use strict;
use warnings;

use Benchmark q{cmpthese};

my $inFile = q{/work/johngg/spw593475.dat};
open my $inFH, q{<}, $inFile
   or die qq{open: $inFile: $!\n};

my $startPos = tell $inFH;

my $rcArray = sub
   {
       seek $inFH, $startPos, 0;
       my @lines = <$inFH>;
       chomp @lines;
       my %dataHash = ();
       foreach (@lines)
       {
           my ($key, $value) = split m{\|}, $_, 2;
           $dataHash{$key} = $value;
       }
       return \%dataHash;
   };

my $rcByLine = sub
   {
       seek $inFH, $startPos, 0;
       my %dataHash = ();
       while (<$inFH>)
       {
           chomp;
           my ($key, $value) = split m{\|}, $_, 2;
           $dataHash{$key} = $value;
       }
       return \%dataHash;
   };

my $rcMap = sub
   {
       seek $inFH, $startPos, 0;
       my %dataHash = 
          map {chomp; split m{\|}, $_, 2}
          <$inFH>;
       return \%dataHash;
   };

cmpthese (10,
   {
      Array  => $rcArray,
      ByLine => $rcByLine,
      Map    => $rcMap,
   });

close $inFH
   or die qq{close: $inFile: $!\n};

##</code><code>##

$ spw593475
       s/iter  Array ByLine    Map
Array    1.30     --   -14%   -15%
ByLine   1.12    16%     --    -1%
Map      1.10    18%     1%     --
$ spw593475
       s/iter  Array    Map ByLine
Array    1.43     --   -14%   -18%
Map      1.22    17%     --    -5%
ByLine   1.16    23%     5%     --
$ spw593475
       s/iter  Array ByLine    Map
Array    1.31     --   -14%   -15%
ByLine   1.12    17%     --    -0%
Map      1.12    17%     0%     --
$ spw593475
       s/iter  Array ByLine    Map
Array    1.31     --   -13%   -15%
ByLine   1.13    16%     --    -1%
Map      1.11    17%     1%     --
$ spw593475
       s/iter  Array ByLine    Map
Array    1.30     --   -14%   -16%
ByLine   1.12    16%     --    -3%
Map      1.09    19%     3%     --
$