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Revision 1.232 by root, Fri Mar 30 03:11:17 2012 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict;
5
6	use AnyEvent ();
7	use AnyEvent::Util qw(WSAEAGAIN);
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 = '0.04';
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $handle =	12	my $hdl; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
32	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
33	},	16	AE::log error => "Got error $msg!";
		17	$hdl->destroy;
		18	$cv->send;
34	);	19	};
35		20
36	# send some request line	21	# send some request line
37	$handle->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
38		23
39	# read the response line	24	# read the response line
40	$handle->push_read (line => sub {	25	$hdl->push_read (line => sub {
41	my ($handle, $line) = @_;	26	my ($hdl, $line) = @_;
42	warn "read line <$line>\n";	27	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
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
54	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
55	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
56	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
57		47
58	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
59	argument.	49	argument.
60		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
61	=head1 METHODS	82	=head1 METHODS
62		83
63	=over 4	84	=over 4
64		85
65	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66		87
67	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
68		89
69	=over 4	90	=over 4
70		91
71	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72		93
73	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
74
75	NOTE: The filehandle will be set to non-blocking (using	95	NOTE: The filehandle will be set to non-blocking mode (using
76	AnyEvent::Util::fh_nonblocking).	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		97	that mode.
77		98
78	=item on_eof => $cb->($self)	99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
79		100
80	Set the callback to be called on EOF.	101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
81		104
82	While not mandatory, it is highly recommended to set an eof callback,	105	You have to specify either this parameter, or C<fh>, above.
83	otherwise you might end up with a closed socket while you are still
84	waiting for data.
85		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
86	=item on_error => $cb->($self)	116	=item on_prepare => $cb->($handle)
87		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, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback. At the time it is called the
		134	read and write queues, EOF status, TLS status and similar properties of
		135	the handle will have been reset.
		136
		137	It is not allowed to use the read or write queues while the handle object
		138	is connecting.
		139
		140	If, for some reason, the handle is not acceptable, calling C<$retry> will
		141	continue with the next connection target (in case of multi-homed hosts or
		142	SRV records there can be multiple connection endpoints). The C<$retry>
		143	callback can be invoked after the connect callback returns, i.e. one can
		144	start a handshake and then decide to retry with the next host if the
		145	handshake fails.
		146
		147	In most cases, you should ignore the C<$retry> parameter.
		148
		149	=item on_connect_error => $cb->($handle, $message)
		150
		151	This callback is called when the connection could not be
		152	established. C<$!> will contain the relevant error code, and C<$message> a
		153	message describing it (usually the same as C<"$!">).
		154
		155	If this callback isn't specified, then C<on_error> will be called with a
		156	fatal error instead.
		157
		158	=back
		159
		160	=item on_error => $cb->($handle, $fatal, $message)
		161
88	This is the fatal error callback, that is called when, well, a fatal error	162	This is the error callback, which is called when, well, some error
89	occurs, such as not being able to resolve the hostname, failure to connect	163	occured, such as not being able to resolve the hostname, failure to
90	or a read error.	164	connect, or a read error.
91		165
92	The object will not be in a usable state when this callback has been	166	Some errors are fatal (which is indicated by C<$fatal> being true). On
93	called.	167	fatal errors the handle object will be destroyed (by a call to C<< ->
		168	destroy >>) after invoking the error callback (which means you are free to
		169	examine the handle object). Examples of fatal errors are an EOF condition
		170	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		171	cases where the other side can close the connection at will, it is
		172	often easiest to not report C<EPIPE> errors in this callback.
94		173
		174	AnyEvent::Handle tries to find an appropriate error code for you to check
		175	against, but in some cases (TLS errors), this does not work well. It is
		176	recommended to always output the C<$message> argument in human-readable
		177	error messages (it's usually the same as C<"$!">).
		178
		179	Non-fatal errors can be retried by returning, but it is recommended
		180	to simply ignore this parameter and instead abondon the handle object
		181	when this callback is invoked. Examples of non-fatal errors are timeouts
		182	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		183
95	On callback entrance, the value of C<$!> contains the operating system	184	On entry to the callback, the value of C<$!> contains the operating
96	error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>).	185	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		186	C<EPROTO>).
97		187
98	While not mandatory, it is I<highly> recommended to set this callback, as	188	While not mandatory, it is I<highly> recommended to set this callback, as
99	you will not be notified of errors otherwise. The default simply calls	189	you will not be notified of errors otherwise. The default just calls
100	die.	190	C<croak>.
101		191
102	=item on_read => $cb->($self)	192	=item on_read => $cb->($handle)
103		193
104	This sets the default read callback, which is called when data arrives	194	This sets the default read callback, which is called when data arrives
105	and no read request is in the queue.	195	and no read request is in the queue (unlike read queue callbacks, this
		196	callback will only be called when at least one octet of data is in the
		197	read buffer).
106		198
107	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	199	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108	method or access the C<$self->{rbuf}> member directly.	200	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		201	must not enlarge or modify the read buffer, you can only remove data at
		202	the beginning from it.
109		203
		204	You can also call C<< ->push_read (...) >> or any other function that
		205	modifies the read queue. Or do both. Or ...
		206
110	When an EOF condition is detected then AnyEvent::Handle will first try to	207	When an EOF condition is detected, AnyEvent::Handle will first try to
111	feed all the remaining data to the queued callbacks and C<on_read> before	208	feed all the remaining data to the queued callbacks and C<on_read> before
112	calling the C<on_eof> callback. If no progress can be made, then a fatal	209	calling the C<on_eof> callback. If no progress can be made, then a fatal
113	error will be raised (with C<$!> set to C<EPIPE>).	210	error will be raised (with C<$!> set to C<EPIPE>).
114		211
		212	Note that, unlike requests in the read queue, an C<on_read> callback
		213	doesn't mean you I<require> some data: if there is an EOF and there
		214	are outstanding read requests then an error will be flagged. With an
		215	C<on_read> callback, the C<on_eof> callback will be invoked.
		216
		217	=item on_eof => $cb->($handle)
		218
		219	Set the callback to be called when an end-of-file condition is detected,
		220	i.e. in the case of a socket, when the other side has closed the
		221	connection cleanly, and there are no outstanding read requests in the
		222	queue (if there are read requests, then an EOF counts as an unexpected
		223	connection close and will be flagged as an error).
		224
		225	For sockets, this just means that the other side has stopped sending data,
		226	you can still try to write data, and, in fact, one can return from the EOF
		227	callback and continue writing data, as only the read part has been shut
		228	down.
		229
		230	If an EOF condition has been detected but no C<on_eof> callback has been
		231	set, then a fatal error will be raised with C<$!> set to <0>.
		232
115	=item on_drain => $cb->()	233	=item on_drain => $cb->($handle)
116		234
117	This sets the callback that is called when the write buffer becomes empty	235	This sets the callback that is called once when the write buffer becomes
118	(or when the callback is set and the buffer is empty already).	236	empty (and immediately when the handle object is created).
119		237
120	To append to the write buffer, use the C<< ->push_write >> method.	238	To append to the write buffer, use the C<< ->push_write >> method.
		239
		240	This callback is useful when you don't want to put all of your write data
		241	into the queue at once, for example, when you want to write the contents
		242	of some file to the socket you might not want to read the whole file into
		243	memory and push it into the queue, but instead only read more data from
		244	the file when the write queue becomes empty.
		245
		246	=item timeout => $fractional_seconds
		247
		248	=item rtimeout => $fractional_seconds
		249
		250	=item wtimeout => $fractional_seconds
		251
		252	If non-zero, then these enables an "inactivity" timeout: whenever this
		253	many seconds pass without a successful read or write on the underlying
		254	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		255	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		256	error will be raised).
		257
		258	There are three variants of the timeouts that work independently of each
		259	other, for both read and write (triggered when nothing was read I<OR>
		260	written), just read (triggered when nothing was read), and just write:
		261	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		262	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		263	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		264
		265	Note that timeout processing is active even when you do not have any
		266	outstanding read or write requests: If you plan to keep the connection
		267	idle then you should disable the timeout temporarily or ignore the
		268	timeout in the corresponding C<on_timeout> callback, in which case
		269	AnyEvent::Handle will simply restart the timeout.
		270
		271	Zero (the default) disables the corresponding timeout.
		272
		273	=item on_timeout => $cb->($handle)
		274
		275	=item on_rtimeout => $cb->($handle)
		276
		277	=item on_wtimeout => $cb->($handle)
		278
		279	Called whenever the inactivity timeout passes. If you return from this
		280	callback, then the timeout will be reset as if some activity had happened,
		281	so this condition is not fatal in any way.
121		282
122	=item rbuf_max => <bytes>	283	=item rbuf_max => <bytes>
123		284
124	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	285	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125	when the read buffer ever (strictly) exceeds this size. This is useful to	286	when the read buffer ever (strictly) exceeds this size. This is useful to
126	avoid denial-of-service attacks.	287	avoid some forms of denial-of-service attacks.
127		288
128	For example, a server accepting connections from untrusted sources should	289	For example, a server accepting connections from untrusted sources should
129	be configured to accept only so-and-so much data that it cannot act on	290	be configured to accept only so-and-so much data that it cannot act on
130	(for example, when expecting a line, an attacker could send an unlimited	291	(for example, when expecting a line, an attacker could send an unlimited
131	amount of data without a callback ever being called as long as the line	292	amount of data without a callback ever being called as long as the line
132	isn't finished).	293	isn't finished).
133		294
		295	=item wbuf_max => <bytes>
		296
		297	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		298	when the write buffer ever (strictly) exceeds this size. This is useful to
		299	avoid some forms of denial-of-service attacks.
		300
		301	Although the units of this parameter is bytes, this is the I<raw> number
		302	of bytes not yet accepted by the kernel. This can make a difference when
		303	you e.g. use TLS, as TLS typically makes your write data larger (but it
		304	can also make it smaller due to compression).
		305
		306	As an example of when this limit is useful, take a chat server that sends
		307	chat messages to a client. If the client does not read those in a timely
		308	manner then the send buffer in the server would grow unbounded.
		309
		310	=item autocork => <boolean>
		311
		312	When disabled (the default), C<push_write> will try to immediately
		313	write the data to the handle if possible. This avoids having to register
		314	a write watcher and wait for the next event loop iteration, but can
		315	be inefficient if you write multiple small chunks (on the wire, this
		316	disadvantage is usually avoided by your kernel's nagle algorithm, see
		317	C<no_delay>, but this option can save costly syscalls).
		318
		319	When enabled, writes will always be queued till the next event loop
		320	iteration. This is efficient when you do many small writes per iteration,
		321	but less efficient when you do a single write only per iteration (or when
		322	the write buffer often is full). It also increases write latency.
		323
		324	=item no_delay => <boolean>
		325
		326	When doing small writes on sockets, your operating system kernel might
		327	wait a bit for more data before actually sending it out. This is called
		328	the Nagle algorithm, and usually it is beneficial.
		329
		330	In some situations you want as low a delay as possible, which can be
		331	accomplishd by setting this option to a true value.
		332
		333	The default is your operating system's default behaviour (most likely
		334	enabled). This option explicitly enables or disables it, if possible.
		335
		336	=item keepalive => <boolean>
		337
		338	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		339	normally, TCP connections have no time-out once established, so TCP
		340	connections, once established, can stay alive forever even when the other
		341	side has long gone. TCP keepalives are a cheap way to take down long-lived
		342	TCP connections when the other side becomes unreachable. While the default
		343	is OS-dependent, TCP keepalives usually kick in after around two hours,
		344	and, if the other side doesn't reply, take down the TCP connection some 10
		345	to 15 minutes later.
