeout}($self);
439 } else {
440 $self->_error (&Errno::ETIMEDOUT);
441 }
442
443 # callback could have changed timeout value, optimise
444 return unless $self->{timeout};
445
446 # calculate new after
447 $after = $self->{timeout};
448 }
449
450 Scalar::Util::weaken $self;
451 return unless $self; # ->error could have destroyed $self
452
453 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
454 delete $self->{_tw};
455 $self->_timeout;
456 });
457 } else {
458 delete $self->{_tw};
459 }
460}
461
249############################################################################# 462#############################################################################
250 463
251=back 464=back
252 465
253=head2 WRITE QUEUE 466=head2 WRITE QUEUE
274 my ($self, $cb) = @_; 487 my ($self, $cb) = @_;
275 488
276 $self->{on_drain} = $cb; 489 $self->{on_drain} = $cb;
277 490
278 $cb->($self) 491 $cb->($self)
279 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 492 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280} 493}
281 494
282=item $handle->push_write ($data) 495=item $handle->push_write ($data)
283 496
284Queues the given scalar to be written. You can push as much data as you 497Queues the given scalar to be written. You can push as much data as you
288=cut 501=cut
289 502
290sub _drain_wbuf { 503sub _drain_wbuf {
291 my ($self) = @_; 504 my ($self) = @_;
292 505
293 if (!$self->{ww} && length $self->{wbuf}) { 506 if (!$self->{_ww} && length $self->{wbuf}) {
507
294 Scalar::Util::weaken $self; 508 Scalar::Util::weaken $self;
509
295 my $cb = sub { 510 my $cb = sub {
296 my $len = syswrite $self->{fh}, $self->{wbuf}; 511 my $len = syswrite $self->{fh}, $self->{wbuf};
297 512
298 if ($len >= 0) { 513 if ($len >= 0) {
299 substr $self->{wbuf}, 0, $len, ""; 514 substr $self->{wbuf}, 0, $len, "";
300 515
516 $self->{_activity} = AnyEvent->now;
517
301 $self->{on_drain}($self) 518 $self->{on_drain}($self)
302 if $self->{low_water_mark} >= length $self->{wbuf} 519 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303 && $self->{on_drain}; 520 && $self->{on_drain};
304 521
305 delete $self->{ww} unless length $self->{wbuf}; 522 delete $self->{_ww} unless length $self->{wbuf};
306 } elsif ($! != EAGAIN && $! != EINTR) { 523 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307 $self->error; 524 $self->_error ($!, 1);
308 } 525 }
309 }; 526 };
310 527
528 # try to write data immediately
529 $cb->() unless $self->{autocork};
530
531 # if still data left in wbuf, we need to poll
311 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 532 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
312 533 if length $self->{wbuf};
313 $cb->($self);
314 }; 534 };
315} 535}
316 536
317our %WH; 537our %WH;
318 538
328 548
329 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 549 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
330 ->($self, @_); 550 ->($self, @_);
331 } 551 }
332 552
333 if ($self->{filter_w}) { 553 if ($self->{tls}) {
334 $self->{filter_w}->($self, \$_[0]); 554 $self->{_tls_wbuf} .= $_[0];
555 &_dotls ($self);
335 } else { 556 } else {
336 $self->{wbuf} .= $_[0]; 557 $self->{wbuf} .= $_[0];
337 $self->_drain_wbuf; 558 $self->_drain_wbuf;
338 } 559 }
339} 560}
340 561
341=item $handle->push_write (type => @args) 562=item $handle->push_write (type => @args)
342 563
343=item $handle->unshift_write (type => @args)
344
345Instead of formatting your data yourself, you can also let this module do 564Instead of formatting your data yourself, you can also let this module do
346the job by specifying a type and type-specific arguments. 565the job by specifying a type and type-specific arguments.
347 566
348Predefined types are (if you have ideas for additional types, feel free to 567Predefined types are (if you have ideas for additional types, feel free to
349drop by and tell us): 568drop by and tell us):
353=item netstring => $string 572=item netstring => $string
354 573
355Formats the given value as netstring 574Formats the given value as netstring
356(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 575(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357 576
358=back
359
360=cut 577=cut
361 578
362register_write_type netstring => sub { 579register_write_type netstring => sub {
363 my ($self, $string) = @_; 580 my ($self, $string) = @_;
364 581
365 sprintf "%d:%s,", (length $string), $string 582 sprintf "%d:%s,", (length $string), $string
366}; 583};
367 584
585=item packstring => $format, $data
586
587An octet string prefixed with an encoded length. The encoding C<$format>
588uses the same format as a Perl C<pack> format, but must specify a single
589integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
590optional C<!>, C<< < >> or C<< > >> modifier).
591
592=cut
593
594register_write_type packstring => sub {
595 my ($self, $format, $string) = @_;
596
597 pack "$format/a*", $string
598};
599
600=item json => $array_or_hashref
601
602Encodes the given hash or array reference into a JSON object. Unless you
603provide your own JSON object, this means it will be encoded to JSON text
604in UTF-8.
