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Revision 1.4 by elmex, Sun Apr 27 20:20:20 2008 UTC vs.
Revision 1.151 by root, Thu Jul 16 04:20:23 2009 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	use warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent;	6	use AnyEvent ();
7	use IO::Handle;	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		8	use Scalar::Util ();
		9	use Carp ();
		10	use Fcntl ();
8	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
9		12
10	=head1 NAME	13	=head1 NAME
11		14
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13		16
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut	17	=cut
19		18
20	our $VERSION = '0.01';	19	our $VERSION = 4.82;
21		20
22	=head1 SYNOPSIS	21	=head1 SYNOPSIS
23		22
24	use AnyEvent;	23	use AnyEvent;
25	use AnyEvent::Handle;	24	use AnyEvent::Handle;
26		25
27	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
28		27
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $hdl; $hdl = new AnyEvent::Handle
		29	fh => \*STDIN,
		30	on_error => sub {
		31	my ($hdl, $fatal, $msg) = @_;
		32	warn "got error $msg\n";
		33	$hdl->destroy;
		34	$cv->send;
		35	);
30		36
31	$ae_fh->on_eof (sub { $cv->broadcast });	37	# send some request line
		38	$hdl->push_write ("getinfo\015\012");
32		39
33	$ae_fh->readlines (sub {	40	# read the response line
		41	$hdl->push_read (line => sub {
34	my ($ae_fh, @lines) = @_;	42	my ($hdl, $line) = @_;
35	for (@lines) {	43	warn "got line <$line>\n";
36	chomp;	44	$cv->send;
37	print "Line: $_";	45	});
		46
		47	$cv->recv;
		48
		49	=head1 DESCRIPTION
		50
		51	This module is a helper module to make it easier to do event-based I/O on
		52	filehandles. For utility functions for doing non-blocking connects and accepts
		53	on sockets see L<AnyEvent::Util>.
		54
		55	The L<AnyEvent::Intro> tutorial contains some well-documented
		56	AnyEvent::Handle examples.
		57
		58	In the following, when the documentation refers to of "bytes" then this
		59	means characters. As sysread and syswrite are used for all I/O, their
		60	treatment of characters applies to this module as well.
		61
		62	All callbacks will be invoked with the handle object as their first
		63	argument.
		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 [MANDATORY]
		76
		77	The filehandle this L<AnyEvent::Handle> object will operate on.
		78
		79	NOTE: The filehandle will be set to non-blocking mode (using
		80	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		81	that mode.
		82
		83	=item on_eof => $cb->($handle)
		84
		85	Set the callback to be called when an end-of-file condition is detected,
		86	i.e. in the case of a socket, when the other side has closed the
		87	connection cleanly, and there are no outstanding read requests in the
		88	queue (if there are read requests, then an EOF counts as an unexpected
		89	connection close and will be flagged as an error).
		90
		91	For sockets, this just means that the other side has stopped sending data,
		92	you can still try to write data, and, in fact, one can return from the EOF
		93	callback and continue writing data, as only the read part has been shut
		94	down.
		95
		96	If an EOF condition has been detected but no C<on_eof> callback has been
		97	set, then a fatal error will be raised with C<$!> set to <0>.
		98
		99	=item on_error => $cb->($handle, $fatal, $message)
		100
		101	This is the error callback, which is called when, well, some error
		102	occured, such as not being able to resolve the hostname, failure to
		103	connect or a read error.
		104
		105	Some errors are fatal (which is indicated by C<$fatal> being true). On
		106	fatal errors the handle object will be destroyed (by a call to C<< ->
		107	destroy >>) after invoking the error callback (which means you are free to
		108	examine the handle object). Examples of fatal errors are an EOF condition
		109	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors.
		110
		111	AnyEvent::Handle tries to find an appropriate error code for you to check
		112	against, but in some cases (TLS errors), this does not work well. It is
		113	recommended to always output the C<$message> argument in human-readable
		114	error messages (it's usually the same as C<"$!">).
		115
		116	Non-fatal errors can be retried by simply returning, but it is recommended
		117	to simply ignore this parameter and instead abondon the handle object
		118	when this callback is invoked. Examples of non-fatal errors are timeouts
		119	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		120
		121	On callback entrance, the value of C<$!> contains the operating system
		122	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		123	C<EPROTO>).
		124
		125	While not mandatory, it is I<highly> recommended to set this callback, as
		126	you will not be notified of errors otherwise. The default simply calls
		127	C<croak>.
		128
		129	=item on_read => $cb->($handle)
		130
		131	This sets the default read callback, which is called when data arrives
		132	and no read request is in the queue (unlike read queue callbacks, this
		133	callback will only be called when at least one octet of data is in the
		134	read buffer).
		135
		136	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		137	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		138	must not enlarge or modify the read buffer, you can only remove data at
		139	the beginning from it.
		140
		141	When an EOF condition is detected then AnyEvent::Handle will first try to
		142	feed all the remaining data to the queued callbacks and C<on_read> before
		143	calling the C<on_eof> callback. If no progress can be made, then a fatal
		144	error will be raised (with C<$!> set to C<EPIPE>).
		145
		146	Note that, unlike requests in the read queue, an C<on_read> callback
		147	doesn't mean you I<require> some data: if there is an EOF and there
		148	are outstanding read requests then an error will be flagged. With an
		149	C<on_read> callback, the C<on_eof> callback will be invoked.
		150
		151	=item on_drain => $cb->($handle)
		152
		153	This sets the callback that is called when the write buffer becomes empty
		154	(or when the callback is set and the buffer is empty already).
		155
		156	To append to the write buffer, use the C<< ->push_write >> method.
		157
		158	This callback is useful when you don't want to put all of your write data
		159	into the queue at once, for example, when you want to write the contents
		160	of some file to the socket you might not want to read the whole file into
		161	memory and push it into the queue, but instead only read more data from
		162	the file when the write queue becomes empty.
		163
		164	=item timeout => $fractional_seconds
		165
		166	If non-zero, then this enables an "inactivity" timeout: whenever this many
		167	seconds pass without a successful read or write on the underlying file
		168	handle, the C<on_timeout> callback will be invoked (and if that one is
		169	missing, a non-fatal C<ETIMEDOUT> error will be raised).
		170
		171	Note that timeout processing is also active when you currently do not have
		172	any outstanding read or write requests: If you plan to keep the connection
		173	idle then you should disable the timout temporarily or ignore the timeout
		174	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		175	restart the timeout.
		176
		177	Zero (the default) disables this timeout.
		178
		179	=item on_timeout => $cb->($handle)
		180
		181	Called whenever the inactivity timeout passes. If you return from this
		182	callback, then the timeout will be reset as if some activity had happened,
		183	so this condition is not fatal in any way.
		184
		185	=item rbuf_max => <bytes>
		186
		187	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		188	when the read buffer ever (strictly) exceeds this size. This is useful to
		189	avoid some forms of denial-of-service attacks.
		190
		191	For example, a server accepting connections from untrusted sources should
		192	be configured to accept only so-and-so much data that it cannot act on
		193	(for example, when expecting a line, an attacker could send an unlimited
		194	amount of data without a callback ever being called as long as the line
		195	isn't finished).
		196
		197	=item autocork => <boolean>
		198
		199	When disabled (the default), then C<push_write> will try to immediately
		200	write the data to the handle, if possible. This avoids having to register
		201	a write watcher and wait for the next event loop iteration, but can
		202	be inefficient if you write multiple small chunks (on the wire, this
		203	disadvantage is usually avoided by your kernel's nagle algorithm, see
		204	C<no_delay>, but this option can save costly syscalls).
		205
		206	When enabled, then writes will always be queued till the next event loop
		207	iteration. This is efficient when you do many small writes per iteration,
		208	but less efficient when you do a single write only per iteration (or when
		209	the write buffer often is full). It also increases write latency.
