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Revision 1.215 by root, Sun Jan 23 10:44:48 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 = 4.232;
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $handle =	12	my $hdl; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
32	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
33	},	16	warn "got error $msg\n";
		17	$hdl->destroy;
		18	$cv->send;
34	);	19	};
35		20
36	# send some request line	21	# send some request line
37	$handle->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
38		23
39	# read the response line	24	# read the response line
40	$handle->push_read (line => sub {	25	$hdl->push_read (line => sub {
41	my ($handle, $line) = @_;	26	my ($hdl, $line) = @_;
42	warn "read line <$line>\n";	27	warn "got line <$line>\n";
43	$cv->send;	28	$cv->send;
44	});	29	});
45		30
46	$cv->recv;	31	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	This module is a helper module to make it easier to do event-based I/O on	35	This is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
54	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
55	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
56	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
57		47
58	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
59	argument.	49	argument.
60		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
61	=head1 METHODS	82	=head1 METHODS
62		83
63	=over 4	84	=over 4
64		85
65	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66		87
67	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
68		89
69	=over 4	90	=over 4
70		91
71	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72		93
73	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
74
75	NOTE: The filehandle will be set to non-blocking mode (using	95	NOTE: The filehandle will be set to non-blocking mode (using
76	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
77	that mode.	97	that mode.
78		98
		99	=item connect => [$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
79	=item on_eof => $cb->($handle)	116	=item on_prepare => $cb->($handle)
80		117
81	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
82	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
83	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).
84		123
85	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
86	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
87	callback and continue writing data, as only the read part has been shut	126	default timeout is to be used).
88	down.
89		127
90	While not mandatory, it is I<highly> recommended to set an eof callback,	128	=item on_connect => $cb->($handle, $host, $port, $retry->())
91	otherwise you might end up with a closed socket while you are still
92	waiting for data.
93		129
94	If an EOF condition has been detected but no C<on_eof> callback has been	130	This callback is called when a connection has been successfully established.
95	set, then a fatal error will be raised with C<$!> set to <0>.
96		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
97	=item on_error => $cb->($handle, $fatal)	154	=item on_error => $cb->($handle, $fatal, $message)
98		155
99	This is the error callback, which is called when, well, some error	156	This is the error callback, which is called when, well, some error
100	occured, such as not being able to resolve the hostname, failure to	157	occured, such as not being able to resolve the hostname, failure to
101	connect or a read error.	158	connect, or a read error.
102		159
103	Some errors are fatal (which is indicated by C<$fatal> being true). On	160	Some errors are fatal (which is indicated by C<$fatal> being true). On
104	fatal errors the handle object will be shut down and will not be usable	161	fatal errors the handle object will be destroyed (by a call to C<< ->
105	(but you are free to look at the current C< ->rbuf >). Examples of fatal	162	destroy >>) after invoking the error callback (which means you are free to
106	errors are an EOF condition with active (but unsatisifable) read watchers	163	examine the handle object). Examples of fatal errors are an EOF condition
107	(C<EPIPE>) or I/O errors.	164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
108		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
109	Non-fatal errors can be retried by simply returning, but it is recommended	173	Non-fatal errors can be retried by returning, but it is recommended
110	to simply ignore this parameter and instead abondon the handle object	174	to simply ignore this parameter and instead abondon the handle object
111	when this callback is invoked. Examples of non-fatal errors are timeouts	175	when this callback is invoked. Examples of non-fatal errors are timeouts
112	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).	176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
113		177
114	On callback entrance, the value of C<$!> contains the operating system	178	On entry to the callback, the value of C<$!> contains the operating
115	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>).
116		181
117	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
118	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
119	C<croak>.	184	C<croak>.
120		185
121	=item on_read => $cb->($handle)	186	=item on_read => $cb->($handle)
122		187
123	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
124	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
125	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
126	read buffer).	191	read buffer).
127		192
128	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 >>
129	method or access the C<$handle->{rbuf}> member directly.	194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
130		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
131	When an EOF condition is detected then AnyEvent::Handle will first try to	201	When an EOF condition is detected, AnyEvent::Handle will first try to
132	feed all the remaining data to the queued callbacks and C<on_read> before	202	feed all the remaining data to the queued callbacks and C<on_read> before
133	calling the C<on_eof> callback. If no progress can be made, then a fatal	203	calling the C<on_eof> callback. If no progress can be made, then a fatal
134	error will be raised (with C<$!> set to C<EPIPE>).	204	error will be raised (with C<$!> set to C<EPIPE>).
135		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
136	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
137		228
138	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
139	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
140		231
141	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.
142		233
143	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
144	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
…		…
146	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
147	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
148		239
149	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
150		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
151	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
152	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
153	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
154	missing, an 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).
155		251
		252	There are three variants of the timeouts that work independently
		253	of each other, for both read and write, just read, and just write:
		254	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		255	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		256	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		257
156	Note that timeout processing is also active when you currently do not have	258	Note that timeout processing is active even when you do not have
157	any outstanding read or write requests: If you plan to keep the connection	259	any outstanding read or write requests: If you plan to keep the connection
158	idle then you should disable the timout temporarily or ignore the timeout	260	idle then you should disable the timeout temporarily or ignore the timeout
159	in the C<on_timeout> callback.	261	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		262	restart the timeout.
160		263
161	Zero (the default) disables this timeout.	264	Zero (the default) disables this timeout.
162		265
163	=item on_timeout => $cb->($handle)	266	=item on_timeout => $cb->($handle)
164		267
…		…
168		271
169	=item rbuf_max => <bytes>	272	=item rbuf_max => <bytes>
170		273
171	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	274	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
172	when the read buffer ever (strictly) exceeds this size. This is useful to	275	when the read buffer ever (strictly) exceeds this size. This is useful to
173	avoid denial-of-service attacks.	276	avoid some forms of denial-of-service attacks.
174		277
175	For example, a server accepting connections from untrusted sources should	278	For example, a server accepting connections from untrusted sources should
176	be configured to accept only so-and-so much data that it cannot act on	279	be configured to accept only so-and-so much data that it cannot act on
177	(for example, when expecting a line, an attacker could send an unlimited	280	(for example, when expecting a line, an attacker could send an unlimited
178	amount of data without a callback ever being called as long as the line	281	amount of data without a callback ever being called as long as the line
179	isn't finished).	282	isn't finished).
180		283
		284	=item wbuf_max => <bytes>
		285
		286	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		287	when the write buffer ever (strictly) exceeds this size. This is useful to
		288	avoid some forms of denial-of-service attacks.
		289
		290	Although the units of this parameter is bytes, this is the I<raw> number
		291	of bytes not yet accepted by the kernel. This can make a difference when
		292	you e.g. use TLS, as TLS typically makes your write data larger (but it
		293	can also make it smaller due to compression).
		294
		295	As an example of when this limit is useful, take a chat server that sends
		296	chat messages to a client. If the client does not read those in a timely
		297	manner then the send buffer in the server would grow unbounded.
		298
181	=item autocork => <boolean>	299	=item autocork => <boolean>
182		300
183	When disabled (the default), then C<push_write> will try to immediately	301	When disabled (the default), C<push_write> will try to immediately
184	write the data to the handle if possible. This avoids having to register	302	write the data to the handle if possible. This avoids having to register
185	a write watcher and wait for the next event loop iteration, but can be	303	a write watcher and wait for the next event loop iteration, but can
186	inefficient if you write multiple small chunks (this disadvantage is	304	be inefficient if you write multiple small chunks (on the wire, this
187	usually avoided by your kernel's nagle algorithm, see C<low_delay>).	305	disadvantage is usually avoided by your kernel's nagle algorithm, see
		306	C<no_delay>, but this option can save costly syscalls).
188		307
189	When enabled, then writes will always be queued till the next event loop	308	When enabled, writes will always be queued till the next event loop
190	iteration. This is efficient when you do many small writes per iteration,	309	iteration. This is efficient when you do many small writes per iteration,
191	but less efficient when you do a single write only.	310	but less efficient when you do a single write only per iteration (or when
		311	the write buffer often is full). It also increases write latency.
192		312
193	=item no_delay => <boolean>	313	=item no_delay => <boolean>
194		314
195	When doing small writes on sockets, your operating system kernel might	315	When doing small writes on sockets, your operating system kernel might
196	wait a bit for more data before actually sending it out. This is called	316	wait a bit for more data before actually sending it out. This is called
197	the Nagle algorithm, and usually it is beneficial.	317	the Nagle algorithm, and usually it is beneficial.
198		318
199	In some situations you want as low a delay as possible, which cna be	319	In some situations you want as low a delay as possible, which can be
200	accomplishd by setting this option to true.	320	accomplishd by setting this option to a true value.
201		321
202	The default is your opertaing system's default behaviour, this option	322	The default is your operating system's default behaviour (most likely
203	explicitly enables or disables it, if possible.	323	enabled). This option explicitly enables or disables it, if possible.
		324
		325	=item keepalive => <boolean>
		326
		327	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		328	normally, TCP connections have no time-out once established, so TCP
		329	connections, once established, can stay alive forever even when the other
		330	side has long gone. TCP keepalives are a cheap way to take down long-lived
		331	TCP connections when the other side becomes unreachable. While the default
		332	is OS-dependent, TCP keepalives usually kick in after around two hours,
		333	and, if the other side doesn't reply, take down the TCP connection some 10
		334	to 15 minutes later.
		335
		336	It is harmless to specify this option for file handles that do not support
		337	keepalives, and enabling it on connections that are potentially long-lived
		338	is usually a good idea.
		339
		340	=item oobinline => <boolean>
		341
		342	BSD majorly fucked up the implementation of TCP urgent data. The result
		343	is that almost no OS implements TCP according to the specs, and every OS
		344	implements it slightly differently.
		345
		346	If you want to handle TCP urgent data, then setting this flag (the default
		347	is enabled) gives you the most portable way of getting urgent data, by
		348	putting it into the stream.
		349
		350	Since BSD emulation of OOB data on top of TCP's urgent data can have
		351	security implications, AnyEvent::Handle sets this flag automatically
		352	unless explicitly specified. Note that setting this flag after
		353	establishing a connection I<may> be a bit too late (data loss could
		354	already have occured on BSD systems), but at least it will protect you
		355	from most attacks.
