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Revision 1.3 by elmex, Sun Apr 27 19:00:33 2008 UTC vs.
Revision 1.176 by root, Sun Aug 9 00:20:35 2009 UTC

1	package AnyEvent::Handle;
2
3	use warnings;
4	use strict;
5
6	use AnyEvent;
7	use IO::Handle;
8	use Errno qw/EAGAIN EINTR/;
9
10	=head1 NAME	1	=head1 NAME
11		2
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13		4
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut	5	=cut
19		6
20	our $VERSION = '0.01';	7	our $VERSION = 4.92;
21		8
22	=head1 SYNOPSIS	9	=head1 SYNOPSIS
23		10
24	use AnyEvent;	11	use AnyEvent;
25	use AnyEvent::Handle;	12	use AnyEvent::Handle;
26		13
27	my $cv = AnyEvent->condvar;	14	my $cv = AnyEvent->condvar;
28		15
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	16	my $hdl; $hdl = new AnyEvent::Handle
		17	fh => \*STDIN,
		18	on_error => sub {
		19	my ($hdl, $fatal, $msg) = @_;
		20	warn "got error $msg\n";
		21	$hdl->destroy;
		22	$cv->send;
		23	);
30		24
31	$ae_fh->on_eof (sub { $cv->broadcast });	25	# send some request line
		26	$hdl->push_write ("getinfo\015\012");
32		27
33	$ae_fh->readlines (sub {	28	# read the response line
		29	$hdl->push_read (line => sub {
34	my ($ae_fh, @lines) = @_;	30	my ($hdl, $line) = @_;
35	for (@lines) {	31	warn "got line <$line>\n";
		32	$cv->send;
		33	});
		34
		35	$cv->recv;
		36
		37	=head1 DESCRIPTION
		38
		39	This module is a helper module to make it easier to do event-based I/O on
		40	filehandles.
		41
		42	The L<AnyEvent::Intro> tutorial contains some well-documented
		43	AnyEvent::Handle examples.
		44
		45	In the following, when the documentation refers to of "bytes" then this
		46	means characters. As sysread and syswrite are used for all I/O, their
		47	treatment of characters applies to this module as well.
		48
		49	At the very minimum, you should specify C<fh> or C<connect>, and the
		50	C<on_error> callback.
		51
		52	All callbacks will be invoked with the handle object as their first
		53	argument.
		54
		55	=cut
		56
		57	package AnyEvent::Handle;
		58
		59	use Scalar::Util ();
		60	use List::Util ();
		61	use Carp ();
		62	use Errno qw(EAGAIN EINTR);
		63
		64	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		65	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		66
		67	=head1 METHODS
		68
		69	=over 4
		70
		71	=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
		72
		73	The constructor supports these arguments (all as C<< key => value >> pairs).
		74
		75	=over 4
		76
		77	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		78
		79	The filehandle this L<AnyEvent::Handle> object will operate on.
		80	NOTE: The filehandle will be set to non-blocking mode (using
		81	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		82	that mode.
		83
		84	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		85
		86	Try to connect to the specified host and service (port), using
		87	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		88	default C<peername>.
		89
		90	You have to specify either this parameter, or C<fh>, above.
		91
		92	It is possible to push requests on the read and write queues, and modify
		93	properties of the stream, even while AnyEvent::Handle is connecting.
		94
		95	When this parameter is specified, then the C<on_prepare>,
		96	C<on_connect_error> and C<on_connect> callbacks will be called under the
		97	appropriate circumstances:
		98
		99	=over 4
		100
		101	=item on_prepare => $cb->($handle)
		102
		103	This (rarely used) callback is called before a new connection is
		104	attempted, but after the file handle has been created. It could be used to
		105	prepare the file handle with parameters required for the actual connect
		106	(as opposed to settings that can be changed when the connection is already
		107	established).
		108
		109	The return value of this callback should be the connect timeout value in
		110	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		111	timeout is to be used).
		112
		113	=item on_connect => $cb->($handle, $host, $port, $retry->())
		114
		115	This callback is called when a connection has been successfully established.
		116
		117	The actual numeric host and port (the socket peername) are passed as
		118	parameters, together with a retry callback.
		119
		120	When, for some reason, the handle is not acceptable, then calling
		121	C<$retry> will continue with the next conenction target (in case of
		122	multi-homed hosts or SRV records there can be multiple connection
		123	endpoints). When it is called then the read and write queues, eof status,
		124	tls status and similar properties of the handle are being reset.
		125
		126	In most cases, ignoring the C<$retry> parameter is the way to go.
		127
		128	=item on_connect_error => $cb->($handle, $message)
		129
		130	This callback is called when the conenction could not be
		131	established. C<$!> will contain the relevant error code, and C<$message> a
		132	message describing it (usually the same as C<"$!">).
		133
		134	If this callback isn't specified, then C<on_error> will be called with a
		135	fatal error instead.
		136
		137	=back
		138
		139	=item on_error => $cb->($handle, $fatal, $message)
		140
		141	This is the error callback, which is called when, well, some error
		142	occured, such as not being able to resolve the hostname, failure to
		143	connect or a read error.
		144
		145	Some errors are fatal (which is indicated by C<$fatal> being true). On
		146	fatal errors the handle object will be destroyed (by a call to C<< ->
		147	destroy >>) after invoking the error callback (which means you are free to
		148	examine the handle object). Examples of fatal errors are an EOF condition
		149	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		150	cases where the other side can close the connection at their will it is
		151	often easiest to not report C<EPIPE> errors in this callback.
		152
		153	AnyEvent::Handle tries to find an appropriate error code for you to check
		154	against, but in some cases (TLS errors), this does not work well. It is
		155	recommended to always output the C<$message> argument in human-readable
		156	error messages (it's usually the same as C<"$!">).
		157
		158	Non-fatal errors can be retried by simply returning, but it is recommended
		159	to simply ignore this parameter and instead abondon the handle object
		160	when this callback is invoked. Examples of non-fatal errors are timeouts
		161	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		162
		163	On callback entrance, the value of C<$!> contains the operating system
		164	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		165	C<EPROTO>).
		166
		167	While not mandatory, it is I<highly> recommended to set this callback, as
		168	you will not be notified of errors otherwise. The default simply calls
		169	C<croak>.
		170
		171	=item on_read => $cb->($handle)
		172
		173	This sets the default read callback, which is called when data arrives
		174	and no read request is in the queue (unlike read queue callbacks, this
		175	callback will only be called when at least one octet of data is in the
		176	read buffer).
		177
		178	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		179	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		180	must not enlarge or modify the read buffer, you can only remove data at
		181	the beginning from it.
		182
		183	When an EOF condition is detected then AnyEvent::Handle will first try to
		184	feed all the remaining data to the queued callbacks and C<on_read> before
		185	calling the C<on_eof> callback. If no progress can be made, then a fatal
		186	error will be raised (with C<$!> set to C<EPIPE>).
		187
		188	Note that, unlike requests in the read queue, an C<on_read> callback
		189	doesn't mean you I<require> some data: if there is an EOF and there
		190	are outstanding read requests then an error will be flagged. With an
		191	C<on_read> callback, the C<on_eof> callback will be invoked.
		192
		193	=item on_eof => $cb->($handle)
		194
		195	Set the callback to be called when an end-of-file condition is detected,
		196	i.e. in the case of a socket, when the other side has closed the
		197	connection cleanly, and there are no outstanding read requests in the
		198	queue (if there are read requests, then an EOF counts as an unexpected
		199	connection close and will be flagged as an error).
		200
		201	For sockets, this just means that the other side has stopped sending data,
		202	you can still try to write data, and, in fact, one can return from the EOF
		203	callback and continue writing data, as only the read part has been shut
		204	down.
		205
		206	If an EOF condition has been detected but no C<on_eof> callback has been
		207	set, then a fatal error will be raised with C<$!> set to <0>.
		208
		209	=item on_drain => $cb->($handle)
		210
		211	This sets the callback that is called when the write buffer becomes empty
		212	(or when the callback is set and the buffer is empty already).
		213
		214	To append to the write buffer, use the C<< ->push_write >> method.
		215
		216	This callback is useful when you don't want to put all of your write data
		217	into the queue at once, for example, when you want to write the contents
		218	of some file to the socket you might not want to read the whole file into
		219	memory and push it into the queue, but instead only read more data from
		220	the file when the write queue becomes empty.
		221
		222	=item timeout => $fractional_seconds
		223
		224	=item rtimeout => $fractional_seconds
		225
		226	=item wtimeout => $fractional_seconds
		227
		228	If non-zero, then these enables an "inactivity" timeout: whenever this
		229	many seconds pass without a successful read or write on the underlying
		230	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		231	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		232	error will be raised).
		233
		234	There are three variants of the timeouts that work fully independent
		235	of each other, for both read and write, just read, and just write:
		236	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		237	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		238	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		239
		240	Note that timeout processing is also active when you currently do not have
		241	any outstanding read or write requests: If you plan to keep the connection
		242	idle then you should disable the timout temporarily or ignore the timeout
		243	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		244	restart the timeout.