605
606JSON objects (and arrays) are self-delimiting, so you can write JSON at
607one end of a handle and read them at the other end without using any
608additional framing.
609
610The generated JSON text is guaranteed not to contain any newlines: While
611this module doesn't need delimiters after or between JSON texts to be
612able to read them, many other languages depend on that.
613
614A simple RPC protocol that interoperates easily with others is to send
615JSON arrays (or objects, although arrays are usually the better choice as
616they mimic how function argument passing works) and a newline after each
617JSON text:
618
619 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
620 $handle->push_write ("\012");
621
622An AnyEvent::Handle receiver would simply use the C<json> read type and
623rely on the fact that the newline will be skipped as leading whitespace:
624
625 $handle->push_read (json => sub { my $array = $_[1]; ... });
626
627Other languages could read single lines terminated by a newline and pass
628this line into their JSON decoder of choice.
629
630=cut
631
632register_write_type json => sub {
633 my ($self, $ref) = @_;
634
635 require JSON;
636
637 $self->{json} ? $self->{json}->encode ($ref)
638 : JSON::encode_json ($ref)
639};
640
641=item storable => $reference
642
643Freezes the given reference using L<Storable> and writes it to the
644handle. Uses the C<nfreeze> format.
645
646=cut
647
648register_write_type storable => sub {
649 my ($self, $ref) = @_;
650
651 require Storable;
652
653 pack "w/a*", Storable::nfreeze ($ref)
654};
655
656=back
657
368=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 658=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
369 659
370This function (not method) lets you add your own types to C<push_write>. 660This function (not method) lets you add your own types to C<push_write>.
371Whenever the given C<type> is used, C<push_write> will invoke the code 661Whenever the given C<type> is used, C<push_write> will invoke the code
372reference with the handle object and the remaining arguments. 662reference with the handle object and the remaining arguments.
373 663
392ways, the "simple" way, using only C<on_read> and the "complex" way, using 682ways, the "simple" way, using only C<on_read> and the "complex" way, using
393a queue. 683a queue.
394 684
395In the simple case, you just install an C<on_read> callback and whenever 685In the simple case, you just install an C<on_read> callback and whenever
396new data arrives, it will be called. You can then remove some data (if 686new data arrives, it will be called. You can then remove some data (if
397enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 687enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
398or not. 688leave the data there if you want to accumulate more (e.g. when only a
689partial message has been received so far).
399 690
400In the more complex case, you want to queue multiple callbacks. In this 691In the more complex case, you want to queue multiple callbacks. In this
401case, AnyEvent::Handle will call the first queued callback each time new 692case, AnyEvent::Handle will call the first queued callback each time new
402data arrives and removes it when it has done its job (see C<push_read>, 693data arrives (also the first time it is queued) and removes it when it has
403below). 694done its job (see C<push_read>, below).
404 695
405This way you can, for example, push three line-reads, followed by reading 696This way you can, for example, push three line-reads, followed by reading
406a chunk of data, and AnyEvent::Handle will execute them in order. 697a chunk of data, and AnyEvent::Handle will execute them in order.
407 698
408Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 699Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409the specified number of bytes which give an XML datagram. 700the specified number of bytes which give an XML datagram.
410 701
411 # in the default state, expect some header bytes 702 # in the default state, expect some header bytes
412 $handle->on_read (sub { 703 $handle->on_read (sub {
413 # some data is here, now queue the length-header-read (4 octets) 704 # some data is here, now queue the length-header-read (4 octets)
414 shift->unshift_read_chunk (4, sub { 705 shift->unshift_read (chunk => 4, sub {
415 # header arrived, decode 706 # header arrived, decode
416 my $len = unpack "N", $_[1]; 707 my $len = unpack "N", $_[1];
417 708
418 # now read the payload 709 # now read the payload
419 shift->unshift_read_chunk ($len, sub { 710 shift->unshift_read (chunk => $len, sub {
420 my $xml = $_[1]; 711 my $xml = $_[1];
421 # handle xml 712 # handle xml
422 }); 713 });
423 }); 714 });
424 }); 715 });
425 716
426Example 2: Implement a client for a protocol that replies either with 717Example 2: Implement a client for a protocol that replies either with "OK"
427"OK" and another line or "ERROR" for one request, and 64 bytes for the 718and another line or "ERROR" for the first request that is sent, and 64
428second request. Due tot he availability of a full queue, we can just 719bytes for the second request. Due to the availability of a queue, we can
429pipeline sending both requests and manipulate the queue as necessary in 720just pipeline sending both requests and manipulate the queue as necessary
430the callbacks: 721in the callbacks.
431 722
432 # request one 723When the first callback is called and sees an "OK" response, it will
724C<unshift> another line-read. This line-read will be queued I<before> the
72564-byte chunk callback.
