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Revision 1.29 by root, Sat May 24 23:10:18 2008 UTC vs.
Revision 1.130 by root, Mon Jun 29 21:00:32 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util (); 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
17This module is experimental.
18
19=cut 17=cut
20 18
21our $VERSION = '0.04'; 19our $VERSION = 4.45;
22 20
23=head1 SYNOPSIS 21=head1 SYNOPSIS
24 22
25 use AnyEvent; 23 use AnyEvent;
26 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 25
28 my $cv = AnyEvent->condvar; 26 my $cv = AnyEvent->condvar;
29 27
30 my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN); 28 my $handle =
31
32 #TODO
33
34 # or use the constructor to pass the callback:
35
36 my $ae_fh2 =
37 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
38 fh => \*STDIN, 30 fh => \*STDIN,
39 on_eof => sub { 31 on_eof => sub {
40 $cv->broadcast; 32 $cv->send;
41 }, 33 },
42 #TODO
43 ); 34 );
44 35
45 $cv->wait; 36 # send some request line
37 $handle->push_write ("getinfo\015\012");
38
39 # read the response line
40 $handle->push_read (line => sub {
41 my ($handle, $line) = @_;
42 warn "read line <$line>\n";
43 $cv->send;
44 });
45
46 $cv->recv;
46 47
47=head1 DESCRIPTION 48=head1 DESCRIPTION
48 49
49This 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
50filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
51on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
52 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
53In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
54means 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
55treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
56 60
57All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
69 73
70=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
71 75
72The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
73 77
74NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
75AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
76 81
77=item on_eof => $cb->($self) 82=item on_eof => $cb->($handle)
78 83
79Set 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.
80 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
81While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
82otherwise 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
83waiting for data. 95waiting for data.
84 96
97If an EOF condition has been detected but no C<on_eof> callback has been
98set, then a fatal error will be raised with C<$!> set to <0>.
99
85=item on_error => $cb->($self) 100=item on_error => $cb->($handle, $fatal)
86 101
87This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
88occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
89or a read error. 104connect or a read error.
90 105
91The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$fatal> being true). On
92called. 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
112Non-fatal errors can be retried by simply returning, but it is recommended
113to simply ignore this parameter and instead abondon the handle object
114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
93 116
94On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
95error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96 119
97While not mandatory, it is I<highly> recommended to set this callback, as 120While not mandatory, it is I<highly> recommended to set this callback, as
98you will not be notified of errors otherwise. The default simply calls 121you will not be notified of errors otherwise. The default simply calls
99die. 122C<croak>.
100 123
101=item on_read => $cb->($self) 124=item on_read => $cb->($handle)
102 125
103This sets the default read callback, which is called when data arrives 126This sets the default read callback, which is called when data arrives
104and no read request is in the queue. 127and no read request is in the queue (unlike read queue callbacks, this
128callback will only be called when at least one octet of data is in the
129read buffer).
105 130
106To access (and remove data from) the read buffer, use the C<< ->rbuf >> 131To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107method or access the C<$self->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly. Note that you
133must not enlarge or modify the read buffer, you can only remove data at
134the beginning from it.
108 135
109When an EOF condition is detected then AnyEvent::Handle will first try to 136When an EOF condition is detected then AnyEvent::Handle will first try to
110feed all the remaining data to the queued callbacks and C<on_read> before 137feed all the remaining data to the queued callbacks and C<on_read> before
111calling the C<on_eof> callback. If no progress can be made, then a fatal 138calling the C<on_eof> callback. If no progress can be made, then a fatal
112error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
113 140
114=item on_drain => $cb->() 141=item on_drain => $cb->($handle)
115 142
116This sets the callback that is called when the write buffer becomes empty 143This sets the callback that is called when the write buffer becomes empty
117(or when the callback is set and the buffer is empty already). 144(or when the callback is set and the buffer is empty already).
118 145
119To append to the write buffer, use the C<< ->push_write >> method. 146To append to the write buffer, use the C<< ->push_write >> method.
120 147
148This callback is useful when you don't want to put all of your write data
149into the queue at once, for example, when you want to write the contents
150of some file to the socket you might not want to read the whole file into
151memory and push it into the queue, but instead only read more data from
152the file when the write queue becomes empty.
153
154=item timeout => $fractional_seconds
155
156If non-zero, then this enables an "inactivity" timeout: whenever this many
157seconds pass without a successful read or write on the underlying file
158handle, the C<on_timeout> callback will be invoked (and if that one is
159missing, a non-fatal C<ETIMEDOUT> error will be raised).
160
161Note that timeout processing is also active when you currently do not have
162any outstanding read or write requests: If you plan to keep the connection
163idle then you should disable the timout temporarily or ignore the timeout
164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
166
167Zero (the default) disables this timeout.
168
169=item on_timeout => $cb->($handle)
170
171Called whenever the inactivity timeout passes. If you return from this
172callback, then the timeout will be reset as if some activity had happened,
173so this condition is not fatal in any way.
174
121=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
122 176
123If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 177If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124when the read buffer ever (strictly) exceeds this size. This is useful to 178when the read buffer ever (strictly) exceeds this size. This is useful to
125avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
126 180
127For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
128be configured to accept only so-and-so much data that it cannot act on 182be configured to accept only so-and-so much data that it cannot act on
129(for example, when expecting a line, an attacker could send an unlimited 183(for example, when expecting a line, an attacker could send an unlimited
130amount of data without a callback ever being called as long as the line 184amount of data without a callback ever being called as long as the line
131isn't finished). 185isn't finished).
132 186
187=item autocork => <boolean>
188
189When disabled (the default), then C<push_write> will try to immediately
190write the data to the handle, if possible. This avoids having to register
191a write watcher and wait for the next event loop iteration, but can
192be inefficient if you write multiple small chunks (on the wire, this
193disadvantage is usually avoided by your kernel's nagle algorithm, see
194C<no_delay>, but this option can save costly syscalls).
195
196When enabled, then writes will always be queued till the next event loop
197iteration. This is efficient when you do many small writes per iteration,
198but less efficient when you do a single write only per iteration (or when
199the write buffer often is full). It also increases write latency.
200
201=item no_delay => <boolean>
202
203When doing small writes on sockets, your operating system kernel might
204wait a bit for more data before actually sending it out. This is called
205the Nagle algorithm, and usually it is beneficial.
206
207In some situations you want as low a delay as possible, which can be
208accomplishd by setting this option to a true value.
209
210The default is your opertaing system's default behaviour (most likely
211enabled), this option explicitly enables or disables it, if possible.
212
133=item read_size => <bytes> 213=item read_size => <bytes>
134 214
135The default read block size (the amount of bytes this module will try to read 215The default read block size (the amount of bytes this module will
136on each [loop iteration). Default: C<4096>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
137 218
138=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
139 220
140Sets the amount of bytes (default: C<0>) that make up an "empty" write 221Sets the amount of bytes (default: C<0>) that make up an "empty" write
141buffer: If the write reaches this size or gets even samller it is 222buffer: If the write reaches this size or gets even samller it is
142considered empty. 223considered empty.
143 224
225Sometimes it can be beneficial (for performance reasons) to add data to
226the write buffer before it is fully drained, but this is a rare case, as
227the operating system kernel usually buffers data as well, so the default
228is good in almost all cases.
