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Revision 1.5 by elmex, Mon Apr 28 08:01:05 2008 UTC vs.
Revision 1.177 by root, Sun Aug 9 00:24:35 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
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 _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	$self->_drain_wbuf;
		510	}
		511
		512	#sub _shutdown {
		513	# my ($self) = @_;
		514	#
		515	# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
		516	# $self->{_eof} = 1; # tell starttls et. al to stop trying
		517	#
		518	# &_freetls;
		519	#}
		520
		521	sub _error {
		522	my ($self, $errno, $fatal, $message) = @_;
		523
		524	$! = $errno;
		525	$message ||= "$!";
		526
		527	if ($self->{on_error}) {
		528	$self->{on_error}($self, $fatal, $message);
		529	$self->destroy if $fatal;
		530	} elsif ($self->{fh}) {
		531	$self->destroy;
		532	Carp::croak "AnyEvent::Handle uncaught error: $message";
		533	}
		534	}
		535
		536	=item $fh = $handle->fh
		537
		538	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		539
		540	=cut
		541
		542	sub fh { $_[0]{fh} }
		543
		544	=item $handle->on_error ($cb)
		545
		546	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		547
		548	=cut
		549
		550	sub on_error {
		551	$_[0]{on_error} = $_[1];
		552	}
		553
		554	=item $handle->on_eof ($cb)
		555
		556	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		557
		558	=cut
		559
		560	sub on_eof {
		561	$_[0]{on_eof} = $_[1];
		562	}
		563
		564	=item $handle->on_timeout ($cb)
		565
		566	=item $handle->on_rtimeout ($cb)
		567
		568	=item $handle->on_wtimeout ($cb)
		569
		570	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		571	callback, or disables the callback (but not the timeout) if C<$cb> =
		572	C<undef>. See the C<timeout> constructor argument and method.
		573
		574	=cut
		575
		576	# see below
		577
		578	=item $handle->autocork ($boolean)
		579
		580	Enables or disables the current autocork behaviour (see C<autocork>
		581	constructor argument). Changes will only take effect on the next write.
		582
		583	=cut
		584
		585	sub autocork {
		586	$_[0]{autocork} = $_[1];
		587	}
		588
		589	=item $handle->no_delay ($boolean)
		590
		591	Enables or disables the C<no_delay> setting (see constructor argument of
		592	the same name for details).
		593
		594	=cut
		595
		596	sub no_delay {
		597	$_[0]{no_delay} = $_[1];
		598
		599	eval {
		600	local $SIG{__DIE__};
		601	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]
		602	if $_[0]{fh};
		603	};
		604	}
		605
		606	=item $handle->on_starttls ($cb)
		607
		608	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		609
		610	=cut
		611
		612	sub on_starttls {
		613	$_[0]{on_starttls} = $_[1];
		614	}
		615
		616	=item $handle->on_stoptls ($cb)
		617
		618	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		619
		620	=cut
		621
		622	sub on_starttls {
		623	$_[0]{on_stoptls} = $_[1];
		624	}
		625
		626	=item $handle->rbuf_max ($max_octets)
		627
		628	Configures the C<rbuf_max> setting (C<undef> disables it).
		629
		630	=cut
		631
		632	sub rbuf_max {
		633	$_[0]{rbuf_max} = $_[1];
		634	}
		635
		636	#############################################################################
		637
		638	=item $handle->timeout ($seconds)
		639
		640	=item $handle->rtimeout ($seconds)
		641
		642	=item $handle->wtimeout ($seconds)
		643
		644	Configures (or disables) the inactivity timeout.
		645
		646	=item $handle->timeout_reset
		647
		648	=item $handle->rtimeout_reset
		649
		650	=item $handle->wtimeout_reset
		651
		652	Reset the activity timeout, as if data was received or sent.
		653
		654	These methods are cheap to call.
		655
		656	=cut
		657
		658	for my $dir ("", "r", "w") {
		659	my $timeout = "${dir}timeout";
		660	my $tw = "_${dir}tw";
		661	my $on_timeout = "on_${dir}timeout";
		662	my $activity = "_${dir}activity";
		663	my $cb;
		664
		665	*$on_timeout = sub {
		666	$_[0]{$on_timeout} = $_[1];
		667	};
		668
		669	*$timeout = sub {
		670	my ($self, $new_value) = @_;
		671
		672	$self->{$timeout} = $new_value;
		673	delete $self->{$tw}; &$cb;
		674	};
		675
		676	*{"${dir}timeout_reset"} = sub {
		677	$_[0]{$activity} = AE::now;
		678	};
		679
		680	# main workhorse:
		681	# reset the timeout watcher, as neccessary
		682	# also check for time-outs
		683	$cb = sub {
		684	my ($self) = @_;
		685
		686	if ($self->{$timeout} && $self->{fh}) {
		687	my $NOW = AE::now;
		688
		689	# when would the timeout trigger?
		690	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		691
		692	# now or in the past already?
		693	if ($after <= 0) {
		694	$self->{$activity} = $NOW;
		695
		696	if ($self->{$on_timeout}) {
		697	$self->{$on_timeout}($self);
		698	} else {
		699	$self->_error (Errno::ETIMEDOUT);
		700	}
		701
		702	# callback could have changed timeout value, optimise
		703	return unless $self->{$timeout};
		704
		705	# calculate new after
		706	$after = $self->{$timeout};
		707	}
		708
		709	Scalar::Util::weaken $self;
		710	return unless $self; # ->error could have destroyed $self
		711
		712	$self->{$tw} ||= AE::timer $after, 0, sub {
		713	delete $self->{$tw};
		714	$cb->($self);
36	chomp;	715	};
37	print "Line: $_";	716	} else {
		717	delete $self->{$tw};
		718	}
		719	}
		720	}
		721
		722	#############################################################################
		723
		724	=back
		725
		726	=head2 WRITE QUEUE
		727
		728	AnyEvent::Handle manages two queues per handle, one for writing and one
		729	for reading.
		730
		731	The write queue is very simple: you can add data to its end, and
		732	AnyEvent::Handle will automatically try to get rid of it for you.
		733
		734	When data could be written and the write buffer is shorter then the low
		735	water mark, the C<on_drain> callback will be invoked.
