File Coverage

lib/Ubic/AtomicFile.pm

Criterion	Covered	Total	%
statement	23	23	100.0
branch	7	14	50.0
condition			n/a
subroutine	5	5	100.0
pod	1	1	100.0
total	36	43	83.7

package Ubic::AtomicFile;
$Ubic::AtomicFile::VERSION = '1.58_01'; # TRIAL
use strict;
use warnings;

# ABSTRACT: atomic file operations


use IO::Handle;
use Params::Validate qw(:all);

sub store($$;$) {
    my ($data, $file, @options) = @_;

    my $options = validate(@options, {
        sync => { default => 1 },
    });

    my $new_file = "$file.new";

    open my $fh, '>', $new_file or die "Can't open '$new_file' for writing: $!";
    print {$fh} $data or die "Can't print to '$new_file': $!";
    $fh->flush or die "Can't flush '$new_file': $!";

    if ($options->{sync}) {
        # Here is a link which says why we should do sync too if we don't want to lose data:
        # https://bugs.launchpad.net/ubuntu/+source/linux/+bug/317781/comments/54
        #
        # For some types of atomic files this is important, for others (pidfiles, temp files) it can be too big performance hit.
        # Every part of ubic code decides for itself.
        $fh->sync or die "Can't sync '$new_file': $!";
    }

    close $fh or die "Can't close '$new_file': $!";
    rename $new_file => $file or die "Can't rename '$new_file' to '$file': $!";
}

1;

__END__