--- trunk/IsisDB.pm	2005/01/05 21:23:04	33
+++ trunk/lib/Biblio/Isis.pm	2005/03/12 21:05:29	41
@@ -1,4 +1,4 @@
-package IsisDB;
+package Biblio::Isis;
 use strict;
 
 use Carp;
@@ -9,7 +9,7 @@
 BEGIN {
 	use Exporter ();
 	use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-	$VERSION     = 0.09;
+	$VERSION     = 0.13;
 	@ISA         = qw (Exporter);
 	#Give a hoot don't pollute, do not export more than needed by default
 	@EXPORT      = qw ();
@@ -20,13 +20,13 @@
 
 =head1 NAME
 
-IsisDB - Read CDS/ISIS, WinISIS and IsisMarc database
+Biblio::Isis - Read CDS/ISIS, WinISIS and IsisMarc database
 
 =head1 SYNOPSIS
 
-  use IsisDB;
+  use Biblio::Isis;
 
-  my $isis = new IsisDB(
+  my $isis = new Biblio::Isis(
   	isisdb => './cds/cds',
   );
 
@@ -81,7 +81,7 @@
 
 Open ISIS database
 
- my $isis = new IsisDB(
+ my $isis = new Biblio::Isis(
  	isisdb => './cds/cds',
 	read_fdt => 1,
 	include_deleted => 1,
@@ -147,7 +147,10 @@
 	push @must_exist, "fdt" if ($self->{read_fdt});
 
 	foreach my $ext (@must_exist) {
-		croak "missing ",uc($ext)," file in ",$self->{isisdb} unless ($self->{$ext."_file"});
+		unless ($self->{$ext."_file"}) {
+			carp "missing ",uc($ext)," file in ",$self->{isisdb};
+			return;
+		}
 	}
 
 	print STDERR "## using files: ",join(" ",@isis_files),"\n" if ($self->{debug});
@@ -192,12 +195,12 @@
 	# NXTMFB*	last block allocated to master file
 	# NXTMFP	offset to next available position in last block
 	# MFTYPE	always 0 for user db file (1 for system)
-	seek($self->{'fileMST'},4,0) || carp "can't seek to offset 0 in MST: $!";
+	seek($self->{'fileMST'},4,0) || croak "can't seek to offset 0 in MST: $!";
 
 	my $buff;
 
-	read($self->{'fileMST'}, $buff, 4) || carp "can't read NXTMFN from MST: $!";
-	$self->{'NXTMFN'}=unpack("V",$buff) || carp "NXTNFN is zero";
+	read($self->{'fileMST'}, $buff, 4) || croak "can't read NXTMFN from MST: $!";
+	$self->{'NXTMFN'}=unpack("V",$buff) || croak "NXTNFN is zero";
 
 	print STDERR Dumper($self),"\n" if ($self->{debug});
 
@@ -221,80 +224,6 @@
 	return $self->{'NXTMFN'} - 1;
 }
 
-=head2 read_cnt
-
-Read content of C<.CNT> file and return hash containing it.
-
-  print Dumper($isis->read_cnt);
-
-This function is not used by module (C<.CNT> files are not required for this
-module to work), but it can be useful to examine your index (while debugging
-for example).
-
-=cut
-
-sub read_cnt  {
-	my $self = shift;
-
-	croak "missing CNT file in ",$self->{isisdb} unless ($self->{cnt_file});
-
-	# Get the index information from $db.CNT
-   
-	open(my $fileCNT, $self->{cnt_file}) || carp "can't read '$self->{cnt_file}': $!";
-	binmode($fileCNT);
-
-	my $buff;
-
-	read($fileCNT, $buff, 26) || carp "can't read first table from CNT: $!";
-	$self->unpack_cnt($buff);
-
-	read($fileCNT, $buff, 26) || carp "can't read second table from CNT: $!";
-	$self->unpack_cnt($buff);
-
-	close($fileCNT);
-
-	return $self->{cnt};
-}
-
-=head2 unpack_cnt
-
-Unpack one of two 26 bytes fixed length record in C<.CNT> file.
-
-Here is definition of record:
-
- off key	description				size
-  0: IDTYPE	BTree type				s
-  2: ORDN	Nodes Order				s
-  4: ORDF	Leafs Order				s
-  6: N		Number of Memory buffers for nodes	s
-  8: K		Number of buffers for first level index	s
- 10: LIV	Current number of Index Levels		s
- 12: POSRX	Pointer to Root Record in N0x		l
- 16: NMAXPOS	Next Available position in N0x		l
- 20: FMAXPOS	Next available position in L0x		l
- 24: ABNORMAL	Formal BTree normality indicator	s
- length: 26 bytes
-
-This will fill C<$self> object under C<cnt> with hash. It's used by C<read_cnt>.
-
-=cut
-
-sub unpack_cnt {
-	my $self = shift;
-
-	my @flds = qw(ORDN ORDF N K LIV POSRX NMAXPOS FMAXPOS ABNORMAL);
-
-	my $buff = shift || return;
-	my @arr = unpack("vvvvvvVVVv", $buff);
-
-	print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
-
-	my $IDTYPE = shift @arr;
-	foreach (@flds) {
-		$self->{cnt}->{$IDTYPE}->{$_} = abs(shift @arr);
-	}
-}
-
 =head2 fetch
 
