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Revision 1.97 by root, Thu Oct 2 11:07:59 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)	90	=item on_eof => $cb->($handle)
78		91
79	Set the callback to be called on EOF.	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.
80		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
81	While not mandatory, it is highly recommended to set an eof callback,	101	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	102	otherwise you might end up with a closed socket while you are still
83	waiting for data.	103	waiting for data.
84		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
85	=item on_error => $cb->($self)	108	=item on_error => $cb->($handle, $fatal)
86		109
87	This is the fatal error callback, that is called when, well, a fatal error	110	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	111	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	112	connect or a read error.
90		113
91	The object will not be in a usable state when this callback has been	114	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	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>).
93		124
94	On callback entrance, the value of C<$!> contains the operating system	125	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	126	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		127
97	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
98	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
99	die.	130	C<croak>.
100		131
101	=item on_read => $cb->($self)	132	=item on_read => $cb->($handle)
102		133
103	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
104	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).
105		138
106	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 >>
107	method or acces sthe C<$self->{rbuf}> member directly.	140	method or access the C<$handle->{rbuf}> member directly.
108		141
109	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
110	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
111	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
112	error will be raised (with C<$!> set to C<EPIPE>).	145	error will be raised (with C<$!> set to C<EPIPE>).
113		146
114	=item on_drain => $cb->()	147	=item on_drain => $cb->($handle)
115		148
116	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
117	(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).
118		151
119	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.
120		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
121	=item rbuf_max => <bytes>	181	=item rbuf_max => <bytes>
122		182
123	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>)
124	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
125	avoid denial-of-service attacks.	185	avoid some forms of denial-of-service attacks.
126		186
127	For example, a server accepting connections from untrusted sources should	187	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	188	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	189	(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	190	amount of data without a callback ever being called as long as the line
131	isn't finished).	191	isn't finished).
132		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
133	=item read_size => <bytes>	219	=item read_size => <bytes>
134		220
135	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
136	on each [loop iteration). Default: C<4096>.	222	try to read during each loop iteration, which affects memory
		223	requirements). Default: C<8192>.
137		224
138	=item low_water_mark => <bytes>	225	=item low_water_mark => <bytes>
139		226
140	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
141	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
142	considered empty.	229	considered empty.
143		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. Calling the C<stoptls> method in time might
		246	help.
		247
		248	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		249
		250	When this parameter is given, it enables TLS (SSL) mode, that means
		251	AnyEvent will start a TLS handshake as soon as the conenction has been
		252	established and will transparently encrypt/decrypt data afterwards.
		253
		254	TLS mode requires Net::SSLeay to be installed (it will be loaded
		255	automatically when you try to create a TLS handle): this module doesn't
		256	have a dependency on that module, so if your module requires it, you have
		257	to add the dependency yourself.
		258
		259	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		260	C<accept>, and for the TLS client side of a connection, use C<connect>
		261	mode.
		262
		263	You can also provide your own TLS connection object, but you have
		264	to make sure that you call either C<Net::SSLeay::set_connect_state>
		265	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		266	AnyEvent::Handle.
		267
		268	See the C<< ->starttls >> method for when need to start TLS negotiation later.
		269
		270	=item tls_ctx => $ssl_ctx
		271
		272	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
		273	(unless a connection object was specified directly). If this parameter is
		274	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		275
		276	=item json => JSON or JSON::XS object
		277
		278	This is the json coder object used by the C<json> read and write types.
		279
		280	If you don't supply it, then AnyEvent::Handle will create and use a
		281	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		282	texts.
		283
		284	Note that you are responsible to depend on the JSON module if you want to
		285	use this functionality, as AnyEvent does not have a dependency itself.
		286
144	=back	287	=back
145		288
146	=cut	289	=cut
147		290
148	sub new {	291	sub new {
…		…
152		295
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	296	$self->{fh} or Carp::croak "mandatory argument fh is missing";
154		297
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	298	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		299
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	300	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	301	if $self->{tls};
		302
		303	$self->{_activity} = AnyEvent->now;
		304	$self->_timeout;
		305
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	306	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	307	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
161		308
162	$self->start_read;	309	$self->start_read
		310	if $self->{on_read};
163		311
164	$self	312	$self
165	}	313	}
166		314
167	sub _shutdown {	315	sub _shutdown {
168	my ($self) = @_;	316	my ($self) = @_;
169		317
		318	delete $self->{_tw};
170	delete $self->{rw};	319	delete $self->{_rw};
171	delete $self->{ww};	320	delete $self->{_ww};
172	delete $self->{fh};	321	delete $self->{fh};
173	}
174		322
		323	&_freetls;
		324
		325	delete $self->{on_read};
		326	delete $self->{_queue};
		327	}
		328
175	sub error {	329	sub _error {
176	my ($self) = @_;	330	my ($self, $errno, $fatal) = @_;
177		331
178	{
179	local $!;
180	$self->_shutdown;	332	$self->_shutdown
181	}	333	if $fatal;
		334
		335	$! = $errno;
182		336
183	if ($self->{on_error}) {	337	if ($self->{on_error}) {
184	$self->{on_error}($self);	338	$self->{on_error}($self, $fatal);
185	} else {	339	} else {
186	die "AnyEvent::Handle uncaught fatal error: $!";	340	Carp::croak "AnyEvent::Handle uncaught error: $!";
187	}	341	}
188	}	342	}
189		343
190	=item $fh = $handle->fh	344	=item $fh = $handle->fh
191		345
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	346	This method returns the file handle used to create the L<AnyEvent::Handle> object.
193		347
194	=cut	348	=cut
195		349
196	sub fh { $_[0]->{fh} }	350	sub fh { $_[0]{fh} }
197		351
198	=item $handle->on_error ($cb)	352	=item $handle->on_error ($cb)
199		353
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	354	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		355
…		…
213		367
214	sub on_eof {	368	sub on_eof {
215	$_[0]{on_eof} = $_[1];	369	$_[0]{on_eof} = $_[1];
216	}	370	}
217		371
		372	=item $handle->on_timeout ($cb)
		373
		374	Replace the current C<on_timeout> callback, or disables the callback (but
		375	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		376	argument and method.
