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Revision 1.2 by elmex, Sun Apr 27 17:27:34 2008 UTC vs.
Revision 1.198 by root, Tue Aug 31 01:03:37 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 streaming handles via AnyEvent
13
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut
19
20	our $VERSION = '0.01';
21		4
22	=head1 SYNOPSIS	5	=head1 SYNOPSIS
23		6
24	use AnyEvent;	7	use AnyEvent;
25	use AnyEvent::Handle;	8	use AnyEvent::Handle;
26		9
27	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
28		11
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
		13	fh => \*STDIN,
		14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	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 is a helper module to make it easier to do event-based I/O on
		36	stream-based filehandles (sockets, pipes, and other stream things).
		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
		41	In the following, where the documentation refers to "bytes", it means
		42	characters. As sysread and syswrite are used for all I/O, their
		43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
		48	All callbacks will be invoked with the handle object as their first
		49	argument.
		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	=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 that the
		124	default timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The peer's numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	If, for some reason, the handle is not acceptable, calling C<$retry>
		134	will continue with the next connection target (in case of multi-homed
		135	hosts or SRV records there can be multiple connection endpoints). At the
		136	time it is called the read and write queues, eof status, tls status and
		137	similar properties of the handle will have been reset.
		138
		139	In most cases, you should ignore the C<$retry> parameter.
		140
		141	=item on_connect_error => $cb->($handle, $message)
		142
		143	This callback is called when the connection could not be
		144	established. C<$!> will contain the relevant error code, and C<$message> a
		145	message describing it (usually the same as C<"$!">).
		146
		147	If this callback isn't specified, then C<on_error> will be called with a
		148	fatal error instead.
		149
		150	=back
		151
		152	=item on_error => $cb->($handle, $fatal, $message)
		153
		154	This is the error callback, which is called when, well, some error
		155	occured, such as not being able to resolve the hostname, failure to
		156	connect, or a read error.
		157
		158	Some errors are fatal (which is indicated by C<$fatal> being true). On
		159	fatal errors the handle object will be destroyed (by a call to C<< ->
		160	destroy >>) after invoking the error callback (which means you are free to
		161	examine the handle object). Examples of fatal errors are an EOF condition
		162	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		163	cases where the other side can close the connection at will, it is
		164	often easiest to not report C<EPIPE> errors in this callback.
		165
		166	AnyEvent::Handle tries to find an appropriate error code for you to check
		167	against, but in some cases (TLS errors), this does not work well. It is
		168	recommended to always output the C<$message> argument in human-readable
		169	error messages (it's usually the same as C<"$!">).
		170
		171	Non-fatal errors can be retried by returning, but it is recommended
		172	to simply ignore this parameter and instead abondon the handle object
		173	when this callback is invoked. Examples of non-fatal errors are timeouts
		174	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		175
		176	On entry to the callback, the value of C<$!> contains the operating
		177	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		178	C<EPROTO>).
		179
		180	While not mandatory, it is I<highly> recommended to set this callback, as
		181	you will not be notified of errors otherwise. The default just calls
		182	C<croak>.
		183
		184	=item on_read => $cb->($handle)
		185
		186	This sets the default read callback, which is called when data arrives
		187	and no read request is in the queue (unlike read queue callbacks, this
		188	callback will only be called when at least one octet of data is in the
		189	read buffer).
		190
		191	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		192	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		193	must not enlarge or modify the read buffer, you can only remove data at
		194	the beginning from it.
		195
		196	You can also call C<< ->push_read (...) >> or any other function that
		197	modifies the read queue. Or do both. Or ...
		198
		199	When an EOF condition is detected, AnyEvent::Handle will first try to
		200	feed all the remaining data to the queued callbacks and C<on_read> before
		201	calling the C<on_eof> callback. If no progress can be made, then a fatal
		202	error will be raised (with C<$!> set to C<EPIPE>).
		203
		204	Note that, unlike requests in the read queue, an C<on_read> callback
		205	doesn't mean you I<require> some data: if there is an EOF and there
		206	are outstanding read requests then an error will be flagged. With an
		207	C<on_read> callback, the C<on_eof> callback will be invoked.
		208
		209	=item on_eof => $cb->($handle)
		210
		211	Set the callback to be called when an end-of-file condition is detected,
		212	i.e. in the case of a socket, when the other side has closed the
		213	connection cleanly, and there are no outstanding read requests in the
		214	queue (if there are read requests, then an EOF counts as an unexpected
		215	connection close and will be flagged as an error).
		216
		217	For sockets, this just means that the other side has stopped sending data,
		218	you can still try to write data, and, in fact, one can return from the EOF
		219	callback and continue writing data, as only the read part has been shut
		220	down.
		221
		222	If an EOF condition has been detected but no C<on_eof> callback has been
		223	set, then a fatal error will be raised with C<$!> set to <0>.
		224
		225	=item on_drain => $cb->($handle)
		226
		227	This sets the callback that is called when the write buffer becomes empty
		228	(or immediately if the buffer is empty already).
		229
		230	To append to the write buffer, use the C<< ->push_write >> method.
		231
		232	This callback is useful when you don't want to put all of your write data
		233	into the queue at once, for example, when you want to write the contents
		234	of some file to the socket you might not want to read the whole file into
		235	memory and push it into the queue, but instead only read more data from
		236	the file when the write queue becomes empty.
		237
		238	=item timeout => $fractional_seconds
		239
		240	=item rtimeout => $fractional_seconds
		241
		242	=item wtimeout => $fractional_seconds
		243
		244	If non-zero, then these enables an "inactivity" timeout: whenever this
		245	many seconds pass without a successful read or write on the underlying
		246	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		247	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		248	error will be raised).
		249
		250	There are three variants of the timeouts that work independently
		251	of each other, for both read and write, just read, and just write:
		252	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		253	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		254	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		255
		256	Note that timeout processing is active even when you do not have
		257	any outstanding read or write requests: If you plan to keep the connection
		258	idle then you should disable the timeout temporarily or ignore the timeout
		259	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		260	restart the timeout.
		261
		262	Zero (the default) disables this timeout.
		263
		264	=item on_timeout => $cb->($handle)
		265
		266	Called whenever the inactivity timeout passes. If you return from this
		267	callback, then the timeout will be reset as if some activity had happened,
		268	so this condition is not fatal in any way.
		269
		270	=item rbuf_max => <bytes>
		271
		272	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		273	when the read buffer ever (strictly) exceeds this size. This is useful to
		274	avoid some forms of denial-of-service attacks.
		275
		276	For example, a server accepting connections from untrusted sources should
		277	be configured to accept only so-and-so much data that it cannot act on
		278	(for example, when expecting a line, an attacker could send an unlimited
		279	amount of data without a callback ever being called as long as the line
		280	isn't finished).
		281
		282	=item autocork => <boolean>
		283
		284	When disabled (the default), C<push_write> will try to immediately
		285	write the data to the handle if possible. This avoids having to register
		286	a write watcher and wait for the next event loop iteration, but can
		287	be inefficient if you write multiple small chunks (on the wire, this
		288	disadvantage is usually avoided by your kernel's nagle algorithm, see
		289	C<no_delay>, but this option can save costly syscalls).
		290
		291	When enabled, writes will always be queued till the next event loop
		292	iteration. This is efficient when you do many small writes per iteration,
		293	but less efficient when you do a single write only per iteration (or when
		294	the write buffer often is full). It also increases write latency.
		295
		296	=item no_delay => <boolean>
		297
		298	When doing small writes on sockets, your operating system kernel might
		299	wait a bit for more data before actually sending it out. This is called
		300	the Nagle algorithm, and usually it is beneficial.
		301
		302	In some situations you want as low a delay as possible, which can be
		303	accomplishd by setting this option to a true value.
		304
		305	The default is your operating system's default behaviour (most likely
		306	enabled). This option explicitly enables or disables it, if possible.
		307
		308	=item keepalive => <boolean>
		309
		310	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		311	normally, TCP connections have no time-out once established, so TCP
		312	connections, once established, can stay alive forever even when the other
		313	side has long gone. TCP keepalives are a cheap way to take down long-lived
		314	TCP connections when the other side becomes unreachable. While the default
		315	is OS-dependent, TCP keepalives usually kick in after around two hours,
		316	and, if the other side doesn't reply, take down the TCP connection some 10
		317	to 15 minutes later.
		318
		319	It is harmless to specify this option for file handles that do not support
		320	keepalives, and enabling it on connections that are potentially long-lived
		321	is usually a good idea.
		322
		323	=item oobinline => <boolean>
		324
		325	BSD majorly fucked up the implementation of TCP urgent data. The result
		326	is that almost no OS implements TCP according to the specs, and every OS
		327	implements it slightly differently.
		328
		329	If you want to handle TCP urgent data, then setting this flag (the default
		330	is enabled) gives you the most portable way of getting urgent data, by
		331	putting it into the stream.
		332
		333	Since BSD emulation of OOB data on top of TCP's urgent data can have
		334	security implications, AnyEvent::Handle sets this flag automatically
		335	unless explicitly specified. Note that setting this flag after
		336	establishing a connection I<may> be a bit too late (data loss could
		337	already have occured on BSD systems), but at least it will protect you
		338	from most attacks.
		339
		340	=item read_size => <bytes>
		341
		342	The default read block size (the number of bytes this module will
		343	try to read during each loop iteration, which affects memory
		344	requirements). Default: C<8192>.
