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Revision 1.241 by root, Fri Sep 5 22:17:26 2014 UTC

1	package AnyEvent::Handle;
2
3	no 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 streaming 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	AE::log error => $msg;
		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, $line) = @_;
35	for (@lines) {	27	say "got line <$line>";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
		32
		33	=head1 DESCRIPTION
		34
		35	This is a helper module to make it easier to do event-based I/O on
		36	stream-based filehandles (sockets, pipes, and other stream things).
		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
		41	In the following, where the documentation refers to "bytes", it means
		42	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 = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
		82	=head1 METHODS
		83
		84	=over 4
		85
		86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
		87
		88	The constructor supports these arguments (all as C<< key => value >> pairs).
		89
		90	=over 4
		91
		92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		93
		94	The filehandle this L<AnyEvent::Handle> object will operate on.
		95	NOTE: The filehandle will be set to non-blocking mode (using
		96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
		98
		99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		100
		101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
		104
		105	You have to specify either this parameter, or C<fh>, above.
		106
		107	It is possible to push requests on the read and write queues, and modify
		108	properties of the stream, even while AnyEvent::Handle is connecting.
		109
		110	When this parameter is specified, then the C<on_prepare>,
		111	C<on_connect_error> and C<on_connect> callbacks will be called under the
		112	appropriate circumstances:
		113
		114	=over 4
		115
		116	=item on_prepare => $cb->($handle)
		117
		118	This (rarely used) callback is called before a new connection is
		119	attempted, but after the file handle has been created (you can access that
		120	file handle via C<< $handle->{fh} >>). It could be used to prepare the
		121	file handle with parameters required for the actual connect (as opposed to
		122	settings that can be changed when the connection is already established).
		123
		124	The return value of this callback should be the connect timeout value in
		125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
		126	default timeout is to be used).
		127
		128	=item on_connect => $cb->($handle, $host, $port, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback. At the time it is called the
		134	read and write queues, EOF status, TLS status and similar properties of
		135	the handle will have been reset.
		136
		137	It is not allowed to use the read or write queues while the handle object
		138	is connecting.
		139
		140	If, for some reason, the handle is not acceptable, calling C<$retry> will
		141	continue with the next connection target (in case of multi-homed hosts or
		142	SRV records there can be multiple connection endpoints). The C<$retry>
		143	callback can be invoked after the connect callback returns, i.e. one can
		144	start a handshake and then decide to retry with the next host if the
		145	handshake fails.
		146
		147	In most cases, you should ignore the C<$retry> parameter.
		148
		149	=item on_connect_error => $cb->($handle, $message)
		150
		151	This callback is called when the connection could not be
		152	established. C<$!> will contain the relevant error code, and C<$message> a
		153	message describing it (usually the same as C<"$!">).
		154
		155	If this callback isn't specified, then C<on_error> will be called with a
		156	fatal error instead.
		157
		158	=back
		159
		160	=item on_error => $cb->($handle, $fatal, $message)
		161
		162	This is the error callback, which is called when, well, some error
		163	occured, such as not being able to resolve the hostname, failure to
		164	connect, or a read error.
		165
		166	Some errors are fatal (which is indicated by C<$fatal> being true). On
		167	fatal errors the handle object will be destroyed (by a call to C<< ->
		168	destroy >>) after invoking the error callback (which means you are free to
		169	examine the handle object). Examples of fatal errors are an EOF condition
		170	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		171	cases where the other side can close the connection at will, it is
		172	often easiest to not report C<EPIPE> errors in this callback.
		173
		174	AnyEvent::Handle tries to find an appropriate error code for you to check
		175	against, but in some cases (TLS errors), this does not work well.
		176
		177	If you report the error to the user, it is recommended to always output
		178	the C<$message> argument in human-readable error messages (you don't need
		179	to report C<"$!"> if you report C<$message>).
		180
		181	If you want to react programmatically to the error, then looking at C<$!>
		182	and comparing it against some of the documented C<Errno> values is usually
		183	better than looking at the C<$message>.
		184
		185	Non-fatal errors can be retried by returning, but it is recommended
		186	to simply ignore this parameter and instead abondon the handle object
		187	when this callback is invoked. Examples of non-fatal errors are timeouts
		188	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		189
		190	On entry to the callback, the value of C<$!> contains the operating
		191	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		192	C<EPROTO>).
		193
		194	While not mandatory, it is I<highly> recommended to set this callback, as
		195	you will not be notified of errors otherwise. The default just calls
		196	C<croak>.
		197
		198	=item on_read => $cb->($handle)
		199
		200	This sets the default read callback, which is called when data arrives
		201	and no read request is in the queue (unlike read queue callbacks, this
		202	callback will only be called when at least one octet of data is in the
		203	read buffer).
		204
		205	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		206	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		207	must not enlarge or modify the read buffer, you can only remove data at
		208	the beginning from it.
		209
		210	You can also call C<< ->push_read (...) >> or any other function that
		211	modifies the read queue. Or do both. Or ...
		212
		213	When an EOF condition is detected, AnyEvent::Handle will first try to
		214	feed all the remaining data to the queued callbacks and C<on_read> before
		215	calling the C<on_eof> callback. If no progress can be made, then a fatal
		216	error will be raised (with C<$!> set to C<EPIPE>).
		217
		218	Note that, unlike requests in the read queue, an C<on_read> callback
		219	doesn't mean you I<require> some data: if there is an EOF and there
		220	are outstanding read requests then an error will be flagged. With an
		221	C<on_read> callback, the C<on_eof> callback will be invoked.
		222
		223	=item on_eof => $cb->($handle)
		224
		225	Set the callback to be called when an end-of-file condition is detected,
		226	i.e. in the case of a socket, when the other side has closed the
		227	connection cleanly, and there are no outstanding read requests in the
		228	queue (if there are read requests, then an EOF counts as an unexpected
		229	connection close and will be flagged as an error).
		230
		231	For sockets, this just means that the other side has stopped sending data,
		232	you can still try to write data, and, in fact, one can return from the EOF
		233	callback and continue writing data, as only the read part has been shut
		234	down.
		235
		236	If an EOF condition has been detected but no C<on_eof> callback has been
		237	set, then a fatal error will be raised with C<$!> set to <0>.
		238
		239	=item on_drain => $cb->($handle)
		240
		241	This sets the callback that is called once when the write buffer becomes
		242	empty (and immediately when the handle object is created).
		243
		244	To append to the write buffer, use the C<< ->push_write >> method.
		245
		246	This callback is useful when you don't want to put all of your write data
		247	into the queue at once, for example, when you want to write the contents
		248	of some file to the socket you might not want to read the whole file into
		249	memory and push it into the queue, but instead only read more data from
		250	the file when the write queue becomes empty.
		251
		252	=item timeout => $fractional_seconds
		253
		254	=item rtimeout => $fractional_seconds
		255
		256	=item wtimeout => $fractional_seconds
		257
		258	If non-zero, then these enables an "inactivity" timeout: whenever this
		259	many seconds pass without a successful read or write on the underlying
		260	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		261	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		262	error will be raised).
		263
		264	There are three variants of the timeouts that work independently of each
		265	other, for both read and write (triggered when nothing was read I<OR>
		266	written), just read (triggered when nothing was read), and just write:
		267	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		268	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		269	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		270
		271	Note that timeout processing is active even when you do not have any
		272	outstanding read or write requests: If you plan to keep the connection
		273	idle then you should disable the timeout temporarily or ignore the
		274	timeout in the corresponding C<on_timeout> callback, in which case
		275	AnyEvent::Handle will simply restart the timeout.
		276
		277	Zero (the default) disables the corresponding timeout.
		278
		279	=item on_timeout => $cb->($handle)
		280
		281	=item on_rtimeout => $cb->($handle)
		282
		283	=item on_wtimeout => $cb->($handle)
		284
		285	Called whenever the inactivity timeout passes. If you return from this
		286	callback, then the timeout will be reset as if some activity had happened,
		287	so this condition is not fatal in any way.
		288
		289	=item rbuf_max => <bytes>
		290
		291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		292	when the read buffer ever (strictly) exceeds this size. This is useful to
		293	avoid some forms of denial-of-service attacks.
		294
		295	For example, a server accepting connections from untrusted sources should
		296	be configured to accept only so-and-so much data that it cannot act on
		297	(for example, when expecting a line, an attacker could send an unlimited
		298	amount of data without a callback ever being called as long as the line
		299	isn't finished).
		300
		301	=item wbuf_max => <bytes>
		302
		303	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		304	when the write buffer ever (strictly) exceeds this size. This is useful to
		305	avoid some forms of denial-of-service attacks.
		306
		307	Although the units of this parameter is bytes, this is the I<raw> number
		308	of bytes not yet accepted by the kernel. This can make a difference when
		309	you e.g. use TLS, as TLS typically makes your write data larger (but it
		310	can also make it smaller due to compression).
		311
		312	As an example of when this limit is useful, take a chat server that sends
		313	chat messages to a client. If the client does not read those in a timely
		314	manner then the send buffer in the server would grow unbounded.
		315
		316	=item autocork => <boolean>
		317
		318	When disabled (the default), C<push_write> will try to immediately
		319	write the data to the handle if possible. This avoids having to register
		320	a write watcher and wait for the next event loop iteration, but can
		321	be inefficient if you write multiple small chunks (on the wire, this
		322	disadvantage is usually avoided by your kernel's nagle algorithm, see
		323	C<no_delay>, but this option can save costly syscalls).
		324
		325	When enabled, writes will always be queued till the next event loop
		326	iteration. This is efficient when you do many small writes per iteration,
		327	but less efficient when you do a single write only per iteration (or when
		328	the write buffer often is full). It also increases write latency.
		329
		330	=item no_delay => <boolean>
		331
		332	When doing small writes on sockets, your operating system kernel might
		333	wait a bit for more data before actually sending it out. This is called
		334	the Nagle algorithm, and usually it is beneficial.
		335
		336	In some situations you want as low a delay as possible, which can be
		337	accomplishd by setting this option to a true value.
		338
		339	The default is your operating system's default behaviour (most likely
		340	enabled). This option explicitly enables or disables it, if possible.
		341
		342	=item keepalive => <boolean>
		343
		344	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		345	normally, TCP connections have no time-out once established, so TCP
		346	connections, once established, can stay alive forever even when the other
		347	side has long gone. TCP keepalives are a cheap way to take down long-lived
		348	TCP connections when the other side becomes unreachable. While the default
		349	is OS-dependent, TCP keepalives usually kick in after around two hours,
		350	and, if the other side doesn't reply, take down the TCP connection some 10
		351	to 15 minutes later.
		352
		353	It is harmless to specify this option for file handles that do not support
		354	keepalives, and enabling it on connections that are potentially long-lived
		355	is usually a good idea.
