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Revision 1.9 by root, Fri May 2 16:07:46 2008 UTC vs.
Revision 1.193 by root, Mon Mar 15 18:51:30 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
…		…
200		601
201	sub on_eof {	602	sub on_eof {
202	$_[0]{on_eof} = $_[1];	603	$_[0]{on_eof} = $_[1];
203	}	604	}
204		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
205	#############################################################################	815	#############################################################################
206		816
207	=back	817	=back
208		818
209	=head2 WRITE QUEUE	819	=head2 WRITE QUEUE
…		…
212	for reading.	822	for reading.
213		823
214	The write queue is very simple: you can add data to its end, and	824	The write queue is very simple: you can add data to its end, and
215	AnyEvent::Handle will automatically try to get rid of it for you.	825	AnyEvent::Handle will automatically try to get rid of it for you.
216		826
217	When data could be writtena nd the write buffer is shorter then the low	827	When data could be written and the write buffer is shorter then the low
218	water mark, the C<on_drain> callback will be invoked.	828	water mark, the C<on_drain> callback will be invoked.
219		829
220	=over 4	830	=over 4
221		831
222	=item $handle->on_drain ($cb)	832	=item $handle->on_drain ($cb)
223		833
224	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
225	C<on_drain> in the constructor).	835	C<on_drain> in the constructor).
226		836
		837	This method may invoke callbacks (and therefore the handle might be
		838	destroyed after it returns).
		839
227	=cut	840	=cut
228		841
229	sub on_drain {	842	sub on_drain {
230	my ($self, $cb) = @_;	843	my ($self, $cb) = @_;
231		844
232	$self->{on_drain} = $cb;	845	$self->{on_drain} = $cb;
233		846
234	$cb->($self)	847	$cb->($self)
235	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	848	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
236	}	849	}
237		850
238	=item $handle->push_write ($data)	851	=item $handle->push_write ($data)
239		852
240	Queues the given scalar to be written. You can push as much data as you	853	Queues the given scalar to be written. You can push as much data as you
241	want (only limited by the available memory), as C<AnyEvent::Handle>	854	want (only limited by the available memory), as C<AnyEvent::Handle>
242	buffers it independently of the kernel.	855	buffers it independently of the kernel.
243		856
244	=cut	857	This method may invoke callbacks (and therefore the handle might be
		858	destroyed after it returns).
245		859
246	sub push_write {	860	=cut
		861
		862	sub _drain_wbuf {
247	my ($self, $data) = @_;	863	my ($self) = @_;
248		864
249	$self->{wbuf} .= $data;	865	if (!$self->{_ww} && length $self->{wbuf}) {
250		866
251	unless ($self->{ww}) {
252	Scalar::Util::weaken $self;	867	Scalar::Util::weaken $self;
		868
253	my $cb = sub {	869	my $cb = sub {
254	my $len = syswrite $self->{fh}, $self->{wbuf};	870	my $len = syswrite $self->{fh}, $self->{wbuf};
255		871
256	if ($len > 0) {	872	if (defined $len) {
257	substr $self->{wbuf}, 0, $len, "";	873	substr $self->{wbuf}, 0, $len, "";
258		874
		875	$self->{_activity} = $self->{_wactivity} = AE::now;
259		876
260	$self->{on_drain}($self)	877	$self->{on_drain}($self)
261	if $self->{low_water_mark} >= length $self->{wbuf}	878	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
262	&& $self->{on_drain};	879	&& $self->{on_drain};
263		880
264	delete $self->{ww} unless length $self->{wbuf};	881	delete $self->{_ww} unless length $self->{wbuf};
265	} elsif ($! != EAGAIN && $! != EINTR) {	882	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
266	$self->error;	883	$self->_error ($!, 1);
267	}	884	}
268	};	885	};
269		886
270	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	887	# try to write data immediately
		888	$cb->() unless $self->{autocork};
271		889
272	$cb->($self);	890	# if still data left in wbuf, we need to poll
		891	$self->{_ww} = AE::io $self->{fh}, 1, $cb
		892	if length $self->{wbuf};
273	};	893	};
274	}	894	}
		895
		896	our %WH;
		897
		898	# deprecated
		899	sub register_write_type($$) {
		900	$WH{$_[0]} = $_[1];
		901	}
		902
		903	sub push_write {
		904	my $self = shift;
		905
		906	if (@_ > 1) {
		907	my $type = shift;
		908
		909	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
		910	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
		911	->($self, @_);
		912	}
		913
		914	# we downgrade here to avoid hard-to-track-down bugs,
		915	# and diagnose the problem earlier and better.
		916
		917	if ($self->{tls}) {
		918	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
		919	&_dotls ($self) if $self->{fh};
		920	} else {
		921	utf8::downgrade $self->{wbuf} .= $_[0];
		922	$self->_drain_wbuf if $self->{fh};
		923	}
		924	}
		925
		926	=item $handle->push_write (type => @args)
		927
		928	Instead of formatting your data yourself, you can also let this module
		929	do the job by specifying a type and type-specific arguments. You
		930	can also specify the (fully qualified) name of a package, in which
		931	case AnyEvent tries to load the package and then expects to find the
		932	C<anyevent_read_type> function inside (see "custom write types", below).
		933
		934	Predefined types are (if you have ideas for additional types, feel free to
		935	drop by and tell us):
		936
		937	=over 4
		938
		939	=item netstring => $string
		940
		941	Formats the given value as netstring
		942	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		943
		944	=cut
		945
		946	register_write_type netstring => sub {
		947	my ($self, $string) = @_;
		948
		949	(length $string) . ":$string,"
		950	};
		951
		952	=item packstring => $format, $data
		953
		954	An octet string prefixed with an encoded length. The encoding C<$format>
		955	uses the same format as a Perl C<pack> format, but must specify a single
		956	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		957	optional C<!>, C<< < >> or C<< > >> modifier).
		958
		959	=cut
		960
		961	register_write_type packstring => sub {
		962	my ($self, $format, $string) = @_;
		963
		964	pack "$format/a*", $string
		965	};
		966
		967	=item json => $array_or_hashref
		968
		969	Encodes the given hash or array reference into a JSON object. Unless you
		970	provide your own JSON object, this means it will be encoded to JSON text
		971	in UTF-8.
		972
		973	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		974	one end of a handle and read them at the other end without using any
		975	additional framing.
		976
		977	The generated JSON text is guaranteed not to contain any newlines: While
		978	this module doesn't need delimiters after or between JSON texts to be
		979	able to read them, many other languages depend on that.
		980
		981	A simple RPC protocol that interoperates easily with others is to send
		982	JSON arrays (or objects, although arrays are usually the better choice as
		983	they mimic how function argument passing works) and a newline after each
		984	JSON text:
		985
		986	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		987	$handle->push_write ("\012");
		988
		989	An AnyEvent::Handle receiver would simply use the C<json> read type and
		990	rely on the fact that the newline will be skipped as leading whitespace:
		991
		992	$handle->push_read (json => sub { my $array = $_[1]; ... });
		993
		994	Other languages could read single lines terminated by a newline and pass
		995	this line into their JSON decoder of choice.