		210
		211	=item no_delay => <boolean>
		212
		213	When doing small writes on sockets, your operating system kernel might
		214	wait a bit for more data before actually sending it out. This is called
		215	the Nagle algorithm, and usually it is beneficial.
		216
		217	In some situations you want as low a delay as possible, which can be
		218	accomplishd by setting this option to a true value.
		219
		220	The default is your opertaing system's default behaviour (most likely
		221	enabled), this option explicitly enables or disables it, if possible.
		222
		223	=item read_size => <bytes>
		224
		225	The default read block size (the amount of bytes this module will
		226	try to read during each loop iteration, which affects memory
		227	requirements). Default: C<8192>.
		228
		229	=item low_water_mark => <bytes>
		230
		231	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		232	buffer: If the write reaches this size or gets even samller it is
		233	considered empty.
		234
		235	Sometimes it can be beneficial (for performance reasons) to add data to
		236	the write buffer before it is fully drained, but this is a rare case, as
		237	the operating system kernel usually buffers data as well, so the default
		238	is good in almost all cases.
		239
		240	=item linger => <seconds>
		241
		242	If non-zero (default: C<3600>), then the destructor of the
		243	AnyEvent::Handle object will check whether there is still outstanding
		244	write data and will install a watcher that will write this data to the
		245	socket. No errors will be reported (this mostly matches how the operating
		246	system treats outstanding data at socket close time).
		247
		248	This will not work for partial TLS data that could not be encoded
		249	yet. This data will be lost. Calling the C<stoptls> method in time might
		250	help.
		251
		252	=item peername => $string
		253
		254	A string used to identify the remote site - usually the DNS hostname
		255	(I<not> IDN!) used to create the connection, rarely the IP address.
		256
		257	Apart from being useful in error messages, this string is also used in TLS
		258	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		259	verification will be skipped when C<peername> is not specified or
		260	C<undef>.
		261
		262	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		263
		264	When this parameter is given, it enables TLS (SSL) mode, that means
		265	AnyEvent will start a TLS handshake as soon as the conenction has been
		266	established and will transparently encrypt/decrypt data afterwards.
		267
		268	All TLS protocol errors will be signalled as C<EPROTO>, with an
		269	appropriate error message.
		270
		271	TLS mode requires Net::SSLeay to be installed (it will be loaded
		272	automatically when you try to create a TLS handle): this module doesn't
		273	have a dependency on that module, so if your module requires it, you have
		274	to add the dependency yourself.
		275
		276	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		277	C<accept>, and for the TLS client side of a connection, use C<connect>
		278	mode.
		279
		280	You can also provide your own TLS connection object, but you have
		281	to make sure that you call either C<Net::SSLeay::set_connect_state>
		282	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		283	AnyEvent::Handle. Also, this module will take ownership of this connection
		284	object.
		285
		286	At some future point, AnyEvent::Handle might switch to another TLS
		287	implementation, then the option to use your own session object will go
		288	away.
		289
		290	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		291	passing in the wrong integer will lead to certain crash. This most often
		292	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		293	segmentation fault.
		294
		295	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		296
		297	=item tls_ctx => $anyevent_tls
		298
		299	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		300	(unless a connection object was specified directly). If this parameter is
		301	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		302
		303	Instead of an object, you can also specify a hash reference with C<< key
		304	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		305	new TLS context object.
		306
		307	=item on_starttls => $cb->($handle, $success[, $error_message])
		308
		309	This callback will be invoked when the TLS/SSL handshake has finished. If
		310	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		311	(C<on_stoptls> will not be called in this case).
		312
		313	The session in C<< $handle->{tls} >> can still be examined in this
		314	callback, even when the handshake was not successful.
		315
		316	TLS handshake failures will not cause C<on_error> to be invoked when this
		317	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		318
		319	Without this callback, handshake failures lead to C<on_error> being
		320	called, as normal.
		321
		322	Note that you cannot call C<starttls> right again in this callback. If you
		323	need to do that, start an zero-second timer instead whose callback can
		324	then call C<< ->starttls >> again.
		325
		326	=item on_stoptls => $cb->($handle)
		327
		328	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		329	set, then it will be invoked after freeing the TLS session. If it is not,
		330	then a TLS shutdown condition will be treated like a normal EOF condition
		331	on the handle.
		332
		333	The session in C<< $handle->{tls} >> can still be examined in this
		334	callback.
		335
		336	This callback will only be called on TLS shutdowns, not when the
		337	underlying handle signals EOF.
		338
		339	=item json => JSON or JSON::XS object
		340
		341	This is the json coder object used by the C<json> read and write types.
		342
		343	If you don't supply it, then AnyEvent::Handle will create and use a
		344	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		345	texts.
		346
		347	Note that you are responsible to depend on the JSON module if you want to
		348	use this functionality, as AnyEvent does not have a dependency itself.
		349
		350	=back
		351
		352	=cut
		353
		354	sub new {
		355	my $class = shift;
		356	my $self = bless { @_ }, $class;
		357
		358	$self->{fh} or Carp::croak "mandatory argument fh is missing";
		359
		360	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		361
		362	$self->{_activity} = AnyEvent->now;
		363	$self->_timeout;
		364
		365	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		366
		367	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		368	if $self->{tls};
		369
		370	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		371
		372	$self->start_read
		373	if $self->{on_read};
		374
		375	$self->{fh} && $self
		376	}
		377
		378	#sub _shutdown {
		379	# my ($self) = @_;
		380	#
		381	# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
		382	# $self->{_eof} = 1; # tell starttls et. al to stop trying
		383	#
		384	# &_freetls;
		385	#}
		386
		387	sub _error {
		388	my ($self, $errno, $fatal, $message) = @_;
		389
		390	$! = $errno;
		391	$message ||= "$!";
		392
		393	if ($self->{on_error}) {
		394	$self->{on_error}($self, $fatal, $message);
		395	$self->destroy if $fatal;
		396	} elsif ($self->{fh}) {
		397	$self->destroy;
		398	Carp::croak "AnyEvent::Handle uncaught error: $message";
		399	}
		400	}
		401
		402	=item $fh = $handle->fh
		403
		404	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		405
		406	=cut
		407
		408	sub fh { $_[0]{fh} }
		409
		410	=item $handle->on_error ($cb)
		411
		412	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		413
		414	=cut
		415
		416	sub on_error {
		417	$_[0]{on_error} = $_[1];
		418	}
		419
		420	=item $handle->on_eof ($cb)
		421
		422	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		423
		424	=cut
		425
		426	sub on_eof {
		427	$_[0]{on_eof} = $_[1];
		428	}
		429
		430	=item $handle->on_timeout ($cb)
		431
		432	Replace the current C<on_timeout> callback, or disables the callback (but
		433	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		434	argument and method.
		435
		436	=cut
		437
		438	sub on_timeout {
		439	$_[0]{on_timeout} = $_[1];
		440	}
		441
		442	=item $handle->autocork ($boolean)
		443
		444	Enables or disables the current autocork behaviour (see C<autocork>
		445	constructor argument). Changes will only take effect on the next write.
		446
		447	=cut
		448
		449	sub autocork {
		450	$_[0]{autocork} = $_[1];
		451	}
		452
		453	=item $handle->no_delay ($boolean)
		454
		455	Enables or disables the C<no_delay> setting (see constructor argument of
		456	the same name for details).
