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Revision 1.16 by root, Fri May 23 05:16:57 2008 UTC vs.
Revision 1.79 by root, Sun Jul 27 08:37:56 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 = 4.22;
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
…		…
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 (using
75	AnyEvent::Util::fh_nonblocking).	76	AnyEvent::Util::fh_nonblocking).
76		77
77	=item on_eof => $cb->($self)	78	=item on_eof => $cb->($handle)
78		79
79	Set the callback to be called on EOF.	80	Set the callback to be called when an end-of-file condition is detected,
		81	i.e. in the case of a socket, when the other side has closed the
		82	connection cleanly.
80		83
81	While not mandatory, it is highly recommended to set an eof callback,	84	While not mandatory, it is highly recommended to set an eof callback,
82	otherwise you might end up with a closed socket while you are still	85	otherwise you might end up with a closed socket while you are still
83	waiting for data.	86	waiting for data.
84		87
85	=item on_error => $cb->($self)	88	=item on_error => $cb->($handle, $fatal)
86		89
87	This is the fatal error callback, that is called when, well, a fatal error	90	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	91	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	92	connect or a read error.
90		93
91	The object will not be in a usable state when this callback has been	94	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	called.	95	fatal errors the handle object will be shut down and will not be
		96	usable. Non-fatal errors can be retried by simply returning, but it is
		97	recommended to simply ignore this parameter and instead abondon the handle
		98	object when this callback is invoked.
93		99
94	On callback entrance, the value of C<$!> contains the operating system	100	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	101	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		102
97	While not mandatory, it is I<highly> recommended to set this callback, as	103	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	104	you will not be notified of errors otherwise. The default simply calls
99	die.	105	C<croak>.
100		106
101	=item on_read => $cb->($self)	107	=item on_read => $cb->($handle)
102		108
103	This sets the default read callback, which is called when data arrives	109	This sets the default read callback, which is called when data arrives
104	and no read request is in the queue.	110	and no read request is in the queue (unlike read queue callbacks, this
		111	callback will only be called when at least one octet of data is in the
		112	read buffer).
105		113
106	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	114	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107	method or acces sthe C<$self->{rbuf}> member directly.	115	method or access the C<$handle->{rbuf}> member directly.
108		116
109	When an EOF condition is detected then AnyEvent::Handle will first try to	117	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	118	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	119	calling the C<on_eof> callback. If no progress can be made, then a fatal
112	error will be raised (with C<$!> set to C<EPIPE>).	120	error will be raised (with C<$!> set to C<EPIPE>).
113		121
114	=item on_drain => $cb->()	122	=item on_drain => $cb->($handle)
115		123
116	This sets the callback that is called when the write buffer becomes empty	124	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).	125	(or when the callback is set and the buffer is empty already).
118		126
119	To append to the write buffer, use the C<< ->push_write >> method.	127	To append to the write buffer, use the C<< ->push_write >> method.
		128
		129	This callback is useful when you don't want to put all of your write data
		130	into the queue at once, for example, when you want to write the contents
		131	of some file to the socket you might not want to read the whole file into
		132	memory and push it into the queue, but instead only read more data from
		133	the file when the write queue becomes empty.
		134
		135	=item timeout => $fractional_seconds
		136
		137	If non-zero, then this enables an "inactivity" timeout: whenever this many
		138	seconds pass without a successful read or write on the underlying file
		139	handle, the C<on_timeout> callback will be invoked (and if that one is
		140	missing, an C<ETIMEDOUT> error will be raised).
		141
		142	Note that timeout processing is also active when you currently do not have
		143	any outstanding read or write requests: If you plan to keep the connection
		144	idle then you should disable the timout temporarily or ignore the timeout
		145	in the C<on_timeout> callback.
		146
		147	Zero (the default) disables this timeout.
		148
		149	=item on_timeout => $cb->($handle)
		150
		151	Called whenever the inactivity timeout passes. If you return from this
		152	callback, then the timeout will be reset as if some activity had happened,
		153	so this condition is not fatal in any way.
120		154
121	=item rbuf_max => <bytes>	155	=item rbuf_max => <bytes>
122		156
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	157	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	158	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	162	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	163	(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	164	amount of data without a callback ever being called as long as the line
131	isn't finished).	165	isn't finished).
132		166
		167	=item autocork => <boolean>
		168
		169	When disabled (the default), then C<push_write> will try to immediately
		170	write the data to the handle if possible. This avoids having to register
		171	a write watcher and wait for the next event loop iteration, but can be
		172	inefficient if you write multiple small chunks (this disadvantage is
		173	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		174
		175	When enabled, then writes will always be queued till the next event loop
		176	iteration. This is efficient when you do many small writes per iteration,
		177	but less efficient when you do a single write only.
		178
		179	=item no_delay => <boolean>
		180
		181	When doing small writes on sockets, your operating system kernel might
		182	wait a bit for more data before actually sending it out. This is called
		183	the Nagle algorithm, and usually it is beneficial.
		184
		185	In some situations you want as low a delay as possible, which cna be
		186	accomplishd by setting this option to true.
		187
		188	The default is your opertaing system's default behaviour, this option
		189	explicitly enables or disables it, if possible.
		190
133	=item read_size => <bytes>	191	=item read_size => <bytes>
134		192
135	The default read block size (the amount of bytes this module will try to read	193	The default read block size (the amount of bytes this module will try to read
136	on each [loop iteration). Default: C<4096>.	194	during each (loop iteration). Default: C<8192>.
137		195
138	=item low_water_mark => <bytes>	196	=item low_water_mark => <bytes>
139		197
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	198	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	199	buffer: If the write reaches this size or gets even samller it is
142	considered empty.	200	considered empty.
143		201
		202	=item linger => <seconds>
		203
		204	If non-zero (default: C<3600>), then the destructor of the
		205	AnyEvent::Handle object will check wether there is still outstanding write
		206	data and will install a watcher that will write out this data. No errors
		207	will be reported (this mostly matches how the operating system treats
		208	outstanding data at socket close time).
