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Revision 1.132 by elmex, Thu Jul 2 22:25:13 2009 UTC vs.
Revision 1.226 by root, Mon Dec 12 12:56:04 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 = 4.45;
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; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	AE::log error => "got error $msg\n";
		17	$hdl->destroy;
32	$cv->send;	18	$cv->send;
33	},
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	say "got line <$line>";
43	$cv->send;	28	$cv->send;
44	});	29	});
45		30
46	$cv->recv;	31	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	This module is a helper module to make it easier to do event-based I/O on	35	This is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
54	The L<AnyEvent::Intro> tutorial contains some well-documented	38	The L<AnyEvent::Intro> tutorial contains some well-documented
55	AnyEvent::Handle examples.	39	AnyEvent::Handle examples.
56		40
57	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
58	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
59	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
60		47
61	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
62	argument.	49	argument.
63		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
64	=head1 METHODS	82	=head1 METHODS
65		83
66	=over 4	84	=over 4
67		85
68	=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
69		87
70	The constructor supports these arguments (all as C<< key => value >> pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
71		89
72	=over 4	90	=over 4
73		91
74	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
75		93
76	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
77
78	NOTE: The filehandle will be set to non-blocking mode (using	95	NOTE: The filehandle will be set to non-blocking mode (using
79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80	that mode.	97	that mode.
81		98
		99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		100
		101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
		104
		105	You have to specify either this parameter, or C<fh>, above.
		106
		107	It is possible to push requests on the read and write queues, and modify
		108	properties of the stream, even while AnyEvent::Handle is connecting.
		109
		110	When this parameter is specified, then the C<on_prepare>,
		111	C<on_connect_error> and C<on_connect> callbacks will be called under the
		112	appropriate circumstances:
		113
		114	=over 4
		115
		116	=item on_prepare => $cb->($handle)
		117
		118	This (rarely used) callback is called before a new connection is
		119	attempted, but after the file handle has been created (you can access that
		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).
		123
		124	The return value of this callback should be the connect timeout value in
		125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
		126	default timeout is to be used).
		127
		128	=item on_connect => $cb->($handle, $host, $port, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback.
		134
		135	If, for some reason, the handle is not acceptable, calling C<$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
		154	=item on_error => $cb->($handle, $fatal, $message)
		155
		156	This is the error callback, which is called when, well, some error
		157	occured, such as not being able to resolve the hostname, failure to
		158	connect, or a read error.
		159
		160	Some errors are fatal (which is indicated by C<$fatal> being true). On
		161	fatal errors the handle object will be destroyed (by a call to C<< ->
		162	destroy >>) after invoking the error callback (which means you are free to
		163	examine the handle object). Examples of fatal errors are an EOF condition
		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.
		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
		173	Non-fatal errors can be retried by returning, but it is recommended
		174	to simply ignore this parameter and instead abondon the handle object
		175	when this callback is invoked. Examples of non-fatal errors are timeouts
		176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		177
		178	On entry to the callback, the value of C<$!> contains the operating
		179	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		180	C<EPROTO>).
		181
		182	While not mandatory, it is I<highly> recommended to set this callback, as
		183	you will not be notified of errors otherwise. The default just calls
		184	C<croak>.
		185
		186	=item on_read => $cb->($handle)
		187
		188	This sets the default read callback, which is called when data arrives
		189	and no read request is in the queue (unlike read queue callbacks, this
		190	callback will only be called when at least one octet of data is in the
		191	read buffer).
		192
		193	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
		201	When an EOF condition is detected, AnyEvent::Handle will first try to
		202	feed all the remaining data to the queued callbacks and C<on_read> before
		203	calling the C<on_eof> callback. If no progress can be made, then a fatal
		204	error will be raised (with C<$!> set to C<EPIPE>).
		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
82	=item on_eof => $cb->($handle)	211	=item on_eof => $cb->($handle)
83		212
84	Set the callback to be called when an end-of-file condition is detected,	213	Set the callback to be called when an end-of-file condition is detected,
85	i.e. in the case of a socket, when the other side has closed the	214	i.e. in the case of a socket, when the other side has closed the
86	connection cleanly.	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).
87		218
88	For sockets, this just means that the other side has stopped sending data,	219	For sockets, this just means that the other side has stopped sending data,
89	you can still try to write data, and, in fact, one can return from the EOF	220	you can still try to write data, and, in fact, one can return from the EOF
90	callback and continue writing data, as only the read part has been shut	221	callback and continue writing data, as only the read part has been shut
91	down.	222	down.
92		223
93	While not mandatory, it is I<highly> recommended to set an EOF callback,
94	otherwise you might end up with a closed socket while you are still
95	waiting for data.
96
97	If an EOF condition has been detected but no C<on_eof> callback has been	224	If an EOF condition has been detected but no C<on_eof> callback has been
98	set, then a fatal error will be raised with C<$!> set to <0>.	225	set, then a fatal error will be raised with C<$!> set to <0>.
99		226
100	=item on_error => $cb->($handle, $fatal)
101
102	This is the error callback, which is called when, well, some error
103	occured, such as not being able to resolve the hostname, failure to
104	connect or a read error.
105
106	Some errors are fatal (which is indicated by C<$fatal> being true). On
107	fatal errors the handle object will be shut down and will not be usable
108	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109	errors are an EOF condition with active (but unsatisifable) read watchers
110	(C<EPIPE>) or I/O errors.
111
112	Non-fatal errors can be retried by simply returning, but it is recommended
113	to simply ignore this parameter and instead abondon the handle object
114	when this callback is invoked. Examples of non-fatal errors are timeouts
115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
116
117	On callback entrance, the value of C<$!> contains the operating system
118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
119
120	While not mandatory, it is I<highly> recommended to set this callback, as
121	you will not be notified of errors otherwise. The default simply calls
122	C<croak>.
123
124	=item on_read => $cb->($handle)
125
126	This sets the default read callback, which is called when data arrives
127	and no read request is in the queue (unlike read queue callbacks, this
128	callback will only be called when at least one octet of data is in the
129	read buffer).
130
131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
132	method or access the C<$handle->{rbuf}> member directly. Note that you
133	must not enlarge or modify the read buffer, you can only remove data at
134	the beginning from it.
135
136	When an EOF condition is detected then AnyEvent::Handle will first try to
137	feed all the remaining data to the queued callbacks and C<on_read> before
138	calling the C<on_eof> callback. If no progress can be made, then a fatal
139	error will be raised (with C<$!> set to C<EPIPE>).
140
141	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
142		228
143	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
144	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
145		231
146	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.
147		233
148	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
149	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
…		…
151	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
152	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
153		239
154	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
155		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
156	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
157	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
158	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
159	missing, a non-fatal C<ETIMEDOUT> error will be raised).	249	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		250	error will be raised).
160		251
		252	There are three variants of the timeouts that work independently of each
		253	other, for both read and write (triggered when nothing was read I<OR>
		254	written), just read (triggered when nothing was read), and just write:
		255	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		256	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		257	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		258
161	Note that timeout processing is also active when you currently do not have	259	Note that timeout processing is active even when you do not have any
162	any outstanding read or write requests: If you plan to keep the connection	260	outstanding read or write requests: If you plan to keep the connection
163	idle then you should disable the timout temporarily or ignore the timeout	261	idle then you should disable the timeout temporarily or ignore the
164	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply	262	timeout in the corresponding C<on_timeout> callback, in which case
165	restart the timeout.	263	AnyEvent::Handle will simply restart the timeout.
166		264
167	Zero (the default) disables this timeout.	265	Zero (the default) disables the corresponding timeout.
168		266
169	=item on_timeout => $cb->($handle)	267	=item on_timeout => $cb->($handle)
		268
		269	=item on_rtimeout => $cb->($handle)
		270
		271	=item on_wtimeout => $cb->($handle)
170		272
171	Called whenever the inactivity timeout passes. If you return from this	273	Called whenever the inactivity timeout passes. If you return from this
172	callback, then the timeout will be reset as if some activity had happened,	274	callback, then the timeout will be reset as if some activity had happened,
173	so this condition is not fatal in any way.	275	so this condition is not fatal in any way.
174		276
…		…
182	be configured to accept only so-and-so much data that it cannot act on	284	be configured to accept only so-and-so much data that it cannot act on
183	(for example, when expecting a line, an attacker could send an unlimited	285	(for example, when expecting a line, an attacker could send an unlimited
184	amount of data without a callback ever being called as long as the line	286	amount of data without a callback ever being called as long as the line
185	isn't finished).	287	isn't finished).
186		288
		289	=item wbuf_max => <bytes>
		290
		291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		292	when the write buffer ever (strictly) exceeds this size. This is useful to
		293	avoid some forms of denial-of-service attacks.
		294
		295	Although the units of this parameter is bytes, this is the I<raw> number
		296	of bytes not yet accepted by the kernel. This can make a difference when
		297	you e.g. use TLS, as TLS typically makes your write data larger (but it
		298	can also make it smaller due to compression).
		299
		300	As an example of when this limit is useful, take a chat server that sends
		301	chat messages to a client. If the client does not read those in a timely
		302	manner then the send buffer in the server would grow unbounded.
		303
187	=item autocork => <boolean>	304	=item autocork => <boolean>
188		305
189	When disabled (the default), then C<push_write> will try to immediately	306	When disabled (the default), C<push_write> will try to immediately
190	write the data to the handle, if possible. This avoids having to register	307	write the data to the handle if possible. This avoids having to register
191	a write watcher and wait for the next event loop iteration, but can	308	a write watcher and wait for the next event loop iteration, but can
192	be inefficient if you write multiple small chunks (on the wire, this	309	be inefficient if you write multiple small chunks (on the wire, this
193	disadvantage is usually avoided by your kernel's nagle algorithm, see	310	disadvantage is usually avoided by your kernel's nagle algorithm, see
194	C<no_delay>, but this option can save costly syscalls).	311	C<no_delay>, but this option can save costly syscalls).
195		312
196	When enabled, then writes will always be queued till the next event loop	313	When enabled, writes will always be queued till the next event loop
197	iteration. This is efficient when you do many small writes per iteration,	314	iteration. This is efficient when you do many small writes per iteration,
198	but less efficient when you do a single write only per iteration (or when	315	but less efficient when you do a single write only per iteration (or when
199	the write buffer often is full). It also increases write latency.	316	the write buffer often is full). It also increases write latency.
200		317
201	=item no_delay => <boolean>	318	=item no_delay => <boolean>
…		…
205	the Nagle algorithm, and usually it is beneficial.	322	the Nagle algorithm, and usually it is beneficial.
206		323
207	In some situations you want as low a delay as possible, which can be	324	In some situations you want as low a delay as possible, which can be
208	accomplishd by setting this option to a true value.	325	accomplishd by setting this option to a true value.
