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Revision 1.223 by root, Thu Sep 1 04:07:18 2011 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 file handles 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	AE::log 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, $line) = @_;
		27	AE::log warn => "got line <$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 (you can access that
		120	file handle via C<< $handle->{fh} >>). It could be used to prepare the
		121	file handle with parameters required for the actual connect (as opposed to
		122	settings that can be changed when the connection is already 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, $message)
		155
87	This is the fatal error callback, that is called when, well, a fatal error	156	This is the error callback, which is called when, well, some error
88	occurs, such as not being able to resolve the hostname, failure to connect	157	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	158	connect, or a read error.
90		159
91	The object will not be in a usable state when this callback has been	160	Some errors are fatal (which is indicated by C<$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 access the 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 of each
		253	other, for both read and write (triggered when nothing was read I<OR>
		254	written), just read (triggered when nothing was read), and just write:
		255	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		256	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		257	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		258
		259	Note that timeout processing is active even when you do not have any
		260	outstanding read or write requests: If you plan to keep the connection
		261	idle then you should disable the timeout temporarily or ignore the
		262	timeout in the corresponding C<on_timeout> callback, in which case
		263	AnyEvent::Handle will simply restart the timeout.
		264
		265	Zero (the default) disables the corresponding timeout.
		266
		267	=item on_timeout => $cb->($handle)
		268
		269	=item on_rtimeout => $cb->($handle)
		270
		271	=item on_wtimeout => $cb->($handle)
		272
		273	Called whenever the inactivity timeout passes. If you return from this
		274	callback, then the timeout will be reset as if some activity had happened,
		275	so this condition is not fatal in any way.
120		276
121	=item rbuf_max => <bytes>	277	=item rbuf_max => <bytes>
122		278
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	279	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	280	when the read buffer ever (strictly) exceeds this size. This is useful to
125	avoid denial-of-service attacks.	281	avoid some forms of denial-of-service attacks.
126		282
127	For example, a server accepting connections from untrusted sources should	283	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	284	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	285	(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	286	amount of data without a callback ever being called as long as the line
131	isn't finished).	287	isn't finished).
132		288
		289	=item wbuf_max => <bytes>
		290
		291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		292	when the write buffer ever (strictly) exceeds this size. This is useful to
		293	avoid some forms of denial-of-service attacks.
		294
		295	Although the units of this parameter is bytes, this is the I<raw> number
		296	of bytes not yet accepted by the kernel. This can make a difference when
		297	you e.g. use TLS, as TLS typically makes your write data larger (but it
		298	can also make it smaller due to compression).
		299
		300	As an example of when this limit is useful, take a chat server that sends
		301	chat messages to a client. If the client does not read those in a timely
		302	manner then the send buffer in the server would grow unbounded.
		303
		304	=item autocork => <boolean>
		305
		306	When disabled (the default), C<push_write> will try to immediately
		307	write the data to the handle if possible. This avoids having to register
		308	a write watcher and wait for the next event loop iteration, but can
		309	be inefficient if you write multiple small chunks (on the wire, this
		310	disadvantage is usually avoided by your kernel's nagle algorithm, see
		311	C<no_delay>, but this option can save costly syscalls).
		312
		313	When enabled, writes will always be queued till the next event loop
		314	iteration. This is efficient when you do many small writes per iteration,
		315	but less efficient when you do a single write only per iteration (or when
		316	the write buffer often is full). It also increases write latency.
		317
		318	=item no_delay => <boolean>
		319
		320	When doing small writes on sockets, your operating system kernel might
		321	wait a bit for more data before actually sending it out. This is called
		322	the Nagle algorithm, and usually it is beneficial.
		323
		324	In some situations you want as low a delay as possible, which can be
		325	accomplishd by setting this option to a true value.
		326
		327	The default is your operating system's default behaviour (most likely
		328	enabled). This option explicitly enables or disables it, if possible.
		329
		330	=item keepalive => <boolean>
		331
		332	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		333	normally, TCP connections have no time-out once established, so TCP
		334	connections, once established, can stay alive forever even when the other
		335	side has long gone. TCP keepalives are a cheap way to take down long-lived
		336	TCP connections when the other side becomes unreachable. While the default
		337	is OS-dependent, TCP keepalives usually kick in after around two hours,
		338	and, if the other side doesn't reply, take down the TCP connection some 10
		339	to 15 minutes later.
		340
		341	It is harmless to specify this option for file handles that do not support
		342	keepalives, and enabling it on connections that are potentially long-lived
		343	is usually a good idea.
		344
		345	=item oobinline => <boolean>
		346
		347	BSD majorly fucked up the implementation of TCP urgent data. The result
		348	is that almost no OS implements TCP according to the specs, and every OS
		349	implements it slightly differently.
		350
		351	If you want to handle TCP urgent data, then setting this flag (the default
		352	is enabled) gives you the most portable way of getting urgent data, by
		353	putting it into the stream.
		354
		355	Since BSD emulation of OOB data on top of TCP's urgent data can have
		356	security implications, AnyEvent::Handle sets this flag automatically
		357	unless explicitly specified. Note that setting this flag after
		358	establishing a connection I<may> be a bit too late (data loss could
		359	already have occured on BSD systems), but at least it will protect you
		360	from most attacks.
		361
133	=item read_size => <bytes>	362	=item read_size => <bytes>
134		363
135	The default read block size (the amount of bytes this module will try to read	364	The initial read block size, the number of bytes this module will try
136	on each [loop iteration). Default: C<4096>.	365	to read during each loop iteration. Each handle object will consume
		366	at least this amount of memory for the read buffer as well, so when
		367	handling many connections watch out for memory requirements). See also
		368	C<max_read_size>. Default: C<2048>.
		369
		370	=item max_read_size => <bytes>
		371
		372	The maximum read buffer size used by the dynamic adjustment
		373	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		374	one go it will double C<read_size> up to the maximum given by this
		375	option. Default: C<131072> or C<read_size>, whichever is higher.
137		376
138	=item low_water_mark => <bytes>	377	=item low_water_mark => <bytes>
139		378
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	379	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	380	buffer: If the buffer reaches this size or gets even samller it is
142	considered empty.	381	considered empty.
143		382
		383	Sometimes it can be beneficial (for performance reasons) to add data to
		384	the write buffer before it is fully drained, but this is a rare case, as
		385	the operating system kernel usually buffers data as well, so the default
		386	is good in almost all cases.
		387
		388	=item linger => <seconds>
		389
		390	If this is non-zero (default: C<3600>), the destructor of the
		391	AnyEvent::Handle object will check whether there is still outstanding
		392	write data and will install a watcher that will write this data to the
		393	socket. No errors will be reported (this mostly matches how the operating
		394	system treats outstanding data at socket close time).
		395
		396	This will not work for partial TLS data that could not be encoded
		397	yet. This data will be lost. Calling the C<stoptls> method in time might
		398	help.
		399
		400	=item peername => $string
		401
		402	A string used to identify the remote site - usually the DNS hostname
		403	(I<not> IDN!) used to create the connection, rarely the IP address.
		404
		405	Apart from being useful in error messages, this string is also used in TLS
		406	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		407	verification will be skipped when C<peername> is not specified or is
		408	C<undef>.
		409
144	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	410	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
145		411
146	When this parameter is given, it enables TLS (SSL) mode, that means it	412	When this parameter is given, it enables TLS (SSL) mode, that means
147	will start making tls handshake and will transparently encrypt/decrypt	413	AnyEvent will start a TLS handshake as soon as the connection has been
148	data.	414	established and will transparently encrypt/decrypt data afterwards.
		415
		416	All TLS protocol errors will be signalled as C<EPROTO>, with an
		417	appropriate error message.
149		418
150	TLS mode requires Net::SSLeay to be installed (it will be loaded	419	TLS mode requires Net::SSLeay to be installed (it will be loaded
151	automatically when you try to create a TLS handle).	420	automatically when you try to create a TLS handle): this module doesn't
		421	have a dependency on that module, so if your module requires it, you have
		422	to add the dependency yourself.
152		423
153	For the TLS server side, use C<accept>, and for the TLS client side of a	424	Unlike TCP, TLS has a server and client side: for the TLS server side, use
154	connection, use C<connect> mode.	425	C<accept>, and for the TLS client side of a connection, use C<connect>
		426	mode.
155		427
156	You can also provide your own TLS connection object, but you have	428	You can also provide your own TLS connection object, but you have
157	to make sure that you call either C<Net::SSLeay::set_connect_state>	429	to make sure that you call either C<Net::SSLeay::set_connect_state>
158	or C<Net::SSLeay::set_accept_state> on it before you pass it to	430	or C<Net::SSLeay::set_accept_state> on it before you pass it to
159	AnyEvent::Handle.	431	AnyEvent::Handle. Also, this module will take ownership of this connection
		432	object.
160		433
		434	At some future point, AnyEvent::Handle might switch to another TLS
		435	implementation, then the option to use your own session object will go
		436	away.
		437
		438	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		439	passing in the wrong integer will lead to certain crash. This most often
		440	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		441	segmentation fault.
		442
161	See the C<starttls> method if you need to start TLs negotiation later.	443	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
162		444
163	=item tls_ctx => $ssl_ctx	445	=item tls_ctx => $anyevent_tls
164		446
165	Use the given Net::SSLeay::CTX object to create the new TLS connection	447	Use the given C<AnyEvent::TLS> object to create the new TLS connection
166	(unless a connection object was specified directly). If this parameter is	448	(unless a connection object was specified directly). If this
167	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	449	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		450	C<AnyEvent::Handle::TLS_CTX>.
		451
		452	Instead of an object, you can also specify a hash reference with C<< key
		453	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		454	new TLS context object.
		455
		456	=item on_starttls => $cb->($handle, $success[, $error_message])
		457
		458	This callback will be invoked when the TLS/SSL handshake has finished. If
		459	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		460	(C<on_stoptls> will not be called in this case).
		461
		462	The session in C<< $handle->{tls} >> can still be examined in this
		463	callback, even when the handshake was not successful.
		464
		465	TLS handshake failures will not cause C<on_error> to be invoked when this
		466	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		467
		468	Without this callback, handshake failures lead to C<on_error> being
		469	called as usual.
		470
		471	Note that you cannot just call C<starttls> again in this callback. If you
		472	need to do that, start an zero-second timer instead whose callback can
		473	then call C<< ->starttls >> again.
