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Revision 1.16 by root, Fri May 23 05:16:57 2008 UTC vs.
Revision 1.83 by root, Thu Aug 21 19:11:37 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	This module is experimental.
18
19	=cut	17	=cut
20		18
21	our $VERSION = '0.04';	19	our $VERSION = 4.232;
22		20
23	=head1 SYNOPSIS	21	=head1 SYNOPSIS
24		22
25	use AnyEvent;	23	use AnyEvent;
26	use AnyEvent::Handle;	24	use AnyEvent::Handle;
27		25
28	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
29		27
30	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
31
32	#TODO
33
34	# or use the constructor to pass the callback:
35
36	my $ae_fh2 =
37	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
38	fh => \*STDIN,	30	fh => \*STDIN,
39	on_eof => sub {	31	on_eof => sub {
40	$cv->broadcast;	32	$cv->broadcast;
41	},	33	},
42	#TODO
43	);	34	);
44		35
45	$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;
46		47
47	=head1 DESCRIPTION	48	=head1 DESCRIPTION
48		49
49	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
50	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
…		…
69		70
70	=item fh => $filehandle [MANDATORY]	71	=item fh => $filehandle [MANDATORY]
71		72
72	The filehandle this L<AnyEvent::Handle> object will operate on.	73	The filehandle this L<AnyEvent::Handle> object will operate on.
73		74
74	NOTE: The filehandle will be set to non-blocking (using	75	NOTE: The filehandle will be set to non-blocking mode (using
75	AnyEvent::Util::fh_nonblocking).	76	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		77	that mode.
76		78
77	=item on_eof => $cb->($self)	79	=item on_eof => $cb->($handle)
78		80
79	Set the callback to be called on EOF.	81	Set the callback to be called when an end-of-file condition is detected,
		82	i.e. in the case of a socket, when the other side has closed the
		83	connection cleanly.
80		84
		85	For sockets, this just means that the other side has stopped sending data,
		86	you can still try to write data, and, in fact, one can return from the eof
		87	callback and continue writing data, as only the read part has been shut
		88	down.
		89
81	While not mandatory, it is highly recommended to set an eof callback,	90	While not mandatory, it is I<highly> recommended to set an eof callback,
82	otherwise you might end up with a closed socket while you are still	91	otherwise you might end up with a closed socket while you are still
83	waiting for data.	92	waiting for data.
84		93
		94	If an EOF condition has been detected but no C<on_eof> callback has been
		95	set, then a fatal error will be raised with C<$!> set to <0>.
		96
85	=item on_error => $cb->($self)	97	=item on_error => $cb->($handle, $fatal)
86		98
87	This is the fatal error callback, that is called when, well, a fatal error	99	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	100	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	101	connect or a read error.
90		102
91	The object will not be in a usable state when this callback has been	103	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	called.	104	fatal errors the handle object will be shut down and will not be usable
		105	(but you are free to look at the current C< ->rbuf >). Examples of fatal
		106	errors are an EOF condition with active (but unsatisifable) read watchers
		107	(C<EPIPE>) or I/O errors.
		108
		109	Non-fatal errors can be retried by simply returning, but it is recommended
		110	to simply ignore this parameter and instead abondon the handle object
		111	when this callback is invoked. Examples of non-fatal errors are timeouts
		112	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
93		113
94	On callback entrance, the value of C<$!> contains the operating system	114	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	115	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		116
97	While not mandatory, it is I<highly> recommended to set this callback, as	117	While not mandatory, it is I<highly> recommended to set this callback, as
98	you will not be notified of errors otherwise. The default simply calls	118	you will not be notified of errors otherwise. The default simply calls
99	die.	119	C<croak>.
100		120
101	=item on_read => $cb->($self)	121	=item on_read => $cb->($handle)
102		122
103	This sets the default read callback, which is called when data arrives	123	This sets the default read callback, which is called when data arrives
104	and no read request is in the queue.	124	and no read request is in the queue (unlike read queue callbacks, this
		125	callback will only be called when at least one octet of data is in the
		126	read buffer).
105		127
106	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	128	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107	method or acces sthe C<$self->{rbuf}> member directly.	129	method or access the C<$handle->{rbuf}> member directly.
108		130
109	When an EOF condition is detected then AnyEvent::Handle will first try to	131	When an EOF condition is detected then AnyEvent::Handle will first try to
110	feed all the remaining data to the queued callbacks and C<on_read> before	132	feed all the remaining data to the queued callbacks and C<on_read> before
111	calling the C<on_eof> callback. If no progress can be made, then a fatal	133	calling the C<on_eof> callback. If no progress can be made, then a fatal
112	error will be raised (with C<$!> set to C<EPIPE>).	134	error will be raised (with C<$!> set to C<EPIPE>).
113		135
114	=item on_drain => $cb->()	136	=item on_drain => $cb->($handle)
115		137
116	This sets the callback that is called when the write buffer becomes empty	138	This sets the callback that is called when the write buffer becomes empty
117	(or when the callback is set and the buffer is empty already).	139	(or when the callback is set and the buffer is empty already).
118		140
119	To append to the write buffer, use the C<< ->push_write >> method.	141	To append to the write buffer, use the C<< ->push_write >> method.
		142
		143	This callback is useful when you don't want to put all of your write data
		144	into the queue at once, for example, when you want to write the contents
		145	of some file to the socket you might not want to read the whole file into
		146	memory and push it into the queue, but instead only read more data from
		147	the file when the write queue becomes empty.
		148
		149	=item timeout => $fractional_seconds
		150
		151	If non-zero, then this enables an "inactivity" timeout: whenever this many
		152	seconds pass without a successful read or write on the underlying file
		153	handle, the C<on_timeout> callback will be invoked (and if that one is
		154	missing, an C<ETIMEDOUT> error will be raised).
		155
		156	Note that timeout processing is also active when you currently do not have
		157	any outstanding read or write requests: If you plan to keep the connection
		158	idle then you should disable the timout temporarily or ignore the timeout
		159	in the C<on_timeout> callback.
		160
		161	Zero (the default) disables this timeout.
		162
		163	=item on_timeout => $cb->($handle)
		164
		165	Called whenever the inactivity timeout passes. If you return from this
		166	callback, then the timeout will be reset as if some activity had happened,
		167	so this condition is not fatal in any way.
