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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 => $filehandle [C<fh> or C<connect> MANDATORY]
72		93
73	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
74
75	NOTE: The filehandle will be set to non-blocking (using	95	NOTE: The filehandle will be set to non-blocking mode (using
76	AnyEvent::Util::fh_nonblocking).	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
77		98
		99	=item connect => [$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
78	=item on_eof => $cb->($handle)	116	=item on_prepare => $cb->($handle)
79		117
80	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
81	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
82	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).
83		123
84	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
85	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
86	callback and continue writing data, as only the read part has been shut	126	default timeout is to be used).
87	down.
88		127
89	While not mandatory, it is I<highly> recommended to set an eof callback,	128	=item on_connect => $cb->($handle, $host, $port, $retry->())
90	otherwise you might end up with a closed socket while you are still
91	waiting for data.
92		129
93	If an EOF condition has been detected but no C<on_eof> callback has been	130	This callback is called when a connection has been successfully established.
94	set, then a fatal error will be raised with C<$!> set to <0>.
95		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
96	=item on_error => $cb->($handle, $fatal)	154	=item on_error => $cb->($handle, $fatal, $message)
97		155
98	This is the error callback, which is called when, well, some error	156	This is the error callback, which is called when, well, some error
99	occured, such as not being able to resolve the hostname, failure to	157	occured, such as not being able to resolve the hostname, failure to
100	connect or a read error.	158	connect, or a read error.
101		159
102	Some errors are fatal (which is indicated by C<$fatal> being true). On	160	Some errors are fatal (which is indicated by C<$fatal> being true). On
103	fatal errors the handle object will be shut down and will not be usable	161	fatal errors the handle object will be destroyed (by a call to C<< ->
104	(but you are free to look at the current C< ->rbuf >). Examples of fatal	162	destroy >>) after invoking the error callback (which means you are free to
105	errors are an EOF condition with active (but unsatisifable) read watchers	163	examine the handle object). Examples of fatal errors are an EOF condition
106	(C<EPIPE>) or I/O errors.	164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
107		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
108	Non-fatal errors can be retried by simply returning, but it is recommended	173	Non-fatal errors can be retried by returning, but it is recommended
109	to simply ignore this parameter and instead abondon the handle object	174	to simply ignore this parameter and instead abondon the handle object
110	when this callback is invoked. Examples of non-fatal errors are timeouts	175	when this callback is invoked. Examples of non-fatal errors are timeouts
111	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).	176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
112		177
113	On callback entrance, the value of C<$!> contains the operating system	178	On entry to the callback, the value of C<$!> contains the operating
114	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>).
115		181
116	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
117	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
118	C<croak>.	184	C<croak>.
119		185
120	=item on_read => $cb->($handle)	186	=item on_read => $cb->($handle)
121		187
122	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
123	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
124	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
125	read buffer).	191	read buffer).
126		192
127	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 >>
128	method or access the C<$handle->{rbuf}> member directly.	194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
129		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
130	When an EOF condition is detected then AnyEvent::Handle will first try to	201	When an EOF condition is detected, AnyEvent::Handle will first try to
131	feed all the remaining data to the queued callbacks and C<on_read> before	202	feed all the remaining data to the queued callbacks and C<on_read> before
132	calling the C<on_eof> callback. If no progress can be made, then a fatal	203	calling the C<on_eof> callback. If no progress can be made, then a fatal
133	error will be raised (with C<$!> set to C<EPIPE>).	204	error will be raised (with C<$!> set to C<EPIPE>).
134		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
135	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
136		228
137	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
138	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
139		231
140	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.
141		233
142	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
143	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
…		…
145	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
146	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
147		239
148	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
149		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
150	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
151	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
152	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
153	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).
154		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
155	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
156	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
157	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
158	in the C<on_timeout> callback.	261	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		262	restart the timeout.
159		263
160	Zero (the default) disables this timeout.	264	Zero (the default) disables this timeout.
161		265
162	=item on_timeout => $cb->($handle)	266	=item on_timeout => $cb->($handle)
163		267
…		…
167		271
168	=item rbuf_max => <bytes>	272	=item rbuf_max => <bytes>
169		273
170	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>)
171	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
172	avoid denial-of-service attacks.	276	avoid some forms of denial-of-service attacks.
173		277
174	For example, a server accepting connections from untrusted sources should	278	For example, a server accepting connections from untrusted sources should
175	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
176	(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
177	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
178	isn't finished).	282	isn't finished).
179		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
180	=item autocork => <boolean>	299	=item autocork => <boolean>
181		300
182	When disabled (the default), then C<push_write> will try to immediately	301	When disabled (the default), C<push_write> will try to immediately
183	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
184	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
185	inefficient if you write multiple small chunks (this disadvantage is	304	be inefficient if you write multiple small chunks (on the wire, this
186	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).
187		307
188	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
189	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,
190	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.
191		312
192	=item no_delay => <boolean>	313	=item no_delay => <boolean>
193		314
194	When doing small writes on sockets, your operating system kernel might	315	When doing small writes on sockets, your operating system kernel might
195	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
196	the Nagle algorithm, and usually it is beneficial.	317	the Nagle algorithm, and usually it is beneficial.
197		318
198	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
199	accomplishd by setting this option to true.	320	accomplishd by setting this option to a true value.
200		321
201	The default is your opertaing system's default behaviour, this option	322	The default is your operating system's default behaviour (most likely
202	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.
203		356
204	=item read_size => <bytes>	357	=item read_size => <bytes>
205		358
206	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
207	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.
208		370
209	=item low_water_mark => <bytes>	371	=item low_water_mark => <bytes>
210		372
211	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
212	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
213	considered empty.	375	considered empty.
214		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
215	=item linger => <seconds>	382	=item linger => <seconds>
216		383
217	If non-zero (default: C<3600>), then the destructor of the	384	If this is non-zero (default: C<3600>), the destructor of the
218	AnyEvent::Handle object will check wether there is still outstanding write	385	AnyEvent::Handle object will check whether there is still outstanding
219	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
220	will be reported (this mostly matches how the operating system treats	387	socket. No errors will be reported (this mostly matches how the operating
221	outstanding data at socket close time).	388	system treats outstanding data at socket close time).
222		389
223	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
224	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>.