		474
		475	=item on_stoptls => $cb->($handle)
		476
		477	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		478	set, then it will be invoked after freeing the TLS session. If it is not,
		479	then a TLS shutdown condition will be treated like a normal EOF condition
		480	on the handle.
		481
		482	The session in C<< $handle->{tls} >> can still be examined in this
		483	callback.
		484
		485	This callback will only be called on TLS shutdowns, not when the
		486	underlying handle signals EOF.
		487
		488	=item json => JSON or JSON::XS object
		489
		490	This is the json coder object used by the C<json> read and write types.
		491
		492	If you don't supply it, then AnyEvent::Handle will create and use a
		493	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		494	texts.
		495
		496	Note that you are responsible to depend on the JSON module if you want to
		497	use this functionality, as AnyEvent does not have a dependency itself.
168		498
169	=back	499	=back
170		500
171	=cut	501	=cut
172		502
173	sub new {	503	sub new {
174	my $class = shift;	504	my $class = shift;
175
176	my $self = bless { @_ }, $class;	505	my $self = bless { @_ }, $class;
177		506
178	$self->{fh} or Carp::croak "mandatory argument fh is missing";	507	if ($self->{fh}) {
		508	$self->_start;
		509	return unless $self->{fh}; # could be gone by now
		510
		511	} elsif ($self->{connect}) {
		512	require AnyEvent::Socket;
		513
		514	$self->{peername} = $self->{connect}[0]
		515	unless exists $self->{peername};
		516
		517	$self->{_skip_drain_rbuf} = 1;
		518
		519	{
		520	Scalar::Util::weaken (my $self = $self);
		521
		522	$self->{_connect} =
		523	AnyEvent::Socket::tcp_connect (
		524	$self->{connect}[0],
		525	$self->{connect}[1],
		526	sub {
		527	my ($fh, $host, $port, $retry) = @_;
		528
		529	delete $self->{_connect}; # no longer needed
		530
		531	if ($fh) {
		532	$self->{fh} = $fh;
		533
		534	delete $self->{_skip_drain_rbuf};
		535	$self->_start;
		536
		537	$self->{on_connect}
		538	and $self->{on_connect}($self, $host, $port, sub {
		539	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		540	$self->{_skip_drain_rbuf} = 1;
		541	&$retry;
		542	});
		543
		544	} else {
		545	if ($self->{on_connect_error}) {
		546	$self->{on_connect_error}($self, "$!");
		547	$self->destroy if $self;
		548	} else {
		549	$self->_error ($!, 1);
		550	}
		551	}
		552	},
		553	sub {
		554	local $self->{fh} = $_[0];
		555
		556	$self->{on_prepare}
		557	? $self->{on_prepare}->($self)
		558	: ()
		559	}
		560	);
		561	}
		562
		563	} else {
		564	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		565	}
		566
		567	$self
		568	}
		569
		570	sub _start {
		571	my ($self) = @_;
		572
		573	# too many clueless people try to use udp and similar sockets
		574	# with AnyEvent::Handle, do them a favour.
		575	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		576	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		577	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
179		578
180	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	579	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
181		580
182	if ($self->{tls}) {	581	$self->{_activity} =
183	require Net::SSLeay;	582	$self->{_ractivity} =
		583	$self->{_wactivity} = AE::now;
		584
		585	$self->{read_size} ||= 2048;
		586	$self->{max_read_size} = $self->{read_size}
		587	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		588
		589	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		590	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		591	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		592
		593	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		594	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		595
		596	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		597
184	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	598	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
185	}	599	if $self->{tls};
186		600
187	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
188	$self->on_error (delete $self->{on_error}) if $self->{on_error};
189	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	601	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
190	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
191		602
192	$self->start_read;	603	$self->start_read
		604	if $self->{on_read} || @{ $self->{_queue} };
193		605
194	$self	606	$self->_drain_wbuf;
195	}	607	}
196		608
197	sub _shutdown {
198	my ($self) = @_;
199
200	delete $self->{rw};
201	delete $self->{ww};
202	delete $self->{fh};
203	}
204
205	sub error {	609	sub _error {
206	my ($self) = @_;	610	my ($self, $errno, $fatal, $message) = @_;
207		611
208	{	612	$! = $errno;
209	local $!;	613	$message ||= "$!";
210	$self->_shutdown;
211	}
212		614
213	if ($self->{on_error}) {	615	if ($self->{on_error}) {
214	$self->{on_error}($self);	616	$self->{on_error}($self, $fatal, $message);
215	} else {	617	$self->destroy if $fatal;
		618	} elsif ($self->{fh} || $self->{connect}) {
		619	$self->destroy;
216	die "AnyEvent::Handle uncaught fatal error: $!";	620	Carp::croak "AnyEvent::Handle uncaught error: $message";
217	}	621	}
218	}	622	}
219		623
220	=item $fh = $handle->fh	624	=item $fh = $handle->fh
221		625
222	This method returns the file handle of the L<AnyEvent::Handle> object.	626	This method returns the file handle used to create the L<AnyEvent::Handle> object.
223		627
224	=cut	628	=cut
225		629
226	sub fh { $_[0]->{fh} }	630	sub fh { $_[0]{fh} }
227		631
228	=item $handle->on_error ($cb)	632	=item $handle->on_error ($cb)
229		633
230	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	634	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
231		635
…		…
243		647
244	sub on_eof {	648	sub on_eof {
245	$_[0]{on_eof} = $_[1];	649	$_[0]{on_eof} = $_[1];
246	}	650	}
247		651
		652	=item $handle->on_timeout ($cb)
		653
		654	=item $handle->on_rtimeout ($cb)
		655
		656	=item $handle->on_wtimeout ($cb)
		657
		658	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		659	callback, or disables the callback (but not the timeout) if C<$cb> =
		660	C<undef>. See the C<timeout> constructor argument and method.
		661
		662	=cut
		663
		664	# see below
		665
		666	=item $handle->autocork ($boolean)
		667
		668	Enables or disables the current autocork behaviour (see C<autocork>
		669	constructor argument). Changes will only take effect on the next write.
		670
		671	=cut
		672
		673	sub autocork {
		674	$_[0]{autocork} = $_[1];
		675	}
		676
		677	=item $handle->no_delay ($boolean)
		678
		679	Enables or disables the C<no_delay> setting (see constructor argument of
		680	the same name for details).
		681
		682	=cut
		683
		684	sub no_delay {
		685	$_[0]{no_delay} = $_[1];
		686
		687	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		688	if $_[0]{fh};
		689	}
		690
		691	=item $handle->keepalive ($boolean)
		692
		693	Enables or disables the C<keepalive> setting (see constructor argument of
		694	the same name for details).
		695
		696	=cut
		697
		698	sub keepalive {
		699	$_[0]{keepalive} = $_[1];
		700
		701	eval {
		702	local $SIG{__DIE__};
		703	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		704	if $_[0]{fh};
		705	};
		706	}
		707
		708	=item $handle->oobinline ($boolean)
		709
		710	Enables or disables the C<oobinline> setting (see constructor argument of
		711	the same name for details).
		712
		713	=cut
		714
		715	sub oobinline {
		716	$_[0]{oobinline} = $_[1];
		717
		718	eval {
		719	local $SIG{__DIE__};
		720	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		721	if $_[0]{fh};
		722	};
		723	}
		724
		725	=item $handle->keepalive ($boolean)
		726
		727	Enables or disables the C<keepalive> setting (see constructor argument of
		728	the same name for details).
		729
		730	=cut
		731
		732	sub keepalive {
		733	$_[0]{keepalive} = $_[1];
		734
		735	eval {
		736	local $SIG{__DIE__};
		737	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		738	if $_[0]{fh};
		739	};
		740	}
		741
		742	=item $handle->on_starttls ($cb)
		743
		744	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		745
		746	=cut
		747
		748	sub on_starttls {
		749	$_[0]{on_starttls} = $_[1];
		750	}
		751
		752	=item $handle->on_stoptls ($cb)
		753
		754	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		755
		756	=cut
		757
		758	sub on_stoptls {
		759	$_[0]{on_stoptls} = $_[1];
		760	}
		761
		762	=item $handle->rbuf_max ($max_octets)
		763
		764	Configures the C<rbuf_max> setting (C<undef> disables it).
		765
		766	=item $handle->wbuf_max ($max_octets)
		767
		768	Configures the C<wbuf_max> setting (C<undef> disables it).
		769
		770	=cut
		771
		772	sub rbuf_max {
		773	$_[0]{rbuf_max} = $_[1];
		774	}
		775
		776	sub wbuf_max {
		777	$_[0]{wbuf_max} = $_[1];
		778	}
		779
		780	#############################################################################
		781
		782	=item $handle->timeout ($seconds)
		783
		784	=item $handle->rtimeout ($seconds)
		785
		786	=item $handle->wtimeout ($seconds)
		787
		788	Configures (or disables) the inactivity timeout.
		789
		790	The timeout will be checked instantly, so this method might destroy the
		791	handle before it returns.
		792
		793	=item $handle->timeout_reset
		794
		795	=item $handle->rtimeout_reset
		796
		797	=item $handle->wtimeout_reset
		798
		799	Reset the activity timeout, as if data was received or sent.
		800
		801	These methods are cheap to call.
		802
		803	=cut
		804
		805	for my $dir ("", "r", "w") {
		806	my $timeout = "${dir}timeout";
		807	my $tw = "_${dir}tw";
		808	my $on_timeout = "on_${dir}timeout";
		809	my $activity = "_${dir}activity";
		810	my $cb;
		811
		812	*$on_timeout = sub {
		813	$_[0]{$on_timeout} = $_[1];
		814	};
		815
		816	*$timeout = sub {
		817	my ($self, $new_value) = @_;
		818
		819	$new_value >= 0
		820	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		821
		822	$self->{$timeout} = $new_value;
		823	delete $self->{$tw}; &$cb;
		824	};
		825
		826	*{"${dir}timeout_reset"} = sub {
		827	$_[0]{$activity} = AE::now;
		828	};
		829
		830	# main workhorse:
		831	# reset the timeout watcher, as neccessary
		832	# also check for time-outs
		833	$cb = sub {
		834	my ($self) = @_;
		835
		836	if ($self->{$timeout} && $self->{fh}) {
		837	my $NOW = AE::now;
		838
		839	# when would the timeout trigger?
