mmap_server.pl

#!/usr/bin/perl
use 5.16.1;
use strict;
use warnings;
use constant {
    DFLT_SER_TAG        => 'CB',
    N_PERC_RED          =>  15,
};
use subs qw(store_data);

use File::Slurp qw(write_file);
use File::Map qw(map_file);
use AnyEvent;
use Try::Tiny;
use Tag::DeCoder;

my %hsh=map {'t'.$_ => {'triggerid'=>$_, 'status'=>(int(rand 25) & 1), 'lostfunk'=>rand(),'svc-path'=>[map [map int(rand 10000), 2..(int(rand 5)+2)], 0..int(rand 5)]}} 1..10000;

my $pthMapFile='/tmp/test.mmap.'.$$;

# Initialy write data to the file that will be mmap'ed later
store_data($pthMapFile, \%hsh);

# Save mmaped file name
write_file '/tmp/mmaped_file.pth', $pthMapFile;
say "Mapping to: $pthMapFile";

# Actually create mapping from file to $strMap string variable
map_file my $strMap, $pthMapFile, '+<';

my $cv=AnyEvent->condvar;
my $aeh=AnyEvent->timer('after'=>0, 'interval'=>1, 'cb' => sub {
# Doi it immediately and repeat every 1 sec...
    try {
        say scalar(localtime);
        @{$hsh{'t'.(int(rand 10000)+1)}}{qw/lostfunk status/} = (rand(), int(rand 25) & 1) for 7..int(rand 28)+7;
        store_data(\$strMap, \%hsh);
    } catch {
        say "ERROR: $_";
    }
});
$cv->recv;

sub store_data ($$$) {
    my $where2store = $_[0];
    my $sData = encodeByTag($_[2] // DFLT_SER_TAG() => $_[1]);
    use bytes;
    unless (ref $where2store) {
        open my $fh, '>', $where2store;
        print $fh pack('V', length $sData), $sData, "\x00" x int(length($sData)*N_PERC_RED*0.01);
        close $fh;
    } else {
        substr(${$where2store}, 0, length($sData)+4) = pack('V', length $sData) . $sData
    }
    no bytes;
}