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Revision 1.1 by elmex, Sun Apr 27 16:56:17 2008 UTC vs.
Revision 1.91 by root, Wed Oct 1 07:40:39 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 = 4.3;
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 =
		29	AnyEvent::Handle->new (
		30	fh => \*STDIN,
		31	on_eof => sub {
		32	$cv->broadcast;
		33	},
		34	);
30		35
31	$ae_fh->readlines (sub {	36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
32	my ($ae_fh, @lines) = @_;	41	my ($handle, $line) = @_;
33	for (@lines) {	42	warn "read line <$line>\n";
34	chomp;	43	$cv->send;
35	print "Line: $_";	44	});
		45
		46	$cv->recv;
		47
		48	=head1 DESCRIPTION
		49
		50	This module is a helper module to make it easier to do event-based I/O on
		51	filehandles. For utility functions for doing non-blocking connects and accepts
		52	on sockets see L<AnyEvent::Util>.
		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
		57	In the following, when the documentation refers to of "bytes" then this
		58	means characters. As sysread and syswrite are used for all I/O, their
		59	treatment of characters applies to this module as well.
		60
		61	All callbacks will be invoked with the handle object as their first
		62	argument.
		63
		64	=head2 SIGPIPE is not handled by this module
		65
		66	SIGPIPE is not handled by this module, so one of the practical
		67	requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} =
		68	'IGNORE'>). At least, this is highly recommend in a networked program: If
		69	you use AnyEvent::Handle in a filter program (like sort), exiting on
		70	SIGPIPE is probably the right thing to do.
		71
		72	=head1 METHODS
		73
		74	=over 4
		75
		76	=item B<new (%args)>
		77
		78	The constructor supports these arguments (all as key => value pairs).
		79
		80	=over 4
		81
		82	=item fh => $filehandle [MANDATORY]
		83
		84	The filehandle this L<AnyEvent::Handle> object will operate on.
		85
		86	NOTE: The filehandle will be set to non-blocking mode (using
		87	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		88	that mode.
		89
		90	=item on_eof => $cb->($handle)
		91
		92	Set the callback to be called when an end-of-file condition is detected,
		93	i.e. in the case of a socket, when the other side has closed the
		94	connection cleanly.
		95
		96	For sockets, this just means that the other side has stopped sending data,
		97	you can still try to write data, and, in fact, one can return from the eof
		98	callback and continue writing data, as only the read part has been shut
		99	down.
		100
		101	While not mandatory, it is I<highly> recommended to set an eof callback,
		102	otherwise you might end up with a closed socket while you are still
		103	waiting for data.
		104
		105	If an EOF condition has been detected but no C<on_eof> callback has been
		106	set, then a fatal error will be raised with C<$!> set to <0>.
		107
		108	=item on_error => $cb->($handle, $fatal)
		109
		110	This is the error callback, which is called when, well, some error
		111	occured, such as not being able to resolve the hostname, failure to
		112	connect or a read error.
		113
		114	Some errors are fatal (which is indicated by C<$fatal> being true). On
		115	fatal errors the handle object will be shut down and will not be usable
		116	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
		117	errors are an EOF condition with active (but unsatisifable) read watchers
		118	(C<EPIPE>) or I/O errors.
		119
		120	Non-fatal errors can be retried by simply returning, but it is recommended
		121	to simply ignore this parameter and instead abondon the handle object
		122	when this callback is invoked. Examples of non-fatal errors are timeouts
		123	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		124
		125	On callback entrance, the value of C<$!> contains the operating system
		126	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
		127
		128	While not mandatory, it is I<highly> recommended to set this callback, as
		129	you will not be notified of errors otherwise. The default simply calls
		130	C<croak>.
		131
		132	=item on_read => $cb->($handle)
		133
		134	This sets the default read callback, which is called when data arrives
		135	and no read request is in the queue (unlike read queue callbacks, this
		136	callback will only be called when at least one octet of data is in the
		137	read buffer).
		138
		139	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		140	method or access the C<$handle->{rbuf}> member directly.
		141
		142	When an EOF condition is detected then AnyEvent::Handle will first try to
		143	feed all the remaining data to the queued callbacks and C<on_read> before
		144	calling the C<on_eof> callback. If no progress can be made, then a fatal
		145	error will be raised (with C<$!> set to C<EPIPE>).
		146
		147	=item on_drain => $cb->($handle)
		148
		149	This sets the callback that is called when the write buffer becomes empty
		150	(or when the callback is set and the buffer is empty already).
		151
		152	To append to the write buffer, use the C<< ->push_write >> method.
		153
		154	This callback is useful when you don't want to put all of your write data
		155	into the queue at once, for example, when you want to write the contents
		156	of some file to the socket you might not want to read the whole file into
		157	memory and push it into the queue, but instead only read more data from
		158	the file when the write queue becomes empty.
		159
		160	=item timeout => $fractional_seconds
		161
		162	If non-zero, then this enables an "inactivity" timeout: whenever this many
		163	seconds pass without a successful read or write on the underlying file
		164	handle, the C<on_timeout> callback will be invoked (and if that one is
		165	missing, a non-fatal C<ETIMEDOUT> error will be raised).
		166
		167	Note that timeout processing is also active when you currently do not have
		168	any outstanding read or write requests: If you plan to keep the connection
		169	idle then you should disable the timout temporarily or ignore the timeout
		170	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		171	restart the timeout.
		172
		173	Zero (the default) disables this timeout.
		174
		175	=item on_timeout => $cb->($handle)
		176
		177	Called whenever the inactivity timeout passes. If you return from this
		178	callback, then the timeout will be reset as if some activity had happened,
		179	so this condition is not fatal in any way.
		180
		181	=item rbuf_max => <bytes>
		182
		183	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		184	when the read buffer ever (strictly) exceeds this size. This is useful to
		185	avoid some forms of denial-of-service attacks.
		186
		187	For example, a server accepting connections from untrusted sources should
		188	be configured to accept only so-and-so much data that it cannot act on
		189	(for example, when expecting a line, an attacker could send an unlimited
		190	amount of data without a callback ever being called as long as the line
		191	isn't finished).
		192
		193	=item autocork => <boolean>
		194
		195	When disabled (the default), then C<push_write> will try to immediately
		196	write the data to the handle, if possible. This avoids having to register
		197	a write watcher and wait for the next event loop iteration, but can
		198	be inefficient if you write multiple small chunks (on the wire, this
		199	disadvantage is usually avoided by your kernel's nagle algorithm, see
		200	C<no_delay>, but this option can save costly syscalls).
		201
		202	When enabled, then writes will always be queued till the next event loop
		203	iteration. This is efficient when you do many small writes per iteration,
		204	but less efficient when you do a single write only per iteration (or when
		205	the write buffer often is full). It also increases write latency.
