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Revision 1.222 by root, Thu Aug 25 03:08:48 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 = 4.3;
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $handle =	12	my $hdl; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
32	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
33	},	16	AE::log 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	AE::log 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
222	try to read during each loop iteration, which affects memory	365	to read during each loop iteration. Each handle object will consume
223	requirements). Default: C<8192>.	366	at least this amount of memory for the read buffer as well, so when
		367	handling many connections watch out for memory requirements). See also
		368	C<max_read_size>. Default: C<2048>.
		369
		370	=item max_read_size => <bytes>
		371
		372	The maximum read buffer size used by the dynamic adjustment
		373	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		374	one go it will double C<read_size> up to the maximum given by this
		375	option. Default: C<131072> or C<read_size>, whichever is higher.
224		376
225	=item low_water_mark => <bytes>	377	=item low_water_mark => <bytes>
226		378
227	Sets the amount of bytes (default: C<0>) that make up an "empty" write	379	Sets the number of bytes (default: C<0>) that make up an "empty" write
228	buffer: If the write reaches this size or gets even samller it is	380	buffer: If the buffer reaches this size or gets even samller it is
229	considered empty.	381	considered empty.
230		382
231	Sometimes it can be beneficial (for performance reasons) to add data to	383	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	384	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	385	the operating system kernel usually buffers data as well, so the default
234	is good in almost all cases.	386	is good in almost all cases.
235		387
236	=item linger => <seconds>	388	=item linger => <seconds>
237		389
238	If non-zero (default: C<3600>), then the destructor of the	390	If this is non-zero (default: C<3600>), the destructor of the
239	AnyEvent::Handle object will check whether there is still outstanding	391	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	392	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	393	socket. No errors will be reported (this mostly matches how the operating
242	system treats outstanding data at socket close time).	394	system treats outstanding data at socket close time).
243		395
244	This will not work for partial TLS data that could not be encoded	396	This will not work for partial TLS data that could not be encoded
245	yet. This data will be lost. Calling the C<stoptls> method in time might	397	yet. This data will be lost. Calling the C<stoptls> method in time might
246	help.	398	help.
247		399
		400	=item peername => $string
		401
		402	A string used to identify the remote site - usually the DNS hostname
		403	(I<not> IDN!) used to create the connection, rarely the IP address.
		404
		405	Apart from being useful in error messages, this string is also used in TLS
		406	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		407	verification will be skipped when C<peername> is not specified or is
		408	C<undef>.
		409
248	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	410	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
249		411
250	When this parameter is given, it enables TLS (SSL) mode, that means	412	When this parameter is given, it enables TLS (SSL) mode, that means
251	AnyEvent will start a TLS handshake as soon as the conenction has been	413	AnyEvent will start a TLS handshake as soon as the connection has been
252	established and will transparently encrypt/decrypt data afterwards.	414	established and will transparently encrypt/decrypt data afterwards.
		415
		416	All TLS protocol errors will be signalled as C<EPROTO>, with an
		417	appropriate error message.
253		418
254	TLS mode requires Net::SSLeay to be installed (it will be loaded	419	TLS mode requires Net::SSLeay to be installed (it will be loaded
255	automatically when you try to create a TLS handle): this module doesn't	420	automatically when you try to create a TLS handle): this module doesn't
256	have a dependency on that module, so if your module requires it, you have	421	have a dependency on that module, so if your module requires it, you have
257	to add the dependency yourself.	422	to add the dependency yourself.
…		…
261	mode.	426	mode.
262		427
263	You can also provide your own TLS connection object, but you have	428	You can also provide your own TLS connection object, but you have
264	to make sure that you call either C<Net::SSLeay::set_connect_state>	429	to make sure that you call either C<Net::SSLeay::set_connect_state>
265	or C<Net::SSLeay::set_accept_state> on it before you pass it to	430	or C<Net::SSLeay::set_accept_state> on it before you pass it to
266	AnyEvent::Handle.	431	AnyEvent::Handle. Also, this module will take ownership of this connection
		432	object.
267		433
		434	At some future point, AnyEvent::Handle might switch to another TLS
		435	implementation, then the option to use your own session object will go
		436	away.
		437
		438	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		439	passing in the wrong integer will lead to certain crash. This most often
		440	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		441	segmentation fault.
		442
268	See the C<< ->starttls >> method for when need to start TLS negotiation later.	443	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
269		444
270	=item tls_ctx => $ssl_ctx	445	=item tls_ctx => $anyevent_tls
271		446
272	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection	447	Use the given C<AnyEvent::TLS> object to create the new TLS connection
273	(unless a connection object was specified directly). If this parameter is	448	(unless a connection object was specified directly). If this
274	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	449	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		450	C<AnyEvent::Handle::TLS_CTX>.
		451
		452	Instead of an object, you can also specify a hash reference with C<< key
		453	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		454	new TLS context object.
		455
		456	=item on_starttls => $cb->($handle, $success[, $error_message])
		457
		458	This callback will be invoked when the TLS/SSL handshake has finished. If
		459	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		460	(C<on_stoptls> will not be called in this case).
		461
		462	The session in C<< $handle->{tls} >> can still be examined in this
		463	callback, even when the handshake was not successful.
		464
		465	TLS handshake failures will not cause C<on_error> to be invoked when this
		466	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		467
		468	Without this callback, handshake failures lead to C<on_error> being
		469	called as usual.
		470
		471	Note that you cannot just call C<starttls> again in this callback. If you
		472	need to do that, start an zero-second timer instead whose callback can
		473	then call C<< ->starttls >> again.
		474
		475	=item on_stoptls => $cb->($handle)
		476
		477	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		478	set, then it will be invoked after freeing the TLS session. If it is not,
		479	then a TLS shutdown condition will be treated like a normal EOF condition
		480	on the handle.
		481
		482	The session in C<< $handle->{tls} >> can still be examined in this
		483	callback.
		484
		485	This callback will only be called on TLS shutdowns, not when the
		486	underlying handle signals EOF.
275		487
276	=item json => JSON or JSON::XS object	488	=item json => JSON or JSON::XS object
277		489
278	This is the json coder object used by the C<json> read and write types.	490	This is the json coder object used by the C<json> read and write types.
279		491
…		…
288		500
289	=cut	501	=cut
290		502
291	sub new {	503	sub new {
292	my $class = shift;	504	my $class = shift;
293
294	my $self = bless { @_ }, $class;	505	my $self = bless { @_ }, $class;
295		506
296	$self->{fh} or Carp::croak "mandatory argument fh is missing";	507	if ($self->{fh}) {
		508	$self->_start;
		509	return unless $self->{fh}; # could be gone by now
		510
		511	} elsif ($self->{connect}) {
		512	require AnyEvent::Socket;
		513
		514	$self->{peername} = $self->{connect}[0]
		515	unless exists $self->{peername};
		516
		517	$self->{_skip_drain_rbuf} = 1;
		518
		519	{
		520	Scalar::Util::weaken (my $self = $self);
		521
		522	$self->{_connect} =
		523	AnyEvent::Socket::tcp_connect (
		524	$self->{connect}[0],
		525	$self->{connect}[1],
		526	sub {
		527	my ($fh, $host, $port, $retry) = @_;
		528
		529	delete $self->{_connect}; # no longer needed
		530
		531	if ($fh) {
		532	$self->{fh} = $fh;
		533
		534	delete $self->{_skip_drain_rbuf};
		535	$self->_start;
		536
		537	$self->{on_connect}
		538	and $self->{on_connect}($self, $host, $port, sub {
		539	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		540	$self->{_skip_drain_rbuf} = 1;
		541	&$retry;
		542	});
		543
		544	} else {
		545	if ($self->{on_connect_error}) {
		546	$self->{on_connect_error}($self, "$!");
		547	$self->destroy if $self;
		548	} else {
		549	$self->_error ($!, 1);
		550	}
		551	}
		552	},
		553	sub {
		554	local $self->{fh} = $_[0];
		555
		556	$self->{on_prepare}
		557	? $self->{on_prepare}->($self)
		558	: ()
		559	}
		560	);
		561	}
		562
		563	} else {
		564	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		565	}
		566
		567	$self
		568	}
		569
		570	sub _start {
		571	my ($self) = @_;
		572
		573	# too many clueless people try to use udp and similar sockets
		574	# with AnyEvent::Handle, do them a favour.