		840	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		841
		842	# now or in the past already?
		843	if ($after <= 0) {
		844	$self->{$activity} = $NOW;
		845
		846	if ($self->{$on_timeout}) {
		847	$self->{$on_timeout}($self);
		848	} else {
		849	$self->_error (Errno::ETIMEDOUT);
		850	}
		851
		852	# callback could have changed timeout value, optimise
		853	return unless $self->{$timeout};
		854
		855	# calculate new after
		856	$after = $self->{$timeout};
		857	}
		858
		859	Scalar::Util::weaken $self;
		860	return unless $self; # ->error could have destroyed $self
		861
		862	$self->{$tw} ||= AE::timer $after, 0, sub {
		863	delete $self->{$tw};
		864	$cb->($self);
		865	};
		866	} else {
		867	delete $self->{$tw};
		868	}
		869	}
		870	}
		871
248	#############################################################################	872	#############################################################################
249		873
250	=back	874	=back
251		875
252	=head2 WRITE QUEUE	876	=head2 WRITE QUEUE
…		…
265	=item $handle->on_drain ($cb)	889	=item $handle->on_drain ($cb)
266		890
267	Sets the C<on_drain> callback or clears it (see the description of	891	Sets the C<on_drain> callback or clears it (see the description of
268	C<on_drain> in the constructor).	892	C<on_drain> in the constructor).
269		893
		894	This method may invoke callbacks (and therefore the handle might be
		895	destroyed after it returns).
		896
270	=cut	897	=cut
271		898
272	sub on_drain {	899	sub on_drain {
273	my ($self, $cb) = @_;	900	my ($self, $cb) = @_;
274		901
275	$self->{on_drain} = $cb;	902	$self->{on_drain} = $cb;
276		903
277	$cb->($self)	904	$cb->($self)
278	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	905	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
279	}	906	}
280		907
281	=item $handle->push_write ($data)	908	=item $handle->push_write ($data)
282		909
283	Queues the given scalar to be written. You can push as much data as you	910	Queues the given scalar to be written. You can push as much data as
284	want (only limited by the available memory), as C<AnyEvent::Handle>	911	you want (only limited by the available memory and C<wbuf_max>), as
285	buffers it independently of the kernel.	912	C<AnyEvent::Handle> buffers it independently of the kernel.
		913
		914	This method may invoke callbacks (and therefore the handle might be
		915	destroyed after it returns).
286		916
287	=cut	917	=cut
288		918
289	sub _drain_wbuf {	919	sub _drain_wbuf {
290	my ($self) = @_;	920	my ($self) = @_;
291		921
292	unless ($self->{ww}) {	922	if (!$self->{_ww} && length $self->{wbuf}) {
		923
293	Scalar::Util::weaken $self;	924	Scalar::Util::weaken $self;
		925
294	my $cb = sub {	926	my $cb = sub {
295	my $len = syswrite $self->{fh}, $self->{wbuf};	927	my $len = syswrite $self->{fh}, $self->{wbuf};
296		928
297	if ($len > 0) {	929	if (defined $len) {
298	substr $self->{wbuf}, 0, $len, "";	930	substr $self->{wbuf}, 0, $len, "";
299		931
		932	$self->{_activity} = $self->{_wactivity} = AE::now;
		933
300	$self->{on_drain}($self)	934	$self->{on_drain}($self)
301	if $self->{low_water_mark} >= length $self->{wbuf}	935	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
302	&& $self->{on_drain};	936	&& $self->{on_drain};
303		937
304	delete $self->{ww} unless length $self->{wbuf};	938	delete $self->{_ww} unless length $self->{wbuf};
305	} elsif ($! != EAGAIN && $! != EINTR) {	939	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
306	$self->error;	940	$self->_error ($!, 1);
307	}	941	}
308	};	942	};
309		943
310	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	944	# try to write data immediately
		945	$cb->() unless $self->{autocork};
311		946
312	$cb->($self);	947	# if still data left in wbuf, we need to poll
		948	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		949	if length $self->{wbuf};
		950
		951	if (
		952	defined $self->{wbuf_max}
		953	&& $self->{wbuf_max} < length $self->{wbuf}
		954	) {
		955	$self->_error (Errno::ENOSPC, 1), return;
		956	}
313	};	957	};
		958	}
		959
		960	our %WH;
		961
		962	# deprecated
		963	sub register_write_type($$) {
		964	$WH{$_[0]} = $_[1];
314	}	965	}
315		966
316	sub push_write {	967	sub push_write {
317	my $self = shift;	968	my $self = shift;
318		969
		970	if (@_ > 1) {
		971	my $type = shift;
		972
		973	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		974	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		975	->($self, @_);
		976	}
		977
		978	# we downgrade here to avoid hard-to-track-down bugs,
		979	# and diagnose the problem earlier and better.
		980
319	if ($self->{filter_w}) {	981	if ($self->{tls}) {
320	$self->{filter_w}->($self, \$_[0]);	982	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		983	&_dotls ($self) if $self->{fh};
321	} else {	984	} else {
322	$self->{wbuf} .= $_[0];	985	utf8::downgrade $self->{wbuf} .= $_[0];
323	$self->_drain_wbuf;	986	$self->_drain_wbuf if $self->{fh};
324	}	987	}
325	}	988	}
		989
		990	=item $handle->push_write (type => @args)
		991
		992	Instead of formatting your data yourself, you can also let this module
		993	do the job by specifying a type and type-specific arguments. You
		994	can also specify the (fully qualified) name of a package, in which
		995	case AnyEvent tries to load the package and then expects to find the
		996	C<anyevent_write_type> function inside (see "custom write types", below).
		997
		998	Predefined types are (if you have ideas for additional types, feel free to
		999	drop by and tell us):
		1000
		1001	=over 4
		1002
		1003	=item netstring => $string
		1004
		1005	Formats the given value as netstring
		1006	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		1007
		1008	=cut
		1009
		1010	register_write_type netstring => sub {
		1011	my ($self, $string) = @_;
		1012
		1013	(length $string) . ":$string,"
		1014	};
		1015
		1016	=item packstring => $format, $data
		1017
		1018	An octet string prefixed with an encoded length. The encoding C<$format>
		1019	uses the same format as a Perl C<pack> format, but must specify a single
		1020	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1021	optional C<!>, C<< < >> or C<< > >> modifier).
		1022
		1023	=cut
		1024
		1025	register_write_type packstring => sub {
		1026	my ($self, $format, $string) = @_;
		1027
		1028	pack "$format/a*", $string
		1029	};
		1030
		1031	=item json => $array_or_hashref
		1032
		1033	Encodes the given hash or array reference into a JSON object. Unless you
		1034	provide your own JSON object, this means it will be encoded to JSON text
		1035	in UTF-8.
		1036
		1037	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		1038	one end of a handle and read them at the other end without using any
		1039	additional framing.
		1040
		1041	The generated JSON text is guaranteed not to contain any newlines: While
		1042	this module doesn't need delimiters after or between JSON texts to be
		1043	able to read them, many other languages depend on that.
		1044
		1045	A simple RPC protocol that interoperates easily with others is to send
		1046	JSON arrays (or objects, although arrays are usually the better choice as
		1047	they mimic how function argument passing works) and a newline after each
		1048	JSON text:
		1049
		1050	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1051	$handle->push_write ("\012");
		1052
		1053	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1054	rely on the fact that the newline will be skipped as leading whitespace:
		1055
		1056	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1057
		1058	Other languages could read single lines terminated by a newline and pass
		1059	this line into their JSON decoder of choice.
		1060
		1061	=cut
		1062
		1063	sub json_coder() {
		1064	eval { require JSON::XS; JSON::XS->new->utf8 }
		1065	|| do { require JSON; JSON->new->utf8 }
		1066	}
		1067
		1068	register_write_type json => sub {
		1069	my ($self, $ref) = @_;
		1070
		1071	my $json = $self->{json} ||= json_coder;
		1072
		1073	$json->encode ($ref)
		1074	};
		1075
		1076	=item storable => $reference
		1077
		1078	Freezes the given reference using L<Storable> and writes it to the
		1079	handle. Uses the C<nfreeze> format.
		1080
		1081	=cut
		1082
		1083	register_write_type storable => sub {
		1084	my ($self, $ref) = @_;
		1085
		1086	require Storable;
		1087
		1088	pack "w/a*", Storable::nfreeze ($ref)
		1089	};
		1090
		1091	=back
		1092
		1093	=item $handle->push_shutdown
		1094
		1095	Sometimes you know you want to close the socket after writing your data
		1096	before it was actually written. One way to do that is to replace your
		1097	C<on_drain> handler by a callback that shuts down the socket (and set
		1098	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1099	replaces the C<on_drain> callback with:
		1100
		1101	sub { shutdown $_[0]{fh}, 1 }
		1102
		1103	This simply shuts down the write side and signals an EOF condition to the
		1104	the peer.
		1105
		1106	You can rely on the normal read queue and C<on_eof> handling
		1107	afterwards. This is the cleanest way to close a connection.
		1108
		1109	This method may invoke callbacks (and therefore the handle might be
		1110	destroyed after it returns).
		1111
		1112	=cut
		1113
		1114	sub push_shutdown {
		1115	my ($self) = @_;
		1116
		1117	delete $self->{low_water_mark};
		1118	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1119	}
		1120
		1121	=item custom write types - Package::anyevent_write_type $handle, @args
		1122
		1123	Instead of one of the predefined types, you can also specify the name of
		1124	a package. AnyEvent will try to load the package and then expects to find
		1125	a function named C<anyevent_write_type> inside. If it isn't found, it
		1126	progressively tries to load the parent package until it either finds the
		1127	function (good) or runs out of packages (bad).
		1128
		1129	Whenever the given C<type> is used, C<push_write> will the function with
		1130	the handle object and the remaining arguments.
		1131
		1132	The function is supposed to return a single octet string that will be
		1133	appended to the write buffer, so you can mentally treat this function as a
		1134	"arguments to on-the-wire-format" converter.
		1135
		1136	Example: implement a custom write type C<join> that joins the remaining
		1137	arguments using the first one.
		1138
		1139	$handle->push_write (My::Type => " ", 1,2,3);
		1140
		1141	# uses the following package, which can be defined in the "My::Type" or in
		1142	# the "My" modules to be auto-loaded, or just about anywhere when the
		1143	# My::Type::anyevent_write_type is defined before invoking it.
