/[webpac2]/trunk/lib/WebPAC/Input.pm
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
ViewVC logotype

Contents of /trunk/lib/WebPAC/Input.pm

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1221 - (show annotations)
Tue Jun 9 21:37:32 2009 UTC (14 years, 10 months ago) by dpavlin
File size: 17481 byte(s)
accessor for low-level input_module

1 package WebPAC::Input;
2
3 use warnings;
4 use strict;
5
6 use lib 'lib';
7
8 use WebPAC::Common;
9 use base qw/WebPAC::Common/;
10 use Data::Dump qw/dump/;
11 use Encode qw/decode from_to/;
12 use YAML;
13
14 =head1 NAME
15
16 WebPAC::Input - read different file formats into WebPAC
17
18 =cut
19
20 our $VERSION = '0.19';
21
22 =head1 SYNOPSIS
23
24 This module implements input as database which have fixed and known
25 I<size> while indexing and single unique numeric identifier for database
26 position ranging from 1 to I<size>.
27
28 Simply, something that is indexed by unmber from 1 .. I<size>.
29
30 Examples of such databases are CDS/ISIS files, MARC files, lines in
31 text file, and so on.
32
33 Specific file formats are implemented using low-level interface modules,
34 located in C<WebPAC::Input::*> namespace which export C<open_db>,
35 C<fetch_rec> and optional C<init> functions.
36
37 Perhaps a little code snippet.
38
39 use WebPAC::Input;
40
41 my $db = WebPAC::Input->new(
42 module => 'WebPAC::Input::ISIS',
43 );
44
45 $db->open( path => '/path/to/database' );
46 print "database size: ",$db->size,"\n";
47 while (my $rec = $db->fetch) {
48 # do something with $rec
49 }
50
51
52
53 =head1 FUNCTIONS
54
55 =head2 new
56
57 Create new input database object.
58
59 my $db = new WebPAC::Input(
60 module => 'WebPAC::Input::MARC',
61 recode => 'char pairs',
62 no_progress_bar => 1,
63 input_config => {
64 mapping => [ 'foo', 'bar', 'baz' ],
65 },
66 );
67
68 C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
69 L<WebPAC::Input::MARC>.
70
71 C<recode> is optional string constisting of character or words pairs that
72 should be replaced in input stream.
73
74 C<no_progress_bar> disables progress bar output on C<STDOUT>
75
76 This function will also call low-level C<init> if it exists with same
77 parametars.
78
79 =cut
80
81 sub new {
82 my $class = shift;
83 my $self = {@_};
84 bless($self, $class);
85
86 my $log = $self->_get_logger;
87
88 $log->logconfess("code_page argument is not suppored any more.") if $self->{code_page};
89 $log->logconfess("encoding argument is not suppored any more.") if $self->{encoding};
90 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_ref") if $self->{lookup};
91 $log->logconfess("low_mem argument is not suppored any more. rewrite it to load_row and save_row") if $self->{low_mem};
92
93 $log->logconfess("specify low-level file format module") unless ($self->{module});
94 my $module_path = $self->{module};
95 $module_path =~ s#::#/#g;
96 $module_path .= '.pm';
97 $log->debug("require low-level module $self->{module} from $module_path");
98
99 require $module_path;
100
101 $self ? return $self : return undef;
102 }
103
104 =head2 open
105
106 This function will read whole database in memory and produce lookups.
107
108 my $store; # simple in-memory hash
109
110 $input->open(
111 path => '/path/to/database/file',
112 input_encoding => 'cp852',
113 strict_encoding => 0,
114 limit => 500,
115 offset => 6000,
116 stats => 1,
117 lookup_coderef => sub {
118 my $rec = shift;
119 # store lookups
120 },
121 modify_records => {
122 900 => { '^a' => { ' : ' => '^b' } },
123 901 => { '*' => { '^b' => ' ; ' } },
124 },
125 modify_file => 'conf/modify/mapping.map',
126 save_row => sub {
127 my $a = shift;
128 $store->{ $a->{id} } = $a->{row};
129 },
130 load_row => sub {
131 my $a = shift;
132 return defined($store->{ $a->{id} }) &&
133 $store->{ $a->{id} };
134 },
135
136 );
137
138 By default, C<input_encoding> is assumed to be C<cp852>.
139
140 C<offset> is optional parametar to position at some offset before reading from database.
141
142 C<limit> is optional parametar to read just C<limit> records from database
143
144 C<stats> create optional report about usage of fields and subfields
145
146 C<lookup_coderef> is closure to called to save data into lookups
147
148 C<modify_records> specify mapping from subfields to delimiters or from
149 delimiters to subfields, as well as oprations on fields (if subfield is
150 defined as C<*>.
