ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent/Handle.pm

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.108 by root, Tue Jan 6 20:08:05 2009 UTC vs.
Revision 1.222 by root, Thu Aug 25 03:08:48 2011 UTC

1	package AnyEvent::Handle;
2
3	no warnings;
4	use strict qw(subs vars);
5
6	use AnyEvent ();
7	use AnyEvent::Util qw(WSAEWOULDBLOCK);
8	use Scalar::Util ();
9	use Carp ();
10	use Fcntl ();
11	use Errno qw(EAGAIN EINTR);
12
13	=head1 NAME	1	=head1 NAME
14		2
15	AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent	3	AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
16
17	=cut
18
19	our $VERSION = 4.331;
20		4
21	=head1 SYNOPSIS	5	=head1 SYNOPSIS
22		6
23	use AnyEvent;	7	use AnyEvent;
24	use AnyEvent::Handle;	8	use AnyEvent::Handle;
25		9
26	my $cv = AnyEvent->condvar;	10	my $cv = AnyEvent->condvar;
27		11
28	my $handle =	12	my $hdl; $hdl = new AnyEvent::Handle
29	AnyEvent::Handle->new (
30	fh => \*STDIN,	13	fh => \*STDIN,
31	on_eof => sub {	14	on_error => sub {
		15	my ($hdl, $fatal, $msg) = @_;
		16	AE::log warn => "got error $msg\n";
		17	$hdl->destroy;
32	$cv->send;	18	$cv->send;
33	},
34	);	19	};
35		20
36	# send some request line	21	# send some request line
37	$handle->push_write ("getinfo\015\012");	22	$hdl->push_write ("getinfo\015\012");
38		23
39	# read the response line	24	# read the response line
40	$handle->push_read (line => sub {	25	$hdl->push_read (line => sub {
41	my ($handle, $line) = @_;	26	my ($hdl, $line) = @_;
42	warn "read line <$line>\n";	27	AE::log warn => "got line <$line>\n";
43	$cv->send;	28	$cv->send;
44	});	29	});
45		30
46	$cv->recv;	31	$cv->recv;
47		32
48	=head1 DESCRIPTION	33	=head1 DESCRIPTION
49		34
50	This module is a helper module to make it easier to do event-based I/O on	35	This is a helper module to make it easier to do event-based I/O on
51	filehandles. For utility functions for doing non-blocking connects and accepts	36	stream-based filehandles (sockets, pipes, and other stream things).
52	on sockets see L<AnyEvent::Util>.
53		37
54	The L<AnyEvent::Intro> tutorial contains some well-documented	38	The L<AnyEvent::Intro> tutorial contains some well-documented
55	AnyEvent::Handle examples.	39	AnyEvent::Handle examples.
56		40
57	In the following, when the documentation refers to of "bytes" then this	41	In the following, where the documentation refers to "bytes", it means
58	means characters. As sysread and syswrite are used for all I/O, their	42	characters. As sysread and syswrite are used for all I/O, their
59	treatment of characters applies to this module as well.	43	treatment of characters applies to this module as well.
		44
		45	At the very minimum, you should specify C<fh> or C<connect>, and the
		46	C<on_error> callback.
60		47
61	All callbacks will be invoked with the handle object as their first	48	All callbacks will be invoked with the handle object as their first
62	argument.	49	argument.
63		50
		51	=cut
		52
		53	package AnyEvent::Handle;
		54
		55	use Scalar::Util ();
		56	use List::Util ();
		57	use Carp ();
		58	use Errno qw(EAGAIN EINTR);
		59
		60	use AnyEvent (); BEGIN { AnyEvent::common_sense }
		61	use AnyEvent::Util qw(WSAEWOULDBLOCK);
		62
		63	our $VERSION = $AnyEvent::VERSION;
		64
		65	sub _load_func($) {
		66	my $func = $_[0];
		67
		68	unless (defined &$func) {
		69	my $pkg = $func;
		70	do {
		71	$pkg =~ s/::[^:]+$//
		72	or return;
		73	eval "require $pkg";
		74	} until defined &$func;
		75	}
		76
		77	\&$func
		78	}
		79
		80	sub MAX_READ_SIZE() { 131072 }
		81
64	=head1 METHODS	82	=head1 METHODS
65		83
66	=over 4	84	=over 4
67		85
68	=item B<new (%args)>	86	=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
69		87
70	The constructor supports these arguments (all as key => value pairs).	88	The constructor supports these arguments (all as C<< key => value >> pairs).
71		89
72	=over 4	90	=over 4
73		91
74	=item fh => $filehandle [MANDATORY]	92	=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
75		93
76	The filehandle this L<AnyEvent::Handle> object will operate on.	94	The filehandle this L<AnyEvent::Handle> object will operate on.
77
78	NOTE: The filehandle will be set to non-blocking mode (using	95	NOTE: The filehandle will be set to non-blocking mode (using
79	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in	96	C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80	that mode.	97	that mode.
81		98
		99	=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
		100
		101	Try to connect to the specified host and service (port), using
		102	C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
		103	default C<peername>.
		104
		105	You have to specify either this parameter, or C<fh>, above.
		106
		107	It is possible to push requests on the read and write queues, and modify
		108	properties of the stream, even while AnyEvent::Handle is connecting.
		109
		110	When this parameter is specified, then the C<on_prepare>,
		111	C<on_connect_error> and C<on_connect> callbacks will be called under the
		112	appropriate circumstances:
		113
		114	=over 4
		115
		116	=item on_prepare => $cb->($handle)
		117
		118	This (rarely used) callback is called before a new connection is
		119	attempted, but after the file handle has been created (you can access that
		120	file handle via C<< $handle->{fh} >>). It could be used to prepare the
		121	file handle with parameters required for the actual connect (as opposed to
		122	settings that can be changed when the connection is already established).
		123
		124	The return value of this callback should be the connect timeout value in
		125	seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
		126	default timeout is to be used).
		127
		128	=item on_connect => $cb->($handle, $host, $port, $retry->())
		129
		130	This callback is called when a connection has been successfully established.
		131
		132	The peer's numeric host and port (the socket peername) are passed as
		133	parameters, together with a retry callback.
		134
		135	If, for some reason, the handle is not acceptable, calling C<$retry>
		136	will continue with the next connection target (in case of multi-homed
		137	hosts or SRV records there can be multiple connection endpoints). At the
		138	time it is called the read and write queues, eof status, tls status and
		139	similar properties of the handle will have been reset.
		140
		141	In most cases, you should ignore the C<$retry> parameter.
		142
		143	=item on_connect_error => $cb->($handle, $message)
		144
		145	This callback is called when the connection could not be
		146	established. C<$!> will contain the relevant error code, and C<$message> a
		147	message describing it (usually the same as C<"$!">).
		148
		149	If this callback isn't specified, then C<on_error> will be called with a
		150	fatal error instead.
		151
		152	=back
		153
		154	=item on_error => $cb->($handle, $fatal, $message)
		155
		156	This is the error callback, which is called when, well, some error
		157	occured, such as not being able to resolve the hostname, failure to
		158	connect, or a read error.
		159
		160	Some errors are fatal (which is indicated by C<$fatal> being true). On
		161	fatal errors the handle object will be destroyed (by a call to C<< ->
		162	destroy >>) after invoking the error callback (which means you are free to
		163	examine the handle object). Examples of fatal errors are an EOF condition
		164	with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
		165	cases where the other side can close the connection at will, it is
		166	often easiest to not report C<EPIPE> errors in this callback.
		167
		168	AnyEvent::Handle tries to find an appropriate error code for you to check
		169	against, but in some cases (TLS errors), this does not work well. It is
		170	recommended to always output the C<$message> argument in human-readable
		171	error messages (it's usually the same as C<"$!">).
		172
		173	Non-fatal errors can be retried by returning, but it is recommended
		174	to simply ignore this parameter and instead abondon the handle object
		175	when this callback is invoked. Examples of non-fatal errors are timeouts
		176	C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
		177
		178	On entry to the callback, the value of C<$!> contains the operating
		179	system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
		180	C<EPROTO>).
		181
		182	While not mandatory, it is I<highly> recommended to set this callback, as
		183	you will not be notified of errors otherwise. The default just calls
		184	C<croak>.
		185
		186	=item on_read => $cb->($handle)
		187
		188	This sets the default read callback, which is called when data arrives
		189	and no read request is in the queue (unlike read queue callbacks, this
		190	callback will only be called when at least one octet of data is in the
		191	read buffer).
		192
		193	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
		194	method or access the C<< $handle->{rbuf} >> member directly. Note that you
		195	must not enlarge or modify the read buffer, you can only remove data at
		196	the beginning from it.
		197
		198	You can also call C<< ->push_read (...) >> or any other function that
		199	modifies the read queue. Or do both. Or ...
		200
		201	When an EOF condition is detected, AnyEvent::Handle will first try to
		202	feed all the remaining data to the queued callbacks and C<on_read> before
		203	calling the C<on_eof> callback. If no progress can be made, then a fatal
		204	error will be raised (with C<$!> set to C<EPIPE>).
		205
		206	Note that, unlike requests in the read queue, an C<on_read> callback
		207	doesn't mean you I<require> some data: if there is an EOF and there
		208	are outstanding read requests then an error will be flagged. With an
		209	C<on_read> callback, the C<on_eof> callback will be invoked.
		210
82	=item on_eof => $cb->($handle)	211	=item on_eof => $cb->($handle)
83		212
84	Set the callback to be called when an end-of-file condition is detected,	213	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	214	i.e. in the case of a socket, when the other side has closed the
86	connection cleanly.	215	connection cleanly, and there are no outstanding read requests in the
		216	queue (if there are read requests, then an EOF counts as an unexpected
		217	connection close and will be flagged as an error).
87		218
88	For sockets, this just means that the other side has stopped sending data,	219	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	220	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	221	callback and continue writing data, as only the read part has been shut
91	down.	222	down.
92		223
93	While not mandatory, it is I<highly> recommended to set an EOF callback,
94	otherwise you might end up with a closed socket while you are still
95	waiting for data.
96
97	If an EOF condition has been detected but no C<on_eof> callback has been	224	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<$!> set to <0>.	225	set, then a fatal error will be raised with C<$!> set to <0>.
99		226
100	=item on_error => $cb->($handle, $fatal)
101
102	This is the error callback, which is called when, well, some error
103	occured, such as not being able to resolve the hostname, failure to
104	connect or a read error.
105
106	Some errors are fatal (which is indicated by C<$fatal> being true). On
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>).
116
117	On callback entrance, the value of C<$!> contains the operating system
118	error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
119
120	While not mandatory, it is I<highly> recommended to set this callback, as
121	you will not be notified of errors otherwise. The default simply calls
122	C<croak>.
123
124	=item on_read => $cb->($handle)
125
126	This sets the default read callback, which is called when data arrives
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).
130
131	To access (and remove data from) the read buffer, use the C<< ->rbuf >>
132	method or access the C<$handle->{rbuf}> member directly.
133
134	When an EOF condition is detected then AnyEvent::Handle will first try to
135	feed all the remaining data to the queued callbacks and C<on_read> before
136	calling the C<on_eof> callback. If no progress can be made, then a fatal
137	error will be raised (with C<$!> set to C<EPIPE>).
138
139	=item on_drain => $cb->($handle)	227	=item on_drain => $cb->($handle)
140		228
141	This sets the callback that is called when the write buffer becomes empty	229	This sets the callback that is called when the write buffer becomes empty
142	(or when the callback is set and the buffer is empty already).	230	(or immediately if the buffer is empty already).
143		231
144	To append to the write buffer, use the C<< ->push_write >> method.	232	To append to the write buffer, use the C<< ->push_write >> method.
145		233
146	This callback is useful when you don't want to put all of your write data	234	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	235	into the queue at once, for example, when you want to write the contents
…		…
149	memory and push it into the queue, but instead only read more data from	237	memory and push it into the queue, but instead only read more data from
150	the file when the write queue becomes empty.	238	the file when the write queue becomes empty.
