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Revision 1.158 by root, Fri Jul 24 08:40:35 2009 UTC vs.
Revision 1.236 by root, Sat May 12 23:14:29 2012 UTC

1package AnyEvent::Handle;
2
3use Scalar::Util ();
4use Carp ();
5use Errno qw(EAGAIN EINTR);
6
7use AnyEvent (); BEGIN { AnyEvent::common_sense }
8use AnyEvent::Util qw(WSAEWOULDBLOCK);
9
10=head1 NAME 1=head1 NAME
11 2
12AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
13
14=cut
15
16our $VERSION = 4.86;
17 4
18=head1 SYNOPSIS 5=head1 SYNOPSIS
19 6
20 use AnyEvent; 7 use AnyEvent;
21 use AnyEvent::Handle; 8 use AnyEvent::Handle;
24 11
25 my $hdl; $hdl = new AnyEvent::Handle 12 my $hdl; $hdl = new AnyEvent::Handle
26 fh => \*STDIN, 13 fh => \*STDIN,
27 on_error => sub { 14 on_error => sub {
28 my ($hdl, $fatal, $msg) = @_; 15 my ($hdl, $fatal, $msg) = @_;
29 warn "got error $msg\n"; 16 AE::log error => $msg;
30 $hdl->destroy; 17 $hdl->destroy;
31 $cv->send; 18 $cv->send;
32 ); 19 };
33 20
34 # send some request line 21 # send some request line
35 $hdl->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
36 23
37 # read the response line 24 # read the response line
38 $hdl->push_read (line => sub { 25 $hdl->push_read (line => sub {
39 my ($hdl, $line) = @_; 26 my ($hdl, $line) = @_;
40 warn "got line <$line>\n"; 27 say "got line <$line>";
41 $cv->send; 28 $cv->send;
42 }); 29 });
43 30
44 $cv->recv; 31 $cv->recv;
45 32
46=head1 DESCRIPTION 33=head1 DESCRIPTION
47 34
48This 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
49filehandles. For utility functions for doing non-blocking connects and accepts 36stream-based filehandles (sockets, pipes, and other stream things).
50on sockets see L<AnyEvent::Util>.
51 37
52The L<AnyEvent::Intro> tutorial contains some well-documented 38The L<AnyEvent::Intro> tutorial contains some well-documented
53AnyEvent::Handle examples. 39AnyEvent::Handle examples.
54 40
55In the following, when the documentation refers to of "bytes" then this 41In the following, where the documentation refers to "bytes", it means
56means characters. As sysread and syswrite are used for all I/O, their 42characters. As sysread and syswrite are used for all I/O, their
57treatment 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.
58 47
59All callbacks will be invoked with the handle object as their first 48All callbacks will be invoked with the handle object as their first
60argument. 49argument.
61 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
62=head1 METHODS 82=head1 METHODS
63 83
64=over 4 84=over 4
65 85
66=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value... 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
67 87
68The constructor supports these arguments (all as C<< key => value >> pairs). 88The constructor supports these arguments (all as C<< key => value >> pairs).
69 89
70=over 4 90=over 4
71 91
72=item fh => $filehandle [MANDATORY]
73
74#=item fh => $filehandle [C<fh> or C<connect> MANDATORY] 92=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
75 93
76The filehandle this L<AnyEvent::Handle> object will operate on. 94The filehandle this L<AnyEvent::Handle> object will operate on.
77NOTE: The filehandle will be set to non-blocking mode (using 95NOTE: The filehandle will be set to non-blocking mode (using
78C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in 96C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
79that mode. 97that mode.
80 98
81#=item connect => [$host, $service] 99=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
82# 100
83# You have to specify either this parameter, or C<connect>, below.
84#Try to connect to the specified host and service (port), using 101Try to connect to the specified host and service (port), using
85#C<AnyEvent::Socket::tcp_connect>. 102C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
86# 103default C<peername>.
87#When this 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.
88 222
89=item on_eof => $cb->($handle) 223=item on_eof => $cb->($handle)
90 224
91Set 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,
92i.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
100down. 234down.
101 235
102If 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
103set, 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>.
104 238
105=item on_error => $cb->($handle, $fatal, $message)
106
107This is the error callback, which is called when, well, some error
108occured, such as not being able to resolve the hostname, failure to
109connect or a read error.
110
111Some errors are fatal (which is indicated by C<$fatal> being true). On
112fatal errors the handle object will be destroyed (by a call to C<< ->
113destroy >>) after invoking the error callback (which means you are free to
114examine the handle object). Examples of fatal errors are an EOF condition
115with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors.
116
117AnyEvent::Handle tries to find an appropriate error code for you to check
118against, but in some cases (TLS errors), this does not work well. It is
119recommended to always output the C<$message> argument in human-readable
120error messages (it's usually the same as C<"$!">).
121
122Non-fatal errors can be retried by simply returning, but it is recommended
123to simply ignore this parameter and instead abondon the handle object
124when this callback is invoked. Examples of non-fatal errors are timeouts
125C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
126
127On callback entrance, the value of C<$!> contains the operating system
128error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
129C<EPROTO>).
130
131While not mandatory, it is I<highly> recommended to set this callback, as
132you will not be notified of errors otherwise. The default simply calls
133C<croak>.
134
135=item on_read => $cb->($handle)
136
137This sets the default read callback, which is called when data arrives
138and no read request is in the queue (unlike read queue callbacks, this
139callback will only be called when at least one octet of data is in the
140read buffer).
141
142To access (and remove data from) the read buffer, use the C<< ->rbuf >>
143method or access the C<< $handle->{rbuf} >> member directly. Note that you
144must not enlarge or modify the read buffer, you can only remove data at
145the beginning from it.
146
147When an EOF condition is detected then AnyEvent::Handle will first try to
148feed all the remaining data to the queued callbacks and C<on_read> before
149calling the C<on_eof> callback. If no progress can be made, then a fatal
150error will be raised (with C<$!> set to C<EPIPE>).
151
152Note that, unlike requests in the read queue, an C<on_read> callback
153doesn't mean you I<require> some data: if there is an EOF and there
154are outstanding read requests then an error will be flagged. With an
155C<on_read> callback, the C<on_eof> callback will be invoked.
156
157=item on_drain => $cb->($handle) 239=item on_drain => $cb->($handle)
158 240
159This 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
160(or when the callback is set and the buffer is empty already). 242empty (and immediately when the handle object is created).
161 243
162To append to the write buffer, use the C<< ->push_write >> method. 244To append to the write buffer, use the C<< ->push_write >> method.
163 245
164This 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
165into 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
167memory 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
168the file when the write queue becomes empty. 250the file when the write queue becomes empty.
169 251
170=item timeout => $fractional_seconds 252=item timeout => $fractional_seconds
171 253
254=item rtimeout => $fractional_seconds
255
256=item wtimeout => $fractional_seconds
257
172If non-zero, then this enables an "inactivity" timeout: whenever this many 258If non-zero, then these enables an "inactivity" timeout: whenever this
173seconds pass without a successful read or write on the underlying file 259many seconds pass without a successful read or write on the underlying
174handle, 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
175missing, 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).
176 263
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
177Note 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
178any outstanding read or write requests: If you plan to keep the connection 272outstanding read or write requests: If you plan to keep the connection
179idle then you should disable the timout temporarily or ignore the timeout 273idle then you should disable the timeout temporarily or ignore the
180in the C<on_timeout> callback, in which case AnyEvent::Handle will simply 274timeout in the corresponding C<on_timeout> callback, in which case
181restart the timeout. 275AnyEvent::Handle will simply restart the timeout.
182 276
183Zero (the default) disables this timeout. 277Zero (the default) disables the corresponding timeout.