151
152 C<modify_file> is alternative for C<modify_records> above which preserves order and offers
153 (hopefully) simplier sintax than YAML or perl (see L</modify_file_regex>). This option
154 overrides C<modify_records> if both exists for same input.
155
156 C<save_row> and C<load_row> are low-level implementation of store engine. Calling convention
157 is documented in example above.
158
159 C<strict_encoding> should really default to 1, but it doesn't for now.
160
161 Returns size of database, regardless of C<offset> and C<limit>
162 parametars, see also C<size>.
163
164 =cut
165
166 sub open {
167 my $self = shift;
168 my $arg = {@_};
169
170 my $log = $self->_get_logger();
171 $log->debug( "arguments: ",dump( $arg ));
172
173 $log->logconfess("encoding argument is not suppored any more.") if $self->{encoding};
174 $log->logconfess("code_page argument is not suppored any more.") if $self->{code_page};
175 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_coderef") if ($arg->{lookup});
176 $log->logconfess("lookup_coderef must be CODE, not ",ref($arg->{lookup_coderef}))
177 if ($arg->{lookup_coderef} && ref($arg->{lookup_coderef}) ne 'CODE');
178
179 $log->debug( $arg->{lookup_coderef} ? '' : 'not ', "using lookup_coderef");
180
181 $log->logcroak("need path") if (! $arg->{'path'});
182 my $input_encoding = $arg->{'input_encoding'} || $self->{'input_encoding'} || 'cp852';
183
184 # store data in object
185 foreach my $v (qw/path offset limit/) {
186 $self->{$v} = $arg->{$v} if ($arg->{$v});
187 }
188
189 if ($arg->{load_row} || $arg->{save_row}) {
190 $log->logconfess("save_row and load_row must be defined in pair and be CODE") unless (
191 ref($arg->{load_row}) eq 'CODE' &&
192 ref($arg->{save_row}) eq 'CODE'
193 );
194 $self->{load_row} = $arg->{load_row};
195 $self->{save_row} = $arg->{save_row};
196 $log->debug("using load_row and save_row instead of in-memory hash");
197 }
198
199 my $filter_ref;
200 my $recode_regex;
201 my $recode_map;
202
203 if ($self->{recode}) {
204 my @r = split(/\s/, $self->{recode});
205 if ($#r % 2 != 1) {
206 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
207 } else {
208 while (@r) {
209 my $from = shift @r;
210 my $to = shift @r;
211 $recode_map->{$from} = $to;
212 }
213
214 $recode_regex = join '|' => keys %{ $recode_map };
215
216 $log->debug("using recode regex: $recode_regex");
217 }
218
219 }
220
221 my $rec_regex;
222 if (my $p = $arg->{modify_file}) {
223 $log->debug("using modify_file $p");
224 $rec_regex = $self->modify_file_regexps( $p );
225 } elsif (my $h = $arg->{modify_records}) {
226 $log->debug("using modify_records ", sub { dump( $h ) });
227 $rec_regex = $self->modify_record_regexps(%{ $h });
228 }
229 $log->debug("rec_regex: ", sub { dump($rec_regex) }) if ($rec_regex);
230
231 my $class = $self->{module} || $log->logconfess("can't get low-level module name!");
232
233 my $ll_db = $class->new(
234 path => $arg->{path},
235 input_config => $arg->{input_config} || $self->{input_config},
236 # filter => sub {
237 # my ($l,$f_nr) = @_;
238 # return unless defined($l);
239 # $l = decode($input_encoding, $l);
240 # $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
241 # return $l;
242 # },
243 %{ $arg },
244 );
245
246 unless (defined($ll_db)) {
247 $log->logwarn("can't open database $arg->{path}, skipping...");
248 return;
249 }
250
251 my $size = $ll_db->size;
252
253 unless ($size) {
254 $log->logwarn("no records in database $arg->{path}, skipping...");
255 return;
256 }
257
258 my $from_rec = 1;
259 my $to_rec = $size;
260
261 if (my $s = $self->{offset}) {
262 $log->debug("skipping to MFN $s");
263 $from_rec = $s;
264 } else {
