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Revision 1.212 by root, Fri Dec 31 04:50:44 2010 UTC

1package AnyEvent::Handle;
2
3no warnings;
4use strict;
5
6use AnyEvent ();
7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util ();
9use Carp ();
10use Fcntl ();
11use Errno qw(EAGAIN EINTR);
12
13=head1 NAME 1=head1 NAME
14 2
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
16
17=cut
18
19our $VERSION = 4.12;
20 4
21=head1 SYNOPSIS 5=head1 SYNOPSIS
22 6
23 use AnyEvent; 7 use AnyEvent;
24 use AnyEvent::Handle; 8 use AnyEvent::Handle;
25 9
26 my $cv = AnyEvent->condvar; 10 my $cv = AnyEvent->condvar;
27 11
28 my $handle = 12 my $hdl; $hdl = new AnyEvent::Handle
29 AnyEvent::Handle->new (
30 fh => \*STDIN, 13 fh => \*STDIN,
31 on_eof => sub { 14 on_error => sub {
32 $cv->broadcast; 15 my ($hdl, $fatal, $msg) = @_;
33 }, 16 warn "got error $msg\n";
17 $hdl->destroy;
18 $cv->send;
34 ); 19 };
35 20
36 # send some request line 21 # send some request line
37 $handle->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
38 23
39 # read the response line 24 # read the response line
40 $handle->push_read (line => sub { 25 $hdl->push_read (line => sub {
41 my ($handle, $line) = @_; 26 my ($hdl, $line) = @_;
42 warn "read line <$line>\n"; 27 warn "got line <$line>\n";
43 $cv->send; 28 $cv->send;
44 }); 29 });
45 30
46 $cv->recv; 31 $cv->recv;
47 32
48=head1 DESCRIPTION 33=head1 DESCRIPTION
49 34
50This 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
51filehandles. For utility functions for doing non-blocking connects and accepts 36stream-based filehandles (sockets, pipes, and other stream things).
52on sockets see L<AnyEvent::Util>.
53 37
38The L<AnyEvent::Intro> tutorial contains some well-documented
39AnyEvent::Handle examples.
40
54In the following, when the documentation refers to of "bytes" then this 41In the following, where the documentation refers to "bytes", it means
55means characters. As sysread and syswrite are used for all I/O, their 42characters. As sysread and syswrite are used for all I/O, their
56treatment 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.
57 47
58All callbacks will be invoked with the handle object as their first 48All callbacks will be invoked with the handle object as their first
59argument. 49argument.
60 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
61=head1 METHODS 82=head1 METHODS
62 83
63=over 4 84=over 4
64 85
65=item B<new (%args)> 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66 87
67The constructor supports these arguments (all as key => value pairs). 88The constructor supports these arguments (all as C<< key => value >> pairs).
68 89
69=over 4 90=over 4
70 91
71=item fh => $filehandle [MANDATORY] 92=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72 93
73The filehandle this L<AnyEvent::Handle> object will operate on. 94The filehandle this L<AnyEvent::Handle> object will operate on.
74
75NOTE: The filehandle will be set to non-blocking (using 95NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 96C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
97that mode.
77 98
99=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
100
101Try to connect to the specified host and service (port), using
102C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
103default C<peername>.
104
105You have to specify either this parameter, or C<fh>, above.
106
107It is possible to push requests on the read and write queues, and modify
108properties of the stream, even while AnyEvent::Handle is connecting.
109
110When this parameter is specified, then the C<on_prepare>,
111C<on_connect_error> and C<on_connect> callbacks will be called under the
112appropriate circumstances:
113
114=over 4
115
78=item on_eof => $cb->($handle) 116=item on_prepare => $cb->($handle)
79 117
80Set the callback to be called when an end-of-file condition is detcted, 118This (rarely used) callback is called before a new connection is
81i.e. in the case of a socket, when the other side has closed the 119attempted, but after the file handle has been created (you can access that
82connection cleanly. 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).
83 123
84While not mandatory, it is highly recommended to set an eof callback, 124The return value of this callback should be the connect timeout value in
85otherwise you might end up with a closed socket while you are still 125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
86waiting for data. 126default timeout is to be used).
87 127
128=item on_connect => $cb->($handle, $host, $port, $retry->())
129
130This callback is called when a connection has been successfully established.
131
132The peer's numeric host and port (the socket peername) are passed as
133parameters, together with a retry callback.
134
135If, for some reason, the handle is not acceptable, calling C<$retry>
136will continue with the next connection target (in case of multi-homed
137hosts or SRV records there can be multiple connection endpoints). At the
138time it is called the read and write queues, eof status, tls status and
139similar properties of the handle will have been reset.
140
141In most cases, you should ignore the C<$retry> parameter.
142
143=item on_connect_error => $cb->($handle, $message)
144
145This callback is called when the connection could not be
146established. C<$!> will contain the relevant error code, and C<$message> a
147message describing it (usually the same as C<"$!">).
148
149If this callback isn't specified, then C<on_error> will be called with a
150fatal error instead.
151
152=back
153
88=item on_error => $cb->($handle, $fatal) 154=item on_error => $cb->($handle, $fatal, $message)
89 155
90This is the error callback, which is called when, well, some error 156This is the error callback, which is called when, well, some error
91occured, such as not being able to resolve the hostname, failure to 157occured, such as not being able to resolve the hostname, failure to
92connect or a read error. 158connect, or a read error.
93 159
94Some errors are fatal (which is indicated by C<$fatal> being true). On 160Some errors are fatal (which is indicated by C<$fatal> being true). On
95fatal errors the handle object will be shut down and will not be 161fatal errors the handle object will be destroyed (by a call to C<< ->
162destroy >>) after invoking the error callback (which means you are free to
163examine the handle object). Examples of fatal errors are an EOF condition
164with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
165cases where the other side can close the connection at will, it is
166often easiest to not report C<EPIPE> errors in this callback.
167
168AnyEvent::Handle tries to find an appropriate error code for you to check
169against, but in some cases (TLS errors), this does not work well. It is
170recommended to always output the C<$message> argument in human-readable
171error messages (it's usually the same as C<"$!">).
172
96usable. Non-fatal errors can be retried by simply returning, but it is 173Non-fatal errors can be retried by returning, but it is recommended
97recommended to simply ignore this parameter and instead abondon the handle 174to simply ignore this parameter and instead abondon the handle object
98object when this callback is invoked. 175when this callback is invoked. Examples of non-fatal errors are timeouts
176C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
99 177
100On callback entrance, the value of C<$!> contains the operating system 178On entry to the callback, the value of C<$!> contains the operating
101error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 179system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
180C<EPROTO>).
102 181
103While not mandatory, it is I<highly> recommended to set this callback, as 182While not mandatory, it is I<highly> recommended to set this callback, as
104you will not be notified of errors otherwise. The default simply calls 183you will not be notified of errors otherwise. The default just calls
105C<croak>. 184C<croak>.
106 185
107=item on_read => $cb->($handle) 186=item on_read => $cb->($handle)
108 187
109This sets the default read callback, which is called when data arrives 188This sets the default read callback, which is called when data arrives
110and no read request is in the queue. 189and no read request is in the queue (unlike read queue callbacks, this
190callback will only be called when at least one octet of data is in the
191read buffer).
111 192
112To access (and remove data from) the read buffer, use the C<< ->rbuf >> 193To access (and remove data from) the read buffer, use the C<< ->rbuf >>
113method or access the C<$handle->{rbuf}> member directly. 194method or access the C<< $handle->{rbuf} >> member directly. Note that you
195must not enlarge or modify the read buffer, you can only remove data at
196the beginning from it.
114 197
198You can also call C<< ->push_read (...) >> or any other function that
199modifies the read queue. Or do both. Or ...
200
115When an EOF condition is detected then AnyEvent::Handle will first try to 201When an EOF condition is detected, AnyEvent::Handle will first try to
116feed all the remaining data to the queued callbacks and C<on_read> before 202feed all the remaining data to the queued callbacks and C<on_read> before
117calling the C<on_eof> callback. If no progress can be made, then a fatal 203calling the C<on_eof> callback. If no progress can be made, then a fatal
118error will be raised (with C<$!> set to C<EPIPE>). 204error will be raised (with C<$!> set to C<EPIPE>).
119 205
206Note that, unlike requests in the read queue, an C<on_read> callback
207doesn't mean you I<require> some data: if there is an EOF and there
208are outstanding read requests then an error will be flagged. With an
209C<on_read> callback, the C<on_eof> callback will be invoked.
210
211=item on_eof => $cb->($handle)
212
213Set the callback to be called when an end-of-file condition is detected,
214i.e. in the case of a socket, when the other side has closed the
215connection cleanly, and there are no outstanding read requests in the
216queue (if there are read requests, then an EOF counts as an unexpected
217connection close and will be flagged as an error).
218
219For sockets, this just means that the other side has stopped sending data,
220you can still try to write data, and, in fact, one can return from the EOF
221callback and continue writing data, as only the read part has been shut
222down.
223
224If an EOF condition has been detected but no C<on_eof> callback has been
225set, then a fatal error will be raised with C<$!> set to <0>.
226
120=item on_drain => $cb->($handle) 227=item on_drain => $cb->($handle)
121 228
122This sets the callback that is called when the write buffer becomes empty 229This sets the callback that is called when the write buffer becomes empty
123(or when the callback is set and the buffer is empty already). 230(or immediately if the buffer is empty already).
124 231
125To append to the write buffer, use the C<< ->push_write >> method. 232To append to the write buffer, use the C<< ->push_write >> method.
126 233
234This callback is useful when you don't want to put all of your write data
235into the queue at once, for example, when you want to write the contents
236of some file to the socket you might not want to read the whole file into
237memory and push it into the queue, but instead only read more data from
238the file when the write queue becomes empty.
239
127=item timeout => $fractional_seconds 240=item timeout => $fractional_seconds
128 241
242=item rtimeout => $fractional_seconds
243
244=item wtimeout => $fractional_seconds
245
129If non-zero, then this enables an "inactivity" timeout: whenever this many 246If non-zero, then these enables an "inactivity" timeout: whenever this
130seconds pass without a successful read or write on the underlying file 247many seconds pass without a successful read or write on the underlying
131handle, the C<on_timeout> callback will be invoked (and if that one is 248file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
132missing, an C<ETIMEDOUT> error will be raised). 249will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
250error will be raised).
133 251
252There are three variants of the timeouts that work independently
253of each other, for both read and write, just read, and just write:
254C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
255C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
256C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
257
134Note that timeout processing is also active when you currently do not have 258Note that timeout processing is active even when you do not have
135any outstanding read or write requests: If you plan to keep the connection 259any outstanding read or write requests: If you plan to keep the connection
136idle then you should disable the timout temporarily or ignore the timeout 260idle then you should disable the timeout temporarily or ignore the timeout
137in the C<on_timeout> callback. 261in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
262restart the timeout.
138 263
139Zero (the default) disables this timeout. 264Zero (the default) disables this timeout.
140 265
141=item on_timeout => $cb->($handle) 266=item on_timeout => $cb->($handle)
142 267
146 271
147=item rbuf_max => <bytes> 272=item rbuf_max => <bytes>
148 273
149If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 274If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
150when the read buffer ever (strictly) exceeds this size. This is useful to 275when the read buffer ever (strictly) exceeds this size. This is useful to
151avoid denial-of-service attacks. 276avoid some forms of denial-of-service attacks.
