use strict;

use Time::HiRes qw(time);

my @data=();

my @names=qw(albert arthur bernard bill charlie david jack jonh joseph mark michael peter steven);
my @surnames=qw(bell brown canfield cornwell devlin doyle golden hoffman maclean powell rowling tovard twain warlick);
my @places=qw(amsterdan athens belfast berlin bern brussels copenhagen helsinki lisbon london luxenbourg madrid oslo paris rome stockholm vaduz vienna);

for (my $i=0;$i<=1000000;$i++) {
        my $name=$names[int(rand()*$#names)];
        my $surname=$surnames[int(rand()*$#surnames)];
        my $place=$places[int(rand()*$#places)];
        my $age=int(rand()*50)+25;
        my $rec={name=>$name,surname=>$surname,place=>$place,age=>$age};
        push @data, $rec;
}


##</code><code>##


my @Fields=(
        { key   => 'age', content=>35 },
        {       key     => 'place', content=>'london'},
);

my @Persons=@data;
my @Person2=@data;

print "Persons: $#Persons\nPerson2: $#Person2\n\n";

my $field;
my $person;
my $i=0;


##</code><code>##


my $ta=time();
foreach $field (@Fields) { # <- age and surname in this case
   scalar(@Persons)==0 && last;
   for ($i=0;$i<scalar(@Persons);$i++) {
       ($Persons[$i]->{$field->{key}} eq $field->{content}) && next;

        splice(@Persons,$i,1);
        $i--;
   }
}

my $tb=time();


##</code><code>##


my $use=1;
my @Rset=();

foreach $person (@Person2) {
        $use=1;
        foreach $field (@Fields) {
                if ($person->{$field->{key}} ne $field->{content}) {
                        $use=0;
                        last;
                }
        }
        if ($use) {
                push @Rset, $person;
        }
}
my $tc=time;


##</code><code>##


my $iab=$tb-$ta;
my $ibc=$tc-$tb;
print "TIMES:\nab: $iab\nbc: $ibc\n";
print "COUNTS:\nab: ", $#Persons,"\nbc: ",$#Rset,"\n";


##</code><code>##


mpneves@voyager perl$ ./test.pl
Persons: 1000000
Person2: 1000000

TIMES:
ab: 17.5640239715576
bc: 1.96199607849121
COUNTS:
ab: 1153
bc: 1153
mpneves@voyager perl$ ./test.pl
Persons: 1000000
Person2: 1000000

TIMES:
ab: 18.5665609836578
bc: 1.95595502853394
COUNTS:
ab: 1185
bc: 1185
mpneves@voyager perl$ ./test.pl
Persons: 1000000
Person2: 1000000

TIMES:
ab: 24.4221110343933
bc: 3.58428502082825
COUNTS:
ab: 1213
bc: 1213