		377
		378	=cut
		379
		380	sub on_timeout {
		381	$_[0]{on_timeout} = $_[1];
		382	}
		383
		384	=item $handle->autocork ($boolean)
		385
		386	Enables or disables the current autocork behaviour (see C<autocork>
		387	constructor argument).
		388
		389	=cut
		390
		391	=item $handle->no_delay ($boolean)
		392
		393	Enables or disables the C<no_delay> setting (see constructor argument of
		394	the same name for details).
		395
		396	=cut
		397
		398	sub no_delay {
		399	$_[0]{no_delay} = $_[1];
		400
		401	eval {
		402	local $SIG{__DIE__};
		403	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		404	};
		405	}
		406
		407	#############################################################################
		408
		409	=item $handle->timeout ($seconds)
		410
		411	Configures (or disables) the inactivity timeout.
		412
		413	=cut
		414
		415	sub timeout {
		416	my ($self, $timeout) = @_;
		417
		418	$self->{timeout} = $timeout;
		419	$self->_timeout;
		420	}
		421
		422	# reset the timeout watcher, as neccessary
		423	# also check for time-outs
		424	sub _timeout {
		425	my ($self) = @_;
		426
		427	if ($self->{timeout}) {
		428	my $NOW = AnyEvent->now;
		429
		430	# when would the timeout trigger?
		431	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		432
		433	# now or in the past already?
		434	if ($after <= 0) {
		435	$self->{_activity} = $NOW;
		436
		437	if ($self->{on_timeout}) {
		438	$self->{on_timeout}($self);
		439	} else {
		440	$self->_error (&Errno::ETIMEDOUT);
		441	}
		442
		443	# callback could have changed timeout value, optimise
		444	return unless $self->{timeout};
		445
		446	# calculate new after
		447	$after = $self->{timeout};
		448	}
		449
		450	Scalar::Util::weaken $self;
		451	return unless $self; # ->error could have destroyed $self
		452
		453	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		454	delete $self->{_tw};
		455	$self->_timeout;
		456	});
		457	} else {
		458	delete $self->{_tw};
		459	}
		460	}
		461
218	#############################################################################	462	#############################################################################
219		463
220	=back	464	=back
221		465
222	=head2 WRITE QUEUE	466	=head2 WRITE QUEUE
…		…
225	for reading.	469	for reading.
226		470
227	The write queue is very simple: you can add data to its end, and	471	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.	472	AnyEvent::Handle will automatically try to get rid of it for you.
229		473
230	When data could be writtena nd the write buffer is shorter then the low	474	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.	475	water mark, the C<on_drain> callback will be invoked.
232		476
233	=over 4	477	=over 4
234		478
235	=item $handle->on_drain ($cb)	479	=item $handle->on_drain ($cb)
…		…
243	my ($self, $cb) = @_;	487	my ($self, $cb) = @_;
244		488
245	$self->{on_drain} = $cb;	489	$self->{on_drain} = $cb;
246		490
247	$cb->($self)	491	$cb->($self)
248	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	492	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
249	}	493	}
250		494
251	=item $handle->push_write ($data)	495	=item $handle->push_write ($data)
252		496
253	Queues the given scalar to be written. You can push as much data as you	497	Queues the given scalar to be written. You can push as much data as you
254	want (only limited by the available memory), as C<AnyEvent::Handle>	498	want (only limited by the available memory), as C<AnyEvent::Handle>
255	buffers it independently of the kernel.	499	buffers it independently of the kernel.
256		500
257	=cut	501	=cut
258		502
259	sub push_write {	503	sub _drain_wbuf {
260	my ($self, $data) = @_;	504	my ($self) = @_;
261		505
262	$self->{wbuf} .= $data;	506	if (!$self->{_ww} && length $self->{wbuf}) {
263		507
264	unless ($self->{ww}) {
265	Scalar::Util::weaken $self;	508	Scalar::Util::weaken $self;
		509
266	my $cb = sub {	510	my $cb = sub {
267	my $len = syswrite $self->{fh}, $self->{wbuf};	511	my $len = syswrite $self->{fh}, $self->{wbuf};
268		512
269	if ($len > 0) {	513	if ($len >= 0) {
270	substr $self->{wbuf}, 0, $len, "";	514	substr $self->{wbuf}, 0, $len, "";
271		515
		516	$self->{_activity} = AnyEvent->now;
272		517
273	$self->{on_drain}($self)	518	$self->{on_drain}($self)
274	if $self->{low_water_mark} >= length $self->{wbuf}	519	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
275	&& $self->{on_drain};	520	&& $self->{on_drain};
276		521
277	delete $self->{ww} unless length $self->{wbuf};	522	delete $self->{_ww} unless length $self->{wbuf};
278	} elsif ($! != EAGAIN && $! != EINTR) {	523	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
279	$self->error;	524	$self->_error ($!, 1);
280	}	525	}
281	};	526	};
282		527
		528	# try to write data immediately
		529	$cb->() unless $self->{autocork};
		530
		531	# if still data left in wbuf, we need to poll
283	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	532	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
284		533	if length $self->{wbuf};
285	$cb->($self);
286	};	534	};
287	}	535	}
		536
		537	our %WH;
		538
		539	sub register_write_type($$) {
		540	$WH{$_[0]} = $_[1];
		541	}
		542
		543	sub push_write {
		544	my $self = shift;
		545
		546	if (@_ > 1) {
		547	my $type = shift;
		548
		549	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		550	->($self, @_);
		551	}
		552
		553	if ($self->{tls}) {
		554	$self->{_tls_wbuf} .= $_[0];
		555
		556	&_dotls ($self);
		557	} else {
		558	$self->{wbuf} .= $_[0];
		559	$self->_drain_wbuf;
		560	}
		561	}
		562
		563	=item $handle->push_write (type => @args)
		564
		565	Instead of formatting your data yourself, you can also let this module do
		566	the job by specifying a type and type-specific arguments.
