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Revision 1.6 by elmex, Mon Apr 28 09:27:47 2008 UTC vs.
Revision 1.182 by root, Thu Sep 3 12:35:01 2009 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict;
5
6	use AnyEvent;
7	use IO::Handle;
8	use Errno qw/EAGAIN EINTR/;
9
10	=head1 NAME	1	=head1 NAME
11		2
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut
19
20	our $VERSION = '0.01';
21		4
22	=head1 SYNOPSIS	5	=head1 SYNOPSIS
23		6
24	use AnyEvent;	7	use AnyEvent;
25	use AnyEvent::Handle;	8	use AnyEvent::Handle;
26		9
27	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
28		11
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
		13	fh => \*STDIN,
		14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	warn "got error $msg\n";
		17	$hdl->destroy;
		18	$cv->send;
		19	);
30		20
31	$ae_fh->on_eof (sub { $cv->broadcast });	21	# send some request line
		22	$hdl->push_write ("getinfo\015\012");
32		23
33	$ae_fh->readlines (sub {	24	# read the response line
		25	$hdl->push_read (line => sub {
34	my ($ae_fh, @lines) = @_;	26	my ($hdl, $line) = @_;
35	for (@lines) {	27	warn "got line <$line>\n";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
		32
		33	=head1 DESCRIPTION
		34
		35	This module is a helper module to make it easier to do event-based I/O on
		36	filehandles.
		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
		41	In the following, when the documentation refers to of "bytes" then this
		42	means characters. As sysread and syswrite are used for all I/O, their
		43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
		48	All callbacks will be invoked with the handle object as their first
		49	argument.
		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	=head1 METHODS
		66
		67	=over 4
		68
		69	=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
		70
		71	The constructor supports these arguments (all as C<< key => value >> pairs).
		72
		73	=over 4
		74
		75	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		76
		77	The filehandle this L<AnyEvent::Handle> object will operate on.
		78	NOTE: The filehandle will be set to non-blocking mode (using
		79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
		81
		82	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		83
		84	Try to connect to the specified host and service (port), using
		85	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		86	default C<peername>.
		87
		88	You have to specify either this parameter, or C<fh>, above.
		89
		90	It is possible to push requests on the read and write queues, and modify
		91	properties of the stream, even while AnyEvent::Handle is connecting.
		92
		93	When this parameter is specified, then the C<on_prepare>,
		94	C<on_connect_error> and C<on_connect> callbacks will be called under the
		95	appropriate circumstances:
		96
		97	=over 4
		98
		99	=item on_prepare => $cb->($handle)
		100
		101	This (rarely used) callback is called before a new connection is
		102	attempted, but after the file handle has been created. It could be used to
		103	prepare the file handle with parameters required for the actual connect
		104	(as opposed to settings that can be changed when the connection is already
		105	established).
		106
		107	The return value of this callback should be the connect timeout value in
		108	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		109	timeout is to be used).
		110
		111	=item on_connect => $cb->($handle, $host, $port, $retry->())
		112
		113	This callback is called when a connection has been successfully established.
		114
		115	The actual numeric host and port (the socket peername) are passed as
		116	parameters, together with a retry callback.
		117
		118	When, for some reason, the handle is not acceptable, then calling
		119	C<$retry> will continue with the next conenction target (in case of
		120	multi-homed hosts or SRV records there can be multiple connection
		121	endpoints). When it is called then the read and write queues, eof status,
		122	tls status and similar properties of the handle are being reset.
		123
		124	In most cases, ignoring the C<$retry> parameter is the way to go.
		125
		126	=item on_connect_error => $cb->($handle, $message)
		127
		128	This callback is called when the conenction could not be
		129	established. C<$!> will contain the relevant error code, and C<$message> a
		130	message describing it (usually the same as C<"$!">).
		131
		132	If this callback isn't specified, then C<on_error> will be called with a
		133	fatal error instead.
		134
		135	=back
		136
		137	=item on_error => $cb->($handle, $fatal, $message)
		138
		139	This is the error callback, which is called when, well, some error
		140	occured, such as not being able to resolve the hostname, failure to
		141	connect or a read error.
		142
		143	Some errors are fatal (which is indicated by C<$fatal> being true). On
		144	fatal errors the handle object will be destroyed (by a call to C<< ->
		145	destroy >>) after invoking the error callback (which means you are free to
		146	examine the handle object). Examples of fatal errors are an EOF condition
		147	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		148	cases where the other side can close the connection at their will it is
		149	often easiest to not report C<EPIPE> errors in this callback.
		150
		151	AnyEvent::Handle tries to find an appropriate error code for you to check
		152	against, but in some cases (TLS errors), this does not work well. It is
		153	recommended to always output the C<$message> argument in human-readable
		154	error messages (it's usually the same as C<"$!">).
		155
		156	Non-fatal errors can be retried by simply returning, but it is recommended
		157	to simply ignore this parameter and instead abondon the handle object
		158	when this callback is invoked. Examples of non-fatal errors are timeouts
		159	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		160
		161	On callback entrance, the value of C<$!> contains the operating system
		162	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		163	C<EPROTO>).
		164
		165	While not mandatory, it is I<highly> recommended to set this callback, as
		166	you will not be notified of errors otherwise. The default simply calls
		167	C<croak>.
		168
		169	=item on_read => $cb->($handle)
		170
		171	This sets the default read callback, which is called when data arrives
		172	and no read request is in the queue (unlike read queue callbacks, this
		173	callback will only be called when at least one octet of data is in the
		174	read buffer).
		175
		176	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		177	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		178	must not enlarge or modify the read buffer, you can only remove data at
		179	the beginning from it.
		180
		181	When an EOF condition is detected then AnyEvent::Handle will first try to
		182	feed all the remaining data to the queued callbacks and C<on_read> before
		183	calling the C<on_eof> callback. If no progress can be made, then a fatal
		184	error will be raised (with C<$!> set to C<EPIPE>).
		185
		186	Note that, unlike requests in the read queue, an C<on_read> callback
		187	doesn't mean you I<require> some data: if there is an EOF and there
		188	are outstanding read requests then an error will be flagged. With an
		189	C<on_read> callback, the C<on_eof> callback will be invoked.
		190
		191	=item on_eof => $cb->($handle)
		192
		193	Set the callback to be called when an end-of-file condition is detected,
		194	i.e. in the case of a socket, when the other side has closed the
		195	connection cleanly, and there are no outstanding read requests in the
		196	queue (if there are read requests, then an EOF counts as an unexpected
		197	connection close and will be flagged as an error).
		198
		199	For sockets, this just means that the other side has stopped sending data,
		200	you can still try to write data, and, in fact, one can return from the EOF
		201	callback and continue writing data, as only the read part has been shut
		202	down.
		203
		204	If an EOF condition has been detected but no C<on_eof> callback has been
		205	set, then a fatal error will be raised with C<$!> set to <0>.
		206
		207	=item on_drain => $cb->($handle)
		208
		209	This sets the callback that is called when the write buffer becomes empty
		210	(or when the callback is set and the buffer is empty already).
		211
		212	To append to the write buffer, use the C<< ->push_write >> method.
		213
		214	This callback is useful when you don't want to put all of your write data
		215	into the queue at once, for example, when you want to write the contents
		216	of some file to the socket you might not want to read the whole file into
		217	memory and push it into the queue, but instead only read more data from
		218	the file when the write queue becomes empty.
		219
		220	=item timeout => $fractional_seconds
		221
		222	=item rtimeout => $fractional_seconds
		223
		224	=item wtimeout => $fractional_seconds
		225
		226	If non-zero, then these enables an "inactivity" timeout: whenever this
		227	many seconds pass without a successful read or write on the underlying
		228	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		229	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		230	error will be raised).
		231
		232	There are three variants of the timeouts that work fully independent
		233	of each other, for both read and write, just read, and just write:
		234	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		235	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		236	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		237
		238	Note that timeout processing is also active when you currently do not have
		239	any outstanding read or write requests: If you plan to keep the connection
		240	idle then you should disable the timout temporarily or ignore the timeout
		241	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		242	restart the timeout.
		243
		244	Zero (the default) disables this timeout.
		245
		246	=item on_timeout => $cb->($handle)
		247
		248	Called whenever the inactivity timeout passes. If you return from this
		249	callback, then the timeout will be reset as if some activity had happened,
		250	so this condition is not fatal in any way.
		251
		252	=item rbuf_max => <bytes>
		253
		254	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		255	when the read buffer ever (strictly) exceeds this size. This is useful to
		256	avoid some forms of denial-of-service attacks.
		257
		258	For example, a server accepting connections from untrusted sources should
		259	be configured to accept only so-and-so much data that it cannot act on
		260	(for example, when expecting a line, an attacker could send an unlimited
		261	amount of data without a callback ever being called as long as the line
		262	isn't finished).