120		168
121	=item rbuf_max => <bytes>	169	=item rbuf_max => <bytes>
122		170
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	171	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	172	when the read buffer ever (strictly) exceeds this size. This is useful to
…		…
128	be configured to accept only so-and-so much data that it cannot act on	176	be configured to accept only so-and-so much data that it cannot act on
129	(for example, when expecting a line, an attacker could send an unlimited	177	(for example, when expecting a line, an attacker could send an unlimited
130	amount of data without a callback ever being called as long as the line	178	amount of data without a callback ever being called as long as the line
131	isn't finished).	179	isn't finished).
132		180
		181	=item autocork => <boolean>
		182
		183	When disabled (the default), then C<push_write> will try to immediately
		184	write the data to the handle if possible. This avoids having to register
		185	a write watcher and wait for the next event loop iteration, but can be
		186	inefficient if you write multiple small chunks (this disadvantage is
		187	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		188
		189	When enabled, then writes will always be queued till the next event loop
		190	iteration. This is efficient when you do many small writes per iteration,
		191	but less efficient when you do a single write only.
		192
		193	=item no_delay => <boolean>
		194
		195	When doing small writes on sockets, your operating system kernel might
		196	wait a bit for more data before actually sending it out. This is called
		197	the Nagle algorithm, and usually it is beneficial.
		198
		199	In some situations you want as low a delay as possible, which cna be
		200	accomplishd by setting this option to true.
		201
		202	The default is your opertaing system's default behaviour, this option
		203	explicitly enables or disables it, if possible.
		204
133	=item read_size => <bytes>	205	=item read_size => <bytes>
134		206
135	The default read block size (the amount of bytes this module will try to read	207	The default read block size (the amount of bytes this module will try to read
136	on each [loop iteration). Default: C<4096>.	208	during each (loop iteration). Default: C<8192>.
137		209
138	=item low_water_mark => <bytes>	210	=item low_water_mark => <bytes>
139		211
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	212	Sets the amount of bytes (default: C<0>) that make up an "empty" write
141	buffer: If the write reaches this size or gets even samller it is	213	buffer: If the write reaches this size or gets even samller it is
142	considered empty.	214	considered empty.
143		215
		216	=item linger => <seconds>
		217
		218	If non-zero (default: C<3600>), then the destructor of the
		219	AnyEvent::Handle object will check wether there is still outstanding write
		220	data and will install a watcher that will write out this data. No errors
		221	will be reported (this mostly matches how the operating system treats
		222	outstanding data at socket close time).
		223
		224	This will not work for partial TLS data that could not yet been
		225	encoded. This data will be lost.
		226
		227	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		228
		229	When this parameter is given, it enables TLS (SSL) mode, that means it
		230	will start making tls handshake and will transparently encrypt/decrypt
		231	data.
		232
		233	TLS mode requires Net::SSLeay to be installed (it will be loaded
		234	automatically when you try to create a TLS handle).
		235
		236	For the TLS server side, use C<accept>, and for the TLS client side of a
		237	connection, use C<connect> mode.
		238
		239	You can also provide your own TLS connection object, but you have
		240	to make sure that you call either C<Net::SSLeay::set_connect_state>
		241	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		242	AnyEvent::Handle.
		243
		244	See the C<starttls> method if you need to start TLS negotiation later.
		245
		246	=item tls_ctx => $ssl_ctx
		247
		248	Use the given Net::SSLeay::CTX object to create the new TLS connection
		249	(unless a connection object was specified directly). If this parameter is
		250	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		251
		252	=item json => JSON or JSON::XS object
		253
		254	This is the json coder object used by the C<json> read and write types.
		255
		256	If you don't supply it, then AnyEvent::Handle will create and use a
		257	suitable one, which will write and expect UTF-8 encoded JSON texts.
		258
		259	Note that you are responsible to depend on the JSON module if you want to
		260	use this functionality, as AnyEvent does not have a dependency itself.
		261
		262	=item filter_r => $cb
		263
		264	=item filter_w => $cb
		265
		266	These exist, but are undocumented at this time.
		267
144	=back	268	=back
145		269
146	=cut	270	=cut
147		271
148	sub new {	272	sub new {
…		…
152		276
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	277	$self->{fh} or Carp::croak "mandatory argument fh is missing";
154		278
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	279	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		280
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	281	if ($self->{tls}) {
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	282	require Net::SSLeay;
		283	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		284	}
		285
		286	$self->{_activity} = AnyEvent->now;
		287	$self->_timeout;
		288
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	289	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	290	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
161		291
162	$self->start_read;	292	$self->start_read
		293	if $self->{on_read};
163		294
164	$self	295	$self
165	}	296	}
166		297
167	sub _shutdown {	298	sub _shutdown {
168	my ($self) = @_;	299	my ($self) = @_;
169		300
		301	delete $self->{_tw};
170	delete $self->{rw};	302	delete $self->{_rw};
171	delete $self->{ww};	303	delete $self->{_ww};
172	delete $self->{fh};	304	delete $self->{fh};
173	}
174		305
		306	$self->stoptls;
		307
		308	delete $self->{on_read};
		309	delete $self->{_queue};
		310	}
		311
175	sub error {	312	sub _error {
176	my ($self) = @_;	313	my ($self, $errno, $fatal) = @_;
177		314
178	{
179	local $!;
180	$self->_shutdown;	315	$self->_shutdown
181	}	316	if $fatal;
		317
		318	$! = $errno;
182		319
183	if ($self->{on_error}) {	320	if ($self->{on_error}) {
184	$self->{on_error}($self);	321	$self->{on_error}($self, $fatal);
185	} else {	322	} else {
186	die "AnyEvent::Handle uncaught fatal error: $!";	323	Carp::croak "AnyEvent::Handle uncaught error: $!";
187	}	324	}
188	}	325	}
189		326
190	=item $fh = $handle->fh	327	=item $fh = $handle->fh
191		328
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	329	This method returns the file handle of the L<AnyEvent::Handle> object.
193		330
194	=cut	331	=cut
195		332
196	sub fh { $_[0]->{fh} }	333	sub fh { $_[0]{fh} }
197		334
198	=item $handle->on_error ($cb)	335	=item $handle->on_error ($cb)
199		336
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	337	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		338
…		…
213		350
214	sub on_eof {	351	sub on_eof {
215	$_[0]{on_eof} = $_[1];	352	$_[0]{on_eof} = $_[1];
216	}	353	}
217		354
		355	=item $handle->on_timeout ($cb)
		356
		357	Replace the current C<on_timeout> callback, or disables the callback
		358	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		359	argument.
		360
		361	=cut
		362
		363	sub on_timeout {
		364	$_[0]{on_timeout} = $_[1];
		365	}
		366
		367	=item $handle->autocork ($boolean)
		368
		369	Enables or disables the current autocork behaviour (see C<autocork>
		370	constructor argument).
