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Revision 1.13 by elmex, Thu May 15 13:32:19 2008 UTC vs.
Revision 1.86 by root, Thu Aug 21 20:41:16 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	=cut	17	=cut
18		18
19	our $VERSION = '0.02';	19	our $VERSION = 4.232;
20		20
21	=head1 SYNOPSIS	21	=head1 SYNOPSIS
22		22
23	use AnyEvent;	23	use AnyEvent;
24	use AnyEvent::Handle;	24	use AnyEvent::Handle;
25		25
26	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
27		27
28	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
29
30	#TODO
31
32	# or use the constructor to pass the callback:
33
34	my $ae_fh2 =
35	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
36	fh => \*STDIN,	30	fh => \*STDIN,
37	on_eof => sub {	31	on_eof => sub {
38	$cv->broadcast;	32	$cv->broadcast;
39	},	33	},
40	#TODO
41	);	34	);
42		35
43	$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;
44		47
45	=head1 DESCRIPTION	48	=head1 DESCRIPTION
46		49
47	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
48	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
49	on sockets see L<AnyEvent::Util>.	52	on sockets see L<AnyEvent::Util>.
50		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
51	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
52	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
53	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
54		60
55	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
…		…
67		73
68	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
69		75
70	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
71		77
72	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
73	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
74		81
75	=item on_eof => $cb->($self) [MANDATORY]
76
77	Set the callback to be called on EOF.
78
79	=item on_error => $cb->($self)	82	=item on_eof => $cb->($handle)
80		83
		84	Set the callback to be called when an end-of-file condition is detected,
		85	i.e. in the case of a socket, when the other side has closed the
		86	connection cleanly.
		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the eof
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
		93	While not mandatory, it is I<highly> recommended to set an eof callback,
		94	otherwise you might end up with a closed socket while you are still
		95	waiting for data.
		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
		99
		100	=item on_error => $cb->($handle, $fatal)
		101
81	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
82	ocurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
83	or a read error.	104	connect or a read error.
84		105
85	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
86	called.	107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C< ->rbuf >). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
		111
		112	Non-fatal errors can be retried by simply returning, but it is recommended
		113	to simply ignore this parameter and instead abondon the handle object
		114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
87		116
88	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
89	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
90		119
91	While not mandatory, it is I<highly> recommended to set this callback, as	120	While not mandatory, it is I<highly> recommended to set this callback, as
92	you will not be notified of errors otherwise. The default simply calls	121	you will not be notified of errors otherwise. The default simply calls
93	die.	122	C<croak>.
94		123
95	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
96		125
97	This sets the default read callback, which is called when data arrives	126	This sets the default read callback, which is called when data arrives
98	and no read request is in the queue.	127	and no read request is in the queue (unlike read queue callbacks, this
		128	callback will only be called when at least one octet of data is in the
		129	read buffer).
99		130
100	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
101	method or acces sthe C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
102		133
103	When an EOF condition is detected then AnyEvent::Handle will first try to	134	When an EOF condition is detected then AnyEvent::Handle will first try to
104	feed all the remaining data to the queued callbacks and C<on_read> before	135	feed all the remaining data to the queued callbacks and C<on_read> before
105	calling the C<on_eof> callback. If no progress can be made, then a fatal	136	calling the C<on_eof> callback. If no progress can be made, then a fatal
106	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
107		138
108	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
109		140
110	This sets the callback that is called when the write buffer becomes empty	141	This sets the callback that is called when the write buffer becomes empty
111	(or when the callback is set and the buffer is empty already).	142	(or when the callback is set and the buffer is empty already).
112		143
113	To append to the write buffer, use the C<< ->push_write >> method.	144	To append to the write buffer, use the C<< ->push_write >> method.
		145
		146	This callback is useful when you don't want to put all of your write data
		147	into the queue at once, for example, when you want to write the contents
		148	of some file to the socket you might not want to read the whole file into
		149	memory and push it into the queue, but instead only read more data from
		150	the file when the write queue becomes empty.
		151
		152	=item timeout => $fractional_seconds
		153
		154	If non-zero, then this enables an "inactivity" timeout: whenever this many
		155	seconds pass without a successful read or write on the underlying file
		156	handle, the C<on_timeout> callback will be invoked (and if that one is
		157	missing, an C<ETIMEDOUT> error will be raised).
		158
		159	Note that timeout processing is also active when you currently do not have
		160	any outstanding read or write requests: If you plan to keep the connection
		161	idle then you should disable the timout temporarily or ignore the timeout
		162	in the C<on_timeout> callback.
		163
		164	Zero (the default) disables this timeout.
		165
		166	=item on_timeout => $cb->($handle)
		167
		168	Called whenever the inactivity timeout passes. If you return from this
		169	callback, then the timeout will be reset as if some activity had happened,
		170	so this condition is not fatal in any way.
114		171
115	=item rbuf_max => <bytes>	172	=item rbuf_max => <bytes>
116		173
117	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	174	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
118	when the read buffer ever (strictly) exceeds this size. This is useful to	175	when the read buffer ever (strictly) exceeds this size. This is useful to
…		…
122	be configured to accept only so-and-so much data that it cannot act on	179	be configured to accept only so-and-so much data that it cannot act on
123	(for example, when expecting a line, an attacker could send an unlimited	180	(for example, when expecting a line, an attacker could send an unlimited
124	amount of data without a callback ever being called as long as the line	181	amount of data without a callback ever being called as long as the line
125	isn't finished).	182	isn't finished).
126		183
		184	=item autocork => <boolean>
		185
		186	When disabled (the default), then C<push_write> will try to immediately
		187	write the data to the handle if possible. This avoids having to register
		188	a write watcher and wait for the next event loop iteration, but can be
		189	inefficient if you write multiple small chunks (this disadvantage is
		190	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		191
		192	When enabled, then writes will always be queued till the next event loop
		193	iteration. This is efficient when you do many small writes per iteration,
		194	but less efficient when you do a single write only.
		195
		196	=item no_delay => <boolean>
		197
		198	When doing small writes on sockets, your operating system kernel might
		199	wait a bit for more data before actually sending it out. This is called
		200	the Nagle algorithm, and usually it is beneficial.
		201
		202	In some situations you want as low a delay as possible, which cna be
		203	accomplishd by setting this option to true.
		204
		205	The default is your opertaing system's default behaviour, this option
		206	explicitly enables or disables it, if possible.
