… | |
… | |
14 | |
14 | |
15 | AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent |
15 | AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent |
16 | |
16 | |
17 | =cut |
17 | =cut |
18 | |
18 | |
19 | our $VERSION = 4.3; |
19 | our $VERSION = 4.4; |
20 | |
20 | |
21 | =head1 SYNOPSIS |
21 | =head1 SYNOPSIS |
22 | |
22 | |
23 | use AnyEvent; |
23 | use AnyEvent; |
24 | use AnyEvent::Handle; |
24 | use AnyEvent::Handle; |
… | |
… | |
27 | |
27 | |
28 | my $handle = |
28 | my $handle = |
29 | AnyEvent::Handle->new ( |
29 | AnyEvent::Handle->new ( |
30 | fh => \*STDIN, |
30 | fh => \*STDIN, |
31 | on_eof => sub { |
31 | on_eof => sub { |
32 | $cv->broadcast; |
32 | $cv->send; |
33 | }, |
33 | }, |
34 | ); |
34 | ); |
35 | |
35 | |
36 | # send some request line |
36 | # send some request line |
37 | $handle->push_write ("getinfo\015\012"); |
37 | $handle->push_write ("getinfo\015\012"); |
… | |
… | |
59 | treatment of characters applies to this module as well. |
59 | treatment of characters applies to this module as well. |
60 | |
60 | |
61 | All callbacks will be invoked with the handle object as their first |
61 | All callbacks will be invoked with the handle object as their first |
62 | argument. |
62 | argument. |
63 | |
63 | |
64 | =head2 SIGPIPE is not handled by this module |
|
|
65 | |
|
|
66 | SIGPIPE is not handled by this module, so one of the practical |
|
|
67 | requirements of using it is to ignore SIGPIPE (C<$SIG{PIPE} = |
|
|
68 | 'IGNORE'>). At least, this is highly recommend in a networked program: If |
|
|
69 | you use AnyEvent::Handle in a filter program (like sort), exiting on |
|
|
70 | SIGPIPE is probably the right thing to do. |
|
|
71 | |
|
|
72 | =head1 METHODS |
64 | =head1 METHODS |
73 | |
65 | |
74 | =over 4 |
66 | =over 4 |
75 | |
67 | |
76 | =item B<new (%args)> |
68 | =item B<new (%args)> |
… | |
… | |
92 | Set the callback to be called when an end-of-file condition is detected, |
84 | Set the callback to be called when an end-of-file condition is detected, |
93 | i.e. in the case of a socket, when the other side has closed the |
85 | i.e. in the case of a socket, when the other side has closed the |
94 | connection cleanly. |
86 | connection cleanly. |
95 | |
87 | |
96 | For sockets, this just means that the other side has stopped sending data, |
88 | For sockets, this just means that the other side has stopped sending data, |
97 | you can still try to write data, and, in fact, one can return from the eof |
89 | you can still try to write data, and, in fact, one can return from the EOF |
98 | callback and continue writing data, as only the read part has been shut |
90 | callback and continue writing data, as only the read part has been shut |
99 | down. |
91 | down. |
100 | |
92 | |
101 | While not mandatory, it is I<highly> recommended to set an eof callback, |
93 | While not mandatory, it is I<highly> recommended to set an EOF callback, |
102 | otherwise you might end up with a closed socket while you are still |
94 | otherwise you might end up with a closed socket while you are still |
103 | waiting for data. |
95 | waiting for data. |
104 | |
96 | |
105 | If an EOF condition has been detected but no C<on_eof> callback has been |
97 | If an EOF condition has been detected but no C<on_eof> callback has been |
106 | set, then a fatal error will be raised with C<$!> set to <0>. |
98 | set, then a fatal error will be raised with C<$!> set to <0>. |
… | |
… | |