204		356
205	=item read_size => <bytes>	357	=item read_size => <bytes>
206		358
207	The default read block size (the amount of bytes this module will try to read	359	The initial read block size, the number of bytes this module will try to
208	during each (loop iteration). Default: C<8192>.	360	read during each loop iteration. Each handle object will consume at least
		361	this amount of memory for the read buffer as well, so when handling many
		362	connections requirements). See also C<max_read_size>. Default: C<2048>.
		363
		364	=item max_read_size => <bytes>
		365
		366	The maximum read buffer size used by the dynamic adjustment
		367	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		368	one go it will double C<read_size> up to the maximum given by this
		369	option. Default: C<131072> or C<read_size>, whichever is higher.
209		370
210	=item low_water_mark => <bytes>	371	=item low_water_mark => <bytes>
211		372
212	Sets the amount of bytes (default: C<0>) that make up an "empty" write	373	Sets the number of bytes (default: C<0>) that make up an "empty" write
213	buffer: If the write reaches this size or gets even samller it is	374	buffer: If the buffer reaches this size or gets even samller it is
214	considered empty.	375	considered empty.
215		376
		377	Sometimes it can be beneficial (for performance reasons) to add data to
		378	the write buffer before it is fully drained, but this is a rare case, as
		379	the operating system kernel usually buffers data as well, so the default
		380	is good in almost all cases.
		381
216	=item linger => <seconds>	382	=item linger => <seconds>
217		383
218	If non-zero (default: C<3600>), then the destructor of the	384	If this is non-zero (default: C<3600>), the destructor of the
219	AnyEvent::Handle object will check wether there is still outstanding write	385	AnyEvent::Handle object will check whether there is still outstanding
220	data and will install a watcher that will write out this data. No errors	386	write data and will install a watcher that will write this data to the
221	will be reported (this mostly matches how the operating system treats	387	socket. No errors will be reported (this mostly matches how the operating
222	outstanding data at socket close time).	388	system treats outstanding data at socket close time).
223		389
224	This will not work for partial TLS data that could not yet been	390	This will not work for partial TLS data that could not be encoded
225	encoded. This data will be lost.	391	yet. This data will be lost. Calling the C<stoptls> method in time might
		392	help.
		393
		394	=item peername => $string
		395
		396	A string used to identify the remote site - usually the DNS hostname
		397	(I<not> IDN!) used to create the connection, rarely the IP address.
		398
		399	Apart from being useful in error messages, this string is also used in TLS
		400	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		401	verification will be skipped when C<peername> is not specified or is
		402	C<undef>.
226		403
227	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	404	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
228		405
229	When this parameter is given, it enables TLS (SSL) mode, that means it	406	When this parameter is given, it enables TLS (SSL) mode, that means
230	will start making tls handshake and will transparently encrypt/decrypt	407	AnyEvent will start a TLS handshake as soon as the connection has been
231	data.	408	established and will transparently encrypt/decrypt data afterwards.
		409
		410	All TLS protocol errors will be signalled as C<EPROTO>, with an
		411	appropriate error message.
232		412
233	TLS mode requires Net::SSLeay to be installed (it will be loaded	413	TLS mode requires Net::SSLeay to be installed (it will be loaded
234	automatically when you try to create a TLS handle).	414	automatically when you try to create a TLS handle): this module doesn't
		415	have a dependency on that module, so if your module requires it, you have
		416	to add the dependency yourself.
235		417
236	For the TLS server side, use C<accept>, and for the TLS client side of a	418	Unlike TCP, TLS has a server and client side: for the TLS server side, use
237	connection, use C<connect> mode.	419	C<accept>, and for the TLS client side of a connection, use C<connect>
		420	mode.
238		421
239	You can also provide your own TLS connection object, but you have	422	You can also provide your own TLS connection object, but you have
240	to make sure that you call either C<Net::SSLeay::set_connect_state>	423	to make sure that you call either C<Net::SSLeay::set_connect_state>
241	or C<Net::SSLeay::set_accept_state> on it before you pass it to	424	or C<Net::SSLeay::set_accept_state> on it before you pass it to
242	AnyEvent::Handle.	425	AnyEvent::Handle. Also, this module will take ownership of this connection
		426	object.
243		427
		428	At some future point, AnyEvent::Handle might switch to another TLS
		429	implementation, then the option to use your own session object will go
		430	away.
		431
		432	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		433	passing in the wrong integer will lead to certain crash. This most often
		434	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		435	segmentation fault.
		436
244	See the C<starttls> method if you need to start TLS negotiation later.	437	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
245		438
246	=item tls_ctx => $ssl_ctx	439	=item tls_ctx => $anyevent_tls
247		440
248	Use the given Net::SSLeay::CTX object to create the new TLS connection	441	Use the given C<AnyEvent::TLS> object to create the new TLS connection
249	(unless a connection object was specified directly). If this parameter is	442	(unless a connection object was specified directly). If this
250	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	443	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		444	C<AnyEvent::Handle::TLS_CTX>.
		445
		446	Instead of an object, you can also specify a hash reference with C<< key
		447	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		448	new TLS context object.
		449
		450	=item on_starttls => $cb->($handle, $success[, $error_message])
		451
		452	This callback will be invoked when the TLS/SSL handshake has finished. If
		453	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		454	(C<on_stoptls> will not be called in this case).
		455
		456	The session in C<< $handle->{tls} >> can still be examined in this
		457	callback, even when the handshake was not successful.
		458
		459	TLS handshake failures will not cause C<on_error> to be invoked when this
		460	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		461
		462	Without this callback, handshake failures lead to C<on_error> being
		463	called as usual.
		464
		465	Note that you cannot just call C<starttls> again in this callback. If you
		466	need to do that, start an zero-second timer instead whose callback can
		467	then call C<< ->starttls >> again.
		468
		469	=item on_stoptls => $cb->($handle)
		470
		471	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		472	set, then it will be invoked after freeing the TLS session. If it is not,
		473	then a TLS shutdown condition will be treated like a normal EOF condition
		474	on the handle.
		475
		476	The session in C<< $handle->{tls} >> can still be examined in this
		477	callback.
		478
		479	This callback will only be called on TLS shutdowns, not when the
		480	underlying handle signals EOF.
251		481
252	=item json => JSON or JSON::XS object	482	=item json => JSON or JSON::XS object
253		483
254	This is the json coder object used by the C<json> read and write types.	484	This is the json coder object used by the C<json> read and write types.
255		485
256	If you don't supply it, then AnyEvent::Handle will create and use a	486	If you don't supply it, then AnyEvent::Handle will create and use a
257	suitable one, which will write and expect UTF-8 encoded JSON texts.	487	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		488	texts.
258		489
259	Note that you are responsible to depend on the JSON module if you want to	490	Note that you are responsible to depend on the JSON module if you want to
260	use this functionality, as AnyEvent does not have a dependency itself.	491	use this functionality, as AnyEvent does not have a dependency itself.
261		492
262	=item filter_r => $cb
263
264	=item filter_w => $cb
265
266	These exist, but are undocumented at this time.
267
268	=back	493	=back
269		494
270	=cut	495	=cut
271		496
272	sub new {	497	sub new {
273	my $class = shift;	498	my $class = shift;
274
275	my $self = bless { @_ }, $class;	499	my $self = bless { @_ }, $class;
276		500
277	$self->{fh} or Carp::croak "mandatory argument fh is missing";	501	if ($self->{fh}) {
		502	$self->_start;
		503	return unless $self->{fh}; # could be gone by now
		504
		505	} elsif ($self->{connect}) {
		506	require AnyEvent::Socket;
		507
		508	$self->{peername} = $self->{connect}[0]
		509	unless exists $self->{peername};
		510
		511	$self->{_skip_drain_rbuf} = 1;
		512
		513	{
		514	Scalar::Util::weaken (my $self = $self);
		515
		516	$self->{_connect} =
		517	AnyEvent::Socket::tcp_connect (
		518	$self->{connect}[0],
		519	$self->{connect}[1],
		520	sub {
		521	my ($fh, $host, $port, $retry) = @_;
		522
		523	delete $self->{_connect}; # no longer needed
		524
		525	if ($fh) {
		526	$self->{fh} = $fh;
		527
		528	delete $self->{_skip_drain_rbuf};
		529	$self->_start;
		530
		531	$self->{on_connect}
		532	and $self->{on_connect}($self, $host, $port, sub {
		533	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		534	$self->{_skip_drain_rbuf} = 1;
		535	&$retry;
		536	});
		537
		538	} else {
		539	if ($self->{on_connect_error}) {
		540	$self->{on_connect_error}($self, "$!");
		541	$self->destroy;
		542	} else {
		543	$self->_error ($!, 1);
		544	}
		545	}
		546	},
		547	sub {
		548	local $self->{fh} = $_[0];
		549
		550	$self->{on_prepare}
		551	? $self->{on_prepare}->($self)
		552	: ()
		553	}
		554	);
		555	}
		556
		557	} else {
		558	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		559	}
		560
		561	$self
		562	}
		563
		564	sub _start {
		565	my ($self) = @_;
		566
		567	# too many clueless people try to use udp and similar sockets
		568	# with AnyEvent::Handle, do them a favour.
		569	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		570	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		571	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
278		572
279	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	573	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
280		574
281	if ($self->{tls}) {	575	$self->{_activity} =
282	require Net::SSLeay;	576	$self->{_ractivity} =
		577	$self->{_wactivity} = AE::now;
		578
		579	$self->{read_size} ||= 2048;
		580	$self->{max_read_size} = $self->{read_size}
		581	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		582
		583	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		584	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		585	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		586
		587	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		588	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		589
		590	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		591
283	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	592	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
284	}	593	if $self->{tls};
285		594
286	$self->{_activity} = AnyEvent->now;
287	$self->_timeout;
288
289	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	595	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
290	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
291		596
292	$self->start_read	597	$self->start_read
293	if $self->{on_read};	598	if $self->{on_read} || @{ $self->{_queue} };
294		599
295	$self	600	$self->_drain_wbuf;
296	}
297
298	sub _shutdown {
299	my ($self) = @_;
300
301	delete $self->{_tw};
302	delete $self->{_rw};
303	delete $self->{_ww};
304	delete $self->{fh};
305
306	$self->stoptls;
307
308	delete $self->{on_read};
309	delete $self->{_queue};
310	}	601	}
311		602
312	sub _error {	603	sub _error {
313	my ($self, $errno, $fatal) = @_;	604	my ($self, $errno, $fatal, $message) = @_;
314
315	$self->_shutdown
316	if $fatal;
317		605
318	$! = $errno;	606	$! = $errno;
		607	$message ||= "$!";
319		608
320	if ($self->{on_error}) {	609	if ($self->{on_error}) {
321	$self->{on_error}($self, $fatal);	610	$self->{on_error}($self, $fatal, $message);
322	} else {	611	$self->destroy if $fatal;
		612	} elsif ($self->{fh} || $self->{connect}) {
		613	$self->destroy;
323	Carp::croak "AnyEvent::Handle uncaught error: $!";	614	Carp::croak "AnyEvent::Handle uncaught error: $message";
324	}	615	}
325	}	616	}
326		617
327	=item $fh = $handle->fh	618	=item $fh = $handle->fh
328		619
329	This method returns the file handle of the L<AnyEvent::Handle> object.	620	This method returns the file handle used to create the L<AnyEvent::Handle> object.