		457
		458	=cut
		459
		460	sub no_delay {
		461	$_[0]{no_delay} = $_[1];
		462
		463	eval {
		464	local $SIG{__DIE__};
		465	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		466	};
		467	}
		468
		469	=item $handle->on_starttls ($cb)
		470
		471	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		472
		473	=cut
		474
		475	sub on_starttls {
		476	$_[0]{on_starttls} = $_[1];
		477	}
		478
		479	=item $handle->on_stoptls ($cb)
		480
		481	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		482
		483	=cut
		484
		485	sub on_starttls {
		486	$_[0]{on_stoptls} = $_[1];
		487	}
		488
		489	#############################################################################
		490
		491	=item $handle->timeout ($seconds)
		492
		493	Configures (or disables) the inactivity timeout.
		494
		495	=cut
		496
		497	sub timeout {
		498	my ($self, $timeout) = @_;
		499
		500	$self->{timeout} = $timeout;
		501	$self->_timeout;
		502	}
		503
		504	# reset the timeout watcher, as neccessary
		505	# also check for time-outs
		506	sub _timeout {
		507	my ($self) = @_;
		508
		509	if ($self->{timeout}) {
		510	my $NOW = AnyEvent->now;
		511
		512	# when would the timeout trigger?
		513	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		514
		515	# now or in the past already?
		516	if ($after <= 0) {
		517	$self->{_activity} = $NOW;
		518
		519	if ($self->{on_timeout}) {
		520	$self->{on_timeout}($self);
		521	} else {
		522	$self->_error (Errno::ETIMEDOUT);
		523	}
		524
		525	# callback could have changed timeout value, optimise
		526	return unless $self->{timeout};
		527
		528	# calculate new after
		529	$after = $self->{timeout};
		530	}
		531
		532	Scalar::Util::weaken $self;
		533	return unless $self; # ->error could have destroyed $self
		534
		535	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		536	delete $self->{_tw};
		537	$self->_timeout;
		538	});
		539	} else {
		540	delete $self->{_tw};
		541	}
		542	}
		543
		544	#############################################################################
		545
		546	=back
		547
		548	=head2 WRITE QUEUE
		549
		550	AnyEvent::Handle manages two queues per handle, one for writing and one
		551	for reading.
		552
		553	The write queue is very simple: you can add data to its end, and
		554	AnyEvent::Handle will automatically try to get rid of it for you.
		555
		556	When data could be written and the write buffer is shorter then the low
		557	water mark, the C<on_drain> callback will be invoked.
		558
		559	=over 4
		560
		561	=item $handle->on_drain ($cb)
		562
		563	Sets the C<on_drain> callback or clears it (see the description of
		564	C<on_drain> in the constructor).
		565
		566	=cut
		567
		568	sub on_drain {
		569	my ($self, $cb) = @_;
		570
		571	$self->{on_drain} = $cb;
		572
		573	$cb->($self)
		574	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		575	}
		576
		577	=item $handle->push_write ($data)
		578
		579	Queues the given scalar to be written. You can push as much data as you
		580	want (only limited by the available memory), as C<AnyEvent::Handle>
		581	buffers it independently of the kernel.
		582
		583	=cut
		584
		585	sub _drain_wbuf {
		586	my ($self) = @_;
		587
		588	if (!$self->{_ww} && length $self->{wbuf}) {
		589
		590	Scalar::Util::weaken $self;
		591
		592	my $cb = sub {
		593	my $len = syswrite $self->{fh}, $self->{wbuf};
		594
		595	if (defined $len) {
		596	substr $self->{wbuf}, 0, $len, "";
		597
		598	$self->{_activity} = AnyEvent->now;
		599
		600	$self->{on_drain}($self)
		601	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		602	&& $self->{on_drain};
		603
		604	delete $self->{_ww} unless length $self->{wbuf};
		605	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		606	$self->_error ($!, 1);
		607	}
		608	};
		609
		610	# try to write data immediately
		611	$cb->() unless $self->{autocork};
		612
		613	# if still data left in wbuf, we need to poll
		614	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
		615	if length $self->{wbuf};
		616	};
		617	}
		618
		619	our %WH;
		620
		621	sub register_write_type($$) {
		622	$WH{$_[0]} = $_[1];
		623	}
		624
		625	sub push_write {
		626	my $self = shift;
		627
		628	if (@_ > 1) {
		629	my $type = shift;
		630
		631	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		632	->($self, @_);
		633	}
		634
		635	if ($self->{tls}) {
		636	$self->{_tls_wbuf} .= $_[0];
		637
		638	&_dotls ($self);
		639	} else {
		640	$self->{wbuf} .= $_[0];
		641	$self->_drain_wbuf;
		642	}
		643	}
		644
		645	=item $handle->push_write (type => @args)
		646
		647	Instead of formatting your data yourself, you can also let this module do
		648	the job by specifying a type and type-specific arguments.
		649
		650	Predefined types are (if you have ideas for additional types, feel free to
		651	drop by and tell us):
		652
		653	=over 4
		654
		655	=item netstring => $string
		656
		657	Formats the given value as netstring
		658	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		659
		660	=cut
		661
		662	register_write_type netstring => sub {
		663	my ($self, $string) = @_;
		664
		665	(length $string) . ":$string,"
		666	};
		667
		668	=item packstring => $format, $data
		669
		670	An octet string prefixed with an encoded length. The encoding C<$format>
		671	uses the same format as a Perl C<pack> format, but must specify a single
		672	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		673	optional C<!>, C<< < >> or C<< > >> modifier).
		674
		675	=cut
		676
		677	register_write_type packstring => sub {
		678	my ($self, $format, $string) = @_;
		679
		680	pack "$format/a*", $string
		681	};
		682
		683	=item json => $array_or_hashref
		684
		685	Encodes the given hash or array reference into a JSON object. Unless you
		686	provide your own JSON object, this means it will be encoded to JSON text
		687	in UTF-8.
		688
		689	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		690	one end of a handle and read them at the other end without using any
		691	additional framing.
		692
		693	The generated JSON text is guaranteed not to contain any newlines: While
		694	this module doesn't need delimiters after or between JSON texts to be
		695	able to read them, many other languages depend on that.
		696
		697	A simple RPC protocol that interoperates easily with others is to send
		698	JSON arrays (or objects, although arrays are usually the better choice as
		699	they mimic how function argument passing works) and a newline after each
		700	JSON text:
		701
		702	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		703	$handle->push_write ("\012");
		704
		705	An AnyEvent::Handle receiver would simply use the C<json> read type and
		706	rely on the fact that the newline will be skipped as leading whitespace:
		707
		708	$handle->push_read (json => sub { my $array = $_[1]; ... });
		709
		710	Other languages could read single lines terminated by a newline and pass
		711	this line into their JSON decoder of choice.
		712
		713	=cut
		714
		715	register_write_type json => sub {
		716	my ($self, $ref) = @_;
		717
		718	require JSON;
		719
		720	$self->{json} ? $self->{json}->encode ($ref)
		721	: JSON::encode_json ($ref)
		722	};
		723
		724	=item storable => $reference
		725
		726	Freezes the given reference using L<Storable> and writes it to the
		727	handle. Uses the C<nfreeze> format.
		728
		729	=cut
		730
		731	register_write_type storable => sub {
		732	my ($self, $ref) = @_;
		733
		734	require Storable;
		735
		736	pack "w/a*", Storable::nfreeze ($ref)
		737	};
		738
		739	=back
		740
		741	=item $handle->push_shutdown
		742
		743	Sometimes you know you want to close the socket after writing your data
		744	before it was actually written. One way to do that is to replace your
		745	C<on_drain> handler by a callback that shuts down the socket (and set
		746	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		747	replaces the C<on_drain> callback with:
		748
		749	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		750
		751	This simply shuts down the write side and signals an EOF condition to the
		752	the peer.
