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Revision 1.8 by root, Fri May 2 15:36:10 2008 UTC vs.
Revision 1.196 by root, Tue Jun 8 10:04:17 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	=cut
18
19	our $VERSION = '0.02';
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
29
30	#TODO
31
32	# or use the constructor to pass the callback:
33
34	my $ae_fh2 =
35	AnyEvent::Handle->new (
36	fh => \*STDIN,	13	fh => \*STDIN,
37	on_eof => sub {	14	on_error => sub {
38	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
39	},	16	warn "got error $msg\n";
40	#TODO	17	$hdl->destroy;
		18	$cv->send;
41	);	19	};
42		20
43	$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;
44		32
45	=head1 DESCRIPTION	33	=head1 DESCRIPTION
46		34
47	This module is a helper module to make it easier to do event-based I/O on	35	This module is a helper module to make it easier to do event-based I/O on
48	filehandles (and sockets, see L<AnyEvent::Socket> for an easy way to make	36	stream-based filehandles (sockets, pipes or other stream things).
49	non-blocking resolves and connects).	37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
50		40
51	In the following, when the documentation refers to of "bytes" then this	41	In the following, when the documentation refers to of "bytes" then this
52	means characters. As sysread and syswrite are used for all I/O, their	42	means characters. As sysread and syswrite are used for all I/O, their
53	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
54		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
55	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
56	argument.	49	argument.
57		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
58	=head1 METHODS	80	=head1 METHODS
59		81
60	=over 4	82	=over 4
61		83
62	=item B<new (%args)>	84	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
63		85
64	The constructor supports these arguments (all as key => value pairs).	86	The constructor supports these arguments (all as C<< key => value >> pairs).
65		87
66	=over 4	88	=over 4
67		89
68	=item fh => $filehandle [MANDATORY]	90	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
69		91
70	The filehandle this L<AnyEvent::Handle> object will operate on.	92	The filehandle this L<AnyEvent::Handle> object will operate on.
71
72	NOTE: The filehandle will be set to non-blocking (using	93	NOTE: The filehandle will be set to non-blocking mode (using
73	AnyEvent::Util::fh_nonblocking).	94	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		95	that mode.
74		96
75	=item on_error => $cb->($self) [MANDATORY]	97	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
76		98
77	This is the fatal error callback, that is called when a fatal error ocurs,	99	Try to connect to the specified host and service (port), using
		100	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		101	default C<peername>.
		102
		103	You have to specify either this parameter, or C<fh>, above.
		104
		105	It is possible to push requests on the read and write queues, and modify
		106	properties of the stream, even while AnyEvent::Handle is connecting.
		107
		108	When this parameter is specified, then the C<on_prepare>,
		109	C<on_connect_error> and C<on_connect> callbacks will be called under the
		110	appropriate circumstances:
		111
		112	=over 4
		113
		114	=item on_prepare => $cb->($handle)
		115
		116	This (rarely used) callback is called before a new connection is
		117	attempted, but after the file handle has been created. It could be used to
		118	prepare the file handle with parameters required for the actual connect
		119	(as opposed to settings that can be changed when the connection is already
		120	established).
		121
		122	The return value of this callback should be the connect timeout value in
		123	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		124	timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The actual numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	When, for some reason, the handle is not acceptable, then calling
		134	C<$retry> will continue with the next connection target (in case of
		135	multi-homed hosts or SRV records there can be multiple connection
		136	endpoints). At the time it is called the read and write queues, eof
		137	status, tls status and similar properties of the handle will have been
		138	reset.
		139
		140	In most cases, ignoring the C<$retry> parameter is the way to go.
		141
		142	=item on_connect_error => $cb->($handle, $message)
		143
		144	This callback is called when the connection could not be
		145	established. C<$!> will contain the relevant error code, and C<$message> a
		146	message describing it (usually the same as C<"$!">).
		147
		148	If this callback isn't specified, then C<on_error> will be called with a
		149	fatal error instead.
		150
		151	=back
		152
		153	=item on_error => $cb->($handle, $fatal, $message)
		154
		155	This is the error callback, which is called when, well, some error
78	such as not being able to resolve the hostname, failure to connect or a	156	occured, such as not being able to resolve the hostname, failure to
79	read error.	157	connect or a read error.
80		158
81	The object will not be in a usable state when this callback has been	159	Some errors are fatal (which is indicated by C<$fatal> being true). On
82	called.	160	fatal errors the handle object will be destroyed (by a call to C<< ->
		161	destroy >>) after invoking the error callback (which means you are free to
		162	examine the handle object). Examples of fatal errors are an EOF condition
		163	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		164	cases where the other side can close the connection at their will it is
		165	often easiest to not report C<EPIPE> errors in this callback.
83		166
		167	AnyEvent::Handle tries to find an appropriate error code for you to check
		168	against, but in some cases (TLS errors), this does not work well. It is
		169	recommended to always output the C<$message> argument in human-readable
		170	error messages (it's usually the same as C<"$!">).
		171
		172	Non-fatal errors can be retried by simply returning, but it is recommended
		173	to simply ignore this parameter and instead abondon the handle object
		174	when this callback is invoked. Examples of non-fatal errors are timeouts
		175	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		176
84	On callback entrance, the value of C<$!> contains the opertaing system	177	On callback entrance, the value of C<$!> contains the operating system
85	error (or C<ENOSPC> or C<EPIPE>).	178	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		179	C<EPROTO>).
86		180
87	=item on_eof => $cb->($self) [MANDATORY]	181	While not mandatory, it is I<highly> recommended to set this callback, as
		182	you will not be notified of errors otherwise. The default simply calls
		183	C<croak>.
88		184
89	Set the callback to be called on EOF.
90
91	=item on_read => $cb->($self)	185	=item on_read => $cb->($handle)
92		186
93	This sets the default read callback, which is called when data arrives	187	This sets the default read callback, which is called when data arrives
94	and no read request is in the queue. If the read callback is C<undef>	188	and no read request is in the queue (unlike read queue callbacks, this
95	or has never been set, than AnyEvent::Handle will cease reading from the	189	callback will only be called when at least one octet of data is in the
96	filehandle.	190	read buffer).
97		191
98	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	192	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
99	method or acces sthe C<$self->{rbuf}> member directly.	193	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		194	must not enlarge or modify the read buffer, you can only remove data at
		195	the beginning from it.
100		196
101	When an EOF condition is detected then AnyEvent::Handle will first try to	197	When an EOF condition is detected then AnyEvent::Handle will first try to
102	feed all the remaining data to the queued callbacks and C<on_read> before	198	feed all the remaining data to the queued callbacks and C<on_read> before
103	calling the C<on_eof> callback. If no progress can be made, then a fatal	199	calling the C<on_eof> callback. If no progress can be made, then a fatal
104	error will be raised (with C<$!> set to C<EPIPE>).	200	error will be raised (with C<$!> set to C<EPIPE>).
105		201
		202	Note that, unlike requests in the read queue, an C<on_read> callback
		203	doesn't mean you I<require> some data: if there is an EOF and there
		204	are outstanding read requests then an error will be flagged. With an
		205	C<on_read> callback, the C<on_eof> callback will be invoked.
		206
		207	=item on_eof => $cb->($handle)
		208
		209	Set the callback to be called when an end-of-file condition is detected,
		210	i.e. in the case of a socket, when the other side has closed the
		211	connection cleanly, and there are no outstanding read requests in the
		212	queue (if there are read requests, then an EOF counts as an unexpected
		213	connection close and will be flagged as an error).
		214
		215	For sockets, this just means that the other side has stopped sending data,
		216	you can still try to write data, and, in fact, one can return from the EOF
		217	callback and continue writing data, as only the read part has been shut
		218	down.
		219
		220	If an EOF condition has been detected but no C<on_eof> callback has been
		221	set, then a fatal error will be raised with C<$!> set to <0>.
		222
106	=item on_drain => $cb->()	223	=item on_drain => $cb->($handle)
107		224
108	This sets the callback that is called when the write buffer becomes empty	225	This sets the callback that is called when the write buffer becomes empty
109	(or when the callback is set and the buffer is empty already).	226	(or when the callback is set and the buffer is empty already).
110		227
111	To append to the write buffer, use the C<< ->push_write >> method.	228	To append to the write buffer, use the C<< ->push_write >> method.
112		229
		230	This callback is useful when you don't want to put all of your write data
		231	into the queue at once, for example, when you want to write the contents
		232	of some file to the socket you might not want to read the whole file into
		233	memory and push it into the queue, but instead only read more data from
		234	the file when the write queue becomes empty.
		235
		236	=item timeout => $fractional_seconds
		237
		238	=item rtimeout => $fractional_seconds
		239
		240	=item wtimeout => $fractional_seconds
		241
		242	If non-zero, then these enables an "inactivity" timeout: whenever this
		243	many seconds pass without a successful read or write on the underlying
		244	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		245	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		246	error will be raised).
		247
		248	There are three variants of the timeouts that work fully independent
		249	of each other, for both read and write, just read, and just write:
		250	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		251	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		252	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		253
		254	Note that timeout processing is also active when you currently do not have
		255	any outstanding read or write requests: If you plan to keep the connection
		256	idle then you should disable the timout temporarily or ignore the timeout
		257	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		258	restart the timeout.
		259
		260	Zero (the default) disables this timeout.
		261
		262	=item on_timeout => $cb->($handle)
		263
		264	Called whenever the inactivity timeout passes. If you return from this
		265	callback, then the timeout will be reset as if some activity had happened,
		266	so this condition is not fatal in any way.
		267
113	=item rbuf_max => <bytes>	268	=item rbuf_max => <bytes>
114		269
115	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	270	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
116	when the read buffer ever (strictly) exceeds this size. This is useful to	271	when the read buffer ever (strictly) exceeds this size. This is useful to
117	avoid denial-of-service attacks.	272	avoid some forms of denial-of-service attacks.
