ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent/Handle.pm

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.4 by elmex, Sun Apr 27 20:20:20 2008 UTC vs.
Revision 1.242 by root, Wed Dec 10 04:29:33 2014 UTC

1	package AnyEvent::Handle;
2
3	use warnings;
4	use strict;
5
6	use AnyEvent;
7	use IO::Handle;
8	use Errno qw/EAGAIN EINTR/;
9
10	=head1 NAME	1	=head1 NAME
11		2
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on 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, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback. At the time it is called the
		134	read and write queues, EOF status, TLS status and similar properties of
		135	the handle will have been reset.
		136
		137	If, for some reason, the handle is not acceptable, calling C<$retry> will
		138	continue with the next connection target (in case of multi-homed hosts or
		139	SRV records there can be multiple connection endpoints). The C<$retry>
		140	callback can be invoked after the connect callback returns, i.e. one can
		141	start a handshake and then decide to retry with the next host if the
		142	handshake fails.
		143
		144	In most cases, you should ignore the C<$retry> parameter.
		145
		146	=item on_connect_error => $cb->($handle, $message)
		147
		148	This callback is called when the connection could not be
		149	established. C<$!> will contain the relevant error code, and C<$message> a
		150	message describing it (usually the same as C<"$!">).
		151
		152	If this callback isn't specified, then C<on_error> will be called with a
		153	fatal error instead.
		154
		155	=back
		156
		157	=item on_error => $cb->($handle, $fatal, $message)
		158
		159	This is the error callback, which is called when, well, some error
		160	occured, such as not being able to resolve the hostname, failure to
		161	connect, or a read error.
		162
		163	Some errors are fatal (which is indicated by C<$fatal> being true). On
		164	fatal errors the handle object will be destroyed (by a call to C<< ->
		165	destroy >>) after invoking the error callback (which means you are free to
		166	examine the handle object). Examples of fatal errors are an EOF condition
		167	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		168	cases where the other side can close the connection at will, it is
		169	often easiest to not report C<EPIPE> errors in this callback.
		170
		171	AnyEvent::Handle tries to find an appropriate error code for you to check
		172	against, but in some cases (TLS errors), this does not work well.
		173
		174	If you report the error to the user, it is recommended to always output
		175	the C<$message> argument in human-readable error messages (you don't need
		176	to report C<"$!"> if you report C<$message>).
		177
		178	If you want to react programmatically to the error, then looking at C<$!>
		179	and comparing it against some of the documented C<Errno> values is usually
		180	better than looking at the C<$message>.
		181
		182	Non-fatal errors can be retried by returning, but it is recommended
		183	to simply ignore this parameter and instead abondon the handle object
		184	when this callback is invoked. Examples of non-fatal errors are timeouts
		185	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		186
		187	On entry to the callback, the value of C<$!> contains the operating
		188	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		189	C<EPROTO>).
		190
		191	While not mandatory, it is I<highly> recommended to set this callback, as
		192	you will not be notified of errors otherwise. The default just calls
		193	C<croak>.
		194
		195	=item on_read => $cb->($handle)
		196
		197	This sets the default read callback, which is called when data arrives
		198	and no read request is in the queue (unlike read queue callbacks, this
		199	callback will only be called when at least one octet of data is in the
		200	read buffer).
		201
		202	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		203	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		204	must not enlarge or modify the read buffer, you can only remove data at
		205	the beginning from it.
		206
		207	You can also call C<< ->push_read (...) >> or any other function that
		208	modifies the read queue. Or do both. Or ...
		209
		210	When an EOF condition is detected, AnyEvent::Handle will first try to
		211	feed all the remaining data to the queued callbacks and C<on_read> before
		212	calling the C<on_eof> callback. If no progress can be made, then a fatal
		213	error will be raised (with C<$!> set to C<EPIPE>).
		214
		215	Note that, unlike requests in the read queue, an C<on_read> callback
		216	doesn't mean you I<require> some data: if there is an EOF and there
		217	are outstanding read requests then an error will be flagged. With an
		218	C<on_read> callback, the C<on_eof> callback will be invoked.
		219
		220	=item on_eof => $cb->($handle)
		221
		222	Set the callback to be called when an end-of-file condition is detected,
		223	i.e. in the case of a socket, when the other side has closed the
		224	connection cleanly, and there are no outstanding read requests in the
		225	queue (if there are read requests, then an EOF counts as an unexpected
		226	connection close and will be flagged as an error).
		227
		228	For sockets, this just means that the other side has stopped sending data,
		229	you can still try to write data, and, in fact, one can return from the EOF
		230	callback and continue writing data, as only the read part has been shut
		231	down.
		232
		233	If an EOF condition has been detected but no C<on_eof> callback has been
		234	set, then a fatal error will be raised with C<$!> set to <0>.
		235
		236	=item on_drain => $cb->($handle)
		237
		238	This sets the callback that is called once when the write buffer becomes
		239	empty (and immediately when the handle object is created).
		240
		241	To append to the write buffer, use the C<< ->push_write >> method.
		242
		243	This callback is useful when you don't want to put all of your write data
		244	into the queue at once, for example, when you want to write the contents
		245	of some file to the socket you might not want to read the whole file into
		246	memory and push it into the queue, but instead only read more data from
		247	the file when the write queue becomes empty.
		248
		249	=item timeout => $fractional_seconds
		250
		251	=item rtimeout => $fractional_seconds
		252
		253	=item wtimeout => $fractional_seconds
		254
		255	If non-zero, then these enables an "inactivity" timeout: whenever this
		256	many seconds pass without a successful read or write on the underlying
		257	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		258	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		259	error will be raised).
		260
		261	There are three variants of the timeouts that work independently of each
		262	other, for both read and write (triggered when nothing was read I<OR>
		263	written), just read (triggered when nothing was read), and just write:
		264	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		265	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		266	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		267
		268	Note that timeout processing is active even when you do not have any
		269	outstanding read or write requests: If you plan to keep the connection
		270	idle then you should disable the timeout temporarily or ignore the
		271	timeout in the corresponding C<on_timeout> callback, in which case
		272	AnyEvent::Handle will simply restart the timeout.
		273
		274	Zero (the default) disables the corresponding timeout.
		275
		276	=item on_timeout => $cb->($handle)
		277
		278	=item on_rtimeout => $cb->($handle)
		279
		280	=item on_wtimeout => $cb->($handle)
		281
		282	Called whenever the inactivity timeout passes. If you return from this
		283	callback, then the timeout will be reset as if some activity had happened,
		284	so this condition is not fatal in any way.
		285
		286	=item rbuf_max => <bytes>
		287
		288	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		289	when the read buffer ever (strictly) exceeds this size. This is useful to
		290	avoid some forms of denial-of-service attacks.
		291
		292	For example, a server accepting connections from untrusted sources should
		293	be configured to accept only so-and-so much data that it cannot act on
		294	(for example, when expecting a line, an attacker could send an unlimited
		295	amount of data without a callback ever being called as long as the line
		296	isn't finished).
		297
		298	=item wbuf_max => <bytes>
		299
		300	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		301	when the write buffer ever (strictly) exceeds this size. This is useful to
		302	avoid some forms of denial-of-service attacks.
		303
		304	Although the units of this parameter is bytes, this is the I<raw> number
		305	of bytes not yet accepted by the kernel. This can make a difference when
		306	you e.g. use TLS, as TLS typically makes your write data larger (but it
		307	can also make it smaller due to compression).
		308
		309	As an example of when this limit is useful, take a chat server that sends
		310	chat messages to a client. If the client does not read those in a timely
		311	manner then the send buffer in the server would grow unbounded.
		312
		313	=item autocork => <boolean>
		314
		315	When disabled (the default), C<push_write> will try to immediately
		316	write the data to the handle if possible. This avoids having to register
		317	a write watcher and wait for the next event loop iteration, but can
		318	be inefficient if you write multiple small chunks (on the wire, this
		319	disadvantage is usually avoided by your kernel's nagle algorithm, see
		320	C<no_delay>, but this option can save costly syscalls).
		321
		322	When enabled, writes will always be queued till the next event loop
		323	iteration. This is efficient when you do many small writes per iteration,
		324	but less efficient when you do a single write only per iteration (or when
		325	the write buffer often is full). It also increases write latency.
		326
		327	=item no_delay => <boolean>
		328
		329	When doing small writes on sockets, your operating system kernel might
		330	wait a bit for more data before actually sending it out. This is called
		331	the Nagle algorithm, and usually it is beneficial.
		332
		333	In some situations you want as low a delay as possible, which can be
		334	accomplishd by setting this option to a true value.
		335
		336	The default is your operating system's default behaviour (most likely
		337	enabled). This option explicitly enables or disables it, if possible.
		338
		339	=item keepalive => <boolean>
		340
		341	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		342	normally, TCP connections have no time-out once established, so TCP
		343	connections, once established, can stay alive forever even when the other
		344	side has long gone. TCP keepalives are a cheap way to take down long-lived
		345	TCP connections when the other side becomes unreachable. While the default
		346	is OS-dependent, TCP keepalives usually kick in after around two hours,
		347	and, if the other side doesn't reply, take down the TCP connection some 10
		348	to 15 minutes later.
		349
		350	It is harmless to specify this option for file handles that do not support
		351	keepalives, and enabling it on connections that are potentially long-lived
		352	is usually a good idea.
		353
		354	=item oobinline => <boolean>
		355
		356	BSD majorly fucked up the implementation of TCP urgent data. The result
		357	is that almost no OS implements TCP according to the specs, and every OS
		358	implements it slightly differently.
		359
		360	If you want to handle TCP urgent data, then setting this flag (the default
		361	is enabled) gives you the most portable way of getting urgent data, by
		362	putting it into the stream.
		363
		364	Since BSD emulation of OOB data on top of TCP's urgent data can have
		365	security implications, AnyEvent::Handle sets this flag automatically
		366	unless explicitly specified. Note that setting this flag after
		367	establishing a connection I<may> be a bit too late (data loss could
		368	already have occured on BSD systems), but at least it will protect you
		369	from most attacks.
		370
		371	=item read_size => <bytes>
		372
		373	The initial read block size, the number of bytes this module will try
		374	to read during each loop iteration. Each handle object will consume
		375	at least this amount of memory for the read buffer as well, so when
		376	handling many connections watch out for memory requirements). See also
		377	C<max_read_size>. Default: C<2048>.
		378
		379	=item max_read_size => <bytes>
		380
		381	The maximum read buffer size used by the dynamic adjustment
		382	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		383	one go it will double C<read_size> up to the maximum given by this
		384	option. Default: C<131072> or C<read_size>, whichever is higher.
		385
		386	=item low_water_mark => <bytes>
		387
		388	Sets the number of bytes (default: C<0>) that make up an "empty" write
		389	buffer: If the buffer reaches this size or gets even samller it is
		390	considered empty.
		391
		392	Sometimes it can be beneficial (for performance reasons) to add data to
		393	the write buffer before it is fully drained, but this is a rare case, as
		394	the operating system kernel usually buffers data as well, so the default
		395	is good in almost all cases.
		396
		397	=item linger => <seconds>
		398
		399	If this is non-zero (default: C<3600>), the destructor of the
		400	AnyEvent::Handle object will check whether there is still outstanding
		401	write data and will install a watcher that will write this data to the
		402	socket. No errors will be reported (this mostly matches how the operating
		403	system treats outstanding data at socket close time).