		753
		754	You can rely on the normal read queue and C<on_eof> handling
		755	afterwards. This is the cleanest way to close a connection.
		756
		757	=cut
		758
		759	sub push_shutdown {
		760	my ($self) = @_;
		761
		762	delete $self->{low_water_mark};
		763	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		764	}
		765
		766	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		767
		768	This function (not method) lets you add your own types to C<push_write>.
		769	Whenever the given C<type> is used, C<push_write> will invoke the code
		770	reference with the handle object and the remaining arguments.
		771
		772	The code reference is supposed to return a single octet string that will
		773	be appended to the write buffer.
		774
		775	Note that this is a function, and all types registered this way will be
		776	global, so try to use unique names.
		777
		778	=cut
		779
		780	#############################################################################
		781
		782	=back
		783
		784	=head2 READ QUEUE
		785
		786	AnyEvent::Handle manages two queues per handle, one for writing and one
		787	for reading.
		788
		789	The read queue is more complex than the write queue. It can be used in two
		790	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		791	a queue.
		792
		793	In the simple case, you just install an C<on_read> callback and whenever
		794	new data arrives, it will be called. You can then remove some data (if
		795	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		796	leave the data there if you want to accumulate more (e.g. when only a
		797	partial message has been received so far).
		798
		799	In the more complex case, you want to queue multiple callbacks. In this
		800	case, AnyEvent::Handle will call the first queued callback each time new
		801	data arrives (also the first time it is queued) and removes it when it has
		802	done its job (see C<push_read>, below).
		803
		804	This way you can, for example, push three line-reads, followed by reading
		805	a chunk of data, and AnyEvent::Handle will execute them in order.
		806
		807	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		808	the specified number of bytes which give an XML datagram.
		809
		810	# in the default state, expect some header bytes
		811	$handle->on_read (sub {
		812	# some data is here, now queue the length-header-read (4 octets)
		813	shift->unshift_read (chunk => 4, sub {
		814	# header arrived, decode
		815	my $len = unpack "N", $_[1];
		816
		817	# now read the payload
		818	shift->unshift_read (chunk => $len, sub {
		819	my $xml = $_[1];
		820	# handle xml
		821	});
		822	});
		823	});
		824
		825	Example 2: Implement a client for a protocol that replies either with "OK"
		826	and another line or "ERROR" for the first request that is sent, and 64
		827	bytes for the second request. Due to the availability of a queue, we can
		828	just pipeline sending both requests and manipulate the queue as necessary
		829	in the callbacks.
		830
		831	When the first callback is called and sees an "OK" response, it will
		832	C<unshift> another line-read. This line-read will be queued I<before> the
		833	64-byte chunk callback.
		834
		835	# request one, returns either "OK + extra line" or "ERROR"
		836	$handle->push_write ("request 1\015\012");
		837
		838	# we expect "ERROR" or "OK" as response, so push a line read
		839	$handle->push_read (line => sub {
		840	# if we got an "OK", we have to _prepend_ another line,
		841	# so it will be read before the second request reads its 64 bytes
		842	# which are already in the queue when this callback is called
		843	# we don't do this in case we got an error
		844	if ($_[1] eq "OK") {
		845	$_[0]->unshift_read (line => sub {
		846	my $response = $_[1];
		847	...
		848	});
38	}	849	}
39	});	850	});
40		851
41	# or use the constructor to pass the callback:	852	# request two, simply returns 64 octets
		853	$handle->push_write ("request 2\015\012");
42		854
43	my $ae_fh2 =	855	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	856	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	857	my $response = $_[1];
46	on_eof => sub {	858	...
47	$cv->broadcast;	859	});
48	},	860
49	on_readline => sub {	861	=over 4
50	my ($ae_fh, @lines) = @_;	862
51	for (@lines) {	863	=cut
52	chomp;	864
53	print "Line: $_";	865	sub _drain_rbuf {
		866	my ($self) = @_;
		867
		868	local $self->{_in_drain} = 1;
		869
		870	if (
		871	defined $self->{rbuf_max}
		872	&& $self->{rbuf_max} < length $self->{rbuf}
		873	) {
		874	$self->_error (Errno::ENOSPC, 1), return;
		875	}
		876
		877	while () {
		878	# we need to use a separate tls read buffer, as we must not receive data while
		879	# we are draining the buffer, and this can only happen with TLS.
		880	$self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
		881
		882	my $len = length $self->{rbuf};
		883
		884	if (my $cb = shift @{ $self->{_queue} }) {
		885	unless ($cb->($self)) {
		886	if ($self->{_eof}) {
		887	# no progress can be made (not enough data and no data forthcoming)
		888	$self->_error (Errno::EPIPE, 1), return;
54	}	889	}
		890
		891	unshift @{ $self->{_queue} }, $cb;
		892	last;
55	}	893	}
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}) {	894	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	895	last unless $len;
122		896
		897	$self->{on_read}($self);
		898
		899	if (
		900	$len == length $self->{rbuf} # if no data has been consumed
		901	&& !@{ $self->{_queue} } # and the queue is still empty
		902	&& $self->{on_read} # but we still have on_read
		903	) {
		904	# no further data will arrive
		905	# so no progress can be made
		906	$self->_error (Errno::EPIPE, 1), return
		907	if $self->{_eof};
		908
		909	last; # more data might arrive
		910	}
		911	} else {
		912	# read side becomes idle
		913	delete $self->{_rw} unless $self->{tls};
		914	last;
		915	}
		916	}
		917
123	} elsif ($self->{on_eof}) {	918	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});
125
126	} elsif ($self->{on_error}) {	919	if ($self->{on_eof}) {
127	$self->on_eof ($self->{on_error});	920	$self->{on_eof}($self)
		921	} else {
		922	$self->_error (0, 1, "Unexpected end-of-file");
		923	}
128	}	924	}
129		925
130	return $self	926	# may need to restart read watcher
		927	unless ($self->{_rw}) {
		928	$self->start_read
		929	if $self->{on_read} || @{ $self->{_queue} };
		930	}
131	}	931	}
132		932
133	=item B<fh>	933	=item $handle->on_read ($cb)
134		934
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	935	This replaces the currently set C<on_read> callback, or clears it (when
136		936	the new callback is C<undef>). See the description of C<on_read> in the
137	=cut	937	constructor.
138
139	sub fh { $_[0]->{fh} }
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		938
149	=cut	939	=cut
150		940
151	sub on_read {	941	sub on_read {
152	my ($self, $cb) = @_;	942	my ($self, $cb) = @_;
		943
153	$self->{on_read} = $cb;	944	$self->{on_read} = $cb;
		945	$self->_drain_rbuf if $cb && !$self->{_in_drain};
		946	}
154		947
155	unless (defined $self->{on_read}) {	948	=item $handle->rbuf
156	delete $self->{on_read_w};	949
		950	Returns the read buffer (as a modifiable lvalue).
		951
		952	You can access the read buffer directly as the C<< ->{rbuf} >>
		953	member, if you want. However, the only operation allowed on the
		954	read buffer (apart from looking at it) is removing data from its
		955	beginning. Otherwise modifying or appending to it is not allowed and will
		956	lead to hard-to-track-down bugs.
		957
		958	NOTE: The read buffer should only be used or modified if the C<on_read>,
		959	C<push_read> or C<unshift_read> methods are used. The other read methods
		960	automatically manage the read buffer.
		961
		962	=cut
		963
		964	sub rbuf : lvalue {
		965	$_[0]{rbuf}
		966	}
		967
		968	=item $handle->push_read ($cb)
		969
		970	=item $handle->unshift_read ($cb)
		971
		972	Append the given callback to the end of the queue (C<push_read>) or
		973	prepend it (C<unshift_read>).
