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Revision 1.17 by root, Sat May 24 04:17:45 2008 UTC vs.
Revision 1.207 by root, Mon Nov 15 22:29:36 2010 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict;
5
6	use AnyEvent ();
7	use AnyEvent::Util ();
8	use Scalar::Util ();
9	use Carp ();
10	use Fcntl ();
11	use Errno qw/EAGAIN EINTR/;
12
13	=head1 NAME	1	=head1 NAME
14		2
15	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
16
17	This module is experimental.
18
19	=cut
20
21	our $VERSION = '0.04';
22		4
23	=head1 SYNOPSIS	5	=head1 SYNOPSIS
24		6
25	use AnyEvent;	7	use AnyEvent;
26	use AnyEvent::Handle;	8	use AnyEvent::Handle;
27		9
28	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
29		11
30	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
31
32	#TODO
33
34	# or use the constructor to pass the callback:
35
36	my $ae_fh2 =
37	AnyEvent::Handle->new (
38	fh => \*STDIN,	13	fh => \*STDIN,
39	on_eof => sub {	14	on_error => sub {
40	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
41	},	16	warn "got error $msg\n";
42	#TODO	17	$hdl->destroy;
		18	$cv->send;
43	);	19	};
44		20
45	$cv->wait;	21	# send some request line
		22	$hdl->push_write ("getinfo\015\012");
		23
		24	# read the response line
		25	$hdl->push_read (line => sub {
		26	my ($hdl, $line) = @_;
		27	warn "got line <$line>\n";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
46		32
47	=head1 DESCRIPTION	33	=head1 DESCRIPTION
48		34
49	This module is a helper module to make it easier to do event-based I/O on	35	This is a helper module to make it easier to do event-based I/O on
50	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
51	on sockets see L<AnyEvent::Util>.
52		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
53	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
54	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
55	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
56		47
57	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
58	argument.	49	argument.
59		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
60	=head1 METHODS	82	=head1 METHODS
61		83
62	=over 4	84	=over 4
63		85
64	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
65		87
66	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
67		89
68	=over 4	90	=over 4
69		91
70	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
71		93
72	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
73
74	NOTE: The filehandle will be set to non-blocking (using	95	NOTE: The filehandle will be set to non-blocking mode (using
75	AnyEvent::Util::fh_nonblocking).	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
76		98
77	=item on_eof => $cb->($self)	99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
78		100
79	Set the callback to be called on EOF.	101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
80		104
81	While not mandatory, it is highly recommended to set an eof callback,	105	You have to specify either this parameter, or C<fh>, above.
82	otherwise you might end up with a closed socket while you are still
83	waiting for data.
84		106
		107	It is possible to push requests on the read and write queues, and modify
		108	properties of the stream, even while AnyEvent::Handle is connecting.
		109
		110	When this parameter is specified, then the C<on_prepare>,
		111	C<on_connect_error> and C<on_connect> callbacks will be called under the
		112	appropriate circumstances:
		113
		114	=over 4
		115
85	=item on_error => $cb->($self)	116	=item on_prepare => $cb->($handle)
86		117
		118	This (rarely used) callback is called before a new connection is
		119	attempted, but after the file handle has been created. It could be used to
		120	prepare the file handle with parameters required for the actual connect
		121	(as opposed to settings that can be changed when the connection is already
		122	established).
		123
		124	The return value of this callback should be the connect timeout value in
		125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
		126	default timeout is to be used).
		127
		128	=item on_connect => $cb->($handle, $host, $port, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback.
		134
		135	If, for some reason, the handle is not acceptable, calling C<$retry>
		136	will continue with the next connection target (in case of multi-homed
		137	hosts or SRV records there can be multiple connection endpoints). At the
		138	time it is called the read and write queues, eof status, tls status and
		139	similar properties of the handle will have been reset.
		140
		141	In most cases, you should ignore the C<$retry> parameter.
		142
		143	=item on_connect_error => $cb->($handle, $message)
		144
		145	This callback is called when the connection could not be
		146	established. C<$!> will contain the relevant error code, and C<$message> a
		147	message describing it (usually the same as C<"$!">).
		148
		149	If this callback isn't specified, then C<on_error> will be called with a
		150	fatal error instead.
		151
		152	=back
		153
		154	=item on_error => $cb->($handle, $fatal, $message)
		155
87	This is the fatal error callback, that is called when, well, a fatal error	156	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	157	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	158	connect, or a read error.
90		159
91	The object will not be in a usable state when this callback has been	160	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	called.	161	fatal errors the handle object will be destroyed (by a call to C<< ->
		162	destroy >>) after invoking the error callback (which means you are free to
		163	examine the handle object). Examples of fatal errors are an EOF condition
		164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
93		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
		173	Non-fatal errors can be retried by returning, but it is recommended
		174	to simply ignore this parameter and instead abondon the handle object
		175	when this callback is invoked. Examples of non-fatal errors are timeouts
		176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		177
94	On callback entrance, the value of C<$!> contains the operating system	178	On entry to the callback, the value of C<$!> contains the operating
95	error (or C<ENOSPC> or C<EPIPE>).	179	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		180	C<EPROTO>).
96		181
97	While not mandatory, it is I<highly> recommended to set this callback, as	182	While not mandatory, it is I<highly> recommended to set this callback, as
98	you will not be notified of errors otherwise. The default simply calls	183	you will not be notified of errors otherwise. The default just calls
99	die.	184	C<croak>.
100		185
101	=item on_read => $cb->($self)	186	=item on_read => $cb->($handle)
102		187
103	This sets the default read callback, which is called when data arrives	188	This sets the default read callback, which is called when data arrives
104	and no read request is in the queue.	189	and no read request is in the queue (unlike read queue callbacks, this
		190	callback will only be called when at least one octet of data is in the
		191	read buffer).
105		192
106	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	193	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107	method or acces sthe C<$self->{rbuf}> member directly.	194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
108		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
109	When an EOF condition is detected then AnyEvent::Handle will first try to	201	When an EOF condition is detected, AnyEvent::Handle will first try to
110	feed all the remaining data to the queued callbacks and C<on_read> before	202	feed all the remaining data to the queued callbacks and C<on_read> before
111	calling the C<on_eof> callback. If no progress can be made, then a fatal	203	calling the C<on_eof> callback. If no progress can be made, then a fatal
112	error will be raised (with C<$!> set to C<EPIPE>).	204	error will be raised (with C<$!> set to C<EPIPE>).
113		205
		206	Note that, unlike requests in the read queue, an C<on_read> callback
		207	doesn't mean you I<require> some data: if there is an EOF and there
		208	are outstanding read requests then an error will be flagged. With an
		209	C<on_read> callback, the C<on_eof> callback will be invoked.
		210
		211	=item on_eof => $cb->($handle)
		212
		213	Set the callback to be called when an end-of-file condition is detected,
		214	i.e. in the case of a socket, when the other side has closed the
		215	connection cleanly, and there are no outstanding read requests in the
		216	queue (if there are read requests, then an EOF counts as an unexpected
		217	connection close and will be flagged as an error).
		218
		219	For sockets, this just means that the other side has stopped sending data,
		220	you can still try to write data, and, in fact, one can return from the EOF
		221	callback and continue writing data, as only the read part has been shut
		222	down.
		223
		224	If an EOF condition has been detected but no C<on_eof> callback has been
		225	set, then a fatal error will be raised with C<$!> set to <0>.
		226
114	=item on_drain => $cb->()	227	=item on_drain => $cb->($handle)
115		228
116	This sets the callback that is called when the write buffer becomes empty	229	This sets the callback that is called when the write buffer becomes empty
117	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
118		231
119	To append to the write buffer, use the C<< ->push_write >> method.	232	To append to the write buffer, use the C<< ->push_write >> method.
		233
		234	This callback is useful when you don't want to put all of your write data
		235	into the queue at once, for example, when you want to write the contents
		236	of some file to the socket you might not want to read the whole file into
		237	memory and push it into the queue, but instead only read more data from
		238	the file when the write queue becomes empty.
		239
		240	=item timeout => $fractional_seconds
		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
		246	If non-zero, then these enables an "inactivity" timeout: whenever this
		247	many seconds pass without a successful read or write on the underlying
		248	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		249	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		250	error will be raised).
		251
		252	There are three variants of the timeouts that work independently
		253	of each other, for both read and write, just read, and just write:
		254	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		255	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		256	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		257
		258	Note that timeout processing is active even when you do not have
		259	any outstanding read or write requests: If you plan to keep the connection
		260	idle then you should disable the timeout temporarily or ignore the timeout
		261	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		262	restart the timeout.
		263
		264	Zero (the default) disables this timeout.
		265
		266	=item on_timeout => $cb->($handle)
		267
		268	Called whenever the inactivity timeout passes. If you return from this
		269	callback, then the timeout will be reset as if some activity had happened,
		270	so this condition is not fatal in any way.
120		271
121	=item rbuf_max => <bytes>	272	=item rbuf_max => <bytes>
122		273
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	274	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	275	when the read buffer ever (strictly) exceeds this size. This is useful to
125	avoid denial-of-service attacks.	276	avoid some forms of denial-of-service attacks.
126		277
127	For example, a server accepting connections from untrusted sources should	278	For example, a server accepting connections from untrusted sources should
128	be configured to accept only so-and-so much data that it cannot act on	279	be configured to accept only so-and-so much data that it cannot act on
129	(for example, when expecting a line, an attacker could send an unlimited	280	(for example, when expecting a line, an attacker could send an unlimited
130	amount of data without a callback ever being called as long as the line	281	amount of data without a callback ever being called as long as the line
131	isn't finished).	282	isn't finished).
132		283
		284	=item autocork => <boolean>
		285
		286	When disabled (the default), C<push_write> will try to immediately
		287	write the data to the handle if possible. This avoids having to register
		288	a write watcher and wait for the next event loop iteration, but can
		289	be inefficient if you write multiple small chunks (on the wire, this
		290	disadvantage is usually avoided by your kernel's nagle algorithm, see
		291	C<no_delay>, but this option can save costly syscalls).
		292
		293	When enabled, writes will always be queued till the next event loop
		294	iteration. This is efficient when you do many small writes per iteration,
		295	but less efficient when you do a single write only per iteration (or when
		296	the write buffer often is full). It also increases write latency.