		207
127	=item read_size => <bytes>	208	=item read_size => <bytes>
128		209
129	The default read block size (the amount of bytes this module will try to read	210	The default read block size (the amount of bytes this module will try to read
130	on each [loop iteration). Default: C<4096>.	211	during each (loop iteration). Default: C<8192>.
131		212
132	=item low_water_mark => <bytes>	213	=item low_water_mark => <bytes>
133		214
134	Sets the amount of bytes (default: C<0>) that make up an "empty" write	215	Sets the amount of bytes (default: C<0>) that make up an "empty" write
135	buffer: If the write reaches this size or gets even samller it is	216	buffer: If the write reaches this size or gets even samller it is
136	considered empty.	217	considered empty.
137		218
		219	=item linger => <seconds>
		220
		221	If non-zero (default: C<3600>), then the destructor of the
		222	AnyEvent::Handle object will check wether there is still outstanding write
		223	data and will install a watcher that will write out this data. No errors
		224	will be reported (this mostly matches how the operating system treats
		225	outstanding data at socket close time).
		226
		227	This will not work for partial TLS data that could not yet been
		228	encoded. This data will be lost.
		229
		230	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		231
		232	When this parameter is given, it enables TLS (SSL) mode, that means
		233	AnyEvent will start a TLS handshake and will transparently encrypt/decrypt
		234	data.
		235
		236	TLS mode requires Net::SSLeay to be installed (it will be loaded
		237	automatically when you try to create a TLS handle).
		238
		239	Unlike TCP, TLS has a server and client side: for the TLS server side, use
		240	C<accept>, and for the TLS client side of a connection, use C<connect>
		241	mode.
		242
		243	You can also provide your own TLS connection object, but you have
		244	to make sure that you call either C<Net::SSLeay::set_connect_state>
		245	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		246	AnyEvent::Handle.
		247
		248	See the C<starttls> method for when need to start TLS negotiation later.
		249
		250	=item tls_ctx => $ssl_ctx
		251
		252	Use the given Net::SSLeay::CTX object to create the new TLS connection
		253	(unless a connection object was specified directly). If this parameter is
		254	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		255
		256	=item json => JSON or JSON::XS object
		257
		258	This is the json coder object used by the C<json> read and write types.
		259
		260	If you don't supply it, then AnyEvent::Handle will create and use a
		261	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		262	texts.
		263
		264	Note that you are responsible to depend on the JSON module if you want to
		265	use this functionality, as AnyEvent does not have a dependency itself.
		266
		267	=item filter_r => $cb
		268
		269	=item filter_w => $cb
		270
		271	These exist, but are undocumented at this time.
		272
138	=back	273	=back
139		274
140	=cut	275	=cut
141		276
142	sub new {	277	sub new {
…		…
146		281
147	$self->{fh} or Carp::croak "mandatory argument fh is missing";	282	$self->{fh} or Carp::croak "mandatory argument fh is missing";
148		283
149	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	284	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
150		285
151	$self->on_eof ((delete $self->{on_eof} ) or Carp::croak "mandatory argument on_eof is missing");	286	if ($self->{tls}) {
		287	require Net::SSLeay;
		288	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		289	}
152		290
153	$self->on_error (delete $self->{on_error}) if $self->{on_error};	291	$self->{_activity} = AnyEvent->now;
		292	$self->_timeout;
		293
154	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	294	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
155	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	295	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
156		296
157	$self->start_read;	297	$self->start_read
		298	if $self->{on_read};
158		299
159	$self	300	$self
160	}	301	}
161		302
162	sub _shutdown {	303	sub _shutdown {
163	my ($self) = @_;	304	my ($self) = @_;
164		305
		306	delete $self->{_tw};
165	delete $self->{rw};	307	delete $self->{_rw};
166	delete $self->{ww};	308	delete $self->{_ww};
167	delete $self->{fh};	309	delete $self->{fh};
168	}
169		310
		311	$self->stoptls;
		312
		313	delete $self->{on_read};
		314	delete $self->{_queue};
		315	}
		316
170	sub error {	317	sub _error {
171	my ($self) = @_;	318	my ($self, $errno, $fatal) = @_;
172		319
173	{
174	local $!;
175	$self->_shutdown;	320	$self->_shutdown
176	}	321	if $fatal;
		322
		323	$! = $errno;
177		324
178	if ($self->{on_error}) {	325	if ($self->{on_error}) {
179	$self->{on_error}($self);	326	$self->{on_error}($self, $fatal);
180	} else {	327	} else {
181	die "AnyEvent::Handle uncaught fatal error: $!";	328	Carp::croak "AnyEvent::Handle uncaught error: $!";
182	}	329	}
183	}	330	}
184		331
185	=item $fh = $handle->fh	332	=item $fh = $handle->fh
186		333
187	This method returns the filehandle of the L<AnyEvent::Handle> object.	334	This method returns the file handle of the L<AnyEvent::Handle> object.
188		335
189	=cut	336	=cut
190		337
191	sub fh { $_[0]->{fh} }	338	sub fh { $_[0]{fh} }
192		339
193	=item $handle->on_error ($cb)	340	=item $handle->on_error ($cb)
194		341
195	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	342	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
196		343
…		…
208		355
209	sub on_eof {	356	sub on_eof {
210	$_[0]{on_eof} = $_[1];	357	$_[0]{on_eof} = $_[1];
211	}	358	}
212		359
		360	=item $handle->on_timeout ($cb)
		361
		362	Replace the current C<on_timeout> callback, or disables the callback
		363	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		364	argument.
		365
		366	=cut
		367
		368	sub on_timeout {
		369	$_[0]{on_timeout} = $_[1];
		370	}
		371
		372	=item $handle->autocork ($boolean)
		373
		374	Enables or disables the current autocork behaviour (see C<autocork>
		375	constructor argument).
		376
		377	=cut
		378
		379	=item $handle->no_delay ($boolean)
		380
		381	Enables or disables the C<no_delay> setting (see constructor argument of
		382	the same name for details).
		383
		384	=cut
		385
		386	sub no_delay {
		387	$_[0]{no_delay} = $_[1];
		388
		389	eval {
		390	local $SIG{__DIE__};
		391	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		392	};
		393	}
		394
		395	#############################################################################
		396
		397	=item $handle->timeout ($seconds)
		398
		399	Configures (or disables) the inactivity timeout.
		400
		401	=cut
		402
		403	sub timeout {
		404	my ($self, $timeout) = @_;
		405
		406	$self->{timeout} = $timeout;
		407	$self->_timeout;
		408	}
		409
		410	# reset the timeout watcher, as neccessary
		411	# also check for time-outs
		412	sub _timeout {
		413	my ($self) = @_;
		414
		415	if ($self->{timeout}) {
		416	my $NOW = AnyEvent->now;
		417
		418	# when would the timeout trigger?