		206
		207	=item no_delay => <boolean>
		208
		209	When doing small writes on sockets, your operating system kernel might
		210	wait a bit for more data before actually sending it out. This is called
		211	the Nagle algorithm, and usually it is beneficial.
		212
		213	In some situations you want as low a delay as possible, which can be
		214	accomplishd by setting this option to a true value.
		215
		216	The default is your opertaing system's default behaviour (most likely
		217	enabled), this option explicitly enables or disables it, if possible.
		218
		219	=item read_size => <bytes>
		220
		221	The default read block size (the amount of bytes this module will
		222	try to read during each loop iteration, which affects memory
		223	requirements). Default: C<8192>.
		224
		225	=item low_water_mark => <bytes>
		226
		227	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		228	buffer: If the write reaches this size or gets even samller it is
		229	considered empty.
		230
		231	Sometimes it can be beneficial (for performance reasons) to add data to
		232	the write buffer before it is fully drained, but this is a rare case, as
		233	the operating system kernel usually buffers data as well, so the default
		234	is good in almost all cases.
		235
		236	=item linger => <seconds>
		237
		238	If non-zero (default: C<3600>), then the destructor of the
		239	AnyEvent::Handle object will check whether there is still outstanding
		240	write data and will install a watcher that will write this data to the
		241	socket. No errors will be reported (this mostly matches how the operating
		242	system treats outstanding data at socket close time).
		243
		244	This will not work for partial TLS data that could not be encoded
		245	yet. This data will be lost.
		246
		247	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		248
		249	When this parameter is given, it enables TLS (SSL) mode, that means
		250	AnyEvent will start a TLS handshake as soon as the conenction has been
		251	established and will transparently encrypt/decrypt data afterwards.
		252
		253	TLS mode requires Net::SSLeay to be installed (it will be loaded
		254	automatically when you try to create a TLS handle): this module doesn't
		255	have a dependency on that module, so if your module requires it, you have
		256	to add the dependency yourself.
		257
		258	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		259	C<accept>, and for the TLS client side of a connection, use C<connect>
		260	mode.
		261
		262	You can also provide your own TLS connection object, but you have
		263	to make sure that you call either C<Net::SSLeay::set_connect_state>
		264	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		265	AnyEvent::Handle.
		266
		267	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		268
		269	=item tls_ctx => $ssl_ctx
		270
		271	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
		272	(unless a connection object was specified directly). If this parameter is
		273	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		274
		275	=item json => JSON or JSON::XS object
		276
		277	This is the json coder object used by the C<json> read and write types.
		278
		279	If you don't supply it, then AnyEvent::Handle will create and use a
		280	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		281	texts.
		282
		283	Note that you are responsible to depend on the JSON module if you want to
		284	use this functionality, as AnyEvent does not have a dependency itself.
		285
		286	=item filter_r => $cb
		287
		288	=item filter_w => $cb
		289
		290	These exist, but are undocumented at this time. (They are used internally
		291	by the TLS code).
		292
		293	=back
		294
		295	=cut
		296
		297	sub new {
		298	my $class = shift;
		299
		300	my $self = bless { @_ }, $class;
		301
		302	$self->{fh} or Carp::croak "mandatory argument fh is missing";
		303
		304	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		305
		306	if ($self->{tls}) {
		307	require Net::SSLeay;
		308	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		309	}
		310
		311	$self->{_activity} = AnyEvent->now;
		312	$self->_timeout;
		313
		314	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
		315	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		316
		317	$self->start_read
		318	if $self->{on_read};
		319
		320	$self
		321	}
		322
		323	sub _shutdown {
		324	my ($self) = @_;
		325
		326	delete $self->{_tw};
		327	delete $self->{_rw};
		328	delete $self->{_ww};
		329	delete $self->{fh};
		330
		331	$self->stoptls;
		332
		333	delete $self->{on_read};
		334	delete $self->{_queue};
		335	}
		336
		337	sub _error {
		338	my ($self, $errno, $fatal) = @_;
		339
		340	$self->_shutdown
		341	if $fatal;
		342
		343	$! = $errno;
		344
		345	if ($self->{on_error}) {
		346	$self->{on_error}($self, $fatal);
		347	} else {
		348	Carp::croak "AnyEvent::Handle uncaught error: $!";
		349	}
		350	}
		351
		352	=item $fh = $handle->fh
		353
		354	This method returns the file handle used to create the L<AnyEvent::Handle> object.
		355
		356	=cut
		357
		358	sub fh { $_[0]{fh} }
		359
		360	=item $handle->on_error ($cb)
		361
		362	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		363
		364	=cut
		365
		366	sub on_error {
		367	$_[0]{on_error} = $_[1];
		368	}
		369
		370	=item $handle->on_eof ($cb)
		371
		372	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		373
		374	=cut
		375
		376	sub on_eof {
		377	$_[0]{on_eof} = $_[1];
		378	}
		379
		380	=item $handle->on_timeout ($cb)
		381
		382	Replace the current C<on_timeout> callback, or disables the callback (but
		383	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		384	argument and method.
		385
		386	=cut
		387
		388	sub on_timeout {
		389	$_[0]{on_timeout} = $_[1];
		390	}
		391
		392	=item $handle->autocork ($boolean)
		393
		394	Enables or disables the current autocork behaviour (see C<autocork>
		395	constructor argument).
		396
		397	=cut
		398
		399	=item $handle->no_delay ($boolean)
		400
		401	Enables or disables the C<no_delay> setting (see constructor argument of
		402	the same name for details).
		403
		404	=cut
		405
		406	sub no_delay {
		407	$_[0]{no_delay} = $_[1];
		408
		409	eval {
		410	local $SIG{__DIE__};
		411	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		412	};
		413	}
		414
		415	#############################################################################
		416
		417	=item $handle->timeout ($seconds)
		418
		419	Configures (or disables) the inactivity timeout.
		420
		421	=cut
		422
		423	sub timeout {
		424	my ($self, $timeout) = @_;
		425
		426	$self->{timeout} = $timeout;
		427	$self->_timeout;
		428	}
		429
		430	# reset the timeout watcher, as neccessary
		431	# also check for time-outs
		432	sub _timeout {
		433	my ($self) = @_;
		434
		435	if ($self->{timeout}) {
		436	my $NOW = AnyEvent->now;
		437
		438	# when would the timeout trigger?
		439	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		440
		441	# now or in the past already?