		245
		246	Zero (the default) disables this timeout.
		247
		248	=item on_timeout => $cb->($handle)
		249
		250	Called whenever the inactivity timeout passes. If you return from this
		251	callback, then the timeout will be reset as if some activity had happened,
		252	so this condition is not fatal in any way.
		253
		254	=item rbuf_max => <bytes>
		255
		256	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		257	when the read buffer ever (strictly) exceeds this size. This is useful to
		258	avoid some forms of denial-of-service attacks.
		259
		260	For example, a server accepting connections from untrusted sources should
		261	be configured to accept only so-and-so much data that it cannot act on
		262	(for example, when expecting a line, an attacker could send an unlimited
		263	amount of data without a callback ever being called as long as the line
		264	isn't finished).
		265
		266	=item autocork => <boolean>
		267
		268	When disabled (the default), then C<push_write> will try to immediately
		269	write the data to the handle, if possible. This avoids having to register
		270	a write watcher and wait for the next event loop iteration, but can
		271	be inefficient if you write multiple small chunks (on the wire, this
		272	disadvantage is usually avoided by your kernel's nagle algorithm, see
		273	C<no_delay>, but this option can save costly syscalls).
		274
		275	When enabled, then writes will always be queued till the next event loop
		276	iteration. This is efficient when you do many small writes per iteration,
		277	but less efficient when you do a single write only per iteration (or when
		278	the write buffer often is full). It also increases write latency.
		279
		280	=item no_delay => <boolean>
		281
		282	When doing small writes on sockets, your operating system kernel might
		283	wait a bit for more data before actually sending it out. This is called
		284	the Nagle algorithm, and usually it is beneficial.
		285
		286	In some situations you want as low a delay as possible, which can be
		287	accomplishd by setting this option to a true value.
		288
		289	The default is your opertaing system's default behaviour (most likely
		290	enabled), this option explicitly enables or disables it, if possible.
		291
		292	=item read_size => <bytes>
		293
		294	The default read block size (the amount of bytes this module will
		295	try to read during each loop iteration, which affects memory
		296	requirements). Default: C<8192>.
		297
		298	=item low_water_mark => <bytes>
		299
		300	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		301	buffer: If the write reaches this size or gets even samller it is
		302	considered empty.
		303
		304	Sometimes it can be beneficial (for performance reasons) to add data to
		305	the write buffer before it is fully drained, but this is a rare case, as
		306	the operating system kernel usually buffers data as well, so the default
		307	is good in almost all cases.
		308
		309	=item linger => <seconds>
		310
		311	If non-zero (default: C<3600>), then the destructor of the
		312	AnyEvent::Handle object will check whether there is still outstanding
		313	write data and will install a watcher that will write this data to the
		314	socket. No errors will be reported (this mostly matches how the operating
		315	system treats outstanding data at socket close time).
		316
		317	This will not work for partial TLS data that could not be encoded
		318	yet. This data will be lost. Calling the C<stoptls> method in time might
		319	help.
		320
		321	=item peername => $string
		322
		323	A string used to identify the remote site - usually the DNS hostname
		324	(I<not> IDN!) used to create the connection, rarely the IP address.
		325
		326	Apart from being useful in error messages, this string is also used in TLS
		327	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		328	verification will be skipped when C<peername> is not specified or
		329	C<undef>.
		330
		331	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		332
		333	When this parameter is given, it enables TLS (SSL) mode, that means
		334	AnyEvent will start a TLS handshake as soon as the conenction has been
		335	established and will transparently encrypt/decrypt data afterwards.
		336
		337	All TLS protocol errors will be signalled as C<EPROTO>, with an
		338	appropriate error message.
		339
		340	TLS mode requires Net::SSLeay to be installed (it will be loaded
		341	automatically when you try to create a TLS handle): this module doesn't
		342	have a dependency on that module, so if your module requires it, you have
		343	to add the dependency yourself.
		344
		345	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		346	C<accept>, and for the TLS client side of a connection, use C<connect>
		347	mode.
		348
		349	You can also provide your own TLS connection object, but you have
		350	to make sure that you call either C<Net::SSLeay::set_connect_state>
		351	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		352	AnyEvent::Handle. Also, this module will take ownership of this connection
		353	object.
		354
		355	At some future point, AnyEvent::Handle might switch to another TLS
		356	implementation, then the option to use your own session object will go
		357	away.
		358
		359	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		360	passing in the wrong integer will lead to certain crash. This most often
		361	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		362	segmentation fault.
		363
		364	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		365
		366	=item tls_ctx => $anyevent_tls
		367
		368	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		369	(unless a connection object was specified directly). If this parameter is
		370	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		371
		372	Instead of an object, you can also specify a hash reference with C<< key
		373	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		374	new TLS context object.
		375
		376	=item on_starttls => $cb->($handle, $success[, $error_message])
		377
		378	This callback will be invoked when the TLS/SSL handshake has finished. If
		379	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		380	(C<on_stoptls> will not be called in this case).
		381
		382	The session in C<< $handle->{tls} >> can still be examined in this
		383	callback, even when the handshake was not successful.
		384
		385	TLS handshake failures will not cause C<on_error> to be invoked when this
		386	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		387
		388	Without this callback, handshake failures lead to C<on_error> being
		389	called, as normal.
		390
		391	Note that you cannot call C<starttls> right again in this callback. If you
		392	need to do that, start an zero-second timer instead whose callback can
		393	then call C<< ->starttls >> again.
		394
		395	=item on_stoptls => $cb->($handle)
		396
		397	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		398	set, then it will be invoked after freeing the TLS session. If it is not,
		399	then a TLS shutdown condition will be treated like a normal EOF condition
		400	on the handle.
		401
		402	The session in C<< $handle->{tls} >> can still be examined in this
		403	callback.
		404
		405	This callback will only be called on TLS shutdowns, not when the
		406	underlying handle signals EOF.
		407
		408	=item json => JSON or JSON::XS object
		409
		410	This is the json coder object used by the C<json> read and write types.
		411
		412	If you don't supply it, then AnyEvent::Handle will create and use a
		413	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		414	texts.
		415
		416	Note that you are responsible to depend on the JSON module if you want to
		417	use this functionality, as AnyEvent does not have a dependency itself.
		418
		419	=back
		420
		421	=cut
		422
		423	sub new {
		424	my $class = shift;
		425	my $self = bless { @_ }, $class;
		426
		427	if ($self->{fh}) {
		428	$self->_start;
		429	return unless $self->{fh}; # could be gone by now
		430
		431	} elsif ($self->{connect}) {
		432	require AnyEvent::Socket;
		433
		434	$self->{peername} = $self->{connect}[0]
		435	unless exists $self->{peername};
		436
		437	$self->{_skip_drain_rbuf} = 1;
		438
		439	{
		440	Scalar::Util::weaken (my $self = $self);
		441
		442	$self->{_connect} =
		443	AnyEvent::Socket::tcp_connect (
		444	$self->{connect}[0],
		445	$self->{connect}[1],
		446	sub {
		447	my ($fh, $host, $port, $retry) = @_;
		448
		449	if ($fh) {
		450	$self->{fh} = $fh;
		451
		452	delete $self->{_skip_drain_rbuf};
		453	$self->_start;
		454
		455	$self->{on_connect}
		456	and $self->{on_connect}($self, $host, $port, sub {
		457	delete @$self{qw(fh _tw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		458	$self->{_skip_drain_rbuf} = 1;
		459	&$retry;
		460	});
		461
		462	} else {
		463	if ($self->{on_connect_error}) {
		464	$self->{on_connect_error}($self, "$!");
		465	$self->destroy;
		466	} else {
		467	$self->_error ($!, 1);
		468	}
		469	}
		470	},
		471	sub {
		472	local $self->{fh} = $_[0];
		473
		474	$self->{on_prepare}
		475	? $self->{on_prepare}->($self)
		476	: ()
		477	}
		478	);
		479	}
		480
		481	} else {
		482	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		483	}
		484
		485	$self
		486	}
		487
		488	sub _start {
		489	my ($self) = @_;
		490
		491	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		492
		493	$self->{_activity} =
		494	$self->{_ractivity} =
		495	$self->{_wactivity} = AE::now;
		496
		497	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		498	$self->rtimeout (delete $self->{rtimeout}) if $self->{rtimeout};
		499	$self->wtimeout (delete $self->{wtimeout}) if $self->{wtimeout};
		500
		501	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		502
		503	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		504	if $self->{tls};
		505
		506	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		507
		508	$self->start_read
		509	if $self->{on_read} || @{ $self->{_queue} };
		510
		511	$self->_drain_wbuf;
		512	}
		513
		514	#sub _shutdown {
		515	# my ($self) = @_;
		516	#
		517	# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
		518	# $self->{_eof} = 1; # tell starttls et. al to stop trying
		519	#
		520	# &_freetls;
		521	#}
		522
		523	sub _error {
		524	my ($self, $errno, $fatal, $message) = @_;
		525
		526	$! = $errno;
		527	$message ||= "$!";
		528
		529	if ($self->{on_error}) {
		530	$self->{on_error}($self, $fatal, $message);
		531	$self->destroy if $fatal;
		532	} elsif ($self->{fh}) {
		533	$self->destroy;
		534	Carp::croak "AnyEvent::Handle uncaught error: $message";
		535	}
		536	}
		537
		538	=item $fh = $handle->fh
		539
		540	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		541
		542	=cut
		543
		544	sub fh { $_[0]{fh} }
		545
		546	=item $handle->on_error ($cb)
		547
		548	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		549
		550	=cut
		551
		552	sub on_error {
		553	$_[0]{on_error} = $_[1];
		554	}
		555
		556	=item $handle->on_eof ($cb)
		557
		558	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		559
		560	=cut
		561
		562	sub on_eof {
		563	$_[0]{on_eof} = $_[1];
		564	}
		565
		566	=item $handle->on_timeout ($cb)
		567
		568	=item $handle->on_rtimeout ($cb)
		569
		570	=item $handle->on_wtimeout ($cb)
		571
		572	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		573	callback, or disables the callback (but not the timeout) if C<$cb> =
		574	C<undef>. See the C<timeout> constructor argument and method.
		575
		576	=cut
		577
		578	# see below
		579
		580	=item $handle->autocork ($boolean)
		581
		582	Enables or disables the current autocork behaviour (see C<autocork>
		583	constructor argument). Changes will only take effect on the next write.