330		621
331	=cut	622	=cut
332		623
333	sub fh { $_[0]{fh} }	624	sub fh { $_[0]{fh} }
334		625
…		…
352	$_[0]{on_eof} = $_[1];	643	$_[0]{on_eof} = $_[1];
353	}	644	}
354		645
355	=item $handle->on_timeout ($cb)	646	=item $handle->on_timeout ($cb)
356		647
357	Replace the current C<on_timeout> callback, or disables the callback	648	=item $handle->on_rtimeout ($cb)
358	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
359	argument.
360		649
361	=cut	650	=item $handle->on_wtimeout ($cb)
362		651
363	sub on_timeout {	652	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
364	$_[0]{on_timeout} = $_[1];	653	callback, or disables the callback (but not the timeout) if C<$cb> =
365	}	654	C<undef>. See the C<timeout> constructor argument and method.
		655
		656	=cut
		657
		658	# see below
366		659
367	=item $handle->autocork ($boolean)	660	=item $handle->autocork ($boolean)
368		661
369	Enables or disables the current autocork behaviour (see C<autocork>	662	Enables or disables the current autocork behaviour (see C<autocork>
370	constructor argument).	663	constructor argument). Changes will only take effect on the next write.
371		664
372	=cut	665	=cut
		666
		667	sub autocork {
		668	$_[0]{autocork} = $_[1];
		669	}
373		670
374	=item $handle->no_delay ($boolean)	671	=item $handle->no_delay ($boolean)
375		672
376	Enables or disables the C<no_delay> setting (see constructor argument of	673	Enables or disables the C<no_delay> setting (see constructor argument of
377	the same name for details).	674	the same name for details).
…		…
379	=cut	676	=cut
380		677
381	sub no_delay {	678	sub no_delay {
382	$_[0]{no_delay} = $_[1];	679	$_[0]{no_delay} = $_[1];
383		680
		681	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		682	if $_[0]{fh};
		683	}
		684
		685	=item $handle->keepalive ($boolean)
		686
		687	Enables or disables the C<keepalive> setting (see constructor argument of
		688	the same name for details).
		689
		690	=cut
		691
		692	sub keepalive {
		693	$_[0]{keepalive} = $_[1];
		694
384	eval {	695	eval {
385	local $SIG{__DIE__};	696	local $SIG{__DIE__};
386	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];	697	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		698	if $_[0]{fh};
387	};	699	};
388	}	700	}
389		701
		702	=item $handle->oobinline ($boolean)
		703
		704	Enables or disables the C<oobinline> setting (see constructor argument of
		705	the same name for details).
		706
		707	=cut
		708
		709	sub oobinline {
		710	$_[0]{oobinline} = $_[1];
		711
		712	eval {
		713	local $SIG{__DIE__};
		714	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		715	if $_[0]{fh};
		716	};
		717	}
		718
		719	=item $handle->keepalive ($boolean)
		720
		721	Enables or disables the C<keepalive> setting (see constructor argument of
		722	the same name for details).
		723
		724	=cut
		725
		726	sub keepalive {
		727	$_[0]{keepalive} = $_[1];
		728
		729	eval {
		730	local $SIG{__DIE__};
		731	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		732	if $_[0]{fh};
		733	};
		734	}
		735
		736	=item $handle->on_starttls ($cb)
		737
		738	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		739
		740	=cut
		741
		742	sub on_starttls {
		743	$_[0]{on_starttls} = $_[1];
		744	}
		745
		746	=item $handle->on_stoptls ($cb)
		747
		748	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		749
		750	=cut
		751
		752	sub on_stoptls {
		753	$_[0]{on_stoptls} = $_[1];
		754	}
		755
		756	=item $handle->rbuf_max ($max_octets)
		757
		758	Configures the C<rbuf_max> setting (C<undef> disables it).
		759
		760	=item $handle->wbuf_max ($max_octets)
		761
		762	Configures the C<wbuf_max> setting (C<undef> disables it).
		763
		764	=cut
		765
		766	sub rbuf_max {
		767	$_[0]{rbuf_max} = $_[1];
		768	}
		769
		770	sub wbuf_max {
		771	$_[0]{wbuf_max} = $_[1];
		772	}
		773
390	#############################################################################	774	#############################################################################
391		775
392	=item $handle->timeout ($seconds)	776	=item $handle->timeout ($seconds)
393		777
		778	=item $handle->rtimeout ($seconds)
		779
		780	=item $handle->wtimeout ($seconds)
		781
394	Configures (or disables) the inactivity timeout.	782	Configures (or disables) the inactivity timeout.
395		783
396	=cut	784	=item $handle->timeout_reset
397		785
398	sub timeout {	786	=item $handle->rtimeout_reset
		787
		788	=item $handle->wtimeout_reset
		789
		790	Reset the activity timeout, as if data was received or sent.
		791
		792	These methods are cheap to call.
		793
		794	=cut
		795
		796	for my $dir ("", "r", "w") {
		797	my $timeout = "${dir}timeout";
		798	my $tw = "_${dir}tw";
		799	my $on_timeout = "on_${dir}timeout";
		800	my $activity = "_${dir}activity";
		801	my $cb;
		802
		803	*$on_timeout = sub {
		804	$_[0]{$on_timeout} = $_[1];
		805	};
		806
		807	*$timeout = sub {
399	my ($self, $timeout) = @_;	808	my ($self, $new_value) = @_;
400		809
		810	$new_value >= 0
		811	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		812
401	$self->{timeout} = $timeout;	813	$self->{$timeout} = $new_value;
402	$self->_timeout;	814	delete $self->{$tw}; &$cb;
403	}	815	};
404		816
		817	*{"${dir}timeout_reset"} = sub {
		818	$_[0]{$activity} = AE::now;
		819	};
		820
		821	# main workhorse:
405	# reset the timeout watcher, as neccessary	822	# reset the timeout watcher, as neccessary
406	# also check for time-outs	823	# also check for time-outs
407	sub _timeout {	824	$cb = sub {
408	my ($self) = @_;	825	my ($self) = @_;
409		826
410	if ($self->{timeout}) {	827	if ($self->{$timeout} && $self->{fh}) {
411	my $NOW = AnyEvent->now;	828	my $NOW = AE::now;
412		829
413	# when would the timeout trigger?	830	# when would the timeout trigger?
414	my $after = $self->{_activity} + $self->{timeout} - $NOW;	831	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
415		832
416	# now or in the past already?	833	# now or in the past already?
417	if ($after <= 0) {	834	if ($after <= 0) {
418	$self->{_activity} = $NOW;	835	$self->{$activity} = $NOW;
419		836
420	if ($self->{on_timeout}) {	837	if ($self->{$on_timeout}) {
421	$self->{on_timeout}($self);	838	$self->{$on_timeout}($self);
422	} else {	839	} else {
423	$self->_error (&Errno::ETIMEDOUT);	840	$self->_error (Errno::ETIMEDOUT);
		841	}
		842
		843	# callback could have changed timeout value, optimise
		844	return unless $self->{$timeout};
		845
		846	# calculate new after
		847	$after = $self->{$timeout};
424	}	848	}
425		849
426	# callback could have changed timeout value, optimise	850	Scalar::Util::weaken $self;
427	return unless $self->{timeout};	851	return unless $self; # ->error could have destroyed $self
428		852
429	# calculate new after	853	$self->{$tw} ||= AE::timer $after, 0, sub {
430	$after = $self->{timeout};	854	delete $self->{$tw};
		855	$cb->($self);
		856	};
		857	} else {
		858	delete $self->{$tw};
431	}	859	}
432
433	Scalar::Util::weaken $self;
434	return unless $self; # ->error could have destroyed $self
435
436	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
437	delete $self->{_tw};
438	$self->_timeout;
439	});
440	} else {
441	delete $self->{_tw};
442	}	860	}
443	}	861	}
444		862
445	#############################################################################	863	#############################################################################
446		864
…		…
462	=item $handle->on_drain ($cb)	880	=item $handle->on_drain ($cb)
463		881
464	Sets the C<on_drain> callback or clears it (see the description of	882	Sets the C<on_drain> callback or clears it (see the description of
465	C<on_drain> in the constructor).	883	C<on_drain> in the constructor).
466		884
		885	This method may invoke callbacks (and therefore the handle might be
		886	destroyed after it returns).
		887
467	=cut	888	=cut
468		889
469	sub on_drain {	890	sub on_drain {
470	my ($self, $cb) = @_;	891	my ($self, $cb) = @_;
471		892
472	$self->{on_drain} = $cb;	893	$self->{on_drain} = $cb;
473		894
474	$cb->($self)	895	$cb->($self)
475	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	896	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
476	}	897	}
477		898
478	=item $handle->push_write ($data)	899	=item $handle->push_write ($data)
479		900
480	Queues the given scalar to be written. You can push as much data as you	901	Queues the given scalar to be written. You can push as much data as
481	want (only limited by the available memory), as C<AnyEvent::Handle>	902	you want (only limited by the available memory and C<wbuf_max>), as
482	buffers it independently of the kernel.	903	C<AnyEvent::Handle> buffers it independently of the kernel.
		904
		905	This method may invoke callbacks (and therefore the handle might be
		906	destroyed after it returns).