		404
		405	This will not work for partial TLS data that could not be encoded
		406	yet. This data will be lost. Calling the C<stoptls> method in time might
		407	help.
		408
		409	=item peername => $string
		410
		411	A string used to identify the remote site - usually the DNS hostname
		412	(I<not> IDN!) used to create the connection, rarely the IP address.
		413
		414	Apart from being useful in error messages, this string is also used in TLS
		415	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		416	verification will be skipped when C<peername> is not specified or is
		417	C<undef>.
		418
		419	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		420
		421	When this parameter is given, it enables TLS (SSL) mode, that means
		422	AnyEvent will start a TLS handshake as soon as the connection has been
		423	established and will transparently encrypt/decrypt data afterwards.
		424
		425	All TLS protocol errors will be signalled as C<EPROTO>, with an
		426	appropriate error message.
		427
		428	TLS mode requires Net::SSLeay to be installed (it will be loaded
		429	automatically when you try to create a TLS handle): this module doesn't
		430	have a dependency on that module, so if your module requires it, you have
		431	to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
		432	old, you get an C<EPROTO> error.
		433
		434	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		435	C<accept>, and for the TLS client side of a connection, use C<connect>
		436	mode.
		437
		438	You can also provide your own TLS connection object, but you have
		439	to make sure that you call either C<Net::SSLeay::set_connect_state>
		440	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		441	AnyEvent::Handle. Also, this module will take ownership of this connection
		442	object.
		443
		444	At some future point, AnyEvent::Handle might switch to another TLS
		445	implementation, then the option to use your own session object will go
		446	away.
		447
		448	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		449	passing in the wrong integer will lead to certain crash. This most often
		450	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		451	segmentation fault.
		452
		453	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
		454
		455	=item tls_ctx => $anyevent_tls
		456
		457	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		458	(unless a connection object was specified directly). If this
		459	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		460	C<AnyEvent::Handle::TLS_CTX>.
		461
		462	Instead of an object, you can also specify a hash reference with C<< key
		463	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		464	new TLS context object.
		465
		466	=item on_starttls => $cb->($handle, $success[, $error_message])
		467
		468	This callback will be invoked when the TLS/SSL handshake has finished. If
		469	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		470	(C<on_stoptls> will not be called in this case).
		471
		472	The session in C<< $handle->{tls} >> can still be examined in this
		473	callback, even when the handshake was not successful.
		474
		475	TLS handshake failures will not cause C<on_error> to be invoked when this
		476	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		477
		478	Without this callback, handshake failures lead to C<on_error> being
		479	called as usual.
		480
		481	Note that you cannot just call C<starttls> again in this callback. If you
		482	need to do that, start an zero-second timer instead whose callback can
		483	then call C<< ->starttls >> again.
		484
		485	=item on_stoptls => $cb->($handle)
		486
		487	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		488	set, then it will be invoked after freeing the TLS session. If it is not,
		489	then a TLS shutdown condition will be treated like a normal EOF condition
		490	on the handle.
		491
		492	The session in C<< $handle->{tls} >> can still be examined in this
		493	callback.
		494
		495	This callback will only be called on TLS shutdowns, not when the
		496	underlying handle signals EOF.
		497
		498	=item json => L<JSON>, L<JSON::PP> or L<JSON::XS> object
		499
		500	This is the json coder object used by the C<json> read and write types.
		501
		502	If you don't supply it, then AnyEvent::Handle will create and use a
		503	suitable one (on demand), which will write and expect UTF-8 encoded
		504	JSON texts (either using L<JSON::XS> or L<JSON>). The written texts are
		505	guaranteed not to contain any newline character.
		506
		507	For security reasons, this encoder will likely I<not> handle numbers and
		508	strings, only arrays and objects/hashes. The reason is that originally
		509	JSON was self-delimited, but Dougles Crockford thought it was a splendid
		510	idea to redefine JSON incompatibly, so this is no longer true.
		511
		512	For protocols that used back-to-back JSON texts, this might lead to
		513	run-ins, where two or more JSON texts will be interpreted as one JSON
		514	text.
		515
		516	For this reason, if the default encoder uses L<JSON::XS>, it will default
		517	to not allowing anything but arrays and objects/hashes, at least for the
		518	forseeable future (it will change at some point). This might or might not
		519	be true for the L<JSON> module, so this might cause a security issue.
		520
		521	If you depend on either behaviour, you should create your own json object
		522	and pass it in explicitly.
		523
		524	=item cbor => L<CBOR::XS> object
		525
		526	This is the cbor coder object used by the C<cbor> read and write types.
		527
		528	If you don't supply it, then AnyEvent::Handle will create and use a
		529	suitable one (on demand), which will write CBOR without using extensions,
		530	if possible.
		531
		532	Note that you are responsible to depend on the L<CBOR::XS> module if you
		533	want to use this functionality, as AnyEvent does not have a dependency on
		534	it itself.
		535
		536	=back
		537
		538	=cut
		539
		540	sub new {
		541	my $class = shift;
		542	my $self = bless { @_ }, $class;
		543
		544	if ($self->{fh}) {
		545	$self->_start;
		546	return unless $self->{fh}; # could be gone by now
		547
		548	} elsif ($self->{connect}) {
		549	require AnyEvent::Socket;
		550
		551	$self->{peername} = $self->{connect}[0]
		552	unless exists $self->{peername};
		553
		554	$self->{_skip_drain_rbuf} = 1;
		555
		556	{
		557	Scalar::Util::weaken (my $self = $self);
		558
		559	$self->{_connect} =
		560	AnyEvent::Socket::tcp_connect (
		561	$self->{connect}[0],
		562	$self->{connect}[1],
		563	sub {
		564	my ($fh, $host, $port, $retry) = @_;
		565
		566	delete $self->{_connect}; # no longer needed
		567
		568	if ($fh) {
		569	$self->{fh} = $fh;
		570
		571	delete $self->{_skip_drain_rbuf};
		572	$self->_start;
		573
		574	$self->{on_connect}
		575	and $self->{on_connect}($self, $host, $port, sub {
		576	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		577	$self->{_skip_drain_rbuf} = 1;
		578	&$retry;
		579	});
		580
		581	} else {
		582	if ($self->{on_connect_error}) {
		583	$self->{on_connect_error}($self, "$!");
		584	$self->destroy if $self;
		585	} else {
		586	$self->_error ($!, 1);
		587	}
		588	}
		589	},
		590	sub {
		591	local $self->{fh} = $_[0];
		592
		593	$self->{on_prepare}
		594	? $self->{on_prepare}->($self)
		595	: ()
		596	}
		597	);
		598	}
		599
		600	} else {
		601	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		602	}
		603
		604	$self
		605	}
		606
		607	sub _start {
		608	my ($self) = @_;
		609
		610	# too many clueless people try to use udp and similar sockets
		611	# with AnyEvent::Handle, do them a favour.
		612	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		613	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		614	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
		615
		616	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		617
		618	$self->{_activity} =
		619	$self->{_ractivity} =
		620	$self->{_wactivity} = AE::now;
		621
		622	$self->{read_size} ||= 2048;
		623	$self->{max_read_size} = $self->{read_size}
		624	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		625
		626	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		627	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		628	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		629
		630	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		631	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		632
		633	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		634
		635	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		636	if $self->{tls};
		637
		638	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
		639
		640	$self->start_read
		641	if $self->{on_read} || @{ $self->{_queue} };
		642
		643	$self->_drain_wbuf;
		644	}
		645
		646	sub _error {
		647	my ($self, $errno, $fatal, $message) = @_;
		648
		649	$! = $errno;
		650	$message ||= "$!";
		651
		652	if ($self->{on_error}) {
		653	$self->{on_error}($self, $fatal, $message);
		654	$self->destroy if $fatal;
		655	} elsif ($self->{fh} || $self->{connect}) {
		656	$self->destroy;
		657	Carp::croak "AnyEvent::Handle uncaught error: $message";
		658	}
		659	}
		660
		661	=item $fh = $handle->fh
		662
		663	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		664
		665	=cut
		666
		667	sub fh { $_[0]{fh} }
		668
		669	=item $handle->on_error ($cb)
		670
		671	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		672
		673	=cut
		674
		675	sub on_error {
		676	$_[0]{on_error} = $_[1];
		677	}
		678
		679	=item $handle->on_eof ($cb)
		680
		681	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		682
		683	=cut
		684
		685	sub on_eof {
		686	$_[0]{on_eof} = $_[1];
		687	}
		688
		689	=item $handle->on_timeout ($cb)
		690
		691	=item $handle->on_rtimeout ($cb)
		692
		693	=item $handle->on_wtimeout ($cb)
		694
		695	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		696	callback, or disables the callback (but not the timeout) if C<$cb> =
		697	C<undef>. See the C<timeout> constructor argument and method.
		698
		699	=cut
		700
		701	# see below
		702
		703	=item $handle->autocork ($boolean)
		704
		705	Enables or disables the current autocork behaviour (see C<autocork>
		706	constructor argument). Changes will only take effect on the next write.
		707
		708	=cut
		709
		710	sub autocork {
		711	$_[0]{autocork} = $_[1];
		712	}
		713
		714	=item $handle->no_delay ($boolean)
		715
		716	Enables or disables the C<no_delay> setting (see constructor argument of
		717	the same name for details).
		718
		719	=cut
		720
		721	sub no_delay {
		722	$_[0]{no_delay} = $_[1];
		723
		724	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		725	if $_[0]{fh};
		726	}
		727
		728	=item $handle->keepalive ($boolean)
		729
		730	Enables or disables the C<keepalive> setting (see constructor argument of
		731	the same name for details).
		732
		733	=cut
		734
		735	sub keepalive {
		736	$_[0]{keepalive} = $_[1];
		737
		738	eval {
		739	local $SIG{__DIE__};
		740	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		741	if $_[0]{fh};
		742	};
		743	}
		744
		745	=item $handle->oobinline ($boolean)
		746
		747	Enables or disables the C<oobinline> setting (see constructor argument of
		748	the same name for details).
		749
		750	=cut
		751
		752	sub oobinline {
		753	$_[0]{oobinline} = $_[1];
		754
		755	eval {
		756	local $SIG{__DIE__};
		757	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		758	if $_[0]{fh};
		759	};
		760	}
		761
		762	=item $handle->keepalive ($boolean)
		763
		764	Enables or disables the C<keepalive> setting (see constructor argument of
		765	the same name for details).
