9 use base qw/WebPAC::Common/;
15 WebPAC::Input - read different file formats into WebPAC
23 our $VERSION = '0.09';
27 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>.
31 Simply, something that is indexed by unmber from 1 .. I<size>.
33 Examples of such databases are CDS/ISIS files, MARC files, lines in
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.
40 Perhaps a little code snippet.
44 my $db = WebPAC::Input->new(
45 module => 'WebPAC::Input::ISIS',
49 $db->open( path => '/path/to/database' );
50 print "database size: ",$db->size,"\n";
51 while (my $rec = $db->fetch) {
52 # do something with $rec
61 Create new input database object.
63 my $db = new WebPAC::Input(
64 module => 'WebPAC::Input::MARC',
65 encoding => 'ISO-8859-2',
67 recode => 'char pairs',
71 C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
72 L<WebPAC::Input::MARC>.
74 Optional parametar C<encoding> specify application code page (which will be
75 used internally). This should probably be your terminal encoding, and by
76 default, it C<ISO-8859-2>.
78 Default is not to use C<low_mem> options (see L<MEMORY USAGE> below).
80 C<recode> is optional string constisting of character or words pairs that
81 should be replaced in input stream.
83 C<no_progress_bar> disables progress bar output on C<STDOUT>
85 This function will also call low-level C<init> if it exists with same
95 my $log = $self->_get_logger;
97 $log->logconfess("code_page argument is not suppored any more. change it to encoding") if ($self->{lookup});
98 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_ref") if ($self->{lookup});
100 $log->logconfess("specify low-level file format module") unless ($self->{module});
101 my $module = $self->{module};
104 $log->debug("require low-level module $self->{module} from $module");
107 #eval $self->{module} .'->import';
109 # check if required subclasses are implemented
110 foreach my $subclass (qw/open_db fetch_rec init/) {
111 my $n = $self->{module} . '::' . $subclass;
112 if (! defined &{ $n }) {
113 my $missing = "missing $subclass in $self->{module}";
114 $self->{$subclass} = sub { $log->logwarn($missing) };
116 $self->{$subclass} = \&{ $n };
121 $log->debug("calling init");
122 $self->{init}->($self, @_);
125 $self->{'encoding'} ||= 'ISO-8859-2';
127 # running with low_mem flag? well, use DBM::Deep then.
128 if ($self->{'low_mem'}) {
129 $log->info("running with low_mem which impacts performance (<32 Mb memory usage)");
131 my $db_file = "data.db";
134 unlink $db_file or $log->logdie("can't remove '$db_file' from last run");
135 $log->debug("removed '$db_file' from last run");
140 my $db = new DBM::Deep $db_file;
142 $log->logdie("DBM::Deep error: $!") unless ($db);
145 $log->logdie("can't open '$db_file' under low_mem: ",$db->error());
147 $log->debug("using file '$db_file' for DBM::Deep");
153 $self ? return $self : return undef;
158 This function will read whole database in memory and produce lookups.
161 path => '/path/to/database/file',
165 lookup => $lookup_obj,
169 # store lookup $k => $v
172 900 => { '^a' => { ' : ' => '^b' } },
173 901 => { '*' => { '^b' => ' ; ' } },
177 By default, C<code_page> is assumed to be C<852>.
179 C<offset> is optional parametar to position at some offset before reading from database.
181 C<limit> is optional parametar to read just C<limit> records from database
183 C<stats> create optional report about usage of fields and subfields
185 C<lookup_coderef> is closure to call when adding C<< key => 'value' >> combinations to
188 C<modify_records> specify mapping from subfields to delimiters or from
189 delimiters to subfields, as well as oprations on fields (if subfield is
192 Returns size of database, regardless of C<offset> and C<limit>
193 parametars, see also C<size>.
