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Revision 1.2 by elmex, Sun Apr 27 17:27:34 2008 UTC vs.
Revision 1.87 by root, Thu Aug 21 20:52:39 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 = 4.232;
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	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
		57	In the following, when the documentation refers to of "bytes" then this
		58	means characters. As sysread and syswrite are used for all I/O, their
		59	treatment of characters applies to this module as well.
		60
		61	All callbacks will be invoked with the handle object as their first
		62	argument.
		63
		64	=head1 METHODS
		65
		66	=over 4
		67
		68	=item B<new (%args)>
		69
		70	The constructor supports these arguments (all as key => value pairs).
		71
		72	=over 4
		73
		74	=item fh => $filehandle [MANDATORY]
		75
		76	The filehandle this L<AnyEvent::Handle> object will operate on.
		77
		78	NOTE: The filehandle will be set to non-blocking mode (using
		79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
		81
		82	=item on_eof => $cb->($handle)
		83
		84	Set the callback to be called when an end-of-file condition is detected,
		85	i.e. in the case of a socket, when the other side has closed the
		86	connection cleanly.
		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the eof
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
		93	While not mandatory, it is I<highly> recommended to set an eof callback,
		94	otherwise you might end up with a closed socket while you are still
		95	waiting for data.
		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
		99
		100	=item on_error => $cb->($handle, $fatal)
		101
		102	This is the error callback, which is called when, well, some error
		103	occured, such as not being able to resolve the hostname, failure to
		104	connect or a read error.
		105
		106	Some errors are fatal (which is indicated by C<$fatal> being true). On
		107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C< ->rbuf >). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
		111
		112	Non-fatal errors can be retried by simply returning, but it is recommended
		113	to simply ignore this parameter and instead abondon the handle object
		114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		116
		117	On callback entrance, the value of C<$!> contains the operating system
		118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
		119
		120	While not mandatory, it is I<highly> recommended to set this callback, as
		121	you will not be notified of errors otherwise. The default simply calls
		122	C<croak>.
		123
		124	=item on_read => $cb->($handle)
		125
		126	This sets the default read callback, which is called when data arrives
		127	and no read request is in the queue (unlike read queue callbacks, this
		128	callback will only be called when at least one octet of data is in the
		129	read buffer).
		130
		131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		132	method or access the C<$handle->{rbuf}> member directly.
		133
		134	When an EOF condition is detected then AnyEvent::Handle will first try to
		135	feed all the remaining data to the queued callbacks and C<on_read> before
		136	calling the C<on_eof> callback. If no progress can be made, then a fatal
		137	error will be raised (with C<$!> set to C<EPIPE>).
		138
		139	=item on_drain => $cb->($handle)
		140
		141	This sets the callback that is called when the write buffer becomes empty
		142	(or when the callback is set and the buffer is empty already).
		143
		144	To append to the write buffer, use the C<< ->push_write >> method.
		145
		146	This callback is useful when you don't want to put all of your write data
		147	into the queue at once, for example, when you want to write the contents
		148	of some file to the socket you might not want to read the whole file into
		149	memory and push it into the queue, but instead only read more data from
		150	the file when the write queue becomes empty.
		151
		152	=item timeout => $fractional_seconds
		153
		154	If non-zero, then this enables an "inactivity" timeout: whenever this many
		155	seconds pass without a successful read or write on the underlying file
		156	handle, the C<on_timeout> callback will be invoked (and if that one is
		157	missing, an C<ETIMEDOUT> error will be raised).
		158
		159	Note that timeout processing is also active when you currently do not have
		160	any outstanding read or write requests: If you plan to keep the connection
		161	idle then you should disable the timout temporarily or ignore the timeout
		162	in the C<on_timeout> callback.
		163
		164	Zero (the default) disables this timeout.
		165
		166	=item on_timeout => $cb->($handle)
		167
		168	Called whenever the inactivity timeout passes. If you return from this
		169	callback, then the timeout will be reset as if some activity had happened,
		170	so this condition is not fatal in any way.
		171
		172	=item rbuf_max => <bytes>
		173
		174	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		175	when the read buffer ever (strictly) exceeds this size. This is useful to
		176	avoid denial-of-service attacks.
		177
		178	For example, a server accepting connections from untrusted sources should
		179	be configured to accept only so-and-so much data that it cannot act on
		180	(for example, when expecting a line, an attacker could send an unlimited
		181	amount of data without a callback ever being called as long as the line
		182	isn't finished).
		183
		184	=item autocork => <boolean>
		185
		186	When disabled (the default), then C<push_write> will try to immediately
		187	write the data to the handle if possible. This avoids having to register
		188	a write watcher and wait for the next event loop iteration, but can be
		189	inefficient if you write multiple small chunks (this disadvantage is
		190	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		191
		192	When enabled, then writes will always be queued till the next event loop
		193	iteration. This is efficient when you do many small writes per iteration,
		194	but less efficient when you do a single write only.
		195
		196	=item no_delay => <boolean>
		197
		198	When doing small writes on sockets, your operating system kernel might
		199	wait a bit for more data before actually sending it out. This is called
		200	the Nagle algorithm, and usually it is beneficial.
		201
		202	In some situations you want as low a delay as possible, which cna be
		203	accomplishd by setting this option to true.
		204
		205	The default is your opertaing system's default behaviour, this option
		206	explicitly enables or disables it, if possible.
		207
		208	=item read_size => <bytes>
		209
		210	The default read block size (the amount of bytes this module will try to read
		211	during each (loop iteration). Default: C<8192>.
		212
		213	=item low_water_mark => <bytes>
		214
		215	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		216	buffer: If the write reaches this size or gets even samller it is
		217	considered empty.
		218
		219	=item linger => <seconds>
		220
		221	If non-zero (default: C<3600>), then the destructor of the
		222	AnyEvent::Handle object will check wether there is still outstanding write
		223	data and will install a watcher that will write out this data. No errors
		224	will be reported (this mostly matches how the operating system treats
		225	outstanding data at socket close time).