		297
		298	=item no_delay => <boolean>
		299
		300	When doing small writes on sockets, your operating system kernel might
		301	wait a bit for more data before actually sending it out. This is called
		302	the Nagle algorithm, and usually it is beneficial.
		303
		304	In some situations you want as low a delay as possible, which can be
		305	accomplishd by setting this option to a true value.
		306
		307	The default is your operating system's default behaviour (most likely
		308	enabled). This option explicitly enables or disables it, if possible.
		309
		310	=item keepalive => <boolean>
		311
		312	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		313	normally, TCP connections have no time-out once established, so TCP
		314	connections, once established, can stay alive forever even when the other
		315	side has long gone. TCP keepalives are a cheap way to take down long-lived
		316	TCP connections when the other side becomes unreachable. While the default
		317	is OS-dependent, TCP keepalives usually kick in after around two hours,
		318	and, if the other side doesn't reply, take down the TCP connection some 10
		319	to 15 minutes later.
		320
		321	It is harmless to specify this option for file handles that do not support
		322	keepalives, and enabling it on connections that are potentially long-lived
		323	is usually a good idea.
		324
		325	=item oobinline => <boolean>
		326
		327	BSD majorly fucked up the implementation of TCP urgent data. The result
		328	is that almost no OS implements TCP according to the specs, and every OS
		329	implements it slightly differently.
		330
		331	If you want to handle TCP urgent data, then setting this flag (the default
		332	is enabled) gives you the most portable way of getting urgent data, by
		333	putting it into the stream.
		334
		335	Since BSD emulation of OOB data on top of TCP's urgent data can have
		336	security implications, AnyEvent::Handle sets this flag automatically
		337	unless explicitly specified. Note that setting this flag after
		338	establishing a connection I<may> be a bit too late (data loss could
		339	already have occured on BSD systems), but at least it will protect you
		340	from most attacks.
		341
133	=item read_size => <bytes>	342	=item read_size => <bytes>
134		343
135	The default read block size (the amount of bytes this module will try to read	344	The initial read block size, the number of bytes this module will try to
136	on each [loop iteration). Default: C<4096>.	345	read during each loop iteration. Each handle object will consume at least
		346	this amount of memory for the read buffer as well, so when handling many
		347	connections requirements). See also C<max_read_size>. Default: C<2048>.
		348
		349	=item max_read_size => <bytes>
		350
		351	The maximum read buffer size used by the dynamic adjustment
		352	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		353	one go it will double C<read_size> up to the maximum given by this
		354	option. Default: C<131072> or C<read_size>, whichever is higher.
137		355
138	=item low_water_mark => <bytes>	356	=item low_water_mark => <bytes>
139		357
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	358	Sets the number of bytes (default: C<0>) that make up an "empty" write
141	buffer: If the write reaches this size or gets even samller it is	359	buffer: If the buffer reaches this size or gets even samller it is
142	considered empty.	360	considered empty.
		361
		362	Sometimes it can be beneficial (for performance reasons) to add data to
		363	the write buffer before it is fully drained, but this is a rare case, as
		364	the operating system kernel usually buffers data as well, so the default
		365	is good in almost all cases.
		366
		367	=item linger => <seconds>
		368
		369	If this is non-zero (default: C<3600>), the destructor of the
		370	AnyEvent::Handle object will check whether there is still outstanding
		371	write data and will install a watcher that will write this data to the
		372	socket. No errors will be reported (this mostly matches how the operating
		373	system treats outstanding data at socket close time).
		374
		375	This will not work for partial TLS data that could not be encoded
		376	yet. This data will be lost. Calling the C<stoptls> method in time might
		377	help.
		378
		379	=item peername => $string
		380
		381	A string used to identify the remote site - usually the DNS hostname
		382	(I<not> IDN!) used to create the connection, rarely the IP address.
		383
		384	Apart from being useful in error messages, this string is also used in TLS
		385	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		386	verification will be skipped when C<peername> is not specified or is
		387	C<undef>.
		388
		389	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		390
		391	When this parameter is given, it enables TLS (SSL) mode, that means
		392	AnyEvent will start a TLS handshake as soon as the connection has been
		393	established and will transparently encrypt/decrypt data afterwards.
		394
		395	All TLS protocol errors will be signalled as C<EPROTO>, with an
		396	appropriate error message.
		397
		398	TLS mode requires Net::SSLeay to be installed (it will be loaded
		399	automatically when you try to create a TLS handle): this module doesn't
		400	have a dependency on that module, so if your module requires it, you have
		401	to add the dependency yourself.
		402
		403	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		404	C<accept>, and for the TLS client side of a connection, use C<connect>
		405	mode.
		406
		407	You can also provide your own TLS connection object, but you have
		408	to make sure that you call either C<Net::SSLeay::set_connect_state>
		409	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		410	AnyEvent::Handle. Also, this module will take ownership of this connection
		411	object.
		412
		413	At some future point, AnyEvent::Handle might switch to another TLS
		414	implementation, then the option to use your own session object will go
		415	away.
		416
		417	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		418	passing in the wrong integer will lead to certain crash. This most often
		419	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		420	segmentation fault.
		421
		422	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
		423
		424	=item tls_ctx => $anyevent_tls
		425
		426	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		427	(unless a connection object was specified directly). If this
		428	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		429	C<AnyEvent::Handle::TLS_CTX>.
		430
		431	Instead of an object, you can also specify a hash reference with C<< key
		432	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		433	new TLS context object.
		434
		435	=item on_starttls => $cb->($handle, $success[, $error_message])
		436
		437	This callback will be invoked when the TLS/SSL handshake has finished. If
		438	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		439	(C<on_stoptls> will not be called in this case).
		440
		441	The session in C<< $handle->{tls} >> can still be examined in this
		442	callback, even when the handshake was not successful.
		443
		444	TLS handshake failures will not cause C<on_error> to be invoked when this
		445	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		446
		447	Without this callback, handshake failures lead to C<on_error> being
		448	called as usual.
		449
		450	Note that you cannot just call C<starttls> again in this callback. If you
		451	need to do that, start an zero-second timer instead whose callback can
		452	then call C<< ->starttls >> again.
		453
		454	=item on_stoptls => $cb->($handle)
		455
		456	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		457	set, then it will be invoked after freeing the TLS session. If it is not,
		458	then a TLS shutdown condition will be treated like a normal EOF condition
		459	on the handle.
		460
		461	The session in C<< $handle->{tls} >> can still be examined in this
		462	callback.
		463
		464	This callback will only be called on TLS shutdowns, not when the
		465	underlying handle signals EOF.
		466
		467	=item json => JSON or JSON::XS object
		468
		469	This is the json coder object used by the C<json> read and write types.
		470
		471	If you don't supply it, then AnyEvent::Handle will create and use a
		472	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		473	texts.
		474
		475	Note that you are responsible to depend on the JSON module if you want to
		476	use this functionality, as AnyEvent does not have a dependency itself.
143		477
144	=back	478	=back
145		479
146	=cut	480	=cut
147		481
148	sub new {	482	sub new {
149	my $class = shift;	483	my $class = shift;
150
151	my $self = bless { @_ }, $class;	484	my $self = bless { @_ }, $class;
152		485
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	486	if ($self->{fh}) {
		487	$self->_start;
		488	return unless $self->{fh}; # could be gone by now
		489
		490	} elsif ($self->{connect}) {
		491	require AnyEvent::Socket;
		492
		493	$self->{peername} = $self->{connect}[0]
		494	unless exists $self->{peername};
		495
		496	$self->{_skip_drain_rbuf} = 1;
		497
		498	{
		499	Scalar::Util::weaken (my $self = $self);
		500
		501	$self->{_connect} =
		502	AnyEvent::Socket::tcp_connect (
		503	$self->{connect}[0],
		504	$self->{connect}[1],
		505	sub {
		506	my ($fh, $host, $port, $retry) = @_;
		507
		508	delete $self->{_connect}; # no longer needed
		509
		510	if ($fh) {
		511	$self->{fh} = $fh;
		512
		513	delete $self->{_skip_drain_rbuf};
		514	$self->_start;
		515
		516	$self->{on_connect}
		517	and $self->{on_connect}($self, $host, $port, sub {
		518	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		519	$self->{_skip_drain_rbuf} = 1;
		520	&$retry;
		521	});
		522
		523	} else {
		524	if ($self->{on_connect_error}) {
		525	$self->{on_connect_error}($self, "$!");
		526	$self->destroy;
		527	} else {
		528	$self->_error ($!, 1);
		529	}
		530	}
		531	},
		532	sub {
		533	local $self->{fh} = $_[0];
		534
		535	$self->{on_prepare}
		536	? $self->{on_prepare}->($self)
		537	: ()
		538	}
		539	);
		540	}
		541
		542	} else {
		543	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		544	}
		545
		546	$self
		547	}
		548
		549	sub _start {
		550	my ($self) = @_;
		551
		552	# too many clueless people try to use udp and similar sockets
		553	# with AnyEvent::Handle, do them a favour.
		554	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		555	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		556	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
154		557
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	558	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		559
		560	$self->{_activity} =
		561	$self->{_ractivity} =
		562	$self->{_wactivity} = AE::now;
		563
		564	$self->{read_size} ||= 2048;
		565	$self->{max_read_size} = $self->{read_size}
		566	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		567
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	568	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	569	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		570	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		571
		572	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		573	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		574
		575	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		576
		577	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		578	if $self->{tls};
		579
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	580	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
161		581
162	$self->start_read;	582	$self->start_read
		583	if $self->{on_read} || @{ $self->{_queue} };
163		584
164	$self	585	$self->_drain_wbuf;
165	}	586	}
166		587
167	sub _shutdown {
168	my ($self) = @_;
169
170	delete $self->{rw};
171	delete $self->{ww};
172	delete $self->{fh};
173	}
174
175	sub error {	588	sub _error {
176	my ($self) = @_;	589	my ($self, $errno, $fatal, $message) = @_;
177		590
178	{	591	$! = $errno;
179	local $!;	592	$message ||= "$!";
180	$self->_shutdown;
181	}
182		593
183	if ($self->{on_error}) {	594	if ($self->{on_error}) {
184	$self->{on_error}($self);	595	$self->{on_error}($self, $fatal, $message);
185	} else {	596	$self->destroy if $fatal;
		597	} elsif ($self->{fh} || $self->{connect}) {
		598	$self->destroy;
186	die "AnyEvent::Handle uncaught fatal error: $!";	599	Carp::croak "AnyEvent::Handle uncaught error: $message";
187	}	600	}
188	}	601	}
189		602
190	=item $fh = $handle->fh	603	=item $fh = $handle->fh
191		604
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	605	This method returns the file handle used to create the L<AnyEvent::Handle> object.