184 278
185=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)
186 284
187Called whenever the inactivity timeout passes. If you return from this 285Called whenever the inactivity timeout passes. If you return from this
188callback, 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,
189so this condition is not fatal in any way. 287so this condition is not fatal in any way.
190 288
198be 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
199(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
200amount 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
201isn't finished). 299isn't finished).
202 300
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
203=item autocork => <boolean> 316=item autocork => <boolean>
204 317
205When disabled (the default), then C<push_write> will try to immediately 318When disabled (the default), C<push_write> will try to immediately
206write 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
207a 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
208be inefficient if you write multiple small chunks (on the wire, this 321be inefficient if you write multiple small chunks (on the wire, this
209disadvantage is usually avoided by your kernel's nagle algorithm, see 322disadvantage is usually avoided by your kernel's nagle algorithm, see
210C<no_delay>, but this option can save costly syscalls). 323C<no_delay>, but this option can save costly syscalls).
211 324
212When enabled, then writes will always be queued till the next event loop 325When enabled, writes will always be queued till the next event loop
213iteration. This is efficient when you do many small writes per iteration, 326iteration. This is efficient when you do many small writes per iteration,
214but 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
215the write buffer often is full). It also increases write latency. 328the write buffer often is full). It also increases write latency.
216 329
217=item no_delay => <boolean> 330=item no_delay => <boolean>
221the Nagle algorithm, and usually it is beneficial. 334the Nagle algorithm, and usually it is beneficial.
222 335
223In 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
224accomplishd by setting this option to a true value. 337accomplishd by setting this option to a true value.
225 338
226The default is your opertaing system's default behaviour (most likely 339The default is your operating system's default behaviour (most likely
227enabled), 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.
228 373
229=item read_size => <bytes> 374=item read_size => <bytes>
230 375
231The default read block size (the amount of bytes this module will 376The initial read block size, the number of bytes this module will try
232try to read during each loop iteration, which affects memory 377to read during each loop iteration. Each handle object will consume
233requirements). 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.
234 388
235=item low_water_mark => <bytes> 389=item low_water_mark => <bytes>
236 390
237Sets 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
238buffer: 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
239considered empty. 393considered empty.
240 394
241Sometimes it can be beneficial (for performance reasons) to add data to 395Sometimes it can be beneficial (for performance reasons) to add data to
242the 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
243the operating system kernel usually buffers data as well, so the default 397the operating system kernel usually buffers data as well, so the default
244is good in almost all cases. 398is good in almost all cases.
245 399
246=item linger => <seconds> 400=item linger => <seconds>
247 401
248If non-zero (default: C<3600>), then the destructor of the 402If this is non-zero (default: C<3600>), the destructor of the
249AnyEvent::Handle object will check whether there is still outstanding 403AnyEvent::Handle object will check whether there is still outstanding
250write 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
251socket. No errors will be reported (this mostly matches how the operating 405socket. No errors will be reported (this mostly matches how the operating
252system treats outstanding data at socket close time). 406system treats outstanding data at socket close time).
253 407
260A string used to identify the remote site - usually the DNS hostname 414A string used to identify the remote site - usually the DNS hostname
261(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.
262 416
263Apart 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
264peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This 418peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
265verification will be skipped when C<peername> is not specified or 419verification will be skipped when C<peername> is not specified or is
266C<undef>. 420C<undef>.
267 421
268=item tls => "accept" | "connect" | Net::SSLeay::SSL object 422=item tls => "accept" | "connect" | Net::SSLeay::SSL object
269 423
270When this parameter is given, it enables TLS (SSL) mode, that means 424When this parameter is given, it enables TLS (SSL) mode, that means
271AnyEvent 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
272established and will transparently encrypt/decrypt data afterwards. 426established and will transparently encrypt/decrypt data afterwards.
273 427
274All TLS protocol errors will be signalled as C<EPROTO>, with an 428All TLS protocol errors will be signalled as C<EPROTO>, with an
275appropriate error message. 429appropriate error message.
276 430
277TLS mode requires Net::SSLeay to be installed (it will be loaded 431TLS mode requires Net::SSLeay to be installed (it will be loaded
278automatically 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
279have 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
280to 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.
281 436
282Unlike 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
283C<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>
284mode. 439mode.
285 440
296B<IMPORTANT:> since Net::SSLeay "objects" are really only integers, 451B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
297passing 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
298happens 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
299segmentation fault. 454segmentation fault.
300 455
301See 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.
302 457
303=item tls_ctx => $anyevent_tls 458=item tls_ctx => $anyevent_tls
304 459
305Use 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
306(unless a connection object was specified directly). If this parameter is 461(unless a connection object was specified directly). If this
307missing, 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>.
308 464
309Instead 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
310=> 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
311new TLS context object. 467new TLS context object.
312 468
321 477
322TLS 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
323callback 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>.
324 480
325Without this callback, handshake failures lead to C<on_error> being 481Without this callback, handshake failures lead to C<on_error> being
326called, as normal. 482called as usual.
327 483
328Note 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
329need 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
330then call C<< ->starttls >> again. 486then call C<< ->starttls >> again.
331 487
332=item on_stoptls => $cb->($handle) 488=item on_stoptls => $cb->($handle)
333 489
359 515
360sub new { 516sub new {
361 my $class = shift; 517 my $class = shift;
362 my $self = bless { @_ }, $class; 518 my $self = bless { @_ }, $class;
363 519
364 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 520 if ($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;
365 591
366 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 592 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
367 593
594 $self->{_activity} =
595 $self->{_ractivity} =
368 $self->{_activity} = AnyEvent->now; 596 $self->{_wactivity} = AE::now;
369 $self->_timeout;
370 597
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
371 $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};
372 608
609 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
610
373 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}) 611 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
374 if $self->{tls}; 612 if $self->{tls};
375 613
376 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 614 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
377 615
378 $self->start_read 616 $self->start_read
379 if $self->{on_read}; 617 if $self->{on_read} || @{ $self->{_queue} };
380 618
381 $self->{fh} && $self 619 $self->_drain_wbuf;
382} 620}
383
384#sub _shutdown {
385# my ($self) = @_;
386#
387# delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
388# $self->{_eof} = 1; # tell starttls et. al to stop trying
389#
390# &_freetls;
391#}
392 621
393sub _error { 622sub _error {
394 my ($self, $errno, $fatal, $message) = @_; 623 my ($self, $errno, $fatal, $message) = @_;
395 624
396 $! = $errno; 625 $! = $errno;
397 $message ||= "$!"; 626 $message ||= "$!";
398 627
399 if ($self->{on_error}) { 628 if ($self->{on_error}) {
400 $self->{on_error}($self, $fatal, $message); 629 $self->{on_error}($self, $fatal, $message);
401 $self->destroy if $fatal; 630 $self->destroy if $fatal;
402 } elsif ($self->{fh}) { 631 } elsif ($self->{fh} || $self->{connect}) {
403 $self->destroy; 632 $self->destroy;
404 Carp::croak "AnyEvent::Handle uncaught error: $message"; 633 Carp::croak "AnyEvent::Handle uncaught error: $message";
405 } 634 }
406} 635}
407 636
433 $_[0]{on_eof} = $_[1]; 662 $_[0]{on_eof} = $_[1];
434} 663}
435 664
436=item $handle->on_timeout ($cb) 665=item $handle->on_timeout ($cb)
437 666
438Replace the current C<on_timeout> callback, or disables the callback (but 667=item $handle->on_rtimeout ($cb)
439not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
440argument and method.
441 668
442=cut 669=item $handle->on_wtimeout ($cb)
443 670
444sub on_timeout { 671Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
445 $_[0]{on_timeout} = $_[1]; 672callback, or disables the callback (but not the timeout) if C<$cb> =
446} 673C<undef>. See the C<timeout> constructor argument and method.
