lib/WebPAC/Input.pm

package WebPAC::Input;

use warnings;
use strict;

use blib;

use WebPAC::Common;
use base qw/WebPAC::Common/;
use Text::Iconv;
use Data::Dumper;

=head1 NAME

WebPAC::Input - read different file formats into WebPAC

=head1 VERSION

Version 0.11

=cut

our $VERSION = '0.11';

=head1 SYNOPSIS

This module implements input as database which have fixed and known
I<size> while indexing and single unique numeric identifier for database
position ranging from 1 to I<size>.

Simply, something that is indexed by unmber from 1 .. I<size>.

Examples of such databases are CDS/ISIS files, MARC files, lines in
text file, and so on.

Specific file formats are implemented using low-level interface modules,
located in C<WebPAC::Input::*> namespace which export C<open_db>,
C<fetch_rec> and optional C<init> functions.

Perhaps a little code snippet.

        use WebPAC::Input;

        my $db = WebPAC::Input->new(
                module => 'WebPAC::Input::ISIS',
                low_mem => 1,
        );

        $db->open( path => '/path/to/database' );
        print "database size: ",$db->size,"\n";
        while (my $rec = $db->fetch) {
                # do something with $rec
        }


=head1 FUNCTIONS

=head2 new

Create new input database object.

  my $db = new WebPAC::Input(
        module => 'WebPAC::Input::MARC',
        encoding => 'ISO-8859-2',
        low_mem => 1,
        recode => 'char pairs',
        no_progress_bar => 1,
  );

C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
L<WebPAC::Input::MARC>.

Optional parametar C<encoding> specify application code page (which will be
used internally). This should probably be your terminal encoding, and by
default, it C<ISO-8859-2>.

Default is not to use C<low_mem> options (see L<MEMORY USAGE> below).

C<recode> is optional string constisting of character or words pairs that
should be replaced in input stream.

C<no_progress_bar> disables progress bar output on C<STDOUT>

This function will also call low-level C<init> if it exists with same
parametars.

=cut

sub new {
        my $class = shift;
        my $self = {@_};
        bless($self, $class);

        my $log = $self->_get_logger;

        $log->logconfess("code_page argument is not suppored any more. change it to encoding") if ($self->{lookup});
        $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_ref") if ($self->{lookup});

        $log->logconfess("specify low-level file format module") unless ($self->{module});
        my $module = $self->{module};
        $module =~ s#::#/#g;
        $module .= '.pm';
        $log->debug("require low-level module $self->{module} from $module");

        require $module;
        #eval $self->{module} .'->import';

        # check if required subclasses are implemented
        foreach my $subclass (qw/open_db fetch_rec init/) {
                my $n = $self->{module} . '::' . $subclass;
                if (! defined &{ $n }) {
                        my $missing = "missing $subclass in $self->{module}";
                        $self->{$subclass} = sub { $log->logwarn($missing) };
                } else {
                        $self->{$subclass} = \&{ $n };
                }
        }

        if ($self->{init}) {
                $log->debug("calling init");
                $self->{init}->($self, @_);
        }

        $self->{'encoding'} ||= 'ISO-8859-2';

        # running with low_mem flag? well, use DBM::Deep then.
        if ($self->{'low_mem'}) {
                $log->info("running with low_mem which impacts performance (<32 Mb memory usage)");

                my $db_file = "data.db";

                if (-e $db_file) {
                        unlink $db_file or $log->logdie("can't remove '$db_file' from last run");
                        $log->debug("removed '$db_file' from last run");
                }

                require DBM::Deep;

                my $db = new DBM::Deep $db_file;

                $log->logdie("DBM::Deep error: $!") unless ($db);

                if ($db->error()) {
                        $log->logdie("can't open '$db_file' under low_mem: ",$db->error());
                } else {
                        $log->debug("using file '$db_file' for DBM::Deep");
                }

                $self->{'db'} = $db;
        }

        $self ? return $self : return undef;
}

=head2 open

This function will read whole database in memory and produce lookups.

 $input->open(
        path => '/path/to/database/file',
        code_page => '852',
        limit => 500,
        offset => 6000,
        lookup => $lookup_obj,
        stats => 1,
        lookup_ref => sub {
                my ($k,$v) = @_;
                # store lookup $k => $v
        },
        modify_records => {
                900 => { '^a' => { ' : ' => '^b' } },
                901 => { '*' => { '^b' => ' ; ' } },
        },
 );

By default, C<code_page> is assumed to be C<852>.

C<offset> is optional parametar to position at some offset before reading from database.

C<limit> is optional parametar to read just C<limit> records from database

C<stats> create optional report about usage of fields and subfields

C<lookup_coderef> is closure to call when adding C<< key => 'value' >> combinations to
lookup.