		226
		227	This will not work for partial TLS data that could not yet been
		228	encoded. This data will be lost.
		229
		230	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		231
		232	When this parameter is given, it enables TLS (SSL) mode, that means
		233	AnyEvent will start a TLS handshake and will transparently encrypt/decrypt
		234	data.
		235
		236	TLS mode requires Net::SSLeay to be installed (it will be loaded
		237	automatically when you try to create a TLS handle).
		238
		239	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		240	C<accept>, and for the TLS client side of a connection, use C<connect>
		241	mode.
		242
		243	You can also provide your own TLS connection object, but you have
		244	to make sure that you call either C<Net::SSLeay::set_connect_state>
		245	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		246	AnyEvent::Handle.
		247
		248	See the C<starttls> method for when need to start TLS negotiation later.
		249
		250	=item tls_ctx => $ssl_ctx
		251
		252	Use the given Net::SSLeay::CTX object to create the new TLS connection
		253	(unless a connection object was specified directly). If this parameter is
		254	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		255
		256	=item json => JSON or JSON::XS object
		257
		258	This is the json coder object used by the C<json> read and write types.
		259
		260	If you don't supply it, then AnyEvent::Handle will create and use a
		261	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		262	texts.
		263
		264	Note that you are responsible to depend on the JSON module if you want to
		265	use this functionality, as AnyEvent does not have a dependency itself.
		266
		267	=item filter_r => $cb
		268
		269	=item filter_w => $cb
		270
		271	These exist, but are undocumented at this time. (They are used internally
		272	by the TLS code).
		273
		274	=back
		275
		276	=cut
		277
		278	sub new {
		279	my $class = shift;
		280
		281	my $self = bless { @_ }, $class;
		282
		283	$self->{fh} or Carp::croak "mandatory argument fh is missing";
		284
		285	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		286
		287	if ($self->{tls}) {
		288	require Net::SSLeay;
		289	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		290	}
		291
		292	$self->{_activity} = AnyEvent->now;
		293	$self->_timeout;
		294
		295	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
		296	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		297
		298	$self->start_read
		299	if $self->{on_read};
		300
		301	$self
		302	}
		303
		304	sub _shutdown {
		305	my ($self) = @_;
		306
		307	delete $self->{_tw};
		308	delete $self->{_rw};
		309	delete $self->{_ww};
		310	delete $self->{fh};
		311
		312	$self->stoptls;
		313
		314	delete $self->{on_read};
		315	delete $self->{_queue};
		316	}
		317
		318	sub _error {
		319	my ($self, $errno, $fatal) = @_;
		320
		321	$self->_shutdown
		322	if $fatal;
		323
		324	$! = $errno;
		325
		326	if ($self->{on_error}) {
		327	$self->{on_error}($self, $fatal);
		328	} else {
		329	Carp::croak "AnyEvent::Handle uncaught error: $!";
		330	}
		331	}
		332
		333	=item $fh = $handle->fh
		334
		335	This method returns the file handle of the L<AnyEvent::Handle> object.
		336
		337	=cut
		338
		339	sub fh { $_[0]{fh} }
		340
		341	=item $handle->on_error ($cb)
		342
		343	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		344
		345	=cut
		346
		347	sub on_error {
		348	$_[0]{on_error} = $_[1];
		349	}
		350
		351	=item $handle->on_eof ($cb)
		352
		353	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		354
		355	=cut
		356
		357	sub on_eof {
		358	$_[0]{on_eof} = $_[1];
		359	}
		360
		361	=item $handle->on_timeout ($cb)
		362
		363	Replace the current C<on_timeout> callback, or disables the callback
		364	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		365	argument.
		366
		367	=cut
		368
		369	sub on_timeout {
		370	$_[0]{on_timeout} = $_[1];
		371	}
		372
		373	=item $handle->autocork ($boolean)
		374
		375	Enables or disables the current autocork behaviour (see C<autocork>
		376	constructor argument).
		377
		378	=cut
		379
		380	=item $handle->no_delay ($boolean)
		381
		382	Enables or disables the C<no_delay> setting (see constructor argument of
		383	the same name for details).
		384
		385	=cut
		386
		387	sub no_delay {
		388	$_[0]{no_delay} = $_[1];
		389
		390	eval {
		391	local $SIG{__DIE__};
		392	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		393	};
		394	}
		395
		396	#############################################################################
		397
		398	=item $handle->timeout ($seconds)
		399
		400	Configures (or disables) the inactivity timeout.
		401
		402	=cut
		403
		404	sub timeout {
		405	my ($self, $timeout) = @_;
		406
		407	$self->{timeout} = $timeout;
		408	$self->_timeout;
		409	}
		410
		411	# reset the timeout watcher, as neccessary
		412	# also check for time-outs
		413	sub _timeout {
		414	my ($self) = @_;
		415
		416	if ($self->{timeout}) {
		417	my $NOW = AnyEvent->now;
		418
		419	# when would the timeout trigger?
		420	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		421
		422	# now or in the past already?
		423	if ($after <= 0) {
		424	$self->{_activity} = $NOW;
		425
		426	if ($self->{on_timeout}) {
		427	$self->{on_timeout}($self);
		428	} else {
		429	$self->_error (&Errno::ETIMEDOUT);
		430	}
		431
		432	# callback could have changed timeout value, optimise
		433	return unless $self->{timeout};
		434
		435	# calculate new after
		436	$after = $self->{timeout};
		437	}
		438
		439	Scalar::Util::weaken $self;
		440	return unless $self; # ->error could have destroyed $self
		441
		442	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		443	delete $self->{_tw};
		444	$self->_timeout;
		445	});
		446	} else {
		447	delete $self->{_tw};
		448	}
		449	}
		450
		451	#############################################################################
		452
		453	=back
		454
		455	=head2 WRITE QUEUE
		456
		457	AnyEvent::Handle manages two queues per handle, one for writing and one
		458	for reading.