		974
		975	The callback is called each time some additional read data arrives.
		976
		977	It must check whether enough data is in the read buffer already.
		978
		979	If not enough data is available, it must return the empty list or a false
		980	value, in which case it will be called repeatedly until enough data is
		981	available (or an error condition is detected).
		982
		983	If enough data was available, then the callback must remove all data it is
		984	interested in (which can be none at all) and return a true value. After returning
		985	true, it will be removed from the queue.
		986
		987	=cut
		988
		989	our %RH;
		990
		991	sub register_read_type($$) {
		992	$RH{$_[0]} = $_[1];
		993	}
		994
		995	sub push_read {
		996	my $self = shift;
		997	my $cb = pop;
		998
		999	if (@_) {
		1000	my $type = shift;
		1001
		1002	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		1003	->($self, $cb, @_);
		1004	}
		1005
		1006	push @{ $self->{_queue} }, $cb;
		1007	$self->_drain_rbuf unless $self->{_in_drain};
		1008	}
		1009
		1010	sub unshift_read {
		1011	my $self = shift;
		1012	my $cb = pop;
		1013
		1014	if (@_) {
		1015	my $type = shift;
		1016
		1017	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1018	->($self, $cb, @_);
		1019	}
		1020
		1021
		1022	unshift @{ $self->{_queue} }, $cb;
		1023	$self->_drain_rbuf unless $self->{_in_drain};
		1024	}
		1025
		1026	=item $handle->push_read (type => @args, $cb)
		1027
		1028	=item $handle->unshift_read (type => @args, $cb)
		1029
		1030	Instead of providing a callback that parses the data itself you can chose
		1031	between a number of predefined parsing formats, for chunks of data, lines
		1032	etc.
		1033
		1034	Predefined types are (if you have ideas for additional types, feel free to
		1035	drop by and tell us):
		1036
		1037	=over 4
		1038
		1039	=item chunk => $octets, $cb->($handle, $data)
		1040
		1041	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1042	data read to the callback. The callback will never be called with less
		1043	data.
		1044
		1045	Example: read 2 bytes.
		1046
		1047	$handle->push_read (chunk => 2, sub {
		1048	warn "yay ", unpack "H*", $_[1];
		1049	});
		1050
		1051	=cut
		1052
		1053	register_read_type chunk => sub {
		1054	my ($self, $cb, $len) = @_;
		1055
		1056	sub {
		1057	$len <= length $_[0]{rbuf} or return;
		1058	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1059	1
		1060	}
		1061	};
		1062
		1063	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1064
		1065	The callback will be called only once a full line (including the end of
		1066	line marker, C<$eol>) has been read. This line (excluding the end of line
		1067	marker) will be passed to the callback as second argument (C<$line>), and
		1068	the end of line marker as the third argument (C<$eol>).
		1069
		1070	The end of line marker, C<$eol>, can be either a string, in which case it
		1071	will be interpreted as a fixed record end marker, or it can be a regex
		1072	object (e.g. created by C<qr>), in which case it is interpreted as a
		1073	regular expression.
		1074
		1075	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1076	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1077	protocols).
		1078
		1079	Partial lines at the end of the stream will never be returned, as they are
		1080	not marked by the end of line marker.
		1081
		1082	=cut
		1083
		1084	register_read_type line => sub {
		1085	my ($self, $cb, $eol) = @_;
		1086
		1087	if (@_ < 3) {
		1088	# this is more than twice as fast as the generic code below
		1089	sub {
		1090	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1091
		1092	$cb->($_[0], $1, $2);
		1093	1
		1094	}
		1095	} else {
		1096	$eol = quotemeta $eol unless ref $eol;
		1097	$eol = qr|^(.*?)($eol)|s;
		1098
		1099	sub {
		1100	$_[0]{rbuf} =~ s/$eol// or return;
		1101
		1102	$cb->($_[0], $1, $2);
		1103	1
		1104	}
		1105	}
		1106	};
		1107
		1108	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1109
		1110	Makes a regex match against the regex object C<$accept> and returns
		1111	everything up to and including the match.
		1112
		1113	Example: read a single line terminated by '\n'.
		1114
		1115	$handle->push_read (regex => qr<\n>, sub { ... });
		1116
		1117	If C<$reject> is given and not undef, then it determines when the data is
		1118	to be rejected: it is matched against the data when the C<$accept> regex
		1119	does not match and generates an C<EBADMSG> error when it matches. This is
		1120	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1121	receive buffer overflow).
		1122
		1123	Example: expect a single decimal number followed by whitespace, reject
		1124	anything else (not the use of an anchor).
		1125
		1126	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1127
		1128	If C<$skip> is given and not C<undef>, then it will be matched against
		1129	the receive buffer when neither C<$accept> nor C<$reject> match,
		1130	and everything preceding and including the match will be accepted
		1131	unconditionally. This is useful to skip large amounts of data that you
		1132	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1133	have to start matching from the beginning. This is purely an optimisation
		1134	and is usually worth only when you expect more than a few kilobytes.
		1135
		1136	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1137	expect the header to be very large (it isn't in practise, but...), we use
		1138	a skip regex to skip initial portions. The skip regex is tricky in that
		1139	it only accepts something not ending in either \015 or \012, as these are
		1140	required for the accept regex.
		1141
		1142	$handle->push_read (regex =>
		1143	qr<\015\012\015\012>,
		1144	undef, # no reject
		1145	qr<^.*[^\015\012]>,
		1146	sub { ... });
		1147
		1148	=cut
		1149
		1150	register_read_type regex => sub {
		1151	my ($self, $cb, $accept, $reject, $skip) = @_;
		1152
		1153	my $data;
		1154	my $rbuf = \$self->{rbuf};
		1155
		1156	sub {
		1157	# accept
		1158	if ($$rbuf =~ $accept) {
		1159	$data .= substr $$rbuf, 0, $+[0], "";
		1160	$cb->($self, $data);
157	return;	1161	return 1;
		1162	}
		1163
		1164	# reject
		1165	if ($reject && $$rbuf =~ $reject) {
		1166	$self->_error (Errno::EBADMSG);
		1167	}
		1168
		1169	# skip
		1170	if ($skip && $$rbuf =~ $skip) {
		1171	$data .= substr $$rbuf, 0, $+[0], "";
		1172	}
		1173
		1174	()
158	}	1175	}
159		1176	};
160	$self->{on_read_w} =	1177
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1178	=item netstring => $cb->($handle, $string)
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1179
163	my $rbuf_len = length $self->{rbuf};	1180	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
164	my $l;	1181
165	if (defined $self->{read_size}) {	1182	Throws an error with C<$!> set to EBADMSG on format violations.
166	$l = sysread $self->{fh}, $self->{rbuf},	1183
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1184	=cut
168	} else {	1185
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1186	register_read_type netstring => sub {
		1187	my ($self, $cb) = @_;
		1188
		1189	sub {
		1190	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1191	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1192	$self->_error (Errno::EBADMSG);
170	}	1193	}
171	#d# warn "READL $l [$self->{rbuf}]\n";	1194	return;
		1195	}
172		1196
173	if (not defined $l) {	1197	my $len = $1;
174	return if $! == EAGAIN || $! == EINTR;
175	$self->{on_error}->($self) if $self->{on_error};
176	delete $self->{on_read_w};
177		1198
178	} elsif ($l == 0) {	1199	$self->unshift_read (chunk => $len, sub {
179	$self->{on_eof}->($self) if $self->{on_eof};	1200	my $string = $_[1];
180	delete $self->{on_read_w};	1201	$_[0]->unshift_read (chunk => 1, sub {
181		1202	if ($_[1] eq ",") {
		1203	$cb->($_[0], $string);
182	} else {	1204	} else {
183	$self->{on_read}->($self);	1205	$self->_error (Errno::EBADMSG);
		1206	}
		1207	});
		1208	});
		1209
		1210	1
		1211	}
		1212	};
		1213
		1214	=item packstring => $format, $cb->($handle, $string)
		1215
		1216	An octet string prefixed with an encoded length. The encoding C<$format>
		1217	uses the same format as a Perl C<pack> format, but must specify a single
		1218	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1219	optional C<!>, C<< < >> or C<< > >> modifier).