		263
		264	=item autocork => <boolean>
		265
		266	When disabled (the default), then C<push_write> will try to immediately
		267	write the data to the handle, if possible. This avoids having to register
		268	a write watcher and wait for the next event loop iteration, but can
		269	be inefficient if you write multiple small chunks (on the wire, this
		270	disadvantage is usually avoided by your kernel's nagle algorithm, see
		271	C<no_delay>, but this option can save costly syscalls).
		272
		273	When enabled, then writes will always be queued till the next event loop
		274	iteration. This is efficient when you do many small writes per iteration,
		275	but less efficient when you do a single write only per iteration (or when
		276	the write buffer often is full). It also increases write latency.
		277
		278	=item no_delay => <boolean>
		279
		280	When doing small writes on sockets, your operating system kernel might
		281	wait a bit for more data before actually sending it out. This is called
		282	the Nagle algorithm, and usually it is beneficial.
		283
		284	In some situations you want as low a delay as possible, which can be
		285	accomplishd by setting this option to a true value.
		286
		287	The default is your opertaing system's default behaviour (most likely
		288	enabled), this option explicitly enables or disables it, if possible.
		289
		290	=item keepalive => <boolean>
		291
		292	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		293	normally, TCP connections have no time-out once established, so TCP
		294	conenctions, once established, can stay alive forever even when the other
		295	side has long gone. TCP keepalives are a cheap way to take down long-lived
		296	TCP connections whent he other side becomes unreachable. While the default
		297	is OS-dependent, TCP keepalives usually kick in after around two hours,
		298	and, if the other side doesn't reply, take down the TCP connection some 10
		299	to 15 minutes later.
		300
		301	It is harmless to specify this option for file handles that do not support
		302	keepalives, and enabling it on connections that are potentially long-lived
		303	is usually a good idea.
		304
		305	=item oobinline => <boolean>
		306
		307	BSD majorly fucked up the implementation of TCP urgent data. The result
		308	is that almost no OS implements TCP according to the specs, and every OS
		309	implements it slightly differently.
		310
		311	If you want to handle TCP urgent data, then setting this flag gives you
		312	the most portable way of getting urgent data, by putting it into the
		313	stream.
		314
		315	=item read_size => <bytes>
		316
		317	The default read block size (the amount of bytes this module will
		318	try to read during each loop iteration, which affects memory
		319	requirements). Default: C<8192>.
		320
		321	=item low_water_mark => <bytes>
		322
		323	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		324	buffer: If the write reaches this size or gets even samller it is
		325	considered empty.
		326
		327	Sometimes it can be beneficial (for performance reasons) to add data to
		328	the write buffer before it is fully drained, but this is a rare case, as
		329	the operating system kernel usually buffers data as well, so the default
		330	is good in almost all cases.
		331
		332	=item linger => <seconds>
		333
		334	If non-zero (default: C<3600>), then the destructor of the
		335	AnyEvent::Handle object will check whether there is still outstanding
		336	write data and will install a watcher that will write this data to the
		337	socket. No errors will be reported (this mostly matches how the operating
		338	system treats outstanding data at socket close time).
		339
		340	This will not work for partial TLS data that could not be encoded
		341	yet. This data will be lost. Calling the C<stoptls> method in time might
		342	help.
		343
		344	=item peername => $string
		345
		346	A string used to identify the remote site - usually the DNS hostname
		347	(I<not> IDN!) used to create the connection, rarely the IP address.
		348
		349	Apart from being useful in error messages, this string is also used in TLS
		350	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		351	verification will be skipped when C<peername> is not specified or
		352	C<undef>.
		353
		354	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		355
		356	When this parameter is given, it enables TLS (SSL) mode, that means
		357	AnyEvent will start a TLS handshake as soon as the conenction has been
		358	established and will transparently encrypt/decrypt data afterwards.
		359
		360	All TLS protocol errors will be signalled as C<EPROTO>, with an
		361	appropriate error message.
		362
		363	TLS mode requires Net::SSLeay to be installed (it will be loaded
		364	automatically when you try to create a TLS handle): this module doesn't
		365	have a dependency on that module, so if your module requires it, you have
		366	to add the dependency yourself.
		367
		368	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		369	C<accept>, and for the TLS client side of a connection, use C<connect>
		370	mode.
		371
		372	You can also provide your own TLS connection object, but you have
		373	to make sure that you call either C<Net::SSLeay::set_connect_state>
		374	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		375	AnyEvent::Handle. Also, this module will take ownership of this connection
		376	object.
		377
		378	At some future point, AnyEvent::Handle might switch to another TLS
		379	implementation, then the option to use your own session object will go
		380	away.
		381
		382	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		383	passing in the wrong integer will lead to certain crash. This most often
		384	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		385	segmentation fault.
		386
		387	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		388
		389	=item tls_ctx => $anyevent_tls
		390
		391	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		392	(unless a connection object was specified directly). If this parameter is
		393	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		394
		395	Instead of an object, you can also specify a hash reference with C<< key
		396	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		397	new TLS context object.
		398
		399	=item on_starttls => $cb->($handle, $success[, $error_message])
		400
		401	This callback will be invoked when the TLS/SSL handshake has finished. If
		402	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		403	(C<on_stoptls> will not be called in this case).
		404
		405	The session in C<< $handle->{tls} >> can still be examined in this
		406	callback, even when the handshake was not successful.
		407
		408	TLS handshake failures will not cause C<on_error> to be invoked when this
		409	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		410
		411	Without this callback, handshake failures lead to C<on_error> being
		412	called, as normal.
		413
		414	Note that you cannot call C<starttls> right again in this callback. If you
		415	need to do that, start an zero-second timer instead whose callback can
		416	then call C<< ->starttls >> again.
		417
		418	=item on_stoptls => $cb->($handle)
		419
		420	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		421	set, then it will be invoked after freeing the TLS session. If it is not,
		422	then a TLS shutdown condition will be treated like a normal EOF condition
		423	on the handle.
		424
		425	The session in C<< $handle->{tls} >> can still be examined in this
		426	callback.
		427
		428	This callback will only be called on TLS shutdowns, not when the
		429	underlying handle signals EOF.
		430
		431	=item json => JSON or JSON::XS object
		432
		433	This is the json coder object used by the C<json> read and write types.
		434
		435	If you don't supply it, then AnyEvent::Handle will create and use a
		436	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		437	texts.
		438
		439	Note that you are responsible to depend on the JSON module if you want to
		440	use this functionality, as AnyEvent does not have a dependency itself.
		441
		442	=back
		443
		444	=cut
		445
		446	sub new {
		447	my $class = shift;
		448	my $self = bless { @_ }, $class;
		449
		450	if ($self->{fh}) {
		451	$self->_start;
		452	return unless $self->{fh}; # could be gone by now
		453
		454	} elsif ($self->{connect}) {
		455	require AnyEvent::Socket;
		456
		457	$self->{peername} = $self->{connect}[0]
		458	unless exists $self->{peername};
		459
		460	$self->{_skip_drain_rbuf} = 1;
		461
		462	{
		463	Scalar::Util::weaken (my $self = $self);
		464
		465	$self->{_connect} =
		466	AnyEvent::Socket::tcp_connect (
		467	$self->{connect}[0],
		468	$self->{connect}[1],
		469	sub {
		470	my ($fh, $host, $port, $retry) = @_;
		471
		472	if ($fh) {
		473	$self->{fh} = $fh;
		474
		475	delete $self->{_skip_drain_rbuf};
		476	$self->_start;
		477
		478	$self->{on_connect}
		479	and $self->{on_connect}($self, $host, $port, sub {
		480	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		481	$self->{_skip_drain_rbuf} = 1;
		482	&$retry;
		483	});
		484
		485	} else {
		486	if ($self->{on_connect_error}) {
		487	$self->{on_connect_error}($self, "$!");
		488	$self->destroy;
		489	} else {
		490	$self->_error ($!, 1);
		491	}
		492	}
		493	},
		494	sub {
		495	local $self->{fh} = $_[0];
		496
		497	$self->{on_prepare}
		498	? $self->{on_prepare}->($self)
		499	: ()
		500	}
		501	);
		502	}
		503
		504	} else {
		505	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		506	}
		507
		508	$self
		509	}
		510
		511	sub _start {
		512	my ($self) = @_;
		513
		514	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		515
		516	$self->{_activity} =
		517	$self->{_ractivity} =
		518	$self->{_wactivity} = AE::now;
		519
		520	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		521	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		522	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		523
		524	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay};
		525	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive};
		526	$self->oobinline (delete $self->{oobinline}) if exists $self->{oobinline};
		527
		528	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		529	if $self->{tls};
		530
		531	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		532
		533	$self->start_read
		534	if $self->{on_read} || @{ $self->{_queue} };
		535
		536	$self->_drain_wbuf;
		537	}
		538
		539	sub _error {
		540	my ($self, $errno, $fatal, $message) = @_;
		541
		542	$! = $errno;
		543	$message ||= "$!";
		544
		545	if ($self->{on_error}) {
		546	$self->{on_error}($self, $fatal, $message);
		547	$self->destroy if $fatal;
		548	} elsif ($self->{fh}) {
		549	$self->destroy;
		550	Carp::croak "AnyEvent::Handle uncaught error: $message";
		551	}
		552	}
		553
		554	=item $fh = $handle->fh
		555
		556	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		557
		558	=cut
		559
		560	sub fh { $_[0]{fh} }
		561
		562	=item $handle->on_error ($cb)
		563
		564	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		565
		566	=cut
		567
		568	sub on_error {
		569	$_[0]{on_error} = $_[1];
		570	}
		571
		572	=item $handle->on_eof ($cb)
		573
		574	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		575
		576	=cut
		577
		578	sub on_eof {
		579	$_[0]{on_eof} = $_[1];
		580	}
		581
		582	=item $handle->on_timeout ($cb)
		583
		584	=item $handle->on_rtimeout ($cb)
		585
		586	=item $handle->on_wtimeout ($cb)
		587
		588	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		589	callback, or disables the callback (but not the timeout) if C<$cb> =
		590	C<undef>. See the C<timeout> constructor argument and method.
		591
		592	=cut
		593
		594	# see below
		595
		596	=item $handle->autocork ($boolean)
		597
		598	Enables or disables the current autocork behaviour (see C<autocork>
		599	constructor argument). Changes will only take effect on the next write.
