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Revision 1.27 by root, Sat May 24 15:26:04 2008 UTC vs.
Revision 1.102 by root, Wed Oct 29 14:32:02 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 file handles via AnyEvent	15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16		16
17	This module is experimental.
18
19	=cut	17	=cut
20		18
21	our $VERSION = '0.04';	19	our $VERSION = 4.3;
22		20
23	=head1 SYNOPSIS	21	=head1 SYNOPSIS
24		22
25	use AnyEvent;	23	use AnyEvent;
26	use AnyEvent::Handle;	24	use AnyEvent::Handle;
27		25
28	my $cv = AnyEvent->condvar;	26	my $cv = AnyEvent->condvar;
29		27
30	my $ae_fh = AnyEvent::Handle->new (fh => \*STDIN);	28	my $handle =
31
32	#TODO
33
34	# or use the constructor to pass the callback:
35
36	my $ae_fh2 =
37	AnyEvent::Handle->new (	29	AnyEvent::Handle->new (
38	fh => \*STDIN,	30	fh => \*STDIN,
39	on_eof => sub {	31	on_eof => sub {
40	$cv->broadcast;	32	$cv->broadcast;
41	},	33	},
42	#TODO
43	);	34	);
44		35
45	$cv->wait;	36	# send some request line
		37	$handle->push_write ("getinfo\015\012");
		38
		39	# read the response line
		40	$handle->push_read (line => sub {
		41	my ($handle, $line) = @_;
		42	warn "read line <$line>\n";
		43	$cv->send;
		44	});
		45
		46	$cv->recv;
46		47
47	=head1 DESCRIPTION	48	=head1 DESCRIPTION
48		49
49	This module is a helper module to make it easier to do event-based I/O on	50	This module is a helper module to make it easier to do event-based I/O on
50	filehandles. For utility functions for doing non-blocking connects and accepts	51	filehandles. For utility functions for doing non-blocking connects and accepts
51	on sockets see L<AnyEvent::Util>.	52	on sockets see L<AnyEvent::Util>.
52		53
		54	The L<AnyEvent::Intro> tutorial contains some well-documented
		55	AnyEvent::Handle examples.
		56
53	In the following, when the documentation refers to of "bytes" then this	57	In the following, when the documentation refers to of "bytes" then this
54	means characters. As sysread and syswrite are used for all I/O, their	58	means characters. As sysread and syswrite are used for all I/O, their
55	treatment of characters applies to this module as well.	59	treatment of characters applies to this module as well.
56		60
57	All callbacks will be invoked with the handle object as their first	61	All callbacks will be invoked with the handle object as their first
…		…
69		73
70	=item fh => $filehandle [MANDATORY]	74	=item fh => $filehandle [MANDATORY]
71		75
72	The filehandle this L<AnyEvent::Handle> object will operate on.	76	The filehandle this L<AnyEvent::Handle> object will operate on.
73		77
74	NOTE: The filehandle will be set to non-blocking (using	78	NOTE: The filehandle will be set to non-blocking mode (using
75	AnyEvent::Util::fh_nonblocking).	79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
		80	that mode.
76		81
77	=item on_eof => $cb->($self)	82	=item on_eof => $cb->($handle)
78		83
79	Set the callback to be called on EOF.	84	Set the callback to be called when an end-of-file condition is detected,
		85	i.e. in the case of a socket, when the other side has closed the
		86	connection cleanly.
80		87
		88	For sockets, this just means that the other side has stopped sending data,
		89	you can still try to write data, and, in fact, one can return from the EOF
		90	callback and continue writing data, as only the read part has been shut
		91	down.
		92
81	While not mandatory, it is highly recommended to set an eof callback,	93	While not mandatory, it is I<highly> recommended to set an EOF callback,
82	otherwise you might end up with a closed socket while you are still	94	otherwise you might end up with a closed socket while you are still
83	waiting for data.	95	waiting for data.
84		96
		97	If an EOF condition has been detected but no C<on_eof> callback has been
		98	set, then a fatal error will be raised with C<$!> set to <0>.
		99
85	=item on_error => $cb->($self)	100	=item on_error => $cb->($handle, $fatal)
86		101
87	This is the fatal error callback, that is called when, well, a fatal error	102	This is the error callback, which is called when, well, some error
88	occurs, such as not being able to resolve the hostname, failure to connect	103	occured, such as not being able to resolve the hostname, failure to
89	or a read error.	104	connect or a read error.
90		105
91	The object will not be in a usable state when this callback has been	106	Some errors are fatal (which is indicated by C<$fatal> being true). On
92	called.	107	fatal errors the handle object will be shut down and will not be usable
		108	(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
		109	errors are an EOF condition with active (but unsatisifable) read watchers
		110	(C<EPIPE>) or I/O errors.
		111
		112	Non-fatal errors can be retried by simply returning, but it is recommended
		113	to simply ignore this parameter and instead abondon the handle object
		114	when this callback is invoked. Examples of non-fatal errors are timeouts
		115	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
93		116
94	On callback entrance, the value of C<$!> contains the operating system	117	On callback entrance, the value of C<$!> contains the operating system
95	error (or C<ENOSPC> or C<EPIPE>).	118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
96		119
97	While not mandatory, it is I<highly> recommended to set this callback, as	120	While not mandatory, it is I<highly> recommended to set this callback, as
98	you will not be notified of errors otherwise. The default simply calls	121	you will not be notified of errors otherwise. The default simply calls
99	die.	122	C<croak>.
100		123
101	=item on_read => $cb->($self)	124	=item on_read => $cb->($handle)
102		125
103	This sets the default read callback, which is called when data arrives	126	This sets the default read callback, which is called when data arrives
104	and no read request is in the queue.	127	and no read request is in the queue (unlike read queue callbacks, this
		128	callback will only be called when at least one octet of data is in the
		129	read buffer).
105		130
106	To access (and remove data from) the read buffer, use the C<< ->rbuf >>	131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
107	method or access the C<$self->{rbuf}> member directly.	132	method or access the C<$handle->{rbuf}> member directly.
108		133
109	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
110	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
111	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
112	error will be raised (with C<$!> set to C<EPIPE>).	137	error will be raised (with C<$!> set to C<EPIPE>).
113		138
114	=item on_drain => $cb->()	139	=item on_drain => $cb->($handle)
115		140
116	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
117	(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).
118		143
119	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.
120		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, a non-fatal 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, in which case AnyEvent::Handle will simply
		163	restart the timeout.
		164
		165	Zero (the default) disables this timeout.
		166
		167	=item on_timeout => $cb->($handle)
		168
		169	Called whenever the inactivity timeout passes. If you return from this
		170	callback, then the timeout will be reset as if some activity had happened,
		171	so this condition is not fatal in any way.
		172
121	=item rbuf_max => <bytes>	173	=item rbuf_max => <bytes>
122		174
123	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)	175	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
124	when the read buffer ever (strictly) exceeds this size. This is useful to	176	when the read buffer ever (strictly) exceeds this size. This is useful to
125	avoid denial-of-service attacks.	177	avoid some forms of denial-of-service attacks.
126		178
127	For example, a server accepting connections from untrusted sources should	179	For example, a server accepting connections from untrusted sources should
128	be configured to accept only so-and-so much data that it cannot act on	180	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	181	(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	182	amount of data without a callback ever being called as long as the line
131	isn't finished).	183	isn't finished).
132		184
		185	=item autocork => <boolean>
		186
		187	When disabled (the default), then C<push_write> will try to immediately
		188	write the data to the handle, if possible. This avoids having to register
		189	a write watcher and wait for the next event loop iteration, but can
		190	be inefficient if you write multiple small chunks (on the wire, this
		191	disadvantage is usually avoided by your kernel's nagle algorithm, see
		192	C<no_delay>, but this option can save costly syscalls).
		193
		194	When enabled, then writes will always be queued till the next event loop
		195	iteration. This is efficient when you do many small writes per iteration,
		196	but less efficient when you do a single write only per iteration (or when
		197	the write buffer often is full). It also increases write latency.
