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Revision 1.11 by root, Sun May 11 17:54:13 2008 UTC vs.
Revision 1.84 by root, Thu Aug 21 19:13:05 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	no warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent ();	6	use AnyEvent ();
7	use AnyEvent::Util ();	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
8	use Scalar::Util ();	8	use Scalar::Util ();
9	use Carp ();	9	use Carp ();
10	use Fcntl ();	10	use Fcntl ();
11	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
12		12
13	=head1 NAME	13	=head1 NAME
14		14
15	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	=cut	17	=cut
18		18
19	our $VERSION = '0.02';	19	our $VERSION = 4.232;
20		20
21	=head1 SYNOPSIS	21	=head1 SYNOPSIS
22		22
23	use AnyEvent;	23	use AnyEvent;
24	use AnyEvent::Handle;	24	use AnyEvent::Handle;
25		25
26	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
27		27
28	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
29
30	#TODO
31
32	# or use the constructor to pass the callback:
33
34	my $ae_fh2 =
35	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
36	fh => \*STDIN,	30	fh => \*STDIN,
37	on_eof => sub {	31	on_eof => sub {
38	$cv->broadcast;	32	$cv->broadcast;
39	},	33	},
40	#TODO
41	);	34	);
42		35
43	$cv->wait;	36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
		41	my ($handle, $line) = @_;
		42	warn "read line <$line>\n";
		43	$cv->send;
		44	});
		45
		46	$cv->recv;
44		47
45	=head1 DESCRIPTION	48	=head1 DESCRIPTION
46		49
47	This module is a helper module to make it easier to do event-based I/O on	50	This module is a helper module to make it easier to do event-based I/O on
48	filehandles (and sockets, see L<AnyEvent::Socket> for an easy way to make	51	filehandles. For utility functions for doing non-blocking connects and accepts
49	non-blocking resolves and connects).	52	on sockets see L<AnyEvent::Util>.
		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
50		56
51	In the following, when the documentation refers to of "bytes" then this	57	In the following, when the documentation refers to of "bytes" then this
52	means characters. As sysread and syswrite are used for all I/O, their	58	means characters. As sysread and syswrite are used for all I/O, their
53	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
54		60
…		…
67		73
68	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
69		75
70	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
71		77
72	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
73	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
74		81
75	=item on_eof => $cb->($self) [MANDATORY]
76
77	Set the callback to be called on EOF.
78
79	=item on_error => $cb->($self)	82	=item on_eof => $cb->($handle)
80		83
		84	Set the callback to be called when an end-of-file condition is detected,
		85	i.e. in the case of a socket, when the other side has closed the
		86	connection cleanly.
		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the eof
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
		93	While not mandatory, it is I<highly> recommended to set an eof callback,
		94	otherwise you might end up with a closed socket while you are still
		95	waiting for data.
		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
		99
		100	=item on_error => $cb->($handle, $fatal)
		101
81	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
82	ocurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
83	or a read error.	104	connect or a read error.
84		105
85	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
86	called.	107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C< ->rbuf >). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
		111
		112	Non-fatal errors can be retried by simply returning, but it is recommended
		113	to simply ignore this parameter and instead abondon the handle object
		114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
87		116
88	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
89	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
90		119
91	While not mandatory, it is I<highly> recommended to set this callback, as	120	While not mandatory, it is I<highly> recommended to set this callback, as
92	you will not be notified of errors otherwise. The default simply calls	121	you will not be notified of errors otherwise. The default simply calls
93	die.	122	C<croak>.
94		123
95	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
96		125
97	This sets the default read callback, which is called when data arrives	126	This sets the default read callback, which is called when data arrives
98	and no read request is in the queue.	127	and no read request is in the queue (unlike read queue callbacks, this
		128	callback will only be called when at least one octet of data is in the
		129	read buffer).
99		130
100	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
101	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
102		133
103	When an EOF condition is detected then AnyEvent::Handle will first try to	134	When an EOF condition is detected then AnyEvent::Handle will first try to
104	feed all the remaining data to the queued callbacks and C<on_read> before	135	feed all the remaining data to the queued callbacks and C<on_read> before
105	calling the C<on_eof> callback. If no progress can be made, then a fatal	136	calling the C<on_eof> callback. If no progress can be made, then a fatal
106	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
107		138
108	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
109		140
110	This sets the callback that is called when the write buffer becomes empty	141	This sets the callback that is called when the write buffer becomes empty
111	(or when the callback is set and the buffer is empty already).	142	(or when the callback is set and the buffer is empty already).
112		143
113	To append to the write buffer, use the C<< ->push_write >> method.	144	To append to the write buffer, use the C<< ->push_write >> method.
		145
		146	This callback is useful when you don't want to put all of your write data
		147	into the queue at once, for example, when you want to write the contents
		148	of some file to the socket you might not want to read the whole file into
		149	memory and push it into the queue, but instead only read more data from
		150	the file when the write queue becomes empty.
		151
		152	=item timeout => $fractional_seconds
		153
		154	If non-zero, then this enables an "inactivity" timeout: whenever this many
		155	seconds pass without a successful read or write on the underlying file
		156	handle, the C<on_timeout> callback will be invoked (and if that one is
		157	missing, an C<ETIMEDOUT> error will be raised).
		158
		159	Note that timeout processing is also active when you currently do not have
		160	any outstanding read or write requests: If you plan to keep the connection
		161	idle then you should disable the timout temporarily or ignore the timeout
		162	in the C<on_timeout> callback.
		163
		164	Zero (the default) disables this timeout.
		165
		166	=item on_timeout => $cb->($handle)
		167
		168	Called whenever the inactivity timeout passes. If you return from this
		169	callback, then the timeout will be reset as if some activity had happened,
		170	so this condition is not fatal in any way.
114		171
115	=item rbuf_max => <bytes>	172	=item rbuf_max => <bytes>
116		173
117	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	174	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
118	when the read buffer ever (strictly) exceeds this size. This is useful to	175	when the read buffer ever (strictly) exceeds this size. This is useful to
…		…
122	be configured to accept only so-and-so much data that it cannot act on	179	be configured to accept only so-and-so much data that it cannot act on
123	(for example, when expecting a line, an attacker could send an unlimited	180	(for example, when expecting a line, an attacker could send an unlimited
124	amount of data without a callback ever being called as long as the line	181	amount of data without a callback ever being called as long as the line
125	isn't finished).	182	isn't finished).
