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Revision 1.15 by root, Sat May 17 21:34:15 2008 UTC vs.
Revision 1.87 by root, Thu Aug 21 20:52:39 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	no warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent ();	6	use AnyEvent ();
7	use AnyEvent::Util ();	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
8	use Scalar::Util ();	8	use Scalar::Util ();
9	use Carp ();	9	use Carp ();
10	use Fcntl ();	10	use Fcntl ();
11	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
12		12
13	=head1 NAME	13	=head1 NAME
14		14
15	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	This module is experimental.
18
19	=cut	17	=cut
20		18
21	our $VERSION = '0.04';	19	our $VERSION = 4.232;
22		20
23	=head1 SYNOPSIS	21	=head1 SYNOPSIS
24		22
25	use AnyEvent;	23	use AnyEvent;
26	use AnyEvent::Handle;	24	use AnyEvent::Handle;
27		25
28	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
29		27
30	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
31
32	#TODO
33
34	# or use the constructor to pass the callback:
35
36	my $ae_fh2 =
37	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
38	fh => \*STDIN,	30	fh => \*STDIN,
39	on_eof => sub {	31	on_eof => sub {
40	$cv->broadcast;	32	$cv->broadcast;
41	},	33	},
42	#TODO
43	);	34	);
44		35
45	$cv->wait;	36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
		41	my ($handle, $line) = @_;
		42	warn "read line <$line>\n";
		43	$cv->send;
		44	});
		45
		46	$cv->recv;
46		47
47	=head1 DESCRIPTION	48	=head1 DESCRIPTION
48		49
49	This module is a helper module to make it easier to do event-based I/O on	50	This module is a helper module to make it easier to do event-based I/O on
50	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
51	on sockets see L<AnyEvent::Util>.	52	on sockets see L<AnyEvent::Util>.
52		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
53	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
54	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
55	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
56		60
57	All callbacks will be invoked with the handle object as their first	61	All callbacks will be invoked with the handle object as their first
…		…
69		73
70	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
71		75
72	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
73		77
74	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
75	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
76		81
77	=item on_eof => $cb->($self) [MANDATORY]
78
79	Set the callback to be called on EOF.
80
81	=item on_error => $cb->($self)	82	=item on_eof => $cb->($handle)
82		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, $fatal)
		101
83	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
84	ocurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
85	or a read error.	104	connect or a read error.
86		105
87	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
88	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>).
89		116
90	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
91	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
92		119
93	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
94	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
95	die.	122	C<croak>.
96		123
97	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
98		125
99	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
100	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).
101		130
102	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 >>
103	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
104		133
105	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
106	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
107	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
108	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
109		138
110	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
111		140
112	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
113	(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).
114		143
115	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.
116		171
117	=item rbuf_max => <bytes>	172	=item rbuf_max => <bytes>
118		173
119	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>)
120	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
…		…
124	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
125	(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
126	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
127	isn't finished).	182	isn't finished).
128		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
129	=item read_size => <bytes>	208	=item read_size => <bytes>
130		209
131	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
132	on each [loop iteration). Default: C<4096>.	211	during each (loop iteration). Default: C<8192>.
133		212
134	=item low_water_mark => <bytes>	213	=item low_water_mark => <bytes>
135		214
136	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
137	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
138	considered empty.	217	considered empty.
139		218
		219	=item linger => <seconds>
		220
		221	If non-zero (default: C<3600>), then the destructor of the
		222	AnyEvent::Handle object will check wether there is still outstanding write
		223	data and will install a watcher that will write out this data. No errors
		224	will be reported (this mostly matches how the operating system treats
		225	outstanding data at socket close time).
		226
		227	This will not work for partial TLS data that could not yet been
		228	encoded. This data will be lost.
		229
		230	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		231
		232	When this parameter is given, it enables TLS (SSL) mode, that means
		233	AnyEvent will start a TLS handshake and will transparently encrypt/decrypt
		234	data.
		235
		236	TLS mode requires Net::SSLeay to be installed (it will be loaded
		237	automatically when you try to create a TLS handle).
		238
		239	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		240	C<accept>, and for the TLS client side of a connection, use C<connect>
		241	mode.
		242
		243	You can also provide your own TLS connection object, but you have
		244	to make sure that you call either C<Net::SSLeay::set_connect_state>
		245	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		246	AnyEvent::Handle.
		247
		248	See the C<starttls> method for when need to start TLS negotiation later.
		249
		250	=item tls_ctx => $ssl_ctx
		251
		252	Use the given Net::SSLeay::CTX object to create the new TLS connection
		253	(unless a connection object was specified directly). If this parameter is
		254	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		255
		256	=item json => JSON or JSON::XS object
		257
		258	This is the json coder object used by the C<json> read and write types.
		259
		260	If you don't supply it, then AnyEvent::Handle will create and use a
		261	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		262	texts.
		263
		264	Note that you are responsible to depend on the JSON module if you want to
		265	use this functionality, as AnyEvent does not have a dependency itself.
		266
		267	=item filter_r => $cb
		268
		269	=item filter_w => $cb
		270
		271	These exist, but are undocumented at this time. (They are used internally
		272	by the TLS code).