726
727 # request one, returns either "OK + extra line" or "ERROR"
433 $handle->push_write ("request 1\015\012"); 728 $handle->push_write ("request 1\015\012");
434 729
435 # we expect "ERROR" or "OK" as response, so push a line read 730 # we expect "ERROR" or "OK" as response, so push a line read
436 $handle->push_read_line (sub { 731 $handle->push_read (line => sub {
437 # if we got an "OK", we have to _prepend_ another line, 732 # if we got an "OK", we have to _prepend_ another line,
438 # so it will be read before the second request reads its 64 bytes 733 # so it will be read before the second request reads its 64 bytes
439 # which are already in the queue when this callback is called 734 # which are already in the queue when this callback is called
440 # we don't do this in case we got an error 735 # we don't do this in case we got an error
441 if ($_[1] eq "OK") { 736 if ($_[1] eq "OK") {
442 $_[0]->unshift_read_line (sub { 737 $_[0]->unshift_read (line => sub {
443 my $response = $_[1]; 738 my $response = $_[1];
444 ... 739 ...
445 }); 740 });
446 } 741 }
447 }); 742 });
448 743
449 # request two 744 # request two, simply returns 64 octets
450 $handle->push_write ("request 2\015\012"); 745 $handle->push_write ("request 2\015\012");
451 746
452 # simply read 64 bytes, always 747 # simply read 64 bytes, always
453 $handle->push_read_chunk (64, sub { 748 $handle->push_read (chunk => 64, sub {
454 my $response = $_[1]; 749 my $response = $_[1];
455 ... 750 ...
456 }); 751 });
457 752
458=over 4 753=over 4
459 754
460=cut 755=cut
461 756
462sub _drain_rbuf { 757sub _drain_rbuf {
463 my ($self) = @_; 758 my ($self) = @_;
759
760 local $self->{_in_drain} = 1;
464 761
465 if ( 762 if (
466 defined $self->{rbuf_max} 763 defined $self->{rbuf_max}
467 && $self->{rbuf_max} < length $self->{rbuf} 764 && $self->{rbuf_max} < length $self->{rbuf}
468 ) { 765 ) {
469 $! = &Errno::ENOSPC; return $self->error; 766 $self->_error (&Errno::ENOSPC, 1), return;
470 } 767 }
471 768
472 return if $self->{in_drain}; 769 while () {
473 local $self->{in_drain} = 1;
474
475 while (my $len = length $self->{rbuf}) { 770 my $len = length $self->{rbuf};
476 no strict 'refs'; 771
477 if (my $cb = shift @{ $self->{queue} }) { 772 if (my $cb = shift @{ $self->{_queue} }) {
478 unless ($cb->($self)) { 773 unless ($cb->($self)) {
479 if ($self->{eof}) { 774 if ($self->{_eof}) {
480 # no progress can be made (not enough data and no data forthcoming) 775 # no progress can be made (not enough data and no data forthcoming)
481 $! = &Errno::EPIPE; return $self->error; 776 $self->_error (&Errno::EPIPE, 1), return;
482 } 777 }
483 778
484 unshift @{ $self->{queue} }, $cb; 779 unshift @{ $self->{_queue} }, $cb;
485 return; 780 last;
486 } 781 }
487 } elsif ($self->{on_read}) { 782 } elsif ($self->{on_read}) {
783 last unless $len;
784
488 $self->{on_read}($self); 785 $self->{on_read}($self);
489 786
490 if ( 787 if (
491 $self->{eof} # if no further data will arrive
492 && $len == length $self->{rbuf} # and no data has been consumed 788 $len == length $self->{rbuf} # if no data has been consumed
493 && !@{ $self->{queue} } # and the queue is still empty 789 && !@{ $self->{_queue} } # and the queue is still empty
494 && $self->{on_read} # and we still want to read data 790 && $self->{on_read} # but we still have on_read
495 ) { 791 ) {
792 # no further data will arrive
496 # then no progress can be made 793 # so no progress can be made
497 $! = &Errno::EPIPE; return $self->error; 794 $self->_error (&Errno::EPIPE, 1), return
795 if $self->{_eof};
796
797 last; # more data might arrive
498 } 798 }
499 } else { 799 } else {
500 # read side becomes idle 800 # read side becomes idle
501 delete $self->{rw}; 801 delete $self->{_rw} unless $self->{tls};
502 return; 802 last;
503 } 803 }
504 } 804 }
505 805
506 if ($self->{eof}) { 806 if ($self->{_eof}) {
507 $self->_shutdown; 807 if ($self->{on_eof}) {
508 $self->{on_eof}($self) 808 $self->{on_eof}($self)
509 if $self->{on_eof}; 809 } else {
810 $self->_error (0, 1);
811 }
812 }
813
814 # may need to restart read watcher
815 unless ($self->{_rw}) {
816 $self->start_read
817 if $self->{on_read} || @{ $self->{_queue} };
510 } 818 }
511} 819}
512 820
513=item $handle->on_read ($cb) 821=item $handle->on_read ($cb)
514 822
520 828
521sub on_read { 829sub on_read {
522 my ($self, $cb) = @_; 830 my ($self, $cb) = @_;
523 831
524 $self->{on_read} = $cb; 832 $self->{on_read} = $cb;
833 $self->_drain_rbuf if $cb && !$self->{_in_drain};
525} 834}
526 835
527=item $handle->rbuf 836=item $handle->rbuf
528 837
529Returns the read buffer (as a modifiable lvalue). 838Returns the read buffer (as a modifiable lvalue).
