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

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.198 by root, Tue Aug 31 01:03:37 2010 UTC vs.
Revision 1.234 by root, Wed Apr 18 09:44:10 2012 UTC

…		…
11		11
12	my $hdl; $hdl = new AnyEvent::Handle	12	my $hdl; $hdl = new AnyEvent::Handle
13	fh => \*STDIN,	13	fh => \*STDIN,
14	on_error => sub {	14	on_error => sub {
15	my ($hdl, $fatal, $msg) = @_;	15	my ($hdl, $fatal, $msg) = @_;
16	warn "got error $msg\n";	16	AE::log error => $msg;
17	$hdl->destroy;	17	$hdl->destroy;
18	$cv->send;	18	$cv->send;
19	};	19	};
20		20
21	# send some request line	21	# send some request line
22	$hdl->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
23		23
24	# read the response line	24	# read the response line
25	$hdl->push_read (line => sub {	25	$hdl->push_read (line => sub {
26	my ($hdl, $line) = @_;	26	my ($hdl, $line) = @_;
27	warn "got line <$line>\n";	27	say "got line <$line>";
28	$cv->send;	28	$cv->send;
29	});	29	});
30		30
31	$cv->recv;	31	$cv->recv;
32		32
…		…
75	}	75	}
76		76
77	\&$func	77	\&$func
78	}	78	}
79		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
80	=head1 METHODS	82	=head1 METHODS
81		83
82	=over 4	84	=over 4
83		85
84	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
…		…
112	=over 4	114	=over 4
113		115
114	=item on_prepare => $cb->($handle)	116	=item on_prepare => $cb->($handle)
115		117
116	This (rarely used) callback is called before a new connection is	118	This (rarely used) callback is called before a new connection is
117	attempted, but after the file handle has been created. It could be used to	119	attempted, but after the file handle has been created (you can access that
		120	file handle via C<< $handle->{fh} >>). It could be used to prepare the
118	prepare the file handle with parameters required for the actual connect	121	file handle with parameters required for the actual connect (as opposed to
119	(as opposed to settings that can be changed when the connection is already	122	settings that can be changed when the connection is already established).
120	established).
121		123
122	The return value of this callback should be the connect timeout value in	124	The return value of this callback should be the connect timeout value in
123	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the	125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
124	default timeout is to be used).	126	default timeout is to be used).
125		127
126	=item on_connect => $cb->($handle, $host, $port, $retry->())	128	=item on_connect => $cb->($handle, $host, $port, $retry->())
127		129
128	This callback is called when a connection has been successfully established.	130	This callback is called when a connection has been successfully established.
129		131
130	The peer's numeric host and port (the socket peername) are passed as	132	The peer's numeric host and port (the socket peername) are passed as
131	parameters, together with a retry callback.	133	parameters, together with a retry callback. At the time it is called the
		134	read and write queues, EOF status, TLS status and similar properties of
		135	the handle will have been reset.
132		136
		137	It is not allowed to use the read or write queues while the handle object
		138	is connecting.
		139
133	If, for some reason, the handle is not acceptable, calling C<$retry>	140	If, for some reason, the handle is not acceptable, calling C<$retry> will
134	will continue with the next connection target (in case of multi-homed	141	continue with the next connection target (in case of multi-homed hosts or
135	hosts or SRV records there can be multiple connection endpoints). At the	142	SRV records there can be multiple connection endpoints). The C<$retry>
136	time it is called the read and write queues, eof status, tls status and	143	callback can be invoked after the connect callback returns, i.e. one can
137	similar properties of the handle will have been reset.	144	start a handshake and then decide to retry with the next host if the
		145	handshake fails.
138		146
139	In most cases, you should ignore the C<$retry> parameter.	147	In most cases, you should ignore the C<$retry> parameter.
140		148
141	=item on_connect_error => $cb->($handle, $message)	149	=item on_connect_error => $cb->($handle, $message)
142		150
…		…
157		165
158	Some errors are fatal (which is indicated by C<$fatal> being true). On	166	Some errors are fatal (which is indicated by C<$fatal> being true). On
159	fatal errors the handle object will be destroyed (by a call to C<< ->	167	fatal errors the handle object will be destroyed (by a call to C<< ->
160	destroy >>) after invoking the error callback (which means you are free to	168	destroy >>) after invoking the error callback (which means you are free to
161	examine the handle object). Examples of fatal errors are an EOF condition	169	examine the handle object). Examples of fatal errors are an EOF condition
162	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In	170	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
163	cases where the other side can close the connection at will, it is	171	cases where the other side can close the connection at will, it is
164	often easiest to not report C<EPIPE> errors in this callback.	172	often easiest to not report C<EPIPE> errors in this callback.
165		173
166	AnyEvent::Handle tries to find an appropriate error code for you to check	174	AnyEvent::Handle tries to find an appropriate error code for you to check
167	against, but in some cases (TLS errors), this does not work well. It is	175	against, but in some cases (TLS errors), this does not work well.
168	recommended to always output the C<$message> argument in human-readable	176
169	error messages (it's usually the same as C<"$!">).	177	If you report the error to the user, it is recommended to always output
		178	the C<$message> argument in human-readable error messages (you don't need
		179	to report C<"$!"> if you report C<$message>).
		180
		181	If you want to react programmatically to the error, then looking at C<$!>
		182	and comparing it against some of the documented C<Errno> values is usually
		183	better than looking at the C<$message>.
170		184
171	Non-fatal errors can be retried by returning, but it is recommended	185	Non-fatal errors can be retried by returning, but it is recommended
172	to simply ignore this parameter and instead abondon the handle object	186	to simply ignore this parameter and instead abondon the handle object
173	when this callback is invoked. Examples of non-fatal errors are timeouts	187	when this callback is invoked. Examples of non-fatal errors are timeouts
174	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).	188	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
…		…
222	If an EOF condition has been detected but no C<on_eof> callback has been	236	If an EOF condition has been detected but no C<on_eof> callback has been
223	set, then a fatal error will be raised with C<$!> set to <0>.	237	set, then a fatal error will be raised with C<$!> set to <0>.