209		326
210	The default is your opertaing system's default behaviour (most likely	327	The default is your operating system's default behaviour (most likely
211	enabled), this option explicitly enables or disables it, if possible.	328	enabled). This option explicitly enables or disables it, if possible.
		329
		330	=item keepalive => <boolean>
		331
		332	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		333	normally, TCP connections have no time-out once established, so TCP
		334	connections, once established, can stay alive forever even when the other
		335	side has long gone. TCP keepalives are a cheap way to take down long-lived
		336	TCP connections when the other side becomes unreachable. While the default
		337	is OS-dependent, TCP keepalives usually kick in after around two hours,
		338	and, if the other side doesn't reply, take down the TCP connection some 10
		339	to 15 minutes later.
		340
		341	It is harmless to specify this option for file handles that do not support
		342	keepalives, and enabling it on connections that are potentially long-lived
		343	is usually a good idea.
		344
		345	=item oobinline => <boolean>
		346
		347	BSD majorly fucked up the implementation of TCP urgent data. The result
		348	is that almost no OS implements TCP according to the specs, and every OS
		349	implements it slightly differently.
		350
		351	If you want to handle TCP urgent data, then setting this flag (the default
		352	is enabled) gives you the most portable way of getting urgent data, by
		353	putting it into the stream.
		354
		355	Since BSD emulation of OOB data on top of TCP's urgent data can have
		356	security implications, AnyEvent::Handle sets this flag automatically
		357	unless explicitly specified. Note that setting this flag after
		358	establishing a connection I<may> be a bit too late (data loss could
		359	already have occured on BSD systems), but at least it will protect you
		360	from most attacks.
212		361
213	=item read_size => <bytes>	362	=item read_size => <bytes>
214		363
215	The default read block size (the amount of bytes this module will	364	The initial read block size, the number of bytes this module will try
216	try to read during each loop iteration, which affects memory	365	to read during each loop iteration. Each handle object will consume
217	requirements). Default: C<8192>.	366	at least this amount of memory for the read buffer as well, so when
		367	handling many connections watch out for memory requirements). See also
		368	C<max_read_size>. Default: C<2048>.
		369
		370	=item max_read_size => <bytes>
		371
		372	The maximum read buffer size used by the dynamic adjustment
		373	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		374	one go it will double C<read_size> up to the maximum given by this
		375	option. Default: C<131072> or C<read_size>, whichever is higher.
218		376
219	=item low_water_mark => <bytes>	377	=item low_water_mark => <bytes>
220		378
221	Sets the amount of bytes (default: C<0>) that make up an "empty" write	379	Sets the number of bytes (default: C<0>) that make up an "empty" write
222	buffer: If the write reaches this size or gets even samller it is	380	buffer: If the buffer reaches this size or gets even samller it is
223	considered empty.	381	considered empty.
224		382
225	Sometimes it can be beneficial (for performance reasons) to add data to	383	Sometimes it can be beneficial (for performance reasons) to add data to
226	the write buffer before it is fully drained, but this is a rare case, as	384	the write buffer before it is fully drained, but this is a rare case, as
227	the operating system kernel usually buffers data as well, so the default	385	the operating system kernel usually buffers data as well, so the default
228	is good in almost all cases.	386	is good in almost all cases.
229		387
230	=item linger => <seconds>	388	=item linger => <seconds>
231		389
232	If non-zero (default: C<3600>), then the destructor of the	390	If this is non-zero (default: C<3600>), the destructor of the
233	AnyEvent::Handle object will check whether there is still outstanding	391	AnyEvent::Handle object will check whether there is still outstanding
234	write data and will install a watcher that will write this data to the	392	write data and will install a watcher that will write this data to the
235	socket. No errors will be reported (this mostly matches how the operating	393	socket. No errors will be reported (this mostly matches how the operating
236	system treats outstanding data at socket close time).	394	system treats outstanding data at socket close time).
237		395
238	This will not work for partial TLS data that could not be encoded	396	This will not work for partial TLS data that could not be encoded
239	yet. This data will be lost. Calling the C<stoptls> method in time might	397	yet. This data will be lost. Calling the C<stoptls> method in time might
240	help.	398	help.
241		399
242	=item common_name => $string	400	=item peername => $string
243		401
244	The common name used by some verification methods (most notably SSL/TLS)	402	A string used to identify the remote site - usually the DNS hostname
245	associated with this connection. Usually this is the remote hostname used	403	(I<not> IDN!) used to create the connection, rarely the IP address.
246	to connect, but can be almost anything.	404
		405	Apart from being useful in error messages, this string is also used in TLS
		406	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		407	verification will be skipped when C<peername> is not specified or is
		408	C<undef>.
247		409
248	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	410	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
249		411
250	When this parameter is given, it enables TLS (SSL) mode, that means	412	When this parameter is given, it enables TLS (SSL) mode, that means
251	AnyEvent will start a TLS handshake as soon as the conenction has been	413	AnyEvent will start a TLS handshake as soon as the connection has been
252	established and will transparently encrypt/decrypt data afterwards.	414	established and will transparently encrypt/decrypt data afterwards.
		415
		416	All TLS protocol errors will be signalled as C<EPROTO>, with an
		417	appropriate error message.
253		418
254	TLS mode requires Net::SSLeay to be installed (it will be loaded	419	TLS mode requires Net::SSLeay to be installed (it will be loaded
255	automatically when you try to create a TLS handle): this module doesn't	420	automatically when you try to create a TLS handle): this module doesn't
256	have a dependency on that module, so if your module requires it, you have	421	have a dependency on that module, so if your module requires it, you have
257	to add the dependency yourself.	422	to add the dependency yourself.
…		…
273	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,	438	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
274	passing in the wrong integer will lead to certain crash. This most often	439	passing in the wrong integer will lead to certain crash. This most often
275	happens when one uses a stylish C<< tls => 1 >> and is surprised about the	440	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
276	segmentation fault.	441	segmentation fault.
277		442
278	See the C<< ->starttls >> method for when need to start TLS negotiation later.	443	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
279		444
280	=item tls_ctx => $anyevent_tls	445	=item tls_ctx => $anyevent_tls
281		446
282	Use the given C<AnyEvent::TLS> object to create the new TLS connection	447	Use the given C<AnyEvent::TLS> object to create the new TLS connection
283	(unless a connection object was specified directly). If this parameter is	448	(unless a connection object was specified directly). If this
284	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	449	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		450	C<AnyEvent::Handle::TLS_CTX>.
285		451
286	Instead of an object, you can also specify a hash reference with C<< key	452	Instead of an object, you can also specify a hash reference with C<< key
287	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a	453	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
288	new TLS context object.	454	new TLS context object.
289		455
		456	=item on_starttls => $cb->($handle, $success[, $error_message])
		457
		458	This callback will be invoked when the TLS/SSL handshake has finished. If
		459	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		460	(C<on_stoptls> will not be called in this case).
		461
		462	The session in C<< $handle->{tls} >> can still be examined in this
		463	callback, even when the handshake was not successful.
		464
		465	TLS handshake failures will not cause C<on_error> to be invoked when this
		466	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		467
		468	Without this callback, handshake failures lead to C<on_error> being
		469	called as usual.
		470
		471	Note that you cannot just call C<starttls> again in this callback. If you
		472	need to do that, start an zero-second timer instead whose callback can
		473	then call C<< ->starttls >> again.
		474
		475	=item on_stoptls => $cb->($handle)
		476
		477	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		478	set, then it will be invoked after freeing the TLS session. If it is not,
		479	then a TLS shutdown condition will be treated like a normal EOF condition
		480	on the handle.
		481
		482	The session in C<< $handle->{tls} >> can still be examined in this
		483	callback.
		484
		485	This callback will only be called on TLS shutdowns, not when the
		486	underlying handle signals EOF.
		487
290	=item json => JSON or JSON::XS object	488	=item json => JSON or JSON::XS object
291		489
292	This is the json coder object used by the C<json> read and write types.	490	This is the json coder object used by the C<json> read and write types.
293		491
294	If you don't supply it, then AnyEvent::Handle will create and use a	492	If you don't supply it, then AnyEvent::Handle will create and use a
…		…
304		502
305	sub new {	503	sub new {
306	my $class = shift;	504	my $class = shift;
307	my $self = bless { @_ }, $class;	505	my $self = bless { @_ }, $class;
308		506
309	$self->{fh} or Carp::croak "mandatory argument fh is missing";	507	if ($self->{fh}) {
		508	$self->_start;
		509	return unless $self->{fh}; # could be gone by now
		510
		511	} elsif ($self->{connect}) {
		512	require AnyEvent::Socket;
		513
		514	$self->{peername} = $self->{connect}[0]
		515	unless exists $self->{peername};
		516
		517	$self->{_skip_drain_rbuf} = 1;
		518
		519	{
		520	Scalar::Util::weaken (my $self = $self);
		521
		522	$self->{_connect} =
		523	AnyEvent::Socket::tcp_connect (
		524	$self->{connect}[0],
		525	$self->{connect}[1],
		526	sub {
		527	my ($fh, $host, $port, $retry) = @_;
		528
		529	delete $self->{_connect}; # no longer needed
		530
		531	if ($fh) {
		532	$self->{fh} = $fh;
		533
		534	delete $self->{_skip_drain_rbuf};
		535	$self->_start;
		536
		537	$self->{on_connect}
		538	and $self->{on_connect}($self, $host, $port, sub {
		539	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		540	$self->{_skip_drain_rbuf} = 1;
		541	&$retry;
		542	});
		543
		544	} else {
		545	if ($self->{on_connect_error}) {
		546	$self->{on_connect_error}($self, "$!");
		547	$self->destroy if $self;
		548	} else {
		549	$self->_error ($!, 1);
		550	}
		551	}
		552	},
		553	sub {
		554	local $self->{fh} = $_[0];
		555
		556	$self->{on_prepare}
		557	? $self->{on_prepare}->($self)
		558	: ()
		559	}
		560	);
		561	}
		562
		563	} else {
		564	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		565	}
		566
		567	$self
		568	}
		569
		570	sub _start {
		571	my ($self) = @_;
		572
		573	# too many clueless people try to use udp and similar sockets
		574	# with AnyEvent::Handle, do them a favour.