674
675=cut
676
677# see below
447 678
448=item $handle->autocork ($boolean) 679=item $handle->autocork ($boolean)
449 680
450Enables or disables the current autocork behaviour (see C<autocork> 681Enables or disables the current autocork behaviour (see C<autocork>
451constructor argument). Changes will only take effect on the next write. 682constructor argument). Changes will only take effect on the next write.
464=cut 695=cut
465 696
466sub no_delay { 697sub no_delay {
467 $_[0]{no_delay} = $_[1]; 698 $_[0]{no_delay} = $_[1];
468 699
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
469 eval { 714 eval {
470 local $SIG{__DIE__}; 715 local $SIG{__DIE__};
471 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};
472 }; 752 };
473} 753}
474 754
475=item $handle->on_starttls ($cb) 755=item $handle->on_starttls ($cb)
476 756
486 766
487Replace 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).
488 768
489=cut 769=cut
490 770
491sub on_starttls { 771sub on_stoptls {
492 $_[0]{on_stoptls} = $_[1]; 772 $_[0]{on_stoptls} = $_[1];
493} 773}
494 774
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
495############################################################################# 793#############################################################################
496 794
497=item $handle->timeout ($seconds) 795=item $handle->timeout ($seconds)
498 796
797=item $handle->rtimeout ($seconds)
798
799=item $handle->wtimeout ($seconds)
800
499Configures (or disables) the inactivity timeout. 801Configures (or disables) the inactivity timeout.
500 802
501=cut 803The timeout will be checked instantly, so this method might destroy the
804handle before it returns.
502 805
503sub 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 {
504 my ($self, $timeout) = @_; 830 my ($self, $new_value) = @_;
505 831
832 $new_value >= 0
833 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
834
506 $self->{timeout} = $timeout; 835 $self->{$timeout} = $new_value;
507 $self->_timeout; 836 delete $self->{$tw}; &$cb;
508} 837 };
509 838
839 *{"${dir}timeout_reset"} = sub {
840 $_[0]{$activity} = AE::now;
841 };
842
843 # main workhorse:
510# reset the timeout watcher, as neccessary 844 # reset the timeout watcher, as neccessary
511# also check for time-outs 845 # also check for time-outs
512sub _timeout { 846 $cb = sub {
513 my ($self) = @_; 847 my ($self) = @_;
514 848
515 if ($self->{timeout}) { 849 if ($self->{$timeout} && $self->{fh}) {
516 my $NOW = AnyEvent->now; 850 my $NOW = AE::now;
517 851
518 # when would the timeout trigger? 852 # when would the timeout trigger?
519 my $after = $self->{_activity} + $self->{timeout} - $NOW; 853 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
520 854
521 # now or in the past already? 855 # now or in the past already?
522 if ($after <= 0) { 856 if ($after <= 0) {
523 $self->{_activity} = $NOW; 857 $self->{$activity} = $NOW;
524 858
525 if ($self->{on_timeout}) { 859 if ($self->{$on_timeout}) {
526 $self->{on_timeout}($self); 860 $self->{$on_timeout}($self);
527 } else { 861 } else {
528 $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};
529 } 870 }
530 871
531 # callback could have changed timeout value, optimise 872 Scalar::Util::weaken $self;
532 return unless $self->{timeout}; 873 return unless $self; # ->error could have destroyed $self
533 874
534 # calculate new after 875 $self->{$tw} ||= AE::timer $after, 0, sub {
535 $after = $self->{timeout}; 876 delete $self->{$tw};
877 $cb->($self);
878 };
879 } else {
880 delete $self->{$tw};
536 } 881 }
537
538 Scalar::Util::weaken $self;
539 return unless $self; # ->error could have destroyed $self
540
541 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
542 delete $self->{_tw};
543 $self->_timeout;
544 });
545 } else {
546 delete $self->{_tw};
547 } 882 }
548} 883}
549 884
550############################################################################# 885#############################################################################
551 886
558 893
559The 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
560AnyEvent::Handle will automatically try to get rid of it for you. 895AnyEvent::Handle will automatically try to get rid of it for you.
561 896
562When 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
563water mark, the C<on_drain> callback will be invoked. 898water mark, the C<on_drain> callback will be invoked once.
564 899
565=over 4 900=over 4
566 901
567=item $handle->on_drain ($cb) 902=item $handle->on_drain ($cb)
568 903
569Sets 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
570C<on_drain> in the constructor). 905C<on_drain> in the constructor).
571 906
907This method may invoke callbacks (and therefore the handle might be
908destroyed after it returns).
909
572=cut 910=cut
573 911
574sub on_drain { 912sub on_drain {
575 my ($self, $cb) = @_; 913 my ($self, $cb) = @_;
576 914
580 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});
581} 919}
582 920
583=item $handle->push_write ($data) 921=item $handle->push_write ($data)
584 922
585Queues 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
586want (only limited by the available memory), as C<AnyEvent::Handle> 924you want (only limited by the available memory and C<wbuf_max>), as
587buffers 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).
588 929
589=cut 930=cut
590 931
591sub _drain_wbuf { 932sub _drain_wbuf {
592 my ($self) = @_; 933 my ($self) = @_;
599 my $len = syswrite $self->{fh}, $self->{wbuf}; 940 my $len = syswrite $self->{fh}, $self->{wbuf};
600 941
601 if (defined $len) { 942 if (defined $len) {
602 substr $self->{wbuf}, 0, $len, ""; 943 substr $self->{wbuf}, 0, $len, "";
603 944
604 $self->{_activity} = AnyEvent->now; 945 $self->{_activity} = $self->{_wactivity} = AE::now;
605 946
606 $self->{on_drain}($self) 947 $self->{on_drain}($self)
607 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})
608 && $self->{on_drain}; 949 && $self->{on_drain};
609 950
615 956
616 # try to write data immediately 957 # try to write data immediately
617 $cb->() unless $self->{autocork}; 958 $cb->() unless $self->{autocork};
618 959
619 # if still data left in wbuf, we need to poll 960 # if still data left in wbuf, we need to poll
620 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 961 $self->{_ww} = AE::io $self->{fh}, 1, $cb
621 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 }
622 }; 970 };
623} 971}
624 972
625our %WH; 973our %WH;
626 974
975# deprecated
627sub register_write_type($$) { 976sub register_write_type($$) {
628 $WH{$_[0]} = $_[1]; 977 $WH{$_[0]} = $_[1];
629} 978}
630 979
631sub push_write { 980sub push_write {
632 my $self = shift; 981 my $self = shift;
633 982
634 if (@_ > 1) { 983 if (@_ > 1) {
635 my $type = shift; 984 my $type = shift;
636 985
986 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
637 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 987 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
638 ->($self, @_); 988 ->($self, @_);
639 } 989 }
640 990
991 # we downgrade here to avoid hard-to-track-down bugs,
992 # and diagnose the problem earlier and better.
993
641 if ($self->{tls}) { 994 if ($self->{tls}) {
642 $self->{_tls_wbuf} .= $_[0]; 995 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
643 996 &_dotls ($self) if $self->{fh};
644 &_dotls ($self);
645 } else { 997 } else {
646 $self->{wbuf} .= $_[0]; 998 utf8::downgrade $self->{wbuf} .= $_[0];
647 $self->_drain_wbuf; 999 $self->_drain_wbuf if $self->{fh};
648 } 1000 }
649} 1001}
650 1002
651=item $handle->push_write (type => @args) 1003=item $handle->push_write (type => @args)
652 1004
653Instead of formatting your data yourself, you can also let this module do 1005Instead of formatting your data yourself, you can also let this module
654the job by specifying a type and type-specific arguments. 1006do the job by specifying a type and type-specific arguments. You
1007can also specify the (fully qualified) name of a package, in which
1008case AnyEvent tries to load the package and then expects to find the
1009C<anyevent_write_type> function inside (see "custom write types", below).