		996
		997	=cut
		998
		999	sub json_coder() {
		1000	eval { require JSON::XS; JSON::XS->new->utf8 }
		1001	|| do { require JSON; JSON->new->utf8 }
		1002	}
		1003
		1004	register_write_type json => sub {
		1005	my ($self, $ref) = @_;
		1006
		1007	my $json = $self->{json} ||= json_coder;
		1008
		1009	$json->encode ($ref)
		1010	};
		1011
		1012	=item storable => $reference
		1013
		1014	Freezes the given reference using L<Storable> and writes it to the
		1015	handle. Uses the C<nfreeze> format.
		1016
		1017	=cut
		1018
		1019	register_write_type storable => sub {
		1020	my ($self, $ref) = @_;
		1021
		1022	require Storable;
		1023
		1024	pack "w/a*", Storable::nfreeze ($ref)
		1025	};
		1026
		1027	=back
		1028
		1029	=item $handle->push_shutdown
		1030
		1031	Sometimes you know you want to close the socket after writing your data
		1032	before it was actually written. One way to do that is to replace your
		1033	C<on_drain> handler by a callback that shuts down the socket (and set
		1034	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1035	replaces the C<on_drain> callback with:
		1036
		1037	sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
		1038
		1039	This simply shuts down the write side and signals an EOF condition to the
		1040	the peer.
		1041
		1042	You can rely on the normal read queue and C<on_eof> handling
		1043	afterwards. This is the cleanest way to close a connection.
		1044
		1045	This method may invoke callbacks (and therefore the handle might be
		1046	destroyed after it returns).
		1047
		1048	=cut
		1049
		1050	sub push_shutdown {
		1051	my ($self) = @_;
		1052
		1053	delete $self->{low_water_mark};
		1054	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1055	}
		1056
		1057	=item custom write types - Package::anyevent_write_type $handle, @args
		1058
		1059	Instead of one of the predefined types, you can also specify the name of
		1060	a package. AnyEvent will try to load the package and then expects to find
		1061	a function named C<anyevent_write_type> inside. If it isn't found, it
		1062	progressively tries to load the parent package until it either finds the
		1063	function (good) or runs out of packages (bad).
		1064
		1065	Whenever the given C<type> is used, C<push_write> will the function with
		1066	the handle object and the remaining arguments.
		1067
		1068	The function is supposed to return a single octet string that will be
		1069	appended to the write buffer, so you cna mentally treat this function as a
		1070	"arguments to on-the-wire-format" converter.
		1071
		1072	Example: implement a custom write type C<join> that joins the remaining
		1073	arguments using the first one.
		1074
		1075	$handle->push_write (My::Type => " ", 1,2,3);
		1076
		1077	# uses the following package, which can be defined in the "My::Type" or in
		1078	# the "My" modules to be auto-loaded, or just about anywhere when the
		1079	# My::Type::anyevent_write_type is defined before invoking it.
		1080
		1081	package My::Type;
		1082
		1083	sub anyevent_write_type {
		1084	my ($handle, $delim, @args) = @_;
		1085
		1086	join $delim, @args
		1087	}
		1088
		1089	=cut
275		1090
276	#############################################################################	1091	#############################################################################
277		1092
278	=back	1093	=back
279		1094
…		…
286	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1101	ways, the "simple" way, using only C<on_read> and the "complex" way, using
287	a queue.	1102	a queue.
288		1103
289	In the simple case, you just install an C<on_read> callback and whenever	1104	In the simple case, you just install an C<on_read> callback and whenever
290	new data arrives, it will be called. You can then remove some data (if	1105	new data arrives, it will be called. You can then remove some data (if
291	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	1106	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
292	or not.	1107	leave the data there if you want to accumulate more (e.g. when only a
		1108	partial message has been received so far).
293		1109
294	In the more complex case, you want to queue multiple callbacks. In this	1110	In the more complex case, you want to queue multiple callbacks. In this
295	case, AnyEvent::Handle will call the first queued callback each time new	1111	case, AnyEvent::Handle will call the first queued callback each time new
296	data arrives and removes it when it has done its job (see C<push_read>,	1112	data arrives (also the first time it is queued) and removes it when it has
297	below).	1113	done its job (see C<push_read>, below).
298		1114
299	This way you can, for example, push three line-reads, followed by reading	1115	This way you can, for example, push three line-reads, followed by reading
300	a chunk of data, and AnyEvent::Handle will execute them in order.	1116	a chunk of data, and AnyEvent::Handle will execute them in order.
301		1117
302	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	1118	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
303	the specified number of bytes which give an XML datagram.	1119	the specified number of bytes which give an XML datagram.
304		1120
305	# in the default state, expect some header bytes	1121	# in the default state, expect some header bytes
306	$handle->on_read (sub {	1122	$handle->on_read (sub {
307	# some data is here, now queue the length-header-read (4 octets)	1123	# some data is here, now queue the length-header-read (4 octets)
308	shift->unshift_read_chunk (4, sub {	1124	shift->unshift_read (chunk => 4, sub {
309	# header arrived, decode	1125	# header arrived, decode
310	my $len = unpack "N", $_[1];	1126	my $len = unpack "N", $_[1];
311		1127
312	# now read the payload	1128	# now read the payload
313	shift->unshift_read_chunk ($len, sub {	1129	shift->unshift_read (chunk => $len, sub {
314	my $xml = $_[1];	1130	my $xml = $_[1];
315	# handle xml	1131	# handle xml
316	});	1132	});
317	});	1133	});
318	});	1134	});
319		1135
320	Example 2: Implement a client for a protocol that replies either with	1136	Example 2: Implement a client for a protocol that replies either with "OK"
321	"OK" and another line or "ERROR" for one request, and 64 bytes for the	1137	and another line or "ERROR" for the first request that is sent, and 64
322	second request. Due tot he availability of a full queue, we can just	1138	bytes for the second request. Due to the availability of a queue, we can
323	pipeline sending both requests and manipulate the queue as necessary in	1139	just pipeline sending both requests and manipulate the queue as necessary
324	the callbacks:	1140	in the callbacks.
325		1141
326	# request one	1142	When the first callback is called and sees an "OK" response, it will
		1143	C<unshift> another line-read. This line-read will be queued I<before> the
		1144	64-byte chunk callback.
		1145
		1146	# request one, returns either "OK + extra line" or "ERROR"
327	$handle->push_write ("request 1\015\012");	1147	$handle->push_write ("request 1\015\012");
328		1148
329	# we expect "ERROR" or "OK" as response, so push a line read	1149	# we expect "ERROR" or "OK" as response, so push a line read
330	$handle->push_read_line (sub {	1150	$handle->push_read (line => sub {
331	# if we got an "OK", we have to _prepend_ another line,	1151	# if we got an "OK", we have to _prepend_ another line,
332	# so it will be read before the second request reads its 64 bytes	1152	# so it will be read before the second request reads its 64 bytes
333	# which are already in the queue when this callback is called	1153	# which are already in the queue when this callback is called
334	# we don't do this in case we got an error	1154	# we don't do this in case we got an error
335	if ($_[1] eq "OK") {	1155	if ($_[1] eq "OK") {
336	$_[0]->unshift_read_line (sub {	1156	$_[0]->unshift_read (line => sub {
337	my $response = $_[1];	1157	my $response = $_[1];
338	...	1158	...
339	});	1159	});
340	}	1160	}
341	});	1161	});
342		1162
343	# request two	1163	# request two, simply returns 64 octets
344	$handle->push_write ("request 2\015\012");	1164	$handle->push_write ("request 2\015\012");
345		1165
346	# simply read 64 bytes, always	1166	# simply read 64 bytes, always
347	$handle->push_read_chunk (64, sub {	1167	$handle->push_read (chunk => 64, sub {
348	my $response = $_[1];	1168	my $response = $_[1];
349	...	1169	...
350	});	1170	});
351		1171
352	=over 4	1172	=over 4
353		1173
		1174	=cut
		1175
354	sub _drain_rbuf {	1176	sub _drain_rbuf {
355	my ($self) = @_;	1177	my ($self) = @_;
356		1178
		1179	# avoid recursion
357	return if exists $self->{in_drain};	1180	return if $self->{_skip_drain_rbuf};
358	local $self->{in_drain} = 1;	1181	local $self->{_skip_drain_rbuf} = 1;
359		1182
		1183	while () {
		1184	# we need to use a separate tls read buffer, as we must not receive data while
		1185	# we are draining the buffer, and this can only happen with TLS.
		1186	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1187	if exists $self->{_tls_rbuf};
		1188
360	while (my $len = length $self->{rbuf}) {	1189	my $len = length $self->{rbuf};
361	no strict 'refs';	1190
362	if (@{ $self->{queue} }) {	1191	if (my $cb = shift @{ $self->{_queue} }) {
363	if ($self->{queue}[0]($self)) {	1192	unless ($cb->($self)) {
		1193	# no progress can be made
		1194	# (not enough data and no data forthcoming)
		1195	$self->_error (Errno::EPIPE, 1), return
		1196	if $self->{_eof};
		1197
364	shift @{ $self->{queue} };	1198	unshift @{ $self->{_queue} }, $cb;
365	} elsif ($self->{eof}) {
366	# no progress can be made (not enough data and no data forthcoming)
367	$! = &Errno::EPIPE; return $self->error;
368	} else {
369	return;	1199	last;
370	}	1200	}
371	} elsif ($self->{on_read}) {	1201	} elsif ($self->{on_read}) {
		1202	last unless $len;
		1203
372	$self->{on_read}($self);	1204	$self->{on_read}($self);
373		1205
374	if (	1206	if (
375	$self->{eof} # if no further data will arrive
376	&& $len == length $self->{rbuf} # and no data has been consumed	1207	$len == length $self->{rbuf} # if no data has been consumed
377	&& !@{ $self->{queue} } # and the queue is still empty	1208	&& !@{ $self->{_queue} } # and the queue is still empty
378	&& $self->{on_read} # and we still want to read data	1209	&& $self->{on_read} # but we still have on_read
379	) {	1210	) {
		1211	# no further data will arrive
380	# then no progress can be made	1212	# so no progress can be made
381	$! = &Errno::EPIPE; return $self->error;	1213	$self->_error (Errno::EPIPE, 1), return
		1214	if $self->{_eof};
		1215
		1216	last; # more data might arrive
382	}	1217	}
383	} else {	1218	} else {
384	# read side becomes idle	1219	# read side becomes idle
385	delete $self->{rw};	1220	delete $self->{_rw} unless $self->{tls};
386	return;	1221	last;
387	}	1222	}
388	}	1223	}
389		1224
390	if ($self->{eof}) {	1225	if ($self->{_eof}) {
391	$self->_shutdown;	1226	$self->{on_eof}
392	$self->{on_eof}($self);	1227	? $self->{on_eof}($self)
		1228	: $self->_error (0, 1, "Unexpected end-of-file");
		1229
		1230	return;
		1231	}
		1232
		1233	if (
		1234	defined $self->{rbuf_max}
		1235	&& $self->{rbuf_max} < length $self->{rbuf}
		1236	) {
		1237	$self->_error (Errno::ENOSPC, 1), return;
		1238	}
		1239
		1240	# may need to restart read watcher
		1241	unless ($self->{_rw}) {
		1242	$self->start_read
		1243	if $self->{on_read} || @{ $self->{_queue} };
393	}	1244	}
394	}	1245	}
395		1246
396	=item $handle->on_read ($cb)	1247	=item $handle->on_read ($cb)
397		1248
398	This replaces the currently set C<on_read> callback, or clears it (when	1249	This replaces the currently set C<on_read> callback, or clears it (when
399	the new callback is C<undef>). See the description of C<on_read> in the	1250	the new callback is C<undef>). See the description of C<on_read> in the
400	constructor.	1251	constructor.
401		1252
		1253	This method may invoke callbacks (and therefore the handle might be
		1254	destroyed after it returns).
		1255
402	=cut	1256	=cut
403		1257
404	sub on_read {	1258	sub on_read {
405	my ($self, $cb) = @_;	1259	my ($self, $cb) = @_;
406		1260
407	$self->{on_read} = $cb;	1261	$self->{on_read} = $cb;
408
409	unless ($self->{rw} || $self->{eof}) {
410	Scalar::Util::weaken $self;
411
412	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
413	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};
414
415	if ($len > 0) {
416	if (exists $self->{rbuf_max}) {
417	if ($self->{rbuf_max} < length $self->{rbuf}) {
418	$! = &Errno::ENOSPC; return $self->error;
419	}
420	}
421
422	} elsif (defined $len) {
423	$self->{eof} = 1;
424	delete $self->{rw};
425
426	} elsif ($! != EAGAIN && $! != EINTR) {
427	return $self->error;
428	}
429
430	$self->_drain_rbuf;	1262	$self->_drain_rbuf if $cb;
431	});
432	}
433	}	1263	}
434		1264
435	=item $handle->rbuf	1265	=item $handle->rbuf
436		1266
437	Returns the read buffer (as a modifiable lvalue).	1267	Returns the read buffer (as a modifiable lvalue).
438		1268
439	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1269	You can access the read buffer directly as the C<< ->{rbuf} >>
440	you want.	1270	member, if you want. However, the only operation allowed on the
		1271	read buffer (apart from looking at it) is removing data from its
		1272	beginning. Otherwise modifying or appending to it is not allowed and will
		1273	lead to hard-to-track-down bugs.
441		1274
442	NOTE: The read buffer should only be used or modified if the C<on_read>,	1275	NOTE: The read buffer should only be used or modified if the C<on_read>,
443	C<push_read> or C<unshift_read> methods are used. The other read methods	1276	C<push_read> or C<unshift_read> methods are used. The other read methods
444	automatically manage the read buffer.	1277	automatically manage the read buffer.
445		1278
…		…
456	Append the given callback to the end of the queue (C<push_read>) or	1289	Append the given callback to the end of the queue (C<push_read>) or
457	prepend it (C<unshift_read>).	1290	prepend it (C<unshift_read>).
458		1291
459	The callback is called each time some additional read data arrives.	1292	The callback is called each time some additional read data arrives.
460		1293
461	It must check wether enough data is in the read buffer already.	1294	It must check whether enough data is in the read buffer already.
462		1295
463	If not enough data is available, it must return the empty list or a false	1296	If not enough data is available, it must return the empty list or a false
464	value, in which case it will be called repeatedly until enough data is	1297	value, in which case it will be called repeatedly until enough data is
465	available (or an error condition is detected).	1298	available (or an error condition is detected).
466		1299
467	If enough data was available, then the callback must remove all data it is	1300	If enough data was available, then the callback must remove all data it is
468	interested in (which can be none at all) and return a true value. After returning	1301	interested in (which can be none at all) and return a true value. After returning
469	true, it will be removed from the queue.	1302	true, it will be removed from the queue.
470		1303
		1304	These methods may invoke callbacks (and therefore the handle might be
		1305	destroyed after it returns).
		1306
471	=cut	1307	=cut
		1308
		1309	our %RH;
		1310
		1311	sub register_read_type($$) {
		1312	$RH{$_[0]} = $_[1];
		1313	}
472		1314
473	sub push_read {	1315	sub push_read {
474	my ($self, $cb) = @_;	1316	my $self = shift;
		1317	my $cb = pop;
475		1318
		1319	if (@_) {
		1320	my $type = shift;
		1321
		1322	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
		1323	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
		1324	->($self, $cb, @_);
		1325	}
		1326
476	push @{ $self->{queue} }, $cb;	1327	push @{ $self->{_queue} }, $cb;
477	$self->_drain_rbuf;	1328	$self->_drain_rbuf;
478	}	1329	}
479		1330
480	sub unshift_read {	1331	sub unshift_read {
481	my ($self, $cb) = @_;	1332	my $self = shift;
		1333	my $cb = pop;
482		1334
		1335	if (@_) {
		1336	my $type = shift;
		1337
		1338	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		1339	->($self, $cb, @_);
		1340	}
		1341
483	push @{ $self->{queue} }, $cb;	1342	unshift @{ $self->{_queue} }, $cb;
484	$self->_drain_rbuf;	1343	$self->_drain_rbuf;
485	}	1344	}
486		1345
487	=item $handle->push_read_chunk ($len, $cb->($self, $data))	1346	=item $handle->push_read (type => @args, $cb)
488		1347
489	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	1348	=item $handle->unshift_read (type => @args, $cb)
490		1349
491	Append the given callback to the end of the queue (C<push_read_chunk>) or	1350	Instead of providing a callback that parses the data itself you can chose
492	prepend it (C<unshift_read_chunk>).	1351	between a number of predefined parsing formats, for chunks of data, lines
		1352	etc. You can also specify the (fully qualified) name of a package, in
		1353	which case AnyEvent tries to load the package and then expects to find the
		1354	C<anyevent_read_type> function inside (see "custom read types", below).
493		1355
494	The callback will be called only once C<$len> bytes have been read, and	1356	Predefined types are (if you have ideas for additional types, feel free to
495	these C<$len> bytes will be passed to the callback.	1357	drop by and tell us):
496		1358
497	=cut	1359	=over 4
498		1360
499	sub _read_chunk($$) {	1361	=item chunk => $octets, $cb->($handle, $data)
500	my ($len, $cb) = @_;	1362
		1363	Invoke the callback only once C<$octets> bytes have been read. Pass the
		1364	data read to the callback. The callback will never be called with less
		1365	data.
		1366
		1367	Example: read 2 bytes.
		1368
		1369	$handle->push_read (chunk => 2, sub {
		1370	warn "yay ", unpack "H*", $_[1];
		1371	});
		1372
		1373	=cut
		1374
		1375	register_read_type chunk => sub {
		1376	my ($self, $cb, $len) = @_;
501		1377
502	sub {	1378	sub {
503	$len <= length $_[0]{rbuf} or return;	1379	$len <= length $_[0]{rbuf} or return;
504	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	1380	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
505	1	1381	1
506	}	1382	}
507	}	1383	};
508		1384
509	sub push_read_chunk {	1385	=item line => [$eol, ]$cb->($handle, $line, $eol)
510	my ($self, $len, $cb) = @_;
511
512	$self->push_read (_read_chunk $len, $cb);
513	}
514
515
516	sub unshift_read_chunk {
517	my ($self, $len, $cb) = @_;
518
519	$self->unshift_read (_read_chunk $len, $cb);
520	}
521
522	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
523
524	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
525
526	Append the given callback to the end of the queue (C<push_read_line>) or
527	prepend it (C<unshift_read_line>).
528		1386
529	The callback will be called only once a full line (including the end of	1387	The callback will be called only once a full line (including the end of
530	line marker, C<$eol>) has been read. This line (excluding the end of line	1388	line marker, C<$eol>) has been read. This line (excluding the end of line
531	marker) will be passed to the callback as second argument (C<$line>), and	1389	marker) will be passed to the callback as second argument (C<$line>), and
532	the end of line marker as the third argument (C<$eol>).	1390	the end of line marker as the third argument (C<$eol>).
…		…
543	Partial lines at the end of the stream will never be returned, as they are	1401	Partial lines at the end of the stream will never be returned, as they are
544	not marked by the end of line marker.	1402	not marked by the end of line marker.
545		1403
546	=cut	1404	=cut
547		1405
548	sub _read_line($$) {	1406	register_read_type line => sub {
549	my $cb = pop;	1407	my ($self, $cb, $eol) = @_;
550	my $eol = @_ ? shift : qr|(\015?\012)|;
551	my $pos;
552		1408
		1409	if (@_ < 3) {
		1410	# this is more than twice as fast as the generic code below
		1411	sub {
		1412	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		1413
		1414	$cb->($_[0], $1, $2);
		1415	1
		1416	}
		1417	} else {
553	$eol = qr|(\Q$eol\E)| unless ref $eol;	1418	$eol = quotemeta $eol unless ref $eol;
554	$eol = qr|^(.*?)($eol)|;	1419	$eol = qr|^(.*?)($eol)|s;
		1420
		1421	sub {
		1422	$_[0]{rbuf} =~ s/$eol// or return;
		1423
		1424	$cb->($_[0], $1, $2);
		1425	1
		1426	}
		1427	}
		1428	};
		1429
		1430	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1431
		1432	Makes a regex match against the regex object C<$accept> and returns
		1433	everything up to and including the match.
