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Revision 1.17 by root, Sat May 24 04:17:45 2008 UTC vs.
Revision 1.118 by root, Thu Feb 12 17:33:38 2009 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 = 4.34;
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->send;
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)	82	=item on_eof => $cb->($handle)
78		83
79	Set the callback to be called on EOF.	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.
80		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
81	While not mandatory, it is highly recommended to set an eof callback,	93	While not mandatory, it is I<highly> recommended to set an EOF callback,
82	otherwise you might end up with a closed socket while you are still	94	otherwise you might end up with a closed socket while you are still
83	waiting for data.	95	waiting for data.
84		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
85	=item on_error => $cb->($self)	100	=item on_error => $cb->($handle, $fatal)
86		101
87	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	104	connect or a read error.
90		105
91	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	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>).
93		116
94	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		119
97	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
98	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
99	die.	122	C<croak>.
100		123
101	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
102		125
103	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
104	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).
105		130
106	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 >>
107	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly. Note that you
		133	must not enlarge or modify the read buffer, you can only remove data at
		134	the beginning from it.
108		135
109	When an EOF condition is detected then AnyEvent::Handle will first try to	136	When an EOF condition is detected then AnyEvent::Handle will first try to
110	feed all the remaining data to the queued callbacks and C<on_read> before	137	feed all the remaining data to the queued callbacks and C<on_read> before
111	calling the C<on_eof> callback. If no progress can be made, then a fatal	138	calling the C<on_eof> callback. If no progress can be made, then a fatal
112	error will be raised (with C<$!> set to C<EPIPE>).	139	error will be raised (with C<$!> set to C<EPIPE>).
113		140
114	=item on_drain => $cb->()	141	=item on_drain => $cb->($handle)
115		142
116	This sets the callback that is called when the write buffer becomes empty	143	This sets the callback that is called when the write buffer becomes empty
117	(or when the callback is set and the buffer is empty already).	144	(or when the callback is set and the buffer is empty already).
118		145
119	To append to the write buffer, use the C<< ->push_write >> method.	146	To append to the write buffer, use the C<< ->push_write >> method.
120		147
		148	This callback is useful when you don't want to put all of your write data
		149	into the queue at once, for example, when you want to write the contents
		150	of some file to the socket you might not want to read the whole file into
		151	memory and push it into the queue, but instead only read more data from
		152	the file when the write queue becomes empty.
		153
		154	=item timeout => $fractional_seconds
		155
		156	If non-zero, then this enables an "inactivity" timeout: whenever this many
		157	seconds pass without a successful read or write on the underlying file
		158	handle, the C<on_timeout> callback will be invoked (and if that one is
		159	missing, a non-fatal C<ETIMEDOUT> error will be raised).
		160
		161	Note that timeout processing is also active when you currently do not have
		162	any outstanding read or write requests: If you plan to keep the connection
		163	idle then you should disable the timout temporarily or ignore the timeout
		164	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
		165	restart the timeout.
		166
		167	Zero (the default) disables this timeout.
		168
		169	=item on_timeout => $cb->($handle)
		170
		171	Called whenever the inactivity timeout passes. If you return from this
		172	callback, then the timeout will be reset as if some activity had happened,
		173	so this condition is not fatal in any way.
		174
121	=item rbuf_max => <bytes>	175	=item rbuf_max => <bytes>
122		176
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	177	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	178	when the read buffer ever (strictly) exceeds this size. This is useful to
125	avoid denial-of-service attacks.	179	avoid some forms of denial-of-service attacks.
126		180
127	For example, a server accepting connections from untrusted sources should	181	For example, a server accepting connections from untrusted sources should
128	be configured to accept only so-and-so much data that it cannot act on	182	be configured to accept only so-and-so much data that it cannot act on
129	(for example, when expecting a line, an attacker could send an unlimited	183	(for example, when expecting a line, an attacker could send an unlimited
130	amount of data without a callback ever being called as long as the line	184	amount of data without a callback ever being called as long as the line
131	isn't finished).	185	isn't finished).
132		186
		187	=item autocork => <boolean>
		188
		189	When disabled (the default), then C<push_write> will try to immediately
		190	write the data to the handle, if possible. This avoids having to register
		191	a write watcher and wait for the next event loop iteration, but can
		192	be inefficient if you write multiple small chunks (on the wire, this
		193	disadvantage is usually avoided by your kernel's nagle algorithm, see
		194	C<no_delay>, but this option can save costly syscalls).
		195
		196	When enabled, then writes will always be queued till the next event loop
		197	iteration. This is efficient when you do many small writes per iteration,
		198	but less efficient when you do a single write only per iteration (or when
		199	the write buffer often is full). It also increases write latency.
		200
		201	=item no_delay => <boolean>
		202
		203	When doing small writes on sockets, your operating system kernel might
		204	wait a bit for more data before actually sending it out. This is called
		205	the Nagle algorithm, and usually it is beneficial.
		206
		207	In some situations you want as low a delay as possible, which can be
		208	accomplishd by setting this option to a true value.
		209
		210	The default is your opertaing system's default behaviour (most likely
		211	enabled), this option explicitly enables or disables it, if possible.
		212
133	=item read_size => <bytes>	213	=item read_size => <bytes>
134		214
135	The default read block size (the amount of bytes this module will try to read	215	The default read block size (the amount of bytes this module will
136	on each [loop iteration). Default: C<4096>.	216	try to read during each loop iteration, which affects memory
		217	requirements). Default: C<8192>.
137		218
138	=item low_water_mark => <bytes>	219	=item low_water_mark => <bytes>
139		220
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	221	Sets the amount of bytes (default: C<0>) that make up an "empty" write
141	buffer: If the write reaches this size or gets even samller it is	222	buffer: If the write reaches this size or gets even samller it is
142	considered empty.	223	considered empty.
143		224
		225	Sometimes it can be beneficial (for performance reasons) to add data to
		226	the write buffer before it is fully drained, but this is a rare case, as
		227	the operating system kernel usually buffers data as well, so the default
		228	is good in almost all cases.
		229
		230	=item linger => <seconds>
		231
		232	If non-zero (default: C<3600>), then the destructor of the
		233	AnyEvent::Handle object will check whether there is still outstanding
		234	write data and will install a watcher that will write this data to the
		235	socket. No errors will be reported (this mostly matches how the operating
		236	system treats outstanding data at socket close time).
		237
		238	This will not work for partial TLS data that could not be encoded
		239	yet. This data will be lost. Calling the C<stoptls> method in time might
		240	help.
		241
		242	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		243
		244	When this parameter is given, it enables TLS (SSL) mode, that means
		245	AnyEvent will start a TLS handshake as soon as the conenction has been
		246	established and will transparently encrypt/decrypt data afterwards.
		247
		248	TLS mode requires Net::SSLeay to be installed (it will be loaded
		249	automatically when you try to create a TLS handle): this module doesn't
		250	have a dependency on that module, so if your module requires it, you have
		251	to add the dependency yourself.
