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Revision 1.15 by root, Sat May 17 21:34:15 2008 UTC vs.
Revision 1.92 by root, Wed Oct 1 08:52:06 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 = 4.3;
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	$cv->recv;
46		47
47	=head1 DESCRIPTION	48	=head1 DESCRIPTION
48		49
49	This module is a helper module to make it easier to do event-based I/O on	50	This module is a helper module to make it easier to do event-based I/O on
50	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
51	on sockets see L<AnyEvent::Util>.	52	on sockets see L<AnyEvent::Util>.
52		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
53	In the following, when the documentation refers to of "bytes" then this	57	In the following, when the documentation refers to of "bytes" then this
54	means characters. As sysread and syswrite are used for all I/O, their	58	means characters. As sysread and syswrite are used for all I/O, their
55	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
56		60
57	All callbacks will be invoked with the handle object as their first	61	All callbacks will be invoked with the handle object as their first
58	argument.	62	argument.
59		63
		64	=head2 SIGPIPE is not handled by this module
		65
		66	SIGPIPE is not handled by this module, so one of the practical
		67	requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} =
		68	'IGNORE'>). At least, this is highly recommend in a networked program: If
		69	you use AnyEvent::Handle in a filter program (like sort), exiting on
		70	SIGPIPE is probably the right thing to do.
		71
60	=head1 METHODS	72	=head1 METHODS
61		73
62	=over 4	74	=over 4
63		75
64	=item B<new (%args)>	76	=item B<new (%args)>
…		…
69		81
70	=item fh => $filehandle [MANDATORY]	82	=item fh => $filehandle [MANDATORY]
71		83
72	The filehandle this L<AnyEvent::Handle> object will operate on.	84	The filehandle this L<AnyEvent::Handle> object will operate on.
73		85
74	NOTE: The filehandle will be set to non-blocking (using	86	NOTE: The filehandle will be set to non-blocking mode (using
75	AnyEvent::Util::fh_nonblocking).	87	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		88	that mode.
76		89
77	=item on_eof => $cb->($self) [MANDATORY]
78
79	Set the callback to be called on EOF.
80
81	=item on_error => $cb->($self)	90	=item on_eof => $cb->($handle)
82		91
		92	Set the callback to be called when an end-of-file condition is detected,
		93	i.e. in the case of a socket, when the other side has closed the
		94	connection cleanly.
		95
		96	For sockets, this just means that the other side has stopped sending data,
		97	you can still try to write data, and, in fact, one can return from the eof
		98	callback and continue writing data, as only the read part has been shut
		99	down.
		100
		101	While not mandatory, it is I<highly> recommended to set an eof callback,
		102	otherwise you might end up with a closed socket while you are still
		103	waiting for data.
		104
		105	If an EOF condition has been detected but no C<on_eof> callback has been
		106	set, then a fatal error will be raised with C<$!> set to <0>.
		107
		108	=item on_error => $cb->($handle, $fatal)
		109
83	This is the fatal error callback, that is called when, well, a fatal error	110	This is the error callback, which is called when, well, some error
84	ocurs, such as not being able to resolve the hostname, failure to connect	111	occured, such as not being able to resolve the hostname, failure to
85	or a read error.	112	connect or a read error.
86		113
87	The object will not be in a usable state when this callback has been	114	Some errors are fatal (which is indicated by C<$fatal> being true). On
88	called.	115	fatal errors the handle object will be shut down and will not be usable
		116	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
		117	errors are an EOF condition with active (but unsatisifable) read watchers
		118	(C<EPIPE>) or I/O errors.
		119
		120	Non-fatal errors can be retried by simply returning, but it is recommended
		121	to simply ignore this parameter and instead abondon the handle object
		122	when this callback is invoked. Examples of non-fatal errors are timeouts
		123	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
89		124
90	On callback entrance, the value of C<$!> contains the operating system	125	On callback entrance, the value of C<$!> contains the operating system
91	error (or C<ENOSPC> or C<EPIPE>).	126	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
92		127
93	While not mandatory, it is I<highly> recommended to set this callback, as	128	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	129	you will not be notified of errors otherwise. The default simply calls
95	die.	130	C<croak>.
96		131
97	=item on_read => $cb->($self)	132	=item on_read => $cb->($handle)
98		133
99	This sets the default read callback, which is called when data arrives	134	This sets the default read callback, which is called when data arrives
100	and no read request is in the queue.	135	and no read request is in the queue (unlike read queue callbacks, this
		136	callback will only be called when at least one octet of data is in the
		137	read buffer).
101		138
102	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	139	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
103	method or acces sthe C<$self->{rbuf}> member directly.	140	method or access the C<$handle->{rbuf}> member directly.
104		141
105	When an EOF condition is detected then AnyEvent::Handle will first try to	142	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	143	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	144	calling the C<on_eof> callback. If no progress can be made, then a fatal
108	error will be raised (with C<$!> set to C<EPIPE>).	145	error will be raised (with C<$!> set to C<EPIPE>).
109		146
110	=item on_drain => $cb->()	147	=item on_drain => $cb->($handle)
111		148
112	This sets the callback that is called when the write buffer becomes empty	149	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).	150	(or when the callback is set and the buffer is empty already).
114		151
115	To append to the write buffer, use the C<< ->push_write >> method.	152	To append to the write buffer, use the C<< ->push_write >> method.
116		153
		154	This callback is useful when you don't want to put all of your write data
		155	into the queue at once, for example, when you want to write the contents
		156	of some file to the socket you might not want to read the whole file into
		157	memory and push it into the queue, but instead only read more data from
		158	the file when the write queue becomes empty.
		159
		160	=item timeout => $fractional_seconds
		161
		162	If non-zero, then this enables an "inactivity" timeout: whenever this many
		163	seconds pass without a successful read or write on the underlying file
		164	handle, the C<on_timeout> callback will be invoked (and if that one is
		165	missing, a non-fatal C<ETIMEDOUT> error will be raised).
		166
		167	Note that timeout processing is also active when you currently do not have
		168	any outstanding read or write requests: If you plan to keep the connection
		169	idle then you should disable the timout temporarily or ignore the timeout
		170	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		171	restart the timeout.
		172
		173	Zero (the default) disables this timeout.
		174
		175	=item on_timeout => $cb->($handle)
		176
		177	Called whenever the inactivity timeout passes. If you return from this
		178	callback, then the timeout will be reset as if some activity had happened,
		179	so this condition is not fatal in any way.
