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Revision 1.237 by root, Tue Jul 30 23:14:32 2013 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	=cut
18
19	our $VERSION = '0.04';
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $handle =	12	my $hdl; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
32	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
33	},	16	AE::log error => $msg;
		17	$hdl->destroy;
		18	$cv->send;
34	);	19	};
35		20
36	# send some request line	21	# send some request line
37	$handle->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
38		23
39	# read the response line	24	# read the response line
40	$handle->push_read (line => sub {	25	$hdl->push_read (line => sub {
41	my ($handle, $line) = @_;	26	my ($hdl, $line) = @_;
42	warn "read line <$line>\n";	27	say "got line <$line>";
43	$cv->send;	28	$cv->send;
44	});	29	});
45		30
46	$cv->recv;	31	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	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
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
54	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
55	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
56	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.
57		47
58	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
59	argument.	49	argument.
60		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
61	=head1 METHODS	82	=head1 METHODS
62		83
63	=over 4	84	=over 4
64		85
65	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66		87
67	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
68		89
69	=over 4	90	=over 4
70		91
71	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72		93
73	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
74
75	NOTE: The filehandle will be set to non-blocking (using	95	NOTE: The filehandle will be set to non-blocking mode (using
76	AnyEvent::Util::fh_nonblocking).	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
77		98
78	=item on_eof => $cb->($self)	99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
79		100
80	Set the callback to be called on EOF.	101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
81		104
82	While not mandatory, it is highly recommended to set an eof callback,	105	You have to specify either this parameter, or C<fh>, above.
83	otherwise you might end up with a closed socket while you are still
84	waiting for data.
85		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
86	=item on_error => $cb->($self)	116	=item on_prepare => $cb->($handle)
87		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, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback. At the time it is called the
		134	read and write queues, EOF status, TLS status and similar properties of
		135	the handle will have been reset.
		136
		137	It is not allowed to use the read or write queues while the handle object
		138	is connecting.
		139
		140	If, for some reason, the handle is not acceptable, calling C<$retry> will
		141	continue with the next connection target (in case of multi-homed hosts or
		142	SRV records there can be multiple connection endpoints). The C<$retry>
		143	callback can be invoked after the connect callback returns, i.e. one can
		144	start a handshake and then decide to retry with the next host if the
		145	handshake fails.
		146
		147	In most cases, you should ignore the C<$retry> parameter.
		148
		149	=item on_connect_error => $cb->($handle, $message)
		150
		151	This callback is called when the connection could not be
		152	established. C<$!> will contain the relevant error code, and C<$message> a
		153	message describing it (usually the same as C<"$!">).
		154
		155	If this callback isn't specified, then C<on_error> will be called with a
		156	fatal error instead.
		157
		158	=back
		159
		160	=item on_error => $cb->($handle, $fatal, $message)
		161
88	This is the fatal error callback, that is called when, well, a fatal error	162	This is the error callback, which is called when, well, some error
89	occurs, such as not being able to resolve the hostname, failure to connect	163	occured, such as not being able to resolve the hostname, failure to
90	or a read error.	164	connect, or a read error.
91		165
92	The object will not be in a usable state when this callback has been	166	Some errors are fatal (which is indicated by C<$fatal> being true). On
93	called.	167	fatal errors the handle object will be destroyed (by a call to C<< ->
		168	destroy >>) after invoking the error callback (which means you are free to
		169	examine the handle object). Examples of fatal errors are an EOF condition
		170	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		171	cases where the other side can close the connection at will, it is
		172	often easiest to not report C<EPIPE> errors in this callback.
94		173
		174	AnyEvent::Handle tries to find an appropriate error code for you to check
		175	against, but in some cases (TLS errors), this does not work well.
		176
		177	If you report the error to the user, it is recommended to always output
		178	the C<$message> argument in human-readable error messages (you don't need
		179	to report C<"$!"> if you report C<$message>).
		180
		181	If you want to react programmatically to the error, then looking at C<$!>
		182	and comparing it against some of the documented C<Errno> values is usually
		183	better than looking at the C<$message>.
		184
		185	Non-fatal errors can be retried by returning, but it is recommended
		186	to simply ignore this parameter and instead abondon the handle object
		187	when this callback is invoked. Examples of non-fatal errors are timeouts
		188	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		189
95	On callback entrance, the value of C<$!> contains the operating system	190	On entry to the callback, the value of C<$!> contains the operating
96	error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>).	191	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		192	C<EPROTO>).
97		193
98	While not mandatory, it is I<highly> recommended to set this callback, as	194	While not mandatory, it is I<highly> recommended to set this callback, as
99	you will not be notified of errors otherwise. The default simply calls	195	you will not be notified of errors otherwise. The default just calls
100	die.	196	C<croak>.
101		197
102	=item on_read => $cb->($self)	198	=item on_read => $cb->($handle)
103		199
104	This sets the default read callback, which is called when data arrives	200	This sets the default read callback, which is called when data arrives
105	and no read request is in the queue.	201	and no read request is in the queue (unlike read queue callbacks, this
		202	callback will only be called when at least one octet of data is in the
		203	read buffer).
106		204
107	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	205	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108	method or access the C<$self->{rbuf}> member directly.	206	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		207	must not enlarge or modify the read buffer, you can only remove data at
		208	the beginning from it.
109		209
		210	You can also call C<< ->push_read (...) >> or any other function that
		211	modifies the read queue. Or do both. Or ...
		212
110	When an EOF condition is detected then AnyEvent::Handle will first try to	213	When an EOF condition is detected, AnyEvent::Handle will first try to
111	feed all the remaining data to the queued callbacks and C<on_read> before	214	feed all the remaining data to the queued callbacks and C<on_read> before
112	calling the C<on_eof> callback. If no progress can be made, then a fatal	215	calling the C<on_eof> callback. If no progress can be made, then a fatal
113	error will be raised (with C<$!> set to C<EPIPE>).	216	error will be raised (with C<$!> set to C<EPIPE>).
114		217
		218	Note that, unlike requests in the read queue, an C<on_read> callback
		219	doesn't mean you I<require> some data: if there is an EOF and there
		220	are outstanding read requests then an error will be flagged. With an
		221	C<on_read> callback, the C<on_eof> callback will be invoked.
		222
		223	=item on_eof => $cb->($handle)
		224
		225	Set the callback to be called when an end-of-file condition is detected,
		226	i.e. in the case of a socket, when the other side has closed the
		227	connection cleanly, and there are no outstanding read requests in the
		228	queue (if there are read requests, then an EOF counts as an unexpected
		229	connection close and will be flagged as an error).
		230
		231	For sockets, this just means that the other side has stopped sending data,
		232	you can still try to write data, and, in fact, one can return from the EOF
		233	callback and continue writing data, as only the read part has been shut
		234	down.
		235
		236	If an EOF condition has been detected but no C<on_eof> callback has been
		237	set, then a fatal error will be raised with C<$!> set to <0>.
		238
115	=item on_drain => $cb->()	239	=item on_drain => $cb->($handle)
116		240
117	This sets the callback that is called when the write buffer becomes empty	241	This sets the callback that is called once when the write buffer becomes
118	(or when the callback is set and the buffer is empty already).	242	empty (and immediately when the handle object is created).
119		243
120	To append to the write buffer, use the C<< ->push_write >> method.	244	To append to the write buffer, use the C<< ->push_write >> method.
		245
		246	This callback is useful when you don't want to put all of your write data
		247	into the queue at once, for example, when you want to write the contents
		248	of some file to the socket you might not want to read the whole file into
		249	memory and push it into the queue, but instead only read more data from
		250	the file when the write queue becomes empty.
		251
		252	=item timeout => $fractional_seconds
		253
		254	=item rtimeout => $fractional_seconds
		255
		256	=item wtimeout => $fractional_seconds
		257
		258	If non-zero, then these enables an "inactivity" timeout: whenever this
		259	many seconds pass without a successful read or write on the underlying
		260	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		261	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		262	error will be raised).
		263
		264	There are three variants of the timeouts that work independently of each
		265	other, for both read and write (triggered when nothing was read I<OR>
		266	written), just read (triggered when nothing was read), and just write:
		267	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		268	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		269	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		270
		271	Note that timeout processing is active even when you do not have any
		272	outstanding read or write requests: If you plan to keep the connection
		273	idle then you should disable the timeout temporarily or ignore the
		274	timeout in the corresponding C<on_timeout> callback, in which case
		275	AnyEvent::Handle will simply restart the timeout.
		276
		277	Zero (the default) disables the corresponding timeout.
		278
		279	=item on_timeout => $cb->($handle)
		280
		281	=item on_rtimeout => $cb->($handle)
		282
		283	=item on_wtimeout => $cb->($handle)
		284
		285	Called whenever the inactivity timeout passes. If you return from this
		286	callback, then the timeout will be reset as if some activity had happened,
		287	so this condition is not fatal in any way.
121		288
122	=item rbuf_max => <bytes>	289	=item rbuf_max => <bytes>
123		290
124	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125	when the read buffer ever (strictly) exceeds this size. This is useful to	292	when the read buffer ever (strictly) exceeds this size. This is useful to
126	avoid denial-of-service attacks.	293	avoid some forms of denial-of-service attacks.
127		294
128	For example, a server accepting connections from untrusted sources should	295	For example, a server accepting connections from untrusted sources should
129	be configured to accept only so-and-so much data that it cannot act on	296	be configured to accept only so-and-so much data that it cannot act on
130	(for example, when expecting a line, an attacker could send an unlimited	297	(for example, when expecting a line, an attacker could send an unlimited
131	amount of data without a callback ever being called as long as the line	298	amount of data without a callback ever being called as long as the line
132	isn't finished).	299	isn't finished).
133		300
		301	=item wbuf_max => <bytes>
		302
		303	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		304	when the write buffer ever (strictly) exceeds this size. This is useful to
		305	avoid some forms of denial-of-service attacks.
		306
		307	Although the units of this parameter is bytes, this is the I<raw> number
		308	of bytes not yet accepted by the kernel. This can make a difference when
		309	you e.g. use TLS, as TLS typically makes your write data larger (but it
		310	can also make it smaller due to compression).
		311
		312	As an example of when this limit is useful, take a chat server that sends
		313	chat messages to a client. If the client does not read those in a timely
		314	manner then the send buffer in the server would grow unbounded.
		315
		316	=item autocork => <boolean>
		317
		318	When disabled (the default), C<push_write> will try to immediately
		319	write the data to the handle if possible. This avoids having to register
		320	a write watcher and wait for the next event loop iteration, but can
		321	be inefficient if you write multiple small chunks (on the wire, this
		322	disadvantage is usually avoided by your kernel's nagle algorithm, see
		323	C<no_delay>, but this option can save costly syscalls).
		324
		325	When enabled, writes will always be queued till the next event loop
		326	iteration. This is efficient when you do many small writes per iteration,
		327	but less efficient when you do a single write only per iteration (or when
		328	the write buffer often is full). It also increases write latency.
		329
		330	=item no_delay => <boolean>
		331
		332	When doing small writes on sockets, your operating system kernel might
		333	wait a bit for more data before actually sending it out. This is called
		334	the Nagle algorithm, and usually it is beneficial.
		335
		336	In some situations you want as low a delay as possible, which can be
		337	accomplishd by setting this option to a true value.
		338
		339	The default is your operating system's default behaviour (most likely
		340	enabled). This option explicitly enables or disables it, if possible.
		341
		342	=item keepalive => <boolean>
		343
		344	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		345	normally, TCP connections have no time-out once established, so TCP
		346	connections, once established, can stay alive forever even when the other
		347	side has long gone. TCP keepalives are a cheap way to take down long-lived
		348	TCP connections when the other side becomes unreachable. While the default
		349	is OS-dependent, TCP keepalives usually kick in after around two hours,
		350	and, if the other side doesn't reply, take down the TCP connection some 10
		351	to 15 minutes later.
		352
		353	It is harmless to specify this option for file handles that do not support
		354	keepalives, and enabling it on connections that are potentially long-lived
		355	is usually a good idea.