225		403
226	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	404	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
227		405
228	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
229	will start making tls handshake and will transparently encrypt/decrypt	407	AnyEvent will start a TLS handshake as soon as the connection has been
230	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.
231		412
232	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
233	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.
234		417
235	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
236	connection, use C<connect> mode.	419	C<accept>, and for the TLS client side of a connection, use C<connect>
		420	mode.
237		421
238	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
239	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>
240	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
241	AnyEvent::Handle.	425	AnyEvent::Handle. Also, this module will take ownership of this connection
		426	object.
242		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
243	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.
244		438
245	=item tls_ctx => $ssl_ctx	439	=item tls_ctx => $anyevent_tls
246		440
247	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
248	(unless a connection object was specified directly). If this parameter is	442	(unless a connection object was specified directly). If this
249	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.
250		481
251	=item json => JSON or JSON::XS object	482	=item json => JSON or JSON::XS object
252		483
253	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.
254		485
255	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
256	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.
257		489
258	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
259	use this functionality, as AnyEvent does not have a dependency itself.	491	use this functionality, as AnyEvent does not have a dependency itself.
260		492
261	=item filter_r => $cb
262
263	=item filter_w => $cb
264
265	These exist, but are undocumented at this time.
266
267	=back	493	=back
268		494
269	=cut	495	=cut
270		496
271	sub new {	497	sub new {
272	my $class = shift;	498	my $class = shift;
273
274	my $self = bless { @_ }, $class;	499	my $self = bless { @_ }, $class;
275		500
276	$self->{fh} or Carp::croak "mandatory argument fh is missing";	501	if ($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;
277		572
278	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	573	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
279		574
280	if ($self->{tls}) {	575	$self->{_activity} =
281	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
282	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	592	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
283	}	593	if $self->{tls};
284		594
285	$self->{_activity} = AnyEvent->now;
286	$self->_timeout;
287
288	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	595	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
289	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
290		596
291	$self->start_read	597	$self->start_read
292	if $self->{on_read};	598	if $self->{on_read} || @{ $self->{_queue} };
293		599
294	$self	600	$self->_drain_wbuf;
295	}
296
297	sub _shutdown {
298	my ($self) = @_;
299
300	delete $self->{_tw};
301	delete $self->{_rw};
302	delete $self->{_ww};
303	delete $self->{fh};
304
305	$self->stoptls;
306
307	delete $self->{on_read};
308	delete $self->{_queue};
309	}	601	}
310		602
311	sub _error {	603	sub _error {
312	my ($self, $errno, $fatal) = @_;	604	my ($self, $errno, $fatal, $message) = @_;
313
314	$self->_shutdown
315	if $fatal;
316		605
317	$! = $errno;	606	$! = $errno;
		607	$message ||= "$!";
318		608
319	if ($self->{on_error}) {	609	if ($self->{on_error}) {
320	$self->{on_error}($self, $fatal);	610	$self->{on_error}($self, $fatal, $message);
321	} else {	611	$self->destroy if $fatal;
		612	} elsif ($self->{fh} || $self->{connect}) {
		613	$self->destroy;
322	Carp::croak "AnyEvent::Handle uncaught error: $!";	614	Carp::croak "AnyEvent::Handle uncaught error: $message";
323	}	615	}
324	}	616	}
325		617
326	=item $fh = $handle->fh	618	=item $fh = $handle->fh
327		619
328	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.
329		621
330	=cut	622	=cut
331		623
332	sub fh { $_[0]{fh} }	624	sub fh { $_[0]{fh} }
333		625
…		…
351	$_[0]{on_eof} = $_[1];	643	$_[0]{on_eof} = $_[1];
352	}	644	}
353		645
354	=item $handle->on_timeout ($cb)	646	=item $handle->on_timeout ($cb)
355		647
356	Replace the current C<on_timeout> callback, or disables the callback	648	=item $handle->on_rtimeout ($cb)
357	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
358	argument.
359		649
360	=cut	650	=item $handle->on_wtimeout ($cb)
361		651
362	sub on_timeout {	652	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
363	$_[0]{on_timeout} = $_[1];	653	callback, or disables the callback (but not the timeout) if C<$cb> =
364	}	654	C<undef>. See the C<timeout> constructor argument and method.
		655
		656	=cut
		657
		658	# see below
365		659
366	=item $handle->autocork ($boolean)	660	=item $handle->autocork ($boolean)
367		661
368	Enables or disables the current autocork behaviour (see C<autocork>	662	Enables or disables the current autocork behaviour (see C<autocork>
369	constructor argument).	663	constructor argument). Changes will only take effect on the next write.
370		664
371	=cut	665	=cut
		666
		667	sub autocork {
		668	$_[0]{autocork} = $_[1];
		669	}
372		670
373	=item $handle->no_delay ($boolean)	671	=item $handle->no_delay ($boolean)
374		672
375	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
376	the same name for details).	674	the same name for details).
…		…
378	=cut	676	=cut
379		677
380	sub no_delay {	678	sub no_delay {
381	$_[0]{no_delay} = $_[1];	679	$_[0]{no_delay} = $_[1];
382		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
383	eval {	695	eval {
384	local $SIG{__DIE__};	696	local $SIG{__DIE__};
385	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};
386	};	699	};
387	}	700	}
388		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
389	#############################################################################	774	#############################################################################
390		775
391	=item $handle->timeout ($seconds)	776	=item $handle->timeout ($seconds)
392		777
		778	=item $handle->rtimeout ($seconds)
		779
		780	=item $handle->wtimeout ($seconds)
		781
393	Configures (or disables) the inactivity timeout.	782	Configures (or disables) the inactivity timeout.
394		783
395	=cut	784	=item $handle->timeout_reset
396		785
397	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 {
398	my ($self, $timeout) = @_;	808	my ($self, $new_value) = @_;
399		809
		810	$new_value >= 0
		811	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		812
400	$self->{timeout} = $timeout;	813	$self->{$timeout} = $new_value;
401	$self->_timeout;	814	delete $self->{$tw}; &$cb;
402	}	815	};
403		816
		817	*{"${dir}timeout_reset"} = sub {
		818	$_[0]{$activity} = AE::now;
		819	};
		820
		821	# main workhorse:
404	# reset the timeout watcher, as neccessary	822	# reset the timeout watcher, as neccessary
405	# also check for time-outs	823	# also check for time-outs
406	sub _timeout {	824	$cb = sub {
407	my ($self) = @_;	825	my ($self) = @_;
408		826
409	if ($self->{timeout}) {	827	if ($self->{$timeout} && $self->{fh}) {
410	my $NOW = AnyEvent->now;	828	my $NOW = AE::now;
411		829
412	# when would the timeout trigger?	830	# when would the timeout trigger?