		346
		347	It is harmless to specify this option for file handles that do not support
		348	keepalives, and enabling it on connections that are potentially long-lived
		349	is usually a good idea.
		350
		351	=item oobinline => <boolean>
		352
		353	BSD majorly fucked up the implementation of TCP urgent data. The result
		354	is that almost no OS implements TCP according to the specs, and every OS
		355	implements it slightly differently.
		356
		357	If you want to handle TCP urgent data, then setting this flag (the default
		358	is enabled) gives you the most portable way of getting urgent data, by
		359	putting it into the stream.
		360
		361	Since BSD emulation of OOB data on top of TCP's urgent data can have
		362	security implications, AnyEvent::Handle sets this flag automatically
		363	unless explicitly specified. Note that setting this flag after
		364	establishing a connection I<may> be a bit too late (data loss could
		365	already have occured on BSD systems), but at least it will protect you
		366	from most attacks.
		367
134	=item read_size => <bytes>	368	=item read_size => <bytes>
135		369
136	The default read block size (the amount of bytes this module will try to read	370	The initial read block size, the number of bytes this module will try
137	on each [loop iteration). Default: C<4096>.	371	to read during each loop iteration. Each handle object will consume
		372	at least this amount of memory for the read buffer as well, so when
		373	handling many connections watch out for memory requirements). See also
		374	C<max_read_size>. Default: C<2048>.
		375
		376	=item max_read_size => <bytes>
		377
		378	The maximum read buffer size used by the dynamic adjustment
		379	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		380	one go it will double C<read_size> up to the maximum given by this
		381	option. Default: C<131072> or C<read_size>, whichever is higher.
138		382
139	=item low_water_mark => <bytes>	383	=item low_water_mark => <bytes>
140		384
141	Sets the amount of bytes (default: C<0>) that make up an "empty" write	385	Sets the number of bytes (default: C<0>) that make up an "empty" write
142	buffer: If the write reaches this size or gets even samller it is	386	buffer: If the buffer reaches this size or gets even samller it is
143	considered empty.	387	considered empty.
144		388
		389	Sometimes it can be beneficial (for performance reasons) to add data to
		390	the write buffer before it is fully drained, but this is a rare case, as
		391	the operating system kernel usually buffers data as well, so the default
		392	is good in almost all cases.
		393
		394	=item linger => <seconds>
		395
		396	If this is non-zero (default: C<3600>), the destructor of the
		397	AnyEvent::Handle object will check whether there is still outstanding
		398	write data and will install a watcher that will write this data to the
		399	socket. No errors will be reported (this mostly matches how the operating
		400	system treats outstanding data at socket close time).
		401
		402	This will not work for partial TLS data that could not be encoded
		403	yet. This data will be lost. Calling the C<stoptls> method in time might
		404	help.
		405
		406	=item peername => $string
		407
		408	A string used to identify the remote site - usually the DNS hostname
		409	(I<not> IDN!) used to create the connection, rarely the IP address.
		410
		411	Apart from being useful in error messages, this string is also used in TLS
		412	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		413	verification will be skipped when C<peername> is not specified or is
		414	C<undef>.
		415
145	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	416	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146		417
147	When this parameter is given, it enables TLS (SSL) mode, that means it	418	When this parameter is given, it enables TLS (SSL) mode, that means
148	will start making tls handshake and will transparently encrypt/decrypt	419	AnyEvent will start a TLS handshake as soon as the connection has been
149	data.	420	established and will transparently encrypt/decrypt data afterwards.
		421
		422	All TLS protocol errors will be signalled as C<EPROTO>, with an
		423	appropriate error message.
150		424
151	TLS mode requires Net::SSLeay to be installed (it will be loaded	425	TLS mode requires Net::SSLeay to be installed (it will be loaded
152	automatically when you try to create a TLS handle).	426	automatically when you try to create a TLS handle): this module doesn't
		427	have a dependency on that module, so if your module requires it, you have
		428	to add the dependency yourself.
153		429
154	For the TLS server side, use C<accept>, and for the TLS client side of a	430	Unlike TCP, TLS has a server and client side: for the TLS server side, use
155	connection, use C<connect> mode.	431	C<accept>, and for the TLS client side of a connection, use C<connect>
		432	mode.
156		433
157	You can also provide your own TLS connection object, but you have	434	You can also provide your own TLS connection object, but you have
158	to make sure that you call either C<Net::SSLeay::set_connect_state>	435	to make sure that you call either C<Net::SSLeay::set_connect_state>
159	or C<Net::SSLeay::set_accept_state> on it before you pass it to	436	or C<Net::SSLeay::set_accept_state> on it before you pass it to
160	AnyEvent::Handle.	437	AnyEvent::Handle. Also, this module will take ownership of this connection
		438	object.
161		439
		440	At some future point, AnyEvent::Handle might switch to another TLS
		441	implementation, then the option to use your own session object will go
		442	away.
		443
		444	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		445	passing in the wrong integer will lead to certain crash. This most often
		446	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		447	segmentation fault.
		448
162	See the C<starttls> method if you need to start TLs negotiation later.	449	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
163		450
164	=item tls_ctx => $ssl_ctx	451	=item tls_ctx => $anyevent_tls
165		452
166	Use the given Net::SSLeay::CTX object to create the new TLS connection	453	Use the given C<AnyEvent::TLS> object to create the new TLS connection
167	(unless a connection object was specified directly). If this parameter is	454	(unless a connection object was specified directly). If this
168	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	455	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		456	C<AnyEvent::Handle::TLS_CTX>.
		457
		458	Instead of an object, you can also specify a hash reference with C<< key
		459	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		460	new TLS context object.
		461
		462	=item on_starttls => $cb->($handle, $success[, $error_message])
		463
		464	This callback will be invoked when the TLS/SSL handshake has finished. If
		465	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		466	(C<on_stoptls> will not be called in this case).
		467
		468	The session in C<< $handle->{tls} >> can still be examined in this
		469	callback, even when the handshake was not successful.
		470
		471	TLS handshake failures will not cause C<on_error> to be invoked when this
		472	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		473
		474	Without this callback, handshake failures lead to C<on_error> being
		475	called as usual.
		476
		477	Note that you cannot just call C<starttls> again in this callback. If you
		478	need to do that, start an zero-second timer instead whose callback can
		479	then call C<< ->starttls >> again.
		480
		481	=item on_stoptls => $cb->($handle)
		482
		483	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		484	set, then it will be invoked after freeing the TLS session. If it is not,
		485	then a TLS shutdown condition will be treated like a normal EOF condition
		486	on the handle.
		487
		488	The session in C<< $handle->{tls} >> can still be examined in this
		489	callback.
		490
		491	This callback will only be called on TLS shutdowns, not when the
		492	underlying handle signals EOF.
		493
		494	=item json => JSON or JSON::XS object
		495
		496	This is the json coder object used by the C<json> read and write types.
		497
		498	If you don't supply it, then AnyEvent::Handle will create and use a
		499	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		500	texts.
		501
		502	Note that you are responsible to depend on the JSON module if you want to
		503	use this functionality, as AnyEvent does not have a dependency itself.
169		504
170	=back	505	=back
171		506
172	=cut	507	=cut
173		508
174	sub new {	509	sub new {
175	my $class = shift;	510	my $class = shift;
176
177	my $self = bless { @_ }, $class;	511	my $self = bless { @_ }, $class;
178		512
179	$self->{fh} or Carp::croak "mandatory argument fh is missing";	513	if ($self->{fh}) {
		514	$self->_start;
		515	return unless $self->{fh}; # could be gone by now
		516
		517	} elsif ($self->{connect}) {
		518	require AnyEvent::Socket;
		519
		520	$self->{peername} = $self->{connect}[0]
		521	unless exists $self->{peername};
		522
		523	$self->{_skip_drain_rbuf} = 1;
		524
		525	{
		526	Scalar::Util::weaken (my $self = $self);
		527
		528	$self->{_connect} =
		529	AnyEvent::Socket::tcp_connect (
		530	$self->{connect}[0],
		531	$self->{connect}[1],
		532	sub {
		533	my ($fh, $host, $port, $retry) = @_;
		534
		535	delete $self->{_connect}; # no longer needed
		536
		537	if ($fh) {
		538	$self->{fh} = $fh;
		539
		540	delete $self->{_skip_drain_rbuf};
		541	$self->_start;
		542
		543	$self->{on_connect}
		544	and $self->{on_connect}($self, $host, $port, sub {
		545	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		546	$self->{_skip_drain_rbuf} = 1;
		547	&$retry;
		548	});
		549
		550	} else {
		551	if ($self->{on_connect_error}) {
		552	$self->{on_connect_error}($self, "$!");
		553	$self->destroy if $self;
		554	} else {
		555	$self->_error ($!, 1);
		556	}
		557	}
		558	},
		559	sub {
		560	local $self->{fh} = $_[0];
		561
		562	$self->{on_prepare}
		563	? $self->{on_prepare}->($self)
		564	: ()
		565	}
		566	);
		567	}
		568
		569	} else {
		570	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		571	}
		572
		573	$self
		574	}
		575
		576	sub _start {
		577	my ($self) = @_;
		578
		579	# too many clueless people try to use udp and similar sockets
		580	# with AnyEvent::Handle, do them a favour.
		581	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		582	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		583	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
180		584
181	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	585	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182		586
183	if ($self->{tls}) {	587	$self->{_activity} =
184	require Net::SSLeay;	588	$self->{_ractivity} =
		589	$self->{_wactivity} = AE::now;
		590
		591	$self->{read_size} ||= 2048;
		592	$self->{max_read_size} = $self->{read_size}
		593	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		594
		595	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		596	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		597	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		598
		599	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		600	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		601
		602	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		603
185	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	604	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186	}	605	if $self->{tls};
187		606
188	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
189	$self->on_error (delete $self->{on_error}) if $self->{on_error};
190	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	607	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
191	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
192		608
193	$self->start_read;	609	$self->start_read
		610	if $self->{on_read} || @{ $self->{_queue} };
194		611
195	$self	612	$self->_drain_wbuf;
196	}	613	}
197		614
198	sub _shutdown {
199	my ($self) = @_;
200
201	delete $self->{rw};
202	delete $self->{ww};
203	delete $self->{fh};
204	}
205
206	sub error {	615	sub _error {
207	my ($self) = @_;	616	my ($self, $errno, $fatal, $message) = @_;
208		617
209	{	618	$! = $errno;
210	local $!;	619	$message ||= "$!";
211	$self->_shutdown;
212	}
213		620
214	if ($self->{on_error}) {	621	if ($self->{on_error}) {
215	$self->{on_error}($self);	622	$self->{on_error}($self, $fatal, $message);
216	} else {	623	$self->destroy if $fatal;
		624	} elsif ($self->{fh} || $self->{connect}) {
		625	$self->destroy;
217	Carp::croak "AnyEvent::Handle uncaught fatal error: $!";	626	Carp::croak "AnyEvent::Handle uncaught error: $message";
218	}	627	}
219	}	628	}
220		629
221	=item $fh = $handle->fh	630	=item $fh = $handle->fh
222		631
223	This method returns the file handle of the L<AnyEvent::Handle> object.	632	This method returns the file handle used to create the L<AnyEvent::Handle> object.