		442	if ($after <= 0) {
		443	$self->{_activity} = $NOW;
		444
		445	if ($self->{on_timeout}) {
		446	$self->{on_timeout}($self);
		447	} else {
		448	$self->_error (&Errno::ETIMEDOUT);
		449	}
		450
		451	# callback could have changed timeout value, optimise
		452	return unless $self->{timeout};
		453
		454	# calculate new after
		455	$after = $self->{timeout};
36	}	456	}
37	$cv->broadcast;	457
		458	Scalar::Util::weaken $self;
		459	return unless $self; # ->error could have destroyed $self
		460
		461	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		462	delete $self->{_tw};
		463	$self->_timeout;
		464	});
		465	} else {
		466	delete $self->{_tw};
		467	}
		468	}
		469
		470	#############################################################################
		471
		472	=back
		473
		474	=head2 WRITE QUEUE
		475
		476	AnyEvent::Handle manages two queues per handle, one for writing and one
		477	for reading.
		478
		479	The write queue is very simple: you can add data to its end, and
		480	AnyEvent::Handle will automatically try to get rid of it for you.
		481
		482	When data could be written and the write buffer is shorter then the low
		483	water mark, the C<on_drain> callback will be invoked.
		484
		485	=over 4
		486
		487	=item $handle->on_drain ($cb)
		488
		489	Sets the C<on_drain> callback or clears it (see the description of
		490	C<on_drain> in the constructor).
		491
		492	=cut
		493
		494	sub on_drain {
		495	my ($self, $cb) = @_;
		496
		497	$self->{on_drain} = $cb;
		498
		499	$cb->($self)
		500	if $cb && $self->{low_water_mark} >= length $self->{wbuf};
		501	}
		502
		503	=item $handle->push_write ($data)
		504
		505	Queues the given scalar to be written. You can push as much data as you
		506	want (only limited by the available memory), as C<AnyEvent::Handle>
		507	buffers it independently of the kernel.
		508
		509	=cut
		510
		511	sub _drain_wbuf {
		512	my ($self) = @_;
		513
		514	if (!$self->{_ww} && length $self->{wbuf}) {
		515
		516	Scalar::Util::weaken $self;
		517
		518	my $cb = sub {
		519	my $len = syswrite $self->{fh}, $self->{wbuf};
		520
		521	if ($len >= 0) {
		522	substr $self->{wbuf}, 0, $len, "";
		523
		524	$self->{_activity} = AnyEvent->now;
		525
		526	$self->{on_drain}($self)
		527	if $self->{low_water_mark} >= length $self->{wbuf}
		528	&& $self->{on_drain};
		529
		530	delete $self->{_ww} unless length $self->{wbuf};
		531	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		532	$self->_error ($!, 1);
		533	}
		534	};
		535
		536	# try to write data immediately
		537	$cb->() unless $self->{autocork};
		538
		539	# if still data left in wbuf, we need to poll
		540	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
		541	if length $self->{wbuf};
		542	};
		543	}
		544
		545	our %WH;
		546
		547	sub register_write_type($$) {
		548	$WH{$_[0]} = $_[1];
		549	}
		550
		551	sub push_write {
		552	my $self = shift;
		553
		554	if (@_ > 1) {
		555	my $type = shift;
		556
		557	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		558	->($self, @_);
		559	}
		560
		561	if ($self->{filter_w}) {
		562	$self->{filter_w}($self, \$_[0]);
		563	} else {
		564	$self->{wbuf} .= $_[0];
		565	$self->_drain_wbuf;
		566	}
		567	}
		568
		569	=item $handle->push_write (type => @args)
		570
		571	Instead of formatting your data yourself, you can also let this module do
		572	the job by specifying a type and type-specific arguments.
		573
		574	Predefined types are (if you have ideas for additional types, feel free to
		575	drop by and tell us):
		576
		577	=over 4
		578
		579	=item netstring => $string
		580
		581	Formats the given value as netstring
		582	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		583
		584	=cut
		585
		586	register_write_type netstring => sub {
		587	my ($self, $string) = @_;
		588
		589	sprintf "%d:%s,", (length $string), $string
		590	};
		591
		592	=item packstring => $format, $data
		593
		594	An octet string prefixed with an encoded length. The encoding C<$format>
		595	uses the same format as a Perl C<pack> format, but must specify a single
		596	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		597	optional C<!>, C<< < >> or C<< > >> modifier).
		598
		599	=cut
		600
		601	register_write_type packstring => sub {
		602	my ($self, $format, $string) = @_;
		603
		604	pack "$format/a*", $string
		605	};
		606
		607	=item json => $array_or_hashref
		608
		609	Encodes the given hash or array reference into a JSON object. Unless you
		610	provide your own JSON object, this means it will be encoded to JSON text
		611	in UTF-8.
		612
		613	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		614	one end of a handle and read them at the other end without using any
		615	additional framing.
		616
		617	The generated JSON text is guaranteed not to contain any newlines: While
		618	this module doesn't need delimiters after or between JSON texts to be
		619	able to read them, many other languages depend on that.
		620
		621	A simple RPC protocol that interoperates easily with others is to send
		622	JSON arrays (or objects, although arrays are usually the better choice as
		623	they mimic how function argument passing works) and a newline after each
		624	JSON text:
		625
		626	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		627	$handle->push_write ("\012");
		628
		629	An AnyEvent::Handle receiver would simply use the C<json> read type and
		630	rely on the fact that the newline will be skipped as leading whitespace:
		631
		632	$handle->push_read (json => sub { my $array = $_[1]; ... });
		633
		634	Other languages could read single lines terminated by a newline and pass
		635	this line into their JSON decoder of choice.
		636
		637	=cut
		638
		639	register_write_type json => sub {
		640	my ($self, $ref) = @_;
		641
		642	require JSON;
		643
		644	$self->{json} ? $self->{json}->encode ($ref)
		645	: JSON::encode_json ($ref)
		646	};
		647
		648	=item storable => $reference
		649
		650	Freezes the given reference using L<Storable> and writes it to the
		651	handle. Uses the C<nfreeze> format.
		652
		653	=cut
		654
		655	register_write_type storable => sub {
		656	my ($self, $ref) = @_;
		657
		658	require Storable;
		659
		660	pack "w/a*", Storable::nfreeze ($ref)
		661	};
		662
		663	=back
		664
		665	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		666
		667	This function (not method) lets you add your own types to C<push_write>.
		668	Whenever the given C<type> is used, C<push_write> will invoke the code
		669	reference with the handle object and the remaining arguments.
		670
		671	The code reference is supposed to return a single octet string that will
		672	be appended to the write buffer.
		673
		674	Note that this is a function, and all types registered this way will be
		675	global, so try to use unique names.
		676
		677	=cut
		678
		679	#############################################################################
		680
		681	=back
		682
		683	=head2 READ QUEUE
		684
		685	AnyEvent::Handle manages two queues per handle, one for writing and one
		686	for reading.
		687
		688	The read queue is more complex than the write queue. It can be used in two
		689	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		690	a queue.
		691
		692	In the simple case, you just install an C<on_read> callback and whenever
		693	new data arrives, it will be called. You can then remove some data (if
		694	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		695	leave the data there if you want to accumulate more (e.g. when only a
		696	partial message has been received so far).
