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Revision 1.4 by elmex, Sun Apr 27 20:20:20 2008 UTC vs.
Revision 1.203 by root, Sat Oct 16 03:22:10 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	sub MAX_READ_SIZE() { 131072 }
		81
		82	=head1 METHODS
		83
		84	=over 4
		85
		86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
		87
		88	The constructor supports these arguments (all as C<< key => value >> pairs).
		89
		90	=over 4
		91
		92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
		93
		94	The filehandle this L<AnyEvent::Handle> object will operate on.
		95	NOTE: The filehandle will be set to non-blocking mode (using
		96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
		98
		99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		100
		101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
		104
		105	You have to specify either this parameter, or C<fh>, above.
		106
		107	It is possible to push requests on the read and write queues, and modify
		108	properties of the stream, even while AnyEvent::Handle is connecting.
		109
		110	When this parameter is specified, then the C<on_prepare>,
		111	C<on_connect_error> and C<on_connect> callbacks will be called under the
		112	appropriate circumstances:
		113
		114	=over 4
		115
		116	=item on_prepare => $cb->($handle)
		117
		118	This (rarely used) callback is called before a new connection is
		119	attempted, but after the file handle has been created. It could be used to
		120	prepare the file handle with parameters required for the actual connect
		121	(as opposed to settings that can be changed when the connection is already
		122	established).
		123
		124	The return value of this callback should be the connect timeout value in
		125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
		126	default timeout is to be used).
		127
		128	=item on_connect => $cb->($handle, $host, $port, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback.
		134
		135	If, for some reason, the handle is not acceptable, calling C<$retry>
		136	will continue with the next connection target (in case of multi-homed
		137	hosts or SRV records there can be multiple connection endpoints). At the
		138	time it is called the read and write queues, eof status, tls status and
		139	similar properties of the handle will have been reset.
		140
		141	In most cases, you should ignore the C<$retry> parameter.
		142
		143	=item on_connect_error => $cb->($handle, $message)
		144
		145	This callback is called when the connection could not be
		146	established. C<$!> will contain the relevant error code, and C<$message> a
		147	message describing it (usually the same as C<"$!">).
		148
		149	If this callback isn't specified, then C<on_error> will be called with a
		150	fatal error instead.
		151
		152	=back
		153
		154	=item on_error => $cb->($handle, $fatal, $message)
		155
		156	This is the error callback, which is called when, well, some error
		157	occured, such as not being able to resolve the hostname, failure to
		158	connect, or a read error.
		159
		160	Some errors are fatal (which is indicated by C<$fatal> being true). On
		161	fatal errors the handle object will be destroyed (by a call to C<< ->
		162	destroy >>) after invoking the error callback (which means you are free to
		163	examine the handle object). Examples of fatal errors are an EOF condition
		164	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
		173	Non-fatal errors can be retried by returning, but it is recommended
		174	to simply ignore this parameter and instead abondon the handle object
		175	when this callback is invoked. Examples of non-fatal errors are timeouts
		176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		177
		178	On entry to the callback, the value of C<$!> contains the operating
		179	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		180	C<EPROTO>).
		181
		182	While not mandatory, it is I<highly> recommended to set this callback, as
		183	you will not be notified of errors otherwise. The default just calls
		184	C<croak>.
		185
		186	=item on_read => $cb->($handle)
		187
		188	This sets the default read callback, which is called when data arrives
		189	and no read request is in the queue (unlike read queue callbacks, this
		190	callback will only be called when at least one octet of data is in the
		191	read buffer).
		192
		193	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
		201	When an EOF condition is detected, AnyEvent::Handle will first try to
		202	feed all the remaining data to the queued callbacks and C<on_read> before
		203	calling the C<on_eof> callback. If no progress can be made, then a fatal
		204	error will be raised (with C<$!> set to C<EPIPE>).
		205
		206	Note that, unlike requests in the read queue, an C<on_read> callback
		207	doesn't mean you I<require> some data: if there is an EOF and there
		208	are outstanding read requests then an error will be flagged. With an
		209	C<on_read> callback, the C<on_eof> callback will be invoked.
		210
		211	=item on_eof => $cb->($handle)
		212
		213	Set the callback to be called when an end-of-file condition is detected,
		214	i.e. in the case of a socket, when the other side has closed the
		215	connection cleanly, and there are no outstanding read requests in the
		216	queue (if there are read requests, then an EOF counts as an unexpected
		217	connection close and will be flagged as an error).
		218
		219	For sockets, this just means that the other side has stopped sending data,
		220	you can still try to write data, and, in fact, one can return from the EOF
		221	callback and continue writing data, as only the read part has been shut
		222	down.
		223
		224	If an EOF condition has been detected but no C<on_eof> callback has been
		225	set, then a fatal error will be raised with C<$!> set to <0>.
		226
		227	=item on_drain => $cb->($handle)
		228
		229	This sets the callback that is called when the write buffer becomes empty
		230	(or immediately if the buffer is empty already).
		231
		232	To append to the write buffer, use the C<< ->push_write >> method.
		233
		234	This callback is useful when you don't want to put all of your write data
		235	into the queue at once, for example, when you want to write the contents
		236	of some file to the socket you might not want to read the whole file into
		237	memory and push it into the queue, but instead only read more data from
		238	the file when the write queue becomes empty.
		239
		240	=item timeout => $fractional_seconds
		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
		246	If non-zero, then these enables an "inactivity" timeout: whenever this
		247	many seconds pass without a successful read or write on the underlying
		248	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		249	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		250	error will be raised).
		251
		252	There are three variants of the timeouts that work independently
		253	of each other, for both read and write, just read, and just write:
		254	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		255	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		256	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		257
		258	Note that timeout processing is active even when you do not have
		259	any outstanding read or write requests: If you plan to keep the connection
		260	idle then you should disable the timeout temporarily or ignore the timeout
		261	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		262	restart the timeout.
		263
		264	Zero (the default) disables this timeout.
		265
		266	=item on_timeout => $cb->($handle)
		267
		268	Called whenever the inactivity timeout passes. If you return from this
		269	callback, then the timeout will be reset as if some activity had happened,
		270	so this condition is not fatal in any way.
		271
		272	=item rbuf_max => <bytes>
		273
		274	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		275	when the read buffer ever (strictly) exceeds this size. This is useful to
		276	avoid some forms of denial-of-service attacks.
		277
		278	For example, a server accepting connections from untrusted sources should
		279	be configured to accept only so-and-so much data that it cannot act on
		280	(for example, when expecting a line, an attacker could send an unlimited
		281	amount of data without a callback ever being called as long as the line
		282	isn't finished).
		283
		284	=item autocork => <boolean>
		285
		286	When disabled (the default), C<push_write> will try to immediately
		287	write the data to the handle if possible. This avoids having to register
		288	a write watcher and wait for the next event loop iteration, but can
		289	be inefficient if you write multiple small chunks (on the wire, this
		290	disadvantage is usually avoided by your kernel's nagle algorithm, see
		291	C<no_delay>, but this option can save costly syscalls).
		292
		293	When enabled, writes will always be queued till the next event loop
		294	iteration. This is efficient when you do many small writes per iteration,
		295	but less efficient when you do a single write only per iteration (or when
		296	the write buffer often is full). It also increases write latency.
		297
		298	=item no_delay => <boolean>
		299
		300	When doing small writes on sockets, your operating system kernel might
		301	wait a bit for more data before actually sending it out. This is called
		302	the Nagle algorithm, and usually it is beneficial.
		303
		304	In some situations you want as low a delay as possible, which can be
		305	accomplishd by setting this option to a true value.
		306
		307	The default is your operating system's default behaviour (most likely
		308	enabled). This option explicitly enables or disables it, if possible.
		309
		310	=item keepalive => <boolean>
		311
		312	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		313	normally, TCP connections have no time-out once established, so TCP
		314	connections, once established, can stay alive forever even when the other
		315	side has long gone. TCP keepalives are a cheap way to take down long-lived
		316	TCP connections when the other side becomes unreachable. While the default
		317	is OS-dependent, TCP keepalives usually kick in after around two hours,
		318	and, if the other side doesn't reply, take down the TCP connection some 10
		319	to 15 minutes later.
		320
		321	It is harmless to specify this option for file handles that do not support
		322	keepalives, and enabling it on connections that are potentially long-lived
		323	is usually a good idea.
		324
		325	=item oobinline => <boolean>
		326
		327	BSD majorly fucked up the implementation of TCP urgent data. The result
		328	is that almost no OS implements TCP according to the specs, and every OS
		329	implements it slightly differently.
		330
		331	If you want to handle TCP urgent data, then setting this flag (the default
		332	is enabled) gives you the most portable way of getting urgent data, by
		333	putting it into the stream.