413	my $after = $self->{_activity} + $self->{timeout} - $NOW;	831	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
414		832
415	# now or in the past already?	833	# now or in the past already?
416	if ($after <= 0) {	834	if ($after <= 0) {
417	$self->{_activity} = $NOW;	835	$self->{$activity} = $NOW;
418		836
419	if ($self->{on_timeout}) {	837	if ($self->{$on_timeout}) {
420	$self->{on_timeout}($self);	838	$self->{$on_timeout}($self);
421	} else {	839	} else {
422	$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};
423	}	848	}
424		849
425	# callback could have changed timeout value, optimise	850	Scalar::Util::weaken $self;
426	return unless $self->{timeout};	851	return unless $self; # ->error could have destroyed $self
427		852
428	# calculate new after	853	$self->{$tw} ||= AE::timer $after, 0, sub {
429	$after = $self->{timeout};	854	delete $self->{$tw};
		855	$cb->($self);
		856	};
		857	} else {
		858	delete $self->{$tw};
430	}	859	}
431
432	Scalar::Util::weaken $self;
433	return unless $self; # ->error could have destroyed $self
434
435	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
436	delete $self->{_tw};
437	$self->_timeout;
438	});
439	} else {
440	delete $self->{_tw};
441	}	860	}
442	}	861	}
443		862
444	#############################################################################	863	#############################################################################
445		864
…		…
461	=item $handle->on_drain ($cb)	880	=item $handle->on_drain ($cb)
462		881
463	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
464	C<on_drain> in the constructor).	883	C<on_drain> in the constructor).
465		884
		885	This method may invoke callbacks (and therefore the handle might be
		886	destroyed after it returns).
		887
466	=cut	888	=cut
467		889
468	sub on_drain {	890	sub on_drain {
469	my ($self, $cb) = @_;	891	my ($self, $cb) = @_;
470		892
471	$self->{on_drain} = $cb;	893	$self->{on_drain} = $cb;
472		894
473	$cb->($self)	895	$cb->($self)
474	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	896	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
475	}	897	}
476		898
477	=item $handle->push_write ($data)	899	=item $handle->push_write ($data)
478		900
479	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
480	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
481	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).
482		907
483	=cut	908	=cut
484		909
485	sub _drain_wbuf {	910	sub _drain_wbuf {
486	my ($self) = @_;	911	my ($self) = @_;
…		…
490	Scalar::Util::weaken $self;	915	Scalar::Util::weaken $self;
491		916
492	my $cb = sub {	917	my $cb = sub {
493	my $len = syswrite $self->{fh}, $self->{wbuf};	918	my $len = syswrite $self->{fh}, $self->{wbuf};
494		919
495	if ($len >= 0) {	920	if (defined $len) {
496	substr $self->{wbuf}, 0, $len, "";	921	substr $self->{wbuf}, 0, $len, "";
497		922
498	$self->{_activity} = AnyEvent->now;	923	$self->{_activity} = $self->{_wactivity} = AE::now;
499		924
500	$self->{on_drain}($self)	925	$self->{on_drain}($self)
501	if $self->{low_water_mark} >= length $self->{wbuf}	926	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
502	&& $self->{on_drain};	927	&& $self->{on_drain};
503		928
504	delete $self->{_ww} unless length $self->{wbuf};	929	delete $self->{_ww} unless length $self->{wbuf};
505	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	930	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
506	$self->_error ($!, 1);	931	$self->_error ($!, 1);
…		…
509		934
510	# try to write data immediately	935	# try to write data immediately
511	$cb->() unless $self->{autocork};	936	$cb->() unless $self->{autocork};
512		937
513	# if still data left in wbuf, we need to poll	938	# if still data left in wbuf, we need to poll
514	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	939	$self->{_ww} = AE::io $self->{fh}, 1, $cb
515	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	}
516	};	948	};
517	}	949	}
518		950
519	our %WH;	951	our %WH;
520		952
		953	# deprecated
521	sub register_write_type($$) {	954	sub register_write_type($$) {
522	$WH{$_[0]} = $_[1];	955	$WH{$_[0]} = $_[1];
523	}	956	}
524		957
525	sub push_write {	958	sub push_write {
526	my $self = shift;	959	my $self = shift;
527		960
528	if (@_ > 1) {	961	if (@_ > 1) {
529	my $type = shift;	962	my $type = shift;
530		963
		964	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
531	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	965	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
532	->($self, @_);	966	->($self, @_);
533	}	967	}
534		968
		969	# we downgrade here to avoid hard-to-track-down bugs,
		970	# and diagnose the problem earlier and better.
		971
535	if ($self->{filter_w}) {	972	if ($self->{tls}) {
536	$self->{filter_w}($self, \$_[0]);	973	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		974	&_dotls ($self) if $self->{fh};
537	} else {	975	} else {
538	$self->{wbuf} .= $_[0];	976	utf8::downgrade $self->{wbuf} .= $_[0];
539	$self->_drain_wbuf;	977	$self->_drain_wbuf if $self->{fh};
540	}	978	}
541	}	979	}
542		980
543	=item $handle->push_write (type => @args)	981	=item $handle->push_write (type => @args)
544		982
545	Instead of formatting your data yourself, you can also let this module do	983	Instead of formatting your data yourself, you can also let this module
546	the job by specifying a type and type-specific arguments.	984	do the job by specifying a type and type-specific arguments. You
		985	can also specify the (fully qualified) name of a package, in which
		986	case AnyEvent tries to load the package and then expects to find the
		987	C<anyevent_write_type> function inside (see "custom write types", below).
547		988
548	Predefined types are (if you have ideas for additional types, feel free to	989	Predefined types are (if you have ideas for additional types, feel free to
549	drop by and tell us):	990	drop by and tell us):
550		991
551	=over 4	992	=over 4
…		…
558	=cut	999	=cut
559		1000
560	register_write_type netstring => sub {	1001	register_write_type netstring => sub {
561	my ($self, $string) = @_;	1002	my ($self, $string) = @_;
562		1003
563	sprintf "%d:%s,", (length $string), $string	1004	(length $string) . ":$string,"
564	};	1005	};
565		1006
566	=item packstring => $format, $data	1007	=item packstring => $format, $data
567		1008
568	An octet string prefixed with an encoded length. The encoding C<$format>	1009	An octet string prefixed with an encoded length. The encoding C<$format>
…		…
608	Other languages could read single lines terminated by a newline and pass	1049	Other languages could read single lines terminated by a newline and pass
609	this line into their JSON decoder of choice.	1050	this line into their JSON decoder of choice.