		567
		568	Predefined types are (if you have ideas for additional types, feel free to
		569	drop by and tell us):
		570
		571	=over 4
		572
		573	=item netstring => $string
		574
		575	Formats the given value as netstring
		576	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		577
		578	=cut
		579
		580	register_write_type netstring => sub {
		581	my ($self, $string) = @_;
		582
		583	(length $string) . ":$string,"
		584	};
		585
		586	=item packstring => $format, $data
		587
		588	An octet string prefixed with an encoded length. The encoding C<$format>
		589	uses the same format as a Perl C<pack> format, but must specify a single
		590	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		591	optional C<!>, C<< < >> or C<< > >> modifier).
		592
		593	=cut
		594
		595	register_write_type packstring => sub {
		596	my ($self, $format, $string) = @_;
		597
		598	pack "$format/a*", $string
		599	};
		600
		601	=item json => $array_or_hashref
		602
		603	Encodes the given hash or array reference into a JSON object. Unless you
		604	provide your own JSON object, this means it will be encoded to JSON text
		605	in UTF-8.
		606
		607	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		608	one end of a handle and read them at the other end without using any
		609	additional framing.
		610
		611	The generated JSON text is guaranteed not to contain any newlines: While
		612	this module doesn't need delimiters after or between JSON texts to be
		613	able to read them, many other languages depend on that.
		614
		615	A simple RPC protocol that interoperates easily with others is to send
		616	JSON arrays (or objects, although arrays are usually the better choice as
		617	they mimic how function argument passing works) and a newline after each
		618	JSON text:
		619
		620	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		621	$handle->push_write ("\012");
		622
		623	An AnyEvent::Handle receiver would simply use the C<json> read type and
		624	rely on the fact that the newline will be skipped as leading whitespace:
		625
		626	$handle->push_read (json => sub { my $array = $_[1]; ... });
		627
		628	Other languages could read single lines terminated by a newline and pass
		629	this line into their JSON decoder of choice.
		630
		631	=cut
		632
		633	register_write_type json => sub {
		634	my ($self, $ref) = @_;
		635
		636	require JSON;
		637
		638	$self->{json} ? $self->{json}->encode ($ref)
		639	: JSON::encode_json ($ref)
		640	};
		641
		642	=item storable => $reference
		643
		644	Freezes the given reference using L<Storable> and writes it to the
		645	handle. Uses the C<nfreeze> format.
		646
		647	=cut
		648
		649	register_write_type storable => sub {
		650	my ($self, $ref) = @_;
		651
		652	require Storable;
		653
		654	pack "w/a*", Storable::nfreeze ($ref)
		655	};
		656
		657	=back
		658
		659	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		660
		661	This function (not method) lets you add your own types to C<push_write>.
		662	Whenever the given C<type> is used, C<push_write> will invoke the code
		663	reference with the handle object and the remaining arguments.
		664
		665	The code reference is supposed to return a single octet string that will
		666	be appended to the write buffer.
		667
		668	Note that this is a function, and all types registered this way will be
		669	global, so try to use unique names.
		670
		671	=cut
288		672
289	#############################################################################	673	#############################################################################
290		674
291	=back	675	=back
292		676
…		…
299	ways, the "simple" way, using only C<on_read> and the "complex" way, using	683	ways, the "simple" way, using only C<on_read> and the "complex" way, using
300	a queue.	684	a queue.
301		685
302	In the simple case, you just install an C<on_read> callback and whenever	686	In the simple case, you just install an C<on_read> callback and whenever
303	new data arrives, it will be called. You can then remove some data (if	687	new data arrives, it will be called. You can then remove some data (if
304	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	688	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
305	or not.	689	leave the data there if you want to accumulate more (e.g. when only a
		690	partial message has been received so far).
306		691
307	In the more complex case, you want to queue multiple callbacks. In this	692	In the more complex case, you want to queue multiple callbacks. In this
308	case, AnyEvent::Handle will call the first queued callback each time new	693	case, AnyEvent::Handle will call the first queued callback each time new
309	data arrives and removes it when it has done its job (see C<push_read>,	694	data arrives (also the first time it is queued) and removes it when it has
310	below).	695	done its job (see C<push_read>, below).
311		696
312	This way you can, for example, push three line-reads, followed by reading	697	This way you can, for example, push three line-reads, followed by reading
313	a chunk of data, and AnyEvent::Handle will execute them in order.	698	a chunk of data, and AnyEvent::Handle will execute them in order.
314		699
315	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	700	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
316	the specified number of bytes which give an XML datagram.	701	the specified number of bytes which give an XML datagram.
317		702
318	# in the default state, expect some header bytes	703	# in the default state, expect some header bytes
319	$handle->on_read (sub {	704	$handle->on_read (sub {
320	# some data is here, now queue the length-header-read (4 octets)	705	# some data is here, now queue the length-header-read (4 octets)
321	shift->unshift_read_chunk (4, sub {	706	shift->unshift_read (chunk => 4, sub {
322	# header arrived, decode	707	# header arrived, decode
323	my $len = unpack "N", $_[1];	708	my $len = unpack "N", $_[1];
324		709
325	# now read the payload	710	# now read the payload
326	shift->unshift_read_chunk ($len, sub {	711	shift->unshift_read (chunk => $len, sub {
327	my $xml = $_[1];	712	my $xml = $_[1];
328	# handle xml	713	# handle xml
329	});	714	});
330	});	715	});
331	});	716	});
332		717
333	Example 2: Implement a client for a protocol that replies either with	718	Example 2: Implement a client for a protocol that replies either with "OK"
334	"OK" and another line or "ERROR" for one request, and 64 bytes for the	719	and another line or "ERROR" for the first request that is sent, and 64
335	second request. Due tot he availability of a full queue, we can just	720	bytes for the second request. Due to the availability of a queue, we can
336	pipeline sending both requests and manipulate the queue as necessary in	721	just pipeline sending both requests and manipulate the queue as necessary
337	the callbacks:	722	in the callbacks.
338		723
339	# request one	724	When the first callback is called and sees an "OK" response, it will
		725	C<unshift> another line-read. This line-read will be queued I<before> the
		726	64-byte chunk callback.
