File Coverage

blib/lib/Tie/MAB2/Recno.pm

Criterion	Covered	Total	%
statement	8	10	80.0
branch			n/a
condition			n/a
subroutine	4	4	100.0
pod			n/a
total	12	14	85.7

package Tie::MAB2::Recno;

use strict;

BEGIN {
  use Tie::Array;
  our @ISA = qw(Tie::StdArray);
}

use BerkeleyDB qw( DB_RDONLY DB_CREATE DB_FAST_STAT );

warn sprintf "WARNING: Recommended Berkeley DB version is 4.0 or higher. Yours is %s.
    Be prepared for trouble!", $BerkeleyDB::db_version if $BerkeleyDB::db_version<4;

use Fcntl qw( SEEK_SET );
use MAB2::Record::Base;

our $VERSION = sprintf "%d.%03d", q$Revision: 1.6 $ =~ /(\d+)\.(\d+)/;


sub TIEARRAY {
  my($class,%args) = @_;
  my $self = {};
  $self->{ARGS} = \%args;
  die "Could not tie: required argument file missing" unless exists $args{file};
  my $fh;
  unless (open $fh, "<", $args{file}) {
    require Carp;
    Carp::confess("Could not open $args{file}: $!");
  }
  $self->{FH} = $fh;

  my $buf;
  read $fh, $buf, 3;
  seek $fh, 0, SEEK_SET;

  if ($buf eq "###") {
    $self->{RS} = "";
  } else {
    $self->{RS} = "\n";
  }

  # warn sprintf "Filesize: %d\n", -s $fh;
  my @offset;
  # ("BerkeleyDB::Recno", -Filename => "$args{file}.bdbrecno", -Flags => DB_RDONLY, -Mode => 0600);

  my $db = tie(@offset, "BerkeleyDB::Recno", -Filename => "$args{file}.bdbrecno", -Flags => DB_RDONLY, -Mode => 0644);

  #############################################^^^^^^^ did simply not work with RDONLY
  unless ($db) {
    $db = tie(@offset, "BerkeleyDB::Recno", -Filename => "$args{file}.bdbrecno", -Flags => DB_CREATE, -Mode => 0644) or die "Could not tie: $!";
    warn "Creating offset index";
    local($/) = $self->{RS};
    my $Loffset = 0;
    local($|) = 1;
    while (<$fh>) {
      $offset[$. - 1] = $Loffset;
      my $offset = tell $fh;
      printf "." unless int $offset/1000000 == int $Loffset/1000000;
      $Loffset = $offset;
    }
  }
  my $stat = $db->db_stat(DB_FAST_STAT);
  # use Data::Dumper;
  # print Data::Dumper::Dumper($stat);
  $self->{NKEYS} = $stat->{bt_nkeys}; # doesn't seem to improve much, but...

  $self->{OFFSET} = \@offset;
  bless $self, ref $class || $class;
}

sub UNTIE {
  my $self = shift;
  close $self->{FH};
  untie @{$self->{OFFSET}};
}

sub FETCH {
  my($self, $key) = @_;
  my $fh = $self->{FH};
  seek $fh, $self->{OFFSET}[$key], SEEK_SET;
  local($/) = $self->{RS};
  my $rec = <$fh>;
  if ($self->{RS}){ # Band
    chomp $rec;
  } else { # convert Diskette to Band
    $rec =~ s/^### //;
    $rec =~ s/\015?\012//; # the first
    $rec =~ s/\s*\z/\c^\c]/;
    $rec =~ s/\015?\012/\c^/g ;
  }
  my $obj = MAB2::Record::Base->new($rec,$key);
  $obj;
}

sub FETCHSIZE {
  my($self) = @_;
  $self->{NKEYS};
}

sub EXISTS {
  my($self,$key) = @_;
  $key >= 0 && $key <= $self->{NKEYS};
}

for my $method (qw(STORE DELETE CLEAR)) {
  no strict "refs";
  *$method = sub {
    warn "$method not supported on ".ref shift;
    return;
  };
}

#sub EXISTS {
#  my($self, $key) = @_;
#  exists $self->{OFFSET}[$key];
#}

1;

__END__