DBD::Gofer::Transport:UseroContributed PDBD::Gofer::Transport::corostream(3pm)
NAME
DBD::Gofer::Transport::corostream - Async DBD::Gofer stream transport
using Coro and AnyEvent
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", ...);
DESCRIPTION
The BIG WIN from using Coro is that it enables the use of existing DBI
frameworks like DBIx::Class.
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.
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!
AUTHOR
Tim Bunce, <http://www.tim.bunce.name>
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 perlartistic.
SEE ALSO
DBD::Gofer::Transport::stream
DBD::Gofer
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.
perl v5.34.0 2022-0DBD::Gofer::Transport::corostream(3pm)
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