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Revision 1.214 by root, Sun Jan 16 17:12:27 2011 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 = 4.14;
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 (unlike read queue callbacks, this 189and no read request is in the queue (unlike read queue callbacks, this
111callback will only be called when at least one octet of data is in the 190callback will only be called when at least one octet of data is in the
112read buffer). 191read buffer).
113 192
114To 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 >>
115method or access the C<$handle->{rbuf}> member directly. 194method or access the C<< $handle->{rbuf} >> member directly. Note that you
195must not enlarge or modify the read buffer, you can only remove data at
196the beginning from it.
116 197
198You can also call C<< ->push_read (...) >> or any other function that
199modifies the read queue. Or do both. Or ...
200
117When an EOF condition is detected then AnyEvent::Handle will first try to 201When an EOF condition is detected, AnyEvent::Handle will first try to
118feed all the remaining data to the queued callbacks and C<on_read> before 202feed all the remaining data to the queued callbacks and C<on_read> before
119calling the C<on_eof> callback. If no progress can be made, then a fatal 203calling the C<on_eof> callback. If no progress can be made, then a fatal
120error will be raised (with C<$!> set to C<EPIPE>). 204error will be raised (with C<$!> set to C<EPIPE>).
121 205
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
122=item on_drain => $cb->($handle) 227=item on_drain => $cb->($handle)
123 228
124This 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
125(or when the callback is set and the buffer is empty already). 230(or immediately if the buffer is empty already).
126 231
127To append to the write buffer, use the C<< ->push_write >> method. 232To append to the write buffer, use the C<< ->push_write >> method.
128 233
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
129=item timeout => $fractional_seconds 240=item timeout => $fractional_seconds
130 241
242=item rtimeout => $fractional_seconds
243
244=item wtimeout => $fractional_seconds
245
131If non-zero, then this enables an "inactivity" timeout: whenever this many 246If non-zero, then these enables an "inactivity" timeout: whenever this
132seconds pass without a successful read or write on the underlying file 247many seconds pass without a successful read or write on the underlying
133handle, 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
134missing, 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).
135 251
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
136Note that timeout processing is also active when you currently do not have 258Note that timeout processing is active even when you do not have
137any 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
138idle then you should disable the timout temporarily or ignore the timeout 260idle then you should disable the timeout temporarily or ignore the timeout
139in the C<on_timeout> callback. 261in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
262restart the timeout.
140 263
141Zero (the default) disables this timeout. 264Zero (the default) disables this timeout.
142 265
143=item on_timeout => $cb->($handle) 266=item on_timeout => $cb->($handle)
144 267
148 271
149=item rbuf_max => <bytes> 272=item rbuf_max => <bytes>
150 273
151If 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>)
152when 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
153avoid denial-of-service attacks. 276avoid some forms of denial-of-service attacks.
154 277
155For example, a server accepting connections from untrusted sources should 278For example, a server accepting connections from untrusted sources should
156be 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
157(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
158amount 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
159isn't finished). 282isn't finished).
160 283
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
161=item read_size => <bytes> 357=item read_size => <bytes>
162 358
163The 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
164during 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.
165 370
166=item low_water_mark => <bytes> 371=item low_water_mark => <bytes>
167 372
168Sets 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
169buffer: 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
170considered empty. 375considered empty.
171 376
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
172=item linger => <seconds> 382=item linger => <seconds>
173 383
174If non-zero (default: C<3600>), then the destructor of the 384If this is non-zero (default: C<3600>), the destructor of the
175AnyEvent::Handle object will check wether there is still outstanding write 385AnyEvent::Handle object will check whether there is still outstanding
176data and will install a watcher that will write out this data. No errors 386write data and will install a watcher that will write this data to the
177will be reported (this mostly matches how the operating system treats 387socket. No errors will be reported (this mostly matches how the operating
178outstanding data at socket close time). 388system treats outstanding data at socket close time).
179 389
180This will not work for partial TLS data that could not yet been 390This will not work for partial TLS data that could not be encoded
181encoded. This data will be lost. 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>.
182 403
183=item tls => "accept" | "connect" | Net::SSLeay::SSL object 404=item tls => "accept" | "connect" | Net::SSLeay::SSL object
184 405
185When this parameter is given, it enables TLS (SSL) mode, that means it 406When this parameter is given, it enables TLS (SSL) mode, that means
186will start making tls handshake and will transparently encrypt/decrypt 407AnyEvent will start a TLS handshake as soon as the connection has been
187data. 408established and will transparently encrypt/decrypt data afterwards.
409
410All TLS protocol errors will be signalled as C<EPROTO>, with an
411appropriate error message.
188 412
189TLS mode requires Net::SSLeay to be installed (it will be loaded 413TLS mode requires Net::SSLeay to be installed (it will be loaded
190automatically 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.
191 417
192For 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
193connection, use C<connect> mode. 419C<accept>, and for the TLS client side of a connection, use C<connect>
420mode.
194 421
195You can also provide your own TLS connection object, but you have 422You can also provide your own TLS connection object, but you have
196to 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>
197or 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
198AnyEvent::Handle. 425AnyEvent::Handle. Also, this module will take ownership of this connection
426object.
199 427
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
200See 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.
201 438
202=item tls_ctx => $ssl_ctx 439=item tls_ctx => $anyevent_tls
203 440
204Use 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
205(unless a connection object was specified directly). If this parameter is 442(unless a connection object was specified directly). If this
206missing, 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.
207 481
208=item json => JSON or JSON::XS object 482=item json => JSON or JSON::XS object
209 483
210This 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.
211 485
212If 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
213suitable 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.
214 489
215Note 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
216use this functionality, as AnyEvent does not have a dependency itself. 491use this functionality, as AnyEvent does not have a dependency itself.
217 492
218=item filter_r => $cb
219
220=item filter_w => $cb
221
222These exist, but are undocumented at this time.
223
224=back 493=back
225 494
226=cut 495=cut
227 496
228sub new { 497sub new {
229 my $class = shift; 498 my $class = shift;
230
231 my $self = bless { @_ }, $class; 499 my $self = bless { @_ }, $class;
232 500
233 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 501 if ($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;
234 572
235 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 573 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
236 574
237 if ($self->{tls}) { 575 $self->{_activity} =
238 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
239 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 592 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
240 } 593 if $self->{tls};
241 594
242 $self->{_activity} = AnyEvent->now;
243 $self->_timeout;
244
245 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 595 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
246 596
247 $self 597 $self->start_read
248} 598 if $self->{on_read} || @{ $self->{_queue} };
249 599
250sub _shutdown { 600 $self->_drain_wbuf;
251 my ($self) = @_;
252
253 delete $self->{_tw};
254 delete $self->{_rw};
255 delete $self->{_ww};
256 delete $self->{fh};
257
258 $self->stoptls;
259} 601}
260 602
261sub _error { 603sub _error {
262 my ($self, $errno, $fatal) = @_; 604 my ($self, $errno, $fatal, $message) = @_;
263
264 $self->_shutdown
265 if $fatal;
266 605
267 $! = $errno; 606 $! = $errno;
607 $message ||= "$!";
268 608
269 if ($self->{on_error}) { 609 if ($self->{on_error}) {
270 $self->{on_error}($self, $fatal); 610 $self->{on_error}($self, $fatal, $message);
271 } else { 611 $self->destroy if $fatal;
612 } elsif ($self->{fh} || $self->{connect}) {
613 $self->destroy;
272 Carp::croak "AnyEvent::Handle uncaught error: $!"; 614 Carp::croak "AnyEvent::Handle uncaught error: $message";
273 } 615 }
274} 616}
275 617
276=item $fh = $handle->fh 618=item $fh = $handle->fh
277 619
278This 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.
279 621
280=cut 622=cut
281 623
282sub fh { $_[0]{fh} } 624sub fh { $_[0]{fh} }
283 625
301 $_[0]{on_eof} = $_[1]; 643 $_[0]{on_eof} = $_[1];
302} 644}
303 645
304=item $handle->on_timeout ($cb) 646=item $handle->on_timeout ($cb)
305 647
306Replace the current C<on_timeout> callback, or disables the callback 648=item $handle->on_rtimeout ($cb)
307(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
308argument.