		252
		253	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		254	C<accept>, and for the TLS client side of a connection, use C<connect>
		255	mode.
		256
		257	You can also provide your own TLS connection object, but you have
		258	to make sure that you call either C<Net::SSLeay::set_connect_state>
		259	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		260	AnyEvent::Handle.
		261
		262	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		263	passing in the wrong integer will lead to certain crash. This most often
		264	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		265	segmentation fault.
		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
144	=back	286	=back
145		287
146	=cut	288	=cut
147		289
148	sub new {	290	sub new {
…		…
152		294
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	295	$self->{fh} or Carp::croak "mandatory argument fh is missing";
154		296
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	297	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		298
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	299	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	300	if $self->{tls};
		301
		302	$self->{_activity} = AnyEvent->now;
		303	$self->_timeout;
		304
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	305	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	306	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
161		307
162	$self->start_read;	308	$self->start_read
		309	if $self->{on_read};
163		310
164	$self	311	$self
165	}	312	}
166		313
167	sub _shutdown {	314	sub _shutdown {
168	my ($self) = @_;	315	my ($self) = @_;
169		316
		317	delete $self->{_tw};
170	delete $self->{rw};	318	delete $self->{_rw};
171	delete $self->{ww};	319	delete $self->{_ww};
172	delete $self->{fh};	320	delete $self->{fh};
173	}
174		321
		322	&_freetls;
		323
		324	delete $self->{on_read};
		325	delete $self->{_queue};
		326	}
		327
175	sub error {	328	sub _error {
176	my ($self) = @_;	329	my ($self, $errno, $fatal) = @_;
177		330
178	{
179	local $!;
180	$self->_shutdown;	331	$self->_shutdown
181	}	332	if $fatal;
		333
		334	$! = $errno;
182		335
183	if ($self->{on_error}) {	336	if ($self->{on_error}) {
184	$self->{on_error}($self);	337	$self->{on_error}($self, $fatal);
185	} else {	338	} elsif ($self->{fh}) {
186	die "AnyEvent::Handle uncaught fatal error: $!";	339	Carp::croak "AnyEvent::Handle uncaught error: $!";
187	}	340	}
188	}	341	}
189		342
190	=item $fh = $handle->fh	343	=item $fh = $handle->fh
191		344
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	345	This method returns the file handle used to create the L<AnyEvent::Handle> object.
193		346
194	=cut	347	=cut
195		348
196	sub fh { $_[0]->{fh} }	349	sub fh { $_[0]{fh} }
197		350
198	=item $handle->on_error ($cb)	351	=item $handle->on_error ($cb)
199		352
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	353	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		354
…		…
213		366
214	sub on_eof {	367	sub on_eof {
215	$_[0]{on_eof} = $_[1];	368	$_[0]{on_eof} = $_[1];
216	}	369	}
217		370
		371	=item $handle->on_timeout ($cb)
		372
		373	Replace the current C<on_timeout> callback, or disables the callback (but
		374	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		375	argument and method.
		376
		377	=cut
		378
		379	sub on_timeout {
		380	$_[0]{on_timeout} = $_[1];
		381	}
		382
		383	=item $handle->autocork ($boolean)
		384
		385	Enables or disables the current autocork behaviour (see C<autocork>
		386	constructor argument). Changes will only take effect on the next write.
		387
		388	=cut
		389
		390	sub autocork {
		391	$_[0]{autocork} = $_[1];
		392	}
		393
		394	=item $handle->no_delay ($boolean)
		395
		396	Enables or disables the C<no_delay> setting (see constructor argument of
		397	the same name for details).
		398
		399	=cut
		400
		401	sub no_delay {
		402	$_[0]{no_delay} = $_[1];
		403
		404	eval {
		405	local $SIG{__DIE__};
		406	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		407	};
		408	}
		409
		410	#############################################################################
		411
		412	=item $handle->timeout ($seconds)
		413
		414	Configures (or disables) the inactivity timeout.
		415
		416	=cut
		417
		418	sub timeout {
		419	my ($self, $timeout) = @_;
		420
		421	$self->{timeout} = $timeout;
		422	$self->_timeout;
		423	}
		424
		425	# reset the timeout watcher, as neccessary
		426	# also check for time-outs
		427	sub _timeout {
		428	my ($self) = @_;
		429
		430	if ($self->{timeout}) {
		431	my $NOW = AnyEvent->now;
		432
		433	# when would the timeout trigger?
		434	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		435
		436	# now or in the past already?
		437	if ($after <= 0) {
		438	$self->{_activity} = $NOW;
		439
		440	if ($self->{on_timeout}) {
		441	$self->{on_timeout}($self);
		442	} else {
		443	$self->_error (&Errno::ETIMEDOUT);
		444	}
		445
		446	# callback could have changed timeout value, optimise
		447	return unless $self->{timeout};
		448
		449	# calculate new after
		450	$after = $self->{timeout};
		451	}
		452
		453	Scalar::Util::weaken $self;
		454	return unless $self; # ->error could have destroyed $self
		455
		456	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		457	delete $self->{_tw};
		458	$self->_timeout;
		459	});
		460	} else {
		461	delete $self->{_tw};
		462	}
		463	}
		464
218	#############################################################################	465	#############################################################################
219		466
220	=back	467	=back
221		468
222	=head2 WRITE QUEUE	469	=head2 WRITE QUEUE
…		…
225	for reading.	472	for reading.
226		473
227	The write queue is very simple: you can add data to its end, and	474	The write queue is very simple: you can add data to its end, and
228	AnyEvent::Handle will automatically try to get rid of it for you.	475	AnyEvent::Handle will automatically try to get rid of it for you.
229		476
230	When data could be writtena nd the write buffer is shorter then the low	477	When data could be written and the write buffer is shorter then the low
231	water mark, the C<on_drain> callback will be invoked.	478	water mark, the C<on_drain> callback will be invoked.
