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Revision 1.4 by elmex, Sun Apr 27 20:20:20 2008 UTC vs.
Revision 1.179 by root, Wed Aug 12 15:50:44 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
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut
19
20	our $VERSION = '0.01';
21		4
22	=head1 SYNOPSIS	5	=head1 SYNOPSIS
23		6
24	use AnyEvent;	7	use AnyEvent;
25	use AnyEvent::Handle;	8	use AnyEvent::Handle;
26		9
27	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
28		11
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
		13	fh => \*STDIN,
		14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	warn "got error $msg\n";
		17	$hdl->destroy;
		18	$cv->send;
		19	);
30		20
31	$ae_fh->on_eof (sub { $cv->broadcast });	21	# send some request line
		22	$hdl->push_write ("getinfo\015\012");
32		23
33	$ae_fh->readlines (sub {	24	# read the response line
		25	$hdl->push_read (line => sub {
34	my ($ae_fh, @lines) = @_;	26	my ($hdl, $line) = @_;
35	for (@lines) {	27	warn "got line <$line>\n";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
		32
		33	=head1 DESCRIPTION
		34
		35	This module is a helper module to make it easier to do event-based I/O on
		36	filehandles.
		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
		41	In the following, when the documentation refers to of "bytes" then this
		42	means characters. As sysread and syswrite are used for all I/O, their
		43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
		48	All callbacks will be invoked with the handle object as their first
		49	argument.
		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	=head1 METHODS
		66
		67	=over 4
		68
		69	=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
		70
		71	The constructor supports these arguments (all as C<< key => value >> pairs).
		72
		73	=over 4
		74
		75	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		76
		77	The filehandle this L<AnyEvent::Handle> object will operate on.
		78	NOTE: The filehandle will be set to non-blocking mode (using
		79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
		81
		82	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		83
		84	Try to connect to the specified host and service (port), using
		85	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		86	default C<peername>.
		87
		88	You have to specify either this parameter, or C<fh>, above.
		89
		90	It is possible to push requests on the read and write queues, and modify
		91	properties of the stream, even while AnyEvent::Handle is connecting.
		92
		93	When this parameter is specified, then the C<on_prepare>,
		94	C<on_connect_error> and C<on_connect> callbacks will be called under the
		95	appropriate circumstances:
		96
		97	=over 4
		98
		99	=item on_prepare => $cb->($handle)
		100
		101	This (rarely used) callback is called before a new connection is
		102	attempted, but after the file handle has been created. It could be used to
		103	prepare the file handle with parameters required for the actual connect
		104	(as opposed to settings that can be changed when the connection is already
		105	established).
		106
		107	The return value of this callback should be the connect timeout value in
		108	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		109	timeout is to be used).
		110
		111	=item on_connect => $cb->($handle, $host, $port, $retry->())
		112
		113	This callback is called when a connection has been successfully established.
		114
		115	The actual numeric host and port (the socket peername) are passed as
		116	parameters, together with a retry callback.
		117
		118	When, for some reason, the handle is not acceptable, then calling
		119	C<$retry> will continue with the next conenction target (in case of
		120	multi-homed hosts or SRV records there can be multiple connection
		121	endpoints). When it is called then the read and write queues, eof status,
		122	tls status and similar properties of the handle are being reset.
		123
		124	In most cases, ignoring the C<$retry> parameter is the way to go.
		125
		126	=item on_connect_error => $cb->($handle, $message)
		127
		128	This callback is called when the conenction could not be
		129	established. C<$!> will contain the relevant error code, and C<$message> a
		130	message describing it (usually the same as C<"$!">).
		131
		132	If this callback isn't specified, then C<on_error> will be called with a
		133	fatal error instead.
		134
		135	=back
		136
		137	=item on_error => $cb->($handle, $fatal, $message)
		138
		139	This is the error callback, which is called when, well, some error
		140	occured, such as not being able to resolve the hostname, failure to
		141	connect or a read error.
		142
		143	Some errors are fatal (which is indicated by C<$fatal> being true). On
		144	fatal errors the handle object will be destroyed (by a call to C<< ->
		145	destroy >>) after invoking the error callback (which means you are free to
		146	examine the handle object). Examples of fatal errors are an EOF condition
		147	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		148	cases where the other side can close the connection at their will it is
		149	often easiest to not report C<EPIPE> errors in this callback.
		150
		151	AnyEvent::Handle tries to find an appropriate error code for you to check
		152	against, but in some cases (TLS errors), this does not work well. It is
		153	recommended to always output the C<$message> argument in human-readable
		154	error messages (it's usually the same as C<"$!">).
		155
		156	Non-fatal errors can be retried by simply returning, but it is recommended
		157	to simply ignore this parameter and instead abondon the handle object
		158	when this callback is invoked. Examples of non-fatal errors are timeouts
		159	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		160
		161	On callback entrance, the value of C<$!> contains the operating system
		162	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		163	C<EPROTO>).
		164
		165	While not mandatory, it is I<highly> recommended to set this callback, as
		166	you will not be notified of errors otherwise. The default simply calls
		167	C<croak>.
		168
		169	=item on_read => $cb->($handle)
		170
		171	This sets the default read callback, which is called when data arrives
		172	and no read request is in the queue (unlike read queue callbacks, this
		173	callback will only be called when at least one octet of data is in the
		174	read buffer).
		175
		176	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		177	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		178	must not enlarge or modify the read buffer, you can only remove data at
		179	the beginning from it.
		180
		181	When an EOF condition is detected then AnyEvent::Handle will first try to
		182	feed all the remaining data to the queued callbacks and C<on_read> before
		183	calling the C<on_eof> callback. If no progress can be made, then a fatal
		184	error will be raised (with C<$!> set to C<EPIPE>).
		185
		186	Note that, unlike requests in the read queue, an C<on_read> callback
		187	doesn't mean you I<require> some data: if there is an EOF and there
		188	are outstanding read requests then an error will be flagged. With an
		189	C<on_read> callback, the C<on_eof> callback will be invoked.
		190
		191	=item on_eof => $cb->($handle)
		192
		193	Set the callback to be called when an end-of-file condition is detected,
		194	i.e. in the case of a socket, when the other side has closed the
		195	connection cleanly, and there are no outstanding read requests in the
		196	queue (if there are read requests, then an EOF counts as an unexpected
		197	connection close and will be flagged as an error).
		198
		199	For sockets, this just means that the other side has stopped sending data,
		200	you can still try to write data, and, in fact, one can return from the EOF
		201	callback and continue writing data, as only the read part has been shut
		202	down.
		203
		204	If an EOF condition has been detected but no C<on_eof> callback has been
		205	set, then a fatal error will be raised with C<$!> set to <0>.
		206
		207	=item on_drain => $cb->($handle)
		208
		209	This sets the callback that is called when the write buffer becomes empty
		210	(or when the callback is set and the buffer is empty already).
		211
		212	To append to the write buffer, use the C<< ->push_write >> method.
		213
		214	This callback is useful when you don't want to put all of your write data
		215	into the queue at once, for example, when you want to write the contents
		216	of some file to the socket you might not want to read the whole file into
		217	memory and push it into the queue, but instead only read more data from
		218	the file when the write queue becomes empty.
		219
		220	=item timeout => $fractional_seconds
		221
		222	=item rtimeout => $fractional_seconds
		223
		224	=item wtimeout => $fractional_seconds
		225
		226	If non-zero, then these enables an "inactivity" timeout: whenever this
		227	many seconds pass without a successful read or write on the underlying
		228	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		229	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		230	error will be raised).
		231
		232	There are three variants of the timeouts that work fully independent
		233	of each other, for both read and write, just read, and just write:
		234	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		235	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		236	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		237
		238	Note that timeout processing is also active when you currently do not have
		239	any outstanding read or write requests: If you plan to keep the connection
		240	idle then you should disable the timout temporarily or ignore the timeout
		241	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		242	restart the timeout.
		243
		244	Zero (the default) disables this timeout.
		245
		246	=item on_timeout => $cb->($handle)
		247
		248	Called whenever the inactivity timeout passes. If you return from this
		249	callback, then the timeout will be reset as if some activity had happened,
		250	so this condition is not fatal in any way.