		575	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		576	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		577	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
310		578
311	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	579	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
312		580
		581	$self->{_activity} =
		582	$self->{_ractivity} =
313	$self->{_activity} = AnyEvent->now;	583	$self->{_wactivity} = AE::now;
314	$self->_timeout;
315		584
		585	$self->{read_size} ||= 2048;
		586	$self->{max_read_size} = $self->{read_size}
		587	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		588
		589	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		590	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		591	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		592
316	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};	593	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		594	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
317		595
		596	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		597
318	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})	598	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
319	if $self->{tls};	599	if $self->{tls};
320		600
321	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	601	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
322		602
323	$self->start_read	603	$self->start_read
324	if $self->{on_read};	604	if $self->{on_read} || @{ $self->{_queue} };
325		605
326	$self->{fh} && $self	606	$self->_drain_wbuf;
327	}
328
329	sub _shutdown {
330	my ($self) = @_;
331
332	delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
333	$self->{_eof} = 1; # tell starttls et. al to stop trying
334
335	&_freetls;
336	}	607	}
337		608
338	sub _error {	609	sub _error {
339	my ($self, $errno, $fatal) = @_;	610	my ($self, $errno, $fatal, $message) = @_;
340
341	$self->_shutdown
342	if $fatal;
343		611
344	$! = $errno;	612	$! = $errno;
		613	$message ||= "$!";
345		614
346	if ($self->{on_error}) {	615	if ($self->{on_error}) {
347	$self->{on_error}($self, $fatal);	616	$self->{on_error}($self, $fatal, $message);
348	} elsif ($self->{fh}) {	617	$self->destroy if $fatal;
		618	} elsif ($self->{fh} || $self->{connect}) {
		619	$self->destroy;
349	Carp::croak "AnyEvent::Handle uncaught error: $!";	620	Carp::croak "AnyEvent::Handle uncaught error: $message";
350	}	621	}
351	}	622	}
352		623
353	=item $fh = $handle->fh	624	=item $fh = $handle->fh
354		625
…		…
378	$_[0]{on_eof} = $_[1];	649	$_[0]{on_eof} = $_[1];
379	}	650	}
380		651
381	=item $handle->on_timeout ($cb)	652	=item $handle->on_timeout ($cb)
382		653
383	Replace the current C<on_timeout> callback, or disables the callback (but	654	=item $handle->on_rtimeout ($cb)
384	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
385	argument and method.
386		655
387	=cut	656	=item $handle->on_wtimeout ($cb)
388		657
389	sub on_timeout {	658	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
390	$_[0]{on_timeout} = $_[1];	659	callback, or disables the callback (but not the timeout) if C<$cb> =
391	}	660	C<undef>. See the C<timeout> constructor argument and method.
		661
		662	=cut
		663
		664	# see below
392		665
393	=item $handle->autocork ($boolean)	666	=item $handle->autocork ($boolean)
394		667
395	Enables or disables the current autocork behaviour (see C<autocork>	668	Enables or disables the current autocork behaviour (see C<autocork>
396	constructor argument). Changes will only take effect on the next write.	669	constructor argument). Changes will only take effect on the next write.
…		…
409	=cut	682	=cut
410		683
411	sub no_delay {	684	sub no_delay {
412	$_[0]{no_delay} = $_[1];	685	$_[0]{no_delay} = $_[1];
413		686
		687	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		688	if $_[0]{fh};
		689	}
		690
		691	=item $handle->keepalive ($boolean)
		692
		693	Enables or disables the C<keepalive> setting (see constructor argument of
		694	the same name for details).
		695
		696	=cut
		697
		698	sub keepalive {
		699	$_[0]{keepalive} = $_[1];
		700
414	eval {	701	eval {
415	local $SIG{__DIE__};	702	local $SIG{__DIE__};
416	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];	703	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		704	if $_[0]{fh};
417	};	705	};
418	}	706	}
419		707
		708	=item $handle->oobinline ($boolean)
		709
		710	Enables or disables the C<oobinline> setting (see constructor argument of
		711	the same name for details).
		712
		713	=cut
		714
		715	sub oobinline {
		716	$_[0]{oobinline} = $_[1];
		717
		718	eval {
		719	local $SIG{__DIE__};
		720	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		721	if $_[0]{fh};
		722	};
		723	}
		724
		725	=item $handle->keepalive ($boolean)
		726
		727	Enables or disables the C<keepalive> setting (see constructor argument of
		728	the same name for details).
		729
		730	=cut
		731
		732	sub keepalive {
		733	$_[0]{keepalive} = $_[1];
		734
		735	eval {
		736	local $SIG{__DIE__};
		737	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		738	if $_[0]{fh};
		739	};
		740	}
		741
		742	=item $handle->on_starttls ($cb)
		743
		744	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		745
		746	=cut
		747
		748	sub on_starttls {
		749	$_[0]{on_starttls} = $_[1];
		750	}
		751
		752	=item $handle->on_stoptls ($cb)
		753
		754	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		755
		756	=cut
		757
		758	sub on_stoptls {
		759	$_[0]{on_stoptls} = $_[1];
		760	}
		761
		762	=item $handle->rbuf_max ($max_octets)
		763
		764	Configures the C<rbuf_max> setting (C<undef> disables it).
		765
		766	=item $handle->wbuf_max ($max_octets)
		767
		768	Configures the C<wbuf_max> setting (C<undef> disables it).
		769
		770	=cut
		771
		772	sub rbuf_max {
		773	$_[0]{rbuf_max} = $_[1];
		774	}
		775
		776	sub wbuf_max {
		777	$_[0]{wbuf_max} = $_[1];
		778	}
		779
420	#############################################################################	780	#############################################################################
421		781
422	=item $handle->timeout ($seconds)	782	=item $handle->timeout ($seconds)
423		783
		784	=item $handle->rtimeout ($seconds)
		785
		786	=item $handle->wtimeout ($seconds)
		787
424	Configures (or disables) the inactivity timeout.	788	Configures (or disables) the inactivity timeout.
425		789
426	=cut	790	The timeout will be checked instantly, so this method might destroy the
		791	handle before it returns.
427		792
428	sub timeout {	793	=item $handle->timeout_reset
		794
		795	=item $handle->rtimeout_reset
		796
		797	=item $handle->wtimeout_reset
		798
		799	Reset the activity timeout, as if data was received or sent.
		800
		801	These methods are cheap to call.
		802
		803	=cut
		804
		805	for my $dir ("", "r", "w") {
		806	my $timeout = "${dir}timeout";
		807	my $tw = "_${dir}tw";
		808	my $on_timeout = "on_${dir}timeout";
		809	my $activity = "_${dir}activity";
		810	my $cb;
		811
		812	*$on_timeout = sub {
		813	$_[0]{$on_timeout} = $_[1];
		814	};
		815
		816	*$timeout = sub {
429	my ($self, $timeout) = @_;	817	my ($self, $new_value) = @_;
430		818
		819	$new_value >= 0
		820	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		821
431	$self->{timeout} = $timeout;	822	$self->{$timeout} = $new_value;
432	$self->_timeout;	823	delete $self->{$tw}; &$cb;
433	}	824	};
434		825
		826	*{"${dir}timeout_reset"} = sub {
		827	$_[0]{$activity} = AE::now;
		828	};
		829
		830	# main workhorse:
435	# reset the timeout watcher, as neccessary	831	# reset the timeout watcher, as neccessary
436	# also check for time-outs	832	# also check for time-outs
437	sub _timeout {	833	$cb = sub {
438	my ($self) = @_;	834	my ($self) = @_;
439		835
440	if ($self->{timeout}) {	836	if ($self->{$timeout} && $self->{fh}) {
441	my $NOW = AnyEvent->now;	837	my $NOW = AE::now;
442		838
443	# when would the timeout trigger?	839	# when would the timeout trigger?
444	my $after = $self->{_activity} + $self->{timeout} - $NOW;	840	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
445		841
446	# now or in the past already?	842	# now or in the past already?
447	if ($after <= 0) {	843	if ($after <= 0) {
448	$self->{_activity} = $NOW;	844	$self->{$activity} = $NOW;
449		845
450	if ($self->{on_timeout}) {	846	if ($self->{$on_timeout}) {
451	$self->{on_timeout}($self);	847	$self->{$on_timeout}($self);
452	} else {	848	} else {
453	$self->_error (&Errno::ETIMEDOUT);	849	$self->_error (Errno::ETIMEDOUT);
		850	}
		851
		852	# callback could have changed timeout value, optimise
		853	return unless $self->{$timeout};
		854
		855	# calculate new after
		856	$after = $self->{$timeout};
454	}	857	}
455		858
456	# callback could have changed timeout value, optimise	859	Scalar::Util::weaken $self;
457	return unless $self->{timeout};	860	return unless $self; # ->error could have destroyed $self
458		861
459	# calculate new after	862	$self->{$tw} ||= AE::timer $after, 0, sub {
460	$after = $self->{timeout};	863	delete $self->{$tw};
		864	$cb->($self);
		865	};
		866	} else {
		867	delete $self->{$tw};
461	}	868	}
462
463	Scalar::Util::weaken $self;
464	return unless $self; # ->error could have destroyed $self
465
466	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
467	delete $self->{_tw};
468	$self->_timeout;
469	});
470	} else {
471	delete $self->{_tw};
472	}	869	}
473	}	870	}
474		871
475	#############################################################################	872	#############################################################################
476		873
…		…
492	=item $handle->on_drain ($cb)	889	=item $handle->on_drain ($cb)
493		890
494	Sets the C<on_drain> callback or clears it (see the description of	891	Sets the C<on_drain> callback or clears it (see the description of
495	C<on_drain> in the constructor).	892	C<on_drain> in the constructor).
496		893
		894	This method may invoke callbacks (and therefore the handle might be
		895	destroyed after it returns).
		896
497	=cut	897	=cut
498		898
499	sub on_drain {	899	sub on_drain {
500	my ($self, $cb) = @_;	900	my ($self, $cb) = @_;
501		901
…		…
505	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});	905	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
506	}	906	}
507		907
508	=item $handle->push_write ($data)	908	=item $handle->push_write ($data)
509		909
510	Queues the given scalar to be written. You can push as much data as you	910	Queues the given scalar to be written. You can push as much data as
511	want (only limited by the available memory), as C<AnyEvent::Handle>	911	you want (only limited by the available memory and C<wbuf_max>), as
512	buffers it independently of the kernel.	912	C<AnyEvent::Handle> buffers it independently of the kernel.
		913
		914	This method may invoke callbacks (and therefore the handle might be
		915	destroyed after it returns).