135 | and no read request is in the queue (unlike read queue callbacks, this |
127 | and no read request is in the queue (unlike read queue callbacks, this |
136 | callback will only be called when at least one octet of data is in the |
128 | callback will only be called when at least one octet of data is in the |
137 | read buffer). |
129 | read buffer). |
138 | |
130 | |
139 | To access (and remove data from) the read buffer, use the C<< ->rbuf >> |
131 | To access (and remove data from) the read buffer, use the C<< ->rbuf >> |
140 | method or access the C<$handle->{rbuf}> member directly. |
132 | method or access the C<$handle->{rbuf}> member directly. Note that you |
|
|
133 | must not enlarge or modify the read buffer, you can only remove data at |
|
|
134 | the beginning from it. |
141 | |
135 | |
142 | When an EOF condition is detected then AnyEvent::Handle will first try to |
136 | When an EOF condition is detected then AnyEvent::Handle will first try to |
143 | feed all the remaining data to the queued callbacks and C<on_read> before |
137 | feed all the remaining data to the queued callbacks and C<on_read> before |
144 | calling the C<on_eof> callback. If no progress can be made, then a fatal |
138 | calling the C<on_eof> callback. If no progress can be made, then a fatal |
145 | error will be raised (with C<$!> set to C<EPIPE>). |
139 | error will be raised (with C<$!> set to C<EPIPE>). |
… | |
… | |
263 | You can also provide your own TLS connection object, but you have |
257 | You can also provide your own TLS connection object, but you have |
264 | to make sure that you call either C<Net::SSLeay::set_connect_state> |
258 | to make sure that you call either C<Net::SSLeay::set_connect_state> |
265 | or C<Net::SSLeay::set_accept_state> on it before you pass it to |
259 | or C<Net::SSLeay::set_accept_state> on it before you pass it to |
266 | AnyEvent::Handle. |
260 | AnyEvent::Handle. |
267 | |
261 | |
|
|
262 | B<IMPORTANT:> since Net::SSLeay "objects" are really only integers, |
|
|
263 | passing in the wrong integer will lead to certain crash. This most often |
|
|
264 | happens when one uses a stylish C<< tls => 1 >> and is surprised about the |
|
|
265 | segmentation fault. |
|
|
266 | |
268 | See the C<< ->starttls >> method for when need to start TLS negotiation later. |
267 | See the C<< ->starttls >> method for when need to start TLS negotiation later. |
269 | |
268 | |
270 | =item tls_ctx => $ssl_ctx |
269 | =item tls_ctx => $ssl_ctx |
271 | |
270 | |
272 | Use the given C<Net::SSLeay::CTX> object to create the new TLS connection |
271 | Use the given C<Net::SSLeay::CTX> object to create the new TLS connection |
… | |
… | |
334 | |
333 | |
335 | $! = $errno; |
334 | $! = $errno; |
336 | |
335 | |
337 | if ($self->{on_error}) { |
336 | if ($self->{on_error}) { |
338 | $self->{on_error}($self, $fatal); |
337 | $self->{on_error}($self, $fatal); |
339 | } else { |
338 | } elsif ($self->{fh}) { |
340 | Carp::croak "AnyEvent::Handle uncaught error: $!"; |
339 | Carp::croak "AnyEvent::Handle uncaught error: $!"; |
341 | } |
340 | } |
342 | } |
341 | } |
343 | |
342 | |
344 | =item $fh = $handle->fh |
343 | =item $fh = $handle->fh |
… | |
… | |
382 | } |
381 | } |
383 | |
382 | |
384 | =item $handle->autocork ($boolean) |
383 | =item $handle->autocork ($boolean) |
385 | |
384 | |
386 | Enables or disables the current autocork behaviour (see C<autocork> |