610		1051
611	=cut	1052	=cut
612		1053
		1054	sub json_coder() {
		1055	eval { require JSON::XS; JSON::XS->new->utf8 }
		1056	|| do { require JSON; JSON->new->utf8 }
		1057	}
		1058
613	register_write_type json => sub {	1059	register_write_type json => sub {
614	my ($self, $ref) = @_;	1060	my ($self, $ref) = @_;
615		1061
616	require JSON;	1062	my $json = $self->{json} ||= json_coder;
617		1063
618	$self->{json} ? $self->{json}->encode ($ref)	1064	$json->encode ($ref)
619	: JSON::encode_json ($ref)
620	};	1065	};
621		1066
622	=item storable => $reference	1067	=item storable => $reference
623		1068
624	Freezes the given reference using L<Storable> and writes it to the	1069	Freezes the given reference using L<Storable> and writes it to the
…		…
634	pack "w/a*", Storable::nfreeze ($ref)	1079	pack "w/a*", Storable::nfreeze ($ref)
635	};	1080	};
636		1081
637	=back	1082	=back
638		1083
639	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1084	=item $handle->push_shutdown
640		1085
641	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
642	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
643	reference with the handle object and the remaining arguments.	1121	the handle object and the remaining arguments.
644		1122
645	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
646	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.
647		1126
648	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
649	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	}
650		1143
651	=cut	1144	=cut
652		1145
653	#############################################################################	1146	#############################################################################
654		1147
…		…
663	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
664	a queue.	1157	a queue.
665		1158
666	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
667	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
668	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1161	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
669	leave the data there if you want to accumulate more (e.g. when only a	1162	leave the data there if you want to accumulate more (e.g. when only a
670	partial message has been received so far).	1163	partial message has been received so far), or change the read queue with
		1164	e.g. C<push_read>.
671		1165
672	In the more complex case, you want to queue multiple callbacks. In this	1166	In the more complex case, you want to queue multiple callbacks. In this
673	case, AnyEvent::Handle will call the first queued callback each time new	1167	case, AnyEvent::Handle will call the first queued callback each time new
674	data arrives (also the first time it is queued) and removes it when it has	1168	data arrives (also the first time it is queued) and remove it when it has
675	done its job (see C<push_read>, below).	1169	done its job (see C<push_read>, below).
676		1170
677	This way you can, for example, push three line-reads, followed by reading	1171	This way you can, for example, push three line-reads, followed by reading
678	a chunk of data, and AnyEvent::Handle will execute them in order.	1172	a chunk of data, and AnyEvent::Handle will execute them in order.
679		1173
…		…
736	=cut	1230	=cut
737		1231
738	sub _drain_rbuf {	1232	sub _drain_rbuf {
739	my ($self) = @_;	1233	my ($self) = @_;
740		1234
		1235	# avoid recursion
		1236	return if $self->{_skip_drain_rbuf};
741	local $self->{_in_drain} = 1;	1237	local $self->{_skip_drain_rbuf} = 1;
742
743	if (
744	defined $self->{rbuf_max}
745	&& $self->{rbuf_max} < length $self->{rbuf}
746	) {
747	$self->_error (&Errno::ENOSPC, 1), return;
748	}
749		1238
750	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
751	my $len = length $self->{rbuf};	1245	my $len = length $self->{rbuf};
752		1246
753	if (my $cb = shift @{ $self->{_queue} }) {	1247	if (my $cb = shift @{ $self->{_queue} }) {
754	unless ($cb->($self)) {	1248	unless ($cb->($self)) {
755	if ($self->{_eof}) {	1249	# no progress can be made
756	# no progress can be made (not enough data and no data forthcoming)	1250	# (not enough data and no data forthcoming)
757	$self->_error (&Errno::EPIPE, 1), return;	1251	$self->_error (Errno::EPIPE, 1), return
758	}	1252	if $self->{_eof};
759		1253
760	unshift @{ $self->{_queue} }, $cb;	1254	unshift @{ $self->{_queue} }, $cb;
761	last;	1255	last;
762	}	1256	}
763	} elsif ($self->{on_read}) {	1257	} elsif ($self->{on_read}) {
…		…
770	&& !@{ $self->{_queue} } # and the queue is still empty	1264	&& !@{ $self->{_queue} } # and the queue is still empty
771	&& $self->{on_read} # but we still have on_read	1265	&& $self->{on_read} # but we still have on_read
772	) {	1266	) {
773	# no further data will arrive	1267	# no further data will arrive
774	# so no progress can be made	1268	# so no progress can be made
775	$self->_error (&Errno::EPIPE, 1), return	1269	$self->_error (Errno::EPIPE, 1), return
776	if $self->{_eof};	1270	if $self->{_eof};
777		1271
778	last; # more data might arrive	1272	last; # more data might arrive
779	}	1273	}
780	} else {	1274	} else {
781	# read side becomes idle	1275	# read side becomes idle
782	delete $self->{_rw};	1276	delete $self->{_rw} unless $self->{tls};
783	last;	1277	last;
784	}	1278	}
785	}	1279	}
786		1280
787	if ($self->{_eof}) {	1281	if ($self->{_eof}) {
788	if ($self->{on_eof}) {	1282	$self->{on_eof}
789	$self->{on_eof}($self)	1283	? $self->{on_eof}($self)
790	} else {	1284	: $self->_error (0, 1, "Unexpected end-of-file");
791	$self->_error (0, 1);	1285
792	}	1286	return;
		1287	}
		1288
		1289	if (
		1290	defined $self->{rbuf_max}
		1291	&& $self->{rbuf_max} < length $self->{rbuf}
		1292	) {
		1293	$self->_error (Errno::ENOSPC, 1), return;
793	}	1294	}
794		1295
795	# may need to restart read watcher	1296	# may need to restart read watcher
796	unless ($self->{_rw}) {	1297	unless ($self->{_rw}) {
797	$self->start_read	1298	$self->start_read
…		…
803		1304
804	This replaces the currently set C<on_read> callback, or clears it (when	1305	This replaces the currently set C<on_read> callback, or clears it (when
805	the new callback is C<undef>). See the description of C<on_read> in the	1306	the new callback is C<undef>). See the description of C<on_read> in the
806	constructor.	1307	constructor.