		356
		357	=item oobinline => <boolean>
		358
		359	BSD majorly fucked up the implementation of TCP urgent data. The result
		360	is that almost no OS implements TCP according to the specs, and every OS
		361	implements it slightly differently.
		362
		363	If you want to handle TCP urgent data, then setting this flag (the default
		364	is enabled) gives you the most portable way of getting urgent data, by
		365	putting it into the stream.
		366
		367	Since BSD emulation of OOB data on top of TCP's urgent data can have
		368	security implications, AnyEvent::Handle sets this flag automatically
		369	unless explicitly specified. Note that setting this flag after
		370	establishing a connection I<may> be a bit too late (data loss could
		371	already have occured on BSD systems), but at least it will protect you
		372	from most attacks.
		373
134	=item read_size => <bytes>	374	=item read_size => <bytes>
135		375
136	The default read block size (the amount of bytes this module will try to read	376	The initial read block size, the number of bytes this module will try
137	on each [loop iteration). Default: C<4096>.	377	to read during each loop iteration. Each handle object will consume
		378	at least this amount of memory for the read buffer as well, so when
		379	handling many connections watch out for memory requirements). See also
		380	C<max_read_size>. Default: C<2048>.
		381
		382	=item max_read_size => <bytes>
		383
		384	The maximum read buffer size used by the dynamic adjustment
		385	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		386	one go it will double C<read_size> up to the maximum given by this
		387	option. Default: C<131072> or C<read_size>, whichever is higher.
138		388
139	=item low_water_mark => <bytes>	389	=item low_water_mark => <bytes>
140		390
141	Sets the amount of bytes (default: C<0>) that make up an "empty" write	391	Sets the number of bytes (default: C<0>) that make up an "empty" write
142	buffer: If the write reaches this size or gets even samller it is	392	buffer: If the buffer reaches this size or gets even samller it is
143	considered empty.	393	considered empty.
144		394
		395	Sometimes it can be beneficial (for performance reasons) to add data to
		396	the write buffer before it is fully drained, but this is a rare case, as
		397	the operating system kernel usually buffers data as well, so the default
		398	is good in almost all cases.
		399
		400	=item linger => <seconds>
		401
		402	If this is non-zero (default: C<3600>), the destructor of the
		403	AnyEvent::Handle object will check whether there is still outstanding
		404	write data and will install a watcher that will write this data to the
		405	socket. No errors will be reported (this mostly matches how the operating
		406	system treats outstanding data at socket close time).
		407
		408	This will not work for partial TLS data that could not be encoded
		409	yet. This data will be lost. Calling the C<stoptls> method in time might
		410	help.
		411
		412	=item peername => $string
		413
		414	A string used to identify the remote site - usually the DNS hostname
		415	(I<not> IDN!) used to create the connection, rarely the IP address.
		416
		417	Apart from being useful in error messages, this string is also used in TLS
		418	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		419	verification will be skipped when C<peername> is not specified or is
		420	C<undef>.
		421
145	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	422	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146		423
147	When this parameter is given, it enables TLS (SSL) mode, that means it	424	When this parameter is given, it enables TLS (SSL) mode, that means
148	will start making tls handshake and will transparently encrypt/decrypt	425	AnyEvent will start a TLS handshake as soon as the connection has been
149	data.	426	established and will transparently encrypt/decrypt data afterwards.
		427
		428	All TLS protocol errors will be signalled as C<EPROTO>, with an
		429	appropriate error message.
150		430
151	TLS mode requires Net::SSLeay to be installed (it will be loaded	431	TLS mode requires Net::SSLeay to be installed (it will be loaded
152	automatically when you try to create a TLS handle).	432	automatically when you try to create a TLS handle): this module doesn't
		433	have a dependency on that module, so if your module requires it, you have
		434	to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
		435	old, you get an C<EPROTO> error.
153		436
154	For the TLS server side, use C<accept>, and for the TLS client side of a	437	Unlike TCP, TLS has a server and client side: for the TLS server side, use
155	connection, use C<connect> mode.	438	C<accept>, and for the TLS client side of a connection, use C<connect>
		439	mode.
156		440
157	You can also provide your own TLS connection object, but you have	441	You can also provide your own TLS connection object, but you have
158	to make sure that you call either C<Net::SSLeay::set_connect_state>	442	to make sure that you call either C<Net::SSLeay::set_connect_state>
159	or C<Net::SSLeay::set_accept_state> on it before you pass it to	443	or C<Net::SSLeay::set_accept_state> on it before you pass it to
160	AnyEvent::Handle.	444	AnyEvent::Handle. Also, this module will take ownership of this connection
		445	object.
161		446
		447	At some future point, AnyEvent::Handle might switch to another TLS
		448	implementation, then the option to use your own session object will go
		449	away.
		450
		451	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		452	passing in the wrong integer will lead to certain crash. This most often
		453	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		454	segmentation fault.
		455
162	See the C<starttls> method if you need to start TLs negotiation later.	456	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
163		457
164	=item tls_ctx => $ssl_ctx	458	=item tls_ctx => $anyevent_tls
165		459
166	Use the given Net::SSLeay::CTX object to create the new TLS connection	460	Use the given C<AnyEvent::TLS> object to create the new TLS connection
167	(unless a connection object was specified directly). If this parameter is	461	(unless a connection object was specified directly). If this
168	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	462	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		463	C<AnyEvent::Handle::TLS_CTX>.
		464
		465	Instead of an object, you can also specify a hash reference with C<< key
		466	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		467	new TLS context object.
		468
		469	=item on_starttls => $cb->($handle, $success[, $error_message])
		470
		471	This callback will be invoked when the TLS/SSL handshake has finished. If
		472	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		473	(C<on_stoptls> will not be called in this case).
		474
		475	The session in C<< $handle->{tls} >> can still be examined in this
		476	callback, even when the handshake was not successful.
		477
		478	TLS handshake failures will not cause C<on_error> to be invoked when this
		479	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		480
		481	Without this callback, handshake failures lead to C<on_error> being
		482	called as usual.
		483
		484	Note that you cannot just call C<starttls> again in this callback. If you
		485	need to do that, start an zero-second timer instead whose callback can
		486	then call C<< ->starttls >> again.
		487
		488	=item on_stoptls => $cb->($handle)
		489
		490	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		491	set, then it will be invoked after freeing the TLS session. If it is not,
		492	then a TLS shutdown condition will be treated like a normal EOF condition
		493	on the handle.
		494
		495	The session in C<< $handle->{tls} >> can still be examined in this
		496	callback.
		497
		498	This callback will only be called on TLS shutdowns, not when the
		499	underlying handle signals EOF.
		500
		501	=item json => JSON or JSON::XS object
		502
		503	This is the json coder object used by the C<json> read and write types.
		504
		505	If you don't supply it, then AnyEvent::Handle will create and use a
		506	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		507	texts.
		508
		509	Note that you are responsible to depend on the JSON module if you want to
		510	use this functionality, as AnyEvent does not have a dependency itself.
169		511
170	=back	512	=back
171		513
172	=cut	514	=cut
173		515
174	sub new {	516	sub new {
175	my $class = shift;	517	my $class = shift;
176
177	my $self = bless { @_ }, $class;	518	my $self = bless { @_ }, $class;
178		519
179	$self->{fh} or Carp::croak "mandatory argument fh is missing";	520	if ($self->{fh}) {
		521	$self->_start;
		522	return unless $self->{fh}; # could be gone by now
		523
		524	} elsif ($self->{connect}) {
		525	require AnyEvent::Socket;
		526
		527	$self->{peername} = $self->{connect}[0]
		528	unless exists $self->{peername};
		529
		530	$self->{_skip_drain_rbuf} = 1;
		531
		532	{
		533	Scalar::Util::weaken (my $self = $self);
		534
		535	$self->{_connect} =
		536	AnyEvent::Socket::tcp_connect (
		537	$self->{connect}[0],
		538	$self->{connect}[1],
		539	sub {
		540	my ($fh, $host, $port, $retry) = @_;
		541
		542	delete $self->{_connect}; # no longer needed
		543
		544	if ($fh) {
		545	$self->{fh} = $fh;
		546
		547	delete $self->{_skip_drain_rbuf};
		548	$self->_start;
		549
		550	$self->{on_connect}
		551	and $self->{on_connect}($self, $host, $port, sub {
		552	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		553	$self->{_skip_drain_rbuf} = 1;
		554	&$retry;
		555	});
		556
		557	} else {
		558	if ($self->{on_connect_error}) {
		559	$self->{on_connect_error}($self, "$!");
		560	$self->destroy if $self;
		561	} else {
		562	$self->_error ($!, 1);
		563	}
		564	}
		565	},
		566	sub {
		567	local $self->{fh} = $_[0];
		568
		569	$self->{on_prepare}
		570	? $self->{on_prepare}->($self)
		571	: ()
		572	}
		573	);
		574	}
		575
		576	} else {
		577	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		578	}
		579
		580	$self
		581	}
		582
		583	sub _start {
		584	my ($self) = @_;
		585
		586	# too many clueless people try to use udp and similar sockets
		587	# with AnyEvent::Handle, do them a favour.
		588	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		589	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		590	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
180		591
181	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	592	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182		593
183	if ($self->{tls}) {	594	$self->{_activity} =
184	require Net::SSLeay;	595	$self->{_ractivity} =
		596	$self->{_wactivity} = AE::now;
		597
		598	$self->{read_size} ||= 2048;
		599	$self->{max_read_size} = $self->{read_size}
		600	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		601
		602	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		603	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		604	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		605
		606	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		607	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		608
		609	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		610
185	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	611	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186	}	612	if $self->{tls};
187		613
188	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
189	$self->on_error (delete $self->{on_error}) if $self->{on_error};
190	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	614	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
191	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
192		615
193	$self->start_read;	616	$self->start_read
		617	if $self->{on_read} || @{ $self->{_queue} };
194		618
195	$self	619	$self->_drain_wbuf;
196	}	620	}
197		621
198	sub _shutdown {
199	my ($self) = @_;
200
201	delete $self->{rw};
202	delete $self->{ww};
203	delete $self->{fh};
204	}
205
206	sub error {	622	sub _error {
207	my ($self) = @_;	623	my ($self, $errno, $fatal, $message) = @_;
208		624
209	{	625	$! = $errno;
210	local $!;	626	$message ||= "$!";
211	$self->_shutdown;
212	}
213		627
214	if ($self->{on_error}) {	628	if ($self->{on_error}) {
215	$self->{on_error}($self);	629	$self->{on_error}($self, $fatal, $message);
216	} else {	630	$self->destroy if $fatal;
		631	} elsif ($self->{fh} || $self->{connect}) {
		632	$self->destroy;
217	Carp::croak "AnyEvent::Handle uncaught fatal error: $!";	633	Carp::croak "AnyEvent::Handle uncaught error: $message";
218	}	634	}
219	}	635	}
220		636
221	=item $fh = $handle->fh	637	=item $fh = $handle->fh
222		638
223	This method returns the file handle of the L<AnyEvent::Handle> object.	639	This method returns the file handle used to create the L<AnyEvent::Handle> object.
224		640
225	=cut	641	=cut
226		642
227	sub fh { $_[0]->{fh} }	643	sub fh { $_[0]{fh} }
228		644
229	=item $handle->on_error ($cb)	645	=item $handle->on_error ($cb)
230		646
231	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	647	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232		648
…		…
244		660
245	sub on_eof {	661	sub on_eof {
246	$_[0]{on_eof} = $_[1];	662	$_[0]{on_eof} = $_[1];
247	}	663	}
248		664
		665	=item $handle->on_timeout ($cb)
		666
		667	=item $handle->on_rtimeout ($cb)
		668
		669	=item $handle->on_wtimeout ($cb)
		670
		671	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		672	callback, or disables the callback (but not the timeout) if C<$cb> =
		673	C<undef>. See the C<timeout> constructor argument and method.
		674
		675	=cut
		676
		677	# see below
		678
		679	=item $handle->autocork ($boolean)
		680
		681	Enables or disables the current autocork behaviour (see C<autocork>
		682	constructor argument). Changes will only take effect on the next write.
