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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.16 by root, Fri May 23 05:16:57 2008 UTC vs.
Revision 1.77 by root, Sun Jul 27 07:25:39 2008 UTC

…		…
2		2
3	no warnings;	3	no warnings;
4	use strict;	4	use strict;
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 = 4.22;
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
…		…
72	The filehandle this L<AnyEvent::Handle> object will operate on.	73	The filehandle this L<AnyEvent::Handle> object will operate on.
73		74
74	NOTE: The filehandle will be set to non-blocking (using	75	NOTE: The filehandle will be set to non-blocking (using
75	AnyEvent::Util::fh_nonblocking).	76	AnyEvent::Util::fh_nonblocking).
76		77
77	=item on_eof => $cb->($self)	78	=item on_eof => $cb->($handle)
78		79
79	Set the callback to be called on EOF.	80	Set the callback to be called when an end-of-file condition is detected,
		81	i.e. in the case of a socket, when the other side has closed the
		82	connection cleanly.
80		83
81	While not mandatory, it is highly recommended to set an eof callback,	84	While not mandatory, it is highly recommended to set an eof callback,
82	otherwise you might end up with a closed socket while you are still	85	otherwise you might end up with a closed socket while you are still
83	waiting for data.	86	waiting for data.
84		87
85	=item on_error => $cb->($self)	88	=item on_error => $cb->($handle, $fatal)
86		89
87	This is the fatal error callback, that is called when, well, a fatal error	90	This is the error callback, which is called when, well, some error
88	ocurs, such as not being able to resolve the hostname, failure to connect	91	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	92	connect or a read error.
90		93
91	The object will not be in a usable state when this callback has been	94	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	called.	95	fatal errors the handle object will be shut down and will not be
		96	usable. Non-fatal errors can be retried by simply returning, but it is
		97	recommended to simply ignore this parameter and instead abondon the handle
		98	object when this callback is invoked.
93		99
94	On callback entrance, the value of C<$!> contains the operating system	100	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	101	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		102
97	While not mandatory, it is I<highly> recommended to set this callback, as	103	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	104	you will not be notified of errors otherwise. The default simply calls
99	die.	105	C<croak>.
100		106
101	=item on_read => $cb->($self)	107	=item on_read => $cb->($handle)
102		108
103	This sets the default read callback, which is called when data arrives	109	This sets the default read callback, which is called when data arrives
104	and no read request is in the queue.	110	and no read request is in the queue (unlike read queue callbacks, this
		111	callback will only be called when at least one octet of data is in the
		112	read buffer).
105		113
106	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	114	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107	method or acces sthe C<$self->{rbuf}> member directly.	115	method or access the C<$handle->{rbuf}> member directly.
108		116
109	When an EOF condition is detected then AnyEvent::Handle will first try to	117	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	118	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	119	calling the C<on_eof> callback. If no progress can be made, then a fatal
112	error will be raised (with C<$!> set to C<EPIPE>).	120	error will be raised (with C<$!> set to C<EPIPE>).
113		121
114	=item on_drain => $cb->()	122	=item on_drain => $cb->($handle)
115		123
116	This sets the callback that is called when the write buffer becomes empty	124	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).	125	(or when the callback is set and the buffer is empty already).
118		126
119	To append to the write buffer, use the C<< ->push_write >> method.	127	To append to the write buffer, use the C<< ->push_write >> method.
		128
		129	This callback is useful when you don't want to put all of your write data
		130	into the queue at once, for example, when you want to write the contents
		131	of some file to the socket you might not want to read the whole file into
		132	memory and push it into the queue, but instead only read more data from
		133	the file when the write queue becomes empty.
		134
		135	=item timeout => $fractional_seconds
		136
		137	If non-zero, then this enables an "inactivity" timeout: whenever this many
		138	seconds pass without a successful read or write on the underlying file
		139	handle, the C<on_timeout> callback will be invoked (and if that one is
		140	missing, an C<ETIMEDOUT> error will be raised).
		141
		142	Note that timeout processing is also active when you currently do not have
		143	any outstanding read or write requests: If you plan to keep the connection
		144	idle then you should disable the timout temporarily or ignore the timeout
		145	in the C<on_timeout> callback.
		146
		147	Zero (the default) disables this timeout.
		148
		149	=item on_timeout => $cb->($handle)
		150
		151	Called whenever the inactivity timeout passes. If you return from this
		152	callback, then the timeout will be reset as if some activity had happened,
		153	so this condition is not fatal in any way.
120		154
121	=item rbuf_max => <bytes>	155	=item rbuf_max => <bytes>
122		156
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	157	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	158	when the read buffer ever (strictly) exceeds this size. This is useful to
…		…
128	be configured to accept only so-and-so much data that it cannot act on	162	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	163	(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	164	amount of data without a callback ever being called as long as the line
131	isn't finished).	165	isn't finished).
132		166
		167	=item autocork => <boolean>
		168
		169	When disabled (the default), then C<push_write> will try to immediately
		170	write the data to the handle if possible. This avoids having to register
		171	a write watcher and wait for the next event loop iteration, but can be
		172	inefficient if you write multiple small chunks (this disadvantage is
		173	usually avoided by your kernel's nagle algorithm, see C<low_delay>).
		174
		175	When enabled, then writes will always be queued till the next event loop
		176	iteration. This is efficient when you do many small writes per iteration,
		177	but less efficient when you do a single write only.
		178
		179	=item no_delay => <boolean>
		180
		181	When doing small writes on sockets, your operating system kernel might
		182	wait a bit for more data before actually sending it out. This is called
		183	the Nagle algorithm, and usually it is beneficial.
		184
		185	In some situations you want as low a delay as possible, which cna be
		186	accomplishd by setting this option to true.
		187
		188	The default is your opertaing system's default behaviour, this option
		189	explicitly enables or disables it, if possible.
		190
133	=item read_size => <bytes>	191	=item read_size => <bytes>
134		192
135	The default read block size (the amount of bytes this module will try to read	193	The default read block size (the amount of bytes this module will try to read
136	on each [loop iteration). Default: C<4096>.	194	during each (loop iteration). Default: C<8192>.