807		1308
		1309	This method may invoke callbacks (and therefore the handle might be
		1310	destroyed after it returns).
		1311
808	=cut	1312	=cut
809		1313
810	sub on_read {	1314	sub on_read {
811	my ($self, $cb) = @_;	1315	my ($self, $cb) = @_;
812		1316
813	$self->{on_read} = $cb;	1317	$self->{on_read} = $cb;
814	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1318	$self->_drain_rbuf if $cb;
815	}	1319	}
816		1320
817	=item $handle->rbuf	1321	=item $handle->rbuf
818		1322
819	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).
820		1326
821	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)
822	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.
823		1330
824	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>
825	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
826	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.
827		1335
828	=cut	1336	=cut
829		1337
830	sub rbuf : lvalue {	1338	sub rbuf : lvalue {
831	$_[0]{rbuf}	1339	$_[0]{rbuf}
…		…
848		1356
849	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
850	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
851	true, it will be removed from the queue.	1359	true, it will be removed from the queue.
852		1360
		1361	These methods may invoke callbacks (and therefore the handle might be
		1362	destroyed after it returns).
		1363
853	=cut	1364	=cut
854		1365
855	our %RH;	1366	our %RH;
856		1367
857	sub register_read_type($$) {	1368	sub register_read_type($$) {
…		…
863	my $cb = pop;	1374	my $cb = pop;
864		1375
865	if (@_) {	1376	if (@_) {
866	my $type = shift;	1377	my $type = shift;
867		1378
		1379	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
868	$cb = ($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")
869	->($self, $cb, @_);	1381	->($self, $cb, @_);
870	}	1382	}
871		1383
872	push @{ $self->{_queue} }, $cb;	1384	push @{ $self->{_queue} }, $cb;
873	$self->_drain_rbuf unless $self->{_in_drain};	1385	$self->_drain_rbuf;
874	}	1386	}
875		1387
876	sub unshift_read {	1388	sub unshift_read {
877	my $self = shift;	1389	my $self = shift;
878	my $cb = pop;	1390	my $cb = pop;
879		1391
880	if (@_) {	1392	if (@_) {
881	my $type = shift;	1393	my $type = shift;
882		1394
		1395	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
883	$cb = ($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")
884	->($self, $cb, @_);	1397	->($self, $cb, @_);
885	}	1398	}
886		1399
887
888	unshift @{ $self->{_queue} }, $cb;	1400	unshift @{ $self->{_queue} }, $cb;
889	$self->_drain_rbuf unless $self->{_in_drain};	1401	$self->_drain_rbuf;
890	}	1402	}
891		1403
892	=item $handle->push_read (type => @args, $cb)	1404	=item $handle->push_read (type => @args, $cb)
893		1405
894	=item $handle->unshift_read (type => @args, $cb)	1406	=item $handle->unshift_read (type => @args, $cb)
895		1407
896	Instead of providing a callback that parses the data itself you can chose	1408	Instead of providing a callback that parses the data itself you can chose
897	between a number of predefined parsing formats, for chunks of data, lines	1409	between a number of predefined parsing formats, for chunks of data, lines
898	etc.	1410	etc. You can also specify the (fully qualified) name of a package, in
		1411	which case AnyEvent tries to load the package and then expects to find the
		1412	C<anyevent_read_type> function inside (see "custom read types", below).
899		1413
900	Predefined types are (if you have ideas for additional types, feel free to	1414	Predefined types are (if you have ideas for additional types, feel free to
901	drop by and tell us):	1415	drop by and tell us):
902		1416
903	=over 4	1417	=over 4
…		…
995	the receive buffer when neither C<$accept> nor C<$reject> match,	1509	the receive buffer when neither C<$accept> nor C<$reject> match,
996	and everything preceding and including the match will be accepted	1510	and everything preceding and including the match will be accepted
997	unconditionally. This is useful to skip large amounts of data that you	1511	unconditionally. This is useful to skip large amounts of data that you
998	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1512	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
999	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
1000	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.
1001		1515
1002	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
1003	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
1004	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
1005	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
1006	required for the accept regex.	1520	required for the accept regex.
1007		1521
1008	$handle->push_read (regex =>	1522	$handle->push_read (regex =>
…		…
1027	return 1;	1541	return 1;
1028	}	1542	}
1029		1543
1030	# reject	1544	# reject
1031	if ($reject && $$rbuf =~ $reject) {	1545	if ($reject && $$rbuf =~ $reject) {
1032	$self->_error (&Errno::EBADMSG);	1546	$self->_error (Errno::EBADMSG);
1033	}	1547	}
1034		1548
1035	# skip	1549	# skip
1036	if ($skip && $$rbuf =~ $skip) {	1550	if ($skip && $$rbuf =~ $skip) {
1037	$data .= substr $$rbuf, 0, $+[0], "";	1551	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1053	my ($self, $cb) = @_;	1567	my ($self, $cb) = @_;
1054		1568
1055	sub {	1569	sub {
1056	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1570	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1057	if ($_[0]{rbuf} =~ /[^0-9]/) {	1571	if ($_[0]{rbuf} =~ /[^0-9]/) {
1058	$self->_error (&Errno::EBADMSG);	1572	$self->_error (Errno::EBADMSG);
1059	}	1573	}
1060	return;	1574	return;
1061	}	1575	}
1062		1576
1063	my $len = $1;	1577	my $len = $1;
…		…
1066	my $string = $_[1];	1580	my $string = $_[1];
1067	$_[0]->unshift_read (chunk => 1, sub {	1581	$_[0]->unshift_read (chunk => 1, sub {
1068	if ($_[1] eq ",") {	1582	if ($_[1] eq ",") {
1069	$cb->($_[0], $string);	1583	$cb->($_[0], $string);
1070	} else {	1584	} else {
1071	$self->_error (&Errno::EBADMSG);	1585	$self->_error (Errno::EBADMSG);
1072	}	1586	}
1073	});	1587	});
1074	});	1588	});
1075		1589
1076	1	1590	1
…		…
1082	An octet string prefixed with an encoded length. The encoding C<$format>	1596	An octet string prefixed with an encoded length. The encoding C<$format>
1083	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
1084	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an	1598	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1085	optional C<!>, C<< < >> or C<< > >> modifier).	1599	optional C<!>, C<< < >> or C<< > >> modifier).