483		907
484	=cut	908	=cut
485		909
486	sub _drain_wbuf {	910	sub _drain_wbuf {
487	my ($self) = @_;	911	my ($self) = @_;
…		…
491	Scalar::Util::weaken $self;	915	Scalar::Util::weaken $self;
492		916
493	my $cb = sub {	917	my $cb = sub {
494	my $len = syswrite $self->{fh}, $self->{wbuf};	918	my $len = syswrite $self->{fh}, $self->{wbuf};
495		919
496	if ($len >= 0) {	920	if (defined $len) {
497	substr $self->{wbuf}, 0, $len, "";	921	substr $self->{wbuf}, 0, $len, "";
498		922
499	$self->{_activity} = AnyEvent->now;	923	$self->{_activity} = $self->{_wactivity} = AE::now;
500		924
501	$self->{on_drain}($self)	925	$self->{on_drain}($self)
502	if $self->{low_water_mark} >= length $self->{wbuf}	926	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
503	&& $self->{on_drain};	927	&& $self->{on_drain};
504		928
505	delete $self->{_ww} unless length $self->{wbuf};	929	delete $self->{_ww} unless length $self->{wbuf};
506	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	930	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
507	$self->_error ($!, 1);	931	$self->_error ($!, 1);
…		…
510		934
511	# try to write data immediately	935	# try to write data immediately
512	$cb->() unless $self->{autocork};	936	$cb->() unless $self->{autocork};
513		937
514	# if still data left in wbuf, we need to poll	938	# if still data left in wbuf, we need to poll
515	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	939	$self->{_ww} = AE::io $self->{fh}, 1, $cb
516	if length $self->{wbuf};	940	if length $self->{wbuf};
		941
		942	if (
		943	defined $self->{wbuf_max}
		944	&& $self->{wbuf_max} < length $self->{wbuf}
		945	) {
		946	$self->_error (Errno::ENOSPC, 1), return;
		947	}
517	};	948	};
518	}	949	}
519		950
520	our %WH;	951	our %WH;
521		952
		953	# deprecated
522	sub register_write_type($$) {	954	sub register_write_type($$) {
523	$WH{$_[0]} = $_[1];	955	$WH{$_[0]} = $_[1];
524	}	956	}
525		957
526	sub push_write {	958	sub push_write {
527	my $self = shift;	959	my $self = shift;
528		960
529	if (@_ > 1) {	961	if (@_ > 1) {
530	my $type = shift;	962	my $type = shift;
531		963
		964	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
532	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	965	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
533	->($self, @_);	966	->($self, @_);
534	}	967	}
535		968
		969	# we downgrade here to avoid hard-to-track-down bugs,
		970	# and diagnose the problem earlier and better.
		971
536	if ($self->{filter_w}) {	972	if ($self->{tls}) {
537	$self->{filter_w}($self, \$_[0]);	973	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		974	&_dotls ($self) if $self->{fh};
538	} else {	975	} else {
539	$self->{wbuf} .= $_[0];	976	utf8::downgrade $self->{wbuf} .= $_[0];
540	$self->_drain_wbuf;	977	$self->_drain_wbuf if $self->{fh};
541	}	978	}
542	}	979	}
543		980
544	=item $handle->push_write (type => @args)	981	=item $handle->push_write (type => @args)
545		982
546	Instead of formatting your data yourself, you can also let this module do	983	Instead of formatting your data yourself, you can also let this module
547	the job by specifying a type and type-specific arguments.	984	do the job by specifying a type and type-specific arguments. You
		985	can also specify the (fully qualified) name of a package, in which
		986	case AnyEvent tries to load the package and then expects to find the
		987	C<anyevent_write_type> function inside (see "custom write types", below).
548		988
549	Predefined types are (if you have ideas for additional types, feel free to	989	Predefined types are (if you have ideas for additional types, feel free to
550	drop by and tell us):	990	drop by and tell us):
551		991
552	=over 4	992	=over 4
…		…
559	=cut	999	=cut
560		1000
561	register_write_type netstring => sub {	1001	register_write_type netstring => sub {
562	my ($self, $string) = @_;	1002	my ($self, $string) = @_;
563		1003
564	sprintf "%d:%s,", (length $string), $string	1004	(length $string) . ":$string,"
565	};	1005	};
566		1006
567	=item packstring => $format, $data	1007	=item packstring => $format, $data
568		1008
569	An octet string prefixed with an encoded length. The encoding C<$format>	1009	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
609	Other languages could read single lines terminated by a newline and pass	1049	Other languages could read single lines terminated by a newline and pass
610	this line into their JSON decoder of choice.	1050	this line into their JSON decoder of choice.
611		1051
612	=cut	1052	=cut
613		1053
		1054	sub json_coder() {
		1055	eval { require JSON::XS; JSON::XS->new->utf8 }
		1056	|| do { require JSON; JSON->new->utf8 }
		1057	}
		1058
614	register_write_type json => sub {	1059	register_write_type json => sub {
615	my ($self, $ref) = @_;	1060	my ($self, $ref) = @_;
616		1061
617	require JSON;	1062	my $json = $self->{json} ||= json_coder;
618		1063
619	$self->{json} ? $self->{json}->encode ($ref)	1064	$json->encode ($ref)
620	: JSON::encode_json ($ref)
621	};	1065	};
622		1066
623	=item storable => $reference	1067	=item storable => $reference
624		1068
625	Freezes the given reference using L<Storable> and writes it to the	1069	Freezes the given reference using L<Storable> and writes it to the
…		…
635	pack "w/a*", Storable::nfreeze ($ref)	1079	pack "w/a*", Storable::nfreeze ($ref)
636	};	1080	};
637		1081
638	=back	1082	=back
639		1083
640	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1084	=item $handle->push_shutdown
641		1085
642	This function (not method) lets you add your own types to C<push_write>.	1086	Sometimes you know you want to close the socket after writing your data
		1087	before it was actually written. One way to do that is to replace your
		1088	C<on_drain> handler by a callback that shuts down the socket (and set
		1089	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1090	replaces the C<on_drain> callback with:
		1091
		1092	sub { shutdown $_[0]{fh}, 1 }
		1093
		1094	This simply shuts down the write side and signals an EOF condition to the
		1095	the peer.
		1096
		1097	You can rely on the normal read queue and C<on_eof> handling
		1098	afterwards. This is the cleanest way to close a connection.
		1099
		1100	This method may invoke callbacks (and therefore the handle might be
		1101	destroyed after it returns).
		1102
		1103	=cut
		1104
		1105	sub push_shutdown {
		1106	my ($self) = @_;
		1107
		1108	delete $self->{low_water_mark};
		1109	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1110	}
		1111
		1112	=item custom write types - Package::anyevent_write_type $handle, @args
		1113
		1114	Instead of one of the predefined types, you can also specify the name of
		1115	a package. AnyEvent will try to load the package and then expects to find
		1116	a function named C<anyevent_write_type> inside. If it isn't found, it
		1117	progressively tries to load the parent package until it either finds the
		1118	function (good) or runs out of packages (bad).
		1119
643	Whenever the given C<type> is used, C<push_write> will invoke the code	1120	Whenever the given C<type> is used, C<push_write> will the function with
644	reference with the handle object and the remaining arguments.	1121	the handle object and the remaining arguments.
645		1122
646	The code reference is supposed to return a single octet string that will	1123	The function is supposed to return a single octet string that will be
647	be appended to the write buffer.	1124	appended to the write buffer, so you cna mentally treat this function as a
		1125	"arguments to on-the-wire-format" converter.
648		1126
649	Note that this is a function, and all types registered this way will be	1127	Example: implement a custom write type C<join> that joins the remaining
650	global, so try to use unique names.	1128	arguments using the first one.
		1129
		1130	$handle->push_write (My::Type => " ", 1,2,3);
		1131
		1132	# uses the following package, which can be defined in the "My::Type" or in
		1133	# the "My" modules to be auto-loaded, or just about anywhere when the
		1134	# My::Type::anyevent_write_type is defined before invoking it.
		1135
		1136	package My::Type;
		1137
		1138	sub anyevent_write_type {
		1139	my ($handle, $delim, @args) = @_;
		1140
		1141	join $delim, @args
		1142	}
651		1143
652	=cut	1144	=cut
653		1145
654	#############################################################################	1146	#############################################################################
655		1147
…		…
664	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1156	ways, the "simple" way, using only C<on_read> and the "complex" way, using
665	a queue.	1157	a queue.
666		1158
667	In the simple case, you just install an C<on_read> callback and whenever	1159	In the simple case, you just install an C<on_read> callback and whenever
668	new data arrives, it will be called. You can then remove some data (if	1160	new data arrives, it will be called. You can then remove some data (if
669	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1161	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
670	leave the data there if you want to accumulate more (e.g. when only a	1162	leave the data there if you want to accumulate more (e.g. when only a
671	partial message has been received so far).	1163	partial message has been received so far), or change the read queue with
		1164	e.g. C<push_read>.
672		1165
673	In the more complex case, you want to queue multiple callbacks. In this	1166	In the more complex case, you want to queue multiple callbacks. In this
674	case, AnyEvent::Handle will call the first queued callback each time new	1167	case, AnyEvent::Handle will call the first queued callback each time new
675	data arrives (also the first time it is queued) and removes it when it has	1168	data arrives (also the first time it is queued) and remove it when it has
676	done its job (see C<push_read>, below).	1169	done its job (see C<push_read>, below).
677		1170
678	This way you can, for example, push three line-reads, followed by reading	1171	This way you can, for example, push three line-reads, followed by reading
679	a chunk of data, and AnyEvent::Handle will execute them in order.	1172	a chunk of data, and AnyEvent::Handle will execute them in order.
680		1173
…		…
737	=cut	1230	=cut
738		1231
739	sub _drain_rbuf {	1232	sub _drain_rbuf {
740	my ($self) = @_;	1233	my ($self) = @_;
741		1234
		1235	# avoid recursion
		1236	return if $self->{_skip_drain_rbuf};
742	local $self->{_in_drain} = 1;	1237	local $self->{_skip_drain_rbuf} = 1;
743
744	if (
745	defined $self->{rbuf_max}
746	&& $self->{rbuf_max} < length $self->{rbuf}
747	) {
748	$self->_error (&Errno::ENOSPC, 1), return;
749	}
750		1238
751	while () {	1239	while () {
		1240	# we need to use a separate tls read buffer, as we must not receive data while
		1241	# we are draining the buffer, and this can only happen with TLS.