		273
140	=back	274	=back
141		275
142	=cut	276	=cut
143		277
144	sub new {	278	sub new {
…		…
148		282
149	$self->{fh} or Carp::croak "mandatory argument fh is missing";	283	$self->{fh} or Carp::croak "mandatory argument fh is missing";
150		284
151	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	285	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
152		286
153	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	287	if ($self->{tls}) {
		288	require Net::SSLeay;
		289	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		290	}
154		291
155	$self->on_error (delete $self->{on_error}) if $self->{on_error};	292	$self->{_activity} = AnyEvent->now;
		293	$self->_timeout;
		294
156	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	295	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
157	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	296	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
158		297
159	$self->start_read;	298	$self->start_read
		299	if $self->{on_read};
160		300
161	$self	301	$self
162	}	302	}
163		303
164	sub _shutdown {	304	sub _shutdown {
165	my ($self) = @_;	305	my ($self) = @_;
166		306
		307	delete $self->{_tw};
167	delete $self->{rw};	308	delete $self->{_rw};
168	delete $self->{ww};	309	delete $self->{_ww};
169	delete $self->{fh};	310	delete $self->{fh};
170	}
171		311
		312	$self->stoptls;
		313
		314	delete $self->{on_read};
		315	delete $self->{_queue};
		316	}
		317
172	sub error {	318	sub _error {
173	my ($self) = @_;	319	my ($self, $errno, $fatal) = @_;
174		320
175	{
176	local $!;
177	$self->_shutdown;	321	$self->_shutdown
178	}	322	if $fatal;
		323
		324	$! = $errno;
179		325
180	if ($self->{on_error}) {	326	if ($self->{on_error}) {
181	$self->{on_error}($self);	327	$self->{on_error}($self, $fatal);
182	} else {	328	} else {
183	die "AnyEvent::Handle uncaught fatal error: $!";	329	Carp::croak "AnyEvent::Handle uncaught error: $!";
184	}	330	}
185	}	331	}
186		332
187	=item $fh = $handle->fh	333	=item $fh = $handle->fh
188		334
189	This method returns the filehandle of the L<AnyEvent::Handle> object.	335	This method returns the file handle of the L<AnyEvent::Handle> object.
190		336
191	=cut	337	=cut
192		338
193	sub fh { $_[0]->{fh} }	339	sub fh { $_[0]{fh} }
194		340
195	=item $handle->on_error ($cb)	341	=item $handle->on_error ($cb)
196		342
197	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	343	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
198		344
…		…
210		356
211	sub on_eof {	357	sub on_eof {
212	$_[0]{on_eof} = $_[1];	358	$_[0]{on_eof} = $_[1];
213	}	359	}
214		360
		361	=item $handle->on_timeout ($cb)
		362
		363	Replace the current C<on_timeout> callback, or disables the callback
		364	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		365	argument.
		366
		367	=cut
		368
		369	sub on_timeout {
		370	$_[0]{on_timeout} = $_[1];
		371	}
		372
		373	=item $handle->autocork ($boolean)
		374
		375	Enables or disables the current autocork behaviour (see C<autocork>
		376	constructor argument).
		377
		378	=cut
		379
		380	=item $handle->no_delay ($boolean)
		381
		382	Enables or disables the C<no_delay> setting (see constructor argument of
		383	the same name for details).
		384
		385	=cut
		386
		387	sub no_delay {
		388	$_[0]{no_delay} = $_[1];
		389
		390	eval {
		391	local $SIG{__DIE__};
		392	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		393	};
		394	}
		395
		396	#############################################################################
		397
		398	=item $handle->timeout ($seconds)
		399
		400	Configures (or disables) the inactivity timeout.
		401
		402	=cut
		403
		404	sub timeout {
		405	my ($self, $timeout) = @_;
		406
		407	$self->{timeout} = $timeout;
		408	$self->_timeout;
		409	}
		410
		411	# reset the timeout watcher, as neccessary
		412	# also check for time-outs
		413	sub _timeout {
		414	my ($self) = @_;
		415
		416	if ($self->{timeout}) {
		417	my $NOW = AnyEvent->now;
		418
		419	# when would the timeout trigger?
		420	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		421
		422	# now or in the past already?
		423	if ($after <= 0) {
		424	$self->{_activity} = $NOW;
		425
		426	if ($self->{on_timeout}) {
		427	$self->{on_timeout}($self);
		428	} else {
		429	$self->_error (&Errno::ETIMEDOUT);
		430	}
		431
		432	# callback could have changed timeout value, optimise
		433	return unless $self->{timeout};
		434
		435	# calculate new after
		436	$after = $self->{timeout};
		437	}
		438
		439	Scalar::Util::weaken $self;
		440	return unless $self; # ->error could have destroyed $self
		441
		442	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		443	delete $self->{_tw};
		444	$self->_timeout;
		445	});
		446	} else {
		447	delete $self->{_tw};
		448	}
		449	}
		450
215	#############################################################################	451	#############################################################################
216		452
217	=back	453	=back
218		454
219	=head2 WRITE QUEUE	455	=head2 WRITE QUEUE
…		…
222	for reading.	458	for reading.
223		459
224	The write queue is very simple: you can add data to its end, and	460	The write queue is very simple: you can add data to its end, and
225	AnyEvent::Handle will automatically try to get rid of it for you.	461	AnyEvent::Handle will automatically try to get rid of it for you.
226		462
227	When data could be writtena nd the write buffer is shorter then the low	463	When data could be written and the write buffer is shorter then the low
228	water mark, the C<on_drain> callback will be invoked.	464	water mark, the C<on_drain> callback will be invoked.
229		465
230	=over 4	466	=over 4
231		467
232	=item $handle->on_drain ($cb)	468	=item $handle->on_drain ($cb)
…		…
251	want (only limited by the available memory), as C<AnyEvent::Handle>	487	want (only limited by the available memory), as C<AnyEvent::Handle>
252	buffers it independently of the kernel.	488	buffers it independently of the kernel.
