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Revision 1.11 by root, Sun May 11 17:54:13 2008 UTC vs.
Revision 1.85 by root, Thu Aug 21 19:53:19 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 = 4.232;
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_eof => $cb->($self) [MANDATORY]
76
77	Set the callback to be called on EOF.
78
79	=item on_error => $cb->($self)	82	=item on_eof => $cb->($handle)
80		83
		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, $fatal)
		101
81	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
82	ocurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
83	or a read error.	104	connect or a read error.
84		105
85	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
86	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.
		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>).
87		116
88	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
89	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
90		119
91	While not mandatory, it is I<highly> recommended to set this callback, as	120	While not mandatory, it is I<highly> recommended to set this callback, as
92	you will not be notified of errors otherwise. The default simply calls	121	you will not be notified of errors otherwise. The default simply calls
93	die.	122	C<croak>.
94		123
95	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
96		125
97	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
98	and no read request is in the queue.	127	and no read request is in the queue (unlike read queue callbacks, this
		128	callback will only be called when at least one octet of data is in the
		129	read buffer).
99		130
100	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 >>
101	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
102		133
103	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
104	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
105	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
106	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
107		138
108	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
109		140
110	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
111	(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).
112		143
113	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.
		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, an 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.
		163
		164	Zero (the default) disables this timeout.
		165
		166	=item on_timeout => $cb->($handle)
		167
		168	Called whenever the inactivity timeout passes. If you return from this
		169	callback, then the timeout will be reset as if some activity had happened,
		170	so this condition is not fatal in any way.
114		171
115	=item rbuf_max => <bytes>	172	=item rbuf_max => <bytes>
116		173
117	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	174	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
118	when the read buffer ever (strictly) exceeds this size. This is useful to	175	when the read buffer ever (strictly) exceeds this size. This is useful to
…		…
122	be configured to accept only so-and-so much data that it cannot act on	179	be configured to accept only so-and-so much data that it cannot act on
123	(for example, when expecting a line, an attacker could send an unlimited	180	(for example, when expecting a line, an attacker could send an unlimited
124	amount of data without a callback ever being called as long as the line	181	amount of data without a callback ever being called as long as the line
125	isn't finished).	182	isn't finished).
126		183
		184	=item autocork => <boolean>
		185
		186	When disabled (the default), then C<push_write> will try to immediately
		187	write the data to the handle if possible. This avoids having to register
		188	a write watcher and wait for the next event loop iteration, but can be
		189	inefficient if you write multiple small chunks (this disadvantage is
		190	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		191
		192	When enabled, then writes will always be queued till the next event loop
		193	iteration. This is efficient when you do many small writes per iteration,
		194	but less efficient when you do a single write only.
		195
		196	=item no_delay => <boolean>
		197
		198	When doing small writes on sockets, your operating system kernel might
		199	wait a bit for more data before actually sending it out. This is called
		200	the Nagle algorithm, and usually it is beneficial.
		201
		202	In some situations you want as low a delay as possible, which cna be
		203	accomplishd by setting this option to true.
		204
		205	The default is your opertaing system's default behaviour, this option
		206	explicitly enables or disables it, if possible.
		207
127	=item read_size => <bytes>	208	=item read_size => <bytes>
128		209
129	The default read block size (the amount of bytes this module will try to read	210	The default read block size (the amount of bytes this module will try to read
130	on each [loop iteration). Default: C<4096>.	211	during each (loop iteration). Default: C<8192>.
131		212
132	=item low_water_mark => <bytes>	213	=item low_water_mark => <bytes>
133		214
134	Sets the amount of bytes (default: C<0>) that make up an "empty" write	215	Sets the amount of bytes (default: C<0>) that make up an "empty" write
135	buffer: If the write reaches this size or gets even samller it is	216	buffer: If the write reaches this size or gets even samller it is
136	considered empty.	217	considered empty.
137		218
		219	=item linger => <seconds>
		220
		221	If non-zero (default: C<3600>), then the destructor of the
		222	AnyEvent::Handle object will check wether there is still outstanding write
		223	data and will install a watcher that will write out this data. No errors
		224	will be reported (this mostly matches how the operating system treats
		225	outstanding data at socket close time).
		226
		227	This will not work for partial TLS data that could not yet been
		228	encoded. This data will be lost.
		229
		230	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		231
		232	When this parameter is given, it enables TLS (SSL) mode, that means
		233	AnyEvent will start a TLS handshake and will transparently encrypt/decrypt
		234	data.
		235
		236	TLS mode requires Net::SSLeay to be installed (it will be loaded
		237	automatically when you try to create a TLS handle).
		238
		239	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		240	C<accept>, and for the TLS client side of a connection, use C<connect>
		241	mode.
		242
		243	You can also provide your own TLS connection object, but you have
		244	to make sure that you call either C<Net::SSLeay::set_connect_state>
		245	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		246	AnyEvent::Handle.
		247
		248	See the C<starttls> method for when need to start TLS negotiation later.
		249
		250	=item tls_ctx => $ssl_ctx
		251
		252	Use the given Net::SSLeay::CTX object to create the new TLS connection
		253	(unless a connection object was specified directly). If this parameter is
		254	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		255
		256	=item json => JSON or JSON::XS object
		257
		258	This is the json coder object used by the C<json> read and write types.
		259
		260	If you don't supply it, then AnyEvent::Handle will create and use a
		261	suitable one, which will write and expect UTF-8 encoded JSON texts.
		262
		263	Note that you are responsible to depend on the JSON module if you want to
		264	use this functionality, as AnyEvent does not have a dependency itself.