		334
		335	Since BSD emulation of OOB data on top of TCP's urgent data can have
		336	security implications, AnyEvent::Handle sets this flag automatically
		337	unless explicitly specified. Note that setting this flag after
		338	establishing a connection I<may> be a bit too late (data loss could
		339	already have occured on BSD systems), but at least it will protect you
		340	from most attacks.
		341
		342	=item read_size => <bytes>
		343
		344	The initial read block size, the number of bytes this module will try to
		345	read during each loop iteration. Each handle object will consume at least
		346	this amount of memory for the read buffer as well, so when handling many
		347	connections requirements). See also C<max_read_size>. Default: C<2048>.
		348
		349	=item max_read_size => <bytes>
		350
		351	The maximum read buffer size used by the dynamic adjustment
		352	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		353	one go it will double C<read_size> up to the maximum given by this
		354	option. Default: C<131072> or C<read_size>, whichever is higher.
		355
		356	=item low_water_mark => <bytes>
		357
		358	Sets the number of bytes (default: C<0>) that make up an "empty" write
		359	buffer: If the buffer reaches this size or gets even samller it is
		360	considered empty.
		361
		362	Sometimes it can be beneficial (for performance reasons) to add data to
		363	the write buffer before it is fully drained, but this is a rare case, as
		364	the operating system kernel usually buffers data as well, so the default
		365	is good in almost all cases.
		366
		367	=item linger => <seconds>
		368
		369	If this is non-zero (default: C<3600>), the destructor of the
		370	AnyEvent::Handle object will check whether there is still outstanding
		371	write data and will install a watcher that will write this data to the
		372	socket. No errors will be reported (this mostly matches how the operating
		373	system treats outstanding data at socket close time).
		374
		375	This will not work for partial TLS data that could not be encoded
		376	yet. This data will be lost. Calling the C<stoptls> method in time might
		377	help.
		378
		379	=item peername => $string
		380
		381	A string used to identify the remote site - usually the DNS hostname
		382	(I<not> IDN!) used to create the connection, rarely the IP address.
		383
		384	Apart from being useful in error messages, this string is also used in TLS
		385	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		386	verification will be skipped when C<peername> is not specified or is
		387	C<undef>.
		388
		389	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		390
		391	When this parameter is given, it enables TLS (SSL) mode, that means
		392	AnyEvent will start a TLS handshake as soon as the connection has been
		393	established and will transparently encrypt/decrypt data afterwards.
		394
		395	All TLS protocol errors will be signalled as C<EPROTO>, with an
		396	appropriate error message.
		397
		398	TLS mode requires Net::SSLeay to be installed (it will be loaded
		399	automatically when you try to create a TLS handle): this module doesn't
		400	have a dependency on that module, so if your module requires it, you have
		401	to add the dependency yourself.
		402
		403	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		404	C<accept>, and for the TLS client side of a connection, use C<connect>
		405	mode.
		406
		407	You can also provide your own TLS connection object, but you have
		408	to make sure that you call either C<Net::SSLeay::set_connect_state>
		409	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		410	AnyEvent::Handle. Also, this module will take ownership of this connection
		411	object.
		412
		413	At some future point, AnyEvent::Handle might switch to another TLS
		414	implementation, then the option to use your own session object will go
		415	away.
		416
		417	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		418	passing in the wrong integer will lead to certain crash. This most often
		419	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		420	segmentation fault.
		421
		422	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
		423
		424	=item tls_ctx => $anyevent_tls
		425
		426	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		427	(unless a connection object was specified directly). If this parameter is
		428	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		429
		430	Instead of an object, you can also specify a hash reference with C<< key
		431	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		432	new TLS context object.
		433
		434	=item on_starttls => $cb->($handle, $success[, $error_message])
		435
		436	This callback will be invoked when the TLS/SSL handshake has finished. If
		437	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		438	(C<on_stoptls> will not be called in this case).
		439
		440	The session in C<< $handle->{tls} >> can still be examined in this
		441	callback, even when the handshake was not successful.
		442
		443	TLS handshake failures will not cause C<on_error> to be invoked when this
		444	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		445
		446	Without this callback, handshake failures lead to C<on_error> being
		447	called as usual.
		448
		449	Note that you cannot just call C<starttls> again in this callback. If you
		450	need to do that, start an zero-second timer instead whose callback can
		451	then call C<< ->starttls >> again.
		452
		453	=item on_stoptls => $cb->($handle)
		454
		455	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		456	set, then it will be invoked after freeing the TLS session. If it is not,
		457	then a TLS shutdown condition will be treated like a normal EOF condition
		458	on the handle.
		459
		460	The session in C<< $handle->{tls} >> can still be examined in this
		461	callback.
		462
		463	This callback will only be called on TLS shutdowns, not when the
		464	underlying handle signals EOF.
		465
		466	=item json => JSON or JSON::XS object
		467
		468	This is the json coder object used by the C<json> read and write types.
		469
		470	If you don't supply it, then AnyEvent::Handle will create and use a
		471	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		472	texts.
		473
		474	Note that you are responsible to depend on the JSON module if you want to
		475	use this functionality, as AnyEvent does not have a dependency itself.
		476
		477	=back
		478
		479	=cut
		480
		481	sub new {
		482	my $class = shift;
		483	my $self = bless { @_ }, $class;
		484
		485	if ($self->{fh}) {
		486	$self->_start;
		487	return unless $self->{fh}; # could be gone by now
		488
		489	} elsif ($self->{connect}) {
		490	require AnyEvent::Socket;
		491
		492	$self->{peername} = $self->{connect}[0]
		493	unless exists $self->{peername};
		494
		495	$self->{_skip_drain_rbuf} = 1;
		496
		497	{
		498	Scalar::Util::weaken (my $self = $self);
		499
		500	$self->{_connect} =
		501	AnyEvent::Socket::tcp_connect (
		502	$self->{connect}[0],
		503	$self->{connect}[1],
		504	sub {
		505	my ($fh, $host, $port, $retry) = @_;
		506
		507	if ($fh) {
		508	$self->{fh} = $fh;
		509
		510	delete $self->{_skip_drain_rbuf};
		511	$self->_start;
		512
		513	$self->{on_connect}
		514	and $self->{on_connect}($self, $host, $port, sub {
		515	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		516	$self->{_skip_drain_rbuf} = 1;
		517	&$retry;
		518	});
		519
		520	} else {
		521	if ($self->{on_connect_error}) {
		522	$self->{on_connect_error}($self, "$!");
		523	$self->destroy;
		524	} else {
		525	$self->_error ($!, 1);
		526	}
		527	}
		528	},
		529	sub {
		530	local $self->{fh} = $_[0];
		531
		532	$self->{on_prepare}
		533	? $self->{on_prepare}->($self)
		534	: ()
		535	}
		536	);
		537	}
		538
		539	} else {
		540	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		541	}
		542
		543	$self
		544	}
		545
		546	sub _start {
		547	my ($self) = @_;
		548
		549	# too many clueless people try to use udp and similar sockets
		550	# with AnyEvent::Handle, do them a favour.
		551	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		552	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		553	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
		554
		555	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		556
		557	$self->{_activity} =
		558	$self->{_ractivity} =
		559	$self->{_wactivity} = AE::now;
		560
		561	$self->{read_size} ||= 2048;
		562	$self->{max_read_size} = $self->{read_size}
		563	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		564
		565	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		566	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		567	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		568
		569	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		570	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		571
		572	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		573
		574	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		575	if $self->{tls};
		576
		577	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
		578
		579	$self->start_read
		580	if $self->{on_read} || @{ $self->{_queue} };
		581
		582	$self->_drain_wbuf;
		583	}
		584
		585	sub _error {
		586	my ($self, $errno, $fatal, $message) = @_;
		587
		588	$! = $errno;
		589	$message ||= "$!";
		590
		591	if ($self->{on_error}) {
		592	$self->{on_error}($self, $fatal, $message);
		593	$self->destroy if $fatal;
		594	} elsif ($self->{fh} || $self->{connect}) {
		595	$self->destroy;
		596	Carp::croak "AnyEvent::Handle uncaught error: $message";
		597	}
		598	}
		599
		600	=item $fh = $handle->fh
		601
		602	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		603
		604	=cut
		605
		606	sub fh { $_[0]{fh} }
		607
		608	=item $handle->on_error ($cb)
		609
		610	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		611
		612	=cut
		613
		614	sub on_error {
		615	$_[0]{on_error} = $_[1];
		616	}
		617
		618	=item $handle->on_eof ($cb)
		619
		620	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		621
		622	=cut
		623
		624	sub on_eof {
		625	$_[0]{on_eof} = $_[1];
		626	}
		627
		628	=item $handle->on_timeout ($cb)
		629
		630	=item $handle->on_rtimeout ($cb)
		631
		632	=item $handle->on_wtimeout ($cb)
		633
		634	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		635	callback, or disables the callback (but not the timeout) if C<$cb> =
		636	C<undef>. See the C<timeout> constructor argument and method.
		637
		638	=cut
		639
		640	# see below
		641
		642	=item $handle->autocork ($boolean)
		643
		644	Enables or disables the current autocork behaviour (see C<autocork>
		645	constructor argument). Changes will only take effect on the next write.