		251
		252	=item rbuf_max => <bytes>
		253
		254	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		255	when the read buffer ever (strictly) exceeds this size. This is useful to
		256	avoid some forms of denial-of-service attacks.
		257
		258	For example, a server accepting connections from untrusted sources should
		259	be configured to accept only so-and-so much data that it cannot act on
		260	(for example, when expecting a line, an attacker could send an unlimited
		261	amount of data without a callback ever being called as long as the line
		262	isn't finished).
		263
		264	=item autocork => <boolean>
		265
		266	When disabled (the default), then C<push_write> will try to immediately
		267	write the data to the handle, if possible. This avoids having to register
		268	a write watcher and wait for the next event loop iteration, but can
		269	be inefficient if you write multiple small chunks (on the wire, this
		270	disadvantage is usually avoided by your kernel's nagle algorithm, see
		271	C<no_delay>, but this option can save costly syscalls).
		272
		273	When enabled, then writes will always be queued till the next event loop
		274	iteration. This is efficient when you do many small writes per iteration,
		275	but less efficient when you do a single write only per iteration (or when
		276	the write buffer often is full). It also increases write latency.
		277
		278	=item no_delay => <boolean>
		279
		280	When doing small writes on sockets, your operating system kernel might
		281	wait a bit for more data before actually sending it out. This is called
		282	the Nagle algorithm, and usually it is beneficial.
		283
		284	In some situations you want as low a delay as possible, which can be
		285	accomplishd by setting this option to a true value.
		286
		287	The default is your opertaing system's default behaviour (most likely
		288	enabled), this option explicitly enables or disables it, if possible.
		289
		290	=item read_size => <bytes>
		291
		292	The default read block size (the amount of bytes this module will
		293	try to read during each loop iteration, which affects memory
		294	requirements). Default: C<8192>.
		295
		296	=item low_water_mark => <bytes>
		297
		298	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		299	buffer: If the write reaches this size or gets even samller it is
		300	considered empty.
		301
		302	Sometimes it can be beneficial (for performance reasons) to add data to
		303	the write buffer before it is fully drained, but this is a rare case, as
		304	the operating system kernel usually buffers data as well, so the default
		305	is good in almost all cases.
		306
		307	=item linger => <seconds>
		308
		309	If non-zero (default: C<3600>), then the destructor of the
		310	AnyEvent::Handle object will check whether there is still outstanding
		311	write data and will install a watcher that will write this data to the
		312	socket. No errors will be reported (this mostly matches how the operating
		313	system treats outstanding data at socket close time).
		314
		315	This will not work for partial TLS data that could not be encoded
		316	yet. This data will be lost. Calling the C<stoptls> method in time might
		317	help.
		318
		319	=item peername => $string
		320
		321	A string used to identify the remote site - usually the DNS hostname
		322	(I<not> IDN!) used to create the connection, rarely the IP address.
		323
		324	Apart from being useful in error messages, this string is also used in TLS
		325	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		326	verification will be skipped when C<peername> is not specified or
		327	C<undef>.
		328
		329	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		330
		331	When this parameter is given, it enables TLS (SSL) mode, that means
		332	AnyEvent will start a TLS handshake as soon as the conenction has been
		333	established and will transparently encrypt/decrypt data afterwards.
		334
		335	All TLS protocol errors will be signalled as C<EPROTO>, with an
		336	appropriate error message.
		337
		338	TLS mode requires Net::SSLeay to be installed (it will be loaded
		339	automatically when you try to create a TLS handle): this module doesn't
		340	have a dependency on that module, so if your module requires it, you have
		341	to add the dependency yourself.
		342
		343	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		344	C<accept>, and for the TLS client side of a connection, use C<connect>
		345	mode.
		346
		347	You can also provide your own TLS connection object, but you have
		348	to make sure that you call either C<Net::SSLeay::set_connect_state>
		349	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		350	AnyEvent::Handle. Also, this module will take ownership of this connection
		351	object.
		352
		353	At some future point, AnyEvent::Handle might switch to another TLS
		354	implementation, then the option to use your own session object will go
		355	away.
		356
		357	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		358	passing in the wrong integer will lead to certain crash. This most often
		359	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		360	segmentation fault.
		361
		362	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		363
		364	=item tls_ctx => $anyevent_tls
		365
		366	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		367	(unless a connection object was specified directly). If this parameter is
		368	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		369
		370	Instead of an object, you can also specify a hash reference with C<< key
		371	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		372	new TLS context object.
		373
		374	=item on_starttls => $cb->($handle, $success[, $error_message])
		375
		376	This callback will be invoked when the TLS/SSL handshake has finished. If
		377	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		378	(C<on_stoptls> will not be called in this case).
		379
		380	The session in C<< $handle->{tls} >> can still be examined in this
		381	callback, even when the handshake was not successful.
		382
		383	TLS handshake failures will not cause C<on_error> to be invoked when this
		384	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		385
		386	Without this callback, handshake failures lead to C<on_error> being
		387	called, as normal.
		388
		389	Note that you cannot call C<starttls> right again in this callback. If you
		390	need to do that, start an zero-second timer instead whose callback can
		391	then call C<< ->starttls >> again.
		392
		393	=item on_stoptls => $cb->($handle)
		394
		395	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		396	set, then it will be invoked after freeing the TLS session. If it is not,
		397	then a TLS shutdown condition will be treated like a normal EOF condition
		398	on the handle.
		399
		400	The session in C<< $handle->{tls} >> can still be examined in this
		401	callback.
		402
		403	This callback will only be called on TLS shutdowns, not when the
		404	underlying handle signals EOF.
		405
		406	=item json => JSON or JSON::XS object
		407
		408	This is the json coder object used by the C<json> read and write types.
		409
		410	If you don't supply it, then AnyEvent::Handle will create and use a
		411	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		412	texts.
		413
		414	Note that you are responsible to depend on the JSON module if you want to
		415	use this functionality, as AnyEvent does not have a dependency itself.
		416
		417	=back
		418
		419	=cut
		420
		421	sub new {
		422	my $class = shift;
		423	my $self = bless { @_ }, $class;
		424
		425	if ($self->{fh}) {
		426	$self->_start;
		427	return unless $self->{fh}; # could be gone by now
		428
		429	} elsif ($self->{connect}) {
		430	require AnyEvent::Socket;
		431
		432	$self->{peername} = $self->{connect}[0]
		433	unless exists $self->{peername};
		434
		435	$self->{_skip_drain_rbuf} = 1;
		436
		437	{
		438	Scalar::Util::weaken (my $self = $self);
		439
		440	$self->{_connect} =
		441	AnyEvent::Socket::tcp_connect (
		442	$self->{connect}[0],
		443	$self->{connect}[1],
		444	sub {
		445	my ($fh, $host, $port, $retry) = @_;
		446
		447	if ($fh) {
		448	$self->{fh} = $fh;
		449
		450	delete $self->{_skip_drain_rbuf};
		451	$self->_start;
		452
		453	$self->{on_connect}
		454	and $self->{on_connect}($self, $host, $port, sub {
		455	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		456	$self->{_skip_drain_rbuf} = 1;
		457	&$retry;
		458	});
		459
		460	} else {
		461	if ($self->{on_connect_error}) {
		462	$self->{on_connect_error}($self, "$!");
		463	$self->destroy;
		464	} else {
		465	$self->_error ($!, 1);
		466	}
		467	}
		468	},
		469	sub {
		470	local $self->{fh} = $_[0];
		471
		472	$self->{on_prepare}
		473	? $self->{on_prepare}->($self)
		474	: ()
		475	}
		476	);
		477	}
		478
		479	} else {
		480	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		481	}
		482
		483	$self
		484	}
		485
		486	sub _start {
		487	my ($self) = @_;
		488
		489	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		490
		491	$self->{_activity} =
		492	$self->{_ractivity} =
		493	$self->{_wactivity} = AE::now;
		494
		495	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		496	$self->rtimeout (delete $self->{rtimeout}) if $self->{rtimeout};
		497	$self->wtimeout (delete $self->{wtimeout}) if $self->{wtimeout};
		498
		499	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		500
		501	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		502	if $self->{tls};
		503
		504	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		505
		506	$self->start_read
		507	if $self->{on_read} || @{ $self->{_queue} };
		508
		509	$self->_drain_wbuf;
		510	}
		511
		512	sub _error {
		513	my ($self, $errno, $fatal, $message) = @_;
		514
		515	$! = $errno;
		516	$message ||= "$!";
		517
		518	if ($self->{on_error}) {
		519	$self->{on_error}($self, $fatal, $message);
		520	$self->destroy if $fatal;
		521	} elsif ($self->{fh}) {
		522	$self->destroy;
		523	Carp::croak "AnyEvent::Handle uncaught error: $message";
		524	}
		525	}
		526
		527	=item $fh = $handle->fh
		528
		529	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		530
		531	=cut
		532
		533	sub fh { $_[0]{fh} }
		534
		535	=item $handle->on_error ($cb)
		536
		537	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		538
		539	=cut
		540
		541	sub on_error {
		542	$_[0]{on_error} = $_[1];
		543	}
		544
		545	=item $handle->on_eof ($cb)
		546
		547	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		548
		549	=cut
		550
		551	sub on_eof {
		552	$_[0]{on_eof} = $_[1];
		553	}
		554
		555	=item $handle->on_timeout ($cb)
		556
		557	=item $handle->on_rtimeout ($cb)
		558
		559	=item $handle->on_wtimeout ($cb)
		560
		561	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		562	callback, or disables the callback (but not the timeout) if C<$cb> =