		265
		266	=item filter_r => $cb
		267
		268	=item filter_w => $cb
		269
		270	These exist, but are undocumented at this time.
		271
138	=back	272	=back
139		273
140	=cut	274	=cut
141		275
142	sub new {	276	sub new {
…		…
146		280
147	$self->{fh} or Carp::croak "mandatory argument fh is missing";	281	$self->{fh} or Carp::croak "mandatory argument fh is missing";
148		282
149	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	283	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
150		284
151	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	285	if ($self->{tls}) {
		286	require Net::SSLeay;
		287	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		288	}
152		289
153	$self->on_error (delete $self->{on_error}) if $self->{on_error};	290	$self->{_activity} = AnyEvent->now;
		291	$self->_timeout;
		292
154	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	293	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
155	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	294	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
156		295
157	$self->start_read;	296	$self->start_read
		297	if $self->{on_read};
158		298
159	$self	299	$self
160	}	300	}
161		301
162	sub _shutdown {	302	sub _shutdown {
163	my ($self) = @_;	303	my ($self) = @_;
164		304
		305	delete $self->{_tw};
165	delete $self->{rw};	306	delete $self->{_rw};
166	delete $self->{ww};	307	delete $self->{_ww};
167	delete $self->{fh};	308	delete $self->{fh};
168	}
169		309
		310	$self->stoptls;
		311
		312	delete $self->{on_read};
		313	delete $self->{_queue};
		314	}
		315
170	sub error {	316	sub _error {
171	my ($self) = @_;	317	my ($self, $errno, $fatal) = @_;
172		318
173	{
174	local $!;
175	$self->_shutdown;	319	$self->_shutdown
176	}	320	if $fatal;
		321
		322	$! = $errno;
177		323
178	if ($self->{on_error}) {	324	if ($self->{on_error}) {
179	$self->{on_error}($self);	325	$self->{on_error}($self, $fatal);
180	} else {	326	} else {
181	die "AnyEvent::Handle uncaught fatal error: $!";	327	Carp::croak "AnyEvent::Handle uncaught error: $!";
182	}	328	}
183	}	329	}
184		330
185	=item $fh = $handle->fh	331	=item $fh = $handle->fh
186		332
187	This method returns the filehandle of the L<AnyEvent::Handle> object.	333	This method returns the file handle of the L<AnyEvent::Handle> object.
188		334
189	=cut	335	=cut
190		336
191	sub fh { $_[0]->{fh} }	337	sub fh { $_[0]{fh} }
192		338
193	=item $handle->on_error ($cb)	339	=item $handle->on_error ($cb)
194		340
195	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	341	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
196		342
…		…
208		354
209	sub on_eof {	355	sub on_eof {
210	$_[0]{on_eof} = $_[1];	356	$_[0]{on_eof} = $_[1];
211	}	357	}
212		358
		359	=item $handle->on_timeout ($cb)
		360
		361	Replace the current C<on_timeout> callback, or disables the callback
		362	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		363	argument.
		364
		365	=cut
		366
		367	sub on_timeout {
		368	$_[0]{on_timeout} = $_[1];
		369	}
		370
		371	=item $handle->autocork ($boolean)
		372
		373	Enables or disables the current autocork behaviour (see C<autocork>
		374	constructor argument).
		375
		376	=cut
		377
		378	=item $handle->no_delay ($boolean)
		379
		380	Enables or disables the C<no_delay> setting (see constructor argument of
		381	the same name for details).
		382
		383	=cut
		384
		385	sub no_delay {
		386	$_[0]{no_delay} = $_[1];
		387
		388	eval {
		389	local $SIG{__DIE__};
		390	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		391	};
		392	}
		393
		394	#############################################################################
		395
		396	=item $handle->timeout ($seconds)
		397
		398	Configures (or disables) the inactivity timeout.
		399
		400	=cut
		401
		402	sub timeout {
		403	my ($self, $timeout) = @_;
		404
		405	$self->{timeout} = $timeout;
		406	$self->_timeout;
		407	}
		408
		409	# reset the timeout watcher, as neccessary
		410	# also check for time-outs
		411	sub _timeout {
		412	my ($self) = @_;
		413
		414	if ($self->{timeout}) {
		415	my $NOW = AnyEvent->now;
		416
		417	# when would the timeout trigger?
		418	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		419
		420	# now or in the past already?
		421	if ($after <= 0) {
		422	$self->{_activity} = $NOW;
		423
		424	if ($self->{on_timeout}) {
		425	$self->{on_timeout}($self);
		426	} else {
		427	$self->_error (&Errno::ETIMEDOUT);
		428	}
		429
		430	# callback could have changed timeout value, optimise
		431	return unless $self->{timeout};
		432
		433	# calculate new after
		434	$after = $self->{timeout};
		435	}
		436
		437	Scalar::Util::weaken $self;
		438	return unless $self; # ->error could have destroyed $self
		439
		440	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		441	delete $self->{_tw};
		442	$self->_timeout;
		443	});
		444	} else {
		445	delete $self->{_tw};
		446	}
		447	}
		448
213	#############################################################################	449	#############################################################################
214		450
215	=back	451	=back
216		452
217	=head2 WRITE QUEUE	453	=head2 WRITE QUEUE
…		…
220	for reading.	456	for reading.
221		457
222	The write queue is very simple: you can add data to its end, and	458	The write queue is very simple: you can add data to its end, and
223	AnyEvent::Handle will automatically try to get rid of it for you.	459	AnyEvent::Handle will automatically try to get rid of it for you.
224		460
225	When data could be writtena nd the write buffer is shorter then the low	461	When data could be written and the write buffer is shorter then the low
226	water mark, the C<on_drain> callback will be invoked.	462	water mark, the C<on_drain> callback will be invoked.
227		463
228	=over 4	464	=over 4
229		465
230	=item $handle->on_drain ($cb)	466	=item $handle->on_drain ($cb)
…		…
249	want (only limited by the available memory), as C<AnyEvent::Handle>	485	want (only limited by the available memory), as C<AnyEvent::Handle>
250	buffers it independently of the kernel.	486	buffers it independently of the kernel.