		1144
		1145	package My::Type;
		1146
		1147	sub anyevent_write_type {
		1148	my ($handle, $delim, @args) = @_;
		1149
		1150	join $delim, @args
		1151	}
		1152
		1153	=cut
326		1154
327	#############################################################################	1155	#############################################################################
328		1156
329	=back	1157	=back
330		1158
…		…
337	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1165	ways, the "simple" way, using only C<on_read> and the "complex" way, using
338	a queue.	1166	a queue.
339		1167
340	In the simple case, you just install an C<on_read> callback and whenever	1168	In the simple case, you just install an C<on_read> callback and whenever
341	new data arrives, it will be called. You can then remove some data (if	1169	new data arrives, it will be called. You can then remove some data (if
342	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	1170	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
343	or not.	1171	leave the data there if you want to accumulate more (e.g. when only a
		1172	partial message has been received so far), or change the read queue with
		1173	e.g. C<push_read>.
344		1174
345	In the more complex case, you want to queue multiple callbacks. In this	1175	In the more complex case, you want to queue multiple callbacks. In this
346	case, AnyEvent::Handle will call the first queued callback each time new	1176	case, AnyEvent::Handle will call the first queued callback each time new
347	data arrives and removes it when it has done its job (see C<push_read>,	1177	data arrives (also the first time it is queued) and remove it when it has
348	below).	1178	done its job (see C<push_read>, below).
349		1179
350	This way you can, for example, push three line-reads, followed by reading	1180	This way you can, for example, push three line-reads, followed by reading
351	a chunk of data, and AnyEvent::Handle will execute them in order.	1181	a chunk of data, and AnyEvent::Handle will execute them in order.
352		1182
353	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1183	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
354	the specified number of bytes which give an XML datagram.	1184	the specified number of bytes which give an XML datagram.
355		1185
356	# in the default state, expect some header bytes	1186	# in the default state, expect some header bytes
357	$handle->on_read (sub {	1187	$handle->on_read (sub {
358	# some data is here, now queue the length-header-read (4 octets)	1188	# some data is here, now queue the length-header-read (4 octets)
359	shift->unshift_read_chunk (4, sub {	1189	shift->unshift_read (chunk => 4, sub {
360	# header arrived, decode	1190	# header arrived, decode
361	my $len = unpack "N", $_[1];	1191	my $len = unpack "N", $_[1];
362		1192
363	# now read the payload	1193	# now read the payload
364	shift->unshift_read_chunk ($len, sub {	1194	shift->unshift_read (chunk => $len, sub {
365	my $xml = $_[1];	1195	my $xml = $_[1];
366	# handle xml	1196	# handle xml
367	});	1197	});
368	});	1198	});
369	});	1199	});
370		1200
371	Example 2: Implement a client for a protocol that replies either with	1201	Example 2: Implement a client for a protocol that replies either with "OK"
372	"OK" and another line or "ERROR" for one request, and 64 bytes for the	1202	and another line or "ERROR" for the first request that is sent, and 64
373	second request. Due tot he availability of a full queue, we can just	1203	bytes for the second request. Due to the availability of a queue, we can
374	pipeline sending both requests and manipulate the queue as necessary in	1204	just pipeline sending both requests and manipulate the queue as necessary
375	the callbacks:	1205	in the callbacks.
376		1206
377	# request one	1207	When the first callback is called and sees an "OK" response, it will
		1208	C<unshift> another line-read. This line-read will be queued I<before> the
		1209	64-byte chunk callback.
		1210
		1211	# request one, returns either "OK + extra line" or "ERROR"
378	$handle->push_write ("request 1\015\012");	1212	$handle->push_write ("request 1\015\012");
379		1213
380	# we expect "ERROR" or "OK" as response, so push a line read	1214	# we expect "ERROR" or "OK" as response, so push a line read
381	$handle->push_read_line (sub {	1215	$handle->push_read (line => sub {
382	# if we got an "OK", we have to _prepend_ another line,	1216	# if we got an "OK", we have to _prepend_ another line,
383	# so it will be read before the second request reads its 64 bytes	1217	# so it will be read before the second request reads its 64 bytes
384	# which are already in the queue when this callback is called	1218	# which are already in the queue when this callback is called
385	# we don't do this in case we got an error	1219	# we don't do this in case we got an error
386	if ($_[1] eq "OK") {	1220	if ($_[1] eq "OK") {
387	$_[0]->unshift_read_line (sub {	1221	$_[0]->unshift_read (line => sub {
388	my $response = $_[1];	1222	my $response = $_[1];
389	...	1223	...
390	});	1224	});
391	}	1225	}
392	});	1226	});
393		1227
394	# request two	1228	# request two, simply returns 64 octets
395	$handle->push_write ("request 2\015\012");	1229	$handle->push_write ("request 2\015\012");
396		1230
397	# simply read 64 bytes, always	1231	# simply read 64 bytes, always
398	$handle->push_read_chunk (64, sub {	1232	$handle->push_read (chunk => 64, sub {
399	my $response = $_[1];	1233	my $response = $_[1];
400	...	1234	...
401	});	1235	});
402		1236
403	=over 4	1237	=over 4
404		1238
405	=cut	1239	=cut
406		1240
407	sub _drain_rbuf {	1241	sub _drain_rbuf {
408	my ($self) = @_;	1242	my ($self) = @_;
		1243
		1244	# avoid recursion
		1245	return if $self->{_skip_drain_rbuf};
		1246	local $self->{_skip_drain_rbuf} = 1;
		1247
		1248	while () {
		1249	# we need to use a separate tls read buffer, as we must not receive data while
		1250	# we are draining the buffer, and this can only happen with TLS.
		1251	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1252	if exists $self->{_tls_rbuf};
		1253
		1254	my $len = length $self->{rbuf};
		1255
		1256	if (my $cb = shift @{ $self->{_queue} }) {
		1257	unless ($cb->($self)) {
		1258	# no progress can be made
		1259	# (not enough data and no data forthcoming)
		1260	$self->_error (Errno::EPIPE, 1), return
		1261	if $self->{_eof};
		1262
		1263	unshift @{ $self->{_queue} }, $cb;
		1264	last;
		1265	}
		1266	} elsif ($self->{on_read}) {
		1267	last unless $len;
		1268
		1269	$self->{on_read}($self);
		1270
		1271	if (
		1272	$len == length $self->{rbuf} # if no data has been consumed
		1273	&& !@{ $self->{_queue} } # and the queue is still empty
		1274	&& $self->{on_read} # but we still have on_read
		1275	) {
		1276	# no further data will arrive
		1277	# so no progress can be made
		1278	$self->_error (Errno::EPIPE, 1), return
		1279	if $self->{_eof};
		1280
		1281	last; # more data might arrive
		1282	}
		1283	} else {
		1284	# read side becomes idle
		1285	delete $self->{_rw} unless $self->{tls};
		1286	last;
		1287	}
		1288	}
		1289
		1290	if ($self->{_eof}) {
		1291	$self->{on_eof}
		1292	? $self->{on_eof}($self)
		1293	: $self->_error (0, 1, "Unexpected end-of-file");
		1294
		1295	return;
		1296	}
409		1297
410	if (	1298	if (
411	defined $self->{rbuf_max}	1299	defined $self->{rbuf_max}
412	&& $self->{rbuf_max} < length $self->{rbuf}	1300	&& $self->{rbuf_max} < length $self->{rbuf}
413	) {	1301	) {
414	$! = &Errno::ENOSPC; return $self->error;	1302	$self->_error (Errno::ENOSPC, 1), return;
415	}	1303	}
416		1304
417	return if $self->{in_drain};	1305	# may need to restart read watcher
418	local $self->{in_drain} = 1;	1306	unless ($self->{_rw}) {
419		1307	$self->start_read
420	while (my $len = length $self->{rbuf}) {	1308	if $self->{on_read} || @{ $self->{_queue} };
421	no strict 'refs';
422	if (my $cb = shift @{ $self->{queue} }) {
423	if (!$cb->($self)) {
424	if ($self->{eof}) {
425	# no progress can be made (not enough data and no data forthcoming)
426	$! = &Errno::EPIPE; return $self->error;
427	}
428
429	unshift @{ $self->{queue} }, $cb;
430	return;
431	}
432	} elsif ($self->{on_read}) {
433	$self->{on_read}($self);
434
435	if (
436	$self->{eof} # if no further data will arrive
437	&& $len == length $self->{rbuf} # and no data has been consumed
438	&& !@{ $self->{queue} } # and the queue is still empty
439	&& $self->{on_read} # and we still want to read data
440	) {
441	# then no progress can be made
442	$! = &Errno::EPIPE; return $self->error;
443	}
444	} else {
445	# read side becomes idle
446	delete $self->{rw};
447	return;
448	}
449	}
450
451	if ($self->{eof}) {
452	$self->_shutdown;
453	$self->{on_eof}($self)
454	if $self->{on_eof};
455	}	1309	}
456	}	1310	}
457		1311
458	=item $handle->on_read ($cb)	1312	=item $handle->on_read ($cb)
459		1313
460	This replaces the currently set C<on_read> callback, or clears it (when	1314	This replaces the currently set C<on_read> callback, or clears it (when
461	the new callback is C<undef>). See the description of C<on_read> in the	1315	the new callback is C<undef>). See the description of C<on_read> in the
462	constructor.	1316	constructor.
463		1317
		1318	This method may invoke callbacks (and therefore the handle might be
		1319	destroyed after it returns).
		1320
464	=cut	1321	=cut
465		1322
466	sub on_read {	1323	sub on_read {
467	my ($self, $cb) = @_;	1324	my ($self, $cb) = @_;
468		1325
469	$self->{on_read} = $cb;	1326	$self->{on_read} = $cb;
		1327	$self->_drain_rbuf if $cb;
470	}	1328	}
471		1329
472	=item $handle->rbuf	1330	=item $handle->rbuf
473		1331
474	Returns the read buffer (as a modifiable lvalue).	1332	Returns the read buffer (as a modifiable lvalue). You can also access the
		1333	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1334	much faster, and no less clean).
475		1335
476	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1336	The only operation allowed on the read buffer (apart from looking at it)
477	you want.	1337	is removing data from its beginning. Otherwise modifying or appending to
		1338	it is not allowed and will lead to hard-to-track-down bugs.