		371
		372	=cut
		373
		374	=item $handle->no_delay ($boolean)
		375
		376	Enables or disables the C<no_delay> setting (see constructor argument of
		377	the same name for details).
		378
		379	=cut
		380
		381	sub no_delay {
		382	$_[0]{no_delay} = $_[1];
		383
		384	eval {
		385	local $SIG{__DIE__};
		386	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		387	};
		388	}
		389
		390	#############################################################################
		391
		392	=item $handle->timeout ($seconds)
		393
		394	Configures (or disables) the inactivity timeout.
		395
		396	=cut
		397
		398	sub timeout {
		399	my ($self, $timeout) = @_;
		400
		401	$self->{timeout} = $timeout;
		402	$self->_timeout;
		403	}
		404
		405	# reset the timeout watcher, as neccessary
		406	# also check for time-outs
		407	sub _timeout {
		408	my ($self) = @_;
		409
		410	if ($self->{timeout}) {
		411	my $NOW = AnyEvent->now;
		412
		413	# when would the timeout trigger?
		414	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		415
		416	# now or in the past already?
		417	if ($after <= 0) {
		418	$self->{_activity} = $NOW;
		419
		420	if ($self->{on_timeout}) {
		421	$self->{on_timeout}($self);
		422	} else {
		423	$self->_error (&Errno::ETIMEDOUT);
		424	}
		425
		426	# callback could have changed timeout value, optimise
		427	return unless $self->{timeout};
		428
		429	# calculate new after
		430	$after = $self->{timeout};
		431	}
		432
		433	Scalar::Util::weaken $self;
		434	return unless $self; # ->error could have destroyed $self
		435
		436	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		437	delete $self->{_tw};
		438	$self->_timeout;
		439	});
		440	} else {
		441	delete $self->{_tw};
		442	}
		443	}
		444
218	#############################################################################	445	#############################################################################
219		446
220	=back	447	=back
221		448
222	=head2 WRITE QUEUE	449	=head2 WRITE QUEUE
…		…
225	for reading.	452	for reading.
226		453
227	The write queue is very simple: you can add data to its end, and	454	The write queue is very simple: you can add data to its end, and
228	AnyEvent::Handle will automatically try to get rid of it for you.	455	AnyEvent::Handle will automatically try to get rid of it for you.
229		456
230	When data could be writtena nd the write buffer is shorter then the low	457	When data could be written and the write buffer is shorter then the low
231	water mark, the C<on_drain> callback will be invoked.	458	water mark, the C<on_drain> callback will be invoked.
232		459
233	=over 4	460	=over 4
234		461
235	=item $handle->on_drain ($cb)	462	=item $handle->on_drain ($cb)
…		…
254	want (only limited by the available memory), as C<AnyEvent::Handle>	481	want (only limited by the available memory), as C<AnyEvent::Handle>
255	buffers it independently of the kernel.	482	buffers it independently of the kernel.
256		483
257	=cut	484	=cut
258		485
259	sub push_write {	486	sub _drain_wbuf {
260	my ($self, $data) = @_;	487	my ($self) = @_;
261		488
262	$self->{wbuf} .= $data;	489	if (!$self->{_ww} && length $self->{wbuf}) {
263		490
264	unless ($self->{ww}) {
265	Scalar::Util::weaken $self;	491	Scalar::Util::weaken $self;
		492
266	my $cb = sub {	493	my $cb = sub {
267	my $len = syswrite $self->{fh}, $self->{wbuf};	494	my $len = syswrite $self->{fh}, $self->{wbuf};
268		495
269	if ($len > 0) {	496	if ($len >= 0) {
270	substr $self->{wbuf}, 0, $len, "";	497	substr $self->{wbuf}, 0, $len, "";
271		498
		499	$self->{_activity} = AnyEvent->now;
272		500
273	$self->{on_drain}($self)	501	$self->{on_drain}($self)
274	if $self->{low_water_mark} >= length $self->{wbuf}	502	if $self->{low_water_mark} >= length $self->{wbuf}
275	&& $self->{on_drain};	503	&& $self->{on_drain};
276		504
277	delete $self->{ww} unless length $self->{wbuf};	505	delete $self->{_ww} unless length $self->{wbuf};
278	} elsif ($! != EAGAIN && $! != EINTR) {	506	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
279	$self->error;	507	$self->_error ($!, 1);
280	}	508	}
281	};	509	};
282		510
		511	# try to write data immediately
		512	$cb->() unless $self->{autocork};
		513
		514	# if still data left in wbuf, we need to poll
283	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	515	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
284		516	if length $self->{wbuf};
285	$cb->($self);
286	};	517	};
287	}	518	}
		519
		520	our %WH;
		521
		522	sub register_write_type($$) {
		523	$WH{$_[0]} = $_[1];
		524	}
		525
		526	sub push_write {
		527	my $self = shift;
		528
		529	if (@_ > 1) {
		530	my $type = shift;
		531
		532	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		533	->($self, @_);
		534	}
		535
		536	if ($self->{filter_w}) {
		537	$self->{filter_w}($self, \$_[0]);
		538	} else {
		539	$self->{wbuf} .= $_[0];
		540	$self->_drain_wbuf;
		541	}
		542	}
		543
		544	=item $handle->push_write (type => @args)
		545
		546	Instead of formatting your data yourself, you can also let this module do
		547	the job by specifying a type and type-specific arguments.
		548
		549	Predefined types are (if you have ideas for additional types, feel free to
		550	drop by and tell us):
		551
		552	=over 4
		553
		554	=item netstring => $string
		555
		556	Formats the given value as netstring
		557	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		558
		559	=cut
		560
		561	register_write_type netstring => sub {
		562	my ($self, $string) = @_;
		563
		564	sprintf "%d:%s,", (length $string), $string
		565	};
		566
		567	=item packstring => $format, $data
		568
		569	An octet string prefixed with an encoded length. The encoding C<$format>
		570	uses the same format as a Perl C<pack> format, but must specify a single
		571	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		572	optional C<!>, C<< < >> or C<< > >> modifier).
		573
		574	=cut
		575
		576	register_write_type packstring => sub {
		577	my ($self, $format, $string) = @_;
		578
		579	pack "$format/a*", $string
		580	};
		581
		582	=item json => $array_or_hashref
		583
		584	Encodes the given hash or array reference into a JSON object. Unless you
		585	provide your own JSON object, this means it will be encoded to JSON text
		586	in UTF-8.
		587
		588	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		589	one end of a handle and read them at the other end without using any
		590	additional framing.
