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   1  package DBD::Gofer::Transport::null;
   2  
   3  #   $Id: null.pm 10087 2007-10-16 12:42:37Z timbo $
   4  #
   5  #   Copyright (c) 2007, Tim Bunce, Ireland
   6  #
   7  #   You may distribute under the terms of either the GNU General Public
   8  #   License or the Artistic License, as specified in the Perl README file.
   9  
  10  use strict;
  11  use warnings;
  12  
  13  use base qw(DBD::Gofer::Transport::Base);
  14  
  15  use DBI::Gofer::Execute;
  16  
  17  our $VERSION = sprintf("0.%06d", q$Revision: 10087 $ =~ /(\d+)/o);
  18  
  19  __PACKAGE__->mk_accessors(qw(
  20      pending_response
  21      transmit_count
  22  )); 
  23  
  24  my $executor = DBI::Gofer::Execute->new();
  25  
  26  
  27  sub transmit_request_by_transport {
  28      my ($self, $request) = @_;
  29      $self->transmit_count( ($self->transmit_count()||0) + 1 ); # just for tests
  30  
  31      my $frozen_request = $self->freeze_request($request);
  32  
  33      # ...
  34      # the request is magically transported over to ... ourselves
  35      # ...
  36  
  37      my $response = $executor->execute_request( $self->thaw_request($frozen_request, undef, 1) );
  38  
  39      # put response 'on the shelf' ready for receive_response()
  40      $self->pending_response( $response );
  41  
  42      return undef;
  43  }
  44  
  45  
  46  sub receive_response_by_transport {
  47      my $self = shift;
  48  
  49      my $response = $self->pending_response;
  50  
  51      my $frozen_response = $self->freeze_response($response, undef, 1);
  52  
  53      # ...
  54      # the response is magically transported back to ... ourselves
  55      # ...
  56  
  57      return $self->thaw_response($frozen_response);
  58  }
  59  
  60  
  61  1;
  62  __END__
  63  
  64  =head1 NAME
  65  
  66  DBD::Gofer::Transport::null - DBD::Gofer client transport for testing
  67  
  68  =head1 SYNOPSIS
  69  
  70    my $original_dsn = "..."
  71    DBI->connect("dbi:Gofer:transport=null;dsn=$original_dsn",...)
  72  
  73  or, enable by setting the DBI_AUTOPROXY environment variable:
  74  
  75    export DBI_AUTOPROXY="dbi:Gofer:transport=null"
  76  
  77  =head1 DESCRIPTION
  78  
  79  Connect via DBD::Gofer but execute the requests within the same process.
  80  
  81  This is a quick and simple way to test applications for compatibility with the
  82  (few) restrictions that DBD::Gofer imposes.
  83  
  84  It also provides a simple, portable way for the DBI test suite to be used to
  85  test DBD::Gofer on all platforms with no setup.
  86  
  87  Also, by measuring the difference in performance between normal connections and
  88  connections via C<dbi:Gofer:transport=null> the basic cost of using DBD::Gofer
  89  can be measured. Furthermore, the additional cost of more advanced transports can be 
  90  isolated by comparing their performance with the null transport.
  91  
  92  The C<t/85gofer.t> script in the DBI distribution includes a comparative benchmark.
  93  
  94  =head1 AUTHOR
  95  
  96  Tim Bunce, L<http://www.tim.bunce.name>
  97  
  98  =head1 LICENCE AND COPYRIGHT
  99  
 100  Copyright (c) 2007, Tim Bunce, Ireland. All rights reserved.
 101  
 102  This module is free software; you can redistribute it and/or
 103  modify it under the same terms as Perl itself. See L<perlartistic>.
 104  
 105  =head1 SEE ALSO
 106  
 107  L<DBD::Gofer::Transport::Base>
 108  
 109  L<DBD::Gofer>
 110  
 111  =cut