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Revision 1.1 by elmex, Sun Apr 27 16:56:17 2008 UTC vs.
Revision 1.43 by root, Wed May 28 23:57:38 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	use warnings;	3	no warnings;
4	use strict;	4	use strict;
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);
		12	use Time::HiRes qw(time);
9		13
10	=head1 NAME	14	=head1 NAME
11		15
12	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	16	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
13		17
14	=head1 VERSION
15
16	Version 0.01
17
18	=cut	18	=cut
19		19
20	our $VERSION = '0.01';	20	our $VERSION = '0.04';
21		21
22	=head1 SYNOPSIS	22	=head1 SYNOPSIS
23		23
24	use AnyEvent;	24	use AnyEvent;
25	use AnyEvent::Handle;	25	use AnyEvent::Handle;
26		26
27	my $cv = AnyEvent->condvar;	27	my $cv = AnyEvent->condvar;
28		28
29	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	29	my $handle =
		30	AnyEvent::Handle->new (
		31	fh => \*STDIN,
		32	on_eof => sub {
		33	$cv->broadcast;
		34	},
		35	);
30		36
31	$ae_fh->readlines (sub {	37	# send some request line
		38	$handle->push_write ("getinfo\015\012");
		39
		40	# read the response line
		41	$handle->push_read (line => sub {
32	my ($ae_fh, @lines) = @_;	42	my ($handle, $line) = @_;
33	for (@lines) {	43	warn "read line <$line>\n";
34	chomp;	44	$cv->send;
35	print "Line: $_";	45	});
		46
		47	$cv->recv;
		48
		49	=head1 DESCRIPTION
		50
		51	This module is a helper module to make it easier to do event-based I/O on
		52	filehandles. For utility functions for doing non-blocking connects and accepts
		53	on sockets see L<AnyEvent::Util>.
		54
		55	In the following, when the documentation refers to of "bytes" then this
		56	means characters. As sysread and syswrite are used for all I/O, their
		57	treatment of characters applies to this module as well.
		58
		59	All callbacks will be invoked with the handle object as their first
		60	argument.
		61
		62	=head1 METHODS
		63
		64	=over 4
		65
		66	=item B<new (%args)>
		67
		68	The constructor supports these arguments (all as key => value pairs).
		69
		70	=over 4
		71
		72	=item fh => $filehandle [MANDATORY]
		73
		74	The filehandle this L<AnyEvent::Handle> object will operate on.
		75
		76	NOTE: The filehandle will be set to non-blocking (using
		77	AnyEvent::Util::fh_nonblocking).
		78
		79	=item on_eof => $cb->($handle)
		80
		81	Set the callback to be called on EOF.
		82
		83	While not mandatory, it is highly recommended to set an eof callback,
		84	otherwise you might end up with a closed socket while you are still
		85	waiting for data.
		86
		87	=item on_error => $cb->($handle)
		88
		89	This is the fatal error callback, that is called when, well, a fatal error
		90	occurs, such as not being able to resolve the hostname, failure to connect
		91	or a read error.
		92
		93	The object will not be in a usable state when this callback has been
		94	called.
		95
		96	On callback entrance, the value of C<$!> contains the operating system
		97	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
		98
		99	The callback should throw an exception. If it returns, then
		100	AnyEvent::Handle will C<croak> for you.
		101
		102	While not mandatory, it is I<highly> recommended to set this callback, as
		103	you will not be notified of errors otherwise. The default simply calls
		104	die.
		105
		106	=item on_read => $cb->($handle)
		107
		108	This sets the default read callback, which is called when data arrives
		109	and no read request is in the queue.
		110
		111	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		112	method or access the C<$handle->{rbuf}> member directly.
		113
		114	When an EOF condition is detected then AnyEvent::Handle will first try to
		115	feed all the remaining data to the queued callbacks and C<on_read> before
		116	calling the C<on_eof> callback. If no progress can be made, then a fatal
		117	error will be raised (with C<$!> set to C<EPIPE>).
		118
		119	=item on_drain => $cb->($handle)
		120
		121	This sets the callback that is called when the write buffer becomes empty
		122	(or when the callback is set and the buffer is empty already).
		123
		124	To append to the write buffer, use the C<< ->push_write >> method.
		125
		126	=item timeout => $fractional_seconds
		127
		128	If non-zero, then this enables an "inactivity" timeout: whenever this many
		129	seconds pass without a successful read or write on the underlying file
		130	handle, the C<on_timeout> callback will be invoked (and if that one is
		131	missing, an C<ETIMEDOUT> errror will be raised).
		132
		133	Note that timeout processing is also active when you currently do not have
		134	any outstanding read or write requests: If you plan to keep the connection
		135	idle then you should disable the timout temporarily or ignore the timeout
		136	in the C<on_timeout> callback.
		137
		138	Zero (the default) disables this timeout.
		139
		140	=item on_timeout => $cb->($handle)
		141
		142	Called whenever the inactivity timeout passes. If you return from this
		143	callback, then the timeout will be reset as if some activity had happened,
		144	so this condition is not fatal in any way.
		145
		146	=item rbuf_max => <bytes>
		147
		148	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		149	when the read buffer ever (strictly) exceeds this size. This is useful to
		150	avoid denial-of-service attacks.