C<modify_records> specify mapping from subfields to delimiters or from
delimiters to subfields, as well as oprations on fields (if subfield is
defined as C<*>.

Returns size of database, regardless of C<offset> and C<limit>
parametars, see also C<size>.

=cut

sub open {
        my $self = shift;
        my $arg = {@_};

        my $log = $self->_get_logger();

        $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_coderef") if ($arg->{lookup});
        $log->logconfess("lookup_coderef must be CODE, not ",ref($arg->{lookup_coderef}))
                if ($arg->{lookup_coderef} && ref($arg->{lookup_coderef}) ne 'CODE');

        $log->logcroak("need path") if (! $arg->{'path'});
        my $code_page = $arg->{'code_page'} || '852';

        # store data in object
        $self->{'input_code_page'} = $code_page;
        foreach my $v (qw/path offset limit/) {
                $self->{$v} = $arg->{$v} if ($arg->{$v});
        }

        # create Text::Iconv object
        $self->{iconv} = Text::Iconv->new($code_page,$self->{'encoding'});      ## FIXME remove!

        my $filter_ref;
        my $recode_regex;
        my $recode_map;

        if ($self->{recode}) {
                my @r = split(/\s/, $self->{recode});
                if ($#r % 2 != 1) {
                        $log->logwarn("recode needs even number of elements (some number of valid pairs)");
                } else {
                        while (@r) {
                                my $from = shift @r;
                                my $to = shift @r;
                                $recode_map->{$from} = $to;
                        }

                        $recode_regex = join '|' => keys %{ $recode_map };

                        $log->debug("using recode regex: $recode_regex");
                }

        }

        my $rec_regex = $self->modify_record_regexps(%{ $arg->{modify_records} });
        $log->debug("rec_regex: ", Dumper($rec_regex));

        my ($db, $size) = $self->{open_db}->( $self, 
                path => $arg->{path},
                filter => sub {
                                my ($l,$f_nr) = @_;
                                return unless defined($l);

                                ## FIXME remove iconv!
                                $l = $self->{iconv}->convert($l) if ($self->{iconv});
        
                                $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);

                                ## FIXME remove this warning when we are sure that none of API is calling
                                ## this wrongly
                                warn "filter called without field number" unless ($f_nr);

                                return $l;
                },
                %{ $arg },
        );

        unless (defined($db)) {
                $log->logwarn("can't open database $arg->{path}, skipping...");
                return;
        }

        unless ($size) {
                $log->logwarn("no records in database $arg->{path}, skipping...");
                return;
        }

        my $from_rec = 1;
        my $to_rec = $size;

        if (my $s = $self->{offset}) {
                $log->debug("skipping to MFN $s");
                $from_rec = $s;
        } else {
                $self->{offset} = $from_rec;
        }

        if ($self->{limit}) {
                $log->debug("limiting to ",$self->{limit}," records");
                $to_rec = $from_rec + $self->{limit} - 1;
                $to_rec = $size if ($to_rec > $size);
        }

        # store size for later
        $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;

        $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');

        # read database
        for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {

                $log->debug("position: $pos\n");

                my $rec = $self->{fetch_rec}->($self, $db, $pos, sub {
                                my ($l,$f_nr) = @_;
                                return unless defined($l);
                                return $l unless ($rec_regex && $f_nr);

                                # apply regexps
                                if ($rec_regex && defined($rec_regex->{$f_nr})) {
                                        $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
                                        my $c = 0;
                                        foreach my $r (@{ $rec_regex->{$f_nr} }) {
                                                #$log->debug("\$l = $l\neval \$l =~ $r");
                                                eval '$l =~ ' . $r;
                                                $log->error("error applying regex: $r") if ($@);
                                        }
                                }

                                return $l;
                });

                $log->debug(sub { Dumper($rec) });

                if (! $rec) {
                        $log->warn("record $pos empty? skipping...");
                        next;
                }

                # store
                if ($self->{low_mem}) {
                        $self->{db}->put($pos, $rec);
                } else {
                        $self->{data}->{$pos} = $rec;
                }

                # create lookup
                $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});

                # update counters for statistics
                if ($self->{stats}) {

                        # fetch clean record with regexpes applied for statistics
                        my $rec = $self->{fetch_rec}->($self, $db, $pos);

                        foreach my $fld (keys %{ $rec }) {
                                $self->{_stats}->{fld}->{ $fld }++;

                                $log->logdie("invalid record fild $fld, not ARRAY")
                                        unless (ref($rec->{ $fld }) eq 'ARRAY');
        
                                foreach my $row (@{ $rec->{$fld} }) {

                                        if (ref($row) eq 'HASH') {

                                                foreach my $sf (keys %{ $row }) {
                                                        next if ($sf eq 'subfields');
                                                        $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
                                                        $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
                                                                        if (ref($row->{$sf}) eq 'ARRAY');
                                                }

                                        } else {
                                                $self->{_stats}->{repeatable}->{ $fld }++;
                                        }
                                }
                        }
                }

                $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});

        }

        $self->{pos} = -1;
        $self->{last_pcnt} = 0;

        # store max mfn and return it.
        $self->{max_pos} = $to_rec;
        $log->debug("max_pos: $to_rec");

        return $size;
}

=head2 fetch

Fetch next record from database. It will also displays progress bar.

 my $rec = $isis->fetch;

Record from this function should probably go to C<data_structure> for
normalisation.