251		487
252	=cut	488	=cut
253		489
254	sub push_write {	490	sub _drain_wbuf {
255	my ($self, $data) = @_;	491	my ($self) = @_;
256		492
257	$self->{wbuf} .= $data;	493	if (!$self->{_ww} && length $self->{wbuf}) {
258		494
259	unless ($self->{ww}) {
260	Scalar::Util::weaken $self;	495	Scalar::Util::weaken $self;
		496
261	my $cb = sub {	497	my $cb = sub {
262	my $len = syswrite $self->{fh}, $self->{wbuf};	498	my $len = syswrite $self->{fh}, $self->{wbuf};
263		499
264	if ($len > 0) {	500	if ($len >= 0) {
265	substr $self->{wbuf}, 0, $len, "";	501	substr $self->{wbuf}, 0, $len, "";
266		502
		503	$self->{_activity} = AnyEvent->now;
267		504
268	$self->{on_drain}($self)	505	$self->{on_drain}($self)
269	if $self->{low_water_mark} >= length $self->{wbuf}	506	if $self->{low_water_mark} >= length $self->{wbuf}
270	&& $self->{on_drain};	507	&& $self->{on_drain};
271		508
272	delete $self->{ww} unless length $self->{wbuf};	509	delete $self->{_ww} unless length $self->{wbuf};
273	} elsif ($! != EAGAIN && $! != EINTR) {	510	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
274	$self->error;	511	$self->_error ($!, 1);
275	}	512	}
276	};	513	};
277		514
		515	# try to write data immediately
		516	$cb->() unless $self->{autocork};
		517
		518	# if still data left in wbuf, we need to poll
278	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	519	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
279		520	if length $self->{wbuf};
280	$cb->($self);
281	};	521	};
282	}	522	}
		523
		524	our %WH;
		525
		526	sub register_write_type($$) {
		527	$WH{$_[0]} = $_[1];
		528	}
		529
		530	sub push_write {
		531	my $self = shift;
		532
		533	if (@_ > 1) {
		534	my $type = shift;
		535
		536	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		537	->($self, @_);
		538	}
		539
		540	if ($self->{filter_w}) {
		541	$self->{filter_w}($self, \$_[0]);
		542	} else {
		543	$self->{wbuf} .= $_[0];
		544	$self->_drain_wbuf;
		545	}
		546	}
		547
		548	=item $handle->push_write (type => @args)
		549
		550	Instead of formatting your data yourself, you can also let this module do
		551	the job by specifying a type and type-specific arguments.
		552
		553	Predefined types are (if you have ideas for additional types, feel free to
		554	drop by and tell us):
		555
		556	=over 4
		557
		558	=item netstring => $string
		559
		560	Formats the given value as netstring
		561	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		562
		563	=cut
		564
		565	register_write_type netstring => sub {
		566	my ($self, $string) = @_;
		567
		568	sprintf "%d:%s,", (length $string), $string
		569	};
		570
		571	=item packstring => $format, $data
		572
		573	An octet string prefixed with an encoded length. The encoding C<$format>
		574	uses the same format as a Perl C<pack> format, but must specify a single
		575	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		576	optional C<!>, C<< < >> or C<< > >> modifier).
		577
		578	=cut
		579
		580	register_write_type packstring => sub {
		581	my ($self, $format, $string) = @_;
		582
		583	pack "$format/a*", $string
		584	};
		585
		586	=item json => $array_or_hashref
		587
		588	Encodes the given hash or array reference into a JSON object. Unless you
		589	provide your own JSON object, this means it will be encoded to JSON text
		590	in UTF-8.
		591
		592	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		593	one end of a handle and read them at the other end without using any
		594	additional framing.
		595
		596	The generated JSON text is guaranteed not to contain any newlines: While
		597	this module doesn't need delimiters after or between JSON texts to be
		598	able to read them, many other languages depend on that.
		599
		600	A simple RPC protocol that interoperates easily with others is to send
		601	JSON arrays (or objects, although arrays are usually the better choice as
		602	they mimic how function argument passing works) and a newline after each
		603	JSON text:
		604
		605	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		606	$handle->push_write ("\012");
		607
		608	An AnyEvent::Handle receiver would simply use the C<json> read type and
		609	rely on the fact that the newline will be skipped as leading whitespace:
		610
		611	$handle->push_read (json => sub { my $array = $_[1]; ... });
		612
		613	Other languages could read single lines terminated by a newline and pass
		614	this line into their JSON decoder of choice.
		615
		616	=cut
		617
		618	register_write_type json => sub {
		619	my ($self, $ref) = @_;
		620
		621	require JSON;
		622
		623	$self->{json} ? $self->{json}->encode ($ref)
		624	: JSON::encode_json ($ref)
		625	};
		626
		627	=item storable => $reference
		628
		629	Freezes the given reference using L<Storable> and writes it to the
		630	handle. Uses the C<nfreeze> format.
		631
		632	=cut
		633
		634	register_write_type storable => sub {
		635	my ($self, $ref) = @_;
		636
		637	require Storable;
		638
		639	pack "w/a*", Storable::nfreeze ($ref)
		640	};
		641
		642	=back
		643
		644	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		645
		646	This function (not method) lets you add your own types to C<push_write>.
		647	Whenever the given C<type> is used, C<push_write> will invoke the code
		648	reference with the handle object and the remaining arguments.
		649
		650	The code reference is supposed to return a single octet string that will
		651	be appended to the write buffer.
		652
		653	Note that this is a function, and all types registered this way will be
		654	global, so try to use unique names.
		655
		656	=cut
283		657
284	#############################################################################	658	#############################################################################
285		659
286	=back	660	=back
287		661
…		…
294	ways, the "simple" way, using only C<on_read> and the "complex" way, using	668	ways, the "simple" way, using only C<on_read> and the "complex" way, using
295	a queue.	669	a queue.
296		670
297	In the simple case, you just install an C<on_read> callback and whenever	671	In the simple case, you just install an C<on_read> callback and whenever
298	new data arrives, it will be called. You can then remove some data (if	672	new data arrives, it will be called. You can then remove some data (if
299	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	673	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
300	or not.	674	leave the data there if you want to accumulate more (e.g. when only a
		675	partial message has been received so far).
301		676
302	In the more complex case, you want to queue multiple callbacks. In this	677	In the more complex case, you want to queue multiple callbacks. In this
303	case, AnyEvent::Handle will call the first queued callback each time new	678	case, AnyEvent::Handle will call the first queued callback each time new
304	data arrives and removes it when it has done its job (see C<push_read>,	679	data arrives (also the first time it is queued) and removes it when it has
305	below).	680	done its job (see C<push_read>, below).