		459
		460	The write queue is very simple: you can add data to its end, and
		461	AnyEvent::Handle will automatically try to get rid of it for you.
		462
		463	When data could be written and the write buffer is shorter then the low
		464	water mark, the C<on_drain> callback will be invoked.
		465
		466	=over 4
		467
		468	=item $handle->on_drain ($cb)
		469
		470	Sets the C<on_drain> callback or clears it (see the description of
		471	C<on_drain> in the constructor).
		472
		473	=cut
		474
		475	sub on_drain {
		476	my ($self, $cb) = @_;
		477
		478	$self->{on_drain} = $cb;
		479
		480	$cb->($self)
		481	if $cb && $self->{low_water_mark} >= length $self->{wbuf};
		482	}
		483
		484	=item $handle->push_write ($data)
		485
		486	Queues the given scalar to be written. You can push as much data as you
		487	want (only limited by the available memory), as C<AnyEvent::Handle>
		488	buffers it independently of the kernel.
		489
		490	=cut
		491
		492	sub _drain_wbuf {
		493	my ($self) = @_;
		494
		495	if (!$self->{_ww} && length $self->{wbuf}) {
		496
		497	Scalar::Util::weaken $self;
		498
		499	my $cb = sub {
		500	my $len = syswrite $self->{fh}, $self->{wbuf};
		501
		502	if ($len >= 0) {
		503	substr $self->{wbuf}, 0, $len, "";
		504
		505	$self->{_activity} = AnyEvent->now;
		506
		507	$self->{on_drain}($self)
		508	if $self->{low_water_mark} >= length $self->{wbuf}
		509	&& $self->{on_drain};
		510
		511	delete $self->{_ww} unless length $self->{wbuf};
		512	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		513	$self->_error ($!, 1);
		514	}
		515	};
		516
		517	# try to write data immediately
		518	$cb->() unless $self->{autocork};
		519
		520	# if still data left in wbuf, we need to poll
		521	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
		522	if length $self->{wbuf};
		523	};
		524	}
		525
		526	our %WH;
		527
		528	sub register_write_type($$) {
		529	$WH{$_[0]} = $_[1];
		530	}
		531
		532	sub push_write {
		533	my $self = shift;
		534
		535	if (@_ > 1) {
		536	my $type = shift;
		537
		538	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		539	->($self, @_);
		540	}
		541
		542	if ($self->{filter_w}) {
		543	$self->{filter_w}($self, \$_[0]);
		544	} else {
		545	$self->{wbuf} .= $_[0];
		546	$self->_drain_wbuf;
		547	}
		548	}
		549
		550	=item $handle->push_write (type => @args)
		551
		552	Instead of formatting your data yourself, you can also let this module do
		553	the job by specifying a type and type-specific arguments.
		554
		555	Predefined types are (if you have ideas for additional types, feel free to
		556	drop by and tell us):
		557
		558	=over 4
		559
		560	=item netstring => $string
		561
		562	Formats the given value as netstring
		563	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		564
		565	=cut
		566
		567	register_write_type netstring => sub {
		568	my ($self, $string) = @_;
		569
		570	sprintf "%d:%s,", (length $string), $string
		571	};
		572
		573	=item packstring => $format, $data
		574
		575	An octet string prefixed with an encoded length. The encoding C<$format>
		576	uses the same format as a Perl C<pack> format, but must specify a single
		577	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		578	optional C<!>, C<< < >> or C<< > >> modifier).
		579
		580	=cut
		581
		582	register_write_type packstring => sub {
		583	my ($self, $format, $string) = @_;
		584
		585	pack "$format/a*", $string
		586	};
		587
		588	=item json => $array_or_hashref
		589
		590	Encodes the given hash or array reference into a JSON object. Unless you
		591	provide your own JSON object, this means it will be encoded to JSON text
		592	in UTF-8.
		593
		594	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		595	one end of a handle and read them at the other end without using any
		596	additional framing.
		597
		598	The generated JSON text is guaranteed not to contain any newlines: While
		599	this module doesn't need delimiters after or between JSON texts to be
		600	able to read them, many other languages depend on that.
		601
		602	A simple RPC protocol that interoperates easily with others is to send
		603	JSON arrays (or objects, although arrays are usually the better choice as
		604	they mimic how function argument passing works) and a newline after each
		605	JSON text:
		606
		607	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		608	$handle->push_write ("\012");
		609
		610	An AnyEvent::Handle receiver would simply use the C<json> read type and
		611	rely on the fact that the newline will be skipped as leading whitespace:
		612
		613	$handle->push_read (json => sub { my $array = $_[1]; ... });
		614
		615	Other languages could read single lines terminated by a newline and pass
		616	this line into their JSON decoder of choice.
		617
		618	=cut
		619
		620	register_write_type json => sub {
		621	my ($self, $ref) = @_;
		622
		623	require JSON;
		624
		625	$self->{json} ? $self->{json}->encode ($ref)
		626	: JSON::encode_json ($ref)
		627	};
		628
		629	=item storable => $reference
		630
		631	Freezes the given reference using L<Storable> and writes it to the
		632	handle. Uses the C<nfreeze> format.
		633
		634	=cut
		635
		636	register_write_type storable => sub {
		637	my ($self, $ref) = @_;
		638
		639	require Storable;
		640
		641	pack "w/a*", Storable::nfreeze ($ref)
		642	};
		643
		644	=back
		645
		646	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		647
		648	This function (not method) lets you add your own types to C<push_write>.
		649	Whenever the given C<type> is used, C<push_write> will invoke the code
		650	reference with the handle object and the remaining arguments.
		651
		652	The code reference is supposed to return a single octet string that will
		653	be appended to the write buffer.
		654
		655	Note that this is a function, and all types registered this way will be
		656	global, so try to use unique names.
		657
		658	=cut
		659
		660	#############################################################################
		661
		662	=back
		663
		664	=head2 READ QUEUE
		665
		666	AnyEvent::Handle manages two queues per handle, one for writing and one
		667	for reading.