1086		1600
1087	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).
1088		1603
1089	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
1090	format (very efficient).	1605	format (very efficient).
1091		1606
1092	$handle->push_read (packstring => "w", sub {	1607	$handle->push_read (packstring => "w", sub {
…		…
1122	}	1637	}
1123	};	1638	};
1124		1639
1125	=item json => $cb->($handle, $hash_or_arrayref)	1640	=item json => $cb->($handle, $hash_or_arrayref)
1126		1641
1127	Reads a JSON object or array, decodes it and passes it to the callback.	1642	Reads a JSON object or array, decodes it and passes it to the
		1643	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1128		1644
1129	If a C<json> object was passed to the constructor, then that will be used	1645	If a C<json> object was passed to the constructor, then that will be used
1130	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1646	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1131		1647
1132	This read type uses the incremental parser available with JSON version	1648	This read type uses the incremental parser available with JSON version
…		…
1141	=cut	1657	=cut
1142		1658
1143	register_read_type json => sub {	1659	register_read_type json => sub {
1144	my ($self, $cb) = @_;	1660	my ($self, $cb) = @_;
1145		1661
1146	require JSON;	1662	my $json = $self->{json} ||= json_coder;
1147		1663
1148	my $data;	1664	my $data;
1149	my $rbuf = \$self->{rbuf};	1665	my $rbuf = \$self->{rbuf};
1150		1666
1151	my $json = $self->{json} ||= JSON->new->utf8;
1152
1153	sub {	1667	sub {
1154	my $ref = $json->incr_parse ($self->{rbuf});	1668	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1155		1669
1156	if ($ref) {	1670	if ($ref) {
1157	$self->{rbuf} = $json->incr_text;	1671	$self->{rbuf} = $json->incr_text;
1158	$json->incr_text = "";	1672	$json->incr_text = "";
1159	$cb->($self, $ref);	1673	$cb->($self, $ref);
1160		1674
1161	1	1675	1
		1676	} elsif ($@) {
		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	()
1162	} else {	1686	} else {
1163	$self->{rbuf} = "";	1687	$self->{rbuf} = "";
		1688
1164	()	1689	()
1165	}	1690	}
1166	}	1691	}
1167	};	1692	};
1168		1693
…		…
1200	# read remaining chunk	1725	# read remaining chunk
1201	$_[0]->unshift_read (chunk => $len, sub {	1726	$_[0]->unshift_read (chunk => $len, sub {
1202	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1727	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1203	$cb->($_[0], $ref);	1728	$cb->($_[0], $ref);
1204	} else {	1729	} else {
1205	$self->_error (&Errno::EBADMSG);	1730	$self->_error (Errno::EBADMSG);
1206	}	1731	}
1207	});	1732	});
1208	}	1733	}
1209		1734
1210	1	1735	1
1211	}	1736	}
1212	};	1737	};
1213		1738
1214	=back	1739	=back
1215		1740
1216	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1741	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1217		1742
1218	This function (not method) lets you add your own types to C<push_read>.	1743	Instead of one of the predefined types, you can also specify the name
		1744	of a package. AnyEvent will try to load the package and then expects to
		1745	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1746	progressively tries to load the parent package until it either finds the
		1747	function (good) or runs out of packages (bad).
1219		1748
1220	Whenever the given C<type> is used, C<push_read> will invoke the code	1749	Whenever this type is used, C<push_read> will invoke the function with the
1221	reference with the handle object, the callback and the remaining	1750	handle object, the original callback and the remaining arguments.
1222	arguments.
1223		1751
1224	The code reference is supposed to return a callback (usually a closure)	1752	The function is supposed to return a callback (usually a closure) that
1225	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1753	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1754	mentally treat the function as a "configurable read type to read callback"
		1755	converter.
1226		1756
1227	It should invoke the passed callback when it is done reading (remember to	1757	It should invoke the original callback when it is done reading (remember
1228	pass C<$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).
1229		1760
1230	Note that this is a function, and all types registered this way will be
1231	global, so try to use unique names.
1232
1233	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
1234	search for C<register_read_type>)).	1762	AnyEvent::Handle>, search for C<register_read_type>)).
1235		1763
1236	=item $handle->stop_read	1764	=item $handle->stop_read
1237		1765
1238	=item $handle->start_read	1766	=item $handle->start_read
1239		1767
…		…
1245	Note that AnyEvent::Handle will automatically C<start_read> for you when	1773	Note that AnyEvent::Handle will automatically C<start_read> for you when
1246	you change the C<on_read> callback or push/unshift a read callback, and it	1774	you change the C<on_read> callback or push/unshift a read callback, and it
1247	will automatically C<stop_read> for you when neither C<on_read> is set nor	1775	will automatically C<stop_read> for you when neither C<on_read> is set nor
1248	there are any read requests in the queue.	1776	there are any read requests in the queue.
1249		1777
		1778	In older versions of this module (<= 5.3), these methods had no effect,
		1779	as TLS does not support half-duplex connections. In current versions they
		1780	work as expected, as this behaviour is required to avoid certain resource
		1781	attacks, where the program would be forced to read (and buffer) arbitrary
		1782	amounts of data before being able to send some data. The drawback is that
		1783	some readings of the the SSL/TLS specifications basically require this
		1784	attack to be working, as SSL/TLS implementations might stall sending data
		1785	during a rehandshake.
		1786
		1787	As a guideline, during the initial handshake, you should not stop reading,
		1788	and as a client, it might cause problems, depending on your applciation.