306		681
307	This way you can, for example, push three line-reads, followed by reading	682	This way you can, for example, push three line-reads, followed by reading
308	a chunk of data, and AnyEvent::Handle will execute them in order.	683	a chunk of data, and AnyEvent::Handle will execute them in order.
309		684
310	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	685	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
311	the specified number of bytes which give an XML datagram.	686	the specified number of bytes which give an XML datagram.
312		687
313	# in the default state, expect some header bytes	688	# in the default state, expect some header bytes
314	$handle->on_read (sub {	689	$handle->on_read (sub {
315	# some data is here, now queue the length-header-read (4 octets)	690	# some data is here, now queue the length-header-read (4 octets)
316	shift->unshift_read_chunk (4, sub {	691	shift->unshift_read (chunk => 4, sub {
317	# header arrived, decode	692	# header arrived, decode
318	my $len = unpack "N", $_[1];	693	my $len = unpack "N", $_[1];
319		694
320	# now read the payload	695	# now read the payload
321	shift->unshift_read_chunk ($len, sub {	696	shift->unshift_read (chunk => $len, sub {
322	my $xml = $_[1];	697	my $xml = $_[1];
323	# handle xml	698	# handle xml
324	});	699	});
325	});	700	});
326	});	701	});
327		702
328	Example 2: Implement a client for a protocol that replies either with	703	Example 2: Implement a client for a protocol that replies either with "OK"
329	"OK" and another line or "ERROR" for one request, and 64 bytes for the	704	and another line or "ERROR" for the first request that is sent, and 64
330	second request. Due tot he availability of a full queue, we can just	705	bytes for the second request. Due to the availability of a queue, we can
331	pipeline sending both requests and manipulate the queue as necessary in	706	just pipeline sending both requests and manipulate the queue as necessary
332	the callbacks:	707	in the callbacks.
333		708
334	# request one	709	When the first callback is called and sees an "OK" response, it will
		710	C<unshift> another line-read. This line-read will be queued I<before> the
		711	64-byte chunk callback.
		712
		713	# request one, returns either "OK + extra line" or "ERROR"
335	$handle->push_write ("request 1\015\012");	714	$handle->push_write ("request 1\015\012");
336		715
337	# we expect "ERROR" or "OK" as response, so push a line read	716	# we expect "ERROR" or "OK" as response, so push a line read
338	$handle->push_read_line (sub {	717	$handle->push_read (line => sub {
339	# if we got an "OK", we have to _prepend_ another line,	718	# if we got an "OK", we have to _prepend_ another line,
340	# so it will be read before the second request reads its 64 bytes	719	# so it will be read before the second request reads its 64 bytes
341	# which are already in the queue when this callback is called	720	# which are already in the queue when this callback is called
342	# we don't do this in case we got an error	721	# we don't do this in case we got an error
343	if ($_[1] eq "OK") {	722	if ($_[1] eq "OK") {
344	$_[0]->unshift_read_line (sub {	723	$_[0]->unshift_read (line => sub {
345	my $response = $_[1];	724	my $response = $_[1];
346	...	725	...
347	});	726	});
348	}	727	}
349	});	728	});
350		729
351	# request two	730	# request two, simply returns 64 octets
352	$handle->push_write ("request 2\015\012");	731	$handle->push_write ("request 2\015\012");
353		732
354	# simply read 64 bytes, always	733	# simply read 64 bytes, always
355	$handle->push_read_chunk (64, sub {	734	$handle->push_read (chunk => 64, sub {
356	my $response = $_[1];	735	my $response = $_[1];
357	...	736	...
358	});	737	});
359		738
360	=over 4	739	=over 4
…		…
362	=cut	741	=cut
363		742
364	sub _drain_rbuf {	743	sub _drain_rbuf {
365	my ($self) = @_;	744	my ($self) = @_;
366		745
367	return if $self->{in_drain};
368	local $self->{in_drain} = 1;	746	local $self->{_in_drain} = 1;
369		747
		748	if (
		749	defined $self->{rbuf_max}
		750	&& $self->{rbuf_max} < length $self->{rbuf}
		751	) {
		752	$self->_error (&Errno::ENOSPC, 1), return;
		753	}
		754
		755	while () {
370	while (my $len = length $self->{rbuf}) {	756	my $len = length $self->{rbuf};
371	no strict 'refs';	757
372	if (my $cb = shift @{ $self->{queue} }) {	758	if (my $cb = shift @{ $self->{_queue} }) {
373	if (!$cb->($self)) {	759	unless ($cb->($self)) {
374	if ($self->{eof}) {	760	if ($self->{_eof}) {
375	# no progress can be made (not enough data and no data forthcoming)	761	# no progress can be made (not enough data and no data forthcoming)
376	$! = &Errno::EPIPE; return $self->error;	762	$self->_error (&Errno::EPIPE, 1), return;
377	}	763	}
378		764
379	unshift @{ $self->{queue} }, $cb;	765	unshift @{ $self->{_queue} }, $cb;
380	return;	766	last;
381	}	767	}
382	} elsif ($self->{on_read}) {	768	} elsif ($self->{on_read}) {
		769	last unless $len;
		770
383	$self->{on_read}($self);	771	$self->{on_read}($self);
384		772
385	if (	773	if (
386	$self->{eof} # if no further data will arrive
387	&& $len == length $self->{rbuf} # and no data has been consumed	774	$len == length $self->{rbuf} # if no data has been consumed
388	&& !@{ $self->{queue} } # and the queue is still empty	775	&& !@{ $self->{_queue} } # and the queue is still empty
389	&& $self->{on_read} # and we still want to read data	776	&& $self->{on_read} # but we still have on_read
390	) {	777	) {
		778	# no further data will arrive
391	# then no progress can be made	779	# so no progress can be made
392	$! = &Errno::EPIPE; return $self->error;	780	$self->_error (&Errno::EPIPE, 1), return
		781	if $self->{_eof};
		782
		783	last; # more data might arrive
393	}	784	}
394	} else {	785	} else {
395	# read side becomes idle	786	# read side becomes idle
396	delete $self->{rw};	787	delete $self->{_rw};
397	return;	788	last;
398	}	789	}
399	}	790	}
400		791
401	if ($self->{eof}) {	792	if ($self->{_eof}) {
402	$self->_shutdown;	793	if ($self->{on_eof}) {
403	$self->{on_eof}($self);	794	$self->{on_eof}($self)
		795	} else {
		796	$self->_error (0, 1);
		797	}
		798	}
		799
		800	# may need to restart read watcher
		801	unless ($self->{_rw}) {
		802	$self->start_read
		803	if $self->{on_read} || @{ $self->{_queue} };
404	}	804	}
405	}	805	}
406		806
407	=item $handle->on_read ($cb)	807	=item $handle->on_read ($cb)
408		808
…		…
414		814
415	sub on_read {	815	sub on_read {
416	my ($self, $cb) = @_;	816	my ($self, $cb) = @_;
417		817
418	$self->{on_read} = $cb;	818	$self->{on_read} = $cb;
		819	$self->_drain_rbuf if $cb && !$self->{_in_drain};