655 1010
656Predefined types are (if you have ideas for additional types, feel free to 1011Predefined types are (if you have ideas for additional types, feel free to
657drop by and tell us): 1012drop by and tell us):
658 1013
659=over 4 1014=over 4
716Other languages could read single lines terminated by a newline and pass 1071Other languages could read single lines terminated by a newline and pass
717this line into their JSON decoder of choice. 1072this line into their JSON decoder of choice.
718 1073
719=cut 1074=cut
720 1075
1076sub json_coder() {
1077 eval { require JSON::XS; JSON::XS->new->utf8 }
1078 || do { require JSON; JSON->new->utf8 }
1079}
1080
721register_write_type json => sub { 1081register_write_type json => sub {
722 my ($self, $ref) = @_; 1082 my ($self, $ref) = @_;
723 1083
724 require JSON; 1084 my $json = $self->{json} ||= json_coder;
725 1085
726 $self->{json} ? $self->{json}->encode ($ref) 1086 $json->encode ($ref)
727 : JSON::encode_json ($ref)
728}; 1087};
729 1088
730=item storable => $reference 1089=item storable => $reference
731 1090
732Freezes the given reference using L<Storable> and writes it to the 1091Freezes the given reference using L<Storable> and writes it to the
735=cut 1094=cut
736 1095
737register_write_type storable => sub { 1096register_write_type storable => sub {
738 my ($self, $ref) = @_; 1097 my ($self, $ref) = @_;
739 1098
740 require Storable; 1099 require Storable unless $Storable::VERSION;
741 1100
742 pack "w/a*", Storable::nfreeze ($ref) 1101 pack "w/a*", Storable::nfreeze ($ref)
743}; 1102};
744 1103
745=back 1104=back
750before 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
751C<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
752C<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
753replaces the C<on_drain> callback with: 1112replaces the C<on_drain> callback with:
754 1113
755 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown 1114 sub { shutdown $_[0]{fh}, 1 }
756 1115
757This simply shuts down the write side and signals an EOF condition to the 1116This simply shuts down the write side and signals an EOF condition to the
758the peer. 1117the peer.
759 1118
760You can rely on the normal read queue and C<on_eof> handling 1119You can rely on the normal read queue and C<on_eof> handling
761afterwards. This is the cleanest way to close a connection. 1120afterwards. This is the cleanest way to close a connection.
762 1121
1122This method may invoke callbacks (and therefore the handle might be
1123destroyed after it returns).
1124
763=cut 1125=cut
764 1126
765sub push_shutdown { 1127sub push_shutdown {
766 my ($self) = @_; 1128 my ($self) = @_;
767 1129
768 delete $self->{low_water_mark}; 1130 delete $self->{low_water_mark};
769 $self->on_drain (sub { shutdown $_[0]{fh}, 1 }); 1131 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
770} 1132}
771 1133
772=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1134=item custom write types - Package::anyevent_write_type $handle, @args
773 1135
774This 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
775Whenever 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
776reference with the handle object and the remaining arguments. 1143the handle object and the remaining arguments.
777 1144
778The 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
779be 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.
780 1148
781Note 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
782global, 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 }
783 1165
784=cut 1166=cut
785 1167
786############################################################################# 1168#############################################################################
787 1169
796ways, 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
797a queue. 1179a queue.
798 1180
799In 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
800new 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
801enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna 1183enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
802leave the data there if you want to accumulate more (e.g. when only a 1184leave the data there if you want to accumulate more (e.g. when only a
803partial message has been received so far). 1185partial message has been received so far), or change the read queue with
1186e.g. C<push_read>.
804 1187
805In the more complex case, you want to queue multiple callbacks. In this 1188In the more complex case, you want to queue multiple callbacks. In this
806case, AnyEvent::Handle will call the first queued callback each time new 1189case, AnyEvent::Handle will call the first queued callback each time new
807data arrives (also the first time it is queued) and removes it when it has 1190data arrives (also the first time it is queued) and remove it when it has
808done its job (see C<push_read>, below). 1191done its job (see C<push_read>, below).
809 1192
810This way you can, for example, push three line-reads, followed by reading 1193This way you can, for example, push three line-reads, followed by reading
811a chunk of data, and AnyEvent::Handle will execute them in order. 1194a chunk of data, and AnyEvent::Handle will execute them in order.
812 1195
869=cut 1252=cut
870 1253
871sub _drain_rbuf { 1254sub _drain_rbuf {
872 my ($self) = @_; 1255 my ($self) = @_;
873 1256
1257 # avoid recursion
1258 return if $self->{_skip_drain_rbuf};
874 local $self->{_in_drain} = 1; 1259 local $self->{_skip_drain_rbuf} = 1;
875
876 if (
877 defined $self->{rbuf_max}
878 && $self->{rbuf_max} < length $self->{rbuf}
879 ) {
880 $self->_error (Errno::ENOSPC, 1), return;
881 }
882 1260
883 while () { 1261 while () {
884 # 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
885 # 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.
886 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf}; 1264 $self->{rbuf} .= delete $self->{_tls_rbuf}
1265 if exists $self->{_tls_rbuf};
887 1266
888 my $len = length $self->{rbuf}; 1267 my $len = length $self->{rbuf};
889 1268
890 if (my $cb = shift @{ $self->{_queue} }) { 1269 if (my $cb = shift @{ $self->{_queue} }) {
891 unless ($cb->($self)) { 1270 unless ($cb->($self)) {
892 if ($self->{_eof}) { 1271 # no progress can be made
893 # no progress can be made (not enough data and no data forthcoming) 1272 # (not enough data and no data forthcoming)
894 $self->_error (Errno::EPIPE, 1), return; 1273 $self->_error (Errno::EPIPE, 1), return
895 } 1274 if $self->{_eof};
896 1275
897 unshift @{ $self->{_queue} }, $cb; 1276 unshift @{ $self->{_queue} }, $cb;
898 last; 1277 last;
899 } 1278 }
900 } elsif ($self->{on_read}) { 1279 } elsif ($self->{on_read}) {
920 last; 1299 last;
921 } 1300 }
922 } 1301 }
923 1302
924 if ($self->{_eof}) { 1303 if ($self->{_eof}) {
925 if ($self->{on_eof}) { 1304 $self->{on_eof}
926 $self->{on_eof}($self) 1305 ? $self->{on_eof}($self)
927 } else {
928 $self->_error (0, 1, "Unexpected end-of-file"); 1306 : $self->_error (0, 1, "Unexpected end-of-file");
929 } 1307
1308 return;
1309 }
1310
1311 if (
1312 defined $self->{rbuf_max}
1313 && $self->{rbuf_max} < length $self->{rbuf}
1314 ) {
1315 $self->_error (Errno::ENOSPC, 1), return;
930 } 1316 }
931 1317
932 # may need to restart read watcher 1318 # may need to restart read watcher
933 unless ($self->{_rw}) { 1319 unless ($self->{_rw}) {
934 $self->start_read 1320 $self->start_read
940 1326
941This replaces the currently set C<on_read> callback, or clears it (when 1327This replaces the currently set C<on_read> callback, or clears it (when
942the new callback is C<undef>). See the description of C<on_read> in the 1328the new callback is C<undef>). See the description of C<on_read> in the
943constructor. 1329constructor.
944 1330
1331This method may invoke callbacks (and therefore the handle might be
1332destroyed after it returns).
1333
945=cut 1334=cut
946 1335
947sub on_read { 1336sub on_read {
948 my ($self, $cb) = @_; 1337 my ($self, $cb) = @_;
949 1338
950 $self->{on_read} = $cb; 1339 $self->{on_read} = $cb;
951 $self->_drain_rbuf if $cb && !$self->{_in_drain}; 1340 $self->_drain_rbuf if $cb;
952} 1341}
953 1342
954=item $handle->rbuf 1343=item $handle->rbuf
955 1344
956Returns 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).
