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Revision 1.220 by root, Sun Jul 24 13:10:43 2011 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict qw(subs vars);
5
6	use AnyEvent ();
7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
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 = 4.233;
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	warn "got error $msg\n";
		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	warn "got line <$line>\n";
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
54	The L<AnyEvent::Intro> tutorial contains some well-documented	38	The L<AnyEvent::Intro> tutorial contains some well-documented
55	AnyEvent::Handle examples.	39	AnyEvent::Handle examples.
56		40
57	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
58	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
59	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.
60		47
61	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
62	argument.	49	argument.
63		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
64	=head1 METHODS	82	=head1 METHODS
65		83
66	=over 4	84	=over 4
67		85
68	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
69		87
70	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
71		89
72	=over 4	90	=over 4
73		91
74	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
75		93
76	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
77
78	NOTE: The filehandle will be set to non-blocking mode (using	95	NOTE: The filehandle will be set to non-blocking mode (using
79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80	that mode.	97	that mode.
81		98
		99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		100
		101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
		104
		105	You have to specify either this parameter, or C<fh>, above.
		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
82	=item on_eof => $cb->($handle)	116	=item on_prepare => $cb->($handle)
83		117
84	Set the callback to be called when an end-of-file condition is detected,	118	This (rarely used) callback is called before a new connection is
85	i.e. in the case of a socket, when the other side has closed the	119	attempted, but after the file handle has been created (you can access that
86	connection cleanly.	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).
87		123
88	For sockets, this just means that the other side has stopped sending data,	124	The return value of this callback should be the connect timeout value in
89	you can still try to write data, and, in fact, one can return from the eof	125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
90	callback and continue writing data, as only the read part has been shut	126	default timeout is to be used).
91	down.
92		127
93	While not mandatory, it is I<highly> recommended to set an eof callback,	128	=item on_connect => $cb->($handle, $host, $port, $retry->())
94	otherwise you might end up with a closed socket while you are still
95	waiting for data.
96		129
97	If an EOF condition has been detected but no C<on_eof> callback has been	130	This callback is called when a connection has been successfully established.
98	set, then a fatal error will be raised with C<$!> set to <0>.
99		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback.
		134
		135	If, for some reason, the handle is not acceptable, calling C<$retry>
		136	will continue with the next connection target (in case of multi-homed
		137	hosts or SRV records there can be multiple connection endpoints). At the
		138	time it is called the read and write queues, eof status, tls status and
		139	similar properties of the handle will have been reset.
		140
		141	In most cases, you should ignore the C<$retry> parameter.
		142
		143	=item on_connect_error => $cb->($handle, $message)
		144
		145	This callback is called when the connection could not be
		146	established. C<$!> will contain the relevant error code, and C<$message> a
		147	message describing it (usually the same as C<"$!">).
		148
		149	If this callback isn't specified, then C<on_error> will be called with a
		150	fatal error instead.
		151
		152	=back
		153
100	=item on_error => $cb->($handle, $fatal)	154	=item on_error => $cb->($handle, $fatal, $message)
101		155
102	This is the error callback, which is called when, well, some error	156	This is the error callback, which is called when, well, some error
103	occured, such as not being able to resolve the hostname, failure to	157	occured, such as not being able to resolve the hostname, failure to
104	connect or a read error.	158	connect, or a read error.
105		159
106	Some errors are fatal (which is indicated by C<$fatal> being true). On	160	Some errors are fatal (which is indicated by C<$fatal> being true). On
107	fatal errors the handle object will be shut down and will not be usable	161	fatal errors the handle object will be destroyed (by a call to C<< ->
108	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal	162	destroy >>) after invoking the error callback (which means you are free to
109	errors are an EOF condition with active (but unsatisifable) read watchers	163	examine the handle object). Examples of fatal errors are an EOF condition
110	(C<EPIPE>) or I/O errors.	164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
111		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
112	Non-fatal errors can be retried by simply returning, but it is recommended	173	Non-fatal errors can be retried by returning, but it is recommended
113	to simply ignore this parameter and instead abondon the handle object	174	to simply ignore this parameter and instead abondon the handle object
114	when this callback is invoked. Examples of non-fatal errors are timeouts	175	when this callback is invoked. Examples of non-fatal errors are timeouts
115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).	176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
116		177
117	On callback entrance, the value of C<$!> contains the operating system	178	On entry to the callback, the value of C<$!> contains the operating
118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).	179	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		180	C<EPROTO>).
119		181
120	While not mandatory, it is I<highly> recommended to set this callback, as	182	While not mandatory, it is I<highly> recommended to set this callback, as
121	you will not be notified of errors otherwise. The default simply calls	183	you will not be notified of errors otherwise. The default just calls
122	C<croak>.	184	C<croak>.
123		185
124	=item on_read => $cb->($handle)	186	=item on_read => $cb->($handle)
125		187
126	This sets the default read callback, which is called when data arrives	188	This sets the default read callback, which is called when data arrives
127	and no read request is in the queue (unlike read queue callbacks, this	189	and no read request is in the queue (unlike read queue callbacks, this
128	callback will only be called when at least one octet of data is in the	190	callback will only be called when at least one octet of data is in the
129	read buffer).	191	read buffer).
130		192
131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	193	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
132	method or access the C<$handle->{rbuf}> member directly.	194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
133		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
134	When an EOF condition is detected then AnyEvent::Handle will first try to	201	When an EOF condition is detected, AnyEvent::Handle will first try to
135	feed all the remaining data to the queued callbacks and C<on_read> before	202	feed all the remaining data to the queued callbacks and C<on_read> before
136	calling the C<on_eof> callback. If no progress can be made, then a fatal	203	calling the C<on_eof> callback. If no progress can be made, then a fatal
137	error will be raised (with C<$!> set to C<EPIPE>).	204	error will be raised (with C<$!> set to C<EPIPE>).
138		205
		206	Note that, unlike requests in the read queue, an C<on_read> callback
		207	doesn't mean you I<require> some data: if there is an EOF and there
		208	are outstanding read requests then an error will be flagged. With an
		209	C<on_read> callback, the C<on_eof> callback will be invoked.
		210
		211	=item on_eof => $cb->($handle)
		212
		213	Set the callback to be called when an end-of-file condition is detected,
		214	i.e. in the case of a socket, when the other side has closed the
		215	connection cleanly, and there are no outstanding read requests in the
		216	queue (if there are read requests, then an EOF counts as an unexpected
		217	connection close and will be flagged as an error).
		218
		219	For sockets, this just means that the other side has stopped sending data,
		220	you can still try to write data, and, in fact, one can return from the EOF
		221	callback and continue writing data, as only the read part has been shut
		222	down.
		223
		224	If an EOF condition has been detected but no C<on_eof> callback has been
		225	set, then a fatal error will be raised with C<$!> set to <0>.
		226
139	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
140		228
141	This sets the callback that is called when the write buffer becomes empty	229	This sets the callback that is called when the write buffer becomes empty
142	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
143		231
144	To append to the write buffer, use the C<< ->push_write >> method.	232	To append to the write buffer, use the C<< ->push_write >> method.
145		233
146	This callback is useful when you don't want to put all of your write data	234	This callback is useful when you don't want to put all of your write data
147	into the queue at once, for example, when you want to write the contents	235	into the queue at once, for example, when you want to write the contents
…		…
149	memory and push it into the queue, but instead only read more data from	237	memory and push it into the queue, but instead only read more data from
150	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
151		239
152	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
153		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
154	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
155	seconds pass without a successful read or write on the underlying file	247	many seconds pass without a successful read or write on the underlying
156	handle, the C<on_timeout> callback will be invoked (and if that one is	248	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
157	missing, a non-fatal C<ETIMEDOUT> error will be raised).	249	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		250	error will be raised).
158		251
		252	There are three variants of the timeouts that work independently of each
		253	other, for both read and write (triggered when nothing was read I<OR>
		254	written), just read (triggered when nothing was read), and just write:
		255	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		256	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		257	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		258
159	Note that timeout processing is also active when you currently do not have	259	Note that timeout processing is active even when you do not have any
160	any outstanding read or write requests: If you plan to keep the connection	260	outstanding read or write requests: If you plan to keep the connection
161	idle then you should disable the timout temporarily or ignore the timeout	261	idle then you should disable the timeout temporarily or ignore the
162	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply	262	timeout in the corresponding C<on_timeout> callback, in which case
163	restart the timeout.	263	AnyEvent::Handle will simply restart the timeout.
164		264
165	Zero (the default) disables this timeout.	265	Zero (the default) disables the corresponding timeout.
166		266
167	=item on_timeout => $cb->($handle)	267	=item on_timeout => $cb->($handle)
		268
		269	=item on_rtimeout => $cb->($handle)
		270
		271	=item on_wtimeout => $cb->($handle)
168		272
169	Called whenever the inactivity timeout passes. If you return from this	273	Called whenever the inactivity timeout passes. If you return from this
170	callback, then the timeout will be reset as if some activity had happened,	274	callback, then the timeout will be reset as if some activity had happened,
171	so this condition is not fatal in any way.	275	so this condition is not fatal in any way.
172		276
…		…
180	be configured to accept only so-and-so much data that it cannot act on	284	be configured to accept only so-and-so much data that it cannot act on
181	(for example, when expecting a line, an attacker could send an unlimited	285	(for example, when expecting a line, an attacker could send an unlimited
182	amount of data without a callback ever being called as long as the line	286	amount of data without a callback ever being called as long as the line
183	isn't finished).	287	isn't finished).
184		288
		289	=item wbuf_max => <bytes>
		290
		291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		292	when the write buffer ever (strictly) exceeds this size. This is useful to
		293	avoid some forms of denial-of-service attacks.
		294
		295	Although the units of this parameter is bytes, this is the I<raw> number
		296	of bytes not yet accepted by the kernel. This can make a difference when
		297	you e.g. use TLS, as TLS typically makes your write data larger (but it
		298	can also make it smaller due to compression).
		299
		300	As an example of when this limit is useful, take a chat server that sends
		301	chat messages to a client. If the client does not read those in a timely
		302	manner then the send buffer in the server would grow unbounded.
		303
185	=item autocork => <boolean>	304	=item autocork => <boolean>
186		305
187	When disabled (the default), then C<push_write> will try to immediately	306	When disabled (the default), C<push_write> will try to immediately
188	write the data to the handle, if possible. This avoids having to register	307	write the data to the handle if possible. This avoids having to register
189	a write watcher and wait for the next event loop iteration, but can	308	a write watcher and wait for the next event loop iteration, but can
190	be inefficient if you write multiple small chunks (on the wire, this	309	be inefficient if you write multiple small chunks (on the wire, this
191	disadvantage is usually avoided by your kernel's nagle algorithm, see	310	disadvantage is usually avoided by your kernel's nagle algorithm, see
192	C<no_delay>, but this option can save costly syscalls).	311	C<no_delay>, but this option can save costly syscalls).
193		312
194	When enabled, then writes will always be queued till the next event loop	313	When enabled, writes will always be queued till the next event loop
195	iteration. This is efficient when you do many small writes per iteration,	314	iteration. This is efficient when you do many small writes per iteration,
196	but less efficient when you do a single write only per iteration (or when	315	but less efficient when you do a single write only per iteration (or when
197	the write buffer often is full). It also increases write latency.	316	the write buffer often is full). It also increases write latency.