224		238
225	=item on_drain => $cb->($handle)	239	=item on_drain => $cb->($handle)
226		240
227	This sets the callback that is called when the write buffer becomes empty	241	This sets the callback that is called once when the write buffer becomes
228	(or immediately if the buffer is empty already).	242	empty (and immediately when the handle object is created).
229		243
230	To append to the write buffer, use the C<< ->push_write >> method.	244	To append to the write buffer, use the C<< ->push_write >> method.
231		245
232	This callback is useful when you don't want to put all of your write data	246	This callback is useful when you don't want to put all of your write data
233	into the queue at once, for example, when you want to write the contents	247	into the queue at once, for example, when you want to write the contents
…		…
245	many seconds pass without a successful read or write on the underlying	259	many seconds pass without a successful read or write on the underlying
246	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback	260	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
247	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>	261	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
248	error will be raised).	262	error will be raised).
249		263
250	There are three variants of the timeouts that work independently	264	There are three variants of the timeouts that work independently of each
251	of each other, for both read and write, just read, and just write:	265	other, for both read and write (triggered when nothing was read I<OR>
		266	written), just read (triggered when nothing was read), and just write:
252	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks	267	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
253	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions	268	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
254	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.	269	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
255		270
256	Note that timeout processing is active even when you do not have	271	Note that timeout processing is active even when you do not have any
257	any outstanding read or write requests: If you plan to keep the connection	272	outstanding read or write requests: If you plan to keep the connection
258	idle then you should disable the timeout temporarily or ignore the timeout	273	idle then you should disable the timeout temporarily or ignore the
259	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply	274	timeout in the corresponding C<on_timeout> callback, in which case
260	restart the timeout.	275	AnyEvent::Handle will simply restart the timeout.
261		276
262	Zero (the default) disables this timeout.	277	Zero (the default) disables the corresponding timeout.
263		278
264	=item on_timeout => $cb->($handle)	279	=item on_timeout => $cb->($handle)
		280
		281	=item on_rtimeout => $cb->($handle)
		282
		283	=item on_wtimeout => $cb->($handle)
265		284
266	Called whenever the inactivity timeout passes. If you return from this	285	Called whenever the inactivity timeout passes. If you return from this
267	callback, then the timeout will be reset as if some activity had happened,	286	callback, then the timeout will be reset as if some activity had happened,
268	so this condition is not fatal in any way.	287	so this condition is not fatal in any way.
269		288
…		…
276	For example, a server accepting connections from untrusted sources should	295	For example, a server accepting connections from untrusted sources should
277	be configured to accept only so-and-so much data that it cannot act on	296	be configured to accept only so-and-so much data that it cannot act on
278	(for example, when expecting a line, an attacker could send an unlimited	297	(for example, when expecting a line, an attacker could send an unlimited
279	amount of data without a callback ever being called as long as the line	298	amount of data without a callback ever being called as long as the line
280	isn't finished).	299	isn't finished).
		300
		301	=item wbuf_max => <bytes>
		302
		303	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		304	when the write buffer ever (strictly) exceeds this size. This is useful to
		305	avoid some forms of denial-of-service attacks.
		306
		307	Although the units of this parameter is bytes, this is the I<raw> number
		308	of bytes not yet accepted by the kernel. This can make a difference when
		309	you e.g. use TLS, as TLS typically makes your write data larger (but it
		310	can also make it smaller due to compression).
		311
		312	As an example of when this limit is useful, take a chat server that sends
		313	chat messages to a client. If the client does not read those in a timely
		314	manner then the send buffer in the server would grow unbounded.
281		315
282	=item autocork => <boolean>	316	=item autocork => <boolean>
283		317
284	When disabled (the default), C<push_write> will try to immediately	318	When disabled (the default), C<push_write> will try to immediately
285	write the data to the handle if possible. This avoids having to register	319	write the data to the handle if possible. This avoids having to register
…		…
337	already have occured on BSD systems), but at least it will protect you	371	already have occured on BSD systems), but at least it will protect you
338	from most attacks.	372	from most attacks.
339		373
340	=item read_size => <bytes>	374	=item read_size => <bytes>
341		375
342	The default read block size (the number of bytes this module will	376	The initial read block size, the number of bytes this module will try
343	try to read during each loop iteration, which affects memory	377	to read during each loop iteration. Each handle object will consume
344	requirements). Default: C<8192>.	378	at least this amount of memory for the read buffer as well, so when
		379	handling many connections watch out for memory requirements). See also
		380	C<max_read_size>. Default: C<2048>.
		381
		382	=item max_read_size => <bytes>
		383
		384	The maximum read buffer size used by the dynamic adjustment
		385	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		386	one go it will double C<read_size> up to the maximum given by this
		387	option. Default: C<131072> or C<read_size>, whichever is higher.
345		388
346	=item low_water_mark => <bytes>	389	=item low_water_mark => <bytes>
347		390
348	Sets the number of bytes (default: C<0>) that make up an "empty" write	391	Sets the number of bytes (default: C<0>) that make up an "empty" write
349	buffer: If the buffer reaches this size or gets even samller it is	392	buffer: If the buffer reaches this size or gets even samller it is
…		…
386	appropriate error message.	429	appropriate error message.
387		430
388	TLS mode requires Net::SSLeay to be installed (it will be loaded	431	TLS mode requires Net::SSLeay to be installed (it will be loaded
389	automatically when you try to create a TLS handle): this module doesn't	432	automatically when you try to create a TLS handle): this module doesn't
390	have a dependency on that module, so if your module requires it, you have	433	have a dependency on that module, so if your module requires it, you have
391	to add the dependency yourself.	434	to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
		435	old, you get an C<EPROTO> error.
392		436
393	Unlike TCP, TLS has a server and client side: for the TLS server side, use	437	Unlike TCP, TLS has a server and client side: for the TLS server side, use
394	C<accept>, and for the TLS client side of a connection, use C<connect>	438	C<accept>, and for the TLS client side of a connection, use C<connect>
395	mode.	439	mode.