		151
		152	For example, a server accepting connections from untrusted sources should
		153	be configured to accept only so-and-so much data that it cannot act on
		154	(for example, when expecting a line, an attacker could send an unlimited
		155	amount of data without a callback ever being called as long as the line
		156	isn't finished).
		157
		158	=item read_size => <bytes>
		159
		160	The default read block size (the amount of bytes this module will try to read
		161	on each [loop iteration). Default: C<4096>.
		162
		163	=item low_water_mark => <bytes>
		164
		165	Sets the amount of bytes (default: C<0>) that make up an "empty" write
		166	buffer: If the write reaches this size or gets even samller it is
		167	considered empty.
		168
		169	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		170
		171	When this parameter is given, it enables TLS (SSL) mode, that means it
		172	will start making tls handshake and will transparently encrypt/decrypt
		173	data.
		174
		175	TLS mode requires Net::SSLeay to be installed (it will be loaded
		176	automatically when you try to create a TLS handle).
		177
		178	For the TLS server side, use C<accept>, and for the TLS client side of a
		179	connection, use C<connect> mode.
		180
		181	You can also provide your own TLS connection object, but you have
		182	to make sure that you call either C<Net::SSLeay::set_connect_state>
		183	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		184	AnyEvent::Handle.
		185
		186	See the C<starttls> method if you need to start TLs negotiation later.
		187
		188	=item tls_ctx => $ssl_ctx
		189
		190	Use the given Net::SSLeay::CTX object to create the new TLS connection
		191	(unless a connection object was specified directly). If this parameter is
		192	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		193
		194	=item json => JSON or JSON::XS object
		195
		196	This is the json coder object used by the C<json> read and write types.
		197
		198	If you don't supply it, then AnyEvent::Handle will create and use a
		199	suitable one, which will write and expect UTF-8 encoded JSON texts.
		200
		201	Note that you are responsible to depend on the JSON module if you want to
		202	use this functionality, as AnyEvent does not have a dependency itself.
		203
		204	=item filter_r => $cb
		205
		206	=item filter_w => $cb
		207
		208	These exist, but are undocumented at this time.
		209
		210	=back
		211
		212	=cut
		213
		214	sub new {
		215	my $class = shift;
		216
		217	my $self = bless { @_ }, $class;
		218
		219	$self->{fh} or Carp::croak "mandatory argument fh is missing";
		220
		221	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
		222
		223	if ($self->{tls}) {
		224	require Net::SSLeay;
		225	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		226	}
		227
		228	# $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; # nop
		229	# $self->on_error (delete $self->{on_error}) if $self->{on_error}; # nop
		230	# $self->on_read (delete $self->{on_read} ) if $self->{on_read}; # nop
		231	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
		232
		233	$self->{_activity} = time;
		234	$self->_timeout;
		235
		236	$self->start_read;
		237
		238	$self
		239	}
		240
		241	sub _shutdown {
		242	my ($self) = @_;
		243
		244	delete $self->{_rw};
		245	delete $self->{_ww};
		246	delete $self->{fh};
		247	}
		248
		249	sub error {
		250	my ($self) = @_;
		251
		252	{
		253	local $!;
		254	$self->_shutdown;
		255	}
		256
		257	$self->{on_error}($self)
		258	if $self->{on_error};
		259
		260	Carp::croak "AnyEvent::Handle uncaught fatal error: $!";
		261	}
		262
		263	=item $fh = $handle->fh
		264
		265	This method returns the file handle of the L<AnyEvent::Handle> object.
		266
		267	=cut
		268
		269	sub fh { $_[0]{fh} }
		270
		271	=item $handle->on_error ($cb)
		272
		273	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
		274
		275	=cut
		276
		277	sub on_error {
		278	$_[0]{on_error} = $_[1];
		279	}
		280
		281	=item $handle->on_eof ($cb)
		282
		283	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
		284
		285	=cut
		286
		287	sub on_eof {
		288	$_[0]{on_eof} = $_[1];
		289	}
		290
		291	=item $handle->on_timeout ($cb)
		292
		293	Replace the current C<on_timeout> callback, or disables the callback
		294	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		295	argument.
		296
		297	=cut
		298
		299	sub on_timeout {
		300	$_[0]{on_timeout} = $_[1];
		301	}
		302
		303	#############################################################################
		304
		305	=item $handle->timeout ($seconds)
		306
		307	Configures (or disables) the inactivity timeout.
		308
		309	=cut
		310
		311	sub timeout {
		312	my ($self, $timeout) = @_;
		313
		314	$self->{timeout} = $timeout;
		315	$self->_timeout;
		316	}
		317
		318	# reset the timeout watcher, as neccessary
		319	# also check for time-outs
		320	sub _timeout {
		321	my ($self) = @_;
		322
		323	if ($self->{timeout}) {
		324	my $NOW = time;
		325
		326	# when would the timeout trigger?
		327	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		328
		329	warn "next to in $after\n";#d#
		330
		331	# now or in the past already?