957 1348
958You can access the read buffer directly as the C<< ->{rbuf} >> 1349The only operation allowed on the read buffer (apart from looking at it)
959member, if you want. However, the only operation allowed on the 1350is removing data from its beginning. Otherwise modifying or appending to
960read buffer (apart from looking at it) is removing data from its 1351it is not allowed and will lead to hard-to-track-down bugs.
961beginning. Otherwise modifying or appending to it is not allowed and will
962lead to hard-to-track-down bugs.
963 1352
964NOTE: 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>
965C<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
966automatically 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.
967 1357
968=cut 1358=cut
969 1359
970sub rbuf : lvalue { 1360sub rbuf : lvalue {
971 $_[0]{rbuf} 1361 $_[0]{rbuf}
988 1378
989If 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
990interested 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
991true, it will be removed from the queue. 1381true, it will be removed from the queue.
992 1382
1383These methods may invoke callbacks (and therefore the handle might be
1384destroyed after it returns).
1385
993=cut 1386=cut
994 1387
995our %RH; 1388our %RH;
996 1389
997sub register_read_type($$) { 1390sub register_read_type($$) {
1003 my $cb = pop; 1396 my $cb = pop;
1004 1397
1005 if (@_) { 1398 if (@_) {
1006 my $type = shift; 1399 my $type = shift;
1007 1400
1401 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1008 $cb = ($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")
1009 ->($self, $cb, @_); 1403 ->($self, $cb, @_);
1010 } 1404 }
1011 1405
1012 push @{ $self->{_queue} }, $cb; 1406 push @{ $self->{_queue} }, $cb;
1013 $self->_drain_rbuf unless $self->{_in_drain}; 1407 $self->_drain_rbuf;
1014} 1408}
1015 1409
1016sub unshift_read { 1410sub unshift_read {
1017 my $self = shift; 1411 my $self = shift;
1018 my $cb = pop; 1412 my $cb = pop;
1019 1413
1020 if (@_) { 1414 if (@_) {
1021 my $type = shift; 1415 my $type = shift;
1022 1416
1417 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1023 $cb = ($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")
1024 ->($self, $cb, @_); 1419 ->($self, $cb, @_);
1025 } 1420 }
1026 1421
1027
1028 unshift @{ $self->{_queue} }, $cb; 1422 unshift @{ $self->{_queue} }, $cb;
1029 $self->_drain_rbuf unless $self->{_in_drain}; 1423 $self->_drain_rbuf;
1030} 1424}
1031 1425
1032=item $handle->push_read (type => @args, $cb) 1426=item $handle->push_read (type => @args, $cb)
1033 1427
1034=item $handle->unshift_read (type => @args, $cb) 1428=item $handle->unshift_read (type => @args, $cb)
1035 1429
1036Instead 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
1037between a number of predefined parsing formats, for chunks of data, lines 1431between a number of predefined parsing formats, for chunks of data, lines
1038etc. 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).
1039 1435
1040Predefined 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
1041drop by and tell us): 1437drop by and tell us):
1042 1438
1043=over 4 1439=over 4
1049data. 1445data.
1050 1446
1051Example: read 2 bytes. 1447Example: read 2 bytes.
1052 1448
1053 $handle->push_read (chunk => 2, sub { 1449 $handle->push_read (chunk => 2, sub {
1054 warn "yay ", unpack "H*", $_[1]; 1450 say "yay " . unpack "H*", $_[1];
1055 }); 1451 });
1056 1452
1057=cut 1453=cut
1058 1454
1059register_read_type chunk => sub { 1455register_read_type chunk => sub {
1093 if (@_ < 3) { 1489 if (@_ < 3) {
1094 # 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
1095 sub { 1491 sub {
1096 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return; 1492 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1097 1493
1098 $cb->($_[0], $1, $2); 1494 $cb->($_[0], "$1", "$2");
1099 1 1495 1
1100 } 1496 }
1101 } else { 1497 } else {
1102 $eol = quotemeta $eol unless ref $eol; 1498 $eol = quotemeta $eol unless ref $eol;
1103 $eol = qr|^(.*?)($eol)|s; 1499 $eol = qr|^(.*?)($eol)|s;
1104 1500
1105 sub { 1501 sub {
1106 $_[0]{rbuf} =~ s/$eol// or return; 1502 $_[0]{rbuf} =~ s/$eol// or return;
1107 1503
1108 $cb->($_[0], $1, $2); 1504 $cb->($_[0], "$1", "$2");
1109 1 1505 1
1110 } 1506 }
1111 } 1507 }
1112}; 1508};
1113 1509
1135the receive buffer when neither C<$accept> nor C<$reject> match, 1531the receive buffer when neither C<$accept> nor C<$reject> match,
1136and everything preceding and including the match will be accepted 1532and everything preceding and including the match will be accepted
1137unconditionally. This is useful to skip large amounts of data that you 1533unconditionally. This is useful to skip large amounts of data that you
1138know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1534know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1139have to start matching from the beginning. This is purely an optimisation 1535have to start matching from the beginning. This is purely an optimisation
1140and 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.
1141 1537
1142Example: 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
1143expect 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
1144a 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
1145it 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
1146required for the accept regex. 1542required for the accept regex.
1147 1543
1148 $handle->push_read (regex => 1544 $handle->push_read (regex =>
1161 1557
1162 sub { 1558 sub {
1163 # accept 1559 # accept
1164 if ($$rbuf =~ $accept) { 1560 if ($$rbuf =~ $accept) {
1165 $data .= substr $$rbuf, 0, $+[0], ""; 1561 $data .= substr $$rbuf, 0, $+[0], "";
1166 $cb->($self, $data); 1562 $cb->($_[0], $data);
1167 return 1; 1563 return 1;
1168 } 1564 }
1169 1565
1170 # reject 1566 # reject
1171 if ($reject && $$rbuf =~ $reject) { 1567 if ($reject && $$rbuf =~ $reject) {
1172 $self->_error (Errno::EBADMSG); 1568 $_[0]->_error (Errno::EBADMSG);
1173 } 1569 }
1174 1570
1175 # skip 1571 # skip
1176 if ($skip && $$rbuf =~ $skip) { 1572 if ($skip && $$rbuf =~ $skip) {
1177 $data .= substr $$rbuf, 0, $+[0], ""; 1573 $data .= substr $$rbuf, 0, $+[0], "";
1193 my ($self, $cb) = @_; 1589 my ($self, $cb) = @_;
1194 1590
1195 sub { 1591 sub {
1196 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1592 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1197 if ($_[0]{rbuf} =~ /[^0-9]/) { 1593 if ($_[0]{rbuf} =~ /[^0-9]/) {
1198 $self->_error (Errno::EBADMSG); 1594 $_[0]->_error (Errno::EBADMSG);
1199 } 1595 }
1200 return; 1596 return;
1201 } 1597 }
1202 1598
1203 my $len = $1; 1599 my $len = $1;
1204 1600
1205 $self->unshift_read (chunk => $len, sub { 1601 $_[0]->unshift_read (chunk => $len, sub {
1206 my $string = $_[1]; 1602 my $string = $_[1];
1207 $_[0]->unshift_read (chunk => 1, sub { 1603 $_[0]->unshift_read (chunk => 1, sub {