		345
		346	=item low_water_mark => <bytes>
		347
		348	Sets the number of bytes (default: C<0>) that make up an "empty" write
		349	buffer: If the buffer reaches this size or gets even samller it is
		350	considered empty.
		351
		352	Sometimes it can be beneficial (for performance reasons) to add data to
		353	the write buffer before it is fully drained, but this is a rare case, as
		354	the operating system kernel usually buffers data as well, so the default
		355	is good in almost all cases.
		356
		357	=item linger => <seconds>
		358
		359	If this is non-zero (default: C<3600>), the destructor of the
		360	AnyEvent::Handle object will check whether there is still outstanding
		361	write data and will install a watcher that will write this data to the
		362	socket. No errors will be reported (this mostly matches how the operating
		363	system treats outstanding data at socket close time).
		364
		365	This will not work for partial TLS data that could not be encoded
		366	yet. This data will be lost. Calling the C<stoptls> method in time might
		367	help.
		368
		369	=item peername => $string
		370
		371	A string used to identify the remote site - usually the DNS hostname
		372	(I<not> IDN!) used to create the connection, rarely the IP address.
		373
		374	Apart from being useful in error messages, this string is also used in TLS
		375	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		376	verification will be skipped when C<peername> is not specified or is
		377	C<undef>.
		378
		379	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		380
		381	When this parameter is given, it enables TLS (SSL) mode, that means
		382	AnyEvent will start a TLS handshake as soon as the connection has been
		383	established and will transparently encrypt/decrypt data afterwards.
		384
		385	All TLS protocol errors will be signalled as C<EPROTO>, with an
		386	appropriate error message.
		387
		388	TLS mode requires Net::SSLeay to be installed (it will be loaded
		389	automatically when you try to create a TLS handle): this module doesn't
		390	have a dependency on that module, so if your module requires it, you have
		391	to add the dependency yourself.
		392
		393	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		394	C<accept>, and for the TLS client side of a connection, use C<connect>
		395	mode.
		396
		397	You can also provide your own TLS connection object, but you have
		398	to make sure that you call either C<Net::SSLeay::set_connect_state>
		399	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		400	AnyEvent::Handle. Also, this module will take ownership of this connection
		401	object.
		402
		403	At some future point, AnyEvent::Handle might switch to another TLS
		404	implementation, then the option to use your own session object will go
		405	away.
		406
		407	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		408	passing in the wrong integer will lead to certain crash. This most often
		409	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		410	segmentation fault.
		411
		412	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
		413
		414	=item tls_ctx => $anyevent_tls
		415
		416	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		417	(unless a connection object was specified directly). If this parameter is
		418	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		419
		420	Instead of an object, you can also specify a hash reference with C<< key
		421	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		422	new TLS context object.
		423
		424	=item on_starttls => $cb->($handle, $success[, $error_message])
		425
		426	This callback will be invoked when the TLS/SSL handshake has finished. If
		427	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		428	(C<on_stoptls> will not be called in this case).
		429
		430	The session in C<< $handle->{tls} >> can still be examined in this
		431	callback, even when the handshake was not successful.
		432
		433	TLS handshake failures will not cause C<on_error> to be invoked when this
		434	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		435
		436	Without this callback, handshake failures lead to C<on_error> being
		437	called as usual.
		438
		439	Note that you cannot just call C<starttls> again in this callback. If you
		440	need to do that, start an zero-second timer instead whose callback can
		441	then call C<< ->starttls >> again.
		442
		443	=item on_stoptls => $cb->($handle)
		444
		445	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		446	set, then it will be invoked after freeing the TLS session. If it is not,
		447	then a TLS shutdown condition will be treated like a normal EOF condition
		448	on the handle.
		449
		450	The session in C<< $handle->{tls} >> can still be examined in this
		451	callback.
		452
		453	This callback will only be called on TLS shutdowns, not when the
		454	underlying handle signals EOF.
		455
		456	=item json => JSON or JSON::XS object
		457
		458	This is the json coder object used by the C<json> read and write types.
		459
		460	If you don't supply it, then AnyEvent::Handle will create and use a
		461	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		462	texts.
		463
		464	Note that you are responsible to depend on the JSON module if you want to
		465	use this functionality, as AnyEvent does not have a dependency itself.
		466
		467	=back
		468
		469	=cut
		470
		471	sub new {
		472	my $class = shift;
		473	my $self = bless { @_ }, $class;
		474
		475	if ($self->{fh}) {
		476	$self->_start;
		477	return unless $self->{fh}; # could be gone by now
		478
		479	} elsif ($self->{connect}) {
		480	require AnyEvent::Socket;
		481
		482	$self->{peername} = $self->{connect}[0]
		483	unless exists $self->{peername};
		484
		485	$self->{_skip_drain_rbuf} = 1;
		486
		487	{
		488	Scalar::Util::weaken (my $self = $self);
		489
		490	$self->{_connect} =
		491	AnyEvent::Socket::tcp_connect (
		492	$self->{connect}[0],
		493	$self->{connect}[1],
		494	sub {
		495	my ($fh, $host, $port, $retry) = @_;
		496
		497	if ($fh) {
		498	$self->{fh} = $fh;
		499
		500	delete $self->{_skip_drain_rbuf};
		501	$self->_start;
		502
		503	$self->{on_connect}
		504	and $self->{on_connect}($self, $host, $port, sub {
		505	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		506	$self->{_skip_drain_rbuf} = 1;
		507	&$retry;
		508	});
		509
		510	} else {
		511	if ($self->{on_connect_error}) {
		512	$self->{on_connect_error}($self, "$!");
		513	$self->destroy;
		514	} else {
		515	$self->_error ($!, 1);
		516	}
		517	}
		518	},
		519	sub {
		520	local $self->{fh} = $_[0];
		521
		522	$self->{on_prepare}
		523	? $self->{on_prepare}->($self)
		524	: ()
		525	}
		526	);
		527	}
		528
		529	} else {
		530	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		531	}
		532
		533	$self
		534	}
		535
		536	sub _start {
		537	my ($self) = @_;
		538
		539	# too many clueless people try to use udp and similar sockets
		540	# with AnyEvent::Handle, do them a favour.
		541	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		542	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		543	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
		544
		545	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		546
		547	$self->{_activity} =
		548	$self->{_ractivity} =
		549	$self->{_wactivity} = AE::now;
		550
		551	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		552	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		553	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		554
		555	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		556	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		557
		558	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		559
		560	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		561	if $self->{tls};
		562
		563	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		564
		565	$self->start_read
		566	if $self->{on_read} || @{ $self->{_queue} };
		567
		568	$self->_drain_wbuf;
		569	}
		570
		571	sub _error {
		572	my ($self, $errno, $fatal, $message) = @_;
		573
		574	$! = $errno;
		575	$message ||= "$!";
		576
		577	if ($self->{on_error}) {
		578	$self->{on_error}($self, $fatal, $message);
		579	$self->destroy if $fatal;
		580	} elsif ($self->{fh} || $self->{connect}) {
		581	$self->destroy;
		582	Carp::croak "AnyEvent::Handle uncaught error: $message";
		583	}
		584	}
		585
		586	=item $fh = $handle->fh
		587
		588	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		589
		590	=cut
		591
		592	sub fh { $_[0]{fh} }
		593
		594	=item $handle->on_error ($cb)
		595
		596	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		597
		598	=cut
		599
		600	sub on_error {
		601	$_[0]{on_error} = $_[1];
		602	}
		603
		604	=item $handle->on_eof ($cb)
		605
		606	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		607
		608	=cut
		609
		610	sub on_eof {
		611	$_[0]{on_eof} = $_[1];
		612	}
		613
		614	=item $handle->on_timeout ($cb)
		615
		616	=item $handle->on_rtimeout ($cb)
		617
		618	=item $handle->on_wtimeout ($cb)
		619
		620	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		621	callback, or disables the callback (but not the timeout) if C<$cb> =
		622	C<undef>. See the C<timeout> constructor argument and method.
		623
		624	=cut
		625
		626	# see below
		627
		628	=item $handle->autocork ($boolean)
		629
		630	Enables or disables the current autocork behaviour (see C<autocork>
		631	constructor argument). Changes will only take effect on the next write.
		632
		633	=cut
		634
		635	sub autocork {
		636	$_[0]{autocork} = $_[1];
		637	}
		638
		639	=item $handle->no_delay ($boolean)
		640
		641	Enables or disables the C<no_delay> setting (see constructor argument of
		642	the same name for details).
		643
		644	=cut
		645
		646	sub no_delay {
		647	$_[0]{no_delay} = $_[1];
		648
		649	eval {
		650	local $SIG{__DIE__};
		651	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		652	if $_[0]{fh};
		653	};
		654	}
		655
		656	=item $handle->keepalive ($boolean)
		657
		658	Enables or disables the C<keepalive> setting (see constructor argument of
		659	the same name for details).
		660
		661	=cut
		662
		663	sub keepalive {
		664	$_[0]{keepalive} = $_[1];
		665
		666	eval {
		667	local $SIG{__DIE__};
		668	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		669	if $_[0]{fh};
		670	};
		671	}
		672
		673	=item $handle->oobinline ($boolean)
		674
		675	Enables or disables the C<oobinline> setting (see constructor argument of
		676	the same name for details).