		600
		601	=cut
		602
		603	sub autocork {
		604	$_[0]{autocork} = $_[1];
		605	}
		606
		607	=item $handle->no_delay ($boolean)
		608
		609	Enables or disables the C<no_delay> setting (see constructor argument of
		610	the same name for details).
		611
		612	=cut
		613
		614	sub no_delay {
		615	$_[0]{no_delay} = $_[1];
		616
		617	eval {
		618	local $SIG{__DIE__};
		619	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		620	if $_[0]{fh};
		621	};
		622	}
		623
		624	=item $handle->keepalive ($boolean)
		625
		626	Enables or disables the C<keepalive> setting (see constructor argument of
		627	the same name for details).
		628
		629	=cut
		630
		631	sub keepalive {
		632	$_[0]{keepalive} = $_[1];
		633
		634	eval {
		635	local $SIG{__DIE__};
		636	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		637	if $_[0]{fh};
		638	};
		639	}
		640
		641	=item $handle->oobinline ($boolean)
		642
		643	Enables or disables the C<oobinline> setting (see constructor argument of
		644	the same name for details).
		645
		646	=cut
		647
		648	sub oobinline {
		649	$_[0]{oobinline} = $_[1];
		650
		651	eval {
		652	local $SIG{__DIE__};
		653	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		654	if $_[0]{fh};
		655	};
		656	}
		657
		658	=item $handle->keepalive ($boolean)
		659
		660	Enables or disables the C<keepalive> setting (see constructor argument of
		661	the same name for details).
		662
		663	=cut
		664
		665	sub keepalive {
		666	$_[0]{keepalive} = $_[1];
		667
		668	eval {
		669	local $SIG{__DIE__};
		670	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		671	if $_[0]{fh};
		672	};
		673	}
		674
		675	=item $handle->on_starttls ($cb)
		676
		677	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		678
		679	=cut
		680
		681	sub on_starttls {
		682	$_[0]{on_starttls} = $_[1];
		683	}
		684
		685	=item $handle->on_stoptls ($cb)
		686
		687	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		688
		689	=cut
		690
		691	sub on_starttls {
		692	$_[0]{on_stoptls} = $_[1];
		693	}
		694
		695	=item $handle->rbuf_max ($max_octets)
		696
		697	Configures the C<rbuf_max> setting (C<undef> disables it).
		698
		699	=cut
		700
		701	sub rbuf_max {
		702	$_[0]{rbuf_max} = $_[1];
		703	}
		704
		705	#############################################################################
		706
		707	=item $handle->timeout ($seconds)
		708
		709	=item $handle->rtimeout ($seconds)
		710
		711	=item $handle->wtimeout ($seconds)
		712
		713	Configures (or disables) the inactivity timeout.
		714
		715	=item $handle->timeout_reset
		716
		717	=item $handle->rtimeout_reset
		718
		719	=item $handle->wtimeout_reset
		720
		721	Reset the activity timeout, as if data was received or sent.
		722
		723	These methods are cheap to call.
		724
		725	=cut
		726
		727	for my $dir ("", "r", "w") {
		728	my $timeout = "${dir}timeout";
		729	my $tw = "_${dir}tw";
		730	my $on_timeout = "on_${dir}timeout";
		731	my $activity = "_${dir}activity";
		732	my $cb;
		733
		734	*$on_timeout = sub {
		735	$_[0]{$on_timeout} = $_[1];
		736	};
		737
		738	*$timeout = sub {
		739	my ($self, $new_value) = @_;
		740
		741	$self->{$timeout} = $new_value;
		742	delete $self->{$tw}; &$cb;
		743	};
		744
		745	*{"${dir}timeout_reset"} = sub {
		746	$_[0]{$activity} = AE::now;
		747	};
		748
		749	# main workhorse:
		750	# reset the timeout watcher, as neccessary
		751	# also check for time-outs
		752	$cb = sub {
		753	my ($self) = @_;
		754
		755	if ($self->{$timeout} && $self->{fh}) {
		756	my $NOW = AE::now;
		757
		758	# when would the timeout trigger?
		759	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		760
		761	# now or in the past already?
		762	if ($after <= 0) {
		763	$self->{$activity} = $NOW;
		764
		765	if ($self->{$on_timeout}) {
		766	$self->{$on_timeout}($self);
		767	} else {
		768	$self->_error (Errno::ETIMEDOUT);
		769	}
		770
		771	# callback could have changed timeout value, optimise
		772	return unless $self->{$timeout};
		773
		774	# calculate new after
		775	$after = $self->{$timeout};
		776	}
		777
		778	Scalar::Util::weaken $self;
		779	return unless $self; # ->error could have destroyed $self
		780
		781	$self->{$tw} ||= AE::timer $after, 0, sub {
		782	delete $self->{$tw};
		783	$cb->($self);
36	chomp;	784	};
37	print "Line: $_";	785	} else {
		786	delete $self->{$tw};
		787	}
		788	}
		789	}
		790
		791	#############################################################################
		792
		793	=back
		794
		795	=head2 WRITE QUEUE
		796
		797	AnyEvent::Handle manages two queues per handle, one for writing and one
		798	for reading.
		799
		800	The write queue is very simple: you can add data to its end, and
		801	AnyEvent::Handle will automatically try to get rid of it for you.
		802
		803	When data could be written and the write buffer is shorter then the low
		804	water mark, the C<on_drain> callback will be invoked.
		805
		806	=over 4
		807
		808	=item $handle->on_drain ($cb)
		809
		810	Sets the C<on_drain> callback or clears it (see the description of
		811	C<on_drain> in the constructor).
		812
		813	=cut
		814
		815	sub on_drain {
		816	my ($self, $cb) = @_;
		817
		818	$self->{on_drain} = $cb;
		819
		820	$cb->($self)
		821	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		822	}
		823
		824	=item $handle->push_write ($data)
		825
		826	Queues the given scalar to be written. You can push as much data as you
		827	want (only limited by the available memory), as C<AnyEvent::Handle>
		828	buffers it independently of the kernel.
		829
		830	=cut
		831
		832	sub _drain_wbuf {
		833	my ($self) = @_;
		834
		835	if (!$self->{_ww} && length $self->{wbuf}) {
		836
		837	Scalar::Util::weaken $self;
		838
		839	my $cb = sub {
		840	my $len = syswrite $self->{fh}, $self->{wbuf};
		841
		842	if (defined $len) {
		843	substr $self->{wbuf}, 0, $len, "";
		844
		845	$self->{_activity} = $self->{_wactivity} = AE::now;
		846
		847	$self->{on_drain}($self)
		848	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		849	&& $self->{on_drain};
		850
		851	delete $self->{_ww} unless length $self->{wbuf};
		852	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		853	$self->_error ($!, 1);
		854	}
		855	};
		856
		857	# try to write data immediately
		858	$cb->() unless $self->{autocork};
		859
		860	# if still data left in wbuf, we need to poll
		861	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		862	if length $self->{wbuf};
		863	};
		864	}
		865
		866	our %WH;
		867
		868	sub register_write_type($$) {
		869	$WH{$_[0]} = $_[1];
		870	}
		871
		872	sub push_write {
		873	my $self = shift;
		874
		875	if (@_ > 1) {
		876	my $type = shift;
		877
		878	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		879	->($self, @_);
		880	}
		881
		882	if ($self->{tls}) {
		883	$self->{_tls_wbuf} .= $_[0];
		884	&_dotls ($self) if $self->{fh};
		885	} else {
		886	$self->{wbuf} .= $_[0];
		887	$self->_drain_wbuf if $self->{fh};
		888	}
		889	}
		890
		891	=item $handle->push_write (type => @args)
		892
		893	Instead of formatting your data yourself, you can also let this module do
		894	the job by specifying a type and type-specific arguments.