232		479
233	=over 4	480	=over 4
234		481
235	=item $handle->on_drain ($cb)	482	=item $handle->on_drain ($cb)
…		…
243	my ($self, $cb) = @_;	490	my ($self, $cb) = @_;
244		491
245	$self->{on_drain} = $cb;	492	$self->{on_drain} = $cb;
246		493
247	$cb->($self)	494	$cb->($self)
248	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	495	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
249	}	496	}
250		497
251	=item $handle->push_write ($data)	498	=item $handle->push_write ($data)
252		499
253	Queues the given scalar to be written. You can push as much data as you	500	Queues the given scalar to be written. You can push as much data as you
…		…
257	=cut	504	=cut
258		505
259	sub _drain_wbuf {	506	sub _drain_wbuf {
260	my ($self) = @_;	507	my ($self) = @_;
261		508
262	unless ($self->{ww}) {	509	if (!$self->{_ww} && length $self->{wbuf}) {
		510
263	Scalar::Util::weaken $self;	511	Scalar::Util::weaken $self;
		512
264	my $cb = sub {	513	my $cb = sub {
265	my $len = syswrite $self->{fh}, $self->{wbuf};	514	my $len = syswrite $self->{fh}, $self->{wbuf};
266		515
267	if ($len > 0) {	516	if ($len >= 0) {
268	substr $self->{wbuf}, 0, $len, "";	517	substr $self->{wbuf}, 0, $len, "";
269		518
		519	$self->{_activity} = AnyEvent->now;
		520
270	$self->{on_drain}($self)	521	$self->{on_drain}($self)
271	if $self->{low_water_mark} >= length $self->{wbuf}	522	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
272	&& $self->{on_drain};	523	&& $self->{on_drain};
273		524
274	delete $self->{ww} unless length $self->{wbuf};	525	delete $self->{_ww} unless length $self->{wbuf};
275	} elsif ($! != EAGAIN && $! != EINTR) {	526	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
276	$self->error;	527	$self->_error ($!, 1);
277	}	528	}
278	};	529	};
279		530
		531	# try to write data immediately
		532	$cb->() unless $self->{autocork};
		533
		534	# if still data left in wbuf, we need to poll
280	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	535	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
281		536	if length $self->{wbuf};
282	$cb->($self);
283	};	537	};
		538	}
		539
		540	our %WH;
		541
		542	sub register_write_type($$) {
		543	$WH{$_[0]} = $_[1];
284	}	544	}
285		545
286	sub push_write {	546	sub push_write {
287	my $self = shift;	547	my $self = shift;
288		548
		549	if (@_ > 1) {
		550	my $type = shift;
		551
		552	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		553	->($self, @_);
		554	}
		555
289	if ($self->{filter_w}) {	556	if ($self->{tls}) {
290	$self->{filter_w}->(\$_[0]);	557	$self->{_tls_wbuf} .= $_[0];
		558
		559	&_dotls ($self);
291	} else {	560	} else {
292	$self->{wbuf} .= $_[0];	561	$self->{wbuf} .= $_[0];
293	$self->_drain_wbuf;	562	$self->_drain_wbuf;
294	}	563	}
295	}	564	}
296		565
		566	=item $handle->push_write (type => @args)
		567
		568	Instead of formatting your data yourself, you can also let this module do
		569	the job by specifying a type and type-specific arguments.
		570
		571	Predefined types are (if you have ideas for additional types, feel free to
		572	drop by and tell us):
		573
		574	=over 4
		575
		576	=item netstring => $string
		577
		578	Formats the given value as netstring
		579	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		580
		581	=cut
		582
		583	register_write_type netstring => sub {
		584	my ($self, $string) = @_;
		585
		586	(length $string) . ":$string,"
		587	};
		588
		589	=item packstring => $format, $data
		590
		591	An octet string prefixed with an encoded length. The encoding C<$format>
		592	uses the same format as a Perl C<pack> format, but must specify a single
		593	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		594	optional C<!>, C<< < >> or C<< > >> modifier).
		595
		596	=cut
		597
		598	register_write_type packstring => sub {
		599	my ($self, $format, $string) = @_;
		600
		601	pack "$format/a*", $string
		602	};
		603
		604	=item json => $array_or_hashref
		605
		606	Encodes the given hash or array reference into a JSON object. Unless you
		607	provide your own JSON object, this means it will be encoded to JSON text
		608	in UTF-8.
		609
		610	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		611	one end of a handle and read them at the other end without using any
		612	additional framing.
		613
		614	The generated JSON text is guaranteed not to contain any newlines: While
		615	this module doesn't need delimiters after or between JSON texts to be
		616	able to read them, many other languages depend on that.
		617
		618	A simple RPC protocol that interoperates easily with others is to send
		619	JSON arrays (or objects, although arrays are usually the better choice as
		620	they mimic how function argument passing works) and a newline after each
		621	JSON text:
		622
		623	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		624	$handle->push_write ("\012");
		625
		626	An AnyEvent::Handle receiver would simply use the C<json> read type and
		627	rely on the fact that the newline will be skipped as leading whitespace:
		628
		629	$handle->push_read (json => sub { my $array = $_[1]; ... });
		630
		631	Other languages could read single lines terminated by a newline and pass
		632	this line into their JSON decoder of choice.
		633
		634	=cut
		635
		636	register_write_type json => sub {
		637	my ($self, $ref) = @_;
		638
		639	require JSON;
		640
		641	$self->{json} ? $self->{json}->encode ($ref)
		642	: JSON::encode_json ($ref)
		643	};
		644
		645	=item storable => $reference
		646
		647	Freezes the given reference using L<Storable> and writes it to the
		648	handle. Uses the C<nfreeze> format.
		649
		650	=cut
		651
		652	register_write_type storable => sub {
		653	my ($self, $ref) = @_;
		654
		655	require Storable;
		656
		657	pack "w/a*", Storable::nfreeze ($ref)
		658	};
		659
		660	=back
		661
		662	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		663
		664	This function (not method) lets you add your own types to C<push_write>.
		665	Whenever the given C<type> is used, C<push_write> will invoke the code
		666	reference with the handle object and the remaining arguments.
		667
		668	The code reference is supposed to return a single octet string that will
		669	be appended to the write buffer.
		670
		671	Note that this is a function, and all types registered this way will be
		672	global, so try to use unique names.
		673
		674	=cut
		675
297	#############################################################################	676	#############################################################################
298		677
299	=back	678	=back
300		679
301	=head2 READ QUEUE	680	=head2 READ QUEUE
…		…
307	ways, the "simple" way, using only C<on_read> and the "complex" way, using	686	ways, the "simple" way, using only C<on_read> and the "complex" way, using
308	a queue.	687	a queue.
309		688
310	In the simple case, you just install an C<on_read> callback and whenever	689	In the simple case, you just install an C<on_read> callback and whenever
311	new data arrives, it will be called. You can then remove some data (if	690	new data arrives, it will be called. You can then remove some data (if
312	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	691	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
313	or not.	692	leave the data there if you want to accumulate more (e.g. when only a
		693	partial message has been received so far).
314		694
315	In the more complex case, you want to queue multiple callbacks. In this	695	In the more complex case, you want to queue multiple callbacks. In this
316	case, AnyEvent::Handle will call the first queued callback each time new	696	case, AnyEvent::Handle will call the first queued callback each time new
317	data arrives and removes it when it has done its job (see C<push_read>,	697	data arrives (also the first time it is queued) and removes it when it has
318	below).	698	done its job (see C<push_read>, below).
319		699
320	This way you can, for example, push three line-reads, followed by reading	700	This way you can, for example, push three line-reads, followed by reading
321	a chunk of data, and AnyEvent::Handle will execute them in order.	701	a chunk of data, and AnyEvent::Handle will execute them in order.
322		702
323	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	703	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
324	the specified number of bytes which give an XML datagram.	704	the specified number of bytes which give an XML datagram.