		683
		684	=cut
		685
		686	sub autocork {
		687	$_[0]{autocork} = $_[1];
		688	}
		689
		690	=item $handle->no_delay ($boolean)
		691
		692	Enables or disables the C<no_delay> setting (see constructor argument of
		693	the same name for details).
		694
		695	=cut
		696
		697	sub no_delay {
		698	$_[0]{no_delay} = $_[1];
		699
		700	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		701	if $_[0]{fh};
		702	}
		703
		704	=item $handle->keepalive ($boolean)
		705
		706	Enables or disables the C<keepalive> setting (see constructor argument of
		707	the same name for details).
		708
		709	=cut
		710
		711	sub keepalive {
		712	$_[0]{keepalive} = $_[1];
		713
		714	eval {
		715	local $SIG{__DIE__};
		716	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		717	if $_[0]{fh};
		718	};
		719	}
		720
		721	=item $handle->oobinline ($boolean)
		722
		723	Enables or disables the C<oobinline> setting (see constructor argument of
		724	the same name for details).
		725
		726	=cut
		727
		728	sub oobinline {
		729	$_[0]{oobinline} = $_[1];
		730
		731	eval {
		732	local $SIG{__DIE__};
		733	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		734	if $_[0]{fh};
		735	};
		736	}
		737
		738	=item $handle->keepalive ($boolean)
		739
		740	Enables or disables the C<keepalive> setting (see constructor argument of
		741	the same name for details).
		742
		743	=cut
		744
		745	sub keepalive {
		746	$_[0]{keepalive} = $_[1];
		747
		748	eval {
		749	local $SIG{__DIE__};
		750	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		751	if $_[0]{fh};
		752	};
		753	}
		754
		755	=item $handle->on_starttls ($cb)
		756
		757	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		758
		759	=cut
		760
		761	sub on_starttls {
		762	$_[0]{on_starttls} = $_[1];
		763	}
		764
		765	=item $handle->on_stoptls ($cb)
		766
		767	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		768
		769	=cut
		770
		771	sub on_stoptls {
		772	$_[0]{on_stoptls} = $_[1];
		773	}
		774
		775	=item $handle->rbuf_max ($max_octets)
		776
		777	Configures the C<rbuf_max> setting (C<undef> disables it).
		778
		779	=item $handle->wbuf_max ($max_octets)
		780
		781	Configures the C<wbuf_max> setting (C<undef> disables it).
		782
		783	=cut
		784
		785	sub rbuf_max {
		786	$_[0]{rbuf_max} = $_[1];
		787	}
		788
		789	sub wbuf_max {
		790	$_[0]{wbuf_max} = $_[1];
		791	}
		792
		793	#############################################################################
		794
		795	=item $handle->timeout ($seconds)
		796
		797	=item $handle->rtimeout ($seconds)
		798
		799	=item $handle->wtimeout ($seconds)
		800
		801	Configures (or disables) the inactivity timeout.
		802
		803	The timeout will be checked instantly, so this method might destroy the
		804	handle before it returns.
		805
		806	=item $handle->timeout_reset
		807
		808	=item $handle->rtimeout_reset
		809
		810	=item $handle->wtimeout_reset
		811
		812	Reset the activity timeout, as if data was received or sent.
		813
		814	These methods are cheap to call.
		815
		816	=cut
		817
		818	for my $dir ("", "r", "w") {
		819	my $timeout = "${dir}timeout";
		820	my $tw = "_${dir}tw";
		821	my $on_timeout = "on_${dir}timeout";
		822	my $activity = "_${dir}activity";
		823	my $cb;
		824
		825	*$on_timeout = sub {
		826	$_[0]{$on_timeout} = $_[1];
		827	};
		828
		829	*$timeout = sub {
		830	my ($self, $new_value) = @_;
		831
		832	$new_value >= 0
		833	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		834
		835	$self->{$timeout} = $new_value;
		836	delete $self->{$tw}; &$cb;
		837	};
		838
		839	*{"${dir}timeout_reset"} = sub {
		840	$_[0]{$activity} = AE::now;
		841	};
		842
		843	# main workhorse:
		844	# reset the timeout watcher, as neccessary
		845	# also check for time-outs
		846	$cb = sub {
		847	my ($self) = @_;
		848
		849	if ($self->{$timeout} && $self->{fh}) {
		850	my $NOW = AE::now;
		851
		852	# when would the timeout trigger?
		853	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		854
		855	# now or in the past already?
		856	if ($after <= 0) {
		857	$self->{$activity} = $NOW;
		858
		859	if ($self->{$on_timeout}) {
		860	$self->{$on_timeout}($self);
		861	} else {
		862	$self->_error (Errno::ETIMEDOUT);
		863	}
		864
		865	# callback could have changed timeout value, optimise
		866	return unless $self->{$timeout};
		867
		868	# calculate new after
		869	$after = $self->{$timeout};
		870	}
		871
		872	Scalar::Util::weaken $self;
		873	return unless $self; # ->error could have destroyed $self
		874
		875	$self->{$tw} ||= AE::timer $after, 0, sub {
		876	delete $self->{$tw};
		877	$cb->($self);
		878	};
		879	} else {
		880	delete $self->{$tw};
		881	}
		882	}
		883	}
		884
249	#############################################################################	885	#############################################################################
250		886
251	=back	887	=back
252		888
253	=head2 WRITE QUEUE	889	=head2 WRITE QUEUE
…		…
257		893
258	The write queue is very simple: you can add data to its end, and	894	The write queue is very simple: you can add data to its end, and
259	AnyEvent::Handle will automatically try to get rid of it for you.	895	AnyEvent::Handle will automatically try to get rid of it for you.
260		896
261	When data could be written and the write buffer is shorter then the low	897	When data could be written and the write buffer is shorter then the low
262	water mark, the C<on_drain> callback will be invoked.	898	water mark, the C<on_drain> callback will be invoked once.
263		899
264	=over 4	900	=over 4
265		901
266	=item $handle->on_drain ($cb)	902	=item $handle->on_drain ($cb)
267		903
268	Sets the C<on_drain> callback or clears it (see the description of	904	Sets the C<on_drain> callback or clears it (see the description of
269	C<on_drain> in the constructor).	905	C<on_drain> in the constructor).
270		906
		907	This method may invoke callbacks (and therefore the handle might be
		908	destroyed after it returns).
		909
271	=cut	910	=cut
272		911
273	sub on_drain {	912	sub on_drain {
274	my ($self, $cb) = @_;	913	my ($self, $cb) = @_;
275		914
276	$self->{on_drain} = $cb;	915	$self->{on_drain} = $cb;
277		916
278	$cb->($self)	917	$cb->($self)
279	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	918	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280	}	919	}
281		920
282	=item $handle->push_write ($data)	921	=item $handle->push_write ($data)
283		922
284	Queues the given scalar to be written. You can push as much data as you	923	Queues the given scalar to be written. You can push as much data as
285	want (only limited by the available memory), as C<AnyEvent::Handle>	924	you want (only limited by the available memory and C<wbuf_max>), as
286	buffers it independently of the kernel.	925	C<AnyEvent::Handle> buffers it independently of the kernel.
		926
		927	This method may invoke callbacks (and therefore the handle might be
		928	destroyed after it returns).
287		929
288	=cut	930	=cut
289		931
290	sub _drain_wbuf {	932	sub _drain_wbuf {
291	my ($self) = @_;	933	my ($self) = @_;
292		934
293	if (!$self->{ww} && length $self->{wbuf}) {	935	if (!$self->{_ww} && length $self->{wbuf}) {
		936
294	Scalar::Util::weaken $self;	937	Scalar::Util::weaken $self;
		938
295	my $cb = sub {	939	my $cb = sub {
296	my $len = syswrite $self->{fh}, $self->{wbuf};	940	my $len = syswrite $self->{fh}, $self->{wbuf};
297		941
298	if ($len >= 0) {	942	if (defined $len) {
299	substr $self->{wbuf}, 0, $len, "";	943	substr $self->{wbuf}, 0, $len, "";
300		944
		945	$self->{_activity} = $self->{_wactivity} = AE::now;
		946
301	$self->{on_drain}($self)	947	$self->{on_drain}($self)
302	if $self->{low_water_mark} >= length $self->{wbuf}	948	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303	&& $self->{on_drain};	949	&& $self->{on_drain};
304		950
305	delete $self->{ww} unless length $self->{wbuf};	951	delete $self->{_ww} unless length $self->{wbuf};
306	} elsif ($! != EAGAIN && $! != EINTR) {	952	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307	$self->error;	953	$self->_error ($!, 1);
308	}	954	}
309	};	955	};
310		956
311	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	957	# try to write data immediately
		958	$cb->() unless $self->{autocork};
312		959
313	$cb->($self);	960	# if still data left in wbuf, we need to poll
		961	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		962	if length $self->{wbuf};
		963
		964	if (
		965	defined $self->{wbuf_max}
		966	&& $self->{wbuf_max} < length $self->{wbuf}
		967	) {
		968	$self->_error (Errno::ENOSPC, 1), return;
		969	}
314	};	970	};
315	}	971	}
316		972
317	our %WH;	973	our %WH;
318		974
		975	# deprecated
319	sub register_write_type($$) {	976	sub register_write_type($$) {
320	$WH{$_[0]} = $_[1];	977	$WH{$_[0]} = $_[1];
321	}	978	}
322		979
323	sub push_write {	980	sub push_write {
324	my $self = shift;	981	my $self = shift;
325		982
326	if (@_ > 1) {	983	if (@_ > 1) {
327	my $type = shift;	984	my $type = shift;
328		985
		986	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
329	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	987	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
330	->($self, @_);	988	->($self, @_);
331	}	989	}
332		990
		991	# we downgrade here to avoid hard-to-track-down bugs,
		992	# and diagnose the problem earlier and better.
		993
333	if ($self->{filter_w}) {	994	if ($self->{tls}) {
334	$self->{filter_w}->($self, \$_[0]);	995	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		996	&_dotls ($self) if $self->{fh};
335	} else {	997	} else {
336	$self->{wbuf} .= $_[0];	998	utf8::downgrade $self->{wbuf} .= $_[0];
337	$self->_drain_wbuf;	999	$self->_drain_wbuf if $self->{fh};
338	}	1000	}
339	}	1001	}
340		1002
341	=item $handle->push_write (type => @args)	1003	=item $handle->push_write (type => @args)
342		1004
343	=item $handle->unshift_write (type => @args)
344
345	Instead of formatting your data yourself, you can also let this module do	1005	Instead of formatting your data yourself, you can also let this module
346	the job by specifying a type and type-specific arguments.	1006	do the job by specifying a type and type-specific arguments. You
		1007	can also specify the (fully qualified) name of a package, in which
		1008	case AnyEvent tries to load the package and then expects to find the
		1009	C<anyevent_write_type> function inside (see "custom write types", below).
347		1010
348	Predefined types are (if you have ideas for additional types, feel free to	1011	Predefined types are (if you have ideas for additional types, feel free to
349	drop by and tell us):	1012	drop by and tell us):
350		1013
351	=over 4	1014	=over 4
…		…
353	=item netstring => $string	1016	=item netstring => $string
354		1017
355	Formats the given value as netstring	1018	Formats the given value as netstring
356	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).	1019	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357		1020
358	=back
359
360	=cut	1021	=cut
361		1022
362	register_write_type netstring => sub {	1023	register_write_type netstring => sub {
363	my ($self, $string) = @_;	1024	my ($self, $string) = @_;
364		1025
365	sprintf "%d:%s,", (length $string), $string	1026	(length $string) . ":$string,"
366	};	1027	};
367		1028
368	=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args)	1029	=item packstring => $format, $data
369		1030
370	This function (not method) lets you add your own types to C<push_write>.	1031	An octet string prefixed with an encoded length. The encoding C<$format>
		1032	uses the same format as a Perl C<pack> format, but must specify a single
		1033	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1034	optional C<!>, C<< < >> or C<< > >> modifier).
		1035
		1036	=cut
		1037
		1038	register_write_type packstring => sub {
		1039	my ($self, $format, $string) = @_;
		1040
		1041	pack "$format/a*", $string
		1042	};
		1043
		1044	=item json => $array_or_hashref
		1045
		1046	Encodes the given hash or array reference into a JSON object. Unless you
		1047	provide your own JSON object, this means it will be encoded to JSON text
		1048	in UTF-8.
