--- branches/Sack/lib/WebPAC/Input/ISI.pm	2009/09/21 19:04:14	1310
+++ branches/Sack/lib/WebPAC/Input/ISI.pm	2009/09/21 19:36:09	1311
@@ -7,6 +7,7 @@
 use base qw/WebPAC::Common/;
 
 use Data::Dump qw/dump/;
+use Carp qw/confess/;
 
 =head1 NAME
 
@@ -14,7 +15,10 @@
 
 =cut
 
-our $VERSION = '0.03';
+our $VERSION = '0.04';
+
+our $debug = 0;
+
 
 =head1 SYNOPSIS
 
@@ -77,9 +81,7 @@
 
 	my $arg = {@_};
 
-	my $log = $self->_get_logger();
-
-	open( my $fh, '<', $arg->{path} ) || $log->logconfess("can't open $arg->{path}: $!");
+	open( my $fh, '<', $arg->{path} ) || confess "can't open $arg->{path}: $!";
 
 	my ( $format, $version );
 
@@ -88,7 +90,7 @@
 	if ( $line =~ /^FN\s(.+)$/) {
 		$format = $1;
 	} else {
-		$log->logdie("first line of $arg->{path} has to be FN, but is: $line");
+		die "first line of $arg->{path} has to be FN, but is: $line";
 	}
 
 	$line = <$fh>;
@@ -96,55 +98,73 @@
 	if ( $line =~ /^VR\s(.+)$/) {
 		$version = $1;
 	} else {
-		$log->logdie("second line of $arg->{path} has to be VN, but is: $line");
+		die "second line of $arg->{path} has to be VN, but is: $line";
+	}
+
+	warn "I: $arg->{path} $format $version - generating record offsets\n";
+
+	$self->{fh} = $fh;
+	$self->{record_offset} = [];
+
+	while( $line = <$fh> ) {
+		chomp($line);
+		next unless $line eq 'ER';
+		push @{ $self->{record_offset} }, tell($fh);
+		last if $#{ $self->{record_offset} } > $self->{offset} + $self->{limit};
 	}
+	push @{ $self->{record_offset} }, tell($fh); # end of file
+
+	warn "I $arg->{path} read ", tell($fh), " bytes $#{ $self->{record_offset} } records\n";
+
+	return $self;
+}
+
+
+
+=head2 fetch_rec
+
+Return record with ID C<$mfn> from database
+
+  my $rec = $input->fetch_rec( $mfn, $filter_coderef );
+
+=cut
+
+sub fetch_rec {
+	my ( $self, $mfn, $filter_coderef ) = @_;
 
-	$log->info("opening $format $version database '$arg->{path}'");
+	seek $self->{fh}, $self->{record_offset}->[ $mfn - 1 ], 0;
 
 	my $tag;
 	my $rec;
 
-	my $offset = $self->{offset} || 0;
-	my $limit  = $self->{limit}  || 0;
+	my $fh = $self->{fh};
 
-	my $file_pos = 0;
-	my $end_pos  = 0;
-	$end_pos = $offset + $limit if $limit;
-
-	$self->{_rec} = [];
-	
-	warn "# offset: $offset limit: $limit end: $end_pos";
-
-	while( $line = <$fh> ) {
+	while( my $line = <$fh> ) {
 		chomp($line);
 		my $v;
 
 		if ( $line eq 'EF' ) {
-			last;
+			return;
 		} elsif ( $line eq 'ER' ) {
-			$file_pos++;
-			last if $end_pos && $file_pos > $end_pos;
 
-			if ( ! $offset || $file_pos > $offset ) {
+			$line = <$fh>;
+			chomp $line;
+			die "expected blank like in ",$self->{path}, " +$.: $line" unless $line eq '';
 
-				# join tags
-				foreach ( qw/AB DE ID TI SO RP SC FU FX PA JI/ ) {
-					$rec->{$_} = join(' ', @{ $rec->{$_} }) if defined $rec->{$_};
-				}
-				# split on ;
-				foreach ( qw/ID SC DE/ ) {
-					$rec->{$_} = [ split(/;\s/, $rec->{$_}) ] if defined $rec->{$_};
-				}
-				$rec->{'000'} = [ $file_pos ];
-				push @{ $self->{_rec} }, $rec;
+			# join tags
+			foreach ( qw/AB DE ID TI SO RP SC FU FX PA JI/ ) {
+				$rec->{$_} = join(' ', @{ $rec->{$_} }) if defined $rec->{$_};
 			}
 
-			$rec = {};
-			$line = <$fh>;
-			chomp $line;
-			$log->logdie("expected blank like in ",$arg->{path}, " +$.: $line") unless ( $line eq '' );
-		} elsif ( $offset && $file_pos < $offset ) {
-			next;
+			# split on ;
+			foreach ( qw/ID SC DE/ ) {
+				$rec->{$_} = [ split(/;\s/, $rec->{$_}) ] if defined $rec->{$_};
+			}
+
+			$rec->{'000'} = [ $mfn ];
+			warn "## mfn $mfn" if $debug;
+			return $rec;
+
 		} elsif ( $line =~ /^(\S\S)\s(.+)$/ ) {
 			$tag = $1;
 			$v = $2;
@@ -157,39 +177,21 @@
 				$v .= $doi;
 			}
 		} elsif ( $line =~ m{^(\S\S)\s*$} ) {
-			warn "# $arg->{path} +$. empty |$line|\n";
-		} else {
-			$log->logdie("can't parse +$. $arg->{path} |$line|");
+			warn "# $self->{path} +$. empty |$line|\n";
+		} elsif ( $line ne '' ) {
+			warn "E: $self->{path} +$ | can't parse |$line|";
 		}
 
 		if ( defined $v ) {
 			$v = $subfields->{$tag}->($v) if defined $subfields->{$tag};
 
-			$log->debug("$tag: ", sub { dump( $v ) });
+			warn "## $tag: ", sub { dump( $v ) } if $debug;
 			push @{ $rec->{$tag} }, $v;
 		}
-
 	}
-	$log->debug("loaded ", $self->size, " records");
-
-	$self ? return $self : return undef;
-}
-
-=head2 fetch_rec
-
-Return record with ID C<$mfn> from database
-
-  my $rec = $input->fetch_rec( $mfn, $filter_coderef );
-
-=cut
-
-sub fetch_rec {
-	my $self = shift;
-
-	my ( $mfn, $filter_coderef ) = @_;
 
-	$mfn -= $self->{offset} if $self->{offset};
-	return $self->{_rec}->[$mfn-1];
+	warn "can't get full record $mfn got ", dump $rec;
+	return $rec;
 }
 
 
@@ -203,20 +205,18 @@
 
 sub size {
 	my $self = shift;
-	$#{ $self->{_rec} } + 1;
+	$#{ $self->{record_offset} } - $self->{offset};
+	# no need for +1 since we record end of file as last record
 }
 
-=head1 SEE ALSO
 
-L<http://isibasic.com/help/helpprn.html> is only sane source of document format which Google could find...
- 
 =head1 AUTHOR
 
 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
 
 =head1 COPYRIGHT & LICENSE
 
-Copyright 2007 Dobrica Pavlinusic, All Rights Reserved.
+Copyright 2009 Dobrica Pavlinusic, All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it
 under the same terms as Perl itself.