		419	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		420
		421	# now or in the past already?
		422	if ($after <= 0) {
		423	$self->{_activity} = $NOW;
		424
		425	if ($self->{on_timeout}) {
		426	$self->{on_timeout}($self);
		427	} else {
		428	$self->_error (&Errno::ETIMEDOUT);
		429	}
		430
		431	# callback could have changed timeout value, optimise
		432	return unless $self->{timeout};
		433
		434	# calculate new after
		435	$after = $self->{timeout};
		436	}
		437
		438	Scalar::Util::weaken $self;
		439	return unless $self; # ->error could have destroyed $self
		440
		441	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		442	delete $self->{_tw};
		443	$self->_timeout;
		444	});
		445	} else {
		446	delete $self->{_tw};
		447	}
		448	}
		449
213	#############################################################################	450	#############################################################################
214		451
215	=back	452	=back
216		453
217	=head2 WRITE QUEUE	454	=head2 WRITE QUEUE
…		…
220	for reading.	457	for reading.
221		458
222	The write queue is very simple: you can add data to its end, and	459	The write queue is very simple: you can add data to its end, and
223	AnyEvent::Handle will automatically try to get rid of it for you.	460	AnyEvent::Handle will automatically try to get rid of it for you.
224		461
225	When data could be writtena nd the write buffer is shorter then the low	462	When data could be written and the write buffer is shorter then the low
226	water mark, the C<on_drain> callback will be invoked.	463	water mark, the C<on_drain> callback will be invoked.
227		464
228	=over 4	465	=over 4
229		466
230	=item $handle->on_drain ($cb)	467	=item $handle->on_drain ($cb)
…		…
249	want (only limited by the available memory), as C<AnyEvent::Handle>	486	want (only limited by the available memory), as C<AnyEvent::Handle>
250	buffers it independently of the kernel.	487	buffers it independently of the kernel.
251		488
252	=cut	489	=cut
253		490
254	sub push_write {	491	sub _drain_wbuf {
255	my ($self, $data) = @_;	492	my ($self) = @_;
256		493
257	$self->{wbuf} .= $data;	494	if (!$self->{_ww} && length $self->{wbuf}) {
258		495
259	unless ($self->{ww}) {
260	Scalar::Util::weaken $self;	496	Scalar::Util::weaken $self;
		497
261	my $cb = sub {	498	my $cb = sub {
262	my $len = syswrite $self->{fh}, $self->{wbuf};	499	my $len = syswrite $self->{fh}, $self->{wbuf};
263		500
264	if ($len > 0) {	501	if ($len >= 0) {
265	substr $self->{wbuf}, 0, $len, "";	502	substr $self->{wbuf}, 0, $len, "";
266		503
		504	$self->{_activity} = AnyEvent->now;
267		505
268	$self->{on_drain}($self)	506	$self->{on_drain}($self)
269	if $self->{low_water_mark} >= length $self->{wbuf}	507	if $self->{low_water_mark} >= length $self->{wbuf}
270	&& $self->{on_drain};	508	&& $self->{on_drain};
271		509
272	delete $self->{ww} unless length $self->{wbuf};	510	delete $self->{_ww} unless length $self->{wbuf};
273	} elsif ($! != EAGAIN && $! != EINTR) {	511	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
274	$self->error;	512	$self->_error ($!, 1);
275	}	513	}
276	};	514	};
277		515
		516	# try to write data immediately
		517	$cb->() unless $self->{autocork};
		518
		519	# if still data left in wbuf, we need to poll
278	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	520	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
279		521	if length $self->{wbuf};
280	$cb->($self);
281	};	522	};
282	}	523	}
		524
		525	our %WH;
		526
		527	sub register_write_type($$) {
		528	$WH{$_[0]} = $_[1];
		529	}
		530
		531	sub push_write {
		532	my $self = shift;
		533
		534	if (@_ > 1) {
		535	my $type = shift;
		536
		537	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		538	->($self, @_);
		539	}
		540
		541	if ($self->{filter_w}) {
		542	$self->{filter_w}($self, \$_[0]);
		543	} else {
		544	$self->{wbuf} .= $_[0];
		545	$self->_drain_wbuf;
		546	}
		547	}
		548
		549	=item $handle->push_write (type => @args)
		550
		551	Instead of formatting your data yourself, you can also let this module do
		552	the job by specifying a type and type-specific arguments.
		553
		554	Predefined types are (if you have ideas for additional types, feel free to
		555	drop by and tell us):
		556
		557	=over 4
		558
		559	=item netstring => $string
		560
		561	Formats the given value as netstring
		562	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		563
		564	=cut
		565
		566	register_write_type netstring => sub {
		567	my ($self, $string) = @_;
		568
		569	sprintf "%d:%s,", (length $string), $string
		570	};
		571
		572	=item packstring => $format, $data
		573
		574	An octet string prefixed with an encoded length. The encoding C<$format>
		575	uses the same format as a Perl C<pack> format, but must specify a single
		576	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		577	optional C<!>, C<< < >> or C<< > >> modifier).
		578
		579	=cut
		580
		581	register_write_type packstring => sub {
		582	my ($self, $format, $string) = @_;
		583
		584	pack "$format/a*", $string
		585	};
		586
		587	=item json => $array_or_hashref
		588
		589	Encodes the given hash or array reference into a JSON object. Unless you
		590	provide your own JSON object, this means it will be encoded to JSON text
		591	in UTF-8.
		592
		593	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		594	one end of a handle and read them at the other end without using any
		595	additional framing.
		596
		597	The generated JSON text is guaranteed not to contain any newlines: While
		598	this module doesn't need delimiters after or between JSON texts to be
		599	able to read them, many other languages depend on that.
		600
		601	A simple RPC protocol that interoperates easily with others is to send
		602	JSON arrays (or objects, although arrays are usually the better choice as
		603	they mimic how function argument passing works) and a newline after each
		604	JSON text:
		605
		606	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		607	$handle->push_write ("\012");
		608
		609	An AnyEvent::Handle receiver would simply use the C<json> read type and
		610	rely on the fact that the newline will be skipped as leading whitespace:
		611
		612	$handle->push_read (json => sub { my $array = $_[1]; ... });
		613
		614	Other languages could read single lines terminated by a newline and pass
		615	this line into their JSON decoder of choice.