		1049
		1050	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		1051	one end of a handle and read them at the other end without using any
		1052	additional framing.
		1053
		1054	The generated JSON text is guaranteed not to contain any newlines: While
		1055	this module doesn't need delimiters after or between JSON texts to be
		1056	able to read them, many other languages depend on that.
		1057
		1058	A simple RPC protocol that interoperates easily with others is to send
		1059	JSON arrays (or objects, although arrays are usually the better choice as
		1060	they mimic how function argument passing works) and a newline after each
		1061	JSON text:
		1062
		1063	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1064	$handle->push_write ("\012");
		1065
		1066	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1067	rely on the fact that the newline will be skipped as leading whitespace:
		1068
		1069	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1070
		1071	Other languages could read single lines terminated by a newline and pass
		1072	this line into their JSON decoder of choice.
		1073
		1074	=cut
		1075
		1076	sub json_coder() {
		1077	eval { require JSON::XS; JSON::XS->new->utf8 }
		1078	|| do { require JSON; JSON->new->utf8 }
		1079	}
		1080
		1081	register_write_type json => sub {
		1082	my ($self, $ref) = @_;
		1083
		1084	my $json = $self->{json} ||= json_coder;
		1085
		1086	$json->encode ($ref)
		1087	};
		1088
		1089	=item storable => $reference
		1090
		1091	Freezes the given reference using L<Storable> and writes it to the
		1092	handle. Uses the C<nfreeze> format.
		1093
		1094	=cut
		1095
		1096	register_write_type storable => sub {
		1097	my ($self, $ref) = @_;
		1098
		1099	require Storable unless $Storable::VERSION;
		1100
		1101	pack "w/a*", Storable::nfreeze ($ref)
		1102	};
		1103
		1104	=back
		1105
		1106	=item $handle->push_shutdown
		1107
		1108	Sometimes you know you want to close the socket after writing your data
		1109	before it was actually written. One way to do that is to replace your
		1110	C<on_drain> handler by a callback that shuts down the socket (and set
		1111	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1112	replaces the C<on_drain> callback with:
		1113
		1114	sub { shutdown $_[0]{fh}, 1 }
		1115
		1116	This simply shuts down the write side and signals an EOF condition to the
		1117	the peer.
		1118
		1119	You can rely on the normal read queue and C<on_eof> handling
		1120	afterwards. This is the cleanest way to close a connection.
		1121
		1122	This method may invoke callbacks (and therefore the handle might be
		1123	destroyed after it returns).
		1124
		1125	=cut
		1126
		1127	sub push_shutdown {
		1128	my ($self) = @_;
		1129
		1130	delete $self->{low_water_mark};
		1131	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1132	}
		1133
		1134	=item custom write types - Package::anyevent_write_type $handle, @args
		1135
		1136	Instead of one of the predefined types, you can also specify the name of
		1137	a package. AnyEvent will try to load the package and then expects to find
		1138	a function named C<anyevent_write_type> inside. If it isn't found, it
		1139	progressively tries to load the parent package until it either finds the
		1140	function (good) or runs out of packages (bad).
		1141
371	Whenever the given C<type> is used, C<push_write> will invoke the code	1142	Whenever the given C<type> is used, C<push_write> will the function with
372	reference with the handle object and the remaining arguments.	1143	the handle object and the remaining arguments.
373		1144
374	The code reference is supposed to return a single octet string that will	1145	The function is supposed to return a single octet string that will be
375	be appended to the write buffer.	1146	appended to the write buffer, so you can mentally treat this function as a
		1147	"arguments to on-the-wire-format" converter.
376		1148
377	Note that this is a function, and all types registered this way will be	1149	Example: implement a custom write type C<join> that joins the remaining
378	global, so try to use unique names.	1150	arguments using the first one.
		1151
		1152	$handle->push_write (My::Type => " ", 1,2,3);
		1153
		1154	# uses the following package, which can be defined in the "My::Type" or in
		1155	# the "My" modules to be auto-loaded, or just about anywhere when the
		1156	# My::Type::anyevent_write_type is defined before invoking it.
		1157
		1158	package My::Type;
		1159
		1160	sub anyevent_write_type {
		1161	my ($handle, $delim, @args) = @_;
		1162
		1163	join $delim, @args
		1164	}
379		1165
380	=cut	1166	=cut
381		1167
382	#############################################################################	1168	#############################################################################
383		1169
…		…
392	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1178	ways, the "simple" way, using only C<on_read> and the "complex" way, using
393	a queue.	1179	a queue.
394		1180
395	In the simple case, you just install an C<on_read> callback and whenever	1181	In the simple case, you just install an C<on_read> callback and whenever
396	new data arrives, it will be called. You can then remove some data (if	1182	new data arrives, it will be called. You can then remove some data (if
397	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	1183	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
398	or not.	1184	leave the data there if you want to accumulate more (e.g. when only a
		1185	partial message has been received so far), or change the read queue with
		1186	e.g. C<push_read>.
399		1187
400	In the more complex case, you want to queue multiple callbacks. In this	1188	In the more complex case, you want to queue multiple callbacks. In this
401	case, AnyEvent::Handle will call the first queued callback each time new	1189	case, AnyEvent::Handle will call the first queued callback each time new
402	data arrives and removes it when it has done its job (see C<push_read>,	1190	data arrives (also the first time it is queued) and remove it when it has
403	below).	1191	done its job (see C<push_read>, below).
404		1192
405	This way you can, for example, push three line-reads, followed by reading	1193	This way you can, for example, push three line-reads, followed by reading
406	a chunk of data, and AnyEvent::Handle will execute them in order.	1194	a chunk of data, and AnyEvent::Handle will execute them in order.
407		1195
408	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1196	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409	the specified number of bytes which give an XML datagram.	1197	the specified number of bytes which give an XML datagram.
410		1198
411	# in the default state, expect some header bytes	1199	# in the default state, expect some header bytes
412	$handle->on_read (sub {	1200	$handle->on_read (sub {
413	# some data is here, now queue the length-header-read (4 octets)	1201	# some data is here, now queue the length-header-read (4 octets)
414	shift->unshift_read_chunk (4, sub {	1202	shift->unshift_read (chunk => 4, sub {
415	# header arrived, decode	1203	# header arrived, decode
416	my $len = unpack "N", $_[1];	1204	my $len = unpack "N", $_[1];
417		1205
418	# now read the payload	1206	# now read the payload
419	shift->unshift_read_chunk ($len, sub {	1207	shift->unshift_read (chunk => $len, sub {
420	my $xml = $_[1];	1208	my $xml = $_[1];
421	# handle xml	1209	# handle xml
422	});	1210	});
423	});	1211	});
424	});	1212	});
425		1213
426	Example 2: Implement a client for a protocol that replies either with	1214	Example 2: Implement a client for a protocol that replies either with "OK"
427	"OK" and another line or "ERROR" for one request, and 64 bytes for the	1215	and another line or "ERROR" for the first request that is sent, and 64
428	second request. Due tot he availability of a full queue, we can just	1216	bytes for the second request. Due to the availability of a queue, we can
429	pipeline sending both requests and manipulate the queue as necessary in	1217	just pipeline sending both requests and manipulate the queue as necessary
430	the callbacks:	1218	in the callbacks.
431		1219
432	# request one	1220	When the first callback is called and sees an "OK" response, it will
		1221	C<unshift> another line-read. This line-read will be queued I<before> the
		1222	64-byte chunk callback.
		1223
		1224	# request one, returns either "OK + extra line" or "ERROR"
433	$handle->push_write ("request 1\015\012");	1225	$handle->push_write ("request 1\015\012");
434		1226
435	# we expect "ERROR" or "OK" as response, so push a line read	1227	# we expect "ERROR" or "OK" as response, so push a line read
436	$handle->push_read_line (sub {	1228	$handle->push_read (line => sub {
437	# if we got an "OK", we have to _prepend_ another line,	1229	# if we got an "OK", we have to _prepend_ another line,
438	# so it will be read before the second request reads its 64 bytes	1230	# so it will be read before the second request reads its 64 bytes
439	# which are already in the queue when this callback is called	1231	# which are already in the queue when this callback is called
440	# we don't do this in case we got an error	1232	# we don't do this in case we got an error
441	if ($_[1] eq "OK") {	1233	if ($_[1] eq "OK") {
442	$_[0]->unshift_read_line (sub {	1234	$_[0]->unshift_read (line => sub {
443	my $response = $_[1];	1235	my $response = $_[1];
444	...	1236	...
445	});	1237	});
446	}	1238	}
447	});	1239	});
448		1240
449	# request two	1241	# request two, simply returns 64 octets
450	$handle->push_write ("request 2\015\012");	1242	$handle->push_write ("request 2\015\012");
451		1243
452	# simply read 64 bytes, always	1244	# simply read 64 bytes, always
453	$handle->push_read_chunk (64, sub {	1245	$handle->push_read (chunk => 64, sub {
454	my $response = $_[1];	1246	my $response = $_[1];
455	...	1247	...
456	});	1248	});
457		1249
458	=over 4	1250	=over 4
459		1251
460	=cut	1252	=cut
461		1253
462	sub _drain_rbuf {	1254	sub _drain_rbuf {
463	my ($self) = @_;	1255	my ($self) = @_;
		1256
		1257	# avoid recursion
		1258	return if $self->{_skip_drain_rbuf};
		1259	local $self->{_skip_drain_rbuf} = 1;
		1260
		1261	while () {
		1262	# we need to use a separate tls read buffer, as we must not receive data while
		1263	# we are draining the buffer, and this can only happen with TLS.
		1264	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1265	if exists $self->{_tls_rbuf};
		1266
		1267	my $len = length $self->{rbuf};
		1268
		1269	if (my $cb = shift @{ $self->{_queue} }) {
		1270	unless ($cb->($self)) {
		1271	# no progress can be made
		1272	# (not enough data and no data forthcoming)
		1273	$self->_error (Errno::EPIPE, 1), return
		1274	if $self->{_eof};
		1275
		1276	unshift @{ $self->{_queue} }, $cb;
		1277	last;
		1278	}
		1279	} elsif ($self->{on_read}) {
		1280	last unless $len;
		1281
		1282	$self->{on_read}($self);
		1283
		1284	if (
		1285	$len == length $self->{rbuf} # if no data has been consumed
		1286	&& !@{ $self->{_queue} } # and the queue is still empty
		1287	&& $self->{on_read} # but we still have on_read
		1288	) {
		1289	# no further data will arrive
		1290	# so no progress can be made
		1291	$self->_error (Errno::EPIPE, 1), return
		1292	if $self->{_eof};
		1293
		1294	last; # more data might arrive
		1295	}
		1296	} else {
		1297	# read side becomes idle
		1298	delete $self->{_rw} unless $self->{tls};
		1299	last;
		1300	}
		1301	}
		1302
		1303	if ($self->{_eof}) {
		1304	$self->{on_eof}
		1305	? $self->{on_eof}($self)
		1306	: $self->_error (0, 1, "Unexpected end-of-file");
		1307
		1308	return;
		1309	}
464		1310
465	if (	1311	if (
466	defined $self->{rbuf_max}	1312	defined $self->{rbuf_max}
467	&& $self->{rbuf_max} < length $self->{rbuf}	1313	&& $self->{rbuf_max} < length $self->{rbuf}
468	) {	1314	) {
469	$! = &Errno::ENOSPC; return $self->error;	1315	$self->_error (Errno::ENOSPC, 1), return;
470	}	1316	}
471		1317
472	return if $self->{in_drain};	1318	# may need to restart read watcher
473	local $self->{in_drain} = 1;	1319	unless ($self->{_rw}) {
474		1320	$self->start_read
475	while (my $len = length $self->{rbuf}) {	1321	if $self->{on_read} || @{ $self->{_queue} };
476	no strict 'refs';
477	if (my $cb = shift @{ $self->{queue} }) {
478	unless ($cb->($self)) {
479	if ($self->{eof}) {
480	# no progress can be made (not enough data and no data forthcoming)
481	$! = &Errno::EPIPE; return $self->error;
482	}
483
484	unshift @{ $self->{queue} }, $cb;
485	return;
486	}
487	} elsif ($self->{on_read}) {
488	$self->{on_read}($self);
489
490	if (
491	$self->{eof} # if no further data will arrive
492	&& $len == length $self->{rbuf} # and no data has been consumed
493	&& !@{ $self->{queue} } # and the queue is still empty
494	&& $self->{on_read} # and we still want to read data
495	) {
496	# then no progress can be made
497	$! = &Errno::EPIPE; return $self->error;
498	}
499	} else {
500	# read side becomes idle
501	delete $self->{rw};
502	return;
503	}
504	}
505
506	if ($self->{eof}) {
507	$self->_shutdown;
508	$self->{on_eof}($self)
509	if $self->{on_eof};
510	}	1322	}
511	}	1323	}
512		1324
513	=item $handle->on_read ($cb)	1325	=item $handle->on_read ($cb)
514		1326
515	This replaces the currently set C<on_read> callback, or clears it (when	1327	This replaces the currently set C<on_read> callback, or clears it (when
516	the new callback is C<undef>). See the description of C<on_read> in the	1328	the new callback is C<undef>). See the description of C<on_read> in the
517	constructor.	1329	constructor.