		766
		767	=cut
		768
		769	sub keepalive {
		770	$_[0]{keepalive} = $_[1];
		771
		772	eval {
		773	local $SIG{__DIE__};
		774	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		775	if $_[0]{fh};
		776	};
		777	}
		778
		779	=item $handle->on_starttls ($cb)
		780
		781	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		782
		783	=cut
		784
		785	sub on_starttls {
		786	$_[0]{on_starttls} = $_[1];
		787	}
		788
		789	=item $handle->on_stoptls ($cb)
		790
		791	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		792
		793	=cut
		794
		795	sub on_stoptls {
		796	$_[0]{on_stoptls} = $_[1];
		797	}
		798
		799	=item $handle->rbuf_max ($max_octets)
		800
		801	Configures the C<rbuf_max> setting (C<undef> disables it).
		802
		803	=item $handle->wbuf_max ($max_octets)
		804
		805	Configures the C<wbuf_max> setting (C<undef> disables it).
		806
		807	=cut
		808
		809	sub rbuf_max {
		810	$_[0]{rbuf_max} = $_[1];
		811	}
		812
		813	sub wbuf_max {
		814	$_[0]{wbuf_max} = $_[1];
		815	}
		816
		817	#############################################################################
		818
		819	=item $handle->timeout ($seconds)
		820
		821	=item $handle->rtimeout ($seconds)
		822
		823	=item $handle->wtimeout ($seconds)
		824
		825	Configures (or disables) the inactivity timeout.
		826
		827	The timeout will be checked instantly, so this method might destroy the
		828	handle before it returns.
		829
		830	=item $handle->timeout_reset
		831
		832	=item $handle->rtimeout_reset
		833
		834	=item $handle->wtimeout_reset
		835
		836	Reset the activity timeout, as if data was received or sent.
		837
		838	These methods are cheap to call.
		839
		840	=cut
		841
		842	for my $dir ("", "r", "w") {
		843	my $timeout = "${dir}timeout";
		844	my $tw = "_${dir}tw";
		845	my $on_timeout = "on_${dir}timeout";
		846	my $activity = "_${dir}activity";
		847	my $cb;
		848
		849	*$on_timeout = sub {
		850	$_[0]{$on_timeout} = $_[1];
		851	};
		852
		853	*$timeout = sub {
		854	my ($self, $new_value) = @_;
		855
		856	$new_value >= 0
		857	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		858
		859	$self->{$timeout} = $new_value;
		860	delete $self->{$tw}; &$cb;
		861	};
		862
		863	*{"${dir}timeout_reset"} = sub {
		864	$_[0]{$activity} = AE::now;
		865	};
		866
		867	# main workhorse:
		868	# reset the timeout watcher, as neccessary
		869	# also check for time-outs
		870	$cb = sub {
		871	my ($self) = @_;
		872
		873	if ($self->{$timeout} && $self->{fh}) {
		874	my $NOW = AE::now;
		875
		876	# when would the timeout trigger?
		877	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		878
		879	# now or in the past already?
		880	if ($after <= 0) {
		881	$self->{$activity} = $NOW;
		882
		883	if ($self->{$on_timeout}) {
		884	$self->{$on_timeout}($self);
		885	} else {
		886	$self->_error (Errno::ETIMEDOUT);
		887	}
		888
		889	# callback could have changed timeout value, optimise
		890	return unless $self->{$timeout};
		891
		892	# calculate new after
		893	$after = $self->{$timeout};
		894	}
		895
		896	Scalar::Util::weaken $self;
		897	return unless $self; # ->error could have destroyed $self
		898
		899	$self->{$tw} ||= AE::timer $after, 0, sub {
		900	delete $self->{$tw};
		901	$cb->($self);
36	chomp;	902	};
37	print "Line: $_";	903	} else {
		904	delete $self->{$tw};
		905	}
		906	}
		907	}
		908
		909	#############################################################################
		910
		911	=back
		912
		913	=head2 WRITE QUEUE
		914
		915	AnyEvent::Handle manages two queues per handle, one for writing and one
		916	for reading.
		917
		918	The write queue is very simple: you can add data to its end, and
		919	AnyEvent::Handle will automatically try to get rid of it for you.
		920
		921	When data could be written and the write buffer is shorter then the low
		922	water mark, the C<on_drain> callback will be invoked once.
		923
		924	=over 4
		925
		926	=item $handle->on_drain ($cb)
		927
		928	Sets the C<on_drain> callback or clears it (see the description of
		929	C<on_drain> in the constructor).
		930
		931	This method may invoke callbacks (and therefore the handle might be
		932	destroyed after it returns).
		933
		934	=cut
		935
		936	sub on_drain {
		937	my ($self, $cb) = @_;
		938
		939	$self->{on_drain} = $cb;
		940
		941	$cb->($self)
		942	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		943	}
		944
		945	=item $handle->push_write ($data)
		946
		947	Queues the given scalar to be written. You can push as much data as
		948	you want (only limited by the available memory and C<wbuf_max>), as
		949	C<AnyEvent::Handle> buffers it independently of the kernel.
		950
		951	This method may invoke callbacks (and therefore the handle might be
		952	destroyed after it returns).
		953
		954	=cut
		955
		956	sub _drain_wbuf {
		957	my ($self) = @_;
		958
		959	if (!$self->{_ww} && length $self->{wbuf}) {
		960
		961	Scalar::Util::weaken $self;
		962
		963	my $cb = sub {
		964	my $len = syswrite $self->{fh}, $self->{wbuf};
		965
		966	if (defined $len) {
		967	substr $self->{wbuf}, 0, $len, "";
		968
		969	$self->{_activity} = $self->{_wactivity} = AE::now;
		970
		971	$self->{on_drain}($self)
		972	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		973	&& $self->{on_drain};
		974
		975	delete $self->{_ww} unless length $self->{wbuf};
		976	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		977	$self->_error ($!, 1);
		978	}
		979	};
		980
		981	# try to write data immediately
		982	$cb->() unless $self->{autocork};
		983
		984	# if still data left in wbuf, we need to poll
		985	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		986	if length $self->{wbuf};
		987
		988	if (
		989	defined $self->{wbuf_max}
		990	&& $self->{wbuf_max} < length $self->{wbuf}
		991	) {
		992	$self->_error (Errno::ENOSPC, 1), return;
		993	}
		994	};
		995	}
		996
		997	our %WH;
		998
		999	# deprecated
		1000	sub register_write_type($$) {
		1001	$WH{$_[0]} = $_[1];
		1002	}
		1003
		1004	sub push_write {
		1005	my $self = shift;
		1006
		1007	if (@_ > 1) {
		1008	my $type = shift;
		1009
		1010	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		1011	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		1012	->($self, @_);
		1013	}
		1014
		1015	# we downgrade here to avoid hard-to-track-down bugs,
		1016	# and diagnose the problem earlier and better.
		1017
		1018	if ($self->{tls}) {
		1019	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		1020	&_dotls ($self) if $self->{fh};
		1021	} else {
		1022	utf8::downgrade $self->{wbuf} .= $_[0];
		1023	$self->_drain_wbuf if $self->{fh};
		1024	}
		1025	}
		1026
		1027	=item $handle->push_write (type => @args)
		1028
		1029	Instead of formatting your data yourself, you can also let this module
		1030	do the job by specifying a type and type-specific arguments. You
		1031	can also specify the (fully qualified) name of a package, in which
		1032	case AnyEvent tries to load the package and then expects to find the
		1033	C<anyevent_write_type> function inside (see "custom write types", below).
		1034
		1035	Predefined types are (if you have ideas for additional types, feel free to
		1036	drop by and tell us):
		1037
		1038	=over 4
		1039
		1040	=item netstring => $string
		1041
		1042	Formats the given value as netstring
		1043	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		1044
		1045	=cut
		1046
		1047	register_write_type netstring => sub {
		1048	my ($self, $string) = @_;
		1049
		1050	(length $string) . ":$string,"
		1051	};
		1052
		1053	=item packstring => $format, $data
		1054
		1055	An octet string prefixed with an encoded length. The encoding C<$format>
		1056	uses the same format as a Perl C<pack> format, but must specify a single
		1057	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1058	optional C<!>, C<< < >> or C<< > >> modifier).
		1059
		1060	=cut
		1061
		1062	register_write_type packstring => sub {
		1063	my ($self, $format, $string) = @_;
		1064
		1065	pack "$format/a*", $string
		1066	};
		1067
		1068	=item json => $array_or_hashref
		1069
		1070	Encodes the given hash or array reference into a JSON object. Unless you
		1071	provide your own JSON object, this means it will be encoded to JSON text
		1072	in UTF-8.
		1073
		1074	The default encoder might or might not handle every type of JSON value -
		1075	it might be limited to arrays and objects for security reasons. See the
		1076	C<json> constructor attribute for more details.
		1077
		1078	JSON objects (and arrays) are self-delimiting, so if you only use arrays
		1079	and hashes, you can write JSON at one end of a handle and read them at the
		1080	other end without using any additional framing.
		1081
		1082	The JSON text generated by the default encoder is guaranteed not to
		1083	contain any newlines: While this module doesn't need delimiters after or
		1084	between JSON texts to be able to read them, many other languages depend on
		1085	them.
		1086
		1087	A simple RPC protocol that interoperates easily with other languages is
		1088	to send JSON arrays (or objects, although arrays are usually the better
		1089	choice as they mimic how function argument passing works) and a newline
		1090	after each JSON text:
		1091
		1092	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1093	$handle->push_write ("\012");
		1094
		1095	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1096	rely on the fact that the newline will be skipped as leading whitespace:
		1097
		1098	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1099
		1100	Other languages could read single lines terminated by a newline and pass
		1101	this line into their JSON decoder of choice.
		1102
		1103	=item cbor => $perl_scalar
		1104
		1105	Encodes the given scalar into a CBOR value. Unless you provide your own
		1106	L<CBOR::XS> object, this means it will be encoded to a CBOR string not
		1107	using any extensions, if possible.
		1108
		1109	CBOR values are self-delimiting, so you can write CBOR at one end of
		1110	a handle and read them at the other end without using any additional
		1111	framing.
		1112
		1113	A simple nd very very fast RPC protocol that interoperates with
		1114	other languages is to send CBOR and receive CBOR values (arrays are
		1115	recommended):
		1116
		1117	$handle->push_write (cbor => ["method", "arg1", "arg2"]); # whatever
		1118
		1119	An AnyEvent::Handle receiver would simply use the C<cbor> read type:
		1120
		1121	$handle->push_read (cbor => sub { my $array = $_[1]; ... });
		1122
		1123	=cut
		1124
		1125	sub json_coder() {
		1126	eval { require JSON::XS; JSON::XS->new->utf8 }
		1127	|| do { require JSON::PP; JSON::PP->new->utf8 }
		1128	}
		1129
		1130	register_write_type json => sub {
		1131	my ($self, $ref) = @_;
		1132
		1133	($self->{json} ||= json_coder)
		1134	->encode ($ref)
		1135	};
		1136
		1137	sub cbor_coder() {
		1138	require CBOR::XS;
		1139	CBOR::XS->new
		1140	}
		1141
		1142	register_write_type cbor => sub {
		1143	my ($self, $scalar) = @_;
		1144
		1145	($self->{cbor} ||= cbor_coder)
		1146	->encode ($scalar)
		1147	};
		1148
		1149	=item storable => $reference
		1150
		1151	Freezes the given reference using L<Storable> and writes it to the
		1152	handle. Uses the C<nfreeze> format.
		1153
		1154	=cut
		1155
		1156	register_write_type storable => sub {
		1157	my ($self, $ref) = @_;
		1158
		1159	require Storable unless $Storable::VERSION;
		1160
		1161	pack "w/a*", Storable::nfreeze ($ref)
		1162	};
		1163
		1164	=back
		1165
		1166	=item $handle->push_shutdown
		1167
		1168	Sometimes you know you want to close the socket after writing your data
		1169	before it was actually written. One way to do that is to replace your
		1170	C<on_drain> handler by a callback that shuts down the socket (and set
		1171	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1172	replaces the C<on_drain> callback with:
		1173
		1174	sub { shutdown $_[0]{fh}, 1 }
		1175
		1176	This simply shuts down the write side and signals an EOF condition to the
		1177	the peer.
