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Revision 1.218 by root, Thu Feb 24 12:04:20 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 = 4.234;
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	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	This module is a helper module to make it easier to do event-based I/O on	35	This is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
54	The L<AnyEvent::Intro> tutorial contains some well-documented	38	The L<AnyEvent::Intro> tutorial contains some well-documented
55	AnyEvent::Handle examples.	39	AnyEvent::Handle examples.
56		40
57	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
58	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
59	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
60		47
61	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
62	argument.	49	argument.
63		50
64	=head2 SIGPIPE is not handled by this module	51	=cut
65		52
66	SIGPIPE is not handled by this module, so one of the practical	53	package AnyEvent::Handle;
67	requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} =	54
68	'IGNORE'>). At least, this is highly recommend in a networked program: If	55	use Scalar::Util ();
69	you use AnyEvent::Handle in a filter program (like sort), exiting on	56	use List::Util ();
70	SIGPIPE is probably the right thing to do.	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 }
71		81
72	=head1 METHODS	82	=head1 METHODS
73		83
74	=over 4	84	=over 4
75		85
76	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
77		87
78	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
79		89
80	=over 4	90	=over 4
81		91
82	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
83		93
84	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
85
86	NOTE: The filehandle will be set to non-blocking mode (using	95	NOTE: The filehandle will be set to non-blocking mode (using
87	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
88	that mode.	97	that mode.
89		98
		99	=item connect => [$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
90	=item on_eof => $cb->($handle)	116	=item on_prepare => $cb->($handle)
91		117
92	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
93	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
94	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).
95		123
96	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
97	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
98	callback and continue writing data, as only the read part has been shut	126	default timeout is to be used).
99	down.
100		127
101	While not mandatory, it is I<highly> recommended to set an eof callback,	128	=item on_connect => $cb->($handle, $host, $port, $retry->())
102	otherwise you might end up with a closed socket while you are still
103	waiting for data.
104		129
105	If an EOF condition has been detected but no C<on_eof> callback has been	130	This callback is called when a connection has been successfully established.
106	set, then a fatal error will be raised with C<$!> set to <0>.
107		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
108	=item on_error => $cb->($handle, $fatal)	154	=item on_error => $cb->($handle, $fatal, $message)
109		155
110	This is the error callback, which is called when, well, some error	156	This is the error callback, which is called when, well, some error
111	occured, such as not being able to resolve the hostname, failure to	157	occured, such as not being able to resolve the hostname, failure to
112	connect or a read error.	158	connect, or a read error.
113		159
114	Some errors are fatal (which is indicated by C<$fatal> being true). On	160	Some errors are fatal (which is indicated by C<$fatal> being true). On
115	fatal errors the handle object will be shut down and will not be usable	161	fatal errors the handle object will be destroyed (by a call to C<< ->
116	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal	162	destroy >>) after invoking the error callback (which means you are free to
117	errors are an EOF condition with active (but unsatisifable) read watchers	163	examine the handle object). Examples of fatal errors are an EOF condition
118	(C<EPIPE>) or I/O errors.	164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
119		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
120	Non-fatal errors can be retried by simply returning, but it is recommended	173	Non-fatal errors can be retried by returning, but it is recommended
121	to simply ignore this parameter and instead abondon the handle object	174	to simply ignore this parameter and instead abondon the handle object
122	when this callback is invoked. Examples of non-fatal errors are timeouts	175	when this callback is invoked. Examples of non-fatal errors are timeouts
123	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).	176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
124		177
125	On callback entrance, the value of C<$!> contains the operating system	178	On entry to the callback, the value of C<$!> contains the operating
126	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>).
127		181
128	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
129	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
130	C<croak>.	184	C<croak>.
131		185
132	=item on_read => $cb->($handle)	186	=item on_read => $cb->($handle)
133		187
134	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
135	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
136	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
137	read buffer).	191	read buffer).
138		192
139	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 >>
140	method or access the C<$handle->{rbuf}> member directly.	194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
141		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
142	When an EOF condition is detected then AnyEvent::Handle will first try to	201	When an EOF condition is detected, AnyEvent::Handle will first try to
143	feed all the remaining data to the queued callbacks and C<on_read> before	202	feed all the remaining data to the queued callbacks and C<on_read> before
144	calling the C<on_eof> callback. If no progress can be made, then a fatal	203	calling the C<on_eof> callback. If no progress can be made, then a fatal
145	error will be raised (with C<$!> set to C<EPIPE>).	204	error will be raised (with C<$!> set to C<EPIPE>).
146		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
147	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
148		228
149	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
150	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
151		231
152	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.
153		233
154	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
155	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
…		…
157	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
158	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
159		239
160	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
161		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
162	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
163	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
164	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
165	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).
166		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
167	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
168	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
169	idle then you should disable the timout temporarily or ignore the timeout	261	idle then you should disable the timeout temporarily or ignore the
170	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
171	restart the timeout.	263	AnyEvent::Handle will simply restart the timeout.
172		264
173	Zero (the default) disables this timeout.	265	Zero (the default) disables the corresponding timeout.
174		266
175	=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)
176		272
177	Called whenever the inactivity timeout passes. If you return from this	273	Called whenever the inactivity timeout passes. If you return from this
178	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,
179	so this condition is not fatal in any way.	275	so this condition is not fatal in any way.
180		276
…		…
188	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
189	(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
190	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
191	isn't finished).	287	isn't finished).
192		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
193	=item autocork => <boolean>	304	=item autocork => <boolean>
194		305
195	When disabled (the default), then C<push_write> will try to immediately	306	When disabled (the default), C<push_write> will try to immediately
196	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
197	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
198	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
199	disadvantage is usually avoided by your kernel's nagle algorithm, see	310	disadvantage is usually avoided by your kernel's nagle algorithm, see
200	C<no_delay>, but this option can save costly syscalls).	311	C<no_delay>, but this option can save costly syscalls).
201		312
202	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
203	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,
204	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
205	the write buffer often is full). It also increases write latency.	316	the write buffer often is full). It also increases write latency.
206		317
207	=item no_delay => <boolean>	318	=item no_delay => <boolean>
…		…
211	the Nagle algorithm, and usually it is beneficial.	322	the Nagle algorithm, and usually it is beneficial.
212		323
213	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
214	accomplishd by setting this option to a true value.	325	accomplishd by setting this option to a true value.
215		326
216	The default is your opertaing system's default behaviour (most likely	327	The default is your operating system's default behaviour (most likely
217	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.
218		361
219	=item read_size => <bytes>	362	=item read_size => <bytes>
220		363
221	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
222	try to read during each loop iteration, which affects memory	365	read during each loop iteration. Each handle object will consume at least
223	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.
224		375
225	=item low_water_mark => <bytes>	376	=item low_water_mark => <bytes>
226		377
227	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
228	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
229	considered empty.	380	considered empty.
230		381
231	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
232	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
233	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
234	is good in almost all cases.	385	is good in almost all cases.
235		386
236	=item linger => <seconds>	387	=item linger => <seconds>
237		388
238	If non-zero (default: C<3600>), then the destructor of the	389	If this is non-zero (default: C<3600>), the destructor of the
239	AnyEvent::Handle object will check whether there is still outstanding	390	AnyEvent::Handle object will check whether there is still outstanding
240	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
241	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
242	system treats outstanding data at socket close time).	393	system treats outstanding data at socket close time).
243		394
244	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
245	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>.
246		408
247	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	409	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
248		410
249	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
250	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
251	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.
252		417
253	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
254	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
255	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
256	to add the dependency yourself.	421	to add the dependency yourself.
…		…
260	mode.	425	mode.