118		273
119	For example, a server accepting connections from untrusted sources should	274	For example, a server accepting connections from untrusted sources should
120	be configured to accept only so-and-so much data that it cannot act on	275	be configured to accept only so-and-so much data that it cannot act on
121	(for example, when expecting a line, an attacker could send an unlimited	276	(for example, when expecting a line, an attacker could send an unlimited
122	amount of data without a callback ever being called as long as the line	277	amount of data without a callback ever being called as long as the line
123	isn't finished).	278	isn't finished).
124		279
		280	=item autocork => <boolean>
		281
		282	When disabled (the default), then C<push_write> will try to immediately
		283	write the data to the handle, if possible. This avoids having to register
		284	a write watcher and wait for the next event loop iteration, but can
		285	be inefficient if you write multiple small chunks (on the wire, this
		286	disadvantage is usually avoided by your kernel's nagle algorithm, see
		287	C<no_delay>, but this option can save costly syscalls).
		288
		289	When enabled, then writes will always be queued till the next event loop
		290	iteration. This is efficient when you do many small writes per iteration,
		291	but less efficient when you do a single write only per iteration (or when
		292	the write buffer often is full). It also increases write latency.
		293
		294	=item no_delay => <boolean>
		295
		296	When doing small writes on sockets, your operating system kernel might
		297	wait a bit for more data before actually sending it out. This is called
		298	the Nagle algorithm, and usually it is beneficial.
		299
		300	In some situations you want as low a delay as possible, which can be
		301	accomplishd by setting this option to a true value.
		302
		303	The default is your opertaing system's default behaviour (most likely
		304	enabled), this option explicitly enables or disables it, if possible.
		305
		306	=item keepalive => <boolean>
		307
		308	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		309	normally, TCP connections have no time-out once established, so TCP
		310	connections, once established, can stay alive forever even when the other
		311	side has long gone. TCP keepalives are a cheap way to take down long-lived
		312	TCP connections whent he other side becomes unreachable. While the default
		313	is OS-dependent, TCP keepalives usually kick in after around two hours,
		314	and, if the other side doesn't reply, take down the TCP connection some 10
		315	to 15 minutes later.
		316
		317	It is harmless to specify this option for file handles that do not support
		318	keepalives, and enabling it on connections that are potentially long-lived
		319	is usually a good idea.
		320
		321	=item oobinline => <boolean>
		322
		323	BSD majorly fucked up the implementation of TCP urgent data. The result
		324	is that almost no OS implements TCP according to the specs, and every OS
		325	implements it slightly differently.
		326
		327	If you want to handle TCP urgent data, then setting this flag (the default
		328	is enabled) gives you the most portable way of getting urgent data, by
		329	putting it into the stream.
		330
		331	Since BSD emulation of OOB data on top of TCP's urgent data can have
		332	security implications, AnyEvent::Handle sets this flag automatically
		333	unless explicitly specified. Note that setting this flag after
		334	establishing a connection I<may> be a bit too late (data loss could
		335	already have occured on BSD systems), but at least it will protect you
		336	from most attacks.
		337
125	=item read_size => <bytes>	338	=item read_size => <bytes>
126		339
127	The default read block size (the amount of bytes this module will try to read	340	The default read block size (the amount of bytes this module will
128	on each [loop iteration). Default: C<4096>.	341	try to read during each loop iteration, which affects memory
		342	requirements). Default: C<8192>.
129		343
130	=item low_water_mark => <bytes>	344	=item low_water_mark => <bytes>
131		345
132	Sets the amount of bytes (default: C<0>) that make up an "empty" write	346	Sets the amount of bytes (default: C<0>) that make up an "empty" write
133	buffer: If the write reaches this size or gets even samller it is	347	buffer: If the write reaches this size or gets even samller it is
134	considered empty.	348	considered empty.
135		349
		350	Sometimes it can be beneficial (for performance reasons) to add data to
		351	the write buffer before it is fully drained, but this is a rare case, as
		352	the operating system kernel usually buffers data as well, so the default
		353	is good in almost all cases.
		354
		355	=item linger => <seconds>
		356
		357	If non-zero (default: C<3600>), then the destructor of the
		358	AnyEvent::Handle object will check whether there is still outstanding
		359	write data and will install a watcher that will write this data to the
		360	socket. No errors will be reported (this mostly matches how the operating
		361	system treats outstanding data at socket close time).
		362
		363	This will not work for partial TLS data that could not be encoded
		364	yet. This data will be lost. Calling the C<stoptls> method in time might
		365	help.
		366
		367	=item peername => $string
		368
		369	A string used to identify the remote site - usually the DNS hostname
		370	(I<not> IDN!) used to create the connection, rarely the IP address.
		371
		372	Apart from being useful in error messages, this string is also used in TLS
		373	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		374	verification will be skipped when C<peername> is not specified or
		375	C<undef>.
		376
		377	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		378
		379	When this parameter is given, it enables TLS (SSL) mode, that means
		380	AnyEvent will start a TLS handshake as soon as the connection has been
		381	established and will transparently encrypt/decrypt data afterwards.
		382
		383	All TLS protocol errors will be signalled as C<EPROTO>, with an
		384	appropriate error message.
		385
		386	TLS mode requires Net::SSLeay to be installed (it will be loaded
		387	automatically when you try to create a TLS handle): this module doesn't
		388	have a dependency on that module, so if your module requires it, you have
		389	to add the dependency yourself.
		390
		391	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		392	C<accept>, and for the TLS client side of a connection, use C<connect>
		393	mode.
		394
		395	You can also provide your own TLS connection object, but you have
		396	to make sure that you call either C<Net::SSLeay::set_connect_state>
		397	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		398	AnyEvent::Handle. Also, this module will take ownership of this connection
		399	object.
		400
		401	At some future point, AnyEvent::Handle might switch to another TLS
		402	implementation, then the option to use your own session object will go
		403	away.
		404
		405	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		406	passing in the wrong integer will lead to certain crash. This most often
		407	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		408	segmentation fault.
		409
		410	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		411
		412	=item tls_ctx => $anyevent_tls
		413
		414	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		415	(unless a connection object was specified directly). If this parameter is
		416	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		417
		418	Instead of an object, you can also specify a hash reference with C<< key
		419	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		420	new TLS context object.
		421
		422	=item on_starttls => $cb->($handle, $success[, $error_message])
		423
		424	This callback will be invoked when the TLS/SSL handshake has finished. If
		425	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		426	(C<on_stoptls> will not be called in this case).
		427
		428	The session in C<< $handle->{tls} >> can still be examined in this
		429	callback, even when the handshake was not successful.
		430
		431	TLS handshake failures will not cause C<on_error> to be invoked when this
		432	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		433
		434	Without this callback, handshake failures lead to C<on_error> being
		435	called, as normal.
		436
		437	Note that you cannot call C<starttls> right again in this callback. If you
		438	need to do that, start an zero-second timer instead whose callback can
		439	then call C<< ->starttls >> again.
		440
		441	=item on_stoptls => $cb->($handle)
		442
		443	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		444	set, then it will be invoked after freeing the TLS session. If it is not,
		445	then a TLS shutdown condition will be treated like a normal EOF condition
		446	on the handle.
		447
		448	The session in C<< $handle->{tls} >> can still be examined in this
		449	callback.
		450
		451	This callback will only be called on TLS shutdowns, not when the
		452	underlying handle signals EOF.
		453
		454	=item json => JSON or JSON::XS object
		455
		456	This is the json coder object used by the C<json> read and write types.
		457
		458	If you don't supply it, then AnyEvent::Handle will create and use a
		459	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		460	texts.
		461
		462	Note that you are responsible to depend on the JSON module if you want to
		463	use this functionality, as AnyEvent does not have a dependency itself.
		464
136	=back	465	=back
137		466
138	=cut	467	=cut
139		468
140	sub new {	469	sub new {
141	my $class = shift;	470	my $class = shift;
142
143	my $self = bless { @_ }, $class;	471	my $self = bless { @_ }, $class;
144		472
145	$self->{fh} or Carp::croak "mandatory argument fh is missing";	473	if ($self->{fh}) {
		474	$self->_start;
		475	return unless $self->{fh}; # could be gone by now
		476
		477	} elsif ($self->{connect}) {
		478	require AnyEvent::Socket;
		479
		480	$self->{peername} = $self->{connect}[0]
		481	unless exists $self->{peername};
		482
		483	$self->{_skip_drain_rbuf} = 1;
		484
		485	{
		486	Scalar::Util::weaken (my $self = $self);
		487
		488	$self->{_connect} =
		489	AnyEvent::Socket::tcp_connect (
		490	$self->{connect}[0],
		491	$self->{connect}[1],
		492	sub {
		493	my ($fh, $host, $port, $retry) = @_;
		494
		495	if ($fh) {
		496	$self->{fh} = $fh;
		497
		498	delete $self->{_skip_drain_rbuf};
		499	$self->_start;
		500
		501	$self->{on_connect}
		502	and $self->{on_connect}($self, $host, $port, sub {
		503	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		504	$self->{_skip_drain_rbuf} = 1;
		505	&$retry;
		506	});
		507
		508	} else {
		509	if ($self->{on_connect_error}) {
		510	$self->{on_connect_error}($self, "$!");
		511	$self->destroy;
		512	} else {
		513	$self->_error ($!, 1);
		514	}
		515	}
		516	},
		517	sub {
		518	local $self->{fh} = $_[0];
		519
		520	$self->{on_prepare}
		521	? $self->{on_prepare}->($self)
		522	: ()
		523	}
		524	);
		525	}
		526
		527	} else {
		528	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		529	}
		530
		531	$self
		532	}
		533
		534	sub _start {
		535	my ($self) = @_;
		536
		537	# too many clueless people try to use udp and similar sockets
		538	# with AnyEvent::Handle, do them a favour.