=cut

sub fetch {
        my $self = shift;

        my $log = $self->_get_logger();

        $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});

        if ($self->{pos} == -1) {
                $self->{pos} = $self->{offset};
        } else {
                $self->{pos}++;
        }

        my $mfn = $self->{pos};

        if ($mfn > $self->{max_pos}) {
                $self->{pos} = $self->{max_pos};
                $log->debug("at EOF");
                return;
        }

        $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});

        my $rec;

        if ($self->{low_mem}) {
                $rec = $self->{db}->get($mfn);
        } else {
                $rec = $self->{data}->{$mfn};
        }

        $rec ||= 0E0;
}

=head2 pos

Returns current record number (MFN).

 print $isis->pos;

First record in database has position 1.

=cut

sub pos {
        my $self = shift;
        return $self->{pos};
}


=head2 size

Returns number of records in database

 print $isis->size;

Result from this function can be used to loop through all records

 foreach my $mfn ( 1 ... $isis->size ) { ... }

because it takes into account C<offset> and C<limit>.

=cut

sub size {
        my $self = shift;
        return $self->{size};
}

=head2 seek

Seek to specified MFN in file.

 $isis->seek(42);

First record in database has position 1.

=cut

sub seek {
        my $self = shift;
        my $pos = shift || return;

        my $log = $self->_get_logger();

        if ($pos < 1) {
                $log->warn("seek before first record");
                $pos = 1;
        } elsif ($pos > $self->{max_pos}) {
                $log->warn("seek beyond last record");
                $pos = $self->{max_pos};
        }

        return $self->{pos} = (($pos - 1) || -1);
}

=head2 stats

Dump statistics about field and subfield usage

  print $input->stats;

=cut

sub stats {
        my $self = shift;

        my $log = $self->_get_logger();

        my $s = $self->{_stats};
        if (! $s) {
                $log->warn("called stats, but there is no statistics collected");
                return;
        }

        my $max_fld = 0;

        my $out = join("\n",
                map {
                        my $f = $_ || die "no field";
                        my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
                        $max_fld = $v if ($v > $max_fld);

                        my $o = sprintf("%4s %d ~", $f, $v);

                        if (defined($s->{sf}->{$f})) {
                                map {
                                        $o .= sprintf(" %s:%d%s", $_, 
                                                $s->{sf}->{$f}->{$_}->{count},
                                                $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
                                        );
                                } sort keys %{ $s->{sf}->{$f} };
                        }

                        if (my $v_r = $s->{repeatable}->{$f}) {
                                $o .= " ($v_r)" if ($v_r != $v);
                        }

                        $o;
                } sort { $a cmp $b } keys %{ $s->{fld} }
        );

        $log->debug( sub { Dumper($s) } );

        return $out;
}

=head2 modify_record_regexps

Generate hash with regexpes to be applied using L<filter>.

  my $regexpes = $input->modify_record_regexps(
                900 => { '^a' => { ' : ' => '^b' } },
                901 => { '*' => { '^b' => ' ; ' } },
  );

=cut

sub modify_record_regexps {
        my $self = shift;
        my $modify_record = {@_};

        my $regexpes;

        foreach my $f (keys %$modify_record) {
warn "--- f: $f\n";
                foreach my $sf (keys %{ $modify_record->{$f} }) {
warn "---- sf: $sf\n";
                        foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
                                my $to = $modify_record->{$f}->{$sf}->{$from};
                                #die "no field?" unless defined($to);
warn "----- transform: |$from| -> |$to|\n";

                                if ($sf =~ /^\^/) {
                                        my $regex = 
                                                's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
                                        push @{ $regexpes->{$f} }, $regex;
warn ">>>>> $regex [sf]\n";
                                } else {
                                        my $regex =
                                                's/\Q'. $from .'\E/'. $to .'/g';
                                        push @{ $regexpes->{$f} }, $regex;
warn ">>>>> $regex [global]\n";
                                }

                        }
                }
        }

        return $regexpes;
}

=head1 MEMORY USAGE

C<low_mem> options is double-edged sword. If enabled, WebPAC
will run on memory constraint machines (which doesn't have enough
physical RAM to create memory structure for whole source database).