325		705
326	# in the default state, expect some header bytes	706	# in the default state, expect some header bytes
327	$handle->on_read (sub {	707	$handle->on_read (sub {
328	# some data is here, now queue the length-header-read (4 octets)	708	# some data is here, now queue the length-header-read (4 octets)
329	shift->unshift_read_chunk (4, sub {	709	shift->unshift_read (chunk => 4, sub {
330	# header arrived, decode	710	# header arrived, decode
331	my $len = unpack "N", $_[1];	711	my $len = unpack "N", $_[1];
332		712
333	# now read the payload	713	# now read the payload
334	shift->unshift_read_chunk ($len, sub {	714	shift->unshift_read (chunk => $len, sub {
335	my $xml = $_[1];	715	my $xml = $_[1];
336	# handle xml	716	# handle xml
337	});	717	});
338	});	718	});
339	});	719	});
340		720
341	Example 2: Implement a client for a protocol that replies either with	721	Example 2: Implement a client for a protocol that replies either with "OK"
342	"OK" and another line or "ERROR" for one request, and 64 bytes for the	722	and another line or "ERROR" for the first request that is sent, and 64
343	second request. Due tot he availability of a full queue, we can just	723	bytes for the second request. Due to the availability of a queue, we can
344	pipeline sending both requests and manipulate the queue as necessary in	724	just pipeline sending both requests and manipulate the queue as necessary
345	the callbacks:	725	in the callbacks.
346		726
347	# request one	727	When the first callback is called and sees an "OK" response, it will
		728	C<unshift> another line-read. This line-read will be queued I<before> the
		729	64-byte chunk callback.
		730
		731	# request one, returns either "OK + extra line" or "ERROR"
348	$handle->push_write ("request 1\015\012");	732	$handle->push_write ("request 1\015\012");
349		733
350	# we expect "ERROR" or "OK" as response, so push a line read	734	# we expect "ERROR" or "OK" as response, so push a line read
351	$handle->push_read_line (sub {	735	$handle->push_read (line => sub {
352	# if we got an "OK", we have to _prepend_ another line,	736	# if we got an "OK", we have to _prepend_ another line,
353	# so it will be read before the second request reads its 64 bytes	737	# so it will be read before the second request reads its 64 bytes
354	# which are already in the queue when this callback is called	738	# which are already in the queue when this callback is called
355	# we don't do this in case we got an error	739	# we don't do this in case we got an error
356	if ($_[1] eq "OK") {	740	if ($_[1] eq "OK") {
357	$_[0]->unshift_read_line (sub {	741	$_[0]->unshift_read (line => sub {
358	my $response = $_[1];	742	my $response = $_[1];
359	...	743	...
360	});	744	});
361	}	745	}
362	});	746	});
363		747
364	# request two	748	# request two, simply returns 64 octets
365	$handle->push_write ("request 2\015\012");	749	$handle->push_write ("request 2\015\012");
366		750
367	# simply read 64 bytes, always	751	# simply read 64 bytes, always
368	$handle->push_read_chunk (64, sub {	752	$handle->push_read (chunk => 64, sub {
369	my $response = $_[1];	753	my $response = $_[1];
370	...	754	...
371	});	755	});
372		756
373	=over 4	757	=over 4
374		758
375	=cut	759	=cut
376		760
377	sub _drain_rbuf {	761	sub _drain_rbuf {
378	my ($self) = @_;	762	my ($self) = @_;
		763
		764	local $self->{_in_drain} = 1;
379		765
380	if (	766	if (
381	defined $self->{rbuf_max}	767	defined $self->{rbuf_max}
382	&& $self->{rbuf_max} < length $self->{rbuf}	768	&& $self->{rbuf_max} < length $self->{rbuf}
383	) {	769	) {
384	$! = &Errno::ENOSPC; return $self->error;	770	$self->_error (&Errno::ENOSPC, 1), return;
385	}	771	}
386		772
387	return if $self->{in_drain};	773	while () {
388	local $self->{in_drain} = 1;	774	# we need to use a separate tls read buffer, as we must not receive data while
		775	# we are draining the buffer, and this can only happen with TLS.
		776	$self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
389		777
390	while (my $len = length $self->{rbuf}) {	778	my $len = length $self->{rbuf};
391	no strict 'refs';	779
392	if (my $cb = shift @{ $self->{queue} }) {	780	if (my $cb = shift @{ $self->{_queue} }) {
393	if (!$cb->($self)) {	781	unless ($cb->($self)) {
394	if ($self->{eof}) {	782	if ($self->{_eof}) {
395	# no progress can be made (not enough data and no data forthcoming)	783	# no progress can be made (not enough data and no data forthcoming)
396	$! = &Errno::EPIPE; return $self->error;	784	$self->_error (&Errno::EPIPE, 1), return;
397	}	785	}
398		786
399	unshift @{ $self->{queue} }, $cb;	787	unshift @{ $self->{_queue} }, $cb;
400	return;	788	last;
401	}	789	}
402	} elsif ($self->{on_read}) {	790	} elsif ($self->{on_read}) {
		791	last unless $len;
		792
403	$self->{on_read}($self);	793	$self->{on_read}($self);
404		794
405	if (	795	if (
406	$self->{eof} # if no further data will arrive
407	&& $len == length $self->{rbuf} # and no data has been consumed	796	$len == length $self->{rbuf} # if no data has been consumed
408	&& !@{ $self->{queue} } # and the queue is still empty	797	&& !@{ $self->{_queue} } # and the queue is still empty
409	&& $self->{on_read} # and we still want to read data	798	&& $self->{on_read} # but we still have on_read
410	) {	799	) {
		800	# no further data will arrive
411	# then no progress can be made	801	# so no progress can be made
412	$! = &Errno::EPIPE; return $self->error;	802	$self->_error (&Errno::EPIPE, 1), return
		803	if $self->{_eof};
		804
		805	last; # more data might arrive
413	}	806	}
414	} else {	807	} else {
415	# read side becomes idle	808	# read side becomes idle
416	delete $self->{rw};	809	delete $self->{_rw} unless $self->{tls};
417	return;	810	last;
418	}	811	}
419	}	812	}
420		813
421	if ($self->{eof}) {	814	if ($self->{_eof}) {
422	$self->_shutdown;	815	if ($self->{on_eof}) {
423	$self->{on_eof}($self)	816	$self->{on_eof}($self)
424	if $self->{on_eof};	817	} else {
		818	$self->_error (0, 1);
		819	}
		820	}
		821
		822	# may need to restart read watcher
		823	unless ($self->{_rw}) {
		824	$self->start_read
		825	if $self->{on_read} || @{ $self->{_queue} };
425	}	826	}
426	}	827	}
427		828
428	=item $handle->on_read ($cb)	829	=item $handle->on_read ($cb)
429		830
…		…
435		836
436	sub on_read {	837	sub on_read {
437	my ($self, $cb) = @_;	838	my ($self, $cb) = @_;
438		839
439	$self->{on_read} = $cb;	840	$self->{on_read} = $cb;
		841	$self->_drain_rbuf if $cb && !$self->{_in_drain};
440	}	842	}
441		843
442	=item $handle->rbuf	844	=item $handle->rbuf
443		845
444	Returns the read buffer (as a modifiable lvalue).	846	Returns the read buffer (as a modifiable lvalue).
445		847
446	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	848	You can access the read buffer directly as the C<< ->{rbuf} >>
447	you want.	849	member, if you want. However, the only operation allowed on the
		850	read buffer (apart from looking at it) is removing data from its
		851	beginning. Otherwise modifying or appending to it is not allowed and will
		852	lead to hard-to-track-down bugs.