253		489
254	=cut	490	=cut
255		491
256	sub push_write {	492	sub _drain_wbuf {
257	my ($self, $data) = @_;	493	my ($self) = @_;
258		494
259	$self->{wbuf} .= $data;	495	if (!$self->{_ww} && length $self->{wbuf}) {
260		496
261	unless ($self->{ww}) {
262	Scalar::Util::weaken $self;	497	Scalar::Util::weaken $self;
		498
263	my $cb = sub {	499	my $cb = sub {
264	my $len = syswrite $self->{fh}, $self->{wbuf};	500	my $len = syswrite $self->{fh}, $self->{wbuf};
265		501
266	if ($len > 0) {	502	if ($len >= 0) {
267	substr $self->{wbuf}, 0, $len, "";	503	substr $self->{wbuf}, 0, $len, "";
268		504
		505	$self->{_activity} = AnyEvent->now;
269		506
270	$self->{on_drain}($self)	507	$self->{on_drain}($self)
271	if $self->{low_water_mark} >= length $self->{wbuf}	508	if $self->{low_water_mark} >= length $self->{wbuf}
272	&& $self->{on_drain};	509	&& $self->{on_drain};
273		510
274	delete $self->{ww} unless length $self->{wbuf};	511	delete $self->{_ww} unless length $self->{wbuf};
275	} elsif ($! != EAGAIN && $! != EINTR) {	512	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
276	$self->error;	513	$self->_error ($!, 1);
277	}	514	}
278	};	515	};
279		516
		517	# try to write data immediately
		518	$cb->() unless $self->{autocork};
		519
		520	# if still data left in wbuf, we need to poll
280	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	521	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
281		522	if length $self->{wbuf};
282	$cb->($self);
283	};	523	};
284	}	524	}
		525
		526	our %WH;
		527
		528	sub register_write_type($$) {
		529	$WH{$_[0]} = $_[1];
		530	}
		531
		532	sub push_write {
		533	my $self = shift;
		534
		535	if (@_ > 1) {
		536	my $type = shift;
		537
		538	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		539	->($self, @_);
		540	}
		541
		542	if ($self->{filter_w}) {
		543	$self->{filter_w}($self, \$_[0]);
		544	} else {
		545	$self->{wbuf} .= $_[0];
		546	$self->_drain_wbuf;
		547	}
		548	}
		549
		550	=item $handle->push_write (type => @args)
		551
		552	Instead of formatting your data yourself, you can also let this module do
		553	the job by specifying a type and type-specific arguments.
		554
		555	Predefined types are (if you have ideas for additional types, feel free to
		556	drop by and tell us):
		557
		558	=over 4
		559
		560	=item netstring => $string
		561
		562	Formats the given value as netstring
		563	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		564
		565	=cut
		566
		567	register_write_type netstring => sub {
		568	my ($self, $string) = @_;
		569
		570	sprintf "%d:%s,", (length $string), $string
		571	};
		572
		573	=item packstring => $format, $data
		574
		575	An octet string prefixed with an encoded length. The encoding C<$format>
		576	uses the same format as a Perl C<pack> format, but must specify a single
		577	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		578	optional C<!>, C<< < >> or C<< > >> modifier).
		579
		580	=cut
		581
		582	register_write_type packstring => sub {
		583	my ($self, $format, $string) = @_;
		584
		585	pack "$format/a*", $string
		586	};
		587
		588	=item json => $array_or_hashref
		589
		590	Encodes the given hash or array reference into a JSON object. Unless you
		591	provide your own JSON object, this means it will be encoded to JSON text
		592	in UTF-8.
		593
		594	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		595	one end of a handle and read them at the other end without using any
		596	additional framing.
		597
		598	The generated JSON text is guaranteed not to contain any newlines: While
		599	this module doesn't need delimiters after or between JSON texts to be
		600	able to read them, many other languages depend on that.
		601
		602	A simple RPC protocol that interoperates easily with others is to send
		603	JSON arrays (or objects, although arrays are usually the better choice as
		604	they mimic how function argument passing works) and a newline after each
		605	JSON text:
		606
		607	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		608	$handle->push_write ("\012");
		609
		610	An AnyEvent::Handle receiver would simply use the C<json> read type and
		611	rely on the fact that the newline will be skipped as leading whitespace:
		612
		613	$handle->push_read (json => sub { my $array = $_[1]; ... });
		614
		615	Other languages could read single lines terminated by a newline and pass
		616	this line into their JSON decoder of choice.
		617
		618	=cut
		619
		620	register_write_type json => sub {
		621	my ($self, $ref) = @_;
		622
		623	require JSON;
		624
		625	$self->{json} ? $self->{json}->encode ($ref)
		626	: JSON::encode_json ($ref)
		627	};
		628
		629	=item storable => $reference
		630
		631	Freezes the given reference using L<Storable> and writes it to the
		632	handle. Uses the C<nfreeze> format.
		633
		634	=cut
		635
		636	register_write_type storable => sub {
		637	my ($self, $ref) = @_;
		638
		639	require Storable;
		640
		641	pack "w/a*", Storable::nfreeze ($ref)
		642	};
		643
		644	=back
		645
		646	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		647
		648	This function (not method) lets you add your own types to C<push_write>.
		649	Whenever the given C<type> is used, C<push_write> will invoke the code
		650	reference with the handle object and the remaining arguments.
		651
		652	The code reference is supposed to return a single octet string that will
		653	be appended to the write buffer.
		654
		655	Note that this is a function, and all types registered this way will be
		656	global, so try to use unique names.
		657
		658	=cut
285		659
286	#############################################################################	660	#############################################################################
287		661
288	=back	662	=back
289		663
…		…
296	ways, the "simple" way, using only C<on_read> and the "complex" way, using	670	ways, the "simple" way, using only C<on_read> and the "complex" way, using
297	a queue.	671	a queue.
298		672
299	In the simple case, you just install an C<on_read> callback and whenever	673	In the simple case, you just install an C<on_read> callback and whenever
300	new data arrives, it will be called. You can then remove some data (if	674	new data arrives, it will be called. You can then remove some data (if
301	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	675	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
302	or not.	676	leave the data there if you want to accumulate more (e.g. when only a
		677	partial message has been received so far).
303		678
304	In the more complex case, you want to queue multiple callbacks. In this	679	In the more complex case, you want to queue multiple callbacks. In this
305	case, AnyEvent::Handle will call the first queued callback each time new	680	case, AnyEvent::Handle will call the first queued callback each time new
306	data arrives and removes it when it has done its job (see C<push_read>,	681	data arrives (also the first time it is queued) and removes it when it has
307	below).	682	done its job (see C<push_read>, below).
308		683
309	This way you can, for example, push three line-reads, followed by reading	684	This way you can, for example, push three line-reads, followed by reading
310	a chunk of data, and AnyEvent::Handle will execute them in order.	685	a chunk of data, and AnyEvent::Handle will execute them in order.