If your machine has 512Mb or more of RAM and database is around 10000 records,
memory shouldn't be an issue. If you don't have enough physical RAM, you
might consider using virtual memory (if your operating system is handling it
well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
parsed structure of ISIS database (this is what C<low_mem> option does).

Hitting swap at end of reading source database is probably o.k. However,
hitting swap before 90% will dramatically decrease performance and you will
be better off with C<low_mem> and using rest of availble memory for
operating system disk cache (Linux is particuallary good about this).
However, every access to database record will require disk access, so
generation phase will be slower 10-100 times.

Parsed structures are essential - you just have option to trade RAM memory
(which is fast) for disk space (which is slow). Be sure to have planty of
disk space if you are using C<low_mem> and thus L<DBM::Deep>.

However, when WebPAC is running on desktop machines (or laptops :-), it's
highly undesireable for system to start swapping. Using C<low_mem> option can
reduce WecPAC memory usage to around 64Mb for same database with lookup
fields and sorted indexes which stay in RAM. Performance will suffer, but
memory usage will really be minimal. It might be also more confortable to
run WebPAC reniced on those machines.


=head1 AUTHOR

Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>

=head1 COPYRIGHT & LICENSE

Copyright 2005-2006 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.

=cut

1; # End of WebPAC::Input
1	dpavlin	1	package WebPAC::Input;
2
3			use warnings;
4			use strict;
5
6	dpavlin	507	use blib;
7
8	dpavlin	487	use WebPAC::Common;
9	dpavlin	285	use base qw/WebPAC::Common/;
10			use Text::Iconv;
11	dpavlin	308	use Data::Dumper;
12	dpavlin	285
13	dpavlin	1	=head1 NAME
14
15	dpavlin	286	WebPAC::Input - read different file formats into WebPAC
16	dpavlin	1
17			=head1 VERSION
18
19	dpavlin	619	Version 0.11
20	dpavlin	1
21			=cut
22
23	dpavlin	619	our $VERSION = '0.11';
24	dpavlin	1
25			=head1 SYNOPSIS
26
27	dpavlin	286	This module implements input as database which have fixed and known
28			I<size> while indexing and single unique numeric identifier for database
29			position ranging from 1 to I<size>.
30	dpavlin	1
31	dpavlin	286	Simply, something that is indexed by unmber from 1 .. I<size>.
32
33			Examples of such databases are CDS/ISIS files, MARC files, lines in
34			text file, and so on.
35
36			Specific file formats are implemented using low-level interface modules,
37			located in C<WebPAC::Input::*> namespace which export C<open_db>,
38			C<fetch_rec> and optional C<init> functions.
39
40	dpavlin	1	Perhaps a little code snippet.
41
42	dpavlin	597	use WebPAC::Input;
43	dpavlin	1
44	dpavlin	597	my $db = WebPAC::Input->new(
45			module => 'WebPAC::Input::ISIS',
46	dpavlin	286	low_mem => 1,
47	dpavlin	597	);
48	dpavlin	1
49	dpavlin	597	$db->open( path => '/path/to/database' );
50	dpavlin	416	print "database size: ",$db->size,"\n";
51			while (my $rec = $db->fetch) {
52			# do something with $rec
53			}
54	dpavlin	1
55	dpavlin	286
56
57	dpavlin	1	=head1 FUNCTIONS
58
59	dpavlin	3	=head2 new
60	dpavlin	1
61	dpavlin	3	Create new input database object.
62
63	dpavlin	9	my $db = new WebPAC::Input(
64	dpavlin	286	module => 'WebPAC::Input::MARC',
65	dpavlin	585	encoding => 'ISO-8859-2',
66	dpavlin	10	low_mem => 1,
67	dpavlin	416	recode => 'char pairs',
68	dpavlin	483	no_progress_bar => 1,
69	dpavlin	9	);
70	dpavlin	3
71	dpavlin	597	C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
72	dpavlin	286	L<WebPAC::Input::MARC>.
73
74	dpavlin	585	Optional parametar C<encoding> specify application code page (which will be
75	dpavlin	9	used internally). This should probably be your terminal encoding, and by
76			default, it C<ISO-8859-2>.
77
78	dpavlin	10	Default is not to use C<low_mem> options (see L<MEMORY USAGE> below).
79
80	dpavlin	483	C<recode> is optional string constisting of character or words pairs that
81			should be replaced in input stream.
82
83			C<no_progress_bar> disables progress bar output on C<STDOUT>
84