		736
		737	=over 4
		738
		739	=item $handle->on_drain ($cb)
		740
		741	Sets the C<on_drain> callback or clears it (see the description of
		742	C<on_drain> in the constructor).
		743
		744	=cut
		745
		746	sub on_drain {
		747	my ($self, $cb) = @_;
		748
		749	$self->{on_drain} = $cb;
		750
		751	$cb->($self)
		752	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		753	}
		754
		755	=item $handle->push_write ($data)
		756
		757	Queues the given scalar to be written. You can push as much data as you
		758	want (only limited by the available memory), as C<AnyEvent::Handle>
		759	buffers it independently of the kernel.
		760
		761	=cut
		762
		763	sub _drain_wbuf {
		764	my ($self) = @_;
		765
		766	if (!$self->{_ww} && length $self->{wbuf}) {
		767
		768	Scalar::Util::weaken $self;
		769
		770	my $cb = sub {
		771	my $len = syswrite $self->{fh}, $self->{wbuf};
		772
		773	if (defined $len) {
		774	substr $self->{wbuf}, 0, $len, "";
		775
		776	$self->{_activity} = $self->{_wactivity} = AE::now;
		777
		778	$self->{on_drain}($self)
		779	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		780	&& $self->{on_drain};
		781
		782	delete $self->{_ww} unless length $self->{wbuf};
		783	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		784	$self->_error ($!, 1);
		785	}
		786	};
		787
		788	# try to write data immediately
		789	$cb->() unless $self->{autocork};
		790
		791	# if still data left in wbuf, we need to poll
		792	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		793	if length $self->{wbuf};
		794	};
		795	}
		796
		797	our %WH;
		798
		799	sub register_write_type($$) {
		800	$WH{$_[0]} = $_[1];
		801	}
		802
		803	sub push_write {
		804	my $self = shift;
		805
		806	if (@_ > 1) {
		807	my $type = shift;
		808
		809	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		810	->($self, @_);
		811	}
		812
		813	if ($self->{tls}) {
		814	$self->{_tls_wbuf} .= $_[0];
		815	&_dotls ($self) if $self->{fh};
		816	} else {
		817	$self->{wbuf} .= $_[0];
		818	$self->_drain_wbuf if $self->{fh};
		819	}
		820	}
		821
		822	=item $handle->push_write (type => @args)
		823
		824	Instead of formatting your data yourself, you can also let this module do
		825	the job by specifying a type and type-specific arguments.
		826
		827	Predefined types are (if you have ideas for additional types, feel free to
		828	drop by and tell us):
		829
		830	=over 4
		831
		832	=item netstring => $string
		833
		834	Formats the given value as netstring
		835	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		836
		837	=cut
		838
		839	register_write_type netstring => sub {
		840	my ($self, $string) = @_;
		841
		842	(length $string) . ":$string,"
		843	};
		844
		845	=item packstring => $format, $data
		846
		847	An octet string prefixed with an encoded length. The encoding C<$format>
		848	uses the same format as a Perl C<pack> format, but must specify a single
		849	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		850	optional C<!>, C<< < >> or C<< > >> modifier).
		851
		852	=cut
		853
		854	register_write_type packstring => sub {
		855	my ($self, $format, $string) = @_;
		856
		857	pack "$format/a*", $string
		858	};
		859
		860	=item json => $array_or_hashref
		861
		862	Encodes the given hash or array reference into a JSON object. Unless you
		863	provide your own JSON object, this means it will be encoded to JSON text
		864	in UTF-8.
		865
		866	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		867	one end of a handle and read them at the other end without using any
		868	additional framing.
		869
		870	The generated JSON text is guaranteed not to contain any newlines: While
		871	this module doesn't need delimiters after or between JSON texts to be
		872	able to read them, many other languages depend on that.
		873
		874	A simple RPC protocol that interoperates easily with others is to send
		875	JSON arrays (or objects, although arrays are usually the better choice as
		876	they mimic how function argument passing works) and a newline after each
		877	JSON text:
		878
		879	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		880	$handle->push_write ("\012");
		881
		882	An AnyEvent::Handle receiver would simply use the C<json> read type and
		883	rely on the fact that the newline will be skipped as leading whitespace:
		884
		885	$handle->push_read (json => sub { my $array = $_[1]; ... });
		886
		887	Other languages could read single lines terminated by a newline and pass
		888	this line into their JSON decoder of choice.
		889
		890	=cut
		891
		892	register_write_type json => sub {
		893	my ($self, $ref) = @_;
		894
		895	require JSON;
		896
		897	$self->{json} ? $self->{json}->encode ($ref)
		898	: JSON::encode_json ($ref)
		899	};
		900
		901	=item storable => $reference
		902
		903	Freezes the given reference using L<Storable> and writes it to the
		904	handle. Uses the C<nfreeze> format.
		905
		906	=cut
		907
		908	register_write_type storable => sub {
		909	my ($self, $ref) = @_;
		910
		911	require Storable;
		912
		913	pack "w/a*", Storable::nfreeze ($ref)
		914	};
		915
		916	=back
		917
		918	=item $handle->push_shutdown
		919
		920	Sometimes you know you want to close the socket after writing your data
		921	before it was actually written. One way to do that is to replace your
		922	C<on_drain> handler by a callback that shuts down the socket (and set
		923	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		924	replaces the C<on_drain> callback with:
		925
		926	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		927
		928	This simply shuts down the write side and signals an EOF condition to the
		929	the peer.
		930
		931	You can rely on the normal read queue and C<on_eof> handling
		932	afterwards. This is the cleanest way to close a connection.
		933
		934	=cut
		935
		936	sub push_shutdown {
		937	my ($self) = @_;
		938
		939	delete $self->{low_water_mark};
		940	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		941	}
		942
		943	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		944
		945	This function (not method) lets you add your own types to C<push_write>.
		946	Whenever the given C<type> is used, C<push_write> will invoke the code
		947	reference with the handle object and the remaining arguments.
		948
		949	The code reference is supposed to return a single octet string that will
		950	be appended to the write buffer.
		951
		952	Note that this is a function, and all types registered this way will be
		953	global, so try to use unique names.
		954
		955	=cut
		956
		957	#############################################################################
		958
		959	=back
		960
		961	=head2 READ QUEUE
		962
		963	AnyEvent::Handle manages two queues per handle, one for writing and one
		964	for reading.
		965
		966	The read queue is more complex than the write queue. It can be used in two
		967	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		968	a queue.
		969
		970	In the simple case, you just install an C<on_read> callback and whenever
		971	new data arrives, it will be called. You can then remove some data (if
		972	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		973	leave the data there if you want to accumulate more (e.g. when only a
		974	partial message has been received so far).