396		440
…		…
412	Use the C<< ->starttls >> method if you need to start TLS negotiation later.	456	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
413		457
414	=item tls_ctx => $anyevent_tls	458	=item tls_ctx => $anyevent_tls
415		459
416	Use the given C<AnyEvent::TLS> object to create the new TLS connection	460	Use the given C<AnyEvent::TLS> object to create the new TLS connection
417	(unless a connection object was specified directly). If this parameter is	461	(unless a connection object was specified directly). If this
418	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	462	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		463	C<AnyEvent::Handle::TLS_CTX>.
419		464
420	Instead of an object, you can also specify a hash reference with C<< key	465	Instead of an object, you can also specify a hash reference with C<< key
421	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a	466	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
422	new TLS context object.	467	new TLS context object.
423		468
…		…
492	$self->{connect}[0],	537	$self->{connect}[0],
493	$self->{connect}[1],	538	$self->{connect}[1],
494	sub {	539	sub {
495	my ($fh, $host, $port, $retry) = @_;	540	my ($fh, $host, $port, $retry) = @_;
496		541
		542	delete $self->{_connect}; # no longer needed
		543
497	if ($fh) {	544	if ($fh) {
498	$self->{fh} = $fh;	545	$self->{fh} = $fh;
499		546
500	delete $self->{_skip_drain_rbuf};	547	delete $self->{_skip_drain_rbuf};
501	$self->_start;	548	$self->_start;
…		…
508	});	555	});
509		556
510	} else {	557	} else {
511	if ($self->{on_connect_error}) {	558	if ($self->{on_connect_error}) {
512	$self->{on_connect_error}($self, "$!");	559	$self->{on_connect_error}($self, "$!");
513	$self->destroy;	560	$self->destroy if $self;
514	} else {	561	} else {
515	$self->_error ($!, 1);	562	$self->_error ($!, 1);
516	}	563	}
517	}	564	}
518	},	565	},
519	sub {	566	sub {
520	local $self->{fh} = $_[0];	567	local $self->{fh} = $_[0];
521		568
522	$self->{on_prepare}	569	$self->{on_prepare}
523	? $self->{on_prepare}->($self)	570	? $self->{on_prepare}->($self)
524	: ()	571	: ()
525	}	572	}
526	);	573	);
527	}	574	}
528		575
…		…
546		593
547	$self->{_activity} =	594	$self->{_activity} =
548	$self->{_ractivity} =	595	$self->{_ractivity} =
549	$self->{_wactivity} = AE::now;	596	$self->{_wactivity} = AE::now;
550		597
		598	$self->{read_size} \|\|= 2048;
		599	$self->{max_read_size} = $self->{read_size}
		600	if $self->{read_size} > ($self->{max_read_size} \|\| MAX_READ_SIZE);
		601
551	$self->timeout (delete $self->{timeout} ) if $self->{timeout};	602	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
552	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};	603	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
553	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};	604	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
554		605
555	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};	606	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
…		…
558	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);	609	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
559		610
560	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})	611	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
561	if $self->{tls};	612	if $self->{tls};
562		613
563	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	614	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
564		615
565	$self->start_read	616	$self->start_read
566	if $self->{on_read} \|\| @{ $self->{_queue} };	617	if $self->{on_read} \|\| @{ $self->{_queue} };
567		618
568	$self->_drain_wbuf;	619	$self->_drain_wbuf;
…		…
644	=cut	695	=cut
645		696
646	sub no_delay {	697	sub no_delay {
647	$_[0]{no_delay} = $_[1];	698	$_[0]{no_delay} = $_[1];
648		699
649	eval {
650	local $SIG{__DIE__};
651	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]	700	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
652	if $_[0]{fh};	701	if $_[0]{fh};
653	};
654	}	702	}
655		703
656	=item $handle->keepalive ($boolean)	704	=item $handle->keepalive ($boolean)
657		705
658	Enables or disables the C<keepalive> setting (see constructor argument of	706	Enables or disables the C<keepalive> setting (see constructor argument of
…		…
726		774
727	=item $handle->rbuf_max ($max_octets)	775	=item $handle->rbuf_max ($max_octets)
728		776
729	Configures the C<rbuf_max> setting (C<undef> disables it).	777	Configures the C<rbuf_max> setting (C<undef> disables it).
730		778
		779	=item $handle->wbuf_max ($max_octets)
		780
		781	Configures the C<wbuf_max> setting (C<undef> disables it).
		782
731	=cut	783	=cut
732		784
733	sub rbuf_max {	785	sub rbuf_max {
734	$_[0]{rbuf_max} = $_[1];	786	$_[0]{rbuf_max} = $_[1];
735	}	787	}
736		788
		789	sub wbuf_max {
		790	$_[0]{wbuf_max} = $_[1];
		791	}
		792
737	#############################################################################	793	#############################################################################
738		794
739	=item $handle->timeout ($seconds)	795	=item $handle->timeout ($seconds)
740		796
741	=item $handle->rtimeout ($seconds)	797	=item $handle->rtimeout ($seconds)
742		798
743	=item $handle->wtimeout ($seconds)	799	=item $handle->wtimeout ($seconds)
744		800
745	Configures (or disables) the inactivity timeout.	801	Configures (or disables) the inactivity timeout.
		802
		803	The timeout will be checked instantly, so this method might destroy the
		804	handle before it returns.
746		805
747	=item $handle->timeout_reset	806	=item $handle->timeout_reset
748		807
749	=item $handle->rtimeout_reset	808	=item $handle->rtimeout_reset
750		809
…		…
767	$_[0]{$on_timeout} = $_[1];	826	$_[0]{$on_timeout} = $_[1];
768	};	827	};
769		828
770	*$timeout = sub {	829	*$timeout = sub {
771	my ($self, $new_value) = @_;	830	my ($self, $new_value) = @_;
		831
		832	$new_value >= 0
		833	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
772		834
773	$self->{$timeout} = $new_value;	835	$self->{$timeout} = $new_value;
774	delete $self->{$tw}; &$cb;	836	delete $self->{$tw}; &$cb;
775	};	837	};
776		838
…		…
831		893
832	The write queue is very simple: you can add data to its end, and	894	The write queue is very simple: you can add data to its end, and
833	AnyEvent::Handle will automatically try to get rid of it for you.	895	AnyEvent::Handle will automatically try to get rid of it for you.