311		686
312	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	687	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
313	the specified number of bytes which give an XML datagram.	688	the specified number of bytes which give an XML datagram.
314		689
315	# in the default state, expect some header bytes	690	# in the default state, expect some header bytes
316	$handle->on_read (sub {	691	$handle->on_read (sub {
317	# some data is here, now queue the length-header-read (4 octets)	692	# some data is here, now queue the length-header-read (4 octets)
318	shift->unshift_read_chunk (4, sub {	693	shift->unshift_read (chunk => 4, sub {
319	# header arrived, decode	694	# header arrived, decode
320	my $len = unpack "N", $_[1];	695	my $len = unpack "N", $_[1];
321		696
322	# now read the payload	697	# now read the payload
323	shift->unshift_read_chunk ($len, sub {	698	shift->unshift_read (chunk => $len, sub {
324	my $xml = $_[1];	699	my $xml = $_[1];
325	# handle xml	700	# handle xml
326	});	701	});
327	});	702	});
328	});	703	});
329		704
330	Example 2: Implement a client for a protocol that replies either with	705	Example 2: Implement a client for a protocol that replies either with "OK"
331	"OK" and another line or "ERROR" for one request, and 64 bytes for the	706	and another line or "ERROR" for the first request that is sent, and 64
332	second request. Due tot he availability of a full queue, we can just	707	bytes for the second request. Due to the availability of a queue, we can
333	pipeline sending both requests and manipulate the queue as necessary in	708	just pipeline sending both requests and manipulate the queue as necessary
334	the callbacks:	709	in the callbacks.
335		710
336	# request one	711	When the first callback is called and sees an "OK" response, it will
		712	C<unshift> another line-read. This line-read will be queued I<before> the
		713	64-byte chunk callback.
		714
		715	# request one, returns either "OK + extra line" or "ERROR"
337	$handle->push_write ("request 1\015\012");	716	$handle->push_write ("request 1\015\012");
338		717
339	# we expect "ERROR" or "OK" as response, so push a line read	718	# we expect "ERROR" or "OK" as response, so push a line read
340	$handle->push_read_line (sub {	719	$handle->push_read (line => sub {
341	# if we got an "OK", we have to _prepend_ another line,	720	# if we got an "OK", we have to _prepend_ another line,
342	# so it will be read before the second request reads its 64 bytes	721	# so it will be read before the second request reads its 64 bytes
343	# which are already in the queue when this callback is called	722	# which are already in the queue when this callback is called
344	# we don't do this in case we got an error	723	# we don't do this in case we got an error
345	if ($_[1] eq "OK") {	724	if ($_[1] eq "OK") {
346	$_[0]->unshift_read_line (sub {	725	$_[0]->unshift_read (line => sub {
347	my $response = $_[1];	726	my $response = $_[1];
348	...	727	...
349	});	728	});
350	}	729	}
351	});	730	});
352		731
353	# request two	732	# request two, simply returns 64 octets
354	$handle->push_write ("request 2\015\012");	733	$handle->push_write ("request 2\015\012");
355		734
356	# simply read 64 bytes, always	735	# simply read 64 bytes, always
357	$handle->push_read_chunk (64, sub {	736	$handle->push_read (chunk => 64, sub {
358	my $response = $_[1];	737	my $response = $_[1];
359	...	738	...
360	});	739	});
361		740
362	=over 4	741	=over 4
…		…
364	=cut	743	=cut
365		744
366	sub _drain_rbuf {	745	sub _drain_rbuf {
367	my ($self) = @_;	746	my ($self) = @_;
368		747
369	return if $self->{in_drain};
370	local $self->{in_drain} = 1;	748	local $self->{_in_drain} = 1;
371		749
		750	if (
		751	defined $self->{rbuf_max}
		752	&& $self->{rbuf_max} < length $self->{rbuf}
		753	) {
		754	$self->_error (&Errno::ENOSPC, 1), return;
		755	}
		756
		757	while () {
372	while (my $len = length $self->{rbuf}) {	758	my $len = length $self->{rbuf};
373	no strict 'refs';	759
374	if (my $cb = shift @{ $self->{queue} }) {	760	if (my $cb = shift @{ $self->{_queue} }) {
375	if (!$cb->($self)) {	761	unless ($cb->($self)) {
376	if ($self->{eof}) {	762	if ($self->{_eof}) {
377	# no progress can be made (not enough data and no data forthcoming)	763	# no progress can be made (not enough data and no data forthcoming)
378	$! = &Errno::EPIPE; return $self->error;	764	$self->_error (&Errno::EPIPE, 1), return;
379	}	765	}
380		766
381	unshift @{ $self->{queue} }, $cb;	767	unshift @{ $self->{_queue} }, $cb;
382	return;	768	last;
383	}	769	}
384	} elsif ($self->{on_read}) {	770	} elsif ($self->{on_read}) {
		771	last unless $len;
		772
385	$self->{on_read}($self);	773	$self->{on_read}($self);
386		774
387	if (	775	if (
388	$self->{eof} # if no further data will arrive
389	&& $len == length $self->{rbuf} # and no data has been consumed	776	$len == length $self->{rbuf} # if no data has been consumed
390	&& !@{ $self->{queue} } # and the queue is still empty	777	&& !@{ $self->{_queue} } # and the queue is still empty
391	&& $self->{on_read} # and we still want to read data	778	&& $self->{on_read} # but we still have on_read
392	) {	779	) {
		780	# no further data will arrive
393	# then no progress can be made	781	# so no progress can be made
394	$! = &Errno::EPIPE; return $self->error;	782	$self->_error (&Errno::EPIPE, 1), return
		783	if $self->{_eof};
		784
		785	last; # more data might arrive
395	}	786	}
396	} else {	787	} else {
397	# read side becomes idle	788	# read side becomes idle
398	delete $self->{rw};	789	delete $self->{_rw};
399	return;	790	last;
400	}	791	}
401	}	792	}
402		793
403	if ($self->{eof}) {	794	if ($self->{_eof}) {
404	$self->_shutdown;	795	if ($self->{on_eof}) {
405	$self->{on_eof}($self);	796	$self->{on_eof}($self)
		797	} else {
		798	$self->_error (0, 1);
		799	}
		800	}
		801
		802	# may need to restart read watcher
		803	unless ($self->{_rw}) {
		804	$self->start_read
		805	if $self->{on_read} || @{ $self->{_queue} };
406	}	806	}
407	}	807	}
408		808
409	=item $handle->on_read ($cb)	809	=item $handle->on_read ($cb)
410		810
…		…
416		816
417	sub on_read {	817	sub on_read {
418	my ($self, $cb) = @_;	818	my ($self, $cb) = @_;
419		819
420	$self->{on_read} = $cb;	820	$self->{on_read} = $cb;
		821	$self->_drain_rbuf if $cb && !$self->{_in_drain};