		584
		585	=cut
		586
		587	sub autocork {
		588	$_[0]{autocork} = $_[1];
		589	}
		590
		591	=item $handle->no_delay ($boolean)
		592
		593	Enables or disables the C<no_delay> setting (see constructor argument of
		594	the same name for details).
		595
		596	=cut
		597
		598	sub no_delay {
		599	$_[0]{no_delay} = $_[1];
		600
		601	eval {
		602	local $SIG{__DIE__};
		603	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]
		604	if $_[0]{fh};
		605	};
		606	}
		607
		608	=item $handle->on_starttls ($cb)
		609
		610	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		611
		612	=cut
		613
		614	sub on_starttls {
		615	$_[0]{on_starttls} = $_[1];
		616	}
		617
		618	=item $handle->on_stoptls ($cb)
		619
		620	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		621
		622	=cut
		623
		624	sub on_starttls {
		625	$_[0]{on_stoptls} = $_[1];
		626	}
		627
		628	=item $handle->rbuf_max ($max_octets)
		629
		630	Configures the C<rbuf_max> setting (C<undef> disables it).
		631
		632	=cut
		633
		634	sub rbuf_max {
		635	$_[0]{rbuf_max} = $_[1];
		636	}
		637
		638	#############################################################################
		639
		640	=item $handle->timeout ($seconds)
		641
		642	=item $handle->rtimeout ($seconds)
		643
		644	=item $handle->wtimeout ($seconds)
		645
		646	Configures (or disables) the inactivity timeout.
		647
		648	=item $handle->timeout_reset
		649
		650	=item $handle->rtimeout_reset
		651
		652	=item $handle->wtimeout_reset
		653
		654	Reset the activity timeout, as if data was received or sent.
		655
		656	These methods are cheap to call.
		657
		658	=cut
		659
		660	for my $dir ("", "r", "w") {
		661	my $timeout = "${dir}timeout";
		662	my $tw = "_${dir}tw";
		663	my $on_timeout = "on_${dir}timeout";
		664	my $activity = "_${dir}activity";
		665	my $cb;
		666
		667	*$on_timeout = sub {
		668	$_[0]{$on_timeout} = $_[1];
		669	};
		670
		671	*$timeout = sub {
		672	my ($self, $new_value) = @_;
		673
		674	$self->{$timeout} = $new_value;
		675	delete $self->{$tw}; &$cb;
		676	};
		677
		678	*{"${dir}timeout_reset"} = sub {
		679	$_[0]{$activity} = AE::now;
		680	};
		681
		682	# main workhorse:
		683	# reset the timeout watcher, as neccessary
		684	# also check for time-outs
		685	$cb = sub {
		686	my ($self) = @_;
		687
		688	if ($self->{$timeout} && $self->{fh}) {
		689	my $NOW = AE::now;
		690
		691	# when would the timeout trigger?
		692	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		693
		694	# now or in the past already?
		695	if ($after <= 0) {
		696	$self->{$activity} = $NOW;
		697
		698	if ($self->{$on_timeout}) {
		699	$self->{$on_timeout}($self);
		700	} else {
		701	$self->_error (Errno::ETIMEDOUT);
		702	}
		703
		704	# callback could have changed timeout value, optimise
		705	return unless $self->{$timeout};
		706
		707	# calculate new after
		708	$after = $self->{$timeout};
		709	}
		710
		711	Scalar::Util::weaken $self;
		712	return unless $self; # ->error could have destroyed $self
		713
		714	$self->{$tw} ||= AE::timer $after, 0, sub {
		715	delete $self->{$tw};
		716	$cb->($self);
36	chomp;	717	};
37	print "Line: $_";	718	} else {
		719	delete $self->{$tw};
		720	}
		721	}
		722	}
		723
		724	#############################################################################
		725
		726	=back
		727
		728	=head2 WRITE QUEUE
		729
		730	AnyEvent::Handle manages two queues per handle, one for writing and one
		731	for reading.
		732
		733	The write queue is very simple: you can add data to its end, and
		734	AnyEvent::Handle will automatically try to get rid of it for you.
		735
		736	When data could be written and the write buffer is shorter then the low
		737	water mark, the C<on_drain> callback will be invoked.
		738
		739	=over 4
		740
		741	=item $handle->on_drain ($cb)
		742
		743	Sets the C<on_drain> callback or clears it (see the description of
		744	C<on_drain> in the constructor).
		745
		746	=cut
		747
		748	sub on_drain {
		749	my ($self, $cb) = @_;
		750
		751	$self->{on_drain} = $cb;
		752
		753	$cb->($self)
		754	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		755	}
		756
		757	=item $handle->push_write ($data)
		758
		759	Queues the given scalar to be written. You can push as much data as you
		760	want (only limited by the available memory), as C<AnyEvent::Handle>
		761	buffers it independently of the kernel.
		762
		763	=cut
		764
		765	sub _drain_wbuf {
		766	my ($self) = @_;
		767
		768	if (!$self->{_ww} && length $self->{wbuf}) {
		769
		770	Scalar::Util::weaken $self;
		771
		772	my $cb = sub {
		773	my $len = syswrite $self->{fh}, $self->{wbuf};
		774
		775	if (defined $len) {
		776	substr $self->{wbuf}, 0, $len, "";
		777
		778	$self->{_activity} = $self->{_wactivity} = AE::now;
		779
		780	$self->{on_drain}($self)
		781	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		782	&& $self->{on_drain};
		783
		784	delete $self->{_ww} unless length $self->{wbuf};
		785	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		786	$self->_error ($!, 1);
		787	}
		788	};
		789
		790	# try to write data immediately
		791	$cb->() unless $self->{autocork};
		792
		793	# if still data left in wbuf, we need to poll
		794	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		795	if length $self->{wbuf};
		796	};
		797	}
		798
		799	our %WH;
		800
		801	sub register_write_type($$) {
		802	$WH{$_[0]} = $_[1];
		803	}
		804
		805	sub push_write {
		806	my $self = shift;
		807
		808	if (@_ > 1) {
		809	my $type = shift;
		810
		811	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		812	->($self, @_);
		813	}
		814
		815	if ($self->{tls}) {
		816	$self->{_tls_wbuf} .= $_[0];
		817	&_dotls ($self) if $self->{fh};
		818	} else {
		819	$self->{wbuf} .= $_[0];
		820	$self->_drain_wbuf if $self->{fh};
		821	}
		822	}
		823
		824	=item $handle->push_write (type => @args)
		825
		826	Instead of formatting your data yourself, you can also let this module do
		827	the job by specifying a type and type-specific arguments.
		828
		829	Predefined types are (if you have ideas for additional types, feel free to
		830	drop by and tell us):
		831
		832	=over 4
		833
		834	=item netstring => $string
		835
		836	Formats the given value as netstring
		837	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		838
		839	=cut
		840
		841	register_write_type netstring => sub {
		842	my ($self, $string) = @_;
		843
		844	(length $string) . ":$string,"
		845	};
		846
		847	=item packstring => $format, $data
		848
		849	An octet string prefixed with an encoded length. The encoding C<$format>
		850	uses the same format as a Perl C<pack> format, but must specify a single
		851	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		852	optional C<!>, C<< < >> or C<< > >> modifier).
		853
		854	=cut
		855
		856	register_write_type packstring => sub {
		857	my ($self, $format, $string) = @_;
		858
		859	pack "$format/a*", $string
		860	};
		861
		862	=item json => $array_or_hashref
		863
		864	Encodes the given hash or array reference into a JSON object. Unless you
		865	provide your own JSON object, this means it will be encoded to JSON text
		866	in UTF-8.
		867
		868	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		869	one end of a handle and read them at the other end without using any
		870	additional framing.
		871
		872	The generated JSON text is guaranteed not to contain any newlines: While
		873	this module doesn't need delimiters after or between JSON texts to be
		874	able to read them, many other languages depend on that.