		1178
		1179	You can rely on the normal read queue and C<on_eof> handling
		1180	afterwards. This is the cleanest way to close a connection.
		1181
		1182	This method may invoke callbacks (and therefore the handle might be
		1183	destroyed after it returns).
		1184
		1185	=cut
		1186
		1187	sub push_shutdown {
		1188	my ($self) = @_;
		1189
		1190	delete $self->{low_water_mark};
		1191	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1192	}
		1193
		1194	=item custom write types - Package::anyevent_write_type $handle, @args
		1195
		1196	Instead of one of the predefined types, you can also specify the name of
		1197	a package. AnyEvent will try to load the package and then expects to find
		1198	a function named C<anyevent_write_type> inside. If it isn't found, it
		1199	progressively tries to load the parent package until it either finds the
		1200	function (good) or runs out of packages (bad).
		1201
		1202	Whenever the given C<type> is used, C<push_write> will the function with
		1203	the handle object and the remaining arguments.
		1204
		1205	The function is supposed to return a single octet string that will be
		1206	appended to the write buffer, so you can mentally treat this function as a
		1207	"arguments to on-the-wire-format" converter.
		1208
		1209	Example: implement a custom write type C<join> that joins the remaining
		1210	arguments using the first one.
		1211
		1212	$handle->push_write (My::Type => " ", 1,2,3);
		1213
		1214	# uses the following package, which can be defined in the "My::Type" or in
		1215	# the "My" modules to be auto-loaded, or just about anywhere when the
		1216	# My::Type::anyevent_write_type is defined before invoking it.
		1217
		1218	package My::Type;
		1219
		1220	sub anyevent_write_type {
		1221	my ($handle, $delim, @args) = @_;
		1222
		1223	join $delim, @args
		1224	}
		1225
		1226	=cut
		1227
		1228	#############################################################################
		1229
		1230	=back
		1231
		1232	=head2 READ QUEUE
		1233
		1234	AnyEvent::Handle manages two queues per handle, one for writing and one
		1235	for reading.
		1236
		1237	The read queue is more complex than the write queue. It can be used in two
		1238	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1239	a queue.
		1240
		1241	In the simple case, you just install an C<on_read> callback and whenever
		1242	new data arrives, it will be called. You can then remove some data (if
		1243	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
		1244	leave the data there if you want to accumulate more (e.g. when only a
		1245	partial message has been received so far), or change the read queue with
		1246	e.g. C<push_read>.
		1247
		1248	In the more complex case, you want to queue multiple callbacks. In this
		1249	case, AnyEvent::Handle will call the first queued callback each time new
		1250	data arrives (also the first time it is queued) and remove it when it has
		1251	done its job (see C<push_read>, below).
		1252
		1253	This way you can, for example, push three line-reads, followed by reading
		1254	a chunk of data, and AnyEvent::Handle will execute them in order.
		1255
		1256	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1257	the specified number of bytes which give an XML datagram.
		1258
		1259	# in the default state, expect some header bytes
		1260	$handle->on_read (sub {
		1261	# some data is here, now queue the length-header-read (4 octets)
		1262	shift->unshift_read (chunk => 4, sub {
		1263	# header arrived, decode
		1264	my $len = unpack "N", $_[1];
		1265
		1266	# now read the payload
		1267	shift->unshift_read (chunk => $len, sub {
		1268	my $xml = $_[1];
		1269	# handle xml
		1270	});
		1271	});
		1272	});
		1273
		1274	Example 2: Implement a client for a protocol that replies either with "OK"
		1275	and another line or "ERROR" for the first request that is sent, and 64
		1276	bytes for the second request. Due to the availability of a queue, we can
		1277	just pipeline sending both requests and manipulate the queue as necessary
		1278	in the callbacks.
		1279
		1280	When the first callback is called and sees an "OK" response, it will
		1281	C<unshift> another line-read. This line-read will be queued I<before> the
		1282	64-byte chunk callback.
		1283
		1284	# request one, returns either "OK + extra line" or "ERROR"
		1285	$handle->push_write ("request 1\015\012");
		1286
		1287	# we expect "ERROR" or "OK" as response, so push a line read
		1288	$handle->push_read (line => sub {
		1289	# if we got an "OK", we have to _prepend_ another line,
		1290	# so it will be read before the second request reads its 64 bytes
		1291	# which are already in the queue when this callback is called
		1292	# we don't do this in case we got an error
		1293	if ($_[1] eq "OK") {
		1294	$_[0]->unshift_read (line => sub {
		1295	my $response = $_[1];
		1296	...
		1297	});
38	}	1298	}
39	});	1299	});
40		1300
41	# or use the constructor to pass the callback:	1301	# request two, simply returns 64 octets
		1302	$handle->push_write ("request 2\015\012");
42		1303
43	my $ae_fh2 =	1304	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1305	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1306	my $response = $_[1];
46	on_eof => sub {	1307	...
47	$cv->broadcast;	1308	});
48	},	1309
49	on_readline => sub {	1310	=over 4
50	my ($ae_fh, @lines) = @_;	1311
51	for (@lines) {	1312	=cut
52	chomp;	1313
53	print "Line: $_";	1314	sub _drain_rbuf {
		1315	my ($self) = @_;
		1316
		1317	# avoid recursion
		1318	return if $self->{_skip_drain_rbuf};
		1319	local $self->{_skip_drain_rbuf} = 1;
		1320
		1321	while () {
		1322	# we need to use a separate tls read buffer, as we must not receive data while
		1323	# we are draining the buffer, and this can only happen with TLS.
		1324	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1325	if exists $self->{_tls_rbuf};
		1326
		1327	my $len = length $self->{rbuf};
		1328
		1329	if (my $cb = shift @{ $self->{_queue} }) {
		1330	unless ($cb->($self)) {
		1331	# no progress can be made
		1332	# (not enough data and no data forthcoming)
		1333	$self->_error (Errno::EPIPE, 1), return
		1334	if $self->{_eof};
		1335
		1336	unshift @{ $self->{_queue} }, $cb;
54	}	1337	last;
55	}	1338	}
56	);
57
58	$cv->wait;
59
60	=head1 DESCRIPTION
61
62	This module is a helper module to make it easier to do non-blocking I/O
63	on filehandles (and sockets, see L<AnyEvent::Socket>).
64
65	The event loop is provided by L<AnyEvent>.
66
67	=head1 METHODS
68
69	=over 4
70
71	=item B<new (%args)>
72
73	The constructor has these arguments:
74
75	=over 4
76
77	=item fh => $filehandle
78
79	The filehandle this L<AnyEvent::Handle> object will operate on.
80
81	NOTE: The filehandle will be set to non-blocking.
82
83	=item read_block_size => $size
84
85	The default read block size use for reads via the C<on_read>
86	method.
87
88	=item on_read => $cb
89
90	=item on_eof => $cb
91
92	=item on_error => $cb
93
94	These are shortcuts, that will call the corresponding method and set the callback to C<$cb>.
95
96	=item on_readline => $cb
97
98	The C<readlines> method is called with the default seperator and C<$cb> as callback
99	for you.
100
101	=back
102
103	=cut
104
105	sub new {
106	my $this = shift;
107	my $class = ref($this) || $this;
108	my $self = {
109	read_block_size => 4096,
110	rbuf => '',
111	@_
112	};
113	bless $self, $class;
114
115	$self->{fh}->blocking (0) if $self->{fh};
116
117	if ($self->{on_read}) {
118	$self->on_read ($self->{on_read});
119
120	} elsif ($self->{on_readline}) {	1339	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1340	last unless $len;
122		1341
		1342	$self->{on_read}($self);
		1343
		1344	if (
		1345	$len == length $self->{rbuf} # if no data has been consumed
		1346	&& !@{ $self->{_queue} } # and the queue is still empty
		1347	&& $self->{on_read} # but we still have on_read
		1348	) {
		1349	# no further data will arrive
		1350	# so no progress can be made
		1351	$self->_error (Errno::EPIPE, 1), return
		1352	if $self->{_eof};
		1353
		1354	last; # more data might arrive
		1355	}
		1356	} else {
		1357	# read side becomes idle
		1358	delete $self->{_rw} unless $self->{tls};
		1359	last;
		1360	}
		1361	}
		1362
123	} elsif ($self->{on_eof}) {	1363	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1364	$self->{on_eof}
		1365	? $self->{on_eof}($self)
		1366	: $self->_error (0, 1, "Unexpected end-of-file");
125		1367
126	} elsif ($self->{on_error}) {	1368	return;
127	$self->on_eof ($self->{on_error});
128	}	1369	}
129		1370
130	return $self	1371	if (
131	}	1372	defined $self->{rbuf_max}
		1373	&& $self->{rbuf_max} < length $self->{rbuf}
		1374	) {
		1375	$self->_error (Errno::ENOSPC, 1), return;
		1376	}
132		1377
133	=item B<fh>	1378	# may need to restart read watcher
		1379	unless ($self->{_rw}) {
		1380	$self->start_read
		1381	if $self->{on_read} || @{ $self->{_queue} };
		1382	}
		1383	}
134		1384
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1385	=item $handle->on_read ($cb)
136		1386
137	=cut	1387	This replaces the currently set C<on_read> callback, or clears it (when
		1388	the new callback is C<undef>). See the description of C<on_read> in the
		1389	constructor.
138		1390
139	sub fh { $_[0]->{fh} }	1391	This method may invoke callbacks (and therefore the handle might be
140		1392	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		1393
149	=cut	1394	=cut
150		1395
151	sub on_read {	1396	sub on_read {
152	my ($self, $cb) = @_;	1397	my ($self, $cb) = @_;
		1398
153	$self->{on_read} = $cb;	1399	$self->{on_read} = $cb;
		1400	$self->_drain_rbuf if $cb;
		1401	}
154		1402
155	unless (defined $self->{on_read}) {	1403	=item $handle->rbuf
156	delete $self->{on_read_w};	1404
		1405	Returns the read buffer (as a modifiable lvalue). You can also access the
		1406	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1407	much faster, and no less clean).
		1408
		1409	The only operation allowed on the read buffer (apart from looking at it)
		1410	is removing data from its beginning. Otherwise modifying or appending to
		1411	it is not allowed and will lead to hard-to-track-down bugs.
		1412
		1413	NOTE: The read buffer should only be used or modified in the C<on_read>
		1414	callback or when C<push_read> or C<unshift_read> are used with a single
		1415	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1416	will manage the read buffer on their own.
		1417
		1418	=cut
		1419
		1420	sub rbuf : lvalue {
		1421	$_[0]{rbuf}
		1422	}
		1423
		1424	=item $handle->push_read ($cb)
		1425
		1426	=item $handle->unshift_read ($cb)
		1427
		1428	Append the given callback to the end of the queue (C<push_read>) or
		1429	prepend it (C<unshift_read>).