151		239
152	=item timeout => $fractional_seconds	240	=item timeout => $fractional_seconds
153		241
		242	=item rtimeout => $fractional_seconds
		243
		244	=item wtimeout => $fractional_seconds
		245
154	If non-zero, then this enables an "inactivity" timeout: whenever this many	246	If non-zero, then these enables an "inactivity" timeout: whenever this
155	seconds pass without a successful read or write on the underlying file	247	many seconds pass without a successful read or write on the underlying
156	handle, the C<on_timeout> callback will be invoked (and if that one is	248	file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
157	missing, a non-fatal C<ETIMEDOUT> error will be raised).	249	will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
		250	error will be raised).
158		251
		252	There are three variants of the timeouts that work independently of each
		253	other, for both read and write (triggered when nothing was read I<OR>
		254	written), just read (triggered when nothing was read), and just write:
		255	C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
		256	C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
		257	C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
		258
159	Note that timeout processing is also active when you currently do not have	259	Note that timeout processing is active even when you do not have any
160	any outstanding read or write requests: If you plan to keep the connection	260	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	261	idle then you should disable the timeout temporarily or ignore the
162	in the C<on_timeout> callback, in which case AnyEvent::Handle will simply	262	timeout in the corresponding C<on_timeout> callback, in which case
163	restart the timeout.	263	AnyEvent::Handle will simply restart the timeout.
164		264
165	Zero (the default) disables this timeout.	265	Zero (the default) disables the corresponding timeout.
166		266
167	=item on_timeout => $cb->($handle)	267	=item on_timeout => $cb->($handle)
		268
		269	=item on_rtimeout => $cb->($handle)
		270
		271	=item on_wtimeout => $cb->($handle)
168		272
169	Called whenever the inactivity timeout passes. If you return from this	273	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,	274	callback, then the timeout will be reset as if some activity had happened,
171	so this condition is not fatal in any way.	275	so this condition is not fatal in any way.
172		276
…		…
180	be configured to accept only so-and-so much data that it cannot act on	284	be configured to accept only so-and-so much data that it cannot act on
181	(for example, when expecting a line, an attacker could send an unlimited	285	(for example, when expecting a line, an attacker could send an unlimited
182	amount of data without a callback ever being called as long as the line	286	amount of data without a callback ever being called as long as the line
183	isn't finished).	287	isn't finished).
184		288
		289	=item wbuf_max => <bytes>
		290
		291	If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
		292	when the write buffer ever (strictly) exceeds this size. This is useful to
		293	avoid some forms of denial-of-service attacks.
		294
		295	Although the units of this parameter is bytes, this is the I<raw> number
		296	of bytes not yet accepted by the kernel. This can make a difference when
		297	you e.g. use TLS, as TLS typically makes your write data larger (but it
		298	can also make it smaller due to compression).
		299
		300	As an example of when this limit is useful, take a chat server that sends
		301	chat messages to a client. If the client does not read those in a timely
		302	manner then the send buffer in the server would grow unbounded.
		303
185	=item autocork => <boolean>	304	=item autocork => <boolean>
186		305
187	When disabled (the default), then C<push_write> will try to immediately	306	When disabled (the default), C<push_write> will try to immediately
188	write the data to the handle, if possible. This avoids having to register	307	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	308	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	309	be inefficient if you write multiple small chunks (on the wire, this
191	disadvantage is usually avoided by your kernel's nagle algorithm, see	310	disadvantage is usually avoided by your kernel's nagle algorithm, see
192	C<no_delay>, but this option can save costly syscalls).	311	C<no_delay>, but this option can save costly syscalls).
193		312
194	When enabled, then writes will always be queued till the next event loop	313	When enabled, writes will always be queued till the next event loop
195	iteration. This is efficient when you do many small writes per iteration,	314	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	315	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.	316	the write buffer often is full). It also increases write latency.
198		317
199	=item no_delay => <boolean>	318	=item no_delay => <boolean>
…		…
203	the Nagle algorithm, and usually it is beneficial.	322	the Nagle algorithm, and usually it is beneficial.
204		323
205	In some situations you want as low a delay as possible, which can be	324	In some situations you want as low a delay as possible, which can be
206	accomplishd by setting this option to a true value.	325	accomplishd by setting this option to a true value.
207		326
208	The default is your opertaing system's default behaviour (most likely	327	The default is your operating system's default behaviour (most likely
209	enabled), this option explicitly enables or disables it, if possible.	328	enabled). This option explicitly enables or disables it, if possible.
		329
		330	=item keepalive => <boolean>
		331
		332	Enables (default disable) the SO_KEEPALIVE option on the stream socket:
		333	normally, TCP connections have no time-out once established, so TCP
		334	connections, once established, can stay alive forever even when the other
		335	side has long gone. TCP keepalives are a cheap way to take down long-lived
		336	TCP connections when the other side becomes unreachable. While the default
		337	is OS-dependent, TCP keepalives usually kick in after around two hours,
		338	and, if the other side doesn't reply, take down the TCP connection some 10
		339	to 15 minutes later.
		340
		341	It is harmless to specify this option for file handles that do not support
		342	keepalives, and enabling it on connections that are potentially long-lived
		343	is usually a good idea.
		344
		345	=item oobinline => <boolean>
		346
		347	BSD majorly fucked up the implementation of TCP urgent data. The result
		348	is that almost no OS implements TCP according to the specs, and every OS
		349	implements it slightly differently.
		350
		351	If you want to handle TCP urgent data, then setting this flag (the default
		352	is enabled) gives you the most portable way of getting urgent data, by
		353	putting it into the stream.
		354
		355	Since BSD emulation of OOB data on top of TCP's urgent data can have
		356	security implications, AnyEvent::Handle sets this flag automatically
		357	unless explicitly specified. Note that setting this flag after
		358	establishing a connection I<may> be a bit too late (data loss could
		359	already have occured on BSD systems), but at least it will protect you
		360	from most attacks.
210		361
211	=item read_size => <bytes>	362	=item read_size => <bytes>
212		363
213	The default read block size (the amount of bytes this module will	364	The initial read block size, the number of bytes this module will try
214	try to read during each loop iteration, which affects memory	365	to read during each loop iteration. Each handle object will consume
215	requirements). Default: C<8192>.	366	at least this amount of memory for the read buffer as well, so when
		367	handling many connections watch out for memory requirements). See also
		368	C<max_read_size>. Default: C<2048>.
		369
		370	=item max_read_size => <bytes>
		371
		372	The maximum read buffer size used by the dynamic adjustment
		373	algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
		374	one go it will double C<read_size> up to the maximum given by this
		375	option. Default: C<131072> or C<read_size>, whichever is higher.
216		376
217	=item low_water_mark => <bytes>	377	=item low_water_mark => <bytes>
218		378
219	Sets the amount of bytes (default: C<0>) that make up an "empty" write	379	Sets the number of bytes (default: C<0>) that make up an "empty" write
220	buffer: If the write reaches this size or gets even samller it is	380	buffer: If the buffer reaches this size or gets even samller it is
221	considered empty.	381	considered empty.
222		382
223	Sometimes it can be beneficial (for performance reasons) to add data to	383	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	384	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	385	the operating system kernel usually buffers data as well, so the default
226	is good in almost all cases.	386	is good in almost all cases.
227		387
228	=item linger => <seconds>	388	=item linger => <seconds>
229		389
230	If non-zero (default: C<3600>), then the destructor of the	390	If this is non-zero (default: C<3600>), the destructor of the
231	AnyEvent::Handle object will check whether there is still outstanding	391	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	392	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	393	socket. No errors will be reported (this mostly matches how the operating
234	system treats outstanding data at socket close time).	394	system treats outstanding data at socket close time).
235		395
236	This will not work for partial TLS data that could not be encoded	396	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	397	yet. This data will be lost. Calling the C<stoptls> method in time might
238	help.	398	help.
239		399
		400	=item peername => $string
		401
		402	A string used to identify the remote site - usually the DNS hostname
		403	(I<not> IDN!) used to create the connection, rarely the IP address.
		404
		405	Apart from being useful in error messages, this string is also used in TLS
		406	peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
		407	verification will be skipped when C<peername> is not specified or is
		408	C<undef>.
		409
240	=item tls => "accept" | "connect" | Net::SSLeay::SSL object	410	=item tls => "accept" | "connect" | Net::SSLeay::SSL object
241		411
242	When this parameter is given, it enables TLS (SSL) mode, that means	412	When this parameter is given, it enables TLS (SSL) mode, that means
243	AnyEvent will start a TLS handshake as soon as the conenction has been	413	AnyEvent will start a TLS handshake as soon as the connection has been
244	established and will transparently encrypt/decrypt data afterwards.	414	established and will transparently encrypt/decrypt data afterwards.
		415
		416	All TLS protocol errors will be signalled as C<EPROTO>, with an
		417	appropriate error message.
245		418
246	TLS mode requires Net::SSLeay to be installed (it will be loaded	419	TLS mode requires Net::SSLeay to be installed (it will be loaded
247	automatically when you try to create a TLS handle): this module doesn't	420	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	421	have a dependency on that module, so if your module requires it, you have
249	to add the dependency yourself.	422	to add the dependency yourself.
…		…
253	mode.	426	mode.
254		427
255	You can also provide your own TLS connection object, but you have	428	You can also provide your own TLS connection object, but you have
256	to make sure that you call either C<Net::SSLeay::set_connect_state>	429	to make sure that you call either C<Net::SSLeay::set_connect_state>
257	or C<Net::SSLeay::set_accept_state> on it before you pass it to	430	or C<Net::SSLeay::set_accept_state> on it before you pass it to
258	AnyEvent::Handle.	431	AnyEvent::Handle. Also, this module will take ownership of this connection
		432	object.
259		433
		434	At some future point, AnyEvent::Handle might switch to another TLS
		435	implementation, then the option to use your own session object will go
		436	away.
		437
		438	B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
		439	passing in the wrong integer will lead to certain crash. This most often
		440	happens when one uses a stylish C<< tls => 1 >> and is surprised about the
		441	segmentation fault.
		442
260	See the C<< ->starttls >> method for when need to start TLS negotiation later.	443	Use the C<< ->starttls >> method if you need to start TLS negotiation later.
261		444
262	=item tls_ctx => $ssl_ctx	445	=item tls_ctx => $anyevent_tls
263		446
264	Use the given C<Net::SSLeay::CTX> object to create the new TLS connection	447	Use the given C<AnyEvent::TLS> object to create the new TLS connection
265	(unless a connection object was specified directly). If this parameter is	448	(unless a connection object was specified directly). If this
266	missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.	449	parameter is missing (or C<undef>), then AnyEvent::Handle will use
		450	C<AnyEvent::Handle::TLS_CTX>.
		451
		452	Instead of an object, you can also specify a hash reference with C<< key
		453	=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
		454	new TLS context object.
		455
		456	=item on_starttls => $cb->($handle, $success[, $error_message])
		457
		458	This callback will be invoked when the TLS/SSL handshake has finished. If
		459	C<$success> is true, then the TLS handshake succeeded, otherwise it failed
		460	(C<on_stoptls> will not be called in this case).
		461
		462	The session in C<< $handle->{tls} >> can still be examined in this
		463	callback, even when the handshake was not successful.
		464
		465	TLS handshake failures will not cause C<on_error> to be invoked when this
		466	callback is in effect, instead, the error message will be passed to C<on_starttls>.
		467
		468	Without this callback, handshake failures lead to C<on_error> being
		469	called as usual.
		470
		471	Note that you cannot just call C<starttls> again in this callback. If you
		472	need to do that, start an zero-second timer instead whose callback can
		473	then call C<< ->starttls >> again.
		474
		475	=item on_stoptls => $cb->($handle)
		476
		477	When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
		478	set, then it will be invoked after freeing the TLS session. If it is not,
		479	then a TLS shutdown condition will be treated like a normal EOF condition
		480	on the handle.