85	dpavlin	285	This function will also call low-level C<init> if it exists with same
86			parametars.
87
88	dpavlin	1	=cut
89
90	dpavlin	3	sub new {
91	dpavlin	285	my $class = shift;
92			my $self = {@_};
93	dpavlin	3	bless($self, $class);
94
95	dpavlin	285	my $log = $self->_get_logger;
96
97	dpavlin	585	$log->logconfess("code_page argument is not suppored any more. change it to encoding") if ($self->{lookup});
98			$log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_ref") if ($self->{lookup});
99
100	dpavlin	286	$log->logconfess("specify low-level file format module") unless ($self->{module});
101			my $module = $self->{module};
102			$module =~ s#::#/#g;
103			$module .= '.pm';
104			$log->debug("require low-level module $self->{module} from $module");
105	dpavlin	289
106	dpavlin	286	require $module;
107	dpavlin	289	#eval $self->{module} .'->import';
108	dpavlin	286
109	dpavlin	285	# check if required subclasses are implemented
110	dpavlin	289	foreach my $subclass (qw/open_db fetch_rec init/) {
111			my $n = $self->{module} . '::' . $subclass;
112			if (! defined &{ $n }) {
113	dpavlin	290	my $missing = "missing $subclass in $self->{module}";
114	dpavlin	301	$self->{$subclass} = sub { $log->logwarn($missing) };
115	dpavlin	286	} else {
116	dpavlin	289	$self->{$subclass} = \&{ $n };
117	dpavlin	286	}
118	dpavlin	285	}
119
120	dpavlin	289	if ($self->{init}) {
121	dpavlin	285	$log->debug("calling init");
122	dpavlin	289	$self->{init}->($self, @_);
123	dpavlin	285	}
124
125	dpavlin	585	$self->{'encoding'} \|\|= 'ISO-8859-2';
126	dpavlin	9
127	dpavlin	10	# running with low_mem flag? well, use DBM::Deep then.
128			if ($self->{'low_mem'}) {
129			$log->info("running with low_mem which impacts performance (<32 Mb memory usage)");
130
131			my $db_file = "data.db";
132
133			if (-e $db_file) {
134			unlink $db_file or $log->logdie("can't remove '$db_file' from last run");
135			$log->debug("removed '$db_file' from last run");
136			}
137
138			require DBM::Deep;
139
140			my $db = new DBM::Deep $db_file;
141
142			$log->logdie("DBM::Deep error: $!") unless ($db);
143
144			if ($db->error()) {
145			$log->logdie("can't open '$db_file' under low_mem: ",$db->error());
146			} else {
147			$log->debug("using file '$db_file' for DBM::Deep");
148			}
149
150			$self->{'db'} = $db;
151			}
152
153	dpavlin	3	$self ? return $self : return undef;
154	dpavlin	1	}
155
156	dpavlin	285	=head2 open
157
158			This function will read whole database in memory and produce lookups.
159
160	dpavlin	286	$input->open(
161	dpavlin	285	path => '/path/to/database/file',
162			code_page => '852',
163	dpavlin	286	limit => 500,
164			offset => 6000,
165	dpavlin	285	lookup => $lookup_obj,
166	dpavlin	506	stats => 1,
167	dpavlin	585	lookup_ref => sub {
168			my ($k,$v) = @_;
169			# store lookup $k => $v
170			},
171	dpavlin	597	modify_records => {
172			900 => { '^a' => { ' : ' => '^b' } },
173			901 => { '*' => { '^b' => ' ; ' } },
174			},
175	dpavlin	285	);
176
177			By default, C<code_page> is assumed to be C<852>.
178
179	dpavlin	286	C<offset> is optional parametar to position at some offset before reading from database.
180	dpavlin	285
181	dpavlin	286	C<limit> is optional parametar to read just C<limit> records from database
182	dpavlin	285
183	dpavlin	506	C<stats> create optional report about usage of fields and subfields
184
185	dpavlin	597	C<lookup_coderef> is closure to call when adding C<< key => 'value' >> combinations to
186	dpavlin	585	lookup.
187
188	dpavlin	597	C<modify_records> specify mapping from subfields to delimiters or from
189			delimiters to subfields, as well as oprations on fields (if subfield is
190			defined as C<*>.
191
192	dpavlin	286	Returns size of database, regardless of C<offset> and C<limit>
193			parametars, see also C<size>.
194	dpavlin	285
195			=cut
196
197			sub open {
198			my $self = shift;
199			my $arg = {@_};
200
201			my $log = $self->_get_logger();
202
203	dpavlin	585	$log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_coderef") if ($arg->{lookup});
204			$log->logconfess("lookup_coderef must be CODE, not ",ref($arg->{lookup_coderef}))
205			if ($arg->{lookup_coderef} && ref($arg->{lookup_coderef}) ne 'CODE');