		332	if ($after <= 0) {
		333	$self->{_activity} = $NOW;
		334
		335	if ($self->{on_timeout}) {
		336	$self->{on_timeout}->($self);
		337	} else {
		338	$! = Errno::ETIMEDOUT;
		339	$self->error;
		340	}
		341
		342	# callbakx could have changed timeout value, optimise
		343	return unless $self->{timeout};
		344
		345	# calculate new after
		346	$after = $self->{timeout};
36	}	347	}
37	$cv->broadcast;	348
		349	Scalar::Util::weaken $self;
		350
		351	warn "after $after\n";#d#
		352	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		353	delete $self->{_tw};
		354	$self->_timeout;
		355	});
		356	} else {
		357	delete $self->{_tw};
		358	}
		359	}
		360
		361	#############################################################################
		362
		363	=back
		364
		365	=head2 WRITE QUEUE
		366
		367	AnyEvent::Handle manages two queues per handle, one for writing and one
		368	for reading.
		369
		370	The write queue is very simple: you can add data to its end, and
		371	AnyEvent::Handle will automatically try to get rid of it for you.
		372
		373	When data could be written and the write buffer is shorter then the low
		374	water mark, the C<on_drain> callback will be invoked.
		375
		376	=over 4
		377
		378	=item $handle->on_drain ($cb)
		379
		380	Sets the C<on_drain> callback or clears it (see the description of
		381	C<on_drain> in the constructor).
		382
		383	=cut
		384
		385	sub on_drain {
		386	my ($self, $cb) = @_;
		387
		388	$self->{on_drain} = $cb;
		389
		390	$cb->($self)
		391	if $cb && $self->{low_water_mark} >= length $self->{wbuf};
		392	}
		393
		394	=item $handle->push_write ($data)
		395
		396	Queues the given scalar to be written. You can push as much data as you
		397	want (only limited by the available memory), as C<AnyEvent::Handle>
		398	buffers it independently of the kernel.
		399
		400	=cut
		401
		402	sub _drain_wbuf {
		403	my ($self) = @_;
		404
		405	if (!$self->{_ww} && length $self->{wbuf}) {
		406
		407	Scalar::Util::weaken $self;
		408
		409	my $cb = sub {
		410	my $len = syswrite $self->{fh}, $self->{wbuf};
		411
		412	if ($len >= 0) {
		413	substr $self->{wbuf}, 0, $len, "";
		414
		415	$self->{_activity} = time;
		416
		417	$self->{on_drain}($self)
		418	if $self->{low_water_mark} >= length $self->{wbuf}
		419	&& $self->{on_drain};
		420
		421	delete $self->{_ww} unless length $self->{wbuf};
		422	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		423	$self->error;
		424	}
		425	};
		426
		427	# try to write data immediately
		428	$cb->();
		429
		430	# if still data left in wbuf, we need to poll
		431	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
		432	if length $self->{wbuf};
		433	};
		434	}
		435
		436	our %WH;
		437
		438	sub register_write_type($$) {
		439	$WH{$_[0]} = $_[1];
		440	}
		441
		442	sub push_write {
		443	my $self = shift;
		444
		445	if (@_ > 1) {
		446	my $type = shift;
		447
		448	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		449	->($self, @_);
		450	}
		451
		452	if ($self->{filter_w}) {
		453	$self->{filter_w}->($self, \$_[0]);
		454	} else {
		455	$self->{wbuf} .= $_[0];
		456	$self->_drain_wbuf;
		457	}
		458	}
		459
		460	=item $handle->push_write (type => @args)
		461
		462	=item $handle->unshift_write (type => @args)
		463
		464	Instead of formatting your data yourself, you can also let this module do
		465	the job by specifying a type and type-specific arguments.
		466
		467	Predefined types are (if you have ideas for additional types, feel free to
		468	drop by and tell us):
		469
		470	=over 4
		471
		472	=item netstring => $string
		473
		474	Formats the given value as netstring
		475	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		476
		477	=back
		478
		479	=cut
		480
		481	register_write_type netstring => sub {
		482	my ($self, $string) = @_;
		483
		484	sprintf "%d:%s,", (length $string), $string
		485	};
		486
		487	=item json => $array_or_hashref
		488
		489	Encodes the given hash or array reference into a JSON object. Unless you
		490	provide your own JSON object, this means it will be encoded to JSON text
		491	in UTF-8.
		492
		493	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		494	one end of a handle and read them at the other end without using any
		495	additional framing.
		496
		497	The generated JSON text is guaranteed not to contain any newlines: While
		498	this module doesn't need delimiters after or between JSON texts to be
		499	able to read them, many other languages depend on that.
		500
		501	A simple RPC protocol that interoperates easily with others is to send
		502	JSON arrays (or objects, although arrays are usually the better choice as
		503	they mimic how function argument passing works) and a newline after each
		504	JSON text:
		505
		506	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		507	$handle->push_write ("\012");
		508
		509	An AnyEvent::Handle receiver would simply use the C<json> read type and
		510	rely on the fact that the newline will be skipped as leading whitespace:
		511
		512	$handle->push_read (json => sub { my $array = $_[1]; ... });
		513
		514	Other languages could read single lines terminated by a newline and pass
		515	this line into their JSON decoder of choice.
		516
		517	=cut
		518
		519	register_write_type json => sub {
		520	my ($self, $ref) = @_;
		521
		522	require JSON;
		523
		524	$self->{json} ? $self->{json}->encode ($ref)
		525	: JSON::encode_json ($ref)
		526	};
		527
		528	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		529
		530	This function (not method) lets you add your own types to C<push_write>.
		531	Whenever the given C<type> is used, C<push_write> will invoke the code
		532	reference with the handle object and the remaining arguments.