		209
		210	This will not work for partial TLS data that could not yet been
		211	encoded. This data will be lost.
		212
		213	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		214
		215	When this parameter is given, it enables TLS (SSL) mode, that means it
		216	will start making tls handshake and will transparently encrypt/decrypt
		217	data.
		218
		219	TLS mode requires Net::SSLeay to be installed (it will be loaded
		220	automatically when you try to create a TLS handle).
		221
		222	For the TLS server side, use C<accept>, and for the TLS client side of a
		223	connection, use C<connect> mode.
		224
		225	You can also provide your own TLS connection object, but you have
		226	to make sure that you call either C<Net::SSLeay::set_connect_state>
		227	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		228	AnyEvent::Handle.
		229
		230	See the C<starttls> method if you need to start TLS negotiation later.
		231
		232	=item tls_ctx => $ssl_ctx
		233
		234	Use the given Net::SSLeay::CTX object to create the new TLS connection
		235	(unless a connection object was specified directly). If this parameter is
		236	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		237
		238	=item json => JSON or JSON::XS object
		239
		240	This is the json coder object used by the C<json> read and write types.
		241
		242	If you don't supply it, then AnyEvent::Handle will create and use a
		243	suitable one, which will write and expect UTF-8 encoded JSON texts.
		244
		245	Note that you are responsible to depend on the JSON module if you want to
		246	use this functionality, as AnyEvent does not have a dependency itself.
		247
		248	=item filter_r => $cb
		249
		250	=item filter_w => $cb
		251
		252	These exist, but are undocumented at this time.
		253
144	=back	254	=back
145		255
146	=cut	256	=cut
147		257
148	sub new {	258	sub new {
…		…
152		262
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	263	$self->{fh} or Carp::croak "mandatory argument fh is missing";
154		264
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	265	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		266
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	267	if ($self->{tls}) {
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	268	require Net::SSLeay;
		269	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		270	}
		271
		272	$self->{_activity} = AnyEvent->now;
		273	$self->_timeout;
		274
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	275	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	276	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
161		277
162	$self->start_read;	278	$self->start_read
		279	if $self->{on_read};
163		280
164	$self	281	$self
165	}	282	}
166		283
167	sub _shutdown {	284	sub _shutdown {
168	my ($self) = @_;	285	my ($self) = @_;
169		286
		287	delete $self->{_tw};
170	delete $self->{rw};	288	delete $self->{_rw};
171	delete $self->{ww};	289	delete $self->{_ww};
172	delete $self->{fh};	290	delete $self->{fh};
173	}
174		291
		292	$self->stoptls;
		293	}
		294
175	sub error {	295	sub _error {
176	my ($self) = @_;	296	my ($self, $errno, $fatal) = @_;
177		297
178	{
179	local $!;
180	$self->_shutdown;	298	$self->_shutdown
181	}	299	if $fatal;
		300
		301	$! = $errno;
182		302
183	if ($self->{on_error}) {	303	if ($self->{on_error}) {
184	$self->{on_error}($self);	304	$self->{on_error}($self, $fatal);
185	} else {	305	} else {
186	die "AnyEvent::Handle uncaught fatal error: $!";	306	Carp::croak "AnyEvent::Handle uncaught error: $!";
187	}	307	}
188	}	308	}
189		309
190	=item $fh = $handle->fh	310	=item $fh = $handle->fh
191		311
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	312	This method returns the file handle of the L<AnyEvent::Handle> object.
193		313
194	=cut	314	=cut
195		315
196	sub fh { $_[0]->{fh} }	316	sub fh { $_[0]{fh} }
197		317
198	=item $handle->on_error ($cb)	318	=item $handle->on_error ($cb)
199		319
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	320	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		321
…		…
213		333
214	sub on_eof {	334	sub on_eof {
215	$_[0]{on_eof} = $_[1];	335	$_[0]{on_eof} = $_[1];
216	}	336	}
217		337
		338	=item $handle->on_timeout ($cb)
		339
		340	Replace the current C<on_timeout> callback, or disables the callback
		341	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		342	argument.
		343
		344	=cut
		345
		346	sub on_timeout {
		347	$_[0]{on_timeout} = $_[1];
		348	}
		349
		350	=item $handle->autocork ($boolean)
		351
		352	Enables or disables the current autocork behaviour (see C<autocork>
		353	constructor argument).
		354
		355	=cut
		356
		357	=item $handle->no_delay ($boolean)
		358
		359	Enables or disables the C<no_delay> setting (see constructor argument of
		360	the same name for details).
		361
		362	=cut
		363
		364	sub no_delay {
		365	$_[0]{no_delay} = $_[1];
		366
		367	eval {
		368	local $SIG{__DIE__};
		369	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		370	};
		371	}
		372
		373	#############################################################################
		374
		375	=item $handle->timeout ($seconds)
		376
		377	Configures (or disables) the inactivity timeout.
		378
		379	=cut
		380
		381	sub timeout {
		382	my ($self, $timeout) = @_;
		383
		384	$self->{timeout} = $timeout;
		385	$self->_timeout;
		386	}
		387
		388	# reset the timeout watcher, as neccessary
		389	# also check for time-outs
		390	sub _timeout {
		391	my ($self) = @_;
		392
		393	if ($self->{timeout}) {
		394	my $NOW = AnyEvent->now;
		395
		396	# when would the timeout trigger?
		397	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		398
		399	# now or in the past already?