385 | Enables or disables the current autocork behaviour (see C<autocork> |
387 | constructor argument). |
386 | constructor argument). Changes will only take effect on the next write. |
388 | |
387 | |
389 | =cut |
388 | =cut |
|
|
389 | |
|
|
390 | sub autocork { |
|
|
391 | $_[0]{autocork} = $_[1]; |
|
|
392 | } |
390 | |
393 | |
391 | =item $handle->no_delay ($boolean) |
394 | =item $handle->no_delay ($boolean) |
392 | |
395 | |
393 | Enables or disables the C<no_delay> setting (see constructor argument of |
396 | Enables or disables the C<no_delay> setting (see constructor argument of |
394 | the same name for details). |
397 | the same name for details). |
… | |
… | |
550 | ->($self, @_); |
553 | ->($self, @_); |
551 | } |
554 | } |
552 | |
555 | |
553 | if ($self->{tls}) { |
556 | if ($self->{tls}) { |
554 | $self->{_tls_wbuf} .= $_[0]; |
557 | $self->{_tls_wbuf} .= $_[0]; |
|
|
558 | |
555 | &_dotls ($self); |
559 | &_dotls ($self); |
556 | } else { |
560 | } else { |
557 | $self->{wbuf} .= $_[0]; |
561 | $self->{wbuf} .= $_[0]; |
558 | $self->_drain_wbuf; |
562 | $self->_drain_wbuf; |
559 | } |
563 | } |
… | |
… | |
577 | =cut |
581 | =cut |
578 | |
582 | |
579 | register_write_type netstring => sub { |
583 | register_write_type netstring => sub { |
580 | my ($self, $string) = @_; |
584 | my ($self, $string) = @_; |
581 | |
585 | |
582 | sprintf "%d:%s,", (length $string), $string |
586 | (length $string) . ":$string," |
583 | }; |
587 | }; |
584 | |
588 | |
585 | =item packstring => $format, $data |
589 | =item packstring => $format, $data |
586 | |
590 | |
587 | An octet string prefixed with an encoded length. The encoding C<$format> |
591 | An octet string prefixed with an encoded length. The encoding C<$format> |
… | |
… | |
765 | ) { |
769 | ) { |
766 | $self->_error (&Errno::ENOSPC, 1), return; |
770 | $self->_error (&Errno::ENOSPC, 1), return; |
767 | } |
771 | } |
768 | |
772 | |
769 | while () { |
773 | while () { |
|
|
774 | # we need to use a separate tls read buffer, as we must not receive data while |
|
|
775 | # we are draining the buffer, and this can only happen with TLS. |
|
|
776 | $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf}; |
|
|
777 | |
770 | my $len = length $self->{rbuf}; |
778 | my $len = length $self->{rbuf}; |
771 | |
779 | |
772 | if (my $cb = shift @{ $self->{_queue} }) { |
780 | if (my $cb = shift @{ $self->{_queue} }) { |
773 | unless ($cb->($self)) { |
781 | unless ($cb->($self)) { |
774 | if ($self->{_eof}) { |
782 | if ($self->{_eof}) { |
… | |
… | |
835 | |
843 | |
836 | =item $handle->rbuf |
844 | =item $handle->rbuf |
837 | |
845 | |
838 | Returns the read buffer (as a modifiable lvalue). |
846 | Returns the read buffer (as a modifiable lvalue). |
839 | |
847 | |
840 | You can access the read buffer directly as the C<< ->{rbuf} >> member, if |
848 | You can access the read buffer directly as the C<< ->{rbuf} >> |
841 | you want. |
849 | member, if you want. However, the only operation allowed on the |
|
|
850 | read buffer (apart from looking at it) is removing data from its |
|
|
851 | beginning. Otherwise modifying or appending to it is not allowed and will |
|
|
852 | lead to hard-to-track-down bugs. |
842 | |
853 | |
843 | NOTE: The read buffer should only be used or modified if the C<on_read>, |
854 | NOTE: The read buffer should only be used or modified if the C<on_read>, |
844 | C<push_read> or C<unshift_read> methods are used. The other read methods |