		180
117	=item rbuf_max => <bytes>	181	=item rbuf_max => <bytes>
118		182
119	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	183	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
120	when the read buffer ever (strictly) exceeds this size. This is useful to	184	when the read buffer ever (strictly) exceeds this size. This is useful to
121	avoid denial-of-service attacks.	185	avoid some forms of denial-of-service attacks.
122		186
123	For example, a server accepting connections from untrusted sources should	187	For example, a server accepting connections from untrusted sources should
124	be configured to accept only so-and-so much data that it cannot act on	188	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	189	(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	190	amount of data without a callback ever being called as long as the line
127	isn't finished).	191	isn't finished).
128		192
		193	=item autocork => <boolean>
		194
		195	When disabled (the default), then C<push_write> will try to immediately
		196	write the data to the handle, if possible. This avoids having to register
		197	a write watcher and wait for the next event loop iteration, but can
		198	be inefficient if you write multiple small chunks (on the wire, this
		199	disadvantage is usually avoided by your kernel's nagle algorithm, see
		200	C<no_delay>, but this option can save costly syscalls).
		201
		202	When enabled, then writes will always be queued till the next event loop
		203	iteration. This is efficient when you do many small writes per iteration,
		204	but less efficient when you do a single write only per iteration (or when
		205	the write buffer often is full). It also increases write latency.
		206
		207	=item no_delay => <boolean>
		208
		209	When doing small writes on sockets, your operating system kernel might
		210	wait a bit for more data before actually sending it out. This is called
		211	the Nagle algorithm, and usually it is beneficial.
		212
		213	In some situations you want as low a delay as possible, which can be
		214	accomplishd by setting this option to a true value.
		215
		216	The default is your opertaing system's default behaviour (most likely
		217	enabled), this option explicitly enables or disables it, if possible.
		218
129	=item read_size => <bytes>	219	=item read_size => <bytes>
130		220
131	The default read block size (the amount of bytes this module will try to read	221	The default read block size (the amount of bytes this module will
132	on each [loop iteration). Default: C<4096>.	222	try to read during each loop iteration, which affects memory
		223	requirements). Default: C<8192>.
133		224
134	=item low_water_mark => <bytes>	225	=item low_water_mark => <bytes>
135		226
136	Sets the amount of bytes (default: C<0>) that make up an "empty" write	227	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	228	buffer: If the write reaches this size or gets even samller it is
138	considered empty.	229	considered empty.
139		230
		231	Sometimes it can be beneficial (for performance reasons) to add data to
		232	the write buffer before it is fully drained, but this is a rare case, as
		233	the operating system kernel usually buffers data as well, so the default
		234	is good in almost all cases.
		235
		236	=item linger => <seconds>
		237
		238	If non-zero (default: C<3600>), then the destructor of the
		239	AnyEvent::Handle object will check whether there is still outstanding
		240	write data and will install a watcher that will write this data to the
		241	socket. No errors will be reported (this mostly matches how the operating
		242	system treats outstanding data at socket close time).
		243
		244	This will not work for partial TLS data that could not be encoded
		245	yet. This data will be lost.
		246
		247	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		248
		249	When this parameter is given, it enables TLS (SSL) mode, that means
		250	AnyEvent will start a TLS handshake as soon as the conenction has been
		251	established and will transparently encrypt/decrypt data afterwards.
		252
		253	TLS mode requires Net::SSLeay to be installed (it will be loaded
		254	automatically when you try to create a TLS handle): this module doesn't
		255	have a dependency on that module, so if your module requires it, you have
		256	to add the dependency yourself.
		257
		258	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		259	C<accept>, and for the TLS client side of a connection, use C<connect>
		260	mode.
		261
		262	You can also provide your own TLS connection object, but you have
		263	to make sure that you call either C<Net::SSLeay::set_connect_state>
		264	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		265	AnyEvent::Handle.
		266
		267	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		268
		269	=item tls_ctx => $ssl_ctx
		270
		271	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
		272	(unless a connection object was specified directly). If this parameter is
		273	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		274
		275	=item json => JSON or JSON::XS object
		276
		277	This is the json coder object used by the C<json> read and write types.
		278
		279	If you don't supply it, then AnyEvent::Handle will create and use a
		280	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		281	texts.
		282
		283	Note that you are responsible to depend on the JSON module if you want to
		284	use this functionality, as AnyEvent does not have a dependency itself.
		285
		286	=item filter_r => $cb
		287
		288	=item filter_w => $cb
		289
		290	These exist, but are undocumented at this time. (They are used internally
		291	by the TLS code).
		292
140	=back	293	=back
141		294
142	=cut	295	=cut
143		296
144	sub new {	297	sub new {
…		…
148		301
149	$self->{fh} or Carp::croak "mandatory argument fh is missing";	302	$self->{fh} or Carp::croak "mandatory argument fh is missing";
150		303
151	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	304	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
152		305
153	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	306	if ($self->{tls}) {
		307	require Net::SSLeay;
		308	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		309	}
154		310
155	$self->on_error (delete $self->{on_error}) if $self->{on_error};	311	$self->{_activity} = AnyEvent->now;
		312	$self->_timeout;
		313
156	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	314	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
157	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	315	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
158		316
159	$self->start_read;	317	$self->start_read
		318	if $self->{on_read};
160		319
161	$self	320	$self
162	}	321	}
163		322
164	sub _shutdown {	323	sub _shutdown {
165	my ($self) = @_;	324	my ($self) = @_;
166		325
		326	delete $self->{_tw};
167	delete $self->{rw};	327	delete $self->{_rw};
168	delete $self->{ww};	328	delete $self->{_ww};
169	delete $self->{fh};	329	delete $self->{fh};
170	}
171		330
		331	&_freetls;
		332
		333	delete $self->{on_read};
		334	delete $self->{_queue};
		335	}
		336
172	sub error {	337	sub _error {
173	my ($self) = @_;	338	my ($self, $errno, $fatal) = @_;
174		339
175	{
176	local $!;
177	$self->_shutdown;	340	$self->_shutdown
178	}	341	if $fatal;
		342
		343	$! = $errno;
179		344
180	if ($self->{on_error}) {	345	if ($self->{on_error}) {
181	$self->{on_error}($self);	346	$self->{on_error}($self, $fatal);
182	} else {	347	} else {
183	die "AnyEvent::Handle uncaught fatal error: $!";	348	Carp::croak "AnyEvent::Handle uncaught error: $!";
184	}	349	}
185	}	350	}
186		351
187	=item $fh = $handle->fh	352	=item $fh = $handle->fh
188		353
189	This method returns the filehandle of the L<AnyEvent::Handle> object.	354	This method returns the file handle used to create the L<AnyEvent::Handle> object.