152 277
153For example, a server accepting connections from untrusted sources should 278For example, a server accepting connections from untrusted sources should
154be configured to accept only so-and-so much data that it cannot act on 279be configured to accept only so-and-so much data that it cannot act on
155(for example, when expecting a line, an attacker could send an unlimited 280(for example, when expecting a line, an attacker could send an unlimited
156amount of data without a callback ever being called as long as the line 281amount of data without a callback ever being called as long as the line
157isn't finished). 282isn't finished).
158 283
284=item wbuf_max => <bytes>
285
286If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
287when the write buffer ever (strictly) exceeds this size. This is useful to
288avoid some forms of denial-of-service attacks.
289
290Although the units of this parameter is bytes, this is the I<raw> number
291of bytes not yet accepted by the kernel. This can make a difference when
292you e.g. use TLS, as TLS typically makes your write data larger (but it
293can also make it smaller due to compression).
294
295As an example of when this limit is useful, take a chat server that sends
296chat messages to a client. If the client does not read those in a timely
297manner then the send buffer in the server would grow unbounded.
298
299=item autocork => <boolean>
300
301When disabled (the default), C<push_write> will try to immediately
302write the data to the handle if possible. This avoids having to register
303a write watcher and wait for the next event loop iteration, but can
304be inefficient if you write multiple small chunks (on the wire, this
305disadvantage is usually avoided by your kernel's nagle algorithm, see
306C<no_delay>, but this option can save costly syscalls).
307
308When enabled, writes will always be queued till the next event loop
309iteration. This is efficient when you do many small writes per iteration,
310but less efficient when you do a single write only per iteration (or when
311the write buffer often is full). It also increases write latency.
312
313=item no_delay => <boolean>
314
315When doing small writes on sockets, your operating system kernel might
316wait a bit for more data before actually sending it out. This is called
317the Nagle algorithm, and usually it is beneficial.
318
319In some situations you want as low a delay as possible, which can be
320accomplishd by setting this option to a true value.
321
322The default is your operating system's default behaviour (most likely
323enabled). This option explicitly enables or disables it, if possible.
324
325=item keepalive => <boolean>
326
327Enables (default disable) the SO_KEEPALIVE option on the stream socket:
328normally, TCP connections have no time-out once established, so TCP
329connections, once established, can stay alive forever even when the other
330side has long gone. TCP keepalives are a cheap way to take down long-lived
331TCP connections when the other side becomes unreachable. While the default
332is OS-dependent, TCP keepalives usually kick in after around two hours,
333and, if the other side doesn't reply, take down the TCP connection some 10
334to 15 minutes later.
335
336It is harmless to specify this option for file handles that do not support
337keepalives, and enabling it on connections that are potentially long-lived
338is usually a good idea.
339
340=item oobinline => <boolean>
341
342BSD majorly fucked up the implementation of TCP urgent data. The result
343is that almost no OS implements TCP according to the specs, and every OS
344implements it slightly differently.
345
346If you want to handle TCP urgent data, then setting this flag (the default
347is enabled) gives you the most portable way of getting urgent data, by
348putting it into the stream.
349
350Since BSD emulation of OOB data on top of TCP's urgent data can have
351security implications, AnyEvent::Handle sets this flag automatically
352unless explicitly specified. Note that setting this flag after
353establishing a connection I<may> be a bit too late (data loss could
354already have occured on BSD systems), but at least it will protect you
355from most attacks.
356
159=item read_size => <bytes> 357=item read_size => <bytes>
160 358
161The default read block size (the amount of bytes this module will try to read 359The initial read block size, the number of bytes this module will try to
162during each (loop iteration). Default: C<8192>. 360read during each loop iteration. Each handle object will consume at least
361this amount of memory for the read buffer as well, so when handling many
362connections requirements). See also C<max_read_size>. Default: C<2048>.
363
364=item max_read_size => <bytes>
365
366The maximum read buffer size used by the dynamic adjustment
367algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
368one go it will double C<read_size> up to the maximum given by this
369option. Default: C<131072> or C<read_size>, whichever is higher.
163 370
164=item low_water_mark => <bytes> 371=item low_water_mark => <bytes>
165 372
166Sets the amount of bytes (default: C<0>) that make up an "empty" write 373Sets the number of bytes (default: C<0>) that make up an "empty" write
167buffer: If the write reaches this size or gets even samller it is 374buffer: If the buffer reaches this size or gets even samller it is
168considered empty. 375considered empty.
169 376
377Sometimes it can be beneficial (for performance reasons) to add data to
378the write buffer before it is fully drained, but this is a rare case, as
379the operating system kernel usually buffers data as well, so the default
380is good in almost all cases.
381
382=item linger => <seconds>
383
384If this is non-zero (default: C<3600>), the destructor of the
385AnyEvent::Handle object will check whether there is still outstanding
386write data and will install a watcher that will write this data to the
387socket. No errors will be reported (this mostly matches how the operating
388system treats outstanding data at socket close time).
389
390This will not work for partial TLS data that could not be encoded
391yet. This data will be lost. Calling the C<stoptls> method in time might
392help.
393
394=item peername => $string
395
396A string used to identify the remote site - usually the DNS hostname
397(I<not> IDN!) used to create the connection, rarely the IP address.
398
399Apart from being useful in error messages, this string is also used in TLS
400peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
401verification will be skipped when C<peername> is not specified or is
402C<undef>.
403
170=item tls => "accept" | "connect" | Net::SSLeay::SSL object 404=item tls => "accept" | "connect" | Net::SSLeay::SSL object
171 405
172When this parameter is given, it enables TLS (SSL) mode, that means it 406When this parameter is given, it enables TLS (SSL) mode, that means
173will start making tls handshake and will transparently encrypt/decrypt 407AnyEvent will start a TLS handshake as soon as the connection has been
174data. 408established and will transparently encrypt/decrypt data afterwards.
409
410All TLS protocol errors will be signalled as C<EPROTO>, with an
411appropriate error message.
175 412
176TLS mode requires Net::SSLeay to be installed (it will be loaded 413TLS mode requires Net::SSLeay to be installed (it will be loaded
177automatically when you try to create a TLS handle). 414automatically when you try to create a TLS handle): this module doesn't
415have a dependency on that module, so if your module requires it, you have
416to add the dependency yourself.
178 417
179For the TLS server side, use C<accept>, and for the TLS client side of a 418Unlike TCP, TLS has a server and client side: for the TLS server side, use
180connection, use C<connect> mode. 419C<accept>, and for the TLS client side of a connection, use C<connect>
420mode.
181 421
182You can also provide your own TLS connection object, but you have 422You can also provide your own TLS connection object, but you have
183to make sure that you call either C<Net::SSLeay::set_connect_state> 423to make sure that you call either C<Net::SSLeay::set_connect_state>
184or C<Net::SSLeay::set_accept_state> on it before you pass it to 424or C<Net::SSLeay::set_accept_state> on it before you pass it to
185AnyEvent::Handle. 425AnyEvent::Handle. Also, this module will take ownership of this connection
426object.
186 427
428At some future point, AnyEvent::Handle might switch to another TLS
429implementation, then the option to use your own session object will go
430away.
431
432B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
433passing in the wrong integer will lead to certain crash. This most often
434happens when one uses a stylish C<< tls => 1 >> and is surprised about the
435segmentation fault.
436
187See the C<starttls> method if you need to start TLs negotiation later. 437Use the C<< ->starttls >> method if you need to start TLS negotiation later.
188 438
189=item tls_ctx => $ssl_ctx 439=item tls_ctx => $anyevent_tls
190 440
191Use the given Net::SSLeay::CTX object to create the new TLS connection 441Use the given C<AnyEvent::TLS> object to create the new TLS connection
192(unless a connection object was specified directly). If this parameter is 442(unless a connection object was specified directly). If this
193missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 443parameter is missing (or C<undef>), then AnyEvent::Handle will use
444C<AnyEvent::Handle::TLS_CTX>.
445
446Instead of an object, you can also specify a hash reference with C<< key
447=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
448new TLS context object.
449
450=item on_starttls => $cb->($handle, $success[, $error_message])
451
452This callback will be invoked when the TLS/SSL handshake has finished. If
453C<$success> is true, then the TLS handshake succeeded, otherwise it failed
454(C<on_stoptls> will not be called in this case).
455
456The session in C<< $handle->{tls} >> can still be examined in this
457callback, even when the handshake was not successful.
458
459TLS handshake failures will not cause C<on_error> to be invoked when this
460callback is in effect, instead, the error message will be passed to C<on_starttls>.
461
462Without this callback, handshake failures lead to C<on_error> being
463called as usual.
464
465Note that you cannot just call C<starttls> again in this callback. If you
466need to do that, start an zero-second timer instead whose callback can
467then call C<< ->starttls >> again.
468
469=item on_stoptls => $cb->($handle)
470
471When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
472set, then it will be invoked after freeing the TLS session. If it is not,
473then a TLS shutdown condition will be treated like a normal EOF condition
474on the handle.
475
476The session in C<< $handle->{tls} >> can still be examined in this
477callback.
478
479This callback will only be called on TLS shutdowns, not when the
480underlying handle signals EOF.
194 481
195=item json => JSON or JSON::XS object 482=item json => JSON or JSON::XS object
196 483
197This is the json coder object used by the C<json> read and write types. 484This is the json coder object used by the C<json> read and write types.
198 485
199If you don't supply it, then AnyEvent::Handle will create and use a 486If you don't supply it, then AnyEvent::Handle will create and use a
200suitable one, which will write and expect UTF-8 encoded JSON texts. 487suitable one (on demand), which will write and expect UTF-8 encoded JSON
488texts.
201 489
202Note that you are responsible to depend on the JSON module if you want to 490Note that you are responsible to depend on the JSON module if you want to
203use this functionality, as AnyEvent does not have a dependency itself. 491use this functionality, as AnyEvent does not have a dependency itself.
204 492
205=item filter_r => $cb
206
207=item filter_w => $cb
208
209These exist, but are undocumented at this time.
210
211=back 493=back
212 494
213=cut 495=cut
214 496
215sub new { 497sub new {
216 my $class = shift; 498 my $class = shift;
217
218 my $self = bless { @_ }, $class; 499 my $self = bless { @_ }, $class;
219 500
220 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 501 if ($self->{fh}) {
502 $self->_start;
503 return unless $self->{fh}; # could be gone by now
504
505 } elsif ($self->{connect}) {
506 require AnyEvent::Socket;
507
508 $self->{peername} = $self->{connect}[0]
509 unless exists $self->{peername};
510
511 $self->{_skip_drain_rbuf} = 1;
512
513 {
514 Scalar::Util::weaken (my $self = $self);
515
516 $self->{_connect} =
517 AnyEvent::Socket::tcp_connect (
518 $self->{connect}[0],
519 $self->{connect}[1],
520 sub {
521 my ($fh, $host, $port, $retry) = @_;
522
523 delete $self->{_connect}; # no longer needed
524
525 if ($fh) {
526 $self->{fh} = $fh;
527
528 delete $self->{_skip_drain_rbuf};
529 $self->_start;
530
531 $self->{on_connect}
532 and $self->{on_connect}($self, $host, $port, sub {
533 delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
534 $self->{_skip_drain_rbuf} = 1;
535 &$retry;
536 });
537
538 } else {
539 if ($self->{on_connect_error}) {
540 $self->{on_connect_error}($self, "$!");
541 $self->destroy;
542 } else {
543 $self->_error ($!, 1);
544 }
545 }
546 },
547 sub {
548 local $self->{fh} = $_[0];
549
550 $self->{on_prepare}
551 ? $self->{on_prepare}->($self)
552 : ()
553 }
554 );
555 }
556
557 } else {
558 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
559 }
560
561 $self
562}
563
564sub _start {
565 my ($self) = @_;
566
567 # too many clueless people try to use udp and similar sockets
568 # with AnyEvent::Handle, do them a favour.
