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Revision 1.4 by elmex, Sun Apr 27 20:20:20 2008 UTC vs.
Revision 1.80 by root, Sun Jul 27 08:43:32 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	use warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent;	6	use AnyEvent ();
7	use IO::Handle;	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		8	use Scalar::Util ();
		9	use Carp ();
		10	use Fcntl ();
8	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
9		12
10	=head1 NAME	13	=head1 NAME
11		14
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13		16
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut	17	=cut
19		18
20	our $VERSION = '0.01';	19	our $VERSION = 4.22;
21		20
22	=head1 SYNOPSIS	21	=head1 SYNOPSIS
23		22
24	use AnyEvent;	23	use AnyEvent;
25	use AnyEvent::Handle;	24	use AnyEvent::Handle;
26		25
27	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
28		27
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
30
31	$ae_fh->on_eof (sub { $cv->broadcast });
32
33	$ae_fh->readlines (sub {
34	my ($ae_fh, @lines) = @_;
35	for (@lines) {
36	chomp;
37	print "Line: $_";
38	}
39	});
40
41	# or use the constructor to pass the callback:
42
43	my $ae_fh2 =
44	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
45	fh => \*STDIN,	30	fh => \*STDIN,
46	on_eof => sub {	31	on_eof => sub {
47	$cv->broadcast;	32	$cv->broadcast;
48	},	33	},
		34	);
		35
		36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
		41	my ($handle, $line) = @_;
		42	warn "read line <$line>\n";
		43	$cv->send;
		44	});
		45
		46	$cv->recv;
		47
		48	=head1 DESCRIPTION
		49
		50	This module is a helper module to make it easier to do event-based I/O on
		51	filehandles. For utility functions for doing non-blocking connects and accepts
		52	on sockets see L<AnyEvent::Util>.
		53
		54	In the following, when the documentation refers to of "bytes" then this
		55	means characters. As sysread and syswrite are used for all I/O, their
		56	treatment of characters applies to this module as well.
		57
		58	All callbacks will be invoked with the handle object as their first
		59	argument.
		60
		61	=head1 METHODS
		62
		63	=over 4
		64
		65	=item B<new (%args)>
		66
		67	The constructor supports these arguments (all as key => value pairs).
		68
		69	=over 4
		70
		71	=item fh => $filehandle [MANDATORY]
		72
		73	The filehandle this L<AnyEvent::Handle> object will operate on.
		74
		75	NOTE: The filehandle will be set to non-blocking (using
		76	AnyEvent::Util::fh_nonblocking).
		77
		78	=item on_eof => $cb->($handle)
		79
		80	Set the callback to be called when an end-of-file condition is detected,
		81	i.e. in the case of a socket, when the other side has closed the
		82	connection cleanly.
		83
		84	While not mandatory, it is I<highly> recommended to set an eof callback,
		85	otherwise you might end up with a closed socket while you are still
		86	waiting for data.
		87
		88	If an EOF condition has been detected but no C<on_eof> callback has been
		89	set, then a fatal error will be raised with C<$!> set to <0>.
		90
		91	=item on_error => $cb->($handle, $fatal)
		92
		93	This is the error callback, which is called when, well, some error
		94	occured, such as not being able to resolve the hostname, failure to
		95	connect or a read error.
		96
		97	Some errors are fatal (which is indicated by C<$fatal> being true). On
		98	fatal errors the handle object will be shut down and will not be
		99	usable. Non-fatal errors can be retried by simply returning, but it is
		100	recommended to simply ignore this parameter and instead abondon the handle
		101	object when this callback is invoked.
		102
		103	On callback entrance, the value of C<$!> contains the operating system
		104	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
		105
		106	While not mandatory, it is I<highly> recommended to set this callback, as
		107	you will not be notified of errors otherwise. The default simply calls
		108	C<croak>.
		109
		110	=item on_read => $cb->($handle)
		111
		112	This sets the default read callback, which is called when data arrives
		113	and no read request is in the queue (unlike read queue callbacks, this
		114	callback will only be called when at least one octet of data is in the
		115	read buffer).
		116
		117	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		118	method or access the C<$handle->{rbuf}> member directly.
		119
		120	When an EOF condition is detected then AnyEvent::Handle will first try to
		121	feed all the remaining data to the queued callbacks and C<on_read> before
		122	calling the C<on_eof> callback. If no progress can be made, then a fatal
		123	error will be raised (with C<$!> set to C<EPIPE>).
		124
		125	=item on_drain => $cb->($handle)
		126
		127	This sets the callback that is called when the write buffer becomes empty
		128	(or when the callback is set and the buffer is empty already).
		129
		130	To append to the write buffer, use the C<< ->push_write >> method.
		131
		132	This callback is useful when you don't want to put all of your write data
		133	into the queue at once, for example, when you want to write the contents
		134	of some file to the socket you might not want to read the whole file into
		135	memory and push it into the queue, but instead only read more data from
		136	the file when the write queue becomes empty.
		137
		138	=item timeout => $fractional_seconds
		139
		140	If non-zero, then this enables an "inactivity" timeout: whenever this many
		141	seconds pass without a successful read or write on the underlying file
		142	handle, the C<on_timeout> callback will be invoked (and if that one is
		143	missing, an C<ETIMEDOUT> error will be raised).
		144
		145	Note that timeout processing is also active when you currently do not have
		146	any outstanding read or write requests: If you plan to keep the connection
		147	idle then you should disable the timout temporarily or ignore the timeout
		148	in the C<on_timeout> callback.
		149
		150	Zero (the default) disables this timeout.
		151
		152	=item on_timeout => $cb->($handle)
		153
		154	Called whenever the inactivity timeout passes. If you return from this
		155	callback, then the timeout will be reset as if some activity had happened,
		156	so this condition is not fatal in any way.
		157
		158	=item rbuf_max => <bytes>
		159
		160	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		161	when the read buffer ever (strictly) exceeds this size. This is useful to
		162	avoid denial-of-service attacks.