		616
		617	=cut
		618
		619	register_write_type json => sub {
		620	my ($self, $ref) = @_;
		621
		622	require JSON;
		623
		624	$self->{json} ? $self->{json}->encode ($ref)
		625	: JSON::encode_json ($ref)
		626	};
		627
		628	=item storable => $reference
		629
		630	Freezes the given reference using L<Storable> and writes it to the
		631	handle. Uses the C<nfreeze> format.
		632
		633	=cut
		634
		635	register_write_type storable => sub {
		636	my ($self, $ref) = @_;
		637
		638	require Storable;
		639
		640	pack "w/a*", Storable::nfreeze ($ref)
		641	};
		642
		643	=back
		644
		645	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		646
		647	This function (not method) lets you add your own types to C<push_write>.
		648	Whenever the given C<type> is used, C<push_write> will invoke the code
		649	reference with the handle object and the remaining arguments.
		650
		651	The code reference is supposed to return a single octet string that will
		652	be appended to the write buffer.
		653
		654	Note that this is a function, and all types registered this way will be
		655	global, so try to use unique names.
		656
		657	=cut
283		658
284	#############################################################################	659	#############################################################################
285		660
286	=back	661	=back
287		662
…		…
294	ways, the "simple" way, using only C<on_read> and the "complex" way, using	669	ways, the "simple" way, using only C<on_read> and the "complex" way, using
295	a queue.	670	a queue.
296		671
297	In the simple case, you just install an C<on_read> callback and whenever	672	In the simple case, you just install an C<on_read> callback and whenever
298	new data arrives, it will be called. You can then remove some data (if	673	new data arrives, it will be called. You can then remove some data (if
299	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	674	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
300	or not.	675	leave the data there if you want to accumulate more (e.g. when only a
		676	partial message has been received so far).
301		677
302	In the more complex case, you want to queue multiple callbacks. In this	678	In the more complex case, you want to queue multiple callbacks. In this
303	case, AnyEvent::Handle will call the first queued callback each time new	679	case, AnyEvent::Handle will call the first queued callback each time new
304	data arrives and removes it when it has done its job (see C<push_read>,	680	data arrives (also the first time it is queued) and removes it when it has
305	below).	681	done its job (see C<push_read>, below).
306		682
307	This way you can, for example, push three line-reads, followed by reading	683	This way you can, for example, push three line-reads, followed by reading
308	a chunk of data, and AnyEvent::Handle will execute them in order.	684	a chunk of data, and AnyEvent::Handle will execute them in order.
309		685
310	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	686	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
311	the specified number of bytes which give an XML datagram.	687	the specified number of bytes which give an XML datagram.
312		688
313	# in the default state, expect some header bytes	689	# in the default state, expect some header bytes
314	$handle->on_read (sub {	690	$handle->on_read (sub {
315	# some data is here, now queue the length-header-read (4 octets)	691	# some data is here, now queue the length-header-read (4 octets)
316	shift->unshift_read_chunk (4, sub {	692	shift->unshift_read (chunk => 4, sub {
317	# header arrived, decode	693	# header arrived, decode
318	my $len = unpack "N", $_[1];	694	my $len = unpack "N", $_[1];
319		695
320	# now read the payload	696	# now read the payload
321	shift->unshift_read_chunk ($len, sub {	697	shift->unshift_read (chunk => $len, sub {
322	my $xml = $_[1];	698	my $xml = $_[1];
323	# handle xml	699	# handle xml
324	});	700	});
325	});	701	});
326	});	702	});
327		703
328	Example 2: Implement a client for a protocol that replies either with	704	Example 2: Implement a client for a protocol that replies either with "OK"
329	"OK" and another line or "ERROR" for one request, and 64 bytes for the	705	and another line or "ERROR" for the first request that is sent, and 64
330	second request. Due tot he availability of a full queue, we can just	706	bytes for the second request. Due to the availability of a queue, we can
331	pipeline sending both requests and manipulate the queue as necessary in	707	just pipeline sending both requests and manipulate the queue as necessary
332	the callbacks:	708	in the callbacks.
333		709
334	# request one	710	When the first callback is called and sees an "OK" response, it will
		711	C<unshift> another line-read. This line-read will be queued I<before> the
		712	64-byte chunk callback.
		713
		714	# request one, returns either "OK + extra line" or "ERROR"
335	$handle->push_write ("request 1\015\012");	715	$handle->push_write ("request 1\015\012");
336		716
337	# we expect "ERROR" or "OK" as response, so push a line read	717	# we expect "ERROR" or "OK" as response, so push a line read
338	$handle->push_read_line (sub {	718	$handle->push_read (line => sub {
339	# if we got an "OK", we have to _prepend_ another line,	719	# if we got an "OK", we have to _prepend_ another line,
340	# so it will be read before the second request reads its 64 bytes	720	# so it will be read before the second request reads its 64 bytes
341	# which are already in the queue when this callback is called	721	# which are already in the queue when this callback is called
342	# we don't do this in case we got an error	722	# we don't do this in case we got an error
343	if ($_[1] eq "OK") {	723	if ($_[1] eq "OK") {
344	$_[0]->unshift_read_line (sub {	724	$_[0]->unshift_read (line => sub {
345	my $response = $_[1];	725	my $response = $_[1];
346	...	726	...
347	});	727	});
348	}	728	}
349	});	729	});
350		730
351	# request two	731	# request two, simply returns 64 octets
352	$handle->push_write ("request 2\015\012");	732	$handle->push_write ("request 2\015\012");
353		733
354	# simply read 64 bytes, always	734	# simply read 64 bytes, always
355	$handle->push_read_chunk (64, sub {	735	$handle->push_read (chunk => 64, sub {
356	my $response = $_[1];	736	my $response = $_[1];
357	...	737	...