		591
		592	The generated JSON text is guaranteed not to contain any newlines: While
		593	this module doesn't need delimiters after or between JSON texts to be
		594	able to read them, many other languages depend on that.
		595
		596	A simple RPC protocol that interoperates easily with others is to send
		597	JSON arrays (or objects, although arrays are usually the better choice as
		598	they mimic how function argument passing works) and a newline after each
		599	JSON text:
		600
		601	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		602	$handle->push_write ("\012");
		603
		604	An AnyEvent::Handle receiver would simply use the C<json> read type and
		605	rely on the fact that the newline will be skipped as leading whitespace:
		606
		607	$handle->push_read (json => sub { my $array = $_[1]; ... });
		608
		609	Other languages could read single lines terminated by a newline and pass
		610	this line into their JSON decoder of choice.
		611
		612	=cut
		613
		614	register_write_type json => sub {
		615	my ($self, $ref) = @_;
		616
		617	require JSON;
		618
		619	$self->{json} ? $self->{json}->encode ($ref)
		620	: JSON::encode_json ($ref)
		621	};
		622
		623	=item storable => $reference
		624
		625	Freezes the given reference using L<Storable> and writes it to the
		626	handle. Uses the C<nfreeze> format.
		627
		628	=cut
		629
		630	register_write_type storable => sub {
		631	my ($self, $ref) = @_;
		632
		633	require Storable;
		634
		635	pack "w/a*", Storable::nfreeze ($ref)
		636	};
		637
		638	=back
		639
		640	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		641
		642	This function (not method) lets you add your own types to C<push_write>.
		643	Whenever the given C<type> is used, C<push_write> will invoke the code
		644	reference with the handle object and the remaining arguments.
		645
		646	The code reference is supposed to return a single octet string that will
		647	be appended to the write buffer.
		648
		649	Note that this is a function, and all types registered this way will be
		650	global, so try to use unique names.
		651
		652	=cut
288		653
289	#############################################################################	654	#############################################################################
290		655
291	=back	656	=back
292		657
…		…
299	ways, the "simple" way, using only C<on_read> and the "complex" way, using	664	ways, the "simple" way, using only C<on_read> and the "complex" way, using
300	a queue.	665	a queue.
301		666
302	In the simple case, you just install an C<on_read> callback and whenever	667	In the simple case, you just install an C<on_read> callback and whenever
303	new data arrives, it will be called. You can then remove some data (if	668	new data arrives, it will be called. You can then remove some data (if
304	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	669	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
305	or not.	670	leave the data there if you want to accumulate more (e.g. when only a
		671	partial message has been received so far).
306		672
307	In the more complex case, you want to queue multiple callbacks. In this	673	In the more complex case, you want to queue multiple callbacks. In this
308	case, AnyEvent::Handle will call the first queued callback each time new	674	case, AnyEvent::Handle will call the first queued callback each time new
309	data arrives and removes it when it has done its job (see C<push_read>,	675	data arrives (also the first time it is queued) and removes it when it has
310	below).	676	done its job (see C<push_read>, below).
311		677
312	This way you can, for example, push three line-reads, followed by reading	678	This way you can, for example, push three line-reads, followed by reading
313	a chunk of data, and AnyEvent::Handle will execute them in order.	679	a chunk of data, and AnyEvent::Handle will execute them in order.
314		680
315	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	681	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
316	the specified number of bytes which give an XML datagram.	682	the specified number of bytes which give an XML datagram.
317		683
318	# in the default state, expect some header bytes	684	# in the default state, expect some header bytes
319	$handle->on_read (sub {	685	$handle->on_read (sub {
320	# some data is here, now queue the length-header-read (4 octets)	686	# some data is here, now queue the length-header-read (4 octets)
321	shift->unshift_read_chunk (4, sub {	687	shift->unshift_read (chunk => 4, sub {
322	# header arrived, decode	688	# header arrived, decode
323	my $len = unpack "N", $_[1];	689	my $len = unpack "N", $_[1];
324		690
325	# now read the payload	691	# now read the payload
326	shift->unshift_read_chunk ($len, sub {	692	shift->unshift_read (chunk => $len, sub {
327	my $xml = $_[1];	693	my $xml = $_[1];
328	# handle xml	694	# handle xml
329	});	695	});
330	});	696	});
331	});	697	});
332		698
333	Example 2: Implement a client for a protocol that replies either with	699	Example 2: Implement a client for a protocol that replies either with "OK"
334	"OK" and another line or "ERROR" for one request, and 64 bytes for the	700	and another line or "ERROR" for the first request that is sent, and 64
335	second request. Due tot he availability of a full queue, we can just	701	bytes for the second request. Due to the availability of a queue, we can
336	pipeline sending both requests and manipulate the queue as necessary in	702	just pipeline sending both requests and manipulate the queue as necessary
337	the callbacks:	703	in the callbacks.
338		704
339	# request one	705	When the first callback is called and sees an "OK" response, it will
		706	C<unshift> another line-read. This line-read will be queued I<before> the
		707	64-byte chunk callback.
		708
		709	# request one, returns either "OK + extra line" or "ERROR"
340	$handle->push_write ("request 1\015\012");	710	$handle->push_write ("request 1\015\012");
341		711
342	# we expect "ERROR" or "OK" as response, so push a line read	712	# we expect "ERROR" or "OK" as response, so push a line read
343	$handle->push_read_line (sub {	713	$handle->push_read (line => sub {
344	# if we got an "OK", we have to _prepend_ another line,	714	# if we got an "OK", we have to _prepend_ another line,
345	# so it will be read before the second request reads its 64 bytes	715	# so it will be read before the second request reads its 64 bytes
346	# which are already in the queue when this callback is called	716	# which are already in the queue when this callback is called
347	# we don't do this in case we got an error	717	# we don't do this in case we got an error
348	if ($_[1] eq "OK") {	718	if ($_[1] eq "OK") {
349	$_[0]->unshift_read_line (sub {	719	$_[0]->unshift_read (line => sub {
350	my $response = $_[1];	720	my $response = $_[1];
351	...	721	...
352	});	722	});
353	}	723	}
354	});	724	});
355		725
356	# request two	726	# request two, simply returns 64 octets
357	$handle->push_write ("request 2\015\012");	727	$handle->push_write ("request 2\015\012");
358		728
359	# simply read 64 bytes, always	729	# simply read 64 bytes, always
360	$handle->push_read_chunk (64, sub {	730	$handle->push_read (chunk => 64, sub {
361	my $response = $_[1];	731	my $response = $_[1];
362	...	732	...