		677
		678	=cut
		679
		680	sub oobinline {
		681	$_[0]{oobinline} = $_[1];
		682
		683	eval {
		684	local $SIG{__DIE__};
		685	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		686	if $_[0]{fh};
		687	};
		688	}
		689
		690	=item $handle->keepalive ($boolean)
		691
		692	Enables or disables the C<keepalive> setting (see constructor argument of
		693	the same name for details).
		694
		695	=cut
		696
		697	sub keepalive {
		698	$_[0]{keepalive} = $_[1];
		699
		700	eval {
		701	local $SIG{__DIE__};
		702	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		703	if $_[0]{fh};
		704	};
		705	}
		706
		707	=item $handle->on_starttls ($cb)
		708
		709	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		710
		711	=cut
		712
		713	sub on_starttls {
		714	$_[0]{on_starttls} = $_[1];
		715	}
		716
		717	=item $handle->on_stoptls ($cb)
		718
		719	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		720
		721	=cut
		722
		723	sub on_stoptls {
		724	$_[0]{on_stoptls} = $_[1];
		725	}
		726
		727	=item $handle->rbuf_max ($max_octets)
		728
		729	Configures the C<rbuf_max> setting (C<undef> disables it).
		730
		731	=cut
		732
		733	sub rbuf_max {
		734	$_[0]{rbuf_max} = $_[1];
		735	}
		736
		737	#############################################################################
		738
		739	=item $handle->timeout ($seconds)
		740
		741	=item $handle->rtimeout ($seconds)
		742
		743	=item $handle->wtimeout ($seconds)
		744
		745	Configures (or disables) the inactivity timeout.
		746
		747	=item $handle->timeout_reset
		748
		749	=item $handle->rtimeout_reset
		750
		751	=item $handle->wtimeout_reset
		752
		753	Reset the activity timeout, as if data was received or sent.
		754
		755	These methods are cheap to call.
		756
		757	=cut
		758
		759	for my $dir ("", "r", "w") {
		760	my $timeout = "${dir}timeout";
		761	my $tw = "_${dir}tw";
		762	my $on_timeout = "on_${dir}timeout";
		763	my $activity = "_${dir}activity";
		764	my $cb;
		765
		766	*$on_timeout = sub {
		767	$_[0]{$on_timeout} = $_[1];
		768	};
		769
		770	*$timeout = sub {
		771	my ($self, $new_value) = @_;
		772
		773	$self->{$timeout} = $new_value;
		774	delete $self->{$tw}; &$cb;
		775	};
		776
		777	*{"${dir}timeout_reset"} = sub {
		778	$_[0]{$activity} = AE::now;
		779	};
		780
		781	# main workhorse:
		782	# reset the timeout watcher, as neccessary
		783	# also check for time-outs
		784	$cb = sub {
		785	my ($self) = @_;
		786
		787	if ($self->{$timeout} && $self->{fh}) {
		788	my $NOW = AE::now;
		789
		790	# when would the timeout trigger?
		791	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		792
		793	# now or in the past already?
		794	if ($after <= 0) {
		795	$self->{$activity} = $NOW;
		796
		797	if ($self->{$on_timeout}) {
		798	$self->{$on_timeout}($self);
		799	} else {
		800	$self->_error (Errno::ETIMEDOUT);
		801	}
		802
		803	# callback could have changed timeout value, optimise
		804	return unless $self->{$timeout};
		805
		806	# calculate new after
		807	$after = $self->{$timeout};
		808	}
		809
		810	Scalar::Util::weaken $self;
		811	return unless $self; # ->error could have destroyed $self
		812
		813	$self->{$tw} ||= AE::timer $after, 0, sub {
		814	delete $self->{$tw};
		815	$cb->($self);
36	chomp;	816	};
37	print "Line: $_";	817	} else {
		818	delete $self->{$tw};
		819	}
		820	}
		821	}
		822
		823	#############################################################################
		824
		825	=back
		826
		827	=head2 WRITE QUEUE
		828
		829	AnyEvent::Handle manages two queues per handle, one for writing and one
		830	for reading.
		831
		832	The write queue is very simple: you can add data to its end, and
		833	AnyEvent::Handle will automatically try to get rid of it for you.
		834
		835	When data could be written and the write buffer is shorter then the low
		836	water mark, the C<on_drain> callback will be invoked.
		837
		838	=over 4
		839
		840	=item $handle->on_drain ($cb)
		841
		842	Sets the C<on_drain> callback or clears it (see the description of
		843	C<on_drain> in the constructor).
		844
		845	This method may invoke callbacks (and therefore the handle might be
		846	destroyed after it returns).
		847
		848	=cut
		849
		850	sub on_drain {
		851	my ($self, $cb) = @_;
		852
		853	$self->{on_drain} = $cb;
		854
		855	$cb->($self)
		856	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		857	}
		858
		859	=item $handle->push_write ($data)
		860
		861	Queues the given scalar to be written. You can push as much data as you
		862	want (only limited by the available memory), as C<AnyEvent::Handle>
		863	buffers it independently of the kernel.
		864
		865	This method may invoke callbacks (and therefore the handle might be
		866	destroyed after it returns).
		867
		868	=cut
		869
		870	sub _drain_wbuf {
		871	my ($self) = @_;
		872
		873	if (!$self->{_ww} && length $self->{wbuf}) {
		874
		875	Scalar::Util::weaken $self;
		876
		877	my $cb = sub {
		878	my $len = syswrite $self->{fh}, $self->{wbuf};
		879
		880	if (defined $len) {
		881	substr $self->{wbuf}, 0, $len, "";
		882
		883	$self->{_activity} = $self->{_wactivity} = AE::now;
		884
		885	$self->{on_drain}($self)
		886	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		887	&& $self->{on_drain};
		888
		889	delete $self->{_ww} unless length $self->{wbuf};
		890	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		891	$self->_error ($!, 1);
		892	}
		893	};
		894
		895	# try to write data immediately
		896	$cb->() unless $self->{autocork};
		897
		898	# if still data left in wbuf, we need to poll
		899	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		900	if length $self->{wbuf};
		901	};
		902	}
		903
		904	our %WH;
		905
		906	# deprecated
		907	sub register_write_type($$) {
		908	$WH{$_[0]} = $_[1];
		909	}
		910
		911	sub push_write {
		912	my $self = shift;
		913
		914	if (@_ > 1) {
		915	my $type = shift;
		916
		917	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		918	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		919	->($self, @_);
		920	}
		921
		922	# we downgrade here to avoid hard-to-track-down bugs,
		923	# and diagnose the problem earlier and better.
		924
		925	if ($self->{tls}) {
		926	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		927	&_dotls ($self) if $self->{fh};
		928	} else {
		929	utf8::downgrade $self->{wbuf} .= $_[0];
		930	$self->_drain_wbuf if $self->{fh};
		931	}
		932	}
		933
		934	=item $handle->push_write (type => @args)
		935
		936	Instead of formatting your data yourself, you can also let this module
		937	do the job by specifying a type and type-specific arguments. You
		938	can also specify the (fully qualified) name of a package, in which
		939	case AnyEvent tries to load the package and then expects to find the
		940	C<anyevent_write_type> function inside (see "custom write types", below).
		941
		942	Predefined types are (if you have ideas for additional types, feel free to
		943	drop by and tell us):
		944
		945	=over 4
		946
		947	=item netstring => $string
		948
		949	Formats the given value as netstring
		950	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		951
		952	=cut
		953
		954	register_write_type netstring => sub {
		955	my ($self, $string) = @_;
		956
		957	(length $string) . ":$string,"
		958	};
		959
		960	=item packstring => $format, $data
		961
		962	An octet string prefixed with an encoded length. The encoding C<$format>
		963	uses the same format as a Perl C<pack> format, but must specify a single
		964	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		965	optional C<!>, C<< < >> or C<< > >> modifier).
		966
		967	=cut
		968
		969	register_write_type packstring => sub {
		970	my ($self, $format, $string) = @_;
		971
		972	pack "$format/a*", $string
		973	};
		974
		975	=item json => $array_or_hashref
		976
		977	Encodes the given hash or array reference into a JSON object. Unless you
		978	provide your own JSON object, this means it will be encoded to JSON text
		979	in UTF-8.
		980
		981	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		982	one end of a handle and read them at the other end without using any
		983	additional framing.
		984
		985	The generated JSON text is guaranteed not to contain any newlines: While
		986	this module doesn't need delimiters after or between JSON texts to be
		987	able to read them, many other languages depend on that.
		988
		989	A simple RPC protocol that interoperates easily with others is to send
		990	JSON arrays (or objects, although arrays are usually the better choice as
		991	they mimic how function argument passing works) and a newline after each
		992	JSON text:
		993
		994	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		995	$handle->push_write ("\012");
		996
		997	An AnyEvent::Handle receiver would simply use the C<json> read type and
		998	rely on the fact that the newline will be skipped as leading whitespace:
		999
		1000	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1001
		1002	Other languages could read single lines terminated by a newline and pass
		1003	this line into their JSON decoder of choice.
		1004
		1005	=cut
		1006
		1007	sub json_coder() {
		1008	eval { require JSON::XS; JSON::XS->new->utf8 }
		1009	|| do { require JSON; JSON->new->utf8 }
		1010	}
		1011
		1012	register_write_type json => sub {
		1013	my ($self, $ref) = @_;
		1014
		1015	my $json = $self->{json} ||= json_coder;
		1016
		1017	$json->encode ($ref)
		1018	};
		1019
		1020	=item storable => $reference
		1021
		1022	Freezes the given reference using L<Storable> and writes it to the
		1023	handle. Uses the C<nfreeze> format.