229
230=item linger => <seconds>
231
232If non-zero (default: C<3600>), then the destructor of the
233AnyEvent::Handle object will check whether there is still outstanding
234write data and will install a watcher that will write this data to the
235socket. No errors will be reported (this mostly matches how the operating
236system treats outstanding data at socket close time).
237
238This will not work for partial TLS data that could not be encoded
239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
241
144=item tls => "accept" | "connect" | Net::SSLeay::SSL object 242=item tls => "accept" | "connect" | Net::SSLeay::SSL object
145 243
146When this parameter is given, it enables TLS (SSL) mode, that means it 244When this parameter is given, it enables TLS (SSL) mode, that means
147will start making tls handshake and will transparently encrypt/decrypt 245AnyEvent will start a TLS handshake as soon as the conenction has been
148data. 246established and will transparently encrypt/decrypt data afterwards.
149 247
150TLS mode requires Net::SSLeay to be installed (it will be loaded 248TLS mode requires Net::SSLeay to be installed (it will be loaded
151automatically when you try to create a TLS handle). 249automatically when you try to create a TLS handle): this module doesn't
250have a dependency on that module, so if your module requires it, you have
251to add the dependency yourself.
152 252
153For the TLS server side, use C<accept>, and for the TLS client side of a 253Unlike TCP, TLS has a server and client side: for the TLS server side, use
154connection, use C<connect> mode. 254C<accept>, and for the TLS client side of a connection, use C<connect>
255mode.
155 256
156You can also provide your own TLS connection object, but you have 257You can also provide your own TLS connection object, but you have
157to make sure that you call either C<Net::SSLeay::set_connect_state> 258to make sure that you call either C<Net::SSLeay::set_connect_state>
158or C<Net::SSLeay::set_accept_state> on it before you pass it to 259or C<Net::SSLeay::set_accept_state> on it before you pass it to
159AnyEvent::Handle. 260AnyEvent::Handle.
160 261
262B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
263passing in the wrong integer will lead to certain crash. This most often
264happens when one uses a stylish C<< tls => 1 >> and is surprised about the
265segmentation fault.
266
161See the C<starttls> method if you need to start TLs negotiation later. 267See the C<< ->starttls >> method for when need to start TLS negotiation later.
162 268
163=item tls_ctx => $ssl_ctx 269=item tls_ctx => $ssl_ctx
164 270
165Use the given Net::SSLeay::CTX object to create the new TLS connection 271Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
166(unless a connection object was specified directly). If this parameter is 272(unless a connection object was specified directly). If this parameter is
167missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 273missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
168 274
275=item json => JSON or JSON::XS object
276
277This is the json coder object used by the C<json> read and write types.
278
279If you don't supply it, then AnyEvent::Handle will create and use a
280suitable one (on demand), which will write and expect UTF-8 encoded JSON
281texts.
282
283Note that you are responsible to depend on the JSON module if you want to
284use this functionality, as AnyEvent does not have a dependency itself.
285
169=back 286=back
170 287
171=cut 288=cut
172
173our (%RH, %WH);
174
175sub register_read_type($$) {
176 $RH{$_[0]} = $_[1];
177}
178
179sub register_write_type($$) {
180 $WH{$_[0]} = $_[1];
181}
182 289
183sub new { 290sub new {
184 my $class = shift; 291 my $class = shift;
185 292
186 my $self = bless { @_ }, $class; 293 my $self = bless { @_ }, $class;
187 294
188 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 295 $self->{fh} or Carp::croak "mandatory argument fh is missing";
189 296
190 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 297 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
191 298
192 if ($self->{tls}) {
193 require Net::SSLeay;
194 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 299 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
195 } 300 if $self->{tls};
196 301
197 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 302 $self->{_activity} = AnyEvent->now;
198 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 303 $self->_timeout;
304
199 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 305 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
200 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 306 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
201 307
202 $self->start_read; 308 $self->start_read
309 if $self->{on_read};
203 310
204 $self 311 $self
205} 312}
206 313
207sub _shutdown { 314sub _shutdown {
208 my ($self) = @_; 315 my ($self) = @_;
209 316
210 delete $self->{rw}; 317 delete @$self{qw(_tw _rw _ww fh rbuf wbuf on_read _queue)};
211 delete $self->{ww};
212 delete $self->{fh};
213}
214 318
319 &_freetls;
320}
321
215sub error { 322sub _error {
216 my ($self) = @_; 323 my ($self, $errno, $fatal) = @_;
217 324
218 {
219 local $!;
220 $self->_shutdown; 325 $self->_shutdown
221 } 326 if $fatal;
327
328 $! = $errno;
222 329
223 if ($self->{on_error}) { 330 if ($self->{on_error}) {
224 $self->{on_error}($self); 331 $self->{on_error}($self, $fatal);
225 } else { 332 } elsif ($self->{fh}) {
226 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 333 Carp::croak "AnyEvent::Handle uncaught error: $!";
227 } 334 }
228} 335}
229 336
230=item $fh = $handle->fh 337=item $fh = $handle->fh
231 338
232This method returns the file handle of the L<AnyEvent::Handle> object. 339This method returns the file handle used to create the L<AnyEvent::Handle> object.
233 340
234=cut 341=cut
235 342
236sub fh { $_[0]->{fh} } 343sub fh { $_[0]{fh} }
237 344
238=item $handle->on_error ($cb) 345=item $handle->on_error ($cb)
239 346
240Replace the current C<on_error> callback (see the C<on_error> constructor argument). 347Replace the current C<on_error> callback (see the C<on_error> constructor argument).
241 348
253 360
254sub on_eof { 361sub on_eof {
255 $_[0]{on_eof} = $_[1]; 362 $_[0]{on_eof} = $_[1];
256} 363}
257 364
365=item $handle->on_timeout ($cb)
366
367Replace the current C<on_timeout> callback, or disables the callback (but
368not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
369argument and method.
370
371=cut
372
373sub on_timeout {
374 $_[0]{on_timeout} = $_[1];
375}
376
377=item $handle->autocork ($boolean)
378
379Enables or disables the current autocork behaviour (see C<autocork>
380constructor argument). Changes will only take effect on the next write.
381
382=cut
383
384sub autocork {
385 $_[0]{autocork} = $_[1];
386}
387
388=item $handle->no_delay ($boolean)
389
390Enables or disables the C<no_delay> setting (see constructor argument of
391the same name for details).
392
393=cut
394
395sub no_delay {
396 $_[0]{no_delay} = $_[1];
397
398 eval {
399 local $SIG{__DIE__};
400 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
401 };
402}
403
404#############################################################################
405
406=item $handle->timeout ($seconds)
407
408Configures (or disables) the inactivity timeout.
409
410=cut
411
412sub timeout {
413 my ($self, $timeout) = @_;
414
415 $self->{timeout} = $timeout;
416 $self->_timeout;
417}
418
419# reset the timeout watcher, as neccessary
420# also check for time-outs
421sub _timeout {
422 my ($self) = @_;
423
424 if ($self->{timeout}) {
425 my $NOW = AnyEvent->now;
426
427 # when would the timeout trigger?