		575	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		576	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		577	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
297		578
298	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	579	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
299		580
300	if ($self->{tls}) {	581	$self->{_activity} =
301	require Net::SSLeay;	582	$self->{_ractivity} =
		583	$self->{_wactivity} = AE::now;
		584
		585	$self->{read_size} ||= 2048;
		586	$self->{max_read_size} = $self->{read_size}
		587	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		588
		589	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		590	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		591	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		592
		593	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		594	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		595
		596	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		597
302	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	598	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
303	}	599	if $self->{tls};
304		600
305	$self->{_activity} = AnyEvent->now;
306	$self->_timeout;
307
308	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	601	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
309	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
310		602
311	$self->start_read	603	$self->start_read
312	if $self->{on_read};	604	if $self->{on_read} || @{ $self->{_queue} };
313		605
314	$self	606	$self->_drain_wbuf;
315	}
316
317	sub _shutdown {
318	my ($self) = @_;
319
320	delete $self->{_tw};
321	delete $self->{_rw};
322	delete $self->{_ww};
323	delete $self->{fh};
324
325	&_freetls;
326
327	delete $self->{on_read};
328	delete $self->{_queue};
329	}	607	}
330		608
331	sub _error {	609	sub _error {
332	my ($self, $errno, $fatal) = @_;	610	my ($self, $errno, $fatal, $message) = @_;
333
334	$self->_shutdown
335	if $fatal;
336		611
337	$! = $errno;	612	$! = $errno;
		613	$message ||= "$!";
338		614
339	if ($self->{on_error}) {	615	if ($self->{on_error}) {
340	$self->{on_error}($self, $fatal);	616	$self->{on_error}($self, $fatal, $message);
341	} else {	617	$self->destroy if $fatal;
		618	} elsif ($self->{fh} || $self->{connect}) {
		619	$self->destroy;
342	Carp::croak "AnyEvent::Handle uncaught error: $!";	620	Carp::croak "AnyEvent::Handle uncaught error: $message";
343	}	621	}
344	}	622	}
345		623
346	=item $fh = $handle->fh	624	=item $fh = $handle->fh
347		625
…		…
371	$_[0]{on_eof} = $_[1];	649	$_[0]{on_eof} = $_[1];
372	}	650	}
373		651
374	=item $handle->on_timeout ($cb)	652	=item $handle->on_timeout ($cb)
375		653
376	Replace the current C<on_timeout> callback, or disables the callback (but	654	=item $handle->on_rtimeout ($cb)
377	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
378	argument and method.
379		655
380	=cut	656	=item $handle->on_wtimeout ($cb)
381		657
382	sub on_timeout {	658	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
383	$_[0]{on_timeout} = $_[1];	659	callback, or disables the callback (but not the timeout) if C<$cb> =
384	}	660	C<undef>. See the C<timeout> constructor argument and method.
		661
		662	=cut
		663
		664	# see below
385		665
386	=item $handle->autocork ($boolean)	666	=item $handle->autocork ($boolean)
387		667
388	Enables or disables the current autocork behaviour (see C<autocork>	668	Enables or disables the current autocork behaviour (see C<autocork>
389	constructor argument).	669	constructor argument). Changes will only take effect on the next write.
390		670
391	=cut	671	=cut
		672
		673	sub autocork {
		674	$_[0]{autocork} = $_[1];
		675	}
392		676
393	=item $handle->no_delay ($boolean)	677	=item $handle->no_delay ($boolean)
394		678
395	Enables or disables the C<no_delay> setting (see constructor argument of	679	Enables or disables the C<no_delay> setting (see constructor argument of
396	the same name for details).	680	the same name for details).
…		…
398	=cut	682	=cut
399		683
400	sub no_delay {	684	sub no_delay {
401	$_[0]{no_delay} = $_[1];	685	$_[0]{no_delay} = $_[1];
402		686
		687	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		688	if $_[0]{fh};
		689	}
		690
		691	=item $handle->keepalive ($boolean)
		692
		693	Enables or disables the C<keepalive> setting (see constructor argument of
		694	the same name for details).
		695
		696	=cut
		697
		698	sub keepalive {
		699	$_[0]{keepalive} = $_[1];
		700
403	eval {	701	eval {
404	local $SIG{__DIE__};	702	local $SIG{__DIE__};
405	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];	703	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		704	if $_[0]{fh};
406	};	705	};
407	}	706	}
408		707
		708	=item $handle->oobinline ($boolean)
		709
		710	Enables or disables the C<oobinline> setting (see constructor argument of
		711	the same name for details).
		712
		713	=cut
		714
		715	sub oobinline {
		716	$_[0]{oobinline} = $_[1];
		717
		718	eval {
		719	local $SIG{__DIE__};
		720	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		721	if $_[0]{fh};
		722	};
		723	}
		724
		725	=item $handle->keepalive ($boolean)
		726
		727	Enables or disables the C<keepalive> setting (see constructor argument of
		728	the same name for details).
		729
		730	=cut
		731
		732	sub keepalive {
		733	$_[0]{keepalive} = $_[1];
		734
		735	eval {
		736	local $SIG{__DIE__};
		737	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		738	if $_[0]{fh};
		739	};
		740	}
		741
		742	=item $handle->on_starttls ($cb)
		743
		744	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		745
		746	=cut
		747
		748	sub on_starttls {
		749	$_[0]{on_starttls} = $_[1];
		750	}
		751
		752	=item $handle->on_stoptls ($cb)
		753
		754	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		755
		756	=cut
		757
		758	sub on_stoptls {
		759	$_[0]{on_stoptls} = $_[1];
		760	}
		761
		762	=item $handle->rbuf_max ($max_octets)
		763
		764	Configures the C<rbuf_max> setting (C<undef> disables it).
		765
		766	=item $handle->wbuf_max ($max_octets)
		767
		768	Configures the C<wbuf_max> setting (C<undef> disables it).
		769
		770	=cut
		771
		772	sub rbuf_max {
		773	$_[0]{rbuf_max} = $_[1];
		774	}
		775
		776	sub wbuf_max {
		777	$_[0]{wbuf_max} = $_[1];
		778	}
		779
409	#############################################################################	780	#############################################################################
410		781
411	=item $handle->timeout ($seconds)	782	=item $handle->timeout ($seconds)
412		783
		784	=item $handle->rtimeout ($seconds)
		785
		786	=item $handle->wtimeout ($seconds)
		787
413	Configures (or disables) the inactivity timeout.	788	Configures (or disables) the inactivity timeout.
414		789
415	=cut	790	The timeout will be checked instantly, so this method might destroy the
		791	handle before it returns.
416		792
417	sub timeout {	793	=item $handle->timeout_reset
		794
		795	=item $handle->rtimeout_reset
		796
		797	=item $handle->wtimeout_reset
		798
		799	Reset the activity timeout, as if data was received or sent.
		800
		801	These methods are cheap to call.
		802
		803	=cut
		804
		805	for my $dir ("", "r", "w") {
		806	my $timeout = "${dir}timeout";
		807	my $tw = "_${dir}tw";
		808	my $on_timeout = "on_${dir}timeout";
		809	my $activity = "_${dir}activity";
		810	my $cb;
		811
		812	*$on_timeout = sub {
		813	$_[0]{$on_timeout} = $_[1];
		814	};
		815
		816	*$timeout = sub {
418	my ($self, $timeout) = @_;	817	my ($self, $new_value) = @_;
419		818
		819	$new_value >= 0
		820	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		821
420	$self->{timeout} = $timeout;	822	$self->{$timeout} = $new_value;
421	$self->_timeout;	823	delete $self->{$tw}; &$cb;
422	}	824	};
423		825
		826	*{"${dir}timeout_reset"} = sub {
		827	$_[0]{$activity} = AE::now;
		828	};
		829
		830	# main workhorse:
424	# reset the timeout watcher, as neccessary	831	# reset the timeout watcher, as neccessary
425	# also check for time-outs	832	# also check for time-outs
426	sub _timeout {	833	$cb = sub {
427	my ($self) = @_;	834	my ($self) = @_;
428		835
429	if ($self->{timeout}) {	836	if ($self->{$timeout} && $self->{fh}) {
430	my $NOW = AnyEvent->now;	837	my $NOW = AE::now;
431		838
432	# when would the timeout trigger?	839	# when would the timeout trigger?
433	my $after = $self->{_activity} + $self->{timeout} - $NOW;	840	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
434		841
435	# now or in the past already?	842	# now or in the past already?
436	if ($after <= 0) {	843	if ($after <= 0) {
437	$self->{_activity} = $NOW;	844	$self->{$activity} = $NOW;
438		845
439	if ($self->{on_timeout}) {	846	if ($self->{$on_timeout}) {
440	$self->{on_timeout}($self);	847	$self->{$on_timeout}($self);
441	} else {	848	} else {
442	$self->_error (&Errno::ETIMEDOUT);	849	$self->_error (Errno::ETIMEDOUT);
		850	}
		851
		852	# callback could have changed timeout value, optimise
		853	return unless $self->{$timeout};
		854
		855	# calculate new after
		856	$after = $self->{$timeout};
443	}	857	}
444		858
445	# callback could have changed timeout value, optimise	859	Scalar::Util::weaken $self;
446	return unless $self->{timeout};	860	return unless $self; # ->error could have destroyed $self
447		861
448	# calculate new after	862	$self->{$tw} ||= AE::timer $after, 0, sub {
449	$after = $self->{timeout};	863	delete $self->{$tw};
		864	$cb->($self);
		865	};
		866	} else {
		867	delete $self->{$tw};
450	}	868	}
451
452	Scalar::Util::weaken $self;
453	return unless $self; # ->error could have destroyed $self
454
455	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
456	delete $self->{_tw};
457	$self->_timeout;
458	});
459	} else {
460	delete $self->{_tw};
461	}	869	}
462	}	870	}
463		871
464	#############################################################################	872	#############################################################################
465		873
…		…
481	=item $handle->on_drain ($cb)	889	=item $handle->on_drain ($cb)
482		890
483	Sets the C<on_drain> callback or clears it (see the description of	891	Sets the C<on_drain> callback or clears it (see the description of
484	C<on_drain> in the constructor).	892	C<on_drain> in the constructor).
485		893
		894	This method may invoke callbacks (and therefore the handle might be
		895	destroyed after it returns).