		356
		357	=item oobinline => <boolean>
		358
		359	BSD majorly fucked up the implementation of TCP urgent data. The result
		360	is that almost no OS implements TCP according to the specs, and every OS
		361	implements it slightly differently.
		362
		363	If you want to handle TCP urgent data, then setting this flag (the default
		364	is enabled) gives you the most portable way of getting urgent data, by
		365	putting it into the stream.
		366
		367	Since BSD emulation of OOB data on top of TCP's urgent data can have
		368	security implications, AnyEvent::Handle sets this flag automatically
		369	unless explicitly specified. Note that setting this flag after
		370	establishing a connection I<may> be a bit too late (data loss could
		371	already have occured on BSD systems), but at least it will protect you
		372	from most attacks.
		373
		374	=item read_size => <bytes>
		375
		376	The initial read block size, the number of bytes this module will try
		377	to read during each loop iteration. Each handle object will consume
		378	at least this amount of memory for the read buffer as well, so when
		379	handling many connections watch out for memory requirements). See also
		380	C<max_read_size>. Default: C<2048>.
		381
		382	=item max_read_size => <bytes>
		383
		384	The maximum read buffer size used by the dynamic adjustment
		385	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		386	one go it will double C<read_size> up to the maximum given by this
		387	option. Default: C<131072> or C<read_size>, whichever is higher.
		388
		389	=item low_water_mark => <bytes>
		390
		391	Sets the number of bytes (default: C<0>) that make up an "empty" write
		392	buffer: If the buffer reaches this size or gets even samller it is
		393	considered empty.
		394
		395	Sometimes it can be beneficial (for performance reasons) to add data to
		396	the write buffer before it is fully drained, but this is a rare case, as
		397	the operating system kernel usually buffers data as well, so the default
		398	is good in almost all cases.
		399
		400	=item linger => <seconds>
		401
		402	If this is non-zero (default: C<3600>), the destructor of the
		403	AnyEvent::Handle object will check whether there is still outstanding
		404	write data and will install a watcher that will write this data to the
		405	socket. No errors will be reported (this mostly matches how the operating
		406	system treats outstanding data at socket close time).
		407
		408	This will not work for partial TLS data that could not be encoded
		409	yet. This data will be lost. Calling the C<stoptls> method in time might
		410	help.
		411
		412	=item peername => $string
		413
		414	A string used to identify the remote site - usually the DNS hostname
		415	(I<not> IDN!) used to create the connection, rarely the IP address.
		416
		417	Apart from being useful in error messages, this string is also used in TLS
		418	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		419	verification will be skipped when C<peername> is not specified or is
		420	C<undef>.
		421
		422	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		423
		424	When this parameter is given, it enables TLS (SSL) mode, that means
		425	AnyEvent will start a TLS handshake as soon as the connection has been
		426	established and will transparently encrypt/decrypt data afterwards.
		427
		428	All TLS protocol errors will be signalled as C<EPROTO>, with an
		429	appropriate error message.
		430
		431	TLS mode requires Net::SSLeay to be installed (it will be loaded
		432	automatically when you try to create a TLS handle): this module doesn't
		433	have a dependency on that module, so if your module requires it, you have
		434	to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
		435	old, you get an C<EPROTO> error.
		436
		437	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		438	C<accept>, and for the TLS client side of a connection, use C<connect>
		439	mode.
		440
		441	You can also provide your own TLS connection object, but you have
		442	to make sure that you call either C<Net::SSLeay::set_connect_state>
		443	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		444	AnyEvent::Handle. Also, this module will take ownership of this connection
		445	object.
		446
		447	At some future point, AnyEvent::Handle might switch to another TLS
		448	implementation, then the option to use your own session object will go
		449	away.
		450
		451	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		452	passing in the wrong integer will lead to certain crash. This most often
		453	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		454	segmentation fault.
		455
		456	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
		457
		458	=item tls_ctx => $anyevent_tls
		459
		460	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		461	(unless a connection object was specified directly). If this
		462	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		463	C<AnyEvent::Handle::TLS_CTX>.
		464
		465	Instead of an object, you can also specify a hash reference with C<< key
		466	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		467	new TLS context object.
		468
		469	=item on_starttls => $cb->($handle, $success[, $error_message])
		470
		471	This callback will be invoked when the TLS/SSL handshake has finished. If
		472	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		473	(C<on_stoptls> will not be called in this case).
		474
		475	The session in C<< $handle->{tls} >> can still be examined in this
		476	callback, even when the handshake was not successful.
		477
		478	TLS handshake failures will not cause C<on_error> to be invoked when this
		479	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		480
		481	Without this callback, handshake failures lead to C<on_error> being
		482	called as usual.
		483
		484	Note that you cannot just call C<starttls> again in this callback. If you
		485	need to do that, start an zero-second timer instead whose callback can
		486	then call C<< ->starttls >> again.
		487
		488	=item on_stoptls => $cb->($handle)
		489
		490	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		491	set, then it will be invoked after freeing the TLS session. If it is not,
		492	then a TLS shutdown condition will be treated like a normal EOF condition
		493	on the handle.
		494
		495	The session in C<< $handle->{tls} >> can still be examined in this
		496	callback.
		497
		498	This callback will only be called on TLS shutdowns, not when the
		499	underlying handle signals EOF.
		500
		501	=item json => L<JSON>, L<JSON::PP> or L<JSON::XS> object
		502
		503	This is the json coder object used by the C<json> read and write types.
		504
		505	If you don't supply it, then AnyEvent::Handle will create and use a
		506	suitable one (on demand), which will write and expect UTF-8 encoded
		507	JSON texts (either using L<JSON::XS> or L<JSON>). The written texts are
		508	guaranteed not to contain any newline character.
		509
		510	For security reasons, this encoder will likely I<not> handle numbers and
		511	strings, only arrays and objects/hashes. The reason is that originally
		512	JSON was self-delimited, but Dougles Crockford thought it was a splendid
		513	idea to redefine JSON incompatibly, so this is no longer true.
		514
		515	For protocols that used back-to-back JSON texts, this might lead to
		516	run-ins, where two or more JSON texts will be interpreted as one JSON
		517	text.
		518
		519	For this reason, if the default encoder uses L<JSON::XS>, it will default
		520	to not allowing anything but arrays and objects/hashes, at least for the
		521	forseeable future (it will change at some point). This might or might not
		522	be true for the L<JSON> module, so this might cause a security issue.
		523
		524	If you depend on either behaviour, you should create your own json object
		525	and pass it in explicitly.
		526
		527	=item cbor => L<CBOR::XS> object
		528
		529	This is the cbor coder object used by the C<cbor> read and write types.
		530
		531	If you don't supply it, then AnyEvent::Handle will create and use a
		532	suitable one (on demand), which will write CBOR without using extensions,
		533	if possible.
		534
		535	Note that you are responsible to depend on the L<CBOR::XS> module if you
		536	want to use this functionality, as AnyEvent does not have a dependency on
		537	it itself.
		538
		539	=back
		540
		541	=cut
		542
		543	sub new {
		544	my $class = shift;
		545	my $self = bless { @_ }, $class;
		546
		547	if ($self->{fh}) {
		548	$self->_start;
		549	return unless $self->{fh}; # could be gone by now
		550
		551	} elsif ($self->{connect}) {
		552	require AnyEvent::Socket;
		553
		554	$self->{peername} = $self->{connect}[0]
		555	unless exists $self->{peername};
		556
		557	$self->{_skip_drain_rbuf} = 1;
		558
		559	{
		560	Scalar::Util::weaken (my $self = $self);
		561
		562	$self->{_connect} =
		563	AnyEvent::Socket::tcp_connect (
		564	$self->{connect}[0],
		565	$self->{connect}[1],
		566	sub {
		567	my ($fh, $host, $port, $retry) = @_;
		568
		569	delete $self->{_connect}; # no longer needed
		570
		571	if ($fh) {
		572	$self->{fh} = $fh;
		573
		574	delete $self->{_skip_drain_rbuf};
		575	$self->_start;
		576
		577	$self->{on_connect}
		578	and $self->{on_connect}($self, $host, $port, sub {
		579	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		580	$self->{_skip_drain_rbuf} = 1;
		581	&$retry;
		582	});
		583
		584	} else {
		585	if ($self->{on_connect_error}) {
		586	$self->{on_connect_error}($self, "$!");
		587	$self->destroy if $self;
		588	} else {
		589	$self->_error ($!, 1);
		590	}
		591	}
		592	},
		593	sub {
		594	local $self->{fh} = $_[0];
		595
		596	$self->{on_prepare}
		597	? $self->{on_prepare}->($self)
		598	: ()
		599	}
		600	);
		601	}
		602
		603	} else {
		604	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		605	}
		606
		607	$self
		608	}
		609
		610	sub _start {
		611	my ($self) = @_;
		612
		613	# too many clueless people try to use udp and similar sockets
		614	# with AnyEvent::Handle, do them a favour.
		615	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		616	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		617	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
		618
		619	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		620
		621	$self->{_activity} =
		622	$self->{_ractivity} =
		623	$self->{_wactivity} = AE::now;
		624
		625	$self->{read_size} ||= 2048;
		626	$self->{max_read_size} = $self->{read_size}
		627	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		628
		629	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		630	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		631	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		632
		633	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		634	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		635
		636	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		637
		638	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		639	if $self->{tls};
		640
		641	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
		642
		643	$self->start_read
		644	if $self->{on_read} || @{ $self->{_queue} };
		645
		646	$self->_drain_wbuf;
		647	}
		648
		649	sub _error {
		650	my ($self, $errno, $fatal, $message) = @_;
		651
		652	$! = $errno;
		653	$message ||= "$!";
		654
		655	if ($self->{on_error}) {
		656	$self->{on_error}($self, $fatal, $message);
		657	$self->destroy if $fatal;
		658	} elsif ($self->{fh} || $self->{connect}) {
		659	$self->destroy;
		660	Carp::croak "AnyEvent::Handle uncaught error: $message";
		661	}
		662	}
		663
		664	=item $fh = $handle->fh
		665
		666	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		667
		668	=cut
		669
		670	sub fh { $_[0]{fh} }
		671
		672	=item $handle->on_error ($cb)
		673
		674	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		675
		676	=cut
		677
		678	sub on_error {
		679	$_[0]{on_error} = $_[1];
		680	}
		681
		682	=item $handle->on_eof ($cb)
		683
		684	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		685
		686	=cut
		687
		688	sub on_eof {
		689	$_[0]{on_eof} = $_[1];
		690	}
		691
		692	=item $handle->on_timeout ($cb)
		693
		694	=item $handle->on_rtimeout ($cb)
		695
		696	=item $handle->on_wtimeout ($cb)
		697
		698	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		699	callback, or disables the callback (but not the timeout) if C<$cb> =
		700	C<undef>. See the C<timeout> constructor argument and method.
		701
		702	=cut
		703
		704	# see below
		705
		706	=item $handle->autocork ($boolean)
		707
		708	Enables or disables the current autocork behaviour (see C<autocork>
		709	constructor argument). Changes will only take effect on the next write.
