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Revision 1.5 by elmex, Mon Apr 28 08:01:05 2008 UTC vs.
Revision 1.191 by root, Sun Jan 31 22:33:45 2010 UTC

1	package AnyEvent::Handle;
2
3	use warnings;
4	use strict;
5
6	use AnyEvent;
7	use IO::Handle;
8	use Errno qw/EAGAIN EINTR/;
9
10	=head1 NAME	1	=head1 NAME
11		2
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut
19
20	our $VERSION = '0.01';
21		4
22	=head1 SYNOPSIS	5	=head1 SYNOPSIS
23		6
24	use AnyEvent;	7	use AnyEvent;
25	use AnyEvent::Handle;	8	use AnyEvent::Handle;
26		9
27	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
28		11
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
		13	fh => \*STDIN,
		14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	warn "got error $msg\n";
		17	$hdl->destroy;
		18	$cv->send;
		19	};
30		20
31	$ae_fh->on_eof (sub { $cv->broadcast });	21	# send some request line
		22	$hdl->push_write ("getinfo\015\012");
32		23
33	$ae_fh->readlines (sub {	24	# read the response line
		25	$hdl->push_read (line => sub {
34	my ($ae_fh, @lines) = @_;	26	my ($hdl, $line) = @_;
35	for (@lines) {	27	warn "got line <$line>\n";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
		32
		33	=head1 DESCRIPTION
		34
		35	This module is a helper module to make it easier to do event-based I/O on
		36	filehandles.
		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
		41	In the following, when the documentation refers to of "bytes" then this
		42	means characters. As sysread and syswrite are used for all I/O, their
		43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
		48	All callbacks will be invoked with the handle object as their first
		49	argument.
		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		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	=head1 METHODS
		81
		82	=over 4
		83
		84	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
		85
		86	The constructor supports these arguments (all as C<< key => value >> pairs).
		87
		88	=over 4
		89
		90	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		91
		92	The filehandle this L<AnyEvent::Handle> object will operate on.
		93	NOTE: The filehandle will be set to non-blocking mode (using
		94	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		95	that mode.
		96
		97	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		98
		99	Try to connect to the specified host and service (port), using
		100	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		101	default C<peername>.
		102
		103	You have to specify either this parameter, or C<fh>, above.
		104
		105	It is possible to push requests on the read and write queues, and modify
		106	properties of the stream, even while AnyEvent::Handle is connecting.
		107
		108	When this parameter is specified, then the C<on_prepare>,
		109	C<on_connect_error> and C<on_connect> callbacks will be called under the
		110	appropriate circumstances:
		111
		112	=over 4
		113
		114	=item on_prepare => $cb->($handle)
		115
		116	This (rarely used) callback is called before a new connection is
		117	attempted, but after the file handle has been created. It could be used to
		118	prepare the file handle with parameters required for the actual connect
		119	(as opposed to settings that can be changed when the connection is already
		120	established).
		121
		122	The return value of this callback should be the connect timeout value in
		123	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		124	timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The actual numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	When, for some reason, the handle is not acceptable, then calling
		134	C<$retry> will continue with the next connection target (in case of
		135	multi-homed hosts or SRV records there can be multiple connection
		136	endpoints). At the time it is called the read and write queues, eof
		137	status, tls status and similar properties of the handle will have been
		138	reset.
		139
		140	In most cases, ignoring the C<$retry> parameter is the way to go.
		141
		142	=item on_connect_error => $cb->($handle, $message)
		143
		144	This callback is called when the connection could not be
		145	established. C<$!> will contain the relevant error code, and C<$message> a
		146	message describing it (usually the same as C<"$!">).
		147
		148	If this callback isn't specified, then C<on_error> will be called with a
		149	fatal error instead.
		150
		151	=back
		152
		153	=item on_error => $cb->($handle, $fatal, $message)
		154
		155	This is the error callback, which is called when, well, some error
		156	occured, such as not being able to resolve the hostname, failure to
		157	connect or a read error.
		158
		159	Some errors are fatal (which is indicated by C<$fatal> being true). On
		160	fatal errors the handle object will be destroyed (by a call to C<< ->
		161	destroy >>) after invoking the error callback (which means you are free to
		162	examine the handle object). Examples of fatal errors are an EOF condition
		163	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		164	cases where the other side can close the connection at their will it is
		165	often easiest to not report C<EPIPE> errors in this callback.
		166
		167	AnyEvent::Handle tries to find an appropriate error code for you to check
		168	against, but in some cases (TLS errors), this does not work well. It is
		169	recommended to always output the C<$message> argument in human-readable
		170	error messages (it's usually the same as C<"$!">).
		171
		172	Non-fatal errors can be retried by simply returning, but it is recommended
		173	to simply ignore this parameter and instead abondon the handle object
		174	when this callback is invoked. Examples of non-fatal errors are timeouts
		175	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		176
		177	On callback entrance, the value of C<$!> contains the operating system
		178	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		179	C<EPROTO>).
		180
		181	While not mandatory, it is I<highly> recommended to set this callback, as
		182	you will not be notified of errors otherwise. The default simply calls
		183	C<croak>.
		184
		185	=item on_read => $cb->($handle)
		186
		187	This sets the default read callback, which is called when data arrives
		188	and no read request is in the queue (unlike read queue callbacks, this
		189	callback will only be called when at least one octet of data is in the
		190	read buffer).
		191
		192	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		193	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		194	must not enlarge or modify the read buffer, you can only remove data at
		195	the beginning from it.
		196
		197	When an EOF condition is detected then AnyEvent::Handle will first try to
		198	feed all the remaining data to the queued callbacks and C<on_read> before
		199	calling the C<on_eof> callback. If no progress can be made, then a fatal
		200	error will be raised (with C<$!> set to C<EPIPE>).
		201
		202	Note that, unlike requests in the read queue, an C<on_read> callback
		203	doesn't mean you I<require> some data: if there is an EOF and there
		204	are outstanding read requests then an error will be flagged. With an
		205	C<on_read> callback, the C<on_eof> callback will be invoked.
		206
		207	=item on_eof => $cb->($handle)
		208
		209	Set the callback to be called when an end-of-file condition is detected,
		210	i.e. in the case of a socket, when the other side has closed the
		211	connection cleanly, and there are no outstanding read requests in the
		212	queue (if there are read requests, then an EOF counts as an unexpected
		213	connection close and will be flagged as an error).
		214
		215	For sockets, this just means that the other side has stopped sending data,
		216	you can still try to write data, and, in fact, one can return from the EOF
		217	callback and continue writing data, as only the read part has been shut
		218	down.
		219
		220	If an EOF condition has been detected but no C<on_eof> callback has been
		221	set, then a fatal error will be raised with C<$!> set to <0>.
		222
		223	=item on_drain => $cb->($handle)
		224
		225	This sets the callback that is called when the write buffer becomes empty
		226	(or when the callback is set and the buffer is empty already).
		227
		228	To append to the write buffer, use the C<< ->push_write >> method.
		229
		230	This callback is useful when you don't want to put all of your write data
		231	into the queue at once, for example, when you want to write the contents
		232	of some file to the socket you might not want to read the whole file into
		233	memory and push it into the queue, but instead only read more data from
		234	the file when the write queue becomes empty.
		235
		236	=item timeout => $fractional_seconds
		237
		238	=item rtimeout => $fractional_seconds
		239
		240	=item wtimeout => $fractional_seconds
		241
		242	If non-zero, then these enables an "inactivity" timeout: whenever this
		243	many seconds pass without a successful read or write on the underlying
		244	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		245	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		246	error will be raised).
		247
		248	There are three variants of the timeouts that work fully independent
		249	of each other, for both read and write, just read, and just write:
		250	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		251	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		252	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		253
		254	Note that timeout processing is also active when you currently do not have
		255	any outstanding read or write requests: If you plan to keep the connection
		256	idle then you should disable the timout temporarily or ignore the timeout
		257	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		258	restart the timeout.
		259
		260	Zero (the default) disables this timeout.
		261
		262	=item on_timeout => $cb->($handle)
		263
		264	Called whenever the inactivity timeout passes. If you return from this
		265	callback, then the timeout will be reset as if some activity had happened,
		266	so this condition is not fatal in any way.
		267
		268	=item rbuf_max => <bytes>
		269
		270	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		271	when the read buffer ever (strictly) exceeds this size. This is useful to
		272	avoid some forms of denial-of-service attacks.
		273
		274	For example, a server accepting connections from untrusted sources should
		275	be configured to accept only so-and-so much data that it cannot act on
		276	(for example, when expecting a line, an attacker could send an unlimited
		277	amount of data without a callback ever being called as long as the line
		278	isn't finished).
