[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent/Handle.pm

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.79 by root, Sun Jul 27 08:37:56 2008 UTC vs.
Revision 1.131 by root, Tue Jun 30 22:42:33 2009 UTC

…		…
14		14
15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	=cut	17	=cut
18		18
19	our $VERSION = 4.22;	19	our $VERSION = 4.45;
20		20
21	=head1 SYNOPSIS	21	=head1 SYNOPSIS
22		22
23	use AnyEvent;	23	use AnyEvent;
24	use AnyEvent::Handle;	24	use AnyEvent::Handle;
…		…
27		27
28	my $handle =	28	my $handle =
29	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
30	fh => \*STDIN,	30	fh => \*STDIN,
31	on_eof => sub {	31	on_eof => sub {
32	$cv->broadcast;	32	$cv->send;
33	},	33	},
34	);	34	);
35		35
36	# send some request line	36	# send some request line
37	$handle->push_write ("getinfo\015\012");	37	$handle->push_write ("getinfo\015\012");
…		…
49		49
50	This module is a helper module to make it easier to do event-based I/O on	50	This module is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
52	on sockets see L<AnyEvent::Util>.	52	on sockets see L<AnyEvent::Util>.
53		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
54	In the following, when the documentation refers to of "bytes" then this	57	In the following, when the documentation refers to of "bytes" then this
55	means characters. As sysread and syswrite are used for all I/O, their	58	means characters. As sysread and syswrite are used for all I/O, their
56	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
57		60
58	All callbacks will be invoked with the handle object as their first	61	All callbacks will be invoked with the handle object as their first
…		…
60		63
61	=head1 METHODS	64	=head1 METHODS
62		65
63	=over 4	66	=over 4
64		67
65	=item B<new (%args)>	68	=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
66		69
67	The constructor supports these arguments (all as key => value pairs).	70	The constructor supports these arguments (all as C<< key => value >> pairs).
68		71
69	=over 4	72	=over 4
70		73
71	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
72		75
73	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
74		77
75	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
76	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
77		81
78	=item on_eof => $cb->($handle)	82	=item on_eof => $cb->($handle)
79		83
80	Set the callback to be called when an end-of-file condition is detected,	84	Set the callback to be called when an end-of-file condition is detected,
81	i.e. in the case of a socket, when the other side has closed the	85	i.e. in the case of a socket, when the other side has closed the
82	connection cleanly.	86	connection cleanly.
83		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the EOF
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
84	While not mandatory, it is highly recommended to set an eof callback,	93	While not mandatory, it is I<highly> recommended to set an EOF callback,
85	otherwise you might end up with a closed socket while you are still	94	otherwise you might end up with a closed socket while you are still
86	waiting for data.	95	waiting for data.
		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
87		99
88	=item on_error => $cb->($handle, $fatal)	100	=item on_error => $cb->($handle, $fatal)
89		101
90	This is the error callback, which is called when, well, some error	102	This is the error callback, which is called when, well, some error
91	occured, such as not being able to resolve the hostname, failure to	103	occured, such as not being able to resolve the hostname, failure to
92	connect or a read error.	104	connect or a read error.
93		105
94	Some errors are fatal (which is indicated by C<$fatal> being true). On	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
95	fatal errors the handle object will be shut down and will not be	107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
		111
96	usable. Non-fatal errors can be retried by simply returning, but it is	112	Non-fatal errors can be retried by simply returning, but it is recommended
97	recommended to simply ignore this parameter and instead abondon the handle	113	to simply ignore this parameter and instead abondon the handle object
98	object when this callback is invoked.	114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
99		116
100	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
101	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
102		119
103	While not mandatory, it is I<highly> recommended to set this callback, as	120	While not mandatory, it is I<highly> recommended to set this callback, as
…		…
110	and no read request is in the queue (unlike read queue callbacks, this	127	and no read request is in the queue (unlike read queue callbacks, this
111	callback will only be called when at least one octet of data is in the	128	callback will only be called when at least one octet of data is in the
112	read buffer).	129	read buffer).
113		130
114	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
115	method or access the C<$handle->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly. Note that you
		133	must not enlarge or modify the read buffer, you can only remove data at
		134	the beginning from it.
116		135
117	When an EOF condition is detected then AnyEvent::Handle will first try to	136	When an EOF condition is detected then AnyEvent::Handle will first try to
118	feed all the remaining data to the queued callbacks and C<on_read> before	137	feed all the remaining data to the queued callbacks and C<on_read> before
119	calling the C<on_eof> callback. If no progress can be made, then a fatal	138	calling the C<on_eof> callback. If no progress can be made, then a fatal
120	error will be raised (with C<$!> set to C<EPIPE>).	139	error will be raised (with C<$!> set to C<EPIPE>).
…		…
135	=item timeout => $fractional_seconds	154	=item timeout => $fractional_seconds
136		155
137	If non-zero, then this enables an "inactivity" timeout: whenever this many	156	If non-zero, then this enables an "inactivity" timeout: whenever this many
138	seconds pass without a successful read or write on the underlying file	157	seconds pass without a successful read or write on the underlying file
139	handle, the C<on_timeout> callback will be invoked (and if that one is	158	handle, the C<on_timeout> callback will be invoked (and if that one is
140	missing, an C<ETIMEDOUT> error will be raised).	159	missing, a non-fatal C<ETIMEDOUT> error will be raised).