		163
		164	For example, a server accepting connections from untrusted sources should
		165	be configured to accept only so-and-so much data that it cannot act on
		166	(for example, when expecting a line, an attacker could send an unlimited
		167	amount of data without a callback ever being called as long as the line
		168	isn't finished).
		169
		170	=item autocork => <boolean>
		171
		172	When disabled (the default), then C<push_write> will try to immediately
		173	write the data to the handle if possible. This avoids having to register
		174	a write watcher and wait for the next event loop iteration, but can be
		175	inefficient if you write multiple small chunks (this disadvantage is
		176	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		177
		178	When enabled, then writes will always be queued till the next event loop
		179	iteration. This is efficient when you do many small writes per iteration,
		180	but less efficient when you do a single write only.
		181
		182	=item no_delay => <boolean>
		183
		184	When doing small writes on sockets, your operating system kernel might
		185	wait a bit for more data before actually sending it out. This is called
		186	the Nagle algorithm, and usually it is beneficial.
		187
		188	In some situations you want as low a delay as possible, which cna be
		189	accomplishd by setting this option to true.
		190
		191	The default is your opertaing system's default behaviour, this option
		192	explicitly enables or disables it, if possible.
		193
		194	=item read_size => <bytes>
		195
		196	The default read block size (the amount of bytes this module will try to read
		197	during each (loop iteration). Default: C<8192>.
		198
		199	=item low_water_mark => <bytes>
		200
		201	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		202	buffer: If the write reaches this size or gets even samller it is
		203	considered empty.
		204
		205	=item linger => <seconds>
		206
		207	If non-zero (default: C<3600>), then the destructor of the
		208	AnyEvent::Handle object will check wether there is still outstanding write
		209	data and will install a watcher that will write out this data. No errors
		210	will be reported (this mostly matches how the operating system treats
		211	outstanding data at socket close time).
		212
		213	This will not work for partial TLS data that could not yet been
		214	encoded. This data will be lost.
		215
		216	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		217
		218	When this parameter is given, it enables TLS (SSL) mode, that means it
		219	will start making tls handshake and will transparently encrypt/decrypt
		220	data.
		221
		222	TLS mode requires Net::SSLeay to be installed (it will be loaded
		223	automatically when you try to create a TLS handle).
		224
		225	For the TLS server side, use C<accept>, and for the TLS client side of a
		226	connection, use C<connect> mode.
		227
		228	You can also provide your own TLS connection object, but you have
		229	to make sure that you call either C<Net::SSLeay::set_connect_state>
		230	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		231	AnyEvent::Handle.
		232
		233	See the C<starttls> method if you need to start TLS negotiation later.
		234
		235	=item tls_ctx => $ssl_ctx
		236
		237	Use the given Net::SSLeay::CTX object to create the new TLS connection
		238	(unless a connection object was specified directly). If this parameter is
		239	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		240
		241	=item json => JSON or JSON::XS object
		242
		243	This is the json coder object used by the C<json> read and write types.
		244
		245	If you don't supply it, then AnyEvent::Handle will create and use a
		246	suitable one, which will write and expect UTF-8 encoded JSON texts.
		247
		248	Note that you are responsible to depend on the JSON module if you want to
		249	use this functionality, as AnyEvent does not have a dependency itself.
		250
		251	=item filter_r => $cb
		252
		253	=item filter_w => $cb
		254
		255	These exist, but are undocumented at this time.
		256
		257	=back
		258
		259	=cut
		260
		261	sub new {
		262	my $class = shift;
		263
		264	my $self = bless { @_ }, $class;
		265
		266	$self->{fh} or Carp::croak "mandatory argument fh is missing";
		267
		268	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		269
		270	if ($self->{tls}) {
		271	require Net::SSLeay;
		272	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		273	}
		274
		275	$self->{_activity} = AnyEvent->now;
		276	$self->_timeout;
		277
		278	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
		279	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		280
		281	$self->start_read
		282	if $self->{on_read};
		283
		284	$self
		285	}
		286
		287	sub _shutdown {
		288	my ($self) = @_;
		289
		290	delete $self->{_tw};
		291	delete $self->{_rw};
		292	delete $self->{_ww};
		293	delete $self->{fh};
		294
		295	$self->stoptls;
		296	}
		297
		298	sub _error {
		299	my ($self, $errno, $fatal) = @_;
		300
		301	$self->_shutdown
		302	if $fatal;
		303
		304	$! = $errno;
		305
		306	if ($self->{on_error}) {
		307	$self->{on_error}($self, $fatal);
		308	} else {
		309	Carp::croak "AnyEvent::Handle uncaught error: $!";
		310	}
		311	}
		312
		313	=item $fh = $handle->fh
		314
		315	This method returns the file handle of the L<AnyEvent::Handle> object.
		316
		317	=cut
		318
		319	sub fh { $_[0]{fh} }
		320
		321	=item $handle->on_error ($cb)
		322
		323	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		324
		325	=cut
		326
		327	sub on_error {
		328	$_[0]{on_error} = $_[1];
		329	}
		330
		331	=item $handle->on_eof ($cb)
		332
		333	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		334
		335	=cut
		336
		337	sub on_eof {
		338	$_[0]{on_eof} = $_[1];
		339	}
		340
		341	=item $handle->on_timeout ($cb)
		342
		343	Replace the current C<on_timeout> callback, or disables the callback
		344	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		345	argument.
		346
		347	=cut
		348
		349	sub on_timeout {
		350	$_[0]{on_timeout} = $_[1];
		351	}
		352
		353	=item $handle->autocork ($boolean)
		354
		355	Enables or disables the current autocork behaviour (see C<autocork>
		356	constructor argument).
		357
		358	=cut
		359
		360	=item $handle->no_delay ($boolean)
		361
		362	Enables or disables the C<no_delay> setting (see constructor argument of
		363	the same name for details).