428 my $after = $self->{_activity} + $self->{timeout} - $NOW;
429
430 # now or in the past already?
431 if ($after <= 0) {
432 $self->{_activity} = $NOW;
433
434 if ($self->{on_timeout}) {
435 $self->{on_timeout}($self);
436 } else {
437 $self->_error (&Errno::ETIMEDOUT);
438 }
439
440 # callback could have changed timeout value, optimise
441 return unless $self->{timeout};
442
443 # calculate new after
444 $after = $self->{timeout};
445 }
446
447 Scalar::Util::weaken $self;
448 return unless $self; # ->error could have destroyed $self
449
450 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
451 delete $self->{_tw};
452 $self->_timeout;
453 });
454 } else {
455 delete $self->{_tw};
456 }
457}
458
258############################################################################# 459#############################################################################
259 460
260=back 461=back
261 462
262=head2 WRITE QUEUE 463=head2 WRITE QUEUE
283 my ($self, $cb) = @_; 484 my ($self, $cb) = @_;
284 485
285 $self->{on_drain} = $cb; 486 $self->{on_drain} = $cb;
286 487
287 $cb->($self) 488 $cb->($self)
288 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 489 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
289} 490}
290 491
291=item $handle->push_write ($data) 492=item $handle->push_write ($data)
292 493
293Queues the given scalar to be written. You can push as much data as you 494Queues the given scalar to be written. You can push as much data as you
297=cut 498=cut
298 499
299sub _drain_wbuf { 500sub _drain_wbuf {
300 my ($self) = @_; 501 my ($self) = @_;
301 502
302 if (!$self->{ww} && length $self->{wbuf}) { 503 if (!$self->{_ww} && length $self->{wbuf}) {
504
303 Scalar::Util::weaken $self; 505 Scalar::Util::weaken $self;
506
304 my $cb = sub { 507 my $cb = sub {
305 my $len = syswrite $self->{fh}, $self->{wbuf}; 508 my $len = syswrite $self->{fh}, $self->{wbuf};
306 509
307 if ($len >= 0) { 510 if ($len >= 0) {
308 substr $self->{wbuf}, 0, $len, ""; 511 substr $self->{wbuf}, 0, $len, "";
309 512
513 $self->{_activity} = AnyEvent->now;
514
310 $self->{on_drain}($self) 515 $self->{on_drain}($self)
311 if $self->{low_water_mark} >= length $self->{wbuf} 516 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
312 && $self->{on_drain}; 517 && $self->{on_drain};
313 518
314 delete $self->{ww} unless length $self->{wbuf}; 519 delete $self->{_ww} unless length $self->{wbuf};
315 } elsif ($! != EAGAIN && $! != EINTR) { 520 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
316 $self->error; 521 $self->_error ($!, 1);
317 } 522 }
318 }; 523 };
319 524
525 # try to write data immediately
526 $cb->() unless $self->{autocork};
527
528 # if still data left in wbuf, we need to poll
320 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 529 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
321 530 if length $self->{wbuf};
322 $cb->($self);
323 }; 531 };
532}
533
534our %WH;
535
536sub register_write_type($$) {
537 $WH{$_[0]} = $_[1];
324} 538}
325 539
326sub push_write { 540sub push_write {
327 my $self = shift; 541 my $self = shift;
328 542
331 545
332 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 546 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
333 ->($self, @_); 547 ->($self, @_);
334 } 548 }
335 549
336 if ($self->{filter_w}) { 550 if ($self->{tls}) {
337 $self->{filter_w}->($self, \$_[0]); 551 $self->{_tls_wbuf} .= $_[0];
552
553 &_dotls ($self);
338 } else { 554 } else {
339 $self->{wbuf} .= $_[0]; 555 $self->{wbuf} .= $_[0];
340 $self->_drain_wbuf; 556 $self->_drain_wbuf;
341 } 557 }
342} 558}
343 559
344=item $handle->push_write (type => @args) 560=item $handle->push_write (type => @args)
345 561
346=item $handle->unshift_write (type => @args)
347
348Instead of formatting your data yourself, you can also let this module do 562Instead of formatting your data yourself, you can also let this module do
349the job by specifying a type and type-specific arguments. 563the job by specifying a type and type-specific arguments.
350 564
351Predefined types are: 565Predefined types are (if you have ideas for additional types, feel free to
566drop by and tell us):
352 567
353=over 4 568=over 4
354 569
355=item netstring => $string 570=item netstring => $string
356 571
360=cut 575=cut
361 576
362register_write_type netstring => sub { 577register_write_type netstring => sub {
363 my ($self, $string) = @_; 578 my ($self, $string) = @_;
364 579
365 sprintf "%d:%s,", (length $string), $string 580 (length $string) . ":$string,"
366}; 581};
367 582
583=item packstring => $format, $data
584
585An octet string prefixed with an encoded length. The encoding C<$format>
586uses the same format as a Perl C<pack> format, but must specify a single
587integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
588optional C<!>, C<< < >> or C<< > >> modifier).
589
590=cut
591
592register_write_type packstring => sub {
593 my ($self, $format, $string) = @_;
594
595 pack "$format/a*", $string
596};
597
598=item json => $array_or_hashref
599
600Encodes the given hash or array reference into a JSON object. Unless you
601provide your own JSON object, this means it will be encoded to JSON text
602in UTF-8.
603
604JSON objects (and arrays) are self-delimiting, so you can write JSON at
605one end of a handle and read them at the other end without using any
606additional framing.
607
608The generated JSON text is guaranteed not to contain any newlines: While
609this module doesn't need delimiters after or between JSON texts to be
610able to read them, many other languages depend on that.
611
612A simple RPC protocol that interoperates easily with others is to send
613JSON arrays (or objects, although arrays are usually the better choice as
614they mimic how function argument passing works) and a newline after each
615JSON text:
616
617 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
618 $handle->push_write ("\012");
619
620An AnyEvent::Handle receiver would simply use the C<json> read type and
621rely on the fact that the newline will be skipped as leading whitespace:
622
623 $handle->push_read (json => sub { my $array = $_[1]; ... });
624
625Other languages could read single lines terminated by a newline and pass
626this line into their JSON decoder of choice.
627
628=cut
629
630register_write_type json => sub {
631 my ($self, $ref) = @_;
632
633 require JSON;
634
635 $self->{json} ? $self->{json}->encode ($ref)
636 : JSON::encode_json ($ref)
637};
638
639=item storable => $reference
640
641Freezes the given reference using L<Storable> and writes it to the
642handle. Uses the C<nfreeze> format.
643
644=cut
645
646register_write_type storable => sub {
647 my ($self, $ref) = @_;
648
649 require Storable;
650
651 pack "w/a*", Storable::nfreeze ($ref)
652};
653
368=back 654=back
369 655
370=cut 656=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
371 657
658This function (not method) lets you add your own types to C<push_write>.
659Whenever the given C<type> is used, C<push_write> will invoke the code
660reference with the handle object and the remaining arguments.
372 661
662The code reference is supposed to return a single octet string that will
663be appended to the write buffer.
664
665Note that this is a function, and all types registered this way will be
666global, so try to use unique names.
667
668=cut
373 669
374############################################################################# 670#############################################################################
375 671
376=back 672=back
377 673
384ways, the "simple" way, using only C<on_read> and the "complex" way, using 680ways, the "simple" way, using only C<on_read> and the "complex" way, using
385a queue. 681a queue.