137		195
138	=item low_water_mark => <bytes>	196	=item low_water_mark => <bytes>
139		197
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	198	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	199	buffer: If the write reaches this size or gets even samller it is
142	considered empty.	200	considered empty.
143		201
		202	=item linger => <seconds>
		203
		204	If non-zero (default: C<3600>), then the destructor of the
		205	AnyEvent::Handle object will check wether there is still outstanding write
		206	data and will install a watcher that will write out this data. No errors
		207	will be reported (this mostly matches how the operating system treats
		208	outstanding data at socket close time).
		209
		210	This will not work for partial TLS data that could not yet been
		211	encoded. This data will be lost.
		212
		213	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
		214
		215	When this parameter is given, it enables TLS (SSL) mode, that means it
		216	will start making tls handshake and will transparently encrypt/decrypt
		217	data.
		218
		219	TLS mode requires Net::SSLeay to be installed (it will be loaded
		220	automatically when you try to create a TLS handle).
		221
		222	For the TLS server side, use C<accept>, and for the TLS client side of a
		223	connection, use C<connect> mode.
		224
		225	You can also provide your own TLS connection object, but you have
		226	to make sure that you call either C<Net::SSLeay::set_connect_state>
		227	or C<Net::SSLeay::set_accept_state> on it before you pass it to
		228	AnyEvent::Handle.
		229
		230	See the C<starttls> method if you need to start TLS negotiation later.
		231
		232	=item tls_ctx => $ssl_ctx
		233
		234	Use the given Net::SSLeay::CTX object to create the new TLS connection
		235	(unless a connection object was specified directly). If this parameter is
		236	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
		237
		238	=item json => JSON or JSON::XS object
		239
		240	This is the json coder object used by the C<json> read and write types.
		241
		242	If you don't supply it, then AnyEvent::Handle will create and use a
		243	suitable one, which will write and expect UTF-8 encoded JSON texts.
		244
		245	Note that you are responsible to depend on the JSON module if you want to
		246	use this functionality, as AnyEvent does not have a dependency itself.
		247
		248	=item filter_r => $cb
		249
		250	=item filter_w => $cb
		251
		252	These exist, but are undocumented at this time.
		253
144	=back	254	=back
145		255
146	=cut	256	=cut
147		257
148	sub new {	258	sub new {
…		…
152		262
153	$self->{fh} or Carp::croak "mandatory argument fh is missing";	263	$self->{fh} or Carp::croak "mandatory argument fh is missing";
154		264
155	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	265	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
156		266
157	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	267	if ($self->{tls}) {
158	$self->on_error (delete $self->{on_error}) if $self->{on_error};	268	require Net::SSLeay;
		269	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
		270	}
		271
		272	$self->{_activity} = AnyEvent->now;
		273	$self->_timeout;
		274
159	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	275	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
160	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	276	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
161		277
162	$self->start_read;	278	$self->start_read
		279	if $self->{on_read};
163		280
164	$self	281	$self
165	}	282	}
166		283
167	sub _shutdown {	284	sub _shutdown {
168	my ($self) = @_;	285	my ($self) = @_;
169		286
		287	delete $self->{_tw};
170	delete $self->{rw};	288	delete $self->{_rw};
171	delete $self->{ww};	289	delete $self->{_ww};
172	delete $self->{fh};	290	delete $self->{fh};
173	}
174		291
		292	$self->stoptls;
		293	}
		294
175	sub error {	295	sub _error {
176	my ($self) = @_;	296	my ($self, $errno, $fatal) = @_;
177		297
178	{
179	local $!;
180	$self->_shutdown;	298	$self->_shutdown
181	}	299	if $fatal;
		300
		301	$! = $errno;
182		302
183	if ($self->{on_error}) {	303	if ($self->{on_error}) {
184	$self->{on_error}($self);	304	$self->{on_error}($self, $fatal);
185	} else {	305	} else {
186	die "AnyEvent::Handle uncaught fatal error: $!";	306	Carp::croak "AnyEvent::Handle uncaught error: $!";
187	}	307	}
188	}	308	}
189		309
190	=item $fh = $handle->fh	310	=item $fh = $handle->fh
191		311
192	This method returns the filehandle of the L<AnyEvent::Handle> object.	312	This method returns the file handle of the L<AnyEvent::Handle> object.
193		313
194	=cut	314	=cut
195		315
196	sub fh { $_[0]->{fh} }	316	sub fh { $_[0]{fh} }
197		317
198	=item $handle->on_error ($cb)	318	=item $handle->on_error ($cb)
199		319
200	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	320	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
201		321
…		…
213		333
214	sub on_eof {	334	sub on_eof {
215	$_[0]{on_eof} = $_[1];	335	$_[0]{on_eof} = $_[1];
216	}	336	}
217		337
		338	=item $handle->on_timeout ($cb)
		339
		340	Replace the current C<on_timeout> callback, or disables the callback
		341	(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
		342	argument.
		343
		344	=cut
		345
		346	sub on_timeout {
		347	$_[0]{on_timeout} = $_[1];
		348	}
		349
		350	=item $handle->autocork ($boolean)
		351
		352	Enables or disables the current autocork behaviour (see C<autocork>
		353	constructor argument).
		354
		355	=cut
		356
		357	=item $handle->no_delay ($boolean)
		358
		359	Enables or disables the C<no_delay> setting (see constructor argument of
		360	the same name for details).
		361
		362	=cut
		363
		364	sub no_delay {
		365	$_[0]{no_delay} = $_[1];
		366
		367	eval {
		368	local $SIG{__DIE__};
		369	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		370	};
		371	}
		372
		373	#############################################################################
		374
		375	=item $handle->timeout ($seconds)
		376
		377	Configures (or disables) the inactivity timeout.
		378
		379	=cut
		380
		381	sub timeout {
		382	my ($self, $timeout) = @_;
		383
		384	$self->{timeout} = $timeout;
		385	$self->_timeout;
		386	}
		387
		388	# reset the timeout watcher, as neccessary
		389	# also check for time-outs
		390	sub _timeout {
		391	my ($self) = @_;
		392
		393	if ($self->{timeout}) {
		394	my $NOW = AnyEvent->now;
		395
		396	# when would the timeout trigger?
		397	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		398
		399	# now or in the past already?