		364
		365	=cut
		366
		367	sub no_delay {
		368	$_[0]{no_delay} = $_[1];
		369
		370	eval {
		371	local $SIG{__DIE__};
		372	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		373	};
		374	}
		375
		376	#############################################################################
		377
		378	=item $handle->timeout ($seconds)
		379
		380	Configures (or disables) the inactivity timeout.
		381
		382	=cut
		383
		384	sub timeout {
		385	my ($self, $timeout) = @_;
		386
		387	$self->{timeout} = $timeout;
		388	$self->_timeout;
		389	}
		390
		391	# reset the timeout watcher, as neccessary
		392	# also check for time-outs
		393	sub _timeout {
		394	my ($self) = @_;
		395
		396	if ($self->{timeout}) {
		397	my $NOW = AnyEvent->now;
		398
		399	# when would the timeout trigger?
		400	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		401
		402	# now or in the past already?
		403	if ($after <= 0) {
		404	$self->{_activity} = $NOW;
		405
		406	if ($self->{on_timeout}) {
		407	$self->{on_timeout}($self);
		408	} else {
		409	$self->_error (&Errno::ETIMEDOUT);
		410	}
		411
		412	# callback could have changed timeout value, optimise
		413	return unless $self->{timeout};
		414
		415	# calculate new after
		416	$after = $self->{timeout};
		417	}
		418
		419	Scalar::Util::weaken $self;
		420	return unless $self; # ->error could have destroyed $self
		421
		422	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		423	delete $self->{_tw};
		424	$self->_timeout;
		425	});
		426	} else {
		427	delete $self->{_tw};
		428	}
		429	}
		430
		431	#############################################################################
		432
		433	=back
		434
		435	=head2 WRITE QUEUE
		436
		437	AnyEvent::Handle manages two queues per handle, one for writing and one
		438	for reading.
		439
		440	The write queue is very simple: you can add data to its end, and
		441	AnyEvent::Handle will automatically try to get rid of it for you.
		442
		443	When data could be written and the write buffer is shorter then the low
		444	water mark, the C<on_drain> callback will be invoked.
		445
		446	=over 4
		447
		448	=item $handle->on_drain ($cb)
		449
		450	Sets the C<on_drain> callback or clears it (see the description of
		451	C<on_drain> in the constructor).
		452
		453	=cut
		454
		455	sub on_drain {
		456	my ($self, $cb) = @_;
		457
		458	$self->{on_drain} = $cb;
		459
		460	$cb->($self)
		461	if $cb && $self->{low_water_mark} >= length $self->{wbuf};
		462	}
		463
		464	=item $handle->push_write ($data)
		465
		466	Queues the given scalar to be written. You can push as much data as you
		467	want (only limited by the available memory), as C<AnyEvent::Handle>
		468	buffers it independently of the kernel.
		469
		470	=cut
		471
		472	sub _drain_wbuf {
		473	my ($self) = @_;
		474
		475	if (!$self->{_ww} && length $self->{wbuf}) {
		476
		477	Scalar::Util::weaken $self;
		478
		479	my $cb = sub {
		480	my $len = syswrite $self->{fh}, $self->{wbuf};
		481
		482	if ($len >= 0) {
		483	substr $self->{wbuf}, 0, $len, "";
		484
		485	$self->{_activity} = AnyEvent->now;
		486
		487	$self->{on_drain}($self)
		488	if $self->{low_water_mark} >= length $self->{wbuf}
		489	&& $self->{on_drain};
		490
		491	delete $self->{_ww} unless length $self->{wbuf};
		492	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		493	$self->_error ($!, 1);
		494	}
		495	};
		496
		497	# try to write data immediately
		498	$cb->() unless $self->{autocork};
		499
		500	# if still data left in wbuf, we need to poll
		501	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
		502	if length $self->{wbuf};
		503	};
		504	}
		505
		506	our %WH;
		507
		508	sub register_write_type($$) {
		509	$WH{$_[0]} = $_[1];
		510	}
		511
		512	sub push_write {
		513	my $self = shift;
		514
		515	if (@_ > 1) {
		516	my $type = shift;
		517
		518	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		519	->($self, @_);
		520	}
		521
		522	if ($self->{filter_w}) {
		523	$self->{filter_w}($self, \$_[0]);
		524	} else {
		525	$self->{wbuf} .= $_[0];
		526	$self->_drain_wbuf;
		527	}
		528	}
		529
		530	=item $handle->push_write (type => @args)
		531
		532	Instead of formatting your data yourself, you can also let this module do
		533	the job by specifying a type and type-specific arguments.
		534
		535	Predefined types are (if you have ideas for additional types, feel free to
		536	drop by and tell us):
		537
		538	=over 4
		539
		540	=item netstring => $string
		541
		542	Formats the given value as netstring
		543	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		544
		545	=cut
		546
		547	register_write_type netstring => sub {
		548	my ($self, $string) = @_;
		549
		550	sprintf "%d:%s,", (length $string), $string
		551	};
		552
		553	=item packstring => $format, $data
		554
		555	An octet string prefixed with an encoded length. The encoding C<$format>
		556	uses the same format as a Perl C<pack> format, but must specify a single
		557	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		558	optional C<!>, C<< < >> or C<< > >> modifier).
		559
		560	=cut
		561
		562	register_write_type packstring => sub {
		563	my ($self, $format, $string) = @_;
		564
		565	pack "$format/a*", $string
		566	};
		567
		568	=item json => $array_or_hashref
		569
		570	Encodes the given hash or array reference into a JSON object. Unless you
		571	provide your own JSON object, this means it will be encoded to JSON text
		572	in UTF-8.
		573
		574	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		575	one end of a handle and read them at the other end without using any
		576	additional framing.
		577
		578	The generated JSON text is guaranteed not to contain any newlines: While
		579	this module doesn't need delimiters after or between JSON texts to be
		580	able to read them, many other languages depend on that.