		697
		698	In the more complex case, you want to queue multiple callbacks. In this
		699	case, AnyEvent::Handle will call the first queued callback each time new
		700	data arrives (also the first time it is queued) and removes it when it has
		701	done its job (see C<push_read>, below).
		702
		703	This way you can, for example, push three line-reads, followed by reading
		704	a chunk of data, and AnyEvent::Handle will execute them in order.
		705
		706	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		707	the specified number of bytes which give an XML datagram.
		708
		709	# in the default state, expect some header bytes
		710	$handle->on_read (sub {
		711	# some data is here, now queue the length-header-read (4 octets)
		712	shift->unshift_read (chunk => 4, sub {
		713	# header arrived, decode
		714	my $len = unpack "N", $_[1];
		715
		716	# now read the payload
		717	shift->unshift_read (chunk => $len, sub {
		718	my $xml = $_[1];
		719	# handle xml
		720	});
		721	});
38	});	722	});
39		723
40	$cv->wait;	724	Example 2: Implement a client for a protocol that replies either with "OK"
		725	and another line or "ERROR" for the first request that is sent, and 64
		726	bytes for the second request. Due to the availability of a queue, we can
		727	just pipeline sending both requests and manipulate the queue as necessary
		728	in the callbacks.
41		729
42	=head1 DESCRIPTION	730	When the first callback is called and sees an "OK" response, it will
		731	C<unshift> another line-read. This line-read will be queued I<before> the
		732	64-byte chunk callback.
43		733
44	This module is a helper module to make it easier to do non-blocking I/O	734	# request one, returns either "OK + extra line" or "ERROR"
45	on filehandles (and sockets, see L<AnyEvent::Socket>).	735	$handle->push_write ("request 1\015\012");
46		736
47	The event loop is provided by L<AnyEvent>.	737	# we expect "ERROR" or "OK" as response, so push a line read
		738	$handle->push_read (line => sub {
		739	# if we got an "OK", we have to _prepend_ another line,
		740	# so it will be read before the second request reads its 64 bytes
		741	# which are already in the queue when this callback is called
		742	# we don't do this in case we got an error
		743	if ($_[1] eq "OK") {
		744	$_[0]->unshift_read (line => sub {
		745	my $response = $_[1];
		746	...
		747	});
		748	}
		749	});
48		750
49	=head1 METHODS	751	# request two, simply returns 64 octets
		752	$handle->push_write ("request 2\015\012");
		753
		754	# simply read 64 bytes, always
		755	$handle->push_read (chunk => 64, sub {
		756	my $response = $_[1];
		757	...
		758	});
50		759
51	=over 4	760	=over 4
52		761
53	=item B<new (%args)>
54
55	The constructor has these arguments:
56
57	=over 4
58
59	=item fh => $filehandle
60
61	The filehandle this L<AnyEvent::Handle> object will operate on.
62
63	NOTE: The filehandle will be set to non-blocking.
64
65	=item read_block_size => $size
66
67	The default read block size use for reads via the C<on_read>
68	method.
69
70	=back
71
72	=cut	762	=cut
73		763
74	sub new {	764	sub _drain_rbuf {
75	my $this = shift;
76	my $class = ref($this) || $this;
77	my $self = {	765	my ($self) = @_;
78	read_block_size => 4096,	766
79	rbuf => '',	767	local $self->{_in_drain} = 1;
80	@_	768
		769	if (
		770	defined $self->{rbuf_max}
		771	&& $self->{rbuf_max} < length $self->{rbuf}
		772	) {
		773	$self->_error (&Errno::ENOSPC, 1), return;
81	};	774	}
82	bless $self, $class;
83		775
84	$self->{fh}->blocking (0) if $self->{fh};	776	while () {
		777	my $len = length $self->{rbuf};
85		778
86	if ($self->{on_read}) {	779	if (my $cb = shift @{ $self->{_queue} }) {
87	$self->on_read ($self->{on_read});	780	unless ($cb->($self)) {
		781	if ($self->{_eof}) {
		782	# no progress can be made (not enough data and no data forthcoming)
		783	$self->_error (&Errno::EPIPE, 1), return;
		784	}
88		785
		786	unshift @{ $self->{_queue} }, $cb;
		787	last;
		788	}
89	} elsif ($self->{on_readline}) {	789	} elsif ($self->{on_read}) {
90	$self->readlines ($self->{on_readline});	790	last unless $len;
91	}
92		791
93	return $self	792	$self->{on_read}($self);
94	}
95		793
96	=item B<fh>	794	if (
		795	$len == length $self->{rbuf} # if no data has been consumed
		796	&& !@{ $self->{_queue} } # and the queue is still empty
		797	&& $self->{on_read} # but we still have on_read
		798	) {
		799	# no further data will arrive
		800	# so no progress can be made
		801	$self->_error (&Errno::EPIPE, 1), return
		802	if $self->{_eof};
97		803
98	This method returns the filehandle of the L<AnyEvent::Handle> object.	804	last; # more data might arrive
		805	}
		806	} else {
		807	# read side becomes idle
		808	delete $self->{_rw};
		809	last;
		810	}
		811	}
99		812
100	=cut	813	if ($self->{_eof}) {
		814	if ($self->{on_eof}) {
		815	$self->{on_eof}($self)
		816	} else {
		817	$self->_error (0, 1);
		818	}
		819	}
101		820
102	sub fh { $_[0]->{fh} }	821	# may need to restart read watcher
		822	unless ($self->{_rw}) {
		823	$self->start_read
		824	if $self->{on_read} || @{ $self->{_queue} };
		825	}
		826	}
103		827
104	=item B<on_read ($callback)>	828	=item $handle->on_read ($cb)
105		829
106	This method installs a C<$callback> that will be called	830	This replaces the currently set C<on_read> callback, or clears it (when
107	when new data arrived. You can access the read buffer via the C<rbuf>	831	the new callback is C<undef>). See the description of C<on_read> in the
108	method (see below).	832	constructor.
109
110	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
111		833
112	=cut	834	=cut
113		835
114	sub on_read {	836	sub on_read {
115	my ($self, $cb) = @_;	837	my ($self, $cb) = @_;
		838
116	$self->{on_read} = $cb;	839	$self->{on_read} = $cb;
		840	$self->_drain_rbuf if $cb && !$self->{_in_drain};
		841	}
117		842
118	unless (defined $self->{on_read}) {	843	=item $handle->rbuf
119	delete $self->{on_read_w};	844
		845	Returns the read buffer (as a modifiable lvalue).
		846
		847	You can access the read buffer directly as the C<< ->{rbuf} >> member, if
		848	you want.
		849
		850	NOTE: The read buffer should only be used or modified if the C<on_read>,
		851	C<push_read> or C<unshift_read> methods are used. The other read methods
		852	automatically manage the read buffer.
