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 0.10

=cut

our $VERSION = '0.10';

=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 $l unless ($rec_regex && $f_nr);

#                               my $max_regex = 100;

                                # 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: $r") if ($@);

#                                               while ( $c < $max_regex && eval '$l =~ ' . $r ) { $c++ };
#                                               $log->error("field $f_nr has more than $max_regex regex iterations\n\$l = $l\neval \$l =~ $r") if ($c == $max_regex);

                                        }
                                }

                                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 );

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

                        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 }) {
                                                        $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	613	Version 0.10
20	dpavlin	1
21			=cut
22
23	dpavlin	613	our $VERSION = '0.10';
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 && $recode_map);
254
255	dpavlin	599	## FIXME remove this warning when we are sure that none of API is calling
256			## this wrongly
257	dpavlin	606	#warn "filter called without field number" unless ($f_nr);
258	dpavlin	597
259	dpavlin	599	return $l unless ($rec_regex && $f_nr);
260
261	dpavlin	613	# my $max_regex = 100;
262
263	dpavlin	597	# apply regexps
264			if ($rec_regex && defined($rec_regex->{$f_nr})) {
265			$log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
266			my $c = 0;
267			foreach my $r (@{ $rec_regex->{$f_nr} }) {
268	dpavlin	613	#$log->debug("\$l = $l\neval \$l =~ $r");
269			eval '$l =~ ' . $r;
270			$log->error("error applying regex: $r") if ($@);
271
272			# while ( $c < $max_regex && eval '$l =~ ' . $r ) { $c++ };
273			# $log->error("field $f_nr has more than $max_regex regex iterations\n\$l = $l\neval \$l =~ $r") if ($c == $max_regex);
274
275	dpavlin	597	}
276			}
277
278			return $l;
279			},
280	dpavlin	523	%{ $arg },
281	dpavlin	285	);
282
283	dpavlin	496	unless (defined($db)) {
284	dpavlin	285	$log->logwarn("can't open database $arg->{path}, skipping...");
285			return;
286			}
287
288			unless ($size) {
289			$log->logwarn("no records in database $arg->{path}, skipping...");
290			return;
291			}
292
293	dpavlin	339	my $from_rec = 1;
294			my $to_rec = $size;
295	dpavlin	285
296	dpavlin	286	if (my $s = $self->{offset}) {
297	dpavlin	513	$log->debug("skipping to MFN $s");
298	dpavlin	339	$from_rec = $s;
299	dpavlin	285	} else {
300	dpavlin	339	$self->{offset} = $from_rec;
301	dpavlin	285	}
302
303	dpavlin	286	if ($self->{limit}) {
304	dpavlin	301	$log->debug("limiting to ",$self->{limit}," records");
305	dpavlin	339	$to_rec = $from_rec + $self->{limit} - 1;
306			$to_rec = $size if ($to_rec > $size);
307	dpavlin	285	}
308
309			# store size for later
310	dpavlin	339	$self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
311	dpavlin	285
312	dpavlin	585	$log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
313	dpavlin	285
314			# read database
315	dpavlin	339	for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
316	dpavlin	285
317	dpavlin	286	$log->debug("position: $pos\n");
318	dpavlin	285
319	dpavlin	289	my $rec = $self->{fetch_rec}->($self, $db, $pos );
320	dpavlin	285
321	dpavlin	308	$log->debug(sub { Dumper($rec) });
322
323	dpavlin	285	if (! $rec) {
324	dpavlin	286	$log->warn("record $pos empty? skipping...");
325	dpavlin	285	next;
326			}
327
328			# store
329	dpavlin	286	if ($self->{low_mem}) {
330			$self->{db}->put($pos, $rec);
331	dpavlin	285	} else {
332	dpavlin	286	$self->{data}->{$pos} = $rec;
333	dpavlin	285	}
334
335			# create lookup
336	dpavlin	585	$arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
337	dpavlin	285
338	dpavlin	506	# update counters for statistics
339			if ($self->{stats}) {
340	dpavlin	593
341			foreach my $fld (keys %{ $rec }) {