358	});	738	});
359		739
360	=over 4	740	=over 4
…		…
362	=cut	742	=cut
363		743
364	sub _drain_rbuf {	744	sub _drain_rbuf {
365	my ($self) = @_;	745	my ($self) = @_;
366		746
367	return if $self->{in_drain};
368	local $self->{in_drain} = 1;	747	local $self->{_in_drain} = 1;
369		748
		749	if (
		750	defined $self->{rbuf_max}
		751	&& $self->{rbuf_max} < length $self->{rbuf}
		752	) {
		753	$self->_error (&Errno::ENOSPC, 1), return;
		754	}
		755
		756	while () {
370	while (my $len = length $self->{rbuf}) {	757	my $len = length $self->{rbuf};
371	no strict 'refs';	758
372	if (my $cb = shift @{ $self->{queue} }) {	759	if (my $cb = shift @{ $self->{_queue} }) {
373	if (!$cb->($self)) {	760	unless ($cb->($self)) {
374	if ($self->{eof}) {	761	if ($self->{_eof}) {
375	# no progress can be made (not enough data and no data forthcoming)	762	# no progress can be made (not enough data and no data forthcoming)
376	$! = &Errno::EPIPE; return $self->error;	763	$self->_error (&Errno::EPIPE, 1), return;
377	}	764	}
378		765
379	unshift @{ $self->{queue} }, $cb;	766	unshift @{ $self->{_queue} }, $cb;
380	return;	767	last;
381	}	768	}
382	} elsif ($self->{on_read}) {	769	} elsif ($self->{on_read}) {
		770	last unless $len;
		771
383	$self->{on_read}($self);	772	$self->{on_read}($self);
384		773
385	if (	774	if (
386	$self->{eof} # if no further data will arrive
387	&& $len == length $self->{rbuf} # and no data has been consumed	775	$len == length $self->{rbuf} # if no data has been consumed
388	&& !@{ $self->{queue} } # and the queue is still empty	776	&& !@{ $self->{_queue} } # and the queue is still empty
389	&& $self->{on_read} # and we still want to read data	777	&& $self->{on_read} # but we still have on_read
390	) {	778	) {
		779	# no further data will arrive
391	# then no progress can be made	780	# so no progress can be made
392	$! = &Errno::EPIPE; return $self->error;	781	$self->_error (&Errno::EPIPE, 1), return
		782	if $self->{_eof};
		783
		784	last; # more data might arrive
393	}	785	}
394	} else {	786	} else {
395	# read side becomes idle	787	# read side becomes idle
396	delete $self->{rw};	788	delete $self->{_rw};
397	return;	789	last;
398	}	790	}
399	}	791	}
400		792
401	if ($self->{eof}) {	793	if ($self->{_eof}) {
402	$self->_shutdown;	794	if ($self->{on_eof}) {
403	$self->{on_eof}($self);	795	$self->{on_eof}($self)
		796	} else {
		797	$self->_error (0, 1);
		798	}
		799	}
		800
		801	# may need to restart read watcher
		802	unless ($self->{_rw}) {
		803	$self->start_read
		804	if $self->{on_read} || @{ $self->{_queue} };
404	}	805	}
405	}	806	}
406		807
407	=item $handle->on_read ($cb)	808	=item $handle->on_read ($cb)
408		809
…		…
414		815
415	sub on_read {	816	sub on_read {
416	my ($self, $cb) = @_;	817	my ($self, $cb) = @_;
417		818
418	$self->{on_read} = $cb;	819	$self->{on_read} = $cb;
		820	$self->_drain_rbuf if $cb && !$self->{_in_drain};
419	}	821	}
420		822
421	=item $handle->rbuf	823	=item $handle->rbuf
422		824
423	Returns the read buffer (as a modifiable lvalue).	825	Returns the read buffer (as a modifiable lvalue).
…		…
442	Append the given callback to the end of the queue (C<push_read>) or	844	Append the given callback to the end of the queue (C<push_read>) or
443	prepend it (C<unshift_read>).	845	prepend it (C<unshift_read>).
444		846
445	The callback is called each time some additional read data arrives.	847	The callback is called each time some additional read data arrives.
446		848
447	It must check wether enough data is in the read buffer already.	849	It must check whether enough data is in the read buffer already.
448		850
449	If not enough data is available, it must return the empty list or a false	851	If not enough data is available, it must return the empty list or a false
450	value, in which case it will be called repeatedly until enough data is	852	value, in which case it will be called repeatedly until enough data is
451	available (or an error condition is detected).	853	available (or an error condition is detected).
452		854
…		…
454	interested in (which can be none at all) and return a true value. After returning	856	interested in (which can be none at all) and return a true value. After returning
455	true, it will be removed from the queue.	857	true, it will be removed from the queue.
456		858
457	=cut	859	=cut
458		860
		861	our %RH;
		862
		863	sub register_read_type($$) {
		864	$RH{$_[0]} = $_[1];
		865	}
		866
459	sub push_read {	867	sub push_read {
460	my ($self, $cb) = @_;	868	my $self = shift;
		869	my $cb = pop;
461		870
		871	if (@_) {
		872	my $type = shift;
		873
		874	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		875	->($self, $cb, @_);
		876	}
		877
462	push @{ $self->{queue} }, $cb;	878	push @{ $self->{_queue} }, $cb;
463	$self->_drain_rbuf;	879	$self->_drain_rbuf unless $self->{_in_drain};
464	}	880	}
465		881
466	sub unshift_read {	882	sub unshift_read {
467	my ($self, $cb) = @_;	883	my $self = shift;
		884	my $cb = pop;
468		885
		886	if (@_) {
		887	my $type = shift;
		888
		889	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		890	->($self, $cb, @_);
		891	}
		892
		893
469	push @{ $self->{queue} }, $cb;	894	unshift @{ $self->{_queue} }, $cb;
470	$self->_drain_rbuf;	895	$self->_drain_rbuf unless $self->{_in_drain};
471	}	896	}
472		897
473	=item $handle->push_read_chunk ($len, $cb->($self, $data))	898	=item $handle->push_read (type => @args, $cb)
474		899
475	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	900	=item $handle->unshift_read (type => @args, $cb)
476		901
477	Append the given callback to the end of the queue (C<push_read_chunk>) or	902	Instead of providing a callback that parses the data itself you can chose
478	prepend it (C<unshift_read_chunk>).	903	between a number of predefined parsing formats, for chunks of data, lines
		904	etc.
479		905
480	The callback will be called only once C<$len> bytes have been read, and	906	Predefined types are (if you have ideas for additional types, feel free to
481	these C<$len> bytes will be passed to the callback.	907	drop by and tell us):
482		908
483	=cut	909	=over 4
484		910
485	sub _read_chunk($$) {	911	=item chunk => $octets, $cb->($handle, $data)
		912
		913	Invoke the callback only once C<$octets> bytes have been read. Pass the
		914	data read to the callback. The callback will never be called with less
		915	data.