569 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
570 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
571 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
221 572
222 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 573 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
223 574
224 if ($self->{tls}) { 575 $self->{_activity} =
225 require Net::SSLeay; 576 $self->{_ractivity} =
577 $self->{_wactivity} = AE::now;
578
579 $self->{read_size} ||= 2048;
580 $self->{max_read_size} = $self->{read_size}
581 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
582
583 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
584 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
585 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
586
587 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
588 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
589
590 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
591
226 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 592 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
227 } 593 if $self->{tls};
228 594
229# $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; # nop
230# $self->on_error (delete $self->{on_error}) if $self->{on_error}; # nop
231# $self->on_read (delete $self->{on_read} ) if $self->{on_read}; # nop
232 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 595 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
233 596
234 $self->{_activity} = AnyEvent->now;
235 $self->_timeout;
236
237 $self->start_read; 597 $self->start_read
598 if $self->{on_read} || @{ $self->{_queue} };
238 599
239 $self 600 $self->_drain_wbuf;
240}
241
242sub _shutdown {
243 my ($self) = @_;
244
245 delete $self->{_tw};
246 delete $self->{_rw};
247 delete $self->{_ww};
248 delete $self->{fh};
249
250 $self->stoptls;
251} 601}
252 602
253sub _error { 603sub _error {
254 my ($self, $errno, $fatal) = @_; 604 my ($self, $errno, $fatal, $message) = @_;
255
256 $self->_shutdown
257 if $fatal;
258 605
259 $! = $errno; 606 $! = $errno;
607 $message ||= "$!";
260 608
261 if ($self->{on_error}) { 609 if ($self->{on_error}) {
262 $self->{on_error}($self, $fatal); 610 $self->{on_error}($self, $fatal, $message);
263 } else { 611 $self->destroy if $fatal;
612 } elsif ($self->{fh} || $self->{connect}) {
613 $self->destroy;
264 Carp::croak "AnyEvent::Handle uncaught error: $!"; 614 Carp::croak "AnyEvent::Handle uncaught error: $message";
265 } 615 }
266} 616}
267 617
268=item $fh = $handle->fh 618=item $fh = $handle->fh
269 619
270This method returns the file handle of the L<AnyEvent::Handle> object. 620This method returns the file handle used to create the L<AnyEvent::Handle> object.
271 621
272=cut 622=cut
273 623
274sub fh { $_[0]{fh} } 624sub fh { $_[0]{fh} }
275 625
293 $_[0]{on_eof} = $_[1]; 643 $_[0]{on_eof} = $_[1];
294} 644}
295 645
296=item $handle->on_timeout ($cb) 646=item $handle->on_timeout ($cb)
297 647
298Replace the current C<on_timeout> callback, or disables the callback 648=item $handle->on_rtimeout ($cb)
299(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
300argument.
301 649
302=cut 650=item $handle->on_wtimeout ($cb)
303 651
652Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
653callback, or disables the callback (but not the timeout) if C<$cb> =
654C<undef>. See the C<timeout> constructor argument and method.
655
656=cut
657
658# see below
659
660=item $handle->autocork ($boolean)
661
662Enables or disables the current autocork behaviour (see C<autocork>
663constructor argument). Changes will only take effect on the next write.
664
665=cut
666
667sub autocork {
668 $_[0]{autocork} = $_[1];
669}
670
671=item $handle->no_delay ($boolean)
672
673Enables or disables the C<no_delay> setting (see constructor argument of
674the same name for details).
675
676=cut
677
678sub no_delay {
679 $_[0]{no_delay} = $_[1];
680
681 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
682 if $_[0]{fh};
683}
684
685=item $handle->keepalive ($boolean)
686
687Enables or disables the C<keepalive> setting (see constructor argument of
688the same name for details).
689
690=cut
691
692sub keepalive {
693 $_[0]{keepalive} = $_[1];
694
695 eval {
696 local $SIG{__DIE__};
697 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
698 if $_[0]{fh};
699 };
700}
701
702=item $handle->oobinline ($boolean)
703
704Enables or disables the C<oobinline> setting (see constructor argument of
705the same name for details).
706
707=cut
708
709sub oobinline {
710 $_[0]{oobinline} = $_[1];
711
712 eval {
713 local $SIG{__DIE__};
714 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
715 if $_[0]{fh};
716 };
717}
718
719=item $handle->keepalive ($boolean)
720
721Enables or disables the C<keepalive> setting (see constructor argument of
722the same name for details).
723
724=cut
725
726sub keepalive {
727 $_[0]{keepalive} = $_[1];
728
729 eval {
730 local $SIG{__DIE__};
731 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
732 if $_[0]{fh};
733 };
734}
735
736=item $handle->on_starttls ($cb)
737
738Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
739
740=cut
741
742sub on_starttls {
743 $_[0]{on_starttls} = $_[1];
744}
745
746=item $handle->on_stoptls ($cb)
747
748Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
749
750=cut
751
304sub on_timeout { 752sub on_stoptls {
305 $_[0]{on_timeout} = $_[1]; 753 $_[0]{on_stoptls} = $_[1];
754}
755
756=item $handle->rbuf_max ($max_octets)
757
758Configures the C<rbuf_max> setting (C<undef> disables it).
759
760=item $handle->wbuf_max ($max_octets)
761
762Configures the C<wbuf_max> setting (C<undef> disables it).
763
764=cut
765
766sub rbuf_max {
767 $_[0]{rbuf_max} = $_[1];
768}
769
770sub rbuf_max {
771 $_[0]{wbuf_max} = $_[1];
306} 772}
307 773
308############################################################################# 774#############################################################################
309 775
310=item $handle->timeout ($seconds) 776=item $handle->timeout ($seconds)
311 777
778=item $handle->rtimeout ($seconds)
779
780=item $handle->wtimeout ($seconds)
781
312Configures (or disables) the inactivity timeout. 782Configures (or disables) the inactivity timeout.
313 783
314=cut 784=item $handle->timeout_reset
315 785
316sub timeout { 786=item $handle->rtimeout_reset
787
788=item $handle->wtimeout_reset
789
790Reset the activity timeout, as if data was received or sent.
791
792These methods are cheap to call.
793
794=cut
795
796for my $dir ("", "r", "w") {
797 my $timeout = "${dir}timeout";
798 my $tw = "_${dir}tw";
799 my $on_timeout = "on_${dir}timeout";
800 my $activity = "_${dir}activity";
801 my $cb;
802
803 *$on_timeout = sub {
804 $_[0]{$on_timeout} = $_[1];
805 };
806
807 *$timeout = sub {
317 my ($self, $timeout) = @_; 808 my ($self, $new_value) = @_;
318 809
810 $new_value >= 0
811 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
812
319 $self->{timeout} = $timeout; 813 $self->{$timeout} = $new_value;
320 $self->_timeout; 814 delete $self->{$tw}; &$cb;
321} 815 };
322 816
817 *{"${dir}timeout_reset"} = sub {
818 $_[0]{$activity} = AE::now;
819 };
820
821 # main workhorse:
323# reset the timeout watcher, as neccessary 822 # reset the timeout watcher, as neccessary
324# also check for time-outs 823 # also check for time-outs
325sub _timeout { 824 $cb = sub {
326 my ($self) = @_; 825 my ($self) = @_;
327 826
328 if ($self->{timeout}) { 827 if ($self->{$timeout} && $self->{fh}) {
329 my $NOW = AnyEvent->now; 828 my $NOW = AE::now;
330 829
331 # when would the timeout trigger? 830 # when would the timeout trigger?
332 my $after = $self->{_activity} + $self->{timeout} - $NOW; 831 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
333 832
334 # now or in the past already? 833 # now or in the past already?
335 if ($after <= 0) { 834 if ($after <= 0) {
336 $self->{_activity} = $NOW; 835 $self->{$activity} = $NOW;
337 836
338 if ($self->{on_timeout}) { 837 if ($self->{$on_timeout}) {
339 $self->{on_timeout}($self); 838 $self->{$on_timeout}($self);
340 } else { 839 } else {
341 $self->_error (&Errno::ETIMEDOUT); 840 $self->_error (Errno::ETIMEDOUT);
841 }
842
843 # callback could have changed timeout value, optimise
844 return unless $self->{$timeout};
845
846 # calculate new after
847 $after = $self->{$timeout};
342 } 848 }
343 849
344 # callback could have changed timeout value, optimise 850 Scalar::Util::weaken $self;
345 return unless $self->{timeout}; 851 return unless $self; # ->error could have destroyed $self
346 852
347 # calculate new after 853 $self->{$tw} ||= AE::timer $after, 0, sub {
348 $after = $self->{timeout}; 854 delete $self->{$tw};
855 $cb->($self);
856 };
857 } else {
858 delete $self->{$tw};
349 } 859 }
350
351 Scalar::Util::weaken $self;
352 return unless $self; # ->error could have destroyed $self
353
354 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
355 delete $self->{_tw};
356 $self->_timeout;
357 });
358 } else {
359 delete $self->{_tw};
360 } 860 }
361} 861}
362 862
363############################################################################# 863#############################################################################
364 864
380=item $handle->on_drain ($cb) 880=item $handle->on_drain ($cb)
381 881
382Sets the C<on_drain> callback or clears it (see the description of 882Sets the C<on_drain> callback or clears it (see the description of
383C<on_drain> in the constructor). 883C<on_drain> in the constructor).
384 884
885This method may invoke callbacks (and therefore the handle might be
886destroyed after it returns).
887
385=cut 888=cut
386 889
387sub on_drain { 890sub on_drain {
388 my ($self, $cb) = @_; 891 my ($self, $cb) = @_;
389 892
390 $self->{on_drain} = $cb; 893 $self->{on_drain} = $cb;
391 894
392 $cb->($self) 895 $cb->($self)
393 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 896 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
394} 897}
395 898
396=item $handle->push_write ($data) 899=item $handle->push_write ($data)
397 900
398Queues the given scalar to be written. You can push as much data as you 901Queues the given scalar to be written. You can push as much data as
399want (only limited by the available memory), as C<AnyEvent::Handle> 902you want (only limited by the available memory and C<wbuf_max>), as
400buffers it independently of the kernel. 903C<AnyEvent::Handle> buffers it independently of the kernel.
904
905This method may invoke callbacks (and therefore the handle might be
906destroyed after it returns).