193		606
194	=cut	607	=cut
195		608
196	sub fh { $_[0]->{fh} }	609	sub fh { $_[0]{fh} }
197		610
198	=item $handle->on_error ($cb)	611	=item $handle->on_error ($cb)
199		612
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	613	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		614
…		…
213		626
214	sub on_eof {	627	sub on_eof {
215	$_[0]{on_eof} = $_[1];	628	$_[0]{on_eof} = $_[1];
216	}	629	}
217		630
		631	=item $handle->on_timeout ($cb)
		632
		633	=item $handle->on_rtimeout ($cb)
		634
		635	=item $handle->on_wtimeout ($cb)
		636
		637	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		638	callback, or disables the callback (but not the timeout) if C<$cb> =
		639	C<undef>. See the C<timeout> constructor argument and method.
		640
		641	=cut
		642
		643	# see below
		644
		645	=item $handle->autocork ($boolean)
		646
		647	Enables or disables the current autocork behaviour (see C<autocork>
		648	constructor argument). Changes will only take effect on the next write.
		649
		650	=cut
		651
		652	sub autocork {
		653	$_[0]{autocork} = $_[1];
		654	}
		655
		656	=item $handle->no_delay ($boolean)
		657
		658	Enables or disables the C<no_delay> setting (see constructor argument of
		659	the same name for details).
		660
		661	=cut
		662
		663	sub no_delay {
		664	$_[0]{no_delay} = $_[1];
		665
		666	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		667	if $_[0]{fh};
		668	}
		669
		670	=item $handle->keepalive ($boolean)
		671
		672	Enables or disables the C<keepalive> setting (see constructor argument of
		673	the same name for details).
		674
		675	=cut
		676
		677	sub keepalive {
		678	$_[0]{keepalive} = $_[1];
		679
		680	eval {
		681	local $SIG{__DIE__};
		682	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		683	if $_[0]{fh};
		684	};
		685	}
		686
		687	=item $handle->oobinline ($boolean)
		688
		689	Enables or disables the C<oobinline> setting (see constructor argument of
		690	the same name for details).
		691
		692	=cut
		693
		694	sub oobinline {
		695	$_[0]{oobinline} = $_[1];
		696
		697	eval {
		698	local $SIG{__DIE__};
		699	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		700	if $_[0]{fh};
		701	};
		702	}
		703
		704	=item $handle->keepalive ($boolean)
		705
		706	Enables or disables the C<keepalive> setting (see constructor argument of
		707	the same name for details).
		708
		709	=cut
		710
		711	sub keepalive {
		712	$_[0]{keepalive} = $_[1];
		713
		714	eval {
		715	local $SIG{__DIE__};
		716	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		717	if $_[0]{fh};
		718	};
		719	}
		720
		721	=item $handle->on_starttls ($cb)
		722
		723	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		724
		725	=cut
		726
		727	sub on_starttls {
		728	$_[0]{on_starttls} = $_[1];
		729	}
		730
		731	=item $handle->on_stoptls ($cb)
		732
		733	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		734
		735	=cut
		736
		737	sub on_stoptls {
		738	$_[0]{on_stoptls} = $_[1];
		739	}
		740
		741	=item $handle->rbuf_max ($max_octets)
		742
		743	Configures the C<rbuf_max> setting (C<undef> disables it).
		744
		745	=cut
		746
		747	sub rbuf_max {
		748	$_[0]{rbuf_max} = $_[1];
		749	}
		750
		751	#############################################################################
		752
		753	=item $handle->timeout ($seconds)
		754
		755	=item $handle->rtimeout ($seconds)
		756
		757	=item $handle->wtimeout ($seconds)
		758
		759	Configures (or disables) the inactivity timeout.
		760
		761	=item $handle->timeout_reset
		762
		763	=item $handle->rtimeout_reset
		764
		765	=item $handle->wtimeout_reset
		766
		767	Reset the activity timeout, as if data was received or sent.
		768
		769	These methods are cheap to call.
		770
		771	=cut
		772
		773	for my $dir ("", "r", "w") {
		774	my $timeout = "${dir}timeout";
		775	my $tw = "_${dir}tw";
		776	my $on_timeout = "on_${dir}timeout";
		777	my $activity = "_${dir}activity";
		778	my $cb;
		779
		780	*$on_timeout = sub {
		781	$_[0]{$on_timeout} = $_[1];
		782	};
		783
		784	*$timeout = sub {
		785	my ($self, $new_value) = @_;
		786
		787	$new_value >= 0
		788	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		789
		790	$self->{$timeout} = $new_value;
		791	delete $self->{$tw}; &$cb;
		792	};
		793
		794	*{"${dir}timeout_reset"} = sub {
		795	$_[0]{$activity} = AE::now;
		796	};
		797
		798	# main workhorse:
		799	# reset the timeout watcher, as neccessary
		800	# also check for time-outs
		801	$cb = sub {
		802	my ($self) = @_;
		803
		804	if ($self->{$timeout} && $self->{fh}) {
		805	my $NOW = AE::now;
		806
		807	# when would the timeout trigger?
		808	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		809
		810	# now or in the past already?
		811	if ($after <= 0) {
		812	$self->{$activity} = $NOW;
		813
		814	if ($self->{$on_timeout}) {
		815	$self->{$on_timeout}($self);
		816	} else {
		817	$self->_error (Errno::ETIMEDOUT);
		818	}
		819
		820	# callback could have changed timeout value, optimise
		821	return unless $self->{$timeout};
		822
		823	# calculate new after
		824	$after = $self->{$timeout};
		825	}
		826
		827	Scalar::Util::weaken $self;
		828	return unless $self; # ->error could have destroyed $self
		829
		830	$self->{$tw} ||= AE::timer $after, 0, sub {
		831	delete $self->{$tw};
		832	$cb->($self);
		833	};
		834	} else {
		835	delete $self->{$tw};
		836	}
		837	}
		838	}
		839
218	#############################################################################	840	#############################################################################
219		841
220	=back	842	=back
221		843
222	=head2 WRITE QUEUE	844	=head2 WRITE QUEUE
…		…
225	for reading.	847	for reading.
226		848
227	The write queue is very simple: you can add data to its end, and	849	The write queue is very simple: you can add data to its end, and
228	AnyEvent::Handle will automatically try to get rid of it for you.	850	AnyEvent::Handle will automatically try to get rid of it for you.
229		851
230	When data could be writtena nd the write buffer is shorter then the low	852	When data could be written and the write buffer is shorter then the low
231	water mark, the C<on_drain> callback will be invoked.	853	water mark, the C<on_drain> callback will be invoked.
232		854
233	=over 4	855	=over 4
234		856
235	=item $handle->on_drain ($cb)	857	=item $handle->on_drain ($cb)
236		858
237	Sets the C<on_drain> callback or clears it (see the description of	859	Sets the C<on_drain> callback or clears it (see the description of
238	C<on_drain> in the constructor).	860	C<on_drain> in the constructor).
239		861
		862	This method may invoke callbacks (and therefore the handle might be
		863	destroyed after it returns).
		864
240	=cut	865	=cut
241		866
242	sub on_drain {	867	sub on_drain {
243	my ($self, $cb) = @_;	868	my ($self, $cb) = @_;
244		869
245	$self->{on_drain} = $cb;	870	$self->{on_drain} = $cb;
246		871
247	$cb->($self)	872	$cb->($self)
248	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	873	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
249	}	874	}
250		875
251	=item $handle->push_write ($data)	876	=item $handle->push_write ($data)
252		877
253	Queues the given scalar to be written. You can push as much data as you	878	Queues the given scalar to be written. You can push as much data as you
254	want (only limited by the available memory), as C<AnyEvent::Handle>	879	want (only limited by the available memory), as C<AnyEvent::Handle>
255	buffers it independently of the kernel.	880	buffers it independently of the kernel.
256		881
		882	This method may invoke callbacks (and therefore the handle might be
		883	destroyed after it returns).
		884
257	=cut	885	=cut
258		886
259	sub _drain_wbuf {	887	sub _drain_wbuf {
260	my ($self) = @_;	888	my ($self) = @_;
261		889
262	unless ($self->{ww}) {	890	if (!$self->{_ww} && length $self->{wbuf}) {
		891
263	Scalar::Util::weaken $self;	892	Scalar::Util::weaken $self;
		893
264	my $cb = sub {	894	my $cb = sub {
265	my $len = syswrite $self->{fh}, $self->{wbuf};	895	my $len = syswrite $self->{fh}, $self->{wbuf};
266		896
267	if ($len > 0) {	897	if (defined $len) {
268	substr $self->{wbuf}, 0, $len, "";	898	substr $self->{wbuf}, 0, $len, "";
269		899
		900	$self->{_activity} = $self->{_wactivity} = AE::now;
		901
270	$self->{on_drain}($self)	902	$self->{on_drain}($self)
271	if $self->{low_water_mark} >= length $self->{wbuf}	903	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
272	&& $self->{on_drain};	904	&& $self->{on_drain};
273		905
274	delete $self->{ww} unless length $self->{wbuf};	906	delete $self->{_ww} unless length $self->{wbuf};
275	} elsif ($! != EAGAIN && $! != EINTR) {	907	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
276	$self->error;	908	$self->_error ($!, 1);
277	}	909	}
278	};	910	};
279		911
280	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	912	# try to write data immediately
		913	$cb->() unless $self->{autocork};
281		914
282	$cb->($self);	915	# if still data left in wbuf, we need to poll
		916	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		917	if length $self->{wbuf};
283	};	918	};
		919	}
		920
		921	our %WH;
		922
		923	# deprecated
		924	sub register_write_type($$) {
		925	$WH{$_[0]} = $_[1];
284	}	926	}
285		927
286	sub push_write {	928	sub push_write {
287	my $self = shift;	929	my $self = shift;
288		930
		931	if (@_ > 1) {
		932	my $type = shift;
		933
		934	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		935	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		936	->($self, @_);
		937	}
		938
		939	# we downgrade here to avoid hard-to-track-down bugs,
		940	# and diagnose the problem earlier and better.