		563	C<undef>. See the C<timeout> constructor argument and method.
		564
		565	=cut
		566
		567	# see below
		568
		569	=item $handle->autocork ($boolean)
		570
		571	Enables or disables the current autocork behaviour (see C<autocork>
		572	constructor argument). Changes will only take effect on the next write.
		573
		574	=cut
		575
		576	sub autocork {
		577	$_[0]{autocork} = $_[1];
		578	}
		579
		580	=item $handle->no_delay ($boolean)
		581
		582	Enables or disables the C<no_delay> setting (see constructor argument of
		583	the same name for details).
		584
		585	=cut
		586
		587	sub no_delay {
		588	$_[0]{no_delay} = $_[1];
		589
		590	eval {
		591	local $SIG{__DIE__};
		592	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]
		593	if $_[0]{fh};
		594	};
		595	}
		596
		597	=item $handle->on_starttls ($cb)
		598
		599	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		600
		601	=cut
		602
		603	sub on_starttls {
		604	$_[0]{on_starttls} = $_[1];
		605	}
		606
		607	=item $handle->on_stoptls ($cb)
		608
		609	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		610
		611	=cut
		612
		613	sub on_starttls {
		614	$_[0]{on_stoptls} = $_[1];
		615	}
		616
		617	=item $handle->rbuf_max ($max_octets)
		618
		619	Configures the C<rbuf_max> setting (C<undef> disables it).
		620
		621	=cut
		622
		623	sub rbuf_max {
		624	$_[0]{rbuf_max} = $_[1];
		625	}
		626
		627	#############################################################################
		628
		629	=item $handle->timeout ($seconds)
		630
		631	=item $handle->rtimeout ($seconds)
		632
		633	=item $handle->wtimeout ($seconds)
		634
		635	Configures (or disables) the inactivity timeout.
		636
		637	=item $handle->timeout_reset
		638
		639	=item $handle->rtimeout_reset
		640
		641	=item $handle->wtimeout_reset
		642
		643	Reset the activity timeout, as if data was received or sent.
		644
		645	These methods are cheap to call.
		646
		647	=cut
		648
		649	for my $dir ("", "r", "w") {
		650	my $timeout = "${dir}timeout";
		651	my $tw = "_${dir}tw";
		652	my $on_timeout = "on_${dir}timeout";
		653	my $activity = "_${dir}activity";
		654	my $cb;
		655
		656	*$on_timeout = sub {
		657	$_[0]{$on_timeout} = $_[1];
		658	};
		659
		660	*$timeout = sub {
		661	my ($self, $new_value) = @_;
		662
		663	$self->{$timeout} = $new_value;
		664	delete $self->{$tw}; &$cb;
		665	};
		666
		667	*{"${dir}timeout_reset"} = sub {
		668	$_[0]{$activity} = AE::now;
		669	};
		670
		671	# main workhorse:
		672	# reset the timeout watcher, as neccessary
		673	# also check for time-outs
		674	$cb = sub {
		675	my ($self) = @_;
		676
		677	if ($self->{$timeout} && $self->{fh}) {
		678	my $NOW = AE::now;
		679
		680	# when would the timeout trigger?
		681	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		682
		683	# now or in the past already?
		684	if ($after <= 0) {
		685	$self->{$activity} = $NOW;
		686
		687	if ($self->{$on_timeout}) {
		688	$self->{$on_timeout}($self);
		689	} else {
		690	$self->_error (Errno::ETIMEDOUT);
		691	}
		692
		693	# callback could have changed timeout value, optimise
		694	return unless $self->{$timeout};
		695
		696	# calculate new after
		697	$after = $self->{$timeout};
		698	}
		699
		700	Scalar::Util::weaken $self;
		701	return unless $self; # ->error could have destroyed $self
		702
		703	$self->{$tw} ||= AE::timer $after, 0, sub {
		704	delete $self->{$tw};
		705	$cb->($self);
36	chomp;	706	};
37	print "Line: $_";	707	} else {
		708	delete $self->{$tw};
		709	}
		710	}
		711	}
		712
		713	#############################################################################
		714
		715	=back
		716
		717	=head2 WRITE QUEUE
		718
		719	AnyEvent::Handle manages two queues per handle, one for writing and one
		720	for reading.
		721
		722	The write queue is very simple: you can add data to its end, and
		723	AnyEvent::Handle will automatically try to get rid of it for you.
		724
		725	When data could be written and the write buffer is shorter then the low
		726	water mark, the C<on_drain> callback will be invoked.
		727
		728	=over 4
		729
		730	=item $handle->on_drain ($cb)
		731
		732	Sets the C<on_drain> callback or clears it (see the description of
		733	C<on_drain> in the constructor).
		734
		735	=cut
		736
		737	sub on_drain {
		738	my ($self, $cb) = @_;
		739
		740	$self->{on_drain} = $cb;
		741
		742	$cb->($self)
		743	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		744	}
		745
		746	=item $handle->push_write ($data)
		747
		748	Queues the given scalar to be written. You can push as much data as you
		749	want (only limited by the available memory), as C<AnyEvent::Handle>
		750	buffers it independently of the kernel.
		751
		752	=cut
		753
		754	sub _drain_wbuf {
		755	my ($self) = @_;
		756
		757	if (!$self->{_ww} && length $self->{wbuf}) {
		758
		759	Scalar::Util::weaken $self;
		760
		761	my $cb = sub {
		762	my $len = syswrite $self->{fh}, $self->{wbuf};
		763
		764	if (defined $len) {
		765	substr $self->{wbuf}, 0, $len, "";
		766
		767	$self->{_activity} = $self->{_wactivity} = AE::now;
		768
		769	$self->{on_drain}($self)
		770	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		771	&& $self->{on_drain};
		772
		773	delete $self->{_ww} unless length $self->{wbuf};
		774	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		775	$self->_error ($!, 1);
		776	}
		777	};
		778
		779	# try to write data immediately
		780	$cb->() unless $self->{autocork};
		781
		782	# if still data left in wbuf, we need to poll
		783	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		784	if length $self->{wbuf};
		785	};
		786	}
		787
		788	our %WH;
		789
		790	sub register_write_type($$) {
		791	$WH{$_[0]} = $_[1];
		792	}
		793
		794	sub push_write {
		795	my $self = shift;
		796
		797	if (@_ > 1) {
		798	my $type = shift;
		799
		800	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		801	->($self, @_);
		802	}
		803
		804	if ($self->{tls}) {
		805	$self->{_tls_wbuf} .= $_[0];
		806	&_dotls ($self) if $self->{fh};
		807	} else {
		808	$self->{wbuf} .= $_[0];
		809	$self->_drain_wbuf if $self->{fh};
		810	}
		811	}
		812
		813	=item $handle->push_write (type => @args)
		814
		815	Instead of formatting your data yourself, you can also let this module do
		816	the job by specifying a type and type-specific arguments.