		895
		896	Predefined types are (if you have ideas for additional types, feel free to
		897	drop by and tell us):
		898
		899	=over 4
		900
		901	=item netstring => $string
		902
		903	Formats the given value as netstring
		904	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		905
		906	=cut
		907
		908	register_write_type netstring => sub {
		909	my ($self, $string) = @_;
		910
		911	(length $string) . ":$string,"
		912	};
		913
		914	=item packstring => $format, $data
		915
		916	An octet string prefixed with an encoded length. The encoding C<$format>
		917	uses the same format as a Perl C<pack> format, but must specify a single
		918	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		919	optional C<!>, C<< < >> or C<< > >> modifier).
		920
		921	=cut
		922
		923	register_write_type packstring => sub {
		924	my ($self, $format, $string) = @_;
		925
		926	pack "$format/a*", $string
		927	};
		928
		929	=item json => $array_or_hashref
		930
		931	Encodes the given hash or array reference into a JSON object. Unless you
		932	provide your own JSON object, this means it will be encoded to JSON text
		933	in UTF-8.
		934
		935	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		936	one end of a handle and read them at the other end without using any
		937	additional framing.
		938
		939	The generated JSON text is guaranteed not to contain any newlines: While
		940	this module doesn't need delimiters after or between JSON texts to be
		941	able to read them, many other languages depend on that.
		942
		943	A simple RPC protocol that interoperates easily with others is to send
		944	JSON arrays (or objects, although arrays are usually the better choice as
		945	they mimic how function argument passing works) and a newline after each
		946	JSON text:
		947
		948	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		949	$handle->push_write ("\012");
		950
		951	An AnyEvent::Handle receiver would simply use the C<json> read type and
		952	rely on the fact that the newline will be skipped as leading whitespace:
		953
		954	$handle->push_read (json => sub { my $array = $_[1]; ... });
		955
		956	Other languages could read single lines terminated by a newline and pass
		957	this line into their JSON decoder of choice.
		958
		959	=cut
		960
		961	sub json_coder() {
		962	eval { require JSON::XS; JSON::XS->new->utf8 }
		963	|| do { require JSON; JSON->new->utf8 }
		964	}
		965
		966	register_write_type json => sub {
		967	my ($self, $ref) = @_;
		968
		969	my $json = $self->{json} ||= json_coder;
		970
		971	$json->encode ($ref)
		972	};
		973
		974	=item storable => $reference
		975
		976	Freezes the given reference using L<Storable> and writes it to the
		977	handle. Uses the C<nfreeze> format.
		978
		979	=cut
		980
		981	register_write_type storable => sub {
		982	my ($self, $ref) = @_;
		983
		984	require Storable;
		985
		986	pack "w/a*", Storable::nfreeze ($ref)
		987	};
		988
		989	=back
		990
		991	=item $handle->push_shutdown
		992
		993	Sometimes you know you want to close the socket after writing your data
		994	before it was actually written. One way to do that is to replace your
		995	C<on_drain> handler by a callback that shuts down the socket (and set
		996	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		997	replaces the C<on_drain> callback with:
		998
		999	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1000
		1001	This simply shuts down the write side and signals an EOF condition to the
		1002	the peer.
		1003
		1004	You can rely on the normal read queue and C<on_eof> handling
		1005	afterwards. This is the cleanest way to close a connection.
		1006
		1007	=cut
		1008
		1009	sub push_shutdown {
		1010	my ($self) = @_;
		1011
		1012	delete $self->{low_water_mark};
		1013	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1014	}
		1015
		1016	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		1017
		1018	This function (not method) lets you add your own types to C<push_write>.
		1019	Whenever the given C<type> is used, C<push_write> will invoke the code
		1020	reference with the handle object and the remaining arguments.
		1021
		1022	The code reference is supposed to return a single octet string that will
		1023	be appended to the write buffer.
		1024
		1025	Note that this is a function, and all types registered this way will be
		1026	global, so try to use unique names.
		1027
		1028	=cut
		1029
		1030	#############################################################################
		1031
		1032	=back
		1033
		1034	=head2 READ QUEUE
		1035
		1036	AnyEvent::Handle manages two queues per handle, one for writing and one
		1037	for reading.
		1038
		1039	The read queue is more complex than the write queue. It can be used in two
		1040	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1041	a queue.
		1042
		1043	In the simple case, you just install an C<on_read> callback and whenever
		1044	new data arrives, it will be called. You can then remove some data (if
		1045	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		1046	leave the data there if you want to accumulate more (e.g. when only a
		1047	partial message has been received so far).
		1048
		1049	In the more complex case, you want to queue multiple callbacks. In this
		1050	case, AnyEvent::Handle will call the first queued callback each time new
		1051	data arrives (also the first time it is queued) and removes it when it has
		1052	done its job (see C<push_read>, below).
		1053
		1054	This way you can, for example, push three line-reads, followed by reading
		1055	a chunk of data, and AnyEvent::Handle will execute them in order.
		1056
		1057	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1058	the specified number of bytes which give an XML datagram.
		1059
		1060	# in the default state, expect some header bytes
		1061	$handle->on_read (sub {
		1062	# some data is here, now queue the length-header-read (4 octets)
		1063	shift->unshift_read (chunk => 4, sub {
		1064	# header arrived, decode
		1065	my $len = unpack "N", $_[1];
		1066
		1067	# now read the payload
		1068	shift->unshift_read (chunk => $len, sub {
		1069	my $xml = $_[1];
		1070	# handle xml
		1071	});
		1072	});
		1073	});
		1074
		1075	Example 2: Implement a client for a protocol that replies either with "OK"
		1076	and another line or "ERROR" for the first request that is sent, and 64
		1077	bytes for the second request. Due to the availability of a queue, we can
		1078	just pipeline sending both requests and manipulate the queue as necessary
		1079	in the callbacks.
		1080
		1081	When the first callback is called and sees an "OK" response, it will
		1082	C<unshift> another line-read. This line-read will be queued I<before> the
		1083	64-byte chunk callback.
		1084
		1085	# request one, returns either "OK + extra line" or "ERROR"
		1086	$handle->push_write ("request 1\015\012");
		1087
		1088	# we expect "ERROR" or "OK" as response, so push a line read
		1089	$handle->push_read (line => sub {
		1090	# if we got an "OK", we have to _prepend_ another line,
		1091	# so it will be read before the second request reads its 64 bytes
		1092	# which are already in the queue when this callback is called
		1093	# we don't do this in case we got an error
		1094	if ($_[1] eq "OK") {
		1095	$_[0]->unshift_read (line => sub {
		1096	my $response = $_[1];
		1097	...
		1098	});
38	}	1099	}
39	});	1100	});
40		1101
41	# or use the constructor to pass the callback:	1102	# request two, simply returns 64 octets
		1103	$handle->push_write ("request 2\015\012");
42		1104
43	my $ae_fh2 =	1105	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1106	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1107	my $response = $_[1];
46	on_eof => sub {	1108	...
47	$cv->broadcast;	1109	});
48	},	1110
49	on_readline => sub {	1111	=over 4
50	my ($ae_fh, @lines) = @_;	1112
51	for (@lines) {	1113	=cut
52	chomp;	1114
53	print "Line: $_";	1115	sub _drain_rbuf {
		1116	my ($self) = @_;
		1117
		1118	# avoid recursion
		1119	return if $self->{_skip_drain_rbuf};
		1120	local $self->{_skip_drain_rbuf} = 1;
		1121
		1122	while () {
		1123	# we need to use a separate tls read buffer, as we must not receive data while
		1124	# we are draining the buffer, and this can only happen with TLS.
		1125	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1126	if exists $self->{_tls_rbuf};
		1127
		1128	my $len = length $self->{rbuf};
		1129
		1130	if (my $cb = shift @{ $self->{_queue} }) {
		1131	unless ($cb->($self)) {
		1132	# no progress can be made
		1133	# (not enough data and no data forthcoming)
		1134	$self->_error (Errno::EPIPE, 1), return
		1135	if $self->{_eof};
		1136
		1137	unshift @{ $self->{_queue} }, $cb;
54	}	1138	last;
55	}	1139	}
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}) {	1140	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1141	last unless $len;
122		1142
		1143	$self->{on_read}($self);
		1144
		1145	if (
		1146	$len == length $self->{rbuf} # if no data has been consumed
		1147	&& !@{ $self->{_queue} } # and the queue is still empty
		1148	&& $self->{on_read} # but we still have on_read
		1149	) {
		1150	# no further data will arrive
		1151	# so no progress can be made
		1152	$self->_error (Errno::EPIPE, 1), return
		1153	if $self->{_eof};
		1154
		1155	last; # more data might arrive
		1156	}
		1157	} else {
		1158	# read side becomes idle
		1159	delete $self->{_rw} unless $self->{tls};
		1160	last;
		1161	}
		1162	}
		1163
123	} elsif ($self->{on_eof}) {	1164	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1165	$self->{on_eof}
		1166	? $self->{on_eof}($self)
		1167	: $self->_error (0, 1, "Unexpected end-of-file");
125		1168
126	} elsif ($self->{on_error}) {	1169	return;
127	$self->on_eof ($self->{on_error});
128	}	1170	}
129		1171
130	return $self	1172	if (
131	}	1173	defined $self->{rbuf_max}
		1174	&& $self->{rbuf_max} < length $self->{rbuf}
		1175	) {
		1176	$self->_error (Errno::ENOSPC, 1), return;
		1177	}
132		1178
133	=item B<fh>	1179	# may need to restart read watcher
		1180	unless ($self->{_rw}) {
		1181	$self->start_read
		1182	if $self->{on_read} || @{ $self->{_queue} };
		1183	}
		1184	}
134		1185
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1186	=item $handle->on_read ($cb)
136		1187
137	=cut	1188	This replaces the currently set C<on_read> callback, or clears it (when
138		1189	the new callback is C<undef>). See the description of C<on_read> in the
139	sub fh { $_[0]->{fh} }	1190	constructor.