		481
		482	The session in C<< $handle->{tls} >> can still be examined in this
		483	callback.
		484
		485	This callback will only be called on TLS shutdowns, not when the
		486	underlying handle signals EOF.
267		487
268	=item json => JSON or JSON::XS object	488	=item json => JSON or JSON::XS object
269		489
270	This is the json coder object used by the C<json> read and write types.	490	This is the json coder object used by the C<json> read and write types.
271		491
…		…
280		500
281	=cut	501	=cut
282		502
283	sub new {	503	sub new {
284	my $class = shift;	504	my $class = shift;
285
286	my $self = bless { @_ }, $class;	505	my $self = bless { @_ }, $class;
287		506
288	$self->{fh} or Carp::croak "mandatory argument fh is missing";	507	if ($self->{fh}) {
		508	$self->_start;
		509	return unless $self->{fh}; # could be gone by now
		510
		511	} elsif ($self->{connect}) {
		512	require AnyEvent::Socket;
		513
		514	$self->{peername} = $self->{connect}[0]
		515	unless exists $self->{peername};
		516
		517	$self->{_skip_drain_rbuf} = 1;
		518
		519	{
		520	Scalar::Util::weaken (my $self = $self);
		521
		522	$self->{_connect} =
		523	AnyEvent::Socket::tcp_connect (
		524	$self->{connect}[0],
		525	$self->{connect}[1],
		526	sub {
		527	my ($fh, $host, $port, $retry) = @_;
		528
		529	delete $self->{_connect}; # no longer needed
		530
		531	if ($fh) {
		532	$self->{fh} = $fh;
		533
		534	delete $self->{_skip_drain_rbuf};
		535	$self->_start;
		536
		537	$self->{on_connect}
		538	and $self->{on_connect}($self, $host, $port, sub {
		539	delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
		540	$self->{_skip_drain_rbuf} = 1;
		541	&$retry;
		542	});
		543
		544	} else {
		545	if ($self->{on_connect_error}) {
		546	$self->{on_connect_error}($self, "$!");
		547	$self->destroy if $self;
		548	} else {
		549	$self->_error ($!, 1);
		550	}
		551	}
		552	},
		553	sub {
		554	local $self->{fh} = $_[0];
		555
		556	$self->{on_prepare}
		557	? $self->{on_prepare}->($self)
		558	: ()
		559	}
		560	);
		561	}
		562
		563	} else {
		564	Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
		565	}
		566
		567	$self
		568	}
		569
		570	sub _start {
		571	my ($self) = @_;
		572
		573	# too many clueless people try to use udp and similar sockets
		574	# with AnyEvent::Handle, do them a favour.
		575	my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
		576	Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
		577	if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
289		578
290	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;	579	AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
291		580
		581	$self->{_activity} =
		582	$self->{_ractivity} =
		583	$self->{_wactivity} = AE::now;
		584
		585	$self->{read_size} ||= 2048;
		586	$self->{max_read_size} = $self->{read_size}
		587	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
		588
		589	$self->timeout (delete $self->{timeout} ) if $self->{timeout};
		590	$self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
		591	$self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
		592
		593	$self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
		594	$self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
		595
		596	$self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
		597
292	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})	598	$self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
293	if $self->{tls};	599	if $self->{tls};
294		600
295	$self->{_activity} = AnyEvent->now;
296	$self->_timeout;
297
298	$self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};	601	$self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
299	$self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
300		602
301	$self->start_read	603	$self->start_read
302	if $self->{on_read};	604	if $self->{on_read} || @{ $self->{_queue} };
303		605
304	$self	606	$self->_drain_wbuf;
305	}
306
307	sub _shutdown {
308	my ($self) = @_;
309
310	delete $self->{_tw};
311	delete $self->{_rw};
312	delete $self->{_ww};
313	delete $self->{fh};
314
315	&_freetls;
316
317	delete $self->{on_read};
318	delete $self->{_queue};
319	}	607	}
320		608
321	sub _error {	609	sub _error {
322	my ($self, $errno, $fatal) = @_;	610	my ($self, $errno, $fatal, $message) = @_;
323
324	$self->_shutdown
325	if $fatal;
326		611
327	$! = $errno;	612	$! = $errno;
		613	$message ||= "$!";
328		614
329	if ($self->{on_error}) {	615	if ($self->{on_error}) {
330	$self->{on_error}($self, $fatal);	616	$self->{on_error}($self, $fatal, $message);
331	} elsif ($self->{fh}) {	617	$self->destroy if $fatal;
		618	} elsif ($self->{fh} || $self->{connect}) {
		619	$self->destroy;
332	Carp::croak "AnyEvent::Handle uncaught error: $!";	620	Carp::croak "AnyEvent::Handle uncaught error: $message";
333	}	621	}
334	}	622	}
335		623
336	=item $fh = $handle->fh	624	=item $fh = $handle->fh
337		625
…		…
361	$_[0]{on_eof} = $_[1];	649	$_[0]{on_eof} = $_[1];
362	}	650	}
363		651
364	=item $handle->on_timeout ($cb)	652	=item $handle->on_timeout ($cb)
365		653
366	Replace the current C<on_timeout> callback, or disables the callback (but	654	=item $handle->on_rtimeout ($cb)
367	not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
368	argument and method.
369		655
370	=cut	656	=item $handle->on_wtimeout ($cb)
371		657
372	sub on_timeout {	658	Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
373	$_[0]{on_timeout} = $_[1];	659	callback, or disables the callback (but not the timeout) if C<$cb> =
374	}	660	C<undef>. See the C<timeout> constructor argument and method.
		661
		662	=cut
		663
		664	# see below
375		665
376	=item $handle->autocork ($boolean)	666	=item $handle->autocork ($boolean)
377		667
378	Enables or disables the current autocork behaviour (see C<autocork>	668	Enables or disables the current autocork behaviour (see C<autocork>
379	constructor argument). Changes will only take effect on the next write.	669	constructor argument). Changes will only take effect on the next write.
…		…
392	=cut	682	=cut
393		683
394	sub no_delay {	684	sub no_delay {
395	$_[0]{no_delay} = $_[1];	685	$_[0]{no_delay} = $_[1];
396		686
		687	setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
		688	if $_[0]{fh};
		689	}
		690
		691	=item $handle->keepalive ($boolean)
		692
		693	Enables or disables the C<keepalive> setting (see constructor argument of
		694	the same name for details).
		695
		696	=cut
		697
		698	sub keepalive {
		699	$_[0]{keepalive} = $_[1];
		700
397	eval {	701	eval {
398	local $SIG{__DIE__};	702	local $SIG{__DIE__};
399	setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];	703	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		704	if $_[0]{fh};
400	};	705	};
401	}	706	}
402		707
		708	=item $handle->oobinline ($boolean)
		709
		710	Enables or disables the C<oobinline> setting (see constructor argument of
		711	the same name for details).
		712
		713	=cut
		714
		715	sub oobinline {
		716	$_[0]{oobinline} = $_[1];
		717
		718	eval {
		719	local $SIG{__DIE__};
		720	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
		721	if $_[0]{fh};
		722	};
		723	}
		724
		725	=item $handle->keepalive ($boolean)
		726
		727	Enables or disables the C<keepalive> setting (see constructor argument of
		728	the same name for details).
		729
		730	=cut
		731
		732	sub keepalive {
		733	$_[0]{keepalive} = $_[1];
		734
		735	eval {
		736	local $SIG{__DIE__};
		737	setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
		738	if $_[0]{fh};
		739	};
		740	}
		741
		742	=item $handle->on_starttls ($cb)
		743
		744	Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
		745
		746	=cut
		747
		748	sub on_starttls {
		749	$_[0]{on_starttls} = $_[1];
		750	}
		751
		752	=item $handle->on_stoptls ($cb)
		753
		754	Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
		755
		756	=cut
		757
		758	sub on_stoptls {
		759	$_[0]{on_stoptls} = $_[1];
		760	}
		761
		762	=item $handle->rbuf_max ($max_octets)
		763
		764	Configures the C<rbuf_max> setting (C<undef> disables it).
		765
		766	=item $handle->wbuf_max ($max_octets)
		767
		768	Configures the C<wbuf_max> setting (C<undef> disables it).
		769
		770	=cut
		771
		772	sub rbuf_max {
		773	$_[0]{rbuf_max} = $_[1];
		774	}
		775
		776	sub wbuf_max {
		777	$_[0]{wbuf_max} = $_[1];
		778	}
		779
403	#############################################################################	780	#############################################################################
404		781
405	=item $handle->timeout ($seconds)	782	=item $handle->timeout ($seconds)
406		783
		784	=item $handle->rtimeout ($seconds)
		785
		786	=item $handle->wtimeout ($seconds)
		787
407	Configures (or disables) the inactivity timeout.	788	Configures (or disables) the inactivity timeout.
408		789
409	=cut	790	The timeout will be checked instantly, so this method might destroy the
		791	handle before it returns.
410		792
411	sub timeout {	793	=item $handle->timeout_reset
		794
		795	=item $handle->rtimeout_reset
		796
		797	=item $handle->wtimeout_reset
		798
		799	Reset the activity timeout, as if data was received or sent.
		800
		801	These methods are cheap to call.
		802
		803	=cut
		804
		805	for my $dir ("", "r", "w") {
		806	my $timeout = "${dir}timeout";
		807	my $tw = "_${dir}tw";
		808	my $on_timeout = "on_${dir}timeout";
		809	my $activity = "_${dir}activity";
		810	my $cb;
		811
		812	*$on_timeout = sub {
		813	$_[0]{$on_timeout} = $_[1];
		814	};
		815
		816	*$timeout = sub {
412	my ($self, $timeout) = @_;	817	my ($self, $new_value) = @_;
413		818
		819	$new_value >= 0
		820	or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
		821
414	$self->{timeout} = $timeout;	822	$self->{$timeout} = $new_value;
415	$self->_timeout;	823	delete $self->{$tw}; &$cb;
416	}	824	};
417		825
		826	*{"${dir}timeout_reset"} = sub {
		827	$_[0]{$activity} = AE::now;
		828	};
		829
		830	# main workhorse:
418	# reset the timeout watcher, as neccessary	831	# reset the timeout watcher, as neccessary
419	# also check for time-outs	832	# also check for time-outs
420	sub _timeout {	833	$cb = sub {
421	my ($self) = @_;	834	my ($self) = @_;
422		835
423	if ($self->{timeout}) {	836	if ($self->{$timeout} && $self->{fh}) {
424	my $NOW = AnyEvent->now;	837	my $NOW = AE::now;
425		838
426	# when would the timeout trigger?	839	# when would the timeout trigger?
427	my $after = $self->{_activity} + $self->{timeout} - $NOW;	840	my $after = $self->{$activity} + $self->{$timeout} - $NOW;
428		841
429	# now or in the past already?	842	# now or in the past already?
430	if ($after <= 0) {	843	if ($after <= 0) {
431	$self->{_activity} = $NOW;	844	$self->{$activity} = $NOW;
432		845
433	if ($self->{on_timeout}) {	846	if ($self->{$on_timeout}) {
434	$self->{on_timeout}($self);	847	$self->{$on_timeout}($self);
435	} else {	848	} else {
436	$self->_error (&Errno::ETIMEDOUT);	849	$self->_error (Errno::ETIMEDOUT);
		850	}
		851
		852	# callback could have changed timeout value, optimise
		853	return unless $self->{$timeout};
		854
		855	# calculate new after
		856	$after = $self->{$timeout};
437	}	857	}
438		858
439	# callback could have changed timeout value, optimise	859	Scalar::Util::weaken $self;
440	return unless $self->{timeout};	860	return unless $self; # ->error could have destroyed $self
441		861
442	# calculate new after	862	$self->{$tw} ||= AE::timer $after, 0, sub {
443	$after = $self->{timeout};	863	delete $self->{$tw};
		864	$cb->($self);
		865	};
		866	} else {
		867	delete $self->{$tw};
444	}	868	}
445
446	Scalar::Util::weaken $self;
447	return unless $self; # ->error could have destroyed $self
448
449	$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
450	delete $self->{_tw};
451	$self->_timeout;
452	});
453	} else {
454	delete $self->{_tw};
455	}	869	}
456	}	870	}
457		871
458	#############################################################################	872	#############################################################################
459		873
…		…
475	=item $handle->on_drain ($cb)	889	=item $handle->on_drain ($cb)
476		890
477	Sets the C<on_drain> callback or clears it (see the description of	891	Sets the C<on_drain> callback or clears it (see the description of
478	C<on_drain> in the constructor).	892	C<on_drain> in the constructor).
479		893
		894	This method may invoke callbacks (and therefore the handle might be
		895	destroyed after it returns).