		1242	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1243	if exists $self->{_tls_rbuf};
		1244
752	my $len = length $self->{rbuf};	1245	my $len = length $self->{rbuf};
753		1246
754	if (my $cb = shift @{ $self->{_queue} }) {	1247	if (my $cb = shift @{ $self->{_queue} }) {
755	unless ($cb->($self)) {	1248	unless ($cb->($self)) {
756	if ($self->{_eof}) {	1249	# no progress can be made
757	# no progress can be made (not enough data and no data forthcoming)	1250	# (not enough data and no data forthcoming)
758	$self->_error (&Errno::EPIPE, 1), return;	1251	$self->_error (Errno::EPIPE, 1), return
759	}	1252	if $self->{_eof};
760		1253
761	unshift @{ $self->{_queue} }, $cb;	1254	unshift @{ $self->{_queue} }, $cb;
762	last;	1255	last;
763	}	1256	}
764	} elsif ($self->{on_read}) {	1257	} elsif ($self->{on_read}) {
…		…
771	&& !@{ $self->{_queue} } # and the queue is still empty	1264	&& !@{ $self->{_queue} } # and the queue is still empty
772	&& $self->{on_read} # but we still have on_read	1265	&& $self->{on_read} # but we still have on_read
773	) {	1266	) {
774	# no further data will arrive	1267	# no further data will arrive
775	# so no progress can be made	1268	# so no progress can be made
776	$self->_error (&Errno::EPIPE, 1), return	1269	$self->_error (Errno::EPIPE, 1), return
777	if $self->{_eof};	1270	if $self->{_eof};
778		1271
779	last; # more data might arrive	1272	last; # more data might arrive
780	}	1273	}
781	} else {	1274	} else {
782	# read side becomes idle	1275	# read side becomes idle
783	delete $self->{_rw};	1276	delete $self->{_rw} unless $self->{tls};
784	last;	1277	last;
785	}	1278	}
786	}	1279	}
787		1280
788	if ($self->{_eof}) {	1281	if ($self->{_eof}) {
789	if ($self->{on_eof}) {	1282	$self->{on_eof}
790	$self->{on_eof}($self)	1283	? $self->{on_eof}($self)
791	} else {	1284	: $self->_error (0, 1, "Unexpected end-of-file");
792	$self->_error (0, 1);	1285
793	}	1286	return;
		1287	}
		1288
		1289	if (
		1290	defined $self->{rbuf_max}
		1291	&& $self->{rbuf_max} < length $self->{rbuf}
		1292	) {
		1293	$self->_error (Errno::ENOSPC, 1), return;
794	}	1294	}
795		1295
796	# may need to restart read watcher	1296	# may need to restart read watcher
797	unless ($self->{_rw}) {	1297	unless ($self->{_rw}) {
798	$self->start_read	1298	$self->start_read
…		…
804		1304
805	This replaces the currently set C<on_read> callback, or clears it (when	1305	This replaces the currently set C<on_read> callback, or clears it (when
806	the new callback is C<undef>). See the description of C<on_read> in the	1306	the new callback is C<undef>). See the description of C<on_read> in the
807	constructor.	1307	constructor.
808		1308
		1309	This method may invoke callbacks (and therefore the handle might be
		1310	destroyed after it returns).
		1311
809	=cut	1312	=cut
810		1313
811	sub on_read {	1314	sub on_read {
812	my ($self, $cb) = @_;	1315	my ($self, $cb) = @_;
813		1316
814	$self->{on_read} = $cb;	1317	$self->{on_read} = $cb;
815	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1318	$self->_drain_rbuf if $cb;
816	}	1319	}
817		1320
818	=item $handle->rbuf	1321	=item $handle->rbuf
819		1322
820	Returns the read buffer (as a modifiable lvalue).	1323	Returns the read buffer (as a modifiable lvalue). You can also access the
		1324	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1325	much faster, and no less clean).
821		1326
822	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1327	The only operation allowed on the read buffer (apart from looking at it)
823	you want.	1328	is removing data from its beginning. Otherwise modifying or appending to
		1329	it is not allowed and will lead to hard-to-track-down bugs.
824		1330
825	NOTE: The read buffer should only be used or modified if the C<on_read>,	1331	NOTE: The read buffer should only be used or modified in the C<on_read>
826	C<push_read> or C<unshift_read> methods are used. The other read methods	1332	callback or when C<push_read> or C<unshift_read> are used with a single
827	automatically manage the read buffer.	1333	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1334	will manage the read buffer on their own.
828		1335
829	=cut	1336	=cut
830		1337
831	sub rbuf : lvalue {	1338	sub rbuf : lvalue {
832	$_[0]{rbuf}	1339	$_[0]{rbuf}
…		…
849		1356
850	If enough data was available, then the callback must remove all data it is	1357	If enough data was available, then the callback must remove all data it is
851	interested in (which can be none at all) and return a true value. After returning	1358	interested in (which can be none at all) and return a true value. After returning
852	true, it will be removed from the queue.	1359	true, it will be removed from the queue.
853		1360
		1361	These methods may invoke callbacks (and therefore the handle might be
		1362	destroyed after it returns).
		1363
854	=cut	1364	=cut
855		1365
856	our %RH;	1366	our %RH;
857		1367
858	sub register_read_type($$) {	1368	sub register_read_type($$) {
…		…
864	my $cb = pop;	1374	my $cb = pop;
865		1375
866	if (@_) {	1376	if (@_) {
867	my $type = shift;	1377	my $type = shift;
868		1378
		1379	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
869	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1380	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
870	->($self, $cb, @_);	1381	->($self, $cb, @_);
871	}	1382	}
872		1383
873	push @{ $self->{_queue} }, $cb;	1384	push @{ $self->{_queue} }, $cb;
874	$self->_drain_rbuf unless $self->{_in_drain};	1385	$self->_drain_rbuf;
875	}	1386	}
876		1387
877	sub unshift_read {	1388	sub unshift_read {
878	my $self = shift;	1389	my $self = shift;
879	my $cb = pop;	1390	my $cb = pop;
880		1391
881	if (@_) {	1392	if (@_) {
882	my $type = shift;	1393	my $type = shift;
883		1394
		1395	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
884	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1396	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
885	->($self, $cb, @_);	1397	->($self, $cb, @_);
886	}	1398	}
887		1399
888
889	unshift @{ $self->{_queue} }, $cb;	1400	unshift @{ $self->{_queue} }, $cb;
890	$self->_drain_rbuf unless $self->{_in_drain};	1401	$self->_drain_rbuf;
891	}	1402	}
892		1403
893	=item $handle->push_read (type => @args, $cb)	1404	=item $handle->push_read (type => @args, $cb)
894		1405
895	=item $handle->unshift_read (type => @args, $cb)	1406	=item $handle->unshift_read (type => @args, $cb)
896		1407
897	Instead of providing a callback that parses the data itself you can chose	1408	Instead of providing a callback that parses the data itself you can chose
898	between a number of predefined parsing formats, for chunks of data, lines	1409	between a number of predefined parsing formats, for chunks of data, lines
899	etc.	1410	etc. You can also specify the (fully qualified) name of a package, in
		1411	which case AnyEvent tries to load the package and then expects to find the
		1412	C<anyevent_read_type> function inside (see "custom read types", below).
900		1413
901	Predefined types are (if you have ideas for additional types, feel free to	1414	Predefined types are (if you have ideas for additional types, feel free to
902	drop by and tell us):	1415	drop by and tell us):
903		1416
904	=over 4	1417	=over 4
…		…
996	the receive buffer when neither C<$accept> nor C<$reject> match,	1509	the receive buffer when neither C<$accept> nor C<$reject> match,
997	and everything preceding and including the match will be accepted	1510	and everything preceding and including the match will be accepted
998	unconditionally. This is useful to skip large amounts of data that you	1511	unconditionally. This is useful to skip large amounts of data that you
999	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1512	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1000	have to start matching from the beginning. This is purely an optimisation	1513	have to start matching from the beginning. This is purely an optimisation
1001	and is usually worth only when you expect more than a few kilobytes.	1514	and is usually worth it only when you expect more than a few kilobytes.
1002		1515
1003	Example: expect a http header, which ends at C<\015\012\015\012>. Since we	1516	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1004	expect the header to be very large (it isn't in practise, but...), we use	1517	expect the header to be very large (it isn't in practice, but...), we use
1005	a skip regex to skip initial portions. The skip regex is tricky in that	1518	a skip regex to skip initial portions. The skip regex is tricky in that
1006	it only accepts something not ending in either \015 or \012, as these are	1519	it only accepts something not ending in either \015 or \012, as these are
1007	required for the accept regex.	1520	required for the accept regex.
1008		1521
1009	$handle->push_read (regex =>	1522	$handle->push_read (regex =>
…		…
1028	return 1;	1541	return 1;
1029	}	1542	}
1030		1543
1031	# reject	1544	# reject
1032	if ($reject && $$rbuf =~ $reject) {	1545	if ($reject && $$rbuf =~ $reject) {
1033	$self->_error (&Errno::EBADMSG);	1546	$self->_error (Errno::EBADMSG);
1034	}	1547	}
1035		1548
1036	# skip	1549	# skip
1037	if ($skip && $$rbuf =~ $skip) {	1550	if ($skip && $$rbuf =~ $skip) {
1038	$data .= substr $$rbuf, 0, $+[0], "";	1551	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1054	my ($self, $cb) = @_;	1567	my ($self, $cb) = @_;
1055		1568
1056	sub {	1569	sub {
1057	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1570	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1058	if ($_[0]{rbuf} =~ /[^0-9]/) {	1571	if ($_[0]{rbuf} =~ /[^0-9]/) {
1059	$self->_error (&Errno::EBADMSG);	1572	$self->_error (Errno::EBADMSG);
1060	}	1573	}
1061	return;	1574	return;
1062	}	1575	}
1063		1576
1064	my $len = $1;	1577	my $len = $1;
…		…
1067	my $string = $_[1];	1580	my $string = $_[1];
1068	$_[0]->unshift_read (chunk => 1, sub {	1581	$_[0]->unshift_read (chunk => 1, sub {
1069	if ($_[1] eq ",") {	1582	if ($_[1] eq ",") {
1070	$cb->($_[0], $string);	1583	$cb->($_[0], $string);
1071	} else {	1584	} else {
1072	$self->_error (&Errno::EBADMSG);	1585	$self->_error (Errno::EBADMSG);
1073	}	1586	}
1074	});	1587	});
1075	});	1588	});
1076		1589
1077	1	1590	1
…		…
1083	An octet string prefixed with an encoded length. The encoding C<$format>	1596	An octet string prefixed with an encoded length. The encoding C<$format>
1084	uses the same format as a Perl C<pack> format, but must specify a single	1597	uses the same format as a Perl C<pack> format, but must specify a single
1085	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1598	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1086	optional C<!>, C<< < >> or C<< > >> modifier).	1599	optional C<!>, C<< < >> or C<< > >> modifier).
1087		1600
1088	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.	1601	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1602	EPP uses a prefix of C<N> (4 octtes).