		400	if ($after <= 0) {
		401	$self->{_activity} = $NOW;
		402
		403	if ($self->{on_timeout}) {
		404	$self->{on_timeout}($self);
		405	} else {
		406	$self->_error (&Errno::ETIMEDOUT);
		407	}
		408
		409	# callback could have changed timeout value, optimise
		410	return unless $self->{timeout};
		411
		412	# calculate new after
		413	$after = $self->{timeout};
		414	}
		415
		416	Scalar::Util::weaken $self;
		417	return unless $self; # ->error could have destroyed $self
		418
		419	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		420	delete $self->{_tw};
		421	$self->_timeout;
		422	});
		423	} else {
		424	delete $self->{_tw};
		425	}
		426	}
		427
218	#############################################################################	428	#############################################################################
219		429
220	=back	430	=back
221		431
222	=head2 WRITE QUEUE	432	=head2 WRITE QUEUE
…		…
225	for reading.	435	for reading.
226		436
227	The write queue is very simple: you can add data to its end, and	437	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.	438	AnyEvent::Handle will automatically try to get rid of it for you.
229		439
230	When data could be writtena nd the write buffer is shorter then the low	440	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.	441	water mark, the C<on_drain> callback will be invoked.
232		442
233	=over 4	443	=over 4
234		444
235	=item $handle->on_drain ($cb)	445	=item $handle->on_drain ($cb)
…		…
254	want (only limited by the available memory), as C<AnyEvent::Handle>	464	want (only limited by the available memory), as C<AnyEvent::Handle>
255	buffers it independently of the kernel.	465	buffers it independently of the kernel.
256		466
257	=cut	467	=cut
258		468
259	sub push_write {	469	sub _drain_wbuf {
260	my ($self, $data) = @_;	470	my ($self) = @_;
261		471
262	$self->{wbuf} .= $data;	472	if (!$self->{_ww} && length $self->{wbuf}) {
263		473
264	unless ($self->{ww}) {
265	Scalar::Util::weaken $self;	474	Scalar::Util::weaken $self;
		475
266	my $cb = sub {	476	my $cb = sub {
267	my $len = syswrite $self->{fh}, $self->{wbuf};	477	my $len = syswrite $self->{fh}, $self->{wbuf};
268		478
269	if ($len > 0) {	479	if ($len >= 0) {
270	substr $self->{wbuf}, 0, $len, "";	480	substr $self->{wbuf}, 0, $len, "";
271		481
		482	$self->{_activity} = AnyEvent->now;
272		483
273	$self->{on_drain}($self)	484	$self->{on_drain}($self)
274	if $self->{low_water_mark} >= length $self->{wbuf}	485	if $self->{low_water_mark} >= length $self->{wbuf}
275	&& $self->{on_drain};	486	&& $self->{on_drain};
276		487
277	delete $self->{ww} unless length $self->{wbuf};	488	delete $self->{_ww} unless length $self->{wbuf};
278	} elsif ($! != EAGAIN && $! != EINTR) {	489	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
279	$self->error;	490	$self->_error ($!, 1);
280	}	491	}
281	};	492	};
282		493
		494	# try to write data immediately
		495	$cb->() unless $self->{autocork};
		496
		497	# if still data left in wbuf, we need to poll
283	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	498	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
284		499	if length $self->{wbuf};
285	$cb->($self);
286	};	500	};
287	}	501	}
		502
		503	our %WH;
		504
		505	sub register_write_type($$) {
		506	$WH{$_[0]} = $_[1];
		507	}
		508
		509	sub push_write {
		510	my $self = shift;
		511
		512	if (@_ > 1) {
		513	my $type = shift;
		514
		515	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		516	->($self, @_);
		517	}
		518
		519	if ($self->{filter_w}) {
		520	$self->{filter_w}($self, \$_[0]);
		521	} else {
		522	$self->{wbuf} .= $_[0];
		523	$self->_drain_wbuf;
		524	}
		525	}
		526
		527	=item $handle->push_write (type => @args)
		528
		529	Instead of formatting your data yourself, you can also let this module do
		530	the job by specifying a type and type-specific arguments.
		531
		532	Predefined types are (if you have ideas for additional types, feel free to
		533	drop by and tell us):
		534
		535	=over 4
		536
		537	=item netstring => $string
		538
		539	Formats the given value as netstring
		540	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		541
		542	=cut
		543
		544	register_write_type netstring => sub {
		545	my ($self, $string) = @_;
		546
		547	sprintf "%d:%s,", (length $string), $string
		548	};
		549
		550	=item packstring => $format, $data
		551
		552	An octet string prefixed with an encoded length. The encoding C<$format>
		553	uses the same format as a Perl C<pack> format, but must specify a single
		554	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		555	optional C<!>, C<< < >> or C<< > >> modifier).
		556
		557	=cut
		558
		559	register_write_type packstring => sub {
		560	my ($self, $format, $string) = @_;
		561
		562	pack "$format/a*", $string
		563	};
		564
		565	=item json => $array_or_hashref
		566
		567	Encodes the given hash or array reference into a JSON object. Unless you
		568	provide your own JSON object, this means it will be encoded to JSON text
		569	in UTF-8.
		570
		571	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		572	one end of a handle and read them at the other end without using any
		573	additional framing.
		574
		575	The generated JSON text is guaranteed not to contain any newlines: While
		576	this module doesn't need delimiters after or between JSON texts to be
		577	able to read them, many other languages depend on that.
		578
		579	A simple RPC protocol that interoperates easily with others is to send
		580	JSON arrays (or objects, although arrays are usually the better choice as
		581	they mimic how function argument passing works) and a newline after each
		582	JSON text:
		583
		584	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		585	$handle->push_write ("\012");
		586
		587	An AnyEvent::Handle receiver would simply use the C<json> read type and
		588	rely on the fact that the newline will be skipped as leading whitespace:
		589
		590	$handle->push_read (json => sub { my $array = $_[1]; ... });
		591
		592	Other languages could read single lines terminated by a newline and pass
		593	this line into their JSON decoder of choice.
