redis sdiff example.

redis-sdiff.pl

#!/usr/bin/env perl
use strict;
use warnings;
use utf8;

use Redis;

srand(time ^ ($$ + ($$ << 15)));
my $max_rand = 100000000000;
my $keybase = 'HOGE::';
my $master_set_key = 'HOGE::MASTER';
my $redis = Redis->new;
my $result = $redis->select(1);

sub rand_items {
    my ($max_item) = @_;

    my @items = ();
    my %item_map = ();
    my $count = 0;
    while ( $count < $max_item ) {
        my $r = "ITEM_" . int(rand($max_rand));
        next if $item_map{$r};

        $item_map{$r} = 1;
        push @items, $r;
        $count++;
    }

    return @items;
}

sub rand_selected_items {
    my ($items, $max_selected_items) = @_;

    my @selected_items = ();
    my %selected_map = ();
    my $count = 0;
    while ( $count < $max_selected_items ) {
        my $k = int(rand(@$items));
        next if $selected_map{$k};

        $selected_map{$k} = 1;
        push @selected_items, "${keybase}ITEM::" . $items->[$k];
        $count++;
    }

    return @selected_items;
}

sub create_set {
    my ($items) = @_;
    foreach my $item ( @$items ) {
        $redis->sadd($master_set_key, $item);
        $redis->sadd("${keybase}ITEM::$item", $item);
    }
}

my ( $max_item, $max_selected_items ) = @ARGV;
### $max_item
### $max_selected_items

my @items = rand_items($max_item);
### @items

my @selected_items = rand_selected_items(\@items, $max_selected_items);
### @selected_items

$redis->flushdb;
create_set(\@items);

my @diff_items = $redis->sdiff($master_set_key, @selected_items);
### @diff_items

# 
# perl -MSmart::Comments ./redis-sdiff.pl 10000 9990
#