1089		1603
1090	Example: read a block of data prefixed by its length in BER-encoded	1604	Example: read a block of data prefixed by its length in BER-encoded
1091	format (very efficient).	1605	format (very efficient).
1092		1606
1093	$handle->push_read (packstring => "w", sub {	1607	$handle->push_read (packstring => "w", sub {
…		…
1123	}	1637	}
1124	};	1638	};
1125		1639
1126	=item json => $cb->($handle, $hash_or_arrayref)	1640	=item json => $cb->($handle, $hash_or_arrayref)
1127		1641
1128	Reads a JSON object or array, decodes it and passes it to the callback.	1642	Reads a JSON object or array, decodes it and passes it to the
		1643	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1129		1644
1130	If a C<json> object was passed to the constructor, then that will be used	1645	If a C<json> object was passed to the constructor, then that will be used
1131	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1646	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1132		1647
1133	This read type uses the incremental parser available with JSON version	1648	This read type uses the incremental parser available with JSON version
…		…
1142	=cut	1657	=cut
1143		1658
1144	register_read_type json => sub {	1659	register_read_type json => sub {
1145	my ($self, $cb) = @_;	1660	my ($self, $cb) = @_;
1146		1661
1147	require JSON;	1662	my $json = $self->{json} ||= json_coder;
1148		1663
1149	my $data;	1664	my $data;
1150	my $rbuf = \$self->{rbuf};	1665	my $rbuf = \$self->{rbuf};
1151		1666
1152	my $json = $self->{json} ||= JSON->new->utf8;
1153
1154	sub {	1667	sub {
1155	my $ref = $json->incr_parse ($self->{rbuf});	1668	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1156		1669
1157	if ($ref) {	1670	if ($ref) {
1158	$self->{rbuf} = $json->incr_text;	1671	$self->{rbuf} = $json->incr_text;
1159	$json->incr_text = "";	1672	$json->incr_text = "";
1160	$cb->($self, $ref);	1673	$cb->($self, $ref);
1161		1674
1162	1	1675	1
		1676	} elsif ($@) {
		1677	# error case
		1678	$json->incr_skip;
		1679
		1680	$self->{rbuf} = $json->incr_text;
		1681	$json->incr_text = "";
		1682
		1683	$self->_error (Errno::EBADMSG);
		1684
		1685	()
1163	} else {	1686	} else {
1164	$self->{rbuf} = "";	1687	$self->{rbuf} = "";
		1688
1165	()	1689	()
1166	}	1690	}
1167	}	1691	}
1168	};	1692	};
1169		1693
…		…
1201	# read remaining chunk	1725	# read remaining chunk
1202	$_[0]->unshift_read (chunk => $len, sub {	1726	$_[0]->unshift_read (chunk => $len, sub {
1203	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1727	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1204	$cb->($_[0], $ref);	1728	$cb->($_[0], $ref);
1205	} else {	1729	} else {
1206	$self->_error (&Errno::EBADMSG);	1730	$self->_error (Errno::EBADMSG);
1207	}	1731	}
1208	});	1732	});
1209	}	1733	}
1210		1734
1211	1	1735	1
1212	}	1736	}
1213	};	1737	};
1214		1738
1215	=back	1739	=back
1216		1740
1217	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1741	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1218		1742
1219	This function (not method) lets you add your own types to C<push_read>.	1743	Instead of one of the predefined types, you can also specify the name
		1744	of a package. AnyEvent will try to load the package and then expects to
		1745	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1746	progressively tries to load the parent package until it either finds the
		1747	function (good) or runs out of packages (bad).
1220		1748
1221	Whenever the given C<type> is used, C<push_read> will invoke the code	1749	Whenever this type is used, C<push_read> will invoke the function with the
1222	reference with the handle object, the callback and the remaining	1750	handle object, the original callback and the remaining arguments.
1223	arguments.
1224		1751
1225	The code reference is supposed to return a callback (usually a closure)	1752	The function is supposed to return a callback (usually a closure) that
1226	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1753	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1754	mentally treat the function as a "configurable read type to read callback"
		1755	converter.
1227		1756
1228	It should invoke the passed callback when it is done reading (remember to	1757	It should invoke the original callback when it is done reading (remember
1229	pass C<$handle> as first argument as all other callbacks do that).	1758	to pass C<$handle> as first argument as all other callbacks do that,
		1759	although there is no strict requirement on this).
1230		1760
1231	Note that this is a function, and all types registered this way will be
1232	global, so try to use unique names.
1233
1234	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1761	For examples, see the source of this module (F<perldoc -m
1235	search for C<register_read_type>)).	1762	AnyEvent::Handle>, search for C<register_read_type>)).
1236		1763
1237	=item $handle->stop_read	1764	=item $handle->stop_read
1238		1765
1239	=item $handle->start_read	1766	=item $handle->start_read
1240		1767
…		…
1246	Note that AnyEvent::Handle will automatically C<start_read> for you when	1773	Note that AnyEvent::Handle will automatically C<start_read> for you when
1247	you change the C<on_read> callback or push/unshift a read callback, and it	1774	you change the C<on_read> callback or push/unshift a read callback, and it
1248	will automatically C<stop_read> for you when neither C<on_read> is set nor	1775	will automatically C<stop_read> for you when neither C<on_read> is set nor
1249	there are any read requests in the queue.	1776	there are any read requests in the queue.
1250		1777
		1778	In older versions of this module (<= 5.3), these methods had no effect,
		1779	as TLS does not support half-duplex connections. In current versions they
		1780	work as expected, as this behaviour is required to avoid certain resource
		1781	attacks, where the program would be forced to read (and buffer) arbitrary
		1782	amounts of data before being able to send some data. The drawback is that
		1783	some readings of the the SSL/TLS specifications basically require this
		1784	attack to be working, as SSL/TLS implementations might stall sending data
		1785	during a rehandshake.
		1786
		1787	As a guideline, during the initial handshake, you should not stop reading,
		1788	and as a client, it might cause problems, depending on your applciation.
		1789
1251	=cut	1790	=cut
1252		1791
1253	sub stop_read {	1792	sub stop_read {
1254	my ($self) = @_;	1793	my ($self) = @_;
1255		1794
…		…
1257	}	1796	}
1258		1797
1259	sub start_read {	1798	sub start_read {
1260	my ($self) = @_;	1799	my ($self) = @_;
1261		1800
1262	unless ($self->{_rw} || $self->{_eof}) {	1801	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1263	Scalar::Util::weaken $self;	1802	Scalar::Util::weaken $self;
1264		1803
1265	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1804	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1266	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1805	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1267	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1806	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1268		1807
1269	if ($len > 0) {	1808	if ($len > 0) {
1270	$self->{_activity} = AnyEvent->now;	1809	$self->{_activity} = $self->{_ractivity} = AE::now;
1271		1810
1272	$self->{filter_r}	1811	if ($self->{tls}) {
1273	? $self->{filter_r}($self, $rbuf)	1812	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1274	: $self->{_in_drain} || $self->_drain_rbuf;	1813
		1814	&_dotls ($self);
		1815	} else {
		1816	$self->_drain_rbuf;
		1817	}
		1818
		1819	if ($len == $self->{read_size}) {
		1820	$self->{read_size} *= 2;
		1821	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1822	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1823	}
1275		1824
1276	} elsif (defined $len) {	1825	} elsif (defined $len) {
1277	delete $self->{_rw};	1826	delete $self->{_rw};
1278	$self->{_eof} = 1;	1827	$self->{_eof} = 1;
1279	$self->_drain_rbuf unless $self->{_in_drain};	1828	$self->_drain_rbuf;
1280		1829
1281	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1830	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1282	return $self->_error ($!, 1);	1831	return $self->_error ($!, 1);
1283	}	1832	}
1284	});	1833	};
1285	}	1834	}
1286	}	1835	}
1287		1836
		1837	our $ERROR_SYSCALL;
		1838	our $ERROR_WANT_READ;
		1839
		1840	sub _tls_error {
		1841	my ($self, $err) = @_;
		1842
		1843	return $self->_error ($!, 1)
		1844	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1845
		1846	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1847
		1848	# reduce error string to look less scary
		1849	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1850
		1851	if ($self->{_on_starttls}) {
		1852	(delete $self->{_on_starttls})->($self, undef, $err);
		1853	&_freetls;
		1854	} else {
		1855	&_freetls;
		1856	$self->_error (Errno::EPROTO, 1, $err);
		1857	}
		1858	}
		1859
		1860	# poll the write BIO and send the data if applicable
		1861	# also decode read data if possible
		1862	# this is basiclaly our TLS state machine
		1863	# more efficient implementations are possible with openssl,
		1864	# but not with the buggy and incomplete Net::SSLeay.
1288	sub _dotls {	1865	sub _dotls {
1289	my ($self) = @_;	1866	my ($self) = @_;
1290		1867
1291	my $buf;	1868	my $tmp;
1292		1869
1293	if (length $self->{_tls_wbuf}) {	1870	if (length $self->{_tls_wbuf}) {
1294	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1871	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1295	substr $self->{_tls_wbuf}, 0, $len, "";	1872	substr $self->{_tls_wbuf}, 0, $tmp, "";
1296	}	1873	}
1297	}
1298		1874
		1875	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1876	return $self->_tls_error ($tmp)
		1877	if $tmp != $ERROR_WANT_READ
		1878	&& ($tmp != $ERROR_SYSCALL || $!);
		1879	}
		1880
		1881	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1882	unless (length $tmp) {
		1883	$self->{_on_starttls}
		1884	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1885	&_freetls;
		1886
		1887	if ($self->{on_stoptls}) {
		1888	$self->{on_stoptls}($self);
		1889	return;
		1890	} else {
		1891	# let's treat SSL-eof as we treat normal EOF
		1892	delete $self->{_rw};
		1893	$self->{_eof} = 1;
		1894	}
		1895	}
		1896
		1897	$self->{_tls_rbuf} .= $tmp;
		1898	$self->_drain_rbuf;
		1899	$self->{tls} or return; # tls session might have gone away in callback
		1900	}
		1901
		1902	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1903	return $self->_tls_error ($tmp)
		1904	if $tmp != $ERROR_WANT_READ
		1905	&& ($tmp != $ERROR_SYSCALL || $!);
		1906
1299	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1907	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1300	$self->{wbuf} .= $buf;	1908	$self->{wbuf} .= $tmp;
1301	$self->_drain_wbuf;	1909	$self->_drain_wbuf;
		1910	$self->{tls} or return; # tls session might have gone away in callback
1302	}	1911	}
1303		1912
1304	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1913	$self->{_on_starttls}
1305	if (length $buf) {	1914	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1306	$self->{rbuf} .= $buf;	1915	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1307	$self->_drain_rbuf unless $self->{_in_drain};
1308	} else {
1309	# let's treat SSL-eof as we treat normal EOF
1310	$self->{_eof} = 1;
1311	$self->_shutdown;
1312	return;
1313	}
1314	}
1315
1316	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1317
1318	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1319	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1320	return $self->_error ($!, 1);
1321	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1322	return $self->_error (&Errno::EIO, 1);
1323	}
1324
1325	# all others are fine for our purposes
1326	}
1327	}	1916	}
1328		1917
1329	=item $handle->starttls ($tls[, $tls_ctx])	1918	=item $handle->starttls ($tls[, $tls_ctx])
1330		1919
1331	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1920	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1332	object is created, you can also do that at a later time by calling	1921	object is created, you can also do that at a later time by calling
1333	C<starttls>.	1922	C<starttls>.
1334		1923
		1924	Starting TLS is currently an asynchronous operation - when you push some
		1925	write data and then call C<< ->starttls >> then TLS negotiation will start
		1926	immediately, after which the queued write data is then sent.
