documented hash_filter, fully implemented repeatable subfileds. [0.03]

[MARC-Fast] / Fast.pm

diff --git a/Fast.pm b/Fast.pm
index 9a981be..7f2a618 100644 (file)
--- a/Fast.pm
+++ b/Fast.pm
@@ -7,7 +7,7 @@ use Data::Dumper;
 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 ();
@@ -42,6 +42,11 @@ Read MARC database
        quiet => 0,
        debug => 0,
        assert => 0,
+       hash_filter => sub {
+               my $t = shift;
+               $t =~ s/foo/bar/;
+               return $t;
+       },
   );
 
 =cut
@@ -59,6 +64,7 @@ sub new {
        print STDERR "# opening ",$self->{marcdb},"\n" if ($self->{debug});
 
        open($self->{fh}, $self->{marcdb}) || croak "can't open ",$self->{marcdb},": $!";
+       binmode($self->{fh});
 
        $self->{count} = 0;
 
@@ -69,7 +75,12 @@ sub new {
                push @{$self->{fh_offset}}, tell($self->{fh});
 
                my $leader;
-               read($self->{fh}, $leader, 24);
+               my $len = read($self->{fh}, $leader, 24);
+
+               if ($len < 24) {
+                       carp "short read of leader, aborting\n";
+                       last;
+               }
 
                # Byte        Name
                # ----        ----
@@ -103,7 +114,12 @@ sub new {
                push @{$self->{leaders}}, $leader;
 
                # skip to next record
-               seek($self->{fh},substr($leader,0,5)-24,1);
+               my $o = substr($leader,0,5);
+               if ($o > 24) {
+                       seek($self->{fh},$o-24,1) if ($o);
+               } else {
+                       last;
+               }
 
        }
 
@@ -196,11 +212,7 @@ sub fetch {
                my $f = substr($fields,$addr,$len);
                print STDERR "tag/len/addr $tag [$len] $addr: '$f'\n" if ($self->{debug});
 
-               if ($row->{$tag}) {
-                       $row->{$tag} .= $f;
-               } else {
-                       $row->{$tag} = $f;
-               }
+               push @{ $row->{$tag} }, $f;
 
                my $del = substr($fields,$addr+$len-1,1);
 
@@ -221,6 +233,87 @@ sub fetch {
        return $row;
 }
 
+
+=head2 to_hash
+
+Read record with specified MFN and convert it to hash
+
+  my $hash = $marc->to_hash($mfn);
+
+It has ability to convert characters (using C<hash_filter>) from MARC
+database before creating structures enabling character re-mapping or quick
+fix-up of data.
+
+This function returns hash which is like this:
+
+  '200' => [
+             {
+               'i1' => '1',
+               'i2' => ' '
+               'a' => 'Goa',
+               'f' => 'Valdo D\'Arienzo',
+               'e' => 'tipografie e tipografi nel XVI secolo',
+             }
+           ],
+
+This method will also create additional field C<000> with MFN.
+
+=cut
+
+sub to_hash {
+       my $self = shift;
+
+       my $mfn = shift || confess "need mfn!";
+
+       # init record to include MFN as field 000
+       my $rec = { '000' => [ $mfn ] };
+
+       my $row = $self->fetch($mfn) || return;
+
+       foreach my $k (keys %{$row}) {
+               foreach my $l (@{$row->{$k}}) {
+
+                       # remove end marker
+                       $l =~ s/\x1E$//;
+
+                       # filter output
+                       $l = $self->{'hash_filter'}->($l) if ($self->{'hash_filter'});
+
+                       my $val;
+
+                       # has identifiers?
+                       ($val->{'i1'},$val->{'i2'}) = ($1,$2) if ($l =~ s/^([01 #])([01 #])\x1F/\x1F/);
+
+                       # has subfields?
+                       if ($l =~ m/\x1F/) {
+                               foreach my $t (split(/\x1F/,$l)) {
+                                       next if (! $t);
+                                       my $f = substr($t,0,1);
+                                       # repeatable subfileds. When we hit first one,
+                                       # store CURRENT (up to that) in first repetition
+                                       # of this record. Then, new record with same
+                                       # identifiers will be created.
+                                       if ($val->{$f}) {
+                                               push @{$rec->{$k}}, $val;
+                                               $val = {
+                                                       i1 => $val->{i1},
+                                                       i2 => $val->{i2},
+                                               };
+                                       }
+                                       $val->{substr($t,0,1)} = substr($t,1);
+                               }
+                       } else {
+                               $val = $l;
+                       }
+
+                       push @{$rec->{$k}}, $val;
+               }
+       }
+
+       return $rec;
+}
+
+
 1;
 __END__