513		916
514	=cut	917	=cut
515		918
516	sub _drain_wbuf {	919	sub _drain_wbuf {
517	my ($self) = @_;	920	my ($self) = @_;
…		…
521	Scalar::Util::weaken $self;	924	Scalar::Util::weaken $self;
522		925
523	my $cb = sub {	926	my $cb = sub {
524	my $len = syswrite $self->{fh}, $self->{wbuf};	927	my $len = syswrite $self->{fh}, $self->{wbuf};
525		928
526	if ($len >= 0) {	929	if (defined $len) {
527	substr $self->{wbuf}, 0, $len, "";	930	substr $self->{wbuf}, 0, $len, "";
528		931
529	$self->{_activity} = AnyEvent->now;	932	$self->{_activity} = $self->{_wactivity} = AE::now;
530		933
531	$self->{on_drain}($self)	934	$self->{on_drain}($self)
532	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})	935	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
533	&& $self->{on_drain};	936	&& $self->{on_drain};
534		937
…		…
540		943
541	# try to write data immediately	944	# try to write data immediately
542	$cb->() unless $self->{autocork};	945	$cb->() unless $self->{autocork};
543		946
544	# if still data left in wbuf, we need to poll	947	# if still data left in wbuf, we need to poll
545	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	948	$self->{_ww} = AE::io $self->{fh}, 1, $cb
546	if length $self->{wbuf};	949	if length $self->{wbuf};
		950
		951	if (
		952	defined $self->{wbuf_max}
		953	&& $self->{wbuf_max} < length $self->{wbuf}
		954	) {
		955	$self->_error (Errno::ENOSPC, 1), return;
		956	}
547	};	957	};
548	}	958	}
549		959
550	our %WH;	960	our %WH;
551		961
		962	# deprecated
552	sub register_write_type($$) {	963	sub register_write_type($$) {
553	$WH{$_[0]} = $_[1];	964	$WH{$_[0]} = $_[1];
554	}	965	}
555		966
556	sub push_write {	967	sub push_write {
557	my $self = shift;	968	my $self = shift;
558		969
559	if (@_ > 1) {	970	if (@_ > 1) {
560	my $type = shift;	971	my $type = shift;
561		972
		973	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
562	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	974	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
563	->($self, @_);	975	->($self, @_);
564	}	976	}
565		977
		978	# we downgrade here to avoid hard-to-track-down bugs,
		979	# and diagnose the problem earlier and better.
		980
566	if ($self->{tls}) {	981	if ($self->{tls}) {
567	$self->{_tls_wbuf} .= $_[0];	982	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
568		983	&_dotls ($self) if $self->{fh};
569	&_dotls ($self);
570	} else {	984	} else {
571	$self->{wbuf} .= $_[0];	985	utf8::downgrade $self->{wbuf} .= $_[0];
572	$self->_drain_wbuf;	986	$self->_drain_wbuf if $self->{fh};
573	}	987	}
574	}	988	}
575		989
576	=item $handle->push_write (type => @args)	990	=item $handle->push_write (type => @args)
577		991
578	Instead of formatting your data yourself, you can also let this module do	992	Instead of formatting your data yourself, you can also let this module
579	the job by specifying a type and type-specific arguments.	993	do the job by specifying a type and type-specific arguments. You
		994	can also specify the (fully qualified) name of a package, in which
		995	case AnyEvent tries to load the package and then expects to find the
		996	C<anyevent_write_type> function inside (see "custom write types", below).
580		997
581	Predefined types are (if you have ideas for additional types, feel free to	998	Predefined types are (if you have ideas for additional types, feel free to
582	drop by and tell us):	999	drop by and tell us):
583		1000
584	=over 4	1001	=over 4
…		…
641	Other languages could read single lines terminated by a newline and pass	1058	Other languages could read single lines terminated by a newline and pass
642	this line into their JSON decoder of choice.	1059	this line into their JSON decoder of choice.
643		1060
644	=cut	1061	=cut
645		1062
		1063	sub json_coder() {
		1064	eval { require JSON::XS; JSON::XS->new->utf8 }
		1065	|| do { require JSON; JSON->new->utf8 }
		1066	}
		1067
646	register_write_type json => sub {	1068	register_write_type json => sub {
647	my ($self, $ref) = @_;	1069	my ($self, $ref) = @_;
648		1070
649	require JSON;	1071	my $json = $self->{json} ||= json_coder;
650		1072
651	$self->{json} ? $self->{json}->encode ($ref)	1073	$json->encode ($ref)
652	: JSON::encode_json ($ref)
653	};	1074	};
654		1075
655	=item storable => $reference	1076	=item storable => $reference
656		1077
657	Freezes the given reference using L<Storable> and writes it to the	1078	Freezes the given reference using L<Storable> and writes it to the
…		…
660	=cut	1081	=cut
661		1082
662	register_write_type storable => sub {	1083	register_write_type storable => sub {
663	my ($self, $ref) = @_;	1084	my ($self, $ref) = @_;
664		1085
665	require Storable;	1086	require Storable unless $Storable::VERSION;
666		1087
667	pack "w/a*", Storable::nfreeze ($ref)	1088	pack "w/a*", Storable::nfreeze ($ref)
668	};	1089	};
669		1090
670	=back	1091	=back
671		1092
672	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1093	=item $handle->push_shutdown
673		1094
674	This function (not method) lets you add your own types to C<push_write>.	1095	Sometimes you know you want to close the socket after writing your data
		1096	before it was actually written. One way to do that is to replace your
		1097	C<on_drain> handler by a callback that shuts down the socket (and set
		1098	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1099	replaces the C<on_drain> callback with:
		1100
		1101	sub { shutdown $_[0]{fh}, 1 }
		1102
		1103	This simply shuts down the write side and signals an EOF condition to the
		1104	the peer.
		1105
		1106	You can rely on the normal read queue and C<on_eof> handling
		1107	afterwards. This is the cleanest way to close a connection.
		1108
		1109	This method may invoke callbacks (and therefore the handle might be
		1110	destroyed after it returns).
		1111
		1112	=cut
		1113
		1114	sub push_shutdown {
		1115	my ($self) = @_;
		1116
		1117	delete $self->{low_water_mark};
		1118	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1119	}
		1120
		1121	=item custom write types - Package::anyevent_write_type $handle, @args
		1122
		1123	Instead of one of the predefined types, you can also specify the name of
		1124	a package. AnyEvent will try to load the package and then expects to find
		1125	a function named C<anyevent_write_type> inside. If it isn't found, it
		1126	progressively tries to load the parent package until it either finds the
		1127	function (good) or runs out of packages (bad).
		1128
675	Whenever the given C<type> is used, C<push_write> will invoke the code	1129	Whenever the given C<type> is used, C<push_write> will the function with
676	reference with the handle object and the remaining arguments.	1130	the handle object and the remaining arguments.
677		1131
678	The code reference is supposed to return a single octet string that will	1132	The function is supposed to return a single octet string that will be
679	be appended to the write buffer.	1133	appended to the write buffer, so you can mentally treat this function as a
		1134	"arguments to on-the-wire-format" converter.
680		1135
681	Note that this is a function, and all types registered this way will be	1136	Example: implement a custom write type C<join> that joins the remaining
682	global, so try to use unique names.	1137	arguments using the first one.
		1138
		1139	$handle->push_write (My::Type => " ", 1,2,3);
		1140
		1141	# uses the following package, which can be defined in the "My::Type" or in
		1142	# the "My" modules to be auto-loaded, or just about anywhere when the
		1143	# My::Type::anyevent_write_type is defined before invoking it.
		1144
		1145	package My::Type;
		1146
		1147	sub anyevent_write_type {
		1148	my ($handle, $delim, @args) = @_;
		1149
		1150	join $delim, @args
		1151	}
683		1152
684	=cut	1153	=cut
685		1154
686	#############################################################################	1155	#############################################################################
687		1156
…		…
696	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1165	ways, the "simple" way, using only C<on_read> and the "complex" way, using
697	a queue.	1166	a queue.
698		1167
699	In the simple case, you just install an C<on_read> callback and whenever	1168	In the simple case, you just install an C<on_read> callback and whenever
700	new data arrives, it will be called. You can then remove some data (if	1169	new data arrives, it will be called. You can then remove some data (if
701	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1170	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
702	leave the data there if you want to accumulate more (e.g. when only a	1171	leave the data there if you want to accumulate more (e.g. when only a
703	partial message has been received so far).	1172	partial message has been received so far), or change the read queue with
		1173	e.g. C<push_read>.
704		1174
705	In the more complex case, you want to queue multiple callbacks. In this	1175	In the more complex case, you want to queue multiple callbacks. In this
706	case, AnyEvent::Handle will call the first queued callback each time new	1176	case, AnyEvent::Handle will call the first queued callback each time new
707	data arrives (also the first time it is queued) and removes it when it has	1177	data arrives (also the first time it is queued) and remove it when it has
708	done its job (see C<push_read>, below).	1178	done its job (see C<push_read>, below).
709		1179
710	This way you can, for example, push three line-reads, followed by reading	1180	This way you can, for example, push three line-reads, followed by reading
711	a chunk of data, and AnyEvent::Handle will execute them in order.	1181	a chunk of data, and AnyEvent::Handle will execute them in order.
712		1182
…		…
769	=cut	1239	=cut
770		1240
771	sub _drain_rbuf {	1241	sub _drain_rbuf {
772	my ($self) = @_;	1242	my ($self) = @_;
773		1243
		1244	# avoid recursion
		1245	return if $self->{_skip_drain_rbuf};
774	local $self->{_in_drain} = 1;	1246	local $self->{_skip_drain_rbuf} = 1;
775
776	if (
777	defined $self->{rbuf_max}
778	&& $self->{rbuf_max} < length $self->{rbuf}
779	) {
780	$self->_error (&Errno::ENOSPC, 1), return;
781	}
782		1247
783	while () {	1248	while () {
784	# we need to use a separate tls read buffer, as we must not receive data while	1249	# we need to use a separate tls read buffer, as we must not receive data while
785	# we are draining the buffer, and this can only happen with TLS.	1250	# we are draining the buffer, and this can only happen with TLS.