		941
289	if ($self->{filter_w}) {	942	if ($self->{tls}) {
290	$self->{filter_w}->(\$_[0]);	943	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		944	&_dotls ($self) if $self->{fh};
291	} else {	945	} else {
292	$self->{wbuf} .= $_[0];	946	utf8::downgrade $self->{wbuf} .= $_[0];
293	$self->_drain_wbuf;	947	$self->_drain_wbuf if $self->{fh};
294	}	948	}
295	}	949	}
		950
		951	=item $handle->push_write (type => @args)
		952
		953	Instead of formatting your data yourself, you can also let this module
		954	do the job by specifying a type and type-specific arguments. You
		955	can also specify the (fully qualified) name of a package, in which
		956	case AnyEvent tries to load the package and then expects to find the
		957	C<anyevent_write_type> function inside (see "custom write types", below).
		958
		959	Predefined types are (if you have ideas for additional types, feel free to
		960	drop by and tell us):
		961
		962	=over 4
		963
		964	=item netstring => $string
		965
		966	Formats the given value as netstring
		967	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		968
		969	=cut
		970
		971	register_write_type netstring => sub {
		972	my ($self, $string) = @_;
		973
		974	(length $string) . ":$string,"
		975	};
		976
		977	=item packstring => $format, $data
		978
		979	An octet string prefixed with an encoded length. The encoding C<$format>
		980	uses the same format as a Perl C<pack> format, but must specify a single
		981	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		982	optional C<!>, C<< < >> or C<< > >> modifier).
		983
		984	=cut
		985
		986	register_write_type packstring => sub {
		987	my ($self, $format, $string) = @_;
		988
		989	pack "$format/a*", $string
		990	};
		991
		992	=item json => $array_or_hashref
		993
		994	Encodes the given hash or array reference into a JSON object. Unless you
		995	provide your own JSON object, this means it will be encoded to JSON text
		996	in UTF-8.
		997
		998	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		999	one end of a handle and read them at the other end without using any
		1000	additional framing.
		1001
		1002	The generated JSON text is guaranteed not to contain any newlines: While
		1003	this module doesn't need delimiters after or between JSON texts to be
		1004	able to read them, many other languages depend on that.
		1005
		1006	A simple RPC protocol that interoperates easily with others is to send
		1007	JSON arrays (or objects, although arrays are usually the better choice as
		1008	they mimic how function argument passing works) and a newline after each
		1009	JSON text:
		1010
		1011	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1012	$handle->push_write ("\012");
		1013
		1014	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1015	rely on the fact that the newline will be skipped as leading whitespace:
		1016
		1017	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1018
		1019	Other languages could read single lines terminated by a newline and pass
		1020	this line into their JSON decoder of choice.
		1021
		1022	=cut
		1023
		1024	sub json_coder() {
		1025	eval { require JSON::XS; JSON::XS->new->utf8 }
		1026	|| do { require JSON; JSON->new->utf8 }
		1027	}
		1028
		1029	register_write_type json => sub {
		1030	my ($self, $ref) = @_;
		1031
		1032	my $json = $self->{json} ||= json_coder;
		1033
		1034	$json->encode ($ref)
		1035	};
		1036
		1037	=item storable => $reference
		1038
		1039	Freezes the given reference using L<Storable> and writes it to the
		1040	handle. Uses the C<nfreeze> format.
		1041
		1042	=cut
		1043
		1044	register_write_type storable => sub {
		1045	my ($self, $ref) = @_;
		1046
		1047	require Storable;
		1048
		1049	pack "w/a*", Storable::nfreeze ($ref)
		1050	};
		1051
		1052	=back
		1053
		1054	=item $handle->push_shutdown
		1055
		1056	Sometimes you know you want to close the socket after writing your data
		1057	before it was actually written. One way to do that is to replace your
		1058	C<on_drain> handler by a callback that shuts down the socket (and set
		1059	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1060	replaces the C<on_drain> callback with:
		1061
		1062	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1063
		1064	This simply shuts down the write side and signals an EOF condition to the
		1065	the peer.
		1066
		1067	You can rely on the normal read queue and C<on_eof> handling
		1068	afterwards. This is the cleanest way to close a connection.
		1069
		1070	This method may invoke callbacks (and therefore the handle might be
		1071	destroyed after it returns).
		1072
		1073	=cut
		1074
		1075	sub push_shutdown {
		1076	my ($self) = @_;
		1077
		1078	delete $self->{low_water_mark};
		1079	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1080	}
		1081
		1082	=item custom write types - Package::anyevent_write_type $handle, @args
		1083
		1084	Instead of one of the predefined types, you can also specify the name of
		1085	a package. AnyEvent will try to load the package and then expects to find
		1086	a function named C<anyevent_write_type> inside. If it isn't found, it
		1087	progressively tries to load the parent package until it either finds the
		1088	function (good) or runs out of packages (bad).
		1089
		1090	Whenever the given C<type> is used, C<push_write> will the function with
		1091	the handle object and the remaining arguments.
		1092
		1093	The function is supposed to return a single octet string that will be
		1094	appended to the write buffer, so you cna mentally treat this function as a
		1095	"arguments to on-the-wire-format" converter.
		1096
		1097	Example: implement a custom write type C<join> that joins the remaining
		1098	arguments using the first one.
		1099
		1100	$handle->push_write (My::Type => " ", 1,2,3);
		1101
		1102	# uses the following package, which can be defined in the "My::Type" or in
		1103	# the "My" modules to be auto-loaded, or just about anywhere when the
		1104	# My::Type::anyevent_write_type is defined before invoking it.
		1105
		1106	package My::Type;
		1107
		1108	sub anyevent_write_type {
		1109	my ($handle, $delim, @args) = @_;
		1110
		1111	join $delim, @args
		1112	}
		1113
		1114	=cut
296		1115
297	#############################################################################	1116	#############################################################################
298		1117
299	=back	1118	=back
300		1119
…		…
307	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1126	ways, the "simple" way, using only C<on_read> and the "complex" way, using
308	a queue.	1127	a queue.
309		1128
310	In the simple case, you just install an C<on_read> callback and whenever	1129	In the simple case, you just install an C<on_read> callback and whenever
311	new data arrives, it will be called. You can then remove some data (if	1130	new data arrives, it will be called. You can then remove some data (if
312	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	1131	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
313	or not.	1132	leave the data there if you want to accumulate more (e.g. when only a
		1133	partial message has been received so far), or change the read queue with
		1134	e.g. C<push_read>.
314		1135
315	In the more complex case, you want to queue multiple callbacks. In this	1136	In the more complex case, you want to queue multiple callbacks. In this
316	case, AnyEvent::Handle will call the first queued callback each time new	1137	case, AnyEvent::Handle will call the first queued callback each time new
317	data arrives and removes it when it has done its job (see C<push_read>,	1138	data arrives (also the first time it is queued) and remove it when it has
318	below).	1139	done its job (see C<push_read>, below).
319		1140
320	This way you can, for example, push three line-reads, followed by reading	1141	This way you can, for example, push three line-reads, followed by reading
321	a chunk of data, and AnyEvent::Handle will execute them in order.	1142	a chunk of data, and AnyEvent::Handle will execute them in order.
322		1143
323	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1144	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
324	the specified number of bytes which give an XML datagram.	1145	the specified number of bytes which give an XML datagram.
325		1146
326	# in the default state, expect some header bytes	1147	# in the default state, expect some header bytes
327	$handle->on_read (sub {	1148	$handle->on_read (sub {
328	# some data is here, now queue the length-header-read (4 octets)	1149	# some data is here, now queue the length-header-read (4 octets)
329	shift->unshift_read_chunk (4, sub {	1150	shift->unshift_read (chunk => 4, sub {
330	# header arrived, decode	1151	# header arrived, decode
331	my $len = unpack "N", $_[1];	1152	my $len = unpack "N", $_[1];
332		1153
333	# now read the payload	1154	# now read the payload
334	shift->unshift_read_chunk ($len, sub {	1155	shift->unshift_read (chunk => $len, sub {
335	my $xml = $_[1];	1156	my $xml = $_[1];
336	# handle xml	1157	# handle xml
337	});	1158	});
338	});	1159	});
339	});	1160	});
340		1161
341	Example 2: Implement a client for a protocol that replies either with	1162	Example 2: Implement a client for a protocol that replies either with "OK"
342	"OK" and another line or "ERROR" for one request, and 64 bytes for the	1163	and another line or "ERROR" for the first request that is sent, and 64
343	second request. Due tot he availability of a full queue, we can just	1164	bytes for the second request. Due to the availability of a queue, we can
344	pipeline sending both requests and manipulate the queue as necessary in	1165	just pipeline sending both requests and manipulate the queue as necessary
345	the callbacks:	1166	in the callbacks.
346		1167
347	# request one	1168	When the first callback is called and sees an "OK" response, it will
		1169	C<unshift> another line-read. This line-read will be queued I<before> the
		1170	64-byte chunk callback.
		1171
		1172	# request one, returns either "OK + extra line" or "ERROR"
348	$handle->push_write ("request 1\015\012");	1173	$handle->push_write ("request 1\015\012");
349		1174
350	# we expect "ERROR" or "OK" as response, so push a line read	1175	# we expect "ERROR" or "OK" as response, so push a line read
351	$handle->push_read_line (sub {	1176	$handle->push_read (line => sub {
352	# if we got an "OK", we have to _prepend_ another line,	1177	# if we got an "OK", we have to _prepend_ another line,
353	# so it will be read before the second request reads its 64 bytes	1178	# so it will be read before the second request reads its 64 bytes
354	# which are already in the queue when this callback is called	1179	# which are already in the queue when this callback is called
355	# we don't do this in case we got an error	1180	# we don't do this in case we got an error
356	if ($_[1] eq "OK") {	1181	if ($_[1] eq "OK") {
357	$_[0]->unshift_read_line (sub {	1182	$_[0]->unshift_read (line => sub {
358	my $response = $_[1];	1183	my $response = $_[1];
359	...	1184	...