363	});	733	});
364		734
365	=over 4	735	=over 4
…		…
367	=cut	737	=cut
368		738
369	sub _drain_rbuf {	739	sub _drain_rbuf {
370	my ($self) = @_;	740	my ($self) = @_;
371		741
372	return if $self->{in_drain};
373	local $self->{in_drain} = 1;	742	local $self->{_in_drain} = 1;
374		743
		744	if (
		745	defined $self->{rbuf_max}
		746	&& $self->{rbuf_max} < length $self->{rbuf}
		747	) {
		748	$self->_error (&Errno::ENOSPC, 1), return;
		749	}
		750
		751	while () {
375	while (my $len = length $self->{rbuf}) {	752	my $len = length $self->{rbuf};
376	no strict 'refs';	753
377	if (my $cb = shift @{ $self->{queue} }) {	754	if (my $cb = shift @{ $self->{_queue} }) {
378	if (!$cb->($self)) {	755	unless ($cb->($self)) {
379	if ($self->{eof}) {	756	if ($self->{_eof}) {
380	# no progress can be made (not enough data and no data forthcoming)	757	# no progress can be made (not enough data and no data forthcoming)
381	$! = &Errno::EPIPE; return $self->error;	758	$self->_error (&Errno::EPIPE, 1), return;
382	}	759	}
383		760
384	unshift @{ $self->{queue} }, $cb;	761	unshift @{ $self->{_queue} }, $cb;
385	return;	762	last;
386	}	763	}
387	} elsif ($self->{on_read}) {	764	} elsif ($self->{on_read}) {
		765	last unless $len;
		766
388	$self->{on_read}($self);	767	$self->{on_read}($self);
389		768
390	if (	769	if (
391	$self->{eof} # if no further data will arrive
392	&& $len == length $self->{rbuf} # and no data has been consumed	770	$len == length $self->{rbuf} # if no data has been consumed
393	&& !@{ $self->{queue} } # and the queue is still empty	771	&& !@{ $self->{_queue} } # and the queue is still empty
394	&& $self->{on_read} # and we still want to read data	772	&& $self->{on_read} # but we still have on_read
395	) {	773	) {
		774	# no further data will arrive
396	# then no progress can be made	775	# so no progress can be made
397	$! = &Errno::EPIPE; return $self->error;	776	$self->_error (&Errno::EPIPE, 1), return
		777	if $self->{_eof};
		778
		779	last; # more data might arrive
398	}	780	}
399	} else {	781	} else {
400	# read side becomes idle	782	# read side becomes idle
401	delete $self->{rw};	783	delete $self->{_rw};
402	return;	784	last;
403	}	785	}
404	}	786	}
405		787
406	if ($self->{eof}) {	788	if ($self->{_eof}) {
407	$self->_shutdown;	789	if ($self->{on_eof}) {
408	$self->{on_eof}($self)	790	$self->{on_eof}($self)
409	if $self->{on_eof};	791	} else {
		792	$self->_error (0, 1);
		793	}
		794	}
		795
		796	# may need to restart read watcher
		797	unless ($self->{_rw}) {
		798	$self->start_read
		799	if $self->{on_read} || @{ $self->{_queue} };
410	}	800	}
411	}	801	}
412		802
413	=item $handle->on_read ($cb)	803	=item $handle->on_read ($cb)
414		804
…		…
420		810
421	sub on_read {	811	sub on_read {
422	my ($self, $cb) = @_;	812	my ($self, $cb) = @_;
423		813
424	$self->{on_read} = $cb;	814	$self->{on_read} = $cb;
		815	$self->_drain_rbuf if $cb && !$self->{_in_drain};
425	}	816	}
426		817
427	=item $handle->rbuf	818	=item $handle->rbuf
428		819
429	Returns the read buffer (as a modifiable lvalue).	820	Returns the read buffer (as a modifiable lvalue).
…		…
448	Append the given callback to the end of the queue (C<push_read>) or	839	Append the given callback to the end of the queue (C<push_read>) or
449	prepend it (C<unshift_read>).	840	prepend it (C<unshift_read>).
450		841
451	The callback is called each time some additional read data arrives.	842	The callback is called each time some additional read data arrives.
452		843
453	It must check wether enough data is in the read buffer already.	844	It must check whether enough data is in the read buffer already.
454		845
455	If not enough data is available, it must return the empty list or a false	846	If not enough data is available, it must return the empty list or a false
456	value, in which case it will be called repeatedly until enough data is	847	value, in which case it will be called repeatedly until enough data is
457	available (or an error condition is detected).	848	available (or an error condition is detected).
458		849
…		…
460	interested in (which can be none at all) and return a true value. After returning	851	interested in (which can be none at all) and return a true value. After returning
461	true, it will be removed from the queue.	852	true, it will be removed from the queue.
462		853
463	=cut	854	=cut
464		855
		856	our %RH;
		857
		858	sub register_read_type($$) {
		859	$RH{$_[0]} = $_[1];
		860	}
		861
465	sub push_read {	862	sub push_read {
466	my ($self, $cb) = @_;	863	my $self = shift;
		864	my $cb = pop;
467		865
		866	if (@_) {
		867	my $type = shift;
		868
		869	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		870	->($self, $cb, @_);
		871	}
		872
468	push @{ $self->{queue} }, $cb;	873	push @{ $self->{_queue} }, $cb;
469	$self->_drain_rbuf;	874	$self->_drain_rbuf unless $self->{_in_drain};
470	}	875	}
471		876
472	sub unshift_read {	877	sub unshift_read {
473	my ($self, $cb) = @_;	878	my $self = shift;
		879	my $cb = pop;
474		880
		881	if (@_) {
		882	my $type = shift;
		883
		884	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		885	->($self, $cb, @_);
		886	}
		887
		888
475	push @{ $self->{queue} }, $cb;	889	unshift @{ $self->{_queue} }, $cb;
476	$self->_drain_rbuf;	890	$self->_drain_rbuf unless $self->{_in_drain};
477	}	891	}
478		892
479	=item $handle->push_read_chunk ($len, $cb->($self, $data))	893	=item $handle->push_read (type => @args, $cb)
480		894
481	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	895	=item $handle->unshift_read (type => @args, $cb)
482		896
483	Append the given callback to the end of the queue (C<push_read_chunk>) or	897	Instead of providing a callback that parses the data itself you can chose
484	prepend it (C<unshift_read_chunk>).	898	between a number of predefined parsing formats, for chunks of data, lines
		899	etc.
