9 use base qw/WebPAC::Common/;
15 WebPAC::Input - read different file formats into WebPAC
23 our $VERSION = '0.08';
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 return $l unless ($rec_regex);
258 if ($rec_regex && defined($rec_regex->{$f_nr})) {
259 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
261 foreach my $r (@{ $rec_regex->{$f_nr} }) {
262 while ( eval '$l =~ ' . $r ) { $c++ };
264 warn "## field $f_nr triggered $c regexpes\n" if ($c && $self->{debug});
272 unless (defined($db)) {
273 $log->logwarn("can't open database $arg->{path}, skipping...");
278 $log->logwarn("no records in database $arg->{path}, skipping...");
285 if (my $s = $self->{offset}) {
286 $log->debug("skipping to MFN $s");
289 $self->{offset} = $from_rec;
292 if ($self->{limit}) {
293 $log->debug("limiting to ",$self->{limit}," records");
294 $to_rec = $from_rec + $self->{limit} - 1;
295 $to_rec = $size if ($to_rec > $size);
298 # store size for later
299 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
301 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
304 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
306 $log->debug("position: $pos\n");
308 my $rec = $self->{fetch_rec}->($self, $db, $pos );
310 $log->debug(sub { Dumper($rec) });
313 $log->warn("record $pos empty? skipping...");
318 if ($self->{low_mem}) {
319 $self->{db}->put($pos, $rec);
321 $self->{data}->{$pos} = $rec;
325 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
327 # update counters for statistics
328 if ($self->{stats}) {
330 foreach my $fld (keys %{ $rec }) {
331 $self->{_stats}->{fld}->{ $fld }++;
333 $log->logdie("invalid record fild $fld, not ARRAY")
334 unless (ref($rec->{ $fld }) eq 'ARRAY');
336 foreach my $row (@{ $rec->{$fld} }) {
338 if (ref($row) eq 'HASH') {
340 foreach my $sf (keys %{ $row }) {
341 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
342 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
343 if (ref($row->{$sf}) eq 'ARRAY');
347 $self->{_stats}->{repeatable}->{ $fld }++;
353 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
358 $self->{last_pcnt} = 0;
360 # store max mfn and return it.
361 $self->{max_pos} = $to_rec;
362 $log->debug("max_pos: $to_rec");
369 Fetch next record from database. It will also displays progress bar.
371 my $rec = $isis->fetch;
373 Record from this function should probably go to C<data_structure> for
381 my $log = $self->_get_logger();
383 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
385 if ($self->{pos} == -1) {
386 $self->{pos} = $self->{offset};
391 my $mfn = $self->{pos};
393 if ($mfn > $self->{max_pos}) {
394 $self->{pos} = $self->{max_pos};
395 $log->debug("at EOF");
399 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
403 if ($self->{low_mem}) {
404 $rec = $self->{db}->get($mfn);
406 $rec = $self->{data}->{$mfn};
414 Returns current record number (MFN).
418 First record in database has position 1.
430 Returns number of records in database
434 Result from this function can be used to loop through all records
436 foreach my $mfn ( 1 ... $isis->size ) { ... }
438 because it takes into account C<offset> and C<limit>.
444 return $self->{size};
449 Seek to specified MFN in file.
453 First record in database has position 1.
459 my $pos = shift || return;
461 my $log = $self->_get_logger();
464 $log->warn("seek before first record");
466 } elsif ($pos > $self->{max_pos}) {
467 $log->warn("seek beyond last record");
468 $pos = $self->{max_pos};
471 return $self->{pos} = (($pos - 1) || -1);
476 Dump statistics about field and subfield usage
485 my $log = $self->_get_logger();
487 my $s = $self->{_stats};
489 $log->warn("called stats, but there is no statistics collected");
497 my $f = $_ || die "no field";
498 my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
499 $max_fld = $v if ($v > $max_fld);
501 my $o = sprintf("%4s %d ~", $f, $v);
503 if (defined($s->{sf}->{$f})) {
505 $o .= sprintf(" %s:%d%s", $_,
506 $s->{sf}->{$f}->{$_}->{count},
507 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
509 } sort keys %{ $s->{sf}->{$f} };
512 if (my $v_r = $s->{repeatable}->{$f}) {
513 $o .= " ($v_r)" if ($v_r != $v);
517 } sort { $a cmp $b } keys %{ $s->{fld} }
520 $log->debug( sub { Dumper($s) } );
525 =head1 modify_record_regexps
527 Generate hash with regexpes to be applied using L<filter>.
529 my $regexpes = $input->modify_record_regexps(
530 900 => { '^a' => { ' : ' => '^b' } },
531 901 => { '*' => { '^b' => ' ; ' } },
536 sub modify_record_regexps {
538 my $modify_record = {@_};
542 foreach my $f (keys %$modify_record) {
544 foreach my $sf (keys %{ $modify_record->{$f} }) {
545 warn "---- sf: $sf\n";
546 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
547 my $to = $modify_record->{$f}->{$sf}->{$from};
548 #die "no field?" unless defined($to);
549 warn "----- transform: |$from| -> |$to|\n";
553 's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
554 push @{ $regexpes->{$f} }, $regex;
555 warn ">>>>> $regex [sf]\n";
558 's/\Q'. $from .'\E/'. $to .'/g';
559 push @{ $regexpes->{$f} }, $regex;
560 warn ">>>>> $regex [global]\n";
572 C<low_mem> options is double-edged sword. If enabled, WebPAC
573 will run on memory constraint machines (which doesn't have enough
574 physical RAM to create memory structure for whole source database).
576 If your machine has 512Mb or more of RAM and database is around 10000 records,
577 memory shouldn't be an issue. If you don't have enough physical RAM, you
578 might consider using virtual memory (if your operating system is handling it
579 well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
580 parsed structure of ISIS database (this is what C<low_mem> option does).
582 Hitting swap at end of reading source database is probably o.k. However,
583 hitting swap before 90% will dramatically decrease performance and you will
584 be better off with C<low_mem> and using rest of availble memory for
585 operating system disk cache (Linux is particuallary good about this).
586 However, every access to database record will require disk access, so
587 generation phase will be slower 10-100 times.
589 Parsed structures are essential - you just have option to trade RAM memory
590 (which is fast) for disk space (which is slow). Be sure to have planty of
591 disk space if you are using C<low_mem> and thus L<DBM::Deep>.
593 However, when WebPAC is running on desktop machines (or laptops :-), it's
594 highly undesireable for system to start swapping. Using C<low_mem> option can
595 reduce WecPAC memory usage to around 64Mb for same database with lookup
596 fields and sorted indexes which stay in RAM. Performance will suffer, but
597 memory usage will really be minimal. It might be also more confortable to
598 run WebPAC reniced on those machines.
603 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
605 =head1 COPYRIGHT & LICENSE
607 Copyright 2005 Dobrica Pavlinusic, All Rights Reserved.
609 This program is free software; you can redistribute it and/or modify it
610 under the same terms as Perl itself.
614 1; # End of WebPAC::Input