		668
		669	The read queue is more complex than the write queue. It can be used in two
		670	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		671	a queue.
		672
		673	In the simple case, you just install an C<on_read> callback and whenever
		674	new data arrives, it will be called. You can then remove some data (if
		675	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		676	leave the data there if you want to accumulate more (e.g. when only a
		677	partial message has been received so far).
		678
		679	In the more complex case, you want to queue multiple callbacks. In this
		680	case, AnyEvent::Handle will call the first queued callback each time new
		681	data arrives (also the first time it is queued) and removes it when it has
		682	done its job (see C<push_read>, below).
		683
		684	This way you can, for example, push three line-reads, followed by reading
		685	a chunk of data, and AnyEvent::Handle will execute them in order.
		686
		687	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		688	the specified number of bytes which give an XML datagram.
		689
		690	# in the default state, expect some header bytes
		691	$handle->on_read (sub {
		692	# some data is here, now queue the length-header-read (4 octets)
		693	shift->unshift_read (chunk => 4, sub {
		694	# header arrived, decode
		695	my $len = unpack "N", $_[1];
		696
		697	# now read the payload
		698	shift->unshift_read (chunk => $len, sub {
		699	my $xml = $_[1];
		700	# handle xml
		701	});
		702	});
		703	});
		704
		705	Example 2: Implement a client for a protocol that replies either with "OK"
		706	and another line or "ERROR" for the first request that is sent, and 64
		707	bytes for the second request. Due to the availability of a queue, we can
		708	just pipeline sending both requests and manipulate the queue as necessary
		709	in the callbacks.
		710
		711	When the first callback is called and sees an "OK" response, it will
		712	C<unshift> another line-read. This line-read will be queued I<before> the
		713	64-byte chunk callback.
		714
		715	# request one, returns either "OK + extra line" or "ERROR"
		716	$handle->push_write ("request 1\015\012");
		717
		718	# we expect "ERROR" or "OK" as response, so push a line read
		719	$handle->push_read (line => sub {
		720	# if we got an "OK", we have to _prepend_ another line,
		721	# so it will be read before the second request reads its 64 bytes
		722	# which are already in the queue when this callback is called
		723	# we don't do this in case we got an error
		724	if ($_[1] eq "OK") {
49	on_readline => sub {	725	$_[0]->unshift_read (line => sub {
50	my ($ae_fh, @lines) = @_;	726	my $response = $_[1];
51	for (@lines) {	727	...
52	chomp;	728	});
53	print "Line: $_";	729	}
		730	});
		731
		732	# request two, simply returns 64 octets
		733	$handle->push_write ("request 2\015\012");
		734
		735	# simply read 64 bytes, always
		736	$handle->push_read (chunk => 64, sub {
		737	my $response = $_[1];
		738	...
		739	});
		740
		741	=over 4
		742
		743	=cut
		744
		745	sub _drain_rbuf {
		746	my ($self) = @_;
		747
		748	local $self->{_in_drain} = 1;
		749
		750	if (
		751	defined $self->{rbuf_max}
		752	&& $self->{rbuf_max} < length $self->{rbuf}
		753	) {
		754	$self->_error (&Errno::ENOSPC, 1), return;
		755	}
		756
		757	while () {
		758	my $len = length $self->{rbuf};
		759
		760	if (my $cb = shift @{ $self->{_queue} }) {
		761	unless ($cb->($self)) {
		762	if ($self->{_eof}) {
		763	# no progress can be made (not enough data and no data forthcoming)
		764	$self->_error (&Errno::EPIPE, 1), return;
54	}	765	}
		766
		767	unshift @{ $self->{_queue} }, $cb;
		768	last;
55	}	769	}
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}) {	770	} elsif ($self->{on_read}) {
121	$self->readlines ($self->{on_readline});	771	last unless $len;
122		772
		773	$self->{on_read}($self);
		774
		775	if (
		776	$len == length $self->{rbuf} # if no data has been consumed
		777	&& !@{ $self->{_queue} } # and the queue is still empty
		778	&& $self->{on_read} # but we still have on_read
		779	) {
		780	# no further data will arrive
		781	# so no progress can be made
		782	$self->_error (&Errno::EPIPE, 1), return
		783	if $self->{_eof};
		784
		785	last; # more data might arrive
		786	}
		787	} else {
		788	# read side becomes idle
		789	delete $self->{_rw};
		790	last;
		791	}
		792	}
		793
123	} elsif ($self->{on_eof}) {	794	if ($self->{_eof}) {
124	$self->on_eof ($self->{on_eof});
125
126	} elsif ($self->{on_error}) {	795	if ($self->{on_eof}) {
127	$self->on_eof ($self->{on_error});	796	$self->{on_eof}($self)
		797	} else {
		798	$self->_error (0, 1);
		799	}
128	}	800	}
129		801
130	return $self	802	# may need to restart read watcher
		803	unless ($self->{_rw}) {
		804	$self->start_read
		805	if $self->{on_read} || @{ $self->{_queue} };
		806	}
131	}	807	}
132		808
133	=item B<fh>	809	=item $handle->on_read ($cb)
134		810
135	This method returns the filehandle of the L<AnyEvent::Handle> object.	811	This replaces the currently set C<on_read> callback, or clears it (when
136		812	the new callback is C<undef>). See the description of C<on_read> in the
137	=cut	813	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		814
149	=cut	815	=cut
150		816
151	sub on_read {	817	sub on_read {
152	my ($self, $cb) = @_;	818	my ($self, $cb) = @_;
		819
153	$self->{on_read} = $cb;	820	$self->{on_read} = $cb;
		821	$self->_drain_rbuf if $cb && !$self->{_in_drain};
		822	}
154		823
155	unless (defined $self->{on_read}) {	824	=item $handle->rbuf
156	delete $self->{on_read_w};	825
		826	Returns the read buffer (as a modifiable lvalue).
		827
		828	You can access the read buffer directly as the C<< ->{rbuf} >> member, if
		829	you want.