		896
480	=cut	897	=cut
481		898
482	sub on_drain {	899	sub on_drain {
483	my ($self, $cb) = @_;	900	my ($self, $cb) = @_;
484		901
…		…
488	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});	905	if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
489	}	906	}
490		907
491	=item $handle->push_write ($data)	908	=item $handle->push_write ($data)
492		909
493	Queues the given scalar to be written. You can push as much data as you	910	Queues the given scalar to be written. You can push as much data as
494	want (only limited by the available memory), as C<AnyEvent::Handle>	911	you want (only limited by the available memory and C<wbuf_max>), as
495	buffers it independently of the kernel.	912	C<AnyEvent::Handle> buffers it independently of the kernel.
		913
		914	This method may invoke callbacks (and therefore the handle might be
		915	destroyed after it returns).
496		916
497	=cut	917	=cut
498		918
499	sub _drain_wbuf {	919	sub _drain_wbuf {
500	my ($self) = @_;	920	my ($self) = @_;
…		…
504	Scalar::Util::weaken $self;	924	Scalar::Util::weaken $self;
505		925
506	my $cb = sub {	926	my $cb = sub {
507	my $len = syswrite $self->{fh}, $self->{wbuf};	927	my $len = syswrite $self->{fh}, $self->{wbuf};
508		928
509	if ($len >= 0) {	929	if (defined $len) {
510	substr $self->{wbuf}, 0, $len, "";	930	substr $self->{wbuf}, 0, $len, "";
511		931
512	$self->{_activity} = AnyEvent->now;	932	$self->{_activity} = $self->{_wactivity} = AE::now;
513		933
514	$self->{on_drain}($self)	934	$self->{on_drain}($self)
515	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})	935	if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
516	&& $self->{on_drain};	936	&& $self->{on_drain};
517		937
…		…
523		943
524	# try to write data immediately	944	# try to write data immediately
525	$cb->() unless $self->{autocork};	945	$cb->() unless $self->{autocork};
526		946
527	# if still data left in wbuf, we need to poll	947	# if still data left in wbuf, we need to poll
528	$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)	948	$self->{_ww} = AE::io $self->{fh}, 1, $cb
529	if length $self->{wbuf};	949	if length $self->{wbuf};
		950
		951	if (
		952	defined $self->{wbuf_max}
		953	&& $self->{wbuf_max} < length $self->{wbuf}
		954	) {
		955	$self->_error (Errno::ENOSPC, 1), return;
		956	}
530	};	957	};
531	}	958	}
532		959
533	our %WH;	960	our %WH;
534		961
		962	# deprecated
535	sub register_write_type($$) {	963	sub register_write_type($$) {
536	$WH{$_[0]} = $_[1];	964	$WH{$_[0]} = $_[1];
537	}	965	}
538		966
539	sub push_write {	967	sub push_write {
540	my $self = shift;	968	my $self = shift;
541		969
542	if (@_ > 1) {	970	if (@_ > 1) {
543	my $type = shift;	971	my $type = shift;
544		972
		973	@_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
545	@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")	974	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
546	->($self, @_);	975	->($self, @_);
547	}	976	}
548		977
		978	# we downgrade here to avoid hard-to-track-down bugs,
		979	# and diagnose the problem earlier and better.
		980
549	if ($self->{tls}) {	981	if ($self->{tls}) {
550	$self->{_tls_wbuf} .= $_[0];	982	utf8::downgrade $self->{_tls_wbuf} .= $_[0];
551		983	&_dotls ($self) if $self->{fh};
552	&_dotls ($self);
553	} else {	984	} else {
554	$self->{wbuf} .= $_[0];	985	utf8::downgrade $self->{wbuf} .= $_[0];
555	$self->_drain_wbuf;	986	$self->_drain_wbuf if $self->{fh};
556	}	987	}
557	}	988	}
558		989
559	=item $handle->push_write (type => @args)	990	=item $handle->push_write (type => @args)
560		991
561	Instead of formatting your data yourself, you can also let this module do	992	Instead of formatting your data yourself, you can also let this module
562	the job by specifying a type and type-specific arguments.	993	do the job by specifying a type and type-specific arguments. You
		994	can also specify the (fully qualified) name of a package, in which
		995	case AnyEvent tries to load the package and then expects to find the
		996	C<anyevent_write_type> function inside (see "custom write types", below).
563		997
564	Predefined types are (if you have ideas for additional types, feel free to	998	Predefined types are (if you have ideas for additional types, feel free to
565	drop by and tell us):	999	drop by and tell us):
566		1000
567	=over 4	1001	=over 4
…		…
624	Other languages could read single lines terminated by a newline and pass	1058	Other languages could read single lines terminated by a newline and pass
625	this line into their JSON decoder of choice.	1059	this line into their JSON decoder of choice.
626		1060
627	=cut	1061	=cut
628		1062
		1063	sub json_coder() {
		1064	eval { require JSON::XS; JSON::XS->new->utf8 }
		1065	|| do { require JSON; JSON->new->utf8 }
		1066	}
		1067
629	register_write_type json => sub {	1068	register_write_type json => sub {
630	my ($self, $ref) = @_;	1069	my ($self, $ref) = @_;
631		1070
632	require JSON;	1071	my $json = $self->{json} ||= json_coder;
633		1072
634	$self->{json} ? $self->{json}->encode ($ref)	1073	$json->encode ($ref)
635	: JSON::encode_json ($ref)
636	};	1074	};
637		1075
638	=item storable => $reference	1076	=item storable => $reference
639		1077
640	Freezes the given reference using L<Storable> and writes it to the	1078	Freezes the given reference using L<Storable> and writes it to the
…		…
650	pack "w/a*", Storable::nfreeze ($ref)	1088	pack "w/a*", Storable::nfreeze ($ref)
651	};	1089	};
652		1090
653	=back	1091	=back
654		1092
655	=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)	1093	=item $handle->push_shutdown
656		1094
657	This function (not method) lets you add your own types to C<push_write>.	1095	Sometimes you know you want to close the socket after writing your data
		1096	before it was actually written. One way to do that is to replace your
		1097	C<on_drain> handler by a callback that shuts down the socket (and set
		1098	C<low_water_mark> to C<0>). This method is a shorthand for just that, and
		1099	replaces the C<on_drain> callback with:
		1100
		1101	sub { shutdown $_[0]{fh}, 1 }
		1102
		1103	This simply shuts down the write side and signals an EOF condition to the
		1104	the peer.
		1105
		1106	You can rely on the normal read queue and C<on_eof> handling
		1107	afterwards. This is the cleanest way to close a connection.
		1108
		1109	This method may invoke callbacks (and therefore the handle might be
		1110	destroyed after it returns).
		1111
		1112	=cut
		1113
		1114	sub push_shutdown {
		1115	my ($self) = @_;
		1116
		1117	delete $self->{low_water_mark};
		1118	$self->on_drain (sub { shutdown $_[0]{fh}, 1 });
		1119	}
		1120
		1121	=item custom write types - Package::anyevent_write_type $handle, @args
		1122
		1123	Instead of one of the predefined types, you can also specify the name of
		1124	a package. AnyEvent will try to load the package and then expects to find
		1125	a function named C<anyevent_write_type> inside. If it isn't found, it
		1126	progressively tries to load the parent package until it either finds the
		1127	function (good) or runs out of packages (bad).
		1128
658	Whenever the given C<type> is used, C<push_write> will invoke the code	1129	Whenever the given C<type> is used, C<push_write> will the function with
659	reference with the handle object and the remaining arguments.	1130	the handle object and the remaining arguments.
660		1131
661	The code reference is supposed to return a single octet string that will	1132	The function is supposed to return a single octet string that will be
662	be appended to the write buffer.	1133	appended to the write buffer, so you cna mentally treat this function as a
		1134	"arguments to on-the-wire-format" converter.
663		1135
664	Note that this is a function, and all types registered this way will be	1136	Example: implement a custom write type C<join> that joins the remaining
665	global, so try to use unique names.	1137	arguments using the first one.
		1138
		1139	$handle->push_write (My::Type => " ", 1,2,3);
		1140
		1141	# uses the following package, which can be defined in the "My::Type" or in
		1142	# the "My" modules to be auto-loaded, or just about anywhere when the
		1143	# My::Type::anyevent_write_type is defined before invoking it.
		1144
		1145	package My::Type;
		1146
		1147	sub anyevent_write_type {
		1148	my ($handle, $delim, @args) = @_;
		1149
		1150	join $delim, @args
		1151	}
666		1152
667	=cut	1153	=cut
668		1154
669	#############################################################################	1155	#############################################################################
670		1156
…		…
679	ways, the "simple" way, using only C<on_read> and the "complex" way, using	1165	ways, the "simple" way, using only C<on_read> and the "complex" way, using
680	a queue.	1166	a queue.
681		1167
682	In the simple case, you just install an C<on_read> callback and whenever	1168	In the simple case, you just install an C<on_read> callback and whenever
683	new data arrives, it will be called. You can then remove some data (if	1169	new data arrives, it will be called. You can then remove some data (if
684	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna	1170	enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
685	leave the data there if you want to accumulate more (e.g. when only a	1171	leave the data there if you want to accumulate more (e.g. when only a
686	partial message has been received so far).	1172	partial message has been received so far), or change the read queue with
		1173	e.g. C<push_read>.
687		1174
688	In the more complex case, you want to queue multiple callbacks. In this	1175	In the more complex case, you want to queue multiple callbacks. In this
689	case, AnyEvent::Handle will call the first queued callback each time new	1176	case, AnyEvent::Handle will call the first queued callback each time new
690	data arrives (also the first time it is queued) and removes it when it has	1177	data arrives (also the first time it is queued) and remove it when it has
691	done its job (see C<push_read>, below).	1178	done its job (see C<push_read>, below).
692		1179
693	This way you can, for example, push three line-reads, followed by reading	1180	This way you can, for example, push three line-reads, followed by reading
694	a chunk of data, and AnyEvent::Handle will execute them in order.	1181	a chunk of data, and AnyEvent::Handle will execute them in order.
695		1182
…		…
752	=cut	1239	=cut
753		1240
754	sub _drain_rbuf {	1241	sub _drain_rbuf {
755	my ($self) = @_;	1242	my ($self) = @_;
756		1243
		1244	# avoid recursion
		1245	return if $self->{_skip_drain_rbuf};
757	local $self->{_in_drain} = 1;	1246	local $self->{_skip_drain_rbuf} = 1;
758
759	if (
760	defined $self->{rbuf_max}
761	&& $self->{rbuf_max} < length $self->{rbuf}
762	) {
763	$self->_error (&Errno::ENOSPC, 1), return;
764	}
765		1247
766	while () {	1248	while () {
		1249	# we need to use a separate tls read buffer, as we must not receive data while
		1250	# we are draining the buffer, and this can only happen with TLS.