360	});	1185	});
361	}	1186	}
362	});	1187	});
363		1188
364	# request two	1189	# request two, simply returns 64 octets
365	$handle->push_write ("request 2\015\012");	1190	$handle->push_write ("request 2\015\012");
366		1191
367	# simply read 64 bytes, always	1192	# simply read 64 bytes, always
368	$handle->push_read_chunk (64, sub {	1193	$handle->push_read (chunk => 64, sub {
369	my $response = $_[1];	1194	my $response = $_[1];
370	...	1195	...
371	});	1196	});
372		1197
373	=over 4	1198	=over 4
374		1199
375	=cut	1200	=cut
376		1201
377	sub _drain_rbuf {	1202	sub _drain_rbuf {
378	my ($self) = @_;	1203	my ($self) = @_;
		1204
		1205	# avoid recursion
		1206	return if $self->{_skip_drain_rbuf};
		1207	local $self->{_skip_drain_rbuf} = 1;
		1208
		1209	while () {
		1210	# we need to use a separate tls read buffer, as we must not receive data while
		1211	# we are draining the buffer, and this can only happen with TLS.
		1212	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1213	if exists $self->{_tls_rbuf};
		1214
		1215	my $len = length $self->{rbuf};
		1216
		1217	if (my $cb = shift @{ $self->{_queue} }) {
		1218	unless ($cb->($self)) {
		1219	# no progress can be made
		1220	# (not enough data and no data forthcoming)
		1221	$self->_error (Errno::EPIPE, 1), return
		1222	if $self->{_eof};
		1223
		1224	unshift @{ $self->{_queue} }, $cb;
		1225	last;
		1226	}
		1227	} elsif ($self->{on_read}) {
		1228	last unless $len;
		1229
		1230	$self->{on_read}($self);
		1231
		1232	if (
		1233	$len == length $self->{rbuf} # if no data has been consumed
		1234	&& !@{ $self->{_queue} } # and the queue is still empty
		1235	&& $self->{on_read} # but we still have on_read
		1236	) {
		1237	# no further data will arrive
		1238	# so no progress can be made
		1239	$self->_error (Errno::EPIPE, 1), return
		1240	if $self->{_eof};
		1241
		1242	last; # more data might arrive
		1243	}
		1244	} else {
		1245	# read side becomes idle
		1246	delete $self->{_rw} unless $self->{tls};
		1247	last;
		1248	}
		1249	}
		1250
		1251	if ($self->{_eof}) {
		1252	$self->{on_eof}
		1253	? $self->{on_eof}($self)
		1254	: $self->_error (0, 1, "Unexpected end-of-file");
		1255
		1256	return;
		1257	}
379		1258
380	if (	1259	if (
381	defined $self->{rbuf_max}	1260	defined $self->{rbuf_max}
382	&& $self->{rbuf_max} < length $self->{rbuf}	1261	&& $self->{rbuf_max} < length $self->{rbuf}
383	) {	1262	) {
384	$! = &Errno::ENOSPC; return $self->error;	1263	$self->_error (Errno::ENOSPC, 1), return;
385	}	1264	}
386		1265
387	return if $self->{in_drain};	1266	# may need to restart read watcher
388	local $self->{in_drain} = 1;	1267	unless ($self->{_rw}) {
389		1268	$self->start_read
390	while (my $len = length $self->{rbuf}) {	1269	if $self->{on_read} || @{ $self->{_queue} };
391	no strict 'refs';
392	if (my $cb = shift @{ $self->{queue} }) {
393	if (!$cb->($self)) {
394	if ($self->{eof}) {
395	# no progress can be made (not enough data and no data forthcoming)
396	$! = &Errno::EPIPE; return $self->error;
397	}
398
399	unshift @{ $self->{queue} }, $cb;
400	return;
401	}
402	} elsif ($self->{on_read}) {
403	$self->{on_read}($self);
404
405	if (
406	$self->{eof} # if no further data will arrive
407	&& $len == length $self->{rbuf} # and no data has been consumed
408	&& !@{ $self->{queue} } # and the queue is still empty
409	&& $self->{on_read} # and we still want to read data
410	) {
411	# then no progress can be made
412	$! = &Errno::EPIPE; return $self->error;
413	}
414	} else {
415	# read side becomes idle
416	delete $self->{rw};
417	return;
418	}
419	}
420
421	if ($self->{eof}) {
422	$self->_shutdown;
423	$self->{on_eof}($self)
424	if $self->{on_eof};
425	}	1270	}
426	}	1271	}
427		1272
428	=item $handle->on_read ($cb)	1273	=item $handle->on_read ($cb)
429		1274
430	This replaces the currently set C<on_read> callback, or clears it (when	1275	This replaces the currently set C<on_read> callback, or clears it (when
431	the new callback is C<undef>). See the description of C<on_read> in the	1276	the new callback is C<undef>). See the description of C<on_read> in the
432	constructor.	1277	constructor.
433		1278
		1279	This method may invoke callbacks (and therefore the handle might be
		1280	destroyed after it returns).
		1281
434	=cut	1282	=cut
435		1283
436	sub on_read {	1284	sub on_read {
437	my ($self, $cb) = @_;	1285	my ($self, $cb) = @_;
438		1286
439	$self->{on_read} = $cb;	1287	$self->{on_read} = $cb;
		1288	$self->_drain_rbuf if $cb;
440	}	1289	}
441		1290
442	=item $handle->rbuf	1291	=item $handle->rbuf
443		1292
444	Returns the read buffer (as a modifiable lvalue).	1293	Returns the read buffer (as a modifiable lvalue). You can also access the
		1294	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1295	much faster, and no less clean).
445		1296
446	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1297	The only operation allowed on the read buffer (apart from looking at it)
447	you want.	1298	is removing data from its beginning. Otherwise modifying or appending to
		1299	it is not allowed and will lead to hard-to-track-down bugs.
448		1300
449	NOTE: The read buffer should only be used or modified if the C<on_read>,	1301	NOTE: The read buffer should only be used or modified in the C<on_read>
450	C<push_read> or C<unshift_read> methods are used. The other read methods	1302	callback or when C<push_read> or C<unshift_read> are used with a single
451	automatically manage the read buffer.	1303	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1304	will manage the read buffer on their own.
452		1305
453	=cut	1306	=cut
454		1307
455	sub rbuf : lvalue {	1308	sub rbuf : lvalue {
456	$_[0]{rbuf}	1309	$_[0]{rbuf}
…		…
463	Append the given callback to the end of the queue (C<push_read>) or	1316	Append the given callback to the end of the queue (C<push_read>) or
464	prepend it (C<unshift_read>).	1317	prepend it (C<unshift_read>).
465		1318
466	The callback is called each time some additional read data arrives.	1319	The callback is called each time some additional read data arrives.
467		1320
468	It must check wether enough data is in the read buffer already.	1321	It must check whether enough data is in the read buffer already.
469		1322
470	If not enough data is available, it must return the empty list or a false	1323	If not enough data is available, it must return the empty list or a false
471	value, in which case it will be called repeatedly until enough data is	1324	value, in which case it will be called repeatedly until enough data is
472	available (or an error condition is detected).	1325	available (or an error condition is detected).
473		1326
474	If enough data was available, then the callback must remove all data it is	1327	If enough data was available, then the callback must remove all data it is
475	interested in (which can be none at all) and return a true value. After returning	1328	interested in (which can be none at all) and return a true value. After returning
476	true, it will be removed from the queue.	1329	true, it will be removed from the queue.
477		1330
		1331	These methods may invoke callbacks (and therefore the handle might be
		1332	destroyed after it returns).
		1333
478	=cut	1334	=cut
		1335
		1336	our %RH;
		1337
		1338	sub register_read_type($$) {
		1339	$RH{$_[0]} = $_[1];
		1340	}
479		1341
480	sub push_read {	1342	sub push_read {
481	my ($self, $cb) = @_;	1343	my $self = shift;
		1344	my $cb = pop;
482		1345
		1346	if (@_) {
		1347	my $type = shift;
		1348
		1349	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1350	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1351	->($self, $cb, @_);
		1352	}
		1353
483	push @{ $self->{queue} }, $cb;	1354	push @{ $self->{_queue} }, $cb;
484	$self->_drain_rbuf;	1355	$self->_drain_rbuf;
485	}	1356	}
486		1357
487	sub unshift_read {	1358	sub unshift_read {
488	my ($self, $cb) = @_;	1359	my $self = shift;
		1360	my $cb = pop;
489		1361
		1362	if (@_) {
		1363	my $type = shift;
		1364
		1365	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1366	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
		1367	->($self, $cb, @_);
		1368	}
		1369
490	push @{ $self->{queue} }, $cb;	1370	unshift @{ $self->{_queue} }, $cb;
491	$self->_drain_rbuf;	1371	$self->_drain_rbuf;
492	}	1372	}
493		1373
494	=item $handle->push_read_chunk ($len, $cb->($self, $data))	1374	=item $handle->push_read (type => @args, $cb)
495		1375
496	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	1376	=item $handle->unshift_read (type => @args, $cb)
497		1377
498	Append the given callback to the end of the queue (C<push_read_chunk>) or	1378	Instead of providing a callback that parses the data itself you can chose
499	prepend it (C<unshift_read_chunk>).	1379	between a number of predefined parsing formats, for chunks of data, lines
		1380	etc. You can also specify the (fully qualified) name of a package, in
		1381	which case AnyEvent tries to load the package and then expects to find the
		1382	C<anyevent_read_type> function inside (see "custom read types", below).
500		1383
501	The callback will be called only once C<$len> bytes have been read, and	1384	Predefined types are (if you have ideas for additional types, feel free to
502	these C<$len> bytes will be passed to the callback.	1385	drop by and tell us):
503		1386
504	=cut	1387	=over 4
505		1388
506	sub _read_chunk($$) {	1389	=item chunk => $octets, $cb->($handle, $data)
		1390
		1391	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1392	data read to the callback. The callback will never be called with less
		1393	data.