		533
		534	The code reference is supposed to return a single octet string that will
		535	be appended to the write buffer.
		536
		537	Note that this is a function, and all types registered this way will be
		538	global, so try to use unique names.
		539
		540	=cut
		541
		542	#############################################################################
		543
		544	=back
		545
		546	=head2 READ QUEUE
		547
		548	AnyEvent::Handle manages two queues per handle, one for writing and one
		549	for reading.
		550
		551	The read queue is more complex than the write queue. It can be used in two
		552	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		553	a queue.
		554
		555	In the simple case, you just install an C<on_read> callback and whenever
		556	new data arrives, it will be called. You can then remove some data (if
		557	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want
		558	or not.
		559
		560	In the more complex case, you want to queue multiple callbacks. In this
		561	case, AnyEvent::Handle will call the first queued callback each time new
		562	data arrives and removes it when it has done its job (see C<push_read>,
		563	below).
		564
		565	This way you can, for example, push three line-reads, followed by reading
		566	a chunk of data, and AnyEvent::Handle will execute them in order.
		567
		568	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		569	the specified number of bytes which give an XML datagram.
		570
		571	# in the default state, expect some header bytes
		572	$handle->on_read (sub {
		573	# some data is here, now queue the length-header-read (4 octets)
		574	shift->unshift_read_chunk (4, sub {
		575	# header arrived, decode
		576	my $len = unpack "N", $_[1];
		577
		578	# now read the payload
		579	shift->unshift_read_chunk ($len, sub {
		580	my $xml = $_[1];
		581	# handle xml
		582	});
		583	});
38	});	584	});
39		585
40	$cv->wait;	586	Example 2: Implement a client for a protocol that replies either with
		587	"OK" and another line or "ERROR" for one request, and 64 bytes for the
		588	second request. Due tot he availability of a full queue, we can just
		589	pipeline sending both requests and manipulate the queue as necessary in
		590	the callbacks:
41		591
42	=head1 DESCRIPTION	592	# request one
		593	$handle->push_write ("request 1\015\012");
43		594
44	This module is a helper module to make it easier to do non-blocking I/O	595	# we expect "ERROR" or "OK" as response, so push a line read
45	on filehandles (and sockets, see L<AnyEvent::Socket>).	596	$handle->push_read_line (sub {
		597	# if we got an "OK", we have to _prepend_ another line,
		598	# so it will be read before the second request reads its 64 bytes
		599	# which are already in the queue when this callback is called
		600	# we don't do this in case we got an error
		601	if ($_[1] eq "OK") {
		602	$_[0]->unshift_read_line (sub {
		603	my $response = $_[1];
		604	...
		605	});
		606	}
		607	});
46		608
47	The event loop is provided by L<AnyEvent>.	609	# request two
		610	$handle->push_write ("request 2\015\012");
48		611
49	=head1 METHODS	612	# simply read 64 bytes, always
		613	$handle->push_read_chunk (64, sub {
		614	my $response = $_[1];
		615	...
		616	});
50		617
51	=over 4	618	=over 4
52		619
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	620	=cut
73		621
74	sub new {	622	sub _drain_rbuf {
75	my $this = shift;
76	my $class = ref($this) || $this;
77	my $self = {	623	my ($self) = @_;
78	read_block_size => 4096,	624
79	rbuf => '',	625	if (
80	@_	626	defined $self->{rbuf_max}
		627	&& $self->{rbuf_max} < length $self->{rbuf}
		628	) {
		629	$! = &Errno::ENOSPC;
		630	$self->error;
81	};	631	}
82	bless $self, $class;
83		632
84	$self->{fh}->blocking (0) if $self->{fh};	633	return if $self->{in_drain};
		634	local $self->{in_drain} = 1;
85		635
86	if ($self->{on_read}) {	636	while (my $len = length $self->{rbuf}) {
87	$self->on_read ($self->{on_read});	637	no strict 'refs';
		638	if (my $cb = shift @{ $self->{_queue} }) {
		639	unless ($cb->($self)) {
		640	if ($self->{_eof}) {
		641	# no progress can be made (not enough data and no data forthcoming)
		642	$! = &Errno::EPIPE;
		643	$self->error;
		644	}
88		645
		646	unshift @{ $self->{_queue} }, $cb;
		647	return;
		648	}
89	} elsif ($self->{on_readline}) {	649	} elsif ($self->{on_read}) {
90	$self->readlines ($self->{on_readline});	650	$self->{on_read}($self);
91	}
92		651
93	return $self	652	if (
94	}	653	$self->{_eof} # if no further data will arrive
		654	&& $len == length $self->{rbuf} # and no data has been consumed
		655	&& !@{ $self->{_queue} } # and the queue is still empty
		656	&& $self->{on_read} # and we still want to read data
		657	) {
		658	# then no progress can be made
		659	$! = &Errno::EPIPE;
		660	$self->error;
		661	}
		662	} else {
		663	# read side becomes idle
		664	delete $self->{_rw};
		665	return;
		666	}
		667	}
95		668
96	=item B<fh>	669	if ($self->{_eof}) {
		670	$self->_shutdown;
		671	$self->{on_eof}($self)
		672	if $self->{on_eof};
		673	}
		674	}
97		675
98	This method returns the filehandle of the L<AnyEvent::Handle> object.	676	=item $handle->on_read ($cb)
99		677
100	=cut	678	This replaces the currently set C<on_read> callback, or clears it (when
101		679	the new callback is C<undef>). See the description of C<on_read> in the
102	sub fh { $_[0]->{fh} }	680	constructor.