190		355
191	=cut	356	=cut
192		357
193	sub fh { $_[0]->{fh} }	358	sub fh { $_[0]{fh} }
194		359
195	=item $handle->on_error ($cb)	360	=item $handle->on_error ($cb)
196		361
197	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	362	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
198		363
…		…
210		375
211	sub on_eof {	376	sub on_eof {
212	$_[0]{on_eof} = $_[1];	377	$_[0]{on_eof} = $_[1];
213	}	378	}
214		379
		380	=item $handle->on_timeout ($cb)
		381
		382	Replace the current C<on_timeout> callback, or disables the callback (but
		383	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		384	argument and method.
		385
		386	=cut
		387
		388	sub on_timeout {
		389	$_[0]{on_timeout} = $_[1];
		390	}
		391
		392	=item $handle->autocork ($boolean)
		393
		394	Enables or disables the current autocork behaviour (see C<autocork>
		395	constructor argument).
		396
		397	=cut
		398
		399	=item $handle->no_delay ($boolean)
		400
		401	Enables or disables the C<no_delay> setting (see constructor argument of
		402	the same name for details).
		403
		404	=cut
		405
		406	sub no_delay {
		407	$_[0]{no_delay} = $_[1];
		408
		409	eval {
		410	local $SIG{__DIE__};
		411	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		412	};
		413	}
		414
		415	#############################################################################
		416
		417	=item $handle->timeout ($seconds)
		418
		419	Configures (or disables) the inactivity timeout.
		420
		421	=cut
		422
		423	sub timeout {
		424	my ($self, $timeout) = @_;
		425
		426	$self->{timeout} = $timeout;
		427	$self->_timeout;
		428	}
		429
		430	# reset the timeout watcher, as neccessary
		431	# also check for time-outs
		432	sub _timeout {
		433	my ($self) = @_;
		434
		435	if ($self->{timeout}) {
		436	my $NOW = AnyEvent->now;
		437
		438	# when would the timeout trigger?
		439	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		440
		441	# now or in the past already?
		442	if ($after <= 0) {
		443	$self->{_activity} = $NOW;
		444
		445	if ($self->{on_timeout}) {
		446	$self->{on_timeout}($self);
		447	} else {
		448	$self->_error (&Errno::ETIMEDOUT);
		449	}
		450
		451	# callback could have changed timeout value, optimise
		452	return unless $self->{timeout};
		453
		454	# calculate new after
		455	$after = $self->{timeout};
		456	}
		457
		458	Scalar::Util::weaken $self;
		459	return unless $self; # ->error could have destroyed $self
		460
		461	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		462	delete $self->{_tw};
		463	$self->_timeout;
		464	});
		465	} else {
		466	delete $self->{_tw};
		467	}
		468	}
		469
215	#############################################################################	470	#############################################################################
216		471
217	=back	472	=back
218		473
219	=head2 WRITE QUEUE	474	=head2 WRITE QUEUE
…		…
222	for reading.	477	for reading.
223		478
224	The write queue is very simple: you can add data to its end, and	479	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.	480	AnyEvent::Handle will automatically try to get rid of it for you.
226		481
227	When data could be writtena nd the write buffer is shorter then the low	482	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.	483	water mark, the C<on_drain> callback will be invoked.
229		484
230	=over 4	485	=over 4
231		486
232	=item $handle->on_drain ($cb)	487	=item $handle->on_drain ($cb)
…		…
251	want (only limited by the available memory), as C<AnyEvent::Handle>	506	want (only limited by the available memory), as C<AnyEvent::Handle>
252	buffers it independently of the kernel.	507	buffers it independently of the kernel.
253		508
254	=cut	509	=cut
255		510
256	sub push_write {	511	sub _drain_wbuf {
257	my ($self, $data) = @_;	512	my ($self) = @_;
258		513
259	$self->{wbuf} .= $data;	514	if (!$self->{_ww} && length $self->{wbuf}) {
260		515
261	unless ($self->{ww}) {
262	Scalar::Util::weaken $self;	516	Scalar::Util::weaken $self;
		517
263	my $cb = sub {	518	my $cb = sub {
264	my $len = syswrite $self->{fh}, $self->{wbuf};	519	my $len = syswrite $self->{fh}, $self->{wbuf};
265		520
266	if ($len > 0) {	521	if ($len >= 0) {
267	substr $self->{wbuf}, 0, $len, "";	522	substr $self->{wbuf}, 0, $len, "";
268		523
		524	$self->{_activity} = AnyEvent->now;
269		525
270	$self->{on_drain}($self)	526	$self->{on_drain}($self)
271	if $self->{low_water_mark} >= length $self->{wbuf}	527	if $self->{low_water_mark} >= length $self->{wbuf}
272	&& $self->{on_drain};	528	&& $self->{on_drain};
273		529
274	delete $self->{ww} unless length $self->{wbuf};	530	delete $self->{_ww} unless length $self->{wbuf};
275	} elsif ($! != EAGAIN && $! != EINTR) {	531	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
276	$self->error;	532	$self->_error ($!, 1);
277	}	533	}
278	};	534	};
279		535
		536	# try to write data immediately
		537	$cb->() unless $self->{autocork};
		538
		539	# if still data left in wbuf, we need to poll
280	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	540	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
281		541	if length $self->{wbuf};
282	$cb->($self);
283	};	542	};
284	}	543	}
		544
		545	our %WH;
		546
		547	sub register_write_type($$) {
		548	$WH{$_[0]} = $_[1];
		549	}
		550
		551	sub push_write {
		552	my $self = shift;
		553
		554	if (@_ > 1) {
		555	my $type = shift;
		556
		557	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		558	->($self, @_);
		559	}
		560
		561	if ($self->{filter_w}) {
		562	$self->{filter_w}($self, \$_[0]);
		563	} else {
		564	$self->{wbuf} .= $_[0];
		565	$self->_drain_wbuf;
		566	}
		567	}
		568
		569	=item $handle->push_write (type => @args)
		570
		571	Instead of formatting your data yourself, you can also let this module do
		572	the job by specifying a type and type-specific arguments.
		573
		574	Predefined types are (if you have ideas for additional types, feel free to
		575	drop by and tell us):
		576
		577	=over 4
		578
		579	=item netstring => $string
		580
		581	Formats the given value as netstring
		582	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		583
		584	=cut
		585
		586	register_write_type netstring => sub {
		587	my ($self, $string) = @_;
		588
		589	sprintf "%d:%s,", (length $string), $string
		590	};
		591
		592	=item packstring => $format, $data
		593
		594	An octet string prefixed with an encoded length. The encoding C<$format>
		595	uses the same format as a Perl C<pack> format, but must specify a single
		596	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		597	optional C<!>, C<< < >> or C<< > >> modifier).