		646
		647	=cut
		648
		649	sub autocork {
		650	$_[0]{autocork} = $_[1];
		651	}
		652
		653	=item $handle->no_delay ($boolean)
		654
		655	Enables or disables the C<no_delay> setting (see constructor argument of
		656	the same name for details).
		657
		658	=cut
		659
		660	sub no_delay {
		661	$_[0]{no_delay} = $_[1];
		662
		663	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		664	if $_[0]{fh};
		665	}
		666
		667	=item $handle->keepalive ($boolean)
		668
		669	Enables or disables the C<keepalive> setting (see constructor argument of
		670	the same name for details).
		671
		672	=cut
		673
		674	sub keepalive {
		675	$_[0]{keepalive} = $_[1];
		676
		677	eval {
		678	local $SIG{__DIE__};
		679	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		680	if $_[0]{fh};
		681	};
		682	}
		683
		684	=item $handle->oobinline ($boolean)
		685
		686	Enables or disables the C<oobinline> setting (see constructor argument of
		687	the same name for details).
		688
		689	=cut
		690
		691	sub oobinline {
		692	$_[0]{oobinline} = $_[1];
		693
		694	eval {
		695	local $SIG{__DIE__};
		696	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		697	if $_[0]{fh};
		698	};
		699	}
		700
		701	=item $handle->keepalive ($boolean)
		702
		703	Enables or disables the C<keepalive> setting (see constructor argument of
		704	the same name for details).
		705
		706	=cut
		707
		708	sub keepalive {
		709	$_[0]{keepalive} = $_[1];
		710
		711	eval {
		712	local $SIG{__DIE__};
		713	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		714	if $_[0]{fh};
		715	};
		716	}
		717
		718	=item $handle->on_starttls ($cb)
		719
		720	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		721
		722	=cut
		723
		724	sub on_starttls {
		725	$_[0]{on_starttls} = $_[1];
		726	}
		727
		728	=item $handle->on_stoptls ($cb)
		729
		730	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		731
		732	=cut
		733
		734	sub on_stoptls {
		735	$_[0]{on_stoptls} = $_[1];
		736	}
		737
		738	=item $handle->rbuf_max ($max_octets)
		739
		740	Configures the C<rbuf_max> setting (C<undef> disables it).
		741
		742	=cut
		743
		744	sub rbuf_max {
		745	$_[0]{rbuf_max} = $_[1];
		746	}
		747
		748	#############################################################################
		749
		750	=item $handle->timeout ($seconds)
		751
		752	=item $handle->rtimeout ($seconds)
		753
		754	=item $handle->wtimeout ($seconds)
		755
		756	Configures (or disables) the inactivity timeout.
		757
		758	=item $handle->timeout_reset
		759
		760	=item $handle->rtimeout_reset
		761
		762	=item $handle->wtimeout_reset
		763
		764	Reset the activity timeout, as if data was received or sent.
		765
		766	These methods are cheap to call.
		767
		768	=cut
		769
		770	for my $dir ("", "r", "w") {
		771	my $timeout = "${dir}timeout";
		772	my $tw = "_${dir}tw";
		773	my $on_timeout = "on_${dir}timeout";
		774	my $activity = "_${dir}activity";
		775	my $cb;
		776
		777	*$on_timeout = sub {
		778	$_[0]{$on_timeout} = $_[1];
		779	};
		780
		781	*$timeout = sub {
		782	my ($self, $new_value) = @_;
		783
		784	$new_value >= 0
		785	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		786
		787	$self->{$timeout} = $new_value;
		788	delete $self->{$tw}; &$cb;
		789	};
		790
		791	*{"${dir}timeout_reset"} = sub {
		792	$_[0]{$activity} = AE::now;
		793	};
		794
		795	# main workhorse:
		796	# reset the timeout watcher, as neccessary
		797	# also check for time-outs
		798	$cb = sub {
		799	my ($self) = @_;
		800
		801	if ($self->{$timeout} && $self->{fh}) {
		802	my $NOW = AE::now;
		803
		804	# when would the timeout trigger?
		805	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		806
		807	# now or in the past already?
		808	if ($after <= 0) {
		809	$self->{$activity} = $NOW;
		810
		811	if ($self->{$on_timeout}) {
		812	$self->{$on_timeout}($self);
		813	} else {
		814	$self->_error (Errno::ETIMEDOUT);
		815	}
		816
		817	# callback could have changed timeout value, optimise
		818	return unless $self->{$timeout};
		819
		820	# calculate new after
		821	$after = $self->{$timeout};
		822	}
		823
		824	Scalar::Util::weaken $self;
		825	return unless $self; # ->error could have destroyed $self
		826
		827	$self->{$tw} ||= AE::timer $after, 0, sub {
		828	delete $self->{$tw};
		829	$cb->($self);
36	chomp;	830	};
37	print "Line: $_";	831	} else {
		832	delete $self->{$tw};
		833	}
		834	}
		835	}
		836
		837	#############################################################################
		838
		839	=back
		840
		841	=head2 WRITE QUEUE
		842
		843	AnyEvent::Handle manages two queues per handle, one for writing and one
		844	for reading.
		845
		846	The write queue is very simple: you can add data to its end, and
		847	AnyEvent::Handle will automatically try to get rid of it for you.
		848
		849	When data could be written and the write buffer is shorter then the low
		850	water mark, the C<on_drain> callback will be invoked.
		851
		852	=over 4
		853
		854	=item $handle->on_drain ($cb)
		855
		856	Sets the C<on_drain> callback or clears it (see the description of
		857	C<on_drain> in the constructor).
		858
		859	This method may invoke callbacks (and therefore the handle might be
		860	destroyed after it returns).
		861
		862	=cut
		863
		864	sub on_drain {
		865	my ($self, $cb) = @_;
		866
		867	$self->{on_drain} = $cb;
		868
		869	$cb->($self)
		870	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
		871	}
		872
		873	=item $handle->push_write ($data)
		874
		875	Queues the given scalar to be written. You can push as much data as you
		876	want (only limited by the available memory), as C<AnyEvent::Handle>
		877	buffers it independently of the kernel.
		878
		879	This method may invoke callbacks (and therefore the handle might be
		880	destroyed after it returns).
		881
		882	=cut
		883
		884	sub _drain_wbuf {
		885	my ($self) = @_;
		886
		887	if (!$self->{_ww} && length $self->{wbuf}) {
		888
		889	Scalar::Util::weaken $self;
		890
		891	my $cb = sub {
		892	my $len = syswrite $self->{fh}, $self->{wbuf};
		893
		894	if (defined $len) {
		895	substr $self->{wbuf}, 0, $len, "";
		896
		897	$self->{_activity} = $self->{_wactivity} = AE::now;
		898
		899	$self->{on_drain}($self)
		900	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
		901	&& $self->{on_drain};
		902
		903	delete $self->{_ww} unless length $self->{wbuf};
		904	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		905	$self->_error ($!, 1);
		906	}
		907	};
		908
		909	# try to write data immediately
		910	$cb->() unless $self->{autocork};
		911
		912	# if still data left in wbuf, we need to poll
		913	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		914	if length $self->{wbuf};
		915	};
		916	}
		917
		918	our %WH;
		919
		920	# deprecated
		921	sub register_write_type($$) {
		922	$WH{$_[0]} = $_[1];
		923	}
		924
		925	sub push_write {
		926	my $self = shift;
		927
		928	if (@_ > 1) {
		929	my $type = shift;
		930
		931	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		932	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		933	->($self, @_);
		934	}
		935
		936	# we downgrade here to avoid hard-to-track-down bugs,
		937	# and diagnose the problem earlier and better.
		938
		939	if ($self->{tls}) {
		940	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		941	&_dotls ($self) if $self->{fh};
		942	} else {
		943	utf8::downgrade $self->{wbuf} .= $_[0];
		944	$self->_drain_wbuf if $self->{fh};
		945	}
		946	}
		947
		948	=item $handle->push_write (type => @args)
		949
		950	Instead of formatting your data yourself, you can also let this module
		951	do the job by specifying a type and type-specific arguments. You
		952	can also specify the (fully qualified) name of a package, in which
		953	case AnyEvent tries to load the package and then expects to find the
		954	C<anyevent_write_type> function inside (see "custom write types", below).
		955
		956	Predefined types are (if you have ideas for additional types, feel free to
		957	drop by and tell us):
		958
		959	=over 4
		960
		961	=item netstring => $string
		962
		963	Formats the given value as netstring
		964	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		965
		966	=cut
		967
		968	register_write_type netstring => sub {
		969	my ($self, $string) = @_;
		970
		971	(length $string) . ":$string,"
		972	};
		973
		974	=item packstring => $format, $data
		975
		976	An octet string prefixed with an encoded length. The encoding C<$format>
		977	uses the same format as a Perl C<pack> format, but must specify a single
		978	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		979	optional C<!>, C<< < >> or C<< > >> modifier).
