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Revision 1.152 by root, Fri Jul 17 14:57:03 2009 UTC vs.
Revision 1.236 by root, Sat May 12 23:14:29 2012 UTC

1package AnyEvent::Handle;
2
3no warnings;
4use strict qw(subs vars);
5
6use AnyEvent ();
7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util ();
9use Carp ();
10use Fcntl ();
11use Errno qw(EAGAIN EINTR);
12
13=head1 NAME 1=head1 NAME
14 2
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
16
17=cut
18
19our $VERSION = 4.83;
20 4
21=head1 SYNOPSIS 5=head1 SYNOPSIS
22 6
23 use AnyEvent; 7 use AnyEvent;
24 use AnyEvent::Handle; 8 use AnyEvent::Handle;
27 11
28 my $hdl; $hdl = new AnyEvent::Handle 12 my $hdl; $hdl = new AnyEvent::Handle
29 fh => \*STDIN, 13 fh => \*STDIN,
30 on_error => sub { 14 on_error => sub {
31 my ($hdl, $fatal, $msg) = @_; 15 my ($hdl, $fatal, $msg) = @_;
32 warn "got error $msg\n"; 16 AE::log error => $msg;
33 $hdl->destroy; 17 $hdl->destroy;
34 $cv->send; 18 $cv->send;
35 ); 19 };
36 20
37 # send some request line 21 # send some request line
38 $hdl->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
39 23
40 # read the response line 24 # read the response line
41 $hdl->push_read (line => sub { 25 $hdl->push_read (line => sub {
42 my ($hdl, $line) = @_; 26 my ($hdl, $line) = @_;
43 warn "got line <$line>\n"; 27 say "got line <$line>";
44 $cv->send; 28 $cv->send;
45 }); 29 });
46 30
47 $cv->recv; 31 $cv->recv;
48 32
49=head1 DESCRIPTION 33=head1 DESCRIPTION
50 34
51This module is a helper module to make it easier to do event-based I/O on 35This is a helper module to make it easier to do event-based I/O on
52filehandles. For utility functions for doing non-blocking connects and accepts 36stream-based filehandles (sockets, pipes, and other stream things).
53on sockets see L<AnyEvent::Util>.
54 37
55The L<AnyEvent::Intro> tutorial contains some well-documented 38The L<AnyEvent::Intro> tutorial contains some well-documented
56AnyEvent::Handle examples. 39AnyEvent::Handle examples.
57 40
58In the following, when the documentation refers to of "bytes" then this 41In the following, where the documentation refers to "bytes", it means
59means characters. As sysread and syswrite are used for all I/O, their 42characters. As sysread and syswrite are used for all I/O, their
60treatment of characters applies to this module as well. 43treatment of characters applies to this module as well.
44
45At the very minimum, you should specify C<fh> or C<connect>, and the
46C<on_error> callback.
61 47
62All callbacks will be invoked with the handle object as their first 48All callbacks will be invoked with the handle object as their first
63argument. 49argument.
64 50
51=cut
52
53package AnyEvent::Handle;
54
55use Scalar::Util ();
56use List::Util ();
57use Carp ();
58use Errno qw(EAGAIN EINTR);
59
60use AnyEvent (); BEGIN { AnyEvent::common_sense }
61use AnyEvent::Util qw(WSAEWOULDBLOCK);
62
63our $VERSION = $AnyEvent::VERSION;
64
65sub _load_func($) {
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
80sub MAX_READ_SIZE() { 131072 }
81
65=head1 METHODS 82=head1 METHODS
66 83
67=over 4 84=over 4
68 85
69=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value... 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
70 87
71The constructor supports these arguments (all as C<< key => value >> pairs). 88The constructor supports these arguments (all as C<< key => value >> pairs).
72 89
73=over 4 90=over 4
74 91
75=item fh => $filehandle [MANDATORY] 92=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
76 93
77The filehandle this L<AnyEvent::Handle> object will operate on. 94The filehandle this L<AnyEvent::Handle> object will operate on.
78
79NOTE: The filehandle will be set to non-blocking mode (using 95NOTE: The filehandle will be set to non-blocking mode (using
80C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in 96C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
81that mode. 97that mode.
98
99=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
100
101Try to connect to the specified host and service (port), using
102C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
103default C<peername>.
104
105You have to specify either this parameter, or C<fh>, above.
106
107It is possible to push requests on the read and write queues, and modify
108properties of the stream, even while AnyEvent::Handle is connecting.
109
110When this parameter is specified, then the C<on_prepare>,
111C<on_connect_error> and C<on_connect> callbacks will be called under the
112appropriate circumstances:
113
114=over 4
115
116=item on_prepare => $cb->($handle)
117
118This (rarely used) callback is called before a new connection is
119attempted, but after the file handle has been created (you can access that
120file handle via C<< $handle->{fh} >>). It could be used to prepare the
121file handle with parameters required for the actual connect (as opposed to
122settings that can be changed when the connection is already established).
123
124The return value of this callback should be the connect timeout value in
125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
126default timeout is to be used).
127
128=item on_connect => $cb->($handle, $host, $port, $retry->())
129
130This callback is called when a connection has been successfully established.
131
132The peer's numeric host and port (the socket peername) are passed as
133parameters, together with a retry callback. At the time it is called the
134read and write queues, EOF status, TLS status and similar properties of
135the handle will have been reset.
136
137It is not allowed to use the read or write queues while the handle object
138is connecting.
139
140If, for some reason, the handle is not acceptable, calling C<$retry> will
141continue with the next connection target (in case of multi-homed hosts or
142SRV records there can be multiple connection endpoints). The C<$retry>
143callback can be invoked after the connect callback returns, i.e. one can
144start a handshake and then decide to retry with the next host if the
145handshake fails.
146
147In most cases, you should ignore the C<$retry> parameter.
148
149=item on_connect_error => $cb->($handle, $message)
150
151This callback is called when the connection could not be
152established. C<$!> will contain the relevant error code, and C<$message> a
153message describing it (usually the same as C<"$!">).
154
155If this callback isn't specified, then C<on_error> will be called with a
156fatal error instead.
157
158=back
159
160=item on_error => $cb->($handle, $fatal, $message)
161
162This is the error callback, which is called when, well, some error
163occured, such as not being able to resolve the hostname, failure to
164connect, or a read error.
165
166Some errors are fatal (which is indicated by C<$fatal> being true). On
167fatal errors the handle object will be destroyed (by a call to C<< ->
168destroy >>) after invoking the error callback (which means you are free to
169examine the handle object). Examples of fatal errors are an EOF condition
170with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
171cases where the other side can close the connection at will, it is
172often easiest to not report C<EPIPE> errors in this callback.
173
174AnyEvent::Handle tries to find an appropriate error code for you to check
175against, but in some cases (TLS errors), this does not work well.
176
177If you report the error to the user, it is recommended to always output
178the C<$message> argument in human-readable error messages (you don't need
179to report C<"$!"> if you report C<$message>).
180
181If you want to react programmatically to the error, then looking at C<$!>
182and comparing it against some of the documented C<Errno> values is usually
183better than looking at the C<$message>.
184
185Non-fatal errors can be retried by returning, but it is recommended
186to simply ignore this parameter and instead abondon the handle object
187when this callback is invoked. Examples of non-fatal errors are timeouts
188C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
189
190On entry to the callback, the value of C<$!> contains the operating
191system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
192C<EPROTO>).
193
194While not mandatory, it is I<highly> recommended to set this callback, as
195you will not be notified of errors otherwise. The default just calls
196C<croak>.
197
198=item on_read => $cb->($handle)
199
200This sets the default read callback, which is called when data arrives
201and no read request is in the queue (unlike read queue callbacks, this
202callback will only be called when at least one octet of data is in the
203read buffer).
204
205To access (and remove data from) the read buffer, use the C<< ->rbuf >>
206method or access the C<< $handle->{rbuf} >> member directly. Note that you
207must not enlarge or modify the read buffer, you can only remove data at
208the beginning from it.
209
210You can also call C<< ->push_read (...) >> or any other function that
211modifies the read queue. Or do both. Or ...
212
213When an EOF condition is detected, AnyEvent::Handle will first try to
214feed all the remaining data to the queued callbacks and C<on_read> before
215calling the C<on_eof> callback. If no progress can be made, then a fatal
216error will be raised (with C<$!> set to C<EPIPE>).
217
218Note that, unlike requests in the read queue, an C<on_read> callback
219doesn't mean you I<require> some data: if there is an EOF and there
220are outstanding read requests then an error will be flagged. With an
221C<on_read> callback, the C<on_eof> callback will be invoked.
82 222
83=item on_eof => $cb->($handle) 223=item on_eof => $cb->($handle)
84 224
85Set the callback to be called when an end-of-file condition is detected, 225Set the callback to be called when an end-of-file condition is detected,
86i.e. in the case of a socket, when the other side has closed the 226i.e. in the case of a socket, when the other side has closed the
94down. 234down.
95 235
96If an EOF condition has been detected but no C<on_eof> callback has been 236If an EOF condition has been detected but no C<on_eof> callback has been
97set, then a fatal error will be raised with C<$!> set to <0>. 237set, then a fatal error will be raised with C<$!> set to <0>.
98 238
99=item on_error => $cb->($handle, $fatal, $message)
100
101This is the error callback, which is called when, well, some error
102occured, such as not being able to resolve the hostname, failure to
103connect or a read error.
104
105Some errors are fatal (which is indicated by C<$fatal> being true). On
106fatal errors the handle object will be destroyed (by a call to C<< ->
107destroy >>) after invoking the error callback (which means you are free to
108examine the handle object). Examples of fatal errors are an EOF condition
109with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors.
110
111AnyEvent::Handle tries to find an appropriate error code for you to check
112against, but in some cases (TLS errors), this does not work well. It is
113recommended to always output the C<$message> argument in human-readable
114error messages (it's usually the same as C<"$!">).
115
116Non-fatal errors can be retried by simply returning, but it is recommended
117to simply ignore this parameter and instead abondon the handle object
118when this callback is invoked. Examples of non-fatal errors are timeouts
119C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
120
121On callback entrance, the value of C<$!> contains the operating system
122error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
123C<EPROTO>).
124
125While not mandatory, it is I<highly> recommended to set this callback, as
126you will not be notified of errors otherwise. The default simply calls
127C<croak>.
128
129=item on_read => $cb->($handle)
130
131This sets the default read callback, which is called when data arrives
132and no read request is in the queue (unlike read queue callbacks, this
133callback will only be called when at least one octet of data is in the
134read buffer).
135
136To access (and remove data from) the read buffer, use the C<< ->rbuf >>
137method or access the C<< $handle->{rbuf} >> member directly. Note that you
138must not enlarge or modify the read buffer, you can only remove data at
139the beginning from it.
140
141When an EOF condition is detected then AnyEvent::Handle will first try to
142feed all the remaining data to the queued callbacks and C<on_read> before
143calling the C<on_eof> callback. If no progress can be made, then a fatal
144error will be raised (with C<$!> set to C<EPIPE>).
145
146Note that, unlike requests in the read queue, an C<on_read> callback
147doesn't mean you I<require> some data: if there is an EOF and there
148are outstanding read requests then an error will be flagged. With an
149C<on_read> callback, the C<on_eof> callback will be invoked.
150
151=item on_drain => $cb->($handle) 239=item on_drain => $cb->($handle)
152 240
153This sets the callback that is called when the write buffer becomes empty 241This sets the callback that is called once when the write buffer becomes
154(or when the callback is set and the buffer is empty already). 242empty (and immediately when the handle object is created).