		817
		818	Predefined types are (if you have ideas for additional types, feel free to
		819	drop by and tell us):
		820
		821	=over 4
		822
		823	=item netstring => $string
		824
		825	Formats the given value as netstring
		826	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		827
		828	=cut
		829
		830	register_write_type netstring => sub {
		831	my ($self, $string) = @_;
		832
		833	(length $string) . ":$string,"
		834	};
		835
		836	=item packstring => $format, $data
		837
		838	An octet string prefixed with an encoded length. The encoding C<$format>
		839	uses the same format as a Perl C<pack> format, but must specify a single
		840	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		841	optional C<!>, C<< < >> or C<< > >> modifier).
		842
		843	=cut
		844
		845	register_write_type packstring => sub {
		846	my ($self, $format, $string) = @_;
		847
		848	pack "$format/a*", $string
		849	};
		850
		851	=item json => $array_or_hashref
		852
		853	Encodes the given hash or array reference into a JSON object. Unless you
		854	provide your own JSON object, this means it will be encoded to JSON text
		855	in UTF-8.
		856
		857	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		858	one end of a handle and read them at the other end without using any
		859	additional framing.
		860
		861	The generated JSON text is guaranteed not to contain any newlines: While
		862	this module doesn't need delimiters after or between JSON texts to be
		863	able to read them, many other languages depend on that.
		864
		865	A simple RPC protocol that interoperates easily with others is to send
		866	JSON arrays (or objects, although arrays are usually the better choice as
		867	they mimic how function argument passing works) and a newline after each
		868	JSON text:
		869
		870	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		871	$handle->push_write ("\012");
		872
		873	An AnyEvent::Handle receiver would simply use the C<json> read type and
		874	rely on the fact that the newline will be skipped as leading whitespace:
		875
		876	$handle->push_read (json => sub { my $array = $_[1]; ... });
		877
		878	Other languages could read single lines terminated by a newline and pass
		879	this line into their JSON decoder of choice.
		880
		881	=cut
		882
		883	sub json_coder() {
		884	eval { require JSON::XS; JSON::XS->new->utf8 }
		885	|| do { require JSON; JSON->new->utf8 }
		886	}
		887
		888	register_write_type json => sub {
		889	my ($self, $ref) = @_;
		890
		891	my $json = $self->{json} ||= json_coder;
		892
		893	$json->encode ($ref)
		894	};
		895
		896	=item storable => $reference
		897
		898	Freezes the given reference using L<Storable> and writes it to the
		899	handle. Uses the C<nfreeze> format.
		900
		901	=cut
		902
		903	register_write_type storable => sub {
		904	my ($self, $ref) = @_;
		905
		906	require Storable;
		907
		908	pack "w/a*", Storable::nfreeze ($ref)
		909	};
		910
		911	=back
		912
		913	=item $handle->push_shutdown
		914
		915	Sometimes you know you want to close the socket after writing your data
		916	before it was actually written. One way to do that is to replace your
		917	C<on_drain> handler by a callback that shuts down the socket (and set
		918	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		919	replaces the C<on_drain> callback with:
		920
		921	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		922
		923	This simply shuts down the write side and signals an EOF condition to the
		924	the peer.
		925
		926	You can rely on the normal read queue and C<on_eof> handling
		927	afterwards. This is the cleanest way to close a connection.
		928
		929	=cut
		930
		931	sub push_shutdown {
		932	my ($self) = @_;
		933
		934	delete $self->{low_water_mark};
		935	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		936	}
		937
		938	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		939
		940	This function (not method) lets you add your own types to C<push_write>.
		941	Whenever the given C<type> is used, C<push_write> will invoke the code
		942	reference with the handle object and the remaining arguments.
		943
		944	The code reference is supposed to return a single octet string that will
		945	be appended to the write buffer.
		946
		947	Note that this is a function, and all types registered this way will be
		948	global, so try to use unique names.
		949
		950	=cut
		951
		952	#############################################################################
		953
		954	=back
		955
		956	=head2 READ QUEUE
		957
		958	AnyEvent::Handle manages two queues per handle, one for writing and one
		959	for reading.
		960
		961	The read queue is more complex than the write queue. It can be used in two
		962	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		963	a queue.
		964
		965	In the simple case, you just install an C<on_read> callback and whenever
		966	new data arrives, it will be called. You can then remove some data (if
		967	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		968	leave the data there if you want to accumulate more (e.g. when only a
		969	partial message has been received so far).
		970
		971	In the more complex case, you want to queue multiple callbacks. In this
		972	case, AnyEvent::Handle will call the first queued callback each time new
		973	data arrives (also the first time it is queued) and removes it when it has
		974	done its job (see C<push_read>, below).
		975
		976	This way you can, for example, push three line-reads, followed by reading
		977	a chunk of data, and AnyEvent::Handle will execute them in order.
		978
		979	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		980	the specified number of bytes which give an XML datagram.
		981
		982	# in the default state, expect some header bytes
		983	$handle->on_read (sub {
		984	# some data is here, now queue the length-header-read (4 octets)
		985	shift->unshift_read (chunk => 4, sub {
		986	# header arrived, decode
		987	my $len = unpack "N", $_[1];
		988
		989	# now read the payload
		990	shift->unshift_read (chunk => $len, sub {
		991	my $xml = $_[1];
		992	# handle xml
		993	});
		994	});
		995	});
		996
		997	Example 2: Implement a client for a protocol that replies either with "OK"
		998	and another line or "ERROR" for the first request that is sent, and 64
		999	bytes for the second request. Due to the availability of a queue, we can
		1000	just pipeline sending both requests and manipulate the queue as necessary
		1001	in the callbacks.
		1002
		1003	When the first callback is called and sees an "OK" response, it will
		1004	C<unshift> another line-read. This line-read will be queued I<before> the
		1005	64-byte chunk callback.
		1006
		1007	# request one, returns either "OK + extra line" or "ERROR"
		1008	$handle->push_write ("request 1\015\012");
		1009
		1010	# we expect "ERROR" or "OK" as response, so push a line read
		1011	$handle->push_read (line => sub {
		1012	# if we got an "OK", we have to _prepend_ another line,
		1013	# so it will be read before the second request reads its 64 bytes
		1014	# which are already in the queue when this callback is called
		1015	# we don't do this in case we got an error
		1016	if ($_[1] eq "OK") {
		1017	$_[0]->unshift_read (line => sub {
		1018	my $response = $_[1];
		1019	...
		1020	});
38	}	1021	}
39	});	1022	});
40		1023
41	# or use the constructor to pass the callback:	1024	# request two, simply returns 64 octets
		1025	$handle->push_write ("request 2\015\012");
42		1026
43	my $ae_fh2 =	1027	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1028	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1029	my $response = $_[1];
46	on_eof => sub {	1030	...
47	$cv->broadcast;	1031	});
48	},	1032
49	on_readline => sub {	1033	=over 4
50	my ($ae_fh, @lines) = @_;	1034
51	for (@lines) {	1035	=cut
52	chomp;	1036
53	print "Line: $_";	1037	sub _drain_rbuf {
		1038	my ($self) = @_;
		1039
		1040	# avoid recursion
		1041	return if $self->{_skip_drain_rbuf};
		1042	local $self->{_skip_drain_rbuf} = 1;
		1043
		1044	while () {
		1045	# we need to use a separate tls read buffer, as we must not receive data while
		1046	# we are draining the buffer, and this can only happen with TLS.