103
104	=item B<on_read ($callback)>
105
106	This method installs a C<$callback> that will be called
107	when new data arrived. You can access the read buffer via the C<rbuf>
108	method (see below).
109
110	The first argument of the C<$callback> will be the L<AnyEvent::Handle> object.
111		681
112	=cut	682	=cut
113		683
114	sub on_read {	684	sub on_read {
115	my ($self, $cb) = @_;	685	my ($self, $cb) = @_;
		686
116	$self->{on_read} = $cb;	687	$self->{on_read} = $cb;
		688	}
117		689
118	unless (defined $self->{on_read}) {	690	=item $handle->rbuf
119	delete $self->{on_read_w};	691
120	return;	692	Returns the read buffer (as a modifiable lvalue).
		693
		694	You can access the read buffer directly as the C<< ->{rbuf} >> member, if
		695	you want.
		696
		697	NOTE: The read buffer should only be used or modified if the C<on_read>,
		698	C<push_read> or C<unshift_read> methods are used. The other read methods
		699	automatically manage the read buffer.
		700
		701	=cut
		702
		703	sub rbuf : lvalue {
		704	$_[0]{rbuf}
		705	}
		706
		707	=item $handle->push_read ($cb)
		708
		709	=item $handle->unshift_read ($cb)
		710
		711	Append the given callback to the end of the queue (C<push_read>) or
		712	prepend it (C<unshift_read>).
		713
		714	The callback is called each time some additional read data arrives.
		715
		716	It must check whether enough data is in the read buffer already.
		717
		718	If not enough data is available, it must return the empty list or a false
		719	value, in which case it will be called repeatedly until enough data is
		720	available (or an error condition is detected).
		721
		722	If enough data was available, then the callback must remove all data it is
		723	interested in (which can be none at all) and return a true value. After returning
		724	true, it will be removed from the queue.
		725
		726	=cut
		727
		728	our %RH;
		729
		730	sub register_read_type($$) {
		731	$RH{$_[0]} = $_[1];
		732	}
		733
		734	sub push_read {
		735	my $self = shift;
		736	my $cb = pop;
		737
		738	if (@_) {
		739	my $type = shift;
		740
		741	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		742	->($self, $cb, @_);
		743	}
		744
		745	push @{ $self->{_queue} }, $cb;
		746	$self->_drain_rbuf;
		747	}
		748
		749	sub unshift_read {
		750	my $self = shift;
		751	my $cb = pop;
		752
		753	if (@_) {
		754	my $type = shift;
		755
		756	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		757	->($self, $cb, @_);
		758	}
		759
		760
		761	unshift @{ $self->{_queue} }, $cb;
		762	$self->_drain_rbuf;
		763	}
		764
		765	=item $handle->push_read (type => @args, $cb)
		766
		767	=item $handle->unshift_read (type => @args, $cb)
		768
		769	Instead of providing a callback that parses the data itself you can chose
		770	between a number of predefined parsing formats, for chunks of data, lines
		771	etc.
		772
		773	Predefined types are (if you have ideas for additional types, feel free to
		774	drop by and tell us):
		775
		776	=over 4
		777
		778	=item chunk => $octets, $cb->($handle, $data)
		779
		780	Invoke the callback only once C<$octets> bytes have been read. Pass the
		781	data read to the callback. The callback will never be called with less
		782	data.
		783
		784	Example: read 2 bytes.
		785
		786	$handle->push_read (chunk => 2, sub {
		787	warn "yay ", unpack "H*", $_[1];
121	}	788	});
122		789
123	$self->{on_read_w} =	790	=cut
124	AnyEvent->io (poll => 'r', fh => $self->{fh}, cb => sub {	791
125	#d# warn "READ:[$self->{read_size}] $self->{read_block_size} : ".length ($self->{rbuf})."\n";	792	register_read_type chunk => sub {
126	my $rbuf_len = length $self->{rbuf};	793	my ($self, $cb, $len) = @_;
127	my $l;	794
128	if (defined $self->{read_size}) {	795	sub {
129	$l = sysread $self->{fh}, $self->{rbuf},	796	$len <= length $_[0]{rbuf} or return;
130	($self->{read_size} - $rbuf_len), $rbuf_len;	797	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
131	} else {	798	1
132	$l = sysread $self->{fh}, $self->{rbuf}, $self->{read_block_size}, $rbuf_len;	799	}
		800	};
		801
		802	# compatibility with older API
		803	sub push_read_chunk {
		804	$_[0]->push_read (chunk => $_[1], $_[2]);
		805	}
		806
		807	sub unshift_read_chunk {
		808	$_[0]->unshift_read (chunk => $_[1], $_[2]);
		809	}
		810
		811	=item line => [$eol, ]$cb->($handle, $line, $eol)
		812
		813	The callback will be called only once a full line (including the end of
		814	line marker, C<$eol>) has been read. This line (excluding the end of line
		815	marker) will be passed to the callback as second argument (C<$line>), and
		816	the end of line marker as the third argument (C<$eol>).