		1927
1335	The first argument is the same as the C<tls> constructor argument (either	1928	The first argument is the same as the C<tls> constructor argument (either
1336	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1929	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1337		1930
1338	The second argument is the optional C<Net::SSLeay::CTX> object that is	1931	The second argument is the optional C<AnyEvent::TLS> object that is used
1339	used when AnyEvent::Handle has to create its own TLS connection object.	1932	when AnyEvent::Handle has to create its own TLS connection object, or
		1933	a hash reference with C<< key => value >> pairs that will be used to
		1934	construct a new context.
1340		1935
1341	The TLS connection object will end up in C<< $handle->{tls} >> after this	1936	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1342	call and can be used or changed to your liking. Note that the handshake	1937	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1343	might have already started when this function returns.	1938	changed to your liking. Note that the handshake might have already started
		1939	when this function returns.
1344		1940
		1941	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1942	handshakes on the same stream. It is best to not attempt to use the
		1943	stream after stopping TLS.
		1944
		1945	This method may invoke callbacks (and therefore the handle might be
		1946	destroyed after it returns).
		1947
1345	=cut	1948	=cut
		1949
		1950	our %TLS_CACHE; #TODO not yet documented, should we?
1346		1951
1347	sub starttls {	1952	sub starttls {
1348	my ($self, $ssl, $ctx) = @_;	1953	my ($self, $tls, $ctx) = @_;
1349		1954
1350	$self->stoptls;	1955	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1956	if $self->{tls};
1351		1957
1352	if ($ssl eq "accept") {	1958	$self->{tls} = $tls;
1353	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1959	$self->{tls_ctx} = $ctx if @_ > 2;
1354	Net::SSLeay::set_accept_state ($ssl);	1960
1355	} elsif ($ssl eq "connect") {	1961	return unless $self->{fh};
1356	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1962
1357	Net::SSLeay::set_connect_state ($ssl);	1963	require Net::SSLeay;
		1964
		1965	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1966	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1967
		1968	$tls = delete $self->{tls};
		1969	$ctx = $self->{tls_ctx};
		1970
		1971	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1972
		1973	if ("HASH" eq ref $ctx) {
		1974	require AnyEvent::TLS;
		1975
		1976	if ($ctx->{cache}) {
		1977	my $key = $ctx+0;
		1978	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1979	} else {
		1980	$ctx = new AnyEvent::TLS %$ctx;
		1981	}
		1982	}
1358	}	1983
1359		1984	$self->{tls_ctx} = $ctx || TLS_CTX ();
1360	$self->{tls} = $ssl;	1985	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1361		1986
1362	# basically, this is deep magic (because SSL_read should have the same issues)	1987	# basically, this is deep magic (because SSL_read should have the same issues)
1363	# but the openssl maintainers basically said: "trust us, it just works".	1988	# but the openssl maintainers basically said: "trust us, it just works".
1364	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1989	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1365	# and mismaintained ssleay-module doesn't even offer them).	1990	# and mismaintained ssleay-module doesn't even offer them).
1366	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1991	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1992	#
		1993	# in short: this is a mess.
		1994	#
		1995	# note that we do not try to keep the length constant between writes as we are required to do.
		1996	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1997	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1998	# have identity issues in that area.
1367	Net::SSLeay::CTX_set_mode ($self->{tls},	1999	# Net::SSLeay::CTX_set_mode ($ssl,
1368	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2000	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1369	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2001	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2002	Net::SSLeay::CTX_set_mode ($tls, 1|2);
1370		2003
1371	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2004	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2005	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1373		2006
		2007	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		2008
1374	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2009	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1375		2010
1376	$self->{filter_w} = sub {	2011	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1377	$_[0]{_tls_wbuf} .= ${$_[1]};	2012	if $self->{on_starttls};
1378	&_dotls;	2013
1379	};	2014	&_dotls; # need to trigger the initial handshake
1380	$self->{filter_r} = sub {	2015	$self->start_read; # make sure we actually do read
1381	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1382	&_dotls;
1383	};
1384	}	2016	}
1385		2017
1386	=item $handle->stoptls	2018	=item $handle->stoptls
1387		2019
1388	Destroys the SSL connection, if any. Partial read or write data will be	2020	Shuts down the SSL connection - this makes a proper EOF handshake by
1389	lost.	2021	sending a close notify to the other side, but since OpenSSL doesn't
		2022	support non-blocking shut downs, it is not guaranteed that you can re-use
		2023	the stream afterwards.
		2024
		2025	This method may invoke callbacks (and therefore the handle might be
		2026	destroyed after it returns).
1390		2027
1391	=cut	2028	=cut
1392		2029
1393	sub stoptls {	2030	sub stoptls {
1394	my ($self) = @_;	2031	my ($self) = @_;
1395		2032
1396	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2033	if ($self->{tls} && $self->{fh}) {
		2034	Net::SSLeay::shutdown ($self->{tls});
1397		2035
1398	delete $self->{_rbio};	2036	&_dotls;
1399	delete $self->{_wbio};	2037
1400	delete $self->{_tls_wbuf};	2038	# # we don't give a shit. no, we do, but we can't. no...#d#
1401	delete $self->{filter_r};	2039	# # we, we... have to use openssl :/#d#
1402	delete $self->{filter_w};	2040	# &_freetls;#d#
		2041	}
		2042	}
		2043
		2044	sub _freetls {
		2045	my ($self) = @_;
		2046
		2047	return unless $self->{tls};
		2048
		2049	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2050	if $self->{tls} > 0;
		2051
		2052	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1403	}	2053	}
1404		2054
1405	sub DESTROY {	2055	sub DESTROY {
1406	my $self = shift;	2056	my ($self) = @_;
1407		2057
1408	$self->stoptls;	2058	&_freetls;
1409		2059
1410	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2060	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1411		2061
1412	if ($linger && length $self->{wbuf}) {	2062	if ($linger && length $self->{wbuf} && $self->{fh}) {
1413	my $fh = delete $self->{fh};	2063	my $fh = delete $self->{fh};
1414	my $wbuf = delete $self->{wbuf};	2064	my $wbuf = delete $self->{wbuf};
1415		2065
1416	my @linger;	2066	my @linger;
1417		2067
1418	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2068	push @linger, AE::io $fh, 1, sub {
1419	my $len = syswrite $fh, $wbuf, length $wbuf;	2069	my $len = syswrite $fh, $wbuf, length $wbuf;
1420		2070
1421	if ($len > 0) {	2071	if ($len > 0) {
1422	substr $wbuf, 0, $len, "";	2072	substr $wbuf, 0, $len, "";
1423	} else {	2073	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1424	@linger = (); # end	2074	@linger = (); # end
1425	}	2075	}
		2076	};
		2077	push @linger, AE::timer $linger, 0, sub {
		2078	@linger = ();
		2079	};
		2080	}
		2081	}
		2082
		2083	=item $handle->destroy
		2084
		2085	Shuts down the handle object as much as possible - this call ensures that
		2086	no further callbacks will be invoked and as many resources as possible
		2087	will be freed. Any method you will call on the handle object after
		2088	destroying it in this way will be silently ignored (and it will return the
		2089	empty list).
		2090
		2091	Normally, you can just "forget" any references to an AnyEvent::Handle
		2092	object and it will simply shut down. This works in fatal error and EOF
		2093	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2094	callback, so when you want to destroy the AnyEvent::Handle object from
		2095	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2096	that case.
		2097
		2098	Destroying the handle object in this way has the advantage that callbacks
		2099	will be removed as well, so if those are the only reference holders (as
		2100	is common), then one doesn't need to do anything special to break any
		2101	reference cycles.
		2102
		2103	The handle might still linger in the background and write out remaining
		2104	data, as specified by the C<linger> option, however.
		2105
		2106	=cut
		2107
		2108	sub destroy {
		2109	my ($self) = @_;
		2110
		2111	$self->DESTROY;
		2112	%$self = ();
		2113	bless $self, "AnyEvent::Handle::destroyed";
		2114	}
		2115
		2116	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2117	#nop
		2118	}
		2119
		2120	=item $handle->destroyed
		2121
		2122	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2123	->destroy >>, true otherwise.
		2124
		2125	Can be useful to decide whether the handle is still valid after some
		2126	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2127	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2128	can destroy the handle, so work can be avoided by checking sometimes:
		2129
		2130	$hdl->starttls ("accept");
		2131	return if $hdl->destroyed;
		2132	$hdl->push_write (...
		2133
		2134	Note that the call to C<push_write> will silently be ignored if the handle
		2135	has been destroyed, so often you can just ignore the possibility of the
		2136	handle being destroyed.
		2137
		2138	=cut
		2139
		2140	sub destroyed { 0 }
		2141	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2142
		2143	=item AnyEvent::Handle::TLS_CTX
		2144
		2145	This function creates and returns the AnyEvent::TLS object used by default
		2146	for TLS mode.
		2147
		2148	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2149
		2150	=cut
		2151
		2152	our $TLS_CTX;
		2153
		2154	sub TLS_CTX() {
		2155	$TLS_CTX ||= do {
		2156	require AnyEvent::TLS;
		2157
		2158	new AnyEvent::TLS
		2159	}
		2160	}
		2161
		2162	=back
		2163
		2164
		2165	=head1 NONFREQUENTLY ASKED QUESTIONS
		2166
		2167	=over 4
		2168
		2169	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2170	still get further invocations!