386 682
387In the simple case, you just install an C<on_read> callback and whenever 683In the simple case, you just install an C<on_read> callback and whenever
388new data arrives, it will be called. You can then remove some data (if 684new data arrives, it will be called. You can then remove some data (if
389enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 685enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
390or not. 686leave the data there if you want to accumulate more (e.g. when only a
687partial message has been received so far).
391 688
392In the more complex case, you want to queue multiple callbacks. In this 689In the more complex case, you want to queue multiple callbacks. In this
393case, AnyEvent::Handle will call the first queued callback each time new 690case, AnyEvent::Handle will call the first queued callback each time new
394data arrives and removes it when it has done its job (see C<push_read>, 691data arrives (also the first time it is queued) and removes it when it has
395below). 692done its job (see C<push_read>, below).
396 693
397This way you can, for example, push three line-reads, followed by reading 694This way you can, for example, push three line-reads, followed by reading
398a chunk of data, and AnyEvent::Handle will execute them in order. 695a chunk of data, and AnyEvent::Handle will execute them in order.
399 696
400Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 697Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
401the specified number of bytes which give an XML datagram. 698the specified number of bytes which give an XML datagram.
402 699
403 # in the default state, expect some header bytes 700 # in the default state, expect some header bytes
404 $handle->on_read (sub { 701 $handle->on_read (sub {
405 # some data is here, now queue the length-header-read (4 octets) 702 # some data is here, now queue the length-header-read (4 octets)
406 shift->unshift_read_chunk (4, sub { 703 shift->unshift_read (chunk => 4, sub {
407 # header arrived, decode 704 # header arrived, decode
408 my $len = unpack "N", $_[1]; 705 my $len = unpack "N", $_[1];
409 706
410 # now read the payload 707 # now read the payload
411 shift->unshift_read_chunk ($len, sub { 708 shift->unshift_read (chunk => $len, sub {
412 my $xml = $_[1]; 709 my $xml = $_[1];
413 # handle xml 710 # handle xml
414 }); 711 });
415 }); 712 });
416 }); 713 });
417 714
418Example 2: Implement a client for a protocol that replies either with 715Example 2: Implement a client for a protocol that replies either with "OK"
419"OK" and another line or "ERROR" for one request, and 64 bytes for the 716and another line or "ERROR" for the first request that is sent, and 64
420second request. Due tot he availability of a full queue, we can just 717bytes for the second request. Due to the availability of a queue, we can
421pipeline sending both requests and manipulate the queue as necessary in 718just pipeline sending both requests and manipulate the queue as necessary
422the callbacks: 719in the callbacks.
423 720
424 # request one 721When the first callback is called and sees an "OK" response, it will
722C<unshift> another line-read. This line-read will be queued I<before> the
72364-byte chunk callback.
724
725 # request one, returns either "OK + extra line" or "ERROR"
425 $handle->push_write ("request 1\015\012"); 726 $handle->push_write ("request 1\015\012");
426 727
427 # we expect "ERROR" or "OK" as response, so push a line read 728 # we expect "ERROR" or "OK" as response, so push a line read
428 $handle->push_read_line (sub { 729 $handle->push_read (line => sub {
429 # if we got an "OK", we have to _prepend_ another line, 730 # if we got an "OK", we have to _prepend_ another line,
430 # so it will be read before the second request reads its 64 bytes 731 # so it will be read before the second request reads its 64 bytes
431 # which are already in the queue when this callback is called 732 # which are already in the queue when this callback is called
432 # we don't do this in case we got an error 733 # we don't do this in case we got an error
433 if ($_[1] eq "OK") { 734 if ($_[1] eq "OK") {
434 $_[0]->unshift_read_line (sub { 735 $_[0]->unshift_read (line => sub {
435 my $response = $_[1]; 736 my $response = $_[1];
436 ... 737 ...
437 }); 738 });
438 } 739 }
439 }); 740 });
440 741
441 # request two 742 # request two, simply returns 64 octets
442 $handle->push_write ("request 2\015\012"); 743 $handle->push_write ("request 2\015\012");
443 744
444 # simply read 64 bytes, always 745 # simply read 64 bytes, always
445 $handle->push_read_chunk (64, sub { 746 $handle->push_read (chunk => 64, sub {
446 my $response = $_[1]; 747 my $response = $_[1];
447 ... 748 ...
448 }); 749 });
449 750
450=over 4 751=over 4
451 752
452=cut 753=cut
453 754
454sub _drain_rbuf { 755sub _drain_rbuf {
455 my ($self) = @_; 756 my ($self) = @_;
757
758 local $self->{_in_drain} = 1;
456 759
457 if ( 760 if (
458 defined $self->{rbuf_max} 761 defined $self->{rbuf_max}
459 && $self->{rbuf_max} < length $self->{rbuf} 762 && $self->{rbuf_max} < length $self->{rbuf}
460 ) { 763 ) {
461 $! = &Errno::ENOSPC; return $self->error; 764 $self->_error (&Errno::ENOSPC, 1), return;
462 } 765 }
463 766
464 return if $self->{in_drain}; 767 while () {
465 local $self->{in_drain} = 1; 768 # we need to use a separate tls read buffer, as we must not receive data while
769 # we are draining the buffer, and this can only happen with TLS.
770 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
466 771
467 while (my $len = length $self->{rbuf}) { 772 my $len = length $self->{rbuf};
468 no strict 'refs'; 773
469 if (my $cb = shift @{ $self->{queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
470 unless ($cb->($self)) { 775 unless ($cb->($self)) {
471 if ($self->{eof}) { 776 if ($self->{_eof}) {
472 # no progress can be made (not enough data and no data forthcoming) 777 # no progress can be made (not enough data and no data forthcoming)
473 $! = &Errno::EPIPE; return $self->error; 778 $self->_error (&Errno::EPIPE, 1), return;
474 } 779 }
475 780
476 unshift @{ $self->{queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
477 return; 782 last;
478 } 783 }
479 } elsif ($self->{on_read}) { 784 } elsif ($self->{on_read}) {
785 last unless $len;
786
480 $self->{on_read}($self); 787 $self->{on_read}($self);
481 788
482 if ( 789 if (
483 $self->{eof} # if no further data will arrive
484 && $len == length $self->{rbuf} # and no data has been consumed 790 $len == length $self->{rbuf} # if no data has been consumed
485 && !@{ $self->{queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
486 && $self->{on_read} # and we still want to read data 792 && $self->{on_read} # but we still have on_read
487 ) { 793 ) {
794 # no further data will arrive
488 # then no progress can be made 795 # so no progress can be made
489 $! = &Errno::EPIPE; return $self->error; 796 $self->_error (&Errno::EPIPE, 1), return
797 if $self->{_eof};
798
799 last; # more data might arrive
490 } 800 }
491 } else { 801 } else {
492 # read side becomes idle 802 # read side becomes idle
493 delete $self->{rw}; 803 delete $self->{_rw} unless $self->{tls};
494 return; 804 last;
495 } 805 }
496 } 806 }
497 807
498 if ($self->{eof}) { 808 if ($self->{_eof}) {
499 $self->_shutdown; 809 if ($self->{on_eof}) {
500 $self->{on_eof}($self) 810 $self->{on_eof}($self)
501 if $self->{on_eof}; 811 } else {
812 $self->_error (0, 1);
813 }
814 }
815
816 # may need to restart read watcher
817 unless ($self->{_rw}) {
818 $self->start_read
819 if $self->{on_read} || @{ $self->{_queue} };
502 } 820 }
503} 821}
504 822
505=item $handle->on_read ($cb) 823=item $handle->on_read ($cb)
506 824
512 830
513sub on_read { 831sub on_read {
514 my ($self, $cb) = @_; 832 my ($self, $cb) = @_;
515 833
516 $self->{on_read} = $cb; 834 $self->{on_read} = $cb;
835 $self->_drain_rbuf if $cb && !$self->{_in_drain};
517} 836}
518 837
519=item $handle->rbuf 838=item $handle->rbuf
520 839
521Returns the read buffer (as a modifiable lvalue). 840Returns the read buffer (as a modifiable lvalue).