309 649
310=cut 650=item $handle->on_wtimeout ($cb)
311 651
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
312sub on_timeout { 752sub on_stoptls {
313 $_[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];
314} 772}
315 773
316############################################################################# 774#############################################################################
317 775
318=item $handle->timeout ($seconds) 776=item $handle->timeout ($seconds)
319 777
778=item $handle->rtimeout ($seconds)
779
780=item $handle->wtimeout ($seconds)
781
320Configures (or disables) the inactivity timeout. 782Configures (or disables) the inactivity timeout.
321 783
322=cut 784=item $handle->timeout_reset
323 785
324sub 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 {
325 my ($self, $timeout) = @_; 808 my ($self, $new_value) = @_;
326 809
810 $new_value >= 0
811 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
812
327 $self->{timeout} = $timeout; 813 $self->{$timeout} = $new_value;
328 $self->_timeout; 814 delete $self->{$tw}; &$cb;
329} 815 };
330 816
817 *{"${dir}timeout_reset"} = sub {
818 $_[0]{$activity} = AE::now;
819 };
820
821 # main workhorse:
331# reset the timeout watcher, as neccessary 822 # reset the timeout watcher, as neccessary
332# also check for time-outs 823 # also check for time-outs
333sub _timeout { 824 $cb = sub {
334 my ($self) = @_; 825 my ($self) = @_;
335 826
336 if ($self->{timeout}) { 827 if ($self->{$timeout} && $self->{fh}) {
337 my $NOW = AnyEvent->now; 828 my $NOW = AE::now;
338 829
339 # when would the timeout trigger? 830 # when would the timeout trigger?
340 my $after = $self->{_activity} + $self->{timeout} - $NOW; 831 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
341 832
342 # now or in the past already? 833 # now or in the past already?
343 if ($after <= 0) { 834 if ($after <= 0) {
344 $self->{_activity} = $NOW; 835 $self->{$activity} = $NOW;
345 836
346 if ($self->{on_timeout}) { 837 if ($self->{$on_timeout}) {
347 $self->{on_timeout}($self); 838 $self->{$on_timeout}($self);
348 } else { 839 } else {
349 $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};
350 } 848 }
351 849
352 # callback could have changed timeout value, optimise 850 Scalar::Util::weaken $self;
353 return unless $self->{timeout}; 851 return unless $self; # ->error could have destroyed $self
354 852
355 # calculate new after 853 $self->{$tw} ||= AE::timer $after, 0, sub {
356 $after = $self->{timeout}; 854 delete $self->{$tw};
855 $cb->($self);
856 };
857 } else {
858 delete $self->{$tw};
357 } 859 }
358
359 Scalar::Util::weaken $self;
360 return unless $self; # ->error could have destroyed $self
361
362 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
363 delete $self->{_tw};
364 $self->_timeout;
365 });
366 } else {
367 delete $self->{_tw};
368 } 860 }
369} 861}
370 862
371############################################################################# 863#############################################################################
372 864
388=item $handle->on_drain ($cb) 880=item $handle->on_drain ($cb)
389 881
390Sets 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
391C<on_drain> in the constructor). 883C<on_drain> in the constructor).
392 884
885This method may invoke callbacks (and therefore the handle might be
886destroyed after it returns).
887
393=cut 888=cut
394 889
395sub on_drain { 890sub on_drain {
396 my ($self, $cb) = @_; 891 my ($self, $cb) = @_;
397 892
398 $self->{on_drain} = $cb; 893 $self->{on_drain} = $cb;
399 894
400 $cb->($self) 895 $cb->($self)
401 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 896 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
402} 897}
403 898
404=item $handle->push_write ($data) 899=item $handle->push_write ($data)
405 900
406Queues 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
407want (only limited by the available memory), as C<AnyEvent::Handle> 902you want (only limited by the available memory and C<wbuf_max>), as
408buffers 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).
409 907
410=cut 908=cut
411 909
412sub _drain_wbuf { 910sub _drain_wbuf {
413 my ($self) = @_; 911 my ($self) = @_;
417 Scalar::Util::weaken $self; 915 Scalar::Util::weaken $self;
418 916
419 my $cb = sub { 917 my $cb = sub {
420 my $len = syswrite $self->{fh}, $self->{wbuf}; 918 my $len = syswrite $self->{fh}, $self->{wbuf};
421 919
422 if ($len >= 0) { 920 if (defined $len) {
423 substr $self->{wbuf}, 0, $len, ""; 921 substr $self->{wbuf}, 0, $len, "";
424 922
425 $self->{_activity} = AnyEvent->now; 923 $self->{_activity} = $self->{_wactivity} = AE::now;
426 924
427 $self->{on_drain}($self) 925 $self->{on_drain}($self)
428 if $self->{low_water_mark} >= length $self->{wbuf} 926 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
429 && $self->{on_drain}; 927 && $self->{on_drain};
430 928
431 delete $self->{_ww} unless length $self->{wbuf}; 929 delete $self->{_ww} unless length $self->{wbuf};
432 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 930 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
433 $self->_error ($!, 1); 931 $self->_error ($!, 1);
434 } 932 }
435 }; 933 };
436 934
437 # try to write data immediately 935 # try to write data immediately
438 $cb->(); 936 $cb->() unless $self->{autocork};
439 937
440 # if still data left in wbuf, we need to poll 938 # if still data left in wbuf, we need to poll
441 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 939 $self->{_ww} = AE::io $self->{fh}, 1, $cb
442 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 }
443 }; 948 };
444} 949}
445 950
446our %WH; 951our %WH;
447 952
953# deprecated
448sub register_write_type($$) { 954sub register_write_type($$) {
449 $WH{$_[0]} = $_[1]; 955 $WH{$_[0]} = $_[1];
450} 956}
451 957
452sub push_write { 958sub push_write {
453 my $self = shift; 959 my $self = shift;
454 960
455 if (@_ > 1) { 961 if (@_ > 1) {
456 my $type = shift; 962 my $type = shift;
457 963
964 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
458 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 965 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
459 ->($self, @_); 966 ->($self, @_);
460 } 967 }
461 968
969 # we downgrade here to avoid hard-to-track-down bugs,
970 # and diagnose the problem earlier and better.
971
462 if ($self->{filter_w}) { 972 if ($self->{tls}) {
463 $self->{filter_w}($self, \$_[0]); 973 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
974 &_dotls ($self) if $self->{fh};
464 } else { 975 } else {
465 $self->{wbuf} .= $_[0]; 976 utf8::downgrade $self->{wbuf} .= $_[0];
466 $self->_drain_wbuf; 977 $self->_drain_wbuf if $self->{fh};
467 } 978 }
468} 979}
469 980
470=item $handle->push_write (type => @args) 981=item $handle->push_write (type => @args)
471 982
472Instead of formatting your data yourself, you can also let this module do 983Instead of formatting your data yourself, you can also let this module
473the job by specifying a type and type-specific arguments. 984do the job by specifying a type and type-specific arguments. You
985can also specify the (fully qualified) name of a package, in which
986case AnyEvent tries to load the package and then expects to find the
987C<anyevent_write_type> function inside (see "custom write types", below).