		875
		876	A simple RPC protocol that interoperates easily with others is to send
		877	JSON arrays (or objects, although arrays are usually the better choice as
		878	they mimic how function argument passing works) and a newline after each
		879	JSON text:
		880
		881	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		882	$handle->push_write ("\012");
		883
		884	An AnyEvent::Handle receiver would simply use the C<json> read type and
		885	rely on the fact that the newline will be skipped as leading whitespace:
		886
		887	$handle->push_read (json => sub { my $array = $_[1]; ... });
		888
		889	Other languages could read single lines terminated by a newline and pass
		890	this line into their JSON decoder of choice.
		891
		892	=cut
		893
		894	register_write_type json => sub {
		895	my ($self, $ref) = @_;
		896
		897	require JSON;
		898
		899	$self->{json} ? $self->{json}->encode ($ref)
		900	: JSON::encode_json ($ref)
		901	};
		902
		903	=item storable => $reference
		904
		905	Freezes the given reference using L<Storable> and writes it to the
		906	handle. Uses the C<nfreeze> format.
		907
		908	=cut
		909
		910	register_write_type storable => sub {
		911	my ($self, $ref) = @_;
		912
		913	require Storable;
		914
		915	pack "w/a*", Storable::nfreeze ($ref)
		916	};
		917
		918	=back
		919
		920	=item $handle->push_shutdown
		921
		922	Sometimes you know you want to close the socket after writing your data
		923	before it was actually written. One way to do that is to replace your
		924	C<on_drain> handler by a callback that shuts down the socket (and set
		925	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		926	replaces the C<on_drain> callback with:
		927
		928	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		929
		930	This simply shuts down the write side and signals an EOF condition to the
		931	the peer.
		932
		933	You can rely on the normal read queue and C<on_eof> handling
		934	afterwards. This is the cleanest way to close a connection.
		935
		936	=cut
		937
		938	sub push_shutdown {
		939	my ($self) = @_;
		940
		941	delete $self->{low_water_mark};
		942	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		943	}
		944
		945	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		946
		947	This function (not method) lets you add your own types to C<push_write>.
		948	Whenever the given C<type> is used, C<push_write> will invoke the code
		949	reference with the handle object and the remaining arguments.
		950
		951	The code reference is supposed to return a single octet string that will
		952	be appended to the write buffer.
		953
		954	Note that this is a function, and all types registered this way will be
		955	global, so try to use unique names.
		956
		957	=cut
		958
		959	#############################################################################
		960
		961	=back
		962
		963	=head2 READ QUEUE
		964
		965	AnyEvent::Handle manages two queues per handle, one for writing and one
		966	for reading.
		967
		968	The read queue is more complex than the write queue. It can be used in two
		969	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		970	a queue.
		971
		972	In the simple case, you just install an C<on_read> callback and whenever
		973	new data arrives, it will be called. You can then remove some data (if
		974	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		975	leave the data there if you want to accumulate more (e.g. when only a
		976	partial message has been received so far).
		977
		978	In the more complex case, you want to queue multiple callbacks. In this
		979	case, AnyEvent::Handle will call the first queued callback each time new
		980	data arrives (also the first time it is queued) and removes it when it has
		981	done its job (see C<push_read>, below).
		982
		983	This way you can, for example, push three line-reads, followed by reading
		984	a chunk of data, and AnyEvent::Handle will execute them in order.
		985
		986	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		987	the specified number of bytes which give an XML datagram.
		988
		989	# in the default state, expect some header bytes
		990	$handle->on_read (sub {
		991	# some data is here, now queue the length-header-read (4 octets)
		992	shift->unshift_read (chunk => 4, sub {
		993	# header arrived, decode
		994	my $len = unpack "N", $_[1];
		995
		996	# now read the payload
		997	shift->unshift_read (chunk => $len, sub {
		998	my $xml = $_[1];
		999	# handle xml
		1000	});
		1001	});
		1002	});
		1003
		1004	Example 2: Implement a client for a protocol that replies either with "OK"
		1005	and another line or "ERROR" for the first request that is sent, and 64
		1006	bytes for the second request. Due to the availability of a queue, we can
		1007	just pipeline sending both requests and manipulate the queue as necessary
		1008	in the callbacks.
		1009
		1010	When the first callback is called and sees an "OK" response, it will
		1011	C<unshift> another line-read. This line-read will be queued I<before> the
		1012	64-byte chunk callback.
		1013
		1014	# request one, returns either "OK + extra line" or "ERROR"
		1015	$handle->push_write ("request 1\015\012");
		1016
		1017	# we expect "ERROR" or "OK" as response, so push a line read
		1018	$handle->push_read (line => sub {
		1019	# if we got an "OK", we have to _prepend_ another line,
		1020	# so it will be read before the second request reads its 64 bytes
		1021	# which are already in the queue when this callback is called
		1022	# we don't do this in case we got an error
		1023	if ($_[1] eq "OK") {
		1024	$_[0]->unshift_read (line => sub {
		1025	my $response = $_[1];
		1026	...
		1027	});
38	}	1028	}
39	});	1029	});
40		1030
41	# or use the constructor to pass the callback:	1031	# request two, simply returns 64 octets
		1032	$handle->push_write ("request 2\015\012");
42		1033
43	my $ae_fh2 =	1034	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1035	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1036	my $response = $_[1];
46	on_eof => sub {	1037	...
47	$cv->broadcast;	1038	});
48	},	1039
49	on_readline => sub {	1040	=over 4
50	my ($ae_fh, @lines) = @_;	1041
51	for (@lines) {	1042	=cut
52	chomp;	1043
53	print "Line: $_";	1044	sub _drain_rbuf {
		1045	my ($self) = @_;
		1046
		1047	# avoid recursion
		1048	return if $self->{_skip_drain_rbuf};
		1049	local $self->{_skip_drain_rbuf} = 1;
		1050
		1051	while () {
		1052	# we need to use a separate tls read buffer, as we must not receive data while
		1053	# we are draining the buffer, and this can only happen with TLS.
		1054	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1055	if exists $self->{_tls_rbuf};
		1056
		1057	my $len = length $self->{rbuf};
		1058
		1059	if (my $cb = shift @{ $self->{_queue} }) {
		1060	unless ($cb->($self)) {
		1061	# no progress can be made
		1062	# (not enough data and no data forthcoming)
		1063	$self->_error (Errno::EPIPE, 1), return
		1064	if $self->{_eof};
		1065
		1066	unshift @{ $self->{_queue} }, $cb;
54	}	1067	last;
55	}	1068	}
56	);
57
58	$cv->wait;
59
60	=head1 DESCRIPTION
61
62	This module is a helper module to make it easier to do non-blocking I/O
63	on filehandles (and sockets, see L<AnyEvent::Socket>).
64
65	The event loop is provided by L<AnyEvent>.
66
67	=head1 METHODS
68
69	=over 4
70
71	=item B<new (%args)>
72
73	The constructor has these arguments:
74
75	=over 4
76
77	=item fh => $filehandle
78
79	The filehandle this L<AnyEvent::Handle> object will operate on.
80
81	NOTE: The filehandle will be set to non-blocking.
82
83	=item read_block_size => $size
84
85	The default read block size use for reads via the C<on_read>
86	method.
87
88	=item on_read => $cb
89
90	=item on_eof => $cb
91
92	=item on_error => $cb
93
94	These are shortcuts, that will call the corresponding method and set the callback to C<$cb>.
95
96	=item on_readline => $cb
97
98	The C<readlines> method is called with the default seperator and C<$cb> as callback
99	for you.
100
101	=back
102
103	=cut
104
105	sub new {
106	my $this = shift;
107	my $class = ref($this) || $this;
108	my $self = {
109	read_block_size => 4096,
110	rbuf => '',
111	@_
112	};
113	bless $self, $class;
114
115	$self->{fh}->blocking (0) if $self->{fh};
116
117	if ($self->{on_read}) {
118	$self->on_read ($self->{on_read});
119
120	} elsif ($self->{on_readline}) {	1069	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1070	last unless $len;
122		1071
		1072	$self->{on_read}($self);
		1073
		1074	if (
		1075	$len == length $self->{rbuf} # if no data has been consumed
		1076	&& !@{ $self->{_queue} } # and the queue is still empty
		1077	&& $self->{on_read} # but we still have on_read
		1078	) {
		1079	# no further data will arrive
		1080	# so no progress can be made
		1081	$self->_error (Errno::EPIPE, 1), return
		1082	if $self->{_eof};
		1083
		1084	last; # more data might arrive
		1085	}
		1086	} else {
		1087	# read side becomes idle
		1088	delete $self->{_rw} unless $self->{tls};
		1089	last;
		1090	}
		1091	}
		1092
123	} elsif ($self->{on_eof}) {	1093	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1094	$self->{on_eof}
		1095	? $self->{on_eof}($self)
		1096	: $self->_error (0, 1, "Unexpected end-of-file");
125		1097
126	} elsif ($self->{on_error}) {	1098	return;
127	$self->on_eof ($self->{on_error});
128	}	1099	}
129		1100
130	return $self	1101	if (
131	}	1102	defined $self->{rbuf_max}
		1103	&& $self->{rbuf_max} < length $self->{rbuf}
		1104	) {
		1105	$self->_error (Errno::ENOSPC, 1), return;
		1106	}
132		1107
133	=item B<fh>	1108	# may need to restart read watcher
		1109	unless ($self->{_rw}) {
		1110	$self->start_read
		1111	if $self->{on_read} || @{ $self->{_queue} };
		1112	}
		1113	}
134		1114
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1115	=item $handle->on_read ($cb)
136		1116
137	=cut	1117	This replaces the currently set C<on_read> callback, or clears it (when
138		1118	the new callback is C<undef>). See the description of C<on_read> in the
139	sub fh { $_[0]->{fh} }	1119	constructor.