485		900
486	The callback will be called only once C<$len> bytes have been read, and	901	Predefined types are (if you have ideas for additional types, feel free to
487	these C<$len> bytes will be passed to the callback.	902	drop by and tell us):
488		903
489	=cut	904	=over 4
490		905
491	sub _read_chunk($$) {	906	=item chunk => $octets, $cb->($handle, $data)
		907
		908	Invoke the callback only once C<$octets> bytes have been read. Pass the
		909	data read to the callback. The callback will never be called with less
		910	data.
		911
		912	Example: read 2 bytes.
		913
		914	$handle->push_read (chunk => 2, sub {
		915	warn "yay ", unpack "H*", $_[1];
		916	});
		917
		918	=cut
		919
		920	register_read_type chunk => sub {
492	my ($self, $len, $cb) = @_;	921	my ($self, $cb, $len) = @_;
493		922
494	sub {	923	sub {
495	$len <= length $_[0]{rbuf} or return;	924	$len <= length $_[0]{rbuf} or return;
496	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	925	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
497	1	926	1
498	}	927	}
499	}	928	};
500		929
501	sub push_read_chunk {	930	=item line => [$eol, ]$cb->($handle, $line, $eol)
502	$_[0]->push_read (&_read_chunk);
503	}
504
505
506	sub unshift_read_chunk {
507	$_[0]->unshift_read (&_read_chunk);
508	}
509
510	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
511
512	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
513
514	Append the given callback to the end of the queue (C<push_read_line>) or
515	prepend it (C<unshift_read_line>).
516		931
517	The callback will be called only once a full line (including the end of	932	The callback will be called only once a full line (including the end of
518	line marker, C<$eol>) has been read. This line (excluding the end of line	933	line marker, C<$eol>) has been read. This line (excluding the end of line
519	marker) will be passed to the callback as second argument (C<$line>), and	934	marker) will be passed to the callback as second argument (C<$line>), and
520	the end of line marker as the third argument (C<$eol>).	935	the end of line marker as the third argument (C<$eol>).
…		…
531	Partial lines at the end of the stream will never be returned, as they are	946	Partial lines at the end of the stream will never be returned, as they are
532	not marked by the end of line marker.	947	not marked by the end of line marker.
533		948
534	=cut	949	=cut
535		950
536	sub _read_line($$) {	951	register_read_type line => sub {
537	my $self = shift;	952	my ($self, $cb, $eol) = @_;
538	my $cb = pop;
539	my $eol = @_ ? shift : qr|(\015?\012)|;
540	my $pos;
541		953
		954	if (@_ < 3) {
		955	# this is more than twice as fast as the generic code below
		956	sub {
		957	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		958
		959	$cb->($_[0], $1, $2);
		960	1
		961	}
		962	} else {
542	$eol = quotemeta $eol unless ref $eol;	963	$eol = quotemeta $eol unless ref $eol;
543	$eol = qr|^(.*?)($eol)|s;	964	$eol = qr|^(.*?)($eol)|s;
		965
		966	sub {
		967	$_[0]{rbuf} =~ s/$eol// or return;
		968
		969	$cb->($_[0], $1, $2);
		970	1
		971	}
		972	}
		973	};
		974
		975	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		976
		977	Makes a regex match against the regex object C<$accept> and returns
		978	everything up to and including the match.
		979
		980	Example: read a single line terminated by '\n'.
		981
		982	$handle->push_read (regex => qr<\n>, sub { ... });
		983
		984	If C<$reject> is given and not undef, then it determines when the data is
		985	to be rejected: it is matched against the data when the C<$accept> regex
		986	does not match and generates an C<EBADMSG> error when it matches. This is
		987	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		988	receive buffer overflow).
		989
		990	Example: expect a single decimal number followed by whitespace, reject
		991	anything else (not the use of an anchor).
		992
		993	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		994
		995	If C<$skip> is given and not C<undef>, then it will be matched against
		996	the receive buffer when neither C<$accept> nor C<$reject> match,
		997	and everything preceding and including the match will be accepted
		998	unconditionally. This is useful to skip large amounts of data that you
		999	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1000	have to start matching from the beginning. This is purely an optimisation
		1001	and is usually worth only when you expect more than a few kilobytes.
		1002
		1003	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1004	expect the header to be very large (it isn't in practise, but...), we use
		1005	a skip regex to skip initial portions. The skip regex is tricky in that
		1006	it only accepts something not ending in either \015 or \012, as these are
		1007	required for the accept regex.
		1008
		1009	$handle->push_read (regex =>
		1010	qr<\015\012\015\012>,
		1011	undef, # no reject
		1012	qr<^.*[^\015\012]>,
		1013	sub { ... });
		1014
		1015	=cut
		1016
		1017	register_read_type regex => sub {
		1018	my ($self, $cb, $accept, $reject, $skip) = @_;
		1019
		1020	my $data;
		1021	my $rbuf = \$self->{rbuf};
544		1022
545	sub {	1023	sub {
546	$_[0]{rbuf} =~ s/$eol// or return;	1024	# accept
		1025	if ($$rbuf =~ $accept) {
		1026	$data .= substr $$rbuf, 0, $+[0], "";
		1027	$cb->($self, $data);
		1028	return 1;
		1029	}
		1030
		1031	# reject
		1032	if ($reject && $$rbuf =~ $reject) {
		1033	$self->_error (&Errno::EBADMSG);
		1034	}
547		1035
548	$cb->($_[0], $1, $2);	1036	# skip
		1037	if ($skip && $$rbuf =~ $skip) {
		1038	$data .= substr $$rbuf, 0, $+[0], "";
		1039	}
		1040
		1041	()
		1042	}
		1043	};
		1044
		1045	=item netstring => $cb->($handle, $string)
		1046
		1047	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1048
		1049	Throws an error with C<$!> set to EBADMSG on format violations.
		1050
		1051	=cut
		1052
		1053	register_read_type netstring => sub {
		1054	my ($self, $cb) = @_;
		1055
		1056	sub {
		1057	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1058	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1059	$self->_error (&Errno::EBADMSG);
		1060	}
		1061	return;
		1062	}
		1063
		1064	my $len = $1;
		1065
		1066	$self->unshift_read (chunk => $len, sub {
		1067	my $string = $_[1];
		1068	$_[0]->unshift_read (chunk => 1, sub {
		1069	if ($_[1] eq ",") {
		1070	$cb->($_[0], $string);
		1071	} else {
		1072	$self->_error (&Errno::EBADMSG);
		1073	}
		1074	});
		1075	});
		1076
549	1	1077	1
550	}	1078	}
551	}	1079	};
552		1080
553	sub push_read_line {	1081	=item packstring => $format, $cb->($handle, $string)
554	$_[0]->push_read (&_read_line);
555	}
556		1082
557	sub unshift_read_line {	1083	An octet string prefixed with an encoded length. The encoding C<$format>
558	$_[0]->unshift_read (&_read_line);	1084	uses the same format as a Perl C<pack> format, but must specify a single
559	}	1085	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1086	optional C<!>, C<< < >> or C<< > >> modifier).