		1434
		1435	Example: read a single line terminated by '\n'.
		1436
		1437	$handle->push_read (regex => qr<\n>, sub { ... });
		1438
		1439	If C<$reject> is given and not undef, then it determines when the data is
		1440	to be rejected: it is matched against the data when the C<$accept> regex
		1441	does not match and generates an C<EBADMSG> error when it matches. This is
		1442	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1443	receive buffer overflow).
		1444
		1445	Example: expect a single decimal number followed by whitespace, reject
		1446	anything else (not the use of an anchor).
		1447
		1448	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1449
		1450	If C<$skip> is given and not C<undef>, then it will be matched against
		1451	the receive buffer when neither C<$accept> nor C<$reject> match,
		1452	and everything preceding and including the match will be accepted
		1453	unconditionally. This is useful to skip large amounts of data that you
		1454	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1455	have to start matching from the beginning. This is purely an optimisation
		1456	and is usually worth only when you expect more than a few kilobytes.
		1457
		1458	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1459	expect the header to be very large (it isn't in practise, but...), we use
		1460	a skip regex to skip initial portions. The skip regex is tricky in that
		1461	it only accepts something not ending in either \015 or \012, as these are
		1462	required for the accept regex.
		1463
		1464	$handle->push_read (regex =>
		1465	qr<\015\012\015\012>,
		1466	undef, # no reject
		1467	qr<^.*[^\015\012]>,
		1468	sub { ... });
		1469
		1470	=cut
		1471
		1472	register_read_type regex => sub {
		1473	my ($self, $cb, $accept, $reject, $skip) = @_;
		1474
		1475	my $data;
		1476	my $rbuf = \$self->{rbuf};
555		1477
556	sub {	1478	sub {
557	$_[0]{rbuf} =~ s/$eol// or return;	1479	# accept
		1480	if ($$rbuf =~ $accept) {
		1481	$data .= substr $$rbuf, 0, $+[0], "";
		1482	$cb->($self, $data);
		1483	return 1;
		1484	}
		1485
		1486	# reject
		1487	if ($reject && $$rbuf =~ $reject) {
		1488	$self->_error (Errno::EBADMSG);
		1489	}
558		1490
559	$cb->($1, $2);	1491	# skip
		1492	if ($skip && $$rbuf =~ $skip) {
		1493	$data .= substr $$rbuf, 0, $+[0], "";
		1494	}
		1495
		1496	()
		1497	}
		1498	};
		1499
		1500	=item netstring => $cb->($handle, $string)
		1501
		1502	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1503
		1504	Throws an error with C<$!> set to EBADMSG on format violations.
		1505
		1506	=cut
		1507
		1508	register_read_type netstring => sub {
		1509	my ($self, $cb) = @_;
		1510
		1511	sub {
		1512	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1513	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1514	$self->_error (Errno::EBADMSG);
		1515	}
		1516	return;
		1517	}
		1518
		1519	my $len = $1;
		1520
		1521	$self->unshift_read (chunk => $len, sub {
		1522	my $string = $_[1];
		1523	$_[0]->unshift_read (chunk => 1, sub {
		1524	if ($_[1] eq ",") {
		1525	$cb->($_[0], $string);
		1526	} else {
		1527	$self->_error (Errno::EBADMSG);
		1528	}
		1529	});
		1530	});
		1531
560	1	1532	1
561	}	1533	}
562	}	1534	};
563		1535
564	sub push_read_line {	1536	=item packstring => $format, $cb->($handle, $string)
565	my $self = shift;
566		1537
567	$self->push_read (&_read_line);	1538	An octet string prefixed with an encoded length. The encoding C<$format>
568	}	1539	uses the same format as a Perl C<pack> format, but must specify a single
		1540	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1541	optional C<!>, C<< < >> or C<< > >> modifier).
569		1542
570	sub unshift_read_line {	1543	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
571	my $self = shift;	1544	EPP uses a prefix of C<N> (4 octtes).
572		1545
573	$self->unshift_read (&_read_line);	1546	Example: read a block of data prefixed by its length in BER-encoded
574	}	1547	format (very efficient).
		1548
		1549	$handle->push_read (packstring => "w", sub {
		1550	my ($handle, $data) = @_;
		1551	});
		1552
		1553	=cut
		1554
		1555	register_read_type packstring => sub {
		1556	my ($self, $cb, $format) = @_;
		1557
		1558	sub {
		1559	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1560	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1561	or return;
		1562
		1563	$format = length pack $format, $len;
		1564
		1565	# bypass unshift if we already have the remaining chunk
		1566	if ($format + $len <= length $_[0]{rbuf}) {
		1567	my $data = substr $_[0]{rbuf}, $format, $len;
		1568	substr $_[0]{rbuf}, 0, $format + $len, "";
		1569	$cb->($_[0], $data);
		1570	} else {
		1571	# remove prefix
		1572	substr $_[0]{rbuf}, 0, $format, "";
		1573
		1574	# read remaining chunk
		1575	$_[0]->unshift_read (chunk => $len, $cb);
		1576	}
		1577
		1578	1
		1579	}
		1580	};
		1581
		1582	=item json => $cb->($handle, $hash_or_arrayref)
		1583
		1584	Reads a JSON object or array, decodes it and passes it to the
		1585	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1586
		1587	If a C<json> object was passed to the constructor, then that will be used
		1588	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1589
		1590	This read type uses the incremental parser available with JSON version
		1591	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1592	dependency on your own: this module will load the JSON module, but
		1593	AnyEvent does not depend on it itself.
		1594
		1595	Since JSON texts are fully self-delimiting, the C<json> read and write
		1596	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1597	the C<json> write type description, above, for an actual example.
		1598
		1599	=cut
		1600
		1601	register_read_type json => sub {
		1602	my ($self, $cb) = @_;
		1603
		1604	my $json = $self->{json} ||= json_coder;
		1605
		1606	my $data;
		1607	my $rbuf = \$self->{rbuf};
		1608
		1609	sub {
		1610	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1611
		1612	if ($ref) {
		1613	$self->{rbuf} = $json->incr_text;
		1614	$json->incr_text = "";
		1615	$cb->($self, $ref);
		1616
		1617	1
		1618	} elsif ($@) {
		1619	# error case
		1620	$json->incr_skip;
		1621
		1622	$self->{rbuf} = $json->incr_text;
		1623	$json->incr_text = "";
		1624
		1625	$self->_error (Errno::EBADMSG);
		1626
		1627	()
		1628	} else {
		1629	$self->{rbuf} = "";
		1630
		1631	()
		1632	}
		1633	}
		1634	};
		1635
		1636	=item storable => $cb->($handle, $ref)
		1637
		1638	Deserialises a L<Storable> frozen representation as written by the
		1639	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1640	data).
		1641
		1642	Raises C<EBADMSG> error if the data could not be decoded.
		1643
		1644	=cut
		1645
		1646	register_read_type storable => sub {
		1647	my ($self, $cb) = @_;
		1648
		1649	require Storable;
		1650
		1651	sub {
		1652	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1653	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1654	or return;
		1655
		1656	my $format = length pack "w", $len;
		1657
		1658	# bypass unshift if we already have the remaining chunk
		1659	if ($format + $len <= length $_[0]{rbuf}) {
		1660	my $data = substr $_[0]{rbuf}, $format, $len;
		1661	substr $_[0]{rbuf}, 0, $format + $len, "";
		1662	$cb->($_[0], Storable::thaw ($data));
		1663	} else {
		1664	# remove prefix
		1665	substr $_[0]{rbuf}, 0, $format, "";
		1666
		1667	# read remaining chunk
		1668	$_[0]->unshift_read (chunk => $len, sub {
		1669	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1670	$cb->($_[0], $ref);
		1671	} else {
		1672	$self->_error (Errno::EBADMSG);
		1673	}
		1674	});
		1675	}
		1676
		1677	1
		1678	}
		1679	};
575		1680
576	=back	1681	=back
577		1682
		1683	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
		1684
		1685	Instead of one of the predefined types, you can also specify the name
		1686	of a package. AnyEvent will try to load the package and then expects to
		1687	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1688	progressively tries to load the parent package until it either finds the
		1689	function (good) or runs out of packages (bad).
		1690
		1691	Whenever this type is used, C<push_read> will invoke the function with the
		1692	handle object, the original callback and the remaining arguments.
		1693
		1694	The function is supposed to return a callback (usually a closure) that
		1695	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1696	mentally treat the function as a "configurable read type to read callback"
		1697	converter.
		1698
		1699	It should invoke the original callback when it is done reading (remember
		1700	to pass C<$handle> as first argument as all other callbacks do that,
		1701	although there is no strict requirement on this).
		1702
		1703	For examples, see the source of this module (F<perldoc -m
		1704	AnyEvent::Handle>, search for C<register_read_type>)).
		1705
		1706	=item $handle->stop_read
		1707
		1708	=item $handle->start_read
		1709
		1710	In rare cases you actually do not want to read anything from the
		1711	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1712	any queued callbacks will be executed then. To start reading again, call
		1713	C<start_read>.
		1714
		1715	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1716	you change the C<on_read> callback or push/unshift a read callback, and it
		1717	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1718	there are any read requests in the queue.
		1719
		1720	These methods will have no effect when in TLS mode (as TLS doesn't support
		1721	half-duplex connections).
		1722
		1723	=cut
		1724
		1725	sub stop_read {
		1726	my ($self) = @_;
		1727
		1728	delete $self->{_rw} unless $self->{tls};
		1729	}
		1730
		1731	sub start_read {
		1732	my ($self) = @_;
		1733
		1734	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
		1735	Scalar::Util::weaken $self;
		1736
		1737	$self->{_rw} = AE::io $self->{fh}, 0, sub {
		1738	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
		1739	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1740
		1741	if ($len > 0) {
		1742	$self->{_activity} = $self->{_ractivity} = AE::now;
		1743
		1744	if ($self->{tls}) {
		1745	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1746
		1747	&_dotls ($self);
		1748	} else {
		1749	$self->_drain_rbuf;
		1750	}
		1751
		1752	} elsif (defined $len) {
		1753	delete $self->{_rw};
		1754	$self->{_eof} = 1;
		1755	$self->_drain_rbuf;
		1756
		1757	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1758	return $self->_error ($!, 1);
		1759	}
		1760	};
		1761	}
		1762	}
		1763
		1764	our $ERROR_SYSCALL;
		1765	our $ERROR_WANT_READ;
		1766
		1767	sub _tls_error {
		1768	my ($self, $err) = @_;
		1769
		1770	return $self->_error ($!, 1)
		1771	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1772
		1773	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1774
		1775	# reduce error string to look less scary
		1776	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1777
		1778	if ($self->{_on_starttls}) {
		1779	(delete $self->{_on_starttls})->($self, undef, $err);
		1780	&_freetls;
		1781	} else {
		1782	&_freetls;
		1783	$self->_error (Errno::EPROTO, 1, $err);
		1784	}
		1785	}
		1786
		1787	# poll the write BIO and send the data if applicable
		1788	# also decode read data if possible
		1789	# this is basiclaly our TLS state machine
		1790	# more efficient implementations are possible with openssl,
		1791	# but not with the buggy and incomplete Net::SSLeay.
		1792	sub _dotls {
		1793	my ($self) = @_;
		1794
		1795	my $tmp;
		1796
		1797	if (length $self->{_tls_wbuf}) {
		1798	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1799	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1800	}
		1801
		1802	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1803	return $self->_tls_error ($tmp)
		1804	if $tmp != $ERROR_WANT_READ
		1805	&& ($tmp != $ERROR_SYSCALL || $!);
		1806	}
		1807
		1808	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1809	unless (length $tmp) {
		1810	$self->{_on_starttls}
		1811	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
		1812	&_freetls;
		1813
		1814	if ($self->{on_stoptls}) {
		1815	$self->{on_stoptls}($self);
		1816	return;
		1817	} else {
		1818	# let's treat SSL-eof as we treat normal EOF
		1819	delete $self->{_rw};
		1820	$self->{_eof} = 1;
		1821	}
		1822	}
		1823
		1824	$self->{_tls_rbuf} .= $tmp;
		1825	$self->_drain_rbuf;
		1826	$self->{tls} or return; # tls session might have gone away in callback
		1827	}
		1828
		1829	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1830	return $self->_tls_error ($tmp)
		1831	if $tmp != $ERROR_WANT_READ
		1832	&& ($tmp != $ERROR_SYSCALL || $!);
		1833
		1834	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1835	$self->{wbuf} .= $tmp;
		1836	$self->_drain_wbuf;
		1837	$self->{tls} or return; # tls session might have gone away in callback
		1838	}
		1839
		1840	$self->{_on_starttls}
		1841	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1842	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
		1843	}
		1844
		1845	=item $handle->starttls ($tls[, $tls_ctx])
		1846
		1847	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1848	object is created, you can also do that at a later time by calling
		1849	C<starttls>.
		1850
		1851	Starting TLS is currently an asynchronous operation - when you push some
		1852	write data and then call C<< ->starttls >> then TLS negotiation will start
		1853	immediately, after which the queued write data is then sent.
		1854
		1855	The first argument is the same as the C<tls> constructor argument (either
		1856	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1857
		1858	The second argument is the optional C<AnyEvent::TLS> object that is used
		1859	when AnyEvent::Handle has to create its own TLS connection object, or
		1860	a hash reference with C<< key => value >> pairs that will be used to
		1861	construct a new context.
		1862
		1863	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
		1864	context in C<< $handle->{tls_ctx} >> after this call and can be used or
		1865	changed to your liking. Note that the handshake might have already started
		1866	when this function returns.
		1867
		1868	Due to bugs in OpenSSL, it might or might not be possible to do multiple
		1869	handshakes on the same stream. Best do not attempt to use the stream after
		1870	stopping TLS.
		1871
		1872	This method may invoke callbacks (and therefore the handle might be
		1873	destroyed after it returns).
		1874
		1875	=cut
		1876
		1877	our %TLS_CACHE; #TODO not yet documented, should we?
		1878
		1879	sub starttls {
		1880	my ($self, $tls, $ctx) = @_;
		1881
		1882	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1883	if $self->{tls};
		1884
		1885	$self->{tls} = $tls;
		1886	$self->{tls_ctx} = $ctx if @_ > 2;
		1887
		1888	return unless $self->{fh};
		1889
		1890	require Net::SSLeay;
		1891
		1892	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
		1893	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1894
		1895	$tls = delete $self->{tls};
		1896	$ctx = $self->{tls_ctx};
		1897
		1898	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1899
		1900	if ("HASH" eq ref $ctx) {
		1901	require AnyEvent::TLS;
		1902
		1903	if ($ctx->{cache}) {
		1904	my $key = $ctx+0;
		1905	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1906	} else {
		1907	$ctx = new AnyEvent::TLS %$ctx;
		1908	}
		1909	}
		1910
		1911	$self->{tls_ctx} = $ctx || TLS_CTX ();
		1912	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
		1913
		1914	# basically, this is deep magic (because SSL_read should have the same issues)
		1915	# but the openssl maintainers basically said: "trust us, it just works".
		1916	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1917	# and mismaintained ssleay-module doesn't even offer them).
		1918	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1919	#
		1920	# in short: this is a mess.
		1921	#
		1922	# note that we do not try to keep the length constant between writes as we are required to do.
		1923	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1924	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1925	# have identity issues in that area.
		1926	# Net::SSLeay::CTX_set_mode ($ssl,
		1927	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1928	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1929	Net::SSLeay::CTX_set_mode ($tls, 1|2);
		1930
		1931	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1932	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1933
		1934	Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
		1935
		1936	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		1937
		1938	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		1939	if $self->{on_starttls};
		1940
		1941	&_dotls; # need to trigger the initial handshake
		1942	$self->start_read; # make sure we actually do read
		1943	}
		1944
		1945	=item $handle->stoptls
		1946
		1947	Shuts down the SSL connection - this makes a proper EOF handshake by
		1948	sending a close notify to the other side, but since OpenSSL doesn't
		1949	support non-blocking shut downs, it is not guaranteed that you can re-use
		1950	the stream afterwards.
		1951
		1952	This method may invoke callbacks (and therefore the handle might be
		1953	destroyed after it returns).
		1954
		1955	=cut
		1956
		1957	sub stoptls {
		1958	my ($self) = @_;
		1959
		1960	if ($self->{tls} && $self->{fh}) {
		1961	Net::SSLeay::shutdown ($self->{tls});
		1962
		1963	&_dotls;
		1964
		1965	# # we don't give a shit. no, we do, but we can't. no...#d#
		1966	# # we, we... have to use openssl :/#d#
		1967	# &_freetls;#d#
		1968	}
		1969	}
		1970
		1971	sub _freetls {
		1972	my ($self) = @_;
		1973
		1974	return unless $self->{tls};
		1975
		1976	$self->{tls_ctx}->_put_session (delete $self->{tls})
		1977	if $self->{tls} > 0;
		1978
		1979	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
		1980	}
		1981
		1982	sub DESTROY {
		1983	my ($self) = @_;
		1984
		1985	&_freetls;
		1986
		1987	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1988
		1989	if ($linger && length $self->{wbuf} && $self->{fh}) {
		1990	my $fh = delete $self->{fh};
		1991	my $wbuf = delete $self->{wbuf};
		1992
		1993	my @linger;
		1994
		1995	push @linger, AE::io $fh, 1, sub {
		1996	my $len = syswrite $fh, $wbuf, length $wbuf;
		1997
		1998	if ($len > 0) {
		1999	substr $wbuf, 0, $len, "";
		2000	} else {
		2001	@linger = (); # end
		2002	}
		2003	};
		2004	push @linger, AE::timer $linger, 0, sub {
		2005	@linger = ();
		2006	};
		2007	}
		2008	}
		2009
		2010	=item $handle->destroy
		2011
		2012	Shuts down the handle object as much as possible - this call ensures that
		2013	no further callbacks will be invoked and as many resources as possible
		2014	will be freed. Any method you will call on the handle object after
		2015	destroying it in this way will be silently ignored (and it will return the
		2016	empty list).
		2017
		2018	Normally, you can just "forget" any references to an AnyEvent::Handle
		2019	object and it will simply shut down. This works in fatal error and EOF
		2020	callbacks, as well as code outside. It does I<NOT> work in a read or write
		2021	callback, so when you want to destroy the AnyEvent::Handle object from
		2022	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		2023	that case.
		2024
		2025	Destroying the handle object in this way has the advantage that callbacks
		2026	will be removed as well, so if those are the only reference holders (as
		2027	is common), then one doesn't need to do anything special to break any
		2028	reference cycles.
		2029
		2030	The handle might still linger in the background and write out remaining
		2031	data, as specified by the C<linger> option, however.
		2032
		2033	=cut
		2034
		2035	sub destroy {
		2036	my ($self) = @_;
		2037
		2038	$self->DESTROY;
		2039	%$self = ();
		2040	bless $self, "AnyEvent::Handle::destroyed";
		2041	}
		2042
		2043	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2044	#nop
		2045	}
		2046
		2047	=item $handle->destroyed
		2048
		2049	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2050	->destroy >>, true otherwise.
		2051
		2052	Can be useful to decide whether the handle is still valid after some
		2053	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2054	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2055	can destroy the handle, so work can be avoided by checking sometimes:
		2056
		2057	$hdl->starttls ("accept");
		2058	return if $hdl->destroyed;
		2059	$hdl->push_write (...
		2060
		2061	Note that the call to C<push_write> will silently be ignored if the handle
		2062	has been destroyed, so often you can just ignore the possibility of the
		2063	handle being destroyed.
		2064
		2065	=cut
		2066
		2067	sub destroyed { 0 }
		2068	sub AnyEvent::Handle::destroyed::destroyed { 1 }
		2069
		2070	=item AnyEvent::Handle::TLS_CTX
		2071
		2072	This function creates and returns the AnyEvent::TLS object used by default
		2073	for TLS mode.
		2074
		2075	The context is created by calling L<AnyEvent::TLS> without any arguments.
		2076
		2077	=cut
		2078
		2079	our $TLS_CTX;
		2080
		2081	sub TLS_CTX() {
		2082	$TLS_CTX ||= do {
		2083	require AnyEvent::TLS;
		2084
		2085	new AnyEvent::TLS
		2086	}
		2087	}
		2088
		2089	=back
		2090
		2091
		2092	=head1 NONFREQUENTLY ASKED QUESTIONS
		2093
		2094	=over 4
		2095
		2096	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		2097	still get further invocations!
		2098
		2099	That's because AnyEvent::Handle keeps a reference to itself when handling
		2100	read or write callbacks.
		2101
		2102	It is only safe to "forget" the reference inside EOF or error callbacks,
		2103	from within all other callbacks, you need to explicitly call the C<<
		2104	->destroy >> method.
		2105
		2106	=item I get different callback invocations in TLS mode/Why can't I pause
		2107	reading?
		2108
		2109	Unlike, say, TCP, TLS connections do not consist of two independent
		2110	communication channels, one for each direction. Or put differently. The
		2111	read and write directions are not independent of each other: you cannot
		2112	write data unless you are also prepared to read, and vice versa.
		2113
		2114	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		2115	callback invocations when you are not expecting any read data - the reason
		2116	is that AnyEvent::Handle always reads in TLS mode.
		2117
		2118	During the connection, you have to make sure that you always have a
		2119	non-empty read-queue, or an C<on_read> watcher. At the end of the
		2120	connection (or when you no longer want to use it) you can call the
		2121	C<destroy> method.
		2122
		2123	=item How do I read data until the other side closes the connection?
		2124
		2125	If you just want to read your data into a perl scalar, the easiest way
		2126	to achieve this is by setting an C<on_read> callback that does nothing,
		2127	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		2128	will be in C<$_[0]{rbuf}>:
		2129
		2130	$handle->on_read (sub { });
		2131	$handle->on_eof (undef);
		2132	$handle->on_error (sub {
		2133	my $data = delete $_[0]{rbuf};
		2134	});
		2135
		2136	The reason to use C<on_error> is that TCP connections, due to latencies
		2137	and packets loss, might get closed quite violently with an error, when in
		2138	fact, all data has been received.
		2139
		2140	It is usually better to use acknowledgements when transferring data,
		2141	to make sure the other side hasn't just died and you got the data
		2142	intact. This is also one reason why so many internet protocols have an
		2143	explicit QUIT command.
		2144
		2145	=item I don't want to destroy the handle too early - how do I wait until
		2146	all data has been written?
		2147
		2148	After writing your last bits of data, set the C<on_drain> callback
		2149	and destroy the handle in there - with the default setting of
		2150	C<low_water_mark> this will be called precisely when all data has been
		2151	written to the socket:
		2152
		2153	$handle->push_write (...);
		2154	$handle->on_drain (sub {
		2155	warn "all data submitted to the kernel\n";
		2156	undef $handle;
		2157	});
		2158
		2159	If you just want to queue some data and then signal EOF to the other side,
		2160	consider using C<< ->push_shutdown >> instead.
		2161
		2162	=item I want to contact a TLS/SSL server, I don't care about security.
		2163
		2164	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2165	simply connect to it and then create the AnyEvent::Handle with the C<tls>
		2166	parameter:
		2167
		2168	tcp_connect $host, $port, sub {
		2169	my ($fh) = @_;
		2170
		2171	my $handle = new AnyEvent::Handle
		2172	fh => $fh,
		2173	tls => "connect",
		2174	on_error => sub { ... };
		2175
		2176	$handle->push_write (...);
		2177	};
		2178
		2179	=item I want to contact a TLS/SSL server, I do care about security.
		2180
		2181	Then you should additionally enable certificate verification, including
		2182	peername verification, if the protocol you use supports it (see
		2183	L<AnyEvent::TLS>, C<verify_peername>).
		2184
		2185	E.g. for HTTPS:
		2186
		2187	tcp_connect $host, $port, sub {
		2188	my ($fh) = @_;
		2189
		2190	my $handle = new AnyEvent::Handle
		2191	fh => $fh,
		2192	peername => $host,
		2193	tls => "connect",
		2194	tls_ctx => { verify => 1, verify_peername => "https" },
		2195	...
		2196
		2197	Note that you must specify the hostname you connected to (or whatever
		2198	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2199	peername verification will be done.
		2200
		2201	The above will use the system-dependent default set of trusted CA
		2202	certificates. If you want to check against a specific CA, add the
		2203	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2204
		2205	tls_ctx => {
		2206	verify => 1,
		2207	verify_peername => "https",
		2208	ca_file => "my-ca-cert.pem",
		2209	},
		2210
		2211	=item I want to create a TLS/SSL server, how do I do that?
		2212
		2213	Well, you first need to get a server certificate and key. You have
		2214	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2215	self-signed certificate (cheap. check the search engine of your choice,
		2216	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2217	nice program for that purpose).
		2218
		2219	Then create a file with your private key (in PEM format, see
		2220	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2221	file should then look like this:
		2222
		2223	-----BEGIN RSA PRIVATE KEY-----
		2224	...header data
		2225	... lots of base64'y-stuff
		2226	-----END RSA PRIVATE KEY-----
		2227
		2228	-----BEGIN CERTIFICATE-----
		2229	... lots of base64'y-stuff
		2230	-----END CERTIFICATE-----
		2231
		2232	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2233	specify this file as C<cert_file>:
		2234
		2235	tcp_server undef, $port, sub {
		2236	my ($fh) = @_;
		2237
		2238	my $handle = new AnyEvent::Handle
		2239	fh => $fh,
		2240	tls => "accept",
		2241	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2242	...
		2243
		2244	When you have intermediate CA certificates that your clients might not
		2245	know about, just append them to the C<cert_file>.
		2246
		2247	=back
		2248
		2249
		2250	=head1 SUBCLASSING AnyEvent::Handle
		2251
		2252	In many cases, you might want to subclass AnyEvent::Handle.
		2253
		2254	To make this easier, a given version of AnyEvent::Handle uses these
		2255	conventions:
		2256
		2257	=over 4
		2258
		2259	=item * all constructor arguments become object members.
		2260
		2261	At least initially, when you pass a C<tls>-argument to the constructor it
		2262	will end up in C<< $handle->{tls} >>. Those members might be changed or
		2263	mutated later on (for example C<tls> will hold the TLS connection object).
		2264
		2265	=item * other object member names are prefixed with an C<_>.
		2266
		2267	All object members not explicitly documented (internal use) are prefixed
		2268	with an underscore character, so the remaining non-C<_>-namespace is free
		2269	for use for subclasses.
		2270
		2271	=item * all members not documented here and not prefixed with an underscore
		2272	are free to use in subclasses.
		2273
		2274	Of course, new versions of AnyEvent::Handle may introduce more "public"
		2275	member variables, but thats just life, at least it is documented.
		2276
		2277	=back
		2278
578	=head1 AUTHOR	2279	=head1 AUTHOR
579		2280
580	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	2281	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
581		2282
582	=cut	2283	=cut

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