126		183
		184	=item autocork => <boolean>
		185
		186	When disabled (the default), then C<push_write> will try to immediately
		187	write the data to the handle if possible. This avoids having to register
		188	a write watcher and wait for the next event loop iteration, but can be
		189	inefficient if you write multiple small chunks (this disadvantage is
		190	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		191
		192	When enabled, then writes will always be queued till the next event loop
		193	iteration. This is efficient when you do many small writes per iteration,
		194	but less efficient when you do a single write only.
		195
		196	=item no_delay => <boolean>
		197
		198	When doing small writes on sockets, your operating system kernel might
		199	wait a bit for more data before actually sending it out. This is called
		200	the Nagle algorithm, and usually it is beneficial.
		201
		202	In some situations you want as low a delay as possible, which cna be
		203	accomplishd by setting this option to true.
		204
		205	The default is your opertaing system's default behaviour, this option
		206	explicitly enables or disables it, if possible.
		207
127	=item read_size => <bytes>	208	=item read_size => <bytes>
128		209
129	The default read block size (the amount of bytes this module will try to read	210	The default read block size (the amount of bytes this module will try to read
130	on each [loop iteration). Default: C<4096>.	211	during each (loop iteration). Default: C<8192>.
131		212
132	=item low_water_mark => <bytes>	213	=item low_water_mark => <bytes>
133		214
134	Sets the amount of bytes (default: C<0>) that make up an "empty" write	215	Sets the amount of bytes (default: C<0>) that make up an "empty" write
135	buffer: If the write reaches this size or gets even samller it is	216	buffer: If the write reaches this size or gets even samller it is
136	considered empty.	217	considered empty.
137		218
		219	=item linger => <seconds>
		220
		221	If non-zero (default: C<3600>), then the destructor of the
		222	AnyEvent::Handle object will check wether there is still outstanding write
		223	data and will install a watcher that will write out this data. No errors
		224	will be reported (this mostly matches how the operating system treats
		225	outstanding data at socket close time).
		226
		227	This will not work for partial TLS data that could not yet been
		228	encoded. This data will be lost.
		229
		230	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		231
		232	When this parameter is given, it enables TLS (SSL) mode, that means it
		233	will start making tls handshake and will transparently encrypt/decrypt
		234	data.
		235
		236	TLS mode requires Net::SSLeay to be installed (it will be loaded
		237	automatically when you try to create a TLS handle).
		238
		239	For the TLS server side, use C<accept>, and for the TLS client side of a
		240	connection, use C<connect> mode.
		241
		242	You can also provide your own TLS connection object, but you have
		243	to make sure that you call either C<Net::SSLeay::set_connect_state>
		244	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		245	AnyEvent::Handle.
		246
		247	See the C<starttls> method if you need to start TLS negotiation later.
		248
		249	=item tls_ctx => $ssl_ctx
		250
		251	Use the given Net::SSLeay::CTX object to create the new TLS connection
		252	(unless a connection object was specified directly). If this parameter is
		253	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		254
		255	=item json => JSON or JSON::XS object
		256
		257	This is the json coder object used by the C<json> read and write types.
		258
		259	If you don't supply it, then AnyEvent::Handle will create and use a
		260	suitable one, which will write and expect UTF-8 encoded JSON texts.
		261
		262	Note that you are responsible to depend on the JSON module if you want to
		263	use this functionality, as AnyEvent does not have a dependency itself.
		264
		265	=item filter_r => $cb
		266
		267	=item filter_w => $cb
		268
		269	These exist, but are undocumented at this time.
		270
138	=back	271	=back
139		272
140	=cut	273	=cut
141		274
142	sub new {	275	sub new {
…		…
146		279
147	$self->{fh} or Carp::croak "mandatory argument fh is missing";	280	$self->{fh} or Carp::croak "mandatory argument fh is missing";
148		281
149	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	282	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
150		283
151	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	284	if ($self->{tls}) {
		285	require Net::SSLeay;
		286	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		287	}
152		288
153	$self->on_error (delete $self->{on_error}) if $self->{on_error};	289	$self->{_activity} = AnyEvent->now;
		290	$self->_timeout;
		291
154	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	292	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
155	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	293	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
156		294
157	$self->start_read;	295	$self->start_read
		296	if $self->{on_read};
158		297
159	$self	298	$self
160	}	299	}
161		300
162	sub _shutdown {	301	sub _shutdown {
163	my ($self) = @_;	302	my ($self) = @_;
164		303
		304	delete $self->{_tw};
165	delete $self->{rw};	305	delete $self->{_rw};
166	delete $self->{ww};	306	delete $self->{_ww};
167	delete $self->{fh};	307	delete $self->{fh};
168	}
169		308
		309	$self->stoptls;
		310
		311	delete $self->{on_read};
		312	delete $self->{_queue};
		313	}
		314
170	sub error {	315	sub _error {
171	my ($self) = @_;	316	my ($self, $errno, $fatal) = @_;
172		317
173	{
174	local $!;
175	$self->_shutdown;	318	$self->_shutdown
176	}	319	if $fatal;
		320
		321	$! = $errno;
177		322
178	if ($self->{on_error}) {	323	if ($self->{on_error}) {
179	$self->{on_error}($self);	324	$self->{on_error}($self, $fatal);
180	} else {	325	} else {
181	die "AnyEvent::Handle uncaught fatal error: $!";	326	Carp::croak "AnyEvent::Handle uncaught error: $!";
182	}	327	}
183	}	328	}
184		329
185	=item $fh = $handle->fh	330	=item $fh = $handle->fh
186		331
187	This method returns the filehandle of the L<AnyEvent::Handle> object.	332	This method returns the file handle of the L<AnyEvent::Handle> object.
188		333
189	=cut	334	=cut
190		335
191	sub fh { $_[0]->{fh} }	336	sub fh { $_[0]{fh} }
192		337
193	=item $handle->on_error ($cb)	338	=item $handle->on_error ($cb)
194		339
195	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	340	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
196		341
…		…
208		353
209	sub on_eof {	354	sub on_eof {
210	$_[0]{on_eof} = $_[1];	355	$_[0]{on_eof} = $_[1];
211	}	356	}
212		357
		358	=item $handle->on_timeout ($cb)
		359
		360	Replace the current C<on_timeout> callback, or disables the callback
		361	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		362	argument.
		363
		364	=cut
		365
		366	sub on_timeout {
		367	$_[0]{on_timeout} = $_[1];
		368	}
		369
		370	=item $handle->autocork ($boolean)
		371
		372	Enables or disables the current autocork behaviour (see C<autocork>
		373	constructor argument).
		374
		375	=cut
		376
		377	=item $handle->no_delay ($boolean)
		378
		379	Enables or disables the C<no_delay> setting (see constructor argument of
		380	the same name for details).