		896
486	=cut	897	=cut
487		898
488	sub on_drain {	899	sub on_drain {
489	my ($self, $cb) = @_;	900	my ($self, $cb) = @_;
490		901
…		…
494	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});	905	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
495	}	906	}
496		907
497	=item $handle->push_write ($data)	908	=item $handle->push_write ($data)
498		909
499	Queues the given scalar to be written. You can push as much data as you	910	Queues the given scalar to be written. You can push as much data as
500	want (only limited by the available memory), as C<AnyEvent::Handle>	911	you want (only limited by the available memory and C<wbuf_max>), as
501	buffers it independently of the kernel.	912	C<AnyEvent::Handle> buffers it independently of the kernel.
		913
		914	This method may invoke callbacks (and therefore the handle might be
		915	destroyed after it returns).
502		916
503	=cut	917	=cut
504		918
505	sub _drain_wbuf {	919	sub _drain_wbuf {
506	my ($self) = @_;	920	my ($self) = @_;
…		…
510	Scalar::Util::weaken $self;	924	Scalar::Util::weaken $self;
511		925
512	my $cb = sub {	926	my $cb = sub {
513	my $len = syswrite $self->{fh}, $self->{wbuf};	927	my $len = syswrite $self->{fh}, $self->{wbuf};
514		928
515	if ($len >= 0) {	929	if (defined $len) {
516	substr $self->{wbuf}, 0, $len, "";	930	substr $self->{wbuf}, 0, $len, "";
517		931
518	$self->{_activity} = AnyEvent->now;	932	$self->{_activity} = $self->{_wactivity} = AE::now;
519		933
520	$self->{on_drain}($self)	934	$self->{on_drain}($self)
521	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})	935	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
522	&& $self->{on_drain};	936	&& $self->{on_drain};
523		937
…		…
529		943
530	# try to write data immediately	944	# try to write data immediately
531	$cb->() unless $self->{autocork};	945	$cb->() unless $self->{autocork};
532		946
533	# if still data left in wbuf, we need to poll	947	# if still data left in wbuf, we need to poll
534	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	948	$self->{_ww} = AE::io $self->{fh}, 1, $cb
535	if length $self->{wbuf};	949	if length $self->{wbuf};
		950
		951	if (
		952	defined $self->{wbuf_max}
		953	&& $self->{wbuf_max} < length $self->{wbuf}
		954	) {
		955	$self->_error (Errno::ENOSPC, 1), return;
		956	}
536	};	957	};
537	}	958	}
538		959
539	our %WH;	960	our %WH;
540		961
		962	# deprecated
541	sub register_write_type($$) {	963	sub register_write_type($$) {
542	$WH{$_[0]} = $_[1];	964	$WH{$_[0]} = $_[1];
543	}	965	}
544		966
545	sub push_write {	967	sub push_write {
546	my $self = shift;	968	my $self = shift;
547		969
548	if (@_ > 1) {	970	if (@_ > 1) {
549	my $type = shift;	971	my $type = shift;
550		972
		973	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
551	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	974	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
552	->($self, @_);	975	->($self, @_);
553	}	976	}
554		977
		978	# we downgrade here to avoid hard-to-track-down bugs,
		979	# and diagnose the problem earlier and better.
		980
555	if ($self->{tls}) {	981	if ($self->{tls}) {
556	$self->{_tls_wbuf} .= $_[0];	982	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
557	&_dotls ($self);	983	&_dotls ($self) if $self->{fh};
558	} else {	984	} else {
559	$self->{wbuf} .= $_[0];	985	utf8::downgrade $self->{wbuf} .= $_[0];
560	$self->_drain_wbuf;	986	$self->_drain_wbuf if $self->{fh};
561	}	987	}
562	}	988	}
563		989
564	=item $handle->push_write (type => @args)	990	=item $handle->push_write (type => @args)
565		991
566	Instead of formatting your data yourself, you can also let this module do	992	Instead of formatting your data yourself, you can also let this module
567	the job by specifying a type and type-specific arguments.	993	do the job by specifying a type and type-specific arguments. You
		994	can also specify the (fully qualified) name of a package, in which
		995	case AnyEvent tries to load the package and then expects to find the
		996	C<anyevent_write_type> function inside (see "custom write types", below).
568		997
569	Predefined types are (if you have ideas for additional types, feel free to	998	Predefined types are (if you have ideas for additional types, feel free to
570	drop by and tell us):	999	drop by and tell us):
571		1000
572	=over 4	1001	=over 4
…		…
579	=cut	1008	=cut
580		1009
581	register_write_type netstring => sub {	1010	register_write_type netstring => sub {
582	my ($self, $string) = @_;	1011	my ($self, $string) = @_;
583		1012
584	sprintf "%d:%s,", (length $string), $string	1013	(length $string) . ":$string,"
585	};	1014	};
586		1015
587	=item packstring => $format, $data	1016	=item packstring => $format, $data
588		1017
589	An octet string prefixed with an encoded length. The encoding C<$format>	1018	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
629	Other languages could read single lines terminated by a newline and pass	1058	Other languages could read single lines terminated by a newline and pass
630	this line into their JSON decoder of choice.	1059	this line into their JSON decoder of choice.
631		1060
632	=cut	1061	=cut
633		1062
		1063	sub json_coder() {
		1064	eval { require JSON::XS; JSON::XS->new->utf8 }
		1065	|| do { require JSON; JSON->new->utf8 }
		1066	}
		1067
634	register_write_type json => sub {	1068	register_write_type json => sub {
635	my ($self, $ref) = @_;	1069	my ($self, $ref) = @_;
636		1070
637	require JSON;	1071	my $json = $self->{json} ||= json_coder;
638		1072
639	$self->{json} ? $self->{json}->encode ($ref)	1073	$json->encode ($ref)
640	: JSON::encode_json ($ref)
641	};	1074	};
642		1075
643	=item storable => $reference	1076	=item storable => $reference
644		1077
645	Freezes the given reference using L<Storable> and writes it to the	1078	Freezes the given reference using L<Storable> and writes it to the
…		…
655	pack "w/a*", Storable::nfreeze ($ref)	1088	pack "w/a*", Storable::nfreeze ($ref)
656	};	1089	};
657		1090
658	=back	1091	=back
659		1092
660	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1093	=item $handle->push_shutdown
661		1094
662	This function (not method) lets you add your own types to C<push_write>.	1095	Sometimes you know you want to close the socket after writing your data
		1096	before it was actually written. One way to do that is to replace your
		1097	C<on_drain> handler by a callback that shuts down the socket (and set
		1098	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1099	replaces the C<on_drain> callback with:
		1100
		1101	sub { shutdown $_[0]{fh}, 1 }
		1102
		1103	This simply shuts down the write side and signals an EOF condition to the
		1104	the peer.
		1105
		1106	You can rely on the normal read queue and C<on_eof> handling
		1107	afterwards. This is the cleanest way to close a connection.
		1108
		1109	This method may invoke callbacks (and therefore the handle might be
		1110	destroyed after it returns).
		1111
		1112	=cut
		1113
		1114	sub push_shutdown {
		1115	my ($self) = @_;
		1116
		1117	delete $self->{low_water_mark};
		1118	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1119	}
		1120
		1121	=item custom write types - Package::anyevent_write_type $handle, @args
		1122
		1123	Instead of one of the predefined types, you can also specify the name of
		1124	a package. AnyEvent will try to load the package and then expects to find
		1125	a function named C<anyevent_write_type> inside. If it isn't found, it
		1126	progressively tries to load the parent package until it either finds the
		1127	function (good) or runs out of packages (bad).
		1128
663	Whenever the given C<type> is used, C<push_write> will invoke the code	1129	Whenever the given C<type> is used, C<push_write> will the function with
664	reference with the handle object and the remaining arguments.	1130	the handle object and the remaining arguments.
665		1131
666	The code reference is supposed to return a single octet string that will	1132	The function is supposed to return a single octet string that will be
667	be appended to the write buffer.	1133	appended to the write buffer, so you cna mentally treat this function as a
		1134	"arguments to on-the-wire-format" converter.
668		1135
669	Note that this is a function, and all types registered this way will be	1136	Example: implement a custom write type C<join> that joins the remaining
670	global, so try to use unique names.	1137	arguments using the first one.
		1138
		1139	$handle->push_write (My::Type => " ", 1,2,3);
		1140
		1141	# uses the following package, which can be defined in the "My::Type" or in
		1142	# the "My" modules to be auto-loaded, or just about anywhere when the
		1143	# My::Type::anyevent_write_type is defined before invoking it.
		1144
		1145	package My::Type;
		1146
		1147	sub anyevent_write_type {
		1148	my ($handle, $delim, @args) = @_;
		1149
		1150	join $delim, @args
		1151	}
671		1152
672	=cut	1153	=cut
673		1154
674	#############################################################################	1155	#############################################################################
675		1156
…		…
684	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1165	ways, the "simple" way, using only C<on_read> and the "complex" way, using
685	a queue.	1166	a queue.
686		1167
687	In the simple case, you just install an C<on_read> callback and whenever	1168	In the simple case, you just install an C<on_read> callback and whenever
688	new data arrives, it will be called. You can then remove some data (if	1169	new data arrives, it will be called. You can then remove some data (if
689	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1170	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
690	leave the data there if you want to accumulate more (e.g. when only a	1171	leave the data there if you want to accumulate more (e.g. when only a
691	partial message has been received so far).	1172	partial message has been received so far), or change the read queue with
		1173	e.g. C<push_read>.