1208 if ($_[1] eq ",") { 1604 if ($_[1] eq ",") {
1209 $cb->($_[0], $string); 1605 $cb->($_[0], $string);
1210 } else { 1606 } else {
1211 $self->_error (Errno::EBADMSG); 1607 $_[0]->_error (Errno::EBADMSG);
1212 } 1608 }
1213 }); 1609 });
1214 }); 1610 });
1215 1611
1216 1 1612 1
1283=cut 1679=cut
1284 1680
1285register_read_type json => sub { 1681register_read_type json => sub {
1286 my ($self, $cb) = @_; 1682 my ($self, $cb) = @_;
1287 1683
1288 my $json = $self->{json} ||= 1684 my $json = $self->{json} ||= json_coder;
1289 eval { require JSON::XS; JSON::XS->new->utf8 }
1290 || do { require JSON; JSON->new->utf8 };
1291 1685
1292 my $data; 1686 my $data;
1293 my $rbuf = \$self->{rbuf}; 1687 my $rbuf = \$self->{rbuf};
1294 1688
1295 sub { 1689 sub {
1296 my $ref = eval { $json->incr_parse ($self->{rbuf}) }; 1690 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1297 1691
1298 if ($ref) { 1692 if ($ref) {
1299 $self->{rbuf} = $json->incr_text; 1693 $_[0]{rbuf} = $json->incr_text;
1300 $json->incr_text = ""; 1694 $json->incr_text = "";
1301 $cb->($self, $ref); 1695 $cb->($_[0], $ref);
1302 1696
1303 1 1697 1
1304 } elsif ($@) { 1698 } elsif ($@) {
1305 # error case 1699 # error case
1306 $json->incr_skip; 1700 $json->incr_skip;
1307 1701
1308 $self->{rbuf} = $json->incr_text; 1702 $_[0]{rbuf} = $json->incr_text;
1309 $json->incr_text = ""; 1703 $json->incr_text = "";
1310 1704
1311 $self->_error (Errno::EBADMSG); 1705 $_[0]->_error (Errno::EBADMSG);
1312 1706
1313 () 1707 ()
1314 } else { 1708 } else {
1315 $self->{rbuf} = ""; 1709 $_[0]{rbuf} = "";
1316 1710
1317 () 1711 ()
1318 } 1712 }
1319 } 1713 }
1320}; 1714};
1330=cut 1724=cut
1331 1725
1332register_read_type storable => sub { 1726register_read_type storable => sub {
1333 my ($self, $cb) = @_; 1727 my ($self, $cb) = @_;
1334 1728
1335 require Storable; 1729 require Storable unless $Storable::VERSION;
1336 1730
1337 sub { 1731 sub {
1338 # 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
1339 defined (my $len = eval { unpack "w", $_[0]{rbuf} }) 1733 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1340 or return; 1734 or return;
1343 1737
1344 # bypass unshift if we already have the remaining chunk 1738 # bypass unshift if we already have the remaining chunk
1345 if ($format + $len <= length $_[0]{rbuf}) { 1739 if ($format + $len <= length $_[0]{rbuf}) {
1346 my $data = substr $_[0]{rbuf}, $format, $len; 1740 my $data = substr $_[0]{rbuf}, $format, $len;
1347 substr $_[0]{rbuf}, 0, $format + $len, ""; 1741 substr $_[0]{rbuf}, 0, $format + $len, "";
1742
1348 $cb->($_[0], Storable::thaw ($data)); 1743 eval { $cb->($_[0], Storable::thaw ($data)); 1 }
1744 or return $_[0]->_error (Errno::EBADMSG);
1349 } else { 1745 } else {
1350 # remove prefix 1746 # remove prefix
1351 substr $_[0]{rbuf}, 0, $format, ""; 1747 substr $_[0]{rbuf}, 0, $format, "";
1352 1748
1353 # read remaining chunk 1749 # read remaining chunk
1354 $_[0]->unshift_read (chunk => $len, sub { 1750 $_[0]->unshift_read (chunk => $len, sub {
1355 if (my $ref = eval { Storable::thaw ($_[1]) }) { 1751 eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1356 $cb->($_[0], $ref);
1357 } else {
1358 $self->_error (Errno::EBADMSG); 1752 or $_[0]->_error (Errno::EBADMSG);
1359 }
1360 }); 1753 });
1361 } 1754 }
1362 1755
1363 1 1756 1
1364 } 1757 }
1365}; 1758};
1366 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
1367=back 1846=back
1368 1847
1369=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1848=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1370 1849
1371This function (not method) lets you add your own types to C<push_read>. 1850Instead of one of the predefined types, you can also specify the name
1851of a package. AnyEvent will try to load the package and then expects to
1852find a function named C<anyevent_read_type> inside. If it isn't found, it
1853progressively tries to load the parent package until it either finds the
1854function (good) or runs out of packages (bad).
1372 1855
1373Whenever the given C<type> is used, C<push_read> will invoke the code 1856Whenever this type is used, C<push_read> will invoke the function with the
1374reference with the handle object, the callback and the remaining 1857handle object, the original callback and the remaining arguments.
1375arguments.
1376 1858
1377The code reference is supposed to return a callback (usually a closure) 1859The function is supposed to return a callback (usually a closure) that
1378that works as a plain read callback (see C<< ->push_read ($cb) >>). 1860works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1861mentally treat the function as a "configurable read type to read callback"
1862converter.
1379 1863
1380It should invoke the passed callback when it is done reading (remember to 1864It should invoke the original callback when it is done reading (remember
1381pass C<$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).
1382 1867
1383Note that this is a function, and all types registered this way will be
1384global, so try to use unique names.
1385
1386For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1868For examples, see the source of this module (F<perldoc -m
1387search for C<register_read_type>)). 1869AnyEvent::Handle>, search for C<register_read_type>)).
1388 1870
1389=item $handle->stop_read 1871=item $handle->stop_read
1390 1872
1391=item $handle->start_read 1873=item $handle->start_read
1392 1874
1398Note that AnyEvent::Handle will automatically C<start_read> for you when 1880Note that AnyEvent::Handle will automatically C<start_read> for you when
1399you change the C<on_read> callback or push/unshift a read callback, and it 1881you change the C<on_read> callback or push/unshift a read callback, and it
1400will automatically C<stop_read> for you when neither C<on_read> is set nor 1882will automatically C<stop_read> for you when neither C<on_read> is set nor
1401there are any read requests in the queue. 1883there are any read requests in the queue.
1402 1884
1403These methods will have no effect when in TLS mode (as TLS doesn't support 1885In older versions of this module (<= 5.3), these methods had no effect,
1404half-duplex connections). 1886as TLS does not support half-duplex connections. In current versions they
1887work as expected, as this behaviour is required to avoid certain resource
1888attacks, where the program would be forced to read (and buffer) arbitrary
1889amounts of data before being able to send some data. The drawback is that
1890some readings of the the SSL/TLS specifications basically require this
1891attack to be working, as SSL/TLS implementations might stall sending data
1892during a rehandshake.
1893
1894As a guideline, during the initial handshake, you should not stop reading,
1895and as a client, it might cause problems, depending on your application.