 Read record with selected MFN
@@ -335,7 +264,15 @@
 
 	# read XRFMFB abd XRFMFP
 	read($self->{'fileXRF'}, $buff, 4);
-	my $pointer=unpack("V",$buff) || carp "pointer is null";
+	my $pointer=unpack("V",$buff);
+	if (! $pointer) {
+		if ($self->{include_deleted}) {
+			return;
+		} else {
+			warn "pointer for MFN $mfn is null\n";
+			return;
+		}
+	}
 
 	# check for logically deleted record
 	if ($pointer & 0x80000000) {
@@ -464,7 +401,7 @@
 
 	my $mfn = shift || croak "need MFN";
 
-	my $rec = $self->fetch($mfn);
+	my $rec = $self->fetch($mfn) || return;
 
 	my $out = "0\t$mfn";
 
@@ -532,7 +469,7 @@
 	# init record to include MFN as field 000
 	my $rec = { '000' => [ $mfn ] };
 
-	my $row = $self->fetch($mfn);
+	my $row = $self->fetch($mfn) || return;
 
 	foreach my $k (keys %{$row}) {
 		foreach my $l (@{$row->{$k}}) {
@@ -576,6 +513,81 @@
 	return $self->{'TagName'}->{$tag} || $tag;
 }
 
+
+=head2 read_cnt
+
+Read content of C<.CNT> file and return hash containing it.
+
+  print Dumper($isis->read_cnt);
+
+This function is not used by module (C<.CNT> files are not required for this
+module to work), but it can be useful to examine your index (while debugging
+for example).
+
+=cut
+
+sub read_cnt  {
+	my $self = shift;
+
+	croak "missing CNT file in ",$self->{isisdb} unless ($self->{cnt_file});
+
+	# Get the index information from $db.CNT
+   
+	open(my $fileCNT, $self->{cnt_file}) || croak "can't read '$self->{cnt_file}': $!";
+	binmode($fileCNT);
+
+	my $buff;
+
+	read($fileCNT, $buff, 26) || croak "can't read first table from CNT: $!";
+	$self->unpack_cnt($buff);
+
+	read($fileCNT, $buff, 26) || croak "can't read second table from CNT: $!";
+	$self->unpack_cnt($buff);
+
+	close($fileCNT);
+
+	return $self->{cnt};
+}
+
+=head2 unpack_cnt
+
+Unpack one of two 26 bytes fixed length record in C<.CNT> file.
+
+Here is definition of record:
+
+ off key	description				size
+  0: IDTYPE	BTree type				s
+  2: ORDN	Nodes Order				s
+  4: ORDF	Leafs Order				s
+  6: N		Number of Memory buffers for nodes	s
+  8: K		Number of buffers for first level index	s
+ 10: LIV	Current number of Index Levels		s
+ 12: POSRX	Pointer to Root Record in N0x		l
+ 16: NMAXPOS	Next Available position in N0x		l
+ 20: FMAXPOS	Next available position in L0x		l
+ 24: ABNORMAL	Formal BTree normality indicator	s
+ length: 26 bytes
+
+This will fill C<$self> object under C<cnt> with hash. It's used by C<read_cnt>.
+
+=cut
+
+sub unpack_cnt {
+	my $self = shift;
+
+	my @flds = qw(ORDN ORDF N K LIV POSRX NMAXPOS FMAXPOS ABNORMAL);
+
+	my $buff = shift || return;
+	my @arr = unpack("vvvvvvVVVv", $buff);
+
+	print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
+
+	my $IDTYPE = shift @arr;
+	foreach (@flds) {
+		$self->{cnt}->{$IDTYPE}->{$_} = abs(shift @arr);
+	}
+}
+
 1;
 
 =head1 BUGS