518		1330
		1331	This method may invoke callbacks (and therefore the handle might be
		1332	destroyed after it returns).
		1333
519	=cut	1334	=cut
520		1335
521	sub on_read {	1336	sub on_read {
522	my ($self, $cb) = @_;	1337	my ($self, $cb) = @_;
523		1338
524	$self->{on_read} = $cb;	1339	$self->{on_read} = $cb;
		1340	$self->_drain_rbuf if $cb;
525	}	1341	}
526		1342
527	=item $handle->rbuf	1343	=item $handle->rbuf
528		1344
529	Returns the read buffer (as a modifiable lvalue).	1345	Returns the read buffer (as a modifiable lvalue). You can also access the
		1346	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1347	much faster, and no less clean).
530		1348
531	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1349	The only operation allowed on the read buffer (apart from looking at it)
532	you want.	1350	is removing data from its beginning. Otherwise modifying or appending to
		1351	it is not allowed and will lead to hard-to-track-down bugs.
533		1352
534	NOTE: The read buffer should only be used or modified if the C<on_read>,	1353	NOTE: The read buffer should only be used or modified in the C<on_read>
535	C<push_read> or C<unshift_read> methods are used. The other read methods	1354	callback or when C<push_read> or C<unshift_read> are used with a single
536	automatically manage the read buffer.	1355	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1356	will manage the read buffer on their own.
537		1357
538	=cut	1358	=cut
539		1359
540	sub rbuf : lvalue {	1360	sub rbuf : lvalue {
541	$_[0]{rbuf}	1361	$_[0]{rbuf}
…		…
558		1378
559	If enough data was available, then the callback must remove all data it is	1379	If enough data was available, then the callback must remove all data it is
560	interested in (which can be none at all) and return a true value. After returning	1380	interested in (which can be none at all) and return a true value. After returning
561	true, it will be removed from the queue.	1381	true, it will be removed from the queue.
562		1382
		1383	These methods may invoke callbacks (and therefore the handle might be
		1384	destroyed after it returns).
		1385
563	=cut	1386	=cut
564		1387
565	our %RH;	1388	our %RH;
566		1389
567	sub register_read_type($$) {	1390	sub register_read_type($$) {
…		…
573	my $cb = pop;	1396	my $cb = pop;
574		1397
575	if (@_) {	1398	if (@_) {
576	my $type = shift;	1399	my $type = shift;
577		1400
		1401	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
578	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1402	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
579	->($self, $cb, @_);	1403	->($self, $cb, @_);
580	}	1404	}
581		1405
582	push @{ $self->{queue} }, $cb;	1406	push @{ $self->{_queue} }, $cb;
583	$self->_drain_rbuf;	1407	$self->_drain_rbuf;
584	}	1408	}
585		1409
586	sub unshift_read {	1410	sub unshift_read {
587	my $self = shift;	1411	my $self = shift;
588	my $cb = pop;	1412	my $cb = pop;
589		1413
590	if (@_) {	1414	if (@_) {
591	my $type = shift;	1415	my $type = shift;
592		1416
		1417	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
593	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1418	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
594	->($self, $cb, @_);	1419	->($self, $cb, @_);
595	}	1420	}
596		1421
597
598	unshift @{ $self->{queue} }, $cb;	1422	unshift @{ $self->{_queue} }, $cb;
599	$self->_drain_rbuf;	1423	$self->_drain_rbuf;
600	}	1424	}
601		1425
602	=item $handle->push_read (type => @args, $cb)	1426	=item $handle->push_read (type => @args, $cb)
603		1427
604	=item $handle->unshift_read (type => @args, $cb)	1428	=item $handle->unshift_read (type => @args, $cb)
605		1429
606	Instead of providing a callback that parses the data itself you can chose	1430	Instead of providing a callback that parses the data itself you can chose
607	between a number of predefined parsing formats, for chunks of data, lines	1431	between a number of predefined parsing formats, for chunks of data, lines
608	etc.	1432	etc. You can also specify the (fully qualified) name of a package, in
		1433	which case AnyEvent tries to load the package and then expects to find the
		1434	C<anyevent_read_type> function inside (see "custom read types", below).
609		1435
610	Predefined types are (if you have ideas for additional types, feel free to	1436	Predefined types are (if you have ideas for additional types, feel free to
611	drop by and tell us):	1437	drop by and tell us):
612		1438
613	=over 4	1439	=over 4
614		1440
615	=item chunk => $octets, $cb->($self, $data)	1441	=item chunk => $octets, $cb->($handle, $data)
616		1442
617	Invoke the callback only once C<$octets> bytes have been read. Pass the	1443	Invoke the callback only once C<$octets> bytes have been read. Pass the
618	data read to the callback. The callback will never be called with less	1444	data read to the callback. The callback will never be called with less
619	data.	1445	data.
620		1446
621	Example: read 2 bytes.	1447	Example: read 2 bytes.
622		1448
623	$handle->push_read (chunk => 2, sub {	1449	$handle->push_read (chunk => 2, sub {
624	warn "yay ", unpack "H*", $_[1];	1450	say "yay " . unpack "H*", $_[1];
625	});	1451	});
626		1452
627	=cut	1453	=cut
628		1454
629	register_read_type chunk => sub {	1455	register_read_type chunk => sub {
…		…
634	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1460	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635	1	1461	1
636	}	1462	}
637	};	1463	};
638		1464
639	# compatibility with older API
640	sub push_read_chunk {
641	$_[0]->push_read (chunk => $_[1], $_[2]);
642	}
643
644	sub unshift_read_chunk {
645	$_[0]->unshift_read (chunk => $_[1], $_[2]);
646	}
647
648	=item line => [$eol, ]$cb->($self, $line, $eol)	1465	=item line => [$eol, ]$cb->($handle, $line, $eol)
649		1466
650	The callback will be called only once a full line (including the end of	1467	The callback will be called only once a full line (including the end of
651	line marker, C<$eol>) has been read. This line (excluding the end of line	1468	line marker, C<$eol>) has been read. This line (excluding the end of line
652	marker) will be passed to the callback as second argument (C<$line>), and	1469	marker) will be passed to the callback as second argument (C<$line>), and
653	the end of line marker as the third argument (C<$eol>).	1470	the end of line marker as the third argument (C<$eol>).
…		…
667	=cut	1484	=cut
668		1485
669	register_read_type line => sub {	1486	register_read_type line => sub {
670	my ($self, $cb, $eol) = @_;	1487	my ($self, $cb, $eol) = @_;
671		1488
672	$eol = qr|(\015?\012)| if @_ < 3;	1489	if (@_ < 3) {
		1490	# this is faster then the generic code below
		1491	sub {
		1492	(my $pos = index $_[0]{rbuf}, "\012") >= 0
		1493	or return;
		1494
		1495	(my $str = substr $_[0]{rbuf}, 0, $pos + 1, "") =~ s/(\015?\012)\Z// or die;
		1496	$cb->($_[0], $str, "$1");
		1497	1
		1498	}
		1499	} else {
673	$eol = quotemeta $eol unless ref $eol;	1500	$eol = quotemeta $eol unless ref $eol;
674	$eol = qr|^(.*?)($eol)|s;	1501	$eol = qr|^(.*?)($eol)|s;
		1502
		1503	sub {
		1504	$_[0]{rbuf} =~ s/$eol// or return;
		1505
		1506	$cb->($_[0], "$1", "$2");
		1507	1
		1508	}
		1509	}
		1510	};
		1511
		1512	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1513
		1514	Makes a regex match against the regex object C<$accept> and returns
		1515	everything up to and including the match.
		1516
		1517	Example: read a single line terminated by '\n'.
		1518
		1519	$handle->push_read (regex => qr<\n>, sub { ... });
		1520
		1521	If C<$reject> is given and not undef, then it determines when the data is
		1522	to be rejected: it is matched against the data when the C<$accept> regex
		1523	does not match and generates an C<EBADMSG> error when it matches. This is
		1524	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1525	receive buffer overflow).
		1526
		1527	Example: expect a single decimal number followed by whitespace, reject
		1528	anything else (not the use of an anchor).
		1529
		1530	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1531
		1532	If C<$skip> is given and not C<undef>, then it will be matched against
		1533	the receive buffer when neither C<$accept> nor C<$reject> match,
		1534	and everything preceding and including the match will be accepted
		1535	unconditionally. This is useful to skip large amounts of data that you
		1536	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1537	have to start matching from the beginning. This is purely an optimisation
		1538	and is usually worth it only when you expect more than a few kilobytes.
		1539
		1540	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1541	expect the header to be very large (it isn't in practice, but...), we use
		1542	a skip regex to skip initial portions. The skip regex is tricky in that
		1543	it only accepts something not ending in either \015 or \012, as these are
		1544	required for the accept regex.
		1545
		1546	$handle->push_read (regex =>
		1547	qr<\015\012\015\012>,
		1548	undef, # no reject
		1549	qr<^.*[^\015\012]>,
		1550	sub { ... });
		1551
		1552	=cut
		1553
		1554	register_read_type regex => sub {
		1555	my ($self, $cb, $accept, $reject, $skip) = @_;
		1556
		1557	my $data;
		1558	my $rbuf = \$self->{rbuf};
675		1559
676	sub {	1560	sub {
677	$_[0]{rbuf} =~ s/$eol// or return;	1561	# accept
678		1562	if ($$rbuf =~ $accept) {
		1563	$data .= substr $$rbuf, 0, $+[0], "";
679	$cb->($_[0], $1, $2);	1564	$cb->($_[0], $data);
		1565	return 1;
		1566	}
680	1	1567
		1568	# reject
		1569	if ($reject && $$rbuf =~ $reject) {
		1570	$_[0]->_error (Errno::EBADMSG);
		1571	}
		1572
		1573	# skip
		1574	if ($skip && $$rbuf =~ $skip) {
		1575	$data .= substr $$rbuf, 0, $+[0], "";
		1576	}
		1577
		1578	()
681	}	1579	}
682	};	1580	};
683		1581
684	# compatibility with older API
685	sub push_read_line {
686	my $self = shift;
687	$self->push_read (line => @_);
688	}
689
690	sub unshift_read_line {
691	my $self = shift;
692	$self->unshift_read (line => @_);
693	}
694
695	=item netstring => $cb->($string)	1582	=item netstring => $cb->($handle, $string)
696		1583
697	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).	1584	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698		1585
699	Throws an error with C<$!> set to EBADMSG on format violations.	1586	Throws an error with C<$!> set to EBADMSG on format violations.