834		896
835	When data could be written and the write buffer is shorter then the low	897	When data could be written and the write buffer is shorter then the low
836	water mark, the C<on_drain> callback will be invoked.	898	water mark, the C<on_drain> callback will be invoked once.
837		899
838	=over 4	900	=over 4
839		901
840	=item $handle->on_drain ($cb)	902	=item $handle->on_drain ($cb)
841		903
…		…
856	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});	918	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
857	}	919	}
858		920
859	=item $handle->push_write ($data)	921	=item $handle->push_write ($data)
860		922
861	Queues the given scalar to be written. You can push as much data as you	923	Queues the given scalar to be written. You can push as much data as
862	want (only limited by the available memory), as C<AnyEvent::Handle>	924	you want (only limited by the available memory and C<wbuf_max>), as
863	buffers it independently of the kernel.	925	C<AnyEvent::Handle> buffers it independently of the kernel.
864		926
865	This method may invoke callbacks (and therefore the handle might be	927	This method may invoke callbacks (and therefore the handle might be
866	destroyed after it returns).	928	destroyed after it returns).
867		929
868	=cut	930	=cut
…		…
896	$cb->() unless $self->{autocork};	958	$cb->() unless $self->{autocork};
897		959
898	# if still data left in wbuf, we need to poll	960	# if still data left in wbuf, we need to poll
899	$self->{_ww} = AE::io $self->{fh}, 1, $cb	961	$self->{_ww} = AE::io $self->{fh}, 1, $cb
900	if length $self->{wbuf};	962	if length $self->{wbuf};
		963
		964	if (
		965	defined $self->{wbuf_max}
		966	&& $self->{wbuf_max} < length $self->{wbuf}
		967	) {
		968	$self->_error (Errno::ENOSPC, 1), return;
		969	}
901	};	970	};
902	}	971	}
903		972
904	our %WH;	973	our %WH;
905		974
…		…
1025	=cut	1094	=cut
1026		1095
1027	register_write_type storable => sub {	1096	register_write_type storable => sub {
1028	my ($self, $ref) = @_;	1097	my ($self, $ref) = @_;
1029		1098
1030	require Storable;	1099	require Storable unless $Storable::VERSION;
1031		1100
1032	pack "w/a*", Storable::nfreeze ($ref)	1101	pack "w/a*", Storable::nfreeze ($ref)
1033	};	1102	};
1034		1103
1035	=back	1104	=back
…		…
1040	before it was actually written. One way to do that is to replace your	1109	before it was actually written. One way to do that is to replace your
1041	C<on_drain> handler by a callback that shuts down the socket (and set	1110	C<on_drain> handler by a callback that shuts down the socket (and set
1042	C<low_water_mark> to C<0>). This method is a shorthand for just that, and	1111	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1043	replaces the C<on_drain> callback with:	1112	replaces the C<on_drain> callback with:
1044		1113
1045	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown	1114	sub { shutdown $_[0]{fh}, 1 }
1046		1115
1047	This simply shuts down the write side and signals an EOF condition to the	1116	This simply shuts down the write side and signals an EOF condition to the
1048	the peer.	1117	the peer.
1049		1118
1050	You can rely on the normal read queue and C<on_eof> handling	1119	You can rely on the normal read queue and C<on_eof> handling
…		…
1072		1141
1073	Whenever the given C<type> is used, C<push_write> will the function with	1142	Whenever the given C<type> is used, C<push_write> will the function with
1074	the handle object and the remaining arguments.	1143	the handle object and the remaining arguments.
1075		1144
1076	The function is supposed to return a single octet string that will be	1145	The function is supposed to return a single octet string that will be
1077	appended to the write buffer, so you cna mentally treat this function as a	1146	appended to the write buffer, so you can mentally treat this function as a
1078	"arguments to on-the-wire-format" converter.	1147	"arguments to on-the-wire-format" converter.
1079		1148
1080	Example: implement a custom write type C<join> that joins the remaining	1149	Example: implement a custom write type C<join> that joins the remaining
1081	arguments using the first one.	1150	arguments using the first one.
1082		1151
…		…
1271	$self->_drain_rbuf if $cb;	1340	$self->_drain_rbuf if $cb;
1272	}	1341	}
1273		1342
1274	=item $handle->rbuf	1343	=item $handle->rbuf
1275		1344
1276	Returns the read buffer (as a modifiable lvalue).	1345	Returns the read buffer (as a modifiable lvalue). You can also access the
		1346	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1347	much faster, and no less clean).
1277		1348
1278	You can access the read buffer directly as the C<< ->{rbuf} >>	1349	The only operation allowed on the read buffer (apart from looking at it)
1279	member, if you want. However, the only operation allowed on the	1350	is removing data from its beginning. Otherwise modifying or appending to
1280	read buffer (apart from looking at it) is removing data from its	1351	it is not allowed and will lead to hard-to-track-down bugs.
1281	beginning. Otherwise modifying or appending to it is not allowed and will
1282	lead to hard-to-track-down bugs.
1283		1352
1284	NOTE: The read buffer should only be used or modified if the C<on_read>,	1353	NOTE: The read buffer should only be used or modified in the C<on_read>
1285	C<push_read> or C<unshift_read> methods are used. The other read methods	1354	callback or when C<push_read> or C<unshift_read> are used with a single
1286	automatically manage the read buffer.	1355	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1356	will manage the read buffer on their own.