224		633
225	=cut	634	=cut
226		635
227	sub fh { $_[0]->{fh} }	636	sub fh { $_[0]{fh} }
228		637
229	=item $handle->on_error ($cb)	638	=item $handle->on_error ($cb)
230		639
231	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	640	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232		641
…		…
244		653
245	sub on_eof {	654	sub on_eof {
246	$_[0]{on_eof} = $_[1];	655	$_[0]{on_eof} = $_[1];
247	}	656	}
248		657
		658	=item $handle->on_timeout ($cb)
		659
		660	=item $handle->on_rtimeout ($cb)
		661
		662	=item $handle->on_wtimeout ($cb)
		663
		664	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		665	callback, or disables the callback (but not the timeout) if C<$cb> =
		666	C<undef>. See the C<timeout> constructor argument and method.
		667
		668	=cut
		669
		670	# see below
		671
		672	=item $handle->autocork ($boolean)
		673
		674	Enables or disables the current autocork behaviour (see C<autocork>
		675	constructor argument). Changes will only take effect on the next write.
		676
		677	=cut
		678
		679	sub autocork {
		680	$_[0]{autocork} = $_[1];
		681	}
		682
		683	=item $handle->no_delay ($boolean)
		684
		685	Enables or disables the C<no_delay> setting (see constructor argument of
		686	the same name for details).
		687
		688	=cut
		689
		690	sub no_delay {
		691	$_[0]{no_delay} = $_[1];
		692
		693	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		694	if $_[0]{fh};
		695	}
		696
		697	=item $handle->keepalive ($boolean)
		698
		699	Enables or disables the C<keepalive> setting (see constructor argument of
		700	the same name for details).
		701
		702	=cut
		703
		704	sub keepalive {
		705	$_[0]{keepalive} = $_[1];
		706
		707	eval {
		708	local $SIG{__DIE__};
		709	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		710	if $_[0]{fh};
		711	};
		712	}
		713
		714	=item $handle->oobinline ($boolean)
		715
		716	Enables or disables the C<oobinline> setting (see constructor argument of
		717	the same name for details).
		718
		719	=cut
		720
		721	sub oobinline {
		722	$_[0]{oobinline} = $_[1];
		723
		724	eval {
		725	local $SIG{__DIE__};
		726	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		727	if $_[0]{fh};
		728	};
		729	}
		730
		731	=item $handle->keepalive ($boolean)
		732
		733	Enables or disables the C<keepalive> setting (see constructor argument of
		734	the same name for details).
		735
		736	=cut
		737
		738	sub keepalive {
		739	$_[0]{keepalive} = $_[1];
		740
		741	eval {
		742	local $SIG{__DIE__};
		743	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		744	if $_[0]{fh};
		745	};
		746	}
		747
		748	=item $handle->on_starttls ($cb)
		749
		750	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		751
		752	=cut
		753
		754	sub on_starttls {
		755	$_[0]{on_starttls} = $_[1];
		756	}
		757
		758	=item $handle->on_stoptls ($cb)
		759
		760	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		761
		762	=cut
		763
		764	sub on_stoptls {
		765	$_[0]{on_stoptls} = $_[1];
		766	}
		767
		768	=item $handle->rbuf_max ($max_octets)
		769
		770	Configures the C<rbuf_max> setting (C<undef> disables it).
		771
		772	=item $handle->wbuf_max ($max_octets)
		773
		774	Configures the C<wbuf_max> setting (C<undef> disables it).
		775
		776	=cut
		777
		778	sub rbuf_max {
		779	$_[0]{rbuf_max} = $_[1];
		780	}
		781
		782	sub wbuf_max {
		783	$_[0]{wbuf_max} = $_[1];
		784	}
		785
		786	#############################################################################
		787
		788	=item $handle->timeout ($seconds)
		789
		790	=item $handle->rtimeout ($seconds)
		791
		792	=item $handle->wtimeout ($seconds)
		793
		794	Configures (or disables) the inactivity timeout.
		795
		796	The timeout will be checked instantly, so this method might destroy the
		797	handle before it returns.
		798
		799	=item $handle->timeout_reset
		800
		801	=item $handle->rtimeout_reset
		802
		803	=item $handle->wtimeout_reset
		804
		805	Reset the activity timeout, as if data was received or sent.
		806
		807	These methods are cheap to call.
		808
		809	=cut
		810
		811	for my $dir ("", "r", "w") {
		812	my $timeout = "${dir}timeout";
		813	my $tw = "_${dir}tw";
		814	my $on_timeout = "on_${dir}timeout";
		815	my $activity = "_${dir}activity";
		816	my $cb;
		817
		818	*$on_timeout = sub {
		819	$_[0]{$on_timeout} = $_[1];
		820	};
		821
		822	*$timeout = sub {
		823	my ($self, $new_value) = @_;
		824
		825	$new_value >= 0
		826	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		827
		828	$self->{$timeout} = $new_value;
		829	delete $self->{$tw}; &$cb;
		830	};
		831
		832	*{"${dir}timeout_reset"} = sub {
		833	$_[0]{$activity} = AE::now;
		834	};
		835
		836	# main workhorse:
		837	# reset the timeout watcher, as neccessary
		838	# also check for time-outs
		839	$cb = sub {
		840	my ($self) = @_;
		841
		842	if ($self->{$timeout} && $self->{fh}) {
		843	my $NOW = AE::now;
		844
		845	# when would the timeout trigger?
		846	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		847
		848	# now or in the past already?
		849	if ($after <= 0) {
		850	$self->{$activity} = $NOW;
		851
		852	if ($self->{$on_timeout}) {
		853	$self->{$on_timeout}($self);
		854	} else {
		855	$self->_error (Errno::ETIMEDOUT);
		856	}
		857
		858	# callback could have changed timeout value, optimise
		859	return unless $self->{$timeout};
		860
		861	# calculate new after
		862	$after = $self->{$timeout};
		863	}
		864
		865	Scalar::Util::weaken $self;
		866	return unless $self; # ->error could have destroyed $self
		867
		868	$self->{$tw} ||= AE::timer $after, 0, sub {
		869	delete $self->{$tw};
		870	$cb->($self);
		871	};
		872	} else {
		873	delete $self->{$tw};
		874	}
		875	}
		876	}
		877
249	#############################################################################	878	#############################################################################
250		879
251	=back	880	=back
252		881
253	=head2 WRITE QUEUE	882	=head2 WRITE QUEUE
…		…
257		886
258	The write queue is very simple: you can add data to its end, and	887	The write queue is very simple: you can add data to its end, and
259	AnyEvent::Handle will automatically try to get rid of it for you.	888	AnyEvent::Handle will automatically try to get rid of it for you.
260		889
261	When data could be written and the write buffer is shorter then the low	890	When data could be written and the write buffer is shorter then the low
262	water mark, the C<on_drain> callback will be invoked.	891	water mark, the C<on_drain> callback will be invoked once.
263		892
264	=over 4	893	=over 4
265		894
266	=item $handle->on_drain ($cb)	895	=item $handle->on_drain ($cb)
267		896
268	Sets the C<on_drain> callback or clears it (see the description of	897	Sets the C<on_drain> callback or clears it (see the description of
269	C<on_drain> in the constructor).	898	C<on_drain> in the constructor).
270		899
		900	This method may invoke callbacks (and therefore the handle might be
		901	destroyed after it returns).
		902
271	=cut	903	=cut
272		904
273	sub on_drain {	905	sub on_drain {
274	my ($self, $cb) = @_;	906	my ($self, $cb) = @_;
275		907
276	$self->{on_drain} = $cb;	908	$self->{on_drain} = $cb;
277		909
278	$cb->($self)	910	$cb->($self)
279	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	911	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280	}	912	}
281		913
282	=item $handle->push_write ($data)	914	=item $handle->push_write ($data)
283		915
284	Queues the given scalar to be written. You can push as much data as you	916	Queues the given scalar to be written. You can push as much data as
285	want (only limited by the available memory), as C<AnyEvent::Handle>	917	you want (only limited by the available memory and C<wbuf_max>), as
286	buffers it independently of the kernel.	918	C<AnyEvent::Handle> buffers it independently of the kernel.
		919
		920	This method may invoke callbacks (and therefore the handle might be
		921	destroyed after it returns).
287		922
288	=cut	923	=cut
289		924
290	sub _drain_wbuf {	925	sub _drain_wbuf {
291	my ($self) = @_;	926	my ($self) = @_;
292		927
293	if (!$self->{ww} && length $self->{wbuf}) {	928	if (!$self->{_ww} && length $self->{wbuf}) {
		929
294	Scalar::Util::weaken $self;	930	Scalar::Util::weaken $self;
		931
295	my $cb = sub {	932	my $cb = sub {
296	my $len = syswrite $self->{fh}, $self->{wbuf};	933	my $len = syswrite $self->{fh}, $self->{wbuf};
297		934
298	if ($len >= 0) {	935	if (defined $len) {
299	substr $self->{wbuf}, 0, $len, "";	936	substr $self->{wbuf}, 0, $len, "";
300		937
		938	$self->{_activity} = $self->{_wactivity} = AE::now;
		939
301	$self->{on_drain}($self)	940	$self->{on_drain}($self)
302	if $self->{low_water_mark} >= length $self->{wbuf}	941	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303	&& $self->{on_drain};	942	&& $self->{on_drain};
304		943
305	delete $self->{ww} unless length $self->{wbuf};	944	delete $self->{_ww} unless length $self->{wbuf};
306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEAGAIN) {	945	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307	$self->error;	946	$self->_error ($!, 1);
308	}	947	}
309	};	948	};
310		949
311	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	950	# try to write data immediately
		951	$cb->() unless $self->{autocork};
312		952
313	$cb->($self);	953	# if still data left in wbuf, we need to poll
		954	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		955	if length $self->{wbuf};
		956
		957	if (
		958	defined $self->{wbuf_max}
		959	&& $self->{wbuf_max} < length $self->{wbuf}
		960	) {
		961	$self->_error (Errno::ENOSPC, 1), return;
		962	}
314	};	963	};
315	}	964	}
316		965
317	our %WH;	966	our %WH;
318		967
		968	# deprecated
319	sub register_write_type($$) {	969	sub register_write_type($$) {
320	$WH{$_[0]} = $_[1];	970	$WH{$_[0]} = $_[1];
321	}	971	}
322		972
323	sub push_write {	973	sub push_write {
324	my $self = shift;	974	my $self = shift;
325		975
326	if (@_ > 1) {	976	if (@_ > 1) {
327	my $type = shift;	977	my $type = shift;
328		978
		979	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
329	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	980	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
330	->($self, @_);	981	->($self, @_);
331	}	982	}
332		983
		984	# we downgrade here to avoid hard-to-track-down bugs,
		985	# and diagnose the problem earlier and better.
		986
333	if ($self->{filter_w}) {	987	if ($self->{tls}) {
334	$self->{filter_w}->($self, \$_[0]);	988	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		989	&_dotls ($self) if $self->{fh};
335	} else {	990	} else {
336	$self->{wbuf} .= $_[0];	991	utf8::downgrade $self->{wbuf} .= $_[0];
337	$self->_drain_wbuf;	992	$self->_drain_wbuf if $self->{fh};
338	}	993	}
339	}	994	}
340		995
341	=item $handle->push_write (type => @args)	996	=item $handle->push_write (type => @args)
342		997
343	=item $handle->unshift_write (type => @args)
344
345	Instead of formatting your data yourself, you can also let this module do	998	Instead of formatting your data yourself, you can also let this module
346	the job by specifying a type and type-specific arguments.	999	do the job by specifying a type and type-specific arguments. You
		1000	can also specify the (fully qualified) name of a package, in which
		1001	case AnyEvent tries to load the package and then expects to find the
		1002	C<anyevent_write_type> function inside (see "custom write types", below).
347		1003
348	Predefined types are (if you have ideas for additional types, feel free to	1004	Predefined types are (if you have ideas for additional types, feel free to
349	drop by and tell us):	1005	drop by and tell us):
350		1006
351	=over 4	1007	=over 4
…		…
353	=item netstring => $string	1009	=item netstring => $string
354		1010
355	Formats the given value as netstring	1011	Formats the given value as netstring
356	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).	1012	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357		1013
358	=back
359
360	=cut	1014	=cut
361		1015
362	register_write_type netstring => sub {	1016	register_write_type netstring => sub {
363	my ($self, $string) = @_;	1017	my ($self, $string) = @_;
364		1018
365	sprintf "%d:%s,", (length $string), $string	1019	(length $string) . ":$string,"
366	};	1020	};
367		1021
368	=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args)	1022	=item packstring => $format, $data
369		1023
370	This function (not method) lets you add your own types to C<push_write>.	1024	An octet string prefixed with an encoded length. The encoding C<$format>
		1025	uses the same format as a Perl C<pack> format, but must specify a single
		1026	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1027	optional C<!>, C<< < >> or C<< > >> modifier).
		1028
		1029	=cut
		1030
		1031	register_write_type packstring => sub {
		1032	my ($self, $format, $string) = @_;
		1033
		1034	pack "$format/a*", $string
		1035	};
		1036
		1037	=item json => $array_or_hashref
		1038
		1039	Encodes the given hash or array reference into a JSON object. Unless you
		1040	provide your own JSON object, this means it will be encoded to JSON text
		1041	in UTF-8.
		1042
		1043	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		1044	one end of a handle and read them at the other end without using any
		1045	additional framing.
		1046
		1047	The generated JSON text is guaranteed not to contain any newlines: While
		1048	this module doesn't need delimiters after or between JSON texts to be
		1049	able to read them, many other languages depend on that.
		1050
		1051	A simple RPC protocol that interoperates easily with others is to send
		1052	JSON arrays (or objects, although arrays are usually the better choice as
		1053	they mimic how function argument passing works) and a newline after each
		1054	JSON text:
		1055
		1056	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		1057	$handle->push_write ("\012");
		1058
		1059	An AnyEvent::Handle receiver would simply use the C<json> read type and
		1060	rely on the fact that the newline will be skipped as leading whitespace:
		1061
		1062	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1063
		1064	Other languages could read single lines terminated by a newline and pass
		1065	this line into their JSON decoder of choice.
		1066
		1067	=cut
		1068
		1069	sub json_coder() {
		1070	eval { require JSON::XS; JSON::XS->new->utf8 }
		1071	|| do { require JSON; JSON->new->utf8 }
		1072	}
		1073
		1074	register_write_type json => sub {
		1075	my ($self, $ref) = @_;
		1076
		1077	my $json = $self->{json} ||= json_coder;
		1078
		1079	$json->encode ($ref)
		1080	};
		1081
		1082	=item storable => $reference
		1083
		1084	Freezes the given reference using L<Storable> and writes it to the
		1085	handle. Uses the C<nfreeze> format.
		1086
		1087	=cut
		1088
		1089	register_write_type storable => sub {
		1090	my ($self, $ref) = @_;
		1091
		1092	require Storable unless $Storable::VERSION;
		1093
		1094	pack "w/a*", Storable::nfreeze ($ref)
		1095	};
		1096
		1097	=back
		1098
		1099	=item $handle->push_shutdown
		1100
		1101	Sometimes you know you want to close the socket after writing your data
		1102	before it was actually written. One way to do that is to replace your
		1103	C<on_drain> handler by a callback that shuts down the socket (and set
		1104	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1105	replaces the C<on_drain> callback with:
		1106
		1107	sub { shutdown $_[0]{fh}, 1 }
		1108
		1109	This simply shuts down the write side and signals an EOF condition to the
		1110	the peer.
		1111
		1112	You can rely on the normal read queue and C<on_eof> handling
		1113	afterwards. This is the cleanest way to close a connection.
		1114
		1115	This method may invoke callbacks (and therefore the handle might be
		1116	destroyed after it returns).
		1117
		1118	=cut
		1119
		1120	sub push_shutdown {
		1121	my ($self) = @_;
		1122
		1123	delete $self->{low_water_mark};
		1124	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1125	}
		1126
		1127	=item custom write types - Package::anyevent_write_type $handle, @args
		1128
		1129	Instead of one of the predefined types, you can also specify the name of
		1130	a package. AnyEvent will try to load the package and then expects to find
		1131	a function named C<anyevent_write_type> inside. If it isn't found, it
		1132	progressively tries to load the parent package until it either finds the
		1133	function (good) or runs out of packages (bad).
		1134
371	Whenever the given C<type> is used, C<push_write> will invoke the code	1135	Whenever the given C<type> is used, C<push_write> will the function with
372	reference with the handle object and the remaining arguments.	1136	the handle object and the remaining arguments.
373		1137
374	The code reference is supposed to return a single octet string that will	1138	The function is supposed to return a single octet string that will be
375	be appended to the write buffer.	1139	appended to the write buffer, so you can mentally treat this function as a
		1140	"arguments to on-the-wire-format" converter.
376		1141
377	Note that this is a function, and all types registered this way will be	1142	Example: implement a custom write type C<join> that joins the remaining
378	global, so try to use unique names.	1143	arguments using the first one.
		1144
		1145	$handle->push_write (My::Type => " ", 1,2,3);
		1146
		1147	# uses the following package, which can be defined in the "My::Type" or in
		1148	# the "My" modules to be auto-loaded, or just about anywhere when the
		1149	# My::Type::anyevent_write_type is defined before invoking it.
		1150
		1151	package My::Type;
		1152
		1153	sub anyevent_write_type {
		1154	my ($handle, $delim, @args) = @_;
		1155
		1156	join $delim, @args
		1157	}
379		1158
380	=cut	1159	=cut
381		1160
382	#############################################################################	1161	#############################################################################
383		1162
…		…
392	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1171	ways, the "simple" way, using only C<on_read> and the "complex" way, using
393	a queue.	1172	a queue.
394		1173
395	In the simple case, you just install an C<on_read> callback and whenever	1174	In the simple case, you just install an C<on_read> callback and whenever
396	new data arrives, it will be called. You can then remove some data (if	1175	new data arrives, it will be called. You can then remove some data (if
397	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	1176	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
398	or not.	1177	leave the data there if you want to accumulate more (e.g. when only a
		1178	partial message has been received so far), or change the read queue with
		1179	e.g. C<push_read>.
399		1180
400	In the more complex case, you want to queue multiple callbacks. In this	1181	In the more complex case, you want to queue multiple callbacks. In this
401	case, AnyEvent::Handle will call the first queued callback each time new	1182	case, AnyEvent::Handle will call the first queued callback each time new
402	data arrives and removes it when it has done its job (see C<push_read>,	1183	data arrives (also the first time it is queued) and remove it when it has
403	below).	1184	done its job (see C<push_read>, below).
404		1185
405	This way you can, for example, push three line-reads, followed by reading	1186	This way you can, for example, push three line-reads, followed by reading
406	a chunk of data, and AnyEvent::Handle will execute them in order.	1187	a chunk of data, and AnyEvent::Handle will execute them in order.
407		1188
408	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1189	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409	the specified number of bytes which give an XML datagram.	1190	the specified number of bytes which give an XML datagram.
410		1191
411	# in the default state, expect some header bytes	1192	# in the default state, expect some header bytes
412	$handle->on_read (sub {	1193	$handle->on_read (sub {
413	# some data is here, now queue the length-header-read (4 octets)	1194	# some data is here, now queue the length-header-read (4 octets)
414	shift->unshift_read_chunk (4, sub {	1195	shift->unshift_read (chunk => 4, sub {
415	# header arrived, decode	1196	# header arrived, decode
416	my $len = unpack "N", $_[1];	1197	my $len = unpack "N", $_[1];
417		1198
418	# now read the payload	1199	# now read the payload
419	shift->unshift_read_chunk ($len, sub {	1200	shift->unshift_read (chunk => $len, sub {
420	my $xml = $_[1];	1201	my $xml = $_[1];
421	# handle xml	1202	# handle xml
422	});	1203	});
423	});	1204	});
424	});	1205	});
425		1206
426	Example 2: Implement a client for a protocol that replies either with	1207	Example 2: Implement a client for a protocol that replies either with "OK"
427	"OK" and another line or "ERROR" for one request, and 64 bytes for the	1208	and another line or "ERROR" for the first request that is sent, and 64
428	second request. Due tot he availability of a full queue, we can just	1209	bytes for the second request. Due to the availability of a queue, we can
429	pipeline sending both requests and manipulate the queue as necessary in	1210	just pipeline sending both requests and manipulate the queue as necessary
430	the callbacks:	1211	in the callbacks.
431		1212
432	# request one	1213	When the first callback is called and sees an "OK" response, it will
		1214	C<unshift> another line-read. This line-read will be queued I<before> the
		1215	64-byte chunk callback.
		1216
		1217	# request one, returns either "OK + extra line" or "ERROR"
433	$handle->push_write ("request 1\015\012");	1218	$handle->push_write ("request 1\015\012");
434		1219
435	# we expect "ERROR" or "OK" as response, so push a line read	1220	# we expect "ERROR" or "OK" as response, so push a line read
436	$handle->push_read_line (sub {	1221	$handle->push_read (line => sub {
437	# if we got an "OK", we have to _prepend_ another line,	1222	# if we got an "OK", we have to _prepend_ another line,
438	# so it will be read before the second request reads its 64 bytes	1223	# so it will be read before the second request reads its 64 bytes
439	# which are already in the queue when this callback is called	1224	# which are already in the queue when this callback is called
440	# we don't do this in case we got an error	1225	# we don't do this in case we got an error
441	if ($_[1] eq "OK") {	1226	if ($_[1] eq "OK") {
442	$_[0]->unshift_read_line (sub {	1227	$_[0]->unshift_read (line => sub {
443	my $response = $_[1];	1228	my $response = $_[1];
444	...	1229	...
445	});	1230	});
446	}	1231	}
447	});	1232	});
448		1233
449	# request two	1234	# request two, simply returns 64 octets
450	$handle->push_write ("request 2\015\012");	1235	$handle->push_write ("request 2\015\012");
451		1236
452	# simply read 64 bytes, always	1237	# simply read 64 bytes, always
453	$handle->push_read_chunk (64, sub {	1238	$handle->push_read (chunk => 64, sub {
454	my $response = $_[1];	1239	my $response = $_[1];
455	...	1240	...
456	});	1241	});
457		1242
458	=over 4	1243	=over 4
459		1244
460	=cut	1245	=cut
461		1246
462	sub _drain_rbuf {	1247	sub _drain_rbuf {
463	my ($self) = @_;	1248	my ($self) = @_;
		1249
		1250	# avoid recursion
		1251	return if $self->{_skip_drain_rbuf};
		1252	local $self->{_skip_drain_rbuf} = 1;
		1253
		1254	while () {
		1255	# we need to use a separate tls read buffer, as we must not receive data while
		1256	# we are draining the buffer, and this can only happen with TLS.
		1257	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1258	if exists $self->{_tls_rbuf};
		1259
		1260	my $len = length $self->{rbuf};
		1261
		1262	if (my $cb = shift @{ $self->{_queue} }) {
		1263	unless ($cb->($self)) {
		1264	# no progress can be made
		1265	# (not enough data and no data forthcoming)
		1266	$self->_error (Errno::EPIPE, 1), return
		1267	if $self->{_eof};
		1268
		1269	unshift @{ $self->{_queue} }, $cb;
		1270	last;
		1271	}
		1272	} elsif ($self->{on_read}) {
		1273	last unless $len;
		1274
		1275	$self->{on_read}($self);
		1276
		1277	if (
		1278	$len == length $self->{rbuf} # if no data has been consumed
		1279	&& !@{ $self->{_queue} } # and the queue is still empty
		1280	&& $self->{on_read} # but we still have on_read
		1281	) {
		1282	# no further data will arrive
		1283	# so no progress can be made
		1284	$self->_error (Errno::EPIPE, 1), return
		1285	if $self->{_eof};
		1286
		1287	last; # more data might arrive
		1288	}
		1289	} else {
		1290	# read side becomes idle
		1291	delete $self->{_rw} unless $self->{tls};
		1292	last;
		1293	}
		1294	}
		1295
		1296	if ($self->{_eof}) {
		1297	$self->{on_eof}
		1298	? $self->{on_eof}($self)
		1299	: $self->_error (0, 1, "Unexpected end-of-file");
		1300
		1301	return;
		1302	}
464		1303
465	if (	1304	if (
466	defined $self->{rbuf_max}	1305	defined $self->{rbuf_max}
467	&& $self->{rbuf_max} < length $self->{rbuf}	1306	&& $self->{rbuf_max} < length $self->{rbuf}
468	) {	1307	) {
469	$! = &Errno::ENOSPC; return $self->error;	1308	$self->_error (Errno::ENOSPC, 1), return;
470	}	1309	}
471		1310
472	return if $self->{in_drain};	1311	# may need to restart read watcher
473	local $self->{in_drain} = 1;	1312	unless ($self->{_rw}) {
474		1313	$self->start_read
475	while (my $len = length $self->{rbuf}) {	1314	if $self->{on_read} || @{ $self->{_queue} };
476	no strict 'refs';
477	if (my $cb = shift @{ $self->{queue} }) {
478	unless ($cb->($self)) {
479	if ($self->{eof}) {
480	# no progress can be made (not enough data and no data forthcoming)
481	$! = &Errno::EPIPE; return $self->error;
482	}
483
484	unshift @{ $self->{queue} }, $cb;
485	return;
486	}
487	} elsif ($self->{on_read}) {
488	$self->{on_read}($self);
489
490	if (
491	$self->{eof} # if no further data will arrive
492	&& $len == length $self->{rbuf} # and no data has been consumed
493	&& !@{ $self->{queue} } # and the queue is still empty
494	&& $self->{on_read} # and we still want to read data
495	) {
496	# then no progress can be made
497	$! = &Errno::EPIPE; return $self->error;
498	}
499	} else {
500	# read side becomes idle
501	delete $self->{rw};
502	return;
503	}
504	}
505
506	if ($self->{eof}) {
507	$self->_shutdown;
508	$self->{on_eof}($self)
509	if $self->{on_eof};
510	}	1315	}
511	}	1316	}
512		1317
513	=item $handle->on_read ($cb)	1318	=item $handle->on_read ($cb)
514		1319
515	This replaces the currently set C<on_read> callback, or clears it (when	1320	This replaces the currently set C<on_read> callback, or clears it (when
516	the new callback is C<undef>). See the description of C<on_read> in the	1321	the new callback is C<undef>). See the description of C<on_read> in the
517	constructor.	1322	constructor.
518		1323
		1324	This method may invoke callbacks (and therefore the handle might be
		1325	destroyed after it returns).
		1326
519	=cut	1327	=cut
520		1328
521	sub on_read {	1329	sub on_read {
522	my ($self, $cb) = @_;	1330	my ($self, $cb) = @_;
523		1331
524	$self->{on_read} = $cb;	1332	$self->{on_read} = $cb;
		1333	$self->_drain_rbuf if $cb;
525	}	1334	}
526		1335
527	=item $handle->rbuf	1336	=item $handle->rbuf
528		1337
529	Returns the read buffer (as a modifiable lvalue).	1338	Returns the read buffer (as a modifiable lvalue). You can also access the
		1339	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1340	much faster, and no less clean).
530		1341
531	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1342	The only operation allowed on the read buffer (apart from looking at it)
532	you want.	1343	is removing data from its beginning. Otherwise modifying or appending to
		1344	it is not allowed and will lead to hard-to-track-down bugs.
533		1345
534	NOTE: The read buffer should only be used or modified if the C<on_read>,	1346	NOTE: The read buffer should only be used or modified in the C<on_read>
535	C<push_read> or C<unshift_read> methods are used. The other read methods	1347	callback or when C<push_read> or C<unshift_read> are used with a single
536	automatically manage the read buffer.	1348	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1349	will manage the read buffer on their own.
537		1350
538	=cut	1351	=cut
539		1352
540	sub rbuf : lvalue {	1353	sub rbuf : lvalue {
541	$_[0]{rbuf}	1354	$_[0]{rbuf}
…		…
558		1371
559	If enough data was available, then the callback must remove all data it is	1372	If enough data was available, then the callback must remove all data it is
560	interested in (which can be none at all) and return a true value. After returning	1373	interested in (which can be none at all) and return a true value. After returning
561	true, it will be removed from the queue.	1374	true, it will be removed from the queue.
562		1375
		1376	These methods may invoke callbacks (and therefore the handle might be
		1377	destroyed after it returns).
		1378
563	=cut	1379	=cut
564		1380
565	our %RH;	1381	our %RH;
566		1382
567	sub register_read_type($$) {	1383	sub register_read_type($$) {
…		…
573	my $cb = pop;	1389	my $cb = pop;
574		1390
575	if (@_) {	1391	if (@_) {
576	my $type = shift;	1392	my $type = shift;
577		1393
		1394	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
578	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1395	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
579	->($self, $cb, @_);	1396	->($self, $cb, @_);
580	}	1397	}
581		1398
582	push @{ $self->{queue} }, $cb;	1399	push @{ $self->{_queue} }, $cb;
583	$self->_drain_rbuf;	1400	$self->_drain_rbuf;
584	}	1401	}
585		1402
586	sub unshift_read {	1403	sub unshift_read {
587	my $self = shift;	1404	my $self = shift;
588	my $cb = pop;	1405	my $cb = pop;
589		1406
590	if (@_) {	1407	if (@_) {
591	my $type = shift;	1408	my $type = shift;
592		1409
		1410	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
593	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1411	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
594	->($self, $cb, @_);	1412	->($self, $cb, @_);
595	}	1413	}
596		1414
597
598	unshift @{ $self->{queue} }, $cb;	1415	unshift @{ $self->{_queue} }, $cb;
599	$self->_drain_rbuf;	1416	$self->_drain_rbuf;
600	}	1417	}
601		1418
602	=item $handle->push_read (type => @args, $cb)	1419	=item $handle->push_read (type => @args, $cb)
603		1420
604	=item $handle->unshift_read (type => @args, $cb)	1421	=item $handle->unshift_read (type => @args, $cb)
605		1422
606	Instead of providing a callback that parses the data itself you can chose	1423	Instead of providing a callback that parses the data itself you can chose
607	between a number of predefined parsing formats, for chunks of data, lines	1424	between a number of predefined parsing formats, for chunks of data, lines
608	etc.	1425	etc. You can also specify the (fully qualified) name of a package, in
		1426	which case AnyEvent tries to load the package and then expects to find the
		1427	C<anyevent_read_type> function inside (see "custom read types", below).
609		1428
610	Predefined types are (if you have ideas for additional types, feel free to	1429	Predefined types are (if you have ideas for additional types, feel free to
611	drop by and tell us):	1430	drop by and tell us):
612		1431
613	=over 4	1432	=over 4
614		1433
615	=item chunk => $octets, $cb->($self, $data)	1434	=item chunk => $octets, $cb->($handle, $data)
616		1435
617	Invoke the callback only once C<$octets> bytes have been read. Pass the	1436	Invoke the callback only once C<$octets> bytes have been read. Pass the
618	data read to the callback. The callback will never be called with less	1437	data read to the callback. The callback will never be called with less
619	data.	1438	data.
620		1439
621	Example: read 2 bytes.	1440	Example: read 2 bytes.
622		1441
623	$handle->push_read (chunk => 2, sub {	1442	$handle->push_read (chunk => 2, sub {
624	warn "yay ", unpack "H*", $_[1];	1443	say "yay " . unpack "H*", $_[1];
625	});	1444	});
626		1445
627	=cut	1446	=cut
628		1447
629	register_read_type chunk => sub {	1448	register_read_type chunk => sub {
…		…
634	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1453	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635	1	1454	1
636	}	1455	}
637	};	1456	};
638		1457
639	# compatibility with older API
640	sub push_read_chunk {
641	$_[0]->push_read (chunk => $_[1], $_[2]);
642	}
643
644	sub unshift_read_chunk {
645	$_[0]->unshift_read (chunk => $_[1], $_[2]);
646	}
647
648	=item line => [$eol, ]$cb->($self, $line, $eol)	1458	=item line => [$eol, ]$cb->($handle, $line, $eol)
649		1459
650	The callback will be called only once a full line (including the end of	1460	The callback will be called only once a full line (including the end of
651	line marker, C<$eol>) has been read. This line (excluding the end of line	1461	line marker, C<$eol>) has been read. This line (excluding the end of line
652	marker) will be passed to the callback as second argument (C<$line>), and	1462	marker) will be passed to the callback as second argument (C<$line>), and
653	the end of line marker as the third argument (C<$eol>).	1463	the end of line marker as the third argument (C<$eol>).
…		…
667	=cut	1477	=cut
668		1478
669	register_read_type line => sub {	1479	register_read_type line => sub {
670	my ($self, $cb, $eol) = @_;	1480	my ($self, $cb, $eol) = @_;
671		1481
672	$eol = qr|(\015?\012)| if @_ < 3;	1482	if (@_ < 3) {
		1483	# this is more than twice as fast as the generic code below
		1484	sub {
		1485	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1486
		1487	$cb->($_[0], "$1", "$2");
		1488	1
		1489	}
		1490	} else {
673	$eol = quotemeta $eol unless ref $eol;	1491	$eol = quotemeta $eol unless ref $eol;
674	$eol = qr|^(.*?)($eol)|s;	1492	$eol = qr|^(.*?)($eol)|s;
		1493
		1494	sub {
		1495	$_[0]{rbuf} =~ s/$eol// or return;
		1496
		1497	$cb->($_[0], "$1", "$2");
		1498	1
		1499	}
		1500	}
		1501	};
		1502
		1503	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1504
		1505	Makes a regex match against the regex object C<$accept> and returns
		1506	everything up to and including the match.
		1507
		1508	Example: read a single line terminated by '\n'.
		1509
		1510	$handle->push_read (regex => qr<\n>, sub { ... });
		1511
		1512	If C<$reject> is given and not undef, then it determines when the data is
		1513	to be rejected: it is matched against the data when the C<$accept> regex
		1514	does not match and generates an C<EBADMSG> error when it matches. This is
		1515	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1516	receive buffer overflow).
		1517
		1518	Example: expect a single decimal number followed by whitespace, reject
		1519	anything else (not the use of an anchor).
		1520
		1521	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1522
		1523	If C<$skip> is given and not C<undef>, then it will be matched against
		1524	the receive buffer when neither C<$accept> nor C<$reject> match,
		1525	and everything preceding and including the match will be accepted
		1526	unconditionally. This is useful to skip large amounts of data that you
		1527	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1528	have to start matching from the beginning. This is purely an optimisation
		1529	and is usually worth it only when you expect more than a few kilobytes.
		1530
		1531	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1532	expect the header to be very large (it isn't in practice, but...), we use
		1533	a skip regex to skip initial portions. The skip regex is tricky in that
		1534	it only accepts something not ending in either \015 or \012, as these are
		1535	required for the accept regex.
		1536
		1537	$handle->push_read (regex =>
		1538	qr<\015\012\015\012>,
		1539	undef, # no reject
		1540	qr<^.*[^\015\012]>,
		1541	sub { ... });
		1542
		1543	=cut
		1544
		1545	register_read_type regex => sub {
		1546	my ($self, $cb, $accept, $reject, $skip) = @_;
		1547
		1548	my $data;
		1549	my $rbuf = \$self->{rbuf};
675		1550
676	sub {	1551	sub {
677	$_[0]{rbuf} =~ s/$eol// or return;	1552	# accept
678		1553	if ($$rbuf =~ $accept) {
		1554	$data .= substr $$rbuf, 0, $+[0], "";
679	$cb->($_[0], $1, $2);	1555	$cb->($_[0], $data);
		1556	return 1;
		1557	}
680	1	1558
		1559	# reject
		1560	if ($reject && $$rbuf =~ $reject) {
		1561	$_[0]->_error (Errno::EBADMSG);
		1562	}
		1563
		1564	# skip
		1565	if ($skip && $$rbuf =~ $skip) {
		1566	$data .= substr $$rbuf, 0, $+[0], "";
		1567	}
		1568
		1569	()
681	}	1570	}
682	};	1571	};
683		1572
684	# compatibility with older API
685	sub push_read_line {
686	my $self = shift;
687	$self->push_read (line => @_);
688	}
689
690	sub unshift_read_line {
691	my $self = shift;
692	$self->unshift_read (line => @_);
693	}
694
695	=item netstring => $cb->($string)	1573	=item netstring => $cb->($handle, $string)
696		1574
697	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).	1575	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698		1576
699	Throws an error with C<$!> set to EBADMSG on format violations.	1577	Throws an error with C<$!> set to EBADMSG on format violations.
700		1578
…		…
704	my ($self, $cb) = @_;	1582	my ($self, $cb) = @_;
705		1583
706	sub {	1584	sub {
707	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1585	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708	if ($_[0]{rbuf} =~ /[^0-9]/) {	1586	if ($_[0]{rbuf} =~ /[^0-9]/) {
709	$! = &Errno::EBADMSG;	1587	$_[0]->_error (Errno::EBADMSG);
710	$self->error;
711	}	1588	}
712	return;	1589	return;
713	}	1590	}
714		1591
715	my $len = $1;	1592	my $len = $1;
716		1593
717	$self->unshift_read (chunk => $len, sub {	1594	$_[0]->unshift_read (chunk => $len, sub {
718	my $string = $_[1];	1595	my $string = $_[1];
719	$_[0]->unshift_read (chunk => 1, sub {	1596	$_[0]->unshift_read (chunk => 1, sub {
720	if ($_[1] eq ",") {	1597	if ($_[1] eq ",") {
721	$cb->($_[0], $string);	1598	$cb->($_[0], $string);
722	} else {	1599	} else {
723	$! = &Errno::EBADMSG;	1600	$_[0]->_error (Errno::EBADMSG);
724	$self->error;
725	}	1601	}
726	});	1602	});
727	});	1603	});
728		1604
729	1	1605	1
730	}	1606	}
731	};	1607	};
732		1608
		1609	=item packstring => $format, $cb->($handle, $string)
		1610
		1611	An octet string prefixed with an encoded length. The encoding C<$format>
		1612	uses the same format as a Perl C<pack> format, but must specify a single
		1613	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1614	optional C<!>, C<< < >> or C<< > >> modifier).
		1615
		1616	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1617	EPP uses a prefix of C<N> (4 octtes).
		1618
		1619	Example: read a block of data prefixed by its length in BER-encoded
		1620	format (very efficient).
		1621
		1622	$handle->push_read (packstring => "w", sub {
		1623	my ($handle, $data) = @_;
		1624	});
		1625
		1626	=cut
		1627
		1628	register_read_type packstring => sub {
		1629	my ($self, $cb, $format) = @_;
		1630
		1631	sub {
		1632	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1633	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1634	or return;
		1635
		1636	$format = length pack $format, $len;
		1637
		1638	# bypass unshift if we already have the remaining chunk
		1639	if ($format + $len <= length $_[0]{rbuf}) {
		1640	my $data = substr $_[0]{rbuf}, $format, $len;
		1641	substr $_[0]{rbuf}, 0, $format + $len, "";
		1642	$cb->($_[0], $data);
		1643	} else {
		1644	# remove prefix
		1645	substr $_[0]{rbuf}, 0, $format, "";
		1646
		1647	# read remaining chunk
		1648	$_[0]->unshift_read (chunk => $len, $cb);
		1649	}
		1650
		1651	1
		1652	}
		1653	};
		1654
		1655	=item json => $cb->($handle, $hash_or_arrayref)
		1656
		1657	Reads a JSON object or array, decodes it and passes it to the
		1658	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1659
		1660	If a C<json> object was passed to the constructor, then that will be used
		1661	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1662
		1663	This read type uses the incremental parser available with JSON version
		1664	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1665	dependency on your own: this module will load the JSON module, but
		1666	AnyEvent does not depend on it itself.
		1667
		1668	Since JSON texts are fully self-delimiting, the C<json> read and write
		1669	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1670	the C<json> write type description, above, for an actual example.
		1671
		1672	=cut
		1673
		1674	register_read_type json => sub {
		1675	my ($self, $cb) = @_;
		1676
		1677	my $json = $self->{json} ||= json_coder;
		1678
		1679	my $data;
		1680	my $rbuf = \$self->{rbuf};
		1681
		1682	sub {
		1683	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
		1684
		1685	if ($ref) {
		1686	$_[0]{rbuf} = $json->incr_text;
		1687	$json->incr_text = "";
		1688	$cb->($_[0], $ref);
		1689
		1690	1
		1691	} elsif ($@) {
		1692	# error case
		1693	$json->incr_skip;
		1694
		1695	$_[0]{rbuf} = $json->incr_text;
		1696	$json->incr_text = "";
		1697
		1698	$_[0]->_error (Errno::EBADMSG);
		1699
		1700	()
		1701	} else {
		1702	$_[0]{rbuf} = "";
		1703
		1704	()
		1705	}
		1706	}
		1707	};
		1708
		1709	=item storable => $cb->($handle, $ref)
		1710
		1711	Deserialises a L<Storable> frozen representation as written by the
		1712	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1713	data).
		1714
		1715	Raises C<EBADMSG> error if the data could not be decoded.
		1716
		1717	=cut
		1718
		1719	register_read_type storable => sub {
		1720	my ($self, $cb) = @_;
		1721
		1722	require Storable unless $Storable::VERSION;
		1723
		1724	sub {
		1725	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1726	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1727	or return;
		1728
		1729	my $format = length pack "w", $len;
		1730
		1731	# bypass unshift if we already have the remaining chunk
		1732	if ($format + $len <= length $_[0]{rbuf}) {
		1733	my $data = substr $_[0]{rbuf}, $format, $len;
		1734	substr $_[0]{rbuf}, 0, $format + $len, "";
		1735
		1736	eval { $cb->($_[0], Storable::thaw ($data)); 1 }
		1737	or return $_[0]->_error (Errno::EBADMSG);
		1738	} else {
		1739	# remove prefix
		1740	substr $_[0]{rbuf}, 0, $format, "";
		1741
		1742	# read remaining chunk
		1743	$_[0]->unshift_read (chunk => $len, sub {
		1744	eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
		1745	or $_[0]->_error (Errno::EBADMSG);
		1746	});
		1747	}
		1748
		1749	1
		1750	}
		1751	};
		1752
733	=back	1753	=back
734		1754
735	=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args)	1755	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
736		1756
737	This function (not method) lets you add your own types to C<push_read>.	1757	Instead of one of the predefined types, you can also specify the name
		1758	of a package. AnyEvent will try to load the package and then expects to
		1759	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1760	progressively tries to load the parent package until it either finds the
		1761	function (good) or runs out of packages (bad).
738		1762
739	Whenever the given C<type> is used, C<push_read> will invoke the code	1763	Whenever this type is used, C<push_read> will invoke the function with the
740	reference with the handle object, the callback and the remaining	1764	handle object, the original callback and the remaining arguments.
741	arguments.
742		1765
743	The code reference is supposed to return a callback (usually a closure)	1766	The function is supposed to return a callback (usually a closure) that
744	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1767	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1768	mentally treat the function as a "configurable read type to read callback"
		1769	converter.
745		1770
746	It should invoke the passed callback when it is done reading (remember to	1771	It should invoke the original callback when it is done reading (remember
747	pass C<$self> as first argument as all other callbacks do that).	1772	to pass C<$handle> as first argument as all other callbacks do that,
		1773	although there is no strict requirement on this).
748		1774
749	Note that this is a function, and all types registered this way will be
750	global, so try to use unique names.
751
752	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1775	For examples, see the source of this module (F<perldoc -m
753	search for C<register_read_type>)).	1776	AnyEvent::Handle>, search for C<register_read_type>)).
754		1777
755	=item $handle->stop_read	1778	=item $handle->stop_read
756		1779
757	=item $handle->start_read	1780	=item $handle->start_read
758		1781
759	In rare cases you actually do not want to read anything from the	1782	In rare cases you actually do not want to read anything from the
760	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1783	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761	any queued callbacks will be executed then. To start reading again, call	1784	any queued callbacks will be executed then. To start reading again, call
762	C<start_read>.	1785	C<start_read>.
763		1786
		1787	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1788	you change the C<on_read> callback or push/unshift a read callback, and it
		1789	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1790	there are any read requests in the queue.
		1791
		1792	In older versions of this module (<= 5.3), these methods had no effect,
		1793	as TLS does not support half-duplex connections. In current versions they
		1794	work as expected, as this behaviour is required to avoid certain resource
		1795	attacks, where the program would be forced to read (and buffer) arbitrary
		1796	amounts of data before being able to send some data. The drawback is that
		1797	some readings of the the SSL/TLS specifications basically require this
		1798	attack to be working, as SSL/TLS implementations might stall sending data
		1799	during a rehandshake.
		1800
		1801	As a guideline, during the initial handshake, you should not stop reading,
		1802	and as a client, it might cause problems, depending on your application.
		1803
764	=cut	1804	=cut
765		1805
766	sub stop_read {	1806	sub stop_read {
767	my ($self) = @_;	1807	my ($self) = @_;
768		1808
769	delete $self->{rw};	1809	delete $self->{_rw};
770	}	1810	}
771		1811
772	sub start_read {	1812	sub start_read {
773	my ($self) = @_;	1813	my ($self) = @_;
774		1814
775	unless ($self->{rw} || $self->{eof}) {	1815	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
776	Scalar::Util::weaken $self;	1816	Scalar::Util::weaken $self;
777		1817
778	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1818	$self->{_rw} = AE::io $self->{fh}, 0, sub {
779	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1819	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1820	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
781		1821
782	if ($len > 0) {	1822	if ($len > 0) {
783	$self->{filter_r}	1823	$self->{_activity} = $self->{_ractivity} = AE::now;
784	? $self->{filter_r}->($self, $rbuf)	1824
		1825	if ($self->{tls}) {
		1826	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1827
		1828	&_dotls ($self);
		1829	} else {
785	: $self->_drain_rbuf;	1830	$self->_drain_rbuf;
		1831	}
		1832
		1833	if ($len == $self->{read_size}) {
		1834	$self->{read_size} *= 2;
		1835	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1836	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		1837	}
786		1838
787	} elsif (defined $len) {	1839	} elsif (defined $len) {
788	delete $self->{rw};	1840	delete $self->{_rw};
789	$self->{eof} = 1;	1841	$self->{_eof} = 1;
790	$self->_drain_rbuf;	1842	$self->_drain_rbuf;
791		1843
792	} elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAEAGAIN) {	1844	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793	return $self->error;	1845	return $self->_error ($!, 1);
794	}	1846	}
795	});	1847	};
796	}	1848	}
797	}	1849	}
798		1850
		1851	our $ERROR_SYSCALL;
		1852	our $ERROR_WANT_READ;
		1853
		1854	sub _tls_error {
		1855	my ($self, $err) = @_;
		1856
		1857	return $self->_error ($!, 1)
		1858	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1859
		1860	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1861
		1862	# reduce error string to look less scary
		1863	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1864
		1865	if ($self->{_on_starttls}) {
		1866	(delete $self->{_on_starttls})->($self, undef, $err);
		1867	&_freetls;
		1868	} else {
		1869	&_freetls;
		1870	$self->_error (Errno::EPROTO, 1, $err);
		1871	}
		1872	}
		1873
		1874	# poll the write BIO and send the data if applicable
		1875	# also decode read data if possible
		1876	# this is basiclaly our TLS state machine
		1877	# more efficient implementations are possible with openssl,
		1878	# but not with the buggy and incomplete Net::SSLeay.
799	sub _dotls {	1879	sub _dotls {
800	my ($self) = @_;	1880	my ($self) = @_;
801		1881
		1882	my $tmp;
		1883
802	if (length $self->{tls_wbuf}) {	1884	if (length $self->{_tls_wbuf}) {
803	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1885	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804	substr $self->{tls_wbuf}, 0, $len, "";	1886	substr $self->{_tls_wbuf}, 0, $tmp, "";
805	}	1887	}
806	}
807		1888
		1889	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1890	return $self->_tls_error ($tmp)
		1891	if $tmp != $ERROR_WANT_READ
		1892	&& ($tmp != $ERROR_SYSCALL || $!);
		1893	}
		1894
808	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1895	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1896	unless (length $tmp) {
		1897	$self->{_on_starttls}
		1898	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1899	&_freetls;
		1900
		1901	if ($self->{on_stoptls}) {
		1902	$self->{on_stoptls}($self);
		1903	return;
		1904	} else {
		1905	# let's treat SSL-eof as we treat normal EOF
		1906	delete $self->{_rw};
		1907	$self->{_eof} = 1;
		1908	}
		1909	}
		1910
		1911	$self->{_tls_rbuf} .= $tmp;
		1912	$self->_drain_rbuf;
		1913	$self->{tls} or return; # tls session might have gone away in callback
		1914	}
		1915
		1916	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1917	return $self->_tls_error ($tmp)
		1918	if $tmp != $ERROR_WANT_READ
		1919	&& ($tmp != $ERROR_SYSCALL || $!);
		1920
		1921	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809	$self->{wbuf} .= $buf;	1922	$self->{wbuf} .= $tmp;
810	$self->_drain_wbuf;	1923	$self->_drain_wbuf;
		1924	$self->{tls} or return; # tls session might have gone away in callback
811	}	1925	}
812		1926
813	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {	1927	$self->{_on_starttls}
814	$self->{rbuf} .= $buf;	1928	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
815	$self->_drain_rbuf;	1929	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
816	}
817
818	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
819
820	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
821	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
822	$self->error;
823	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
824	$! = &Errno::EIO;
825	$self->error;
826	}
827
828	# all others are fine for our purposes
829	}
830	}	1930	}
831		1931
832	=item $handle->starttls ($tls[, $tls_ctx])	1932	=item $handle->starttls ($tls[, $tls_ctx])
833		1933
834	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1934	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
835	object is created, you can also do that at a later time by calling	1935	object is created, you can also do that at a later time by calling
836	C<starttls>.	1936	C<starttls>.
837		1937
		1938	Starting TLS is currently an asynchronous operation - when you push some
		1939	write data and then call C<< ->starttls >> then TLS negotiation will start
		1940	immediately, after which the queued write data is then sent.
		1941
838	The first argument is the same as the C<tls> constructor argument (either	1942	The first argument is the same as the C<tls> constructor argument (either
839	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1943	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840		1944
841	The second argument is the optional C<Net::SSLeay::CTX> object that is	1945	The second argument is the optional C<AnyEvent::TLS> object that is used
842	used when AnyEvent::Handle has to create its own TLS connection object.	1946	when AnyEvent::Handle has to create its own TLS connection object, or
		1947	a hash reference with C<< key => value >> pairs that will be used to
		1948	construct a new context.
843		1949
844	=cut	1950	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1951	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1952	changed to your liking. Note that the handshake might have already started
		1953	when this function returns.
845		1954
846	# TODO: maybe document...	1955	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1956	handshakes on the same stream. It is best to not attempt to use the
		1957	stream after stopping TLS.
		1958
		1959	This method may invoke callbacks (and therefore the handle might be
		1960	destroyed after it returns).
		1961
		1962	=cut
		1963
		1964	our %TLS_CACHE; #TODO not yet documented, should we?
		1965
847	sub starttls {	1966	sub starttls {
848	my ($self, $ssl, $ctx) = @_;	1967	my ($self, $tls, $ctx) = @_;
849		1968
850	$self->stoptls;	1969	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1970	if $self->{tls};
851		1971
852	if ($ssl eq "accept") {	1972	$self->{tls} = $tls;
853	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1973	$self->{tls_ctx} = $ctx if @_ > 2;
854	Net::SSLeay::set_accept_state ($ssl);	1974
855	} elsif ($ssl eq "connect") {	1975	return unless $self->{fh};
856	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1976
857	Net::SSLeay::set_connect_state ($ssl);	1977	require Net::SSLeay;
		1978
		1979	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1980	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1981
		1982	$tls = delete $self->{tls};
		1983	$ctx = $self->{tls_ctx};
		1984
		1985	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1986
		1987	if ("HASH" eq ref $ctx) {
		1988	require AnyEvent::TLS;
		1989
		1990	if ($ctx->{cache}) {
		1991	my $key = $ctx+0;
		1992	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1993	} else {
		1994	$ctx = new AnyEvent::TLS %$ctx;
		1995	}
		1996	}
858	}	1997
859		1998	$self->{tls_ctx} = $ctx || TLS_CTX ();
860	$self->{tls} = $ssl;	1999	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
861		2000
862	# basically, this is deep magic (because SSL_read should have the same issues)	2001	# basically, this is deep magic (because SSL_read should have the same issues)
863	# but the openssl maintainers basically said: "trust us, it just works".	2002	# but the openssl maintainers basically said: "trust us, it just works".
864	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	2003	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
865	# and mismaintained ssleay-module doesn't even offer them).	2004	# and mismaintained ssleay-module doesn't even offer them).
866	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	2005	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		2006	#
		2007	# in short: this is a mess.
		2008	#
		2009	# note that we do not try to keep the length constant between writes as we are required to do.
		2010	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		2011	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		2012	# have identity issues in that area.
867	Net::SSLeay::CTX_set_mode ($self->{tls},	2013	# Net::SSLeay::CTX_set_mode ($ssl,
868	(eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2014	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869	| (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2015	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2016	Net::SSLeay::CTX_set_mode ($tls, 1|2);
870		2017
871	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2018	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2019	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873		2020
		2021	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2022	$self->{rbuf} = "";
		2023
874	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	2024	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
875		2025
876	$self->{filter_w} = sub {	2026	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
877	$_[0]{tls_wbuf} .= ${$_[1]};	2027	if $self->{on_starttls};
878	&_dotls;	2028
879	};	2029	&_dotls; # need to trigger the initial handshake
880	$self->{filter_r} = sub {	2030	$self->start_read; # make sure we actually do read
881	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882	&_dotls;
883	};
884	}	2031	}
885		2032
886	=item $handle->stoptls	2033	=item $handle->stoptls
887		2034
888	Destroys the SSL connection, if any. Partial read or write data will be	2035	Shuts down the SSL connection - this makes a proper EOF handshake by
889	lost.	2036	sending a close notify to the other side, but since OpenSSL doesn't
		2037	support non-blocking shut downs, it is not guaranteed that you can re-use
		2038	the stream afterwards.
		2039
		2040	This method may invoke callbacks (and therefore the handle might be
		2041	destroyed after it returns).
890		2042
891	=cut	2043	=cut
892		2044
893	sub stoptls {	2045	sub stoptls {
894	my ($self) = @_;	2046	my ($self) = @_;
895		2047
896	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	2048	if ($self->{tls} && $self->{fh}) {
897	delete $self->{tls_rbio};	2049	Net::SSLeay::shutdown ($self->{tls});
898	delete $self->{tls_wbio};	2050
899	delete $self->{tls_wbuf};	2051	&_dotls;
900	delete $self->{filter_r};	2052
901	delete $self->{filter_w};	2053	# # we don't give a shit. no, we do, but we can't. no...#d#
		2054	# # we, we... have to use openssl :/#d#
		2055	# &_freetls;#d#
		2056	}
902	}	2057	}
		2058
		2059	sub _freetls {
		2060	my ($self) = @_;
		2061
		2062	return unless $self->{tls};
		2063
		2064	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2065	if $self->{tls} > 0;
		2066
		2067	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		2068	}
		2069
		2070	=item $handle->resettls
		2071
		2072	This rarely-used method simply resets and TLS state on the handle, usually
		2073	causing data loss.
		2074
		2075	One case where it may be useful is when you want to skip over the data in
		2076	the stream but you are not interested in interpreting it, so data loss is
		2077	no concern.
		2078
		2079	=cut
		2080
		2081	*resettls = \&_freetls;
903		2082
904	sub DESTROY {	2083	sub DESTROY {
905	my $self = shift;	2084	my ($self) = @_;
906		2085
907	$self->stoptls;	2086	&_freetls;
		2087
		2088	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		2089
		2090	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2091	my $fh = delete $self->{fh};
		2092	my $wbuf = delete $self->{wbuf};
		2093
		2094	my @linger;
		2095
		2096	push @linger, AE::io $fh, 1, sub {
		2097	my $len = syswrite $fh, $wbuf, length $wbuf;
		2098
		2099	if ($len > 0) {
		2100	substr $wbuf, 0, $len, "";
		2101	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
		2102	@linger = (); # end
		2103	}
		2104	};
		2105	push @linger, AE::timer $linger, 0, sub {
		2106	@linger = ();
		2107	};
		2108	}
908	}	2109	}
		2110
		2111	=item $handle->destroy
		2112
		2113	Shuts down the handle object as much as possible - this call ensures that
		2114	no further callbacks will be invoked and as many resources as possible
		2115	will be freed. Any method you will call on the handle object after
		2116	destroying it in this way will be silently ignored (and it will return the
		2117	empty list).
		2118
		2119	Normally, you can just "forget" any references to an AnyEvent::Handle
		2120	object and it will simply shut down. This works in fatal error and EOF
		2121	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2122	callback, so when you want to destroy the AnyEvent::Handle object from
		2123	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2124	that case.
		2125
		2126	Destroying the handle object in this way has the advantage that callbacks
		2127	will be removed as well, so if those are the only reference holders (as
		2128	is common), then one doesn't need to do anything special to break any
		2129	reference cycles.
		2130
		2131	The handle might still linger in the background and write out remaining
		2132	data, as specified by the C<linger> option, however.
		2133
		2134	=cut
		2135
		2136	sub destroy {
		2137	my ($self) = @_;
		2138
		2139	$self->DESTROY;
		2140	%$self = ();
		2141	bless $self, "AnyEvent::Handle::destroyed";
		2142	}
		2143
		2144	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2145	#nop
		2146	}
		2147
		2148	=item $handle->destroyed
		2149
		2150	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2151	->destroy >>, true otherwise.
		2152
		2153	Can be useful to decide whether the handle is still valid after some
		2154	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2155	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2156	can destroy the handle, so work can be avoided by checking sometimes:
		2157
		2158	$hdl->starttls ("accept");
		2159	return if $hdl->destroyed;
		2160	$hdl->push_write (...
		2161
		2162	Note that the call to C<push_write> will silently be ignored if the handle
		2163	has been destroyed, so often you can just ignore the possibility of the
		2164	handle being destroyed.
		2165
		2166	=cut
		2167
		2168	sub destroyed { 0 }
		2169	sub AnyEvent::Handle::destroyed::destroyed { 1 }
909		2170
910	=item AnyEvent::Handle::TLS_CTX	2171	=item AnyEvent::Handle::TLS_CTX
911		2172
912	This function creates and returns the Net::SSLeay::CTX object used by	2173	This function creates and returns the AnyEvent::TLS object used by default
913	default for TLS mode.	2174	for TLS mode.
914		2175
915	The context is created like this:	2176	The context is created by calling L<AnyEvent::TLS> without any arguments.
916
917	Net::SSLeay::load_error_strings;
918	Net::SSLeay::SSLeay_add_ssl_algorithms;
919	Net::SSLeay::randomize;
920
921	my $CTX = Net::SSLeay::CTX_new;
922
923	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
924		2177
925	=cut	2178	=cut
926		2179
927	our $TLS_CTX;	2180	our $TLS_CTX;
928		2181
929	sub TLS_CTX() {	2182	sub TLS_CTX() {
930	$TLS_CTX || do {	2183	$TLS_CTX ||= do {
931	require Net::SSLeay;	2184	require AnyEvent::TLS;
932		2185
933	Net::SSLeay::load_error_strings ();	2186	new AnyEvent::TLS
934	Net::SSLeay::SSLeay_add_ssl_algorithms ();
935	Net::SSLeay::randomize ();
936
937	$TLS_CTX = Net::SSLeay::CTX_new ();
938
939	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
940
941	$TLS_CTX
942	}	2187	}
943	}	2188	}
944		2189
945	=back	2190	=back
946		2191
		2192
		2193	=head1 NONFREQUENTLY ASKED QUESTIONS
		2194
		2195	=over 4
		2196
		2197	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2198	still get further invocations!
		2199
		2200	That's because AnyEvent::Handle keeps a reference to itself when handling
		2201	read or write callbacks.
		2202
		2203	It is only safe to "forget" the reference inside EOF or error callbacks,
		2204	from within all other callbacks, you need to explicitly call the C<<
		2205	->destroy >> method.
		2206
		2207	=item Why is my C<on_eof> callback never called?
		2208
		2209	Probably because your C<on_error> callback is being called instead: When
		2210	you have outstanding requests in your read queue, then an EOF is
		2211	considered an error as you clearly expected some data.
		2212
		2213	To avoid this, make sure you have an empty read queue whenever your handle
		2214	is supposed to be "idle" (i.e. connection closes are O.K.). You can set
		2215	an C<on_read> handler that simply pushes the first read requests in the
		2216	queue.
		2217
		2218	See also the next question, which explains this in a bit more detail.
		2219
		2220	=item How can I serve requests in a loop?
		2221
		2222	Most protocols consist of some setup phase (authentication for example)
		2223	followed by a request handling phase, where the server waits for requests
		2224	and handles them, in a loop.
		2225
		2226	There are two important variants: The first (traditional, better) variant
		2227	handles requests until the server gets some QUIT command, causing it to
		2228	close the connection first (highly desirable for a busy TCP server). A
		2229	client dropping the connection is an error, which means this variant can
		2230	detect an unexpected detection close.
		2231
		2232	To handle this case, always make sure you have a on-empty read queue, by
		2233	pushing the "read request start" handler on it:
		2234
		2235	# we assume a request starts with a single line
		2236	my @start_request; @start_request = (line => sub {
		2237	my ($hdl, $line) = @_;
		2238
		2239	... handle request
		2240
		2241	# push next request read, possibly from a nested callback
		2242	$hdl->push_read (@start_request);
		2243	});
		2244
		2245	# auth done, now go into request handling loop
		2246	# now push the first @start_request
		2247	$hdl->push_read (@start_request);
		2248
		2249	By always having an outstanding C<push_read>, the handle always expects
		2250	some data and raises the C<EPIPE> error when the connction is dropped
		2251	unexpectedly.
		2252
		2253	The second variant is a protocol where the client can drop the connection
		2254	at any time. For TCP, this means that the server machine may run out of
		2255	sockets easier, and in general, it means you cannot distinguish a protocl
		2256	failure/client crash from a normal connection close. Nevertheless, these
		2257	kinds of protocols are common (and sometimes even the best solution to the
		2258	problem).
		2259
		2260	Having an outstanding read request at all times is possible if you ignore
		2261	C<EPIPE> errors, but this doesn't help with when the client drops the
		2262	connection during a request, which would still be an error.
		2263
		2264	A better solution is to push the initial request read in an C<on_read>
		2265	callback. This avoids an error, as when the server doesn't expect data
		2266	(i.e. is idly waiting for the next request, an EOF will not raise an
		2267	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2268	and simpler:
		2269
		2270	# auth done, now go into request handling loop
		2271	$hdl->on_read (sub {
		2272	my ($hdl) = @_;
		2273
		2274	# called each time we receive data but the read queue is empty
		2275	# simply start read the request
		2276
		2277	$hdl->push_read (line => sub {
		2278	my ($hdl, $line) = @_;
		2279
		2280	... handle request
		2281
		2282	# do nothing special when the request has been handled, just
		2283	# let the request queue go empty.
		2284	});
		2285	});
		2286
		2287	=item I get different callback invocations in TLS mode/Why can't I pause
		2288	reading?
		2289
		2290	Unlike, say, TCP, TLS connections do not consist of two independent
		2291	communication channels, one for each direction. Or put differently, the
		2292	read and write directions are not independent of each other: you cannot
		2293	write data unless you are also prepared to read, and vice versa.
		2294
		2295	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2296	callback invocations when you are not expecting any read data - the reason
		2297	is that AnyEvent::Handle always reads in TLS mode.
		2298
		2299	During the connection, you have to make sure that you always have a
		2300	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2301	connection (or when you no longer want to use it) you can call the
		2302	C<destroy> method.
		2303
		2304	=item How do I read data until the other side closes the connection?
		2305
		2306	If you just want to read your data into a perl scalar, the easiest way
		2307	to achieve this is by setting an C<on_read> callback that does nothing,
		2308	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2309	will be in C<$_[0]{rbuf}>:
		2310
		2311	$handle->on_read (sub { });
		2312	$handle->on_eof (undef);
		2313	$handle->on_error (sub {
		2314	my $data = delete $_[0]{rbuf};
		2315	});
		2316
		2317	Note that this example removes the C<rbuf> member from the handle object,
		2318	which is not normally allowed by the API. It is expressly permitted in
		2319	this case only, as the handle object needs to be destroyed afterwards.
		2320
		2321	The reason to use C<on_error> is that TCP connections, due to latencies
		2322	and packets loss, might get closed quite violently with an error, when in
		2323	fact all data has been received.
		2324
		2325	It is usually better to use acknowledgements when transferring data,
		2326	to make sure the other side hasn't just died and you got the data
		2327	intact. This is also one reason why so many internet protocols have an
		2328	explicit QUIT command.
		2329
		2330	=item I don't want to destroy the handle too early - how do I wait until
		2331	all data has been written?
		2332
		2333	After writing your last bits of data, set the C<on_drain> callback
		2334	and destroy the handle in there - with the default setting of
		2335	C<low_water_mark> this will be called precisely when all data has been
		2336	written to the socket:
		2337
		2338	$handle->push_write (...);
		2339	$handle->on_drain (sub {
		2340	AE::log debug => "All data submitted to the kernel.";
		2341	undef $handle;
		2342	});
		2343
		2344	If you just want to queue some data and then signal EOF to the other side,
		2345	consider using C<< ->push_shutdown >> instead.
		2346
		2347	=item I want to contact a TLS/SSL server, I don't care about security.
		2348
		2349	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2350	connect to it and then create the AnyEvent::Handle with the C<tls>
		2351	parameter:
		2352
		2353	tcp_connect $host, $port, sub {
		2354	my ($fh) = @_;
		2355
		2356	my $handle = new AnyEvent::Handle
		2357	fh => $fh,
		2358	tls => "connect",
		2359	on_error => sub { ... };
		2360
		2361	$handle->push_write (...);
		2362	};
		2363
		2364	=item I want to contact a TLS/SSL server, I do care about security.
		2365
		2366	Then you should additionally enable certificate verification, including
		2367	peername verification, if the protocol you use supports it (see
		2368	L<AnyEvent::TLS>, C<verify_peername>).
		2369
		2370	E.g. for HTTPS:
		2371
		2372	tcp_connect $host, $port, sub {
		2373	my ($fh) = @_;
		2374
		2375	my $handle = new AnyEvent::Handle
		2376	fh => $fh,
		2377	peername => $host,
		2378	tls => "connect",
		2379	tls_ctx => { verify => 1, verify_peername => "https" },
		2380	...
		2381
		2382	Note that you must specify the hostname you connected to (or whatever
		2383	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2384	peername verification will be done.
		2385
		2386	The above will use the system-dependent default set of trusted CA
		2387	certificates. If you want to check against a specific CA, add the
		2388	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2389
		2390	tls_ctx => {
		2391	verify => 1,
		2392	verify_peername => "https",
		2393	ca_file => "my-ca-cert.pem",
		2394	},
		2395
		2396	=item I want to create a TLS/SSL server, how do I do that?
		2397
		2398	Well, you first need to get a server certificate and key. You have
		2399	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2400	self-signed certificate (cheap. check the search engine of your choice,
		2401	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2402	nice program for that purpose).
		2403
		2404	Then create a file with your private key (in PEM format, see
		2405	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2406	file should then look like this:
		2407
		2408	-----BEGIN RSA PRIVATE KEY-----
		2409	...header data
		2410	... lots of base64'y-stuff
		2411	-----END RSA PRIVATE KEY-----
		2412
		2413	-----BEGIN CERTIFICATE-----
		2414	... lots of base64'y-stuff
		2415	-----END CERTIFICATE-----
		2416
		2417	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2418	specify this file as C<cert_file>:
		2419
		2420	tcp_server undef, $port, sub {
		2421	my ($fh) = @_;
		2422
		2423	my $handle = new AnyEvent::Handle
		2424	fh => $fh,
		2425	tls => "accept",
		2426	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2427	...
		2428
		2429	When you have intermediate CA certificates that your clients might not
		2430	know about, just append them to the C<cert_file>.
		2431
		2432	=back
		2433
		2434	=head1 SUBCLASSING AnyEvent::Handle
		2435
		2436	In many cases, you might want to subclass AnyEvent::Handle.
		2437
		2438	To make this easier, a given version of AnyEvent::Handle uses these
		2439	conventions:
		2440
		2441	=over 4
		2442
		2443	=item * all constructor arguments become object members.
		2444
		2445	At least initially, when you pass a C<tls>-argument to the constructor it
		2446	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2447	mutated later on (for example C<tls> will hold the TLS connection object).
		2448
		2449	=item * other object member names are prefixed with an C<_>.
		2450
		2451	All object members not explicitly documented (internal use) are prefixed
		2452	with an underscore character, so the remaining non-C<_>-namespace is free
		2453	for use for subclasses.
		2454
		2455	=item * all members not documented here and not prefixed with an underscore
		2456	are free to use in subclasses.
		2457
		2458	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2459	member variables, but that's just life. At least it is documented.
		2460
		2461	=back
		2462
947	=head1 AUTHOR	2463	=head1 AUTHOR
948		2464
949	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2465	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950		2466
951	=cut	2467	=cut
952		2468
953	1; # End of AnyEvent::Handle	2469	1
		2470

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