692		1174
693	In the more complex case, you want to queue multiple callbacks. In this	1175	In the more complex case, you want to queue multiple callbacks. In this
694	case, AnyEvent::Handle will call the first queued callback each time new	1176	case, AnyEvent::Handle will call the first queued callback each time new
695	data arrives (also the first time it is queued) and removes it when it has	1177	data arrives (also the first time it is queued) and remove it when it has
696	done its job (see C<push_read>, below).	1178	done its job (see C<push_read>, below).
697		1179
698	This way you can, for example, push three line-reads, followed by reading	1180	This way you can, for example, push three line-reads, followed by reading
699	a chunk of data, and AnyEvent::Handle will execute them in order.	1181	a chunk of data, and AnyEvent::Handle will execute them in order.
700		1182
…		…
757	=cut	1239	=cut
758		1240
759	sub _drain_rbuf {	1241	sub _drain_rbuf {
760	my ($self) = @_;	1242	my ($self) = @_;
761		1243
		1244	# avoid recursion
		1245	return if $self->{_skip_drain_rbuf};
762	local $self->{_in_drain} = 1;	1246	local $self->{_skip_drain_rbuf} = 1;
763
764	if (
765	defined $self->{rbuf_max}
766	&& $self->{rbuf_max} < length $self->{rbuf}
767	) {
768	$self->_error (&Errno::ENOSPC, 1), return;
769	}
770		1247
771	while () {	1248	while () {
		1249	# we need to use a separate tls read buffer, as we must not receive data while
		1250	# we are draining the buffer, and this can only happen with TLS.
		1251	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1252	if exists $self->{_tls_rbuf};
		1253
772	my $len = length $self->{rbuf};	1254	my $len = length $self->{rbuf};
773		1255
774	if (my $cb = shift @{ $self->{_queue} }) {	1256	if (my $cb = shift @{ $self->{_queue} }) {
775	unless ($cb->($self)) {	1257	unless ($cb->($self)) {
776	if ($self->{_eof}) {	1258	# no progress can be made
777	# no progress can be made (not enough data and no data forthcoming)	1259	# (not enough data and no data forthcoming)
778	$self->_error (&Errno::EPIPE, 1), return;	1260	$self->_error (Errno::EPIPE, 1), return
779	}	1261	if $self->{_eof};
780		1262
781	unshift @{ $self->{_queue} }, $cb;	1263	unshift @{ $self->{_queue} }, $cb;
782	last;	1264	last;
783	}	1265	}
784	} elsif ($self->{on_read}) {	1266	} elsif ($self->{on_read}) {
…		…
791	&& !@{ $self->{_queue} } # and the queue is still empty	1273	&& !@{ $self->{_queue} } # and the queue is still empty
792	&& $self->{on_read} # but we still have on_read	1274	&& $self->{on_read} # but we still have on_read
793	) {	1275	) {
794	# no further data will arrive	1276	# no further data will arrive
795	# so no progress can be made	1277	# so no progress can be made
796	$self->_error (&Errno::EPIPE, 1), return	1278	$self->_error (Errno::EPIPE, 1), return
797	if $self->{_eof};	1279	if $self->{_eof};
798		1280
799	last; # more data might arrive	1281	last; # more data might arrive
800	}	1282	}
801	} else {	1283	} else {
…		…
804	last;	1286	last;
805	}	1287	}
806	}	1288	}
807		1289
808	if ($self->{_eof}) {	1290	if ($self->{_eof}) {
809	if ($self->{on_eof}) {	1291	$self->{on_eof}
810	$self->{on_eof}($self)	1292	? $self->{on_eof}($self)
811	} else {	1293	: $self->_error (0, 1, "Unexpected end-of-file");
812	$self->_error (0, 1);	1294
813	}	1295	return;
		1296	}
		1297
		1298	if (
		1299	defined $self->{rbuf_max}
		1300	&& $self->{rbuf_max} < length $self->{rbuf}
		1301	) {
		1302	$self->_error (Errno::ENOSPC, 1), return;
814	}	1303	}
815		1304
816	# may need to restart read watcher	1305	# may need to restart read watcher
817	unless ($self->{_rw}) {	1306	unless ($self->{_rw}) {
818	$self->start_read	1307	$self->start_read
…		…
824		1313
825	This replaces the currently set C<on_read> callback, or clears it (when	1314	This replaces the currently set C<on_read> callback, or clears it (when
826	the new callback is C<undef>). See the description of C<on_read> in the	1315	the new callback is C<undef>). See the description of C<on_read> in the
827	constructor.	1316	constructor.
828		1317
		1318	This method may invoke callbacks (and therefore the handle might be
		1319	destroyed after it returns).
		1320
829	=cut	1321	=cut
830		1322
831	sub on_read {	1323	sub on_read {
832	my ($self, $cb) = @_;	1324	my ($self, $cb) = @_;
833		1325
834	$self->{on_read} = $cb;	1326	$self->{on_read} = $cb;
835	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1327	$self->_drain_rbuf if $cb;
836	}	1328	}
837		1329
838	=item $handle->rbuf	1330	=item $handle->rbuf
839		1331
840	Returns the read buffer (as a modifiable lvalue).	1332	Returns the read buffer (as a modifiable lvalue). You can also access the
		1333	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1334	much faster, and no less clean).
841		1335
842	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1336	The only operation allowed on the read buffer (apart from looking at it)
843	you want.	1337	is removing data from its beginning. Otherwise modifying or appending to
		1338	it is not allowed and will lead to hard-to-track-down bugs.
844		1339
845	NOTE: The read buffer should only be used or modified if the C<on_read>,	1340	NOTE: The read buffer should only be used or modified in the C<on_read>
846	C<push_read> or C<unshift_read> methods are used. The other read methods	1341	callback or when C<push_read> or C<unshift_read> are used with a single
847	automatically manage the read buffer.	1342	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1343	will manage the read buffer on their own.
848		1344
849	=cut	1345	=cut
850		1346
851	sub rbuf : lvalue {	1347	sub rbuf : lvalue {
852	$_[0]{rbuf}	1348	$_[0]{rbuf}
…		…
869		1365
870	If enough data was available, then the callback must remove all data it is	1366	If enough data was available, then the callback must remove all data it is
871	interested in (which can be none at all) and return a true value. After returning	1367	interested in (which can be none at all) and return a true value. After returning
872	true, it will be removed from the queue.	1368	true, it will be removed from the queue.
873		1369
		1370	These methods may invoke callbacks (and therefore the handle might be
		1371	destroyed after it returns).
		1372
874	=cut	1373	=cut
875		1374
876	our %RH;	1375	our %RH;
877		1376
878	sub register_read_type($$) {	1377	sub register_read_type($$) {
…		…
884	my $cb = pop;	1383	my $cb = pop;
885		1384
886	if (@_) {	1385	if (@_) {
887	my $type = shift;	1386	my $type = shift;
888		1387
		1388	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
889	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1389	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
890	->($self, $cb, @_);	1390	->($self, $cb, @_);
891	}	1391	}
892		1392
893	push @{ $self->{_queue} }, $cb;	1393	push @{ $self->{_queue} }, $cb;
894	$self->_drain_rbuf unless $self->{_in_drain};	1394	$self->_drain_rbuf;
895	}	1395	}
896		1396
897	sub unshift_read {	1397	sub unshift_read {
898	my $self = shift;	1398	my $self = shift;
899	my $cb = pop;	1399	my $cb = pop;
900		1400
901	if (@_) {	1401	if (@_) {
902	my $type = shift;	1402	my $type = shift;
903		1403
		1404	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
904	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1405	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
905	->($self, $cb, @_);	1406	->($self, $cb, @_);
906	}	1407	}
907		1408
908
909	unshift @{ $self->{_queue} }, $cb;	1409	unshift @{ $self->{_queue} }, $cb;
910	$self->_drain_rbuf unless $self->{_in_drain};	1410	$self->_drain_rbuf;
911	}	1411	}
912		1412
913	=item $handle->push_read (type => @args, $cb)	1413	=item $handle->push_read (type => @args, $cb)
914		1414
915	=item $handle->unshift_read (type => @args, $cb)	1415	=item $handle->unshift_read (type => @args, $cb)
916		1416
917	Instead of providing a callback that parses the data itself you can chose	1417	Instead of providing a callback that parses the data itself you can chose
918	between a number of predefined parsing formats, for chunks of data, lines	1418	between a number of predefined parsing formats, for chunks of data, lines
919	etc.	1419	etc. You can also specify the (fully qualified) name of a package, in
		1420	which case AnyEvent tries to load the package and then expects to find the
		1421	C<anyevent_read_type> function inside (see "custom read types", below).
920		1422
921	Predefined types are (if you have ideas for additional types, feel free to	1423	Predefined types are (if you have ideas for additional types, feel free to
922	drop by and tell us):	1424	drop by and tell us):
923		1425
924	=over 4	1426	=over 4
…		…
930	data.	1432	data.