		598
		599	=cut
		600
		601	register_write_type packstring => sub {
		602	my ($self, $format, $string) = @_;
		603
		604	pack "$format/a*", $string
		605	};
		606
		607	=item json => $array_or_hashref
		608
		609	Encodes the given hash or array reference into a JSON object. Unless you
		610	provide your own JSON object, this means it will be encoded to JSON text
		611	in UTF-8.
		612
		613	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		614	one end of a handle and read them at the other end without using any
		615	additional framing.
		616
		617	The generated JSON text is guaranteed not to contain any newlines: While
		618	this module doesn't need delimiters after or between JSON texts to be
		619	able to read them, many other languages depend on that.
		620
		621	A simple RPC protocol that interoperates easily with others is to send
		622	JSON arrays (or objects, although arrays are usually the better choice as
		623	they mimic how function argument passing works) and a newline after each
		624	JSON text:
		625
		626	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		627	$handle->push_write ("\012");
		628
		629	An AnyEvent::Handle receiver would simply use the C<json> read type and
		630	rely on the fact that the newline will be skipped as leading whitespace:
		631
		632	$handle->push_read (json => sub { my $array = $_[1]; ... });
		633
		634	Other languages could read single lines terminated by a newline and pass
		635	this line into their JSON decoder of choice.
		636
		637	=cut
		638
		639	register_write_type json => sub {
		640	my ($self, $ref) = @_;
		641
		642	require JSON;
		643
		644	$self->{json} ? $self->{json}->encode ($ref)
		645	: JSON::encode_json ($ref)
		646	};
		647
		648	=item storable => $reference
		649
		650	Freezes the given reference using L<Storable> and writes it to the
		651	handle. Uses the C<nfreeze> format.
		652
		653	=cut
		654
		655	register_write_type storable => sub {
		656	my ($self, $ref) = @_;
		657
		658	require Storable;
		659
		660	pack "w/a*", Storable::nfreeze ($ref)
		661	};
		662
		663	=back
		664
		665	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		666
		667	This function (not method) lets you add your own types to C<push_write>.
		668	Whenever the given C<type> is used, C<push_write> will invoke the code
		669	reference with the handle object and the remaining arguments.
		670
		671	The code reference is supposed to return a single octet string that will
		672	be appended to the write buffer.
		673
		674	Note that this is a function, and all types registered this way will be
		675	global, so try to use unique names.
		676
		677	=cut
285		678
286	#############################################################################	679	#############################################################################
287		680
288	=back	681	=back
289		682
…		…
296	ways, the "simple" way, using only C<on_read> and the "complex" way, using	689	ways, the "simple" way, using only C<on_read> and the "complex" way, using
297	a queue.	690	a queue.
298		691
299	In the simple case, you just install an C<on_read> callback and whenever	692	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	693	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	694	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
302	or not.	695	leave the data there if you want to accumulate more (e.g. when only a
		696	partial message has been received so far).
303		697
304	In the more complex case, you want to queue multiple callbacks. In this	698	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	699	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>,	700	data arrives (also the first time it is queued) and removes it when it has
307	below).	701	done its job (see C<push_read>, below).
308		702
309	This way you can, for example, push three line-reads, followed by reading	703	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.	704	a chunk of data, and AnyEvent::Handle will execute them in order.
311		705
312	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	706	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
313	the specified number of bytes which give an XML datagram.	707	the specified number of bytes which give an XML datagram.
314		708
315	# in the default state, expect some header bytes	709	# in the default state, expect some header bytes
316	$handle->on_read (sub {	710	$handle->on_read (sub {
317	# some data is here, now queue the length-header-read (4 octets)	711	# some data is here, now queue the length-header-read (4 octets)
318	shift->unshift_read_chunk (4, sub {	712	shift->unshift_read (chunk => 4, sub {
319	# header arrived, decode	713	# header arrived, decode
320	my $len = unpack "N", $_[1];	714	my $len = unpack "N", $_[1];
321		715
322	# now read the payload	716	# now read the payload
323	shift->unshift_read_chunk ($len, sub {	717	shift->unshift_read (chunk => $len, sub {
324	my $xml = $_[1];	718	my $xml = $_[1];
325	# handle xml	719	# handle xml
326	});	720	});
327	});	721	});
328	});	722	});
329		723
330	Example 2: Implement a client for a protocol that replies either with	724	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	725	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	726	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	727	just pipeline sending both requests and manipulate the queue as necessary
334	the callbacks:	728	in the callbacks.
335		729
336	# request one	730	When the first callback is called and sees an "OK" response, it will
		731	C<unshift> another line-read. This line-read will be queued I<before> the
		732	64-byte chunk callback.
		733
		734	# request one, returns either "OK + extra line" or "ERROR"
337	$handle->push_write ("request 1\015\012");	735	$handle->push_write ("request 1\015\012");
338		736
339	# we expect "ERROR" or "OK" as response, so push a line read	737	# we expect "ERROR" or "OK" as response, so push a line read
340	$handle->push_read_line (sub {	738	$handle->push_read (line => sub {
341	# if we got an "OK", we have to _prepend_ another line,	739	# 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	740	# 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	741	# which are already in the queue when this callback is called
344	# we don't do this in case we got an error	742	# we don't do this in case we got an error
345	if ($_[1] eq "OK") {	743	if ($_[1] eq "OK") {
346	$_[0]->unshift_read_line (sub {	744	$_[0]->unshift_read (line => sub {
347	my $response = $_[1];	745	my $response = $_[1];
348	...	746	...
349	});	747	});
350	}	748	}
351	});	749	});
352		750
353	# request two	751	# request two, simply returns 64 octets
354	$handle->push_write ("request 2\015\012");	752	$handle->push_write ("request 2\015\012");
355		753
356	# simply read 64 bytes, always	754	# simply read 64 bytes, always
357	$handle->push_read_chunk (64, sub {	755	$handle->push_read (chunk => 64, sub {
358	my $response = $_[1];	756	my $response = $_[1];
359	...	757	...