		381
		382	=cut
		383
		384	sub no_delay {
		385	$_[0]{no_delay} = $_[1];
		386
		387	eval {
		388	local $SIG{__DIE__};
		389	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		390	};
		391	}
		392
		393	#############################################################################
		394
		395	=item $handle->timeout ($seconds)
		396
		397	Configures (or disables) the inactivity timeout.
		398
		399	=cut
		400
		401	sub timeout {
		402	my ($self, $timeout) = @_;
		403
		404	$self->{timeout} = $timeout;
		405	$self->_timeout;
		406	}
		407
		408	# reset the timeout watcher, as neccessary
		409	# also check for time-outs
		410	sub _timeout {
		411	my ($self) = @_;
		412
		413	if ($self->{timeout}) {
		414	my $NOW = AnyEvent->now;
		415
		416	# when would the timeout trigger?
		417	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		418
		419	# now or in the past already?
		420	if ($after <= 0) {
		421	$self->{_activity} = $NOW;
		422
		423	if ($self->{on_timeout}) {
		424	$self->{on_timeout}($self);
		425	} else {
		426	$self->_error (&Errno::ETIMEDOUT);
		427	}
		428
		429	# callback could have changed timeout value, optimise
		430	return unless $self->{timeout};
		431
		432	# calculate new after
		433	$after = $self->{timeout};
		434	}
		435
		436	Scalar::Util::weaken $self;
		437	return unless $self; # ->error could have destroyed $self
		438
		439	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		440	delete $self->{_tw};
		441	$self->_timeout;
		442	});
		443	} else {
		444	delete $self->{_tw};
		445	}
		446	}
		447
213	#############################################################################	448	#############################################################################
214		449
215	=back	450	=back
216		451
217	=head2 WRITE QUEUE	452	=head2 WRITE QUEUE
…		…
220	for reading.	455	for reading.
221		456
222	The write queue is very simple: you can add data to its end, and	457	The write queue is very simple: you can add data to its end, and
223	AnyEvent::Handle will automatically try to get rid of it for you.	458	AnyEvent::Handle will automatically try to get rid of it for you.
224		459
225	When data could be writtena nd the write buffer is shorter then the low	460	When data could be written and the write buffer is shorter then the low
226	water mark, the C<on_drain> callback will be invoked.	461	water mark, the C<on_drain> callback will be invoked.
227		462
228	=over 4	463	=over 4
229		464
230	=item $handle->on_drain ($cb)	465	=item $handle->on_drain ($cb)
…		…
249	want (only limited by the available memory), as C<AnyEvent::Handle>	484	want (only limited by the available memory), as C<AnyEvent::Handle>
250	buffers it independently of the kernel.	485	buffers it independently of the kernel.
251		486
252	=cut	487	=cut
253		488
254	sub push_write {	489	sub _drain_wbuf {
255	my ($self, $data) = @_;	490	my ($self) = @_;
256		491
257	$self->{wbuf} .= $data;	492	if (!$self->{_ww} && length $self->{wbuf}) {
258		493
259	unless ($self->{ww}) {
260	Scalar::Util::weaken $self;	494	Scalar::Util::weaken $self;
		495
261	my $cb = sub {	496	my $cb = sub {
262	my $len = syswrite $self->{fh}, $self->{wbuf};	497	my $len = syswrite $self->{fh}, $self->{wbuf};
263		498
264	if ($len > 0) {	499	if ($len >= 0) {
265	substr $self->{wbuf}, 0, $len, "";	500	substr $self->{wbuf}, 0, $len, "";
266		501
		502	$self->{_activity} = AnyEvent->now;
267		503
268	$self->{on_drain}($self)	504	$self->{on_drain}($self)
269	if $self->{low_water_mark} >= length $self->{wbuf}	505	if $self->{low_water_mark} >= length $self->{wbuf}
270	&& $self->{on_drain};	506	&& $self->{on_drain};
271		507
272	delete $self->{ww} unless length $self->{wbuf};	508	delete $self->{_ww} unless length $self->{wbuf};
273	} elsif ($! != EAGAIN && $! != EINTR) {	509	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
274	$self->error;	510	$self->_error ($!, 1);
275	}	511	}
276	};	512	};
277		513
		514	# try to write data immediately
		515	$cb->() unless $self->{autocork};
		516
		517	# if still data left in wbuf, we need to poll
278	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	518	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
279		519	if length $self->{wbuf};
280	$cb->($self);
281	};	520	};
282	}	521	}
		522
		523	our %WH;
		524
		525	sub register_write_type($$) {
		526	$WH{$_[0]} = $_[1];
		527	}
		528
		529	sub push_write {
		530	my $self = shift;
		531
		532	if (@_ > 1) {
		533	my $type = shift;
		534
		535	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		536	->($self, @_);
		537	}
		538
		539	if ($self->{filter_w}) {
		540	$self->{filter_w}($self, \$_[0]);
		541	} else {
		542	$self->{wbuf} .= $_[0];
		543	$self->_drain_wbuf;
		544	}
		545	}
		546
		547	=item $handle->push_write (type => @args)
		548
		549	Instead of formatting your data yourself, you can also let this module do
		550	the job by specifying a type and type-specific arguments.
		551
		552	Predefined types are (if you have ideas for additional types, feel free to
		553	drop by and tell us):
		554
		555	=over 4
		556
		557	=item netstring => $string
		558
		559	Formats the given value as netstring
		560	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		561
		562	=cut
		563
		564	register_write_type netstring => sub {
		565	my ($self, $string) = @_;
		566
		567	sprintf "%d:%s,", (length $string), $string
		568	};
		569
		570	=item packstring => $format, $data
		571
		572	An octet string prefixed with an encoded length. The encoding C<$format>
		573	uses the same format as a Perl C<pack> format, but must specify a single
		574	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		575	optional C<!>, C<< < >> or C<< > >> modifier).
		576
		577	=cut
		578
		579	register_write_type packstring => sub {
		580	my ($self, $format, $string) = @_;
		581
		582	pack "$format/a*", $string
		583	};
		584
		585	=item json => $array_or_hashref
		586
		587	Encodes the given hash or array reference into a JSON object. Unless you
		588	provide your own JSON object, this means it will be encoded to JSON text
		589	in UTF-8.
		590
		591	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		592	one end of a handle and read them at the other end without using any
		593	additional framing.
		594
		595	The generated JSON text is guaranteed not to contain any newlines: While
		596	this module doesn't need delimiters after or between JSON texts to be
		597	able to read them, many other languages depend on that.