		853
		854	=cut
		855
		856	sub rbuf : lvalue {
		857	$_[0]{rbuf}
		858	}
		859
		860	=item $handle->push_read ($cb)
		861
		862	=item $handle->unshift_read ($cb)
		863
		864	Append the given callback to the end of the queue (C<push_read>) or
		865	prepend it (C<unshift_read>).
		866
		867	The callback is called each time some additional read data arrives.
		868
		869	It must check whether enough data is in the read buffer already.
		870
		871	If not enough data is available, it must return the empty list or a false
		872	value, in which case it will be called repeatedly until enough data is
		873	available (or an error condition is detected).
		874
		875	If enough data was available, then the callback must remove all data it is
		876	interested in (which can be none at all) and return a true value. After returning
		877	true, it will be removed from the queue.
		878
		879	=cut
		880
		881	our %RH;
		882
		883	sub register_read_type($$) {
		884	$RH{$_[0]} = $_[1];
		885	}
		886
		887	sub push_read {
		888	my $self = shift;
		889	my $cb = pop;
		890
		891	if (@_) {
		892	my $type = shift;
		893
		894	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		895	->($self, $cb, @_);
		896	}
		897
		898	push @{ $self->{_queue} }, $cb;
		899	$self->_drain_rbuf unless $self->{_in_drain};
		900	}
		901
		902	sub unshift_read {
		903	my $self = shift;
		904	my $cb = pop;
		905
		906	if (@_) {
		907	my $type = shift;
		908
		909	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		910	->($self, $cb, @_);
		911	}
		912
		913
		914	unshift @{ $self->{_queue} }, $cb;
		915	$self->_drain_rbuf unless $self->{_in_drain};
		916	}
		917
		918	=item $handle->push_read (type => @args, $cb)
		919
		920	=item $handle->unshift_read (type => @args, $cb)
		921
		922	Instead of providing a callback that parses the data itself you can chose
		923	between a number of predefined parsing formats, for chunks of data, lines
		924	etc.
		925
		926	Predefined types are (if you have ideas for additional types, feel free to
		927	drop by and tell us):
		928
		929	=over 4
		930
		931	=item chunk => $octets, $cb->($handle, $data)
		932
		933	Invoke the callback only once C<$octets> bytes have been read. Pass the
		934	data read to the callback. The callback will never be called with less
		935	data.
		936
		937	Example: read 2 bytes.
		938
		939	$handle->push_read (chunk => 2, sub {
		940	warn "yay ", unpack "H*", $_[1];
		941	});
		942
		943	=cut
		944
		945	register_read_type chunk => sub {
		946	my ($self, $cb, $len) = @_;
		947
		948	sub {
		949	$len <= length $_[0]{rbuf} or return;
		950	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
		951	1
		952	}
		953	};
		954
		955	=item line => [$eol, ]$cb->($handle, $line, $eol)
		956
		957	The callback will be called only once a full line (including the end of
		958	line marker, C<$eol>) has been read. This line (excluding the end of line
		959	marker) will be passed to the callback as second argument (C<$line>), and
		960	the end of line marker as the third argument (C<$eol>).
		961
		962	The end of line marker, C<$eol>, can be either a string, in which case it
		963	will be interpreted as a fixed record end marker, or it can be a regex
		964	object (e.g. created by C<qr>), in which case it is interpreted as a
		965	regular expression.
		966
		967	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		968	undef), then C<qr|\015?\012|> is used (which is good for most internet
		969	protocols).
		970
		971	Partial lines at the end of the stream will never be returned, as they are
		972	not marked by the end of line marker.
		973
		974	=cut
		975
		976	register_read_type line => sub {
		977	my ($self, $cb, $eol) = @_;
		978
		979	if (@_ < 3) {
		980	# this is more than twice as fast as the generic code below
		981	sub {
		982	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		983
		984	$cb->($_[0], $1, $2);
		985	1
		986	}
		987	} else {
		988	$eol = quotemeta $eol unless ref $eol;
		989	$eol = qr|^(.*?)($eol)|s;
		990
		991	sub {
		992	$_[0]{rbuf} =~ s/$eol// or return;
		993
		994	$cb->($_[0], $1, $2);
		995	1
		996	}
		997	}
		998	};
		999
		1000	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1001
		1002	Makes a regex match against the regex object C<$accept> and returns
		1003	everything up to and including the match.
		1004
		1005	Example: read a single line terminated by '\n'.
		1006
		1007	$handle->push_read (regex => qr<\n>, sub { ... });
		1008
		1009	If C<$reject> is given and not undef, then it determines when the data is
		1010	to be rejected: it is matched against the data when the C<$accept> regex
		1011	does not match and generates an C<EBADMSG> error when it matches. This is
		1012	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1013	receive buffer overflow).
		1014
		1015	Example: expect a single decimal number followed by whitespace, reject
		1016	anything else (not the use of an anchor).
		1017
		1018	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1019
		1020	If C<$skip> is given and not C<undef>, then it will be matched against
		1021	the receive buffer when neither C<$accept> nor C<$reject> match,
		1022	and everything preceding and including the match will be accepted
		1023	unconditionally. This is useful to skip large amounts of data that you
		1024	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1025	have to start matching from the beginning. This is purely an optimisation
		1026	and is usually worth only when you expect more than a few kilobytes.
		1027
		1028	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1029	expect the header to be very large (it isn't in practise, but...), we use
		1030	a skip regex to skip initial portions. The skip regex is tricky in that
		1031	it only accepts something not ending in either \015 or \012, as these are
		1032	required for the accept regex.
		1033
		1034	$handle->push_read (regex =>
		1035	qr<\015\012\015\012>,
		1036	undef, # no reject
		1037	qr<^.*[^\015\012]>,
		1038	sub { ... });
		1039
		1040	=cut
		1041
		1042	register_read_type regex => sub {
		1043	my ($self, $cb, $accept, $reject, $skip) = @_;
		1044
		1045	my $data;
		1046	my $rbuf = \$self->{rbuf};
		1047
		1048	sub {
		1049	# accept
		1050	if ($$rbuf =~ $accept) {
		1051	$data .= substr $$rbuf, 0, $+[0], "";
		1052	$cb->($self, $data);
120	return;	1053	return 1;
		1054	}
		1055
		1056	# reject
		1057	if ($reject && $$rbuf =~ $reject) {
		1058	$self->_error (&Errno::EBADMSG);
		1059	}
		1060
		1061	# skip
		1062	if ($skip && $$rbuf =~ $skip) {
		1063	$data .= substr $$rbuf, 0, $+[0], "";
		1064	}
		1065
		1066	()
121	}	1067	}
122		1068	};
123	$self->{on_read_w} =	1069
124	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	1070	=item netstring => $cb->($handle, $string)
125	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	1071
126	my $rbuf_len = length $self->{rbuf};	1072	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
127	my $l;	1073
128	if (defined $self->{read_size}) {	1074	Throws an error with C<$!> set to EBADMSG on format violations.