700		1587
…		…
704	my ($self, $cb) = @_;	1591	my ($self, $cb) = @_;
705		1592
706	sub {	1593	sub {
707	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1594	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708	if ($_[0]{rbuf} =~ /[^0-9]/) {	1595	if ($_[0]{rbuf} =~ /[^0-9]/) {
709	$! = &Errno::EBADMSG;	1596	$_[0]->_error (Errno::EBADMSG);
710	$self->error;
711	}	1597	}
712	return;	1598	return;
713	}	1599	}
714		1600
715	my $len = $1;	1601	my $len = $1;
716		1602
717	$self->unshift_read (chunk => $len, sub {	1603	$_[0]->unshift_read (chunk => $len, sub {
718	my $string = $_[1];	1604	my $string = $_[1];
719	$_[0]->unshift_read (chunk => 1, sub {	1605	$_[0]->unshift_read (chunk => 1, sub {
720	if ($_[1] eq ",") {	1606	if ($_[1] eq ",") {
721	$cb->($_[0], $string);	1607	$cb->($_[0], $string);
722	} else {	1608	} else {
723	$! = &Errno::EBADMSG;	1609	$_[0]->_error (Errno::EBADMSG);
724	$self->error;
725	}	1610	}
726	});	1611	});
727	});	1612	});
728		1613
729	1	1614	1
730	}	1615	}
731	};	1616	};
732		1617
		1618	=item packstring => $format, $cb->($handle, $string)
		1619
		1620	An octet string prefixed with an encoded length. The encoding C<$format>
		1621	uses the same format as a Perl C<pack> format, but must specify a single
		1622	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1623	optional C<!>, C<< < >> or C<< > >> modifier).
		1624
		1625	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1626	EPP uses a prefix of C<N> (4 octtes).
		1627
		1628	Example: read a block of data prefixed by its length in BER-encoded
		1629	format (very efficient).
		1630
		1631	$handle->push_read (packstring => "w", sub {
		1632	my ($handle, $data) = @_;
		1633	});
		1634
		1635	=cut
		1636
		1637	register_read_type packstring => sub {
		1638	my ($self, $cb, $format) = @_;
		1639
		1640	sub {
		1641	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1642	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1643	or return;
		1644
		1645	$format = length pack $format, $len;
		1646
		1647	# bypass unshift if we already have the remaining chunk
		1648	if ($format + $len <= length $_[0]{rbuf}) {
		1649	my $data = substr $_[0]{rbuf}, $format, $len;
		1650	substr $_[0]{rbuf}, 0, $format + $len, "";
		1651	$cb->($_[0], $data);
		1652	} else {
		1653	# remove prefix
		1654	substr $_[0]{rbuf}, 0, $format, "";
		1655
		1656	# read remaining chunk
		1657	$_[0]->unshift_read (chunk => $len, $cb);
		1658	}
		1659
		1660	1
		1661	}
		1662	};
		1663
		1664	=item json => $cb->($handle, $hash_or_arrayref)
		1665
		1666	Reads a JSON object or array, decodes it and passes it to the
		1667	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1668
		1669	If a C<json> object was passed to the constructor, then that will be used
		1670	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1671
		1672	This read type uses the incremental parser available with JSON version
		1673	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1674	dependency on your own: this module will load the JSON module, but
		1675	AnyEvent does not depend on it itself.
		1676
		1677	Since JSON texts are fully self-delimiting, the C<json> read and write
		1678	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1679	the C<json> write type description, above, for an actual example.
		1680
		1681	=cut
		1682
		1683	register_read_type json => sub {
		1684	my ($self, $cb) = @_;
		1685
		1686	my $json = $self->{json} ||= json_coder;
		1687
		1688	my $data;
		1689	my $rbuf = \$self->{rbuf};
		1690
		1691	sub {
		1692	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
		1693
		1694	if ($ref) {
		1695	$_[0]{rbuf} = $json->incr_text;
		1696	$json->incr_text = "";
		1697	$cb->($_[0], $ref);
		1698
		1699	1
		1700	} elsif ($@) {
		1701	# error case
		1702	$json->incr_skip;
		1703
		1704	$_[0]{rbuf} = $json->incr_text;
		1705	$json->incr_text = "";
		1706
		1707	$_[0]->_error (Errno::EBADMSG);
		1708
		1709	()
		1710	} else {
		1711	$_[0]{rbuf} = "";
		1712
		1713	()
		1714	}
		1715	}
		1716	};
		1717
		1718	=item storable => $cb->($handle, $ref)
		1719
		1720	Deserialises a L<Storable> frozen representation as written by the
		1721	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1722	data).
		1723
		1724	Raises C<EBADMSG> error if the data could not be decoded.
		1725
		1726	=cut
		1727
		1728	register_read_type storable => sub {
		1729	my ($self, $cb) = @_;
		1730
		1731	require Storable unless $Storable::VERSION;
		1732
		1733	sub {
		1734	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1735	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1736	or return;
		1737
		1738	my $format = length pack "w", $len;
		1739
		1740	# bypass unshift if we already have the remaining chunk
		1741	if ($format + $len <= length $_[0]{rbuf}) {
		1742	my $data = substr $_[0]{rbuf}, $format, $len;
		1743	substr $_[0]{rbuf}, 0, $format + $len, "";
		1744
		1745	eval { $cb->($_[0], Storable::thaw ($data)); 1 }
		1746	or return $_[0]->_error (Errno::EBADMSG);
		1747	} else {
		1748	# remove prefix
		1749	substr $_[0]{rbuf}, 0, $format, "";
		1750
		1751	# read remaining chunk
		1752	$_[0]->unshift_read (chunk => $len, sub {
		1753	eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
		1754	or $_[0]->_error (Errno::EBADMSG);
		1755	});
		1756	}
		1757
		1758	1
		1759	}
		1760	};
		1761
		1762	=item tls_detect => $cb->($handle, $detect, $major, $minor)
		1763
		1764	Checks the input stream for a valid SSL or TLS handshake TLSPaintext
		1765	record without consuming anything. Only SSL version 3 or higher
		1766	is handled, up to the fictituous protocol 4.x (but both SSL3+ and
		1767	SSL2-compatible framing is supported).
		1768
		1769	If it detects that the input data is likely TLS, it calls the callback
		1770	with a true value for C<$detect> and the (on-wire) TLS version as second
		1771	and third argument (C<$major> is C<3>, and C<$minor> is 0..3 for SSL
		1772	3.0, TLS 1.0, 1.1 and 1.2, respectively). If it detects the input to
		1773	be definitely not TLS, it calls the callback with a false value for
		1774	C<$detect>.
		1775
		1776	The callback could use this information to decide whether or not to start
		1777	TLS negotiation.
		1778
		1779	In all cases the data read so far is passed to the following read
		1780	handlers.
		1781
		1782	Usually you want to use the C<tls_autostart> read type instead.
		1783
		1784	If you want to design a protocol that works in the presence of TLS
		1785	dtection, make sure that any non-TLS data doesn't start with the octet 22
		1786	(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
		1787	read type does are a bit more strict, but might losen in the future to
		1788	accomodate protocol changes.
		1789
		1790	This read type does not rely on L<AnyEvent::TLS> (and thus, not on
		1791	L<Net::SSLeay>).
		1792
		1793	=item tls_autostart => $tls[, $tls_ctx]
		1794
		1795	Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
		1796	to start tls by calling C<starttls> with the given arguments.
		1797
		1798	In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
		1799	been configured to accept, as servers do not normally send a handshake on
		1800	their own and ths cannot be detected in this way.
		1801
		1802	See C<tls_detect> above for more details.
		1803
		1804	Example: give the client a chance to start TLS before accepting a text
		1805	line.
		1806
		1807	$hdl->push_read (tls_detect => "accept");
		1808	$hdl->push_read (line => sub {
		1809	print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
		1810	});
		1811
		1812	=cut
		1813
		1814	register_read_type tls_detect => sub {
		1815	my ($self, $cb) = @_;
		1816
		1817	sub {
		1818	# this regex matches a full or partial tls record
		1819	if (
		1820	# ssl3+: type(22=handshake) major(=3) minor(any) length_hi
		1821	$self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
		1822	# ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
		1823	or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
		1824	) {
		1825	return if 3 != length $1; # partial match, can't decide yet
		1826
		1827	# full match, valid TLS record
		1828	my ($major, $minor) = unpack "CC", $1;
		1829	$cb->($self, "accept", $major + $minor * 0.1);
		1830	} else {
		1831	# mismatch == guaranteed not TLS
		1832	$cb->($self, undef);
		1833	}
		1834
		1835	1
		1836	}
		1837	};
		1838
		1839	register_read_type tls_autostart => sub {
		1840	my ($self, @tls) = @_;
		1841
		1842	$RH{tls_detect}($self, sub {
		1843	return unless $_[1];
		1844	$_[0]->starttls (@tls);
		1845	})
		1846	};
		1847
733	=back	1848	=back
734		1849
735	=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args)	1850	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
736		1851
737	This function (not method) lets you add your own types to C<push_read>.	1852	Instead of one of the predefined types, you can also specify the name
		1853	of a package. AnyEvent will try to load the package and then expects to
		1854	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1855	progressively tries to load the parent package until it either finds the
		1856	function (good) or runs out of packages (bad).
738		1857
739	Whenever the given C<type> is used, C<push_read> will invoke the code	1858	Whenever this type is used, C<push_read> will invoke the function with the
740	reference with the handle object, the callback and the remaining	1859	handle object, the original callback and the remaining arguments.
741	arguments.
742		1860
743	The code reference is supposed to return a callback (usually a closure)	1861	The function is supposed to return a callback (usually a closure) that
744	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1862	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1863	mentally treat the function as a "configurable read type to read callback"
		1864	converter.
745		1865
746	It should invoke the passed callback when it is done reading (remember to	1866	It should invoke the original callback when it is done reading (remember
747	pass C<$self> as first argument as all other callbacks do that).	1867	to pass C<$handle> as first argument as all other callbacks do that,
		1868	although there is no strict requirement on this).
748		1869
749	Note that this is a function, and all types registered this way will be
750	global, so try to use unique names.
751
752	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1870	For examples, see the source of this module (F<perldoc -m
753	search for C<register_read_type>)).	1871	AnyEvent::Handle>, search for C<register_read_type>)).
754		1872
755	=item $handle->stop_read	1873	=item $handle->stop_read
756		1874
757	=item $handle->start_read	1875	=item $handle->start_read
758		1876
759	In rare cases you actually do not want to read anything from the	1877	In rare cases you actually do not want to read anything from the
760	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1878	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761	any queued callbacks will be executed then. To start reading again, call	1879	any queued callbacks will be executed then. To start reading again, call
762	C<start_read>.	1880	C<start_read>.
763		1881
		1882	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1883	you change the C<on_read> callback or push/unshift a read callback, and it
		1884	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1885	there are any read requests in the queue.
		1886
		1887	In older versions of this module (<= 5.3), these methods had no effect,
		1888	as TLS does not support half-duplex connections. In current versions they
		1889	work as expected, as this behaviour is required to avoid certain resource
		1890	attacks, where the program would be forced to read (and buffer) arbitrary
		1891	amounts of data before being able to send some data. The drawback is that
		1892	some readings of the the SSL/TLS specifications basically require this
		1893	attack to be working, as SSL/TLS implementations might stall sending data
		1894	during a rehandshake.
		1895
		1896	As a guideline, during the initial handshake, you should not stop reading,
		1897	and as a client, it might cause problems, depending on your application.