		581
		582	A simple RPC protocol that interoperates easily with others is to send
		583	JSON arrays (or objects, although arrays are usually the better choice as
		584	they mimic how function argument passing works) and a newline after each
		585	JSON text:
		586
		587	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		588	$handle->push_write ("\012");
		589
		590	An AnyEvent::Handle receiver would simply use the C<json> read type and
		591	rely on the fact that the newline will be skipped as leading whitespace:
		592
		593	$handle->push_read (json => sub { my $array = $_[1]; ... });
		594
		595	Other languages could read single lines terminated by a newline and pass
		596	this line into their JSON decoder of choice.
		597
		598	=cut
		599
		600	register_write_type json => sub {
		601	my ($self, $ref) = @_;
		602
		603	require JSON;
		604
		605	$self->{json} ? $self->{json}->encode ($ref)
		606	: JSON::encode_json ($ref)
		607	};
		608
		609	=item storable => $reference
		610
		611	Freezes the given reference using L<Storable> and writes it to the
		612	handle. Uses the C<nfreeze> format.
		613
		614	=cut
		615
		616	register_write_type storable => sub {
		617	my ($self, $ref) = @_;
		618
		619	require Storable;
		620
		621	pack "w/a*", Storable::nfreeze ($ref)
		622	};
		623
		624	=back
		625
		626	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		627
		628	This function (not method) lets you add your own types to C<push_write>.
		629	Whenever the given C<type> is used, C<push_write> will invoke the code
		630	reference with the handle object and the remaining arguments.
		631
		632	The code reference is supposed to return a single octet string that will
		633	be appended to the write buffer.
		634
		635	Note that this is a function, and all types registered this way will be
		636	global, so try to use unique names.
		637
		638	=cut
		639
		640	#############################################################################
		641
		642	=back
		643
		644	=head2 READ QUEUE
		645
		646	AnyEvent::Handle manages two queues per handle, one for writing and one
		647	for reading.
		648
		649	The read queue is more complex than the write queue. It can be used in two
		650	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		651	a queue.
		652
		653	In the simple case, you just install an C<on_read> callback and whenever
		654	new data arrives, it will be called. You can then remove some data (if
		655	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		656	leave the data there if you want to accumulate more (e.g. when only a
		657	partial message has been received so far).
		658
		659	In the more complex case, you want to queue multiple callbacks. In this
		660	case, AnyEvent::Handle will call the first queued callback each time new
		661	data arrives (also the first time it is queued) and removes it when it has
		662	done its job (see C<push_read>, below).
		663
		664	This way you can, for example, push three line-reads, followed by reading
		665	a chunk of data, and AnyEvent::Handle will execute them in order.
		666
		667	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		668	the specified number of bytes which give an XML datagram.
		669
		670	# in the default state, expect some header bytes
		671	$handle->on_read (sub {
		672	# some data is here, now queue the length-header-read (4 octets)
		673	shift->unshift_read (chunk => 4, sub {
		674	# header arrived, decode
		675	my $len = unpack "N", $_[1];
		676
		677	# now read the payload
		678	shift->unshift_read (chunk => $len, sub {
		679	my $xml = $_[1];
		680	# handle xml
		681	});
		682	});
		683	});
		684
		685	Example 2: Implement a client for a protocol that replies either with "OK"
		686	and another line or "ERROR" for the first request that is sent, and 64
		687	bytes for the second request. Due to the availability of a queue, we can
		688	just pipeline sending both requests and manipulate the queue as necessary
		689	in the callbacks.
		690
		691	When the first callback is called and sees an "OK" response, it will
		692	C<unshift> another line-read. This line-read will be queued I<before> the
		693	64-byte chunk callback.
		694
		695	# request one, returns either "OK + extra line" or "ERROR"
		696	$handle->push_write ("request 1\015\012");
		697
		698	# we expect "ERROR" or "OK" as response, so push a line read
		699	$handle->push_read (line => sub {
		700	# if we got an "OK", we have to _prepend_ another line,
		701	# so it will be read before the second request reads its 64 bytes
		702	# which are already in the queue when this callback is called
		703	# we don't do this in case we got an error
		704	if ($_[1] eq "OK") {
49	on_readline => sub {	705	$_[0]->unshift_read (line => sub {
50	my ($ae_fh, @lines) = @_;	706	my $response = $_[1];
51	for (@lines) {	707	...
52	chomp;	708	});
53	print "Line: $_";	709	}
		710	});
		711
		712	# request two, simply returns 64 octets
		713	$handle->push_write ("request 2\015\012");
		714
		715	# simply read 64 bytes, always
		716	$handle->push_read (chunk => 64, sub {
		717	my $response = $_[1];
		718	...