		916
		917	Example: read 2 bytes.
		918
		919	$handle->push_read (chunk => 2, sub {
		920	warn "yay ", unpack "H*", $_[1];
		921	});
		922
		923	=cut
		924
		925	register_read_type chunk => sub {
486	my ($self, $len, $cb) = @_;	926	my ($self, $cb, $len) = @_;
487		927
488	sub {	928	sub {
489	$len <= length $_[0]{rbuf} or return;	929	$len <= length $_[0]{rbuf} or return;
490	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	930	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
491	1	931	1
492	}	932	}
493	}	933	};
494		934
495	sub push_read_chunk {	935	=item line => [$eol, ]$cb->($handle, $line, $eol)
496	$_[0]->push_read (&_read_chunk);
497	}
498
499
500	sub unshift_read_chunk {
501	$_[0]->unshift_read (&_read_chunk);
502	}
503
504	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
505
506	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
507
508	Append the given callback to the end of the queue (C<push_read_line>) or
509	prepend it (C<unshift_read_line>).
510		936
511	The callback will be called only once a full line (including the end of	937	The callback will be called only once a full line (including the end of
512	line marker, C<$eol>) has been read. This line (excluding the end of line	938	line marker, C<$eol>) has been read. This line (excluding the end of line
513	marker) will be passed to the callback as second argument (C<$line>), and	939	marker) will be passed to the callback as second argument (C<$line>), and
514	the end of line marker as the third argument (C<$eol>).	940	the end of line marker as the third argument (C<$eol>).
…		…
525	Partial lines at the end of the stream will never be returned, as they are	951	Partial lines at the end of the stream will never be returned, as they are
526	not marked by the end of line marker.	952	not marked by the end of line marker.
527		953
528	=cut	954	=cut
529		955
530	sub _read_line($$) {	956	register_read_type line => sub {
531	my $self = shift;	957	my ($self, $cb, $eol) = @_;
532	my $cb = pop;
533	my $eol = @_ ? shift : qr|(\015?\012)|;
534	my $pos;
535		958
		959	if (@_ < 3) {
		960	# this is more than twice as fast as the generic code below
		961	sub {
		962	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		963
		964	$cb->($_[0], $1, $2);
		965	1
		966	}
		967	} else {
536	$eol = qr|(\Q$eol\E)| unless ref $eol;	968	$eol = quotemeta $eol unless ref $eol;
537	$eol = qr|^(.*?)($eol)|;	969	$eol = qr|^(.*?)($eol)|s;
		970
		971	sub {
		972	$_[0]{rbuf} =~ s/$eol// or return;
		973
		974	$cb->($_[0], $1, $2);
		975	1
		976	}
		977	}
		978	};
		979
		980	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		981
		982	Makes a regex match against the regex object C<$accept> and returns
		983	everything up to and including the match.
		984
		985	Example: read a single line terminated by '\n'.
		986
		987	$handle->push_read (regex => qr<\n>, sub { ... });
		988
		989	If C<$reject> is given and not undef, then it determines when the data is
		990	to be rejected: it is matched against the data when the C<$accept> regex
		991	does not match and generates an C<EBADMSG> error when it matches. This is
		992	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		993	receive buffer overflow).
		994
		995	Example: expect a single decimal number followed by whitespace, reject
		996	anything else (not the use of an anchor).
		997
		998	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		999
		1000	If C<$skip> is given and not C<undef>, then it will be matched against
		1001	the receive buffer when neither C<$accept> nor C<$reject> match,
		1002	and everything preceding and including the match will be accepted
		1003	unconditionally. This is useful to skip large amounts of data that you
		1004	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1005	have to start matching from the beginning. This is purely an optimisation
		1006	and is usually worth only when you expect more than a few kilobytes.
		1007
		1008	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1009	expect the header to be very large (it isn't in practise, but...), we use
		1010	a skip regex to skip initial portions. The skip regex is tricky in that
		1011	it only accepts something not ending in either \015 or \012, as these are
		1012	required for the accept regex.
		1013
		1014	$handle->push_read (regex =>
		1015	qr<\015\012\015\012>,
		1016	undef, # no reject
		1017	qr<^.*[^\015\012]>,
		1018	sub { ... });
		1019
		1020	=cut
		1021
		1022	register_read_type regex => sub {
		1023	my ($self, $cb, $accept, $reject, $skip) = @_;
		1024
		1025	my $data;
		1026	my $rbuf = \$self->{rbuf};
538		1027
539	sub {	1028	sub {
540	$_[0]{rbuf} =~ s/$eol// or return;	1029	# accept
		1030	if ($$rbuf =~ $accept) {
		1031	$data .= substr $$rbuf, 0, $+[0], "";
		1032	$cb->($self, $data);
		1033	return 1;
		1034	}
		1035
		1036	# reject
		1037	if ($reject && $$rbuf =~ $reject) {
		1038	$self->_error (&Errno::EBADMSG);
		1039	}
541		1040
542	$cb->($_[0], $1, $2);	1041	# skip
		1042	if ($skip && $$rbuf =~ $skip) {
		1043	$data .= substr $$rbuf, 0, $+[0], "";
		1044	}
		1045
		1046	()
		1047	}
		1048	};
		1049
		1050	=item netstring => $cb->($handle, $string)
		1051
		1052	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1053
		1054	Throws an error with C<$!> set to EBADMSG on format violations.
		1055
		1056	=cut
		1057
		1058	register_read_type netstring => sub {
		1059	my ($self, $cb) = @_;
		1060
		1061	sub {
		1062	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1063	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1064	$self->_error (&Errno::EBADMSG);
		1065	}
		1066	return;
		1067	}
		1068
		1069	my $len = $1;
		1070
		1071	$self->unshift_read (chunk => $len, sub {
		1072	my $string = $_[1];
		1073	$_[0]->unshift_read (chunk => 1, sub {
		1074	if ($_[1] eq ",") {
		1075	$cb->($_[0], $string);
		1076	} else {
		1077	$self->_error (&Errno::EBADMSG);
		1078	}
		1079	});
		1080	});
		1081
543	1	1082	1
544	}	1083	}
545	}	1084	};
546		1085
547	sub push_read_line {	1086	=item packstring => $format, $cb->($handle, $string)
548	$_[0]->push_read (&_read_line);
549	}
550		1087
551	sub unshift_read_line {	1088	An octet string prefixed with an encoded length. The encoding C<$format>
552	$_[0]->unshift_read (&_read_line);	1089	uses the same format as a Perl C<pack> format, but must specify a single
553	}	1090	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1091	optional C<!>, C<< < >> or C<< > >> modifier).