		1024
		1025	=cut
		1026
		1027	register_write_type storable => sub {
		1028	my ($self, $ref) = @_;
		1029
		1030	require Storable;
		1031
		1032	pack "w/a*", Storable::nfreeze ($ref)
		1033	};
		1034
		1035	=back
		1036
		1037	=item $handle->push_shutdown
		1038
		1039	Sometimes you know you want to close the socket after writing your data
		1040	before it was actually written. One way to do that is to replace your
		1041	C<on_drain> handler by a callback that shuts down the socket (and set
		1042	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1043	replaces the C<on_drain> callback with:
		1044
		1045	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1046
		1047	This simply shuts down the write side and signals an EOF condition to the
		1048	the peer.
		1049
		1050	You can rely on the normal read queue and C<on_eof> handling
		1051	afterwards. This is the cleanest way to close a connection.
		1052
		1053	This method may invoke callbacks (and therefore the handle might be
		1054	destroyed after it returns).
		1055
		1056	=cut
		1057
		1058	sub push_shutdown {
		1059	my ($self) = @_;
		1060
		1061	delete $self->{low_water_mark};
		1062	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1063	}
		1064
		1065	=item custom write types - Package::anyevent_write_type $handle, @args
		1066
		1067	Instead of one of the predefined types, you can also specify the name of
		1068	a package. AnyEvent will try to load the package and then expects to find
		1069	a function named C<anyevent_write_type> inside. If it isn't found, it
		1070	progressively tries to load the parent package until it either finds the
		1071	function (good) or runs out of packages (bad).
		1072
		1073	Whenever the given C<type> is used, C<push_write> will the function with
		1074	the handle object and the remaining arguments.
		1075
		1076	The function is supposed to return a single octet string that will be
		1077	appended to the write buffer, so you cna mentally treat this function as a
		1078	"arguments to on-the-wire-format" converter.
		1079
		1080	Example: implement a custom write type C<join> that joins the remaining
		1081	arguments using the first one.
		1082
		1083	$handle->push_write (My::Type => " ", 1,2,3);
		1084
		1085	# uses the following package, which can be defined in the "My::Type" or in
		1086	# the "My" modules to be auto-loaded, or just about anywhere when the
		1087	# My::Type::anyevent_write_type is defined before invoking it.
		1088
		1089	package My::Type;
		1090
		1091	sub anyevent_write_type {
		1092	my ($handle, $delim, @args) = @_;
		1093
		1094	join $delim, @args
		1095	}
		1096
		1097	=cut
		1098
		1099	#############################################################################
		1100
		1101	=back
		1102
		1103	=head2 READ QUEUE
		1104
		1105	AnyEvent::Handle manages two queues per handle, one for writing and one
		1106	for reading.
		1107
		1108	The read queue is more complex than the write queue. It can be used in two
		1109	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1110	a queue.
		1111
		1112	In the simple case, you just install an C<on_read> callback and whenever
		1113	new data arrives, it will be called. You can then remove some data (if
		1114	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
		1115	leave the data there if you want to accumulate more (e.g. when only a
		1116	partial message has been received so far), or change the read queue with
		1117	e.g. C<push_read>.
		1118
		1119	In the more complex case, you want to queue multiple callbacks. In this
		1120	case, AnyEvent::Handle will call the first queued callback each time new
		1121	data arrives (also the first time it is queued) and remove it when it has
		1122	done its job (see C<push_read>, below).
		1123
		1124	This way you can, for example, push three line-reads, followed by reading
		1125	a chunk of data, and AnyEvent::Handle will execute them in order.
		1126
		1127	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1128	the specified number of bytes which give an XML datagram.
		1129
		1130	# in the default state, expect some header bytes
		1131	$handle->on_read (sub {
		1132	# some data is here, now queue the length-header-read (4 octets)
		1133	shift->unshift_read (chunk => 4, sub {
		1134	# header arrived, decode
		1135	my $len = unpack "N", $_[1];
		1136
		1137	# now read the payload
		1138	shift->unshift_read (chunk => $len, sub {
		1139	my $xml = $_[1];
		1140	# handle xml
		1141	});
		1142	});
		1143	});
		1144
		1145	Example 2: Implement a client for a protocol that replies either with "OK"
		1146	and another line or "ERROR" for the first request that is sent, and 64
		1147	bytes for the second request. Due to the availability of a queue, we can
		1148	just pipeline sending both requests and manipulate the queue as necessary
		1149	in the callbacks.
		1150
		1151	When the first callback is called and sees an "OK" response, it will
		1152	C<unshift> another line-read. This line-read will be queued I<before> the
		1153	64-byte chunk callback.
		1154
		1155	# request one, returns either "OK + extra line" or "ERROR"
		1156	$handle->push_write ("request 1\015\012");
		1157
		1158	# we expect "ERROR" or "OK" as response, so push a line read
		1159	$handle->push_read (line => sub {
		1160	# if we got an "OK", we have to _prepend_ another line,
		1161	# so it will be read before the second request reads its 64 bytes
		1162	# which are already in the queue when this callback is called
		1163	# we don't do this in case we got an error
		1164	if ($_[1] eq "OK") {
		1165	$_[0]->unshift_read (line => sub {
		1166	my $response = $_[1];
		1167	...
		1168	});
38	}	1169	}
39	});	1170	});
40		1171
41	# or use the constructor to pass the callback:	1172	# request two, simply returns 64 octets
		1173	$handle->push_write ("request 2\015\012");
42		1174
43	my $ae_fh2 =	1175	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1176	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1177	my $response = $_[1];
46	on_eof => sub {	1178	...
47	$cv->broadcast;	1179	});
48	},	1180
49	on_readline => sub {	1181	=over 4
50	my ($ae_fh, @lines) = @_;	1182
51	for (@lines) {	1183	=cut
52	chomp;	1184
53	print "Line: $_";	1185	sub _drain_rbuf {
		1186	my ($self) = @_;
		1187
		1188	# avoid recursion
		1189	return if $self->{_skip_drain_rbuf};
		1190	local $self->{_skip_drain_rbuf} = 1;
		1191
		1192	while () {
		1193	# we need to use a separate tls read buffer, as we must not receive data while
		1194	# we are draining the buffer, and this can only happen with TLS.
		1195	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1196	if exists $self->{_tls_rbuf};
		1197
		1198	my $len = length $self->{rbuf};
		1199
		1200	if (my $cb = shift @{ $self->{_queue} }) {
		1201	unless ($cb->($self)) {
		1202	# no progress can be made
		1203	# (not enough data and no data forthcoming)
		1204	$self->_error (Errno::EPIPE, 1), return
		1205	if $self->{_eof};
		1206
		1207	unshift @{ $self->{_queue} }, $cb;
54	}	1208	last;
55	}	1209	}
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}) {	1210	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1211	last unless $len;
122		1212
		1213	$self->{on_read}($self);
		1214
		1215	if (
		1216	$len == length $self->{rbuf} # if no data has been consumed
		1217	&& !@{ $self->{_queue} } # and the queue is still empty
		1218	&& $self->{on_read} # but we still have on_read
		1219	) {
		1220	# no further data will arrive
		1221	# so no progress can be made
		1222	$self->_error (Errno::EPIPE, 1), return
		1223	if $self->{_eof};
		1224
		1225	last; # more data might arrive
		1226	}
		1227	} else {
		1228	# read side becomes idle
		1229	delete $self->{_rw} unless $self->{tls};
		1230	last;
		1231	}
		1232	}
		1233
123	} elsif ($self->{on_eof}) {	1234	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1235	$self->{on_eof}
		1236	? $self->{on_eof}($self)
		1237	: $self->_error (0, 1, "Unexpected end-of-file");
125		1238
126	} elsif ($self->{on_error}) {	1239	return;
127	$self->on_eof ($self->{on_error});
128	}	1240	}
129		1241
130	return $self	1242	if (
131	}	1243	defined $self->{rbuf_max}
		1244	&& $self->{rbuf_max} < length $self->{rbuf}
		1245	) {
		1246	$self->_error (Errno::ENOSPC, 1), return;
		1247	}
132		1248
133	=item B<fh>	1249	# may need to restart read watcher
		1250	unless ($self->{_rw}) {
		1251	$self->start_read
		1252	if $self->{on_read} || @{ $self->{_queue} };
		1253	}
		1254	}
134		1255
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1256	=item $handle->on_read ($cb)
136		1257
137	=cut	1258	This replaces the currently set C<on_read> callback, or clears it (when
		1259	the new callback is C<undef>). See the description of C<on_read> in the
		1260	constructor.
138		1261
139	sub fh { $_[0]->{fh} }	1262	This method may invoke callbacks (and therefore the handle might be
140		1263	destroyed after it returns).
141	=item B<on_read ($callback)>
142
143	This method installs a C<$callback> that will be called
144	when new data arrived. You can access the read buffer via the C<rbuf>
145	method (see below).