		727
		728	# request one, returns either "OK + extra line" or "ERROR"
340	$handle->push_write ("request 1\015\012");	729	$handle->push_write ("request 1\015\012");
341		730
342	# we expect "ERROR" or "OK" as response, so push a line read	731	# we expect "ERROR" or "OK" as response, so push a line read
343	$handle->push_read_line (sub {	732	$handle->push_read (line => sub {
344	# if we got an "OK", we have to _prepend_ another line,	733	# if we got an "OK", we have to _prepend_ another line,
345	# so it will be read before the second request reads its 64 bytes	734	# so it will be read before the second request reads its 64 bytes
346	# which are already in the queue when this callback is called	735	# which are already in the queue when this callback is called
347	# we don't do this in case we got an error	736	# we don't do this in case we got an error
348	if ($_[1] eq "OK") {	737	if ($_[1] eq "OK") {
349	$_[0]->unshift_read_line (sub {	738	$_[0]->unshift_read (line => sub {
350	my $response = $_[1];	739	my $response = $_[1];
351	...	740	...
352	});	741	});
353	}	742	}
354	});	743	});
355		744
356	# request two	745	# request two, simply returns 64 octets
357	$handle->push_write ("request 2\015\012");	746	$handle->push_write ("request 2\015\012");
358		747
359	# simply read 64 bytes, always	748	# simply read 64 bytes, always
360	$handle->push_read_chunk (64, sub {	749	$handle->push_read (chunk => 64, sub {
361	my $response = $_[1];	750	my $response = $_[1];
362	...	751	...
363	});	752	});
364		753
365	=over 4	754	=over 4
…		…
367	=cut	756	=cut
368		757
369	sub _drain_rbuf {	758	sub _drain_rbuf {
370	my ($self) = @_;	759	my ($self) = @_;
371		760
372	return if $self->{in_drain};
373	local $self->{in_drain} = 1;	761	local $self->{_in_drain} = 1;
374		762
		763	if (
		764	defined $self->{rbuf_max}
		765	&& $self->{rbuf_max} < length $self->{rbuf}
		766	) {
		767	$self->_error (&Errno::ENOSPC, 1), return;
		768	}
		769
		770	while () {
375	while (my $len = length $self->{rbuf}) {	771	my $len = length $self->{rbuf};
376	no strict 'refs';	772
377	if (my $cb = shift @{ $self->{queue} }) {	773	if (my $cb = shift @{ $self->{_queue} }) {
378	if (!$cb->($self)) {	774	unless ($cb->($self)) {
379	if ($self->{eof}) {	775	if ($self->{_eof}) {
380	# no progress can be made (not enough data and no data forthcoming)	776	# no progress can be made (not enough data and no data forthcoming)
381	$! = &Errno::EPIPE; return $self->error;	777	$self->_error (&Errno::EPIPE, 1), return;
382	}	778	}
383		779
384	unshift @{ $self->{queue} }, $cb;	780	unshift @{ $self->{_queue} }, $cb;
385	return;	781	last;
386	}	782	}
387	} elsif ($self->{on_read}) {	783	} elsif ($self->{on_read}) {
		784	last unless $len;
		785
388	$self->{on_read}($self);	786	$self->{on_read}($self);
389		787
390	if (	788	if (
391	$self->{eof} # if no further data will arrive
392	&& $len == length $self->{rbuf} # and no data has been consumed	789	$len == length $self->{rbuf} # if no data has been consumed
393	&& !@{ $self->{queue} } # and the queue is still empty	790	&& !@{ $self->{_queue} } # and the queue is still empty
394	&& $self->{on_read} # and we still want to read data	791	&& $self->{on_read} # but we still have on_read
395	) {	792	) {
		793	# no further data will arrive
396	# then no progress can be made	794	# so no progress can be made
397	$! = &Errno::EPIPE; return $self->error;	795	$self->_error (&Errno::EPIPE, 1), return
		796	if $self->{_eof};
		797
		798	last; # more data might arrive
398	}	799	}
399	} else {	800	} else {
400	# read side becomes idle	801	# read side becomes idle
401	delete $self->{rw};	802	delete $self->{_rw} unless $self->{tls};
402	return;	803	last;
403	}	804	}
404	}	805	}
405		806
406	if ($self->{eof}) {	807	if ($self->{_eof}) {
407	$self->_shutdown;	808	if ($self->{on_eof}) {
408	$self->{on_eof}($self)	809	$self->{on_eof}($self)
409	if $self->{on_eof};	810	} else {
		811	$self->_error (0, 1);
		812	}
		813	}
		814
		815	# may need to restart read watcher
		816	unless ($self->{_rw}) {
		817	$self->start_read
		818	if $self->{on_read} || @{ $self->{_queue} };
410	}	819	}
411	}	820	}
412		821
413	=item $handle->on_read ($cb)	822	=item $handle->on_read ($cb)
414		823
…		…
420		829
421	sub on_read {	830	sub on_read {
422	my ($self, $cb) = @_;	831	my ($self, $cb) = @_;
423		832
424	$self->{on_read} = $cb;	833	$self->{on_read} = $cb;
		834	$self->_drain_rbuf if $cb && !$self->{_in_drain};
425	}	835	}
426		836
427	=item $handle->rbuf	837	=item $handle->rbuf
428		838
429	Returns the read buffer (as a modifiable lvalue).	839	Returns the read buffer (as a modifiable lvalue).
…		…
448	Append the given callback to the end of the queue (C<push_read>) or	858	Append the given callback to the end of the queue (C<push_read>) or
449	prepend it (C<unshift_read>).	859	prepend it (C<unshift_read>).
450		860
451	The callback is called each time some additional read data arrives.	861	The callback is called each time some additional read data arrives.
452		862
453	It must check wether enough data is in the read buffer already.	863	It must check whether enough data is in the read buffer already.
454		864
455	If not enough data is available, it must return the empty list or a false	865	If not enough data is available, it must return the empty list or a false
456	value, in which case it will be called repeatedly until enough data is	866	value, in which case it will be called repeatedly until enough data is
457	available (or an error condition is detected).	867	available (or an error condition is detected).
458		868
…		…
460	interested in (which can be none at all) and return a true value. After returning	870	interested in (which can be none at all) and return a true value. After returning
461	true, it will be removed from the queue.	871	true, it will be removed from the queue.