577 886
578 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 887 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
579 ->($self, $cb, @_); 888 ->($self, $cb, @_);
580 } 889 }
581 890
582 push @{ $self->{queue} }, $cb; 891 push @{ $self->{_queue} }, $cb;
583 $self->_drain_rbuf; 892 $self->_drain_rbuf unless $self->{_in_drain};
584} 893}
585 894
586sub unshift_read { 895sub unshift_read {
587 my $self = shift; 896 my $self = shift;
588 my $cb = pop; 897 my $cb = pop;
593 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 902 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
594 ->($self, $cb, @_); 903 ->($self, $cb, @_);
595 } 904 }
596 905
597 906
598 unshift @{ $self->{queue} }, $cb; 907 unshift @{ $self->{_queue} }, $cb;
599 $self->_drain_rbuf; 908 $self->_drain_rbuf unless $self->{_in_drain};
600} 909}
601 910
602=item $handle->push_read (type => @args, $cb) 911=item $handle->push_read (type => @args, $cb)
603 912
604=item $handle->unshift_read (type => @args, $cb) 913=item $handle->unshift_read (type => @args, $cb)
610Predefined types are (if you have ideas for additional types, feel free to 919Predefined types are (if you have ideas for additional types, feel free to
611drop by and tell us): 920drop by and tell us):
612 921
613=over 4 922=over 4
614 923
615=item chunk => $octets, $cb->($self, $data) 924=item chunk => $octets, $cb->($handle, $data)
616 925
617Invoke the callback only once C<$octets> bytes have been read. Pass the 926Invoke the callback only once C<$octets> bytes have been read. Pass the
618data read to the callback. The callback will never be called with less 927data read to the callback. The callback will never be called with less
619data. 928data.
620 929
634 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 943 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635 1 944 1
636 } 945 }
637}; 946};
638 947
639# compatibility with older API
640sub push_read_chunk {
641 $_[0]->push_read (chunk => $_[1], $_[2]);
642}
643
644sub unshift_read_chunk {
645 $_[0]->unshift_read (chunk => $_[1], $_[2]);
646}
647
648=item line => [$eol, ]$cb->($self, $line, $eol) 948=item line => [$eol, ]$cb->($handle, $line, $eol)
649 949
650The callback will be called only once a full line (including the end of 950The callback will be called only once a full line (including the end of
651line marker, C<$eol>) has been read. This line (excluding the end of line 951line marker, C<$eol>) has been read. This line (excluding the end of line
652marker) will be passed to the callback as second argument (C<$line>), and 952marker) will be passed to the callback as second argument (C<$line>), and
653the end of line marker as the third argument (C<$eol>). 953the end of line marker as the third argument (C<$eol>).
667=cut 967=cut
668 968
669register_read_type line => sub { 969register_read_type line => sub {
670 my ($self, $cb, $eol) = @_; 970 my ($self, $cb, $eol) = @_;
671 971
672 $eol = qr|(\015?\012)| if @_ < 3; 972 if (@_ < 3) {
973 # this is more than twice as fast as the generic code below
974 sub {
975 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
976
977 $cb->($_[0], $1, $2);
978 1
979 }
980 } else {
673 $eol = quotemeta $eol unless ref $eol; 981 $eol = quotemeta $eol unless ref $eol;
674 $eol = qr|^(.*?)($eol)|s; 982 $eol = qr|^(.*?)($eol)|s;
983
984 sub {
985 $_[0]{rbuf} =~ s/$eol// or return;
986
987 $cb->($_[0], $1, $2);
988 1
989 }
990 }
991};
992
993=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
994
995Makes a regex match against the regex object C<$accept> and returns
996everything up to and including the match.
997
998Example: read a single line terminated by '\n'.
999
1000 $handle->push_read (regex => qr<\n>, sub { ... });
1001
1002If C<$reject> is given and not undef, then it determines when the data is
1003to be rejected: it is matched against the data when the C<$accept> regex
1004does not match and generates an C<EBADMSG> error when it matches. This is
1005useful to quickly reject wrong data (to avoid waiting for a timeout or a
1006receive buffer overflow).
1007
1008Example: expect a single decimal number followed by whitespace, reject
1009anything else (not the use of an anchor).
1010
1011 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1012
1013If C<$skip> is given and not C<undef>, then it will be matched against
1014the receive buffer when neither C<$accept> nor C<$reject> match,
1015and everything preceding and including the match will be accepted
1016unconditionally. This is useful to skip large amounts of data that you
1017know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1018have to start matching from the beginning. This is purely an optimisation
1019and is usually worth only when you expect more than a few kilobytes.