206
207	dpavlin	285	$log->logcroak("need path") if (! $arg->{'path'});
208			my $code_page = $arg->{'code_page'} \|\| '852';
209
210			# store data in object
211	dpavlin	292	$self->{'input_code_page'} = $code_page;
212	dpavlin	286	foreach my $v (qw/path offset limit/) {
213	dpavlin	285	$self->{$v} = $arg->{$v} if ($arg->{$v});
214			}
215
216			# create Text::Iconv object
217	dpavlin	585	$self->{iconv} = Text::Iconv->new($code_page,$self->{'encoding'}); ## FIXME remove!
218	dpavlin	285
219	dpavlin	416	my $filter_ref;
220	dpavlin	597	my $recode_regex;
221			my $recode_map;
222	dpavlin	416
223			if ($self->{recode}) {
224			my @r = split(/\s/, $self->{recode});
225			if ($#r % 2 != 1) {
226			$log->logwarn("recode needs even number of elements (some number of valid pairs)");
227			} else {
228			while (@r) {
229			my $from = shift @r;
230			my $to = shift @r;
231	dpavlin	597	$recode_map->{$from} = $to;
232	dpavlin	416	}
233
234	dpavlin	597	$recode_regex = join '\|' => keys %{ $recode_map };
235	dpavlin	416
236	dpavlin	597	$log->debug("using recode regex: $recode_regex");
237	dpavlin	416	}
238
239			}
240
241	dpavlin	597	my $rec_regex = $self->modify_record_regexps(%{ $arg->{modify_records} });
242			$log->debug("rec_regex: ", Dumper($rec_regex));
243
244	dpavlin	289	my ($db, $size) = $self->{open_db}->( $self,
245	dpavlin	285	path => $arg->{path},
246	dpavlin	597	filter => sub {
247			my ($l,$f_nr) = @_;
248			return unless defined($l);
249
250			## FIXME remove iconv!
251			$l = $self->{iconv}->convert($l) if ($self->{iconv});
252
253			$l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
254
255	dpavlin	599	## FIXME remove this warning when we are sure that none of API is calling
256			## this wrongly
257	dpavlin	619	warn "filter called without field number" unless ($f_nr);
258	dpavlin	597
259			return $l;
260			},
261	dpavlin	523	%{ $arg },
262	dpavlin	285	);
263
264	dpavlin	496	unless (defined($db)) {
265	dpavlin	285	$log->logwarn("can't open database $arg->{path}, skipping...");
266			return;
267			}
268
269			unless ($size) {
270			$log->logwarn("no records in database $arg->{path}, skipping...");
271			return;
272			}
273
274	dpavlin	339	my $from_rec = 1;
275			my $to_rec = $size;
276	dpavlin	285
277	dpavlin	286	if (my $s = $self->{offset}) {
278	dpavlin	513	$log->debug("skipping to MFN $s");
279	dpavlin	339	$from_rec = $s;
280	dpavlin	285	} else {
281	dpavlin	339	$self->{offset} = $from_rec;
282	dpavlin	285	}
283
284	dpavlin	286	if ($self->{limit}) {
285	dpavlin	301	$log->debug("limiting to ",$self->{limit}," records");
286	dpavlin	339	$to_rec = $from_rec + $self->{limit} - 1;
287			$to_rec = $size if ($to_rec > $size);
288	dpavlin	285	}
289
290			# store size for later
291	dpavlin	339	$self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
292	dpavlin	285
293	dpavlin	585	$log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
294	dpavlin	285
295			# read database
296	dpavlin	339	for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
297	dpavlin	285
298	dpavlin	286	$log->debug("position: $pos\n");
299	dpavlin	285
300	dpavlin	619	my $rec = $self->{fetch_rec}->($self, $db, $pos, sub {
301			my ($l,$f_nr) = @_;
302			return unless defined($l);
303			return $l unless ($rec_regex && $f_nr);
304	dpavlin	285
305	dpavlin	619	# apply regexps
306			if ($rec_regex && defined($rec_regex->{$f_nr})) {
307			$log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
308			my $c = 0;
309			foreach my $r (@{ $rec_regex->{$f_nr} }) {
310			#$log->debug("\$l = $l\neval \$l =~ $r");
311			eval '$l =~ ' . $r;
312			$log->error("error applying regex: $r") if ($@);
313			}
314			}
315
316			return $l;
317			});
318
319	dpavlin	308	$log->debug(sub { Dumper($rec) });
320
321	dpavlin	285	if (! $rec) {
322	dpavlin	286	$log->warn("record $pos empty? skipping...");
323	dpavlin	285	next;
324			}
325
326			# store
327	dpavlin	286	if ($self->{low_mem}) {
328			$self->{db}->put($pos, $rec);
329	dpavlin	285	} else {
330	dpavlin	286	$self->{data}->{$pos} = $rec;
331	dpavlin	285	}
332
333			# create lookup
334	dpavlin	585	$arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
335	dpavlin	285
336	dpavlin	506	# update counters for statistics