		598
		599	A simple RPC protocol that interoperates easily with others is to send
		600	JSON arrays (or objects, although arrays are usually the better choice as
		601	they mimic how function argument passing works) and a newline after each
		602	JSON text:
		603
		604	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		605	$handle->push_write ("\012");
		606
		607	An AnyEvent::Handle receiver would simply use the C<json> read type and
		608	rely on the fact that the newline will be skipped as leading whitespace:
		609
		610	$handle->push_read (json => sub { my $array = $_[1]; ... });
		611
		612	Other languages could read single lines terminated by a newline and pass
		613	this line into their JSON decoder of choice.
		614
		615	=cut
		616
		617	register_write_type json => sub {
		618	my ($self, $ref) = @_;
		619
		620	require JSON;
		621
		622	$self->{json} ? $self->{json}->encode ($ref)
		623	: JSON::encode_json ($ref)
		624	};
		625
		626	=item storable => $reference
		627
		628	Freezes the given reference using L<Storable> and writes it to the
		629	handle. Uses the C<nfreeze> format.
		630
		631	=cut
		632
		633	register_write_type storable => sub {
		634	my ($self, $ref) = @_;
		635
		636	require Storable;
		637
		638	pack "w/a*", Storable::nfreeze ($ref)
		639	};
		640
		641	=back
		642
		643	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		644
		645	This function (not method) lets you add your own types to C<push_write>.
		646	Whenever the given C<type> is used, C<push_write> will invoke the code
		647	reference with the handle object and the remaining arguments.
		648
		649	The code reference is supposed to return a single octet string that will
		650	be appended to the write buffer.
		651
		652	Note that this is a function, and all types registered this way will be
		653	global, so try to use unique names.
		654
		655	=cut
283		656
284	#############################################################################	657	#############################################################################
285		658
286	=back	659	=back
287		660
…		…
294	ways, the "simple" way, using only C<on_read> and the "complex" way, using	667	ways, the "simple" way, using only C<on_read> and the "complex" way, using
295	a queue.	668	a queue.
296		669
297	In the simple case, you just install an C<on_read> callback and whenever	670	In the simple case, you just install an C<on_read> callback and whenever
298	new data arrives, it will be called. You can then remove some data (if	671	new data arrives, it will be called. You can then remove some data (if
299	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	672	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
300	or not.	673	leave the data there if you want to accumulate more (e.g. when only a
		674	partial message has been received so far).
301		675
302	In the more complex case, you want to queue multiple callbacks. In this	676	In the more complex case, you want to queue multiple callbacks. In this
303	case, AnyEvent::Handle will call the first queued callback each time new	677	case, AnyEvent::Handle will call the first queued callback each time new
304	data arrives and removes it when it has done its job (see C<push_read>,	678	data arrives (also the first time it is queued) and removes it when it has
305	below).	679	done its job (see C<push_read>, below).
306		680
307	This way you can, for example, push three line-reads, followed by reading	681	This way you can, for example, push three line-reads, followed by reading
308	a chunk of data, and AnyEvent::Handle will execute them in order.	682	a chunk of data, and AnyEvent::Handle will execute them in order.
309		683
310	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	684	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
311	the specified number of bytes which give an XML datagram.	685	the specified number of bytes which give an XML datagram.
312		686
313	# in the default state, expect some header bytes	687	# in the default state, expect some header bytes
314	$handle->on_read (sub {	688	$handle->on_read (sub {
315	# some data is here, now queue the length-header-read (4 octets)	689	# some data is here, now queue the length-header-read (4 octets)
316	shift->unshift_read_chunk (4, sub {	690	shift->unshift_read (chunk => 4, sub {
317	# header arrived, decode	691	# header arrived, decode
318	my $len = unpack "N", $_[1];	692	my $len = unpack "N", $_[1];
319		693
320	# now read the payload	694	# now read the payload
321	shift->unshift_read_chunk ($len, sub {	695	shift->unshift_read (chunk => $len, sub {
322	my $xml = $_[1];	696	my $xml = $_[1];
323	# handle xml	697	# handle xml
324	});	698	});
325	});	699	});
326	});	700	});
327		701
328	Example 2: Implement a client for a protocol that replies either with	702	Example 2: Implement a client for a protocol that replies either with "OK"
329	"OK" and another line or "ERROR" for one request, and 64 bytes for the	703	and another line or "ERROR" for the first request that is sent, and 64
330	second request. Due tot he availability of a full queue, we can just	704	bytes for the second request. Due to the availability of a queue, we can
331	pipeline sending both requests and manipulate the queue as necessary in	705	just pipeline sending both requests and manipulate the queue as necessary
332	the callbacks:	706	in the callbacks.
333		707
334	# request one	708	When the first callback is called and sees an "OK" response, it will
		709	C<unshift> another line-read. This line-read will be queued I<before> the
		710	64-byte chunk callback.
		711
		712	# request one, returns either "OK + extra line" or "ERROR"
335	$handle->push_write ("request 1\015\012");	713	$handle->push_write ("request 1\015\012");
336		714
337	# we expect "ERROR" or "OK" as response, so push a line read	715	# we expect "ERROR" or "OK" as response, so push a line read
338	$handle->push_read_line (sub {	716	$handle->push_read (line => sub {
339	# if we got an "OK", we have to _prepend_ another line,	717	# if we got an "OK", we have to _prepend_ another line,
340	# so it will be read before the second request reads its 64 bytes	718	# so it will be read before the second request reads its 64 bytes
341	# which are already in the queue when this callback is called	719	# which are already in the queue when this callback is called
342	# we don't do this in case we got an error	720	# we don't do this in case we got an error
343	if ($_[1] eq "OK") {	721	if ($_[1] eq "OK") {
344	$_[0]->unshift_read_line (sub {	722	$_[0]->unshift_read (line => sub {
345	my $response = $_[1];	723	my $response = $_[1];
346	...	724	...
347	});	725	});
348	}	726	}
349	});	727	});
350		728
351	# request two	729	# request two, simply returns 64 octets
352	$handle->push_write ("request 2\015\012");	730	$handle->push_write ("request 2\015\012");
353		731
354	# simply read 64 bytes, always	732	# simply read 64 bytes, always
355	$handle->push_read_chunk (64, sub {	733	$handle->push_read (chunk => 64, sub {
356	my $response = $_[1];	734	my $response = $_[1];
357	...	735	...