		1251	$self->{rbuf} .= delete $self->{_tls_rbuf}
		1252	if exists $self->{_tls_rbuf};
		1253
767	my $len = length $self->{rbuf};	1254	my $len = length $self->{rbuf};
768		1255
769	if (my $cb = shift @{ $self->{_queue} }) {	1256	if (my $cb = shift @{ $self->{_queue} }) {
770	unless ($cb->($self)) {	1257	unless ($cb->($self)) {
771	if ($self->{_eof}) {	1258	# no progress can be made
772	# no progress can be made (not enough data and no data forthcoming)	1259	# (not enough data and no data forthcoming)
773	$self->_error (&Errno::EPIPE, 1), return;	1260	$self->_error (Errno::EPIPE, 1), return
774	}	1261	if $self->{_eof};
775		1262
776	unshift @{ $self->{_queue} }, $cb;	1263	unshift @{ $self->{_queue} }, $cb;
777	last;	1264	last;
778	}	1265	}
779	} elsif ($self->{on_read}) {	1266	} elsif ($self->{on_read}) {
…		…
786	&& !@{ $self->{_queue} } # and the queue is still empty	1273	&& !@{ $self->{_queue} } # and the queue is still empty
787	&& $self->{on_read} # but we still have on_read	1274	&& $self->{on_read} # but we still have on_read
788	) {	1275	) {
789	# no further data will arrive	1276	# no further data will arrive
790	# so no progress can be made	1277	# so no progress can be made
791	$self->_error (&Errno::EPIPE, 1), return	1278	$self->_error (Errno::EPIPE, 1), return
792	if $self->{_eof};	1279	if $self->{_eof};
793		1280
794	last; # more data might arrive	1281	last; # more data might arrive
795	}	1282	}
796	} else {	1283	} else {
…		…
799	last;	1286	last;
800	}	1287	}
801	}	1288	}
802		1289
803	if ($self->{_eof}) {	1290	if ($self->{_eof}) {
804	if ($self->{on_eof}) {	1291	$self->{on_eof}
805	$self->{on_eof}($self)	1292	? $self->{on_eof}($self)
806	} else {	1293	: $self->_error (0, 1, "Unexpected end-of-file");
807	$self->_error (0, 1);	1294
808	}	1295	return;
		1296	}
		1297
		1298	if (
		1299	defined $self->{rbuf_max}
		1300	&& $self->{rbuf_max} < length $self->{rbuf}
		1301	) {
		1302	$self->_error (Errno::ENOSPC, 1), return;
809	}	1303	}
810		1304
811	# may need to restart read watcher	1305	# may need to restart read watcher
812	unless ($self->{_rw}) {	1306	unless ($self->{_rw}) {
813	$self->start_read	1307	$self->start_read
…		…
819		1313
820	This replaces the currently set C<on_read> callback, or clears it (when	1314	This replaces the currently set C<on_read> callback, or clears it (when
821	the new callback is C<undef>). See the description of C<on_read> in the	1315	the new callback is C<undef>). See the description of C<on_read> in the
822	constructor.	1316	constructor.
823		1317
		1318	This method may invoke callbacks (and therefore the handle might be
		1319	destroyed after it returns).
		1320
824	=cut	1321	=cut
825		1322
826	sub on_read {	1323	sub on_read {
827	my ($self, $cb) = @_;	1324	my ($self, $cb) = @_;
828		1325
829	$self->{on_read} = $cb;	1326	$self->{on_read} = $cb;
830	$self->_drain_rbuf if $cb && !$self->{_in_drain};	1327	$self->_drain_rbuf if $cb;
831	}	1328	}
832		1329
833	=item $handle->rbuf	1330	=item $handle->rbuf
834		1331
835	Returns the read buffer (as a modifiable lvalue).	1332	Returns the read buffer (as a modifiable lvalue). You can also access the
		1333	read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
		1334	much faster, and no less clean).
836		1335
837	You can access the read buffer directly as the C<< ->{rbuf} >> member, if	1336	The only operation allowed on the read buffer (apart from looking at it)
838	you want.	1337	is removing data from its beginning. Otherwise modifying or appending to
		1338	it is not allowed and will lead to hard-to-track-down bugs.
839		1339
840	NOTE: The read buffer should only be used or modified if the C<on_read>,	1340	NOTE: The read buffer should only be used or modified in the C<on_read>
841	C<push_read> or C<unshift_read> methods are used. The other read methods	1341	callback or when C<push_read> or C<unshift_read> are used with a single
842	automatically manage the read buffer.	1342	callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
		1343	will manage the read buffer on their own.
843		1344
844	=cut	1345	=cut
845		1346
846	sub rbuf : lvalue {	1347	sub rbuf : lvalue {
847	$_[0]{rbuf}	1348	$_[0]{rbuf}
…		…
864		1365
865	If enough data was available, then the callback must remove all data it is	1366	If enough data was available, then the callback must remove all data it is
866	interested in (which can be none at all) and return a true value. After returning	1367	interested in (which can be none at all) and return a true value. After returning
867	true, it will be removed from the queue.	1368	true, it will be removed from the queue.
868		1369
		1370	These methods may invoke callbacks (and therefore the handle might be
		1371	destroyed after it returns).
		1372
869	=cut	1373	=cut
870		1374
871	our %RH;	1375	our %RH;
872		1376
873	sub register_read_type($$) {	1377	sub register_read_type($$) {
…		…
879	my $cb = pop;	1383	my $cb = pop;
880		1384
881	if (@_) {	1385	if (@_) {
882	my $type = shift;	1386	my $type = shift;
883		1387
		1388	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
884	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")	1389	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
885	->($self, $cb, @_);	1390	->($self, $cb, @_);
886	}	1391	}
887		1392
888	push @{ $self->{_queue} }, $cb;	1393	push @{ $self->{_queue} }, $cb;
889	$self->_drain_rbuf unless $self->{_in_drain};	1394	$self->_drain_rbuf;
890	}	1395	}
891		1396
892	sub unshift_read {	1397	sub unshift_read {
893	my $self = shift;	1398	my $self = shift;
894	my $cb = pop;	1399	my $cb = pop;
895		1400
896	if (@_) {	1401	if (@_) {
897	my $type = shift;	1402	my $type = shift;
898		1403
		1404	$cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
899	$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")	1405	or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
900	->($self, $cb, @_);	1406	->($self, $cb, @_);
901	}	1407	}
902		1408
903
904	unshift @{ $self->{_queue} }, $cb;	1409	unshift @{ $self->{_queue} }, $cb;
905	$self->_drain_rbuf unless $self->{_in_drain};	1410	$self->_drain_rbuf;
906	}	1411	}
907		1412
908	=item $handle->push_read (type => @args, $cb)	1413	=item $handle->push_read (type => @args, $cb)
909		1414
910	=item $handle->unshift_read (type => @args, $cb)	1415	=item $handle->unshift_read (type => @args, $cb)
911		1416
912	Instead of providing a callback that parses the data itself you can chose	1417	Instead of providing a callback that parses the data itself you can chose
913	between a number of predefined parsing formats, for chunks of data, lines	1418	between a number of predefined parsing formats, for chunks of data, lines
914	etc.	1419	etc. You can also specify the (fully qualified) name of a package, in
		1420	which case AnyEvent tries to load the package and then expects to find the
		1421	C<anyevent_read_type> function inside (see "custom read types", below).
915		1422
916	Predefined types are (if you have ideas for additional types, feel free to	1423	Predefined types are (if you have ideas for additional types, feel free to
917	drop by and tell us):	1424	drop by and tell us):
918		1425
919	=over 4	1426	=over 4
…		…
925	data.	1432	data.
926		1433
927	Example: read 2 bytes.	1434	Example: read 2 bytes.
928		1435
929	$handle->push_read (chunk => 2, sub {	1436	$handle->push_read (chunk => 2, sub {
930	warn "yay ", unpack "H*", $_[1];	1437	AE::log debug => "yay " . unpack "H*", $_[1];
931	});	1438	});
932		1439
933	=cut	1440	=cut
934		1441
935	register_read_type chunk => sub {	1442	register_read_type chunk => sub {
…		…
1011	the receive buffer when neither C<$accept> nor C<$reject> match,	1518	the receive buffer when neither C<$accept> nor C<$reject> match,
1012	and everything preceding and including the match will be accepted	1519	and everything preceding and including the match will be accepted
1013	unconditionally. This is useful to skip large amounts of data that you	1520	unconditionally. This is useful to skip large amounts of data that you
1014	know cannot be matched, so that the C<$accept> or C<$reject> regex do not	1521	know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1015	have to start matching from the beginning. This is purely an optimisation	1522	have to start matching from the beginning. This is purely an optimisation
1016	and is usually worth only when you expect more than a few kilobytes.	1523	and is usually worth it only when you expect more than a few kilobytes.
1017		1524
1018	Example: expect a http header, which ends at C<\015\012\015\012>. Since we	1525	Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1019	expect the header to be very large (it isn't in practise, but...), we use	1526	expect the header to be very large (it isn't in practice, but...), we use
1020	a skip regex to skip initial portions. The skip regex is tricky in that	1527	a skip regex to skip initial portions. The skip regex is tricky in that
1021	it only accepts something not ending in either \015 or \012, as these are	1528	it only accepts something not ending in either \015 or \012, as these are
1022	required for the accept regex.	1529	required for the accept regex.