419	}	820	}
420		821
421	=item $handle->rbuf	822	=item $handle->rbuf
422		823
423	Returns the read buffer (as a modifiable lvalue).	824	Returns the read buffer (as a modifiable lvalue).
…		…
442	Append the given callback to the end of the queue (C<push_read>) or	843	Append the given callback to the end of the queue (C<push_read>) or
443	prepend it (C<unshift_read>).	844	prepend it (C<unshift_read>).
444		845
445	The callback is called each time some additional read data arrives.	846	The callback is called each time some additional read data arrives.
446		847
447	It must check wether enough data is in the read buffer already.	848	It must check whether enough data is in the read buffer already.
448		849
449	If not enough data is available, it must return the empty list or a false	850	If not enough data is available, it must return the empty list or a false
450	value, in which case it will be called repeatedly until enough data is	851	value, in which case it will be called repeatedly until enough data is
451	available (or an error condition is detected).	852	available (or an error condition is detected).
452		853
…		…
454	interested in (which can be none at all) and return a true value. After returning	855	interested in (which can be none at all) and return a true value. After returning
455	true, it will be removed from the queue.	856	true, it will be removed from the queue.
456		857
457	=cut	858	=cut
458		859
		860	our %RH;
		861
		862	sub register_read_type($$) {
		863	$RH{$_[0]} = $_[1];
		864	}
		865
459	sub push_read {	866	sub push_read {
460	my ($self, $cb) = @_;	867	my $self = shift;
		868	my $cb = pop;
461		869
		870	if (@_) {
		871	my $type = shift;
		872
		873	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		874	->($self, $cb, @_);
		875	}
		876
462	push @{ $self->{queue} }, $cb;	877	push @{ $self->{_queue} }, $cb;
463	$self->_drain_rbuf;	878	$self->_drain_rbuf unless $self->{_in_drain};
464	}	879	}
465		880
466	sub unshift_read {	881	sub unshift_read {
467	my ($self, $cb) = @_;	882	my $self = shift;
		883	my $cb = pop;
468		884
		885	if (@_) {
		886	my $type = shift;
		887
		888	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		889	->($self, $cb, @_);
		890	}
		891
		892
469	push @{ $self->{queue} }, $cb;	893	unshift @{ $self->{_queue} }, $cb;
470	$self->_drain_rbuf;	894	$self->_drain_rbuf unless $self->{_in_drain};
471	}	895	}
472		896
473	=item $handle->push_read_chunk ($len, $cb->($self, $data))	897	=item $handle->push_read (type => @args, $cb)
474		898
475	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	899	=item $handle->unshift_read (type => @args, $cb)
476		900
477	Append the given callback to the end of the queue (C<push_read_chunk>) or	901	Instead of providing a callback that parses the data itself you can chose
478	prepend it (C<unshift_read_chunk>).	902	between a number of predefined parsing formats, for chunks of data, lines
		903	etc.
479		904
480	The callback will be called only once C<$len> bytes have been read, and	905	Predefined types are (if you have ideas for additional types, feel free to
481	these C<$len> bytes will be passed to the callback.	906	drop by and tell us):
482		907
483	=cut	908	=over 4
484		909
485	sub _read_chunk($$) {	910	=item chunk => $octets, $cb->($handle, $data)
		911
		912	Invoke the callback only once C<$octets> bytes have been read. Pass the
		913	data read to the callback. The callback will never be called with less
		914	data.
		915
		916	Example: read 2 bytes.
		917
		918	$handle->push_read (chunk => 2, sub {
		919	warn "yay ", unpack "H*", $_[1];
		920	});
		921
		922	=cut
		923
		924	register_read_type chunk => sub {
486	my ($self, $len, $cb) = @_;	925	my ($self, $cb, $len) = @_;
487		926
488	sub {	927	sub {
489	$len <= length $_[0]{rbuf} or return;	928	$len <= length $_[0]{rbuf} or return;
490	$cb->($self, $_[0], substr $_[0]{rbuf}, 0, $len, "");	929	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
491	1	930	1
492	}	931	}
493	}	932	};
494		933
495	sub push_read_chunk {	934	=item line => [$eol, ]$cb->($handle, $line, $eol)
496	$_[0]->push_read (&_read_chunk);
497	}
498
499
500	sub unshift_read_chunk {
501	$_[0]->unshift_read (&_read_chunk);
502	}
503
504	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
505
506	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
507
508	Append the given callback to the end of the queue (C<push_read_line>) or
509	prepend it (C<unshift_read_line>).
510		935
511	The callback will be called only once a full line (including the end of	936	The callback will be called only once a full line (including the end of
512	line marker, C<$eol>) has been read. This line (excluding the end of line	937	line marker, C<$eol>) has been read. This line (excluding the end of line
513	marker) will be passed to the callback as second argument (C<$line>), and	938	marker) will be passed to the callback as second argument (C<$line>), and
514	the end of line marker as the third argument (C<$eol>).	939	the end of line marker as the third argument (C<$eol>).