		719	});
		720
		721	=over 4
		722
		723	=cut
		724
		725	sub _drain_rbuf {
		726	my ($self) = @_;
		727
		728	local $self->{_in_drain} = 1;
		729
		730	if (
		731	defined $self->{rbuf_max}
		732	&& $self->{rbuf_max} < length $self->{rbuf}
		733	) {
		734	return $self->_error (&Errno::ENOSPC, 1);
		735	}
		736
		737	while () {
		738	my $len = length $self->{rbuf};
		739
		740	if (my $cb = shift @{ $self->{_queue} }) {
		741	unless ($cb->($self)) {
		742	if ($self->{_eof}) {
		743	# no progress can be made (not enough data and no data forthcoming)
		744	$self->_error (&Errno::EPIPE, 1), last;
54	}	745	}
		746
		747	unshift @{ $self->{_queue} }, $cb;
		748	last;
55	}	749	}
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}) {	750	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	751	last unless $len;
122		752
		753	$self->{on_read}($self);
		754
		755	if (
		756	$len == length $self->{rbuf} # if no data has been consumed
		757	&& !@{ $self->{_queue} } # and the queue is still empty
		758	&& $self->{on_read} # but we still have on_read
		759	) {
		760	# no further data will arrive
		761	# so no progress can be made
		762	$self->_error (&Errno::EPIPE, 1), last
		763	if $self->{_eof};
		764
		765	last; # more data might arrive
		766	}
		767	} else {
		768	# read side becomes idle
		769	delete $self->{_rw};
		770	last;
		771	}
		772	}
		773
123	} elsif ($self->{on_eof}) {	774	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});
125
126	} elsif ($self->{on_error}) {	775	if ($self->{on_eof}) {
127	$self->on_eof ($self->{on_error});	776	$self->{on_eof}($self)
		777	} else {
		778	$self->_error (0, 1);
		779	}
128	}	780	}
129		781
130	return $self	782	# may need to restart read watcher
		783	unless ($self->{_rw}) {
		784	$self->start_read
		785	if $self->{on_read} || @{ $self->{_queue} };
		786	}
131	}	787	}
132		788
133	=item B<fh>	789	=item $handle->on_read ($cb)
134		790
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	791	This replaces the currently set C<on_read> callback, or clears it (when
136		792	the new callback is C<undef>). See the description of C<on_read> in the
137	=cut	793	constructor.
138
139	sub fh { $_[0]->{fh} }
140
141	=item B<on_read ($callback)>
142
143	This method installs a C<$callback> that will be called
144	when new data arrived. You can access the read buffer via the C<rbuf>
145	method (see below).
146
147	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
148		794
149	=cut	795	=cut
150		796
151	sub on_read {	797	sub on_read {
152	my ($self, $cb) = @_;	798	my ($self, $cb) = @_;
		799
153	$self->{on_read} = $cb;	800	$self->{on_read} = $cb;
		801	$self->_drain_rbuf if $cb && !$self->{_in_drain};
		802	}
154		803
155	unless (defined $self->{on_read}) {	804	=item $handle->rbuf
156	delete $self->{on_read_w};	805
		806	Returns the read buffer (as a modifiable lvalue).
		807
		808	You can access the read buffer directly as the C<< ->{rbuf} >> member, if
		809	you want.
		810
		811	NOTE: The read buffer should only be used or modified if the C<on_read>,
		812	C<push_read> or C<unshift_read> methods are used. The other read methods
		813	automatically manage the read buffer.
		814
		815	=cut
		816
		817	sub rbuf : lvalue {
		818	$_[0]{rbuf}
		819	}
		820
		821	=item $handle->push_read ($cb)
		822
		823	=item $handle->unshift_read ($cb)
		824
		825	Append the given callback to the end of the queue (C<push_read>) or
		826	prepend it (C<unshift_read>).
		827
		828	The callback is called each time some additional read data arrives.
		829
		830	It must check whether enough data is in the read buffer already.
		831
		832	If not enough data is available, it must return the empty list or a false
		833	value, in which case it will be called repeatedly until enough data is
		834	available (or an error condition is detected).
		835
		836	If enough data was available, then the callback must remove all data it is
		837	interested in (which can be none at all) and return a true value. After returning
		838	true, it will be removed from the queue.
		839
		840	=cut
		841
		842	our %RH;
		843
		844	sub register_read_type($$) {
		845	$RH{$_[0]} = $_[1];
		846	}
		847
		848	sub push_read {
		849	my $self = shift;
		850	my $cb = pop;
		851
		852	if (@_) {
		853	my $type = shift;
		854
		855	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		856	->($self, $cb, @_);
		857	}
		858
		859	push @{ $self->{_queue} }, $cb;
		860	$self->_drain_rbuf unless $self->{_in_drain};
		861	}
		862
		863	sub unshift_read {
		864	my $self = shift;
		865	my $cb = pop;
		866
		867	if (@_) {
		868	my $type = shift;
		869
		870	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		871	->($self, $cb, @_);
		872	}
		873
		874
		875	unshift @{ $self->{_queue} }, $cb;
		876	$self->_drain_rbuf unless $self->{_in_drain};
		877	}
		878
		879	=item $handle->push_read (type => @args, $cb)
		880
		881	=item $handle->unshift_read (type => @args, $cb)
		882
		883	Instead of providing a callback that parses the data itself you can chose
		884	between a number of predefined parsing formats, for chunks of data, lines
		885	etc.
		886
		887	Predefined types are (if you have ideas for additional types, feel free to
		888	drop by and tell us):
		889
		890	=over 4
		891
		892	=item chunk => $octets, $cb->($handle, $data)
		893
		894	Invoke the callback only once C<$octets> bytes have been read. Pass the
		895	data read to the callback. The callback will never be called with less
		896	data.
		897
		898	Example: read 2 bytes.
		899
		900	$handle->push_read (chunk => 2, sub {
		901	warn "yay ", unpack "H*", $_[1];
		902	});
		903
		904	=cut
		905
		906	register_read_type chunk => sub {
		907	my ($self, $cb, $len) = @_;
		908
		909	sub {
		910	$len <= length $_[0]{rbuf} or return;
		911	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		912	1
		913	}
		914	};
		915
		916	=item line => [$eol, ]$cb->($handle, $line, $eol)
		917
		918	The callback will be called only once a full line (including the end of
		919	line marker, C<$eol>) has been read. This line (excluding the end of line
		920	marker) will be passed to the callback as second argument (C<$line>), and
		921	the end of line marker as the third argument (C<$eol>).
		922
		923	The end of line marker, C<$eol>, can be either a string, in which case it
		924	will be interpreted as a fixed record end marker, or it can be a regex
		925	object (e.g. created by C<qr>), in which case it is interpreted as a
		926	regular expression.
		927
		928	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		929	undef), then C<qr|\015?\012|> is used (which is good for most internet
		930	protocols).
		931
		932	Partial lines at the end of the stream will never be returned, as they are
		933	not marked by the end of line marker.
