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Revision 1.95 by root, Thu Oct 2 06:42:39 2008 UTC

1	package AnyEvent::Handle;	1	package AnyEvent::Handle;
2		2
3	no warnings;	3	no warnings;
4	use strict;	4	use strict qw(subs vars);
5		5
6	use AnyEvent ();	6	use AnyEvent ();
7	use AnyEvent::Util ();	7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
8	use Scalar::Util ();	8	use Scalar::Util ();
9	use Carp ();	9	use Carp ();
10	use Fcntl ();	10	use Fcntl ();
11	use Errno qw/EAGAIN EINTR/;	11	use Errno qw(EAGAIN EINTR);
12		12
13	=head1 NAME	13	=head1 NAME
14		14
15	AnyEvent::Handle - non-blocking I/O on filehandles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	This module is experimental.
18
19	=cut	17	=cut
20		18
21	our $VERSION = '0.04';	19	our $VERSION = 4.3;
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	&_dotls ($self);
		556	} else {
		557	$self->{wbuf} .= $_[0];
		558	$self->_drain_wbuf;
		559	}
		560	}
		561
		562	=item $handle->push_write (type => @args)
		563
		564	Instead of formatting your data yourself, you can also let this module do
		565	the job by specifying a type and type-specific arguments.
		566
		567	Predefined types are (if you have ideas for additional types, feel free to
		568	drop by and tell us):
		569
		570	=over 4
		571
		572	=item netstring => $string
		573
		574	Formats the given value as netstring
		575	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		576
		577	=cut
		578
		579	register_write_type netstring => sub {
		580	my ($self, $string) = @_;
		581
		582	sprintf "%d:%s,", (length $string), $string
		583	};
		584
		585	=item packstring => $format, $data
		586
		587	An octet string prefixed with an encoded length. The encoding C<$format>
		588	uses the same format as a Perl C<pack> format, but must specify a single
		589	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		590	optional C<!>, C<< < >> or C<< > >> modifier).
		591
		592	=cut
		593
		594	register_write_type packstring => sub {
		595	my ($self, $format, $string) = @_;
		596
		597	pack "$format/a*", $string
		598	};
		599
		600	=item json => $array_or_hashref
		601
		602	Encodes the given hash or array reference into a JSON object. Unless you
		603	provide your own JSON object, this means it will be encoded to JSON text
		604	in UTF-8.
		605
		606	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		607	one end of a handle and read them at the other end without using any
		608	additional framing.
		609
		610	The generated JSON text is guaranteed not to contain any newlines: While
		611	this module doesn't need delimiters after or between JSON texts to be
		612	able to read them, many other languages depend on that.
		613
		614	A simple RPC protocol that interoperates easily with others is to send
		615	JSON arrays (or objects, although arrays are usually the better choice as
		616	they mimic how function argument passing works) and a newline after each
		617	JSON text:
		618
		619	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		620	$handle->push_write ("\012");
		621
		622	An AnyEvent::Handle receiver would simply use the C<json> read type and
		623	rely on the fact that the newline will be skipped as leading whitespace:
		624
		625	$handle->push_read (json => sub { my $array = $_[1]; ... });
		626
		627	Other languages could read single lines terminated by a newline and pass
		628	this line into their JSON decoder of choice.
		629
		630	=cut
		631
		632	register_write_type json => sub {
		633	my ($self, $ref) = @_;
		634
		635	require JSON;
		636
		637	$self->{json} ? $self->{json}->encode ($ref)
		638	: JSON::encode_json ($ref)
		639	};
		640
		641	=item storable => $reference
		642
		643	Freezes the given reference using L<Storable> and writes it to the
		644	handle. Uses the C<nfreeze> format.
		645
		646	=cut
		647
		648	register_write_type storable => sub {
		649	my ($self, $ref) = @_;
		650
		651	require Storable;
		652
		653	pack "w/a*", Storable::nfreeze ($ref)
		654	};
		655
		656	=back
		657
		658	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		659
		660	This function (not method) lets you add your own types to C<push_write>.
		661	Whenever the given C<type> is used, C<push_write> will invoke the code
		662	reference with the handle object and the remaining arguments.
		663
		664	The code reference is supposed to return a single octet string that will
		665	be appended to the write buffer.
		666
		667	Note that this is a function, and all types registered this way will be
		668	global, so try to use unique names.
		669
		670	=cut
288		671
289	#############################################################################	672	#############################################################################
290		673
291	=back	674	=back
292		675
…		…
299	ways, the "simple" way, using only C<on_read> and the "complex" way, using	682	ways, the "simple" way, using only C<on_read> and the "complex" way, using
300	a queue.	683	a queue.