474 988
475Predefined types are (if you have ideas for additional types, feel free to 989Predefined types are (if you have ideas for additional types, feel free to
476drop by and tell us): 990drop by and tell us):
477 991
478=over 4 992=over 4
485=cut 999=cut
486 1000
487register_write_type netstring => sub { 1001register_write_type netstring => sub {
488 my ($self, $string) = @_; 1002 my ($self, $string) = @_;
489 1003
490 sprintf "%d:%s,", (length $string), $string 1004 (length $string) . ":$string,"
491}; 1005};
492 1006
493=item packstring => $format, $data 1007=item packstring => $format, $data
494 1008
495An octet string prefixed with an encoded length. The encoding C<$format> 1009An octet string prefixed with an encoded length. The encoding C<$format>
500=cut 1014=cut
501 1015
502register_write_type packstring => sub { 1016register_write_type packstring => sub {
503 my ($self, $format, $string) = @_; 1017 my ($self, $format, $string) = @_;
504 1018
505 pack "$format/a", $string 1019 pack "$format/a*", $string
506}; 1020};
507 1021
508=item json => $array_or_hashref 1022=item json => $array_or_hashref
509 1023
510Encodes the given hash or array reference into a JSON object. Unless you 1024Encodes the given hash or array reference into a JSON object. Unless you
535Other languages could read single lines terminated by a newline and pass 1049Other languages could read single lines terminated by a newline and pass
536this line into their JSON decoder of choice. 1050this line into their JSON decoder of choice.
537 1051
538=cut 1052=cut
539 1053
1054sub json_coder() {
1055 eval { require JSON::XS; JSON::XS->new->utf8 }
1056 || do { require JSON; JSON->new->utf8 }
1057}
1058
540register_write_type json => sub { 1059register_write_type json => sub {
541 my ($self, $ref) = @_; 1060 my ($self, $ref) = @_;
542 1061
543 require JSON; 1062 my $json = $self->{json} ||= json_coder;
544 1063
545 $self->{json} ? $self->{json}->encode ($ref) 1064 $json->encode ($ref)
546 : JSON::encode_json ($ref)
547}; 1065};
548 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
549=back 1082=back
550 1083
551=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1084=item $handle->push_shutdown
552 1085
553This 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 $_[0]{fh}, 1 }
1093
1094This simply shuts down the write side and signals an EOF condition to the
1095the peer.
1096
1097You can rely on the normal read queue and C<on_eof> handling
1098afterwards. This is the cleanest way to close a connection.
1099
1100This method may invoke callbacks (and therefore the handle might be
1101destroyed after it returns).
1102
1103=cut
1104
1105sub push_shutdown {
1106 my ($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
554Whenever 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
555reference with the handle object and the remaining arguments. 1121the handle object and the remaining arguments.
556 1122
557The 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
558be 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.
559 1126
560Note 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
561global, 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 }
562 1143
563=cut 1144=cut
564 1145
565############################################################################# 1146#############################################################################
566 1147
575ways, 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
576a queue. 1157a queue.
577 1158
578In 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
579new 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
580enough 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
581or 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>.
582 1165
583In 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
584case, AnyEvent::Handle will call the first queued callback each time new 1167case, AnyEvent::Handle will call the first queued callback each time new
585data arrives (also the first time it is queued) and removes it when it has 1168data arrives (also the first time it is queued) and remove it when it has
586done its job (see C<push_read>, below). 1169done its job (see C<push_read>, below).
587 1170
588This 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
589a chunk of data, and AnyEvent::Handle will execute them in order. 1172a chunk of data, and AnyEvent::Handle will execute them in order.
590 1173
604 # handle xml 1187 # handle xml
605 }); 1188 });
606 }); 1189 });
607 }); 1190 });
608 1191
609Example 2: Implement a client for a protocol that replies either with 1192Example 2: Implement a client for a protocol that replies either with "OK"
610"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
611second 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
612pipeline sending both requests and manipulate the queue as necessary in 1195just pipeline sending both requests and manipulate the queue as necessary
613the callbacks: 1196in the callbacks.
614 1197
615 # 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"
616 $handle->push_write ("request 1\015\012"); 1203 $handle->push_write ("request 1\015\012");
617 1204
618 # 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
619 $handle->push_read (line => sub { 1206 $handle->push_read (line => sub {
620 # if we got an "OK", we have to _prepend_ another line, 1207 # if we got an "OK", we have to _prepend_ another line,
627 ... 1214 ...
628 }); 1215 });
629 } 1216 }
630 }); 1217 });
631 1218
632 # request two 1219 # request two, simply returns 64 octets
633 $handle->push_write ("request 2\015\012"); 1220 $handle->push_write ("request 2\015\012");
634 1221
635 # simply read 64 bytes, always 1222 # simply read 64 bytes, always
636 $handle->push_read (chunk => 64, sub { 1223 $handle->push_read (chunk => 64, sub {
637 my $response = $_[1]; 1224 my $response = $_[1];
643=cut 1230=cut
644 1231
645sub _drain_rbuf { 1232sub _drain_rbuf {
646 my ($self) = @_; 1233 my ($self) = @_;
647 1234
1235 # avoid recursion
1236 return if $self->{_skip_drain_rbuf};
648 local $self->{_in_drain} = 1; 1237 local $self->{_skip_drain_rbuf} = 1;
649
650 if (
651 defined $self->{rbuf_max}
652 && $self->{rbuf_max} < length $self->{rbuf}
653 ) {
654 return $self->_error (&Errno::ENOSPC, 1);
655 }
656 1238
657 while () { 1239 while () {
658 no strict 'refs'; 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};
659 1244
660 my $len = length $self->{rbuf}; 1245 my $len = length $self->{rbuf};
661 1246
662 if (my $cb = shift @{ $self->{_queue} }) { 1247 if (my $cb = shift @{ $self->{_queue} }) {
663 unless ($cb->($self)) { 1248 unless ($cb->($self)) {
664 if ($self->{_eof}) { 1249 # no progress can be made
665 # no progress can be made (not enough data and no data forthcoming) 1250 # (not enough data and no data forthcoming)
666 $self->_error (&Errno::EPIPE, 1), last; 1251 $self->_error (Errno::EPIPE, 1), return
667 } 1252 if $self->{_eof};
668 1253
669 unshift @{ $self->{_queue} }, $cb; 1254 unshift @{ $self->{_queue} }, $cb;
670 last; 1255 last;
671 } 1256 }
672 } elsif ($self->{on_read}) { 1257 } elsif ($self->{on_read}) {
679 && !@{ $self->{_queue} } # and the queue is still empty 1264 && !@{ $self->{_queue} } # and the queue is still empty
680 && $self->{on_read} # but we still have on_read 1265 && $self->{on_read} # but we still have on_read
681 ) { 1266 ) {
682 # no further data will arrive 1267 # no further data will arrive
683 # so no progress can be made 1268 # so no progress can be made
684 $self->_error (&Errno::EPIPE, 1), last 1269 $self->_error (Errno::EPIPE, 1), return
685 if $self->{_eof}; 1270 if $self->{_eof};
686 1271
687 last; # more data might arrive 1272 last; # more data might arrive
688 } 1273 }
689 } else { 1274 } else {
690 # read side becomes idle 1275 # read side becomes idle
691 delete $self->{_rw}; 1276 delete $self->{_rw} unless $self->{tls};
692 last; 1277 last;
693 } 1278 }
694 } 1279 }
695 1280
1281 if ($self->{_eof}) {
1282 $self->{on_eof}
696 $self->{on_eof}($self) 1283 ? $self->{on_eof}($self)
697 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 $self->_error (Errno::ENOSPC, 1), return;
1294 }
698 1295
699 # may need to restart read watcher 1296 # may need to restart read watcher
700 unless ($self->{_rw}) { 1297 unless ($self->{_rw}) {
701 $self->start_read 1298 $self->start_read
702 if $self->{on_read} || @{ $self->{_queue} }; 1299 if $self->{on_read} || @{ $self->{_queue} };
707 1304
708This replaces the currently set C<on_read> callback, or clears it (when 1305This replaces the currently set C<on_read> callback, or clears it (when
709the new callback is C<undef>). See the description of C<on_read> in the 1306the new callback is C<undef>). See the description of C<on_read> in the
710constructor. 1307constructor.
711 1308
1309This method may invoke callbacks (and therefore the handle might be
1310destroyed after it returns).
1311
712=cut 1312=cut
713 1313
714sub on_read { 1314sub on_read {
715 my ($self, $cb) = @_; 1315 my ($self, $cb) = @_;
716 1316
717 $self->{on_read} = $cb; 1317 $self->{on_read} = $cb;
718 $self->_drain_rbuf if $cb && !$self->{_in_drain}; 1318 $self->_drain_rbuf if $cb;
719} 1319}
720 1320
721=item $handle->rbuf 1321=item $handle->rbuf
722 1322
723Returns 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).