		980
		981	=cut
		982
		983	register_write_type packstring => sub {
		984	my ($self, $format, $string) = @_;
		985
		986	pack "$format/a*", $string
		987	};
		988
		989	=item json => $array_or_hashref
		990
		991	Encodes the given hash or array reference into a JSON object. Unless you
		992	provide your own JSON object, this means it will be encoded to JSON text
		993	in UTF-8.
		994
		995	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		996	one end of a handle and read them at the other end without using any
		997	additional framing.
		998
		999	The generated JSON text is guaranteed not to contain any newlines: While
		1000	this module doesn't need delimiters after or between JSON texts to be
		1001	able to read them, many other languages depend on that.
		1002
		1003	A simple RPC protocol that interoperates easily with others is to send
		1004	JSON arrays (or objects, although arrays are usually the better choice as
		1005	they mimic how function argument passing works) and a newline after each
		1006	JSON text:
		1007
		1008	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1009	$handle->push_write ("\012");
		1010
		1011	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1012	rely on the fact that the newline will be skipped as leading whitespace:
		1013
		1014	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1015
		1016	Other languages could read single lines terminated by a newline and pass
		1017	this line into their JSON decoder of choice.
		1018
		1019	=cut
		1020
		1021	sub json_coder() {
		1022	eval { require JSON::XS; JSON::XS->new->utf8 }
		1023	|| do { require JSON; JSON->new->utf8 }
		1024	}
		1025
		1026	register_write_type json => sub {
		1027	my ($self, $ref) = @_;
		1028
		1029	my $json = $self->{json} ||= json_coder;
		1030
		1031	$json->encode ($ref)
		1032	};
		1033
		1034	=item storable => $reference
		1035
		1036	Freezes the given reference using L<Storable> and writes it to the
		1037	handle. Uses the C<nfreeze> format.
		1038
		1039	=cut
		1040
		1041	register_write_type storable => sub {
		1042	my ($self, $ref) = @_;
		1043
		1044	require Storable;
		1045
		1046	pack "w/a*", Storable::nfreeze ($ref)
		1047	};
		1048
		1049	=back
		1050
		1051	=item $handle->push_shutdown
		1052
		1053	Sometimes you know you want to close the socket after writing your data
		1054	before it was actually written. One way to do that is to replace your
		1055	C<on_drain> handler by a callback that shuts down the socket (and set
		1056	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1057	replaces the C<on_drain> callback with:
		1058
		1059	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1060
		1061	This simply shuts down the write side and signals an EOF condition to the
		1062	the peer.
		1063
		1064	You can rely on the normal read queue and C<on_eof> handling
		1065	afterwards. This is the cleanest way to close a connection.
		1066
		1067	This method may invoke callbacks (and therefore the handle might be
		1068	destroyed after it returns).
		1069
		1070	=cut
		1071
		1072	sub push_shutdown {
		1073	my ($self) = @_;
		1074
		1075	delete $self->{low_water_mark};
		1076	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1077	}
		1078
		1079	=item custom write types - Package::anyevent_write_type $handle, @args
		1080
		1081	Instead of one of the predefined types, you can also specify the name of
		1082	a package. AnyEvent will try to load the package and then expects to find
		1083	a function named C<anyevent_write_type> inside. If it isn't found, it
		1084	progressively tries to load the parent package until it either finds the
		1085	function (good) or runs out of packages (bad).
		1086
		1087	Whenever the given C<type> is used, C<push_write> will the function with
		1088	the handle object and the remaining arguments.
		1089
		1090	The function is supposed to return a single octet string that will be
		1091	appended to the write buffer, so you cna mentally treat this function as a
		1092	"arguments to on-the-wire-format" converter.
		1093
		1094	Example: implement a custom write type C<join> that joins the remaining
		1095	arguments using the first one.
		1096
		1097	$handle->push_write (My::Type => " ", 1,2,3);
		1098
		1099	# uses the following package, which can be defined in the "My::Type" or in
		1100	# the "My" modules to be auto-loaded, or just about anywhere when the
		1101	# My::Type::anyevent_write_type is defined before invoking it.
		1102
		1103	package My::Type;
		1104
		1105	sub anyevent_write_type {
		1106	my ($handle, $delim, @args) = @_;
		1107
		1108	join $delim, @args
		1109	}
		1110
		1111	=cut
		1112
		1113	#############################################################################
		1114
		1115	=back
		1116
		1117	=head2 READ QUEUE
		1118
		1119	AnyEvent::Handle manages two queues per handle, one for writing and one
		1120	for reading.
		1121
		1122	The read queue is more complex than the write queue. It can be used in two
		1123	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1124	a queue.
		1125
		1126	In the simple case, you just install an C<on_read> callback and whenever
		1127	new data arrives, it will be called. You can then remove some data (if
		1128	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
		1129	leave the data there if you want to accumulate more (e.g. when only a
		1130	partial message has been received so far), or change the read queue with
		1131	e.g. C<push_read>.
		1132
		1133	In the more complex case, you want to queue multiple callbacks. In this
		1134	case, AnyEvent::Handle will call the first queued callback each time new
		1135	data arrives (also the first time it is queued) and remove it when it has
		1136	done its job (see C<push_read>, below).
		1137
		1138	This way you can, for example, push three line-reads, followed by reading
		1139	a chunk of data, and AnyEvent::Handle will execute them in order.
		1140
		1141	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1142	the specified number of bytes which give an XML datagram.
		1143
		1144	# in the default state, expect some header bytes
		1145	$handle->on_read (sub {
		1146	# some data is here, now queue the length-header-read (4 octets)
		1147	shift->unshift_read (chunk => 4, sub {
		1148	# header arrived, decode
		1149	my $len = unpack "N", $_[1];
		1150
		1151	# now read the payload
		1152	shift->unshift_read (chunk => $len, sub {
		1153	my $xml = $_[1];
		1154	# handle xml
		1155	});
		1156	});
		1157	});
		1158
		1159	Example 2: Implement a client for a protocol that replies either with "OK"
		1160	and another line or "ERROR" for the first request that is sent, and 64
		1161	bytes for the second request. Due to the availability of a queue, we can
		1162	just pipeline sending both requests and manipulate the queue as necessary
		1163	in the callbacks.
		1164
		1165	When the first callback is called and sees an "OK" response, it will
		1166	C<unshift> another line-read. This line-read will be queued I<before> the
		1167	64-byte chunk callback.
		1168
		1169	# request one, returns either "OK + extra line" or "ERROR"
		1170	$handle->push_write ("request 1\015\012");
		1171
		1172	# we expect "ERROR" or "OK" as response, so push a line read
		1173	$handle->push_read (line => sub {
		1174	# if we got an "OK", we have to _prepend_ another line,
		1175	# so it will be read before the second request reads its 64 bytes
		1176	# which are already in the queue when this callback is called
		1177	# we don't do this in case we got an error
		1178	if ($_[1] eq "OK") {
		1179	$_[0]->unshift_read (line => sub {
		1180	my $response = $_[1];
		1181	...
		1182	});
38	}	1183	}
39	});	1184	});
40		1185
41	# or use the constructor to pass the callback:	1186	# request two, simply returns 64 octets
		1187	$handle->push_write ("request 2\015\012");
42		1188
43	my $ae_fh2 =	1189	# simply read 64 bytes, always
44	AnyEvent::Handle->new (	1190	$handle->push_read (chunk => 64, sub {
45	fh => \*STDIN,	1191	my $response = $_[1];
46	on_eof => sub {	1192	...
47	$cv->broadcast;	1193	});
48	},	1194
49	on_readline => sub {	1195	=over 4
50	my ($ae_fh, @lines) = @_;	1196
51	for (@lines) {	1197	=cut
52	chomp;	1198
53	print "Line: $_";	1199	sub _drain_rbuf {
		1200	my ($self) = @_;
		1201
		1202	# avoid recursion
		1203	return if $self->{_skip_drain_rbuf};
		1204	local $self->{_skip_drain_rbuf} = 1;
		1205
		1206	while () {
		1207	# we need to use a separate tls read buffer, as we must not receive data while
		1208	# we are draining the buffer, and this can only happen with TLS.