		830
		831	NOTE: The read buffer should only be used or modified if the C<on_read>,
		832	C<push_read> or C<unshift_read> methods are used. The other read methods
		833	automatically manage the read buffer.
		834
		835	=cut
		836
		837	sub rbuf : lvalue {
		838	$_[0]{rbuf}
		839	}
		840
		841	=item $handle->push_read ($cb)
		842
		843	=item $handle->unshift_read ($cb)
		844
		845	Append the given callback to the end of the queue (C<push_read>) or
		846	prepend it (C<unshift_read>).
		847
		848	The callback is called each time some additional read data arrives.
		849
		850	It must check whether enough data is in the read buffer already.
		851
		852	If not enough data is available, it must return the empty list or a false
		853	value, in which case it will be called repeatedly until enough data is
		854	available (or an error condition is detected).
		855
		856	If enough data was available, then the callback must remove all data it is
		857	interested in (which can be none at all) and return a true value. After returning
		858	true, it will be removed from the queue.
		859
		860	=cut
		861
		862	our %RH;
		863
		864	sub register_read_type($$) {
		865	$RH{$_[0]} = $_[1];
		866	}
		867
		868	sub push_read {
		869	my $self = shift;
		870	my $cb = pop;
		871
		872	if (@_) {
		873	my $type = shift;
		874
		875	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		876	->($self, $cb, @_);
		877	}
		878
		879	push @{ $self->{_queue} }, $cb;
		880	$self->_drain_rbuf unless $self->{_in_drain};
		881	}
		882
		883	sub unshift_read {
		884	my $self = shift;
		885	my $cb = pop;
		886
		887	if (@_) {
		888	my $type = shift;
		889
		890	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		891	->($self, $cb, @_);
		892	}
		893
		894
		895	unshift @{ $self->{_queue} }, $cb;
		896	$self->_drain_rbuf unless $self->{_in_drain};
		897	}
		898
		899	=item $handle->push_read (type => @args, $cb)
		900
		901	=item $handle->unshift_read (type => @args, $cb)
		902
		903	Instead of providing a callback that parses the data itself you can chose
		904	between a number of predefined parsing formats, for chunks of data, lines
		905	etc.
		906
		907	Predefined types are (if you have ideas for additional types, feel free to
		908	drop by and tell us):
		909
		910	=over 4
		911
		912	=item chunk => $octets, $cb->($handle, $data)
		913
		914	Invoke the callback only once C<$octets> bytes have been read. Pass the
		915	data read to the callback. The callback will never be called with less
		916	data.
		917
		918	Example: read 2 bytes.
		919
		920	$handle->push_read (chunk => 2, sub {
		921	warn "yay ", unpack "H*", $_[1];
		922	});
		923
		924	=cut
		925
		926	register_read_type chunk => sub {
		927	my ($self, $cb, $len) = @_;
		928
		929	sub {
		930	$len <= length $_[0]{rbuf} or return;
		931	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		932	1
		933	}
		934	};
		935
		936	=item line => [$eol, ]$cb->($handle, $line, $eol)
		937
		938	The callback will be called only once a full line (including the end of
		939	line marker, C<$eol>) has been read. This line (excluding the end of line
		940	marker) will be passed to the callback as second argument (C<$line>), and
		941	the end of line marker as the third argument (C<$eol>).
		942
		943	The end of line marker, C<$eol>, can be either a string, in which case it
		944	will be interpreted as a fixed record end marker, or it can be a regex
		945	object (e.g. created by C<qr>), in which case it is interpreted as a
		946	regular expression.
		947
		948	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		949	undef), then C<qr|\015?\012|> is used (which is good for most internet
		950	protocols).
		951
		952	Partial lines at the end of the stream will never be returned, as they are
		953	not marked by the end of line marker.
		954
		955	=cut
		956
		957	register_read_type line => sub {
		958	my ($self, $cb, $eol) = @_;
		959
		960	if (@_ < 3) {
		961	# this is more than twice as fast as the generic code below
		962	sub {
		963	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		964
		965	$cb->($_[0], $1, $2);
		966	1
		967	}
		968	} else {
		969	$eol = quotemeta $eol unless ref $eol;
		970	$eol = qr|^(.*?)($eol)|s;
		971
		972	sub {
		973	$_[0]{rbuf} =~ s/$eol// or return;
		974
		975	$cb->($_[0], $1, $2);
		976	1
		977	}
		978	}
		979	};
		980
		981	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		982
		983	Makes a regex match against the regex object C<$accept> and returns
		984	everything up to and including the match.
		985
		986	Example: read a single line terminated by '\n'.
		987
		988	$handle->push_read (regex => qr<\n>, sub { ... });
		989
		990	If C<$reject> is given and not undef, then it determines when the data is
		991	to be rejected: it is matched against the data when the C<$accept> regex
		992	does not match and generates an C<EBADMSG> error when it matches. This is
		993	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		994	receive buffer overflow).
		995
		996	Example: expect a single decimal number followed by whitespace, reject
		997	anything else (not the use of an anchor).
		998
		999	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1000
		1001	If C<$skip> is given and not C<undef>, then it will be matched against
		1002	the receive buffer when neither C<$accept> nor C<$reject> match,
		1003	and everything preceding and including the match will be accepted
		1004	unconditionally. This is useful to skip large amounts of data that you
		1005	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1006	have to start matching from the beginning. This is purely an optimisation
		1007	and is usually worth only when you expect more than a few kilobytes.
		1008
		1009	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1010	expect the header to be very large (it isn't in practise, but...), we use
		1011	a skip regex to skip initial portions. The skip regex is tricky in that
		1012	it only accepts something not ending in either \015 or \012, as these are
		1013	required for the accept regex.