198		317
199	=item no_delay => <boolean>	318	=item no_delay => <boolean>
…		…
203	the Nagle algorithm, and usually it is beneficial.	322	the Nagle algorithm, and usually it is beneficial.
204		323
205	In some situations you want as low a delay as possible, which can be	324	In some situations you want as low a delay as possible, which can be
206	accomplishd by setting this option to a true value.	325	accomplishd by setting this option to a true value.
207		326
208	The default is your opertaing system's default behaviour (most likely	327	The default is your operating system's default behaviour (most likely
209	enabled), this option explicitly enables or disables it, if possible.	328	enabled). This option explicitly enables or disables it, if possible.
		329
		330	=item keepalive => <boolean>
		331
		332	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		333	normally, TCP connections have no time-out once established, so TCP
		334	connections, once established, can stay alive forever even when the other
		335	side has long gone. TCP keepalives are a cheap way to take down long-lived
		336	TCP connections when the other side becomes unreachable. While the default
		337	is OS-dependent, TCP keepalives usually kick in after around two hours,
		338	and, if the other side doesn't reply, take down the TCP connection some 10
		339	to 15 minutes later.
		340
		341	It is harmless to specify this option for file handles that do not support
		342	keepalives, and enabling it on connections that are potentially long-lived
		343	is usually a good idea.
		344
		345	=item oobinline => <boolean>
		346
		347	BSD majorly fucked up the implementation of TCP urgent data. The result
		348	is that almost no OS implements TCP according to the specs, and every OS
		349	implements it slightly differently.
		350
		351	If you want to handle TCP urgent data, then setting this flag (the default
		352	is enabled) gives you the most portable way of getting urgent data, by
		353	putting it into the stream.
		354
		355	Since BSD emulation of OOB data on top of TCP's urgent data can have
		356	security implications, AnyEvent::Handle sets this flag automatically
		357	unless explicitly specified. Note that setting this flag after
		358	establishing a connection I<may> be a bit too late (data loss could
		359	already have occured on BSD systems), but at least it will protect you
		360	from most attacks.
210		361
211	=item read_size => <bytes>	362	=item read_size => <bytes>
212		363
213	The default read block size (the amount of bytes this module will	364	The initial read block size, the number of bytes this module will try to
214	try to read during each loop iteration, which affects memory	365	read during each loop iteration. Each handle object will consume at least
215	requirements). Default: C<8192>.	366	this amount of memory for the read buffer as well, so when handling many
		367	connections requirements). See also C<max_read_size>. Default: C<2048>.
		368
		369	=item max_read_size => <bytes>
		370
		371	The maximum read buffer size used by the dynamic adjustment
		372	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		373	one go it will double C<read_size> up to the maximum given by this
		374	option. Default: C<131072> or C<read_size>, whichever is higher.
216		375
217	=item low_water_mark => <bytes>	376	=item low_water_mark => <bytes>
218		377
219	Sets the amount of bytes (default: C<0>) that make up an "empty" write	378	Sets the number of bytes (default: C<0>) that make up an "empty" write
220	buffer: If the write reaches this size or gets even samller it is	379	buffer: If the buffer reaches this size or gets even samller it is
221	considered empty.	380	considered empty.
222		381
223	Sometimes it can be beneficial (for performance reasons) to add data to	382	Sometimes it can be beneficial (for performance reasons) to add data to
224	the write buffer before it is fully drained, but this is a rare case, as	383	the write buffer before it is fully drained, but this is a rare case, as
225	the operating system kernel usually buffers data as well, so the default	384	the operating system kernel usually buffers data as well, so the default
226	is good in almost all cases.	385	is good in almost all cases.
227		386
228	=item linger => <seconds>	387	=item linger => <seconds>
229		388
230	If non-zero (default: C<3600>), then the destructor of the	389	If this is non-zero (default: C<3600>), the destructor of the
231	AnyEvent::Handle object will check whether there is still outstanding	390	AnyEvent::Handle object will check whether there is still outstanding
232	write data and will install a watcher that will write this data to the	391	write data and will install a watcher that will write this data to the
233	socket. No errors will be reported (this mostly matches how the operating	392	socket. No errors will be reported (this mostly matches how the operating
234	system treats outstanding data at socket close time).	393	system treats outstanding data at socket close time).
235		394
236	This will not work for partial TLS data that could not be encoded	395	This will not work for partial TLS data that could not be encoded
237	yet. This data will be lost.	396	yet. This data will be lost. Calling the C<stoptls> method in time might
		397	help.
		398
		399	=item peername => $string
		400
		401	A string used to identify the remote site - usually the DNS hostname
		402	(I<not> IDN!) used to create the connection, rarely the IP address.
		403
		404	Apart from being useful in error messages, this string is also used in TLS
		405	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		406	verification will be skipped when C<peername> is not specified or is
		407	C<undef>.
238		408
239	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	409	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
240		410
241	When this parameter is given, it enables TLS (SSL) mode, that means	411	When this parameter is given, it enables TLS (SSL) mode, that means
242	AnyEvent will start a TLS handshake as soon as the conenction has been	412	AnyEvent will start a TLS handshake as soon as the connection has been
243	established and will transparently encrypt/decrypt data afterwards.	413	established and will transparently encrypt/decrypt data afterwards.
		414
		415	All TLS protocol errors will be signalled as C<EPROTO>, with an
		416	appropriate error message.
244		417
245	TLS mode requires Net::SSLeay to be installed (it will be loaded	418	TLS mode requires Net::SSLeay to be installed (it will be loaded
246	automatically when you try to create a TLS handle): this module doesn't	419	automatically when you try to create a TLS handle): this module doesn't
247	have a dependency on that module, so if your module requires it, you have	420	have a dependency on that module, so if your module requires it, you have
248	to add the dependency yourself.	421	to add the dependency yourself.
…		…
252	mode.	425	mode.
253		426
254	You can also provide your own TLS connection object, but you have	427	You can also provide your own TLS connection object, but you have
255	to make sure that you call either C<Net::SSLeay::set_connect_state>	428	to make sure that you call either C<Net::SSLeay::set_connect_state>
256	or C<Net::SSLeay::set_accept_state> on it before you pass it to	429	or C<Net::SSLeay::set_accept_state> on it before you pass it to
257	AnyEvent::Handle.	430	AnyEvent::Handle. Also, this module will take ownership of this connection
		431	object.
258		432
		433	At some future point, AnyEvent::Handle might switch to another TLS
		434	implementation, then the option to use your own session object will go
		435	away.
		436
		437	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		438	passing in the wrong integer will lead to certain crash. This most often
		439	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		440	segmentation fault.
		441
259	See the C<< ->starttls >> method for when need to start TLS negotiation later.	442	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
260		443
261	=item tls_ctx => $ssl_ctx	444	=item tls_ctx => $anyevent_tls
262		445
263	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection	446	Use the given C<AnyEvent::TLS> object to create the new TLS connection
264	(unless a connection object was specified directly). If this parameter is	447	(unless a connection object was specified directly). If this
265	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	448	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		449	C<AnyEvent::Handle::TLS_CTX>.
		450
		451	Instead of an object, you can also specify a hash reference with C<< key
		452	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		453	new TLS context object.
		454
		455	=item on_starttls => $cb->($handle, $success[, $error_message])
		456
		457	This callback will be invoked when the TLS/SSL handshake has finished. If
		458	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		459	(C<on_stoptls> will not be called in this case).
		460
		461	The session in C<< $handle->{tls} >> can still be examined in this
		462	callback, even when the handshake was not successful.
		463
		464	TLS handshake failures will not cause C<on_error> to be invoked when this
		465	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		466
		467	Without this callback, handshake failures lead to C<on_error> being
		468	called as usual.
		469
		470	Note that you cannot just call C<starttls> again in this callback. If you
		471	need to do that, start an zero-second timer instead whose callback can
		472	then call C<< ->starttls >> again.
		473
		474	=item on_stoptls => $cb->($handle)
		475
		476	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		477	set, then it will be invoked after freeing the TLS session. If it is not,
		478	then a TLS shutdown condition will be treated like a normal EOF condition
		479	on the handle.
		480
		481	The session in C<< $handle->{tls} >> can still be examined in this
		482	callback.
		483
		484	This callback will only be called on TLS shutdowns, not when the
		485	underlying handle signals EOF.
266		486
267	=item json => JSON or JSON::XS object	487	=item json => JSON or JSON::XS object
268		488
269	This is the json coder object used by the C<json> read and write types.	489	This is the json coder object used by the C<json> read and write types.
270		490
…		…
273	texts.	493	texts.
274		494
275	Note that you are responsible to depend on the JSON module if you want to	495	Note that you are responsible to depend on the JSON module if you want to
276	use this functionality, as AnyEvent does not have a dependency itself.	496	use this functionality, as AnyEvent does not have a dependency itself.
277		497
278	=item filter_r => $cb
279
280	=item filter_w => $cb
281
282	These exist, but are undocumented at this time. (They are used internally
283	by the TLS code).
284
285	=back	498	=back
286		499
287	=cut	500	=cut
288		501
289	sub new {	502	sub new {
290	my $class = shift;	503	my $class = shift;
291
292	my $self = bless { @_ }, $class;	504	my $self = bless { @_ }, $class;
293		505
294	$self->{fh} or Carp::croak "mandatory argument fh is missing";	506	if ($self->{fh}) {
		507	$self->_start;
		508	return unless $self->{fh}; # could be gone by now
		509
		510	} elsif ($self->{connect}) {
		511	require AnyEvent::Socket;
		512
		513	$self->{peername} = $self->{connect}[0]
		514	unless exists $self->{peername};
		515
		516	$self->{_skip_drain_rbuf} = 1;
		517
		518	{
		519	Scalar::Util::weaken (my $self = $self);
		520
		521	$self->{_connect} =
		522	AnyEvent::Socket::tcp_connect (
		523	$self->{connect}[0],
		524	$self->{connect}[1],
		525	sub {
		526	my ($fh, $host, $port, $retry) = @_;
		527
		528	delete $self->{_connect}; # no longer needed
		529
		530	if ($fh) {
		531	$self->{fh} = $fh;
		532
		533	delete $self->{_skip_drain_rbuf};
		534	$self->_start;
		535
		536	$self->{on_connect}
		537	and $self->{on_connect}($self, $host, $port, sub {
		538	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		539	$self->{_skip_drain_rbuf} = 1;
		540	&$retry;
		541	});
		542
		543	} else {
		544	if ($self->{on_connect_error}) {
		545	$self->{on_connect_error}($self, "$!");
		546	$self->destroy if $self;
		547	} else {
		548	$self->_error ($!, 1);
		549	}
		550	}
		551	},
		552	sub {
		553	local $self->{fh} = $_[0];
		554
		555	$self->{on_prepare}
		556	? $self->{on_prepare}->($self)
		557	: ()
		558	}
		559	);
		560	}
		561
		562	} else {
		563	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		564	}
		565
		566	$self
		567	}
		568
		569	sub _start {
		570	my ($self) = @_;
		571
		572	# too many clueless people try to use udp and similar sockets
		573	# with AnyEvent::Handle, do them a favour.