		539	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		540	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		541	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
146		542
147	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	543	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
148		544
149	$self->on_error ((delete $self->{on_error}) or Carp::croak "mandatory argument on_error is missing");	545	$self->{_activity} =
150	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	546	$self->{_ractivity} =
		547	$self->{_wactivity} = AE::now;
151		548
		549	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		550	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		551	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		552
		553	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		554	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		555
		556	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		557
		558	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		559	if $self->{tls};
		560
152	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	561	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
153	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
154		562
155	$self	563	$self->start_read
156	}	564	if $self->{on_read} || @{ $self->{_queue} };
157		565
158	sub _shutdown {	566	$self->_drain_wbuf;
159	my ($self) = @_;
160
161	delete $self->{rw};
162	delete $self->{ww};
163	delete $self->{fh};
164	}	567	}
165		568
166	sub error {	569	sub _error {
167	my ($self) = @_;	570	my ($self, $errno, $fatal, $message) = @_;
168		571
169	{	572	$! = $errno;
170	local $!;	573	$message ||= "$!";
		574
		575	if ($self->{on_error}) {
		576	$self->{on_error}($self, $fatal, $message);
		577	$self->destroy if $fatal;
		578	} elsif ($self->{fh} || $self->{connect}) {
171	$self->_shutdown;	579	$self->destroy;
		580	Carp::croak "AnyEvent::Handle uncaught error: $message";
172	}	581	}
173
174	$self->{on_error}($self);
175	}	582	}
176		583
177	=item $fh = $handle->fh	584	=item $fh = $handle->fh
178		585
179	This method returns the filehandle of the L<AnyEvent::Handle> object.	586	This method returns the file handle used to create the L<AnyEvent::Handle> object.
180		587
181	=cut	588	=cut
182		589
183	sub fh { $_[0]->{fh} }	590	sub fh { $_[0]{fh} }
184		591
185	=item $handle->on_error ($cb)	592	=item $handle->on_error ($cb)
186		593
187	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	594	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
188		595
…		…
196		603
197	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).	604	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
198		605
199	=cut	606	=cut
200		607
201	#############################################################################
202
203	sub on_eof {	608	sub on_eof {
204	$_[0]{on_eof} = $_[1];	609	$_[0]{on_eof} = $_[1];
205	}	610	}
206		611
		612	=item $handle->on_timeout ($cb)
		613
		614	=item $handle->on_rtimeout ($cb)
		615
		616	=item $handle->on_wtimeout ($cb)
		617
		618	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		619	callback, or disables the callback (but not the timeout) if C<$cb> =
		620	C<undef>. See the C<timeout> constructor argument and method.
		621
		622	=cut
		623
		624	# see below
		625
		626	=item $handle->autocork ($boolean)
		627
		628	Enables or disables the current autocork behaviour (see C<autocork>
		629	constructor argument). Changes will only take effect on the next write.
		630
		631	=cut
		632
		633	sub autocork {
		634	$_[0]{autocork} = $_[1];
		635	}
		636
		637	=item $handle->no_delay ($boolean)
		638
		639	Enables or disables the C<no_delay> setting (see constructor argument of
		640	the same name for details).
		641
		642	=cut
		643
		644	sub no_delay {
		645	$_[0]{no_delay} = $_[1];
		646
		647	eval {
		648	local $SIG{__DIE__};
		649	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		650	if $_[0]{fh};
		651	};
		652	}
		653
		654	=item $handle->keepalive ($boolean)
		655
		656	Enables or disables the C<keepalive> setting (see constructor argument of
		657	the same name for details).
		658
		659	=cut
		660
		661	sub keepalive {
		662	$_[0]{keepalive} = $_[1];
		663
		664	eval {
		665	local $SIG{__DIE__};
		666	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		667	if $_[0]{fh};
		668	};
		669	}
		670
		671	=item $handle->oobinline ($boolean)
		672
		673	Enables or disables the C<oobinline> setting (see constructor argument of
		674	the same name for details).
		675
		676	=cut
		677
		678	sub oobinline {
		679	$_[0]{oobinline} = $_[1];
		680
		681	eval {
		682	local $SIG{__DIE__};
		683	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		684	if $_[0]{fh};
		685	};
		686	}
		687
		688	=item $handle->keepalive ($boolean)
		689
		690	Enables or disables the C<keepalive> setting (see constructor argument of
		691	the same name for details).
		692
		693	=cut
		694
		695	sub keepalive {
		696	$_[0]{keepalive} = $_[1];
		697
		698	eval {
		699	local $SIG{__DIE__};
		700	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		701	if $_[0]{fh};
		702	};
		703	}
		704
		705	=item $handle->on_starttls ($cb)
		706
		707	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		708
		709	=cut
		710
		711	sub on_starttls {
		712	$_[0]{on_starttls} = $_[1];
		713	}
		714
		715	=item $handle->on_stoptls ($cb)
		716
		717	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		718
		719	=cut
		720
		721	sub on_stoptls {
		722	$_[0]{on_stoptls} = $_[1];
		723	}
		724
		725	=item $handle->rbuf_max ($max_octets)
		726
		727	Configures the C<rbuf_max> setting (C<undef> disables it).
		728
		729	=cut
		730
		731	sub rbuf_max {
		732	$_[0]{rbuf_max} = $_[1];
		733	}
		734
		735	#############################################################################
		736
		737	=item $handle->timeout ($seconds)
		738
		739	=item $handle->rtimeout ($seconds)
		740
		741	=item $handle->wtimeout ($seconds)
		742
		743	Configures (or disables) the inactivity timeout.
		744
		745	=item $handle->timeout_reset
		746
		747	=item $handle->rtimeout_reset
		748
		749	=item $handle->wtimeout_reset
		750
		751	Reset the activity timeout, as if data was received or sent.
		752
		753	These methods are cheap to call.
		754
		755	=cut
		756
		757	for my $dir ("", "r", "w") {
		758	my $timeout = "${dir}timeout";
		759	my $tw = "_${dir}tw";
		760	my $on_timeout = "on_${dir}timeout";
		761	my $activity = "_${dir}activity";
		762	my $cb;
		763
		764	*$on_timeout = sub {
		765	$_[0]{$on_timeout} = $_[1];
		766	};
		767
		768	*$timeout = sub {
		769	my ($self, $new_value) = @_;
		770
		771	$self->{$timeout} = $new_value;
		772	delete $self->{$tw}; &$cb;
		773	};
		774
		775	*{"${dir}timeout_reset"} = sub {
		776	$_[0]{$activity} = AE::now;
		777	};
		778
		779	# main workhorse:
		780	# reset the timeout watcher, as neccessary
		781	# also check for time-outs
		782	$cb = sub {
		783	my ($self) = @_;
		784
		785	if ($self->{$timeout} && $self->{fh}) {
		786	my $NOW = AE::now;
		787
		788	# when would the timeout trigger?
		789	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		790
		791	# now or in the past already?
		792	if ($after <= 0) {
		793	$self->{$activity} = $NOW;
		794
		795	if ($self->{$on_timeout}) {
		796	$self->{$on_timeout}($self);
		797	} else {
		798	$self->_error (Errno::ETIMEDOUT);
		799	}
		800
		801	# callback could have changed timeout value, optimise
		802	return unless $self->{$timeout};
		803
		804	# calculate new after
		805	$after = $self->{$timeout};
		806	}
		807
		808	Scalar::Util::weaken $self;
		809	return unless $self; # ->error could have destroyed $self
		810
		811	$self->{$tw} ||= AE::timer $after, 0, sub {
		812	delete $self->{$tw};
		813	$cb->($self);
		814	};
		815	} else {
		816	delete $self->{$tw};
		817	}
		818	}
		819	}
		820
		821	#############################################################################
		822
		823	=back
		824
		825	=head2 WRITE QUEUE
		826
		827	AnyEvent::Handle manages two queues per handle, one for writing and one
		828	for reading.
		829
		830	The write queue is very simple: you can add data to its end, and
		831	AnyEvent::Handle will automatically try to get rid of it for you.
		832
		833	When data could be written and the write buffer is shorter then the low
		834	water mark, the C<on_drain> callback will be invoked.
		835
		836	=over 4
		837
207	=item $handle->on_drain ($cb)	838	=item $handle->on_drain ($cb)
208		839
209	Sets the C<on_drain> callback or clears it (see the description of	840	Sets the C<on_drain> callback or clears it (see the description of
210	C<on_drain> in the constructor).	841	C<on_drain> in the constructor).
211		842
		843	This method may invoke callbacks (and therefore the handle might be
		844	destroyed after it returns).
		845
212	=cut	846	=cut
213		847
214	sub on_drain {	848	sub on_drain {
215	my ($self, $cb) = @_;	849	my ($self, $cb) = @_;
216		850
217	$self->{on_drain} = $cb;	851	$self->{on_drain} = $cb;
218		852
219	$cb->($self)	853	$cb->($self)
220	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	854	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
221	}	855	}
222		856
223	=item $handle->push_write ($data)	857	=item $handle->push_write ($data)
224		858
225	Queues the given scalar to be written. You can push as much data as you	859	Queues the given scalar to be written. You can push as much data as you
226	want (only limited by the available memory), as C<AnyEvent::Handle>	860	want (only limited by the available memory), as C<AnyEvent::Handle>
227	buffers it independently of the kernel.	861	buffers it independently of the kernel.
228		862
229	=cut	863	This method may invoke callbacks (and therefore the handle might be
		864	destroyed after it returns).