		198
		199	=item no_delay => <boolean>
		200
		201	When doing small writes on sockets, your operating system kernel might
		202	wait a bit for more data before actually sending it out. This is called
		203	the Nagle algorithm, and usually it is beneficial.
		204
		205	In some situations you want as low a delay as possible, which can be
		206	accomplishd by setting this option to a true value.
		207
		208	The default is your opertaing system's default behaviour (most likely
		209	enabled), this option explicitly enables or disables it, if possible.
		210
133	=item read_size => <bytes>	211	=item read_size => <bytes>
134		212
135	The default read block size (the amount of bytes this module will try to read	213	The default read block size (the amount of bytes this module will
136	on each [loop iteration). Default: C<4096>.	214	try to read during each loop iteration, which affects memory
		215	requirements). Default: C<8192>.
137		216
138	=item low_water_mark => <bytes>	217	=item low_water_mark => <bytes>
139		218
140	Sets the amount of bytes (default: C<0>) that make up an "empty" write	219	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	220	buffer: If the write reaches this size or gets even samller it is
142	considered empty.	221	considered empty.
143		222
		223	Sometimes it can be beneficial (for performance reasons) to add data to
		224	the write buffer before it is fully drained, but this is a rare case, as
		225	the operating system kernel usually buffers data as well, so the default
		226	is good in almost all cases.
		227
		228	=item linger => <seconds>
		229
		230	If non-zero (default: C<3600>), then the destructor of the
		231	AnyEvent::Handle object will check whether there is still outstanding
		232	write data and will install a watcher that will write this data to the
		233	socket. No errors will be reported (this mostly matches how the operating
		234	system treats outstanding data at socket close time).
		235
		236	This will not work for partial TLS data that could not be encoded
		237	yet. This data will be lost. Calling the C<stoptls> method in time might
		238	help.
		239
144	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	240	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
145		241
146	When this parameter is given, it enables TLS (SSL) mode, that means it	242	When this parameter is given, it enables TLS (SSL) mode, that means
147	will start making tls handshake and will transparently encrypt/decrypt	243	AnyEvent will start a TLS handshake as soon as the conenction has been
148	data.	244	established and will transparently encrypt/decrypt data afterwards.
149		245
150	TLS mode requires Net::SSLeay to be installed (it will be loaded	246	TLS mode requires Net::SSLeay to be installed (it will be loaded
151	automatically when you try to create a TLS handle).	247	automatically when you try to create a TLS handle): this module doesn't
		248	have a dependency on that module, so if your module requires it, you have
		249	to add the dependency yourself.
152		250
153	For the TLS server side, use C<accept>, and for the TLS client side of a	251	Unlike TCP, TLS has a server and client side: for the TLS server side, use
154	connection, use C<connect> mode.	252	C<accept>, and for the TLS client side of a connection, use C<connect>
		253	mode.
155		254
156	You can also provide your own TLS connection object, but you have	255	You can also provide your own TLS connection object, but you have
157	to make sure that you call either C<Net::SSLeay::set_connect_state>	256	to make sure that you call either C<Net::SSLeay::set_connect_state>
158	or C<Net::SSLeay::set_accept_state> on it before you pass it to	257	or C<Net::SSLeay::set_accept_state> on it before you pass it to
159	AnyEvent::Handle.	258	AnyEvent::Handle.
160		259
161	See the C<starttls> method if you need to start TLs negotiation later.	260	See the C<< ->starttls >> method for when need to start TLS negotiation later.
162		261
163	=item tls_ctx => $ssl_ctx	262	=item tls_ctx => $ssl_ctx
164		263
165	Use the given Net::SSLeay::CTX object to create the new TLS connection	264	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
166	(unless a connection object was specified directly). If this parameter is	265	(unless a connection object was specified directly). If this parameter is
167	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	266	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
168		267
		268	=item json => JSON or JSON::XS object
		269
		270	This is the json coder object used by the C<json> read and write types.
		271
		272	If you don't supply it, then AnyEvent::Handle will create and use a
		273	suitable one (on demand), which will write and expect UTF-8 encoded JSON
		274	texts.
		275
		276	Note that you are responsible to depend on the JSON module if you want to
		277	use this functionality, as AnyEvent does not have a dependency itself.
		278
169	=back	279	=back
170		280
171	=cut	281	=cut
172		282
173	sub new {	283	sub new {
…		…
177		287
178	$self->{fh} or Carp::croak "mandatory argument fh is missing";	288	$self->{fh} or Carp::croak "mandatory argument fh is missing";
179		289
180	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	290	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
181		291
182	if ($self->{tls}) {
183	require Net::SSLeay;
184	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx});	292	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
185	}	293	if $self->{tls};
186		294
187	$self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};	295	$self->{_activity} = AnyEvent->now;
188	$self->on_error (delete $self->{on_error}) if $self->{on_error};	296	$self->_timeout;
		297
189	$self->on_drain (delete $self->{on_drain}) if $self->{on_drain};	298	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
190	$self->on_read (delete $self->{on_read} ) if $self->{on_read};	299	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
191		300
192	$self->start_read;	301	$self->start_read
		302	if $self->{on_read};
193		303
194	$self	304	$self
195	}	305	}
196		306
197	sub _shutdown {	307	sub _shutdown {
198	my ($self) = @_;	308	my ($self) = @_;
199		309
		310	delete $self->{_tw};
200	delete $self->{rw};	311	delete $self->{_rw};
201	delete $self->{ww};	312	delete $self->{_ww};
202	delete $self->{fh};	313	delete $self->{fh};
203	}
204		314
		315	&_freetls;
		316
		317	delete $self->{on_read};
		318	delete $self->{_queue};
		319	}
		320
205	sub error {	321	sub _error {
206	my ($self) = @_;	322	my ($self, $errno, $fatal) = @_;
207		323
208	{
209	local $!;
210	$self->_shutdown;	324	$self->_shutdown
211	}	325	if $fatal;
		326
		327	$! = $errno;
212		328
213	if ($self->{on_error}) {	329	if ($self->{on_error}) {
214	$self->{on_error}($self);	330	$self->{on_error}($self, $fatal);
215	} else {	331	} elsif ($self->{fh}) {
216	die "AnyEvent::Handle uncaught fatal error: $!";	332	Carp::croak "AnyEvent::Handle uncaught error: $!";
217	}	333	}
218	}	334	}
219		335
220	=item $fh = $handle->fh	336	=item $fh = $handle->fh
221		337
222	This method returns the file handle of the L<AnyEvent::Handle> object.	338	This method returns the file handle used to create the L<AnyEvent::Handle> object.
223		339
224	=cut	340	=cut
225		341
226	sub fh { $_[0]->{fh} }	342	sub fh { $_[0]{fh} }
227		343
228	=item $handle->on_error ($cb)	344	=item $handle->on_error ($cb)
229		345
230	Replace the current C<on_error> callback (see the C<on_error> constructor argument).	346	Replace the current C<on_error> callback (see the C<on_error> constructor argument).
231		347
…		…
243		359
244	sub on_eof {	360	sub on_eof {
245	$_[0]{on_eof} = $_[1];	361	$_[0]{on_eof} = $_[1];
246	}	362	}
247		363
		364	=item $handle->on_timeout ($cb)
		365
		366	Replace the current C<on_timeout> callback, or disables the callback (but
		367	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
		368	argument and method.
		369
		370	=cut
		371
		372	sub on_timeout {
		373	$_[0]{on_timeout} = $_[1];
		374	}
		375
		376	=item $handle->autocork ($boolean)
		377
		378	Enables or disables the current autocork behaviour (see C<autocork>
		379	constructor argument).