301		684
302	In the simple case, you just install an C<on_read> callback and whenever	685	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	686	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	687	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
305	or not.	688	leave the data there if you want to accumulate more (e.g. when only a
		689	partial message has been received so far).
306		690
307	In the more complex case, you want to queue multiple callbacks. In this	691	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	692	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>,	693	data arrives (also the first time it is queued) and removes it when it has
310	below).	694	done its job (see C<push_read>, below).
311		695
312	This way you can, for example, push three line-reads, followed by reading	696	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.	697	a chunk of data, and AnyEvent::Handle will execute them in order.
314		698
315	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	699	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
316	the specified number of bytes which give an XML datagram.	700	the specified number of bytes which give an XML datagram.
317		701
318	# in the default state, expect some header bytes	702	# in the default state, expect some header bytes
319	$handle->on_read (sub {	703	$handle->on_read (sub {
320	# some data is here, now queue the length-header-read (4 octets)	704	# some data is here, now queue the length-header-read (4 octets)
321	shift->unshift_read_chunk (4, sub {	705	shift->unshift_read (chunk => 4, sub {
322	# header arrived, decode	706	# header arrived, decode
323	my $len = unpack "N", $_[1];	707	my $len = unpack "N", $_[1];
324		708
325	# now read the payload	709	# now read the payload
326	shift->unshift_read_chunk ($len, sub {	710	shift->unshift_read (chunk => $len, sub {
327	my $xml = $_[1];	711	my $xml = $_[1];
328	# handle xml	712	# handle xml
329	});	713	});
330	});	714	});
331	});	715	});
332		716
333	Example 2: Implement a client for a protocol that replies either with	717	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	718	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	719	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	720	just pipeline sending both requests and manipulate the queue as necessary
337	the callbacks:	721	in the callbacks.
338		722
339	# request one	723	When the first callback is called and sees an "OK" response, it will
		724	C<unshift> another line-read. This line-read will be queued I<before> the
		725	64-byte chunk callback.
		726
		727	# request one, returns either "OK + extra line" or "ERROR"
340	$handle->push_write ("request 1\015\012");	728	$handle->push_write ("request 1\015\012");
341		729
342	# we expect "ERROR" or "OK" as response, so push a line read	730	# we expect "ERROR" or "OK" as response, so push a line read
343	$handle->push_read_line (sub {	731	$handle->push_read (line => sub {
344	# if we got an "OK", we have to _prepend_ another line,	732	# 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	733	# 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	734	# which are already in the queue when this callback is called
347	# we don't do this in case we got an error	735	# we don't do this in case we got an error
348	if ($_[1] eq "OK") {	736	if ($_[1] eq "OK") {
349	$_[0]->unshift_read_line (sub {	737	$_[0]->unshift_read (line => sub {
350	my $response = $_[1];	738	my $response = $_[1];
351	...	739	...
352	});	740	});
353	}	741	}
354	});	742	});
355		743
356	# request two	744	# request two, simply returns 64 octets
357	$handle->push_write ("request 2\015\012");	745	$handle->push_write ("request 2\015\012");
358		746
359	# simply read 64 bytes, always	747	# simply read 64 bytes, always
360	$handle->push_read_chunk (64, sub {	748	$handle->push_read (chunk => 64, sub {
361	my $response = $_[1];	749	my $response = $_[1];
362	...	750	...