201 my $log = $self->_get_logger();
203 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_coderef") if ($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');
207 $log->logcroak("need path") if (! $arg->{'path'});
208 my $code_page = $arg->{'code_page'} || '852';
210 # store data in object
211 $self->{'input_code_page'} = $code_page;
212 foreach my $v (qw/path offset limit/) {
213 $self->{$v} = $arg->{$v} if ($arg->{$v});
216 # create Text::Iconv object
217 $self->{iconv} = Text::Iconv->new($code_page,$self->{'encoding'}); ## FIXME remove!
223 if ($self->{recode}) {
224 my @r = split(/\s/, $self->{recode});
226 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
231 $recode_map->{$from} = $to;
234 $recode_regex = join '|' => keys %{ $recode_map };
236 $log->debug("using recode regex: $recode_regex");
241 my $rec_regex = $self->modify_record_regexps(%{ $arg->{modify_records} });
242 $log->debug("rec_regex: ", Dumper($rec_regex));
244 my ($db, $size) = $self->{open_db}->( $self,
245 path => $arg->{path},
248 return unless defined($l);
250 ## FIXME remove iconv!
251 $l = $self->{iconv}->convert($l) if ($self->{iconv});
253 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
255 ## FIXME remove this warning when we are sure that none of API is calling
257 #warn "filter called without field number" unless ($f_nr);
259 return $l unless ($rec_regex && $f_nr);
262 if ($rec_regex && defined($rec_regex->{$f_nr})) {
263 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
265 foreach my $r (@{ $rec_regex->{$f_nr} }) {
266 while ( eval '$l =~ ' . $r ) { $c++ };
268 warn "## field $f_nr triggered $c regexpes\n" if ($c && $self->{debug});
276 unless (defined($db)) {
277 $log->logwarn("can't open database $arg->{path}, skipping...");
282 $log->logwarn("no records in database $arg->{path}, skipping...");
289 if (my $s = $self->{offset}) {
290 $log->debug("skipping to MFN $s");
293 $self->{offset} = $from_rec;
296 if ($self->{limit}) {
297 $log->debug("limiting to ",$self->{limit}," records");
298 $to_rec = $from_rec + $self->{limit} - 1;
299 $to_rec = $size if ($to_rec > $size);
302 # store size for later
303 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
305 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
308 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
310 $log->debug("position: $pos\n");
312 my $rec = $self->{fetch_rec}->($self, $db, $pos );
314 $log->debug(sub { Dumper($rec) });
317 $log->warn("record $pos empty? skipping...");
322 if ($self->{low_mem}) {
323 $self->{db}->put($pos, $rec);
325 $self->{data}->{$pos} = $rec;
329 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
331 # update counters for statistics
332 if ($self->{stats}) {
334 foreach my $fld (keys %{ $rec }) {
335 $self->{_stats}->{fld}->{ $fld }++;
337 $log->logdie("invalid record fild $fld, not ARRAY")
338 unless (ref($rec->{ $fld }) eq 'ARRAY');
340 foreach my $row (@{ $rec->{$fld} }) {
342 if (ref($row) eq 'HASH') {
344 foreach my $sf (keys %{ $row }) {
345 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
346 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
347 if (ref($row->{$sf}) eq 'ARRAY');
351 $self->{_stats}->{repeatable}->{ $fld }++;
357 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
362 $self->{last_pcnt} = 0;
364 # store max mfn and return it.
365 $self->{max_pos} = $to_rec;
366 $log->debug("max_pos: $to_rec");
373 Fetch next record from database. It will also displays progress bar.
375 my $rec = $isis->fetch;
377 Record from this function should probably go to C<data_structure> for
385 my $log = $self->_get_logger();
387 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
389 if ($self->{pos} == -1) {
390 $self->{pos} = $self->{offset};
395 my $mfn = $self->{pos};
397 if ($mfn > $self->{max_pos}) {
398 $self->{pos} = $self->{max_pos};
399 $log->debug("at EOF");
403 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
407 if ($self->{low_mem}) {
408 $rec = $self->{db}->get($mfn);
410 $rec = $self->{data}->{$mfn};
418 Returns current record number (MFN).
422 First record in database has position 1.
434 Returns number of records in database
438 Result from this function can be used to loop through all records
440 foreach my $mfn ( 1 ... $isis->size ) { ... }
442 because it takes into account C<offset> and C<limit>.