		594
		595	=cut
		596
		597	register_write_type json => sub {
		598	my ($self, $ref) = @_;
		599
		600	require JSON;
		601
		602	$self->{json} ? $self->{json}->encode ($ref)
		603	: JSON::encode_json ($ref)
		604	};
		605
		606	=item storable => $reference
		607
		608	Freezes the given reference using L<Storable> and writes it to the
		609	handle. Uses the C<nfreeze> format.
		610
		611	=cut
		612
		613	register_write_type storable => sub {
		614	my ($self, $ref) = @_;
		615
		616	require Storable;
		617
		618	pack "w/a*", Storable::nfreeze ($ref)
		619	};
		620
		621	=back
		622
		623	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		624
		625	This function (not method) lets you add your own types to C<push_write>.
		626	Whenever the given C<type> is used, C<push_write> will invoke the code
		627	reference with the handle object and the remaining arguments.
		628
		629	The code reference is supposed to return a single octet string that will
		630	be appended to the write buffer.
		631
		632	Note that this is a function, and all types registered this way will be
		633	global, so try to use unique names.
		634
		635	=cut
288		636
289	#############################################################################	637	#############################################################################
290		638
291	=back	639	=back
292		640
…		…
299	ways, the "simple" way, using only C<on_read> and the "complex" way, using	647	ways, the "simple" way, using only C<on_read> and the "complex" way, using
300	a queue.	648	a queue.
301		649
302	In the simple case, you just install an C<on_read> callback and whenever	650	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	651	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	652	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
305	or not.	653	leave the data there if you want to accumulate more (e.g. when only a
		654	partial message has been received so far).
306		655
307	In the more complex case, you want to queue multiple callbacks. In this	656	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	657	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>,	658	data arrives (also the first time it is queued) and removes it when it has
310	below).	659	done its job (see C<push_read>, below).
311		660
312	This way you can, for example, push three line-reads, followed by reading	661	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.	662	a chunk of data, and AnyEvent::Handle will execute them in order.
314		663
315	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	664	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
316	the specified number of bytes which give an XML datagram.	665	the specified number of bytes which give an XML datagram.
317		666
318	# in the default state, expect some header bytes	667	# in the default state, expect some header bytes
319	$handle->on_read (sub {	668	$handle->on_read (sub {
320	# some data is here, now queue the length-header-read (4 octets)	669	# some data is here, now queue the length-header-read (4 octets)
321	shift->unshift_read_chunk (4, sub {	670	shift->unshift_read (chunk => 4, sub {
322	# header arrived, decode	671	# header arrived, decode
323	my $len = unpack "N", $_[1];	672	my $len = unpack "N", $_[1];
324		673
325	# now read the payload	674	# now read the payload
326	shift->unshift_read_chunk ($len, sub {	675	shift->unshift_read (chunk => $len, sub {
327	my $xml = $_[1];	676	my $xml = $_[1];
328	# handle xml	677	# handle xml
329	});	678	});
330	});	679	});
331	});	680	});
332		681
333	Example 2: Implement a client for a protocol that replies either with	682	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	683	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	684	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	685	just pipeline sending both requests and manipulate the queue as necessary
337	the callbacks:	686	in the callbacks.
338		687
339	# request one	688	When the first callback is called and sees an "OK" response, it will
		689	C<unshift> another line-read. This line-read will be queued I<before> the
		690	64-byte chunk callback.
		691
		692	# request one, returns either "OK + extra line" or "ERROR"
340	$handle->push_write ("request 1\015\012");	693	$handle->push_write ("request 1\015\012");
341		694
342	# we expect "ERROR" or "OK" as response, so push a line read	695	# we expect "ERROR" or "OK" as response, so push a line read
343	$handle->push_read_line (sub {	696	$handle->push_read (line => sub {
344	# if we got an "OK", we have to _prepend_ another line,	697	# 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	698	# 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	699	# which are already in the queue when this callback is called
347	# we don't do this in case we got an error	700	# we don't do this in case we got an error
348	if ($_[1] eq "OK") {	701	if ($_[1] eq "OK") {
349	$_[0]->unshift_read_line (sub {	702	$_[0]->unshift_read (line => sub {
350	my $response = $_[1];	703	my $response = $_[1];
351	...	704	...
352	});	705	});
353	}	706	}
354	});	707	});
355		708
356	# request two	709	# request two, simply returns 64 octets
357	$handle->push_write ("request 2\015\012");	710	$handle->push_write ("request 2\015\012");
358		711
359	# simply read 64 bytes, always	712	# simply read 64 bytes, always
360	$handle->push_read_chunk (64, sub {	713	$handle->push_read (chunk => 64, sub {
361	my $response = $_[1];	714	my $response = $_[1];
362	...	715	...