129	$l = sysread $self->{fh}, $self->{rbuf},	1075
130	($self->{read_size} - $rbuf_len), $rbuf_len;	1076	=cut
131	} else {	1077
132	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	1078	register_read_type netstring => sub {
		1079	my ($self, $cb) = @_;
		1080
		1081	sub {
		1082	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1083	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1084	$self->_error (&Errno::EBADMSG);
133	}	1085	}
134	#d# warn "READL $l [$self->{rbuf}]\n";	1086	return;
		1087	}
135		1088
136	if (not defined $l) {	1089	my $len = $1;
137	return if $! == EAGAIN || $! == EINTR;
138	$self->{on_error}->($self, $!) if $self->{on_error};
139	delete $self->{on_read_w};
140		1090
141	} elsif ($l == 0) {	1091	$self->unshift_read (chunk => $len, sub {
142	$self->{on_eof}->($self) if $self->{on_eof};	1092	my $string = $_[1];
143	delete $self->{on_read_w};	1093	$_[0]->unshift_read (chunk => 1, sub {
144		1094	if ($_[1] eq ",") {
		1095	$cb->($_[0], $string);
145	} else {	1096	} else {
146	$self->{on_read}->($self);	1097	$self->_error (&Errno::EBADMSG);
		1098	}
		1099	});
		1100	});
		1101
		1102	1
		1103	}
		1104	};
		1105
		1106	=item packstring => $format, $cb->($handle, $string)
		1107
		1108	An octet string prefixed with an encoded length. The encoding C<$format>
		1109	uses the same format as a Perl C<pack> format, but must specify a single
		1110	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1111	optional C<!>, C<< < >> or C<< > >> modifier).
		1112
		1113	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1114
		1115	Example: read a block of data prefixed by its length in BER-encoded
		1116	format (very efficient).
		1117
		1118	$handle->push_read (packstring => "w", sub {
		1119	my ($handle, $data) = @_;
		1120	});
		1121
		1122	=cut
		1123
		1124	register_read_type packstring => sub {
		1125	my ($self, $cb, $format) = @_;
		1126
		1127	sub {
		1128	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1129	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1130	or return;
		1131
		1132	$format = length pack $format, $len;
		1133
		1134	# bypass unshift if we already have the remaining chunk
		1135	if ($format + $len <= length $_[0]{rbuf}) {
		1136	my $data = substr $_[0]{rbuf}, $format, $len;
		1137	substr $_[0]{rbuf}, 0, $format + $len, "";
		1138	$cb->($_[0], $data);
		1139	} else {
		1140	# remove prefix
		1141	substr $_[0]{rbuf}, 0, $format, "";
		1142
		1143	# read remaining chunk
		1144	$_[0]->unshift_read (chunk => $len, $cb);
		1145	}
		1146
		1147	1
		1148	}
		1149	};
		1150
		1151	=item json => $cb->($handle, $hash_or_arrayref)
		1152
		1153	Reads a JSON object or array, decodes it and passes it to the callback.
		1154
		1155	If a C<json> object was passed to the constructor, then that will be used
		1156	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1157
		1158	This read type uses the incremental parser available with JSON version
		1159	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1160	dependency on your own: this module will load the JSON module, but
		1161	AnyEvent does not depend on it itself.
		1162
		1163	Since JSON texts are fully self-delimiting, the C<json> read and write
		1164	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1165	the C<json> write type description, above, for an actual example.
		1166
		1167	=cut
		1168
		1169	register_read_type json => sub {
		1170	my ($self, $cb) = @_;
		1171
		1172	require JSON;
		1173
		1174	my $data;
		1175	my $rbuf = \$self->{rbuf};
		1176
		1177	my $json = $self->{json} ||= JSON->new->utf8;
		1178
		1179	sub {
		1180	my $ref = $json->incr_parse ($self->{rbuf});
		1181
		1182	if ($ref) {
		1183	$self->{rbuf} = $json->incr_text;
		1184	$json->incr_text = "";
		1185	$cb->($self, $ref);
		1186
		1187	1
		1188	} else {
		1189	$self->{rbuf} = "";
		1190	()
		1191	}
		1192	}
		1193	};
		1194
		1195	=item storable => $cb->($handle, $ref)
		1196
		1197	Deserialises a L<Storable> frozen representation as written by the
		1198	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1199	data).
		1200
		1201	Raises C<EBADMSG> error if the data could not be decoded.
		1202
		1203	=cut
		1204
		1205	register_read_type storable => sub {
		1206	my ($self, $cb) = @_;
		1207
		1208	require Storable;
		1209
		1210	sub {
		1211	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1212	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1213	or return;
		1214
		1215	my $format = length pack "w", $len;
		1216
		1217	# bypass unshift if we already have the remaining chunk
		1218	if ($format + $len <= length $_[0]{rbuf}) {
		1219	my $data = substr $_[0]{rbuf}, $format, $len;
		1220	substr $_[0]{rbuf}, 0, $format + $len, "";
		1221	$cb->($_[0], Storable::thaw ($data));
		1222	} else {
		1223	# remove prefix
		1224	substr $_[0]{rbuf}, 0, $format, "";
		1225
		1226	# read remaining chunk
		1227	$_[0]->unshift_read (chunk => $len, sub {
		1228	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1229	$cb->($_[0], $ref);
		1230	} else {
		1231	$self->_error (&Errno::EBADMSG);
		1232	}
		1233	});
		1234	}
		1235
		1236	1
		1237	}
		1238	};
		1239
		1240	=back
		1241
		1242	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1243
		1244	This function (not method) lets you add your own types to C<push_read>.
		1245
		1246	Whenever the given C<type> is used, C<push_read> will invoke the code
		1247	reference with the handle object, the callback and the remaining
		1248	arguments.
		1249
		1250	The code reference is supposed to return a callback (usually a closure)
		1251	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1252
		1253	It should invoke the passed callback when it is done reading (remember to
		1254	pass C<$handle> as first argument as all other callbacks do that).
		1255
		1256	Note that this is a function, and all types registered this way will be
		1257	global, so try to use unique names.
		1258
		1259	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1260	search for C<register_read_type>)).
		1261
		1262	=item $handle->stop_read
		1263
		1264	=item $handle->start_read
		1265
		1266	In rare cases you actually do not want to read anything from the
		1267	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1268	any queued callbacks will be executed then. To start reading again, call
		1269	C<start_read>.
		1270
		1271	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1272	you change the C<on_read> callback or push/unshift a read callback, and it
		1273	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1274	there are any read requests in the queue.
