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Revision 1.8 by root, Fri May 2 15:36:10 2008 UTC vs.
Revision 1.88 by root, Thu Aug 21 23:48:35 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	no warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent ();	6	use AnyEvent ();
7	use AnyEvent::Util ();	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
8	use Scalar::Util ();	8	use Scalar::Util ();
9	use Carp ();	9	use Carp ();
10	use Fcntl ();	10	use Fcntl ();
11	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
12		12
13	=head1 NAME	13	=head1 NAME
14		14
15	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	=cut	17	=cut
18		18
19	our $VERSION = '0.02';	19	our $VERSION = 4.233;
20		20
21	=head1 SYNOPSIS	21	=head1 SYNOPSIS
22		22
23	use AnyEvent;	23	use AnyEvent;
24	use AnyEvent::Handle;	24	use AnyEvent::Handle;
25		25
26	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
27		27
28	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
29
30	#TODO
31
32	# or use the constructor to pass the callback:
33
34	my $ae_fh2 =
35	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
36	fh => \*STDIN,	30	fh => \*STDIN,
37	on_eof => sub {	31	on_eof => sub {
38	$cv->broadcast;	32	$cv->broadcast;
39	},	33	},
40	#TODO
41	);	34	);
42		35
43	$cv->wait;	36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
		41	my ($handle, $line) = @_;
		42	warn "read line <$line>\n";
		43	$cv->send;
		44	});
		45
		46	$cv->recv;
44		47
45	=head1 DESCRIPTION	48	=head1 DESCRIPTION
46		49
47	This module is a helper module to make it easier to do event-based I/O on	50	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	51	filehandles. For utility functions for doing non-blocking connects and accepts
49	non-blocking resolves and connects).	52	on sockets see L<AnyEvent::Util>.
		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
50		56
51	In the following, when the documentation refers to of "bytes" then this	57	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	58	means characters. As sysread and syswrite are used for all I/O, their
53	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
54		60
…		…
67		73
68	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
69		75
70	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
71		77
72	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
73	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
74		81
75	=item on_error => $cb->($self) [MANDATORY]	82	=item on_eof => $cb->($handle)
76		83
77	This is the fatal error callback, that is called when a fatal error ocurs,	84	Set the callback to be called when an end-of-file condition is detected,
		85	i.e. in the case of a socket, when the other side has closed the
		86	connection cleanly.
		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the eof
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
		93	While not mandatory, it is I<highly> recommended to set an eof callback,
		94	otherwise you might end up with a closed socket while you are still
		95	waiting for data.
		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
		99
		100	=item on_error => $cb->($handle, $fatal)
		101
		102	This is the error callback, which is called when, well, some error
78	such as not being able to resolve the hostname, failure to connect or a	103	occured, such as not being able to resolve the hostname, failure to
79	read error.	104	connect or a read error.
80		105
81	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
82	called.	107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
83		111
		112	Non-fatal errors can be retried by simply returning, but it is recommended
		113	to simply ignore this parameter and instead abondon the handle object
		114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		116
84	On callback entrance, the value of C<$!> contains the opertaing system	117	On callback entrance, the value of C<$!> contains the operating system
85	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
86		119
87	=item on_eof => $cb->($self) [MANDATORY]	120	While not mandatory, it is I<highly> recommended to set this callback, as
		121	you will not be notified of errors otherwise. The default simply calls
		122	C<croak>.
88		123
89	Set the callback to be called on EOF.
90
91	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
92		125
93	This sets the default read callback, which is called when data arrives	126	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>	127	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	128	callback will only be called when at least one octet of data is in the
96	filehandle.	129	read buffer).
97		130
98	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
99	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
100		133
101	When an EOF condition is detected then AnyEvent::Handle will first try to	134	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	135	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	136	calling the C<on_eof> callback. If no progress can be made, then a fatal
104	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
105		138
106	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
107		140
108	This sets the callback that is called when the write buffer becomes empty	141	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).	142	(or when the callback is set and the buffer is empty already).
110		143
111	To append to the write buffer, use the C<< ->push_write >> method.	144	To append to the write buffer, use the C<< ->push_write >> method.
112		145
		146	This callback is useful when you don't want to put all of your write data
		147	into the queue at once, for example, when you want to write the contents
		148	of some file to the socket you might not want to read the whole file into
		149	memory and push it into the queue, but instead only read more data from
		150	the file when the write queue becomes empty.
		151
		152	=item timeout => $fractional_seconds
		153
		154	If non-zero, then this enables an "inactivity" timeout: whenever this many
		155	seconds pass without a successful read or write on the underlying file
		156	handle, the C<on_timeout> callback will be invoked (and if that one is
		157	missing, a non-fatal C<ETIMEDOUT> error will be raised).
		158
		159	Note that timeout processing is also active when you currently do not have
		160	any outstanding read or write requests: If you plan to keep the connection
		161	idle then you should disable the timout temporarily or ignore the timeout
		162	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		163	restart the timeout.
		164
		165	Zero (the default) disables this timeout.
		166
		167	=item on_timeout => $cb->($handle)
		168
		169	Called whenever the inactivity timeout passes. If you return from this
		170	callback, then the timeout will be reset as if some activity had happened,
		171	so this condition is not fatal in any way.
		172
113	=item rbuf_max => <bytes>	173	=item rbuf_max => <bytes>
114		174
115	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	175	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
116	when the read buffer ever (strictly) exceeds this size. This is useful to	176	when the read buffer ever (strictly) exceeds this size. This is useful to
117	avoid denial-of-service attacks.	177	avoid some forms of denial-of-service attacks.
118		178
119	For example, a server accepting connections from untrusted sources should	179	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	180	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	181	(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	182	amount of data without a callback ever being called as long as the line
123	isn't finished).	183	isn't finished).
124		184
		185	=item autocork => <boolean>
		186
		187	When disabled (the default), then C<push_write> will try to immediately
		188	write the data to the handle, if possible. This avoids having to register
		189	a write watcher and wait for the next event loop iteration, but can
		190	be inefficient if you write multiple small chunks (on the wire, this
		191	disadvantage is usually avoided by your kernel's nagle algorithm, see
		192	C<no_delay>, but this option can save costly syscalls).
		193
		194	When enabled, then writes will always be queued till the next event loop
		195	iteration. This is efficient when you do many small writes per iteration,
		196	but less efficient when you do a single write only per iteration (or when
		197	the write buffer often is full). It also increases write latency.