		1209	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1210	if exists $self->{_tls_rbuf};
		1211
		1212	my $len = length $self->{rbuf};
		1213
		1214	if (my $cb = shift @{ $self->{_queue} }) {
		1215	unless ($cb->($self)) {
		1216	# no progress can be made
		1217	# (not enough data and no data forthcoming)
		1218	$self->_error (Errno::EPIPE, 1), return
		1219	if $self->{_eof};
		1220
		1221	unshift @{ $self->{_queue} }, $cb;
54	}	1222	last;
55	}	1223	}
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}) {	1224	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	1225	last unless $len;
122		1226
		1227	$self->{on_read}($self);
		1228
		1229	if (
		1230	$len == length $self->{rbuf} # if no data has been consumed
		1231	&& !@{ $self->{_queue} } # and the queue is still empty
		1232	&& $self->{on_read} # but we still have on_read
		1233	) {
		1234	# no further data will arrive
		1235	# so no progress can be made
		1236	$self->_error (Errno::EPIPE, 1), return
		1237	if $self->{_eof};
		1238
		1239	last; # more data might arrive
		1240	}
		1241	} else {
		1242	# read side becomes idle
		1243	delete $self->{_rw} unless $self->{tls};
		1244	last;
		1245	}
		1246	}
		1247
123	} elsif ($self->{on_eof}) {	1248	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});	1249	$self->{on_eof}
		1250	? $self->{on_eof}($self)
		1251	: $self->_error (0, 1, "Unexpected end-of-file");
125		1252
126	} elsif ($self->{on_error}) {	1253	return;
127	$self->on_eof ($self->{on_error});
128	}	1254	}
129		1255
130	return $self	1256	if (
131	}	1257	defined $self->{rbuf_max}
		1258	&& $self->{rbuf_max} < length $self->{rbuf}
		1259	) {
		1260	$self->_error (Errno::ENOSPC, 1), return;
		1261	}
132		1262
133	=item B<fh>	1263	# may need to restart read watcher
		1264	unless ($self->{_rw}) {
		1265	$self->start_read
		1266	if $self->{on_read} || @{ $self->{_queue} };
		1267	}
		1268	}
134		1269
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	1270	=item $handle->on_read ($cb)
136		1271
137	=cut	1272	This replaces the currently set C<on_read> callback, or clears it (when
		1273	the new callback is C<undef>). See the description of C<on_read> in the
		1274	constructor.
138		1275
139	sub fh { $_[0]->{fh} }	1276	This method may invoke callbacks (and therefore the handle might be
140		1277	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		1278
149	=cut	1279	=cut
150		1280
151	sub on_read {	1281	sub on_read {
152	my ($self, $cb) = @_;	1282	my ($self, $cb) = @_;
		1283
153	$self->{on_read} = $cb;	1284	$self->{on_read} = $cb;
		1285	$self->_drain_rbuf if $cb;
		1286	}
154		1287
155	unless (defined $self->{on_read}) {	1288	=item $handle->rbuf
156	delete $self->{on_read_w};	1289
		1290	Returns the read buffer (as a modifiable lvalue). You can also access the
		1291	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1292	much faster, and no less clean).
		1293
		1294	The only operation allowed on the read buffer (apart from looking at it)
		1295	is removing data from its beginning. Otherwise modifying or appending to
		1296	it is not allowed and will lead to hard-to-track-down bugs.
		1297
		1298	NOTE: The read buffer should only be used or modified in the C<on_read>
		1299	callback or when C<push_read> or C<unshift_read> are used with a single
		1300	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1301	will manage the read buffer on their own.
		1302
		1303	=cut
		1304
		1305	sub rbuf : lvalue {
		1306	$_[0]{rbuf}
		1307	}
		1308
		1309	=item $handle->push_read ($cb)
		1310
		1311	=item $handle->unshift_read ($cb)
		1312
		1313	Append the given callback to the end of the queue (C<push_read>) or
		1314	prepend it (C<unshift_read>).
		1315
		1316	The callback is called each time some additional read data arrives.
		1317
		1318	It must check whether enough data is in the read buffer already.
		1319
		1320	If not enough data is available, it must return the empty list or a false
		1321	value, in which case it will be called repeatedly until enough data is
		1322	available (or an error condition is detected).
		1323
		1324	If enough data was available, then the callback must remove all data it is
		1325	interested in (which can be none at all) and return a true value. After returning
		1326	true, it will be removed from the queue.
		1327
		1328	These methods may invoke callbacks (and therefore the handle might be
		1329	destroyed after it returns).
		1330
		1331	=cut
		1332
		1333	our %RH;
		1334
		1335	sub register_read_type($$) {
		1336	$RH{$_[0]} = $_[1];
		1337	}
		1338
		1339	sub push_read {
		1340	my $self = shift;
		1341	my $cb = pop;
		1342
		1343	if (@_) {
		1344	my $type = shift;
		1345
		1346	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1347	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1348	->($self, $cb, @_);
		1349	}
		1350
		1351	push @{ $self->{_queue} }, $cb;
		1352	$self->_drain_rbuf;
		1353	}
		1354
		1355	sub unshift_read {
		1356	my $self = shift;
		1357	my $cb = pop;
		1358
		1359	if (@_) {
		1360	my $type = shift;
		1361
		1362	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1363	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
		1364	->($self, $cb, @_);
		1365	}
		1366
		1367	unshift @{ $self->{_queue} }, $cb;
		1368	$self->_drain_rbuf;
		1369	}
		1370
		1371	=item $handle->push_read (type => @args, $cb)
		1372
		1373	=item $handle->unshift_read (type => @args, $cb)
		1374
		1375	Instead of providing a callback that parses the data itself you can chose
		1376	between a number of predefined parsing formats, for chunks of data, lines
		1377	etc. You can also specify the (fully qualified) name of a package, in
		1378	which case AnyEvent tries to load the package and then expects to find the
		1379	C<anyevent_read_type> function inside (see "custom read types", below).
		1380
		1381	Predefined types are (if you have ideas for additional types, feel free to
		1382	drop by and tell us):
		1383
		1384	=over 4
		1385
		1386	=item chunk => $octets, $cb->($handle, $data)
		1387
		1388	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1389	data read to the callback. The callback will never be called with less
		1390	data.
		1391
		1392	Example: read 2 bytes.
		1393
		1394	$handle->push_read (chunk => 2, sub {
		1395	warn "yay ", unpack "H*", $_[1];
		1396	});
		1397
		1398	=cut
		1399
		1400	register_read_type chunk => sub {
		1401	my ($self, $cb, $len) = @_;
		1402
		1403	sub {
		1404	$len <= length $_[0]{rbuf} or return;
		1405	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		1406	1
		1407	}
		1408	};
		1409
		1410	=item line => [$eol, ]$cb->($handle, $line, $eol)
		1411
		1412	The callback will be called only once a full line (including the end of
		1413	line marker, C<$eol>) has been read. This line (excluding the end of line
		1414	marker) will be passed to the callback as second argument (C<$line>), and
		1415	the end of line marker as the third argument (C<$eol>).
		1416
		1417	The end of line marker, C<$eol>, can be either a string, in which case it
		1418	will be interpreted as a fixed record end marker, or it can be a regex
		1419	object (e.g. created by C<qr>), in which case it is interpreted as a
		1420	regular expression.
		1421
		1422	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		1423	undef), then C<qr|\015?\012|> is used (which is good for most internet
		1424	protocols).
		1425
		1426	Partial lines at the end of the stream will never be returned, as they are
		1427	not marked by the end of line marker.
		1428
		1429	=cut
		1430
		1431	register_read_type line => sub {
		1432	my ($self, $cb, $eol) = @_;
		1433
		1434	if (@_ < 3) {
		1435	# this is more than twice as fast as the generic code below
		1436	sub {
		1437	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1438
		1439	$cb->($_[0], $1, $2);
		1440	1
		1441	}
		1442	} else {
		1443	$eol = quotemeta $eol unless ref $eol;
		1444	$eol = qr|^(.*?)($eol)|s;
		1445
		1446	sub {
		1447	$_[0]{rbuf} =~ s/$eol// or return;
		1448
		1449	$cb->($_[0], $1, $2);
		1450	1
		1451	}
		1452	}
		1453	};
		1454
		1455	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1456
		1457	Makes a regex match against the regex object C<$accept> and returns
		1458	everything up to and including the match.
		1459
		1460	Example: read a single line terminated by '\n'.
		1461
		1462	$handle->push_read (regex => qr<\n>, sub { ... });
		1463
		1464	If C<$reject> is given and not undef, then it determines when the data is
		1465	to be rejected: it is matched against the data when the C<$accept> regex
		1466	does not match and generates an C<EBADMSG> error when it matches. This is
		1467	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1468	receive buffer overflow).
		1469
		1470	Example: expect a single decimal number followed by whitespace, reject
		1471	anything else (not the use of an anchor).
		1472
		1473	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1474
		1475	If C<$skip> is given and not C<undef>, then it will be matched against
		1476	the receive buffer when neither C<$accept> nor C<$reject> match,
		1477	and everything preceding and including the match will be accepted
		1478	unconditionally. This is useful to skip large amounts of data that you
		1479	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1480	have to start matching from the beginning. This is purely an optimisation
		1481	and is usually worth it only when you expect more than a few kilobytes.