1020
1021Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1022expect the header to be very large (it isn't in practise, but...), we use
1023a skip regex to skip initial portions. The skip regex is tricky in that
1024it only accepts something not ending in either \015 or \012, as these are
1025required for the accept regex.
1026
1027 $handle->push_read (regex =>
1028 qr<\015\012\015\012>,
1029 undef, # no reject
1030 qr<^.*[^\015\012]>,
1031 sub { ... });
1032
1033=cut
1034
1035register_read_type regex => sub {
1036 my ($self, $cb, $accept, $reject, $skip) = @_;
1037
1038 my $data;
1039 my $rbuf = \$self->{rbuf};
675 1040
676 sub { 1041 sub {
677 $_[0]{rbuf} =~ s/$eol// or return; 1042 # accept
678 1043 if ($$rbuf =~ $accept) {
679 $cb->($_[0], $1, $2); 1044 $data .= substr $$rbuf, 0, $+[0], "";
1045 $cb->($self, $data);
1046 return 1;
1047 }
680 1 1048
1049 # reject
1050 if ($reject && $$rbuf =~ $reject) {
1051 $self->_error (&Errno::EBADMSG);
1052 }
1053
1054 # skip
1055 if ($skip && $$rbuf =~ $skip) {
1056 $data .= substr $$rbuf, 0, $+[0], "";
1057 }
1058
1059 ()
681 } 1060 }
682}; 1061};
683 1062
684# compatibility with older API
685sub push_read_line {
686 my $self = shift;
687 $self->push_read (line => @_);
688}
689
690sub unshift_read_line {
691 my $self = shift;
692 $self->unshift_read (line => @_);
693}
694
695=item netstring => $cb->($string) 1063=item netstring => $cb->($handle, $string)
696 1064
697A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1065A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698 1066
699Throws an error with C<$!> set to EBADMSG on format violations. 1067Throws an error with C<$!> set to EBADMSG on format violations.
700 1068
704 my ($self, $cb) = @_; 1072 my ($self, $cb) = @_;
705 1073
706 sub { 1074 sub {
707 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1075 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708 if ($_[0]{rbuf} =~ /[^0-9]/) { 1076 if ($_[0]{rbuf} =~ /[^0-9]/) {
709 $! = &Errno::EBADMSG; 1077 $self->_error (&Errno::EBADMSG);
710 $self->error;
711 } 1078 }
712 return; 1079 return;
713 } 1080 }
714 1081
715 my $len = $1; 1082 my $len = $1;
718 my $string = $_[1]; 1085 my $string = $_[1];
719 $_[0]->unshift_read (chunk => 1, sub { 1086 $_[0]->unshift_read (chunk => 1, sub {
720 if ($_[1] eq ",") { 1087 if ($_[1] eq ",") {
721 $cb->($_[0], $string); 1088 $cb->($_[0], $string);
722 } else { 1089 } else {
723 $! = &Errno::EBADMSG; 1090 $self->_error (&Errno::EBADMSG);
724 $self->error;
725 } 1091 }
726 }); 1092 });
727 }); 1093 });
728 1094
729 1 1095 1
730 } 1096 }
731}; 1097};
732 1098
1099=item packstring => $format, $cb->($handle, $string)
1100
1101An octet string prefixed with an encoded length. The encoding C<$format>
1102uses the same format as a Perl C<pack> format, but must specify a single
1103integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1104optional C<!>, C<< < >> or C<< > >> modifier).
1105
1106DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
1107
1108Example: read a block of data prefixed by its length in BER-encoded
1109format (very efficient).
1110
1111 $handle->push_read (packstring => "w", sub {
1112 my ($handle, $data) = @_;
1113 });
1114
1115=cut
1116
1117register_read_type packstring => sub {
1118 my ($self, $cb, $format) = @_;
1119
1120 sub {
1121 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1122 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1123 or return;
1124
1125 $format = length pack $format, $len;
1126
1127 # bypass unshift if we already have the remaining chunk
1128 if ($format + $len <= length $_[0]{rbuf}) {
1129 my $data = substr $_[0]{rbuf}, $format, $len;
1130 substr $_[0]{rbuf}, 0, $format + $len, "";
1131 $cb->($_[0], $data);
1132 } else {
1133 # remove prefix
1134 substr $_[0]{rbuf}, 0, $format, "";
1135
1136 # read remaining chunk
1137 $_[0]->unshift_read (chunk => $len, $cb);
1138 }
1139
1140 1
1141 }
1142};
1143
1144=item json => $cb->($handle, $hash_or_arrayref)
1145
1146Reads a JSON object or array, decodes it and passes it to the callback.
1147
1148If a C<json> object was passed to the constructor, then that will be used
1149for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1150
1151This read type uses the incremental parser available with JSON version
11522.09 (and JSON::XS version 2.2) and above. You have to provide a
1153dependency on your own: this module will load the JSON module, but
1154AnyEvent does not depend on it itself.
1155
1156Since JSON texts are fully self-delimiting, the C<json> read and write
1157types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1158the C<json> write type description, above, for an actual example.