462		872
463	=cut	873	=cut
464		874
		875	our %RH;
		876
		877	sub register_read_type($$) {
		878	$RH{$_[0]} = $_[1];
		879	}
		880
465	sub push_read {	881	sub push_read {
466	my ($self, $cb) = @_;	882	my $self = shift;
		883	my $cb = pop;
467		884
		885	if (@_) {
		886	my $type = shift;
		887
		888	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		889	->($self, $cb, @_);
		890	}
		891
468	push @{ $self->{queue} }, $cb;	892	push @{ $self->{_queue} }, $cb;
469	$self->_drain_rbuf;	893	$self->_drain_rbuf unless $self->{_in_drain};
470	}	894	}
471		895
472	sub unshift_read {	896	sub unshift_read {
473	my ($self, $cb) = @_;	897	my $self = shift;
		898	my $cb = pop;
474		899
		900	if (@_) {
		901	my $type = shift;
		902
		903	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		904	->($self, $cb, @_);
		905	}
		906
		907
475	push @{ $self->{queue} }, $cb;	908	unshift @{ $self->{_queue} }, $cb;
476	$self->_drain_rbuf;	909	$self->_drain_rbuf unless $self->{_in_drain};
477	}	910	}
478		911
479	=item $handle->push_read_chunk ($len, $cb->($self, $data))	912	=item $handle->push_read (type => @args, $cb)
480		913
481	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	914	=item $handle->unshift_read (type => @args, $cb)
482		915
483	Append the given callback to the end of the queue (C<push_read_chunk>) or	916	Instead of providing a callback that parses the data itself you can chose
484	prepend it (C<unshift_read_chunk>).	917	between a number of predefined parsing formats, for chunks of data, lines
		918	etc.
485		919
486	The callback will be called only once C<$len> bytes have been read, and	920	Predefined types are (if you have ideas for additional types, feel free to
487	these C<$len> bytes will be passed to the callback.	921	drop by and tell us):
488		922
489	=cut	923	=over 4
490		924
491	sub _read_chunk($$) {	925	=item chunk => $octets, $cb->($handle, $data)
		926
		927	Invoke the callback only once C<$octets> bytes have been read. Pass the
		928	data read to the callback. The callback will never be called with less
		929	data.
		930
		931	Example: read 2 bytes.
		932
		933	$handle->push_read (chunk => 2, sub {
		934	warn "yay ", unpack "H*", $_[1];
		935	});
		936
		937	=cut
		938
		939	register_read_type chunk => sub {
492	my ($self, $len, $cb) = @_;	940	my ($self, $cb, $len) = @_;
493		941
494	sub {	942	sub {
495	$len <= length $_[0]{rbuf} or return;	943	$len <= length $_[0]{rbuf} or return;
496	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	944	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
497	1	945	1
498	}	946	}
499	}	947	};
500		948
501	sub push_read_chunk {	949	=item line => [$eol, ]$cb->($handle, $line, $eol)
502	$_[0]->push_read (&_read_chunk);
503	}
504
505
506	sub unshift_read_chunk {
507	$_[0]->unshift_read (&_read_chunk);
508	}
509
510	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
511
512	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
513
514	Append the given callback to the end of the queue (C<push_read_line>) or
515	prepend it (C<unshift_read_line>).
516		950
517	The callback will be called only once a full line (including the end of	951	The callback will be called only once a full line (including the end of
518	line marker, C<$eol>) has been read. This line (excluding the end of line	952	line marker, C<$eol>) has been read. This line (excluding the end of line
519	marker) will be passed to the callback as second argument (C<$line>), and	953	marker) will be passed to the callback as second argument (C<$line>), and
520	the end of line marker as the third argument (C<$eol>).	954	the end of line marker as the third argument (C<$eol>).
…		…
531	Partial lines at the end of the stream will never be returned, as they are	965	Partial lines at the end of the stream will never be returned, as they are
532	not marked by the end of line marker.	966	not marked by the end of line marker.
533		967
534	=cut	968	=cut
535		969
536	sub _read_line($$) {	970	register_read_type line => sub {
537	my $self = shift;	971	my ($self, $cb, $eol) = @_;
538	my $cb = pop;
539	my $eol = @_ ? shift : qr|(\015?\012)|;
540	my $pos;
541		972
		973	if (@_ < 3) {
		974	# this is more than twice as fast as the generic code below
		975	sub {
		976	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		977
		978	$cb->($_[0], $1, $2);
		979	1
		980	}
		981	} else {
542	$eol = quotemeta $eol unless ref $eol;	982	$eol = quotemeta $eol unless ref $eol;
543	$eol = qr|^(.*?)($eol)|s;	983	$eol = qr|^(.*?)($eol)|s;
		984
		985	sub {
		986	$_[0]{rbuf} =~ s/$eol// or return;
		987
		988	$cb->($_[0], $1, $2);
		989	1
		990	}
		991	}
		992	};
		993
		994	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		995
		996	Makes a regex match against the regex object C<$accept> and returns
		997	everything up to and including the match.
		998
		999	Example: read a single line terminated by '\n'.
		1000
		1001	$handle->push_read (regex => qr<\n>, sub { ... });
		1002
		1003	If C<$reject> is given and not undef, then it determines when the data is
		1004	to be rejected: it is matched against the data when the C<$accept> regex
		1005	does not match and generates an C<EBADMSG> error when it matches. This is
		1006	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1007	receive buffer overflow).
		1008
		1009	Example: expect a single decimal number followed by whitespace, reject
		1010	anything else (not the use of an anchor).
		1011
		1012	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1013
		1014	If C<$skip> is given and not C<undef>, then it will be matched against
		1015	the receive buffer when neither C<$accept> nor C<$reject> match,
		1016	and everything preceding and including the match will be accepted
		1017	unconditionally. This is useful to skip large amounts of data that you
		1018	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1019	have to start matching from the beginning. This is purely an optimisation
		1020	and is usually worth only when you expect more than a few kilobytes.