363	});	716	});
364		717
365	=over 4	718	=over 4
…		…
367	=cut	720	=cut
368		721
369	sub _drain_rbuf {	722	sub _drain_rbuf {
370	my ($self) = @_;	723	my ($self) = @_;
371		724
372	return if $self->{in_drain};
373	local $self->{in_drain} = 1;	725	local $self->{_in_drain} = 1;
374		726
375	while (my $len = length $self->{rbuf}) {	727	if (
		728	defined $self->{rbuf_max}
		729	&& $self->{rbuf_max} < length $self->{rbuf}
		730	) {
		731	return $self->_error (&Errno::ENOSPC, 1);
		732	}
		733
		734	while () {
376	no strict 'refs';	735	no strict 'refs';
		736
		737	my $len = length $self->{rbuf};
		738
377	if (my $cb = shift @{ $self->{queue} }) {	739	if (my $cb = shift @{ $self->{_queue} }) {
378	if (!$cb->($self)) {	740	unless ($cb->($self)) {
379	if ($self->{eof}) {	741	if ($self->{_eof}) {
380	# no progress can be made (not enough data and no data forthcoming)	742	# no progress can be made (not enough data and no data forthcoming)
381	$! = &Errno::EPIPE; return $self->error;	743	$self->_error (&Errno::EPIPE, 1), last;
382	}	744	}
383		745
384	unshift @{ $self->{queue} }, $cb;	746	unshift @{ $self->{_queue} }, $cb;
385	return;	747	last;
386	}	748	}
387	} elsif ($self->{on_read}) {	749	} elsif ($self->{on_read}) {
		750	last unless $len;
		751
388	$self->{on_read}($self);	752	$self->{on_read}($self);
389		753
390	if (	754	if (
391	$self->{eof} # if no further data will arrive
392	&& $len == length $self->{rbuf} # and no data has been consumed	755	$len == length $self->{rbuf} # if no data has been consumed
393	&& !@{ $self->{queue} } # and the queue is still empty	756	&& !@{ $self->{_queue} } # and the queue is still empty
394	&& $self->{on_read} # and we still want to read data	757	&& $self->{on_read} # but we still have on_read
395	) {	758	) {
		759	# no further data will arrive
396	# then no progress can be made	760	# so no progress can be made
397	$! = &Errno::EPIPE; return $self->error;	761	$self->_error (&Errno::EPIPE, 1), last
		762	if $self->{_eof};
		763
		764	last; # more data might arrive
398	}	765	}
399	} else {	766	} else {
400	# read side becomes idle	767	# read side becomes idle
401	delete $self->{rw};	768	delete $self->{_rw};
402	return;	769	last;
403	}	770	}
404	}	771	}
405		772
406	if ($self->{eof}) {
407	$self->_shutdown;
408	$self->{on_eof}($self)	773	$self->{on_eof}($self)
409	if $self->{on_eof};	774	if $self->{_eof} && $self->{on_eof};
		775
		776	# may need to restart read watcher
		777	unless ($self->{_rw}) {
		778	$self->start_read
		779	if $self->{on_read} || @{ $self->{_queue} };
410	}	780	}
411	}	781	}
412		782
413	=item $handle->on_read ($cb)	783	=item $handle->on_read ($cb)
414		784
…		…
420		790
421	sub on_read {	791	sub on_read {
422	my ($self, $cb) = @_;	792	my ($self, $cb) = @_;
423		793
424	$self->{on_read} = $cb;	794	$self->{on_read} = $cb;
		795	$self->_drain_rbuf if $cb && !$self->{_in_drain};
425	}	796	}
426		797
427	=item $handle->rbuf	798	=item $handle->rbuf
428		799
429	Returns the read buffer (as a modifiable lvalue).	800	Returns the read buffer (as a modifiable lvalue).
…		…
448	Append the given callback to the end of the queue (C<push_read>) or	819	Append the given callback to the end of the queue (C<push_read>) or
449	prepend it (C<unshift_read>).	820	prepend it (C<unshift_read>).
450		821
451	The callback is called each time some additional read data arrives.	822	The callback is called each time some additional read data arrives.
452		823
453	It must check wether enough data is in the read buffer already.	824	It must check whether enough data is in the read buffer already.
454		825
455	If not enough data is available, it must return the empty list or a false	826	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	827	value, in which case it will be called repeatedly until enough data is
457	available (or an error condition is detected).	828	available (or an error condition is detected).
458		829
…		…
460	interested in (which can be none at all) and return a true value. After returning	831	interested in (which can be none at all) and return a true value. After returning
461	true, it will be removed from the queue.	832	true, it will be removed from the queue.
462		833
463	=cut	834	=cut
464		835
		836	our %RH;
		837
		838	sub register_read_type($$) {
		839	$RH{$_[0]} = $_[1];
		840	}
		841
465	sub push_read {	842	sub push_read {
466	my ($self, $cb) = @_;	843	my $self = shift;
		844	my $cb = pop;
467		845
		846	if (@_) {
		847	my $type = shift;
		848
		849	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		850	->($self, $cb, @_);
		851	}
		852
468	push @{ $self->{queue} }, $cb;	853	push @{ $self->{_queue} }, $cb;
469	$self->_drain_rbuf;	854	$self->_drain_rbuf unless $self->{_in_drain};
470	}	855	}
471		856
472	sub unshift_read {	857	sub unshift_read {
473	my ($self, $cb) = @_;	858	my $self = shift;
		859	my $cb = pop;
474		860
		861	if (@_) {
		862	my $type = shift;
		863
		864	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		865	->($self, $cb, @_);
		866	}
		867
		868
475	push @{ $self->{queue} }, $cb;	869	unshift @{ $self->{_queue} }, $cb;
476	$self->_drain_rbuf;	870	$self->_drain_rbuf unless $self->{_in_drain};
477	}	871	}
478		872
479	=item $handle->push_read_chunk ($len, $cb->($self, $data))	873	=item $handle->push_read (type => @args, $cb)
480		874
481	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	875	=item $handle->unshift_read (type => @args, $cb)
482		876
483	Append the given callback to the end of the queue (C<push_read_chunk>) or	877	Instead of providing a callback that parses the data itself you can chose
484	prepend it (C<unshift_read_chunk>).	878	between a number of predefined parsing formats, for chunks of data, lines
		879	etc.
485		880
486	The callback will be called only once C<$len> bytes have been read, and	881	Predefined types are (if you have ideas for additional types, feel free to
487	these C<$len> bytes will be passed to the callback.	882	drop by and tell us):
488		883
489	=cut	884	=over 4
490		885
491	sub _read_chunk($$) {	886	=item chunk => $octets, $cb->($handle, $data)
		887
		888	Invoke the callback only once C<$octets> bytes have been read. Pass the
		889	data read to the callback. The callback will never be called with less
		890	data.
		891
		892	Example: read 2 bytes.
		893
		894	$handle->push_read (chunk => 2, sub {
		895	warn "yay ", unpack "H*", $_[1];
		896	});
		897
		898	=cut
		899
		900	register_read_type chunk => sub {
492	my ($self, $len, $cb) = @_;	901	my ($self, $cb, $len) = @_;
493		902
494	sub {	903	sub {
495	$len <= length $_[0]{rbuf} or return;	904	$len <= length $_[0]{rbuf} or return;
496	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	905	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
497	1	906	1
498	}	907	}
499	}	908	};
500		909
		910	# compatibility with older API
501	sub push_read_chunk {	911	sub push_read_chunk {
502	$_[0]->push_read (&_read_chunk);	912	$_[0]->push_read (chunk => $_[1], $_[2]);
503	}	913	}
504
505		914
506	sub unshift_read_chunk {	915	sub unshift_read_chunk {
507	$_[0]->unshift_read (&_read_chunk);	916	$_[0]->unshift_read (chunk => $_[1], $_[2]);
508	}	917	}
509		918
510	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))	919	=item line => [$eol, ]$cb->($handle, $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		920
517	The callback will be called only once a full line (including the end of	921	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	922	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	923	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>).	924	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	935	Partial lines at the end of the stream will never be returned, as they are
532	not marked by the end of line marker.	936	not marked by the end of line marker.