478		1339
479	NOTE: The read buffer should only be used or modified if the C<on_read>,	1340	NOTE: The read buffer should only be used or modified in the C<on_read>
480	C<push_read> or C<unshift_read> methods are used. The other read methods	1341	callback or when C<push_read> or C<unshift_read> are used with a single
481	automatically manage the read buffer.	1342	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1343	will manage the read buffer on their own.
482		1344
483	=cut	1345	=cut
484		1346
485	sub rbuf : lvalue {	1347	sub rbuf : lvalue {
486	$_[0]{rbuf}	1348	$_[0]{rbuf}
…		…
503		1365
504	If enough data was available, then the callback must remove all data it is	1366	If enough data was available, then the callback must remove all data it is
505	interested in (which can be none at all) and return a true value. After returning	1367	interested in (which can be none at all) and return a true value. After returning
506	true, it will be removed from the queue.	1368	true, it will be removed from the queue.
507		1369
		1370	These methods may invoke callbacks (and therefore the handle might be
		1371	destroyed after it returns).
		1372
508	=cut	1373	=cut
		1374
		1375	our %RH;
		1376
		1377	sub register_read_type($$) {
		1378	$RH{$_[0]} = $_[1];
		1379	}
509		1380
510	sub push_read {	1381	sub push_read {
511	my ($self, $cb) = @_;	1382	my $self = shift;
		1383	my $cb = pop;
512		1384
		1385	if (@_) {
		1386	my $type = shift;
		1387
		1388	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1389	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1390	->($self, $cb, @_);
		1391	}
		1392
513	push @{ $self->{queue} }, $cb;	1393	push @{ $self->{_queue} }, $cb;
514	$self->_drain_rbuf;	1394	$self->_drain_rbuf;
515	}	1395	}
516		1396
517	sub unshift_read {	1397	sub unshift_read {
518	my ($self, $cb) = @_;	1398	my $self = shift;
		1399	my $cb = pop;
519		1400
		1401	if (@_) {
		1402	my $type = shift;
		1403
		1404	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1405	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
		1406	->($self, $cb, @_);
		1407	}
		1408
520	push @{ $self->{queue} }, $cb;	1409	unshift @{ $self->{_queue} }, $cb;
521	$self->_drain_rbuf;	1410	$self->_drain_rbuf;
522	}	1411	}
523		1412
524	=item $handle->push_read_chunk ($len, $cb->($self, $data))	1413	=item $handle->push_read (type => @args, $cb)
525		1414
526	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	1415	=item $handle->unshift_read (type => @args, $cb)
527		1416
528	Append the given callback to the end of the queue (C<push_read_chunk>) or	1417	Instead of providing a callback that parses the data itself you can chose
529	prepend it (C<unshift_read_chunk>).	1418	between a number of predefined parsing formats, for chunks of data, lines
		1419	etc. You can also specify the (fully qualified) name of a package, in
		1420	which case AnyEvent tries to load the package and then expects to find the
		1421	C<anyevent_read_type> function inside (see "custom read types", below).
530		1422
531	The callback will be called only once C<$len> bytes have been read, and	1423	Predefined types are (if you have ideas for additional types, feel free to
532	these C<$len> bytes will be passed to the callback.	1424	drop by and tell us):
533		1425
534	=cut	1426	=over 4
535		1427
536	sub _read_chunk($$) {	1428	=item chunk => $octets, $cb->($handle, $data)
		1429
		1430	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1431	data read to the callback. The callback will never be called with less
		1432	data.
		1433
		1434	Example: read 2 bytes.
		1435
		1436	$handle->push_read (chunk => 2, sub {
		1437	AE::log debug => "yay " . unpack "H*", $_[1];
		1438	});
		1439
		1440	=cut
		1441
		1442	register_read_type chunk => sub {
537	my ($self, $len, $cb) = @_;	1443	my ($self, $cb, $len) = @_;
538		1444
539	sub {	1445	sub {
540	$len <= length $_[0]{rbuf} or return;	1446	$len <= length $_[0]{rbuf} or return;
541	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1447	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
542	1	1448	1
543	}	1449	}
544	}	1450	};
545		1451
546	sub push_read_chunk {	1452	=item line => [$eol, ]$cb->($handle, $line, $eol)
547	$_[0]->push_read (&_read_chunk);
548	}
549
550
551	sub unshift_read_chunk {
552	$_[0]->unshift_read (&_read_chunk);
553	}
554
555	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
556
557	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
558
559	Append the given callback to the end of the queue (C<push_read_line>) or
560	prepend it (C<unshift_read_line>).
561		1453
562	The callback will be called only once a full line (including the end of	1454	The callback will be called only once a full line (including the end of
563	line marker, C<$eol>) has been read. This line (excluding the end of line	1455	line marker, C<$eol>) has been read. This line (excluding the end of line
564	marker) will be passed to the callback as second argument (C<$line>), and	1456	marker) will be passed to the callback as second argument (C<$line>), and
565	the end of line marker as the third argument (C<$eol>).	1457	the end of line marker as the third argument (C<$eol>).
…		…
576	Partial lines at the end of the stream will never be returned, as they are	1468	Partial lines at the end of the stream will never be returned, as they are
577	not marked by the end of line marker.	1469	not marked by the end of line marker.
578		1470
579	=cut	1471	=cut
580		1472
581	sub _read_line($$) {	1473	register_read_type line => sub {
582	my $self = shift;	1474	my ($self, $cb, $eol) = @_;
583	my $cb = pop;
584	my $eol = @_ ? shift : qr|(\015?\012)|;
585	my $pos;
586		1475
		1476	if (@_ < 3) {
		1477	# this is more than twice as fast as the generic code below
		1478	sub {
		1479	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1480
		1481	$cb->($_[0], $1, $2);
		1482	1
		1483	}
		1484	} else {
587	$eol = quotemeta $eol unless ref $eol;	1485	$eol = quotemeta $eol unless ref $eol;
588	$eol = qr|^(.*?)($eol)|s;	1486	$eol = qr|^(.*?)($eol)|s;
		1487
		1488	sub {
		1489	$_[0]{rbuf} =~ s/$eol// or return;
		1490
		1491	$cb->($_[0], $1, $2);
		1492	1
		1493	}
		1494	}
		1495	};
		1496
		1497	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1498
		1499	Makes a regex match against the regex object C<$accept> and returns
		1500	everything up to and including the match.
		1501
		1502	Example: read a single line terminated by '\n'.
		1503
		1504	$handle->push_read (regex => qr<\n>, sub { ... });
		1505
		1506	If C<$reject> is given and not undef, then it determines when the data is
		1507	to be rejected: it is matched against the data when the C<$accept> regex
		1508	does not match and generates an C<EBADMSG> error when it matches. This is
		1509	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1510	receive buffer overflow).
		1511
		1512	Example: expect a single decimal number followed by whitespace, reject
		1513	anything else (not the use of an anchor).
		1514
		1515	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1516
		1517	If C<$skip> is given and not C<undef>, then it will be matched against
		1518	the receive buffer when neither C<$accept> nor C<$reject> match,
		1519	and everything preceding and including the match will be accepted
		1520	unconditionally. This is useful to skip large amounts of data that you
		1521	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1522	have to start matching from the beginning. This is purely an optimisation
		1523	and is usually worth it only when you expect more than a few kilobytes.
		1524
		1525	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1526	expect the header to be very large (it isn't in practice, but...), we use
		1527	a skip regex to skip initial portions. The skip regex is tricky in that
		1528	it only accepts something not ending in either \015 or \012, as these are
		1529	required for the accept regex.
		1530
		1531	$handle->push_read (regex =>
		1532	qr<\015\012\015\012>,
		1533	undef, # no reject
		1534	qr<^.*[^\015\012]>,
		1535	sub { ... });
		1536
		1537	=cut
		1538
		1539	register_read_type regex => sub {
		1540	my ($self, $cb, $accept, $reject, $skip) = @_;
		1541
		1542	my $data;
		1543	my $rbuf = \$self->{rbuf};
589		1544
590	sub {	1545	sub {
591	$_[0]{rbuf} =~ s/$eol// or return;	1546	# accept
592		1547	if ($$rbuf =~ $accept) {
		1548	$data .= substr $$rbuf, 0, $+[0], "";
593	$cb->($_[0], $1, $2);	1549	$cb->($_[0], $data);
		1550	return 1;
		1551	}
		1552
		1553	# reject
		1554	if ($reject && $$rbuf =~ $reject) {
		1555	$_[0]->_error (Errno::EBADMSG);
		1556	}
		1557
		1558	# skip
		1559	if ($skip && $$rbuf =~ $skip) {
		1560	$data .= substr $$rbuf, 0, $+[0], "";
		1561	}
		1562
		1563	()
		1564	}
		1565	};
		1566
		1567	=item netstring => $cb->($handle, $string)
		1568
		1569	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1570
		1571	Throws an error with C<$!> set to EBADMSG on format violations.
		1572
		1573	=cut
		1574
		1575	register_read_type netstring => sub {
		1576	my ($self, $cb) = @_;
		1577
		1578	sub {
		1579	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1580	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1581	$_[0]->_error (Errno::EBADMSG);
		1582	}
		1583	return;
		1584	}
		1585
		1586	my $len = $1;
		1587
		1588	$_[0]->unshift_read (chunk => $len, sub {
		1589	my $string = $_[1];
		1590	$_[0]->unshift_read (chunk => 1, sub {
		1591	if ($_[1] eq ",") {
		1592	$cb->($_[0], $string);
		1593	} else {
		1594	$_[0]->_error (Errno::EBADMSG);
		1595	}
		1596	});
		1597	});
		1598
594	1	1599	1
595	}	1600	}
596	}	1601	};
597		1602
598	sub push_read_line {	1603	=item packstring => $format, $cb->($handle, $string)
599	$_[0]->push_read (&_read_line);
600	}
601		1604
602	sub unshift_read_line {	1605	An octet string prefixed with an encoded length. The encoding C<$format>
603	$_[0]->unshift_read (&_read_line);	1606	uses the same format as a Perl C<pack> format, but must specify a single
604	}	1607	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1608	optional C<!>, C<< < >> or C<< > >> modifier).
		1609
		1610	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1611	EPP uses a prefix of C<N> (4 octtes).
		1612
		1613	Example: read a block of data prefixed by its length in BER-encoded
		1614	format (very efficient).