		1275
		1276	=cut
		1277
		1278	sub stop_read {
		1279	my ($self) = @_;
		1280
		1281	delete $self->{_rw};
		1282	}
		1283
		1284	sub start_read {
		1285	my ($self) = @_;
		1286
		1287	unless ($self->{_rw} || $self->{_eof}) {
		1288	Scalar::Util::weaken $self;
		1289
		1290	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1291	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
		1292	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1293
		1294	if ($len > 0) {
		1295	$self->{_activity} = AnyEvent->now;
		1296
		1297	$self->{filter_r}
		1298	? $self->{filter_r}($self, $rbuf)
		1299	: $self->{_in_drain} || $self->_drain_rbuf;
		1300
		1301	} elsif (defined $len) {
		1302	delete $self->{_rw};
		1303	$self->{_eof} = 1;
		1304	$self->_drain_rbuf unless $self->{_in_drain};
		1305
		1306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1307	return $self->_error ($!, 1);
147	}	1308	}
148	});	1309	});
		1310	}
149	}	1311	}
150		1312
151	=item B<on_error ($callback)>	1313	sub _dotls {
152
153	Whenever a read or write operation resulted in an error the C<$callback>
154	will be called.
155
156	The first argument of C<$callback> will be the L<AnyEvent::Handle> object itself
157	and the second argument will be the value of C<$!>.
158
159	=cut
160
161	sub on_error {
162	$_[0]->{on_error} = $_[1];
163	}
164
165	=item B<on_eof ($callback)>
166
167	Installs the C<$callback> that will be called when the end of file is
168	encountered in a read operation this C<$callback> will be called. The first
169	argument will be the L<AnyEvent::Handle> object itself.
170
171	=cut
172
173	sub on_eof {
174	$_[0]->{on_eof} = $_[1];
175	}
176
177	=item B<rbuf>
178
179	Returns a reference to the read buffer.
180
181	NOTE: The read buffer should only be used or modified if the C<on_read>
182	method is used directly. The C<read> and C<readlines> methods will provide
183	the read data to their callbacks.
184
185	=cut
186
187	sub rbuf : lvalue { $_[0]->{rbuf} }
188
189	=item B<read ($len, $callback)>
190
191	Will read exactly C<$len> bytes from the filehandle and call the C<$callback>
192	if done so. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
193	object itself and the second argument the read data.
194
195	NOTE: This method will override any callbacks installed via the C<on_read> method.
196
197	=cut
198
199	sub read {
200	my ($self, $len, $cb) = @_;	1314	my ($self) = @_;
201		1315
202	$self->{read_cb} = $cb;	1316	my $buf;
203	my $old_blk_size = $self->{read_block_size};
204	$self->{read_block_size} = $len;
205		1317
206	$self->on_read (sub {	1318	if (length $self->{_tls_wbuf}) {
207	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";	1319	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
208		1320	substr $self->{_tls_wbuf}, 0, $len, "";
209	if ($len == length $_[0]->{rbuf}) {
210	$_[0]->{read_block_size} = $old_blk_size;
211	$_[0]->on_read (undef);
212	$_[0]->{read_cb}->($_[0], (substr $self->{rbuf}, 0, $len, ''));
213	}	1321	}
		1322	}
		1323
		1324	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1325	unless (length $buf) {
		1326	# let's treat SSL-eof as we treat normal EOF
		1327	delete $self->{_rw};
		1328	$self->{_eof} = 1;
		1329	}
		1330
		1331	$self->{rbuf} .= $buf;
		1332	$self->_drain_rbuf unless $self->{_in_drain};
		1333
		1334	$self->{tls} or return; # tls could have gone away
		1335	}
		1336
		1337	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1338
		1339	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1340	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1341	return $self->_error ($!, 1);
		1342	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1343	return $self->_error (&Errno::EIO, 1);
		1344	}
		1345
		1346	# all others are fine for our purposes
		1347	}
		1348
		1349	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1350	$self->{wbuf} .= $buf;
		1351	$self->_drain_wbuf;
		1352	}
		1353	}
		1354
		1355	=item $handle->starttls ($tls[, $tls_ctx])
		1356
		1357	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1358	object is created, you can also do that at a later time by calling
		1359	C<starttls>.
		1360
		1361	The first argument is the same as the C<tls> constructor argument (either
		1362	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1363
		1364	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1365	used when AnyEvent::Handle has to create its own TLS connection object.
		1366
		1367	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1368	call and can be used or changed to your liking. Note that the handshake
		1369	might have already started when this function returns.
		1370
		1371	=cut
		1372
		1373	sub starttls {
		1374	my ($self, $ssl, $ctx) = @_;
		1375
		1376	$self->stoptls;
		1377
		1378	if ($ssl eq "accept") {
		1379	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1380	Net::SSLeay::set_accept_state ($ssl);
		1381	} elsif ($ssl eq "connect") {
		1382	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1383	Net::SSLeay::set_connect_state ($ssl);
		1384	}
		1385
		1386	$self->{tls} = $ssl;
		1387
		1388	# basically, this is deep magic (because SSL_read should have the same issues)
		1389	# but the openssl maintainers basically said: "trust us, it just works".
		1390	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1391	# and mismaintained ssleay-module doesn't even offer them).
		1392	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1393	#
		1394	# in short: this is a mess.
		1395	#
		1396	# note that we do not try to kepe the length constant between writes as we are required to do.
		1397	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1398	# and we drive openssl fully in blocking mode here.
		1399	Net::SSLeay::CTX_set_mode ($self->{tls},
		1400	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1401	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1402
		1403	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1404	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1405
		1406	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1407
		1408	$self->{filter_w} = sub {
		1409	$_[0]{_tls_wbuf} .= ${$_[1]};
		1410	&_dotls;
214	});	1411	};
215	}	1412	$self->{filter_r} = sub {
216		1413	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
217	=item B<readlines ($callback)>	1414	&_dotls;
218
219	=item B<readlines ($sep, $callback)>
220
221	This method will read lines from the filehandle, seperated by C<$sep> or C<"\n">
222	if C<$sep> is not provided. C<$sep> will be used as part of a regex, so it can be
223	a regex itself and won't be quoted!
224
225	The C<$callback> will be called when at least one
226	line could be read. The first argument to the C<$callback> will be the L<AnyEvent::Handle>
227	object itself and the rest of the arguments will be the read lines.
228
229	NOTE: This method will override any callbacks installed via the C<on_read> method.
230
231	=cut
232
233	sub readlines {
234	my ($self, $NL, $cb) = @_;
235
236	if (ref $NL) {
237	$cb = $NL;
238	$NL = "\n";
239	}
240
241	$self->{on_readline} = $cb;
242
243	$self->on_read (sub {
244	my @lines;
245	push @lines, $1 while $_[0]->{rbuf} =~ s/(.*)$NL//;
246	$self->{on_readline}->($_[0], @lines);
247	});	1415	};
248	}
249		1416
250	=item B<write ($data)>	1417	&_dotls; # need to trigger the initial negotiation exchange
251
252	=item B<write ($callback)>
253
254	=item B<write ($data, $callback)>
255
256	This method will write C<$data> to the filehandle and call the C<$callback>
257	afterwards. If only C<$callback> is provided it will be called when the
258	write buffer becomes empty the next time (or immediately if it already is empty).
