BEGIN {
use Exporter ();
use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
- $VERSION = 0.08;
+ $VERSION = 0.09;
@ISA = qw (Exporter);
#Give a hoot don't pollute, do not export more than needed by default
@EXPORT = qw ();
isisdb => './cds/cds',
);
- for(my $mfn = 1; $mfn <= $isis->{'maxmfn'}; $mfn++) {
+ for(my $mfn = 1; $mfn <= $isis->count; $mfn++) {
print $isis->to_ascii($mfn),"\n";
}
=head1 DESCRIPTION
This module will read ISIS databases created by DOS CDS/ISIS, WinIsis or
-IsisMarc. It can be used as perl-only alternative to OpenIsis module.
+IsisMarc. It can be used as perl-only alternative to OpenIsis module which
+seems to depriciate it's old C<XS> bindings for perl.
It can create hash values from data in ISIS database (using C<to_hash>),
ASCII dump (using C<to_ascii>) or just hash with field names and packed
It also has support for identifiers (only if ISIS database is created by
IsisMarc), see C<to_hash>.
-This will module will always be slower than OpenIsis module which use C
+This module will always be slower than 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. I hope that it
creates data structures which are easier to use than ones created by
=back
-It will also set C<$isis-E<gt>{'maxmfn'}> which is maximum MFN stored in database.
-
=cut
sub new {
read($self->{'fileMST'}, $buff, 4);
$self->{'NXTMFN'}=unpack("l",$buff) || carp "NXTNFN is zero";
- # save maximum MFN
- $self->{'maxmfn'} = $self->{'NXTMFN'} - 1;
-
$self ? return $self : return undef;
}
+=head2 count
+
+Return number of records in database
+
+ print $isis->count;
+
+=cut
+
+sub count {
+ my $self = shift;
+ return $self->{'NXTMFN'} - 1;
+}
+
=head2 read_cnt
-This function is not really used by module, but can be useful to find info
-about your index (if debugging it for example).
+Read content of C<.CNT> file and return hash containing it.
print Dumper($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 {
open(fileCNT, $self->{cnt_file}) || croak "can't read '$self->{cnt_file}': $!";
- # There is two 26 Bytes fixed lenght records
-
- # 0: IDTYPE BTree type 16
- # 2: ORDN Nodes Order 16
- # 4: ORDF Leafs Order 16
- # 6: N Number of Memory buffers for nodes 16
- # 8: K Number of buffers for first level index 16
- # 10: LIV Current number of Index Levels 16
- # 12: POSRX* Pointer to Root Record in N0x 32
- # 16: NMAXPOS* Next Available position in N0x 32
- # 20: FMAXPOS* Next available position in L0x 32
- # 24: ABNORMAL Formal BTree normality indicator 16
- # length: 26 bytes
-
- 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("ssssssllls", $buff);
-
- print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
-
- my $IDTYPE = shift @arr;
- foreach (@flds) {
- $self->{cnt}->{$IDTYPE}->{$_} = abs(shift @arr);
- }
- }
-
my $buff;
read(fileCNT, $buff, 26);
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("ssssssllls", $buff);
+
+ print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'});
+
+ my $IDTYPE = shift @arr;
+ foreach (@flds) {
+ $self->{cnt}->{$IDTYPE}->{$_} = abs(shift @arr);
+ }
+}
+
=head2 fetch
Read record with selected MFN
# (XRFMFB - 1) * 512 + XRFMFP
# why do i have to do XRFMFP % 1024 ?
- my $blk_off = (($XRFMFB - 1) * 512) + ($XRFMFP % 1024);
+ my $blk_off = (($XRFMFB - 1) * 512) + ($XRFMFP % 512);
print STDERR "## pointer: $pointer XRFMFB: $XRFMFB XRFMFP: $XRFMFP offset: $blk_off\n" if ($self->{'debug'});
print STDERR "## offset for rowid $value is $blk_off (blk $XRFMFB off $XRFMFP)\n" if ($self->{debug});
if ($value!=$mfn) {
- carp "Error: MFN ".$mfn." not found in MST(".$value.")";
- #return;
+ if ($value == 0) {
+ print STDERR "## record $mfn is physically deleted\n" if ($self->{debug});
+ $self->{deleted} = $mfn;
+ return;
+ }
+
+ carp "Error: MFN ".$mfn." not found in MST file, found $value";
+ return;
}
read($self->{'fileMST'}, $buff, 14);
=head2 to_ascii
-Dump ASCII output of record with specified MFN
+Returns ASCII output of record with specified MFN
print $isis->to_ascii(42);
-It outputs something like this:
+This outputs something like this:
210 ^aNew York^cNew York University press^dcop. 1988
990 2140
my $hash = $isis->to_hash($mfn);
-It has ability to convert characters (using C<hash_filter> from ISIS
+It has ability to convert characters (using C<hash_filter>) from ISIS
database before creating structures enabling character re-mapping or quick
fix-up of data.
=head1 BUGS
-This module has been very lightly tested. Use with caution and report bugs.
+Some parts of CDS/ISIS documentation are not detailed enough to exmplain
+some variations in input databases which has been tested with this module.
+When I was in doubt, I assumed that OpenIsis's implementation was right
+(except for obvious bugs).
+
+However, every effort has been made to test this module with as much
+databases (and programs that create them) as possible.
+
+I would be very greatful for success or failure reports about usage of this
+module with databases from programs other than WinIsis and IsisMarc. I had
+tested this against ouput of one C<isis.dll>-based application, but I don't
+know any details about it's version.
=head1 AUTHOR
projects / Biblio-Isis / blobdiff