931		1433
932	Example: read 2 bytes.	1434	Example: read 2 bytes.
933		1435
934	$handle->push_read (chunk => 2, sub {	1436	$handle->push_read (chunk => 2, sub {
935	warn "yay ", unpack "H*", $_[1];	1437	AE::log debug => "yay " . unpack "H*", $_[1];
936	});	1438	});
937		1439
938	=cut	1440	=cut
939		1441
940	register_read_type chunk => sub {	1442	register_read_type chunk => sub {
…		…
1016	the receive buffer when neither C<$accept> nor C<$reject> match,	1518	the receive buffer when neither C<$accept> nor C<$reject> match,
1017	and everything preceding and including the match will be accepted	1519	and everything preceding and including the match will be accepted
1018	unconditionally. This is useful to skip large amounts of data that you	1520	unconditionally. This is useful to skip large amounts of data that you
1019	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1521	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1020	have to start matching from the beginning. This is purely an optimisation	1522	have to start matching from the beginning. This is purely an optimisation
1021	and is usually worth only when you expect more than a few kilobytes.	1523	and is usually worth it only when you expect more than a few kilobytes.
1022		1524
1023	Example: expect a http header, which ends at C<\015\012\015\012>. Since we	1525	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1024	expect the header to be very large (it isn't in practise, but...), we use	1526	expect the header to be very large (it isn't in practice, but...), we use
1025	a skip regex to skip initial portions. The skip regex is tricky in that	1527	a skip regex to skip initial portions. The skip regex is tricky in that
1026	it only accepts something not ending in either \015 or \012, as these are	1528	it only accepts something not ending in either \015 or \012, as these are
1027	required for the accept regex.	1529	required for the accept regex.
1028		1530
1029	$handle->push_read (regex =>	1531	$handle->push_read (regex =>
…		…
1042		1544
1043	sub {	1545	sub {
1044	# accept	1546	# accept
1045	if ($$rbuf =~ $accept) {	1547	if ($$rbuf =~ $accept) {
1046	$data .= substr $$rbuf, 0, $+[0], "";	1548	$data .= substr $$rbuf, 0, $+[0], "";
1047	$cb->($self, $data);	1549	$cb->($_[0], $data);
1048	return 1;	1550	return 1;
1049	}	1551	}
1050		1552
1051	# reject	1553	# reject
1052	if ($reject && $$rbuf =~ $reject) {	1554	if ($reject && $$rbuf =~ $reject) {
1053	$self->_error (&Errno::EBADMSG);	1555	$_[0]->_error (Errno::EBADMSG);
1054	}	1556	}
1055		1557
1056	# skip	1558	# skip
1057	if ($skip && $$rbuf =~ $skip) {	1559	if ($skip && $$rbuf =~ $skip) {
1058	$data .= substr $$rbuf, 0, $+[0], "";	1560	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1074	my ($self, $cb) = @_;	1576	my ($self, $cb) = @_;
1075		1577
1076	sub {	1578	sub {
1077	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1579	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1078	if ($_[0]{rbuf} =~ /[^0-9]/) {	1580	if ($_[0]{rbuf} =~ /[^0-9]/) {
1079	$self->_error (&Errno::EBADMSG);	1581	$_[0]->_error (Errno::EBADMSG);
1080	}	1582	}
1081	return;	1583	return;
1082	}	1584	}
1083		1585
1084	my $len = $1;	1586	my $len = $1;
1085		1587
1086	$self->unshift_read (chunk => $len, sub {	1588	$_[0]->unshift_read (chunk => $len, sub {
1087	my $string = $_[1];	1589	my $string = $_[1];
1088	$_[0]->unshift_read (chunk => 1, sub {	1590	$_[0]->unshift_read (chunk => 1, sub {
1089	if ($_[1] eq ",") {	1591	if ($_[1] eq ",") {
1090	$cb->($_[0], $string);	1592	$cb->($_[0], $string);
1091	} else {	1593	} else {
1092	$self->_error (&Errno::EBADMSG);	1594	$_[0]->_error (Errno::EBADMSG);
1093	}	1595	}
1094	});	1596	});
1095	});	1597	});
1096		1598
1097	1	1599	1
…		…
1103	An octet string prefixed with an encoded length. The encoding C<$format>	1605	An octet string prefixed with an encoded length. The encoding C<$format>
1104	uses the same format as a Perl C<pack> format, but must specify a single	1606	uses the same format as a Perl C<pack> format, but must specify a single
1105	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1607	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1106	optional C<!>, C<< < >> or C<< > >> modifier).	1608	optional C<!>, C<< < >> or C<< > >> modifier).
1107		1609
1108	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.	1610	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1611	EPP uses a prefix of C<N> (4 octtes).
1109		1612
1110	Example: read a block of data prefixed by its length in BER-encoded	1613	Example: read a block of data prefixed by its length in BER-encoded
1111	format (very efficient).	1614	format (very efficient).
1112		1615
1113	$handle->push_read (packstring => "w", sub {	1616	$handle->push_read (packstring => "w", sub {
…		…
1143	}	1646	}
1144	};	1647	};
1145		1648
1146	=item json => $cb->($handle, $hash_or_arrayref)	1649	=item json => $cb->($handle, $hash_or_arrayref)
1147		1650
1148	Reads a JSON object or array, decodes it and passes it to the callback.	1651	Reads a JSON object or array, decodes it and passes it to the
		1652	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1149		1653
1150	If a C<json> object was passed to the constructor, then that will be used	1654	If a C<json> object was passed to the constructor, then that will be used
1151	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1655	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1152		1656
1153	This read type uses the incremental parser available with JSON version	1657	This read type uses the incremental parser available with JSON version
…		…
1162	=cut	1666	=cut
1163		1667
1164	register_read_type json => sub {	1668	register_read_type json => sub {
1165	my ($self, $cb) = @_;	1669	my ($self, $cb) = @_;
1166		1670
1167	require JSON;	1671	my $json = $self->{json} ||= json_coder;
1168		1672
1169	my $data;	1673	my $data;
1170	my $rbuf = \$self->{rbuf};	1674	my $rbuf = \$self->{rbuf};
1171		1675
1172	my $json = $self->{json} ||= JSON->new->utf8;
1173
1174	sub {	1676	sub {
1175	my $ref = $json->incr_parse ($self->{rbuf});	1677	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1176		1678
1177	if ($ref) {	1679	if ($ref) {
1178	$self->{rbuf} = $json->incr_text;	1680	$_[0]{rbuf} = $json->incr_text;
1179	$json->incr_text = "";	1681	$json->incr_text = "";
1180	$cb->($self, $ref);	1682	$cb->($_[0], $ref);
1181		1683
1182	1	1684	1
		1685	} elsif ($@) {
		1686	# error case
		1687	$json->incr_skip;
		1688
		1689	$_[0]{rbuf} = $json->incr_text;
		1690	$json->incr_text = "";
		1691
		1692	$_[0]->_error (Errno::EBADMSG);
		1693
		1694	()
1183	} else {	1695	} else {
1184	$self->{rbuf} = "";	1696	$_[0]{rbuf} = "";
		1697
1185	()	1698	()
1186	}	1699	}
1187	}	1700	}
1188	};	1701	};
1189		1702
…		…
1221	# read remaining chunk	1734	# read remaining chunk
1222	$_[0]->unshift_read (chunk => $len, sub {	1735	$_[0]->unshift_read (chunk => $len, sub {
1223	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1736	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1224	$cb->($_[0], $ref);	1737	$cb->($_[0], $ref);
1225	} else {	1738	} else {
1226	$self->_error (&Errno::EBADMSG);	1739	$_[0]->_error (Errno::EBADMSG);
1227	}	1740	}
1228	});	1741	});
1229	}	1742	}
1230		1743
1231	1	1744	1
1232	}	1745	}
1233	};	1746	};
1234		1747
1235	=back	1748	=back
1236		1749
1237	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1750	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1238		1751
1239	This function (not method) lets you add your own types to C<push_read>.	1752	Instead of one of the predefined types, you can also specify the name
		1753	of a package. AnyEvent will try to load the package and then expects to
		1754	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1755	progressively tries to load the parent package until it either finds the
		1756	function (good) or runs out of packages (bad).
1240		1757
1241	Whenever the given C<type> is used, C<push_read> will invoke the code	1758	Whenever this type is used, C<push_read> will invoke the function with the
1242	reference with the handle object, the callback and the remaining	1759	handle object, the original callback and the remaining arguments.
1243	arguments.
1244		1760
1245	The code reference is supposed to return a callback (usually a closure)	1761	The function is supposed to return a callback (usually a closure) that
1246	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1762	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1763	mentally treat the function as a "configurable read type to read callback"
		1764	converter.
1247		1765
1248	It should invoke the passed callback when it is done reading (remember to	1766	It should invoke the original callback when it is done reading (remember
1249	pass C<$handle> as first argument as all other callbacks do that).	1767	to pass C<$handle> as first argument as all other callbacks do that,
		1768	although there is no strict requirement on this).
1250		1769
1251	Note that this is a function, and all types registered this way will be
1252	global, so try to use unique names.
1253
1254	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1770	For examples, see the source of this module (F<perldoc -m
1255	search for C<register_read_type>)).	1771	AnyEvent::Handle>, search for C<register_read_type>)).
1256		1772
1257	=item $handle->stop_read	1773	=item $handle->stop_read
1258		1774
1259	=item $handle->start_read	1775	=item $handle->start_read
1260		1776
…		…
1266	Note that AnyEvent::Handle will automatically C<start_read> for you when	1782	Note that AnyEvent::Handle will automatically C<start_read> for you when
1267	you change the C<on_read> callback or push/unshift a read callback, and it	1783	you change the C<on_read> callback or push/unshift a read callback, and it
1268	will automatically C<stop_read> for you when neither C<on_read> is set nor	1784	will automatically C<stop_read> for you when neither C<on_read> is set nor
1269	there are any read requests in the queue.	1785	there are any read requests in the queue.