		380
		381	=cut
		382
		383	=item $handle->no_delay ($boolean)
		384
		385	Enables or disables the C<no_delay> setting (see constructor argument of
		386	the same name for details).
		387
		388	=cut
		389
		390	sub no_delay {
		391	$_[0]{no_delay} = $_[1];
		392
		393	eval {
		394	local $SIG{__DIE__};
		395	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
		396	};
		397	}
		398
		399	#############################################################################
		400
		401	=item $handle->timeout ($seconds)
		402
		403	Configures (or disables) the inactivity timeout.
		404
		405	=cut
		406
		407	sub timeout {
		408	my ($self, $timeout) = @_;
		409
		410	$self->{timeout} = $timeout;
		411	$self->_timeout;
		412	}
		413
		414	# reset the timeout watcher, as neccessary
		415	# also check for time-outs
		416	sub _timeout {
		417	my ($self) = @_;
		418
		419	if ($self->{timeout}) {
		420	my $NOW = AnyEvent->now;
		421
		422	# when would the timeout trigger?
		423	my $after = $self->{_activity} + $self->{timeout} - $NOW;
		424
		425	# now or in the past already?
		426	if ($after <= 0) {
		427	$self->{_activity} = $NOW;
		428
		429	if ($self->{on_timeout}) {
		430	$self->{on_timeout}($self);
		431	} else {
		432	$self->_error (&Errno::ETIMEDOUT);
		433	}
		434
		435	# callback could have changed timeout value, optimise
		436	return unless $self->{timeout};
		437
		438	# calculate new after
		439	$after = $self->{timeout};
		440	}
		441
		442	Scalar::Util::weaken $self;
		443	return unless $self; # ->error could have destroyed $self
		444
		445	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
		446	delete $self->{_tw};
		447	$self->_timeout;
		448	});
		449	} else {
		450	delete $self->{_tw};
		451	}
		452	}
		453
248	#############################################################################	454	#############################################################################
249		455
250	=back	456	=back
251		457
252	=head2 WRITE QUEUE	458	=head2 WRITE QUEUE
…		…
273	my ($self, $cb) = @_;	479	my ($self, $cb) = @_;
274		480
275	$self->{on_drain} = $cb;	481	$self->{on_drain} = $cb;
276		482
277	$cb->($self)	483	$cb->($self)
278	if $cb && $self->{low_water_mark} >= length $self->{wbuf};	484	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
279	}	485	}
280		486
281	=item $handle->push_write ($data)	487	=item $handle->push_write ($data)
282		488
283	Queues the given scalar to be written. You can push as much data as you	489	Queues the given scalar to be written. You can push as much data as you
…		…
287	=cut	493	=cut
288		494
289	sub _drain_wbuf {	495	sub _drain_wbuf {
290	my ($self) = @_;	496	my ($self) = @_;
291		497
292	unless ($self->{ww}) {	498	if (!$self->{_ww} && length $self->{wbuf}) {
		499
293	Scalar::Util::weaken $self;	500	Scalar::Util::weaken $self;
		501
294	my $cb = sub {	502	my $cb = sub {
295	my $len = syswrite $self->{fh}, $self->{wbuf};	503	my $len = syswrite $self->{fh}, $self->{wbuf};
296		504
297	if ($len > 0) {	505	if ($len >= 0) {
298	substr $self->{wbuf}, 0, $len, "";	506	substr $self->{wbuf}, 0, $len, "";
299		507
		508	$self->{_activity} = AnyEvent->now;
		509
300	$self->{on_drain}($self)	510	$self->{on_drain}($self)
301	if $self->{low_water_mark} >= length $self->{wbuf}	511	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
302	&& $self->{on_drain};	512	&& $self->{on_drain};
303		513
304	delete $self->{ww} unless length $self->{wbuf};	514	delete $self->{_ww} unless length $self->{wbuf};
305	} elsif ($! != EAGAIN && $! != EINTR) {	515	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
306	$self->error;	516	$self->_error ($!, 1);
307	}	517	}
308	};	518	};
309		519
		520	# try to write data immediately
		521	$cb->() unless $self->{autocork};
		522
		523	# if still data left in wbuf, we need to poll
310	$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb);	524	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
311		525	if length $self->{wbuf};
312	$cb->($self);
313	};	526	};
		527	}
		528
		529	our %WH;
		530
		531	sub register_write_type($$) {
		532	$WH{$_[0]} = $_[1];
314	}	533	}
315		534
316	sub push_write {	535	sub push_write {
317	my $self = shift;	536	my $self = shift;
318		537
		538	if (@_ > 1) {
		539	my $type = shift;
		540
		541	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
		542	->($self, @_);
		543	}
		544
319	if ($self->{filter_w}) {	545	if ($self->{tls}) {
320	$self->{filter_w}->($self, \$_[0]);	546	$self->{_tls_wbuf} .= $_[0];
		547
		548	&_dotls ($self);
321	} else {	549	} else {
322	$self->{wbuf} .= $_[0];	550	$self->{wbuf} .= $_[0];
323	$self->_drain_wbuf;	551	$self->_drain_wbuf;
324	}	552	}
325	}	553	}
326		554
		555	=item $handle->push_write (type => @args)
		556
		557	Instead of formatting your data yourself, you can also let this module do
		558	the job by specifying a type and type-specific arguments.
		559
		560	Predefined types are (if you have ideas for additional types, feel free to
		561	drop by and tell us):
		562
		563	=over 4
		564
		565	=item netstring => $string
		566
		567	Formats the given value as netstring
		568	(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
		569
		570	=cut
		571
		572	register_write_type netstring => sub {
		573	my ($self, $string) = @_;
		574
		575	(length $string) . ":$string,"
		576	};
		577
		578	=item packstring => $format, $data
		579
		580	An octet string prefixed with an encoded length. The encoding C<$format>
		581	uses the same format as a Perl C<pack> format, but must specify a single
		582	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		583	optional C<!>, C<< < >> or C<< > >> modifier).
		584
		585	=cut
		586
		587	register_write_type packstring => sub {
		588	my ($self, $format, $string) = @_;
		589
		590	pack "$format/a*", $string
		591	};
		592
		593	=item json => $array_or_hashref
		594
		595	Encodes the given hash or array reference into a JSON object. Unless you
		596	provide your own JSON object, this means it will be encoded to JSON text
		597	in UTF-8.
		598
		599	JSON objects (and arrays) are self-delimiting, so you can write JSON at
		600	one end of a handle and read them at the other end without using any
		601	additional framing.
		602
		603	The generated JSON text is guaranteed not to contain any newlines: While
		604	this module doesn't need delimiters after or between JSON texts to be
		605	able to read them, many other languages depend on that.
		606
		607	A simple RPC protocol that interoperates easily with others is to send
		608	JSON arrays (or objects, although arrays are usually the better choice as
		609	they mimic how function argument passing works) and a newline after each
		610	JSON text:
		611
		612	$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
		613	$handle->push_write ("\012");
		614
		615	An AnyEvent::Handle receiver would simply use the C<json> read type and
		616	rely on the fact that the newline will be skipped as leading whitespace:
		617
		618	$handle->push_read (json => sub { my $array = $_[1]; ... });
		619
		620	Other languages could read single lines terminated by a newline and pass
		621	this line into their JSON decoder of choice.
		622
		623	=cut
		624
		625	register_write_type json => sub {
		626	my ($self, $ref) = @_;
		627
		628	require JSON;
		629
		630	$self->{json} ? $self->{json}->encode ($ref)
		631	: JSON::encode_json ($ref)
		632	};
		633
		634	=item storable => $reference
		635
		636	Freezes the given reference using L<Storable> and writes it to the
		637	handle. Uses the C<nfreeze> format.
		638
		639	=cut
		640
		641	register_write_type storable => sub {
		642	my ($self, $ref) = @_;
		643
		644	require Storable;
		645
		646	pack "w/a*", Storable::nfreeze ($ref)
		647	};
		648
		649	=back
		650
		651	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
		652
		653	This function (not method) lets you add your own types to C<push_write>.
		654	Whenever the given C<type> is used, C<push_write> will invoke the code
		655	reference with the handle object and the remaining arguments.
		656
		657	The code reference is supposed to return a single octet string that will
		658	be appended to the write buffer.
		659
		660	Note that this is a function, and all types registered this way will be
		661	global, so try to use unique names.
		662
		663	=cut
		664
327	#############################################################################	665	#############################################################################
328		666
329	=back	667	=back
330		668
331	=head2 READ QUEUE	669	=head2 READ QUEUE
…		…
337	ways, the "simple" way, using only C<on_read> and the "complex" way, using	675	ways, the "simple" way, using only C<on_read> and the "complex" way, using
338	a queue.	676	a queue.
339		677
340	In the simple case, you just install an C<on_read> callback and whenever	678	In the simple case, you just install an C<on_read> callback and whenever
341	new data arrives, it will be called. You can then remove some data (if	679	new data arrives, it will be called. You can then remove some data (if
342	enough is there) from the read buffer (C<< $handle->rbuf >>) if you want	680	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
343	or not.	681	leave the data there if you want to accumulate more (e.g. when only a
		682	partial message has been received so far).
344		683
345	In the more complex case, you want to queue multiple callbacks. In this	684	In the more complex case, you want to queue multiple callbacks. In this
346	case, AnyEvent::Handle will call the first queued callback each time new	685	case, AnyEvent::Handle will call the first queued callback each time new
347	data arrives and removes it when it has done its job (see C<push_read>,	686	data arrives (also the first time it is queued) and removes it when it has
348	below).	687	done its job (see C<push_read>, below).
349		688
350	This way you can, for example, push three line-reads, followed by reading	689	This way you can, for example, push three line-reads, followed by reading
351	a chunk of data, and AnyEvent::Handle will execute them in order.	690	a chunk of data, and AnyEvent::Handle will execute them in order.
352		691
353	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by	692	Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
354	the specified number of bytes which give an XML datagram.	693	the specified number of bytes which give an XML datagram.
355		694
356	# in the default state, expect some header bytes	695	# in the default state, expect some header bytes
357	$handle->on_read (sub {	696	$handle->on_read (sub {
358	# some data is here, now queue the length-header-read (4 octets)	697	# some data is here, now queue the length-header-read (4 octets)
359	shift->unshift_read_chunk (4, sub {	698	shift->unshift_read (chunk => 4, sub {
360	# header arrived, decode	699	# header arrived, decode
361	my $len = unpack "N", $_[1];	700	my $len = unpack "N", $_[1];
362		701
363	# now read the payload	702	# now read the payload
364	shift->unshift_read_chunk ($len, sub {	703	shift->unshift_read (chunk => $len, sub {
365	my $xml = $_[1];	704	my $xml = $_[1];
366	# handle xml	705	# handle xml
367	});	706	});
368	});	707	});
369	});	708	});
370		709
371	Example 2: Implement a client for a protocol that replies either with	710	Example 2: Implement a client for a protocol that replies either with "OK"
372	"OK" and another line or "ERROR" for one request, and 64 bytes for the	711	and another line or "ERROR" for the first request that is sent, and 64
373	second request. Due tot he availability of a full queue, we can just	712	bytes for the second request. Due to the availability of a queue, we can
374	pipeline sending both requests and manipulate the queue as necessary in	713	just pipeline sending both requests and manipulate the queue as necessary
375	the callbacks:	714	in the callbacks.
376		715
377	# request one	716	When the first callback is called and sees an "OK" response, it will
		717	C<unshift> another line-read. This line-read will be queued I<before> the
		718	64-byte chunk callback.
		719
		720	# request one, returns either "OK + extra line" or "ERROR"
378	$handle->push_write ("request 1\015\012");	721	$handle->push_write ("request 1\015\012");
379		722
380	# we expect "ERROR" or "OK" as response, so push a line read	723	# we expect "ERROR" or "OK" as response, so push a line read
381	$handle->push_read_line (sub {	724	$handle->push_read (line => sub {
382	# if we got an "OK", we have to _prepend_ another line,	725	# if we got an "OK", we have to _prepend_ another line,
383	# so it will be read before the second request reads its 64 bytes	726	# so it will be read before the second request reads its 64 bytes
384	# which are already in the queue when this callback is called	727	# which are already in the queue when this callback is called
385	# we don't do this in case we got an error	728	# we don't do this in case we got an error
386	if ($_[1] eq "OK") {	729	if ($_[1] eq "OK") {
387	$_[0]->unshift_read_line (sub {	730	$_[0]->unshift_read (line => sub {
388	my $response = $_[1];	731	my $response = $_[1];
389	...	732	...
390	});	733	});
391	}	734	}
392	});	735	});
393		736
394	# request two	737	# request two, simply returns 64 octets
395	$handle->push_write ("request 2\015\012");	738	$handle->push_write ("request 2\015\012");
396		739
397	# simply read 64 bytes, always	740	# simply read 64 bytes, always
398	$handle->push_read_chunk (64, sub {	741	$handle->push_read (chunk => 64, sub {
399	my $response = $_[1];	742	my $response = $_[1];
400	...	743	...
401	});	744	});
402		745
403	=over 4	746	=over 4
404		747
405	=cut	748	=cut
406		749
407	sub _drain_rbuf {	750	sub _drain_rbuf {
408	my ($self) = @_;	751	my ($self) = @_;
		752
		753	local $self->{_in_drain} = 1;
409		754
410	if (	755	if (
411	defined $self->{rbuf_max}	756	defined $self->{rbuf_max}
412	&& $self->{rbuf_max} < length $self->{rbuf}	757	&& $self->{rbuf_max} < length $self->{rbuf}
413	) {	758	) {
414	$! = &Errno::ENOSPC; return $self->error;	759	$self->_error (&Errno::ENOSPC, 1), return;
415	}	760	}
416		761
417	return if $self->{in_drain};	762	while () {
418	local $self->{in_drain} = 1;
419
420	while (my $len = length $self->{rbuf}) {	763	my $len = length $self->{rbuf};
421	no strict 'refs';	764
422	if (my $cb = shift @{ $self->{queue} }) {	765	if (my $cb = shift @{ $self->{_queue} }) {
423	if (!$cb->($self)) {	766	unless ($cb->($self)) {
424	if ($self->{eof}) {	767	if ($self->{_eof}) {
425	# no progress can be made (not enough data and no data forthcoming)	768	# no progress can be made (not enough data and no data forthcoming)
426	$! = &Errno::EPIPE; return $self->error;	769	$self->_error (&Errno::EPIPE, 1), return;
427	}	770	}
428		771
429	unshift @{ $self->{queue} }, $cb;	772	unshift @{ $self->{_queue} }, $cb;
430	return;	773	last;
431	}	774	}
432	} elsif ($self->{on_read}) {	775	} elsif ($self->{on_read}) {
		776	last unless $len;
		777
433	$self->{on_read}($self);	778	$self->{on_read}($self);
434		779
435	if (	780	if (
436	$self->{eof} # if no further data will arrive
437	&& $len == length $self->{rbuf} # and no data has been consumed	781	$len == length $self->{rbuf} # if no data has been consumed
438	&& !@{ $self->{queue} } # and the queue is still empty	782	&& !@{ $self->{_queue} } # and the queue is still empty
439	&& $self->{on_read} # and we still want to read data	783	&& $self->{on_read} # but we still have on_read
440	) {	784	) {
		785	# no further data will arrive
441	# then no progress can be made	786	# so no progress can be made
442	$! = &Errno::EPIPE; return $self->error;	787	$self->_error (&Errno::EPIPE, 1), return
		788	if $self->{_eof};
		789
		790	last; # more data might arrive
443	}	791	}
444	} else {	792	} else {
445	# read side becomes idle	793	# read side becomes idle
446	delete $self->{rw};	794	delete $self->{_rw} unless $self->{tls};
447	return;	795	last;
448	}	796	}
449	}	797	}
450		798
451	if ($self->{eof}) {	799	if ($self->{_eof}) {
452	$self->_shutdown;	800	if ($self->{on_eof}) {
453	$self->{on_eof}($self)	801	$self->{on_eof}($self)
454	if $self->{on_eof};	802	} else {
		803	$self->_error (0, 1);
		804	}
		805	}
		806
		807	# may need to restart read watcher
		808	unless ($self->{_rw}) {
		809	$self->start_read
		810	if $self->{on_read} || @{ $self->{_queue} };
455	}	811	}
456	}	812	}
457		813
458	=item $handle->on_read ($cb)	814	=item $handle->on_read ($cb)
459		815
…		…
465		821
466	sub on_read {	822	sub on_read {
467	my ($self, $cb) = @_;	823	my ($self, $cb) = @_;
468		824
469	$self->{on_read} = $cb;	825	$self->{on_read} = $cb;
		826	$self->_drain_rbuf if $cb && !$self->{_in_drain};