401 907
402=cut 908=cut
403 909
404sub _drain_wbuf { 910sub _drain_wbuf {
405 my ($self) = @_; 911 my ($self) = @_;
409 Scalar::Util::weaken $self; 915 Scalar::Util::weaken $self;
410 916
411 my $cb = sub { 917 my $cb = sub {
412 my $len = syswrite $self->{fh}, $self->{wbuf}; 918 my $len = syswrite $self->{fh}, $self->{wbuf};
413 919
414 if ($len >= 0) { 920 if (defined $len) {
415 substr $self->{wbuf}, 0, $len, ""; 921 substr $self->{wbuf}, 0, $len, "";
416 922
417 $self->{_activity} = AnyEvent->now; 923 $self->{_activity} = $self->{_wactivity} = AE::now;
418 924
419 $self->{on_drain}($self) 925 $self->{on_drain}($self)
420 if $self->{low_water_mark} >= length $self->{wbuf} 926 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
421 && $self->{on_drain}; 927 && $self->{on_drain};
422 928
423 delete $self->{_ww} unless length $self->{wbuf}; 929 delete $self->{_ww} unless length $self->{wbuf};
424 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 930 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
425 $self->_error ($!, 1); 931 $self->_error ($!, 1);
426 } 932 }
427 }; 933 };
428 934
429 # try to write data immediately 935 # try to write data immediately
430 $cb->(); 936 $cb->() unless $self->{autocork};
431 937
432 # if still data left in wbuf, we need to poll 938 # if still data left in wbuf, we need to poll
433 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 939 $self->{_ww} = AE::io $self->{fh}, 1, $cb
434 if length $self->{wbuf}; 940 if length $self->{wbuf};
941
942 if (
943 defined $self->{wbuf_max}
944 && $self->{wbuf_max} < length $self->{wbuf}
945 ) {
946 $self->_error (Errno::ENOSPC, 1), return;
947 }
435 }; 948 };
436} 949}
437 950
438our %WH; 951our %WH;
439 952
953# deprecated
440sub register_write_type($$) { 954sub register_write_type($$) {
441 $WH{$_[0]} = $_[1]; 955 $WH{$_[0]} = $_[1];
442} 956}
443 957
444sub push_write { 958sub push_write {
445 my $self = shift; 959 my $self = shift;
446 960
447 if (@_ > 1) { 961 if (@_ > 1) {
448 my $type = shift; 962 my $type = shift;
449 963
964 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
450 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 965 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
451 ->($self, @_); 966 ->($self, @_);
452 } 967 }
453 968
969 # we downgrade here to avoid hard-to-track-down bugs,
970 # and diagnose the problem earlier and better.
971
454 if ($self->{filter_w}) { 972 if ($self->{tls}) {
455 $self->{filter_w}($self, \$_[0]); 973 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
974 &_dotls ($self) if $self->{fh};
456 } else { 975 } else {
457 $self->{wbuf} .= $_[0]; 976 utf8::downgrade $self->{wbuf} .= $_[0];
458 $self->_drain_wbuf; 977 $self->_drain_wbuf if $self->{fh};
459 } 978 }
460} 979}
461 980
462=item $handle->push_write (type => @args) 981=item $handle->push_write (type => @args)
463 982
464Instead of formatting your data yourself, you can also let this module do 983Instead of formatting your data yourself, you can also let this module
465the job by specifying a type and type-specific arguments. 984do the job by specifying a type and type-specific arguments. You
985can also specify the (fully qualified) name of a package, in which
986case AnyEvent tries to load the package and then expects to find the
987C<anyevent_write_type> function inside (see "custom write types", below).
466 988
467Predefined types are (if you have ideas for additional types, feel free to 989Predefined types are (if you have ideas for additional types, feel free to
468drop by and tell us): 990drop by and tell us):
469 991
470=over 4 992=over 4
477=cut 999=cut
478 1000
479register_write_type netstring => sub { 1001register_write_type netstring => sub {
480 my ($self, $string) = @_; 1002 my ($self, $string) = @_;
481 1003
482 sprintf "%d:%s,", (length $string), $string 1004 (length $string) . ":$string,"
1005};
1006
1007=item packstring => $format, $data
1008
1009An octet string prefixed with an encoded length. The encoding C<$format>
1010uses the same format as a Perl C<pack> format, but must specify a single
1011integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1012optional C<!>, C<< < >> or C<< > >> modifier).
1013
1014=cut
1015
1016register_write_type packstring => sub {
1017 my ($self, $format, $string) = @_;
1018
1019 pack "$format/a*", $string
483}; 1020};
484 1021
485=item json => $array_or_hashref 1022=item json => $array_or_hashref
486 1023
487Encodes the given hash or array reference into a JSON object. Unless you 1024Encodes the given hash or array reference into a JSON object. Unless you
512Other languages could read single lines terminated by a newline and pass 1049Other languages could read single lines terminated by a newline and pass
513this line into their JSON decoder of choice. 1050this line into their JSON decoder of choice.
514 1051
515=cut 1052=cut
516 1053
1054sub json_coder() {
1055 eval { require JSON::XS; JSON::XS->new->utf8 }
1056 || do { require JSON; JSON->new->utf8 }
1057}
1058
517register_write_type json => sub { 1059register_write_type json => sub {
518 my ($self, $ref) = @_; 1060 my ($self, $ref) = @_;
519 1061
520 require JSON; 1062 my $json = $self->{json} ||= json_coder;
521 1063
522 $self->{json} ? $self->{json}->encode ($ref) 1064 $json->encode ($ref)
523 : JSON::encode_json ($ref)
524}; 1065};
525 1066
1067=item storable => $reference
1068
1069Freezes the given reference using L<Storable> and writes it to the
1070handle. Uses the C<nfreeze> format.
1071
1072=cut
1073
1074register_write_type storable => sub {
1075 my ($self, $ref) = @_;
1076
1077 require Storable;
1078
1079 pack "w/a*", Storable::nfreeze ($ref)
1080};
1081
526=back 1082=back
527 1083
528=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1084=item $handle->push_shutdown
529 1085
530This function (not method) lets you add your own types to C<push_write>. 1086Sometimes you know you want to close the socket after writing your data
1087before it was actually written. One way to do that is to replace your
1088C<on_drain> handler by a callback that shuts down the socket (and set
1089C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1090replaces the C<on_drain> callback with:
1091
1092 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
1093
1094This simply shuts down the write side and signals an EOF condition to the
1095the peer.
1096
1097You can rely on the normal read queue and C<on_eof> handling
1098afterwards. This is the cleanest way to close a connection.
1099
1100This method may invoke callbacks (and therefore the handle might be
1101destroyed after it returns).
1102
1103=cut
1104
1105sub push_shutdown {
1106 my ($self) = @_;
1107
1108 delete $self->{low_water_mark};
1109 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
1110}
1111
1112=item custom write types - Package::anyevent_write_type $handle, @args
1113
1114Instead of one of the predefined types, you can also specify the name of
1115a package. AnyEvent will try to load the package and then expects to find
1116a function named C<anyevent_write_type> inside. If it isn't found, it
1117progressively tries to load the parent package until it either finds the
1118function (good) or runs out of packages (bad).
1119
531Whenever the given C<type> is used, C<push_write> will invoke the code 1120Whenever the given C<type> is used, C<push_write> will the function with
532reference with the handle object and the remaining arguments. 1121the handle object and the remaining arguments.
533 1122
534The code reference is supposed to return a single octet string that will 1123The function is supposed to return a single octet string that will be
535be appended to the write buffer. 1124appended to the write buffer, so you cna mentally treat this function as a
1125"arguments to on-the-wire-format" converter.
536 1126
537Note that this is a function, and all types registered this way will be 1127Example: implement a custom write type C<join> that joins the remaining
538global, so try to use unique names. 1128arguments using the first one.
1129
1130 $handle->push_write (My::Type => " ", 1,2,3);
1131
1132 # uses the following package, which can be defined in the "My::Type" or in
1133 # the "My" modules to be auto-loaded, or just about anywhere when the
1134 # My::Type::anyevent_write_type is defined before invoking it.
1135
1136 package My::Type;
1137
1138 sub anyevent_write_type {
1139 my ($handle, $delim, @args) = @_;
1140
1141 join $delim, @args
1142 }
539 1143
540=cut 1144=cut
541 1145
542############################################################################# 1146#############################################################################
543 1147
552ways, the "simple" way, using only C<on_read> and the "complex" way, using 1156ways, the "simple" way, using only C<on_read> and the "complex" way, using
553a queue. 1157a queue.
554 1158
555In the simple case, you just install an C<on_read> callback and whenever 1159In the simple case, you just install an C<on_read> callback and whenever
556new data arrives, it will be called. You can then remove some data (if 1160new data arrives, it will be called. You can then remove some data (if
557enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 1161enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
558or not. 1162leave the data there if you want to accumulate more (e.g. when only a
1163partial message has been received so far), or change the read queue with
1164e.g. C<push_read>.
559 1165
560In the more complex case, you want to queue multiple callbacks. In this 1166In the more complex case, you want to queue multiple callbacks. In this
561case, AnyEvent::Handle will call the first queued callback each time new 1167case, AnyEvent::Handle will call the first queued callback each time new
562data arrives and removes it when it has done its job (see C<push_read>, 1168data arrives (also the first time it is queued) and remove it when it has
563below). 1169done its job (see C<push_read>, below).
564 1170
565This way you can, for example, push three line-reads, followed by reading 1171This way you can, for example, push three line-reads, followed by reading
566a chunk of data, and AnyEvent::Handle will execute them in order. 1172a chunk of data, and AnyEvent::Handle will execute them in order.
567 1173
568Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 1174Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
581 # handle xml 1187 # handle xml
582 }); 1188 });
583 }); 1189 });
584 }); 1190 });
585 1191
586Example 2: Implement a client for a protocol that replies either with 1192Example 2: Implement a client for a protocol that replies either with "OK"
587"OK" and another line or "ERROR" for one request, and 64 bytes for the 1193and another line or "ERROR" for the first request that is sent, and 64
588second request. Due tot he availability of a full queue, we can just 1194bytes for the second request. Due to the availability of a queue, we can
589pipeline sending both requests and manipulate the queue as necessary in 1195just pipeline sending both requests and manipulate the queue as necessary
590the callbacks: 1196in the callbacks.
591 1197
592 # request one 1198When the first callback is called and sees an "OK" response, it will
1199C<unshift> another line-read. This line-read will be queued I<before> the
120064-byte chunk callback.
1201
1202 # request one, returns either "OK + extra line" or "ERROR"
593 $handle->push_write ("request 1\015\012"); 1203 $handle->push_write ("request 1\015\012");
594 1204
595 # we expect "ERROR" or "OK" as response, so push a line read 1205 # we expect "ERROR" or "OK" as response, so push a line read
596 $handle->push_read (line => sub { 1206 $handle->push_read (line => sub {
597 # if we got an "OK", we have to _prepend_ another line, 1207 # if we got an "OK", we have to _prepend_ another line,
604 ... 1214 ...
605 }); 1215 });
606 } 1216 }
607 }); 1217 });
608 1218
609 # request two 1219 # request two, simply returns 64 octets
610 $handle->push_write ("request 2\015\012"); 1220 $handle->push_write ("request 2\015\012");
611 1221
612 # simply read 64 bytes, always 1222 # simply read 64 bytes, always
613 $handle->push_read (chunk => 64, sub { 1223 $handle->push_read (chunk => 64, sub {
614 my $response = $_[1]; 1224 my $response = $_[1];
620=cut 1230=cut
621 1231
622sub _drain_rbuf { 1232sub _drain_rbuf {
623 my ($self) = @_; 1233 my ($self) = @_;
624 1234
625 if ( 1235 # avoid recursion
626 defined $self->{rbuf_max}
627 && $self->{rbuf_max} < length $self->{rbuf}
628 ) {
629 return $self->_error (&Errno::ENOSPC, 1);
630 }
631
632 return if $self->{in_drain}; 1236 return if $self->{_skip_drain_rbuf};
633 local $self->{in_drain} = 1; 1237 local $self->{_skip_drain_rbuf} = 1;
634 1238
1239 while () {
1240 # we need to use a separate tls read buffer, as we must not receive data while
1241 # we are draining the buffer, and this can only happen with TLS.