		1087
		1088	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1089
		1090	Example: read a block of data prefixed by its length in BER-encoded
		1091	format (very efficient).
		1092
		1093	$handle->push_read (packstring => "w", sub {
		1094	my ($handle, $data) = @_;
		1095	});
		1096
		1097	=cut
		1098
		1099	register_read_type packstring => sub {
		1100	my ($self, $cb, $format) = @_;
		1101
		1102	sub {
		1103	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1104	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1105	or return;
		1106
		1107	$format = length pack $format, $len;
		1108
		1109	# bypass unshift if we already have the remaining chunk
		1110	if ($format + $len <= length $_[0]{rbuf}) {
		1111	my $data = substr $_[0]{rbuf}, $format, $len;
		1112	substr $_[0]{rbuf}, 0, $format + $len, "";
		1113	$cb->($_[0], $data);
		1114	} else {
		1115	# remove prefix
		1116	substr $_[0]{rbuf}, 0, $format, "";
		1117
		1118	# read remaining chunk
		1119	$_[0]->unshift_read (chunk => $len, $cb);
		1120	}
		1121
		1122	1
		1123	}
		1124	};
		1125
		1126	=item json => $cb->($handle, $hash_or_arrayref)
		1127
		1128	Reads a JSON object or array, decodes it and passes it to the callback.
		1129
		1130	If a C<json> object was passed to the constructor, then that will be used
		1131	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1132
		1133	This read type uses the incremental parser available with JSON version
		1134	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1135	dependency on your own: this module will load the JSON module, but
		1136	AnyEvent does not depend on it itself.
		1137
		1138	Since JSON texts are fully self-delimiting, the C<json> read and write
		1139	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1140	the C<json> write type description, above, for an actual example.
		1141
		1142	=cut
		1143
		1144	register_read_type json => sub {
		1145	my ($self, $cb) = @_;
		1146
		1147	require JSON;
		1148
		1149	my $data;
		1150	my $rbuf = \$self->{rbuf};
		1151
		1152	my $json = $self->{json} ||= JSON->new->utf8;
		1153
		1154	sub {
		1155	my $ref = $json->incr_parse ($self->{rbuf});
		1156
		1157	if ($ref) {
		1158	$self->{rbuf} = $json->incr_text;
		1159	$json->incr_text = "";
		1160	$cb->($self, $ref);
		1161
		1162	1
		1163	} else {
		1164	$self->{rbuf} = "";
		1165	()
		1166	}
		1167	}
		1168	};
		1169
		1170	=item storable => $cb->($handle, $ref)
		1171
		1172	Deserialises a L<Storable> frozen representation as written by the
		1173	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1174	data).
		1175
		1176	Raises C<EBADMSG> error if the data could not be decoded.
		1177
		1178	=cut
		1179
		1180	register_read_type storable => sub {
		1181	my ($self, $cb) = @_;
		1182
		1183	require Storable;
		1184
		1185	sub {
		1186	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1187	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1188	or return;
		1189
		1190	my $format = length pack "w", $len;
		1191
		1192	# bypass unshift if we already have the remaining chunk
		1193	if ($format + $len <= length $_[0]{rbuf}) {
		1194	my $data = substr $_[0]{rbuf}, $format, $len;
		1195	substr $_[0]{rbuf}, 0, $format + $len, "";
		1196	$cb->($_[0], Storable::thaw ($data));
		1197	} else {
		1198	# remove prefix
		1199	substr $_[0]{rbuf}, 0, $format, "";
		1200
		1201	# read remaining chunk
		1202	$_[0]->unshift_read (chunk => $len, sub {
		1203	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1204	$cb->($_[0], $ref);
		1205	} else {
		1206	$self->_error (&Errno::EBADMSG);
		1207	}
		1208	});
		1209	}
		1210
		1211	1
		1212	}
		1213	};
		1214
		1215	=back
		1216
		1217	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1218
		1219	This function (not method) lets you add your own types to C<push_read>.
		1220
		1221	Whenever the given C<type> is used, C<push_read> will invoke the code
		1222	reference with the handle object, the callback and the remaining
		1223	arguments.
		1224
		1225	The code reference is supposed to return a callback (usually a closure)
		1226	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1227
		1228	It should invoke the passed callback when it is done reading (remember to
		1229	pass C<$handle> as first argument as all other callbacks do that).
		1230
		1231	Note that this is a function, and all types registered this way will be
		1232	global, so try to use unique names.
		1233
		1234	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1235	search for C<register_read_type>)).
560		1236
561	=item $handle->stop_read	1237	=item $handle->stop_read
562		1238
563	=item $handle->start_read	1239	=item $handle->start_read
564		1240
565	In rare cases you actually do not want to read anything form the	1241	In rare cases you actually do not want to read anything from the
566	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1242	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
567	any queued callbacks will be executed then. To start readign again, call	1243	any queued callbacks will be executed then. To start reading again, call
568	C<start_read>.	1244	C<start_read>.
		1245
		1246	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1247	you change the C<on_read> callback or push/unshift a read callback, and it
		1248	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1249	there are any read requests in the queue.