		1220
		1221	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1222	EPP uses a prefix of C<N> (4 octtes).
		1223
		1224	Example: read a block of data prefixed by its length in BER-encoded
		1225	format (very efficient).
		1226
		1227	$handle->push_read (packstring => "w", sub {
		1228	my ($handle, $data) = @_;
		1229	});
		1230
		1231	=cut
		1232
		1233	register_read_type packstring => sub {
		1234	my ($self, $cb, $format) = @_;
		1235
		1236	sub {
		1237	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1238	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1239	or return;
		1240
		1241	$format = length pack $format, $len;
		1242
		1243	# bypass unshift if we already have the remaining chunk
		1244	if ($format + $len <= length $_[0]{rbuf}) {
		1245	my $data = substr $_[0]{rbuf}, $format, $len;
		1246	substr $_[0]{rbuf}, 0, $format + $len, "";
		1247	$cb->($_[0], $data);
		1248	} else {
		1249	# remove prefix
		1250	substr $_[0]{rbuf}, 0, $format, "";
		1251
		1252	# read remaining chunk
		1253	$_[0]->unshift_read (chunk => $len, $cb);
		1254	}
		1255
		1256	1
		1257	}
		1258	};
		1259
		1260	=item json => $cb->($handle, $hash_or_arrayref)
		1261
		1262	Reads a JSON object or array, decodes it and passes it to the
		1263	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1264
		1265	If a C<json> object was passed to the constructor, then that will be used
		1266	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1267
		1268	This read type uses the incremental parser available with JSON version
		1269	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1270	dependency on your own: this module will load the JSON module, but
		1271	AnyEvent does not depend on it itself.
		1272
		1273	Since JSON texts are fully self-delimiting, the C<json> read and write
		1274	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1275	the C<json> write type description, above, for an actual example.
		1276
		1277	=cut
		1278
		1279	register_read_type json => sub {
		1280	my ($self, $cb) = @_;
		1281
		1282	my $json = $self->{json} ||=
		1283	eval { require JSON::XS; JSON::XS->new->utf8 }
		1284	|| do { require JSON; JSON->new->utf8 };
		1285
		1286	my $data;
		1287	my $rbuf = \$self->{rbuf};
		1288
		1289	sub {
		1290	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1291
		1292	if ($ref) {
		1293	$self->{rbuf} = $json->incr_text;
		1294	$json->incr_text = "";
		1295	$cb->($self, $ref);
		1296
		1297	1
		1298	} elsif ($@) {
		1299	# error case
		1300	$json->incr_skip;
		1301
		1302	$self->{rbuf} = $json->incr_text;
		1303	$json->incr_text = "";
		1304
		1305	$self->_error (Errno::EBADMSG);
		1306
		1307	()
		1308	} else {
		1309	$self->{rbuf} = "";
		1310
		1311	()
		1312	}
		1313	}
		1314	};
		1315
		1316	=item storable => $cb->($handle, $ref)
		1317
		1318	Deserialises a L<Storable> frozen representation as written by the
		1319	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1320	data).
		1321
		1322	Raises C<EBADMSG> error if the data could not be decoded.
		1323
		1324	=cut
		1325
		1326	register_read_type storable => sub {
		1327	my ($self, $cb) = @_;
		1328
		1329	require Storable;
		1330
		1331	sub {
		1332	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1333	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1334	or return;
		1335
		1336	my $format = length pack "w", $len;
		1337
		1338	# bypass unshift if we already have the remaining chunk
		1339	if ($format + $len <= length $_[0]{rbuf}) {
		1340	my $data = substr $_[0]{rbuf}, $format, $len;
		1341	substr $_[0]{rbuf}, 0, $format + $len, "";
		1342	$cb->($_[0], Storable::thaw ($data));
		1343	} else {
		1344	# remove prefix
		1345	substr $_[0]{rbuf}, 0, $format, "";
		1346
		1347	# read remaining chunk
		1348	$_[0]->unshift_read (chunk => $len, sub {
		1349	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1350	$cb->($_[0], $ref);
		1351	} else {
		1352	$self->_error (Errno::EBADMSG);
		1353	}
		1354	});
		1355	}
		1356
		1357	1
		1358	}
		1359	};
		1360
		1361	=back
		1362
		1363	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1364
		1365	This function (not method) lets you add your own types to C<push_read>.
		1366
		1367	Whenever the given C<type> is used, C<push_read> will invoke the code
		1368	reference with the handle object, the callback and the remaining
		1369	arguments.
		1370
		1371	The code reference is supposed to return a callback (usually a closure)
		1372	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1373
		1374	It should invoke the passed callback when it is done reading (remember to
		1375	pass C<$handle> as first argument as all other callbacks do that).
		1376
		1377	Note that this is a function, and all types registered this way will be
		1378	global, so try to use unique names.
		1379
		1380	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1381	search for C<register_read_type>)).
		1382
		1383	=item $handle->stop_read
		1384
		1385	=item $handle->start_read
		1386
		1387	In rare cases you actually do not want to read anything from the
		1388	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1389	any queued callbacks will be executed then. To start reading again, call
		1390	C<start_read>.
		1391
		1392	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1393	you change the C<on_read> callback or push/unshift a read callback, and it
		1394	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1395	there are any read requests in the queue.
		1396
		1397	These methods will have no effect when in TLS mode (as TLS doesn't support
		1398	half-duplex connections).
		1399
		1400	=cut
		1401
		1402	sub stop_read {
		1403	my ($self) = @_;
		1404
		1405	delete $self->{_rw} unless $self->{tls};
		1406	}
		1407
		1408	sub start_read {
		1409	my ($self) = @_;
		1410
		1411	unless ($self->{_rw} || $self->{_eof}) {
		1412	Scalar::Util::weaken $self;
		1413
		1414	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1415	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1416	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1417
		1418	if ($len > 0) {
		1419	$self->{_activity} = AnyEvent->now;
		1420
		1421	if ($self->{tls}) {
		1422	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1423
		1424	&_dotls ($self);
		1425	} else {
		1426	$self->_drain_rbuf unless $self->{_in_drain};
		1427	}
		1428
		1429	} elsif (defined $len) {
		1430	delete $self->{_rw};
		1431	$self->{_eof} = 1;
		1432	$self->_drain_rbuf unless $self->{_in_drain};
		1433
		1434	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1435	return $self->_error ($!, 1);
184	}	1436	}
185	});	1437	});
		1438	}
186	}	1439	}
187		1440
188	=item B<on_error ($callback)>	1441	our $ERROR_SYSCALL;
		1442	our $ERROR_WANT_READ;
189		1443
190	Whenever a read or write operation resulted in an error the C<$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 {	1444	sub _tls_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, $cb) = @_;	1445	my ($self, $err) = @_;
240		1446
241	$self->{read_cb} = $cb;	1447	return $self->_error ($!, 1)
242	my $old_blk_size = $self->{read_block_size};	1448	if $err == Net::SSLeay::ERROR_SYSCALL ();
243	$self->{read_block_size} = $len;
244		1449
245	$self->on_read (sub {	1450	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247		1451
248	if ($len == length $_[0]->{rbuf}) {	1452	# reduce error string to look less scary
249	$_[0]->{read_block_size} = $old_blk_size;	1453	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
250	$_[0]->on_read (undef);	1454
251	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));	1455	if ($self->{_on_starttls}) {
		1456	(delete $self->{_on_starttls})->($self, undef, $err);
		1457	&_freetls;
		1458	} else {
		1459	&_freetls;
		1460	$self->_error (Errno::EPROTO, 1, $err);
		1461	}
		1462	}
		1463
		1464	# poll the write BIO and send the data if applicable
		1465	# also decode read data if possible
		1466	# this is basiclaly our TLS state machine
		1467	# more efficient implementations are possible with openssl,
		1468	# but not with the buggy and incomplete Net::SSLeay.