342	dpavlin	506	$self->{_stats}->{fld}->{ $fld }++;
343	dpavlin	593
344			$log->logdie("invalid record fild $fld, not ARRAY")
345			unless (ref($rec->{ $fld }) eq 'ARRAY');
346
347			foreach my $row (@{ $rec->{$fld} }) {
348
349			if (ref($row) eq 'HASH') {
350
351			foreach my $sf (keys %{ $row }) {
352			$self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
353			$self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
354			if (ref($row->{$sf}) eq 'ARRAY');
355	dpavlin	506	}
356	dpavlin	593
357			} else {
358			$self->{_stats}->{repeatable}->{ $fld }++;
359			}
360	dpavlin	506	}
361	dpavlin	593	}
362	dpavlin	506	}
363
364	dpavlin	483	$self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
365	dpavlin	285
366			}
367
368	dpavlin	286	$self->{pos} = -1;
369			$self->{last_pcnt} = 0;
370	dpavlin	285
371			# store max mfn and return it.
372	dpavlin	339	$self->{max_pos} = $to_rec;
373			$log->debug("max_pos: $to_rec");
374	dpavlin	285
375			return $size;
376			}
377
378			=head2 fetch
379
380			Fetch next record from database. It will also displays progress bar.
381
382			my $rec = $isis->fetch;
383
384			Record from this function should probably go to C<data_structure> for
385			normalisation.
386
387			=cut
388
389			sub fetch {
390			my $self = shift;
391
392			my $log = $self->_get_logger();
393
394	dpavlin	286	$log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
395	dpavlin	285
396	dpavlin	286	if ($self->{pos} == -1) {
397			$self->{pos} = $self->{offset};
398	dpavlin	285	} else {
399	dpavlin	286	$self->{pos}++;
400	dpavlin	285	}
401
402	dpavlin	286	my $mfn = $self->{pos};
403	dpavlin	285
404	dpavlin	286	if ($mfn > $self->{max_pos}) {
405			$self->{pos} = $self->{max_pos};
406	dpavlin	285	$log->debug("at EOF");
407			return;
408			}
409
410	dpavlin	483	$self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
411	dpavlin	285
412			my $rec;
413
414	dpavlin	286	if ($self->{low_mem}) {
415			$rec = $self->{db}->get($mfn);
416	dpavlin	285	} else {
417	dpavlin	286	$rec = $self->{data}->{$mfn};
418	dpavlin	285	}
419
420			$rec \|\|= 0E0;
421			}
422
423			=head2 pos
424
425			Returns current record number (MFN).
426
427			print $isis->pos;
428
429			First record in database has position 1.
430
431			=cut
432
433			sub pos {
434			my $self = shift;
435	dpavlin	286	return $self->{pos};
436	dpavlin	285	}
437
438
439			=head2 size
440
441			Returns number of records in database
442
443			print $isis->size;
444
445			Result from this function can be used to loop through all records
446
447			foreach my $mfn ( 1 ... $isis->size ) { ... }
448
449	dpavlin	286	because it takes into account C<offset> and C<limit>.
450	dpavlin	285
451			=cut
452
453			sub size {
454			my $self = shift;
455	dpavlin	286	return $self->{size};
456	dpavlin	285	}
457
458			=head2 seek
459
460			Seek to specified MFN in file.
461
462			$isis->seek(42);
463
464			First record in database has position 1.
465
466			=cut
467
468			sub seek {
469			my $self = shift;
470			my $pos = shift \|\| return;
471
472			my $log = $self->_get_logger();
473
474			if ($pos < 1) {
475			$log->warn("seek before first record");
476			$pos = 1;
477	dpavlin	286	} elsif ($pos > $self->{max_pos}) {
478	dpavlin	285	$log->warn("seek beyond last record");
479	dpavlin	286	$pos = $self->{max_pos};
480	dpavlin	285	}
481
482	dpavlin	286	return $self->{pos} = (($pos - 1) \|\| -1);
483	dpavlin	285	}
484
485	dpavlin	506	=head2 stats
486	dpavlin	285
487	dpavlin	506	Dump statistics about field and subfield usage
488
489	dpavlin	507	print $input->stats;
490	dpavlin	506
491			=cut
492
493			sub stats {
494			my $self = shift;
495	dpavlin	507
496			my $log = $self->_get_logger();
497
498			my $s = $self->{_stats};
499			if (! $s) {
500			$log->warn("called stats, but there is no statistics collected");
501			return;
502			}
503
504			my $max_fld = 0;
505
506			my $out = join("\n",
507			map {
508			my $f = $_ \|\| die "no field";
509			my $v = $s->{fld}->{$f} \|\| die "no s->{fld}->{$f}";
510			$max_fld = $v if ($v > $max_fld);