…		…
525	Partial lines at the end of the stream will never be returned, as they are	950	Partial lines at the end of the stream will never be returned, as they are
526	not marked by the end of line marker.	951	not marked by the end of line marker.
527		952
528	=cut	953	=cut
529		954
530	sub _read_line($$) {	955	register_read_type line => sub {
531	my $self = shift;	956	my ($self, $cb, $eol) = @_;
532	my $cb = pop;
533	my $eol = @_ ? shift : qr|(\015?\012)|;
534	my $pos;
535		957
		958	if (@_ < 3) {
		959	# this is more than twice as fast as the generic code below
		960	sub {
		961	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		962
		963	$cb->($_[0], $1, $2);
		964	1
		965	}
		966	} else {
536	$eol = qr|(\Q$eol\E)| unless ref $eol;	967	$eol = quotemeta $eol unless ref $eol;
537	$eol = qr|^(.*?)($eol)|;	968	$eol = qr|^(.*?)($eol)|s;
		969
		970	sub {
		971	$_[0]{rbuf} =~ s/$eol// or return;
		972
		973	$cb->($_[0], $1, $2);
		974	1
		975	}
		976	}
		977	};
		978
		979	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		980
		981	Makes a regex match against the regex object C<$accept> and returns
		982	everything up to and including the match.
		983
		984	Example: read a single line terminated by '\n'.
		985
		986	$handle->push_read (regex => qr<\n>, sub { ... });
		987
		988	If C<$reject> is given and not undef, then it determines when the data is
		989	to be rejected: it is matched against the data when the C<$accept> regex
		990	does not match and generates an C<EBADMSG> error when it matches. This is
		991	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		992	receive buffer overflow).
		993
		994	Example: expect a single decimal number followed by whitespace, reject
		995	anything else (not the use of an anchor).
		996
		997	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		998
		999	If C<$skip> is given and not C<undef>, then it will be matched against
		1000	the receive buffer when neither C<$accept> nor C<$reject> match,
		1001	and everything preceding and including the match will be accepted
		1002	unconditionally. This is useful to skip large amounts of data that you
		1003	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1004	have to start matching from the beginning. This is purely an optimisation
		1005	and is usually worth only when you expect more than a few kilobytes.
		1006
		1007	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1008	expect the header to be very large (it isn't in practise, but...), we use
		1009	a skip regex to skip initial portions. The skip regex is tricky in that
		1010	it only accepts something not ending in either \015 or \012, as these are
		1011	required for the accept regex.
		1012
		1013	$handle->push_read (regex =>
		1014	qr<\015\012\015\012>,
		1015	undef, # no reject
		1016	qr<^.*[^\015\012]>,
		1017	sub { ... });
		1018
		1019	=cut
		1020
		1021	register_read_type regex => sub {
		1022	my ($self, $cb, $accept, $reject, $skip) = @_;
		1023
		1024	my $data;
		1025	my $rbuf = \$self->{rbuf};
538		1026
539	sub {	1027	sub {
540	$_[0]{rbuf} =~ s/$eol// or return;	1028	# accept
541		1029	if ($$rbuf =~ $accept) {
		1030	$data .= substr $$rbuf, 0, $+[0], "";
542	$cb->($self, $1, $2);	1031	$cb->($self, $data);
		1032	return 1;
		1033	}
		1034
		1035	# reject
		1036	if ($reject && $$rbuf =~ $reject) {
		1037	$self->_error (&Errno::EBADMSG);
		1038	}
		1039
		1040	# skip
		1041	if ($skip && $$rbuf =~ $skip) {
		1042	$data .= substr $$rbuf, 0, $+[0], "";
		1043	}
		1044
		1045	()
		1046	}
		1047	};
		1048
		1049	=item netstring => $cb->($handle, $string)
		1050
		1051	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1052
		1053	Throws an error with C<$!> set to EBADMSG on format violations.
		1054
		1055	=cut
		1056
		1057	register_read_type netstring => sub {
		1058	my ($self, $cb) = @_;
		1059
		1060	sub {
		1061	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1062	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1063	$self->_error (&Errno::EBADMSG);
		1064	}
		1065	return;
		1066	}
		1067
		1068	my $len = $1;
		1069
		1070	$self->unshift_read (chunk => $len, sub {
		1071	my $string = $_[1];
		1072	$_[0]->unshift_read (chunk => 1, sub {
		1073	if ($_[1] eq ",") {
		1074	$cb->($_[0], $string);
		1075	} else {
		1076	$self->_error (&Errno::EBADMSG);
		1077	}
		1078	});
		1079	});
		1080
543	1	1081	1
544	}	1082	}
545	}	1083	};
546		1084
547	sub push_read_line {	1085	=item packstring => $format, $cb->($handle, $string)
548	$_[0]->push_read (&_read_line);
549	}
550		1086
551	sub unshift_read_line {	1087	An octet string prefixed with an encoded length. The encoding C<$format>
552	$_[0]->unshift_read (&_read_line);	1088	uses the same format as a Perl C<pack> format, but must specify a single
553	}	1089	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1090	optional C<!>, C<< < >> or C<< > >> modifier).
		1091
		1092	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1093
		1094	Example: read a block of data prefixed by its length in BER-encoded
		1095	format (very efficient).