		975
		976	In the more complex case, you want to queue multiple callbacks. In this
		977	case, AnyEvent::Handle will call the first queued callback each time new
		978	data arrives (also the first time it is queued) and removes it when it has
		979	done its job (see C<push_read>, below).
		980
		981	This way you can, for example, push three line-reads, followed by reading
		982	a chunk of data, and AnyEvent::Handle will execute them in order.
		983
		984	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		985	the specified number of bytes which give an XML datagram.
		986
		987	# in the default state, expect some header bytes
		988	$handle->on_read (sub {
		989	# some data is here, now queue the length-header-read (4 octets)
		990	shift->unshift_read (chunk => 4, sub {
		991	# header arrived, decode
		992	my $len = unpack "N", $_[1];
		993
		994	# now read the payload
		995	shift->unshift_read (chunk => $len, sub {
		996	my $xml = $_[1];
		997	# handle xml
		998	});
		999	});
		1000	});
		1001
		1002	Example 2: Implement a client for a protocol that replies either with "OK"
		1003	and another line or "ERROR" for the first request that is sent, and 64
		1004	bytes for the second request. Due to the availability of a queue, we can
		1005	just pipeline sending both requests and manipulate the queue as necessary
		1006	in the callbacks.
		1007
		1008	When the first callback is called and sees an "OK" response, it will
		1009	C<unshift> another line-read. This line-read will be queued I<before> the
		1010	64-byte chunk callback.
		1011
		1012	# request one, returns either "OK + extra line" or "ERROR"
		1013	$handle->push_write ("request 1\015\012");
		1014
		1015	# we expect "ERROR" or "OK" as response, so push a line read
		1016	$handle->push_read (line => sub {
		1017	# if we got an "OK", we have to _prepend_ another line,
		1018	# so it will be read before the second request reads its 64 bytes
		1019	# which are already in the queue when this callback is called
		1020	# we don't do this in case we got an error
		1021	if ($_[1] eq "OK") {
		1022	$_[0]->unshift_read (line => sub {
		1023	my $response = $_[1];
		1024	...
		1025	});
38	}	1026	}
39	});	1027	});
40		1028
41	# or use the constructor to pass the callback:	1029	# request two, simply returns 64 octets
		1030	$handle->push_write ("request 2\015\012");
42		1031
43	my $ae_fh2 =	1032	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1033	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1034	my $response = $_[1];
46	on_eof => sub {	1035	...
47	$cv->broadcast;	1036	});
48	},	1037
49	on_readline => sub {	1038	=over 4
50	my ($ae_fh, @lines) = @_;	1039
51	for (@lines) {	1040	=cut
52	chomp;	1041
53	print "Line: $_";	1042	sub _drain_rbuf {
		1043	my ($self) = @_;
		1044
		1045	# avoid recursion
		1046	return if $self->{_skip_drain_rbuf};
		1047	local $self->{_skip_drain_rbuf} = 1;
		1048
		1049	while () {
		1050	# we need to use a separate tls read buffer, as we must not receive data while
		1051	# we are draining the buffer, and this can only happen with TLS.
		1052	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1053	if exists $self->{_tls_rbuf};
		1054
		1055	my $len = length $self->{rbuf};
		1056
		1057	if (my $cb = shift @{ $self->{_queue} }) {
		1058	unless ($cb->($self)) {
		1059	# no progress can be made
		1060	# (not enough data and no data forthcoming)
		1061	$self->_error (Errno::EPIPE, 1), return
		1062	if $self->{_eof};
		1063
		1064	unshift @{ $self->{_queue} }, $cb;
54	}	1065	last;
55	}	1066	}
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}) {	1067	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1068	last unless $len;
122		1069
		1070	$self->{on_read}($self);
		1071
		1072	if (
		1073	$len == length $self->{rbuf} # if no data has been consumed
		1074	&& !@{ $self->{_queue} } # and the queue is still empty
		1075	&& $self->{on_read} # but we still have on_read
		1076	) {
		1077	# no further data will arrive
		1078	# so no progress can be made
		1079	$self->_error (Errno::EPIPE, 1), return
		1080	if $self->{_eof};
		1081
		1082	last; # more data might arrive
		1083	}
		1084	} else {
		1085	# read side becomes idle
		1086	delete $self->{_rw} unless $self->{tls};
		1087	last;
		1088	}
		1089	}
		1090
123	} elsif ($self->{on_eof}) {	1091	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1092	$self->{on_eof}
		1093	? $self->{on_eof}($self)
		1094	: $self->_error (0, 1, "Unexpected end-of-file");
125		1095
126	} elsif ($self->{on_error}) {	1096	return;
127	$self->on_eof ($self->{on_error});
128	}	1097	}
129		1098
130	return $self	1099	if (
131	}	1100	defined $self->{rbuf_max}
		1101	&& $self->{rbuf_max} < length $self->{rbuf}
		1102	) {
		1103	$self->_error (Errno::ENOSPC, 1), return;
		1104	}
132		1105
133	=item B<fh>	1106	# may need to restart read watcher
		1107	unless ($self->{_rw}) {
		1108	$self->start_read
		1109	if $self->{on_read} || @{ $self->{_queue} };
		1110	}
		1111	}
134		1112
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1113	=item $handle->on_read ($cb)
136		1114
137	=cut	1115	This replaces the currently set C<on_read> callback, or clears it (when
138		1116	the new callback is C<undef>). See the description of C<on_read> in the
139	sub fh { $_[0]->{fh} }	1117	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		1118
149	=cut	1119	=cut
150		1120
151	sub on_read {	1121	sub on_read {
152	my ($self, $cb) = @_;	1122	my ($self, $cb) = @_;
		1123
153	$self->{on_read} = $cb;	1124	$self->{on_read} = $cb;
		1125	$self->_drain_rbuf if $cb;
		1126	}
154		1127
155	unless (defined $self->{on_read}) {	1128	=item $handle->rbuf
156	delete $self->{on_read_w};	1129
		1130	Returns the read buffer (as a modifiable lvalue).
		1131
		1132	You can access the read buffer directly as the C<< ->{rbuf} >>
		1133	member, if you want. However, the only operation allowed on the
		1134	read buffer (apart from looking at it) is removing data from its
		1135	beginning. Otherwise modifying or appending to it is not allowed and will
		1136	lead to hard-to-track-down bugs.
		1137
		1138	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1139	C<push_read> or C<unshift_read> methods are used. The other read methods
		1140	automatically manage the read buffer.