		710
		711	=cut
		712
		713	sub autocork {
		714	$_[0]{autocork} = $_[1];
		715	}
		716
		717	=item $handle->no_delay ($boolean)
		718
		719	Enables or disables the C<no_delay> setting (see constructor argument of
		720	the same name for details).
		721
		722	=cut
		723
		724	sub no_delay {
		725	$_[0]{no_delay} = $_[1];
		726
		727	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		728	if $_[0]{fh};
		729	}
		730
		731	=item $handle->keepalive ($boolean)
		732
		733	Enables or disables the C<keepalive> setting (see constructor argument of
		734	the same name for details).
		735
		736	=cut
		737
		738	sub keepalive {
		739	$_[0]{keepalive} = $_[1];
		740
		741	eval {
		742	local $SIG{__DIE__};
		743	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		744	if $_[0]{fh};
		745	};
		746	}
		747
		748	=item $handle->oobinline ($boolean)
		749
		750	Enables or disables the C<oobinline> setting (see constructor argument of
		751	the same name for details).
		752
		753	=cut
		754
		755	sub oobinline {
		756	$_[0]{oobinline} = $_[1];
		757
		758	eval {
		759	local $SIG{__DIE__};
		760	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		761	if $_[0]{fh};
		762	};
		763	}
		764
		765	=item $handle->keepalive ($boolean)
		766
		767	Enables or disables the C<keepalive> setting (see constructor argument of
		768	the same name for details).
		769
		770	=cut
		771
		772	sub keepalive {
		773	$_[0]{keepalive} = $_[1];
		774
		775	eval {
		776	local $SIG{__DIE__};
		777	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		778	if $_[0]{fh};
		779	};
		780	}
		781
		782	=item $handle->on_starttls ($cb)
		783
		784	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		785
		786	=cut
		787
		788	sub on_starttls {
		789	$_[0]{on_starttls} = $_[1];
		790	}
		791
		792	=item $handle->on_stoptls ($cb)
		793
		794	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		795
		796	=cut
		797
		798	sub on_stoptls {
		799	$_[0]{on_stoptls} = $_[1];
		800	}
		801
		802	=item $handle->rbuf_max ($max_octets)
		803
		804	Configures the C<rbuf_max> setting (C<undef> disables it).
		805
		806	=item $handle->wbuf_max ($max_octets)
		807
		808	Configures the C<wbuf_max> setting (C<undef> disables it).
		809
		810	=cut
		811
		812	sub rbuf_max {
		813	$_[0]{rbuf_max} = $_[1];
		814	}
		815
		816	sub wbuf_max {
		817	$_[0]{wbuf_max} = $_[1];
		818	}
		819
		820	#############################################################################
		821
		822	=item $handle->timeout ($seconds)
		823
		824	=item $handle->rtimeout ($seconds)
		825
		826	=item $handle->wtimeout ($seconds)
		827
		828	Configures (or disables) the inactivity timeout.
		829
		830	The timeout will be checked instantly, so this method might destroy the
		831	handle before it returns.
		832
		833	=item $handle->timeout_reset
		834
		835	=item $handle->rtimeout_reset
		836
		837	=item $handle->wtimeout_reset
		838
		839	Reset the activity timeout, as if data was received or sent.
		840
		841	These methods are cheap to call.
		842
		843	=cut
		844
		845	for my $dir ("", "r", "w") {
		846	my $timeout = "${dir}timeout";
		847	my $tw = "_${dir}tw";
		848	my $on_timeout = "on_${dir}timeout";
		849	my $activity = "_${dir}activity";
		850	my $cb;
		851
		852	*$on_timeout = sub {
		853	$_[0]{$on_timeout} = $_[1];
		854	};
		855
		856	*$timeout = sub {
		857	my ($self, $new_value) = @_;
		858
		859	$new_value >= 0
		860	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		861
		862	$self->{$timeout} = $new_value;
		863	delete $self->{$tw}; &$cb;
		864	};
		865
		866	*{"${dir}timeout_reset"} = sub {
		867	$_[0]{$activity} = AE::now;
		868	};
		869
		870	# main workhorse:
		871	# reset the timeout watcher, as neccessary
		872	# also check for time-outs
		873	$cb = sub {
		874	my ($self) = @_;
		875
		876	if ($self->{$timeout} && $self->{fh}) {
		877	my $NOW = AE::now;
		878
		879	# when would the timeout trigger?
		880	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		881
		882	# now or in the past already?
		883	if ($after <= 0) {
		884	$self->{$activity} = $NOW;
		885
		886	if ($self->{$on_timeout}) {
		887	$self->{$on_timeout}($self);
		888	} else {
		889	$self->_error (Errno::ETIMEDOUT);
		890	}
		891
		892	# callback could have changed timeout value, optimise
		893	return unless $self->{$timeout};
		894
		895	# calculate new after
		896	$after = $self->{$timeout};
		897	}
		898
		899	Scalar::Util::weaken $self;
		900	return unless $self; # ->error could have destroyed $self
		901
		902	$self->{$tw} ||= AE::timer $after, 0, sub {
		903	delete $self->{$tw};
		904	$cb->($self);
36	chomp;	905	};
37	print "Line: $_";	906	} else {
		907	delete $self->{$tw};
		908	}
		909	}
		910	}
		911
		912	#############################################################################
		913
		914	=back
		915
		916	=head2 WRITE QUEUE
		917
		918	AnyEvent::Handle manages two queues per handle, one for writing and one
		919	for reading.
		920
		921	The write queue is very simple: you can add data to its end, and
		922	AnyEvent::Handle will automatically try to get rid of it for you.
		923
		924	When data could be written and the write buffer is shorter then the low
		925	water mark, the C<on_drain> callback will be invoked once.
		926
		927	=over 4
		928
		929	=item $handle->on_drain ($cb)
		930
		931	Sets the C<on_drain> callback or clears it (see the description of
		932	C<on_drain> in the constructor).
		933
		934	This method may invoke callbacks (and therefore the handle might be
		935	destroyed after it returns).
		936
		937	=cut
		938
		939	sub on_drain {
		940	my ($self, $cb) = @_;
		941
		942	$self->{on_drain} = $cb;
		943
		944	$cb->($self)
		945	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		946	}
		947
		948	=item $handle->push_write ($data)
		949
		950	Queues the given scalar to be written. You can push as much data as
		951	you want (only limited by the available memory and C<wbuf_max>), as
		952	C<AnyEvent::Handle> buffers it independently of the kernel.
		953
		954	This method may invoke callbacks (and therefore the handle might be
		955	destroyed after it returns).
		956
		957	=cut
		958
		959	sub _drain_wbuf {
		960	my ($self) = @_;
		961
		962	if (!$self->{_ww} && length $self->{wbuf}) {
		963
		964	Scalar::Util::weaken $self;
		965
		966	my $cb = sub {
		967	my $len = syswrite $self->{fh}, $self->{wbuf};
		968
		969	if (defined $len) {
		970	substr $self->{wbuf}, 0, $len, "";
		971
		972	$self->{_activity} = $self->{_wactivity} = AE::now;
		973
		974	$self->{on_drain}($self)
		975	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		976	&& $self->{on_drain};
		977
		978	delete $self->{_ww} unless length $self->{wbuf};
		979	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		980	$self->_error ($!, 1);
		981	}
		982	};
		983
		984	# try to write data immediately
		985	$cb->() unless $self->{autocork};
		986
		987	# if still data left in wbuf, we need to poll
		988	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		989	if length $self->{wbuf};
		990
		991	if (
		992	defined $self->{wbuf_max}
		993	&& $self->{wbuf_max} < length $self->{wbuf}
		994	) {
		995	$self->_error (Errno::ENOSPC, 1), return;
		996	}
		997	};
		998	}
		999
		1000	our %WH;
		1001
		1002	# deprecated
		1003	sub register_write_type($$) {
		1004	$WH{$_[0]} = $_[1];
		1005	}
		1006
		1007	sub push_write {
		1008	my $self = shift;
		1009
		1010	if (@_ > 1) {
		1011	my $type = shift;
		1012
		1013	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		1014	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		1015	->($self, @_);
		1016	}
		1017
		1018	# we downgrade here to avoid hard-to-track-down bugs,
		1019	# and diagnose the problem earlier and better.
		1020
		1021	if ($self->{tls}) {
		1022	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		1023	&_dotls ($self) if $self->{fh};
		1024	} else {
		1025	utf8::downgrade $self->{wbuf} .= $_[0];
		1026	$self->_drain_wbuf if $self->{fh};
		1027	}
		1028	}
		1029
		1030	=item $handle->push_write (type => @args)
		1031
		1032	Instead of formatting your data yourself, you can also let this module
		1033	do the job by specifying a type and type-specific arguments. You
		1034	can also specify the (fully qualified) name of a package, in which
		1035	case AnyEvent tries to load the package and then expects to find the
		1036	C<anyevent_write_type> function inside (see "custom write types", below).
		1037
		1038	Predefined types are (if you have ideas for additional types, feel free to
		1039	drop by and tell us):
		1040
		1041	=over 4
		1042
		1043	=item netstring => $string
		1044
		1045	Formats the given value as netstring
		1046	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		1047
		1048	=cut
		1049
		1050	register_write_type netstring => sub {
		1051	my ($self, $string) = @_;
		1052
		1053	(length $string) . ":$string,"
		1054	};
		1055
		1056	=item packstring => $format, $data
		1057
		1058	An octet string prefixed with an encoded length. The encoding C<$format>
		1059	uses the same format as a Perl C<pack> format, but must specify a single
		1060	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1061	optional C<!>, C<< < >> or C<< > >> modifier).
		1062
		1063	=cut
		1064
		1065	register_write_type packstring => sub {
		1066	my ($self, $format, $string) = @_;
		1067
		1068	pack "$format/a*", $string
		1069	};
		1070
		1071	=item json => $array_or_hashref
		1072
		1073	Encodes the given hash or array reference into a JSON object. Unless you
		1074	provide your own JSON object, this means it will be encoded to JSON text
		1075	in UTF-8.
		1076
		1077	The default encoder might or might not handle every type of JSON value -
		1078	it might be limited to arrays and objects for security reasons. See the
		1079	C<json> constructor attribute for more details.
		1080
		1081	JSON objects (and arrays) are self-delimiting, so if you only use arrays
		1082	and hashes, you can write JSON at one end of a handle and read them at the
		1083	other end without using any additional framing.
		1084
		1085	The JSON text generated by the default encoder is guaranteed not to
		1086	contain any newlines: While this module doesn't need delimiters after or
		1087	between JSON texts to be able to read them, many other languages depend on
		1088	them.