		1394
		1395	Example: read 2 bytes.
		1396
		1397	$handle->push_read (chunk => 2, sub {
		1398	warn "yay ", unpack "H*", $_[1];
		1399	});
		1400
		1401	=cut
		1402
		1403	register_read_type chunk => sub {
507	my ($self, $len, $cb) = @_;	1404	my ($self, $cb, $len) = @_;
508		1405
509	sub {	1406	sub {
510	$len <= length $_[0]{rbuf} or return;	1407	$len <= length $_[0]{rbuf} or return;
511	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1408	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
512	1	1409	1
513	}	1410	}
514	}	1411	};
515		1412
516	sub push_read_chunk {	1413	=item line => [$eol, ]$cb->($handle, $line, $eol)
517	$_[0]->push_read (&_read_chunk);
518	}
519
520
521	sub unshift_read_chunk {
522	$_[0]->unshift_read (&_read_chunk);
523	}
524
525	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
526
527	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
528
529	Append the given callback to the end of the queue (C<push_read_line>) or
530	prepend it (C<unshift_read_line>).
531		1414
532	The callback will be called only once a full line (including the end of	1415	The callback will be called only once a full line (including the end of
533	line marker, C<$eol>) has been read. This line (excluding the end of line	1416	line marker, C<$eol>) has been read. This line (excluding the end of line
534	marker) will be passed to the callback as second argument (C<$line>), and	1417	marker) will be passed to the callback as second argument (C<$line>), and
535	the end of line marker as the third argument (C<$eol>).	1418	the end of line marker as the third argument (C<$eol>).
…		…
546	Partial lines at the end of the stream will never be returned, as they are	1429	Partial lines at the end of the stream will never be returned, as they are
547	not marked by the end of line marker.	1430	not marked by the end of line marker.
548		1431
549	=cut	1432	=cut
550		1433
551	sub _read_line($$) {	1434	register_read_type line => sub {
552	my $self = shift;	1435	my ($self, $cb, $eol) = @_;
553	my $cb = pop;
554	my $eol = @_ ? shift : qr|(\015?\012)|;
555	my $pos;
556		1436
		1437	if (@_ < 3) {
		1438	# this is more than twice as fast as the generic code below
		1439	sub {
		1440	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1441
		1442	$cb->($_[0], $1, $2);
		1443	1
		1444	}
		1445	} else {
557	$eol = quotemeta $eol unless ref $eol;	1446	$eol = quotemeta $eol unless ref $eol;
558	$eol = qr|^(.*?)($eol)|s;	1447	$eol = qr|^(.*?)($eol)|s;
		1448
		1449	sub {
		1450	$_[0]{rbuf} =~ s/$eol// or return;
		1451
		1452	$cb->($_[0], $1, $2);
		1453	1
		1454	}
		1455	}
		1456	};
		1457
		1458	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1459
		1460	Makes a regex match against the regex object C<$accept> and returns
		1461	everything up to and including the match.
		1462
		1463	Example: read a single line terminated by '\n'.
		1464
		1465	$handle->push_read (regex => qr<\n>, sub { ... });
		1466
		1467	If C<$reject> is given and not undef, then it determines when the data is
		1468	to be rejected: it is matched against the data when the C<$accept> regex
		1469	does not match and generates an C<EBADMSG> error when it matches. This is
		1470	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1471	receive buffer overflow).
		1472
		1473	Example: expect a single decimal number followed by whitespace, reject
		1474	anything else (not the use of an anchor).
		1475
		1476	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1477
		1478	If C<$skip> is given and not C<undef>, then it will be matched against
		1479	the receive buffer when neither C<$accept> nor C<$reject> match,
		1480	and everything preceding and including the match will be accepted
		1481	unconditionally. This is useful to skip large amounts of data that you
		1482	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1483	have to start matching from the beginning. This is purely an optimisation
		1484	and is usually worth it only when you expect more than a few kilobytes.
		1485
		1486	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1487	expect the header to be very large (it isn't in practice, but...), we use
		1488	a skip regex to skip initial portions. The skip regex is tricky in that
		1489	it only accepts something not ending in either \015 or \012, as these are
		1490	required for the accept regex.
		1491
		1492	$handle->push_read (regex =>
		1493	qr<\015\012\015\012>,
		1494	undef, # no reject
		1495	qr<^.*[^\015\012]>,
		1496	sub { ... });
		1497
		1498	=cut
		1499
		1500	register_read_type regex => sub {
		1501	my ($self, $cb, $accept, $reject, $skip) = @_;
		1502
		1503	my $data;
		1504	my $rbuf = \$self->{rbuf};
559		1505
560	sub {	1506	sub {
561	$_[0]{rbuf} =~ s/$eol// or return;	1507	# accept
		1508	if ($$rbuf =~ $accept) {
		1509	$data .= substr $$rbuf, 0, $+[0], "";
		1510	$cb->($self, $data);
		1511	return 1;
		1512	}
		1513
		1514	# reject
		1515	if ($reject && $$rbuf =~ $reject) {
		1516	$self->_error (Errno::EBADMSG);
		1517	}
562		1518
563	$cb->($_[0], $1, $2);	1519	# skip
		1520	if ($skip && $$rbuf =~ $skip) {
		1521	$data .= substr $$rbuf, 0, $+[0], "";
		1522	}
		1523
		1524	()
		1525	}
		1526	};
		1527
		1528	=item netstring => $cb->($handle, $string)
		1529
		1530	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1531
		1532	Throws an error with C<$!> set to EBADMSG on format violations.
		1533
		1534	=cut
		1535
		1536	register_read_type netstring => sub {
		1537	my ($self, $cb) = @_;
		1538
		1539	sub {
		1540	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1541	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1542	$self->_error (Errno::EBADMSG);
		1543	}
		1544	return;
		1545	}
		1546
		1547	my $len = $1;
		1548
		1549	$self->unshift_read (chunk => $len, sub {
		1550	my $string = $_[1];
		1551	$_[0]->unshift_read (chunk => 1, sub {
		1552	if ($_[1] eq ",") {
		1553	$cb->($_[0], $string);
		1554	} else {
		1555	$self->_error (Errno::EBADMSG);
		1556	}
		1557	});
		1558	});
		1559
564	1	1560	1
565	}	1561	}
566	}	1562	};
567		1563
568	sub push_read_line {	1564	=item packstring => $format, $cb->($handle, $string)
569	$_[0]->push_read (&_read_line);
570	}
571		1565
572	sub unshift_read_line {	1566	An octet string prefixed with an encoded length. The encoding C<$format>
573	$_[0]->unshift_read (&_read_line);	1567	uses the same format as a Perl C<pack> format, but must specify a single
574	}	1568	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1569	optional C<!>, C<< < >> or C<< > >> modifier).
		1570
		1571	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1572	EPP uses a prefix of C<N> (4 octtes).
		1573
		1574	Example: read a block of data prefixed by its length in BER-encoded
		1575	format (very efficient).
		1576
		1577	$handle->push_read (packstring => "w", sub {
		1578	my ($handle, $data) = @_;
		1579	});
		1580
		1581	=cut
		1582
		1583	register_read_type packstring => sub {
		1584	my ($self, $cb, $format) = @_;
		1585
		1586	sub {
		1587	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1588	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1589	or return;
		1590
		1591	$format = length pack $format, $len;
		1592
		1593	# bypass unshift if we already have the remaining chunk
		1594	if ($format + $len <= length $_[0]{rbuf}) {
		1595	my $data = substr $_[0]{rbuf}, $format, $len;
		1596	substr $_[0]{rbuf}, 0, $format + $len, "";
		1597	$cb->($_[0], $data);
		1598	} else {
		1599	# remove prefix
		1600	substr $_[0]{rbuf}, 0, $format, "";
		1601
		1602	# read remaining chunk
		1603	$_[0]->unshift_read (chunk => $len, $cb);
		1604	}
		1605
		1606	1
		1607	}
		1608	};
		1609
		1610	=item json => $cb->($handle, $hash_or_arrayref)
		1611
		1612	Reads a JSON object or array, decodes it and passes it to the
		1613	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1614
		1615	If a C<json> object was passed to the constructor, then that will be used
		1616	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1617
		1618	This read type uses the incremental parser available with JSON version
		1619	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1620	dependency on your own: this module will load the JSON module, but
		1621	AnyEvent does not depend on it itself.
		1622
		1623	Since JSON texts are fully self-delimiting, the C<json> read and write
		1624	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1625	the C<json> write type description, above, for an actual example.
		1626
		1627	=cut
		1628
		1629	register_read_type json => sub {
		1630	my ($self, $cb) = @_;
		1631
		1632	my $json = $self->{json} ||= json_coder;
		1633
		1634	my $data;
		1635	my $rbuf = \$self->{rbuf};
		1636
		1637	sub {
		1638	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1639
		1640	if ($ref) {
		1641	$self->{rbuf} = $json->incr_text;
		1642	$json->incr_text = "";
		1643	$cb->($self, $ref);
		1644
		1645	1
		1646	} elsif ($@) {
		1647	# error case
		1648	$json->incr_skip;
		1649
		1650	$self->{rbuf} = $json->incr_text;
		1651	$json->incr_text = "";
		1652
		1653	$self->_error (Errno::EBADMSG);
		1654
		1655	()
		1656	} else {
		1657	$self->{rbuf} = "";
		1658
		1659	()
		1660	}
		1661	}
		1662	};
		1663
		1664	=item storable => $cb->($handle, $ref)
		1665
		1666	Deserialises a L<Storable> frozen representation as written by the
		1667	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1668	data).