		1092
		1093	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1094
		1095	Example: read a block of data prefixed by its length in BER-encoded
		1096	format (very efficient).
		1097
		1098	$handle->push_read (packstring => "w", sub {
		1099	my ($handle, $data) = @_;
		1100	});
		1101
		1102	=cut
		1103
		1104	register_read_type packstring => sub {
		1105	my ($self, $cb, $format) = @_;
		1106
		1107	sub {
		1108	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1109	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1110	or return;
		1111
		1112	$format = length pack $format, $len;
		1113
		1114	# bypass unshift if we already have the remaining chunk
		1115	if ($format + $len <= length $_[0]{rbuf}) {
		1116	my $data = substr $_[0]{rbuf}, $format, $len;
		1117	substr $_[0]{rbuf}, 0, $format + $len, "";
		1118	$cb->($_[0], $data);
		1119	} else {
		1120	# remove prefix
		1121	substr $_[0]{rbuf}, 0, $format, "";
		1122
		1123	# read remaining chunk
		1124	$_[0]->unshift_read (chunk => $len, $cb);
		1125	}
		1126
		1127	1
		1128	}
		1129	};
		1130
		1131	=item json => $cb->($handle, $hash_or_arrayref)
		1132
		1133	Reads a JSON object or array, decodes it and passes it to the callback.
		1134
		1135	If a C<json> object was passed to the constructor, then that will be used
		1136	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1137
		1138	This read type uses the incremental parser available with JSON version
		1139	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1140	dependency on your own: this module will load the JSON module, but
		1141	AnyEvent does not depend on it itself.
		1142
		1143	Since JSON texts are fully self-delimiting, the C<json> read and write
		1144	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1145	the C<json> write type description, above, for an actual example.
		1146
		1147	=cut
		1148
		1149	register_read_type json => sub {
		1150	my ($self, $cb) = @_;
		1151
		1152	require JSON;
		1153
		1154	my $data;
		1155	my $rbuf = \$self->{rbuf};
		1156
		1157	my $json = $self->{json} ||= JSON->new->utf8;
		1158
		1159	sub {
		1160	my $ref = $json->incr_parse ($self->{rbuf});
		1161
		1162	if ($ref) {
		1163	$self->{rbuf} = $json->incr_text;
		1164	$json->incr_text = "";
		1165	$cb->($self, $ref);
		1166
		1167	1
		1168	} else {
		1169	$self->{rbuf} = "";
		1170	()
		1171	}
		1172	}
		1173	};
		1174
		1175	=item storable => $cb->($handle, $ref)
		1176
		1177	Deserialises a L<Storable> frozen representation as written by the
		1178	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1179	data).
		1180
		1181	Raises C<EBADMSG> error if the data could not be decoded.
		1182
		1183	=cut
		1184
		1185	register_read_type storable => sub {
		1186	my ($self, $cb) = @_;
		1187
		1188	require Storable;
		1189
		1190	sub {
		1191	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1192	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1193	or return;
		1194
		1195	my $format = length pack "w", $len;
		1196
		1197	# bypass unshift if we already have the remaining chunk
		1198	if ($format + $len <= length $_[0]{rbuf}) {
		1199	my $data = substr $_[0]{rbuf}, $format, $len;
		1200	substr $_[0]{rbuf}, 0, $format + $len, "";
		1201	$cb->($_[0], Storable::thaw ($data));
		1202	} else {
		1203	# remove prefix
		1204	substr $_[0]{rbuf}, 0, $format, "";
		1205
		1206	# read remaining chunk
		1207	$_[0]->unshift_read (chunk => $len, sub {
		1208	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1209	$cb->($_[0], $ref);
		1210	} else {
		1211	$self->_error (&Errno::EBADMSG);
		1212	}
		1213	});
		1214	}
		1215
		1216	1
		1217	}
		1218	};
		1219
		1220	=back
		1221
		1222	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1223
		1224	This function (not method) lets you add your own types to C<push_read>.
		1225
		1226	Whenever the given C<type> is used, C<push_read> will invoke the code
		1227	reference with the handle object, the callback and the remaining
		1228	arguments.
		1229
		1230	The code reference is supposed to return a callback (usually a closure)
		1231	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1232
		1233	It should invoke the passed callback when it is done reading (remember to
		1234	pass C<$handle> as first argument as all other callbacks do that).
		1235
		1236	Note that this is a function, and all types registered this way will be
		1237	global, so try to use unique names.
		1238
		1239	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1240	search for C<register_read_type>)).
554		1241
555	=item $handle->stop_read	1242	=item $handle->stop_read
556		1243
557	=item $handle->start_read	1244	=item $handle->start_read
558		1245
559	In rare cases you actually do not want to read anything form the	1246	In rare cases you actually do not want to read anything from the
560	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1247	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
561	any queued callbacks will be executed then. To start readign again, call	1248	any queued callbacks will be executed then. To start reading again, call
562	C<start_read>.	1249	C<start_read>.
		1250
		1251	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1252	you change the C<on_read> callback or push/unshift a read callback, and it
		1253	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1254	there are any read requests in the queue.