		1096
		1097	$handle->push_read (packstring => "w", sub {
		1098	my ($handle, $data) = @_;
		1099	});
		1100
		1101	=cut
		1102
		1103	register_read_type packstring => sub {
		1104	my ($self, $cb, $format) = @_;
		1105
		1106	sub {
		1107	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1108	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1109	or return;
		1110
		1111	$format = length pack $format, $len;
		1112
		1113	# bypass unshift if we already have the remaining chunk
		1114	if ($format + $len <= length $_[0]{rbuf}) {
		1115	my $data = substr $_[0]{rbuf}, $format, $len;
		1116	substr $_[0]{rbuf}, 0, $format + $len, "";
		1117	$cb->($_[0], $data);
		1118	} else {
		1119	# remove prefix
		1120	substr $_[0]{rbuf}, 0, $format, "";
		1121
		1122	# read remaining chunk
		1123	$_[0]->unshift_read (chunk => $len, $cb);
		1124	}
		1125
		1126	1
		1127	}
		1128	};
		1129
		1130	=item json => $cb->($handle, $hash_or_arrayref)
		1131
		1132	Reads a JSON object or array, decodes it and passes it to the callback.
		1133
		1134	If a C<json> object was passed to the constructor, then that will be used
		1135	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1136
		1137	This read type uses the incremental parser available with JSON version
		1138	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1139	dependency on your own: this module will load the JSON module, but
		1140	AnyEvent does not depend on it itself.
		1141
		1142	Since JSON texts are fully self-delimiting, the C<json> read and write
		1143	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1144	the C<json> write type description, above, for an actual example.
		1145
		1146	=cut
		1147
		1148	register_read_type json => sub {
		1149	my ($self, $cb) = @_;
		1150
		1151	require JSON;
		1152
		1153	my $data;
		1154	my $rbuf = \$self->{rbuf};
		1155
		1156	my $json = $self->{json} ||= JSON->new->utf8;
		1157
		1158	sub {
		1159	my $ref = $json->incr_parse ($self->{rbuf});
		1160
		1161	if ($ref) {
		1162	$self->{rbuf} = $json->incr_text;
		1163	$json->incr_text = "";
		1164	$cb->($self, $ref);
		1165
		1166	1
		1167	} else {
		1168	$self->{rbuf} = "";
		1169	()
		1170	}
		1171	}
		1172	};
		1173
		1174	=item storable => $cb->($handle, $ref)
		1175
		1176	Deserialises a L<Storable> frozen representation as written by the
		1177	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1178	data).
		1179
		1180	Raises C<EBADMSG> error if the data could not be decoded.
		1181
		1182	=cut
		1183
		1184	register_read_type storable => sub {
		1185	my ($self, $cb) = @_;
		1186
		1187	require Storable;
		1188
		1189	sub {
		1190	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1191	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1192	or return;
		1193
		1194	my $format = length pack "w", $len;
		1195
		1196	# bypass unshift if we already have the remaining chunk
		1197	if ($format + $len <= length $_[0]{rbuf}) {
		1198	my $data = substr $_[0]{rbuf}, $format, $len;
		1199	substr $_[0]{rbuf}, 0, $format + $len, "";
		1200	$cb->($_[0], Storable::thaw ($data));
		1201	} else {
		1202	# remove prefix
		1203	substr $_[0]{rbuf}, 0, $format, "";
		1204
		1205	# read remaining chunk
		1206	$_[0]->unshift_read (chunk => $len, sub {
		1207	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1208	$cb->($_[0], $ref);
		1209	} else {
		1210	$self->_error (&Errno::EBADMSG);
		1211	}
		1212	});
		1213	}
		1214
		1215	1
		1216	}
		1217	};
		1218
		1219	=back
		1220
		1221	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1222
		1223	This function (not method) lets you add your own types to C<push_read>.
		1224
		1225	Whenever the given C<type> is used, C<push_read> will invoke the code
		1226	reference with the handle object, the callback and the remaining
		1227	arguments.
		1228
		1229	The code reference is supposed to return a callback (usually a closure)
		1230	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1231
		1232	It should invoke the passed callback when it is done reading (remember to
		1233	pass C<$handle> as first argument as all other callbacks do that).
		1234
		1235	Note that this is a function, and all types registered this way will be
		1236	global, so try to use unique names.
		1237
		1238	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1239	search for C<register_read_type>)).
554		1240
555	=item $handle->stop_read	1241	=item $handle->stop_read
556		1242
557	=item $handle->start_read	1243	=item $handle->start_read
558		1244
559	In rare cases you actually do not want to read anything form the	1245	In rare cases you actually do not want to read anything from the
560	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1246	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
561	any queued callbacks will be executed then. To start readign again, call	1247	any queued callbacks will be executed then. To start reading again, call
562	C<start_read>.	1248	C<start_read>.
		1249
		1250	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1251	you change the C<on_read> callback or push/unshift a read callback, and it
		1252	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1253	there are any read requests in the queue.
563		1254
564	=cut	1255	=cut
565		1256
566	sub stop_read {	1257	sub stop_read {
567	my ($self) = @_;	1258	my ($self) = @_;
568		1259
569	delete $self->{rw};	1260	delete $self->{_rw};
570	}	1261	}
571		1262
572	sub start_read {	1263	sub start_read {
573	my ($self) = @_;	1264	my ($self) = @_;
574		1265
575	unless ($self->{rw} || $self->{eof}) {	1266	unless ($self->{_rw} || $self->{_eof}) {
576	Scalar::Util::weaken $self;	1267	Scalar::Util::weaken $self;
577		1268
578	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1269	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1270	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
579	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1271	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
580		1272
581	if ($len > 0) {	1273	if ($len > 0) {
582	if (defined $self->{rbuf_max}) {	1274	$self->{_activity} = AnyEvent->now;
583	if ($self->{rbuf_max} < length $self->{rbuf}) {	1275
584	$! = &Errno::ENOSPC; return $self->error;	1276	$self->{filter_r}
585	}	1277	? $self->{filter_r}($self, $rbuf)
586	}	1278	: $self->{_in_drain} || $self->_drain_rbuf;
587		1279
588	} elsif (defined $len) {	1280	} elsif (defined $len) {
589	$self->{eof} = 1;
590	delete $self->{rw};	1281	delete $self->{_rw};
		1282	$self->{_eof} = 1;
		1283	$self->_drain_rbuf unless $self->{_in_drain};
591		1284
592	} elsif ($! != EAGAIN && $! != EINTR) {	1285	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
593	return $self->error;	1286	return $self->_error ($!, 1);
594	}	1287	}
595
596	$self->_drain_rbuf;
597	});	1288	});
598	}	1289	}
599	}	1290	}
600		1291
		1292	sub _dotls {
		1293	my ($self) = @_;
		1294
		1295	my $buf;
		1296
		1297	if (length $self->{_tls_wbuf}) {
		1298	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1299	substr $self->{_tls_wbuf}, 0, $len, "";
		1300	}
		1301	}
		1302
		1303	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1304	$self->{wbuf} .= $buf;
		1305	$self->_drain_wbuf;
		1306	}
		1307
		1308	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1309	if (length $buf) {
		1310	$self->{rbuf} .= $buf;
		1311	$self->_drain_rbuf unless $self->{_in_drain};
		1312	} else {
		1313	# let's treat SSL-eof as we treat normal EOF
		1314	$self->{_eof} = 1;
		1315	$self->_shutdown;
		1316	return;
		1317	}
		1318	}
		1319
		1320	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1321
		1322	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1323	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1324	return $self->_error ($!, 1);
		1325	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1326	return $self->_error (&Errno::EIO, 1);
		1327	}
		1328
		1329	# all others are fine for our purposes
		1330	}
		1331	}
		1332
		1333	=item $handle->starttls ($tls[, $tls_ctx])
		1334
		1335	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1336	object is created, you can also do that at a later time by calling