		574	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		575	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		576	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
295		577
296	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	578	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
297		579
298	if ($self->{tls}) {	580	$self->{_activity} =
299	require Net::SSLeay;	581	$self->{_ractivity} =
		582	$self->{_wactivity} = AE::now;
		583
		584	$self->{read_size} ||= 2048;
		585	$self->{max_read_size} = $self->{read_size}
		586	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		587
		588	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		589	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		590	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		591
		592	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		593	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		594
		595	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		596
300	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	597	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
301	}	598	if $self->{tls};
302		599
303	$self->{_activity} = AnyEvent->now;
304	$self->_timeout;
305
306	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	600	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
307	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
308		601
309	$self->start_read	602	$self->start_read
310	if $self->{on_read};	603	if $self->{on_read} || @{ $self->{_queue} };
311		604
312	$self	605	$self->_drain_wbuf;
313	}
314
315	sub _shutdown {
316	my ($self) = @_;
317
318	delete $self->{_tw};
319	delete $self->{_rw};
320	delete $self->{_ww};
321	delete $self->{fh};
322
323	$self->stoptls;
324
325	delete $self->{on_read};
326	delete $self->{_queue};
327	}	606	}
328		607
329	sub _error {	608	sub _error {
330	my ($self, $errno, $fatal) = @_;	609	my ($self, $errno, $fatal, $message) = @_;
331
332	$self->_shutdown
333	if $fatal;
334		610
335	$! = $errno;	611	$! = $errno;
		612	$message ||= "$!";
336		613
337	if ($self->{on_error}) {	614	if ($self->{on_error}) {
338	$self->{on_error}($self, $fatal);	615	$self->{on_error}($self, $fatal, $message);
339	} else {	616	$self->destroy if $fatal;
		617	} elsif ($self->{fh} || $self->{connect}) {
		618	$self->destroy;
340	Carp::croak "AnyEvent::Handle uncaught error: $!";	619	Carp::croak "AnyEvent::Handle uncaught error: $message";
341	}	620	}
342	}	621	}
343		622
344	=item $fh = $handle->fh	623	=item $fh = $handle->fh
345		624
…		…
369	$_[0]{on_eof} = $_[1];	648	$_[0]{on_eof} = $_[1];
370	}	649	}
371		650
372	=item $handle->on_timeout ($cb)	651	=item $handle->on_timeout ($cb)
373		652
374	Replace the current C<on_timeout> callback, or disables the callback (but	653	=item $handle->on_rtimeout ($cb)
375	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
376	argument and method.
377		654
378	=cut	655	=item $handle->on_wtimeout ($cb)
379		656
380	sub on_timeout {	657	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
381	$_[0]{on_timeout} = $_[1];	658	callback, or disables the callback (but not the timeout) if C<$cb> =
382	}	659	C<undef>. See the C<timeout> constructor argument and method.
		660
		661	=cut
		662
		663	# see below
383		664
384	=item $handle->autocork ($boolean)	665	=item $handle->autocork ($boolean)
385		666
386	Enables or disables the current autocork behaviour (see C<autocork>	667	Enables or disables the current autocork behaviour (see C<autocork>
387	constructor argument).	668	constructor argument). Changes will only take effect on the next write.
388		669
389	=cut	670	=cut
		671
		672	sub autocork {
		673	$_[0]{autocork} = $_[1];
		674	}
390		675
391	=item $handle->no_delay ($boolean)	676	=item $handle->no_delay ($boolean)
392		677
393	Enables or disables the C<no_delay> setting (see constructor argument of	678	Enables or disables the C<no_delay> setting (see constructor argument of
394	the same name for details).	679	the same name for details).
…		…
396	=cut	681	=cut
397		682
398	sub no_delay {	683	sub no_delay {
399	$_[0]{no_delay} = $_[1];	684	$_[0]{no_delay} = $_[1];
400		685
		686	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		687	if $_[0]{fh};
		688	}
		689
		690	=item $handle->keepalive ($boolean)
		691
		692	Enables or disables the C<keepalive> setting (see constructor argument of
		693	the same name for details).
		694
		695	=cut
		696
		697	sub keepalive {
		698	$_[0]{keepalive} = $_[1];
		699
401	eval {	700	eval {
402	local $SIG{__DIE__};	701	local $SIG{__DIE__};
403	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];	702	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		703	if $_[0]{fh};
404	};	704	};
405	}	705	}
406		706
		707	=item $handle->oobinline ($boolean)
		708
		709	Enables or disables the C<oobinline> setting (see constructor argument of
		710	the same name for details).
		711
		712	=cut
		713
		714	sub oobinline {
		715	$_[0]{oobinline} = $_[1];
		716
		717	eval {
		718	local $SIG{__DIE__};
		719	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		720	if $_[0]{fh};
		721	};
		722	}
		723
		724	=item $handle->keepalive ($boolean)
		725
		726	Enables or disables the C<keepalive> setting (see constructor argument of
		727	the same name for details).
		728
		729	=cut
		730
		731	sub keepalive {
		732	$_[0]{keepalive} = $_[1];
		733
		734	eval {
		735	local $SIG{__DIE__};
		736	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		737	if $_[0]{fh};
		738	};
		739	}
		740
		741	=item $handle->on_starttls ($cb)
		742
		743	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		744
		745	=cut
		746
		747	sub on_starttls {
		748	$_[0]{on_starttls} = $_[1];
		749	}
		750
		751	=item $handle->on_stoptls ($cb)
		752
		753	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		754
		755	=cut
		756
		757	sub on_stoptls {
		758	$_[0]{on_stoptls} = $_[1];
		759	}
		760
		761	=item $handle->rbuf_max ($max_octets)
		762
		763	Configures the C<rbuf_max> setting (C<undef> disables it).
		764
		765	=item $handle->wbuf_max ($max_octets)
		766
		767	Configures the C<wbuf_max> setting (C<undef> disables it).
		768
		769	=cut
		770
		771	sub rbuf_max {
		772	$_[0]{rbuf_max} = $_[1];
		773	}
		774
		775	sub wbuf_max {
		776	$_[0]{wbuf_max} = $_[1];
		777	}
		778
407	#############################################################################	779	#############################################################################
408		780
409	=item $handle->timeout ($seconds)	781	=item $handle->timeout ($seconds)
410		782
		783	=item $handle->rtimeout ($seconds)
		784
		785	=item $handle->wtimeout ($seconds)
		786
411	Configures (or disables) the inactivity timeout.	787	Configures (or disables) the inactivity timeout.
412		788
413	=cut	789	The timeout will be checked instantly, so this method might destroy the
		790	handle before it returns.
414		791
415	sub timeout {	792	=item $handle->timeout_reset
		793
		794	=item $handle->rtimeout_reset
		795
		796	=item $handle->wtimeout_reset
		797
		798	Reset the activity timeout, as if data was received or sent.
		799
		800	These methods are cheap to call.
		801
		802	=cut
		803
		804	for my $dir ("", "r", "w") {
		805	my $timeout = "${dir}timeout";
		806	my $tw = "_${dir}tw";
		807	my $on_timeout = "on_${dir}timeout";
		808	my $activity = "_${dir}activity";
		809	my $cb;
		810
		811	*$on_timeout = sub {
		812	$_[0]{$on_timeout} = $_[1];
		813	};
		814
		815	*$timeout = sub {
416	my ($self, $timeout) = @_;	816	my ($self, $new_value) = @_;
417		817
		818	$new_value >= 0
		819	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		820
418	$self->{timeout} = $timeout;	821	$self->{$timeout} = $new_value;
419	$self->_timeout;	822	delete $self->{$tw}; &$cb;
420	}	823	};
421		824
		825	*{"${dir}timeout_reset"} = sub {
		826	$_[0]{$activity} = AE::now;
		827	};
		828
		829	# main workhorse:
422	# reset the timeout watcher, as neccessary	830	# reset the timeout watcher, as neccessary
423	# also check for time-outs	831	# also check for time-outs
424	sub _timeout {	832	$cb = sub {
425	my ($self) = @_;	833	my ($self) = @_;
426		834
427	if ($self->{timeout}) {	835	if ($self->{$timeout} && $self->{fh}) {
428	my $NOW = AnyEvent->now;	836	my $NOW = AE::now;
429		837
430	# when would the timeout trigger?	838	# when would the timeout trigger?
431	my $after = $self->{_activity} + $self->{timeout} - $NOW;	839	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
432		840
433	# now or in the past already?	841	# now or in the past already?
434	if ($after <= 0) {	842	if ($after <= 0) {
435	$self->{_activity} = $NOW;	843	$self->{$activity} = $NOW;
436		844
437	if ($self->{on_timeout}) {	845	if ($self->{$on_timeout}) {
438	$self->{on_timeout}($self);	846	$self->{$on_timeout}($self);
439	} else {	847	} else {
440	$self->_error (&Errno::ETIMEDOUT);	848	$self->_error (Errno::ETIMEDOUT);
		849	}
		850
		851	# callback could have changed timeout value, optimise
		852	return unless $self->{$timeout};
		853
		854	# calculate new after
		855	$after = $self->{$timeout};
441	}	856	}
442		857
443	# callback could have changed timeout value, optimise	858	Scalar::Util::weaken $self;
444	return unless $self->{timeout};	859	return unless $self; # ->error could have destroyed $self
445		860
446	# calculate new after	861	$self->{$tw} ||= AE::timer $after, 0, sub {
447	$after = $self->{timeout};	862	delete $self->{$tw};
		863	$cb->($self);
		864	};
		865	} else {
		866	delete $self->{$tw};
448	}	867	}
449
450	Scalar::Util::weaken $self;
451	return unless $self; # ->error could have destroyed $self
452
453	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
454	delete $self->{_tw};
455	$self->_timeout;
456	});
457	} else {
458	delete $self->{_tw};
459	}	868	}
460	}	869	}
461		870
462	#############################################################################	871	#############################################################################
463		872
…		…
479	=item $handle->on_drain ($cb)	888	=item $handle->on_drain ($cb)
480		889
481	Sets the C<on_drain> callback or clears it (see the description of	890	Sets the C<on_drain> callback or clears it (see the description of
482	C<on_drain> in the constructor).	891	C<on_drain> in the constructor).
483		892
		893	This method may invoke callbacks (and therefore the handle might be
		894	destroyed after it returns).