261		426
262	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
263	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>
264	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
265	AnyEvent::Handle.	430	AnyEvent::Handle. Also, this module will take ownership of this connection
		431	object.
266		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
267	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.
268		443
269	=item tls_ctx => $ssl_ctx	444	=item tls_ctx => $anyevent_tls
270		445
271	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
272	(unless a connection object was specified directly). If this parameter is	447	(unless a connection object was specified directly). If this
273	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.
274		486
275	=item json => JSON or JSON::XS object	487	=item json => JSON or JSON::XS object
276		488
277	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.
278		490
…		…
281	texts.	493	texts.
282		494
283	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
284	use this functionality, as AnyEvent does not have a dependency itself.	496	use this functionality, as AnyEvent does not have a dependency itself.
285		497
286	=item filter_r => $cb
287
288	=item filter_w => $cb
289
290	These exist, but are undocumented at this time. (They are used internally
291	by the TLS code).
292
293	=back	498	=back
294		499
295	=cut	500	=cut
296		501
297	sub new {	502	sub new {
298	my $class = shift;	503	my $class = shift;
299
300	my $self = bless { @_ }, $class;	504	my $self = bless { @_ }, $class;
301		505
302	$self->{fh} or Carp::croak "mandatory argument fh is missing";	506	if ($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;
303		577
304	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	578	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
305		579
306	if ($self->{tls}) {	580	$self->{_activity} =
307	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
308	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	597	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
309	}	598	if $self->{tls};
310		599
311	$self->{_activity} = AnyEvent->now;
312	$self->_timeout;
313
314	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	600	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
315	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
316		601
317	$self->start_read	602	$self->start_read
318	if $self->{on_read};	603	if $self->{on_read} || @{ $self->{_queue} };
319		604
320	$self	605	$self->_drain_wbuf;
321	}
322
323	sub _shutdown {
324	my ($self) = @_;
325
326	delete $self->{_tw};
327	delete $self->{_rw};
328	delete $self->{_ww};
329	delete $self->{fh};
330
331	$self->stoptls;
332
333	delete $self->{on_read};
334	delete $self->{_queue};
335	}	606	}
336		607
337	sub _error {	608	sub _error {
338	my ($self, $errno, $fatal) = @_;	609	my ($self, $errno, $fatal, $message) = @_;
339
340	$self->_shutdown
341	if $fatal;
342		610
343	$! = $errno;	611	$! = $errno;
		612	$message ||= "$!";
344		613
345	if ($self->{on_error}) {	614	if ($self->{on_error}) {
346	$self->{on_error}($self, $fatal);	615	$self->{on_error}($self, $fatal, $message);
347	} else {	616	$self->destroy if $fatal;
		617	} elsif ($self->{fh} || $self->{connect}) {
		618	$self->destroy;
348	Carp::croak "AnyEvent::Handle uncaught error: $!";	619	Carp::croak "AnyEvent::Handle uncaught error: $message";
349	}	620	}
350	}	621	}
351		622
352	=item $fh = $handle->fh	623	=item $fh = $handle->fh
353		624
…		…
377	$_[0]{on_eof} = $_[1];	648	$_[0]{on_eof} = $_[1];
378	}	649	}
379		650
380	=item $handle->on_timeout ($cb)	651	=item $handle->on_timeout ($cb)
381		652
382	Replace the current C<on_timeout> callback, or disables the callback (but	653	=item $handle->on_rtimeout ($cb)
383	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
384	argument and method.
385		654
386	=cut	655	=item $handle->on_wtimeout ($cb)
387		656
388	sub on_timeout {	657	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
389	$_[0]{on_timeout} = $_[1];	658	callback, or disables the callback (but not the timeout) if C<$cb> =
390	}	659	C<undef>. See the C<timeout> constructor argument and method.
		660
		661	=cut
		662
		663	# see below
391		664
392	=item $handle->autocork ($boolean)	665	=item $handle->autocork ($boolean)
393		666
394	Enables or disables the current autocork behaviour (see C<autocork>	667	Enables or disables the current autocork behaviour (see C<autocork>
395	constructor argument).	668	constructor argument). Changes will only take effect on the next write.
396		669
397	=cut	670	=cut
		671
		672	sub autocork {
		673	$_[0]{autocork} = $_[1];
		674	}
398		675
399	=item $handle->no_delay ($boolean)	676	=item $handle->no_delay ($boolean)
400		677
401	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
402	the same name for details).	679	the same name for details).
…		…
404	=cut	681	=cut
405		682
406	sub no_delay {	683	sub no_delay {
407	$_[0]{no_delay} = $_[1];	684	$_[0]{no_delay} = $_[1];
408		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
409	eval {	700	eval {
410	local $SIG{__DIE__};	701	local $SIG{__DIE__};
411	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};
412	};	704	};
413	}	705	}
414		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
415	#############################################################################	779	#############################################################################
416		780
417	=item $handle->timeout ($seconds)	781	=item $handle->timeout ($seconds)
418		782
		783	=item $handle->rtimeout ($seconds)
		784
		785	=item $handle->wtimeout ($seconds)
		786
419	Configures (or disables) the inactivity timeout.	787	Configures (or disables) the inactivity timeout.
420		788
421	=cut	789	The timeout will be checked instantly, so this method might destroy the
		790	handle before it returns.
422		791
423	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 {
424	my ($self, $timeout) = @_;	816	my ($self, $new_value) = @_;
425		817
		818	$new_value >= 0
		819	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		820
426	$self->{timeout} = $timeout;	821	$self->{$timeout} = $new_value;
427	$self->_timeout;	822	delete $self->{$tw}; &$cb;
428	}	823	};
429		824
		825	*{"${dir}timeout_reset"} = sub {
		826	$_[0]{$activity} = AE::now;
		827	};
		828
		829	# main workhorse:
430	# reset the timeout watcher, as neccessary	830	# reset the timeout watcher, as neccessary
431	# also check for time-outs	831	# also check for time-outs
432	sub _timeout {	832	$cb = sub {
433	my ($self) = @_;	833	my ($self) = @_;
434		834
435	if ($self->{timeout}) {	835	if ($self->{$timeout} && $self->{fh}) {
436	my $NOW = AnyEvent->now;	836	my $NOW = AE::now;
437		837
438	# when would the timeout trigger?	838	# when would the timeout trigger?
439	my $after = $self->{_activity} + $self->{timeout} - $NOW;	839	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
440		840
441	# now or in the past already?	841	# now or in the past already?
442	if ($after <= 0) {	842	if ($after <= 0) {
443	$self->{_activity} = $NOW;	843	$self->{$activity} = $NOW;
444		844
445	if ($self->{on_timeout}) {	845	if ($self->{$on_timeout}) {
446	$self->{on_timeout}($self);	846	$self->{$on_timeout}($self);
447	} else {	847	} else {
448	$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};
449	}	856	}
450		857
451	# callback could have changed timeout value, optimise	858	Scalar::Util::weaken $self;
452	return unless $self->{timeout};	859	return unless $self; # ->error could have destroyed $self
453		860
454	# calculate new after	861	$self->{$tw} ||= AE::timer $after, 0, sub {
455	$after = $self->{timeout};	862	delete $self->{$tw};
		863	$cb->($self);
		864	};
		865	} else {
		866	delete $self->{$tw};
456	}	867	}
457
458	Scalar::Util::weaken $self;
459	return unless $self; # ->error could have destroyed $self
460
461	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
462	delete $self->{_tw};
463	$self->_timeout;
464	});
465	} else {
466	delete $self->{_tw};
467	}	868	}
468	}	869	}
469		870
470	#############################################################################	871	#############################################################################
471		872
…		…
487	=item $handle->on_drain ($cb)	888	=item $handle->on_drain ($cb)
488		889
489	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
490	C<on_drain> in the constructor).	891	C<on_drain> in the constructor).
491		892
		893	This method may invoke callbacks (and therefore the handle might be
		894	destroyed after it returns).