		1482
		1483	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1484	expect the header to be very large (it isn't in practice, but...), we use
		1485	a skip regex to skip initial portions. The skip regex is tricky in that
		1486	it only accepts something not ending in either \015 or \012, as these are
		1487	required for the accept regex.
		1488
		1489	$handle->push_read (regex =>
		1490	qr<\015\012\015\012>,
		1491	undef, # no reject
		1492	qr<^.*[^\015\012]>,
		1493	sub { ... });
		1494
		1495	=cut
		1496
		1497	register_read_type regex => sub {
		1498	my ($self, $cb, $accept, $reject, $skip) = @_;
		1499
		1500	my $data;
		1501	my $rbuf = \$self->{rbuf};
		1502
		1503	sub {
		1504	# accept
		1505	if ($$rbuf =~ $accept) {
		1506	$data .= substr $$rbuf, 0, $+[0], "";
		1507	$cb->($self, $data);
		1508	return 1;
		1509	}
		1510
		1511	# reject
		1512	if ($reject && $$rbuf =~ $reject) {
		1513	$self->_error (Errno::EBADMSG);
		1514	}
		1515
		1516	# skip
		1517	if ($skip && $$rbuf =~ $skip) {
		1518	$data .= substr $$rbuf, 0, $+[0], "";
		1519	}
		1520
		1521	()
		1522	}
		1523	};
		1524
		1525	=item netstring => $cb->($handle, $string)
		1526
		1527	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1528
		1529	Throws an error with C<$!> set to EBADMSG on format violations.
		1530
		1531	=cut
		1532
		1533	register_read_type netstring => sub {
		1534	my ($self, $cb) = @_;
		1535
		1536	sub {
		1537	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1538	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1539	$self->_error (Errno::EBADMSG);
		1540	}
157	return;	1541	return;
		1542	}
		1543
		1544	my $len = $1;
		1545
		1546	$self->unshift_read (chunk => $len, sub {
		1547	my $string = $_[1];
		1548	$_[0]->unshift_read (chunk => 1, sub {
		1549	if ($_[1] eq ",") {
		1550	$cb->($_[0], $string);
		1551	} else {
		1552	$self->_error (Errno::EBADMSG);
		1553	}
		1554	});
		1555	});
		1556
		1557	1
		1558	}
		1559	};
		1560
		1561	=item packstring => $format, $cb->($handle, $string)
		1562
		1563	An octet string prefixed with an encoded length. The encoding C<$format>
		1564	uses the same format as a Perl C<pack> format, but must specify a single
		1565	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1566	optional C<!>, C<< < >> or C<< > >> modifier).
		1567
		1568	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1569	EPP uses a prefix of C<N> (4 octtes).
		1570
		1571	Example: read a block of data prefixed by its length in BER-encoded
		1572	format (very efficient).
		1573
		1574	$handle->push_read (packstring => "w", sub {
		1575	my ($handle, $data) = @_;
158	}	1576	});
159		1577
160	$self->{on_read_w} =	1578	=cut
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1579
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1580	register_read_type packstring => sub {
		1581	my ($self, $cb, $format) = @_;
		1582
		1583	sub {
		1584	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1585	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1586	or return;
		1587
		1588	$format = length pack $format, $len;
		1589
		1590	# bypass unshift if we already have the remaining chunk
		1591	if ($format + $len <= length $_[0]{rbuf}) {
		1592	my $data = substr $_[0]{rbuf}, $format, $len;
		1593	substr $_[0]{rbuf}, 0, $format + $len, "";
		1594	$cb->($_[0], $data);
		1595	} else {
		1596	# remove prefix
		1597	substr $_[0]{rbuf}, 0, $format, "";
		1598
		1599	# read remaining chunk
		1600	$_[0]->unshift_read (chunk => $len, $cb);
		1601	}
		1602
		1603	1
		1604	}
		1605	};
		1606
		1607	=item json => $cb->($handle, $hash_or_arrayref)
		1608
		1609	Reads a JSON object or array, decodes it and passes it to the
		1610	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1611
		1612	If a C<json> object was passed to the constructor, then that will be used
		1613	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1614
		1615	This read type uses the incremental parser available with JSON version
		1616	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1617	dependency on your own: this module will load the JSON module, but
		1618	AnyEvent does not depend on it itself.
		1619
		1620	Since JSON texts are fully self-delimiting, the C<json> read and write
		1621	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1622	the C<json> write type description, above, for an actual example.
		1623
		1624	=cut
		1625
		1626	register_read_type json => sub {
		1627	my ($self, $cb) = @_;
		1628
		1629	my $json = $self->{json} ||= json_coder;
		1630
		1631	my $data;
163	my $rbuf_len = length $self->{rbuf};	1632	my $rbuf = \$self->{rbuf};
164	my $l;	1633
		1634	sub {
		1635	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1636
		1637	if ($ref) {
		1638	$self->{rbuf} = $json->incr_text;
		1639	$json->incr_text = "";
		1640	$cb->($self, $ref);
		1641
		1642	1
		1643	} elsif ($@) {
		1644	# error case
		1645	$json->incr_skip;
		1646
		1647	$self->{rbuf} = $json->incr_text;
		1648	$json->incr_text = "";
		1649
		1650	$self->_error (Errno::EBADMSG);
		1651
		1652	()
		1653	} else {
		1654	$self->{rbuf} = "";
		1655
		1656	()
		1657	}
		1658	}
		1659	};
		1660
		1661	=item storable => $cb->($handle, $ref)
		1662
		1663	Deserialises a L<Storable> frozen representation as written by the
		1664	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1665	data).
		1666
		1667	Raises C<EBADMSG> error if the data could not be decoded.
		1668
		1669	=cut
		1670
		1671	register_read_type storable => sub {
		1672	my ($self, $cb) = @_;
		1673
		1674	require Storable;
		1675
		1676	sub {
		1677	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1678	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1679	or return;
		1680
		1681	my $format = length pack "w", $len;
		1682
		1683	# bypass unshift if we already have the remaining chunk
		1684	if ($format + $len <= length $_[0]{rbuf}) {
		1685	my $data = substr $_[0]{rbuf}, $format, $len;
		1686	substr $_[0]{rbuf}, 0, $format + $len, "";
		1687	$cb->($_[0], Storable::thaw ($data));
		1688	} else {
		1689	# remove prefix
		1690	substr $_[0]{rbuf}, 0, $format, "";
		1691
		1692	# read remaining chunk
		1693	$_[0]->unshift_read (chunk => $len, sub {
		1694	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1695	$cb->($_[0], $ref);
		1696	} else {
		1697	$self->_error (Errno::EBADMSG);
		1698	}
		1699	});
		1700	}
		1701
		1702	1
		1703	}
		1704	};
		1705
		1706	=back
		1707
		1708	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1709
		1710	Instead of one of the predefined types, you can also specify the name
		1711	of a package. AnyEvent will try to load the package and then expects to
		1712	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1713	progressively tries to load the parent package until it either finds the
		1714	function (good) or runs out of packages (bad).
		1715
		1716	Whenever this type is used, C<push_read> will invoke the function with the
		1717	handle object, the original callback and the remaining arguments.
		1718
		1719	The function is supposed to return a callback (usually a closure) that
		1720	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1721	mentally treat the function as a "configurable read type to read callback"
		1722	converter.
		1723
		1724	It should invoke the original callback when it is done reading (remember
		1725	to pass C<$handle> as first argument as all other callbacks do that,
		1726	although there is no strict requirement on this).
		1727
		1728	For examples, see the source of this module (F<perldoc -m
		1729	AnyEvent::Handle>, search for C<register_read_type>)).
		1730
		1731	=item $handle->stop_read
		1732
		1733	=item $handle->start_read
		1734
		1735	In rare cases you actually do not want to read anything from the
		1736	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1737	any queued callbacks will be executed then. To start reading again, call
		1738	C<start_read>.
		1739
		1740	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1741	you change the C<on_read> callback or push/unshift a read callback, and it
		1742	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1743	there are any read requests in the queue.
		1744
		1745	These methods will have no effect when in TLS mode (as TLS doesn't support
		1746	half-duplex connections).