470	}	827	}
471		828
472	=item $handle->rbuf	829	=item $handle->rbuf
473		830
474	Returns the read buffer (as a modifiable lvalue).	831	Returns the read buffer (as a modifiable lvalue).
…		…
505	interested in (which can be none at all) and return a true value. After returning	862	interested in (which can be none at all) and return a true value. After returning
506	true, it will be removed from the queue.	863	true, it will be removed from the queue.
507		864
508	=cut	865	=cut
509		866
		867	our %RH;
		868
		869	sub register_read_type($$) {
		870	$RH{$_[0]} = $_[1];
		871	}
		872
510	sub push_read {	873	sub push_read {
511	my ($self, $cb) = @_;	874	my $self = shift;
		875	my $cb = pop;
512		876
		877	if (@_) {
		878	my $type = shift;
		879
		880	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
		881	->($self, $cb, @_);
		882	}
		883
513	push @{ $self->{queue} }, $cb;	884	push @{ $self->{_queue} }, $cb;
514	$self->_drain_rbuf;	885	$self->_drain_rbuf unless $self->{_in_drain};
515	}	886	}
516		887
517	sub unshift_read {	888	sub unshift_read {
518	my ($self, $cb) = @_;	889	my $self = shift;
		890	my $cb = pop;
519		891
		892	if (@_) {
		893	my $type = shift;
		894
		895	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
		896	->($self, $cb, @_);
		897	}
		898
		899
520	push @{ $self->{queue} }, $cb;	900	unshift @{ $self->{_queue} }, $cb;
521	$self->_drain_rbuf;	901	$self->_drain_rbuf unless $self->{_in_drain};
522	}	902	}
523		903
524	=item $handle->push_read_chunk ($len, $cb->($self, $data))	904	=item $handle->push_read (type => @args, $cb)
525		905
526	=item $handle->unshift_read_chunk ($len, $cb->($self, $data))	906	=item $handle->unshift_read (type => @args, $cb)
527		907
528	Append the given callback to the end of the queue (C<push_read_chunk>) or	908	Instead of providing a callback that parses the data itself you can chose
529	prepend it (C<unshift_read_chunk>).	909	between a number of predefined parsing formats, for chunks of data, lines
		910	etc.
530		911
531	The callback will be called only once C<$len> bytes have been read, and	912	Predefined types are (if you have ideas for additional types, feel free to
532	these C<$len> bytes will be passed to the callback.	913	drop by and tell us):
533		914
534	=cut	915	=over 4
535		916
536	sub _read_chunk($$) {	917	=item chunk => $octets, $cb->($handle, $data)
		918
		919	Invoke the callback only once C<$octets> bytes have been read. Pass the
		920	data read to the callback. The callback will never be called with less
		921	data.
		922
		923	Example: read 2 bytes.
		924
		925	$handle->push_read (chunk => 2, sub {
		926	warn "yay ", unpack "H*", $_[1];
		927	});
		928
		929	=cut
		930
		931	register_read_type chunk => sub {
537	my ($self, $len, $cb) = @_;	932	my ($self, $cb, $len) = @_;
538		933
539	sub {	934	sub {
540	$len <= length $_[0]{rbuf} or return;	935	$len <= length $_[0]{rbuf} or return;
541	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");	936	$cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
542	1	937	1
543	}	938	}
544	}	939	};
545		940
546	sub push_read_chunk {	941	=item line => [$eol, ]$cb->($handle, $line, $eol)
547	$_[0]->push_read (&_read_chunk);
548	}
549
550
551	sub unshift_read_chunk {
552	$_[0]->unshift_read (&_read_chunk);
553	}
554
555	=item $handle->push_read_line ([$eol, ]$cb->($self, $line, $eol))
556
557	=item $handle->unshift_read_line ([$eol, ]$cb->($self, $line, $eol))
558
559	Append the given callback to the end of the queue (C<push_read_line>) or
560	prepend it (C<unshift_read_line>).
561		942
562	The callback will be called only once a full line (including the end of	943	The callback will be called only once a full line (including the end of
563	line marker, C<$eol>) has been read. This line (excluding the end of line	944	line marker, C<$eol>) has been read. This line (excluding the end of line
564	marker) will be passed to the callback as second argument (C<$line>), and	945	marker) will be passed to the callback as second argument (C<$line>), and
565	the end of line marker as the third argument (C<$eol>).	946	the end of line marker as the third argument (C<$eol>).
…		…
576	Partial lines at the end of the stream will never be returned, as they are	957	Partial lines at the end of the stream will never be returned, as they are
577	not marked by the end of line marker.	958	not marked by the end of line marker.
578		959
579	=cut	960	=cut
580		961
581	sub _read_line($$) {	962	register_read_type line => sub {
582	my $self = shift;	963	my ($self, $cb, $eol) = @_;
583	my $cb = pop;
584	my $eol = @_ ? shift : qr|(\015?\012)|;
585	my $pos;
586		964
		965	if (@_ < 3) {
		966	# this is more than twice as fast as the generic code below
		967	sub {
		968	$_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
		969
		970	$cb->($_[0], $1, $2);
		971	1
		972	}
		973	} else {
587	$eol = quotemeta $eol unless ref $eol;	974	$eol = quotemeta $eol unless ref $eol;
588	$eol = qr|^(.*?)($eol)|s;	975	$eol = qr|^(.*?)($eol)|s;
		976
		977	sub {
		978	$_[0]{rbuf} =~ s/$eol// or return;
		979
		980	$cb->($_[0], $1, $2);
		981	1
		982	}
		983	}
		984	};
		985
		986	=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
		987
		988	Makes a regex match against the regex object C<$accept> and returns
		989	everything up to and including the match.
		990
		991	Example: read a single line terminated by '\n'.
		992
		993	$handle->push_read (regex => qr<\n>, sub { ... });
		994
		995	If C<$reject> is given and not undef, then it determines when the data is
		996	to be rejected: it is matched against the data when the C<$accept> regex
		997	does not match and generates an C<EBADMSG> error when it matches. This is
		998	useful to quickly reject wrong data (to avoid waiting for a timeout or a
		999	receive buffer overflow).
		1000
		1001	Example: expect a single decimal number followed by whitespace, reject
		1002	anything else (not the use of an anchor).
		1003
		1004	$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
		1005
		1006	If C<$skip> is given and not C<undef>, then it will be matched against
		1007	the receive buffer when neither C<$accept> nor C<$reject> match,
		1008	and everything preceding and including the match will be accepted
		1009	unconditionally. This is useful to skip large amounts of data that you
		1010	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
		1011	have to start matching from the beginning. This is purely an optimisation
		1012	and is usually worth only when you expect more than a few kilobytes.
		1013
		1014	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
		1015	expect the header to be very large (it isn't in practise, but...), we use
		1016	a skip regex to skip initial portions. The skip regex is tricky in that
		1017	it only accepts something not ending in either \015 or \012, as these are
		1018	required for the accept regex.
		1019
		1020	$handle->push_read (regex =>
		1021	qr<\015\012\015\012>,
		1022	undef, # no reject
		1023	qr<^.*[^\015\012]>,
		1024	sub { ... });
		1025
		1026	=cut
		1027
		1028	register_read_type regex => sub {
		1029	my ($self, $cb, $accept, $reject, $skip) = @_;
		1030
		1031	my $data;
		1032	my $rbuf = \$self->{rbuf};
589		1033
590	sub {	1034	sub {
591	$_[0]{rbuf} =~ s/$eol// or return;	1035	# accept
		1036	if ($$rbuf =~ $accept) {
		1037	$data .= substr $$rbuf, 0, $+[0], "";
		1038	$cb->($self, $data);
		1039	return 1;
		1040	}
		1041
		1042	# reject
		1043	if ($reject && $$rbuf =~ $reject) {
		1044	$self->_error (&Errno::EBADMSG);
		1045	}
592		1046
593	$cb->($_[0], $1, $2);	1047	# skip
		1048	if ($skip && $$rbuf =~ $skip) {
		1049	$data .= substr $$rbuf, 0, $+[0], "";
		1050	}
		1051
		1052	()
		1053	}
		1054	};
		1055
		1056	=item netstring => $cb->($handle, $string)
		1057
		1058	A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
		1059
		1060	Throws an error with C<$!> set to EBADMSG on format violations.
		1061
		1062	=cut
		1063
		1064	register_read_type netstring => sub {
		1065	my ($self, $cb) = @_;
		1066
		1067	sub {
		1068	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
		1069	if ($_[0]{rbuf} =~ /[^0-9]/) {
		1070	$self->_error (&Errno::EBADMSG);
		1071	}
		1072	return;
		1073	}
		1074
		1075	my $len = $1;
		1076
		1077	$self->unshift_read (chunk => $len, sub {
		1078	my $string = $_[1];
		1079	$_[0]->unshift_read (chunk => 1, sub {
		1080	if ($_[1] eq ",") {
		1081	$cb->($_[0], $string);
		1082	} else {
		1083	$self->_error (&Errno::EBADMSG);
		1084	}
		1085	});
		1086	});
		1087
594	1	1088	1
595	}	1089	}
596	}	1090	};
597		1091
598	sub push_read_line {	1092	=item packstring => $format, $cb->($handle, $string)
599	$_[0]->push_read (&_read_line);
600	}
601		1093
602	sub unshift_read_line {	1094	An octet string prefixed with an encoded length. The encoding C<$format>
603	$_[0]->unshift_read (&_read_line);	1095	uses the same format as a Perl C<pack> format, but must specify a single
604	}	1096	integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
		1097	optional C<!>, C<< < >> or C<< > >> modifier).
		1098
		1099	For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
		1100	EPP uses a prefix of C<N> (4 octtes).
		1101
		1102	Example: read a block of data prefixed by its length in BER-encoded
		1103	format (very efficient).
		1104
		1105	$handle->push_read (packstring => "w", sub {
		1106	my ($handle, $data) = @_;
		1107	});
		1108
		1109	=cut
		1110
		1111	register_read_type packstring => sub {
		1112	my ($self, $cb, $format) = @_;
		1113
		1114	sub {
		1115	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1116	defined (my $len = eval { unpack $format, $_[0]{rbuf} })
		1117	or return;
		1118
		1119	$format = length pack $format, $len;
		1120
		1121	# bypass unshift if we already have the remaining chunk
		1122	if ($format + $len <= length $_[0]{rbuf}) {
		1123	my $data = substr $_[0]{rbuf}, $format, $len;
		1124	substr $_[0]{rbuf}, 0, $format + $len, "";
		1125	$cb->($_[0], $data);
		1126	} else {
		1127	# remove prefix
		1128	substr $_[0]{rbuf}, 0, $format, "";
		1129
		1130	# read remaining chunk
		1131	$_[0]->unshift_read (chunk => $len, $cb);
		1132	}
		1133
		1134	1
		1135	}
		1136	};
		1137
		1138	=item json => $cb->($handle, $hash_or_arrayref)
		1139
		1140	Reads a JSON object or array, decodes it and passes it to the callback.
		1141
		1142	If a C<json> object was passed to the constructor, then that will be used
		1143	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
		1144
		1145	This read type uses the incremental parser available with JSON version
		1146	2.09 (and JSON::XS version 2.2) and above. You have to provide a
		1147	dependency on your own: this module will load the JSON module, but
		1148	AnyEvent does not depend on it itself.
		1149
		1150	Since JSON texts are fully self-delimiting, the C<json> read and write
		1151	types are an ideal simple RPC protocol: just exchange JSON datagrams. See
		1152	the C<json> write type description, above, for an actual example.
		1153
		1154	=cut
		1155
		1156	register_read_type json => sub {
		1157	my ($self, $cb) = @_;
		1158
		1159	require JSON;
		1160
		1161	my $data;
		1162	my $rbuf = \$self->{rbuf};
		1163
		1164	my $json = $self->{json} ||= JSON->new->utf8;
		1165
		1166	sub {
		1167	my $ref = $json->incr_parse ($self->{rbuf});
		1168
		1169	if ($ref) {
		1170	$self->{rbuf} = $json->incr_text;
		1171	$json->incr_text = "";
		1172	$cb->($self, $ref);
		1173
		1174	1
		1175	} else {
		1176	$self->{rbuf} = "";
		1177	()
		1178	}
		1179	}
		1180	};
		1181
		1182	=item storable => $cb->($handle, $ref)
		1183
		1184	Deserialises a L<Storable> frozen representation as written by the
		1185	C<storable> write type (BER-encoded length prefix followed by nfreeze'd
		1186	data).
		1187
		1188	Raises C<EBADMSG> error if the data could not be decoded.
		1189
		1190	=cut
		1191
		1192	register_read_type storable => sub {
		1193	my ($self, $cb) = @_;
		1194
		1195	require Storable;
		1196
		1197	sub {
		1198	# when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
		1199	defined (my $len = eval { unpack "w", $_[0]{rbuf} })
		1200	or return;
		1201
		1202	my $format = length pack "w", $len;
		1203
		1204	# bypass unshift if we already have the remaining chunk
		1205	if ($format + $len <= length $_[0]{rbuf}) {
		1206	my $data = substr $_[0]{rbuf}, $format, $len;
		1207	substr $_[0]{rbuf}, 0, $format + $len, "";
		1208	$cb->($_[0], Storable::thaw ($data));
		1209	} else {
		1210	# remove prefix
		1211	substr $_[0]{rbuf}, 0, $format, "";
		1212
		1213	# read remaining chunk
		1214	$_[0]->unshift_read (chunk => $len, sub {
		1215	if (my $ref = eval { Storable::thaw ($_[1]) }) {
		1216	$cb->($_[0], $ref);
		1217	} else {
		1218	$self->_error (&Errno::EBADMSG);
		1219	}
		1220	});
		1221	}
		1222
		1223	1
		1224	}
		1225	};
		1226
		1227	=back
		1228
		1229	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
		1230
		1231	This function (not method) lets you add your own types to C<push_read>.
		1232
		1233	Whenever the given C<type> is used, C<push_read> will invoke the code
		1234	reference with the handle object, the callback and the remaining
		1235	arguments.
		1236
		1237	The code reference is supposed to return a callback (usually a closure)
		1238	that works as a plain read callback (see C<< ->push_read ($cb) >>).
		1239
		1240	It should invoke the passed callback when it is done reading (remember to
		1241	pass C<$handle> as first argument as all other callbacks do that).
		1242
		1243	Note that this is a function, and all types registered this way will be
		1244	global, so try to use unique names.
		1245
		1246	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
		1247	search for C<register_read_type>)).
605		1248
606	=item $handle->stop_read	1249	=item $handle->stop_read
607		1250
608	=item $handle->start_read	1251	=item $handle->start_read
609		1252
610	In rare cases you actually do not want to read anything from the	1253	In rare cases you actually do not want to read anything from the
611	socket. In this case you can call C<stop_read>. Neither C<on_read> no	1254	socket. In this case you can call C<stop_read>. Neither C<on_read> nor
612	any queued callbacks will be executed then. To start reading again, call	1255	any queued callbacks will be executed then. To start reading again, call
613	C<start_read>.	1256	C<start_read>.
614		1257
		1258	Note that AnyEvent::Handle will automatically C<start_read> for you when
		1259	you change the C<on_read> callback or push/unshift a read callback, and it
		1260	will automatically C<stop_read> for you when neither C<on_read> is set nor
		1261	there are any read requests in the queue.
		1262
		1263	These methods will have no effect when in TLS mode (as TLS doesn't support
		1264	half-duplex connections).
		1265
615	=cut	1266	=cut
616		1267
617	sub stop_read {	1268	sub stop_read {
618	my ($self) = @_;	1269	my ($self) = @_;
619		1270
620	delete $self->{rw};	1271	delete $self->{_rw} unless $self->{tls};
621	}	1272	}
622		1273
623	sub start_read {	1274	sub start_read {
624	my ($self) = @_;	1275	my ($self) = @_;
625		1276
626	unless ($self->{rw} || $self->{eof}) {	1277	unless ($self->{_rw} || $self->{_eof}) {
627	Scalar::Util::weaken $self;	1278	Scalar::Util::weaken $self;
628		1279
629	$self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1280	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
630	my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf};	1281	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
631	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1282	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
632		1283
633	if ($len > 0) {	1284	if ($len > 0) {
634	$self->{filter_r}	1285	$self->{_activity} = AnyEvent->now;
635	? $self->{filter_r}->($self, $rbuf)	1286
636	: $self->_drain_rbuf;	1287	if ($self->{tls}) {
		1288	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
		1289
		1290	&_dotls ($self);
		1291	} else {
		1292	$self->_drain_rbuf unless $self->{_in_drain};
		1293	}
637		1294
638	} elsif (defined $len) {	1295	} elsif (defined $len) {
639	delete $self->{rw};	1296	delete $self->{_rw};
640	$self->{eof} = 1;	1297	$self->{_eof} = 1;
641	$self->_drain_rbuf;	1298	$self->_drain_rbuf unless $self->{_in_drain};
642		1299
643	} elsif ($! != EAGAIN && $! != EINTR) {	1300	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
644	return $self->error;	1301	return $self->_error ($!, 1);
645	}	1302	}
646	});	1303	});
647	}	1304	}
648	}	1305	}
649		1306
		1307	# poll the write BIO and send the data if applicable
650	sub _dotls {	1308	sub _dotls {
651	my ($self) = @_;	1309	my ($self) = @_;
652		1310
		1311	my $tmp;
		1312
653	if (length $self->{tls_wbuf}) {	1313	if (length $self->{_tls_wbuf}) {
654	while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) {	1314	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
655	substr $self->{tls_wbuf}, 0, $len, "";	1315	substr $self->{_tls_wbuf}, 0, $tmp, "";
656	}	1316	}
657	}	1317	}
658		1318
659	if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) {	1319	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
		1320	unless (length $tmp) {
		1321	# let's treat SSL-eof as we treat normal EOF
		1322	delete $self->{_rw};
		1323	$self->{_eof} = 1;
		1324	&_freetls;
		1325	}
		1326
		1327	$self->{rbuf} .= $tmp;
		1328	$self->_drain_rbuf unless $self->{_in_drain};
		1329	$self->{tls} or return; # tls session might have gone away in callback
		1330	}
		1331
		1332	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
		1333
		1334	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
		1335	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
		1336	return $self->_error ($!, 1);
		1337	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
		1338	return $self->_error (&Errno::EIO, 1);
		1339	}
		1340
		1341	# all other errors are fine for our purposes
		1342	}
		1343
		1344	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
660	$self->{wbuf} .= $buf;	1345	$self->{wbuf} .= $tmp;
661	$self->_drain_wbuf;	1346	$self->_drain_wbuf;
662	}
663
664	while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
665	$self->{rbuf} .= $buf;
666	$self->_drain_rbuf;
667	}
668
669	my $err = Net::SSLeay::get_error ($self->{tls}, -1);
670
671	if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
672	if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
673	$self->error;
674	} elsif ($err == Net::SSLeay::ERROR_SSL ()) {
675	$! = &Errno::EIO;
676	$self->error;
677	}
678
679	# all others are fine for our purposes
680	}	1347	}
681	}	1348	}
682		1349
683	=item $handle->starttls ($tls[, $tls_ctx])	1350	=item $handle->starttls ($tls[, $tls_ctx])
684		1351
…		…
690	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1357	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
691		1358
692	The second argument is the optional C<Net::SSLeay::CTX> object that is	1359	The second argument is the optional C<Net::SSLeay::CTX> object that is
693	used when AnyEvent::Handle has to create its own TLS connection object.	1360	used when AnyEvent::Handle has to create its own TLS connection object.
694		1361
695	=cut	1362	The TLS connection object will end up in C<< $handle->{tls} >> after this
		1363	call and can be used or changed to your liking. Note that the handshake
		1364	might have already started when this function returns.
696		1365
697	# TODO: maybe document...	1366	If it an error to start a TLS handshake more than once per
		1367	AnyEvent::Handle object (this is due to bugs in OpenSSL).
		1368
		1369	=cut
		1370
698	sub starttls {	1371	sub starttls {
699	my ($self, $ssl, $ctx) = @_;	1372	my ($self, $ssl, $ctx) = @_;
700		1373
701	$self->stoptls;	1374	require Net::SSLeay;
702		1375
		1376	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
		1377	if $self->{tls};
		1378
703	if ($ssl eq "accept") {	1379	if ($ssl eq "accept") {
704	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1380	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
705	Net::SSLeay::set_accept_state ($ssl);	1381	Net::SSLeay::set_accept_state ($ssl);
706	} elsif ($ssl eq "connect") {	1382	} elsif ($ssl eq "connect") {
707	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1383	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
…		…
713	# basically, this is deep magic (because SSL_read should have the same issues)	1389	# basically, this is deep magic (because SSL_read should have the same issues)
714	# but the openssl maintainers basically said: "trust us, it just works".	1390	# but the openssl maintainers basically said: "trust us, it just works".
715	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1391	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
716	# and mismaintained ssleay-module doesn't even offer them).	1392	# and mismaintained ssleay-module doesn't even offer them).
717	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html	1393	# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
		1394	#
		1395	# in short: this is a mess.
		1396	#
		1397	# note that we do not try to keep the length constant between writes as we are required to do.
		1398	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
		1399	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
		1400	# have identity issues in that area.
718	Net::SSLeay::CTX_set_mode ($self->{tls},	1401	Net::SSLeay::CTX_set_mode ($self->{tls},
719	(eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	1402	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
720	| (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	1403	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
721		1404
722	$self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1405	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
723	$self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	1406	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
724		1407
725	Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio});	1408	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
726		1409
727	$self->{filter_w} = sub {	1410	&_dotls; # need to trigger the initial handshake
728	$_[0]{tls_wbuf} .= ${$_[1]};	1411	$self->start_read; # make sure we actually do read
729	&_dotls;
730	};
731	$self->{filter_r} = sub {
732	Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
733	&_dotls;
734	};
735	}	1412	}
736		1413
737	=item $handle->stoptls	1414	=item $handle->stoptls
738		1415
739	Destroys the SSL connection, if any. Partial read or write data will be	1416	Shuts down the SSL connection - this makes a proper EOF handshake by
740	lost.	1417	sending a close notify to the other side, but since OpenSSL doesn't
		1418	support non-blocking shut downs, it is not possible to re-use the stream
		1419	afterwards.
741		1420
742	=cut	1421	=cut
743		1422
744	sub stoptls {	1423	sub stoptls {
745	my ($self) = @_;	1424	my ($self) = @_;
746		1425
		1426	if ($self->{tls}) {
		1427	Net::SSLeay::shutdown ($self->{tls});
		1428
		1429	&_dotls;
		1430
		1431	# we don't give a shit. no, we do, but we can't. no...
		1432	# we, we... have to use openssl :/
		1433	&_freetls;
		1434	}
		1435	}
		1436
		1437	sub _freetls {
		1438	my ($self) = @_;
		1439
		1440	return unless $self->{tls};
		1441
747	Net::SSLeay::free (delete $self->{tls}) if $self->{tls};	1442	Net::SSLeay::free (delete $self->{tls});
748	delete $self->{tls_rbio};	1443
749	delete $self->{tls_wbio};	1444	delete @$self{qw(_rbio _wbio _tls_wbuf)};
750	delete $self->{tls_wbuf};
751	delete $self->{filter_r};
752	delete $self->{filter_w};
753	}	1445	}
754		1446
755	sub DESTROY {	1447	sub DESTROY {
756	my $self = shift;	1448	my $self = shift;
757		1449
758	$self->stoptls;	1450	&_freetls;
		1451
		1452	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
		1453
		1454	if ($linger && length $self->{wbuf}) {
		1455	my $fh = delete $self->{fh};
		1456	my $wbuf = delete $self->{wbuf};
		1457
		1458	my @linger;
		1459
		1460	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
		1461	my $len = syswrite $fh, $wbuf, length $wbuf;
		1462
		1463	if ($len > 0) {
		1464	substr $wbuf, 0, $len, "";
		1465	} else {
		1466	@linger = (); # end
		1467	}
		1468	});
		1469	push @linger, AnyEvent->timer (after => $linger, cb => sub {
		1470	@linger = ();
		1471	});
		1472	}
		1473	}
		1474
		1475	=item $handle->destroy
		1476
		1477	Shuts down the handle object as much as possible - this call ensures that
		1478	no further callbacks will be invoked and resources will be freed as much
		1479	as possible. You must not call any methods on the object afterwards.
		1480
		1481	Normally, you can just "forget" any references to an AnyEvent::Handle
		1482	object and it will simply shut down. This works in fatal error and EOF
		1483	callbacks, as well as code outside. It does I<NOT> work in a read or write
		1484	callback, so when you want to destroy the AnyEvent::Handle object from
		1485	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
		1486	that case.
		1487
		1488	The handle might still linger in the background and write out remaining
		1489	data, as specified by the C<linger> option, however.
		1490
		1491	=cut
		1492
		1493	sub destroy {
		1494	my ($self) = @_;
		1495
		1496	$self->DESTROY;
		1497	%$self = ();
759	}	1498	}
760		1499
761	=item AnyEvent::Handle::TLS_CTX	1500	=item AnyEvent::Handle::TLS_CTX
762		1501
763	This function creates and returns the Net::SSLeay::CTX object used by	1502	This function creates and returns the Net::SSLeay::CTX object used by
…		…
793	}	1532	}
794	}	1533	}
795		1534
796	=back	1535	=back
797		1536
		1537
		1538	=head1 NONFREQUENTLY ASKED QUESTIONS
		1539
		1540	=over 4
		1541
		1542	=item I C<undef> the AnyEvent::Handle reference inside my callback and
		1543	still get further invocations!
		1544
		1545	That's because AnyEvent::Handle keeps a reference to itself when handling
		1546	read or write callbacks.
		1547
		1548	It is only safe to "forget" the reference inside EOF or error callbacks,
		1549	from within all other callbacks, you need to explicitly call the C<<
		1550	->destroy >> method.
		1551
		1552	=item I get different callback invocations in TLS mode/Why can't I pause
		1553	reading?
		1554
		1555	Unlike, say, TCP, TLS connections do not consist of two independent
		1556	communication channels, one for each direction. Or put differently. The
		1557	read and write directions are not independent of each other: you cannot
		1558	write data unless you are also prepared to read, and vice versa.
		1559
		1560	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
		1561	callback invocations when you are not expecting any read data - the reason
		1562	is that AnyEvent::Handle always reads in TLS mode.
		1563
		1564	During the connection, you have to make sure that you always have a
		1565	non-empty read-queue, or an C<on_read> watcher. At the end of the
		1566	connection (or when you no longer want to use it) you can call the
		1567	C<destroy> method.
		1568
		1569	=item How do I read data until the other side closes the connection?
		1570
		1571	If you just want to read your data into a perl scalar, the easiest way
		1572	to achieve this is by setting an C<on_read> callback that does nothing,
		1573	clearing the C<on_eof> callback and in the C<on_error> callback, the data
		1574	will be in C<$_[0]{rbuf}>:
		1575
		1576	$handle->on_read (sub { });
		1577	$handle->on_eof (undef);
		1578	$handle->on_error (sub {
		1579	my $data = delete $_[0]{rbuf};
		1580	undef $handle;
		1581	});
		1582
		1583	The reason to use C<on_error> is that TCP connections, due to latencies
		1584	and packets loss, might get closed quite violently with an error, when in
		1585	fact, all data has been received.
		1586
		1587	It is usually better to use acknowledgements when transferring data,
		1588	to make sure the other side hasn't just died and you got the data
		1589	intact. This is also one reason why so many internet protocols have an
		1590	explicit QUIT command.
		1591
		1592	=item I don't want to destroy the handle too early - how do I wait until
		1593	all data has been written?
		1594
		1595	After writing your last bits of data, set the C<on_drain> callback
		1596	and destroy the handle in there - with the default setting of
		1597	C<low_water_mark> this will be called precisely when all data has been
		1598	written to the socket:
		1599
		1600	$handle->push_write (...);
		1601	$handle->on_drain (sub {
		1602	warn "all data submitted to the kernel\n";
		1603	undef $handle;
		1604	});
		1605
		1606	=back
		1607
		1608
		1609	=head1 SUBCLASSING AnyEvent::Handle
		1610
		1611	In many cases, you might want to subclass AnyEvent::Handle.
		1612
		1613	To make this easier, a given version of AnyEvent::Handle uses these
		1614	conventions:
		1615
		1616	=over 4
		1617
		1618	=item * all constructor arguments become object members.
		1619
		1620	At least initially, when you pass a C<tls>-argument to the constructor it
		1621	will end up in C<< $handle->{tls} >>. Those members might be changed or
		1622	mutated later on (for example C<tls> will hold the TLS connection object).
		1623
		1624	=item * other object member names are prefixed with an C<_>.
		1625
		1626	All object members not explicitly documented (internal use) are prefixed
		1627	with an underscore character, so the remaining non-C<_>-namespace is free
		1628	for use for subclasses.
		1629
		1630	=item * all members not documented here and not prefixed with an underscore
		1631	are free to use in subclasses.
		1632
		1633	Of course, new versions of AnyEvent::Handle may introduce more "public"
		1634	member variables, but thats just life, at least it is documented.
		1635
		1636	=back
		1637
798	=head1 AUTHOR	1638	=head1 AUTHOR
799		1639
800	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.	1640	Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
801		1641
802	=cut	1642	=cut

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