		279
		280	=item autocork => <boolean>
		281
		282	When disabled (the default), then C<push_write> will try to immediately
		283	write the data to the handle, if possible. This avoids having to register
		284	a write watcher and wait for the next event loop iteration, but can
		285	be inefficient if you write multiple small chunks (on the wire, this
		286	disadvantage is usually avoided by your kernel's nagle algorithm, see
		287	C<no_delay>, but this option can save costly syscalls).
		288
		289	When enabled, then writes will always be queued till the next event loop
		290	iteration. This is efficient when you do many small writes per iteration,
		291	but less efficient when you do a single write only per iteration (or when
		292	the write buffer often is full). It also increases write latency.
		293
		294	=item no_delay => <boolean>
		295
		296	When doing small writes on sockets, your operating system kernel might
		297	wait a bit for more data before actually sending it out. This is called
		298	the Nagle algorithm, and usually it is beneficial.
		299
		300	In some situations you want as low a delay as possible, which can be
		301	accomplishd by setting this option to a true value.
		302
		303	The default is your opertaing system's default behaviour (most likely
		304	enabled), this option explicitly enables or disables it, if possible.
		305
		306	=item keepalive => <boolean>
		307
		308	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		309	normally, TCP connections have no time-out once established, so TCP
		310	connections, once established, can stay alive forever even when the other
		311	side has long gone. TCP keepalives are a cheap way to take down long-lived
		312	TCP connections whent he other side becomes unreachable. While the default
		313	is OS-dependent, TCP keepalives usually kick in after around two hours,
		314	and, if the other side doesn't reply, take down the TCP connection some 10
		315	to 15 minutes later.
		316
		317	It is harmless to specify this option for file handles that do not support
		318	keepalives, and enabling it on connections that are potentially long-lived
		319	is usually a good idea.
		320
		321	=item oobinline => <boolean>
		322
		323	BSD majorly fucked up the implementation of TCP urgent data. The result
		324	is that almost no OS implements TCP according to the specs, and every OS
		325	implements it slightly differently.
		326
		327	If you want to handle TCP urgent data, then setting this flag (the default
		328	is enabled) gives you the most portable way of getting urgent data, by
		329	putting it into the stream.
		330
		331	Since BSD emulation of OOB data on top of TCP's urgent data can have
		332	security implications, AnyEvent::Handle sets this flag automatically
		333	unless explicitly specified. Note that setting this flag after
		334	establishing a connection I<may> be a bit too late (data loss could
		335	already have occured on BSD systems), but at least it will protect you
		336	from most attacks.
		337
		338	=item read_size => <bytes>
		339
		340	The default read block size (the amount of bytes this module will
		341	try to read during each loop iteration, which affects memory
		342	requirements). Default: C<8192>.
		343
		344	=item low_water_mark => <bytes>
		345
		346	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		347	buffer: If the write reaches this size or gets even samller it is
		348	considered empty.
		349
		350	Sometimes it can be beneficial (for performance reasons) to add data to
		351	the write buffer before it is fully drained, but this is a rare case, as
		352	the operating system kernel usually buffers data as well, so the default
		353	is good in almost all cases.
		354
		355	=item linger => <seconds>
		356
		357	If non-zero (default: C<3600>), then the destructor of the
		358	AnyEvent::Handle object will check whether there is still outstanding
		359	write data and will install a watcher that will write this data to the
		360	socket. No errors will be reported (this mostly matches how the operating
		361	system treats outstanding data at socket close time).
		362
		363	This will not work for partial TLS data that could not be encoded
		364	yet. This data will be lost. Calling the C<stoptls> method in time might
		365	help.
		366
		367	=item peername => $string
		368
		369	A string used to identify the remote site - usually the DNS hostname
		370	(I<not> IDN!) used to create the connection, rarely the IP address.
		371
		372	Apart from being useful in error messages, this string is also used in TLS
		373	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		374	verification will be skipped when C<peername> is not specified or
		375	C<undef>.
		376
		377	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		378
		379	When this parameter is given, it enables TLS (SSL) mode, that means
		380	AnyEvent will start a TLS handshake as soon as the connection has been
		381	established and will transparently encrypt/decrypt data afterwards.
		382
		383	All TLS protocol errors will be signalled as C<EPROTO>, with an
		384	appropriate error message.
		385
		386	TLS mode requires Net::SSLeay to be installed (it will be loaded
		387	automatically when you try to create a TLS handle): this module doesn't
		388	have a dependency on that module, so if your module requires it, you have
		389	to add the dependency yourself.
		390
		391	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		392	C<accept>, and for the TLS client side of a connection, use C<connect>
		393	mode.
		394
		395	You can also provide your own TLS connection object, but you have
		396	to make sure that you call either C<Net::SSLeay::set_connect_state>
		397	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		398	AnyEvent::Handle. Also, this module will take ownership of this connection
		399	object.
		400
		401	At some future point, AnyEvent::Handle might switch to another TLS
		402	implementation, then the option to use your own session object will go
		403	away.
		404
		405	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		406	passing in the wrong integer will lead to certain crash. This most often
		407	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		408	segmentation fault.
		409
		410	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		411
		412	=item tls_ctx => $anyevent_tls
		413
		414	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		415	(unless a connection object was specified directly). If this parameter is
		416	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		417
		418	Instead of an object, you can also specify a hash reference with C<< key
		419	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		420	new TLS context object.
		421
		422	=item on_starttls => $cb->($handle, $success[, $error_message])
		423
		424	This callback will be invoked when the TLS/SSL handshake has finished. If
		425	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		426	(C<on_stoptls> will not be called in this case).
		427
		428	The session in C<< $handle->{tls} >> can still be examined in this
		429	callback, even when the handshake was not successful.
		430
		431	TLS handshake failures will not cause C<on_error> to be invoked when this
		432	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		433
		434	Without this callback, handshake failures lead to C<on_error> being
		435	called, as normal.
		436
		437	Note that you cannot call C<starttls> right again in this callback. If you
		438	need to do that, start an zero-second timer instead whose callback can
		439	then call C<< ->starttls >> again.
		440
		441	=item on_stoptls => $cb->($handle)
		442
		443	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		444	set, then it will be invoked after freeing the TLS session. If it is not,
		445	then a TLS shutdown condition will be treated like a normal EOF condition
		446	on the handle.
		447
		448	The session in C<< $handle->{tls} >> can still be examined in this
		449	callback.
		450
		451	This callback will only be called on TLS shutdowns, not when the
		452	underlying handle signals EOF.
		453
		454	=item json => JSON or JSON::XS object
		455
		456	This is the json coder object used by the C<json> read and write types.
		457
		458	If you don't supply it, then AnyEvent::Handle will create and use a
		459	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		460	texts.
		461
		462	Note that you are responsible to depend on the JSON module if you want to
		463	use this functionality, as AnyEvent does not have a dependency itself.
		464
		465	=back
		466
		467	=cut
		468
		469	sub new {
		470	my $class = shift;
		471	my $self = bless { @_ }, $class;
		472
		473	if ($self->{fh}) {
		474	$self->_start;
		475	return unless $self->{fh}; # could be gone by now
		476
		477	} elsif ($self->{connect}) {
		478	require AnyEvent::Socket;
		479
		480	$self->{peername} = $self->{connect}[0]
		481	unless exists $self->{peername};
		482
		483	$self->{_skip_drain_rbuf} = 1;
		484
		485	{
		486	Scalar::Util::weaken (my $self = $self);
		487
		488	$self->{_connect} =
		489	AnyEvent::Socket::tcp_connect (
		490	$self->{connect}[0],
		491	$self->{connect}[1],
		492	sub {
		493	my ($fh, $host, $port, $retry) = @_;
		494
		495	if ($fh) {
		496	$self->{fh} = $fh;
		497
		498	delete $self->{_skip_drain_rbuf};
		499	$self->_start;
		500
		501	$self->{on_connect}
		502	and $self->{on_connect}($self, $host, $port, sub {
		503	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		504	$self->{_skip_drain_rbuf} = 1;
		505	&$retry;
		506	});
		507
		508	} else {
		509	if ($self->{on_connect_error}) {
		510	$self->{on_connect_error}($self, "$!");
		511	$self->destroy;
		512	} else {
		513	$self->_error ($!, 1);
		514	}
		515	}
		516	},
		517	sub {
		518	local $self->{fh} = $_[0];
		519
		520	$self->{on_prepare}
		521	? $self->{on_prepare}->($self)
		522	: ()
		523	}
		524	);
		525	}
		526
		527	} else {
		528	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		529	}
		530
		531	$self
		532	}
		533
		534	sub _start {
		535	my ($self) = @_;
		536
		537	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		538
		539	$self->{_activity} =
		540	$self->{_ractivity} =
		541	$self->{_wactivity} = AE::now;
		542
		543	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		544	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		545	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		546
		547	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		548	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		549
		550	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		551
		552	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		553	if $self->{tls};
		554
		555	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		556
		557	$self->start_read
		558	if $self->{on_read} || @{ $self->{_queue} };
		559
		560	$self->_drain_wbuf;
		561	}
		562
		563	sub _error {
		564	my ($self, $errno, $fatal, $message) = @_;
		565
		566	$! = $errno;
		567	$message ||= "$!";
		568
		569	if ($self->{on_error}) {
		570	$self->{on_error}($self, $fatal, $message);
		571	$self->destroy if $fatal;
		572	} elsif ($self->{fh} || $self->{connect}) {
		573	$self->destroy;
		574	Carp::croak "AnyEvent::Handle uncaught error: $message";
		575	}
		576	}
		577
		578	=item $fh = $handle->fh
		579
		580	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		581
		582	=cut
		583
		584	sub fh { $_[0]{fh} }
		585
		586	=item $handle->on_error ($cb)
		587
		588	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		589
		590	=cut
		591
		592	sub on_error {
		593	$_[0]{on_error} = $_[1];
		594	}
		595
		596	=item $handle->on_eof ($cb)
		597
		598	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		599
		600	=cut
		601
		602	sub on_eof {
		603	$_[0]{on_eof} = $_[1];
		604	}
		605
		606	=item $handle->on_timeout ($cb)
		607
		608	=item $handle->on_rtimeout ($cb)
		609
		610	=item $handle->on_wtimeout ($cb)
		611
		612	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		613	callback, or disables the callback (but not the timeout) if C<$cb> =