		817
		818	The end of line marker, C<$eol>, can be either a string, in which case it
		819	will be interpreted as a fixed record end marker, or it can be a regex
		820	object (e.g. created by C<qr>), in which case it is interpreted as a
		821	regular expression.
		822
		823	The end of line marker argument C<$eol> is optional, if it is missing (NOT
		824	undef), then C<qr|\015?\012|> is used (which is good for most internet
		825	protocols).
		826
		827	Partial lines at the end of the stream will never be returned, as they are
		828	not marked by the end of line marker.
		829
		830	=cut
		831
		832	register_read_type line => sub {
		833	my ($self, $cb, $eol) = @_;
		834
		835	$eol = qr|(\015?\012)| if @_ < 3;
		836	$eol = quotemeta $eol unless ref $eol;
		837	$eol = qr|^(.*?)($eol)|s;
		838
		839	sub {
		840	$_[0]{rbuf} =~ s/$eol// or return;
		841
		842	$cb->($_[0], $1, $2);
		843	1
		844	}
		845	};
		846
		847	# compatibility with older API
		848	sub push_read_line {
		849	my $self = shift;
		850	$self->push_read (line => @_);
		851	}
		852
		853	sub unshift_read_line {
		854	my $self = shift;
		855	$self->unshift_read (line => @_);
		856	}
		857
		858	=item netstring => $cb->($handle, $string)
		859
		860	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		861
		862	Throws an error with C<$!> set to EBADMSG on format violations.
		863
		864	=cut
		865
		866	register_read_type netstring => sub {
		867	my ($self, $cb) = @_;
		868
		869	sub {
		870	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		871	if ($_[0]{rbuf} =~ /[^0-9]/) {
		872	$! = &Errno::EBADMSG;
		873	$self->error;
133	}	874	}
134	#d# warn "READL $l [$self->{rbuf}]\n";	875	return;
		876	}
135		877
136	if (not defined $l) {	878	my $len = $1;
137	return if $! == EAGAIN || $! == EINTR;
138	$self->{on_error}->($self, $!) if $self->{on_error};
139	delete $self->{on_read_w};
140		879
141	} elsif ($l == 0) {	880	$self->unshift_read (chunk => $len, sub {
142	$self->{on_eof}->($self) if $self->{on_eof};	881	my $string = $_[1];
143	delete $self->{on_read_w};	882	$_[0]->unshift_read (chunk => 1, sub {
144		883	if ($_[1] eq ",") {
		884	$cb->($_[0], $string);
145	} else {	885	} else {
146	$self->{on_read}->($self);	886	$! = &Errno::EBADMSG;
		887	$self->error;
		888	}
		889	});
		890	});
		891
		892	1
		893	}
		894	};
		895
		896	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		897
		898	Makes a regex match against the regex object C<$accept> and returns
		899	everything up to and including the match.
		900
		901	Example: read a single line terminated by '\n'.
		902
		903	$handle->push_read (regex => qr<\n>, sub { ... });
		904
		905	If C<$reject> is given and not undef, then it determines when the data is
		906	to be rejected: it is matched against the data when the C<$accept> regex
		907	does not match and generates an C<EBADMSG> error when it matches. This is
		908	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		909	receive buffer overflow).
		910
		911	Example: expect a single decimal number followed by whitespace, reject
		912	anything else (not the use of an anchor).
		913
		914	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		915
		916	If C<$skip> is given and not C<undef>, then it will be matched against
		917	the receive buffer when neither C<$accept> nor C<$reject> match,
		918	and everything preceding and including the match will be accepted
		919	unconditionally. This is useful to skip large amounts of data that you
		920	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		921	have to start matching from the beginning. This is purely an optimisation
		922	and is usually worth only when you expect more than a few kilobytes.
		923
		924	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		925	expect the header to be very large (it isn't in practise, but...), we use
		926	a skip regex to skip initial portions. The skip regex is tricky in that
		927	it only accepts something not ending in either \015 or \012, as these are
		928	required for the accept regex.
		929
		930	$handle->push_read (regex =>
		931	qr<\015\012\015\012>,
		932	undef, # no reject
		933	qr<^.*[^\015\012]>,
		934	sub { ... });
		935
		936	=cut
		937
		938	register_read_type regex => sub {
		939	my ($self, $cb, $accept, $reject, $skip) = @_;
		940
		941	my $data;
		942	my $rbuf = \$self->{rbuf};
		943
		944	sub {
		945	# accept
		946	if ($$rbuf =~ $accept) {
		947	$data .= substr $$rbuf, 0, $+[0], "";
		948	$cb->($self, $data);
		949	return 1;
		950	}
		951
		952	# reject
		953	if ($reject && $$rbuf =~ $reject) {
		954	$! = &Errno::EBADMSG;
		955	$self->error;
		956	}
		957
		958	# skip
		959	if ($skip && $$rbuf =~ $skip) {
		960	$data .= substr $$rbuf, 0, $+[0], "";
		961	}
		962
		963	()
		964	}
		965	};
		966
		967	=item json => $cb->($handle, $hash_or_arrayref)
		968
		969	Reads a JSON object or array, decodes it and passes it to the callback.
		970
		971	If a C<json> object was passed to the constructor, then that will be used
		972	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		973
		974	This read type uses the incremental parser available with JSON version
		975	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		976	dependency on your own: this module will load the JSON module, but
		977	AnyEvent does not depend on it itself.
		978
		979	Since JSON texts are fully self-delimiting, the C<json> read and write
		980	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		981	the C<json> write type description, above, for an actual example.