146
147	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
148		1264
149	=cut	1265	=cut
150		1266
151	sub on_read {	1267	sub on_read {
152	my ($self, $cb) = @_;	1268	my ($self, $cb) = @_;
		1269
153	$self->{on_read} = $cb;	1270	$self->{on_read} = $cb;
		1271	$self->_drain_rbuf if $cb;
		1272	}
154		1273
155	unless (defined $self->{on_read}) {	1274	=item $handle->rbuf
156	delete $self->{on_read_w};	1275
		1276	Returns the read buffer (as a modifiable lvalue).
		1277
		1278	You can access the read buffer directly as the C<< ->{rbuf} >>
		1279	member, if you want. However, the only operation allowed on the
		1280	read buffer (apart from looking at it) is removing data from its
		1281	beginning. Otherwise modifying or appending to it is not allowed and will
		1282	lead to hard-to-track-down bugs.
		1283
		1284	NOTE: The read buffer should only be used or modified if the C<on_read>,
		1285	C<push_read> or C<unshift_read> methods are used. The other read methods
		1286	automatically manage the read buffer.
		1287
		1288	=cut
		1289
		1290	sub rbuf : lvalue {
		1291	$_[0]{rbuf}
		1292	}
		1293
		1294	=item $handle->push_read ($cb)
		1295
		1296	=item $handle->unshift_read ($cb)
		1297
		1298	Append the given callback to the end of the queue (C<push_read>) or
		1299	prepend it (C<unshift_read>).
		1300
		1301	The callback is called each time some additional read data arrives.
		1302
		1303	It must check whether enough data is in the read buffer already.
		1304
		1305	If not enough data is available, it must return the empty list or a false
		1306	value, in which case it will be called repeatedly until enough data is
		1307	available (or an error condition is detected).
		1308
		1309	If enough data was available, then the callback must remove all data it is
		1310	interested in (which can be none at all) and return a true value. After returning
		1311	true, it will be removed from the queue.
		1312
		1313	These methods may invoke callbacks (and therefore the handle might be
		1314	destroyed after it returns).
		1315
		1316	=cut
		1317
		1318	our %RH;
		1319
		1320	sub register_read_type($$) {
		1321	$RH{$_[0]} = $_[1];
		1322	}
		1323
		1324	sub push_read {
		1325	my $self = shift;
		1326	my $cb = pop;
		1327
		1328	if (@_) {
		1329	my $type = shift;
		1330
		1331	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1332	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1333	->($self, $cb, @_);
		1334	}
		1335
		1336	push @{ $self->{_queue} }, $cb;
		1337	$self->_drain_rbuf;
		1338	}
		1339
		1340	sub unshift_read {
		1341	my $self = shift;
		1342	my $cb = pop;
		1343
		1344	if (@_) {
		1345	my $type = shift;
		1346
		1347	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1348	->($self, $cb, @_);
		1349	}
		1350
		1351	unshift @{ $self->{_queue} }, $cb;
		1352	$self->_drain_rbuf;
		1353	}
		1354
		1355	=item $handle->push_read (type => @args, $cb)
		1356
		1357	=item $handle->unshift_read (type => @args, $cb)
		1358
		1359	Instead of providing a callback that parses the data itself you can chose
		1360	between a number of predefined parsing formats, for chunks of data, lines
		1361	etc. You can also specify the (fully qualified) name of a package, in
		1362	which case AnyEvent tries to load the package and then expects to find the
		1363	C<anyevent_read_type> function inside (see "custom read types", below).
		1364
		1365	Predefined types are (if you have ideas for additional types, feel free to
		1366	drop by and tell us):
		1367
		1368	=over 4
		1369
		1370	=item chunk => $octets, $cb->($handle, $data)
		1371
		1372	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1373	data read to the callback. The callback will never be called with less
		1374	data.
		1375
		1376	Example: read 2 bytes.
		1377
		1378	$handle->push_read (chunk => 2, sub {
		1379	warn "yay ", unpack "H*", $_[1];
		1380	});
		1381
		1382	=cut
		1383
		1384	register_read_type chunk => sub {
		1385	my ($self, $cb, $len) = @_;
		1386
		1387	sub {
		1388	$len <= length $_[0]{rbuf} or return;
		1389	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1390	1
		1391	}
		1392	};
		1393
		1394	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1395
		1396	The callback will be called only once a full line (including the end of
		1397	line marker, C<$eol>) has been read. This line (excluding the end of line
		1398	marker) will be passed to the callback as second argument (C<$line>), and
		1399	the end of line marker as the third argument (C<$eol>).
		1400
		1401	The end of line marker, C<$eol>, can be either a string, in which case it
		1402	will be interpreted as a fixed record end marker, or it can be a regex
		1403	object (e.g. created by C<qr>), in which case it is interpreted as a
		1404	regular expression.
		1405
		1406	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1407	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1408	protocols).
		1409
		1410	Partial lines at the end of the stream will never be returned, as they are
		1411	not marked by the end of line marker.
		1412
		1413	=cut
		1414
		1415	register_read_type line => sub {
		1416	my ($self, $cb, $eol) = @_;
		1417
		1418	if (@_ < 3) {
		1419	# this is more than twice as fast as the generic code below
		1420	sub {
		1421	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1422
		1423	$cb->($_[0], $1, $2);
		1424	1
		1425	}
		1426	} else {
		1427	$eol = quotemeta $eol unless ref $eol;
		1428	$eol = qr|^(.*?)($eol)|s;
		1429
		1430	sub {
		1431	$_[0]{rbuf} =~ s/$eol// or return;
		1432
		1433	$cb->($_[0], $1, $2);
		1434	1
		1435	}
		1436	}
		1437	};
		1438
		1439	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1440
		1441	Makes a regex match against the regex object C<$accept> and returns
		1442	everything up to and including the match.
		1443
		1444	Example: read a single line terminated by '\n'.
		1445
		1446	$handle->push_read (regex => qr<\n>, sub { ... });
		1447
		1448	If C<$reject> is given and not undef, then it determines when the data is
		1449	to be rejected: it is matched against the data when the C<$accept> regex
		1450	does not match and generates an C<EBADMSG> error when it matches. This is
		1451	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1452	receive buffer overflow).
		1453
		1454	Example: expect a single decimal number followed by whitespace, reject
		1455	anything else (not the use of an anchor).
		1456
		1457	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1458
		1459	If C<$skip> is given and not C<undef>, then it will be matched against
		1460	the receive buffer when neither C<$accept> nor C<$reject> match,
		1461	and everything preceding and including the match will be accepted
		1462	unconditionally. This is useful to skip large amounts of data that you
		1463	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1464	have to start matching from the beginning. This is purely an optimisation
		1465	and is usually worth it only when you expect more than a few kilobytes.
		1466
		1467	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1468	expect the header to be very large (it isn't in practice, but...), we use
		1469	a skip regex to skip initial portions. The skip regex is tricky in that
		1470	it only accepts something not ending in either \015 or \012, as these are
		1471	required for the accept regex.
		1472
		1473	$handle->push_read (regex =>
		1474	qr<\015\012\015\012>,
		1475	undef, # no reject
		1476	qr<^.*[^\015\012]>,
		1477	sub { ... });
		1478
		1479	=cut
		1480
		1481	register_read_type regex => sub {
		1482	my ($self, $cb, $accept, $reject, $skip) = @_;
		1483
		1484	my $data;
		1485	my $rbuf = \$self->{rbuf};
		1486
		1487	sub {
		1488	# accept
		1489	if ($$rbuf =~ $accept) {
		1490	$data .= substr $$rbuf, 0, $+[0], "";
		1491	$cb->($self, $data);
		1492	return 1;
		1493	}
		1494
		1495	# reject
		1496	if ($reject && $$rbuf =~ $reject) {
		1497	$self->_error (Errno::EBADMSG);
		1498	}
		1499
		1500	# skip
		1501	if ($skip && $$rbuf =~ $skip) {
		1502	$data .= substr $$rbuf, 0, $+[0], "";
		1503	}
		1504
		1505	()
		1506	}
		1507	};
		1508
		1509	=item netstring => $cb->($handle, $string)
		1510
		1511	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1512
		1513	Throws an error with C<$!> set to EBADMSG on format violations.
		1514
		1515	=cut
		1516
		1517	register_read_type netstring => sub {
		1518	my ($self, $cb) = @_;
		1519
		1520	sub {
		1521	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1522	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1523	$self->_error (Errno::EBADMSG);
		1524	}
157	return;	1525	return;
		1526	}
		1527
		1528	my $len = $1;
		1529
		1530	$self->unshift_read (chunk => $len, sub {
		1531	my $string = $_[1];
		1532	$_[0]->unshift_read (chunk => 1, sub {
		1533	if ($_[1] eq ",") {
		1534	$cb->($_[0], $string);
		1535	} else {
		1536	$self->_error (Errno::EBADMSG);
		1537	}
		1538	});
		1539	});
		1540
		1541	1
		1542	}
		1543	};
		1544
		1545	=item packstring => $format, $cb->($handle, $string)
		1546
		1547	An octet string prefixed with an encoded length. The encoding C<$format>
		1548	uses the same format as a Perl C<pack> format, but must specify a single
		1549	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1550	optional C<!>, C<< < >> or C<< > >> modifier).
		1551
		1552	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1553	EPP uses a prefix of C<N> (4 octtes).
		1554
		1555	Example: read a block of data prefixed by its length in BER-encoded
		1556	format (very efficient).