140
141	=item B<on_read ($callback)>
142
143	This method installs a C<$callback> that will be called
144	when new data arrived. You can access the read buffer via the C<rbuf>
145	method (see below).
146
147	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
148		1191
149	=cut	1192	=cut
150		1193
151	sub on_read {	1194	sub on_read {
152	my ($self, $cb) = @_;	1195	my ($self, $cb) = @_;
		1196
153	$self->{on_read} = $cb;	1197	$self->{on_read} = $cb;
		1198	$self->_drain_rbuf if $cb;
		1199	}
154		1200
155	unless (defined $self->{on_read}) {	1201	=item $handle->rbuf
156	delete $self->{on_read_w};	1202
		1203	Returns the read buffer (as a modifiable lvalue).
		1204
		1205	You can access the read buffer directly as the C<< ->{rbuf} >>
		1206	member, if you want. However, the only operation allowed on the
		1207	read buffer (apart from looking at it) is removing data from its
		1208	beginning. Otherwise modifying or appending to it is not allowed and will
		1209	lead to hard-to-track-down bugs.
		1210
		1211	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1212	C<push_read> or C<unshift_read> methods are used. The other read methods
		1213	automatically manage the read buffer.
		1214
		1215	=cut
		1216
		1217	sub rbuf : lvalue {
		1218	$_[0]{rbuf}
		1219	}
		1220
		1221	=item $handle->push_read ($cb)
		1222
		1223	=item $handle->unshift_read ($cb)
		1224
		1225	Append the given callback to the end of the queue (C<push_read>) or
		1226	prepend it (C<unshift_read>).
		1227
		1228	The callback is called each time some additional read data arrives.
		1229
		1230	It must check whether enough data is in the read buffer already.
		1231
		1232	If not enough data is available, it must return the empty list or a false
		1233	value, in which case it will be called repeatedly until enough data is
		1234	available (or an error condition is detected).
		1235
		1236	If enough data was available, then the callback must remove all data it is
		1237	interested in (which can be none at all) and return a true value. After returning
		1238	true, it will be removed from the queue.
		1239
		1240	=cut
		1241
		1242	our %RH;
		1243
		1244	sub register_read_type($$) {
		1245	$RH{$_[0]} = $_[1];
		1246	}
		1247
		1248	sub push_read {
		1249	my $self = shift;
		1250	my $cb = pop;
		1251
		1252	if (@_) {
		1253	my $type = shift;
		1254
		1255	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		1256	->($self, $cb, @_);
		1257	}
		1258
		1259	push @{ $self->{_queue} }, $cb;
		1260	$self->_drain_rbuf;
		1261	}
		1262
		1263	sub unshift_read {
		1264	my $self = shift;
		1265	my $cb = pop;
		1266
		1267	if (@_) {
		1268	my $type = shift;
		1269
		1270	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1271	->($self, $cb, @_);
		1272	}
		1273
		1274	unshift @{ $self->{_queue} }, $cb;
		1275	$self->_drain_rbuf;
		1276	}
		1277
		1278	=item $handle->push_read (type => @args, $cb)
		1279
		1280	=item $handle->unshift_read (type => @args, $cb)
		1281
		1282	Instead of providing a callback that parses the data itself you can chose
		1283	between a number of predefined parsing formats, for chunks of data, lines
		1284	etc.
		1285
		1286	Predefined types are (if you have ideas for additional types, feel free to
		1287	drop by and tell us):
		1288
		1289	=over 4
		1290
		1291	=item chunk => $octets, $cb->($handle, $data)
		1292
		1293	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1294	data read to the callback. The callback will never be called with less
		1295	data.
		1296
		1297	Example: read 2 bytes.
		1298
		1299	$handle->push_read (chunk => 2, sub {
		1300	warn "yay ", unpack "H*", $_[1];
		1301	});
		1302
		1303	=cut
		1304
		1305	register_read_type chunk => sub {
		1306	my ($self, $cb, $len) = @_;
		1307
		1308	sub {
		1309	$len <= length $_[0]{rbuf} or return;
		1310	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1311	1
		1312	}
		1313	};
		1314
		1315	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1316
		1317	The callback will be called only once a full line (including the end of
		1318	line marker, C<$eol>) has been read. This line (excluding the end of line
		1319	marker) will be passed to the callback as second argument (C<$line>), and
		1320	the end of line marker as the third argument (C<$eol>).
		1321
		1322	The end of line marker, C<$eol>, can be either a string, in which case it
		1323	will be interpreted as a fixed record end marker, or it can be a regex
		1324	object (e.g. created by C<qr>), in which case it is interpreted as a
		1325	regular expression.
		1326
		1327	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1328	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1329	protocols).
		1330
		1331	Partial lines at the end of the stream will never be returned, as they are
		1332	not marked by the end of line marker.
		1333
		1334	=cut
		1335
		1336	register_read_type line => sub {
		1337	my ($self, $cb, $eol) = @_;
		1338
		1339	if (@_ < 3) {
		1340	# this is more than twice as fast as the generic code below
		1341	sub {
		1342	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1343
		1344	$cb->($_[0], $1, $2);
		1345	1
		1346	}
		1347	} else {
		1348	$eol = quotemeta $eol unless ref $eol;
		1349	$eol = qr|^(.*?)($eol)|s;
		1350
		1351	sub {
		1352	$_[0]{rbuf} =~ s/$eol// or return;
		1353
		1354	$cb->($_[0], $1, $2);
		1355	1
		1356	}
		1357	}
		1358	};
		1359
		1360	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1361
		1362	Makes a regex match against the regex object C<$accept> and returns
		1363	everything up to and including the match.
		1364
		1365	Example: read a single line terminated by '\n'.
		1366
		1367	$handle->push_read (regex => qr<\n>, sub { ... });
		1368
		1369	If C<$reject> is given and not undef, then it determines when the data is
		1370	to be rejected: it is matched against the data when the C<$accept> regex
		1371	does not match and generates an C<EBADMSG> error when it matches. This is
		1372	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1373	receive buffer overflow).
		1374
		1375	Example: expect a single decimal number followed by whitespace, reject
		1376	anything else (not the use of an anchor).
		1377
		1378	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1379
		1380	If C<$skip> is given and not C<undef>, then it will be matched against
		1381	the receive buffer when neither C<$accept> nor C<$reject> match,
		1382	and everything preceding and including the match will be accepted
		1383	unconditionally. This is useful to skip large amounts of data that you
		1384	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1385	have to start matching from the beginning. This is purely an optimisation
		1386	and is usually worth only when you expect more than a few kilobytes.
		1387
		1388	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1389	expect the header to be very large (it isn't in practise, but...), we use
		1390	a skip regex to skip initial portions. The skip regex is tricky in that
		1391	it only accepts something not ending in either \015 or \012, as these are
		1392	required for the accept regex.
		1393
		1394	$handle->push_read (regex =>
		1395	qr<\015\012\015\012>,
		1396	undef, # no reject
		1397	qr<^.*[^\015\012]>,
		1398	sub { ... });
		1399
		1400	=cut
		1401
		1402	register_read_type regex => sub {
		1403	my ($self, $cb, $accept, $reject, $skip) = @_;
		1404
		1405	my $data;
		1406	my $rbuf = \$self->{rbuf};
		1407
		1408	sub {
		1409	# accept
		1410	if ($$rbuf =~ $accept) {
		1411	$data .= substr $$rbuf, 0, $+[0], "";
		1412	$cb->($self, $data);
		1413	return 1;
		1414	}
		1415
		1416	# reject
		1417	if ($reject && $$rbuf =~ $reject) {
		1418	$self->_error (Errno::EBADMSG);
		1419	}
		1420
		1421	# skip
		1422	if ($skip && $$rbuf =~ $skip) {
		1423	$data .= substr $$rbuf, 0, $+[0], "";
		1424	}
		1425
		1426	()
		1427	}
		1428	};
		1429
		1430	=item netstring => $cb->($handle, $string)
		1431
		1432	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1433
		1434	Throws an error with C<$!> set to EBADMSG on format violations.
		1435
		1436	=cut
		1437
		1438	register_read_type netstring => sub {
		1439	my ($self, $cb) = @_;
		1440
		1441	sub {
		1442	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1443	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1444	$self->_error (Errno::EBADMSG);
		1445	}
157	return;	1446	return;
		1447	}
		1448
		1449	my $len = $1;
		1450
		1451	$self->unshift_read (chunk => $len, sub {
		1452	my $string = $_[1];
		1453	$_[0]->unshift_read (chunk => 1, sub {
		1454	if ($_[1] eq ",") {
		1455	$cb->($_[0], $string);
		1456	} else {
		1457	$self->_error (Errno::EBADMSG);
		1458	}
		1459	});
		1460	});
		1461
		1462	1
		1463	}
		1464	};
		1465
		1466	=item packstring => $format, $cb->($handle, $string)
		1467
		1468	An octet string prefixed with an encoded length. The encoding C<$format>
		1469	uses the same format as a Perl C<pack> format, but must specify a single
		1470	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1471	optional C<!>, C<< < >> or C<< > >> modifier).