855 | C<push_read> or C<unshift_read> methods are used. The other read methods |
845 | automatically manage the read buffer. |
856 | automatically manage the read buffer. |
846 | |
857 | |
… | |
… | |
1101 | An octet string prefixed with an encoded length. The encoding C<$format> |
1112 | An octet string prefixed with an encoded length. The encoding C<$format> |
1102 | uses the same format as a Perl C<pack> format, but must specify a single |
1113 | uses the same format as a Perl C<pack> format, but must specify a single |
1103 | integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an |
1114 | integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an |
1104 | optional C<!>, C<< < >> or C<< > >> modifier). |
1115 | optional C<!>, C<< < >> or C<< > >> modifier). |
1105 | |
1116 | |
1106 | DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. |
1117 | For example, DNS over TCP uses a prefix of C<n> (2 octet network order), |
|
|
1118 | EPP uses a prefix of C<N> (4 octtes). |
1107 | |
1119 | |
1108 | Example: read a block of data prefixed by its length in BER-encoded |
1120 | Example: read a block of data prefixed by its length in BER-encoded |
1109 | format (very efficient). |
1121 | format (very efficient). |
1110 | |
1122 | |
1111 | $handle->push_read (packstring => "w", sub { |
1123 | $handle->push_read (packstring => "w", sub { |
… | |
… | |
1141 | } |
1153 | } |
1142 | }; |
1154 | }; |
1143 | |
1155 | |
1144 | =item json => $cb->($handle, $hash_or_arrayref) |
1156 | =item json => $cb->($handle, $hash_or_arrayref) |
1145 | |
1157 | |
1146 | Reads a JSON object or array, decodes it and passes it to the callback. |
1158 | Reads a JSON object or array, decodes it and passes it to the |
|
|
1159 | callback. When a parse error occurs, an C<EBADMSG> error will be raised. |
1147 | |
1160 | |
1148 | If a C<json> object was passed to the constructor, then that will be used |
1161 | If a C<json> object was passed to the constructor, then that will be used |
1149 | for the final decode, otherwise it will create a JSON coder expecting UTF-8. |
1162 | for the final decode, otherwise it will create a JSON coder expecting UTF-8. |
1150 | |
1163 | |
1151 | This read type uses the incremental parser available with JSON version |
1164 | This read type uses the incremental parser available with JSON version |
… | |
… | |
1168 | my $rbuf = \$self->{rbuf}; |
1181 | my $rbuf = \$self->{rbuf}; |
1169 | |
1182 | |
1170 | my $json = $self->{json} ||= JSON->new->utf8; |
1183 | my $json = $self->{json} ||= JSON->new->utf8; |
1171 | |
1184 | |
1172 | sub { |
1185 | sub { |
1173 | my $ref = $json->incr_parse ($self->{rbuf}); |
1186 | my $ref = eval { $json->incr_parse ($self->{rbuf}) }; |
1174 | |
1187 | |
1175 | if ($ref) { |
1188 | if ($ref) { |
1176 | $self->{rbuf} = $json->incr_text; |
1189 | $self->{rbuf} = $json->incr_text; |
1177 | $json->incr_text = ""; |
1190 | $json->incr_text = ""; |
1178 | $cb->($self, $ref); |
1191 | $cb->($self, $ref); |
1179 | |
1192 | |
1180 | 1 |
1193 | 1 |
|
|
1194 | } elsif ($@) { |
|
|
1195 | # error case |
|
|
1196 | $json->incr_skip; |
|
|
1197 | |
|
|
1198 | $self->{rbuf} = $json->incr_text; |
|
|
1199 | $json->incr_text = ""; |
|
|
1200 | |
|
|
1201 | $self->_error (&Errno::EBADMSG); |
|
|
1202 | |
|
|
1203 | () |
1181 | } else { |
1204 | } else { |
1182 | $self->{rbuf} = ""; |
1205 | $self->{rbuf} = ""; |
|
|
1206 | |
1183 | () |
1207 | () |
1184 | } |
1208 | } |
1185 | } |
1209 | } |
1186 | }; |