786	$self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};	1251	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1252	if exists $self->{_tls_rbuf};
787		1253
788	my $len = length $self->{rbuf};	1254	my $len = length $self->{rbuf};
789		1255
790	if (my $cb = shift @{ $self->{_queue} }) {	1256	if (my $cb = shift @{ $self->{_queue} }) {
791	unless ($cb->($self)) {	1257	unless ($cb->($self)) {
792	if ($self->{_eof}) {	1258	# no progress can be made
793	# no progress can be made (not enough data and no data forthcoming)	1259	# (not enough data and no data forthcoming)
794	$self->_error (&Errno::EPIPE, 1), return;	1260	$self->_error (Errno::EPIPE, 1), return
795	}	1261	if $self->{_eof};
796		1262
797	unshift @{ $self->{_queue} }, $cb;	1263	unshift @{ $self->{_queue} }, $cb;
798	last;	1264	last;
799	}	1265	}
800	} elsif ($self->{on_read}) {	1266	} elsif ($self->{on_read}) {
…		…
807	&& !@{ $self->{_queue} } # and the queue is still empty	1273	&& !@{ $self->{_queue} } # and the queue is still empty
808	&& $self->{on_read} # but we still have on_read	1274	&& $self->{on_read} # but we still have on_read
809	) {	1275	) {
810	# no further data will arrive	1276	# no further data will arrive
811	# so no progress can be made	1277	# so no progress can be made
812	$self->_error (&Errno::EPIPE, 1), return	1278	$self->_error (Errno::EPIPE, 1), return
813	if $self->{_eof};	1279	if $self->{_eof};
814		1280
815	last; # more data might arrive	1281	last; # more data might arrive
816	}	1282	}
817	} else {	1283	} else {
…		…
820	last;	1286	last;
821	}	1287	}
822	}	1288	}
823		1289
824	if ($self->{_eof}) {	1290	if ($self->{_eof}) {
825	if ($self->{on_eof}) {	1291	$self->{on_eof}
826	$self->{on_eof}($self)	1292	? $self->{on_eof}($self)
827	} else {	1293	: $self->_error (0, 1, "Unexpected end-of-file");
828	$self->_error (0, 1);	1294
829	}	1295	return;
		1296	}
		1297
		1298	if (
		1299	defined $self->{rbuf_max}
		1300	&& $self->{rbuf_max} < length $self->{rbuf}
		1301	) {
		1302	$self->_error (Errno::ENOSPC, 1), return;
830	}	1303	}
831		1304
832	# may need to restart read watcher	1305	# may need to restart read watcher
833	unless ($self->{_rw}) {	1306	unless ($self->{_rw}) {
834	$self->start_read	1307	$self->start_read
…		…
840		1313
841	This replaces the currently set C<on_read> callback, or clears it (when	1314	This replaces the currently set C<on_read> callback, or clears it (when
842	the new callback is C<undef>). See the description of C<on_read> in the	1315	the new callback is C<undef>). See the description of C<on_read> in the
843	constructor.	1316	constructor.
844		1317
		1318	This method may invoke callbacks (and therefore the handle might be
		1319	destroyed after it returns).
		1320
845	=cut	1321	=cut
846		1322
847	sub on_read {	1323	sub on_read {
848	my ($self, $cb) = @_;	1324	my ($self, $cb) = @_;
849		1325
850	$self->{on_read} = $cb;	1326	$self->{on_read} = $cb;
851	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1327	$self->_drain_rbuf if $cb;
852	}	1328	}
853		1329
854	=item $handle->rbuf	1330	=item $handle->rbuf
855		1331
856	Returns the read buffer (as a modifiable lvalue).	1332	Returns the read buffer (as a modifiable lvalue). You can also access the
		1333	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1334	much faster, and no less clean).
857		1335
858	You can access the read buffer directly as the C<< ->{rbuf} >>	1336	The only operation allowed on the read buffer (apart from looking at it)
859	member, if you want. However, the only operation allowed on the	1337	is removing data from its beginning. Otherwise modifying or appending to
860	read buffer (apart from looking at it) is removing data from its	1338	it is not allowed and will lead to hard-to-track-down bugs.
861	beginning. Otherwise modifying or appending to it is not allowed and will
862	lead to hard-to-track-down bugs.
863		1339
864	NOTE: The read buffer should only be used or modified if the C<on_read>,	1340	NOTE: The read buffer should only be used or modified in the C<on_read>
865	C<push_read> or C<unshift_read> methods are used. The other read methods	1341	callback or when C<push_read> or C<unshift_read> are used with a single
866	automatically manage the read buffer.	1342	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1343	will manage the read buffer on their own.
867		1344
868	=cut	1345	=cut
869		1346
870	sub rbuf : lvalue {	1347	sub rbuf : lvalue {
871	$_[0]{rbuf}	1348	$_[0]{rbuf}
…		…
888		1365
889	If enough data was available, then the callback must remove all data it is	1366	If enough data was available, then the callback must remove all data it is
890	interested in (which can be none at all) and return a true value. After returning	1367	interested in (which can be none at all) and return a true value. After returning
891	true, it will be removed from the queue.	1368	true, it will be removed from the queue.
892		1369
		1370	These methods may invoke callbacks (and therefore the handle might be
		1371	destroyed after it returns).
		1372
893	=cut	1373	=cut
894		1374
895	our %RH;	1375	our %RH;
896		1376
897	sub register_read_type($$) {	1377	sub register_read_type($$) {
…		…
903	my $cb = pop;	1383	my $cb = pop;
904		1384
905	if (@_) {	1385	if (@_) {
906	my $type = shift;	1386	my $type = shift;
907		1387
		1388	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
908	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1389	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
909	->($self, $cb, @_);	1390	->($self, $cb, @_);
910	}	1391	}
911		1392
912	push @{ $self->{_queue} }, $cb;	1393	push @{ $self->{_queue} }, $cb;
913	$self->_drain_rbuf unless $self->{_in_drain};	1394	$self->_drain_rbuf;
914	}	1395	}
915		1396
916	sub unshift_read {	1397	sub unshift_read {
917	my $self = shift;	1398	my $self = shift;
918	my $cb = pop;	1399	my $cb = pop;
919		1400
920	if (@_) {	1401	if (@_) {
921	my $type = shift;	1402	my $type = shift;
922		1403
		1404	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
923	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1405	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
924	->($self, $cb, @_);	1406	->($self, $cb, @_);
925	}	1407	}
926		1408
927
928	unshift @{ $self->{_queue} }, $cb;	1409	unshift @{ $self->{_queue} }, $cb;
929	$self->_drain_rbuf unless $self->{_in_drain};	1410	$self->_drain_rbuf;
930	}	1411	}
931		1412
932	=item $handle->push_read (type => @args, $cb)	1413	=item $handle->push_read (type => @args, $cb)
933		1414
934	=item $handle->unshift_read (type => @args, $cb)	1415	=item $handle->unshift_read (type => @args, $cb)
935		1416
936	Instead of providing a callback that parses the data itself you can chose	1417	Instead of providing a callback that parses the data itself you can chose
937	between a number of predefined parsing formats, for chunks of data, lines	1418	between a number of predefined parsing formats, for chunks of data, lines
938	etc.	1419	etc. You can also specify the (fully qualified) name of a package, in
		1420	which case AnyEvent tries to load the package and then expects to find the
		1421	C<anyevent_read_type> function inside (see "custom read types", below).
939		1422
940	Predefined types are (if you have ideas for additional types, feel free to	1423	Predefined types are (if you have ideas for additional types, feel free to
941	drop by and tell us):	1424	drop by and tell us):
942		1425
943	=over 4	1426	=over 4
…		…
949	data.	1432	data.
950		1433
951	Example: read 2 bytes.	1434	Example: read 2 bytes.
952		1435
953	$handle->push_read (chunk => 2, sub {	1436	$handle->push_read (chunk => 2, sub {
954	warn "yay ", unpack "H*", $_[1];	1437	say "yay " . unpack "H*", $_[1];
955	});	1438	});
956		1439
957	=cut	1440	=cut
958		1441
959	register_read_type chunk => sub {	1442	register_read_type chunk => sub {
…		…
1035	the receive buffer when neither C<$accept> nor C<$reject> match,	1518	the receive buffer when neither C<$accept> nor C<$reject> match,
1036	and everything preceding and including the match will be accepted	1519	and everything preceding and including the match will be accepted
1037	unconditionally. This is useful to skip large amounts of data that you	1520	unconditionally. This is useful to skip large amounts of data that you
1038	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1521	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1039	have to start matching from the beginning. This is purely an optimisation	1522	have to start matching from the beginning. This is purely an optimisation
1040	and is usually worth only when you expect more than a few kilobytes.	1523	and is usually worth it only when you expect more than a few kilobytes.
1041		1524
1042	Example: expect a http header, which ends at C<\015\012\015\012>. Since we	1525	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1043	expect the header to be very large (it isn't in practise, but...), we use	1526	expect the header to be very large (it isn't in practice, but...), we use
1044	a skip regex to skip initial portions. The skip regex is tricky in that	1527	a skip regex to skip initial portions. The skip regex is tricky in that
1045	it only accepts something not ending in either \015 or \012, as these are	1528	it only accepts something not ending in either \015 or \012, as these are
1046	required for the accept regex.	1529	required for the accept regex.
1047		1530
1048	$handle->push_read (regex =>	1531	$handle->push_read (regex =>
…		…
1061		1544
1062	sub {	1545	sub {
1063	# accept	1546	# accept
1064	if ($$rbuf =~ $accept) {	1547	if ($$rbuf =~ $accept) {
1065	$data .= substr $$rbuf, 0, $+[0], "";	1548	$data .= substr $$rbuf, 0, $+[0], "";
1066	$cb->($self, $data);	1549	$cb->($_[0], $data);
1067	return 1;	1550	return 1;
1068	}	1551	}
1069		1552
1070	# reject	1553	# reject
1071	if ($reject && $$rbuf =~ $reject) {	1554	if ($reject && $$rbuf =~ $reject) {
1072	$self->_error (&Errno::EBADMSG);	1555	$_[0]->_error (Errno::EBADMSG);
1073	}	1556	}
1074		1557
1075	# skip	1558	# skip
1076	if ($skip && $$rbuf =~ $skip) {	1559	if ($skip && $$rbuf =~ $skip) {
1077	$data .= substr $$rbuf, 0, $+[0], "";	1560	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1093	my ($self, $cb) = @_;	1576	my ($self, $cb) = @_;
1094		1577
1095	sub {	1578	sub {
1096	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1579	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1097	if ($_[0]{rbuf} =~ /[^0-9]/) {	1580	if ($_[0]{rbuf} =~ /[^0-9]/) {
1098	$self->_error (&Errno::EBADMSG);	1581	$_[0]->_error (Errno::EBADMSG);
1099	}	1582	}
1100	return;	1583	return;
1101	}	1584	}
1102		1585
1103	my $len = $1;	1586	my $len = $1;
1104		1587
1105	$self->unshift_read (chunk => $len, sub {	1588	$_[0]->unshift_read (chunk => $len, sub {
1106	my $string = $_[1];	1589	my $string = $_[1];
1107	$_[0]->unshift_read (chunk => 1, sub {	1590	$_[0]->unshift_read (chunk => 1, sub {
1108	if ($_[1] eq ",") {	1591	if ($_[1] eq ",") {
1109	$cb->($_[0], $string);	1592	$cb->($_[0], $string);
1110	} else {	1593	} else {
1111	$self->_error (&Errno::EBADMSG);	1594	$_[0]->_error (Errno::EBADMSG);
1112	}	1595	}
1113	});	1596	});
1114	});	1597	});
1115		1598
1116	1	1599	1
…		…
1183	=cut	1666	=cut
1184		1667
1185	register_read_type json => sub {	1668	register_read_type json => sub {
1186	my ($self, $cb) = @_;	1669	my ($self, $cb) = @_;
1187		1670
1188	require JSON;	1671	my $json = $self->{json} ||= json_coder;
1189		1672
1190	my $data;	1673	my $data;
1191	my $rbuf = \$self->{rbuf};	1674	my $rbuf = \$self->{rbuf};
1192		1675
1193	my $json = $self->{json} ||= JSON->new->utf8;
1194
1195	sub {	1676	sub {
1196	my $ref = eval { $json->incr_parse ($self->{rbuf}) };	1677	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1197		1678
1198	if ($ref) {	1679	if ($ref) {
1199	$self->{rbuf} = $json->incr_text;	1680	$_[0]{rbuf} = $json->incr_text;
1200	$json->incr_text = "";	1681	$json->incr_text = "";
1201	$cb->($self, $ref);	1682	$cb->($_[0], $ref);
1202		1683
1203	1	1684	1
1204	} elsif ($@) {	1685	} elsif ($@) {
1205	# error case	1686	# error case
1206	$json->incr_skip;	1687	$json->incr_skip;
1207		1688
1208	$self->{rbuf} = $json->incr_text;	1689	$_[0]{rbuf} = $json->incr_text;
1209	$json->incr_text = "";	1690	$json->incr_text = "";
1210		1691
1211	$self->_error (&Errno::EBADMSG);	1692	$_[0]->_error (Errno::EBADMSG);
1212		1693
1213	()	1694	()
1214	} else {	1695	} else {
1215	$self->{rbuf} = "";	1696	$_[0]{rbuf} = "";
1216		1697
1217	()	1698	()
1218	}	1699	}
1219	}	1700	}
1220	};	1701	};
…		…
1230	=cut	1711	=cut
1231		1712
1232	register_read_type storable => sub {	1713	register_read_type storable => sub {
1233	my ($self, $cb) = @_;	1714	my ($self, $cb) = @_;
1234		1715
1235	require Storable;	1716	require Storable unless $Storable::VERSION;
1236		1717
1237	sub {	1718	sub {
1238	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method	1719	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1239	defined (my $len = eval { unpack "w", $_[0]{rbuf} })	1720	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1240	or return;	1721	or return;
…		…
1253	# read remaining chunk	1734	# read remaining chunk
1254	$_[0]->unshift_read (chunk => $len, sub {	1735	$_[0]->unshift_read (chunk => $len, sub {
1255	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1736	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1256	$cb->($_[0], $ref);	1737	$cb->($_[0], $ref);
1257	} else {	1738	} else {
1258	$self->_error (&Errno::EBADMSG);	1739	$_[0]->_error (Errno::EBADMSG);
1259	}	1740	}
1260	});	1741	});
1261	}	1742	}
1262		1743
1263	1	1744	1
1264	}	1745	}
1265	};	1746	};
1266		1747
1267	=back	1748	=back
1268		1749
1269	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1750	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1270		1751
1271	This function (not method) lets you add your own types to C<push_read>.	1752	Instead of one of the predefined types, you can also specify the name
		1753	of a package. AnyEvent will try to load the package and then expects to
		1754	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1755	progressively tries to load the parent package until it either finds the
		1756	function (good) or runs out of packages (bad).