		1472
		1473	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1474	EPP uses a prefix of C<N> (4 octtes).
		1475
		1476	Example: read a block of data prefixed by its length in BER-encoded
		1477	format (very efficient).
		1478
		1479	$handle->push_read (packstring => "w", sub {
		1480	my ($handle, $data) = @_;
158	}	1481	});
159		1482
160	$self->{on_read_w} =	1483	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1484
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1485	register_read_type packstring => sub {
		1486	my ($self, $cb, $format) = @_;
		1487
		1488	sub {
		1489	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1490	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1491	or return;
		1492
		1493	$format = length pack $format, $len;
		1494
		1495	# bypass unshift if we already have the remaining chunk
		1496	if ($format + $len <= length $_[0]{rbuf}) {
		1497	my $data = substr $_[0]{rbuf}, $format, $len;
		1498	substr $_[0]{rbuf}, 0, $format + $len, "";
		1499	$cb->($_[0], $data);
		1500	} else {
		1501	# remove prefix
		1502	substr $_[0]{rbuf}, 0, $format, "";
		1503
		1504	# read remaining chunk
		1505	$_[0]->unshift_read (chunk => $len, $cb);
		1506	}
		1507
		1508	1
		1509	}
		1510	};
		1511
		1512	=item json => $cb->($handle, $hash_or_arrayref)
		1513
		1514	Reads a JSON object or array, decodes it and passes it to the
		1515	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1516
		1517	If a C<json> object was passed to the constructor, then that will be used
		1518	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1519
		1520	This read type uses the incremental parser available with JSON version
		1521	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1522	dependency on your own: this module will load the JSON module, but
		1523	AnyEvent does not depend on it itself.
		1524
		1525	Since JSON texts are fully self-delimiting, the C<json> read and write
		1526	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1527	the C<json> write type description, above, for an actual example.
		1528
		1529	=cut
		1530
		1531	register_read_type json => sub {
		1532	my ($self, $cb) = @_;
		1533
		1534	my $json = $self->{json} ||= json_coder;
		1535
		1536	my $data;
163	my $rbuf_len = length $self->{rbuf};	1537	my $rbuf = \$self->{rbuf};
164	my $l;	1538
165	if (defined $self->{read_size}) {	1539	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1540	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1541
		1542	if ($ref) {
		1543	$self->{rbuf} = $json->incr_text;
		1544	$json->incr_text = "";
		1545	$cb->($self, $ref);
		1546
		1547	1
		1548	} elsif ($@) {
		1549	# error case
		1550	$json->incr_skip;
		1551
		1552	$self->{rbuf} = $json->incr_text;
		1553	$json->incr_text = "";
		1554
		1555	$self->_error (Errno::EBADMSG);
		1556
		1557	()
		1558	} else {
		1559	$self->{rbuf} = "";
		1560
		1561	()
		1562	}
		1563	}
		1564	};
		1565
		1566	=item storable => $cb->($handle, $ref)
		1567
		1568	Deserialises a L<Storable> frozen representation as written by the
		1569	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1570	data).
		1571
		1572	Raises C<EBADMSG> error if the data could not be decoded.
		1573
		1574	=cut
		1575
		1576	register_read_type storable => sub {
		1577	my ($self, $cb) = @_;
		1578
		1579	require Storable;
		1580
		1581	sub {
		1582	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1583	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1584	or return;
		1585
		1586	my $format = length pack "w", $len;
		1587
		1588	# bypass unshift if we already have the remaining chunk
		1589	if ($format + $len <= length $_[0]{rbuf}) {
		1590	my $data = substr $_[0]{rbuf}, $format, $len;
		1591	substr $_[0]{rbuf}, 0, $format + $len, "";
		1592	$cb->($_[0], Storable::thaw ($data));
		1593	} else {
		1594	# remove prefix
		1595	substr $_[0]{rbuf}, 0, $format, "";
		1596
		1597	# read remaining chunk
		1598	$_[0]->unshift_read (chunk => $len, sub {
		1599	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1600	$cb->($_[0], $ref);
		1601	} else {
		1602	$self->_error (Errno::EBADMSG);
		1603	}
		1604	});
		1605	}
		1606
		1607	1
		1608	}
		1609	};
		1610
		1611	=back
		1612
		1613	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1614
		1615	This function (not method) lets you add your own types to C<push_read>.
		1616
		1617	Whenever the given C<type> is used, C<push_read> will invoke the code
		1618	reference with the handle object, the callback and the remaining
		1619	arguments.
		1620
		1621	The code reference is supposed to return a callback (usually a closure)
		1622	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1623
		1624	It should invoke the passed callback when it is done reading (remember to
		1625	pass C<$handle> as first argument as all other callbacks do that).
		1626
		1627	Note that this is a function, and all types registered this way will be
		1628	global, so try to use unique names.
		1629
		1630	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1631	search for C<register_read_type>)).
		1632
		1633	=item $handle->stop_read
		1634
		1635	=item $handle->start_read
		1636
		1637	In rare cases you actually do not want to read anything from the
		1638	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1639	any queued callbacks will be executed then. To start reading again, call
		1640	C<start_read>.
		1641
		1642	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1643	you change the C<on_read> callback or push/unshift a read callback, and it
		1644	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1645	there are any read requests in the queue.
		1646
		1647	These methods will have no effect when in TLS mode (as TLS doesn't support
		1648	half-duplex connections).
		1649
		1650	=cut
		1651
		1652	sub stop_read {
		1653	my ($self) = @_;
		1654
		1655	delete $self->{_rw} unless $self->{tls};
		1656	}
		1657
		1658	sub start_read {
		1659	my ($self) = @_;
		1660
		1661	unless ($self->{_rw} || $self->{_eof}) {
		1662	Scalar::Util::weaken $self;
		1663
		1664	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1665	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1666	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1667
		1668	if ($len > 0) {
		1669	$self->{_activity} = $self->{_ractivity} = AE::now;
		1670
		1671	if ($self->{tls}) {
		1672	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1673
		1674	&_dotls ($self);
		1675	} else {
		1676	$self->_drain_rbuf;
		1677	}
		1678
		1679	} elsif (defined $len) {
		1680	delete $self->{_rw};
		1681	$self->{_eof} = 1;
		1682	$self->_drain_rbuf;
		1683
		1684	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1685	return $self->_error ($!, 1);
		1686	}
		1687	};
		1688	}
		1689	}
		1690
		1691	our $ERROR_SYSCALL;
		1692	our $ERROR_WANT_READ;
		1693
		1694	sub _tls_error {
		1695	my ($self, $err) = @_;
		1696
		1697	return $self->_error ($!, 1)
		1698	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1699
		1700	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1701
		1702	# reduce error string to look less scary
		1703	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1704
		1705	if ($self->{_on_starttls}) {
		1706	(delete $self->{_on_starttls})->($self, undef, $err);
		1707	&_freetls;
		1708	} else {
		1709	&_freetls;
		1710	$self->_error (Errno::EPROTO, 1, $err);
		1711	}
		1712	}
		1713
		1714	# poll the write BIO and send the data if applicable
		1715	# also decode read data if possible
		1716	# this is basiclaly our TLS state machine
		1717	# more efficient implementations are possible with openssl,
		1718	# but not with the buggy and incomplete Net::SSLeay.
		1719	sub _dotls {
		1720	my ($self) = @_;
		1721
		1722	my $tmp;
		1723
		1724	if (length $self->{_tls_wbuf}) {
		1725	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1726	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1727	}
		1728
		1729	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1730	return $self->_tls_error ($tmp)
		1731	if $tmp != $ERROR_WANT_READ
		1732	&& ($tmp != $ERROR_SYSCALL || $!);
		1733	}
		1734
		1735	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1736	unless (length $tmp) {
		1737	$self->{_on_starttls}
		1738	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1739	&_freetls;
		1740
		1741	if ($self->{on_stoptls}) {
		1742	$self->{on_stoptls}($self);
		1743	return;
168	} else {	1744	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1745	# 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};	1746	delete $self->{_rw};
177
178	} elsif ($l == 0) {
179	$self->{on_eof}->($self) if $self->{on_eof};
180	delete $self->{on_read_w};
181
182	} else {
183	$self->{on_read}->($self);
184	}
185	});
186	}
187
188	=item B<on_error ($callback)>
189
190	Whenever a read or write operation resulted in an error the C<$callback>
191	will be called.