		1557
		1558	$handle->push_read (packstring => "w", sub {
		1559	my ($handle, $data) = @_;
158	}	1560	});
159		1561
160	$self->{on_read_w} =	1562	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1563
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1564	register_read_type packstring => sub {
		1565	my ($self, $cb, $format) = @_;
		1566
		1567	sub {
		1568	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1569	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1570	or return;
		1571
		1572	$format = length pack $format, $len;
		1573
		1574	# bypass unshift if we already have the remaining chunk
		1575	if ($format + $len <= length $_[0]{rbuf}) {
		1576	my $data = substr $_[0]{rbuf}, $format, $len;
		1577	substr $_[0]{rbuf}, 0, $format + $len, "";
		1578	$cb->($_[0], $data);
		1579	} else {
		1580	# remove prefix
		1581	substr $_[0]{rbuf}, 0, $format, "";
		1582
		1583	# read remaining chunk
		1584	$_[0]->unshift_read (chunk => $len, $cb);
		1585	}
		1586
		1587	1
		1588	}
		1589	};
		1590
		1591	=item json => $cb->($handle, $hash_or_arrayref)
		1592
		1593	Reads a JSON object or array, decodes it and passes it to the
		1594	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1595
		1596	If a C<json> object was passed to the constructor, then that will be used
		1597	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1598
		1599	This read type uses the incremental parser available with JSON version
		1600	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1601	dependency on your own: this module will load the JSON module, but
		1602	AnyEvent does not depend on it itself.
		1603
		1604	Since JSON texts are fully self-delimiting, the C<json> read and write
		1605	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1606	the C<json> write type description, above, for an actual example.
		1607
		1608	=cut
		1609
		1610	register_read_type json => sub {
		1611	my ($self, $cb) = @_;
		1612
		1613	my $json = $self->{json} ||= json_coder;
		1614
		1615	my $data;
163	my $rbuf_len = length $self->{rbuf};	1616	my $rbuf = \$self->{rbuf};
164	my $l;	1617
165	if (defined $self->{read_size}) {	1618	sub {
166	$l = sysread $self->{fh}, $self->{rbuf},	1619	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1620
		1621	if ($ref) {
		1622	$self->{rbuf} = $json->incr_text;
		1623	$json->incr_text = "";
		1624	$cb->($self, $ref);
		1625
		1626	1
		1627	} elsif ($@) {
		1628	# error case
		1629	$json->incr_skip;
		1630
		1631	$self->{rbuf} = $json->incr_text;
		1632	$json->incr_text = "";
		1633
		1634	$self->_error (Errno::EBADMSG);
		1635
		1636	()
		1637	} else {
		1638	$self->{rbuf} = "";
		1639
		1640	()
		1641	}
		1642	}
		1643	};
		1644
		1645	=item storable => $cb->($handle, $ref)
		1646
		1647	Deserialises a L<Storable> frozen representation as written by the
		1648	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1649	data).
		1650
		1651	Raises C<EBADMSG> error if the data could not be decoded.
		1652
		1653	=cut
		1654
		1655	register_read_type storable => sub {
		1656	my ($self, $cb) = @_;
		1657
		1658	require Storable;
		1659
		1660	sub {
		1661	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1662	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1663	or return;
		1664
		1665	my $format = length pack "w", $len;
		1666
		1667	# bypass unshift if we already have the remaining chunk
		1668	if ($format + $len <= length $_[0]{rbuf}) {
		1669	my $data = substr $_[0]{rbuf}, $format, $len;
		1670	substr $_[0]{rbuf}, 0, $format + $len, "";
		1671	$cb->($_[0], Storable::thaw ($data));
		1672	} else {
		1673	# remove prefix
		1674	substr $_[0]{rbuf}, 0, $format, "";
		1675
		1676	# read remaining chunk
		1677	$_[0]->unshift_read (chunk => $len, sub {
		1678	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1679	$cb->($_[0], $ref);
		1680	} else {
		1681	$self->_error (Errno::EBADMSG);
		1682	}
		1683	});
		1684	}
		1685
		1686	1
		1687	}
		1688	};
		1689
		1690	=back
		1691
		1692	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1693
		1694	Instead of one of the predefined types, you can also specify the name
		1695	of a package. AnyEvent will try to load the package and then expects to
		1696	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1697	progressively tries to load the parent package until it either finds the
		1698	function (good) or runs out of packages (bad).
		1699
		1700	Whenever this type is used, C<push_read> will invoke the function with the
		1701	handle object, the original callback and the remaining arguments.
		1702
		1703	The function is supposed to return a callback (usually a closure) that
		1704	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1705	mentally treat the function as a "configurable read type to read callback"
		1706	converter.
		1707
		1708	It should invoke the original callback when it is done reading (remember
		1709	to pass C<$handle> as first argument as all other callbacks do that,
		1710	although there is no strict requirement on this).
		1711
		1712	For examples, see the source of this module (F<perldoc -m
		1713	AnyEvent::Handle>, search for C<register_read_type>)).
		1714
		1715	=item $handle->stop_read
		1716
		1717	=item $handle->start_read
		1718
		1719	In rare cases you actually do not want to read anything from the
		1720	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1721	any queued callbacks will be executed then. To start reading again, call
		1722	C<start_read>.
		1723
		1724	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1725	you change the C<on_read> callback or push/unshift a read callback, and it
		1726	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1727	there are any read requests in the queue.
		1728
		1729	These methods will have no effect when in TLS mode (as TLS doesn't support
		1730	half-duplex connections).
		1731
		1732	=cut
		1733
		1734	sub stop_read {
		1735	my ($self) = @_;
		1736
		1737	delete $self->{_rw} unless $self->{tls};
		1738	}
		1739
		1740	sub start_read {
		1741	my ($self) = @_;
		1742
		1743	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		1744	Scalar::Util::weaken $self;
		1745
		1746	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1747	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1748	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1749
		1750	if ($len > 0) {
		1751	$self->{_activity} = $self->{_ractivity} = AE::now;
		1752
		1753	if ($self->{tls}) {
		1754	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1755
		1756	&_dotls ($self);
		1757	} else {
		1758	$self->_drain_rbuf;
		1759	}
		1760
		1761	} elsif (defined $len) {
		1762	delete $self->{_rw};
		1763	$self->{_eof} = 1;
		1764	$self->_drain_rbuf;
		1765
		1766	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1767	return $self->_error ($!, 1);
		1768	}
		1769	};
		1770	}
		1771	}
		1772
		1773	our $ERROR_SYSCALL;
		1774	our $ERROR_WANT_READ;
		1775
		1776	sub _tls_error {
		1777	my ($self, $err) = @_;
		1778
		1779	return $self->_error ($!, 1)
		1780	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1781
		1782	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1783
		1784	# reduce error string to look less scary
		1785	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1786
		1787	if ($self->{_on_starttls}) {
		1788	(delete $self->{_on_starttls})->($self, undef, $err);
		1789	&_freetls;
		1790	} else {
		1791	&_freetls;
		1792	$self->_error (Errno::EPROTO, 1, $err);
		1793	}
		1794	}
		1795
		1796	# poll the write BIO and send the data if applicable
		1797	# also decode read data if possible
		1798	# this is basiclaly our TLS state machine
		1799	# more efficient implementations are possible with openssl,
		1800	# but not with the buggy and incomplete Net::SSLeay.
		1801	sub _dotls {
		1802	my ($self) = @_;
		1803
		1804	my $tmp;
		1805
		1806	if (length $self->{_tls_wbuf}) {
		1807	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1808	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1809	}
		1810
		1811	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1812	return $self->_tls_error ($tmp)
		1813	if $tmp != $ERROR_WANT_READ
		1814	&& ($tmp != $ERROR_SYSCALL || $!);
		1815	}
		1816
		1817	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1818	unless (length $tmp) {
		1819	$self->{_on_starttls}
		1820	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1821	&_freetls;
		1822
		1823	if ($self->{on_stoptls}) {
		1824	$self->{on_stoptls}($self);
		1825	return;
168	} else {	1826	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1827	# 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};	1828	delete $self->{_rw};
177
178	} elsif ($l == 0) {
179	$self->{on_eof}->($self) if $self->{on_eof};
180	delete $self->{on_read_w};
181
182	} else {
183	$self->{on_read}->($self);
184	}
185	});
186	}
187
188	=item B<on_error ($callback)>
189
190	Whenever a read or write operation resulted in an error the C<$callback>
191	will be called.
192
193	The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself.
194	The error is given as errno in C<$!>.
195
196	=cut
197
198	sub on_error {
199	$_[0]->{on_error} = $_[1];
200	}
201
202	=item B<on_eof ($callback)>
203
204	Installs the C<$callback> that will be called when the end of file is
205	encountered in a read operation this C<$callback> will be called. The first
206	argument will be the L<AnyEvent::Handle> object itself.
207
208	=cut
209
210	sub on_eof {
211	$_[0]->{on_eof} = $_[1];
212	}
213
214	=item B<rbuf>
215
216	Returns a reference to the read buffer.
217
218	NOTE: The read buffer should only be used or modified if the C<on_read>
219	method is used directly. The C<read> and C<readlines> methods will provide
220	the read data to their callbacks.
221
222	=cut
223
224	sub rbuf : lvalue {
225	$_[0]->{rbuf}
226	}
227
228	=item B<read ($len, $callback)>
229
230	Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
231	if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
232	object itself and the second argument the read data.