		2171
		2172	That's because AnyEvent::Handle keeps a reference to itself when handling
		2173	read or write callbacks.
		2174
		2175	It is only safe to "forget" the reference inside EOF or error callbacks,
		2176	from within all other callbacks, you need to explicitly call the C<<
		2177	->destroy >> method.
		2178
		2179	=item Why is my C<on_eof> callback never called?
		2180
		2181	Probably because your C<on_error> callback is being called instead: When
		2182	you have outstanding requests in your read queue, then an EOF is
		2183	considered an error as you clearly expected some data.
		2184
		2185	To avoid this, make sure you have an empty read queue whenever your handle
		2186	is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
		2187	an C<on_read> handler that simply pushes the first read requests in the
		2188	queue.
		2189
		2190	See also the next question, which explains this in a bit more detail.
		2191
		2192	=item How can I serve requests in a loop?
		2193
		2194	Most protocols consist of some setup phase (authentication for example)
		2195	followed by a request handling phase, where the server waits for requests
		2196	and handles them, in a loop.
		2197
		2198	There are two important variants: The first (traditional, better) variant
		2199	handles requests until the server gets some QUIT command, causing it to
		2200	close the connection first (highly desirable for a busy TCP server). A
		2201	client dropping the connection is an error, which means this variant can
		2202	detect an unexpected detection close.
		2203
		2204	To handle this case, always make sure you have a on-empty read queue, by
		2205	pushing the "read request start" handler on it:
		2206
		2207	# we assume a request starts with a single line
		2208	my @start_request; @start_request = (line => sub {
		2209	my ($hdl, $line) = @_;
		2210
		2211	... handle request
		2212
		2213	# push next request read, possibly from a nested callback
		2214	$hdl->push_read (@start_request);
		2215	});
		2216
		2217	# auth done, now go into request handling loop
		2218	# now push the first @start_request
		2219	$hdl->push_read (@start_request);
		2220
		2221	By always having an outstanding C<push_read>, the handle always expects
		2222	some data and raises the C<EPIPE> error when the connction is dropped
		2223	unexpectedly.
		2224
		2225	The second variant is a protocol where the client can drop the connection
		2226	at any time. For TCP, this means that the server machine may run out of
		2227	sockets easier, and in general, it means you cnanot distinguish a protocl
		2228	failure/client crash from a normal connection close. Nevertheless, these
		2229	kinds of protocols are common (and sometimes even the best solution to the
		2230	problem).
		2231
		2232	Having an outstanding read request at all times is possible if you ignore
		2233	C<EPIPE> errors, but this doesn't help with when the client drops the
		2234	connection during a request, which would still be an error.
		2235
		2236	A better solution is to push the initial request read in an C<on_read>
		2237	callback. This avoids an error, as when the server doesn't expect data
		2238	(i.e. is idly waiting for the next request, an EOF will not raise an
		2239	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2240	and simpler:
		2241
		2242	# auth done, now go into request handling loop
		2243	$hdl->on_read (sub {
		2244	my ($hdl) = @_;
		2245
		2246	# called each time we receive data but the read queue is empty
		2247	# simply start read the request
		2248
		2249	$hdl->push_read (line => sub {
		2250	my ($hdl, $line) = @_;
		2251
		2252	... handle request
		2253
		2254	# do nothing special when the request has been handled, just
		2255	# let the request queue go empty.
1426	});	2256	});
1427	push @linger, AnyEvent->timer (after => $linger, cb => sub {
1428	@linger = ();
1429	});	2257	});
		2258
		2259	=item I get different callback invocations in TLS mode/Why can't I pause
		2260	reading?
		2261
		2262	Unlike, say, TCP, TLS connections do not consist of two independent
		2263	communication channels, one for each direction. Or put differently, the
		2264	read and write directions are not independent of each other: you cannot
		2265	write data unless you are also prepared to read, and vice versa.
		2266
		2267	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2268	callback invocations when you are not expecting any read data - the reason
		2269	is that AnyEvent::Handle always reads in TLS mode.
		2270
		2271	During the connection, you have to make sure that you always have a
		2272	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2273	connection (or when you no longer want to use it) you can call the
		2274	C<destroy> method.
		2275
		2276	=item How do I read data until the other side closes the connection?
		2277
		2278	If you just want to read your data into a perl scalar, the easiest way
		2279	to achieve this is by setting an C<on_read> callback that does nothing,
		2280	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2281	will be in C<$_[0]{rbuf}>:
		2282
		2283	$handle->on_read (sub { });
		2284	$handle->on_eof (undef);
		2285	$handle->on_error (sub {
		2286	my $data = delete $_[0]{rbuf};
		2287	});
		2288
		2289	The reason to use C<on_error> is that TCP connections, due to latencies
		2290	and packets loss, might get closed quite violently with an error, when in
		2291	fact all data has been received.
		2292
		2293	It is usually better to use acknowledgements when transferring data,
		2294	to make sure the other side hasn't just died and you got the data
		2295	intact. This is also one reason why so many internet protocols have an
		2296	explicit QUIT command.
		2297
		2298	=item I don't want to destroy the handle too early - how do I wait until
		2299	all data has been written?
		2300
		2301	After writing your last bits of data, set the C<on_drain> callback
		2302	and destroy the handle in there - with the default setting of
		2303	C<low_water_mark> this will be called precisely when all data has been
		2304	written to the socket:
		2305
		2306	$handle->push_write (...);
		2307	$handle->on_drain (sub {
		2308	warn "all data submitted to the kernel\n";
		2309	undef $handle;
		2310	});
		2311
		2312	If you just want to queue some data and then signal EOF to the other side,
		2313	consider using C<< ->push_shutdown >> instead.
		2314
		2315	=item I want to contact a TLS/SSL server, I don't care about security.
		2316
		2317	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2318	connect to it and then create the AnyEvent::Handle with the C<tls>
		2319	parameter:
		2320
		2321	tcp_connect $host, $port, sub {
		2322	my ($fh) = @_;
		2323
		2324	my $handle = new AnyEvent::Handle
		2325	fh => $fh,
		2326	tls => "connect",
		2327	on_error => sub { ... };
		2328
		2329	$handle->push_write (...);
1430	}	2330	};
1431	}
1432		2331
1433	=item AnyEvent::Handle::TLS_CTX	2332	=item I want to contact a TLS/SSL server, I do care about security.
1434		2333
1435	This function creates and returns the Net::SSLeay::CTX object used by	2334	Then you should additionally enable certificate verification, including
1436	default for TLS mode.	2335	peername verification, if the protocol you use supports it (see
		2336	L<AnyEvent::TLS>, C<verify_peername>).
1437		2337
1438	The context is created like this:	2338	E.g. for HTTPS:
1439		2339
1440	Net::SSLeay::load_error_strings;	2340	tcp_connect $host, $port, sub {
1441	Net::SSLeay::SSLeay_add_ssl_algorithms;	2341	my ($fh) = @_;
1442	Net::SSLeay::randomize;
1443		2342
1444	my $CTX = Net::SSLeay::CTX_new;	2343	my $handle = new AnyEvent::Handle
		2344	fh => $fh,
		2345	peername => $host,
		2346	tls => "connect",
		2347	tls_ctx => { verify => 1, verify_peername => "https" },
		2348	...
1445		2349
1446	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL	2350	Note that you must specify the hostname you connected to (or whatever
		2351	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2352	peername verification will be done.
1447		2353
1448	=cut	2354	The above will use the system-dependent default set of trusted CA
		2355	certificates. If you want to check against a specific CA, add the
		2356	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1449		2357
1450	our $TLS_CTX;	2358	tls_ctx => {
		2359	verify => 1,
		2360	verify_peername => "https",
		2361	ca_file => "my-ca-cert.pem",
		2362	},
1451		2363
1452	sub TLS_CTX() {	2364	=item I want to create a TLS/SSL server, how do I do that?
1453	$TLS_CTX || do {
1454	require Net::SSLeay;
1455		2365
1456	Net::SSLeay::load_error_strings ();	2366	Well, you first need to get a server certificate and key. You have
1457	Net::SSLeay::SSLeay_add_ssl_algorithms ();	2367	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1458	Net::SSLeay::randomize ();	2368	self-signed certificate (cheap. check the search engine of your choice,
		2369	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2370	nice program for that purpose).
1459		2371
1460	$TLS_CTX = Net::SSLeay::CTX_new ();	2372	Then create a file with your private key (in PEM format, see
		2373	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2374	file should then look like this:
1461		2375
1462	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());	2376	-----BEGIN RSA PRIVATE KEY-----
		2377	...header data
		2378	... lots of base64'y-stuff
		2379	-----END RSA PRIVATE KEY-----
1463		2380
1464	$TLS_CTX	2381	-----BEGIN CERTIFICATE-----
1465	}	2382	... lots of base64'y-stuff
1466	}	2383	-----END CERTIFICATE-----
		2384
		2385	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2386	specify this file as C<cert_file>:
		2387
		2388	tcp_server undef, $port, sub {
		2389	my ($fh) = @_;
		2390
		2391	my $handle = new AnyEvent::Handle
		2392	fh => $fh,
		2393	tls => "accept",
		2394	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2395	...
		2396
		2397	When you have intermediate CA certificates that your clients might not
		2398	know about, just append them to the C<cert_file>.
1467		2399
1468	=back	2400	=back
		2401
1469		2402
1470	=head1 SUBCLASSING AnyEvent::Handle	2403	=head1 SUBCLASSING AnyEvent::Handle
1471		2404
1472	In many cases, you might want to subclass AnyEvent::Handle.	2405	In many cases, you might want to subclass AnyEvent::Handle.
1473		2406
…		…
1490		2423
1491	=item * all members not documented here and not prefixed with an underscore	2424	=item * all members not documented here and not prefixed with an underscore
1492	are free to use in subclasses.	2425	are free to use in subclasses.
1493		2426
1494	Of course, new versions of AnyEvent::Handle may introduce more "public"	2427	Of course, new versions of AnyEvent::Handle may introduce more "public"
1495	member variables, but thats just life, at least it is documented.	2428	member variables, but that's just life. At least it is documented.
1496		2429
1497	=back	2430	=back
1498		2431
1499	=head1 AUTHOR	2432	=head1 AUTHOR
1500		2433

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