360	});	758	});
361		759
362	=over 4	760	=over 4
…		…
364	=cut	762	=cut
365		763
366	sub _drain_rbuf {	764	sub _drain_rbuf {
367	my ($self) = @_;	765	my ($self) = @_;
368		766
369	return if $self->{in_drain};
370	local $self->{in_drain} = 1;	767	local $self->{_in_drain} = 1;
371		768
		769	if (
		770	defined $self->{rbuf_max}
		771	&& $self->{rbuf_max} < length $self->{rbuf}
		772	) {
		773	$self->_error (&Errno::ENOSPC, 1), return;
		774	}
		775
		776	while () {
372	while (my $len = length $self->{rbuf}) {	777	my $len = length $self->{rbuf};
373	no strict 'refs';	778
374	if (my $cb = shift @{ $self->{queue} }) {	779	if (my $cb = shift @{ $self->{_queue} }) {
375	if (!$cb->($self)) {	780	unless ($cb->($self)) {
376	if ($self->{eof}) {	781	if ($self->{_eof}) {
377	# no progress can be made (not enough data and no data forthcoming)	782	# no progress can be made (not enough data and no data forthcoming)
378	$! = &Errno::EPIPE; return $self->error;	783	$self->_error (&Errno::EPIPE, 1), return;
379	}	784	}
380		785
381	unshift @{ $self->{queue} }, $cb;	786	unshift @{ $self->{_queue} }, $cb;
382	return;	787	last;
383	}	788	}
384	} elsif ($self->{on_read}) {	789	} elsif ($self->{on_read}) {
		790	last unless $len;
		791
385	$self->{on_read}($self);	792	$self->{on_read}($self);
386		793
387	if (	794	if (
388	$self->{eof} # if no further data will arrive
389	&& $len == length $self->{rbuf} # and no data has been consumed	795	$len == length $self->{rbuf} # if no data has been consumed
390	&& !@{ $self->{queue} } # and the queue is still empty	796	&& !@{ $self->{_queue} } # and the queue is still empty
391	&& $self->{on_read} # and we still want to read data	797	&& $self->{on_read} # but we still have on_read
392	) {	798	) {
		799	# no further data will arrive
393	# then no progress can be made	800	# so no progress can be made
394	$! = &Errno::EPIPE; return $self->error;	801	$self->_error (&Errno::EPIPE, 1), return
		802	if $self->{_eof};
		803
		804	last; # more data might arrive
395	}	805	}
396	} else {	806	} else {
397	# read side becomes idle	807	# read side becomes idle
398	delete $self->{rw};	808	delete $self->{_rw};
399	return;	809	last;
400	}	810	}
401	}	811	}
402		812
403	if ($self->{eof}) {	813	if ($self->{_eof}) {
404	$self->_shutdown;	814	if ($self->{on_eof}) {
405	$self->{on_eof}($self);	815	$self->{on_eof}($self)
		816	} else {
		817	$self->_error (0, 1);
		818	}
		819	}
		820
		821	# may need to restart read watcher
		822	unless ($self->{_rw}) {
		823	$self->start_read
		824	if $self->{on_read} || @{ $self->{_queue} };
406	}	825	}
407	}	826	}
408		827
409	=item $handle->on_read ($cb)	828	=item $handle->on_read ($cb)
410		829
…		…
416		835
417	sub on_read {	836	sub on_read {
418	my ($self, $cb) = @_;	837	my ($self, $cb) = @_;
419		838
420	$self->{on_read} = $cb;	839	$self->{on_read} = $cb;
		840	$self->_drain_rbuf if $cb && !$self->{_in_drain};
421	}	841	}
422		842
423	=item $handle->rbuf	843	=item $handle->rbuf
424		844
425	Returns the read buffer (as a modifiable lvalue).	845	Returns the read buffer (as a modifiable lvalue).
…		…
444	Append the given callback to the end of the queue (C<push_read>) or	864	Append the given callback to the end of the queue (C<push_read>) or
445	prepend it (C<unshift_read>).	865	prepend it (C<unshift_read>).
446		866
447	The callback is called each time some additional read data arrives.	867	The callback is called each time some additional read data arrives.
448		868
449	It must check wether enough data is in the read buffer already.	869	It must check whether enough data is in the read buffer already.
450		870
451	If not enough data is available, it must return the empty list or a false	871	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	872	value, in which case it will be called repeatedly until enough data is
453	available (or an error condition is detected).	873	available (or an error condition is detected).
454		874
…		…
456	interested in (which can be none at all) and return a true value. After returning	876	interested in (which can be none at all) and return a true value. After returning
457	true, it will be removed from the queue.	877	true, it will be removed from the queue.
458		878
459	=cut	879	=cut
460		880
		881	our %RH;
		882
		883	sub register_read_type($$) {
		884	$RH{$_[0]} = $_[1];
		885	}
		886
461	sub push_read {	887	sub push_read {
462	my ($self, $cb) = @_;	888	my $self = shift;
		889	my $cb = pop;
463		890
		891	if (@_) {
		892	my $type = shift;
		893
		894	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		895	->($self, $cb, @_);
		896	}
		897
464	push @{ $self->{queue} }, $cb;	898	push @{ $self->{_queue} }, $cb;
465	$self->_drain_rbuf;	899	$self->_drain_rbuf unless $self->{_in_drain};
466	}	900	}
467		901
468	sub unshift_read {	902	sub unshift_read {
469	my ($self, $cb) = @_;	903	my $self = shift;
		904	my $cb = pop;
470		905
		906	if (@_) {
		907	my $type = shift;
		908
		909	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		910	->($self, $cb, @_);
		911	}
		912
		913
471	push @{ $self->{queue} }, $cb;	914	unshift @{ $self->{_queue} }, $cb;
472	$self->_drain_rbuf;	915	$self->_drain_rbuf unless $self->{_in_drain};
473	}	916	}
474		917
475	=item $handle->push_read_chunk ($len, $cb->($self, $data))	918	=item $handle->push_read (type => @args, $cb)
476		919
477	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	920	=item $handle->unshift_read (type => @args, $cb)
478		921
479	Append the given callback to the end of the queue (C<push_read_chunk>) or	922	Instead of providing a callback that parses the data itself you can chose
480	prepend it (C<unshift_read_chunk>).	923	between a number of predefined parsing formats, for chunks of data, lines
		924	etc.
481		925
482	The callback will be called only once C<$len> bytes have been read, and	926	Predefined types are (if you have ideas for additional types, feel free to
483	these C<$len> bytes will be passed to the callback.	927	drop by and tell us):
484		928
485	=cut	929	=over 4
486		930
487	sub _read_chunk($$) {	931	=item chunk => $octets, $cb->($handle, $data)
		932
		933	Invoke the callback only once C<$octets> bytes have been read. Pass the
		934	data read to the callback. The callback will never be called with less
		935	data.