363	});	751	});
364		752
365	=over 4	753	=over 4
…		…
367	=cut	755	=cut
368		756
369	sub _drain_rbuf {	757	sub _drain_rbuf {
370	my ($self) = @_;	758	my ($self) = @_;
371		759
372	return if $self->{in_drain};
373	local $self->{in_drain} = 1;	760	local $self->{_in_drain} = 1;
374		761
		762	if (
		763	defined $self->{rbuf_max}
		764	&& $self->{rbuf_max} < length $self->{rbuf}
		765	) {
		766	$self->_error (&Errno::ENOSPC, 1), return;
		767	}
		768
		769	while () {
375	while (my $len = length $self->{rbuf}) {	770	my $len = length $self->{rbuf};
376	no strict 'refs';	771
377	if (my $cb = shift @{ $self->{queue} }) {	772	if (my $cb = shift @{ $self->{_queue} }) {
378	if (!$cb->($self)) {	773	unless ($cb->($self)) {
379	if ($self->{eof}) {	774	if ($self->{_eof}) {
380	# no progress can be made (not enough data and no data forthcoming)	775	# no progress can be made (not enough data and no data forthcoming)
381	$! = &Errno::EPIPE; return $self->error;	776	$self->_error (&Errno::EPIPE, 1), return;
382	}	777	}
383		778
384	unshift @{ $self->{queue} }, $cb;	779	unshift @{ $self->{_queue} }, $cb;
385	return;	780	last;
386	}	781	}
387	} elsif ($self->{on_read}) {	782	} elsif ($self->{on_read}) {
		783	last unless $len;
		784
388	$self->{on_read}($self);	785	$self->{on_read}($self);
389		786
390	if (	787	if (
391	$self->{eof} # if no further data will arrive
392	&& $len == length $self->{rbuf} # and no data has been consumed	788	$len == length $self->{rbuf} # if no data has been consumed
393	&& !@{ $self->{queue} } # and the queue is still empty	789	&& !@{ $self->{_queue} } # and the queue is still empty
394	&& $self->{on_read} # and we still want to read data	790	&& $self->{on_read} # but we still have on_read
395	) {	791	) {
		792	# no further data will arrive
396	# then no progress can be made	793	# so no progress can be made
397	$! = &Errno::EPIPE; return $self->error;	794	$self->_error (&Errno::EPIPE, 1), return
		795	if $self->{_eof};
		796
		797	last; # more data might arrive
398	}	798	}
399	} else {	799	} else {
400	# read side becomes idle	800	# read side becomes idle
401	delete $self->{rw};	801	delete $self->{_rw} unless $self->{tls};
402	return;	802	last;
403	}	803	}
404	}	804	}
405		805
406	if ($self->{eof}) {	806	if ($self->{_eof}) {
407	$self->_shutdown;	807	if ($self->{on_eof}) {
408	$self->{on_eof}($self)	808	$self->{on_eof}($self)
409	if $self->{on_eof};	809	} else {
		810	$self->_error (0, 1);
		811	}
		812	}
		813
		814	# may need to restart read watcher
		815	unless ($self->{_rw}) {
		816	$self->start_read
		817	if $self->{on_read} || @{ $self->{_queue} };
410	}	818	}
411	}	819	}
412		820
413	=item $handle->on_read ($cb)	821	=item $handle->on_read ($cb)
414		822
…		…
420		828
421	sub on_read {	829	sub on_read {
422	my ($self, $cb) = @_;	830	my ($self, $cb) = @_;
423		831
424	$self->{on_read} = $cb;	832	$self->{on_read} = $cb;
		833	$self->_drain_rbuf if $cb && !$self->{_in_drain};
425	}	834	}
426		835
427	=item $handle->rbuf	836	=item $handle->rbuf
428		837
429	Returns the read buffer (as a modifiable lvalue).	838	Returns the read buffer (as a modifiable lvalue).
…		…
448	Append the given callback to the end of the queue (C<push_read>) or	857	Append the given callback to the end of the queue (C<push_read>) or
449	prepend it (C<unshift_read>).	858	prepend it (C<unshift_read>).
450		859
451	The callback is called each time some additional read data arrives.	860	The callback is called each time some additional read data arrives.
452		861
453	It must check wether enough data is in the read buffer already.	862	It must check whether enough data is in the read buffer already.
454		863
455	If not enough data is available, it must return the empty list or a false	864	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	865	value, in which case it will be called repeatedly until enough data is
457	available (or an error condition is detected).	866	available (or an error condition is detected).
458		867
…		…
460	interested in (which can be none at all) and return a true value. After returning	869	interested in (which can be none at all) and return a true value. After returning
461	true, it will be removed from the queue.	870	true, it will be removed from the queue.
462		871
463	=cut	872	=cut
464		873
		874	our %RH;
		875
		876	sub register_read_type($$) {
		877	$RH{$_[0]} = $_[1];
		878	}
		879
465	sub push_read {	880	sub push_read {
466	my ($self, $cb) = @_;	881	my $self = shift;
		882	my $cb = pop;
467		883
		884	if (@_) {
		885	my $type = shift;
		886
		887	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		888	->($self, $cb, @_);
		889	}
		890
468	push @{ $self->{queue} }, $cb;	891	push @{ $self->{_queue} }, $cb;
469	$self->_drain_rbuf;	892	$self->_drain_rbuf unless $self->{_in_drain};
470	}	893	}
471		894
472	sub unshift_read {	895	sub unshift_read {
473	my ($self, $cb) = @_;	896	my $self = shift;
		897	my $cb = pop;
474		898
		899	if (@_) {
		900	my $type = shift;
		901
		902	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		903	->($self, $cb, @_);
		904	}
		905
		906
475	push @{ $self->{queue} }, $cb;	907	unshift @{ $self->{_queue} }, $cb;
476	$self->_drain_rbuf;	908	$self->_drain_rbuf unless $self->{_in_drain};
477	}	909	}
478		910
479	=item $handle->push_read_chunk ($len, $cb->($self, $data))	911	=item $handle->push_read (type => @args, $cb)
480		912
481	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	913	=item $handle->unshift_read (type => @args, $cb)
482		914
483	Append the given callback to the end of the queue (C<push_read_chunk>) or	915	Instead of providing a callback that parses the data itself you can chose
484	prepend it (C<unshift_read_chunk>).	916	between a number of predefined parsing formats, for chunks of data, lines
		917	etc.