1023		1530
1024	$handle->push_read (regex =>	1531	$handle->push_read (regex =>
…		…
1037		1544
1038	sub {	1545	sub {
1039	# accept	1546	# accept
1040	if ($$rbuf =~ $accept) {	1547	if ($$rbuf =~ $accept) {
1041	$data .= substr $$rbuf, 0, $+[0], "";	1548	$data .= substr $$rbuf, 0, $+[0], "";
1042	$cb->($self, $data);	1549	$cb->($_[0], $data);
1043	return 1;	1550	return 1;
1044	}	1551	}
1045		1552
1046	# reject	1553	# reject
1047	if ($reject && $$rbuf =~ $reject) {	1554	if ($reject && $$rbuf =~ $reject) {
1048	$self->_error (&Errno::EBADMSG);	1555	$_[0]->_error (Errno::EBADMSG);
1049	}	1556	}
1050		1557
1051	# skip	1558	# skip
1052	if ($skip && $$rbuf =~ $skip) {	1559	if ($skip && $$rbuf =~ $skip) {
1053	$data .= substr $$rbuf, 0, $+[0], "";	1560	$data .= substr $$rbuf, 0, $+[0], "";
…		…
1069	my ($self, $cb) = @_;	1576	my ($self, $cb) = @_;
1070		1577
1071	sub {	1578	sub {
1072	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {	1579	unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1073	if ($_[0]{rbuf} =~ /[^0-9]/) {	1580	if ($_[0]{rbuf} =~ /[^0-9]/) {
1074	$self->_error (&Errno::EBADMSG);	1581	$_[0]->_error (Errno::EBADMSG);
1075	}	1582	}
1076	return;	1583	return;
1077	}	1584	}
1078		1585
1079	my $len = $1;	1586	my $len = $1;
1080		1587
1081	$self->unshift_read (chunk => $len, sub {	1588	$_[0]->unshift_read (chunk => $len, sub {
1082	my $string = $_[1];	1589	my $string = $_[1];
1083	$_[0]->unshift_read (chunk => 1, sub {	1590	$_[0]->unshift_read (chunk => 1, sub {
1084	if ($_[1] eq ",") {	1591	if ($_[1] eq ",") {
1085	$cb->($_[0], $string);	1592	$cb->($_[0], $string);
1086	} else {	1593	} else {
1087	$self->_error (&Errno::EBADMSG);	1594	$_[0]->_error (Errno::EBADMSG);
1088	}	1595	}
1089	});	1596	});
1090	});	1597	});
1091		1598
1092	1	1599	1
…		…
1139	}	1646	}
1140	};	1647	};
1141		1648
1142	=item json => $cb->($handle, $hash_or_arrayref)	1649	=item json => $cb->($handle, $hash_or_arrayref)
1143		1650
1144	Reads a JSON object or array, decodes it and passes it to the callback.	1651	Reads a JSON object or array, decodes it and passes it to the
		1652	callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1145		1653
1146	If a C<json> object was passed to the constructor, then that will be used	1654	If a C<json> object was passed to the constructor, then that will be used
1147	for the final decode, otherwise it will create a JSON coder expecting UTF-8.	1655	for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1148		1656
1149	This read type uses the incremental parser available with JSON version	1657	This read type uses the incremental parser available with JSON version
…		…
1158	=cut	1666	=cut
1159		1667
1160	register_read_type json => sub {	1668	register_read_type json => sub {
1161	my ($self, $cb) = @_;	1669	my ($self, $cb) = @_;
1162		1670
1163	require JSON;	1671	my $json = $self->{json} ||= json_coder;
1164		1672
1165	my $data;	1673	my $data;
1166	my $rbuf = \$self->{rbuf};	1674	my $rbuf = \$self->{rbuf};
1167		1675
1168	my $json = $self->{json} ||= JSON->new->utf8;
1169
1170	sub {	1676	sub {
1171	my $ref = $json->incr_parse ($self->{rbuf});	1677	my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1172		1678
1173	if ($ref) {	1679	if ($ref) {
1174	$self->{rbuf} = $json->incr_text;	1680	$_[0]{rbuf} = $json->incr_text;
1175	$json->incr_text = "";	1681	$json->incr_text = "";
1176	$cb->($self, $ref);	1682	$cb->($_[0], $ref);
1177		1683
1178	1	1684	1
		1685	} elsif ($@) {
		1686	# error case
		1687	$json->incr_skip;
		1688
		1689	$_[0]{rbuf} = $json->incr_text;
		1690	$json->incr_text = "";
		1691
		1692	$_[0]->_error (Errno::EBADMSG);
		1693
		1694	()
1179	} else {	1695	} else {
1180	$self->{rbuf} = "";	1696	$_[0]{rbuf} = "";
		1697
1181	()	1698	()
1182	}	1699	}
1183	}	1700	}
1184	};	1701	};
1185		1702
…		…
1217	# read remaining chunk	1734	# read remaining chunk
1218	$_[0]->unshift_read (chunk => $len, sub {	1735	$_[0]->unshift_read (chunk => $len, sub {
1219	if (my $ref = eval { Storable::thaw ($_[1]) }) {	1736	if (my $ref = eval { Storable::thaw ($_[1]) }) {
1220	$cb->($_[0], $ref);	1737	$cb->($_[0], $ref);
1221	} else {	1738	} else {
1222	$self->_error (&Errno::EBADMSG);	1739	$_[0]->_error (Errno::EBADMSG);
1223	}	1740	}
1224	});	1741	});
1225	}	1742	}
1226		1743
1227	1	1744	1
1228	}	1745	}
1229	};	1746	};
1230		1747
1231	=back	1748	=back
1232		1749
1233	=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)	1750	=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1234		1751
1235	This function (not method) lets you add your own types to C<push_read>.	1752	Instead of one of the predefined types, you can also specify the name
		1753	of a package. AnyEvent will try to load the package and then expects to
		1754	find a function named C<anyevent_read_type> inside. If it isn't found, it
		1755	progressively tries to load the parent package until it either finds the
		1756	function (good) or runs out of packages (bad).
1236		1757
1237	Whenever the given C<type> is used, C<push_read> will invoke the code	1758	Whenever this type is used, C<push_read> will invoke the function with the
1238	reference with the handle object, the callback and the remaining	1759	handle object, the original callback and the remaining arguments.
1239	arguments.
1240		1760
1241	The code reference is supposed to return a callback (usually a closure)	1761	The function is supposed to return a callback (usually a closure) that
1242	that works as a plain read callback (see C<< ->push_read ($cb) >>).	1762	works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
		1763	mentally treat the function as a "configurable read type to read callback"
		1764	converter.
1243		1765
1244	It should invoke the passed callback when it is done reading (remember to	1766	It should invoke the original callback when it is done reading (remember
1245	pass C<$handle> as first argument as all other callbacks do that).	1767	to pass C<$handle> as first argument as all other callbacks do that,
		1768	although there is no strict requirement on this).
1246		1769
1247	Note that this is a function, and all types registered this way will be
1248	global, so try to use unique names.
1249
1250	For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,	1770	For examples, see the source of this module (F<perldoc -m
1251	search for C<register_read_type>)).	1771	AnyEvent::Handle>, search for C<register_read_type>)).
1252		1772
1253	=item $handle->stop_read	1773	=item $handle->stop_read
1254		1774
1255	=item $handle->start_read	1775	=item $handle->start_read
1256		1776
…		…
1262	Note that AnyEvent::Handle will automatically C<start_read> for you when	1782	Note that AnyEvent::Handle will automatically C<start_read> for you when
1263	you change the C<on_read> callback or push/unshift a read callback, and it	1783	you change the C<on_read> callback or push/unshift a read callback, and it
1264	will automatically C<stop_read> for you when neither C<on_read> is set nor	1784	will automatically C<stop_read> for you when neither C<on_read> is set nor
1265	there are any read requests in the queue.	1785	there are any read requests in the queue.
1266		1786
1267	These methods will have no effect when in TLS mode (as TLS doesn't support	1787	In older versions of this module (<= 5.3), these methods had no effect,
1268	half-duplex connections).	1788	as TLS does not support half-duplex connections. In current versions they
		1789	work as expected, as this behaviour is required to avoid certain resource
		1790	attacks, where the program would be forced to read (and buffer) arbitrary
		1791	amounts of data before being able to send some data. The drawback is that
		1792	some readings of the the SSL/TLS specifications basically require this
		1793	attack to be working, as SSL/TLS implementations might stall sending data
		1794	during a rehandshake.
		1795
		1796	As a guideline, during the initial handshake, you should not stop reading,
		1797	and as a client, it might cause problems, depending on your applciation.
1269		1798
1270	=cut	1799	=cut
1271		1800
1272	sub stop_read {	1801	sub stop_read {
1273	my ($self) = @_;	1802	my ($self) = @_;
1274		1803
1275	delete $self->{_rw} unless $self->{tls};	1804	delete $self->{_rw};
1276	}	1805	}
1277		1806
1278	sub start_read {	1807	sub start_read {
1279	my ($self) = @_;	1808	my ($self) = @_;
1280		1809
1281	unless ($self->{_rw} || $self->{_eof}) {	1810	unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1282	Scalar::Util::weaken $self;	1811	Scalar::Util::weaken $self;
1283		1812
1284	$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {	1813	$self->{_rw} = AE::io $self->{fh}, 0, sub {
1285	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});	1814	my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1286	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;	1815	my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1287		1816
1288	if ($len > 0) {	1817	if ($len > 0) {
1289	$self->{_activity} = AnyEvent->now;	1818	$self->{_activity} = $self->{_ractivity} = AE::now;
1290		1819
1291	if ($self->{tls}) {	1820	if ($self->{tls}) {
1292	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);	1821	Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1293		1822
1294	&_dotls ($self);	1823	&_dotls ($self);
1295	} else {	1824	} else {
1296	$self->_drain_rbuf unless $self->{_in_drain};	1825	$self->_drain_rbuf;
		1826	}
		1827
		1828	if ($len == $self->{read_size}) {
		1829	$self->{read_size} *= 2;
		1830	$self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
		1831	if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1297	}	1832	}
1298		1833
1299	} elsif (defined $len) {	1834	} elsif (defined $len) {
1300	delete $self->{_rw};	1835	delete $self->{_rw};
1301	$self->{_eof} = 1;	1836	$self->{_eof} = 1;
1302	$self->_drain_rbuf unless $self->{_in_drain};	1837	$self->_drain_rbuf;
1303		1838
1304	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {	1839	} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1305	return $self->_error ($!, 1);	1840	return $self->_error ($!, 1);
1306	}	1841	}
1307	});	1842	};
		1843	}
		1844	}
		1845
		1846	our $ERROR_SYSCALL;
		1847	our $ERROR_WANT_READ;
		1848
		1849	sub _tls_error {
		1850	my ($self, $err) = @_;
		1851
		1852	return $self->_error ($!, 1)
		1853	if $err == Net::SSLeay::ERROR_SYSCALL ();
		1854
		1855	my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
		1856
		1857	# reduce error string to look less scary
		1858	$err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
		1859
		1860	if ($self->{_on_starttls}) {
		1861	(delete $self->{_on_starttls})->($self, undef, $err);
		1862	&_freetls;
		1863	} else {
		1864	&_freetls;
		1865	$self->_error (Errno::EPROTO, 1, $err);
1308	}	1866	}
1309	}	1867	}
1310		1868
1311	# poll the write BIO and send the data if applicable	1869	# poll the write BIO and send the data if applicable
		1870	# also decode read data if possible
		1871	# this is basiclaly our TLS state machine
		1872	# more efficient implementations are possible with openssl,
		1873	# but not with the buggy and incomplete Net::SSLeay.
1312	sub _dotls {	1874	sub _dotls {
1313	my ($self) = @_;	1875	my ($self) = @_;
1314		1876
1315	my $tmp;	1877	my $tmp;
1316		1878
1317	if (length $self->{_tls_wbuf}) {	1879	if (length $self->{_tls_wbuf}) {
1318	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {	1880	while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1319	substr $self->{_tls_wbuf}, 0, $tmp, "";	1881	substr $self->{_tls_wbuf}, 0, $tmp, "";
1320	}	1882	}
		1883
		1884	$tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
		1885	return $self->_tls_error ($tmp)
		1886	if $tmp != $ERROR_WANT_READ
		1887	&& ($tmp != $ERROR_SYSCALL || $!);
1321	}	1888	}
1322		1889
1323	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {	1890	while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1324	unless (length $tmp) {	1891	unless (length $tmp) {
1325	# let's treat SSL-eof as we treat normal EOF	1892	$self->{_on_starttls}
1326	delete $self->{_rw};	1893	and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1327	$self->{_eof} = 1;
1328	&_freetls;	1894	&_freetls;
		1895
		1896	if ($self->{on_stoptls}) {
		1897	$self->{on_stoptls}($self);
		1898	return;
		1899	} else {
		1900	# let's treat SSL-eof as we treat normal EOF
		1901	delete $self->{_rw};
		1902	$self->{_eof} = 1;
		1903	}
1329	}	1904	}
1330		1905
1331	$self->{rbuf} .= $tmp;	1906	$self->{_tls_rbuf} .= $tmp;
1332	$self->_drain_rbuf unless $self->{_in_drain};	1907	$self->_drain_rbuf;
1333	$self->{tls} or return; # tls session might have gone away in callback	1908	$self->{tls} or return; # tls session might have gone away in callback
1334	}	1909	}
1335		1910
1336	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);	1911	$tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1337
1338	if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1339	if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1340	return $self->_error ($!, 1);	1912	return $self->_tls_error ($tmp)
1341	} elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {	1913	if $tmp != $ERROR_WANT_READ
1342	return $self->_error (&Errno::EIO, 1);	1914	&& ($tmp != $ERROR_SYSCALL || $!);
1343	}
1344
1345	# all other errors are fine for our purposes
1346	}
1347		1915
1348	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {	1916	while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1349	$self->{wbuf} .= $tmp;	1917	$self->{wbuf} .= $tmp;
1350	$self->_drain_wbuf;	1918	$self->_drain_wbuf;
		1919	$self->{tls} or return; # tls session might have gone away in callback
1351	}	1920	}
		1921
		1922	$self->{_on_starttls}
		1923	and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
		1924	and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1352	}	1925	}
1353		1926
1354	=item $handle->starttls ($tls[, $tls_ctx])	1927	=item $handle->starttls ($tls[, $tls_ctx])
1355		1928
1356	Instead of starting TLS negotiation immediately when the AnyEvent::Handle	1929	Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1357	object is created, you can also do that at a later time by calling	1930	object is created, you can also do that at a later time by calling
1358	C<starttls>.	1931	C<starttls>.
1359		1932
		1933	Starting TLS is currently an asynchronous operation - when you push some
		1934	write data and then call C<< ->starttls >> then TLS negotiation will start
		1935	immediately, after which the queued write data is then sent.