		1014
		1015	$handle->push_read (regex =>
		1016	qr<\015\012\015\012>,
		1017	undef, # no reject
		1018	qr<^.*[^\015\012]>,
		1019	sub { ... });
		1020
		1021	=cut
		1022
		1023	register_read_type regex => sub {
		1024	my ($self, $cb, $accept, $reject, $skip) = @_;
		1025
		1026	my $data;
		1027	my $rbuf = \$self->{rbuf};
		1028
		1029	sub {
		1030	# accept
		1031	if ($$rbuf =~ $accept) {
		1032	$data .= substr $$rbuf, 0, $+[0], "";
		1033	$cb->($self, $data);
157	return;	1034	return 1;
		1035	}
		1036
		1037	# reject
		1038	if ($reject && $$rbuf =~ $reject) {
		1039	$self->_error (&Errno::EBADMSG);
		1040	}
		1041
		1042	# skip
		1043	if ($skip && $$rbuf =~ $skip) {
		1044	$data .= substr $$rbuf, 0, $+[0], "";
		1045	}
		1046
		1047	()
158	}	1048	}
159		1049	};
160	$self->{on_read_w} =	1050
161	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1051	=item netstring => $cb->($handle, $string)
162	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1052
163	my $rbuf_len = length $self->{rbuf};	1053	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
164	my $l;	1054
165	if (defined $self->{read_size}) {	1055	Throws an error with C<$!> set to EBADMSG on format violations.
166	$l = sysread $self->{fh}, $self->{rbuf},	1056
167	($self->{read_size} - $rbuf_len), $rbuf_len;	1057	=cut
168	} else {	1058
169	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1059	register_read_type netstring => sub {
		1060	my ($self, $cb) = @_;
		1061
		1062	sub {
		1063	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1064	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1065	$self->_error (&Errno::EBADMSG);
170	}	1066	}
171	#d# warn "READL $l [$self->{rbuf}]\n";	1067	return;
		1068	}
172		1069
173	if (not defined $l) {	1070	my $len = $1;
174	return if $! == EAGAIN || $! == EINTR;
175	$self->{on_error}->($self) if $self->{on_error};
176	delete $self->{on_read_w};
177		1071
178	} elsif ($l == 0) {	1072	$self->unshift_read (chunk => $len, sub {
179	$self->{on_eof}->($self) if $self->{on_eof};	1073	my $string = $_[1];
180	delete $self->{on_read_w};	1074	$_[0]->unshift_read (chunk => 1, sub {
181		1075	if ($_[1] eq ",") {
		1076	$cb->($_[0], $string);
182	} else {	1077	} else {
183	$self->{on_read}->($self);	1078	$self->_error (&Errno::EBADMSG);
		1079	}
		1080	});
		1081	});
		1082
		1083	1
		1084	}
		1085	};
		1086
		1087	=item packstring => $format, $cb->($handle, $string)
		1088
		1089	An octet string prefixed with an encoded length. The encoding C<$format>
		1090	uses the same format as a Perl C<pack> format, but must specify a single
		1091	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1092	optional C<!>, C<< < >> or C<< > >> modifier).
		1093
		1094	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1095
		1096	Example: read a block of data prefixed by its length in BER-encoded
		1097	format (very efficient).
		1098
		1099	$handle->push_read (packstring => "w", sub {
		1100	my ($handle, $data) = @_;
		1101	});
		1102
		1103	=cut
		1104
		1105	register_read_type packstring => sub {
		1106	my ($self, $cb, $format) = @_;
		1107
		1108	sub {
		1109	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1110	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1111	or return;
		1112
		1113	$format = length pack $format, $len;
		1114
		1115	# bypass unshift if we already have the remaining chunk
		1116	if ($format + $len <= length $_[0]{rbuf}) {
		1117	my $data = substr $_[0]{rbuf}, $format, $len;
		1118	substr $_[0]{rbuf}, 0, $format + $len, "";
		1119	$cb->($_[0], $data);
		1120	} else {
		1121	# remove prefix
		1122	substr $_[0]{rbuf}, 0, $format, "";
		1123
		1124	# read remaining chunk
		1125	$_[0]->unshift_read (chunk => $len, $cb);
		1126	}
		1127
		1128	1
		1129	}
		1130	};
		1131
		1132	=item json => $cb->($handle, $hash_or_arrayref)
		1133
		1134	Reads a JSON object or array, decodes it and passes it to the callback.
		1135
		1136	If a C<json> object was passed to the constructor, then that will be used
		1137	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1138
		1139	This read type uses the incremental parser available with JSON version
		1140	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1141	dependency on your own: this module will load the JSON module, but
		1142	AnyEvent does not depend on it itself.
		1143
		1144	Since JSON texts are fully self-delimiting, the C<json> read and write
		1145	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1146	the C<json> write type description, above, for an actual example.
		1147
		1148	=cut
		1149
		1150	register_read_type json => sub {
		1151	my ($self, $cb) = @_;
		1152
		1153	require JSON;
		1154
		1155	my $data;
		1156	my $rbuf = \$self->{rbuf};
		1157
		1158	my $json = $self->{json} ||= JSON->new->utf8;
		1159
		1160	sub {
		1161	my $ref = $json->incr_parse ($self->{rbuf});
		1162
		1163	if ($ref) {
		1164	$self->{rbuf} = $json->incr_text;
		1165	$json->incr_text = "";
		1166	$cb->($self, $ref);
		1167
		1168	1
		1169	} else {
		1170	$self->{rbuf} = "";
		1171	()
		1172	}
		1173	}
		1174	};
		1175
		1176	=item storable => $cb->($handle, $ref)
		1177
		1178	Deserialises a L<Storable> frozen representation as written by the
		1179	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1180	data).