		400	if ($after <= 0) {
		401	$self->{_activity} = $NOW;
		402
		403	if ($self->{on_timeout}) {
		404	$self->{on_timeout}($self);
		405	} else {
		406	$self->_error (&Errno::ETIMEDOUT);
		407	}
		408
		409	# callback could have changed timeout value, optimise
		410	return unless $self->{timeout};
		411
		412	# calculate new after
		413	$after = $self->{timeout};
		414	}
		415
		416	Scalar::Util::weaken $self;
		417	return unless $self; # ->error could have destroyed $self
		418
		419	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		420	delete $self->{_tw};
		421	$self->_timeout;
		422	});
		423	} else {
		424	delete $self->{_tw};
		425	}
		426	}
		427
218	#############################################################################	428	#############################################################################
219		429
220	=back	430	=back
221		431
222	=head2 WRITE QUEUE	432	=head2 WRITE QUEUE
…		…
225	for reading.	435	for reading.
226		436
227	The write queue is very simple: you can add data to its end, and	437	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.	438	AnyEvent::Handle will automatically try to get rid of it for you.
229		439
230	When data could be writtena nd the write buffer is shorter then the low	440	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.	441	water mark, the C<on_drain> callback will be invoked.
232		442
233	=over 4	443	=over 4
234		444
235	=item $handle->on_drain ($cb)	445	=item $handle->on_drain ($cb)
…		…
254	want (only limited by the available memory), as C<AnyEvent::Handle>	464	want (only limited by the available memory), as C<AnyEvent::Handle>
255	buffers it independently of the kernel.	465	buffers it independently of the kernel.
256		466
257	=cut	467	=cut
258		468
259	sub push_write {	469	sub _drain_wbuf {
260	my ($self, $data) = @_;	470	my ($self) = @_;
261		471
262	$self->{wbuf} .= $data;	472	if (!$self->{_ww} && length $self->{wbuf}) {
263		473
264	unless ($self->{ww}) {
265	Scalar::Util::weaken $self;	474	Scalar::Util::weaken $self;
		475
266	my $cb = sub {	476	my $cb = sub {
267	my $len = syswrite $self->{fh}, $self->{wbuf};	477	my $len = syswrite $self->{fh}, $self->{wbuf};
268		478
269	if ($len > 0) {	479	if ($len >= 0) {
270	substr $self->{wbuf}, 0, $len, "";	480	substr $self->{wbuf}, 0, $len, "";
271		481
		482	$self->{_activity} = AnyEvent->now;
272		483
273	$self->{on_drain}($self)	484	$self->{on_drain}($self)
274	if $self->{low_water_mark} >= length $self->{wbuf}	485	if $self->{low_water_mark} >= length $self->{wbuf}
275	&& $self->{on_drain};	486	&& $self->{on_drain};
276		487
277	delete $self->{ww} unless length $self->{wbuf};	488	delete $self->{_ww} unless length $self->{wbuf};
278	} elsif ($! != EAGAIN && $! != EINTR) {	489	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
279	$self->error;	490	$self->_error ($!, 1);
280	}	491	}
281	};	492	};
282		493
		494	# try to write data immediately
		495	$cb->() unless $self->{autocork};
		496
		497	# if still data left in wbuf, we need to poll
283	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	498	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
284		499	if length $self->{wbuf};
285	$cb->($self);
286	};	500	};
287	}	501	}
		502
		503	our %WH;
		504
		505	sub register_write_type($$) {
		506	$WH{$_[0]} = $_[1];
		507	}
		508
		509	sub push_write {
		510	my $self = shift;
		511
		512	if (@_ > 1) {
		513	my $type = shift;
		514
		515	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		516	->($self, @_);
		517	}
		518
		519	if ($self->{filter_w}) {
		520	$self->{filter_w}($self, \$_[0]);
		521	} else {
		522	$self->{wbuf} .= $_[0];
		523	$self->_drain_wbuf;
		524	}
		525	}
		526
		527	=item $handle->push_write (type => @args)
		528
		529	Instead of formatting your data yourself, you can also let this module do
		530	the job by specifying a type and type-specific arguments.
		531
		532	Predefined types are (if you have ideas for additional types, feel free to
		533	drop by and tell us):
		534
		535	=over 4
		536
		537	=item netstring => $string
		538
		539	Formats the given value as netstring
		540	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		541
		542	=cut
		543
		544	register_write_type netstring => sub {
		545	my ($self, $string) = @_;
		546
		547	sprintf "%d:%s,", (length $string), $string
		548	};
		549
		550	=item packstring => $format, $data
		551
		552	An octet string prefixed with an encoded length. The encoding C<$format>
		553	uses the same format as a Perl C<pack> format, but must specify a single
		554	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		555	optional C<!>, C<< < >> or C<< > >> modifier).
		556
		557	=cut
		558
		559	register_write_type packstring => sub {
		560	my ($self, $format, $string) = @_;
		561
		562	pack "$format/a*", $string
		563	};
		564
		565	=item json => $array_or_hashref
		566
		567	Encodes the given hash or array reference into a JSON object. Unless you
		568	provide your own JSON object, this means it will be encoded to JSON text
		569	in UTF-8.
		570
		571	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		572	one end of a handle and read them at the other end without using any
		573	additional framing.
		574
		575	The generated JSON text is guaranteed not to contain any newlines: While
		576	this module doesn't need delimiters after or between JSON texts to be
		577	able to read them, many other languages depend on that.
		578
		579	A simple RPC protocol that interoperates easily with others is to send
		580	JSON arrays (or objects, although arrays are usually the better choice as
		581	they mimic how function argument passing works) and a newline after each
		582	JSON text:
		583
		584	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		585	$handle->push_write ("\012");
		586
		587	An AnyEvent::Handle receiver would simply use the C<json> read type and
		588	rely on the fact that the newline will be skipped as leading whitespace:
		589
		590	$handle->push_read (json => sub { my $array = $_[1]; ... });
		591
		592	Other languages could read single lines terminated by a newline and pass
		593	this line into their JSON decoder of choice.
		594
		595	=cut
		596
		597	register_write_type json => sub {
		598	my ($self, $ref) = @_;
		599
		600	require JSON;
		601
		602	$self->{json} ? $self->{json}->encode ($ref)
		603	: JSON::encode_json ($ref)
		604	};
		605
		606	=item storable => $reference
		607
		608	Freezes the given reference using L<Storable> and writes it to the
		609	handle. Uses the C<nfreeze> format.