		895
484	=cut	896	=cut
485		897
486	sub on_drain {	898	sub on_drain {
487	my ($self, $cb) = @_;	899	my ($self, $cb) = @_;
488		900
489	$self->{on_drain} = $cb;	901	$self->{on_drain} = $cb;
490		902
491	$cb->($self)	903	$cb->($self)
492	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	904	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
493	}	905	}
494		906
495	=item $handle->push_write ($data)	907	=item $handle->push_write ($data)
496		908
497	Queues the given scalar to be written. You can push as much data as you	909	Queues the given scalar to be written. You can push as much data as
498	want (only limited by the available memory), as C<AnyEvent::Handle>	910	you want (only limited by the available memory and C<wbuf_max>), as
499	buffers it independently of the kernel.	911	C<AnyEvent::Handle> buffers it independently of the kernel.
		912
		913	This method may invoke callbacks (and therefore the handle might be
		914	destroyed after it returns).
500		915
501	=cut	916	=cut
502		917
503	sub _drain_wbuf {	918	sub _drain_wbuf {
504	my ($self) = @_;	919	my ($self) = @_;
…		…
508	Scalar::Util::weaken $self;	923	Scalar::Util::weaken $self;
509		924
510	my $cb = sub {	925	my $cb = sub {
511	my $len = syswrite $self->{fh}, $self->{wbuf};	926	my $len = syswrite $self->{fh}, $self->{wbuf};
512		927
513	if ($len >= 0) {	928	if (defined $len) {
514	substr $self->{wbuf}, 0, $len, "";	929	substr $self->{wbuf}, 0, $len, "";
515		930
516	$self->{_activity} = AnyEvent->now;	931	$self->{_activity} = $self->{_wactivity} = AE::now;
517		932
518	$self->{on_drain}($self)	933	$self->{on_drain}($self)
519	if $self->{low_water_mark} >= length $self->{wbuf}	934	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
520	&& $self->{on_drain};	935	&& $self->{on_drain};
521		936
522	delete $self->{_ww} unless length $self->{wbuf};	937	delete $self->{_ww} unless length $self->{wbuf};
523	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	938	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
524	$self->_error ($!, 1);	939	$self->_error ($!, 1);
…		…
527		942
528	# try to write data immediately	943	# try to write data immediately
529	$cb->() unless $self->{autocork};	944	$cb->() unless $self->{autocork};
530		945
531	# if still data left in wbuf, we need to poll	946	# if still data left in wbuf, we need to poll
532	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	947	$self->{_ww} = AE::io $self->{fh}, 1, $cb
533	if length $self->{wbuf};	948	if length $self->{wbuf};
		949
		950	if (
		951	defined $self->{wbuf_max}
		952	&& $self->{wbuf_max} < length $self->{wbuf}
		953	) {
		954	$self->_error (Errno::ENOSPC, 1), return;
		955	}
534	};	956	};
535	}	957	}
536		958
537	our %WH;	959	our %WH;
538		960
		961	# deprecated
539	sub register_write_type($$) {	962	sub register_write_type($$) {
540	$WH{$_[0]} = $_[1];	963	$WH{$_[0]} = $_[1];
541	}	964	}
542		965
543	sub push_write {	966	sub push_write {
544	my $self = shift;	967	my $self = shift;
545		968
546	if (@_ > 1) {	969	if (@_ > 1) {
547	my $type = shift;	970	my $type = shift;
548		971
		972	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
549	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	973	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
550	->($self, @_);	974	->($self, @_);
551	}	975	}
552		976
		977	# we downgrade here to avoid hard-to-track-down bugs,
		978	# and diagnose the problem earlier and better.
		979
553	if ($self->{filter_w}) {	980	if ($self->{tls}) {
554	$self->{filter_w}($self, \$_[0]);	981	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		982	&_dotls ($self) if $self->{fh};
555	} else {	983	} else {
556	$self->{wbuf} .= $_[0];	984	utf8::downgrade $self->{wbuf} .= $_[0];
557	$self->_drain_wbuf;	985	$self->_drain_wbuf if $self->{fh};
558	}	986	}
559	}	987	}
560		988
561	=item $handle->push_write (type => @args)	989	=item $handle->push_write (type => @args)
562		990
563	Instead of formatting your data yourself, you can also let this module do	991	Instead of formatting your data yourself, you can also let this module
564	the job by specifying a type and type-specific arguments.	992	do the job by specifying a type and type-specific arguments. You
		993	can also specify the (fully qualified) name of a package, in which
		994	case AnyEvent tries to load the package and then expects to find the
		995	C<anyevent_write_type> function inside (see "custom write types", below).
565		996
566	Predefined types are (if you have ideas for additional types, feel free to	997	Predefined types are (if you have ideas for additional types, feel free to
567	drop by and tell us):	998	drop by and tell us):
568		999
569	=over 4	1000	=over 4
…		…
576	=cut	1007	=cut
577		1008
578	register_write_type netstring => sub {	1009	register_write_type netstring => sub {
579	my ($self, $string) = @_;	1010	my ($self, $string) = @_;
580		1011
581	sprintf "%d:%s,", (length $string), $string	1012	(length $string) . ":$string,"
582	};	1013	};
583		1014
584	=item packstring => $format, $data	1015	=item packstring => $format, $data
585		1016
586	An octet string prefixed with an encoded length. The encoding C<$format>	1017	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
626	Other languages could read single lines terminated by a newline and pass	1057	Other languages could read single lines terminated by a newline and pass
627	this line into their JSON decoder of choice.	1058	this line into their JSON decoder of choice.
628		1059
629	=cut	1060	=cut
630		1061
		1062	sub json_coder() {
		1063	eval { require JSON::XS; JSON::XS->new->utf8 }
		1064	|| do { require JSON; JSON->new->utf8 }
		1065	}
		1066
631	register_write_type json => sub {	1067	register_write_type json => sub {
632	my ($self, $ref) = @_;	1068	my ($self, $ref) = @_;
633		1069
634	require JSON;	1070	my $json = $self->{json} ||= json_coder;
635		1071
636	$self->{json} ? $self->{json}->encode ($ref)	1072	$json->encode ($ref)
637	: JSON::encode_json ($ref)
638	};	1073	};
639		1074
640	=item storable => $reference	1075	=item storable => $reference
641		1076
642	Freezes the given reference using L<Storable> and writes it to the	1077	Freezes the given reference using L<Storable> and writes it to the
…		…
652	pack "w/a*", Storable::nfreeze ($ref)	1087	pack "w/a*", Storable::nfreeze ($ref)
653	};	1088	};
654		1089
655	=back	1090	=back
656		1091
657	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1092	=item $handle->push_shutdown
658		1093
659	This function (not method) lets you add your own types to C<push_write>.	1094	Sometimes you know you want to close the socket after writing your data
		1095	before it was actually written. One way to do that is to replace your
		1096	C<on_drain> handler by a callback that shuts down the socket (and set
		1097	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1098	replaces the C<on_drain> callback with:
		1099
		1100	sub { shutdown $_[0]{fh}, 1 }
		1101
		1102	This simply shuts down the write side and signals an EOF condition to the
		1103	the peer.
		1104
		1105	You can rely on the normal read queue and C<on_eof> handling
		1106	afterwards. This is the cleanest way to close a connection.
		1107
		1108	This method may invoke callbacks (and therefore the handle might be
		1109	destroyed after it returns).
		1110
		1111	=cut
		1112
		1113	sub push_shutdown {
		1114	my ($self) = @_;
		1115
		1116	delete $self->{low_water_mark};
		1117	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1118	}
		1119
		1120	=item custom write types - Package::anyevent_write_type $handle, @args
		1121
		1122	Instead of one of the predefined types, you can also specify the name of
		1123	a package. AnyEvent will try to load the package and then expects to find
		1124	a function named C<anyevent_write_type> inside. If it isn't found, it
		1125	progressively tries to load the parent package until it either finds the
		1126	function (good) or runs out of packages (bad).
		1127
660	Whenever the given C<type> is used, C<push_write> will invoke the code	1128	Whenever the given C<type> is used, C<push_write> will the function with
661	reference with the handle object and the remaining arguments.	1129	the handle object and the remaining arguments.
662		1130
663	The code reference is supposed to return a single octet string that will	1131	The function is supposed to return a single octet string that will be
664	be appended to the write buffer.	1132	appended to the write buffer, so you cna mentally treat this function as a
		1133	"arguments to on-the-wire-format" converter.
665		1134
666	Note that this is a function, and all types registered this way will be	1135	Example: implement a custom write type C<join> that joins the remaining
667	global, so try to use unique names.	1136	arguments using the first one.
		1137
		1138	$handle->push_write (My::Type => " ", 1,2,3);
		1139
		1140	# uses the following package, which can be defined in the "My::Type" or in
		1141	# the "My" modules to be auto-loaded, or just about anywhere when the
		1142	# My::Type::anyevent_write_type is defined before invoking it.
		1143
		1144	package My::Type;
		1145
		1146	sub anyevent_write_type {
		1147	my ($handle, $delim, @args) = @_;
		1148
		1149	join $delim, @args
		1150	}
668		1151
669	=cut	1152	=cut
670		1153
671	#############################################################################	1154	#############################################################################
672		1155
…		…
681	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1164	ways, the "simple" way, using only C<on_read> and the "complex" way, using
682	a queue.	1165	a queue.
683		1166
684	In the simple case, you just install an C<on_read> callback and whenever	1167	In the simple case, you just install an C<on_read> callback and whenever
685	new data arrives, it will be called. You can then remove some data (if	1168	new data arrives, it will be called. You can then remove some data (if
686	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1169	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
687	leave the data there if you want to accumulate more (e.g. when only a	1170	leave the data there if you want to accumulate more (e.g. when only a
688	partial message has been received so far).	1171	partial message has been received so far), or change the read queue with
		1172	e.g. C<push_read>.
689		1173
690	In the more complex case, you want to queue multiple callbacks. In this	1174	In the more complex case, you want to queue multiple callbacks. In this
691	case, AnyEvent::Handle will call the first queued callback each time new	1175	case, AnyEvent::Handle will call the first queued callback each time new
692	data arrives (also the first time it is queued) and removes it when it has	1176	data arrives (also the first time it is queued) and remove it when it has
693	done its job (see C<push_read>, below).	1177	done its job (see C<push_read>, below).
694		1178
695	This way you can, for example, push three line-reads, followed by reading	1179	This way you can, for example, push three line-reads, followed by reading
696	a chunk of data, and AnyEvent::Handle will execute them in order.	1180	a chunk of data, and AnyEvent::Handle will execute them in order.
697		1181
…		…
754	=cut	1238	=cut
755		1239
756	sub _drain_rbuf {	1240	sub _drain_rbuf {
757	my ($self) = @_;	1241	my ($self) = @_;
758		1242
		1243	# avoid recursion
		1244	return if $self->{_skip_drain_rbuf};
759	local $self->{_in_drain} = 1;	1245	local $self->{_skip_drain_rbuf} = 1;
760
761	if (
762	defined $self->{rbuf_max}
763	&& $self->{rbuf_max} < length $self->{rbuf}
764	) {
765	$self->_error (&Errno::ENOSPC, 1), return;
766	}
767		1246
768	while () {	1247	while () {
		1248	# we need to use a separate tls read buffer, as we must not receive data while
		1249	# we are draining the buffer, and this can only happen with TLS.