511
512	dpavlin	519	my $o = sprintf("%4s %d ~", $f, $v);
513	dpavlin	507
514			if (defined($s->{sf}->{$f})) {
515			map {
516	dpavlin	593	$o .= sprintf(" %s:%d%s", $_,
517			$s->{sf}->{$f}->{$_}->{count},
518			$s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
519			);
520	dpavlin	507	} sort keys %{ $s->{sf}->{$f} };
521			}
522
523			if (my $v_r = $s->{repeatable}->{$f}) {
524			$o .= " ($v_r)" if ($v_r != $v);
525			}
526
527			$o;
528	dpavlin	519	} sort { $a cmp $b } keys %{ $s->{fld} }
529	dpavlin	507	);
530
531			$log->debug( sub { Dumper($s) } );
532
533			return $out;
534	dpavlin	506	}
535
536	dpavlin	598	=head2 modify_record_regexps
537	dpavlin	597
538			Generate hash with regexpes to be applied using L<filter>.
539
540			my $regexpes = $input->modify_record_regexps(
541			900 => { '^a' => { ' : ' => '^b' } },
542			901 => { '*' => { '^b' => ' ; ' } },
543			);
544
545			=cut
546
547			sub modify_record_regexps {
548			my $self = shift;
549			my $modify_record = {@_};
550
551			my $regexpes;
552
553			foreach my $f (keys %$modify_record) {
554			warn "--- f: $f\n";
555			foreach my $sf (keys %{ $modify_record->{$f} }) {
556			warn "---- sf: $sf\n";
557			foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
558			my $to = $modify_record->{$f}->{$sf}->{$from};
559			#die "no field?" unless defined($to);
560			warn "----- transform: \|$from\| -> \|$to\|\n";
561
562			if ($sf =~ /^\^/) {
563			my $regex =
564			's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
565			push @{ $regexpes->{$f} }, $regex;
566			warn ">>>>> $regex [sf]\n";
567			} else {
568			my $regex =
569			's/\Q'. $from .'\E/'. $to .'/g';
570			push @{ $regexpes->{$f} }, $regex;
571			warn ">>>>> $regex [global]\n";
572			}
573
574			}
575			}
576			}
577
578			return $regexpes;
579			}
580
581	dpavlin	3	=head1 MEMORY USAGE
582	dpavlin	1
583	dpavlin	3	C<low_mem> options is double-edged sword. If enabled, WebPAC
584			will run on memory constraint machines (which doesn't have enough
585			physical RAM to create memory structure for whole source database).
586	dpavlin	1
587	dpavlin	3	If your machine has 512Mb or more of RAM and database is around 10000 records,
588			memory shouldn't be an issue. If you don't have enough physical RAM, you
589			might consider using virtual memory (if your operating system is handling it
590			well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
591			parsed structure of ISIS database (this is what C<low_mem> option does).
592	dpavlin	1
593	dpavlin	3	Hitting swap at end of reading source database is probably o.k. However,
594			hitting swap before 90% will dramatically decrease performance and you will
595			be better off with C<low_mem> and using rest of availble memory for
596			operating system disk cache (Linux is particuallary good about this).
597			However, every access to database record will require disk access, so
598			generation phase will be slower 10-100 times.
599
600			Parsed structures are essential - you just have option to trade RAM memory
601			(which is fast) for disk space (which is slow). Be sure to have planty of
602			disk space if you are using C<low_mem> and thus L<DBM::Deep>.
603
604			However, when WebPAC is running on desktop machines (or laptops :-), it's
605			highly undesireable for system to start swapping. Using C<low_mem> option can
606			reduce WecPAC memory usage to around 64Mb for same database with lookup
607			fields and sorted indexes which stay in RAM. Performance will suffer, but
608			memory usage will really be minimal. It might be also more confortable to
609			run WebPAC reniced on those machines.
610
611
612			=head1 AUTHOR
613
614			Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
615
616	dpavlin	1	=head1 COPYRIGHT & LICENSE
617
618	dpavlin	599	Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
619	dpavlin	1
620			This program is free software; you can redistribute it and/or modify it
621			under the same terms as Perl itself.
622
623			=cut
624
625			1; # End of WebPAC::Input