From 5a6197e3a595e08faff9a7f4a139a982e73b4b89 Mon Sep 17 00:00:00 2001
From: Dobrica Pavlinusic <dpavlin@rot13.org>
Date: Wed, 5 Jan 2005 21:23:04 +0000
Subject: [PATCH] - make filehandles locally scoped - changed unpack to
 portable big-endian (so that it works on little-endian   machines; tested
 with PearPC and OpenDarwin) - added carps where missing - added binmode when
 opening files - any argument to 002_isis.t will show debugging output

git-svn-id: file:///home/dpavlin/svn/Biblio-Isis/trunk@33 4670fa4d-42ec-0310-ab5b-a66af6943492
---
 IsisDB.pm    | 46 ++++++++++++++++++++++++----------------------
 t/002_isis.t |  3 +++
 2 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/IsisDB.pm b/IsisDB.pm
index 75d4e5f..5a25d5b 100644
--- a/IsisDB.pm
+++ b/IsisDB.pm
@@ -158,9 +158,10 @@ sub new {
 		# read the $db.FDT file for tags
 		my $fieldzone=0;
 
-		open(fileFDT, $self->{fdt_file}) || croak "can't read '$self->{fdt_file}': $!";
+		open(my $fileFDT, $self->{fdt_file}) || croak "can't read '$self->{fdt_file}': $!";
+		binmode($fileFDT);
 
-		while (<fileFDT>) {
+		while (<$fileFDT>) {
 			chomp;
 			if ($fieldzone) {
 				my $name=substr($_,0,30);
@@ -177,12 +178,13 @@ sub new {
 			}
 		}
 		
-		close(fileFDT);
+		close($fileFDT);
 	}
 
 	# Get the Maximum MFN from $db.MST
 
 	open($self->{'fileMST'}, $self->{mst_file}) || croak "can't open '$self->{mst_file}': $!";
+	binmode($self->{'fileMST'});
 
 	# MST format:	(* = 32 bit signed)
 	# CTLMFN*	always 0
@@ -190,20 +192,18 @@ sub new {
 	# 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($self->{'fileMST'},4,0);
+	seek($self->{'fileMST'},4,0) || carp "can't seek to offset 0 in MST: $!";
 
 	my $buff;
 
-	read($self->{'fileMST'}, $buff, 4);
-	$self->{'NXTMFN'}=unpack("l",$buff) || carp "NXTNFN is zero";
-
-
-
+	read($self->{'fileMST'}, $buff, 4) || carp "can't read NXTMFN from MST: $!";
+	$self->{'NXTMFN'}=unpack("V",$buff) || carp "NXTNFN is zero";
 
 	print STDERR Dumper($self),"\n" if ($self->{debug});
 
 	# open files for later
 	open($self->{'fileXRF'}, $self->{xrf_file}) || croak "can't open '$self->{xrf_file}': $!";
+	binmode($self->{'fileXRF'});
 
 	$self ? return $self : return undef;
 }
@@ -240,17 +240,18 @@ sub read_cnt  {
 
 	# Get the index information from $db.CNT
    
-	open(fileCNT, $self->{cnt_file}) || croak "can't read '$self->{cnt_file}': $!";
+	open(my $fileCNT, $self->{cnt_file}) || carp "can't read '$self->{cnt_file}': $!";
+	binmode($fileCNT);
 
 	my $buff;
 
-	read(fileCNT, $buff, 26);
+	read($fileCNT, $buff, 26) || carp "can't read first table from CNT: $!";
 	$self->unpack_cnt($buff);
 
-	read(fileCNT, $buff, 26);
+	read($fileCNT, $buff, 26) || carp "can't read second table from CNT: $!";
 	$self->unpack_cnt($buff);
 