		614	C<undef>. See the C<timeout> constructor argument and method.
		615
		616	=cut
		617
		618	# see below
		619
		620	=item $handle->autocork ($boolean)
		621
		622	Enables or disables the current autocork behaviour (see C<autocork>
		623	constructor argument). Changes will only take effect on the next write.
		624
		625	=cut
		626
		627	sub autocork {
		628	$_[0]{autocork} = $_[1];
		629	}
		630
		631	=item $handle->no_delay ($boolean)
		632
		633	Enables or disables the C<no_delay> setting (see constructor argument of
		634	the same name for details).
		635
		636	=cut
		637
		638	sub no_delay {
		639	$_[0]{no_delay} = $_[1];
		640
		641	eval {
		642	local $SIG{__DIE__};
		643	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		644	if $_[0]{fh};
		645	};
		646	}
		647
		648	=item $handle->keepalive ($boolean)
		649
		650	Enables or disables the C<keepalive> setting (see constructor argument of
		651	the same name for details).
		652
		653	=cut
		654
		655	sub keepalive {
		656	$_[0]{keepalive} = $_[1];
		657
		658	eval {
		659	local $SIG{__DIE__};
		660	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		661	if $_[0]{fh};
		662	};
		663	}
		664
		665	=item $handle->oobinline ($boolean)
		666
		667	Enables or disables the C<oobinline> setting (see constructor argument of
		668	the same name for details).
		669
		670	=cut
		671
		672	sub oobinline {
		673	$_[0]{oobinline} = $_[1];
		674
		675	eval {
		676	local $SIG{__DIE__};
		677	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		678	if $_[0]{fh};
		679	};
		680	}
		681
		682	=item $handle->keepalive ($boolean)
		683
		684	Enables or disables the C<keepalive> setting (see constructor argument of
		685	the same name for details).
		686
		687	=cut
		688
		689	sub keepalive {
		690	$_[0]{keepalive} = $_[1];
		691
		692	eval {
		693	local $SIG{__DIE__};
		694	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		695	if $_[0]{fh};
		696	};
		697	}
		698
		699	=item $handle->on_starttls ($cb)
		700
		701	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		702
		703	=cut
		704
		705	sub on_starttls {
		706	$_[0]{on_starttls} = $_[1];
		707	}
		708
		709	=item $handle->on_stoptls ($cb)
		710
		711	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		712
		713	=cut
		714
		715	sub on_stoptls {
		716	$_[0]{on_stoptls} = $_[1];
		717	}
		718
		719	=item $handle->rbuf_max ($max_octets)
		720
		721	Configures the C<rbuf_max> setting (C<undef> disables it).
		722
		723	=cut
		724
		725	sub rbuf_max {
		726	$_[0]{rbuf_max} = $_[1];
		727	}
		728
		729	#############################################################################
		730
		731	=item $handle->timeout ($seconds)
		732
		733	=item $handle->rtimeout ($seconds)
		734
		735	=item $handle->wtimeout ($seconds)
		736
		737	Configures (or disables) the inactivity timeout.
		738
		739	=item $handle->timeout_reset
		740
		741	=item $handle->rtimeout_reset
		742
		743	=item $handle->wtimeout_reset
		744
		745	Reset the activity timeout, as if data was received or sent.
		746
		747	These methods are cheap to call.
		748
		749	=cut
		750
		751	for my $dir ("", "r", "w") {
		752	my $timeout = "${dir}timeout";
		753	my $tw = "_${dir}tw";
		754	my $on_timeout = "on_${dir}timeout";
		755	my $activity = "_${dir}activity";
		756	my $cb;
		757
		758	*$on_timeout = sub {
		759	$_[0]{$on_timeout} = $_[1];
		760	};
		761
		762	*$timeout = sub {
		763	my ($self, $new_value) = @_;
		764
		765	$self->{$timeout} = $new_value;
		766	delete $self->{$tw}; &$cb;
		767	};
		768
		769	*{"${dir}timeout_reset"} = sub {
		770	$_[0]{$activity} = AE::now;
		771	};
		772
		773	# main workhorse:
		774	# reset the timeout watcher, as neccessary
		775	# also check for time-outs
		776	$cb = sub {
		777	my ($self) = @_;
		778
		779	if ($self->{$timeout} && $self->{fh}) {
		780	my $NOW = AE::now;
		781
		782	# when would the timeout trigger?
		783	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		784
		785	# now or in the past already?
		786	if ($after <= 0) {
		787	$self->{$activity} = $NOW;
		788
		789	if ($self->{$on_timeout}) {
		790	$self->{$on_timeout}($self);
		791	} else {
		792	$self->_error (Errno::ETIMEDOUT);
		793	}
		794
		795	# callback could have changed timeout value, optimise
		796	return unless $self->{$timeout};
		797
		798	# calculate new after
		799	$after = $self->{$timeout};
		800	}
		801
		802	Scalar::Util::weaken $self;
		803	return unless $self; # ->error could have destroyed $self
		804
		805	$self->{$tw} ||= AE::timer $after, 0, sub {
		806	delete $self->{$tw};
		807	$cb->($self);
36	chomp;	808	};
37	print "Line: $_";	809	} else {
		810	delete $self->{$tw};
		811	}
		812	}
		813	}
		814
		815	#############################################################################
		816
		817	=back
		818
		819	=head2 WRITE QUEUE
		820
		821	AnyEvent::Handle manages two queues per handle, one for writing and one
		822	for reading.
		823
		824	The write queue is very simple: you can add data to its end, and
		825	AnyEvent::Handle will automatically try to get rid of it for you.
		826
		827	When data could be written and the write buffer is shorter then the low
		828	water mark, the C<on_drain> callback will be invoked.
		829
		830	=over 4
		831
		832	=item $handle->on_drain ($cb)
		833
		834	Sets the C<on_drain> callback or clears it (see the description of
		835	C<on_drain> in the constructor).
		836
		837	=cut
		838
		839	sub on_drain {
		840	my ($self, $cb) = @_;
		841
		842	$self->{on_drain} = $cb;
		843
		844	$cb->($self)
		845	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		846	}
		847
		848	=item $handle->push_write ($data)
		849
		850	Queues the given scalar to be written. You can push as much data as you
		851	want (only limited by the available memory), as C<AnyEvent::Handle>
		852	buffers it independently of the kernel.
		853
		854	=cut
		855
		856	sub _drain_wbuf {
		857	my ($self) = @_;
		858
		859	if (!$self->{_ww} && length $self->{wbuf}) {
		860
		861	Scalar::Util::weaken $self;
		862
		863	my $cb = sub {
		864	my $len = syswrite $self->{fh}, $self->{wbuf};
		865
		866	if (defined $len) {
		867	substr $self->{wbuf}, 0, $len, "";
		868
		869	$self->{_activity} = $self->{_wactivity} = AE::now;
		870
		871	$self->{on_drain}($self)
		872	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		873	&& $self->{on_drain};
		874
		875	delete $self->{_ww} unless length $self->{wbuf};
		876	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		877	$self->_error ($!, 1);
		878	}
		879	};
		880
		881	# try to write data immediately
		882	$cb->() unless $self->{autocork};
		883
		884	# if still data left in wbuf, we need to poll
		885	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		886	if length $self->{wbuf};
		887	};
		888	}
		889
		890	our %WH;
		891
		892	# deprecated
		893	sub register_write_type($$) {
		894	$WH{$_[0]} = $_[1];
		895	}
		896
		897	sub push_write {
		898	my $self = shift;
		899
		900	if (@_ > 1) {
		901	my $type = shift;
		902
		903	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		904	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		905	->($self, @_);
		906	}
		907
		908	# we downgrade here to avoid hard-to-track-down bugs,
		909	# and diagnose the problem earlier and better.