1287		1357
1288	=cut	1358	=cut
1289		1359
1290	sub rbuf : lvalue {	1360	sub rbuf : lvalue {
1291	$_[0]{rbuf}	1361	$_[0]{rbuf}
…		…
1342	my $cb = pop;	1412	my $cb = pop;
1343		1413
1344	if (@_) {	1414	if (@_) {
1345	my $type = shift;	1415	my $type = shift;
1346		1416
		1417	$cb = ($RH{$type} \|\|= _load_func "$type\::anyevent_read_type"
1347	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1418	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
1348	->($self, $cb, @_);	1419	->($self, $cb, @_);
1349	}	1420	}
1350		1421
1351	unshift @{ $self->{_queue} }, $cb;	1422	unshift @{ $self->{_queue} }, $cb;
1352	$self->_drain_rbuf;	1423	$self->_drain_rbuf;
…		…
1374	data.	1445	data.
1375		1446
1376	Example: read 2 bytes.	1447	Example: read 2 bytes.
1377		1448
1378	$handle->push_read (chunk => 2, sub {	1449	$handle->push_read (chunk => 2, sub {
1379	warn "yay ", unpack "H*", $_[1];	1450	say "yay " . unpack "H*", $_[1];
1380	});	1451	});
1381		1452
1382	=cut	1453	=cut
1383		1454
1384	register_read_type chunk => sub {	1455	register_read_type chunk => sub {
…		…
1418	if (@_ < 3) {	1489	if (@_ < 3) {
1419	# this is more than twice as fast as the generic code below	1490	# this is more than twice as fast as the generic code below
1420	sub {	1491	sub {
1421	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;	1492	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1422		1493
1423	$cb->($_[0], $1, $2);	1494	$cb->($_[0], "$1", "$2");
1424	1	1495	1
1425	}	1496	}
1426	} else {	1497	} else {
1427	$eol = quotemeta $eol unless ref $eol;	1498	$eol = quotemeta $eol unless ref $eol;
1428	$eol = qr\|^(.*?)($eol)\|s;	1499	$eol = qr\|^(.*?)($eol)\|s;
1429		1500
1430	sub {	1501	sub {
1431	$_[0]{rbuf} =~ s/$eol// or return;	1502	$_[0]{rbuf} =~ s/$eol// or return;
1432		1503
1433	$cb->($_[0], $1, $2);	1504	$cb->($_[0], "$1", "$2");
1434	1	1505	1
1435	}	1506	}
1436	}	1507	}
1437	};	1508	};
1438		1509
…		…
1486		1557
1487	sub {	1558	sub {
1488	# accept	1559	# accept
1489	if ($$rbuf =~ $accept) {	1560	if ($$rbuf =~ $accept) {
1490	$data .= substr $$rbuf, 0, $+[0], "";	1561	$data .= substr $$rbuf, 0, $+[0], "";
1491	$cb->($self, $data);	1562	$cb->($_[0], $data);
1492	return 1;	1563	return 1;
1493	}	1564	}
1494		1565
1495	# reject	1566	# reject
1496	if ($reject && $$rbuf =~ $reject) {	1567	if ($reject && $$rbuf =~ $reject) {
1497	$self->_error (Errno::EBADMSG);	1568	$_[0]->_error (Errno::EBADMSG);
1498	}	1569	}
1499		1570
1500	# skip	1571	# skip
1501	if ($skip && $$rbuf =~ $skip) {	1572	if ($skip && $$rbuf =~ $skip) {
1502	$data .= substr $$rbuf, 0, $+[0], "";	1573	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1518	my ($self, $cb) = @_;	1589	my ($self, $cb) = @_;
1519		1590
1520	sub {	1591	sub {
1521	unless ($_[0]{rbuf} =~ s/^(0\|[1-9][0-9]*)://) {	1592	unless ($_[0]{rbuf} =~ s/^(0\|[1-9][0-9]*)://) {
1522	if ($_[0]{rbuf} =~ /[^0-9]/) {	1593	if ($_[0]{rbuf} =~ /[^0-9]/) {
1523	$self->_error (Errno::EBADMSG);	1594	$_[0]->_error (Errno::EBADMSG);
1524	}	1595	}
1525	return;	1596	return;
1526	}	1597	}
1527		1598
1528	my $len = $1;	1599	my $len = $1;
1529		1600
1530	$self->unshift_read (chunk => $len, sub {	1601	$_[0]->unshift_read (chunk => $len, sub {
1531	my $string = $_[1];	1602	my $string = $_[1];
1532	$_[0]->unshift_read (chunk => 1, sub {	1603	$_[0]->unshift_read (chunk => 1, sub {
1533	if ($_[1] eq ",") {	1604	if ($_[1] eq ",") {
1534	$cb->($_[0], $string);	1605	$cb->($_[0], $string);
1535	} else {	1606	} else {
1536	$self->_error (Errno::EBADMSG);	1607	$_[0]->_error (Errno::EBADMSG);
1537	}	1608	}
1538	});	1609	});
1539	});	1610	});
1540		1611
1541	1	1612	1
…		…
1614		1685
1615	my $data;	1686	my $data;
1616	my $rbuf = \$self->{rbuf};	1687	my $rbuf = \$self->{rbuf};
1617		1688
1618	sub {	1689	sub {
1619	my $ref = eval { $json->incr_parse ($self->{rbuf}) };	1690	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1620		1691
1621	if ($ref) {	1692	if ($ref) {
1622	$self->{rbuf} = $json->incr_text;	1693	$_[0]{rbuf} = $json->incr_text;
1623	$json->incr_text = "";	1694	$json->incr_text = "";
1624	$cb->($self, $ref);	1695	$cb->($_[0], $ref);
1625		1696
1626	1	1697	1
1627	} elsif ($@) {	1698	} elsif ($@) {
1628	# error case	1699	# error case
1629	$json->incr_skip;	1700	$json->incr_skip;
1630		1701
1631	$self->{rbuf} = $json->incr_text;	1702	$_[0]{rbuf} = $json->incr_text;
1632	$json->incr_text = "";	1703	$json->incr_text = "";
1633		1704
1634	$self->_error (Errno::EBADMSG);	1705	$_[0]->_error (Errno::EBADMSG);
1635		1706
1636	()	1707	()
1637	} else {	1708	} else {
1638	$self->{rbuf} = "";	1709	$_[0]{rbuf} = "";
1639		1710
1640	()	1711	()
1641	}	1712	}
1642	}	1713	}
1643	};	1714	};
…		…
1653	=cut	1724	=cut
1654		1725
1655	register_read_type storable => sub {	1726	register_read_type storable => sub {
1656	my ($self, $cb) = @_;	1727	my ($self, $cb) = @_;
1657		1728
1658	require Storable;	1729	require Storable unless $Storable::VERSION;
1659		1730
1660	sub {	1731	sub {
1661	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method	1732	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1662	defined (my $len = eval { unpack "w", $_[0]{rbuf} })	1733	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1663	or return;	1734	or return;
…		…
1666		1737
1667	# bypass unshift if we already have the remaining chunk	1738	# bypass unshift if we already have the remaining chunk