		1747
		1748	=cut
		1749
		1750	sub stop_read {
		1751	my ($self) = @_;
		1752
		1753	delete $self->{_rw} unless $self->{tls};
		1754	}
		1755
		1756	sub start_read {
		1757	my ($self) = @_;
		1758
		1759	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		1760	Scalar::Util::weaken $self;
		1761
		1762	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1763	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1764	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
		1765
		1766	if ($len > 0) {
		1767	$self->{_activity} = $self->{_ractivity} = AE::now;
		1768
		1769	if ($self->{tls}) {
		1770	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1771
		1772	&_dotls ($self);
		1773	} else {
		1774	$self->_drain_rbuf;
		1775	}
		1776
165	if (defined $self->{read_size}) {	1777	if ($len == $self->{read_size}) {
166	$l = sysread $self->{fh}, $self->{rbuf},	1778	$self->{read_size} *= 2;
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1779	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1780	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1781	}
		1782
		1783	} elsif (defined $len) {
		1784	delete $self->{_rw};
		1785	$self->{_eof} = 1;
		1786	$self->_drain_rbuf;
		1787
		1788	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1789	return $self->_error ($!, 1);
		1790	}
		1791	};
		1792	}
		1793	}
		1794
		1795	our $ERROR_SYSCALL;
		1796	our $ERROR_WANT_READ;
		1797
		1798	sub _tls_error {
		1799	my ($self, $err) = @_;
		1800
		1801	return $self->_error ($!, 1)
		1802	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1803
		1804	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1805
		1806	# reduce error string to look less scary
		1807	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1808
		1809	if ($self->{_on_starttls}) {
		1810	(delete $self->{_on_starttls})->($self, undef, $err);
		1811	&_freetls;
		1812	} else {
		1813	&_freetls;
		1814	$self->_error (Errno::EPROTO, 1, $err);
		1815	}
		1816	}
		1817
		1818	# poll the write BIO and send the data if applicable
		1819	# also decode read data if possible
		1820	# this is basiclaly our TLS state machine
		1821	# more efficient implementations are possible with openssl,
		1822	# but not with the buggy and incomplete Net::SSLeay.
		1823	sub _dotls {
		1824	my ($self) = @_;
		1825
		1826	my $tmp;
		1827
		1828	if (length $self->{_tls_wbuf}) {
		1829	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1830	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1831	}
		1832
		1833	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1834	return $self->_tls_error ($tmp)
		1835	if $tmp != $ERROR_WANT_READ
		1836	&& ($tmp != $ERROR_SYSCALL || $!);
		1837	}
		1838
		1839	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1840	unless (length $tmp) {
		1841	$self->{_on_starttls}
		1842	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1843	&_freetls;
		1844
		1845	if ($self->{on_stoptls}) {
		1846	$self->{on_stoptls}($self);
		1847	return;
168	} else {	1848	} else {
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1849	# 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};	1850	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];	1851	$self->{_eof} = 1;
316	}	1852	}
317	}	1853	}
318	return;
319	}
320		1854
321	my $wba = shift @{$self->{write_bufs}}	1855	$self->{_tls_rbuf} .= $tmp;
322	or return;	1856	$self->_drain_rbuf;
323		1857	$self->{tls} or return; # tls session might have gone away in callback
324	unless (defined $wba->[0]) {
325	$wba->[1]->($self) if $wba->[1];
326	$self->_check_writer;
327	return;
328	}	1858	}
329		1859
330	$self->{wbuf} = $wba->[0];	1860	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
331	$self->{write_cb} = $wba->[1];	1861	return $self->_tls_error ($tmp)
		1862	if $tmp != $ERROR_WANT_READ
		1863	&& ($tmp != $ERROR_SYSCALL || $!);
332		1864
333	$self->{write_w} =	1865	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1866	$self->{wbuf} .= $tmp;
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1867	$self->_drain_wbuf;
		1868	$self->{tls} or return; # tls session might have gone away in callback
		1869	}
336		1870
337	if (not defined $l) {	1871	$self->{_on_starttls}
338	return if $! == EAGAIN || $! == EINTR;	1872	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
339	delete $self->{write_w};	1873	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
340	$self->{on_error}->($self) if $self->{on_error};	1874	}
341		1875
		1876	=item $handle->starttls ($tls[, $tls_ctx])
		1877
		1878	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1879	object is created, you can also do that at a later time by calling
		1880	C<starttls>.
		1881
		1882	Starting TLS is currently an asynchronous operation - when you push some
		1883	write data and then call C<< ->starttls >> then TLS negotiation will start
		1884	immediately, after which the queued write data is then sent.
		1885
		1886	The first argument is the same as the C<tls> constructor argument (either
		1887	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1888
		1889	The second argument is the optional C<AnyEvent::TLS> object that is used
		1890	when AnyEvent::Handle has to create its own TLS connection object, or
		1891	a hash reference with C<< key => value >> pairs that will be used to
		1892	construct a new context.
		1893
		1894	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1895	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1896	changed to your liking. Note that the handshake might have already started
		1897	when this function returns.
		1898
		1899	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1900	handshakes on the same stream. It is best to not attempt to use the
		1901	stream after stopping TLS.
		1902
		1903	This method may invoke callbacks (and therefore the handle might be
		1904	destroyed after it returns).
		1905
		1906	=cut
		1907
		1908	our %TLS_CACHE; #TODO not yet documented, should we?
		1909
		1910	sub starttls {
		1911	my ($self, $tls, $ctx) = @_;
		1912
		1913	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1914	if $self->{tls};
		1915
		1916	$self->{tls} = $tls;
		1917	$self->{tls_ctx} = $ctx if @_ > 2;
		1918
		1919	return unless $self->{fh};
		1920
		1921	require Net::SSLeay;
		1922
		1923	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1924	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1925
		1926	$tls = delete $self->{tls};
		1927	$ctx = $self->{tls_ctx};
		1928
		1929	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1930
		1931	if ("HASH" eq ref $ctx) {
		1932	require AnyEvent::TLS;
		1933
		1934	if ($ctx->{cache}) {
		1935	my $key = $ctx+0;
		1936	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
342	} else {	1937	} else {
		1938	$ctx = new AnyEvent::TLS %$ctx;
		1939	}
		1940	}
		1941
		1942	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1943	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		1944
		1945	# basically, this is deep magic (because SSL_read should have the same issues)
		1946	# but the openssl maintainers basically said: "trust us, it just works".
		1947	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1948	# and mismaintained ssleay-module doesn't even offer them).
		1949	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1950	#
		1951	# in short: this is a mess.
		1952	#
		1953	# note that we do not try to keep the length constant between writes as we are required to do.
		1954	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1955	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1956	# have identity issues in that area.
		1957	# Net::SSLeay::CTX_set_mode ($ssl,
		1958	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1959	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1960	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		1961
		1962	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1963	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1964
		1965	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1966
		1967	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1968
		1969	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1970	if $self->{on_starttls};
		1971
		1972	&_dotls; # need to trigger the initial handshake
		1973	$self->start_read; # make sure we actually do read
		1974	}
		1975
		1976	=item $handle->stoptls
		1977
		1978	Shuts down the SSL connection - this makes a proper EOF handshake by
		1979	sending a close notify to the other side, but since OpenSSL doesn't
		1980	support non-blocking shut downs, it is not guaranteed that you can re-use
		1981	the stream afterwards.
		1982
		1983	This method may invoke callbacks (and therefore the handle might be
		1984	destroyed after it returns).
		1985
		1986	=cut
		1987
		1988	sub stoptls {
		1989	my ($self) = @_;
		1990
		1991	if ($self->{tls} && $self->{fh}) {
		1992	Net::SSLeay::shutdown ($self->{tls});
		1993
		1994	&_dotls;
		1995
		1996	# # we don't give a shit. no, we do, but we can't. no...#d#
		1997	# # we, we... have to use openssl :/#d#
		1998	# &_freetls;#d#
		1999	}
		2000	}
		2001
		2002	sub _freetls {
		2003	my ($self) = @_;
		2004
		2005	return unless $self->{tls};
		2006
		2007	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2008	if $self->{tls} > 0;
		2009
		2010	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2011	}
		2012
		2013	sub DESTROY {
		2014	my ($self) = @_;
		2015
		2016	&_freetls;
		2017
		2018	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2019
		2020	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2021	my $fh = delete $self->{fh};
		2022	my $wbuf = delete $self->{wbuf};
		2023
		2024	my @linger;
		2025
		2026	push @linger, AE::io $fh, 1, sub {
		2027	my $len = syswrite $fh, $wbuf, length $wbuf;
		2028
		2029	if ($len > 0) {
343	substr $self->{wbuf}, 0, $l, '';	2030	substr $wbuf, 0, $len, "";
344		2031	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
345	if (length ($self->{wbuf}) == 0) {	2032	@linger = (); # end
346	$self->{write_cb}->($self) if $self->{write_cb};
347
348	delete $self->{write_w};
349	delete $self->{wbuf};
350	delete $self->{write_cb};
351
352	$self->_check_writer;
353	}
354	}	2033	}
355	});	2034	};
		2035	push @linger, AE::timer $linger, 0, sub {
		2036	@linger = ();
		2037	};
		2038	}
		2039	}
		2040
		2041	=item $handle->destroy
		2042
		2043	Shuts down the handle object as much as possible - this call ensures that
		2044	no further callbacks will be invoked and as many resources as possible
		2045	will be freed. Any method you will call on the handle object after
		2046	destroying it in this way will be silently ignored (and it will return the
		2047	empty list).
