--- trunk/IsisDB.pm	2004/12/29 15:17:59	8
+++ trunk/IsisDB.pm	2004/12/29 17:03:52	11
@@ -7,7 +7,7 @@
 BEGIN {
 	use Exporter ();
 	use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-	$VERSION     = 0.02;
+	$VERSION     = 0.03;
 	@ISA         = qw (Exporter);
 	#Give a hoot don't pollute, do not export more than needed by default
 	@EXPORT      = qw ();
@@ -22,16 +22,29 @@
 
 =head1 SYNOPSIS
 
-  use IsisDB
+  use IsisDB;
+
   my $isis = new IsisDB(
   	isisdb => './cds/cds',
   );
 
+  for(my $mfn = 1; $mfn <= $isis->{'maxmfn'}; $mfn++) {
+	print $isis->to_ascii($mfn),"\n";
+  }
+
 =head1 DESCRIPTION
 
 This module will read CDS/ISIS databases and create hash values out of it.
 It can be used as perl-only alternative to OpenIsis module.
 
+This will module will always be slower that OpenIsis module which use C
+library. However, since it's written in perl, it's platform independent (so
+you don't need C compiler), and can be easily modified.
+
+Unique feature of this module is ability to C<include_deleted> records.
+It will also skip zero sized fields (OpenIsis has a bug in XS bindings, so
+fields which are zero sized will be filled with random junk from memory).
+
 =head1 METHODS
 
 =cut
@@ -50,14 +63,6 @@
 # some binary reads
 #
 
-sub Read32 {
-	my $self = shift;
-
-	my $f = shift || die "Read32 needs file handle";
-	read($$f,$b,4) || die "can't read 4 bytes from $$f from position ".tell($f);
-	return unpack("l",$b);
-}
-
 =head2 new
 
 Open CDS/ISIS database
@@ -66,6 +71,7 @@
  	isisdb => './cds/cds',
 	read_fdt => 1,
 	debug => 1,
+	include_deleted => 1,
  );
 
 Options are described below:
@@ -86,6 +92,10 @@
 
 Dump a C<lot> of debugging output.
 
+=item include_deleted
+
+Don't skip logically deleted records in ISIS.
+
 =back
 
 It will also set C<$isis-E<gt>{'maxmfn'}> which is maximum MFN stored in database.
@@ -97,9 +107,11 @@
 	my $self = {};
 	bless($self, $class);
 
-	$self->{isisdb} = {@_}->{isisdb} || croak "new needs database name as argument!";
+	croak "new needs database name (isisdb) as argument!" unless ({@_}->{isisdb});
 
-	$self->{debug} = {@_}->{debug};
+	foreach my $v (qw{isisdb debug include_deleted}) {
+		$self->{$v} = {@_}->{$v};
+	}
 
 	# if you want to read .FDT file use read_fdt argument when creating class!
 	if ({@_}->{read_fdt} && -e $self->{isisdb}.".FDT") {
@@ -140,7 +152,11 @@
 	# NXTMFP	offset to next available position in last block
 	# MFTYPE	always 0 for user db file (1 for system)
 	seek(fileMST,4,0);
-	$self->{'NXTMFN'}=$self->Read32(\*fileMST) || carp "NXTNFN is zero";
+
+	my $buff;
+
+	read(fileMST, $buff, 4);
+	$self->{'NXTMFN'}=unpack("l",$buff) || carp "NXTNFN is zero";
 
 	# save maximum MFN
 	$self->{'maxmfn'} = $self->{'NXTMFN'} - 1;
@@ -173,13 +189,14 @@
 		my $buff = shift || return;
 		my @arr = unpack("ssssssllls", $buff);
 
+		print "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
+
 		my $IDTYPE = shift @arr;
 		foreach (@flds) {
 			$self->{$IDTYPE}->{$_} = abs(shift @arr);
 		}
 	}
 
-	my $buff;
 	read(fileCNT, $buff, 26);
 	$self->unpack_cnt($buff);
 
@@ -223,8 +240,11 @@
 	print "seeking to $mfnpos in file '$self->{isisdb}.XRF'\n" if ($self->{debug});
 	seek($self->{'fileXRF'},$mfnpos,0);
 
+	my $buff;
+
 	# read XRFMFB abd XRFMFP
-	my $pointer=$self->Read32(\*{$self->{'fileXRF'}});
+	read($self->{'fileXRF'}, $buff, 4);
+	my $pointer=unpack("l",$buff) || carp "pointer is null";
 
 	my $XRFMFB = int($pointer/2048);
 	my $XRFMFP = $pointer - ($XRFMFB*2048);
@@ -249,7 +269,8 @@
 
 	seek($self->{'fileMST'},$offset4,0);
 
-	my $value=$self->Read32(\*{$self->{'fileMST'}});
+	read($self->{'fileMST'}, $buff, 4);
+	my $value=unpack("l",$buff);
 
 	if ($value!=$mfn) {
 print ("Error: The MFN:".$mfn." is not found in MST(".$value.")");    
@@ -263,13 +284,20 @@
 #	$NVF=$self->Read16($fileMST);
 #	$STATUS=$self->Read16($fileMST);
 
-	my $buff;
 	read($self->{'fileMST'}, $buff, 14);
 
 	my ($MFRL,$MFBWB,$MFBWP,$BASE,$NVF,$STATUS) = unpack("slssss", $buff);
 
 	print "MFRL: $MFRL MFBWB: $MFBWB MFBWP: $MFBWP BASE: $BASE NVF: $NVF STATUS: $STATUS\n" if ($self->{debug});
 
+	# delete old record
+	delete $self->{record};
+
+	if (! $self->{'include_deleted'} && $MFRL < 0) {
+		print "## logically deleted record $mfn, skipping...\n" if ($self->{debug});
+		return;
+	}
+
 	# Get Directory Format
 
 	my @FieldPOS;
@@ -309,20 +337,16 @@
 
 	# Get Variable Fields
 
-	delete $self->{record};
-
 	read($self->{'fileMST'},$buff,$fld_len);
 
 	for (my $i = 0 ; $i < $NVF ; $i++) {
+		# skip zero-sized fields
+		next if ($FieldLEN[$i] == 0);
+
 		push @{$self->{record}->{$FieldTAG[$i]}}, substr($buff,$FieldPOS[$i],$FieldLEN[$i]);
 	}
 	close(fileMST);
 
-	# The record is marked for deletion
-	if ($STATUS==1) {
-		return -1;
-	}
-
 	print Dumper($self) if ($self->{debug});
 
 	return $self->{'record'};