		936
		937	Example: read 2 bytes.
		938
		939	$handle->push_read (chunk => 2, sub {
		940	warn "yay ", unpack "H*", $_[1];
		941	});
		942
		943	=cut
		944
		945	register_read_type chunk => sub {
488	my ($self, $len, $cb) = @_;	946	my ($self, $cb, $len) = @_;
489		947
490	sub {	948	sub {
491	$len <= length $_[0]{rbuf} or return;	949	$len <= length $_[0]{rbuf} or return;
492	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	950	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
493	1	951	1
494	}	952	}
495	}	953	};
496		954
497	sub push_read_chunk {	955	=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		956
513	The callback will be called only once a full line (including the end of	957	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	958	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	959	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>).	960	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	971	Partial lines at the end of the stream will never be returned, as they are
528	not marked by the end of line marker.	972	not marked by the end of line marker.
529		973
530	=cut	974	=cut
531		975
532	sub _read_line($$) {	976	register_read_type line => sub {
533	my $self = shift;	977	my ($self, $cb, $eol) = @_;
534	my $cb = pop;
535	my $eol = @_ ? shift : qr|(\015?\012)|;
536	my $pos;
537		978
		979	if (@_ < 3) {
		980	# this is more than twice as fast as the generic code below
		981	sub {
		982	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		983
		984	$cb->($_[0], $1, $2);
		985	1
		986	}
		987	} else {
538	$eol = quotemeta $eol unless ref $eol;	988	$eol = quotemeta $eol unless ref $eol;
539	$eol = qr|^(.*?)($eol)|s;	989	$eol = qr|^(.*?)($eol)|s;
		990
		991	sub {
		992	$_[0]{rbuf} =~ s/$eol// or return;
		993
		994	$cb->($_[0], $1, $2);
		995	1
		996	}
		997	}
		998	};
		999
		1000	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1001
		1002	Makes a regex match against the regex object C<$accept> and returns
		1003	everything up to and including the match.
		1004
		1005	Example: read a single line terminated by '\n'.
		1006
		1007	$handle->push_read (regex => qr<\n>, sub { ... });
		1008
		1009	If C<$reject> is given and not undef, then it determines when the data is
		1010	to be rejected: it is matched against the data when the C<$accept> regex
		1011	does not match and generates an C<EBADMSG> error when it matches. This is
		1012	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1013	receive buffer overflow).
		1014
		1015	Example: expect a single decimal number followed by whitespace, reject
		1016	anything else (not the use of an anchor).
		1017
		1018	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1019
		1020	If C<$skip> is given and not C<undef>, then it will be matched against
		1021	the receive buffer when neither C<$accept> nor C<$reject> match,
		1022	and everything preceding and including the match will be accepted
		1023	unconditionally. This is useful to skip large amounts of data that you
		1024	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1025	have to start matching from the beginning. This is purely an optimisation
		1026	and is usually worth only when you expect more than a few kilobytes.
		1027
		1028	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1029	expect the header to be very large (it isn't in practise, but...), we use
		1030	a skip regex to skip initial portions. The skip regex is tricky in that
		1031	it only accepts something not ending in either \015 or \012, as these are
		1032	required for the accept regex.
		1033
		1034	$handle->push_read (regex =>
		1035	qr<\015\012\015\012>,
		1036	undef, # no reject
		1037	qr<^.*[^\015\012]>,
		1038	sub { ... });
		1039
		1040	=cut
		1041
		1042	register_read_type regex => sub {
		1043	my ($self, $cb, $accept, $reject, $skip) = @_;
		1044
		1045	my $data;
		1046	my $rbuf = \$self->{rbuf};
540		1047
541	sub {	1048	sub {
542	$_[0]{rbuf} =~ s/$eol// or return;	1049	# accept
		1050	if ($$rbuf =~ $accept) {
		1051	$data .= substr $$rbuf, 0, $+[0], "";
		1052	$cb->($self, $data);
		1053	return 1;
		1054	}
		1055
		1056	# reject
		1057	if ($reject && $$rbuf =~ $reject) {
		1058	$self->_error (&Errno::EBADMSG);
		1059	}
543		1060
544	$cb->($_[0], $1, $2);	1061	# skip
		1062	if ($skip && $$rbuf =~ $skip) {
		1063	$data .= substr $$rbuf, 0, $+[0], "";
		1064	}
		1065
		1066	()
		1067	}
		1068	};
		1069
		1070	=item netstring => $cb->($handle, $string)
		1071
		1072	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1073
		1074	Throws an error with C<$!> set to EBADMSG on format violations.
		1075
		1076	=cut
		1077
		1078	register_read_type netstring => sub {
		1079	my ($self, $cb) = @_;
		1080
		1081	sub {
		1082	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1083	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1084	$self->_error (&Errno::EBADMSG);
		1085	}
		1086	return;
		1087	}
		1088
		1089	my $len = $1;
		1090
		1091	$self->unshift_read (chunk => $len, sub {
		1092	my $string = $_[1];
		1093	$_[0]->unshift_read (chunk => 1, sub {
		1094	if ($_[1] eq ",") {
		1095	$cb->($_[0], $string);
		1096	} else {
		1097	$self->_error (&Errno::EBADMSG);
		1098	}
		1099	});
		1100	});
		1101
545	1	1102	1
546	}	1103	}
547	}	1104	};
548		1105
549	sub push_read_line {	1106	=item packstring => $format, $cb->($handle, $string)
550	$_[0]->push_read (&_read_line);
551	}
552		1107
553	sub unshift_read_line {	1108	An octet string prefixed with an encoded length. The encoding C<$format>
554	$_[0]->unshift_read (&_read_line);	1109	uses the same format as a Perl C<pack> format, but must specify a single
555	}	1110	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1111	optional C<!>, C<< < >> or C<< > >> modifier).
		1112
		1113	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1114
		1115	Example: read a block of data prefixed by its length in BER-encoded
		1116	format (very efficient).