		1430
		1431	The callback is called each time some additional read data arrives.
		1432
		1433	It must check whether enough data is in the read buffer already.
		1434
		1435	If not enough data is available, it must return the empty list or a false
		1436	value, in which case it will be called repeatedly until enough data is
		1437	available (or an error condition is detected).
		1438
		1439	If enough data was available, then the callback must remove all data it is
		1440	interested in (which can be none at all) and return a true value. After returning
		1441	true, it will be removed from the queue.
		1442
		1443	These methods may invoke callbacks (and therefore the handle might be
		1444	destroyed after it returns).
		1445
		1446	=cut
		1447
		1448	our %RH;
		1449
		1450	sub register_read_type($$) {
		1451	$RH{$_[0]} = $_[1];
		1452	}
		1453
		1454	sub push_read {
		1455	my $self = shift;
		1456	my $cb = pop;
		1457
		1458	if (@_) {
		1459	my $type = shift;
		1460
		1461	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1462	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1463	->($self, $cb, @_);
		1464	}
		1465
		1466	push @{ $self->{_queue} }, $cb;
		1467	$self->_drain_rbuf;
		1468	}
		1469
		1470	sub unshift_read {
		1471	my $self = shift;
		1472	my $cb = pop;
		1473
		1474	if (@_) {
		1475	my $type = shift;
		1476
		1477	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1478	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
		1479	->($self, $cb, @_);
		1480	}
		1481
		1482	unshift @{ $self->{_queue} }, $cb;
		1483	$self->_drain_rbuf;
		1484	}
		1485
		1486	=item $handle->push_read (type => @args, $cb)
		1487
		1488	=item $handle->unshift_read (type => @args, $cb)
		1489
		1490	Instead of providing a callback that parses the data itself you can chose
		1491	between a number of predefined parsing formats, for chunks of data, lines
		1492	etc. You can also specify the (fully qualified) name of a package, in
		1493	which case AnyEvent tries to load the package and then expects to find the
		1494	C<anyevent_read_type> function inside (see "custom read types", below).
		1495
		1496	Predefined types are (if you have ideas for additional types, feel free to
		1497	drop by and tell us):
		1498
		1499	=over 4
		1500
		1501	=item chunk => $octets, $cb->($handle, $data)
		1502
		1503	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1504	data read to the callback. The callback will never be called with less
		1505	data.
		1506
		1507	Example: read 2 bytes.
		1508
		1509	$handle->push_read (chunk => 2, sub {
		1510	say "yay " . unpack "H*", $_[1];
		1511	});
		1512
		1513	=cut
		1514
		1515	register_read_type chunk => sub {
		1516	my ($self, $cb, $len) = @_;
		1517
		1518	sub {
		1519	$len <= length $_[0]{rbuf} or return;
		1520	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1521	1
		1522	}
		1523	};
		1524
		1525	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1526
		1527	The callback will be called only once a full line (including the end of
		1528	line marker, C<$eol>) has been read. This line (excluding the end of line
		1529	marker) will be passed to the callback as second argument (C<$line>), and
		1530	the end of line marker as the third argument (C<$eol>).
		1531
		1532	The end of line marker, C<$eol>, can be either a string, in which case it
		1533	will be interpreted as a fixed record end marker, or it can be a regex
		1534	object (e.g. created by C<qr>), in which case it is interpreted as a
		1535	regular expression.
		1536
		1537	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1538	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1539	protocols).
		1540
		1541	Partial lines at the end of the stream will never be returned, as they are
		1542	not marked by the end of line marker.
		1543
		1544	=cut
		1545
		1546	register_read_type line => sub {
		1547	my ($self, $cb, $eol) = @_;
		1548
		1549	if (@_ < 3) {
		1550	# this is faster then the generic code below
		1551	sub {
		1552	(my $pos = index $_[0]{rbuf}, "\012") >= 0
		1553	or return;
		1554
		1555	(my $str = substr $_[0]{rbuf}, 0, $pos + 1, "") =~ s/(\015?\012)\Z// or die;
		1556	$cb->($_[0], $str, "$1");
		1557	1
		1558	}
		1559	} else {
		1560	$eol = quotemeta $eol unless ref $eol;
		1561	$eol = qr|^(.*?)($eol)|s;
		1562
		1563	sub {
		1564	$_[0]{rbuf} =~ s/$eol// or return;
		1565
		1566	$cb->($_[0], "$1", "$2");
		1567	1
		1568	}
		1569	}
		1570	};
		1571
		1572	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1573
		1574	Makes a regex match against the regex object C<$accept> and returns
		1575	everything up to and including the match.
		1576
		1577	Example: read a single line terminated by '\n'.
		1578
		1579	$handle->push_read (regex => qr<\n>, sub { ... });
		1580
		1581	If C<$reject> is given and not undef, then it determines when the data is
		1582	to be rejected: it is matched against the data when the C<$accept> regex
		1583	does not match and generates an C<EBADMSG> error when it matches. This is
		1584	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1585	receive buffer overflow).
		1586
		1587	Example: expect a single decimal number followed by whitespace, reject
		1588	anything else (not the use of an anchor).
		1589
		1590	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1591
		1592	If C<$skip> is given and not C<undef>, then it will be matched against
		1593	the receive buffer when neither C<$accept> nor C<$reject> match,
		1594	and everything preceding and including the match will be accepted
		1595	unconditionally. This is useful to skip large amounts of data that you
		1596	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1597	have to start matching from the beginning. This is purely an optimisation
		1598	and is usually worth it only when you expect more than a few kilobytes.
		1599
		1600	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1601	expect the header to be very large (it isn't in practice, but...), we use
		1602	a skip regex to skip initial portions. The skip regex is tricky in that
		1603	it only accepts something not ending in either \015 or \012, as these are
		1604	required for the accept regex.
		1605
		1606	$handle->push_read (regex =>
		1607	qr<\015\012\015\012>,
		1608	undef, # no reject
		1609	qr<^.*[^\015\012]>,
		1610	sub { ... });
		1611
		1612	=cut
		1613
		1614	register_read_type regex => sub {
		1615	my ($self, $cb, $accept, $reject, $skip) = @_;
		1616
		1617	my $data;
		1618	my $rbuf = \$self->{rbuf};
		1619
		1620	sub {
		1621	# accept
		1622	if ($$rbuf =~ $accept) {
		1623	$data .= substr $$rbuf, 0, $+[0], "";
		1624	$cb->($_[0], $data);
		1625	return 1;
		1626	}
		1627
		1628	# reject
		1629	if ($reject && $$rbuf =~ $reject) {
		1630	$_[0]->_error (Errno::EBADMSG);
		1631	}
		1632
		1633	# skip
		1634	if ($skip && $$rbuf =~ $skip) {
		1635	$data .= substr $$rbuf, 0, $+[0], "";
		1636	}
		1637
		1638	()
		1639	}
		1640	};
		1641
		1642	=item netstring => $cb->($handle, $string)
		1643
		1644	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1645
		1646	Throws an error with C<$!> set to EBADMSG on format violations.
		1647
		1648	=cut
		1649
		1650	register_read_type netstring => sub {
		1651	my ($self, $cb) = @_;
		1652
		1653	sub {
		1654	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1655	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1656	$_[0]->_error (Errno::EBADMSG);
		1657	}
157	return;	1658	return;
		1659	}
		1660
		1661	my $len = $1;
		1662
		1663	$_[0]->unshift_read (chunk => $len, sub {
		1664	my $string = $_[1];
		1665	$_[0]->unshift_read (chunk => 1, sub {
		1666	if ($_[1] eq ",") {
		1667	$cb->($_[0], $string);
		1668	} else {
		1669	$_[0]->_error (Errno::EBADMSG);
		1670	}
		1671	});
		1672	});
		1673
		1674	1
		1675	}
		1676	};
		1677
		1678	=item packstring => $format, $cb->($handle, $string)
		1679
		1680	An octet string prefixed with an encoded length. The encoding C<$format>
		1681	uses the same format as a Perl C<pack> format, but must specify a single
		1682	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1683	optional C<!>, C<< < >> or C<< > >> modifier).
		1684
		1685	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1686	EPP uses a prefix of C<N> (4 octtes).
		1687
		1688	Example: read a block of data prefixed by its length in BER-encoded
		1689	format (very efficient).
		1690
		1691	$handle->push_read (packstring => "w", sub {
		1692	my ($handle, $data) = @_;
		1693	});
		1694
		1695	=cut
		1696
		1697	register_read_type packstring => sub {
		1698	my ($self, $cb, $format) = @_;
		1699
		1700	sub {
		1701	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1702	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1703	or return;
		1704
		1705	$format = length pack $format, $len;
		1706
		1707	# bypass unshift if we already have the remaining chunk
		1708	if ($format + $len <= length $_[0]{rbuf}) {
		1709	my $data = substr $_[0]{rbuf}, $format, $len;
		1710	substr $_[0]{rbuf}, 0, $format + $len, "";
		1711	$cb->($_[0], $data);
		1712	} else {
		1713	# remove prefix
		1714	substr $_[0]{rbuf}, 0, $format, "";
		1715
		1716	# read remaining chunk
		1717	$_[0]->unshift_read (chunk => $len, $cb);
		1718	}
		1719
		1720	1
		1721	}
		1722	};
		1723
		1724	=item json => $cb->($handle, $hash_or_arrayref)
		1725
		1726	Reads a JSON object or array, decodes it and passes it to the
		1727	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1728
		1729	If a C<json> object was passed to the constructor, then that will be
		1730	used for the final decode, otherwise it will create a L<JSON::XS> or
		1731	L<JSON::PP> coder object expecting UTF-8.
		1732
		1733	This read type uses the incremental parser available with JSON version
		1734	2.09 (and JSON::XS version 2.2) and above.
		1735
		1736	Since JSON texts are fully self-delimiting, the C<json> read and write
		1737	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1738	the C<json> write type description, above, for an actual example.
		1739
		1740	=cut
		1741
		1742	register_read_type json => sub {
		1743	my ($self, $cb) = @_;
		1744
		1745	my $json = $self->{json} ||= json_coder;
		1746
		1747	my $data;
		1748
		1749	sub {
		1750	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
		1751
		1752	if ($ref) {
		1753	$_[0]{rbuf} = $json->incr_text;
		1754	$json->incr_text = "";
		1755	$cb->($_[0], $ref);
		1756
		1757	1
		1758	} elsif ($@) {
		1759	# error case
		1760	$json->incr_skip;
		1761
		1762	$_[0]{rbuf} = $json->incr_text;
		1763	$json->incr_text = "";
		1764
		1765	$_[0]->_error (Errno::EBADMSG);
		1766
		1767	()
		1768	} else {
		1769	$_[0]{rbuf} = "";
		1770
		1771	()
		1772	}
		1773	}
		1774	};
		1775
		1776	=item cbor => $cb->($handle, $scalar)
		1777
		1778	Reads a CBOR value, decodes it and passes it to the callback. When a parse
		1779	error occurs, an C<EBADMSG> error will be raised.
		1780
		1781	If a L<CBOR::XS> object was passed to the constructor, then that will be
		1782	used for the final decode, otherwise it will create a CBOR coder without
		1783	enabling any options.
		1784
		1785	You have to provide a dependency to L<CBOR::XS> on your own: this module
		1786	will load the L<CBOR::XS> module, but AnyEvent does not depend on it
		1787	itself.