		610
		611	=cut
		612
		613	register_write_type storable => sub {
		614	my ($self, $ref) = @_;
		615
		616	require Storable;
		617
		618	pack "w/a*", Storable::nfreeze ($ref)
		619	};
		620
		621	=back
		622
		623	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		624
		625	This function (not method) lets you add your own types to C<push_write>.
		626	Whenever the given C<type> is used, C<push_write> will invoke the code
		627	reference with the handle object and the remaining arguments.
		628
		629	The code reference is supposed to return a single octet string that will
		630	be appended to the write buffer.
		631
		632	Note that this is a function, and all types registered this way will be
		633	global, so try to use unique names.
		634
		635	=cut
288		636
289	#############################################################################	637	#############################################################################
290		638
291	=back	639	=back
292		640
…		…
299	ways, the "simple" way, using only C<on_read> and the "complex" way, using	647	ways, the "simple" way, using only C<on_read> and the "complex" way, using
300	a queue.	648	a queue.
301		649
302	In the simple case, you just install an C<on_read> callback and whenever	650	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	651	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	652	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
305	or not.	653	leave the data there if you want to accumulate more (e.g. when only a
		654	partial message has been received so far).
306		655
307	In the more complex case, you want to queue multiple callbacks. In this	656	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	657	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>,	658	data arrives (also the first time it is queued) and removes it when it has
310	below).	659	done its job (see C<push_read>, below).
311		660
312	This way you can, for example, push three line-reads, followed by reading	661	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.	662	a chunk of data, and AnyEvent::Handle will execute them in order.
314		663
315	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	664	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
316	the specified number of bytes which give an XML datagram.	665	the specified number of bytes which give an XML datagram.
317		666
318	# in the default state, expect some header bytes	667	# in the default state, expect some header bytes
319	$handle->on_read (sub {	668	$handle->on_read (sub {
320	# some data is here, now queue the length-header-read (4 octets)	669	# some data is here, now queue the length-header-read (4 octets)
321	shift->unshift_read_chunk (4, sub {	670	shift->unshift_read (chunk => 4, sub {
322	# header arrived, decode	671	# header arrived, decode
323	my $len = unpack "N", $_[1];	672	my $len = unpack "N", $_[1];
324		673
325	# now read the payload	674	# now read the payload
326	shift->unshift_read_chunk ($len, sub {	675	shift->unshift_read (chunk => $len, sub {
327	my $xml = $_[1];	676	my $xml = $_[1];
328	# handle xml	677	# handle xml
329	});	678	});
330	});	679	});
331	});	680	});
332		681
333	Example 2: Implement a client for a protocol that replies either with	682	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	683	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	684	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	685	just pipeline sending both requests and manipulate the queue as necessary
337	the callbacks:	686	in the callbacks.
338		687
339	# request one	688	When the first callback is called and sees an "OK" response, it will
		689	C<unshift> another line-read. This line-read will be queued I<before> the
		690	64-byte chunk callback.
		691
		692	# request one, returns either "OK + extra line" or "ERROR"
340	$handle->push_write ("request 1\015\012");	693	$handle->push_write ("request 1\015\012");
341		694
342	# we expect "ERROR" or "OK" as response, so push a line read	695	# we expect "ERROR" or "OK" as response, so push a line read
343	$handle->push_read_line (sub {	696	$handle->push_read (line => sub {
344	# if we got an "OK", we have to _prepend_ another line,	697	# 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	698	# 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	699	# which are already in the queue when this callback is called
347	# we don't do this in case we got an error	700	# we don't do this in case we got an error
348	if ($_[1] eq "OK") {	701	if ($_[1] eq "OK") {
349	$_[0]->unshift_read_line (sub {	702	$_[0]->unshift_read (line => sub {
350	my $response = $_[1];	703	my $response = $_[1];
351	...	704	...
352	});	705	});
353	}	706	}
354	});	707	});
355		708
356	# request two	709	# request two, simply returns 64 octets
357	$handle->push_write ("request 2\015\012");	710	$handle->push_write ("request 2\015\012");
358		711
359	# simply read 64 bytes, always	712	# simply read 64 bytes, always
360	$handle->push_read_chunk (64, sub {	713	$handle->push_read (chunk => 64, sub {
361	my $response = $_[1];	714	my $response = $_[1];
362	...	715	...