		1250	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1251	if exists $self->{_tls_rbuf};
		1252
769	my $len = length $self->{rbuf};	1253	my $len = length $self->{rbuf};
770		1254
771	if (my $cb = shift @{ $self->{_queue} }) {	1255	if (my $cb = shift @{ $self->{_queue} }) {
772	unless ($cb->($self)) {	1256	unless ($cb->($self)) {
773	if ($self->{_eof}) {	1257	# no progress can be made
774	# no progress can be made (not enough data and no data forthcoming)	1258	# (not enough data and no data forthcoming)
775	$self->_error (&Errno::EPIPE, 1), return;	1259	$self->_error (Errno::EPIPE, 1), return
776	}	1260	if $self->{_eof};
777		1261
778	unshift @{ $self->{_queue} }, $cb;	1262	unshift @{ $self->{_queue} }, $cb;
779	last;	1263	last;
780	}	1264	}
781	} elsif ($self->{on_read}) {	1265	} elsif ($self->{on_read}) {
…		…
788	&& !@{ $self->{_queue} } # and the queue is still empty	1272	&& !@{ $self->{_queue} } # and the queue is still empty
789	&& $self->{on_read} # but we still have on_read	1273	&& $self->{on_read} # but we still have on_read
790	) {	1274	) {
791	# no further data will arrive	1275	# no further data will arrive
792	# so no progress can be made	1276	# so no progress can be made
793	$self->_error (&Errno::EPIPE, 1), return	1277	$self->_error (Errno::EPIPE, 1), return
794	if $self->{_eof};	1278	if $self->{_eof};
795		1279
796	last; # more data might arrive	1280	last; # more data might arrive
797	}	1281	}
798	} else {	1282	} else {
799	# read side becomes idle	1283	# read side becomes idle
800	delete $self->{_rw};	1284	delete $self->{_rw} unless $self->{tls};
801	last;	1285	last;
802	}	1286	}
803	}	1287	}
804		1288
805	if ($self->{_eof}) {	1289	if ($self->{_eof}) {
806	if ($self->{on_eof}) {	1290	$self->{on_eof}
807	$self->{on_eof}($self)	1291	? $self->{on_eof}($self)
808	} else {	1292	: $self->_error (0, 1, "Unexpected end-of-file");
809	$self->_error (0, 1);	1293
810	}	1294	return;
		1295	}
		1296
		1297	if (
		1298	defined $self->{rbuf_max}
		1299	&& $self->{rbuf_max} < length $self->{rbuf}
		1300	) {
		1301	$self->_error (Errno::ENOSPC, 1), return;
811	}	1302	}
812		1303
813	# may need to restart read watcher	1304	# may need to restart read watcher
814	unless ($self->{_rw}) {	1305	unless ($self->{_rw}) {
815	$self->start_read	1306	$self->start_read
…		…
821		1312
822	This replaces the currently set C<on_read> callback, or clears it (when	1313	This replaces the currently set C<on_read> callback, or clears it (when
823	the new callback is C<undef>). See the description of C<on_read> in the	1314	the new callback is C<undef>). See the description of C<on_read> in the
824	constructor.	1315	constructor.
825		1316
		1317	This method may invoke callbacks (and therefore the handle might be
		1318	destroyed after it returns).
		1319
826	=cut	1320	=cut
827		1321
828	sub on_read {	1322	sub on_read {
829	my ($self, $cb) = @_;	1323	my ($self, $cb) = @_;
830		1324
831	$self->{on_read} = $cb;	1325	$self->{on_read} = $cb;
832	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1326	$self->_drain_rbuf if $cb;
833	}	1327	}
834		1328
835	=item $handle->rbuf	1329	=item $handle->rbuf
836		1330
837	Returns the read buffer (as a modifiable lvalue).	1331	Returns the read buffer (as a modifiable lvalue). You can also access the
		1332	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1333	much faster, and no less clean).
838		1334
839	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1335	The only operation allowed on the read buffer (apart from looking at it)
840	you want.	1336	is removing data from its beginning. Otherwise modifying or appending to
		1337	it is not allowed and will lead to hard-to-track-down bugs.
841		1338
842	NOTE: The read buffer should only be used or modified if the C<on_read>,	1339	NOTE: The read buffer should only be used or modified in the C<on_read>
843	C<push_read> or C<unshift_read> methods are used. The other read methods	1340	callback or when C<push_read> or C<unshift_read> are used with a single
844	automatically manage the read buffer.	1341	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1342	will manage the read buffer on their own.
845		1343
846	=cut	1344	=cut
847		1345
848	sub rbuf : lvalue {	1346	sub rbuf : lvalue {
849	$_[0]{rbuf}	1347	$_[0]{rbuf}
…		…
866		1364
867	If enough data was available, then the callback must remove all data it is	1365	If enough data was available, then the callback must remove all data it is
868	interested in (which can be none at all) and return a true value. After returning	1366	interested in (which can be none at all) and return a true value. After returning
869	true, it will be removed from the queue.	1367	true, it will be removed from the queue.
870		1368
		1369	These methods may invoke callbacks (and therefore the handle might be
		1370	destroyed after it returns).
		1371
871	=cut	1372	=cut
872		1373
873	our %RH;	1374	our %RH;
874		1375
875	sub register_read_type($$) {	1376	sub register_read_type($$) {
…		…
881	my $cb = pop;	1382	my $cb = pop;
882		1383
883	if (@_) {	1384	if (@_) {
884	my $type = shift;	1385	my $type = shift;
885		1386
		1387	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
886	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1388	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
887	->($self, $cb, @_);	1389	->($self, $cb, @_);
888	}	1390	}
889		1391
890	push @{ $self->{_queue} }, $cb;	1392	push @{ $self->{_queue} }, $cb;
891	$self->_drain_rbuf unless $self->{_in_drain};	1393	$self->_drain_rbuf;
892	}	1394	}
893		1395
894	sub unshift_read {	1396	sub unshift_read {
895	my $self = shift;	1397	my $self = shift;
896	my $cb = pop;	1398	my $cb = pop;
897		1399
898	if (@_) {	1400	if (@_) {
899	my $type = shift;	1401	my $type = shift;
900		1402
		1403	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
901	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1404	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
902	->($self, $cb, @_);	1405	->($self, $cb, @_);
903	}	1406	}
904		1407
905
906	unshift @{ $self->{_queue} }, $cb;	1408	unshift @{ $self->{_queue} }, $cb;
907	$self->_drain_rbuf unless $self->{_in_drain};	1409	$self->_drain_rbuf;
908	}	1410	}
909		1411
910	=item $handle->push_read (type => @args, $cb)	1412	=item $handle->push_read (type => @args, $cb)
911		1413
912	=item $handle->unshift_read (type => @args, $cb)	1414	=item $handle->unshift_read (type => @args, $cb)
913		1415
914	Instead of providing a callback that parses the data itself you can chose	1416	Instead of providing a callback that parses the data itself you can chose
915	between a number of predefined parsing formats, for chunks of data, lines	1417	between a number of predefined parsing formats, for chunks of data, lines
916	etc.	1418	etc. You can also specify the (fully qualified) name of a package, in
		1419	which case AnyEvent tries to load the package and then expects to find the
		1420	C<anyevent_read_type> function inside (see "custom read types", below).
917		1421
918	Predefined types are (if you have ideas for additional types, feel free to	1422	Predefined types are (if you have ideas for additional types, feel free to
919	drop by and tell us):	1423	drop by and tell us):
920		1424
921	=over 4	1425	=over 4
…		…
1013	the receive buffer when neither C<$accept> nor C<$reject> match,	1517	the receive buffer when neither C<$accept> nor C<$reject> match,
1014	and everything preceding and including the match will be accepted	1518	and everything preceding and including the match will be accepted
1015	unconditionally. This is useful to skip large amounts of data that you	1519	unconditionally. This is useful to skip large amounts of data that you
1016	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1520	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1017	have to start matching from the beginning. This is purely an optimisation	1521	have to start matching from the beginning. This is purely an optimisation
1018	and is usually worth only when you expect more than a few kilobytes.	1522	and is usually worth it only when you expect more than a few kilobytes.
1019		1523
1020	Example: expect a http header, which ends at C<\015\012\015\012>. Since we	1524	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1021	expect the header to be very large (it isn't in practise, but...), we use	1525	expect the header to be very large (it isn't in practice, but...), we use
1022	a skip regex to skip initial portions. The skip regex is tricky in that	1526	a skip regex to skip initial portions. The skip regex is tricky in that
1023	it only accepts something not ending in either \015 or \012, as these are	1527	it only accepts something not ending in either \015 or \012, as these are
1024	required for the accept regex.	1528	required for the accept regex.
1025		1529
1026	$handle->push_read (regex =>	1530	$handle->push_read (regex =>
…		…
1039		1543
1040	sub {	1544	sub {
1041	# accept	1545	# accept
1042	if ($$rbuf =~ $accept) {	1546	if ($$rbuf =~ $accept) {
1043	$data .= substr $$rbuf, 0, $+[0], "";	1547	$data .= substr $$rbuf, 0, $+[0], "";
1044	$cb->($self, $data);	1548	$cb->($_[0], $data);
1045	return 1;	1549	return 1;
1046	}	1550	}
1047		1551
1048	# reject	1552	# reject
1049	if ($reject && $$rbuf =~ $reject) {	1553	if ($reject && $$rbuf =~ $reject) {
1050	$self->_error (&Errno::EBADMSG);	1554	$_[0]->_error (Errno::EBADMSG);
1051	}	1555	}
1052		1556
1053	# skip	1557	# skip
1054	if ($skip && $$rbuf =~ $skip) {	1558	if ($skip && $$rbuf =~ $skip) {
1055	$data .= substr $$rbuf, 0, $+[0], "";	1559	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1071	my ($self, $cb) = @_;	1575	my ($self, $cb) = @_;
1072		1576
1073	sub {	1577	sub {
1074	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1578	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1075	if ($_[0]{rbuf} =~ /[^0-9]/) {	1579	if ($_[0]{rbuf} =~ /[^0-9]/) {
1076	$self->_error (&Errno::EBADMSG);	1580	$_[0]->_error (Errno::EBADMSG);
1077	}	1581	}
1078	return;	1582	return;
1079	}	1583	}
1080		1584
1081	my $len = $1;	1585	my $len = $1;
1082		1586
1083	$self->unshift_read (chunk => $len, sub {	1587	$_[0]->unshift_read (chunk => $len, sub {
1084	my $string = $_[1];	1588	my $string = $_[1];
1085	$_[0]->unshift_read (chunk => 1, sub {	1589	$_[0]->unshift_read (chunk => 1, sub {
1086	if ($_[1] eq ",") {	1590	if ($_[1] eq ",") {
1087	$cb->($_[0], $string);	1591	$cb->($_[0], $string);
1088	} else {	1592	} else {
1089	$self->_error (&Errno::EBADMSG);	1593	$_[0]->_error (Errno::EBADMSG);
1090	}	1594	}
1091	});	1595	});
1092	});	1596	});
1093		1597
1094	1	1598	1
…		…
1100	An octet string prefixed with an encoded length. The encoding C<$format>	1604	An octet string prefixed with an encoded length. The encoding C<$format>
1101	uses the same format as a Perl C<pack> format, but must specify a single	1605	uses the same format as a Perl C<pack> format, but must specify a single
1102	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1606	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1103	optional C<!>, C<< < >> or C<< > >> modifier).	1607	optional C<!>, C<< < >> or C<< > >> modifier).