		910
		911	if ($self->{tls}) {
		912	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		913	&_dotls ($self) if $self->{fh};
		914	} else {
		915	utf8::downgrade $self->{wbuf} .= $_[0];
		916	$self->_drain_wbuf if $self->{fh};
		917	}
		918	}
		919
		920	=item $handle->push_write (type => @args)
		921
		922	Instead of formatting your data yourself, you can also let this module
		923	do the job by specifying a type and type-specific arguments. You
		924	can also specify the (fully qualified) name of a package, in which
		925	case AnyEvent tries to load the package and then expects to find the
		926	C<anyevent_read_type> function inside (see "custom write types", below).
		927
		928	Predefined types are (if you have ideas for additional types, feel free to
		929	drop by and tell us):
		930
		931	=over 4
		932
		933	=item netstring => $string
		934
		935	Formats the given value as netstring
		936	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		937
		938	=cut
		939
		940	register_write_type netstring => sub {
		941	my ($self, $string) = @_;
		942
		943	(length $string) . ":$string,"
		944	};
		945
		946	=item packstring => $format, $data
		947
		948	An octet string prefixed with an encoded length. The encoding C<$format>
		949	uses the same format as a Perl C<pack> format, but must specify a single
		950	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		951	optional C<!>, C<< < >> or C<< > >> modifier).
		952
		953	=cut
		954
		955	register_write_type packstring => sub {
		956	my ($self, $format, $string) = @_;
		957
		958	pack "$format/a*", $string
		959	};
		960
		961	=item json => $array_or_hashref
		962
		963	Encodes the given hash or array reference into a JSON object. Unless you
		964	provide your own JSON object, this means it will be encoded to JSON text
		965	in UTF-8.
		966
		967	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		968	one end of a handle and read them at the other end without using any
		969	additional framing.
		970
		971	The generated JSON text is guaranteed not to contain any newlines: While
		972	this module doesn't need delimiters after or between JSON texts to be
		973	able to read them, many other languages depend on that.
		974
		975	A simple RPC protocol that interoperates easily with others is to send
		976	JSON arrays (or objects, although arrays are usually the better choice as
		977	they mimic how function argument passing works) and a newline after each
		978	JSON text:
		979
		980	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		981	$handle->push_write ("\012");
		982
		983	An AnyEvent::Handle receiver would simply use the C<json> read type and
		984	rely on the fact that the newline will be skipped as leading whitespace:
		985
		986	$handle->push_read (json => sub { my $array = $_[1]; ... });
		987
		988	Other languages could read single lines terminated by a newline and pass
		989	this line into their JSON decoder of choice.
		990
		991	=cut
		992
		993	sub json_coder() {
		994	eval { require JSON::XS; JSON::XS->new->utf8 }
		995	|| do { require JSON; JSON->new->utf8 }
		996	}
		997
		998	register_write_type json => sub {
		999	my ($self, $ref) = @_;
		1000
		1001	my $json = $self->{json} ||= json_coder;
		1002
		1003	$json->encode ($ref)
		1004	};
		1005
		1006	=item storable => $reference
		1007
		1008	Freezes the given reference using L<Storable> and writes it to the
		1009	handle. Uses the C<nfreeze> format.
		1010
		1011	=cut
		1012
		1013	register_write_type storable => sub {
		1014	my ($self, $ref) = @_;
		1015
		1016	require Storable;
		1017
		1018	pack "w/a*", Storable::nfreeze ($ref)
		1019	};
		1020
		1021	=back
		1022
		1023	=item $handle->push_shutdown
		1024
		1025	Sometimes you know you want to close the socket after writing your data
		1026	before it was actually written. One way to do that is to replace your
		1027	C<on_drain> handler by a callback that shuts down the socket (and set
		1028	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1029	replaces the C<on_drain> callback with:
		1030
		1031	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1032
		1033	This simply shuts down the write side and signals an EOF condition to the
		1034	the peer.
		1035
		1036	You can rely on the normal read queue and C<on_eof> handling
		1037	afterwards. This is the cleanest way to close a connection.
		1038
		1039	=cut
		1040
		1041	sub push_shutdown {
		1042	my ($self) = @_;
		1043
		1044	delete $self->{low_water_mark};
		1045	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1046	}
		1047
		1048	=item custom write types - Package::anyevent_write_type $handle, @args
		1049
		1050	Instead of one of the predefined types, you can also specify the name of
		1051	a package. AnyEvent will try to load the package and then expects to find
		1052	a function named C<anyevent_write_type> inside. If it isn't found, it
		1053	progressively tries to load the parent package until it either finds the
		1054	function (good) or runs out of packages (bad).
		1055
		1056	Whenever the given C<type> is used, C<push_write> will the function with
		1057	the handle object and the remaining arguments.
		1058
		1059	The function is supposed to return a single octet string that will be
		1060	appended to the write buffer, so you cna mentally treat this function as a
		1061	"arguments to on-the-wire-format" converter.
		1062
		1063	Example: implement a custom write type C<join> that joins the remaining
		1064	arguments using the first one.
		1065
		1066	$handle->push_write (My::Type => " ", 1,2,3);
		1067
		1068	# uses the following package, which can be defined in the "My::Type" or in
		1069	# the "My" modules to be auto-loaded, or just about anywhere when the
		1070	# My::Type::anyevent_write_type is defined before invoking it.
		1071
		1072	package My::Type;
		1073
		1074	sub anyevent_write_type {
		1075	my ($handle, $delim, @args) = @_;
		1076
		1077	join $delim, @args
		1078	}
		1079
		1080	=cut
		1081
		1082	#############################################################################
		1083
		1084	=back
		1085
		1086	=head2 READ QUEUE
		1087
		1088	AnyEvent::Handle manages two queues per handle, one for writing and one
		1089	for reading.
		1090
		1091	The read queue is more complex than the write queue. It can be used in two
		1092	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1093	a queue.
		1094
		1095	In the simple case, you just install an C<on_read> callback and whenever
		1096	new data arrives, it will be called. You can then remove some data (if
		1097	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		1098	leave the data there if you want to accumulate more (e.g. when only a
		1099	partial message has been received so far).
		1100
		1101	In the more complex case, you want to queue multiple callbacks. In this
		1102	case, AnyEvent::Handle will call the first queued callback each time new
		1103	data arrives (also the first time it is queued) and removes it when it has
		1104	done its job (see C<push_read>, below).
		1105
		1106	This way you can, for example, push three line-reads, followed by reading
		1107	a chunk of data, and AnyEvent::Handle will execute them in order.
		1108
		1109	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1110	the specified number of bytes which give an XML datagram.
		1111
		1112	# in the default state, expect some header bytes
		1113	$handle->on_read (sub {
		1114	# some data is here, now queue the length-header-read (4 octets)
		1115	shift->unshift_read (chunk => 4, sub {
		1116	# header arrived, decode
		1117	my $len = unpack "N", $_[1];
		1118
		1119	# now read the payload
		1120	shift->unshift_read (chunk => $len, sub {
		1121	my $xml = $_[1];
		1122	# handle xml
		1123	});
		1124	});
		1125	});
		1126
		1127	Example 2: Implement a client for a protocol that replies either with "OK"
		1128	and another line or "ERROR" for the first request that is sent, and 64
		1129	bytes for the second request. Due to the availability of a queue, we can
		1130	just pipeline sending both requests and manipulate the queue as necessary
		1131	in the callbacks.
		1132
		1133	When the first callback is called and sees an "OK" response, it will
		1134	C<unshift> another line-read. This line-read will be queued I<before> the
		1135	64-byte chunk callback.
		1136
		1137	# request one, returns either "OK + extra line" or "ERROR"
		1138	$handle->push_write ("request 1\015\012");
		1139
		1140	# we expect "ERROR" or "OK" as response, so push a line read
		1141	$handle->push_read (line => sub {
		1142	# if we got an "OK", we have to _prepend_ another line,
		1143	# so it will be read before the second request reads its 64 bytes
		1144	# which are already in the queue when this callback is called
		1145	# we don't do this in case we got an error
		1146	if ($_[1] eq "OK") {
		1147	$_[0]->unshift_read (line => sub {
		1148	my $response = $_[1];
		1149	...