724 1326
725You 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)
726you 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.
727 1330
728NOTE: 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>
729C<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
730automatically 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.
731 1335
732=cut 1336=cut
733 1337
734sub rbuf : lvalue { 1338sub rbuf : lvalue {
735 $_[0]{rbuf} 1339 $_[0]{rbuf}
752 1356
753If 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
754interested 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
755true, it will be removed from the queue. 1359true, it will be removed from the queue.
756 1360
1361These methods may invoke callbacks (and therefore the handle might be
1362destroyed after it returns).
1363
757=cut 1364=cut
758 1365
759our %RH; 1366our %RH;
760 1367
761sub register_read_type($$) { 1368sub register_read_type($$) {
767 my $cb = pop; 1374 my $cb = pop;
768 1375
769 if (@_) { 1376 if (@_) {
770 my $type = shift; 1377 my $type = shift;
771 1378
1379 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
772 $cb = ($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")
773 ->($self, $cb, @_); 1381 ->($self, $cb, @_);
774 } 1382 }
775 1383
776 push @{ $self->{_queue} }, $cb; 1384 push @{ $self->{_queue} }, $cb;
777 $self->_drain_rbuf unless $self->{_in_drain}; 1385 $self->_drain_rbuf;
778} 1386}
779 1387
780sub unshift_read { 1388sub unshift_read {
781 my $self = shift; 1389 my $self = shift;
782 my $cb = pop; 1390 my $cb = pop;
783 1391
784 if (@_) { 1392 if (@_) {
785 my $type = shift; 1393 my $type = shift;
786 1394
1395 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
787 $cb = ($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")
788 ->($self, $cb, @_); 1397 ->($self, $cb, @_);
789 } 1398 }
790 1399
791
792 unshift @{ $self->{_queue} }, $cb; 1400 unshift @{ $self->{_queue} }, $cb;
793 $self->_drain_rbuf unless $self->{_in_drain}; 1401 $self->_drain_rbuf;
794} 1402}
795 1403
796=item $handle->push_read (type => @args, $cb) 1404=item $handle->push_read (type => @args, $cb)
797 1405
798=item $handle->unshift_read (type => @args, $cb) 1406=item $handle->unshift_read (type => @args, $cb)
799 1407
800Instead 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
801between a number of predefined parsing formats, for chunks of data, lines 1409between a number of predefined parsing formats, for chunks of data, lines
802etc. 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).
803 1413
804Predefined 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
805drop by and tell us): 1415drop by and tell us):
806 1416
807=over 4 1417=over 4
828 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1438 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
829 1 1439 1
830 } 1440 }
831}; 1441};
832 1442
833# compatibility with older API
834sub push_read_chunk {
835 $_[0]->push_read (chunk => $_[1], $_[2]);
836}
837
838sub unshift_read_chunk {
839 $_[0]->unshift_read (chunk => $_[1], $_[2]);
840}
841
842=item line => [$eol, ]$cb->($handle, $line, $eol) 1443=item line => [$eol, ]$cb->($handle, $line, $eol)
843 1444
844The callback will be called only once a full line (including the end of 1445The callback will be called only once a full line (including the end of
845line marker, C<$eol>) has been read. This line (excluding the end of line 1446line marker, C<$eol>) has been read. This line (excluding the end of line
846marker) will be passed to the callback as second argument (C<$line>), and 1447marker) will be passed to the callback as second argument (C<$line>), and
861=cut 1462=cut
862 1463
863register_read_type line => sub { 1464register_read_type line => sub {
864 my ($self, $cb, $eol) = @_; 1465 my ($self, $cb, $eol) = @_;
865 1466
866 $eol = qr|(\015?\012)| if @_ < 3; 1467 if (@_ < 3) {
1468 # this is more than twice as fast as the generic code below
1469 sub {
1470 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
1471
1472 $cb->($_[0], $1, $2);
1473 1
1474 }
1475 } else {
867 $eol = quotemeta $eol unless ref $eol; 1476 $eol = quotemeta $eol unless ref $eol;
868 $eol = qr|^(.*?)($eol)|s; 1477 $eol = qr|^(.*?)($eol)|s;
869 1478
870 sub { 1479 sub {
871 $_[0]{rbuf} =~ s/$eol// or return; 1480 $_[0]{rbuf} =~ s/$eol// or return;
872 1481
873 $cb->($_[0], $1, $2); 1482 $cb->($_[0], $1, $2);
1483 1
874 1 1484 }
875 } 1485 }
876}; 1486};
877
878# compatibility with older API
879sub push_read_line {
880 my $self = shift;
881 $self->push_read (line => @_);
882}
883
884sub unshift_read_line {
885 my $self = shift;
886 $self->unshift_read (line => @_);
887}
888 1487
889=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1488=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
890 1489
891Makes a regex match against the regex object C<$accept> and returns 1490Makes a regex match against the regex object C<$accept> and returns
892everything up to and including the match. 1491everything up to and including the match.
910the receive buffer when neither C<$accept> nor C<$reject> match, 1509the receive buffer when neither C<$accept> nor C<$reject> match,
911and everything preceding and including the match will be accepted 1510and everything preceding and including the match will be accepted
912unconditionally. This is useful to skip large amounts of data that you 1511unconditionally. This is useful to skip large amounts of data that you
913know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1512know cannot be matched, so that the C<$accept> or C<$reject> regex do not
914have to start matching from the beginning. This is purely an optimisation 1513have to start matching from the beginning. This is purely an optimisation
915and 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.
916 1515
917Example: 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
918expect 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
919a 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
920it 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
921required for the accept regex. 1520required for the accept regex.
922 1521
923 $handle->push_read (regex => 1522 $handle->push_read (regex =>
942 return 1; 1541 return 1;
943 } 1542 }
944 1543
945 # reject 1544 # reject
946 if ($reject && $$rbuf =~ $reject) { 1545 if ($reject && $$rbuf =~ $reject) {
947 $self->_error (&Errno::EBADMSG); 1546 $self->_error (Errno::EBADMSG);
948 } 1547 }
949 1548
950 # skip 1549 # skip
951 if ($skip && $$rbuf =~ $skip) { 1550 if ($skip && $$rbuf =~ $skip) {
952 $data .= substr $$rbuf, 0, $+[0], ""; 1551 $data .= substr $$rbuf, 0, $+[0], "";
968 my ($self, $cb) = @_; 1567 my ($self, $cb) = @_;
969 1568
970 sub { 1569 sub {
971 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1570 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
972 if ($_[0]{rbuf} =~ /[^0-9]/) { 1571 if ($_[0]{rbuf} =~ /[^0-9]/) {
973 $self->_error (&Errno::EBADMSG); 1572 $self->_error (Errno::EBADMSG);
974 } 1573 }
975 return; 1574 return;
976 } 1575 }
977 1576
978 my $len = $1; 1577 my $len = $1;
981 my $string = $_[1]; 1580 my $string = $_[1];
982 $_[0]->unshift_read (chunk => 1, sub { 1581 $_[0]->unshift_read (chunk => 1, sub {
983 if ($_[1] eq ",") { 1582 if ($_[1] eq ",") {
984 $cb->($_[0], $string); 1583 $cb->($_[0], $string);
985 } else { 1584 } else {
986 $self->_error (&Errno::EBADMSG); 1585 $self->_error (Errno::EBADMSG);
987 } 1586 }
988 }); 1587 });
989 }); 1588 });
990 1589
991 1 1590 1
997An octet string prefixed with an encoded length. The encoding C<$format> 1596An octet string prefixed with an encoded length. The encoding C<$format>
998uses the same format as a Perl C<pack> format, but must specify a single 1597uses the same format as a Perl C<pack> format, but must specify a single
999integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1598integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1000optional C<!>, C<< < >> or C<< > >> modifier). 1599optional C<!>, C<< < >> or C<< > >> modifier).