485		918
486	The callback will be called only once C<$len> bytes have been read, and	919	Predefined types are (if you have ideas for additional types, feel free to
487	these C<$len> bytes will be passed to the callback.	920	drop by and tell us):
488		921
489	=cut	922	=over 4
490		923
491	sub _read_chunk($$) {	924	=item chunk => $octets, $cb->($handle, $data)
		925
		926	Invoke the callback only once C<$octets> bytes have been read. Pass the
		927	data read to the callback. The callback will never be called with less
		928	data.
		929
		930	Example: read 2 bytes.
		931
		932	$handle->push_read (chunk => 2, sub {
		933	warn "yay ", unpack "H*", $_[1];
		934	});
		935
		936	=cut
		937
		938	register_read_type chunk => sub {
492	my ($self, $len, $cb) = @_;	939	my ($self, $cb, $len) = @_;
493		940
494	sub {	941	sub {
495	$len <= length $_[0]{rbuf} or return;	942	$len <= length $_[0]{rbuf} or return;
496	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	943	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
497	1	944	1
498	}	945	}
499	}	946	};
500		947
501	sub push_read_chunk {	948	=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		949
517	The callback will be called only once a full line (including the end of	950	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	951	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	952	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>).	953	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	964	Partial lines at the end of the stream will never be returned, as they are
532	not marked by the end of line marker.	965	not marked by the end of line marker.
533		966
534	=cut	967	=cut
535		968
536	sub _read_line($$) {	969	register_read_type line => sub {
537	my $self = shift;	970	my ($self, $cb, $eol) = @_;
538	my $cb = pop;
539	my $eol = @_ ? shift : qr|(\015?\012)|;
540	my $pos;
541		971
		972	if (@_ < 3) {
		973	# this is more than twice as fast as the generic code below
		974	sub {
		975	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		976
		977	$cb->($_[0], $1, $2);
		978	1
		979	}
		980	} else {
542	$eol = quotemeta $eol unless ref $eol;	981	$eol = quotemeta $eol unless ref $eol;
543	$eol = qr|^(.*?)($eol)|s;	982	$eol = qr|^(.*?)($eol)|s;
		983
		984	sub {
		985	$_[0]{rbuf} =~ s/$eol// or return;
		986
		987	$cb->($_[0], $1, $2);
		988	1
		989	}
		990	}
		991	};
		992
		993	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		994
		995	Makes a regex match against the regex object C<$accept> and returns
		996	everything up to and including the match.
		997
		998	Example: read a single line terminated by '\n'.
		999
		1000	$handle->push_read (regex => qr<\n>, sub { ... });
		1001
		1002	If C<$reject> is given and not undef, then it determines when the data is
		1003	to be rejected: it is matched against the data when the C<$accept> regex
		1004	does not match and generates an C<EBADMSG> error when it matches. This is
		1005	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		1006	receive buffer overflow).
		1007
		1008	Example: expect a single decimal number followed by whitespace, reject
		1009	anything else (not the use of an anchor).
		1010
		1011	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1012
		1013	If C<$skip> is given and not C<undef>, then it will be matched against
		1014	the receive buffer when neither C<$accept> nor C<$reject> match,
		1015	and everything preceding and including the match will be accepted
		1016	unconditionally. This is useful to skip large amounts of data that you
		1017	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1018	have to start matching from the beginning. This is purely an optimisation
		1019	and is usually worth only when you expect more than a few kilobytes.
		1020
		1021	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1022	expect the header to be very large (it isn't in practise, but...), we use
		1023	a skip regex to skip initial portions. The skip regex is tricky in that
		1024	it only accepts something not ending in either \015 or \012, as these are
		1025	required for the accept regex.