		1150	});
38	}	1151	}
39	});	1152	});
40		1153
41	# or use the constructor to pass the callback:	1154	# request two, simply returns 64 octets
		1155	$handle->push_write ("request 2\015\012");
42		1156
43	my $ae_fh2 =	1157	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1158	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1159	my $response = $_[1];
46	on_eof => sub {	1160	...
47	$cv->broadcast;	1161	});
48	},	1162
49	on_readline => sub {	1163	=over 4
50	my ($ae_fh, @lines) = @_;	1164
51	for (@lines) {	1165	=cut
52	chomp;	1166
53	print "Line: $_";	1167	sub _drain_rbuf {
		1168	my ($self) = @_;
		1169
		1170	# avoid recursion
		1171	return if $self->{_skip_drain_rbuf};
		1172	local $self->{_skip_drain_rbuf} = 1;
		1173
		1174	while () {
		1175	# we need to use a separate tls read buffer, as we must not receive data while
		1176	# we are draining the buffer, and this can only happen with TLS.
		1177	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1178	if exists $self->{_tls_rbuf};
		1179
		1180	my $len = length $self->{rbuf};
		1181
		1182	if (my $cb = shift @{ $self->{_queue} }) {
		1183	unless ($cb->($self)) {
		1184	# no progress can be made
		1185	# (not enough data and no data forthcoming)
		1186	$self->_error (Errno::EPIPE, 1), return
		1187	if $self->{_eof};
		1188
		1189	unshift @{ $self->{_queue} }, $cb;
54	}	1190	last;
55	}	1191	}
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}) {	1192	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1193	last unless $len;
122		1194
		1195	$self->{on_read}($self);
		1196
		1197	if (
		1198	$len == length $self->{rbuf} # if no data has been consumed
		1199	&& !@{ $self->{_queue} } # and the queue is still empty
		1200	&& $self->{on_read} # but we still have on_read
		1201	) {
		1202	# no further data will arrive
		1203	# so no progress can be made
		1204	$self->_error (Errno::EPIPE, 1), return
		1205	if $self->{_eof};
		1206
		1207	last; # more data might arrive
		1208	}
		1209	} else {
		1210	# read side becomes idle
		1211	delete $self->{_rw} unless $self->{tls};
		1212	last;
		1213	}
		1214	}
		1215
123	} elsif ($self->{on_eof}) {	1216	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1217	$self->{on_eof}
		1218	? $self->{on_eof}($self)
		1219	: $self->_error (0, 1, "Unexpected end-of-file");
125		1220
126	} elsif ($self->{on_error}) {	1221	return;
127	$self->on_eof ($self->{on_error});
128	}	1222	}
129		1223
130	return $self	1224	if (
131	}	1225	defined $self->{rbuf_max}
		1226	&& $self->{rbuf_max} < length $self->{rbuf}
		1227	) {
		1228	$self->_error (Errno::ENOSPC, 1), return;
		1229	}
132		1230
133	=item B<fh>	1231	# may need to restart read watcher
		1232	unless ($self->{_rw}) {
		1233	$self->start_read
		1234	if $self->{on_read} || @{ $self->{_queue} };
		1235	}
		1236	}
134		1237
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1238	=item $handle->on_read ($cb)
136		1239
137	=cut	1240	This replaces the currently set C<on_read> callback, or clears it (when
138		1241	the new callback is C<undef>). See the description of C<on_read> in the
139	sub fh { $_[0]->{fh} }	1242	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		1243
149	=cut	1244	=cut
150		1245
151	sub on_read {	1246	sub on_read {
152	my ($self, $cb) = @_;	1247	my ($self, $cb) = @_;
		1248
153	$self->{on_read} = $cb;	1249	$self->{on_read} = $cb;
		1250	$self->_drain_rbuf if $cb;
		1251	}
154		1252
155	unless (defined $self->{on_read}) {	1253	=item $handle->rbuf
156	delete $self->{on_read_w};	1254
		1255	Returns the read buffer (as a modifiable lvalue).
		1256
		1257	You can access the read buffer directly as the C<< ->{rbuf} >>
		1258	member, if you want. However, the only operation allowed on the
		1259	read buffer (apart from looking at it) is removing data from its
		1260	beginning. Otherwise modifying or appending to it is not allowed and will
		1261	lead to hard-to-track-down bugs.
		1262
		1263	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1264	C<push_read> or C<unshift_read> methods are used. The other read methods
		1265	automatically manage the read buffer.
		1266
		1267	=cut
		1268
		1269	sub rbuf : lvalue {
		1270	$_[0]{rbuf}
		1271	}
		1272
		1273	=item $handle->push_read ($cb)
		1274
		1275	=item $handle->unshift_read ($cb)
		1276
		1277	Append the given callback to the end of the queue (C<push_read>) or
		1278	prepend it (C<unshift_read>).
		1279
		1280	The callback is called each time some additional read data arrives.
		1281
		1282	It must check whether enough data is in the read buffer already.
		1283
		1284	If not enough data is available, it must return the empty list or a false
		1285	value, in which case it will be called repeatedly until enough data is
		1286	available (or an error condition is detected).
		1287
		1288	If enough data was available, then the callback must remove all data it is
		1289	interested in (which can be none at all) and return a true value. After returning
		1290	true, it will be removed from the queue.
		1291
		1292	=cut
		1293
		1294	our %RH;
		1295
		1296	sub register_read_type($$) {
		1297	$RH{$_[0]} = $_[1];
		1298	}
		1299
		1300	sub push_read {
		1301	my $self = shift;
		1302	my $cb = pop;
		1303
		1304	if (@_) {
		1305	my $type = shift;
		1306
		1307	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1308	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1309	->($self, $cb, @_);
		1310	}
		1311
		1312	push @{ $self->{_queue} }, $cb;
		1313	$self->_drain_rbuf;
		1314	}
		1315
		1316	sub unshift_read {
		1317	my $self = shift;
		1318	my $cb = pop;
		1319
		1320	if (@_) {
		1321	my $type = shift;
		1322
		1323	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1324	->($self, $cb, @_);
		1325	}
		1326
		1327	unshift @{ $self->{_queue} }, $cb;
		1328	$self->_drain_rbuf;
		1329	}
		1330
		1331	=item $handle->push_read (type => @args, $cb)
		1332
		1333	=item $handle->unshift_read (type => @args, $cb)
		1334
		1335	Instead of providing a callback that parses the data itself you can chose
		1336	between a number of predefined parsing formats, for chunks of data, lines
		1337	etc. You can also specify the (fully qualified) name of a package, in
		1338	which case AnyEvent tries to load the package and then expects to find the
		1339	C<anyevent_read_type> function inside (see "custom read types", below).
		1340
		1341	Predefined types are (if you have ideas for additional types, feel free to
		1342	drop by and tell us):
		1343
		1344	=over 4
		1345
		1346	=item chunk => $octets, $cb->($handle, $data)
		1347
		1348	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1349	data read to the callback. The callback will never be called with less
		1350	data.
		1351
		1352	Example: read 2 bytes.
		1353
		1354	$handle->push_read (chunk => 2, sub {
		1355	warn "yay ", unpack "H*", $_[1];
		1356	});
		1357
		1358	=cut
		1359
		1360	register_read_type chunk => sub {
		1361	my ($self, $cb, $len) = @_;
		1362
		1363	sub {
		1364	$len <= length $_[0]{rbuf} or return;
		1365	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1366	1
		1367	}
		1368	};
		1369
		1370	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1371
		1372	The callback will be called only once a full line (including the end of
		1373	line marker, C<$eol>) has been read. This line (excluding the end of line
		1374	marker) will be passed to the callback as second argument (C<$line>), and
		1375	the end of line marker as the third argument (C<$eol>).
		1376
		1377	The end of line marker, C<$eol>, can be either a string, in which case it
		1378	will be interpreted as a fixed record end marker, or it can be a regex
		1379	object (e.g. created by C<qr>), in which case it is interpreted as a
		1380	regular expression.
		1381
		1382	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1383	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1384	protocols).
		1385
		1386	Partial lines at the end of the stream will never be returned, as they are
		1387	not marked by the end of line marker.
		1388
		1389	=cut
		1390
		1391	register_read_type line => sub {
		1392	my ($self, $cb, $eol) = @_;
		1393
		1394	if (@_ < 3) {
		1395	# this is more than twice as fast as the generic code below
		1396	sub {
		1397	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1398
		1399	$cb->($_[0], $1, $2);
		1400	1
		1401	}
		1402	} else {
		1403	$eol = quotemeta $eol unless ref $eol;
		1404	$eol = qr|^(.*?)($eol)|s;
		1405
		1406	sub {
		1407	$_[0]{rbuf} =~ s/$eol// or return;
		1408
		1409	$cb->($_[0], $1, $2);
		1410	1
		1411	}
		1412	}
		1413	};
		1414
		1415	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1416
		1417	Makes a regex match against the regex object C<$accept> and returns
		1418	everything up to and including the match.