1159
1160=cut
1161
1162register_read_type json => sub {
1163 my ($self, $cb) = @_;
1164
1165 require JSON;
1166
1167 my $data;
1168 my $rbuf = \$self->{rbuf};
1169
1170 my $json = $self->{json} ||= JSON->new->utf8;
1171
1172 sub {
1173 my $ref = $json->incr_parse ($self->{rbuf});
1174
1175 if ($ref) {
1176 $self->{rbuf} = $json->incr_text;
1177 $json->incr_text = "";
1178 $cb->($self, $ref);
1179
1180 1
1181 } else {
1182 $self->{rbuf} = "";
1183 ()
1184 }
1185 }
1186};
1187
1188=item storable => $cb->($handle, $ref)
1189
1190Deserialises a L<Storable> frozen representation as written by the
1191C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1192data).
1193
1194Raises C<EBADMSG> error if the data could not be decoded.
1195
1196=cut
1197
1198register_read_type storable => sub {
1199 my ($self, $cb) = @_;
1200
1201 require Storable;
1202
1203 sub {
1204 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1205 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1206 or return;
1207
1208 my $format = length pack "w", $len;
1209
1210 # bypass unshift if we already have the remaining chunk
1211 if ($format + $len <= length $_[0]{rbuf}) {
1212 my $data = substr $_[0]{rbuf}, $format, $len;
1213 substr $_[0]{rbuf}, 0, $format + $len, "";
1214 $cb->($_[0], Storable::thaw ($data));
1215 } else {
1216 # remove prefix
1217 substr $_[0]{rbuf}, 0, $format, "";
1218
1219 # read remaining chunk
1220 $_[0]->unshift_read (chunk => $len, sub {
1221 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1222 $cb->($_[0], $ref);
1223 } else {
1224 $self->_error (&Errno::EBADMSG);
1225 }
1226 });
1227 }
1228
1229 1
1230 }
1231};
1232
733=back 1233=back
734 1234
735=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1235=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
736 1236
737This function (not method) lets you add your own types to C<push_read>. 1237This function (not method) lets you add your own types to C<push_read>.
738 1238
739Whenever the given C<type> is used, C<push_read> will invoke the code 1239Whenever the given C<type> is used, C<push_read> will invoke the code
740reference with the handle object, the callback and the remaining 1240reference with the handle object, the callback and the remaining
742 1242
743The code reference is supposed to return a callback (usually a closure) 1243The code reference is supposed to return a callback (usually a closure)
744that works as a plain read callback (see C<< ->push_read ($cb) >>). 1244that works as a plain read callback (see C<< ->push_read ($cb) >>).
745 1245
746It should invoke the passed callback when it is done reading (remember to 1246It should invoke the passed callback when it is done reading (remember to
747pass C<$self> as first argument as all other callbacks do that). 1247pass C<$handle> as first argument as all other callbacks do that).
748 1248
749Note that this is a function, and all types registered this way will be 1249Note that this is a function, and all types registered this way will be
750global, so try to use unique names. 1250global, so try to use unique names.
751 1251
752For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1252For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
755=item $handle->stop_read 1255=item $handle->stop_read
756 1256
757=item $handle->start_read 1257=item $handle->start_read
758 1258
759In rare cases you actually do not want to read anything from the 1259In rare cases you actually do not want to read anything from the
760socket. In this case you can call C<stop_read>. Neither C<on_read> no 1260socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761any queued callbacks will be executed then. To start reading again, call 1261any queued callbacks will be executed then. To start reading again, call
762C<start_read>. 1262C<start_read>.
763 1263
1264Note that AnyEvent::Handle will automatically C<start_read> for you when
1265you change the C<on_read> callback or push/unshift a read callback, and it
1266will automatically C<stop_read> for you when neither C<on_read> is set nor
1267there are any read requests in the queue.
1268
1269These methods will have no effect when in TLS mode (as TLS doesn't support
1270half-duplex connections).