		1181
		1182	Raises C<EBADMSG> error if the data could not be decoded.
		1183
		1184	=cut
		1185
		1186	register_read_type storable => sub {
		1187	my ($self, $cb) = @_;
		1188
		1189	require Storable;
		1190
		1191	sub {
		1192	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1193	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1194	or return;
		1195
		1196	my $format = length pack "w", $len;
		1197
		1198	# bypass unshift if we already have the remaining chunk
		1199	if ($format + $len <= length $_[0]{rbuf}) {
		1200	my $data = substr $_[0]{rbuf}, $format, $len;
		1201	substr $_[0]{rbuf}, 0, $format + $len, "";
		1202	$cb->($_[0], Storable::thaw ($data));
		1203	} else {
		1204	# remove prefix
		1205	substr $_[0]{rbuf}, 0, $format, "";
		1206
		1207	# read remaining chunk
		1208	$_[0]->unshift_read (chunk => $len, sub {
		1209	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1210	$cb->($_[0], $ref);
		1211	} else {
		1212	$self->_error (&Errno::EBADMSG);
		1213	}
		1214	});
		1215	}
		1216
		1217	1
		1218	}
		1219	};
		1220
		1221	=back
		1222
		1223	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1224
		1225	This function (not method) lets you add your own types to C<push_read>.
		1226
		1227	Whenever the given C<type> is used, C<push_read> will invoke the code
		1228	reference with the handle object, the callback and the remaining
		1229	arguments.
		1230
		1231	The code reference is supposed to return a callback (usually a closure)
		1232	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1233
		1234	It should invoke the passed callback when it is done reading (remember to
		1235	pass C<$handle> as first argument as all other callbacks do that).
		1236
		1237	Note that this is a function, and all types registered this way will be
		1238	global, so try to use unique names.
		1239
		1240	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1241	search for C<register_read_type>)).
		1242
		1243	=item $handle->stop_read
		1244
		1245	=item $handle->start_read
		1246
		1247	In rare cases you actually do not want to read anything from the
		1248	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1249	any queued callbacks will be executed then. To start reading again, call
		1250	C<start_read>.
		1251
		1252	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1253	you change the C<on_read> callback or push/unshift a read callback, and it
		1254	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1255	there are any read requests in the queue.
		1256
		1257	=cut
		1258
		1259	sub stop_read {
		1260	my ($self) = @_;
		1261
		1262	delete $self->{_rw};
		1263	}
		1264
		1265	sub start_read {
		1266	my ($self) = @_;
		1267
		1268	unless ($self->{_rw} || $self->{_eof}) {
		1269	Scalar::Util::weaken $self;
		1270
		1271	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1272	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
		1273	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1274
		1275	if ($len > 0) {
		1276	$self->{_activity} = AnyEvent->now;
		1277
		1278	$self->{filter_r}
		1279	? $self->{filter_r}($self, $rbuf)
		1280	: $self->{_in_drain} || $self->_drain_rbuf;
		1281
		1282	} elsif (defined $len) {
		1283	delete $self->{_rw};
		1284	$self->{_eof} = 1;
		1285	$self->_drain_rbuf unless $self->{_in_drain};
		1286
		1287	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1288	return $self->_error ($!, 1);
184	}	1289	}
185	});	1290	});
		1291	}
186	}	1292	}
187		1293
188	=item B<on_error ($callback)>	1294	sub _dotls {
189
190	Whenever a read or write operation resulted in an error the C<$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, $cb) = @_;	1295	my ($self) = @_;
240		1296
241	$self->{read_cb} = $cb;	1297	my $buf;
242	my $old_blk_size = $self->{read_block_size};
243	$self->{read_block_size} = $len;
244		1298
245	$self->on_read (sub {	1299	if (length $self->{_tls_wbuf}) {
246	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";	1300	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
247		1301	substr $self->{_tls_wbuf}, 0, $len, "";
248	if ($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, $len, ''));
252	}	1302	}
		1303	}
		1304
		1305	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1306	$self->{wbuf} .= $buf;
		1307	$self->_drain_wbuf;
		1308	}
		1309
		1310	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1311	if (length $buf) {
		1312	$self->{rbuf} .= $buf;
		1313	$self->_drain_rbuf unless $self->{_in_drain};
		1314	} else {
		1315	# let's treat SSL-eof as we treat normal EOF
		1316	$self->{_eof} = 1;
		1317	$self->_shutdown;
		1318	return;
		1319	}
		1320	}
		1321
		1322	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1323
		1324	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1325	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1326	return $self->_error ($!, 1);
		1327	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1328	return $self->_error (&Errno::EIO, 1);
		1329	}
		1330
		1331	# all others are fine for our purposes
		1332	}
		1333	}
		1334
		1335	=item $handle->starttls ($tls[, $tls_ctx])
		1336
		1337	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1338	object is created, you can also do that at a later time by calling
		1339	C<starttls>.
		1340
		1341	The first argument is the same as the C<tls> constructor argument (either
		1342	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1343
		1344	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1345	used when AnyEvent::Handle has to create its own TLS connection object.
		1346
		1347	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1348	call and can be used or changed to your liking. Note that the handshake
		1349	might have already started when this function returns.
		1350
		1351	=cut
		1352
		1353	sub starttls {
		1354	my ($self, $ssl, $ctx) = @_;
		1355
		1356	$self->stoptls;
		1357
		1358	if ($ssl eq "accept") {
		1359	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1360	Net::SSLeay::set_accept_state ($ssl);
		1361	} elsif ($ssl eq "connect") {
		1362	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1363	Net::SSLeay::set_connect_state ($ssl);
		1364	}
		1365
		1366	$self->{tls} = $ssl;
		1367
		1368	# basically, this is deep magic (because SSL_read should have the same issues)
		1369	# but the openssl maintainers basically said: "trust us, it just works".
		1370	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1371	# and mismaintained ssleay-module doesn't even offer them).
		1372	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1373	#
		1374	# in short: this is a mess.
		1375	#
		1376	# note that we do not try to kepe the length constant between writes as we are required to do.
		1377	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1378	# and we drive openssl fully in blocking mode here.