363	});	716	});
364		717
365	=over 4	718	=over 4
…		…
367	=cut	720	=cut
368		721
369	sub _drain_rbuf {	722	sub _drain_rbuf {
370	my ($self) = @_;	723	my ($self) = @_;
371		724
372	return if $self->{in_drain};
373	local $self->{in_drain} = 1;	725	local $self->{_in_drain} = 1;
374		726
		727	if (
		728	defined $self->{rbuf_max}
		729	&& $self->{rbuf_max} < length $self->{rbuf}
		730	) {
		731	return $self->_error (&Errno::ENOSPC, 1);
		732	}
		733
		734	while () {
375	while (my $len = length $self->{rbuf}) {	735	my $len = length $self->{rbuf};
376	no strict 'refs';	736
377	if (my $cb = shift @{ $self->{queue} }) {	737	if (my $cb = shift @{ $self->{_queue} }) {
378	if (!$cb->($self)) {	738	unless ($cb->($self)) {
379	if ($self->{eof}) {	739	if ($self->{_eof}) {
380	# no progress can be made (not enough data and no data forthcoming)	740	# no progress can be made (not enough data and no data forthcoming)
381	$! = &Errno::EPIPE; return $self->error;	741	$self->_error (&Errno::EPIPE, 1), last;
382	}	742	}
383		743
384	unshift @{ $self->{queue} }, $cb;	744	unshift @{ $self->{_queue} }, $cb;
385	return;	745	last;
386	}	746	}
387	} elsif ($self->{on_read}) {	747	} elsif ($self->{on_read}) {
		748	last unless $len;
		749
388	$self->{on_read}($self);	750	$self->{on_read}($self);
389		751
390	if (	752	if (
391	$self->{eof} # if no further data will arrive
392	&& $len == length $self->{rbuf} # and no data has been consumed	753	$len == length $self->{rbuf} # if no data has been consumed
393	&& !@{ $self->{queue} } # and the queue is still empty	754	&& !@{ $self->{_queue} } # and the queue is still empty
394	&& $self->{on_read} # and we still want to read data	755	&& $self->{on_read} # but we still have on_read
395	) {	756	) {
		757	# no further data will arrive
396	# then no progress can be made	758	# so no progress can be made
397	$! = &Errno::EPIPE; return $self->error;	759	$self->_error (&Errno::EPIPE, 1), last
		760	if $self->{_eof};
		761
		762	last; # more data might arrive
398	}	763	}
399	} else {	764	} else {
400	# read side becomes idle	765	# read side becomes idle
401	delete $self->{rw};	766	delete $self->{_rw};
402	return;	767	last;
403	}	768	}
404	}	769	}
405		770
406	if ($self->{eof}) {
407	$self->_shutdown;
408	$self->{on_eof}($self)	771	$self->{on_eof}($self)
409	if $self->{on_eof};	772	if $self->{_eof} && $self->{on_eof};
		773
		774	# may need to restart read watcher
		775	unless ($self->{_rw}) {
		776	$self->start_read
		777	if $self->{on_read} || @{ $self->{_queue} };
410	}	778	}
411	}	779	}
412		780
413	=item $handle->on_read ($cb)	781	=item $handle->on_read ($cb)
414		782
…		…
420		788
421	sub on_read {	789	sub on_read {
422	my ($self, $cb) = @_;	790	my ($self, $cb) = @_;
423		791
424	$self->{on_read} = $cb;	792	$self->{on_read} = $cb;
		793	$self->_drain_rbuf if $cb && !$self->{_in_drain};
425	}	794	}
426		795
427	=item $handle->rbuf	796	=item $handle->rbuf
428		797
429	Returns the read buffer (as a modifiable lvalue).	798	Returns the read buffer (as a modifiable lvalue).
…		…
448	Append the given callback to the end of the queue (C<push_read>) or	817	Append the given callback to the end of the queue (C<push_read>) or
449	prepend it (C<unshift_read>).	818	prepend it (C<unshift_read>).
450		819
451	The callback is called each time some additional read data arrives.	820	The callback is called each time some additional read data arrives.
452		821
453	It must check wether enough data is in the read buffer already.	822	It must check whether enough data is in the read buffer already.
454		823
455	If not enough data is available, it must return the empty list or a false	824	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	825	value, in which case it will be called repeatedly until enough data is
457	available (or an error condition is detected).	826	available (or an error condition is detected).
458		827
…		…
460	interested in (which can be none at all) and return a true value. After returning	829	interested in (which can be none at all) and return a true value. After returning
461	true, it will be removed from the queue.	830	true, it will be removed from the queue.
462		831
463	=cut	832	=cut
464		833
		834	our %RH;
		835
		836	sub register_read_type($$) {
		837	$RH{$_[0]} = $_[1];
		838	}
		839
465	sub push_read {	840	sub push_read {
466	my ($self, $cb) = @_;	841	my $self = shift;
		842	my $cb = pop;
467		843
		844	if (@_) {
		845	my $type = shift;
		846
		847	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		848	->($self, $cb, @_);
		849	}
		850
468	push @{ $self->{queue} }, $cb;	851	push @{ $self->{_queue} }, $cb;
469	$self->_drain_rbuf;	852	$self->_drain_rbuf unless $self->{_in_drain};
470	}	853	}
471		854
472	sub unshift_read {	855	sub unshift_read {
473	my ($self, $cb) = @_;	856	my $self = shift;
		857	my $cb = pop;
474		858
		859	if (@_) {
		860	my $type = shift;
		861
		862	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		863	->($self, $cb, @_);
		864	}
		865
		866
475	push @{ $self->{queue} }, $cb;	867	unshift @{ $self->{_queue} }, $cb;
476	$self->_drain_rbuf;	868	$self->_drain_rbuf unless $self->{_in_drain};
477	}	869	}
478		870
479	=item $handle->push_read_chunk ($len, $cb->($self, $data))	871	=item $handle->push_read (type => @args, $cb)
480		872
481	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	873	=item $handle->unshift_read (type => @args, $cb)
482		874
483	Append the given callback to the end of the queue (C<push_read_chunk>) or	875	Instead of providing a callback that parses the data itself you can chose
484	prepend it (C<unshift_read_chunk>).	876	between a number of predefined parsing formats, for chunks of data, lines
		877	etc.
485		878
486	The callback will be called only once C<$len> bytes have been read, and	879	Predefined types are (if you have ideas for additional types, feel free to
487	these C<$len> bytes will be passed to the callback.	880	drop by and tell us):
488		881
489	=cut	882	=over 4
490		883
491	sub _read_chunk($$) {	884	=item chunk => $octets, $cb->($handle, $data)
		885
		886	Invoke the callback only once C<$octets> bytes have been read. Pass the
		887	data read to the callback. The callback will never be called with less
		888	data.
		889
		890	Example: read 2 bytes.
		891
		892	$handle->push_read (chunk => 2, sub {
		893	warn "yay ", unpack "H*", $_[1];
		894	});
		895
		896	=cut
		897
		898	register_read_type chunk => sub {
492	my ($self, $len, $cb) = @_;	899	my ($self, $cb, $len) = @_;
493		900
494	sub {	901	sub {
495	$len <= length $_[0]{rbuf} or return;	902	$len <= length $_[0]{rbuf} or return;
496	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	903	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
497	1	904	1
498	}	905	}
499	}	906	};
500		907
501	sub push_read_chunk {	908	=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		909
517	The callback will be called only once a full line (including the end of	910	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	911	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	912	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>).	913	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	924	Partial lines at the end of the stream will never be returned, as they are
532	not marked by the end of line marker.	925	not marked by the end of line marker.