421	}	822	}
422		823
423	=item $handle->rbuf	824	=item $handle->rbuf
424		825
425	Returns the read buffer (as a modifiable lvalue).	826	Returns the read buffer (as a modifiable lvalue).
…		…
444	Append the given callback to the end of the queue (C<push_read>) or	845	Append the given callback to the end of the queue (C<push_read>) or
445	prepend it (C<unshift_read>).	846	prepend it (C<unshift_read>).
446		847
447	The callback is called each time some additional read data arrives.	848	The callback is called each time some additional read data arrives.
448		849
449	It must check wether enough data is in the read buffer already.	850	It must check whether enough data is in the read buffer already.
450		851
451	If not enough data is available, it must return the empty list or a false	852	If not enough data is available, it must return the empty list or a false
452	value, in which case it will be called repeatedly until enough data is	853	value, in which case it will be called repeatedly until enough data is
453	available (or an error condition is detected).	854	available (or an error condition is detected).
454		855
…		…
456	interested in (which can be none at all) and return a true value. After returning	857	interested in (which can be none at all) and return a true value. After returning
457	true, it will be removed from the queue.	858	true, it will be removed from the queue.
458		859
459	=cut	860	=cut
460		861
		862	our %RH;
		863
		864	sub register_read_type($$) {
		865	$RH{$_[0]} = $_[1];
		866	}
		867
461	sub push_read {	868	sub push_read {
462	my ($self, $cb) = @_;	869	my $self = shift;
		870	my $cb = pop;
463		871
		872	if (@_) {
		873	my $type = shift;
		874
		875	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		876	->($self, $cb, @_);
		877	}
		878
464	push @{ $self->{queue} }, $cb;	879	push @{ $self->{_queue} }, $cb;
465	$self->_drain_rbuf;	880	$self->_drain_rbuf unless $self->{_in_drain};
466	}	881	}
467		882
468	sub unshift_read {	883	sub unshift_read {
469	my ($self, $cb) = @_;	884	my $self = shift;
		885	my $cb = pop;
470		886
		887	if (@_) {
		888	my $type = shift;
		889
		890	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		891	->($self, $cb, @_);
		892	}
		893
		894
471	push @{ $self->{queue} }, $cb;	895	unshift @{ $self->{_queue} }, $cb;
472	$self->_drain_rbuf;	896	$self->_drain_rbuf unless $self->{_in_drain};
473	}	897	}
474		898
475	=item $handle->push_read_chunk ($len, $cb->($self, $data))	899	=item $handle->push_read (type => @args, $cb)
476		900
477	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	901	=item $handle->unshift_read (type => @args, $cb)
478		902
479	Append the given callback to the end of the queue (C<push_read_chunk>) or	903	Instead of providing a callback that parses the data itself you can chose
480	prepend it (C<unshift_read_chunk>).	904	between a number of predefined parsing formats, for chunks of data, lines
		905	etc.
481		906
482	The callback will be called only once C<$len> bytes have been read, and	907	Predefined types are (if you have ideas for additional types, feel free to
483	these C<$len> bytes will be passed to the callback.	908	drop by and tell us):
484		909
485	=cut	910	=over 4
486		911
487	sub _read_chunk($$) {	912	=item chunk => $octets, $cb->($handle, $data)
		913
		914	Invoke the callback only once C<$octets> bytes have been read. Pass the
		915	data read to the callback. The callback will never be called with less
		916	data.
		917
		918	Example: read 2 bytes.
		919
		920	$handle->push_read (chunk => 2, sub {
		921	warn "yay ", unpack "H*", $_[1];
		922	});
		923
		924	=cut
		925
		926	register_read_type chunk => sub {
488	my ($self, $len, $cb) = @_;	927	my ($self, $cb, $len) = @_;
489		928
490	sub {	929	sub {
491	$len <= length $_[0]{rbuf} or return;	930	$len <= length $_[0]{rbuf} or return;
492	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	931	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
493	1	932	1
494	}	933	}
495	}	934	};
496		935
497	sub push_read_chunk {	936	=item line => [$eol, ]$cb->($handle, $line, $eol)
498	$_[0]->push_read (&_read_chunk);
499	}
500
501
502	sub unshift_read_chunk {
503	$_[0]->unshift_read (&_read_chunk);
504	}
505
506	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
507
508	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
509
510	Append the given callback to the end of the queue (C<push_read_line>) or
511	prepend it (C<unshift_read_line>).
512		937
513	The callback will be called only once a full line (including the end of	938	The callback will be called only once a full line (including the end of
514	line marker, C<$eol>) has been read. This line (excluding the end of line	939	line marker, C<$eol>) has been read. This line (excluding the end of line
515	marker) will be passed to the callback as second argument (C<$line>), and	940	marker) will be passed to the callback as second argument (C<$line>), and
516	the end of line marker as the third argument (C<$eol>).	941	the end of line marker as the third argument (C<$eol>).
…		…
527	Partial lines at the end of the stream will never be returned, as they are	952	Partial lines at the end of the stream will never be returned, as they are
528	not marked by the end of line marker.	953	not marked by the end of line marker.