1001 1600
1002DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1601For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1602EPP uses a prefix of C<N> (4 octtes).
1003 1603
1004Example: read a block of data prefixed by its length in BER-encoded 1604Example: read a block of data prefixed by its length in BER-encoded
1005format (very efficient). 1605format (very efficient).
1006 1606
1007 $handle->push_read (packstring => "w", sub { 1607 $handle->push_read (packstring => "w", sub {
1013register_read_type packstring => sub { 1613register_read_type packstring => sub {
1014 my ($self, $cb, $format) = @_; 1614 my ($self, $cb, $format) = @_;
1015 1615
1016 sub { 1616 sub {
1017 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method 1617 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1018 defined (my $len = eval { unpack $format, $_[0]->{rbuf} }) 1618 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1019 or return; 1619 or return;
1020 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 {
1021 # remove prefix 1629 # remove prefix
1022 substr $_[0]->{rbuf}, 0, (length pack $format, $len), ""; 1630 substr $_[0]{rbuf}, 0, $format, "";
1023 1631
1024 # read rest 1632 # read remaining chunk
1025 $_[0]->unshift_read (chunk => $len, $cb); 1633 $_[0]->unshift_read (chunk => $len, $cb);
1634 }
1026 1635
1027 1 1636 1
1028 } 1637 }
1029}; 1638};
1030 1639
1031=item json => $cb->($handle, $hash_or_arrayref) 1640=item json => $cb->($handle, $hash_or_arrayref)
1032 1641
1033Reads a JSON object or array, decodes it and passes it to the callback. 1642Reads a JSON object or array, decodes it and passes it to the
1643callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1034 1644
1035If a C<json> object was passed to the constructor, then that will be used 1645If a C<json> object was passed to the constructor, then that will be used
1036for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1646for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1037 1647
1038This read type uses the incremental parser available with JSON version 1648This read type uses the incremental parser available with JSON version
1045the C<json> write type description, above, for an actual example. 1655the C<json> write type description, above, for an actual example.
1046 1656
1047=cut 1657=cut
1048 1658
1049register_read_type json => sub { 1659register_read_type json => sub {
1050 my ($self, $cb, $accept, $reject, $skip) = @_; 1660 my ($self, $cb) = @_;
1051 1661
1052 require JSON; 1662 my $json = $self->{json} ||= json_coder;
1053 1663
1054 my $data; 1664 my $data;
1055 my $rbuf = \$self->{rbuf}; 1665 my $rbuf = \$self->{rbuf};
1056 1666
1057 my $json = $self->{json} ||= JSON->new->utf8;
1058
1059 sub { 1667 sub {
1060 my $ref = $json->incr_parse ($self->{rbuf}); 1668 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1061 1669
1062 if ($ref) { 1670 if ($ref) {
1063 $self->{rbuf} = $json->incr_text; 1671 $self->{rbuf} = $json->incr_text;
1064 $json->incr_text = ""; 1672 $json->incr_text = "";
1065 $cb->($self, $ref); 1673 $cb->($self, $ref);
1066 1674
1067 1 1675 1
1676 } elsif ($@) {
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 ()
1068 } else { 1686 } else {
1069 $self->{rbuf} = ""; 1687 $self->{rbuf} = "";
1688
1070 () 1689 ()
1071 } 1690 }
1072 } 1691 }
1073}; 1692};
1074 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
1075=back 1739=back
1076 1740
1077=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1741=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1078 1742
1079This function (not method) lets you add your own types to C<push_read>. 1743Instead of one of the predefined types, you can also specify the name
1744of a package. AnyEvent will try to load the package and then expects to
1745find a function named C<anyevent_read_type> inside. If it isn't found, it
1746progressively tries to load the parent package until it either finds the
1747function (good) or runs out of packages (bad).
1080 1748
1081Whenever the given C<type> is used, C<push_read> will invoke the code 1749Whenever this type is used, C<push_read> will invoke the function with the
1082reference with the handle object, the callback and the remaining 1750handle object, the original callback and the remaining arguments.
1083arguments.
1084 1751
1085The code reference is supposed to return a callback (usually a closure) 1752The function is supposed to return a callback (usually a closure) that
1086that works as a plain read callback (see C<< ->push_read ($cb) >>). 1753works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1754mentally treat the function as a "configurable read type to read callback"
1755converter.
1087 1756
1088It should invoke the passed callback when it is done reading (remember to 1757It should invoke the original callback when it is done reading (remember
1089pass C<$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).
1090 1760
1091Note that this is a function, and all types registered this way will be
1092global, so try to use unique names.
1093
1094For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1761For examples, see the source of this module (F<perldoc -m
1095search for C<register_read_type>)). 1762AnyEvent::Handle>, search for C<register_read_type>)).
1096 1763
1097=item $handle->stop_read 1764=item $handle->stop_read
1098 1765
1099=item $handle->start_read 1766=item $handle->start_read
1100 1767
1106Note that AnyEvent::Handle will automatically C<start_read> for you when 1773Note that AnyEvent::Handle will automatically C<start_read> for you when
1107you change the C<on_read> callback or push/unshift a read callback, and it 1774you change the C<on_read> callback or push/unshift a read callback, and it
1108will automatically C<stop_read> for you when neither C<on_read> is set nor 1775will automatically C<stop_read> for you when neither C<on_read> is set nor
1109there are any read requests in the queue. 1776there are any read requests in the queue.
1110 1777
1778In older versions of this module (<= 5.3), these methods had no effect,
1779as TLS does not support half-duplex connections. In current versions they
1780work as expected, as this behaviour is required to avoid certain resource
1781attacks, where the program would be forced to read (and buffer) arbitrary
1782amounts of data before being able to send some data. The drawback is that
1783some readings of the the SSL/TLS specifications basically require this
1784attack to be working, as SSL/TLS implementations might stall sending data
1785during a rehandshake.
1786
1787As a guideline, during the initial handshake, you should not stop reading,
1788and as a client, it might cause problems, depending on your applciation.
1789
1111=cut 1790=cut
1112 1791
1113sub stop_read { 1792sub stop_read {
1114 my ($self) = @_; 1793 my ($self) = @_;
1115 1794
1117} 1796}
1118 1797
1119sub start_read { 1798sub start_read {
1120 my ($self) = @_; 1799 my ($self) = @_;
1121 1800
1122 unless ($self->{_rw} || $self->{_eof}) { 1801 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1123 Scalar::Util::weaken $self; 1802 Scalar::Util::weaken $self;
1124 1803
1125 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1804 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1126 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1805 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1127 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1806 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1128 1807
1129 if ($len > 0) { 1808 if ($len > 0) {
1130 $self->{_activity} = AnyEvent->now; 1809 $self->{_activity} = $self->{_ractivity} = AE::now;
1131 1810
1132 $self->{filter_r} 1811 if ($self->{tls}) {
1133 ? $self->{filter_r}($self, $rbuf) 1812 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1134 : $self->{_in_drain} || $self->_drain_rbuf; 1813
1814 &_dotls ($self);
1815 } else {
1816 $self->_drain_rbuf;
1817 }
1818
1819 if ($len == $self->{read_size}) {
1820 $self->{read_size} *= 2;
1821 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1822 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1823 }
1135 1824
1136 } elsif (defined $len) { 1825 } elsif (defined $len) {
1137 delete $self->{_rw}; 1826 delete $self->{_rw};
1138 $self->{_eof} = 1; 1827 $self->{_eof} = 1;
1139 $self->_drain_rbuf unless $self->{_in_drain}; 1828 $self->_drain_rbuf;
1140 1829
1141 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 1830 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
1142 return $self->_error ($!, 1); 1831 return $self->_error ($!, 1);
1143 } 1832 }
1144 }); 1833 };
1145 } 1834 }
1146} 1835}
1147 1836
1837our $ERROR_SYSCALL;
1838our $ERROR_WANT_READ;
1839
1840sub _tls_error {
1841 my ($self, $err) = @_;
1842
1843 return $self->_error ($!, 1)
1844 if $err == Net::SSLeay::ERROR_SYSCALL ();
1845
1846 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1847
1848 # reduce error string to look less scary
1849 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1850
1851 if ($self->{_on_starttls}) {
1852 (delete $self->{_on_starttls})->($self, undef, $err);
1853 &_freetls;
1854 } else {
1855 &_freetls;
1856 $self->_error (Errno::EPROTO, 1, $err);
1857 }
1858}
1859
1860# poll the write BIO and send the data if applicable
1861# also decode read data if possible
1862# this is basiclaly our TLS state machine
1863# more efficient implementations are possible with openssl,
1864# but not with the buggy and incomplete Net::SSLeay.