		1026
		1027	$handle->push_read (regex =>
		1028	qr<\015\012\015\012>,
		1029	undef, # no reject
		1030	qr<^.*[^\015\012]>,
		1031	sub { ... });
		1032
		1033	=cut
		1034
		1035	register_read_type regex => sub {
		1036	my ($self, $cb, $accept, $reject, $skip) = @_;
		1037
		1038	my $data;
		1039	my $rbuf = \$self->{rbuf};
544		1040
545	sub {	1041	sub {
546	$_[0]{rbuf} =~ s/$eol// or return;	1042	# accept
		1043	if ($$rbuf =~ $accept) {
		1044	$data .= substr $$rbuf, 0, $+[0], "";
		1045	$cb->($self, $data);
		1046	return 1;
		1047	}
		1048
		1049	# reject
		1050	if ($reject && $$rbuf =~ $reject) {
		1051	$self->_error (&Errno::EBADMSG);
		1052	}
547		1053
548	$cb->($_[0], $1, $2);	1054	# skip
		1055	if ($skip && $$rbuf =~ $skip) {
		1056	$data .= substr $$rbuf, 0, $+[0], "";
		1057	}
		1058
		1059	()
		1060	}
		1061	};
		1062
		1063	=item netstring => $cb->($handle, $string)
		1064
		1065	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1066
		1067	Throws an error with C<$!> set to EBADMSG on format violations.
		1068
		1069	=cut
		1070
		1071	register_read_type netstring => sub {
		1072	my ($self, $cb) = @_;
		1073
		1074	sub {
		1075	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1076	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1077	$self->_error (&Errno::EBADMSG);
		1078	}
		1079	return;
		1080	}
		1081
		1082	my $len = $1;
		1083
		1084	$self->unshift_read (chunk => $len, sub {
		1085	my $string = $_[1];
		1086	$_[0]->unshift_read (chunk => 1, sub {
		1087	if ($_[1] eq ",") {
		1088	$cb->($_[0], $string);
		1089	} else {
		1090	$self->_error (&Errno::EBADMSG);
		1091	}
		1092	});
		1093	});
		1094
549	1	1095	1
550	}	1096	}
551	}	1097	};
552		1098
553	sub push_read_line {	1099	=item packstring => $format, $cb->($handle, $string)
554	$_[0]->push_read (&_read_line);
555	}
556		1100
557	sub unshift_read_line {	1101	An octet string prefixed with an encoded length. The encoding C<$format>
558	$_[0]->unshift_read (&_read_line);	1102	uses the same format as a Perl C<pack> format, but must specify a single
559	}	1103	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1104	optional C<!>, C<< < >> or C<< > >> modifier).
		1105
		1106	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1107
		1108	Example: read a block of data prefixed by its length in BER-encoded
		1109	format (very efficient).
		1110
		1111	$handle->push_read (packstring => "w", sub {
		1112	my ($handle, $data) = @_;
		1113	});
		1114
		1115	=cut
		1116
		1117	register_read_type packstring => sub {
		1118	my ($self, $cb, $format) = @_;
		1119
		1120	sub {
		1121	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1122	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1123	or return;
		1124
		1125	$format = length pack $format, $len;
		1126
		1127	# bypass unshift if we already have the remaining chunk
		1128	if ($format + $len <= length $_[0]{rbuf}) {
		1129	my $data = substr $_[0]{rbuf}, $format, $len;
		1130	substr $_[0]{rbuf}, 0, $format + $len, "";
		1131	$cb->($_[0], $data);
		1132	} else {
		1133	# remove prefix
		1134	substr $_[0]{rbuf}, 0, $format, "";
		1135
		1136	# read remaining chunk
		1137	$_[0]->unshift_read (chunk => $len, $cb);
		1138	}
		1139
		1140	1
		1141	}
		1142	};
		1143
		1144	=item json => $cb->($handle, $hash_or_arrayref)
		1145
		1146	Reads a JSON object or array, decodes it and passes it to the callback.
		1147
		1148	If a C<json> object was passed to the constructor, then that will be used
		1149	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1150
		1151	This read type uses the incremental parser available with JSON version
		1152	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1153	dependency on your own: this module will load the JSON module, but
		1154	AnyEvent does not depend on it itself.
		1155
		1156	Since JSON texts are fully self-delimiting, the C<json> read and write
		1157	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1158	the C<json> write type description, above, for an actual example.