		1141
		1142	=cut
		1143
		1144	sub rbuf : lvalue {
		1145	$_[0]{rbuf}
		1146	}
		1147
		1148	=item $handle->push_read ($cb)
		1149
		1150	=item $handle->unshift_read ($cb)
		1151
		1152	Append the given callback to the end of the queue (C<push_read>) or
		1153	prepend it (C<unshift_read>).
		1154
		1155	The callback is called each time some additional read data arrives.
		1156
		1157	It must check whether enough data is in the read buffer already.
		1158
		1159	If not enough data is available, it must return the empty list or a false
		1160	value, in which case it will be called repeatedly until enough data is
		1161	available (or an error condition is detected).
		1162
		1163	If enough data was available, then the callback must remove all data it is
		1164	interested in (which can be none at all) and return a true value. After returning
		1165	true, it will be removed from the queue.
		1166
		1167	=cut
		1168
		1169	our %RH;
		1170
		1171	sub register_read_type($$) {
		1172	$RH{$_[0]} = $_[1];
		1173	}
		1174
		1175	sub push_read {
		1176	my $self = shift;
		1177	my $cb = pop;
		1178
		1179	if (@_) {
		1180	my $type = shift;
		1181
		1182	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		1183	->($self, $cb, @_);
		1184	}
		1185
		1186	push @{ $self->{_queue} }, $cb;
		1187	$self->_drain_rbuf;
		1188	}
		1189
		1190	sub unshift_read {
		1191	my $self = shift;
		1192	my $cb = pop;
		1193
		1194	if (@_) {
		1195	my $type = shift;
		1196
		1197	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1198	->($self, $cb, @_);
		1199	}
		1200
		1201
		1202	unshift @{ $self->{_queue} }, $cb;
		1203	$self->_drain_rbuf;
		1204	}
		1205
		1206	=item $handle->push_read (type => @args, $cb)
		1207
		1208	=item $handle->unshift_read (type => @args, $cb)
		1209
		1210	Instead of providing a callback that parses the data itself you can chose
		1211	between a number of predefined parsing formats, for chunks of data, lines
		1212	etc.
		1213
		1214	Predefined types are (if you have ideas for additional types, feel free to
		1215	drop by and tell us):
		1216
		1217	=over 4
		1218
		1219	=item chunk => $octets, $cb->($handle, $data)
		1220
		1221	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1222	data read to the callback. The callback will never be called with less
		1223	data.
		1224
		1225	Example: read 2 bytes.
		1226
		1227	$handle->push_read (chunk => 2, sub {
		1228	warn "yay ", unpack "H*", $_[1];
		1229	});
		1230
		1231	=cut
		1232
		1233	register_read_type chunk => sub {
		1234	my ($self, $cb, $len) = @_;
		1235
		1236	sub {
		1237	$len <= length $_[0]{rbuf} or return;
		1238	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1239	1
		1240	}
		1241	};
		1242
		1243	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1244
		1245	The callback will be called only once a full line (including the end of
		1246	line marker, C<$eol>) has been read. This line (excluding the end of line
		1247	marker) will be passed to the callback as second argument (C<$line>), and
		1248	the end of line marker as the third argument (C<$eol>).
		1249
		1250	The end of line marker, C<$eol>, can be either a string, in which case it
		1251	will be interpreted as a fixed record end marker, or it can be a regex
		1252	object (e.g. created by C<qr>), in which case it is interpreted as a
		1253	regular expression.
		1254
		1255	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1256	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1257	protocols).
		1258
		1259	Partial lines at the end of the stream will never be returned, as they are
		1260	not marked by the end of line marker.
		1261
		1262	=cut
		1263
		1264	register_read_type line => sub {
		1265	my ($self, $cb, $eol) = @_;
		1266
		1267	if (@_ < 3) {
		1268	# this is more than twice as fast as the generic code below
		1269	sub {
		1270	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1271
		1272	$cb->($_[0], $1, $2);
		1273	1
		1274	}
		1275	} else {
		1276	$eol = quotemeta $eol unless ref $eol;
		1277	$eol = qr|^(.*?)($eol)|s;
		1278
		1279	sub {
		1280	$_[0]{rbuf} =~ s/$eol// or return;
		1281
		1282	$cb->($_[0], $1, $2);
		1283	1
		1284	}
		1285	}
		1286	};
		1287
		1288	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1289
		1290	Makes a regex match against the regex object C<$accept> and returns
		1291	everything up to and including the match.
		1292
		1293	Example: read a single line terminated by '\n'.
		1294
		1295	$handle->push_read (regex => qr<\n>, sub { ... });
		1296
		1297	If C<$reject> is given and not undef, then it determines when the data is
		1298	to be rejected: it is matched against the data when the C<$accept> regex
		1299	does not match and generates an C<EBADMSG> error when it matches. This is
		1300	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1301	receive buffer overflow).
		1302
		1303	Example: expect a single decimal number followed by whitespace, reject
		1304	anything else (not the use of an anchor).
		1305
		1306	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1307
		1308	If C<$skip> is given and not C<undef>, then it will be matched against
		1309	the receive buffer when neither C<$accept> nor C<$reject> match,
		1310	and everything preceding and including the match will be accepted
		1311	unconditionally. This is useful to skip large amounts of data that you
		1312	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1313	have to start matching from the beginning. This is purely an optimisation
		1314	and is usually worth only when you expect more than a few kilobytes.
		1315
		1316	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1317	expect the header to be very large (it isn't in practise, but...), we use
		1318	a skip regex to skip initial portions. The skip regex is tricky in that
		1319	it only accepts something not ending in either \015 or \012, as these are
		1320	required for the accept regex.
		1321
		1322	$handle->push_read (regex =>
		1323	qr<\015\012\015\012>,
		1324	undef, # no reject
		1325	qr<^.*[^\015\012]>,
		1326	sub { ... });
		1327
		1328	=cut
		1329
		1330	register_read_type regex => sub {
		1331	my ($self, $cb, $accept, $reject, $skip) = @_;
		1332
		1333	my $data;
		1334	my $rbuf = \$self->{rbuf};
		1335
		1336	sub {
		1337	# accept
		1338	if ($$rbuf =~ $accept) {
		1339	$data .= substr $$rbuf, 0, $+[0], "";
		1340	$cb->($self, $data);
		1341	return 1;
		1342	}
		1343
		1344	# reject
		1345	if ($reject && $$rbuf =~ $reject) {
		1346	$self->_error (Errno::EBADMSG);
		1347	}
		1348
		1349	# skip
		1350	if ($skip && $$rbuf =~ $skip) {
		1351	$data .= substr $$rbuf, 0, $+[0], "";
		1352	}
		1353
		1354	()
		1355	}
		1356	};
		1357
		1358	=item netstring => $cb->($handle, $string)