140
141	=item B<on_read ($callback)>
142
143	This method installs a C<$callback> that will be called
144	when new data arrived. You can access the read buffer via the C<rbuf>
145	method (see below).
146
147	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
148		1120
149	=cut	1121	=cut
150		1122
151	sub on_read {	1123	sub on_read {
152	my ($self, $cb) = @_;	1124	my ($self, $cb) = @_;
		1125
153	$self->{on_read} = $cb;	1126	$self->{on_read} = $cb;
		1127	$self->_drain_rbuf if $cb;
		1128	}
154		1129
155	unless (defined $self->{on_read}) {	1130	=item $handle->rbuf
156	delete $self->{on_read_w};	1131
		1132	Returns the read buffer (as a modifiable lvalue).
		1133
		1134	You can access the read buffer directly as the C<< ->{rbuf} >>
		1135	member, if you want. However, the only operation allowed on the
		1136	read buffer (apart from looking at it) is removing data from its
		1137	beginning. Otherwise modifying or appending to it is not allowed and will
		1138	lead to hard-to-track-down bugs.
		1139
		1140	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1141	C<push_read> or C<unshift_read> methods are used. The other read methods
		1142	automatically manage the read buffer.
		1143
		1144	=cut
		1145
		1146	sub rbuf : lvalue {
		1147	$_[0]{rbuf}
		1148	}
		1149
		1150	=item $handle->push_read ($cb)
		1151
		1152	=item $handle->unshift_read ($cb)
		1153
		1154	Append the given callback to the end of the queue (C<push_read>) or
		1155	prepend it (C<unshift_read>).
		1156
		1157	The callback is called each time some additional read data arrives.
		1158
		1159	It must check whether enough data is in the read buffer already.
		1160
		1161	If not enough data is available, it must return the empty list or a false
		1162	value, in which case it will be called repeatedly until enough data is
		1163	available (or an error condition is detected).
		1164
		1165	If enough data was available, then the callback must remove all data it is
		1166	interested in (which can be none at all) and return a true value. After returning
		1167	true, it will be removed from the queue.
		1168
		1169	=cut
		1170
		1171	our %RH;
		1172
		1173	sub register_read_type($$) {
		1174	$RH{$_[0]} = $_[1];
		1175	}
		1176
		1177	sub push_read {
		1178	my $self = shift;
		1179	my $cb = pop;
		1180
		1181	if (@_) {
		1182	my $type = shift;
		1183
		1184	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		1185	->($self, $cb, @_);
		1186	}
		1187
		1188	push @{ $self->{_queue} }, $cb;
		1189	$self->_drain_rbuf;
		1190	}
		1191
		1192	sub unshift_read {
		1193	my $self = shift;
		1194	my $cb = pop;
		1195
		1196	if (@_) {
		1197	my $type = shift;
		1198
		1199	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1200	->($self, $cb, @_);
		1201	}
		1202
		1203
		1204	unshift @{ $self->{_queue} }, $cb;
		1205	$self->_drain_rbuf;
		1206	}
		1207
		1208	=item $handle->push_read (type => @args, $cb)
		1209
		1210	=item $handle->unshift_read (type => @args, $cb)
		1211
		1212	Instead of providing a callback that parses the data itself you can chose
		1213	between a number of predefined parsing formats, for chunks of data, lines
		1214	etc.
		1215
		1216	Predefined types are (if you have ideas for additional types, feel free to
		1217	drop by and tell us):
		1218
		1219	=over 4
		1220
		1221	=item chunk => $octets, $cb->($handle, $data)
		1222
		1223	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1224	data read to the callback. The callback will never be called with less
		1225	data.
		1226
		1227	Example: read 2 bytes.
		1228
		1229	$handle->push_read (chunk => 2, sub {
		1230	warn "yay ", unpack "H*", $_[1];
		1231	});
		1232
		1233	=cut
		1234
		1235	register_read_type chunk => sub {
		1236	my ($self, $cb, $len) = @_;
		1237
		1238	sub {
		1239	$len <= length $_[0]{rbuf} or return;
		1240	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1241	1
		1242	}
		1243	};
		1244
		1245	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1246
		1247	The callback will be called only once a full line (including the end of
		1248	line marker, C<$eol>) has been read. This line (excluding the end of line
		1249	marker) will be passed to the callback as second argument (C<$line>), and
		1250	the end of line marker as the third argument (C<$eol>).
		1251
		1252	The end of line marker, C<$eol>, can be either a string, in which case it
		1253	will be interpreted as a fixed record end marker, or it can be a regex
		1254	object (e.g. created by C<qr>), in which case it is interpreted as a
		1255	regular expression.
		1256
		1257	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1258	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1259	protocols).
		1260
		1261	Partial lines at the end of the stream will never be returned, as they are
		1262	not marked by the end of line marker.
		1263
		1264	=cut
		1265
		1266	register_read_type line => sub {
		1267	my ($self, $cb, $eol) = @_;
		1268
		1269	if (@_ < 3) {
		1270	# this is more than twice as fast as the generic code below
		1271	sub {
		1272	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1273
		1274	$cb->($_[0], $1, $2);
		1275	1
		1276	}
		1277	} else {
		1278	$eol = quotemeta $eol unless ref $eol;
		1279	$eol = qr|^(.*?)($eol)|s;
		1280
		1281	sub {
		1282	$_[0]{rbuf} =~ s/$eol// or return;
		1283
		1284	$cb->($_[0], $1, $2);
		1285	1
		1286	}
		1287	}
		1288	};
		1289
		1290	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1291
		1292	Makes a regex match against the regex object C<$accept> and returns
		1293	everything up to and including the match.
		1294
		1295	Example: read a single line terminated by '\n'.
		1296
		1297	$handle->push_read (regex => qr<\n>, sub { ... });
		1298
		1299	If C<$reject> is given and not undef, then it determines when the data is
		1300	to be rejected: it is matched against the data when the C<$accept> regex
		1301	does not match and generates an C<EBADMSG> error when it matches. This is
		1302	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1303	receive buffer overflow).
		1304
		1305	Example: expect a single decimal number followed by whitespace, reject
		1306	anything else (not the use of an anchor).
		1307
		1308	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1309
		1310	If C<$skip> is given and not C<undef>, then it will be matched against
		1311	the receive buffer when neither C<$accept> nor C<$reject> match,
		1312	and everything preceding and including the match will be accepted
		1313	unconditionally. This is useful to skip large amounts of data that you
		1314	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1315	have to start matching from the beginning. This is purely an optimisation
		1316	and is usually worth only when you expect more than a few kilobytes.
		1317
		1318	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1319	expect the header to be very large (it isn't in practise, but...), we use
		1320	a skip regex to skip initial portions. The skip regex is tricky in that
		1321	it only accepts something not ending in either \015 or \012, as these are
		1322	required for the accept regex.
		1323
		1324	$handle->push_read (regex =>
		1325	qr<\015\012\015\012>,
		1326	undef, # no reject
		1327	qr<^.*[^\015\012]>,
		1328	sub { ... });
		1329
		1330	=cut
		1331
		1332	register_read_type regex => sub {
		1333	my ($self, $cb, $accept, $reject, $skip) = @_;
		1334
		1335	my $data;
		1336	my $rbuf = \$self->{rbuf};
		1337
		1338	sub {
		1339	# accept
		1340	if ($$rbuf =~ $accept) {
		1341	$data .= substr $$rbuf, 0, $+[0], "";
		1342	$cb->($self, $data);
		1343	return 1;
		1344	}
		1345
		1346	# reject
		1347	if ($reject && $$rbuf =~ $reject) {
		1348	$self->_error (Errno::EBADMSG);
		1349	}
		1350
		1351	# skip
		1352	if ($skip && $$rbuf =~ $skip) {
		1353	$data .= substr $$rbuf, 0, $+[0], "";
		1354	}
		1355
		1356	()
		1357	}
		1358	};
		1359
		1360	=item netstring => $cb->($handle, $string)
		1361
		1362	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1363
		1364	Throws an error with C<$!> set to EBADMSG on format violations.
		1365
		1366	=cut
		1367
		1368	register_read_type netstring => sub {
		1369	my ($self, $cb) = @_;
		1370
		1371	sub {
		1372	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1373	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1374	$self->_error (Errno::EBADMSG);
		1375	}
157	return;	1376	return;
		1377	}
		1378
		1379	my $len = $1;
		1380
		1381	$self->unshift_read (chunk => $len, sub {
		1382	my $string = $_[1];
		1383	$_[0]->unshift_read (chunk => 1, sub {
		1384	if ($_[1] eq ",") {
		1385	$cb->($_[0], $string);
		1386	} else {
		1387	$self->_error (Errno::EBADMSG);
		1388	}
		1389	});
		1390	});
		1391
		1392	1
		1393	}
		1394	};
		1395
		1396	=item packstring => $format, $cb->($handle, $string)
		1397
		1398	An octet string prefixed with an encoded length. The encoding C<$format>
		1399	uses the same format as a Perl C<pack> format, but must specify a single
		1400	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1401	optional C<!>, C<< < >> or C<< > >> modifier).