		1469	sub _dotls {
		1470	my ($self) = @_;
		1471
		1472	my $tmp;
		1473
		1474	if (length $self->{_tls_wbuf}) {
		1475	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1476	substr $self->{_tls_wbuf}, 0, $tmp, "";
252	}	1477	}
		1478
		1479	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1480	return $self->_tls_error ($tmp)
		1481	if $tmp != $ERROR_WANT_READ
		1482	&& ($tmp != $ERROR_SYSCALL || $!);
253	});	1483	}
254	}
255		1484
256	=item B<readlines ($callback)>	1485	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1486	unless (length $tmp) {
		1487	$self->{_on_starttls}
		1488	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1489	&_freetls;
257		1490
258	=item B<readlines ($sep, $callback)>	1491	if ($self->{on_stoptls}) {
259		1492	$self->{on_stoptls}($self);
260	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">	1493	return;
261	if C<$sep> is not provided. C<$sep> will be used as part of a regex, so it can be	1494	} else {
262	a regex itself and won't be quoted!	1495	# let's treat SSL-eof as we treat normal EOF
263		1496	delete $self->{_rw};
264	The C<$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];	1497	$self->{_eof} = 1;
316	}	1498	}
317	}	1499	}
318	return;	1500
		1501	$self->{_tls_rbuf} .= $tmp;
		1502	$self->_drain_rbuf unless $self->{_in_drain};
		1503	$self->{tls} or return; # tls session might have gone away in callback
		1504	}
		1505
		1506	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1507	return $self->_tls_error ($tmp)
		1508	if $tmp != $ERROR_WANT_READ
		1509	&& ($tmp != $ERROR_SYSCALL || $!);
		1510
		1511	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1512	$self->{wbuf} .= $tmp;
		1513	$self->_drain_wbuf;
		1514	}
		1515
		1516	$self->{_on_starttls}
		1517	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1518	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1519	}
		1520
		1521	=item $handle->starttls ($tls[, $tls_ctx])
		1522
		1523	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1524	object is created, you can also do that at a later time by calling
		1525	C<starttls>.
		1526
		1527	The first argument is the same as the C<tls> constructor argument (either
		1528	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1529
		1530	The second argument is the optional C<AnyEvent::TLS> object that is used
		1531	when AnyEvent::Handle has to create its own TLS connection object, or
		1532	a hash reference with C<< key => value >> pairs that will be used to
		1533	construct a new context.
		1534
		1535	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1536	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1537	changed to your liking. Note that the handshake might have already started
		1538	when this function returns.
		1539
		1540	If it an error to start a TLS handshake more than once per
		1541	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1542
		1543	=cut
		1544
		1545	our %TLS_CACHE; #TODO not yet documented, should we?
		1546
		1547	sub starttls {
		1548	my ($self, $ssl, $ctx) = @_;
		1549
		1550	require Net::SSLeay;
		1551
		1552	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
		1553	if $self->{tls};
		1554
		1555	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1556	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1557
		1558	$ctx ||= $self->{tls_ctx};
		1559
		1560	if ("HASH" eq ref $ctx) {
		1561	require AnyEvent::TLS;
		1562
		1563	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
		1564
		1565	if ($ctx->{cache}) {
		1566	my $key = $ctx+0;
		1567	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1568	} else {
		1569	$ctx = new AnyEvent::TLS %$ctx;
		1570	}
		1571	}
319	}	1572
		1573	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1574	$self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername});
320		1575
321	my $wba = shift @{$self->{write_bufs}}	1576	# basically, this is deep magic (because SSL_read should have the same issues)
322	or return;	1577	# but the openssl maintainers basically said: "trust us, it just works".
		1578	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1579	# and mismaintained ssleay-module doesn't even offer them).
		1580	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1581	#
		1582	# in short: this is a mess.
		1583	#
		1584	# note that we do not try to keep the length constant between writes as we are required to do.
		1585	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1586	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1587	# have identity issues in that area.
		1588	# Net::SSLeay::CTX_set_mode ($ssl,
		1589	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1590	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1591	Net::SSLeay::CTX_set_mode ($ssl, 1|2);
323		1592
324	unless (defined $wba->[0]) {	1593	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
325	$wba->[1]->($self) if $wba->[1];	1594	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
326	$self->_check_writer;	1595
327	return;	1596	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1597
		1598	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1599	if $self->{on_starttls};
		1600
		1601	&_dotls; # need to trigger the initial handshake
		1602	$self->start_read; # make sure we actually do read
		1603	}
		1604
		1605	=item $handle->stoptls
		1606
		1607	Shuts down the SSL connection - this makes a proper EOF handshake by
		1608	sending a close notify to the other side, but since OpenSSL doesn't
		1609	support non-blocking shut downs, it is not possible to re-use the stream
		1610	afterwards.
		1611
		1612	=cut
		1613
		1614	sub stoptls {
		1615	my ($self) = @_;
		1616
		1617	if ($self->{tls}) {
		1618	Net::SSLeay::shutdown ($self->{tls});
		1619
		1620	&_dotls;
		1621
		1622	# # we don't give a shit. no, we do, but we can't. no...#d#
		1623	# # we, we... have to use openssl :/#d#
		1624	# &_freetls;#d#
		1625	}
		1626	}
		1627
		1628	sub _freetls {
		1629	my ($self) = @_;
		1630
		1631	return unless $self->{tls};
		1632
		1633	$self->{tls_ctx}->_put_session (delete $self->{tls});
328	}	1634
		1635	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1636	}
329		1637
330	$self->{wbuf} = $wba->[0];	1638	sub DESTROY {
331	$self->{write_cb} = $wba->[1];	1639	my ($self) = @_;
332		1640
333	$self->{write_w} =	1641	&_freetls;
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1642
		1643	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1644
		1645	if ($linger && length $self->{wbuf}) {
		1646	my $fh = delete $self->{fh};
		1647	my $wbuf = delete $self->{wbuf};
		1648
		1649	my @linger;
		1650
		1651	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1652	my $len = syswrite $fh, $wbuf, length $wbuf;
336		1653
337	if (not defined $l) {	1654	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	1655	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	1656	} else {
343	substr $self->{wbuf}, 0, $l, '';	1657	@linger = (); # end
344
345	if (length ($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	}	1658	}
355	});	1659	});
		1660	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1661	@linger = ();
		1662	});
		1663	}
		1664	}
		1665
		1666	=item $handle->destroy
		1667
		1668	Shuts down the handle object as much as possible - this call ensures that
		1669	no further callbacks will be invoked and as many resources as possible
		1670	will be freed. You must not call any methods on the object afterwards.
		1671
		1672	Normally, you can just "forget" any references to an AnyEvent::Handle
		1673	object and it will simply shut down. This works in fatal error and EOF
		1674	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1675	callback, so when you want to destroy the AnyEvent::Handle object from
		1676	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1677	that case.
		1678
		1679	Destroying the handle object in this way has the advantage that callbacks
		1680	will be removed as well, so if those are the only reference holders (as
		1681	is common), then one doesn't need to do anything special to break any
		1682	reference cycles.