		1359
		1360	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1361
		1362	Throws an error with C<$!> set to EBADMSG on format violations.
		1363
		1364	=cut
		1365
		1366	register_read_type netstring => sub {
		1367	my ($self, $cb) = @_;
		1368
		1369	sub {
		1370	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1371	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1372	$self->_error (Errno::EBADMSG);
		1373	}
157	return;	1374	return;
		1375	}
		1376
		1377	my $len = $1;
		1378
		1379	$self->unshift_read (chunk => $len, sub {
		1380	my $string = $_[1];
		1381	$_[0]->unshift_read (chunk => 1, sub {
		1382	if ($_[1] eq ",") {
		1383	$cb->($_[0], $string);
		1384	} else {
		1385	$self->_error (Errno::EBADMSG);
		1386	}
		1387	});
		1388	});
		1389
		1390	1
		1391	}
		1392	};
		1393
		1394	=item packstring => $format, $cb->($handle, $string)
		1395
		1396	An octet string prefixed with an encoded length. The encoding C<$format>
		1397	uses the same format as a Perl C<pack> format, but must specify a single
		1398	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1399	optional C<!>, C<< < >> or C<< > >> modifier).
		1400
		1401	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1402	EPP uses a prefix of C<N> (4 octtes).
		1403
		1404	Example: read a block of data prefixed by its length in BER-encoded
		1405	format (very efficient).
		1406
		1407	$handle->push_read (packstring => "w", sub {
		1408	my ($handle, $data) = @_;
158	}	1409	});
159		1410
160	$self->{on_read_w} =	1411	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1412
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1413	register_read_type packstring => sub {
		1414	my ($self, $cb, $format) = @_;
		1415
		1416	sub {
		1417	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1418	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1419	or return;
		1420
		1421	$format = length pack $format, $len;
		1422
		1423	# bypass unshift if we already have the remaining chunk
		1424	if ($format + $len <= length $_[0]{rbuf}) {
		1425	my $data = substr $_[0]{rbuf}, $format, $len;
		1426	substr $_[0]{rbuf}, 0, $format + $len, "";
		1427	$cb->($_[0], $data);
		1428	} else {
		1429	# remove prefix
		1430	substr $_[0]{rbuf}, 0, $format, "";
		1431
		1432	# read remaining chunk
		1433	$_[0]->unshift_read (chunk => $len, $cb);
		1434	}
		1435
		1436	1
		1437	}
		1438	};
		1439
		1440	=item json => $cb->($handle, $hash_or_arrayref)
		1441
		1442	Reads a JSON object or array, decodes it and passes it to the
		1443	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1444
		1445	If a C<json> object was passed to the constructor, then that will be used
		1446	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1447
		1448	This read type uses the incremental parser available with JSON version
		1449	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1450	dependency on your own: this module will load the JSON module, but
		1451	AnyEvent does not depend on it itself.
		1452
		1453	Since JSON texts are fully self-delimiting, the C<json> read and write
		1454	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1455	the C<json> write type description, above, for an actual example.
		1456
		1457	=cut
		1458
		1459	register_read_type json => sub {
		1460	my ($self, $cb) = @_;
		1461
		1462	my $json = $self->{json} ||=
		1463	eval { require JSON::XS; JSON::XS->new->utf8 }
		1464	|| do { require JSON; JSON->new->utf8 };
		1465
		1466	my $data;
163	my $rbuf_len = length $self->{rbuf};	1467	my $rbuf = \$self->{rbuf};
164	my $l;	1468
165	if (defined $self->{read_size}) {	1469	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1470	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1471
		1472	if ($ref) {
		1473	$self->{rbuf} = $json->incr_text;
		1474	$json->incr_text = "";
		1475	$cb->($self, $ref);
		1476
		1477	1
		1478	} elsif ($@) {
		1479	# error case
		1480	$json->incr_skip;
		1481
		1482	$self->{rbuf} = $json->incr_text;
		1483	$json->incr_text = "";
		1484
		1485	$self->_error (Errno::EBADMSG);
		1486
		1487	()
		1488	} else {
		1489	$self->{rbuf} = "";
		1490
		1491	()
		1492	}
		1493	}
		1494	};
		1495
		1496	=item storable => $cb->($handle, $ref)
		1497
		1498	Deserialises a L<Storable> frozen representation as written by the
		1499	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1500	data).
		1501
		1502	Raises C<EBADMSG> error if the data could not be decoded.
		1503
		1504	=cut
		1505
		1506	register_read_type storable => sub {
		1507	my ($self, $cb) = @_;
		1508
		1509	require Storable;
		1510
		1511	sub {
		1512	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1513	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1514	or return;
		1515
		1516	my $format = length pack "w", $len;
		1517
		1518	# bypass unshift if we already have the remaining chunk
		1519	if ($format + $len <= length $_[0]{rbuf}) {
		1520	my $data = substr $_[0]{rbuf}, $format, $len;
		1521	substr $_[0]{rbuf}, 0, $format + $len, "";
		1522	$cb->($_[0], Storable::thaw ($data));
		1523	} else {
		1524	# remove prefix
		1525	substr $_[0]{rbuf}, 0, $format, "";
		1526
		1527	# read remaining chunk
		1528	$_[0]->unshift_read (chunk => $len, sub {
		1529	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1530	$cb->($_[0], $ref);
		1531	} else {
		1532	$self->_error (Errno::EBADMSG);
		1533	}
		1534	});
		1535	}
		1536
		1537	1
		1538	}
		1539	};
		1540
		1541	=back
		1542
		1543	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1544
		1545	This function (not method) lets you add your own types to C<push_read>.
		1546
		1547	Whenever the given C<type> is used, C<push_read> will invoke the code
		1548	reference with the handle object, the callback and the remaining
		1549	arguments.
		1550
		1551	The code reference is supposed to return a callback (usually a closure)
		1552	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1553
		1554	It should invoke the passed callback when it is done reading (remember to
		1555	pass C<$handle> as first argument as all other callbacks do that).
		1556
		1557	Note that this is a function, and all types registered this way will be
		1558	global, so try to use unique names.
		1559
		1560	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1561	search for C<register_read_type>)).