		1379	Net::SSLeay::CTX_set_mode ($self->{tls},
		1380	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1381	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1382
		1383	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1384	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1385
		1386	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1387
		1388	$self->{filter_w} = sub {
		1389	$_[0]{_tls_wbuf} .= ${$_[1]};
		1390	&_dotls;
253	});	1391	};
254	}	1392	$self->{filter_r} = sub {
255		1393	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
256	=item B<readlines ($callback)>	1394	&_dotls;
257
258	=item B<readlines ($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	});	1395	};
287	}	1396	}
288		1397
289	=item B<write ($data)>	1398	=item $handle->stoptls
290		1399
291	=item B<write ($callback)>	1400	Destroys the SSL connection, if any. Partial read or write data will be
		1401	lost.
292		1402
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	1403	=cut
300		1404
301	sub write {	1405	sub stoptls {
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) = @_;	1406	my ($self) = @_;
310		1407
311	if ($self->{write_w}) {	1408	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
312	unless ($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];
316	}
317	}
318	return;
319	}
320		1409
321	my $wba = shift @{$self->{write_bufs}}	1410	delete $self->{_rbio};
322	or return;	1411	delete $self->{_wbio};
		1412	delete $self->{_tls_wbuf};
		1413	delete $self->{filter_r};
		1414	delete $self->{filter_w};
		1415	}
323		1416
324	unless (defined $wba->[0]) {	1417	sub DESTROY {
325	$wba->[1]->($self) if $wba->[1];	1418	my $self = shift;
326	$self->_check_writer;
327	return;
328	}
329		1419
330	$self->{wbuf} = $wba->[0];	1420	$self->stoptls;
331	$self->{write_cb} = $wba->[1];
332		1421
333	$self->{write_w} =	1422	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
334	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1423
		1424	if ($linger && length $self->{wbuf}) {
		1425	my $fh = delete $self->{fh};
		1426	my $wbuf = delete $self->{wbuf};
		1427
		1428	my @linger;
		1429
		1430	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
335	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1431	my $len = syswrite $fh, $wbuf, length $wbuf;
336		1432
337	if (not defined $l) {	1433	if ($len > 0) {
338	return if $! == EAGAIN || $! == EINTR;	1434	substr $wbuf, 0, $len, "";
339	delete $self->{write_w};
340	$self->{on_error}->($self) if $self->{on_error};
341
342	} else {	1435	} else {
343	substr $self->{wbuf}, 0, $l, '';	1436	@linger = (); # end
344
345	if (length ($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	}	1437	}
355	});	1438	});
		1439	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1440	@linger = ();
		1441	});
		1442	}
		1443	}
		1444
		1445	=item AnyEvent::Handle::TLS_CTX
		1446
		1447	This function creates and returns the Net::SSLeay::CTX object used by
		1448	default for TLS mode.
		1449
		1450	The context is created like this:
		1451
		1452	Net::SSLeay::load_error_strings;
		1453	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1454	Net::SSLeay::randomize;
		1455
		1456	my $CTX = Net::SSLeay::CTX_new;
		1457
		1458	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1459
		1460	=cut
		1461
		1462	our $TLS_CTX;
		1463
		1464	sub TLS_CTX() {
		1465	$TLS_CTX || do {
		1466	require Net::SSLeay;
		1467
		1468	Net::SSLeay::load_error_strings ();
		1469	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1470	Net::SSLeay::randomize ();
		1471
		1472	$TLS_CTX = Net::SSLeay::CTX_new ();
		1473
		1474	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1475
		1476	$TLS_CTX
		1477	}
356	}	1478	}
357		1479
358	=back	1480	=back
359		1481
		1482	=head1 SUBCLASSING AnyEvent::Handle
		1483
		1484	In many cases, you might want to subclass AnyEvent::Handle.
		1485
		1486	To make this easier, a given version of AnyEvent::Handle uses these
		1487	conventions:
		1488
		1489	=over 4
		1490
		1491	=item * all constructor arguments become object members.
		1492
		1493	At least initially, when you pass a C<tls>-argument to the constructor it
		1494	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1495	mutated later on (for example C<tls> will hold the TLS connection object).
		1496
		1497	=item * other object member names are prefixed with an C<_>.
		1498
		1499	All object members not explicitly documented (internal use) are prefixed
		1500	with an underscore character, so the remaining non-C<_>-namespace is free
		1501	for use for subclasses.
		1502
		1503	=item * all members not documented here and not prefixed with an underscore
		1504	are free to use in subclasses.
		1505
		1506	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1507	member variables, but thats just life, at least it is documented.
		1508
		1509	=back
		1510
360	=head1 AUTHOR	1511	=head1 AUTHOR
361		1512
362	Robin Redeker, C<< <elmex at ta-sa.org> >>	1513	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
363
364	=head1 BUGS
365
366	Please report any bugs or feature requests to
367	C<bug-io-anyevent at rt.cpan.org>, or through the web interface at
368	L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=IO-AnyEvent>.
369	I will be notified, and then you'll automatically be notified of progress on
370	your bug as I make changes.
371
372	=head1 SUPPORT
373
374	You can find documentation for this module with the perldoc command.
375
376	perldoc AnyEvent::Handle
377
378	You can also look for information at:
379
380	=over 4
381
382	=item * AnnoCPAN: Annotated CPAN documentation
383
384	L<http://annocpan.org/dist/IO-AnyEvent>
385
386	=item * CPAN Ratings
387
388	L<http://cpanratings.perl.org/d/IO-AnyEvent>
389
390	=item * RT: CPAN's request tracker
391
392	L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=IO-AnyEvent>
393
394	=item * Search CPAN
395
396	L<http://search.cpan.org/dist/IO-AnyEvent>
397
398	=back
399
400	=head1 ACKNOWLEDGEMENTS
401
402	=head1 COPYRIGHT & LICENSE
403
404	Copyright 2008 Robin Redeker, all rights reserved.
405
406	This program is free software; you can redistribute it and/or modify it
407	under the same terms as Perl itself.
408		1514
409	=cut	1515	=cut
410		1516
411	1; # End of AnyEvent::Handle	1517	1; # End of AnyEvent::Handle

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