1148sub _dotls { 1865sub _dotls {
1149 my ($self) = @_; 1866 my ($self) = @_;
1150 1867
1151 my $buf; 1868 my $tmp;
1152 1869
1153 if (length $self->{_tls_wbuf}) { 1870 if (length $self->{_tls_wbuf}) {
1154 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1871 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1155 substr $self->{_tls_wbuf}, 0, $len, ""; 1872 substr $self->{_tls_wbuf}, 0, $tmp, "";
1156 } 1873 }
1157 }
1158 1874
1875 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1876 return $self->_tls_error ($tmp)
1877 if $tmp != $ERROR_WANT_READ
1878 && ($tmp != $ERROR_SYSCALL || $!);
1879 }
1880
1881 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1882 unless (length $tmp) {
1883 $self->{_on_starttls}
1884 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
1885 &_freetls;
1886
1887 if ($self->{on_stoptls}) {
1888 $self->{on_stoptls}($self);
1889 return;
1890 } else {
1891 # let's treat SSL-eof as we treat normal EOF
1892 delete $self->{_rw};
1893 $self->{_eof} = 1;
1894 }
1895 }
1896
1897 $self->{_tls_rbuf} .= $tmp;
1898 $self->_drain_rbuf;
1899 $self->{tls} or return; # tls session might have gone away in callback
1900 }
1901
1902 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1903 return $self->_tls_error ($tmp)
1904 if $tmp != $ERROR_WANT_READ
1905 && ($tmp != $ERROR_SYSCALL || $!);
1906
1159 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 1907 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1160 $self->{wbuf} .= $buf; 1908 $self->{wbuf} .= $tmp;
1161 $self->_drain_wbuf; 1909 $self->_drain_wbuf;
1910 $self->{tls} or return; # tls session might have gone away in callback
1162 } 1911 }
1163 1912
1164 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1913 $self->{_on_starttls}
1165 if (length $buf) { 1914 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1166 $self->{rbuf} .= $buf; 1915 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1167 $self->_drain_rbuf unless $self->{_in_drain};
1168 } else {
1169 # let's treat SSL-eof as we treat normal EOF
1170 $self->{_eof} = 1;
1171 $self->_shutdown;
1172 return;
1173 }
1174 }
1175
1176 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1177
1178 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1179 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1180 return $self->_error ($!, 1);
1181 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1182 return $self->_error (&Errno::EIO, 1);
1183 }
1184
1185 # all others are fine for our purposes
1186 }
1187} 1916}
1188 1917
1189=item $handle->starttls ($tls[, $tls_ctx]) 1918=item $handle->starttls ($tls[, $tls_ctx])
1190 1919
1191Instead of starting TLS negotiation immediately when the AnyEvent::Handle 1920Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1192object is created, you can also do that at a later time by calling 1921object is created, you can also do that at a later time by calling
1193C<starttls>. 1922C<starttls>.
1194 1923
1924Starting TLS is currently an asynchronous operation - when you push some
1925write data and then call C<< ->starttls >> then TLS negotiation will start
1926immediately, after which the queued write data is then sent.
1927
1195The first argument is the same as the C<tls> constructor argument (either 1928The first argument is the same as the C<tls> constructor argument (either
1196C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1929C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1197 1930
1198The second argument is the optional C<Net::SSLeay::CTX> object that is 1931The second argument is the optional C<AnyEvent::TLS> object that is used
1199used when AnyEvent::Handle has to create its own TLS connection object. 1932when AnyEvent::Handle has to create its own TLS connection object, or
1933a hash reference with C<< key => value >> pairs that will be used to
1934construct a new context.
1200 1935
1201The TLS connection object will end up in C<< $handle->{tls} >> after this 1936The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1202call and can be used or changed to your liking. Note that the handshake 1937context in C<< $handle->{tls_ctx} >> after this call and can be used or
1203might have already started when this function returns. 1938changed to your liking. Note that the handshake might have already started
1939when this function returns.
1204 1940
1941Due to bugs in OpenSSL, it might or might not be possible to do multiple
1942handshakes on the same stream. It is best to not attempt to use the
1943stream after stopping TLS.
1944
1945This method may invoke callbacks (and therefore the handle might be
1946destroyed after it returns).
1947
1205=cut 1948=cut
1949
1950our %TLS_CACHE; #TODO not yet documented, should we?
1206 1951
1207sub starttls { 1952sub starttls {
1208 my ($self, $ssl, $ctx) = @_; 1953 my ($self, $tls, $ctx) = @_;
1209 1954
1210 $self->stoptls; 1955 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
1956 if $self->{tls};
1211 1957
1212 if ($ssl eq "accept") { 1958 $self->{tls} = $tls;
1213 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1959 $self->{tls_ctx} = $ctx if @_ > 2;
1214 Net::SSLeay::set_accept_state ($ssl); 1960
1215 } elsif ($ssl eq "connect") { 1961 return unless $self->{fh};
1216 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1962
1217 Net::SSLeay::set_connect_state ($ssl); 1963 require Net::SSLeay;
1964
1965 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1966 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1967
1968 $tls = delete $self->{tls};
1969 $ctx = $self->{tls_ctx};
1970
1971 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
1972
1973 if ("HASH" eq ref $ctx) {
1974 require AnyEvent::TLS;
1975
1976 if ($ctx->{cache}) {
1977 my $key = $ctx+0;
1978 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1979 } else {
1980 $ctx = new AnyEvent::TLS %$ctx;
1981 }
1982 }
1218 } 1983
1219 1984 $self->{tls_ctx} = $ctx || TLS_CTX ();
1220 $self->{tls} = $ssl; 1985 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1221 1986
1222 # basically, this is deep magic (because SSL_read should have the same issues) 1987 # basically, this is deep magic (because SSL_read should have the same issues)
1223 # but the openssl maintainers basically said: "trust us, it just works". 1988 # but the openssl maintainers basically said: "trust us, it just works".
1224 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1989 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1225 # and mismaintained ssleay-module doesn't even offer them). 1990 # and mismaintained ssleay-module doesn't even offer them).
1226 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1991 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1992 #
1993 # in short: this is a mess.
1994 #
1995 # note that we do not try to keep the length constant between writes as we are required to do.
1996 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1997 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1998 # have identity issues in that area.
1227 Net::SSLeay::CTX_set_mode ($self->{tls}, 1999# Net::SSLeay::CTX_set_mode ($ssl,
1228 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 2000# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1229 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 2001# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
2002 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1230 2003
1231 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2004 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1232 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2005 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1233 2006
2007 Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf});
2008
1234 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2009 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1235 2010
1236 $self->{filter_w} = sub { 2011 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1237 $_[0]{_tls_wbuf} .= ${$_[1]}; 2012 if $self->{on_starttls};
1238 &_dotls; 2013
1239 }; 2014 &_dotls; # need to trigger the initial handshake
1240 $self->{filter_r} = sub { 2015 $self->start_read; # make sure we actually do read
1241 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1242 &_dotls;
1243 };
1244} 2016}
1245 2017
1246=item $handle->stoptls 2018=item $handle->stoptls
1247 2019
1248Destroys the SSL connection, if any. Partial read or write data will be 2020Shuts down the SSL connection - this makes a proper EOF handshake by
1249lost. 2021sending a close notify to the other side, but since OpenSSL doesn't
2022support non-blocking shut downs, it is not guaranteed that you can re-use
2023the stream afterwards.