533		937
534	=cut	938	=cut
535		939
		940	register_read_type line => sub {
		941	my ($self, $cb, $eol) = @_;
		942
		943	if (@_ < 3) {
		944	# this is more than twice as fast as the generic code below
		945	sub {
		946	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		947
		948	$cb->($_[0], $1, $2);
		949	1
		950	}
		951	} else {
		952	$eol = quotemeta $eol unless ref $eol;
		953	$eol = qr|^(.*?)($eol)|s;
		954
		955	sub {
		956	$_[0]{rbuf} =~ s/$eol// or return;
		957
		958	$cb->($_[0], $1, $2);
		959	1
		960	}
		961	}
		962	};
		963
		964	# compatibility with older API
536	sub _read_line($$) {	965	sub push_read_line {
537	my $self = shift;	966	my $self = shift;
538	my $cb = pop;	967	$self->push_read (line => @_);
539	my $eol = @_ ? shift : qr|(\015?\012)|;	968	}
540	my $pos;
541		969
542	$eol = quotemeta $eol unless ref $eol;	970	sub unshift_read_line {
543	$eol = qr|^(.*?)($eol)|s;	971	my $self = shift;
		972	$self->unshift_read (line => @_);
		973	}
		974
		975	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		976
		977	Makes a regex match against the regex object C<$accept> and returns
		978	everything up to and including the match.
		979
		980	Example: read a single line terminated by '\n'.
		981
		982	$handle->push_read (regex => qr<\n>, sub { ... });
		983
		984	If C<$reject> is given and not undef, then it determines when the data is
		985	to be rejected: it is matched against the data when the C<$accept> regex
		986	does not match and generates an C<EBADMSG> error when it matches. This is
		987	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		988	receive buffer overflow).
		989
		990	Example: expect a single decimal number followed by whitespace, reject
		991	anything else (not the use of an anchor).
		992
		993	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		994
		995	If C<$skip> is given and not C<undef>, then it will be matched against
		996	the receive buffer when neither C<$accept> nor C<$reject> match,
		997	and everything preceding and including the match will be accepted
		998	unconditionally. This is useful to skip large amounts of data that you
		999	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1000	have to start matching from the beginning. This is purely an optimisation
		1001	and is usually worth only when you expect more than a few kilobytes.
		1002
		1003	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1004	expect the header to be very large (it isn't in practise, but...), we use
		1005	a skip regex to skip initial portions. The skip regex is tricky in that
		1006	it only accepts something not ending in either \015 or \012, as these are
		1007	required for the accept regex.
		1008
		1009	$handle->push_read (regex =>
		1010	qr<\015\012\015\012>,
		1011	undef, # no reject
		1012	qr<^.*[^\015\012]>,
		1013	sub { ... });
		1014
		1015	=cut
		1016
		1017	register_read_type regex => sub {
		1018	my ($self, $cb, $accept, $reject, $skip) = @_;
		1019
		1020	my $data;
		1021	my $rbuf = \$self->{rbuf};
544		1022
545	sub {	1023	sub {
546	$_[0]{rbuf} =~ s/$eol// or return;	1024	# accept
		1025	if ($$rbuf =~ $accept) {
		1026	$data .= substr $$rbuf, 0, $+[0], "";
		1027	$cb->($self, $data);
		1028	return 1;
		1029	}
		1030
		1031	# reject
		1032	if ($reject && $$rbuf =~ $reject) {
		1033	$self->_error (&Errno::EBADMSG);
		1034	}
547		1035
548	$cb->($_[0], $1, $2);	1036	# skip
		1037	if ($skip && $$rbuf =~ $skip) {
		1038	$data .= substr $$rbuf, 0, $+[0], "";
		1039	}
		1040
		1041	()
		1042	}
		1043	};
		1044
		1045	=item netstring => $cb->($handle, $string)
		1046
		1047	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1048
		1049	Throws an error with C<$!> set to EBADMSG on format violations.
		1050
		1051	=cut
		1052
		1053	register_read_type netstring => sub {
		1054	my ($self, $cb) = @_;
		1055
		1056	sub {
		1057	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1058	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1059	$self->_error (&Errno::EBADMSG);
		1060	}
		1061	return;
		1062	}
		1063
		1064	my $len = $1;
		1065
		1066	$self->unshift_read (chunk => $len, sub {
		1067	my $string = $_[1];
		1068	$_[0]->unshift_read (chunk => 1, sub {
		1069	if ($_[1] eq ",") {
		1070	$cb->($_[0], $string);
		1071	} else {
		1072	$self->_error (&Errno::EBADMSG);
		1073	}
		1074	});
		1075	});
		1076
549	1	1077	1
550	}	1078	}
551	}	1079	};
552		1080
553	sub push_read_line {	1081	=item packstring => $format, $cb->($handle, $string)
554	$_[0]->push_read (&_read_line);
555	}
556		1082
557	sub unshift_read_line {	1083	An octet string prefixed with an encoded length. The encoding C<$format>
558	$_[0]->unshift_read (&_read_line);	1084	uses the same format as a Perl C<pack> format, but must specify a single
559	}	1085	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1086	optional C<!>, C<< < >> or C<< > >> modifier).
		1087
		1088	DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>.
		1089
		1090	Example: read a block of data prefixed by its length in BER-encoded
		1091	format (very efficient).