		1789
1250	=cut	1790	=cut
1251		1791
1252	sub stop_read {	1792	sub stop_read {
1253	my ($self) = @_;	1793	my ($self) = @_;
1254		1794
…		…
1256	}	1796	}
1257		1797
1258	sub start_read {	1798	sub start_read {
1259	my ($self) = @_;	1799	my ($self) = @_;
1260		1800
1261	unless ($self->{_rw} || $self->{_eof}) {	1801	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1262	Scalar::Util::weaken $self;	1802	Scalar::Util::weaken $self;
1263		1803
1264	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1804	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1265	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1805	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1266	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1806	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1267		1807
1268	if ($len > 0) {	1808	if ($len > 0) {
1269	$self->{_activity} = AnyEvent->now;	1809	$self->{_activity} = $self->{_ractivity} = AE::now;
1270		1810
1271	$self->{filter_r}	1811	if ($self->{tls}) {
1272	? $self->{filter_r}($self, $rbuf)	1812	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1273	: $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	}
1274		1824
1275	} elsif (defined $len) {	1825	} elsif (defined $len) {
1276	delete $self->{_rw};	1826	delete $self->{_rw};
1277	$self->{_eof} = 1;	1827	$self->{_eof} = 1;
1278	$self->_drain_rbuf unless $self->{_in_drain};	1828	$self->_drain_rbuf;
1279		1829
1280	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1830	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1281	return $self->_error ($!, 1);	1831	return $self->_error ($!, 1);
1282	}	1832	}
1283	});	1833	};
1284	}	1834	}
1285	}	1835	}
1286		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, $err);
		1857	}
		1858	}
		1859
		1860	# poll the write BIO and send the data if applicable
		1861	# also decode read data if possible
		1862	# this is basiclaly our TLS state machine
		1863	# more efficient implementations are possible with openssl,
		1864	# but not with the buggy and incomplete Net::SSLeay.
1287	sub _dotls {	1865	sub _dotls {
1288	my ($self) = @_;	1866	my ($self) = @_;
1289		1867
1290	my $buf;	1868	my $tmp;
1291		1869
1292	if (length $self->{_tls_wbuf}) {	1870	if (length $self->{_tls_wbuf}) {
1293	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1871	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1294	substr $self->{_tls_wbuf}, 0, $len, "";	1872	substr $self->{_tls_wbuf}, 0, $tmp, "";
1295	}	1873	}
1296	}
1297		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 || $!);
		1906
1298	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1907	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1299	$self->{wbuf} .= $buf;	1908	$self->{wbuf} .= $tmp;
1300	$self->_drain_wbuf;	1909	$self->_drain_wbuf;
		1910	$self->{tls} or return; # tls session might have gone away in callback
1301	}	1911	}
1302		1912
1303	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {	1913	$self->{_on_starttls}
1304	if (length $buf) {	1914	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1305	$self->{rbuf} .= $buf;	1915	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1306	$self->_drain_rbuf unless $self->{_in_drain};
1307	} else {
1308	# let's treat SSL-eof as we treat normal EOF
1309	$self->{_eof} = 1;
1310	$self->_shutdown;
1311	return;
1312	}
1313	}
1314
1315	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1316
1317	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1318	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1319	return $self->_error ($!, 1);
1320	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1321	return $self->_error (&Errno::EIO, 1);
1322	}
1323
1324	# all others are fine for our purposes
1325	}
1326	}	1916	}
1327		1917
1328	=item $handle->starttls ($tls[, $tls_ctx])	1918	=item $handle->starttls ($tls[, $tls_ctx])
1329		1919
1330	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1920	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1331	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
1332	C<starttls>.	1922	C<starttls>.
1333		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
1334	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
1335	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1929	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1336		1930
1337	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
1338	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.
1339		1935
1340	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
1341	call and can be used or changed to your liking. Note that the handshake	1937	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1342	might have already started when this function returns.	1938	changed to your liking. Note that the handshake might have already started
		1939	when this function returns.
1343		1940
		1941	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1942	handshakes on the same stream. It is best to not attempt to use the
		1943	stream after stopping TLS.
		1944
		1945	This method may invoke callbacks (and therefore the handle might be
		1946	destroyed after it returns).
		1947
1344	=cut	1948	=cut
		1949
		1950	our %TLS_CACHE; #TODO not yet documented, should we?
1345		1951
1346	sub starttls {	1952	sub starttls {
1347	my ($self, $ssl, $ctx) = @_;	1953	my ($self, $tls, $ctx) = @_;
1348		1954
1349	$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 $self->{tls};
1350		1957
1351	if ($ssl eq "accept") {	1958	$self->{tls} = $tls;
1352	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1959	$self->{tls_ctx} = $ctx if @_ > 2;
1353	Net::SSLeay::set_accept_state ($ssl);	1960
1354	} elsif ($ssl eq "connect") {	1961	return unless $self->{fh};
1355	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1962
1356	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	}
1357	}	1983
1358		1984	$self->{tls_ctx} = $ctx || TLS_CTX ();
1359	$self->{tls} = $ssl;	1985	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1360		1986
1361	# basically, this is deep magic (because SSL_read should have the same issues)	1987	# basically, this is deep magic (because SSL_read should have the same issues)
1362	# but the openssl maintainers basically said: "trust us, it just works".	1988	# but the openssl maintainers basically said: "trust us, it just works".
1363	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1989	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1364	# and mismaintained ssleay-module doesn't even offer them).	1990	# and mismaintained ssleay-module doesn't even offer them).
1365	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1991	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1992	#
		1993	# in short: this is a mess.
		1994	#
		1995	# note that we do not try to keep the length constant between writes as we are required to do.
		1996	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1997	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1998	# have identity issues in that area.
1366	Net::SSLeay::CTX_set_mode ($self->{tls},	1999	# Net::SSLeay::CTX_set_mode ($ssl,
1367	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2000	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1368	| (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);
1369		2003
1370	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2004	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1371	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2005	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372		2006
		2007	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		2008
1373	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2009	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1374		2010
1375	$self->{filter_w} = sub {	2011	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1376	$_[0]{_tls_wbuf} .= ${$_[1]};	2012	if $self->{on_starttls};
1377	&_dotls;	2013
1378	};	2014	&_dotls; # need to trigger the initial handshake
1379	$self->{filter_r} = sub {	2015	$self->start_read; # make sure we actually do read
1380	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1381	&_dotls;
1382	};
1383	}	2016	}
1384		2017
1385	=item $handle->stoptls	2018	=item $handle->stoptls
1386		2019
1387	Destroys the SSL connection, if any. Partial read or write data will be	2020	Shuts down the SSL connection - this makes a proper EOF handshake by
1388	lost.	2021	sending a close notify to the other side, but since OpenSSL doesn't
		2022	support non-blocking shut downs, it is not guaranteed that you can re-use
		2023	the stream afterwards.