563		1255
564	=cut	1256	=cut
565		1257
566	sub stop_read {	1258	sub stop_read {
567	my ($self) = @_;	1259	my ($self) = @_;
568		1260
569	delete $self->{rw};	1261	delete $self->{_rw};
570	}	1262	}
571		1263
572	sub start_read {	1264	sub start_read {
573	my ($self) = @_;	1265	my ($self) = @_;
574		1266
575	unless ($self->{rw} || $self->{eof}) {	1267	unless ($self->{_rw} || $self->{_eof}) {
576	Scalar::Util::weaken $self;	1268	Scalar::Util::weaken $self;
577		1269
578	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1270	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1271	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
579	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1272	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
580		1273
581	if ($len > 0) {	1274	if ($len > 0) {
582	if (defined $self->{rbuf_max}) {	1275	$self->{_activity} = AnyEvent->now;
583	if ($self->{rbuf_max} < length $self->{rbuf}) {	1276
584	$! = &Errno::ENOSPC; return $self->error;	1277	$self->{filter_r}
585	}	1278	? $self->{filter_r}($self, $rbuf)
586	}	1279	: $self->{_in_drain} || $self->_drain_rbuf;
587		1280
588	} elsif (defined $len) {	1281	} elsif (defined $len) {
589	$self->{eof} = 1;
590	delete $self->{rw};	1282	delete $self->{_rw};
		1283	$self->{_eof} = 1;
		1284	$self->_drain_rbuf unless $self->{_in_drain};
591		1285
592	} elsif ($! != EAGAIN && $! != EINTR) {	1286	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
593	return $self->error;	1287	return $self->_error ($!, 1);
594	}	1288	}
595
596	$self->_drain_rbuf;
597	});	1289	});
598	}	1290	}
599	}	1291	}
600		1292
		1293	sub _dotls {
		1294	my ($self) = @_;
		1295
		1296	my $buf;
		1297
		1298	if (length $self->{_tls_wbuf}) {
		1299	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1300	substr $self->{_tls_wbuf}, 0, $len, "";
		1301	}
		1302	}
		1303
		1304	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1305	$self->{wbuf} .= $buf;
		1306	$self->_drain_wbuf;
		1307	}
		1308
		1309	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1310	if (length $buf) {
		1311	$self->{rbuf} .= $buf;
		1312	$self->_drain_rbuf unless $self->{_in_drain};
		1313	} else {
		1314	# let's treat SSL-eof as we treat normal EOF
		1315	$self->{_eof} = 1;
		1316	$self->_shutdown;
		1317	return;
		1318	}
		1319	}
		1320
		1321	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1322
		1323	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1324	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1325	return $self->_error ($!, 1);
		1326	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1327	return $self->_error (&Errno::EIO, 1);
		1328	}
		1329
		1330	# all others are fine for our purposes
		1331	}
		1332	}
		1333
		1334	=item $handle->starttls ($tls[, $tls_ctx])
		1335
		1336	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1337	object is created, you can also do that at a later time by calling
		1338	C<starttls>.
		1339
		1340	The first argument is the same as the C<tls> constructor argument (either
		1341	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1342
		1343	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1344	used when AnyEvent::Handle has to create its own TLS connection object.
		1345
		1346	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1347	call and can be used or changed to your liking. Note that the handshake
		1348	might have already started when this function returns.
		1349
		1350	=cut
		1351
		1352	sub starttls {
		1353	my ($self, $ssl, $ctx) = @_;
		1354
		1355	$self->stoptls;
		1356
		1357	if ($ssl eq "accept") {
		1358	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1359	Net::SSLeay::set_accept_state ($ssl);
		1360	} elsif ($ssl eq "connect") {
		1361	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1362	Net::SSLeay::set_connect_state ($ssl);
		1363	}
		1364
		1365	$self->{tls} = $ssl;
		1366
		1367	# basically, this is deep magic (because SSL_read should have the same issues)
		1368	# but the openssl maintainers basically said: "trust us, it just works".
		1369	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1370	# and mismaintained ssleay-module doesn't even offer them).
		1371	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1372	Net::SSLeay::CTX_set_mode ($self->{tls},
		1373	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1374	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1375
		1376	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1377	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1378
		1379	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1380
		1381	$self->{filter_w} = sub {
		1382	$_[0]{_tls_wbuf} .= ${$_[1]};
		1383	&_dotls;
		1384	};
		1385	$self->{filter_r} = sub {
		1386	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1387	&_dotls;
		1388	};
		1389	}
		1390
		1391	=item $handle->stoptls
		1392
		1393	Destroys the SSL connection, if any. Partial read or write data will be
		1394	lost.
		1395
		1396	=cut
		1397
		1398	sub stoptls {
		1399	my ($self) = @_;
		1400
		1401	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1402
		1403	delete $self->{_rbio};
		1404	delete $self->{_wbio};
		1405	delete $self->{_tls_wbuf};
		1406	delete $self->{filter_r};
		1407	delete $self->{filter_w};
		1408	}
		1409
		1410	sub DESTROY {
		1411	my $self = shift;
		1412
		1413	$self->stoptls;
		1414
		1415	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1416
		1417	if ($linger && length $self->{wbuf}) {
		1418	my $fh = delete $self->{fh};
		1419	my $wbuf = delete $self->{wbuf};
		1420
		1421	my @linger;
		1422
		1423	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1424	my $len = syswrite $fh, $wbuf, length $wbuf;
		1425
		1426	if ($len > 0) {
		1427	substr $wbuf, 0, $len, "";
		1428	} else {
		1429	@linger = (); # end
		1430	}
		1431	});
		1432	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1433	@linger = ();
		1434	});
		1435	}
		1436	}
		1437
		1438	=item AnyEvent::Handle::TLS_CTX
		1439
		1440	This function creates and returns the Net::SSLeay::CTX object used by
		1441	default for TLS mode.
		1442
		1443	The context is created like this:
		1444
		1445	Net::SSLeay::load_error_strings;
		1446	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1447	Net::SSLeay::randomize;
		1448
		1449	my $CTX = Net::SSLeay::CTX_new;
		1450
		1451	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1452
		1453	=cut
		1454
		1455	our $TLS_CTX;
		1456
		1457	sub TLS_CTX() {
		1458	$TLS_CTX || do {
		1459	require Net::SSLeay;
		1460
		1461	Net::SSLeay::load_error_strings ();
		1462	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1463	Net::SSLeay::randomize ();
		1464
		1465	$TLS_CTX = Net::SSLeay::CTX_new ();
		1466
		1467	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1468
		1469	$TLS_CTX
		1470	}
		1471	}
		1472
601	=back	1473	=back
602		1474
		1475	=head1 SUBCLASSING AnyEvent::Handle
		1476
		1477	In many cases, you might want to subclass AnyEvent::Handle.
		1478
		1479	To make this easier, a given version of AnyEvent::Handle uses these
		1480	conventions:
		1481
		1482	=over 4
		1483
		1484	=item * all constructor arguments become object members.
		1485
		1486	At least initially, when you pass a C<tls>-argument to the constructor it
		1487	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1488	mutated later on (for example C<tls> will hold the TLS connection object).
		1489
		1490	=item * other object member names are prefixed with an C<_>.
		1491
		1492	All object members not explicitly documented (internal use) are prefixed
		1493	with an underscore character, so the remaining non-C<_>-namespace is free
		1494	for use for subclasses.
		1495
		1496	=item * all members not documented here and not prefixed with an underscore
		1497	are free to use in subclasses.
		1498
		1499	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1500	member variables, but thats just life, at least it is documented.
		1501
		1502	=back
		1503
603	=head1 AUTHOR	1504	=head1 AUTHOR
604		1505
605	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1506	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
606		1507
607	=cut	1508	=cut

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