155 243
156To append to the write buffer, use the C<< ->push_write >> method. 244To append to the write buffer, use the C<< ->push_write >> method.
157 245
158This callback is useful when you don't want to put all of your write data 246This callback is useful when you don't want to put all of your write data
159into the queue at once, for example, when you want to write the contents 247into the queue at once, for example, when you want to write the contents
161memory and push it into the queue, but instead only read more data from 249memory and push it into the queue, but instead only read more data from
162the file when the write queue becomes empty. 250the file when the write queue becomes empty.
163 251
164=item timeout => $fractional_seconds 252=item timeout => $fractional_seconds
165 253
254=item rtimeout => $fractional_seconds
255
256=item wtimeout => $fractional_seconds
257
166If non-zero, then this enables an "inactivity" timeout: whenever this many 258If non-zero, then these enables an "inactivity" timeout: whenever this
167seconds pass without a successful read or write on the underlying file 259many seconds pass without a successful read or write on the underlying
168handle, the C<on_timeout> callback will be invoked (and if that one is 260file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
169missing, a non-fatal C<ETIMEDOUT> error will be raised). 261will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
262error will be raised).
170 263
264There are three variants of the timeouts that work independently of each
265other, for both read and write (triggered when nothing was read I<OR>
266written), just read (triggered when nothing was read), and just write:
267C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
268C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
269C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
270
171Note that timeout processing is also active when you currently do not have 271Note that timeout processing is active even when you do not have any
172any outstanding read or write requests: If you plan to keep the connection 272outstanding read or write requests: If you plan to keep the connection
173idle then you should disable the timout temporarily or ignore the timeout 273idle then you should disable the timeout temporarily or ignore the
174in the C<on_timeout> callback, in which case AnyEvent::Handle will simply 274timeout in the corresponding C<on_timeout> callback, in which case
175restart the timeout. 275AnyEvent::Handle will simply restart the timeout.
176 276
177Zero (the default) disables this timeout. 277Zero (the default) disables the corresponding timeout.
178 278
179=item on_timeout => $cb->($handle) 279=item on_timeout => $cb->($handle)
280
281=item on_rtimeout => $cb->($handle)
282
283=item on_wtimeout => $cb->($handle)
180 284
181Called whenever the inactivity timeout passes. If you return from this 285Called whenever the inactivity timeout passes. If you return from this
182callback, then the timeout will be reset as if some activity had happened, 286callback, then the timeout will be reset as if some activity had happened,
183so this condition is not fatal in any way. 287so this condition is not fatal in any way.
184 288
192be configured to accept only so-and-so much data that it cannot act on 296be configured to accept only so-and-so much data that it cannot act on
193(for example, when expecting a line, an attacker could send an unlimited 297(for example, when expecting a line, an attacker could send an unlimited
194amount of data without a callback ever being called as long as the line 298amount of data without a callback ever being called as long as the line
195isn't finished). 299isn't finished).
196 300
301=item wbuf_max => <bytes>
302
303If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
304when the write buffer ever (strictly) exceeds this size. This is useful to
305avoid some forms of denial-of-service attacks.
306
307Although the units of this parameter is bytes, this is the I<raw> number
308of bytes not yet accepted by the kernel. This can make a difference when
309you e.g. use TLS, as TLS typically makes your write data larger (but it
310can also make it smaller due to compression).
311
312As an example of when this limit is useful, take a chat server that sends
313chat messages to a client. If the client does not read those in a timely
314manner then the send buffer in the server would grow unbounded.
315
197=item autocork => <boolean> 316=item autocork => <boolean>
198 317
199When disabled (the default), then C<push_write> will try to immediately 318When disabled (the default), C<push_write> will try to immediately
200write the data to the handle, if possible. This avoids having to register 319write the data to the handle if possible. This avoids having to register
201a write watcher and wait for the next event loop iteration, but can 320a write watcher and wait for the next event loop iteration, but can
202be inefficient if you write multiple small chunks (on the wire, this 321be inefficient if you write multiple small chunks (on the wire, this
203disadvantage is usually avoided by your kernel's nagle algorithm, see 322disadvantage is usually avoided by your kernel's nagle algorithm, see
204C<no_delay>, but this option can save costly syscalls). 323C<no_delay>, but this option can save costly syscalls).
205 324
206When enabled, then writes will always be queued till the next event loop 325When enabled, writes will always be queued till the next event loop
207iteration. This is efficient when you do many small writes per iteration, 326iteration. This is efficient when you do many small writes per iteration,
208but less efficient when you do a single write only per iteration (or when 327but less efficient when you do a single write only per iteration (or when
209the write buffer often is full). It also increases write latency. 328the write buffer often is full). It also increases write latency.
210 329
211=item no_delay => <boolean> 330=item no_delay => <boolean>
215the Nagle algorithm, and usually it is beneficial. 334the Nagle algorithm, and usually it is beneficial.
216 335
217In some situations you want as low a delay as possible, which can be 336In some situations you want as low a delay as possible, which can be
218accomplishd by setting this option to a true value. 337accomplishd by setting this option to a true value.
219 338
220The default is your opertaing system's default behaviour (most likely 339The default is your operating system's default behaviour (most likely
221enabled), this option explicitly enables or disables it, if possible. 340enabled). This option explicitly enables or disables it, if possible.
341
342=item keepalive => <boolean>
343
344Enables (default disable) the SO_KEEPALIVE option on the stream socket:
345normally, TCP connections have no time-out once established, so TCP
346connections, once established, can stay alive forever even when the other
347side has long gone. TCP keepalives are a cheap way to take down long-lived
348TCP connections when the other side becomes unreachable. While the default
349is OS-dependent, TCP keepalives usually kick in after around two hours,
350and, if the other side doesn't reply, take down the TCP connection some 10
351to 15 minutes later.
352
353It is harmless to specify this option for file handles that do not support
354keepalives, and enabling it on connections that are potentially long-lived
355is usually a good idea.
356
357=item oobinline => <boolean>
358
359BSD majorly fucked up the implementation of TCP urgent data. The result
360is that almost no OS implements TCP according to the specs, and every OS
361implements it slightly differently.
362
363If you want to handle TCP urgent data, then setting this flag (the default
364is enabled) gives you the most portable way of getting urgent data, by
365putting it into the stream.
366
367Since BSD emulation of OOB data on top of TCP's urgent data can have
368security implications, AnyEvent::Handle sets this flag automatically
369unless explicitly specified. Note that setting this flag after
370establishing a connection I<may> be a bit too late (data loss could
371already have occured on BSD systems), but at least it will protect you
372from most attacks.
222 373
223=item read_size => <bytes> 374=item read_size => <bytes>
224 375
225The default read block size (the amount of bytes this module will 376The initial read block size, the number of bytes this module will try
226try to read during each loop iteration, which affects memory 377to read during each loop iteration. Each handle object will consume
227requirements). Default: C<8192>. 378at least this amount of memory for the read buffer as well, so when
379handling many connections watch out for memory requirements). See also
380C<max_read_size>. Default: C<2048>.
381
382=item max_read_size => <bytes>
383
384The maximum read buffer size used by the dynamic adjustment
385algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
386one go it will double C<read_size> up to the maximum given by this
387option. Default: C<131072> or C<read_size>, whichever is higher.
228 388
229=item low_water_mark => <bytes> 389=item low_water_mark => <bytes>
230 390
231Sets the amount of bytes (default: C<0>) that make up an "empty" write 391Sets the number of bytes (default: C<0>) that make up an "empty" write
232buffer: If the write reaches this size or gets even samller it is 392buffer: If the buffer reaches this size or gets even samller it is
233considered empty. 393considered empty.
234 394
235Sometimes it can be beneficial (for performance reasons) to add data to 395Sometimes it can be beneficial (for performance reasons) to add data to
236the write buffer before it is fully drained, but this is a rare case, as 396the write buffer before it is fully drained, but this is a rare case, as
237the operating system kernel usually buffers data as well, so the default 397the operating system kernel usually buffers data as well, so the default
238is good in almost all cases. 398is good in almost all cases.
239 399
240=item linger => <seconds> 400=item linger => <seconds>
241 401
242If non-zero (default: C<3600>), then the destructor of the 402If this is non-zero (default: C<3600>), the destructor of the
243AnyEvent::Handle object will check whether there is still outstanding 403AnyEvent::Handle object will check whether there is still outstanding
244write data and will install a watcher that will write this data to the 404write data and will install a watcher that will write this data to the
245socket. No errors will be reported (this mostly matches how the operating 405socket. No errors will be reported (this mostly matches how the operating
246system treats outstanding data at socket close time). 406system treats outstanding data at socket close time).
247 407
254A string used to identify the remote site - usually the DNS hostname 414A string used to identify the remote site - usually the DNS hostname
255(I<not> IDN!) used to create the connection, rarely the IP address. 415(I<not> IDN!) used to create the connection, rarely the IP address.
256 416
257Apart from being useful in error messages, this string is also used in TLS 417Apart from being useful in error messages, this string is also used in TLS
258peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This 418peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
259verification will be skipped when C<peername> is not specified or 419verification will be skipped when C<peername> is not specified or is
260C<undef>. 420C<undef>.
261 421
262=item tls => "accept" | "connect" | Net::SSLeay::SSL object 422=item tls => "accept" | "connect" | Net::SSLeay::SSL object
263 423
264When this parameter is given, it enables TLS (SSL) mode, that means 424When this parameter is given, it enables TLS (SSL) mode, that means
265AnyEvent will start a TLS handshake as soon as the conenction has been 425AnyEvent will start a TLS handshake as soon as the connection has been
266established and will transparently encrypt/decrypt data afterwards. 426established and will transparently encrypt/decrypt data afterwards.
267 427
268All TLS protocol errors will be signalled as C<EPROTO>, with an 428All TLS protocol errors will be signalled as C<EPROTO>, with an
269appropriate error message. 429appropriate error message.
270 430
271TLS mode requires Net::SSLeay to be installed (it will be loaded 431TLS mode requires Net::SSLeay to be installed (it will be loaded
272automatically when you try to create a TLS handle): this module doesn't 432automatically when you try to create a TLS handle): this module doesn't
273have a dependency on that module, so if your module requires it, you have 433have a dependency on that module, so if your module requires it, you have
274to add the dependency yourself. 434to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
435old, you get an C<EPROTO> error.
275 436
276Unlike TCP, TLS has a server and client side: for the TLS server side, use 437Unlike TCP, TLS has a server and client side: for the TLS server side, use
277C<accept>, and for the TLS client side of a connection, use C<connect> 438C<accept>, and for the TLS client side of a connection, use C<connect>
278mode. 439mode.
279 440
290B<IMPORTANT:> since Net::SSLeay "objects" are really only integers, 451B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
291passing in the wrong integer will lead to certain crash. This most often 452passing in the wrong integer will lead to certain crash. This most often
292happens when one uses a stylish C<< tls => 1 >> and is surprised about the 453happens when one uses a stylish C<< tls => 1 >> and is surprised about the
293segmentation fault. 454segmentation fault.
294 455
295See the C<< ->starttls >> method for when need to start TLS negotiation later. 456Use the C<< ->starttls >> method if you need to start TLS negotiation later.