448 return $self->{size};
453 Seek to specified MFN in file.
457 First record in database has position 1.
463 my $pos = shift || return;
465 my $log = $self->_get_logger();
468 $log->warn("seek before first record");
470 } elsif ($pos > $self->{max_pos}) {
471 $log->warn("seek beyond last record");
472 $pos = $self->{max_pos};
475 return $self->{pos} = (($pos - 1) || -1);
480 Dump statistics about field and subfield usage
489 my $log = $self->_get_logger();
491 my $s = $self->{_stats};
493 $log->warn("called stats, but there is no statistics collected");
501 my $f = $_ || die "no field";
502 my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
503 $max_fld = $v if ($v > $max_fld);
505 my $o = sprintf("%4s %d ~", $f, $v);
507 if (defined($s->{sf}->{$f})) {
509 $o .= sprintf(" %s:%d%s", $_,
510 $s->{sf}->{$f}->{$_}->{count},
511 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
513 } sort keys %{ $s->{sf}->{$f} };
516 if (my $v_r = $s->{repeatable}->{$f}) {
517 $o .= " ($v_r)" if ($v_r != $v);
521 } sort { $a cmp $b } keys %{ $s->{fld} }
524 $log->debug( sub { Dumper($s) } );
529 =head2 modify_record_regexps
531 Generate hash with regexpes to be applied using L<filter>.
533 my $regexpes = $input->modify_record_regexps(
534 900 => { '^a' => { ' : ' => '^b' } },
535 901 => { '*' => { '^b' => ' ; ' } },
540 sub modify_record_regexps {
542 my $modify_record = {@_};
546 foreach my $f (keys %$modify_record) {
548 foreach my $sf (keys %{ $modify_record->{$f} }) {
549 warn "---- sf: $sf\n";
550 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
551 my $to = $modify_record->{$f}->{$sf}->{$from};
552 #die "no field?" unless defined($to);
553 warn "----- transform: |$from| -> |$to|\n";
557 's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
558 push @{ $regexpes->{$f} }, $regex;
559 warn ">>>>> $regex [sf]\n";
562 's/\Q'. $from .'\E/'. $to .'/g';
563 push @{ $regexpes->{$f} }, $regex;
564 warn ">>>>> $regex [global]\n";
576 C<low_mem> options is double-edged sword. If enabled, WebPAC
577 will run on memory constraint machines (which doesn't have enough
578 physical RAM to create memory structure for whole source database).
580 If your machine has 512Mb or more of RAM and database is around 10000 records,
581 memory shouldn't be an issue. If you don't have enough physical RAM, you
582 might consider using virtual memory (if your operating system is handling it
583 well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
584 parsed structure of ISIS database (this is what C<low_mem> option does).
586 Hitting swap at end of reading source database is probably o.k. However,
587 hitting swap before 90% will dramatically decrease performance and you will
588 be better off with C<low_mem> and using rest of availble memory for
589 operating system disk cache (Linux is particuallary good about this).
590 However, every access to database record will require disk access, so
591 generation phase will be slower 10-100 times.
593 Parsed structures are essential - you just have option to trade RAM memory
594 (which is fast) for disk space (which is slow). Be sure to have planty of
595 disk space if you are using C<low_mem> and thus L<DBM::Deep>.
597 However, when WebPAC is running on desktop machines (or laptops :-), it's
598 highly undesireable for system to start swapping. Using C<low_mem> option can
599 reduce WecPAC memory usage to around 64Mb for same database with lookup
600 fields and sorted indexes which stay in RAM. Performance will suffer, but
601 memory usage will really be minimal. It might be also more confortable to
602 run WebPAC reniced on those machines.
607 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
609 =head1 COPYRIGHT & LICENSE
611 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
613 This program is free software; you can redistribute it and/or modify it
614 under the same terms as Perl itself.
618 1; # End of WebPAC::Input