1270		1786
1271	These methods will have no effect when in TLS mode (as TLS doesn't support	1787	In older versions of this module (<= 5.3), these methods had no effect,
1272	half-duplex connections).	1788	as TLS does not support half-duplex connections. In current versions they
		1789	work as expected, as this behaviour is required to avoid certain resource
		1790	attacks, where the program would be forced to read (and buffer) arbitrary
		1791	amounts of data before being able to send some data. The drawback is that
		1792	some readings of the the SSL/TLS specifications basically require this
		1793	attack to be working, as SSL/TLS implementations might stall sending data
		1794	during a rehandshake.
		1795
		1796	As a guideline, during the initial handshake, you should not stop reading,
		1797	and as a client, it might cause problems, depending on your applciation.
1273		1798
1274	=cut	1799	=cut
1275		1800
1276	sub stop_read {	1801	sub stop_read {
1277	my ($self) = @_;	1802	my ($self) = @_;
1278		1803
1279	delete $self->{_rw} unless $self->{tls};	1804	delete $self->{_rw};
1280	}	1805	}
1281		1806
1282	sub start_read {	1807	sub start_read {
1283	my ($self) = @_;	1808	my ($self) = @_;
1284		1809
1285	unless ($self->{_rw} || $self->{_eof}) {	1810	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1286	Scalar::Util::weaken $self;	1811	Scalar::Util::weaken $self;
1287		1812
1288	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1813	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1289	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});	1814	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1290	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1815	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1291		1816
1292	if ($len > 0) {	1817	if ($len > 0) {
1293	$self->{_activity} = AnyEvent->now;	1818	$self->{_activity} = $self->{_ractivity} = AE::now;
1294		1819
1295	if ($self->{tls}) {	1820	if ($self->{tls}) {
1296	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);	1821	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1822
1297	&_dotls ($self);	1823	&_dotls ($self);
1298	} else {	1824	} else {
1299	$self->_drain_rbuf unless $self->{_in_drain};	1825	$self->_drain_rbuf;
		1826	}
		1827
		1828	if ($len == $self->{read_size}) {
		1829	$self->{read_size} *= 2;
		1830	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1831	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1300	}	1832	}
1301		1833
1302	} elsif (defined $len) {	1834	} elsif (defined $len) {
1303	delete $self->{_rw};	1835	delete $self->{_rw};
1304	$self->{_eof} = 1;	1836	$self->{_eof} = 1;
1305	$self->_drain_rbuf unless $self->{_in_drain};	1837	$self->_drain_rbuf;
1306		1838
1307	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1839	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1308	return $self->_error ($!, 1);	1840	return $self->_error ($!, 1);
1309	}	1841	}
1310	});	1842	};
1311	}	1843	}
1312	}	1844	}
1313		1845
		1846	our $ERROR_SYSCALL;
		1847	our $ERROR_WANT_READ;
		1848
		1849	sub _tls_error {
		1850	my ($self, $err) = @_;
		1851
		1852	return $self->_error ($!, 1)
		1853	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1854
		1855	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1856
		1857	# reduce error string to look less scary
		1858	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1859
		1860	if ($self->{_on_starttls}) {
		1861	(delete $self->{_on_starttls})->($self, undef, $err);
		1862	&_freetls;
		1863	} else {
		1864	&_freetls;
		1865	$self->_error (Errno::EPROTO, 1, $err);
		1866	}
		1867	}
		1868
		1869	# poll the write BIO and send the data if applicable
		1870	# also decode read data if possible
		1871	# this is basiclaly our TLS state machine
		1872	# more efficient implementations are possible with openssl,
		1873	# but not with the buggy and incomplete Net::SSLeay.
1314	sub _dotls {	1874	sub _dotls {
1315	my ($self) = @_;	1875	my ($self) = @_;
1316		1876
1317	my $buf;	1877	my $tmp;
1318		1878
1319	if (length $self->{_tls_wbuf}) {	1879	if (length $self->{_tls_wbuf}) {
1320	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1880	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1321	substr $self->{_tls_wbuf}, 0, $len, "";	1881	substr $self->{_tls_wbuf}, 0, $tmp, "";
1322	}	1882	}
1323	}
1324		1883
		1884	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1885	return $self->_tls_error ($tmp)
		1886	if $tmp != $ERROR_WANT_READ
		1887	&& ($tmp != $ERROR_SYSCALL || $!);
		1888	}
		1889
1325	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1890	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1326	unless (length $buf) {	1891	unless (length $tmp) {
1327	# let's treat SSL-eof as we treat normal EOF	1892	$self->{_on_starttls}
1328	delete $self->{_rw};	1893	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1329	$self->{_eof} = 1;
1330	&_freetls;	1894	&_freetls;
		1895
		1896	if ($self->{on_stoptls}) {
		1897	$self->{on_stoptls}($self);
		1898	return;
		1899	} else {
		1900	# let's treat SSL-eof as we treat normal EOF
		1901	delete $self->{_rw};
		1902	$self->{_eof} = 1;
		1903	}
1331	}	1904	}
1332		1905
1333	$self->{rbuf} .= $buf;	1906	$self->{_tls_rbuf} .= $tmp;
1334	$self->_drain_rbuf unless $self->{_in_drain};	1907	$self->_drain_rbuf;
1335	$self->{tls} or return; # tls session might have gone away in callback	1908	$self->{tls} or return; # tls session might have gone away in callback
1336	}	1909	}
1337		1910
1338	my $err = Net::SSLeay::get_error ($self->{tls}, -1);	1911	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1339
1340	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1341	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1342	return $self->_error ($!, 1);	1912	return $self->_tls_error ($tmp)
1343	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {	1913	if $tmp != $ERROR_WANT_READ
1344	return $self->_error (&Errno::EIO, 1);	1914	&& ($tmp != $ERROR_SYSCALL || $!);
1345	}
1346		1915
1347	# all others are fine for our purposes
1348	}
1349
1350	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1916	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1351	$self->{wbuf} .= $buf;	1917	$self->{wbuf} .= $tmp;
1352	$self->_drain_wbuf;	1918	$self->_drain_wbuf;
		1919	$self->{tls} or return; # tls session might have gone away in callback
1353	}	1920	}
		1921
		1922	$self->{_on_starttls}
		1923	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1924	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1354	}	1925	}
1355		1926
1356	=item $handle->starttls ($tls[, $tls_ctx])	1927	=item $handle->starttls ($tls[, $tls_ctx])
1357		1928
1358	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1929	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1359	object is created, you can also do that at a later time by calling	1930	object is created, you can also do that at a later time by calling
1360	C<starttls>.	1931	C<starttls>.
1361		1932
		1933	Starting TLS is currently an asynchronous operation - when you push some
		1934	write data and then call C<< ->starttls >> then TLS negotiation will start
		1935	immediately, after which the queued write data is then sent.
		1936
1362	The first argument is the same as the C<tls> constructor argument (either	1937	The first argument is the same as the C<tls> constructor argument (either
1363	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1938	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1364		1939
1365	The second argument is the optional C<Net::SSLeay::CTX> object that is	1940	The second argument is the optional C<AnyEvent::TLS> object that is used
1366	used when AnyEvent::Handle has to create its own TLS connection object.	1941	when AnyEvent::Handle has to create its own TLS connection object, or
		1942	a hash reference with C<< key => value >> pairs that will be used to
		1943	construct a new context.
1367		1944
1368	The TLS connection object will end up in C<< $handle->{tls} >> after this	1945	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1369	call and can be used or changed to your liking. Note that the handshake	1946	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1370	might have already started when this function returns.	1947	changed to your liking. Note that the handshake might have already started
		1948	when this function returns.
1371		1949
1372	If it an error to start a TLS handshake more than once per	1950	Due to bugs in OpenSSL, it might or might not be possible to do multiple
1373	AnyEvent::Handle object (this is due to bugs in OpenSSL).	1951	handshakes on the same stream. It is best to not attempt to use the
		1952	stream after stopping TLS.
1374		1953
		1954	This method may invoke callbacks (and therefore the handle might be
		1955	destroyed after it returns).
		1956
1375	=cut	1957	=cut
		1958
		1959	our %TLS_CACHE; #TODO not yet documented, should we?
1376		1960
1377	sub starttls {	1961	sub starttls {
1378	my ($self, $ssl, $ctx) = @_;	1962	my ($self, $tls, $ctx) = @_;
1379		1963
1380	Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"	1964	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1381	if $self->{tls};	1965	if $self->{tls};
		1966
		1967	$self->{tls} = $tls;
		1968	$self->{tls_ctx} = $ctx if @_ > 2;
		1969
		1970	return unless $self->{fh};
		1971
		1972	require Net::SSLeay;
		1973
		1974	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1975	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1976
		1977	$tls = delete $self->{tls};
		1978	$ctx = $self->{tls_ctx};
		1979
		1980	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1981
		1982	if ("HASH" eq ref $ctx) {
		1983	require AnyEvent::TLS;
		1984
		1985	if ($ctx->{cache}) {
		1986	my $key = $ctx+0;
		1987	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1988	} else {
		1989	$ctx = new AnyEvent::TLS %$ctx;
		1990	}
		1991	}
1382		1992
1383	if ($ssl eq "accept") {	1993	$self->{tls_ctx} = $ctx || TLS_CTX ();
1384	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1994	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1385	Net::SSLeay::set_accept_state ($ssl);
1386	} elsif ($ssl eq "connect") {
1387	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1388	Net::SSLeay::set_connect_state ($ssl);
1389	}
1390
1391	$self->{tls} = $ssl;
1392		1995
1393	# basically, this is deep magic (because SSL_read should have the same issues)	1996	# basically, this is deep magic (because SSL_read should have the same issues)
1394	# but the openssl maintainers basically said: "trust us, it just works".	1997	# but the openssl maintainers basically said: "trust us, it just works".