230		865
231	sub push_write {	866	=cut
		867
		868	sub _drain_wbuf {
232	my ($self, $data) = @_;	869	my ($self) = @_;
233		870
234	$self->{wbuf} .= $data;	871	if (!$self->{_ww} && length $self->{wbuf}) {
235		872
236	unless ($self->{ww}) {
237	Scalar::Util::weaken $self;	873	Scalar::Util::weaken $self;
		874
238	my $cb = sub {	875	my $cb = sub {
239	my $len = syswrite $self->{fh}, $self->{wbuf};	876	my $len = syswrite $self->{fh}, $self->{wbuf};
240		877
241	if ($len > 0) {	878	if (defined $len) {
242	substr $self->{wbuf}, 0, $len, "";	879	substr $self->{wbuf}, 0, $len, "";
243		880
		881	$self->{_activity} = $self->{_wactivity} = AE::now;
244		882
245	$self->{on_drain}($self)	883	$self->{on_drain}($self)
246	if $self->{low_water_mark} >= length $self->{wbuf}	884	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
247	&& $self->{on_drain};	885	&& $self->{on_drain};
248		886
249	delete $self->{ww} unless length $self->{wbuf};	887	delete $self->{_ww} unless length $self->{wbuf};
250	} elsif ($! != EAGAIN && $! != EINTR) {	888	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
251	$self->error;	889	$self->_error ($!, 1);
252	}	890	}
253	};	891	};
254		892
255	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	893	# try to write data immediately
		894	$cb->() unless $self->{autocork};
256		895
257	$cb->($self);	896	# if still data left in wbuf, we need to poll
		897	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		898	if length $self->{wbuf};
258	};	899	};
259	}	900	}
260		901
		902	our %WH;
		903
		904	# deprecated
		905	sub register_write_type($$) {
		906	$WH{$_[0]} = $_[1];
		907	}
		908
		909	sub push_write {
		910	my $self = shift;
		911
		912	if (@_ > 1) {
		913	my $type = shift;
		914
		915	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		916	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		917	->($self, @_);
		918	}
		919
		920	# we downgrade here to avoid hard-to-track-down bugs,
		921	# and diagnose the problem earlier and better.
		922
		923	if ($self->{tls}) {
		924	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		925	&_dotls ($self) if $self->{fh};
		926	} else {
		927	utf8::downgrade $self->{wbuf} .= $_[0];
		928	$self->_drain_wbuf if $self->{fh};
		929	}
		930	}
		931
		932	=item $handle->push_write (type => @args)
		933
		934	Instead of formatting your data yourself, you can also let this module
		935	do the job by specifying a type and type-specific arguments. You
		936	can also specify the (fully qualified) name of a package, in which
		937	case AnyEvent tries to load the package and then expects to find the
		938	C<anyevent_read_type> function inside (see "custom write types", below).
		939
		940	Predefined types are (if you have ideas for additional types, feel free to
		941	drop by and tell us):
		942
		943	=over 4
		944
		945	=item netstring => $string
		946
		947	Formats the given value as netstring
		948	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		949
		950	=cut
		951
		952	register_write_type netstring => sub {
		953	my ($self, $string) = @_;
		954
		955	(length $string) . ":$string,"
		956	};
		957
		958	=item packstring => $format, $data
		959
		960	An octet string prefixed with an encoded length. The encoding C<$format>
		961	uses the same format as a Perl C<pack> format, but must specify a single
		962	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		963	optional C<!>, C<< < >> or C<< > >> modifier).
		964
		965	=cut
		966
		967	register_write_type packstring => sub {
		968	my ($self, $format, $string) = @_;
		969
		970	pack "$format/a*", $string
		971	};
		972
		973	=item json => $array_or_hashref
		974
		975	Encodes the given hash or array reference into a JSON object. Unless you
		976	provide your own JSON object, this means it will be encoded to JSON text
		977	in UTF-8.
		978
		979	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		980	one end of a handle and read them at the other end without using any
		981	additional framing.
		982
		983	The generated JSON text is guaranteed not to contain any newlines: While
		984	this module doesn't need delimiters after or between JSON texts to be
		985	able to read them, many other languages depend on that.
		986
		987	A simple RPC protocol that interoperates easily with others is to send
		988	JSON arrays (or objects, although arrays are usually the better choice as
		989	they mimic how function argument passing works) and a newline after each
		990	JSON text:
		991
		992	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		993	$handle->push_write ("\012");
		994
		995	An AnyEvent::Handle receiver would simply use the C<json> read type and
		996	rely on the fact that the newline will be skipped as leading whitespace:
		997
		998	$handle->push_read (json => sub { my $array = $_[1]; ... });
		999
		1000	Other languages could read single lines terminated by a newline and pass
		1001	this line into their JSON decoder of choice.
		1002
		1003	=cut
		1004
		1005	sub json_coder() {
		1006	eval { require JSON::XS; JSON::XS->new->utf8 }
		1007	|| do { require JSON; JSON->new->utf8 }
		1008	}
		1009
		1010	register_write_type json => sub {
		1011	my ($self, $ref) = @_;
		1012
		1013	my $json = $self->{json} ||= json_coder;
		1014
		1015	$json->encode ($ref)
		1016	};
		1017
		1018	=item storable => $reference
		1019
		1020	Freezes the given reference using L<Storable> and writes it to the
		1021	handle. Uses the C<nfreeze> format.
		1022
		1023	=cut
		1024
		1025	register_write_type storable => sub {
		1026	my ($self, $ref) = @_;
		1027
		1028	require Storable;
		1029
		1030	pack "w/a*", Storable::nfreeze ($ref)
		1031	};
		1032
		1033	=back
		1034
		1035	=item $handle->push_shutdown
		1036
		1037	Sometimes you know you want to close the socket after writing your data
		1038	before it was actually written. One way to do that is to replace your
		1039	C<on_drain> handler by a callback that shuts down the socket (and set
		1040	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1041	replaces the C<on_drain> callback with:
		1042
		1043	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1044
		1045	This simply shuts down the write side and signals an EOF condition to the
		1046	the peer.
		1047
		1048	You can rely on the normal read queue and C<on_eof> handling
		1049	afterwards. This is the cleanest way to close a connection.
		1050
		1051	This method may invoke callbacks (and therefore the handle might be
		1052	destroyed after it returns).
		1053
		1054	=cut
		1055
		1056	sub push_shutdown {
		1057	my ($self) = @_;
		1058
		1059	delete $self->{low_water_mark};
		1060	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1061	}
		1062
		1063	=item custom write types - Package::anyevent_write_type $handle, @args
		1064
		1065	Instead of one of the predefined types, you can also specify the name of
		1066	a package. AnyEvent will try to load the package and then expects to find
		1067	a function named C<anyevent_write_type> inside. If it isn't found, it
		1068	progressively tries to load the parent package until it either finds the
		1069	function (good) or runs out of packages (bad).
		1070
		1071	Whenever the given C<type> is used, C<push_write> will the function with
		1072	the handle object and the remaining arguments.
		1073
		1074	The function is supposed to return a single octet string that will be
		1075	appended to the write buffer, so you cna mentally treat this function as a
		1076	"arguments to on-the-wire-format" converter.
		1077
		1078	Example: implement a custom write type C<join> that joins the remaining
		1079	arguments using the first one.
		1080
		1081	$handle->push_write (My::Type => " ", 1,2,3);
		1082
		1083	# uses the following package, which can be defined in the "My::Type" or in
		1084	# the "My" modules to be auto-loaded, or just about anywhere when the
		1085	# My::Type::anyevent_write_type is defined before invoking it.
		1086
		1087	package My::Type;
		1088
		1089	sub anyevent_write_type {
		1090	my ($handle, $delim, @args) = @_;
		1091
		1092	join $delim, @args
		1093	}
		1094
		1095	=cut
		1096
261	#############################################################################	1097	#############################################################################
		1098
		1099	=back
		1100
		1101	=head2 READ QUEUE
		1102
		1103	AnyEvent::Handle manages two queues per handle, one for writing and one
		1104	for reading.
		1105
		1106	The read queue is more complex than the write queue. It can be used in two
		1107	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1108	a queue.
		1109
		1110	In the simple case, you just install an C<on_read> callback and whenever
		1111	new data arrives, it will be called. You can then remove some data (if
		1112	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		1113	leave the data there if you want to accumulate more (e.g. when only a
		1114	partial message has been received so far).
		1115
		1116	In the more complex case, you want to queue multiple callbacks. In this
		1117	case, AnyEvent::Handle will call the first queued callback each time new
		1118	data arrives (also the first time it is queued) and removes it when it has
		1119	done its job (see C<push_read>, below).
		1120
		1121	This way you can, for example, push three line-reads, followed by reading
		1122	a chunk of data, and AnyEvent::Handle will execute them in order.
		1123
		1124	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1125	the specified number of bytes which give an XML datagram.
		1126
		1127	# in the default state, expect some header bytes
		1128	$handle->on_read (sub {
		1129	# some data is here, now queue the length-header-read (4 octets)
		1130	shift->unshift_read (chunk => 4, sub {
		1131	# header arrived, decode
		1132	my $len = unpack "N", $_[1];
		1133
		1134	# now read the payload
		1135	shift->unshift_read (chunk => $len, sub {
		1136	my $xml = $_[1];
		1137	# handle xml
		1138	});
		1139	});
		1140	});
		1141
		1142	Example 2: Implement a client for a protocol that replies either with "OK"
		1143	and another line or "ERROR" for the first request that is sent, and 64
		1144	bytes for the second request. Due to the availability of a queue, we can
		1145	just pipeline sending both requests and manipulate the queue as necessary
		1146	in the callbacks.
		1147
		1148	When the first callback is called and sees an "OK" response, it will
		1149	C<unshift> another line-read. This line-read will be queued I<before> the
		1150	64-byte chunk callback.
		1151
		1152	# request one, returns either "OK + extra line" or "ERROR"
		1153	$handle->push_write ("request 1\015\012");
		1154
		1155	# we expect "ERROR" or "OK" as response, so push a line read
		1156	$handle->push_read (line => sub {
		1157	# if we got an "OK", we have to _prepend_ another line,
		1158	# so it will be read before the second request reads its 64 bytes
		1159	# which are already in the queue when this callback is called
		1160	# we don't do this in case we got an error
		1161	if ($_[1] eq "OK") {
		1162	$_[0]->unshift_read (line => sub {
		1163	my $response = $_[1];
		1164	...