358	});	736	});
359		737
360	=over 4	738	=over 4
…		…
362	=cut	740	=cut
363		741
364	sub _drain_rbuf {	742	sub _drain_rbuf {
365	my ($self) = @_;	743	my ($self) = @_;
366		744
367	return if $self->{in_drain};
368	local $self->{in_drain} = 1;	745	local $self->{_in_drain} = 1;
369		746
		747	if (
		748	defined $self->{rbuf_max}
		749	&& $self->{rbuf_max} < length $self->{rbuf}
		750	) {
		751	$self->_error (&Errno::ENOSPC, 1), return;
		752	}
		753
		754	while () {
370	while (my $len = length $self->{rbuf}) {	755	my $len = length $self->{rbuf};
371	no strict 'refs';	756
372	if (my $cb = shift @{ $self->{queue} }) {	757	if (my $cb = shift @{ $self->{_queue} }) {
373	if (!$cb->($self)) {	758	unless ($cb->($self)) {
374	if ($self->{eof}) {	759	if ($self->{_eof}) {
375	# no progress can be made (not enough data and no data forthcoming)	760	# no progress can be made (not enough data and no data forthcoming)
376	$! = &Errno::EPIPE; return $self->error;	761	$self->_error (&Errno::EPIPE, 1), return;
377	}	762	}
378		763
379	unshift @{ $self->{queue} }, $cb;	764	unshift @{ $self->{_queue} }, $cb;
380	return;	765	last;
381	}	766	}
382	} elsif ($self->{on_read}) {	767	} elsif ($self->{on_read}) {
		768	last unless $len;
		769
383	$self->{on_read}($self);	770	$self->{on_read}($self);
384		771
385	if (	772	if (
386	$self->{eof} # if no further data will arrive
387	&& $len == length $self->{rbuf} # and no data has been consumed	773	$len == length $self->{rbuf} # if no data has been consumed
388	&& !@{ $self->{queue} } # and the queue is still empty	774	&& !@{ $self->{_queue} } # and the queue is still empty
389	&& $self->{on_read} # and we still want to read data	775	&& $self->{on_read} # but we still have on_read
390	) {	776	) {
		777	# no further data will arrive
391	# then no progress can be made	778	# so no progress can be made
392	$! = &Errno::EPIPE; return $self->error;	779	$self->_error (&Errno::EPIPE, 1), return
		780	if $self->{_eof};
		781
		782	last; # more data might arrive
393	}	783	}
394	} else {	784	} else {
395	# read side becomes idle	785	# read side becomes idle
396	delete $self->{rw};	786	delete $self->{_rw};
397	return;	787	last;
398	}	788	}
399	}	789	}
400		790
401	if ($self->{eof}) {	791	if ($self->{_eof}) {
402	$self->_shutdown;	792	if ($self->{on_eof}) {
403	$self->{on_eof}($self);	793	$self->{on_eof}($self)
		794	} else {
		795	$self->_error (0, 1);
		796	}
		797	}
		798
		799	# may need to restart read watcher
		800	unless ($self->{_rw}) {
		801	$self->start_read
		802	if $self->{on_read} || @{ $self->{_queue} };
404	}	803	}
405	}	804	}
406		805
407	=item $handle->on_read ($cb)	806	=item $handle->on_read ($cb)
408		807
…		…
414		813
415	sub on_read {	814	sub on_read {
416	my ($self, $cb) = @_;	815	my ($self, $cb) = @_;
417		816
418	$self->{on_read} = $cb;	817	$self->{on_read} = $cb;
		818	$self->_drain_rbuf if $cb && !$self->{_in_drain};
419	}	819	}
420		820
421	=item $handle->rbuf	821	=item $handle->rbuf
422		822
423	Returns the read buffer (as a modifiable lvalue).	823	Returns the read buffer (as a modifiable lvalue).
…		…
442	Append the given callback to the end of the queue (C<push_read>) or	842	Append the given callback to the end of the queue (C<push_read>) or
443	prepend it (C<unshift_read>).	843	prepend it (C<unshift_read>).
444		844
445	The callback is called each time some additional read data arrives.	845	The callback is called each time some additional read data arrives.
446		846
447	It must check wether enough data is in the read buffer already.	847	It must check whether enough data is in the read buffer already.
448		848
449	If not enough data is available, it must return the empty list or a false	849	If not enough data is available, it must return the empty list or a false
450	value, in which case it will be called repeatedly until enough data is	850	value, in which case it will be called repeatedly until enough data is
451	available (or an error condition is detected).	851	available (or an error condition is detected).
452		852
…		…
454	interested in (which can be none at all) and return a true value. After returning	854	interested in (which can be none at all) and return a true value. After returning
455	true, it will be removed from the queue.	855	true, it will be removed from the queue.
456		856
457	=cut	857	=cut
458		858
		859	our %RH;
		860
		861	sub register_read_type($$) {
		862	$RH{$_[0]} = $_[1];
		863	}
		864
459	sub push_read {	865	sub push_read {
460	my ($self, $cb) = @_;	866	my $self = shift;
		867	my $cb = pop;
461		868
		869	if (@_) {
		870	my $type = shift;
		871
		872	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		873	->($self, $cb, @_);
		874	}
		875
462	push @{ $self->{queue} }, $cb;	876	push @{ $self->{_queue} }, $cb;
463	$self->_drain_rbuf;	877	$self->_drain_rbuf unless $self->{_in_drain};
464	}	878	}
465		879
466	sub unshift_read {	880	sub unshift_read {
467	my ($self, $cb) = @_;	881	my $self = shift;
		882	my $cb = pop;
468		883
		884	if (@_) {
		885	my $type = shift;
		886
		887	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		888	->($self, $cb, @_);
		889	}
		890
		891
469	push @{ $self->{queue} }, $cb;	892	unshift @{ $self->{_queue} }, $cb;
470	$self->_drain_rbuf;	893	$self->_drain_rbuf unless $self->{_in_drain};
471	}	894	}
472		895
473	=item $handle->push_read_chunk ($len, $cb->($self, $data))	896	=item $handle->push_read (type => @args, $cb)
474		897
475	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	898	=item $handle->unshift_read (type => @args, $cb)
476		899
477	Append the given callback to the end of the queue (C<push_read_chunk>) or	900	Instead of providing a callback that parses the data itself you can chose
478	prepend it (C<unshift_read_chunk>).	901	between a number of predefined parsing formats, for chunks of data, lines
		902	etc.
479		903
480	The callback will be called only once C<$len> bytes have been read, and	904	Predefined types are (if you have ideas for additional types, feel free to
481	these C<$len> bytes will be passed to the callback.	905	drop by and tell us):
482		906
483	=cut	907	=over 4
484		908
485	sub _read_chunk($$) {	909	=item chunk => $octets, $cb->($handle, $data)
		910
		911	Invoke the callback only once C<$octets> bytes have been read. Pass the
		912	data read to the callback. The callback will never be called with less
		913	data.