		895
492	=cut	896	=cut
493		897
494	sub on_drain {	898	sub on_drain {
495	my ($self, $cb) = @_;	899	my ($self, $cb) = @_;
496		900
497	$self->{on_drain} = $cb;	901	$self->{on_drain} = $cb;
498		902
499	$cb->($self)	903	$cb->($self)
500	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	904	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
501	}	905	}
502		906
503	=item $handle->push_write ($data)	907	=item $handle->push_write ($data)
504		908
505	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
506	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
507	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).
508		915
509	=cut	916	=cut
510		917
511	sub _drain_wbuf {	918	sub _drain_wbuf {
512	my ($self) = @_;	919	my ($self) = @_;
…		…
516	Scalar::Util::weaken $self;	923	Scalar::Util::weaken $self;
517		924
518	my $cb = sub {	925	my $cb = sub {
519	my $len = syswrite $self->{fh}, $self->{wbuf};	926	my $len = syswrite $self->{fh}, $self->{wbuf};
520		927
521	if ($len >= 0) {	928	if (defined $len) {
522	substr $self->{wbuf}, 0, $len, "";	929	substr $self->{wbuf}, 0, $len, "";
523		930
524	$self->{_activity} = AnyEvent->now;	931	$self->{_activity} = $self->{_wactivity} = AE::now;
525		932
526	$self->{on_drain}($self)	933	$self->{on_drain}($self)
527	if $self->{low_water_mark} >= length $self->{wbuf}	934	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
528	&& $self->{on_drain};	935	&& $self->{on_drain};
529		936
530	delete $self->{_ww} unless length $self->{wbuf};	937	delete $self->{_ww} unless length $self->{wbuf};
531	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	938	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
532	$self->_error ($!, 1);	939	$self->_error ($!, 1);
…		…
535		942
536	# try to write data immediately	943	# try to write data immediately
537	$cb->() unless $self->{autocork};	944	$cb->() unless $self->{autocork};
538		945
539	# if still data left in wbuf, we need to poll	946	# if still data left in wbuf, we need to poll
540	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	947	$self->{_ww} = AE::io $self->{fh}, 1, $cb
541	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	}
542	};	956	};
543	}	957	}
544		958
545	our %WH;	959	our %WH;
546		960
		961	# deprecated
547	sub register_write_type($$) {	962	sub register_write_type($$) {
548	$WH{$_[0]} = $_[1];	963	$WH{$_[0]} = $_[1];
549	}	964	}
550		965
551	sub push_write {	966	sub push_write {
552	my $self = shift;	967	my $self = shift;
553		968
554	if (@_ > 1) {	969	if (@_ > 1) {
555	my $type = shift;	970	my $type = shift;
556		971
		972	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
557	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	973	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
558	->($self, @_);	974	->($self, @_);
559	}	975	}
560		976
		977	# we downgrade here to avoid hard-to-track-down bugs,
		978	# and diagnose the problem earlier and better.
		979
561	if ($self->{filter_w}) {	980	if ($self->{tls}) {
562	$self->{filter_w}($self, \$_[0]);	981	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		982	&_dotls ($self) if $self->{fh};
563	} else {	983	} else {
564	$self->{wbuf} .= $_[0];	984	utf8::downgrade $self->{wbuf} .= $_[0];
565	$self->_drain_wbuf;	985	$self->_drain_wbuf if $self->{fh};
566	}	986	}
567	}	987	}
568		988
569	=item $handle->push_write (type => @args)	989	=item $handle->push_write (type => @args)
570		990
571	Instead of formatting your data yourself, you can also let this module do	991	Instead of formatting your data yourself, you can also let this module
572	the job by specifying a type and type-specific arguments.	992	do the job by specifying a type and type-specific arguments. You
		993	can also specify the (fully qualified) name of a package, in which
		994	case AnyEvent tries to load the package and then expects to find the
		995	C<anyevent_write_type> function inside (see "custom write types", below).
573		996
574	Predefined types are (if you have ideas for additional types, feel free to	997	Predefined types are (if you have ideas for additional types, feel free to
575	drop by and tell us):	998	drop by and tell us):
576		999
577	=over 4	1000	=over 4
…		…
584	=cut	1007	=cut
585		1008
586	register_write_type netstring => sub {	1009	register_write_type netstring => sub {
587	my ($self, $string) = @_;	1010	my ($self, $string) = @_;
588		1011
589	sprintf "%d:%s,", (length $string), $string	1012	(length $string) . ":$string,"
590	};	1013	};
591		1014
592	=item packstring => $format, $data	1015	=item packstring => $format, $data
593		1016
594	An octet string prefixed with an encoded length. The encoding C<$format>	1017	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
634	Other languages could read single lines terminated by a newline and pass	1057	Other languages could read single lines terminated by a newline and pass
635	this line into their JSON decoder of choice.	1058	this line into their JSON decoder of choice.
636		1059
637	=cut	1060	=cut
638		1061
		1062	sub json_coder() {
		1063	eval { require JSON::XS; JSON::XS->new->utf8 }
		1064	|| do { require JSON; JSON->new->utf8 }
		1065	}
		1066
639	register_write_type json => sub {	1067	register_write_type json => sub {
640	my ($self, $ref) = @_;	1068	my ($self, $ref) = @_;
641		1069
642	require JSON;	1070	my $json = $self->{json} ||= json_coder;
643		1071
644	$self->{json} ? $self->{json}->encode ($ref)	1072	$json->encode ($ref)
645	: JSON::encode_json ($ref)
646	};	1073	};
647		1074
648	=item storable => $reference	1075	=item storable => $reference
649		1076
650	Freezes the given reference using L<Storable> and writes it to the	1077	Freezes the given reference using L<Storable> and writes it to the
…		…
660	pack "w/a*", Storable::nfreeze ($ref)	1087	pack "w/a*", Storable::nfreeze ($ref)
661	};	1088	};
662		1089
663	=back	1090	=back
664		1091
665	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1092	=item $handle->push_shutdown
666		1093
667	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
668	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
669	reference with the handle object and the remaining arguments.	1129	the handle object and the remaining arguments.
670		1130
671	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
672	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.
673		1134
674	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
675	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	}
676		1151
677	=cut	1152	=cut
678		1153
679	#############################################################################	1154	#############################################################################
680		1155
…		…
689	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
690	a queue.	1165	a queue.
691		1166
692	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
693	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
694	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1169	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
695	leave the data there if you want to accumulate more (e.g. when only a	1170	leave the data there if you want to accumulate more (e.g. when only a
696	partial message has been received so far).	1171	partial message has been received so far), or change the read queue with
		1172	e.g. C<push_read>.
697		1173
698	In the more complex case, you want to queue multiple callbacks. In this	1174	In the more complex case, you want to queue multiple callbacks. In this
699	case, AnyEvent::Handle will call the first queued callback each time new	1175	case, AnyEvent::Handle will call the first queued callback each time new
700	data arrives (also the first time it is queued) and removes it when it has	1176	data arrives (also the first time it is queued) and remove it when it has
701	done its job (see C<push_read>, below).	1177	done its job (see C<push_read>, below).
702		1178
703	This way you can, for example, push three line-reads, followed by reading	1179	This way you can, for example, push three line-reads, followed by reading
704	a chunk of data, and AnyEvent::Handle will execute them in order.	1180	a chunk of data, and AnyEvent::Handle will execute them in order.