		198
		199	=item no_delay => <boolean>
		200
		201	When doing small writes on sockets, your operating system kernel might
		202	wait a bit for more data before actually sending it out. This is called
		203	the Nagle algorithm, and usually it is beneficial.
		204
		205	In some situations you want as low a delay as possible, which can be
		206	accomplishd by setting this option to a true value.
		207
		208	The default is your opertaing system's default behaviour (most likely
		209	enabled), this option explicitly enables or disables it, if possible.
		210
125	=item read_size => <bytes>	211	=item read_size => <bytes>
126		212
127	The default read block size (the amount of bytes this module will try to read	213	The default read block size (the amount of bytes this module will
128	on each [loop iteration). Default: C<4096>.	214	try to read during each loop iteration, which affects memory
		215	requirements). Default: C<8192>.
129		216
130	=item low_water_mark => <bytes>	217	=item low_water_mark => <bytes>
131		218
132	Sets the amount of bytes (default: C<0>) that make up an "empty" write	219	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	220	buffer: If the write reaches this size or gets even samller it is
134	considered empty.	221	considered empty.
135		222
		223	Sometimes it can be beneficial (for performance reasons) to add data to
		224	the write buffer before it is fully drained, but this is a rare case, as
		225	the operating system kernel usually buffers data as well, so the default
		226	is good in almost all cases.
		227
		228	=item linger => <seconds>
		229
		230	If non-zero (default: C<3600>), then the destructor of the
		231	AnyEvent::Handle object will check whether there is still outstanding
		232	write data and will install a watcher that will write this data to the
		233	socket. No errors will be reported (this mostly matches how the operating
		234	system treats outstanding data at socket close time).
		235
		236	This will not work for partial TLS data that could not be encoded
		237	yet. This data will be lost.
		238
		239	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		240
		241	When this parameter is given, it enables TLS (SSL) mode, that means
		242	AnyEvent will start a TLS handshake as soon as the conenction has been
		243	established and will transparently encrypt/decrypt data afterwards.
		244
		245	TLS mode requires Net::SSLeay to be installed (it will be loaded
		246	automatically when you try to create a TLS handle): this module doesn't
		247	have a dependency on that module, so if your module requires it, you have
		248	to add the dependency yourself.
		249
		250	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		251	C<accept>, and for the TLS client side of a connection, use C<connect>
		252	mode.
		253
		254	You can also provide your own TLS connection object, but you have
		255	to make sure that you call either C<Net::SSLeay::set_connect_state>
		256	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		257	AnyEvent::Handle.
		258
		259	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		260
		261	=item tls_ctx => $ssl_ctx
		262
		263	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
		264	(unless a connection object was specified directly). If this parameter is
		265	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		266
		267	=item json => JSON or JSON::XS object
		268
		269	This is the json coder object used by the C<json> read and write types.
		270
		271	If you don't supply it, then AnyEvent::Handle will create and use a
		272	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		273	texts.
		274
		275	Note that you are responsible to depend on the JSON module if you want to
		276	use this functionality, as AnyEvent does not have a dependency itself.
		277
		278	=item filter_r => $cb
		279
		280	=item filter_w => $cb
		281
		282	These exist, but are undocumented at this time. (They are used internally
		283	by the TLS code).
		284
136	=back	285	=back
137		286
138	=cut	287	=cut
139		288
140	sub new {	289	sub new {
…		…
144		293
145	$self->{fh} or Carp::croak "mandatory argument fh is missing";	294	$self->{fh} or Carp::croak "mandatory argument fh is missing";
146		295
147	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	296	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
148		297
149	$self->on_error ((delete $self->{on_error}) or Carp::croak "mandatory argument on_error is missing");	298	if ($self->{tls}) {
150	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	299	require Net::SSLeay;
		300	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		301	}
151		302
		303	$self->{_activity} = AnyEvent->now;
		304	$self->_timeout;
		305
152	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	306	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
153	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	307	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
		308
		309	$self->start_read
		310	if $self->{on_read};
154		311
155	$self	312	$self
156	}	313	}
157		314
158	sub _shutdown {	315	sub _shutdown {
159	my ($self) = @_;	316	my ($self) = @_;
160		317
		318	delete $self->{_tw};
161	delete $self->{rw};	319	delete $self->{_rw};
162	delete $self->{ww};	320	delete $self->{_ww};
163	delete $self->{fh};	321	delete $self->{fh};
164	}
165		322
		323	$self->stoptls;
		324
		325	delete $self->{on_read};
		326	delete $self->{_queue};
		327	}
		328
166	sub error {	329	sub _error {
167	my ($self) = @_;	330	my ($self, $errno, $fatal) = @_;
168		331
169	{
170	local $!;
171	$self->_shutdown;	332	$self->_shutdown
172	}	333	if $fatal;
173		334
		335	$! = $errno;
		336
		337	if ($self->{on_error}) {
174	$self->{on_error}($self);	338	$self->{on_error}($self, $fatal);
		339	} else {
		340	Carp::croak "AnyEvent::Handle uncaught error: $!";
		341	}
175	}	342	}
176		343
177	=item $fh = $handle->fh	344	=item $fh = $handle->fh
178		345
179	This method returns the filehandle of the L<AnyEvent::Handle> object.	346	This method returns the file handle used to create the L<AnyEvent::Handle> object.
180		347
181	=cut	348	=cut
182		349
183	sub fh { $_[0]->{fh} }	350	sub fh { $_[0]{fh} }
184		351
185	=item $handle->on_error ($cb)	352	=item $handle->on_error ($cb)
186		353
187	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	354	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
188		355
…		…
196		363
197	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).	364	Replace the current C<on_eof> callback (see the C<on_eof> constructor argument).
198		365
199	=cut	366	=cut
200		367
201	#############################################################################
202
203	sub on_eof {	368	sub on_eof {
204	$_[0]{on_eof} = $_[1];	369	$_[0]{on_eof} = $_[1];
205	}	370	}
		371
		372	=item $handle->on_timeout ($cb)
		373
		374	Replace the current C<on_timeout> callback, or disables the callback (but
		375	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		376	argument and method.
		377
		378	=cut
		379
		380	sub on_timeout {
		381	$_[0]{on_timeout} = $_[1];
		382	}
		383
		384	=item $handle->autocork ($boolean)
		385
		386	Enables or disables the current autocork behaviour (see C<autocork>
		387	constructor argument).
		388
		389	=cut
		390
		391	=item $handle->no_delay ($boolean)
		392
		393	Enables or disables the C<no_delay> setting (see constructor argument of
		394	the same name for details).
		395
		396	=cut
		397
		398	sub no_delay {
		399	$_[0]{no_delay} = $_[1];
		400
		401	eval {
		402	local $SIG{__DIE__};
		403	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		404	};
		405	}
		406
		407	#############################################################################
		408
		409	=item $handle->timeout ($seconds)
		410
		411	Configures (or disables) the inactivity timeout.
		412
		413	=cut
		414
		415	sub timeout {
		416	my ($self, $timeout) = @_;
		417
		418	$self->{timeout} = $timeout;
		419	$self->_timeout;
		420	}
		421
		422	# reset the timeout watcher, as neccessary
		423	# also check for time-outs
		424	sub _timeout {
		425	my ($self) = @_;
		426
		427	if ($self->{timeout}) {
		428	my $NOW = AnyEvent->now;
		429
		430	# when would the timeout trigger?
		431	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		432
		433	# now or in the past already?
		434	if ($after <= 0) {
		435	$self->{_activity} = $NOW;
		436
		437	if ($self->{on_timeout}) {
		438	$self->{on_timeout}($self);
		439	} else {
		440	$self->_error (&Errno::ETIMEDOUT);
		441	}
		442
		443	# callback could have changed timeout value, optimise
		444	return unless $self->{timeout};
		445
		446	# calculate new after
		447	$after = $self->{timeout};
		448	}
		449
		450	Scalar::Util::weaken $self;
		451	return unless $self; # ->error could have destroyed $self
		452
		453	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		454	delete $self->{_tw};
		455	$self->_timeout;
		456	});
		457	} else {
		458	delete $self->{_tw};
		459	}
		460	}
		461
		462	#############################################################################
		463
		464	=back
		465
		466	=head2 WRITE QUEUE
		467
		468	AnyEvent::Handle manages two queues per handle, one for writing and one
		469	for reading.
		470
		471	The write queue is very simple: you can add data to its end, and
		472	AnyEvent::Handle will automatically try to get rid of it for you.
		473
		474	When data could be written and the write buffer is shorter then the low
		475	water mark, the C<on_drain> callback will be invoked.
		476
		477	=over 4
206		478
207	=item $handle->on_drain ($cb)	479	=item $handle->on_drain ($cb)
208		480
209	Sets the C<on_drain> callback or clears it (see the description of	481	Sets the C<on_drain> callback or clears it (see the description of
210	C<on_drain> in the constructor).	482	C<on_drain> in the constructor).
…		…
226	want (only limited by the available memory), as C<AnyEvent::Handle>	498	want (only limited by the available memory), as C<AnyEvent::Handle>
227	buffers it independently of the kernel.	499	buffers it independently of the kernel.
228		500
229	=cut	501	=cut
230		502
231	sub push_write {	503	sub _drain_wbuf {
232	my ($self, $data) = @_;	504	my ($self) = @_;
233		505
234	$self->{wbuf} .= $data;	506	if (!$self->{_ww} && length $self->{wbuf}) {
235		507
236	unless ($self->{ww}) {
237	Scalar::Util::weaken $self;	508	Scalar::Util::weaken $self;
		509
238	my $cb = sub {	510	my $cb = sub {
239	my $len = syswrite $self->{fh}, $self->{wbuf};	511	my $len = syswrite $self->{fh}, $self->{wbuf};
240		512
241	if ($len > 0) {	513	if ($len >= 0) {
242	substr $self->{wbuf}, 0, $len, "";	514	substr $self->{wbuf}, 0, $len, "";
243		515
		516	$self->{_activity} = AnyEvent->now;
244		517
245	$self->{on_drain}($self)	518	$self->{on_drain}($self)
246	if $self->{low_water_mark} >= length $self->{wbuf}	519	if $self->{low_water_mark} >= length $self->{wbuf}
247	&& $self->{on_drain};	520	&& $self->{on_drain};
248		521
249	delete $self->{ww} unless length $self->{wbuf};	522	delete $self->{_ww} unless length $self->{wbuf};
250	} elsif ($! != EAGAIN && $! != EINTR) {	523	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
251	$self->error;	524	$self->_error ($!, 1);
252	}	525	}
253	};	526	};
254		527
		528	# try to write data immediately
		529	$cb->() unless $self->{autocork};
		530
		531	# if still data left in wbuf, we need to poll
255	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	532	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
256		533	if length $self->{wbuf};
257	$cb->($self);
258	};	534	};
259	}	535	}
260		536
		537	our %WH;
		538
		539	sub register_write_type($$) {
		540	$WH{$_[0]} = $_[1];
		541	}
		542
		543	sub push_write {
		544	my $self = shift;
		545
		546	if (@_ > 1) {
		547	my $type = shift;
		548
		549	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		550	->($self, @_);
		551	}
		552
		553	if ($self->{filter_w}) {
		554	$self->{filter_w}($self, \$_[0]);
		555	} else {
		556	$self->{wbuf} .= $_[0];
		557	$self->_drain_wbuf;
		558	}
		559	}
		560
		561	=item $handle->push_write (type => @args)
		562
		563	Instead of formatting your data yourself, you can also let this module do
		564	the job by specifying a type and type-specific arguments.