		1669
		1670	Raises C<EBADMSG> error if the data could not be decoded.
		1671
		1672	=cut
		1673
		1674	register_read_type storable => sub {
		1675	my ($self, $cb) = @_;
		1676
		1677	require Storable;
		1678
		1679	sub {
		1680	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1681	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1682	or return;
		1683
		1684	my $format = length pack "w", $len;
		1685
		1686	# bypass unshift if we already have the remaining chunk
		1687	if ($format + $len <= length $_[0]{rbuf}) {
		1688	my $data = substr $_[0]{rbuf}, $format, $len;
		1689	substr $_[0]{rbuf}, 0, $format + $len, "";
		1690	$cb->($_[0], Storable::thaw ($data));
		1691	} else {
		1692	# remove prefix
		1693	substr $_[0]{rbuf}, 0, $format, "";
		1694
		1695	# read remaining chunk
		1696	$_[0]->unshift_read (chunk => $len, sub {
		1697	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1698	$cb->($_[0], $ref);
		1699	} else {
		1700	$self->_error (Errno::EBADMSG);
		1701	}
		1702	});
		1703	}
		1704
		1705	1
		1706	}
		1707	};
		1708
		1709	=back
		1710
		1711	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1712
		1713	Instead of one of the predefined types, you can also specify the name
		1714	of a package. AnyEvent will try to load the package and then expects to
		1715	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1716	progressively tries to load the parent package until it either finds the
		1717	function (good) or runs out of packages (bad).
		1718
		1719	Whenever this type is used, C<push_read> will invoke the function with the
		1720	handle object, the original callback and the remaining arguments.
		1721
		1722	The function is supposed to return a callback (usually a closure) that
		1723	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1724	mentally treat the function as a "configurable read type to read callback"
		1725	converter.
		1726
		1727	It should invoke the original callback when it is done reading (remember
		1728	to pass C<$handle> as first argument as all other callbacks do that,
		1729	although there is no strict requirement on this).
		1730
		1731	For examples, see the source of this module (F<perldoc -m
		1732	AnyEvent::Handle>, search for C<register_read_type>)).
575		1733
576	=item $handle->stop_read	1734	=item $handle->stop_read
577		1735
578	=item $handle->start_read	1736	=item $handle->start_read
579		1737
580	In rare cases you actually do not want to read anything form the	1738	In rare cases you actually do not want to read anything from the
581	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1739	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
582	any queued callbacks will be executed then. To start readign again, call	1740	any queued callbacks will be executed then. To start reading again, call
583	C<start_read>.	1741	C<start_read>.
		1742
		1743	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1744	you change the C<on_read> callback or push/unshift a read callback, and it
		1745	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1746	there are any read requests in the queue.
		1747
		1748	These methods will have no effect when in TLS mode (as TLS doesn't support
		1749	half-duplex connections).
584		1750
585	=cut	1751	=cut
586		1752
587	sub stop_read {	1753	sub stop_read {
588	my ($self) = @_;	1754	my ($self) = @_;
589		1755
590	delete $self->{rw};	1756	delete $self->{_rw} unless $self->{tls};
591	}	1757	}
592		1758
593	sub start_read {	1759	sub start_read {
594	my ($self) = @_;	1760	my ($self) = @_;
595		1761
596	unless ($self->{rw} || $self->{eof}) {	1762	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
597	Scalar::Util::weaken $self;	1763	Scalar::Util::weaken $self;
598		1764
599	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1765	$self->{_rw} = AE::io $self->{fh}, 0, sub {
600	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1766	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
601	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1767	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
602		1768
603	if ($len > 0) {	1769	if ($len > 0) {
604	$self->{filter_r}	1770	$self->{_activity} = $self->{_ractivity} = AE::now;
605	? $self->{filter_r}->($rbuf)	1771
		1772	if ($self->{tls}) {
		1773	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1774
		1775	&_dotls ($self);
		1776	} else {
606	: $self->_drain_rbuf;	1777	$self->_drain_rbuf;
		1778	}
		1779
		1780	if ($len == $self->{read_size}) {
		1781	$self->{read_size} *= 2;
		1782	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1783	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1784	}
607		1785
608	} elsif (defined $len) {	1786	} elsif (defined $len) {
609	delete $self->{rw};	1787	delete $self->{_rw};
610	$self->{eof} = 1;	1788	$self->{_eof} = 1;
611	$self->_drain_rbuf;	1789	$self->_drain_rbuf;
612		1790
613	} elsif ($! != EAGAIN && $! != EINTR) {	1791	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
614	return $self->error;	1792	return $self->_error ($!, 1);
615	}	1793	}
616	});	1794	};
		1795	}
		1796	}
		1797
		1798	our $ERROR_SYSCALL;
		1799	our $ERROR_WANT_READ;
		1800
		1801	sub _tls_error {
		1802	my ($self, $err) = @_;
		1803
		1804	return $self->_error ($!, 1)
		1805	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1806
		1807	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1808
		1809	# reduce error string to look less scary
		1810	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1811
		1812	if ($self->{_on_starttls}) {
		1813	(delete $self->{_on_starttls})->($self, undef, $err);
		1814	&_freetls;
		1815	} else {
		1816	&_freetls;
		1817	$self->_error (Errno::EPROTO, 1, $err);
		1818	}
		1819	}
		1820
		1821	# poll the write BIO and send the data if applicable
		1822	# also decode read data if possible
		1823	# this is basiclaly our TLS state machine
		1824	# more efficient implementations are possible with openssl,
		1825	# but not with the buggy and incomplete Net::SSLeay.
		1826	sub _dotls {
		1827	my ($self) = @_;
		1828
		1829	my $tmp;
		1830
		1831	if (length $self->{_tls_wbuf}) {
		1832	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1833	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1834	}
		1835
		1836	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1837	return $self->_tls_error ($tmp)
		1838	if $tmp != $ERROR_WANT_READ
		1839	&& ($tmp != $ERROR_SYSCALL || $!);
		1840	}
		1841
		1842	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1843	unless (length $tmp) {
		1844	$self->{_on_starttls}
		1845	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1846	&_freetls;
		1847
		1848	if ($self->{on_stoptls}) {
		1849	$self->{on_stoptls}($self);
		1850	return;
		1851	} else {
		1852	# let's treat SSL-eof as we treat normal EOF
		1853	delete $self->{_rw};
		1854	$self->{_eof} = 1;
		1855	}
		1856	}
		1857
		1858	$self->{_tls_rbuf} .= $tmp;
		1859	$self->_drain_rbuf;
		1860	$self->{tls} or return; # tls session might have gone away in callback
		1861	}
		1862
		1863	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1864	return $self->_tls_error ($tmp)
		1865	if $tmp != $ERROR_WANT_READ
		1866	&& ($tmp != $ERROR_SYSCALL || $!);
		1867
		1868	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1869	$self->{wbuf} .= $tmp;
		1870	$self->_drain_wbuf;
		1871	$self->{tls} or return; # tls session might have gone away in callback
		1872	}
		1873
		1874	$self->{_on_starttls}
		1875	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1876	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1877	}
		1878
		1879	=item $handle->starttls ($tls[, $tls_ctx])
		1880
		1881	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1882	object is created, you can also do that at a later time by calling
		1883	C<starttls>.
		1884
		1885	Starting TLS is currently an asynchronous operation - when you push some
		1886	write data and then call C<< ->starttls >> then TLS negotiation will start
		1887	immediately, after which the queued write data is then sent.
		1888
		1889	The first argument is the same as the C<tls> constructor argument (either
		1890	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1891
		1892	The second argument is the optional C<AnyEvent::TLS> object that is used
		1893	when AnyEvent::Handle has to create its own TLS connection object, or
		1894	a hash reference with C<< key => value >> pairs that will be used to
		1895	construct a new context.
		1896
		1897	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1898	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1899	changed to your liking. Note that the handshake might have already started
		1900	when this function returns.
		1901
		1902	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1903	handshakes on the same stream. It is best to not attempt to use the
		1904	stream after stopping TLS.
		1905
		1906	This method may invoke callbacks (and therefore the handle might be
		1907	destroyed after it returns).
		1908
		1909	=cut
		1910
		1911	our %TLS_CACHE; #TODO not yet documented, should we?
		1912
		1913	sub starttls {
		1914	my ($self, $tls, $ctx) = @_;
		1915
		1916	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1917	if $self->{tls};
		1918
		1919	$self->{tls} = $tls;
		1920	$self->{tls_ctx} = $ctx if @_ > 2;
		1921
		1922	return unless $self->{fh};
		1923
		1924	require Net::SSLeay;
		1925
		1926	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1927	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1928
		1929	$tls = delete $self->{tls};
		1930	$ctx = $self->{tls_ctx};
		1931
		1932	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1933
		1934	if ("HASH" eq ref $ctx) {
		1935	require AnyEvent::TLS;
		1936
		1937	if ($ctx->{cache}) {
		1938	my $key = $ctx+0;
		1939	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1940	} else {
		1941	$ctx = new AnyEvent::TLS %$ctx;
		1942	}
		1943	}
		1944
		1945	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1946	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		1947
		1948	# basically, this is deep magic (because SSL_read should have the same issues)
		1949	# but the openssl maintainers basically said: "trust us, it just works".
		1950	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1951	# and mismaintained ssleay-module doesn't even offer them).
		1952	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1953	#
		1954	# in short: this is a mess.
		1955	#
		1956	# note that we do not try to keep the length constant between writes as we are required to do.
		1957	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1958	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1959	# have identity issues in that area.
		1960	# Net::SSLeay::CTX_set_mode ($ssl,
		1961	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1962	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1963	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		1964
		1965	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1966	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1967
		1968	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1969
		1970	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1971
		1972	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1973	if $self->{on_starttls};
		1974
		1975	&_dotls; # need to trigger the initial handshake
		1976	$self->start_read; # make sure we actually do read
		1977	}
		1978
		1979	=item $handle->stoptls
		1980
		1981	Shuts down the SSL connection - this makes a proper EOF handshake by
		1982	sending a close notify to the other side, but since OpenSSL doesn't
		1983	support non-blocking shut downs, it is not guaranteed that you can re-use
		1984	the stream afterwards.
		1985
		1986	This method may invoke callbacks (and therefore the handle might be
		1987	destroyed after it returns).