1104		1608
1105	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.	1609	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1610	EPP uses a prefix of C<N> (4 octtes).
1106		1611
1107	Example: read a block of data prefixed by its length in BER-encoded	1612	Example: read a block of data prefixed by its length in BER-encoded
1108	format (very efficient).	1613	format (very efficient).
1109		1614
1110	$handle->push_read (packstring => "w", sub {	1615	$handle->push_read (packstring => "w", sub {
…		…
1140	}	1645	}
1141	};	1646	};
1142		1647
1143	=item json => $cb->($handle, $hash_or_arrayref)	1648	=item json => $cb->($handle, $hash_or_arrayref)
1144		1649
1145	Reads a JSON object or array, decodes it and passes it to the callback.	1650	Reads a JSON object or array, decodes it and passes it to the
		1651	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1146		1652
1147	If a C<json> object was passed to the constructor, then that will be used	1653	If a C<json> object was passed to the constructor, then that will be used
1148	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1654	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1149		1655
1150	This read type uses the incremental parser available with JSON version	1656	This read type uses the incremental parser available with JSON version
…		…
1159	=cut	1665	=cut
1160		1666
1161	register_read_type json => sub {	1667	register_read_type json => sub {
1162	my ($self, $cb) = @_;	1668	my ($self, $cb) = @_;
1163		1669
1164	require JSON;	1670	my $json = $self->{json} ||= json_coder;
1165		1671
1166	my $data;	1672	my $data;
1167	my $rbuf = \$self->{rbuf};	1673	my $rbuf = \$self->{rbuf};
1168		1674
1169	my $json = $self->{json} ||= JSON->new->utf8;
1170
1171	sub {	1675	sub {
1172	my $ref = $json->incr_parse ($self->{rbuf});	1676	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1173		1677
1174	if ($ref) {	1678	if ($ref) {
1175	$self->{rbuf} = $json->incr_text;	1679	$_[0]{rbuf} = $json->incr_text;
1176	$json->incr_text = "";	1680	$json->incr_text = "";
1177	$cb->($self, $ref);	1681	$cb->($_[0], $ref);
1178		1682
1179	1	1683	1
		1684	} elsif ($@) {
		1685	# error case
		1686	$json->incr_skip;
		1687
		1688	$_[0]{rbuf} = $json->incr_text;
		1689	$json->incr_text = "";
		1690
		1691	$_[0]->_error (Errno::EBADMSG);
		1692
		1693	()
1180	} else {	1694	} else {
1181	$self->{rbuf} = "";	1695	$_[0]{rbuf} = "";
		1696
1182	()	1697	()
1183	}	1698	}
1184	}	1699	}
1185	};	1700	};
1186		1701
…		…
1218	# read remaining chunk	1733	# read remaining chunk
1219	$_[0]->unshift_read (chunk => $len, sub {	1734	$_[0]->unshift_read (chunk => $len, sub {
1220	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1735	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1221	$cb->($_[0], $ref);	1736	$cb->($_[0], $ref);
1222	} else {	1737	} else {
1223	$self->_error (&Errno::EBADMSG);	1738	$_[0]->_error (Errno::EBADMSG);
1224	}	1739	}
1225	});	1740	});
1226	}	1741	}
1227		1742
1228	1	1743	1
1229	}	1744	}
1230	};	1745	};
1231		1746
1232	=back	1747	=back
1233		1748
1234	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1749	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1235		1750
1236	This function (not method) lets you add your own types to C<push_read>.	1751	Instead of one of the predefined types, you can also specify the name
		1752	of a package. AnyEvent will try to load the package and then expects to
		1753	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1754	progressively tries to load the parent package until it either finds the
		1755	function (good) or runs out of packages (bad).
1237		1756
1238	Whenever the given C<type> is used, C<push_read> will invoke the code	1757	Whenever this type is used, C<push_read> will invoke the function with the
1239	reference with the handle object, the callback and the remaining	1758	handle object, the original callback and the remaining arguments.
1240	arguments.
1241		1759
1242	The code reference is supposed to return a callback (usually a closure)	1760	The function is supposed to return a callback (usually a closure) that
1243	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1761	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1762	mentally treat the function as a "configurable read type to read callback"
		1763	converter.
1244		1764
1245	It should invoke the passed callback when it is done reading (remember to	1765	It should invoke the original callback when it is done reading (remember
1246	pass C<$handle> as first argument as all other callbacks do that).	1766	to pass C<$handle> as first argument as all other callbacks do that,
		1767	although there is no strict requirement on this).
1247		1768
1248	Note that this is a function, and all types registered this way will be
1249	global, so try to use unique names.
1250
1251	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1769	For examples, see the source of this module (F<perldoc -m
1252	search for C<register_read_type>)).	1770	AnyEvent::Handle>, search for C<register_read_type>)).
1253		1771
1254	=item $handle->stop_read	1772	=item $handle->stop_read
1255		1773
1256	=item $handle->start_read	1774	=item $handle->start_read
1257		1775
…		…
1263	Note that AnyEvent::Handle will automatically C<start_read> for you when	1781	Note that AnyEvent::Handle will automatically C<start_read> for you when
1264	you change the C<on_read> callback or push/unshift a read callback, and it	1782	you change the C<on_read> callback or push/unshift a read callback, and it
1265	will automatically C<stop_read> for you when neither C<on_read> is set nor	1783	will automatically C<stop_read> for you when neither C<on_read> is set nor
1266	there are any read requests in the queue.	1784	there are any read requests in the queue.
1267		1785
		1786	In older versions of this module (<= 5.3), these methods had no effect,
		1787	as TLS does not support half-duplex connections. In current versions they
		1788	work as expected, as this behaviour is required to avoid certain resource
		1789	attacks, where the program would be forced to read (and buffer) arbitrary
		1790	amounts of data before being able to send some data. The drawback is that
		1791	some readings of the the SSL/TLS specifications basically require this
		1792	attack to be working, as SSL/TLS implementations might stall sending data
		1793	during a rehandshake.
		1794
		1795	As a guideline, during the initial handshake, you should not stop reading,
		1796	and as a client, it might cause problems, depending on your applciation.
		1797
1268	=cut	1798	=cut
1269		1799
1270	sub stop_read {	1800	sub stop_read {
1271	my ($self) = @_;	1801	my ($self) = @_;
1272		1802
…		…
1274	}	1804	}
1275		1805
1276	sub start_read {	1806	sub start_read {
1277	my ($self) = @_;	1807	my ($self) = @_;
1278		1808
1279	unless ($self->{_rw} || $self->{_eof}) {	1809	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1280	Scalar::Util::weaken $self;	1810	Scalar::Util::weaken $self;
1281		1811
1282	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1812	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1283	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1813	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1284	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1814	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1285		1815
1286	if ($len > 0) {	1816	if ($len > 0) {
1287	$self->{_activity} = AnyEvent->now;	1817	$self->{_activity} = $self->{_ractivity} = AE::now;
1288		1818
1289	$self->{filter_r}	1819	if ($self->{tls}) {
1290	? $self->{filter_r}($self, $rbuf)	1820	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1291	: $self->{_in_drain} || $self->_drain_rbuf;	1821
		1822	&_dotls ($self);
		1823	} else {
		1824	$self->_drain_rbuf;
		1825	}
		1826
		1827	if ($len == $self->{read_size}) {
		1828	$self->{read_size} *= 2;
		1829	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1830	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1831	}
1292		1832
1293	} elsif (defined $len) {	1833	} elsif (defined $len) {
1294	delete $self->{_rw};	1834	delete $self->{_rw};
1295	$self->{_eof} = 1;	1835	$self->{_eof} = 1;
1296	$self->_drain_rbuf unless $self->{_in_drain};	1836	$self->_drain_rbuf;
1297		1837
1298	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1838	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1299	return $self->_error ($!, 1);	1839	return $self->_error ($!, 1);
1300	}	1840	}
1301	});	1841	};
1302	}	1842	}
1303	}	1843	}
1304		1844
		1845	our $ERROR_SYSCALL;
		1846	our $ERROR_WANT_READ;
		1847
		1848	sub _tls_error {
		1849	my ($self, $err) = @_;
		1850
		1851	return $self->_error ($!, 1)
		1852	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1853
		1854	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1855
		1856	# reduce error string to look less scary
		1857	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1858
		1859	if ($self->{_on_starttls}) {
		1860	(delete $self->{_on_starttls})->($self, undef, $err);
		1861	&_freetls;
		1862	} else {
		1863	&_freetls;
		1864	$self->_error (Errno::EPROTO, 1, $err);
		1865	}
		1866	}
		1867
		1868	# poll the write BIO and send the data if applicable
		1869	# also decode read data if possible
		1870	# this is basiclaly our TLS state machine
		1871	# more efficient implementations are possible with openssl,
		1872	# but not with the buggy and incomplete Net::SSLeay.
1305	sub _dotls {	1873	sub _dotls {
1306	my ($self) = @_;	1874	my ($self) = @_;
1307		1875
1308	my $buf;	1876	my $tmp;
1309		1877
1310	if (length $self->{_tls_wbuf}) {	1878	if (length $self->{_tls_wbuf}) {
1311	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1879	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1312	substr $self->{_tls_wbuf}, 0, $len, "";	1880	substr $self->{_tls_wbuf}, 0, $tmp, "";
1313	}	1881	}
1314	}
1315		1882
		1883	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1884	return $self->_tls_error ($tmp)
		1885	if $tmp != $ERROR_WANT_READ
		1886	&& ($tmp != $ERROR_SYSCALL || $!);
		1887	}
		1888
		1889	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1890	unless (length $tmp) {
		1891	$self->{_on_starttls}
		1892	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1893	&_freetls;
		1894
		1895	if ($self->{on_stoptls}) {
		1896	$self->{on_stoptls}($self);
		1897	return;
		1898	} else {
		1899	# let's treat SSL-eof as we treat normal EOF
		1900	delete $self->{_rw};
		1901	$self->{_eof} = 1;
		1902	}
		1903	}
		1904
		1905	$self->{_tls_rbuf} .= $tmp;
		1906	$self->_drain_rbuf;
		1907	$self->{tls} or return; # tls session might have gone away in callback
		1908	}
		1909
		1910	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1911	return $self->_tls_error ($tmp)
		1912	if $tmp != $ERROR_WANT_READ
		1913	&& ($tmp != $ERROR_SYSCALL || $!);
		1914
1316	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1915	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1317	$self->{wbuf} .= $buf;	1916	$self->{wbuf} .= $tmp;
1318	$self->_drain_wbuf;	1917	$self->_drain_wbuf;
		1918	$self->{tls} or return; # tls session might have gone away in callback
1319	}	1919	}
1320		1920
1321	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1921	$self->{_on_starttls}
1322	if (length $buf) {	1922	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1323	$self->{rbuf} .= $buf;	1923	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1324	$self->_drain_rbuf unless $self->{_in_drain};
1325	} else {
1326	# let's treat SSL-eof as we treat normal EOF
1327	$self->{_eof} = 1;
1328	$self->_shutdown;
1329	return;
1330	}
1331	}
1332
1333	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1334
1335	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1336	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1337	return $self->_error ($!, 1);
1338	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1339	return $self->_error (&Errno::EIO, 1);
1340	}
1341
1342	# all others are fine for our purposes
1343	}
1344	}	1924	}
1345		1925
1346	=item $handle->starttls ($tls[, $tls_ctx])	1926	=item $handle->starttls ($tls[, $tls_ctx])
1347		1927
1348	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1928	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1349	object is created, you can also do that at a later time by calling	1929	object is created, you can also do that at a later time by calling
1350	C<starttls>.	1930	C<starttls>.
1351		1931
		1932	Starting TLS is currently an asynchronous operation - when you push some
		1933	write data and then call C<< ->starttls >> then TLS negotiation will start
		1934	immediately, after which the queued write data is then sent.