533		926
534	=cut	927	=cut
535		928
536	sub _read_line($$) {	929	register_read_type line => sub {
537	my $self = shift;	930	my ($self, $cb, $eol) = @_;
538	my $cb = pop;
539	my $eol = @_ ? shift : qr|(\015?\012)|;
540	my $pos;
541		931
		932	if (@_ < 3) {
		933	# this is more than twice as fast as the generic code below
		934	sub {
		935	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		936
		937	$cb->($_[0], $1, $2);
		938	1
		939	}
		940	} else {
542	$eol = quotemeta $eol unless ref $eol;	941	$eol = quotemeta $eol unless ref $eol;
543	$eol = qr|^(.*?)($eol)|s;	942	$eol = qr|^(.*?)($eol)|s;
		943
		944	sub {
		945	$_[0]{rbuf} =~ s/$eol// or return;
		946
		947	$cb->($_[0], $1, $2);
		948	1
		949	}
		950	}
		951	};
		952
		953	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		954
		955	Makes a regex match against the regex object C<$accept> and returns
		956	everything up to and including the match.
		957
		958	Example: read a single line terminated by '\n'.
		959
		960	$handle->push_read (regex => qr<\n>, sub { ... });
		961
		962	If C<$reject> is given and not undef, then it determines when the data is
		963	to be rejected: it is matched against the data when the C<$accept> regex
		964	does not match and generates an C<EBADMSG> error when it matches. This is
		965	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		966	receive buffer overflow).
		967
		968	Example: expect a single decimal number followed by whitespace, reject
		969	anything else (not the use of an anchor).
		970
		971	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		972
		973	If C<$skip> is given and not C<undef>, then it will be matched against
		974	the receive buffer when neither C<$accept> nor C<$reject> match,
		975	and everything preceding and including the match will be accepted
		976	unconditionally. This is useful to skip large amounts of data that you
		977	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		978	have to start matching from the beginning. This is purely an optimisation
		979	and is usually worth only when you expect more than a few kilobytes.
		980
		981	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		982	expect the header to be very large (it isn't in practise, but...), we use
		983	a skip regex to skip initial portions. The skip regex is tricky in that
		984	it only accepts something not ending in either \015 or \012, as these are
		985	required for the accept regex.
		986
		987	$handle->push_read (regex =>
		988	qr<\015\012\015\012>,
		989	undef, # no reject
		990	qr<^.*[^\015\012]>,
		991	sub { ... });
		992
		993	=cut
		994
		995	register_read_type regex => sub {
		996	my ($self, $cb, $accept, $reject, $skip) = @_;
		997
		998	my $data;
		999	my $rbuf = \$self->{rbuf};
544		1000
545	sub {	1001	sub {
546	$_[0]{rbuf} =~ s/$eol// or return;	1002	# accept
		1003	if ($$rbuf =~ $accept) {
		1004	$data .= substr $$rbuf, 0, $+[0], "";
		1005	$cb->($self, $data);
		1006	return 1;
		1007	}
		1008
		1009	# reject
		1010	if ($reject && $$rbuf =~ $reject) {
		1011	$self->_error (&Errno::EBADMSG);
		1012	}
547		1013
548	$cb->($_[0], $1, $2);	1014	# skip
		1015	if ($skip && $$rbuf =~ $skip) {
		1016	$data .= substr $$rbuf, 0, $+[0], "";
		1017	}
		1018
		1019	()
		1020	}
		1021	};
		1022
		1023	=item netstring => $cb->($handle, $string)
		1024
		1025	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1026
		1027	Throws an error with C<$!> set to EBADMSG on format violations.
		1028
		1029	=cut
		1030
		1031	register_read_type netstring => sub {
		1032	my ($self, $cb) = @_;
		1033
		1034	sub {
		1035	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1036	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1037	$self->_error (&Errno::EBADMSG);
		1038	}
		1039	return;
		1040	}
		1041
		1042	my $len = $1;
		1043
		1044	$self->unshift_read (chunk => $len, sub {
		1045	my $string = $_[1];
		1046	$_[0]->unshift_read (chunk => 1, sub {
		1047	if ($_[1] eq ",") {
		1048	$cb->($_[0], $string);
		1049	} else {
		1050	$self->_error (&Errno::EBADMSG);
		1051	}
		1052	});
		1053	});
		1054
549	1	1055	1
550	}	1056	}
551	}	1057	};
552		1058
553	sub push_read_line {	1059	=item packstring => $format, $cb->($handle, $string)
554	$_[0]->push_read (&_read_line);
555	}
556		1060
557	sub unshift_read_line {	1061	An octet string prefixed with an encoded length. The encoding C<$format>
558	$_[0]->unshift_read (&_read_line);	1062	uses the same format as a Perl C<pack> format, but must specify a single
559	}	1063	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1064	optional C<!>, C<< < >> or C<< > >> modifier).
		1065
		1066	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1067
		1068	Example: read a block of data prefixed by its length in BER-encoded
		1069	format (very efficient).