		1159
		1160	=cut
		1161
		1162	register_read_type json => sub {
		1163	my ($self, $cb) = @_;
		1164
		1165	require JSON;
		1166
		1167	my $data;
		1168	my $rbuf = \$self->{rbuf};
		1169
		1170	my $json = $self->{json} ||= JSON->new->utf8;
		1171
		1172	sub {
		1173	my $ref = $json->incr_parse ($self->{rbuf});
		1174
		1175	if ($ref) {
		1176	$self->{rbuf} = $json->incr_text;
		1177	$json->incr_text = "";
		1178	$cb->($self, $ref);
		1179
		1180	1
		1181	} else {
		1182	$self->{rbuf} = "";
		1183	()
		1184	}
		1185	}
		1186	};
		1187
		1188	=item storable => $cb->($handle, $ref)
		1189
		1190	Deserialises a L<Storable> frozen representation as written by the
		1191	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1192	data).
		1193
		1194	Raises C<EBADMSG> error if the data could not be decoded.
		1195
		1196	=cut
		1197
		1198	register_read_type storable => sub {
		1199	my ($self, $cb) = @_;
		1200
		1201	require Storable;
		1202
		1203	sub {
		1204	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1205	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1206	or return;
		1207
		1208	my $format = length pack "w", $len;
		1209
		1210	# bypass unshift if we already have the remaining chunk
		1211	if ($format + $len <= length $_[0]{rbuf}) {
		1212	my $data = substr $_[0]{rbuf}, $format, $len;
		1213	substr $_[0]{rbuf}, 0, $format + $len, "";
		1214	$cb->($_[0], Storable::thaw ($data));
		1215	} else {
		1216	# remove prefix
		1217	substr $_[0]{rbuf}, 0, $format, "";
		1218
		1219	# read remaining chunk
		1220	$_[0]->unshift_read (chunk => $len, sub {
		1221	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1222	$cb->($_[0], $ref);
		1223	} else {
		1224	$self->_error (&Errno::EBADMSG);
		1225	}
		1226	});
		1227	}
		1228
		1229	1
		1230	}
		1231	};
		1232
		1233	=back
		1234
		1235	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1236
		1237	This function (not method) lets you add your own types to C<push_read>.
		1238
		1239	Whenever the given C<type> is used, C<push_read> will invoke the code
		1240	reference with the handle object, the callback and the remaining
		1241	arguments.
		1242
		1243	The code reference is supposed to return a callback (usually a closure)
		1244	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1245
		1246	It should invoke the passed callback when it is done reading (remember to
		1247	pass C<$handle> as first argument as all other callbacks do that).
		1248
		1249	Note that this is a function, and all types registered this way will be
		1250	global, so try to use unique names.
		1251
		1252	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1253	search for C<register_read_type>)).
560		1254
561	=item $handle->stop_read	1255	=item $handle->stop_read
562		1256
563	=item $handle->start_read	1257	=item $handle->start_read
564		1258
565	In rare cases you actually do not want to read anything form the	1259	In rare cases you actually do not want to read anything from the
566	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1260	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
567	any queued callbacks will be executed then. To start readign again, call	1261	any queued callbacks will be executed then. To start reading again, call
568	C<start_read>.	1262	C<start_read>.
		1263
		1264	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1265	you change the C<on_read> callback or push/unshift a read callback, and it
		1266	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1267	there are any read requests in the queue.
		1268
		1269	These methods will have no effect when in TLS mode (as TLS doesn't support
		1270	half-duplex connections).
