#!/usr/bin/perl -w
# This file was preprocessed, do not edit!


package Debconf::DbDriver::File;
use strict;
use Debconf::Log qw(:all);
use Cwd 'abs_path';
use POSIX ();
use Fcntl qw(:DEFAULT :flock);
use IO::Handle;
use base 'Debconf::DbDriver::Cache';


use fields qw(filename mode format _fh);


sub init {
my $this=shift;

if (exists $this->{mode}) {
$this->{mode} = oct($this->{mode});
}
else {
$this->{mode} = 0600;
}
$this->{format} = "822" unless exists $this->{format};
$this->{backup} = 1 unless exists $this->{backup};

$this->error("No format specified") unless $this->{format};
eval "use Debconf::Format::$this->{format}";
if ($@) {
$this->error("Error setting up format object $this->{format}: $@");
}
$this->{format}="Debconf::Format::$this->{format}"->new;
if (not ref $this->{format}) {
$this->error("Unable to make format object");
}

$this->error("No filename specified") unless $this->{filename};

my ($directory)=$this->{filename}=~m!^(.*)/[^/]+!;
if (! -d $directory) {
mkdir $directory || $this->error("mkdir $directory:$!");
}

$this->{filename} = abs_path($this->{filename});

debug "db $this->{name}" => "started; filename is $this->{filename}";

if (! -e $this->{filename}) {
$this->{backup}=0;
sysopen(my $fh, $this->{filename},
O_WRONLY|O_TRUNC|O_CREAT,$this->{mode}) or
$this->error("could not open $this->{filename}");
close $fh;
}

my $implicit_readonly=0;
if (! $this->{readonly}) {
if (open ($this->{_fh}, "+<", $this->{filename})) {
while (! flock($this->{_fh}, LOCK_EX | LOCK_NB)) {
next if $! == &POSIX::EINTR;
$this->error("$this->{filename} is locked by another process: $!");
last;
}
}
else {
$implicit_readonly=1;
}
}
if ($this->{readonly} || $implicit_readonly) {
if (! open ($this->{_fh}, "<", $this->{filename})) {
$this->error("could not open $this->{filename}: $!");
return; # always abort, even if not throwing fatal error
}
}

$this->SUPER::init(@_);

debug "db $this->{name}" => "loading database";

while (! eof $this->{_fh}) {
my ($item, $cache)=$this->{format}->read($this->{_fh});
$this->{cache}->{$item}=$cache;
}
if ($this->{readonly} || $implicit_readonly) {
close $this->{_fh};
}
}


sub shutdown {
my $this=shift;

return if $this->{readonly};

if (grep $this->{dirty}->{$_}, keys %{$this->{cache}}) {
debug "db $this->{name}" => "saving database";
}
else {
debug "db $this->{name}" => "no database changes, not saving";

delete $this->{_fh};

return 1;
}

sysopen(my $fh, $this->{filename}."-new",
O_WRONLY|O_TRUNC|O_CREAT,$this->{mode}) or
$this->error("could not write $this->{filename}-new: $!");
while (! flock($fh, LOCK_EX | LOCK_NB)) {
next if $! == &POSIX::EINTR;
$this->error("$this->{filename}-new is locked by another process: $!");
last;
}
$this->{format}->beginfile;
foreach my $item (sort keys %{$this->{cache}}) {
next unless defined $this->{cache}->{$item}; # skip deleted
$this->{format}->write($fh, $this->{cache}->{$item}, $item)
or $this->error("could not write $this->{filename}-new: $!");
}
$this->{format}->endfile;

$fh->flush or $this->error("could not flush $this->{filename}-new: $!");
$fh->sync or $this->error("could not sync $this->{filename}-new: $!");

if (-e $this->{filename} && $this->{backup}) {
rename($this->{filename}, $this->{filename}."-old") or
debug "db $this->{name}" => "rename failed: $!";
}
rename($this->{filename}."-new", $this->{filename}) or
$this->error("rename failed: $!");

delete $this->{_fh};

return 1;
}


sub load {
return undef;
}


1