		1070
		1071	$handle->push_read (packstring => "w", sub {
		1072	my ($handle, $data) = @_;
		1073	});
		1074
		1075	=cut
		1076
		1077	register_read_type packstring => sub {
		1078	my ($self, $cb, $format) = @_;
		1079
		1080	sub {
		1081	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1082	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1083	or return;
		1084
		1085	$format = length pack $format, $len;
		1086
		1087	# bypass unshift if we already have the remaining chunk
		1088	if ($format + $len <= length $_[0]{rbuf}) {
		1089	my $data = substr $_[0]{rbuf}, $format, $len;
		1090	substr $_[0]{rbuf}, 0, $format + $len, "";
		1091	$cb->($_[0], $data);
		1092	} else {
		1093	# remove prefix
		1094	substr $_[0]{rbuf}, 0, $format, "";
		1095
		1096	# read remaining chunk
		1097	$_[0]->unshift_read (chunk => $len, $cb);
		1098	}
		1099
		1100	1
		1101	}
		1102	};
		1103
		1104	=item json => $cb->($handle, $hash_or_arrayref)
		1105
		1106	Reads a JSON object or array, decodes it and passes it to the callback.
		1107
		1108	If a C<json> object was passed to the constructor, then that will be used
		1109	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1110
		1111	This read type uses the incremental parser available with JSON version
		1112	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1113	dependency on your own: this module will load the JSON module, but
		1114	AnyEvent does not depend on it itself.
		1115
		1116	Since JSON texts are fully self-delimiting, the C<json> read and write
		1117	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1118	the C<json> write type description, above, for an actual example.
		1119
		1120	=cut
		1121
		1122	register_read_type json => sub {
		1123	my ($self, $cb) = @_;
		1124
		1125	require JSON;
		1126
		1127	my $data;
		1128	my $rbuf = \$self->{rbuf};
		1129
		1130	my $json = $self->{json} ||= JSON->new->utf8;
		1131
		1132	sub {
		1133	my $ref = $json->incr_parse ($self->{rbuf});
		1134
		1135	if ($ref) {
		1136	$self->{rbuf} = $json->incr_text;
		1137	$json->incr_text = "";
		1138	$cb->($self, $ref);
		1139
		1140	1
		1141	} else {
		1142	$self->{rbuf} = "";
		1143	()
		1144	}
		1145	}
		1146	};
		1147
		1148	=item storable => $cb->($handle, $ref)
		1149
		1150	Deserialises a L<Storable> frozen representation as written by the
		1151	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1152	data).
		1153
		1154	Raises C<EBADMSG> error if the data could not be decoded.
		1155
		1156	=cut
		1157
		1158	register_read_type storable => sub {
		1159	my ($self, $cb) = @_;
		1160
		1161	require Storable;
		1162
		1163	sub {
		1164	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1165	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1166	or return;
		1167
		1168	my $format = length pack "w", $len;
		1169
		1170	# bypass unshift if we already have the remaining chunk
		1171	if ($format + $len <= length $_[0]{rbuf}) {
		1172	my $data = substr $_[0]{rbuf}, $format, $len;
		1173	substr $_[0]{rbuf}, 0, $format + $len, "";
		1174	$cb->($_[0], Storable::thaw ($data));
		1175	} else {
		1176	# remove prefix
		1177	substr $_[0]{rbuf}, 0, $format, "";
		1178
		1179	# read remaining chunk
		1180	$_[0]->unshift_read (chunk => $len, sub {
		1181	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1182	$cb->($_[0], $ref);
		1183	} else {
		1184	$self->_error (&Errno::EBADMSG);
		1185	}
		1186	});
		1187	}
		1188
		1189	1
		1190	}
		1191	};
		1192
		1193	=back
		1194
		1195	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1196
		1197	This function (not method) lets you add your own types to C<push_read>.
		1198
		1199	Whenever the given C<type> is used, C<push_read> will invoke the code
		1200	reference with the handle object, the callback and the remaining
		1201	arguments.
		1202
		1203	The code reference is supposed to return a callback (usually a closure)
		1204	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1205
		1206	It should invoke the passed callback when it is done reading (remember to
		1207	pass C<$handle> as first argument as all other callbacks do that).
		1208
		1209	Note that this is a function, and all types registered this way will be
		1210	global, so try to use unique names.
		1211
		1212	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1213	search for C<register_read_type>)).
560		1214
561	=item $handle->stop_read	1215	=item $handle->stop_read
562		1216
563	=item $handle->start_read	1217	=item $handle->start_read
564		1218
565	In rare cases you actually do not want to read anything form the	1219	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	1220	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	1221	any queued callbacks will be executed then. To start reading again, call
568	C<start_read>.	1222	C<start_read>.
		1223
		1224	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1225	you change the C<on_read> callback or push/unshift a read callback, and it
		1226	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1227	there are any read requests in the queue.
569		1228
570	=cut	1229	=cut
571		1230
572	sub stop_read {	1231	sub stop_read {
573	my ($self) = @_;	1232	my ($self) = @_;
574		1233
575	delete $self->{rw};	1234	delete $self->{_rw};
576	}	1235	}
577		1236
578	sub start_read {	1237	sub start_read {
579	my ($self) = @_;	1238	my ($self) = @_;
580		1239
581	unless ($self->{rw} || $self->{eof}) {	1240	unless ($self->{_rw} || $self->{_eof}) {
582	Scalar::Util::weaken $self;	1241	Scalar::Util::weaken $self;
583		1242
584	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1243	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1244	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
585	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1245	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
586		1246
587	if ($len > 0) {	1247	if ($len > 0) {
588	if (defined $self->{rbuf_max}) {	1248	$self->{_activity} = AnyEvent->now;
589	if ($self->{rbuf_max} < length $self->{rbuf}) {	1249
590	$! = &Errno::ENOSPC; return $self->error;	1250	$self->{filter_r}
591	}	1251	? $self->{filter_r}($self, $rbuf)
592	}	1252	: $self->{_in_drain} || $self->_drain_rbuf;
593		1253
594	} elsif (defined $len) {	1254	} elsif (defined $len) {
595	$self->{eof} = 1;
596	delete $self->{rw};	1255	delete $self->{_rw};
		1256	$self->{_eof} = 1;
		1257	$self->_drain_rbuf unless $self->{_in_drain};
597		1258
598	} elsif ($! != EAGAIN && $! != EINTR) {	1259	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
599	return $self->error;	1260	return $self->_error ($!, 1);
600	}	1261	}
601
602	$self->_drain_rbuf;
603	});	1262	});
604	}	1263	}
605	}	1264	}
606		1265
		1266	sub _dotls {
		1267	my ($self) = @_;
		1268
		1269	my $buf;
		1270
		1271	if (length $self->{_tls_wbuf}) {
		1272	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1273	substr $self->{_tls_wbuf}, 0, $len, "";
		1274	}
		1275	}
		1276
		1277	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1278	$self->{wbuf} .= $buf;
		1279	$self->_drain_wbuf;
		1280	}
		1281
		1282	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1283	if (length $buf) {
		1284	$self->{rbuf} .= $buf;
		1285	$self->_drain_rbuf unless $self->{_in_drain};
		1286	} else {
		1287	# let's treat SSL-eof as we treat normal EOF
		1288	$self->{_eof} = 1;
		1289	$self->_shutdown;
		1290	return;
		1291	}
		1292	}
		1293
		1294	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1295
		1296	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1297	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1298	return $self->_error ($!, 1);
		1299	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1300	return $self->_error (&Errno::EIO, 1);
		1301	}
		1302
		1303	# all others are fine for our purposes
		1304	}
		1305	}
		1306
		1307	=item $handle->starttls ($tls[, $tls_ctx])
		1308
		1309	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1310	object is created, you can also do that at a later time by calling