		1402
		1403	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1404	EPP uses a prefix of C<N> (4 octtes).
		1405
		1406	Example: read a block of data prefixed by its length in BER-encoded
		1407	format (very efficient).
		1408
		1409	$handle->push_read (packstring => "w", sub {
		1410	my ($handle, $data) = @_;
158	}	1411	});
159		1412
160	$self->{on_read_w} =	1413	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1414
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1415	register_read_type packstring => sub {
		1416	my ($self, $cb, $format) = @_;
		1417
		1418	sub {
		1419	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1420	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1421	or return;
		1422
		1423	$format = length pack $format, $len;
		1424
		1425	# bypass unshift if we already have the remaining chunk
		1426	if ($format + $len <= length $_[0]{rbuf}) {
		1427	my $data = substr $_[0]{rbuf}, $format, $len;
		1428	substr $_[0]{rbuf}, 0, $format + $len, "";
		1429	$cb->($_[0], $data);
		1430	} else {
		1431	# remove prefix
		1432	substr $_[0]{rbuf}, 0, $format, "";
		1433
		1434	# read remaining chunk
		1435	$_[0]->unshift_read (chunk => $len, $cb);
		1436	}
		1437
		1438	1
		1439	}
		1440	};
		1441
		1442	=item json => $cb->($handle, $hash_or_arrayref)
		1443
		1444	Reads a JSON object or array, decodes it and passes it to the
		1445	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1446
		1447	If a C<json> object was passed to the constructor, then that will be used
		1448	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1449
		1450	This read type uses the incremental parser available with JSON version
		1451	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1452	dependency on your own: this module will load the JSON module, but
		1453	AnyEvent does not depend on it itself.
		1454
		1455	Since JSON texts are fully self-delimiting, the C<json> read and write
		1456	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1457	the C<json> write type description, above, for an actual example.
		1458
		1459	=cut
		1460
		1461	register_read_type json => sub {
		1462	my ($self, $cb) = @_;
		1463
		1464	my $json = $self->{json} ||=
		1465	eval { require JSON::XS; JSON::XS->new->utf8 }
		1466	|| do { require JSON; JSON->new->utf8 };
		1467
		1468	my $data;
163	my $rbuf_len = length $self->{rbuf};	1469	my $rbuf = \$self->{rbuf};
164	my $l;	1470
165	if (defined $self->{read_size}) {	1471	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1472	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1473
		1474	if ($ref) {
		1475	$self->{rbuf} = $json->incr_text;
		1476	$json->incr_text = "";
		1477	$cb->($self, $ref);
		1478
		1479	1
		1480	} elsif ($@) {
		1481	# error case
		1482	$json->incr_skip;
		1483
		1484	$self->{rbuf} = $json->incr_text;
		1485	$json->incr_text = "";
		1486
		1487	$self->_error (Errno::EBADMSG);
		1488
		1489	()
		1490	} else {
		1491	$self->{rbuf} = "";
		1492
		1493	()
		1494	}
		1495	}
		1496	};
		1497
		1498	=item storable => $cb->($handle, $ref)
		1499
		1500	Deserialises a L<Storable> frozen representation as written by the
		1501	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1502	data).
		1503
		1504	Raises C<EBADMSG> error if the data could not be decoded.
		1505
		1506	=cut
		1507
		1508	register_read_type storable => sub {
		1509	my ($self, $cb) = @_;
		1510
		1511	require Storable;
		1512
		1513	sub {
		1514	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1515	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1516	or return;
		1517
		1518	my $format = length pack "w", $len;
		1519
		1520	# bypass unshift if we already have the remaining chunk
		1521	if ($format + $len <= length $_[0]{rbuf}) {
		1522	my $data = substr $_[0]{rbuf}, $format, $len;
		1523	substr $_[0]{rbuf}, 0, $format + $len, "";
		1524	$cb->($_[0], Storable::thaw ($data));
		1525	} else {
		1526	# remove prefix
		1527	substr $_[0]{rbuf}, 0, $format, "";
		1528
		1529	# read remaining chunk
		1530	$_[0]->unshift_read (chunk => $len, sub {
		1531	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1532	$cb->($_[0], $ref);
		1533	} else {
		1534	$self->_error (Errno::EBADMSG);
		1535	}
		1536	});
		1537	}
		1538
		1539	1
		1540	}
		1541	};
		1542
		1543	=back
		1544
		1545	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1546
		1547	This function (not method) lets you add your own types to C<push_read>.
		1548
		1549	Whenever the given C<type> is used, C<push_read> will invoke the code
		1550	reference with the handle object, the callback and the remaining
		1551	arguments.
		1552
		1553	The code reference is supposed to return a callback (usually a closure)
		1554	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1555
		1556	It should invoke the passed callback when it is done reading (remember to
		1557	pass C<$handle> as first argument as all other callbacks do that).
		1558
		1559	Note that this is a function, and all types registered this way will be
		1560	global, so try to use unique names.
		1561
		1562	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1563	search for C<register_read_type>)).
		1564
		1565	=item $handle->stop_read
		1566
		1567	=item $handle->start_read
		1568
		1569	In rare cases you actually do not want to read anything from the
		1570	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1571	any queued callbacks will be executed then. To start reading again, call
		1572	C<start_read>.
		1573
		1574	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1575	you change the C<on_read> callback or push/unshift a read callback, and it
		1576	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1577	there are any read requests in the queue.
		1578
		1579	These methods will have no effect when in TLS mode (as TLS doesn't support
		1580	half-duplex connections).
		1581
		1582	=cut
		1583
		1584	sub stop_read {
		1585	my ($self) = @_;
		1586
		1587	delete $self->{_rw} unless $self->{tls};
		1588	}
		1589
		1590	sub start_read {
		1591	my ($self) = @_;
		1592
		1593	unless ($self->{_rw} || $self->{_eof}) {
		1594	Scalar::Util::weaken $self;
		1595
		1596	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1597	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1598	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1599
		1600	if ($len > 0) {
		1601	$self->{_activity} = $self->{_ractivity} = AE::now;
		1602
		1603	if ($self->{tls}) {
		1604	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1605
		1606	&_dotls ($self);
		1607	} else {
		1608	$self->_drain_rbuf;
		1609	}
		1610
		1611	} elsif (defined $len) {
		1612	delete $self->{_rw};
		1613	$self->{_eof} = 1;
		1614	$self->_drain_rbuf;
		1615
		1616	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1617	return $self->_error ($!, 1);
		1618	}
		1619	};
		1620	}
		1621	}
		1622
		1623	our $ERROR_SYSCALL;
		1624	our $ERROR_WANT_READ;
		1625
		1626	sub _tls_error {
		1627	my ($self, $err) = @_;
		1628
		1629	return $self->_error ($!, 1)
		1630	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1631
		1632	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1633
		1634	# reduce error string to look less scary
		1635	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1636
		1637	if ($self->{_on_starttls}) {
		1638	(delete $self->{_on_starttls})->($self, undef, $err);
		1639	&_freetls;
		1640	} else {
		1641	&_freetls;
		1642	$self->_error (Errno::EPROTO, 1, $err);
		1643	}
		1644	}
		1645
		1646	# poll the write BIO and send the data if applicable
		1647	# also decode read data if possible
		1648	# this is basiclaly our TLS state machine
		1649	# more efficient implementations are possible with openssl,
		1650	# but not with the buggy and incomplete Net::SSLeay.
		1651	sub _dotls {
		1652	my ($self) = @_;
		1653
		1654	my $tmp;
		1655
		1656	if (length $self->{_tls_wbuf}) {
		1657	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1658	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1659	}
		1660
		1661	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1662	return $self->_tls_error ($tmp)
		1663	if $tmp != $ERROR_WANT_READ
		1664	&& ($tmp != $ERROR_SYSCALL || $!);
		1665	}
		1666
		1667	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1668	unless (length $tmp) {
		1669	$self->{_on_starttls}
		1670	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1671	&_freetls;
		1672
		1673	if ($self->{on_stoptls}) {
		1674	$self->{on_stoptls}($self);
		1675	return;
168	} else {	1676	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1677	# let's treat SSL-eof as we treat normal EOF
170	}
171	#d# warn "READL $l [$self->{rbuf}]\n";
172
173	if (not defined $l) {
174	return if $! == EAGAIN || $! == EINTR;
175	$self->{on_error}->($self) if $self->{on_error};
176	delete $self->{on_read_w};	1678	delete $self->{_rw};
177
178	} elsif ($l == 0) {
179	$self->{on_eof}->($self) if $self->{on_eof};
180	delete $self->{on_read_w};
181
182	} else {
183	$self->{on_read}->($self);
184	}
185	});
186	}
187
188	=item B<on_error ($callback)>
189
190	Whenever a read or write operation resulted in an error the C<$callback>
191	will be called.