		1988
		1989	=cut
		1990
		1991	sub stoptls {
		1992	my ($self) = @_;
		1993
		1994	if ($self->{tls} && $self->{fh}) {
		1995	Net::SSLeay::shutdown ($self->{tls});
		1996
		1997	&_dotls;
		1998
		1999	# # we don't give a shit. no, we do, but we can't. no...#d#
		2000	# # we, we... have to use openssl :/#d#
		2001	# &_freetls;#d#
		2002	}
		2003	}
		2004
		2005	sub _freetls {
		2006	my ($self) = @_;
		2007
		2008	return unless $self->{tls};
		2009
		2010	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2011	if $self->{tls} > 0;
		2012
		2013	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2014	}
		2015
		2016	sub DESTROY {
		2017	my ($self) = @_;
		2018
		2019	&_freetls;
		2020
		2021	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2022
		2023	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2024	my $fh = delete $self->{fh};
		2025	my $wbuf = delete $self->{wbuf};
		2026
		2027	my @linger;
		2028
		2029	push @linger, AE::io $fh, 1, sub {
		2030	my $len = syswrite $fh, $wbuf, length $wbuf;
		2031
		2032	if ($len > 0) {
		2033	substr $wbuf, 0, $len, "";
		2034	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
		2035	@linger = (); # end
		2036	}
		2037	};
		2038	push @linger, AE::timer $linger, 0, sub {
		2039	@linger = ();
		2040	};
		2041	}
		2042	}
		2043
		2044	=item $handle->destroy
		2045
		2046	Shuts down the handle object as much as possible - this call ensures that
		2047	no further callbacks will be invoked and as many resources as possible
		2048	will be freed. Any method you will call on the handle object after
		2049	destroying it in this way will be silently ignored (and it will return the
		2050	empty list).
		2051
		2052	Normally, you can just "forget" any references to an AnyEvent::Handle
		2053	object and it will simply shut down. This works in fatal error and EOF
		2054	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2055	callback, so when you want to destroy the AnyEvent::Handle object from
		2056	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2057	that case.
		2058
		2059	Destroying the handle object in this way has the advantage that callbacks
		2060	will be removed as well, so if those are the only reference holders (as
		2061	is common), then one doesn't need to do anything special to break any
		2062	reference cycles.
		2063
		2064	The handle might still linger in the background and write out remaining
		2065	data, as specified by the C<linger> option, however.
		2066
		2067	=cut
		2068
		2069	sub destroy {
		2070	my ($self) = @_;
		2071
		2072	$self->DESTROY;
		2073	%$self = ();
		2074	bless $self, "AnyEvent::Handle::destroyed";
		2075	}
		2076
		2077	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2078	#nop
		2079	}
		2080
		2081	=item $handle->destroyed
		2082
		2083	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2084	->destroy >>, true otherwise.
		2085
		2086	Can be useful to decide whether the handle is still valid after some
		2087	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2088	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2089	can destroy the handle, so work can be avoided by checking sometimes:
		2090
		2091	$hdl->starttls ("accept");
		2092	return if $hdl->destroyed;
		2093	$hdl->push_write (...
		2094
		2095	Note that the call to C<push_write> will silently be ignored if the handle
		2096	has been destroyed, so often you can just ignore the possibility of the
		2097	handle being destroyed.
		2098
		2099	=cut
		2100
		2101	sub destroyed { 0 }
		2102	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2103
		2104	=item AnyEvent::Handle::TLS_CTX
		2105
		2106	This function creates and returns the AnyEvent::TLS object used by default
		2107	for TLS mode.
		2108
		2109	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2110
		2111	=cut
		2112
		2113	our $TLS_CTX;
		2114
		2115	sub TLS_CTX() {
		2116	$TLS_CTX ||= do {
		2117	require AnyEvent::TLS;
		2118
		2119	new AnyEvent::TLS
617	}	2120	}
618	}	2121	}
619		2122
620	=back	2123	=back
621		2124
		2125
		2126	=head1 NONFREQUENTLY ASKED QUESTIONS
		2127
		2128	=over 4
		2129
		2130	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2131	still get further invocations!
		2132
		2133	That's because AnyEvent::Handle keeps a reference to itself when handling
		2134	read or write callbacks.
		2135
		2136	It is only safe to "forget" the reference inside EOF or error callbacks,
		2137	from within all other callbacks, you need to explicitly call the C<<
		2138	->destroy >> method.
		2139
		2140	=item I get different callback invocations in TLS mode/Why can't I pause
		2141	reading?
		2142
		2143	Unlike, say, TCP, TLS connections do not consist of two independent
		2144	communication channels, one for each direction. Or put differently, the
		2145	read and write directions are not independent of each other: you cannot
		2146	write data unless you are also prepared to read, and vice versa.
		2147
		2148	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2149	callback invocations when you are not expecting any read data - the reason
		2150	is that AnyEvent::Handle always reads in TLS mode.
		2151
		2152	During the connection, you have to make sure that you always have a
		2153	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2154	connection (or when you no longer want to use it) you can call the
		2155	C<destroy> method.
		2156
		2157	=item How do I read data until the other side closes the connection?
		2158
		2159	If you just want to read your data into a perl scalar, the easiest way
		2160	to achieve this is by setting an C<on_read> callback that does nothing,
		2161	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2162	will be in C<$_[0]{rbuf}>:
		2163
		2164	$handle->on_read (sub { });
		2165	$handle->on_eof (undef);
		2166	$handle->on_error (sub {
		2167	my $data = delete $_[0]{rbuf};
		2168	});
		2169
		2170	The reason to use C<on_error> is that TCP connections, due to latencies
		2171	and packets loss, might get closed quite violently with an error, when in
		2172	fact all data has been received.
		2173
		2174	It is usually better to use acknowledgements when transferring data,
		2175	to make sure the other side hasn't just died and you got the data
		2176	intact. This is also one reason why so many internet protocols have an
		2177	explicit QUIT command.
		2178
		2179	=item I don't want to destroy the handle too early - how do I wait until
		2180	all data has been written?
		2181
		2182	After writing your last bits of data, set the C<on_drain> callback
		2183	and destroy the handle in there - with the default setting of
		2184	C<low_water_mark> this will be called precisely when all data has been
		2185	written to the socket:
		2186
		2187	$handle->push_write (...);
		2188	$handle->on_drain (sub {
		2189	warn "all data submitted to the kernel\n";
		2190	undef $handle;
		2191	});
		2192
		2193	If you just want to queue some data and then signal EOF to the other side,
		2194	consider using C<< ->push_shutdown >> instead.
		2195
		2196	=item I want to contact a TLS/SSL server, I don't care about security.
		2197
		2198	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2199	connect to it and then create the AnyEvent::Handle with the C<tls>
		2200	parameter:
		2201
		2202	tcp_connect $host, $port, sub {
		2203	my ($fh) = @_;
		2204
		2205	my $handle = new AnyEvent::Handle
		2206	fh => $fh,
		2207	tls => "connect",
		2208	on_error => sub { ... };
		2209
		2210	$handle->push_write (...);
		2211	};
		2212
		2213	=item I want to contact a TLS/SSL server, I do care about security.
		2214
		2215	Then you should additionally enable certificate verification, including
		2216	peername verification, if the protocol you use supports it (see
		2217	L<AnyEvent::TLS>, C<verify_peername>).
		2218
		2219	E.g. for HTTPS:
		2220
		2221	tcp_connect $host, $port, sub {
		2222	my ($fh) = @_;
		2223
		2224	my $handle = new AnyEvent::Handle
		2225	fh => $fh,
		2226	peername => $host,
		2227	tls => "connect",
		2228	tls_ctx => { verify => 1, verify_peername => "https" },
		2229	...
		2230
		2231	Note that you must specify the hostname you connected to (or whatever
		2232	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2233	peername verification will be done.
		2234
		2235	The above will use the system-dependent default set of trusted CA
		2236	certificates. If you want to check against a specific CA, add the
		2237	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2238
		2239	tls_ctx => {
		2240	verify => 1,
		2241	verify_peername => "https",
		2242	ca_file => "my-ca-cert.pem",
		2243	},
		2244
		2245	=item I want to create a TLS/SSL server, how do I do that?
		2246
		2247	Well, you first need to get a server certificate and key. You have
		2248	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2249	self-signed certificate (cheap. check the search engine of your choice,
		2250	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2251	nice program for that purpose).
		2252
		2253	Then create a file with your private key (in PEM format, see
		2254	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2255	file should then look like this:
		2256
		2257	-----BEGIN RSA PRIVATE KEY-----
		2258	...header data
		2259	... lots of base64'y-stuff
		2260	-----END RSA PRIVATE KEY-----
		2261
		2262	-----BEGIN CERTIFICATE-----
		2263	... lots of base64'y-stuff
		2264	-----END CERTIFICATE-----
		2265
		2266	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2267	specify this file as C<cert_file>:
		2268
		2269	tcp_server undef, $port, sub {
		2270	my ($fh) = @_;
		2271
		2272	my $handle = new AnyEvent::Handle
		2273	fh => $fh,
		2274	tls => "accept",
		2275	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2276	...
		2277
		2278	When you have intermediate CA certificates that your clients might not
		2279	know about, just append them to the C<cert_file>.
		2280
		2281	=back
		2282
		2283
		2284	=head1 SUBCLASSING AnyEvent::Handle
		2285
		2286	In many cases, you might want to subclass AnyEvent::Handle.
		2287
		2288	To make this easier, a given version of AnyEvent::Handle uses these
		2289	conventions:
		2290
		2291	=over 4
		2292
		2293	=item * all constructor arguments become object members.
		2294
		2295	At least initially, when you pass a C<tls>-argument to the constructor it
		2296	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2297	mutated later on (for example C<tls> will hold the TLS connection object).
		2298
		2299	=item * other object member names are prefixed with an C<_>.
		2300
		2301	All object members not explicitly documented (internal use) are prefixed
		2302	with an underscore character, so the remaining non-C<_>-namespace is free
		2303	for use for subclasses.
		2304
		2305	=item * all members not documented here and not prefixed with an underscore
		2306	are free to use in subclasses.
		2307
		2308	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2309	member variables, but that's just life. At least it is documented.
		2310
		2311	=back
		2312
622	=head1 AUTHOR	2313	=head1 AUTHOR
623		2314
624	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2315	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
625		2316
626	=cut	2317	=cut

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