		565
		566	Predefined types are (if you have ideas for additional types, feel free to
		567	drop by and tell us):
		568
		569	=over 4
		570
		571	=item netstring => $string
		572
		573	Formats the given value as netstring
		574	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		575
		576	=cut
		577
		578	register_write_type netstring => sub {
		579	my ($self, $string) = @_;
		580
		581	sprintf "%d:%s,", (length $string), $string
		582	};
		583
		584	=item packstring => $format, $data
		585
		586	An octet string prefixed with an encoded length. The encoding C<$format>
		587	uses the same format as a Perl C<pack> format, but must specify a single
		588	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		589	optional C<!>, C<< < >> or C<< > >> modifier).
		590
		591	=cut
		592
		593	register_write_type packstring => sub {
		594	my ($self, $format, $string) = @_;
		595
		596	pack "$format/a*", $string
		597	};
		598
		599	=item json => $array_or_hashref
		600
		601	Encodes the given hash or array reference into a JSON object. Unless you
		602	provide your own JSON object, this means it will be encoded to JSON text
		603	in UTF-8.
		604
		605	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		606	one end of a handle and read them at the other end without using any
		607	additional framing.
		608
		609	The generated JSON text is guaranteed not to contain any newlines: While
		610	this module doesn't need delimiters after or between JSON texts to be
		611	able to read them, many other languages depend on that.
		612
		613	A simple RPC protocol that interoperates easily with others is to send
		614	JSON arrays (or objects, although arrays are usually the better choice as
		615	they mimic how function argument passing works) and a newline after each
		616	JSON text:
		617
		618	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		619	$handle->push_write ("\012");
		620
		621	An AnyEvent::Handle receiver would simply use the C<json> read type and
		622	rely on the fact that the newline will be skipped as leading whitespace:
		623
		624	$handle->push_read (json => sub { my $array = $_[1]; ... });
		625
		626	Other languages could read single lines terminated by a newline and pass
		627	this line into their JSON decoder of choice.
		628
		629	=cut
		630
		631	register_write_type json => sub {
		632	my ($self, $ref) = @_;
		633
		634	require JSON;
		635
		636	$self->{json} ? $self->{json}->encode ($ref)
		637	: JSON::encode_json ($ref)
		638	};
		639
		640	=item storable => $reference
		641
		642	Freezes the given reference using L<Storable> and writes it to the
		643	handle. Uses the C<nfreeze> format.
		644
		645	=cut
		646
		647	register_write_type storable => sub {
		648	my ($self, $ref) = @_;
		649
		650	require Storable;
		651
		652	pack "w/a*", Storable::nfreeze ($ref)
		653	};
		654
		655	=back
		656
		657	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		658
		659	This function (not method) lets you add your own types to C<push_write>.
		660	Whenever the given C<type> is used, C<push_write> will invoke the code
		661	reference with the handle object and the remaining arguments.
		662
		663	The code reference is supposed to return a single octet string that will
		664	be appended to the write buffer.
		665
		666	Note that this is a function, and all types registered this way will be
		667	global, so try to use unique names.
		668
		669	=cut
		670
261	#############################################################################	671	#############################################################################
		672
		673	=back
		674
		675	=head2 READ QUEUE
		676
		677	AnyEvent::Handle manages two queues per handle, one for writing and one
		678	for reading.
		679
		680	The read queue is more complex than the write queue. It can be used in two
		681	ways, the "simple" way, using only C<on_read> and the "complex" way, using
		682	a queue.
		683
		684	In the simple case, you just install an C<on_read> callback and whenever
		685	new data arrives, it will be called. You can then remove some data (if
		686	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
		687	leave the data there if you want to accumulate more (e.g. when only a
		688	partial message has been received so far).
		689
		690	In the more complex case, you want to queue multiple callbacks. In this
		691	case, AnyEvent::Handle will call the first queued callback each time new
		692	data arrives (also the first time it is queued) and removes it when it has
		693	done its job (see C<push_read>, below).
		694
		695	This way you can, for example, push three line-reads, followed by reading
		696	a chunk of data, and AnyEvent::Handle will execute them in order.
		697
		698	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
		699	the specified number of bytes which give an XML datagram.
		700
		701	# in the default state, expect some header bytes
		702	$handle->on_read (sub {
		703	# some data is here, now queue the length-header-read (4 octets)
		704	shift->unshift_read (chunk => 4, sub {
		705	# header arrived, decode
		706	my $len = unpack "N", $_[1];
		707
		708	# now read the payload
		709	shift->unshift_read (chunk => $len, sub {
		710	my $xml = $_[1];
		711	# handle xml
		712	});
		713	});
		714	});
		715
		716	Example 2: Implement a client for a protocol that replies either with "OK"
		717	and another line or "ERROR" for the first request that is sent, and 64
		718	bytes for the second request. Due to the availability of a queue, we can
		719	just pipeline sending both requests and manipulate the queue as necessary
		720	in the callbacks.
		721
		722	When the first callback is called and sees an "OK" response, it will
		723	C<unshift> another line-read. This line-read will be queued I<before> the
		724	64-byte chunk callback.
		725
		726	# request one, returns either "OK + extra line" or "ERROR"
		727	$handle->push_write ("request 1\015\012");
		728
		729	# we expect "ERROR" or "OK" as response, so push a line read
		730	$handle->push_read (line => sub {
		731	# if we got an "OK", we have to _prepend_ another line,
		732	# so it will be read before the second request reads its 64 bytes
		733	# which are already in the queue when this callback is called
		734	# we don't do this in case we got an error
		735	if ($_[1] eq "OK") {
		736	$_[0]->unshift_read (line => sub {
		737	my $response = $_[1];
		738	...
		739	});
		740	}
		741	});
		742
		743	# request two, simply returns 64 octets
		744	$handle->push_write ("request 2\015\012");
		745
		746	# simply read 64 bytes, always
		747	$handle->push_read (chunk => 64, sub {
		748	my $response = $_[1];
		749	...
		750	});
		751
		752	=over 4
		753
		754	=cut
262		755
263	sub _drain_rbuf {	756	sub _drain_rbuf {
264	my ($self) = @_;	757	my ($self) = @_;
265		758
266	return if exists $self->{in_drain};
267	local $self->{in_drain} = 1;	759	local $self->{_in_drain} = 1;
268		760
		761	if (
		762	defined $self->{rbuf_max}
		763	&& $self->{rbuf_max} < length $self->{rbuf}
		764	) {
		765	$self->_error (&Errno::ENOSPC, 1), return;
		766	}
		767
		768	while () {
269	while (my $len = length $self->{rbuf}) {	769	my $len = length $self->{rbuf};
270	no strict 'refs';	770
271	if (@{ $self->{queue} }) {	771	if (my $cb = shift @{ $self->{_queue} }) {
272	if ($self->{queue}[0]($self)) {	772	unless ($cb->($self)) {
273	shift @{ $self->{queue} };
274	} elsif ($self->{eof}) {	773	if ($self->{_eof}) {
275	# no progress can be made (not enough data and no data forthcoming)	774	# no progress can be made (not enough data and no data forthcoming)
276	$! = &Errno::EPIPE; return $self->error;	775	$self->_error (&Errno::EPIPE, 1), return;
277	} else {	776	}
		777
		778	unshift @{ $self->{_queue} }, $cb;
278	return;	779	last;
279	}	780	}
280	} elsif ($self->{on_read}) {	781	} elsif ($self->{on_read}) {
		782	last unless $len;
		783
281	$self->{on_read}($self);	784	$self->{on_read}($self);
282		785
283	if (	786	if (
284	$self->{eof} # if no further data will arrive
285	&& $len == length $self->{rbuf} # and no data has been consumed	787	$len == length $self->{rbuf} # if no data has been consumed
286	&& !@{ $self->{queue} } # and the queue is still empty	788	&& !@{ $self->{_queue} } # and the queue is still empty
287	&& $self->{on_read} # and we still want to read data	789	&& $self->{on_read} # but we still have on_read
288	) {	790	) {
		791	# no further data will arrive
289	# then no progress can be made	792	# so no progress can be made
290	$! = &Errno::EPIPE; return $self->error;	793	$self->_error (&Errno::EPIPE, 1), return
		794	if $self->{_eof};
		795
		796	last; # more data might arrive
291	}	797	}
292	} else {	798	} else {
293	# read side becomes idle	799	# read side becomes idle
294	delete $self->{rw};	800	delete $self->{_rw};
295	return;	801	last;
296	}	802	}
297	}	803	}
298		804
299	if ($self->{eof}) {	805	if ($self->{_eof}) {
300	$self->_shutdown;	806	if ($self->{on_eof}) {
301	$self->{on_eof}($self);	807	$self->{on_eof}($self)
		808	} else {
		809	$self->_error (0, 1);
		810	}
		811	}
		812
		813	# may need to restart read watcher
		814	unless ($self->{_rw}) {
		815	$self->start_read
		816	if $self->{on_read} || @{ $self->{_queue} };
302	}	817	}
303	}	818	}
304		819
305	=item $handle->on_read ($cb)	820	=item $handle->on_read ($cb)
306		821
…		…
312		827
313	sub on_read {	828	sub on_read {
314	my ($self, $cb) = @_;	829	my ($self, $cb) = @_;
315		830
316	$self->{on_read} = $cb;	831	$self->{on_read} = $cb;
317		832	$self->_drain_rbuf if $cb && !$self->{_in_drain};
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;
340	});
341	}
342	}	833	}
343		834
344	=item $handle->rbuf	835	=item $handle->rbuf
345		836
346	Returns the read buffer (as a modifiable lvalue).	837	Returns the read buffer (as a modifiable lvalue).
…		…
365	Append the given callback to the end of the queue (C<push_read>) or	856	Append the given callback to the end of the queue (C<push_read>) or
366	prepend it (C<unshift_read>).	857	prepend it (C<unshift_read>).
367		858
368	The callback is called each time some additional read data arrives.	859	The callback is called each time some additional read data arrives.
369		860
370	It must check wether enough data is in the read buffer already.	861	It must check whether enough data is in the read buffer already.
371		862
372	If not enough data is available, it must return the empty list or a false	863	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	864	value, in which case it will be called repeatedly until enough data is
374	available (or an error condition is detected).	865	available (or an error condition is detected).
375		866
…		…
377	interested in (which can be none at all) and return a true value. After returning	868	interested in (which can be none at all) and return a true value. After returning
378	true, it will be removed from the queue.	869	true, it will be removed from the queue.
379		870
380	=cut	871	=cut
381		872
		873	our %RH;
		874
		875	sub register_read_type($$) {
		876	$RH{$_[0]} = $_[1];
		877	}
		878
382	sub push_read {	879	sub push_read {
383	my ($self, $cb) = @_;	880	my $self = shift;
		881	my $cb = pop;
384		882
		883	if (@_) {
		884	my $type = shift;
		885
		886	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		887	->($self, $cb, @_);
		888	}
		889
385	push @{ $self->{queue} }, $cb;	890	push @{ $self->{_queue} }, $cb;
386	$self->_drain_rbuf;	891	$self->_drain_rbuf unless $self->{_in_drain};
387	}	892	}
388		893
389	sub unshift_read {	894	sub unshift_read {
390	my ($self, $cb) = @_;	895	my $self = shift;
		896	my $cb = pop;
391		897
		898	if (@_) {
		899	my $type = shift;
		900
		901	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		902	->($self, $cb, @_);
		903	}
		904
		905
392	push @{ $self->{queue} }, $cb;	906	unshift @{ $self->{_queue} }, $cb;
393	$self->_drain_rbuf;	907	$self->_drain_rbuf unless $self->{_in_drain};
394	}	908	}
395		909
396	=item $handle->push_read_chunk ($len, $cb->($self, $data))	910	=item $handle->push_read (type => @args, $cb)
397		911
398	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	912	=item $handle->unshift_read (type => @args, $cb)
399		913
400	Append the given callback to the end of the queue (C<push_read_chunk>) or	914	Instead of providing a callback that parses the data itself you can chose
401	prepend it (C<unshift_read_chunk>).	915	between a number of predefined parsing formats, for chunks of data, lines
		916	etc.
402		917
403	The callback will be called only once C<$len> bytes have been read, and	918	Predefined types are (if you have ideas for additional types, feel free to
404	these C<$len> bytes will be passed to the callback.	919	drop by and tell us):
405		920
406	=cut	921	=over 4
407		922
408	sub _read_chunk($$) {	923	=item chunk => $octets, $cb->($handle, $data)
409	my ($len, $cb) = @_;	924
		925	Invoke the callback only once C<$octets> bytes have been read. Pass the
		926	data read to the callback. The callback will never be called with less
		927	data.
		928
		929	Example: read 2 bytes.
		930
		931	$handle->push_read (chunk => 2, sub {
		932	warn "yay ", unpack "H*", $_[1];
		933	});
		934
		935	=cut
		936
		937	register_read_type chunk => sub {
		938	my ($self, $cb, $len) = @_;
410		939
411	sub {	940	sub {
412	$len <= length $_[0]{rbuf} or return;	941	$len <= length $_[0]{rbuf} or return;
413	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	942	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
414	1	943	1
415	}	944	}
416	}	945	};
417		946
418	sub push_read_chunk {	947	=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		948
438	The callback will be called only once a full line (including the end of	949	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	950	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	951	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>).	952	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	963	Partial lines at the end of the stream will never be returned, as they are
453	not marked by the end of line marker.	964	not marked by the end of line marker.
454		965
455	=cut	966	=cut
456		967
457	sub _read_line($$) {	968	register_read_type line => sub {
458	my $cb = pop;	969	my ($self, $cb, $eol) = @_;
459	my $eol = @_ ? shift : qr|(\015?\012)|;
460	my $pos;
461		970
		971	if (@_ < 3) {
		972	# this is more than twice as fast as the generic code below
		973	sub {
		974	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		975
		976	$cb->($_[0], $1, $2);
		977	1
		978	}
		979	} else {
462	$eol = qr|(\Q$eol\E)| unless ref $eol;	980	$eol = quotemeta $eol unless ref $eol;
463	$eol = qr|^(.*?)($eol)|;	981	$eol = qr|^(.*?)($eol)|s;
		982
		983	sub {
		984	$_[0]{rbuf} =~ s/$eol// or return;
		985
		986	$cb->($_[0], $1, $2);
		987	1
		988	}
		989	}
		990	};
		991
		992	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		993
		994	Makes a regex match against the regex object C<$accept> and returns
		995	everything up to and including the match.
		996
		997	Example: read a single line terminated by '\n'.
		998
		999	$handle->push_read (regex => qr<\n>, sub { ... });
		1000
		1001	If C<$reject> is given and not undef, then it determines when the data is
		1002	to be rejected: it is matched against the data when the C<$accept> regex
		1003	does not match and generates an C<EBADMSG> error when it matches. This is
		1004	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1005	receive buffer overflow).
		1006
		1007	Example: expect a single decimal number followed by whitespace, reject
		1008	anything else (not the use of an anchor).
		1009
		1010	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1011
		1012	If C<$skip> is given and not C<undef>, then it will be matched against
		1013	the receive buffer when neither C<$accept> nor C<$reject> match,
		1014	and everything preceding and including the match will be accepted
		1015	unconditionally. This is useful to skip large amounts of data that you
		1016	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1017	have to start matching from the beginning. This is purely an optimisation
		1018	and is usually worth only when you expect more than a few kilobytes.
		1019
		1020	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1021	expect the header to be very large (it isn't in practise, but...), we use
		1022	a skip regex to skip initial portions. The skip regex is tricky in that
		1023	it only accepts something not ending in either \015 or \012, as these are
		1024	required for the accept regex.
		1025
		1026	$handle->push_read (regex =>
		1027	qr<\015\012\015\012>,
		1028	undef, # no reject
		1029	qr<^.*[^\015\012]>,
		1030	sub { ... });
		1031
		1032	=cut
		1033
		1034	register_read_type regex => sub {
		1035	my ($self, $cb, $accept, $reject, $skip) = @_;
		1036
		1037	my $data;
		1038	my $rbuf = \$self->{rbuf};
464		1039
465	sub {	1040	sub {
466	$_[0]{rbuf} =~ s/$eol// or return;	1041	# accept
		1042	if ($$rbuf =~ $accept) {
		1043	$data .= substr $$rbuf, 0, $+[0], "";
		1044	$cb->($self, $data);
		1045	return 1;
		1046	}
		1047
		1048	# reject
		1049	if ($reject && $$rbuf =~ $reject) {
		1050	$self->_error (&Errno::EBADMSG);
		1051	}
467		1052
468	$cb->($1, $2);	1053	# skip
		1054	if ($skip && $$rbuf =~ $skip) {
		1055	$data .= substr $$rbuf, 0, $+[0], "";
		1056	}
		1057
		1058	()
		1059	}
		1060	};
		1061
		1062	=item netstring => $cb->($handle, $string)
		1063
		1064	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1065
		1066	Throws an error with C<$!> set to EBADMSG on format violations.
		1067
		1068	=cut
		1069
		1070	register_read_type netstring => sub {
		1071	my ($self, $cb) = @_;
		1072
		1073	sub {
		1074	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1075	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1076	$self->_error (&Errno::EBADMSG);
		1077	}
		1078	return;
		1079	}
		1080
		1081	my $len = $1;
		1082
		1083	$self->unshift_read (chunk => $len, sub {
		1084	my $string = $_[1];
		1085	$_[0]->unshift_read (chunk => 1, sub {
		1086	if ($_[1] eq ",") {
		1087	$cb->($_[0], $string);
		1088	} else {
		1089	$self->_error (&Errno::EBADMSG);
		1090	}
		1091	});
		1092	});
		1093
469	1	1094	1
470	}	1095	}
471	}	1096	};
472		1097
473	sub push_read_line {	1098	=item packstring => $format, $cb->($handle, $string)
		1099
		1100	An octet string prefixed with an encoded length. The encoding C<$format>
		1101	uses the same format as a Perl C<pack> format, but must specify a single
		1102	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1103	optional C<!>, C<< < >> or C<< > >> modifier).
		1104
		1105	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1106
		1107	Example: read a block of data prefixed by its length in BER-encoded
		1108	format (very efficient).
		1109
		1110	$handle->push_read (packstring => "w", sub {
		1111	my ($handle, $data) = @_;
		1112	});
		1113
		1114	=cut
		1115
		1116	register_read_type packstring => sub {
		1117	my ($self, $cb, $format) = @_;
		1118
		1119	sub {
		1120	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1121	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1122	or return;
		1123
		1124	$format = length pack $format, $len;
		1125
		1126	# bypass unshift if we already have the remaining chunk
		1127	if ($format + $len <= length $_[0]{rbuf}) {
		1128	my $data = substr $_[0]{rbuf}, $format, $len;
		1129	substr $_[0]{rbuf}, 0, $format + $len, "";
		1130	$cb->($_[0], $data);
		1131	} else {
		1132	# remove prefix
		1133	substr $_[0]{rbuf}, 0, $format, "";
		1134
		1135	# read remaining chunk
		1136	$_[0]->unshift_read (chunk => $len, $cb);
		1137	}
		1138
		1139	1
		1140	}
		1141	};
		1142
		1143	=item json => $cb->($handle, $hash_or_arrayref)
		1144
		1145	Reads a JSON object or array, decodes it and passes it to the callback.
		1146
		1147	If a C<json> object was passed to the constructor, then that will be used
		1148	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1149
		1150	This read type uses the incremental parser available with JSON version
		1151	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1152	dependency on your own: this module will load the JSON module, but
		1153	AnyEvent does not depend on it itself.
		1154
		1155	Since JSON texts are fully self-delimiting, the C<json> read and write
		1156	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1157	the C<json> write type description, above, for an actual example.
		1158
		1159	=cut
		1160
		1161	register_read_type json => sub {
		1162	my ($self, $cb) = @_;
		1163
		1164	require JSON;
		1165
		1166	my $data;
		1167	my $rbuf = \$self->{rbuf};
		1168
		1169	my $json = $self->{json} ||= JSON->new->utf8;
		1170
		1171	sub {
		1172	my $ref = $json->incr_parse ($self->{rbuf});
		1173
		1174	if ($ref) {
		1175	$self->{rbuf} = $json->incr_text;
		1176	$json->incr_text = "";
		1177	$cb->($self, $ref);
		1178
		1179	1
		1180	} else {
		1181	$self->{rbuf} = "";
		1182	()
		1183	}
		1184	}
		1185	};
		1186
		1187	=item storable => $cb->($handle, $ref)
		1188
		1189	Deserialises a L<Storable> frozen representation as written by the
		1190	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1191	data).
		1192
		1193	Raises C<EBADMSG> error if the data could not be decoded.
		1194
		1195	=cut
		1196
		1197	register_read_type storable => sub {
		1198	my ($self, $cb) = @_;
		1199
		1200	require Storable;
		1201
		1202	sub {
		1203	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1204	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1205	or return;
		1206
		1207	my $format = length pack "w", $len;
		1208
		1209	# bypass unshift if we already have the remaining chunk
		1210	if ($format + $len <= length $_[0]{rbuf}) {
		1211	my $data = substr $_[0]{rbuf}, $format, $len;
		1212	substr $_[0]{rbuf}, 0, $format + $len, "";
		1213	$cb->($_[0], Storable::thaw ($data));
		1214	} else {
		1215	# remove prefix
		1216	substr $_[0]{rbuf}, 0, $format, "";
		1217
		1218	# read remaining chunk
		1219	$_[0]->unshift_read (chunk => $len, sub {
		1220	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1221	$cb->($_[0], $ref);
		1222	} else {
		1223	$self->_error (&Errno::EBADMSG);
		1224	}
		1225	});
		1226	}
		1227
		1228	1
		1229	}
		1230	};
		1231
		1232	=back
		1233
		1234	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1235
		1236	This function (not method) lets you add your own types to C<push_read>.
		1237
		1238	Whenever the given C<type> is used, C<push_read> will invoke the code
		1239	reference with the handle object, the callback and the remaining
		1240	arguments.
		1241
		1242	The code reference is supposed to return a callback (usually a closure)
		1243	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1244
		1245	It should invoke the passed callback when it is done reading (remember to
		1246	pass C<$handle> as first argument as all other callbacks do that).
		1247
		1248	Note that this is a function, and all types registered this way will be
		1249	global, so try to use unique names.
		1250
		1251	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1252	search for C<register_read_type>)).
		1253
		1254	=item $handle->stop_read
		1255
		1256	=item $handle->start_read
		1257
		1258	In rare cases you actually do not want to read anything from the
		1259	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
		1260	any queued callbacks will be executed then. To start reading again, call
		1261	C<start_read>.
		1262
		1263	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1264	you change the C<on_read> callback or push/unshift a read callback, and it
		1265	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1266	there are any read requests in the queue.
		1267
		1268	=cut
		1269
		1270	sub stop_read {
		1271	my ($self) = @_;
		1272
		1273	delete $self->{_rw};
		1274	}
		1275
		1276	sub start_read {
		1277	my ($self) = @_;
		1278
		1279	unless ($self->{_rw} || $self->{_eof}) {
		1280	Scalar::Util::weaken $self;
		1281
		1282	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1283	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
		1284	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
		1285
		1286	if ($len > 0) {
		1287	$self->{_activity} = AnyEvent->now;
		1288
		1289	$self->{filter_r}
		1290	? $self->{filter_r}($self, $rbuf)
		1291	: $self->{_in_drain} || $self->_drain_rbuf;
		1292
		1293	} elsif (defined $len) {
		1294	delete $self->{_rw};
		1295	$self->{_eof} = 1;
		1296	$self->_drain_rbuf unless $self->{_in_drain};
		1297
		1298	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
		1299	return $self->_error ($!, 1);
		1300	}
		1301	});
		1302	}
		1303	}
		1304
		1305	sub _dotls {
		1306	my ($self) = @_;
		1307
		1308	my $buf;
		1309
		1310	if (length $self->{_tls_wbuf}) {
		1311	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1312	substr $self->{_tls_wbuf}, 0, $len, "";
		1313	}
		1314	}
		1315
		1316	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1317	$self->{wbuf} .= $buf;
		1318	$self->_drain_wbuf;
		1319	}
		1320
		1321	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1322	if (length $buf) {
		1323	$self->{rbuf} .= $buf;
		1324	$self->_drain_rbuf unless $self->{_in_drain};
		1325	} else {
		1326	# let's treat SSL-eof as we treat normal EOF
		1327	$self->{_eof} = 1;
		1328	$self->_shutdown;
		1329	return;
		1330	}
		1331	}
		1332
		1333	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1334
		1335	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1336	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1337	return $self->_error ($!, 1);
		1338	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1339	return $self->_error (&Errno::EIO, 1);
		1340	}
		1341
		1342	# all others are fine for our purposes
		1343	}
		1344	}
		1345
		1346	=item $handle->starttls ($tls[, $tls_ctx])
		1347
		1348	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1349	object is created, you can also do that at a later time by calling
		1350	C<starttls>.
		1351
		1352	The first argument is the same as the C<tls> constructor argument (either
		1353	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1354
		1355	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1356	used when AnyEvent::Handle has to create its own TLS connection object.
		1357
		1358	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1359	call and can be used or changed to your liking. Note that the handshake
		1360	might have already started when this function returns.
		1361
		1362	=cut
		1363
		1364	sub starttls {
		1365	my ($self, $ssl, $ctx) = @_;
		1366
		1367	$self->stoptls;
		1368
		1369	if ($ssl eq "accept") {
		1370	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1371	Net::SSLeay::set_accept_state ($ssl);
		1372	} elsif ($ssl eq "connect") {
		1373	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1374	Net::SSLeay::set_connect_state ($ssl);
		1375	}
		1376
		1377	$self->{tls} = $ssl;
		1378
		1379	# basically, this is deep magic (because SSL_read should have the same issues)
		1380	# but the openssl maintainers basically said: "trust us, it just works".
		1381	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1382	# and mismaintained ssleay-module doesn't even offer them).
		1383	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1384	#
		1385	# in short: this is a mess.
		1386	#
		1387	# note that we do not try to kepe the length constant between writes as we are required to do.
		1388	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1389	# and we drive openssl fully in blocking mode here.
		1390	Net::SSLeay::CTX_set_mode ($self->{tls},
		1391	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1392	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1393
		1394	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1395	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1396
		1397	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1398
		1399	$self->{filter_w} = sub {
		1400	$_[0]{_tls_wbuf} .= ${$_[1]};
		1401	&_dotls;
		1402	};
		1403	$self->{filter_r} = sub {
		1404	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1405	&_dotls;
		1406	};
		1407	}
		1408
		1409	=item $handle->stoptls
		1410
		1411	Destroys the SSL connection, if any. Partial read or write data will be
		1412	lost.
		1413
		1414	=cut
		1415
		1416	sub stoptls {
		1417	my ($self) = @_;
		1418
		1419	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1420
		1421	delete $self->{_rbio};
		1422	delete $self->{_wbio};
		1423	delete $self->{_tls_wbuf};
		1424	delete $self->{filter_r};
		1425	delete $self->{filter_w};
		1426	}
		1427
		1428	sub DESTROY {
474	my $self = shift;	1429	my $self = shift;
475		1430
476	$self->push_read (&_read_line);	1431	$self->stoptls;
477	}
478		1432
479	sub unshift_read_line {	1433	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
480	my $self = shift;
481		1434
482	$self->unshift_read (&_read_line);	1435	if ($linger && length $self->{wbuf}) {
		1436	my $fh = delete $self->{fh};
		1437	my $wbuf = delete $self->{wbuf};
		1438
		1439	my @linger;
		1440
		1441	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1442	my $len = syswrite $fh, $wbuf, length $wbuf;
		1443
		1444	if ($len > 0) {
		1445	substr $wbuf, 0, $len, "";
		1446	} else {
		1447	@linger = (); # end
		1448	}
		1449	});
		1450	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1451	@linger = ();
		1452	});
		1453	}
		1454	}
		1455
		1456	=item AnyEvent::Handle::TLS_CTX
		1457
		1458	This function creates and returns the Net::SSLeay::CTX object used by
		1459	default for TLS mode.
		1460
		1461	The context is created like this:
		1462
		1463	Net::SSLeay::load_error_strings;
		1464	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1465	Net::SSLeay::randomize;
		1466
		1467	my $CTX = Net::SSLeay::CTX_new;
		1468
		1469	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1470
		1471	=cut
		1472
		1473	our $TLS_CTX;
		1474
		1475	sub TLS_CTX() {
		1476	$TLS_CTX || do {
		1477	require Net::SSLeay;
		1478
		1479	Net::SSLeay::load_error_strings ();
		1480	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1481	Net::SSLeay::randomize ();
		1482
		1483	$TLS_CTX = Net::SSLeay::CTX_new ();
		1484
		1485	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1486
		1487	$TLS_CTX
		1488	}
483	}	1489	}
484		1490
485	=back	1491	=back
486		1492
		1493	=head1 SUBCLASSING AnyEvent::Handle
		1494
		1495	In many cases, you might want to subclass AnyEvent::Handle.
		1496
		1497	To make this easier, a given version of AnyEvent::Handle uses these
		1498	conventions:
		1499
		1500	=over 4
		1501
		1502	=item * all constructor arguments become object members.
		1503
		1504	At least initially, when you pass a C<tls>-argument to the constructor it
		1505	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1506	mutated later on (for example C<tls> will hold the TLS connection object).
		1507
		1508	=item * other object member names are prefixed with an C<_>.
		1509
		1510	All object members not explicitly documented (internal use) are prefixed
		1511	with an underscore character, so the remaining non-C<_>-namespace is free
		1512	for use for subclasses.
		1513
		1514	=item * all members not documented here and not prefixed with an underscore
		1515	are free to use in subclasses.
		1516
		1517	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1518	member variables, but thats just life, at least it is documented.
		1519
		1520	=back
		1521
487	=head1 AUTHOR	1522	=head1 AUTHOR
488		1523
489	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1524	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
490		1525
491	=cut	1526	=cut

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