		1683
		1684	The handle might still linger in the background and write out remaining
		1685	data, as specified by the C<linger> option, however.
		1686
		1687	=cut
		1688
		1689	sub destroy {
		1690	my ($self) = @_;
		1691
		1692	$self->DESTROY;
		1693	%$self = ();
		1694	}
		1695
		1696	=item AnyEvent::Handle::TLS_CTX
		1697
		1698	This function creates and returns the AnyEvent::TLS object used by default
		1699	for TLS mode.
		1700
		1701	The context is created by calling L<AnyEvent::TLS> without any arguments.
		1702
		1703	=cut
		1704
		1705	our $TLS_CTX;
		1706
		1707	sub TLS_CTX() {
		1708	$TLS_CTX ||= do {
		1709	require AnyEvent::TLS;
		1710
		1711	new AnyEvent::TLS
		1712	}
356	}	1713	}
357		1714
358	=back	1715	=back
359		1716
		1717
		1718	=head1 NONFREQUENTLY ASKED QUESTIONS
		1719
		1720	=over 4
		1721
		1722	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1723	still get further invocations!
		1724
		1725	That's because AnyEvent::Handle keeps a reference to itself when handling
		1726	read or write callbacks.
		1727
		1728	It is only safe to "forget" the reference inside EOF or error callbacks,
		1729	from within all other callbacks, you need to explicitly call the C<<
		1730	->destroy >> method.
		1731
		1732	=item I get different callback invocations in TLS mode/Why can't I pause
		1733	reading?
		1734
		1735	Unlike, say, TCP, TLS connections do not consist of two independent
		1736	communication channels, one for each direction. Or put differently. The
		1737	read and write directions are not independent of each other: you cannot
		1738	write data unless you are also prepared to read, and vice versa.
		1739
		1740	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1741	callback invocations when you are not expecting any read data - the reason
		1742	is that AnyEvent::Handle always reads in TLS mode.
		1743
		1744	During the connection, you have to make sure that you always have a
		1745	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1746	connection (or when you no longer want to use it) you can call the
		1747	C<destroy> method.
		1748
		1749	=item How do I read data until the other side closes the connection?
		1750
		1751	If you just want to read your data into a perl scalar, the easiest way
		1752	to achieve this is by setting an C<on_read> callback that does nothing,
		1753	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1754	will be in C<$_[0]{rbuf}>:
		1755
		1756	$handle->on_read (sub { });
		1757	$handle->on_eof (undef);
		1758	$handle->on_error (sub {
		1759	my $data = delete $_[0]{rbuf};
		1760	});
		1761
		1762	The reason to use C<on_error> is that TCP connections, due to latencies
		1763	and packets loss, might get closed quite violently with an error, when in
		1764	fact, all data has been received.
		1765
		1766	It is usually better to use acknowledgements when transferring data,
		1767	to make sure the other side hasn't just died and you got the data
		1768	intact. This is also one reason why so many internet protocols have an
		1769	explicit QUIT command.
		1770
		1771	=item I don't want to destroy the handle too early - how do I wait until
		1772	all data has been written?
		1773
		1774	After writing your last bits of data, set the C<on_drain> callback
		1775	and destroy the handle in there - with the default setting of
		1776	C<low_water_mark> this will be called precisely when all data has been
		1777	written to the socket:
		1778
		1779	$handle->push_write (...);
		1780	$handle->on_drain (sub {
		1781	warn "all data submitted to the kernel\n";
		1782	undef $handle;
		1783	});
		1784
		1785	If you just want to queue some data and then signal EOF to the other side,
		1786	consider using C<< ->push_shutdown >> instead.
		1787
		1788	=item I want to contact a TLS/SSL server, I don't care about security.
		1789
		1790	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		1791	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		1792	parameter:
		1793
		1794	tcp_connect $host, $port, sub {
		1795	my ($fh) = @_;
		1796
		1797	my $handle = new AnyEvent::Handle
		1798	fh => $fh,
		1799	tls => "connect",
		1800	on_error => sub { ... };
		1801
		1802	$handle->push_write (...);
		1803	};
		1804
		1805	=item I want to contact a TLS/SSL server, I do care about security.
		1806
		1807	Then you should additionally enable certificate verification, including
		1808	peername verification, if the protocol you use supports it (see
		1809	L<AnyEvent::TLS>, C<verify_peername>).
		1810
		1811	E.g. for HTTPS:
		1812
		1813	tcp_connect $host, $port, sub {
		1814	my ($fh) = @_;
		1815
		1816	my $handle = new AnyEvent::Handle
		1817	fh => $fh,
		1818	peername => $host,
		1819	tls => "connect",
		1820	tls_ctx => { verify => 1, verify_peername => "https" },
		1821	...
		1822
		1823	Note that you must specify the hostname you connected to (or whatever
		1824	"peername" the protocol needs) as the C<peername> argument, otherwise no
		1825	peername verification will be done.
		1826
		1827	The above will use the system-dependent default set of trusted CA
		1828	certificates. If you want to check against a specific CA, add the
		1829	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		1830
		1831	tls_ctx => {
		1832	verify => 1,
		1833	verify_peername => "https",
		1834	ca_file => "my-ca-cert.pem",
		1835	},
		1836
		1837	=item I want to create a TLS/SSL server, how do I do that?
		1838
		1839	Well, you first need to get a server certificate and key. You have
		1840	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		1841	self-signed certificate (cheap. check the search engine of your choice,
		1842	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		1843	nice program for that purpose).
		1844
		1845	Then create a file with your private key (in PEM format, see
		1846	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		1847	file should then look like this:
		1848
		1849	-----BEGIN RSA PRIVATE KEY-----
		1850	...header data
		1851	... lots of base64'y-stuff
		1852	-----END RSA PRIVATE KEY-----
		1853
		1854	-----BEGIN CERTIFICATE-----
		1855	... lots of base64'y-stuff
		1856	-----END CERTIFICATE-----
		1857
		1858	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		1859	specify this file as C<cert_file>:
		1860
		1861	tcp_server undef, $port, sub {
		1862	my ($fh) = @_;
		1863
		1864	my $handle = new AnyEvent::Handle
		1865	fh => $fh,
		1866	tls => "accept",
		1867	tls_ctx => { cert_file => "my-server-keycert.pem" },
		1868	...
		1869
		1870	When you have intermediate CA certificates that your clients might not
		1871	know about, just append them to the C<cert_file>.
		1872
		1873	=back
		1874
		1875
		1876	=head1 SUBCLASSING AnyEvent::Handle
		1877
		1878	In many cases, you might want to subclass AnyEvent::Handle.
		1879
		1880	To make this easier, a given version of AnyEvent::Handle uses these
		1881	conventions:
		1882
		1883	=over 4
		1884
		1885	=item * all constructor arguments become object members.
		1886
		1887	At least initially, when you pass a C<tls>-argument to the constructor it
		1888	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1889	mutated later on (for example C<tls> will hold the TLS connection object).
		1890
		1891	=item * other object member names are prefixed with an C<_>.
		1892
		1893	All object members not explicitly documented (internal use) are prefixed
		1894	with an underscore character, so the remaining non-C<_>-namespace is free
		1895	for use for subclasses.
		1896
		1897	=item * all members not documented here and not prefixed with an underscore
		1898	are free to use in subclasses.
		1899
		1900	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1901	member variables, but thats just life, at least it is documented.
		1902
		1903	=back
		1904
360	=head1 AUTHOR	1905	=head1 AUTHOR
361		1906
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	1907	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363		1908
364	=cut	1909	=cut
365		1910
366	1; # End of AnyEvent::Handle	1911	1; # End of AnyEvent::Handle

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