192
193	The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself.
194	The error is given as errno in C<$!>.
195
196	=cut
197
198	sub on_error {
199	$_[0]->{on_error} = $_[1];
200	}
201
202	=item B<on_eof ($callback)>
203
204	Installs the C<$callback> that will be called when the end of file is
205	encountered in a read operation this C<$callback> will be called. The first
206	argument will be the L<AnyEvent::Handle> object itself.
207
208	=cut
209
210	sub on_eof {
211	$_[0]->{on_eof} = $_[1];
212	}
213
214	=item B<rbuf>
215
216	Returns a reference to the read buffer.
217
218	NOTE: The read buffer should only be used or modified if the C<on_read>
219	method is used directly. The C<read> and C<readlines> methods will provide
220	the read data to their callbacks.
221
222	=cut
223
224	sub rbuf : lvalue {
225	$_[0]->{rbuf}
226	}
227
228	=item B<read ($len, $callback)>
229
230	Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
231	if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
232	object itself and the second argument the read data.
233
234	NOTE: This method will override any callbacks installed via the C<on_read> method.
235
236	=cut
237
238	sub read {
239	my ($self, $len, $cb) = @_;
240
241	$self->{read_cb} = $cb;
242	my $old_blk_size = $self->{read_block_size};
243	$self->{read_block_size} = $len;
244
245	$self->on_read (sub {
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247
248	if ($len == length $_[0]->{rbuf}) {
249	$_[0]->{read_block_size} = $old_blk_size;
250	$_[0]->on_read (undef);
251	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
252	}
253	});
254	}
255
256	=item B<readlines ($callback)>
257
258	=item B<readlines ($sep, $callback)>
259
260	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
261	if C<$sep> is not provided. C<$sep> will be used as "line" seperator.
262
263	The C<$callback> will be called when at least one
264	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
265	object itself and the rest of the arguments will be the read lines.
266
267	NOTE: This method will override any callbacks installed via the C<on_read> method.
268
269	=cut
270
271	sub readlines {
272	my ($self, $sep, $cb) = @_;
273
274	if (ref $sep) {
275	$cb = $sep;
276	$sep = "\n";
277
278	} elsif (not defined $sep) {
279	$sep = "\n";
280	}
281
282	my $sep_len = length $sep;
283
284	$self->{on_readline} = $cb;
285
286	$self->on_read (sub {
287	my @lines;
288	my $rb = \$_[0]->{rbuf};
289	my $pos;
290	while (($pos = index ($$rb, $sep)) >= 0) {
291	push @lines, substr $$rb, 0, $pos + $sep_len, '';
292	}
293	$self->{on_readline}->($_[0], @lines);
294	});
295	}
296
297	=item B<write ($data)>
298
299	=item B<write ($callback)>
300
301	=item B<write ($data, $callback)>
302
303	This method will write C<$data> to the filehandle and call the C<$callback>
304	afterwards. If only C<$callback> is provided it will be called when the
305	write buffer becomes empty the next time (or immediately if it already is empty).
306
307	=cut
308
309	sub write {
310	my ($self, $data, $cb) = @_;
311	if (ref $data) { $cb = $data; undef $data }
312	push @{$self->{write_bufs}}, [$data, $cb];
313	$self->_check_writer;
314	}
315
316	sub _check_writer {
317	my ($self) = @_;
318
319	if ($self->{write_w}) {
320	unless ($self->{write_cb}) {
321	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
322	my $wba = shift @{$self->{write_bufs}};
323	$self->{wbuf} .= $wba->[0];	1747	$self->{_eof} = 1;
324	}	1748	}
325	}	1749	}
326	return;	1750
		1751	$self->{_tls_rbuf} .= $tmp;
		1752	$self->_drain_rbuf;
		1753	$self->{tls} or return; # tls session might have gone away in callback
		1754	}
		1755
		1756	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1757	return $self->_tls_error ($tmp)
		1758	if $tmp != $ERROR_WANT_READ
		1759	&& ($tmp != $ERROR_SYSCALL || $!);
		1760
		1761	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1762	$self->{wbuf} .= $tmp;
		1763	$self->_drain_wbuf;
		1764	}
		1765
		1766	$self->{_on_starttls}
		1767	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1768	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1769	}
		1770
		1771	=item $handle->starttls ($tls[, $tls_ctx])
		1772
		1773	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1774	object is created, you can also do that at a later time by calling
		1775	C<starttls>.
		1776
		1777	Starting TLS is currently an asynchronous operation - when you push some
		1778	write data and then call C<< ->starttls >> then TLS negotiation will start
		1779	immediately, after which the queued write data is then sent.
		1780
		1781	The first argument is the same as the C<tls> constructor argument (either
		1782	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1783
		1784	The second argument is the optional C<AnyEvent::TLS> object that is used
		1785	when AnyEvent::Handle has to create its own TLS connection object, or
		1786	a hash reference with C<< key => value >> pairs that will be used to
		1787	construct a new context.
		1788
		1789	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1790	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1791	changed to your liking. Note that the handshake might have already started
		1792	when this function returns.
		1793
		1794	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1795	handshakes on the same stream. Best do not attempt to use the stream after
		1796	stopping TLS.
		1797
		1798	=cut
		1799
		1800	our %TLS_CACHE; #TODO not yet documented, should we?
		1801
		1802	sub starttls {
		1803	my ($self, $tls, $ctx) = @_;
		1804
		1805	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1806	if $self->{tls};
		1807
		1808	$self->{tls} = $tls;
		1809	$self->{tls_ctx} = $ctx if @_ > 2;
		1810
		1811	return unless $self->{fh};
		1812
		1813	require Net::SSLeay;
		1814
		1815	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1816	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1817
		1818	$tls = delete $self->{tls};
		1819	$ctx = $self->{tls_ctx};
		1820
		1821	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1822
		1823	if ("HASH" eq ref $ctx) {
		1824	require AnyEvent::TLS;
		1825
		1826	if ($ctx->{cache}) {
		1827	my $key = $ctx+0;
		1828	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1829	} else {
		1830	$ctx = new AnyEvent::TLS %$ctx;
		1831	}
		1832	}
327	}	1833
		1834	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1835	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
328		1836
329	my $wba = shift @{$self->{write_bufs}}	1837	# basically, this is deep magic (because SSL_read should have the same issues)
330	or return;	1838	# but the openssl maintainers basically said: "trust us, it just works".
		1839	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1840	# and mismaintained ssleay-module doesn't even offer them).
		1841	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1842	#
		1843	# in short: this is a mess.
		1844	#
		1845	# note that we do not try to keep the length constant between writes as we are required to do.
		1846	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1847	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1848	# have identity issues in that area.
		1849	# Net::SSLeay::CTX_set_mode ($ssl,
		1850	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1851	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1852	Net::SSLeay::CTX_set_mode ($tls, 1|2);
331		1853
332	unless (defined $wba->[0]) {	1854	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
333	$wba->[1]->($self) if $wba->[1];	1855	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
334	$self->_check_writer;	1856
335	return;	1857	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1858
		1859	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1860
		1861	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1862	if $self->{on_starttls};
		1863
		1864	&_dotls; # need to trigger the initial handshake
		1865	$self->start_read; # make sure we actually do read
		1866	}
		1867
		1868	=item $handle->stoptls
		1869
		1870	Shuts down the SSL connection - this makes a proper EOF handshake by
		1871	sending a close notify to the other side, but since OpenSSL doesn't
		1872	support non-blocking shut downs, it is not guarenteed that you can re-use
		1873	the stream afterwards.
		1874
		1875	=cut
		1876
		1877	sub stoptls {
		1878	my ($self) = @_;
		1879
		1880	if ($self->{tls}) {
		1881	Net::SSLeay::shutdown ($self->{tls});
		1882
		1883	&_dotls;
		1884
		1885	# # we don't give a shit. no, we do, but we can't. no...#d#
		1886	# # we, we... have to use openssl :/#d#
		1887	# &_freetls;#d#
		1888	}
		1889	}
		1890
		1891	sub _freetls {
		1892	my ($self) = @_;
		1893
		1894	return unless $self->{tls};
		1895
		1896	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1897	if $self->{tls} > 0;
336	}	1898
		1899	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1900	}
337		1901
338	$self->{wbuf} = $wba->[0];	1902	sub DESTROY {
339	$self->{write_cb} = $wba->[1];	1903	my ($self) = @_;
340		1904
341	$self->{write_w} =	1905	&_freetls;
342	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1906
		1907	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1908
		1909	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1910	my $fh = delete $self->{fh};
		1911	my $wbuf = delete $self->{wbuf};
		1912
		1913	my @linger;
		1914
		1915	push @linger, AE::io $fh, 1, sub {
343	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1916	my $len = syswrite $fh, $wbuf, length $wbuf;
344		1917
345	if (not defined $l) {	1918	if ($len > 0) {
346	return if $! == EAGAIN || $! == EINTR;	1919	substr $wbuf, 0, $len, "";
347	delete $self->{write_w};
348	$self->{on_error}->($self) if $self->{on_error};
349
350	} else {	1920	} else {
351	substr $self->{wbuf}, 0, $l, '';	1921	@linger = (); # end
352
353	if (length ($self->{wbuf}) == 0) {
354	$self->{write_cb}->($self) if $self->{write_cb};
355
356	delete $self->{write_w};
357	delete $self->{wbuf};
358	delete $self->{write_cb};
359
360	$self->_check_writer;
361	}
362	}	1922	}
363	});	1923	};
		1924	push @linger, AE::timer $linger, 0, sub {
		1925	@linger = ();
		1926	};
		1927	}
		1928	}
		1929
		1930	=item $handle->destroy
		1931
		1932	Shuts down the handle object as much as possible - this call ensures that
		1933	no further callbacks will be invoked and as many resources as possible
		1934	will be freed. Any method you will call on the handle object after
		1935	destroying it in this way will be silently ignored (and it will return the
		1936	empty list).