529		954
530	=cut	955	=cut
531		956
532	sub _read_line($$) {	957	register_read_type line => sub {
533	my $self = shift;	958	my ($self, $cb, $eol) = @_;
534	my $cb = pop;
535	my $eol = @_ ? shift : qr|(\015?\012)|;
536	my $pos;
537		959
		960	if (@_ < 3) {
		961	# this is more than twice as fast as the generic code below
		962	sub {
		963	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		964
		965	$cb->($_[0], $1, $2);
		966	1
		967	}
		968	} else {
538	$eol = quotemeta $eol unless ref $eol;	969	$eol = quotemeta $eol unless ref $eol;
539	$eol = qr|^(.*?)($eol)|s;	970	$eol = qr|^(.*?)($eol)|s;
		971
		972	sub {
		973	$_[0]{rbuf} =~ s/$eol// or return;
		974
		975	$cb->($_[0], $1, $2);
		976	1
		977	}
		978	}
		979	};
		980
		981	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		982
		983	Makes a regex match against the regex object C<$accept> and returns
		984	everything up to and including the match.
		985
		986	Example: read a single line terminated by '\n'.
		987
		988	$handle->push_read (regex => qr<\n>, sub { ... });
		989
		990	If C<$reject> is given and not undef, then it determines when the data is
		991	to be rejected: it is matched against the data when the C<$accept> regex
		992	does not match and generates an C<EBADMSG> error when it matches. This is
		993	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		994	receive buffer overflow).
		995
		996	Example: expect a single decimal number followed by whitespace, reject
		997	anything else (not the use of an anchor).
		998
		999	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1000
		1001	If C<$skip> is given and not C<undef>, then it will be matched against
		1002	the receive buffer when neither C<$accept> nor C<$reject> match,
		1003	and everything preceding and including the match will be accepted
		1004	unconditionally. This is useful to skip large amounts of data that you
		1005	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1006	have to start matching from the beginning. This is purely an optimisation
		1007	and is usually worth only when you expect more than a few kilobytes.
		1008
		1009	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1010	expect the header to be very large (it isn't in practise, but...), we use
		1011	a skip regex to skip initial portions. The skip regex is tricky in that
		1012	it only accepts something not ending in either \015 or \012, as these are
		1013	required for the accept regex.
		1014
		1015	$handle->push_read (regex =>
		1016	qr<\015\012\015\012>,
		1017	undef, # no reject
		1018	qr<^.*[^\015\012]>,
		1019	sub { ... });
		1020
		1021	=cut
		1022
		1023	register_read_type regex => sub {
		1024	my ($self, $cb, $accept, $reject, $skip) = @_;
		1025
		1026	my $data;
		1027	my $rbuf = \$self->{rbuf};
540		1028
541	sub {	1029	sub {
542	$_[0]{rbuf} =~ s/$eol// or return;	1030	# accept
		1031	if ($$rbuf =~ $accept) {
		1032	$data .= substr $$rbuf, 0, $+[0], "";
		1033	$cb->($self, $data);
		1034	return 1;
		1035	}
		1036
		1037	# reject
		1038	if ($reject && $$rbuf =~ $reject) {
		1039	$self->_error (&Errno::EBADMSG);
		1040	}
543		1041
544	$cb->($_[0], $1, $2);	1042	# skip
		1043	if ($skip && $$rbuf =~ $skip) {
		1044	$data .= substr $$rbuf, 0, $+[0], "";
		1045	}
		1046
		1047	()
		1048	}
		1049	};
		1050
		1051	=item netstring => $cb->($handle, $string)
		1052
		1053	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1054
		1055	Throws an error with C<$!> set to EBADMSG on format violations.
		1056
		1057	=cut
		1058
		1059	register_read_type netstring => sub {
		1060	my ($self, $cb) = @_;
		1061
		1062	sub {
		1063	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1064	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1065	$self->_error (&Errno::EBADMSG);
		1066	}
		1067	return;
		1068	}
		1069
		1070	my $len = $1;
		1071
		1072	$self->unshift_read (chunk => $len, sub {
		1073	my $string = $_[1];
		1074	$_[0]->unshift_read (chunk => 1, sub {
		1075	if ($_[1] eq ",") {
		1076	$cb->($_[0], $string);
		1077	} else {
		1078	$self->_error (&Errno::EBADMSG);
		1079	}
		1080	});
		1081	});
		1082
545	1	1083	1
546	}	1084	}
547	}	1085	};
548		1086
549	sub push_read_line {	1087	=item packstring => $format, $cb->($handle, $string)
550	$_[0]->push_read (&_read_line);
551	}
552		1088
553	sub unshift_read_line {	1089	An octet string prefixed with an encoded length. The encoding C<$format>
554	$_[0]->unshift_read (&_read_line);	1090	uses the same format as a Perl C<pack> format, but must specify a single
555	}	1091	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1092	optional C<!>, C<< < >> or C<< > >> modifier).
		1093
		1094	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1095
		1096	Example: read a block of data prefixed by its length in BER-encoded
		1097	format (very efficient).
		1098
		1099	$handle->push_read (packstring => "w", sub {
		1100	my ($handle, $data) = @_;
		1101	});
		1102
		1103	=cut
		1104
		1105	register_read_type packstring => sub {
		1106	my ($self, $cb, $format) = @_;
		1107
		1108	sub {
		1109	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1110	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1111	or return;
		1112
		1113	$format = length pack $format, $len;
		1114
		1115	# bypass unshift if we already have the remaining chunk
		1116	if ($format + $len <= length $_[0]{rbuf}) {
		1117	my $data = substr $_[0]{rbuf}, $format, $len;
		1118	substr $_[0]{rbuf}, 0, $format + $len, "";
		1119	$cb->($_[0], $data);
		1120	} else {
		1121	# remove prefix
		1122	substr $_[0]{rbuf}, 0, $format, "";
		1123
		1124	# read remaining chunk
		1125	$_[0]->unshift_read (chunk => $len, $cb);
		1126	}
		1127
		1128	1
		1129	}
		1130	};
		1131
		1132	=item json => $cb->($handle, $hash_or_arrayref)
		1133
		1134	Reads a JSON object or array, decodes it and passes it to the callback.
		1135
		1136	If a C<json> object was passed to the constructor, then that will be used
		1137	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1138
		1139	This read type uses the incremental parser available with JSON version
		1140	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1141	dependency on your own: this module will load the JSON module, but
		1142	AnyEvent does not depend on it itself.
		1143
		1144	Since JSON texts are fully self-delimiting, the C<json> read and write
		1145	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1146	the C<json> write type description, above, for an actual example.
