package Data::Throttler_CHI;

use strict;
use warnings;

sub new {
    my ($package, %args) = @_;
    bless \%args, $package;
}

my $counter = 0;
sub try_push {
    my $self = shift;
    my $now = time();
    $counter++;
    $counter = 0 if $counter == 2e31; # wraparound 32bit int
    $self->{cache}->set("$now|$counter", 1, $self->{interval}); # Y2286!
    my @keys0 = $self->{cache}->get_keys;

    my @keys;
    for my $key (@keys0) {
        my ($key_time, $key_serial) = split /\|/, $key, 2;
        if ($key_time >= $now - $self->{interval}) {
            push @keys, $key;
        }
    }

    # these drivers return expired keys: Memory. so we need to purge these keys
    my $do_purge = rand() < 0.05; # probabilistic
    $self->{cache}->purge if $do_purge && @keys < @keys0;

    return @keys <= $self->{max_items} ? 1:0;
}

1;