448		853
449	NOTE: The read buffer should only be used or modified if the C<on_read>,	854	NOTE: The read buffer should only be used or modified if the C<on_read>,
450	C<push_read> or C<unshift_read> methods are used. The other read methods	855	C<push_read> or C<unshift_read> methods are used. The other read methods
451	automatically manage the read buffer.	856	automatically manage the read buffer.
452		857
…		…
463	Append the given callback to the end of the queue (C<push_read>) or	868	Append the given callback to the end of the queue (C<push_read>) or
464	prepend it (C<unshift_read>).	869	prepend it (C<unshift_read>).
465		870
466	The callback is called each time some additional read data arrives.	871	The callback is called each time some additional read data arrives.
467		872
468	It must check wether enough data is in the read buffer already.	873	It must check whether enough data is in the read buffer already.
469		874
470	If not enough data is available, it must return the empty list or a false	875	If not enough data is available, it must return the empty list or a false
471	value, in which case it will be called repeatedly until enough data is	876	value, in which case it will be called repeatedly until enough data is
472	available (or an error condition is detected).	877	available (or an error condition is detected).
473		878
…		…
475	interested in (which can be none at all) and return a true value. After returning	880	interested in (which can be none at all) and return a true value. After returning
476	true, it will be removed from the queue.	881	true, it will be removed from the queue.
477		882
478	=cut	883	=cut
479		884
		885	our %RH;
		886
		887	sub register_read_type($$) {
		888	$RH{$_[0]} = $_[1];
		889	}
		890
480	sub push_read {	891	sub push_read {
481	my ($self, $cb) = @_;	892	my $self = shift;
		893	my $cb = pop;
482		894
		895	if (@_) {
		896	my $type = shift;
		897
		898	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		899	->($self, $cb, @_);
		900	}
		901
483	push @{ $self->{queue} }, $cb;	902	push @{ $self->{_queue} }, $cb;
484	$self->_drain_rbuf;	903	$self->_drain_rbuf unless $self->{_in_drain};
485	}	904	}
486		905
487	sub unshift_read {	906	sub unshift_read {
488	my ($self, $cb) = @_;	907	my $self = shift;
		908	my $cb = pop;
489		909
		910	if (@_) {
		911	my $type = shift;
		912
		913	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		914	->($self, $cb, @_);
		915	}
		916
		917
490	push @{ $self->{queue} }, $cb;	918	unshift @{ $self->{_queue} }, $cb;
491	$self->_drain_rbuf;	919	$self->_drain_rbuf unless $self->{_in_drain};
492	}	920	}
493		921
494	=item $handle->push_read_chunk ($len, $cb->($self, $data))	922	=item $handle->push_read (type => @args, $cb)
495		923
496	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	924	=item $handle->unshift_read (type => @args, $cb)
497		925
498	Append the given callback to the end of the queue (C<push_read_chunk>) or	926	Instead of providing a callback that parses the data itself you can chose
499	prepend it (C<unshift_read_chunk>).	927	between a number of predefined parsing formats, for chunks of data, lines
		928	etc.
500		929
501	The callback will be called only once C<$len> bytes have been read, and	930	Predefined types are (if you have ideas for additional types, feel free to
502	these C<$len> bytes will be passed to the callback.	931	drop by and tell us):
503		932
504	=cut	933	=over 4
505		934
506	sub _read_chunk($$) {	935	=item chunk => $octets, $cb->($handle, $data)
		936
		937	Invoke the callback only once C<$octets> bytes have been read. Pass the
		938	data read to the callback. The callback will never be called with less
		939	data.
		940
		941	Example: read 2 bytes.
		942
		943	$handle->push_read (chunk => 2, sub {
		944	warn "yay ", unpack "H*", $_[1];
		945	});
		946
		947	=cut
		948
		949	register_read_type chunk => sub {
507	my ($self, $len, $cb) = @_;	950	my ($self, $cb, $len) = @_;
508		951
509	sub {	952	sub {
510	$len <= length $_[0]{rbuf} or return;	953	$len <= length $_[0]{rbuf} or return;
511	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	954	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
512	1	955	1
513	}	956	}
514	}	957	};
515		958
516	sub push_read_chunk {	959	=item line => [$eol, ]$cb->($handle, $line, $eol)
517	$_[0]->push_read (&_read_chunk);
518	}
519
520
521	sub unshift_read_chunk {
522	$_[0]->unshift_read (&_read_chunk);
523	}
524
525	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
526
527	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
528
529	Append the given callback to the end of the queue (C<push_read_line>) or
530	prepend it (C<unshift_read_line>).
531		960
532	The callback will be called only once a full line (including the end of	961	The callback will be called only once a full line (including the end of
533	line marker, C<$eol>) has been read. This line (excluding the end of line	962	line marker, C<$eol>) has been read. This line (excluding the end of line
534	marker) will be passed to the callback as second argument (C<$line>), and	963	marker) will be passed to the callback as second argument (C<$line>), and
535	the end of line marker as the third argument (C<$eol>).	964	the end of line marker as the third argument (C<$eol>).
…		…
546	Partial lines at the end of the stream will never be returned, as they are	975	Partial lines at the end of the stream will never be returned, as they are
547	not marked by the end of line marker.	976	not marked by the end of line marker.
548		977
549	=cut	978	=cut
550		979
551	sub _read_line($$) {	980	register_read_type line => sub {
552	my $self = shift;	981	my ($self, $cb, $eol) = @_;
553	my $cb = pop;
554	my $eol = @_ ? shift : qr|(\015?\012)|;
555	my $pos;
556		982
		983	if (@_ < 3) {
		984	# this is more than twice as fast as the generic code below
		985	sub {
		986	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		987
		988	$cb->($_[0], $1, $2);
		989	1
		990	}
		991	} else {
557	$eol = quotemeta $eol unless ref $eol;	992	$eol = quotemeta $eol unless ref $eol;
558	$eol = qr|^(.*?)($eol)|s;	993	$eol = qr|^(.*?)($eol)|s;
		994
		995	sub {
		996	$_[0]{rbuf} =~ s/$eol// or return;
		997
		998	$cb->($_[0], $1, $2);
		999	1
		1000	}
		1001	}
		1002	};
		1003
		1004	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		1005
		1006	Makes a regex match against the regex object C<$accept> and returns
		1007	everything up to and including the match.
		1008
		1009	Example: read a single line terminated by '\n'.
		1010
		1011	$handle->push_read (regex => qr<\n>, sub { ... });
		1012
		1013	If C<$reject> is given and not undef, then it determines when the data is
		1014	to be rejected: it is matched against the data when the C<$accept> regex
		1015	does not match and generates an C<EBADMSG> error when it matches. This is
		1016	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1017	receive buffer overflow).