1210 | }; |
1187 | |
1211 | |
… | |
… | |
1290 | if ($len > 0) { |
1314 | if ($len > 0) { |
1291 | $self->{_activity} = AnyEvent->now; |
1315 | $self->{_activity} = AnyEvent->now; |
1292 | |
1316 | |
1293 | if ($self->{tls}) { |
1317 | if ($self->{tls}) { |
1294 | Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); |
1318 | Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); |
|
|
1319 | |
1295 | &_dotls ($self); |
1320 | &_dotls ($self); |
1296 | } else { |
1321 | } else { |
1297 | $self->_drain_rbuf unless $self->{_in_drain}; |
1322 | $self->_drain_rbuf unless $self->{_in_drain}; |
1298 | } |
1323 | } |
1299 | |
1324 | |
… | |
… | |
1307 | } |
1332 | } |
1308 | }); |
1333 | }); |
1309 | } |
1334 | } |
1310 | } |
1335 | } |
1311 | |
1336 | |
|
|
1337 | # poll the write BIO and send the data if applicable |
1312 | sub _dotls { |
1338 | sub _dotls { |
1313 | my ($self) = @_; |
1339 | my ($self) = @_; |
1314 | |
1340 | |
1315 | my $buf; |
1341 | my $tmp; |
1316 | |
1342 | |
1317 | if (length $self->{_tls_wbuf}) { |
1343 | if (length $self->{_tls_wbuf}) { |
1318 | while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { |
1344 | while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { |
1319 | substr $self->{_tls_wbuf}, 0, $len, ""; |
1345 | substr $self->{_tls_wbuf}, 0, $tmp, ""; |
1320 | } |
1346 | } |
1321 | } |
1347 | } |
1322 | |
1348 | |
1323 | while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { |
1349 | while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) { |
1324 | unless (length $buf) { |
1350 | unless (length $tmp) { |
1325 | # let's treat SSL-eof as we treat normal EOF |
1351 | # let's treat SSL-eof as we treat normal EOF |
1326 | delete $self->{_rw}; |
1352 | delete $self->{_rw}; |
1327 | $self->{_eof} = 1; |
1353 | $self->{_eof} = 1; |
1328 | &_freetls; |
1354 | &_freetls; |
1329 | } |
1355 | } |
1330 | |
1356 | |
1331 | $self->{rbuf} .= $buf; |
1357 | $self->{_tls_rbuf} .= $tmp; |
1332 | $self->_drain_rbuf unless $self->{_in_drain}; |
1358 | $self->_drain_rbuf unless $self->{_in_drain}; |
1333 | $self->{tls} or return; # tls session might have gone away in callback |
1359 | $self->{tls} or return; # tls session might have gone away in callback |
1334 | } |
1360 | } |
1335 | |
1361 | |
1336 | my $err = Net::SSLeay::get_error ($self->{tls}, -1); |
1362 | $tmp = Net::SSLeay::get_error ($self->{tls}, -1); |
1337 | |
1363 | |
1338 | if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { |
1364 | if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) { |
1339 | if ($err == Net::SSLeay::ERROR_SYSCALL ()) { |
1365 | if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) { |
1340 | return $self->_error ($!, 1); |
1366 | return $self->_error ($!, 1); |
1341 | } elsif ($err == Net::SSLeay::ERROR_SSL ()) { |
1367 | } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) { |
1342 | return $self->_error (&Errno::EIO, 1); |
1368 | return $self->_error (&Errno::EIO, 1); |
1343 | } |
1369 | } |
1344 | |
1370 | |
1345 | # all others are fine for our purposes |
1371 | # all other errors are fine for our purposes |
1346 | } |
1372 | } |
1347 | |
1373 | |
1348 | if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { |
1374 | while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) { |
1349 | $self->{wbuf} .= $buf; |
1375 | $self->{wbuf} .= $tmp; |
1350 | $self->_drain_wbuf; |
1376 | $self->_drain_wbuf; |
1351 | } |
1377 | } |
1352 | } |
1378 | } |
1353 | |
1379 | |
1354 | =item $handle->starttls ($tls[, $tls_ctx]) |
1380 | =item $handle->starttls ($tls[, $tls_ctx]) |
… | |
… | |
1375 | sub starttls { |
1401 | sub starttls { |
1376 | my ($self, $ssl, $ctx) = @_; |
1402 | my ($self, $ssl, $ctx) = @_; |
1377 | |
1403 | |
1378 | require Net::SSLeay; |
1404 | require Net::SSLeay; |
1379 | |
1405 | |
1380 | Carp::croak "it is an error to call starttls more than once on an Anyevent::Handle object" |
1406 | Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object" |
1381 | if $self->{tls}; |
1407 | if $self->{tls}; |
1382 | |
1408 | |
1383 | if ($ssl eq "accept") { |
1409 | if ($ssl eq "accept") { |
1384 | $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); |
1410 | $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); |
1385 | Net::SSLeay::set_accept_state ($ssl); |
1411 | Net::SSLeay::set_accept_state ($ssl); |
… | |
… | |
1447 | |
1473 | |
1448 | delete @$self{qw(_rbio _wbio _tls_wbuf)}; |
1474 | delete @$self{qw(_rbio _wbio _tls_wbuf)}; |
1449 | } |
1475 | } |
1450 | |
1476 | |
1451 | sub DESTROY { |
1477 | sub DESTROY { |
1452 | my $self = shift; |
1478 | my ($self) = @_; |
1453 | |
1479 | |
1454 | &_freetls; |
1480 | &_freetls; |
1455 | |
1481 | |
1456 | my $linger = exists $self->{linger} ? $self->{linger} : 3600; |
1482 | my $linger = exists $self->{linger} ? $self->{linger} : 3600; |
1457 | |
1483 | |
… | |
… | |
1474 | @linger = (); |
1500 | @linger = (); |
1475 | }); |
1501 | }); |
1476 | } |
1502 | } |
1477 | } |
1503 | } |
1478 | |
1504 | |
|
|
1505 | =item $handle->destroy |
|
|
1506 | |
|
|
1507 | Shuts down the handle object as much as possible - this call ensures that |
|
|
1508 | no further callbacks will be invoked and resources will be freed as much |
|
|
1509 | as possible. You must not call any methods on the object afterwards. |
|
|
1510 | |
|
|
1511 | Normally, you can just "forget" any references to an AnyEvent::Handle |
|
|
1512 | object and it will simply shut down. This works in fatal error and EOF |
|
|
1513 | callbacks, as well as code outside. It does I<NOT> work in a read or write |
|
|
1514 | callback, so when you want to destroy the AnyEvent::Handle object from |
|
|
1515 | within such an callback. You I<MUST> call C<< ->destroy >> explicitly in |
|
|
1516 | that case. |
|
|
1517 | |
|
|
1518 | The handle might still linger in the background and write out remaining |
|
|
1519 | data, as specified by the C<linger> option, however. |
|
|
1520 | |
|
|
1521 | =cut |
|
|
1522 | |
|
|
1523 | sub destroy { |
|
|
1524 | my ($self) = @_; |
|
|
1525 | |
|
|
1526 | $self->DESTROY; |
|
|
1527 | %$self = (); |
|
|
1528 | } |
|
|
1529 | |
1479 | =item AnyEvent::Handle::TLS_CTX |
1530 | =item AnyEvent::Handle::TLS_CTX |
1480 | |
1531 | |
1481 | This function creates and returns the Net::SSLeay::CTX object used by |
1532 | This function creates and returns the Net::SSLeay::CTX object used by |
1482 | default for TLS mode. |
1533 | default for TLS mode. |
1483 | |
1534 | |
… | |
… | |
1511 | } |
1562 | } |
1512 | } |
1563 | } |
1513 | |
1564 | |
1514 | =back |
1565 | =back |
1515 | |
1566 | |
|
|
1567 | |
|
|
1568 | =head1 NONFREQUENTLY ASKED QUESTIONS |
|
|
1569 | |
|
|
1570 | =over 4 |
|
|
1571 | |
|
|
1572 | =item I C<undef> the AnyEvent::Handle reference inside my callback and |
|
|
1573 | still get further invocations! |
|
|
1574 | |
|
|
1575 | That's because AnyEvent::Handle keeps a reference to itself when handling |
|
|
1576 | read or write callbacks. |
|
|
1577 | |
|
|
1578 | It is only safe to "forget" the reference inside EOF or error callbacks, |
|
|
1579 | from within all other callbacks, you need to explicitly call the C<< |
|
|
1580 | ->destroy >> method. |
|
|
1581 | |
|
|
1582 | =item I get different callback invocations in TLS mode/Why can't I pause |
|
|
1583 | reading? |
|
|
1584 | |
|
|
1585 | Unlike, say, TCP, TLS connections do not consist of two independent |
|
|
1586 | communication channels, one for each direction. Or put differently. The |
|
|
1587 | read and write directions are not independent of each other: you cannot |
|
|
1588 | write data unless you are also prepared to read, and vice versa. |
|
|
1589 | |
|
|
1590 | This can mean than, in TLS mode, you might get C<on_error> or C<on_eof> |
|
|
1591 | callback invocations when you are not expecting any read data - the reason |
|
|
1592 | is that AnyEvent::Handle always reads in TLS mode. |
|
|
1593 | |
|
|
1594 | During the connection, you have to make sure that you always have a |
|
|
1595 | non-empty read-queue, or an C<on_read> watcher. At the end of the |
|
|
1596 | connection (or when you no longer want to use it) you can call the |
|
|
1597 | C<destroy> method. |
|
|
1598 | |
|
|
1599 | =item How do I read data until the other side closes the connection? |
|
|
1600 | |
|
|
1601 | If you just want to read your data into a perl scalar, the easiest way |
|
|
1602 | to achieve this is by setting an C<on_read> callback that does nothing, |
|
|
1603 | clearing the C<on_eof> callback and in the C<on_error> callback, the data |
|
|
1604 | will be in C<$_[0]{rbuf}>: |
|
|
1605 | |
|
|
1606 | $handle->on_read (sub { }); |
|
|
1607 | $handle->on_eof (undef); |
|
|
1608 | $handle->on_error (sub { |
|
|
1609 | my $data = delete $_[0]{rbuf}; |
|
|
1610 | undef $handle; |
|
|
1611 | }); |
|
|
1612 | |
|
|
1613 | The reason to use C<on_error> is that TCP connections, due to latencies |
|
|
1614 | and packets loss, might get closed quite violently with an error, when in |
|
|
1615 | fact, all data has been received. |
|
|
1616 | |
|
|
1617 | It is usually better to use acknowledgements when transferring data, |
|
|
1618 | to make sure the other side hasn't just died and you got the data |
|
|
1619 | intact. This is also one reason why so many internet protocols have an |
|
|
1620 | explicit QUIT command. |
|
|
1621 | |
|
|
1622 | =item I don't want to destroy the handle too early - how do I wait until |
|
|
1623 | all data has been written? |
|
|
1624 | |
|
|
1625 | After writing your last bits of data, set the C<on_drain> callback |
|
|
1626 | and destroy the handle in there - with the default setting of |
|
|
1627 | C<low_water_mark> this will be called precisely when all data has been |
|
|
1628 | written to the socket: |
|
|
1629 | |
|
|
1630 | $handle->push_write (...); |
|
|
1631 | $handle->on_drain (sub { |
|
|
1632 | warn "all data submitted to the kernel\n"; |
|
|
1633 | undef $handle; |
|
|
1634 | }); |
|
|
1635 | |
|
|
1636 | =back |
|
|
1637 | |
|
|
1638 | |
1516 | =head1 SUBCLASSING AnyEvent::Handle |
1639 | =head1 SUBCLASSING AnyEvent::Handle |
1517 | |
1640 | |
1518 | In many cases, you might want to subclass AnyEvent::Handle. |
1641 | In many cases, you might want to subclass AnyEvent::Handle. |
1519 | |
1642 | |
1520 | To make this easier, a given version of AnyEvent::Handle uses these |
1643 | To make this easier, a given version of AnyEvent::Handle uses these |