		914
		915	Example: read 2 bytes.
		916
		917	$handle->push_read (chunk => 2, sub {
		918	warn "yay ", unpack "H*", $_[1];
		919	});
		920
		921	=cut
		922
		923	register_read_type chunk => sub {
486	my ($self, $len, $cb) = @_;	924	my ($self, $cb, $len) = @_;
487		925
488	sub {	926	sub {
489	$len <= length $_[0]{rbuf} or return;	927	$len <= length $_[0]{rbuf} or return;
490	$cb->($self, $_[0], substr $_[0]{rbuf}, 0, $len, "");	928	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
491	1	929	1
492	}	930	}
493	}	931	};
494		932
495	sub push_read_chunk {	933	=item line => [$eol, ]$cb->($handle, $line, $eol)
496	$_[0]->push_read (&_read_chunk);
497	}
498
499
500	sub unshift_read_chunk {
501	$_[0]->unshift_read (&_read_chunk);
502	}
503
504	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
505
506	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
507
508	Append the given callback to the end of the queue (C<push_read_line>) or
509	prepend it (C<unshift_read_line>).
510		934
511	The callback will be called only once a full line (including the end of	935	The callback will be called only once a full line (including the end of
512	line marker, C<$eol>) has been read. This line (excluding the end of line	936	line marker, C<$eol>) has been read. This line (excluding the end of line
513	marker) will be passed to the callback as second argument (C<$line>), and	937	marker) will be passed to the callback as second argument (C<$line>), and
514	the end of line marker as the third argument (C<$eol>).	938	the end of line marker as the third argument (C<$eol>).
…		…
525	Partial lines at the end of the stream will never be returned, as they are	949	Partial lines at the end of the stream will never be returned, as they are
526	not marked by the end of line marker.	950	not marked by the end of line marker.
527		951
528	=cut	952	=cut
529		953
530	sub _read_line($$) {	954	register_read_type line => sub {
531	my $self = shift;	955	my ($self, $cb, $eol) = @_;
532	my $cb = pop;
533	my $eol = @_ ? shift : qr|(\015?\012)|;
534	my $pos;
535		956
		957	if (@_ < 3) {
		958	# this is more than twice as fast as the generic code below
		959	sub {
		960	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		961
		962	$cb->($_[0], $1, $2);
		963	1
		964	}
		965	} else {
536	$eol = qr|(\Q$eol\E)| unless ref $eol;	966	$eol = quotemeta $eol unless ref $eol;
537	$eol = qr|^(.*?)($eol)|;	967	$eol = qr|^(.*?)($eol)|s;
		968
		969	sub {
		970	$_[0]{rbuf} =~ s/$eol// or return;
		971
		972	$cb->($_[0], $1, $2);
		973	1
		974	}
		975	}
		976	};
		977
		978	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		979
		980	Makes a regex match against the regex object C<$accept> and returns
		981	everything up to and including the match.
		982
		983	Example: read a single line terminated by '\n'.
		984
		985	$handle->push_read (regex => qr<\n>, sub { ... });
		986
		987	If C<$reject> is given and not undef, then it determines when the data is
		988	to be rejected: it is matched against the data when the C<$accept> regex
		989	does not match and generates an C<EBADMSG> error when it matches. This is
		990	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		991	receive buffer overflow).
		992
		993	Example: expect a single decimal number followed by whitespace, reject
		994	anything else (not the use of an anchor).
		995
		996	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		997
		998	If C<$skip> is given and not C<undef>, then it will be matched against
		999	the receive buffer when neither C<$accept> nor C<$reject> match,
		1000	and everything preceding and including the match will be accepted
		1001	unconditionally. This is useful to skip large amounts of data that you
		1002	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1003	have to start matching from the beginning. This is purely an optimisation
		1004	and is usually worth only when you expect more than a few kilobytes.
		1005
		1006	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1007	expect the header to be very large (it isn't in practise, but...), we use
		1008	a skip regex to skip initial portions. The skip regex is tricky in that
		1009	it only accepts something not ending in either \015 or \012, as these are
		1010	required for the accept regex.
		1011
		1012	$handle->push_read (regex =>
		1013	qr<\015\012\015\012>,
		1014	undef, # no reject
		1015	qr<^.*[^\015\012]>,
		1016	sub { ... });
		1017
		1018	=cut
		1019
		1020	register_read_type regex => sub {
		1021	my ($self, $cb, $accept, $reject, $skip) = @_;
		1022
		1023	my $data;
		1024	my $rbuf = \$self->{rbuf};
538		1025
539	sub {	1026	sub {
540	$_[0]{rbuf} =~ s/$eol// or return;	1027	# accept
541		1028	if ($$rbuf =~ $accept) {
		1029	$data .= substr $$rbuf, 0, $+[0], "";
542	$cb->($self, $1, $2);	1030	$cb->($self, $data);
		1031	return 1;
		1032	}
		1033
		1034	# reject
		1035	if ($reject && $$rbuf =~ $reject) {
		1036	$self->_error (&Errno::EBADMSG);
		1037	}
		1038
		1039	# skip
		1040	if ($skip && $$rbuf =~ $skip) {
		1041	$data .= substr $$rbuf, 0, $+[0], "";
		1042	}
		1043
		1044	()
		1045	}
		1046	};
		1047
		1048	=item netstring => $cb->($handle, $string)
		1049
		1050	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1051
		1052	Throws an error with C<$!> set to EBADMSG on format violations.
		1053
		1054	=cut
		1055
		1056	register_read_type netstring => sub {
		1057	my ($self, $cb) = @_;
		1058
		1059	sub {
		1060	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1061	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1062	$self->_error (&Errno::EBADMSG);
		1063	}
		1064	return;
		1065	}
		1066
		1067	my $len = $1;
		1068
		1069	$self->unshift_read (chunk => $len, sub {
		1070	my $string = $_[1];
		1071	$_[0]->unshift_read (chunk => 1, sub {
		1072	if ($_[1] eq ",") {
		1073	$cb->($_[0], $string);
		1074	} else {
		1075	$self->_error (&Errno::EBADMSG);
		1076	}
		1077	});
		1078	});
		1079
543	1	1080	1
544	}	1081	}
545	}	1082	};
546		1083
547	sub push_read_line {	1084	=item packstring => $format, $cb->($handle, $string)
548	$_[0]->push_read (&_read_line);
549	}
550		1085
551	sub unshift_read_line {	1086	An octet string prefixed with an encoded length. The encoding C<$format>
552	$_[0]->unshift_read (&_read_line);	1087	uses the same format as a Perl C<pack> format, but must specify a single
553	}	1088	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1089	optional C<!>, C<< < >> or C<< > >> modifier).