		1018
		1019	Example: expect a single decimal number followed by whitespace, reject
		1020	anything else (not the use of an anchor).
		1021
		1022	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1023
		1024	If C<$skip> is given and not C<undef>, then it will be matched against
		1025	the receive buffer when neither C<$accept> nor C<$reject> match,
		1026	and everything preceding and including the match will be accepted
		1027	unconditionally. This is useful to skip large amounts of data that you
		1028	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1029	have to start matching from the beginning. This is purely an optimisation
		1030	and is usually worth only when you expect more than a few kilobytes.
		1031
		1032	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1033	expect the header to be very large (it isn't in practise, but...), we use
		1034	a skip regex to skip initial portions. The skip regex is tricky in that
		1035	it only accepts something not ending in either \015 or \012, as these are
		1036	required for the accept regex.
		1037
		1038	$handle->push_read (regex =>
		1039	qr<\015\012\015\012>,
		1040	undef, # no reject
		1041	qr<^.*[^\015\012]>,
		1042	sub { ... });
		1043
		1044	=cut
		1045
		1046	register_read_type regex => sub {
		1047	my ($self, $cb, $accept, $reject, $skip) = @_;
		1048
		1049	my $data;
		1050	my $rbuf = \$self->{rbuf};
559		1051
560	sub {	1052	sub {
561	$_[0]{rbuf} =~ s/$eol// or return;	1053	# accept
		1054	if ($$rbuf =~ $accept) {
		1055	$data .= substr $$rbuf, 0, $+[0], "";
		1056	$cb->($self, $data);
		1057	return 1;
		1058	}
		1059
		1060	# reject
		1061	if ($reject && $$rbuf =~ $reject) {
		1062	$self->_error (&Errno::EBADMSG);
		1063	}
562		1064
563	$cb->($_[0], $1, $2);	1065	# skip
		1066	if ($skip && $$rbuf =~ $skip) {
		1067	$data .= substr $$rbuf, 0, $+[0], "";
		1068	}
		1069
		1070	()
		1071	}
		1072	};
		1073
		1074	=item netstring => $cb->($handle, $string)
		1075
		1076	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1077
		1078	Throws an error with C<$!> set to EBADMSG on format violations.
		1079
		1080	=cut
		1081
		1082	register_read_type netstring => sub {
		1083	my ($self, $cb) = @_;
		1084
		1085	sub {
		1086	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1087	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1088	$self->_error (&Errno::EBADMSG);
		1089	}
		1090	return;
		1091	}
		1092
		1093	my $len = $1;
		1094
		1095	$self->unshift_read (chunk => $len, sub {
		1096	my $string = $_[1];
		1097	$_[0]->unshift_read (chunk => 1, sub {
		1098	if ($_[1] eq ",") {
		1099	$cb->($_[0], $string);
		1100	} else {
		1101	$self->_error (&Errno::EBADMSG);
		1102	}
		1103	});
		1104	});
		1105
564	1	1106	1
565	}	1107	}
566	}	1108	};
567		1109
568	sub push_read_line {	1110	=item packstring => $format, $cb->($handle, $string)
569	$_[0]->push_read (&_read_line);
570	}
571		1111
572	sub unshift_read_line {	1112	An octet string prefixed with an encoded length. The encoding C<$format>
573	$_[0]->unshift_read (&_read_line);	1113	uses the same format as a Perl C<pack> format, but must specify a single
574	}	1114	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1115	optional C<!>, C<< < >> or C<< > >> modifier).
		1116
		1117	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1118	EPP uses a prefix of C<N> (4 octtes).
		1119
		1120	Example: read a block of data prefixed by its length in BER-encoded
		1121	format (very efficient).
		1122
		1123	$handle->push_read (packstring => "w", sub {
		1124	my ($handle, $data) = @_;
		1125	});
		1126
		1127	=cut
		1128
		1129	register_read_type packstring => sub {
		1130	my ($self, $cb, $format) = @_;
		1131
		1132	sub {
		1133	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1134	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1135	or return;
		1136
		1137	$format = length pack $format, $len;
		1138
		1139	# bypass unshift if we already have the remaining chunk
		1140	if ($format + $len <= length $_[0]{rbuf}) {
		1141	my $data = substr $_[0]{rbuf}, $format, $len;
		1142	substr $_[0]{rbuf}, 0, $format + $len, "";
		1143	$cb->($_[0], $data);
		1144	} else {
		1145	# remove prefix
		1146	substr $_[0]{rbuf}, 0, $format, "";
		1147
		1148	# read remaining chunk
		1149	$_[0]->unshift_read (chunk => $len, $cb);
		1150	}
		1151
		1152	1
		1153	}
		1154	};
		1155
		1156	=item json => $cb->($handle, $hash_or_arrayref)
		1157
		1158	Reads a JSON object or array, decodes it and passes it to the
		1159	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
		1160
		1161	If a C<json> object was passed to the constructor, then that will be used
		1162	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1163
		1164	This read type uses the incremental parser available with JSON version
		1165	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1166	dependency on your own: this module will load the JSON module, but
		1167	AnyEvent does not depend on it itself.
		1168
		1169	Since JSON texts are fully self-delimiting, the C<json> read and write
		1170	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1171	the C<json> write type description, above, for an actual example.
		1172
		1173	=cut
		1174
		1175	register_read_type json => sub {
		1176	my ($self, $cb) = @_;
		1177
		1178	require JSON;
		1179
		1180	my $data;
		1181	my $rbuf = \$self->{rbuf};
		1182
		1183	my $json = $self->{json} ||= JSON->new->utf8;
		1184
		1185	sub {
		1186	my $ref = eval { $json->incr_parse ($self->{rbuf}) };
		1187
		1188	if ($ref) {
		1189	$self->{rbuf} = $json->incr_text;
		1190	$json->incr_text = "";
		1191	$cb->($self, $ref);
		1192
		1193	1
		1194	} elsif ($@) {
		1195	# error case
		1196	$json->incr_skip;
		1197
		1198	$self->{rbuf} = $json->incr_text;
		1199	$json->incr_text = "";
		1200
		1201	$self->_error (&Errno::EBADMSG);
		1202
		1203	()
		1204	} else {
		1205	$self->{rbuf} = "";
		1206
		1207	()
		1208	}
		1209	}
		1210	};
		1211
		1212	=item storable => $cb->($handle, $ref)
		1213
		1214	Deserialises a L<Storable> frozen representation as written by the
		1215	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1216	data).