233
234	NOTE: This method will override any callbacks installed via the C<on_read> method.
235
236	=cut
237
238	sub read {
239	my ($self, $len, $cb) = @_;
240
241	$self->{read_cb} = $cb;
242	my $old_blk_size = $self->{read_block_size};
243	$self->{read_block_size} = $len;
244
245	$self->on_read (sub {
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
247
248	if ($len == length $_[0]->{rbuf}) {
249	$_[0]->{read_block_size} = $old_blk_size;
250	$_[0]->on_read (undef);
251	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
252	}
253	});
254	}
255
256	=item B<readlines ($callback)>
257
258	=item B<readlines ($sep, $callback)>
259
260	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
261	if C<$sep> is not provided. C<$sep> will be used as part of a regex, so it can be
262	a regex itself and won't be quoted!
263
264	The C<$callback> will be called when at least one
265	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
266	object itself and the rest of the arguments will be the read lines.
267
268	NOTE: This method will override any callbacks installed via the C<on_read> method.
269
270	=cut
271
272	sub readlines {
273	my ($self, $NL, $cb) = @_;
274
275	if (ref $NL) {
276	$cb = $NL;
277	$NL = "\n";
278	}
279
280	$self->{on_readline} = $cb;
281
282	$self->on_read (sub {
283	my @lines;
284	push @lines, $1 while $_[0]->{rbuf} =~ s/(.*)$NL//;
285	$self->{on_readline}->($_[0], @lines);
286	});
287	}
288
289	=item B<write ($data)>
290
291	=item B<write ($callback)>
292
293	=item B<write ($data, $callback)>
294
295	This method will write C<$data> to the filehandle and call the C<$callback>
296	afterwards. If only C<$callback> is provided it will be called when the
297	write buffer becomes empty the next time (or immediately if it already is empty).
298
299	=cut
300
301	sub write {
302	my ($self, $data, $cb) = @_;
303	if (ref $data) { $cb = $data; undef $data }
304	push @{$self->{write_bufs}}, [$data, $cb];
305	$self->_check_writer;
306	}
307
308	sub _check_writer {
309	my ($self) = @_;
310
311	if ($self->{write_w}) {
312	unless ($self->{write_cb}) {
313	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
314	my $wba = shift @{$self->{write_bufs}};
315	$self->{wbuf} .= $wba->[0];	1829	$self->{_eof} = 1;
316	}	1830	}
317	}	1831	}
318	return;	1832
		1833	$self->{_tls_rbuf} .= $tmp;
		1834	$self->_drain_rbuf;
		1835	$self->{tls} or return; # tls session might have gone away in callback
		1836	}
		1837
		1838	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1839	return $self->_tls_error ($tmp)
		1840	if $tmp != $ERROR_WANT_READ
		1841	&& ($tmp != $ERROR_SYSCALL || $!);
		1842
		1843	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1844	$self->{wbuf} .= $tmp;
		1845	$self->_drain_wbuf;
		1846	$self->{tls} or return; # tls session might have gone away in callback
		1847	}
		1848
		1849	$self->{_on_starttls}
		1850	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1851	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1852	}
		1853
		1854	=item $handle->starttls ($tls[, $tls_ctx])
		1855
		1856	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1857	object is created, you can also do that at a later time by calling
		1858	C<starttls>.
		1859
		1860	Starting TLS is currently an asynchronous operation - when you push some
		1861	write data and then call C<< ->starttls >> then TLS negotiation will start
		1862	immediately, after which the queued write data is then sent.
		1863
		1864	The first argument is the same as the C<tls> constructor argument (either
		1865	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1866
		1867	The second argument is the optional C<AnyEvent::TLS> object that is used
		1868	when AnyEvent::Handle has to create its own TLS connection object, or
		1869	a hash reference with C<< key => value >> pairs that will be used to
		1870	construct a new context.
		1871
		1872	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1873	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1874	changed to your liking. Note that the handshake might have already started
		1875	when this function returns.
		1876
		1877	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1878	handshakes on the same stream. It is best to not attempt to use the
		1879	stream after stopping TLS.
		1880
		1881	This method may invoke callbacks (and therefore the handle might be
		1882	destroyed after it returns).
		1883
		1884	=cut
		1885
		1886	our %TLS_CACHE; #TODO not yet documented, should we?
		1887
		1888	sub starttls {
		1889	my ($self, $tls, $ctx) = @_;
		1890
		1891	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1892	if $self->{tls};
		1893
		1894	$self->{tls} = $tls;
		1895	$self->{tls_ctx} = $ctx if @_ > 2;
		1896
		1897	return unless $self->{fh};
		1898
		1899	require Net::SSLeay;
		1900
		1901	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1902	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1903
		1904	$tls = delete $self->{tls};
		1905	$ctx = $self->{tls_ctx};
		1906
		1907	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1908
		1909	if ("HASH" eq ref $ctx) {
		1910	require AnyEvent::TLS;
		1911
		1912	if ($ctx->{cache}) {
		1913	my $key = $ctx+0;
		1914	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1915	} else {
		1916	$ctx = new AnyEvent::TLS %$ctx;
		1917	}
		1918	}
319	}	1919
		1920	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1921	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
320		1922
321	my $wba = shift @{$self->{write_bufs}}	1923	# basically, this is deep magic (because SSL_read should have the same issues)
322	or return;	1924	# but the openssl maintainers basically said: "trust us, it just works".
		1925	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1926	# and mismaintained ssleay-module doesn't even offer them).
		1927	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1928	#
		1929	# in short: this is a mess.
		1930	#
		1931	# note that we do not try to keep the length constant between writes as we are required to do.
		1932	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1933	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1934	# have identity issues in that area.
		1935	# Net::SSLeay::CTX_set_mode ($ssl,
		1936	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1937	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1938	Net::SSLeay::CTX_set_mode ($tls, 1|2);
323		1939
324	unless (defined $wba->[0]) {	1940	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
325	$wba->[1]->($self) if $wba->[1];	1941	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
326	$self->_check_writer;	1942
327	return;	1943	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1944
		1945	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1946
		1947	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1948	if $self->{on_starttls};
		1949
		1950	&_dotls; # need to trigger the initial handshake
		1951	$self->start_read; # make sure we actually do read
		1952	}
		1953
		1954	=item $handle->stoptls
		1955
		1956	Shuts down the SSL connection - this makes a proper EOF handshake by
		1957	sending a close notify to the other side, but since OpenSSL doesn't
		1958	support non-blocking shut downs, it is not guaranteed that you can re-use
		1959	the stream afterwards.
		1960
		1961	This method may invoke callbacks (and therefore the handle might be
		1962	destroyed after it returns).
		1963
		1964	=cut
		1965
		1966	sub stoptls {
		1967	my ($self) = @_;
		1968
		1969	if ($self->{tls} && $self->{fh}) {
		1970	Net::SSLeay::shutdown ($self->{tls});
		1971
		1972	&_dotls;
		1973
		1974	# # we don't give a shit. no, we do, but we can't. no...#d#
		1975	# # we, we... have to use openssl :/#d#
		1976	# &_freetls;#d#
		1977	}
		1978	}
		1979
		1980	sub _freetls {
		1981	my ($self) = @_;
		1982
		1983	return unless $self->{tls};
		1984
		1985	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1986	if $self->{tls} > 0;
328	}	1987
		1988	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1989	}
329		1990
330	$self->{wbuf} = $wba->[0];	1991	sub DESTROY {
331	$self->{write_cb} = $wba->[1];	1992	my ($self) = @_;
332		1993
333	$self->{write_w} =	1994	&_freetls;
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1995
		1996	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1997
		1998	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1999	my $fh = delete $self->{fh};
		2000	my $wbuf = delete $self->{wbuf};
		2001
		2002	my @linger;
		2003
		2004	push @linger, AE::io $fh, 1, sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	2005	my $len = syswrite $fh, $wbuf, length $wbuf;
336		2006
337	if (not defined $l) {	2007	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	2008	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	2009	} else {
343	substr $self->{wbuf}, 0, $l, '';	2010	@linger = (); # end
344
345	if (length ($self->{wbuf}) == 0) {
346	$self->{write_cb}->($self) if $self->{write_cb};
347
348	delete $self->{write_w};
349	delete $self->{wbuf};
350	delete $self->{write_cb};
351
352	$self->_check_writer;
353	}
354	}	2011	}
355	});	2012	};
		2013	push @linger, AE::timer $linger, 0, sub {
		2014	@linger = ();
		2015	};
		2016	}
		2017	}
		2018
		2019	=item $handle->destroy
		2020
		2021	Shuts down the handle object as much as possible - this call ensures that
		2022	no further callbacks will be invoked and as many resources as possible
		2023	will be freed. Any method you will call on the handle object after
		2024	destroying it in this way will be silently ignored (and it will return the
		2025	empty list).
		2026
		2027	Normally, you can just "forget" any references to an AnyEvent::Handle
		2028	object and it will simply shut down. This works in fatal error and EOF
		2029	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2030	callback, so when you want to destroy the AnyEvent::Handle object from
		2031	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2032	that case.
		2033
		2034	Destroying the handle object in this way has the advantage that callbacks
		2035	will be removed as well, so if those are the only reference holders (as
		2036	is common), then one doesn't need to do anything special to break any
		2037	reference cycles.
		2038
		2039	The handle might still linger in the background and write out remaining
		2040	data, as specified by the C<linger> option, however.