		1788
		1789	Since CBOR values are fully self-delimiting, the C<cbor> read and write
		1790	types are an ideal simple RPC protocol: just exchange CBOR datagrams. See
		1791	the C<cbor> write type description, above, for an actual example.
		1792
		1793	=cut
		1794
		1795	register_read_type cbor => sub {
		1796	my ($self, $cb) = @_;
		1797
		1798	my $cbor = $self->{cbor} ||= cbor_coder;
		1799
		1800	my $data;
		1801
		1802	sub {
		1803	my (@value) = eval { $cbor->incr_parse ($_[0]{rbuf}) };
		1804
		1805	if (@value) {
		1806	$cb->($_[0], @value);
		1807
		1808	1
		1809	} elsif ($@) {
		1810	# error case
		1811	$cbor->incr_reset;
		1812
		1813	$_[0]->_error (Errno::EBADMSG);
		1814
		1815	()
		1816	} else {
		1817	()
		1818	}
		1819	}
		1820	};
		1821
		1822	=item storable => $cb->($handle, $ref)
		1823
		1824	Deserialises a L<Storable> frozen representation as written by the
		1825	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1826	data).
		1827
		1828	Raises C<EBADMSG> error if the data could not be decoded.
		1829
		1830	=cut
		1831
		1832	register_read_type storable => sub {
		1833	my ($self, $cb) = @_;
		1834
		1835	require Storable unless $Storable::VERSION;
		1836
		1837	sub {
		1838	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1839	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1840	or return;
		1841
		1842	my $format = length pack "w", $len;
		1843
		1844	# bypass unshift if we already have the remaining chunk
		1845	if ($format + $len <= length $_[0]{rbuf}) {
		1846	my $data = substr $_[0]{rbuf}, $format, $len;
		1847	substr $_[0]{rbuf}, 0, $format + $len, "";
		1848
		1849	eval { $cb->($_[0], Storable::thaw ($data)); 1 }
		1850	or return $_[0]->_error (Errno::EBADMSG);
		1851	} else {
		1852	# remove prefix
		1853	substr $_[0]{rbuf}, 0, $format, "";
		1854
		1855	# read remaining chunk
		1856	$_[0]->unshift_read (chunk => $len, sub {
		1857	eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
		1858	or $_[0]->_error (Errno::EBADMSG);
		1859	});
		1860	}
		1861
		1862	1
		1863	}
		1864	};
		1865
		1866	=item tls_detect => $cb->($handle, $detect, $major, $minor)
		1867
		1868	Checks the input stream for a valid SSL or TLS handshake TLSPaintext
		1869	record without consuming anything. Only SSL version 3 or higher
		1870	is handled, up to the fictituous protocol 4.x (but both SSL3+ and
		1871	SSL2-compatible framing is supported).
		1872
		1873	If it detects that the input data is likely TLS, it calls the callback
		1874	with a true value for C<$detect> and the (on-wire) TLS version as second
		1875	and third argument (C<$major> is C<3>, and C<$minor> is 0..3 for SSL
		1876	3.0, TLS 1.0, 1.1 and 1.2, respectively). If it detects the input to
		1877	be definitely not TLS, it calls the callback with a false value for
		1878	C<$detect>.
		1879
		1880	The callback could use this information to decide whether or not to start
		1881	TLS negotiation.
		1882
		1883	In all cases the data read so far is passed to the following read
		1884	handlers.
		1885
		1886	Usually you want to use the C<tls_autostart> read type instead.
		1887
		1888	If you want to design a protocol that works in the presence of TLS
		1889	dtection, make sure that any non-TLS data doesn't start with the octet 22
		1890	(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
		1891	read type does are a bit more strict, but might losen in the future to
		1892	accomodate protocol changes.
		1893
		1894	This read type does not rely on L<AnyEvent::TLS> (and thus, not on
		1895	L<Net::SSLeay>).
		1896
		1897	=item tls_autostart => $tls[, $tls_ctx]
		1898
		1899	Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
		1900	to start tls by calling C<starttls> with the given arguments.
		1901
		1902	In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
		1903	been configured to accept, as servers do not normally send a handshake on
		1904	their own and ths cannot be detected in this way.
		1905
		1906	See C<tls_detect> above for more details.
		1907
		1908	Example: give the client a chance to start TLS before accepting a text
		1909	line.
		1910
		1911	$hdl->push_read (tls_detect => "accept");
		1912	$hdl->push_read (line => sub {
		1913	print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
		1914	});
		1915
		1916	=cut
		1917
		1918	register_read_type tls_detect => sub {
		1919	my ($self, $cb) = @_;
		1920
		1921	sub {
		1922	# this regex matches a full or partial tls record
		1923	if (
		1924	# ssl3+: type(22=handshake) major(=3) minor(any) length_hi
		1925	$self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
		1926	# ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
		1927	or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
		1928	) {
		1929	return if 3 != length $1; # partial match, can't decide yet
		1930
		1931	# full match, valid TLS record
		1932	my ($major, $minor) = unpack "CC", $1;
		1933	$cb->($self, "accept", $major + $minor * 0.1);
		1934	} else {
		1935	# mismatch == guaranteed not TLS
		1936	$cb->($self, undef);
		1937	}
		1938
		1939	1
		1940	}
		1941	};
		1942
		1943	register_read_type tls_autostart => sub {
		1944	my ($self, @tls) = @_;
		1945
		1946	$RH{tls_detect}($self, sub {
		1947	return unless $_[1];
		1948	$_[0]->starttls (@tls);
158	}	1949	})
159		1950	};
160	$self->{on_read_w} =	1951
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1952	=back
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1953
163	my $rbuf_len = length $self->{rbuf};	1954	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
164	my $l;	1955
		1956	Instead of one of the predefined types, you can also specify the name
		1957	of a package. AnyEvent will try to load the package and then expects to
		1958	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1959	progressively tries to load the parent package until it either finds the
		1960	function (good) or runs out of packages (bad).
		1961
		1962	Whenever this type is used, C<push_read> will invoke the function with the
		1963	handle object, the original callback and the remaining arguments.
		1964
		1965	The function is supposed to return a callback (usually a closure) that
		1966	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1967	mentally treat the function as a "configurable read type to read callback"
		1968	converter.
		1969
		1970	It should invoke the original callback when it is done reading (remember
		1971	to pass C<$handle> as first argument as all other callbacks do that,
		1972	although there is no strict requirement on this).
		1973
		1974	For examples, see the source of this module (F<perldoc -m
		1975	AnyEvent::Handle>, search for C<register_read_type>)).
		1976
		1977	=item $handle->stop_read
		1978
		1979	=item $handle->start_read
		1980
		1981	In rare cases you actually do not want to read anything from the
		1982	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1983	any queued callbacks will be executed then. To start reading again, call
		1984	C<start_read>.
		1985
		1986	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1987	you change the C<on_read> callback or push/unshift a read callback, and it
		1988	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1989	there are any read requests in the queue.
		1990
		1991	In older versions of this module (<= 5.3), these methods had no effect,
		1992	as TLS does not support half-duplex connections. In current versions they
		1993	work as expected, as this behaviour is required to avoid certain resource
		1994	attacks, where the program would be forced to read (and buffer) arbitrary
		1995	amounts of data before being able to send some data. The drawback is that
		1996	some readings of the the SSL/TLS specifications basically require this
		1997	attack to be working, as SSL/TLS implementations might stall sending data
		1998	during a rehandshake.
		1999
		2000	As a guideline, during the initial handshake, you should not stop reading,
		2001	and as a client, it might cause problems, depending on your application.
		2002
		2003	=cut
		2004
		2005	sub stop_read {
		2006	my ($self) = @_;
		2007
		2008	delete $self->{_rw};
		2009	}
		2010
		2011	sub start_read {
		2012	my ($self) = @_;
		2013
		2014	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		2015	Scalar::Util::weaken $self;
		2016
		2017	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		2018	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		2019	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
		2020
		2021	if ($len > 0) {
		2022	$self->{_activity} = $self->{_ractivity} = AE::now;
		2023
		2024	if ($self->{tls}) {
		2025	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		2026
		2027	&_dotls ($self);
		2028	} else {
		2029	$self->_drain_rbuf;
		2030	}
		2031
165	if (defined $self->{read_size}) {	2032	if ($len == $self->{read_size}) {
166	$l = sysread $self->{fh}, $self->{rbuf},	2033	$self->{read_size} *= 2;
167	($self->{read_size} - $rbuf_len), $rbuf_len;	2034	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		2035	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		2036	}
		2037
		2038	} elsif (defined $len) {
		2039	delete $self->{_rw};
		2040	$self->{_eof} = 1;
		2041	$self->_drain_rbuf;
		2042
		2043	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		2044	return $self->_error ($!, 1);
		2045	}
		2046	};
		2047	}
		2048	}
		2049
		2050	our $ERROR_SYSCALL;
		2051	our $ERROR_WANT_READ;
		2052
		2053	sub _tls_error {
		2054	my ($self, $err) = @_;
		2055
		2056	return $self->_error ($!, 1)
		2057	if $err == Net::SSLeay::ERROR_SYSCALL ();
		2058
		2059	my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		2060
		2061	# reduce error string to look less scary
		2062	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		2063
		2064	if ($self->{_on_starttls}) {
		2065	(delete $self->{_on_starttls})->($self, undef, $err);
		2066	&_freetls;
		2067	} else {
		2068	&_freetls;
		2069	$self->_error (Errno::EPROTO, 1, $err);
		2070	}
		2071	}
		2072
		2073	# poll the write BIO and send the data if applicable
		2074	# also decode read data if possible
		2075	# this is basiclaly our TLS state machine
		2076	# more efficient implementations are possible with openssl,
		2077	# but not with the buggy and incomplete Net::SSLeay.
		2078	sub _dotls {
		2079	my ($self) = @_;
		2080
		2081	my $tmp;
		2082
		2083	while (length $self->{_tls_wbuf}) {
		2084	if (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) <= 0) {
		2085	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		2086
		2087	return $self->_tls_error ($tmp)
		2088	if $tmp != $ERROR_WANT_READ
		2089	&& ($tmp != $ERROR_SYSCALL || $!);
		2090
		2091	last;
		2092	}
		2093
		2094	substr $self->{_tls_wbuf}, 0, $tmp, "";
		2095	}
		2096
		2097	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		2098	unless (length $tmp) {
		2099	$self->{_on_starttls}
		2100	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		2101	&_freetls;
		2102
		2103	if ($self->{on_stoptls}) {
		2104	$self->{on_stoptls}($self);
		2105	return;
168	} else {	2106	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	2107	# 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};	2108	delete $self->{_rw};
177
178	} elsif ($l == 0) {
179	$self->{on_eof}->($self) if $self->{on_eof};
180	delete $self->{on_read_w};
181
182	} else {
183	$self->{on_read}->($self);
184	}
185	});
186	}
187
188	=item B<on_error ($callback)>
189
190	Whenever a read or write operation resulted in an error the C<$callback>
191	will be called.
192
193	The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself.
194	The error is given as errno in C<$!>.
195
196	=cut
197
198	sub on_error {
199	$_[0]->{on_error} = $_[1];
200	}
201
202	=item B<on_eof ($callback)>
203
204	Installs the C<$callback> that will be called when the end of file is
205	encountered in a read operation this C<$callback> will be called. The first
206	argument will be the L<AnyEvent::Handle> object itself.