569		1271
570	=cut	1272	=cut
571		1273
572	sub stop_read {	1274	sub stop_read {
573	my ($self) = @_;	1275	my ($self) = @_;
574		1276
575	delete $self->{rw};	1277	delete $self->{_rw} unless $self->{tls};
576	}	1278	}
577		1279
578	sub start_read {	1280	sub start_read {
579	my ($self) = @_;	1281	my ($self) = @_;
580		1282
581	unless ($self->{rw} || $self->{eof}) {	1283	unless ($self->{_rw} || $self->{_eof}) {
582	Scalar::Util::weaken $self;	1284	Scalar::Util::weaken $self;
583		1285
584	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1286	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1287	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
585	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1288	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
586		1289
587	if ($len > 0) {	1290	if ($len > 0) {
588	if (defined $self->{rbuf_max}) {	1291	$self->{_activity} = AnyEvent->now;
589	if ($self->{rbuf_max} < length $self->{rbuf}) {	1292
590	$! = &Errno::ENOSPC; return $self->error;	1293	if ($self->{tls}) {
591	}	1294	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1295	&_dotls ($self);
		1296	} else {
		1297	$self->_drain_rbuf unless $self->{_in_drain};
592	}	1298	}
593		1299
594	} elsif (defined $len) {	1300	} elsif (defined $len) {
595	$self->{eof} = 1;
596	delete $self->{rw};	1301	delete $self->{_rw};
		1302	$self->{_eof} = 1;
		1303	$self->_drain_rbuf unless $self->{_in_drain};
597		1304
598	} elsif ($! != EAGAIN && $! != EINTR) {	1305	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
599	return $self->error;	1306	return $self->_error ($!, 1);
600	}	1307	}
601
602	$self->_drain_rbuf;
603	});	1308	});
604	}	1309	}
605	}	1310	}
606		1311
		1312	sub _dotls {
		1313	my ($self) = @_;
		1314
		1315	my $buf;
		1316
		1317	if (length $self->{_tls_wbuf}) {
		1318	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1319	substr $self->{_tls_wbuf}, 0, $len, "";
		1320	}
		1321	}
		1322
		1323	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1324	unless (length $buf) {
		1325	# let's treat SSL-eof as we treat normal EOF
		1326	delete $self->{_rw};
		1327	$self->{_eof} = 1;
		1328	&_freetls;
		1329	}
		1330
		1331	$self->{rbuf} .= $buf;
		1332	$self->_drain_rbuf unless $self->{_in_drain};
		1333	$self->{tls} or return; # tls session might have gone away in callback
		1334	}
		1335
		1336	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1337
		1338	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1339	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1340	return $self->_error ($!, 1);
		1341	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1342	return $self->_error (&Errno::EIO, 1);
		1343	}
		1344
		1345	# all others are fine for our purposes
		1346	}
		1347
		1348	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1349	$self->{wbuf} .= $buf;
		1350	$self->_drain_wbuf;
		1351	}
		1352	}
		1353
		1354	=item $handle->starttls ($tls[, $tls_ctx])
		1355
		1356	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1357	object is created, you can also do that at a later time by calling
		1358	C<starttls>.
		1359
		1360	The first argument is the same as the C<tls> constructor argument (either
		1361	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1362
		1363	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1364	used when AnyEvent::Handle has to create its own TLS connection object.
		1365
		1366	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1367	call and can be used or changed to your liking. Note that the handshake
		1368	might have already started when this function returns.
		1369
		1370	If it an error to start a TLS handshake more than once per
		1371	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1372
		1373	=cut
		1374
		1375	sub starttls {
		1376	my ($self, $ssl, $ctx) = @_;
		1377
		1378	require Net::SSLeay;
		1379
		1380	Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object"
		1381	if $self->{tls};
		1382
		1383	if ($ssl eq "accept") {
		1384	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1385	Net::SSLeay::set_accept_state ($ssl);
		1386	} elsif ($ssl eq "connect") {
		1387	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1388	Net::SSLeay::set_connect_state ($ssl);
		1389	}
		1390
		1391	$self->{tls} = $ssl;
		1392
		1393	# basically, this is deep magic (because SSL_read should have the same issues)
		1394	# but the openssl maintainers basically said: "trust us, it just works".
		1395	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1396	# and mismaintained ssleay-module doesn't even offer them).
		1397	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1398	#
		1399	# in short: this is a mess.
		1400	#
		1401	# note that we do not try to keep the length constant between writes as we are required to do.
		1402	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1403	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1404	# have identity issues in that area.
		1405	Net::SSLeay::CTX_set_mode ($self->{tls},
		1406	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1407	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1408
		1409	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1410	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1411
		1412	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1413
		1414	&_dotls; # need to trigger the initial handshake
		1415	$self->start_read; # make sure we actually do read
		1416	}
		1417
		1418	=item $handle->stoptls
		1419
		1420	Shuts down the SSL connection - this makes a proper EOF handshake by
		1421	sending a close notify to the other side, but since OpenSSL doesn't
		1422	support non-blocking shut downs, it is not possible to re-use the stream
		1423	afterwards.
		1424
		1425	=cut
		1426
		1427	sub stoptls {
		1428	my ($self) = @_;
		1429
		1430	if ($self->{tls}) {
		1431	Net::SSLeay::shutdown ($self->{tls});
		1432
		1433	&_dotls;
		1434
		1435	# we don't give a shit. no, we do, but we can't. no...