1272		1757
1273	Whenever the given C<type> is used, C<push_read> will invoke the code	1758	Whenever this type is used, C<push_read> will invoke the function with the
1274	reference with the handle object, the callback and the remaining	1759	handle object, the original callback and the remaining arguments.
1275	arguments.
1276		1760
1277	The code reference is supposed to return a callback (usually a closure)	1761	The function is supposed to return a callback (usually a closure) that
1278	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1762	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1763	mentally treat the function as a "configurable read type to read callback"
		1764	converter.
1279		1765
1280	It should invoke the passed callback when it is done reading (remember to	1766	It should invoke the original callback when it is done reading (remember
1281	pass C<$handle> as first argument as all other callbacks do that).	1767	to pass C<$handle> as first argument as all other callbacks do that,
		1768	although there is no strict requirement on this).
1282		1769
1283	Note that this is a function, and all types registered this way will be
1284	global, so try to use unique names.
1285
1286	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1770	For examples, see the source of this module (F<perldoc -m
1287	search for C<register_read_type>)).	1771	AnyEvent::Handle>, search for C<register_read_type>)).
1288		1772
1289	=item $handle->stop_read	1773	=item $handle->stop_read
1290		1774
1291	=item $handle->start_read	1775	=item $handle->start_read
1292		1776
…		…
1298	Note that AnyEvent::Handle will automatically C<start_read> for you when	1782	Note that AnyEvent::Handle will automatically C<start_read> for you when
1299	you change the C<on_read> callback or push/unshift a read callback, and it	1783	you change the C<on_read> callback or push/unshift a read callback, and it
1300	will automatically C<stop_read> for you when neither C<on_read> is set nor	1784	will automatically C<stop_read> for you when neither C<on_read> is set nor
1301	there are any read requests in the queue.	1785	there are any read requests in the queue.
1302		1786
1303	These methods will have no effect when in TLS mode (as TLS doesn't support	1787	In older versions of this module (<= 5.3), these methods had no effect,
1304	half-duplex connections).	1788	as TLS does not support half-duplex connections. In current versions they
		1789	work as expected, as this behaviour is required to avoid certain resource
		1790	attacks, where the program would be forced to read (and buffer) arbitrary
		1791	amounts of data before being able to send some data. The drawback is that
		1792	some readings of the the SSL/TLS specifications basically require this
		1793	attack to be working, as SSL/TLS implementations might stall sending data
		1794	during a rehandshake.
		1795
		1796	As a guideline, during the initial handshake, you should not stop reading,
		1797	and as a client, it might cause problems, depending on your application.
1305		1798
1306	=cut	1799	=cut
1307		1800
1308	sub stop_read {	1801	sub stop_read {
1309	my ($self) = @_;	1802	my ($self) = @_;
1310		1803
1311	delete $self->{_rw} unless $self->{tls};	1804	delete $self->{_rw};
1312	}	1805	}
1313		1806
1314	sub start_read {	1807	sub start_read {
1315	my ($self) = @_;	1808	my ($self) = @_;
1316		1809
1317	unless ($self->{_rw} || $self->{_eof}) {	1810	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1318	Scalar::Util::weaken $self;	1811	Scalar::Util::weaken $self;
1319		1812
1320	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1813	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1321	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});	1814	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1322	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1815	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1323		1816
1324	if ($len > 0) {	1817	if ($len > 0) {
1325	$self->{_activity} = AnyEvent->now;	1818	$self->{_activity} = $self->{_ractivity} = AE::now;
1326		1819
1327	if ($self->{tls}) {	1820	if ($self->{tls}) {
1328	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);	1821	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1329		1822
1330	&_dotls ($self);	1823	&_dotls ($self);
1331	} else {	1824	} else {
1332	$self->_drain_rbuf unless $self->{_in_drain};	1825	$self->_drain_rbuf;
		1826	}
		1827
		1828	if ($len == $self->{read_size}) {
		1829	$self->{read_size} *= 2;
		1830	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1831	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1333	}	1832	}
1334		1833
1335	} elsif (defined $len) {	1834	} elsif (defined $len) {
1336	delete $self->{_rw};	1835	delete $self->{_rw};
1337	$self->{_eof} = 1;	1836	$self->{_eof} = 1;
1338	$self->_drain_rbuf unless $self->{_in_drain};	1837	$self->_drain_rbuf;
1339		1838
1340	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1839	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1341	return $self->_error ($!, 1);	1840	return $self->_error ($!, 1);
1342	}	1841	}
1343	});	1842	};
		1843	}
		1844	}
		1845
		1846	our $ERROR_SYSCALL;
		1847	our $ERROR_WANT_READ;
		1848
		1849	sub _tls_error {
		1850	my ($self, $err) = @_;
		1851
		1852	return $self->_error ($!, 1)
		1853	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1854
		1855	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1856
		1857	# reduce error string to look less scary
		1858	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1859
		1860	if ($self->{_on_starttls}) {
		1861	(delete $self->{_on_starttls})->($self, undef, $err);
		1862	&_freetls;
		1863	} else {
		1864	&_freetls;
		1865	$self->_error (Errno::EPROTO, 1, $err);
1344	}	1866	}
1345	}	1867	}
1346		1868
1347	# poll the write BIO and send the data if applicable	1869	# poll the write BIO and send the data if applicable
		1870	# also decode read data if possible
		1871	# this is basiclaly our TLS state machine
		1872	# more efficient implementations are possible with openssl,
		1873	# but not with the buggy and incomplete Net::SSLeay.
1348	sub _dotls {	1874	sub _dotls {
1349	my ($self) = @_;	1875	my ($self) = @_;
1350		1876
1351	my $tmp;	1877	my $tmp;
1352		1878
1353	if (length $self->{_tls_wbuf}) {	1879	if (length $self->{_tls_wbuf}) {
1354	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1880	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1355	substr $self->{_tls_wbuf}, 0, $tmp, "";	1881	substr $self->{_tls_wbuf}, 0, $tmp, "";
1356	}	1882	}
		1883
		1884	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1885	return $self->_tls_error ($tmp)
		1886	if $tmp != $ERROR_WANT_READ
		1887	&& ($tmp != $ERROR_SYSCALL || $!);
1357	}	1888	}
1358		1889
1359	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {	1890	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1360	unless (length $tmp) {	1891	unless (length $tmp) {
1361	# let's treat SSL-eof as we treat normal EOF	1892	$self->{_on_starttls}
1362	delete $self->{_rw};	1893	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1363	$self->{_eof} = 1;
1364	&_freetls;	1894	&_freetls;
		1895
		1896	if ($self->{on_stoptls}) {
		1897	$self->{on_stoptls}($self);
		1898	return;
		1899	} else {
		1900	# let's treat SSL-eof as we treat normal EOF
		1901	delete $self->{_rw};
		1902	$self->{_eof} = 1;
		1903	}
1365	}	1904	}
1366		1905
1367	$self->{_tls_rbuf} .= $tmp;	1906	$self->{_tls_rbuf} .= $tmp;
1368	$self->_drain_rbuf unless $self->{_in_drain};	1907	$self->_drain_rbuf;
1369	$self->{tls} or return; # tls session might have gone away in callback	1908	$self->{tls} or return; # tls session might have gone away in callback
1370	}	1909	}
1371		1910
1372	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);	1911	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1373
1374	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1375	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1376	return $self->_error ($!, 1);	1912	return $self->_tls_error ($tmp)
1377	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {	1913	if $tmp != $ERROR_WANT_READ
1378	return $self->_error (&Errno::EIO, 1);	1914	&& ($tmp != $ERROR_SYSCALL || $!);
1379	}
1380
1381	# all other errors are fine for our purposes
1382	}
1383		1915
1384	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1916	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1385	$self->{wbuf} .= $tmp;	1917	$self->{wbuf} .= $tmp;
1386	$self->_drain_wbuf;	1918	$self->_drain_wbuf;
		1919	$self->{tls} or return; # tls session might have gone away in callback
1387	}	1920	}
		1921
		1922	$self->{_on_starttls}
		1923	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1924	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1388	}	1925	}
1389		1926
1390	=item $handle->starttls ($tls[, $tls_ctx])	1927	=item $handle->starttls ($tls[, $tls_ctx])
1391		1928
1392	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1929	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1393	object is created, you can also do that at a later time by calling	1930	object is created, you can also do that at a later time by calling
1394	C<starttls>.	1931	C<starttls>.
		1932
		1933	Starting TLS is currently an asynchronous operation - when you push some
		1934	write data and then call C<< ->starttls >> then TLS negotiation will start
		1935	immediately, after which the queued write data is then sent.