		1047	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1048	if exists $self->{_tls_rbuf};
		1049
		1050	my $len = length $self->{rbuf};
		1051
		1052	if (my $cb = shift @{ $self->{_queue} }) {
		1053	unless ($cb->($self)) {
		1054	# no progress can be made
		1055	# (not enough data and no data forthcoming)
		1056	$self->_error (Errno::EPIPE, 1), return
		1057	if $self->{_eof};
		1058
		1059	unshift @{ $self->{_queue} }, $cb;
54	}	1060	last;
55	}	1061	}
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}) {	1062	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1063	last unless $len;
122		1064
		1065	$self->{on_read}($self);
		1066
		1067	if (
		1068	$len == length $self->{rbuf} # if no data has been consumed
		1069	&& !@{ $self->{_queue} } # and the queue is still empty
		1070	&& $self->{on_read} # but we still have on_read
		1071	) {
		1072	# no further data will arrive
		1073	# so no progress can be made
		1074	$self->_error (Errno::EPIPE, 1), return
		1075	if $self->{_eof};
		1076
		1077	last; # more data might arrive
		1078	}
		1079	} else {
		1080	# read side becomes idle
		1081	delete $self->{_rw} unless $self->{tls};
		1082	last;
		1083	}
		1084	}
		1085
123	} elsif ($self->{on_eof}) {	1086	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1087	$self->{on_eof}
		1088	? $self->{on_eof}($self)
		1089	: $self->_error (0, 1, "Unexpected end-of-file");
125		1090
126	} elsif ($self->{on_error}) {	1091	return;
127	$self->on_eof ($self->{on_error});
128	}	1092	}
129		1093
130	return $self	1094	if (
131	}	1095	defined $self->{rbuf_max}
		1096	&& $self->{rbuf_max} < length $self->{rbuf}
		1097	) {
		1098	$self->_error (Errno::ENOSPC, 1), return;
		1099	}
132		1100
133	=item B<fh>	1101	# may need to restart read watcher
		1102	unless ($self->{_rw}) {
		1103	$self->start_read
		1104	if $self->{on_read} || @{ $self->{_queue} };
		1105	}
		1106	}
134		1107
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1108	=item $handle->on_read ($cb)
136		1109
137	=cut	1110	This replaces the currently set C<on_read> callback, or clears it (when
138		1111	the new callback is C<undef>). See the description of C<on_read> in the
139	sub fh { $_[0]->{fh} }	1112	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		1113
149	=cut	1114	=cut
150		1115
151	sub on_read {	1116	sub on_read {
152	my ($self, $cb) = @_;	1117	my ($self, $cb) = @_;
		1118
153	$self->{on_read} = $cb;	1119	$self->{on_read} = $cb;
		1120	$self->_drain_rbuf if $cb;
		1121	}
154		1122
155	unless (defined $self->{on_read}) {	1123	=item $handle->rbuf
156	delete $self->{on_read_w};	1124
		1125	Returns the read buffer (as a modifiable lvalue).
		1126
		1127	You can access the read buffer directly as the C<< ->{rbuf} >>
		1128	member, if you want. However, the only operation allowed on the
		1129	read buffer (apart from looking at it) is removing data from its
		1130	beginning. Otherwise modifying or appending to it is not allowed and will
		1131	lead to hard-to-track-down bugs.
		1132
		1133	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1134	C<push_read> or C<unshift_read> methods are used. The other read methods
		1135	automatically manage the read buffer.
		1136
		1137	=cut
		1138
		1139	sub rbuf : lvalue {
		1140	$_[0]{rbuf}
		1141	}
		1142
		1143	=item $handle->push_read ($cb)
		1144
		1145	=item $handle->unshift_read ($cb)
		1146
		1147	Append the given callback to the end of the queue (C<push_read>) or
		1148	prepend it (C<unshift_read>).
		1149
		1150	The callback is called each time some additional read data arrives.
		1151
		1152	It must check whether enough data is in the read buffer already.
		1153
		1154	If not enough data is available, it must return the empty list or a false
		1155	value, in which case it will be called repeatedly until enough data is
		1156	available (or an error condition is detected).
		1157
		1158	If enough data was available, then the callback must remove all data it is
		1159	interested in (which can be none at all) and return a true value. After returning
		1160	true, it will be removed from the queue.
		1161
		1162	=cut
		1163
		1164	our %RH;
		1165
		1166	sub register_read_type($$) {
		1167	$RH{$_[0]} = $_[1];
		1168	}
		1169
		1170	sub push_read {
		1171	my $self = shift;
		1172	my $cb = pop;
		1173
		1174	if (@_) {
		1175	my $type = shift;
		1176
		1177	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		1178	->($self, $cb, @_);
		1179	}
		1180
		1181	push @{ $self->{_queue} }, $cb;
		1182	$self->_drain_rbuf;
		1183	}
		1184
		1185	sub unshift_read {
		1186	my $self = shift;
		1187	my $cb = pop;
		1188
		1189	if (@_) {
		1190	my $type = shift;
		1191
		1192	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1193	->($self, $cb, @_);
		1194	}
		1195
		1196
		1197	unshift @{ $self->{_queue} }, $cb;
		1198	$self->_drain_rbuf;
		1199	}
		1200
		1201	=item $handle->push_read (type => @args, $cb)
		1202
		1203	=item $handle->unshift_read (type => @args, $cb)
		1204
		1205	Instead of providing a callback that parses the data itself you can chose
		1206	between a number of predefined parsing formats, for chunks of data, lines
		1207	etc.
		1208
		1209	Predefined types are (if you have ideas for additional types, feel free to
		1210	drop by and tell us):
		1211
		1212	=over 4
		1213
		1214	=item chunk => $octets, $cb->($handle, $data)
		1215
		1216	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1217	data read to the callback. The callback will never be called with less
		1218	data.
		1219
		1220	Example: read 2 bytes.
		1221
		1222	$handle->push_read (chunk => 2, sub {
		1223	warn "yay ", unpack "H*", $_[1];
		1224	});
		1225
		1226	=cut
		1227
		1228	register_read_type chunk => sub {
		1229	my ($self, $cb, $len) = @_;
		1230
		1231	sub {
		1232	$len <= length $_[0]{rbuf} or return;
		1233	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1234	1
		1235	}
		1236	};
		1237
		1238	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1239
		1240	The callback will be called only once a full line (including the end of
		1241	line marker, C<$eol>) has been read. This line (excluding the end of line
		1242	marker) will be passed to the callback as second argument (C<$line>), and
		1243	the end of line marker as the third argument (C<$eol>).
		1244
		1245	The end of line marker, C<$eol>, can be either a string, in which case it
		1246	will be interpreted as a fixed record end marker, or it can be a regex
		1247	object (e.g. created by C<qr>), in which case it is interpreted as a
		1248	regular expression.
		1249
		1250	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1251	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1252	protocols).
		1253
		1254	Partial lines at the end of the stream will never be returned, as they are
		1255	not marked by the end of line marker.
		1256
		1257	=cut
		1258
		1259	register_read_type line => sub {
		1260	my ($self, $cb, $eol) = @_;
		1261
		1262	if (@_ < 3) {
		1263	# this is more than twice as fast as the generic code below
		1264	sub {
		1265	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1266
		1267	$cb->($_[0], $1, $2);
		1268	1
		1269	}
		1270	} else {
		1271	$eol = quotemeta $eol unless ref $eol;
		1272	$eol = qr|^(.*?)($eol)|s;
		1273
		1274	sub {
		1275	$_[0]{rbuf} =~ s/$eol// or return;
		1276
		1277	$cb->($_[0], $1, $2);
		1278	1
		1279	}
		1280	}
		1281	};
		1282
		1283	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1284
		1285	Makes a regex match against the regex object C<$accept> and returns
		1286	everything up to and including the match.
		1287
		1288	Example: read a single line terminated by '\n'.
		1289
		1290	$handle->push_read (regex => qr<\n>, sub { ... });
		1291
		1292	If C<$reject> is given and not undef, then it determines when the data is
		1293	to be rejected: it is matched against the data when the C<$accept> regex
		1294	does not match and generates an C<EBADMSG> error when it matches. This is
		1295	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1296	receive buffer overflow).
		1297
		1298	Example: expect a single decimal number followed by whitespace, reject
		1299	anything else (not the use of an anchor).
		1300
		1301	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1302
		1303	If C<$skip> is given and not C<undef>, then it will be matched against
		1304	the receive buffer when neither C<$accept> nor C<$reject> match,
		1305	and everything preceding and including the match will be accepted
		1306	unconditionally. This is useful to skip large amounts of data that you
		1307	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1308	have to start matching from the beginning. This is purely an optimisation
		1309	and is usually worth only when you expect more than a few kilobytes.
