=head1 NAME

Misc::Stopwatch - Measure elapsed time


=head1 SYNOPSIS


  #!/usr/bin/perl
  use Misc::Stopwatch;
  my $sw = Misc::Stopwatch->new()->start();
  for (1 .. 3) {
    sleep 1;
    $sw->lap();
  }
  $sw->stop();
  printf "Lap 1: %f\n", $sw->elapsed(1);
  printf "Lap 2: %f\n", $sw->elapsed(2);
  printf "Lap 3: %f\n", $sw->elapsed(3);
  printf "Total: %f\n", $sw->elapsed();

Will output something like:

  Lap 1: 1.000244
  Lap 2: 2.000375
  Lap 3: 3.000527
  Total: 3.000544



=head1 EXPORTS

Nothing exported by default

=over



=back

=head1 DEPENDENCIES

This module requires these other modules and libraries:

    Time::HiRes

=head1 DESCRIPTION


This module provides convenient methods as expected from a stopwatch.

  start       Starts the stopwatch
  lap         Marks a lap time
  stop        Stops it
  elapsed     Returns the elapsed time
  reset       Stops if running and clears all laps
  is_running  True or False

Similar modules:

C<Time::Stopwatch> - provides a tied interface and will work without 
C<Time::HiRes>.

C<Benchmark::Stopwatch> - is mostly identical, however does not have the 
C<elapsed> method.




=head1 PUBLIC INTERFACE

=head2 new

=over

=item Construct a new Misc::Stopwatch

  new




This example will B<not> abort:


  use Misc::Stopwatch;

This example will return true:


  my $sw = Misc::Stopwatch->new();


=back


=head2 start

=over

=item Reset and Start the stopwatch

  start


Returns C<$self>.

Note that calling this on an already-running instance will reset it.


This example will B<not> abort:


  my $sw = Misc::Stopwatch->new()->start();


=back


=head2 lap

=over

=item Preserve the elapsed time without stopping

  lap



Returns C<$self>.

This is is a no-op unless the stopwatch is running.


This example will B<not> abort:


  my $sw = Misc::Stopwatch->new()->start()->lap();


=back


=head2 stop

=over

=item Stop

  stop


Returns C<$self>.


This example will B<not> abort:


  my $sw = Misc::Stopwatch->new()->start()->stop();


=back


=head2 elapsed

=over

=item Return the elapsed time

  elapsed $lap
  elapsed


In its second form, elapsed will return the time from L</start> to now (or when
L</stop> was called).

C<undefined> is returned when:


1.) C<$lap> is provided but no such lap exists

2.) L</is_running> returns a false value


This example will return true:


  Misc::Stopwatch->new()->start()->elapsed();


=back


=head2 reset

=over

=item Stop and clear data

  reset


Returns C<$self>.


This example will B<not> abort:


  my $sw = Misc::Stopwatch->new()->reset();


=back


=head2 is_running

=over

=item Boolean logic

  is_running


Returns a true value if the stopwatch has been started and has not been 
stopped.


This example will return false:


  Misc::Stopwatch->new()->is_running();

This example will return true:


  Misc::Stopwatch->new()->start()->is_running();


=back


=head1 PACKAGE INTERNALS

=head2 _capture

=over

=item Capture the moment

  _capture





=back



=head1 AUTHORS

Ryan Gies <ryangies@cpan.org>

=head1 COPYRIGHT

Copyright (C) 2006-2010 by Livesite Networks, LLC. All rights reserved.

Copyright (C) 2000-2005 by Ryan Gies. All rights reserved.

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, 
this list of conditions and the following disclaimer.

* The origin of this software must not be misrepresented; you must not 
claim that you wrote the original software. If you use this software in a 
product, an acknowledgment in the product documentation would be 
appreciated but is not required.

* Altered source versions must be plainly marked as such, and must not be 
misrepresented as being the original software.

* The name of the author may not be used to endorse or promote products 
derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED 
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.

To the best of our knowledge, no patented algorithms have been used. However, we
do not have the resources to carry out a patent search, and therefore cannot 
give any guarantee of the above statement.

=cut