1668	if ($format + $len <= length $_[0]{rbuf}) {	1739	if ($format + $len <= length $_[0]{rbuf}) {
1669	my $data = substr $_[0]{rbuf}, $format, $len;	1740	my $data = substr $_[0]{rbuf}, $format, $len;
1670	substr $_[0]{rbuf}, 0, $format + $len, "";	1741	substr $_[0]{rbuf}, 0, $format + $len, "";
		1742
1671	$cb->($_[0], Storable::thaw ($data));	1743	eval { $cb->($_[0], Storable::thaw ($data)); 1 }
		1744	or return $_[0]->_error (Errno::EBADMSG);
1672	} else {	1745	} else {
1673	# remove prefix	1746	# remove prefix
1674	substr $_[0]{rbuf}, 0, $format, "";	1747	substr $_[0]{rbuf}, 0, $format, "";
1675		1748
1676	# read remaining chunk	1749	# read remaining chunk
1677	$_[0]->unshift_read (chunk => $len, sub {	1750	$_[0]->unshift_read (chunk => $len, sub {
1678	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1751	eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1679	$cb->($_[0], $ref);
1680	} else {
1681	$self->_error (Errno::EBADMSG);	1752	or $_[0]->_error (Errno::EBADMSG);
1682	}
1683	});	1753	});
1684	}	1754	}
1685		1755
1686	1	1756	1
1687	}	1757	}
…		…
1724	Note that AnyEvent::Handle will automatically C<start_read> for you when	1794	Note that AnyEvent::Handle will automatically C<start_read> for you when
1725	you change the C<on_read> callback or push/unshift a read callback, and it	1795	you change the C<on_read> callback or push/unshift a read callback, and it
1726	will automatically C<stop_read> for you when neither C<on_read> is set nor	1796	will automatically C<stop_read> for you when neither C<on_read> is set nor
1727	there are any read requests in the queue.	1797	there are any read requests in the queue.
1728		1798
1729	These methods will have no effect when in TLS mode (as TLS doesn't support	1799	In older versions of this module (<= 5.3), these methods had no effect,
1730	half-duplex connections).	1800	as TLS does not support half-duplex connections. In current versions they
		1801	work as expected, as this behaviour is required to avoid certain resource
		1802	attacks, where the program would be forced to read (and buffer) arbitrary
		1803	amounts of data before being able to send some data. The drawback is that
		1804	some readings of the the SSL/TLS specifications basically require this
		1805	attack to be working, as SSL/TLS implementations might stall sending data
		1806	during a rehandshake.
		1807
		1808	As a guideline, during the initial handshake, you should not stop reading,
		1809	and as a client, it might cause problems, depending on your application.
1731		1810
1732	=cut	1811	=cut
1733		1812
1734	sub stop_read {	1813	sub stop_read {
1735	my ($self) = @_;	1814	my ($self) = @_;
1736		1815
1737	delete $self->{_rw} unless $self->{tls};	1816	delete $self->{_rw};
1738	}	1817	}
1739		1818
1740	sub start_read {	1819	sub start_read {
1741	my ($self) = @_;	1820	my ($self) = @_;
1742		1821
1743	unless ($self->{_rw} \|\| $self->{_eof} \|\| !$self->{fh}) {	1822	unless ($self->{_rw} \|\| $self->{_eof} \|\| !$self->{fh}) {
1744	Scalar::Util::weaken $self;	1823	Scalar::Util::weaken $self;
1745		1824
1746	$self->{_rw} = AE::io $self->{fh}, 0, sub {	1825	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1747	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});	1826	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1748	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} \|\| 8192, length $$rbuf;	1827	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1749		1828
1750	if ($len > 0) {	1829	if ($len > 0) {
1751	$self->{_activity} = $self->{_ractivity} = AE::now;	1830	$self->{_activity} = $self->{_ractivity} = AE::now;
1752		1831
1753	if ($self->{tls}) {	1832	if ($self->{tls}) {
…		…
1756	&_dotls ($self);	1835	&_dotls ($self);
1757	} else {	1836	} else {
1758	$self->_drain_rbuf;	1837	$self->_drain_rbuf;
1759	}	1838	}
1760		1839
		1840	if ($len == $self->{read_size}) {
		1841	$self->{read_size} *= 2;
		1842	$self->{read_size} = $self->{max_read_size} \|\| MAX_READ_SIZE
		1843	if $self->{read_size} > ($self->{max_read_size} \|\| MAX_READ_SIZE);
		1844	}
		1845
1761	} elsif (defined $len) {	1846	} elsif (defined $len) {
1762	delete $self->{_rw};	1847	delete $self->{_rw};
1763	$self->{_eof} = 1;	1848	$self->{_eof} = 1;
1764	$self->_drain_rbuf;	1849	$self->_drain_rbuf;
1765		1850
…		…
1777	my ($self, $err) = @_;	1862	my ($self, $err) = @_;
1778		1863
1779	return $self->_error ($!, 1)	1864	return $self->_error ($!, 1)
1780	if $err == Net::SSLeay::ERROR_SYSCALL ();	1865	if $err == Net::SSLeay::ERROR_SYSCALL ();
1781		1866
1782	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());	1867	my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1783		1868
1784	# reduce error string to look less scary	1869	# reduce error string to look less scary
1785	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;	1870	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1786		1871
1787	if ($self->{_on_starttls}) {	1872	if ($self->{_on_starttls}) {
…		…
1853		1938
1854	=item $handle->starttls ($tls[, $tls_ctx])	1939	=item $handle->starttls ($tls[, $tls_ctx])
1855		1940
1856	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1941	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1857	object is created, you can also do that at a later time by calling	1942	object is created, you can also do that at a later time by calling