		1936
1360	The first argument is the same as the C<tls> constructor argument (either	1937	The first argument is the same as the C<tls> constructor argument (either
1361	C<"connect">, C<"accept"> or an existing Net::SSLeay object).	1938	C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1362		1939
1363	The second argument is the optional C<Net::SSLeay::CTX> object that is	1940	The second argument is the optional C<AnyEvent::TLS> object that is used
1364	used when AnyEvent::Handle has to create its own TLS connection object.	1941	when AnyEvent::Handle has to create its own TLS connection object, or
		1942	a hash reference with C<< key => value >> pairs that will be used to
		1943	construct a new context.
1365		1944
1366	The TLS connection object will end up in C<< $handle->{tls} >> after this	1945	The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1367	call and can be used or changed to your liking. Note that the handshake	1946	context in C<< $handle->{tls_ctx} >> after this call and can be used or
1368	might have already started when this function returns.	1947	changed to your liking. Note that the handshake might have already started
		1948	when this function returns.
1369		1949
1370	If it an error to start a TLS handshake more than once per	1950	Due to bugs in OpenSSL, it might or might not be possible to do multiple
1371	AnyEvent::Handle object (this is due to bugs in OpenSSL).	1951	handshakes on the same stream. It is best to not attempt to use the
		1952	stream after stopping TLS.
1372		1953
		1954	This method may invoke callbacks (and therefore the handle might be
		1955	destroyed after it returns).
		1956
1373	=cut	1957	=cut
		1958
		1959	our %TLS_CACHE; #TODO not yet documented, should we?
1374		1960
1375	sub starttls {	1961	sub starttls {
1376	my ($self, $ssl, $ctx) = @_;	1962	my ($self, $tls, $ctx) = @_;
		1963
		1964	Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
		1965	if $self->{tls};
		1966
		1967	$self->{tls} = $tls;
		1968	$self->{tls_ctx} = $ctx if @_ > 2;
		1969
		1970	return unless $self->{fh};
1377		1971
1378	require Net::SSLeay;	1972	require Net::SSLeay;
1379		1973
1380	Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"	1974	$ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1381	if $self->{tls};	1975	$ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
		1976
		1977	$tls = delete $self->{tls};
		1978	$ctx = $self->{tls_ctx};
		1979
		1980	local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
		1981
		1982	if ("HASH" eq ref $ctx) {
		1983	require AnyEvent::TLS;
		1984
		1985	if ($ctx->{cache}) {
		1986	my $key = $ctx+0;
		1987	$ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
		1988	} else {
		1989	$ctx = new AnyEvent::TLS %$ctx;
		1990	}
		1991	}
1382		1992
1383	if ($ssl eq "accept") {	1993	$self->{tls_ctx} = $ctx || TLS_CTX ();
1384	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());	1994	$self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1385	Net::SSLeay::set_accept_state ($ssl);
1386	} elsif ($ssl eq "connect") {
1387	$ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1388	Net::SSLeay::set_connect_state ($ssl);
1389	}
1390
1391	$self->{tls} = $ssl;
1392		1995
1393	# basically, this is deep magic (because SSL_read should have the same issues)	1996	# basically, this is deep magic (because SSL_read should have the same issues)
1394	# but the openssl maintainers basically said: "trust us, it just works".	1997	# but the openssl maintainers basically said: "trust us, it just works".
1395	# (unfortunately, we have to hardcode constants because the abysmally misdesigned	1998	# (unfortunately, we have to hardcode constants because the abysmally misdesigned
1396	# and mismaintained ssleay-module doesn't even offer them).	1999	# and mismaintained ssleay-module doesn't even offer them).
…		…
1400	#	2003	#
1401	# note that we do not try to keep the length constant between writes as we are required to do.	2004	# note that we do not try to keep the length constant between writes as we are required to do.
1402	# we assume that most (but not all) of this insanity only applies to non-blocking cases,	2005	# we assume that most (but not all) of this insanity only applies to non-blocking cases,
1403	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to	2006	# and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1404	# have identity issues in that area.	2007	# have identity issues in that area.
1405	Net::SSLeay::CTX_set_mode ($self->{tls},	2008	# Net::SSLeay::CTX_set_mode ($ssl,
1406	(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)	2009	# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1407	| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));	2010	# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
		2011	Net::SSLeay::CTX_set_mode ($tls, 1|2);
1408		2012
1409	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2013	$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1410	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());	2014	$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1411		2015
		2016	Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
		2017	$self->{rbuf} = "";
		2018
1412	Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});	2019	Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
		2020
		2021	$self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
		2022	if $self->{on_starttls};
1413		2023
1414	&_dotls; # need to trigger the initial handshake	2024	&_dotls; # need to trigger the initial handshake
1415	$self->start_read; # make sure we actually do read	2025	$self->start_read; # make sure we actually do read
1416	}	2026	}
1417		2027
1418	=item $handle->stoptls	2028	=item $handle->stoptls
1419		2029
1420	Shuts down the SSL connection - this makes a proper EOF handshake by	2030	Shuts down the SSL connection - this makes a proper EOF handshake by
1421	sending a close notify to the other side, but since OpenSSL doesn't	2031	sending a close notify to the other side, but since OpenSSL doesn't
1422	support non-blocking shut downs, it is not possible to re-use the stream	2032	support non-blocking shut downs, it is not guaranteed that you can re-use
1423	afterwards.	2033	the stream afterwards.
		2034
		2035	This method may invoke callbacks (and therefore the handle might be
		2036	destroyed after it returns).
1424		2037
1425	=cut	2038	=cut
1426		2039
1427	sub stoptls {	2040	sub stoptls {
1428	my ($self) = @_;	2041	my ($self) = @_;
1429		2042
1430	if ($self->{tls}) {	2043	if ($self->{tls} && $self->{fh}) {
1431	Net::SSLeay::shutdown ($self->{tls});	2044	Net::SSLeay::shutdown ($self->{tls});
1432		2045
1433	&_dotls;	2046	&_dotls;
1434		2047
1435	# we don't give a shit. no, we do, but we can't. no...	2048	# # we don't give a shit. no, we do, but we can't. no...#d#
1436	# we, we... have to use openssl :/	2049	# # we, we... have to use openssl :/#d#
1437	&_freetls;	2050	# &_freetls;#d#
1438	}	2051	}
1439	}	2052	}
1440		2053
1441	sub _freetls {	2054	sub _freetls {
1442	my ($self) = @_;	2055	my ($self) = @_;
1443		2056
1444	return unless $self->{tls};	2057	return unless $self->{tls};
1445		2058
1446	Net::SSLeay::free (delete $self->{tls});	2059	$self->{tls_ctx}->_put_session (delete $self->{tls})
		2060	if $self->{tls} > 0;
1447		2061
1448	delete @$self{qw(_rbio _wbio _tls_wbuf)};	2062	delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1449	}	2063	}
		2064
		2065	=item $handle->resettls
		2066
		2067	This rarely-used method simply resets and TLS state on the handle, usually
		2068	causing data loss.
		2069
		2070	One case where it may be useful is when you want to skip over the data in
		2071	the stream but you are not interested in interpreting it, so data loss is
		2072	no concern.
		2073
		2074	=cut
		2075
		2076	*resettls = \&_freetls;
1450		2077
1451	sub DESTROY {	2078	sub DESTROY {
1452	my $self = shift;	2079	my ($self) = @_;
1453		2080
1454	&_freetls;	2081	&_freetls;
1455		2082
1456	my $linger = exists $self->{linger} ? $self->{linger} : 3600;	2083	my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1457		2084
1458	if ($linger && length $self->{wbuf}) {	2085	if ($linger && length $self->{wbuf} && $self->{fh}) {
1459	my $fh = delete $self->{fh};	2086	my $fh = delete $self->{fh};
1460	my $wbuf = delete $self->{wbuf};	2087	my $wbuf = delete $self->{wbuf};
1461		2088
1462	my @linger;	2089	my @linger;
1463		2090
1464	push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {	2091	push @linger, AE::io $fh, 1, sub {
1465	my $len = syswrite $fh, $wbuf, length $wbuf;	2092	my $len = syswrite $fh, $wbuf, length $wbuf;
1466		2093
1467	if ($len > 0) {	2094	if ($len > 0) {
1468	substr $wbuf, 0, $len, "";	2095	substr $wbuf, 0, $len, "";
1469	} else {	2096	} elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1470	@linger = (); # end	2097	@linger = (); # end
1471	}	2098	}
1472	});	2099	};
1473	push @linger, AnyEvent->timer (after => $linger, cb => sub {	2100	push @linger, AE::timer $linger, 0, sub {
1474	@linger = ();	2101	@linger = ();
1475	});	2102	};
1476	}	2103	}
1477	}	2104	}
1478		2105
1479	=item $handle->destroy	2106	=item $handle->destroy
1480		2107
1481	Shuts down the handle object as much as possible - this call ensures that	2108	Shuts down the handle object as much as possible - this call ensures that
1482	no further callbacks will be invoked and resources will be freed as much	2109	no further callbacks will be invoked and as many resources as possible
1483	as possible. You must not call any methods on the object afterwards.	2110	will be freed. Any method you will call on the handle object after
		2111	destroying it in this way will be silently ignored (and it will return the
		2112	empty list).
1484		2113
1485	Normally, you can just "forget" any references to an AnyEvent::Handle	2114	Normally, you can just "forget" any references to an AnyEvent::Handle
1486	object and it will simply shut down. This works in fatal error and EOF	2115	object and it will simply shut down. This works in fatal error and EOF
1487	callbacks, as well as code outside. It does I<NOT> work in a read or write	2116	callbacks, as well as code outside. It does I<NOT> work in a read or write
1488	callback, so when you want to destroy the AnyEvent::Handle object from	2117	callback, so when you want to destroy the AnyEvent::Handle object from
1489	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in	2118	within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1490	that case.	2119	that case.
1491		2120
		2121	Destroying the handle object in this way has the advantage that callbacks
		2122	will be removed as well, so if those are the only reference holders (as
		2123	is common), then one doesn't need to do anything special to break any
		2124	reference cycles.
		2125
1492	The handle might still linger in the background and write out remaining	2126	The handle might still linger in the background and write out remaining
1493	data, as specified by the C<linger> option, however.	2127	data, as specified by the C<linger> option, however.
1494		2128
1495	=cut	2129	=cut
1496		2130
1497	sub destroy {	2131	sub destroy {
1498	my ($self) = @_;	2132	my ($self) = @_;
1499		2133
1500	$self->DESTROY;	2134	$self->DESTROY;
1501	%$self = ();	2135	%$self = ();
		2136	bless $self, "AnyEvent::Handle::destroyed";
1502	}	2137	}
		2138
		2139	sub AnyEvent::Handle::destroyed::AUTOLOAD {
		2140	#nop
		2141	}
		2142
		2143	=item $handle->destroyed
		2144
		2145	Returns false as long as the handle hasn't been destroyed by a call to C<<
		2146	->destroy >>, true otherwise.
		2147
		2148	Can be useful to decide whether the handle is still valid after some
		2149	callback possibly destroyed the handle. For example, C<< ->push_write >>,
		2150	C<< ->starttls >> and other methods can call user callbacks, which in turn
		2151	can destroy the handle, so work can be avoided by checking sometimes:
		2152
		2153	$hdl->starttls ("accept");
		2154	return if $hdl->destroyed;
		2155	$hdl->push_write (...
		2156
		2157	Note that the call to C<push_write> will silently be ignored if the handle
		2158	has been destroyed, so often you can just ignore the possibility of the
		2159	handle being destroyed.
		2160
		2161	=cut
		2162
		2163	sub destroyed { 0 }
		2164	sub AnyEvent::Handle::destroyed::destroyed { 1 }
1503		2165
1504	=item AnyEvent::Handle::TLS_CTX	2166	=item AnyEvent::Handle::TLS_CTX
1505		2167
1506	This function creates and returns the Net::SSLeay::CTX object used by	2168	This function creates and returns the AnyEvent::TLS object used by default
1507	default for TLS mode.	2169	for TLS mode.