2024
2025This method may invoke callbacks (and therefore the handle might be
2026destroyed after it returns).
1250 2027
1251=cut 2028=cut
1252 2029
1253sub stoptls { 2030sub stoptls {
1254 my ($self) = @_; 2031 my ($self) = @_;
1255 2032
1256 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 2033 if ($self->{tls} && $self->{fh}) {
2034 Net::SSLeay::shutdown ($self->{tls});
1257 2035
1258 delete $self->{_rbio}; 2036 &_dotls;
1259 delete $self->{_wbio}; 2037
1260 delete $self->{_tls_wbuf}; 2038# # we don't give a shit. no, we do, but we can't. no...#d#
1261 delete $self->{filter_r}; 2039# # we, we... have to use openssl :/#d#
1262 delete $self->{filter_w}; 2040# &_freetls;#d#
2041 }
2042}
2043
2044sub _freetls {
2045 my ($self) = @_;
2046
2047 return unless $self->{tls};
2048
2049 $self->{tls_ctx}->_put_session (delete $self->{tls})
2050 if $self->{tls} > 0;
2051
2052 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1263} 2053}
1264 2054
1265sub DESTROY { 2055sub DESTROY {
1266 my $self = shift; 2056 my ($self) = @_;
1267 2057
1268 $self->stoptls; 2058 &_freetls;
1269 2059
1270 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 2060 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1271 2061
1272 if ($linger && length $self->{wbuf}) { 2062 if ($linger && length $self->{wbuf} && $self->{fh}) {
1273 my $fh = delete $self->{fh}; 2063 my $fh = delete $self->{fh};
1274 my $wbuf = delete $self->{wbuf}; 2064 my $wbuf = delete $self->{wbuf};
1275 2065
1276 my @linger; 2066 my @linger;
1277 2067
1278 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub { 2068 push @linger, AE::io $fh, 1, sub {
1279 my $len = syswrite $fh, $wbuf, length $wbuf; 2069 my $len = syswrite $fh, $wbuf, length $wbuf;
1280 2070
1281 if ($len > 0) { 2071 if ($len > 0) {
1282 substr $wbuf, 0, $len, ""; 2072 substr $wbuf, 0, $len, "";
1283 } else { 2073 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1284 @linger = (); # end 2074 @linger = (); # end
1285 } 2075 }
2076 };
2077 push @linger, AE::timer $linger, 0, sub {
2078 @linger = ();
2079 };
2080 }
2081}
2082
2083=item $handle->destroy
2084
2085Shuts down the handle object as much as possible - this call ensures that
2086no further callbacks will be invoked and as many resources as possible
2087will be freed. Any method you will call on the handle object after
2088destroying it in this way will be silently ignored (and it will return the
2089empty list).
2090
2091Normally, you can just "forget" any references to an AnyEvent::Handle
2092object and it will simply shut down. This works in fatal error and EOF
2093callbacks, as well as code outside. It does I<NOT> work in a read or write
2094callback, so when you want to destroy the AnyEvent::Handle object from
2095within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
2096that case.
2097
2098Destroying the handle object in this way has the advantage that callbacks
2099will be removed as well, so if those are the only reference holders (as
2100is common), then one doesn't need to do anything special to break any
2101reference cycles.
2102
2103The handle might still linger in the background and write out remaining
2104data, as specified by the C<linger> option, however.
2105
2106=cut
2107
2108sub destroy {
2109 my ($self) = @_;
2110
2111 $self->DESTROY;
2112 %$self = ();
2113 bless $self, "AnyEvent::Handle::destroyed";
2114}
2115
2116sub AnyEvent::Handle::destroyed::AUTOLOAD {
2117 #nop
2118}
2119
2120=item $handle->destroyed
2121
2122Returns false as long as the handle hasn't been destroyed by a call to C<<
2123->destroy >>, true otherwise.
2124
2125Can be useful to decide whether the handle is still valid after some
2126callback possibly destroyed the handle. For example, C<< ->push_write >>,
2127C<< ->starttls >> and other methods can call user callbacks, which in turn
2128can destroy the handle, so work can be avoided by checking sometimes:
2129
2130 $hdl->starttls ("accept");
2131 return if $hdl->destroyed;
2132 $hdl->push_write (...
2133
2134Note that the call to C<push_write> will silently be ignored if the handle
2135has been destroyed, so often you can just ignore the possibility of the
2136handle being destroyed.
2137
2138=cut
2139
2140sub destroyed { 0 }
2141sub AnyEvent::Handle::destroyed::destroyed { 1 }
2142
2143=item AnyEvent::Handle::TLS_CTX
2144
2145This function creates and returns the AnyEvent::TLS object used by default
2146for TLS mode.
2147
2148The context is created by calling L<AnyEvent::TLS> without any arguments.
2149
2150=cut
2151
2152our $TLS_CTX;
2153
2154sub TLS_CTX() {
2155 $TLS_CTX ||= do {
2156 require AnyEvent::TLS;
2157
2158 new AnyEvent::TLS
2159 }
2160}
2161
2162=back
2163
2164
2165=head1 NONFREQUENTLY ASKED QUESTIONS
2166
2167=over 4
2168
2169=item I C<undef> the AnyEvent::Handle reference inside my callback and
2170still get further invocations!
2171
2172That's because AnyEvent::Handle keeps a reference to itself when handling
2173read or write callbacks.
2174
2175It is only safe to "forget" the reference inside EOF or error callbacks,
2176from within all other callbacks, you need to explicitly call the C<<
2177->destroy >> method.
2178
2179=item Why is my C<on_eof> callback never called?
2180
2181Probably because your C<on_error> callback is being called instead: When
2182you have outstanding requests in your read queue, then an EOF is
2183considered an error as you clearly expected some data.
2184
2185To avoid this, make sure you have an empty read queue whenever your handle
2186is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
2187an C<on_read> handler that simply pushes the first read requests in the
2188queue.
2189
2190See also the next question, which explains this in a bit more detail.
2191
2192=item How can I serve requests in a loop?
2193
2194Most protocols consist of some setup phase (authentication for example)
2195followed by a request handling phase, where the server waits for requests
2196and handles them, in a loop.
2197
2198There are two important variants: The first (traditional, better) variant
2199handles requests until the server gets some QUIT command, causing it to
2200close the connection first (highly desirable for a busy TCP server). A
2201client dropping the connection is an error, which means this variant can
2202detect an unexpected detection close.
2203
2204To handle this case, always make sure you have a on-empty read queue, by
2205pushing the "read request start" handler on it:
2206
2207 # we assume a request starts with a single line
2208 my @start_request; @start_request = (line => sub {
2209 my ($hdl, $line) = @_;
2210
2211 ... handle request
2212
2213 # push next request read, possibly from a nested callback
2214 $hdl->push_read (@start_request);
2215 });
2216
2217 # auth done, now go into request handling loop
2218 # now push the first @start_request
2219 $hdl->push_read (@start_request);
2220
2221By always having an outstanding C<push_read>, the handle always expects
2222some data and raises the C<EPIPE> error when the connction is dropped
2223unexpectedly.
2224
2225The second variant is a protocol where the client can drop the connection
2226at any time. For TCP, this means that the server machine may run out of
2227sockets easier, and in general, it means you cnanot distinguish a protocl
2228failure/client crash from a normal connection close. Nevertheless, these
2229kinds of protocols are common (and sometimes even the best solution to the
2230problem).
2231
2232Having an outstanding read request at all times is possible if you ignore
2233C<EPIPE> errors, but this doesn't help with when the client drops the
2234connection during a request, which would still be an error.