		2048
		2049	Normally, you can just "forget" any references to an AnyEvent::Handle
		2050	object and it will simply shut down. This works in fatal error and EOF
		2051	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2052	callback, so when you want to destroy the AnyEvent::Handle object from
		2053	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2054	that case.
		2055
		2056	Destroying the handle object in this way has the advantage that callbacks
		2057	will be removed as well, so if those are the only reference holders (as
		2058	is common), then one doesn't need to do anything special to break any
		2059	reference cycles.
		2060
		2061	The handle might still linger in the background and write out remaining
		2062	data, as specified by the C<linger> option, however.
		2063
		2064	=cut
		2065
		2066	sub destroy {
		2067	my ($self) = @_;
		2068
		2069	$self->DESTROY;
		2070	%$self = ();
		2071	bless $self, "AnyEvent::Handle::destroyed";
		2072	}
		2073
		2074	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2075	#nop
		2076	}
		2077
		2078	=item $handle->destroyed
		2079
		2080	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2081	->destroy >>, true otherwise.
		2082
		2083	Can be useful to decide whether the handle is still valid after some
		2084	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2085	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2086	can destroy the handle, so work can be avoided by checking sometimes:
		2087
		2088	$hdl->starttls ("accept");
		2089	return if $hdl->destroyed;
		2090	$hdl->push_write (...
		2091
		2092	Note that the call to C<push_write> will silently be ignored if the handle
		2093	has been destroyed, so often you can just ignore the possibility of the
		2094	handle being destroyed.
		2095
		2096	=cut
		2097
		2098	sub destroyed { 0 }
		2099	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2100
		2101	=item AnyEvent::Handle::TLS_CTX
		2102
		2103	This function creates and returns the AnyEvent::TLS object used by default
		2104	for TLS mode.
		2105
		2106	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2107
		2108	=cut
		2109
		2110	our $TLS_CTX;
		2111
		2112	sub TLS_CTX() {
		2113	$TLS_CTX ||= do {
		2114	require AnyEvent::TLS;
		2115
		2116	new AnyEvent::TLS
		2117	}
356	}	2118	}
357		2119
358	=back	2120	=back
359		2121
		2122
		2123	=head1 NONFREQUENTLY ASKED QUESTIONS
		2124
		2125	=over 4
		2126
		2127	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2128	still get further invocations!
		2129
		2130	That's because AnyEvent::Handle keeps a reference to itself when handling
		2131	read or write callbacks.
		2132
		2133	It is only safe to "forget" the reference inside EOF or error callbacks,
		2134	from within all other callbacks, you need to explicitly call the C<<
		2135	->destroy >> method.
		2136
		2137	=item I get different callback invocations in TLS mode/Why can't I pause
		2138	reading?
		2139
		2140	Unlike, say, TCP, TLS connections do not consist of two independent
		2141	communication channels, one for each direction. Or put differently, the
		2142	read and write directions are not independent of each other: you cannot
		2143	write data unless you are also prepared to read, and vice versa.
		2144
		2145	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2146	callback invocations when you are not expecting any read data - the reason
		2147	is that AnyEvent::Handle always reads in TLS mode.
		2148
		2149	During the connection, you have to make sure that you always have a
		2150	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2151	connection (or when you no longer want to use it) you can call the
		2152	C<destroy> method.
		2153
		2154	=item How do I read data until the other side closes the connection?
		2155
		2156	If you just want to read your data into a perl scalar, the easiest way
		2157	to achieve this is by setting an C<on_read> callback that does nothing,
		2158	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2159	will be in C<$_[0]{rbuf}>:
		2160
		2161	$handle->on_read (sub { });
		2162	$handle->on_eof (undef);
		2163	$handle->on_error (sub {
		2164	my $data = delete $_[0]{rbuf};
		2165	});
		2166
		2167	The reason to use C<on_error> is that TCP connections, due to latencies
		2168	and packets loss, might get closed quite violently with an error, when in
		2169	fact all data has been received.
		2170
		2171	It is usually better to use acknowledgements when transferring data,
		2172	to make sure the other side hasn't just died and you got the data
		2173	intact. This is also one reason why so many internet protocols have an
		2174	explicit QUIT command.
		2175
		2176	=item I don't want to destroy the handle too early - how do I wait until
		2177	all data has been written?
		2178
		2179	After writing your last bits of data, set the C<on_drain> callback
		2180	and destroy the handle in there - with the default setting of
		2181	C<low_water_mark> this will be called precisely when all data has been
		2182	written to the socket:
		2183
		2184	$handle->push_write (...);
		2185	$handle->on_drain (sub {
		2186	warn "all data submitted to the kernel\n";
		2187	undef $handle;
		2188	});
		2189
		2190	If you just want to queue some data and then signal EOF to the other side,
		2191	consider using C<< ->push_shutdown >> instead.
		2192
		2193	=item I want to contact a TLS/SSL server, I don't care about security.
		2194
		2195	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2196	connect to it and then create the AnyEvent::Handle with the C<tls>
		2197	parameter:
		2198
		2199	tcp_connect $host, $port, sub {
		2200	my ($fh) = @_;
		2201
		2202	my $handle = new AnyEvent::Handle
		2203	fh => $fh,
		2204	tls => "connect",
		2205	on_error => sub { ... };
		2206
		2207	$handle->push_write (...);
		2208	};
		2209
		2210	=item I want to contact a TLS/SSL server, I do care about security.
		2211
		2212	Then you should additionally enable certificate verification, including
		2213	peername verification, if the protocol you use supports it (see
		2214	L<AnyEvent::TLS>, C<verify_peername>).
		2215
		2216	E.g. for HTTPS:
		2217
		2218	tcp_connect $host, $port, sub {
		2219	my ($fh) = @_;
		2220
		2221	my $handle = new AnyEvent::Handle
		2222	fh => $fh,
		2223	peername => $host,
		2224	tls => "connect",
		2225	tls_ctx => { verify => 1, verify_peername => "https" },
		2226	...
		2227
		2228	Note that you must specify the hostname you connected to (or whatever
		2229	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2230	peername verification will be done.
		2231
		2232	The above will use the system-dependent default set of trusted CA
		2233	certificates. If you want to check against a specific CA, add the
		2234	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2235
		2236	tls_ctx => {
		2237	verify => 1,
		2238	verify_peername => "https",
		2239	ca_file => "my-ca-cert.pem",
		2240	},
		2241
		2242	=item I want to create a TLS/SSL server, how do I do that?
		2243
		2244	Well, you first need to get a server certificate and key. You have
		2245	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2246	self-signed certificate (cheap. check the search engine of your choice,
		2247	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2248	nice program for that purpose).
		2249
		2250	Then create a file with your private key (in PEM format, see
		2251	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2252	file should then look like this:
		2253
		2254	-----BEGIN RSA PRIVATE KEY-----
		2255	...header data
		2256	... lots of base64'y-stuff
		2257	-----END RSA PRIVATE KEY-----
		2258
		2259	-----BEGIN CERTIFICATE-----
		2260	... lots of base64'y-stuff
		2261	-----END CERTIFICATE-----
		2262
		2263	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2264	specify this file as C<cert_file>:
		2265
		2266	tcp_server undef, $port, sub {
		2267	my ($fh) = @_;
		2268
		2269	my $handle = new AnyEvent::Handle
		2270	fh => $fh,
		2271	tls => "accept",
		2272	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2273	...
		2274
		2275	When you have intermediate CA certificates that your clients might not
		2276	know about, just append them to the C<cert_file>.
		2277
		2278	=back
		2279
		2280
		2281	=head1 SUBCLASSING AnyEvent::Handle
		2282
		2283	In many cases, you might want to subclass AnyEvent::Handle.
		2284
		2285	To make this easier, a given version of AnyEvent::Handle uses these
		2286	conventions:
		2287
		2288	=over 4
		2289
		2290	=item * all constructor arguments become object members.
		2291
		2292	At least initially, when you pass a C<tls>-argument to the constructor it
		2293	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2294	mutated later on (for example C<tls> will hold the TLS connection object).
		2295
		2296	=item * other object member names are prefixed with an C<_>.
		2297
		2298	All object members not explicitly documented (internal use) are prefixed
		2299	with an underscore character, so the remaining non-C<_>-namespace is free
		2300	for use for subclasses.
		2301
		2302	=item * all members not documented here and not prefixed with an underscore
		2303	are free to use in subclasses.
		2304
		2305	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2306	member variables, but that's just life. At least it is documented.
		2307
		2308	=back
		2309
360	=head1 AUTHOR	2310	=head1 AUTHOR
361		2311
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	2312	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363		2313
364	=cut	2314	=cut
365		2315
366	1; # End of AnyEvent::Handle	2316	1; # End of AnyEvent::Handle

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