1242 $self->{rbuf} .= delete $self->{_tls_rbuf}
1243 if exists $self->{_tls_rbuf};
1244
635 while (my $len = length $self->{rbuf}) { 1245 my $len = length $self->{rbuf};
636 no strict 'refs'; 1246
637 if (my $cb = shift @{ $self->{_queue} }) { 1247 if (my $cb = shift @{ $self->{_queue} }) {
638 unless ($cb->($self)) { 1248 unless ($cb->($self)) {
1249 # no progress can be made
1250 # (not enough data and no data forthcoming)
1251 $self->_error (Errno::EPIPE, 1), return
639 if ($self->{_eof}) { 1252 if $self->{_eof};
640 # no progress can be made (not enough data and no data forthcoming)
641 return $self->_error (&Errno::EPIPE, 1);
642 }
643 1253
644 unshift @{ $self->{_queue} }, $cb; 1254 unshift @{ $self->{_queue} }, $cb;
645 last; 1255 last;
646 } 1256 }
647 } elsif ($self->{on_read}) { 1257 } elsif ($self->{on_read}) {
1258 last unless $len;
1259
648 $self->{on_read}($self); 1260 $self->{on_read}($self);
649 1261
650 if ( 1262 if (
651 $len == length $self->{rbuf} # if no data has been consumed 1263 $len == length $self->{rbuf} # if no data has been consumed
652 && !@{ $self->{_queue} } # and the queue is still empty 1264 && !@{ $self->{_queue} } # and the queue is still empty
653 && $self->{on_read} # but we still have on_read 1265 && $self->{on_read} # but we still have on_read
654 ) { 1266 ) {
655 # no further data will arrive 1267 # no further data will arrive
656 # so no progress can be made 1268 # so no progress can be made
657 return $self->_error (&Errno::EPIPE, 1) 1269 $self->_error (Errno::EPIPE, 1), return
658 if $self->{_eof}; 1270 if $self->{_eof};
659 1271
660 last; # more data might arrive 1272 last; # more data might arrive
661 } 1273 }
662 } else { 1274 } else {
663 # read side becomes idle 1275 # read side becomes idle
664 delete $self->{_rw}; 1276 delete $self->{_rw} unless $self->{tls};
665 last; 1277 last;
666 } 1278 }
667 } 1279 }
668 1280
1281 if ($self->{_eof}) {
1282 $self->{on_eof}
669 $self->{on_eof}($self) 1283 ? $self->{on_eof}($self)
670 if $self->{_eof} && $self->{on_eof}; 1284 : $self->_error (0, 1, "Unexpected end-of-file");
1285
1286 return;
1287 }
1288
1289 if (
1290 defined $self->{rbuf_max}
1291 && $self->{rbuf_max} < length $self->{rbuf}
1292 ) {
1293 $self->_error (Errno::ENOSPC, 1), return;
1294 }
671 1295
672 # may need to restart read watcher 1296 # may need to restart read watcher
673 unless ($self->{_rw}) { 1297 unless ($self->{_rw}) {
674 $self->start_read 1298 $self->start_read
675 if $self->{on_read} || @{ $self->{_queue} }; 1299 if $self->{on_read} || @{ $self->{_queue} };
680 1304
681This replaces the currently set C<on_read> callback, or clears it (when 1305This replaces the currently set C<on_read> callback, or clears it (when
682the new callback is C<undef>). See the description of C<on_read> in the 1306the new callback is C<undef>). See the description of C<on_read> in the
683constructor. 1307constructor.
684 1308
1309This method may invoke callbacks (and therefore the handle might be
1310destroyed after it returns).
1311
685=cut 1312=cut
686 1313
687sub on_read { 1314sub on_read {
688 my ($self, $cb) = @_; 1315 my ($self, $cb) = @_;
689 1316
690 $self->{on_read} = $cb; 1317 $self->{on_read} = $cb;
1318 $self->_drain_rbuf if $cb;
691} 1319}
692 1320
693=item $handle->rbuf 1321=item $handle->rbuf
694 1322
695Returns the read buffer (as a modifiable lvalue). 1323Returns the read buffer (as a modifiable lvalue). You can also access the
1324read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1325much faster, and no less clean).
696 1326
697You can access the read buffer directly as the C<< ->{rbuf} >> member, if 1327The only operation allowed on the read buffer (apart from looking at it)
698you want. 1328is removing data from its beginning. Otherwise modifying or appending to
1329it is not allowed and will lead to hard-to-track-down bugs.
699 1330
700NOTE: The read buffer should only be used or modified if the C<on_read>, 1331NOTE: The read buffer should only be used or modified in the C<on_read>
701C<push_read> or C<unshift_read> methods are used. The other read methods 1332callback or when C<push_read> or C<unshift_read> are used with a single
702automatically manage the read buffer. 1333callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1334will manage the read buffer on their own.
703 1335
704=cut 1336=cut
705 1337
706sub rbuf : lvalue { 1338sub rbuf : lvalue {
707 $_[0]{rbuf} 1339 $_[0]{rbuf}
724 1356
725If enough data was available, then the callback must remove all data it is 1357If enough data was available, then the callback must remove all data it is
726interested in (which can be none at all) and return a true value. After returning 1358interested in (which can be none at all) and return a true value. After returning
727true, it will be removed from the queue. 1359true, it will be removed from the queue.
728 1360
1361These methods may invoke callbacks (and therefore the handle might be
1362destroyed after it returns).
1363
729=cut 1364=cut
730 1365
731our %RH; 1366our %RH;
732 1367
733sub register_read_type($$) { 1368sub register_read_type($$) {
739 my $cb = pop; 1374 my $cb = pop;
740 1375
741 if (@_) { 1376 if (@_) {
742 my $type = shift; 1377 my $type = shift;
743 1378
1379 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
744 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 1380 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
745 ->($self, $cb, @_); 1381 ->($self, $cb, @_);
746 } 1382 }
747 1383
748 push @{ $self->{_queue} }, $cb; 1384 push @{ $self->{_queue} }, $cb;
749 $self->_drain_rbuf; 1385 $self->_drain_rbuf;
754 my $cb = pop; 1390 my $cb = pop;
755 1391
756 if (@_) { 1392 if (@_) {
757 my $type = shift; 1393 my $type = shift;
758 1394
1395 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
759 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1396 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
760 ->($self, $cb, @_); 1397 ->($self, $cb, @_);
761 } 1398 }
762
763 1399
764 unshift @{ $self->{_queue} }, $cb; 1400 unshift @{ $self->{_queue} }, $cb;
765 $self->_drain_rbuf; 1401 $self->_drain_rbuf;
766} 1402}
767 1403
769 1405
770=item $handle->unshift_read (type => @args, $cb) 1406=item $handle->unshift_read (type => @args, $cb)
771 1407
772Instead of providing a callback that parses the data itself you can chose 1408Instead of providing a callback that parses the data itself you can chose
773between a number of predefined parsing formats, for chunks of data, lines 1409between a number of predefined parsing formats, for chunks of data, lines
774etc. 1410etc. You can also specify the (fully qualified) name of a package, in
1411which case AnyEvent tries to load the package and then expects to find the
1412C<anyevent_read_type> function inside (see "custom read types", below).
775 1413
776Predefined types are (if you have ideas for additional types, feel free to 1414Predefined types are (if you have ideas for additional types, feel free to
777drop by and tell us): 1415drop by and tell us):
778 1416
779=over 4 1417=over 4
800 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1438 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
801 1 1439 1
802 } 1440 }
803}; 1441};
804 1442
805# compatibility with older API
806sub push_read_chunk {
807 $_[0]->push_read (chunk => $_[1], $_[2]);
808}
809
810sub unshift_read_chunk {
811 $_[0]->unshift_read (chunk => $_[1], $_[2]);
812}
813
814=item line => [$eol, ]$cb->($handle, $line, $eol) 1443=item line => [$eol, ]$cb->($handle, $line, $eol)
815 1444
816The callback will be called only once a full line (including the end of 1445The callback will be called only once a full line (including the end of
817line marker, C<$eol>) has been read. This line (excluding the end of line 1446line marker, C<$eol>) has been read. This line (excluding the end of line
818marker) will be passed to the callback as second argument (C<$line>), and 1447marker) will be passed to the callback as second argument (C<$line>), and
833=cut 1462=cut
834 1463
835register_read_type line => sub { 1464register_read_type line => sub {
836 my ($self, $cb, $eol) = @_; 1465 my ($self, $cb, $eol) = @_;
837 1466
838 $eol = qr|(\015?\012)| if @_ < 3; 1467 if (@_ < 3) {
839 $eol = quotemeta $eol unless ref $eol; 1468 # this is more than twice as fast as the generic code below
840 $eol = qr|^(.*?)($eol)|s;
841
842 sub { 1469 sub {
843 $_[0]{rbuf} =~ s/$eol// or return; 1470 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
844 1471
845 $cb->($_[0], $1, $2); 1472 $cb->($_[0], $1, $2);
846 1
847 }
848};
849
850# compatibility with older API
851sub push_read_line {
852 my $self = shift;
853 $self->push_read (line => @_);
854}
855
856sub unshift_read_line {
857 my $self = shift;
858 $self->unshift_read (line => @_);
859}
860
861=item netstring => $cb->($handle, $string)
862
863A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
864
865Throws an error with C<$!> set to EBADMSG on format violations.
866
867=cut
868
869register_read_type netstring => sub {
870 my ($self, $cb) = @_;
871
872 sub {
873 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
874 if ($_[0]{rbuf} =~ /[^0-9]/) {
875 $self->_error (&Errno::EBADMSG);
876 } 1473 1
877 return;
878 } 1474 }
1475 } else {
1476 $eol = quotemeta $eol unless ref $eol;
1477 $eol = qr|^(.*?)($eol)|s;
879 1478
880 my $len = $1; 1479 sub {
1480 $_[0]{rbuf} =~ s/$eol// or return;
881 1481
882 $self->unshift_read (chunk => $len, sub { 1482 $cb->($_[0], $1, $2);
883 my $string = $_[1];
884 $_[0]->unshift_read (chunk => 1, sub {
885 if ($_[1] eq ",") {
886 $cb->($_[0], $string);
887 } else {
888 $self->_error (&Errno::EBADMSG);
889 }
890 }); 1483 1
891 }); 1484 }
892
893 1
894 } 1485 }
895}; 1486};
896 1487
897=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1488=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
898 1489
918the receive buffer when neither C<$accept> nor C<$reject> match, 1509the receive buffer when neither C<$accept> nor C<$reject> match,
919and everything preceding and including the match will be accepted 1510and everything preceding and including the match will be accepted
920unconditionally. This is useful to skip large amounts of data that you 1511unconditionally. This is useful to skip large amounts of data that you
921know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1512know cannot be matched, so that the C<$accept> or C<$reject> regex do not
922have to start matching from the beginning. This is purely an optimisation 1513have to start matching from the beginning. This is purely an optimisation
923and is usually worth only when you expect more than a few kilobytes. 1514and is usually worth it only when you expect more than a few kilobytes.
924 1515
925Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1516Example: expect a http header, which ends at C<\015\012\015\012>. Since we
926expect the header to be very large (it isn't in practise, but...), we use 1517expect the header to be very large (it isn't in practice, but...), we use
927a skip regex to skip initial portions. The skip regex is tricky in that 1518a skip regex to skip initial portions. The skip regex is tricky in that
928it only accepts something not ending in either \015 or \012, as these are 1519it only accepts something not ending in either \015 or \012, as these are
929required for the accept regex. 1520required for the accept regex.