		1310
		1311	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1312	expect the header to be very large (it isn't in practise, but...), we use
		1313	a skip regex to skip initial portions. The skip regex is tricky in that
		1314	it only accepts something not ending in either \015 or \012, as these are
		1315	required for the accept regex.
		1316
		1317	$handle->push_read (regex =>
		1318	qr<\015\012\015\012>,
		1319	undef, # no reject
		1320	qr<^.*[^\015\012]>,
		1321	sub { ... });
		1322
		1323	=cut
		1324
		1325	register_read_type regex => sub {
		1326	my ($self, $cb, $accept, $reject, $skip) = @_;
		1327
		1328	my $data;
		1329	my $rbuf = \$self->{rbuf};
		1330
		1331	sub {
		1332	# accept
		1333	if ($$rbuf =~ $accept) {
		1334	$data .= substr $$rbuf, 0, $+[0], "";
		1335	$cb->($self, $data);
		1336	return 1;
		1337	}
		1338
		1339	# reject
		1340	if ($reject && $$rbuf =~ $reject) {
		1341	$self->_error (Errno::EBADMSG);
		1342	}
		1343
		1344	# skip
		1345	if ($skip && $$rbuf =~ $skip) {
		1346	$data .= substr $$rbuf, 0, $+[0], "";
		1347	}
		1348
		1349	()
		1350	}
		1351	};
		1352
		1353	=item netstring => $cb->($handle, $string)
		1354
		1355	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1356
		1357	Throws an error with C<$!> set to EBADMSG on format violations.
		1358
		1359	=cut
		1360
		1361	register_read_type netstring => sub {
		1362	my ($self, $cb) = @_;
		1363
		1364	sub {
		1365	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1366	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1367	$self->_error (Errno::EBADMSG);
		1368	}
157	return;	1369	return;
		1370	}
		1371
		1372	my $len = $1;
		1373
		1374	$self->unshift_read (chunk => $len, sub {
		1375	my $string = $_[1];
		1376	$_[0]->unshift_read (chunk => 1, sub {
		1377	if ($_[1] eq ",") {
		1378	$cb->($_[0], $string);
		1379	} else {
		1380	$self->_error (Errno::EBADMSG);
		1381	}
		1382	});
		1383	});
		1384
		1385	1
		1386	}
		1387	};
		1388
		1389	=item packstring => $format, $cb->($handle, $string)
		1390
		1391	An octet string prefixed with an encoded length. The encoding C<$format>
		1392	uses the same format as a Perl C<pack> format, but must specify a single
		1393	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1394	optional C<!>, C<< < >> or C<< > >> modifier).
		1395
		1396	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1397	EPP uses a prefix of C<N> (4 octtes).
		1398
		1399	Example: read a block of data prefixed by its length in BER-encoded
		1400	format (very efficient).
		1401
		1402	$handle->push_read (packstring => "w", sub {
		1403	my ($handle, $data) = @_;
158	}	1404	});
159		1405
160	$self->{on_read_w} =	1406	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1407
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1408	register_read_type packstring => sub {
		1409	my ($self, $cb, $format) = @_;
		1410
		1411	sub {
		1412	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1413	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1414	or return;
		1415
		1416	$format = length pack $format, $len;
		1417
		1418	# bypass unshift if we already have the remaining chunk
		1419	if ($format + $len <= length $_[0]{rbuf}) {
		1420	my $data = substr $_[0]{rbuf}, $format, $len;
		1421	substr $_[0]{rbuf}, 0, $format + $len, "";
		1422	$cb->($_[0], $data);
		1423	} else {
		1424	# remove prefix
		1425	substr $_[0]{rbuf}, 0, $format, "";
		1426
		1427	# read remaining chunk
		1428	$_[0]->unshift_read (chunk => $len, $cb);
		1429	}
		1430
		1431	1
		1432	}
		1433	};
		1434
		1435	=item json => $cb->($handle, $hash_or_arrayref)
		1436
		1437	Reads a JSON object or array, decodes it and passes it to the
		1438	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1439
		1440	If a C<json> object was passed to the constructor, then that will be used
		1441	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1442
		1443	This read type uses the incremental parser available with JSON version
		1444	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1445	dependency on your own: this module will load the JSON module, but
		1446	AnyEvent does not depend on it itself.
		1447
		1448	Since JSON texts are fully self-delimiting, the C<json> read and write
		1449	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1450	the C<json> write type description, above, for an actual example.
		1451
		1452	=cut
		1453
		1454	register_read_type json => sub {
		1455	my ($self, $cb) = @_;
		1456
		1457	my $json = $self->{json} ||= json_coder;
		1458
		1459	my $data;
163	my $rbuf_len = length $self->{rbuf};	1460	my $rbuf = \$self->{rbuf};
164	my $l;	1461
165	if (defined $self->{read_size}) {	1462	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1463	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1464
		1465	if ($ref) {
		1466	$self->{rbuf} = $json->incr_text;
		1467	$json->incr_text = "";
		1468	$cb->($self, $ref);
		1469
		1470	1
		1471	} elsif ($@) {
		1472	# error case
		1473	$json->incr_skip;
		1474
		1475	$self->{rbuf} = $json->incr_text;
		1476	$json->incr_text = "";
		1477
		1478	$self->_error (Errno::EBADMSG);
		1479
		1480	()
		1481	} else {
		1482	$self->{rbuf} = "";
		1483
		1484	()
		1485	}
		1486	}
		1487	};
		1488
		1489	=item storable => $cb->($handle, $ref)
		1490
		1491	Deserialises a L<Storable> frozen representation as written by the
		1492	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1493	data).
		1494
		1495	Raises C<EBADMSG> error if the data could not be decoded.
		1496
		1497	=cut
		1498
		1499	register_read_type storable => sub {
		1500	my ($self, $cb) = @_;
		1501
		1502	require Storable;
		1503
		1504	sub {
		1505	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1506	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1507	or return;
		1508
		1509	my $format = length pack "w", $len;
		1510
		1511	# bypass unshift if we already have the remaining chunk
		1512	if ($format + $len <= length $_[0]{rbuf}) {
		1513	my $data = substr $_[0]{rbuf}, $format, $len;
		1514	substr $_[0]{rbuf}, 0, $format + $len, "";
		1515	$cb->($_[0], Storable::thaw ($data));
		1516	} else {
		1517	# remove prefix
		1518	substr $_[0]{rbuf}, 0, $format, "";
		1519
		1520	# read remaining chunk
		1521	$_[0]->unshift_read (chunk => $len, sub {
		1522	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1523	$cb->($_[0], $ref);
		1524	} else {
		1525	$self->_error (Errno::EBADMSG);
		1526	}
		1527	});
		1528	}
		1529
		1530	1
		1531	}
		1532	};
		1533
		1534	=back
		1535
		1536	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1537
		1538	This function (not method) lets you add your own types to C<push_read>.
		1539
		1540	Whenever the given C<type> is used, C<push_read> will invoke the code
		1541	reference with the handle object, the callback and the remaining
		1542	arguments.
		1543
		1544	The code reference is supposed to return a callback (usually a closure)
		1545	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1546
		1547	It should invoke the passed callback when it is done reading (remember to
		1548	pass C<$handle> as first argument as all other callbacks do that).
		1549
		1550	Note that this is a function, and all types registered this way will be
		1551	global, so try to use unique names.
		1552
		1553	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1554	search for C<register_read_type>)).
		1555
		1556	=item $handle->stop_read
		1557
		1558	=item $handle->start_read
		1559
		1560	In rare cases you actually do not want to read anything from the
		1561	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1562	any queued callbacks will be executed then. To start reading again, call
		1563	C<start_read>.
		1564
		1565	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1566	you change the C<on_read> callback or push/unshift a read callback, and it
		1567	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1568	there are any read requests in the queue.
		1569
		1570	These methods will have no effect when in TLS mode (as TLS doesn't support
		1571	half-duplex connections).