337			if ($self->{stats}) {
338	dpavlin	593
339	dpavlin	619	# fetch clean record with regexpes applied for statistics
340			my $rec = $self->{fetch_rec}->($self, $db, $pos);
341
342	dpavlin	593	foreach my $fld (keys %{ $rec }) {
343	dpavlin	506	$self->{_stats}->{fld}->{ $fld }++;
344	dpavlin	593
345			$log->logdie("invalid record fild $fld, not ARRAY")
346			unless (ref($rec->{ $fld }) eq 'ARRAY');
347
348			foreach my $row (@{ $rec->{$fld} }) {
349
350			if (ref($row) eq 'HASH') {
351
352			foreach my $sf (keys %{ $row }) {
353	dpavlin	619	next if ($sf eq 'subfields');
354	dpavlin	593	$self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
355			$self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
356			if (ref($row->{$sf}) eq 'ARRAY');
357	dpavlin	506	}
358	dpavlin	593
359			} else {
360			$self->{_stats}->{repeatable}->{ $fld }++;
361			}
362	dpavlin	506	}
363	dpavlin	593	}
364	dpavlin	506	}
365
366	dpavlin	483	$self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
367	dpavlin	285
368			}
369
370	dpavlin	286	$self->{pos} = -1;
371			$self->{last_pcnt} = 0;
372	dpavlin	285
373			# store max mfn and return it.
374	dpavlin	339	$self->{max_pos} = $to_rec;
375			$log->debug("max_pos: $to_rec");
376	dpavlin	285
377			return $size;
378			}
379
380			=head2 fetch
381
382			Fetch next record from database. It will also displays progress bar.
383
384			my $rec = $isis->fetch;
385
386			Record from this function should probably go to C<data_structure> for
387			normalisation.
388
389			=cut
390
391			sub fetch {
392			my $self = shift;
393
394			my $log = $self->_get_logger();
395
396	dpavlin	286	$log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
397	dpavlin	285
398	dpavlin	286	if ($self->{pos} == -1) {
399			$self->{pos} = $self->{offset};
400	dpavlin	285	} else {
401	dpavlin	286	$self->{pos}++;
402	dpavlin	285	}
403
404	dpavlin	286	my $mfn = $self->{pos};
405	dpavlin	285
406	dpavlin	286	if ($mfn > $self->{max_pos}) {
407			$self->{pos} = $self->{max_pos};
408	dpavlin	285	$log->debug("at EOF");
409			return;
410			}
411
412	dpavlin	483	$self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
413	dpavlin	285
414			my $rec;
415
416	dpavlin	286	if ($self->{low_mem}) {
417			$rec = $self->{db}->get($mfn);
418	dpavlin	285	} else {
419	dpavlin	286	$rec = $self->{data}->{$mfn};
420	dpavlin	285	}
421
422			$rec \|\|= 0E0;
423			}
424
425			=head2 pos
426
427			Returns current record number (MFN).
428
429			print $isis->pos;
430
431			First record in database has position 1.
432
433			=cut
434
435			sub pos {
436			my $self = shift;
437	dpavlin	286	return $self->{pos};
438	dpavlin	285	}
439
440
441			=head2 size
442
443			Returns number of records in database
444
445			print $isis->size;
446
447			Result from this function can be used to loop through all records
448
449			foreach my $mfn ( 1 ... $isis->size ) { ... }
450
451	dpavlin	286	because it takes into account C<offset> and C<limit>.
452	dpavlin	285
453			=cut
454
455			sub size {
456			my $self = shift;
457	dpavlin	286	return $self->{size};
458	dpavlin	285	}
459
460			=head2 seek
461
462			Seek to specified MFN in file.
463
464			$isis->seek(42);
465
466			First record in database has position 1.
467
468			=cut
469
470			sub seek {
471			my $self = shift;
472			my $pos = shift \|\| return;
473
474			my $log = $self->_get_logger();
475
476			if ($pos < 1) {
477			$log->warn("seek before first record");
478			$pos = 1;
479	dpavlin	286	} elsif ($pos > $self->{max_pos}) {
480	dpavlin	285	$log->warn("seek beyond last record");
481	dpavlin	286	$pos = $self->{max_pos};
482	dpavlin	285	}
483
484	dpavlin	286	return $self->{pos} = (($pos - 1) \|\| -1);
485	dpavlin	285	}
486
487	dpavlin	506	=head2 stats
488	dpavlin	285
489	dpavlin	506	Dump statistics about field and subfield usage
490
491	dpavlin	507	print $input->stats;
492	dpavlin	506
493			=cut
494
495			sub stats {
496			my $self = shift;
497	dpavlin	507
498			my $log = $self->_get_logger();
499
500			my $s = $self->{_stats};
501			if (! $s) {
502			$log->warn("called stats, but there is no statistics collected");
503			return;
504			}
505
506			my $max_fld = 0;
507
508			my $out = join("\n",