296 457
297=item tls_ctx => $anyevent_tls 458=item tls_ctx => $anyevent_tls
298 459
299Use the given C<AnyEvent::TLS> object to create the new TLS connection 460Use the given C<AnyEvent::TLS> object to create the new TLS connection
300(unless a connection object was specified directly). If this parameter is 461(unless a connection object was specified directly). If this
301missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 462parameter is missing (or C<undef>), then AnyEvent::Handle will use
463C<AnyEvent::Handle::TLS_CTX>.
302 464
303Instead of an object, you can also specify a hash reference with C<< key 465Instead of an object, you can also specify a hash reference with C<< key
304=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a 466=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
305new TLS context object. 467new TLS context object.
306 468
315 477
316TLS handshake failures will not cause C<on_error> to be invoked when this 478TLS handshake failures will not cause C<on_error> to be invoked when this
317callback is in effect, instead, the error message will be passed to C<on_starttls>. 479callback is in effect, instead, the error message will be passed to C<on_starttls>.
318 480
319Without this callback, handshake failures lead to C<on_error> being 481Without this callback, handshake failures lead to C<on_error> being
320called, as normal. 482called as usual.
321 483
322Note that you cannot call C<starttls> right again in this callback. If you 484Note that you cannot just call C<starttls> again in this callback. If you
323need to do that, start an zero-second timer instead whose callback can 485need to do that, start an zero-second timer instead whose callback can
324then call C<< ->starttls >> again. 486then call C<< ->starttls >> again.
325 487
326=item on_stoptls => $cb->($handle) 488=item on_stoptls => $cb->($handle)
327 489
353 515
354sub new { 516sub new {
355 my $class = shift; 517 my $class = shift;
356 my $self = bless { @_ }, $class; 518 my $self = bless { @_ }, $class;
357 519
358 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 520 if ($self->{fh}) {
521 $self->_start;
522 return unless $self->{fh}; # could be gone by now
523
524 } elsif ($self->{connect}) {
525 require AnyEvent::Socket;
526
527 $self->{peername} = $self->{connect}[0]
528 unless exists $self->{peername};
529
530 $self->{_skip_drain_rbuf} = 1;
531
532 {
533 Scalar::Util::weaken (my $self = $self);
534
535 $self->{_connect} =
536 AnyEvent::Socket::tcp_connect (
537 $self->{connect}[0],
538 $self->{connect}[1],
539 sub {
540 my ($fh, $host, $port, $retry) = @_;
541
542 delete $self->{_connect}; # no longer needed
543
544 if ($fh) {
545 $self->{fh} = $fh;
546
547 delete $self->{_skip_drain_rbuf};
548 $self->_start;
549
550 $self->{on_connect}
551 and $self->{on_connect}($self, $host, $port, sub {
552 delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
553 $self->{_skip_drain_rbuf} = 1;
554 &$retry;
555 });
556
557 } else {
558 if ($self->{on_connect_error}) {
559 $self->{on_connect_error}($self, "$!");
560 $self->destroy if $self;
561 } else {
562 $self->_error ($!, 1);
563 }
564 }
565 },
566 sub {
567 local $self->{fh} = $_[0];
568
569 $self->{on_prepare}
570 ? $self->{on_prepare}->($self)
571 : ()
572 }
573 );
574 }
575
576 } else {
577 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
578 }
579
580 $self
581}
582
583sub _start {
584 my ($self) = @_;
585
586 # too many clueless people try to use udp and similar sockets
587 # with AnyEvent::Handle, do them a favour.
588 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
589 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
590 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
359 591
360 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 592 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
361 593
594 $self->{_activity} =
595 $self->{_ractivity} =
362 $self->{_activity} = AnyEvent->now; 596 $self->{_wactivity} = AE::now;
363 $self->_timeout;
364 597
598 $self->{read_size} ||= 2048;
599 $self->{max_read_size} = $self->{read_size}
600 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
601
602 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
603 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
604 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
605
365 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay}; 606 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
607 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
366 608
609 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
610
367 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}) 611 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
368 if $self->{tls}; 612 if $self->{tls};
369 613
370 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 614 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
371 615
372 $self->start_read 616 $self->start_read
373 if $self->{on_read}; 617 if $self->{on_read} || @{ $self->{_queue} };
374 618
375 $self->{fh} && $self 619 $self->_drain_wbuf;
376} 620}
377
378#sub _shutdown {
379# my ($self) = @_;
380#
381# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
382# $self->{_eof} = 1; # tell starttls et. al to stop trying
383#
384# &_freetls;
385#}
386 621
387sub _error { 622sub _error {
388 my ($self, $errno, $fatal, $message) = @_; 623 my ($self, $errno, $fatal, $message) = @_;
389 624
390 $! = $errno; 625 $! = $errno;
391 $message ||= "$!"; 626 $message ||= "$!";
392 627
393 if ($self->{on_error}) { 628 if ($self->{on_error}) {
394 $self->{on_error}($self, $fatal, $message); 629 $self->{on_error}($self, $fatal, $message);
395 $self->destroy if $fatal; 630 $self->destroy if $fatal;
396 } elsif ($self->{fh}) { 631 } elsif ($self->{fh} || $self->{connect}) {
397 $self->destroy; 632 $self->destroy;
398 Carp::croak "AnyEvent::Handle uncaught error: $message"; 633 Carp::croak "AnyEvent::Handle uncaught error: $message";
399 } 634 }
400} 635}
401 636
427 $_[0]{on_eof} = $_[1]; 662 $_[0]{on_eof} = $_[1];
428} 663}
429 664
430=item $handle->on_timeout ($cb) 665=item $handle->on_timeout ($cb)
431 666
432Replace the current C<on_timeout> callback, or disables the callback (but 667=item $handle->on_rtimeout ($cb)
433not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
434argument and method.
435 668
436=cut 669=item $handle->on_wtimeout ($cb)
437 670
438sub on_timeout { 671Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
439 $_[0]{on_timeout} = $_[1]; 672callback, or disables the callback (but not the timeout) if C<$cb> =
440} 673C<undef>. See the C<timeout> constructor argument and method.
674
675=cut
676
677# see below
441 678
442=item $handle->autocork ($boolean) 679=item $handle->autocork ($boolean)
443 680
444Enables or disables the current autocork behaviour (see C<autocork> 681Enables or disables the current autocork behaviour (see C<autocork>
445constructor argument). Changes will only take effect on the next write. 682constructor argument). Changes will only take effect on the next write.
458=cut 695=cut
459 696
460sub no_delay { 697sub no_delay {
461 $_[0]{no_delay} = $_[1]; 698 $_[0]{no_delay} = $_[1];
462 699
700 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
701 if $_[0]{fh};
702}
703
704=item $handle->keepalive ($boolean)
705
706Enables or disables the C<keepalive> setting (see constructor argument of
707the same name for details).
708
709=cut
710
711sub keepalive {
712 $_[0]{keepalive} = $_[1];
713
463 eval { 714 eval {
464 local $SIG{__DIE__}; 715 local $SIG{__DIE__};
465 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]; 716 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
717 if $_[0]{fh};
718 };
719}
720
721=item $handle->oobinline ($boolean)
722
723Enables or disables the C<oobinline> setting (see constructor argument of
724the same name for details).
725
726=cut
727
728sub oobinline {
729 $_[0]{oobinline} = $_[1];
730
731 eval {
732 local $SIG{__DIE__};
733 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
734 if $_[0]{fh};
735 };
736}
737
738=item $handle->keepalive ($boolean)
739
740Enables or disables the C<keepalive> setting (see constructor argument of
741the same name for details).
742
743=cut
744
745sub keepalive {
746 $_[0]{keepalive} = $_[1];
747
748 eval {
749 local $SIG{__DIE__};
750 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
751 if $_[0]{fh};
466 }; 752 };
467} 753}
468 754
469=item $handle->on_starttls ($cb) 755=item $handle->on_starttls ($cb)
470 756
480 766
481Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument). 767Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
482 768
483=cut 769=cut
484 770
485sub on_starttls { 771sub on_stoptls {
486 $_[0]{on_stoptls} = $_[1]; 772 $_[0]{on_stoptls} = $_[1];
487} 773}
488 774
775=item $handle->rbuf_max ($max_octets)
776
777Configures the C<rbuf_max> setting (C<undef> disables it).
778
779=item $handle->wbuf_max ($max_octets)
780
781Configures the C<wbuf_max> setting (C<undef> disables it).
782
783=cut
784
785sub rbuf_max {
786 $_[0]{rbuf_max} = $_[1];
787}
788
789sub wbuf_max {
790 $_[0]{wbuf_max} = $_[1];
791}
792
489############################################################################# 793#############################################################################
490 794
491=item $handle->timeout ($seconds) 795=item $handle->timeout ($seconds)
492 796
797=item $handle->rtimeout ($seconds)
798
799=item $handle->wtimeout ($seconds)
800
493Configures (or disables) the inactivity timeout. 801Configures (or disables) the inactivity timeout.
494 802
495=cut 803The timeout will be checked instantly, so this method might destroy the
804handle before it returns.
496 805
497sub timeout { 806=item $handle->timeout_reset
807
808=item $handle->rtimeout_reset
809
810=item $handle->wtimeout_reset
811
812Reset the activity timeout, as if data was received or sent.
813
814These methods are cheap to call.
815
816=cut
817
818for my $dir ("", "r", "w") {
819 my $timeout = "${dir}timeout";
820 my $tw = "_${dir}tw";
821 my $on_timeout = "on_${dir}timeout";
822 my $activity = "_${dir}activity";
823 my $cb;
824
825 *$on_timeout = sub {
826 $_[0]{$on_timeout} = $_[1];
827 };
828
829 *$timeout = sub {
498 my ($self, $timeout) = @_; 830 my ($self, $new_value) = @_;
499 831
832 $new_value >= 0
833 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
834
500 $self->{timeout} = $timeout; 835 $self->{$timeout} = $new_value;
501 $self->_timeout; 836 delete $self->{$tw}; &$cb;
502} 837 };
503 838
839 *{"${dir}timeout_reset"} = sub {
840 $_[0]{$activity} = AE::now;
841 };
842
843 # main workhorse:
504# reset the timeout watcher, as neccessary 844 # reset the timeout watcher, as neccessary
505# also check for time-outs 845 # also check for time-outs
506sub _timeout { 846 $cb = sub {
507 my ($self) = @_; 847 my ($self) = @_;
508 848
509 if ($self->{timeout}) { 849 if ($self->{$timeout} && $self->{fh}) {
510 my $NOW = AnyEvent->now; 850 my $NOW = AE::now;
511 851
512 # when would the timeout trigger? 852 # when would the timeout trigger?
513 my $after = $self->{_activity} + $self->{timeout} - $NOW; 853 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
514 854
515 # now or in the past already? 855 # now or in the past already?
516 if ($after <= 0) { 856 if ($after <= 0) {
517 $self->{_activity} = $NOW; 857 $self->{$activity} = $NOW;
518 858
519 if ($self->{on_timeout}) { 859 if ($self->{$on_timeout}) {
520 $self->{on_timeout}($self); 860 $self->{$on_timeout}($self);
521 } else { 861 } else {
522 $self->_error (Errno::ETIMEDOUT); 862 $self->_error (Errno::ETIMEDOUT);
863 }
864
865 # callback could have changed timeout value, optimise
866 return unless $self->{$timeout};
867
868 # calculate new after
869 $after = $self->{$timeout};
523 } 870 }
524 871
525 # callback could have changed timeout value, optimise 872 Scalar::Util::weaken $self;
526 return unless $self->{timeout}; 873 return unless $self; # ->error could have destroyed $self
527 874
528 # calculate new after 875 $self->{$tw} ||= AE::timer $after, 0, sub {
529 $after = $self->{timeout}; 876 delete $self->{$tw};
877 $cb->($self);
878 };
879 } else {
880 delete $self->{$tw};
530 } 881 }
531
532 Scalar::Util::weaken $self;
533 return unless $self; # ->error could have destroyed $self
534
535 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
536 delete $self->{_tw};
537 $self->_timeout;
538 });
539 } else {
540 delete $self->{_tw};
541 } 882 }
542} 883}
543 884
544############################################################################# 885#############################################################################
545 886
552 893
553The write queue is very simple: you can add data to its end, and 894The write queue is very simple: you can add data to its end, and
554AnyEvent::Handle will automatically try to get rid of it for you. 895AnyEvent::Handle will automatically try to get rid of it for you.