		934
		935	=cut
		936
		937	register_read_type line => sub {
		938	my ($self, $cb, $eol) = @_;
		939
		940	if (@_ < 3) {
		941	# this is more than twice as fast as the generic code below
		942	sub {
		943	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		944
		945	$cb->($_[0], $1, $2);
		946	1
		947	}
		948	} else {
		949	$eol = quotemeta $eol unless ref $eol;
		950	$eol = qr|^(.*?)($eol)|s;
		951
		952	sub {
		953	$_[0]{rbuf} =~ s/$eol// or return;
		954
		955	$cb->($_[0], $1, $2);
		956	1
		957	}
		958	}
		959	};
		960
		961	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		962
		963	Makes a regex match against the regex object C<$accept> and returns
		964	everything up to and including the match.
		965
		966	Example: read a single line terminated by '\n'.
		967
		968	$handle->push_read (regex => qr<\n>, sub { ... });
		969
		970	If C<$reject> is given and not undef, then it determines when the data is
		971	to be rejected: it is matched against the data when the C<$accept> regex
		972	does not match and generates an C<EBADMSG> error when it matches. This is
		973	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		974	receive buffer overflow).
		975
		976	Example: expect a single decimal number followed by whitespace, reject
		977	anything else (not the use of an anchor).
		978
		979	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		980
		981	If C<$skip> is given and not C<undef>, then it will be matched against
		982	the receive buffer when neither C<$accept> nor C<$reject> match,
		983	and everything preceding and including the match will be accepted
		984	unconditionally. This is useful to skip large amounts of data that you
		985	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		986	have to start matching from the beginning. This is purely an optimisation
		987	and is usually worth only when you expect more than a few kilobytes.
		988
		989	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		990	expect the header to be very large (it isn't in practise, but...), we use
		991	a skip regex to skip initial portions. The skip regex is tricky in that
		992	it only accepts something not ending in either \015 or \012, as these are
		993	required for the accept regex.
		994
		995	$handle->push_read (regex =>
		996	qr<\015\012\015\012>,
		997	undef, # no reject
		998	qr<^.*[^\015\012]>,
		999	sub { ... });
		1000
		1001	=cut
		1002
		1003	register_read_type regex => sub {
		1004	my ($self, $cb, $accept, $reject, $skip) = @_;
		1005
		1006	my $data;
		1007	my $rbuf = \$self->{rbuf};
		1008
		1009	sub {
		1010	# accept
		1011	if ($$rbuf =~ $accept) {
		1012	$data .= substr $$rbuf, 0, $+[0], "";
		1013	$cb->($self, $data);
157	return;	1014	return 1;
		1015	}
		1016
		1017	# reject
		1018	if ($reject && $$rbuf =~ $reject) {
		1019	$self->_error (&Errno::EBADMSG);
		1020	}
		1021
		1022	# skip
		1023	if ($skip && $$rbuf =~ $skip) {
		1024	$data .= substr $$rbuf, 0, $+[0], "";
		1025	}
		1026
		1027	()
158	}	1028	}
159		1029	};
160	$self->{on_read_w} =	1030
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1031	=item netstring => $cb->($handle, $string)
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1032
163	my $rbuf_len = length $self->{rbuf};	1033	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
164	my $l;	1034
165	if (defined $self->{read_size}) {	1035	Throws an error with C<$!> set to EBADMSG on format violations.
166	$l = sysread $self->{fh}, $self->{rbuf},	1036
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1037	=cut
168	} else {	1038
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1039	register_read_type netstring => sub {
		1040	my ($self, $cb) = @_;
		1041
		1042	sub {
		1043	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1044	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1045	$self->_error (&Errno::EBADMSG);
170	}	1046	}
171	#d# warn "READL $l [$self->{rbuf}]\n";	1047	return;
		1048	}
172		1049
173	if (not defined $l) {	1050	my $len = $1;
174	return if $! == EAGAIN || $! == EINTR;
175	$self->{on_error}->($self) if $self->{on_error};
176	delete $self->{on_read_w};
177		1051
178	} elsif ($l == 0) {	1052	$self->unshift_read (chunk => $len, sub {
179	$self->{on_eof}->($self) if $self->{on_eof};	1053	my $string = $_[1];
180	delete $self->{on_read_w};	1054	$_[0]->unshift_read (chunk => 1, sub {
181		1055	if ($_[1] eq ",") {
		1056	$cb->($_[0], $string);
182	} else {	1057	} else {
183	$self->{on_read}->($self);	1058	$self->_error (&Errno::EBADMSG);
		1059	}
		1060	});
		1061	});
		1062
		1063	1
		1064	}
		1065	};
		1066
		1067	=item packstring => $format, $cb->($handle, $string)
		1068
		1069	An octet string prefixed with an encoded length. The encoding C<$format>
		1070	uses the same format as a Perl C<pack> format, but must specify a single
		1071	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1072	optional C<!>, C<< < >> or C<< > >> modifier).
		1073
		1074	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1075
		1076	Example: read a block of data prefixed by its length in BER-encoded
		1077	format (very efficient).
		1078
		1079	$handle->push_read (packstring => "w", sub {
		1080	my ($handle, $data) = @_;
		1081	});
		1082
		1083	=cut
		1084
		1085	register_read_type packstring => sub {
		1086	my ($self, $cb, $format) = @_;
		1087
		1088	sub {
		1089	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1090	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1091	or return;
		1092
		1093	$format = length pack $format, $len;
		1094
		1095	# bypass unshift if we already have the remaining chunk
		1096	if ($format + $len <= length $_[0]{rbuf}) {
		1097	my $data = substr $_[0]{rbuf}, $format, $len;
		1098	substr $_[0]{rbuf}, 0, $format + $len, "";
		1099	$cb->($_[0], $data);
		1100	} else {
		1101	# remove prefix
		1102	substr $_[0]{rbuf}, 0, $format, "";
		1103
		1104	# read remaining chunk
		1105	$_[0]->unshift_read (chunk => $len, $cb);
		1106	}
		1107
		1108	1
		1109	}
		1110	};
		1111
		1112	=item json => $cb->($handle, $hash_or_arrayref)
		1113
		1114	Reads a JSON object or array, decodes it and passes it to the callback.
		1115
		1116	If a C<json> object was passed to the constructor, then that will be used
		1117	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1118
		1119	This read type uses the incremental parser available with JSON version
		1120	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1121	dependency on your own: this module will load the JSON module, but
		1122	AnyEvent does not depend on it itself.
		1123
		1124	Since JSON texts are fully self-delimiting, the C<json> read and write
		1125	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1126	the C<json> write type description, above, for an actual example.