		1419
		1420	Example: read a single line terminated by '\n'.
		1421
		1422	$handle->push_read (regex => qr<\n>, sub { ... });
		1423
		1424	If C<$reject> is given and not undef, then it determines when the data is
		1425	to be rejected: it is matched against the data when the C<$accept> regex
		1426	does not match and generates an C<EBADMSG> error when it matches. This is
		1427	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1428	receive buffer overflow).
		1429
		1430	Example: expect a single decimal number followed by whitespace, reject
		1431	anything else (not the use of an anchor).
		1432
		1433	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1434
		1435	If C<$skip> is given and not C<undef>, then it will be matched against
		1436	the receive buffer when neither C<$accept> nor C<$reject> match,
		1437	and everything preceding and including the match will be accepted
		1438	unconditionally. This is useful to skip large amounts of data that you
		1439	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1440	have to start matching from the beginning. This is purely an optimisation
		1441	and is usually worth only when you expect more than a few kilobytes.
		1442
		1443	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1444	expect the header to be very large (it isn't in practise, but...), we use
		1445	a skip regex to skip initial portions. The skip regex is tricky in that
		1446	it only accepts something not ending in either \015 or \012, as these are
		1447	required for the accept regex.
		1448
		1449	$handle->push_read (regex =>
		1450	qr<\015\012\015\012>,
		1451	undef, # no reject
		1452	qr<^.*[^\015\012]>,
		1453	sub { ... });
		1454
		1455	=cut
		1456
		1457	register_read_type regex => sub {
		1458	my ($self, $cb, $accept, $reject, $skip) = @_;
		1459
		1460	my $data;
		1461	my $rbuf = \$self->{rbuf};
		1462
		1463	sub {
		1464	# accept
		1465	if ($$rbuf =~ $accept) {
		1466	$data .= substr $$rbuf, 0, $+[0], "";
		1467	$cb->($self, $data);
		1468	return 1;
		1469	}
		1470
		1471	# reject
		1472	if ($reject && $$rbuf =~ $reject) {
		1473	$self->_error (Errno::EBADMSG);
		1474	}
		1475
		1476	# skip
		1477	if ($skip && $$rbuf =~ $skip) {
		1478	$data .= substr $$rbuf, 0, $+[0], "";
		1479	}
		1480
		1481	()
		1482	}
		1483	};
		1484
		1485	=item netstring => $cb->($handle, $string)
		1486
		1487	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1488
		1489	Throws an error with C<$!> set to EBADMSG on format violations.
		1490
		1491	=cut
		1492
		1493	register_read_type netstring => sub {
		1494	my ($self, $cb) = @_;
		1495
		1496	sub {
		1497	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1498	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1499	$self->_error (Errno::EBADMSG);
		1500	}
157	return;	1501	return;
		1502	}
		1503
		1504	my $len = $1;
		1505
		1506	$self->unshift_read (chunk => $len, sub {
		1507	my $string = $_[1];
		1508	$_[0]->unshift_read (chunk => 1, sub {
		1509	if ($_[1] eq ",") {
		1510	$cb->($_[0], $string);
		1511	} else {
		1512	$self->_error (Errno::EBADMSG);
		1513	}
		1514	});
		1515	});
		1516
		1517	1
		1518	}
		1519	};
		1520
		1521	=item packstring => $format, $cb->($handle, $string)
		1522
		1523	An octet string prefixed with an encoded length. The encoding C<$format>
		1524	uses the same format as a Perl C<pack> format, but must specify a single
		1525	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1526	optional C<!>, C<< < >> or C<< > >> modifier).
		1527
		1528	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1529	EPP uses a prefix of C<N> (4 octtes).
		1530
		1531	Example: read a block of data prefixed by its length in BER-encoded
		1532	format (very efficient).
		1533
		1534	$handle->push_read (packstring => "w", sub {
		1535	my ($handle, $data) = @_;
158	}	1536	});
159		1537
160	$self->{on_read_w} =	1538	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1539
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1540	register_read_type packstring => sub {
		1541	my ($self, $cb, $format) = @_;
		1542
		1543	sub {
		1544	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1545	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1546	or return;
		1547
		1548	$format = length pack $format, $len;
		1549
		1550	# bypass unshift if we already have the remaining chunk
		1551	if ($format + $len <= length $_[0]{rbuf}) {
		1552	my $data = substr $_[0]{rbuf}, $format, $len;
		1553	substr $_[0]{rbuf}, 0, $format + $len, "";
		1554	$cb->($_[0], $data);
		1555	} else {
		1556	# remove prefix
		1557	substr $_[0]{rbuf}, 0, $format, "";
		1558
		1559	# read remaining chunk
		1560	$_[0]->unshift_read (chunk => $len, $cb);
		1561	}
		1562
		1563	1
		1564	}
		1565	};
		1566
		1567	=item json => $cb->($handle, $hash_or_arrayref)
		1568
		1569	Reads a JSON object or array, decodes it and passes it to the
		1570	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1571
		1572	If a C<json> object was passed to the constructor, then that will be used
		1573	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1574
		1575	This read type uses the incremental parser available with JSON version
		1576	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1577	dependency on your own: this module will load the JSON module, but
		1578	AnyEvent does not depend on it itself.
		1579
		1580	Since JSON texts are fully self-delimiting, the C<json> read and write
		1581	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1582	the C<json> write type description, above, for an actual example.
		1583
		1584	=cut
		1585
		1586	register_read_type json => sub {
		1587	my ($self, $cb) = @_;
		1588
		1589	my $json = $self->{json} ||= json_coder;
		1590
		1591	my $data;
163	my $rbuf_len = length $self->{rbuf};	1592	my $rbuf = \$self->{rbuf};
164	my $l;	1593
165	if (defined $self->{read_size}) {	1594	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1595	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1596
		1597	if ($ref) {
		1598	$self->{rbuf} = $json->incr_text;
		1599	$json->incr_text = "";
		1600	$cb->($self, $ref);
		1601
		1602	1
		1603	} elsif ($@) {
		1604	# error case
		1605	$json->incr_skip;
		1606
		1607	$self->{rbuf} = $json->incr_text;
		1608	$json->incr_text = "";
		1609
		1610	$self->_error (Errno::EBADMSG);
		1611
		1612	()
		1613	} else {
		1614	$self->{rbuf} = "";
		1615
		1616	()
		1617	}
		1618	}
		1619	};
		1620
		1621	=item storable => $cb->($handle, $ref)
		1622
		1623	Deserialises a L<Storable> frozen representation as written by the
		1624	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1625	data).
		1626
		1627	Raises C<EBADMSG> error if the data could not be decoded.
		1628
		1629	=cut
		1630
		1631	register_read_type storable => sub {
		1632	my ($self, $cb) = @_;
		1633
		1634	require Storable;
		1635
		1636	sub {
		1637	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1638	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1639	or return;
		1640
		1641	my $format = length pack "w", $len;
		1642
		1643	# bypass unshift if we already have the remaining chunk
		1644	if ($format + $len <= length $_[0]{rbuf}) {
		1645	my $data = substr $_[0]{rbuf}, $format, $len;
		1646	substr $_[0]{rbuf}, 0, $format + $len, "";
		1647	$cb->($_[0], Storable::thaw ($data));
		1648	} else {
		1649	# remove prefix
		1650	substr $_[0]{rbuf}, 0, $format, "";
		1651
		1652	# read remaining chunk
		1653	$_[0]->unshift_read (chunk => $len, sub {
		1654	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1655	$cb->($_[0], $ref);
		1656	} else {
		1657	$self->_error (Errno::EBADMSG);
		1658	}
		1659	});
		1660	}
		1661
		1662	1
		1663	}
		1664	};
		1665
		1666	=back
		1667
		1668	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1669
		1670	Instead of one of the predefined types, you can also specify the name
		1671	of a package. AnyEvent will try to load the package and then expects to
		1672	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1673	progressively tries to load the parent package until it either finds the
		1674	function (good) or runs out of packages (bad).
		1675
		1676	Whenever this type is used, C<push_read> will invoke the function with the
		1677	handle object, the original callback and the remaining arguments.
		1678
		1679	The function is supposed to return a callback (usually a closure) that
		1680	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1681	mentally treat the function as a "configurable read type to read callback"
		1682	converter.
		1683
		1684	It should invoke the original callback when it is done reading (remember
		1685	to pass C<$handle> as first argument as all other callbacks do that,
		1686	although there is no strict requirement on this).