1405 1896
1406=cut 1897=cut
1407 1898
1408sub stop_read { 1899sub stop_read {
1409 my ($self) = @_; 1900 my ($self) = @_;
1410 1901
1411 delete $self->{_rw} unless $self->{tls}; 1902 delete $self->{_rw};
1412} 1903}
1413 1904
1414sub start_read { 1905sub start_read {
1415 my ($self) = @_; 1906 my ($self) = @_;
1416 1907
1417 unless ($self->{_rw} || $self->{_eof}) { 1908 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1418 Scalar::Util::weaken $self; 1909 Scalar::Util::weaken $self;
1419 1910
1420 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1911 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1421 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf}); 1912 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1422 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1913 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1423 1914
1424 if ($len > 0) { 1915 if ($len > 0) {
1425 $self->{_activity} = AnyEvent->now; 1916 $self->{_activity} = $self->{_ractivity} = AE::now;
1426 1917
1427 if ($self->{tls}) { 1918 if ($self->{tls}) {
1428 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); 1919 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1429 1920
1430 &_dotls ($self); 1921 &_dotls ($self);
1431 } else { 1922 } else {
1432 $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);
1433 } 1930 }
1434 1931
1435 } elsif (defined $len) { 1932 } elsif (defined $len) {
1436 delete $self->{_rw}; 1933 delete $self->{_rw};
1437 $self->{_eof} = 1; 1934 $self->{_eof} = 1;
1438 $self->_drain_rbuf unless $self->{_in_drain}; 1935 $self->_drain_rbuf;
1439 1936
1440 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 1937 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1441 return $self->_error ($!, 1); 1938 return $self->_error ($!, 1);
1442 } 1939 }
1443 }); 1940 };
1444 } 1941 }
1445} 1942}
1446 1943
1447our $ERROR_SYSCALL; 1944our $ERROR_SYSCALL;
1448our $ERROR_WANT_READ; 1945our $ERROR_WANT_READ;
1451 my ($self, $err) = @_; 1948 my ($self, $err) = @_;
1452 1949
1453 return $self->_error ($!, 1) 1950 return $self->_error ($!, 1)
1454 if $err == Net::SSLeay::ERROR_SYSCALL (); 1951 if $err == Net::SSLeay::ERROR_SYSCALL ();
1455 1952
1456 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 ());
1457 1954
1458 # reduce error string to look less scary 1955 # reduce error string to look less scary
1459 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /; 1956 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1460 1957
1461 if ($self->{_on_starttls}) { 1958 if ($self->{_on_starttls}) {
1503 $self->{_eof} = 1; 2000 $self->{_eof} = 1;
1504 } 2001 }
1505 } 2002 }
1506 2003
1507 $self->{_tls_rbuf} .= $tmp; 2004 $self->{_tls_rbuf} .= $tmp;
1508 $self->_drain_rbuf unless $self->{_in_drain}; 2005 $self->_drain_rbuf;
1509 $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
1510 } 2007 }
1511 2008
1512 $tmp = Net::SSLeay::get_error ($self->{tls}, -1); 2009 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1513 return $self->_tls_error ($tmp) 2010 return $self->_tls_error ($tmp)
1515 && ($tmp != $ERROR_SYSCALL || $!); 2012 && ($tmp != $ERROR_SYSCALL || $!);
1516 2013
1517 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) { 2014 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1518 $self->{wbuf} .= $tmp; 2015 $self->{wbuf} .= $tmp;
1519 $self->_drain_wbuf; 2016 $self->_drain_wbuf;
2017 $self->{tls} or return; # tls session might have gone away in callback
1520 } 2018 }
1521 2019
1522 $self->{_on_starttls} 2020 $self->{_on_starttls}
1523 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK () 2021 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1524 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established"); 2022 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1526 2024
1527=item $handle->starttls ($tls[, $tls_ctx]) 2025=item $handle->starttls ($tls[, $tls_ctx])
1528 2026
1529Instead of starting TLS negotiation immediately when the AnyEvent::Handle 2027Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1530object 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
1531C<starttls>. 2029C<starttls>. See the C<tls> constructor argument for general info.
1532 2030
1533Starting TLS is currently an asynchronous operation - when you push some 2031Starting TLS is currently an asynchronous operation - when you push some
1534write data and then call C<< ->starttls >> then TLS negotiation will start 2032write data and then call C<< ->starttls >> then TLS negotiation will start
1535immediately, after which the queued write data is then sent. 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.
1536 2036
1537The 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
1538C<"connect">, C<"accept"> or an existing Net::SSLeay object). 2038C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1539 2039
1540The 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
1545The 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
1546context in C<< $handle->{tls_ctx} >> after this call and can be used or 2046context in C<< $handle->{tls_ctx} >> after this call and can be used or
1547changed to your liking. Note that the handshake might have already started 2047changed to your liking. Note that the handshake might have already started
1548when this function returns. 2048when this function returns.
1549 2049
1550If it an error to start a TLS handshake more than once per 2050Due to bugs in OpenSSL, it might or might not be possible to do multiple
1551AnyEvent::Handle object (this is due to bugs in OpenSSL). 2051handshakes on the same stream. It is best to not attempt to use the
2052stream after stopping TLS.
2053
2054This method may invoke callbacks (and therefore the handle might be
2055destroyed after it returns).
1552 2056
1553=cut 2057=cut
1554 2058
1555our %TLS_CACHE; #TODO not yet documented, should we? 2059our %TLS_CACHE; #TODO not yet documented, should we?
1556 2060
1557sub starttls { 2061sub starttls {
1558 my ($self, $ssl, $ctx) = @_; 2062 my ($self, $tls, $ctx) = @_;
1559 2063
1560 require Net::SSLeay; 2064 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1561
1562 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1563 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};
1564 2079
1565 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL (); 2080 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1566 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ (); 2081 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1567 2082
2083 $tls = delete $self->{tls};
1568 $ctx ||= $self->{tls_ctx}; 2084 $ctx = $self->{tls_ctx};
1569 2085
1570 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session 2086 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1571 2087
1572 if ("HASH" eq ref $ctx) { 2088 if ("HASH" eq ref $ctx) {
1573 require AnyEvent::TLS;
1574
1575 if ($ctx->{cache}) { 2089 if ($ctx->{cache}) {
1576 my $key = $ctx+0; 2090 my $key = $ctx+0;
1577 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx; 2091 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1578 } else { 2092 } else {
1579 $ctx = new AnyEvent::TLS %$ctx; 2093 $ctx = new AnyEvent::TLS %$ctx;
1580 } 2094 }
1581 } 2095 }
1582 2096
1583 $self->{tls_ctx} = $ctx || TLS_CTX (); 2097 $self->{tls_ctx} = $ctx || TLS_CTX ();
1584 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername}); 2098 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1585 2099
1586 # basically, this is deep magic (because SSL_read should have the same issues) 2100 # basically, this is deep magic (because SSL_read should have the same issues)
1587 # but the openssl maintainers basically said: "trust us, it just works". 2101 # but the openssl maintainers basically said: "trust us, it just works".
1588 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 2102 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1589 # and mismaintained ssleay-module doesn't even offer them). 2103 # and mismaintained ssleay-module doesn't even offer them).
1596 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to 2110 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1597 # have identity issues in that area. 2111 # have identity issues in that area.
1598# Net::SSLeay::CTX_set_mode ($ssl, 2112# Net::SSLeay::CTX_set_mode ($ssl,
1599# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 2113# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1600# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 2114# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1601 Net::SSLeay::CTX_set_mode ($ssl, 1|2); 2115 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1602 2116
1603 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2117 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1604 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2118 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1605 2119
2120 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2121 $self->{rbuf} = "";
2122
1606 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2123 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1607 2124
1608 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) } 2125 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1609 if $self->{on_starttls}; 2126 if $self->{on_starttls};
1610 2127
1611 &_dotls; # need to trigger the initial handshake 2128 &_dotls; # need to trigger the initial handshake
1614 2131
1615=item $handle->stoptls 2132=item $handle->stoptls
1616 2133
1617Shuts down the SSL connection - this makes a proper EOF handshake by 2134Shuts down the SSL connection - this makes a proper EOF handshake by
1618sending a close notify to the other side, but since OpenSSL doesn't 2135sending a close notify to the other side, but since OpenSSL doesn't
1619support non-blocking shut downs, it is not possible to re-use the stream 2136support non-blocking shut downs, it is not guaranteed that you can re-use
1620afterwards. 2137the stream afterwards.
2138
2139This method may invoke callbacks (and therefore the handle might be
2140destroyed after it returns).