555 896
556When data could be written and the write buffer is shorter then the low 897When data could be written and the write buffer is shorter then the low
557water mark, the C<on_drain> callback will be invoked. 898water mark, the C<on_drain> callback will be invoked once.
558 899
559=over 4 900=over 4
560 901
561=item $handle->on_drain ($cb) 902=item $handle->on_drain ($cb)
562 903
563Sets the C<on_drain> callback or clears it (see the description of 904Sets the C<on_drain> callback or clears it (see the description of
564C<on_drain> in the constructor). 905C<on_drain> in the constructor).
565 906
907This method may invoke callbacks (and therefore the handle might be
908destroyed after it returns).
909
566=cut 910=cut
567 911
568sub on_drain { 912sub on_drain {
569 my ($self, $cb) = @_; 913 my ($self, $cb) = @_;
570 914
574 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}); 918 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
575} 919}
576 920
577=item $handle->push_write ($data) 921=item $handle->push_write ($data)
578 922
579Queues the given scalar to be written. You can push as much data as you 923Queues the given scalar to be written. You can push as much data as
580want (only limited by the available memory), as C<AnyEvent::Handle> 924you want (only limited by the available memory and C<wbuf_max>), as
581buffers it independently of the kernel. 925C<AnyEvent::Handle> buffers it independently of the kernel.
926
927This method may invoke callbacks (and therefore the handle might be
928destroyed after it returns).
582 929
583=cut 930=cut
584 931
585sub _drain_wbuf { 932sub _drain_wbuf {
586 my ($self) = @_; 933 my ($self) = @_;
593 my $len = syswrite $self->{fh}, $self->{wbuf}; 940 my $len = syswrite $self->{fh}, $self->{wbuf};
594 941
595 if (defined $len) { 942 if (defined $len) {
596 substr $self->{wbuf}, 0, $len, ""; 943 substr $self->{wbuf}, 0, $len, "";
597 944
598 $self->{_activity} = AnyEvent->now; 945 $self->{_activity} = $self->{_wactivity} = AE::now;
599 946
600 $self->{on_drain}($self) 947 $self->{on_drain}($self)
601 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}) 948 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
602 && $self->{on_drain}; 949 && $self->{on_drain};
603 950
609 956
610 # try to write data immediately 957 # try to write data immediately
611 $cb->() unless $self->{autocork}; 958 $cb->() unless $self->{autocork};
612 959
613 # if still data left in wbuf, we need to poll 960 # if still data left in wbuf, we need to poll
614 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 961 $self->{_ww} = AE::io $self->{fh}, 1, $cb
615 if length $self->{wbuf}; 962 if length $self->{wbuf};
963
964 if (
965 defined $self->{wbuf_max}
966 && $self->{wbuf_max} < length $self->{wbuf}
967 ) {
968 $self->_error (Errno::ENOSPC, 1), return;
969 }
616 }; 970 };
617} 971}
618 972
619our %WH; 973our %WH;
620 974
975# deprecated
621sub register_write_type($$) { 976sub register_write_type($$) {
622 $WH{$_[0]} = $_[1]; 977 $WH{$_[0]} = $_[1];
623} 978}
624 979
625sub push_write { 980sub push_write {
626 my $self = shift; 981 my $self = shift;
627 982
628 if (@_ > 1) { 983 if (@_ > 1) {
629 my $type = shift; 984 my $type = shift;
630 985
986 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
631 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 987 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
632 ->($self, @_); 988 ->($self, @_);
633 } 989 }
634 990
991 # we downgrade here to avoid hard-to-track-down bugs,
992 # and diagnose the problem earlier and better.
993
635 if ($self->{tls}) { 994 if ($self->{tls}) {
636 $self->{_tls_wbuf} .= $_[0]; 995 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
637 996 &_dotls ($self) if $self->{fh};
638 &_dotls ($self);
639 } else { 997 } else {
640 $self->{wbuf} .= $_[0]; 998 utf8::downgrade $self->{wbuf} .= $_[0];
641 $self->_drain_wbuf; 999 $self->_drain_wbuf if $self->{fh};
642 } 1000 }
643} 1001}
644 1002
645=item $handle->push_write (type => @args) 1003=item $handle->push_write (type => @args)
646 1004
647Instead of formatting your data yourself, you can also let this module do 1005Instead of formatting your data yourself, you can also let this module
648the job by specifying a type and type-specific arguments. 1006do the job by specifying a type and type-specific arguments. You
1007can also specify the (fully qualified) name of a package, in which
1008case AnyEvent tries to load the package and then expects to find the
1009C<anyevent_write_type> function inside (see "custom write types", below).
649 1010
650Predefined types are (if you have ideas for additional types, feel free to 1011Predefined types are (if you have ideas for additional types, feel free to
651drop by and tell us): 1012drop by and tell us):
652 1013
653=over 4 1014=over 4
710Other languages could read single lines terminated by a newline and pass 1071Other languages could read single lines terminated by a newline and pass
711this line into their JSON decoder of choice. 1072this line into their JSON decoder of choice.
712 1073
713=cut 1074=cut
714 1075
1076sub json_coder() {
1077 eval { require JSON::XS; JSON::XS->new->utf8 }
1078 || do { require JSON; JSON->new->utf8 }
1079}
1080
715register_write_type json => sub { 1081register_write_type json => sub {
716 my ($self, $ref) = @_; 1082 my ($self, $ref) = @_;
717 1083
718 require JSON; 1084 my $json = $self->{json} ||= json_coder;
719 1085
720 $self->{json} ? $self->{json}->encode ($ref) 1086 $json->encode ($ref)
721 : JSON::encode_json ($ref)
722}; 1087};
723 1088
724=item storable => $reference 1089=item storable => $reference
725 1090
726Freezes the given reference using L<Storable> and writes it to the 1091Freezes the given reference using L<Storable> and writes it to the
729=cut 1094=cut
730 1095
731register_write_type storable => sub { 1096register_write_type storable => sub {
732 my ($self, $ref) = @_; 1097 my ($self, $ref) = @_;
733 1098
734 require Storable; 1099 require Storable unless $Storable::VERSION;
735 1100
736 pack "w/a*", Storable::nfreeze ($ref) 1101 pack "w/a*", Storable::nfreeze ($ref)
737}; 1102};
738 1103
739=back 1104=back
744before it was actually written. One way to do that is to replace your 1109before it was actually written. One way to do that is to replace your
745C<on_drain> handler by a callback that shuts down the socket (and set 1110C<on_drain> handler by a callback that shuts down the socket (and set
746C<low_water_mark> to C<0>). This method is a shorthand for just that, and 1111C<low_water_mark> to C<0>). This method is a shorthand for just that, and
747replaces the C<on_drain> callback with: 1112replaces the C<on_drain> callback with:
748 1113
749 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown 1114 sub { shutdown $_[0]{fh}, 1 }
750 1115
751This simply shuts down the write side and signals an EOF condition to the 1116This simply shuts down the write side and signals an EOF condition to the
752the peer. 1117the peer.
753 1118
754You can rely on the normal read queue and C<on_eof> handling 1119You can rely on the normal read queue and C<on_eof> handling
755afterwards. This is the cleanest way to close a connection. 1120afterwards. This is the cleanest way to close a connection.
756 1121
1122This method may invoke callbacks (and therefore the handle might be
1123destroyed after it returns).
1124
757=cut 1125=cut
758 1126
759sub push_shutdown { 1127sub push_shutdown {
760 my ($self) = @_; 1128 my ($self) = @_;
761 1129
762 delete $self->{low_water_mark}; 1130 delete $self->{low_water_mark};
763 $self->on_drain (sub { shutdown $_[0]{fh}, 1 }); 1131 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
764} 1132}
765 1133
766=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1134=item custom write types - Package::anyevent_write_type $handle, @args
767 1135
768This function (not method) lets you add your own types to C<push_write>. 1136Instead of one of the predefined types, you can also specify the name of
1137a package. AnyEvent will try to load the package and then expects to find
1138a function named C<anyevent_write_type> inside. If it isn't found, it
1139progressively tries to load the parent package until it either finds the
1140function (good) or runs out of packages (bad).
1141
769Whenever the given C<type> is used, C<push_write> will invoke the code 1142Whenever the given C<type> is used, C<push_write> will the function with
770reference with the handle object and the remaining arguments. 1143the handle object and the remaining arguments.
771 1144
772The code reference is supposed to return a single octet string that will 1145The function is supposed to return a single octet string that will be
773be appended to the write buffer. 1146appended to the write buffer, so you can mentally treat this function as a
1147"arguments to on-the-wire-format" converter.
774 1148
775Note that this is a function, and all types registered this way will be 1149Example: implement a custom write type C<join> that joins the remaining
776global, so try to use unique names. 1150arguments using the first one.
1151
1152 $handle->push_write (My::Type => " ", 1,2,3);
1153
1154 # uses the following package, which can be defined in the "My::Type" or in
1155 # the "My" modules to be auto-loaded, or just about anywhere when the
1156 # My::Type::anyevent_write_type is defined before invoking it.
1157
1158 package My::Type;
1159
1160 sub anyevent_write_type {
1161 my ($handle, $delim, @args) = @_;
1162
1163 join $delim, @args
1164 }
777 1165
778=cut 1166=cut
779 1167
780############################################################################# 1168#############################################################################
781 1169
790ways, the "simple" way, using only C<on_read> and the "complex" way, using 1178ways, the "simple" way, using only C<on_read> and the "complex" way, using
791a queue. 1179a queue.
792 1180
793In the simple case, you just install an C<on_read> callback and whenever 1181In the simple case, you just install an C<on_read> callback and whenever
794new data arrives, it will be called. You can then remove some data (if 1182new data arrives, it will be called. You can then remove some data (if
795enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna 1183enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
796leave the data there if you want to accumulate more (e.g. when only a 1184leave the data there if you want to accumulate more (e.g. when only a
797partial message has been received so far). 1185partial message has been received so far), or change the read queue with
1186e.g. C<push_read>.
798 1187
799In the more complex case, you want to queue multiple callbacks. In this 1188In the more complex case, you want to queue multiple callbacks. In this
800case, AnyEvent::Handle will call the first queued callback each time new 1189case, AnyEvent::Handle will call the first queued callback each time new
801data arrives (also the first time it is queued) and removes it when it has 1190data arrives (also the first time it is queued) and remove it when it has
802done its job (see C<push_read>, below). 1191done its job (see C<push_read>, below).
803 1192
804This way you can, for example, push three line-reads, followed by reading 1193This way you can, for example, push three line-reads, followed by reading
805a chunk of data, and AnyEvent::Handle will execute them in order. 1194a chunk of data, and AnyEvent::Handle will execute them in order.
806 1195
863=cut 1252=cut
864 1253
865sub _drain_rbuf { 1254sub _drain_rbuf {
866 my ($self) = @_; 1255 my ($self) = @_;
867 1256
1257 # avoid recursion
1258 return if $self->{_skip_drain_rbuf};
868 local $self->{_in_drain} = 1; 1259 local $self->{_skip_drain_rbuf} = 1;
869
870 if (
871 defined $self->{rbuf_max}
872 && $self->{rbuf_max} < length $self->{rbuf}
873 ) {
874 $self->_error (Errno::ENOSPC, 1), return;
875 }
876 1260
877 while () { 1261 while () {
878 # we need to use a separate tls read buffer, as we must not receive data while 1262 # we need to use a separate tls read buffer, as we must not receive data while
879 # we are draining the buffer, and this can only happen with TLS. 1263 # we are draining the buffer, and this can only happen with TLS.
880 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf}; 1264 $self->{rbuf} .= delete $self->{_tls_rbuf}
1265 if exists $self->{_tls_rbuf};
881 1266
882 my $len = length $self->{rbuf}; 1267 my $len = length $self->{rbuf};
883 1268
884 if (my $cb = shift @{ $self->{_queue} }) { 1269 if (my $cb = shift @{ $self->{_queue} }) {
885 unless ($cb->($self)) { 1270 unless ($cb->($self)) {
886 if ($self->{_eof}) { 1271 # no progress can be made
887 # no progress can be made (not enough data and no data forthcoming) 1272 # (not enough data and no data forthcoming)
888 $self->_error (Errno::EPIPE, 1), return; 1273 $self->_error (Errno::EPIPE, 1), return
889 } 1274 if $self->{_eof};
890 1275
891 unshift @{ $self->{_queue} }, $cb; 1276 unshift @{ $self->{_queue} }, $cb;
892 last; 1277 last;
893 } 1278 }
894 } elsif ($self->{on_read}) { 1279 } elsif ($self->{on_read}) {
914 last; 1299 last;
915 } 1300 }
916 } 1301 }
917 1302
918 if ($self->{_eof}) { 1303 if ($self->{_eof}) {
919 if ($self->{on_eof}) { 1304 $self->{on_eof}
920 $self->{on_eof}($self) 1305 ? $self->{on_eof}($self)
921 } else {
922 $self->_error (0, 1, "Unexpected end-of-file"); 1306 : $self->_error (0, 1, "Unexpected end-of-file");
923 } 1307
1308 return;
1309 }
1310
1311 if (
1312 defined $self->{rbuf_max}
1313 && $self->{rbuf_max} < length $self->{rbuf}
1314 ) {
1315 $self->_error (Errno::ENOSPC, 1), return;
924 } 1316 }
925 1317
926 # may need to restart read watcher 1318 # may need to restart read watcher
927 unless ($self->{_rw}) { 1319 unless ($self->{_rw}) {
928 $self->start_read 1320 $self->start_read
934 1326
935This replaces the currently set C<on_read> callback, or clears it (when 1327This replaces the currently set C<on_read> callback, or clears it (when
936the new callback is C<undef>). See the description of C<on_read> in the 1328the new callback is C<undef>). See the description of C<on_read> in the
937constructor. 1329constructor.
938 1330
1331This method may invoke callbacks (and therefore the handle might be
1332destroyed after it returns).
1333
939=cut 1334=cut
940 1335
941sub on_read { 1336sub on_read {
942 my ($self, $cb) = @_; 1337 my ($self, $cb) = @_;
943 1338
944 $self->{on_read} = $cb; 1339 $self->{on_read} = $cb;
945 $self->_drain_rbuf if $cb && !$self->{_in_drain}; 1340 $self->_drain_rbuf if $cb;
946} 1341}
947 1342
948=item $handle->rbuf 1343=item $handle->rbuf
949 1344
950Returns the read buffer (as a modifiable lvalue). 1345Returns the read buffer (as a modifiable lvalue). You can also access the
1346read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1347much faster, and no less clean).
951 1348
952You can access the read buffer directly as the C<< ->{rbuf} >> 1349The only operation allowed on the read buffer (apart from looking at it)
953member, if you want. However, the only operation allowed on the 1350is removing data from its beginning. Otherwise modifying or appending to
954read buffer (apart from looking at it) is removing data from its 1351it is not allowed and will lead to hard-to-track-down bugs.
955beginning. Otherwise modifying or appending to it is not allowed and will
956lead to hard-to-track-down bugs.
957 1352
958NOTE: The read buffer should only be used or modified if the C<on_read>, 1353NOTE: The read buffer should only be used or modified in the C<on_read>
959C<push_read> or C<unshift_read> methods are used. The other read methods 1354callback or when C<push_read> or C<unshift_read> are used with a single
960automatically manage the read buffer. 1355callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1356will manage the read buffer on their own.
961 1357
962=cut 1358=cut
963 1359
964sub rbuf : lvalue { 1360sub rbuf : lvalue {
965 $_[0]{rbuf} 1361 $_[0]{rbuf}
982 1378
983If enough data was available, then the callback must remove all data it is 1379If enough data was available, then the callback must remove all data it is
984interested in (which can be none at all) and return a true value. After returning 1380interested in (which can be none at all) and return a true value. After returning
985true, it will be removed from the queue. 1381true, it will be removed from the queue.
986 1382
1383These methods may invoke callbacks (and therefore the handle might be
1384destroyed after it returns).
1385
987=cut 1386=cut
988 1387
989our %RH; 1388our %RH;
990 1389
991sub register_read_type($$) { 1390sub register_read_type($$) {
997 my $cb = pop; 1396 my $cb = pop;
998 1397
999 if (@_) { 1398 if (@_) {
1000 my $type = shift; 1399 my $type = shift;
1001 1400
1401 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1002 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 1402 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
1003 ->($self, $cb, @_); 1403 ->($self, $cb, @_);
1004 } 1404 }
1005 1405
1006 push @{ $self->{_queue} }, $cb; 1406 push @{ $self->{_queue} }, $cb;
1007 $self->_drain_rbuf unless $self->{_in_drain}; 1407 $self->_drain_rbuf;
1008} 1408}
1009 1409
1010sub unshift_read { 1410sub unshift_read {
1011 my $self = shift; 1411 my $self = shift;
1012 my $cb = pop; 1412 my $cb = pop;
1013 1413
1014 if (@_) { 1414 if (@_) {
1015 my $type = shift; 1415 my $type = shift;
1016 1416
1417 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1017 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1418 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
1018 ->($self, $cb, @_); 1419 ->($self, $cb, @_);
1019 } 1420 }
1020 1421
1021
1022 unshift @{ $self->{_queue} }, $cb; 1422 unshift @{ $self->{_queue} }, $cb;
1023 $self->_drain_rbuf unless $self->{_in_drain}; 1423 $self->_drain_rbuf;
1024} 1424}
1025 1425
1026=item $handle->push_read (type => @args, $cb) 1426=item $handle->push_read (type => @args, $cb)
1027 1427
1028=item $handle->unshift_read (type => @args, $cb) 1428=item $handle->unshift_read (type => @args, $cb)
1029 1429
1030Instead of providing a callback that parses the data itself you can chose 1430Instead of providing a callback that parses the data itself you can chose
1031between a number of predefined parsing formats, for chunks of data, lines 1431between a number of predefined parsing formats, for chunks of data, lines
1032etc. 1432etc. You can also specify the (fully qualified) name of a package, in
1433which case AnyEvent tries to load the package and then expects to find the
1434C<anyevent_read_type> function inside (see "custom read types", below).
1033 1435
1034Predefined types are (if you have ideas for additional types, feel free to 1436Predefined types are (if you have ideas for additional types, feel free to
1035drop by and tell us): 1437drop by and tell us):
1036 1438
1037=over 4 1439=over 4
1043data. 1445data.
1044 1446
1045Example: read 2 bytes. 1447Example: read 2 bytes.
1046 1448
1047 $handle->push_read (chunk => 2, sub { 1449 $handle->push_read (chunk => 2, sub {
1048 warn "yay ", unpack "H*", $_[1]; 1450 say "yay " . unpack "H*", $_[1];
1049 }); 1451 });
1050 1452
1051=cut 1453=cut
1052 1454
1053register_read_type chunk => sub { 1455register_read_type chunk => sub {
1087 if (@_ < 3) { 1489 if (@_ < 3) {
1088 # this is more than twice as fast as the generic code below 1490 # this is more than twice as fast as the generic code below
1089 sub { 1491 sub {
1090 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return; 1492 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1091 1493
1092 $cb->($_[0], $1, $2); 1494 $cb->($_[0], "$1", "$2");
1093 1 1495 1
1094 } 1496 }
1095 } else { 1497 } else {
1096 $eol = quotemeta $eol unless ref $eol; 1498 $eol = quotemeta $eol unless ref $eol;
1097 $eol = qr|^(.*?)($eol)|s; 1499 $eol = qr|^(.*?)($eol)|s;
1098 1500
1099 sub { 1501 sub {
1100 $_[0]{rbuf} =~ s/$eol// or return; 1502 $_[0]{rbuf} =~ s/$eol// or return;
1101 1503
1102 $cb->($_[0], $1, $2); 1504 $cb->($_[0], "$1", "$2");
1103 1 1505 1
1104 } 1506 }
1105 } 1507 }
1106}; 1508};
1107 1509
1129the receive buffer when neither C<$accept> nor C<$reject> match, 1531the receive buffer when neither C<$accept> nor C<$reject> match,
1130and everything preceding and including the match will be accepted 1532and everything preceding and including the match will be accepted
1131unconditionally. This is useful to skip large amounts of data that you 1533unconditionally. This is useful to skip large amounts of data that you
1132know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1534know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1133have to start matching from the beginning. This is purely an optimisation 1535have to start matching from the beginning. This is purely an optimisation
1134and is usually worth only when you expect more than a few kilobytes. 1536and is usually worth it only when you expect more than a few kilobytes.
1135 1537
1136Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1538Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1137expect the header to be very large (it isn't in practise, but...), we use 1539expect the header to be very large (it isn't in practice, but...), we use
1138a skip regex to skip initial portions. The skip regex is tricky in that 1540a skip regex to skip initial portions. The skip regex is tricky in that
1139it only accepts something not ending in either \015 or \012, as these are 1541it only accepts something not ending in either \015 or \012, as these are
1140required for the accept regex. 1542required for the accept regex.
1141 1543
1142 $handle->push_read (regex => 1544 $handle->push_read (regex =>
1155 1557
1156 sub { 1558 sub {
1157 # accept 1559 # accept
1158 if ($$rbuf =~ $accept) { 1560 if ($$rbuf =~ $accept) {
1159 $data .= substr $$rbuf, 0, $+[0], ""; 1561 $data .= substr $$rbuf, 0, $+[0], "";
1160 $cb->($self, $data); 1562 $cb->($_[0], $data);
1161 return 1; 1563 return 1;
1162 } 1564 }
1163 1565
1164 # reject 1566 # reject
1165 if ($reject && $$rbuf =~ $reject) { 1567 if ($reject && $$rbuf =~ $reject) {
1166 $self->_error (Errno::EBADMSG); 1568 $_[0]->_error (Errno::EBADMSG);
1167 } 1569 }
1168 1570
1169 # skip 1571 # skip
1170 if ($skip && $$rbuf =~ $skip) { 1572 if ($skip && $$rbuf =~ $skip) {
1171 $data .= substr $$rbuf, 0, $+[0], ""; 1573 $data .= substr $$rbuf, 0, $+[0], "";
1187 my ($self, $cb) = @_; 1589 my ($self, $cb) = @_;
1188 1590
1189 sub { 1591 sub {
1190 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1592 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1191 if ($_[0]{rbuf} =~ /[^0-9]/) { 1593 if ($_[0]{rbuf} =~ /[^0-9]/) {
1192 $self->_error (Errno::EBADMSG); 1594 $_[0]->_error (Errno::EBADMSG);
1193 } 1595 }
1194 return; 1596 return;
1195 } 1597 }
1196 1598
1197 my $len = $1; 1599 my $len = $1;
1198 1600
1199 $self->unshift_read (chunk => $len, sub { 1601 $_[0]->unshift_read (chunk => $len, sub {
1200 my $string = $_[1]; 1602 my $string = $_[1];
1201 $_[0]->unshift_read (chunk => 1, sub { 1603 $_[0]->unshift_read (chunk => 1, sub {
1202 if ($_[1] eq ",") { 1604 if ($_[1] eq ",") {
1203 $cb->($_[0], $string); 1605 $cb->($_[0], $string);
1204 } else { 1606 } else {
1205 $self->_error (Errno::EBADMSG); 1607 $_[0]->_error (Errno::EBADMSG);
1206 } 1608 }
1207 }); 1609 });
1208 }); 1610 });
1209 1611
1210 1 1612 1
1277=cut 1679=cut
1278 1680
1279register_read_type json => sub { 1681register_read_type json => sub {
1280 my ($self, $cb) = @_; 1682 my ($self, $cb) = @_;
1281 1683
1282 my $json = $self->{json} ||= 1684 my $json = $self->{json} ||= json_coder;
1283 eval { require JSON::XS; JSON::XS->new->utf8 }
1284 || do { require JSON; JSON->new->utf8 };
1285 1685
1286 my $data; 1686 my $data;
1287 my $rbuf = \$self->{rbuf}; 1687 my $rbuf = \$self->{rbuf};
1288 1688
1289 sub { 1689 sub {
1290 my $ref = eval { $json->incr_parse ($self->{rbuf}) }; 1690 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1291 1691
1292 if ($ref) { 1692 if ($ref) {
1293 $self->{rbuf} = $json->incr_text; 1693 $_[0]{rbuf} = $json->incr_text;
1294 $json->incr_text = ""; 1694 $json->incr_text = "";
1295 $cb->($self, $ref); 1695 $cb->($_[0], $ref);
1296 1696
1297 1 1697 1
1298 } elsif ($@) { 1698 } elsif ($@) {
1299 # error case 1699 # error case
1300 $json->incr_skip; 1700 $json->incr_skip;
1301 1701
1302 $self->{rbuf} = $json->incr_text; 1702 $_[0]{rbuf} = $json->incr_text;
1303 $json->incr_text = ""; 1703 $json->incr_text = "";
1304 1704
1305 $self->_error (Errno::EBADMSG); 1705 $_[0]->_error (Errno::EBADMSG);
1306 1706
1307 () 1707 ()
1308 } else { 1708 } else {
1309 $self->{rbuf} = ""; 1709 $_[0]{rbuf} = "";
1310 1710
1311 () 1711 ()
1312 } 1712 }
1313 } 1713 }
1314}; 1714};
1324=cut 1724=cut
1325 1725
1326register_read_type storable => sub { 1726register_read_type storable => sub {
1327 my ($self, $cb) = @_; 1727 my ($self, $cb) = @_;
1328 1728
1329 require Storable; 1729 require Storable unless $Storable::VERSION;
1330 1730
1331 sub { 1731 sub {
1332 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method 1732 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1333 defined (my $len = eval { unpack "w", $_[0]{rbuf} }) 1733 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1334 or return; 1734 or return;
1337 1737
1338 # bypass unshift if we already have the remaining chunk 1738 # bypass unshift if we already have the remaining chunk
1339 if ($format + $len <= length $_[0]{rbuf}) { 1739 if ($format + $len <= length $_[0]{rbuf}) {
1340 my $data = substr $_[0]{rbuf}, $format, $len; 1740 my $data = substr $_[0]{rbuf}, $format, $len;
1341 substr $_[0]{rbuf}, 0, $format + $len, ""; 1741 substr $_[0]{rbuf}, 0, $format + $len, "";
1742
1342 $cb->($_[0], Storable::thaw ($data)); 1743 eval { $cb->($_[0], Storable::thaw ($data)); 1 }
1744 or return $_[0]->_error (Errno::EBADMSG);
1343 } else { 1745 } else {
1344 # remove prefix 1746 # remove prefix
1345 substr $_[0]{rbuf}, 0, $format, ""; 1747 substr $_[0]{rbuf}, 0, $format, "";
1346 1748
1347 # read remaining chunk 1749 # read remaining chunk
1348 $_[0]->unshift_read (chunk => $len, sub { 1750 $_[0]->unshift_read (chunk => $len, sub {
1349 if (my $ref = eval { Storable::thaw ($_[1]) }) { 1751 eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1350 $cb->($_[0], $ref);
1351 } else {
1352 $self->_error (Errno::EBADMSG); 1752 or $_[0]->_error (Errno::EBADMSG);
1353 }
1354 }); 1753 });
1355 } 1754 }
1356 1755
1357 1 1756 1
1358 } 1757 }
1359}; 1758};
1360 1759
1760=item tls_detect => $cb->($handle, $detect, $major, $minor)
1761
1762Checks the input stream for a valid SSL or TLS handshake TLSPaintext
1763record without consuming anything. Only SSL version 3 or higher
1764is handled, up to the fictituous protocol 4.x (but both SSL3+ and
1765SSL2-compatible framing is supported).
1766
1767If it detects that the input data is likely TLS, it calls the callback
1768with a true value for C<$detect> and the (on-wire) TLS version as second
1769and third argument (C<$major> is C<3>, and C<$minor> is 0..3 for SSL
17703.0, TLS 1.0, 1.1 and 1.2, respectively). If it detects the input to
1771be definitely not TLS, it calls the callback with a false value for
1772C<$detect>.
1773
1774The callback could use this information to decide whether or not to start
1775TLS negotiation.
1776
1777In all cases the data read so far is passed to the following read
1778handlers.
1779
1780Usually you want to use the C<tls_autostart> read type instead.
1781
1782If you want to design a protocol that works in the presence of TLS
1783dtection, make sure that any non-TLS data doesn't start with the octet 22
1784(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
1785read type does are a bit more strict, but might losen in the future to
1786accomodate protocol changes.
1787
1788This read type does not rely on L<AnyEvent::TLS> (and thus, not on
1789L<Net::SSLeay>).
1790
1791=item tls_autostart => $tls[, $tls_ctx]
1792
1793Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
1794to start tls by calling C<starttls> with the given arguments.
1795
1796In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
1797been configured to accept, as servers do not normally send a handshake on
1798their own and ths cannot be detected in this way.
1799
1800See C<tls_detect> above for more details.
1801
1802Example: give the client a chance to start TLS before accepting a text
1803line.
1804
1805 $hdl->push_read (tls_detect => "accept");
1806 $hdl->push_read (line => sub {
1807 print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
1808 });
1809
1810=cut
1811
1812register_read_type tls_detect => sub {
1813 my ($self, $cb) = @_;
1814
1815 sub {
1816 # this regex matches a full or partial tls record
1817 if (
1818 # ssl3+: type(22=handshake) major(=3) minor(any) length_hi
1819 $self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
1820 # ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
1821 or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
1822 ) {
1823 return if 3 != length $1; # partial match, can't decide yet
1824
1825 # full match, valid TLS record
1826 my ($major, $minor) = unpack "CC", $1;
1827 $cb->($self, "accept", $major + $minor * 0.1);
1828 } else {
1829 # mismatch == guaranteed not TLS
1830 $cb->($self, undef);
1831 }
1832
1833 1
1834 }
1835};
1836
1837register_read_type tls_autostart => sub {
1838 my ($self, @tls) = @_;
1839
1840 $RH{tls_detect}($self, sub {
1841 return unless $_[1];
1842 $_[0]->starttls (@tls);
1843 })
1844};
1845
1361=back 1846=back
1362 1847
1363=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1848=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1364 1849
1365This function (not method) lets you add your own types to C<push_read>. 1850Instead of one of the predefined types, you can also specify the name
1851of a package. AnyEvent will try to load the package and then expects to
1852find a function named C<anyevent_read_type> inside. If it isn't found, it
1853progressively tries to load the parent package until it either finds the
1854function (good) or runs out of packages (bad).
1366 1855
1367Whenever the given C<type> is used, C<push_read> will invoke the code 1856Whenever this type is used, C<push_read> will invoke the function with the
1368reference with the handle object, the callback and the remaining 1857handle object, the original callback and the remaining arguments.
1369arguments.
1370 1858
1371The code reference is supposed to return a callback (usually a closure) 1859The function is supposed to return a callback (usually a closure) that
1372that works as a plain read callback (see C<< ->push_read ($cb) >>). 1860works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1861mentally treat the function as a "configurable read type to read callback"
1862converter.
1373 1863
1374It should invoke the passed callback when it is done reading (remember to 1864It should invoke the original callback when it is done reading (remember
1375pass C<$handle> as first argument as all other callbacks do that). 1865to pass C<$handle> as first argument as all other callbacks do that,
1866although there is no strict requirement on this).
1376 1867
1377Note that this is a function, and all types registered this way will be
1378global, so try to use unique names.
1379
1380For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1868For examples, see the source of this module (F<perldoc -m
1381search for C<register_read_type>)). 1869AnyEvent::Handle>, search for C<register_read_type>)).
1382 1870
1383=item $handle->stop_read 1871=item $handle->stop_read
1384 1872
1385=item $handle->start_read 1873=item $handle->start_read
1386 1874
1392Note that AnyEvent::Handle will automatically C<start_read> for you when 1880Note that AnyEvent::Handle will automatically C<start_read> for you when
1393you change the C<on_read> callback or push/unshift a read callback, and it 1881you change the C<on_read> callback or push/unshift a read callback, and it
1394will automatically C<stop_read> for you when neither C<on_read> is set nor 1882will automatically C<stop_read> for you when neither C<on_read> is set nor
1395there are any read requests in the queue. 1883there are any read requests in the queue.
1396 1884
1397These methods will have no effect when in TLS mode (as TLS doesn't support 1885In older versions of this module (<= 5.3), these methods had no effect,
1398half-duplex connections). 1886as TLS does not support half-duplex connections. In current versions they
1887work as expected, as this behaviour is required to avoid certain resource
1888attacks, where the program would be forced to read (and buffer) arbitrary
1889amounts of data before being able to send some data. The drawback is that
1890some readings of the the SSL/TLS specifications basically require this
1891attack to be working, as SSL/TLS implementations might stall sending data
1892during a rehandshake.
1893
1894As a guideline, during the initial handshake, you should not stop reading,
1895and as a client, it might cause problems, depending on your application.
1399 1896
1400=cut 1897=cut
1401 1898
1402sub stop_read { 1899sub stop_read {
1403 my ($self) = @_; 1900 my ($self) = @_;
1404 1901
1405 delete $self->{_rw} unless $self->{tls}; 1902 delete $self->{_rw};
1406} 1903}
1407 1904
1408sub start_read { 1905sub start_read {
1409 my ($self) = @_; 1906 my ($self) = @_;
1410 1907
1411 unless ($self->{_rw} || $self->{_eof}) { 1908 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1412 Scalar::Util::weaken $self; 1909 Scalar::Util::weaken $self;
1413 1910
1414 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1911 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1415 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf}); 1912 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1416 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1913 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1417 1914
1418 if ($len > 0) { 1915 if ($len > 0) {
1419 $self->{_activity} = AnyEvent->now; 1916 $self->{_activity} = $self->{_ractivity} = AE::now;
1420 1917
1421 if ($self->{tls}) { 1918 if ($self->{tls}) {
1422 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); 1919 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1423 1920
1424 &_dotls ($self); 1921 &_dotls ($self);
1425 } else { 1922 } else {
1426 $self->_drain_rbuf unless $self->{_in_drain}; 1923 $self->_drain_rbuf;
1924 }
1925
1926 if ($len == $self->{read_size}) {
1927 $self->{read_size} *= 2;
1928 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1929 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1427 } 1930 }
1428 1931
1429 } elsif (defined $len) { 1932 } elsif (defined $len) {
1430 delete $self->{_rw}; 1933 delete $self->{_rw};
1431 $self->{_eof} = 1; 1934 $self->{_eof} = 1;
1432 $self->_drain_rbuf unless $self->{_in_drain}; 1935 $self->_drain_rbuf;
1433 1936
1434 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 1937 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1435 return $self->_error ($!, 1); 1938 return $self->_error ($!, 1);
1436 } 1939 }
1437 }); 1940 };
1438 } 1941 }
1439} 1942}
1440 1943
1441our $ERROR_SYSCALL; 1944our $ERROR_SYSCALL;
1442our $ERROR_WANT_READ; 1945our $ERROR_WANT_READ;
1445 my ($self, $err) = @_; 1948 my ($self, $err) = @_;
1446 1949
1447 return $self->_error ($!, 1) 1950 return $self->_error ($!, 1)
1448 if $err == Net::SSLeay::ERROR_SYSCALL (); 1951 if $err == Net::SSLeay::ERROR_SYSCALL ();
1449 1952
1450 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ()); 1953 my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1451 1954
1452 # reduce error string to look less scary 1955 # reduce error string to look less scary
1453 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /; 1956 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1454 1957
1455 if ($self->{_on_starttls}) { 1958 if ($self->{_on_starttls}) {
1497 $self->{_eof} = 1; 2000 $self->{_eof} = 1;
1498 } 2001 }
1499 } 2002 }
1500 2003
1501 $self->{_tls_rbuf} .= $tmp; 2004 $self->{_tls_rbuf} .= $tmp;
1502 $self->_drain_rbuf unless $self->{_in_drain}; 2005 $self->_drain_rbuf;
1503 $self->{tls} or return; # tls session might have gone away in callback 2006 $self->{tls} or return; # tls session might have gone away in callback
1504 } 2007 }
1505 2008
1506 $tmp = Net::SSLeay::get_error ($self->{tls}, -1); 2009 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1507 return $self->_tls_error ($tmp) 2010 return $self->_tls_error ($tmp)
1509 && ($tmp != $ERROR_SYSCALL || $!); 2012 && ($tmp != $ERROR_SYSCALL || $!);
1510 2013
1511 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) { 2014 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1512 $self->{wbuf} .= $tmp; 2015 $self->{wbuf} .= $tmp;
1513 $self->_drain_wbuf; 2016 $self->_drain_wbuf;
2017 $self->{tls} or return; # tls session might have gone away in callback
1514 } 2018 }
1515 2019
1516 $self->{_on_starttls} 2020 $self->{_on_starttls}
1517 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK () 2021 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1518 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established"); 2022 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1520 2024
1521=item $handle->starttls ($tls[, $tls_ctx]) 2025=item $handle->starttls ($tls[, $tls_ctx])
1522 2026
1523Instead of starting TLS negotiation immediately when the AnyEvent::Handle 2027Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1524object is created, you can also do that at a later time by calling 2028object is created, you can also do that at a later time by calling
1525C<starttls>. 2029C<starttls>. See the C<tls> constructor argument for general info.
2030
2031Starting TLS is currently an asynchronous operation - when you push some
2032write data and then call C<< ->starttls >> then TLS negotiation will start
2033immediately, after which the queued write data is then sent. This might
2034change in future versions, so best make sure you have no outstanding write
2035data when calling this method.
1526 2036
1527The first argument is the same as the C<tls> constructor argument (either 2037The first argument is the same as the C<tls> constructor argument (either
1528C<"connect">, C<"accept"> or an existing Net::SSLeay object). 2038C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1529 2039
1530The second argument is the optional C<AnyEvent::TLS> object that is used 2040The second argument is the optional C<AnyEvent::TLS> object that is used
1535The TLS connection object will end up in C<< $handle->{tls} >>, the TLS 2045The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1536context in C<< $handle->{tls_ctx} >> after this call and can be used or 2046context in C<< $handle->{tls_ctx} >> after this call and can be used or
1537changed to your liking. Note that the handshake might have already started 2047changed to your liking. Note that the handshake might have already started
1538when this function returns. 2048when this function returns.
1539 2049
1540If it an error to start a TLS handshake more than once per 2050Due to bugs in OpenSSL, it might or might not be possible to do multiple
1541AnyEvent::Handle object (this is due to bugs in OpenSSL). 2051handshakes on the same stream. It is best to not attempt to use the
2052stream after stopping TLS.
2053
2054This method may invoke callbacks (and therefore the handle might be
2055destroyed after it returns).
1542 2056
1543=cut 2057=cut
1544 2058
1545our %TLS_CACHE; #TODO not yet documented, should we? 2059our %TLS_CACHE; #TODO not yet documented, should we?
1546 2060
1547sub starttls { 2061sub starttls {
1548 my ($self, $ssl, $ctx) = @_; 2062 my ($self, $tls, $ctx) = @_;
1549 2063
1550 require Net::SSLeay; 2064 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1551
1552 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1553 if $self->{tls}; 2065 if $self->{tls};
2066
2067 unless (defined $AnyEvent::TLS::VERSION) {
2068 eval {
2069 require Net::SSLeay;
2070 require AnyEvent::TLS;
2071 1
2072 } or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
2073 }
2074
2075 $self->{tls} = $tls;
2076 $self->{tls_ctx} = $ctx if @_ > 2;
2077
2078 return unless $self->{fh};
1554 2079
1555 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL (); 2080 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1556 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ (); 2081 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1557 2082
2083 $tls = delete $self->{tls};
1558 $ctx ||= $self->{tls_ctx}; 2084 $ctx = $self->{tls_ctx};
2085
2086 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1559 2087
1560 if ("HASH" eq ref $ctx) { 2088 if ("HASH" eq ref $ctx) {
1561 require AnyEvent::TLS;
1562
1563 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1564
1565 if ($ctx->{cache}) { 2089 if ($ctx->{cache}) {
1566 my $key = $ctx+0; 2090 my $key = $ctx+0;
1567 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx; 2091 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1568 } else { 2092 } else {
1569 $ctx = new AnyEvent::TLS %$ctx; 2093 $ctx = new AnyEvent::TLS %$ctx;
1570 } 2094 }
1571 } 2095 }
1572 2096
1573 $self->{tls_ctx} = $ctx || TLS_CTX (); 2097 $self->{tls_ctx} = $ctx || TLS_CTX ();
1574 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername}); 2098 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1575 2099
1576 # basically, this is deep magic (because SSL_read should have the same issues) 2100 # basically, this is deep magic (because SSL_read should have the same issues)
1577 # but the openssl maintainers basically said: "trust us, it just works". 2101 # but the openssl maintainers basically said: "trust us, it just works".
1578 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 2102 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1579 # and mismaintained ssleay-module doesn't even offer them). 2103 # and mismaintained ssleay-module doesn't even offer them).
1586 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to 2110 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1587 # have identity issues in that area. 2111 # have identity issues in that area.
1588# Net::SSLeay::CTX_set_mode ($ssl, 2112# Net::SSLeay::CTX_set_mode ($ssl,
1589# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 2113# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1590# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 2114# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1591 Net::SSLeay::CTX_set_mode ($ssl, 1|2); 2115 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1592 2116
1593 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2117 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1594 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2118 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1595 2119
2120 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2121 $self->{rbuf} = "";
2122
1596 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2123 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1597 2124
1598 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) } 2125 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1599 if $self->{on_starttls}; 2126 if $self->{on_starttls};
1600 2127
1601 &_dotls; # need to trigger the initial handshake 2128 &_dotls; # need to trigger the initial handshake
1604 2131
1605=item $handle->stoptls 2132=item $handle->stoptls
1606 2133
1607Shuts down the SSL connection - this makes a proper EOF handshake by 2134Shuts down the SSL connection - this makes a proper EOF handshake by
1608sending a close notify to the other side, but since OpenSSL doesn't 2135sending a close notify to the other side, but since OpenSSL doesn't
1609support non-blocking shut downs, it is not possible to re-use the stream 2136support non-blocking shut downs, it is not guaranteed that you can re-use
1610afterwards. 2137the stream afterwards.
2138
2139This method may invoke callbacks (and therefore the handle might be
2140destroyed after it returns).
1611 2141
1612=cut 2142=cut
1613 2143
1614sub stoptls { 2144sub stoptls {
1615 my ($self) = @_; 2145 my ($self) = @_;
1616 2146
1617 if ($self->{tls}) { 2147 if ($self->{tls} && $self->{fh}) {
1618 Net::SSLeay::shutdown ($self->{tls}); 2148 Net::SSLeay::shutdown ($self->{tls});
1619 2149
1620 &_dotls; 2150 &_dotls;
1621 2151
1622# # we don't give a shit. no, we do, but we can't. no...#d# 2152# # we don't give a shit. no, we do, but we can't. no...#d#
1628sub _freetls { 2158sub _freetls {
1629 my ($self) = @_; 2159 my ($self) = @_;
1630 2160
1631 return unless $self->{tls}; 2161 return unless $self->{tls};
1632 2162
1633 $self->{tls_ctx}->_put_session (delete $self->{tls}); 2163 $self->{tls_ctx}->_put_session (delete $self->{tls})
2164 if $self->{tls} > 0;
1634 2165
1635 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)}; 2166 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1636} 2167}
1637 2168
2169=item $handle->resettls
2170
2171This rarely-used method simply resets and TLS state on the handle, usually
2172causing data loss.
2173
2174One case where it may be useful is when you want to skip over the data in
2175the stream but you are not interested in interpreting it, so data loss is
2176no concern.
2177
2178=cut
2179
2180*resettls = \&_freetls;
2181
1638sub DESTROY { 2182sub DESTROY {
1639 my ($self) = @_; 2183 my ($self) = @_;
1640 2184
1641 &_freetls; 2185 &_freetls;
1642 2186
1643 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 2187 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1644 2188
1645 if ($linger && length $self->{wbuf}) { 2189 if ($linger && length $self->{wbuf} && $self->{fh}) {
1646 my $fh = delete $self->{fh}; 2190 my $fh = delete $self->{fh};
1647 my $wbuf = delete $self->{wbuf}; 2191 my $wbuf = delete $self->{wbuf};
1648 2192
1649 my @linger; 2193 my @linger;
1650 2194
1651 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub { 2195 push @linger, AE::io $fh, 1, sub {
1652 my $len = syswrite $fh, $wbuf, length $wbuf; 2196 my $len = syswrite $fh, $wbuf, length $wbuf;
1653 2197
1654 if ($len > 0) { 2198 if ($len > 0) {
1655 substr $wbuf, 0, $len, ""; 2199 substr $wbuf, 0, $len, "";
1656 } else { 2200 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1657 @linger = (); # end 2201 @linger = (); # end
1658 } 2202 }
1659 }); 2203 };
1660 push @linger, AnyEvent->timer (after => $linger, cb => sub { 2204 push @linger, AE::timer $linger, 0, sub {
1661 @linger = (); 2205 @linger = ();
1662 }); 2206 };
1663 } 2207 }
1664} 2208}
1665 2209
1666=item $handle->destroy 2210=item $handle->destroy
1667 2211
1668Shuts down the handle object as much as possible - this call ensures that 2212Shuts down the handle object as much as possible - this call ensures that
1669no further callbacks will be invoked and as many resources as possible 2213no further callbacks will be invoked and as many resources as possible
1670will be freed. You must not call any methods on the object afterwards. 2214will be freed. Any method you will call on the handle object after
2215destroying it in this way will be silently ignored (and it will return the
2216empty list).
1671 2217
1672Normally, you can just "forget" any references to an AnyEvent::Handle 2218Normally, you can just "forget" any references to an AnyEvent::Handle
1673object and it will simply shut down. This works in fatal error and EOF 2219object and it will simply shut down. This works in fatal error and EOF
1674callbacks, as well as code outside. It does I<NOT> work in a read or write 2220callbacks, as well as code outside. It does I<NOT> work in a read or write
1675callback, so when you want to destroy the AnyEvent::Handle object from 2221callback, so when you want to destroy the AnyEvent::Handle object from
1689sub destroy { 2235sub destroy {
1690 my ($self) = @_; 2236 my ($self) = @_;
1691 2237
1692 $self->DESTROY; 2238 $self->DESTROY;
1693 %$self = (); 2239 %$self = ();
2240 bless $self, "AnyEvent::Handle::destroyed";
1694} 2241}
2242
2243sub AnyEvent::Handle::destroyed::AUTOLOAD {
2244 #nop
2245}
2246
2247=item $handle->destroyed
2248
2249Returns false as long as the handle hasn't been destroyed by a call to C<<
2250->destroy >>, true otherwise.
2251
2252Can be useful to decide whether the handle is still valid after some
2253callback possibly destroyed the handle. For example, C<< ->push_write >>,
2254C<< ->starttls >> and other methods can call user callbacks, which in turn
2255can destroy the handle, so work can be avoided by checking sometimes:
2256
2257 $hdl->starttls ("accept");
2258 return if $hdl->destroyed;
2259 $hdl->push_write (...
2260
2261Note that the call to C<push_write> will silently be ignored if the handle
2262has been destroyed, so often you can just ignore the possibility of the
2263handle being destroyed.
2264
2265=cut
2266
2267sub destroyed { 0 }
2268sub AnyEvent::Handle::destroyed::destroyed { 1 }
1695 2269
1696=item AnyEvent::Handle::TLS_CTX 2270=item AnyEvent::Handle::TLS_CTX
1697 2271
1698This function creates and returns the AnyEvent::TLS object used by default 2272This function creates and returns the AnyEvent::TLS object used by default
1699for TLS mode. 2273for TLS mode.
1727 2301
1728It is only safe to "forget" the reference inside EOF or error callbacks, 2302It is only safe to "forget" the reference inside EOF or error callbacks,
1729from within all other callbacks, you need to explicitly call the C<< 2303from within all other callbacks, you need to explicitly call the C<<
1730->destroy >> method. 2304->destroy >> method.
1731 2305
2306=item Why is my C<on_eof> callback never called?
2307
2308Probably because your C<on_error> callback is being called instead: When
2309you have outstanding requests in your read queue, then an EOF is
2310considered an error as you clearly expected some data.
2311
2312To avoid this, make sure you have an empty read queue whenever your handle
2313is supposed to be "idle" (i.e. connection closes are O.K.). You can set
2314an C<on_read> handler that simply pushes the first read requests in the
2315queue.
2316
2317See also the next question, which explains this in a bit more detail.
2318
2319=item How can I serve requests in a loop?
2320
2321Most protocols consist of some setup phase (authentication for example)
2322followed by a request handling phase, where the server waits for requests
2323and handles them, in a loop.
2324
2325There are two important variants: The first (traditional, better) variant
2326handles requests until the server gets some QUIT command, causing it to
2327close the connection first (highly desirable for a busy TCP server). A
2328client dropping the connection is an error, which means this variant can
2329detect an unexpected detection close.
2330
2331To handle this case, always make sure you have a non-empty read queue, by
2332pushing the "read request start" handler on it:
2333
2334 # we assume a request starts with a single line
2335 my @start_request; @start_request = (line => sub {
2336 my ($hdl, $line) = @_;
2337
2338 ... handle request
2339
2340 # push next request read, possibly from a nested callback
2341 $hdl->push_read (@start_request);
2342 });
2343
2344 # auth done, now go into request handling loop
2345 # now push the first @start_request
2346 $hdl->push_read (@start_request);
2347
2348By always having an outstanding C<push_read>, the handle always expects
2349some data and raises the C<EPIPE> error when the connction is dropped
2350unexpectedly.
2351
2352The second variant is a protocol where the client can drop the connection
2353at any time. For TCP, this means that the server machine may run out of
2354sockets easier, and in general, it means you cannot distinguish a protocl
2355failure/client crash from a normal connection close. Nevertheless, these
2356kinds of protocols are common (and sometimes even the best solution to the
2357problem).
2358
2359Having an outstanding read request at all times is possible if you ignore
2360C<EPIPE> errors, but this doesn't help with when the client drops the
2361connection during a request, which would still be an error.
2362
2363A better solution is to push the initial request read in an C<on_read>
2364callback. This avoids an error, as when the server doesn't expect data
2365(i.e. is idly waiting for the next request, an EOF will not raise an
2366error, but simply result in an C<on_eof> callback. It is also a bit slower
2367and simpler:
2368
2369 # auth done, now go into request handling loop
2370 $hdl->on_read (sub {
2371 my ($hdl) = @_;
2372
2373 # called each time we receive data but the read queue is empty
2374 # simply start read the request
2375
2376 $hdl->push_read (line => sub {
2377 my ($hdl, $line) = @_;
2378
2379 ... handle request
2380
2381 # do nothing special when the request has been handled, just
2382 # let the request queue go empty.
2383 });
2384 });
2385
1732=item I get different callback invocations in TLS mode/Why can't I pause 2386=item I get different callback invocations in TLS mode/Why can't I pause
1733reading? 2387reading?
1734 2388
1735Unlike, say, TCP, TLS connections do not consist of two independent 2389Unlike, say, TCP, TLS connections do not consist of two independent
1736communication channels, one for each direction. Or put differently. The 2390communication channels, one for each direction. Or put differently, the
1737read and write directions are not independent of each other: you cannot 2391read and write directions are not independent of each other: you cannot
1738write data unless you are also prepared to read, and vice versa. 2392write data unless you are also prepared to read, and vice versa.
1739 2393
1740This can mean than, in TLS mode, you might get C<on_error> or C<on_eof> 2394This means that, in TLS mode, you might get C<on_error> or C<on_eof>
1741callback invocations when you are not expecting any read data - the reason 2395callback invocations when you are not expecting any read data - the reason
1742is that AnyEvent::Handle always reads in TLS mode. 2396is that AnyEvent::Handle always reads in TLS mode.
1743 2397
1744During the connection, you have to make sure that you always have a 2398During the connection, you have to make sure that you always have a
1745non-empty read-queue, or an C<on_read> watcher. At the end of the 2399non-empty read-queue, or an C<on_read> watcher. At the end of the
1757 $handle->on_eof (undef); 2411 $handle->on_eof (undef);
1758 $handle->on_error (sub { 2412 $handle->on_error (sub {
1759 my $data = delete $_[0]{rbuf}; 2413 my $data = delete $_[0]{rbuf};
1760 }); 2414 });
1761 2415
2416Note that this example removes the C<rbuf> member from the handle object,
2417which is not normally allowed by the API. It is expressly permitted in
2418this case only, as the handle object needs to be destroyed afterwards.
2419
1762The reason to use C<on_error> is that TCP connections, due to latencies 2420The reason to use C<on_error> is that TCP connections, due to latencies
1763and packets loss, might get closed quite violently with an error, when in 2421and packets loss, might get closed quite violently with an error, when in
1764fact, all data has been received. 2422fact all data has been received.
1765 2423
1766It is usually better to use acknowledgements when transferring data, 2424It is usually better to use acknowledgements when transferring data,
1767to make sure the other side hasn't just died and you got the data 2425to make sure the other side hasn't just died and you got the data
1768intact. This is also one reason why so many internet protocols have an 2426intact. This is also one reason why so many internet protocols have an
1769explicit QUIT command. 2427explicit QUIT command.
1776C<low_water_mark> this will be called precisely when all data has been 2434C<low_water_mark> this will be called precisely when all data has been
1777written to the socket: 2435written to the socket:
1778 2436
1779 $handle->push_write (...); 2437 $handle->push_write (...);
1780 $handle->on_drain (sub { 2438 $handle->on_drain (sub {
1781 warn "all data submitted to the kernel\n"; 2439 AE::log debug => "All data submitted to the kernel.";
1782 undef $handle; 2440 undef $handle;
1783 }); 2441 });
1784 2442
1785If you just want to queue some data and then signal EOF to the other side, 2443If you just want to queue some data and then signal EOF to the other side,
1786consider using C<< ->push_shutdown >> instead. 2444consider using C<< ->push_shutdown >> instead.
1787 2445
1788=item I want to contact a TLS/SSL server, I don't care about security. 2446=item I want to contact a TLS/SSL server, I don't care about security.
1789 2447
1790If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS, 2448If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
1791simply connect to it and then create the AnyEvent::Handle with the C<tls> 2449connect to it and then create the AnyEvent::Handle with the C<tls>
1792parameter: 2450parameter:
1793 2451
1794 tcp_connect $host, $port, sub { 2452 tcp_connect $host, $port, sub {
1795 my ($fh) = @_; 2453 my ($fh) = @_;
1796 2454
1870When you have intermediate CA certificates that your clients might not 2528When you have intermediate CA certificates that your clients might not
1871know about, just append them to the C<cert_file>. 2529know about, just append them to the C<cert_file>.
1872 2530
1873=back 2531=back
1874 2532
1875
1876=head1 SUBCLASSING AnyEvent::Handle 2533=head1 SUBCLASSING AnyEvent::Handle
1877 2534
1878In many cases, you might want to subclass AnyEvent::Handle. 2535In many cases, you might want to subclass AnyEvent::Handle.
1879 2536
1880To make this easier, a given version of AnyEvent::Handle uses these 2537To make this easier, a given version of AnyEvent::Handle uses these
1896 2553
1897=item * all members not documented here and not prefixed with an underscore 2554=item * all members not documented here and not prefixed with an underscore
1898are free to use in subclasses. 2555are free to use in subclasses.
1899 2556
1900Of course, new versions of AnyEvent::Handle may introduce more "public" 2557Of course, new versions of AnyEvent::Handle may introduce more "public"
1901member variables, but thats just life, at least it is documented. 2558member variables, but that's just life. At least it is documented.
1902 2559
1903=back 2560=back
1904 2561
1905=head1 AUTHOR 2562=head1 AUTHOR
1906 2563
1907Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 2564Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
1908 2565
1909=cut 2566=cut
1910 2567
19111; # End of AnyEvent::Handle 25681
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