		1687
		1688	For examples, see the source of this module (F<perldoc -m
		1689	AnyEvent::Handle>, search for C<register_read_type>)).
		1690
		1691	=item $handle->stop_read
		1692
		1693	=item $handle->start_read
		1694
		1695	In rare cases you actually do not want to read anything from the
		1696	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1697	any queued callbacks will be executed then. To start reading again, call
		1698	C<start_read>.
		1699
		1700	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1701	you change the C<on_read> callback or push/unshift a read callback, and it
		1702	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1703	there are any read requests in the queue.
		1704
		1705	These methods will have no effect when in TLS mode (as TLS doesn't support
		1706	half-duplex connections).
		1707
		1708	=cut
		1709
		1710	sub stop_read {
		1711	my ($self) = @_;
		1712
		1713	delete $self->{_rw} unless $self->{tls};
		1714	}
		1715
		1716	sub start_read {
		1717	my ($self) = @_;
		1718
		1719	unless ($self->{_rw} || $self->{_eof}) {
		1720	Scalar::Util::weaken $self;
		1721
		1722	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1723	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1724	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1725
		1726	if ($len > 0) {
		1727	$self->{_activity} = $self->{_ractivity} = AE::now;
		1728
		1729	if ($self->{tls}) {
		1730	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1731
		1732	&_dotls ($self);
		1733	} else {
		1734	$self->_drain_rbuf;
		1735	}
		1736
		1737	} elsif (defined $len) {
		1738	delete $self->{_rw};
		1739	$self->{_eof} = 1;
		1740	$self->_drain_rbuf;
		1741
		1742	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1743	return $self->_error ($!, 1);
		1744	}
		1745	};
		1746	}
		1747	}
		1748
		1749	our $ERROR_SYSCALL;
		1750	our $ERROR_WANT_READ;
		1751
		1752	sub _tls_error {
		1753	my ($self, $err) = @_;
		1754
		1755	return $self->_error ($!, 1)
		1756	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1757
		1758	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1759
		1760	# reduce error string to look less scary
		1761	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1762
		1763	if ($self->{_on_starttls}) {
		1764	(delete $self->{_on_starttls})->($self, undef, $err);
		1765	&_freetls;
		1766	} else {
		1767	&_freetls;
		1768	$self->_error (Errno::EPROTO, 1, $err);
		1769	}
		1770	}
		1771
		1772	# poll the write BIO and send the data if applicable
		1773	# also decode read data if possible
		1774	# this is basiclaly our TLS state machine
		1775	# more efficient implementations are possible with openssl,
		1776	# but not with the buggy and incomplete Net::SSLeay.
		1777	sub _dotls {
		1778	my ($self) = @_;
		1779
		1780	my $tmp;
		1781
		1782	if (length $self->{_tls_wbuf}) {
		1783	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1784	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1785	}
		1786
		1787	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1788	return $self->_tls_error ($tmp)
		1789	if $tmp != $ERROR_WANT_READ
		1790	&& ($tmp != $ERROR_SYSCALL || $!);
		1791	}
		1792
		1793	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1794	unless (length $tmp) {
		1795	$self->{_on_starttls}
		1796	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1797	&_freetls;
		1798
		1799	if ($self->{on_stoptls}) {
		1800	$self->{on_stoptls}($self);
		1801	return;
168	} else {	1802	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1803	# 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};	1804	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];	1805	$self->{_eof} = 1;
324	}	1806	}
325	}	1807	}
326	return;	1808
		1809	$self->{_tls_rbuf} .= $tmp;
		1810	$self->_drain_rbuf;
		1811	$self->{tls} or return; # tls session might have gone away in callback
		1812	}
		1813
		1814	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1815	return $self->_tls_error ($tmp)
		1816	if $tmp != $ERROR_WANT_READ
		1817	&& ($tmp != $ERROR_SYSCALL || $!);
		1818
		1819	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1820	$self->{wbuf} .= $tmp;
		1821	$self->_drain_wbuf;
		1822	}
		1823
		1824	$self->{_on_starttls}
		1825	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1826	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1827	}
		1828
		1829	=item $handle->starttls ($tls[, $tls_ctx])
		1830
		1831	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1832	object is created, you can also do that at a later time by calling
		1833	C<starttls>.
		1834
		1835	Starting TLS is currently an asynchronous operation - when you push some
		1836	write data and then call C<< ->starttls >> then TLS negotiation will start
		1837	immediately, after which the queued write data is then sent.
		1838
		1839	The first argument is the same as the C<tls> constructor argument (either
		1840	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1841
		1842	The second argument is the optional C<AnyEvent::TLS> object that is used
		1843	when AnyEvent::Handle has to create its own TLS connection object, or
		1844	a hash reference with C<< key => value >> pairs that will be used to
		1845	construct a new context.
		1846
		1847	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1848	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1849	changed to your liking. Note that the handshake might have already started
		1850	when this function returns.
		1851
		1852	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1853	handshakes on the same stream. Best do not attempt to use the stream after
		1854	stopping TLS.
		1855
		1856	=cut
		1857
		1858	our %TLS_CACHE; #TODO not yet documented, should we?
		1859
		1860	sub starttls {
		1861	my ($self, $tls, $ctx) = @_;
		1862
		1863	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1864	if $self->{tls};
		1865
		1866	$self->{tls} = $tls;
		1867	$self->{tls_ctx} = $ctx if @_ > 2;
		1868
		1869	return unless $self->{fh};
		1870
		1871	require Net::SSLeay;
		1872
		1873	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1874	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1875
		1876	$tls = delete $self->{tls};
		1877	$ctx = $self->{tls_ctx};
		1878
		1879	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1880
		1881	if ("HASH" eq ref $ctx) {
		1882	require AnyEvent::TLS;
		1883
		1884	if ($ctx->{cache}) {
		1885	my $key = $ctx+0;
		1886	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1887	} else {
		1888	$ctx = new AnyEvent::TLS %$ctx;
		1889	}
		1890	}
327	}	1891
		1892	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1893	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
328		1894
329	my $wba = shift @{$self->{write_bufs}}	1895	# basically, this is deep magic (because SSL_read should have the same issues)
330	or return;	1896	# but the openssl maintainers basically said: "trust us, it just works".
		1897	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1898	# and mismaintained ssleay-module doesn't even offer them).
		1899	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1900	#
		1901	# in short: this is a mess.
		1902	#
		1903	# note that we do not try to keep the length constant between writes as we are required to do.
		1904	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1905	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1906	# have identity issues in that area.
		1907	# Net::SSLeay::CTX_set_mode ($ssl,
		1908	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1909	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1910	Net::SSLeay::CTX_set_mode ($tls, 1|2);
331		1911
332	unless (defined $wba->[0]) {	1912	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
333	$wba->[1]->($self) if $wba->[1];	1913	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
334	$self->_check_writer;	1914
335	return;	1915	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1916
		1917	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1918
		1919	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1920	if $self->{on_starttls};
		1921
		1922	&_dotls; # need to trigger the initial handshake
		1923	$self->start_read; # make sure we actually do read
		1924	}
		1925
		1926	=item $handle->stoptls
		1927
		1928	Shuts down the SSL connection - this makes a proper EOF handshake by
		1929	sending a close notify to the other side, but since OpenSSL doesn't
		1930	support non-blocking shut downs, it is not guarenteed that you can re-use
		1931	the stream afterwards.
		1932
		1933	=cut
		1934
		1935	sub stoptls {
		1936	my ($self) = @_;
		1937
		1938	if ($self->{tls}) {
		1939	Net::SSLeay::shutdown ($self->{tls});
		1940
		1941	&_dotls;
		1942
		1943	# # we don't give a shit. no, we do, but we can't. no...#d#
		1944	# # we, we... have to use openssl :/#d#
		1945	# &_freetls;#d#
		1946	}
		1947	}
		1948
		1949	sub _freetls {
		1950	my ($self) = @_;
		1951
		1952	return unless $self->{tls};
		1953
		1954	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1955	if $self->{tls} > 0;
336	}	1956
		1957	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1958	}
337		1959
338	$self->{wbuf} = $wba->[0];	1960	sub DESTROY {
339	$self->{write_cb} = $wba->[1];	1961	my ($self) = @_;
340		1962
341	$self->{write_w} =	1963	&_freetls;
342	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1964
		1965	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1966
		1967	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1968	my $fh = delete $self->{fh};
		1969	my $wbuf = delete $self->{wbuf};
		1970
		1971	my @linger;
		1972
		1973	push @linger, AE::io $fh, 1, sub {
343	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1974	my $len = syswrite $fh, $wbuf, length $wbuf;
344		1975
345	if (not defined $l) {	1976	if ($len > 0) {
346	return if $! == EAGAIN || $! == EINTR;	1977	substr $wbuf, 0, $len, "";
347	delete $self->{write_w};
348	$self->{on_error}->($self) if $self->{on_error};
349
350	} else {	1978	} else {
351	substr $self->{wbuf}, 0, $l, '';	1979	@linger = (); # end
352
353	if (length ($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	}	1980	}
363	});	1981	};
		1982	push @linger, AE::timer $linger, 0, sub {
		1983	@linger = ();
		1984	};
		1985	}
		1986	}
		1987
		1988	=item $handle->destroy
		1989
		1990	Shuts down the handle object as much as possible - this call ensures that
		1991	no further callbacks will be invoked and as many resources as possible
		1992	will be freed. Any method you will call on the handle object after
		1993	destroying it in this way will be silently ignored (and it will return the
		1994	empty list).