930 1521
931 $handle->push_read (regex => 1522 $handle->push_read (regex =>
950 return 1; 1541 return 1;
951 } 1542 }
952 1543
953 # reject 1544 # reject
954 if ($reject && $$rbuf =~ $reject) { 1545 if ($reject && $$rbuf =~ $reject) {
955 $self->_error (&Errno::EBADMSG); 1546 $self->_error (Errno::EBADMSG);
956 } 1547 }
957 1548
958 # skip 1549 # skip
959 if ($skip && $$rbuf =~ $skip) { 1550 if ($skip && $$rbuf =~ $skip) {
960 $data .= substr $$rbuf, 0, $+[0], ""; 1551 $data .= substr $$rbuf, 0, $+[0], "";
962 1553
963 () 1554 ()
964 } 1555 }
965}; 1556};
966 1557
1558=item netstring => $cb->($handle, $string)
1559
1560A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1561
1562Throws an error with C<$!> set to EBADMSG on format violations.
1563
1564=cut
1565
1566register_read_type netstring => sub {
1567 my ($self, $cb) = @_;
1568
1569 sub {
1570 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1571 if ($_[0]{rbuf} =~ /[^0-9]/) {
1572 $self->_error (Errno::EBADMSG);
1573 }
1574 return;
1575 }
1576
1577 my $len = $1;
1578
1579 $self->unshift_read (chunk => $len, sub {
1580 my $string = $_[1];
1581 $_[0]->unshift_read (chunk => 1, sub {
1582 if ($_[1] eq ",") {
1583 $cb->($_[0], $string);
1584 } else {
1585 $self->_error (Errno::EBADMSG);
1586 }
1587 });
1588 });
1589
1590 1
1591 }
1592};
1593
1594=item packstring => $format, $cb->($handle, $string)
1595
1596An octet string prefixed with an encoded length. The encoding C<$format>
1597uses the same format as a Perl C<pack> format, but must specify a single
1598integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1599optional C<!>, C<< < >> or C<< > >> modifier).
1600
1601For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1602EPP uses a prefix of C<N> (4 octtes).
1603
1604Example: read a block of data prefixed by its length in BER-encoded
1605format (very efficient).
1606
1607 $handle->push_read (packstring => "w", sub {
1608 my ($handle, $data) = @_;
1609 });
1610
1611=cut
1612
1613register_read_type packstring => sub {
1614 my ($self, $cb, $format) = @_;
1615
1616 sub {
1617 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1618 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1619 or return;
1620
1621 $format = length pack $format, $len;
1622
1623 # bypass unshift if we already have the remaining chunk
1624 if ($format + $len <= length $_[0]{rbuf}) {
1625 my $data = substr $_[0]{rbuf}, $format, $len;
1626 substr $_[0]{rbuf}, 0, $format + $len, "";
1627 $cb->($_[0], $data);
1628 } else {
1629 # remove prefix
1630 substr $_[0]{rbuf}, 0, $format, "";
1631
1632 # read remaining chunk
1633 $_[0]->unshift_read (chunk => $len, $cb);
1634 }
1635
1636 1
1637 }
1638};
1639
967=item json => $cb->($handle, $hash_or_arrayref) 1640=item json => $cb->($handle, $hash_or_arrayref)
968 1641
969Reads a JSON object or array, decodes it and passes it to the callback. 1642Reads a JSON object or array, decodes it and passes it to the
1643callback. When a parse error occurs, an C<EBADMSG> error will be raised.
970 1644
971If a C<json> object was passed to the constructor, then that will be used 1645If a C<json> object was passed to the constructor, then that will be used
972for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1646for the final decode, otherwise it will create a JSON coder expecting UTF-8.
973 1647
974This read type uses the incremental parser available with JSON version 1648This read type uses the incremental parser available with JSON version
981the C<json> write type description, above, for an actual example. 1655the C<json> write type description, above, for an actual example.
982 1656
983=cut 1657=cut
984 1658
985register_read_type json => sub { 1659register_read_type json => sub {
986 my ($self, $cb, $accept, $reject, $skip) = @_; 1660 my ($self, $cb) = @_;
987 1661
988 require JSON; 1662 my $json = $self->{json} ||= json_coder;
989 1663
990 my $data; 1664 my $data;
991 my $rbuf = \$self->{rbuf}; 1665 my $rbuf = \$self->{rbuf};
992 1666
993 my $json = $self->{json} ||= JSON->new->utf8;
994
995 sub { 1667 sub {
996 my $ref = $json->incr_parse ($self->{rbuf}); 1668 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
997 1669
998 if ($ref) { 1670 if ($ref) {
999 $self->{rbuf} = $json->incr_text; 1671 $self->{rbuf} = $json->incr_text;
1000 $json->incr_text = ""; 1672 $json->incr_text = "";
1001 $cb->($self, $ref); 1673 $cb->($self, $ref);
1002 1674
1003 1 1675 1
1676 } elsif ($@) {
1677 # error case
1678 $json->incr_skip;
1679
1680 $self->{rbuf} = $json->incr_text;
1681 $json->incr_text = "";
1682
1683 $self->_error (Errno::EBADMSG);
1684
1685 ()
1004 } else { 1686 } else {
1005 $self->{rbuf} = ""; 1687 $self->{rbuf} = "";
1688
1006 () 1689 ()
1007 } 1690 }
1008 } 1691 }
1009}; 1692};
1010 1693
1694=item storable => $cb->($handle, $ref)
1695
1696Deserialises a L<Storable> frozen representation as written by the
1697C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1698data).
1699
1700Raises C<EBADMSG> error if the data could not be decoded.
1701
1702=cut
1703
1704register_read_type storable => sub {
1705 my ($self, $cb) = @_;
1706
1707 require Storable;
1708
1709 sub {
1710 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1711 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1712 or return;
1713
1714 my $format = length pack "w", $len;
1715
1716 # bypass unshift if we already have the remaining chunk
1717 if ($format + $len <= length $_[0]{rbuf}) {
1718 my $data = substr $_[0]{rbuf}, $format, $len;
1719 substr $_[0]{rbuf}, 0, $format + $len, "";
1720 $cb->($_[0], Storable::thaw ($data));
1721 } else {
1722 # remove prefix
1723 substr $_[0]{rbuf}, 0, $format, "";
1724
1725 # read remaining chunk
1726 $_[0]->unshift_read (chunk => $len, sub {
1727 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1728 $cb->($_[0], $ref);
1729 } else {
1730 $self->_error (Errno::EBADMSG);
1731 }
1732 });
1733 }
1734
1735 1
1736 }
1737};
1738
1011=back 1739=back
1012 1740
1013=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1741=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1014 1742
1015This function (not method) lets you add your own types to C<push_read>. 1743Instead of one of the predefined types, you can also specify the name
1744of a package. AnyEvent will try to load the package and then expects to
1745find a function named C<anyevent_read_type> inside. If it isn't found, it
1746progressively tries to load the parent package until it either finds the
1747function (good) or runs out of packages (bad).
1016 1748
1017Whenever the given C<type> is used, C<push_read> will invoke the code 1749Whenever this type is used, C<push_read> will invoke the function with the
1018reference with the handle object, the callback and the remaining 1750handle object, the original callback and the remaining arguments.
1019arguments.
1020 1751
1021The code reference is supposed to return a callback (usually a closure) 1752The function is supposed to return a callback (usually a closure) that
1022that works as a plain read callback (see C<< ->push_read ($cb) >>). 1753works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1754mentally treat the function as a "configurable read type to read callback"
1755converter.
1023 1756
1024It should invoke the passed callback when it is done reading (remember to 1757It should invoke the original callback when it is done reading (remember
1025pass C<$handle> as first argument as all other callbacks do that). 1758to pass C<$handle> as first argument as all other callbacks do that,
1759although there is no strict requirement on this).
1026 1760
1027Note that this is a function, and all types registered this way will be
1028global, so try to use unique names.
1029
1030For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1761For examples, see the source of this module (F<perldoc -m
1031search for C<register_read_type>)). 1762AnyEvent::Handle>, search for C<register_read_type>)).
1032 1763
1033=item $handle->stop_read 1764=item $handle->stop_read
1034 1765
1035=item $handle->start_read 1766=item $handle->start_read
1036 1767
1037In rare cases you actually do not want to read anything from the 1768In rare cases you actually do not want to read anything from the
1038socket. In this case you can call C<stop_read>. Neither C<on_read> no 1769socket. In this case you can call C<stop_read>. Neither C<on_read> nor
1039any queued callbacks will be executed then. To start reading again, call 1770any queued callbacks will be executed then. To start reading again, call
1040C<start_read>. 1771C<start_read>.
1041 1772
1042Note that AnyEvent::Handle will automatically C<start_read> for you when 1773Note that AnyEvent::Handle will automatically C<start_read> for you when
1043you change the C<on_read> callback or push/unshift a read callback, and it 1774you change the C<on_read> callback or push/unshift a read callback, and it
1044will automatically C<stop_read> for you when neither C<on_read> is set nor 1775will automatically C<stop_read> for you when neither C<on_read> is set nor
1045there are any read requests in the queue. 1776there are any read requests in the queue.
1046 1777
1778These methods will have no effect when in TLS mode (as TLS doesn't support
1779half-duplex connections).
1780
1047=cut 1781=cut
1048 1782
1049sub stop_read { 1783sub stop_read {
1050 my ($self) = @_; 1784 my ($self) = @_;
1051 1785
1052 delete $self->{_rw}; 1786 delete $self->{_rw} unless $self->{tls};
1053} 1787}
1054 1788
1055sub start_read { 1789sub start_read {
1056 my ($self) = @_; 1790 my ($self) = @_;
1057 1791
1058 unless ($self->{_rw} || $self->{_eof}) { 1792 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1059 Scalar::Util::weaken $self; 1793 Scalar::Util::weaken $self;
1060 1794
1061 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1795 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1062 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1796 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1063 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1797 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1064 1798
1065 if ($len > 0) { 1799 if ($len > 0) {
1066 $self->{_activity} = AnyEvent->now; 1800 $self->{_activity} = $self->{_ractivity} = AE::now;
1067 1801
1068 $self->{filter_r} 1802 if ($self->{tls}) {
1069 ? $self->{filter_r}($self, $rbuf) 1803 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1804
1805 &_dotls ($self);
1806 } else {
1070 : $self->_drain_rbuf; 1807 $self->_drain_rbuf;
1808 }
1809
1810 if ($len == $self->{read_size}) {
1811 $self->{read_size} *= 2;
1812 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1813 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1814 }
1071 1815
1072 } elsif (defined $len) { 1816 } elsif (defined $len) {
1073 delete $self->{_rw}; 1817 delete $self->{_rw};
1074 $self->{_eof} = 1; 1818 $self->{_eof} = 1;
1075 $self->_drain_rbuf; 1819 $self->_drain_rbuf;
1076 1820
1077 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 1821 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1078 return $self->_error ($!, 1); 1822 return $self->_error ($!, 1);
1079 } 1823 }
1080 }); 1824 };
1081 } 1825 }
1082} 1826}
1083 1827
1828our $ERROR_SYSCALL;
1829our $ERROR_WANT_READ;
1830
1831sub _tls_error {
1832 my ($self, $err) = @_;
1833
1834 return $self->_error ($!, 1)
1835 if $err == Net::SSLeay::ERROR_SYSCALL ();
1836
1837 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1838
1839 # reduce error string to look less scary
1840 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1841
1842 if ($self->{_on_starttls}) {
1843 (delete $self->{_on_starttls})->($self, undef, $err);
1844 &_freetls;
1845 } else {
1846 &_freetls;
1847 $self->_error (Errno::EPROTO, 1, $err);
1848 }
1849}
1850
1851# poll the write BIO and send the data if applicable
1852# also decode read data if possible
1853# this is basiclaly our TLS state machine
1854# more efficient implementations are possible with openssl,
1855# but not with the buggy and incomplete Net::SSLeay.
