# <@LICENSE>
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to you under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at:
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# </@LICENSE>

package Mail::SpamAssassin::BayesStore::SDBM;

use strict;
use warnings;
use bytes;
use Fcntl;

use Mail::SpamAssassin::BayesStore::DBM;
use Mail::SpamAssassin::Logger;

use vars qw{ @ISA @DBNAMES };

@ISA = qw( Mail::SpamAssassin::BayesStore::DBM );

sub HAS_DBM_MODULE {
  my ($self) = @_;
  if (exists($self->{has_dbm_module})) {
    return $self->{has_dbm_module};
  }
  $self->{has_dbm_module} = eval { require SDBM_File; };
}

sub DBM_MODULE {
  return "SDBM_File";
}

# Possible file extensions used by the kinds of database files SDBM_File
# might create.  We need these so we can create a new file and rename
# it into place.
sub DB_EXTENSIONS {
  return ('.pag', '.dir');
}

sub _unlink_file {
  my ($self, $filename) = @_;

  for my $ext ($self->DB_EXTENSIONS) {
    unlink $filename . $ext;
  }
}

sub _rename_file {
  my ($self, $sourcefilename, $targetfilename) = @_;

  for my $ext ($self->DB_EXTENSIONS) {
    return 0 unless (rename($sourcefilename . $ext, $targetfilename . $ext));
  }
  return 1;
}

# this is called directly from sa-learn(1).
sub perform_upgrade {

  return 1;
}


1;