		1165	});
		1166	}
		1167	});
		1168
		1169	# request two, simply returns 64 octets
		1170	$handle->push_write ("request 2\015\012");
		1171
		1172	# simply read 64 bytes, always
		1173	$handle->push_read (chunk => 64, sub {
		1174	my $response = $_[1];
		1175	...
		1176	});
		1177
		1178	=over 4
		1179
		1180	=cut
262		1181
263	sub _drain_rbuf {	1182	sub _drain_rbuf {
264	my ($self) = @_;	1183	my ($self) = @_;
265		1184
		1185	# avoid recursion
266	return if exists $self->{in_drain};	1186	return if $self->{_skip_drain_rbuf};
267	local $self->{in_drain} = 1;	1187	local $self->{_skip_drain_rbuf} = 1;
268		1188
		1189	while () {
		1190	# we need to use a separate tls read buffer, as we must not receive data while
		1191	# we are draining the buffer, and this can only happen with TLS.
		1192	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1193	if exists $self->{_tls_rbuf};
		1194
269	while (my $len = length $self->{rbuf}) {	1195	my $len = length $self->{rbuf};
270	no strict 'refs';	1196
271	if (@{ $self->{queue} }) {	1197	if (my $cb = shift @{ $self->{_queue} }) {
272	if ($self->{queue}[0]($self)) {	1198	unless ($cb->($self)) {
		1199	# no progress can be made
		1200	# (not enough data and no data forthcoming)
		1201	$self->_error (Errno::EPIPE, 1), return
		1202	if $self->{_eof};
		1203
273	shift @{ $self->{queue} };	1204	unshift @{ $self->{_queue} }, $cb;
274	} elsif ($self->{eof}) {
275	# no progress can be made (not enough data and no data forthcoming)
276	$! = &Errno::EPIPE; return $self->error;
277	} else {
278	return;	1205	last;
279	}	1206	}
280	} elsif ($self->{on_read}) {	1207	} elsif ($self->{on_read}) {
		1208	last unless $len;
		1209
281	$self->{on_read}($self);	1210	$self->{on_read}($self);
282		1211
283	if (	1212	if (
284	$self->{eof} # if no further data will arrive
285	&& $len == length $self->{rbuf} # and no data has been consumed	1213	$len == length $self->{rbuf} # if no data has been consumed
286	&& !@{ $self->{queue} } # and the queue is still empty	1214	&& !@{ $self->{_queue} } # and the queue is still empty
287	&& $self->{on_read} # and we still want to read data	1215	&& $self->{on_read} # but we still have on_read
288	) {	1216	) {
		1217	# no further data will arrive
289	# then no progress can be made	1218	# so no progress can be made
290	$! = &Errno::EPIPE; return $self->error;	1219	$self->_error (Errno::EPIPE, 1), return
		1220	if $self->{_eof};
		1221
		1222	last; # more data might arrive
291	}	1223	}
292	} else {	1224	} else {
293	# read side becomes idle	1225	# read side becomes idle
294	delete $self->{rw};	1226	delete $self->{_rw} unless $self->{tls};
295	return;	1227	last;
296	}	1228	}
297	}	1229	}
298		1230
299	if ($self->{eof}) {	1231	if ($self->{_eof}) {
300	$self->_shutdown;	1232	$self->{on_eof}
301	$self->{on_eof}($self);	1233	? $self->{on_eof}($self)
		1234	: $self->_error (0, 1, "Unexpected end-of-file");
		1235
		1236	return;
		1237	}
		1238
		1239	if (
		1240	defined $self->{rbuf_max}
		1241	&& $self->{rbuf_max} < length $self->{rbuf}
		1242	) {
		1243	$self->_error (Errno::ENOSPC, 1), return;
		1244	}
		1245
		1246	# may need to restart read watcher
		1247	unless ($self->{_rw}) {
		1248	$self->start_read
		1249	if $self->{on_read} || @{ $self->{_queue} };
302	}	1250	}
303	}	1251	}
304		1252
305	=item $handle->on_read ($cb)	1253	=item $handle->on_read ($cb)
306		1254
307	This replaces the currently set C<on_read> callback, or clears it (when	1255	This replaces the currently set C<on_read> callback, or clears it (when
308	the new callback is C<undef>). See the description of C<on_read> in the	1256	the new callback is C<undef>). See the description of C<on_read> in the
309	constructor.	1257	constructor.
310		1258
		1259	This method may invoke callbacks (and therefore the handle might be
		1260	destroyed after it returns).
		1261
311	=cut	1262	=cut
312		1263
313	sub on_read {	1264	sub on_read {
314	my ($self, $cb) = @_;	1265	my ($self, $cb) = @_;
315		1266
316	$self->{on_read} = $cb;	1267	$self->{on_read} = $cb;
317
318	unless ($self->{rw} || $self->{eof}) {
319	Scalar::Util::weaken $self;
320
321	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
322	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};
323
324	if ($len > 0) {
325	if (exists $self->{rbuf_max}) {
326	if ($self->{rbuf_max} < length $self->{rbuf}) {
327	$! = &Errno::ENOSPC; return $self->error;
328	}
329	}
330
331	} elsif (defined $len) {
332	$self->{eof} = 1;
333	delete $self->{rw};
334
335	} elsif ($! != EAGAIN && $! != EINTR) {
336	return $self->error;
337	}
338
339	$self->_drain_rbuf;	1268	$self->_drain_rbuf if $cb;
340	});
341	}
342	}	1269	}
343		1270
344	=item $handle->rbuf	1271	=item $handle->rbuf
345		1272
346	Returns the read buffer (as a modifiable lvalue).	1273	Returns the read buffer (as a modifiable lvalue).
347		1274
348	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1275	You can access the read buffer directly as the C<< ->{rbuf} >>
349	you want.	1276	member, if you want. However, the only operation allowed on the
		1277	read buffer (apart from looking at it) is removing data from its
		1278	beginning. Otherwise modifying or appending to it is not allowed and will
		1279	lead to hard-to-track-down bugs.
350		1280
351	NOTE: The read buffer should only be used or modified if the C<on_read>,	1281	NOTE: The read buffer should only be used or modified if the C<on_read>,
352	C<push_read> or C<unshift_read> methods are used. The other read methods	1282	C<push_read> or C<unshift_read> methods are used. The other read methods
353	automatically manage the read buffer.	1283	automatically manage the read buffer.
354		1284
…		…
365	Append the given callback to the end of the queue (C<push_read>) or	1295	Append the given callback to the end of the queue (C<push_read>) or
366	prepend it (C<unshift_read>).	1296	prepend it (C<unshift_read>).
367		1297
368	The callback is called each time some additional read data arrives.	1298	The callback is called each time some additional read data arrives.
369		1299
370	It must check wether enough data is in the read buffer already.	1300	It must check whether enough data is in the read buffer already.
371		1301
372	If not enough data is available, it must return the empty list or a false	1302	If not enough data is available, it must return the empty list or a false
373	value, in which case it will be called repeatedly until enough data is	1303	value, in which case it will be called repeatedly until enough data is
374	available (or an error condition is detected).	1304	available (or an error condition is detected).
375		1305
376	If enough data was available, then the callback must remove all data it is	1306	If enough data was available, then the callback must remove all data it is
377	interested in (which can be none at all) and return a true value. After returning	1307	interested in (which can be none at all) and return a true value. After returning
378	true, it will be removed from the queue.	1308	true, it will be removed from the queue.
379		1309
		1310	These methods may invoke callbacks (and therefore the handle might be
		1311	destroyed after it returns).
		1312
380	=cut	1313	=cut
		1314
		1315	our %RH;
		1316
		1317	sub register_read_type($$) {
		1318	$RH{$_[0]} = $_[1];
		1319	}
381		1320
382	sub push_read {	1321	sub push_read {
383	my ($self, $cb) = @_;	1322	my $self = shift;
		1323	my $cb = pop;
384		1324
		1325	if (@_) {
		1326	my $type = shift;
		1327
		1328	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1329	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1330	->($self, $cb, @_);
		1331	}
		1332
385	push @{ $self->{queue} }, $cb;	1333	push @{ $self->{_queue} }, $cb;
386	$self->_drain_rbuf;	1334	$self->_drain_rbuf;
387	}	1335	}
388		1336
389	sub unshift_read {	1337	sub unshift_read {
390	my ($self, $cb) = @_;	1338	my $self = shift;
		1339	my $cb = pop;
391		1340
		1341	if (@_) {
		1342	my $type = shift;
		1343
		1344	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1345	->($self, $cb, @_);
		1346	}
		1347
392	push @{ $self->{queue} }, $cb;	1348	unshift @{ $self->{_queue} }, $cb;
393	$self->_drain_rbuf;	1349	$self->_drain_rbuf;
394	}	1350	}
395		1351
396	=item $handle->push_read_chunk ($len, $cb->($self, $data))	1352	=item $handle->push_read (type => @args, $cb)
397		1353
398	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	1354	=item $handle->unshift_read (type => @args, $cb)
399		1355
400	Append the given callback to the end of the queue (C<push_read_chunk>) or	1356	Instead of providing a callback that parses the data itself you can chose
401	prepend it (C<unshift_read_chunk>).	1357	between a number of predefined parsing formats, for chunks of data, lines
		1358	etc. You can also specify the (fully qualified) name of a package, in
		1359	which case AnyEvent tries to load the package and then expects to find the
		1360	C<anyevent_read_type> function inside (see "custom read types", below).
402		1361
403	The callback will be called only once C<$len> bytes have been read, and	1362	Predefined types are (if you have ideas for additional types, feel free to
404	these C<$len> bytes will be passed to the callback.	1363	drop by and tell us):
405		1364
406	=cut	1365	=over 4
407		1366
408	sub _read_chunk($$) {	1367	=item chunk => $octets, $cb->($handle, $data)
409	my ($len, $cb) = @_;	1368
		1369	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1370	data read to the callback. The callback will never be called with less
		1371	data.