		1127
		1128	=cut
		1129
		1130	register_read_type json => sub {
		1131	my ($self, $cb) = @_;
		1132
		1133	require JSON;
		1134
		1135	my $data;
		1136	my $rbuf = \$self->{rbuf};
		1137
		1138	my $json = $self->{json} ||= JSON->new->utf8;
		1139
		1140	sub {
		1141	my $ref = $json->incr_parse ($self->{rbuf});
		1142
		1143	if ($ref) {
		1144	$self->{rbuf} = $json->incr_text;
		1145	$json->incr_text = "";
		1146	$cb->($self, $ref);
		1147
		1148	1
		1149	} else {
		1150	$self->{rbuf} = "";
		1151	()
		1152	}
		1153	}
		1154	};
		1155
		1156	=item storable => $cb->($handle, $ref)
		1157
		1158	Deserialises a L<Storable> frozen representation as written by the
		1159	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1160	data).
		1161
		1162	Raises C<EBADMSG> error if the data could not be decoded.
		1163
		1164	=cut
		1165
		1166	register_read_type storable => sub {
		1167	my ($self, $cb) = @_;
		1168
		1169	require Storable;
		1170
		1171	sub {
		1172	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1173	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1174	or return;
		1175
		1176	my $format = length pack "w", $len;
		1177
		1178	# bypass unshift if we already have the remaining chunk
		1179	if ($format + $len <= length $_[0]{rbuf}) {
		1180	my $data = substr $_[0]{rbuf}, $format, $len;
		1181	substr $_[0]{rbuf}, 0, $format + $len, "";
		1182	$cb->($_[0], Storable::thaw ($data));
		1183	} else {
		1184	# remove prefix
		1185	substr $_[0]{rbuf}, 0, $format, "";
		1186
		1187	# read remaining chunk
		1188	$_[0]->unshift_read (chunk => $len, sub {
		1189	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1190	$cb->($_[0], $ref);
		1191	} else {
		1192	$self->_error (&Errno::EBADMSG);
		1193	}
		1194	});
		1195	}
		1196
		1197	1
		1198	}
		1199	};
		1200
		1201	=back
		1202
		1203	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1204
		1205	This function (not method) lets you add your own types to C<push_read>.
		1206
		1207	Whenever the given C<type> is used, C<push_read> will invoke the code
		1208	reference with the handle object, the callback and the remaining
		1209	arguments.
		1210
		1211	The code reference is supposed to return a callback (usually a closure)
		1212	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1213
		1214	It should invoke the passed callback when it is done reading (remember to
		1215	pass C<$handle> as first argument as all other callbacks do that).
		1216
		1217	Note that this is a function, and all types registered this way will be
		1218	global, so try to use unique names.
		1219
		1220	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1221	search for C<register_read_type>)).
		1222
		1223	=item $handle->stop_read
		1224
		1225	=item $handle->start_read
		1226
		1227	In rare cases you actually do not want to read anything from the
		1228	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1229	any queued callbacks will be executed then. To start reading again, call
		1230	C<start_read>.
		1231
		1232	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1233	you change the C<on_read> callback or push/unshift a read callback, and it
		1234	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1235	there are any read requests in the queue.
		1236
		1237	=cut
		1238
		1239	sub stop_read {
		1240	my ($self) = @_;
		1241
		1242	delete $self->{_rw};
		1243	}
		1244
		1245	sub start_read {
		1246	my ($self) = @_;
		1247
		1248	unless ($self->{_rw} || $self->{_eof}) {
		1249	Scalar::Util::weaken $self;
		1250
		1251	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1252	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
		1253	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1254
		1255	if ($len > 0) {
		1256	$self->{_activity} = AnyEvent->now;
		1257
		1258	$self->{filter_r}
		1259	? $self->{filter_r}($self, $rbuf)
		1260	: $self->{_in_drain} || $self->_drain_rbuf;
		1261
		1262	} elsif (defined $len) {
		1263	delete $self->{_rw};
		1264	$self->{_eof} = 1;
		1265	$self->_drain_rbuf unless $self->{_in_drain};
		1266
		1267	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1268	return $self->_error ($!, 1);
184	}	1269	}
185	});	1270	});
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, $len, ''));
252	}
253	});	1271	}
254	}	1272	}
255		1273
256	=item B<readlines ($callback)>	1274	sub _dotls {
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) = @_;	1275	my ($self) = @_;
310		1276
311	if ($self->{write_w}) {	1277	my $buf;
312	unless ($self->{write_cb}) {	1278
313	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {	1279	if (length $self->{_tls_wbuf}) {
314	my $wba = shift @{$self->{write_bufs}};	1280	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
315	$self->{wbuf} .= $wba->[0];	1281	substr $self->{_tls_wbuf}, 0, $len, "";
316	}	1282	}
317	}	1283	}
		1284
		1285	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1286	$self->{wbuf} .= $buf;
		1287	$self->_drain_wbuf;
		1288	}
		1289
		1290	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1291	if (length $buf) {
		1292	$self->{rbuf} .= $buf;
		1293	$self->_drain_rbuf unless $self->{_in_drain};
		1294	} else {
		1295	# let's treat SSL-eof as we treat normal EOF
		1296	$self->{_eof} = 1;
		1297	$self->_shutdown;
318	return;	1298	return;
		1299	}
		1300	}
		1301
		1302	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1303
		1304	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1305	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1306	return $self->_error ($!, 1);
		1307	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1308	return $self->_error (&Errno::EIO, 1);
		1309	}
		1310
		1311	# all others are fine for our purposes
		1312	}
		1313	}
		1314
		1315	=item $handle->starttls ($tls[, $tls_ctx])
		1316
		1317	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1318	object is created, you can also do that at a later time by calling
		1319	C<starttls>.
		1320
		1321	The first argument is the same as the C<tls> constructor argument (either
		1322	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1323
		1324	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1325	used when AnyEvent::Handle has to create its own TLS connection object.