		1147
		1148	=cut
		1149
		1150	register_read_type json => sub {
		1151	my ($self, $cb) = @_;
		1152
		1153	require JSON;
		1154
		1155	my $data;
		1156	my $rbuf = \$self->{rbuf};
		1157
		1158	my $json = $self->{json} ||= JSON->new->utf8;
		1159
		1160	sub {
		1161	my $ref = $json->incr_parse ($self->{rbuf});
		1162
		1163	if ($ref) {
		1164	$self->{rbuf} = $json->incr_text;
		1165	$json->incr_text = "";
		1166	$cb->($self, $ref);
		1167
		1168	1
		1169	} else {
		1170	$self->{rbuf} = "";
		1171	()
		1172	}
		1173	}
		1174	};
		1175
		1176	=item storable => $cb->($handle, $ref)
		1177
		1178	Deserialises a L<Storable> frozen representation as written by the
		1179	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1180	data).
		1181
		1182	Raises C<EBADMSG> error if the data could not be decoded.
		1183
		1184	=cut
		1185
		1186	register_read_type storable => sub {
		1187	my ($self, $cb) = @_;
		1188
		1189	require Storable;
		1190
		1191	sub {
		1192	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1193	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1194	or return;
		1195
		1196	my $format = length pack "w", $len;
		1197
		1198	# bypass unshift if we already have the remaining chunk
		1199	if ($format + $len <= length $_[0]{rbuf}) {
		1200	my $data = substr $_[0]{rbuf}, $format, $len;
		1201	substr $_[0]{rbuf}, 0, $format + $len, "";
		1202	$cb->($_[0], Storable::thaw ($data));
		1203	} else {
		1204	# remove prefix
		1205	substr $_[0]{rbuf}, 0, $format, "";
		1206
		1207	# read remaining chunk
		1208	$_[0]->unshift_read (chunk => $len, sub {
		1209	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1210	$cb->($_[0], $ref);
		1211	} else {
		1212	$self->_error (&Errno::EBADMSG);
		1213	}
		1214	});
		1215	}
		1216
		1217	1
		1218	}
		1219	};
		1220
		1221	=back
		1222
		1223	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1224
		1225	This function (not method) lets you add your own types to C<push_read>.
		1226
		1227	Whenever the given C<type> is used, C<push_read> will invoke the code
		1228	reference with the handle object, the callback and the remaining
		1229	arguments.
		1230
		1231	The code reference is supposed to return a callback (usually a closure)
		1232	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1233
		1234	It should invoke the passed callback when it is done reading (remember to
		1235	pass C<$handle> as first argument as all other callbacks do that).
		1236
		1237	Note that this is a function, and all types registered this way will be
		1238	global, so try to use unique names.
		1239
		1240	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1241	search for C<register_read_type>)).
556		1242
557	=item $handle->stop_read	1243	=item $handle->stop_read
558		1244
559	=item $handle->start_read	1245	=item $handle->start_read
560		1246
561	In rare cases you actually do not want to read anything form the	1247	In rare cases you actually do not want to read anything from the
562	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1248	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
563	any queued callbacks will be executed then. To start readign again, call	1249	any queued callbacks will be executed then. To start reading again, call
564	C<start_read>.	1250	C<start_read>.
		1251
		1252	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1253	you change the C<on_read> callback or push/unshift a read callback, and it
		1254	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1255	there are any read requests in the queue.
565		1256
566	=cut	1257	=cut
567		1258
568	sub stop_read {	1259	sub stop_read {
569	my ($self) = @_;	1260	my ($self) = @_;
570		1261
571	delete $self->{rw};	1262	delete $self->{_rw};
572	}	1263	}
573		1264
574	sub start_read {	1265	sub start_read {
575	my ($self) = @_;	1266	my ($self) = @_;
576		1267
577	unless ($self->{rw} || $self->{eof}) {	1268	unless ($self->{_rw} || $self->{_eof}) {
578	Scalar::Util::weaken $self;	1269	Scalar::Util::weaken $self;
579		1270
580	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1271	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1272	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
581	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1273	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
582		1274
583	if ($len > 0) {	1275	if ($len > 0) {
584	if (defined $self->{rbuf_max}) {	1276	$self->{_activity} = AnyEvent->now;
585	if ($self->{rbuf_max} < length $self->{rbuf}) {	1277
586	$! = &Errno::ENOSPC; return $self->error;	1278	$self->{filter_r}
587	}	1279	? $self->{filter_r}($self, $rbuf)
588	}	1280	: $self->{_in_drain} || $self->_drain_rbuf;
589		1281
590	} elsif (defined $len) {	1282	} elsif (defined $len) {
591	$self->{eof} = 1;
592	delete $self->{rw};	1283	delete $self->{_rw};
		1284	$self->{_eof} = 1;
		1285	$self->_drain_rbuf unless $self->{_in_drain};
593		1286
594	} elsif ($! != EAGAIN && $! != EINTR) {	1287	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
595	return $self->error;	1288	return $self->_error ($!, 1);
596	}	1289	}
597
598	$self->_drain_rbuf;
599	});	1290	});
600	}	1291	}
601	}	1292	}
602		1293
		1294	sub _dotls {
		1295	my ($self) = @_;
		1296
		1297	my $buf;
		1298
		1299	if (length $self->{_tls_wbuf}) {
		1300	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1301	substr $self->{_tls_wbuf}, 0, $len, "";
		1302	}
		1303	}
		1304
		1305	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1306	$self->{wbuf} .= $buf;
		1307	$self->_drain_wbuf;
		1308	}
		1309
		1310	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1311	if (length $buf) {
		1312	$self->{rbuf} .= $buf;
		1313	$self->_drain_rbuf unless $self->{_in_drain};
		1314	} else {
		1315	# let's treat SSL-eof as we treat normal EOF
		1316	$self->{_eof} = 1;
		1317	$self->_shutdown;
		1318	return;
		1319	}
		1320	}
		1321
		1322	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1323
		1324	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1325	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1326	return $self->_error ($!, 1);
		1327	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1328	return $self->_error (&Errno::EIO, 1);
		1329	}
		1330
		1331	# all others are fine for our purposes
		1332	}
		1333	}
		1334
		1335	=item $handle->starttls ($tls[, $tls_ctx])
		1336
		1337	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1338	object is created, you can also do that at a later time by calling