		1089
		1090	A simple RPC protocol that interoperates easily with other languages is
		1091	to send JSON arrays (or objects, although arrays are usually the better
		1092	choice as they mimic how function argument passing works) and a newline
		1093	after each JSON text:
		1094
		1095	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1096	$handle->push_write ("\012");
		1097
		1098	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1099	rely on the fact that the newline will be skipped as leading whitespace:
		1100
		1101	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1102
		1103	Other languages could read single lines terminated by a newline and pass
		1104	this line into their JSON decoder of choice.
		1105
		1106	=item cbor => $perl_scalar
		1107
		1108	Encodes the given scalar into a CBOR value. Unless you provide your own
		1109	L<CBOR::XS> object, this means it will be encoded to a CBOR string not
		1110	using any extensions, if possible.
		1111
		1112	CBOR values are self-delimiting, so you can write CBOR at one end of
		1113	a handle and read them at the other end without using any additional
		1114	framing.
		1115
		1116	A simple nd very very fast RPC protocol that interoperates with
		1117	other languages is to send CBOR and receive CBOR values (arrays are
		1118	recommended):
		1119
		1120	$handle->push_write (cbor => ["method", "arg1", "arg2"]); # whatever
		1121
		1122	An AnyEvent::Handle receiver would simply use the C<cbor> read type:
		1123
		1124	$handle->push_read (cbor => sub { my $array = $_[1]; ... });
		1125
		1126	=cut
		1127
		1128	sub json_coder() {
		1129	eval { require JSON::XS; JSON::XS->new->utf8 }
		1130	|| do { require JSON::PP; JSON::PP->new->utf8 }
		1131	}
		1132
		1133	register_write_type json => sub {
		1134	my ($self, $ref) = @_;
		1135
		1136	($self->{json} ||= json_coder)
		1137	->encode ($ref)
		1138	};
		1139
		1140	sub cbor_coder() {
		1141	require CBOR::XS;
		1142	CBOR::XS->new
		1143	}
		1144
		1145	register_write_type cbor => sub {
		1146	my ($self, $scalar) = @_;
		1147
		1148	($self->{cbor} ||= cbor_coder)
		1149	->encode ($scalar)
		1150	};
		1151
		1152	=item storable => $reference
		1153
		1154	Freezes the given reference using L<Storable> and writes it to the
		1155	handle. Uses the C<nfreeze> format.
		1156
		1157	=cut
		1158
		1159	register_write_type storable => sub {
		1160	my ($self, $ref) = @_;
		1161
		1162	require Storable unless $Storable::VERSION;
		1163
		1164	pack "w/a*", Storable::nfreeze ($ref)
		1165	};
		1166
		1167	=back
		1168
		1169	=item $handle->push_shutdown
		1170
		1171	Sometimes you know you want to close the socket after writing your data
		1172	before it was actually written. One way to do that is to replace your
		1173	C<on_drain> handler by a callback that shuts down the socket (and set
		1174	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1175	replaces the C<on_drain> callback with:
		1176
		1177	sub { shutdown $_[0]{fh}, 1 }
		1178
		1179	This simply shuts down the write side and signals an EOF condition to the
		1180	the peer.
		1181
		1182	You can rely on the normal read queue and C<on_eof> handling
		1183	afterwards. This is the cleanest way to close a connection.
		1184
		1185	This method may invoke callbacks (and therefore the handle might be
		1186	destroyed after it returns).
		1187
		1188	=cut
		1189
		1190	sub push_shutdown {
		1191	my ($self) = @_;
		1192
		1193	delete $self->{low_water_mark};
		1194	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1195	}
		1196
		1197	=item custom write types - Package::anyevent_write_type $handle, @args
		1198
		1199	Instead of one of the predefined types, you can also specify the name of
		1200	a package. AnyEvent will try to load the package and then expects to find
		1201	a function named C<anyevent_write_type> inside. If it isn't found, it
		1202	progressively tries to load the parent package until it either finds the
		1203	function (good) or runs out of packages (bad).
		1204
		1205	Whenever the given C<type> is used, C<push_write> will the function with
		1206	the handle object and the remaining arguments.
		1207
		1208	The function is supposed to return a single octet string that will be
		1209	appended to the write buffer, so you can mentally treat this function as a
		1210	"arguments to on-the-wire-format" converter.
		1211
		1212	Example: implement a custom write type C<join> that joins the remaining
		1213	arguments using the first one.
		1214
		1215	$handle->push_write (My::Type => " ", 1,2,3);
		1216
		1217	# uses the following package, which can be defined in the "My::Type" or in
		1218	# the "My" modules to be auto-loaded, or just about anywhere when the
		1219	# My::Type::anyevent_write_type is defined before invoking it.
		1220
		1221	package My::Type;
		1222
		1223	sub anyevent_write_type {
		1224	my ($handle, $delim, @args) = @_;
		1225
		1226	join $delim, @args
		1227	}
		1228
		1229	=cut
		1230
		1231	#############################################################################
		1232
		1233	=back
		1234
		1235	=head2 READ QUEUE
		1236
		1237	AnyEvent::Handle manages two queues per handle, one for writing and one
		1238	for reading.
		1239
		1240	The read queue is more complex than the write queue. It can be used in two
		1241	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1242	a queue.
		1243
		1244	In the simple case, you just install an C<on_read> callback and whenever
		1245	new data arrives, it will be called. You can then remove some data (if
		1246	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
		1247	leave the data there if you want to accumulate more (e.g. when only a
		1248	partial message has been received so far), or change the read queue with
		1249	e.g. C<push_read>.
		1250
		1251	In the more complex case, you want to queue multiple callbacks. In this
		1252	case, AnyEvent::Handle will call the first queued callback each time new
		1253	data arrives (also the first time it is queued) and remove it when it has
		1254	done its job (see C<push_read>, below).
		1255
		1256	This way you can, for example, push three line-reads, followed by reading
		1257	a chunk of data, and AnyEvent::Handle will execute them in order.
		1258
		1259	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1260	the specified number of bytes which give an XML datagram.
		1261
		1262	# in the default state, expect some header bytes
		1263	$handle->on_read (sub {
		1264	# some data is here, now queue the length-header-read (4 octets)
		1265	shift->unshift_read (chunk => 4, sub {
		1266	# header arrived, decode
		1267	my $len = unpack "N", $_[1];
		1268
		1269	# now read the payload
		1270	shift->unshift_read (chunk => $len, sub {
		1271	my $xml = $_[1];
		1272	# handle xml
		1273	});
		1274	});
		1275	});
		1276
		1277	Example 2: Implement a client for a protocol that replies either with "OK"
		1278	and another line or "ERROR" for the first request that is sent, and 64
		1279	bytes for the second request. Due to the availability of a queue, we can
		1280	just pipeline sending both requests and manipulate the queue as necessary
		1281	in the callbacks.
		1282
		1283	When the first callback is called and sees an "OK" response, it will
		1284	C<unshift> another line-read. This line-read will be queued I<before> the
		1285	64-byte chunk callback.
		1286
		1287	# request one, returns either "OK + extra line" or "ERROR"
		1288	$handle->push_write ("request 1\015\012");
		1289
		1290	# we expect "ERROR" or "OK" as response, so push a line read
		1291	$handle->push_read (line => sub {
		1292	# if we got an "OK", we have to _prepend_ another line,
		1293	# so it will be read before the second request reads its 64 bytes
		1294	# which are already in the queue when this callback is called
		1295	# we don't do this in case we got an error
		1296	if ($_[1] eq "OK") {
		1297	$_[0]->unshift_read (line => sub {
		1298	my $response = $_[1];
		1299	...
		1300	});
38	}	1301	}
39	});	1302	});
40		1303
41	# or use the constructor to pass the callback:	1304	# request two, simply returns 64 octets
		1305	$handle->push_write ("request 2\015\012");
42		1306
43	my $ae_fh2 =	1307	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1308	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1309	my $response = $_[1];
46	on_eof => sub {	1310	...
47	$cv->broadcast;	1311	});
48	},	1312
49	on_readline => sub {	1313	=over 4
50	my ($ae_fh, @lines) = @_;	1314
51	for (@lines) {	1315	=cut
52	chomp;	1316
53	print "Line: $_";	1317	sub _drain_rbuf {
		1318	my ($self) = @_;
		1319
		1320	# avoid recursion
		1321	return if $self->{_skip_drain_rbuf};
		1322	local $self->{_skip_drain_rbuf} = 1;
		1323
		1324	while () {
		1325	# we need to use a separate tls read buffer, as we must not receive data while
		1326	# we are draining the buffer, and this can only happen with TLS.
		1327	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1328	if exists $self->{_tls_rbuf};
		1329
		1330	my $len = length $self->{rbuf};
		1331
		1332	if (my $cb = shift @{ $self->{_queue} }) {
		1333	unless ($cb->($self)) {
		1334	# no progress can be made
		1335	# (not enough data and no data forthcoming)
		1336	$self->_error (Errno::EPIPE, 1), return
		1337	if $self->{_eof};
		1338
		1339	unshift @{ $self->{_queue} }, $cb;
54	}	1340	last;
55	}	1341	}
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 separated 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}) {	1342	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1343	last unless $len;
122		1344
		1345	$self->{on_read}($self);
		1346
		1347	if (
		1348	$len == length $self->{rbuf} # if no data has been consumed
		1349	&& !@{ $self->{_queue} } # and the queue is still empty
		1350	&& $self->{on_read} # but we still have on_read
		1351	) {
		1352	# no further data will arrive
		1353	# so no progress can be made
		1354	$self->_error (Errno::EPIPE, 1), return
		1355	if $self->{_eof};
		1356
		1357	last; # more data might arrive
		1358	}
		1359	} else {
		1360	# read side becomes idle
		1361	delete $self->{_rw} unless $self->{tls};
		1362	last;
		1363	}
		1364	}
		1365
123	} elsif ($self->{on_eof}) {	1366	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1367	$self->{on_eof}
		1368	? $self->{on_eof}($self)
		1369	: $self->_error (0, 1, "Unexpected end-of-file");
125		1370
126	} elsif ($self->{on_error}) {	1371	return;
127	$self->on_eof ($self->{on_error});
128	}	1372	}
129		1373
130	return $self	1374	if (
131	}	1375	defined $self->{rbuf_max}
		1376	&& $self->{rbuf_max} < length $self->{rbuf}
		1377	) {
		1378	$self->_error (Errno::ENOSPC, 1), return;
		1379	}
132		1380
133	=item B<fh>	1381	# may need to restart read watcher
		1382	unless ($self->{_rw}) {
		1383	$self->start_read
		1384	if $self->{on_read} || @{ $self->{_queue} };
		1385	}
		1386	}
134		1387
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1388	=item $handle->on_read ($cb)
136		1389
137	=cut	1390	This replaces the currently set C<on_read> callback, or clears it (when
		1391	the new callback is C<undef>). See the description of C<on_read> in the
		1392	constructor.