		1572
		1573	=cut
		1574
		1575	sub stop_read {
		1576	my ($self) = @_;
		1577
		1578	delete $self->{_rw} unless $self->{tls};
		1579	}
		1580
		1581	sub start_read {
		1582	my ($self) = @_;
		1583
		1584	unless ($self->{_rw} || $self->{_eof}) {
		1585	Scalar::Util::weaken $self;
		1586
		1587	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1588	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1589	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1590
		1591	if ($len > 0) {
		1592	$self->{_activity} = $self->{_ractivity} = AE::now;
		1593
		1594	if ($self->{tls}) {
		1595	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1596
		1597	&_dotls ($self);
		1598	} else {
		1599	$self->_drain_rbuf;
		1600	}
		1601
		1602	} elsif (defined $len) {
		1603	delete $self->{_rw};
		1604	$self->{_eof} = 1;
		1605	$self->_drain_rbuf;
		1606
		1607	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1608	return $self->_error ($!, 1);
		1609	}
		1610	};
		1611	}
		1612	}
		1613
		1614	our $ERROR_SYSCALL;
		1615	our $ERROR_WANT_READ;
		1616
		1617	sub _tls_error {
		1618	my ($self, $err) = @_;
		1619
		1620	return $self->_error ($!, 1)
		1621	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1622
		1623	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1624
		1625	# reduce error string to look less scary
		1626	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1627
		1628	if ($self->{_on_starttls}) {
		1629	(delete $self->{_on_starttls})->($self, undef, $err);
		1630	&_freetls;
		1631	} else {
		1632	&_freetls;
		1633	$self->_error (Errno::EPROTO, 1, $err);
		1634	}
		1635	}
		1636
		1637	# poll the write BIO and send the data if applicable
		1638	# also decode read data if possible
		1639	# this is basiclaly our TLS state machine
		1640	# more efficient implementations are possible with openssl,
		1641	# but not with the buggy and incomplete Net::SSLeay.
		1642	sub _dotls {
		1643	my ($self) = @_;
		1644
		1645	my $tmp;
		1646
		1647	if (length $self->{_tls_wbuf}) {
		1648	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1649	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1650	}
		1651
		1652	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1653	return $self->_tls_error ($tmp)
		1654	if $tmp != $ERROR_WANT_READ
		1655	&& ($tmp != $ERROR_SYSCALL || $!);
		1656	}
		1657
		1658	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1659	unless (length $tmp) {
		1660	$self->{_on_starttls}
		1661	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1662	&_freetls;
		1663
		1664	if ($self->{on_stoptls}) {
		1665	$self->{on_stoptls}($self);
		1666	return;
168	} else {	1667	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1668	# 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};	1669	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];	1670	$self->{_eof} = 1;
316	}	1671	}
317	}	1672	}
318	return;	1673
		1674	$self->{_tls_rbuf} .= $tmp;
		1675	$self->_drain_rbuf;
		1676	$self->{tls} or return; # tls session might have gone away in callback
		1677	}
		1678
		1679	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1680	return $self->_tls_error ($tmp)
		1681	if $tmp != $ERROR_WANT_READ
		1682	&& ($tmp != $ERROR_SYSCALL || $!);
		1683
		1684	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1685	$self->{wbuf} .= $tmp;
		1686	$self->_drain_wbuf;
		1687	}
		1688
		1689	$self->{_on_starttls}
		1690	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1691	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1692	}
		1693
		1694	=item $handle->starttls ($tls[, $tls_ctx])
		1695
		1696	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1697	object is created, you can also do that at a later time by calling
		1698	C<starttls>.
		1699
		1700	Starting TLS is currently an asynchronous operation - when you push some
		1701	write data and then call C<< ->starttls >> then TLS negotiation will start
		1702	immediately, after which the queued write data is then sent.
		1703
		1704	The first argument is the same as the C<tls> constructor argument (either
		1705	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1706
		1707	The second argument is the optional C<AnyEvent::TLS> object that is used
		1708	when AnyEvent::Handle has to create its own TLS connection object, or
		1709	a hash reference with C<< key => value >> pairs that will be used to
		1710	construct a new context.
		1711
		1712	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1713	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1714	changed to your liking. Note that the handshake might have already started
		1715	when this function returns.
		1716
		1717	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1718	handshakes on the same stream. Best do not attempt to use the stream after
		1719	stopping TLS.
		1720
		1721	=cut
		1722
		1723	our %TLS_CACHE; #TODO not yet documented, should we?
		1724
		1725	sub starttls {
		1726	my ($self, $tls, $ctx) = @_;
		1727
		1728	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1729	if $self->{tls};
		1730
		1731	$self->{tls} = $tls;
		1732	$self->{tls_ctx} = $ctx if @_ > 2;
		1733
		1734	return unless $self->{fh};
		1735
		1736	require Net::SSLeay;
		1737
		1738	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1739	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1740
		1741	$tls = $self->{tls};
		1742	$ctx = $self->{tls_ctx};
		1743
		1744	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1745
		1746	if ("HASH" eq ref $ctx) {
		1747	require AnyEvent::TLS;
		1748
		1749	if ($ctx->{cache}) {
		1750	my $key = $ctx+0;
		1751	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1752	} else {
		1753	$ctx = new AnyEvent::TLS %$ctx;
		1754	}
		1755	}
319	}	1756
		1757	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1758	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
320		1759
321	my $wba = shift @{$self->{write_bufs}}	1760	# basically, this is deep magic (because SSL_read should have the same issues)
322	or return;	1761	# but the openssl maintainers basically said: "trust us, it just works".
		1762	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1763	# and mismaintained ssleay-module doesn't even offer them).
		1764	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1765	#
		1766	# in short: this is a mess.
		1767	#
		1768	# note that we do not try to keep the length constant between writes as we are required to do.
		1769	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1770	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1771	# have identity issues in that area.
		1772	# Net::SSLeay::CTX_set_mode ($ssl,
		1773	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1774	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1775	Net::SSLeay::CTX_set_mode ($tls, 1|2);
323		1776
324	unless (defined $wba->[0]) {	1777	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
325	$wba->[1]->($self) if $wba->[1];	1778	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
326	$self->_check_writer;	1779
327	return;	1780	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1781
		1782	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1783
		1784	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1785	if $self->{on_starttls};
		1786
		1787	&_dotls; # need to trigger the initial handshake
		1788	$self->start_read; # make sure we actually do read
		1789	}
		1790
		1791	=item $handle->stoptls
		1792
		1793	Shuts down the SSL connection - this makes a proper EOF handshake by
		1794	sending a close notify to the other side, but since OpenSSL doesn't
		1795	support non-blocking shut downs, it is not guarenteed that you can re-use
		1796	the stream afterwards.
		1797
		1798	=cut
		1799
		1800	sub stoptls {
		1801	my ($self) = @_;
		1802
		1803	if ($self->{tls}) {
		1804	Net::SSLeay::shutdown ($self->{tls});
		1805
		1806	&_dotls;
		1807
		1808	# # we don't give a shit. no, we do, but we can't. no...#d#
		1809	# # we, we... have to use openssl :/#d#
		1810	# &_freetls;#d#
		1811	}
		1812	}
		1813
		1814	sub _freetls {
		1815	my ($self) = @_;
		1816
		1817	return unless $self->{tls};
		1818
		1819	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1820	if $self->{tls} > 0;
328	}	1821
		1822	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1823	}
329		1824
330	$self->{wbuf} = $wba->[0];	1825	sub DESTROY {
331	$self->{write_cb} = $wba->[1];	1826	my ($self) = @_;
332		1827
333	$self->{write_w} =	1828	&_freetls;
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1829
		1830	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1831
		1832	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1833	my $fh = delete $self->{fh};
		1834	my $wbuf = delete $self->{wbuf};
		1835
		1836	my @linger;
		1837
		1838	push @linger, AE::io $fh, 1, sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1839	my $len = syswrite $fh, $wbuf, length $wbuf;
336		1840
337	if (not defined $l) {	1841	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	1842	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	1843	} else {
343	substr $self->{wbuf}, 0, $l, '';	1844	@linger = (); # end
344
345	if (length ($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	}	1845	}
355	});	1846	};
		1847	push @linger, AE::timer $linger, 0, sub {
		1848	@linger = ();
		1849	};
		1850	}
		1851	}
		1852
		1853	=item $handle->destroy
		1854
		1855	Shuts down the handle object as much as possible - this call ensures that
		1856	no further callbacks will be invoked and as many resources as possible
		1857	will be freed. Any method you will call on the handle object after
		1858	destroying it in this way will be silently ignored (and it will return the
		1859	empty list).