705		1181
…		…
762	=cut	1238	=cut
763		1239
764	sub _drain_rbuf {	1240	sub _drain_rbuf {
765	my ($self) = @_;	1241	my ($self) = @_;
766		1242
		1243	# avoid recursion
		1244	return if $self->{_skip_drain_rbuf};
767	local $self->{_in_drain} = 1;	1245	local $self->{_skip_drain_rbuf} = 1;
768
769	if (
770	defined $self->{rbuf_max}
771	&& $self->{rbuf_max} < length $self->{rbuf}
772	) {
773	$self->_error (&Errno::ENOSPC, 1), return;
774	}
775		1246
776	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
777	my $len = length $self->{rbuf};	1253	my $len = length $self->{rbuf};
778		1254
779	if (my $cb = shift @{ $self->{_queue} }) {	1255	if (my $cb = shift @{ $self->{_queue} }) {
780	unless ($cb->($self)) {	1256	unless ($cb->($self)) {
781	if ($self->{_eof}) {	1257	# no progress can be made
782	# no progress can be made (not enough data and no data forthcoming)	1258	# (not enough data and no data forthcoming)
783	$self->_error (&Errno::EPIPE, 1), return;	1259	$self->_error (Errno::EPIPE, 1), return
784	}	1260	if $self->{_eof};
785		1261
786	unshift @{ $self->{_queue} }, $cb;	1262	unshift @{ $self->{_queue} }, $cb;
787	last;	1263	last;
788	}	1264	}
789	} elsif ($self->{on_read}) {	1265	} elsif ($self->{on_read}) {
…		…
796	&& !@{ $self->{_queue} } # and the queue is still empty	1272	&& !@{ $self->{_queue} } # and the queue is still empty
797	&& $self->{on_read} # but we still have on_read	1273	&& $self->{on_read} # but we still have on_read
798	) {	1274	) {
799	# no further data will arrive	1275	# no further data will arrive
800	# so no progress can be made	1276	# so no progress can be made
801	$self->_error (&Errno::EPIPE, 1), return	1277	$self->_error (Errno::EPIPE, 1), return
802	if $self->{_eof};	1278	if $self->{_eof};
803		1279
804	last; # more data might arrive	1280	last; # more data might arrive
805	}	1281	}
806	} else {	1282	} else {
807	# read side becomes idle	1283	# read side becomes idle
808	delete $self->{_rw};	1284	delete $self->{_rw} unless $self->{tls};
809	last;	1285	last;
810	}	1286	}
811	}	1287	}
812		1288
813	if ($self->{_eof}) {	1289	if ($self->{_eof}) {
814	if ($self->{on_eof}) {	1290	$self->{on_eof}
815	$self->{on_eof}($self)	1291	? $self->{on_eof}($self)
816	} else {	1292	: $self->_error (0, 1, "Unexpected end-of-file");
817	$self->_error (0, 1);	1293
818	}	1294	return;
		1295	}
		1296
		1297	if (
		1298	defined $self->{rbuf_max}
		1299	&& $self->{rbuf_max} < length $self->{rbuf}
		1300	) {
		1301	$self->_error (Errno::ENOSPC, 1), return;
819	}	1302	}
820		1303
821	# may need to restart read watcher	1304	# may need to restart read watcher
822	unless ($self->{_rw}) {	1305	unless ($self->{_rw}) {
823	$self->start_read	1306	$self->start_read
…		…
829		1312
830	This replaces the currently set C<on_read> callback, or clears it (when	1313	This replaces the currently set C<on_read> callback, or clears it (when
831	the new callback is C<undef>). See the description of C<on_read> in the	1314	the new callback is C<undef>). See the description of C<on_read> in the
832	constructor.	1315	constructor.
833		1316
		1317	This method may invoke callbacks (and therefore the handle might be
		1318	destroyed after it returns).
		1319
834	=cut	1320	=cut
835		1321
836	sub on_read {	1322	sub on_read {
837	my ($self, $cb) = @_;	1323	my ($self, $cb) = @_;
838		1324
839	$self->{on_read} = $cb;	1325	$self->{on_read} = $cb;
840	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1326	$self->_drain_rbuf if $cb;
841	}	1327	}
842		1328
843	=item $handle->rbuf	1329	=item $handle->rbuf
844		1330
845	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).
846		1334
847	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)
848	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.
849		1338
850	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>
851	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
852	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.
853		1343
854	=cut	1344	=cut
855		1345
856	sub rbuf : lvalue {	1346	sub rbuf : lvalue {
857	$_[0]{rbuf}	1347	$_[0]{rbuf}
…		…
874		1364
875	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
876	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
877	true, it will be removed from the queue.	1367	true, it will be removed from the queue.
878		1368
		1369	These methods may invoke callbacks (and therefore the handle might be
		1370	destroyed after it returns).
		1371
879	=cut	1372	=cut
880		1373
881	our %RH;	1374	our %RH;
882		1375
883	sub register_read_type($$) {	1376	sub register_read_type($$) {
…		…
889	my $cb = pop;	1382	my $cb = pop;
890		1383
891	if (@_) {	1384	if (@_) {
892	my $type = shift;	1385	my $type = shift;
893		1386
		1387	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
894	$cb = ($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")
895	->($self, $cb, @_);	1389	->($self, $cb, @_);
896	}	1390	}
897		1391
898	push @{ $self->{_queue} }, $cb;	1392	push @{ $self->{_queue} }, $cb;
899	$self->_drain_rbuf unless $self->{_in_drain};	1393	$self->_drain_rbuf;
900	}	1394	}
901		1395
902	sub unshift_read {	1396	sub unshift_read {
903	my $self = shift;	1397	my $self = shift;
904	my $cb = pop;	1398	my $cb = pop;
905		1399
906	if (@_) {	1400	if (@_) {
907	my $type = shift;	1401	my $type = shift;
908		1402
		1403	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
909	$cb = ($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")
910	->($self, $cb, @_);	1405	->($self, $cb, @_);
911	}	1406	}
912		1407
913
914	unshift @{ $self->{_queue} }, $cb;	1408	unshift @{ $self->{_queue} }, $cb;
915	$self->_drain_rbuf unless $self->{_in_drain};	1409	$self->_drain_rbuf;
916	}	1410	}
917		1411
918	=item $handle->push_read (type => @args, $cb)	1412	=item $handle->push_read (type => @args, $cb)
919		1413
920	=item $handle->unshift_read (type => @args, $cb)	1414	=item $handle->unshift_read (type => @args, $cb)
921		1415
922	Instead of providing a callback that parses the data itself you can chose	1416	Instead of providing a callback that parses the data itself you can chose
923	between a number of predefined parsing formats, for chunks of data, lines	1417	between a number of predefined parsing formats, for chunks of data, lines
924	etc.	1418	etc. You can also specify the (fully qualified) name of a package, in
		1419	which case AnyEvent tries to load the package and then expects to find the
		1420	C<anyevent_read_type> function inside (see "custom read types", below).
925		1421
926	Predefined types are (if you have ideas for additional types, feel free to	1422	Predefined types are (if you have ideas for additional types, feel free to
927	drop by and tell us):	1423	drop by and tell us):
928		1424
929	=over 4	1425	=over 4
…		…
1021	the receive buffer when neither C<$accept> nor C<$reject> match,	1517	the receive buffer when neither C<$accept> nor C<$reject> match,
1022	and everything preceding and including the match will be accepted	1518	and everything preceding and including the match will be accepted
1023	unconditionally. This is useful to skip large amounts of data that you	1519	unconditionally. This is useful to skip large amounts of data that you
1024	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1520	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1025	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
1026	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.
1027		1523
1028	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
1029	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
1030	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
1031	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
1032	required for the accept regex.	1528	required for the accept regex.