1395		1936
1396	The first argument is the same as the C<tls> constructor argument (either	1937	The first argument is the same as the C<tls> constructor argument (either
1397	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1938	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1398		1939
1399	The second argument is the optional C<AnyEvent::TLS> object that is used	1940	The second argument is the optional C<AnyEvent::TLS> object that is used
…		…
1404	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS	1945	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1405	context in C<< $handle->{tls_ctx} >> after this call and can be used or	1946	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1406	changed to your liking. Note that the handshake might have already started	1947	changed to your liking. Note that the handshake might have already started
1407	when this function returns.	1948	when this function returns.
1408		1949
1409	If it an error to start a TLS handshake more than once per	1950	Due to bugs in OpenSSL, it might or might not be possible to do multiple
1410	AnyEvent::Handle object (this is due to bugs in OpenSSL).	1951	handshakes on the same stream. It is best to not attempt to use the
		1952	stream after stopping TLS.
1411		1953
		1954	This method may invoke callbacks (and therefore the handle might be
		1955	destroyed after it returns).
		1956
1412	=cut	1957	=cut
		1958
		1959	our %TLS_CACHE; #TODO not yet documented, should we?
1413		1960
1414	sub starttls {	1961	sub starttls {
1415	my ($self, $ssl, $ctx) = @_;	1962	my ($self, $tls, $ctx) = @_;
		1963
		1964	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1965	if $self->{tls};
		1966
		1967	$self->{tls} = $tls;
		1968	$self->{tls_ctx} = $ctx if @_ > 2;
		1969
		1970	return unless $self->{fh};
1416		1971
1417	require Net::SSLeay;	1972	require Net::SSLeay;
1418		1973
1419	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"	1974	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1420	if $self->{tls};	1975	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1421		1976
		1977	$tls = delete $self->{tls};
1422	$ctx ||= $self->{tls_ctx};	1978	$ctx = $self->{tls_ctx};
		1979
		1980	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1423		1981
1424	if ("HASH" eq ref $ctx) {	1982	if ("HASH" eq ref $ctx) {
1425	require AnyEvent::TLS;	1983	require AnyEvent::TLS;
1426		1984
1427	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context	1985	if ($ctx->{cache}) {
		1986	my $key = $ctx+0;
		1987	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1988	} else {
1428	$ctx = new AnyEvent::TLS %$ctx;	1989	$ctx = new AnyEvent::TLS %$ctx;
		1990	}
1429	}	1991	}
1430		1992
1431	$self->{tls_ctx} = $ctx || TLS_CTX ();	1993	$self->{tls_ctx} = $ctx || TLS_CTX ();
1432	$self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self);	1994	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1433		1995
1434	# basically, this is deep magic (because SSL_read should have the same issues)	1996	# basically, this is deep magic (because SSL_read should have the same issues)
1435	# but the openssl maintainers basically said: "trust us, it just works".	1997	# but the openssl maintainers basically said: "trust us, it just works".
1436	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1998	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1437	# and mismaintained ssleay-module doesn't even offer them).	1999	# and mismaintained ssleay-module doesn't even offer them).
…		…
1444	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to	2006	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1445	# have identity issues in that area.	2007	# have identity issues in that area.
1446	# Net::SSLeay::CTX_set_mode ($ssl,	2008	# Net::SSLeay::CTX_set_mode ($ssl,
1447	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2009	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1448	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2010	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1449	Net::SSLeay::CTX_set_mode ($ssl, 1|2);	2011	Net::SSLeay::CTX_set_mode ($tls, 1|2);
1450		2012
1451	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1452	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2014	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1453		2015
		2016	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2017	$self->{rbuf} = "";
		2018
1454	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2019	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		2020
		2021	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		2022	if $self->{on_starttls};
1455		2023
1456	&_dotls; # need to trigger the initial handshake	2024	&_dotls; # need to trigger the initial handshake
1457	$self->start_read; # make sure we actually do read	2025	$self->start_read; # make sure we actually do read
1458	}	2026	}
1459		2027
1460	=item $handle->stoptls	2028	=item $handle->stoptls
1461		2029
1462	Shuts down the SSL connection - this makes a proper EOF handshake by	2030	Shuts down the SSL connection - this makes a proper EOF handshake by
1463	sending a close notify to the other side, but since OpenSSL doesn't	2031	sending a close notify to the other side, but since OpenSSL doesn't
1464	support non-blocking shut downs, it is not possible to re-use the stream	2032	support non-blocking shut downs, it is not guaranteed that you can re-use
1465	afterwards.	2033	the stream afterwards.
		2034
		2035	This method may invoke callbacks (and therefore the handle might be
		2036	destroyed after it returns).
1466		2037
1467	=cut	2038	=cut
1468		2039
1469	sub stoptls {	2040	sub stoptls {
1470	my ($self) = @_;	2041	my ($self) = @_;
1471		2042
1472	if ($self->{tls}) {	2043	if ($self->{tls} && $self->{fh}) {
1473	Net::SSLeay::shutdown ($self->{tls});	2044	Net::SSLeay::shutdown ($self->{tls});
1474		2045
1475	&_dotls;	2046	&_dotls;
1476		2047
1477	# we don't give a shit. no, we do, but we can't. no...	2048	# # we don't give a shit. no, we do, but we can't. no...#d#
1478	# we, we... have to use openssl :/	2049	# # we, we... have to use openssl :/#d#
1479	&_freetls;	2050	# &_freetls;#d#
1480	}	2051	}
1481	}	2052	}
1482		2053
1483	sub _freetls {	2054	sub _freetls {
1484	my ($self) = @_;	2055	my ($self) = @_;
1485		2056
1486	return unless $self->{tls};	2057	return unless $self->{tls};
1487		2058
1488	$self->{tls_ctx}->_put_session (delete $self->{tls});	2059	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2060	if $self->{tls} > 0;
1489		2061
1490	delete @$self{qw(_rbio _wbio _tls_wbuf)};	2062	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1491	}	2063	}
		2064
		2065	=item $handle->resettls
		2066
		2067	This rarely-used method simply resets and TLS state on the handle, usually
		2068	causing data loss.
		2069
		2070	One case where it may be useful is when you want to skip over the data in
		2071	the stream but you are not interested in interpreting it, so data loss is
		2072	no concern.
		2073
		2074	=cut
		2075
		2076	*resettls = \&_freetls;
1492		2077
1493	sub DESTROY {	2078	sub DESTROY {
1494	my ($self) = @_;	2079	my ($self) = @_;
1495		2080
1496	&_freetls;	2081	&_freetls;
1497		2082
1498	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2083	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1499		2084
1500	if ($linger && length $self->{wbuf}) {	2085	if ($linger && length $self->{wbuf} && $self->{fh}) {
1501	my $fh = delete $self->{fh};	2086	my $fh = delete $self->{fh};
1502	my $wbuf = delete $self->{wbuf};	2087	my $wbuf = delete $self->{wbuf};
1503		2088
1504	my @linger;	2089	my @linger;
1505		2090
1506	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2091	push @linger, AE::io $fh, 1, sub {
1507	my $len = syswrite $fh, $wbuf, length $wbuf;	2092	my $len = syswrite $fh, $wbuf, length $wbuf;
1508		2093
1509	if ($len > 0) {	2094	if ($len > 0) {
1510	substr $wbuf, 0, $len, "";	2095	substr $wbuf, 0, $len, "";
1511	} else {	2096	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1512	@linger = (); # end	2097	@linger = (); # end
1513	}	2098	}
1514	});	2099	};
1515	push @linger, AnyEvent->timer (after => $linger, cb => sub {	2100	push @linger, AE::timer $linger, 0, sub {
1516	@linger = ();	2101	@linger = ();
1517	});	2102	};
1518	}	2103	}
1519	}	2104	}
1520		2105
1521	=item $handle->destroy	2106	=item $handle->destroy
1522		2107
1523	Shuts down the handle object as much as possible - this call ensures that	2108	Shuts down the handle object as much as possible - this call ensures that
1524	no further callbacks will be invoked and resources will be freed as much	2109	no further callbacks will be invoked and as many resources as possible
1525	as possible. You must not call any methods on the object afterwards.	2110	will be freed. Any method you will call on the handle object after
		2111	destroying it in this way will be silently ignored (and it will return the
		2112	empty list).
1526		2113
1527	Normally, you can just "forget" any references to an AnyEvent::Handle	2114	Normally, you can just "forget" any references to an AnyEvent::Handle
1528	object and it will simply shut down. This works in fatal error and EOF	2115	object and it will simply shut down. This works in fatal error and EOF
1529	callbacks, as well as code outside. It does I<NOT> work in a read or write	2116	callbacks, as well as code outside. It does I<NOT> work in a read or write
1530	callback, so when you want to destroy the AnyEvent::Handle object from	2117	callback, so when you want to destroy the AnyEvent::Handle object from
1531	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in	2118	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1532	that case.	2119	that case.
1533		2120
		2121	Destroying the handle object in this way has the advantage that callbacks
		2122	will be removed as well, so if those are the only reference holders (as
		2123	is common), then one doesn't need to do anything special to break any
		2124	reference cycles.
		2125
1534	The handle might still linger in the background and write out remaining	2126	The handle might still linger in the background and write out remaining
1535	data, as specified by the C<linger> option, however.	2127	data, as specified by the C<linger> option, however.
1536		2128
1537	=cut	2129	=cut
1538		2130
1539	sub destroy {	2131	sub destroy {
1540	my ($self) = @_;	2132	my ($self) = @_;
1541		2133
1542	$self->DESTROY;	2134	$self->DESTROY;
1543	%$self = ();	2135	%$self = ();
		2136	bless $self, "AnyEvent::Handle::destroyed";
1544	}	2137	}
		2138
		2139	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2140	#nop
		2141	}
		2142
		2143	=item $handle->destroyed
		2144
		2145	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2146	->destroy >>, true otherwise.
		2147
		2148	Can be useful to decide whether the handle is still valid after some
		2149	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2150	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2151	can destroy the handle, so work can be avoided by checking sometimes:
		2152
		2153	$hdl->starttls ("accept");
		2154	return if $hdl->destroyed;
		2155	$hdl->push_write (...