		1117
		1118	$handle->push_read (packstring => "w", sub {
		1119	my ($handle, $data) = @_;
		1120	});
		1121
		1122	=cut
		1123
		1124	register_read_type packstring => sub {
		1125	my ($self, $cb, $format) = @_;
		1126
		1127	sub {
		1128	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1129	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1130	or return;
		1131
		1132	$format = length pack $format, $len;
		1133
		1134	# bypass unshift if we already have the remaining chunk
		1135	if ($format + $len <= length $_[0]{rbuf}) {
		1136	my $data = substr $_[0]{rbuf}, $format, $len;
		1137	substr $_[0]{rbuf}, 0, $format + $len, "";
		1138	$cb->($_[0], $data);
		1139	} else {
		1140	# remove prefix
		1141	substr $_[0]{rbuf}, 0, $format, "";
		1142
		1143	# read remaining chunk
		1144	$_[0]->unshift_read (chunk => $len, $cb);
		1145	}
		1146
		1147	1
		1148	}
		1149	};
		1150
		1151	=item json => $cb->($handle, $hash_or_arrayref)
		1152
		1153	Reads a JSON object or array, decodes it and passes it to the callback.
		1154
		1155	If a C<json> object was passed to the constructor, then that will be used
		1156	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1157
		1158	This read type uses the incremental parser available with JSON version
		1159	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1160	dependency on your own: this module will load the JSON module, but
		1161	AnyEvent does not depend on it itself.
		1162
		1163	Since JSON texts are fully self-delimiting, the C<json> read and write
		1164	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1165	the C<json> write type description, above, for an actual example.
		1166
		1167	=cut
		1168
		1169	register_read_type json => sub {
		1170	my ($self, $cb) = @_;
		1171
		1172	require JSON;
		1173
		1174	my $data;
		1175	my $rbuf = \$self->{rbuf};
		1176
		1177	my $json = $self->{json} ||= JSON->new->utf8;
		1178
		1179	sub {
		1180	my $ref = $json->incr_parse ($self->{rbuf});
		1181
		1182	if ($ref) {
		1183	$self->{rbuf} = $json->incr_text;
		1184	$json->incr_text = "";
		1185	$cb->($self, $ref);
		1186
		1187	1
		1188	} else {
		1189	$self->{rbuf} = "";
		1190	()
		1191	}
		1192	}
		1193	};
		1194
		1195	=item storable => $cb->($handle, $ref)
		1196
		1197	Deserialises a L<Storable> frozen representation as written by the
		1198	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1199	data).
		1200
		1201	Raises C<EBADMSG> error if the data could not be decoded.
		1202
		1203	=cut
		1204
		1205	register_read_type storable => sub {
		1206	my ($self, $cb) = @_;
		1207
		1208	require Storable;
		1209
		1210	sub {
		1211	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1212	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1213	or return;
		1214
		1215	my $format = length pack "w", $len;
		1216
		1217	# bypass unshift if we already have the remaining chunk
		1218	if ($format + $len <= length $_[0]{rbuf}) {
		1219	my $data = substr $_[0]{rbuf}, $format, $len;
		1220	substr $_[0]{rbuf}, 0, $format + $len, "";
		1221	$cb->($_[0], Storable::thaw ($data));
		1222	} else {
		1223	# remove prefix
		1224	substr $_[0]{rbuf}, 0, $format, "";
		1225
		1226	# read remaining chunk
		1227	$_[0]->unshift_read (chunk => $len, sub {
		1228	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1229	$cb->($_[0], $ref);
		1230	} else {
		1231	$self->_error (&Errno::EBADMSG);
		1232	}
		1233	});
		1234	}
		1235
		1236	1
		1237	}
		1238	};
		1239
		1240	=back
		1241
		1242	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1243
		1244	This function (not method) lets you add your own types to C<push_read>.
		1245
		1246	Whenever the given C<type> is used, C<push_read> will invoke the code
		1247	reference with the handle object, the callback and the remaining
		1248	arguments.
		1249
		1250	The code reference is supposed to return a callback (usually a closure)
		1251	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1252
		1253	It should invoke the passed callback when it is done reading (remember to
		1254	pass C<$handle> as first argument as all other callbacks do that).
		1255
		1256	Note that this is a function, and all types registered this way will be
		1257	global, so try to use unique names.
		1258
		1259	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1260	search for C<register_read_type>)).
556		1261
557	=item $handle->stop_read	1262	=item $handle->stop_read
558		1263
559	=item $handle->start_read	1264	=item $handle->start_read
560		1265
561	In rare cases you actually do not want to read anything form the	1266	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	1267	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	1268	any queued callbacks will be executed then. To start reading again, call
564	C<start_read>.	1269	C<start_read>.
		1270
		1271	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1272	you change the C<on_read> callback or push/unshift a read callback, and it
		1273	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1274	there are any read requests in the queue.
565		1275
566	=cut	1276	=cut
567		1277
568	sub stop_read {	1278	sub stop_read {
569	my ($self) = @_;	1279	my ($self) = @_;
570		1280
571	delete $self->{rw};	1281	delete $self->{_rw};
572	}	1282	}
573		1283
574	sub start_read {	1284	sub start_read {
575	my ($self) = @_;	1285	my ($self) = @_;
576		1286
577	unless ($self->{rw} || $self->{eof}) {	1287	unless ($self->{_rw} || $self->{_eof}) {
578	Scalar::Util::weaken $self;	1288	Scalar::Util::weaken $self;
579		1289
580	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1290	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1291	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
581	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1292	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
582		1293
583	if ($len > 0) {	1294	if ($len > 0) {
584	if (defined $self->{rbuf_max}) {	1295	$self->{_activity} = AnyEvent->now;
585	if ($self->{rbuf_max} < length $self->{rbuf}) {	1296
586	$! = &Errno::ENOSPC; return $self->error;	1297	$self->{filter_r}
587	}	1298	? $self->{filter_r}($self, $rbuf)
588	}	1299	: $self->{_in_drain} || $self->_drain_rbuf;
589		1300
590	} elsif (defined $len) {	1301	} elsif (defined $len) {
591	$self->{eof} = 1;
592	delete $self->{rw};	1302	delete $self->{_rw};
		1303	$self->{_eof} = 1;
		1304	$self->_drain_rbuf unless $self->{_in_drain};
593		1305
594	} elsif ($! != EAGAIN && $! != EINTR) {	1306	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
595	return $self->error;	1307	return $self->_error ($!, 1);
596	}	1308	}
597
598	$self->_drain_rbuf;
599	});	1309	});
600	}	1310	}
601	}	1311	}
602		1312
		1313	sub _dotls {
		1314	my ($self) = @_;
		1315
		1316	my $buf;
		1317
		1318	if (length $self->{_tls_wbuf}) {
		1319	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1320	substr $self->{_tls_wbuf}, 0, $len, "";
		1321	}
		1322	}
		1323
		1324	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1325	unless (length $buf) {
		1326	# let's treat SSL-eof as we treat normal EOF
		1327	delete $self->{_rw};
		1328	$self->{_eof} = 1;
		1329	&_freetls;
		1330	}
		1331
		1332	$self->{rbuf} .= $buf;
		1333	$self->_drain_rbuf unless $self->{_in_drain};
		1334	$self->{tls} or return; # tls session might have gone away in callback
		1335	}
		1336
		1337	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1338
		1339	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1340	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1341	return $self->_error ($!, 1);
		1342	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1343	return $self->_error (&Errno::EIO, 1);
		1344	}
		1345
		1346	# all others are fine for our purposes
		1347	}
		1348
		1349	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1350	$self->{wbuf} .= $buf;
		1351	$self->_drain_wbuf;
		1352	}
		1353	}
		1354
		1355	=item $handle->starttls ($tls[, $tls_ctx])
		1356
		1357	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1358	object is created, you can also do that at a later time by calling