192
193	The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself.
194	The error is given as errno in C<$!>.
195
196	=cut
197
198	sub on_error {
199	$_[0]->{on_error} = $_[1];
200	}
201
202	=item B<on_eof ($callback)>
203
204	Installs the C<$callback> that will be called when the end of file is
205	encountered in a read operation this C<$callback> will be called. The first
206	argument will be the L<AnyEvent::Handle> object itself.
207
208	=cut
209
210	sub on_eof {
211	$_[0]->{on_eof} = $_[1];
212	}
213
214	=item B<rbuf>
215
216	Returns a reference to the read buffer.
217
218	NOTE: The read buffer should only be used or modified if the C<on_read>
219	method is used directly. The C<read> and C<readlines> methods will provide
220	the read data to their callbacks.
221
222	=cut
223
224	sub rbuf : lvalue {
225	$_[0]->{rbuf}
226	}
227
228	=item B<read ($len, $callback)>
229
230	Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
231	if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
232	object itself and the second argument the read data.
233
234	NOTE: This method will override any callbacks installed via the C<on_read> method.
235
236	=cut
237
238	sub read {
239	my ($self, $len, $cb) = @_;
240
241	$self->{read_cb} = $cb;
242	my $old_blk_size = $self->{read_block_size};
243	$self->{read_block_size} = $len;
244
245	$self->on_read (sub {
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247
248	if ($len == length $_[0]->{rbuf}) {
249	$_[0]->{read_block_size} = $old_blk_size;
250	$_[0]->on_read (undef);
251	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
252	}
253	});
254	}
255
256	=item B<readlines ($callback)>
257
258	=item B<readlines ($sep, $callback)>
259
260	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
261	if C<$sep> is not provided. C<$sep> will be used as part of a regex, so it can be
262	a regex itself and won't be quoted!
263
264	The C<$callback> will be called when at least one
265	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
266	object itself and the rest of the arguments will be the read lines.
267
268	NOTE: This method will override any callbacks installed via the C<on_read> method.
269
270	=cut
271
272	sub readlines {
273	my ($self, $NL, $cb) = @_;
274
275	if (ref $NL) {
276	$cb = $NL;
277	$NL = "\n";
278	}
279
280	$self->{on_readline} = $cb;
281
282	$self->on_read (sub {
283	my @lines;
284	push @lines, $1 while $_[0]->{rbuf} =~ s/(.*)$NL//;
285	$self->{on_readline}->($_[0], @lines);
286	});
287	}
288
289	=item B<write ($data)>
290
291	=item B<write ($callback)>
292
293	=item B<write ($data, $callback)>
294
295	This method will write C<$data> to the filehandle and call the C<$callback>
296	afterwards. If only C<$callback> is provided it will be called when the
297	write buffer becomes empty the next time (or immediately if it already is empty).
298
299	=cut
300
301	sub write {
302	my ($self, $data, $cb) = @_;
303	if (ref $data) { $cb = $data; undef $data }
304	push @{$self->{write_bufs}}, [$data, $cb];
305	$self->_check_writer;
306	}
307
308	sub _check_writer {
309	my ($self) = @_;
310
311	if ($self->{write_w}) {
312	unless ($self->{write_cb}) {
313	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
314	my $wba = shift @{$self->{write_bufs}};
315	$self->{wbuf} .= $wba->[0];	1679	$self->{_eof} = 1;
316	}	1680	}
317	}	1681	}
318	return;	1682
		1683	$self->{_tls_rbuf} .= $tmp;
		1684	$self->_drain_rbuf;
		1685	$self->{tls} or return; # tls session might have gone away in callback
		1686	}
		1687
		1688	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1689	return $self->_tls_error ($tmp)
		1690	if $tmp != $ERROR_WANT_READ
		1691	&& ($tmp != $ERROR_SYSCALL || $!);
		1692
		1693	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1694	$self->{wbuf} .= $tmp;
		1695	$self->_drain_wbuf;
		1696	}
		1697
		1698	$self->{_on_starttls}
		1699	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1700	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1701	}
		1702
		1703	=item $handle->starttls ($tls[, $tls_ctx])
		1704
		1705	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1706	object is created, you can also do that at a later time by calling
		1707	C<starttls>.
		1708
		1709	Starting TLS is currently an asynchronous operation - when you push some
		1710	write data and then call C<< ->starttls >> then TLS negotiation will start
		1711	immediately, after which the queued write data is then sent.
		1712
		1713	The first argument is the same as the C<tls> constructor argument (either
		1714	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1715
		1716	The second argument is the optional C<AnyEvent::TLS> object that is used
		1717	when AnyEvent::Handle has to create its own TLS connection object, or
		1718	a hash reference with C<< key => value >> pairs that will be used to
		1719	construct a new context.
		1720
		1721	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1722	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1723	changed to your liking. Note that the handshake might have already started
		1724	when this function returns.
		1725
		1726	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1727	handshakes on the same stream. Best do not attempt to use the stream after
		1728	stopping TLS.
		1729
		1730	=cut
		1731
		1732	our %TLS_CACHE; #TODO not yet documented, should we?
		1733
		1734	sub starttls {
		1735	my ($self, $tls, $ctx) = @_;
		1736
		1737	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1738	if $self->{tls};
		1739
		1740	$self->{tls} = $tls;
		1741	$self->{tls_ctx} = $ctx if @_ > 2;
		1742
		1743	return unless $self->{fh};
		1744
		1745	require Net::SSLeay;
		1746
		1747	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1748	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1749
		1750	$tls = $self->{tls};
		1751	$ctx = $self->{tls_ctx};
		1752
		1753	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1754
		1755	if ("HASH" eq ref $ctx) {
		1756	require AnyEvent::TLS;
		1757
		1758	if ($ctx->{cache}) {
		1759	my $key = $ctx+0;
		1760	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1761	} else {
		1762	$ctx = new AnyEvent::TLS %$ctx;
		1763	}
		1764	}
319	}	1765
		1766	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1767	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
320		1768
321	my $wba = shift @{$self->{write_bufs}}	1769	# basically, this is deep magic (because SSL_read should have the same issues)
322	or return;	1770	# but the openssl maintainers basically said: "trust us, it just works".
		1771	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1772	# and mismaintained ssleay-module doesn't even offer them).
		1773	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1774	#
		1775	# in short: this is a mess.
		1776	#
		1777	# note that we do not try to keep the length constant between writes as we are required to do.
		1778	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1779	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1780	# have identity issues in that area.
		1781	# Net::SSLeay::CTX_set_mode ($ssl,
		1782	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1783	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1784	Net::SSLeay::CTX_set_mode ($tls, 1|2);
323		1785
324	unless (defined $wba->[0]) {	1786	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
325	$wba->[1]->($self) if $wba->[1];	1787	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
326	$self->_check_writer;	1788
327	return;	1789	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1790
		1791	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1792
		1793	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1794	if $self->{on_starttls};
		1795
		1796	&_dotls; # need to trigger the initial handshake
		1797	$self->start_read; # make sure we actually do read
		1798	}
		1799
		1800	=item $handle->stoptls
		1801
		1802	Shuts down the SSL connection - this makes a proper EOF handshake by
		1803	sending a close notify to the other side, but since OpenSSL doesn't
		1804	support non-blocking shut downs, it is not guarenteed that you can re-use
		1805	the stream afterwards.
		1806
		1807	=cut
		1808
		1809	sub stoptls {
		1810	my ($self) = @_;
		1811
		1812	if ($self->{tls}) {
		1813	Net::SSLeay::shutdown ($self->{tls});
		1814
		1815	&_dotls;
		1816
		1817	# # we don't give a shit. no, we do, but we can't. no...#d#
		1818	# # we, we... have to use openssl :/#d#
		1819	# &_freetls;#d#
		1820	}
		1821	}
		1822
		1823	sub _freetls {
		1824	my ($self) = @_;
		1825
		1826	return unless $self->{tls};
		1827
		1828	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1829	if $self->{tls} > 0;
328	}	1830
		1831	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1832	}
329		1833
330	$self->{wbuf} = $wba->[0];	1834	sub DESTROY {
331	$self->{write_cb} = $wba->[1];	1835	my ($self) = @_;
332		1836
333	$self->{write_w} =	1837	&_freetls;
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1838
		1839	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1840
		1841	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1842	my $fh = delete $self->{fh};
		1843	my $wbuf = delete $self->{wbuf};
		1844
		1845	my @linger;
		1846
		1847	push @linger, AE::io $fh, 1, sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1848	my $len = syswrite $fh, $wbuf, length $wbuf;
336		1849
337	if (not defined $l) {	1850	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	1851	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	1852	} else {
343	substr $self->{wbuf}, 0, $l, '';	1853	@linger = (); # end
344
345	if (length ($self->{wbuf}) == 0) {
346	$self->{write_cb}->($self) if $self->{write_cb};
347
348	delete $self->{write_w};
349	delete $self->{wbuf};
350	delete $self->{write_cb};
351
352	$self->_check_writer;
353	}
354	}	1854	}
355	});	1855	};
		1856	push @linger, AE::timer $linger, 0, sub {
		1857	@linger = ();
		1858	};
		1859	}
		1860	}
		1861
		1862	=item $handle->destroy
		1863
		1864	Shuts down the handle object as much as possible - this call ensures that
		1865	no further callbacks will be invoked and as many resources as possible
		1866	will be freed. Any method you will call on the handle object after
		1867	destroying it in this way will be silently ignored (and it will return the
		1868	empty list).
