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Revision 1.34 by root, Mon May 26 03:27:52 2008 UTC vs.
Revision 1.200 by root, Tue Oct 12 06:47:54 2010 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict;
5
6	use AnyEvent ();
7	use AnyEvent::Util qw(WSAWOULDBLOCK);
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 is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
		40
54	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
55	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
56	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
57		47
58	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
59	argument.	49	argument.
60		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
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 that the
		124	default timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The peer's numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	If, for some reason, the handle is not acceptable, calling C<$retry>
		134	will continue with the next connection target (in case of multi-homed
		135	hosts or SRV records there can be multiple connection endpoints). At the
		136	time it is called the read and write queues, eof status, tls status and
		137	similar properties of the handle will have been reset.
		138
		139	In most cases, you should ignore the C<$retry> parameter.
		140
		141	=item on_connect_error => $cb->($handle, $message)
		142
		143	This callback is called when the connection could not be
		144	established. C<$!> will contain the relevant error code, and C<$message> a
		145	message describing it (usually the same as C<"$!">).
		146
		147	If this callback isn't specified, then C<on_error> will be called with a
		148	fatal error instead.
		149
		150	=back
		151
		152	=item on_error => $cb->($handle, $fatal, $message)
		153
88	This is the fatal error callback, that is called when, well, a fatal error	154	This is the error callback, which is called when, well, some error
89	occurs, such as not being able to resolve the hostname, failure to connect	155	occured, such as not being able to resolve the hostname, failure to
90	or a read error.	156	connect, or a read error.
91		157
92	The object will not be in a usable state when this callback has been	158	Some errors are fatal (which is indicated by C<$fatal> being true). On
93	called.	159	fatal errors the handle object will be destroyed (by a call to C<< ->
		160	destroy >>) after invoking the error callback (which means you are free to
		161	examine the handle object). Examples of fatal errors are an EOF condition
		162	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		163	cases where the other side can close the connection at will, it is
		164	often easiest to not report C<EPIPE> errors in this callback.
94		165
		166	AnyEvent::Handle tries to find an appropriate error code for you to check
		167	against, but in some cases (TLS errors), this does not work well. It is
		168	recommended to always output the C<$message> argument in human-readable
		169	error messages (it's usually the same as C<"$!">).
		170
		171	Non-fatal errors can be retried by returning, but it is recommended
		172	to simply ignore this parameter and instead abondon the handle object
		173	when this callback is invoked. Examples of non-fatal errors are timeouts
		174	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		175
95	On callback entrance, the value of C<$!> contains the operating system	176	On entry to the callback, the value of C<$!> contains the operating
96	error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>).	177	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		178	C<EPROTO>).
97		179
98	While not mandatory, it is I<highly> recommended to set this callback, as	180	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	181	you will not be notified of errors otherwise. The default just calls
100	die.	182	C<croak>.
101		183
102	=item on_read => $cb->($self)	184	=item on_read => $cb->($handle)
103		185
104	This sets the default read callback, which is called when data arrives	186	This sets the default read callback, which is called when data arrives
105	and no read request is in the queue.	187	and no read request is in the queue (unlike read queue callbacks, this
		188	callback will only be called when at least one octet of data is in the
		189	read buffer).
106		190
107	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	191	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108	method or access the C<$self->{rbuf}> member directly.	192	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		193	must not enlarge or modify the read buffer, you can only remove data at
		194	the beginning from it.
109		195
		196	You can also call C<< ->push_read (...) >> or any other function that
		197	modifies the read queue. Or do both. Or ...
		198
110	When an EOF condition is detected then AnyEvent::Handle will first try to	199	When an EOF condition is detected, AnyEvent::Handle will first try to
111	feed all the remaining data to the queued callbacks and C<on_read> before	200	feed all the remaining data to the queued callbacks and C<on_read> before
112	calling the C<on_eof> callback. If no progress can be made, then a fatal	201	calling the C<on_eof> callback. If no progress can be made, then a fatal
113	error will be raised (with C<$!> set to C<EPIPE>).	202	error will be raised (with C<$!> set to C<EPIPE>).
114		203
		204	Note that, unlike requests in the read queue, an C<on_read> callback
		205	doesn't mean you I<require> some data: if there is an EOF and there
		206	are outstanding read requests then an error will be flagged. With an
		207	C<on_read> callback, the C<on_eof> callback will be invoked.
		208
		209	=item on_eof => $cb->($handle)
		210
		211	Set the callback to be called when an end-of-file condition is detected,
		212	i.e. in the case of a socket, when the other side has closed the
		213	connection cleanly, and there are no outstanding read requests in the
		214	queue (if there are read requests, then an EOF counts as an unexpected
		215	connection close and will be flagged as an error).
		216
		217	For sockets, this just means that the other side has stopped sending data,
		218	you can still try to write data, and, in fact, one can return from the EOF
		219	callback and continue writing data, as only the read part has been shut
		220	down.
		221
		222	If an EOF condition has been detected but no C<on_eof> callback has been
		223	set, then a fatal error will be raised with C<$!> set to <0>.
		224
115	=item on_drain => $cb->()	225	=item on_drain => $cb->($handle)
116		226
117	This sets the callback that is called when the write buffer becomes empty	227	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).	228	(or immediately if the buffer is empty already).
119		229
120	To append to the write buffer, use the C<< ->push_write >> method.	230	To append to the write buffer, use the C<< ->push_write >> method.
		231
		232	This callback is useful when you don't want to put all of your write data
		233	into the queue at once, for example, when you want to write the contents
		234	of some file to the socket you might not want to read the whole file into
		235	memory and push it into the queue, but instead only read more data from
		236	the file when the write queue becomes empty.
		237
		238	=item timeout => $fractional_seconds
		239
		240	=item rtimeout => $fractional_seconds
		241
		242	=item wtimeout => $fractional_seconds
		243
		244	If non-zero, then these enables an "inactivity" timeout: whenever this
		245	many seconds pass without a successful read or write on the underlying
		246	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		247	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		248	error will be raised).
		249
		250	There are three variants of the timeouts that work independently
		251	of each other, for both read and write, just read, and just write:
		252	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		253	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		254	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		255
		256	Note that timeout processing is active even when you do not have
		257	any outstanding read or write requests: If you plan to keep the connection
		258	idle then you should disable the timeout temporarily or ignore the timeout
		259	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		260	restart the timeout.
		261
		262	Zero (the default) disables this timeout.
		263
		264	=item on_timeout => $cb->($handle)
		265
		266	Called whenever the inactivity timeout passes. If you return from this
		267	callback, then the timeout will be reset as if some activity had happened,
		268	so this condition is not fatal in any way.
121		269
122	=item rbuf_max => <bytes>	270	=item rbuf_max => <bytes>
123		271
124	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	272	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125	when the read buffer ever (strictly) exceeds this size. This is useful to	273	when the read buffer ever (strictly) exceeds this size. This is useful to
126	avoid denial-of-service attacks.	274	avoid some forms of denial-of-service attacks.
127		275
128	For example, a server accepting connections from untrusted sources should	276	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	277	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	278	(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	279	amount of data without a callback ever being called as long as the line
132	isn't finished).	280	isn't finished).
133		281
		282	=item autocork => <boolean>
		283
		284	When disabled (the default), C<push_write> will try to immediately
		285	write the data to the handle if possible. This avoids having to register
		286	a write watcher and wait for the next event loop iteration, but can
		287	be inefficient if you write multiple small chunks (on the wire, this
		288	disadvantage is usually avoided by your kernel's nagle algorithm, see
		289	C<no_delay>, but this option can save costly syscalls).
		290
		291	When enabled, writes will always be queued till the next event loop
		292	iteration. This is efficient when you do many small writes per iteration,
		293	but less efficient when you do a single write only per iteration (or when
		294	the write buffer often is full). It also increases write latency.
		295
		296	=item no_delay => <boolean>
		297
		298	When doing small writes on sockets, your operating system kernel might
		299	wait a bit for more data before actually sending it out. This is called
		300	the Nagle algorithm, and usually it is beneficial.
		301
		302	In some situations you want as low a delay as possible, which can be
		303	accomplishd by setting this option to a true value.
		304
		305	The default is your operating system's default behaviour (most likely
		306	enabled). This option explicitly enables or disables it, if possible.
		307
		308	=item keepalive => <boolean>
		309
		310	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		311	normally, TCP connections have no time-out once established, so TCP
		312	connections, once established, can stay alive forever even when the other
		313	side has long gone. TCP keepalives are a cheap way to take down long-lived
		314	TCP connections when the other side becomes unreachable. While the default
		315	is OS-dependent, TCP keepalives usually kick in after around two hours,
		316	and, if the other side doesn't reply, take down the TCP connection some 10
		317	to 15 minutes later.
		318
		319	It is harmless to specify this option for file handles that do not support
		320	keepalives, and enabling it on connections that are potentially long-lived
		321	is usually a good idea.
		322
		323	=item oobinline => <boolean>
		324
		325	BSD majorly fucked up the implementation of TCP urgent data. The result
		326	is that almost no OS implements TCP according to the specs, and every OS
		327	implements it slightly differently.
		328
		329	If you want to handle TCP urgent data, then setting this flag (the default
		330	is enabled) gives you the most portable way of getting urgent data, by
		331	putting it into the stream.
		332
		333	Since BSD emulation of OOB data on top of TCP's urgent data can have
		334	security implications, AnyEvent::Handle sets this flag automatically
		335	unless explicitly specified. Note that setting this flag after
		336	establishing a connection I<may> be a bit too late (data loss could
		337	already have occured on BSD systems), but at least it will protect you
		338	from most attacks.
		339
134	=item read_size => <bytes>	340	=item read_size => <bytes>
135		341
136	The default read block size (the amount of bytes this module will try to read	342	The default read block size (the number of bytes this module will
137	on each [loop iteration). Default: C<4096>.	343	try to read during each loop iteration, which affects memory
		344	requirements). Default: C<8192>.
138		345
139	=item low_water_mark => <bytes>	346	=item low_water_mark => <bytes>
140		347
141	Sets the amount of bytes (default: C<0>) that make up an "empty" write	348	Sets the number of bytes (default: C<0>) that make up an "empty" write
142	buffer: If the write reaches this size or gets even samller it is	349	buffer: If the buffer reaches this size or gets even samller it is
143	considered empty.	350	considered empty.
144		351
		352	Sometimes it can be beneficial (for performance reasons) to add data to
		353	the write buffer before it is fully drained, but this is a rare case, as
		354	the operating system kernel usually buffers data as well, so the default
		355	is good in almost all cases.
		356
		357	=item linger => <seconds>
		358
		359	If this is non-zero (default: C<3600>), the destructor of the
		360	AnyEvent::Handle object will check whether there is still outstanding
		361	write data and will install a watcher that will write this data to the
		362	socket. No errors will be reported (this mostly matches how the operating
		363	system treats outstanding data at socket close time).
		364
		365	This will not work for partial TLS data that could not be encoded
		366	yet. This data will be lost. Calling the C<stoptls> method in time might
		367	help.
		368
		369	=item peername => $string
		370
		371	A string used to identify the remote site - usually the DNS hostname
		372	(I<not> IDN!) used to create the connection, rarely the IP address.
		373
		374	Apart from being useful in error messages, this string is also used in TLS
		375	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		376	verification will be skipped when C<peername> is not specified or is
		377	C<undef>.
		378
145	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	379	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146		380
147	When this parameter is given, it enables TLS (SSL) mode, that means it	381	When this parameter is given, it enables TLS (SSL) mode, that means
148	will start making tls handshake and will transparently encrypt/decrypt	382	AnyEvent will start a TLS handshake as soon as the connection has been
149	data.	383	established and will transparently encrypt/decrypt data afterwards.
		384
		385	All TLS protocol errors will be signalled as C<EPROTO>, with an
		386	appropriate error message.
150		387
151	TLS mode requires Net::SSLeay to be installed (it will be loaded	388	TLS mode requires Net::SSLeay to be installed (it will be loaded
152	automatically when you try to create a TLS handle).	389	automatically when you try to create a TLS handle): this module doesn't
		390	have a dependency on that module, so if your module requires it, you have
		391	to add the dependency yourself.
153		392
154	For the TLS server side, use C<accept>, and for the TLS client side of a	393	Unlike TCP, TLS has a server and client side: for the TLS server side, use
155	connection, use C<connect> mode.	394	C<accept>, and for the TLS client side of a connection, use C<connect>
		395	mode.
156		396
157	You can also provide your own TLS connection object, but you have	397	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>	398	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	399	or C<Net::SSLeay::set_accept_state> on it before you pass it to
160	AnyEvent::Handle.	400	AnyEvent::Handle. Also, this module will take ownership of this connection
		401	object.
161		402
		403	At some future point, AnyEvent::Handle might switch to another TLS
		404	implementation, then the option to use your own session object will go
		405	away.
		406
		407	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		408	passing in the wrong integer will lead to certain crash. This most often
		409	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		410	segmentation fault.
		411
162	See the C<starttls> method if you need to start TLs negotiation later.	412	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
163		413
164	=item tls_ctx => $ssl_ctx	414	=item tls_ctx => $anyevent_tls
165		415
166	Use the given Net::SSLeay::CTX object to create the new TLS connection	416	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	417	(unless a connection object was specified directly). If this parameter is
168	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	418	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169		419
		420	Instead of an object, you can also specify a hash reference with C<< key
		421	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		422	new TLS context object.
		423
		424	=item on_starttls => $cb->($handle, $success[, $error_message])
		425
		426	This callback will be invoked when the TLS/SSL handshake has finished. If
		427	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		428	(C<on_stoptls> will not be called in this case).
		429
		430	The session in C<< $handle->{tls} >> can still be examined in this
		431	callback, even when the handshake was not successful.
		432
		433	TLS handshake failures will not cause C<on_error> to be invoked when this
		434	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		435
		436	Without this callback, handshake failures lead to C<on_error> being
		437	called as usual.
		438
		439	Note that you cannot just call C<starttls> again in this callback. If you
		440	need to do that, start an zero-second timer instead whose callback can
		441	then call C<< ->starttls >> again.
		442
		443	=item on_stoptls => $cb->($handle)
		444
		445	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		446	set, then it will be invoked after freeing the TLS session. If it is not,
		447	then a TLS shutdown condition will be treated like a normal EOF condition
		448	on the handle.
		449
		450	The session in C<< $handle->{tls} >> can still be examined in this
		451	callback.
		452
		453	This callback will only be called on TLS shutdowns, not when the
		454	underlying handle signals EOF.
		455
		456	=item json => JSON or JSON::XS object
		457
		458	This is the json coder object used by the C<json> read and write types.
		459
		460	If you don't supply it, then AnyEvent::Handle will create and use a
		461	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		462	texts.
		463
		464	Note that you are responsible to depend on the JSON module if you want to
		465	use this functionality, as AnyEvent does not have a dependency itself.
		466
170	=back	467	=back
171		468
172	=cut	469	=cut
173		470
174	sub new {	471	sub new {
175	my $class = shift;	472	my $class = shift;
176
177	my $self = bless { @_ }, $class;	473	my $self = bless { @_ }, $class;
178		474
179	$self->{fh} or Carp::croak "mandatory argument fh is missing";	475	if ($self->{fh}) {
		476	$self->_start;
		477	return unless $self->{fh}; # could be gone by now
		478
		479	} elsif ($self->{connect}) {
		480	require AnyEvent::Socket;
		481
		482	$self->{peername} = $self->{connect}[0]
		483	unless exists $self->{peername};
		484
		485	$self->{_skip_drain_rbuf} = 1;
		486
		487	{
		488	Scalar::Util::weaken (my $self = $self);
		489
		490	$self->{_connect} =
		491	AnyEvent::Socket::tcp_connect (
		492	$self->{connect}[0],
		493	$self->{connect}[1],
		494	sub {
		495	my ($fh, $host, $port, $retry) = @_;
		496
		497	if ($fh) {
		498	$self->{fh} = $fh;
		499
		500	delete $self->{_skip_drain_rbuf};
		501	$self->_start;
		502
		503	$self->{on_connect}
		504	and $self->{on_connect}($self, $host, $port, sub {
		505	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		506	$self->{_skip_drain_rbuf} = 1;
		507	&$retry;
		508	});
		509
		510	} else {
		511	if ($self->{on_connect_error}) {
		512	$self->{on_connect_error}($self, "$!");
		513	$self->destroy;
		514	} else {
		515	$self->_error ($!, 1);
		516	}
		517	}
		518	},
		519	sub {
		520	local $self->{fh} = $_[0];
		521
		522	$self->{on_prepare}
		523	? $self->{on_prepare}->($self)
		524	: ()
		525	}
		526	);
		527	}
		528
		529	} else {
		530	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		531	}
		532
		533	$self
		534	}
		535
		536	sub _start {
		537	my ($self) = @_;
		538
		539	# too many clueless people try to use udp and similar sockets
		540	# with AnyEvent::Handle, do them a favour.
		541	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		542	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		543	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
180		544
181	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	545	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182		546
183	if ($self->{tls}) {	547	$self->{_activity} =
184	require Net::SSLeay;	548	$self->{_ractivity} =
		549	$self->{_wactivity} = AE::now;
		550
		551	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		552	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		553	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		554
		555	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		556	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		557
		558	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		559
185	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	560	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186	}	561	if $self->{tls};
187		562
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};	563	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
191	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
192		564
193	$self->start_read;	565	$self->start_read
		566	if $self->{on_read} || @{ $self->{_queue} };
194		567
195	$self	568	$self->_drain_wbuf;
196	}	569	}
197		570
198	sub _shutdown {
199	my ($self) = @_;
200
201	delete $self->{rw};
202	delete $self->{ww};
203	delete $self->{fh};
204	}
205
206	sub error {	571	sub _error {
207	my ($self) = @_;	572	my ($self, $errno, $fatal, $message) = @_;
208		573
209	{	574	$! = $errno;
210	local $!;	575	$message ||= "$!";
211	$self->_shutdown;
212	}
213		576
214	if ($self->{on_error}) {	577	if ($self->{on_error}) {
215	$self->{on_error}($self);	578	$self->{on_error}($self, $fatal, $message);
216	} else {	579	$self->destroy if $fatal;
		580	} elsif ($self->{fh} || $self->{connect}) {
		581	$self->destroy;
217	Carp::croak "AnyEvent::Handle uncaught fatal error: $!";	582	Carp::croak "AnyEvent::Handle uncaught error: $message";
218	}	583	}
219	}	584	}
220		585
221	=item $fh = $handle->fh	586	=item $fh = $handle->fh
222		587
223	This method returns the file handle of the L<AnyEvent::Handle> object.	588	This method returns the file handle used to create the L<AnyEvent::Handle> object.
224		589
225	=cut	590	=cut
226		591
227	sub fh { $_[0]->{fh} }	592	sub fh { $_[0]{fh} }
228		593
229	=item $handle->on_error ($cb)	594	=item $handle->on_error ($cb)
230		595
231	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	596	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232		597
…		…
244		609
245	sub on_eof {	610	sub on_eof {
246	$_[0]{on_eof} = $_[1];	611	$_[0]{on_eof} = $_[1];
247	}	612	}
248		613
		614	=item $handle->on_timeout ($cb)
		615
		616	=item $handle->on_rtimeout ($cb)
		617
		618	=item $handle->on_wtimeout ($cb)
		619
		620	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		621	callback, or disables the callback (but not the timeout) if C<$cb> =
		622	C<undef>. See the C<timeout> constructor argument and method.
		623
		624	=cut
		625
		626	# see below
		627
		628	=item $handle->autocork ($boolean)
		629
		630	Enables or disables the current autocork behaviour (see C<autocork>
		631	constructor argument). Changes will only take effect on the next write.
		632
		633	=cut
		634
		635	sub autocork {
		636	$_[0]{autocork} = $_[1];
		637	}
		638
		639	=item $handle->no_delay ($boolean)
		640
		641	Enables or disables the C<no_delay> setting (see constructor argument of
		642	the same name for details).
		643
		644	=cut
		645
		646	sub no_delay {
		647	$_[0]{no_delay} = $_[1];
		648
		649	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		650	if $_[0]{fh};
		651	}
		652
		653	=item $handle->keepalive ($boolean)
		654
		655	Enables or disables the C<keepalive> setting (see constructor argument of
		656	the same name for details).
		657
		658	=cut
		659
		660	sub keepalive {
		661	$_[0]{keepalive} = $_[1];
		662
		663	eval {
		664	local $SIG{__DIE__};
		665	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		666	if $_[0]{fh};
		667	};
		668	}
		669
		670	=item $handle->oobinline ($boolean)
		671
		672	Enables or disables the C<oobinline> setting (see constructor argument of
		673	the same name for details).
		674
		675	=cut
		676
		677	sub oobinline {
		678	$_[0]{oobinline} = $_[1];
		679
		680	eval {
		681	local $SIG{__DIE__};
		682	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		683	if $_[0]{fh};
		684	};
		685	}
		686
		687	=item $handle->keepalive ($boolean)
		688
		689	Enables or disables the C<keepalive> setting (see constructor argument of
		690	the same name for details).
		691
		692	=cut
		693
		694	sub keepalive {
		695	$_[0]{keepalive} = $_[1];
		696
		697	eval {
		698	local $SIG{__DIE__};
		699	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		700	if $_[0]{fh};
		701	};
		702	}
		703
		704	=item $handle->on_starttls ($cb)
		705
		706	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		707
		708	=cut
		709
		710	sub on_starttls {
		711	$_[0]{on_starttls} = $_[1];
		712	}
		713
		714	=item $handle->on_stoptls ($cb)
		715
		716	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		717
		718	=cut
		719
		720	sub on_stoptls {
		721	$_[0]{on_stoptls} = $_[1];
		722	}
		723
		724	=item $handle->rbuf_max ($max_octets)
		725
		726	Configures the C<rbuf_max> setting (C<undef> disables it).
		727
		728	=cut
		729
		730	sub rbuf_max {
		731	$_[0]{rbuf_max} = $_[1];
		732	}
		733
		734	#############################################################################
		735
		736	=item $handle->timeout ($seconds)
		737
		738	=item $handle->rtimeout ($seconds)
		739
		740	=item $handle->wtimeout ($seconds)
		741
		742	Configures (or disables) the inactivity timeout.
		743
		744	=item $handle->timeout_reset
		745
		746	=item $handle->rtimeout_reset
		747
		748	=item $handle->wtimeout_reset
		749
		750	Reset the activity timeout, as if data was received or sent.
		751
		752	These methods are cheap to call.
		753
		754	=cut
		755
		756	for my $dir ("", "r", "w") {
		757	my $timeout = "${dir}timeout";
		758	my $tw = "_${dir}tw";
		759	my $on_timeout = "on_${dir}timeout";
		760	my $activity = "_${dir}activity";
		761	my $cb;
		762
		763	*$on_timeout = sub {
		764	$_[0]{$on_timeout} = $_[1];
		765	};
		766
		767	*$timeout = sub {
		768	my ($self, $new_value) = @_;
		769
		770	$self->{$timeout} = $new_value;
		771	delete $self->{$tw}; &$cb;
		772	};
		773
		774	*{"${dir}timeout_reset"} = sub {
		775	$_[0]{$activity} = AE::now;
		776	};
		777
		778	# main workhorse:
		779	# reset the timeout watcher, as neccessary
		780	# also check for time-outs
		781	$cb = sub {
		782	my ($self) = @_;
		783
		784	if ($self->{$timeout} && $self->{fh}) {
		785	my $NOW = AE::now;
		786
		787	# when would the timeout trigger?
		788	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		789
		790	# now or in the past already?
		791	if ($after <= 0) {
		792	$self->{$activity} = $NOW;
		793
		794	if ($self->{$on_timeout}) {
		795	$self->{$on_timeout}($self);
		796	} else {
		797	$self->_error (Errno::ETIMEDOUT);
		798	}
		799
		800	# callback could have changed timeout value, optimise
		801	return unless $self->{$timeout};
		802
		803	# calculate new after
		804	$after = $self->{$timeout};
		805	}
		806
		807	Scalar::Util::weaken $self;
		808	return unless $self; # ->error could have destroyed $self
		809
		810	$self->{$tw} ||= AE::timer $after, 0, sub {
		811	delete $self->{$tw};
		812	$cb->($self);
		813	};
		814	} else {
		815	delete $self->{$tw};
		816	}
		817	}
		818	}
		819
249	#############################################################################	820	#############################################################################
250		821
251	=back	822	=back
252		823
253	=head2 WRITE QUEUE	824	=head2 WRITE QUEUE
…		…
266	=item $handle->on_drain ($cb)	837	=item $handle->on_drain ($cb)
267		838
268	Sets the C<on_drain> callback or clears it (see the description of	839	Sets the C<on_drain> callback or clears it (see the description of
269	C<on_drain> in the constructor).	840	C<on_drain> in the constructor).
270		841
		842	This method may invoke callbacks (and therefore the handle might be
		843	destroyed after it returns).
		844
271	=cut	845	=cut
272		846
273	sub on_drain {	847	sub on_drain {
274	my ($self, $cb) = @_;	848	my ($self, $cb) = @_;
275		849
276	$self->{on_drain} = $cb;	850	$self->{on_drain} = $cb;
277		851
278	$cb->($self)	852	$cb->($self)
279	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	853	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280	}	854	}
281		855
282	=item $handle->push_write ($data)	856	=item $handle->push_write ($data)
283		857
284	Queues the given scalar to be written. You can push as much data as you	858	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>	859	want (only limited by the available memory), as C<AnyEvent::Handle>
286	buffers it independently of the kernel.	860	buffers it independently of the kernel.
287		861
		862	This method may invoke callbacks (and therefore the handle might be
		863	destroyed after it returns).
		864
288	=cut	865	=cut
289		866
290	sub _drain_wbuf {	867	sub _drain_wbuf {
291	my ($self) = @_;	868	my ($self) = @_;
292		869
293	if (!$self->{ww} && length $self->{wbuf}) {	870	if (!$self->{_ww} && length $self->{wbuf}) {
		871
294	Scalar::Util::weaken $self;	872	Scalar::Util::weaken $self;
		873
295	my $cb = sub {	874	my $cb = sub {
296	my $len = syswrite $self->{fh}, $self->{wbuf};	875	my $len = syswrite $self->{fh}, $self->{wbuf};
297		876
298	if ($len >= 0) {	877	if (defined $len) {
299	substr $self->{wbuf}, 0, $len, "";	878	substr $self->{wbuf}, 0, $len, "";
300		879
		880	$self->{_activity} = $self->{_wactivity} = AE::now;
		881
301	$self->{on_drain}($self)	882	$self->{on_drain}($self)
302	if $self->{low_water_mark} >= length $self->{wbuf}	883	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303	&& $self->{on_drain};	884	&& $self->{on_drain};
304		885
305	delete $self->{ww} unless length $self->{wbuf};	886	delete $self->{_ww} unless length $self->{wbuf};
306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAWOULDBLOCK) {	887	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307	$self->error;	888	$self->_error ($!, 1);
308	}	889	}
309	};	890	};
310		891
311	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	892	# try to write data immediately
		893	$cb->() unless $self->{autocork};
312		894
313	$cb->($self);	895	# if still data left in wbuf, we need to poll
		896	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		897	if length $self->{wbuf};
314	};	898	};
315	}	899	}
316		900
317	our %WH;	901	our %WH;
318		902
		903	# deprecated
319	sub register_write_type($$) {	904	sub register_write_type($$) {
320	$WH{$_[0]} = $_[1];	905	$WH{$_[0]} = $_[1];
321	}	906	}
322		907
323	sub push_write {	908	sub push_write {
324	my $self = shift;	909	my $self = shift;
325		910
326	if (@_ > 1) {	911	if (@_ > 1) {
327	my $type = shift;	912	my $type = shift;
328		913
		914	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
329	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	915	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
330	->($self, @_);	916	->($self, @_);
331	}	917	}
332		918
		919	# we downgrade here to avoid hard-to-track-down bugs,
		920	# and diagnose the problem earlier and better.
		921
333	if ($self->{filter_w}) {	922	if ($self->{tls}) {
334	$self->{filter_w}->($self, \$_[0]);	923	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		924	&_dotls ($self) if $self->{fh};
335	} else {	925	} else {
336	$self->{wbuf} .= $_[0];	926	utf8::downgrade $self->{wbuf} .= $_[0];
337	$self->_drain_wbuf;	927	$self->_drain_wbuf if $self->{fh};
338	}	928	}
339	}	929	}
340		930
341	=item $handle->push_write (type => @args)	931	=item $handle->push_write (type => @args)
342		932
343	=item $handle->unshift_write (type => @args)
344
345	Instead of formatting your data yourself, you can also let this module do	933	Instead of formatting your data yourself, you can also let this module
346	the job by specifying a type and type-specific arguments.	934	do the job by specifying a type and type-specific arguments. You
		935	can also specify the (fully qualified) name of a package, in which
		936	case AnyEvent tries to load the package and then expects to find the
		937	C<anyevent_write_type> function inside (see "custom write types", below).
347		938
348	Predefined types are (if you have ideas for additional types, feel free to	939	Predefined types are (if you have ideas for additional types, feel free to
349	drop by and tell us):	940	drop by and tell us):
350		941
351	=over 4	942	=over 4
…		…
353	=item netstring => $string	944	=item netstring => $string
354		945
355	Formats the given value as netstring	946	Formats the given value as netstring
356	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).	947	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357		948
358	=back
359
360	=cut	949	=cut
361		950
362	register_write_type netstring => sub {	951	register_write_type netstring => sub {
363	my ($self, $string) = @_;	952	my ($self, $string) = @_;
364		953
365	sprintf "%d:%s,", (length $string), $string	954	(length $string) . ":$string,"
366	};	955	};
367		956
368	=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args)	957	=item packstring => $format, $data
369		958
370	This function (not method) lets you add your own types to C<push_write>.	959	An octet string prefixed with an encoded length. The encoding C<$format>
		960	uses the same format as a Perl C<pack> format, but must specify a single
		961	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		962	optional C<!>, C<< < >> or C<< > >> modifier).
		963
		964	=cut
		965
		966	register_write_type packstring => sub {
		967	my ($self, $format, $string) = @_;
		968
		969	pack "$format/a*", $string
		970	};
		971
		972	=item json => $array_or_hashref
		973
		974	Encodes the given hash or array reference into a JSON object. Unless you
		975	provide your own JSON object, this means it will be encoded to JSON text
		976	in UTF-8.
		977
		978	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		979	one end of a handle and read them at the other end without using any
		980	additional framing.
		981
		982	The generated JSON text is guaranteed not to contain any newlines: While
		983	this module doesn't need delimiters after or between JSON texts to be
		984	able to read them, many other languages depend on that.
		985
		986	A simple RPC protocol that interoperates easily with others is to send
		987	JSON arrays (or objects, although arrays are usually the better choice as
		988	they mimic how function argument passing works) and a newline after each
		989	JSON text:
		990
		991	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		992	$handle->push_write ("\012");
		993
		994	An AnyEvent::Handle receiver would simply use the C<json> read type and
		995	rely on the fact that the newline will be skipped as leading whitespace:
		996
		997	$handle->push_read (json => sub { my $array = $_[1]; ... });
		998
		999	Other languages could read single lines terminated by a newline and pass
		1000	this line into their JSON decoder of choice.
		1001
		1002	=cut
		1003
		1004	sub json_coder() {
		1005	eval { require JSON::XS; JSON::XS->new->utf8 }
		1006	|| do { require JSON; JSON->new->utf8 }
		1007	}
		1008
		1009	register_write_type json => sub {
		1010	my ($self, $ref) = @_;
		1011
		1012	my $json = $self->{json} ||= json_coder;
		1013
		1014	$json->encode ($ref)
		1015	};
		1016
		1017	=item storable => $reference
		1018
		1019	Freezes the given reference using L<Storable> and writes it to the
		1020	handle. Uses the C<nfreeze> format.
		1021
		1022	=cut
		1023
		1024	register_write_type storable => sub {
		1025	my ($self, $ref) = @_;
		1026
		1027	require Storable;
		1028
		1029	pack "w/a*", Storable::nfreeze ($ref)
		1030	};
		1031
		1032	=back
		1033
		1034	=item $handle->push_shutdown
		1035
		1036	Sometimes you know you want to close the socket after writing your data
		1037	before it was actually written. One way to do that is to replace your
		1038	C<on_drain> handler by a callback that shuts down the socket (and set
		1039	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1040	replaces the C<on_drain> callback with:
		1041
		1042	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1043
		1044	This simply shuts down the write side and signals an EOF condition to the
		1045	the peer.
		1046
		1047	You can rely on the normal read queue and C<on_eof> handling
		1048	afterwards. This is the cleanest way to close a connection.
		1049
		1050	This method may invoke callbacks (and therefore the handle might be
		1051	destroyed after it returns).
		1052
		1053	=cut
		1054
		1055	sub push_shutdown {
		1056	my ($self) = @_;
		1057
		1058	delete $self->{low_water_mark};
		1059	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1060	}
		1061
		1062	=item custom write types - Package::anyevent_write_type $handle, @args
		1063
		1064	Instead of one of the predefined types, you can also specify the name of
		1065	a package. AnyEvent will try to load the package and then expects to find
		1066	a function named C<anyevent_write_type> inside. If it isn't found, it
		1067	progressively tries to load the parent package until it either finds the
		1068	function (good) or runs out of packages (bad).
		1069
371	Whenever the given C<type> is used, C<push_write> will invoke the code	1070	Whenever the given C<type> is used, C<push_write> will the function with
372	reference with the handle object and the remaining arguments.	1071	the handle object and the remaining arguments.
373		1072
374	The code reference is supposed to return a single octet string that will	1073	The function is supposed to return a single octet string that will be
375	be appended to the write buffer.	1074	appended to the write buffer, so you cna mentally treat this function as a
		1075	"arguments to on-the-wire-format" converter.
376		1076
377	Note that this is a function, and all types registered this way will be	1077	Example: implement a custom write type C<join> that joins the remaining
378	global, so try to use unique names.	1078	arguments using the first one.
		1079
		1080	$handle->push_write (My::Type => " ", 1,2,3);
		1081
		1082	# uses the following package, which can be defined in the "My::Type" or in
		1083	# the "My" modules to be auto-loaded, or just about anywhere when the
		1084	# My::Type::anyevent_write_type is defined before invoking it.
		1085
		1086	package My::Type;
		1087
		1088	sub anyevent_write_type {
		1089	my ($handle, $delim, @args) = @_;
		1090
		1091	join $delim, @args
		1092	}
379		1093
380	=cut	1094	=cut
381		1095
382	#############################################################################	1096	#############################################################################
383		1097
…		…
392	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1106	ways, the "simple" way, using only C<on_read> and the "complex" way, using
393	a queue.	1107	a queue.
394		1108
395	In the simple case, you just install an C<on_read> callback and whenever	1109	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	1110	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	1111	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
398	or not.	1112	leave the data there if you want to accumulate more (e.g. when only a
		1113	partial message has been received so far), or change the read queue with
		1114	e.g. C<push_read>.
399		1115
400	In the more complex case, you want to queue multiple callbacks. In this	1116	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	1117	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>,	1118	data arrives (also the first time it is queued) and remove it when it has
403	below).	1119	done its job (see C<push_read>, below).
404		1120
405	This way you can, for example, push three line-reads, followed by reading	1121	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.	1122	a chunk of data, and AnyEvent::Handle will execute them in order.
407		1123
408	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1124	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409	the specified number of bytes which give an XML datagram.	1125	the specified number of bytes which give an XML datagram.
410		1126
411	# in the default state, expect some header bytes	1127	# in the default state, expect some header bytes
412	$handle->on_read (sub {	1128	$handle->on_read (sub {
413	# some data is here, now queue the length-header-read (4 octets)	1129	# some data is here, now queue the length-header-read (4 octets)
414	shift->unshift_read_chunk (4, sub {	1130	shift->unshift_read (chunk => 4, sub {
415	# header arrived, decode	1131	# header arrived, decode
416	my $len = unpack "N", $_[1];	1132	my $len = unpack "N", $_[1];
417		1133
418	# now read the payload	1134	# now read the payload
419	shift->unshift_read_chunk ($len, sub {	1135	shift->unshift_read (chunk => $len, sub {
420	my $xml = $_[1];	1136	my $xml = $_[1];
421	# handle xml	1137	# handle xml
422	});	1138	});
423	});	1139	});
424	});	1140	});
425		1141
426	Example 2: Implement a client for a protocol that replies either with	1142	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	1143	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	1144	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	1145	just pipeline sending both requests and manipulate the queue as necessary
430	the callbacks:	1146	in the callbacks.
431		1147
432	# request one	1148	When the first callback is called and sees an "OK" response, it will
		1149	C<unshift> another line-read. This line-read will be queued I<before> the
		1150	64-byte chunk callback.
		1151
		1152	# request one, returns either "OK + extra line" or "ERROR"
433	$handle->push_write ("request 1\015\012");	1153	$handle->push_write ("request 1\015\012");
434		1154
435	# we expect "ERROR" or "OK" as response, so push a line read	1155	# we expect "ERROR" or "OK" as response, so push a line read
436	$handle->push_read_line (sub {	1156	$handle->push_read (line => sub {
437	# if we got an "OK", we have to _prepend_ another line,	1157	# if we got an "OK", we have to _prepend_ another line,
438	# so it will be read before the second request reads its 64 bytes	1158	# so it will be read before the second request reads its 64 bytes
439	# which are already in the queue when this callback is called	1159	# which are already in the queue when this callback is called
440	# we don't do this in case we got an error	1160	# we don't do this in case we got an error
441	if ($_[1] eq "OK") {	1161	if ($_[1] eq "OK") {
442	$_[0]->unshift_read_line (sub {	1162	$_[0]->unshift_read (line => sub {
443	my $response = $_[1];	1163	my $response = $_[1];
444	...	1164	...
445	});	1165	});
446	}	1166	}
447	});	1167	});
448		1168
449	# request two	1169	# request two, simply returns 64 octets
450	$handle->push_write ("request 2\015\012");	1170	$handle->push_write ("request 2\015\012");
451		1171
452	# simply read 64 bytes, always	1172	# simply read 64 bytes, always
453	$handle->push_read_chunk (64, sub {	1173	$handle->push_read (chunk => 64, sub {
454	my $response = $_[1];	1174	my $response = $_[1];
455	...	1175	...
456	});	1176	});
457		1177
458	=over 4	1178	=over 4
459		1179
460	=cut	1180	=cut
461		1181
462	sub _drain_rbuf {	1182	sub _drain_rbuf {
463	my ($self) = @_;	1183	my ($self) = @_;
		1184
		1185	# avoid recursion
		1186	return if $self->{_skip_drain_rbuf};
		1187	local $self->{_skip_drain_rbuf} = 1;
		1188
		1189	while () {
		1190	# we need to use a separate tls read buffer, as we must not receive data while
		1191	# we are draining the buffer, and this can only happen with TLS.
		1192	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1193	if exists $self->{_tls_rbuf};
		1194
		1195	my $len = length $self->{rbuf};
		1196
		1197	if (my $cb = shift @{ $self->{_queue} }) {
		1198	unless ($cb->($self)) {
		1199	# no progress can be made
		1200	# (not enough data and no data forthcoming)
		1201	$self->_error (Errno::EPIPE, 1), return
		1202	if $self->{_eof};
		1203
		1204	unshift @{ $self->{_queue} }, $cb;
		1205	last;
		1206	}
		1207	} elsif ($self->{on_read}) {
		1208	last unless $len;
		1209
		1210	$self->{on_read}($self);
		1211
		1212	if (
		1213	$len == length $self->{rbuf} # if no data has been consumed
		1214	&& !@{ $self->{_queue} } # and the queue is still empty
		1215	&& $self->{on_read} # but we still have on_read
		1216	) {
		1217	# no further data will arrive
		1218	# so no progress can be made
		1219	$self->_error (Errno::EPIPE, 1), return
		1220	if $self->{_eof};
		1221
		1222	last; # more data might arrive
		1223	}
		1224	} else {
		1225	# read side becomes idle
		1226	delete $self->{_rw} unless $self->{tls};
		1227	last;
		1228	}
		1229	}
		1230
		1231	if ($self->{_eof}) {
		1232	$self->{on_eof}
		1233	? $self->{on_eof}($self)
		1234	: $self->_error (0, 1, "Unexpected end-of-file");
		1235
		1236	return;
		1237	}
464		1238
465	if (	1239	if (
466	defined $self->{rbuf_max}	1240	defined $self->{rbuf_max}
467	&& $self->{rbuf_max} < length $self->{rbuf}	1241	&& $self->{rbuf_max} < length $self->{rbuf}
468	) {	1242	) {
469	$! = &Errno::ENOSPC; return $self->error;	1243	$self->_error (Errno::ENOSPC, 1), return;
470	}	1244	}
471		1245
472	return if $self->{in_drain};	1246	# may need to restart read watcher
473	local $self->{in_drain} = 1;	1247	unless ($self->{_rw}) {
474		1248	$self->start_read
475	while (my $len = length $self->{rbuf}) {	1249	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	}	1250	}
511	}	1251	}
512		1252
513	=item $handle->on_read ($cb)	1253	=item $handle->on_read ($cb)
514		1254
515	This replaces the currently set C<on_read> callback, or clears it (when	1255	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	1256	the new callback is C<undef>). See the description of C<on_read> in the
517	constructor.	1257	constructor.
518		1258
		1259	This method may invoke callbacks (and therefore the handle might be
		1260	destroyed after it returns).
		1261
519	=cut	1262	=cut
520		1263
521	sub on_read {	1264	sub on_read {
522	my ($self, $cb) = @_;	1265	my ($self, $cb) = @_;
523		1266
524	$self->{on_read} = $cb;	1267	$self->{on_read} = $cb;
		1268	$self->_drain_rbuf if $cb;
525	}	1269	}
526		1270
527	=item $handle->rbuf	1271	=item $handle->rbuf
528		1272
529	Returns the read buffer (as a modifiable lvalue).	1273	Returns the read buffer (as a modifiable lvalue). You can also access the
		1274	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1275	much faster, and no less clean).
530		1276
531	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1277	The only operation allowed on the read buffer (apart from looking at it)
532	you want.	1278	is removing data from its beginning. Otherwise modifying or appending to
		1279	it is not allowed and will lead to hard-to-track-down bugs.
533		1280
534	NOTE: The read buffer should only be used or modified if the C<on_read>,	1281	NOTE: The read buffer should only be used or modified in the C<on_read>
535	C<push_read> or C<unshift_read> methods are used. The other read methods	1282	callback or when C<push_read> or C<unshift_read> are used with a single
536	automatically manage the read buffer.	1283	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1284	will manage the read buffer on their own.
537		1285
538	=cut	1286	=cut
539		1287
540	sub rbuf : lvalue {	1288	sub rbuf : lvalue {
541	$_[0]{rbuf}	1289	$_[0]{rbuf}
…		…
558		1306
559	If enough data was available, then the callback must remove all data it is	1307	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	1308	interested in (which can be none at all) and return a true value. After returning
561	true, it will be removed from the queue.	1309	true, it will be removed from the queue.
562		1310
		1311	These methods may invoke callbacks (and therefore the handle might be
		1312	destroyed after it returns).
		1313
563	=cut	1314	=cut
564		1315
565	our %RH;	1316	our %RH;
566		1317
567	sub register_read_type($$) {	1318	sub register_read_type($$) {
…		…
573	my $cb = pop;	1324	my $cb = pop;
574		1325
575	if (@_) {	1326	if (@_) {
576	my $type = shift;	1327	my $type = shift;
577		1328
		1329	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
578	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1330	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
579	->($self, $cb, @_);	1331	->($self, $cb, @_);
580	}	1332	}
581		1333
582	push @{ $self->{queue} }, $cb;	1334	push @{ $self->{_queue} }, $cb;
583	$self->_drain_rbuf;	1335	$self->_drain_rbuf;
584	}	1336	}
585		1337
586	sub unshift_read {	1338	sub unshift_read {
587	my $self = shift;	1339	my $self = shift;
588	my $cb = pop;	1340	my $cb = pop;
589		1341
590	if (@_) {	1342	if (@_) {
591	my $type = shift;	1343	my $type = shift;
592		1344
		1345	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
593	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1346	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
594	->($self, $cb, @_);	1347	->($self, $cb, @_);
595	}	1348	}
596		1349
597
598	unshift @{ $self->{queue} }, $cb;	1350	unshift @{ $self->{_queue} }, $cb;
599	$self->_drain_rbuf;	1351	$self->_drain_rbuf;
600	}	1352	}
601		1353
602	=item $handle->push_read (type => @args, $cb)	1354	=item $handle->push_read (type => @args, $cb)
603		1355
604	=item $handle->unshift_read (type => @args, $cb)	1356	=item $handle->unshift_read (type => @args, $cb)
605		1357
606	Instead of providing a callback that parses the data itself you can chose	1358	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	1359	between a number of predefined parsing formats, for chunks of data, lines
608	etc.	1360	etc. You can also specify the (fully qualified) name of a package, in
		1361	which case AnyEvent tries to load the package and then expects to find the
		1362	C<anyevent_read_type> function inside (see "custom read types", below).
609		1363
610	Predefined types are (if you have ideas for additional types, feel free to	1364	Predefined types are (if you have ideas for additional types, feel free to
611	drop by and tell us):	1365	drop by and tell us):
612		1366
613	=over 4	1367	=over 4
614		1368
615	=item chunk => $octets, $cb->($self, $data)	1369	=item chunk => $octets, $cb->($handle, $data)
616		1370
617	Invoke the callback only once C<$octets> bytes have been read. Pass the	1371	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	1372	data read to the callback. The callback will never be called with less
619	data.	1373	data.
620		1374
…		…
634	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1388	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635	1	1389	1
636	}	1390	}
637	};	1391	};
638		1392
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, $eol)	1393	=item line => [$eol, ]$cb->($handle, $line, $eol)
649		1394
650	The callback will be called only once a full line (including the end of	1395	The callback will be called only once a full line (including the end of
651	line marker, C<$eol>) has been read. This line (excluding the end of line	1396	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	1397	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>).	1398	the end of line marker as the third argument (C<$eol>).
…		…
667	=cut	1412	=cut
668		1413
669	register_read_type line => sub {	1414	register_read_type line => sub {
670	my ($self, $cb, $eol) = @_;	1415	my ($self, $cb, $eol) = @_;
671		1416
672	$eol = qr|(\015?\012)| if @_ < 3;	1417	if (@_ < 3) {
		1418	# this is more than twice as fast as the generic code below
		1419	sub {
		1420	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1421
		1422	$cb->($_[0], $1, $2);
		1423	1
		1424	}
		1425	} else {
673	$eol = quotemeta $eol unless ref $eol;	1426	$eol = quotemeta $eol unless ref $eol;
674	$eol = qr|^(.*?)($eol)|s;	1427	$eol = qr|^(.*?)($eol)|s;
		1428
		1429	sub {
		1430	$_[0]{rbuf} =~ s/$eol// or return;
		1431
		1432	$cb->($_[0], $1, $2);
		1433	1
		1434	}
		1435	}
		1436	};
		1437
		1438	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1439
		1440	Makes a regex match against the regex object C<$accept> and returns
		1441	everything up to and including the match.
		1442
		1443	Example: read a single line terminated by '\n'.
		1444
		1445	$handle->push_read (regex => qr<\n>, sub { ... });
		1446
		1447	If C<$reject> is given and not undef, then it determines when the data is
		1448	to be rejected: it is matched against the data when the C<$accept> regex
		1449	does not match and generates an C<EBADMSG> error when it matches. This is
		1450	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1451	receive buffer overflow).
		1452
		1453	Example: expect a single decimal number followed by whitespace, reject
		1454	anything else (not the use of an anchor).
		1455
		1456	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1457
		1458	If C<$skip> is given and not C<undef>, then it will be matched against
		1459	the receive buffer when neither C<$accept> nor C<$reject> match,
		1460	and everything preceding and including the match will be accepted
		1461	unconditionally. This is useful to skip large amounts of data that you
		1462	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1463	have to start matching from the beginning. This is purely an optimisation
		1464	and is usually worth it only when you expect more than a few kilobytes.
		1465
		1466	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1467	expect the header to be very large (it isn't in practice, but...), we use
		1468	a skip regex to skip initial portions. The skip regex is tricky in that
		1469	it only accepts something not ending in either \015 or \012, as these are
		1470	required for the accept regex.
		1471
		1472	$handle->push_read (regex =>
		1473	qr<\015\012\015\012>,
		1474	undef, # no reject
		1475	qr<^.*[^\015\012]>,
		1476	sub { ... });
		1477
		1478	=cut
		1479
		1480	register_read_type regex => sub {
		1481	my ($self, $cb, $accept, $reject, $skip) = @_;
		1482
		1483	my $data;
		1484	my $rbuf = \$self->{rbuf};
675		1485
676	sub {	1486	sub {
677	$_[0]{rbuf} =~ s/$eol// or return;	1487	# accept
678		1488	if ($$rbuf =~ $accept) {
679	$cb->($_[0], $1, $2);	1489	$data .= substr $$rbuf, 0, $+[0], "";
		1490	$cb->($self, $data);
		1491	return 1;
		1492	}
680	1	1493
		1494	# reject
		1495	if ($reject && $$rbuf =~ $reject) {
		1496	$self->_error (Errno::EBADMSG);
		1497	}
		1498
		1499	# skip
		1500	if ($skip && $$rbuf =~ $skip) {
		1501	$data .= substr $$rbuf, 0, $+[0], "";
		1502	}
		1503
		1504	()
681	}	1505	}
682	};	1506	};
683		1507
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)	1508	=item netstring => $cb->($handle, $string)
696		1509
697	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).	1510	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698		1511
699	Throws an error with C<$!> set to EBADMSG on format violations.	1512	Throws an error with C<$!> set to EBADMSG on format violations.
700		1513
…		…
704	my ($self, $cb) = @_;	1517	my ($self, $cb) = @_;
705		1518
706	sub {	1519	sub {
707	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1520	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708	if ($_[0]{rbuf} =~ /[^0-9]/) {	1521	if ($_[0]{rbuf} =~ /[^0-9]/) {
709	$! = &Errno::EBADMSG;	1522	$self->_error (Errno::EBADMSG);
710	$self->error;
711	}	1523	}
712	return;	1524	return;
713	}	1525	}
714		1526
715	my $len = $1;	1527	my $len = $1;
…		…
718	my $string = $_[1];	1530	my $string = $_[1];
719	$_[0]->unshift_read (chunk => 1, sub {	1531	$_[0]->unshift_read (chunk => 1, sub {
720	if ($_[1] eq ",") {	1532	if ($_[1] eq ",") {
721	$cb->($_[0], $string);	1533	$cb->($_[0], $string);
722	} else {	1534	} else {
723	$! = &Errno::EBADMSG;
724	$self->error;	1535	$self->_error (Errno::EBADMSG);
725	}	1536	}
726	});	1537	});
727	});	1538	});
728		1539
729	1	1540	1
730	}	1541	}
731	};	1542	};
732		1543
		1544	=item packstring => $format, $cb->($handle, $string)
		1545
		1546	An octet string prefixed with an encoded length. The encoding C<$format>
		1547	uses the same format as a Perl C<pack> format, but must specify a single
		1548	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1549	optional C<!>, C<< < >> or C<< > >> modifier).
		1550
		1551	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1552	EPP uses a prefix of C<N> (4 octtes).
		1553
		1554	Example: read a block of data prefixed by its length in BER-encoded
		1555	format (very efficient).
		1556
		1557	$handle->push_read (packstring => "w", sub {
		1558	my ($handle, $data) = @_;
		1559	});
		1560
		1561	=cut
		1562
		1563	register_read_type packstring => sub {
		1564	my ($self, $cb, $format) = @_;
		1565
		1566	sub {
		1567	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1568	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1569	or return;
		1570
		1571	$format = length pack $format, $len;
		1572
		1573	# bypass unshift if we already have the remaining chunk
		1574	if ($format + $len <= length $_[0]{rbuf}) {
		1575	my $data = substr $_[0]{rbuf}, $format, $len;
		1576	substr $_[0]{rbuf}, 0, $format + $len, "";
		1577	$cb->($_[0], $data);
		1578	} else {
		1579	# remove prefix
		1580	substr $_[0]{rbuf}, 0, $format, "";
		1581
		1582	# read remaining chunk
		1583	$_[0]->unshift_read (chunk => $len, $cb);
		1584	}
		1585
		1586	1
		1587	}
		1588	};
		1589
		1590	=item json => $cb->($handle, $hash_or_arrayref)
		1591
		1592	Reads a JSON object or array, decodes it and passes it to the
		1593	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1594
		1595	If a C<json> object was passed to the constructor, then that will be used
		1596	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1597
		1598	This read type uses the incremental parser available with JSON version
		1599	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1600	dependency on your own: this module will load the JSON module, but
		1601	AnyEvent does not depend on it itself.
		1602
		1603	Since JSON texts are fully self-delimiting, the C<json> read and write
		1604	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1605	the C<json> write type description, above, for an actual example.
		1606
		1607	=cut
		1608
		1609	register_read_type json => sub {
		1610	my ($self, $cb) = @_;
		1611
		1612	my $json = $self->{json} ||= json_coder;
		1613
		1614	my $data;
		1615	my $rbuf = \$self->{rbuf};
		1616
		1617	sub {
		1618	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1619
		1620	if ($ref) {
		1621	$self->{rbuf} = $json->incr_text;
		1622	$json->incr_text = "";
		1623	$cb->($self, $ref);
		1624
		1625	1
		1626	} elsif ($@) {
		1627	# error case
		1628	$json->incr_skip;
		1629
		1630	$self->{rbuf} = $json->incr_text;
		1631	$json->incr_text = "";
		1632
		1633	$self->_error (Errno::EBADMSG);
		1634
		1635	()
		1636	} else {
		1637	$self->{rbuf} = "";
		1638
		1639	()
		1640	}
		1641	}
		1642	};
		1643
		1644	=item storable => $cb->($handle, $ref)
		1645
		1646	Deserialises a L<Storable> frozen representation as written by the
		1647	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1648	data).
		1649
		1650	Raises C<EBADMSG> error if the data could not be decoded.
		1651
		1652	=cut
		1653
		1654	register_read_type storable => sub {
		1655	my ($self, $cb) = @_;
		1656
		1657	require Storable;
		1658
		1659	sub {
		1660	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1661	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1662	or return;
		1663
		1664	my $format = length pack "w", $len;
		1665
		1666	# bypass unshift if we already have the remaining chunk
		1667	if ($format + $len <= length $_[0]{rbuf}) {
		1668	my $data = substr $_[0]{rbuf}, $format, $len;
		1669	substr $_[0]{rbuf}, 0, $format + $len, "";
		1670	$cb->($_[0], Storable::thaw ($data));
		1671	} else {
		1672	# remove prefix
		1673	substr $_[0]{rbuf}, 0, $format, "";
		1674
		1675	# read remaining chunk
		1676	$_[0]->unshift_read (chunk => $len, sub {
		1677	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1678	$cb->($_[0], $ref);
		1679	} else {
		1680	$self->_error (Errno::EBADMSG);
		1681	}
		1682	});
		1683	}
		1684
		1685	1
		1686	}
		1687	};
		1688
733	=back	1689	=back
734		1690
735	=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args)	1691	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
736		1692
737	This function (not method) lets you add your own types to C<push_read>.	1693	Instead of one of the predefined types, you can also specify the name
		1694	of a package. AnyEvent will try to load the package and then expects to
		1695	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1696	progressively tries to load the parent package until it either finds the
		1697	function (good) or runs out of packages (bad).
738		1698
739	Whenever the given C<type> is used, C<push_read> will invoke the code	1699	Whenever this type is used, C<push_read> will invoke the function with the
740	reference with the handle object, the callback and the remaining	1700	handle object, the original callback and the remaining arguments.
741	arguments.
742		1701
743	The code reference is supposed to return a callback (usually a closure)	1702	The function is supposed to return a callback (usually a closure) that
744	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1703	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1704	mentally treat the function as a "configurable read type to read callback"
		1705	converter.
745		1706
746	It should invoke the passed callback when it is done reading (remember to	1707	It should invoke the original callback when it is done reading (remember
747	pass C<$self> as first argument as all other callbacks do that).	1708	to pass C<$handle> as first argument as all other callbacks do that,
		1709	although there is no strict requirement on this).
748		1710
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>,	1711	For examples, see the source of this module (F<perldoc -m
753	search for C<register_read_type>)).	1712	AnyEvent::Handle>, search for C<register_read_type>)).
754		1713
755	=item $handle->stop_read	1714	=item $handle->stop_read
756		1715
757	=item $handle->start_read	1716	=item $handle->start_read
758		1717
759	In rare cases you actually do not want to read anything from the	1718	In rare cases you actually do not want to read anything from the
760	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1719	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761	any queued callbacks will be executed then. To start reading again, call	1720	any queued callbacks will be executed then. To start reading again, call
762	C<start_read>.	1721	C<start_read>.
763		1722
		1723	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1724	you change the C<on_read> callback or push/unshift a read callback, and it
		1725	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1726	there are any read requests in the queue.
		1727
		1728	These methods will have no effect when in TLS mode (as TLS doesn't support
		1729	half-duplex connections).
		1730
764	=cut	1731	=cut
765		1732
766	sub stop_read {	1733	sub stop_read {
767	my ($self) = @_;	1734	my ($self) = @_;
768		1735
769	delete $self->{rw};	1736	delete $self->{_rw} unless $self->{tls};
770	}	1737	}
771		1738
772	sub start_read {	1739	sub start_read {
773	my ($self) = @_;	1740	my ($self) = @_;
774		1741
775	unless ($self->{rw} || $self->{eof}) {	1742	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
776	Scalar::Util::weaken $self;	1743	Scalar::Util::weaken $self;
777		1744
778	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1745	$self->{_rw} = AE::io $self->{fh}, 0, sub {
779	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1746	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1747	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781		1748
782	if ($len > 0) {	1749	if ($len > 0) {
783	$self->{filter_r}	1750	$self->{_activity} = $self->{_ractivity} = AE::now;
784	? $self->{filter_r}->($self, $rbuf)	1751
		1752	if ($self->{tls}) {
		1753	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1754
		1755	&_dotls ($self);
		1756	} else {
785	: $self->_drain_rbuf;	1757	$self->_drain_rbuf;
		1758	}
786		1759
787	} elsif (defined $len) {	1760	} elsif (defined $len) {
788	delete $self->{rw};	1761	delete $self->{_rw};
789	$self->{eof} = 1;	1762	$self->{_eof} = 1;
790	$self->_drain_rbuf;	1763	$self->_drain_rbuf;
791		1764
792	} elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAWOULDBLOCK) {	1765	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793	return $self->error;	1766	return $self->_error ($!, 1);
794	}	1767	}
795	});	1768	};
796	}	1769	}
797	}	1770	}
798		1771
		1772	our $ERROR_SYSCALL;
		1773	our $ERROR_WANT_READ;
		1774
		1775	sub _tls_error {
		1776	my ($self, $err) = @_;
		1777
		1778	return $self->_error ($!, 1)
		1779	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1780
		1781	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1782
		1783	# reduce error string to look less scary
		1784	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1785
		1786	if ($self->{_on_starttls}) {
		1787	(delete $self->{_on_starttls})->($self, undef, $err);
		1788	&_freetls;
		1789	} else {
		1790	&_freetls;
		1791	$self->_error (Errno::EPROTO, 1, $err);
		1792	}
		1793	}
		1794
		1795	# poll the write BIO and send the data if applicable
		1796	# also decode read data if possible
		1797	# this is basiclaly our TLS state machine
		1798	# more efficient implementations are possible with openssl,
		1799	# but not with the buggy and incomplete Net::SSLeay.
799	sub _dotls {	1800	sub _dotls {
800	my ($self) = @_;	1801	my ($self) = @_;
801		1802
		1803	my $tmp;
		1804
802	if (length $self->{tls_wbuf}) {	1805	if (length $self->{_tls_wbuf}) {
803	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1806	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804	substr $self->{tls_wbuf}, 0, $len, "";	1807	substr $self->{_tls_wbuf}, 0, $tmp, "";
805	}	1808	}
806	}
807		1809
		1810	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1811	return $self->_tls_error ($tmp)
		1812	if $tmp != $ERROR_WANT_READ
		1813	&& ($tmp != $ERROR_SYSCALL || $!);
		1814	}
		1815
808	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1816	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1817	unless (length $tmp) {
		1818	$self->{_on_starttls}
		1819	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1820	&_freetls;
		1821
		1822	if ($self->{on_stoptls}) {
		1823	$self->{on_stoptls}($self);
		1824	return;
		1825	} else {
		1826	# let's treat SSL-eof as we treat normal EOF
		1827	delete $self->{_rw};
		1828	$self->{_eof} = 1;
		1829	}
		1830	}
		1831
		1832	$self->{_tls_rbuf} .= $tmp;
		1833	$self->_drain_rbuf;
		1834	$self->{tls} or return; # tls session might have gone away in callback
		1835	}
		1836
		1837	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1838	return $self->_tls_error ($tmp)
		1839	if $tmp != $ERROR_WANT_READ
		1840	&& ($tmp != $ERROR_SYSCALL || $!);
		1841
		1842	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809	$self->{wbuf} .= $buf;	1843	$self->{wbuf} .= $tmp;
810	$self->_drain_wbuf;	1844	$self->_drain_wbuf;
		1845	$self->{tls} or return; # tls session might have gone away in callback
811	}	1846	}
812		1847
813	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {	1848	$self->{_on_starttls}
814	$self->{rbuf} .= $buf;	1849	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
815	$self->_drain_rbuf;	1850	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	}	1851	}
831		1852
832	=item $handle->starttls ($tls[, $tls_ctx])	1853	=item $handle->starttls ($tls[, $tls_ctx])
833		1854
834	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1855	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	1856	object is created, you can also do that at a later time by calling
836	C<starttls>.	1857	C<starttls>.
837		1858
		1859	Starting TLS is currently an asynchronous operation - when you push some
		1860	write data and then call C<< ->starttls >> then TLS negotiation will start
		1861	immediately, after which the queued write data is then sent.
		1862
838	The first argument is the same as the C<tls> constructor argument (either	1863	The first argument is the same as the C<tls> constructor argument (either
839	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1864	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840		1865
841	The second argument is the optional C<Net::SSLeay::CTX> object that is	1866	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.	1867	when AnyEvent::Handle has to create its own TLS connection object, or
		1868	a hash reference with C<< key => value >> pairs that will be used to
		1869	construct a new context.
843		1870
844	=cut	1871	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1872	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1873	changed to your liking. Note that the handshake might have already started
		1874	when this function returns.
845		1875
846	# TODO: maybe document...	1876	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1877	handshakes on the same stream. It is best to not attempt to use the
		1878	stream after stopping TLS.
		1879
		1880	This method may invoke callbacks (and therefore the handle might be
		1881	destroyed after it returns).
		1882
		1883	=cut
		1884
		1885	our %TLS_CACHE; #TODO not yet documented, should we?
		1886
847	sub starttls {	1887	sub starttls {
848	my ($self, $ssl, $ctx) = @_;	1888	my ($self, $tls, $ctx) = @_;
849		1889
850	$self->stoptls;	1890	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1891	if $self->{tls};
851		1892
852	if ($ssl eq "accept") {	1893	$self->{tls} = $tls;
853	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1894	$self->{tls_ctx} = $ctx if @_ > 2;
854	Net::SSLeay::set_accept_state ($ssl);	1895
855	} elsif ($ssl eq "connect") {	1896	return unless $self->{fh};
856	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1897
857	Net::SSLeay::set_connect_state ($ssl);	1898	require Net::SSLeay;
		1899
		1900	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1901	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1902
		1903	$tls = delete $self->{tls};
		1904	$ctx = $self->{tls_ctx};
		1905
		1906	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1907
		1908	if ("HASH" eq ref $ctx) {
		1909	require AnyEvent::TLS;
		1910
		1911	if ($ctx->{cache}) {
		1912	my $key = $ctx+0;
		1913	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1914	} else {
		1915	$ctx = new AnyEvent::TLS %$ctx;
		1916	}
		1917	}
858	}	1918
859		1919	$self->{tls_ctx} = $ctx || TLS_CTX ();
860	$self->{tls} = $ssl;	1920	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
861		1921
862	# basically, this is deep magic (because SSL_read should have the same issues)	1922	# basically, this is deep magic (because SSL_read should have the same issues)
863	# but the openssl maintainers basically said: "trust us, it just works".	1923	# but the openssl maintainers basically said: "trust us, it just works".
864	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1924	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
865	# and mismaintained ssleay-module doesn't even offer them).	1925	# and mismaintained ssleay-module doesn't even offer them).
866	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1926	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1927	#
		1928	# in short: this is a mess.
		1929	#
		1930	# note that we do not try to keep the length constant between writes as we are required to do.
		1931	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1932	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1933	# have identity issues in that area.
867	Net::SSLeay::CTX_set_mode ($self->{tls},	1934	# Net::SSLeay::CTX_set_mode ($ssl,
868	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	1935	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	1936	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1937	Net::SSLeay::CTX_set_mode ($tls, 1|2);
870		1938
871	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1939	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1940	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873		1941
		1942	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1943
874	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	1944	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
875		1945
876	$self->{filter_w} = sub {	1946	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
877	$_[0]{tls_wbuf} .= ${$_[1]};	1947	if $self->{on_starttls};
878	&_dotls;	1948
879	};	1949	&_dotls; # need to trigger the initial handshake
880	$self->{filter_r} = sub {	1950	$self->start_read; # make sure we actually do read
881	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882	&_dotls;
883	};
884	}	1951	}
885		1952
886	=item $handle->stoptls	1953	=item $handle->stoptls
887		1954
888	Destroys the SSL connection, if any. Partial read or write data will be	1955	Shuts down the SSL connection - this makes a proper EOF handshake by
889	lost.	1956	sending a close notify to the other side, but since OpenSSL doesn't
		1957	support non-blocking shut downs, it is not guaranteed that you can re-use
		1958	the stream afterwards.
		1959
		1960	This method may invoke callbacks (and therefore the handle might be
		1961	destroyed after it returns).
890		1962
891	=cut	1963	=cut
892		1964
893	sub stoptls {	1965	sub stoptls {
894	my ($self) = @_;	1966	my ($self) = @_;
895		1967
896	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	1968	if ($self->{tls} && $self->{fh}) {
897	delete $self->{tls_rbio};	1969	Net::SSLeay::shutdown ($self->{tls});
898	delete $self->{tls_wbio};	1970
899	delete $self->{tls_wbuf};	1971	&_dotls;
900	delete $self->{filter_r};	1972
901	delete $self->{filter_w};	1973	# # we don't give a shit. no, we do, but we can't. no...#d#
		1974	# # we, we... have to use openssl :/#d#
		1975	# &_freetls;#d#
		1976	}
		1977	}
		1978
		1979	sub _freetls {
		1980	my ($self) = @_;
		1981
		1982	return unless $self->{tls};
		1983
		1984	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1985	if $self->{tls} > 0;
		1986
		1987	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
902	}	1988	}
903		1989
904	sub DESTROY {	1990	sub DESTROY {
905	my $self = shift;	1991	my ($self) = @_;
906		1992
907	$self->stoptls;	1993	&_freetls;
		1994
		1995	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1996
		1997	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1998	my $fh = delete $self->{fh};
		1999	my $wbuf = delete $self->{wbuf};
		2000
		2001	my @linger;
		2002
		2003	push @linger, AE::io $fh, 1, sub {
		2004	my $len = syswrite $fh, $wbuf, length $wbuf;
		2005
		2006	if ($len > 0) {
		2007	substr $wbuf, 0, $len, "";
		2008	} else {
		2009	@linger = (); # end
		2010	}
		2011	};
		2012	push @linger, AE::timer $linger, 0, sub {
		2013	@linger = ();
		2014	};
		2015	}
908	}	2016	}
		2017
		2018	=item $handle->destroy
		2019
		2020	Shuts down the handle object as much as possible - this call ensures that
		2021	no further callbacks will be invoked and as many resources as possible
		2022	will be freed. Any method you will call on the handle object after
		2023	destroying it in this way will be silently ignored (and it will return the
		2024	empty list).