		2024
		2025	This method may invoke callbacks (and therefore the handle might be
		2026	destroyed after it returns).
1389		2027
1390	=cut	2028	=cut
1391		2029
1392	sub stoptls {	2030	sub stoptls {
1393	my ($self) = @_;	2031	my ($self) = @_;
1394		2032
1395	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2033	if ($self->{tls} && $self->{fh}) {
		2034	Net::SSLeay::shutdown ($self->{tls});
1396		2035
1397	delete $self->{_rbio};	2036	&_dotls;
1398	delete $self->{_wbio};	2037
1399	delete $self->{_tls_wbuf};	2038	# # we don't give a shit. no, we do, but we can't. no...#d#
1400	delete $self->{filter_r};	2039	# # we, we... have to use openssl :/#d#
1401	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)};
1402	}	2053	}
1403		2054
1404	sub DESTROY {	2055	sub DESTROY {
1405	my $self = shift;	2056	my ($self) = @_;
1406		2057
1407	$self->stoptls;	2058	&_freetls;
1408		2059
1409	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2060	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1410		2061
1411	if ($linger && length $self->{wbuf}) {	2062	if ($linger && length $self->{wbuf} && $self->{fh}) {
1412	my $fh = delete $self->{fh};	2063	my $fh = delete $self->{fh};
1413	my $wbuf = delete $self->{wbuf};	2064	my $wbuf = delete $self->{wbuf};
1414		2065
1415	my @linger;	2066	my @linger;
1416		2067
1417	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2068	push @linger, AE::io $fh, 1, sub {
1418	my $len = syswrite $fh, $wbuf, length $wbuf;	2069	my $len = syswrite $fh, $wbuf, length $wbuf;
1419		2070
1420	if ($len > 0) {	2071	if ($len > 0) {
1421	substr $wbuf, 0, $len, "";	2072	substr $wbuf, 0, $len, "";
1422	} else {	2073	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1423	@linger = (); # end	2074	@linger = (); # end
1424	}	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.
1425	});	2256	});
1426	push @linger, AnyEvent->timer (after => $linger, cb => sub {
1427	@linger = ();
1428	});	2257	});
		2258
		2259	=item I get different callback invocations in TLS mode/Why can't I pause
		2260	reading?
		2261
		2262	Unlike, say, TCP, TLS connections do not consist of two independent
		2263	communication channels, one for each direction. Or put differently, the
		2264	read and write directions are not independent of each other: you cannot
		2265	write data unless you are also prepared to read, and vice versa.
		2266
		2267	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2268	callback invocations when you are not expecting any read data - the reason
		2269	is that AnyEvent::Handle always reads in TLS mode.
		2270
		2271	During the connection, you have to make sure that you always have a
		2272	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2273	connection (or when you no longer want to use it) you can call the
		2274	C<destroy> method.
		2275
		2276	=item How do I read data until the other side closes the connection?
		2277
		2278	If you just want to read your data into a perl scalar, the easiest way
		2279	to achieve this is by setting an C<on_read> callback that does nothing,
		2280	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2281	will be in C<$_[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 (...);
1429	}	2330	};
1430	}
1431		2331
1432	=item AnyEvent::Handle::TLS_CTX	2332	=item I want to contact a TLS/SSL server, I do care about security.
1433		2333
1434	This function creates and returns the Net::SSLeay::CTX object used by	2334	Then you should additionally enable certificate verification, including
1435	default for TLS mode.	2335	peername verification, if the protocol you use supports it (see
		2336	L<AnyEvent::TLS>, C<verify_peername>).
1436		2337
1437	The context is created like this:	2338	E.g. for HTTPS:
1438		2339
1439	Net::SSLeay::load_error_strings;	2340	tcp_connect $host, $port, sub {
1440	Net::SSLeay::SSLeay_add_ssl_algorithms;	2341	my ($fh) = @_;
1441	Net::SSLeay::randomize;
1442		2342
1443	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	...
1444		2349
1445	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.
1446		2353
1447	=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>:
1448		2357
1449	our $TLS_CTX;	2358	tls_ctx => {
		2359	verify => 1,
		2360	verify_peername => "https",
		2361	ca_file => "my-ca-cert.pem",
		2362	},
1450		2363
1451	sub TLS_CTX() {	2364	=item I want to create a TLS/SSL server, how do I do that?
1452	$TLS_CTX || do {
1453	require Net::SSLeay;
1454		2365
1455	Net::SSLeay::load_error_strings ();	2366	Well, you first need to get a server certificate and key. You have
1456	Net::SSLeay::SSLeay_add_ssl_algorithms ();	2367	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1457	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).
1458		2371
1459	$TLS_CTX = Net::SSLeay::CTX_new ();	2372	Then create a file with your private key (in PEM format, see
		2373	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2374	file should then look like this:
1460		2375
1461	Net::SSLeay::CTX_set_options ($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-----
1462		2380
1463	$TLS_CTX	2381	-----BEGIN CERTIFICATE-----
1464	}	2382	... lots of base64'y-stuff
1465	}	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>.
1466		2399
1467	=back	2400	=back
		2401
1468		2402
1469	=head1 SUBCLASSING AnyEvent::Handle	2403	=head1 SUBCLASSING AnyEvent::Handle
1470		2404
1471	In many cases, you might want to subclass AnyEvent::Handle.	2405	In many cases, you might want to subclass AnyEvent::Handle.
1472		2406
…		…
1489		2423
1490	=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
1491	are free to use in subclasses.	2425	are free to use in subclasses.
1492		2426
1493	Of course, new versions of AnyEvent::Handle may introduce more "public"	2427	Of course, new versions of AnyEvent::Handle may introduce more "public"
1494	member variables, but thats just life, at least it is documented.	2428	member variables, but that's just life. At least it is documented.
1495		2429
1496	=back	2430	=back
1497		2431
1498	=head1 AUTHOR	2432	=head1 AUTHOR
1499		2433

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