		1092
		1093	$handle->push_read (packstring => "w", sub {
		1094	my ($handle, $data) = @_;
		1095	});
		1096
		1097	=cut
		1098
		1099	register_read_type packstring => sub {
		1100	my ($self, $cb, $format) = @_;
		1101
		1102	sub {
		1103	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1104	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1105	or return;
		1106
		1107	$format = length pack $format, $len;
		1108
		1109	# bypass unshift if we already have the remaining chunk
		1110	if ($format + $len <= length $_[0]{rbuf}) {
		1111	my $data = substr $_[0]{rbuf}, $format, $len;
		1112	substr $_[0]{rbuf}, 0, $format + $len, "";
		1113	$cb->($_[0], $data);
		1114	} else {
		1115	# remove prefix
		1116	substr $_[0]{rbuf}, 0, $format, "";
		1117
		1118	# read remaining chunk
		1119	$_[0]->unshift_read (chunk => $len, $cb);
		1120	}
		1121
		1122	1
		1123	}
		1124	};
		1125
		1126	=item json => $cb->($handle, $hash_or_arrayref)
		1127
		1128	Reads a JSON object or array, decodes it and passes it to the callback.
		1129
		1130	If a C<json> object was passed to the constructor, then that will be used
		1131	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1132
		1133	This read type uses the incremental parser available with JSON version
		1134	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1135	dependency on your own: this module will load the JSON module, but
		1136	AnyEvent does not depend on it itself.
		1137
		1138	Since JSON texts are fully self-delimiting, the C<json> read and write
		1139	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1140	the C<json> write type description, above, for an actual example.
		1141
		1142	=cut
		1143
		1144	register_read_type json => sub {
		1145	my ($self, $cb) = @_;
		1146
		1147	require JSON;
		1148
		1149	my $data;
		1150	my $rbuf = \$self->{rbuf};
		1151
		1152	my $json = $self->{json} ||= JSON->new->utf8;
		1153
		1154	sub {
		1155	my $ref = $json->incr_parse ($self->{rbuf});
		1156
		1157	if ($ref) {
		1158	$self->{rbuf} = $json->incr_text;
		1159	$json->incr_text = "";
		1160	$cb->($self, $ref);
		1161
		1162	1
		1163	} else {
		1164	$self->{rbuf} = "";
		1165	()
		1166	}
		1167	}
		1168	};
		1169
		1170	=item storable => $cb->($handle, $ref)
		1171
		1172	Deserialises a L<Storable> frozen representation as written by the
		1173	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1174	data).
		1175
		1176	Raises C<EBADMSG> error if the data could not be decoded.
		1177
		1178	=cut
		1179
		1180	register_read_type storable => sub {
		1181	my ($self, $cb) = @_;
		1182
		1183	require Storable;
		1184
		1185	sub {
		1186	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1187	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1188	or return;
		1189
		1190	my $format = length pack "w", $len;
		1191
		1192	# bypass unshift if we already have the remaining chunk
		1193	if ($format + $len <= length $_[0]{rbuf}) {
		1194	my $data = substr $_[0]{rbuf}, $format, $len;
		1195	substr $_[0]{rbuf}, 0, $format + $len, "";
		1196	$cb->($_[0], Storable::thaw ($data));
		1197	} else {
		1198	# remove prefix
		1199	substr $_[0]{rbuf}, 0, $format, "";
		1200
		1201	# read remaining chunk
		1202	$_[0]->unshift_read (chunk => $len, sub {
		1203	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1204	$cb->($_[0], $ref);
		1205	} else {
		1206	$self->_error (&Errno::EBADMSG);
		1207	}
		1208	});
		1209	}
		1210
		1211	1
		1212	}
		1213	};
		1214
		1215	=back
		1216
		1217	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1218
		1219	This function (not method) lets you add your own types to C<push_read>.
		1220
		1221	Whenever the given C<type> is used, C<push_read> will invoke the code
		1222	reference with the handle object, the callback and the remaining
		1223	arguments.
		1224
		1225	The code reference is supposed to return a callback (usually a closure)
		1226	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1227
		1228	It should invoke the passed callback when it is done reading (remember to
		1229	pass C<$handle> as first argument as all other callbacks do that).
		1230
		1231	Note that this is a function, and all types registered this way will be
		1232	global, so try to use unique names.
		1233
		1234	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1235	search for C<register_read_type>)).
560		1236
561	=item $handle->stop_read	1237	=item $handle->stop_read
562		1238
563	=item $handle->start_read	1239	=item $handle->start_read
564		1240
565	In rare cases you actually do not want to read anything form the	1241	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	1242	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	1243	any queued callbacks will be executed then. To start reading again, call
568	C<start_read>.	1244	C<start_read>.
		1245
		1246	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1247	you change the C<on_read> callback or push/unshift a read callback, and it
		1248	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1249	there are any read requests in the queue.
569		1250
570	=cut	1251	=cut
571		1252
572	sub stop_read {	1253	sub stop_read {
573	my ($self) = @_;	1254	my ($self) = @_;
574		1255
575	delete $self->{rw};	1256	delete $self->{_rw};
576	}	1257	}
577		1258
578	sub start_read {	1259	sub start_read {
579	my ($self) = @_;	1260	my ($self) = @_;
580		1261
581	unless ($self->{rw} || $self->{eof}) {	1262	unless ($self->{_rw} || $self->{_eof}) {
582	Scalar::Util::weaken $self;	1263	Scalar::Util::weaken $self;
583		1264
584	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1265	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
		1266	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};
585	my $len = sysread $self->{fh}, $self->{rbuf}, $self->{read_size} || 8192, length $self->{rbuf};	1267	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
586		1268
587	if ($len > 0) {	1269	if ($len > 0) {
588	if (defined $self->{rbuf_max}) {	1270	$self->{_activity} = AnyEvent->now;
589	if ($self->{rbuf_max} < length $self->{rbuf}) {	1271
590	$! = &Errno::ENOSPC; return $self->error;	1272	$self->{filter_r}
591	}	1273	? $self->{filter_r}($self, $rbuf)
592	}	1274	: $self->{_in_drain} || $self->_drain_rbuf;
593		1275
594	} elsif (defined $len) {	1276	} elsif (defined $len) {
595	$self->{eof} = 1;
596	delete $self->{rw};	1277	delete $self->{_rw};
		1278	$self->{_eof} = 1;
		1279	$self->_drain_rbuf unless $self->{_in_drain};
597		1280
598	} elsif ($! != EAGAIN && $! != EINTR) {	1281	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
599	return $self->error;	1282	return $self->_error ($!, 1);
600	}	1283	}
601
602	$self->_drain_rbuf;
603	});	1284	});
604	}	1285	}
605	}	1286	}
606		1287
		1288	sub _dotls {
		1289	my ($self) = @_;
		1290
		1291	my $buf;
		1292
		1293	if (length $self->{_tls_wbuf}) {
		1294	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
		1295	substr $self->{_tls_wbuf}, 0, $len, "";
		1296	}
		1297	}
		1298
		1299	if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
		1300	$self->{wbuf} .= $buf;
		1301	$self->_drain_wbuf;
		1302	}
		1303
		1304	while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
		1305	if (length $buf) {
		1306	$self->{rbuf} .= $buf;
		1307	$self->_drain_rbuf unless $self->{_in_drain};
		1308	} else {
		1309	# let's treat SSL-eof as we treat normal EOF
		1310	$self->{_eof} = 1;
		1311	$self->_shutdown;
		1312	return;
		1313	}
		1314	}
		1315
		1316	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
		1317
		1318	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
		1319	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
		1320	return $self->_error ($!, 1);
		1321	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
		1322	return $self->_error (&Errno::EIO, 1);
		1323	}
		1324
		1325	# all others are fine for our purposes
		1326	}
		1327	}
		1328
		1329	=item $handle->starttls ($tls[, $tls_ctx])