		1326
		1327	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1328	call and can be used or changed to your liking. Note that the handshake
		1329	might have already started when this function returns.
		1330
		1331	=cut
		1332
		1333	sub starttls {
		1334	my ($self, $ssl, $ctx) = @_;
		1335
		1336	$self->stoptls;
		1337
		1338	if ($ssl eq "accept") {
		1339	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1340	Net::SSLeay::set_accept_state ($ssl);
		1341	} elsif ($ssl eq "connect") {
		1342	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1343	Net::SSLeay::set_connect_state ($ssl);
		1344	}
		1345
		1346	$self->{tls} = $ssl;
		1347
		1348	# basically, this is deep magic (because SSL_read should have the same issues)
		1349	# but the openssl maintainers basically said: "trust us, it just works".
		1350	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1351	# and mismaintained ssleay-module doesn't even offer them).
		1352	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1353	Net::SSLeay::CTX_set_mode ($self->{tls},
		1354	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1355	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1356
		1357	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1358	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1359
		1360	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1361
		1362	$self->{filter_w} = sub {
		1363	$_[0]{_tls_wbuf} .= ${$_[1]};
		1364	&_dotls;
319	}	1365	};
320		1366	$self->{filter_r} = sub {
321	my $wba = shift @{$self->{write_bufs}}	1367	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
322	or return;	1368	&_dotls;
323
324	unless (defined $wba->[0]) {
325	$wba->[1]->($self) if $wba->[1];
326	$self->_check_writer;
327	return;
328	}	1369	};
		1370	}
329		1371
330	$self->{wbuf} = $wba->[0];	1372	=item $handle->stoptls
331	$self->{write_cb} = $wba->[1];
332		1373
333	$self->{write_w} =	1374	Destroys the SSL connection, if any. Partial read or write data will be
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1375	lost.
		1376
		1377	=cut
		1378
		1379	sub stoptls {
		1380	my ($self) = @_;
		1381
		1382	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1383
		1384	delete $self->{_rbio};
		1385	delete $self->{_wbio};
		1386	delete $self->{_tls_wbuf};
		1387	delete $self->{filter_r};
		1388	delete $self->{filter_w};
		1389	}
		1390
		1391	sub DESTROY {
		1392	my $self = shift;
		1393
		1394	$self->stoptls;
		1395
		1396	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1397
		1398	if ($linger && length $self->{wbuf}) {
		1399	my $fh = delete $self->{fh};
		1400	my $wbuf = delete $self->{wbuf};
		1401
		1402	my @linger;
		1403
		1404	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1405	my $len = syswrite $fh, $wbuf, length $wbuf;
336		1406
337	if (not defined $l) {	1407	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	1408	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	1409	} else {
343	substr $self->{wbuf}, 0, $l, '';	1410	@linger = (); # end
344
345	if (length ($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	}	1411	}
355	});	1412	});
		1413	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1414	@linger = ();
		1415	});
		1416	}
		1417	}
		1418
		1419	=item AnyEvent::Handle::TLS_CTX
		1420
		1421	This function creates and returns the Net::SSLeay::CTX object used by
		1422	default for TLS mode.
		1423
		1424	The context is created like this:
		1425
		1426	Net::SSLeay::load_error_strings;
		1427	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1428	Net::SSLeay::randomize;
		1429
		1430	my $CTX = Net::SSLeay::CTX_new;
		1431
		1432	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1433
		1434	=cut
		1435
		1436	our $TLS_CTX;
		1437
		1438	sub TLS_CTX() {
		1439	$TLS_CTX || do {
		1440	require Net::SSLeay;
		1441
		1442	Net::SSLeay::load_error_strings ();
		1443	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1444	Net::SSLeay::randomize ();
		1445
		1446	$TLS_CTX = Net::SSLeay::CTX_new ();
		1447
		1448	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1449
		1450	$TLS_CTX
		1451	}
356	}	1452	}
357		1453
358	=back	1454	=back
359		1455
		1456	=head1 SUBCLASSING AnyEvent::Handle
		1457
		1458	In many cases, you might want to subclass AnyEvent::Handle.
		1459
		1460	To make this easier, a given version of AnyEvent::Handle uses these
		1461	conventions:
		1462
		1463	=over 4
		1464
		1465	=item * all constructor arguments become object members.
		1466
		1467	At least initially, when you pass a C<tls>-argument to the constructor it
		1468	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1469	mutated later on (for example C<tls> will hold the TLS connection object).
		1470
		1471	=item * other object member names are prefixed with an C<_>.
		1472
		1473	All object members not explicitly documented (internal use) are prefixed
		1474	with an underscore character, so the remaining non-C<_>-namespace is free
		1475	for use for subclasses.
		1476
		1477	=item * all members not documented here and not prefixed with an underscore
		1478	are free to use in subclasses.
		1479
		1480	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1481	member variables, but thats just life, at least it is documented.
		1482
		1483	=back
		1484
360	=head1 AUTHOR	1485	=head1 AUTHOR
361		1486
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	1487	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363		1488
364	=cut	1489	=cut
365		1490
366	1; # End of AnyEvent::Handle	1491	1; # End of AnyEvent::Handle

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