		2156
		2157	Note that the call to C<push_write> will silently be ignored if the handle
		2158	has been destroyed, so often you can just ignore the possibility of the
		2159	handle being destroyed.
		2160
		2161	=cut
		2162
		2163	sub destroyed { 0 }
		2164	sub AnyEvent::Handle::destroyed::destroyed { 1 }
1545		2165
1546	=item AnyEvent::Handle::TLS_CTX	2166	=item AnyEvent::Handle::TLS_CTX
1547		2167
1548	This function creates and returns the AnyEvent::TLS object used by default	2168	This function creates and returns the AnyEvent::TLS object used by default
1549	for TLS mode.	2169	for TLS mode.
…		…
1577		2197
1578	It is only safe to "forget" the reference inside EOF or error callbacks,	2198	It is only safe to "forget" the reference inside EOF or error callbacks,
1579	from within all other callbacks, you need to explicitly call the C<<	2199	from within all other callbacks, you need to explicitly call the C<<
1580	->destroy >> method.	2200	->destroy >> method.
1581		2201
		2202	=item Why is my C<on_eof> callback never called?
		2203
		2204	Probably because your C<on_error> callback is being called instead: When
		2205	you have outstanding requests in your read queue, then an EOF is
		2206	considered an error as you clearly expected some data.
		2207
		2208	To avoid this, make sure you have an empty read queue whenever your handle
		2209	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2210	an C<on_read> handler that simply pushes the first read requests in the
		2211	queue.
		2212
		2213	See also the next question, which explains this in a bit more detail.
		2214
		2215	=item How can I serve requests in a loop?
		2216
		2217	Most protocols consist of some setup phase (authentication for example)
		2218	followed by a request handling phase, where the server waits for requests
		2219	and handles them, in a loop.
		2220
		2221	There are two important variants: The first (traditional, better) variant
		2222	handles requests until the server gets some QUIT command, causing it to
		2223	close the connection first (highly desirable for a busy TCP server). A
		2224	client dropping the connection is an error, which means this variant can
		2225	detect an unexpected detection close.
		2226
		2227	To handle this case, always make sure you have a on-empty read queue, by
		2228	pushing the "read request start" handler on it:
		2229
		2230	# we assume a request starts with a single line
		2231	my @start_request; @start_request = (line => sub {
		2232	my ($hdl, $line) = @_;
		2233
		2234	... handle request
		2235
		2236	# push next request read, possibly from a nested callback
		2237	$hdl->push_read (@start_request);
		2238	});
		2239
		2240	# auth done, now go into request handling loop
		2241	# now push the first @start_request
		2242	$hdl->push_read (@start_request);
		2243
		2244	By always having an outstanding C<push_read>, the handle always expects
		2245	some data and raises the C<EPIPE> error when the connction is dropped
		2246	unexpectedly.
		2247
		2248	The second variant is a protocol where the client can drop the connection
		2249	at any time. For TCP, this means that the server machine may run out of
		2250	sockets easier, and in general, it means you cannot distinguish a protocl
		2251	failure/client crash from a normal connection close. Nevertheless, these
		2252	kinds of protocols are common (and sometimes even the best solution to the
		2253	problem).
		2254
		2255	Having an outstanding read request at all times is possible if you ignore
		2256	C<EPIPE> errors, but this doesn't help with when the client drops the
		2257	connection during a request, which would still be an error.
		2258
		2259	A better solution is to push the initial request read in an C<on_read>
		2260	callback. This avoids an error, as when the server doesn't expect data
		2261	(i.e. is idly waiting for the next request, an EOF will not raise an
		2262	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2263	and simpler:
		2264
		2265	# auth done, now go into request handling loop
		2266	$hdl->on_read (sub {
		2267	my ($hdl) = @_;
		2268
		2269	# called each time we receive data but the read queue is empty
		2270	# simply start read the request
		2271
		2272	$hdl->push_read (line => sub {
		2273	my ($hdl, $line) = @_;
		2274
		2275	... handle request
		2276
		2277	# do nothing special when the request has been handled, just
		2278	# let the request queue go empty.
		2279	});
		2280	});
		2281
1582	=item I get different callback invocations in TLS mode/Why can't I pause	2282	=item I get different callback invocations in TLS mode/Why can't I pause
1583	reading?	2283	reading?
1584		2284
1585	Unlike, say, TCP, TLS connections do not consist of two independent	2285	Unlike, say, TCP, TLS connections do not consist of two independent
1586	communication channels, one for each direction. Or put differently. The	2286	communication channels, one for each direction. Or put differently, the
1587	read and write directions are not independent of each other: you cannot	2287	read and write directions are not independent of each other: you cannot
1588	write data unless you are also prepared to read, and vice versa.	2288	write data unless you are also prepared to read, and vice versa.
1589		2289
1590	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>	2290	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
1591	callback invocations when you are not expecting any read data - the reason	2291	callback invocations when you are not expecting any read data - the reason
1592	is that AnyEvent::Handle always reads in TLS mode.	2292	is that AnyEvent::Handle always reads in TLS mode.
1593		2293
1594	During the connection, you have to make sure that you always have a	2294	During the connection, you have to make sure that you always have a
1595	non-empty read-queue, or an C<on_read> watcher. At the end of the	2295	non-empty read-queue, or an C<on_read> watcher. At the end of the
…		…
1605		2305
1606	$handle->on_read (sub { });	2306	$handle->on_read (sub { });
1607	$handle->on_eof (undef);	2307	$handle->on_eof (undef);
1608	$handle->on_error (sub {	2308	$handle->on_error (sub {
1609	my $data = delete $_[0]{rbuf};	2309	my $data = delete $_[0]{rbuf};
1610	undef $handle;
1611	});	2310	});
		2311
		2312	Note that this example removes the C<rbuf> member from the handle object,
		2313	which is not normally allowed by the API. It is expressly permitted in
		2314	this case only, as the handle object needs to be destroyed afterwards.
1612		2315
1613	The reason to use C<on_error> is that TCP connections, due to latencies	2316	The reason to use C<on_error> is that TCP connections, due to latencies
1614	and packets loss, might get closed quite violently with an error, when in	2317	and packets loss, might get closed quite violently with an error, when in
1615	fact, all data has been received.	2318	fact all data has been received.
1616		2319
1617	It is usually better to use acknowledgements when transferring data,	2320	It is usually better to use acknowledgements when transferring data,
1618	to make sure the other side hasn't just died and you got the data	2321	to make sure the other side hasn't just died and you got the data
1619	intact. This is also one reason why so many internet protocols have an	2322	intact. This is also one reason why so many internet protocols have an
1620	explicit QUIT command.	2323	explicit QUIT command.
…		…
1627	C<low_water_mark> this will be called precisely when all data has been	2330	C<low_water_mark> this will be called precisely when all data has been
1628	written to the socket:	2331	written to the socket:
1629		2332
1630	$handle->push_write (...);	2333	$handle->push_write (...);
1631	$handle->on_drain (sub {	2334	$handle->on_drain (sub {
1632	warn "all data submitted to the kernel\n";	2335	AE::log debug => "all data submitted to the kernel\n";
1633	undef $handle;	2336	undef $handle;
1634	});	2337	});
		2338
		2339	If you just want to queue some data and then signal EOF to the other side,
		2340	consider using C<< ->push_shutdown >> instead.
		2341
		2342	=item I want to contact a TLS/SSL server, I don't care about security.
		2343
		2344	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2345	connect to it and then create the AnyEvent::Handle with the C<tls>
		2346	parameter:
		2347
		2348	tcp_connect $host, $port, sub {
		2349	my ($fh) = @_;
		2350
		2351	my $handle = new AnyEvent::Handle
		2352	fh => $fh,
		2353	tls => "connect",
		2354	on_error => sub { ... };
		2355
		2356	$handle->push_write (...);
		2357	};
		2358
		2359	=item I want to contact a TLS/SSL server, I do care about security.
		2360
		2361	Then you should additionally enable certificate verification, including
		2362	peername verification, if the protocol you use supports it (see
		2363	L<AnyEvent::TLS>, C<verify_peername>).
		2364
		2365	E.g. for HTTPS:
		2366
		2367	tcp_connect $host, $port, sub {
		2368	my ($fh) = @_;
		2369
		2370	my $handle = new AnyEvent::Handle
		2371	fh => $fh,
		2372	peername => $host,
		2373	tls => "connect",
		2374	tls_ctx => { verify => 1, verify_peername => "https" },
		2375	...
		2376
		2377	Note that you must specify the hostname you connected to (or whatever
		2378	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2379	peername verification will be done.
		2380
		2381	The above will use the system-dependent default set of trusted CA
		2382	certificates. If you want to check against a specific CA, add the
		2383	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2384
		2385	tls_ctx => {
		2386	verify => 1,
		2387	verify_peername => "https",
		2388	ca_file => "my-ca-cert.pem",
		2389	},
		2390
		2391	=item I want to create a TLS/SSL server, how do I do that?
		2392
		2393	Well, you first need to get a server certificate and key. You have
		2394	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2395	self-signed certificate (cheap. check the search engine of your choice,
		2396	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2397	nice program for that purpose).
		2398
		2399	Then create a file with your private key (in PEM format, see
		2400	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2401	file should then look like this:
		2402
		2403	-----BEGIN RSA PRIVATE KEY-----
		2404	...header data
		2405	... lots of base64'y-stuff
		2406	-----END RSA PRIVATE KEY-----
		2407
		2408	-----BEGIN CERTIFICATE-----
		2409	... lots of base64'y-stuff
		2410	-----END CERTIFICATE-----
		2411
		2412	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2413	specify this file as C<cert_file>:
		2414
		2415	tcp_server undef, $port, sub {
		2416	my ($fh) = @_;
		2417
		2418	my $handle = new AnyEvent::Handle
		2419	fh => $fh,
		2420	tls => "accept",
		2421	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2422	...
		2423
		2424	When you have intermediate CA certificates that your clients might not
		2425	know about, just append them to the C<cert_file>.
1635		2426
1636	=back	2427	=back
1637		2428
1638		2429
1639	=head1 SUBCLASSING AnyEvent::Handle	2430	=head1 SUBCLASSING AnyEvent::Handle
…		…
1659		2450
1660	=item * all members not documented here and not prefixed with an underscore	2451	=item * all members not documented here and not prefixed with an underscore
1661	are free to use in subclasses.	2452	are free to use in subclasses.
1662		2453
1663	Of course, new versions of AnyEvent::Handle may introduce more "public"	2454	Of course, new versions of AnyEvent::Handle may introduce more "public"
1664	member variables, but thats just life, at least it is documented.	2455	member variables, but that's just life. At least it is documented.
1665		2456
1666	=back	2457	=back
1667		2458
1668	=head1 AUTHOR	2459	=head1 AUTHOR
1669		2460

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