1 |
=head1 NAME |
2 |
|
3 |
AnyEvent::DBI - asynchronous DBI access |
4 |
|
5 |
=head1 SYNOPSIS |
6 |
|
7 |
use AnyEvent::DBI; |
8 |
|
9 |
my $cv = AnyEvent->condvar; |
10 |
|
11 |
my $dbh = new AnyEvent::DBI "DBI:SQLite:dbname=test.db", "", ""; |
12 |
|
13 |
$dbh->exec ("select * from test where num=?", 10, sub { |
14 |
my ($dbh, $rows, $rv) = @_; |
15 |
|
16 |
$#_ or die "failure: $@"; |
17 |
|
18 |
print "@$_\n" |
19 |
for @$rows; |
20 |
|
21 |
$cv->broadcast; |
22 |
}); |
23 |
|
24 |
# asynchronously do sth. else here |
25 |
|
26 |
$cv->wait; |
27 |
|
28 |
=head1 DESCRIPTION |
29 |
|
30 |
This module is an L<AnyEvent> user, you need to make sure that you use and |
31 |
run a supported event loop. |
32 |
|
33 |
This module implements asynchronous DBI access by forking or executing |
34 |
separate "DBI-Server" processes and sending them requests. |
35 |
|
36 |
It means that you can run DBI requests in parallel to other tasks. |
37 |
|
38 |
The overhead for very simple statements ("select 0") is somewhere |
39 |
around 120% to 200% (dual/single core CPU) compared to an explicit |
40 |
prepare_cached/execute/fetchrow_arrayref/finish combination. |
41 |
|
42 |
=head2 ERROR HANDLING |
43 |
|
44 |
This module defines a number of functions that accept a callback |
45 |
argument. All callbacks used by this module get their AnyEvent::DBI handle |
46 |
object passed as first argument. |
47 |
|
48 |
If the request was successful, then there will be more arguments, |
49 |
otherwise there will only be the C<$dbh> argument and C<$@> contains an |
50 |
error message. |
51 |
|
52 |
A convinient way to check whether an error occured is to check C<$#_> - |
53 |
if that is true, then the function was successful, otherwise there was an |
54 |
error. |
55 |
|
56 |
=cut |
57 |
|
58 |
package AnyEvent::DBI; |
59 |
|
60 |
use strict qw(vars subs); |
61 |
no warnings; |
62 |
|
63 |
use Carp; |
64 |
use Socket (); |
65 |
use Scalar::Util (); |
66 |
use Storable (); |
67 |
|
68 |
use DBI (); |
69 |
|
70 |
use AnyEvent (); |
71 |
use AnyEvent::Util (); |
72 |
|
73 |
use Errno (); |
74 |
use Fcntl (); |
75 |
use POSIX (); |
76 |
|
77 |
our $VERSION = '2.0'; |
78 |
|
79 |
our $FD_MAX = eval { POSIX::sysconf (&POSIX::_SC_OPEN_MAX) - 1 } || 1023; |
80 |
|
81 |
# this is the forked server code, could/should be bundled as it's own file |
82 |
|
83 |
our $DBH; |
84 |
|
85 |
sub req_open { |
86 |
my (undef, $dbi, $user, $pass, %attr) = @{+shift}; |
87 |
|
88 |
$DBH = DBI->connect ($dbi, $user, $pass, \%attr) or die $DBI::errstr; |
89 |
|
90 |
[1, 1] |
91 |
} |
92 |
|
93 |
sub req_exec { |
94 |
my (undef, $st, @args) = @{+shift}; |
95 |
my $sth = $DBH->prepare_cached ($st, undef, 1) |
96 |
or die [$DBI::errstr]; |
97 |
|
98 |
my $rv = $sth->execute (@args) |
99 |
or die [$sth->errstr]; |
100 |
|
101 |
[1, $sth->{NUM_OF_FIELDS} ? $sth->fetchall_arrayref : undef, $rv] |
102 |
} |
103 |
|
104 |
sub req_attr { |
105 |
my (undef, $attr_name, @attr_val) = @{+shift}; |
106 |
|
107 |
$DBH->{$attr_name} = $attr_val[0] |
108 |
if @attr_val; |
109 |
|
110 |
[1, $DBH->{$attr_name}] |
111 |
} |
112 |
|
113 |
sub req_begin_work { |
114 |
[1, $DBH->begin_work or die [$DBI::errstr]] |
115 |
} |
116 |
|
117 |
sub req_commit { |
118 |
[1, $DBH->commit or die [$DBI::errstr]] |
119 |
} |
120 |
|
121 |
sub req_rollback { |
122 |
[1, $DBH->rollback or die [$DBI::errstr]] |
123 |
} |
124 |
|
125 |
sub req_func { |
126 |
my (undef, $arg_string, $function) = @{+shift}; |
127 |
my @args = eval $arg_string; |
128 |
|
129 |
die "error evaling \$dbh->func() arg_string: $@" |
130 |
if $@; |
131 |
|
132 |
my $rc = $DBH->func (@args, $function); |
133 |
return [1, $rc, $DBI::err, $DBI::errstr]; |
134 |
} |
135 |
|
136 |
sub serve_fh($$) { |
137 |
my ($fh, $version) = @_; |
138 |
|
139 |
if ($VERSION != $version) { |
140 |
syswrite $fh, |
141 |
pack "L/a*", |
142 |
Storable::freeze |
143 |
[undef, "AnyEvent::DBI version mismatch ($VERSION vs. $version)"]; |
144 |
return; |
145 |
} |
146 |
|
147 |
eval { |
148 |
my $rbuf; |
149 |
|
150 |
while () { |
151 |
sysread $fh, $rbuf, 16384, length $rbuf |
152 |
or last; |
153 |
|
154 |
while () { |
155 |
my $len = unpack "L", $rbuf; |
156 |
|
157 |
# full request available? |
158 |
last unless $len && $len + 4 <= length $rbuf; |
159 |
|
160 |
my $req = Storable::thaw substr $rbuf, 4; |
161 |
substr $rbuf, 0, $len + 4, ""; # remove length + request |
162 |
|
163 |
my $wbuf = eval { pack "L/a*", Storable::freeze $req->[0]($req) }; |
164 |
$wbuf = pack "L/a*", Storable::freeze [undef, ref $@ ? ("$@->[0]", $@->[1]) : ("$@", 1)] |
165 |
if $@; |
166 |
|
167 |
for (my $ofs = 0; $ofs < length $wbuf; ) { |
168 |
$ofs += (syswrite $fh, substr $wbuf, $ofs |
169 |
or die "unable to write results"); |
170 |
} |
171 |
} |
172 |
} |
173 |
}; |
174 |
} |
175 |
|
176 |
sub serve_fd($$) { |
177 |
open my $fh, ">>&=$_[0]" |
178 |
or die "Couldn't open server file descriptor: $!"; |
179 |
|
180 |
serve_fh $fh, $_[1]; |
181 |
} |
182 |
|
183 |
=head2 METHODS |
184 |
|
185 |
=over 4 |
186 |
|
187 |
=item $dbh = new AnyEvent::DBI $database, $user, $pass, [key => value]... |
188 |
|
189 |
Returns a database handle for the given database. Each database handle |
190 |
has an associated server process that executes statements in order. If |
191 |
you want to run more than one statement in parallel, you need to create |
192 |
additional database handles. |
193 |
|
194 |
The advantage of this approach is that transactions work as state is |
195 |
preserved. |
196 |
|
197 |
Example: |
198 |
|
199 |
$dbh = new AnyEvent::DBI |
200 |
"DBI:mysql:test;mysql_read_default_file=/root/.my.cnf", "", ""; |
201 |
|
202 |
Additional key-value pairs can be used to adjust behaviour: |
203 |
|
204 |
=over 4 |
205 |
|
206 |
=item on_error => $callback->($dbh, $filename, $line, $fatal) |
207 |
|
208 |
When an error occurs, then this callback will be invoked. On entry, C<$@> |
209 |
is set to the error message. C<$filename> and C<$line> is where the |
210 |
original request was submitted. |
211 |
|
212 |
If the fatal argument is true then the database connection is shut down |
213 |
and your database handle became invalid. In addition to invoking the |
214 |
C<on_error> callback, all of your queued request callbacks are called |
215 |
without only the C<$dbh> argument. |
216 |
|
217 |
If omitted, then C<die> will be called on any errors, fatal or not. |
218 |
|
219 |
=item on_connect => $callback->($dbh[, $success]) |
220 |
|
221 |
If you supply an C<on_connect> callback, then this callback will be |
222 |
invoked after the database connect attempt. If the connection succeeds, |
223 |
C<$success> is true, otherwise it is missing and C<$@> contains the |
224 |
C<$DBI::errstr>. |
225 |
|
226 |
Regardless of whether C<on_connect> is supplied, connect errors will result in |
227 |
C<on_error> being called. However, if no C<on_connect> callback is supplied, then |
228 |
connection errors are considered fatal. The client will C<die> and the C<on_error> |
229 |
callback will be called with C<$fatal> true. |
230 |
|
231 |
When on_connect is supplied, connect error are not fatal and AnyEvent::DBI |
232 |
will not C<die>. You still cannot, however, use the $dbh object you |
233 |
received from C<new> to make requests. |
234 |
|
235 |
=item exec_server => 1 |
236 |
|
237 |
If you supply an C<exec_server> argument, then the DBI server process will |
238 |
fork and exec another perl interpreter (using C<$^X>) with just the |
239 |
AnyEvent::DBI proxy running. This will provide the cleanest possible porxy |
240 |
for your database server. |
241 |
|
242 |
If you do not supply the C<exec_server> argument (or supply it with a |
243 |
false value) then the traditional method of starting the server by forking |
244 |
the current process is used. The forked interpreter will try to clean |
245 |
itself up by calling POSIX::close on all file descriptors except STDIN, |
246 |
STDOUT, and STDERR (and the socket it uses to communicate with the cilent, |
247 |
of course). |
248 |
|
249 |
=item timeout => seconds |
250 |
|
251 |
If you supply a timeout parameter (fractional values are supported), then |
252 |
a timer is started any time the DBI handle expects a response from the |
253 |
server. This includes connection setup as well as requests made to the |
254 |
backend. The timeout spans the duration from the moment the first data |
255 |
is written (or queued to be written) until all expected responses are |
256 |
returned, but is postponed for "timeout" seconds each time more data is |
257 |
returned from the server. If the timer ever goes off then a fatal error is |
258 |
generated. If you have an C<on_error> handler installed, then it will be |
259 |
called, otherwise your program will die(). |
260 |
|
261 |
When altering your databases with timeouts it is wise to use |
262 |
transactions. If you quit due to timeout while performing insert, update |
263 |
or schema-altering commands you can end up not knowing if the action was |
264 |
submitted to the database, complicating recovery. |
265 |
|
266 |
Timeout errors are always fatal. |
267 |
|
268 |
=back |
269 |
|
270 |
Any additional key-value pairs will be rolled into a hash reference |
271 |
and passed as the final argument to the C<< DBI->connect (...) >> |
272 |
call. For example, to supress errors on STDERR and send them instead to an |
273 |
AnyEvent::Handle you could do: |
274 |
|
275 |
$dbh = new AnyEvent::DBI |
276 |
"DBI:mysql:test;mysql_read_default_file=/root/.my.cnf", "", "", |
277 |
PrintError => 0, |
278 |
on_error => sub { |
279 |
$log_handle->push_write ("DBI Error: $@ at $_[1]:$_[2]\n"); |
280 |
}; |
281 |
|
282 |
=cut |
283 |
|
284 |
# stupid Storable autoloading, total loss-loss situation |
285 |
Storable::thaw Storable::freeze []; |
286 |
|
287 |
sub new { |
288 |
my ($class, $dbi, $user, $pass, %arg) = @_; |
289 |
|
290 |
my ($client, $server) = AnyEvent::Util::portable_socketpair |
291 |
or croak "unable to create Anyevent::DBI communications pipe: $!"; |
292 |
|
293 |
my %dbi_args = %arg; |
294 |
delete @dbi_args{qw(on_connect on_error timeout exec_server)}; |
295 |
|
296 |
my $self = bless \%arg, $class; |
297 |
$self->{fh} = $client; |
298 |
|
299 |
AnyEvent::Util::fh_nonblocking $client, 1; |
300 |
|
301 |
my $rbuf; |
302 |
my @caller = (caller)[1,2]; # the "default" caller |
303 |
|
304 |
{ |
305 |
Scalar::Util::weaken (my $self = $self); |
306 |
|
307 |
$self->{rw} = AnyEvent->io (fh => $client, poll => "r", cb => sub { |
308 |
return unless $self; |
309 |
|
310 |
$self->{last_activity} = AnyEvent->now; |
311 |
|
312 |
my $len = sysread $client, $rbuf, 65536, length $rbuf; |
313 |
|
314 |
if ($len > 0) { |
315 |
# we received data, so reset the timer |
316 |
|
317 |
while () { |
318 |
my $len = unpack "L", $rbuf; |
319 |
|
320 |
# full response available? |
321 |
last unless $len && $len + 4 <= length $rbuf; |
322 |
|
323 |
my $res = Storable::thaw substr $rbuf, 4; |
324 |
substr $rbuf, 0, $len + 4, ""; # remove length + request |
325 |
|
326 |
last unless $self; |
327 |
my $req = shift @{ $self->{queue} }; |
328 |
|
329 |
if (defined $res->[0]) { |
330 |
$res->[0] = $self; |
331 |
$req->[0](@$res); |
332 |
} else { |
333 |
my $cb = shift @$req; |
334 |
local $@ = $res->[1]; |
335 |
$cb->($self); |
336 |
$self->_error ($res->[1], @$req, $res->[2]) # error, request record, is_fatal |
337 |
if $self; # cb() could have deleted it |
338 |
} |
339 |
|
340 |
# no more queued requests, so become idle |
341 |
undef $self->{last_activity} |
342 |
if $self && !@{ $self->{queue} }; |
343 |
} |
344 |
|
345 |
} elsif (defined $len) { |
346 |
# todo, caller? |
347 |
$self->_error ("unexpected eof", @caller, 1); |
348 |
} elsif ($! != Errno::EAGAIN) { |
349 |
# todo, caller? |
350 |
$self->_error ("read error: $!", @caller, 1); |
351 |
} |
352 |
}); |
353 |
|
354 |
$self->{tw_cb} = sub { |
355 |
if ($self->{timeout} && $self->{last_activity}) { |
356 |
if (AnyEvent->now > $self->{last_activity} + $self->{timeout}) { |
357 |
# we did time out |
358 |
my $req = $self->{queue}[0]; |
359 |
$self->_error (timeout => $req->[1], $req->[2], 1); # timeouts are always fatal |
360 |
} else { |
361 |
# we need to re-set the timeout watcher |
362 |
$self->{tw} = AnyEvent->timer ( |
363 |
after => $self->{last_activity} + $self->{timeout} - AnyEvent->now, |
364 |
cb => $self->{tw_cb}, |
365 |
); |
366 |
Scalar::Util::weaken $self; |
367 |
} |
368 |
} else { |
369 |
# no timeout check wanted, or idle |
370 |
undef $self->{tw}; |
371 |
} |
372 |
}; |
373 |
|
374 |
$self->{ww_cb} = sub { |
375 |
return unless $self; |
376 |
|
377 |
$self->{last_activity} = AnyEvent->now; |
378 |
|
379 |
my $len = syswrite $client, $self->{wbuf} |
380 |
or return delete $self->{ww}; |
381 |
|
382 |
substr $self->{wbuf}, 0, $len, ""; |
383 |
}; |
384 |
} |
385 |
|
386 |
my $pid = fork; |
387 |
|
388 |
if ($pid) { |
389 |
# parent |
390 |
close $server; |
391 |
} elsif (defined $pid) { |
392 |
# child |
393 |
my $serv_fno = fileno $server; |
394 |
|
395 |
if ($self->{exec_server}) { |
396 |
fcntl $server, &Fcntl::F_SETFD, 0; # don't close the server side |
397 |
exec {$^X} |
398 |
"$0 dbi slave", |
399 |
-e => "require shift; AnyEvent::DBI::serve_fd ($serv_fno, $VERSION)", |
400 |
$INC{"AnyEvent/DBI.pm"}; |
401 |
POSIX::_exit 124; |
402 |
} else { |
403 |
($_ != $serv_fno) && POSIX::close $_ |
404 |
for $^F+1..$FD_MAX; |
405 |
serve_fh $server, $VERSION; |
406 |
|
407 |
# no other way on the broken windows platform, even this leaks |
408 |
# memory and might fail. |
409 |
kill 9, $$ |
410 |
if AnyEvent::WIN32; |
411 |
|
412 |
# and this kills the parent process on windows |
413 |
POSIX::_exit 0; |
414 |
} |
415 |
} else { |
416 |
croak "fork: $!"; |
417 |
} |
418 |
|
419 |
$self->{child_pid} = $pid; |
420 |
|
421 |
$self->_req ( |
422 |
($self->{on_connect} ? $self->{on_connect} : sub { }), |
423 |
(caller)[1,2], |
424 |
req_open => $dbi, $user, $pass, %dbi_args |
425 |
); |
426 |
|
427 |
$self |
428 |
} |
429 |
|
430 |
sub _server_pid { |
431 |
shift->{child_pid} |
432 |
} |
433 |
|
434 |
sub kill_child { |
435 |
my $self = shift; |
436 |
my $child_pid = delete $self->{child_pid}; |
437 |
if ($child_pid) { |
438 |
# send SIGKILL in two seconds |
439 |
my $murder_timer = AnyEvent->timer ( |
440 |
after => 2, |
441 |
cb => sub { |
442 |
kill 9, $child_pid; |
443 |
}, |
444 |
); |
445 |
|
446 |
# reap process |
447 |
my $kid_watcher; $kid_watcher = AnyEvent->child ( |
448 |
pid => $child_pid, |
449 |
cb => sub { |
450 |
# just hold on to this so it won't go away |
451 |
undef $kid_watcher; |
452 |
# cancel SIGKILL |
453 |
undef $murder_timer; |
454 |
}, |
455 |
); |
456 |
|
457 |
close $self->{fh}; |
458 |
} |
459 |
} |
460 |
|
461 |
sub DESTROY { |
462 |
shift->kill_child; |
463 |
} |
464 |
|
465 |
sub _error { |
466 |
my ($self, $error, $filename, $line, $fatal) = @_; |
467 |
|
468 |
if ($fatal) { |
469 |
delete $self->{tw}; |
470 |
delete $self->{rw}; |
471 |
delete $self->{ww}; |
472 |
delete $self->{fh}; |
473 |
|
474 |
# for fatal errors call all enqueued callbacks with error |
475 |
while (my $req = shift @{$self->{queue}}) { |
476 |
local $@ = $error; |
477 |
$req->[0]->($self); |
478 |
} |
479 |
$self->kill_child; |
480 |
} |
481 |
|
482 |
local $@ = $error; |
483 |
|
484 |
if ($self->{on_error}) { |
485 |
$self->{on_error}($self, $filename, $line, $fatal) |
486 |
} else { |
487 |
die "$error at $filename, line $line\n"; |
488 |
} |
489 |
} |
490 |
|
491 |
=item $dbh->on_error ($cb->($dbh, $filename, $line, $fatal)) |
492 |
|
493 |
Sets (or clears, with C<undef>) the C<on_error> handler. |
494 |
|
495 |
=cut |
496 |
|
497 |
sub on_error { |
498 |
$_[0]{on_error} = $_[1]; |
499 |
} |
500 |
|
501 |
=item $dbh->timeout ($seconds) |
502 |
|
503 |
Sets (or clears, with C<undef>) the database timeout. Useful to extend the |
504 |
timeout when you are about to make a really long query. |
505 |
|
506 |
=cut |
507 |
|
508 |
sub timeout { |
509 |
my ($self, $timeout) = @_; |
510 |
|
511 |
$self->{timeout} = $timeout; |
512 |
|
513 |
# reschedule timer if one was running |
514 |
$self->{tw_cb}->(); |
515 |
} |
516 |
|
517 |
sub _req { |
518 |
my ($self, $cb, $filename, $line) = splice @_, 0, 4, (); |
519 |
|
520 |
unless ($self->{fh}) { |
521 |
local $@ = my $err = 'no database connection'; |
522 |
$cb->($self); |
523 |
$self->_error ($err, $filename, $line, 1); |
524 |
return; |
525 |
} |
526 |
|
527 |
push @{ $self->{queue} }, [$cb, $filename, $line]; |
528 |
|
529 |
# re-start timeout if necessary |
530 |
if ($self->{timeout} && !$self->{tw}) { |
531 |
$self->{last_activity} = AnyEvent->now; |
532 |
$self->{tw_cb}->(); |
533 |
} |
534 |
|
535 |
$self->{wbuf} .= pack "L/a*", Storable::freeze \@_; |
536 |
|
537 |
unless ($self->{ww}) { |
538 |
my $len = syswrite $self->{fh}, $self->{wbuf}; |
539 |
substr $self->{wbuf}, 0, $len, ""; |
540 |
|
541 |
# still any left? then install a write watcher |
542 |
$self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $self->{ww_cb}) |
543 |
if length $self->{wbuf}; |
544 |
} |
545 |
} |
546 |
|
547 |
=item $dbh->exec ("statement", @args, $cb->($dbh, \@rows, $rv)) |
548 |
|
549 |
Executes the given SQL statement with placeholders replaced by |
550 |
C<@args>. The statement will be prepared and cached on the server side, so |
551 |
using placeholders is extremely important. |
552 |
|
553 |
The callback will be called with a weakened AnyEvent::DBI object as the |
554 |
first argument and the result of C<fetchall_arrayref> as (or C<undef> |
555 |
if the statement wasn't a select statement) as the second argument. |
556 |
|
557 |
Third argument is the return value from the C<< DBI->execute >> method |
558 |
call. |
559 |
|
560 |
If an error occurs and the C<on_error> callback returns, then only C<$dbh> |
561 |
will be passed and C<$@> contains the error message. |
562 |
|
563 |
=item $dbh->attr ($attr_name[, $attr_value], $cb->($dbh, $new_value)) |
564 |
|
565 |
An accessor for the handle attributes, such as C<AutoCommit>, |
566 |
C<RaiseError>, C<PrintError> and so on. If you provide an C<$attr_value> |
567 |
(which might be C<undef>), then the given attribute will be set to that |
568 |
value. |
569 |
|
570 |
The callback will be passed the database handle and the attribute's value |
571 |
if successful. |
572 |
|
573 |
If an error occurs and the C<on_error> callback returns, then only C<$dbh> |
574 |
will be passed and C<$@> contains the error message. |
575 |
|
576 |
=item $dbh->begin_work ($cb->($dbh[, $rc])) |
577 |
|
578 |
=item $dbh->commit ($cb->($dbh[, $rc])) |
579 |
|
580 |
=item $dbh->rollback ($cb->($dbh[, $rc])) |
581 |
|
582 |
The begin_work, commit, and rollback methods expose the equivalent |
583 |
transaction control method of the DBI driver. On success, C<$rc> is true. |
584 |
|
585 |
If an error occurs and the C<on_error> callback returns, then only C<$dbh> |
586 |
will be passed and C<$@> contains the error message. |
587 |
|
588 |
=item $dbh->func ('string_which_yields_args_when_evaled', $func_name, $cb->($dbh, $rc, $dbi_err, $dbi_errstr)) |
589 |
|
590 |
This gives access to database driver private methods. Because they |
591 |
are not standard you cannot always depend on the value of C<$rc> or |
592 |
C<$dbi_err>. Check the documentation for your specific driver/function |
593 |
combination to see what it returns. |
594 |
|
595 |
Note that the first argument will be eval'ed to produce the argument list to |
596 |
the func() method. This must be done because the serialization protocol |
597 |
between the AnyEvent::DBI server process and your program does not support the |
598 |
passage of closures. |
599 |
|
600 |
Here's an example to extend the query language in SQLite so it supports an |
601 |
intstr() function: |
602 |
|
603 |
$cv = AnyEvent->condvar; |
604 |
$dbh->func ( |
605 |
q{ |
606 |
instr => 2, sub { |
607 |
my ($string, $search) = @_; |
608 |
return index $string, $search; |
609 |
}, |
610 |
}, |
611 |
create_function => sub { |
612 |
return $cv->send ($@) |
613 |
unless $#_; |
614 |
$cv->send (undef, @_[1,2,3]); |
615 |
} |
616 |
); |
617 |
|
618 |
my ($err,$rc,$errcode,$errstr) = $cv->recv; |
619 |
|
620 |
die $err if defined $err; |
621 |
die "EVAL failed: $errstr" |
622 |
if $errcode; |
623 |
|
624 |
# otherwise, we can ignore $rc and $errcode for this particular func |
625 |
|
626 |
=cut |
627 |
|
628 |
for my $cmd_name (qw(exec attr begin_work commit rollback func)) { |
629 |
eval 'sub ' . $cmd_name . '{ |
630 |
my $cb = pop; |
631 |
splice @_, 1, 0, $cb, (caller)[1,2], "req_' . $cmd_name . '"; |
632 |
&_req |
633 |
}'; |
634 |
} |
635 |
|
636 |
=back |
637 |
|
638 |
=head1 SEE ALSO |
639 |
|
640 |
L<AnyEvent>, L<DBI>, L<Coro::Mysql>. |
641 |
|
642 |
=head1 AUTHOR |
643 |
|
644 |
Marc Lehmann <schmorp@schmorp.de> |
645 |
http://home.schmorp.de/ |
646 |
|
647 |
Adam Rosenstein <adam@redcondor.com> |
648 |
http://www.redcondor.com/ |
649 |
|
650 |
=cut |
651 |
|
652 |
1; |
653 |
|