		2041
		2042	=cut
		2043
		2044	sub destroy {
		2045	my ($self) = @_;
		2046
		2047	$self->DESTROY;
		2048	%$self = ();
		2049	bless $self, "AnyEvent::Handle::destroyed";
		2050	}
		2051
		2052	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2053	#nop
		2054	}
		2055
		2056	=item $handle->destroyed
		2057
		2058	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2059	->destroy >>, true otherwise.
		2060
		2061	Can be useful to decide whether the handle is still valid after some
		2062	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2063	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2064	can destroy the handle, so work can be avoided by checking sometimes:
		2065
		2066	$hdl->starttls ("accept");
		2067	return if $hdl->destroyed;
		2068	$hdl->push_write (...
		2069
		2070	Note that the call to C<push_write> will silently be ignored if the handle
		2071	has been destroyed, so often you can just ignore the possibility of the
		2072	handle being destroyed.
		2073
		2074	=cut
		2075
		2076	sub destroyed { 0 }
		2077	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2078
		2079	=item AnyEvent::Handle::TLS_CTX
		2080
		2081	This function creates and returns the AnyEvent::TLS object used by default
		2082	for TLS mode.
		2083
		2084	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2085
		2086	=cut
		2087
		2088	our $TLS_CTX;
		2089
		2090	sub TLS_CTX() {
		2091	$TLS_CTX ||= do {
		2092	require AnyEvent::TLS;
		2093
		2094	new AnyEvent::TLS
		2095	}
356	}	2096	}
357		2097
358	=back	2098	=back
359		2099
		2100
		2101	=head1 NONFREQUENTLY ASKED QUESTIONS
		2102
		2103	=over 4
		2104
		2105	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2106	still get further invocations!
		2107
		2108	That's because AnyEvent::Handle keeps a reference to itself when handling
		2109	read or write callbacks.
		2110
		2111	It is only safe to "forget" the reference inside EOF or error callbacks,
		2112	from within all other callbacks, you need to explicitly call the C<<
		2113	->destroy >> method.
		2114
		2115	=item I get different callback invocations in TLS mode/Why can't I pause
		2116	reading?
		2117
		2118	Unlike, say, TCP, TLS connections do not consist of two independent
		2119	communication channels, one for each direction. Or put differently, the
		2120	read and write directions are not independent of each other: you cannot
		2121	write data unless you are also prepared to read, and vice versa.
		2122
		2123	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2124	callback invocations when you are not expecting any read data - the reason
		2125	is that AnyEvent::Handle always reads in TLS mode.
		2126
		2127	During the connection, you have to make sure that you always have a
		2128	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2129	connection (or when you no longer want to use it) you can call the
		2130	C<destroy> method.
		2131
		2132	=item How do I read data until the other side closes the connection?
		2133
		2134	If you just want to read your data into a perl scalar, the easiest way
		2135	to achieve this is by setting an C<on_read> callback that does nothing,
		2136	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2137	will be in C<$_[0]{rbuf}>:
		2138
		2139	$handle->on_read (sub { });
		2140	$handle->on_eof (undef);
		2141	$handle->on_error (sub {
		2142	my $data = delete $_[0]{rbuf};
		2143	});
		2144
		2145	The reason to use C<on_error> is that TCP connections, due to latencies
		2146	and packets loss, might get closed quite violently with an error, when in
		2147	fact all data has been received.
		2148
		2149	It is usually better to use acknowledgements when transferring data,
		2150	to make sure the other side hasn't just died and you got the data
		2151	intact. This is also one reason why so many internet protocols have an
		2152	explicit QUIT command.
		2153
		2154	=item I don't want to destroy the handle too early - how do I wait until
		2155	all data has been written?
		2156
		2157	After writing your last bits of data, set the C<on_drain> callback
		2158	and destroy the handle in there - with the default setting of
		2159	C<low_water_mark> this will be called precisely when all data has been
		2160	written to the socket:
		2161
		2162	$handle->push_write (...);
		2163	$handle->on_drain (sub {
		2164	warn "all data submitted to the kernel\n";
		2165	undef $handle;
		2166	});
		2167
		2168	If you just want to queue some data and then signal EOF to the other side,
		2169	consider using C<< ->push_shutdown >> instead.
		2170
		2171	=item I want to contact a TLS/SSL server, I don't care about security.
		2172
		2173	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2174	connect to it and then create the AnyEvent::Handle with the C<tls>
		2175	parameter:
		2176
		2177	tcp_connect $host, $port, sub {
		2178	my ($fh) = @_;
		2179
		2180	my $handle = new AnyEvent::Handle
		2181	fh => $fh,
		2182	tls => "connect",
		2183	on_error => sub { ... };
		2184
		2185	$handle->push_write (...);
		2186	};
		2187
		2188	=item I want to contact a TLS/SSL server, I do care about security.
		2189
		2190	Then you should additionally enable certificate verification, including
		2191	peername verification, if the protocol you use supports it (see
		2192	L<AnyEvent::TLS>, C<verify_peername>).
		2193
		2194	E.g. for HTTPS:
		2195
		2196	tcp_connect $host, $port, sub {
		2197	my ($fh) = @_;
		2198
		2199	my $handle = new AnyEvent::Handle
		2200	fh => $fh,
		2201	peername => $host,
		2202	tls => "connect",
		2203	tls_ctx => { verify => 1, verify_peername => "https" },
		2204	...
		2205
		2206	Note that you must specify the hostname you connected to (or whatever
		2207	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2208	peername verification will be done.
		2209
		2210	The above will use the system-dependent default set of trusted CA
		2211	certificates. If you want to check against a specific CA, add the
		2212	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2213
		2214	tls_ctx => {
		2215	verify => 1,
		2216	verify_peername => "https",
		2217	ca_file => "my-ca-cert.pem",
		2218	},
		2219
		2220	=item I want to create a TLS/SSL server, how do I do that?
		2221
		2222	Well, you first need to get a server certificate and key. You have
		2223	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2224	self-signed certificate (cheap. check the search engine of your choice,
		2225	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2226	nice program for that purpose).
		2227
		2228	Then create a file with your private key (in PEM format, see
		2229	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2230	file should then look like this:
		2231
		2232	-----BEGIN RSA PRIVATE KEY-----
		2233	...header data
		2234	... lots of base64'y-stuff
		2235	-----END RSA PRIVATE KEY-----
		2236
		2237	-----BEGIN CERTIFICATE-----
		2238	... lots of base64'y-stuff
		2239	-----END CERTIFICATE-----
		2240
		2241	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2242	specify this file as C<cert_file>:
		2243
		2244	tcp_server undef, $port, sub {
		2245	my ($fh) = @_;
		2246
		2247	my $handle = new AnyEvent::Handle
		2248	fh => $fh,
		2249	tls => "accept",
		2250	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2251	...
		2252
		2253	When you have intermediate CA certificates that your clients might not
		2254	know about, just append them to the C<cert_file>.
		2255
		2256	=back
		2257
		2258
		2259	=head1 SUBCLASSING AnyEvent::Handle
		2260
		2261	In many cases, you might want to subclass AnyEvent::Handle.
		2262
		2263	To make this easier, a given version of AnyEvent::Handle uses these
		2264	conventions:
		2265
		2266	=over 4
		2267
		2268	=item * all constructor arguments become object members.
		2269
		2270	At least initially, when you pass a C<tls>-argument to the constructor it
		2271	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2272	mutated later on (for example C<tls> will hold the TLS connection object).
		2273
		2274	=item * other object member names are prefixed with an C<_>.
		2275
		2276	All object members not explicitly documented (internal use) are prefixed
		2277	with an underscore character, so the remaining non-C<_>-namespace is free
		2278	for use for subclasses.
		2279
		2280	=item * all members not documented here and not prefixed with an underscore
		2281	are free to use in subclasses.
		2282
		2283	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2284	member variables, but that's just life. At least it is documented.
		2285
		2286	=back
		2287
360	=head1 AUTHOR	2288	=head1 AUTHOR
361		2289
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	2290	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363
364	=head1 BUGS
365
366	Please report any bugs or feature requests to
367	C<bug-io-anyevent at rt.cpan.org>, or through the web interface at
368	L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=IO-AnyEvent>.
369	I will be notified, and then you'll automatically be notified of progress on
370	your bug as I make changes.
371
372	=head1 SUPPORT
373
374	You can find documentation for this module with the perldoc command.
375
376	perldoc AnyEvent::Handle
377
378	You can also look for information at:
379
380	=over 4
381
382	=item * AnnoCPAN: Annotated CPAN documentation
383
384	L<http://annocpan.org/dist/IO-AnyEvent>
385
386	=item * CPAN Ratings
387
388	L<http://cpanratings.perl.org/d/IO-AnyEvent>
389
390	=item * RT: CPAN's request tracker
391
392	L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=IO-AnyEvent>
393
394	=item * Search CPAN
395
396	L<http://search.cpan.org/dist/IO-AnyEvent>
397
398	=back
399
400	=head1 ACKNOWLEDGEMENTS
401
402	=head1 COPYRIGHT & LICENSE
403
404	Copyright 2008 Robin Redeker, all rights reserved.
405
406	This program is free software; you can redistribute it and/or modify it
407	under the same terms as Perl itself.
408		2291
409	=cut	2292	=cut
410		2293
411	1; # End of AnyEvent::Handle	2294	1; # End of AnyEvent::Handle

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