		1898
764	=cut	1899	=cut
765		1900
766	sub stop_read {	1901	sub stop_read {
767	my ($self) = @_;	1902	my ($self) = @_;
768		1903
769	delete $self->{rw};	1904	delete $self->{_rw};
770	}	1905	}
771		1906
772	sub start_read {	1907	sub start_read {
773	my ($self) = @_;	1908	my ($self) = @_;
774		1909
775	unless ($self->{rw} || $self->{eof}) {	1910	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
776	Scalar::Util::weaken $self;	1911	Scalar::Util::weaken $self;
777		1912
778	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1913	$self->{_rw} = AE::io $self->{fh}, 0, sub {
779	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1914	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1915	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
781		1916
782	if ($len > 0) {	1917	if ($len > 0) {
783	$self->{filter_r}	1918	$self->{_activity} = $self->{_ractivity} = AE::now;
784	? $self->{filter_r}->($self, $rbuf)	1919
		1920	if ($self->{tls}) {
		1921	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1922
		1923	&_dotls ($self);
		1924	} else {
785	: $self->_drain_rbuf;	1925	$self->_drain_rbuf;
		1926	}
		1927
		1928	if ($len == $self->{read_size}) {
		1929	$self->{read_size} *= 2;
		1930	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1931	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1932	}
786		1933
787	} elsif (defined $len) {	1934	} elsif (defined $len) {
788	delete $self->{rw};	1935	delete $self->{_rw};
789	$self->{eof} = 1;	1936	$self->{_eof} = 1;
790	$self->_drain_rbuf;	1937	$self->_drain_rbuf;
791		1938
792	} elsif ($! != EAGAIN && $! != EINTR) {	1939	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793	return $self->error;	1940	return $self->_error ($!, 1);
794	}	1941	}
795	});	1942	};
796	}	1943	}
797	}	1944	}
798		1945
		1946	our $ERROR_SYSCALL;
		1947	our $ERROR_WANT_READ;
		1948
		1949	sub _tls_error {
		1950	my ($self, $err) = @_;
		1951
		1952	return $self->_error ($!, 1)
		1953	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1954
		1955	my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1956
		1957	# reduce error string to look less scary
		1958	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1959
		1960	if ($self->{_on_starttls}) {
		1961	(delete $self->{_on_starttls})->($self, undef, $err);
		1962	&_freetls;
		1963	} else {
		1964	&_freetls;
		1965	$self->_error (Errno::EPROTO, 1, $err);
		1966	}
		1967	}
		1968
		1969	# poll the write BIO and send the data if applicable
		1970	# also decode read data if possible
		1971	# this is basiclaly our TLS state machine
		1972	# more efficient implementations are possible with openssl,
		1973	# but not with the buggy and incomplete Net::SSLeay.
799	sub _dotls {	1974	sub _dotls {
800	my ($self) = @_;	1975	my ($self) = @_;
801		1976
		1977	my $tmp;
		1978
802	if (length $self->{tls_wbuf}) {	1979	if (length $self->{_tls_wbuf}) {
803	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1980	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804	substr $self->{tls_wbuf}, 0, $len, "";	1981	substr $self->{_tls_wbuf}, 0, $tmp, "";
805	}	1982	}
806	}
807		1983
		1984	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1985	return $self->_tls_error ($tmp)
		1986	if $tmp != $ERROR_WANT_READ
		1987	&& ($tmp != $ERROR_SYSCALL || $!);
		1988	}
		1989
808	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1990	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1991	unless (length $tmp) {
		1992	$self->{_on_starttls}
		1993	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1994	&_freetls;
		1995
		1996	if ($self->{on_stoptls}) {
		1997	$self->{on_stoptls}($self);
		1998	return;
		1999	} else {
		2000	# let's treat SSL-eof as we treat normal EOF
		2001	delete $self->{_rw};
		2002	$self->{_eof} = 1;
		2003	}
		2004	}
		2005
		2006	$self->{_tls_rbuf} .= $tmp;
		2007	$self->_drain_rbuf;
		2008	$self->{tls} or return; # tls session might have gone away in callback
		2009	}
		2010
		2011	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		2012	return $self->_tls_error ($tmp)
		2013	if $tmp != $ERROR_WANT_READ
		2014	&& ($tmp != $ERROR_SYSCALL || $!);
		2015
		2016	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809	$self->{wbuf} .= $buf;	2017	$self->{wbuf} .= $tmp;
810	$self->_drain_wbuf;	2018	$self->_drain_wbuf;
		2019	$self->{tls} or return; # tls session might have gone away in callback
811	}	2020	}
812		2021
813	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {	2022	$self->{_on_starttls}
814	$self->{rbuf} .= $buf;	2023	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
815	$self->_drain_rbuf;	2024	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
816	}
817
818	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
819
820	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
821	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
822	$self->error;
823	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
824	$! = &Errno::EIO;
825	$self->error;
826	}
827
828	# all others are fine for our purposes
829	}
830	}	2025	}
831		2026
832	=item $handle->starttls ($tls[, $tls_ctx])	2027	=item $handle->starttls ($tls[, $tls_ctx])
833		2028
834	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	2029	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
835	object is created, you can also do that at a later time by calling	2030	object is created, you can also do that at a later time by calling
836	C<starttls>.	2031	C<starttls>. See the C<tls> constructor argument for general info.
		2032
		2033	Starting TLS is currently an asynchronous operation - when you push some
		2034	write data and then call C<< ->starttls >> then TLS negotiation will start
		2035	immediately, after which the queued write data is then sent. This might
		2036	change in future versions, so best make sure you have no outstanding write
		2037	data when calling this method.
837		2038
838	The first argument is the same as the C<tls> constructor argument (either	2039	The first argument is the same as the C<tls> constructor argument (either
839	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	2040	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840		2041
841	The second argument is the optional C<Net::SSLeay::CTX> object that is	2042	The second argument is the optional C<AnyEvent::TLS> object that is used
842	used when AnyEvent::Handle has to create its own TLS connection object.	2043	when AnyEvent::Handle has to create its own TLS connection object, or
		2044	a hash reference with C<< key => value >> pairs that will be used to
		2045	construct a new context.
843		2046
844	=cut	2047	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		2048	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		2049	changed to your liking. Note that the handshake might have already started
		2050	when this function returns.
845		2051
846	# TODO: maybe document...	2052	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		2053	handshakes on the same stream. It is best to not attempt to use the
		2054	stream after stopping TLS.
		2055
		2056	This method may invoke callbacks (and therefore the handle might be
		2057	destroyed after it returns).
		2058
		2059	=cut
		2060
		2061	our %TLS_CACHE; #TODO not yet documented, should we?
		2062
847	sub starttls {	2063	sub starttls {
848	my ($self, $ssl, $ctx) = @_;	2064	my ($self, $tls, $ctx) = @_;
849		2065
850	$self->stoptls;	2066	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		2067	if $self->{tls};
851		2068
852	if ($ssl eq "accept") {	2069	unless (defined $AnyEvent::TLS::VERSION) {
853	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	2070	eval {
854	Net::SSLeay::set_accept_state ($ssl);	2071	require Net::SSLeay;
855	} elsif ($ssl eq "connect") {	2072	require AnyEvent::TLS;
856	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	2073	1
857	Net::SSLeay::set_connect_state ($ssl);	2074	} or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
		2075	}
		2076
		2077	$self->{tls} = $tls;
		2078	$self->{tls_ctx} = $ctx if @_ > 2;
		2079
		2080	return unless $self->{fh};
		2081
		2082	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		2083	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		2084
		2085	$tls = delete $self->{tls};
		2086	$ctx = $self->{tls_ctx};
		2087
		2088	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		2089
		2090	if ("HASH" eq ref $ctx) {
		2091	if ($ctx->{cache}) {
		2092	my $key = $ctx+0;
		2093	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		2094	} else {
		2095	$ctx = new AnyEvent::TLS %$ctx;
		2096	}
		2097	}
858	}	2098
859		2099	$self->{tls_ctx} = $ctx || TLS_CTX ();
860	$self->{tls} = $ssl;	2100	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
861		2101
862	# basically, this is deep magic (because SSL_read should have the same issues)	2102	# basically, this is deep magic (because SSL_read should have the same issues)
863	# but the openssl maintainers basically said: "trust us, it just works".	2103	# but the openssl maintainers basically said: "trust us, it just works".
864	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	2104	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
865	# and mismaintained ssleay-module doesn't even offer them).	2105	# and mismaintained ssleay-module doesn't even offer them).
866	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	2106	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		2107	#
		2108	# in short: this is a mess.
		2109	#
		2110	# note that we do not try to keep the length constant between writes as we are required to do.
		2111	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		2112	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2113	# have identity issues in that area.
867	Net::SSLeay::CTX_set_mode ($self->{tls},	2114	# Net::SSLeay::CTX_set_mode ($ssl,
868	(eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2115	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869	| (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2116	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2117	Net::SSLeay::CTX_set_mode ($tls, 1|2);
870		2118
871	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2119	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2120	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873		2121
		2122	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2123	$self->{rbuf} = "";
		2124
874	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	2125	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
875		2126
876	$self->{filter_w} = sub {	2127	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
877	$_[0]{tls_wbuf} .= ${$_[1]};	2128	if $self->{on_starttls};
878	&_dotls;	2129
879	};	2130	&_dotls; # need to trigger the initial handshake
880	$self->{filter_r} = sub {	2131	$self->start_read; # make sure we actually do read
881	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882	&_dotls;
883	};
884	}	2132	}
885		2133
886	=item $handle->stoptls	2134	=item $handle->stoptls
887		2135
888	Destroys the SSL connection, if any. Partial read or write data will be	2136	Shuts down the SSL connection - this makes a proper EOF handshake by
889	lost.	2137	sending a close notify to the other side, but since OpenSSL doesn't
		2138	support non-blocking shut downs, it is not guaranteed that you can re-use
		2139	the stream afterwards.
		2140
		2141	This method may invoke callbacks (and therefore the handle might be
		2142	destroyed after it returns).
890		2143
891	=cut	2144	=cut
892		2145
893	sub stoptls {	2146	sub stoptls {
894	my ($self) = @_;	2147	my ($self) = @_;
895		2148
896	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2149	if ($self->{tls} && $self->{fh}) {
897	delete $self->{tls_rbio};	2150	Net::SSLeay::shutdown ($self->{tls});
898	delete $self->{tls_wbio};	2151
899	delete $self->{tls_wbuf};	2152	&_dotls;
900	delete $self->{filter_r};	2153
901	delete $self->{filter_w};	2154	# # we don't give a shit. no, we do, but we can't. no...#d#
		2155	# # we, we... have to use openssl :/#d#
		2156	# &_freetls;#d#
		2157	}
902	}	2158	}
		2159
		2160	sub _freetls {
		2161	my ($self) = @_;
		2162
		2163	return unless $self->{tls};
		2164
		2165	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2166	if $self->{tls} > 0;
		2167
		2168	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2169	}
		2170
		2171	=item $handle->resettls
		2172
		2173	This rarely-used method simply resets and TLS state on the handle, usually
		2174	causing data loss.
		2175
		2176	One case where it may be useful is when you want to skip over the data in
		2177	the stream but you are not interested in interpreting it, so data loss is
		2178	no concern.
		2179
		2180	=cut
		2181
		2182	*resettls = \&_freetls;
903		2183
904	sub DESTROY {	2184	sub DESTROY {
905	my $self = shift;	2185	my ($self) = @_;
906		2186
907	$self->stoptls;	2187	&_freetls;
		2188
		2189	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2190
		2191	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2192	my $fh = delete $self->{fh};
		2193	my $wbuf = delete $self->{wbuf};
		2194
		2195	my @linger;
		2196
		2197	push @linger, AE::io $fh, 1, sub {
		2198	my $len = syswrite $fh, $wbuf, length $wbuf;
		2199
		2200	if ($len > 0) {
		2201	substr $wbuf, 0, $len, "";
		2202	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
		2203	@linger = (); # end
		2204	}
		2205	};
		2206	push @linger, AE::timer $linger, 0, sub {
		2207	@linger = ();
		2208	};
		2209	}
908	}	2210	}
		2211
		2212	=item $handle->destroy
		2213
		2214	Shuts down the handle object as much as possible - this call ensures that
		2215	no further callbacks will be invoked and as many resources as possible
		2216	will be freed. Any method you will call on the handle object after
		2217	destroying it in this way will be silently ignored (and it will return the
		2218	empty list).
		2219
		2220	Normally, you can just "forget" any references to an AnyEvent::Handle
		2221	object and it will simply shut down. This works in fatal error and EOF
		2222	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2223	callback, so when you want to destroy the AnyEvent::Handle object from
		2224	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2225	that case.
		2226
		2227	Destroying the handle object in this way has the advantage that callbacks
		2228	will be removed as well, so if those are the only reference holders (as
		2229	is common), then one doesn't need to do anything special to break any
		2230	reference cycles.
		2231
		2232	The handle might still linger in the background and write out remaining
		2233	data, as specified by the C<linger> option, however.