		1217
		1218	Raises C<EBADMSG> error if the data could not be decoded.
		1219
		1220	=cut
		1221
		1222	register_read_type storable => sub {
		1223	my ($self, $cb) = @_;
		1224
		1225	require Storable;
		1226
		1227	sub {
		1228	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1229	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1230	or return;
		1231
		1232	my $format = length pack "w", $len;
		1233
		1234	# bypass unshift if we already have the remaining chunk
		1235	if ($format + $len <= length $_[0]{rbuf}) {
		1236	my $data = substr $_[0]{rbuf}, $format, $len;
		1237	substr $_[0]{rbuf}, 0, $format + $len, "";
		1238	$cb->($_[0], Storable::thaw ($data));
		1239	} else {
		1240	# remove prefix
		1241	substr $_[0]{rbuf}, 0, $format, "";
		1242
		1243	# read remaining chunk
		1244	$_[0]->unshift_read (chunk => $len, sub {
		1245	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1246	$cb->($_[0], $ref);
		1247	} else {
		1248	$self->_error (&Errno::EBADMSG);
		1249	}
		1250	});
		1251	}
		1252
		1253	1
		1254	}
		1255	};
		1256
		1257	=back
		1258
		1259	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1260
		1261	This function (not method) lets you add your own types to C<push_read>.
		1262
		1263	Whenever the given C<type> is used, C<push_read> will invoke the code
		1264	reference with the handle object, the callback and the remaining
		1265	arguments.
		1266
		1267	The code reference is supposed to return a callback (usually a closure)
		1268	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1269
		1270	It should invoke the passed callback when it is done reading (remember to
		1271	pass C<$handle> as first argument as all other callbacks do that).
		1272
		1273	Note that this is a function, and all types registered this way will be
		1274	global, so try to use unique names.
		1275
		1276	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1277	search for C<register_read_type>)).
575		1278
576	=item $handle->stop_read	1279	=item $handle->stop_read
577		1280
578	=item $handle->start_read	1281	=item $handle->start_read
579		1282
580	In rare cases you actually do not want to read anything form the	1283	In rare cases you actually do not want to read anything from the
581	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1284	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
582	any queued callbacks will be executed then. To start readign again, call	1285	any queued callbacks will be executed then. To start reading again, call
583	C<start_read>.	1286	C<start_read>.
		1287
		1288	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1289	you change the C<on_read> callback or push/unshift a read callback, and it
		1290	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1291	there are any read requests in the queue.
		1292
		1293	These methods will have no effect when in TLS mode (as TLS doesn't support
		1294	half-duplex connections).
584		1295
585	=cut	1296	=cut
586		1297
587	sub stop_read {	1298	sub stop_read {
588	my ($self) = @_;	1299	my ($self) = @_;
589		1300
590	delete $self->{rw};	1301	delete $self->{_rw} unless $self->{tls};
591	}	1302	}
592		1303
593	sub start_read {	1304	sub start_read {
594	my ($self) = @_;	1305	my ($self) = @_;
595		1306
596	unless ($self->{rw} || $self->{eof}) {	1307	unless ($self->{_rw} || $self->{_eof}) {
597	Scalar::Util::weaken $self;	1308	Scalar::Util::weaken $self;
598		1309
599	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1310	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
600	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1311	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
601	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1312	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
602		1313
603	if ($len > 0) {	1314	if ($len > 0) {
604	$self->{filter_r}	1315	$self->{_activity} = AnyEvent->now;
605	? $self->{filter_r}->($rbuf)	1316
606	: $self->_drain_rbuf;	1317	if ($self->{tls}) {
		1318	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1319
		1320	&_dotls ($self);
		1321	} else {
		1322	$self->_drain_rbuf unless $self->{_in_drain};
		1323	}
607		1324
608	} elsif (defined $len) {	1325	} elsif (defined $len) {
609	delete $self->{rw};	1326	delete $self->{_rw};
610	$self->{eof} = 1;	1327	$self->{_eof} = 1;
611	$self->_drain_rbuf;	1328	$self->_drain_rbuf unless $self->{_in_drain};
612		1329
613	} elsif ($! != EAGAIN && $! != EINTR) {	1330	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
614	return $self->error;	1331	return $self->_error ($!, 1);
615	}	1332	}
616	});	1333	});
617	}	1334	}
618	}	1335	}
619		1336
		1337	# poll the write BIO and send the data if applicable
		1338	sub _dotls {
		1339	my ($self) = @_;
		1340
		1341	my $tmp;
		1342
		1343	if (length $self->{_tls_wbuf}) {
		1344	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1345	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1346	}
		1347	}
		1348
		1349	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1350	unless (length $tmp) {
		1351	# let's treat SSL-eof as we treat normal EOF
		1352	delete $self->{_rw};
		1353	$self->{_eof} = 1;
		1354	&_freetls;
		1355	}
		1356
		1357	$self->{_tls_rbuf} .= $tmp;
		1358	$self->_drain_rbuf unless $self->{_in_drain};
		1359	$self->{tls} or return; # tls session might have gone away in callback
		1360	}
		1361
		1362	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1363
		1364	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
		1365	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
		1366	return $self->_error ($!, 1);
		1367	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
		1368	return $self->_error (&Errno::EIO, 1);
		1369	}
		1370
		1371	# all other errors are fine for our purposes
		1372	}
		1373
		1374	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1375	$self->{wbuf} .= $tmp;
		1376	$self->_drain_wbuf;
		1377	}
		1378	}
		1379
		1380	=item $handle->starttls ($tls[, $tls_ctx])
		1381
		1382	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1383	object is created, you can also do that at a later time by calling
		1384	C<starttls>.
		1385
		1386	The first argument is the same as the C<tls> constructor argument (either
		1387	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1388
		1389	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1390	used when AnyEvent::Handle has to create its own TLS connection object.
		1391
		1392	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1393	call and can be used or changed to your liking. Note that the handshake
		1394	might have already started when this function returns.
		1395
		1396	If it an error to start a TLS handshake more than once per
		1397	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1398
		1399	=cut
		1400
		1401	sub starttls {
		1402	my ($self, $ssl, $ctx) = @_;
		1403
		1404	require Net::SSLeay;
		1405
		1406	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
		1407	if $self->{tls};
		1408
		1409	if ($ssl eq "accept") {
		1410	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1411	Net::SSLeay::set_accept_state ($ssl);
		1412	} elsif ($ssl eq "connect") {
		1413	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1414	Net::SSLeay::set_connect_state ($ssl);
		1415	}
		1416
		1417	$self->{tls} = $ssl;
		1418
		1419	# basically, this is deep magic (because SSL_read should have the same issues)
		1420	# but the openssl maintainers basically said: "trust us, it just works".
		1421	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1422	# and mismaintained ssleay-module doesn't even offer them).
		1423	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1424	#
		1425	# in short: this is a mess.
		1426	#
		1427	# note that we do not try to keep the length constant between writes as we are required to do.
		1428	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1429	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1430	# have identity issues in that area.
		1431	Net::SSLeay::CTX_set_mode ($self->{tls},
		1432	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1433	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1434
		1435	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1436	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1437
		1438	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1439
		1440	&_dotls; # need to trigger the initial handshake
		1441	$self->start_read; # make sure we actually do read
		1442	}
		1443
		1444	=item $handle->stoptls
		1445
		1446	Shuts down the SSL connection - this makes a proper EOF handshake by
		1447	sending a close notify to the other side, but since OpenSSL doesn't
		1448	support non-blocking shut downs, it is not possible to re-use the stream
		1449	afterwards.