1271
764=cut 1272=cut
765 1273
766sub stop_read { 1274sub stop_read {
767 my ($self) = @_; 1275 my ($self) = @_;
768 1276
769 delete $self->{rw}; 1277 delete $self->{_rw} unless $self->{tls};
770} 1278}
771 1279
772sub start_read { 1280sub start_read {
773 my ($self) = @_; 1281 my ($self) = @_;
774 1282
775 unless ($self->{rw} || $self->{eof}) { 1283 unless ($self->{_rw} || $self->{_eof}) {
776 Scalar::Util::weaken $self; 1284 Scalar::Util::weaken $self;
777 1285
778 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1286 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
779 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1287 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1288 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781 1289
782 if ($len > 0) { 1290 if ($len > 0) {
783 $self->{filter_r} 1291 $self->{_activity} = AnyEvent->now;
784 ? $self->{filter_r}->($self, $rbuf) 1292
785 : $self->_drain_rbuf; 1293 if ($self->{tls}) {
1294 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1295 &_dotls ($self);
1296 } else {
1297 $self->_drain_rbuf unless $self->{_in_drain};
1298 }
786 1299
787 } elsif (defined $len) { 1300 } elsif (defined $len) {
788 delete $self->{rw}; 1301 delete $self->{_rw};
789 $self->{eof} = 1; 1302 $self->{_eof} = 1;
790 $self->_drain_rbuf; 1303 $self->_drain_rbuf unless $self->{_in_drain};
791 1304
792 } elsif ($! != EAGAIN && $! != EINTR) { 1305 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793 return $self->error; 1306 return $self->_error ($!, 1);
794 } 1307 }
795 }); 1308 });
796 } 1309 }
797} 1310}
798 1311
799sub _dotls { 1312sub _dotls {
800 my ($self) = @_; 1313 my ($self) = @_;
801 1314
1315 my $buf;
1316
802 if (length $self->{tls_wbuf}) { 1317 if (length $self->{_tls_wbuf}) {
803 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1318 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804 substr $self->{tls_wbuf}, 0, $len, ""; 1319 substr $self->{_tls_wbuf}, 0, $len, "";
805 } 1320 }
806 } 1321 }
807 1322
1323 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
1324 unless (length $buf) {
1325 # let's treat SSL-eof as we treat normal EOF
1326 delete $self->{_rw};
1327 $self->{_eof} = 1;
1328 &_freetls;
1329 }
1330
1331 $self->{rbuf} .= $buf;
1332 $self->_drain_rbuf unless $self->{_in_drain};
1333 $self->{tls} or return; # tls session might have gone away in callback
1334 }
1335
1336 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1337
1338 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1339 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1340 return $self->_error ($!, 1);
1341 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1342 return $self->_error (&Errno::EIO, 1);
1343 }
1344
1345 # all others are fine for our purposes
1346 }
1347
808 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1348 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809 $self->{wbuf} .= $buf; 1349 $self->{wbuf} .= $buf;
810 $self->_drain_wbuf; 1350 $self->_drain_wbuf;
811 }
812
813 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
814 $self->{rbuf} .= $buf;
815 $self->_drain_rbuf;
816 }
817
818 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
819
820 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
821 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
822 $self->error;
823 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
824 $! = &Errno::EIO;
825 $self->error;
826 }
827
828 # all others are fine for our purposes
829 } 1351 }
830} 1352}
831 1353
832=item $handle->starttls ($tls[, $tls_ctx]) 1354=item $handle->starttls ($tls[, $tls_ctx])
833 1355
839C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1361C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840 1362
841The second argument is the optional C<Net::SSLeay::CTX> object that is 1363The second argument is the optional C<Net::SSLeay::CTX> object that is
842used when AnyEvent::Handle has to create its own TLS connection object. 1364used when AnyEvent::Handle has to create its own TLS connection object.
843 1365
844=cut 1366The TLS connection object will end up in C<< $handle->{tls} >> after this
1367call and can be used or changed to your liking. Note that the handshake
1368might have already started when this function returns.
845 1369
846# TODO: maybe document... 1370If it an error to start a TLS handshake more than once per
1371AnyEvent::Handle object (this is due to bugs in OpenSSL).
1372
1373=cut
1374
847sub starttls { 1375sub starttls {
848 my ($self, $ssl, $ctx) = @_; 1376 my ($self, $ssl, $ctx) = @_;
849 1377
850 $self->stoptls; 1378 require Net::SSLeay;
851 1379
1380 Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"
1381 if $self->{tls};
1382
852 if ($ssl eq "accept") { 1383 if ($ssl eq "accept") {
853 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1384 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
854 Net::SSLeay::set_accept_state ($ssl); 1385 Net::SSLeay::set_accept_state ($ssl);
855 } elsif ($ssl eq "connect") { 1386 } elsif ($ssl eq "connect") {
856 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1387 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
862 # basically, this is deep magic (because SSL_read should have the same issues) 1393 # basically, this is deep magic (because SSL_read should have the same issues)
863 # but the openssl maintainers basically said: "trust us, it just works". 1394 # but the openssl maintainers basically said: "trust us, it just works".
864 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1395 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
865 # and mismaintained ssleay-module doesn't even offer them). 1396 # and mismaintained ssleay-module doesn't even offer them).
866 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1397 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1398 #
1399 # in short: this is a mess.
1400 #
1401 # note that we do not try to keep the length constant between writes as we are required to do.
1402 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1403 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1404 # have identity issues in that area.
867 Net::SSLeay::CTX_set_mode ($self->{tls}, 1405 Net::SSLeay::CTX_set_mode ($self->{tls},
868 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1406 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1407 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
870 1408
871 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1409 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1410 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873 1411
874 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1412 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
875 1413
876 $self->{filter_w} = sub { 1414 &_dotls; # need to trigger the initial handshake
877 $_[0]{tls_wbuf} .= ${$_[1]}; 1415 $self->start_read; # make sure we actually do read
878 &_dotls;
879 };
880 $self->{filter_r} = sub {
881 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882 &_dotls;
883 };
884} 1416}
885 1417
886=item $handle->stoptls 1418=item $handle->stoptls
887 1419
888Destroys the SSL connection, if any. Partial read or write data will be 1420Shuts down the SSL connection - this makes a proper EOF handshake by
889lost. 1421sending a close notify to the other side, but since OpenSSL doesn't
1422support non-blocking shut downs, it is not possible to re-use the stream
1423afterwards.