		1995
		1996	Normally, you can just "forget" any references to an AnyEvent::Handle
		1997	object and it will simply shut down. This works in fatal error and EOF
		1998	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1999	callback, so when you want to destroy the AnyEvent::Handle object from
		2000	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2001	that case.
		2002
		2003	Destroying the handle object in this way has the advantage that callbacks
		2004	will be removed as well, so if those are the only reference holders (as
		2005	is common), then one doesn't need to do anything special to break any
		2006	reference cycles.
		2007
		2008	The handle might still linger in the background and write out remaining
		2009	data, as specified by the C<linger> option, however.
		2010
		2011	=cut
		2012
		2013	sub destroy {
		2014	my ($self) = @_;
		2015
		2016	$self->DESTROY;
		2017	%$self = ();
		2018	bless $self, "AnyEvent::Handle::destroyed";
		2019	}
		2020
		2021	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2022	#nop
		2023	}
		2024
		2025	=item AnyEvent::Handle::TLS_CTX
		2026
		2027	This function creates and returns the AnyEvent::TLS object used by default
		2028	for TLS mode.
		2029
		2030	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2031
		2032	=cut
		2033
		2034	our $TLS_CTX;
		2035
		2036	sub TLS_CTX() {
		2037	$TLS_CTX ||= do {
		2038	require AnyEvent::TLS;
		2039
		2040	new AnyEvent::TLS
		2041	}
364	}	2042	}
365		2043
366	=back	2044	=back
367		2045
		2046
		2047	=head1 NONFREQUENTLY ASKED QUESTIONS
		2048
		2049	=over 4
		2050
		2051	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2052	still get further invocations!
		2053
		2054	That's because AnyEvent::Handle keeps a reference to itself when handling
		2055	read or write callbacks.
		2056
		2057	It is only safe to "forget" the reference inside EOF or error callbacks,
		2058	from within all other callbacks, you need to explicitly call the C<<
		2059	->destroy >> method.
		2060
		2061	=item I get different callback invocations in TLS mode/Why can't I pause
		2062	reading?
		2063
		2064	Unlike, say, TCP, TLS connections do not consist of two independent
		2065	communication channels, one for each direction. Or put differently. The
		2066	read and write directions are not independent of each other: you cannot
		2067	write data unless you are also prepared to read, and vice versa.
		2068
		2069	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2070	callback invocations when you are not expecting any read data - the reason
		2071	is that AnyEvent::Handle always reads in TLS mode.
		2072
		2073	During the connection, you have to make sure that you always have a
		2074	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2075	connection (or when you no longer want to use it) you can call the
		2076	C<destroy> method.
		2077
		2078	=item How do I read data until the other side closes the connection?
		2079
		2080	If you just want to read your data into a perl scalar, the easiest way
		2081	to achieve this is by setting an C<on_read> callback that does nothing,
		2082	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2083	will be in C<$_[0]{rbuf}>:
		2084
		2085	$handle->on_read (sub { });
		2086	$handle->on_eof (undef);
		2087	$handle->on_error (sub {
		2088	my $data = delete $_[0]{rbuf};
		2089	});
		2090
		2091	The reason to use C<on_error> is that TCP connections, due to latencies
		2092	and packets loss, might get closed quite violently with an error, when in
		2093	fact, all data has been received.
		2094
		2095	It is usually better to use acknowledgements when transferring data,
		2096	to make sure the other side hasn't just died and you got the data
		2097	intact. This is also one reason why so many internet protocols have an
		2098	explicit QUIT command.
		2099
		2100	=item I don't want to destroy the handle too early - how do I wait until
		2101	all data has been written?
		2102
		2103	After writing your last bits of data, set the C<on_drain> callback
		2104	and destroy the handle in there - with the default setting of
		2105	C<low_water_mark> this will be called precisely when all data has been
		2106	written to the socket:
		2107
		2108	$handle->push_write (...);
		2109	$handle->on_drain (sub {
		2110	warn "all data submitted to the kernel\n";
		2111	undef $handle;
		2112	});
		2113
		2114	If you just want to queue some data and then signal EOF to the other side,
		2115	consider using C<< ->push_shutdown >> instead.
		2116
		2117	=item I want to contact a TLS/SSL server, I don't care about security.
		2118
		2119	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2120	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2121	parameter:
		2122
		2123	tcp_connect $host, $port, sub {
		2124	my ($fh) = @_;
		2125
		2126	my $handle = new AnyEvent::Handle
		2127	fh => $fh,
		2128	tls => "connect",
		2129	on_error => sub { ... };
		2130
		2131	$handle->push_write (...);
		2132	};
		2133
		2134	=item I want to contact a TLS/SSL server, I do care about security.
		2135
		2136	Then you should additionally enable certificate verification, including
		2137	peername verification, if the protocol you use supports it (see
		2138	L<AnyEvent::TLS>, C<verify_peername>).
		2139
		2140	E.g. for HTTPS:
		2141
		2142	tcp_connect $host, $port, sub {
		2143	my ($fh) = @_;
		2144
		2145	my $handle = new AnyEvent::Handle
		2146	fh => $fh,
		2147	peername => $host,
		2148	tls => "connect",
		2149	tls_ctx => { verify => 1, verify_peername => "https" },
		2150	...
		2151
		2152	Note that you must specify the hostname you connected to (or whatever
		2153	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2154	peername verification will be done.
		2155
		2156	The above will use the system-dependent default set of trusted CA
		2157	certificates. If you want to check against a specific CA, add the
		2158	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2159
		2160	tls_ctx => {
		2161	verify => 1,
		2162	verify_peername => "https",
		2163	ca_file => "my-ca-cert.pem",
		2164	},
		2165
		2166	=item I want to create a TLS/SSL server, how do I do that?
		2167
		2168	Well, you first need to get a server certificate and key. You have
		2169	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2170	self-signed certificate (cheap. check the search engine of your choice,
		2171	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2172	nice program for that purpose).
		2173
		2174	Then create a file with your private key (in PEM format, see
		2175	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2176	file should then look like this:
		2177
		2178	-----BEGIN RSA PRIVATE KEY-----
		2179	...header data
		2180	... lots of base64'y-stuff
		2181	-----END RSA PRIVATE KEY-----
		2182
		2183	-----BEGIN CERTIFICATE-----
		2184	... lots of base64'y-stuff
		2185	-----END CERTIFICATE-----
		2186
		2187	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2188	specify this file as C<cert_file>:
		2189
		2190	tcp_server undef, $port, sub {
		2191	my ($fh) = @_;
		2192
		2193	my $handle = new AnyEvent::Handle
		2194	fh => $fh,
		2195	tls => "accept",
		2196	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2197	...
		2198
		2199	When you have intermediate CA certificates that your clients might not
		2200	know about, just append them to the C<cert_file>.
		2201
		2202	=back
		2203
		2204
		2205	=head1 SUBCLASSING AnyEvent::Handle
		2206
		2207	In many cases, you might want to subclass AnyEvent::Handle.
		2208
		2209	To make this easier, a given version of AnyEvent::Handle uses these
		2210	conventions:
		2211
		2212	=over 4
		2213
		2214	=item * all constructor arguments become object members.
		2215
		2216	At least initially, when you pass a C<tls>-argument to the constructor it
		2217	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2218	mutated later on (for example C<tls> will hold the TLS connection object).
		2219
		2220	=item * other object member names are prefixed with an C<_>.
		2221
		2222	All object members not explicitly documented (internal use) are prefixed
		2223	with an underscore character, so the remaining non-C<_>-namespace is free
		2224	for use for subclasses.
		2225
		2226	=item * all members not documented here and not prefixed with an underscore
		2227	are free to use in subclasses.
		2228
		2229	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2230	member variables, but thats just life, at least it is documented.
		2231
		2232	=back
		2233
368	=head1 AUTHOR	2234	=head1 AUTHOR
369		2235
370	Robin Redeker, C<< <elmex at ta-sa.org> >>	2236	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
371		2237
372	=cut	2238	=cut
373		2239
374	1; # End of AnyEvent::Handle	2240	1; # End of AnyEvent::Handle

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