		1615
		1616	$handle->push_read (packstring => "w", sub {
		1617	my ($handle, $data) = @_;
		1618	});
		1619
		1620	=cut
		1621
		1622	register_read_type packstring => sub {
		1623	my ($self, $cb, $format) = @_;
		1624
		1625	sub {
		1626	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1627	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1628	or return;
		1629
		1630	$format = length pack $format, $len;
		1631
		1632	# bypass unshift if we already have the remaining chunk
		1633	if ($format + $len <= length $_[0]{rbuf}) {
		1634	my $data = substr $_[0]{rbuf}, $format, $len;
		1635	substr $_[0]{rbuf}, 0, $format + $len, "";
		1636	$cb->($_[0], $data);
		1637	} else {
		1638	# remove prefix
		1639	substr $_[0]{rbuf}, 0, $format, "";
		1640
		1641	# read remaining chunk
		1642	$_[0]->unshift_read (chunk => $len, $cb);
		1643	}
		1644
		1645	1
		1646	}
		1647	};
		1648
		1649	=item json => $cb->($handle, $hash_or_arrayref)
		1650
		1651	Reads a JSON object or array, decodes it and passes it to the
		1652	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1653
		1654	If a C<json> object was passed to the constructor, then that will be used
		1655	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1656
		1657	This read type uses the incremental parser available with JSON version
		1658	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1659	dependency on your own: this module will load the JSON module, but
		1660	AnyEvent does not depend on it itself.
		1661
		1662	Since JSON texts are fully self-delimiting, the C<json> read and write
		1663	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1664	the C<json> write type description, above, for an actual example.
		1665
		1666	=cut
		1667
		1668	register_read_type json => sub {
		1669	my ($self, $cb) = @_;
		1670
		1671	my $json = $self->{json} ||= json_coder;
		1672
		1673	my $data;
		1674	my $rbuf = \$self->{rbuf};
		1675
		1676	sub {
		1677	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
		1678
		1679	if ($ref) {
		1680	$_[0]{rbuf} = $json->incr_text;
		1681	$json->incr_text = "";
		1682	$cb->($_[0], $ref);
		1683
		1684	1
		1685	} elsif ($@) {
		1686	# error case
		1687	$json->incr_skip;
		1688
		1689	$_[0]{rbuf} = $json->incr_text;
		1690	$json->incr_text = "";
		1691
		1692	$_[0]->_error (Errno::EBADMSG);
		1693
		1694	()
		1695	} else {
		1696	$_[0]{rbuf} = "";
		1697
		1698	()
		1699	}
		1700	}
		1701	};
		1702
		1703	=item storable => $cb->($handle, $ref)
		1704
		1705	Deserialises a L<Storable> frozen representation as written by the
		1706	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1707	data).
		1708
		1709	Raises C<EBADMSG> error if the data could not be decoded.
		1710
		1711	=cut
		1712
		1713	register_read_type storable => sub {
		1714	my ($self, $cb) = @_;
		1715
		1716	require Storable;
		1717
		1718	sub {
		1719	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1720	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1721	or return;
		1722
		1723	my $format = length pack "w", $len;
		1724
		1725	# bypass unshift if we already have the remaining chunk
		1726	if ($format + $len <= length $_[0]{rbuf}) {
		1727	my $data = substr $_[0]{rbuf}, $format, $len;
		1728	substr $_[0]{rbuf}, 0, $format + $len, "";
		1729	$cb->($_[0], Storable::thaw ($data));
		1730	} else {
		1731	# remove prefix
		1732	substr $_[0]{rbuf}, 0, $format, "";
		1733
		1734	# read remaining chunk
		1735	$_[0]->unshift_read (chunk => $len, sub {
		1736	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1737	$cb->($_[0], $ref);
		1738	} else {
		1739	$_[0]->_error (Errno::EBADMSG);
		1740	}
		1741	});
		1742	}
		1743
		1744	1
		1745	}
		1746	};
		1747
		1748	=back
		1749
		1750	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1751
		1752	Instead of one of the predefined types, you can also specify the name
		1753	of a package. AnyEvent will try to load the package and then expects to
		1754	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1755	progressively tries to load the parent package until it either finds the
		1756	function (good) or runs out of packages (bad).
		1757
		1758	Whenever this type is used, C<push_read> will invoke the function with the
		1759	handle object, the original callback and the remaining arguments.
		1760
		1761	The function is supposed to return a callback (usually a closure) that
		1762	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1763	mentally treat the function as a "configurable read type to read callback"
		1764	converter.
		1765
		1766	It should invoke the original callback when it is done reading (remember
		1767	to pass C<$handle> as first argument as all other callbacks do that,
		1768	although there is no strict requirement on this).
		1769
		1770	For examples, see the source of this module (F<perldoc -m
		1771	AnyEvent::Handle>, search for C<register_read_type>)).
605		1772
606	=item $handle->stop_read	1773	=item $handle->stop_read
607		1774
608	=item $handle->start_read	1775	=item $handle->start_read
609		1776
610	In rare cases you actually do not want to read anything from the	1777	In rare cases you actually do not want to read anything from the
611	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1778	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
612	any queued callbacks will be executed then. To start reading again, call	1779	any queued callbacks will be executed then. To start reading again, call
613	C<start_read>.	1780	C<start_read>.
614		1781
		1782	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1783	you change the C<on_read> callback or push/unshift a read callback, and it
		1784	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1785	there are any read requests in the queue.
		1786
		1787	In older versions of this module (<= 5.3), these methods had no effect,
		1788	as TLS does not support half-duplex connections. In current versions they
		1789	work as expected, as this behaviour is required to avoid certain resource
		1790	attacks, where the program would be forced to read (and buffer) arbitrary
		1791	amounts of data before being able to send some data. The drawback is that
		1792	some readings of the the SSL/TLS specifications basically require this
		1793	attack to be working, as SSL/TLS implementations might stall sending data
		1794	during a rehandshake.
		1795
		1796	As a guideline, during the initial handshake, you should not stop reading,
		1797	and as a client, it might cause problems, depending on your applciation.
		1798
615	=cut	1799	=cut
616		1800
617	sub stop_read {	1801	sub stop_read {
618	my ($self) = @_;	1802	my ($self) = @_;
619		1803
620	delete $self->{rw};	1804	delete $self->{_rw};
621	}	1805	}
622		1806
623	sub start_read {	1807	sub start_read {
624	my ($self) = @_;	1808	my ($self) = @_;
625		1809
626	unless ($self->{rw} || $self->{eof}) {	1810	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
627	Scalar::Util::weaken $self;	1811	Scalar::Util::weaken $self;
628		1812
629	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1813	$self->{_rw} = AE::io $self->{fh}, 0, sub {
630	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1814	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
631	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1815	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
632		1816
633	if ($len > 0) {	1817	if ($len > 0) {
634	$self->{filter_r}	1818	$self->{_activity} = $self->{_ractivity} = AE::now;
635	? $self->{filter_r}->($self, $rbuf)	1819
		1820	if ($self->{tls}) {
		1821	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1822
		1823	&_dotls ($self);
		1824	} else {
636	: $self->_drain_rbuf;	1825	$self->_drain_rbuf;
		1826	}
		1827
		1828	if ($len == $self->{read_size}) {
		1829	$self->{read_size} *= 2;
		1830	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1831	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1832	}
637		1833
638	} elsif (defined $len) {	1834	} elsif (defined $len) {
639	delete $self->{rw};	1835	delete $self->{_rw};
640	$self->{eof} = 1;	1836	$self->{_eof} = 1;
641	$self->_drain_rbuf;	1837	$self->_drain_rbuf;
642		1838
643	} elsif ($! != EAGAIN && $! != EINTR) {	1839	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
644	return $self->error;	1840	return $self->_error ($!, 1);
645	}	1841	}
646	});	1842	};
647	}	1843	}
648	}	1844	}
649		1845
		1846	our $ERROR_SYSCALL;
		1847	our $ERROR_WANT_READ;
		1848
		1849	sub _tls_error {
		1850	my ($self, $err) = @_;
		1851
		1852	return $self->_error ($!, 1)
		1853	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1854
		1855	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1856
		1857	# reduce error string to look less scary
		1858	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1859
		1860	if ($self->{_on_starttls}) {
		1861	(delete $self->{_on_starttls})->($self, undef, $err);
		1862	&_freetls;
		1863	} else {
		1864	&_freetls;
		1865	$self->_error (Errno::EPROTO, 1, $err);
		1866	}
		1867	}
		1868
		1869	# poll the write BIO and send the data if applicable
		1870	# also decode read data if possible
		1871	# this is basiclaly our TLS state machine
		1872	# more efficient implementations are possible with openssl,
		1873	# but not with the buggy and incomplete Net::SSLeay.
650	sub _dotls {	1874	sub _dotls {
651	my ($self) = @_;	1875	my ($self) = @_;
652		1876
		1877	my $tmp;
		1878
653	if (length $self->{tls_wbuf}) {	1879	if (length $self->{_tls_wbuf}) {
654	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1880	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
655	substr $self->{tls_wbuf}, 0, $len, "";	1881	substr $self->{_tls_wbuf}, 0, $tmp, "";
656	}	1882	}
657	}
658		1883
		1884	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1885	return $self->_tls_error ($tmp)
		1886	if $tmp != $ERROR_WANT_READ
		1887	&& ($tmp != $ERROR_SYSCALL || $!);
		1888	}
		1889
659	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1890	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1891	unless (length $tmp) {
		1892	$self->{_on_starttls}
		1893	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1894	&_freetls;
		1895
		1896	if ($self->{on_stoptls}) {
		1897	$self->{on_stoptls}($self);
		1898	return;
		1899	} else {
		1900	# let's treat SSL-eof as we treat normal EOF
		1901	delete $self->{_rw};
		1902	$self->{_eof} = 1;
		1903	}
		1904	}
		1905
		1906	$self->{_tls_rbuf} .= $tmp;
		1907	$self->_drain_rbuf;
		1908	$self->{tls} or return; # tls session might have gone away in callback
		1909	}
		1910
		1911	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1912	return $self->_tls_error ($tmp)
		1913	if $tmp != $ERROR_WANT_READ
		1914	&& ($tmp != $ERROR_SYSCALL || $!);
		1915
		1916	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
660	$self->{wbuf} .= $buf;	1917	$self->{wbuf} .= $tmp;
661	$self->_drain_wbuf;	1918	$self->_drain_wbuf;
		1919	$self->{tls} or return; # tls session might have gone away in callback
662	}	1920	}
663		1921
664	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {	1922	$self->{_on_starttls}
665	$self->{rbuf} .= $buf;	1923	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
666	$self->_drain_rbuf;	1924	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
667	}
668
669	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
670
671	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
672	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
673	$self->error;
674	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
675	$! = &Errno::EIO;
676	$self->error;
677	}
678
679	# all others are fine for our purposes
680	}
681	}	1925	}
682		1926
683	=item $handle->starttls ($tls[, $tls_ctx])	1927	=item $handle->starttls ($tls[, $tls_ctx])
684		1928
685	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1929	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
686	object is created, you can also do that at a later time by calling	1930	object is created, you can also do that at a later time by calling
687	C<starttls>.	1931	C<starttls>.
688		1932
		1933	Starting TLS is currently an asynchronous operation - when you push some
		1934	write data and then call C<< ->starttls >> then TLS negotiation will start
		1935	immediately, after which the queued write data is then sent.
		1936
689	The first argument is the same as the C<tls> constructor argument (either	1937	The first argument is the same as the C<tls> constructor argument (either
690	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1938	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
691		1939
692	The second argument is the optional C<Net::SSLeay::CTX> object that is	1940	The second argument is the optional C<AnyEvent::TLS> object that is used
693	used when AnyEvent::Handle has to create its own TLS connection object.	1941	when AnyEvent::Handle has to create its own TLS connection object, or
		1942	a hash reference with C<< key => value >> pairs that will be used to
		1943	construct a new context.
694		1944
695	=cut	1945	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1946	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1947	changed to your liking. Note that the handshake might have already started
		1948	when this function returns.
696		1949
697	# TODO: maybe document...	1950	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1951	handshakes on the same stream. It is best to not attempt to use the
		1952	stream after stopping TLS.
		1953
		1954	This method may invoke callbacks (and therefore the handle might be
		1955	destroyed after it returns).
		1956
		1957	=cut
		1958
		1959	our %TLS_CACHE; #TODO not yet documented, should we?
		1960
698	sub starttls {	1961	sub starttls {
699	my ($self, $ssl, $ctx) = @_;	1962	my ($self, $tls, $ctx) = @_;
700		1963
701	$self->stoptls;	1964	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1965	if $self->{tls};
702		1966
703	if ($ssl eq "accept") {	1967	$self->{tls} = $tls;
704	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1968	$self->{tls_ctx} = $ctx if @_ > 2;
705	Net::SSLeay::set_accept_state ($ssl);	1969
706	} elsif ($ssl eq "connect") {	1970	return unless $self->{fh};
707	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1971
708	Net::SSLeay::set_connect_state ($ssl);	1972	require Net::SSLeay;
		1973
		1974	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1975	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1976
		1977	$tls = delete $self->{tls};
		1978	$ctx = $self->{tls_ctx};
		1979
		1980	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1981
		1982	if ("HASH" eq ref $ctx) {
		1983	require AnyEvent::TLS;
		1984
		1985	if ($ctx->{cache}) {
		1986	my $key = $ctx+0;
		1987	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1988	} else {
		1989	$ctx = new AnyEvent::TLS %$ctx;
		1990	}
		1991	}
709	}	1992
710		1993	$self->{tls_ctx} = $ctx || TLS_CTX ();
711	$self->{tls} = $ssl;	1994	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
712		1995
713	# basically, this is deep magic (because SSL_read should have the same issues)	1996	# basically, this is deep magic (because SSL_read should have the same issues)
714	# but the openssl maintainers basically said: "trust us, it just works".	1997	# but the openssl maintainers basically said: "trust us, it just works".
715	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1998	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
716	# and mismaintained ssleay-module doesn't even offer them).	1999	# and mismaintained ssleay-module doesn't even offer them).
717	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	2000	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		2001	#
		2002	# in short: this is a mess.
		2003	#
		2004	# note that we do not try to keep the length constant between writes as we are required to do.
		2005	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		2006	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2007	# have identity issues in that area.
718	Net::SSLeay::CTX_set_mode ($self->{tls},	2008	# Net::SSLeay::CTX_set_mode ($ssl,
719	(eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2009	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
720	| (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2010	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2011	Net::SSLeay::CTX_set_mode ($tls, 1|2);
721		2012
722	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
723	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2014	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
724		2015
		2016	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2017	$self->{rbuf} = "";
		2018
725	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	2019	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
726		2020
727	$self->{filter_w} = sub {	2021	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
728	$_[0]{tls_wbuf} .= ${$_[1]};	2022	if $self->{on_starttls};
729	&_dotls;	2023
730	};	2024	&_dotls; # need to trigger the initial handshake
731	$self->{filter_r} = sub {	2025	$self->start_read; # make sure we actually do read
732	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
733	&_dotls;
734	};
735	}	2026	}
736		2027
737	=item $handle->stoptls	2028	=item $handle->stoptls
738		2029
739	Destroys the SSL connection, if any. Partial read or write data will be	2030	Shuts down the SSL connection - this makes a proper EOF handshake by
740	lost.	2031	sending a close notify to the other side, but since OpenSSL doesn't
		2032	support non-blocking shut downs, it is not guaranteed that you can re-use
		2033	the stream afterwards.
		2034
		2035	This method may invoke callbacks (and therefore the handle might be
		2036	destroyed after it returns).
741		2037
742	=cut	2038	=cut
743		2039
744	sub stoptls {	2040	sub stoptls {
745	my ($self) = @_;	2041	my ($self) = @_;
746		2042
747	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2043	if ($self->{tls} && $self->{fh}) {
748	delete $self->{tls_rbio};	2044	Net::SSLeay::shutdown ($self->{tls});
749	delete $self->{tls_wbio};	2045
750	delete $self->{tls_wbuf};	2046	&_dotls;
751	delete $self->{filter_r};	2047
752	delete $self->{filter_w};	2048	# # we don't give a shit. no, we do, but we can't. no...#d#
		2049	# # we, we... have to use openssl :/#d#
		2050	# &_freetls;#d#
		2051	}
753	}	2052	}
		2053
		2054	sub _freetls {
		2055	my ($self) = @_;
		2056
		2057	return unless $self->{tls};
		2058
		2059	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2060	if $self->{tls} > 0;
		2061
		2062	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2063	}
		2064
		2065	=item $handle->resettls
		2066
		2067	This rarely-used method simply resets and TLS state on the handle, usually
		2068	causing data loss.
		2069
		2070	One case where it may be useful is when you want to skip over the data in
		2071	the stream but you are not interested in interpreting it, so data loss is
		2072	no concern.
		2073
		2074	=cut
		2075
		2076	*resettls = \&_freetls;
754		2077
755	sub DESTROY {	2078	sub DESTROY {
756	my $self = shift;	2079	my ($self) = @_;
757		2080
758	$self->stoptls;	2081	&_freetls;
		2082
		2083	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2084
		2085	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2086	my $fh = delete $self->{fh};
		2087	my $wbuf = delete $self->{wbuf};
		2088
		2089	my @linger;
		2090
		2091	push @linger, AE::io $fh, 1, sub {
		2092	my $len = syswrite $fh, $wbuf, length $wbuf;
		2093
		2094	if ($len > 0) {
		2095	substr $wbuf, 0, $len, "";
		2096	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
		2097	@linger = (); # end
		2098	}
		2099	};
		2100	push @linger, AE::timer $linger, 0, sub {
		2101	@linger = ();
		2102	};
		2103	}
759	}	2104	}
		2105
		2106	=item $handle->destroy
		2107
		2108	Shuts down the handle object as much as possible - this call ensures that
		2109	no further callbacks will be invoked and as many resources as possible
		2110	will be freed. Any method you will call on the handle object after
		2111	destroying it in this way will be silently ignored (and it will return the
		2112	empty list).
		2113
		2114	Normally, you can just "forget" any references to an AnyEvent::Handle
		2115	object and it will simply shut down. This works in fatal error and EOF
		2116	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2117	callback, so when you want to destroy the AnyEvent::Handle object from
		2118	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2119	that case.
		2120
		2121	Destroying the handle object in this way has the advantage that callbacks
		2122	will be removed as well, so if those are the only reference holders (as
		2123	is common), then one doesn't need to do anything special to break any
		2124	reference cycles.
		2125
		2126	The handle might still linger in the background and write out remaining
		2127	data, as specified by the C<linger> option, however.
		2128
		2129	=cut
		2130
		2131	sub destroy {
		2132	my ($self) = @_;
		2133
		2134	$self->DESTROY;
		2135	%$self = ();
		2136	bless $self, "AnyEvent::Handle::destroyed";
		2137	}
		2138
		2139	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2140	#nop
		2141	}
		2142
		2143	=item $handle->destroyed
		2144
		2145	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2146	->destroy >>, true otherwise.
		2147
		2148	Can be useful to decide whether the handle is still valid after some
		2149	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2150	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2151	can destroy the handle, so work can be avoided by checking sometimes:
		2152
		2153	$hdl->starttls ("accept");
		2154	return if $hdl->destroyed;
		2155	$hdl->push_write (...
		2156
		2157	Note that the call to C<push_write> will silently be ignored if the handle
		2158	has been destroyed, so often you can just ignore the possibility of the
		2159	handle being destroyed.
		2160
		2161	=cut
		2162
		2163	sub destroyed { 0 }
		2164	sub AnyEvent::Handle::destroyed::destroyed { 1 }
760		2165
761	=item AnyEvent::Handle::TLS_CTX	2166	=item AnyEvent::Handle::TLS_CTX
762		2167
763	This function creates and returns the Net::SSLeay::CTX object used by	2168	This function creates and returns the AnyEvent::TLS object used by default
764	default for TLS mode.	2169	for TLS mode.