		1450
		1451	=cut
		1452
		1453	sub stoptls {
		1454	my ($self) = @_;
		1455
		1456	if ($self->{tls}) {
		1457	Net::SSLeay::shutdown ($self->{tls});
		1458
		1459	&_dotls;
		1460
		1461	# we don't give a shit. no, we do, but we can't. no...
		1462	# we, we... have to use openssl :/
		1463	&_freetls;
		1464	}
		1465	}
		1466
		1467	sub _freetls {
		1468	my ($self) = @_;
		1469
		1470	return unless $self->{tls};
		1471
		1472	Net::SSLeay::free (delete $self->{tls});
		1473
		1474	delete @$self{qw(_rbio _wbio _tls_wbuf)};
		1475	}
		1476
		1477	sub DESTROY {
		1478	my $self = shift;
		1479
		1480	&_freetls;
		1481
		1482	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1483
		1484	if ($linger && length $self->{wbuf}) {
		1485	my $fh = delete $self->{fh};
		1486	my $wbuf = delete $self->{wbuf};
		1487
		1488	my @linger;
		1489
		1490	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1491	my $len = syswrite $fh, $wbuf, length $wbuf;
		1492
		1493	if ($len > 0) {
		1494	substr $wbuf, 0, $len, "";
		1495	} else {
		1496	@linger = (); # end
		1497	}
		1498	});
		1499	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1500	@linger = ();
		1501	});
		1502	}
		1503	}
		1504
		1505	=item $handle->destroy
		1506
		1507	Shuts down the handle object as much as possible - this call ensures that
		1508	no further callbacks will be invoked and resources will be freed as much
		1509	as possible. You must not call any methods on the object afterwards.
		1510
		1511	Normally, you can just "forget" any references to an AnyEvent::Handle
		1512	object and it will simply shut down. This works in fatal error and EOF
		1513	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1514	callback, so when you want to destroy the AnyEvent::Handle object from
		1515	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1516	that case.
		1517
		1518	The handle might still linger in the background and write out remaining
		1519	data, as specified by the C<linger> option, however.
		1520
		1521	=cut
		1522
		1523	sub destroy {
		1524	my ($self) = @_;
		1525
		1526	$self->DESTROY;
		1527	%$self = ();
		1528	}
		1529
		1530	=item AnyEvent::Handle::TLS_CTX
		1531
		1532	This function creates and returns the Net::SSLeay::CTX object used by
		1533	default for TLS mode.
		1534
		1535	The context is created like this:
		1536
		1537	Net::SSLeay::load_error_strings;
		1538	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1539	Net::SSLeay::randomize;
		1540
		1541	my $CTX = Net::SSLeay::CTX_new;
		1542
		1543	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1544
		1545	=cut
		1546
		1547	our $TLS_CTX;
		1548
		1549	sub TLS_CTX() {
		1550	$TLS_CTX || do {
		1551	require Net::SSLeay;
		1552
		1553	Net::SSLeay::load_error_strings ();
		1554	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1555	Net::SSLeay::randomize ();
		1556
		1557	$TLS_CTX = Net::SSLeay::CTX_new ();
		1558
		1559	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1560
		1561	$TLS_CTX
		1562	}
		1563	}
		1564
620	=back	1565	=back
621		1566
		1567
		1568	=head1 NONFREQUENTLY ASKED QUESTIONS
		1569
		1570	=over 4
		1571
		1572	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1573	still get further invocations!
		1574
		1575	That's because AnyEvent::Handle keeps a reference to itself when handling
		1576	read or write callbacks.
		1577
		1578	It is only safe to "forget" the reference inside EOF or error callbacks,
		1579	from within all other callbacks, you need to explicitly call the C<<
		1580	->destroy >> method.
		1581
		1582	=item I get different callback invocations in TLS mode/Why can't I pause
		1583	reading?
		1584
		1585	Unlike, say, TCP, TLS connections do not consist of two independent
		1586	communication channels, one for each direction. Or put differently. The
		1587	read and write directions are not independent of each other: you cannot
		1588	write data unless you are also prepared to read, and vice versa.
		1589
		1590	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1591	callback invocations when you are not expecting any read data - the reason
		1592	is that AnyEvent::Handle always reads in TLS mode.
		1593
		1594	During the connection, you have to make sure that you always have a
		1595	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1596	connection (or when you no longer want to use it) you can call the
		1597	C<destroy> method.
		1598
		1599	=item How do I read data until the other side closes the connection?
		1600
		1601	If you just want to read your data into a perl scalar, the easiest way
		1602	to achieve this is by setting an C<on_read> callback that does nothing,
		1603	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1604	will be in C<$_[0]{rbuf}>:
		1605
		1606	$handle->on_read (sub { });
		1607	$handle->on_eof (undef);
		1608	$handle->on_error (sub {
		1609	my $data = delete $_[0]{rbuf};
		1610	undef $handle;
		1611	});
		1612
		1613	The reason to use C<on_error> is that TCP connections, due to latencies
		1614	and packets loss, might get closed quite violently with an error, when in
		1615	fact, all data has been received.
		1616
		1617	It is usually better to use acknowledgements when transferring data,
		1618	to make sure the other side hasn't just died and you got the data
		1619	intact. This is also one reason why so many internet protocols have an
		1620	explicit QUIT command.
		1621
		1622	=item I don't want to destroy the handle too early - how do I wait until
		1623	all data has been written?
		1624
		1625	After writing your last bits of data, set the C<on_drain> callback
		1626	and destroy the handle in there - with the default setting of
		1627	C<low_water_mark> this will be called precisely when all data has been
		1628	written to the socket:
		1629
		1630	$handle->push_write (...);
		1631	$handle->on_drain (sub {
		1632	warn "all data submitted to the kernel\n";
		1633	undef $handle;
		1634	});
		1635
		1636	=back
		1637
		1638
		1639	=head1 SUBCLASSING AnyEvent::Handle
		1640
		1641	In many cases, you might want to subclass AnyEvent::Handle.
		1642
		1643	To make this easier, a given version of AnyEvent::Handle uses these
		1644	conventions:
		1645
		1646	=over 4
		1647
		1648	=item * all constructor arguments become object members.
		1649
		1650	At least initially, when you pass a C<tls>-argument to the constructor it
		1651	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1652	mutated later on (for example C<tls> will hold the TLS connection object).
		1653
		1654	=item * other object member names are prefixed with an C<_>.
		1655
		1656	All object members not explicitly documented (internal use) are prefixed
		1657	with an underscore character, so the remaining non-C<_>-namespace is free
		1658	for use for subclasses.
		1659
		1660	=item * all members not documented here and not prefixed with an underscore
		1661	are free to use in subclasses.
		1662
		1663	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1664	member variables, but thats just life, at least it is documented.
		1665
		1666	=back
		1667
622	=head1 AUTHOR	1668	=head1 AUTHOR
623		1669
624	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1670	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
625		1671
626	=cut	1672	=cut

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