		1562
		1563	=item $handle->stop_read
		1564
		1565	=item $handle->start_read
		1566
		1567	In rare cases you actually do not want to read anything from the
		1568	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1569	any queued callbacks will be executed then. To start reading again, call
		1570	C<start_read>.
		1571
		1572	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1573	you change the C<on_read> callback or push/unshift a read callback, and it
		1574	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1575	there are any read requests in the queue.
		1576
		1577	These methods will have no effect when in TLS mode (as TLS doesn't support
		1578	half-duplex connections).
		1579
		1580	=cut
		1581
		1582	sub stop_read {
		1583	my ($self) = @_;
		1584
		1585	delete $self->{_rw} unless $self->{tls};
		1586	}
		1587
		1588	sub start_read {
		1589	my ($self) = @_;
		1590
		1591	unless ($self->{_rw} || $self->{_eof}) {
		1592	Scalar::Util::weaken $self;
		1593
		1594	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1595	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1596	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1597
		1598	if ($len > 0) {
		1599	$self->{_activity} = $self->{_ractivity} = AE::now;
		1600
		1601	if ($self->{tls}) {
		1602	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1603
		1604	&_dotls ($self);
		1605	} else {
		1606	$self->_drain_rbuf;
		1607	}
		1608
		1609	} elsif (defined $len) {
		1610	delete $self->{_rw};
		1611	$self->{_eof} = 1;
		1612	$self->_drain_rbuf;
		1613
		1614	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1615	return $self->_error ($!, 1);
		1616	}
		1617	};
		1618	}
		1619	}
		1620
		1621	our $ERROR_SYSCALL;
		1622	our $ERROR_WANT_READ;
		1623
		1624	sub _tls_error {
		1625	my ($self, $err) = @_;
		1626
		1627	return $self->_error ($!, 1)
		1628	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1629
		1630	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1631
		1632	# reduce error string to look less scary
		1633	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1634
		1635	if ($self->{_on_starttls}) {
		1636	(delete $self->{_on_starttls})->($self, undef, $err);
		1637	&_freetls;
		1638	} else {
		1639	&_freetls;
		1640	$self->_error (Errno::EPROTO, 1, $err);
		1641	}
		1642	}
		1643
		1644	# poll the write BIO and send the data if applicable
		1645	# also decode read data if possible
		1646	# this is basiclaly our TLS state machine
		1647	# more efficient implementations are possible with openssl,
		1648	# but not with the buggy and incomplete Net::SSLeay.
		1649	sub _dotls {
		1650	my ($self) = @_;
		1651
		1652	my $tmp;
		1653
		1654	if (length $self->{_tls_wbuf}) {
		1655	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1656	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1657	}
		1658
		1659	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1660	return $self->_tls_error ($tmp)
		1661	if $tmp != $ERROR_WANT_READ
		1662	&& ($tmp != $ERROR_SYSCALL || $!);
		1663	}
		1664
		1665	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1666	unless (length $tmp) {
		1667	$self->{_on_starttls}
		1668	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1669	&_freetls;
		1670
		1671	if ($self->{on_stoptls}) {
		1672	$self->{on_stoptls}($self);
		1673	return;
168	} else {	1674	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1675	# 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};	1676	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 "line" seperator.
262
263	The C<$callback> will be called when at least one
264	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
265	object itself and the rest of the arguments will be the read lines.
266
267	NOTE: This method will override any callbacks installed via the C<on_read> method.
268
269	=cut
270
271	sub readlines {
272	my ($self, $sep, $cb) = @_;
273
274	if (ref $sep) {
275	$cb = $sep;
276	$sep = "\n";
277
278	} elsif (not defined $sep) {
279	$sep = "\n";
280	}
281
282	my $sep_len = length $sep;
283
284	$self->{on_readline} = $cb;
285
286	$self->on_read (sub {
287	my @lines;
288	my $rb = \$_[0]->{rbuf};
289	my $pos;
290	while (($pos = index ($$rb, $sep)) >= 0) {
291	push @lines, substr $$rb, 0, $pos + $sep_len, '';
292	}
293	$self->{on_readline}->($_[0], @lines);
294	});
295	}
296
297	=item B<write ($data)>
298
299	=item B<write ($callback)>
300
301	=item B<write ($data, $callback)>
302
303	This method will write C<$data> to the filehandle and call the C<$callback>
304	afterwards. If only C<$callback> is provided it will be called when the
305	write buffer becomes empty the next time (or immediately if it already is empty).
306
307	=cut
308
309	sub write {
310	my ($self, $data, $cb) = @_;
311	if (ref $data) { $cb = $data; undef $data }
312	push @{$self->{write_bufs}}, [$data, $cb];
313	$self->_check_writer;
314	}
315
316	sub _check_writer {
317	my ($self) = @_;
318
319	if ($self->{write_w}) {
320	unless ($self->{write_cb}) {
321	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
322	my $wba = shift @{$self->{write_bufs}};
323	$self->{wbuf} .= $wba->[0];	1677	$self->{_eof} = 1;
324	}	1678	}
325	}	1679	}
326	return;	1680
		1681	$self->{_tls_rbuf} .= $tmp;
		1682	$self->_drain_rbuf;
		1683	$self->{tls} or return; # tls session might have gone away in callback
		1684	}
		1685
		1686	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1687	return $self->_tls_error ($tmp)
		1688	if $tmp != $ERROR_WANT_READ
		1689	&& ($tmp != $ERROR_SYSCALL || $!);
		1690
		1691	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1692	$self->{wbuf} .= $tmp;
		1693	$self->_drain_wbuf;
		1694	}
		1695
		1696	$self->{_on_starttls}
		1697	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1698	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1699	}
		1700
		1701	=item $handle->starttls ($tls[, $tls_ctx])
		1702
		1703	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1704	object is created, you can also do that at a later time by calling
		1705	C<starttls>.
		1706
		1707	Starting TLS is currently an asynchronous operation - when you push some
		1708	write data and then call C<< ->starttls >> then TLS negotiation will start
		1709	immediately, after which the queued write data is then sent.
		1710
		1711	The first argument is the same as the C<tls> constructor argument (either
		1712	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1713
		1714	The second argument is the optional C<AnyEvent::TLS> object that is used
		1715	when AnyEvent::Handle has to create its own TLS connection object, or
		1716	a hash reference with C<< key => value >> pairs that will be used to
		1717	construct a new context.
		1718
		1719	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1720	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1721	changed to your liking. Note that the handshake might have already started
		1722	when this function returns.
		1723
		1724	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1725	handshakes on the same stream. Best do not attempt to use the stream after
		1726	stopping TLS.