		1090
		1091	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1092
		1093	Example: read a block of data prefixed by its length in BER-encoded
		1094	format (very efficient).
		1095
		1096	$handle->push_read (packstring => "w", sub {
		1097	my ($handle, $data) = @_;
		1098	});
		1099
		1100	=cut
		1101
		1102	register_read_type packstring => sub {
		1103	my ($self, $cb, $format) = @_;
		1104
		1105	sub {
		1106	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1107	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1108	or return;
		1109
		1110	$format = length pack $format, $len;
		1111
		1112	# bypass unshift if we already have the remaining chunk
		1113	if ($format + $len <= length $_[0]{rbuf}) {
		1114	my $data = substr $_[0]{rbuf}, $format, $len;
		1115	substr $_[0]{rbuf}, 0, $format + $len, "";
		1116	$cb->($_[0], $data);
		1117	} else {
		1118	# remove prefix
		1119	substr $_[0]{rbuf}, 0, $format, "";
		1120
		1121	# read remaining chunk
		1122	$_[0]->unshift_read (chunk => $len, $cb);
		1123	}
		1124
		1125	1
		1126	}
		1127	};
		1128
		1129	=item json => $cb->($handle, $hash_or_arrayref)
		1130
		1131	Reads a JSON object or array, decodes it and passes it to the callback.
		1132
		1133	If a C<json> object was passed to the constructor, then that will be used
		1134	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1135
		1136	This read type uses the incremental parser available with JSON version
		1137	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1138	dependency on your own: this module will load the JSON module, but
		1139	AnyEvent does not depend on it itself.
		1140
		1141	Since JSON texts are fully self-delimiting, the C<json> read and write
		1142	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1143	the C<json> write type description, above, for an actual example.
		1144
		1145	=cut
		1146
		1147	register_read_type json => sub {
		1148	my ($self, $cb) = @_;
		1149
		1150	require JSON;
		1151
		1152	my $data;
		1153	my $rbuf = \$self->{rbuf};
		1154
		1155	my $json = $self->{json} ||= JSON->new->utf8;
		1156
		1157	sub {
		1158	my $ref = $json->incr_parse ($self->{rbuf});
		1159
		1160	if ($ref) {
		1161	$self->{rbuf} = $json->incr_text;
		1162	$json->incr_text = "";
		1163	$cb->($self, $ref);
		1164
		1165	1
		1166	} else {
		1167	$self->{rbuf} = "";
		1168	()
		1169	}
		1170	}
		1171	};
		1172
		1173	=item storable => $cb->($handle, $ref)
		1174
		1175	Deserialises a L<Storable> frozen representation as written by the
		1176	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1177	data).
		1178
		1179	Raises C<EBADMSG> error if the data could not be decoded.
		1180
		1181	=cut
		1182
		1183	register_read_type storable => sub {
		1184	my ($self, $cb) = @_;
		1185
		1186	require Storable;
		1187
		1188	sub {
		1189	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1190	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1191	or return;
		1192
		1193	my $format = length pack "w", $len;
		1194
		1195	# bypass unshift if we already have the remaining chunk
		1196	if ($format + $len <= length $_[0]{rbuf}) {
		1197	my $data = substr $_[0]{rbuf}, $format, $len;
		1198	substr $_[0]{rbuf}, 0, $format + $len, "";
		1199	$cb->($_[0], Storable::thaw ($data));
		1200	} else {
		1201	# remove prefix
		1202	substr $_[0]{rbuf}, 0, $format, "";
		1203
		1204	# read remaining chunk
		1205	$_[0]->unshift_read (chunk => $len, sub {
		1206	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1207	$cb->($_[0], $ref);
		1208	} else {
		1209	$self->_error (&Errno::EBADMSG);
		1210	}
		1211	});
		1212	}
		1213
		1214	1
		1215	}
		1216	};
		1217
		1218	=back
		1219
		1220	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1221
		1222	This function (not method) lets you add your own types to C<push_read>.
		1223
		1224	Whenever the given C<type> is used, C<push_read> will invoke the code
		1225	reference with the handle object, the callback and the remaining
		1226	arguments.
		1227
		1228	The code reference is supposed to return a callback (usually a closure)
		1229	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1230
		1231	It should invoke the passed callback when it is done reading (remember to
		1232	pass C<$handle> as first argument as all other callbacks do that).
		1233
		1234	Note that this is a function, and all types registered this way will be
		1235	global, so try to use unique names.
		1236
		1237	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1238	search for C<register_read_type>)).
554		1239
555	=item $handle->stop_read	1240	=item $handle->stop_read
556		1241
557	=item $handle->start_read	1242	=item $handle->start_read
558		1243
559	In rare cases you actually do not want to read anything form the	1244	In rare cases you actually do not want to read anything from the
560	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1245	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
561	any queued callbacks will be executed then. To start readign again, call	1246	any queued callbacks will be executed then. To start reading again, call
562	C<start_read>.	1247	C<start_read>.
		1248
		1249	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1250	you change the C<on_read> callback or push/unshift a read callback, and it
		1251	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1252	there are any read requests in the queue.