		1021
		1022	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1023	expect the header to be very large (it isn't in practise, but...), we use
		1024	a skip regex to skip initial portions. The skip regex is tricky in that
		1025	it only accepts something not ending in either \015 or \012, as these are
		1026	required for the accept regex.
		1027
		1028	$handle->push_read (regex =>
		1029	qr<\015\012\015\012>,
		1030	undef, # no reject
		1031	qr<^.*[^\015\012]>,
		1032	sub { ... });
		1033
		1034	=cut
		1035
		1036	register_read_type regex => sub {
		1037	my ($self, $cb, $accept, $reject, $skip) = @_;
		1038
		1039	my $data;
		1040	my $rbuf = \$self->{rbuf};
544		1041
545	sub {	1042	sub {
546	$_[0]{rbuf} =~ s/$eol// or return;	1043	# accept
		1044	if ($$rbuf =~ $accept) {
		1045	$data .= substr $$rbuf, 0, $+[0], "";
		1046	$cb->($self, $data);
		1047	return 1;
		1048	}
		1049
		1050	# reject
		1051	if ($reject && $$rbuf =~ $reject) {
		1052	$self->_error (&Errno::EBADMSG);
		1053	}
547		1054
548	$cb->($_[0], $1, $2);	1055	# skip
		1056	if ($skip && $$rbuf =~ $skip) {
		1057	$data .= substr $$rbuf, 0, $+[0], "";
		1058	}
		1059
		1060	()
		1061	}
		1062	};
		1063
		1064	=item netstring => $cb->($handle, $string)
		1065
		1066	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1067
		1068	Throws an error with C<$!> set to EBADMSG on format violations.
		1069
		1070	=cut
		1071
		1072	register_read_type netstring => sub {
		1073	my ($self, $cb) = @_;
		1074
		1075	sub {
		1076	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1077	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1078	$self->_error (&Errno::EBADMSG);
		1079	}
		1080	return;
		1081	}
		1082
		1083	my $len = $1;
		1084
		1085	$self->unshift_read (chunk => $len, sub {
		1086	my $string = $_[1];
		1087	$_[0]->unshift_read (chunk => 1, sub {
		1088	if ($_[1] eq ",") {
		1089	$cb->($_[0], $string);
		1090	} else {
		1091	$self->_error (&Errno::EBADMSG);
		1092	}
		1093	});
		1094	});
		1095
549	1	1096	1
550	}	1097	}
551	}	1098	};
552		1099
553	sub push_read_line {	1100	=item packstring => $format, $cb->($handle, $string)
554	$_[0]->push_read (&_read_line);
555	}
556		1101
557	sub unshift_read_line {	1102	An octet string prefixed with an encoded length. The encoding C<$format>
558	$_[0]->unshift_read (&_read_line);	1103	uses the same format as a Perl C<pack> format, but must specify a single
559	}	1104	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1105	optional C<!>, C<< < >> or C<< > >> modifier).
		1106
		1107	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1108	EPP uses a prefix of C<N> (4 octtes).
		1109
		1110	Example: read a block of data prefixed by its length in BER-encoded
		1111	format (very efficient).
		1112
		1113	$handle->push_read (packstring => "w", sub {
		1114	my ($handle, $data) = @_;
		1115	});
		1116
		1117	=cut
		1118
		1119	register_read_type packstring => sub {
		1120	my ($self, $cb, $format) = @_;
		1121
		1122	sub {
		1123	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1124	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1125	or return;
		1126
		1127	$format = length pack $format, $len;
		1128
		1129	# bypass unshift if we already have the remaining chunk
		1130	if ($format + $len <= length $_[0]{rbuf}) {
		1131	my $data = substr $_[0]{rbuf}, $format, $len;
		1132	substr $_[0]{rbuf}, 0, $format + $len, "";
		1133	$cb->($_[0], $data);
		1134	} else {
		1135	# remove prefix
		1136	substr $_[0]{rbuf}, 0, $format, "";
		1137
		1138	# read remaining chunk
		1139	$_[0]->unshift_read (chunk => $len, $cb);
		1140	}
		1141
		1142	1
		1143	}
		1144	};
		1145
		1146	=item json => $cb->($handle, $hash_or_arrayref)
		1147
		1148	Reads a JSON object or array, decodes it and passes it to the callback.
		1149
		1150	If a C<json> object was passed to the constructor, then that will be used
		1151	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1152
		1153	This read type uses the incremental parser available with JSON version
		1154	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1155	dependency on your own: this module will load the JSON module, but
		1156	AnyEvent does not depend on it itself.
		1157
		1158	Since JSON texts are fully self-delimiting, the C<json> read and write
		1159	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1160	the C<json> write type description, above, for an actual example.
		1161
		1162	=cut
		1163
		1164	register_read_type json => sub {
		1165	my ($self, $cb) = @_;
		1166
		1167	require JSON;
		1168
		1169	my $data;
		1170	my $rbuf = \$self->{rbuf};
		1171
		1172	my $json = $self->{json} ||= JSON->new->utf8;
		1173
		1174	sub {
		1175	my $ref = $json->incr_parse ($self->{rbuf});
		1176
		1177	if ($ref) {
		1178	$self->{rbuf} = $json->incr_text;
		1179	$json->incr_text = "";
		1180	$cb->($self, $ref);
		1181
		1182	1
		1183	} else {
		1184	$self->{rbuf} = "";
		1185	()
		1186	}
		1187	}
		1188	};
		1189
		1190	=item storable => $cb->($handle, $ref)
		1191
		1192	Deserialises a L<Storable> frozen representation as written by the
		1193	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1194	data).