259
260	=cut
261
262	sub write {
263	my ($self, $data, $cb) = @_;
264	if (ref $data) { $cb = $data; undef $data }
265	push @{$self->{write_bufs}}, [$data, $cb];
266	$self->_check_writer;
267	}	1418	}
268		1419
269	sub _check_writer {	1420	=item $handle->stoptls
		1421
		1422	Destroys the SSL connection, if any. Partial read or write data will be
		1423	lost.
		1424
		1425	=cut
		1426
		1427	sub stoptls {
270	my ($self) = @_;	1428	my ($self) = @_;
271		1429
272	if ($self->{write_w}) {	1430	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
273	unless ($self->{write_cb}) {
274	while (@{$self->{write_bufs}} && not defined $self->{write_bufs}->[0]->[1]) {
275	my $wba = shift @{$self->{write_bufs}};
276	$self->{wbuf} .= $wba->[0];
277	}
278	}
279	return;
280	}
281		1431
282	my $wba = shift @{$self->{write_bufs}}	1432	delete $self->{_rbio};
283	or return;	1433	delete $self->{_wbio};
		1434	delete $self->{_tls_wbuf};
		1435	delete $self->{filter_r};
		1436	delete $self->{filter_w};
		1437	}
284		1438
285	unless (defined $wba->[0]) {	1439	sub DESTROY {
286	$wba->[1]->($self) if $wba->[1];	1440	my $self = shift;
287	$self->_check_writer;
288	return;
289	}
290		1441
291	$self->{wbuf} = $wba->[0];	1442	$self->stoptls;
292	$self->{write_cb} = $wba->[1];
293		1443
294	$self->{write_w} =	1444	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
295	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {	1445
		1446	if ($linger && length $self->{wbuf}) {
		1447	my $fh = delete $self->{fh};
		1448	my $wbuf = delete $self->{wbuf};
		1449
		1450	my @linger;
		1451
		1452	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
296	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};	1453	my $len = syswrite $fh, $wbuf, length $wbuf;
297		1454
298	if (not defined $l) {	1455	if ($len > 0) {
299	return if $! == EAGAIN || $! == EINTR;	1456	substr $wbuf, 0, $len, "";
300	delete $self->{write_w};
301
302	$self->{on_error}->($self, $!) if $self->{on_error};
303
304	} else {	1457	} else {
305	substr $self->{wbuf}, 0, $l, '';	1458	@linger = (); # end
306
307	if (length ($self->{wbuf}) == 0) {
308	$self->{write_cb}->($self) if $self->{write_cb};
309
310	delete $self->{write_w};
311	delete $self->{wbuf};
312	delete $self->{write_cb};
313
314	$self->_check_writer;
315	}
316	}	1459	}
317	});	1460	});
		1461	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1462	@linger = ();
		1463	});
		1464	}
		1465	}
		1466
		1467	=item AnyEvent::Handle::TLS_CTX
		1468
		1469	This function creates and returns the Net::SSLeay::CTX object used by
		1470	default for TLS mode.
		1471
		1472	The context is created like this:
		1473
		1474	Net::SSLeay::load_error_strings;
		1475	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1476	Net::SSLeay::randomize;
		1477
		1478	my $CTX = Net::SSLeay::CTX_new;
		1479
		1480	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1481
		1482	=cut
		1483
		1484	our $TLS_CTX;
		1485
		1486	sub TLS_CTX() {
		1487	$TLS_CTX || do {
		1488	require Net::SSLeay;
		1489
		1490	Net::SSLeay::load_error_strings ();
		1491	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1492	Net::SSLeay::randomize ();
		1493
		1494	$TLS_CTX = Net::SSLeay::CTX_new ();
		1495
		1496	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1497
		1498	$TLS_CTX
		1499	}
318	}	1500	}
319		1501
320	=back	1502	=back
321		1503
		1504	=head1 SUBCLASSING AnyEvent::Handle
		1505
		1506	In many cases, you might want to subclass AnyEvent::Handle.
		1507
		1508	To make this easier, a given version of AnyEvent::Handle uses these
		1509	conventions:
		1510
		1511	=over 4
		1512
		1513	=item * all constructor arguments become object members.
		1514
		1515	At least initially, when you pass a C<tls>-argument to the constructor it
		1516	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1517	mutated later on (for example C<tls> will hold the TLS connection object).
		1518
		1519	=item * other object member names are prefixed with an C<_>.
		1520
		1521	All object members not explicitly documented (internal use) are prefixed
		1522	with an underscore character, so the remaining non-C<_>-namespace is free
		1523	for use for subclasses.
		1524
		1525	=item * all members not documented here and not prefixed with an underscore
		1526	are free to use in subclasses.
		1527
		1528	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1529	member variables, but thats just life, at least it is documented.
		1530
		1531	=back
		1532
322	=head1 AUTHOR	1533	=head1 AUTHOR
323		1534
324	Robin Redeker, C<< <elmex at ta-sa.org> >>	1535	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
325
326	=head1 BUGS
327
328	Please report any bugs or feature requests to
329	C<bug-io-anyevent at rt.cpan.org>, or through the web interface at
330	L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=IO-AnyEvent>.
331	I will be notified, and then you'll automatically be notified of progress on
332	your bug as I make changes.
333
334	=head1 SUPPORT
335
336	You can find documentation for this module with the perldoc command.
337
338	perldoc AnyEvent::Handle
339
340	You can also look for information at:
341
342	=over 4
343
344	=item * AnnoCPAN: Annotated CPAN documentation
345
346	L<http://annocpan.org/dist/IO-AnyEvent>
347
348	=item * CPAN Ratings
349
350	L<http://cpanratings.perl.org/d/IO-AnyEvent>
351
352	=item * RT: CPAN's request tracker
353
354	L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=IO-AnyEvent>
355
356	=item * Search CPAN
357
358	L<http://search.cpan.org/dist/IO-AnyEvent>
359
360	=back
361
362	=head1 ACKNOWLEDGEMENTS
363
364	=head1 COPYRIGHT & LICENSE
365
366	Copyright 2008 Robin Redeker, all rights reserved.
367
368	This program is free software; you can redistribute it and/or modify it
369	under the same terms as Perl itself.
370		1536
371	=cut	1537	=cut
372		1538
373	1; # End of AnyEvent::Handle	1539	1; # End of AnyEvent::Handle

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