		1860
		1861	Normally, you can just "forget" any references to an AnyEvent::Handle
		1862	object and it will simply shut down. This works in fatal error and EOF
		1863	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1864	callback, so when you want to destroy the AnyEvent::Handle object from
		1865	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1866	that case.
		1867
		1868	Destroying the handle object in this way has the advantage that callbacks
		1869	will be removed as well, so if those are the only reference holders (as
		1870	is common), then one doesn't need to do anything special to break any
		1871	reference cycles.
		1872
		1873	The handle might still linger in the background and write out remaining
		1874	data, as specified by the C<linger> option, however.
		1875
		1876	=cut
		1877
		1878	sub destroy {
		1879	my ($self) = @_;
		1880
		1881	$self->DESTROY;
		1882	%$self = ();
		1883	bless $self, "AnyEvent::Handle::destroyed";
		1884	}
		1885
		1886	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		1887	#nop
		1888	}
		1889
		1890	=item AnyEvent::Handle::TLS_CTX
		1891
		1892	This function creates and returns the AnyEvent::TLS object used by default
		1893	for TLS mode.
		1894
		1895	The context is created by calling L<AnyEvent::TLS> without any arguments.
		1896
		1897	=cut
		1898
		1899	our $TLS_CTX;
		1900
		1901	sub TLS_CTX() {
		1902	$TLS_CTX ||= do {
		1903	require AnyEvent::TLS;
		1904
		1905	new AnyEvent::TLS
		1906	}
356	}	1907	}
357		1908
358	=back	1909	=back
359		1910
		1911
		1912	=head1 NONFREQUENTLY ASKED QUESTIONS
		1913
		1914	=over 4
		1915
		1916	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1917	still get further invocations!
		1918
		1919	That's because AnyEvent::Handle keeps a reference to itself when handling
		1920	read or write callbacks.
		1921
		1922	It is only safe to "forget" the reference inside EOF or error callbacks,
		1923	from within all other callbacks, you need to explicitly call the C<<
		1924	->destroy >> method.
		1925
		1926	=item I get different callback invocations in TLS mode/Why can't I pause
		1927	reading?
		1928
		1929	Unlike, say, TCP, TLS connections do not consist of two independent
		1930	communication channels, one for each direction. Or put differently. The
		1931	read and write directions are not independent of each other: you cannot
		1932	write data unless you are also prepared to read, and vice versa.
		1933
		1934	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1935	callback invocations when you are not expecting any read data - the reason
		1936	is that AnyEvent::Handle always reads in TLS mode.
		1937
		1938	During the connection, you have to make sure that you always have a
		1939	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1940	connection (or when you no longer want to use it) you can call the
		1941	C<destroy> method.
		1942
		1943	=item How do I read data until the other side closes the connection?
		1944
		1945	If you just want to read your data into a perl scalar, the easiest way
		1946	to achieve this is by setting an C<on_read> callback that does nothing,
		1947	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1948	will be in C<$_[0]{rbuf}>:
		1949
		1950	$handle->on_read (sub { });
		1951	$handle->on_eof (undef);
		1952	$handle->on_error (sub {
		1953	my $data = delete $_[0]{rbuf};
		1954	});
		1955
		1956	The reason to use C<on_error> is that TCP connections, due to latencies
		1957	and packets loss, might get closed quite violently with an error, when in
		1958	fact, all data has been received.
		1959
		1960	It is usually better to use acknowledgements when transferring data,
		1961	to make sure the other side hasn't just died and you got the data
		1962	intact. This is also one reason why so many internet protocols have an
		1963	explicit QUIT command.
		1964
		1965	=item I don't want to destroy the handle too early - how do I wait until
		1966	all data has been written?
		1967
		1968	After writing your last bits of data, set the C<on_drain> callback
		1969	and destroy the handle in there - with the default setting of
		1970	C<low_water_mark> this will be called precisely when all data has been
		1971	written to the socket:
		1972
		1973	$handle->push_write (...);
		1974	$handle->on_drain (sub {
		1975	warn "all data submitted to the kernel\n";
		1976	undef $handle;
		1977	});
		1978
		1979	If you just want to queue some data and then signal EOF to the other side,
		1980	consider using C<< ->push_shutdown >> instead.
		1981
		1982	=item I want to contact a TLS/SSL server, I don't care about security.
		1983
		1984	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		1985	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		1986	parameter:
		1987
		1988	tcp_connect $host, $port, sub {
		1989	my ($fh) = @_;
		1990
		1991	my $handle = new AnyEvent::Handle
		1992	fh => $fh,
		1993	tls => "connect",
		1994	on_error => sub { ... };
		1995
		1996	$handle->push_write (...);
		1997	};
		1998
		1999	=item I want to contact a TLS/SSL server, I do care about security.
		2000
		2001	Then you should additionally enable certificate verification, including
		2002	peername verification, if the protocol you use supports it (see
		2003	L<AnyEvent::TLS>, C<verify_peername>).
		2004
		2005	E.g. for HTTPS:
		2006
		2007	tcp_connect $host, $port, sub {
		2008	my ($fh) = @_;
		2009
		2010	my $handle = new AnyEvent::Handle
		2011	fh => $fh,
		2012	peername => $host,
		2013	tls => "connect",
		2014	tls_ctx => { verify => 1, verify_peername => "https" },
		2015	...
		2016
		2017	Note that you must specify the hostname you connected to (or whatever
		2018	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2019	peername verification will be done.
		2020
		2021	The above will use the system-dependent default set of trusted CA
		2022	certificates. If you want to check against a specific CA, add the
		2023	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2024
		2025	tls_ctx => {
		2026	verify => 1,
		2027	verify_peername => "https",
		2028	ca_file => "my-ca-cert.pem",
		2029	},
		2030
		2031	=item I want to create a TLS/SSL server, how do I do that?
		2032
		2033	Well, you first need to get a server certificate and key. You have
		2034	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2035	self-signed certificate (cheap. check the search engine of your choice,
		2036	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2037	nice program for that purpose).
		2038
		2039	Then create a file with your private key (in PEM format, see
		2040	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2041	file should then look like this:
		2042
		2043	-----BEGIN RSA PRIVATE KEY-----
		2044	...header data
		2045	... lots of base64'y-stuff
		2046	-----END RSA PRIVATE KEY-----
		2047
		2048	-----BEGIN CERTIFICATE-----
		2049	... lots of base64'y-stuff
		2050	-----END CERTIFICATE-----
		2051
		2052	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2053	specify this file as C<cert_file>:
		2054
		2055	tcp_server undef, $port, sub {
		2056	my ($fh) = @_;
		2057
		2058	my $handle = new AnyEvent::Handle
		2059	fh => $fh,
		2060	tls => "accept",
		2061	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2062	...
		2063
		2064	When you have intermediate CA certificates that your clients might not
		2065	know about, just append them to the C<cert_file>.
		2066
		2067	=back
		2068
		2069
		2070	=head1 SUBCLASSING AnyEvent::Handle
		2071
		2072	In many cases, you might want to subclass AnyEvent::Handle.
		2073
		2074	To make this easier, a given version of AnyEvent::Handle uses these
		2075	conventions:
		2076
		2077	=over 4
		2078
		2079	=item * all constructor arguments become object members.
		2080
		2081	At least initially, when you pass a C<tls>-argument to the constructor it
		2082	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2083	mutated later on (for example C<tls> will hold the TLS connection object).
		2084
		2085	=item * other object member names are prefixed with an C<_>.
		2086
		2087	All object members not explicitly documented (internal use) are prefixed
		2088	with an underscore character, so the remaining non-C<_>-namespace is free
		2089	for use for subclasses.
		2090
		2091	=item * all members not documented here and not prefixed with an underscore
		2092	are free to use in subclasses.
		2093
		2094	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2095	member variables, but thats just life, at least it is documented.
		2096
		2097	=back
		2098
360	=head1 AUTHOR	2099	=head1 AUTHOR
361		2100
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	2101	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363		2102
364	=cut	2103	=cut
365		2104
366	1; # End of AnyEvent::Handle	2105	1; # End of AnyEvent::Handle

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