		1195
		1196	Raises C<EBADMSG> error if the data could not be decoded.
		1197
		1198	=cut
		1199
		1200	register_read_type storable => sub {
		1201	my ($self, $cb) = @_;
		1202
		1203	require Storable;
		1204
		1205	sub {
		1206	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1207	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1208	or return;
		1209
		1210	my $format = length pack "w", $len;
		1211
		1212	# bypass unshift if we already have the remaining chunk
		1213	if ($format + $len <= length $_[0]{rbuf}) {
		1214	my $data = substr $_[0]{rbuf}, $format, $len;
		1215	substr $_[0]{rbuf}, 0, $format + $len, "";
		1216	$cb->($_[0], Storable::thaw ($data));
		1217	} else {
		1218	# remove prefix
		1219	substr $_[0]{rbuf}, 0, $format, "";
		1220
		1221	# read remaining chunk
		1222	$_[0]->unshift_read (chunk => $len, sub {
		1223	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1224	$cb->($_[0], $ref);
		1225	} else {
		1226	$self->_error (&Errno::EBADMSG);
		1227	}
		1228	});
		1229	}
		1230
		1231	1
		1232	}
		1233	};
		1234
		1235	=back
		1236
		1237	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1238
		1239	This function (not method) lets you add your own types to C<push_read>.
		1240
		1241	Whenever the given C<type> is used, C<push_read> will invoke the code
		1242	reference with the handle object, the callback and the remaining
		1243	arguments.
		1244
		1245	The code reference is supposed to return a callback (usually a closure)
		1246	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1247
		1248	It should invoke the passed callback when it is done reading (remember to
		1249	pass C<$handle> as first argument as all other callbacks do that).
		1250
		1251	Note that this is a function, and all types registered this way will be
		1252	global, so try to use unique names.
		1253
		1254	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1255	search for C<register_read_type>)).
560		1256
561	=item $handle->stop_read	1257	=item $handle->stop_read
562		1258
563	=item $handle->start_read	1259	=item $handle->start_read
564		1260
565	In rare cases you actually do not want to read anything form the	1261	In rare cases you actually do not want to read anything from the
566	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1262	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
567	any queued callbacks will be executed then. To start readign again, call	1263	any queued callbacks will be executed then. To start reading again, call
568	C<start_read>.	1264	C<start_read>.
		1265
		1266	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1267	you change the C<on_read> callback or push/unshift a read callback, and it
		1268	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1269	there are any read requests in the queue.
		1270
		1271	These methods will have no effect when in TLS mode (as TLS doesn't support
		1272	half-duplex connections).
569		1273
570	=cut	1274	=cut
571		1275
572	sub stop_read {	1276	sub stop_read {
573	my ($self) = @_;	1277	my ($self) = @_;
574		1278
575	delete $self->{rw};	1279	delete $self->{_rw} unless $self->{tls};
576	}	1280	}
577		1281
578	sub start_read {	1282	sub start_read {
579	my ($self) = @_;	1283	my ($self) = @_;
580		1284
581	unless ($self->{rw} || $self->{eof}) {	1285	unless ($self->{_rw} || $self->{_eof}) {
582	Scalar::Util::weaken $self;	1286	Scalar::Util::weaken $self;
583		1287
584	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1288	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1289	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
585	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1290	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
586		1291
587	if ($len > 0) {	1292	if ($len > 0) {
588	if (defined $self->{rbuf_max}) {	1293	$self->{_activity} = AnyEvent->now;
589	if ($self->{rbuf_max} < length $self->{rbuf}) {	1294
590	$! = &Errno::ENOSPC; return $self->error;	1295	if ($self->{tls}) {
591	}	1296	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1297
		1298	&_dotls ($self);
		1299	} else {
		1300	$self->_drain_rbuf unless $self->{_in_drain};
592	}	1301	}
593		1302
594	} elsif (defined $len) {	1303	} elsif (defined $len) {
595	$self->{eof} = 1;
596	delete $self->{rw};	1304	delete $self->{_rw};
		1305	$self->{_eof} = 1;
		1306	$self->_drain_rbuf unless $self->{_in_drain};
597		1307
598	} elsif ($! != EAGAIN && $! != EINTR) {	1308	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
599	return $self->error;	1309	return $self->_error ($!, 1);
600	}	1310	}
601
602	$self->_drain_rbuf;
603	});	1311	});
604	}	1312	}
605	}	1313	}
606		1314
		1315	# poll the write BIO and send the data if applicable
		1316	sub _dotls {
		1317	my ($self) = @_;
		1318
		1319	my $tmp;
		1320
		1321	if (length $self->{_tls_wbuf}) {
		1322	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1323	substr $self->{_tls_wbuf}, 0, $tmp, "";
		1324	}
		1325	}
		1326
		1327	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1328	unless (length $tmp) {
		1329	# let's treat SSL-eof as we treat normal EOF
		1330	delete $self->{_rw};
		1331	$self->{_eof} = 1;
		1332	&_freetls;
		1333	}
		1334
		1335	$self->{rbuf} .= $tmp;
		1336	$self->_drain_rbuf unless $self->{_in_drain};
		1337	$self->{tls} or return; # tls session might have gone away in callback
		1338	}
		1339
		1340	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1341
		1342	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
		1343	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
		1344	return $self->_error ($!, 1);
		1345	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
		1346	return $self->_error (&Errno::EIO, 1);
		1347	}
		1348
		1349	# all other errors are fine for our purposes
		1350	}
		1351
		1352	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1353	$self->{wbuf} .= $tmp;
		1354	$self->_drain_wbuf;
		1355	}
		1356	}
		1357
		1358	=item $handle->starttls ($tls[, $tls_ctx])
		1359
		1360	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1361	object is created, you can also do that at a later time by calling
		1362	C<starttls>.
		1363
		1364	The first argument is the same as the C<tls> constructor argument (either
		1365	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1366
		1367	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1368	used when AnyEvent::Handle has to create its own TLS connection object.
		1369
		1370	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1371	call and can be used or changed to your liking. Note that the handshake
		1372	might have already started when this function returns.
		1373
		1374	If it an error to start a TLS handshake more than once per
		1375	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1376
		1377	=cut
		1378
		1379	sub starttls {
		1380	my ($self, $ssl, $ctx) = @_;
		1381
		1382	require Net::SSLeay;
		1383
		1384	Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"
		1385	if $self->{tls};
		1386
		1387	if ($ssl eq "accept") {
		1388	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1389	Net::SSLeay::set_accept_state ($ssl);
		1390	} elsif ($ssl eq "connect") {
		1391	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1392	Net::SSLeay::set_connect_state ($ssl);
		1393	}
		1394
		1395	$self->{tls} = $ssl;
		1396
		1397	# basically, this is deep magic (because SSL_read should have the same issues)
		1398	# but the openssl maintainers basically said: "trust us, it just works".