1084sub _dotls { 1856sub _dotls {
1085 my ($self) = @_; 1857 my ($self) = @_;
1086 1858
1087 my $buf; 1859 my $tmp;
1088 1860
1089 if (length $self->{_tls_wbuf}) { 1861 if (length $self->{_tls_wbuf}) {
1090 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1862 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1091 substr $self->{_tls_wbuf}, 0, $len, ""; 1863 substr $self->{_tls_wbuf}, 0, $tmp, "";
1092 } 1864 }
1093 }
1094 1865
1866 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1867 return $self->_tls_error ($tmp)
1868 if $tmp != $ERROR_WANT_READ
1869 && ($tmp != $ERROR_SYSCALL || $!);
1870 }
1871
1872 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1873 unless (length $tmp) {
1874 $self->{_on_starttls}
1875 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1876 &_freetls;
1877
1878 if ($self->{on_stoptls}) {
1879 $self->{on_stoptls}($self);
1880 return;
1881 } else {
1882 # let's treat SSL-eof as we treat normal EOF
1883 delete $self->{_rw};
1884 $self->{_eof} = 1;
1885 }
1886 }
1887
1888 $self->{_tls_rbuf} .= $tmp;
1889 $self->_drain_rbuf;
1890 $self->{tls} or return; # tls session might have gone away in callback
1891 }
1892
1893 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1894 return $self->_tls_error ($tmp)
1895 if $tmp != $ERROR_WANT_READ
1896 && ($tmp != $ERROR_SYSCALL || $!);
1897
1095 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 1898 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1096 $self->{wbuf} .= $buf; 1899 $self->{wbuf} .= $tmp;
1097 $self->_drain_wbuf; 1900 $self->_drain_wbuf;
1901 $self->{tls} or return; # tls session might have gone away in callback
1098 } 1902 }
1099 1903
1100 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1904 $self->{_on_starttls}
1101 if (length $buf) { 1905 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1102 $self->{rbuf} .= $buf; 1906 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1103 $self->_drain_rbuf;
1104 } else {
1105 # let's treat SSL-eof as we treat normal EOF
1106 $self->{_eof} = 1;
1107 $self->_shutdown;
1108 return;
1109 }
1110 }
1111
1112 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1113
1114 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1115 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1116 return $self->_error ($!, 1);
1117 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1118 return $self->_error (&Errno::EIO, 1);
1119 }
1120
1121 # all others are fine for our purposes
1122 }
1123} 1907}
1124 1908
1125=item $handle->starttls ($tls[, $tls_ctx]) 1909=item $handle->starttls ($tls[, $tls_ctx])
1126 1910
1127Instead of starting TLS negotiation immediately when the AnyEvent::Handle 1911Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1128object is created, you can also do that at a later time by calling 1912object is created, you can also do that at a later time by calling
1129C<starttls>. 1913C<starttls>.
1130 1914
1915Starting TLS is currently an asynchronous operation - when you push some
1916write data and then call C<< ->starttls >> then TLS negotiation will start
1917immediately, after which the queued write data is then sent.
1918
1131The first argument is the same as the C<tls> constructor argument (either 1919The first argument is the same as the C<tls> constructor argument (either
1132C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1920C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1133 1921
1134The second argument is the optional C<Net::SSLeay::CTX> object that is 1922The second argument is the optional C<AnyEvent::TLS> object that is used
1135used when AnyEvent::Handle has to create its own TLS connection object. 1923when AnyEvent::Handle has to create its own TLS connection object, or
1924a hash reference with C<< key => value >> pairs that will be used to
1925construct a new context.
1136 1926
1137The TLS connection object will end up in C<< $handle->{tls} >> after this 1927The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1138call and can be used or changed to your liking. Note that the handshake 1928context in C<< $handle->{tls_ctx} >> after this call and can be used or
1139might have already started when this function returns. 1929changed to your liking. Note that the handshake might have already started
1930when this function returns.
1140 1931
1932Due to bugs in OpenSSL, it might or might not be possible to do multiple
1933handshakes on the same stream. It is best to not attempt to use the
1934stream after stopping TLS.
1935
1936This method may invoke callbacks (and therefore the handle might be
1937destroyed after it returns).
1938
1141=cut 1939=cut
1940
1941our %TLS_CACHE; #TODO not yet documented, should we?
1142 1942
1143sub starttls { 1943sub starttls {
1144 my ($self, $ssl, $ctx) = @_; 1944 my ($self, $tls, $ctx) = @_;
1145 1945
1146 $self->stoptls; 1946 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1947 if $self->{tls};
1147 1948
1148 if ($ssl eq "accept") { 1949 $self->{tls} = $tls;
1149 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1950 $self->{tls_ctx} = $ctx if @_ > 2;
1150 Net::SSLeay::set_accept_state ($ssl); 1951
1151 } elsif ($ssl eq "connect") { 1952 return unless $self->{fh};
1152 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1953
1153 Net::SSLeay::set_connect_state ($ssl); 1954 require Net::SSLeay;
1955
1956 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1957 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1958
1959 $tls = delete $self->{tls};
1960 $ctx = $self->{tls_ctx};
1961
1962 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1963
1964 if ("HASH" eq ref $ctx) {
1965 require AnyEvent::TLS;
1966
1967 if ($ctx->{cache}) {
1968 my $key = $ctx+0;
1969 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1970 } else {
1971 $ctx = new AnyEvent::TLS %$ctx;
1972 }
1973 }
1154 } 1974
1155 1975 $self->{tls_ctx} = $ctx || TLS_CTX ();
1156 $self->{tls} = $ssl; 1976 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1157 1977
1158 # basically, this is deep magic (because SSL_read should have the same issues) 1978 # basically, this is deep magic (because SSL_read should have the same issues)
1159 # but the openssl maintainers basically said: "trust us, it just works". 1979 # but the openssl maintainers basically said: "trust us, it just works".
1160 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1980 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1161 # and mismaintained ssleay-module doesn't even offer them). 1981 # and mismaintained ssleay-module doesn't even offer them).
1162 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1982 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1983 #
1984 # in short: this is a mess.
1985 #
1986 # note that we do not try to keep the length constant between writes as we are required to do.
1987 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1988 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1989 # have identity issues in that area.
1163 Net::SSLeay::CTX_set_mode ($self->{tls}, 1990# Net::SSLeay::CTX_set_mode ($ssl,
1164 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1991# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1165 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1992# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1993 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1166 1994
1167 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1995 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1168 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1996 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1169 1997
1998 Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
1999
1170 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2000 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1171 2001
1172 $self->{filter_w} = sub { 2002 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1173 $_[0]{_tls_wbuf} .= ${$_[1]}; 2003 if $self->{on_starttls};
1174 &_dotls; 2004
1175 }; 2005 &_dotls; # need to trigger the initial handshake
1176 $self->{filter_r} = sub { 2006 $self->start_read; # make sure we actually do read
1177 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1178 &_dotls;
1179 };
1180} 2007}
1181 2008
1182=item $handle->stoptls 2009=item $handle->stoptls
1183 2010
1184Destroys the SSL connection, if any. Partial read or write data will be 2011Shuts down the SSL connection - this makes a proper EOF handshake by
1185lost. 2012sending a close notify to the other side, but since OpenSSL doesn't
2013support non-blocking shut downs, it is not guaranteed that you can re-use
2014the stream afterwards.
2015
2016This method may invoke callbacks (and therefore the handle might be
2017destroyed after it returns).
1186 2018
1187=cut 2019=cut
1188 2020
1189sub stoptls { 2021sub stoptls {
1190 my ($self) = @_; 2022 my ($self) = @_;
1191 2023
1192 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 2024 if ($self->{tls} && $self->{fh}) {
2025 Net::SSLeay::shutdown ($self->{tls});
1193 2026
1194 delete $self->{_rbio}; 2027 &_dotls;
1195 delete $self->{_wbio}; 2028
1196 delete $self->{_tls_wbuf}; 2029# # we don't give a shit. no, we do, but we can't. no...#d#
1197 delete $self->{filter_r}; 2030# # we, we... have to use openssl :/#d#
1198 delete $self->{filter_w}; 2031# &_freetls;#d#
2032 }
2033}
2034
2035sub _freetls {
2036 my ($self) = @_;
2037
2038 return unless $self->{tls};
2039
2040 $self->{tls_ctx}->_put_session (delete $self->{tls})
2041 if $self->{tls} > 0;
2042
2043 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1199} 2044}
1200 2045
1201sub DESTROY { 2046sub DESTROY {
1202 my $self = shift; 2047 my ($self) = @_;
1203 2048
1204 $self->stoptls; 2049 &_freetls;
2050
2051 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
2052
2053 if ($linger && length $self->{wbuf} && $self->{fh}) {
2054 my $fh = delete $self->{fh};
2055 my $wbuf = delete $self->{wbuf};
2056
2057 my @linger;
2058
2059 push @linger, AE::io $fh, 1, sub {
2060 my $len = syswrite $fh, $wbuf, length $wbuf;
2061
2062 if ($len > 0) {
2063 substr $wbuf, 0, $len, "";
2064 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
2065 @linger = (); # end
2066 }
2067 };
2068 push @linger, AE::timer $linger, 0, sub {
2069 @linger = ();
2070 };
2071 }
1205} 2072}
2073
2074=item $handle->destroy
2075
2076Shuts down the handle object as much as possible - this call ensures that
2077no further callbacks will be invoked and as many resources as possible
2078will be freed. Any method you will call on the handle object after
2079destroying it in this way will be silently ignored (and it will return the
2080empty list).
2081
2082Normally, you can just "forget" any references to an AnyEvent::Handle
2083object and it will simply shut down. This works in fatal error and EOF
2084callbacks, as well as code outside. It does I<NOT> work in a read or write
2085callback, so when you want to destroy the AnyEvent::Handle object from
2086within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
2087that case.
2088
2089Destroying the handle object in this way has the advantage that callbacks
2090will be removed as well, so if those are the only reference holders (as
2091is common), then one doesn't need to do anything special to break any
2092reference cycles.
2093
2094The handle might still linger in the background and write out remaining
2095data, as specified by the C<linger> option, however.
2096
2097=cut
2098
2099sub destroy {
2100 my ($self) = @_;
2101
2102 $self->DESTROY;
2103 %$self = ();
2104 bless $self, "AnyEvent::Handle::destroyed";
2105}
2106
2107sub AnyEvent::Handle::destroyed::AUTOLOAD {
2108 #nop
2109}
2110
2111=item $handle->destroyed
2112
2113Returns false as long as the handle hasn't been destroyed by a call to C<<
2114->destroy >>, true otherwise.
2115
2116Can be useful to decide whether the handle is still valid after some
2117callback possibly destroyed the handle. For example, C<< ->push_write >>,
2118C<< ->starttls >> and other methods can call user callbacks, which in turn
2119can destroy the handle, so work can be avoided by checking sometimes:
2120
2121 $hdl->starttls ("accept");
2122 return if $hdl->destroyed;
2123 $hdl->push_write (...