138		1393
139	sub fh { $_[0]->{fh} }	1394	This method may invoke callbacks (and therefore the handle might be
140		1395	destroyed after it returns).
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		1396
149	=cut	1397	=cut
150		1398
151	sub on_read {	1399	sub on_read {
152	my ($self, $cb) = @_;	1400	my ($self, $cb) = @_;
		1401
153	$self->{on_read} = $cb;	1402	$self->{on_read} = $cb;
		1403	$self->_drain_rbuf if $cb;
		1404	}
154		1405
155	unless (defined $self->{on_read}) {	1406	=item $handle->rbuf
156	delete $self->{on_read_w};	1407
		1408	Returns the read buffer (as a modifiable lvalue). You can also access the
		1409	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1410	much faster, and no less clean).
		1411
		1412	The only operation allowed on the read buffer (apart from looking at it)
		1413	is removing data from its beginning. Otherwise modifying or appending to
		1414	it is not allowed and will lead to hard-to-track-down bugs.
		1415
		1416	NOTE: The read buffer should only be used or modified in the C<on_read>
		1417	callback or when C<push_read> or C<unshift_read> are used with a single
		1418	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1419	will manage the read buffer on their own.
		1420
		1421	=cut
		1422
		1423	sub rbuf : lvalue {
		1424	$_[0]{rbuf}
		1425	}
		1426
		1427	=item $handle->push_read ($cb)
		1428
		1429	=item $handle->unshift_read ($cb)
		1430
		1431	Append the given callback to the end of the queue (C<push_read>) or
		1432	prepend it (C<unshift_read>).
		1433
		1434	The callback is called each time some additional read data arrives.
		1435
		1436	It must check whether enough data is in the read buffer already.
		1437
		1438	If not enough data is available, it must return the empty list or a false
		1439	value, in which case it will be called repeatedly until enough data is
		1440	available (or an error condition is detected).
		1441
		1442	If enough data was available, then the callback must remove all data it is
		1443	interested in (which can be none at all) and return a true value. After returning
		1444	true, it will be removed from the queue.
		1445
		1446	These methods may invoke callbacks (and therefore the handle might be
		1447	destroyed after it returns).
		1448
		1449	=cut
		1450
		1451	our %RH;
		1452
		1453	sub register_read_type($$) {
		1454	$RH{$_[0]} = $_[1];
		1455	}
		1456
		1457	sub push_read {
		1458	my $self = shift;
		1459	my $cb = pop;
		1460
		1461	if (@_) {
		1462	my $type = shift;
		1463
		1464	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1465	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1466	->($self, $cb, @_);
		1467	}
		1468
		1469	push @{ $self->{_queue} }, $cb;
		1470	$self->_drain_rbuf;
		1471	}
		1472
		1473	sub unshift_read {
		1474	my $self = shift;
		1475	my $cb = pop;
		1476
		1477	if (@_) {
		1478	my $type = shift;
		1479
		1480	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1481	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
		1482	->($self, $cb, @_);
		1483	}
		1484
		1485	unshift @{ $self->{_queue} }, $cb;
		1486	$self->_drain_rbuf;
		1487	}
		1488
		1489	=item $handle->push_read (type => @args, $cb)
		1490
		1491	=item $handle->unshift_read (type => @args, $cb)
		1492
		1493	Instead of providing a callback that parses the data itself you can chose
		1494	between a number of predefined parsing formats, for chunks of data, lines
		1495	etc. You can also specify the (fully qualified) name of a package, in
		1496	which case AnyEvent tries to load the package and then expects to find the
		1497	C<anyevent_read_type> function inside (see "custom read types", below).
		1498
		1499	Predefined types are (if you have ideas for additional types, feel free to
		1500	drop by and tell us):
		1501
		1502	=over 4
		1503
		1504	=item chunk => $octets, $cb->($handle, $data)
		1505
		1506	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1507	data read to the callback. The callback will never be called with less
		1508	data.
		1509
		1510	Example: read 2 bytes.
		1511
		1512	$handle->push_read (chunk => 2, sub {
		1513	say "yay " . unpack "H*", $_[1];
		1514	});
		1515
		1516	=cut
		1517
		1518	register_read_type chunk => sub {
		1519	my ($self, $cb, $len) = @_;
		1520
		1521	sub {
		1522	$len <= length $_[0]{rbuf} or return;
		1523	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1524	1
		1525	}
		1526	};
		1527
		1528	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1529
		1530	The callback will be called only once a full line (including the end of
		1531	line marker, C<$eol>) has been read. This line (excluding the end of line
		1532	marker) will be passed to the callback as second argument (C<$line>), and
		1533	the end of line marker as the third argument (C<$eol>).
		1534
		1535	The end of line marker, C<$eol>, can be either a string, in which case it
		1536	will be interpreted as a fixed record end marker, or it can be a regex
		1537	object (e.g. created by C<qr>), in which case it is interpreted as a
		1538	regular expression.
		1539
		1540	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1541	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1542	protocols).
		1543
		1544	Partial lines at the end of the stream will never be returned, as they are
		1545	not marked by the end of line marker.
		1546
		1547	=cut
		1548
		1549	register_read_type line => sub {
		1550	my ($self, $cb, $eol) = @_;
		1551
		1552	if (@_ < 3) {
		1553	# this is faster then the generic code below
		1554	sub {
		1555	(my $pos = index $_[0]{rbuf}, "\012") >= 0
		1556	or return;
		1557
		1558	(my $str = substr $_[0]{rbuf}, 0, $pos + 1, "") =~ s/(\015?\012)\Z// or die;
		1559	$cb->($_[0], $str, "$1");
		1560	1
		1561	}
		1562	} else {
		1563	$eol = quotemeta $eol unless ref $eol;
		1564	$eol = qr|^(.*?)($eol)|s;
		1565
		1566	sub {
		1567	$_[0]{rbuf} =~ s/$eol// or return;
		1568
		1569	$cb->($_[0], "$1", "$2");
		1570	1
		1571	}
		1572	}
		1573	};
		1574
		1575	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1576
		1577	Makes a regex match against the regex object C<$accept> and returns
		1578	everything up to and including the match.
		1579
		1580	Example: read a single line terminated by '\n'.
		1581
		1582	$handle->push_read (regex => qr<\n>, sub { ... });
		1583
		1584	If C<$reject> is given and not undef, then it determines when the data is
		1585	to be rejected: it is matched against the data when the C<$accept> regex
		1586	does not match and generates an C<EBADMSG> error when it matches. This is
		1587	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1588	receive buffer overflow).
		1589
		1590	Example: expect a single decimal number followed by whitespace, reject
		1591	anything else (not the use of an anchor).
		1592
		1593	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1594
		1595	If C<$skip> is given and not C<undef>, then it will be matched against
		1596	the receive buffer when neither C<$accept> nor C<$reject> match,
		1597	and everything preceding and including the match will be accepted
		1598	unconditionally. This is useful to skip large amounts of data that you
		1599	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1600	have to start matching from the beginning. This is purely an optimisation
		1601	and is usually worth it only when you expect more than a few kilobytes.
		1602
		1603	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1604	expect the header to be very large (it isn't in practice, but...), we use
		1605	a skip regex to skip initial portions. The skip regex is tricky in that
		1606	it only accepts something not ending in either \015 or \012, as these are
		1607	required for the accept regex.
		1608
		1609	$handle->push_read (regex =>
		1610	qr<\015\012\015\012>,
		1611	undef, # no reject
		1612	qr<^.*[^\015\012]>,
		1613	sub { ... });
		1614
		1615	=cut
		1616
		1617	register_read_type regex => sub {
		1618	my ($self, $cb, $accept, $reject, $skip) = @_;
		1619
		1620	my $data;
		1621	my $rbuf = \$self->{rbuf};
		1622
		1623	sub {
		1624	# accept
		1625	if ($$rbuf =~ $accept) {
		1626	$data .= substr $$rbuf, 0, $+[0], "";
		1627	$cb->($_[0], $data);
		1628	return 1;
		1629	}
		1630
		1631	# reject
		1632	if ($reject && $$rbuf =~ $reject) {
		1633	$_[0]->_error (Errno::EBADMSG);
		1634	}
		1635
		1636	# skip
		1637	if ($skip && $$rbuf =~ $skip) {
		1638	$data .= substr $$rbuf, 0, $+[0], "";
		1639	}
		1640
		1641	()
		1642	}
		1643	};
		1644
		1645	=item netstring => $cb->($handle, $string)
		1646
		1647	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1648
		1649	Throws an error with C<$!> set to EBADMSG on format violations.
		1650
		1651	=cut
		1652
		1653	register_read_type netstring => sub {
		1654	my ($self, $cb) = @_;
		1655
		1656	sub {
		1657	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1658	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1659	$_[0]->_error (Errno::EBADMSG);
		1660	}
157	return;	1661	return;
		1662	}
		1663
		1664	my $len = $1;
		1665
		1666	$_[0]->unshift_read (chunk => $len, sub {
		1667	my $string = $_[1];
		1668	$_[0]->unshift_read (chunk => 1, sub {
		1669	if ($_[1] eq ",") {
		1670	$cb->($_[0], $string);
		1671	} else {
		1672	$_[0]->_error (Errno::EBADMSG);
		1673	}
		1674	});
		1675	});
		1676
		1677	1
		1678	}
		1679	};
		1680
		1681	=item packstring => $format, $cb->($handle, $string)
		1682
		1683	An octet string prefixed with an encoded length. The encoding C<$format>
		1684	uses the same format as a Perl C<pack> format, but must specify a single
		1685	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1686	optional C<!>, C<< < >> or C<< > >> modifier).
		1687
		1688	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1689	EPP uses a prefix of C<N> (4 octtes).
		1690
		1691	Example: read a block of data prefixed by its length in BER-encoded
		1692	format (very efficient).
		1693
		1694	$handle->push_read (packstring => "w", sub {
		1695	my ($handle, $data) = @_;
		1696	});
		1697
		1698	=cut
		1699
		1700	register_read_type packstring => sub {
		1701	my ($self, $cb, $format) = @_;
		1702
		1703	sub {
		1704	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1705	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1706	or return;
		1707
		1708	$format = length pack $format, $len;
		1709
		1710	# bypass unshift if we already have the remaining chunk
		1711	if ($format + $len <= length $_[0]{rbuf}) {
		1712	my $data = substr $_[0]{rbuf}, $format, $len;
		1713	substr $_[0]{rbuf}, 0, $format + $len, "";
		1714	$cb->($_[0], $data);
		1715	} else {
		1716	# remove prefix
		1717	substr $_[0]{rbuf}, 0, $format, "";
		1718
		1719	# read remaining chunk
		1720	$_[0]->unshift_read (chunk => $len, $cb);
		1721	}
		1722
		1723	1
		1724	}
		1725	};
		1726
		1727	=item json => $cb->($handle, $hash_or_arrayref)
		1728
		1729	Reads a JSON object or array, decodes it and passes it to the
		1730	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1731
		1732	If a C<json> object was passed to the constructor, then that will be
		1733	used for the final decode, otherwise it will create a L<JSON::XS> or
		1734	L<JSON::PP> coder object expecting UTF-8.
		1735
		1736	This read type uses the incremental parser available with JSON version
		1737	2.09 (and JSON::XS version 2.2) and above.
		1738
		1739	Since JSON texts are fully self-delimiting, the C<json> read and write
		1740	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1741	the C<json> write type description, above, for an actual example.
		1742
		1743	=cut
		1744
		1745	register_read_type json => sub {
		1746	my ($self, $cb) = @_;
		1747
		1748	my $json = $self->{json} ||= json_coder;
		1749
		1750	my $data;
		1751
		1752	sub {
		1753	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
		1754
		1755	if ($ref) {
		1756	$_[0]{rbuf} = $json->incr_text;
		1757	$json->incr_text = "";
		1758	$cb->($_[0], $ref);
		1759
		1760	1
		1761	} elsif ($@) {
		1762	# error case
		1763	$json->incr_skip;
		1764
		1765	$_[0]{rbuf} = $json->incr_text;
		1766	$json->incr_text = "";
		1767
		1768	$_[0]->_error (Errno::EBADMSG);
		1769
		1770	()
		1771	} else {
		1772	$_[0]{rbuf} = "";
		1773
		1774	()
		1775	}
		1776	}
		1777	};
		1778
		1779	=item cbor => $cb->($handle, $scalar)
		1780
		1781	Reads a CBOR value, decodes it and passes it to the callback. When a parse
		1782	error occurs, an C<EBADMSG> error will be raised.
		1783
		1784	If a L<CBOR::XS> object was passed to the constructor, then that will be
		1785	used for the final decode, otherwise it will create a CBOR coder without
		1786	enabling any options.
		1787
		1788	You have to provide a dependency to L<CBOR::XS> on your own: this module
		1789	will load the L<CBOR::XS> module, but AnyEvent does not depend on it
		1790	itself.
		1791
		1792	Since CBOR values are fully self-delimiting, the C<cbor> read and write
		1793	types are an ideal simple RPC protocol: just exchange CBOR datagrams. See
		1794	the C<cbor> write type description, above, for an actual example.
		1795
		1796	=cut
		1797
		1798	register_read_type cbor => sub {
		1799	my ($self, $cb) = @_;
		1800
		1801	my $cbor = $self->{cbor} ||= cbor_coder;
		1802
		1803	my $data;
		1804
		1805	sub {
		1806	my (@value) = eval { $cbor->incr_parse ($_[0]{rbuf}) };
		1807
		1808	if (@value) {
		1809	$cb->($_[0], @value);
		1810
		1811	1
		1812	} elsif ($@) {
		1813	# error case
		1814	$cbor->incr_reset;
		1815
		1816	$_[0]->_error (Errno::EBADMSG);
		1817
		1818	()
		1819	} else {
		1820	()
		1821	}
		1822	}
		1823	};
		1824
		1825	=item storable => $cb->($handle, $ref)
		1826
		1827	Deserialises a L<Storable> frozen representation as written by the
		1828	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1829	data).
		1830
		1831	Raises C<EBADMSG> error if the data could not be decoded.
		1832
		1833	=cut
		1834
		1835	register_read_type storable => sub {
		1836	my ($self, $cb) = @_;
		1837
		1838	require Storable unless $Storable::VERSION;
		1839
		1840	sub {
		1841	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1842	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1843	or return;
		1844
		1845	my $format = length pack "w", $len;
		1846
		1847	# bypass unshift if we already have the remaining chunk
		1848	if ($format + $len <= length $_[0]{rbuf}) {
		1849	my $data = substr $_[0]{rbuf}, $format, $len;
		1850	substr $_[0]{rbuf}, 0, $format + $len, "";
		1851
		1852	eval { $cb->($_[0], Storable::thaw ($data)); 1 }
		1853	or return $_[0]->_error (Errno::EBADMSG);
		1854	} else {
		1855	# remove prefix
		1856	substr $_[0]{rbuf}, 0, $format, "";
		1857
		1858	# read remaining chunk
		1859	$_[0]->unshift_read (chunk => $len, sub {
		1860	eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
		1861	or $_[0]->_error (Errno::EBADMSG);
		1862	});
		1863	}
		1864
		1865	1
		1866	}
		1867	};
		1868
		1869	=item tls_detect => $cb->($handle, $detect, $major, $minor)
		1870
		1871	Checks the input stream for a valid SSL or TLS handshake TLSPaintext
		1872	record without consuming anything. Only SSL version 3 or higher
		1873	is handled, up to the fictituous protocol 4.x (but both SSL3+ and
		1874	SSL2-compatible framing is supported).
		1875
		1876	If it detects that the input data is likely TLS, it calls the callback
		1877	with a true value for C<$detect> and the (on-wire) TLS version as second
		1878	and third argument (C<$major> is C<3>, and C<$minor> is 0..3 for SSL
		1879	3.0, TLS 1.0, 1.1 and 1.2, respectively). If it detects the input to
		1880	be definitely not TLS, it calls the callback with a false value for
		1881	C<$detect>.
		1882
		1883	The callback could use this information to decide whether or not to start
		1884	TLS negotiation.
		1885
		1886	In all cases the data read so far is passed to the following read
		1887	handlers.
		1888
		1889	Usually you want to use the C<tls_autostart> read type instead.
		1890
		1891	If you want to design a protocol that works in the presence of TLS
		1892	dtection, make sure that any non-TLS data doesn't start with the octet 22
		1893	(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
		1894	read type does are a bit more strict, but might losen in the future to
		1895	accomodate protocol changes.
		1896
		1897	This read type does not rely on L<AnyEvent::TLS> (and thus, not on
		1898	L<Net::SSLeay>).
		1899
		1900	=item tls_autostart => $tls[, $tls_ctx]
		1901
		1902	Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
		1903	to start tls by calling C<starttls> with the given arguments.
		1904
		1905	In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
		1906	been configured to accept, as servers do not normally send a handshake on
		1907	their own and ths cannot be detected in this way.
		1908
		1909	See C<tls_detect> above for more details.
		1910
		1911	Example: give the client a chance to start TLS before accepting a text
		1912	line.
		1913
		1914	$hdl->push_read (tls_detect => "accept");
		1915	$hdl->push_read (line => sub {
		1916	print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
		1917	});
		1918
		1919	=cut
		1920
		1921	register_read_type tls_detect => sub {
		1922	my ($self, $cb) = @_;
		1923
		1924	sub {
		1925	# this regex matches a full or partial tls record
		1926	if (
		1927	# ssl3+: type(22=handshake) major(=3) minor(any) length_hi
		1928	$self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
		1929	# ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
		1930	or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
		1931	) {
		1932	return if 3 != length $1; # partial match, can't decide yet
		1933
		1934	# full match, valid TLS record
		1935	my ($major, $minor) = unpack "CC", $1;
		1936	$cb->($self, "accept", $major + $minor * 0.1);
		1937	} else {
		1938	# mismatch == guaranteed not TLS
		1939	$cb->($self, undef);
		1940	}
		1941
		1942	1
		1943	}
		1944	};
		1945
		1946	register_read_type tls_autostart => sub {
		1947	my ($self, @tls) = @_;
		1948
		1949	$RH{tls_detect}($self, sub {
		1950	return unless $_[1];
		1951	$_[0]->starttls (@tls);
158	}	1952	})
159		1953	};
160	$self->{on_read_w} =	1954
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1955	=back
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1956
163	my $rbuf_len = length $self->{rbuf};	1957	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
164	my $l;	1958
		1959	Instead of one of the predefined types, you can also specify the name
		1960	of a package. AnyEvent will try to load the package and then expects to
		1961	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1962	progressively tries to load the parent package until it either finds the
		1963	function (good) or runs out of packages (bad).
		1964
		1965	Whenever this type is used, C<push_read> will invoke the function with the
		1966	handle object, the original callback and the remaining arguments.
		1967
		1968	The function is supposed to return a callback (usually a closure) that
		1969	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1970	mentally treat the function as a "configurable read type to read callback"
		1971	converter.
		1972
		1973	It should invoke the original callback when it is done reading (remember
		1974	to pass C<$handle> as first argument as all other callbacks do that,
		1975	although there is no strict requirement on this).
		1976
		1977	For examples, see the source of this module (F<perldoc -m
		1978	AnyEvent::Handle>, search for C<register_read_type>)).
		1979
		1980	=item $handle->stop_read
		1981
		1982	=item $handle->start_read
		1983
		1984	In rare cases you actually do not want to read anything from the
		1985	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1986	any queued callbacks will be executed then. To start reading again, call
		1987	C<start_read>.
		1988
		1989	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1990	you change the C<on_read> callback or push/unshift a read callback, and it
		1991	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1992	there are any read requests in the queue.
		1993
		1994	In older versions of this module (<= 5.3), these methods had no effect,
		1995	as TLS does not support half-duplex connections. In current versions they
		1996	work as expected, as this behaviour is required to avoid certain resource
		1997	attacks, where the program would be forced to read (and buffer) arbitrary
		1998	amounts of data before being able to send some data. The drawback is that
		1999	some readings of the the SSL/TLS specifications basically require this
		2000	attack to be working, as SSL/TLS implementations might stall sending data
		2001	during a rehandshake.
		2002
		2003	As a guideline, during the initial handshake, you should not stop reading,
		2004	and as a client, it might cause problems, depending on your application.
		2005
		2006	=cut
		2007
		2008	sub stop_read {
		2009	my ($self) = @_;
		2010
		2011	delete $self->{_rw};
		2012	}
		2013
		2014	sub start_read {
		2015	my ($self) = @_;
		2016
		2017	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		2018	Scalar::Util::weaken $self;
		2019
		2020	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		2021	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		2022	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
		2023
		2024	if ($len > 0) {
		2025	$self->{_activity} = $self->{_ractivity} = AE::now;
		2026
		2027	if ($self->{tls}) {
		2028	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		2029
		2030	&_dotls ($self);
		2031	} else {
		2032	$self->_drain_rbuf;
		2033	}
		2034
165	if (defined $self->{read_size}) {	2035	if ($len == $self->{read_size}) {
166	$l = sysread $self->{fh}, $self->{rbuf},	2036	$self->{read_size} *= 2;
167	($self->{read_size} - $rbuf_len), $rbuf_len;	2037	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		2038	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		2039	}
		2040
		2041	} elsif (defined $len) {
		2042	delete $self->{_rw};
		2043	$self->{_eof} = 1;
		2044	$self->_drain_rbuf;
		2045
		2046	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		2047	return $self->_error ($!, 1);
		2048	}
		2049	};
		2050	}
		2051	}
		2052
		2053	our $ERROR_SYSCALL;
		2054	our $ERROR_WANT_READ;
		2055
		2056	sub _tls_error {
		2057	my ($self, $err) = @_;
		2058
		2059	return $self->_error ($!, 1)
		2060	if $err == Net::SSLeay::ERROR_SYSCALL ();
		2061
		2062	my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		2063
		2064	# reduce error string to look less scary
		2065	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		2066
		2067	if ($self->{_on_starttls}) {
		2068	(delete $self->{_on_starttls})->($self, undef, $err);
		2069	&_freetls;
		2070	} else {
		2071	&_freetls;
		2072	$self->_error (Errno::EPROTO, 1, $err);
		2073	}
		2074	}
		2075
		2076	# poll the write BIO and send the data if applicable
		2077	# also decode read data if possible
		2078	# this is basiclaly our TLS state machine
		2079	# more efficient implementations are possible with openssl,
		2080	# but not with the buggy and incomplete Net::SSLeay.
		2081	sub _dotls {
		2082	my ($self) = @_;
		2083
		2084	my $tmp;
		2085
		2086	while (length $self->{_tls_wbuf}) {
		2087	if (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) <= 0) {
		2088	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		2089
		2090	return $self->_tls_error ($tmp)
		2091	if $tmp != $ERROR_WANT_READ
		2092	&& ($tmp != $ERROR_SYSCALL || $!);
		2093
		2094	last;
		2095	}
		2096
		2097	substr $self->{_tls_wbuf}, 0, $tmp, "";
		2098	}
		2099
		2100	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		2101	unless (length $tmp) {
		2102	$self->{_on_starttls}
		2103	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		2104	&_freetls;
		2105
		2106	if ($self->{on_stoptls}) {
		2107	$self->{on_stoptls}($self);
		2108	return;
168	} else {	2109	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	2110	# 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};	2111	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, separated by C<$sep> or C<"\n">
261	if C<$sep> is not provided. C<$sep> will be used as "line" separated.
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];	2112	$self->{_eof} = 1;
324	}	2113	}
325	}	2114	}
326	return;
327	}
328		2115
329	my $wba = shift @{$self->{write_bufs}}	2116	$self->{_tls_rbuf} .= $tmp;
330	or return;	2117	$self->_drain_rbuf;
331		2118	$self->{tls} or return; # tls session might have gone away in callback
332	unless (defined $wba->[0]) {
333	$wba->[1]->($self) if $wba->[1];
334	$self->_check_writer;
335	return;
336	}	2119	}
337		2120
338	$self->{wbuf} = $wba->[0];	2121	$tmp = Net::SSLeay::get_error ($self->{tls}, -1); # -1 is not neccessarily correct, but Net::SSLeay doesn't tell us
339	$self->{write_cb} = $wba->[1];	2122	return $self->_tls_error ($tmp)
		2123	if $tmp != $ERROR_WANT_READ
		2124	&& ($tmp != $ERROR_SYSCALL || $!);
340		2125
341	$self->{write_w} =	2126	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
342	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	2127	$self->{wbuf} .= $tmp;
343	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	2128	$self->_drain_wbuf;
		2129	$self->{tls} or return; # tls session might have gone away in callback
		2130	}
344		2131
345	if (not defined $l) {	2132	$self->{_on_starttls}
346	return if $! == EAGAIN || $! == EINTR;	2133	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
347	delete $self->{write_w};	2134	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
348	$self->{on_error}->($self) if $self->{on_error};	2135	}
349		2136
		2137	=item $handle->starttls ($tls[, $tls_ctx])
		2138
		2139	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		2140	object is created, you can also do that at a later time by calling
		2141	C<starttls>. See the C<tls> constructor argument for general info.
		2142
		2143	Starting TLS is currently an asynchronous operation - when you push some
		2144	write data and then call C<< ->starttls >> then TLS negotiation will start
		2145	immediately, after which the queued write data is then sent. This might
		2146	change in future versions, so best make sure you have no outstanding write
		2147	data when calling this method.
		2148
		2149	The first argument is the same as the C<tls> constructor argument (either
		2150	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		2151
		2152	The second argument is the optional C<AnyEvent::TLS> object that is used
		2153	when AnyEvent::Handle has to create its own TLS connection object, or
		2154	a hash reference with C<< key => value >> pairs that will be used to
		2155	construct a new context.
		2156
		2157	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		2158	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		2159	changed to your liking. Note that the handshake might have already started
		2160	when this function returns.
		2161
		2162	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		2163	handshakes on the same stream. It is best to not attempt to use the
		2164	stream after stopping TLS.
		2165
		2166	This method may invoke callbacks (and therefore the handle might be
		2167	destroyed after it returns).
		2168
		2169	=cut
		2170
		2171	our %TLS_CACHE; #TODO not yet documented, should we?
		2172
		2173	sub starttls {
		2174	my ($self, $tls, $ctx) = @_;
		2175
		2176	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		2177	if $self->{tls};
		2178
		2179	unless (defined $AnyEvent::TLS::VERSION) {
		2180	eval {
		2181	require Net::SSLeay;
		2182	require AnyEvent::TLS;
		2183	1
		2184	} or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
		2185	}
		2186
		2187	$self->{tls} = $tls;
		2188	$self->{tls_ctx} = $ctx if @_ > 2;
		2189
		2190	return unless $self->{fh};
		2191
		2192	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		2193	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		2194
		2195	$tls = delete $self->{tls};
		2196	$ctx = $self->{tls_ctx};
		2197
		2198	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		2199
		2200	if ("HASH" eq ref $ctx) {
		2201	if ($ctx->{cache}) {
		2202	my $key = $ctx+0;
		2203	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
350	} else {	2204	} else {
		2205	$ctx = new AnyEvent::TLS %$ctx;
		2206	}
		2207	}
		2208
		2209	$self->{tls_ctx} = $ctx || TLS_CTX ();
		2210	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		2211
		2212	# basically, this is deep magic (because SSL_read should have the same issues)
		2213	# but the openssl maintainers basically said: "trust us, it just works".
		2214	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		2215	# and mismaintained ssleay-module doesn't even offer them).
		2216	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		2217	#
		2218	# in short: this is a mess.
		2219	#
		2220	# note that we do not try to keep the length constant between writes as we are required to do.
		2221	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		2222	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2223	# have identity issues in that area.
		2224	# Net::SSLeay::CTX_set_mode ($ssl,
		2225	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		2226	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2227	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		2228
		2229	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		2230	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		2231
		2232	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2233	$self->{rbuf} = "";
		2234
		2235	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		2236
		2237	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		2238	if $self->{on_starttls};
		2239
		2240	&_dotls; # need to trigger the initial handshake
		2241	$self->start_read; # make sure we actually do read
		2242	}
		2243
		2244	=item $handle->stoptls
		2245
		2246	Shuts down the SSL connection - this makes a proper EOF handshake by
		2247	sending a close notify to the other side, but since OpenSSL doesn't
		2248	support non-blocking shut downs, it is not guaranteed that you can re-use
		2249	the stream afterwards.
		2250
		2251	This method may invoke callbacks (and therefore the handle might be
		2252	destroyed after it returns).
		2253
		2254	=cut
		2255
		2256	sub stoptls {
		2257	my ($self) = @_;
		2258
		2259	if ($self->{tls} && $self->{fh}) {
		2260	Net::SSLeay::shutdown ($self->{tls});
		2261
		2262	&_dotls;
		2263
		2264	# # we don't give a shit. no, we do, but we can't. no...#d#
		2265	# # we, we... have to use openssl :/#d#
		2266	# &_freetls;#d#
		2267	}
		2268	}
		2269
		2270	sub _freetls {
		2271	my ($self) = @_;
		2272
		2273	return unless $self->{tls};
		2274
		2275	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2276	if $self->{tls} > 0;
		2277
		2278	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2279	}
		2280
		2281	=item $handle->resettls
		2282
		2283	This rarely-used method simply resets and TLS state on the handle, usually
		2284	causing data loss.
		2285
		2286	One case where it may be useful is when you want to skip over the data in
		2287	the stream but you are not interested in interpreting it, so data loss is
		2288	no concern.
		2289
		2290	=cut
		2291
		2292	*resettls = \&_freetls;
		2293
		2294	sub DESTROY {
		2295	my ($self) = @_;
		2296
		2297	&_freetls;
		2298
		2299	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2300
		2301	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2302	my $fh = delete $self->{fh};
		2303	my $wbuf = delete $self->{wbuf};
		2304
		2305	my @linger;
		2306
		2307	push @linger, AE::io $fh, 1, sub {
		2308	my $len = syswrite $fh, $wbuf, length $wbuf;
		2309
		2310	if ($len > 0) {
351	substr $self->{wbuf}, 0, $l, '';	2311	substr $wbuf, 0, $len, "";
352		2312	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
353	if (length ($self->{wbuf}) == 0) {	2313	@linger = (); # end
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	}	2314	}
		2315	};
		2316	push @linger, AE::timer $linger, 0, sub {
		2317	@linger = ();
		2318	};
		2319	}
		2320	}
		2321
		2322	=item $handle->destroy
		2323
		2324	Shuts down the handle object as much as possible - this call ensures that
		2325	no further callbacks will be invoked and as many resources as possible
		2326	will be freed. Any method you will call on the handle object after
		2327	destroying it in this way will be silently ignored (and it will return the
		2328	empty list).
		2329
		2330	Normally, you can just "forget" any references to an AnyEvent::Handle
		2331	object and it will simply shut down. This works in fatal error and EOF
		2332	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2333	callback, so when you want to destroy the AnyEvent::Handle object from
		2334	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2335	that case.
		2336
		2337	Destroying the handle object in this way has the advantage that callbacks
		2338	will be removed as well, so if those are the only reference holders (as
		2339	is common), then one doesn't need to do anything special to break any
		2340	reference cycles.
		2341
		2342	The handle might still linger in the background and write out remaining
		2343	data, as specified by the C<linger> option, however.
		2344
		2345	=cut
		2346
		2347	sub destroy {
		2348	my ($self) = @_;
		2349
		2350	$self->DESTROY;
		2351	%$self = ();
		2352	bless $self, "AnyEvent::Handle::destroyed";
		2353	}
		2354
		2355	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2356	#nop
		2357	}
		2358
		2359	=item $handle->destroyed
		2360
		2361	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2362	->destroy >>, true otherwise.
		2363
		2364	Can be useful to decide whether the handle is still valid after some
		2365	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2366	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2367	can destroy the handle, so work can be avoided by checking sometimes:
		2368
		2369	$hdl->starttls ("accept");
		2370	return if $hdl->destroyed;
		2371	$hdl->push_write (...
		2372
		2373	Note that the call to C<push_write> will silently be ignored if the handle
		2374	has been destroyed, so often you can just ignore the possibility of the
		2375	handle being destroyed.
		2376
		2377	=cut
		2378
		2379	sub destroyed { 0 }
		2380	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2381
		2382	=item AnyEvent::Handle::TLS_CTX
		2383
		2384	This function creates and returns the AnyEvent::TLS object used by default
		2385	for TLS mode.
		2386
		2387	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2388
		2389	=cut
		2390
		2391	our $TLS_CTX;
		2392
		2393	sub TLS_CTX() {
		2394	$TLS_CTX ||= do {
		2395	require AnyEvent::TLS;
		2396
		2397	new AnyEvent::TLS
		2398	}
		2399	}
		2400
		2401	=back
		2402
		2403
		2404	=head1 NONFREQUENTLY ASKED QUESTIONS
		2405
		2406	=over 4
		2407
		2408	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2409	still get further invocations!
		2410
		2411	That's because AnyEvent::Handle keeps a reference to itself when handling
		2412	read or write callbacks.
		2413
		2414	It is only safe to "forget" the reference inside EOF or error callbacks,
		2415	from within all other callbacks, you need to explicitly call the C<<
		2416	->destroy >> method.
		2417
		2418	=item Why is my C<on_eof> callback never called?
		2419
		2420	Probably because your C<on_error> callback is being called instead: When
		2421	you have outstanding requests in your read queue, then an EOF is
		2422	considered an error as you clearly expected some data.
		2423
		2424	To avoid this, make sure you have an empty read queue whenever your handle
		2425	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2426	an C<on_read> handler that simply pushes the first read requests in the
		2427	queue.
		2428
		2429	See also the next question, which explains this in a bit more detail.
		2430
		2431	=item How can I serve requests in a loop?
		2432
		2433	Most protocols consist of some setup phase (authentication for example)
		2434	followed by a request handling phase, where the server waits for requests
		2435	and handles them, in a loop.
		2436
		2437	There are two important variants: The first (traditional, better) variant
		2438	handles requests until the server gets some QUIT command, causing it to
		2439	close the connection first (highly desirable for a busy TCP server). A
		2440	client dropping the connection is an error, which means this variant can
		2441	detect an unexpected detection close.
		2442
		2443	To handle this case, always make sure you have a non-empty read queue, by
		2444	pushing the "read request start" handler on it:
		2445
		2446	# we assume a request starts with a single line
		2447	my @start_request; @start_request = (line => sub {
		2448	my ($hdl, $line) = @_;
		2449
		2450	... handle request
		2451
		2452	# push next request read, possibly from a nested callback
		2453	$hdl->push_read (@start_request);
		2454	});
		2455
		2456	# auth done, now go into request handling loop
		2457	# now push the first @start_request
		2458	$hdl->push_read (@start_request);
		2459
		2460	By always having an outstanding C<push_read>, the handle always expects
		2461	some data and raises the C<EPIPE> error when the connction is dropped
		2462	unexpectedly.
		2463
		2464	The second variant is a protocol where the client can drop the connection
		2465	at any time. For TCP, this means that the server machine may run out of
		2466	sockets easier, and in general, it means you cannot distinguish a protocl
		2467	failure/client crash from a normal connection close. Nevertheless, these
		2468	kinds of protocols are common (and sometimes even the best solution to the
		2469	problem).
		2470
		2471	Having an outstanding read request at all times is possible if you ignore
		2472	C<EPIPE> errors, but this doesn't help with when the client drops the
		2473	connection during a request, which would still be an error.
		2474
		2475	A better solution is to push the initial request read in an C<on_read>
		2476	callback. This avoids an error, as when the server doesn't expect data
		2477	(i.e. is idly waiting for the next request, an EOF will not raise an
		2478	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2479	and simpler:
		2480
		2481	# auth done, now go into request handling loop
		2482	$hdl->on_read (sub {
		2483	my ($hdl) = @_;
		2484
		2485	# called each time we receive data but the read queue is empty
		2486	# simply start read the request
		2487
		2488	$hdl->push_read (line => sub {
		2489	my ($hdl, $line) = @_;
		2490
		2491	... handle request
		2492
		2493	# do nothing special when the request has been handled, just
		2494	# let the request queue go empty.
363	});	2495	});
364	}	2496	});
		2497
		2498	=item I get different callback invocations in TLS mode/Why can't I pause
		2499	reading?
		2500
		2501	Unlike, say, TCP, TLS connections do not consist of two independent
		2502	communication channels, one for each direction. Or put differently, the
		2503	read and write directions are not independent of each other: you cannot
		2504	write data unless you are also prepared to read, and vice versa.
		2505
		2506	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2507	callback invocations when you are not expecting any read data - the reason
		2508	is that AnyEvent::Handle always reads in TLS mode.
		2509
		2510	During the connection, you have to make sure that you always have a
		2511	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2512	connection (or when you no longer want to use it) you can call the
		2513	C<destroy> method.
		2514
		2515	=item How do I read data until the other side closes the connection?
		2516
		2517	If you just want to read your data into a perl scalar, the easiest way
		2518	to achieve this is by setting an C<on_read> callback that does nothing,
		2519	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2520	will be in C<$_[0]{rbuf}>:
		2521
		2522	$handle->on_read (sub { });
		2523	$handle->on_eof (undef);
		2524	$handle->on_error (sub {
		2525	my $data = delete $_[0]{rbuf};
		2526	});
		2527
		2528	Note that this example removes the C<rbuf> member from the handle object,
		2529	which is not normally allowed by the API. It is expressly permitted in
		2530	this case only, as the handle object needs to be destroyed afterwards.
		2531
		2532	The reason to use C<on_error> is that TCP connections, due to latencies
		2533	and packets loss, might get closed quite violently with an error, when in
		2534	fact all data has been received.
		2535
		2536	It is usually better to use acknowledgements when transferring data,
		2537	to make sure the other side hasn't just died and you got the data
		2538	intact. This is also one reason why so many internet protocols have an
		2539	explicit QUIT command.
		2540
		2541	=item I don't want to destroy the handle too early - how do I wait until
		2542	all data has been written?
		2543
		2544	After writing your last bits of data, set the C<on_drain> callback
		2545	and destroy the handle in there - with the default setting of
		2546	C<low_water_mark> this will be called precisely when all data has been
		2547	written to the socket:
		2548
		2549	$handle->push_write (...);
		2550	$handle->on_drain (sub {
		2551	AE::log debug => "All data submitted to the kernel.";
		2552	undef $handle;
		2553	});
		2554
		2555	If you just want to queue some data and then signal EOF to the other side,
		2556	consider using C<< ->push_shutdown >> instead.
		2557
		2558	=item I want to contact a TLS/SSL server, I don't care about security.
		2559
		2560	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2561	connect to it and then create the AnyEvent::Handle with the C<tls>
		2562	parameter:
		2563
		2564	tcp_connect $host, $port, sub {
		2565	my ($fh) = @_;
		2566
		2567	my $handle = new AnyEvent::Handle
		2568	fh => $fh,
		2569	tls => "connect",
		2570	on_error => sub { ... };
		2571
		2572	$handle->push_write (...);
		2573	};
		2574
		2575	=item I want to contact a TLS/SSL server, I do care about security.
		2576
		2577	Then you should additionally enable certificate verification, including
		2578	peername verification, if the protocol you use supports it (see
		2579	L<AnyEvent::TLS>, C<verify_peername>).
		2580
		2581	E.g. for HTTPS:
		2582
		2583	tcp_connect $host, $port, sub {
		2584	my ($fh) = @_;
		2585
		2586	my $handle = new AnyEvent::Handle
		2587	fh => $fh,
		2588	peername => $host,
		2589	tls => "connect",
		2590	tls_ctx => { verify => 1, verify_peername => "https" },
		2591	...
		2592
		2593	Note that you must specify the hostname you connected to (or whatever
		2594	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2595	peername verification will be done.
		2596
		2597	The above will use the system-dependent default set of trusted CA
		2598	certificates. If you want to check against a specific CA, add the
		2599	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2600
		2601	tls_ctx => {
		2602	verify => 1,
		2603	verify_peername => "https",
		2604	ca_file => "my-ca-cert.pem",
		2605	},
		2606
		2607	=item I want to create a TLS/SSL server, how do I do that?
		2608
		2609	Well, you first need to get a server certificate and key. You have
		2610	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2611	self-signed certificate (cheap. check the search engine of your choice,
		2612	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2613	nice program for that purpose).
		2614
		2615	Then create a file with your private key (in PEM format, see
		2616	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2617	file should then look like this:
		2618
		2619	-----BEGIN RSA PRIVATE KEY-----
		2620	...header data
		2621	... lots of base64'y-stuff
		2622	-----END RSA PRIVATE KEY-----
		2623
		2624	-----BEGIN CERTIFICATE-----
		2625	... lots of base64'y-stuff
		2626	-----END CERTIFICATE-----
		2627
		2628	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2629	specify this file as C<cert_file>:
		2630
		2631	tcp_server undef, $port, sub {
		2632	my ($fh) = @_;
		2633
		2634	my $handle = new AnyEvent::Handle
		2635	fh => $fh,
		2636	tls => "accept",
		2637	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2638	...
		2639
		2640	When you have intermediate CA certificates that your clients might not
		2641	know about, just append them to the C<cert_file>.
365		2642
366	=back	2643	=back
367		2644
		2645	=head1 SUBCLASSING AnyEvent::Handle
		2646
		2647	In many cases, you might want to subclass AnyEvent::Handle.
		2648
		2649	To make this easier, a given version of AnyEvent::Handle uses these
		2650	conventions:
		2651
		2652	=over 4
		2653
		2654	=item * all constructor arguments become object members.
		2655
		2656	At least initially, when you pass a C<tls>-argument to the constructor it
		2657	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2658	mutated later on (for example C<tls> will hold the TLS connection object).
		2659
		2660	=item * other object member names are prefixed with an C<_>.
		2661
		2662	All object members not explicitly documented (internal use) are prefixed
		2663	with an underscore character, so the remaining non-C<_>-namespace is free
		2664	for use for subclasses.
		2665
		2666	=item * all members not documented here and not prefixed with an underscore
		2667	are free to use in subclasses.
		2668
		2669	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2670	member variables, but that's just life. At least it is documented.
		2671
		2672	=back
		2673
368	=head1 AUTHOR	2674	=head1 AUTHOR
369		2675
370	Robin Redeker, C<< <elmex at ta-sa.org> >>	2676	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
371		2677
372	=cut	2678	=cut
373		2679
374	1; # End of AnyEvent::Handle	2680	1
		2681

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