1395	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1998	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1396	# and mismaintained ssleay-module doesn't even offer them).	1999	# and mismaintained ssleay-module doesn't even offer them).
…		…
1400	#	2003	#
1401	# note that we do not try to keep the length constant between writes as we are required to do.	2004	# note that we do not try to keep the length constant between writes as we are required to do.
1402	# we assume that most (but not all) of this insanity only applies to non-blocking cases,	2005	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
1403	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to	2006	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1404	# have identity issues in that area.	2007	# have identity issues in that area.
1405	Net::SSLeay::CTX_set_mode ($self->{tls},	2008	# Net::SSLeay::CTX_set_mode ($ssl,
1406	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2009	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1407	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2010	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2011	Net::SSLeay::CTX_set_mode ($tls, 1|2);
1408		2012
1409	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1410	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2014	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1411		2015
		2016	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2017	$self->{rbuf} = "";
		2018
1412	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2019	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		2020
		2021	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		2022	if $self->{on_starttls};
1413		2023
1414	&_dotls; # need to trigger the initial handshake	2024	&_dotls; # need to trigger the initial handshake
1415	$self->start_read; # make sure we actually do read	2025	$self->start_read; # make sure we actually do read
1416	}	2026	}
1417		2027
1418	=item $handle->stoptls	2028	=item $handle->stoptls
1419		2029
1420	Shuts down the SSL connection - this makes a proper EOF handshake by	2030	Shuts down the SSL connection - this makes a proper EOF handshake by
1421	sending a close notify to the other side, but since OpenSSL doesn't	2031	sending a close notify to the other side, but since OpenSSL doesn't
1422	support non-blocking shut downs, it is not possible to re-use the stream	2032	support non-blocking shut downs, it is not guaranteed that you can re-use
1423	afterwards.	2033	the stream afterwards.
		2034
		2035	This method may invoke callbacks (and therefore the handle might be
		2036	destroyed after it returns).
1424		2037
1425	=cut	2038	=cut
1426		2039
1427	sub stoptls {	2040	sub stoptls {
1428	my ($self) = @_;	2041	my ($self) = @_;
1429		2042
1430	if ($self->{tls}) {	2043	if ($self->{tls} && $self->{fh}) {
1431	Net::SSLeay::shutdown $self->{tls};	2044	Net::SSLeay::shutdown ($self->{tls});
1432		2045
1433	&_dotls;	2046	&_dotls;
1434		2047
1435	# we don't give a shit. no, we do, but we can't. no...	2048	# # we don't give a shit. no, we do, but we can't. no...#d#
1436	# we, we... have to use openssl :/	2049	# # we, we... have to use openssl :/#d#
1437	&_freetls;	2050	# &_freetls;#d#
1438	}	2051	}
1439	}	2052	}
1440		2053
1441	sub _freetls {	2054	sub _freetls {
1442	my ($self) = @_;	2055	my ($self) = @_;
1443		2056
1444	return unless $self->{tls};	2057	return unless $self->{tls};
1445		2058
1446	Net::SSLeay::free (delete $self->{tls});	2059	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2060	if $self->{tls} > 0;
1447		2061
1448	delete @$self{qw(_rbio _wbio _tls_wbuf)};	2062	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1449	}	2063	}
		2064
		2065	=item $handle->resettls
		2066
		2067	This rarely-used method simply resets and TLS state on the handle, usually
		2068	causing data loss.
		2069
		2070	One case where it may be useful is when you want to skip over the data in
		2071	the stream but you are not interested in interpreting it, so data loss is
		2072	no concern.
		2073
		2074	=cut
		2075
		2076	*resettls = \&_freetls;
1450		2077
1451	sub DESTROY {	2078	sub DESTROY {
1452	my $self = shift;	2079	my ($self) = @_;
1453		2080
1454	&_freetls;	2081	&_freetls;
1455		2082
1456	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2083	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1457		2084
1458	if ($linger && length $self->{wbuf}) {	2085	if ($linger && length $self->{wbuf} && $self->{fh}) {
1459	my $fh = delete $self->{fh};	2086	my $fh = delete $self->{fh};
1460	my $wbuf = delete $self->{wbuf};	2087	my $wbuf = delete $self->{wbuf};
1461		2088
1462	my @linger;	2089	my @linger;
1463		2090
1464	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2091	push @linger, AE::io $fh, 1, sub {
1465	my $len = syswrite $fh, $wbuf, length $wbuf;	2092	my $len = syswrite $fh, $wbuf, length $wbuf;
1466		2093
1467	if ($len > 0) {	2094	if ($len > 0) {
1468	substr $wbuf, 0, $len, "";	2095	substr $wbuf, 0, $len, "";
1469	} else {	2096	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1470	@linger = (); # end	2097	@linger = (); # end
1471	}	2098	}
		2099	};
		2100	push @linger, AE::timer $linger, 0, sub {
		2101	@linger = ();
		2102	};
		2103	}
		2104	}
		2105
		2106	=item $handle->destroy
		2107
		2108	Shuts down the handle object as much as possible - this call ensures that
		2109	no further callbacks will be invoked and as many resources as possible
		2110	will be freed. Any method you will call on the handle object after
		2111	destroying it in this way will be silently ignored (and it will return the
		2112	empty list).
		2113
		2114	Normally, you can just "forget" any references to an AnyEvent::Handle
		2115	object and it will simply shut down. This works in fatal error and EOF
		2116	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2117	callback, so when you want to destroy the AnyEvent::Handle object from
		2118	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2119	that case.
		2120
		2121	Destroying the handle object in this way has the advantage that callbacks
		2122	will be removed as well, so if those are the only reference holders (as
		2123	is common), then one doesn't need to do anything special to break any
		2124	reference cycles.
		2125
		2126	The handle might still linger in the background and write out remaining
		2127	data, as specified by the C<linger> option, however.
		2128
		2129	=cut
		2130
		2131	sub destroy {
		2132	my ($self) = @_;
		2133
		2134	$self->DESTROY;
		2135	%$self = ();
		2136	bless $self, "AnyEvent::Handle::destroyed";
		2137	}
		2138
		2139	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2140	#nop
		2141	}
		2142
		2143	=item $handle->destroyed
		2144
		2145	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2146	->destroy >>, true otherwise.
		2147
		2148	Can be useful to decide whether the handle is still valid after some
		2149	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2150	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2151	can destroy the handle, so work can be avoided by checking sometimes:
		2152
		2153	$hdl->starttls ("accept");
		2154	return if $hdl->destroyed;
		2155	$hdl->push_write (...
		2156
		2157	Note that the call to C<push_write> will silently be ignored if the handle
		2158	has been destroyed, so often you can just ignore the possibility of the
		2159	handle being destroyed.
		2160
		2161	=cut
		2162
		2163	sub destroyed { 0 }
		2164	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2165
		2166	=item AnyEvent::Handle::TLS_CTX
		2167
		2168	This function creates and returns the AnyEvent::TLS object used by default
		2169	for TLS mode.
		2170
		2171	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2172
		2173	=cut
		2174
		2175	our $TLS_CTX;
		2176
		2177	sub TLS_CTX() {
		2178	$TLS_CTX ||= do {
		2179	require AnyEvent::TLS;
		2180
		2181	new AnyEvent::TLS
		2182	}
		2183	}
		2184
		2185	=back
		2186
		2187
		2188	=head1 NONFREQUENTLY ASKED QUESTIONS
		2189
		2190	=over 4
		2191
		2192	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2193	still get further invocations!
		2194
		2195	That's because AnyEvent::Handle keeps a reference to itself when handling
		2196	read or write callbacks.
		2197
		2198	It is only safe to "forget" the reference inside EOF or error callbacks,
		2199	from within all other callbacks, you need to explicitly call the C<<
		2200	->destroy >> method.
		2201
		2202	=item Why is my C<on_eof> callback never called?
		2203
		2204	Probably because your C<on_error> callback is being called instead: When
		2205	you have outstanding requests in your read queue, then an EOF is
		2206	considered an error as you clearly expected some data.
		2207
		2208	To avoid this, make sure you have an empty read queue whenever your handle
		2209	is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
		2210	an C<on_read> handler that simply pushes the first read requests in the
		2211	queue.
		2212
		2213	See also the next question, which explains this in a bit more detail.
		2214
		2215	=item How can I serve requests in a loop?
		2216
		2217	Most protocols consist of some setup phase (authentication for example)
		2218	followed by a request handling phase, where the server waits for requests
		2219	and handles them, in a loop.
