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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 = 4.15; |
19 | our $VERSION = 4.21; |
20 | |
20 | |
21 | =head1 SYNOPSIS |
21 | =head1 SYNOPSIS |
22 | |
22 | |
23 | use AnyEvent; |
23 | use AnyEvent; |
24 | use AnyEvent::Handle; |
24 | use AnyEvent::Handle; |
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124 | This sets the callback that is called when the write buffer becomes empty |
124 | This 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). |
125 | (or when the callback is set and the buffer is empty already). |
126 | |
126 | |
127 | To append to the write buffer, use the C<< ->push_write >> method. |
127 | To append to the write buffer, use the C<< ->push_write >> method. |
128 | |
128 | |
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129 | This callback is useful when you don't want to put all of your write data |
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130 | into the queue at once, for example, when you want to write the contents |
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131 | of some file to the socket you might not want to read the whole file into |
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132 | memory and push it into the queue, but instead only read more data from |
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133 | the file when the write queue becomes empty. |
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134 | |
129 | =item timeout => $fractional_seconds |
135 | =item timeout => $fractional_seconds |
130 | |
136 | |
131 | If non-zero, then this enables an "inactivity" timeout: whenever this many |
137 | If non-zero, then this enables an "inactivity" timeout: whenever this many |
132 | seconds pass without a successful read or write on the underlying file |
138 | seconds pass without a successful read or write on the underlying file |
133 | handle, the C<on_timeout> callback will be invoked (and if that one is |
139 | handle, the C<on_timeout> callback will be invoked (and if that one is |
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156 | be configured to accept only so-and-so much data that it cannot act on |
162 | be 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 |
163 | (for example, when expecting a line, an attacker could send an unlimited |
158 | amount of data without a callback ever being called as long as the line |
164 | amount of data without a callback ever being called as long as the line |
159 | isn't finished). |
165 | isn't finished). |
160 | |
166 | |
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167 | =item autocork => <boolean> |
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168 | |
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169 | When disabled (the default), then C<push_write> will try to immediately |
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170 | write the data to the handle if possible. This avoids having to register |
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171 | a write watcher and wait for the next event loop iteration, but can be |
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172 | inefficient if you write multiple small chunks (this disadvantage is |
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173 | usually avoided by your kernel's nagle algorithm, see C<low_delay>). |
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174 | |
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175 | When enabled, then writes will always be queued till the next event loop |
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176 | iteration. This is efficient when you do many small writes per iteration, |
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177 | but less efficient when you do a single write only. |
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178 | |
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179 | =item no_delay => <boolean> |
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180 | |
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181 | When doing small writes on sockets, your operating system kernel might |
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182 | wait a bit for more data before actually sending it out. This is called |
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183 | the Nagle algorithm, and usually it is beneficial. |
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184 | |
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185 | In some situations you want as low a delay as possible, which cna be |
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186 | accomplishd by setting this option to true. |
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187 | |
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188 | The default is your opertaing system's default behaviour, this option |
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189 | explicitly enables or disables it, if possible. |
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190 | |
161 | =item read_size => <bytes> |
191 | =item read_size => <bytes> |
162 | |
192 | |
163 | The default read block size (the amount of bytes this module will try to read |
193 | The default read block size (the amount of bytes this module will try to read |
164 | during each (loop iteration). Default: C<8192>. |
194 | during each (loop iteration). Default: C<8192>. |
165 | |
195 | |
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240 | } |
270 | } |
241 | |
271 | |
242 | $self->{_activity} = AnyEvent->now; |
272 | $self->{_activity} = AnyEvent->now; |
243 | $self->_timeout; |
273 | $self->_timeout; |
244 | |
274 | |
245 | $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; |
275 | $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; |
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276 | $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay}; |
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277 | |
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278 | $self->start_read |
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279 | if $self->{on_read}; |
246 | |
280 | |
247 | $self |
281 | $self |
248 | } |
282 | } |
249 | |
283 | |
250 | sub _shutdown { |
284 | sub _shutdown { |
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309 | |
343 | |
310 | =cut |
344 | =cut |
311 | |
345 | |
312 | sub on_timeout { |
346 | sub on_timeout { |
313 | $_[0]{on_timeout} = $_[1]; |
347 | $_[0]{on_timeout} = $_[1]; |
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348 | } |
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349 | |
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350 | =item $handle->autocork ($boolean) |
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351 | |
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352 | Enables or disables the current autocork behaviour (see C<autocork> |
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353 | constructor argument). |
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354 | |
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355 | =cut |
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356 | |
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357 | =item $handle->no_delay ($boolean) |
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358 | |
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359 | Enables or disables the C<no_delay> setting (see constructor argument of |
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360 | the same name for details). |
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361 | |
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362 | =cut |
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363 | |
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364 | sub no_delay { |
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365 | $_[0]{no_delay} = $_[1]; |
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366 | |
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367 | eval { |
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368 | local $SIG{__DIE__}; |
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369 | setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1]; |
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370 | }; |
314 | } |
371 | } |
315 | |
372 | |
316 | ############################################################################# |
373 | ############################################################################# |
317 | |
374 | |
318 | =item $handle->timeout ($seconds) |
375 | =item $handle->timeout ($seconds) |
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433 | $self->_error ($!, 1); |
490 | $self->_error ($!, 1); |
434 | } |
491 | } |
435 | }; |
492 | }; |
436 | |
493 | |
437 | # try to write data immediately |
494 | # try to write data immediately |
438 | $cb->(); |
495 | $cb->() unless $self->{autocork}; |
439 | |
496 | |
440 | # if still data left in wbuf, we need to poll |
497 | # if still data left in wbuf, we need to poll |
441 | $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) |
498 | $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) |
442 | if length $self->{wbuf}; |
499 | if length $self->{wbuf}; |
443 | }; |
500 | }; |
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590 | ways, the "simple" way, using only C<on_read> and the "complex" way, using |
647 | ways, the "simple" way, using only C<on_read> and the "complex" way, using |
591 | a queue. |
648 | a queue. |
592 | |
649 | |
593 | In the simple case, you just install an C<on_read> callback and whenever |
650 | In the simple case, you just install an C<on_read> callback and whenever |
594 | new data arrives, it will be called. You can then remove some data (if |
651 | new data arrives, it will be called. You can then remove some data (if |
595 | enough is there) from the read buffer (C<< $handle->rbuf >>) if you want |
652 | enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna |
596 | or not. |
653 | leave the data there if you want to accumulate more (e.g. when only a |
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654 | partial message has been received so far). |
597 | |
655 | |
598 | In the more complex case, you want to queue multiple callbacks. In this |
656 | In the more complex case, you want to queue multiple callbacks. In this |
599 | case, AnyEvent::Handle will call the first queued callback each time new |
657 | case, AnyEvent::Handle will call the first queued callback each time new |
600 | data arrives (also the first time it is queued) and removes it when it has |
658 | data arrives (also the first time it is queued) and removes it when it has |
601 | done its job (see C<push_read>, below). |
659 | done its job (see C<push_read>, below). |
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619 | # handle xml |
677 | # handle xml |
620 | }); |
678 | }); |
621 | }); |
679 | }); |
622 | }); |
680 | }); |
623 | |
681 | |
624 | Example 2: Implement a client for a protocol that replies either with |
682 | Example 2: Implement a client for a protocol that replies either with "OK" |
625 | "OK" and another line or "ERROR" for one request, and 64 bytes for the |
683 | and another line or "ERROR" for the first request that is sent, and 64 |
626 | second request. Due tot he availability of a full queue, we can just |
684 | bytes for the second request. Due to the availability of a queue, we can |
627 | pipeline sending both requests and manipulate the queue as necessary in |
685 | just pipeline sending both requests and manipulate the queue as necessary |
628 | the callbacks: |
686 | in the callbacks. |
629 | |
687 | |
630 | # request one |
688 | When the first callback is called and sees an "OK" response, it will |
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689 | C<unshift> another line-read. This line-read will be queued I<before> the |
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690 | 64-byte chunk callback. |
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691 | |
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692 | # request one, returns either "OK + extra line" or "ERROR" |
631 | $handle->push_write ("request 1\015\012"); |
693 | $handle->push_write ("request 1\015\012"); |
632 | |
694 | |
633 | # we expect "ERROR" or "OK" as response, so push a line read |
695 | # we expect "ERROR" or "OK" as response, so push a line read |
634 | $handle->push_read (line => sub { |
696 | $handle->push_read (line => sub { |
635 | # if we got an "OK", we have to _prepend_ another line, |
697 | # if we got an "OK", we have to _prepend_ another line, |
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642 | ... |
704 | ... |
643 | }); |
705 | }); |
644 | } |
706 | } |
645 | }); |
707 | }); |
646 | |
708 | |
647 | # request two |
709 | # request two, simply returns 64 octets |
648 | $handle->push_write ("request 2\015\012"); |
710 | $handle->push_write ("request 2\015\012"); |
649 | |
711 | |
650 | # simply read 64 bytes, always |
712 | # simply read 64 bytes, always |
651 | $handle->push_read (chunk => 64, sub { |
713 | $handle->push_read (chunk => 64, sub { |
652 | my $response = $_[1]; |
714 | my $response = $_[1]; |