		1339	C<starttls>.
		1340
		1341	The first argument is the same as the C<tls> constructor argument (either
		1342	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1343
		1344	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1345	used when AnyEvent::Handle has to create its own TLS connection object.
		1346
		1347	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1348	call and can be used or changed to your liking. Note that the handshake
		1349	might have already started when this function returns.
		1350
		1351	=cut
		1352
		1353	sub starttls {
		1354	my ($self, $ssl, $ctx) = @_;
		1355
		1356	$self->stoptls;
		1357
		1358	if ($ssl eq "accept") {
		1359	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1360	Net::SSLeay::set_accept_state ($ssl);
		1361	} elsif ($ssl eq "connect") {
		1362	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1363	Net::SSLeay::set_connect_state ($ssl);
		1364	}
		1365
		1366	$self->{tls} = $ssl;
		1367
		1368	# basically, this is deep magic (because SSL_read should have the same issues)
		1369	# but the openssl maintainers basically said: "trust us, it just works".
		1370	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1371	# and mismaintained ssleay-module doesn't even offer them).
		1372	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1373	#
		1374	# in short: this is a mess.
		1375	#
		1376	# note that we do not try to kepe the length constant between writes as we are required to do.
		1377	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1378	# and we drive openssl fully in blocking mode here.
		1379	Net::SSLeay::CTX_set_mode ($self->{tls},
		1380	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1381	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1382
		1383	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1384	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1385
		1386	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1387
		1388	$self->{filter_w} = sub {
		1389	$_[0]{_tls_wbuf} .= ${$_[1]};
		1390	&_dotls;
		1391	};
		1392	$self->{filter_r} = sub {
		1393	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1394	&_dotls;
		1395	};
		1396	}
		1397
		1398	=item $handle->stoptls
		1399
		1400	Destroys the SSL connection, if any. Partial read or write data will be
		1401	lost.
		1402
		1403	=cut
		1404
		1405	sub stoptls {
		1406	my ($self) = @_;
		1407
		1408	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1409
		1410	delete $self->{_rbio};
		1411	delete $self->{_wbio};
		1412	delete $self->{_tls_wbuf};
		1413	delete $self->{filter_r};
		1414	delete $self->{filter_w};
		1415	}
		1416
		1417	sub DESTROY {
		1418	my $self = shift;
		1419
		1420	$self->stoptls;
		1421
		1422	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1423
		1424	if ($linger && length $self->{wbuf}) {
		1425	my $fh = delete $self->{fh};
		1426	my $wbuf = delete $self->{wbuf};
		1427
		1428	my @linger;
		1429
		1430	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1431	my $len = syswrite $fh, $wbuf, length $wbuf;
		1432
		1433	if ($len > 0) {
		1434	substr $wbuf, 0, $len, "";
		1435	} else {
		1436	@linger = (); # end
		1437	}
		1438	});
		1439	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1440	@linger = ();
		1441	});
		1442	}
		1443	}
		1444
		1445	=item AnyEvent::Handle::TLS_CTX
		1446
		1447	This function creates and returns the Net::SSLeay::CTX object used by
		1448	default for TLS mode.
		1449
		1450	The context is created like this:
		1451
		1452	Net::SSLeay::load_error_strings;
		1453	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1454	Net::SSLeay::randomize;
		1455
		1456	my $CTX = Net::SSLeay::CTX_new;
		1457
		1458	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1459
		1460	=cut
		1461
		1462	our $TLS_CTX;
		1463
		1464	sub TLS_CTX() {
		1465	$TLS_CTX || do {
		1466	require Net::SSLeay;
		1467
		1468	Net::SSLeay::load_error_strings ();
		1469	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1470	Net::SSLeay::randomize ();
		1471
		1472	$TLS_CTX = Net::SSLeay::CTX_new ();
		1473
		1474	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1475
		1476	$TLS_CTX
		1477	}
		1478	}
		1479
603	=back	1480	=back
604		1481
		1482	=head1 SUBCLASSING AnyEvent::Handle
		1483
		1484	In many cases, you might want to subclass AnyEvent::Handle.
		1485
		1486	To make this easier, a given version of AnyEvent::Handle uses these
		1487	conventions:
		1488
		1489	=over 4
		1490
		1491	=item * all constructor arguments become object members.
		1492
		1493	At least initially, when you pass a C<tls>-argument to the constructor it
		1494	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1495	mutated later on (for example C<tls> will hold the TLS connection object).
		1496
		1497	=item * other object member names are prefixed with an C<_>.
		1498
		1499	All object members not explicitly documented (internal use) are prefixed
		1500	with an underscore character, so the remaining non-C<_>-namespace is free
		1501	for use for subclasses.
		1502
		1503	=item * all members not documented here and not prefixed with an underscore
		1504	are free to use in subclasses.
		1505
		1506	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1507	member variables, but thats just life, at least it is documented.
		1508
		1509	=back
		1510
605	=head1 AUTHOR	1511	=head1 AUTHOR
606		1512
607	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1513	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
608		1514
609	=cut	1515	=cut

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