890 1424
891=cut 1425=cut
892 1426
893sub stoptls { 1427sub stoptls {
894 my ($self) = @_; 1428 my ($self) = @_;
895 1429
1430 if ($self->{tls}) {
1431 Net::SSLeay::shutdown ($self->{tls});
1432
1433 &_dotls;
1434
1435 # we don't give a shit. no, we do, but we can't. no...
1436 # we, we... have to use openssl :/
1437 &_freetls;
1438 }
1439}
1440
1441sub _freetls {
1442 my ($self) = @_;
1443
1444 return unless $self->{tls};
1445
896 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1446 Net::SSLeay::free (delete $self->{tls});
897 delete $self->{tls_rbio}; 1447
898 delete $self->{tls_wbio}; 1448 delete @$self{qw(_rbio _wbio _tls_wbuf)};
899 delete $self->{tls_wbuf};
900 delete $self->{filter_r};
901 delete $self->{filter_w};
902} 1449}
903 1450
904sub DESTROY { 1451sub DESTROY {
905 my $self = shift; 1452 my $self = shift;
906 1453
907 $self->stoptls; 1454 &_freetls;
1455
1456 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1457
1458 if ($linger && length $self->{wbuf}) {
1459 my $fh = delete $self->{fh};
1460 my $wbuf = delete $self->{wbuf};
1461
1462 my @linger;
1463
1464 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1465 my $len = syswrite $fh, $wbuf, length $wbuf;
1466
1467 if ($len > 0) {
1468 substr $wbuf, 0, $len, "";
1469 } else {
1470 @linger = (); # end
1471 }
1472 });
1473 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1474 @linger = ();
1475 });
1476 }
908} 1477}
909 1478
910=item AnyEvent::Handle::TLS_CTX 1479=item AnyEvent::Handle::TLS_CTX
911 1480
912This function creates and returns the Net::SSLeay::CTX object used by 1481This function creates and returns the Net::SSLeay::CTX object used by
942 } 1511 }
943} 1512}
944 1513
945=back 1514=back
946 1515
1516
1517=head1 NONFREQUENTLY ASKED QUESTIONS
1518
1519=over 4
1520
1521=item How do I read data until the other side closes the connection?
1522
1523If you just want to read your data into a perl scalar, the easiest way to achieve this is
1524by setting an C<on_read> callback that does nothing, clearing the C<on_eof> callback
1525and in the C<on_error> callback, the data will be in C<$_[0]{rbuf}>:
1526
1527 $handle->on_read (sub { });
1528 $handle->on_eof (undef);
1529 $handle->on_error (sub {
1530 my $data = delete $_[0]{rbuf};
1531 undef $handle;
1532 });
1533
1534The reason to use C<on_error> is that TCP connections, due to latencies
1535and packets loss, might get closed quite violently with an error, when in
1536fact, all data has been received.
1537
1538It is usually better to use acknowledgements when transfering data,
1539to make sure the other side hasn't just died and you got the data
1540intact. This is also one reason why so many internet protocols have an
1541explicit QUIT command.
1542
1543
1544=item I don't want to destroy the handle too early - how do I wait until all data has been sent?
1545
1546After writing your last bits of data, set the C<on_drain> callback
1547and destroy the handle in there - with the default setting of
1548C<low_water_mark> this will be called precisely when all data has been
1549written to the socket:
1550
1551 $handle->push_write (...);
1552 $handle->on_drain (sub {
1553 warn "all data submitted to the kernel\n";
1554 undef $handle;
1555 });
1556
1557=back
1558
1559
1560=head1 SUBCLASSING AnyEvent::Handle
1561
1562In many cases, you might want to subclass AnyEvent::Handle.
1563
1564To make this easier, a given version of AnyEvent::Handle uses these
1565conventions:
1566
1567=over 4
1568
1569=item * all constructor arguments become object members.
1570
1571At least initially, when you pass a C<tls>-argument to the constructor it
1572will end up in C<< $handle->{tls} >>. Those members might be changed or
1573mutated later on (for example C<tls> will hold the TLS connection object).
1574
1575=item * other object member names are prefixed with an C<_>.
1576
1577All object members not explicitly documented (internal use) are prefixed
1578with an underscore character, so the remaining non-C<_>-namespace is free
1579for use for subclasses.
1580
1581=item * all members not documented here and not prefixed with an underscore
1582are free to use in subclasses.
1583
1584Of course, new versions of AnyEvent::Handle may introduce more "public"
1585member variables, but thats just life, at least it is documented.
1586
1587=back
1588
947=head1 AUTHOR 1589=head1 AUTHOR
948 1590
949Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1591Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950 1592
951=cut 1593=cut

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