--- trunk/IsisDB.pm	2004/12/29 22:46:40	15
+++ trunk/IsisDB.pm	2004/12/30 17:16:34	16
@@ -7,7 +7,7 @@
 BEGIN {
 	use Exporter ();
 	use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-	$VERSION     = 0.05;
+	$VERSION     = 0.06;
 	@ISA         = qw (Exporter);
 	#Give a hoot don't pollute, do not export more than needed by default
 	@EXPORT      = qw ();
@@ -210,7 +210,7 @@
 		my $buff = shift || return;
 		my @arr = unpack("ssssssllls", $buff);
 
-		print "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
+		print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
 
 		my $IDTYPE = shift @arr;
 		foreach (@flds) {
@@ -227,7 +227,7 @@
 
 	close(fileCNT);
 
-	print Dumper($self),"\n" if ($self->{debug});
+	print STDERR Dumper($self),"\n" if ($self->{debug});
 
 	# open files for later
 	open($self->{'fileXRF'}, $self->{isisdb}.".XRF") || croak "can't open '$self->{isisdb}.XRF': $!";
@@ -258,12 +258,16 @@
 
 	my $mfn = shift || croak "fetch needs MFN as argument!";
 
-	print "fetch: $mfn\n" if ($self->{debug});
+	# is mfn allready in memory?
+	my $old_mfn = $self->{'current_mfn'} || -1;
+	return if ($mfn == $old_mfn);
+
+	print STDERR "## fetch: $mfn\n" if ($self->{debug});
 
 	# XXX check this?
 	my $mfnpos=($mfn+int(($mfn-1)/127))*4;
 
-	print "seeking to $mfnpos in file '$self->{isisdb}.XRF'\n" if ($self->{debug});
+	print STDERR "## seeking to $mfnpos in file '$self->{isisdb}.XRF'\n" if ($self->{debug});
 	seek($self->{'fileXRF'},$mfnpos,0);
 
 	my $buff;
@@ -275,32 +279,26 @@
 	my $XRFMFB = int($pointer/2048);
 	my $XRFMFP = $pointer - ($XRFMFB*2048);
 
-	print "XRFMFB: $XRFMFB XRFMFP: $XRFMFP\n" if ($self->{debug});
 
-	# XXX fix this to be more readable!!
-	# e.g. (XRFMFB - 1) * 512 + XRFMFP
+	# (XRFMFB - 1) * 512 + XRFMFP
+	# why do i have to do XRFMFP % 1024 ?
 
-	my $offset = $pointer;
-	my $offset2=int($offset/2048)-1;
-	my $offset22=int($offset/4096);
-	my $offset3=$offset-($offset22*4096);
-	if ($offset3>512) {
-		$offset3=$offset3-2048;
-	}
-	my $offset4=($offset2*512)+$offset3;
+	my $blk_off = (($XRFMFB - 1) * 512) + ($XRFMFP % 1024);
 
-	print "$offset - $offset2 - $offset3 - $offset4\n" if ($self->{debug});
+	print STDERR "## pointer: $pointer XRFMFB: $XRFMFB XRFMFP: $XRFMFP offset: $blk_off\n" if ($self->{'debug'});
 
 	# Get Record Information
 
-	seek($self->{'fileMST'},$offset4,0);
+	seek($self->{'fileMST'},$blk_off,0);
 
 	read($self->{'fileMST'}, $buff, 4);
 	my $value=unpack("l",$buff);
 
+	print STDERR "## offset for rowid $value is $blk_off (blk $XRFMFB off $XRFMFP)\n" if ($self->{debug});
+
 	if ($value!=$mfn) {
-print ("Error: The MFN:".$mfn." is not found in MST(".$value.")");    
-		return -1;	# XXX deleted record?
+		carp "Error: MFN ".$mfn." not found in MST(".$value.")";    
+		#return;		# XXX deleted record?
 	}
 
 #	$MFRL=$self->Read16($fileMST);
@@ -314,16 +312,19 @@
 
 	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});
+	print STDERR "## MFRL: $MFRL MFBWB: $MFBWB MFBWP: $MFBWP BASE: $BASE NVF: $NVF STATUS: $STATUS\n" if ($self->{debug});
 
 	# delete old record
 	delete $self->{record};
 
+	## FIXME this is a bug
 	if (! $self->{'include_deleted'} && $MFRL < 0) {
 		print "## logically deleted record $mfn, skipping...\n" if ($self->{debug});
 		return;
 	}
 
+	warn "BASE is not 18+6*NVF" unless ($BASE == 18 + 6 * $NVF);
+
 	# Get Directory Format
 
 	my @FieldPOS;
@@ -332,7 +333,7 @@
 
 	read($self->{'fileMST'}, $buff, 6 * $NVF);
 
-	my $fld_len = 0;
+	my $rec_len = 0;
 
 	for (my $i = 0 ; $i < $NVF ; $i++) {
 
@@ -342,7 +343,7 @@
 
 		my ($TAG,$POS,$LEN) = unpack("sss", substr($buff,$i * 6, 6));
 
-		print "TAG: $TAG POS: $POS LEN: $LEN\n" if ($self->{debug});
+		print STDERR "## TAG: $TAG POS: $POS LEN: $LEN\n" if ($self->{debug});
 
 		# The TAG does not exists in .FDT so we set it to 0.
 		#
@@ -358,12 +359,14 @@
 		push @FieldPOS,$POS;
 		push @FieldLEN,$LEN;
 
-		$fld_len += $LEN;
+		$rec_len += $LEN;
 	}
 
 	# Get Variable Fields
 
-	read($self->{'fileMST'},$buff,$fld_len);
+	read($self->{'fileMST'},$buff,$rec_len);
+
+	print STDERR "## rec_len: $rec_len poc: ",tell($self->{'fileMST'})."\n" if ($self->{debug});
 
 	for (my $i = 0 ; $i < $NVF ; $i++) {
 		# skip zero-sized fields
@@ -373,6 +376,8 @@
 	}
 	close(fileMST);
 
+	$self->{'current_mfn'} = $mfn;
+
 	print Dumper($self),"\n" if ($self->{debug});
 
 	return $self->{'record'};
@@ -467,7 +472,7 @@
 	my $mfn = shift || confess "need mfn!";
 
 	# init record to include MFN as field 000
-	my $rec = { '000' => $mfn };
+	my $rec = { '000' => [ $mfn ] };
 
 	my $row = $self->fetch($mfn);