		1372
		1373	Example: read 2 bytes.
		1374
		1375	$handle->push_read (chunk => 2, sub {
		1376	warn "yay ", unpack "H*", $_[1];
		1377	});
		1378
		1379	=cut
		1380
		1381	register_read_type chunk => sub {
		1382	my ($self, $cb, $len) = @_;
410		1383
411	sub {	1384	sub {
412	$len <= length $_[0]{rbuf} or return;	1385	$len <= length $_[0]{rbuf} or return;
413	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1386	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
414	1	1387	1
415	}	1388	}
416	}	1389	};
417		1390
418	sub push_read_chunk {	1391	=item line => [$eol, ]$cb->($handle, $line, $eol)
419	my ($self, $len, $cb) = @_;
420
421	$self->push_read (_read_chunk $len, $cb);
422	}
423
424
425	sub unshift_read_chunk {
426	my ($self, $len, $cb) = @_;
427
428	$self->unshift_read (_read_chunk $len, $cb);
429	}
430
431	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
432
433	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
434
435	Append the given callback to the end of the queue (C<push_read_line>) or
436	prepend it (C<unshift_read_line>).
437		1392
438	The callback will be called only once a full line (including the end of	1393	The callback will be called only once a full line (including the end of
439	line marker, C<$eol>) has been read. This line (excluding the end of line	1394	line marker, C<$eol>) has been read. This line (excluding the end of line
440	marker) will be passed to the callback as second argument (C<$line>), and	1395	marker) will be passed to the callback as second argument (C<$line>), and
441	the end of line marker as the third argument (C<$eol>).	1396	the end of line marker as the third argument (C<$eol>).
…		…
452	Partial lines at the end of the stream will never be returned, as they are	1407	Partial lines at the end of the stream will never be returned, as they are
453	not marked by the end of line marker.	1408	not marked by the end of line marker.
454		1409
455	=cut	1410	=cut
456		1411
457	sub _read_line($$) {	1412	register_read_type line => sub {
458	my $cb = pop;	1413	my ($self, $cb, $eol) = @_;
459	my $eol = @_ ? shift : qr|(\015?\012)|;
460	my $pos;
461		1414
		1415	if (@_ < 3) {
		1416	# this is more than twice as fast as the generic code below
		1417	sub {
		1418	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1419
		1420	$cb->($_[0], $1, $2);
		1421	1
		1422	}
		1423	} else {
462	$eol = qr|(\Q$eol\E)| unless ref $eol;	1424	$eol = quotemeta $eol unless ref $eol;
463	$eol = qr|^(.*?)($eol)|;	1425	$eol = qr|^(.*?)($eol)|s;
		1426
		1427	sub {
		1428	$_[0]{rbuf} =~ s/$eol// or return;
		1429
		1430	$cb->($_[0], $1, $2);
		1431	1
		1432	}
		1433	}
		1434	};
		1435
		1436	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1437
		1438	Makes a regex match against the regex object C<$accept> and returns
		1439	everything up to and including the match.
		1440
		1441	Example: read a single line terminated by '\n'.
		1442
		1443	$handle->push_read (regex => qr<\n>, sub { ... });
		1444
		1445	If C<$reject> is given and not undef, then it determines when the data is
		1446	to be rejected: it is matched against the data when the C<$accept> regex
		1447	does not match and generates an C<EBADMSG> error when it matches. This is
		1448	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1449	receive buffer overflow).
		1450
		1451	Example: expect a single decimal number followed by whitespace, reject
		1452	anything else (not the use of an anchor).
		1453
		1454	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1455
		1456	If C<$skip> is given and not C<undef>, then it will be matched against
		1457	the receive buffer when neither C<$accept> nor C<$reject> match,
		1458	and everything preceding and including the match will be accepted
		1459	unconditionally. This is useful to skip large amounts of data that you
		1460	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1461	have to start matching from the beginning. This is purely an optimisation
		1462	and is usually worth only when you expect more than a few kilobytes.
		1463
		1464	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1465	expect the header to be very large (it isn't in practise, but...), we use
		1466	a skip regex to skip initial portions. The skip regex is tricky in that
		1467	it only accepts something not ending in either \015 or \012, as these are
		1468	required for the accept regex.
		1469
		1470	$handle->push_read (regex =>
		1471	qr<\015\012\015\012>,
		1472	undef, # no reject
		1473	qr<^.*[^\015\012]>,
		1474	sub { ... });
		1475
		1476	=cut
		1477
		1478	register_read_type regex => sub {
		1479	my ($self, $cb, $accept, $reject, $skip) = @_;
		1480
		1481	my $data;
		1482	my $rbuf = \$self->{rbuf};
464		1483
465	sub {	1484	sub {
466	$_[0]{rbuf} =~ s/$eol// or return;	1485	# accept
		1486	if ($$rbuf =~ $accept) {
		1487	$data .= substr $$rbuf, 0, $+[0], "";
		1488	$cb->($self, $data);
		1489	return 1;
		1490	}
		1491
		1492	# reject
		1493	if ($reject && $$rbuf =~ $reject) {
		1494	$self->_error (Errno::EBADMSG);
		1495	}
467		1496
468	$cb->($1, $2);	1497	# skip
		1498	if ($skip && $$rbuf =~ $skip) {
		1499	$data .= substr $$rbuf, 0, $+[0], "";
		1500	}
		1501
		1502	()
		1503	}
		1504	};
		1505
		1506	=item netstring => $cb->($handle, $string)
		1507
		1508	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1509
		1510	Throws an error with C<$!> set to EBADMSG on format violations.
		1511
		1512	=cut
		1513
		1514	register_read_type netstring => sub {
		1515	my ($self, $cb) = @_;
		1516
		1517	sub {
		1518	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1519	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1520	$self->_error (Errno::EBADMSG);
		1521	}
		1522	return;
		1523	}
		1524
		1525	my $len = $1;
		1526
		1527	$self->unshift_read (chunk => $len, sub {
		1528	my $string = $_[1];
		1529	$_[0]->unshift_read (chunk => 1, sub {
		1530	if ($_[1] eq ",") {
		1531	$cb->($_[0], $string);
		1532	} else {
		1533	$self->_error (Errno::EBADMSG);
		1534	}
		1535	});
		1536	});
		1537
469	1	1538	1
470	}	1539	}
471	}	1540	};
472		1541
473	sub push_read_line {	1542	=item packstring => $format, $cb->($handle, $string)
474	my $self = shift;
475		1543
476	$self->push_read (&_read_line);	1544	An octet string prefixed with an encoded length. The encoding C<$format>
477	}	1545	uses the same format as a Perl C<pack> format, but must specify a single
		1546	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1547	optional C<!>, C<< < >> or C<< > >> modifier).
478		1548
479	sub unshift_read_line {	1549	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
480	my $self = shift;	1550	EPP uses a prefix of C<N> (4 octtes).
481		1551
482	$self->unshift_read (&_read_line);	1552	Example: read a block of data prefixed by its length in BER-encoded
483	}	1553	format (very efficient).
		1554
		1555	$handle->push_read (packstring => "w", sub {
		1556	my ($handle, $data) = @_;
		1557	});
		1558
		1559	=cut
		1560
		1561	register_read_type packstring => sub {
		1562	my ($self, $cb, $format) = @_;
		1563
		1564	sub {
		1565	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1566	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1567	or return;
		1568
		1569	$format = length pack $format, $len;
		1570
		1571	# bypass unshift if we already have the remaining chunk
		1572	if ($format + $len <= length $_[0]{rbuf}) {
		1573	my $data = substr $_[0]{rbuf}, $format, $len;
		1574	substr $_[0]{rbuf}, 0, $format + $len, "";
		1575	$cb->($_[0], $data);
		1576	} else {
		1577	# remove prefix
		1578	substr $_[0]{rbuf}, 0, $format, "";
		1579
		1580	# read remaining chunk
		1581	$_[0]->unshift_read (chunk => $len, $cb);
		1582	}
		1583
		1584	1
		1585	}
		1586	};
		1587
		1588	=item json => $cb->($handle, $hash_or_arrayref)
		1589
		1590	Reads a JSON object or array, decodes it and passes it to the
		1591	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1592
		1593	If a C<json> object was passed to the constructor, then that will be used
		1594	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1595
		1596	This read type uses the incremental parser available with JSON version
		1597	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1598	dependency on your own: this module will load the JSON module, but
		1599	AnyEvent does not depend on it itself.
		1600
		1601	Since JSON texts are fully self-delimiting, the C<json> read and write
		1602	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1603	the C<json> write type description, above, for an actual example.
		1604
		1605	=cut
		1606
		1607	register_read_type json => sub {
		1608	my ($self, $cb) = @_;
		1609
		1610	my $json = $self->{json} ||= json_coder;
		1611
		1612	my $data;
		1613	my $rbuf = \$self->{rbuf};
		1614
		1615	sub {
		1616	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1617
		1618	if ($ref) {
		1619	$self->{rbuf} = $json->incr_text;
		1620	$json->incr_text = "";
		1621	$cb->($self, $ref);
		1622
		1623	1
		1624	} elsif ($@) {
		1625	# error case
		1626	$json->incr_skip;
		1627
		1628	$self->{rbuf} = $json->incr_text;
		1629	$json->incr_text = "";
		1630
		1631	$self->_error (Errno::EBADMSG);
		1632
		1633	()
		1634	} else {
		1635	$self->{rbuf} = "";
		1636
		1637	()
		1638	}
		1639	}
		1640	};
		1641
		1642	=item storable => $cb->($handle, $ref)
		1643
		1644	Deserialises a L<Storable> frozen representation as written by the
		1645	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1646	data).
		1647
		1648	Raises C<EBADMSG> error if the data could not be decoded.
		1649
		1650	=cut
		1651
		1652	register_read_type storable => sub {
		1653	my ($self, $cb) = @_;
		1654
		1655	require Storable;
		1656
		1657	sub {
		1658	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1659	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1660	or return;
		1661
		1662	my $format = length pack "w", $len;
		1663
		1664	# bypass unshift if we already have the remaining chunk
		1665	if ($format + $len <= length $_[0]{rbuf}) {
		1666	my $data = substr $_[0]{rbuf}, $format, $len;
		1667	substr $_[0]{rbuf}, 0, $format + $len, "";
		1668	$cb->($_[0], Storable::thaw ($data));
		1669	} else {
		1670	# remove prefix
		1671	substr $_[0]{rbuf}, 0, $format, "";
		1672
		1673	# read remaining chunk
		1674	$_[0]->unshift_read (chunk => $len, sub {
		1675	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1676	$cb->($_[0], $ref);
		1677	} else {
		1678	$self->_error (Errno::EBADMSG);
		1679	}
		1680	});
		1681	}
		1682
		1683	1
		1684	}
		1685	};
484		1686
485	=back	1687	=back
486		1688
		1689	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1690
		1691	Instead of one of the predefined types, you can also specify the name
		1692	of a package. AnyEvent will try to load the package and then expects to
		1693	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1694	progressively tries to load the parent package until it either finds the
		1695	function (good) or runs out of packages (bad).
		1696
		1697	Whenever this type is used, C<push_read> will invoke the function with the
		1698	handle object, the original callback and the remaining arguments.
		1699
		1700	The function is supposed to return a callback (usually a closure) that
		1701	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1702	mentally treat the function as a "configurable read type to read callback"
		1703	converter.
		1704
		1705	It should invoke the original callback when it is done reading (remember
		1706	to pass C<$handle> as first argument as all other callbacks do that,
		1707	although there is no strict requirement on this).
		1708
		1709	For examples, see the source of this module (F<perldoc -m
		1710	AnyEvent::Handle>, search for C<register_read_type>)).
		1711
		1712	=item $handle->stop_read
		1713
		1714	=item $handle->start_read
		1715
		1716	In rare cases you actually do not want to read anything from the
		1717	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1718	any queued callbacks will be executed then. To start reading again, call
		1719	C<start_read>.
		1720
		1721	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1722	you change the C<on_read> callback or push/unshift a read callback, and it
		1723	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1724	there are any read requests in the queue.
		1725
		1726	These methods will have no effect when in TLS mode (as TLS doesn't support
		1727	half-duplex connections).
		1728
		1729	=cut
		1730
		1731	sub stop_read {
		1732	my ($self) = @_;
		1733
		1734	delete $self->{_rw} unless $self->{tls};
		1735	}
		1736
		1737	sub start_read {
		1738	my ($self) = @_;
		1739
		1740	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		1741	Scalar::Util::weaken $self;
		1742
		1743	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1744	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1745	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1746
		1747	if ($len > 0) {
		1748	$self->{_activity} = $self->{_ractivity} = AE::now;
		1749
		1750	if ($self->{tls}) {
		1751	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1752
		1753	&_dotls ($self);
		1754	} else {
		1755	$self->_drain_rbuf;
		1756	}
		1757
		1758	} elsif (defined $len) {
		1759	delete $self->{_rw};
		1760	$self->{_eof} = 1;
		1761	$self->_drain_rbuf;
		1762
		1763	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1764	return $self->_error ($!, 1);
		1765	}
		1766	};
		1767	}
		1768	}
		1769
		1770	our $ERROR_SYSCALL;
		1771	our $ERROR_WANT_READ;
		1772
		1773	sub _tls_error {
		1774	my ($self, $err) = @_;
		1775
		1776	return $self->_error ($!, 1)
		1777	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1778
		1779	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1780
		1781	# reduce error string to look less scary
		1782	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1783
		1784	if ($self->{_on_starttls}) {
		1785	(delete $self->{_on_starttls})->($self, undef, $err);
		1786	&_freetls;
		1787	} else {
		1788	&_freetls;
		1789	$self->_error (Errno::EPROTO, 1, $err);
		1790	}
		1791	}
		1792
		1793	# poll the write BIO and send the data if applicable
		1794	# also decode read data if possible
		1795	# this is basiclaly our TLS state machine
		1796	# more efficient implementations are possible with openssl,
		1797	# but not with the buggy and incomplete Net::SSLeay.
		1798	sub _dotls {
		1799	my ($self) = @_;
		1800
		1801	my $tmp;
		1802
		1803	if (length $self->{_tls_wbuf}) {
		1804	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1805	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1806	}
		1807
		1808	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1809	return $self->_tls_error ($tmp)
		1810	if $tmp != $ERROR_WANT_READ
		1811	&& ($tmp != $ERROR_SYSCALL || $!);
		1812	}
		1813
		1814	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1815	unless (length $tmp) {
		1816	$self->{_on_starttls}
		1817	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1818	&_freetls;
		1819
		1820	if ($self->{on_stoptls}) {
		1821	$self->{on_stoptls}($self);
		1822	return;
		1823	} else {
		1824	# let's treat SSL-eof as we treat normal EOF
		1825	delete $self->{_rw};
		1826	$self->{_eof} = 1;
		1827	}
		1828	}
		1829
		1830	$self->{_tls_rbuf} .= $tmp;
		1831	$self->_drain_rbuf;
		1832	$self->{tls} or return; # tls session might have gone away in callback
		1833	}
		1834
		1835	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1836	return $self->_tls_error ($tmp)
		1837	if $tmp != $ERROR_WANT_READ
		1838	&& ($tmp != $ERROR_SYSCALL || $!);
		1839
		1840	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1841	$self->{wbuf} .= $tmp;
		1842	$self->_drain_wbuf;
		1843	$self->{tls} or return; # tls session might have gone away in callback
		1844	}
		1845
		1846	$self->{_on_starttls}
		1847	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1848	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1849	}
		1850
		1851	=item $handle->starttls ($tls[, $tls_ctx])
		1852
		1853	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1854	object is created, you can also do that at a later time by calling
		1855	C<starttls>.
		1856
		1857	Starting TLS is currently an asynchronous operation - when you push some
		1858	write data and then call C<< ->starttls >> then TLS negotiation will start
		1859	immediately, after which the queued write data is then sent.
		1860
		1861	The first argument is the same as the C<tls> constructor argument (either
		1862	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1863
		1864	The second argument is the optional C<AnyEvent::TLS> object that is used
		1865	when AnyEvent::Handle has to create its own TLS connection object, or
		1866	a hash reference with C<< key => value >> pairs that will be used to
		1867	construct a new context.
		1868
		1869	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1870	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1871	changed to your liking. Note that the handshake might have already started
		1872	when this function returns.
		1873
		1874	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1875	handshakes on the same stream. Best do not attempt to use the stream after
		1876	stopping TLS.
		1877
		1878	This method may invoke callbacks (and therefore the handle might be
		1879	destroyed after it returns).
		1880
		1881	=cut
		1882
		1883	our %TLS_CACHE; #TODO not yet documented, should we?
		1884
		1885	sub starttls {
		1886	my ($self, $tls, $ctx) = @_;
		1887
		1888	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1889	if $self->{tls};
		1890
		1891	$self->{tls} = $tls;
		1892	$self->{tls_ctx} = $ctx if @_ > 2;
		1893
		1894	return unless $self->{fh};
		1895
		1896	require Net::SSLeay;
		1897
		1898	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1899	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1900
		1901	$tls = delete $self->{tls};
		1902	$ctx = $self->{tls_ctx};
		1903
		1904	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1905
		1906	if ("HASH" eq ref $ctx) {
		1907	require AnyEvent::TLS;
		1908
		1909	if ($ctx->{cache}) {
		1910	my $key = $ctx+0;
		1911	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1912	} else {
		1913	$ctx = new AnyEvent::TLS %$ctx;
		1914	}
		1915	}
		1916
		1917	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1918	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		1919
		1920	# basically, this is deep magic (because SSL_read should have the same issues)
		1921	# but the openssl maintainers basically said: "trust us, it just works".
		1922	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1923	# and mismaintained ssleay-module doesn't even offer them).
		1924	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1925	#
		1926	# in short: this is a mess.
		1927	#
		1928	# note that we do not try to keep the length constant between writes as we are required to do.
		1929	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1930	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1931	# have identity issues in that area.
		1932	# Net::SSLeay::CTX_set_mode ($ssl,
		1933	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1934	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1935	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		1936
		1937	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1938	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1939
		1940	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1941
		1942	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1943
		1944	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1945	if $self->{on_starttls};
		1946
		1947	&_dotls; # need to trigger the initial handshake
		1948	$self->start_read; # make sure we actually do read
		1949	}
		1950
		1951	=item $handle->stoptls
		1952
		1953	Shuts down the SSL connection - this makes a proper EOF handshake by
		1954	sending a close notify to the other side, but since OpenSSL doesn't
		1955	support non-blocking shut downs, it is not guaranteed that you can re-use
		1956	the stream afterwards.
		1957
		1958	This method may invoke callbacks (and therefore the handle might be
		1959	destroyed after it returns).
		1960
		1961	=cut
		1962
		1963	sub stoptls {
		1964	my ($self) = @_;
		1965
		1966	if ($self->{tls} && $self->{fh}) {
		1967	Net::SSLeay::shutdown ($self->{tls});
		1968
		1969	&_dotls;
		1970
		1971	# # we don't give a shit. no, we do, but we can't. no...#d#
		1972	# # we, we... have to use openssl :/#d#
		1973	# &_freetls;#d#
		1974	}
		1975	}
		1976
		1977	sub _freetls {
		1978	my ($self) = @_;
		1979
		1980	return unless $self->{tls};
		1981
		1982	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1983	if $self->{tls} > 0;
		1984
		1985	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1986	}
		1987
		1988	sub DESTROY {
		1989	my ($self) = @_;
		1990
		1991	&_freetls;
		1992
		1993	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1994
		1995	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1996	my $fh = delete $self->{fh};
		1997	my $wbuf = delete $self->{wbuf};
		1998
		1999	my @linger;
		2000
		2001	push @linger, AE::io $fh, 1, sub {
		2002	my $len = syswrite $fh, $wbuf, length $wbuf;
		2003
		2004	if ($len > 0) {
		2005	substr $wbuf, 0, $len, "";
		2006	} else {
		2007	@linger = (); # end
		2008	}
		2009	};
		2010	push @linger, AE::timer $linger, 0, sub {
		2011	@linger = ();
		2012	};
		2013	}
		2014	}
		2015
		2016	=item $handle->destroy
		2017
		2018	Shuts down the handle object as much as possible - this call ensures that
		2019	no further callbacks will be invoked and as many resources as possible
		2020	will be freed. Any method you will call on the handle object after
		2021	destroying it in this way will be silently ignored (and it will return the
		2022	empty list).
		2023
		2024	Normally, you can just "forget" any references to an AnyEvent::Handle
		2025	object and it will simply shut down. This works in fatal error and EOF
		2026	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2027	callback, so when you want to destroy the AnyEvent::Handle object from
		2028	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2029	that case.
		2030
		2031	Destroying the handle object in this way has the advantage that callbacks
		2032	will be removed as well, so if those are the only reference holders (as
		2033	is common), then one doesn't need to do anything special to break any
		2034	reference cycles.
		2035
		2036	The handle might still linger in the background and write out remaining
		2037	data, as specified by the C<linger> option, however.
		2038
		2039	=cut
		2040
		2041	sub destroy {
		2042	my ($self) = @_;
		2043
		2044	$self->DESTROY;
		2045	%$self = ();
		2046	bless $self, "AnyEvent::Handle::destroyed";
		2047	}
		2048
		2049	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2050	#nop
		2051	}
		2052
		2053	=item $handle->destroyed
		2054
		2055	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2056	->destroy >>, true otherwise.
		2057
		2058	Can be useful to decide whether the handle is still valid after some
		2059	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2060	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2061	can destroy the handle, so work can be avoided by checking sometimes:
		2062
		2063	$hdl->starttls ("accept");
		2064	return if $hdl->destroyed;
		2065	$hdl->push_write (...
		2066
		2067	Note that the call to C<push_write> will silently be ignored if the handle
		2068	has been destroyed, so often you can just ignore the possibility of the
		2069	handle being destroyed.
		2070
		2071	=cut
		2072
		2073	sub destroyed { 0 }
		2074	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2075
		2076	=item AnyEvent::Handle::TLS_CTX
		2077
		2078	This function creates and returns the AnyEvent::TLS object used by default
		2079	for TLS mode.
		2080
		2081	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2082
		2083	=cut
		2084
		2085	our $TLS_CTX;
		2086
		2087	sub TLS_CTX() {
		2088	$TLS_CTX ||= do {
		2089	require AnyEvent::TLS;
		2090
		2091	new AnyEvent::TLS
		2092	}
		2093	}
		2094
		2095	=back
		2096
		2097
		2098	=head1 NONFREQUENTLY ASKED QUESTIONS
		2099
		2100	=over 4
		2101
		2102	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2103	still get further invocations!
		2104
		2105	That's because AnyEvent::Handle keeps a reference to itself when handling
		2106	read or write callbacks.
		2107
		2108	It is only safe to "forget" the reference inside EOF or error callbacks,
		2109	from within all other callbacks, you need to explicitly call the C<<
		2110	->destroy >> method.
		2111
		2112	=item I get different callback invocations in TLS mode/Why can't I pause
		2113	reading?
		2114
		2115	Unlike, say, TCP, TLS connections do not consist of two independent
		2116	communication channels, one for each direction. Or put differently. The
		2117	read and write directions are not independent of each other: you cannot
		2118	write data unless you are also prepared to read, and vice versa.
		2119
		2120	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2121	callback invocations when you are not expecting any read data - the reason
		2122	is that AnyEvent::Handle always reads in TLS mode.
		2123
		2124	During the connection, you have to make sure that you always have a
		2125	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2126	connection (or when you no longer want to use it) you can call the
		2127	C<destroy> method.
		2128
		2129	=item How do I read data until the other side closes the connection?
		2130
		2131	If you just want to read your data into a perl scalar, the easiest way
		2132	to achieve this is by setting an C<on_read> callback that does nothing,
		2133	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2134	will be in C<$_[0]{rbuf}>:
		2135
		2136	$handle->on_read (sub { });
		2137	$handle->on_eof (undef);
		2138	$handle->on_error (sub {
		2139	my $data = delete $_[0]{rbuf};
		2140	});
		2141
		2142	The reason to use C<on_error> is that TCP connections, due to latencies
		2143	and packets loss, might get closed quite violently with an error, when in
		2144	fact, all data has been received.
		2145
		2146	It is usually better to use acknowledgements when transferring data,
		2147	to make sure the other side hasn't just died and you got the data
		2148	intact. This is also one reason why so many internet protocols have an
		2149	explicit QUIT command.
		2150
		2151	=item I don't want to destroy the handle too early - how do I wait until
		2152	all data has been written?
		2153
		2154	After writing your last bits of data, set the C<on_drain> callback
		2155	and destroy the handle in there - with the default setting of
		2156	C<low_water_mark> this will be called precisely when all data has been
		2157	written to the socket:
		2158
		2159	$handle->push_write (...);
		2160	$handle->on_drain (sub {
		2161	warn "all data submitted to the kernel\n";
		2162	undef $handle;
		2163	});
		2164
		2165	If you just want to queue some data and then signal EOF to the other side,
		2166	consider using C<< ->push_shutdown >> instead.
		2167
		2168	=item I want to contact a TLS/SSL server, I don't care about security.
		2169
		2170	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2171	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2172	parameter:
		2173
		2174	tcp_connect $host, $port, sub {
		2175	my ($fh) = @_;
		2176
		2177	my $handle = new AnyEvent::Handle
		2178	fh => $fh,
		2179	tls => "connect",
		2180	on_error => sub { ... };
		2181
		2182	$handle->push_write (...);
		2183	};
		2184
		2185	=item I want to contact a TLS/SSL server, I do care about security.
		2186
		2187	Then you should additionally enable certificate verification, including
		2188	peername verification, if the protocol you use supports it (see
		2189	L<AnyEvent::TLS>, C<verify_peername>).
		2190
		2191	E.g. for HTTPS:
		2192
		2193	tcp_connect $host, $port, sub {
		2194	my ($fh) = @_;
		2195
		2196	my $handle = new AnyEvent::Handle
		2197	fh => $fh,
		2198	peername => $host,
		2199	tls => "connect",
		2200	tls_ctx => { verify => 1, verify_peername => "https" },
		2201	...
		2202
		2203	Note that you must specify the hostname you connected to (or whatever
		2204	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2205	peername verification will be done.
		2206
		2207	The above will use the system-dependent default set of trusted CA
		2208	certificates. If you want to check against a specific CA, add the
		2209	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2210
		2211	tls_ctx => {
		2212	verify => 1,
		2213	verify_peername => "https",
		2214	ca_file => "my-ca-cert.pem",
		2215	},
		2216
		2217	=item I want to create a TLS/SSL server, how do I do that?
		2218
		2219	Well, you first need to get a server certificate and key. You have
		2220	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2221	self-signed certificate (cheap. check the search engine of your choice,
		2222	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2223	nice program for that purpose).
		2224
		2225	Then create a file with your private key (in PEM format, see
		2226	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2227	file should then look like this:
		2228
		2229	-----BEGIN RSA PRIVATE KEY-----
		2230	...header data
		2231	... lots of base64'y-stuff
		2232	-----END RSA PRIVATE KEY-----
		2233
		2234	-----BEGIN CERTIFICATE-----
		2235	... lots of base64'y-stuff
		2236	-----END CERTIFICATE-----
		2237
		2238	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2239	specify this file as C<cert_file>:
		2240
		2241	tcp_server undef, $port, sub {
		2242	my ($fh) = @_;
		2243
		2244	my $handle = new AnyEvent::Handle
		2245	fh => $fh,
		2246	tls => "accept",
		2247	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2248	...
		2249
		2250	When you have intermediate CA certificates that your clients might not
		2251	know about, just append them to the C<cert_file>.
		2252
		2253	=back
		2254
		2255
		2256	=head1 SUBCLASSING AnyEvent::Handle
		2257
		2258	In many cases, you might want to subclass AnyEvent::Handle.
		2259
		2260	To make this easier, a given version of AnyEvent::Handle uses these
		2261	conventions:
		2262
		2263	=over 4
		2264
		2265	=item * all constructor arguments become object members.
		2266
		2267	At least initially, when you pass a C<tls>-argument to the constructor it
		2268	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2269	mutated later on (for example C<tls> will hold the TLS connection object).
		2270
		2271	=item * other object member names are prefixed with an C<_>.
		2272
		2273	All object members not explicitly documented (internal use) are prefixed
		2274	with an underscore character, so the remaining non-C<_>-namespace is free
		2275	for use for subclasses.
		2276
		2277	=item * all members not documented here and not prefixed with an underscore
		2278	are free to use in subclasses.
		2279
		2280	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2281	member variables, but thats just life, at least it is documented.
		2282
		2283	=back
		2284
487	=head1 AUTHOR	2285	=head1 AUTHOR
488		2286
489	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2287	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
490		2288
491	=cut	2289	=cut

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