use strict ;
use warnings ;
use Data::Dumper ;

my $VAR1 = {
          'data' => {
                      'dir1' => {
								  'fileA' => {
											  'pid' => {
														 '61781' => 1
													   },
											  'total' => 13
											},
								  'fileB' => {
											 'pid' => {
														'61799' => 1
													  },
											 'total' => 12
										   }
							},
                      'dir2' => {
								  'fileC' => {
											  'pid' => {
														 '12345' => 1
													   },
											  'total' => 10
											},
								  'fileA' => {
											 'pid' => {
														'61439' => 1
													  },
											 'total' => 5
										   }
							}
                    },
          'total' => {
                       'fileA' => 18,
                       'fileB' => 12,
                       'fileC' => 10,
                     }
        };
		
		
my $VAR2 = {
          'data' => {
                      'dir3' => {
								  'fileA' => {
											  'pid' => {
														 '616161' => 1
													   },
											  'total' => 6
											},
								  'fileD' => {
											 'pid' => {
														'54321' => 1
													  },
											 'total' => 12
										   }
							},
                      'dir4' => {
								  'fileE' => {
											  'pid' => {
														 '15151' => 1
													   },
											  'total' => 3
											},
								  'fileA' => {
											 'pid' => {
														'1718' => 1
													  },
											 'total' => 2
										   }
							}
                    },
          'total' => {
                       'fileA' => 8,
                       'fileD' => 12,
                       'fileE' => 3,
                     }
        };
		
foreach ( grep !exists $VAR1->{ data }->{ $_ }, keys %{$VAR2->{ data }} ) {
	$VAR1->{ data }->{ $_ } = $VAR2->{ data }->{ $_ } ;
	foreach my $f ( keys %{$VAR2->{ data }->{ $_ }} ) {
		$VAR1->{ total }->{ $f } += $VAR2->{ data }->{ $_ }->{ $f }->{ total } ;
	}
}

print Dumper( $VAR1 ) ;