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✏️ Editing: DBD::Gofer::Transport::corostream.3pm

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.\" ========================================================================
.\"
.IX Title "DBD::Gofer::Transport::corostream 3"
.TH DBD::Gofer::Transport::corostream 3 "2013-04-04" "perl v5.26.3" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.SH "NAME"
DBD::Gofer::Transport::corostream \- Async DBD::Gofer stream transport using Coro and AnyEvent
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&   DBI_AUTOPROXY="dbi:Gofer:transport=corostream" perl some\-perl\-script\-using\-dbi.pl
.Ve
.PP
or
.PP
.Vb 2
\&   $dsn = ...; # the DSN for the driver and database you want to use
\&   $dbh = DBI\->connect("dbi:Gofer:transport=corostream;dsn=$dsn", ...);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
The \fI\s-1BIG WIN\s0\fR from using Coro is that it enables the use of existing
\&\s-1DBI\s0 frameworks like DBIx::Class.
.SH "KNOWN ISSUES AND LIMITATIONS"
.IX Header "KNOWN ISSUES AND LIMITATIONS"
.Vb 2
\&  \- Uses Coro::Select so alters CORE::select globally
\&    Parent class probably needs refactoring to enable a more encapsulated approach.
\&
\&  \- Doesn\*(Aqt prevent multiple concurrent requests
\&    Probably just needs a per\-connection semaphore
\&
\&  \- Coro has many caveats. Caveat emptor.
.Ve
.SH "STATUS"
.IX Header "STATUS"
\&\s-1THIS IS CURRENTLY JUST A\s0 PROOF-OF-CONCEPT \s-1IMPLEMENTATION FOR EXPERIMENTATION.\s0
.PP
Please note that I have no plans to develop this code further myself.
I'd very much welcome contributions. Interested? Let me know!
.SH "AUTHOR"
.IX Header "AUTHOR"
Tim Bunce, <http://www.tim.bunce.name>
.SH "LICENCE AND COPYRIGHT"
.IX Header "LICENCE AND COPYRIGHT"
Copyright (c) 2010, Tim Bunce, Ireland. All rights reserved.
.PP
This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself. See perlartistic.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
DBD::Gofer::Transport::stream
.PP
DBD::Gofer
.SH "APPENDIX"
.IX Header "APPENDIX"
Example code:
.PP
.Vb 1
\&    #!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} = \*(Aqdbi:Gofer:transport=corostream\*(Aq;
\&
\&    my $ticker = AnyEvent\->timer( after => 0, interval => 0.1, cb => sub {
\&        warn sprintf "\-tick\- %.2f\en", time
\&    } );
\&
\&    warn "connecting...\en";
\&    my $dbh = DBI\->connect("dbi:NullP:");
\&    warn "...connected\en";
\&
\&    for (1..3) {
\&        warn "entering DBI...\en";
\&        $dbh\->do("sleep 0.3"); # pseudo\-sql understood by the DBD::NullP driver
\&        warn "...returned\en";
\&    }
\&
\&    warn "done.";
.Ve
.PP
Example output:
.PP
.Vb 10
\&    $ 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.
.Ve
.PP
You can see that the timer callback is firing while the code 'waits' inside the
\&\fBdo()\fR method for the response from the database. Normally that would block.

MR SKB