		1359	C<starttls>.
		1360
		1361	The first argument is the same as the C<tls> constructor argument (either
		1362	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1363
		1364	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1365	used when AnyEvent::Handle has to create its own TLS connection object.
		1366
		1367	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1368	call and can be used or changed to your liking. Note that the handshake
		1369	might have already started when this function returns.
		1370
		1371	If it an error to start a TLS handshake more than once per
		1372	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1373
		1374	=cut
		1375
		1376	sub starttls {
		1377	my ($self, $ssl, $ctx) = @_;
		1378
		1379	Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"
		1380	if $self->{tls};
		1381
		1382	if ($ssl eq "accept") {
		1383	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1384	Net::SSLeay::set_accept_state ($ssl);
		1385	} elsif ($ssl eq "connect") {
		1386	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1387	Net::SSLeay::set_connect_state ($ssl);
		1388	}
		1389
		1390	$self->{tls} = $ssl;
		1391
		1392	# basically, this is deep magic (because SSL_read should have the same issues)
		1393	# but the openssl maintainers basically said: "trust us, it just works".
		1394	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1395	# and mismaintained ssleay-module doesn't even offer them).
		1396	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1397	#
		1398	# in short: this is a mess.
		1399	#
		1400	# note that we do not try to kepe the length constant between writes as we are required to do.
		1401	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1402	# and we drive openssl fully in blocking mode here.
		1403	Net::SSLeay::CTX_set_mode ($self->{tls},
		1404	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1405	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1406
		1407	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1408	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1409
		1410	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1411
		1412	$self->{filter_w} = sub {
		1413	$_[0]{_tls_wbuf} .= ${$_[1]};
		1414	&_dotls;
		1415	};
		1416	$self->{filter_r} = sub {
		1417	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1418	&_dotls;
		1419	};
		1420
		1421	&_dotls; # need to trigger the initial negotiation exchange
		1422	}
		1423
		1424	=item $handle->stoptls
		1425
		1426	Shuts down the SSL connection - this makes a proper EOF handshake by
		1427	sending a close notify to the other side, but since OpenSSL doesn't
		1428	support non-blocking shut downs, it is not possible to re-use the stream
		1429	afterwards.
		1430
		1431	=cut
		1432
		1433	sub stoptls {
		1434	my ($self) = @_;
		1435
		1436	if ($self->{tls}) {
		1437	Net::SSLeay::shutdown $self->{tls};
		1438
		1439	&_dotls;
		1440
		1441	# we don't give a shit. no, we do, but we can't. no...
		1442	# we, we... have to use openssl :/
		1443	&_freetls;
		1444	}
		1445	}
		1446
		1447	sub _freetls {
		1448	my ($self) = @_;
		1449
		1450	return unless $self->{tls};
		1451
		1452	Net::SSLeay::free (delete $self->{tls});
		1453
		1454	delete @$self{qw(_rbio filter_w _wbio filter_r)};
		1455	}
		1456
		1457	sub DESTROY {
		1458	my $self = shift;
		1459
		1460	&_freetls;
		1461
		1462	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1463
		1464	if ($linger && length $self->{wbuf}) {
		1465	my $fh = delete $self->{fh};
		1466	my $wbuf = delete $self->{wbuf};
		1467
		1468	my @linger;
		1469
		1470	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1471	my $len = syswrite $fh, $wbuf, length $wbuf;
		1472
		1473	if ($len > 0) {
		1474	substr $wbuf, 0, $len, "";
		1475	} else {
		1476	@linger = (); # end
		1477	}
		1478	});
		1479	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1480	@linger = ();
		1481	});
		1482	}
		1483	}
		1484
		1485	=item AnyEvent::Handle::TLS_CTX
		1486
		1487	This function creates and returns the Net::SSLeay::CTX object used by
		1488	default for TLS mode.
		1489
		1490	The context is created like this:
		1491
		1492	Net::SSLeay::load_error_strings;
		1493	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1494	Net::SSLeay::randomize;
		1495
		1496	my $CTX = Net::SSLeay::CTX_new;
		1497
		1498	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1499
		1500	=cut
		1501
		1502	our $TLS_CTX;
		1503
		1504	sub TLS_CTX() {
		1505	$TLS_CTX || do {
		1506	require Net::SSLeay;
		1507
		1508	Net::SSLeay::load_error_strings ();
		1509	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1510	Net::SSLeay::randomize ();
		1511
		1512	$TLS_CTX = Net::SSLeay::CTX_new ();
		1513
		1514	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1515
		1516	$TLS_CTX
		1517	}
		1518	}
		1519
603	=back	1520	=back
604		1521
		1522	=head1 SUBCLASSING AnyEvent::Handle
		1523
		1524	In many cases, you might want to subclass AnyEvent::Handle.
		1525
		1526	To make this easier, a given version of AnyEvent::Handle uses these
		1527	conventions:
		1528
		1529	=over 4
		1530
		1531	=item * all constructor arguments become object members.
		1532
		1533	At least initially, when you pass a C<tls>-argument to the constructor it
		1534	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1535	mutated later on (for example C<tls> will hold the TLS connection object).
		1536
		1537	=item * other object member names are prefixed with an C<_>.
		1538
		1539	All object members not explicitly documented (internal use) are prefixed
		1540	with an underscore character, so the remaining non-C<_>-namespace is free
		1541	for use for subclasses.
		1542
		1543	=item * all members not documented here and not prefixed with an underscore
		1544	are free to use in subclasses.
		1545
		1546	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1547	member variables, but thats just life, at least it is documented.
		1548
		1549	=back
		1550
605	=head1 AUTHOR	1551	=head1 AUTHOR
606		1552
607	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1553	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
608		1554
609	=cut	1555	=cut

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