569		1250
570	=cut	1251	=cut
571		1252
572	sub stop_read {	1253	sub stop_read {
573	my ($self) = @_;	1254	my ($self) = @_;
574		1255
575	delete $self->{rw};	1256	delete $self->{_rw};
576	}	1257	}
577		1258
578	sub start_read {	1259	sub start_read {
579	my ($self) = @_;	1260	my ($self) = @_;
580		1261
581	unless ($self->{rw} || $self->{eof}) {	1262	unless ($self->{_rw} || $self->{_eof}) {
582	Scalar::Util::weaken $self;	1263	Scalar::Util::weaken $self;
583		1264
584	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1265	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1266	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
585	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1267	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
586		1268
587	if ($len > 0) {	1269	if ($len > 0) {
588	if (defined $self->{rbuf_max}) {	1270	$self->{_activity} = AnyEvent->now;
589	if ($self->{rbuf_max} < length $self->{rbuf}) {	1271
590	$! = &Errno::ENOSPC; return $self->error;	1272	$self->{filter_r}
591	}	1273	? $self->{filter_r}($self, $rbuf)
592	}	1274	: $self->{_in_drain} || $self->_drain_rbuf;
593		1275
594	} elsif (defined $len) {	1276	} elsif (defined $len) {
595	$self->{eof} = 1;
596	delete $self->{rw};	1277	delete $self->{_rw};
		1278	$self->{_eof} = 1;
		1279	$self->_drain_rbuf unless $self->{_in_drain};
597		1280
598	} elsif ($! != EAGAIN && $! != EINTR) {	1281	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
599	return $self->error;	1282	return $self->_error ($!, 1);
600	}	1283	}
601
602	$self->_drain_rbuf;
603	});	1284	});
604	}	1285	}
605	}	1286	}
606		1287
		1288	sub _dotls {
		1289	my ($self) = @_;
		1290
		1291	my $buf;
		1292
		1293	if (length $self->{_tls_wbuf}) {
		1294	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1295	substr $self->{_tls_wbuf}, 0, $len, "";
		1296	}
		1297	}
		1298
		1299	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1300	$self->{wbuf} .= $buf;
		1301	$self->_drain_wbuf;
		1302	}
		1303
		1304	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1305	if (length $buf) {
		1306	$self->{rbuf} .= $buf;
		1307	$self->_drain_rbuf unless $self->{_in_drain};
		1308	} else {
		1309	# let's treat SSL-eof as we treat normal EOF
		1310	$self->{_eof} = 1;
		1311	$self->_shutdown;
		1312	return;
		1313	}
		1314	}
		1315
		1316	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1317
		1318	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1319	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1320	return $self->_error ($!, 1);
		1321	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1322	return $self->_error (&Errno::EIO, 1);
		1323	}
		1324
		1325	# all others are fine for our purposes
		1326	}
		1327	}
		1328
		1329	=item $handle->starttls ($tls[, $tls_ctx])
		1330
		1331	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1332	object is created, you can also do that at a later time by calling
		1333	C<starttls>.
		1334
		1335	The first argument is the same as the C<tls> constructor argument (either
		1336	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1337
		1338	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1339	used when AnyEvent::Handle has to create its own TLS connection object.
		1340
		1341	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1342	call and can be used or changed to your liking. Note that the handshake
		1343	might have already started when this function returns.
		1344
		1345	=cut
		1346
		1347	sub starttls {
		1348	my ($self, $ssl, $ctx) = @_;
		1349
		1350	$self->stoptls;
		1351
		1352	if ($ssl eq "accept") {
		1353	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1354	Net::SSLeay::set_accept_state ($ssl);
		1355	} elsif ($ssl eq "connect") {
		1356	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1357	Net::SSLeay::set_connect_state ($ssl);
		1358	}
		1359
		1360	$self->{tls} = $ssl;
		1361
		1362	# basically, this is deep magic (because SSL_read should have the same issues)
		1363	# but the openssl maintainers basically said: "trust us, it just works".
		1364	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1365	# and mismaintained ssleay-module doesn't even offer them).
		1366	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1367	Net::SSLeay::CTX_set_mode ($self->{tls},
		1368	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1369	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1370
		1371	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1372	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1373
		1374	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1375
		1376	$self->{filter_w} = sub {
		1377	$_[0]{_tls_wbuf} .= ${$_[1]};
		1378	&_dotls;
		1379	};
		1380	$self->{filter_r} = sub {
		1381	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1382	&_dotls;
		1383	};
		1384	}
		1385
		1386	=item $handle->stoptls
		1387
		1388	Destroys the SSL connection, if any. Partial read or write data will be
		1389	lost.
		1390
		1391	=cut
		1392
		1393	sub stoptls {
		1394	my ($self) = @_;
		1395
		1396	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1397
		1398	delete $self->{_rbio};
		1399	delete $self->{_wbio};
		1400	delete $self->{_tls_wbuf};
		1401	delete $self->{filter_r};
		1402	delete $self->{filter_w};
		1403	}
		1404
		1405	sub DESTROY {
		1406	my $self = shift;
		1407
		1408	$self->stoptls;
		1409
		1410	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1411
		1412	if ($linger && length $self->{wbuf}) {
		1413	my $fh = delete $self->{fh};
		1414	my $wbuf = delete $self->{wbuf};
		1415
		1416	my @linger;
		1417
		1418	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1419	my $len = syswrite $fh, $wbuf, length $wbuf;
		1420
		1421	if ($len > 0) {
		1422	substr $wbuf, 0, $len, "";
		1423	} else {
		1424	@linger = (); # end
		1425	}
		1426	});
		1427	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1428	@linger = ();
		1429	});
		1430	}
		1431	}
		1432
		1433	=item AnyEvent::Handle::TLS_CTX
		1434
		1435	This function creates and returns the Net::SSLeay::CTX object used by
		1436	default for TLS mode.
		1437
		1438	The context is created like this:
		1439
		1440	Net::SSLeay::load_error_strings;
		1441	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1442	Net::SSLeay::randomize;
		1443
		1444	my $CTX = Net::SSLeay::CTX_new;
		1445
		1446	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1447
		1448	=cut
		1449
		1450	our $TLS_CTX;
		1451
		1452	sub TLS_CTX() {
		1453	$TLS_CTX || do {
		1454	require Net::SSLeay;
		1455
		1456	Net::SSLeay::load_error_strings ();
		1457	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1458	Net::SSLeay::randomize ();
		1459
		1460	$TLS_CTX = Net::SSLeay::CTX_new ();
		1461
		1462	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1463
		1464	$TLS_CTX
		1465	}
		1466	}
		1467
607	=back	1468	=back
608		1469
		1470	=head1 SUBCLASSING AnyEvent::Handle
		1471
		1472	In many cases, you might want to subclass AnyEvent::Handle.
		1473
		1474	To make this easier, a given version of AnyEvent::Handle uses these
		1475	conventions:
		1476
		1477	=over 4
		1478
		1479	=item * all constructor arguments become object members.
		1480
		1481	At least initially, when you pass a C<tls>-argument to the constructor it
		1482	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1483	mutated later on (for example C<tls> will hold the TLS connection object).
		1484
		1485	=item * other object member names are prefixed with an C<_>.
		1486
		1487	All object members not explicitly documented (internal use) are prefixed
		1488	with an underscore character, so the remaining non-C<_>-namespace is free
		1489	for use for subclasses.
		1490
		1491	=item * all members not documented here and not prefixed with an underscore
		1492	are free to use in subclasses.
		1493
		1494	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1495	member variables, but thats just life, at least it is documented.
		1496
		1497	=back
		1498
609	=head1 AUTHOR	1499	=head1 AUTHOR
610		1500
611	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1501	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
612		1502
613	=cut	1503	=cut

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