-	close(fileCNT);
+	close($fileCNT);
 
 	return $self->{cnt};
 }
@@ -284,7 +285,7 @@ sub unpack_cnt {
 	my @flds = qw(ORDN ORDF N K LIV POSRX NMAXPOS FMAXPOS ABNORMAL);
 
 	my $buff = shift || return;
-	my @arr = unpack("ssssssllls", $buff);
+	my @arr = unpack("vvvvvvVVVv", $buff);
 
 	print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
 
@@ -334,16 +335,17 @@ sub fetch {
 
 	# read XRFMFB abd XRFMFP
 	read($self->{'fileXRF'}, $buff, 4);
-	my $pointer=unpack("l",$buff) || carp "pointer is null";
+	my $pointer=unpack("V",$buff) || carp "pointer is null";
 
 	# check for logically deleted record
-	if ($pointer < 0) {
+	if ($pointer & 0x80000000) {
 		print STDERR "## record $mfn is logically deleted\n" if ($self->{debug});
 		$self->{deleted} = $mfn;
 
 		return unless $self->{include_deleted};
 
-		$pointer = abs($pointer);
+		# abs
+		$pointer = ($pointer ^ 0xffffffff) + 1;
 	}
 
 	my $XRFMFB = int($pointer/2048);
@@ -358,10 +360,10 @@ sub fetch {
 
 	# Get Record Information
 
-	seek($self->{'fileMST'},$blk_off,0);
+	seek($self->{'fileMST'},$blk_off,0) || croak "can't seek to $blk_off: $!";
 
-	read($self->{'fileMST'}, $buff, 4);
-	my $value=unpack("l",$buff);
+	read($self->{'fileMST'}, $buff, 4) || croak "can't read 4 bytes at offset $blk_off from MST file: $!";
+	my $value=unpack("V",$buff);
 
 	print STDERR "## offset for rowid $value is $blk_off (blk $XRFMFB off $XRFMFP)\n" if ($self->{debug});
 
@@ -378,7 +380,7 @@ sub fetch {
 
 	read($self->{'fileMST'}, $buff, 14);
 
-	my ($MFRL,$MFBWB,$MFBWP,$BASE,$NVF,$STATUS) = unpack("slssss", $buff);
+	my ($MFRL,$MFBWB,$MFBWP,$BASE,$NVF,$STATUS) = unpack("vVvvvv", $buff);
 
 	print STDERR "## MFRL: $MFRL MFBWB: $MFBWB MFBWP: $MFBWP BASE: $BASE NVF: $NVF STATUS: $STATUS\n" if ($self->{debug});
 
@@ -398,7 +400,7 @@ sub fetch {
 
 	for (my $i = 0 ; $i < $NVF ; $i++) {
 
-		my ($TAG,$POS,$LEN) = unpack("sss", substr($buff,$i * 6, 6));
+		my ($TAG,$POS,$LEN) = unpack("vvv", substr($buff,$i * 6, 6));
 
 		print STDERR "## TAG: $TAG POS: $POS LEN: $LEN\n" if ($self->{debug});
 
diff --git a/t/002_isis.t b/t/002_isis.t
index 6594491..ec2d510 100755
--- a/t/002_isis.t
+++ b/t/002_isis.t
@@ -9,6 +9,7 @@ use Test::More tests => 110;
 
 BEGIN { use_ok( 'IsisDB' ); }
 
+my $debug = shift @ARGV;
 my $isis;
 
 sub test_data {
@@ -124,6 +125,7 @@ sub test_data {
 $isis = IsisDB->new (
 	isisdb => './data/winisis/BIBL',
 	include_deleted => 1,
+	debug => $debug,
 );
 
 print Dumper($isis);
@@ -166,6 +168,7 @@ cmp_ok($isis->{deleted}, '==', 3, "MFN 3 is deleted");
 
 $isis = IsisDB->new (
 	isisdb => './data/winisis/BIBL',
+	debug => $debug,
 );
 
 ok(! $isis->fetch(3), "deleted not found");
-- 
2.20.1