		1935
1352	The first argument is the same as the C<tls> constructor argument (either	1936	The first argument is the same as the C<tls> constructor argument (either
1353	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1937	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1354		1938
1355	The second argument is the optional C<Net::SSLeay::CTX> object that is	1939	The second argument is the optional C<AnyEvent::TLS> object that is used
1356	used when AnyEvent::Handle has to create its own TLS connection object.	1940	when AnyEvent::Handle has to create its own TLS connection object, or
		1941	a hash reference with C<< key => value >> pairs that will be used to
		1942	construct a new context.
1357		1943
1358	The TLS connection object will end up in C<< $handle->{tls} >> after this	1944	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1359	call and can be used or changed to your liking. Note that the handshake	1945	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1360	might have already started when this function returns.	1946	changed to your liking. Note that the handshake might have already started
		1947	when this function returns.
1361		1948
		1949	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1950	handshakes on the same stream. It is best to not attempt to use the
		1951	stream after stopping TLS.
		1952
		1953	This method may invoke callbacks (and therefore the handle might be
		1954	destroyed after it returns).
		1955
1362	=cut	1956	=cut
		1957
		1958	our %TLS_CACHE; #TODO not yet documented, should we?
1363		1959
1364	sub starttls {	1960	sub starttls {
1365	my ($self, $ssl, $ctx) = @_;	1961	my ($self, $tls, $ctx) = @_;
1366		1962
1367	$self->stoptls;	1963	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1964	if $self->{tls};
1368		1965
1369	if ($ssl eq "accept") {	1966	$self->{tls} = $tls;
1370	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1967	$self->{tls_ctx} = $ctx if @_ > 2;
1371	Net::SSLeay::set_accept_state ($ssl);	1968
1372	} elsif ($ssl eq "connect") {	1969	return unless $self->{fh};
1373	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1970
1374	Net::SSLeay::set_connect_state ($ssl);	1971	require Net::SSLeay;
		1972
		1973	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1974	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1975
		1976	$tls = delete $self->{tls};
		1977	$ctx = $self->{tls_ctx};
		1978
		1979	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1980
		1981	if ("HASH" eq ref $ctx) {
		1982	require AnyEvent::TLS;
		1983
		1984	if ($ctx->{cache}) {
		1985	my $key = $ctx+0;
		1986	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1987	} else {
		1988	$ctx = new AnyEvent::TLS %$ctx;
		1989	}
		1990	}
1375	}	1991
1376		1992	$self->{tls_ctx} = $ctx || TLS_CTX ();
1377	$self->{tls} = $ssl;	1993	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1378		1994
1379	# basically, this is deep magic (because SSL_read should have the same issues)	1995	# basically, this is deep magic (because SSL_read should have the same issues)
1380	# but the openssl maintainers basically said: "trust us, it just works".	1996	# but the openssl maintainers basically said: "trust us, it just works".
1381	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1997	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1382	# and mismaintained ssleay-module doesn't even offer them).	1998	# and mismaintained ssleay-module doesn't even offer them).
1383	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1999	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1384	#	2000	#
1385	# in short: this is a mess.	2001	# in short: this is a mess.
1386	#	2002	#
1387	# note that we do not try to kepe the length constant between writes as we are required to do.	2003	# note that we do not try to keep the length constant between writes as we are required to do.
1388	# we assume that most (but not all) of this insanity only applies to non-blocking cases,	2004	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
1389	# and we drive openssl fully in blocking mode here.	2005	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2006	# have identity issues in that area.
1390	Net::SSLeay::CTX_set_mode ($self->{tls},	2007	# Net::SSLeay::CTX_set_mode ($ssl,
1391	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2008	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1392	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2009	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2010	Net::SSLeay::CTX_set_mode ($tls, 1|2);
1393		2011
1394	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2012	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1395	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1396		2014
		2015	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2016	$self->{rbuf} = "";
		2017
1397	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2018	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1398		2019
1399	$self->{filter_w} = sub {	2020	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1400	$_[0]{_tls_wbuf} .= ${$_[1]};	2021	if $self->{on_starttls};
1401	&_dotls;	2022
1402	};	2023	&_dotls; # need to trigger the initial handshake
1403	$self->{filter_r} = sub {	2024	$self->start_read; # make sure we actually do read
1404	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1405	&_dotls;
1406	};
1407	}	2025	}
1408		2026
1409	=item $handle->stoptls	2027	=item $handle->stoptls
1410		2028
1411	Destroys the SSL connection, if any. Partial read or write data will be	2029	Shuts down the SSL connection - this makes a proper EOF handshake by
1412	lost.	2030	sending a close notify to the other side, but since OpenSSL doesn't
		2031	support non-blocking shut downs, it is not guaranteed that you can re-use
		2032	the stream afterwards.
		2033
		2034	This method may invoke callbacks (and therefore the handle might be
		2035	destroyed after it returns).
1413		2036
1414	=cut	2037	=cut
1415		2038
1416	sub stoptls {	2039	sub stoptls {
1417	my ($self) = @_;	2040	my ($self) = @_;
1418		2041
1419	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2042	if ($self->{tls} && $self->{fh}) {
		2043	Net::SSLeay::shutdown ($self->{tls});
1420		2044
1421	delete $self->{_rbio};	2045	&_dotls;
1422	delete $self->{_wbio};	2046
1423	delete $self->{_tls_wbuf};	2047	# # we don't give a shit. no, we do, but we can't. no...#d#
1424	delete $self->{filter_r};	2048	# # we, we... have to use openssl :/#d#
1425	delete $self->{filter_w};	2049	# &_freetls;#d#
		2050	}
1426	}	2051	}
		2052
		2053	sub _freetls {
		2054	my ($self) = @_;
		2055
		2056	return unless $self->{tls};
		2057
		2058	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2059	if $self->{tls} > 0;
		2060
		2061	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2062	}
		2063
		2064	=item $handle->resettls
		2065
		2066	This rarely-used method simply resets and TLS state on the handle, usually
		2067	causing data loss.
		2068
		2069	One case where it may be useful is when you want to skip over the data in
		2070	the stream but you are not interested in interpreting it, so data loss is
		2071	no concern.
		2072
		2073	=cut
		2074
		2075	*resettls = \&_freetls;
1427		2076
1428	sub DESTROY {	2077	sub DESTROY {
1429	my $self = shift;	2078	my ($self) = @_;
1430		2079
1431	$self->stoptls;	2080	&_freetls;
1432		2081
1433	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2082	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1434		2083
1435	if ($linger && length $self->{wbuf}) {	2084	if ($linger && length $self->{wbuf} && $self->{fh}) {
1436	my $fh = delete $self->{fh};	2085	my $fh = delete $self->{fh};
1437	my $wbuf = delete $self->{wbuf};	2086	my $wbuf = delete $self->{wbuf};
1438		2087
1439	my @linger;	2088	my @linger;
1440		2089
1441	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2090	push @linger, AE::io $fh, 1, sub {
1442	my $len = syswrite $fh, $wbuf, length $wbuf;	2091	my $len = syswrite $fh, $wbuf, length $wbuf;
1443		2092
1444	if ($len > 0) {	2093	if ($len > 0) {
1445	substr $wbuf, 0, $len, "";	2094	substr $wbuf, 0, $len, "";
1446	} else {	2095	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1447	@linger = (); # end	2096	@linger = (); # end
1448	}	2097	}
		2098	};
		2099	push @linger, AE::timer $linger, 0, sub {
		2100	@linger = ();
		2101	};
		2102	}
		2103	}
		2104
		2105	=item $handle->destroy
		2106
		2107	Shuts down the handle object as much as possible - this call ensures that
		2108	no further callbacks will be invoked and as many resources as possible
		2109	will be freed. Any method you will call on the handle object after
		2110	destroying it in this way will be silently ignored (and it will return the
		2111	empty list).
		2112
		2113	Normally, you can just "forget" any references to an AnyEvent::Handle
		2114	object and it will simply shut down. This works in fatal error and EOF
		2115	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2116	callback, so when you want to destroy the AnyEvent::Handle object from
		2117	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2118	that case.
		2119
		2120	Destroying the handle object in this way has the advantage that callbacks
		2121	will be removed as well, so if those are the only reference holders (as
		2122	is common), then one doesn't need to do anything special to break any
		2123	reference cycles.
		2124
		2125	The handle might still linger in the background and write out remaining
		2126	data, as specified by the C<linger> option, however.
		2127
		2128	=cut
		2129
		2130	sub destroy {
		2131	my ($self) = @_;
		2132
		2133	$self->DESTROY;
		2134	%$self = ();
		2135	bless $self, "AnyEvent::Handle::destroyed";
		2136	}
		2137
		2138	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2139	#nop
		2140	}
		2141
		2142	=item $handle->destroyed
		2143
		2144	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2145	->destroy >>, true otherwise.
		2146
		2147	Can be useful to decide whether the handle is still valid after some
		2148	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2149	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2150	can destroy the handle, so work can be avoided by checking sometimes:
		2151
		2152	$hdl->starttls ("accept");
		2153	return if $hdl->destroyed;
		2154	$hdl->push_write (...
		2155
		2156	Note that the call to C<push_write> will silently be ignored if the handle
		2157	has been destroyed, so often you can just ignore the possibility of the
		2158	handle being destroyed.
		2159
		2160	=cut
		2161
		2162	sub destroyed { 0 }
		2163	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2164
		2165	=item AnyEvent::Handle::TLS_CTX
		2166
		2167	This function creates and returns the AnyEvent::TLS object used by default
		2168	for TLS mode.