522 841
523You can access the read buffer directly as the C<< ->{rbuf} >> member, if 842You can access the read buffer directly as the C<< ->{rbuf} >>
524you want. 843member, if you want. However, the only operation allowed on the
844read buffer (apart from looking at it) is removing data from its
845beginning. Otherwise modifying or appending to it is not allowed and will
846lead to hard-to-track-down bugs.
525 847
526NOTE: The read buffer should only be used or modified if the C<on_read>, 848NOTE: The read buffer should only be used or modified if the C<on_read>,
527C<push_read> or C<unshift_read> methods are used. The other read methods 849C<push_read> or C<unshift_read> methods are used. The other read methods
528automatically manage the read buffer. 850automatically manage the read buffer.
529 851
552interested in (which can be none at all) and return a true value. After returning 874interested in (which can be none at all) and return a true value. After returning
553true, it will be removed from the queue. 875true, it will be removed from the queue.
554 876
555=cut 877=cut
556 878
879our %RH;
880
881sub register_read_type($$) {
882 $RH{$_[0]} = $_[1];
883}
884
557sub push_read { 885sub push_read {
558 my $self = shift; 886 my $self = shift;
559 my $cb = pop; 887 my $cb = pop;
560 888
561 if (@_) { 889 if (@_) {
563 891
564 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 892 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
565 ->($self, $cb, @_); 893 ->($self, $cb, @_);
566 } 894 }
567 895
568 push @{ $self->{queue} }, $cb; 896 push @{ $self->{_queue} }, $cb;
569 $self->_drain_rbuf; 897 $self->_drain_rbuf unless $self->{_in_drain};
570} 898}
571 899
572sub unshift_read { 900sub unshift_read {
573 my $self = shift; 901 my $self = shift;
574 my $cb = pop; 902 my $cb = pop;
579 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 907 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
580 ->($self, $cb, @_); 908 ->($self, $cb, @_);
581 } 909 }
582 910
583 911
584 unshift @{ $self->{queue} }, $cb; 912 unshift @{ $self->{_queue} }, $cb;
585 $self->_drain_rbuf; 913 $self->_drain_rbuf unless $self->{_in_drain};
586} 914}
587 915
588=item $handle->push_read (type => @args, $cb) 916=item $handle->push_read (type => @args, $cb)
589 917
590=item $handle->unshift_read (type => @args, $cb) 918=item $handle->unshift_read (type => @args, $cb)
591 919
592Instead of providing a callback that parses the data itself you can chose 920Instead of providing a callback that parses the data itself you can chose
593between a number of predefined parsing formats, for chunks of data, lines 921between a number of predefined parsing formats, for chunks of data, lines
594etc. 922etc.
595 923
596The types currently supported are: 924Predefined types are (if you have ideas for additional types, feel free to
925drop by and tell us):
597 926
598=over 4 927=over 4
599 928
600=item chunk => $octets, $cb->($self, $data) 929=item chunk => $octets, $cb->($handle, $data)
601 930
602Invoke the callback only once C<$octets> bytes have been read. Pass the 931Invoke the callback only once C<$octets> bytes have been read. Pass the
603data read to the callback. The callback will never be called with less 932data read to the callback. The callback will never be called with less
604data. 933data.
605 934
619 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 948 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
620 1 949 1
621 } 950 }
622}; 951};
623 952
624# compatibility with older API
625sub push_read_chunk {
626 $_[0]->push_read (chunk => $_[1], $_[2]);
627}
628
629sub unshift_read_chunk {
630 $_[0]->unshift_read (chunk => $_[1], $_[2]);
631}
632
633=item line => [$eol, ]$cb->($self, $line, $eol) 953=item line => [$eol, ]$cb->($handle, $line, $eol)
634 954
635The callback will be called only once a full line (including the end of 955The callback will be called only once a full line (including the end of
636line marker, C<$eol>) has been read. This line (excluding the end of line 956line marker, C<$eol>) has been read. This line (excluding the end of line
637marker) will be passed to the callback as second argument (C<$line>), and 957marker) will be passed to the callback as second argument (C<$line>), and
638the end of line marker as the third argument (C<$eol>). 958the end of line marker as the third argument (C<$eol>).
652=cut 972=cut
653 973
654register_read_type line => sub { 974register_read_type line => sub {
655 my ($self, $cb, $eol) = @_; 975 my ($self, $cb, $eol) = @_;
656 976
657 $eol = qr|(\015?\012)| if @_ < 3; 977 if (@_ < 3) {
978 # this is more than twice as fast as the generic code below
979 sub {
980 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
981
982 $cb->($_[0], $1, $2);
983 1
984 }
985 } else {
658 $eol = quotemeta $eol unless ref $eol; 986 $eol = quotemeta $eol unless ref $eol;
659 $eol = qr|^(.*?)($eol)|s; 987 $eol = qr|^(.*?)($eol)|s;
988
989 sub {
990 $_[0]{rbuf} =~ s/$eol// or return;
991
992 $cb->($_[0], $1, $2);
993 1
994 }
995 }
996};
997
998=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
999
1000Makes a regex match against the regex object C<$accept> and returns
1001everything up to and including the match.
1002
1003Example: read a single line terminated by '\n'.
1004
1005 $handle->push_read (regex => qr<\n>, sub { ... });
1006
1007If C<$reject> is given and not undef, then it determines when the data is
1008to be rejected: it is matched against the data when the C<$accept> regex
1009does not match and generates an C<EBADMSG> error when it matches. This is
1010useful to quickly reject wrong data (to avoid waiting for a timeout or a
1011receive buffer overflow).
1012
1013Example: expect a single decimal number followed by whitespace, reject
1014anything else (not the use of an anchor).
1015
1016 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1017
1018If C<$skip> is given and not C<undef>, then it will be matched against
1019the receive buffer when neither C<$accept> nor C<$reject> match,
1020and everything preceding and including the match will be accepted
1021unconditionally. This is useful to skip large amounts of data that you
1022know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1023have to start matching from the beginning. This is purely an optimisation
1024and is usually worth only when you expect more than a few kilobytes.
1025
1026Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1027expect the header to be very large (it isn't in practise, but...), we use
1028a skip regex to skip initial portions. The skip regex is tricky in that
1029it only accepts something not ending in either \015 or \012, as these are
1030required for the accept regex.
1031
1032 $handle->push_read (regex =>
1033 qr<\015\012\015\012>,
1034 undef, # no reject
1035 qr<^.*[^\015\012]>,
1036 sub { ... });
1037
1038=cut
1039
1040register_read_type regex => sub {
1041 my ($self, $cb, $accept, $reject, $skip) = @_;
1042
1043 my $data;
1044 my $rbuf = \$self->{rbuf};
660 1045
661 sub { 1046 sub {
662 $_[0]{rbuf} =~ s/$eol// or return; 1047 # accept
663 1048 if ($$rbuf =~ $accept) {
664 $cb->($_[0], $1, $2); 1049 $data .= substr $$rbuf, 0, $+[0], "";
1050 $cb->($self, $data);
1051 return 1;
1052 }
665 1 1053
1054 # reject
1055 if ($reject && $$rbuf =~ $reject) {
1056 $self->_error (&Errno::EBADMSG);
1057 }
1058
1059 # skip
1060 if ($skip && $$rbuf =~ $skip) {
1061 $data .= substr $$rbuf, 0, $+[0], "";
1062 }
1063
1064 ()
666 } 1065 }
667}; 1066};
668 1067
669# compatibility with older API
670sub push_read_line {
671 my $self = shift;
672 $self->push_read (line => @_);
673}
674
675sub unshift_read_line {
676 my $self = shift;
677 $self->unshift_read (line => @_);
678}
679
680=item netstring => $cb->($string) 1068=item netstring => $cb->($handle, $string)
681 1069
682A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1070A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
683 1071
684Throws an error with C<$!> set to EBADMSG on format violations. 1072Throws an error with C<$!> set to EBADMSG on format violations.
685 1073
689 my ($self, $cb) = @_; 1077 my ($self, $cb) = @_;
690 1078
691 sub { 1079 sub {
692 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1080 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
693 if ($_[0]{rbuf} =~ /[^0-9]/) { 1081 if ($_[0]{rbuf} =~ /[^0-9]/) {
694 $! = &Errno::EBADMSG; 1082 $self->_error (&Errno::EBADMSG);
695 $self->error;
696 } 1083 }
697 return; 1084 return;
698 } 1085 }
699 1086
700 my $len = $1; 1087 my $len = $1;
703 my $string = $_[1]; 1090 my $string = $_[1];
704 $_[0]->unshift_read (chunk => 1, sub { 1091 $_[0]->unshift_read (chunk => 1, sub {
705 if ($_[1] eq ",") { 1092 if ($_[1] eq ",") {
706 $cb->($_[0], $string); 1093 $cb->($_[0], $string);
707 } else { 1094 } else {
708 $! = &Errno::EBADMSG; 1095 $self->_error (&Errno::EBADMSG);
709 $self->error;
710 } 1096 }
711 }); 1097 });
712 }); 1098 });
713 1099
714 1 1100 1
715 } 1101 }
716}; 1102};
717 1103
1104=item packstring => $format, $cb->($handle, $string)
1105
1106An octet string prefixed with an encoded length. The encoding C<$format>
1107uses the same format as a Perl C<pack> format, but must specify a single
1108integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1109optional C<!>, C<< < >> or C<< > >> modifier).
1110
1111For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1112EPP uses a prefix of C<N> (4 octtes).
1113
1114Example: read a block of data prefixed by its length in BER-encoded
1115format (very efficient).
1116
1117 $handle->push_read (packstring => "w", sub {
1118 my ($handle, $data) = @_;
1119 });
1120
1121=cut
1122
1123register_read_type packstring => sub {
1124 my ($self, $cb, $format) = @_;
1125
1126 sub {
1127 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1128 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1129 or return;
1130
1131 $format = length pack $format, $len;
1132
1133 # bypass unshift if we already have the remaining chunk
1134 if ($format + $len <= length $_[0]{rbuf}) {
1135 my $data = substr $_[0]{rbuf}, $format, $len;
1136 substr $_[0]{rbuf}, 0, $format + $len, "";
1137 $cb->($_[0], $data);
1138 } else {
1139 # remove prefix
1140 substr $_[0]{rbuf}, 0, $format, "";
1141
1142 # read remaining chunk
1143 $_[0]->unshift_read (chunk => $len, $cb);
1144 }
1145
1146 1
1147 }
1148};
1149
1150=item json => $cb->($handle, $hash_or_arrayref)
1151
1152Reads a JSON object or array, decodes it and passes it to the
1153callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1154
1155If a C<json> object was passed to the constructor, then that will be used
1156for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1157
1158This read type uses the incremental parser available with JSON version
11592.09 (and JSON::XS version 2.2) and above. You have to provide a
1160dependency on your own: this module will load the JSON module, but
1161AnyEvent does not depend on it itself.
1162
1163Since JSON texts are fully self-delimiting, the C<json> read and write
1164types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1165the C<json> write type description, above, for an actual example.
1166
1167=cut
1168
1169register_read_type json => sub {
1170 my ($self, $cb) = @_;
1171
1172 require JSON;
1173
1174 my $data;
1175 my $rbuf = \$self->{rbuf};
1176
1177 my $json = $self->{json} ||= JSON->new->utf8;
1178
1179 sub {
1180 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1181
1182 if ($ref) {
1183 $self->{rbuf} = $json->incr_text;
1184 $json->incr_text = "";
1185 $cb->($self, $ref);
1186
1187 1
1188 } elsif ($@) {
1189 # error case
1190 $json->incr_skip;
1191
1192 $self->{rbuf} = $json->incr_text;
1193 $json->incr_text = "";
1194
1195 $self->_error (&Errno::EBADMSG);
1196
1197 ()
1198 } else {
1199 $self->{rbuf} = "";
1200
1201 ()
1202 }
1203 }
1204};
1205
1206=item storable => $cb->($handle, $ref)
1207
1208Deserialises a L<Storable> frozen representation as written by the
1209C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1210data).
1211
1212Raises C<EBADMSG> error if the data could not be decoded.
1213
1214=cut
1215
1216register_read_type storable => sub {
1217 my ($self, $cb) = @_;
1218
1219 require Storable;
1220
1221 sub {
1222 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1223 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1224 or return;
1225
1226 my $format = length pack "w", $len;
1227
1228 # bypass unshift if we already have the remaining chunk
1229 if ($format + $len <= length $_[0]{rbuf}) {
1230 my $data = substr $_[0]{rbuf}, $format, $len;
1231 substr $_[0]{rbuf}, 0, $format + $len, "";
1232 $cb->($_[0], Storable::thaw ($data));
1233 } else {
1234 # remove prefix
1235 substr $_[0]{rbuf}, 0, $format, "";
1236
1237 # read remaining chunk
1238 $_[0]->unshift_read (chunk => $len, sub {
1239 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1240 $cb->($_[0], $ref);
1241 } else {
1242 $self->_error (&Errno::EBADMSG);
1243 }
1244 });
1245 }
1246
1247 1
1248 }
1249};
1250
718=back 1251=back
719 1252
1253=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
1254
1255This function (not method) lets you add your own types to C<push_read>.