		1937
		1938	Normally, you can just "forget" any references to an AnyEvent::Handle
		1939	object and it will simply shut down. This works in fatal error and EOF
		1940	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1941	callback, so when you want to destroy the AnyEvent::Handle object from
		1942	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1943	that case.
		1944
		1945	Destroying the handle object in this way has the advantage that callbacks
		1946	will be removed as well, so if those are the only reference holders (as
		1947	is common), then one doesn't need to do anything special to break any
		1948	reference cycles.
		1949
		1950	The handle might still linger in the background and write out remaining
		1951	data, as specified by the C<linger> option, however.
		1952
		1953	=cut
		1954
		1955	sub destroy {
		1956	my ($self) = @_;
		1957
		1958	$self->DESTROY;
		1959	%$self = ();
		1960	bless $self, "AnyEvent::Handle::destroyed";
		1961	}
		1962
		1963	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		1964	#nop
		1965	}
		1966
		1967	=item AnyEvent::Handle::TLS_CTX
		1968
		1969	This function creates and returns the AnyEvent::TLS object used by default
		1970	for TLS mode.
		1971
		1972	The context is created by calling L<AnyEvent::TLS> without any arguments.
		1973
		1974	=cut
		1975
		1976	our $TLS_CTX;
		1977
		1978	sub TLS_CTX() {
		1979	$TLS_CTX ||= do {
		1980	require AnyEvent::TLS;
		1981
		1982	new AnyEvent::TLS
		1983	}
364	}	1984	}
365		1985
366	=back	1986	=back
367		1987
		1988
		1989	=head1 NONFREQUENTLY ASKED QUESTIONS
		1990
		1991	=over 4
		1992
		1993	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1994	still get further invocations!
		1995
		1996	That's because AnyEvent::Handle keeps a reference to itself when handling
		1997	read or write callbacks.
		1998
		1999	It is only safe to "forget" the reference inside EOF or error callbacks,
		2000	from within all other callbacks, you need to explicitly call the C<<
		2001	->destroy >> method.
		2002
		2003	=item I get different callback invocations in TLS mode/Why can't I pause
		2004	reading?
		2005
		2006	Unlike, say, TCP, TLS connections do not consist of two independent
		2007	communication channels, one for each direction. Or put differently. The
		2008	read and write directions are not independent of each other: you cannot
		2009	write data unless you are also prepared to read, and vice versa.
		2010
		2011	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2012	callback invocations when you are not expecting any read data - the reason
		2013	is that AnyEvent::Handle always reads in TLS mode.
		2014
		2015	During the connection, you have to make sure that you always have a
		2016	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2017	connection (or when you no longer want to use it) you can call the
		2018	C<destroy> method.
		2019
		2020	=item How do I read data until the other side closes the connection?
		2021
		2022	If you just want to read your data into a perl scalar, the easiest way
		2023	to achieve this is by setting an C<on_read> callback that does nothing,
		2024	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2025	will be in C<$_[0]{rbuf}>:
		2026
		2027	$handle->on_read (sub { });
		2028	$handle->on_eof (undef);
		2029	$handle->on_error (sub {
		2030	my $data = delete $_[0]{rbuf};
		2031	});
		2032
		2033	The reason to use C<on_error> is that TCP connections, due to latencies
		2034	and packets loss, might get closed quite violently with an error, when in
		2035	fact, all data has been received.
		2036
		2037	It is usually better to use acknowledgements when transferring data,
		2038	to make sure the other side hasn't just died and you got the data
		2039	intact. This is also one reason why so many internet protocols have an
		2040	explicit QUIT command.
		2041
		2042	=item I don't want to destroy the handle too early - how do I wait until
		2043	all data has been written?
		2044
		2045	After writing your last bits of data, set the C<on_drain> callback
		2046	and destroy the handle in there - with the default setting of
		2047	C<low_water_mark> this will be called precisely when all data has been
		2048	written to the socket:
		2049
		2050	$handle->push_write (...);
		2051	$handle->on_drain (sub {
		2052	warn "all data submitted to the kernel\n";
		2053	undef $handle;
		2054	});
		2055
		2056	If you just want to queue some data and then signal EOF to the other side,
		2057	consider using C<< ->push_shutdown >> instead.
		2058
		2059	=item I want to contact a TLS/SSL server, I don't care about security.
		2060
		2061	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2062	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2063	parameter:
		2064
		2065	tcp_connect $host, $port, sub {
		2066	my ($fh) = @_;
		2067
		2068	my $handle = new AnyEvent::Handle
		2069	fh => $fh,
		2070	tls => "connect",
		2071	on_error => sub { ... };
		2072
		2073	$handle->push_write (...);
		2074	};
		2075
		2076	=item I want to contact a TLS/SSL server, I do care about security.
		2077
		2078	Then you should additionally enable certificate verification, including
		2079	peername verification, if the protocol you use supports it (see
		2080	L<AnyEvent::TLS>, C<verify_peername>).
		2081
		2082	E.g. for HTTPS:
		2083
		2084	tcp_connect $host, $port, sub {
		2085	my ($fh) = @_;
		2086
		2087	my $handle = new AnyEvent::Handle
		2088	fh => $fh,
		2089	peername => $host,
		2090	tls => "connect",
		2091	tls_ctx => { verify => 1, verify_peername => "https" },
		2092	...
		2093
		2094	Note that you must specify the hostname you connected to (or whatever
		2095	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2096	peername verification will be done.
		2097
		2098	The above will use the system-dependent default set of trusted CA
		2099	certificates. If you want to check against a specific CA, add the
		2100	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2101
		2102	tls_ctx => {
		2103	verify => 1,
		2104	verify_peername => "https",
		2105	ca_file => "my-ca-cert.pem",
		2106	},
		2107
		2108	=item I want to create a TLS/SSL server, how do I do that?
		2109
		2110	Well, you first need to get a server certificate and key. You have
		2111	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2112	self-signed certificate (cheap. check the search engine of your choice,
		2113	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2114	nice program for that purpose).
		2115
		2116	Then create a file with your private key (in PEM format, see
		2117	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2118	file should then look like this:
		2119
		2120	-----BEGIN RSA PRIVATE KEY-----
		2121	...header data
		2122	... lots of base64'y-stuff
		2123	-----END RSA PRIVATE KEY-----
		2124
		2125	-----BEGIN CERTIFICATE-----
		2126	... lots of base64'y-stuff
		2127	-----END CERTIFICATE-----
		2128
		2129	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2130	specify this file as C<cert_file>:
		2131
		2132	tcp_server undef, $port, sub {
		2133	my ($fh) = @_;
		2134
		2135	my $handle = new AnyEvent::Handle
		2136	fh => $fh,
		2137	tls => "accept",
		2138	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2139	...
		2140
		2141	When you have intermediate CA certificates that your clients might not
		2142	know about, just append them to the C<cert_file>.
		2143
		2144	=back
		2145
		2146
		2147	=head1 SUBCLASSING AnyEvent::Handle
		2148
		2149	In many cases, you might want to subclass AnyEvent::Handle.
		2150
		2151	To make this easier, a given version of AnyEvent::Handle uses these
		2152	conventions:
		2153
		2154	=over 4
		2155
		2156	=item * all constructor arguments become object members.
		2157
		2158	At least initially, when you pass a C<tls>-argument to the constructor it
		2159	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2160	mutated later on (for example C<tls> will hold the TLS connection object).
		2161
		2162	=item * other object member names are prefixed with an C<_>.
		2163
		2164	All object members not explicitly documented (internal use) are prefixed
		2165	with an underscore character, so the remaining non-C<_>-namespace is free
		2166	for use for subclasses.
		2167
		2168	=item * all members not documented here and not prefixed with an underscore
		2169	are free to use in subclasses.
		2170
		2171	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2172	member variables, but thats just life, at least it is documented.
		2173
		2174	=back
		2175
368	=head1 AUTHOR	2176	=head1 AUTHOR
369		2177
370	Robin Redeker, C<< <elmex at ta-sa.org> >>	2178	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
371		2179
372	=cut	2180	=cut
373		2181
374	1; # End of AnyEvent::Handle	2182	1; # End of AnyEvent::Handle

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