141		160
142	Note that timeout processing is also active when you currently do not have	161	Note that timeout processing is also active when you currently do not have
143	any outstanding read or write requests: If you plan to keep the connection	162	any outstanding read or write requests: If you plan to keep the connection
144	idle then you should disable the timout temporarily or ignore the timeout	163	idle then you should disable the timout temporarily or ignore the timeout
145	in the C<on_timeout> callback.	164	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		165	restart the timeout.
146		166
147	Zero (the default) disables this timeout.	167	Zero (the default) disables this timeout.
148		168
149	=item on_timeout => $cb->($handle)	169	=item on_timeout => $cb->($handle)
150		170
…		…
154		174
155	=item rbuf_max => <bytes>	175	=item rbuf_max => <bytes>
156		176
157	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	177	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
158	when the read buffer ever (strictly) exceeds this size. This is useful to	178	when the read buffer ever (strictly) exceeds this size. This is useful to
159	avoid denial-of-service attacks.	179	avoid some forms of denial-of-service attacks.
160		180
161	For example, a server accepting connections from untrusted sources should	181	For example, a server accepting connections from untrusted sources should
162	be configured to accept only so-and-so much data that it cannot act on	182	be configured to accept only so-and-so much data that it cannot act on
163	(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
164	amount of data without a callback ever being called as long as the line	184	amount of data without a callback ever being called as long as the line
165	isn't finished).	185	isn't finished).
166		186
167	=item autocork => <boolean>	187	=item autocork => <boolean>
168		188
169	When disabled (the default), then C<push_write> will try to immediately	189	When disabled (the default), then C<push_write> will try to immediately
170	write the data to the handle if possible. This avoids having to register	190	write the data to the handle, if possible. This avoids having to register
171	a write watcher and wait for the next event loop iteration, but can be	191	a write watcher and wait for the next event loop iteration, but can
172	inefficient if you write multiple small chunks (this disadvantage is	192	be inefficient if you write multiple small chunks (on the wire, this
173	usually avoided by your kernel's nagle algorithm, see C<low_delay>).	193	disadvantage is usually avoided by your kernel's nagle algorithm, see
		194	C<no_delay>, but this option can save costly syscalls).
174		195
175	When enabled, then writes will always be queued till the next event loop	196	When enabled, then writes will always be queued till the next event loop
176	iteration. This is efficient when you do many small writes per iteration,	197	iteration. This is efficient when you do many small writes per iteration,
177	but less efficient when you do a single write only.	198	but less efficient when you do a single write only per iteration (or when
		199	the write buffer often is full). It also increases write latency.
178		200
179	=item no_delay => <boolean>	201	=item no_delay => <boolean>
180		202
181	When doing small writes on sockets, your operating system kernel might	203	When doing small writes on sockets, your operating system kernel might
182	wait a bit for more data before actually sending it out. This is called	204	wait a bit for more data before actually sending it out. This is called
183	the Nagle algorithm, and usually it is beneficial.	205	the Nagle algorithm, and usually it is beneficial.
184		206
185	In some situations you want as low a delay as possible, which cna be	207	In some situations you want as low a delay as possible, which can be
186	accomplishd by setting this option to true.	208	accomplishd by setting this option to a true value.
187		209
188	The default is your opertaing system's default behaviour, this option	210	The default is your opertaing system's default behaviour (most likely
189	explicitly enables or disables it, if possible.	211	enabled), this option explicitly enables or disables it, if possible.
190		212
191	=item read_size => <bytes>	213	=item read_size => <bytes>
192		214
193	The default read block size (the amount of bytes this module will try to read	215	The default read block size (the amount of bytes this module will
194	during each (loop iteration). Default: C<8192>.	216	try to read during each loop iteration, which affects memory
		217	requirements). Default: C<8192>.
195		218
196	=item low_water_mark => <bytes>	219	=item low_water_mark => <bytes>
197		220
198	Sets the amount of bytes (default: C<0>) that make up an "empty" write	221	Sets the amount of bytes (default: C<0>) that make up an "empty" write
199	buffer: If the write reaches this size or gets even samller it is	222	buffer: If the write reaches this size or gets even samller it is
200	considered empty.	223	considered empty.
201		224
		225	Sometimes it can be beneficial (for performance reasons) to add data to
		226	the write buffer before it is fully drained, but this is a rare case, as
		227	the operating system kernel usually buffers data as well, so the default
		228	is good in almost all cases.
		229
202	=item linger => <seconds>	230	=item linger => <seconds>
203		231
204	If non-zero (default: C<3600>), then the destructor of the	232	If non-zero (default: C<3600>), then the destructor of the
205	AnyEvent::Handle object will check wether there is still outstanding write	233	AnyEvent::Handle object will check whether there is still outstanding
206	data and will install a watcher that will write out this data. No errors	234	write data and will install a watcher that will write this data to the
207	will be reported (this mostly matches how the operating system treats	235	socket. No errors will be reported (this mostly matches how the operating
208	outstanding data at socket close time).	236	system treats outstanding data at socket close time).
209		237
210	This will not work for partial TLS data that could not yet been	238	This will not work for partial TLS data that could not be encoded
211	encoded. This data will be lost.	239	yet. This data will be lost. Calling the C<stoptls> method in time might
		240	help.
		241
		242	=item common_name => $string
		243
		244	The common name used by some verification methods (most notably SSL/TLS)
		245	associated with this connection. Usually this is the remote hostname used
		246	to connect, but can be almost anything.
212		247
213	=item tls => "accept" \| "connect" \| Net::SSLeay::SSL object	248	=item tls => "accept" \| "connect" \| Net::SSLeay::SSL object
214		249
215	When this parameter is given, it enables TLS (SSL) mode, that means it	250	When this parameter is given, it enables TLS (SSL) mode, that means
216	will start making tls handshake and will transparently encrypt/decrypt	251	AnyEvent will start a TLS handshake as soon as the conenction has been
217	data.	252	established and will transparently encrypt/decrypt data afterwards.
218		253
219	TLS mode requires Net::SSLeay to be installed (it will be loaded	254	TLS mode requires Net::SSLeay to be installed (it will be loaded
220	automatically when you try to create a TLS handle).	255	automatically when you try to create a TLS handle): this module doesn't
		256	have a dependency on that module, so if your module requires it, you have
		257	to add the dependency yourself.
221		258
222	For the TLS server side, use C<accept>, and for the TLS client side of a	259	Unlike TCP, TLS has a server and client side: for the TLS server side, use
223	connection, use C<connect> mode.	260	C<accept>, and for the TLS client side of a connection, use C<connect>
		261	mode.
224		262
225	You can also provide your own TLS connection object, but you have	263	You can also provide your own TLS connection object, but you have
226	to make sure that you call either C<Net::SSLeay::set_connect_state>	264	to make sure that you call either C<Net::SSLeay::set_connect_state>
227	or C<Net::SSLeay::set_accept_state> on it before you pass it to	265	or C<Net::SSLeay::set_accept_state> on it before you pass it to
228	AnyEvent::Handle.	266	AnyEvent::Handle. Also, this module will take ownership of this connection
		267	object.
229		268
		269	At some future point, AnyEvent::Handle might switch to another TLS
		270	implementation, then the option to use your own session object will go
		271	away.
		272
		273	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		274	passing in the wrong integer will lead to certain crash. This most often
		275	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		276	segmentation fault.
		277
230	See the C<starttls> method if you need to start TLS negotiation later.	278	See the C<< ->starttls >> method for when need to start TLS negotiation later.
231		279
232	=item tls_ctx => $ssl_ctx	280	=item tls_ctx => $anyevent_tls
233		281
234	Use the given Net::SSLeay::CTX object to create the new TLS connection	282	Use the given C<AnyEvent::TLS> object to create the new TLS connection
235	(unless a connection object was specified directly). If this parameter is	283	(unless a connection object was specified directly). If this parameter is
236	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	284	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
237		285
		286	Instead of an object, you can also specify a hash reference with C<< key
		287	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		288	new TLS context object.
		289
238	=item json => JSON or JSON::XS object	290	=item json => JSON or JSON::XS object
239		291
240	This is the json coder object used by the C<json> read and write types.	292	This is the json coder object used by the C<json> read and write types.
241		293
242	If you don't supply it, then AnyEvent::Handle will create and use a	294	If you don't supply it, then AnyEvent::Handle will create and use a
243	suitable one, which will write and expect UTF-8 encoded JSON texts.	295	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		296	texts.
244		297
245	Note that you are responsible to depend on the JSON module if you want to	298	Note that you are responsible to depend on the JSON module if you want to
246	use this functionality, as AnyEvent does not have a dependency itself.	299	use this functionality, as AnyEvent does not have a dependency itself.
247		300
248	=item filter_r => $cb
249
250	=item filter_w => $cb
251
252	These exist, but are undocumented at this time.
253
254	=back	301	=back
255		302
256	=cut	303	=cut
257		304
258	sub new {	305	sub new {
259	my $class = shift;	306	my $class = shift;
260
261	my $self = bless { @_ }, $class;	307	my $self = bless { @_ }, $class;
262		308
263	$self->{fh} or Carp::croak "mandatory argument fh is missing";	309	$self->{fh} or Carp::croak "mandatory argument fh is missing";
264		310
265	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	311	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
266
267	if ($self->{tls}) {
268	require Net::SSLeay;
269	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
270	}
271		312
272	$self->{_activity} = AnyEvent->now;	313	$self->{_activity} = AnyEvent->now;
273	$self->_timeout;	314	$self->_timeout;
274		315
		316	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		317
		318	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		319	if $self->{tls};
		320
275	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	321	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
276	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
277		322
278	$self->start_read	323	$self->start_read
279	if $self->{on_read};	324	if $self->{on_read};
280		325
281	$self	326	$self->{fh} && $self
282	}	327	}
283		328
284	sub _shutdown {	329	sub _shutdown {
285	my ($self) = @_;	330	my ($self) = @_;
286		331
287	delete $self->{_tw};	332	delete @$self{qw(_tw _rw _ww fh rbuf wbuf on_read _queue)};
288	delete $self->{_rw};	333	$self->{_eof} = 1; # tell starttls et. al to stop trying
289	delete $self->{_ww};
290	delete $self->{fh};
291		334
292	$self->stoptls;	335	&_freetls;
293	}	336	}
294		337
295	sub _error {	338	sub _error {
296	my ($self, $errno, $fatal) = @_;	339	my ($self, $errno, $fatal) = @_;
297		340
…		…
300		343
301	$! = $errno;	344	$! = $errno;
302		345
303	if ($self->{on_error}) {	346	if ($self->{on_error}) {
304	$self->{on_error}($self, $fatal);	347	$self->{on_error}($self, $fatal);
305	} else {	348	} elsif ($self->{fh}) {
306	Carp::croak "AnyEvent::Handle uncaught error: $!";	349	Carp::croak "AnyEvent::Handle uncaught error: $!";
307	}	350	}
308	}	351	}
309		352
310	=item $fh = $handle->fh	353	=item $fh = $handle->fh
311		354
312	This method returns the file handle of the L<AnyEvent::Handle> object.	355	This method returns the file handle used to create the L<AnyEvent::Handle> object.
313		356
314	=cut	357	=cut
315		358
316	sub fh { $_[0]{fh} }	359	sub fh { $_[0]{fh} }
317		360
…		…
335	$_[0]{on_eof} = $_[1];	378	$_[0]{on_eof} = $_[1];
336	}	379	}
337		380
338	=item $handle->on_timeout ($cb)	381	=item $handle->on_timeout ($cb)
339		382
340	Replace the current C<on_timeout> callback, or disables the callback	383	Replace the current C<on_timeout> callback, or disables the callback (but
341	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor	384	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
342	argument.	385	argument and method.
343		386
344	=cut	387	=cut
345		388
346	sub on_timeout {	389	sub on_timeout {
347	$_[0]{on_timeout} = $_[1];	390	$_[0]{on_timeout} = $_[1];
348	}	391	}
349		392
350	=item $handle->autocork ($boolean)	393	=item $handle->autocork ($boolean)
351		394
352	Enables or disables the current autocork behaviour (see C<autocork>	395	Enables or disables the current autocork behaviour (see C<autocork>
353	constructor argument).	396	constructor argument). Changes will only take effect on the next write.
354		397
355	=cut	398	=cut
		399
		400	sub autocork {
		401	$_[0]{autocork} = $_[1];
		402	}
356		403
357	=item $handle->no_delay ($boolean)	404	=item $handle->no_delay ($boolean)
358		405
359	Enables or disables the C<no_delay> setting (see constructor argument of	406	Enables or disables the C<no_delay> setting (see constructor argument of
360	the same name for details).	407	the same name for details).
…		…
453	my ($self, $cb) = @_;	500	my ($self, $cb) = @_;
454		501
455	$self->{on_drain} = $cb;	502	$self->{on_drain} = $cb;
456		503
457	$cb->($self)	504	$cb->($self)
458	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	505	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
459	}	506	}
460		507
461	=item $handle->push_write ($data)	508	=item $handle->push_write ($data)
462		509
463	Queues the given scalar to be written. You can push as much data as you	510	Queues the given scalar to be written. You can push as much data as you
…		…
480	substr $self->{wbuf}, 0, $len, "";	527	substr $self->{wbuf}, 0, $len, "";
481		528
482	$self->{_activity} = AnyEvent->now;	529	$self->{_activity} = AnyEvent->now;
483		530
484	$self->{on_drain}($self)	531	$self->{on_drain}($self)
485	if $self->{low_water_mark} >= length $self->{wbuf}	532	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
486	&& $self->{on_drain};	533	&& $self->{on_drain};
487		534
488	delete $self->{_ww} unless length $self->{wbuf};	535	delete $self->{_ww} unless length $self->{wbuf};
489	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	536	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
490	$self->_error ($!, 1);	537	$self->_error ($!, 1);
…		…
514		561
515	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	562	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
516	->($self, @_);	563	->($self, @_);
517	}	564	}
518		565
519	if ($self->{filter_w}) {	566	if ($self->{tls}) {
520	$self->{filter_w}($self, \$_[0]);	567	$self->{_tls_wbuf} .= $_[0];
		568
		569	&_dotls ($self);
521	} else {	570	} else {
522	$self->{wbuf} .= $_[0];	571	$self->{wbuf} .= $_[0];
523	$self->_drain_wbuf;	572	$self->_drain_wbuf;
524	}	573	}
525	}	574	}
…		…
542	=cut	591	=cut
543		592
544	register_write_type netstring => sub {	593	register_write_type netstring => sub {
545	my ($self, $string) = @_;	594	my ($self, $string) = @_;
546		595
547	sprintf "%d:%s,", (length $string), $string	596	(length $string) . ":$string,"
548	};	597	};
549		598
550	=item packstring => $format, $data	599	=item packstring => $format, $data
551		600
552	An octet string prefixed with an encoded length. The encoding C<$format>	601	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
726		775
727	if (	776	if (
728	defined $self->{rbuf_max}	777	defined $self->{rbuf_max}
729	&& $self->{rbuf_max} < length $self->{rbuf}	778	&& $self->{rbuf_max} < length $self->{rbuf}
730	) {	779	) {
731	return $self->_error (&Errno::ENOSPC, 1);	780	$self->_error (&Errno::ENOSPC, 1), return;
732	}	781	}
733		782
734	while () {	783	while () {
		784	# we need to use a separate tls read buffer, as we must not receive data while
		785	# we are draining the buffer, and this can only happen with TLS.
		786	$self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
		787
735	my $len = length $self->{rbuf};	788	my $len = length $self->{rbuf};
736		789
737	if (my $cb = shift @{ $self->{_queue} }) {	790	if (my $cb = shift @{ $self->{_queue} }) {
738	unless ($cb->($self)) {	791	unless ($cb->($self)) {
739	if ($self->{_eof}) {	792	if ($self->{_eof}) {
740	# no progress can be made (not enough data and no data forthcoming)	793	# no progress can be made (not enough data and no data forthcoming)
741	$self->_error (&Errno::EPIPE, 1), last;	794	$self->_error (&Errno::EPIPE, 1), return;
742	}	795	}
743		796
744	unshift @{ $self->{_queue} }, $cb;	797	unshift @{ $self->{_queue} }, $cb;
745	last;	798	last;
746	}	799	}
…		…
754	&& !@{ $self->{_queue} } # and the queue is still empty	807	&& !@{ $self->{_queue} } # and the queue is still empty
755	&& $self->{on_read} # but we still have on_read	808	&& $self->{on_read} # but we still have on_read
756	) {	809	) {
757	# no further data will arrive	810	# no further data will arrive
758	# so no progress can be made	811	# so no progress can be made
759	$self->_error (&Errno::EPIPE, 1), last	812	$self->_error (&Errno::EPIPE, 1), return
760	if $self->{_eof};	813	if $self->{_eof};
761		814
762	last; # more data might arrive	815	last; # more data might arrive
763	}	816	}
764	} else {	817	} else {
765	# read side becomes idle	818	# read side becomes idle
766	delete $self->{_rw};	819	delete $self->{_rw} unless $self->{tls};
767	last;	820	last;
768	}	821	}
769	}	822	}
770		823
		824	if ($self->{_eof}) {
		825	if ($self->{on_eof}) {
771	$self->{on_eof}($self)	826	$self->{on_eof}($self)
772	if $self->{_eof} && $self->{on_eof};	827	} else {
		828	$self->_error (0, 1);
		829	}
		830	}
773		831
774	# may need to restart read watcher	832	# may need to restart read watcher
775	unless ($self->{_rw}) {	833	unless ($self->{_rw}) {
776	$self->start_read	834	$self->start_read
777	if $self->{on_read} \|\| @{ $self->{_queue} };	835	if $self->{on_read} \|\| @{ $self->{_queue} };
…		…
795		853
796	=item $handle->rbuf	854	=item $handle->rbuf
797		855
798	Returns the read buffer (as a modifiable lvalue).	856	Returns the read buffer (as a modifiable lvalue).
799		857
800	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	858	You can access the read buffer directly as the C<< ->{rbuf} >>
801	you want.	859	member, if you want. However, the only operation allowed on the
		860	read buffer (apart from looking at it) is removing data from its
		861	beginning. Otherwise modifying or appending to it is not allowed and will
		862	lead to hard-to-track-down bugs.
802		863
803	NOTE: The read buffer should only be used or modified if the C<on_read>,	864	NOTE: The read buffer should only be used or modified if the C<on_read>,
804	C<push_read> or C<unshift_read> methods are used. The other read methods	865	C<push_read> or C<unshift_read> methods are used. The other read methods
805	automatically manage the read buffer.	866	automatically manage the read buffer.
806		867
…		…
1061	An octet string prefixed with an encoded length. The encoding C<$format>	1122	An octet string prefixed with an encoded length. The encoding C<$format>
1062	uses the same format as a Perl C<pack> format, but must specify a single	1123	uses the same format as a Perl C<pack> format, but must specify a single
1063	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1124	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1064	optional C<!>, C<< < >> or C<< > >> modifier).	1125	optional C<!>, C<< < >> or C<< > >> modifier).
1065		1126
1066	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.	1127	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1128	EPP uses a prefix of C<N> (4 octtes).
1067		1129
1068	Example: read a block of data prefixed by its length in BER-encoded	1130	Example: read a block of data prefixed by its length in BER-encoded
1069	format (very efficient).	1131	format (very efficient).
1070		1132
1071	$handle->push_read (packstring => "w", sub {	1133	$handle->push_read (packstring => "w", sub {
…		…
1101	}	1163	}
1102	};	1164	};
1103		1165
1104	=item json => $cb->($handle, $hash_or_arrayref)	1166	=item json => $cb->($handle, $hash_or_arrayref)
1105		1167
1106	Reads a JSON object or array, decodes it and passes it to the callback.	1168	Reads a JSON object or array, decodes it and passes it to the
		1169	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1107		1170
1108	If a C<json> object was passed to the constructor, then that will be used	1171	If a C<json> object was passed to the constructor, then that will be used
1109	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1172	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1110		1173
1111	This read type uses the incremental parser available with JSON version	1174	This read type uses the incremental parser available with JSON version
…		…
1128	my $rbuf = \$self->{rbuf};	1191	my $rbuf = \$self->{rbuf};
1129		1192
1130	my $json = $self->{json} \|\|= JSON->new->utf8;	1193	my $json = $self->{json} \|\|= JSON->new->utf8;
1131		1194
1132	sub {	1195	sub {
1133	my $ref = $json->incr_parse ($self->{rbuf});	1196	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1134		1197
1135	if ($ref) {	1198	if ($ref) {
1136	$self->{rbuf} = $json->incr_text;	1199	$self->{rbuf} = $json->incr_text;
1137	$json->incr_text = "";	1200	$json->incr_text = "";
1138	$cb->($self, $ref);	1201	$cb->($self, $ref);
1139		1202
1140	1	1203	1
		1204	} elsif ($@) {
		1205	# error case
		1206	$json->incr_skip;
		1207
		1208	$self->{rbuf} = $json->incr_text;
		1209	$json->incr_text = "";
		1210
		1211	$self->_error (&Errno::EBADMSG);
		1212
		1213	()
1141	} else {	1214	} else {
1142	$self->{rbuf} = "";	1215	$self->{rbuf} = "";
		1216
1143	()	1217	()
1144	}	1218	}
1145	}	1219	}
1146	};	1220	};
1147		1221
…		…
1224	Note that AnyEvent::Handle will automatically C<start_read> for you when	1298	Note that AnyEvent::Handle will automatically C<start_read> for you when
1225	you change the C<on_read> callback or push/unshift a read callback, and it	1299	you change the C<on_read> callback or push/unshift a read callback, and it
1226	will automatically C<stop_read> for you when neither C<on_read> is set nor	1300	will automatically C<stop_read> for you when neither C<on_read> is set nor
1227	there are any read requests in the queue.	1301	there are any read requests in the queue.
1228		1302
		1303	These methods will have no effect when in TLS mode (as TLS doesn't support
		1304	half-duplex connections).
		1305
1229	=cut	1306	=cut
1230		1307
1231	sub stop_read {	1308	sub stop_read {
1232	my ($self) = @_;	1309	my ($self) = @_;
1233		1310
1234	delete $self->{_rw};	1311	delete $self->{_rw} unless $self->{tls};
1235	}	1312	}
1236		1313
1237	sub start_read {	1314	sub start_read {
1238	my ($self) = @_;	1315	my ($self) = @_;
1239		1316
1240	unless ($self->{_rw} \|\| $self->{_eof}) {	1317	unless ($self->{_rw} \|\| $self->{_eof}) {
1241	Scalar::Util::weaken $self;	1318	Scalar::Util::weaken $self;
1242		1319
1243	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1320	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1244	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1321	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1245	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} \|\| 8192, length $$rbuf;	1322	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} \|\| 8192, length $$rbuf;
1246		1323
1247	if ($len > 0) {	1324	if ($len > 0) {
1248	$self->{_activity} = AnyEvent->now;	1325	$self->{_activity} = AnyEvent->now;
1249		1326
1250	$self->{filter_r}	1327	if ($self->{tls}) {
1251	? $self->{filter_r}($self, $rbuf)	1328	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1252	: $self->{_in_drain} \|\| $self->_drain_rbuf;	1329
		1330	&_dotls ($self);
		1331	} else {
		1332	$self->_drain_rbuf unless $self->{_in_drain};
		1333	}
1253		1334
1254	} elsif (defined $len) {	1335	} elsif (defined $len) {
1255	delete $self->{_rw};	1336	delete $self->{_rw};
1256	$self->{_eof} = 1;	1337	$self->{_eof} = 1;
1257	$self->_drain_rbuf unless $self->{_in_drain};	1338	$self->_drain_rbuf unless $self->{_in_drain};
…		…
1261	}	1342	}
1262	});	1343	});
1263	}	1344	}
1264	}	1345	}
1265		1346
		1347	# poll the write BIO and send the data if applicable
1266	sub _dotls {	1348	sub _dotls {
1267	my ($self) = @_;	1349	my ($self) = @_;
1268		1350
1269	my $buf;	1351	my $tmp;
1270		1352
1271	if (length $self->{_tls_wbuf}) {	1353	if (length $self->{_tls_wbuf}) {
1272	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1354	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1273	substr $self->{_tls_wbuf}, 0, $len, "";	1355	substr $self->{_tls_wbuf}, 0, $tmp, "";
1274	}	1356	}
1275	}	1357	}
1276		1358
1277	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1278	$self->{wbuf} .= $buf;
1279	$self->_drain_wbuf;
1280	}
1281
1282	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1359	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1283	if (length $buf) {	1360	unless (length $tmp) {
1284	$self->{rbuf} .= $buf;
1285	$self->_drain_rbuf unless $self->{_in_drain};
1286	} else {
1287	# let's treat SSL-eof as we treat normal EOF	1361	# let's treat SSL-eof as we treat normal EOF
		1362	delete $self->{_rw};
1288	$self->{_eof} = 1;	1363	$self->{_eof} = 1;
1289	$self->_shutdown;	1364	&_freetls;
1290	return;
1291	}	1365	}
1292	}
1293		1366
		1367	$self->{_tls_rbuf} .= $tmp;
		1368	$self->_drain_rbuf unless $self->{_in_drain};
		1369	$self->{tls} or return; # tls session might have gone away in callback
		1370	}
		1371
1294	my $err = Net::SSLeay::get_error ($self->{tls}, -1);	1372	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1295		1373
1296	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {	1374	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1297	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {	1375	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1298	return $self->_error ($!, 1);	1376	return $self->_error ($!, 1);
1299	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {	1377	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1300	return $self->_error (&Errno::EIO, 1);	1378	return $self->_error (&Errno::EIO, 1);
1301	}	1379	}
1302		1380
1303	# all others are fine for our purposes	1381	# all other errors are fine for our purposes
		1382	}
		1383
		1384	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1385	$self->{wbuf} .= $tmp;
		1386	$self->_drain_wbuf;
1304	}	1387	}
1305	}	1388	}
1306		1389
1307	=item $handle->starttls ($tls[, $tls_ctx])	1390	=item $handle->starttls ($tls[, $tls_ctx])
1308		1391
…		…
1311	C<starttls>.	1394	C<starttls>.
1312		1395
1313	The first argument is the same as the C<tls> constructor argument (either	1396	The first argument is the same as the C<tls> constructor argument (either
1314	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1397	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1315		1398
1316	The second argument is the optional C<Net::SSLeay::CTX> object that is	1399	The second argument is the optional C<AnyEvent::TLS> object that is used
1317	used when AnyEvent::Handle has to create its own TLS connection object.	1400	when AnyEvent::Handle has to create its own TLS connection object, or
		1401	a hash reference with C<< key => value >> pairs that will be used to
		1402	construct a new context.
1318		1403
1319	The TLS connection object will end up in C<< $handle->{tls} >> after this	1404	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1320	call and can be used or changed to your liking. Note that the handshake	1405	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1321	might have already started when this function returns.	1406	changed to your liking. Note that the handshake might have already started
		1407	when this function returns.
		1408
		1409	If it an error to start a TLS handshake more than once per
		1410	AnyEvent::Handle object (this is due to bugs in OpenSSL).
1322		1411
1323	=cut	1412	=cut
1324		1413
1325	sub starttls {	1414	sub starttls {
1326	my ($self, $ssl, $ctx) = @_;	1415	my ($self, $ssl, $ctx) = @_;
1327		1416
1328	$self->stoptls;	1417	require Net::SSLeay;
1329		1418
1330	if ($ssl eq "accept") {	1419	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1331	$ssl = Net::SSLeay::new ($ctx \|\| TLS_CTX ());	1420	if $self->{tls};
1332	Net::SSLeay::set_accept_state ($ssl);	1421
1333	} elsif ($ssl eq "connect") {	1422	$ctx \|\|= $self->{tls_ctx};
1334	$ssl = Net::SSLeay::new ($ctx \|\| TLS_CTX ());	1423
1335	Net::SSLeay::set_connect_state ($ssl);	1424	if ("HASH" eq ref $ctx) {
		1425	require AnyEvent::TLS;
		1426
		1427	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
		1428	$ctx = new AnyEvent::TLS %$ctx;
		1429	}
1336	}	1430
1337		1431	$self->{tls_ctx} = $ctx \|\| TLS_CTX ();
1338	$self->{tls} = $ssl;	1432	$self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self);
1339		1433
1340	# basically, this is deep magic (because SSL_read should have the same issues)	1434	# basically, this is deep magic (because SSL_read should have the same issues)
1341	# but the openssl maintainers basically said: "trust us, it just works".	1435	# but the openssl maintainers basically said: "trust us, it just works".
1342	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1436	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1343	# and mismaintained ssleay-module doesn't even offer them).	1437	# and mismaintained ssleay-module doesn't even offer them).
1344	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1438	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1439	#
		1440	# in short: this is a mess.
		1441	#
		1442	# note that we do not try to keep the length constant between writes as we are required to do.
		1443	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1444	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1445	# have identity issues in that area.
1345	Net::SSLeay::CTX_set_mode ($self->{tls},	1446	# Net::SSLeay::CTX_set_mode ($ssl,
1346	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } \|\| 1)	1447	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } \|\| 1)
1347	\| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } \|\| 2));	1448	# \| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } \|\| 2));
		1449	Net::SSLeay::CTX_set_mode ($ssl, 1\|2);
1348		1450
1349	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1451	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1350	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1452	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1351		1453
1352	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	1454	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1353		1455
1354	$self->{filter_w} = sub {	1456	&_dotls; # need to trigger the initial handshake
1355	$_[0]{_tls_wbuf} .= ${$_[1]};	1457	$self->start_read; # make sure we actually do read
1356	&_dotls;
1357	};
1358	$self->{filter_r} = sub {
1359	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1360	&_dotls;
1361	};
1362	}	1458	}
1363		1459
1364	=item $handle->stoptls	1460	=item $handle->stoptls
1365		1461
1366	Destroys the SSL connection, if any. Partial read or write data will be	1462	Shuts down the SSL connection - this makes a proper EOF handshake by
1367	lost.	1463	sending a close notify to the other side, but since OpenSSL doesn't
		1464	support non-blocking shut downs, it is not possible to re-use the stream
		1465	afterwards.
1368		1466
1369	=cut	1467	=cut
1370		1468
1371	sub stoptls {	1469	sub stoptls {
1372	my ($self) = @_;	1470	my ($self) = @_;
1373		1471
1374	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	1472	if ($self->{tls}) {
		1473	Net::SSLeay::shutdown ($self->{tls});
1375		1474
1376	delete $self->{_rbio};	1475	&_dotls;
1377	delete $self->{_wbio};	1476
1378	delete $self->{_tls_wbuf};	1477	# we don't give a shit. no, we do, but we can't. no...
1379	delete $self->{filter_r};	1478	# we, we... have to use openssl :/
1380	delete $self->{filter_w};	1479	&_freetls;
		1480	}
		1481	}
		1482
		1483	sub _freetls {
		1484	my ($self) = @_;
		1485
		1486	return unless $self->{tls};
		1487
		1488	$self->{tls_ctx}->_put_session (delete $self->{tls});
		1489
		1490	delete @$self{qw(_rbio _wbio _tls_wbuf)};
1381	}	1491	}
1382		1492
1383	sub DESTROY {	1493	sub DESTROY {
1384	my $self = shift;	1494	my ($self) = @_;
1385		1495
1386	$self->stoptls;	1496	&_freetls;
1387		1497
1388	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	1498	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1389		1499
1390	if ($linger && length $self->{wbuf}) {	1500	if ($linger && length $self->{wbuf}) {
1391	my $fh = delete $self->{fh};	1501	my $fh = delete $self->{fh};
…		…
1406	@linger = ();	1516	@linger = ();
1407	});	1517	});
1408	}	1518	}
1409	}	1519	}
1410		1520
		1521	=item $handle->destroy
		1522
		1523	Shuts down the handle object as much as possible - this call ensures that
		1524	no further callbacks will be invoked and resources will be freed as much
		1525	as possible. You must not call any methods on the object afterwards.
		1526
		1527	Normally, you can just "forget" any references to an AnyEvent::Handle
		1528	object and it will simply shut down. This works in fatal error and EOF
		1529	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1530	callback, so when you want to destroy the AnyEvent::Handle object from
		1531	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1532	that case.
		1533
		1534	The handle might still linger in the background and write out remaining
		1535	data, as specified by the C<linger> option, however.
		1536
		1537	=cut
		1538
		1539	sub destroy {
		1540	my ($self) = @_;
		1541
		1542	$self->DESTROY;
		1543	%$self = ();
		1544	}
		1545
1411	=item AnyEvent::Handle::TLS_CTX	1546	=item AnyEvent::Handle::TLS_CTX
1412		1547
1413	This function creates and returns the Net::SSLeay::CTX object used by	1548	This function creates and returns the AnyEvent::TLS object used by default
1414	default for TLS mode.	1549	for TLS mode.
1415		1550
1416	The context is created like this:	1551	The context is created by calling L<AnyEvent::TLS> without any arguments.
1417
1418	Net::SSLeay::load_error_strings;
1419	Net::SSLeay::SSLeay_add_ssl_algorithms;
1420	Net::SSLeay::randomize;
1421
1422	my $CTX = Net::SSLeay::CTX_new;
1423
1424	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1425		1552
1426	=cut	1553	=cut
1427		1554
1428	our $TLS_CTX;	1555	our $TLS_CTX;
1429		1556
1430	sub TLS_CTX() {	1557	sub TLS_CTX() {
1431	$TLS_CTX \|\| do {	1558	$TLS_CTX \|\|= do {
1432	require Net::SSLeay;	1559	require AnyEvent::TLS;
1433		1560
1434	Net::SSLeay::load_error_strings ();	1561	new AnyEvent::TLS
1435	Net::SSLeay::SSLeay_add_ssl_algorithms ();
1436	Net::SSLeay::randomize ();
1437
1438	$TLS_CTX = Net::SSLeay::CTX_new ();
1439
1440	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1441
1442	$TLS_CTX
1443	}	1562	}
1444	}	1563	}
1445		1564
1446	=back	1565	=back
		1566
		1567
		1568	=head1 NONFREQUENTLY ASKED QUESTIONS
		1569
		1570	=over 4
		1571
		1572	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1573	still get further invocations!
		1574
		1575	That's because AnyEvent::Handle keeps a reference to itself when handling
		1576	read or write callbacks.
		1577
		1578	It is only safe to "forget" the reference inside EOF or error callbacks,
		1579	from within all other callbacks, you need to explicitly call the C<<
		1580	->destroy >> method.
		1581
		1582	=item I get different callback invocations in TLS mode/Why can't I pause
		1583	reading?
		1584
		1585	Unlike, say, TCP, TLS connections do not consist of two independent
		1586	communication channels, one for each direction. Or put differently. The
		1587	read and write directions are not independent of each other: you cannot
		1588	write data unless you are also prepared to read, and vice versa.
		1589
		1590	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1591	callback invocations when you are not expecting any read data - the reason
		1592	is that AnyEvent::Handle always reads in TLS mode.
		1593
		1594	During the connection, you have to make sure that you always have a
		1595	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1596	connection (or when you no longer want to use it) you can call the
		1597	C<destroy> method.
		1598
		1599	=item How do I read data until the other side closes the connection?
		1600
		1601	If you just want to read your data into a perl scalar, the easiest way
		1602	to achieve this is by setting an C<on_read> callback that does nothing,
		1603	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1604	will be in C<$_[0]{rbuf}>:
		1605
		1606	$handle->on_read (sub { });
		1607	$handle->on_eof (undef);
		1608	$handle->on_error (sub {
		1609	my $data = delete $_[0]{rbuf};
		1610	undef $handle;
		1611	});
		1612
		1613	The reason to use C<on_error> is that TCP connections, due to latencies
		1614	and packets loss, might get closed quite violently with an error, when in
		1615	fact, all data has been received.
		1616
		1617	It is usually better to use acknowledgements when transferring data,
		1618	to make sure the other side hasn't just died and you got the data
		1619	intact. This is also one reason why so many internet protocols have an
		1620	explicit QUIT command.
		1621
		1622	=item I don't want to destroy the handle too early - how do I wait until
		1623	all data has been written?
		1624
		1625	After writing your last bits of data, set the C<on_drain> callback
		1626	and destroy the handle in there - with the default setting of
		1627	C<low_water_mark> this will be called precisely when all data has been
		1628	written to the socket:
		1629
		1630	$handle->push_write (...);
		1631	$handle->on_drain (sub {
		1632	warn "all data submitted to the kernel\n";
		1633	undef $handle;
		1634	});
		1635
		1636	=back
		1637
1447		1638
1448	=head1 SUBCLASSING AnyEvent::Handle	1639	=head1 SUBCLASSING AnyEvent::Handle
1449		1640
1450	In many cases, you might want to subclass AnyEvent::Handle.	1641	In many cases, you might want to subclass AnyEvent::Handle.
1451		1642

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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents): Revision 1.79 by root, Sun Jul 27 08:37:56 2008 UTC vs. Revision 1.131 by root, Tue Jun 30 22:42:33 2009 UTC

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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.79 by root, Sun Jul 27 08:37:56 2008 UTC vs.
Revision 1.131 by root, Tue Jun 30 22:42:33 2009 UTC