package Spline::Netstring;

use strict;
use warnings;

our @EXPORT = qw(
    netstring_read
    netstring_write
);

sub read_length($) {
    my $fd = shift;
    my $length;

    local $/ = ':';
    $length = <$fd>;
    die "Cannot read netstring length" unless defined($length);
    chomp $length;

    return $length;
}

sub netstring_read($) {
    my $fd = shift;
    my ($length, $data);

    $length = read_length($fd);
    if (read($fd, $data, $length) == $length) {
        (getc() eq ',') or die "Closing , missing";
    }
    else {
        die 'Received only ' . length($data) . " of $length bytes";
    }

    return $data;
}

sub netstring_write($$) {
    my ($fd, $data) = @_;

    print $fd length($data).':'.$data.',';
}