		982
		983	=cut
		984
		985	register_read_type json => sub {
		986	my ($self, $cb, $accept, $reject, $skip) = @_;
		987
		988	require JSON;
		989
		990	my $data;
		991	my $rbuf = \$self->{rbuf};
		992
		993	my $json = $self->{json} ||= JSON->new->utf8;
		994
		995	sub {
		996	my $ref = $json->incr_parse ($self->{rbuf});
		997
		998	if ($ref) {
		999	$self->{rbuf} = $json->incr_text;
		1000	$json->incr_text = "";
		1001	$cb->($self, $ref);
		1002
		1003	1
		1004	} else {
		1005	$self->{rbuf} = "";
		1006	()
		1007	}
		1008	}
		1009	};
		1010
		1011	=back
		1012
		1013	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1014
		1015	This function (not method) lets you add your own types to C<push_read>.
		1016
		1017	Whenever the given C<type> is used, C<push_read> will invoke the code
		1018	reference with the handle object, the callback and the remaining
		1019	arguments.
		1020
		1021	The code reference is supposed to return a callback (usually a closure)
		1022	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1023
		1024	It should invoke the passed callback when it is done reading (remember to
		1025	pass C<$handle> as first argument as all other callbacks do that).
		1026
		1027	Note that this is a function, and all types registered this way will be
		1028	global, so try to use unique names.
		1029
		1030	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1031	search for C<register_read_type>)).
		1032
		1033	=item $handle->stop_read
		1034
		1035	=item $handle->start_read
		1036
		1037	In rare cases you actually do not want to read anything from the
		1038	socket. In this case you can call C<stop_read>. Neither C<on_read> no
		1039	any queued callbacks will be executed then. To start reading again, call
		1040	C<start_read>.
		1041
		1042	=cut
		1043
		1044	sub stop_read {
		1045	my ($self) = @_;
		1046
		1047	delete $self->{_rw};
		1048	}
		1049
		1050	sub start_read {
		1051	my ($self) = @_;
		1052
		1053	unless ($self->{_rw} || $self->{_eof}) {
		1054	Scalar::Util::weaken $self;
		1055
		1056	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1057	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
		1058	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1059
		1060	if ($len > 0) {
		1061	$self->{_activity} = time;
		1062
		1063	$self->{filter_r}
		1064	? $self->{filter_r}->($self, $rbuf)
		1065	: $self->_drain_rbuf;
		1066
		1067	} elsif (defined $len) {
		1068	delete $self->{_rw};
		1069	delete $self->{_ww};
		1070	delete $self->{_tw};
		1071	$self->{_eof} = 1;
		1072	$self->_drain_rbuf;
		1073
		1074	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1075	return $self->error;
147	}	1076	}
148	});	1077	});
		1078	}
149	}	1079	}
150		1080
151	=item B<on_error ($callback)>	1081	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, $cb) = @_;	1082	my ($self) = @_;
201		1083
202	$self->{read_cb} = $cb;	1084	if (length $self->{_tls_wbuf}) {
203	my $old_blk_size = $self->{read_block_size};	1085	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
204	$self->{read_block_size} = $len;	1086	substr $self->{_tls_wbuf}, 0, $len, "";
205
206	$self->on_read (sub {
207	#d# warn "OFOFO $len || ".length($_[0]->{rbuf})."||\n";
208
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	}	1087	}
		1088	}
		1089
		1090	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1091	$self->{wbuf} .= $buf;
		1092	$self->_drain_wbuf;
		1093	}
		1094
		1095	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
		1096	$self->{rbuf} .= $buf;
		1097	$self->_drain_rbuf;
		1098	}
		1099
		1100	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1101
		1102	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1103	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1104	$self->error;
		1105	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1106	$! = &Errno::EIO;
		1107	$self->error;
		1108	}
		1109
		1110	# all others are fine for our purposes
		1111	}
		1112	}
		1113
		1114	=item $handle->starttls ($tls[, $tls_ctx])
		1115
		1116	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1117	object is created, you can also do that at a later time by calling
		1118	C<starttls>.
		1119
		1120	The first argument is the same as the C<tls> constructor argument (either
		1121	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1122
		1123	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1124	used when AnyEvent::Handle has to create its own TLS connection object.
		1125
		1126	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1127	call and can be used or changed to your liking. Note that the handshake
		1128	might have already started when this function returns.
		1129
		1130	=cut
		1131
		1132	# TODO: maybe document...
		1133	sub starttls {
		1134	my ($self, $ssl, $ctx) = @_;
		1135
		1136	$self->stoptls;
		1137
		1138	if ($ssl eq "accept") {
		1139	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1140	Net::SSLeay::set_accept_state ($ssl);
		1141	} elsif ($ssl eq "connect") {
		1142	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1143	Net::SSLeay::set_connect_state ($ssl);
		1144	}
		1145
		1146	$self->{tls} = $ssl;
		1147
		1148	# basically, this is deep magic (because SSL_read should have the same issues)
		1149	# but the openssl maintainers basically said: "trust us, it just works".