1508		2170
1509	The context is created like this:	2171	The context is created by calling L<AnyEvent::TLS> without any arguments.
1510
1511	Net::SSLeay::load_error_strings;
1512	Net::SSLeay::SSLeay_add_ssl_algorithms;
1513	Net::SSLeay::randomize;
1514
1515	my $CTX = Net::SSLeay::CTX_new;
1516
1517	Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1518		2172
1519	=cut	2173	=cut
1520		2174
1521	our $TLS_CTX;	2175	our $TLS_CTX;
1522		2176
1523	sub TLS_CTX() {	2177	sub TLS_CTX() {
1524	$TLS_CTX || do {	2178	$TLS_CTX ||= do {
1525	require Net::SSLeay;	2179	require AnyEvent::TLS;
1526		2180
1527	Net::SSLeay::load_error_strings ();	2181	new AnyEvent::TLS
1528	Net::SSLeay::SSLeay_add_ssl_algorithms ();
1529	Net::SSLeay::randomize ();
1530
1531	$TLS_CTX = Net::SSLeay::CTX_new ();
1532
1533	Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1534
1535	$TLS_CTX
1536	}	2182	}
1537	}	2183	}
1538		2184
1539	=back	2185	=back
1540		2186
…		…
1551		2197
1552	It is only safe to "forget" the reference inside EOF or error callbacks,	2198	It is only safe to "forget" the reference inside EOF or error callbacks,
1553	from within all other callbacks, you need to explicitly call the C<<	2199	from within all other callbacks, you need to explicitly call the C<<
1554	->destroy >> method.	2200	->destroy >> method.
1555		2201
		2202	=item Why is my C<on_eof> callback never called?
		2203
		2204	Probably because your C<on_error> callback is being called instead: When
		2205	you have outstanding requests in your read queue, then an EOF is
		2206	considered an error as you clearly expected some data.
		2207
		2208	To avoid this, make sure you have an empty read queue whenever your handle
		2209	is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
		2210	an C<on_read> handler that simply pushes the first read requests in the
		2211	queue.
		2212
		2213	See also the next question, which explains this in a bit more detail.
		2214
		2215	=item How can I serve requests in a loop?
		2216
		2217	Most protocols consist of some setup phase (authentication for example)
		2218	followed by a request handling phase, where the server waits for requests
		2219	and handles them, in a loop.
		2220
		2221	There are two important variants: The first (traditional, better) variant
		2222	handles requests until the server gets some QUIT command, causing it to
		2223	close the connection first (highly desirable for a busy TCP server). A
		2224	client dropping the connection is an error, which means this variant can
		2225	detect an unexpected detection close.
		2226
		2227	To handle this case, always make sure you have a on-empty read queue, by
		2228	pushing the "read request start" handler on it:
		2229
		2230	# we assume a request starts with a single line
		2231	my @start_request; @start_request = (line => sub {
		2232	my ($hdl, $line) = @_;
		2233
		2234	... handle request
		2235
		2236	# push next request read, possibly from a nested callback
		2237	$hdl->push_read (@start_request);
		2238	});
		2239
		2240	# auth done, now go into request handling loop
		2241	# now push the first @start_request
		2242	$hdl->push_read (@start_request);
		2243
		2244	By always having an outstanding C<push_read>, the handle always expects
		2245	some data and raises the C<EPIPE> error when the connction is dropped
		2246	unexpectedly.
		2247
		2248	The second variant is a protocol where the client can drop the connection
		2249	at any time. For TCP, this means that the server machine may run out of
		2250	sockets easier, and in general, it means you cnanot distinguish a protocl
		2251	failure/client crash from a normal connection close. Nevertheless, these
		2252	kinds of protocols are common (and sometimes even the best solution to the
		2253	problem).
		2254
		2255	Having an outstanding read request at all times is possible if you ignore
		2256	C<EPIPE> errors, but this doesn't help with when the client drops the
		2257	connection during a request, which would still be an error.
		2258
		2259	A better solution is to push the initial request read in an C<on_read>
		2260	callback. This avoids an error, as when the server doesn't expect data
		2261	(i.e. is idly waiting for the next request, an EOF will not raise an
		2262	error, but simply result in an C<on_eof> callback. It is also a bit slower
		2263	and simpler:
		2264
		2265	# auth done, now go into request handling loop
		2266	$hdl->on_read (sub {
		2267	my ($hdl) = @_;
		2268
		2269	# called each time we receive data but the read queue is empty
		2270	# simply start read the request
		2271
		2272	$hdl->push_read (line => sub {
		2273	my ($hdl, $line) = @_;
		2274
		2275	... handle request
		2276
		2277	# do nothing special when the request has been handled, just
		2278	# let the request queue go empty.
		2279	});
		2280	});
		2281
1556	=item I get different callback invocations in TLS mode/Why can't I pause	2282	=item I get different callback invocations in TLS mode/Why can't I pause
1557	reading?	2283	reading?
1558		2284
1559	Unlike, say, TCP, TLS connections do not consist of two independent	2285	Unlike, say, TCP, TLS connections do not consist of two independent
1560	communication channels, one for each direction. Or put differently. The	2286	communication channels, one for each direction. Or put differently, the
1561	read and write directions are not independent of each other: you cannot	2287	read and write directions are not independent of each other: you cannot
1562	write data unless you are also prepared to read, and vice versa.	2288	write data unless you are also prepared to read, and vice versa.
1563		2289
1564	This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>	2290	This means that, in TLS mode, you might get C<on_error> or C<on_eof>
1565	callback invocations when you are not expecting any read data - the reason	2291	callback invocations when you are not expecting any read data - the reason
1566	is that AnyEvent::Handle always reads in TLS mode.	2292	is that AnyEvent::Handle always reads in TLS mode.
1567		2293
1568	During the connection, you have to make sure that you always have a	2294	During the connection, you have to make sure that you always have a
1569	non-empty read-queue, or an C<on_read> watcher. At the end of the	2295	non-empty read-queue, or an C<on_read> watcher. At the end of the
…		…
1579		2305
1580	$handle->on_read (sub { });	2306	$handle->on_read (sub { });
1581	$handle->on_eof (undef);	2307	$handle->on_eof (undef);
1582	$handle->on_error (sub {	2308	$handle->on_error (sub {
1583	my $data = delete $_[0]{rbuf};	2309	my $data = delete $_[0]{rbuf};
1584	undef $handle;
1585	});	2310	});
		2311
		2312	Note that this example removes the C<rbuf> member from the handle object,
		2313	which is not normally allowed by the API. It is expressly permitted in
		2314	this case only, as the handle object needs to be destroyed afterwards.
1586		2315
1587	The reason to use C<on_error> is that TCP connections, due to latencies	2316	The reason to use C<on_error> is that TCP connections, due to latencies
1588	and packets loss, might get closed quite violently with an error, when in	2317	and packets loss, might get closed quite violently with an error, when in
1589	fact, all data has been received.	2318	fact all data has been received.
1590		2319
1591	It is usually better to use acknowledgements when transferring data,	2320	It is usually better to use acknowledgements when transferring data,
1592	to make sure the other side hasn't just died and you got the data	2321	to make sure the other side hasn't just died and you got the data
1593	intact. This is also one reason why so many internet protocols have an	2322	intact. This is also one reason why so many internet protocols have an
1594	explicit QUIT command.	2323	explicit QUIT command.
…		…
1601	C<low_water_mark> this will be called precisely when all data has been	2330	C<low_water_mark> this will be called precisely when all data has been
1602	written to the socket:	2331	written to the socket:
1603		2332
1604	$handle->push_write (...);	2333	$handle->push_write (...);
1605	$handle->on_drain (sub {	2334	$handle->on_drain (sub {
1606	warn "all data submitted to the kernel\n";	2335	AE::log debug => "all data submitted to the kernel\n";
1607	undef $handle;	2336	undef $handle;
1608	});	2337	});
		2338
		2339	If you just want to queue some data and then signal EOF to the other side,
		2340	consider using C<< ->push_shutdown >> instead.
		2341
		2342	=item I want to contact a TLS/SSL server, I don't care about security.
		2343
		2344	If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
		2345	connect to it and then create the AnyEvent::Handle with the C<tls>
		2346	parameter:
		2347
		2348	tcp_connect $host, $port, sub {
		2349	my ($fh) = @_;
		2350
		2351	my $handle = new AnyEvent::Handle
		2352	fh => $fh,
		2353	tls => "connect",
		2354	on_error => sub { ... };
		2355
		2356	$handle->push_write (...);
		2357	};
		2358
		2359	=item I want to contact a TLS/SSL server, I do care about security.
		2360
		2361	Then you should additionally enable certificate verification, including
		2362	peername verification, if the protocol you use supports it (see
		2363	L<AnyEvent::TLS>, C<verify_peername>).
		2364
		2365	E.g. for HTTPS:
		2366
		2367	tcp_connect $host, $port, sub {
		2368	my ($fh) = @_;
		2369
		2370	my $handle = new AnyEvent::Handle
		2371	fh => $fh,
		2372	peername => $host,
		2373	tls => "connect",
		2374	tls_ctx => { verify => 1, verify_peername => "https" },
		2375	...
		2376
		2377	Note that you must specify the hostname you connected to (or whatever
		2378	"peername" the protocol needs) as the C<peername> argument, otherwise no
		2379	peername verification will be done.
		2380
		2381	The above will use the system-dependent default set of trusted CA
		2382	certificates. If you want to check against a specific CA, add the
		2383	C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
		2384
		2385	tls_ctx => {
		2386	verify => 1,
		2387	verify_peername => "https",
		2388	ca_file => "my-ca-cert.pem",
		2389	},
		2390
		2391	=item I want to create a TLS/SSL server, how do I do that?
		2392
		2393	Well, you first need to get a server certificate and key. You have
		2394	three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
		2395	self-signed certificate (cheap. check the search engine of your choice,
		2396	there are many tutorials on the net) or c) make your own CA (tinyca2 is a
		2397	nice program for that purpose).
		2398
		2399	Then create a file with your private key (in PEM format, see
		2400	L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
		2401	file should then look like this:
		2402
		2403	-----BEGIN RSA PRIVATE KEY-----
		2404	...header data
		2405	... lots of base64'y-stuff
		2406	-----END RSA PRIVATE KEY-----
		2407
		2408	-----BEGIN CERTIFICATE-----
		2409	... lots of base64'y-stuff
		2410	-----END CERTIFICATE-----
		2411
		2412	The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
		2413	specify this file as C<cert_file>:
		2414
		2415	tcp_server undef, $port, sub {
		2416	my ($fh) = @_;
		2417
		2418	my $handle = new AnyEvent::Handle
		2419	fh => $fh,
		2420	tls => "accept",
		2421	tls_ctx => { cert_file => "my-server-keycert.pem" },
		2422	...
		2423
		2424	When you have intermediate CA certificates that your clients might not
		2425	know about, just append them to the C<cert_file>.
1609		2426
1610	=back	2427	=back
1611		2428
1612		2429
1613	=head1 SUBCLASSING AnyEvent::Handle	2430	=head1 SUBCLASSING AnyEvent::Handle
…		…
1633		2450
1634	=item * all members not documented here and not prefixed with an underscore	2451	=item * all members not documented here and not prefixed with an underscore
1635	are free to use in subclasses.	2452	are free to use in subclasses.
1636		2453
1637	Of course, new versions of AnyEvent::Handle may introduce more "public"	2454	Of course, new versions of AnyEvent::Handle may introduce more "public"
1638	member variables, but thats just life, at least it is documented.	2455	member variables, but that's just life. At least it is documented.
1639		2456
1640	=back	2457	=back
1641		2458
1642	=head1 AUTHOR	2459	=head1 AUTHOR
1643		2460

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines