JezK
Edit File: corostream.pm
package DBD::Gofer::Transport::corostream; use strict; use warnings; use Carp; use Coro::Select; # a slow but coro-aware replacement for CORE::select (global effect!) use Coro; use Coro::Handle; use base qw(DBD::Gofer::Transport::stream); # XXX ensure DBI_PUREPERL for parent doesn't pass to child sub start_pipe_command { local $ENV{DBI_PUREPERL} = $ENV{DBI_PUREPERL_COROCHILD}; # typically undef my $connection = shift->SUPER::start_pipe_command(@_); return $connection; } 1; __END__ =head1 NAME DBD::Gofer::Transport::corostream - Async DBD::Gofer stream transport using Coro and AnyEvent =head1 SYNOPSIS DBI_AUTOPROXY="dbi:Gofer:transport=corostream" perl some-perl-script-using-dbi.pl or $dsn = ...; # the DSN for the driver and database you want to use $dbh = DBI->connect("dbi:Gofer:transport=corostream;dsn=$dsn", ...); =head1 DESCRIPTION The I<BIG WIN> from using L<Coro> is that it enables the use of existing DBI frameworks like L<DBIx::Class>. =head1 KNOWN ISSUES AND LIMITATIONS - Uses Coro::Select so alters CORE::select globally Parent class probably needs refactoring to enable a more encapsulated approach. - Doesn't prevent multiple concurrent requests Probably just needs a per-connection semaphore - Coro has many caveats. Caveat emptor. =head1 STATUS THIS IS CURRENTLY JUST A PROOF-OF-CONCEPT IMPLEMENTATION FOR EXPERIMENTATION. Please note that I have no plans to develop this code further myself. I'd very much welcome contributions. Interested? Let me know! =head1 AUTHOR Tim Bunce, L<http://www.tim.bunce.name> =head1 LICENCE AND COPYRIGHT Copyright (c) 2010, Tim Bunce, Ireland. All rights reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See L<perlartistic>. =head1 SEE ALSO L<DBD::Gofer::Transport::stream> L<DBD::Gofer> =head1 APPENDIX Example code: #!perl use strict; use warnings; use Time::HiRes qw(time); BEGIN { $ENV{PERL_ANYEVENT_STRICT} = 1; $ENV{PERL_ANYEVENT_VERBOSE} = 1; } use AnyEvent; BEGIN { $ENV{DBI_TRACE} = 0; $ENV{DBI_GOFER_TRACE} = 0; $ENV{DBD_GOFER_TRACE} = 0; }; use DBI; $ENV{DBI_AUTOPROXY} = 'dbi:Gofer:transport=corostream'; my $ticker = AnyEvent->timer( after => 0, interval => 0.1, cb => sub { warn sprintf "-tick- %.2f\n", time } ); warn "connecting...\n"; my $dbh = DBI->connect("dbi:NullP:"); warn "...connected\n"; for (1..3) { warn "entering DBI...\n"; $dbh->do("sleep 0.3"); # pseudo-sql understood by the DBD::NullP driver warn "...returned\n"; } warn "done."; Example output: $ perl corogofer.pl connecting... -tick- 1293631437.14 -tick- 1293631437.14 ...connected entering DBI... -tick- 1293631437.25 -tick- 1293631437.35 -tick- 1293631437.45 -tick- 1293631437.55 ...returned entering DBI... -tick- 1293631437.66 -tick- 1293631437.76 -tick- 1293631437.86 ...returned entering DBI... -tick- 1293631437.96 -tick- 1293631438.06 -tick- 1293631438.16 ...returned done. at corogofer.pl line 39. You can see that the timer callback is firing while the code 'waits' inside the do() method for the response from the database. Normally that would block. =cut