NAME

DashProfiler::Auto - Creates and imports a predeclared DashProfiler sampler

SYNOPSIS

Measure the time spent between creating a sample object and destroying it:

  $ perl -MDashProfiler::Auto -w -e '$a=auto_profiler("foobar"); sleep 1; undef $a'
  auto > -e > foobar: dur=1.000231 count=1 (max=1.000231 avg=1.000231)
  auto > other > other: dur=0.000451 count=1 (max=0.000451 avg=0.000451)

The leading "auto > -e > foobar" portion shows the name of the profiler (auto), the name of the file that called it (in this case "-e" because the code was given on the command line), and finally the argument given to auto_profiler().

The time shown as "auto > other > other" is all the 'other' time spent by the program that isn't included in the samples taken.

This next example shows use of the 'context2' parameter to auto_profiler() and also how to samples can overlap:

  $ perl -MDashProfiler::Auto -w -e '
      sub fib {
          my $n = shift;
          return $n if $n < 2;
          my $s = auto_profiler($n, undef, 1);
          fib($n-1) + fib($n-2);
      }
      fib(7)
  '
  auto > -e > 2: dur=0.000054 count=8 (max=0.000013 avg=0.000002)
  auto > -e > 3: dur=0.000137 count=5 (max=0.000046 avg=0.000009)
  auto > -e > 4: dur=0.000197 count=3 (max=0.000085 avg=0.000028)
  auto > -e > 5: dur=0.000245 count=2 (max=0.000139 avg=0.000069)
  auto > -e > 6: dur=0.000226 count=1 (max=0.000226 avg=0.000226)
  auto > -e > 7: dur=0.000370 count=1 (max=0.000370 avg=0.000370)

The timing for "other" isn't shown because if any samples do overlap then the period_exclusive summary is disabled.

DESCRIPTION

The DashProfiler::Auto is designed for quick temporary use of DashProfiler. It avoids the need to create a profile by creating one for you with a typical configuration, and defining a sample period from the time the module was loaded to the time the program exits.

Profiler Configuration

The default configuration is:

    my $auto = DashProfiler->add_profile( auto => {
        period_exclusive => 'other',
        flush_hook => sub {
            my ($self, $dbi_profile_name) = @_;
            warn $_ for $self->profile_as_text($dbi_profile_name);
            return $self->reset_profile_data($dbi_profile_name);
        },
    });

* period_exclusive enables the automatic addition of a sample which measures the time not accounted for by the samples. See "Sample Periods" below.

* flush_hook uses warn() to write out the profile data, then resets (discards) the data.

Sample Periods

When the modle is loaded it creates the auto profile and calls

    $auto->start_sample_period();

It also defines an END block which does

    $auto->end_sample_period();
    $auto->flush;

so the sample period runs from the time the module was loaded (typically when the program started running) through to the time the program exits.

Imported Samplers

Using DashProfile::Auto in a file like this:

    use DashProfiler::Auto;

is almost identical to this:

    use DashProfiler::Import auto_profiler => [ basename(__FILE__) ];

AUTHOR

DashProfiler by Tim Bunce, http://www.tim.bunce.name and http://blog.timbunce.org

COPYRIGHT

The DashProfiler distribution is Copyright (c) 2007-2008 Tim Bunce. Ireland. All rights reserved.

You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.