		2220
		2221	There are two important variants: The first (traditional, better) variant
		2222	handles requests until the server gets some QUIT command, causing it to
		2223	close the connection first (highly desirable for a busy TCP server). A
		2224	client dropping the connection is an error, which means this variant can
		2225	detect an unexpected detection close.
		2226
		2227	To handle this case, always make sure you have a on-empty read queue, by
		2228	pushing the "read request start" handler on it:
		2229
		2230	# we assume a request starts with a single line
		2231	my @start_request; @start_request = (line => sub {
		2232	my ($hdl, $line) = @_;
		2233
		2234	... handle request
		2235
		2236	# push next request read, possibly from a nested callback
		2237	$hdl->push_read (@start_request);
		2238	});
		2239
		2240	# auth done, now go into request handling loop
		2241	# now push the first @start_request
		2242	$hdl->push_read (@start_request);
		2243
		2244	By always having an outstanding C<push_read>, the handle always expects
		2245	some data and raises the C<EPIPE> error when the connction is dropped
		2246	unexpectedly.
		2247
		2248	The second variant is a protocol where the client can drop the connection
		2249	at any time. For TCP, this means that the server machine may run out of
		2250	sockets easier, and in general, it means you cnanot distinguish a protocl
		2251	failure/client crash from a normal connection close. Nevertheless, these
		2252	kinds of protocols are common (and sometimes even the best solution to the
		2253	problem).
		2254
		2255	Having an outstanding read request at all times is possible if you ignore
		2256	C<EPIPE> errors, but this doesn't help with when the client drops the
		2257	connection during a request, which would still be an error.
		2258
		2259	A better solution is to push the initial request read in an C<on_read>
		2260	callback. This avoids an error, as when the server doesn't expect data
		2261	(i.e. is idly waiting for the next request, an EOF will not raise an
		2262	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2263	and simpler:
		2264
		2265	# auth done, now go into request handling loop
		2266	$hdl->on_read (sub {
		2267	my ($hdl) = @_;
		2268
		2269	# called each time we receive data but the read queue is empty
		2270	# simply start read the request
		2271
		2272	$hdl->push_read (line => sub {
		2273	my ($hdl, $line) = @_;
		2274
		2275	... handle request
		2276
		2277	# do nothing special when the request has been handled, just
		2278	# let the request queue go empty.
1472	});	2279	});
1473	push @linger, AnyEvent->timer (after => $linger, cb => sub {
1474	@linger = ();
1475	});	2280	});
		2281
		2282	=item I get different callback invocations in TLS mode/Why can't I pause
		2283	reading?
		2284
		2285	Unlike, say, TCP, TLS connections do not consist of two independent
		2286	communication channels, one for each direction. Or put differently, the
		2287	read and write directions are not independent of each other: you cannot
		2288	write data unless you are also prepared to read, and vice versa.
		2289
		2290	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2291	callback invocations when you are not expecting any read data - the reason
		2292	is that AnyEvent::Handle always reads in TLS mode.
		2293
		2294	During the connection, you have to make sure that you always have a
		2295	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2296	connection (or when you no longer want to use it) you can call the
		2297	C<destroy> method.
		2298
		2299	=item How do I read data until the other side closes the connection?
		2300
		2301	If you just want to read your data into a perl scalar, the easiest way
		2302	to achieve this is by setting an C<on_read> callback that does nothing,
		2303	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2304	will be in C<$_[0]{rbuf}>:
		2305
		2306	$handle->on_read (sub { });
		2307	$handle->on_eof (undef);
		2308	$handle->on_error (sub {
		2309	my $data = delete $_[0]{rbuf};
		2310	});
		2311
		2312	Note that this example removes the C<rbuf> member from the handle object,
		2313	which is not normally allowed by the API. It is expressly permitted in
		2314	this case only, as the handle object needs to be destroyed afterwards.
		2315
		2316	The reason to use C<on_error> is that TCP connections, due to latencies
		2317	and packets loss, might get closed quite violently with an error, when in
		2318	fact all data has been received.
		2319
		2320	It is usually better to use acknowledgements when transferring data,
		2321	to make sure the other side hasn't just died and you got the data
		2322	intact. This is also one reason why so many internet protocols have an
		2323	explicit QUIT command.
		2324
		2325	=item I don't want to destroy the handle too early - how do I wait until
		2326	all data has been written?
		2327
		2328	After writing your last bits of data, set the C<on_drain> callback
		2329	and destroy the handle in there - with the default setting of
		2330	C<low_water_mark> this will be called precisely when all data has been
		2331	written to the socket:
		2332
		2333	$handle->push_write (...);
		2334	$handle->on_drain (sub {
		2335	AE::log debug => "all data submitted to the kernel\n";
		2336	undef $handle;
		2337	});
		2338
		2339	If you just want to queue some data and then signal EOF to the other side,
		2340	consider using C<< ->push_shutdown >> instead.
		2341
		2342	=item I want to contact a TLS/SSL server, I don't care about security.
		2343
		2344	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2345	connect to it and then create the AnyEvent::Handle with the C<tls>
		2346	parameter:
		2347
		2348	tcp_connect $host, $port, sub {
		2349	my ($fh) = @_;
		2350
		2351	my $handle = new AnyEvent::Handle
		2352	fh => $fh,
		2353	tls => "connect",
		2354	on_error => sub { ... };
		2355
		2356	$handle->push_write (...);
1476	}	2357	};
1477	}
1478		2358
1479	=item AnyEvent::Handle::TLS_CTX	2359	=item I want to contact a TLS/SSL server, I do care about security.
1480		2360
1481	This function creates and returns the Net::SSLeay::CTX object used by	2361	Then you should additionally enable certificate verification, including
1482	default for TLS mode.	2362	peername verification, if the protocol you use supports it (see
		2363	L<AnyEvent::TLS>, C<verify_peername>).
1483		2364
1484	The context is created like this:	2365	E.g. for HTTPS:
1485		2366
1486	Net::SSLeay::load_error_strings;	2367	tcp_connect $host, $port, sub {
1487	Net::SSLeay::SSLeay_add_ssl_algorithms;	2368	my ($fh) = @_;
1488	Net::SSLeay::randomize;
1489		2369
1490	my $CTX = Net::SSLeay::CTX_new;	2370	my $handle = new AnyEvent::Handle
		2371	fh => $fh,
		2372	peername => $host,
		2373	tls => "connect",
		2374	tls_ctx => { verify => 1, verify_peername => "https" },
		2375	...
1491		2376
1492	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL	2377	Note that you must specify the hostname you connected to (or whatever
		2378	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2379	peername verification will be done.
1493		2380
1494	=cut	2381	The above will use the system-dependent default set of trusted CA
		2382	certificates. If you want to check against a specific CA, add the
		2383	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1495		2384
1496	our $TLS_CTX;	2385	tls_ctx => {
		2386	verify => 1,
		2387	verify_peername => "https",
		2388	ca_file => "my-ca-cert.pem",
		2389	},
1497		2390
1498	sub TLS_CTX() {	2391	=item I want to create a TLS/SSL server, how do I do that?
1499	$TLS_CTX || do {
1500	require Net::SSLeay;
1501		2392
1502	Net::SSLeay::load_error_strings ();	2393	Well, you first need to get a server certificate and key. You have
1503	Net::SSLeay::SSLeay_add_ssl_algorithms ();	2394	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1504	Net::SSLeay::randomize ();	2395	self-signed certificate (cheap. check the search engine of your choice,
		2396	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2397	nice program for that purpose).
1505		2398
1506	$TLS_CTX = Net::SSLeay::CTX_new ();	2399	Then create a file with your private key (in PEM format, see
		2400	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2401	file should then look like this:
1507		2402
1508	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());	2403	-----BEGIN RSA PRIVATE KEY-----
		2404	...header data
		2405	... lots of base64'y-stuff
		2406	-----END RSA PRIVATE KEY-----
1509		2407
1510	$TLS_CTX	2408	-----BEGIN CERTIFICATE-----
1511	}	2409	... lots of base64'y-stuff
1512	}	2410	-----END CERTIFICATE-----
		2411
		2412	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2413	specify this file as C<cert_file>:
		2414
		2415	tcp_server undef, $port, sub {
		2416	my ($fh) = @_;
		2417
		2418	my $handle = new AnyEvent::Handle
		2419	fh => $fh,
		2420	tls => "accept",
		2421	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2422	...
		2423
		2424	When you have intermediate CA certificates that your clients might not
		2425	know about, just append them to the C<cert_file>.
1513		2426
1514	=back	2427	=back
		2428
1515		2429
1516	=head1 SUBCLASSING AnyEvent::Handle	2430	=head1 SUBCLASSING AnyEvent::Handle
1517		2431
1518	In many cases, you might want to subclass AnyEvent::Handle.	2432	In many cases, you might want to subclass AnyEvent::Handle.
1519		2433
…		…
1536		2450
1537	=item * all members not documented here and not prefixed with an underscore	2451	=item * all members not documented here and not prefixed with an underscore
1538	are free to use in subclasses.	2452	are free to use in subclasses.
1539		2453
1540	Of course, new versions of AnyEvent::Handle may introduce more "public"	2454	Of course, new versions of AnyEvent::Handle may introduce more "public"
1541	member variables, but thats just life, at least it is documented.	2455	member variables, but that's just life. At least it is documented.
1542		2456
1543	=back	2457	=back
1544		2458
1545	=head1 AUTHOR	2459	=head1 AUTHOR
1546		2460

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