1033		1529
1034	$handle->push_read (regex =>	1530	$handle->push_read (regex =>
…		…
1053	return 1;	1549	return 1;
1054	}	1550	}
1055		1551
1056	# reject	1552	# reject
1057	if ($reject && $$rbuf =~ $reject) {	1553	if ($reject && $$rbuf =~ $reject) {
1058	$self->_error (&Errno::EBADMSG);	1554	$self->_error (Errno::EBADMSG);
1059	}	1555	}
1060		1556
1061	# skip	1557	# skip
1062	if ($skip && $$rbuf =~ $skip) {	1558	if ($skip && $$rbuf =~ $skip) {
1063	$data .= substr $$rbuf, 0, $+[0], "";	1559	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1079	my ($self, $cb) = @_;	1575	my ($self, $cb) = @_;
1080		1576
1081	sub {	1577	sub {
1082	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1578	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1083	if ($_[0]{rbuf} =~ /[^0-9]/) {	1579	if ($_[0]{rbuf} =~ /[^0-9]/) {
1084	$self->_error (&Errno::EBADMSG);	1580	$self->_error (Errno::EBADMSG);
1085	}	1581	}
1086	return;	1582	return;
1087	}	1583	}
1088		1584
1089	my $len = $1;	1585	my $len = $1;
…		…
1092	my $string = $_[1];	1588	my $string = $_[1];
1093	$_[0]->unshift_read (chunk => 1, sub {	1589	$_[0]->unshift_read (chunk => 1, sub {
1094	if ($_[1] eq ",") {	1590	if ($_[1] eq ",") {
1095	$cb->($_[0], $string);	1591	$cb->($_[0], $string);
1096	} else {	1592	} else {
1097	$self->_error (&Errno::EBADMSG);	1593	$self->_error (Errno::EBADMSG);
1098	}	1594	}
1099	});	1595	});
1100	});	1596	});
1101		1597
1102	1	1598	1
…		…
1108	An octet string prefixed with an encoded length. The encoding C<$format>	1604	An octet string prefixed with an encoded length. The encoding C<$format>
1109	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
1110	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1606	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1111	optional C<!>, C<< < >> or C<< > >> modifier).	1607	optional C<!>, C<< < >> or C<< > >> modifier).
1112		1608
1113	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).
1114		1611
1115	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
1116	format (very efficient).	1613	format (very efficient).
1117		1614
1118	$handle->push_read (packstring => "w", sub {	1615	$handle->push_read (packstring => "w", sub {
…		…
1148	}	1645	}
1149	};	1646	};
1150		1647
1151	=item json => $cb->($handle, $hash_or_arrayref)	1648	=item json => $cb->($handle, $hash_or_arrayref)
1152		1649
1153	Reads a JSON object or array, decodes it and passes it to the callback.	1650	Reads a JSON object or array, decodes it and passes it to the
		1651	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1154		1652
1155	If a C<json> object was passed to the constructor, then that will be used	1653	If a C<json> object was passed to the constructor, then that will be used
1156	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1654	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1157		1655
1158	This read type uses the incremental parser available with JSON version	1656	This read type uses the incremental parser available with JSON version
…		…
1167	=cut	1665	=cut
1168		1666
1169	register_read_type json => sub {	1667	register_read_type json => sub {
1170	my ($self, $cb) = @_;	1668	my ($self, $cb) = @_;
1171		1669
1172	require JSON;	1670	my $json = $self->{json} ||= json_coder;
1173		1671
1174	my $data;	1672	my $data;
1175	my $rbuf = \$self->{rbuf};	1673	my $rbuf = \$self->{rbuf};
1176		1674
1177	my $json = $self->{json} ||= JSON->new->utf8;
1178
1179	sub {	1675	sub {
1180	my $ref = $json->incr_parse ($self->{rbuf});	1676	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1181		1677
1182	if ($ref) {	1678	if ($ref) {
1183	$self->{rbuf} = $json->incr_text;	1679	$self->{rbuf} = $json->incr_text;
1184	$json->incr_text = "";	1680	$json->incr_text = "";
1185	$cb->($self, $ref);	1681	$cb->($self, $ref);
1186		1682
1187	1	1683	1
		1684	} elsif ($@) {
		1685	# error case
		1686	$json->incr_skip;
		1687
		1688	$self->{rbuf} = $json->incr_text;
		1689	$json->incr_text = "";
		1690
		1691	$self->_error (Errno::EBADMSG);
		1692
		1693	()
1188	} else {	1694	} else {
1189	$self->{rbuf} = "";	1695	$self->{rbuf} = "";
		1696
1190	()	1697	()
1191	}	1698	}
1192	}	1699	}
1193	};	1700	};
1194		1701
…		…
1226	# read remaining chunk	1733	# read remaining chunk
1227	$_[0]->unshift_read (chunk => $len, sub {	1734	$_[0]->unshift_read (chunk => $len, sub {
1228	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1735	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1229	$cb->($_[0], $ref);	1736	$cb->($_[0], $ref);
1230	} else {	1737	} else {
1231	$self->_error (&Errno::EBADMSG);	1738	$self->_error (Errno::EBADMSG);
1232	}	1739	}
1233	});	1740	});
1234	}	1741	}
1235		1742
1236	1	1743	1
1237	}	1744	}
1238	};	1745	};
1239		1746
1240	=back	1747	=back
1241		1748
1242	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1749	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1243		1750
1244	This function (not method) lets you add your own types to C<push_read>.	1751	Instead of one of the predefined types, you can also specify the name
		1752	of a package. AnyEvent will try to load the package and then expects to
		1753	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1754	progressively tries to load the parent package until it either finds the
		1755	function (good) or runs out of packages (bad).
1245		1756
1246	Whenever the given C<type> is used, C<push_read> will invoke the code	1757	Whenever this type is used, C<push_read> will invoke the function with the
1247	reference with the handle object, the callback and the remaining	1758	handle object, the original callback and the remaining arguments.
1248	arguments.
1249		1759
1250	The code reference is supposed to return a callback (usually a closure)	1760	The function is supposed to return a callback (usually a closure) that
1251	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1761	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1762	mentally treat the function as a "configurable read type to read callback"
		1763	converter.
1252		1764
1253	It should invoke the passed callback when it is done reading (remember to	1765	It should invoke the original callback when it is done reading (remember
1254	pass C<$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).
1255		1768
1256	Note that this is a function, and all types registered this way will be
1257	global, so try to use unique names.
1258
1259	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
1260	search for C<register_read_type>)).	1770	AnyEvent::Handle>, search for C<register_read_type>)).
1261		1771
1262	=item $handle->stop_read	1772	=item $handle->stop_read
1263		1773
1264	=item $handle->start_read	1774	=item $handle->start_read
1265		1775
…		…
1271	Note that AnyEvent::Handle will automatically C<start_read> for you when	1781	Note that AnyEvent::Handle will automatically C<start_read> for you when
1272	you change the C<on_read> callback or push/unshift a read callback, and it	1782	you change the C<on_read> callback or push/unshift a read callback, and it
1273	will automatically C<stop_read> for you when neither C<on_read> is set nor	1783	will automatically C<stop_read> for you when neither C<on_read> is set nor
1274	there are any read requests in the queue.	1784	there are any read requests in the queue.
1275		1785
		1786	In older versions of this module (<= 5.3), these methods had no effect,
		1787	as TLS does not support half-duplex connections. In current versions they
		1788	work as expected, as this behaviour is required to avoid certain resource
		1789	attacks, where the program would be forced to read (and buffer) arbitrary
		1790	amounts of data before being able to send some data. The drawback is that
		1791	some readings of the the SSL/TLS specifications basically require this
		1792	attack to be working, as SSL/TLS implementations might stall sending data
		1793	during a rehandshake.