207
208	=cut
209
210	sub on_eof {
211	$_[0]->{on_eof} = $_[1];
212	}
213
214	=item B<rbuf>
215
216	Returns a reference to the read buffer.
217
218	NOTE: The read buffer should only be used or modified if the C<on_read>
219	method is used directly. The C<read> and C<readlines> methods will provide
220	the read data to their callbacks.
221
222	=cut
223
224	sub rbuf : lvalue {
225	$_[0]->{rbuf}
226	}
227
228	=item B<read ($len, $callback)>
229
230	Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
231	if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
232	object itself and the second argument the read data.
233
234	NOTE: This method will override any callbacks installed via the C<on_read> method.
235
236	=cut
237
238	sub read {
239	my ($self, $len, $cb) = @_;
240
241	$self->{read_cb} = $cb;
242	my $old_blk_size = $self->{read_block_size};
243	$self->{read_block_size} = $len;
244
245	$self->on_read (sub {
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247
248	if ($len == length $_[0]->{rbuf}) {
249	$_[0]->{read_block_size} = $old_blk_size;
250	$_[0]->on_read (undef);
251	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
252	}
253	});
254	}
255
256	=item B<readlines ($callback)>
257
258	=item B<readlines ($sep, $callback)>
259
260	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
261	if C<$sep> is not provided. C<$sep> will be used as part of a regex, so it can be
262	a regex itself and won't be quoted!
263
264	The C<$callback> will be called when at least one
265	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
266	object itself and the rest of the arguments will be the read lines.
267
268	NOTE: This method will override any callbacks installed via the C<on_read> method.
269
270	=cut
271
272	sub readlines {
273	my ($self, $NL, $cb) = @_;
274
275	if (ref $NL) {
276	$cb = $NL;
277	$NL = "\n";
278	}
279
280	$self->{on_readline} = $cb;
281
282	$self->on_read (sub {
283	my @lines;
284	push @lines, $1 while $_[0]->{rbuf} =~ s/(.*)$NL//;
285	$self->{on_readline}->($_[0], @lines);
286	});
287	}
288
289	=item B<write ($data)>
290
291	=item B<write ($callback)>
292
293	=item B<write ($data, $callback)>
294
295	This method will write C<$data> to the filehandle and call the C<$callback>
296	afterwards. If only C<$callback> is provided it will be called when the
297	write buffer becomes empty the next time (or immediately if it already is empty).
298
299	=cut
300
301	sub write {
302	my ($self, $data, $cb) = @_;
303	if (ref $data) { $cb = $data; undef $data }
304	push @{$self->{write_bufs}}, [$data, $cb];
305	$self->_check_writer;
306	}
307
308	sub _check_writer {
309	my ($self) = @_;
310
311	if ($self->{write_w}) {
312	unless ($self->{write_cb}) {
313	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
314	my $wba = shift @{$self->{write_bufs}};
315	$self->{wbuf} .= $wba->[0];	2109	$self->{_eof} = 1;
316	}	2110	}
317	}	2111	}
318	return;
319	}
320		2112
321	my $wba = shift @{$self->{write_bufs}}	2113	$self->{_tls_rbuf} .= $tmp;
322	or return;	2114	$self->_drain_rbuf;
323		2115	$self->{tls} or return; # tls session might have gone away in callback
324	unless (defined $wba->[0]) {
325	$wba->[1]->($self) if $wba->[1];
326	$self->_check_writer;
327	return;
328	}	2116	}
329		2117
330	$self->{wbuf} = $wba->[0];	2118	$tmp = Net::SSLeay::get_error ($self->{tls}, -1); # -1 is not neccessarily correct, but Net::SSLeay doesn't tell us
331	$self->{write_cb} = $wba->[1];	2119	return $self->_tls_error ($tmp)
		2120	if $tmp != $ERROR_WANT_READ
		2121	&& ($tmp != $ERROR_SYSCALL || $!);
332		2122
333	$self->{write_w} =	2123	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	2124	$self->{wbuf} .= $tmp;
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	2125	$self->_drain_wbuf;
		2126	$self->{tls} or return; # tls session might have gone away in callback
		2127	}
336		2128
337	if (not defined $l) {	2129	$self->{_on_starttls}
338	return if $! == EAGAIN || $! == EINTR;	2130	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
339	delete $self->{write_w};	2131	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
340	$self->{on_error}->($self) if $self->{on_error};	2132	}
341		2133
		2134	=item $handle->starttls ($tls[, $tls_ctx])
		2135
		2136	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		2137	object is created, you can also do that at a later time by calling
		2138	C<starttls>. See the C<tls> constructor argument for general info.
		2139
		2140	Starting TLS is currently an asynchronous operation - when you push some
		2141	write data and then call C<< ->starttls >> then TLS negotiation will start
		2142	immediately, after which the queued write data is then sent. This might
		2143	change in future versions, so best make sure you have no outstanding write
		2144	data when calling this method.
		2145
		2146	The first argument is the same as the C<tls> constructor argument (either
		2147	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		2148
		2149	The second argument is the optional C<AnyEvent::TLS> object that is used
		2150	when AnyEvent::Handle has to create its own TLS connection object, or
		2151	a hash reference with C<< key => value >> pairs that will be used to
		2152	construct a new context.
		2153
		2154	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		2155	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		2156	changed to your liking. Note that the handshake might have already started
		2157	when this function returns.
		2158
		2159	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		2160	handshakes on the same stream. It is best to not attempt to use the
		2161	stream after stopping TLS.
		2162
		2163	This method may invoke callbacks (and therefore the handle might be
		2164	destroyed after it returns).
		2165
		2166	=cut
		2167
		2168	our %TLS_CACHE; #TODO not yet documented, should we?
		2169
		2170	sub starttls {
		2171	my ($self, $tls, $ctx) = @_;
		2172
		2173	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		2174	if $self->{tls};
		2175
		2176	unless (defined $AnyEvent::TLS::VERSION) {
		2177	eval {
		2178	require Net::SSLeay;
		2179	require AnyEvent::TLS;
		2180	1
		2181	} or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
		2182	}
		2183
		2184	$self->{tls} = $tls;
		2185	$self->{tls_ctx} = $ctx if @_ > 2;
		2186
		2187	return unless $self->{fh};
		2188
		2189	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		2190	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		2191
		2192	$tls = delete $self->{tls};
		2193	$ctx = $self->{tls_ctx};
		2194
		2195	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		2196
		2197	if ("HASH" eq ref $ctx) {
		2198	if ($ctx->{cache}) {
		2199	my $key = $ctx+0;
		2200	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
342	} else {	2201	} else {
		2202	$ctx = new AnyEvent::TLS %$ctx;
		2203	}
		2204	}
		2205
		2206	$self->{tls_ctx} = $ctx || TLS_CTX ();
		2207	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		2208
		2209	# basically, this is deep magic (because SSL_read should have the same issues)
		2210	# but the openssl maintainers basically said: "trust us, it just works".
		2211	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		2212	# and mismaintained ssleay-module doesn't even offer them).
		2213	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		2214	#
		2215	# in short: this is a mess.
		2216	#
		2217	# note that we do not try to keep the length constant between writes as we are required to do.
		2218	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		2219	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2220	# have identity issues in that area.
		2221	# Net::SSLeay::CTX_set_mode ($ssl,
		2222	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		2223	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2224	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		2225
		2226	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		2227	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		2228
		2229	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2230	$self->{rbuf} = "";
		2231
		2232	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		2233
		2234	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		2235	if $self->{on_starttls};
		2236
		2237	&_dotls; # need to trigger the initial handshake
		2238	$self->start_read; # make sure we actually do read
		2239	}
		2240
		2241	=item $handle->stoptls
		2242
		2243	Shuts down the SSL connection - this makes a proper EOF handshake by
		2244	sending a close notify to the other side, but since OpenSSL doesn't
		2245	support non-blocking shut downs, it is not guaranteed that you can re-use
		2246	the stream afterwards.
		2247
		2248	This method may invoke callbacks (and therefore the handle might be
		2249	destroyed after it returns).
		2250
		2251	=cut
		2252
		2253	sub stoptls {
		2254	my ($self) = @_;
		2255
		2256	if ($self->{tls} && $self->{fh}) {
		2257	Net::SSLeay::shutdown ($self->{tls});
		2258
		2259	&_dotls;
		2260
		2261	# # we don't give a shit. no, we do, but we can't. no...#d#
		2262	# # we, we... have to use openssl :/#d#
		2263	# &_freetls;#d#
		2264	}
		2265	}
		2266
		2267	sub _freetls {
		2268	my ($self) = @_;
		2269
		2270	return unless $self->{tls};
		2271
		2272	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2273	if $self->{tls} > 0;
		2274
		2275	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2276	}
		2277
		2278	=item $handle->resettls
		2279
		2280	This rarely-used method simply resets and TLS state on the handle, usually
		2281	causing data loss.
		2282
		2283	One case where it may be useful is when you want to skip over the data in
		2284	the stream but you are not interested in interpreting it, so data loss is
		2285	no concern.
		2286
		2287	=cut
		2288
		2289	*resettls = \&_freetls;
		2290
		2291	sub DESTROY {
		2292	my ($self) = @_;
		2293
		2294	&_freetls;
		2295
		2296	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2297
		2298	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2299	my $fh = delete $self->{fh};
		2300	my $wbuf = delete $self->{wbuf};
		2301
		2302	my @linger;
		2303
		2304	push @linger, AE::io $fh, 1, sub {
		2305	my $len = syswrite $fh, $wbuf, length $wbuf;
		2306
		2307	if ($len > 0) {
343	substr $self->{wbuf}, 0, $l, '';	2308	substr $wbuf, 0, $len, "";
344		2309	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
345	if (length ($self->{wbuf}) == 0) {	2310	@linger = (); # end
346	$self->{write_cb}->($self) if $self->{write_cb};
347
348	delete $self->{write_w};
349	delete $self->{wbuf};
350	delete $self->{write_cb};
351
352	$self->_check_writer;
353	}
354	}	2311	}
		2312	};
		2313	push @linger, AE::timer $linger, 0, sub {
		2314	@linger = ();
		2315	};
		2316	}
		2317	}
		2318
		2319	=item $handle->destroy
		2320
		2321	Shuts down the handle object as much as possible - this call ensures that
		2322	no further callbacks will be invoked and as many resources as possible
		2323	will be freed. Any method you will call on the handle object after
		2324	destroying it in this way will be silently ignored (and it will return the
		2325	empty list).
		2326
		2327	Normally, you can just "forget" any references to an AnyEvent::Handle
		2328	object and it will simply shut down. This works in fatal error and EOF
		2329	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2330	callback, so when you want to destroy the AnyEvent::Handle object from
		2331	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2332	that case.
		2333
		2334	Destroying the handle object in this way has the advantage that callbacks
		2335	will be removed as well, so if those are the only reference holders (as
		2336	is common), then one doesn't need to do anything special to break any
		2337	reference cycles.
		2338
		2339	The handle might still linger in the background and write out remaining
		2340	data, as specified by the C<linger> option, however.