		1727
		1728	=cut
		1729
		1730	our %TLS_CACHE; #TODO not yet documented, should we?
		1731
		1732	sub starttls {
		1733	my ($self, $tls, $ctx) = @_;
		1734
		1735	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1736	if $self->{tls};
		1737
		1738	$self->{tls} = $tls;
		1739	$self->{tls_ctx} = $ctx if @_ > 2;
		1740
		1741	return unless $self->{fh};
		1742
		1743	require Net::SSLeay;
		1744
		1745	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1746	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1747
		1748	$tls = $self->{tls};
		1749	$ctx = $self->{tls_ctx};
		1750
		1751	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1752
		1753	if ("HASH" eq ref $ctx) {
		1754	require AnyEvent::TLS;
		1755
		1756	if ($ctx->{cache}) {
		1757	my $key = $ctx+0;
		1758	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1759	} else {
		1760	$ctx = new AnyEvent::TLS %$ctx;
		1761	}
		1762	}
327	}	1763
		1764	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1765	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
328		1766
329	my $wba = shift @{$self->{write_bufs}}	1767	# basically, this is deep magic (because SSL_read should have the same issues)
330	or return;	1768	# but the openssl maintainers basically said: "trust us, it just works".
		1769	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1770	# and mismaintained ssleay-module doesn't even offer them).
		1771	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1772	#
		1773	# in short: this is a mess.
		1774	#
		1775	# note that we do not try to keep the length constant between writes as we are required to do.
		1776	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1777	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1778	# have identity issues in that area.
		1779	# Net::SSLeay::CTX_set_mode ($ssl,
		1780	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1781	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1782	Net::SSLeay::CTX_set_mode ($tls, 1|2);
331		1783
332	unless (defined $wba->[0]) {	1784	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
333	$wba->[1]->($self) if $wba->[1];	1785	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
334	$self->_check_writer;	1786
335	return;	1787	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1788
		1789	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1790
		1791	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1792	if $self->{on_starttls};
		1793
		1794	&_dotls; # need to trigger the initial handshake
		1795	$self->start_read; # make sure we actually do read
		1796	}
		1797
		1798	=item $handle->stoptls
		1799
		1800	Shuts down the SSL connection - this makes a proper EOF handshake by
		1801	sending a close notify to the other side, but since OpenSSL doesn't
		1802	support non-blocking shut downs, it is not guarenteed that you can re-use
		1803	the stream afterwards.
		1804
		1805	=cut
		1806
		1807	sub stoptls {
		1808	my ($self) = @_;
		1809
		1810	if ($self->{tls}) {
		1811	Net::SSLeay::shutdown ($self->{tls});
		1812
		1813	&_dotls;
		1814
		1815	# # we don't give a shit. no, we do, but we can't. no...#d#
		1816	# # we, we... have to use openssl :/#d#
		1817	# &_freetls;#d#
		1818	}
		1819	}
		1820
		1821	sub _freetls {
		1822	my ($self) = @_;
		1823
		1824	return unless $self->{tls};
		1825
		1826	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1827	if $self->{tls} > 0;
336	}	1828
		1829	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1830	}
337		1831
338	$self->{wbuf} = $wba->[0];	1832	sub DESTROY {
339	$self->{write_cb} = $wba->[1];	1833	my ($self) = @_;
340		1834
341	$self->{write_w} =	1835	&_freetls;
342	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1836
		1837	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1838
		1839	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1840	my $fh = delete $self->{fh};
		1841	my $wbuf = delete $self->{wbuf};
		1842
		1843	my @linger;
		1844
		1845	push @linger, AE::io $fh, 1, sub {
343	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1846	my $len = syswrite $fh, $wbuf, length $wbuf;
344		1847
345	if (not defined $l) {	1848	if ($len > 0) {
346	return if $! == EAGAIN || $! == EINTR;	1849	substr $wbuf, 0, $len, "";
347	delete $self->{write_w};
348	$self->{on_error}->($self) if $self->{on_error};
349
350	} else {	1850	} else {
351	substr $self->{wbuf}, 0, $l, '';	1851	@linger = (); # end
352
353	if (length ($self->{wbuf}) == 0) {
354	$self->{write_cb}->($self) if $self->{write_cb};
355
356	delete $self->{write_w};
357	delete $self->{wbuf};
358	delete $self->{write_cb};
359
360	$self->_check_writer;
361	}
362	}	1852	}
363	});	1853	};
		1854	push @linger, AE::timer $linger, 0, sub {
		1855	@linger = ();
		1856	};
		1857	}
		1858	}
		1859
		1860	=item $handle->destroy
		1861
		1862	Shuts down the handle object as much as possible - this call ensures that
		1863	no further callbacks will be invoked and as many resources as possible
		1864	will be freed. Any method you will call on the handle object after
		1865	destroying it in this way will be silently ignored (and it will return the
		1866	empty list).
		1867
		1868	Normally, you can just "forget" any references to an AnyEvent::Handle
		1869	object and it will simply shut down. This works in fatal error and EOF
		1870	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1871	callback, so when you want to destroy the AnyEvent::Handle object from
		1872	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1873	that case.
		1874
		1875	Destroying the handle object in this way has the advantage that callbacks
		1876	will be removed as well, so if those are the only reference holders (as
		1877	is common), then one doesn't need to do anything special to break any
		1878	reference cycles.
		1879
		1880	The handle might still linger in the background and write out remaining
		1881	data, as specified by the C<linger> option, however.
		1882
		1883	=cut
		1884
		1885	sub destroy {
		1886	my ($self) = @_;
		1887
		1888	$self->DESTROY;
		1889	%$self = ();
		1890	bless $self, "AnyEvent::Handle::destroyed";
		1891	}
		1892
		1893	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		1894	#nop
		1895	}
		1896
		1897	=item AnyEvent::Handle::TLS_CTX
		1898
		1899	This function creates and returns the AnyEvent::TLS object used by default
		1900	for TLS mode.
		1901
		1902	The context is created by calling L<AnyEvent::TLS> without any arguments.
		1903
		1904	=cut
		1905
		1906	our $TLS_CTX;
		1907
		1908	sub TLS_CTX() {
		1909	$TLS_CTX ||= do {
		1910	require AnyEvent::TLS;
		1911
		1912	new AnyEvent::TLS
		1913	}
364	}	1914	}
365		1915
366	=back	1916	=back
367		1917
		1918
		1919	=head1 NONFREQUENTLY ASKED QUESTIONS
		1920
		1921	=over 4
		1922
		1923	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1924	still get further invocations!