1858	C<starttls>.	1943	C<starttls>. See the C<tls> constructor argument for general info.
1859		1944
1860	Starting TLS is currently an asynchronous operation - when you push some	1945	Starting TLS is currently an asynchronous operation - when you push some
1861	write data and then call C<< ->starttls >> then TLS negotiation will start	1946	write data and then call C<< ->starttls >> then TLS negotiation will start
1862	immediately, after which the queued write data is then sent.	1947	immediately, after which the queued write data is then sent. This might
		1948	change in future versions, so best make sure you have no outstanding write
		1949	data when calling this method.
1863		1950
1864	The first argument is the same as the C<tls> constructor argument (either	1951	The first argument is the same as the C<tls> constructor argument (either
1865	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1952	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1866		1953
1867	The second argument is the optional C<AnyEvent::TLS> object that is used	1954	The second argument is the optional C<AnyEvent::TLS> object that is used
…		…
1889	my ($self, $tls, $ctx) = @_;	1976	my ($self, $tls, $ctx) = @_;
1890		1977
1891	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"	1978	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1892	if $self->{tls};	1979	if $self->{tls};
1893		1980
		1981	unless (defined $AnyEvent::TLS::VERSION) {
		1982	eval {
		1983	require Net::SSLeay;
		1984	require AnyEvent::TLS;
		1985	1
		1986	} or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
		1987	}
		1988
1894	$self->{tls} = $tls;	1989	$self->{tls} = $tls;
1895	$self->{tls_ctx} = $ctx if @_ > 2;	1990	$self->{tls_ctx} = $ctx if @_ > 2;
1896		1991
1897	return unless $self->{fh};	1992	return unless $self->{fh};
1898		1993
1899	require Net::SSLeay;
1900
1901	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();	1994	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1902	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();	1995	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1903		1996
1904	$tls = delete $self->{tls};	1997	$tls = delete $self->{tls};
1905	$ctx = $self->{tls_ctx};	1998	$ctx = $self->{tls_ctx};
1906		1999
1907	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session	2000	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1908		2001
1909	if ("HASH" eq ref $ctx) {	2002	if ("HASH" eq ref $ctx) {
1910	require AnyEvent::TLS;
1911
1912	if ($ctx->{cache}) {	2003	if ($ctx->{cache}) {
1913	my $key = $ctx+0;	2004	my $key = $ctx+0;
1914	$ctx = $TLS_CACHE{$key} \|\|= new AnyEvent::TLS %$ctx;	2005	$ctx = $TLS_CACHE{$key} \|\|= new AnyEvent::TLS %$ctx;
1915	} else {	2006	} else {
1916	$ctx = new AnyEvent::TLS %$ctx;	2007	$ctx = new AnyEvent::TLS %$ctx;
…		…
1938	Net::SSLeay::CTX_set_mode ($tls, 1\|2);	2029	Net::SSLeay::CTX_set_mode ($tls, 1\|2);
1939		2030
1940	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2031	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1941	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2032	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1942		2033
1943	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});	2034	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2035	$self->{rbuf} = "";
1944		2036
1945	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});	2037	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1946		2038
1947	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }	2039	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1948	if $self->{on_starttls};	2040	if $self->{on_starttls};
…		…
1986	if $self->{tls} > 0;	2078	if $self->{tls} > 0;
1987		2079
1988	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};	2080	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1989	}	2081	}
1990		2082
		2083	=item $handle->resettls
		2084
		2085	This rarely-used method simply resets and TLS state on the handle, usually
		2086	causing data loss.
		2087
		2088	One case where it may be useful is when you want to skip over the data in
		2089	the stream but you are not interested in interpreting it, so data loss is
		2090	no concern.
		2091
		2092	=cut
		2093
		2094	*resettls = \&_freetls;
		2095
1991	sub DESTROY {	2096	sub DESTROY {
1992	my ($self) = @_;	2097	my ($self) = @_;
1993		2098
1994	&_freetls;	2099	&_freetls;
1995		2100
…		…
2004	push @linger, AE::io $fh, 1, sub {	2109	push @linger, AE::io $fh, 1, sub {
2005	my $len = syswrite $fh, $wbuf, length $wbuf;	2110	my $len = syswrite $fh, $wbuf, length $wbuf;
2006		2111
2007	if ($len > 0) {	2112	if ($len > 0) {
2008	substr $wbuf, 0, $len, "";	2113	substr $wbuf, 0, $len, "";
2009	} else {	2114	} elsif (defined $len \|\| ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
2010	@linger = (); # end	2115	@linger = (); # end
2011	}	2116	}
2012	};	2117	};
2013	push @linger, AE::timer $linger, 0, sub {	2118	push @linger, AE::timer $linger, 0, sub {
2014	@linger = ();	2119	@linger = ();
…		…
2110		2215
2111	It is only safe to "forget" the reference inside EOF or error callbacks,	2216	It is only safe to "forget" the reference inside EOF or error callbacks,
2112	from within all other callbacks, you need to explicitly call the C<<	2217	from within all other callbacks, you need to explicitly call the C<<
2113	->destroy >> method.	2218	->destroy >> method.
2114		2219
		2220	=item Why is my C<on_eof> callback never called?
		2221
		2222	Probably because your C<on_error> callback is being called instead: When
		2223	you have outstanding requests in your read queue, then an EOF is
		2224	considered an error as you clearly expected some data.
		2225
		2226	To avoid this, make sure you have an empty read queue whenever your handle
		2227	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2228	an C<on_read> handler that simply pushes the first read requests in the
		2229	queue.