		1337	C<starttls>.
		1338
		1339	The first argument is the same as the C<tls> constructor argument (either
		1340	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1341
		1342	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1343	used when AnyEvent::Handle has to create its own TLS connection object.
		1344
		1345	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1346	call and can be used or changed to your liking. Note that the handshake
		1347	might have already started when this function returns.
		1348
		1349	=cut
		1350
		1351	sub starttls {
		1352	my ($self, $ssl, $ctx) = @_;
		1353
		1354	$self->stoptls;
		1355
		1356	if ($ssl eq "accept") {
		1357	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1358	Net::SSLeay::set_accept_state ($ssl);
		1359	} elsif ($ssl eq "connect") {
		1360	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1361	Net::SSLeay::set_connect_state ($ssl);
		1362	}
		1363
		1364	$self->{tls} = $ssl;
		1365
		1366	# basically, this is deep magic (because SSL_read should have the same issues)
		1367	# but the openssl maintainers basically said: "trust us, it just works".
		1368	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1369	# and mismaintained ssleay-module doesn't even offer them).
		1370	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1371	Net::SSLeay::CTX_set_mode ($self->{tls},
		1372	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1373	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1374
		1375	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1376	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1377
		1378	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1379
		1380	$self->{filter_w} = sub {
		1381	$_[0]{_tls_wbuf} .= ${$_[1]};
		1382	&_dotls;
		1383	};
		1384	$self->{filter_r} = sub {
		1385	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1386	&_dotls;
		1387	};
		1388	}
		1389
		1390	=item $handle->stoptls
		1391
		1392	Destroys the SSL connection, if any. Partial read or write data will be
		1393	lost.
		1394
		1395	=cut
		1396
		1397	sub stoptls {
		1398	my ($self) = @_;
		1399
		1400	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1401
		1402	delete $self->{_rbio};
		1403	delete $self->{_wbio};
		1404	delete $self->{_tls_wbuf};
		1405	delete $self->{filter_r};
		1406	delete $self->{filter_w};
		1407	}
		1408
		1409	sub DESTROY {
		1410	my $self = shift;
		1411
		1412	$self->stoptls;
		1413
		1414	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1415
		1416	if ($linger && length $self->{wbuf}) {
		1417	my $fh = delete $self->{fh};
		1418	my $wbuf = delete $self->{wbuf};
		1419
		1420	my @linger;
		1421
		1422	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1423	my $len = syswrite $fh, $wbuf, length $wbuf;
		1424
		1425	if ($len > 0) {
		1426	substr $wbuf, 0, $len, "";
		1427	} else {
		1428	@linger = (); # end
		1429	}
		1430	});
		1431	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1432	@linger = ();
		1433	});
		1434	}
		1435	}
		1436
		1437	=item AnyEvent::Handle::TLS_CTX
		1438
		1439	This function creates and returns the Net::SSLeay::CTX object used by
		1440	default for TLS mode.
		1441
		1442	The context is created like this:
		1443
		1444	Net::SSLeay::load_error_strings;
		1445	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1446	Net::SSLeay::randomize;
		1447
		1448	my $CTX = Net::SSLeay::CTX_new;
		1449
		1450	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1451
		1452	=cut
		1453
		1454	our $TLS_CTX;
		1455
		1456	sub TLS_CTX() {
		1457	$TLS_CTX || do {
		1458	require Net::SSLeay;
		1459
		1460	Net::SSLeay::load_error_strings ();
		1461	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1462	Net::SSLeay::randomize ();
		1463
		1464	$TLS_CTX = Net::SSLeay::CTX_new ();
		1465
		1466	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1467
		1468	$TLS_CTX
		1469	}
		1470	}
		1471
601	=back	1472	=back
602		1473
		1474	=head1 SUBCLASSING AnyEvent::Handle
		1475
		1476	In many cases, you might want to subclass AnyEvent::Handle.
		1477
		1478	To make this easier, a given version of AnyEvent::Handle uses these
		1479	conventions:
		1480
		1481	=over 4
		1482
		1483	=item * all constructor arguments become object members.
		1484
		1485	At least initially, when you pass a C<tls>-argument to the constructor it
		1486	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1487	mutated later on (for example C<tls> will hold the TLS connection object).
		1488
		1489	=item * other object member names are prefixed with an C<_>.
		1490
		1491	All object members not explicitly documented (internal use) are prefixed
		1492	with an underscore character, so the remaining non-C<_>-namespace is free
		1493	for use for subclasses.
		1494
		1495	=item * all members not documented here and not prefixed with an underscore
		1496	are free to use in subclasses.
		1497
		1498	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1499	member variables, but thats just life, at least it is documented.
		1500
		1501	=back
		1502
603	=head1 AUTHOR	1503	=head1 AUTHOR
604		1504
605	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1505	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
606		1506
607	=cut	1507	=cut

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