		1330
		1331	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
		1332	object is created, you can also do that at a later time by calling
		1333	C<starttls>.
		1334
		1335	The first argument is the same as the C<tls> constructor argument (either
		1336	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
		1337
		1338	The second argument is the optional C<Net::SSLeay::CTX> object that is
		1339	used when AnyEvent::Handle has to create its own TLS connection object.
		1340
		1341	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1342	call and can be used or changed to your liking. Note that the handshake
		1343	might have already started when this function returns.
		1344
		1345	=cut
		1346
		1347	sub starttls {
		1348	my ($self, $ssl, $ctx) = @_;
		1349
		1350	$self->stoptls;
		1351
		1352	if ($ssl eq "accept") {
		1353	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1354	Net::SSLeay::set_accept_state ($ssl);
		1355	} elsif ($ssl eq "connect") {
		1356	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
		1357	Net::SSLeay::set_connect_state ($ssl);
		1358	}
		1359
		1360	$self->{tls} = $ssl;
		1361
		1362	# basically, this is deep magic (because SSL_read should have the same issues)
		1363	# but the openssl maintainers basically said: "trust us, it just works".
		1364	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
		1365	# and mismaintained ssleay-module doesn't even offer them).
		1366	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1367	Net::SSLeay::CTX_set_mode ($self->{tls},
		1368	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
		1369	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		1370
		1371	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1372	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
		1373
		1374	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
		1375
		1376	$self->{filter_w} = sub {
		1377	$_[0]{_tls_wbuf} .= ${$_[1]};
		1378	&_dotls;
		1379	};
		1380	$self->{filter_r} = sub {
		1381	Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
		1382	&_dotls;
		1383	};
		1384	}
		1385
		1386	=item $handle->stoptls
		1387
		1388	Destroys the SSL connection, if any. Partial read or write data will be
		1389	lost.
		1390
		1391	=cut
		1392
		1393	sub stoptls {
		1394	my ($self) = @_;
		1395
		1396	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};
		1397
		1398	delete $self->{_rbio};
		1399	delete $self->{_wbio};
		1400	delete $self->{_tls_wbuf};
		1401	delete $self->{filter_r};
		1402	delete $self->{filter_w};
		1403	}
		1404
		1405	sub DESTROY {
		1406	my $self = shift;
		1407
		1408	$self->stoptls;
		1409
		1410	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1411
		1412	if ($linger && length $self->{wbuf}) {
		1413	my $fh = delete $self->{fh};
		1414	my $wbuf = delete $self->{wbuf};
		1415
		1416	my @linger;
		1417
		1418	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1419	my $len = syswrite $fh, $wbuf, length $wbuf;
		1420
		1421	if ($len > 0) {
		1422	substr $wbuf, 0, $len, "";
		1423	} else {
		1424	@linger = (); # end
		1425	}
		1426	});
		1427	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1428	@linger = ();
		1429	});
		1430	}
		1431	}
		1432
		1433	=item AnyEvent::Handle::TLS_CTX
		1434
		1435	This function creates and returns the Net::SSLeay::CTX object used by
		1436	default for TLS mode.
		1437
		1438	The context is created like this:
		1439
		1440	Net::SSLeay::load_error_strings;
		1441	Net::SSLeay::SSLeay_add_ssl_algorithms;
		1442	Net::SSLeay::randomize;
		1443
		1444	my $CTX = Net::SSLeay::CTX_new;
		1445
		1446	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
		1447
		1448	=cut
		1449
		1450	our $TLS_CTX;
		1451
		1452	sub TLS_CTX() {
		1453	$TLS_CTX || do {
		1454	require Net::SSLeay;
		1455
		1456	Net::SSLeay::load_error_strings ();
		1457	Net::SSLeay::SSLeay_add_ssl_algorithms ();
		1458	Net::SSLeay::randomize ();
		1459
		1460	$TLS_CTX = Net::SSLeay::CTX_new ();
		1461
		1462	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
		1463
		1464	$TLS_CTX
		1465	}
		1466	}
		1467
607	=back	1468	=back
608		1469
		1470	=head1 SUBCLASSING AnyEvent::Handle
		1471
		1472	In many cases, you might want to subclass AnyEvent::Handle.
		1473
		1474	To make this easier, a given version of AnyEvent::Handle uses these
		1475	conventions:
		1476
		1477	=over 4
		1478
		1479	=item * all constructor arguments become object members.
		1480
		1481	At least initially, when you pass a C<tls>-argument to the constructor it
		1482	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1483	mutated later on (for example C<tls> will hold the TLS connection object).
		1484
		1485	=item * other object member names are prefixed with an C<_>.
		1486
		1487	All object members not explicitly documented (internal use) are prefixed
		1488	with an underscore character, so the remaining non-C<_>-namespace is free
		1489	for use for subclasses.
		1490
		1491	=item * all members not documented here and not prefixed with an underscore
		1492	are free to use in subclasses.
		1493
		1494	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1495	member variables, but thats just life, at least it is documented.
		1496
		1497	=back
		1498
609	=head1 AUTHOR	1499	=head1 AUTHOR
610		1500
611	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1501	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
612		1502
613	=cut	1503	=cut

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