509			map {
510			my $f = $_ \|\| die "no field";
511			my $v = $s->{fld}->{$f} \|\| die "no s->{fld}->{$f}";
512			$max_fld = $v if ($v > $max_fld);
513
514	dpavlin	519	my $o = sprintf("%4s %d ~", $f, $v);
515	dpavlin	507
516			if (defined($s->{sf}->{$f})) {
517			map {
518	dpavlin	593	$o .= sprintf(" %s:%d%s", $_,
519			$s->{sf}->{$f}->{$_}->{count},
520			$s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
521			);
522	dpavlin	507	} sort keys %{ $s->{sf}->{$f} };
523			}
524
525			if (my $v_r = $s->{repeatable}->{$f}) {
526			$o .= " ($v_r)" if ($v_r != $v);
527			}
528
529			$o;
530	dpavlin	519	} sort { $a cmp $b } keys %{ $s->{fld} }
531	dpavlin	507	);
532
533			$log->debug( sub { Dumper($s) } );
534
535			return $out;
536	dpavlin	506	}
537
538	dpavlin	598	=head2 modify_record_regexps
539	dpavlin	597
540			Generate hash with regexpes to be applied using L<filter>.
541
542			my $regexpes = $input->modify_record_regexps(
543			900 => { '^a' => { ' : ' => '^b' } },
544			901 => { '*' => { '^b' => ' ; ' } },
545			);
546
547			=cut
548
549			sub modify_record_regexps {
550			my $self = shift;
551			my $modify_record = {@_};
552
553			my $regexpes;
554
555			foreach my $f (keys %$modify_record) {
556			warn "--- f: $f\n";
557			foreach my $sf (keys %{ $modify_record->{$f} }) {
558			warn "---- sf: $sf\n";
559			foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
560			my $to = $modify_record->{$f}->{$sf}->{$from};
561			#die "no field?" unless defined($to);
562			warn "----- transform: \|$from\| -> \|$to\|\n";
563
564			if ($sf =~ /^\^/) {
565			my $regex =
566			's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
567			push @{ $regexpes->{$f} }, $regex;
568			warn ">>>>> $regex [sf]\n";
569			} else {
570			my $regex =
571			's/\Q'. $from .'\E/'. $to .'/g';
572			push @{ $regexpes->{$f} }, $regex;
573			warn ">>>>> $regex [global]\n";
574			}
575
576			}
577			}
578			}
579
580			return $regexpes;
581			}
582
583	dpavlin	3	=head1 MEMORY USAGE
584	dpavlin	1
585	dpavlin	3	C<low_mem> options is double-edged sword. If enabled, WebPAC
586			will run on memory constraint machines (which doesn't have enough
587			physical RAM to create memory structure for whole source database).
588	dpavlin	1
589	dpavlin	3	If your machine has 512Mb or more of RAM and database is around 10000 records,
590			memory shouldn't be an issue. If you don't have enough physical RAM, you
591			might consider using virtual memory (if your operating system is handling it
592			well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
593			parsed structure of ISIS database (this is what C<low_mem> option does).
594	dpavlin	1
595	dpavlin	3	Hitting swap at end of reading source database is probably o.k. However,
596			hitting swap before 90% will dramatically decrease performance and you will
597			be better off with C<low_mem> and using rest of availble memory for
598			operating system disk cache (Linux is particuallary good about this).
599			However, every access to database record will require disk access, so
600			generation phase will be slower 10-100 times.
601
602			Parsed structures are essential - you just have option to trade RAM memory
603			(which is fast) for disk space (which is slow). Be sure to have planty of
604			disk space if you are using C<low_mem> and thus L<DBM::Deep>.
605
606			However, when WebPAC is running on desktop machines (or laptops :-), it's
607			highly undesireable for system to start swapping. Using C<low_mem> option can
608			reduce WecPAC memory usage to around 64Mb for same database with lookup
609			fields and sorted indexes which stay in RAM. Performance will suffer, but
610			memory usage will really be minimal. It might be also more confortable to
611			run WebPAC reniced on those machines.
612
613
614			=head1 AUTHOR
615
616			Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
617
618	dpavlin	1	=head1 COPYRIGHT & LICENSE
619
620	dpavlin	599	Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
621	dpavlin	1
622			This program is free software; you can redistribute it and/or modify it
623			under the same terms as Perl itself.
624
625			=cut
626
627			1; # End of WebPAC::Input