		2341
		2342	=cut
		2343
		2344	sub destroy {
		2345	my ($self) = @_;
		2346
		2347	$self->DESTROY;
		2348	%$self = ();
		2349	bless $self, "AnyEvent::Handle::destroyed";
		2350	}
		2351
		2352	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2353	#nop
		2354	}
		2355
		2356	=item $handle->destroyed
		2357
		2358	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2359	->destroy >>, true otherwise.
		2360
		2361	Can be useful to decide whether the handle is still valid after some
		2362	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2363	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2364	can destroy the handle, so work can be avoided by checking sometimes:
		2365
		2366	$hdl->starttls ("accept");
		2367	return if $hdl->destroyed;
		2368	$hdl->push_write (...
		2369
		2370	Note that the call to C<push_write> will silently be ignored if the handle
		2371	has been destroyed, so often you can just ignore the possibility of the
		2372	handle being destroyed.
		2373
		2374	=cut
		2375
		2376	sub destroyed { 0 }
		2377	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2378
		2379	=item AnyEvent::Handle::TLS_CTX
		2380
		2381	This function creates and returns the AnyEvent::TLS object used by default
		2382	for TLS mode.
		2383
		2384	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2385
		2386	=cut
		2387
		2388	our $TLS_CTX;
		2389
		2390	sub TLS_CTX() {
		2391	$TLS_CTX ||= do {
		2392	require AnyEvent::TLS;
		2393
		2394	new AnyEvent::TLS
		2395	}
		2396	}
		2397
		2398	=back
		2399
		2400
		2401	=head1 NONFREQUENTLY ASKED QUESTIONS
		2402
		2403	=over 4
		2404
		2405	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2406	still get further invocations!
		2407
		2408	That's because AnyEvent::Handle keeps a reference to itself when handling
		2409	read or write callbacks.
		2410
		2411	It is only safe to "forget" the reference inside EOF or error callbacks,
		2412	from within all other callbacks, you need to explicitly call the C<<
		2413	->destroy >> method.
		2414
		2415	=item Why is my C<on_eof> callback never called?
		2416
		2417	Probably because your C<on_error> callback is being called instead: When
		2418	you have outstanding requests in your read queue, then an EOF is
		2419	considered an error as you clearly expected some data.
		2420
		2421	To avoid this, make sure you have an empty read queue whenever your handle
		2422	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2423	an C<on_read> handler that simply pushes the first read requests in the
		2424	queue.
		2425
		2426	See also the next question, which explains this in a bit more detail.
		2427
		2428	=item How can I serve requests in a loop?
		2429
		2430	Most protocols consist of some setup phase (authentication for example)
		2431	followed by a request handling phase, where the server waits for requests
		2432	and handles them, in a loop.
		2433
		2434	There are two important variants: The first (traditional, better) variant
		2435	handles requests until the server gets some QUIT command, causing it to
		2436	close the connection first (highly desirable for a busy TCP server). A
		2437	client dropping the connection is an error, which means this variant can
		2438	detect an unexpected detection close.
		2439
		2440	To handle this case, always make sure you have a non-empty read queue, by
		2441	pushing the "read request start" handler on it:
		2442
		2443	# we assume a request starts with a single line
		2444	my @start_request; @start_request = (line => sub {
		2445	my ($hdl, $line) = @_;
		2446
		2447	... handle request
		2448
		2449	# push next request read, possibly from a nested callback
		2450	$hdl->push_read (@start_request);
		2451	});
		2452
		2453	# auth done, now go into request handling loop
		2454	# now push the first @start_request
		2455	$hdl->push_read (@start_request);
		2456
		2457	By always having an outstanding C<push_read>, the handle always expects
		2458	some data and raises the C<EPIPE> error when the connction is dropped
		2459	unexpectedly.
		2460
		2461	The second variant is a protocol where the client can drop the connection
		2462	at any time. For TCP, this means that the server machine may run out of
		2463	sockets easier, and in general, it means you cannot distinguish a protocl
		2464	failure/client crash from a normal connection close. Nevertheless, these
		2465	kinds of protocols are common (and sometimes even the best solution to the
		2466	problem).
		2467
		2468	Having an outstanding read request at all times is possible if you ignore
		2469	C<EPIPE> errors, but this doesn't help with when the client drops the
		2470	connection during a request, which would still be an error.
		2471
		2472	A better solution is to push the initial request read in an C<on_read>
		2473	callback. This avoids an error, as when the server doesn't expect data
		2474	(i.e. is idly waiting for the next request, an EOF will not raise an
		2475	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2476	and simpler:
		2477
		2478	# auth done, now go into request handling loop
		2479	$hdl->on_read (sub {
		2480	my ($hdl) = @_;
		2481
		2482	# called each time we receive data but the read queue is empty
		2483	# simply start read the request
		2484
		2485	$hdl->push_read (line => sub {
		2486	my ($hdl, $line) = @_;
		2487
		2488	... handle request
		2489
		2490	# do nothing special when the request has been handled, just
		2491	# let the request queue go empty.
355	});	2492	});
356	}	2493	});
		2494
		2495	=item I get different callback invocations in TLS mode/Why can't I pause
		2496	reading?
		2497
		2498	Unlike, say, TCP, TLS connections do not consist of two independent
		2499	communication channels, one for each direction. Or put differently, the
		2500	read and write directions are not independent of each other: you cannot
		2501	write data unless you are also prepared to read, and vice versa.
		2502
		2503	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2504	callback invocations when you are not expecting any read data - the reason
		2505	is that AnyEvent::Handle always reads in TLS mode.
		2506
		2507	During the connection, you have to make sure that you always have a
		2508	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2509	connection (or when you no longer want to use it) you can call the
		2510	C<destroy> method.
		2511
		2512	=item How do I read data until the other side closes the connection?
		2513
		2514	If you just want to read your data into a perl scalar, the easiest way
		2515	to achieve this is by setting an C<on_read> callback that does nothing,
		2516	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2517	will be in C<$_[0]{rbuf}>:
		2518
		2519	$handle->on_read (sub { });
		2520	$handle->on_eof (undef);
		2521	$handle->on_error (sub {
		2522	my $data = delete $_[0]{rbuf};
		2523	});
		2524
		2525	Note that this example removes the C<rbuf> member from the handle object,
		2526	which is not normally allowed by the API. It is expressly permitted in
		2527	this case only, as the handle object needs to be destroyed afterwards.
		2528
		2529	The reason to use C<on_error> is that TCP connections, due to latencies
		2530	and packets loss, might get closed quite violently with an error, when in
		2531	fact all data has been received.
		2532
		2533	It is usually better to use acknowledgements when transferring data,
		2534	to make sure the other side hasn't just died and you got the data
		2535	intact. This is also one reason why so many internet protocols have an
		2536	explicit QUIT command.
		2537
		2538	=item I don't want to destroy the handle too early - how do I wait until
		2539	all data has been written?
		2540
		2541	After writing your last bits of data, set the C<on_drain> callback
		2542	and destroy the handle in there - with the default setting of
		2543	C<low_water_mark> this will be called precisely when all data has been
		2544	written to the socket:
		2545
		2546	$handle->push_write (...);
		2547	$handle->on_drain (sub {
		2548	AE::log debug => "All data submitted to the kernel.";
		2549	undef $handle;
		2550	});
		2551
		2552	If you just want to queue some data and then signal EOF to the other side,
		2553	consider using C<< ->push_shutdown >> instead.
		2554
		2555	=item I want to contact a TLS/SSL server, I don't care about security.
		2556
		2557	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2558	connect to it and then create the AnyEvent::Handle with the C<tls>
		2559	parameter:
		2560
		2561	tcp_connect $host, $port, sub {
		2562	my ($fh) = @_;
		2563
		2564	my $handle = new AnyEvent::Handle
		2565	fh => $fh,
		2566	tls => "connect",
		2567	on_error => sub { ... };
		2568
		2569	$handle->push_write (...);
		2570	};
		2571
		2572	=item I want to contact a TLS/SSL server, I do care about security.
		2573
		2574	Then you should additionally enable certificate verification, including
		2575	peername verification, if the protocol you use supports it (see
		2576	L<AnyEvent::TLS>, C<verify_peername>).
		2577
		2578	E.g. for HTTPS:
		2579
		2580	tcp_connect $host, $port, sub {
		2581	my ($fh) = @_;
		2582
		2583	my $handle = new AnyEvent::Handle
		2584	fh => $fh,
		2585	peername => $host,
		2586	tls => "connect",
		2587	tls_ctx => { verify => 1, verify_peername => "https" },
		2588	...
		2589
		2590	Note that you must specify the hostname you connected to (or whatever
		2591	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2592	peername verification will be done.
		2593
		2594	The above will use the system-dependent default set of trusted CA
		2595	certificates. If you want to check against a specific CA, add the
		2596	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2597
		2598	tls_ctx => {
		2599	verify => 1,
		2600	verify_peername => "https",
		2601	ca_file => "my-ca-cert.pem",
		2602	},
		2603
		2604	=item I want to create a TLS/SSL server, how do I do that?
		2605
		2606	Well, you first need to get a server certificate and key. You have
		2607	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2608	self-signed certificate (cheap. check the search engine of your choice,
		2609	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2610	nice program for that purpose).
		2611
		2612	Then create a file with your private key (in PEM format, see
		2613	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2614	file should then look like this:
		2615
		2616	-----BEGIN RSA PRIVATE KEY-----
		2617	...header data
		2618	... lots of base64'y-stuff
		2619	-----END RSA PRIVATE KEY-----
		2620
		2621	-----BEGIN CERTIFICATE-----
		2622	... lots of base64'y-stuff
		2623	-----END CERTIFICATE-----
		2624
		2625	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2626	specify this file as C<cert_file>:
		2627
		2628	tcp_server undef, $port, sub {
		2629	my ($fh) = @_;
		2630
		2631	my $handle = new AnyEvent::Handle
		2632	fh => $fh,
		2633	tls => "accept",
		2634	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2635	...
		2636
		2637	When you have intermediate CA certificates that your clients might not
		2638	know about, just append them to the C<cert_file>.
357		2639
358	=back	2640	=back
359		2641
		2642	=head1 SUBCLASSING AnyEvent::Handle
		2643
		2644	In many cases, you might want to subclass AnyEvent::Handle.
		2645
		2646	To make this easier, a given version of AnyEvent::Handle uses these
		2647	conventions:
		2648
		2649	=over 4
		2650
		2651	=item * all constructor arguments become object members.
		2652
		2653	At least initially, when you pass a C<tls>-argument to the constructor it
		2654	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2655	mutated later on (for example C<tls> will hold the TLS connection object).
		2656
		2657	=item * other object member names are prefixed with an C<_>.
		2658
		2659	All object members not explicitly documented (internal use) are prefixed
		2660	with an underscore character, so the remaining non-C<_>-namespace is free
		2661	for use for subclasses.
		2662
		2663	=item * all members not documented here and not prefixed with an underscore
		2664	are free to use in subclasses.
		2665
		2666	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2667	member variables, but that's just life. At least it is documented.
		2668
		2669	=back
		2670
360	=head1 AUTHOR	2671	=head1 AUTHOR
361		2672
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	2673	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363		2674
364	=cut	2675	=cut
365		2676
366	1; # End of AnyEvent::Handle	2677	1
		2678

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines