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Revision 1.192 by root, Fri Mar 12 23:22:14 2010 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict;
5
6	use AnyEvent ();
7	use AnyEvent::Util ();
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 filehandles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16
17	=cut
18
19	our $VERSION = '0.02';
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 $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	12	my $hdl; $hdl = new AnyEvent::Handle
29
30	#TODO
31
32	# or use the constructor to pass the callback:
33
34	my $ae_fh2 =
35	AnyEvent::Handle->new (
36	fh => \*STDIN,	13	fh => \*STDIN,
37	on_eof => sub {	14	on_error => sub {
38	$cv->broadcast;	15	my ($hdl, $fatal, $msg) = @_;
39	},	16	warn "got error $msg\n";
40	#TODO	17	$hdl->destroy;
		18	$cv->send;
41	);	19	};
42		20
43	$cv->wait;	21	# send some request line
		22	$hdl->push_write ("getinfo\015\012");
		23
		24	# read the response line
		25	$hdl->push_read (line => sub {
		26	my ($hdl, $line) = @_;
		27	warn "got line <$line>\n";
		28	$cv->send;
		29	});
		30
		31	$cv->recv;
44		32
45	=head1 DESCRIPTION	33	=head1 DESCRIPTION
46		34
47	This module is a helper module to make it easier to do event-based I/O on	35	This module is a helper module to make it easier to do event-based I/O on
48	filehandles (and sockets, see L<AnyEvent::Socket> for an easy way to make	36	filehandles.
49	non-blocking resolves and connects).	37
		38	The L<AnyEvent::Intro> tutorial contains some well-documented
		39	AnyEvent::Handle examples.
50		40
51	In the following, when the documentation refers to of "bytes" then this	41	In the following, when the documentation refers to of "bytes" then this
52	means characters. As sysread and syswrite are used for all I/O, their	42	means characters. As sysread and syswrite are used for all I/O, their
53	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
54		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
		47
55	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
56	argument.	49	argument.
57		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
58	=head1 METHODS	80	=head1 METHODS
59		81
60	=over 4	82	=over 4
61		83
62	=item B<new (%args)>	84	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
63		85
64	The constructor supports these arguments (all as key => value pairs).	86	The constructor supports these arguments (all as C<< key => value >> pairs).
65		87
66	=over 4	88	=over 4
67		89
68	=item fh => $filehandle [MANDATORY]	90	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
69		91
70	The filehandle this L<AnyEvent::Handle> object will operate on.	92	The filehandle this L<AnyEvent::Handle> object will operate on.
71
72	NOTE: The filehandle will be set to non-blocking (using	93	NOTE: The filehandle will be set to non-blocking mode (using
73	AnyEvent::Util::fh_nonblocking).	94	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		95	that mode.
74		96
75	=item on_error => $cb->($self) [MANDATORY]	97	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
76		98
77	This is the fatal error callback, that is called when a fatal error ocurs,	99	Try to connect to the specified host and service (port), using
		100	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		101	default C<peername>.
		102
		103	You have to specify either this parameter, or C<fh>, above.
		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
		114	=item on_prepare => $cb->($handle)
		115
		116	This (rarely used) callback is called before a new connection is
		117	attempted, but after the file handle has been created. It could be used to
		118	prepare the file handle with parameters required for the actual connect
		119	(as opposed to settings that can be changed when the connection is already
		120	established).
		121
		122	The return value of this callback should be the connect timeout value in
		123	seconds (or C<0>, or C<undef>, or the empty list, to indicate the default
		124	timeout is to be used).
		125
		126	=item on_connect => $cb->($handle, $host, $port, $retry->())
		127
		128	This callback is called when a connection has been successfully established.
		129
		130	The actual numeric host and port (the socket peername) are passed as
		131	parameters, together with a retry callback.
		132
		133	When, for some reason, the handle is not acceptable, then calling
		134	C<$retry> will continue with the next connection target (in case of
		135	multi-homed hosts or SRV records there can be multiple connection
		136	endpoints). At the time it is called the read and write queues, eof
		137	status, tls status and similar properties of the handle will have been
		138	reset.
		139
		140	In most cases, ignoring the C<$retry> parameter is the way to go.
		141
		142	=item on_connect_error => $cb->($handle, $message)
		143
		144	This callback is called when the connection could not be
		145	established. C<$!> will contain the relevant error code, and C<$message> a
		146	message describing it (usually the same as C<"$!">).
		147
		148	If this callback isn't specified, then C<on_error> will be called with a
		149	fatal error instead.
		150
		151	=back
		152
		153	=item on_error => $cb->($handle, $fatal, $message)
		154
		155	This is the error callback, which is called when, well, some error
78	such as not being able to resolve the hostname, failure to connect or a	156	occured, such as not being able to resolve the hostname, failure to
79	read error.	157	connect or a read error.
80		158
81	The object will not be in a usable state when this callback has been	159	Some errors are fatal (which is indicated by C<$fatal> being true). On
82	called.	160	fatal errors the handle object will be destroyed (by a call to C<< ->
		161	destroy >>) after invoking the error callback (which means you are free to
		162	examine the handle object). Examples of fatal errors are an EOF condition
		163	with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In
		164	cases where the other side can close the connection at their will it is
		165	often easiest to not report C<EPIPE> errors in this callback.
83		166
		167	AnyEvent::Handle tries to find an appropriate error code for you to check
		168	against, but in some cases (TLS errors), this does not work well. It is
		169	recommended to always output the C<$message> argument in human-readable
		170	error messages (it's usually the same as C<"$!">).
		171
		172	Non-fatal errors can be retried by simply returning, but it is recommended
		173	to simply ignore this parameter and instead abondon the handle object
		174	when this callback is invoked. Examples of non-fatal errors are timeouts
		175	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		176
84	On callback entrance, the value of C<$!> contains the opertaing system	177	On callback entrance, the value of C<$!> contains the operating system
85	error (or C<ENOSPC> or C<EPIPE>).	178	error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		179	C<EPROTO>).
86		180
87	=item on_eof => $cb->($self) [MANDATORY]	181	While not mandatory, it is I<highly> recommended to set this callback, as
		182	you will not be notified of errors otherwise. The default simply calls
		183	C<croak>.
88		184
89	Set the callback to be called on EOF.
90
91	=item on_read => $cb->($self)	185	=item on_read => $cb->($handle)
92		186
93	This sets the default read callback, which is called when data arrives	187	This sets the default read callback, which is called when data arrives
94	and no read request is in the queue. If the read callback is C<undef>	188	and no read request is in the queue (unlike read queue callbacks, this
95	or has never been set, than AnyEvent::Handle will cease reading from the	189	callback will only be called when at least one octet of data is in the
96	filehandle.	190	read buffer).
97		191
98	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	192	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
99	method or acces sthe C<$self->{rbuf}> member directly.	193	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		194	must not enlarge or modify the read buffer, you can only remove data at
		195	the beginning from it.
100		196
101	When an EOF condition is detected then AnyEvent::Handle will first try to	197	When an EOF condition is detected then AnyEvent::Handle will first try to
102	feed all the remaining data to the queued callbacks and C<on_read> before	198	feed all the remaining data to the queued callbacks and C<on_read> before
103	calling the C<on_eof> callback. If no progress can be made, then a fatal	199	calling the C<on_eof> callback. If no progress can be made, then a fatal
104	error will be raised (with C<$!> set to C<EPIPE>).	200	error will be raised (with C<$!> set to C<EPIPE>).
105		201
		202	Note that, unlike requests in the read queue, an C<on_read> callback
		203	doesn't mean you I<require> some data: if there is an EOF and there
		204	are outstanding read requests then an error will be flagged. With an
		205	C<on_read> callback, the C<on_eof> callback will be invoked.
		206
		207	=item on_eof => $cb->($handle)
		208
		209	Set the callback to be called when an end-of-file condition is detected,
		210	i.e. in the case of a socket, when the other side has closed the
		211	connection cleanly, and there are no outstanding read requests in the
		212	queue (if there are read requests, then an EOF counts as an unexpected
		213	connection close and will be flagged as an error).
		214
		215	For sockets, this just means that the other side has stopped sending data,
		216	you can still try to write data, and, in fact, one can return from the EOF
		217	callback and continue writing data, as only the read part has been shut
		218	down.
		219
		220	If an EOF condition has been detected but no C<on_eof> callback has been
		221	set, then a fatal error will be raised with C<$!> set to <0>.
		222
106	=item on_drain => $cb->()	223	=item on_drain => $cb->($handle)
107		224
108	This sets the callback that is called when the write buffer becomes empty	225	This sets the callback that is called when the write buffer becomes empty
109	(or when the callback is set and the buffer is empty already).	226	(or when the callback is set and the buffer is empty already).
110		227
111	To append to the write buffer, use the C<< ->push_write >> method.	228	To append to the write buffer, use the C<< ->push_write >> method.
112		229
		230	This callback is useful when you don't want to put all of your write data
		231	into the queue at once, for example, when you want to write the contents
		232	of some file to the socket you might not want to read the whole file into
		233	memory and push it into the queue, but instead only read more data from
		234	the file when the write queue becomes empty.
		235
		236	=item timeout => $fractional_seconds
		237
		238	=item rtimeout => $fractional_seconds
		239
		240	=item wtimeout => $fractional_seconds
		241
		242	If non-zero, then these enables an "inactivity" timeout: whenever this
		243	many seconds pass without a successful read or write on the underlying
		244	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
		245	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		246	error will be raised).
		247
		248	There are three variants of the timeouts that work fully independent
		249	of each other, for both read and write, just read, and just write:
		250	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		251	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		252	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		253
		254	Note that timeout processing is also active when you currently do not have
		255	any outstanding read or write requests: If you plan to keep the connection
		256	idle then you should disable the timout temporarily or ignore the timeout
		257	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		258	restart the timeout.
		259
		260	Zero (the default) disables this timeout.
		261
		262	=item on_timeout => $cb->($handle)
		263
		264	Called whenever the inactivity timeout passes. If you return from this
		265	callback, then the timeout will be reset as if some activity had happened,
		266	so this condition is not fatal in any way.
		267
113	=item rbuf_max => <bytes>	268	=item rbuf_max => <bytes>
114		269
115	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	270	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
116	when the read buffer ever (strictly) exceeds this size. This is useful to	271	when the read buffer ever (strictly) exceeds this size. This is useful to
117	avoid denial-of-service attacks.	272	avoid some forms of denial-of-service attacks.
118		273
119	For example, a server accepting connections from untrusted sources should	274	For example, a server accepting connections from untrusted sources should
120	be configured to accept only so-and-so much data that it cannot act on	275	be configured to accept only so-and-so much data that it cannot act on
121	(for example, when expecting a line, an attacker could send an unlimited	276	(for example, when expecting a line, an attacker could send an unlimited
122	amount of data without a callback ever being called as long as the line	277	amount of data without a callback ever being called as long as the line
123	isn't finished).	278	isn't finished).
124		279
		280	=item autocork => <boolean>
		281
		282	When disabled (the default), then C<push_write> will try to immediately
		283	write the data to the handle, if possible. This avoids having to register
		284	a write watcher and wait for the next event loop iteration, but can
		285	be inefficient if you write multiple small chunks (on the wire, this
		286	disadvantage is usually avoided by your kernel's nagle algorithm, see
		287	C<no_delay>, but this option can save costly syscalls).
		288
		289	When enabled, then writes will always be queued till the next event loop
		290	iteration. This is efficient when you do many small writes per iteration,
		291	but less efficient when you do a single write only per iteration (or when
		292	the write buffer often is full). It also increases write latency.
		293
		294	=item no_delay => <boolean>
		295
		296	When doing small writes on sockets, your operating system kernel might
		297	wait a bit for more data before actually sending it out. This is called
		298	the Nagle algorithm, and usually it is beneficial.
		299
		300	In some situations you want as low a delay as possible, which can be
		301	accomplishd by setting this option to a true value.
		302
		303	The default is your opertaing system's default behaviour (most likely
		304	enabled), this option explicitly enables or disables it, if possible.
		305
		306	=item keepalive => <boolean>
		307
		308	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		309	normally, TCP connections have no time-out once established, so TCP
		310	connections, once established, can stay alive forever even when the other
		311	side has long gone. TCP keepalives are a cheap way to take down long-lived
		312	TCP connections whent he other side becomes unreachable. While the default
		313	is OS-dependent, TCP keepalives usually kick in after around two hours,
		314	and, if the other side doesn't reply, take down the TCP connection some 10
		315	to 15 minutes later.
		316
		317	It is harmless to specify this option for file handles that do not support
		318	keepalives, and enabling it on connections that are potentially long-lived
		319	is usually a good idea.
		320
		321	=item oobinline => <boolean>
		322
		323	BSD majorly fucked up the implementation of TCP urgent data. The result
		324	is that almost no OS implements TCP according to the specs, and every OS
		325	implements it slightly differently.
		326
		327	If you want to handle TCP urgent data, then setting this flag (the default
		328	is enabled) gives you the most portable way of getting urgent data, by
		329	putting it into the stream.
		330
		331	Since BSD emulation of OOB data on top of TCP's urgent data can have
		332	security implications, AnyEvent::Handle sets this flag automatically
		333	unless explicitly specified. Note that setting this flag after
		334	establishing a connection I<may> be a bit too late (data loss could
		335	already have occured on BSD systems), but at least it will protect you
		336	from most attacks.
		337
125	=item read_size => <bytes>	338	=item read_size => <bytes>
126		339
127	The default read block size (the amount of bytes this module will try to read	340	The default read block size (the amount of bytes this module will
128	on each [loop iteration). Default: C<4096>.	341	try to read during each loop iteration, which affects memory
		342	requirements). Default: C<8192>.
129		343
130	=item low_water_mark => <bytes>	344	=item low_water_mark => <bytes>
131		345
132	Sets the amount of bytes (default: C<0>) that make up an "empty" write	346	Sets the amount of bytes (default: C<0>) that make up an "empty" write
133	buffer: If the write reaches this size or gets even samller it is	347	buffer: If the write reaches this size or gets even samller it is
134	considered empty.	348	considered empty.
135		349
		350	Sometimes it can be beneficial (for performance reasons) to add data to
		351	the write buffer before it is fully drained, but this is a rare case, as
		352	the operating system kernel usually buffers data as well, so the default
		353	is good in almost all cases.
		354
		355	=item linger => <seconds>
		356
		357	If non-zero (default: C<3600>), then the destructor of the
		358	AnyEvent::Handle object will check whether there is still outstanding
		359	write data and will install a watcher that will write this data to the
		360	socket. No errors will be reported (this mostly matches how the operating
		361	system treats outstanding data at socket close time).
		362
		363	This will not work for partial TLS data that could not be encoded
		364	yet. This data will be lost. Calling the C<stoptls> method in time might
		365	help.
		366
		367	=item peername => $string
		368
		369	A string used to identify the remote site - usually the DNS hostname
		370	(I<not> IDN!) used to create the connection, rarely the IP address.
		371
		372	Apart from being useful in error messages, this string is also used in TLS
		373	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		374	verification will be skipped when C<peername> is not specified or
		375	C<undef>.
		376
		377	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		378
		379	When this parameter is given, it enables TLS (SSL) mode, that means
		380	AnyEvent will start a TLS handshake as soon as the connection has been
		381	established and will transparently encrypt/decrypt data afterwards.
		382
		383	All TLS protocol errors will be signalled as C<EPROTO>, with an
		384	appropriate error message.
		385
		386	TLS mode requires Net::SSLeay to be installed (it will be loaded
		387	automatically when you try to create a TLS handle): this module doesn't
		388	have a dependency on that module, so if your module requires it, you have
		389	to add the dependency yourself.
		390
		391	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		392	C<accept>, and for the TLS client side of a connection, use C<connect>
		393	mode.
		394
		395	You can also provide your own TLS connection object, but you have
		396	to make sure that you call either C<Net::SSLeay::set_connect_state>
		397	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		398	AnyEvent::Handle. Also, this module will take ownership of this connection
		399	object.
		400
		401	At some future point, AnyEvent::Handle might switch to another TLS
		402	implementation, then the option to use your own session object will go
		403	away.
		404
		405	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		406	passing in the wrong integer will lead to certain crash. This most often
		407	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		408	segmentation fault.
		409
		410	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		411
		412	=item tls_ctx => $anyevent_tls
		413
		414	Use the given C<AnyEvent::TLS> object to create the new TLS connection
		415	(unless a connection object was specified directly). If this parameter is
		416	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		417
		418	Instead of an object, you can also specify a hash reference with C<< key
		419	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		420	new TLS context object.
		421
		422	=item on_starttls => $cb->($handle, $success[, $error_message])
		423
		424	This callback will be invoked when the TLS/SSL handshake has finished. If
		425	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		426	(C<on_stoptls> will not be called in this case).
		427
		428	The session in C<< $handle->{tls} >> can still be examined in this
		429	callback, even when the handshake was not successful.
		430
		431	TLS handshake failures will not cause C<on_error> to be invoked when this
		432	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		433
		434	Without this callback, handshake failures lead to C<on_error> being
		435	called, as normal.
		436
		437	Note that you cannot call C<starttls> right again in this callback. If you
		438	need to do that, start an zero-second timer instead whose callback can
		439	then call C<< ->starttls >> again.
		440
		441	=item on_stoptls => $cb->($handle)
		442
		443	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		444	set, then it will be invoked after freeing the TLS session. If it is not,
		445	then a TLS shutdown condition will be treated like a normal EOF condition
		446	on the handle.
		447
		448	The session in C<< $handle->{tls} >> can still be examined in this
		449	callback.
		450
		451	This callback will only be called on TLS shutdowns, not when the
		452	underlying handle signals EOF.
		453
		454	=item json => JSON or JSON::XS object
		455
		456	This is the json coder object used by the C<json> read and write types.
		457
		458	If you don't supply it, then AnyEvent::Handle will create and use a
		459	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		460	texts.
		461
		462	Note that you are responsible to depend on the JSON module if you want to
		463	use this functionality, as AnyEvent does not have a dependency itself.
		464
136	=back	465	=back
137		466
138	=cut	467	=cut
139		468
140	sub new {	469	sub new {
141	my $class = shift;	470	my $class = shift;
142
143	my $self = bless { @_ }, $class;	471	my $self = bless { @_ }, $class;
144		472
145	$self->{fh} or Carp::croak "mandatory argument fh is missing";	473	if ($self->{fh}) {
		474	$self->_start;
		475	return unless $self->{fh}; # could be gone by now
		476
		477	} elsif ($self->{connect}) {
		478	require AnyEvent::Socket;
		479
		480	$self->{peername} = $self->{connect}[0]
		481	unless exists $self->{peername};
		482
		483	$self->{_skip_drain_rbuf} = 1;
		484
		485	{
		486	Scalar::Util::weaken (my $self = $self);
		487
		488	$self->{_connect} =
		489	AnyEvent::Socket::tcp_connect (
		490	$self->{connect}[0],
		491	$self->{connect}[1],
		492	sub {
		493	my ($fh, $host, $port, $retry) = @_;
		494
		495	if ($fh) {
		496	$self->{fh} = $fh;
		497
		498	delete $self->{_skip_drain_rbuf};
		499	$self->_start;
		500
		501	$self->{on_connect}
		502	and $self->{on_connect}($self, $host, $port, sub {
		503	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		504	$self->{_skip_drain_rbuf} = 1;
		505	&$retry;
		506	});
		507
		508	} else {
		509	if ($self->{on_connect_error}) {
		510	$self->{on_connect_error}($self, "$!");
		511	$self->destroy;
		512	} else {
		513	$self->_error ($!, 1);
		514	}
		515	}
		516	},
		517	sub {
		518	local $self->{fh} = $_[0];
		519
		520	$self->{on_prepare}
		521	? $self->{on_prepare}->($self)
		522	: ()
		523	}
		524	);
		525	}
		526
		527	} else {
		528	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		529	}
		530
		531	$self
		532	}
		533
		534	sub _start {
		535	my ($self) = @_;
146		536
147	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	537	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
148		538
149	$self->on_error ((delete $self->{on_error}) or Carp::croak "mandatory argument on_error is missing");	539	$self->{_activity} =
150	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	540	$self->{_ractivity} =
		541	$self->{_wactivity} = AE::now;
151		542
		543	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		544	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		545	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		546
		547	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		548	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		549
		550	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		551
		552	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
		553	if $self->{tls};
		554
152	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	555	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
153	$self->on_read (delete $self->{on_read} ) if $self->{on_read};
154		556
155	$self	557	$self->start_read
156	}	558	if $self->{on_read} || @{ $self->{_queue} };
157		559
158	sub _shutdown {	560	$self->_drain_wbuf;
159	my ($self) = @_;
160
161	delete $self->{rw};
162	delete $self->{ww};
163	delete $self->{fh};
164	}	561	}
165		562
166	sub error {	563	sub _error {
167	my ($self) = @_;	564	my ($self, $errno, $fatal, $message) = @_;
168		565
169	{	566	$! = $errno;
170	local $!;	567	$message ||= "$!";
		568
		569	if ($self->{on_error}) {
		570	$self->{on_error}($self, $fatal, $message);
		571	$self->destroy if $fatal;
		572	} elsif ($self->{fh} || $self->{connect}) {
171	$self->_shutdown;	573	$self->destroy;
		574	Carp::croak "AnyEvent::Handle uncaught error: $message";
172	}	575	}
173
174	$self->{on_error}($self);
175	}	576	}
176		577
177	=item $fh = $handle->fh	578	=item $fh = $handle->fh
178		579
179	This method returns the filehandle of the L<AnyEvent::Handle> object.	580	This method returns the file handle used to create the L<AnyEvent::Handle> object.
180		581
181	=cut	582	=cut
182		583
183	sub fh { $_[0]->{fh} }	584	sub fh { $_[0]{fh} }
184		585
185	=item $handle->on_error ($cb)	586	=item $handle->on_error ($cb)
186		587
187	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	588	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
188		589
…		…
196		597
197	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).	598	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
198		599
199	=cut	600	=cut
200		601
201	#############################################################################
202
203	sub on_eof {	602	sub on_eof {
204	$_[0]{on_eof} = $_[1];	603	$_[0]{on_eof} = $_[1];
205	}	604	}
206		605
		606	=item $handle->on_timeout ($cb)
		607
		608	=item $handle->on_rtimeout ($cb)
		609
		610	=item $handle->on_wtimeout ($cb)
		611
		612	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
		613	callback, or disables the callback (but not the timeout) if C<$cb> =
		614	C<undef>. See the C<timeout> constructor argument and method.
		615
		616	=cut
		617
		618	# see below
		619
		620	=item $handle->autocork ($boolean)
		621
		622	Enables or disables the current autocork behaviour (see C<autocork>
		623	constructor argument). Changes will only take effect on the next write.
		624
		625	=cut
		626
		627	sub autocork {
		628	$_[0]{autocork} = $_[1];
		629	}
		630
		631	=item $handle->no_delay ($boolean)
		632
		633	Enables or disables the C<no_delay> setting (see constructor argument of
		634	the same name for details).
		635
		636	=cut
		637
		638	sub no_delay {
		639	$_[0]{no_delay} = $_[1];
		640
		641	eval {
		642	local $SIG{__DIE__};
		643	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		644	if $_[0]{fh};
		645	};
		646	}
		647
		648	=item $handle->keepalive ($boolean)
		649
		650	Enables or disables the C<keepalive> setting (see constructor argument of
		651	the same name for details).
		652
		653	=cut
		654
		655	sub keepalive {
		656	$_[0]{keepalive} = $_[1];
		657
		658	eval {
		659	local $SIG{__DIE__};
		660	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		661	if $_[0]{fh};
		662	};
		663	}
		664
		665	=item $handle->oobinline ($boolean)
		666
		667	Enables or disables the C<oobinline> setting (see constructor argument of
		668	the same name for details).
		669
		670	=cut
		671
		672	sub oobinline {
		673	$_[0]{oobinline} = $_[1];
		674
		675	eval {
		676	local $SIG{__DIE__};
		677	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		678	if $_[0]{fh};
		679	};
		680	}
		681
		682	=item $handle->keepalive ($boolean)
		683
		684	Enables or disables the C<keepalive> setting (see constructor argument of
		685	the same name for details).
		686
		687	=cut
		688
		689	sub keepalive {
		690	$_[0]{keepalive} = $_[1];
		691
		692	eval {
		693	local $SIG{__DIE__};
		694	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		695	if $_[0]{fh};
		696	};
		697	}
		698
		699	=item $handle->on_starttls ($cb)
		700
		701	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		702
		703	=cut
		704
		705	sub on_starttls {
		706	$_[0]{on_starttls} = $_[1];
		707	}
		708
		709	=item $handle->on_stoptls ($cb)
		710
		711	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		712
		713	=cut
		714
		715	sub on_stoptls {
		716	$_[0]{on_stoptls} = $_[1];
		717	}
		718
		719	=item $handle->rbuf_max ($max_octets)
		720
		721	Configures the C<rbuf_max> setting (C<undef> disables it).
		722
		723	=cut
		724
		725	sub rbuf_max {
		726	$_[0]{rbuf_max} = $_[1];
		727	}
		728
		729	#############################################################################
		730
		731	=item $handle->timeout ($seconds)
		732
		733	=item $handle->rtimeout ($seconds)
		734
		735	=item $handle->wtimeout ($seconds)
		736
		737	Configures (or disables) the inactivity timeout.
		738
		739	=item $handle->timeout_reset
		740
		741	=item $handle->rtimeout_reset
		742
		743	=item $handle->wtimeout_reset
		744
		745	Reset the activity timeout, as if data was received or sent.
		746
		747	These methods are cheap to call.
		748
		749	=cut
		750
		751	for my $dir ("", "r", "w") {
		752	my $timeout = "${dir}timeout";
		753	my $tw = "_${dir}tw";
		754	my $on_timeout = "on_${dir}timeout";
		755	my $activity = "_${dir}activity";
		756	my $cb;
		757
		758	*$on_timeout = sub {
		759	$_[0]{$on_timeout} = $_[1];
		760	};
		761
		762	*$timeout = sub {
		763	my ($self, $new_value) = @_;
		764
		765	$self->{$timeout} = $new_value;
		766	delete $self->{$tw}; &$cb;
		767	};
		768
		769	*{"${dir}timeout_reset"} = sub {
		770	$_[0]{$activity} = AE::now;
		771	};
		772
		773	# main workhorse:
		774	# reset the timeout watcher, as neccessary
		775	# also check for time-outs
		776	$cb = sub {
		777	my ($self) = @_;
		778
		779	if ($self->{$timeout} && $self->{fh}) {
		780	my $NOW = AE::now;
		781
		782	# when would the timeout trigger?
		783	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
		784
		785	# now or in the past already?
		786	if ($after <= 0) {
		787	$self->{$activity} = $NOW;
		788
		789	if ($self->{$on_timeout}) {
		790	$self->{$on_timeout}($self);
		791	} else {
		792	$self->_error (Errno::ETIMEDOUT);
		793	}
		794
		795	# callback could have changed timeout value, optimise
		796	return unless $self->{$timeout};
		797
		798	# calculate new after
		799	$after = $self->{$timeout};
		800	}
		801
		802	Scalar::Util::weaken $self;
		803	return unless $self; # ->error could have destroyed $self
		804
		805	$self->{$tw} ||= AE::timer $after, 0, sub {
		806	delete $self->{$tw};
		807	$cb->($self);
		808	};
		809	} else {
		810	delete $self->{$tw};
		811	}
		812	}
		813	}
		814
		815	#############################################################################
		816
		817	=back
		818
		819	=head2 WRITE QUEUE
		820
		821	AnyEvent::Handle manages two queues per handle, one for writing and one
		822	for reading.
		823
		824	The write queue is very simple: you can add data to its end, and
		825	AnyEvent::Handle will automatically try to get rid of it for you.
		826
		827	When data could be written and the write buffer is shorter then the low
		828	water mark, the C<on_drain> callback will be invoked.
		829
		830	=over 4
		831
207	=item $handle->on_drain ($cb)	832	=item $handle->on_drain ($cb)
208		833
209	Sets the C<on_drain> callback or clears it (see the description of	834	Sets the C<on_drain> callback or clears it (see the description of
210	C<on_drain> in the constructor).	835	C<on_drain> in the constructor).
211		836
…		…
215	my ($self, $cb) = @_;	840	my ($self, $cb) = @_;
216		841
217	$self->{on_drain} = $cb;	842	$self->{on_drain} = $cb;
218		843
219	$cb->($self)	844	$cb->($self)
220	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	845	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
221	}	846	}
222		847
223	=item $handle->push_write ($data)	848	=item $handle->push_write ($data)
224		849
225	Queues the given scalar to be written. You can push as much data as you	850	Queues the given scalar to be written. You can push as much data as you
226	want (only limited by the available memory), as C<AnyEvent::Handle>	851	want (only limited by the available memory), as C<AnyEvent::Handle>
227	buffers it independently of the kernel.	852	buffers it independently of the kernel.
228		853
229	=cut	854	=cut
230		855
231	sub push_write {	856	sub _drain_wbuf {
232	my ($self, $data) = @_;	857	my ($self) = @_;
233		858
234	$self->{wbuf} .= $data;	859	if (!$self->{_ww} && length $self->{wbuf}) {
235		860
236	unless ($self->{ww}) {
237	Scalar::Util::weaken $self;	861	Scalar::Util::weaken $self;
		862
238	my $cb = sub {	863	my $cb = sub {
239	my $len = syswrite $self->{fh}, $self->{wbuf};	864	my $len = syswrite $self->{fh}, $self->{wbuf};
240		865
241	if ($len > 0) {	866	if (defined $len) {
242	substr $self->{wbuf}, 0, $len, "";	867	substr $self->{wbuf}, 0, $len, "";
243		868
		869	$self->{_activity} = $self->{_wactivity} = AE::now;
244		870
245	$self->{on_drain}($self)	871	$self->{on_drain}($self)
246	if $self->{low_water_mark} >= length $self->{wbuf}	872	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
247	&& $self->{on_drain};	873	&& $self->{on_drain};
248		874
249	delete $self->{ww} unless length $self->{wbuf};	875	delete $self->{_ww} unless length $self->{wbuf};
250	} elsif ($! != EAGAIN && $! != EINTR) {	876	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
251	$self->error;	877	$self->_error ($!, 1);
252	}	878	}
253	};	879	};
254		880
255	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	881	# try to write data immediately
		882	$cb->() unless $self->{autocork};
256		883
257	$cb->($self);	884	# if still data left in wbuf, we need to poll
		885	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		886	if length $self->{wbuf};
258	};	887	};
259	}	888	}
260		889
		890	our %WH;
		891
		892	# deprecated
		893	sub register_write_type($$) {
		894	$WH{$_[0]} = $_[1];
		895	}
		896
		897	sub push_write {
		898	my $self = shift;
		899
		900	if (@_ > 1) {
		901	my $type = shift;
		902
		903	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		904	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		905	->($self, @_);
		906	}
		907
		908	# we downgrade here to avoid hard-to-track-down bugs,
		909	# and diagnose the problem earlier and better.
		910
		911	if ($self->{tls}) {
		912	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		913	&_dotls ($self) if $self->{fh};
		914	} else {
		915	utf8::downgrade $self->{wbuf} .= $_[0];
		916	$self->_drain_wbuf if $self->{fh};
		917	}
		918	}
		919
		920	=item $handle->push_write (type => @args)
		921
		922	Instead of formatting your data yourself, you can also let this module
		923	do the job by specifying a type and type-specific arguments. You
		924	can also specify the (fully qualified) name of a package, in which
		925	case AnyEvent tries to load the package and then expects to find the
		926	C<anyevent_read_type> function inside (see "custom write types", below).
		927
		928	Predefined types are (if you have ideas for additional types, feel free to
		929	drop by and tell us):
		930
		931	=over 4
		932
		933	=item netstring => $string
		934
		935	Formats the given value as netstring
		936	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		937
		938	=cut
		939
		940	register_write_type netstring => sub {
		941	my ($self, $string) = @_;
		942
		943	(length $string) . ":$string,"
		944	};
		945
		946	=item packstring => $format, $data
		947
		948	An octet string prefixed with an encoded length. The encoding C<$format>
		949	uses the same format as a Perl C<pack> format, but must specify a single
		950	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		951	optional C<!>, C<< < >> or C<< > >> modifier).
		952
		953	=cut
		954
		955	register_write_type packstring => sub {
		956	my ($self, $format, $string) = @_;
		957
		958	pack "$format/a*", $string
		959	};
		960
		961	=item json => $array_or_hashref
		962
		963	Encodes the given hash or array reference into a JSON object. Unless you
		964	provide your own JSON object, this means it will be encoded to JSON text
		965	in UTF-8.
		966
		967	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		968	one end of a handle and read them at the other end without using any
		969	additional framing.
		970
		971	The generated JSON text is guaranteed not to contain any newlines: While
		972	this module doesn't need delimiters after or between JSON texts to be
		973	able to read them, many other languages depend on that.
		974
		975	A simple RPC protocol that interoperates easily with others is to send
		976	JSON arrays (or objects, although arrays are usually the better choice as
		977	they mimic how function argument passing works) and a newline after each
		978	JSON text:
		979
		980	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		981	$handle->push_write ("\012");
		982
		983	An AnyEvent::Handle receiver would simply use the C<json> read type and
		984	rely on the fact that the newline will be skipped as leading whitespace:
		985
		986	$handle->push_read (json => sub { my $array = $_[1]; ... });
		987
		988	Other languages could read single lines terminated by a newline and pass
		989	this line into their JSON decoder of choice.
		990
		991	=cut
		992
		993	sub json_coder() {
		994	eval { require JSON::XS; JSON::XS->new->utf8 }
		995	|| do { require JSON; JSON->new->utf8 }
		996	}
		997
		998	register_write_type json => sub {
		999	my ($self, $ref) = @_;
		1000
		1001	my $json = $self->{json} ||= json_coder;
		1002
		1003	$json->encode ($ref)
		1004	};
		1005
		1006	=item storable => $reference
		1007
		1008	Freezes the given reference using L<Storable> and writes it to the
		1009	handle. Uses the C<nfreeze> format.
		1010
		1011	=cut
		1012
		1013	register_write_type storable => sub {
		1014	my ($self, $ref) = @_;
		1015
		1016	require Storable;
		1017
		1018	pack "w/a*", Storable::nfreeze ($ref)
		1019	};
		1020
		1021	=back
		1022
		1023	=item $handle->push_shutdown
		1024
		1025	Sometimes you know you want to close the socket after writing your data
		1026	before it was actually written. One way to do that is to replace your
		1027	C<on_drain> handler by a callback that shuts down the socket (and set
		1028	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1029	replaces the C<on_drain> callback with:
		1030
		1031	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1032
		1033	This simply shuts down the write side and signals an EOF condition to the
		1034	the peer.
		1035
		1036	You can rely on the normal read queue and C<on_eof> handling
		1037	afterwards. This is the cleanest way to close a connection.
		1038
		1039	=cut
		1040
		1041	sub push_shutdown {
		1042	my ($self) = @_;
		1043
		1044	delete $self->{low_water_mark};
		1045	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1046	}
		1047
		1048	=item custom write types - Package::anyevent_write_type $handle, @args
		1049
		1050	Instead of one of the predefined types, you can also specify the name of
		1051	a package. AnyEvent will try to load the package and then expects to find
		1052	a function named C<anyevent_write_type> inside. If it isn't found, it
		1053	progressively tries to load the parent package until it either finds the
		1054	function (good) or runs out of packages (bad).
		1055
		1056	Whenever the given C<type> is used, C<push_write> will the function with
		1057	the handle object and the remaining arguments.
		1058
		1059	The function is supposed to return a single octet string that will be
		1060	appended to the write buffer, so you cna mentally treat this function as a
		1061	"arguments to on-the-wire-format" converter.
		1062
		1063	Example: implement a custom write type C<join> that joins the remaining
		1064	arguments using the first one.
		1065
		1066	$handle->push_write (My::Type => " ", 1,2,3);
		1067
		1068	# uses the following package, which can be defined in the "My::Type" or in
		1069	# the "My" modules to be auto-loaded, or just about anywhere when the
		1070	# My::Type::anyevent_write_type is defined before invoking it.
		1071
		1072	package My::Type;
		1073
		1074	sub anyevent_write_type {
		1075	my ($handle, $delim, @args) = @_;
		1076
		1077	join $delim, @args
		1078	}
		1079
		1080	=cut
		1081
261	#############################################################################	1082	#############################################################################
		1083
		1084	=back
		1085
		1086	=head2 READ QUEUE
		1087
		1088	AnyEvent::Handle manages two queues per handle, one for writing and one
		1089	for reading.
		1090
		1091	The read queue is more complex than the write queue. It can be used in two
		1092	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		1093	a queue.
		1094
		1095	In the simple case, you just install an C<on_read> callback and whenever
		1096	new data arrives, it will be called. You can then remove some data (if
		1097	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		1098	leave the data there if you want to accumulate more (e.g. when only a
		1099	partial message has been received so far).
		1100
		1101	In the more complex case, you want to queue multiple callbacks. In this
		1102	case, AnyEvent::Handle will call the first queued callback each time new
		1103	data arrives (also the first time it is queued) and removes it when it has
		1104	done its job (see C<push_read>, below).
		1105
		1106	This way you can, for example, push three line-reads, followed by reading
		1107	a chunk of data, and AnyEvent::Handle will execute them in order.
		1108
		1109	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		1110	the specified number of bytes which give an XML datagram.
		1111
		1112	# in the default state, expect some header bytes
		1113	$handle->on_read (sub {
		1114	# some data is here, now queue the length-header-read (4 octets)
		1115	shift->unshift_read (chunk => 4, sub {
		1116	# header arrived, decode
		1117	my $len = unpack "N", $_[1];
		1118
		1119	# now read the payload
		1120	shift->unshift_read (chunk => $len, sub {
		1121	my $xml = $_[1];
		1122	# handle xml
		1123	});
		1124	});
		1125	});
		1126
		1127	Example 2: Implement a client for a protocol that replies either with "OK"
		1128	and another line or "ERROR" for the first request that is sent, and 64
		1129	bytes for the second request. Due to the availability of a queue, we can
		1130	just pipeline sending both requests and manipulate the queue as necessary
		1131	in the callbacks.
		1132
		1133	When the first callback is called and sees an "OK" response, it will
		1134	C<unshift> another line-read. This line-read will be queued I<before> the
		1135	64-byte chunk callback.
		1136
		1137	# request one, returns either "OK + extra line" or "ERROR"
		1138	$handle->push_write ("request 1\015\012");
		1139
		1140	# we expect "ERROR" or "OK" as response, so push a line read
		1141	$handle->push_read (line => sub {
		1142	# if we got an "OK", we have to _prepend_ another line,
		1143	# so it will be read before the second request reads its 64 bytes
		1144	# which are already in the queue when this callback is called
		1145	# we don't do this in case we got an error
		1146	if ($_[1] eq "OK") {
		1147	$_[0]->unshift_read (line => sub {
		1148	my $response = $_[1];
		1149	...
		1150	});
		1151	}
		1152	});
		1153
		1154	# request two, simply returns 64 octets
		1155	$handle->push_write ("request 2\015\012");
		1156
		1157	# simply read 64 bytes, always
		1158	$handle->push_read (chunk => 64, sub {
		1159	my $response = $_[1];
		1160	...
		1161	});
		1162
		1163	=over 4
		1164
		1165	=cut
262		1166
263	sub _drain_rbuf {	1167	sub _drain_rbuf {
264	my ($self) = @_;	1168	my ($self) = @_;
265		1169
		1170	# avoid recursion
266	return if exists $self->{in_drain};	1171	return if $self->{_skip_drain_rbuf};
267	local $self->{in_drain} = 1;	1172	local $self->{_skip_drain_rbuf} = 1;
268		1173
		1174	while () {
		1175	# we need to use a separate tls read buffer, as we must not receive data while
		1176	# we are draining the buffer, and this can only happen with TLS.
		1177	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1178	if exists $self->{_tls_rbuf};
		1179
269	while (my $len = length $self->{rbuf}) {	1180	my $len = length $self->{rbuf};
270	no strict 'refs';	1181
271	if (@{ $self->{queue} }) {	1182	if (my $cb = shift @{ $self->{_queue} }) {
272	if ($self->{queue}[0]($self)) {	1183	unless ($cb->($self)) {
		1184	# no progress can be made
		1185	# (not enough data and no data forthcoming)
		1186	$self->_error (Errno::EPIPE, 1), return
		1187	if $self->{_eof};
		1188
273	shift @{ $self->{queue} };	1189	unshift @{ $self->{_queue} }, $cb;
274	} elsif ($self->{eof}) {
275	# no progress can be made (not enough data and no data forthcoming)
276	$! = &Errno::EPIPE; return $self->error;
277	} else {
278	return;	1190	last;
279	}	1191	}
280	} elsif ($self->{on_read}) {	1192	} elsif ($self->{on_read}) {
		1193	last unless $len;
		1194
281	$self->{on_read}($self);	1195	$self->{on_read}($self);
282		1196
283	if (	1197	if (
284	$self->{eof} # if no further data will arrive
285	&& $len == length $self->{rbuf} # and no data has been consumed	1198	$len == length $self->{rbuf} # if no data has been consumed
286	&& !@{ $self->{queue} } # and the queue is still empty	1199	&& !@{ $self->{_queue} } # and the queue is still empty
287	&& $self->{on_read} # and we still want to read data	1200	&& $self->{on_read} # but we still have on_read
288	) {	1201	) {
		1202	# no further data will arrive
289	# then no progress can be made	1203	# so no progress can be made
290	$! = &Errno::EPIPE; return $self->error;	1204	$self->_error (Errno::EPIPE, 1), return
		1205	if $self->{_eof};
		1206
		1207	last; # more data might arrive
291	}	1208	}
292	} else {	1209	} else {
293	# read side becomes idle	1210	# read side becomes idle
294	delete $self->{rw};	1211	delete $self->{_rw} unless $self->{tls};
295	return;	1212	last;
296	}	1213	}
297	}	1214	}
298		1215
299	if ($self->{eof}) {	1216	if ($self->{_eof}) {
300	$self->_shutdown;	1217	$self->{on_eof}
301	$self->{on_eof}($self);	1218	? $self->{on_eof}($self)
		1219	: $self->_error (0, 1, "Unexpected end-of-file");
		1220
		1221	return;
		1222	}
		1223
		1224	if (
		1225	defined $self->{rbuf_max}
		1226	&& $self->{rbuf_max} < length $self->{rbuf}
		1227	) {
		1228	$self->_error (Errno::ENOSPC, 1), return;
		1229	}
		1230
		1231	# may need to restart read watcher
		1232	unless ($self->{_rw}) {
		1233	$self->start_read
		1234	if $self->{on_read} || @{ $self->{_queue} };
302	}	1235	}
303	}	1236	}
304		1237
305	=item $handle->on_read ($cb)	1238	=item $handle->on_read ($cb)
306		1239
…		…
312		1245
313	sub on_read {	1246	sub on_read {
314	my ($self, $cb) = @_;	1247	my ($self, $cb) = @_;
315		1248
316	$self->{on_read} = $cb;	1249	$self->{on_read} = $cb;
317
318	unless ($self->{rw} || $self->{eof}) {
319	Scalar::Util::weaken $self;
320
321	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
322	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};
323
324	if ($len > 0) {
325	if (exists $self->{rbuf_max}) {
326	if ($self->{rbuf_max} < length $self->{rbuf}) {
327	$! = &Errno::ENOSPC; return $self->error;
328	}
329	}
330
331	} elsif (defined $len) {
332	$self->{eof} = 1;
333	delete $self->{rw};
334
335	} elsif ($! != EAGAIN && $! != EINTR) {
336	return $self->error;
337	}
338
339	$self->_drain_rbuf;	1250	$self->_drain_rbuf if $cb;
340	});
341	}
342	}	1251	}
343		1252
344	=item $handle->rbuf	1253	=item $handle->rbuf
345		1254
346	Returns the read buffer (as a modifiable lvalue).	1255	Returns the read buffer (as a modifiable lvalue).
347		1256
348	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1257	You can access the read buffer directly as the C<< ->{rbuf} >>
349	you want.	1258	member, if you want. However, the only operation allowed on the
		1259	read buffer (apart from looking at it) is removing data from its
		1260	beginning. Otherwise modifying or appending to it is not allowed and will
		1261	lead to hard-to-track-down bugs.
350		1262
351	NOTE: The read buffer should only be used or modified if the C<on_read>,	1263	NOTE: The read buffer should only be used or modified if the C<on_read>,
352	C<push_read> or C<unshift_read> methods are used. The other read methods	1264	C<push_read> or C<unshift_read> methods are used. The other read methods
353	automatically manage the read buffer.	1265	automatically manage the read buffer.
354		1266
…		…
365	Append the given callback to the end of the queue (C<push_read>) or	1277	Append the given callback to the end of the queue (C<push_read>) or
366	prepend it (C<unshift_read>).	1278	prepend it (C<unshift_read>).
367		1279
368	The callback is called each time some additional read data arrives.	1280	The callback is called each time some additional read data arrives.
369		1281
370	It must check wether enough data is in the read buffer already.	1282	It must check whether enough data is in the read buffer already.
371		1283
372	If not enough data is available, it must return the empty list or a false	1284	If not enough data is available, it must return the empty list or a false
373	value, in which case it will be called repeatedly until enough data is	1285	value, in which case it will be called repeatedly until enough data is
374	available (or an error condition is detected).	1286	available (or an error condition is detected).
375		1287
…		…
377	interested in (which can be none at all) and return a true value. After returning	1289	interested in (which can be none at all) and return a true value. After returning
378	true, it will be removed from the queue.	1290	true, it will be removed from the queue.
379		1291
380	=cut	1292	=cut
381		1293
		1294	our %RH;
		1295
		1296	sub register_read_type($$) {
		1297	$RH{$_[0]} = $_[1];
		1298	}
		1299
382	sub push_read {	1300	sub push_read {
383	my ($self, $cb) = @_;	1301	my $self = shift;
		1302	my $cb = pop;
384		1303
		1304	if (@_) {
		1305	my $type = shift;
		1306
		1307	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1308	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1309	->($self, $cb, @_);
		1310	}
		1311
385	push @{ $self->{queue} }, $cb;	1312	push @{ $self->{_queue} }, $cb;
386	$self->_drain_rbuf;	1313	$self->_drain_rbuf;
387	}	1314	}
388		1315
389	sub unshift_read {	1316	sub unshift_read {
390	my ($self, $cb) = @_;	1317	my $self = shift;
		1318	my $cb = pop;
391		1319
		1320	if (@_) {
		1321	my $type = shift;
		1322
		1323	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1324	->($self, $cb, @_);
		1325	}
		1326
392	push @{ $self->{queue} }, $cb;	1327	unshift @{ $self->{_queue} }, $cb;
393	$self->_drain_rbuf;	1328	$self->_drain_rbuf;
394	}	1329	}
395		1330
396	=item $handle->push_read_chunk ($len, $cb->($self, $data))	1331	=item $handle->push_read (type => @args, $cb)
397		1332
398	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	1333	=item $handle->unshift_read (type => @args, $cb)
399		1334
400	Append the given callback to the end of the queue (C<push_read_chunk>) or	1335	Instead of providing a callback that parses the data itself you can chose
401	prepend it (C<unshift_read_chunk>).	1336	between a number of predefined parsing formats, for chunks of data, lines
		1337	etc. You can also specify the (fully qualified) name of a package, in
		1338	which case AnyEvent tries to load the package and then expects to find the
		1339	C<anyevent_read_type> function inside (see "custom read types", below).
402		1340
403	The callback will be called only once C<$len> bytes have been read, and	1341	Predefined types are (if you have ideas for additional types, feel free to
404	these C<$len> bytes will be passed to the callback.	1342	drop by and tell us):
405		1343
406	=cut	1344	=over 4
407		1345
408	sub _read_chunk($$) {	1346	=item chunk => $octets, $cb->($handle, $data)
409	my ($len, $cb) = @_;	1347
		1348	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1349	data read to the callback. The callback will never be called with less
		1350	data.
		1351
		1352	Example: read 2 bytes.
		1353
		1354	$handle->push_read (chunk => 2, sub {
		1355	warn "yay ", unpack "H*", $_[1];
		1356	});
		1357
		1358	=cut
		1359
		1360	register_read_type chunk => sub {
		1361	my ($self, $cb, $len) = @_;
410		1362
411	sub {	1363	sub {
412	$len <= length $_[0]{rbuf} or return;	1364	$len <= length $_[0]{rbuf} or return;
413	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1365	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
414	1	1366	1
415	}	1367	}
416	}	1368	};
417		1369
418	sub push_read_chunk {	1370	=item line => [$eol, ]$cb->($handle, $line, $eol)
419	my ($self, $len, $cb) = @_;
420
421	$self->push_read (_read_chunk $len, $cb);
422	}
423
424
425	sub unshift_read_chunk {
426	my ($self, $len, $cb) = @_;
427
428	$self->unshift_read (_read_chunk $len, $cb);
429	}
430
431	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
432
433	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
434
435	Append the given callback to the end of the queue (C<push_read_line>) or
436	prepend it (C<unshift_read_line>).
437		1371
438	The callback will be called only once a full line (including the end of	1372	The callback will be called only once a full line (including the end of
439	line marker, C<$eol>) has been read. This line (excluding the end of line	1373	line marker, C<$eol>) has been read. This line (excluding the end of line
440	marker) will be passed to the callback as second argument (C<$line>), and	1374	marker) will be passed to the callback as second argument (C<$line>), and
441	the end of line marker as the third argument (C<$eol>).	1375	the end of line marker as the third argument (C<$eol>).
…		…
452	Partial lines at the end of the stream will never be returned, as they are	1386	Partial lines at the end of the stream will never be returned, as they are
453	not marked by the end of line marker.	1387	not marked by the end of line marker.
454		1388
455	=cut	1389	=cut
456		1390
457	sub _read_line($$) {	1391	register_read_type line => sub {
458	my $cb = pop;	1392	my ($self, $cb, $eol) = @_;
459	my $eol = @_ ? shift : qr|(\015?\012)|;
460	my $pos;
461		1393
		1394	if (@_ < 3) {
		1395	# this is more than twice as fast as the generic code below
		1396	sub {
		1397	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1398
		1399	$cb->($_[0], $1, $2);
		1400	1
		1401	}
		1402	} else {
462	$eol = qr|(\Q$eol\E)| unless ref $eol;	1403	$eol = quotemeta $eol unless ref $eol;
463	$eol = qr|^(.*?)($eol)|;	1404	$eol = qr|^(.*?)($eol)|s;
		1405
		1406	sub {
		1407	$_[0]{rbuf} =~ s/$eol// or return;
		1408
		1409	$cb->($_[0], $1, $2);
		1410	1
		1411	}
		1412	}
		1413	};
		1414
		1415	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1416
		1417	Makes a regex match against the regex object C<$accept> and returns
		1418	everything up to and including the match.
		1419
		1420	Example: read a single line terminated by '\n'.
		1421
		1422	$handle->push_read (regex => qr<\n>, sub { ... });
		1423
		1424	If C<$reject> is given and not undef, then it determines when the data is
		1425	to be rejected: it is matched against the data when the C<$accept> regex
		1426	does not match and generates an C<EBADMSG> error when it matches. This is
		1427	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1428	receive buffer overflow).
		1429
		1430	Example: expect a single decimal number followed by whitespace, reject
		1431	anything else (not the use of an anchor).
		1432
		1433	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1434
		1435	If C<$skip> is given and not C<undef>, then it will be matched against
		1436	the receive buffer when neither C<$accept> nor C<$reject> match,
		1437	and everything preceding and including the match will be accepted
		1438	unconditionally. This is useful to skip large amounts of data that you
		1439	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1440	have to start matching from the beginning. This is purely an optimisation
		1441	and is usually worth only when you expect more than a few kilobytes.
		1442
		1443	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1444	expect the header to be very large (it isn't in practise, but...), we use
		1445	a skip regex to skip initial portions. The skip regex is tricky in that
		1446	it only accepts something not ending in either \015 or \012, as these are
		1447	required for the accept regex.
		1448
		1449	$handle->push_read (regex =>
		1450	qr<\015\012\015\012>,
		1451	undef, # no reject
		1452	qr<^.*[^\015\012]>,
		1453	sub { ... });
		1454
		1455	=cut
		1456
		1457	register_read_type regex => sub {
		1458	my ($self, $cb, $accept, $reject, $skip) = @_;
		1459
		1460	my $data;
		1461	my $rbuf = \$self->{rbuf};
464		1462
465	sub {	1463	sub {
466	$_[0]{rbuf} =~ s/$eol// or return;	1464	# accept
		1465	if ($$rbuf =~ $accept) {
		1466	$data .= substr $$rbuf, 0, $+[0], "";
		1467	$cb->($self, $data);
		1468	return 1;
		1469	}
		1470
		1471	# reject
		1472	if ($reject && $$rbuf =~ $reject) {
		1473	$self->_error (Errno::EBADMSG);
		1474	}
467		1475
468	$cb->($1, $2);	1476	# skip
		1477	if ($skip && $$rbuf =~ $skip) {
		1478	$data .= substr $$rbuf, 0, $+[0], "";
		1479	}
		1480
		1481	()
		1482	}
		1483	};
		1484
		1485	=item netstring => $cb->($handle, $string)
		1486
		1487	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1488
		1489	Throws an error with C<$!> set to EBADMSG on format violations.
		1490
		1491	=cut
		1492
		1493	register_read_type netstring => sub {
		1494	my ($self, $cb) = @_;
		1495
		1496	sub {
		1497	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1498	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1499	$self->_error (Errno::EBADMSG);
		1500	}
		1501	return;
		1502	}
		1503
		1504	my $len = $1;
		1505
		1506	$self->unshift_read (chunk => $len, sub {
		1507	my $string = $_[1];
		1508	$_[0]->unshift_read (chunk => 1, sub {
		1509	if ($_[1] eq ",") {
		1510	$cb->($_[0], $string);
		1511	} else {
		1512	$self->_error (Errno::EBADMSG);
		1513	}
		1514	});
		1515	});
		1516
469	1	1517	1
470	}	1518	}
471	}	1519	};
472		1520
473	sub push_read_line {	1521	=item packstring => $format, $cb->($handle, $string)
474	my $self = shift;
475		1522
476	$self->push_read (&_read_line);	1523	An octet string prefixed with an encoded length. The encoding C<$format>
477	}	1524	uses the same format as a Perl C<pack> format, but must specify a single
		1525	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1526	optional C<!>, C<< < >> or C<< > >> modifier).
478		1527
479	sub unshift_read_line {	1528	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
480	my $self = shift;	1529	EPP uses a prefix of C<N> (4 octtes).
481		1530
482	$self->unshift_read (&_read_line);	1531	Example: read a block of data prefixed by its length in BER-encoded
483	}	1532	format (very efficient).
		1533
		1534	$handle->push_read (packstring => "w", sub {
		1535	my ($handle, $data) = @_;
		1536	});
		1537
		1538	=cut
		1539
		1540	register_read_type packstring => sub {
		1541	my ($self, $cb, $format) = @_;
		1542
		1543	sub {
		1544	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1545	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1546	or return;
		1547
		1548	$format = length pack $format, $len;
		1549
		1550	# bypass unshift if we already have the remaining chunk
		1551	if ($format + $len <= length $_[0]{rbuf}) {
		1552	my $data = substr $_[0]{rbuf}, $format, $len;
		1553	substr $_[0]{rbuf}, 0, $format + $len, "";
		1554	$cb->($_[0], $data);
		1555	} else {
		1556	# remove prefix
		1557	substr $_[0]{rbuf}, 0, $format, "";
		1558
		1559	# read remaining chunk
		1560	$_[0]->unshift_read (chunk => $len, $cb);
		1561	}
		1562
		1563	1
		1564	}
		1565	};
		1566
		1567	=item json => $cb->($handle, $hash_or_arrayref)
		1568
		1569	Reads a JSON object or array, decodes it and passes it to the
		1570	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1571
		1572	If a C<json> object was passed to the constructor, then that will be used
		1573	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1574
		1575	This read type uses the incremental parser available with JSON version
		1576	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1577	dependency on your own: this module will load the JSON module, but
		1578	AnyEvent does not depend on it itself.
		1579
		1580	Since JSON texts are fully self-delimiting, the C<json> read and write
		1581	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1582	the C<json> write type description, above, for an actual example.
		1583
		1584	=cut
		1585
		1586	register_read_type json => sub {
		1587	my ($self, $cb) = @_;
		1588
		1589	my $json = $self->{json} ||= json_coder;
		1590
		1591	my $data;
		1592	my $rbuf = \$self->{rbuf};
		1593
		1594	sub {
		1595	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1596
		1597	if ($ref) {
		1598	$self->{rbuf} = $json->incr_text;
		1599	$json->incr_text = "";
		1600	$cb->($self, $ref);
		1601
		1602	1
		1603	} elsif ($@) {
		1604	# error case
		1605	$json->incr_skip;
		1606
		1607	$self->{rbuf} = $json->incr_text;
		1608	$json->incr_text = "";
		1609
		1610	$self->_error (Errno::EBADMSG);
		1611
		1612	()
		1613	} else {
		1614	$self->{rbuf} = "";
		1615
		1616	()
		1617	}
		1618	}
		1619	};
		1620
		1621	=item storable => $cb->($handle, $ref)
		1622
		1623	Deserialises a L<Storable> frozen representation as written by the
		1624	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1625	data).
		1626
		1627	Raises C<EBADMSG> error if the data could not be decoded.
		1628
		1629	=cut
		1630
		1631	register_read_type storable => sub {
		1632	my ($self, $cb) = @_;
		1633
		1634	require Storable;
		1635
		1636	sub {
		1637	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1638	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1639	or return;
		1640
		1641	my $format = length pack "w", $len;
		1642
		1643	# bypass unshift if we already have the remaining chunk
		1644	if ($format + $len <= length $_[0]{rbuf}) {
		1645	my $data = substr $_[0]{rbuf}, $format, $len;
		1646	substr $_[0]{rbuf}, 0, $format + $len, "";
		1647	$cb->($_[0], Storable::thaw ($data));
		1648	} else {
		1649	# remove prefix
		1650	substr $_[0]{rbuf}, 0, $format, "";
		1651
		1652	# read remaining chunk
		1653	$_[0]->unshift_read (chunk => $len, sub {
		1654	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1655	$cb->($_[0], $ref);
		1656	} else {
		1657	$self->_error (Errno::EBADMSG);
		1658	}
		1659	});
		1660	}
		1661
		1662	1
		1663	}
		1664	};
484		1665
485	=back	1666	=back
486		1667
		1668	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1669
		1670	Instead of one of the predefined types, you can also specify the name
		1671	of a package. AnyEvent will try to load the package and then expects to
		1672	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1673	progressively tries to load the parent package until it either finds the
		1674	function (good) or runs out of packages (bad).
		1675
		1676	Whenever this type is used, C<push_read> will invoke the function with the
		1677	handle object, the original callback and the remaining arguments.
		1678
		1679	The function is supposed to return a callback (usually a closure) that
		1680	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1681	mentally treat the function as a "configurable read type to read callback"
		1682	converter.
		1683
		1684	It should invoke the original callback when it is done reading (remember
		1685	to pass C<$handle> as first argument as all other callbacks do that,
		1686	although there is no strict requirement on this).
		1687
		1688	For examples, see the source of this module (F<perldoc -m
		1689	AnyEvent::Handle>, search for C<register_read_type>)).
		1690
		1691	=item $handle->stop_read
		1692
		1693	=item $handle->start_read
		1694
		1695	In rare cases you actually do not want to read anything from the
		1696	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1697	any queued callbacks will be executed then. To start reading again, call
		1698	C<start_read>.
		1699
		1700	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1701	you change the C<on_read> callback or push/unshift a read callback, and it
		1702	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1703	there are any read requests in the queue.
		1704
		1705	These methods will have no effect when in TLS mode (as TLS doesn't support
		1706	half-duplex connections).
		1707
		1708	=cut
		1709
		1710	sub stop_read {
		1711	my ($self) = @_;
		1712
		1713	delete $self->{_rw} unless $self->{tls};
		1714	}
		1715
		1716	sub start_read {
		1717	my ($self) = @_;
		1718
		1719	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		1720	Scalar::Util::weaken $self;
		1721
		1722	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1723	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1724	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1725
		1726	if ($len > 0) {
		1727	$self->{_activity} = $self->{_ractivity} = AE::now;
		1728
		1729	if ($self->{tls}) {
		1730	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1731
		1732	&_dotls ($self);
		1733	} else {
		1734	$self->_drain_rbuf;
		1735	}
		1736
		1737	} elsif (defined $len) {
		1738	delete $self->{_rw};
		1739	$self->{_eof} = 1;
		1740	$self->_drain_rbuf;
		1741
		1742	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1743	return $self->_error ($!, 1);
		1744	}
		1745	};
		1746	}
		1747	}
		1748
		1749	our $ERROR_SYSCALL;
		1750	our $ERROR_WANT_READ;
		1751
		1752	sub _tls_error {
		1753	my ($self, $err) = @_;
		1754
		1755	return $self->_error ($!, 1)
		1756	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1757
		1758	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1759
		1760	# reduce error string to look less scary
		1761	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1762
		1763	if ($self->{_on_starttls}) {
		1764	(delete $self->{_on_starttls})->($self, undef, $err);
		1765	&_freetls;
		1766	} else {
		1767	&_freetls;
		1768	$self->_error (Errno::EPROTO, 1, $err);
		1769	}
		1770	}
		1771
		1772	# poll the write BIO and send the data if applicable
		1773	# also decode read data if possible
		1774	# this is basiclaly our TLS state machine
		1775	# more efficient implementations are possible with openssl,
		1776	# but not with the buggy and incomplete Net::SSLeay.
		1777	sub _dotls {
		1778	my ($self) = @_;
		1779
		1780	my $tmp;
		1781
		1782	if (length $self->{_tls_wbuf}) {
		1783	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1784	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1785	}
		1786
		1787	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1788	return $self->_tls_error ($tmp)
		1789	if $tmp != $ERROR_WANT_READ
		1790	&& ($tmp != $ERROR_SYSCALL || $!);
		1791	}
		1792
		1793	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1794	unless (length $tmp) {
		1795	$self->{_on_starttls}
		1796	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1797	&_freetls;
		1798
		1799	if ($self->{on_stoptls}) {
		1800	$self->{on_stoptls}($self);
		1801	return;
		1802	} else {
		1803	# let's treat SSL-eof as we treat normal EOF
		1804	delete $self->{_rw};
		1805	$self->{_eof} = 1;
		1806	}
		1807	}
		1808
		1809	$self->{_tls_rbuf} .= $tmp;
		1810	$self->_drain_rbuf;
		1811	$self->{tls} or return; # tls session might have gone away in callback
		1812	}
		1813
		1814	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1815	return $self->_tls_error ($tmp)
		1816	if $tmp != $ERROR_WANT_READ
		1817	&& ($tmp != $ERROR_SYSCALL || $!);
		1818
		1819	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1820	$self->{wbuf} .= $tmp;
		1821	$self->_drain_wbuf;
		1822	$self->{tls} or return; # tls session might have gone away in callback
		1823	}
		1824
		1825	$self->{_on_starttls}
		1826	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1827	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1828	}
		1829
		1830	=item $handle->starttls ($tls[, $tls_ctx])
		1831
		1832	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1833	object is created, you can also do that at a later time by calling
		1834	C<starttls>.
		1835
		1836	Starting TLS is currently an asynchronous operation - when you push some
		1837	write data and then call C<< ->starttls >> then TLS negotiation will start
		1838	immediately, after which the queued write data is then sent.
		1839
		1840	The first argument is the same as the C<tls> constructor argument (either
		1841	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1842
		1843	The second argument is the optional C<AnyEvent::TLS> object that is used
		1844	when AnyEvent::Handle has to create its own TLS connection object, or
		1845	a hash reference with C<< key => value >> pairs that will be used to
		1846	construct a new context.
		1847
		1848	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1849	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1850	changed to your liking. Note that the handshake might have already started
		1851	when this function returns.
		1852
		1853	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1854	handshakes on the same stream. Best do not attempt to use the stream after
		1855	stopping TLS.
		1856
		1857	=cut
		1858
		1859	our %TLS_CACHE; #TODO not yet documented, should we?
		1860
		1861	sub starttls {
		1862	my ($self, $tls, $ctx) = @_;
		1863
		1864	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1865	if $self->{tls};
		1866
		1867	$self->{tls} = $tls;
		1868	$self->{tls_ctx} = $ctx if @_ > 2;
		1869
		1870	return unless $self->{fh};
		1871
		1872	require Net::SSLeay;
		1873
		1874	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1875	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1876
		1877	$tls = delete $self->{tls};
		1878	$ctx = $self->{tls_ctx};
		1879
		1880	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1881
		1882	if ("HASH" eq ref $ctx) {
		1883	require AnyEvent::TLS;
		1884
		1885	if ($ctx->{cache}) {
		1886	my $key = $ctx+0;
		1887	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1888	} else {
		1889	$ctx = new AnyEvent::TLS %$ctx;
		1890	}
		1891	}
		1892
		1893	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1894	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		1895
		1896	# basically, this is deep magic (because SSL_read should have the same issues)
		1897	# but the openssl maintainers basically said: "trust us, it just works".
		1898	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1899	# and mismaintained ssleay-module doesn't even offer them).
		1900	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1901	#
		1902	# in short: this is a mess.
		1903	#
		1904	# note that we do not try to keep the length constant between writes as we are required to do.
		1905	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1906	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1907	# have identity issues in that area.
		1908	# Net::SSLeay::CTX_set_mode ($ssl,
		1909	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1910	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1911	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		1912
		1913	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1914	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1915
		1916	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1917
		1918	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1919
		1920	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1921	if $self->{on_starttls};
		1922
		1923	&_dotls; # need to trigger the initial handshake
		1924	$self->start_read; # make sure we actually do read
		1925	}
		1926
		1927	=item $handle->stoptls
		1928
		1929	Shuts down the SSL connection - this makes a proper EOF handshake by
		1930	sending a close notify to the other side, but since OpenSSL doesn't
		1931	support non-blocking shut downs, it is not guaranteed that you can re-use
		1932	the stream afterwards.
		1933
		1934	=cut
		1935
		1936	sub stoptls {
		1937	my ($self) = @_;
		1938
		1939	if ($self->{tls} && $self->{fh}) {
		1940	Net::SSLeay::shutdown ($self->{tls});
		1941
		1942	&_dotls;
		1943
		1944	# # we don't give a shit. no, we do, but we can't. no...#d#
		1945	# # we, we... have to use openssl :/#d#
		1946	# &_freetls;#d#
		1947	}
		1948	}
		1949
		1950	sub _freetls {
		1951	my ($self) = @_;
		1952
		1953	return unless $self->{tls};
		1954
		1955	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1956	if $self->{tls} > 0;
		1957
		1958	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1959	}
		1960
		1961	sub DESTROY {
		1962	my ($self) = @_;
		1963
		1964	&_freetls;
		1965
		1966	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1967
		1968	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1969	my $fh = delete $self->{fh};
		1970	my $wbuf = delete $self->{wbuf};
		1971
		1972	my @linger;
		1973
		1974	push @linger, AE::io $fh, 1, sub {
		1975	my $len = syswrite $fh, $wbuf, length $wbuf;
		1976
		1977	if ($len > 0) {
		1978	substr $wbuf, 0, $len, "";
		1979	} else {
		1980	@linger = (); # end
		1981	}
		1982	};
		1983	push @linger, AE::timer $linger, 0, sub {
		1984	@linger = ();
		1985	};
		1986	}
		1987	}
		1988
		1989	=item $handle->destroy
		1990
		1991	Shuts down the handle object as much as possible - this call ensures that
		1992	no further callbacks will be invoked and as many resources as possible
		1993	will be freed. Any method you will call on the handle object after
		1994	destroying it in this way will be silently ignored (and it will return the
		1995	empty list).
		1996
		1997	Normally, you can just "forget" any references to an AnyEvent::Handle
		1998	object and it will simply shut down. This works in fatal error and EOF
		1999	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2000	callback, so when you want to destroy the AnyEvent::Handle object from
		2001	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2002	that case.
		2003
		2004	Destroying the handle object in this way has the advantage that callbacks
		2005	will be removed as well, so if those are the only reference holders (as
		2006	is common), then one doesn't need to do anything special to break any
		2007	reference cycles.
		2008
		2009	The handle might still linger in the background and write out remaining
		2010	data, as specified by the C<linger> option, however.
		2011
		2012	=cut
		2013
		2014	sub destroy {
		2015	my ($self) = @_;
		2016
		2017	$self->DESTROY;
		2018	%$self = ();
		2019	bless $self, "AnyEvent::Handle::destroyed";
		2020	}
		2021
		2022	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2023	#nop
		2024	}
		2025
		2026	=item $handle->destroyed
		2027
		2028	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2029	->destroy >>, true otherwise.
		2030
		2031	Can be useful to decide whether the handle is still valid after some
		2032	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2033	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2034	can destroy the handle, so work can be avoided by checking sometimes:
		2035
		2036	$hdl->starttls ("accept");
		2037	return if $hdl->destroyed;
		2038	$hdl->push_write (...
		2039
		2040	Note that the call to C<push_write> will silently be ignored if the handle
		2041	has been destroyed, so often you can just ignore the possibility of the
		2042	handle being destroyed.
		2043
		2044	=cut
		2045
		2046	sub destroyed { 0 }
		2047	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2048
		2049	=item AnyEvent::Handle::TLS_CTX
		2050
		2051	This function creates and returns the AnyEvent::TLS object used by default
		2052	for TLS mode.
		2053
		2054	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2055
		2056	=cut
		2057
		2058	our $TLS_CTX;
		2059
		2060	sub TLS_CTX() {
		2061	$TLS_CTX ||= do {
		2062	require AnyEvent::TLS;
		2063
		2064	new AnyEvent::TLS
		2065	}
		2066	}
		2067
		2068	=back
		2069
		2070
		2071	=head1 NONFREQUENTLY ASKED QUESTIONS
		2072
		2073	=over 4
		2074
		2075	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2076	still get further invocations!
		2077
		2078	That's because AnyEvent::Handle keeps a reference to itself when handling
		2079	read or write callbacks.
		2080
		2081	It is only safe to "forget" the reference inside EOF or error callbacks,
		2082	from within all other callbacks, you need to explicitly call the C<<
		2083	->destroy >> method.
		2084
		2085	=item I get different callback invocations in TLS mode/Why can't I pause
		2086	reading?
		2087
		2088	Unlike, say, TCP, TLS connections do not consist of two independent
		2089	communication channels, one for each direction. Or put differently. The
		2090	read and write directions are not independent of each other: you cannot
		2091	write data unless you are also prepared to read, and vice versa.
		2092
		2093	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2094	callback invocations when you are not expecting any read data - the reason
		2095	is that AnyEvent::Handle always reads in TLS mode.
		2096
		2097	During the connection, you have to make sure that you always have a
		2098	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2099	connection (or when you no longer want to use it) you can call the
		2100	C<destroy> method.
		2101
		2102	=item How do I read data until the other side closes the connection?
		2103
		2104	If you just want to read your data into a perl scalar, the easiest way
		2105	to achieve this is by setting an C<on_read> callback that does nothing,
		2106	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2107	will be in C<$_[0]{rbuf}>:
		2108
		2109	$handle->on_read (sub { });
		2110	$handle->on_eof (undef);
		2111	$handle->on_error (sub {
		2112	my $data = delete $_[0]{rbuf};
		2113	});
		2114
		2115	The reason to use C<on_error> is that TCP connections, due to latencies
		2116	and packets loss, might get closed quite violently with an error, when in
		2117	fact, all data has been received.
		2118
		2119	It is usually better to use acknowledgements when transferring data,
		2120	to make sure the other side hasn't just died and you got the data
		2121	intact. This is also one reason why so many internet protocols have an
		2122	explicit QUIT command.
		2123
		2124	=item I don't want to destroy the handle too early - how do I wait until
		2125	all data has been written?
		2126
		2127	After writing your last bits of data, set the C<on_drain> callback
		2128	and destroy the handle in there - with the default setting of
		2129	C<low_water_mark> this will be called precisely when all data has been
		2130	written to the socket:
		2131
		2132	$handle->push_write (...);
		2133	$handle->on_drain (sub {
		2134	warn "all data submitted to the kernel\n";
		2135	undef $handle;
		2136	});
		2137
		2138	If you just want to queue some data and then signal EOF to the other side,
		2139	consider using C<< ->push_shutdown >> instead.
		2140
		2141	=item I want to contact a TLS/SSL server, I don't care about security.
		2142
		2143	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2144	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2145	parameter:
		2146
		2147	tcp_connect $host, $port, sub {
		2148	my ($fh) = @_;
		2149
		2150	my $handle = new AnyEvent::Handle
		2151	fh => $fh,
		2152	tls => "connect",
		2153	on_error => sub { ... };
		2154
		2155	$handle->push_write (...);
		2156	};
		2157
		2158	=item I want to contact a TLS/SSL server, I do care about security.
		2159
		2160	Then you should additionally enable certificate verification, including
		2161	peername verification, if the protocol you use supports it (see
		2162	L<AnyEvent::TLS>, C<verify_peername>).
		2163
		2164	E.g. for HTTPS:
		2165
		2166	tcp_connect $host, $port, sub {
		2167	my ($fh) = @_;
		2168
		2169	my $handle = new AnyEvent::Handle
		2170	fh => $fh,
		2171	peername => $host,
		2172	tls => "connect",
		2173	tls_ctx => { verify => 1, verify_peername => "https" },
		2174	...
		2175
		2176	Note that you must specify the hostname you connected to (or whatever
		2177	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2178	peername verification will be done.
		2179
		2180	The above will use the system-dependent default set of trusted CA
		2181	certificates. If you want to check against a specific CA, add the
		2182	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2183
		2184	tls_ctx => {
		2185	verify => 1,
		2186	verify_peername => "https",
		2187	ca_file => "my-ca-cert.pem",
		2188	},
		2189
		2190	=item I want to create a TLS/SSL server, how do I do that?
		2191
		2192	Well, you first need to get a server certificate and key. You have
		2193	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2194	self-signed certificate (cheap. check the search engine of your choice,
		2195	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2196	nice program for that purpose).
		2197
		2198	Then create a file with your private key (in PEM format, see
		2199	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2200	file should then look like this:
		2201
		2202	-----BEGIN RSA PRIVATE KEY-----
		2203	...header data
		2204	... lots of base64'y-stuff
		2205	-----END RSA PRIVATE KEY-----
		2206
		2207	-----BEGIN CERTIFICATE-----
		2208	... lots of base64'y-stuff
		2209	-----END CERTIFICATE-----
		2210
		2211	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2212	specify this file as C<cert_file>:
		2213
		2214	tcp_server undef, $port, sub {
		2215	my ($fh) = @_;
		2216
		2217	my $handle = new AnyEvent::Handle
		2218	fh => $fh,
		2219	tls => "accept",
		2220	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2221	...
		2222
		2223	When you have intermediate CA certificates that your clients might not
		2224	know about, just append them to the C<cert_file>.
		2225
		2226	=back
		2227
		2228
		2229	=head1 SUBCLASSING AnyEvent::Handle
		2230
		2231	In many cases, you might want to subclass AnyEvent::Handle.
		2232
		2233	To make this easier, a given version of AnyEvent::Handle uses these
		2234	conventions:
		2235
		2236	=over 4
		2237
		2238	=item * all constructor arguments become object members.
		2239
		2240	At least initially, when you pass a C<tls>-argument to the constructor it
		2241	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2242	mutated later on (for example C<tls> will hold the TLS connection object).
		2243
		2244	=item * other object member names are prefixed with an C<_>.
		2245
		2246	All object members not explicitly documented (internal use) are prefixed
		2247	with an underscore character, so the remaining non-C<_>-namespace is free
		2248	for use for subclasses.
		2249
		2250	=item * all members not documented here and not prefixed with an underscore
		2251	are free to use in subclasses.
		2252
		2253	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2254	member variables, but thats just life, at least it is documented.
		2255
		2256	=back
		2257
487	=head1 AUTHOR	2258	=head1 AUTHOR
488		2259
489	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2260	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
490		2261
491	=cut	2262	=cut

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