1256
1257Whenever the given C<type> is used, C<push_read> will invoke the code
1258reference with the handle object, the callback and the remaining
1259arguments.
1260
1261The code reference is supposed to return a callback (usually a closure)
1262that works as a plain read callback (see C<< ->push_read ($cb) >>).
1263
1264It should invoke the passed callback when it is done reading (remember to
1265pass C<$handle> as first argument as all other callbacks do that).
1266
1267Note that this is a function, and all types registered this way will be
1268global, so try to use unique names.
1269
1270For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
1271search for C<register_read_type>)).
1272
720=item $handle->stop_read 1273=item $handle->stop_read
721 1274
722=item $handle->start_read 1275=item $handle->start_read
723 1276
724In rare cases you actually do not want to read anything from the 1277In rare cases you actually do not want to read anything from the
725socket. In this case you can call C<stop_read>. Neither C<on_read> no 1278socket. In this case you can call C<stop_read>. Neither C<on_read> nor
726any queued callbacks will be executed then. To start reading again, call 1279any queued callbacks will be executed then. To start reading again, call
727C<start_read>. 1280C<start_read>.
728 1281
1282Note that AnyEvent::Handle will automatically C<start_read> for you when
1283you change the C<on_read> callback or push/unshift a read callback, and it
1284will automatically C<stop_read> for you when neither C<on_read> is set nor
1285there are any read requests in the queue.
1286
1287These methods will have no effect when in TLS mode (as TLS doesn't support
1288half-duplex connections).
1289
729=cut 1290=cut
730 1291
731sub stop_read { 1292sub stop_read {
732 my ($self) = @_; 1293 my ($self) = @_;
733 1294
734 delete $self->{rw}; 1295 delete $self->{_rw} unless $self->{tls};
735} 1296}
736 1297
737sub start_read { 1298sub start_read {
738 my ($self) = @_; 1299 my ($self) = @_;
739 1300
740 unless ($self->{rw} || $self->{eof}) { 1301 unless ($self->{_rw} || $self->{_eof}) {
741 Scalar::Util::weaken $self; 1302 Scalar::Util::weaken $self;
742 1303
743 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1304 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
744 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1305 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
745 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1306 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
746 1307
747 if ($len > 0) { 1308 if ($len > 0) {
748 $self->{filter_r} 1309 $self->{_activity} = AnyEvent->now;
749 ? $self->{filter_r}->($self, $rbuf) 1310
750 : $self->_drain_rbuf; 1311 if ($self->{tls}) {
1312 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1313
1314 &_dotls ($self);
1315 } else {
1316 $self->_drain_rbuf unless $self->{_in_drain};
1317 }
751 1318
752 } elsif (defined $len) { 1319 } elsif (defined $len) {
753 delete $self->{rw}; 1320 delete $self->{_rw};
754 $self->{eof} = 1; 1321 $self->{_eof} = 1;
755 $self->_drain_rbuf; 1322 $self->_drain_rbuf unless $self->{_in_drain};
756 1323
757 } elsif ($! != EAGAIN && $! != EINTR) { 1324 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
758 return $self->error; 1325 return $self->_error ($!, 1);
759 } 1326 }
760 }); 1327 });
761 } 1328 }
762} 1329}
763 1330
1331# poll the write BIO and send the data if applicable
764sub _dotls { 1332sub _dotls {
765 my ($self) = @_; 1333 my ($self) = @_;
766 1334
1335 my $tmp;
1336
767 if (length $self->{tls_wbuf}) { 1337 if (length $self->{_tls_wbuf}) {
768 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1338 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
769 substr $self->{tls_wbuf}, 0, $len, ""; 1339 substr $self->{_tls_wbuf}, 0, $tmp, "";
770 } 1340 }
771 } 1341 }
772 1342
773 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1343 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1344 unless (length $tmp) {
1345 # let's treat SSL-eof as we treat normal EOF
1346 delete $self->{_rw};
1347 $self->{_eof} = 1;
1348 &_freetls;
1349 }
1350
1351 $self->{_tls_rbuf} .= $tmp;
1352 $self->_drain_rbuf unless $self->{_in_drain};
1353 $self->{tls} or return; # tls session might have gone away in callback
1354 }
1355
1356 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1357
1358 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1359 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1360 return $self->_error ($!, 1);
1361 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1362 return $self->_error (&Errno::EIO, 1);
1363 }
1364
1365 # all other errors are fine for our purposes
1366 }
1367
1368 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
774 $self->{wbuf} .= $buf; 1369 $self->{wbuf} .= $tmp;
775 $self->_drain_wbuf; 1370 $self->_drain_wbuf;
776 }
777
778 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
779 $self->{rbuf} .= $buf;
780 $self->_drain_rbuf;
781 }
782
783 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
784
785 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
786 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
787 $self->error;
788 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
789 $! = &Errno::EIO;
790 $self->error;
791 }
792
793 # all others are fine for our purposes
794 } 1371 }
795} 1372}
796 1373
797=item $handle->starttls ($tls[, $tls_ctx]) 1374=item $handle->starttls ($tls[, $tls_ctx])
798 1375
804C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1381C<"connect">, C<"accept"> or an existing Net::SSLeay object).
805 1382
806The second argument is the optional C<Net::SSLeay::CTX> object that is 1383The second argument is the optional C<Net::SSLeay::CTX> object that is
807used when AnyEvent::Handle has to create its own TLS connection object. 1384used when AnyEvent::Handle has to create its own TLS connection object.
808 1385
809=cut 1386The TLS connection object will end up in C<< $handle->{tls} >> after this
1387call and can be used or changed to your liking. Note that the handshake
1388might have already started when this function returns.
810 1389
811# TODO: maybe document... 1390If it an error to start a TLS handshake more than once per
1391AnyEvent::Handle object (this is due to bugs in OpenSSL).
1392
1393=cut
1394
812sub starttls { 1395sub starttls {
813 my ($self, $ssl, $ctx) = @_; 1396 my ($self, $ssl, $ctx) = @_;
814 1397
815 $self->stoptls; 1398 require Net::SSLeay;
816 1399
1400 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1401 if $self->{tls};
1402
817 if ($ssl eq "accept") { 1403 if ($ssl eq "accept") {
818 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1404 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
819 Net::SSLeay::set_accept_state ($ssl); 1405 Net::SSLeay::set_accept_state ($ssl);
820 } elsif ($ssl eq "connect") { 1406 } elsif ($ssl eq "connect") {
821 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1407 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
827 # basically, this is deep magic (because SSL_read should have the same issues) 1413 # basically, this is deep magic (because SSL_read should have the same issues)
828 # but the openssl maintainers basically said: "trust us, it just works". 1414 # but the openssl maintainers basically said: "trust us, it just works".
829 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1415 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
830 # and mismaintained ssleay-module doesn't even offer them). 1416 # and mismaintained ssleay-module doesn't even offer them).
831 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1417 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1418 #
1419 # in short: this is a mess.
1420 #
1421 # note that we do not try to keep the length constant between writes as we are required to do.
1422 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1423 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1424 # have identity issues in that area.