		1436	# we, we... have to use openssl :/
		1437	&_freetls;
		1438	}
		1439	}
		1440
		1441	sub _freetls {
		1442	my ($self) = @_;
		1443
		1444	return unless $self->{tls};
		1445
		1446	Net::SSLeay::free (delete $self->{tls});
		1447
		1448	delete @$self{qw(_rbio _wbio _tls_wbuf)};
		1449	}
		1450
		1451	sub DESTROY {
		1452	my $self = shift;
		1453
		1454	&_freetls;
		1455
		1456	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1457
		1458	if ($linger && length $self->{wbuf}) {
		1459	my $fh = delete $self->{fh};
		1460	my $wbuf = delete $self->{wbuf};
		1461
		1462	my @linger;
		1463
		1464	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1465	my $len = syswrite $fh, $wbuf, length $wbuf;
		1466
		1467	if ($len > 0) {
		1468	substr $wbuf, 0, $len, "";
		1469	} else {
		1470	@linger = (); # end
		1471	}
		1472	});
		1473	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1474	@linger = ();
		1475	});
		1476	}
		1477	}
		1478
		1479	=item AnyEvent::Handle::TLS_CTX
		1480
		1481	This function creates and returns the Net::SSLeay::CTX object used by
		1482	default for TLS mode.
		1483
		1484	The context is created like this:
		1485
		1486	Net::SSLeay::load_error_strings;
		1487	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1488	Net::SSLeay::randomize;
		1489
		1490	my $CTX = Net::SSLeay::CTX_new;
		1491
		1492	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1493
		1494	=cut
		1495
		1496	our $TLS_CTX;
		1497
		1498	sub TLS_CTX() {
		1499	$TLS_CTX || do {
		1500	require Net::SSLeay;
		1501
		1502	Net::SSLeay::load_error_strings ();
		1503	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1504	Net::SSLeay::randomize ();
		1505
		1506	$TLS_CTX = Net::SSLeay::CTX_new ();
		1507
		1508	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1509
		1510	$TLS_CTX
		1511	}
		1512	}
		1513
607	=back	1514	=back
608		1515
		1516
		1517	=head1 NONFREQUENTLY ASKED QUESTIONS
		1518
		1519	=over 4
		1520
		1521	=item How do I read data until the other side closes the connection?
		1522
		1523	If you just want to read your data into a perl scalar, the easiest way to achieve this is
		1524	by setting an C<on_read> callback that does nothing, clearing the C<on_eof> callback
		1525	and in the C<on_error> callback, the data will be in C<$_[0]{rbuf}>:
		1526
		1527	$handle->on_read (sub { });
		1528	$handle->on_eof (undef);
		1529	$handle->on_error (sub {
		1530	my $data = delete $_[0]{rbuf};
		1531	undef $handle;
		1532	});
		1533
		1534	The reason to use C<on_error> is that TCP connections, due to latencies
		1535	and packets loss, might get closed quite violently with an error, when in
		1536	fact, all data has been received.
		1537
		1538	It is usually better to use acknowledgements when transfering data,
		1539	to make sure the other side hasn't just died and you got the data
		1540	intact. This is also one reason why so many internet protocols have an
		1541	explicit QUIT command.
		1542
		1543
		1544	=item I don't want to destroy the handle too early - how do I wait until all data has been sent?
		1545
		1546	After writing your last bits of data, set the C<on_drain> callback
		1547	and destroy the handle in there - with the default setting of
		1548	C<low_water_mark> this will be called precisely when all data has been
		1549	written to the socket:
		1550
		1551	$handle->push_write (...);
		1552	$handle->on_drain (sub {
		1553	warn "all data submitted to the kernel\n";
		1554	undef $handle;
		1555	});
		1556
		1557	=back
		1558
		1559
		1560	=head1 SUBCLASSING AnyEvent::Handle
		1561
		1562	In many cases, you might want to subclass AnyEvent::Handle.
		1563
		1564	To make this easier, a given version of AnyEvent::Handle uses these
		1565	conventions:
		1566
		1567	=over 4
		1568
		1569	=item * all constructor arguments become object members.
		1570
		1571	At least initially, when you pass a C<tls>-argument to the constructor it
		1572	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1573	mutated later on (for example C<tls> will hold the TLS connection object).
		1574
		1575	=item * other object member names are prefixed with an C<_>.
		1576
		1577	All object members not explicitly documented (internal use) are prefixed
		1578	with an underscore character, so the remaining non-C<_>-namespace is free
		1579	for use for subclasses.
		1580
		1581	=item * all members not documented here and not prefixed with an underscore
		1582	are free to use in subclasses.
		1583
		1584	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1585	member variables, but thats just life, at least it is documented.
		1586
		1587	=back
		1588
609	=head1 AUTHOR	1589	=head1 AUTHOR
610		1590
611	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1591	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
612		1592
613	=cut	1593	=cut

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