		1150	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1151	# and mismaintained ssleay-module doesn't even offer them).
		1152	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1153	Net::SSLeay::CTX_set_mode ($self->{tls},
		1154	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1155	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1156
		1157	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1158	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1159
		1160	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1161
		1162	$self->{filter_w} = sub {
		1163	$_[0]{_tls_wbuf} .= ${$_[1]};
		1164	&_dotls;
214	});	1165	};
215	}	1166	$self->{filter_r} = sub {
216		1167	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
217	=item B<readlines ($callback)>	1168	&_dotls;
218
219	=item B<readlines ($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	});	1169	};
248	}	1170	}
249		1171
250	=item B<write ($data)>	1172	=item $handle->stoptls
251		1173
252	=item B<write ($callback)>	1174	Destroys the SSL connection, if any. Partial read or write data will be
		1175	lost.
253		1176
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	1177	=cut
261		1178
262	sub write {	1179	sub stoptls {
263	my ($self, $data, $cb) = @_;
264	if (ref $data) { $cb = $data; undef $data }
265	push @{$self->{write_bufs}}, [$data, $cb];
266	$self->_check_writer;
267	}
268
269	sub _check_writer {
270	my ($self) = @_;	1180	my ($self) = @_;
271		1181
272	if ($self->{write_w}) {	1182	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		1183
282	my $wba = shift @{$self->{write_bufs}}	1184	delete $self->{_rbio};
283	or return;	1185	delete $self->{_wbio};
284		1186	delete $self->{_tls_wbuf};
285	unless (defined $wba->[0]) {	1187	delete $self->{filter_r};
286	$wba->[1]->($self) if $wba->[1];
287	$self->_check_writer;
288	return;
289	}
290
291	$self->{wbuf} = $wba->[0];
292	$self->{write_cb} = $wba->[1];
293
294	$self->{write_w} =
295	AnyEvent->io (poll => 'w', fh => $self->{fh}, cb => sub {
296	my $l = syswrite $self->{fh}, $self->{wbuf}, length $self->{wbuf};
297
298	if (not defined $l) {
299	return if $! == EAGAIN || $! == EINTR;
300	delete $self->{write_w};	1188	delete $self->{filter_w};
		1189	}
301		1190
302	$self->{on_error}->($self, $!) if $self->{on_error};	1191	sub DESTROY {
		1192	my $self = shift;
303		1193
304	} else {	1194	$self->stoptls;
305	substr $self->{wbuf}, 0, $l, '';	1195	}
306		1196
307	if (length ($self->{wbuf}) == 0) {	1197	=item AnyEvent::Handle::TLS_CTX
308	$self->{write_cb}->($self) if $self->{write_cb};
309		1198
310	delete $self->{write_w};	1199	This function creates and returns the Net::SSLeay::CTX object used by
311	delete $self->{wbuf};	1200	default for TLS mode.
312	delete $self->{write_cb};
313		1201
314	$self->_check_writer;	1202	The context is created like this:
315	}	1203
316	}	1204	Net::SSLeay::load_error_strings;
317	});	1205	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1206	Net::SSLeay::randomize;
		1207
		1208	my $CTX = Net::SSLeay::CTX_new;
		1209
		1210	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1211
		1212	=cut
		1213
		1214	our $TLS_CTX;
		1215
		1216	sub TLS_CTX() {
		1217	$TLS_CTX || do {
		1218	require Net::SSLeay;
		1219
		1220	Net::SSLeay::load_error_strings ();
		1221	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1222	Net::SSLeay::randomize ();
		1223
		1224	$TLS_CTX = Net::SSLeay::CTX_new ();
		1225
		1226	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1227
		1228	$TLS_CTX
		1229	}
318	}	1230	}
319		1231
320	=back	1232	=back
321		1233
		1234	=head1 SUBCLASSING AnyEvent::Handle
		1235
		1236	In many cases, you might want to subclass AnyEvent::Handle.
		1237
		1238	To make this easier, a given version of AnyEvent::Handle uses these
		1239	conventions:
		1240
		1241	=over 4
		1242
		1243	=item * all constructor arguments become object members.
		1244
		1245	At least initially, when you pass a C<tls>-argument to the constructor it
		1246	will end up in C<< $handle->{tls} >>. Those members might be changes or
		1247	mutated later on (for example C<tls> will hold the TLS connection object).
		1248
		1249	=item * other object member names are prefixed with an C<_>.
		1250
		1251	All object members not explicitly documented (internal use) are prefixed
		1252	with an underscore character, so the remaining non-C<_>-namespace is free
		1253	for use for subclasses.
		1254
		1255	=item * all members not documented here and not prefixed with an underscore
		1256	are free to use in subclasses.
		1257
		1258	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1259	member variables, but thats just life, at least it is documented.
		1260
		1261	=back
		1262
322	=head1 AUTHOR	1263	=head1 AUTHOR
323		1264
324	Robin Redeker, C<< <elmex at ta-sa.org> >>	1265	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		1266
371	=cut	1267	=cut
372		1268
373	1; # End of AnyEvent::Handle	1269	1; # End of AnyEvent::Handle

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