		1925
		1926	That's because AnyEvent::Handle keeps a reference to itself when handling
		1927	read or write callbacks.
		1928
		1929	It is only safe to "forget" the reference inside EOF or error callbacks,
		1930	from within all other callbacks, you need to explicitly call the C<<
		1931	->destroy >> method.
		1932
		1933	=item I get different callback invocations in TLS mode/Why can't I pause
		1934	reading?
		1935
		1936	Unlike, say, TCP, TLS connections do not consist of two independent
		1937	communication channels, one for each direction. Or put differently. The
		1938	read and write directions are not independent of each other: you cannot
		1939	write data unless you are also prepared to read, and vice versa.
		1940
		1941	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1942	callback invocations when you are not expecting any read data - the reason
		1943	is that AnyEvent::Handle always reads in TLS mode.
		1944
		1945	During the connection, you have to make sure that you always have a
		1946	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1947	connection (or when you no longer want to use it) you can call the
		1948	C<destroy> method.
		1949
		1950	=item How do I read data until the other side closes the connection?
		1951
		1952	If you just want to read your data into a perl scalar, the easiest way
		1953	to achieve this is by setting an C<on_read> callback that does nothing,
		1954	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1955	will be in C<$_[0]{rbuf}>:
		1956
		1957	$handle->on_read (sub { });
		1958	$handle->on_eof (undef);
		1959	$handle->on_error (sub {
		1960	my $data = delete $_[0]{rbuf};
		1961	});
		1962
		1963	The reason to use C<on_error> is that TCP connections, due to latencies
		1964	and packets loss, might get closed quite violently with an error, when in
		1965	fact, all data has been received.
		1966
		1967	It is usually better to use acknowledgements when transferring data,
		1968	to make sure the other side hasn't just died and you got the data
		1969	intact. This is also one reason why so many internet protocols have an
		1970	explicit QUIT command.
		1971
		1972	=item I don't want to destroy the handle too early - how do I wait until
		1973	all data has been written?
		1974
		1975	After writing your last bits of data, set the C<on_drain> callback
		1976	and destroy the handle in there - with the default setting of
		1977	C<low_water_mark> this will be called precisely when all data has been
		1978	written to the socket:
		1979
		1980	$handle->push_write (...);
		1981	$handle->on_drain (sub {
		1982	warn "all data submitted to the kernel\n";
		1983	undef $handle;
		1984	});
		1985
		1986	If you just want to queue some data and then signal EOF to the other side,
		1987	consider using C<< ->push_shutdown >> instead.
		1988
		1989	=item I want to contact a TLS/SSL server, I don't care about security.
		1990
		1991	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		1992	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		1993	parameter:
		1994
		1995	tcp_connect $host, $port, sub {
		1996	my ($fh) = @_;
		1997
		1998	my $handle = new AnyEvent::Handle
		1999	fh => $fh,
		2000	tls => "connect",
		2001	on_error => sub { ... };
		2002
		2003	$handle->push_write (...);
		2004	};
		2005
		2006	=item I want to contact a TLS/SSL server, I do care about security.
		2007
		2008	Then you should additionally enable certificate verification, including
		2009	peername verification, if the protocol you use supports it (see
		2010	L<AnyEvent::TLS>, C<verify_peername>).
		2011
		2012	E.g. for HTTPS:
		2013
		2014	tcp_connect $host, $port, sub {
		2015	my ($fh) = @_;
		2016
		2017	my $handle = new AnyEvent::Handle
		2018	fh => $fh,
		2019	peername => $host,
		2020	tls => "connect",
		2021	tls_ctx => { verify => 1, verify_peername => "https" },
		2022	...
		2023
		2024	Note that you must specify the hostname you connected to (or whatever
		2025	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2026	peername verification will be done.
		2027
		2028	The above will use the system-dependent default set of trusted CA
		2029	certificates. If you want to check against a specific CA, add the
		2030	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2031
		2032	tls_ctx => {
		2033	verify => 1,
		2034	verify_peername => "https",
		2035	ca_file => "my-ca-cert.pem",
		2036	},
		2037
		2038	=item I want to create a TLS/SSL server, how do I do that?
		2039
		2040	Well, you first need to get a server certificate and key. You have
		2041	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2042	self-signed certificate (cheap. check the search engine of your choice,
		2043	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2044	nice program for that purpose).
		2045
		2046	Then create a file with your private key (in PEM format, see
		2047	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2048	file should then look like this:
		2049
		2050	-----BEGIN RSA PRIVATE KEY-----
		2051	...header data
		2052	... lots of base64'y-stuff
		2053	-----END RSA PRIVATE KEY-----
		2054
		2055	-----BEGIN CERTIFICATE-----
		2056	... lots of base64'y-stuff
		2057	-----END CERTIFICATE-----
		2058
		2059	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2060	specify this file as C<cert_file>:
		2061
		2062	tcp_server undef, $port, sub {
		2063	my ($fh) = @_;
		2064
		2065	my $handle = new AnyEvent::Handle
		2066	fh => $fh,
		2067	tls => "accept",
		2068	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2069	...
		2070
		2071	When you have intermediate CA certificates that your clients might not
		2072	know about, just append them to the C<cert_file>.
		2073
		2074	=back
		2075
		2076
		2077	=head1 SUBCLASSING AnyEvent::Handle
		2078
		2079	In many cases, you might want to subclass AnyEvent::Handle.
		2080
		2081	To make this easier, a given version of AnyEvent::Handle uses these
		2082	conventions:
		2083
		2084	=over 4
		2085
		2086	=item * all constructor arguments become object members.
		2087
		2088	At least initially, when you pass a C<tls>-argument to the constructor it
		2089	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2090	mutated later on (for example C<tls> will hold the TLS connection object).
		2091
		2092	=item * other object member names are prefixed with an C<_>.
		2093
		2094	All object members not explicitly documented (internal use) are prefixed
		2095	with an underscore character, so the remaining non-C<_>-namespace is free
		2096	for use for subclasses.
		2097
		2098	=item * all members not documented here and not prefixed with an underscore
		2099	are free to use in subclasses.
		2100
		2101	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2102	member variables, but thats just life, at least it is documented.
		2103
		2104	=back
		2105
368	=head1 AUTHOR	2106	=head1 AUTHOR
369		2107
370	Robin Redeker, C<< <elmex at ta-sa.org> >>	2108	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
371		2109
372	=cut	2110	=cut
373		2111
374	1; # End of AnyEvent::Handle	2112	1; # End of AnyEvent::Handle

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