832 Net::SSLeay::CTX_set_mode ($self->{tls}, 1425 Net::SSLeay::CTX_set_mode ($self->{tls},
833 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1426 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
834 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1427 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
835 1428
836 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
837 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1430 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
838 1431
839 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1432 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
840 1433
841 $self->{filter_w} = sub { 1434 &_dotls; # need to trigger the initial handshake
842 $_[0]{tls_wbuf} .= ${$_[1]}; 1435 $self->start_read; # make sure we actually do read
843 &_dotls;
844 };
845 $self->{filter_r} = sub {
846 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
847 &_dotls;
848 };
849} 1436}
850 1437
851=item $handle->stoptls 1438=item $handle->stoptls
852 1439
853Destroys the SSL connection, if any. Partial read or write data will be 1440Shuts down the SSL connection - this makes a proper EOF handshake by
854lost. 1441sending a close notify to the other side, but since OpenSSL doesn't
1442support non-blocking shut downs, it is not possible to re-use the stream
1443afterwards.
855 1444
856=cut 1445=cut
857 1446
858sub stoptls { 1447sub stoptls {
859 my ($self) = @_; 1448 my ($self) = @_;
860 1449
1450 if ($self->{tls}) {
1451 Net::SSLeay::shutdown ($self->{tls});
1452
1453 &_dotls;
1454
1455 # we don't give a shit. no, we do, but we can't. no...
1456 # we, we... have to use openssl :/
1457 &_freetls;
1458 }
1459}
1460
1461sub _freetls {
1462 my ($self) = @_;
1463
1464 return unless $self->{tls};
1465
861 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1466 Net::SSLeay::free (delete $self->{tls});
862 delete $self->{tls_rbio}; 1467
863 delete $self->{tls_wbio}; 1468 delete @$self{qw(_rbio _wbio _tls_wbuf)};
864 delete $self->{tls_wbuf};
865 delete $self->{filter_r};
866 delete $self->{filter_w};
867} 1469}
868 1470
869sub DESTROY { 1471sub DESTROY {
870 my $self = shift; 1472 my ($self) = @_;
871 1473
872 $self->stoptls; 1474 &_freetls;
1475
1476 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1477
1478 if ($linger && length $self->{wbuf}) {
1479 my $fh = delete $self->{fh};
1480 my $wbuf = delete $self->{wbuf};
1481
1482 my @linger;
1483
1484 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1485 my $len = syswrite $fh, $wbuf, length $wbuf;
1486
1487 if ($len > 0) {
1488 substr $wbuf, 0, $len, "";
1489 } else {
1490 @linger = (); # end
1491 }
1492 });
1493 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1494 @linger = ();
1495 });
1496 }
1497}
1498
1499=item $handle->destroy
1500
1501Shuts down the handle object as much as possible - this call ensures that
1502no further callbacks will be invoked and resources will be freed as much
1503as possible. You must not call any methods on the object afterwards.
1504
1505Normally, you can just "forget" any references to an AnyEvent::Handle
1506object and it will simply shut down. This works in fatal error and EOF
1507callbacks, as well as code outside. It does I<NOT> work in a read or write
1508callback, so when you want to destroy the AnyEvent::Handle object from
1509within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1510that case.
1511
1512The handle might still linger in the background and write out remaining
1513data, as specified by the C<linger> option, however.
1514
1515=cut
1516
1517sub destroy {
1518 my ($self) = @_;
1519
1520 $self->DESTROY;
1521 %$self = ();
873} 1522}
874 1523
875=item AnyEvent::Handle::TLS_CTX 1524=item AnyEvent::Handle::TLS_CTX
876 1525
877This function creates and returns the Net::SSLeay::CTX object used by 1526This function creates and returns the Net::SSLeay::CTX object used by
907 } 1556 }
908} 1557}
909 1558
910=back 1559=back
911 1560
1561
1562=head1 NONFREQUENTLY ASKED QUESTIONS
1563
1564=over 4
1565
1566=item I C<undef> the AnyEvent::Handle reference inside my callback and
1567still get further invocations!
1568
1569That's because AnyEvent::Handle keeps a reference to itself when handling
1570read or write callbacks.
1571
1572It is only safe to "forget" the reference inside EOF or error callbacks,
1573from within all other callbacks, you need to explicitly call the C<<
1574->destroy >> method.
1575
1576=item I get different callback invocations in TLS mode/Why can't I pause
1577reading?
1578
1579Unlike, say, TCP, TLS connections do not consist of two independent
1580communication channels, one for each direction. Or put differently. The
1581read and write directions are not independent of each other: you cannot
1582write data unless you are also prepared to read, and vice versa.
1583
1584This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1585callback invocations when you are not expecting any read data - the reason
1586is that AnyEvent::Handle always reads in TLS mode.
1587
1588During the connection, you have to make sure that you always have a
1589non-empty read-queue, or an C<on_read> watcher. At the end of the
1590connection (or when you no longer want to use it) you can call the
1591C<destroy> method.
1592
1593=item How do I read data until the other side closes the connection?
1594
1595If you just want to read your data into a perl scalar, the easiest way
1596to achieve this is by setting an C<on_read> callback that does nothing,
1597clearing the C<on_eof> callback and in the C<on_error> callback, the data
1598will be in C<$_[0]{rbuf}>:
1599
1600 $handle->on_read (sub { });
1601 $handle->on_eof (undef);
1602 $handle->on_error (sub {
1603 my $data = delete $_[0]{rbuf};
1604 undef $handle;
1605 });
1606
1607The reason to use C<on_error> is that TCP connections, due to latencies
1608and packets loss, might get closed quite violently with an error, when in
1609fact, all data has been received.
1610
1611It is usually better to use acknowledgements when transferring data,
1612to make sure the other side hasn't just died and you got the data
1613intact. This is also one reason why so many internet protocols have an
1614explicit QUIT command.
1615
1616=item I don't want to destroy the handle too early - how do I wait until
1617all data has been written?
1618
1619After writing your last bits of data, set the C<on_drain> callback
1620and destroy the handle in there - with the default setting of
1621C<low_water_mark> this will be called precisely when all data has been
1622written to the socket:
1623
1624 $handle->push_write (...);
1625 $handle->on_drain (sub {
1626 warn "all data submitted to the kernel\n";
1627 undef $handle;
1628 });
1629
1630=back
1631
1632
1633=head1 SUBCLASSING AnyEvent::Handle
1634
1635In many cases, you might want to subclass AnyEvent::Handle.
1636
1637To make this easier, a given version of AnyEvent::Handle uses these
1638conventions:
1639
1640=over 4
1641
1642=item * all constructor arguments become object members.
1643
1644At least initially, when you pass a C<tls>-argument to the constructor it
1645will end up in C<< $handle->{tls} >>. Those members might be changed or
1646mutated later on (for example C<tls> will hold the TLS connection object).
1647
1648=item * other object member names are prefixed with an C<_>.
1649
1650All object members not explicitly documented (internal use) are prefixed
1651with an underscore character, so the remaining non-C<_>-namespace is free
1652for use for subclasses.
1653
1654=item * all members not documented here and not prefixed with an underscore
1655are free to use in subclasses.
1656
1657Of course, new versions of AnyEvent::Handle may introduce more "public"
1658member variables, but thats just life, at least it is documented.
1659
1660=back
1661
912=head1 AUTHOR 1662=head1 AUTHOR
913 1663
914Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1664Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
915 1665
916=cut 1666=cut

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