		2025
		2026	Normally, you can just "forget" any references to an AnyEvent::Handle
		2027	object and it will simply shut down. This works in fatal error and EOF
		2028	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2029	callback, so when you want to destroy the AnyEvent::Handle object from
		2030	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2031	that case.
		2032
		2033	Destroying the handle object in this way has the advantage that callbacks
		2034	will be removed as well, so if those are the only reference holders (as
		2035	is common), then one doesn't need to do anything special to break any
		2036	reference cycles.
		2037
		2038	The handle might still linger in the background and write out remaining
		2039	data, as specified by the C<linger> option, however.
		2040
		2041	=cut
		2042
		2043	sub destroy {
		2044	my ($self) = @_;
		2045
		2046	$self->DESTROY;
		2047	%$self = ();
		2048	bless $self, "AnyEvent::Handle::destroyed";
		2049	}
		2050
		2051	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2052	#nop
		2053	}
		2054
		2055	=item $handle->destroyed
		2056
		2057	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2058	->destroy >>, true otherwise.
		2059
		2060	Can be useful to decide whether the handle is still valid after some
		2061	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2062	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2063	can destroy the handle, so work can be avoided by checking sometimes:
		2064
		2065	$hdl->starttls ("accept");
		2066	return if $hdl->destroyed;
		2067	$hdl->push_write (...
		2068
		2069	Note that the call to C<push_write> will silently be ignored if the handle
		2070	has been destroyed, so often you can just ignore the possibility of the
		2071	handle being destroyed.
		2072
		2073	=cut
		2074
		2075	sub destroyed { 0 }
		2076	sub AnyEvent::Handle::destroyed::destroyed { 1 }
909		2077
910	=item AnyEvent::Handle::TLS_CTX	2078	=item AnyEvent::Handle::TLS_CTX
911		2079
912	This function creates and returns the Net::SSLeay::CTX object used by	2080	This function creates and returns the AnyEvent::TLS object used by default
913	default for TLS mode.	2081	for TLS mode.
914		2082
915	The context is created like this:	2083	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		2084
925	=cut	2085	=cut
926		2086
927	our $TLS_CTX;	2087	our $TLS_CTX;
928		2088
929	sub TLS_CTX() {	2089	sub TLS_CTX() {
930	$TLS_CTX || do {	2090	$TLS_CTX ||= do {
931	require Net::SSLeay;	2091	require AnyEvent::TLS;
932		2092
933	Net::SSLeay::load_error_strings ();	2093	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	$TLS_CTX
942	}	2094	}
943	}	2095	}
944		2096
945	=back	2097	=back
946		2098
		2099
		2100	=head1 NONFREQUENTLY ASKED QUESTIONS
		2101
		2102	=over 4
		2103
		2104	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2105	still get further invocations!
		2106
		2107	That's because AnyEvent::Handle keeps a reference to itself when handling
		2108	read or write callbacks.
		2109
		2110	It is only safe to "forget" the reference inside EOF or error callbacks,
		2111	from within all other callbacks, you need to explicitly call the C<<
		2112	->destroy >> method.
		2113
		2114	=item I get different callback invocations in TLS mode/Why can't I pause
		2115	reading?
		2116
		2117	Unlike, say, TCP, TLS connections do not consist of two independent
		2118	communication channels, one for each direction. Or put differently, the
		2119	read and write directions are not independent of each other: you cannot
		2120	write data unless you are also prepared to read, and vice versa.
		2121
		2122	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
		2123	callback invocations when you are not expecting any read data - the reason
		2124	is that AnyEvent::Handle always reads in TLS mode.
		2125
		2126	During the connection, you have to make sure that you always have a
		2127	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2128	connection (or when you no longer want to use it) you can call the
		2129	C<destroy> method.
		2130
		2131	=item How do I read data until the other side closes the connection?
		2132
		2133	If you just want to read your data into a perl scalar, the easiest way
		2134	to achieve this is by setting an C<on_read> callback that does nothing,
		2135	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2136	will be in C<$_[0]{rbuf}>:
		2137
		2138	$handle->on_read (sub { });
		2139	$handle->on_eof (undef);
		2140	$handle->on_error (sub {
		2141	my $data = delete $_[0]{rbuf};
		2142	});
		2143
		2144	The reason to use C<on_error> is that TCP connections, due to latencies
		2145	and packets loss, might get closed quite violently with an error, when in
		2146	fact all data has been received.
		2147
		2148	It is usually better to use acknowledgements when transferring data,
		2149	to make sure the other side hasn't just died and you got the data
		2150	intact. This is also one reason why so many internet protocols have an
		2151	explicit QUIT command.
		2152
		2153	=item I don't want to destroy the handle too early - how do I wait until
		2154	all data has been written?
		2155
		2156	After writing your last bits of data, set the C<on_drain> callback
		2157	and destroy the handle in there - with the default setting of
		2158	C<low_water_mark> this will be called precisely when all data has been
		2159	written to the socket:
		2160
		2161	$handle->push_write (...);
		2162	$handle->on_drain (sub {
		2163	warn "all data submitted to the kernel\n";
		2164	undef $handle;
		2165	});
		2166
		2167	If you just want to queue some data and then signal EOF to the other side,
		2168	consider using C<< ->push_shutdown >> instead.
		2169
		2170	=item I want to contact a TLS/SSL server, I don't care about security.
		2171
		2172	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2173	connect to it and then create the AnyEvent::Handle with the C<tls>
		2174	parameter:
		2175
		2176	tcp_connect $host, $port, sub {
		2177	my ($fh) = @_;
		2178
		2179	my $handle = new AnyEvent::Handle
		2180	fh => $fh,
		2181	tls => "connect",
		2182	on_error => sub { ... };
		2183
		2184	$handle->push_write (...);
		2185	};
		2186
		2187	=item I want to contact a TLS/SSL server, I do care about security.
		2188
		2189	Then you should additionally enable certificate verification, including
		2190	peername verification, if the protocol you use supports it (see
		2191	L<AnyEvent::TLS>, C<verify_peername>).
		2192
		2193	E.g. for HTTPS:
		2194
		2195	tcp_connect $host, $port, sub {
		2196	my ($fh) = @_;
		2197
		2198	my $handle = new AnyEvent::Handle
		2199	fh => $fh,
		2200	peername => $host,
		2201	tls => "connect",
		2202	tls_ctx => { verify => 1, verify_peername => "https" },
		2203	...
		2204
		2205	Note that you must specify the hostname you connected to (or whatever
		2206	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2207	peername verification will be done.
		2208
		2209	The above will use the system-dependent default set of trusted CA
		2210	certificates. If you want to check against a specific CA, add the
		2211	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2212
		2213	tls_ctx => {
		2214	verify => 1,
		2215	verify_peername => "https",
		2216	ca_file => "my-ca-cert.pem",
		2217	},
		2218
		2219	=item I want to create a TLS/SSL server, how do I do that?
		2220
		2221	Well, you first need to get a server certificate and key. You have
		2222	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2223	self-signed certificate (cheap. check the search engine of your choice,
		2224	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2225	nice program for that purpose).
		2226
		2227	Then create a file with your private key (in PEM format, see
		2228	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2229	file should then look like this:
		2230
		2231	-----BEGIN RSA PRIVATE KEY-----
		2232	...header data
		2233	... lots of base64'y-stuff
		2234	-----END RSA PRIVATE KEY-----
		2235
		2236	-----BEGIN CERTIFICATE-----
		2237	... lots of base64'y-stuff
		2238	-----END CERTIFICATE-----
		2239
		2240	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2241	specify this file as C<cert_file>:
		2242
		2243	tcp_server undef, $port, sub {
		2244	my ($fh) = @_;
		2245
		2246	my $handle = new AnyEvent::Handle
		2247	fh => $fh,
		2248	tls => "accept",
		2249	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2250	...
		2251
		2252	When you have intermediate CA certificates that your clients might not
		2253	know about, just append them to the C<cert_file>.
		2254
		2255	=back
		2256
		2257
		2258	=head1 SUBCLASSING AnyEvent::Handle
		2259
		2260	In many cases, you might want to subclass AnyEvent::Handle.
		2261
		2262	To make this easier, a given version of AnyEvent::Handle uses these
		2263	conventions:
		2264
		2265	=over 4
		2266
		2267	=item * all constructor arguments become object members.
		2268
		2269	At least initially, when you pass a C<tls>-argument to the constructor it
		2270	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2271	mutated later on (for example C<tls> will hold the TLS connection object).
		2272
		2273	=item * other object member names are prefixed with an C<_>.
		2274
		2275	All object members not explicitly documented (internal use) are prefixed
		2276	with an underscore character, so the remaining non-C<_>-namespace is free
		2277	for use for subclasses.
		2278
		2279	=item * all members not documented here and not prefixed with an underscore
		2280	are free to use in subclasses.
		2281
		2282	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2283	member variables, but that's just life. At least it is documented.
		2284
		2285	=back
		2286
947	=head1 AUTHOR	2287	=head1 AUTHOR
948		2288
949	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2289	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950		2290
951	=cut	2291	=cut

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