		1399	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1400	# and mismaintained ssleay-module doesn't even offer them).
		1401	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1402	#
		1403	# in short: this is a mess.
		1404	#
		1405	# note that we do not try to keep the length constant between writes as we are required to do.
		1406	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1407	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1408	# have identity issues in that area.
		1409	Net::SSLeay::CTX_set_mode ($self->{tls},
		1410	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1411	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1412
		1413	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1414	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1415
		1416	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1417
		1418	&_dotls; # need to trigger the initial handshake
		1419	$self->start_read; # make sure we actually do read
		1420	}
		1421
		1422	=item $handle->stoptls
		1423
		1424	Shuts down the SSL connection - this makes a proper EOF handshake by
		1425	sending a close notify to the other side, but since OpenSSL doesn't
		1426	support non-blocking shut downs, it is not possible to re-use the stream
		1427	afterwards.
		1428
		1429	=cut
		1430
		1431	sub stoptls {
		1432	my ($self) = @_;
		1433
		1434	if ($self->{tls}) {
		1435	Net::SSLeay::shutdown ($self->{tls});
		1436
		1437	&_dotls;
		1438
		1439	# we don't give a shit. no, we do, but we can't. no...
		1440	# we, we... have to use openssl :/
		1441	&_freetls;
		1442	}
		1443	}
		1444
		1445	sub _freetls {
		1446	my ($self) = @_;
		1447
		1448	return unless $self->{tls};
		1449
		1450	Net::SSLeay::free (delete $self->{tls});
		1451
		1452	delete @$self{qw(_rbio _wbio _tls_wbuf)};
		1453	}
		1454
		1455	sub DESTROY {
		1456	my $self = shift;
		1457
		1458	&_freetls;
		1459
		1460	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1461
		1462	if ($linger && length $self->{wbuf}) {
		1463	my $fh = delete $self->{fh};
		1464	my $wbuf = delete $self->{wbuf};
		1465
		1466	my @linger;
		1467
		1468	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1469	my $len = syswrite $fh, $wbuf, length $wbuf;
		1470
		1471	if ($len > 0) {
		1472	substr $wbuf, 0, $len, "";
		1473	} else {
		1474	@linger = (); # end
		1475	}
		1476	});
		1477	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1478	@linger = ();
		1479	});
		1480	}
		1481	}
		1482
		1483	=item AnyEvent::Handle::TLS_CTX
		1484
		1485	This function creates and returns the Net::SSLeay::CTX object used by
		1486	default for TLS mode.
		1487
		1488	The context is created like this:
		1489
		1490	Net::SSLeay::load_error_strings;
		1491	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1492	Net::SSLeay::randomize;
		1493
		1494	my $CTX = Net::SSLeay::CTX_new;
		1495
		1496	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1497
		1498	=cut
		1499
		1500	our $TLS_CTX;
		1501
		1502	sub TLS_CTX() {
		1503	$TLS_CTX || do {
		1504	require Net::SSLeay;
		1505
		1506	Net::SSLeay::load_error_strings ();
		1507	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1508	Net::SSLeay::randomize ();
		1509
		1510	$TLS_CTX = Net::SSLeay::CTX_new ();
		1511
		1512	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1513
		1514	$TLS_CTX
		1515	}
		1516	}
		1517
607	=back	1518	=back
608		1519
		1520
		1521	=head1 NONFREQUENTLY ASKED QUESTIONS
		1522
		1523	=over 4
		1524
		1525	=item How do I read data until the other side closes the connection?
		1526
		1527	If you just want to read your data into a perl scalar, the easiest way
		1528	to achieve this is by setting an C<on_read> callback that does nothing,
		1529	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1530	will be in C<$_[0]{rbuf}>:
		1531
		1532	$handle->on_read (sub { });
		1533	$handle->on_eof (undef);
		1534	$handle->on_error (sub {
		1535	my $data = delete $_[0]{rbuf};
		1536	undef $handle;
		1537	});
		1538
		1539	The reason to use C<on_error> is that TCP connections, due to latencies
		1540	and packets loss, might get closed quite violently with an error, when in
		1541	fact, all data has been received.
		1542
		1543	It is usually better to use acknowledgements when transfering data,
		1544	to make sure the other side hasn't just died and you got the data
		1545	intact. This is also one reason why so many internet protocols have an
		1546	explicit QUIT command.
		1547
		1548
		1549	=item I don't want to destroy the handle too early - how do I wait until
		1550	all data has been written?
		1551
		1552	After writing your last bits of data, set the C<on_drain> callback
		1553	and destroy the handle in there - with the default setting of
		1554	C<low_water_mark> this will be called precisely when all data has been
		1555	written to the socket:
		1556
		1557	$handle->push_write (...);
		1558	$handle->on_drain (sub {
		1559	warn "all data submitted to the kernel\n";
		1560	undef $handle;
		1561	});
		1562
		1563	=back
		1564
		1565
		1566	=head1 SUBCLASSING AnyEvent::Handle
		1567
		1568	In many cases, you might want to subclass AnyEvent::Handle.
		1569
		1570	To make this easier, a given version of AnyEvent::Handle uses these
		1571	conventions:
		1572
		1573	=over 4
		1574
		1575	=item * all constructor arguments become object members.
		1576
		1577	At least initially, when you pass a C<tls>-argument to the constructor it
		1578	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1579	mutated later on (for example C<tls> will hold the TLS connection object).
		1580
		1581	=item * other object member names are prefixed with an C<_>.
		1582
		1583	All object members not explicitly documented (internal use) are prefixed
		1584	with an underscore character, so the remaining non-C<_>-namespace is free
		1585	for use for subclasses.
		1586
		1587	=item * all members not documented here and not prefixed with an underscore
		1588	are free to use in subclasses.
		1589
		1590	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1591	member variables, but thats just life, at least it is documented.
		1592
		1593	=back
		1594
609	=head1 AUTHOR	1595	=head1 AUTHOR
610		1596
611	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1597	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
612		1598
613	=cut	1599	=cut

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