563		1253
564	=cut	1254	=cut
565		1255
566	sub stop_read {	1256	sub stop_read {
567	my ($self) = @_;	1257	my ($self) = @_;
568		1258
569	delete $self->{rw};	1259	delete $self->{_rw};
570	}	1260	}
571		1261
572	sub start_read {	1262	sub start_read {
573	my ($self) = @_;	1263	my ($self) = @_;
574		1264
575	unless ($self->{rw} || $self->{eof}) {	1265	unless ($self->{_rw} || $self->{_eof}) {
576	Scalar::Util::weaken $self;	1266	Scalar::Util::weaken $self;
577		1267
578	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1268	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1269	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
579	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1270	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
580		1271
581	if ($len > 0) {	1272	if ($len > 0) {
582	if (defined $self->{rbuf_max}) {	1273	$self->{_activity} = AnyEvent->now;
583	if ($self->{rbuf_max} < length $self->{rbuf}) {	1274
584	$! = &Errno::ENOSPC; return $self->error;	1275	$self->{filter_r}
585	}	1276	? $self->{filter_r}($self, $rbuf)
586	}	1277	: $self->{_in_drain} || $self->_drain_rbuf;
587		1278
588	} elsif (defined $len) {	1279	} elsif (defined $len) {
589	$self->{eof} = 1;
590	delete $self->{rw};	1280	delete $self->{_rw};
		1281	$self->{_eof} = 1;
		1282	$self->_drain_rbuf unless $self->{_in_drain};
591		1283
592	} elsif ($! != EAGAIN && $! != EINTR) {	1284	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
593	return $self->error;	1285	return $self->_error ($!, 1);
594	}	1286	}
595
596	$self->_drain_rbuf;
597	});	1287	});
598	}	1288	}
599	}	1289	}
600		1290
		1291	sub _dotls {
		1292	my ($self) = @_;
		1293
		1294	my $buf;
		1295
		1296	if (length $self->{_tls_wbuf}) {
		1297	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1298	substr $self->{_tls_wbuf}, 0, $len, "";
		1299	}
		1300	}
		1301
		1302	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1303	$self->{wbuf} .= $buf;
		1304	$self->_drain_wbuf;
		1305	}
		1306
		1307	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1308	if (length $buf) {
		1309	$self->{rbuf} .= $buf;
		1310	$self->_drain_rbuf unless $self->{_in_drain};
		1311	} else {
		1312	# let's treat SSL-eof as we treat normal EOF
		1313	$self->{_eof} = 1;
		1314	$self->_shutdown;
		1315	return;
		1316	}
		1317	}
		1318
		1319	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1320
		1321	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1322	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1323	return $self->_error ($!, 1);
		1324	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1325	return $self->_error (&Errno::EIO, 1);
		1326	}
		1327
		1328	# all others are fine for our purposes
		1329	}
		1330	}
		1331
		1332	=item $handle->starttls ($tls[, $tls_ctx])
		1333
		1334	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1335	object is created, you can also do that at a later time by calling
		1336	C<starttls>.
		1337
		1338	The first argument is the same as the C<tls> constructor argument (either
		1339	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1340
		1341	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1342	used when AnyEvent::Handle has to create its own TLS connection object.
		1343
		1344	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1345	call and can be used or changed to your liking. Note that the handshake
		1346	might have already started when this function returns.
		1347
		1348	=cut
		1349
		1350	sub starttls {
		1351	my ($self, $ssl, $ctx) = @_;
		1352
		1353	$self->stoptls;
		1354
		1355	if ($ssl eq "accept") {
		1356	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1357	Net::SSLeay::set_accept_state ($ssl);
		1358	} elsif ($ssl eq "connect") {
		1359	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1360	Net::SSLeay::set_connect_state ($ssl);
		1361	}
		1362
		1363	$self->{tls} = $ssl;
		1364
		1365	# basically, this is deep magic (because SSL_read should have the same issues)
		1366	# but the openssl maintainers basically said: "trust us, it just works".
		1367	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1368	# and mismaintained ssleay-module doesn't even offer them).
		1369	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1370	Net::SSLeay::CTX_set_mode ($self->{tls},
		1371	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1372	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1373
		1374	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1375	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1376
		1377	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1378
		1379	$self->{filter_w} = sub {
		1380	$_[0]{_tls_wbuf} .= ${$_[1]};
		1381	&_dotls;
		1382	};
		1383	$self->{filter_r} = sub {
		1384	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1385	&_dotls;
		1386	};
		1387	}
		1388
		1389	=item $handle->stoptls
		1390
		1391	Destroys the SSL connection, if any. Partial read or write data will be
		1392	lost.
		1393
		1394	=cut
		1395
		1396	sub stoptls {
		1397	my ($self) = @_;
		1398
		1399	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1400
		1401	delete $self->{_rbio};
		1402	delete $self->{_wbio};
		1403	delete $self->{_tls_wbuf};
		1404	delete $self->{filter_r};
		1405	delete $self->{filter_w};
		1406	}
		1407
		1408	sub DESTROY {
		1409	my $self = shift;
		1410
		1411	$self->stoptls;
		1412
		1413	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1414
		1415	if ($linger && length $self->{wbuf}) {
		1416	my $fh = delete $self->{fh};
		1417	my $wbuf = delete $self->{wbuf};
		1418
		1419	my @linger;
		1420
		1421	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1422	my $len = syswrite $fh, $wbuf, length $wbuf;
		1423
		1424	if ($len > 0) {
		1425	substr $wbuf, 0, $len, "";
		1426	} else {
		1427	@linger = (); # end
		1428	}
		1429	});
		1430	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1431	@linger = ();
		1432	});
		1433	}
		1434	}
		1435
		1436	=item AnyEvent::Handle::TLS_CTX
		1437
		1438	This function creates and returns the Net::SSLeay::CTX object used by
		1439	default for TLS mode.
		1440
		1441	The context is created like this:
		1442
		1443	Net::SSLeay::load_error_strings;
		1444	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1445	Net::SSLeay::randomize;
		1446
		1447	my $CTX = Net::SSLeay::CTX_new;
		1448
		1449	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1450
		1451	=cut
		1452
		1453	our $TLS_CTX;
		1454
		1455	sub TLS_CTX() {
		1456	$TLS_CTX || do {
		1457	require Net::SSLeay;
		1458
		1459	Net::SSLeay::load_error_strings ();
		1460	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1461	Net::SSLeay::randomize ();
		1462
		1463	$TLS_CTX = Net::SSLeay::CTX_new ();
		1464
		1465	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1466
		1467	$TLS_CTX
		1468	}
		1469	}
		1470
601	=back	1471	=back
602		1472
		1473	=head1 SUBCLASSING AnyEvent::Handle
		1474
		1475	In many cases, you might want to subclass AnyEvent::Handle.
		1476
		1477	To make this easier, a given version of AnyEvent::Handle uses these
		1478	conventions:
		1479
		1480	=over 4
		1481
		1482	=item * all constructor arguments become object members.
		1483
		1484	At least initially, when you pass a C<tls>-argument to the constructor it
		1485	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1486	mutated later on (for example C<tls> will hold the TLS connection object).
		1487
		1488	=item * other object member names are prefixed with an C<_>.
		1489
		1490	All object members not explicitly documented (internal use) are prefixed
		1491	with an underscore character, so the remaining non-C<_>-namespace is free
		1492	for use for subclasses.
		1493
		1494	=item * all members not documented here and not prefixed with an underscore
		1495	are free to use in subclasses.
		1496
		1497	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1498	member variables, but thats just life, at least it is documented.
		1499
		1500	=back
		1501
603	=head1 AUTHOR	1502	=head1 AUTHOR
604		1503
605	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1504	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
606		1505
607	=cut	1506	=cut

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