		1869
		1870	Normally, you can just "forget" any references to an AnyEvent::Handle
		1871	object and it will simply shut down. This works in fatal error and EOF
		1872	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1873	callback, so when you want to destroy the AnyEvent::Handle object from
		1874	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1875	that case.
		1876
		1877	Destroying the handle object in this way has the advantage that callbacks
		1878	will be removed as well, so if those are the only reference holders (as
		1879	is common), then one doesn't need to do anything special to break any
		1880	reference cycles.
		1881
		1882	The handle might still linger in the background and write out remaining
		1883	data, as specified by the C<linger> option, however.
		1884
		1885	=cut
		1886
		1887	sub destroy {
		1888	my ($self) = @_;
		1889
		1890	$self->DESTROY;
		1891	%$self = ();
		1892	bless $self, "AnyEvent::Handle::destroyed";
		1893	}
		1894
		1895	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		1896	#nop
		1897	}
		1898
		1899	=item AnyEvent::Handle::TLS_CTX
		1900
		1901	This function creates and returns the AnyEvent::TLS object used by default
		1902	for TLS mode.
		1903
		1904	The context is created by calling L<AnyEvent::TLS> without any arguments.
		1905
		1906	=cut
		1907
		1908	our $TLS_CTX;
		1909
		1910	sub TLS_CTX() {
		1911	$TLS_CTX ||= do {
		1912	require AnyEvent::TLS;
		1913
		1914	new AnyEvent::TLS
		1915	}
356	}	1916	}
357		1917
358	=back	1918	=back
359		1919
		1920
		1921	=head1 NONFREQUENTLY ASKED QUESTIONS
		1922
		1923	=over 4
		1924
		1925	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1926	still get further invocations!
		1927
		1928	That's because AnyEvent::Handle keeps a reference to itself when handling
		1929	read or write callbacks.
		1930
		1931	It is only safe to "forget" the reference inside EOF or error callbacks,
		1932	from within all other callbacks, you need to explicitly call the C<<
		1933	->destroy >> method.
		1934
		1935	=item I get different callback invocations in TLS mode/Why can't I pause
		1936	reading?
		1937
		1938	Unlike, say, TCP, TLS connections do not consist of two independent
		1939	communication channels, one for each direction. Or put differently. The
		1940	read and write directions are not independent of each other: you cannot
		1941	write data unless you are also prepared to read, and vice versa.
		1942
		1943	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1944	callback invocations when you are not expecting any read data - the reason
		1945	is that AnyEvent::Handle always reads in TLS mode.
		1946
		1947	During the connection, you have to make sure that you always have a
		1948	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1949	connection (or when you no longer want to use it) you can call the
		1950	C<destroy> method.
		1951
		1952	=item How do I read data until the other side closes the connection?
		1953
		1954	If you just want to read your data into a perl scalar, the easiest way
		1955	to achieve this is by setting an C<on_read> callback that does nothing,
		1956	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1957	will be in C<$_[0]{rbuf}>:
		1958
		1959	$handle->on_read (sub { });
		1960	$handle->on_eof (undef);
		1961	$handle->on_error (sub {
		1962	my $data = delete $_[0]{rbuf};
		1963	});
		1964
		1965	The reason to use C<on_error> is that TCP connections, due to latencies
		1966	and packets loss, might get closed quite violently with an error, when in
		1967	fact, all data has been received.
		1968
		1969	It is usually better to use acknowledgements when transferring data,
		1970	to make sure the other side hasn't just died and you got the data
		1971	intact. This is also one reason why so many internet protocols have an
		1972	explicit QUIT command.
		1973
		1974	=item I don't want to destroy the handle too early - how do I wait until
		1975	all data has been written?
		1976
		1977	After writing your last bits of data, set the C<on_drain> callback
		1978	and destroy the handle in there - with the default setting of
		1979	C<low_water_mark> this will be called precisely when all data has been
		1980	written to the socket:
		1981
		1982	$handle->push_write (...);
		1983	$handle->on_drain (sub {
		1984	warn "all data submitted to the kernel\n";
		1985	undef $handle;
		1986	});
		1987
		1988	If you just want to queue some data and then signal EOF to the other side,
		1989	consider using C<< ->push_shutdown >> instead.
		1990
		1991	=item I want to contact a TLS/SSL server, I don't care about security.
		1992
		1993	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		1994	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		1995	parameter:
		1996
		1997	tcp_connect $host, $port, sub {
		1998	my ($fh) = @_;
		1999
		2000	my $handle = new AnyEvent::Handle
		2001	fh => $fh,
		2002	tls => "connect",
		2003	on_error => sub { ... };
		2004
		2005	$handle->push_write (...);
		2006	};
		2007
		2008	=item I want to contact a TLS/SSL server, I do care about security.
		2009
		2010	Then you should additionally enable certificate verification, including
		2011	peername verification, if the protocol you use supports it (see
		2012	L<AnyEvent::TLS>, C<verify_peername>).
		2013
		2014	E.g. for HTTPS:
		2015
		2016	tcp_connect $host, $port, sub {
		2017	my ($fh) = @_;
		2018
		2019	my $handle = new AnyEvent::Handle
		2020	fh => $fh,
		2021	peername => $host,
		2022	tls => "connect",
		2023	tls_ctx => { verify => 1, verify_peername => "https" },
		2024	...
		2025
		2026	Note that you must specify the hostname you connected to (or whatever
		2027	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2028	peername verification will be done.
		2029
		2030	The above will use the system-dependent default set of trusted CA
		2031	certificates. If you want to check against a specific CA, add the
		2032	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2033
		2034	tls_ctx => {
		2035	verify => 1,
		2036	verify_peername => "https",
		2037	ca_file => "my-ca-cert.pem",
		2038	},
		2039
		2040	=item I want to create a TLS/SSL server, how do I do that?
		2041
		2042	Well, you first need to get a server certificate and key. You have
		2043	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2044	self-signed certificate (cheap. check the search engine of your choice,
		2045	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2046	nice program for that purpose).
		2047
		2048	Then create a file with your private key (in PEM format, see
		2049	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2050	file should then look like this:
		2051
		2052	-----BEGIN RSA PRIVATE KEY-----
		2053	...header data
		2054	... lots of base64'y-stuff
		2055	-----END RSA PRIVATE KEY-----
		2056
		2057	-----BEGIN CERTIFICATE-----
		2058	... lots of base64'y-stuff
		2059	-----END CERTIFICATE-----
		2060
		2061	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2062	specify this file as C<cert_file>:
		2063
		2064	tcp_server undef, $port, sub {
		2065	my ($fh) = @_;
		2066
		2067	my $handle = new AnyEvent::Handle
		2068	fh => $fh,
		2069	tls => "accept",
		2070	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2071	...
		2072
		2073	When you have intermediate CA certificates that your clients might not
		2074	know about, just append them to the C<cert_file>.
		2075
		2076	=back
		2077
		2078
		2079	=head1 SUBCLASSING AnyEvent::Handle
		2080
		2081	In many cases, you might want to subclass AnyEvent::Handle.
		2082
		2083	To make this easier, a given version of AnyEvent::Handle uses these
		2084	conventions:
		2085
		2086	=over 4
		2087
		2088	=item * all constructor arguments become object members.
		2089
		2090	At least initially, when you pass a C<tls>-argument to the constructor it
		2091	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2092	mutated later on (for example C<tls> will hold the TLS connection object).
		2093
		2094	=item * other object member names are prefixed with an C<_>.
		2095
		2096	All object members not explicitly documented (internal use) are prefixed
		2097	with an underscore character, so the remaining non-C<_>-namespace is free
		2098	for use for subclasses.
		2099
		2100	=item * all members not documented here and not prefixed with an underscore
		2101	are free to use in subclasses.
		2102
		2103	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2104	member variables, but thats just life, at least it is documented.
		2105
		2106	=back
		2107
360	=head1 AUTHOR	2108	=head1 AUTHOR
361		2109
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	2110	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363
364	=head1 SUPPORT
365
366	You can find documentation for this module with the perldoc command.
367
368	perldoc AnyEvent::Handle
369
370	You can also look for information at:
371
372	=head1 COPYRIGHT & LICENSE
373
374	Copyright 2008 Robin Redeker, all rights reserved.
375
376	This program is free software; you can redistribute it and/or modify it
377	under the same terms as Perl itself.
378		2111
379	=cut	2112	=cut
380		2113
381	1; # End of AnyEvent::Handle	2114	1; # End of AnyEvent::Handle

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