		2234
		2235	=cut
		2236
		2237	sub destroy {
		2238	my ($self) = @_;
		2239
		2240	$self->DESTROY;
		2241	%$self = ();
		2242	bless $self, "AnyEvent::Handle::destroyed";
		2243	}
		2244
		2245	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2246	#nop
		2247	}
		2248
		2249	=item $handle->destroyed
		2250
		2251	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2252	->destroy >>, true otherwise.
		2253
		2254	Can be useful to decide whether the handle is still valid after some
		2255	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2256	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2257	can destroy the handle, so work can be avoided by checking sometimes:
		2258
		2259	$hdl->starttls ("accept");
		2260	return if $hdl->destroyed;
		2261	$hdl->push_write (...
		2262
		2263	Note that the call to C<push_write> will silently be ignored if the handle
		2264	has been destroyed, so often you can just ignore the possibility of the
		2265	handle being destroyed.
		2266
		2267	=cut
		2268
		2269	sub destroyed { 0 }
		2270	sub AnyEvent::Handle::destroyed::destroyed { 1 }
909		2271
910	=item AnyEvent::Handle::TLS_CTX	2272	=item AnyEvent::Handle::TLS_CTX
911		2273
912	This function creates and returns the Net::SSLeay::CTX object used by	2274	This function creates and returns the AnyEvent::TLS object used by default
913	default for TLS mode.	2275	for TLS mode.
914		2276
915	The context is created like this:	2277	The context is created by calling L<AnyEvent::TLS> without any arguments.
916
917	Net::SSLeay::load_error_strings;
918	Net::SSLeay::SSLeay_add_ssl_algorithms;
919	Net::SSLeay::randomize;
920
921	my $CTX = Net::SSLeay::CTX_new;
922
923	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
924		2278
925	=cut	2279	=cut
926		2280
927	our $TLS_CTX;	2281	our $TLS_CTX;
928		2282
929	sub TLS_CTX() {	2283	sub TLS_CTX() {
930	$TLS_CTX || do {	2284	$TLS_CTX ||= do {
931	require Net::SSLeay;	2285	require AnyEvent::TLS;
932		2286
933	Net::SSLeay::load_error_strings ();	2287	new AnyEvent::TLS
934	Net::SSLeay::SSLeay_add_ssl_algorithms ();
935	Net::SSLeay::randomize ();
936
937	$TLS_CTX = Net::SSLeay::CTX_new ();
938
939	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
940
941	$TLS_CTX
942	}	2288	}
943	}	2289	}
944		2290
945	=back	2291	=back
946		2292
		2293
		2294	=head1 NONFREQUENTLY ASKED QUESTIONS
		2295
		2296	=over 4
		2297
		2298	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2299	still get further invocations!
		2300
		2301	That's because AnyEvent::Handle keeps a reference to itself when handling
		2302	read or write callbacks.
		2303
		2304	It is only safe to "forget" the reference inside EOF or error callbacks,
		2305	from within all other callbacks, you need to explicitly call the C<<
		2306	->destroy >> method.
		2307
		2308	=item Why is my C<on_eof> callback never called?
		2309
		2310	Probably because your C<on_error> callback is being called instead: When
		2311	you have outstanding requests in your read queue, then an EOF is
		2312	considered an error as you clearly expected some data.
		2313
		2314	To avoid this, make sure you have an empty read queue whenever your handle
		2315	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2316	an C<on_read> handler that simply pushes the first read requests in the
		2317	queue.
		2318
		2319	See also the next question, which explains this in a bit more detail.
		2320
		2321	=item How can I serve requests in a loop?
		2322
		2323	Most protocols consist of some setup phase (authentication for example)
		2324	followed by a request handling phase, where the server waits for requests
		2325	and handles them, in a loop.
		2326
		2327	There are two important variants: The first (traditional, better) variant
		2328	handles requests until the server gets some QUIT command, causing it to
		2329	close the connection first (highly desirable for a busy TCP server). A
		2330	client dropping the connection is an error, which means this variant can
		2331	detect an unexpected detection close.
		2332
		2333	To handle this case, always make sure you have a non-empty read queue, by
		2334	pushing the "read request start" handler on it:
		2335
		2336	# we assume a request starts with a single line
		2337	my @start_request; @start_request = (line => sub {
		2338	my ($hdl, $line) = @_;
		2339
		2340	... handle request
		2341
		2342	# push next request read, possibly from a nested callback
		2343	$hdl->push_read (@start_request);
		2344	});
		2345
		2346	# auth done, now go into request handling loop
		2347	# now push the first @start_request
		2348	$hdl->push_read (@start_request);
		2349
		2350	By always having an outstanding C<push_read>, the handle always expects
		2351	some data and raises the C<EPIPE> error when the connction is dropped
		2352	unexpectedly.
		2353
		2354	The second variant is a protocol where the client can drop the connection
		2355	at any time. For TCP, this means that the server machine may run out of
		2356	sockets easier, and in general, it means you cannot distinguish a protocl
		2357	failure/client crash from a normal connection close. Nevertheless, these
		2358	kinds of protocols are common (and sometimes even the best solution to the
		2359	problem).
		2360
		2361	Having an outstanding read request at all times is possible if you ignore
		2362	C<EPIPE> errors, but this doesn't help with when the client drops the
		2363	connection during a request, which would still be an error.
		2364
		2365	A better solution is to push the initial request read in an C<on_read>
		2366	callback. This avoids an error, as when the server doesn't expect data
		2367	(i.e. is idly waiting for the next request, an EOF will not raise an
		2368	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2369	and simpler:
		2370
		2371	# auth done, now go into request handling loop
		2372	$hdl->on_read (sub {
		2373	my ($hdl) = @_;
		2374
		2375	# called each time we receive data but the read queue is empty
		2376	# simply start read the request
		2377
		2378	$hdl->push_read (line => sub {
		2379	my ($hdl, $line) = @_;
		2380
		2381	... handle request
		2382
		2383	# do nothing special when the request has been handled, just
		2384	# let the request queue go empty.
		2385	});
		2386	});
		2387
		2388	=item I get different callback invocations in TLS mode/Why can't I pause
		2389	reading?
		2390
		2391	Unlike, say, TCP, TLS connections do not consist of two independent
		2392	communication channels, one for each direction. Or put differently, the
		2393	read and write directions are not independent of each other: you cannot
		2394	write data unless you are also prepared to read, and vice versa.
		2395
		2396	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2397	callback invocations when you are not expecting any read data - the reason
		2398	is that AnyEvent::Handle always reads in TLS mode.
		2399
		2400	During the connection, you have to make sure that you always have a
		2401	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2402	connection (or when you no longer want to use it) you can call the
		2403	C<destroy> method.
		2404
		2405	=item How do I read data until the other side closes the connection?
		2406
		2407	If you just want to read your data into a perl scalar, the easiest way
		2408	to achieve this is by setting an C<on_read> callback that does nothing,
		2409	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2410	will be in C<$_[0]{rbuf}>:
		2411
		2412	$handle->on_read (sub { });
		2413	$handle->on_eof (undef);
		2414	$handle->on_error (sub {
		2415	my $data = delete $_[0]{rbuf};
		2416	});
		2417
		2418	Note that this example removes the C<rbuf> member from the handle object,
		2419	which is not normally allowed by the API. It is expressly permitted in
		2420	this case only, as the handle object needs to be destroyed afterwards.
		2421
		2422	The reason to use C<on_error> is that TCP connections, due to latencies
		2423	and packets loss, might get closed quite violently with an error, when in
		2424	fact all data has been received.
		2425
		2426	It is usually better to use acknowledgements when transferring data,
		2427	to make sure the other side hasn't just died and you got the data
		2428	intact. This is also one reason why so many internet protocols have an
		2429	explicit QUIT command.
		2430
		2431	=item I don't want to destroy the handle too early - how do I wait until
		2432	all data has been written?
		2433
		2434	After writing your last bits of data, set the C<on_drain> callback
		2435	and destroy the handle in there - with the default setting of
		2436	C<low_water_mark> this will be called precisely when all data has been
		2437	written to the socket:
		2438
		2439	$handle->push_write (...);
		2440	$handle->on_drain (sub {
		2441	AE::log debug => "All data submitted to the kernel.";
		2442	undef $handle;
		2443	});
		2444
		2445	If you just want to queue some data and then signal EOF to the other side,
		2446	consider using C<< ->push_shutdown >> instead.
		2447
		2448	=item I want to contact a TLS/SSL server, I don't care about security.
		2449
		2450	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2451	connect to it and then create the AnyEvent::Handle with the C<tls>
		2452	parameter:
		2453
		2454	tcp_connect $host, $port, sub {
		2455	my ($fh) = @_;
		2456
		2457	my $handle = new AnyEvent::Handle
		2458	fh => $fh,
		2459	tls => "connect",
		2460	on_error => sub { ... };
		2461
		2462	$handle->push_write (...);
		2463	};
		2464
		2465	=item I want to contact a TLS/SSL server, I do care about security.
		2466
		2467	Then you should additionally enable certificate verification, including
		2468	peername verification, if the protocol you use supports it (see
		2469	L<AnyEvent::TLS>, C<verify_peername>).
		2470
		2471	E.g. for HTTPS:
		2472
		2473	tcp_connect $host, $port, sub {
		2474	my ($fh) = @_;
		2475
		2476	my $handle = new AnyEvent::Handle
		2477	fh => $fh,
		2478	peername => $host,
		2479	tls => "connect",
		2480	tls_ctx => { verify => 1, verify_peername => "https" },
		2481	...
		2482
		2483	Note that you must specify the hostname you connected to (or whatever
		2484	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2485	peername verification will be done.
		2486
		2487	The above will use the system-dependent default set of trusted CA
		2488	certificates. If you want to check against a specific CA, add the
		2489	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2490
		2491	tls_ctx => {
		2492	verify => 1,
		2493	verify_peername => "https",
		2494	ca_file => "my-ca-cert.pem",
		2495	},
		2496
		2497	=item I want to create a TLS/SSL server, how do I do that?
		2498
		2499	Well, you first need to get a server certificate and key. You have
		2500	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2501	self-signed certificate (cheap. check the search engine of your choice,
		2502	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2503	nice program for that purpose).
		2504
		2505	Then create a file with your private key (in PEM format, see
		2506	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2507	file should then look like this:
		2508
		2509	-----BEGIN RSA PRIVATE KEY-----
		2510	...header data
		2511	... lots of base64'y-stuff
		2512	-----END RSA PRIVATE KEY-----
		2513
		2514	-----BEGIN CERTIFICATE-----
		2515	... lots of base64'y-stuff
		2516	-----END CERTIFICATE-----
		2517
		2518	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2519	specify this file as C<cert_file>:
		2520
		2521	tcp_server undef, $port, sub {
		2522	my ($fh) = @_;
		2523
		2524	my $handle = new AnyEvent::Handle
		2525	fh => $fh,
		2526	tls => "accept",
		2527	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2528	...
		2529
		2530	When you have intermediate CA certificates that your clients might not
		2531	know about, just append them to the C<cert_file>.
		2532
		2533	=back
		2534
		2535	=head1 SUBCLASSING AnyEvent::Handle
		2536
		2537	In many cases, you might want to subclass AnyEvent::Handle.
		2538
		2539	To make this easier, a given version of AnyEvent::Handle uses these
		2540	conventions:
		2541
		2542	=over 4
		2543
		2544	=item * all constructor arguments become object members.
		2545
		2546	At least initially, when you pass a C<tls>-argument to the constructor it
		2547	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2548	mutated later on (for example C<tls> will hold the TLS connection object).
		2549
		2550	=item * other object member names are prefixed with an C<_>.
		2551
		2552	All object members not explicitly documented (internal use) are prefixed
		2553	with an underscore character, so the remaining non-C<_>-namespace is free
		2554	for use for subclasses.
		2555
		2556	=item * all members not documented here and not prefixed with an underscore
		2557	are free to use in subclasses.
		2558
		2559	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2560	member variables, but that's just life. At least it is documented.
		2561
		2562	=back
		2563
947	=head1 AUTHOR	2564	=head1 AUTHOR
948		2565
949	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2566	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950		2567
951	=cut	2568	=cut
952		2569
953	1; # End of AnyEvent::Handle	2570	1
		2571

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