765		2170
766	The context is created like this:	2171	The context is created by calling L<AnyEvent::TLS> without any arguments.
767
768	Net::SSLeay::load_error_strings;
769	Net::SSLeay::SSLeay_add_ssl_algorithms;
770	Net::SSLeay::randomize;
771
772	my $CTX = Net::SSLeay::CTX_new;
773
774	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
775		2172
776	=cut	2173	=cut
777		2174
778	our $TLS_CTX;	2175	our $TLS_CTX;
779		2176
780	sub TLS_CTX() {	2177	sub TLS_CTX() {
781	$TLS_CTX || do {	2178	$TLS_CTX ||= do {
782	require Net::SSLeay;	2179	require AnyEvent::TLS;
783		2180
784	Net::SSLeay::load_error_strings ();	2181	new AnyEvent::TLS
785	Net::SSLeay::SSLeay_add_ssl_algorithms ();
786	Net::SSLeay::randomize ();
787
788	$TLS_CTX = Net::SSLeay::CTX_new ();
789
790	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
791
792	$TLS_CTX
793	}	2182	}
794	}	2183	}
795		2184
796	=back	2185	=back
797		2186
		2187
		2188	=head1 NONFREQUENTLY ASKED QUESTIONS
		2189
		2190	=over 4
		2191
		2192	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2193	still get further invocations!
		2194
		2195	That's because AnyEvent::Handle keeps a reference to itself when handling
		2196	read or write callbacks.
		2197
		2198	It is only safe to "forget" the reference inside EOF or error callbacks,
		2199	from within all other callbacks, you need to explicitly call the C<<
		2200	->destroy >> method.
		2201
		2202	=item Why is my C<on_eof> callback never called?
		2203
		2204	Probably because your C<on_error> callback is being called instead: When
		2205	you have outstanding requests in your read queue, then an EOF is
		2206	considered an error as you clearly expected some data.
		2207
		2208	To avoid this, make sure you have an empty read queue whenever your handle
		2209	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2210	an C<on_read> handler that simply pushes the first read requests in the
		2211	queue.
		2212
		2213	See also the next question, which explains this in a bit more detail.
		2214
		2215	=item How can I serve requests in a loop?
		2216
		2217	Most protocols consist of some setup phase (authentication for example)
		2218	followed by a request handling phase, where the server waits for requests
		2219	and handles them, in a loop.
		2220
		2221	There are two important variants: The first (traditional, better) variant
		2222	handles requests until the server gets some QUIT command, causing it to
		2223	close the connection first (highly desirable for a busy TCP server). A
		2224	client dropping the connection is an error, which means this variant can
		2225	detect an unexpected detection close.
		2226
		2227	To handle this case, always make sure you have a on-empty read queue, by
		2228	pushing the "read request start" handler on it:
		2229
		2230	# we assume a request starts with a single line
		2231	my @start_request; @start_request = (line => sub {
		2232	my ($hdl, $line) = @_;
		2233
		2234	... handle request
		2235
		2236	# push next request read, possibly from a nested callback
		2237	$hdl->push_read (@start_request);
		2238	});
		2239
		2240	# auth done, now go into request handling loop
		2241	# now push the first @start_request
		2242	$hdl->push_read (@start_request);
		2243
		2244	By always having an outstanding C<push_read>, the handle always expects
		2245	some data and raises the C<EPIPE> error when the connction is dropped
		2246	unexpectedly.
		2247
		2248	The second variant is a protocol where the client can drop the connection
		2249	at any time. For TCP, this means that the server machine may run out of
		2250	sockets easier, and in general, it means you cannot distinguish a protocl
		2251	failure/client crash from a normal connection close. Nevertheless, these
		2252	kinds of protocols are common (and sometimes even the best solution to the
		2253	problem).
		2254
		2255	Having an outstanding read request at all times is possible if you ignore
		2256	C<EPIPE> errors, but this doesn't help with when the client drops the
		2257	connection during a request, which would still be an error.
		2258
		2259	A better solution is to push the initial request read in an C<on_read>
		2260	callback. This avoids an error, as when the server doesn't expect data
		2261	(i.e. is idly waiting for the next request, an EOF will not raise an
		2262	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2263	and simpler:
		2264
		2265	# auth done, now go into request handling loop
		2266	$hdl->on_read (sub {
		2267	my ($hdl) = @_;
		2268
		2269	# called each time we receive data but the read queue is empty
		2270	# simply start read the request
		2271
		2272	$hdl->push_read (line => sub {
		2273	my ($hdl, $line) = @_;
		2274
		2275	... handle request
		2276
		2277	# do nothing special when the request has been handled, just
		2278	# let the request queue go empty.
		2279	});
		2280	});
		2281
		2282	=item I get different callback invocations in TLS mode/Why can't I pause
		2283	reading?
		2284
		2285	Unlike, say, TCP, TLS connections do not consist of two independent
		2286	communication channels, one for each direction. Or put differently, the
		2287	read and write directions are not independent of each other: you cannot
		2288	write data unless you are also prepared to read, and vice versa.
		2289
		2290	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2291	callback invocations when you are not expecting any read data - the reason
		2292	is that AnyEvent::Handle always reads in TLS mode.
		2293
		2294	During the connection, you have to make sure that you always have a
		2295	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2296	connection (or when you no longer want to use it) you can call the
		2297	C<destroy> method.
		2298
		2299	=item How do I read data until the other side closes the connection?
		2300
		2301	If you just want to read your data into a perl scalar, the easiest way
		2302	to achieve this is by setting an C<on_read> callback that does nothing,
		2303	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2304	will be in C<$_[0]{rbuf}>:
		2305
		2306	$handle->on_read (sub { });
		2307	$handle->on_eof (undef);
		2308	$handle->on_error (sub {
		2309	my $data = delete $_[0]{rbuf};
		2310	});
		2311
		2312	Note that this example removes the C<rbuf> member from the handle object,
		2313	which is not normally allowed by the API. It is expressly permitted in
		2314	this case only, as the handle object needs to be destroyed afterwards.
		2315
		2316	The reason to use C<on_error> is that TCP connections, due to latencies
		2317	and packets loss, might get closed quite violently with an error, when in
		2318	fact all data has been received.
		2319
		2320	It is usually better to use acknowledgements when transferring data,
		2321	to make sure the other side hasn't just died and you got the data
		2322	intact. This is also one reason why so many internet protocols have an
		2323	explicit QUIT command.
		2324
		2325	=item I don't want to destroy the handle too early - how do I wait until
		2326	all data has been written?
		2327
		2328	After writing your last bits of data, set the C<on_drain> callback
		2329	and destroy the handle in there - with the default setting of
		2330	C<low_water_mark> this will be called precisely when all data has been
		2331	written to the socket:
		2332
		2333	$handle->push_write (...);
		2334	$handle->on_drain (sub {
		2335	AE::log debug => "all data submitted to the kernel\n";
		2336	undef $handle;
		2337	});
		2338
		2339	If you just want to queue some data and then signal EOF to the other side,
		2340	consider using C<< ->push_shutdown >> instead.
		2341
		2342	=item I want to contact a TLS/SSL server, I don't care about security.
		2343
		2344	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2345	connect to it and then create the AnyEvent::Handle with the C<tls>
		2346	parameter:
		2347
		2348	tcp_connect $host, $port, sub {
		2349	my ($fh) = @_;
		2350
		2351	my $handle = new AnyEvent::Handle
		2352	fh => $fh,
		2353	tls => "connect",
		2354	on_error => sub { ... };
		2355
		2356	$handle->push_write (...);
		2357	};
		2358
		2359	=item I want to contact a TLS/SSL server, I do care about security.
		2360
		2361	Then you should additionally enable certificate verification, including
		2362	peername verification, if the protocol you use supports it (see
		2363	L<AnyEvent::TLS>, C<verify_peername>).
		2364
		2365	E.g. for HTTPS:
		2366
		2367	tcp_connect $host, $port, sub {
		2368	my ($fh) = @_;
		2369
		2370	my $handle = new AnyEvent::Handle
		2371	fh => $fh,
		2372	peername => $host,
		2373	tls => "connect",
		2374	tls_ctx => { verify => 1, verify_peername => "https" },
		2375	...
		2376
		2377	Note that you must specify the hostname you connected to (or whatever
		2378	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2379	peername verification will be done.
		2380
		2381	The above will use the system-dependent default set of trusted CA
		2382	certificates. If you want to check against a specific CA, add the
		2383	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2384
		2385	tls_ctx => {
		2386	verify => 1,
		2387	verify_peername => "https",
		2388	ca_file => "my-ca-cert.pem",
		2389	},
		2390
		2391	=item I want to create a TLS/SSL server, how do I do that?
		2392
		2393	Well, you first need to get a server certificate and key. You have
		2394	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2395	self-signed certificate (cheap. check the search engine of your choice,
		2396	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2397	nice program for that purpose).
		2398
		2399	Then create a file with your private key (in PEM format, see
		2400	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2401	file should then look like this:
		2402
		2403	-----BEGIN RSA PRIVATE KEY-----
		2404	...header data
		2405	... lots of base64'y-stuff
		2406	-----END RSA PRIVATE KEY-----
		2407
		2408	-----BEGIN CERTIFICATE-----
		2409	... lots of base64'y-stuff
		2410	-----END CERTIFICATE-----
		2411
		2412	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2413	specify this file as C<cert_file>:
		2414
		2415	tcp_server undef, $port, sub {
		2416	my ($fh) = @_;
		2417
		2418	my $handle = new AnyEvent::Handle
		2419	fh => $fh,
		2420	tls => "accept",
		2421	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2422	...
		2423
		2424	When you have intermediate CA certificates that your clients might not
		2425	know about, just append them to the C<cert_file>.
		2426
		2427	=back
		2428
		2429
		2430	=head1 SUBCLASSING AnyEvent::Handle
		2431
		2432	In many cases, you might want to subclass AnyEvent::Handle.
		2433
		2434	To make this easier, a given version of AnyEvent::Handle uses these
		2435	conventions:
		2436
		2437	=over 4
		2438
		2439	=item * all constructor arguments become object members.
		2440
		2441	At least initially, when you pass a C<tls>-argument to the constructor it
		2442	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2443	mutated later on (for example C<tls> will hold the TLS connection object).
		2444
		2445	=item * other object member names are prefixed with an C<_>.
		2446
		2447	All object members not explicitly documented (internal use) are prefixed
		2448	with an underscore character, so the remaining non-C<_>-namespace is free
		2449	for use for subclasses.
		2450
		2451	=item * all members not documented here and not prefixed with an underscore
		2452	are free to use in subclasses.
		2453
		2454	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2455	member variables, but that's just life. At least it is documented.
		2456
		2457	=back
		2458
798	=head1 AUTHOR	2459	=head1 AUTHOR
799		2460
800	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2461	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
801		2462
802	=cut	2463	=cut

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