		1311	C<starttls>.
		1312
		1313	The first argument is the same as the C<tls> constructor argument (either
		1314	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1315
		1316	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1317	used when AnyEvent::Handle has to create its own TLS connection object.
		1318
		1319	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1320	call and can be used or changed to your liking. Note that the handshake
		1321	might have already started when this function returns.
		1322
		1323	=cut
		1324
		1325	sub starttls {
		1326	my ($self, $ssl, $ctx) = @_;
		1327
		1328	$self->stoptls;
		1329
		1330	if ($ssl eq "accept") {
		1331	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1332	Net::SSLeay::set_accept_state ($ssl);
		1333	} elsif ($ssl eq "connect") {
		1334	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1335	Net::SSLeay::set_connect_state ($ssl);
		1336	}
		1337
		1338	$self->{tls} = $ssl;
		1339
		1340	# basically, this is deep magic (because SSL_read should have the same issues)
		1341	# but the openssl maintainers basically said: "trust us, it just works".
		1342	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1343	# and mismaintained ssleay-module doesn't even offer them).
		1344	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1345	Net::SSLeay::CTX_set_mode ($self->{tls},
		1346	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1347	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1348
		1349	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1350	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1351
		1352	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1353
		1354	$self->{filter_w} = sub {
		1355	$_[0]{_tls_wbuf} .= ${$_[1]};
		1356	&_dotls;
		1357	};
		1358	$self->{filter_r} = sub {
		1359	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1360	&_dotls;
		1361	};
		1362	}
		1363
		1364	=item $handle->stoptls
		1365
		1366	Destroys the SSL connection, if any. Partial read or write data will be
		1367	lost.
		1368
		1369	=cut
		1370
		1371	sub stoptls {
		1372	my ($self) = @_;
		1373
		1374	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1375
		1376	delete $self->{_rbio};
		1377	delete $self->{_wbio};
		1378	delete $self->{_tls_wbuf};
		1379	delete $self->{filter_r};
		1380	delete $self->{filter_w};
		1381	}
		1382
		1383	sub DESTROY {
		1384	my $self = shift;
		1385
		1386	$self->stoptls;
		1387
		1388	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1389
		1390	if ($linger && length $self->{wbuf}) {
		1391	my $fh = delete $self->{fh};
		1392	my $wbuf = delete $self->{wbuf};
		1393
		1394	my @linger;
		1395
		1396	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1397	my $len = syswrite $fh, $wbuf, length $wbuf;
		1398
		1399	if ($len > 0) {
		1400	substr $wbuf, 0, $len, "";
		1401	} else {
		1402	@linger = (); # end
		1403	}
		1404	});
		1405	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1406	@linger = ();
		1407	});
		1408	}
		1409	}
		1410
		1411	=item AnyEvent::Handle::TLS_CTX
		1412
		1413	This function creates and returns the Net::SSLeay::CTX object used by
		1414	default for TLS mode.
		1415
		1416	The context is created like this:
		1417
		1418	Net::SSLeay::load_error_strings;
		1419	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1420	Net::SSLeay::randomize;
		1421
		1422	my $CTX = Net::SSLeay::CTX_new;
		1423
		1424	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1425
		1426	=cut
		1427
		1428	our $TLS_CTX;
		1429
		1430	sub TLS_CTX() {
		1431	$TLS_CTX || do {
		1432	require Net::SSLeay;
		1433
		1434	Net::SSLeay::load_error_strings ();
		1435	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1436	Net::SSLeay::randomize ();
		1437
		1438	$TLS_CTX = Net::SSLeay::CTX_new ();
		1439
		1440	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1441
		1442	$TLS_CTX
		1443	}
		1444	}
		1445
607	=back	1446	=back
608		1447
		1448	=head1 SUBCLASSING AnyEvent::Handle
		1449
		1450	In many cases, you might want to subclass AnyEvent::Handle.
		1451
		1452	To make this easier, a given version of AnyEvent::Handle uses these
		1453	conventions:
		1454
		1455	=over 4
		1456
		1457	=item * all constructor arguments become object members.
		1458
		1459	At least initially, when you pass a C<tls>-argument to the constructor it
		1460	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1461	mutated later on (for example C<tls> will hold the TLS connection object).
		1462
		1463	=item * other object member names are prefixed with an C<_>.
		1464
		1465	All object members not explicitly documented (internal use) are prefixed
		1466	with an underscore character, so the remaining non-C<_>-namespace is free
		1467	for use for subclasses.
		1468
		1469	=item * all members not documented here and not prefixed with an underscore
		1470	are free to use in subclasses.
		1471
		1472	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1473	member variables, but thats just life, at least it is documented.
		1474
		1475	=back
		1476
609	=head1 AUTHOR	1477	=head1 AUTHOR
610		1478
611	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1479	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
612		1480
613	=cut	1481	=cut

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