2235
2236A better solution is to push the initial request read in an C<on_read>
2237callback. This avoids an error, as when the server doesn't expect data
2238(i.e. is idly waiting for the next request, an EOF will not raise an
2239error, but simply result in an C<on_eof> callback. It is also a bit slower
2240and simpler:
2241
2242 # auth done, now go into request handling loop
2243 $hdl->on_read (sub {
2244 my ($hdl) = @_;
2245
2246 # called each time we receive data but the read queue is empty
2247 # simply start read the request
2248
2249 $hdl->push_read (line => sub {
2250 my ($hdl, $line) = @_;
2251
2252 ... handle request
2253
2254 # do nothing special when the request has been handled, just
2255 # let the request queue go empty.
1286 }); 2256 });
1287 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1288 @linger = ();
1289 }); 2257 });
2258
2259=item I get different callback invocations in TLS mode/Why can't I pause
2260reading?
2261
2262Unlike, say, TCP, TLS connections do not consist of two independent
2263communication channels, one for each direction. Or put differently, the
2264read and write directions are not independent of each other: you cannot
2265write data unless you are also prepared to read, and vice versa.
2266
2267This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2268callback invocations when you are not expecting any read data - the reason
2269is that AnyEvent::Handle always reads in TLS mode.
2270
2271During the connection, you have to make sure that you always have a
2272non-empty read-queue, or an C<on_read> watcher. At the end of the
2273connection (or when you no longer want to use it) you can call the
2274C<destroy> method.
2275
2276=item How do I read data until the other side closes the connection?
2277
2278If you just want to read your data into a perl scalar, the easiest way
2279to achieve this is by setting an C<on_read> callback that does nothing,
2280clearing the C<on_eof> callback and in the C<on_error> callback, the data
2281will be in C<$_[0]{rbuf}>:
2282
2283 $handle->on_read (sub { });
2284 $handle->on_eof (undef);
2285 $handle->on_error (sub {
2286 my $data = delete $_[0]{rbuf};
2287 });
2288
2289The reason to use C<on_error> is that TCP connections, due to latencies
2290and packets loss, might get closed quite violently with an error, when in
2291fact all data has been received.
2292
2293It is usually better to use acknowledgements when transferring data,
2294to make sure the other side hasn't just died and you got the data
2295intact. This is also one reason why so many internet protocols have an
2296explicit QUIT command.
2297
2298=item I don't want to destroy the handle too early - how do I wait until
2299all data has been written?
2300
2301After writing your last bits of data, set the C<on_drain> callback
2302and destroy the handle in there - with the default setting of
2303C<low_water_mark> this will be called precisely when all data has been
2304written to the socket:
2305
2306 $handle->push_write (...);
2307 $handle->on_drain (sub {
2308 warn "all data submitted to the kernel\n";
2309 undef $handle;
2310 });
2311
2312If you just want to queue some data and then signal EOF to the other side,
2313consider using C<< ->push_shutdown >> instead.
2314
2315=item I want to contact a TLS/SSL server, I don't care about security.
2316
2317If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2318connect to it and then create the AnyEvent::Handle with the C<tls>
2319parameter:
2320
2321 tcp_connect $host, $port, sub {
2322 my ($fh) = @_;
2323
2324 my $handle = new AnyEvent::Handle
2325 fh => $fh,
2326 tls => "connect",
2327 on_error => sub { ... };
2328
2329 $handle->push_write (...);
1290 } 2330 };
1291}
1292 2331
1293=item AnyEvent::Handle::TLS_CTX 2332=item I want to contact a TLS/SSL server, I do care about security.
1294 2333
1295This function creates and returns the Net::SSLeay::CTX object used by 2334Then you should additionally enable certificate verification, including
1296default for TLS mode. 2335peername verification, if the protocol you use supports it (see
2336L<AnyEvent::TLS>, C<verify_peername>).
1297 2337
1298The context is created like this: 2338E.g. for HTTPS:
1299 2339
1300 Net::SSLeay::load_error_strings; 2340 tcp_connect $host, $port, sub {
1301 Net::SSLeay::SSLeay_add_ssl_algorithms; 2341 my ($fh) = @_;
1302 Net::SSLeay::randomize;
1303 2342
1304 my $CTX = Net::SSLeay::CTX_new; 2343 my $handle = new AnyEvent::Handle
2344 fh => $fh,
2345 peername => $host,
2346 tls => "connect",
2347 tls_ctx => { verify => 1, verify_peername => "https" },
2348 ...
1305 2349
1306 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL 2350Note that you must specify the hostname you connected to (or whatever
2351"peername" the protocol needs) as the C<peername> argument, otherwise no
2352peername verification will be done.
1307 2353
1308=cut 2354The above will use the system-dependent default set of trusted CA
2355certificates. If you want to check against a specific CA, add the
2356C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
1309 2357
1310our $TLS_CTX; 2358 tls_ctx => {
2359 verify => 1,
2360 verify_peername => "https",
2361 ca_file => "my-ca-cert.pem",
2362 },
1311 2363
1312sub TLS_CTX() { 2364=item I want to create a TLS/SSL server, how do I do that?
1313 $TLS_CTX || do {
1314 require Net::SSLeay;
1315 2365
1316 Net::SSLeay::load_error_strings (); 2366Well, you first need to get a server certificate and key. You have
1317 Net::SSLeay::SSLeay_add_ssl_algorithms (); 2367three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
1318 Net::SSLeay::randomize (); 2368self-signed certificate (cheap. check the search engine of your choice,
2369there are many tutorials on the net) or c) make your own CA (tinyca2 is a
2370nice program for that purpose).
1319 2371
1320 $TLS_CTX = Net::SSLeay::CTX_new (); 2372Then create a file with your private key (in PEM format, see
2373L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
2374file should then look like this:
1321 2375
1322 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ()); 2376 -----BEGIN RSA PRIVATE KEY-----
2377 ...header data
2378 ... lots of base64'y-stuff
2379 -----END RSA PRIVATE KEY-----
1323 2380
1324 $TLS_CTX 2381 -----BEGIN CERTIFICATE-----
1325 } 2382 ... lots of base64'y-stuff
1326} 2383 -----END CERTIFICATE-----
2384
2385The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2386specify this file as C<cert_file>:
2387
2388 tcp_server undef, $port, sub {
2389 my ($fh) = @_;
2390
2391 my $handle = new AnyEvent::Handle
2392 fh => $fh,
2393 tls => "accept",
2394 tls_ctx => { cert_file => "my-server-keycert.pem" },
2395 ...
2396
2397When you have intermediate CA certificates that your clients might not
2398know about, just append them to the C<cert_file>.
1327 2399
1328=back 2400=back
2401
1329 2402
1330=head1 SUBCLASSING AnyEvent::Handle 2403=head1 SUBCLASSING AnyEvent::Handle
1331 2404
1332In many cases, you might want to subclass AnyEvent::Handle. 2405In many cases, you might want to subclass AnyEvent::Handle.
1333 2406
1337=over 4 2410=over 4
1338 2411
1339=item * all constructor arguments become object members. 2412=item * all constructor arguments become object members.
1340 2413
1341At least initially, when you pass a C<tls>-argument to the constructor it 2414At least initially, when you pass a C<tls>-argument to the constructor it
1342will end up in C<< $handle->{tls} >>. Those members might be changes or 2415will end up in C<< $handle->{tls} >>. Those members might be changed or
1343mutated later on (for example C<tls> will hold the TLS connection object). 2416mutated later on (for example C<tls> will hold the TLS connection object).
1344 2417
1345=item * other object member names are prefixed with an C<_>. 2418=item * other object member names are prefixed with an C<_>.
1346 2419
1347All object members not explicitly documented (internal use) are prefixed 2420All object members not explicitly documented (internal use) are prefixed
1350 2423
1351=item * all members not documented here and not prefixed with an underscore 2424=item * all members not documented here and not prefixed with an underscore
1352are free to use in subclasses. 2425are free to use in subclasses.
1353 2426
1354Of course, new versions of AnyEvent::Handle may introduce more "public" 2427Of course, new versions of AnyEvent::Handle may introduce more "public"
1355member variables, but thats just life, at least it is documented. 2428member variables, but that's just life. At least it is documented.
1356 2429
1357=back 2430=back
1358 2431
1359=head1 AUTHOR 2432=head1 AUTHOR
1360 2433

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