		2230
		2231	See also the next question, which explains this in a bit more detail.
		2232
		2233	=item How can I serve requests in a loop?
		2234
		2235	Most protocols consist of some setup phase (authentication for example)
		2236	followed by a request handling phase, where the server waits for requests
		2237	and handles them, in a loop.
		2238
		2239	There are two important variants: The first (traditional, better) variant
		2240	handles requests until the server gets some QUIT command, causing it to
		2241	close the connection first (highly desirable for a busy TCP server). A
		2242	client dropping the connection is an error, which means this variant can
		2243	detect an unexpected detection close.
		2244
		2245	To handle this case, always make sure you have a on-empty read queue, by
		2246	pushing the "read request start" handler on it:
		2247
		2248	# we assume a request starts with a single line
		2249	my @start_request; @start_request = (line => sub {
		2250	my ($hdl, $line) = @_;
		2251
		2252	... handle request
		2253
		2254	# push next request read, possibly from a nested callback
		2255	$hdl->push_read (@start_request);
		2256	});
		2257
		2258	# auth done, now go into request handling loop
		2259	# now push the first @start_request
		2260	$hdl->push_read (@start_request);
		2261
		2262	By always having an outstanding C<push_read>, the handle always expects
		2263	some data and raises the C<EPIPE> error when the connction is dropped
		2264	unexpectedly.
		2265
		2266	The second variant is a protocol where the client can drop the connection
		2267	at any time. For TCP, this means that the server machine may run out of
		2268	sockets easier, and in general, it means you cannot distinguish a protocl
		2269	failure/client crash from a normal connection close. Nevertheless, these
		2270	kinds of protocols are common (and sometimes even the best solution to the
		2271	problem).
		2272
		2273	Having an outstanding read request at all times is possible if you ignore
		2274	C<EPIPE> errors, but this doesn't help with when the client drops the
		2275	connection during a request, which would still be an error.
		2276
		2277	A better solution is to push the initial request read in an C<on_read>
		2278	callback. This avoids an error, as when the server doesn't expect data
		2279	(i.e. is idly waiting for the next request, an EOF will not raise an
		2280	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2281	and simpler:
		2282
		2283	# auth done, now go into request handling loop
		2284	$hdl->on_read (sub {
		2285	my ($hdl) = @_;
		2286
		2287	# called each time we receive data but the read queue is empty
		2288	# simply start read the request
		2289
		2290	$hdl->push_read (line => sub {
		2291	my ($hdl, $line) = @_;
		2292
		2293	... handle request
		2294
		2295	# do nothing special when the request has been handled, just
		2296	# let the request queue go empty.
		2297	});
		2298	});
		2299
2115	=item I get different callback invocations in TLS mode/Why can't I pause	2300	=item I get different callback invocations in TLS mode/Why can't I pause
2116	reading?	2301	reading?
2117		2302
2118	Unlike, say, TCP, TLS connections do not consist of two independent	2303	Unlike, say, TCP, TLS connections do not consist of two independent
2119	communication channels, one for each direction. Or put differently, the	2304	communication channels, one for each direction. Or put differently, the
…		…
2140	$handle->on_eof (undef);	2325	$handle->on_eof (undef);
2141	$handle->on_error (sub {	2326	$handle->on_error (sub {
2142	my $data = delete $_[0]{rbuf};	2327	my $data = delete $_[0]{rbuf};
2143	});	2328	});
2144		2329
		2330	Note that this example removes the C<rbuf> member from the handle object,
		2331	which is not normally allowed by the API. It is expressly permitted in
		2332	this case only, as the handle object needs to be destroyed afterwards.
		2333
2145	The reason to use C<on_error> is that TCP connections, due to latencies	2334	The reason to use C<on_error> is that TCP connections, due to latencies
2146	and packets loss, might get closed quite violently with an error, when in	2335	and packets loss, might get closed quite violently with an error, when in
2147	fact all data has been received.	2336	fact all data has been received.
2148		2337
2149	It is usually better to use acknowledgements when transferring data,	2338	It is usually better to use acknowledgements when transferring data,
…		…
2159	C<low_water_mark> this will be called precisely when all data has been	2348	C<low_water_mark> this will be called precisely when all data has been
2160	written to the socket:	2349	written to the socket:
2161		2350
2162	$handle->push_write (...);	2351	$handle->push_write (...);
2163	$handle->on_drain (sub {	2352	$handle->on_drain (sub {
2164	warn "all data submitted to the kernel\n";	2353	AE::log debug => "All data submitted to the kernel.";
2165	undef $handle;	2354	undef $handle;
2166	});	2355	});
2167		2356
2168	If you just want to queue some data and then signal EOF to the other side,	2357	If you just want to queue some data and then signal EOF to the other side,
2169	consider using C<< ->push_shutdown >> instead.	2358	consider using C<< ->push_shutdown >> instead.
…		…
2253	When you have intermediate CA certificates that your clients might not	2442	When you have intermediate CA certificates that your clients might not
2254	know about, just append them to the C<cert_file>.	2443	know about, just append them to the C<cert_file>.
2255		2444
2256	=back	2445	=back
2257		2446
2258
2259	=head1 SUBCLASSING AnyEvent::Handle	2447	=head1 SUBCLASSING AnyEvent::Handle
2260		2448
2261	In many cases, you might want to subclass AnyEvent::Handle.	2449	In many cases, you might want to subclass AnyEvent::Handle.
2262		2450
2263	To make this easier, a given version of AnyEvent::Handle uses these	2451	To make this easier, a given version of AnyEvent::Handle uses these
…		…
2289		2477
2290	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2478	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
2291		2479
2292	=cut	2480	=cut
2293		2481
2294	1; # End of AnyEvent::Handle	2482	1
		2483

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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents): Revision 1.198 by root, Tue Aug 31 01:03:37 2010 UTC vs. Revision 1.234 by root, Wed Apr 18 09:44:10 2012 UTC

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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.198 by root, Tue Aug 31 01:03:37 2010 UTC vs.
Revision 1.234 by root, Wed Apr 18 09:44:10 2012 UTC