		1794
		1795	As a guideline, during the initial handshake, you should not stop reading,
		1796	and as a client, it might cause problems, depending on your applciation.
		1797
1276	=cut	1798	=cut
1277		1799
1278	sub stop_read {	1800	sub stop_read {
1279	my ($self) = @_;	1801	my ($self) = @_;
1280		1802
…		…
1282	}	1804	}
1283		1805
1284	sub start_read {	1806	sub start_read {
1285	my ($self) = @_;	1807	my ($self) = @_;
1286		1808
1287	unless ($self->{_rw} || $self->{_eof}) {	1809	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1288	Scalar::Util::weaken $self;	1810	Scalar::Util::weaken $self;
1289		1811
1290	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1812	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1291	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1813	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1292	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1814	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1293		1815
1294	if ($len > 0) {	1816	if ($len > 0) {
1295	$self->{_activity} = AnyEvent->now;	1817	$self->{_activity} = $self->{_ractivity} = AE::now;
1296		1818
1297	$self->{filter_r}	1819	if ($self->{tls}) {
1298	? $self->{filter_r}($self, $rbuf)	1820	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1299	: $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	}
1300		1832
1301	} elsif (defined $len) {	1833	} elsif (defined $len) {
1302	delete $self->{_rw};	1834	delete $self->{_rw};
1303	$self->{_eof} = 1;	1835	$self->{_eof} = 1;
1304	$self->_drain_rbuf unless $self->{_in_drain};	1836	$self->_drain_rbuf;
1305		1837
1306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1838	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1307	return $self->_error ($!, 1);	1839	return $self->_error ($!, 1);
1308	}	1840	}
1309	});	1841	};
1310	}	1842	}
1311	}	1843	}
1312		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, $err);
		1865	}
		1866	}
		1867
		1868	# poll the write BIO and send the data if applicable
		1869	# also decode read data if possible
		1870	# this is basiclaly our TLS state machine
		1871	# more efficient implementations are possible with openssl,
		1872	# but not with the buggy and incomplete Net::SSLeay.
1313	sub _dotls {	1873	sub _dotls {
1314	my ($self) = @_;	1874	my ($self) = @_;
1315		1875
1316	my $buf;	1876	my $tmp;
1317		1877
1318	if (length $self->{_tls_wbuf}) {	1878	if (length $self->{_tls_wbuf}) {
1319	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1879	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1320	substr $self->{_tls_wbuf}, 0, $len, "";	1880	substr $self->{_tls_wbuf}, 0, $tmp, "";
1321	}	1881	}
1322	}
1323		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 || $!);
		1914
1324	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1915	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1325	$self->{wbuf} .= $buf;	1916	$self->{wbuf} .= $tmp;
1326	$self->_drain_wbuf;	1917	$self->_drain_wbuf;
		1918	$self->{tls} or return; # tls session might have gone away in callback
1327	}	1919	}
1328		1920
1329	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1921	$self->{_on_starttls}
1330	if (length $buf) {	1922	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1331	$self->{rbuf} .= $buf;	1923	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1332	$self->_drain_rbuf unless $self->{_in_drain};
1333	} else {
1334	# let's treat SSL-eof as we treat normal EOF
1335	$self->{_eof} = 1;
1336	$self->_shutdown;
1337	return;
1338	}
1339	}
1340
1341	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1342
1343	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1344	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1345	return $self->_error ($!, 1);
1346	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1347	return $self->_error (&Errno::EIO, 1);
1348	}
1349
1350	# all others are fine for our purposes
1351	}
1352	}	1924	}
1353		1925
1354	=item $handle->starttls ($tls[, $tls_ctx])	1926	=item $handle->starttls ($tls[, $tls_ctx])
1355		1927
1356	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1928	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1357	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
1358	C<starttls>.	1930	C<starttls>.
1359		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
1360	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
1361	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1937	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1362		1938
1363	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
1364	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.
1365		1943
1366	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
1367	call and can be used or changed to your liking. Note that the handshake	1945	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1368	might have already started when this function returns.	1946	changed to your liking. Note that the handshake might have already started
		1947	when this function returns.
1369		1948
		1949	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1950	handshakes on the same stream. It is best to not attempt to use the
		1951	stream after stopping TLS.
		1952
		1953	This method may invoke callbacks (and therefore the handle might be
		1954	destroyed after it returns).
		1955
1370	=cut	1956	=cut
		1957
		1958	our %TLS_CACHE; #TODO not yet documented, should we?
1371		1959
1372	sub starttls {	1960	sub starttls {
1373	my ($self, $ssl, $ctx) = @_;	1961	my ($self, $tls, $ctx) = @_;
1374		1962
1375	$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 $self->{tls};
1376		1965
1377	if ($ssl eq "accept") {	1966	$self->{tls} = $tls;
1378	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1967	$self->{tls_ctx} = $ctx if @_ > 2;
1379	Net::SSLeay::set_accept_state ($ssl);	1968
1380	} elsif ($ssl eq "connect") {	1969	return unless $self->{fh};
1381	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1970
1382	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	}
1383	}	1991
1384		1992	$self->{tls_ctx} = $ctx || TLS_CTX ();
1385	$self->{tls} = $ssl;	1993	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1386		1994
1387	# basically, this is deep magic (because SSL_read should have the same issues)	1995	# basically, this is deep magic (because SSL_read should have the same issues)
1388	# but the openssl maintainers basically said: "trust us, it just works".	1996	# but the openssl maintainers basically said: "trust us, it just works".
1389	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1997	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1390	# and mismaintained ssleay-module doesn't even offer them).	1998	# and mismaintained ssleay-module doesn't even offer them).
1391	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1999	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1392	#	2000	#
1393	# in short: this is a mess.	2001	# in short: this is a mess.
1394	#	2002	#
1395	# note that we do not try to kepe the length constant between writes as we are required to do.	2003	# note that we do not try to keep the length constant between writes as we are required to do.
1396	# we assume that most (but not all) of this insanity only applies to non-blocking cases,	2004	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
1397	# and we drive openssl fully in blocking mode here.	2005	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2006	# have identity issues in that area.
1398	Net::SSLeay::CTX_set_mode ($self->{tls},	2007	# Net::SSLeay::CTX_set_mode ($ssl,
1399	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2008	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1400	| (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);
1401		2011
1402	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2012	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1403	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1404		2014
		2015	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		2016
1405	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2017	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1406		2018
1407	$self->{filter_w} = sub {	2019	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1408	$_[0]{_tls_wbuf} .= ${$_[1]};	2020	if $self->{on_starttls};
1409	&_dotls;	2021
1410	};	2022	&_dotls; # need to trigger the initial handshake
1411	$self->{filter_r} = sub {	2023	$self->start_read; # make sure we actually do read
1412	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1413	&_dotls;
1414	};
1415	}	2024	}
1416		2025
1417	=item $handle->stoptls	2026	=item $handle->stoptls
1418		2027
1419	Destroys the SSL connection, if any. Partial read or write data will be	2028	Shuts down the SSL connection - this makes a proper EOF handshake by
1420	lost.	2029	sending a close notify to the other side, but since OpenSSL doesn't
		2030	support non-blocking shut downs, it is not guaranteed that you can re-use
		2031	the stream afterwards.
		2032
		2033	This method may invoke callbacks (and therefore the handle might be
		2034	destroyed after it returns).
1421		2035
1422	=cut	2036	=cut
1423		2037
1424	sub stoptls {	2038	sub stoptls {
1425	my ($self) = @_;	2039	my ($self) = @_;
1426		2040
1427	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2041	if ($self->{tls} && $self->{fh}) {
		2042	Net::SSLeay::shutdown ($self->{tls});
1428		2043
1429	delete $self->{_rbio};	2044	&_dotls;
1430	delete $self->{_wbio};	2045
1431	delete $self->{_tls_wbuf};	2046	# # we don't give a shit. no, we do, but we can't. no...#d#
1432	delete $self->{filter_r};	2047	# # we, we... have to use openssl :/#d#
1433	delete $self->{filter_w};	2048	# &_freetls;#d#
		2049	}
1434	}	2050	}
		2051
		2052	sub _freetls {
		2053	my ($self) = @_;
		2054
		2055	return unless $self->{tls};
		2056
		2057	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2058	if $self->{tls} > 0;
		2059
		2060	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2061	}
		2062
		2063	=item $handle->resettls
		2064
		2065	This rarely-used method simply resets and TLS state on the handle, usually
		2066	causing data loss.
		2067
		2068	One case where it may be useful is when you want to skip over the data in
		2069	the stream but you are not interested in interpreting it, so data loss is
		2070	no concern.
		2071
		2072	=cut
		2073
		2074	*resettls = \&_freetls;
1435		2075
1436	sub DESTROY {	2076	sub DESTROY {
1437	my $self = shift;	2077	my ($self) = @_;
1438		2078
1439	$self->stoptls;	2079	&_freetls;
1440		2080
1441	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2081	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1442		2082
1443	if ($linger && length $self->{wbuf}) {	2083	if ($linger && length $self->{wbuf} && $self->{fh}) {
1444	my $fh = delete $self->{fh};	2084	my $fh = delete $self->{fh};
1445	my $wbuf = delete $self->{wbuf};	2085	my $wbuf = delete $self->{wbuf};
1446		2086
1447	my @linger;	2087	my @linger;
1448		2088
1449	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2089	push @linger, AE::io $fh, 1, sub {
1450	my $len = syswrite $fh, $wbuf, length $wbuf;	2090	my $len = syswrite $fh, $wbuf, length $wbuf;
1451		2091
1452	if ($len > 0) {	2092	if ($len > 0) {
1453	substr $wbuf, 0, $len, "";	2093	substr $wbuf, 0, $len, "";
1454	} else {	2094	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1455	@linger = (); # end	2095	@linger = (); # end
1456	}	2096	}
		2097	};
		2098	push @linger, AE::timer $linger, 0, sub {
		2099	@linger = ();
		2100	};
		2101	}
		2102	}
		2103
		2104	=item $handle->destroy
		2105
		2106	Shuts down the handle object as much as possible - this call ensures that
		2107	no further callbacks will be invoked and as many resources as possible
		2108	will be freed. Any method you will call on the handle object after
		2109	destroying it in this way will be silently ignored (and it will return the
		2110	empty list).
		2111
		2112	Normally, you can just "forget" any references to an AnyEvent::Handle
		2113	object and it will simply shut down. This works in fatal error and EOF
		2114	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2115	callback, so when you want to destroy the AnyEvent::Handle object from
		2116	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2117	that case.
		2118
		2119	Destroying the handle object in this way has the advantage that callbacks
		2120	will be removed as well, so if those are the only reference holders (as
		2121	is common), then one doesn't need to do anything special to break any
		2122	reference cycles.
		2123
		2124	The handle might still linger in the background and write out remaining
		2125	data, as specified by the C<linger> option, however.
		2126
		2127	=cut
		2128
		2129	sub destroy {
		2130	my ($self) = @_;
		2131
		2132	$self->DESTROY;
		2133	%$self = ();
		2134	bless $self, "AnyEvent::Handle::destroyed";
		2135	}
		2136
		2137	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2138	#nop
		2139	}
		2140
		2141	=item $handle->destroyed
		2142
		2143	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2144	->destroy >>, true otherwise.
		2145
		2146	Can be useful to decide whether the handle is still valid after some
		2147	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2148	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2149	can destroy the handle, so work can be avoided by checking sometimes:
		2150
		2151	$hdl->starttls ("accept");
		2152	return if $hdl->destroyed;
		2153	$hdl->push_write (...
		2154
		2155	Note that the call to C<push_write> will silently be ignored if the handle
		2156	has been destroyed, so often you can just ignore the possibility of the
		2157	handle being destroyed.
		2158
		2159	=cut
		2160
		2161	sub destroyed { 0 }
		2162	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2163
		2164	=item AnyEvent::Handle::TLS_CTX
		2165
		2166	This function creates and returns the AnyEvent::TLS object used by default
		2167	for TLS mode.
		2168
		2169	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2170
		2171	=cut
		2172
		2173	our $TLS_CTX;
		2174
		2175	sub TLS_CTX() {
		2176	$TLS_CTX ||= do {
		2177	require AnyEvent::TLS;
		2178
		2179	new AnyEvent::TLS
		2180	}
		2181	}
		2182
		2183	=back
		2184
		2185
		2186	=head1 NONFREQUENTLY ASKED QUESTIONS
		2187
		2188	=over 4
		2189
		2190	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2191	still get further invocations!
		2192
		2193	That's because AnyEvent::Handle keeps a reference to itself when handling
		2194	read or write callbacks.
		2195
		2196	It is only safe to "forget" the reference inside EOF or error callbacks,
		2197	from within all other callbacks, you need to explicitly call the C<<
		2198	->destroy >> method.
		2199
		2200	=item Why is my C<on_eof> callback never called?
		2201
		2202	Probably because your C<on_error> callback is being called instead: When
		2203	you have outstanding requests in your read queue, then an EOF is
		2204	considered an error as you clearly expected some data.
		2205
		2206	To avoid this, make sure you have an empty read queue whenever your handle
		2207	is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
		2208	an C<on_read> handler that simply pushes the first read requests in the
		2209	queue.
		2210
		2211	See also the next question, which explains this in a bit more detail.
		2212
		2213	=item How can I serve requests in a loop?
		2214
		2215	Most protocols consist of some setup phase (authentication for example)
		2216	followed by a request handling phase, where the server waits for requests
		2217	and handles them, in a loop.
		2218
		2219	There are two important variants: The first (traditional, better) variant
		2220	handles requests until the server gets some QUIT command, causing it to
		2221	close the connection first (highly desirable for a busy TCP server). A
		2222	client dropping the connection is an error, which means this variant can
		2223	detect an unexpected detection close.
		2224
		2225	To handle this case, always make sure you have a on-empty read queue, by
		2226	pushing the "read request start" handler on it:
		2227
		2228	# we assume a request starts with a single line
		2229	my @start_request; @start_request = (line => sub {
		2230	my ($hdl, $line) = @_;
		2231
		2232	... handle request
		2233
		2234	# push next request read, possibly from a nested callback
		2235	$hdl->push_read (@start_request);
		2236	});
		2237
		2238	# auth done, now go into request handling loop
		2239	# now push the first @start_request
		2240	$hdl->push_read (@start_request);
		2241
		2242	By always having an outstanding C<push_read>, the handle always expects
		2243	some data and raises the C<EPIPE> error when the connction is dropped
		2244	unexpectedly.
		2245
		2246	The second variant is a protocol where the client can drop the connection
		2247	at any time. For TCP, this means that the server machine may run out of
		2248	sockets easier, and in general, it means you cnanot distinguish a protocl
		2249	failure/client crash from a normal connection close. Nevertheless, these
		2250	kinds of protocols are common (and sometimes even the best solution to the
		2251	problem).
		2252
		2253	Having an outstanding read request at all times is possible if you ignore
		2254	C<EPIPE> errors, but this doesn't help with when the client drops the
		2255	connection during a request, which would still be an error.
		2256
		2257	A better solution is to push the initial request read in an C<on_read>
		2258	callback. This avoids an error, as when the server doesn't expect data
		2259	(i.e. is idly waiting for the next request, an EOF will not raise an
		2260	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2261	and simpler:
		2262
		2263	# auth done, now go into request handling loop
		2264	$hdl->on_read (sub {
		2265	my ($hdl) = @_;
		2266
		2267	# called each time we receive data but the read queue is empty
		2268	# simply start read the request
		2269
		2270	$hdl->push_read (line => sub {
		2271	my ($hdl, $line) = @_;
		2272
		2273	... handle request
		2274
		2275	# do nothing special when the request has been handled, just
		2276	# let the request queue go empty.
1457	});	2277	});
1458	push @linger, AnyEvent->timer (after => $linger, cb => sub {
1459	@linger = ();
1460	});	2278	});
		2279
		2280	=item I get different callback invocations in TLS mode/Why can't I pause
		2281	reading?
		2282
		2283	Unlike, say, TCP, TLS connections do not consist of two independent
		2284	communication channels, one for each direction. Or put differently, the
		2285	read and write directions are not independent of each other: you cannot
		2286	write data unless you are also prepared to read, and vice versa.
		2287
		2288	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2289	callback invocations when you are not expecting any read data - the reason
		2290	is that AnyEvent::Handle always reads in TLS mode.
		2291
		2292	During the connection, you have to make sure that you always have a
		2293	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2294	connection (or when you no longer want to use it) you can call the
		2295	C<destroy> method.
		2296
		2297	=item How do I read data until the other side closes the connection?
		2298
		2299	If you just want to read your data into a perl scalar, the easiest way
		2300	to achieve this is by setting an C<on_read> callback that does nothing,
		2301	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2302	will be in C<$_[0]{rbuf}>:
		2303
		2304	$handle->on_read (sub { });
		2305	$handle->on_eof (undef);
		2306	$handle->on_error (sub {
		2307	my $data = delete $_[0]{rbuf};
		2308	});
		2309
		2310	The reason to use C<on_error> is that TCP connections, due to latencies
		2311	and packets loss, might get closed quite violently with an error, when in
		2312	fact all data has been received.
		2313
		2314	It is usually better to use acknowledgements when transferring data,
		2315	to make sure the other side hasn't just died and you got the data
		2316	intact. This is also one reason why so many internet protocols have an
		2317	explicit QUIT command.
		2318
		2319	=item I don't want to destroy the handle too early - how do I wait until
		2320	all data has been written?
		2321
		2322	After writing your last bits of data, set the C<on_drain> callback
		2323	and destroy the handle in there - with the default setting of
		2324	C<low_water_mark> this will be called precisely when all data has been
		2325	written to the socket:
		2326
		2327	$handle->push_write (...);
		2328	$handle->on_drain (sub {
		2329	warn "all data submitted to the kernel\n";
		2330	undef $handle;
		2331	});
		2332
		2333	If you just want to queue some data and then signal EOF to the other side,
		2334	consider using C<< ->push_shutdown >> instead.
		2335
		2336	=item I want to contact a TLS/SSL server, I don't care about security.
		2337
		2338	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2339	connect to it and then create the AnyEvent::Handle with the C<tls>
		2340	parameter:
		2341
		2342	tcp_connect $host, $port, sub {
		2343	my ($fh) = @_;
		2344
		2345	my $handle = new AnyEvent::Handle
		2346	fh => $fh,
		2347	tls => "connect",
		2348	on_error => sub { ... };
		2349
		2350	$handle->push_write (...);
1461	}	2351	};
1462	}
1463		2352
1464	=item AnyEvent::Handle::TLS_CTX	2353	=item I want to contact a TLS/SSL server, I do care about security.
1465		2354
1466	This function creates and returns the Net::SSLeay::CTX object used by	2355	Then you should additionally enable certificate verification, including
1467	default for TLS mode.	2356	peername verification, if the protocol you use supports it (see
		2357	L<AnyEvent::TLS>, C<verify_peername>).
1468		2358
1469	The context is created like this:	2359	E.g. for HTTPS:
1470		2360
1471	Net::SSLeay::load_error_strings;	2361	tcp_connect $host, $port, sub {
1472	Net::SSLeay::SSLeay_add_ssl_algorithms;	2362	my ($fh) = @_;
1473	Net::SSLeay::randomize;
1474		2363
1475	my $CTX = Net::SSLeay::CTX_new;	2364	my $handle = new AnyEvent::Handle
		2365	fh => $fh,
		2366	peername => $host,
		2367	tls => "connect",
		2368	tls_ctx => { verify => 1, verify_peername => "https" },
		2369	...
1476		2370
1477	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL	2371	Note that you must specify the hostname you connected to (or whatever
		2372	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2373	peername verification will be done.
1478		2374
1479	=cut	2375	The above will use the system-dependent default set of trusted CA
		2376	certificates. If you want to check against a specific CA, add the
		2377	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1480		2378
1481	our $TLS_CTX;	2379	tls_ctx => {
		2380	verify => 1,
		2381	verify_peername => "https",
		2382	ca_file => "my-ca-cert.pem",
		2383	},
1482		2384
1483	sub TLS_CTX() {	2385	=item I want to create a TLS/SSL server, how do I do that?
1484	$TLS_CTX || do {
1485	require Net::SSLeay;
1486		2386
1487	Net::SSLeay::load_error_strings ();	2387	Well, you first need to get a server certificate and key. You have
1488	Net::SSLeay::SSLeay_add_ssl_algorithms ();	2388	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1489	Net::SSLeay::randomize ();	2389	self-signed certificate (cheap. check the search engine of your choice,
		2390	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2391	nice program for that purpose).
1490		2392
1491	$TLS_CTX = Net::SSLeay::CTX_new ();	2393	Then create a file with your private key (in PEM format, see
		2394	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2395	file should then look like this:
1492		2396
1493	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());	2397	-----BEGIN RSA PRIVATE KEY-----
		2398	...header data
		2399	... lots of base64'y-stuff
		2400	-----END RSA PRIVATE KEY-----
1494		2401
1495	$TLS_CTX	2402	-----BEGIN CERTIFICATE-----
1496	}	2403	... lots of base64'y-stuff
1497	}	2404	-----END CERTIFICATE-----
		2405
		2406	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2407	specify this file as C<cert_file>:
		2408
		2409	tcp_server undef, $port, sub {
		2410	my ($fh) = @_;
		2411
		2412	my $handle = new AnyEvent::Handle
		2413	fh => $fh,
		2414	tls => "accept",
		2415	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2416	...
		2417
		2418	When you have intermediate CA certificates that your clients might not
		2419	know about, just append them to the C<cert_file>.
1498		2420
1499	=back	2421	=back
		2422
1500		2423
1501	=head1 SUBCLASSING AnyEvent::Handle	2424	=head1 SUBCLASSING AnyEvent::Handle
1502		2425
1503	In many cases, you might want to subclass AnyEvent::Handle.	2426	In many cases, you might want to subclass AnyEvent::Handle.
1504		2427
…		…
1521		2444
1522	=item * all members not documented here and not prefixed with an underscore	2445	=item * all members not documented here and not prefixed with an underscore
1523	are free to use in subclasses.	2446	are free to use in subclasses.
1524		2447
1525	Of course, new versions of AnyEvent::Handle may introduce more "public"	2448	Of course, new versions of AnyEvent::Handle may introduce more "public"
1526	member variables, but thats just life, at least it is documented.	2449	member variables, but that's just life. At least it is documented.
1527		2450
1528	=back	2451	=back
1529		2452
1530	=head1 AUTHOR	2453	=head1 AUTHOR
1531		2454

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