		2169
		2170	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2171
		2172	=cut
		2173
		2174	our $TLS_CTX;
		2175
		2176	sub TLS_CTX() {
		2177	$TLS_CTX ||= do {
		2178	require AnyEvent::TLS;
		2179
		2180	new AnyEvent::TLS
		2181	}
		2182	}
		2183
		2184	=back
		2185
		2186
		2187	=head1 NONFREQUENTLY ASKED QUESTIONS
		2188
		2189	=over 4
		2190
		2191	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2192	still get further invocations!
		2193
		2194	That's because AnyEvent::Handle keeps a reference to itself when handling
		2195	read or write callbacks.
		2196
		2197	It is only safe to "forget" the reference inside EOF or error callbacks,
		2198	from within all other callbacks, you need to explicitly call the C<<
		2199	->destroy >> method.
		2200
		2201	=item Why is my C<on_eof> callback never called?
		2202
		2203	Probably because your C<on_error> callback is being called instead: When
		2204	you have outstanding requests in your read queue, then an EOF is
		2205	considered an error as you clearly expected some data.
		2206
		2207	To avoid this, make sure you have an empty read queue whenever your handle
		2208	is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
		2209	an C<on_read> handler that simply pushes the first read requests in the
		2210	queue.
		2211
		2212	See also the next question, which explains this in a bit more detail.
		2213
		2214	=item How can I serve requests in a loop?
		2215
		2216	Most protocols consist of some setup phase (authentication for example)
		2217	followed by a request handling phase, where the server waits for requests
		2218	and handles them, in a loop.
		2219
		2220	There are two important variants: The first (traditional, better) variant
		2221	handles requests until the server gets some QUIT command, causing it to
		2222	close the connection first (highly desirable for a busy TCP server). A
		2223	client dropping the connection is an error, which means this variant can
		2224	detect an unexpected detection close.
		2225
		2226	To handle this case, always make sure you have a on-empty read queue, by
		2227	pushing the "read request start" handler on it:
		2228
		2229	# we assume a request starts with a single line
		2230	my @start_request; @start_request = (line => sub {
		2231	my ($hdl, $line) = @_;
		2232
		2233	... handle request
		2234
		2235	# push next request read, possibly from a nested callback
		2236	$hdl->push_read (@start_request);
		2237	});
		2238
		2239	# auth done, now go into request handling loop
		2240	# now push the first @start_request
		2241	$hdl->push_read (@start_request);
		2242
		2243	By always having an outstanding C<push_read>, the handle always expects
		2244	some data and raises the C<EPIPE> error when the connction is dropped
		2245	unexpectedly.
		2246
		2247	The second variant is a protocol where the client can drop the connection
		2248	at any time. For TCP, this means that the server machine may run out of
		2249	sockets easier, and in general, it means you cnanot distinguish a protocl
		2250	failure/client crash from a normal connection close. Nevertheless, these
		2251	kinds of protocols are common (and sometimes even the best solution to the
		2252	problem).
		2253
		2254	Having an outstanding read request at all times is possible if you ignore
		2255	C<EPIPE> errors, but this doesn't help with when the client drops the
		2256	connection during a request, which would still be an error.
		2257
		2258	A better solution is to push the initial request read in an C<on_read>
		2259	callback. This avoids an error, as when the server doesn't expect data
		2260	(i.e. is idly waiting for the next request, an EOF will not raise an
		2261	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2262	and simpler:
		2263
		2264	# auth done, now go into request handling loop
		2265	$hdl->on_read (sub {
		2266	my ($hdl) = @_;
		2267
		2268	# called each time we receive data but the read queue is empty
		2269	# simply start read the request
		2270
		2271	$hdl->push_read (line => sub {
		2272	my ($hdl, $line) = @_;
		2273
		2274	... handle request
		2275
		2276	# do nothing special when the request has been handled, just
		2277	# let the request queue go empty.
1449	});	2278	});
1450	push @linger, AnyEvent->timer (after => $linger, cb => sub {
1451	@linger = ();
1452	});	2279	});
		2280
		2281	=item I get different callback invocations in TLS mode/Why can't I pause
		2282	reading?
		2283
		2284	Unlike, say, TCP, TLS connections do not consist of two independent
		2285	communication channels, one for each direction. Or put differently, the
		2286	read and write directions are not independent of each other: you cannot
		2287	write data unless you are also prepared to read, and vice versa.
		2288
		2289	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2290	callback invocations when you are not expecting any read data - the reason
		2291	is that AnyEvent::Handle always reads in TLS mode.
		2292
		2293	During the connection, you have to make sure that you always have a
		2294	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2295	connection (or when you no longer want to use it) you can call the
		2296	C<destroy> method.
		2297
		2298	=item How do I read data until the other side closes the connection?
		2299
		2300	If you just want to read your data into a perl scalar, the easiest way
		2301	to achieve this is by setting an C<on_read> callback that does nothing,
		2302	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2303	will be in C<$_[0]{rbuf}>:
		2304
		2305	$handle->on_read (sub { });
		2306	$handle->on_eof (undef);
		2307	$handle->on_error (sub {
		2308	my $data = delete $_[0]{rbuf};
		2309	});
		2310
		2311	Note that this example removes the C<rbuf> member from the handle object,
		2312	which is not normally allowed by the API. It is expressly permitted in
		2313	this case only, as the handle object needs to be destroyed afterwards.
		2314
		2315	The reason to use C<on_error> is that TCP connections, due to latencies
		2316	and packets loss, might get closed quite violently with an error, when in
		2317	fact all data has been received.
		2318
		2319	It is usually better to use acknowledgements when transferring data,
		2320	to make sure the other side hasn't just died and you got the data
		2321	intact. This is also one reason why so many internet protocols have an
		2322	explicit QUIT command.
		2323
		2324	=item I don't want to destroy the handle too early - how do I wait until
		2325	all data has been written?
		2326
		2327	After writing your last bits of data, set the C<on_drain> callback
		2328	and destroy the handle in there - with the default setting of
		2329	C<low_water_mark> this will be called precisely when all data has been
		2330	written to the socket:
		2331
		2332	$handle->push_write (...);
		2333	$handle->on_drain (sub {
		2334	warn "all data submitted to the kernel\n";
		2335	undef $handle;
		2336	});
		2337
		2338	If you just want to queue some data and then signal EOF to the other side,
		2339	consider using C<< ->push_shutdown >> instead.
		2340
		2341	=item I want to contact a TLS/SSL server, I don't care about security.
		2342
		2343	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2344	connect to it and then create the AnyEvent::Handle with the C<tls>
		2345	parameter:
		2346
		2347	tcp_connect $host, $port, sub {
		2348	my ($fh) = @_;
		2349
		2350	my $handle = new AnyEvent::Handle
		2351	fh => $fh,
		2352	tls => "connect",
		2353	on_error => sub { ... };
		2354
		2355	$handle->push_write (...);
1453	}	2356	};
1454	}
1455		2357
1456	=item AnyEvent::Handle::TLS_CTX	2358	=item I want to contact a TLS/SSL server, I do care about security.
1457		2359
1458	This function creates and returns the Net::SSLeay::CTX object used by	2360	Then you should additionally enable certificate verification, including
1459	default for TLS mode.	2361	peername verification, if the protocol you use supports it (see
		2362	L<AnyEvent::TLS>, C<verify_peername>).
1460		2363
1461	The context is created like this:	2364	E.g. for HTTPS:
1462		2365
1463	Net::SSLeay::load_error_strings;	2366	tcp_connect $host, $port, sub {
1464	Net::SSLeay::SSLeay_add_ssl_algorithms;	2367	my ($fh) = @_;
1465	Net::SSLeay::randomize;
1466		2368
1467	my $CTX = Net::SSLeay::CTX_new;	2369	my $handle = new AnyEvent::Handle
		2370	fh => $fh,
		2371	peername => $host,
		2372	tls => "connect",
		2373	tls_ctx => { verify => 1, verify_peername => "https" },
		2374	...
1468		2375
1469	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL	2376	Note that you must specify the hostname you connected to (or whatever
		2377	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2378	peername verification will be done.
1470		2379
1471	=cut	2380	The above will use the system-dependent default set of trusted CA
		2381	certificates. If you want to check against a specific CA, add the
		2382	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1472		2383
1473	our $TLS_CTX;	2384	tls_ctx => {
		2385	verify => 1,
		2386	verify_peername => "https",
		2387	ca_file => "my-ca-cert.pem",
		2388	},
1474		2389
1475	sub TLS_CTX() {	2390	=item I want to create a TLS/SSL server, how do I do that?
1476	$TLS_CTX || do {
1477	require Net::SSLeay;
1478		2391
1479	Net::SSLeay::load_error_strings ();	2392	Well, you first need to get a server certificate and key. You have
1480	Net::SSLeay::SSLeay_add_ssl_algorithms ();	2393	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1481	Net::SSLeay::randomize ();	2394	self-signed certificate (cheap. check the search engine of your choice,
		2395	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2396	nice program for that purpose).
1482		2397
1483	$TLS_CTX = Net::SSLeay::CTX_new ();	2398	Then create a file with your private key (in PEM format, see
		2399	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2400	file should then look like this:
1484		2401
1485	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());	2402	-----BEGIN RSA PRIVATE KEY-----
		2403	...header data
		2404	... lots of base64'y-stuff
		2405	-----END RSA PRIVATE KEY-----
1486		2406
1487	$TLS_CTX	2407	-----BEGIN CERTIFICATE-----
1488	}	2408	... lots of base64'y-stuff
1489	}	2409	-----END CERTIFICATE-----
		2410
		2411	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2412	specify this file as C<cert_file>:
		2413
		2414	tcp_server undef, $port, sub {
		2415	my ($fh) = @_;
		2416
		2417	my $handle = new AnyEvent::Handle
		2418	fh => $fh,
		2419	tls => "accept",
		2420	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2421	...
		2422
		2423	When you have intermediate CA certificates that your clients might not
		2424	know about, just append them to the C<cert_file>.
1490		2425
1491	=back	2426	=back
		2427
1492		2428
1493	=head1 SUBCLASSING AnyEvent::Handle	2429	=head1 SUBCLASSING AnyEvent::Handle
1494		2430
1495	In many cases, you might want to subclass AnyEvent::Handle.	2431	In many cases, you might want to subclass AnyEvent::Handle.
1496		2432
…		…
1513		2449
1514	=item * all members not documented here and not prefixed with an underscore	2450	=item * all members not documented here and not prefixed with an underscore
1515	are free to use in subclasses.	2451	are free to use in subclasses.
1516		2452
1517	Of course, new versions of AnyEvent::Handle may introduce more "public"	2453	Of course, new versions of AnyEvent::Handle may introduce more "public"
1518	member variables, but thats just life, at least it is documented.	2454	member variables, but that's just life. At least it is documented.
1519		2455
1520	=back	2456	=back
1521		2457
1522	=head1 AUTHOR	2458	=head1 AUTHOR
1523		2459

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