2124
2125Note that the call to C<push_write> will silently be ignored if the handle
2126has been destroyed, so often you can just ignore the possibility of the
2127handle being destroyed.
2128
2129=cut
2130
2131sub destroyed { 0 }
2132sub AnyEvent::Handle::destroyed::destroyed { 1 }
1206 2133
1207=item AnyEvent::Handle::TLS_CTX 2134=item AnyEvent::Handle::TLS_CTX
1208 2135
1209This function creates and returns the Net::SSLeay::CTX object used by 2136This function creates and returns the AnyEvent::TLS object used by default
1210default for TLS mode. 2137for TLS mode.
1211 2138
1212The context is created like this: 2139The context is created by calling L<AnyEvent::TLS> without any arguments.
1213
1214 Net::SSLeay::load_error_strings;
1215 Net::SSLeay::SSLeay_add_ssl_algorithms;
1216 Net::SSLeay::randomize;
1217
1218 my $CTX = Net::SSLeay::CTX_new;
1219
1220 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1221 2140
1222=cut 2141=cut
1223 2142
1224our $TLS_CTX; 2143our $TLS_CTX;
1225 2144
1226sub TLS_CTX() { 2145sub TLS_CTX() {
1227 $TLS_CTX || do { 2146 $TLS_CTX ||= do {
1228 require Net::SSLeay; 2147 require AnyEvent::TLS;
1229 2148
1230 Net::SSLeay::load_error_strings (); 2149 new AnyEvent::TLS
1231 Net::SSLeay::SSLeay_add_ssl_algorithms ();
1232 Net::SSLeay::randomize ();
1233
1234 $TLS_CTX = Net::SSLeay::CTX_new ();
1235
1236 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1237
1238 $TLS_CTX
1239 } 2150 }
1240} 2151}
1241 2152
1242=back 2153=back
2154
2155
2156=head1 NONFREQUENTLY ASKED QUESTIONS
2157
2158=over 4
2159
2160=item I C<undef> the AnyEvent::Handle reference inside my callback and
2161still get further invocations!
2162
2163That's because AnyEvent::Handle keeps a reference to itself when handling
2164read or write callbacks.
2165
2166It is only safe to "forget" the reference inside EOF or error callbacks,
2167from within all other callbacks, you need to explicitly call the C<<
2168->destroy >> method.
2169
2170=item Why is my C<on_eof> callback never called?
2171
2172Probably because your C<on_error> callback is being called instead: When
2173you have outstanding requests in your read queue, then an EOF is
2174considered an error as you clearly expected some data.
2175
2176To avoid this, make sure you have an empty read queue whenever your handle
2177is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
2178an C<on_read> handler that simply pushes the first read requests in the
2179queue.
2180
2181See also the next question, which explains this in a bit more detail.
2182
2183=item How can I serve requests in a loop?
2184
2185Most protocols consist of some setup phase (authentication for example)
2186followed by a request handling phase, where the server waits for requests
2187and handles them, in a loop.
2188
2189There are two important variants: The first (traditional, better) variant
2190handles requests until the server gets some QUIT command, causing it to
2191close the connection first (highly desirable for a busy TCP server). A
2192client dropping the connection is an error, which means this variant can
2193detect an unexpected detection close.
2194
2195To handle this case, always make sure you have a on-empty read queue, by
2196pushing the "read request start" handler on it:
2197
2198 # we assume a request starts with a single line
2199 my @start_request; @start_request = (line => sub {
2200 my ($hdl, $line) = @_;
2201
2202 ... handle request
2203
2204 # push next request read, possibly from a nested callback
2205 $hdl->push_read (@start_request);
2206 });
2207
2208 # auth done, now go into request handling loop
2209 # now push the first @start_request
2210 $hdl->push_read (@start_request);
2211
2212By always having an outstanding C<push_read>, the handle always expects
2213some data and raises the C<EPIPE> error when the connction is dropped
2214unexpectedly.
2215
2216The second variant is a protocol where the client can drop the connection
2217at any time. For TCP, this means that the server machine may run out of
2218sockets easier, and in general, it means you cnanot distinguish a protocl
2219failure/client crash from a normal connection close. Nevertheless, these
2220kinds of protocols are common (and sometimes even the best solution to the
2221problem).
2222
2223Having an outstanding read request at all times is possible if you ignore
2224C<EPIPE> errors, but this doesn't help with when the client drops the
2225connection during a request, which would still be an error.
2226
2227A better solution is to push the initial request read in an C<on_read>
2228callback. This avoids an error, as when the server doesn't expect data
2229(i.e. is idly waiting for the next request, an EOF will not raise an
2230error, but simply result in an C<on_eof> callback. It is also a bit slower
2231and simpler:
2232
2233 # auth done, now go into request handling loop
2234 $hdl->on_read (sub {
2235 my ($hdl) = @_;
2236
2237 # called each time we receive data but the read queue is empty
2238 # simply start read the request
2239
2240 $hdl->push_read (line => sub {
2241 my ($hdl, $line) = @_;
2242
2243 ... handle request
2244
2245 # do nothing special when the request has been handled, just
2246 # let the request queue go empty.
2247 });
2248 });
2249
2250=item I get different callback invocations in TLS mode/Why can't I pause
2251reading?
2252
2253Unlike, say, TCP, TLS connections do not consist of two independent
2254communication channels, one for each direction. Or put differently, the
2255read and write directions are not independent of each other: you cannot
2256write data unless you are also prepared to read, and vice versa.
2257
2258This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2259callback invocations when you are not expecting any read data - the reason
2260is that AnyEvent::Handle always reads in TLS mode.
2261
2262During the connection, you have to make sure that you always have a
2263non-empty read-queue, or an C<on_read> watcher. At the end of the
2264connection (or when you no longer want to use it) you can call the
2265C<destroy> method.
2266
2267=item How do I read data until the other side closes the connection?
2268
2269If you just want to read your data into a perl scalar, the easiest way
2270to achieve this is by setting an C<on_read> callback that does nothing,
2271clearing the C<on_eof> callback and in the C<on_error> callback, the data
2272will be in C<$_[0]{rbuf}>:
2273
2274 $handle->on_read (sub { });
2275 $handle->on_eof (undef);
2276 $handle->on_error (sub {
2277 my $data = delete $_[0]{rbuf};
2278 });
2279
2280The reason to use C<on_error> is that TCP connections, due to latencies
2281and packets loss, might get closed quite violently with an error, when in
2282fact all data has been received.
2283
2284It is usually better to use acknowledgements when transferring data,
2285to make sure the other side hasn't just died and you got the data
2286intact. This is also one reason why so many internet protocols have an
2287explicit QUIT command.
2288
2289=item I don't want to destroy the handle too early - how do I wait until
2290all data has been written?
2291
2292After writing your last bits of data, set the C<on_drain> callback
2293and destroy the handle in there - with the default setting of
2294C<low_water_mark> this will be called precisely when all data has been
2295written to the socket:
2296
2297 $handle->push_write (...);
2298 $handle->on_drain (sub {
2299 warn "all data submitted to the kernel\n";
2300 undef $handle;
2301 });
2302
2303If you just want to queue some data and then signal EOF to the other side,
2304consider using C<< ->push_shutdown >> instead.
2305
2306=item I want to contact a TLS/SSL server, I don't care about security.
2307
2308If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2309connect to it and then create the AnyEvent::Handle with the C<tls>
2310parameter:
2311
2312 tcp_connect $host, $port, sub {
2313 my ($fh) = @_;
2314
2315 my $handle = new AnyEvent::Handle
2316 fh => $fh,
2317 tls => "connect",
2318 on_error => sub { ... };
2319
2320 $handle->push_write (...);
2321 };
2322
2323=item I want to contact a TLS/SSL server, I do care about security.
2324
2325Then you should additionally enable certificate verification, including
2326peername verification, if the protocol you use supports it (see
2327L<AnyEvent::TLS>, C<verify_peername>).
2328
2329E.g. for HTTPS:
2330
2331 tcp_connect $host, $port, sub {
2332 my ($fh) = @_;
2333
2334 my $handle = new AnyEvent::Handle
2335 fh => $fh,
2336 peername => $host,
2337 tls => "connect",
2338 tls_ctx => { verify => 1, verify_peername => "https" },
2339 ...
2340
2341Note that you must specify the hostname you connected to (or whatever
2342"peername" the protocol needs) as the C<peername> argument, otherwise no
2343peername verification will be done.
2344
2345The above will use the system-dependent default set of trusted CA
2346certificates. If you want to check against a specific CA, add the
2347C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
2348
2349 tls_ctx => {
2350 verify => 1,
2351 verify_peername => "https",
2352 ca_file => "my-ca-cert.pem",
2353 },
2354
2355=item I want to create a TLS/SSL server, how do I do that?
2356
2357Well, you first need to get a server certificate and key. You have
2358three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
2359self-signed certificate (cheap. check the search engine of your choice,
2360there are many tutorials on the net) or c) make your own CA (tinyca2 is a
2361nice program for that purpose).
2362
2363Then create a file with your private key (in PEM format, see
2364L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
2365file should then look like this:
2366
2367 -----BEGIN RSA PRIVATE KEY-----
2368 ...header data
2369 ... lots of base64'y-stuff
2370 -----END RSA PRIVATE KEY-----
2371
2372 -----BEGIN CERTIFICATE-----
2373 ... lots of base64'y-stuff
2374 -----END CERTIFICATE-----
2375
2376The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2377specify this file as C<cert_file>:
2378
2379 tcp_server undef, $port, sub {
2380 my ($fh) = @_;
2381
2382 my $handle = new AnyEvent::Handle
2383 fh => $fh,
2384 tls => "accept",
2385 tls_ctx => { cert_file => "my-server-keycert.pem" },
2386 ...
2387
2388When you have intermediate CA certificates that your clients might not
2389know about, just append them to the C<cert_file>.
2390
2391=back
2392
1243 2393
1244=head1 SUBCLASSING AnyEvent::Handle 2394=head1 SUBCLASSING AnyEvent::Handle
1245 2395
1246In many cases, you might want to subclass AnyEvent::Handle. 2396In many cases, you might want to subclass AnyEvent::Handle.
1247 2397
1251=over 4 2401=over 4
1252 2402
1253=item * all constructor arguments become object members. 2403=item * all constructor arguments become object members.
1254 2404
1255At least initially, when you pass a C<tls>-argument to the constructor it 2405At least initially, when you pass a C<tls>-argument to the constructor it
1256will end up in C<< $handle->{tls} >>. Those members might be changes or 2406will end up in C<< $handle->{tls} >>. Those members might be changed or
1257mutated later on (for example C<tls> will hold the TLS connection object). 2407mutated later on (for example C<tls> will hold the TLS connection object).
1258 2408
1259=item * other object member names are prefixed with an C<_>. 2409=item * other object member names are prefixed with an C<_>.
1260 2410
1261All object members not explicitly documented (internal use) are prefixed 2411All object members not explicitly documented (internal use) are prefixed
1264 2414
1265=item * all members not documented here and not prefixed with an underscore 2415=item * all members not documented here and not prefixed with an underscore
1266are free to use in subclasses. 2416are free to use in subclasses.
1267 2417
1268Of course, new versions of AnyEvent::Handle may introduce more "public" 2418Of course, new versions of AnyEvent::Handle may introduce more "public"
1269member variables, but thats just life, at least it is documented. 2419member variables, but that's just life. At least it is documented.
1270 2420
1271=back 2421=back
1272 2422
1273=head1 AUTHOR 2423=head1 AUTHOR
1274 2424

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