1621 2141
1622=cut 2142=cut
1623 2143
1624sub stoptls { 2144sub stoptls {
1625 my ($self) = @_; 2145 my ($self) = @_;
1626 2146
1627 if ($self->{tls}) { 2147 if ($self->{tls} && $self->{fh}) {
1628 Net::SSLeay::shutdown ($self->{tls}); 2148 Net::SSLeay::shutdown ($self->{tls});
1629 2149
1630 &_dotls; 2150 &_dotls;
1631 2151
1632# # we don't give a shit. no, we do, but we can't. no...#d# 2152# # we don't give a shit. no, we do, but we can't. no...#d#
1638sub _freetls { 2158sub _freetls {
1639 my ($self) = @_; 2159 my ($self) = @_;
1640 2160
1641 return unless $self->{tls}; 2161 return unless $self->{tls};
1642 2162
1643 $self->{tls_ctx}->_put_session (delete $self->{tls}); 2163 $self->{tls_ctx}->_put_session (delete $self->{tls})
2164 if $self->{tls} > 0;
1644 2165
1645 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)}; 2166 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1646} 2167}
2168
2169=item $handle->resettls
2170
2171This rarely-used method simply resets and TLS state on the handle, usually
2172causing data loss.
2173
2174One case where it may be useful is when you want to skip over the data in
2175the stream but you are not interested in interpreting it, so data loss is
2176no concern.
2177
2178=cut
2179
2180*resettls = \&_freetls;
1647 2181
1648sub DESTROY { 2182sub DESTROY {
1649 my ($self) = @_; 2183 my ($self) = @_;
1650 2184
1651 &_freetls; 2185 &_freetls;
1656 my $fh = delete $self->{fh}; 2190 my $fh = delete $self->{fh};
1657 my $wbuf = delete $self->{wbuf}; 2191 my $wbuf = delete $self->{wbuf};
1658 2192
1659 my @linger; 2193 my @linger;
1660 2194
1661 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub { 2195 push @linger, AE::io $fh, 1, sub {
1662 my $len = syswrite $fh, $wbuf, length $wbuf; 2196 my $len = syswrite $fh, $wbuf, length $wbuf;
1663 2197
1664 if ($len > 0) { 2198 if ($len > 0) {
1665 substr $wbuf, 0, $len, ""; 2199 substr $wbuf, 0, $len, "";
1666 } else { 2200 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1667 @linger = (); # end 2201 @linger = (); # end
1668 } 2202 }
1669 }); 2203 };
1670 push @linger, AnyEvent->timer (after => $linger, cb => sub { 2204 push @linger, AE::timer $linger, 0, sub {
1671 @linger = (); 2205 @linger = ();
1672 }); 2206 };
1673 } 2207 }
1674} 2208}
1675 2209
1676=item $handle->destroy 2210=item $handle->destroy
1677 2211
1678Shuts down the handle object as much as possible - this call ensures that 2212Shuts down the handle object as much as possible - this call ensures that
1679no further callbacks will be invoked and as many resources as possible 2213no further callbacks will be invoked and as many resources as possible
1680will be freed. You must not call any methods on the object afterwards. 2214will be freed. Any method you will call on the handle object after
2215destroying it in this way will be silently ignored (and it will return the
2216empty list).
1681 2217
1682Normally, you can just "forget" any references to an AnyEvent::Handle 2218Normally, you can just "forget" any references to an AnyEvent::Handle
1683object and it will simply shut down. This works in fatal error and EOF 2219object and it will simply shut down. This works in fatal error and EOF
1684callbacks, as well as code outside. It does I<NOT> work in a read or write 2220callbacks, as well as code outside. It does I<NOT> work in a read or write
1685callback, so when you want to destroy the AnyEvent::Handle object from 2221callback, so when you want to destroy the AnyEvent::Handle object from
1699sub destroy { 2235sub destroy {
1700 my ($self) = @_; 2236 my ($self) = @_;
1701 2237
1702 $self->DESTROY; 2238 $self->DESTROY;
1703 %$self = (); 2239 %$self = ();
2240 bless $self, "AnyEvent::Handle::destroyed";
1704} 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 }
1705 2269
1706=item AnyEvent::Handle::TLS_CTX 2270=item AnyEvent::Handle::TLS_CTX
1707 2271
1708This function creates and returns the AnyEvent::TLS object used by default 2272This function creates and returns the AnyEvent::TLS object used by default
1709for TLS mode. 2273for TLS mode.
1737 2301
1738It 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,
1739from within all other callbacks, you need to explicitly call the C<< 2303from within all other callbacks, you need to explicitly call the C<<
1740->destroy >> method. 2304->destroy >> method.
1741 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
1742=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
1743reading? 2387reading?
1744 2388
1745Unlike, say, TCP, TLS connections do not consist of two independent 2389Unlike, say, TCP, TLS connections do not consist of two independent
1746communication channels, one for each direction. Or put differently. The 2390communication channels, one for each direction. Or put differently, the
1747read and write directions are not independent of each other: you cannot 2391read and write directions are not independent of each other: you cannot
1748write data unless you are also prepared to read, and vice versa. 2392write data unless you are also prepared to read, and vice versa.
1749 2393
1750This 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>
1751callback invocations when you are not expecting any read data - the reason 2395callback invocations when you are not expecting any read data - the reason
1752is that AnyEvent::Handle always reads in TLS mode. 2396is that AnyEvent::Handle always reads in TLS mode.
1753 2397
1754During 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
1755non-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
1767 $handle->on_eof (undef); 2411 $handle->on_eof (undef);
1768 $handle->on_error (sub { 2412 $handle->on_error (sub {
1769 my $data = delete $_[0]{rbuf}; 2413 my $data = delete $_[0]{rbuf};
1770 }); 2414 });
1771 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
1772The 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
1773and 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
1774fact, all data has been received. 2422fact all data has been received.
1775 2423
1776It is usually better to use acknowledgements when transferring data, 2424It is usually better to use acknowledgements when transferring data,
1777to 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
1778intact. 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
1779explicit QUIT command. 2427explicit QUIT command.
1786C<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
1787written to the socket: 2435written to the socket:
1788 2436
1789 $handle->push_write (...); 2437 $handle->push_write (...);
1790 $handle->on_drain (sub { 2438 $handle->on_drain (sub {
1791 warn "all data submitted to the kernel\n"; 2439 AE::log debug => "All data submitted to the kernel.";
1792 undef $handle; 2440 undef $handle;
1793 }); 2441 });
1794 2442
1795If 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,
1796consider using C<< ->push_shutdown >> instead. 2444consider using C<< ->push_shutdown >> instead.
1797 2445
1798=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.
1799 2447
1800If 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,
1801simply 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>
1802parameter: 2450parameter:
1803 2451
1804 tcp_connect $host, $port, sub { 2452 tcp_connect $host, $port, sub {
1805 my ($fh) = @_; 2453 my ($fh) = @_;
1806 2454
1880When you have intermediate CA certificates that your clients might not 2528When you have intermediate CA certificates that your clients might not
1881know about, just append them to the C<cert_file>. 2529know about, just append them to the C<cert_file>.
1882 2530
1883=back 2531=back
1884 2532
1885
1886=head1 SUBCLASSING AnyEvent::Handle 2533=head1 SUBCLASSING AnyEvent::Handle
1887 2534
1888In many cases, you might want to subclass AnyEvent::Handle. 2535In many cases, you might want to subclass AnyEvent::Handle.
1889 2536
1890To make this easier, a given version of AnyEvent::Handle uses these 2537To make this easier, a given version of AnyEvent::Handle uses these
1906 2553
1907=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
1908are free to use in subclasses. 2555are free to use in subclasses.
1909 2556
1910Of course, new versions of AnyEvent::Handle may introduce more "public" 2557Of course, new versions of AnyEvent::Handle may introduce more "public"
1911member variables, but thats just life, at least it is documented. 2558member variables, but that's just life. At least it is documented.
1912 2559
1913=back 2560=back
1914 2561
1915=head1 AUTHOR 2562=head1 AUTHOR
1916 2563
1917Robin 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>.
1918 2565
1919=cut 2566=cut
1920 2567
19211; # End of AnyEvent::Handle 25681
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