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Revision 1.197 by root, Tue Aug 31 00:59:55 2010 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	warn "got error $msg\n";
		17	$hdl->destroy;
		18	$cv->send;
34	);	19	};
35		20
36	# send some request line	21	# send some request line
37	$handle->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
38		23
39	# read the response line	24	# read the response line
40	$handle->push_read (line => sub {	25	$hdl->push_read (line => sub {
41	my ($handle, $line) = @_;	26	my ($hdl, $line) = @_;
42	warn "read line <$line>\n";	27	warn "got line <$line>\n";
43	$cv->send;	28	$cv->send;
44	});	29	});
45		30
46	$cv->recv;	31	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	This module is a helper module to make it easier to do event-based I/O on	35	This module 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 or other stream things).
52	on sockets see L<AnyEvent::Util>.	37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
53		40
54	In the following, when the documentation refers to of "bytes" then this	41	In the following, when the documentation refers to of "bytes" then this
55	means characters. As sysread and syswrite are used for all I/O, their	42	means 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.
57		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		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
61	=head1 METHODS	80	=head1 METHODS
62		81
63	=over 4	82	=over 4
64		83
65	=item B<new (%args)>	84	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66		85
67	The constructor supports these arguments (all as key => value pairs).	86	The constructor supports these arguments (all as C<< key => value >> pairs).
68		87
69	=over 4	88	=over 4
70		89
71	=item fh => $filehandle [MANDATORY]	90	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72		91
73	The filehandle this L<AnyEvent::Handle> object will operate on.	92	The filehandle this L<AnyEvent::Handle> object will operate on.
74
75	NOTE: The filehandle will be set to non-blocking (using	93	NOTE: The filehandle will be set to non-blocking mode (using
76	AnyEvent::Util::fh_nonblocking).	94	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		95	that mode.
77		96
78	=item on_eof => $cb->($self)	97	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
79		98
80	Set the callback to be called on EOF.	99	Try to connect to the specified host and service (port), using
		100	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		101	default C<peername>.
81		102
82	While not mandatory, it is highly recommended to set an eof callback,	103	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		104
		105	It is possible to push requests on the read and write queues, and modify
		106	properties of the stream, even while AnyEvent::Handle is connecting.
		107
		108	When this parameter is specified, then the C<on_prepare>,
		109	C<on_connect_error> and C<on_connect> callbacks will be called under the
		110	appropriate circumstances:
		111
		112	=over 4
		113
86	=item on_error => $cb->($self)	114	=item on_prepare => $cb->($handle)
87		115
		116	This (rarely used) callback is called before a new connection is
		117	attempted, but after the file handle has been created. It could be used to
		118	prepare the file handle with parameters required for the actual connect
		119	(as opposed to settings that can be changed when the connection is already
		120	established).
		121
		122	The return value of this callback should be the connect timeout value in
		123	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		124	timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The actual numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	When, for some reason, the handle is not acceptable, then calling
		134	C<$retry> will continue with the next connection target (in case of
		135	multi-homed hosts or SRV records there can be multiple connection
		136	endpoints). At the time it is called the read and write queues, eof
		137	status, tls status and similar properties of the handle will have been
		138	reset.
		139
		140	In most cases, ignoring the C<$retry> parameter is the way to go.
		141
		142	=item on_connect_error => $cb->($handle, $message)
		143
		144	This callback is called when the connection could not be
		145	established. C<$!> will contain the relevant error code, and C<$message> a
		146	message describing it (usually the same as C<"$!">).
		147
		148	If this callback isn't specified, then C<on_error> will be called with a
		149	fatal error instead.
		150
		151	=back
		152
		153	=item on_error => $cb->($handle, $fatal, $message)
		154
88	This is the fatal error callback, that is called when, well, a fatal error	155	This is the error callback, which is called when, well, some error
89	occurs, such as not being able to resolve the hostname, failure to connect	156	occured, such as not being able to resolve the hostname, failure to
90	or a read error.	157	connect or a read error.
91		158
92	The object will not be in a usable state when this callback has been	159	Some errors are fatal (which is indicated by C<$fatal> being true). On
93	called.	160	fatal errors the handle object will be destroyed (by a call to C<< ->
		161	destroy >>) after invoking the error callback (which means you are free to
		162	examine the handle object). Examples of fatal errors are an EOF condition
		163	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		164	cases where the other side can close the connection at their will it is
		165	often easiest to not report C<EPIPE> errors in this callback.
		166
		167	AnyEvent::Handle tries to find an appropriate error code for you to check
		168	against, but in some cases (TLS errors), this does not work well. It is
		169	recommended to always output the C<$message> argument in human-readable
		170	error messages (it's usually the same as C<"$!">).
		171
		172	Non-fatal errors can be retried by simply returning, but it is recommended
		173	to simply ignore this parameter and instead abondon the handle object
		174	when this callback is invoked. Examples of non-fatal errors are timeouts
		175	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
94		176
95	On callback entrance, the value of C<$!> contains the operating system	177	On callback entrance, the value of C<$!> contains the operating system
96	error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>).	178	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		179	C<EPROTO>).
97		180
98	While not mandatory, it is I<highly> recommended to set this callback, as	181	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	182	you will not be notified of errors otherwise. The default simply calls
100	die.	183	C<croak>.
101		184
102	=item on_read => $cb->($self)	185	=item on_read => $cb->($handle)
103		186
104	This sets the default read callback, which is called when data arrives	187	This sets the default read callback, which is called when data arrives
105	and no read request is in the queue.	188	and no read request is in the queue (unlike read queue callbacks, this
		189	callback will only be called when at least one octet of data is in the
		190	read buffer).
106		191
107	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	192	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108	method or access the C<$self->{rbuf}> member directly.	193	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		194	must not enlarge or modify the read buffer, you can only remove data at
		195	the beginning from it.
		196
		197	You can also call C<< ->push_read (...) >> or any other function that
		198	modifies the read queue. Or do both. Or ...
109		199
110	When an EOF condition is detected then AnyEvent::Handle will first try to	200	When an EOF condition is detected then AnyEvent::Handle will first try to
111	feed all the remaining data to the queued callbacks and C<on_read> before	201	feed all the remaining data to the queued callbacks and C<on_read> before
112	calling the C<on_eof> callback. If no progress can be made, then a fatal	202	calling the C<on_eof> callback. If no progress can be made, then a fatal
113	error will be raised (with C<$!> set to C<EPIPE>).	203	error will be raised (with C<$!> set to C<EPIPE>).
114		204
		205	Note that, unlike requests in the read queue, an C<on_read> callback
		206	doesn't mean you I<require> some data: if there is an EOF and there
		207	are outstanding read requests then an error will be flagged. With an
		208	C<on_read> callback, the C<on_eof> callback will be invoked.
		209
		210	=item on_eof => $cb->($handle)
		211
		212	Set the callback to be called when an end-of-file condition is detected,
		213	i.e. in the case of a socket, when the other side has closed the
		214	connection cleanly, and there are no outstanding read requests in the
		215	queue (if there are read requests, then an EOF counts as an unexpected
		216	connection close and will be flagged as an error).
		217
		218	For sockets, this just means that the other side has stopped sending data,
		219	you can still try to write data, and, in fact, one can return from the EOF
		220	callback and continue writing data, as only the read part has been shut
		221	down.
		222
		223	If an EOF condition has been detected but no C<on_eof> callback has been
		224	set, then a fatal error will be raised with C<$!> set to <0>.
		225
115	=item on_drain => $cb->()	226	=item on_drain => $cb->($handle)
116		227
117	This sets the callback that is called when the write buffer becomes empty	228	This sets the callback that is called when the write buffer becomes empty
118	(or when the callback is set and the buffer is empty already).	229	(or when the callback is set and the buffer is empty already).
119		230
120	To append to the write buffer, use the C<< ->push_write >> method.	231	To append to the write buffer, use the C<< ->push_write >> method.
121		232
		233	This callback is useful when you don't want to put all of your write data
		234	into the queue at once, for example, when you want to write the contents
		235	of some file to the socket you might not want to read the whole file into
		236	memory and push it into the queue, but instead only read more data from
		237	the file when the write queue becomes empty.
		238
		239	=item timeout => $fractional_seconds
		240
		241	=item rtimeout => $fractional_seconds
		242
		243	=item wtimeout => $fractional_seconds
		244
		245	If non-zero, then these enables an "inactivity" timeout: whenever this
		246	many seconds pass without a successful read or write on the underlying
		247	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		248	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		249	error will be raised).
		250
		251	There are three variants of the timeouts that work fully independent
		252	of each other, for both read and write, just read, and just write:
		253	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		254	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		255	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		256
		257	Note that timeout processing is also active when you currently do not have
		258	any outstanding read or write requests: If you plan to keep the connection
		259	idle then you should disable the timout temporarily or ignore the timeout
		260	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		261	restart the timeout.
		262
		263	Zero (the default) disables this timeout.
		264
		265	=item on_timeout => $cb->($handle)
		266
		267	Called whenever the inactivity timeout passes. If you return from this
		268	callback, then the timeout will be reset as if some activity had happened,
		269	so this condition is not fatal in any way.
		270
122	=item rbuf_max => <bytes>	271	=item rbuf_max => <bytes>
123		272
124	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	273	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125	when the read buffer ever (strictly) exceeds this size. This is useful to	274	when the read buffer ever (strictly) exceeds this size. This is useful to
126	avoid denial-of-service attacks.	275	avoid some forms of denial-of-service attacks.
127		276
128	For example, a server accepting connections from untrusted sources should	277	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	278	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	279	(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	280	amount of data without a callback ever being called as long as the line
132	isn't finished).	281	isn't finished).
133		282
		283	=item autocork => <boolean>
		284
		285	When disabled (the default), then C<push_write> will try to immediately
		286	write the data to the handle, if possible. This avoids having to register
		287	a write watcher and wait for the next event loop iteration, but can
		288	be inefficient if you write multiple small chunks (on the wire, this
		289	disadvantage is usually avoided by your kernel's nagle algorithm, see
		290	C<no_delay>, but this option can save costly syscalls).
		291
		292	When enabled, then writes will always be queued till the next event loop
		293	iteration. This is efficient when you do many small writes per iteration,
		294	but less efficient when you do a single write only per iteration (or when
		295	the write buffer often is full). It also increases write latency.
		296
		297	=item no_delay => <boolean>
		298
		299	When doing small writes on sockets, your operating system kernel might
		300	wait a bit for more data before actually sending it out. This is called
		301	the Nagle algorithm, and usually it is beneficial.
		302
		303	In some situations you want as low a delay as possible, which can be
		304	accomplishd by setting this option to a true value.
		305
		306	The default is your opertaing system's default behaviour (most likely
		307	enabled), this option explicitly enables or disables it, if possible.
		308
		309	=item keepalive => <boolean>
		310
		311	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		312	normally, TCP connections have no time-out once established, so TCP
		313	connections, once established, can stay alive forever even when the other
		314	side has long gone. TCP keepalives are a cheap way to take down long-lived
		315	TCP connections whent he other side becomes unreachable. While the default
		316	is OS-dependent, TCP keepalives usually kick in after around two hours,
		317	and, if the other side doesn't reply, take down the TCP connection some 10
		318	to 15 minutes later.
		319
		320	It is harmless to specify this option for file handles that do not support
		321	keepalives, and enabling it on connections that are potentially long-lived
		322	is usually a good idea.
		323
		324	=item oobinline => <boolean>
		325
		326	BSD majorly fucked up the implementation of TCP urgent data. The result
		327	is that almost no OS implements TCP according to the specs, and every OS
		328	implements it slightly differently.
		329
		330	If you want to handle TCP urgent data, then setting this flag (the default
		331	is enabled) gives you the most portable way of getting urgent data, by
		332	putting it into the stream.
		333
		334	Since BSD emulation of OOB data on top of TCP's urgent data can have
		335	security implications, AnyEvent::Handle sets this flag automatically
		336	unless explicitly specified. Note that setting this flag after
		337	establishing a connection I<may> be a bit too late (data loss could
		338	already have occured on BSD systems), but at least it will protect you
		339	from most attacks.
		340
134	=item read_size => <bytes>	341	=item read_size => <bytes>
135		342
136	The default read block size (the amount of bytes this module will try to read	343	The default read block size (the amount of bytes this module will
137	on each [loop iteration). Default: C<4096>.	344	try to read during each loop iteration, which affects memory
		345	requirements). Default: C<8192>.
138		346
139	=item low_water_mark => <bytes>	347	=item low_water_mark => <bytes>
140		348
141	Sets the amount of bytes (default: C<0>) that make up an "empty" write	349	Sets the amount 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	350	buffer: If the write reaches this size or gets even samller it is
143	considered empty.	351	considered empty.
144		352
		353	Sometimes it can be beneficial (for performance reasons) to add data to
		354	the write buffer before it is fully drained, but this is a rare case, as
		355	the operating system kernel usually buffers data as well, so the default
		356	is good in almost all cases.
		357
		358	=item linger => <seconds>
		359
		360	If non-zero (default: C<3600>), then the destructor of the
		361	AnyEvent::Handle object will check whether there is still outstanding
		362	write data and will install a watcher that will write this data to the
		363	socket. No errors will be reported (this mostly matches how the operating
		364	system treats outstanding data at socket close time).
		365
		366	This will not work for partial TLS data that could not be encoded
		367	yet. This data will be lost. Calling the C<stoptls> method in time might
		368	help.
		369
		370	=item peername => $string
		371
		372	A string used to identify the remote site - usually the DNS hostname
		373	(I<not> IDN!) used to create the connection, rarely the IP address.
		374
		375	Apart from being useful in error messages, this string is also used in TLS
		376	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		377	verification will be skipped when C<peername> is not specified or
		378	C<undef>.
		379
145	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	380	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146		381
147	When this parameter is given, it enables TLS (SSL) mode, that means it	382	When this parameter is given, it enables TLS (SSL) mode, that means
148	will start making tls handshake and will transparently encrypt/decrypt	383	AnyEvent will start a TLS handshake as soon as the connection has been
149	data.	384	established and will transparently encrypt/decrypt data afterwards.
		385
		386	All TLS protocol errors will be signalled as C<EPROTO>, with an
		387	appropriate error message.
150		388
151	TLS mode requires Net::SSLeay to be installed (it will be loaded	389	TLS mode requires Net::SSLeay to be installed (it will be loaded
152	automatically when you try to create a TLS handle).	390	automatically when you try to create a TLS handle): this module doesn't
		391	have a dependency on that module, so if your module requires it, you have
		392	to add the dependency yourself.
153		393
154	For the TLS server side, use C<accept>, and for the TLS client side of a	394	Unlike TCP, TLS has a server and client side: for the TLS server side, use
155	connection, use C<connect> mode.	395	C<accept>, and for the TLS client side of a connection, use C<connect>
		396	mode.
156		397
157	You can also provide your own TLS connection object, but you have	398	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>	399	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	400	or C<Net::SSLeay::set_accept_state> on it before you pass it to
160	AnyEvent::Handle.	401	AnyEvent::Handle. Also, this module will take ownership of this connection
		402	object.
161		403
		404	At some future point, AnyEvent::Handle might switch to another TLS
		405	implementation, then the option to use your own session object will go
		406	away.
		407
		408	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		409	passing in the wrong integer will lead to certain crash. This most often
		410	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		411	segmentation fault.
		412
162	See the C<starttls> method if you need to start TLs negotiation later.	413	See the C<< ->starttls >> method for when need to start TLS negotiation later.
163		414
164	=item tls_ctx => $ssl_ctx	415	=item tls_ctx => $anyevent_tls
165		416
166	Use the given Net::SSLeay::CTX object to create the new TLS connection	417	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	418	(unless a connection object was specified directly). If this parameter is
168	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	419	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169		420
		421	Instead of an object, you can also specify a hash reference with C<< key
		422	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		423	new TLS context object.
		424
		425	=item on_starttls => $cb->($handle, $success[, $error_message])
		426
		427	This callback will be invoked when the TLS/SSL handshake has finished. If
		428	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		429	(C<on_stoptls> will not be called in this case).
		430
		431	The session in C<< $handle->{tls} >> can still be examined in this
		432	callback, even when the handshake was not successful.
		433
		434	TLS handshake failures will not cause C<on_error> to be invoked when this
		435	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		436
		437	Without this callback, handshake failures lead to C<on_error> being
		438	called, as normal.
		439
		440	Note that you cannot call C<starttls> right again in this callback. If you
		441	need to do that, start an zero-second timer instead whose callback can
		442	then call C<< ->starttls >> again.
		443
		444	=item on_stoptls => $cb->($handle)
		445
		446	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		447	set, then it will be invoked after freeing the TLS session. If it is not,
		448	then a TLS shutdown condition will be treated like a normal EOF condition
		449	on the handle.
		450
		451	The session in C<< $handle->{tls} >> can still be examined in this
		452	callback.
		453
		454	This callback will only be called on TLS shutdowns, not when the
		455	underlying handle signals EOF.
		456
		457	=item json => JSON or JSON::XS object
		458
		459	This is the json coder object used by the C<json> read and write types.
		460
		461	If you don't supply it, then AnyEvent::Handle will create and use a
		462	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		463	texts.
		464
		465	Note that you are responsible to depend on the JSON module if you want to
		466	use this functionality, as AnyEvent does not have a dependency itself.
		467
170	=back	468	=back
171		469
172	=cut	470	=cut
173		471
174	sub new {	472	sub new {
175	my $class = shift;	473	my $class = shift;
176
177	my $self = bless { @_ }, $class;	474	my $self = bless { @_ }, $class;
178		475
179	$self->{fh} or Carp::croak "mandatory argument fh is missing";	476	if ($self->{fh}) {
		477	$self->_start;
		478	return unless $self->{fh}; # could be gone by now
		479
		480	} elsif ($self->{connect}) {
		481	require AnyEvent::Socket;
		482
		483	$self->{peername} = $self->{connect}[0]
		484	unless exists $self->{peername};
		485
		486	$self->{_skip_drain_rbuf} = 1;
		487
		488	{
		489	Scalar::Util::weaken (my $self = $self);
		490
		491	$self->{_connect} =
		492	AnyEvent::Socket::tcp_connect (
		493	$self->{connect}[0],
		494	$self->{connect}[1],
		495	sub {
		496	my ($fh, $host, $port, $retry) = @_;
		497
		498	if ($fh) {
		499	$self->{fh} = $fh;
		500
		501	delete $self->{_skip_drain_rbuf};
		502	$self->_start;
		503
		504	$self->{on_connect}
		505	and $self->{on_connect}($self, $host, $port, sub {
		506	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		507	$self->{_skip_drain_rbuf} = 1;
		508	&$retry;
		509	});
		510
		511	} else {
		512	if ($self->{on_connect_error}) {
		513	$self->{on_connect_error}($self, "$!");
		514	$self->destroy;
		515	} else {
		516	$self->_error ($!, 1);
		517	}
		518	}
		519	},
		520	sub {
		521	local $self->{fh} = $_[0];
		522
		523	$self->{on_prepare}
		524	? $self->{on_prepare}->($self)
		525	: ()
		526	}
		527	);
		528	}
		529
		530	} else {
		531	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		532	}
		533
		534	$self
		535	}
		536
		537	sub _start {
		538	my ($self) = @_;
		539
		540	# too many clueless people try to use udp and similar sockets
		541	# with AnyEvent::Handle, do them a favour.
		542	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		543	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		544	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
180		545
181	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	546	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182		547
183	if ($self->{tls}) {	548	$self->{_activity} =
184	require Net::SSLeay;	549	$self->{_ractivity} =
		550	$self->{_wactivity} = AE::now;
		551
		552	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		553	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		554	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		555
		556	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		557	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		558
		559	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		560
185	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	561	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186	}	562	if $self->{tls};
187		563
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};	564	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
191	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
192		565
193	$self->start_read;	566	$self->start_read
		567	if $self->{on_read} || @{ $self->{_queue} };
194		568
195	$self	569	$self->_drain_wbuf;
196	}	570	}
197		571
198	sub _shutdown {
199	my ($self) = @_;
200
201	delete $self->{rw};
202	delete $self->{ww};
203	delete $self->{fh};
204	}
205
206	sub error {	572	sub _error {
207	my ($self) = @_;	573	my ($self, $errno, $fatal, $message) = @_;
208		574
209	{	575	$! = $errno;
210	local $!;	576	$message ||= "$!";
211	$self->_shutdown;
212	}
213		577
214	if ($self->{on_error}) {	578	if ($self->{on_error}) {
215	$self->{on_error}($self);	579	$self->{on_error}($self, $fatal, $message);
216	} else {	580	$self->destroy if $fatal;
		581	} elsif ($self->{fh} || $self->{connect}) {
		582	$self->destroy;
217	Carp::croak "AnyEvent::Handle uncaught fatal error: $!";	583	Carp::croak "AnyEvent::Handle uncaught error: $message";
218	}	584	}
219	}	585	}
220		586
221	=item $fh = $handle->fh	587	=item $fh = $handle->fh
222		588
223	This method returns the file handle of the L<AnyEvent::Handle> object.	589	This method returns the file handle used to create the L<AnyEvent::Handle> object.
224		590
225	=cut	591	=cut
226		592
227	sub fh { $_[0]->{fh} }	593	sub fh { $_[0]{fh} }
228		594
229	=item $handle->on_error ($cb)	595	=item $handle->on_error ($cb)
230		596
231	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	597	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232		598
…		…
244		610
245	sub on_eof {	611	sub on_eof {
246	$_[0]{on_eof} = $_[1];	612	$_[0]{on_eof} = $_[1];
247	}	613	}
248		614
		615	=item $handle->on_timeout ($cb)
		616
		617	=item $handle->on_rtimeout ($cb)
		618
		619	=item $handle->on_wtimeout ($cb)
		620
		621	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		622	callback, or disables the callback (but not the timeout) if C<$cb> =
		623	C<undef>. See the C<timeout> constructor argument and method.
		624
		625	=cut
		626
		627	# see below
		628
		629	=item $handle->autocork ($boolean)
		630
		631	Enables or disables the current autocork behaviour (see C<autocork>
		632	constructor argument). Changes will only take effect on the next write.
		633
		634	=cut
		635
		636	sub autocork {
		637	$_[0]{autocork} = $_[1];
		638	}
		639
		640	=item $handle->no_delay ($boolean)
		641
		642	Enables or disables the C<no_delay> setting (see constructor argument of
		643	the same name for details).
		644
		645	=cut
		646
		647	sub no_delay {
		648	$_[0]{no_delay} = $_[1];
		649
		650	eval {
		651	local $SIG{__DIE__};
		652	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		653	if $_[0]{fh};
		654	};
		655	}
		656
		657	=item $handle->keepalive ($boolean)
		658
		659	Enables or disables the C<keepalive> setting (see constructor argument of
		660	the same name for details).
		661
		662	=cut
		663
		664	sub keepalive {
		665	$_[0]{keepalive} = $_[1];
		666
		667	eval {
		668	local $SIG{__DIE__};
		669	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		670	if $_[0]{fh};
		671	};
		672	}
		673
		674	=item $handle->oobinline ($boolean)
		675
		676	Enables or disables the C<oobinline> setting (see constructor argument of
		677	the same name for details).
		678
		679	=cut
		680
		681	sub oobinline {
		682	$_[0]{oobinline} = $_[1];
		683
		684	eval {
		685	local $SIG{__DIE__};
		686	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		687	if $_[0]{fh};
		688	};
		689	}
		690
		691	=item $handle->keepalive ($boolean)
		692
		693	Enables or disables the C<keepalive> setting (see constructor argument of
		694	the same name for details).
		695
		696	=cut
		697
		698	sub keepalive {
		699	$_[0]{keepalive} = $_[1];
		700
		701	eval {
		702	local $SIG{__DIE__};
		703	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		704	if $_[0]{fh};
		705	};
		706	}
		707
		708	=item $handle->on_starttls ($cb)
		709
		710	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		711
		712	=cut
		713
		714	sub on_starttls {
		715	$_[0]{on_starttls} = $_[1];
		716	}
		717
		718	=item $handle->on_stoptls ($cb)
		719
		720	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		721
		722	=cut
		723
		724	sub on_stoptls {
		725	$_[0]{on_stoptls} = $_[1];
		726	}
		727
		728	=item $handle->rbuf_max ($max_octets)
		729
		730	Configures the C<rbuf_max> setting (C<undef> disables it).
		731
		732	=cut
		733
		734	sub rbuf_max {
		735	$_[0]{rbuf_max} = $_[1];
		736	}
		737
		738	#############################################################################
		739
		740	=item $handle->timeout ($seconds)
		741
		742	=item $handle->rtimeout ($seconds)
		743
		744	=item $handle->wtimeout ($seconds)
		745
		746	Configures (or disables) the inactivity timeout.
		747
		748	=item $handle->timeout_reset
		749
		750	=item $handle->rtimeout_reset
		751
		752	=item $handle->wtimeout_reset
		753
		754	Reset the activity timeout, as if data was received or sent.
		755
		756	These methods are cheap to call.
		757
		758	=cut
		759
		760	for my $dir ("", "r", "w") {
		761	my $timeout = "${dir}timeout";
		762	my $tw = "_${dir}tw";
		763	my $on_timeout = "on_${dir}timeout";
		764	my $activity = "_${dir}activity";
		765	my $cb;
		766
		767	*$on_timeout = sub {
		768	$_[0]{$on_timeout} = $_[1];
		769	};
		770
		771	*$timeout = sub {
		772	my ($self, $new_value) = @_;
		773
		774	$self->{$timeout} = $new_value;
		775	delete $self->{$tw}; &$cb;
		776	};
		777
		778	*{"${dir}timeout_reset"} = sub {
		779	$_[0]{$activity} = AE::now;
		780	};
		781
		782	# main workhorse:
		783	# reset the timeout watcher, as neccessary
		784	# also check for time-outs
		785	$cb = sub {
		786	my ($self) = @_;
		787
		788	if ($self->{$timeout} && $self->{fh}) {
		789	my $NOW = AE::now;
		790
		791	# when would the timeout trigger?
		792	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		793
		794	# now or in the past already?
		795	if ($after <= 0) {
		796	$self->{$activity} = $NOW;
		797
		798	if ($self->{$on_timeout}) {
		799	$self->{$on_timeout}($self);
		800	} else {
		801	$self->_error (Errno::ETIMEDOUT);
		802	}
		803
		804	# callback could have changed timeout value, optimise
		805	return unless $self->{$timeout};
		806
		807	# calculate new after
		808	$after = $self->{$timeout};
		809	}
		810
		811	Scalar::Util::weaken $self;
		812	return unless $self; # ->error could have destroyed $self
		813
		814	$self->{$tw} ||= AE::timer $after, 0, sub {
		815	delete $self->{$tw};
		816	$cb->($self);
		817	};
		818	} else {
		819	delete $self->{$tw};
		820	}
		821	}
		822	}
		823
249	#############################################################################	824	#############################################################################
250		825
251	=back	826	=back
252		827
253	=head2 WRITE QUEUE	828	=head2 WRITE QUEUE
…		…
266	=item $handle->on_drain ($cb)	841	=item $handle->on_drain ($cb)
267		842
268	Sets the C<on_drain> callback or clears it (see the description of	843	Sets the C<on_drain> callback or clears it (see the description of
269	C<on_drain> in the constructor).	844	C<on_drain> in the constructor).
270		845
		846	This method may invoke callbacks (and therefore the handle might be
		847	destroyed after it returns).
		848
271	=cut	849	=cut
272		850
273	sub on_drain {	851	sub on_drain {
274	my ($self, $cb) = @_;	852	my ($self, $cb) = @_;
275		853
276	$self->{on_drain} = $cb;	854	$self->{on_drain} = $cb;
277		855
278	$cb->($self)	856	$cb->($self)
279	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	857	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280	}	858	}
281		859
282	=item $handle->push_write ($data)	860	=item $handle->push_write ($data)
283		861
284	Queues the given scalar to be written. You can push as much data as you	862	Queues the given scalar to be written. You can push as much data as you
285	want (only limited by the available memory), as C<AnyEvent::Handle>	863	want (only limited by the available memory), as C<AnyEvent::Handle>
286	buffers it independently of the kernel.	864	buffers it independently of the kernel.
287		865
		866	This method may invoke callbacks (and therefore the handle might be
		867	destroyed after it returns).
		868
288	=cut	869	=cut
289		870
290	sub _drain_wbuf {	871	sub _drain_wbuf {
291	my ($self) = @_;	872	my ($self) = @_;
292		873
293	if (!$self->{ww} && length $self->{wbuf}) {	874	if (!$self->{_ww} && length $self->{wbuf}) {
		875
294	Scalar::Util::weaken $self;	876	Scalar::Util::weaken $self;
		877
295	my $cb = sub {	878	my $cb = sub {
296	my $len = syswrite $self->{fh}, $self->{wbuf};	879	my $len = syswrite $self->{fh}, $self->{wbuf};
297		880
298	if ($len >= 0) {	881	if (defined $len) {
299	substr $self->{wbuf}, 0, $len, "";	882	substr $self->{wbuf}, 0, $len, "";
300		883
		884	$self->{_activity} = $self->{_wactivity} = AE::now;
		885
301	$self->{on_drain}($self)	886	$self->{on_drain}($self)
302	if $self->{low_water_mark} >= length $self->{wbuf}	887	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303	&& $self->{on_drain};	888	&& $self->{on_drain};
304		889
305	delete $self->{ww} unless length $self->{wbuf};	890	delete $self->{_ww} unless length $self->{wbuf};
306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEAGAIN) {	891	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307	$self->error;	892	$self->_error ($!, 1);
308	}	893	}
309	};	894	};
310		895
311	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	896	# try to write data immediately
		897	$cb->() unless $self->{autocork};
312		898
313	$cb->($self);	899	# if still data left in wbuf, we need to poll
		900	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		901	if length $self->{wbuf};
314	};	902	};
315	}	903	}
316		904
317	our %WH;	905	our %WH;
318		906
		907	# deprecated
319	sub register_write_type($$) {	908	sub register_write_type($$) {
320	$WH{$_[0]} = $_[1];	909	$WH{$_[0]} = $_[1];
321	}	910	}
322		911
323	sub push_write {	912	sub push_write {
324	my $self = shift;	913	my $self = shift;
325		914
326	if (@_ > 1) {	915	if (@_ > 1) {
327	my $type = shift;	916	my $type = shift;
328		917
		918	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
329	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	919	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
330	->($self, @_);	920	->($self, @_);
331	}	921	}
332		922
		923	# we downgrade here to avoid hard-to-track-down bugs,
		924	# and diagnose the problem earlier and better.
		925
333	if ($self->{filter_w}) {	926	if ($self->{tls}) {
334	$self->{filter_w}->($self, \$_[0]);	927	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		928	&_dotls ($self) if $self->{fh};
335	} else {	929	} else {
336	$self->{wbuf} .= $_[0];	930	utf8::downgrade $self->{wbuf} .= $_[0];
337	$self->_drain_wbuf;	931	$self->_drain_wbuf if $self->{fh};
338	}	932	}
339	}	933	}
340		934
341	=item $handle->push_write (type => @args)	935	=item $handle->push_write (type => @args)
342		936
343	=item $handle->unshift_write (type => @args)
344
345	Instead of formatting your data yourself, you can also let this module do	937	Instead of formatting your data yourself, you can also let this module
346	the job by specifying a type and type-specific arguments.	938	do the job by specifying a type and type-specific arguments. You
		939	can also specify the (fully qualified) name of a package, in which
		940	case AnyEvent tries to load the package and then expects to find the
		941	C<anyevent_write_type> function inside (see "custom write types", below).
347		942
348	Predefined types are (if you have ideas for additional types, feel free to	943	Predefined types are (if you have ideas for additional types, feel free to
349	drop by and tell us):	944	drop by and tell us):
350		945
351	=over 4	946	=over 4
…		…
353	=item netstring => $string	948	=item netstring => $string
354		949
355	Formats the given value as netstring	950	Formats the given value as netstring
356	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).	951	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357		952
358	=back
359
360	=cut	953	=cut
361		954
362	register_write_type netstring => sub {	955	register_write_type netstring => sub {
363	my ($self, $string) = @_;	956	my ($self, $string) = @_;
364		957
365	sprintf "%d:%s,", (length $string), $string	958	(length $string) . ":$string,"
366	};	959	};
367		960
368	=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args)	961	=item packstring => $format, $data
369		962
370	This function (not method) lets you add your own types to C<push_write>.	963	An octet string prefixed with an encoded length. The encoding C<$format>
		964	uses the same format as a Perl C<pack> format, but must specify a single
		965	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		966	optional C<!>, C<< < >> or C<< > >> modifier).
		967
		968	=cut
		969
		970	register_write_type packstring => sub {
		971	my ($self, $format, $string) = @_;
		972
		973	pack "$format/a*", $string
		974	};
		975
		976	=item json => $array_or_hashref
		977
		978	Encodes the given hash or array reference into a JSON object. Unless you
		979	provide your own JSON object, this means it will be encoded to JSON text
		980	in UTF-8.
		981
		982	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		983	one end of a handle and read them at the other end without using any
		984	additional framing.
		985
		986	The generated JSON text is guaranteed not to contain any newlines: While
		987	this module doesn't need delimiters after or between JSON texts to be
		988	able to read them, many other languages depend on that.
		989
		990	A simple RPC protocol that interoperates easily with others is to send
		991	JSON arrays (or objects, although arrays are usually the better choice as
		992	they mimic how function argument passing works) and a newline after each
		993	JSON text:
		994
		995	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		996	$handle->push_write ("\012");
		997
		998	An AnyEvent::Handle receiver would simply use the C<json> read type and
		999	rely on the fact that the newline will be skipped as leading whitespace:
		1000
		1001	$handle->push_read (json => sub { my $array = $_[1]; ... });
		1002
		1003	Other languages could read single lines terminated by a newline and pass
		1004	this line into their JSON decoder of choice.
		1005
		1006	=cut
		1007
		1008	sub json_coder() {
		1009	eval { require JSON::XS; JSON::XS->new->utf8 }
		1010	|| do { require JSON; JSON->new->utf8 }
		1011	}
		1012
		1013	register_write_type json => sub {
		1014	my ($self, $ref) = @_;
		1015
		1016	my $json = $self->{json} ||= json_coder;
		1017
		1018	$json->encode ($ref)
		1019	};
		1020
		1021	=item storable => $reference
		1022
		1023	Freezes the given reference using L<Storable> and writes it to the
		1024	handle. Uses the C<nfreeze> format.
		1025
		1026	=cut
		1027
		1028	register_write_type storable => sub {
		1029	my ($self, $ref) = @_;
		1030
		1031	require Storable;
		1032
		1033	pack "w/a*", Storable::nfreeze ($ref)
		1034	};
		1035
		1036	=back
		1037
		1038	=item $handle->push_shutdown
		1039
		1040	Sometimes you know you want to close the socket after writing your data
		1041	before it was actually written. One way to do that is to replace your
		1042	C<on_drain> handler by a callback that shuts down the socket (and set
		1043	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1044	replaces the C<on_drain> callback with:
		1045
		1046	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1047
		1048	This simply shuts down the write side and signals an EOF condition to the
		1049	the peer.
		1050
		1051	You can rely on the normal read queue and C<on_eof> handling
		1052	afterwards. This is the cleanest way to close a connection.
		1053
		1054	This method may invoke callbacks (and therefore the handle might be
		1055	destroyed after it returns).
		1056
		1057	=cut
		1058
		1059	sub push_shutdown {
		1060	my ($self) = @_;
		1061
		1062	delete $self->{low_water_mark};
		1063	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1064	}
		1065
		1066	=item custom write types - Package::anyevent_write_type $handle, @args
		1067
		1068	Instead of one of the predefined types, you can also specify the name of
		1069	a package. AnyEvent will try to load the package and then expects to find
		1070	a function named C<anyevent_write_type> inside. If it isn't found, it
		1071	progressively tries to load the parent package until it either finds the
		1072	function (good) or runs out of packages (bad).
		1073
371	Whenever the given C<type> is used, C<push_write> will invoke the code	1074	Whenever the given C<type> is used, C<push_write> will the function with
372	reference with the handle object and the remaining arguments.	1075	the handle object and the remaining arguments.
373		1076
374	The code reference is supposed to return a single octet string that will	1077	The function is supposed to return a single octet string that will be
375	be appended to the write buffer.	1078	appended to the write buffer, so you cna mentally treat this function as a
		1079	"arguments to on-the-wire-format" converter.
376		1080
377	Note that this is a function, and all types registered this way will be	1081	Example: implement a custom write type C<join> that joins the remaining
378	global, so try to use unique names.	1082	arguments using the first one.
		1083
		1084	$handle->push_write (My::Type => " ", 1,2,3);
		1085
		1086	# uses the following package, which can be defined in the "My::Type" or in
		1087	# the "My" modules to be auto-loaded, or just about anywhere when the
		1088	# My::Type::anyevent_write_type is defined before invoking it.
		1089
		1090	package My::Type;
		1091
		1092	sub anyevent_write_type {
		1093	my ($handle, $delim, @args) = @_;
		1094
		1095	join $delim, @args
		1096	}
379		1097
380	=cut	1098	=cut
381		1099
382	#############################################################################	1100	#############################################################################
383		1101
…		…
392	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1110	ways, the "simple" way, using only C<on_read> and the "complex" way, using
393	a queue.	1111	a queue.
394		1112
395	In the simple case, you just install an C<on_read> callback and whenever	1113	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	1114	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	1115	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
398	or not.	1116	leave the data there if you want to accumulate more (e.g. when only a
		1117	partial message has been received so far), or change the read queue with
		1118	e.g. C<push_read>.
399		1119
400	In the more complex case, you want to queue multiple callbacks. In this	1120	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	1121	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>,	1122	data arrives (also the first time it is queued) and removes it when it has
403	below).	1123	done its job (see C<push_read>, below).
404		1124
405	This way you can, for example, push three line-reads, followed by reading	1125	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.	1126	a chunk of data, and AnyEvent::Handle will execute them in order.
407		1127
408	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1128	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409	the specified number of bytes which give an XML datagram.	1129	the specified number of bytes which give an XML datagram.
410		1130
411	# in the default state, expect some header bytes	1131	# in the default state, expect some header bytes
412	$handle->on_read (sub {	1132	$handle->on_read (sub {
413	# some data is here, now queue the length-header-read (4 octets)	1133	# some data is here, now queue the length-header-read (4 octets)
414	shift->unshift_read_chunk (4, sub {	1134	shift->unshift_read (chunk => 4, sub {
415	# header arrived, decode	1135	# header arrived, decode
416	my $len = unpack "N", $_[1];	1136	my $len = unpack "N", $_[1];
417		1137
418	# now read the payload	1138	# now read the payload
419	shift->unshift_read_chunk ($len, sub {	1139	shift->unshift_read (chunk => $len, sub {
420	my $xml = $_[1];	1140	my $xml = $_[1];
421	# handle xml	1141	# handle xml
422	});	1142	});
423	});	1143	});
424	});	1144	});
425		1145
426	Example 2: Implement a client for a protocol that replies either with	1146	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	1147	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	1148	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	1149	just pipeline sending both requests and manipulate the queue as necessary
430	the callbacks:	1150	in the callbacks.
431		1151
432	# request one	1152	When the first callback is called and sees an "OK" response, it will
		1153	C<unshift> another line-read. This line-read will be queued I<before> the
		1154	64-byte chunk callback.
		1155
		1156	# request one, returns either "OK + extra line" or "ERROR"
433	$handle->push_write ("request 1\015\012");	1157	$handle->push_write ("request 1\015\012");
434		1158
435	# we expect "ERROR" or "OK" as response, so push a line read	1159	# we expect "ERROR" or "OK" as response, so push a line read
436	$handle->push_read_line (sub {	1160	$handle->push_read (line => sub {
437	# if we got an "OK", we have to _prepend_ another line,	1161	# if we got an "OK", we have to _prepend_ another line,
438	# so it will be read before the second request reads its 64 bytes	1162	# so it will be read before the second request reads its 64 bytes
439	# which are already in the queue when this callback is called	1163	# which are already in the queue when this callback is called
440	# we don't do this in case we got an error	1164	# we don't do this in case we got an error
441	if ($_[1] eq "OK") {	1165	if ($_[1] eq "OK") {
442	$_[0]->unshift_read_line (sub {	1166	$_[0]->unshift_read (line => sub {
443	my $response = $_[1];	1167	my $response = $_[1];
444	...	1168	...
445	});	1169	});
446	}	1170	}
447	});	1171	});
448		1172
449	# request two	1173	# request two, simply returns 64 octets
450	$handle->push_write ("request 2\015\012");	1174	$handle->push_write ("request 2\015\012");
451		1175
452	# simply read 64 bytes, always	1176	# simply read 64 bytes, always
453	$handle->push_read_chunk (64, sub {	1177	$handle->push_read (chunk => 64, sub {
454	my $response = $_[1];	1178	my $response = $_[1];
455	...	1179	...
456	});	1180	});
457		1181
458	=over 4	1182	=over 4
459		1183
460	=cut	1184	=cut
461		1185
462	sub _drain_rbuf {	1186	sub _drain_rbuf {
463	my ($self) = @_;	1187	my ($self) = @_;
		1188
		1189	# avoid recursion
		1190	return if $self->{_skip_drain_rbuf};
		1191	local $self->{_skip_drain_rbuf} = 1;
		1192
		1193	while () {
		1194	# we need to use a separate tls read buffer, as we must not receive data while
		1195	# we are draining the buffer, and this can only happen with TLS.
		1196	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1197	if exists $self->{_tls_rbuf};
		1198
		1199	my $len = length $self->{rbuf};
		1200
		1201	if (my $cb = shift @{ $self->{_queue} }) {
		1202	unless ($cb->($self)) {
		1203	# no progress can be made
		1204	# (not enough data and no data forthcoming)
		1205	$self->_error (Errno::EPIPE, 1), return
		1206	if $self->{_eof};
		1207
		1208	unshift @{ $self->{_queue} }, $cb;
		1209	last;
		1210	}
		1211	} elsif ($self->{on_read}) {
		1212	last unless $len;
		1213
		1214	$self->{on_read}($self);
		1215
		1216	if (
		1217	$len == length $self->{rbuf} # if no data has been consumed
		1218	&& !@{ $self->{_queue} } # and the queue is still empty
		1219	&& $self->{on_read} # but we still have on_read
		1220	) {
		1221	# no further data will arrive
		1222	# so no progress can be made
		1223	$self->_error (Errno::EPIPE, 1), return
		1224	if $self->{_eof};
		1225
		1226	last; # more data might arrive
		1227	}
		1228	} else {
		1229	# read side becomes idle
		1230	delete $self->{_rw} unless $self->{tls};
		1231	last;
		1232	}
		1233	}
		1234
		1235	if ($self->{_eof}) {
		1236	$self->{on_eof}
		1237	? $self->{on_eof}($self)
		1238	: $self->_error (0, 1, "Unexpected end-of-file");
		1239
		1240	return;
		1241	}
464		1242
465	if (	1243	if (
466	defined $self->{rbuf_max}	1244	defined $self->{rbuf_max}
467	&& $self->{rbuf_max} < length $self->{rbuf}	1245	&& $self->{rbuf_max} < length $self->{rbuf}
468	) {	1246	) {
469	$! = &Errno::ENOSPC; return $self->error;	1247	$self->_error (Errno::ENOSPC, 1), return;
470	}	1248	}
471		1249
472	return if $self->{in_drain};	1250	# may need to restart read watcher
473	local $self->{in_drain} = 1;	1251	unless ($self->{_rw}) {
474		1252	$self->start_read
475	while (my $len = length $self->{rbuf}) {	1253	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	}	1254	}
511	}	1255	}
512		1256
513	=item $handle->on_read ($cb)	1257	=item $handle->on_read ($cb)
514		1258
515	This replaces the currently set C<on_read> callback, or clears it (when	1259	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	1260	the new callback is C<undef>). See the description of C<on_read> in the
517	constructor.	1261	constructor.
518		1262
		1263	This method may invoke callbacks (and therefore the handle might be
		1264	destroyed after it returns).
		1265
519	=cut	1266	=cut
520		1267
521	sub on_read {	1268	sub on_read {
522	my ($self, $cb) = @_;	1269	my ($self, $cb) = @_;
523		1270
524	$self->{on_read} = $cb;	1271	$self->{on_read} = $cb;
		1272	$self->_drain_rbuf if $cb;
525	}	1273	}
526		1274
527	=item $handle->rbuf	1275	=item $handle->rbuf
528		1276
529	Returns the read buffer (as a modifiable lvalue).	1277	Returns the read buffer (as a modifiable lvalue).
530		1278
531	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1279	You can access the read buffer directly as the C<< ->{rbuf} >>
532	you want.	1280	member, if you want. However, the only operation allowed on the
		1281	read buffer (apart from looking at it) is removing data from its
		1282	beginning. Otherwise modifying or appending to it is not allowed and will
		1283	lead to hard-to-track-down bugs.
533		1284
534	NOTE: The read buffer should only be used or modified if the C<on_read>,	1285	NOTE: The read buffer should only be used or modified if the C<on_read>,
535	C<push_read> or C<unshift_read> methods are used. The other read methods	1286	C<push_read> or C<unshift_read> methods are used. The other read methods
536	automatically manage the read buffer.	1287	automatically manage the read buffer.
537		1288
…		…
558		1309
559	If enough data was available, then the callback must remove all data it is	1310	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	1311	interested in (which can be none at all) and return a true value. After returning
561	true, it will be removed from the queue.	1312	true, it will be removed from the queue.
562		1313
		1314	These methods may invoke callbacks (and therefore the handle might be
		1315	destroyed after it returns).
		1316
563	=cut	1317	=cut
564		1318
565	our %RH;	1319	our %RH;
566		1320
567	sub register_read_type($$) {	1321	sub register_read_type($$) {
…		…
573	my $cb = pop;	1327	my $cb = pop;
574		1328
575	if (@_) {	1329	if (@_) {
576	my $type = shift;	1330	my $type = shift;
577		1331
		1332	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
578	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1333	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
579	->($self, $cb, @_);	1334	->($self, $cb, @_);
580	}	1335	}
581		1336
582	push @{ $self->{queue} }, $cb;	1337	push @{ $self->{_queue} }, $cb;
583	$self->_drain_rbuf;	1338	$self->_drain_rbuf;
584	}	1339	}
585		1340
586	sub unshift_read {	1341	sub unshift_read {
587	my $self = shift;	1342	my $self = shift;
…		…
592		1347
593	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1348	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
594	->($self, $cb, @_);	1349	->($self, $cb, @_);
595	}	1350	}
596		1351
597
598	unshift @{ $self->{queue} }, $cb;	1352	unshift @{ $self->{_queue} }, $cb;
599	$self->_drain_rbuf;	1353	$self->_drain_rbuf;
600	}	1354	}
601		1355
602	=item $handle->push_read (type => @args, $cb)	1356	=item $handle->push_read (type => @args, $cb)
603		1357
604	=item $handle->unshift_read (type => @args, $cb)	1358	=item $handle->unshift_read (type => @args, $cb)
605		1359
606	Instead of providing a callback that parses the data itself you can chose	1360	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	1361	between a number of predefined parsing formats, for chunks of data, lines
608	etc.	1362	etc. You can also specify the (fully qualified) name of a package, in
		1363	which case AnyEvent tries to load the package and then expects to find the
		1364	C<anyevent_read_type> function inside (see "custom read types", below).
609		1365
610	Predefined types are (if you have ideas for additional types, feel free to	1366	Predefined types are (if you have ideas for additional types, feel free to
611	drop by and tell us):	1367	drop by and tell us):
612		1368
613	=over 4	1369	=over 4
614		1370
615	=item chunk => $octets, $cb->($self, $data)	1371	=item chunk => $octets, $cb->($handle, $data)
616		1372
617	Invoke the callback only once C<$octets> bytes have been read. Pass the	1373	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	1374	data read to the callback. The callback will never be called with less
619	data.	1375	data.
620		1376
…		…
634	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1390	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635	1	1391	1
636	}	1392	}
637	};	1393	};
638		1394
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, $eol)	1395	=item line => [$eol, ]$cb->($handle, $line, $eol)
649		1396
650	The callback will be called only once a full line (including the end of	1397	The callback will be called only once a full line (including the end of
651	line marker, C<$eol>) has been read. This line (excluding the end of line	1398	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	1399	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>).	1400	the end of line marker as the third argument (C<$eol>).
…		…
667	=cut	1414	=cut
668		1415
669	register_read_type line => sub {	1416	register_read_type line => sub {
670	my ($self, $cb, $eol) = @_;	1417	my ($self, $cb, $eol) = @_;
671		1418
672	$eol = qr|(\015?\012)| if @_ < 3;	1419	if (@_ < 3) {
		1420	# this is more than twice as fast as the generic code below
		1421	sub {
		1422	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1423
		1424	$cb->($_[0], $1, $2);
		1425	1
		1426	}
		1427	} else {
673	$eol = quotemeta $eol unless ref $eol;	1428	$eol = quotemeta $eol unless ref $eol;
674	$eol = qr|^(.*?)($eol)|s;	1429	$eol = qr|^(.*?)($eol)|s;
		1430
		1431	sub {
		1432	$_[0]{rbuf} =~ s/$eol// or return;
		1433
		1434	$cb->($_[0], $1, $2);
		1435	1
		1436	}
		1437	}
		1438	};
		1439
		1440	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1441
		1442	Makes a regex match against the regex object C<$accept> and returns
		1443	everything up to and including the match.
		1444
		1445	Example: read a single line terminated by '\n'.
		1446
		1447	$handle->push_read (regex => qr<\n>, sub { ... });
		1448
		1449	If C<$reject> is given and not undef, then it determines when the data is
		1450	to be rejected: it is matched against the data when the C<$accept> regex
		1451	does not match and generates an C<EBADMSG> error when it matches. This is
		1452	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1453	receive buffer overflow).
		1454
		1455	Example: expect a single decimal number followed by whitespace, reject
		1456	anything else (not the use of an anchor).
		1457
		1458	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1459
		1460	If C<$skip> is given and not C<undef>, then it will be matched against
		1461	the receive buffer when neither C<$accept> nor C<$reject> match,
		1462	and everything preceding and including the match will be accepted
		1463	unconditionally. This is useful to skip large amounts of data that you
		1464	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1465	have to start matching from the beginning. This is purely an optimisation
		1466	and is usually worth only when you expect more than a few kilobytes.
		1467
		1468	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1469	expect the header to be very large (it isn't in practise, but...), we use
		1470	a skip regex to skip initial portions. The skip regex is tricky in that
		1471	it only accepts something not ending in either \015 or \012, as these are
		1472	required for the accept regex.
		1473
		1474	$handle->push_read (regex =>
		1475	qr<\015\012\015\012>,
		1476	undef, # no reject
		1477	qr<^.*[^\015\012]>,
		1478	sub { ... });
		1479
		1480	=cut
		1481
		1482	register_read_type regex => sub {
		1483	my ($self, $cb, $accept, $reject, $skip) = @_;
		1484
		1485	my $data;
		1486	my $rbuf = \$self->{rbuf};
675		1487
676	sub {	1488	sub {
677	$_[0]{rbuf} =~ s/$eol// or return;	1489	# accept
678		1490	if ($$rbuf =~ $accept) {
679	$cb->($_[0], $1, $2);	1491	$data .= substr $$rbuf, 0, $+[0], "";
		1492	$cb->($self, $data);
		1493	return 1;
		1494	}
680	1	1495
		1496	# reject
		1497	if ($reject && $$rbuf =~ $reject) {
		1498	$self->_error (Errno::EBADMSG);
		1499	}
		1500
		1501	# skip
		1502	if ($skip && $$rbuf =~ $skip) {
		1503	$data .= substr $$rbuf, 0, $+[0], "";
		1504	}
		1505
		1506	()
681	}	1507	}
682	};	1508	};
683		1509
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)	1510	=item netstring => $cb->($handle, $string)
696		1511
697	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).	1512	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698		1513
699	Throws an error with C<$!> set to EBADMSG on format violations.	1514	Throws an error with C<$!> set to EBADMSG on format violations.
700		1515
…		…
704	my ($self, $cb) = @_;	1519	my ($self, $cb) = @_;
705		1520
706	sub {	1521	sub {
707	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1522	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708	if ($_[0]{rbuf} =~ /[^0-9]/) {	1523	if ($_[0]{rbuf} =~ /[^0-9]/) {
709	$! = &Errno::EBADMSG;	1524	$self->_error (Errno::EBADMSG);
710	$self->error;
711	}	1525	}
712	return;	1526	return;
713	}	1527	}
714		1528
715	my $len = $1;	1529	my $len = $1;
…		…
718	my $string = $_[1];	1532	my $string = $_[1];
719	$_[0]->unshift_read (chunk => 1, sub {	1533	$_[0]->unshift_read (chunk => 1, sub {
720	if ($_[1] eq ",") {	1534	if ($_[1] eq ",") {
721	$cb->($_[0], $string);	1535	$cb->($_[0], $string);
722	} else {	1536	} else {
723	$! = &Errno::EBADMSG;
724	$self->error;	1537	$self->_error (Errno::EBADMSG);
725	}	1538	}
726	});	1539	});
727	});	1540	});
728		1541
729	1	1542	1
730	}	1543	}
731	};	1544	};
732		1545
		1546	=item packstring => $format, $cb->($handle, $string)
		1547
		1548	An octet string prefixed with an encoded length. The encoding C<$format>
		1549	uses the same format as a Perl C<pack> format, but must specify a single
		1550	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1551	optional C<!>, C<< < >> or C<< > >> modifier).
		1552
		1553	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1554	EPP uses a prefix of C<N> (4 octtes).
		1555
		1556	Example: read a block of data prefixed by its length in BER-encoded
		1557	format (very efficient).
		1558
		1559	$handle->push_read (packstring => "w", sub {
		1560	my ($handle, $data) = @_;
		1561	});
		1562
		1563	=cut
		1564
		1565	register_read_type packstring => sub {
		1566	my ($self, $cb, $format) = @_;
		1567
		1568	sub {
		1569	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1570	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1571	or return;
		1572
		1573	$format = length pack $format, $len;
		1574
		1575	# bypass unshift if we already have the remaining chunk
		1576	if ($format + $len <= length $_[0]{rbuf}) {
		1577	my $data = substr $_[0]{rbuf}, $format, $len;
		1578	substr $_[0]{rbuf}, 0, $format + $len, "";
		1579	$cb->($_[0], $data);
		1580	} else {
		1581	# remove prefix
		1582	substr $_[0]{rbuf}, 0, $format, "";
		1583
		1584	# read remaining chunk
		1585	$_[0]->unshift_read (chunk => $len, $cb);
		1586	}
		1587
		1588	1
		1589	}
		1590	};
		1591
		1592	=item json => $cb->($handle, $hash_or_arrayref)
		1593
		1594	Reads a JSON object or array, decodes it and passes it to the
		1595	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1596
		1597	If a C<json> object was passed to the constructor, then that will be used
		1598	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1599
		1600	This read type uses the incremental parser available with JSON version
		1601	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1602	dependency on your own: this module will load the JSON module, but
		1603	AnyEvent does not depend on it itself.
		1604
		1605	Since JSON texts are fully self-delimiting, the C<json> read and write
		1606	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1607	the C<json> write type description, above, for an actual example.
		1608
		1609	=cut
		1610
		1611	register_read_type json => sub {
		1612	my ($self, $cb) = @_;
		1613
		1614	my $json = $self->{json} ||= json_coder;
		1615
		1616	my $data;
		1617	my $rbuf = \$self->{rbuf};
		1618
		1619	sub {
		1620	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1621
		1622	if ($ref) {
		1623	$self->{rbuf} = $json->incr_text;
		1624	$json->incr_text = "";
		1625	$cb->($self, $ref);
		1626
		1627	1
		1628	} elsif ($@) {
		1629	# error case
		1630	$json->incr_skip;
		1631
		1632	$self->{rbuf} = $json->incr_text;
		1633	$json->incr_text = "";
		1634
		1635	$self->_error (Errno::EBADMSG);
		1636
		1637	()
		1638	} else {
		1639	$self->{rbuf} = "";
		1640
		1641	()
		1642	}
		1643	}
		1644	};
		1645
		1646	=item storable => $cb->($handle, $ref)
		1647
		1648	Deserialises a L<Storable> frozen representation as written by the
		1649	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1650	data).
		1651
		1652	Raises C<EBADMSG> error if the data could not be decoded.
		1653
		1654	=cut
		1655
		1656	register_read_type storable => sub {
		1657	my ($self, $cb) = @_;
		1658
		1659	require Storable;
		1660
		1661	sub {
		1662	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1663	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1664	or return;
		1665
		1666	my $format = length pack "w", $len;
		1667
		1668	# bypass unshift if we already have the remaining chunk
		1669	if ($format + $len <= length $_[0]{rbuf}) {
		1670	my $data = substr $_[0]{rbuf}, $format, $len;
		1671	substr $_[0]{rbuf}, 0, $format + $len, "";
		1672	$cb->($_[0], Storable::thaw ($data));
		1673	} else {
		1674	# remove prefix
		1675	substr $_[0]{rbuf}, 0, $format, "";
		1676
		1677	# read remaining chunk
		1678	$_[0]->unshift_read (chunk => $len, sub {
		1679	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1680	$cb->($_[0], $ref);
		1681	} else {
		1682	$self->_error (Errno::EBADMSG);
		1683	}
		1684	});
		1685	}
		1686
		1687	1
		1688	}
		1689	};
		1690
733	=back	1691	=back
734		1692
735	=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args)	1693	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
736		1694
737	This function (not method) lets you add your own types to C<push_read>.	1695	Instead of one of the predefined types, you can also specify the name
		1696	of a package. AnyEvent will try to load the package and then expects to
		1697	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1698	progressively tries to load the parent package until it either finds the
		1699	function (good) or runs out of packages (bad).
738		1700
739	Whenever the given C<type> is used, C<push_read> will invoke the code	1701	Whenever this type is used, C<push_read> will invoke the function with the
740	reference with the handle object, the callback and the remaining	1702	handle object, the original callback and the remaining arguments.
741	arguments.
742		1703
743	The code reference is supposed to return a callback (usually a closure)	1704	The function is supposed to return a callback (usually a closure) that
744	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1705	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1706	mentally treat the function as a "configurable read type to read callback"
		1707	converter.
745		1708
746	It should invoke the passed callback when it is done reading (remember to	1709	It should invoke the original callback when it is done reading (remember
747	pass C<$self> as first argument as all other callbacks do that).	1710	to pass C<$handle> as first argument as all other callbacks do that,
		1711	although there is no strict requirement on this).
748		1712
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>,	1713	For examples, see the source of this module (F<perldoc -m
753	search for C<register_read_type>)).	1714	AnyEvent::Handle>, search for C<register_read_type>)).
754		1715
755	=item $handle->stop_read	1716	=item $handle->stop_read
756		1717
757	=item $handle->start_read	1718	=item $handle->start_read
758		1719
759	In rare cases you actually do not want to read anything from the	1720	In rare cases you actually do not want to read anything from the
760	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1721	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761	any queued callbacks will be executed then. To start reading again, call	1722	any queued callbacks will be executed then. To start reading again, call
762	C<start_read>.	1723	C<start_read>.
763		1724
		1725	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1726	you change the C<on_read> callback or push/unshift a read callback, and it
		1727	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1728	there are any read requests in the queue.
		1729
		1730	These methods will have no effect when in TLS mode (as TLS doesn't support
		1731	half-duplex connections).
		1732
764	=cut	1733	=cut
765		1734
766	sub stop_read {	1735	sub stop_read {
767	my ($self) = @_;	1736	my ($self) = @_;
768		1737
769	delete $self->{rw};	1738	delete $self->{_rw} unless $self->{tls};
770	}	1739	}
771		1740
772	sub start_read {	1741	sub start_read {
773	my ($self) = @_;	1742	my ($self) = @_;
774		1743
775	unless ($self->{rw} || $self->{eof}) {	1744	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
776	Scalar::Util::weaken $self;	1745	Scalar::Util::weaken $self;
777		1746
778	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1747	$self->{_rw} = AE::io $self->{fh}, 0, sub {
779	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1748	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1749	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781		1750
782	if ($len > 0) {	1751	if ($len > 0) {
783	$self->{filter_r}	1752	$self->{_activity} = $self->{_ractivity} = AE::now;
784	? $self->{filter_r}->($self, $rbuf)	1753
		1754	if ($self->{tls}) {
		1755	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1756
		1757	&_dotls ($self);
		1758	} else {
785	: $self->_drain_rbuf;	1759	$self->_drain_rbuf;
		1760	}
786		1761
787	} elsif (defined $len) {	1762	} elsif (defined $len) {
788	delete $self->{rw};	1763	delete $self->{_rw};
789	$self->{eof} = 1;	1764	$self->{_eof} = 1;
790	$self->_drain_rbuf;	1765	$self->_drain_rbuf;
791		1766
792	} elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAEAGAIN) {	1767	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793	return $self->error;	1768	return $self->_error ($!, 1);
794	}	1769	}
795	});	1770	};
796	}	1771	}
797	}	1772	}
798		1773
		1774	our $ERROR_SYSCALL;
		1775	our $ERROR_WANT_READ;
		1776
		1777	sub _tls_error {
		1778	my ($self, $err) = @_;
		1779
		1780	return $self->_error ($!, 1)
		1781	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1782
		1783	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1784
		1785	# reduce error string to look less scary
		1786	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1787
		1788	if ($self->{_on_starttls}) {
		1789	(delete $self->{_on_starttls})->($self, undef, $err);
		1790	&_freetls;
		1791	} else {
		1792	&_freetls;
		1793	$self->_error (Errno::EPROTO, 1, $err);
		1794	}
		1795	}
		1796
		1797	# poll the write BIO and send the data if applicable
		1798	# also decode read data if possible
		1799	# this is basiclaly our TLS state machine
		1800	# more efficient implementations are possible with openssl,
		1801	# but not with the buggy and incomplete Net::SSLeay.
799	sub _dotls {	1802	sub _dotls {
800	my ($self) = @_;	1803	my ($self) = @_;
801		1804
		1805	my $tmp;
		1806
802	if (length $self->{tls_wbuf}) {	1807	if (length $self->{_tls_wbuf}) {
803	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1808	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804	substr $self->{tls_wbuf}, 0, $len, "";	1809	substr $self->{_tls_wbuf}, 0, $tmp, "";
805	}	1810	}
806	}
807		1811
		1812	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1813	return $self->_tls_error ($tmp)
		1814	if $tmp != $ERROR_WANT_READ
		1815	&& ($tmp != $ERROR_SYSCALL || $!);
		1816	}
		1817
808	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1818	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1819	unless (length $tmp) {
		1820	$self->{_on_starttls}
		1821	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1822	&_freetls;
		1823
		1824	if ($self->{on_stoptls}) {
		1825	$self->{on_stoptls}($self);
		1826	return;
		1827	} else {
		1828	# let's treat SSL-eof as we treat normal EOF
		1829	delete $self->{_rw};
		1830	$self->{_eof} = 1;
		1831	}
		1832	}
		1833
		1834	$self->{_tls_rbuf} .= $tmp;
		1835	$self->_drain_rbuf;
		1836	$self->{tls} or return; # tls session might have gone away in callback
		1837	}
		1838
		1839	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1840	return $self->_tls_error ($tmp)
		1841	if $tmp != $ERROR_WANT_READ
		1842	&& ($tmp != $ERROR_SYSCALL || $!);
		1843
		1844	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809	$self->{wbuf} .= $buf;	1845	$self->{wbuf} .= $tmp;
810	$self->_drain_wbuf;	1846	$self->_drain_wbuf;
		1847	$self->{tls} or return; # tls session might have gone away in callback
811	}	1848	}
812		1849
813	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {	1850	$self->{_on_starttls}
814	$self->{rbuf} .= $buf;	1851	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
815	$self->_drain_rbuf;	1852	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	}	1853	}
831		1854
832	=item $handle->starttls ($tls[, $tls_ctx])	1855	=item $handle->starttls ($tls[, $tls_ctx])
833		1856
834	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1857	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	1858	object is created, you can also do that at a later time by calling
836	C<starttls>.	1859	C<starttls>.
837		1860
		1861	Starting TLS is currently an asynchronous operation - when you push some
		1862	write data and then call C<< ->starttls >> then TLS negotiation will start
		1863	immediately, after which the queued write data is then sent.
		1864
838	The first argument is the same as the C<tls> constructor argument (either	1865	The first argument is the same as the C<tls> constructor argument (either
839	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1866	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840		1867
841	The second argument is the optional C<Net::SSLeay::CTX> object that is	1868	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.	1869	when AnyEvent::Handle has to create its own TLS connection object, or
		1870	a hash reference with C<< key => value >> pairs that will be used to
		1871	construct a new context.
843		1872
844	=cut	1873	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1874	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1875	changed to your liking. Note that the handshake might have already started
		1876	when this function returns.
845		1877
846	# TODO: maybe document...	1878	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1879	handshakes on the same stream. Best do not attempt to use the stream after
		1880	stopping TLS.
		1881
		1882	This method may invoke callbacks (and therefore the handle might be
		1883	destroyed after it returns).
		1884
		1885	=cut
		1886
		1887	our %TLS_CACHE; #TODO not yet documented, should we?
		1888
847	sub starttls {	1889	sub starttls {
848	my ($self, $ssl, $ctx) = @_;	1890	my ($self, $tls, $ctx) = @_;
849		1891
850	$self->stoptls;	1892	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1893	if $self->{tls};
851		1894
852	if ($ssl eq "accept") {	1895	$self->{tls} = $tls;
853	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1896	$self->{tls_ctx} = $ctx if @_ > 2;
854	Net::SSLeay::set_accept_state ($ssl);	1897
855	} elsif ($ssl eq "connect") {	1898	return unless $self->{fh};
856	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1899
857	Net::SSLeay::set_connect_state ($ssl);	1900	require Net::SSLeay;
		1901
		1902	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1903	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1904
		1905	$tls = delete $self->{tls};
		1906	$ctx = $self->{tls_ctx};
		1907
		1908	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1909
		1910	if ("HASH" eq ref $ctx) {
		1911	require AnyEvent::TLS;
		1912
		1913	if ($ctx->{cache}) {
		1914	my $key = $ctx+0;
		1915	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1916	} else {
		1917	$ctx = new AnyEvent::TLS %$ctx;
		1918	}
		1919	}
858	}	1920
859		1921	$self->{tls_ctx} = $ctx || TLS_CTX ();
860	$self->{tls} = $ssl;	1922	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
861		1923
862	# basically, this is deep magic (because SSL_read should have the same issues)	1924	# basically, this is deep magic (because SSL_read should have the same issues)
863	# but the openssl maintainers basically said: "trust us, it just works".	1925	# but the openssl maintainers basically said: "trust us, it just works".
864	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1926	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
865	# and mismaintained ssleay-module doesn't even offer them).	1927	# and mismaintained ssleay-module doesn't even offer them).
866	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1928	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1929	#
		1930	# in short: this is a mess.
		1931	#
		1932	# note that we do not try to keep the length constant between writes as we are required to do.
		1933	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1934	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1935	# have identity issues in that area.
867	Net::SSLeay::CTX_set_mode ($self->{tls},	1936	# Net::SSLeay::CTX_set_mode ($ssl,
868	(eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	1937	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869	| (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	1938	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1939	Net::SSLeay::CTX_set_mode ($tls, 1|2);
870		1940
871	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1941	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1942	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873		1943
		1944	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1945
874	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	1946	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
875		1947
876	$self->{filter_w} = sub {	1948	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
877	$_[0]{tls_wbuf} .= ${$_[1]};	1949	if $self->{on_starttls};
878	&_dotls;	1950
879	};	1951	&_dotls; # need to trigger the initial handshake
880	$self->{filter_r} = sub {	1952	$self->start_read; # make sure we actually do read
881	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882	&_dotls;
883	};
884	}	1953	}
885		1954
886	=item $handle->stoptls	1955	=item $handle->stoptls
887		1956
888	Destroys the SSL connection, if any. Partial read or write data will be	1957	Shuts down the SSL connection - this makes a proper EOF handshake by
889	lost.	1958	sending a close notify to the other side, but since OpenSSL doesn't
		1959	support non-blocking shut downs, it is not guaranteed that you can re-use
		1960	the stream afterwards.
		1961
		1962	This method may invoke callbacks (and therefore the handle might be
		1963	destroyed after it returns).
890		1964
891	=cut	1965	=cut
892		1966
893	sub stoptls {	1967	sub stoptls {
894	my ($self) = @_;	1968	my ($self) = @_;
895		1969
896	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	1970	if ($self->{tls} && $self->{fh}) {
897	delete $self->{tls_rbio};	1971	Net::SSLeay::shutdown ($self->{tls});
898	delete $self->{tls_wbio};	1972
899	delete $self->{tls_wbuf};	1973	&_dotls;
900	delete $self->{filter_r};	1974
901	delete $self->{filter_w};	1975	# # we don't give a shit. no, we do, but we can't. no...#d#
		1976	# # we, we... have to use openssl :/#d#
		1977	# &_freetls;#d#
		1978	}
		1979	}
		1980
		1981	sub _freetls {
		1982	my ($self) = @_;
		1983
		1984	return unless $self->{tls};
		1985
		1986	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1987	if $self->{tls} > 0;
		1988
		1989	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
902	}	1990	}
903		1991
904	sub DESTROY {	1992	sub DESTROY {
905	my $self = shift;	1993	my ($self) = @_;
906		1994
907	$self->stoptls;	1995	&_freetls;
		1996
		1997	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1998
		1999	if ($linger && length $self->{wbuf} && $self->{fh}) {
		2000	my $fh = delete $self->{fh};
		2001	my $wbuf = delete $self->{wbuf};
		2002
		2003	my @linger;
		2004
		2005	push @linger, AE::io $fh, 1, sub {
		2006	my $len = syswrite $fh, $wbuf, length $wbuf;
		2007
		2008	if ($len > 0) {
		2009	substr $wbuf, 0, $len, "";
		2010	} else {
		2011	@linger = (); # end
		2012	}
		2013	};
		2014	push @linger, AE::timer $linger, 0, sub {
		2015	@linger = ();
		2016	};
		2017	}
908	}	2018	}
		2019
		2020	=item $handle->destroy
		2021
		2022	Shuts down the handle object as much as possible - this call ensures that
		2023	no further callbacks will be invoked and as many resources as possible
		2024	will be freed. Any method you will call on the handle object after
		2025	destroying it in this way will be silently ignored (and it will return the
		2026	empty list).
		2027
		2028	Normally, you can just "forget" any references to an AnyEvent::Handle
		2029	object and it will simply shut down. This works in fatal error and EOF
		2030	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2031	callback, so when you want to destroy the AnyEvent::Handle object from
		2032	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2033	that case.
		2034
		2035	Destroying the handle object in this way has the advantage that callbacks
		2036	will be removed as well, so if those are the only reference holders (as
		2037	is common), then one doesn't need to do anything special to break any
		2038	reference cycles.
		2039
		2040	The handle might still linger in the background and write out remaining
		2041	data, as specified by the C<linger> option, however.
		2042
		2043	=cut
		2044
		2045	sub destroy {
		2046	my ($self) = @_;
		2047
		2048	$self->DESTROY;
		2049	%$self = ();
		2050	bless $self, "AnyEvent::Handle::destroyed";
		2051	}
		2052
		2053	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2054	#nop
		2055	}
		2056
		2057	=item $handle->destroyed
		2058
		2059	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2060	->destroy >>, true otherwise.
		2061
		2062	Can be useful to decide whether the handle is still valid after some
		2063	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2064	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2065	can destroy the handle, so work can be avoided by checking sometimes:
		2066
		2067	$hdl->starttls ("accept");
		2068	return if $hdl->destroyed;
		2069	$hdl->push_write (...
		2070
		2071	Note that the call to C<push_write> will silently be ignored if the handle
		2072	has been destroyed, so often you can just ignore the possibility of the
		2073	handle being destroyed.
		2074
		2075	=cut
		2076
		2077	sub destroyed { 0 }
		2078	sub AnyEvent::Handle::destroyed::destroyed { 1 }
909		2079
910	=item AnyEvent::Handle::TLS_CTX	2080	=item AnyEvent::Handle::TLS_CTX
911		2081
912	This function creates and returns the Net::SSLeay::CTX object used by	2082	This function creates and returns the AnyEvent::TLS object used by default
913	default for TLS mode.	2083	for TLS mode.
914		2084
915	The context is created like this:	2085	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		2086
925	=cut	2087	=cut
926		2088
927	our $TLS_CTX;	2089	our $TLS_CTX;
928		2090
929	sub TLS_CTX() {	2091	sub TLS_CTX() {
930	$TLS_CTX || do {	2092	$TLS_CTX ||= do {
931	require Net::SSLeay;	2093	require AnyEvent::TLS;
932		2094
933	Net::SSLeay::load_error_strings ();	2095	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	$TLS_CTX
942	}	2096	}
943	}	2097	}
944		2098
945	=back	2099	=back
946		2100
		2101
		2102	=head1 NONFREQUENTLY ASKED QUESTIONS
		2103
		2104	=over 4
		2105
		2106	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2107	still get further invocations!
		2108
		2109	That's because AnyEvent::Handle keeps a reference to itself when handling
		2110	read or write callbacks.
		2111
		2112	It is only safe to "forget" the reference inside EOF or error callbacks,
		2113	from within all other callbacks, you need to explicitly call the C<<
		2114	->destroy >> method.
		2115
		2116	=item I get different callback invocations in TLS mode/Why can't I pause
		2117	reading?
		2118
		2119	Unlike, say, TCP, TLS connections do not consist of two independent
		2120	communication channels, one for each direction. Or put differently. The
		2121	read and write directions are not independent of each other: you cannot
		2122	write data unless you are also prepared to read, and vice versa.
		2123
		2124	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2125	callback invocations when you are not expecting any read data - the reason
		2126	is that AnyEvent::Handle always reads in TLS mode.
		2127
		2128	During the connection, you have to make sure that you always have a
		2129	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2130	connection (or when you no longer want to use it) you can call the
		2131	C<destroy> method.
		2132
		2133	=item How do I read data until the other side closes the connection?
		2134
		2135	If you just want to read your data into a perl scalar, the easiest way
		2136	to achieve this is by setting an C<on_read> callback that does nothing,
		2137	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2138	will be in C<$_[0]{rbuf}>:
		2139
		2140	$handle->on_read (sub { });
		2141	$handle->on_eof (undef);
		2142	$handle->on_error (sub {
		2143	my $data = delete $_[0]{rbuf};
		2144	});
		2145
		2146	The reason to use C<on_error> is that TCP connections, due to latencies
		2147	and packets loss, might get closed quite violently with an error, when in
		2148	fact, all data has been received.
		2149
		2150	It is usually better to use acknowledgements when transferring data,
		2151	to make sure the other side hasn't just died and you got the data
		2152	intact. This is also one reason why so many internet protocols have an
		2153	explicit QUIT command.
		2154
		2155	=item I don't want to destroy the handle too early - how do I wait until
		2156	all data has been written?
		2157
		2158	After writing your last bits of data, set the C<on_drain> callback
		2159	and destroy the handle in there - with the default setting of
		2160	C<low_water_mark> this will be called precisely when all data has been
		2161	written to the socket:
		2162
		2163	$handle->push_write (...);
		2164	$handle->on_drain (sub {
		2165	warn "all data submitted to the kernel\n";
		2166	undef $handle;
		2167	});
		2168
		2169	If you just want to queue some data and then signal EOF to the other side,
		2170	consider using C<< ->push_shutdown >> instead.
		2171
		2172	=item I want to contact a TLS/SSL server, I don't care about security.
		2173
		2174	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2175	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2176	parameter:
		2177
		2178	tcp_connect $host, $port, sub {
		2179	my ($fh) = @_;
		2180
		2181	my $handle = new AnyEvent::Handle
		2182	fh => $fh,
		2183	tls => "connect",
		2184	on_error => sub { ... };
		2185
		2186	$handle->push_write (...);
		2187	};
		2188
		2189	=item I want to contact a TLS/SSL server, I do care about security.
		2190
		2191	Then you should additionally enable certificate verification, including
		2192	peername verification, if the protocol you use supports it (see
		2193	L<AnyEvent::TLS>, C<verify_peername>).
		2194
		2195	E.g. for HTTPS:
		2196
		2197	tcp_connect $host, $port, sub {
		2198	my ($fh) = @_;
		2199
		2200	my $handle = new AnyEvent::Handle
		2201	fh => $fh,
		2202	peername => $host,
		2203	tls => "connect",
		2204	tls_ctx => { verify => 1, verify_peername => "https" },
		2205	...
		2206
		2207	Note that you must specify the hostname you connected to (or whatever
		2208	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2209	peername verification will be done.
		2210
		2211	The above will use the system-dependent default set of trusted CA
		2212	certificates. If you want to check against a specific CA, add the
		2213	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2214
		2215	tls_ctx => {
		2216	verify => 1,
		2217	verify_peername => "https",
		2218	ca_file => "my-ca-cert.pem",
		2219	},
		2220
		2221	=item I want to create a TLS/SSL server, how do I do that?
		2222
		2223	Well, you first need to get a server certificate and key. You have
		2224	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2225	self-signed certificate (cheap. check the search engine of your choice,
		2226	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2227	nice program for that purpose).
		2228
		2229	Then create a file with your private key (in PEM format, see
		2230	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2231	file should then look like this:
		2232
		2233	-----BEGIN RSA PRIVATE KEY-----
		2234	...header data
		2235	... lots of base64'y-stuff
		2236	-----END RSA PRIVATE KEY-----
		2237
		2238	-----BEGIN CERTIFICATE-----
		2239	... lots of base64'y-stuff
		2240	-----END CERTIFICATE-----
		2241
		2242	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2243	specify this file as C<cert_file>:
		2244
		2245	tcp_server undef, $port, sub {
		2246	my ($fh) = @_;
		2247
		2248	my $handle = new AnyEvent::Handle
		2249	fh => $fh,
		2250	tls => "accept",
		2251	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2252	...
		2253
		2254	When you have intermediate CA certificates that your clients might not
		2255	know about, just append them to the C<cert_file>.
		2256
		2257	=back
		2258
		2259
		2260	=head1 SUBCLASSING AnyEvent::Handle
		2261
		2262	In many cases, you might want to subclass AnyEvent::Handle.
		2263
		2264	To make this easier, a given version of AnyEvent::Handle uses these
		2265	conventions:
		2266
		2267	=over 4
		2268
		2269	=item * all constructor arguments become object members.
		2270
		2271	At least initially, when you pass a C<tls>-argument to the constructor it
		2272	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2273	mutated later on (for example C<tls> will hold the TLS connection object).
		2274
		2275	=item * other object member names are prefixed with an C<_>.
		2276
		2277	All object members not explicitly documented (internal use) are prefixed
		2278	with an underscore character, so the remaining non-C<_>-namespace is free
		2279	for use for subclasses.
		2280
		2281	=item * all members not documented here and not prefixed with an underscore
		2282	are free to use in subclasses.
		2283
		2284	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2285	member variables, but thats just life, at least it is documented.
		2286
		2287	=back
		2288
947	=head1 AUTHOR	2289	=head1 AUTHOR
948		2290
949	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2291	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950		2292
951	=cut	2293	=cut

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