265 $self->{offset} = $from_rec;
266 }
267
268 if ($self->{limit}) {
269 $log->debug("limiting to ",$self->{limit}," records");
270 $to_rec = $from_rec + $self->{limit} - 1;
271 $to_rec = $size if ($to_rec > $size);
272 }
273
274 # store size for later
275 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
276
277 my $strict_encoding = $arg->{strict_encoding} || $self->{strict_encoding}; ## FIXME should be 1 really
278
279 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec]",
280 " encoding $input_encoding ", $strict_encoding ? ' [strict]' : '',
281 $self->{stats} ? ' [stats]' : '',
282 );
283
284 # read database
285 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
286
287 $log->debug("position: $pos\n");
288
289 my $rec = $ll_db->fetch_rec($pos, sub {
290 my ($l,$f_nr,$debug) = @_;
291 # return unless defined($l);
292 # return $l unless ($rec_regex && $f_nr);
293
294 return unless ( defined($l) && defined($f_nr) );
295
296 warn "-=> $f_nr ## |$l|\n" if ($debug);
297 $log->debug("-=> $f_nr ## $l");
298
299 # codepage conversion and recode_regex
300 $l = decode($input_encoding, $l, 1);
301 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
302
303 # apply regexps
304 if ($rec_regex && defined($rec_regex->{$f_nr})) {
305 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
306 my $c = 0;
307 foreach my $r (@{ $rec_regex->{$f_nr} }) {
308 my $old_l = $l;
309 $log->logconfess("expected regex in ", dump( $r )) unless defined($r->{regex});
310 eval '$l =~ ' . $r->{regex};
311 if ($old_l ne $l) {
312 my $d = "|$old_l| -> |$l| "; # . $r->{regex};
313 $d .= ' +' . $r->{line} . ' ' . $r->{file} if defined($r->{line});
314 $d .= ' ' . $r->{debug} if defined($r->{debug});
315 $log->debug("MODIFY $d");
316 warn "*** $d\n" if ($debug);
317
318 }
319 $log->error("error applying regex: ",dump($r), $@) if $@;
320 }
321 }
322
323 $log->debug("<=- $f_nr ## |$l|");
324 warn "<=- $f_nr ## $l\n" if ($debug);
325 return $l;
326 });
327
328 $log->debug(sub { dump($rec) });
329
330 if (! $rec) {
331 $log->warn("record $pos empty? skipping...");
332 next;
333 }
334
335 # store
336 if ($self->{save_row}) {
337 $self->{save_row}->({
338 id => $pos,
339 row => $rec,
340 });
341 } else {
342 $self->{data}->{$pos} = $rec;
343 }
344
345 # create lookup
346 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
347
348 # update counters for statistics
349 if ($self->{stats}) {
350
351 # fetch clean record with regexpes applied for statistics
352 my $rec = $ll_db->fetch_rec($pos);
353
354 foreach my $fld (keys %{ $rec }) {
355 $self->{_stats}->{fld}->{ $fld }++;
356
357 #$log->logdie("invalid record fild $fld, not ARRAY")
358 next unless (ref($rec->{ $fld }) eq 'ARRAY');
359
360 foreach my $row (@{ $rec->{$fld} }) {
361
362 if (ref($row) eq 'HASH') {
363
364 foreach my $sf (keys %{ $row }) {
365 next if ($sf eq 'subfields');
366 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
367 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
368 if (ref($row->{$sf}) eq 'ARRAY');
369 }
370
371 } else {
372 $self->{_stats}->{repeatable}->{ $fld }++;
373 }
374 }
375 }
376 }
377
378 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
379
380 }
381
382 $self->{pos} = -1;
383 $self->{last_pcnt} = 0;
384
385 # store max mfn and return it.
386 $self->{max_pos} = $to_rec;
387 $log->debug("max_pos: $to_rec");
388
389 # save for dump
390 $self->{ll_db} = $ll_db;
391
392 return $size;
393 }
394
395 sub input_module { $_[0]->{ll_db} }
396
397 =head2 fetch
398
399 Fetch next record from database. It will also displays progress bar.
400
401 my $rec = $isis->fetch;
402
403 Record from this function should probably go to C<data_structure> for
404 normalisation.
405
406 =cut
407
408 sub fetch {
409 my $self = shift;
410
411 my $log = $self->_get_logger();
412
413 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
414
415 if ($self->{pos} == -1) {
416 $self->{pos} = $self->{offset};
417 } else {
418 $self->{pos}++;
419 }
420
421 my $mfn = $self->{pos};
422
423 if ($mfn > $self->{max_pos}) {
424 $self->{pos} = $self->{max_pos};
425 $log->debug("at EOF");
426 return;
427 }
428
429 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
430
431 my $rec;
432
433 if ($self->{load_row}) {
434 $rec = $self->{load_row}->({ id => $mfn });
435 } else {
436 $rec = $self->{data}->{$mfn};
437 }
438
439 $rec ||= 0E0;
440 }
441
442 =head2 pos
443
444 Returns current record number (MFN).
445
446 print $isis->pos;
447
448 First record in database has position 1.
449
450 =cut
451
452 sub pos {
453 my $self = shift;
454 return $self->{pos};
455 }
456
457
458 =head2 size
459
460 Returns number of records in database
461
462 print $isis->size;
463
464 Result from this function can be used to loop through all records
465
466 foreach my $mfn ( 1 ... $isis->size ) { ... }
467
468 because it takes into account C<offset> and C<limit>.
469
470 =cut
471
472 sub size {
473 my $self = shift;
474 return $self->{size};
475 }
476
477 =head2 seek
478
479 Seek to specified MFN in file.
480
481 $isis->seek(42);
482
483 First record in database has position 1.
484
485 =cut
486
487 sub seek {
488 my $self = shift;
489 my $pos = shift;
490
491 my $log = $self->_get_logger();
492
493 $log->logconfess("called without pos") unless defined($pos);
494
495 if ($pos < 1) {
496 $log->warn("seek before first record");
497 $pos = 1;
498 } elsif ($pos > $self->{max_pos}) {
499 $log->warn("seek beyond last record");
500 $pos = $self->{max_pos};
501 }
502
503 return $self->{pos} = (($pos - 1) || -1);
504 }
505
506 =head2 stats
507
508 Dump statistics about field and subfield usage
509
510 print $input->stats;
511
512 =cut
513
514 sub stats {
515 my $self = shift;
516
517 my $log = $self->_get_logger();
518
519 my $s = $self->{_stats};
520 if (! $s) {
521 $log->warn("called stats, but there is no statistics collected");
522 return;
523 }
524
525 my $max_fld = 0;
526
527 my $out = join("\n",
528 map {
529 my $f = $_;
530 die "no field in ", dump( $s->{fld} ) unless defined( $f );
531 my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
532 $max_fld = $v if ($v > $max_fld);
533
534 my $o = sprintf("%4s %d ~", $f, $v);
535
536 if (defined($s->{sf}->{$f})) {
537 my @subfields = keys %{ $s->{sf}->{$f} };
538 map {
539 $o .= sprintf(" %s:%d%s", $_,
540 $s->{sf}->{$f}->{$_}->{count},
541 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
542 );
543 } (
544 # first indicators and other special subfields
545 sort( grep { length($_) > 1 } @subfields ),
546 # then subfileds (single char)
547 sort( grep { length($_) == 1 } @subfields ),
548 );
549 }
550
551 if (my $v_r = $s->{repeatable}->{$f}) {
552 $o .= " ($v_r)" if ($v_r != $v);
553 }
554
555 $o;
556 } sort {
557 if ( $a =~ m/^\d+$/ && $b =~ m/^\d+$/ ) {
558 $a <=> $b
559 } else {
560 $a cmp $b
561 }
562 } keys %{ $s->{fld} }
563 );
564
565 $log->debug( sub { dump($s) } );
566
567 my $path = 'var/stats.yml';
568 YAML::DumpFile( $path, $s );
569 $log->info( 'created ', $path, ' with ', -s $path, ' bytes' );
570
571 return $out;
572 }
573
574 =head2 dump_ascii
575
576 Display humanly readable dump of record
577
578 =cut
579
580 sub dump_ascii {
581 my $self = shift;
582
583 return unless $self->{ll_db};
584
585 if ($self->{ll_db}->can('dump_ascii')) {
586 return $self->{ll_db}->dump_ascii( $self->{pos} );
587 } else {
588 return dump( $self->{ll_db}->fetch_rec( $self->{pos} ) );
589 }
590 }
591
592 =head2 _get_regex
593
594 Helper function called which create regexps to be execute on code.
595
596 _get_regex( 900, 'regex:[0-9]+' ,'numbers' );
597 _get_regex( 900, '^b', ' : ^b' );
598
599 It supports perl regexps with C<regex:> prefix to from value and has
600 additional logic to skip empty subfields.
601
602 =cut
603
604 sub _get_regex {
605 my ($sf,$from,$to) = @_;
606
607 # protect /
608 $from =~ s!/!\\/!gs;
609 $to =~ s!/!\\/!gs;
610
611 if ($from =~ m/^regex:(.+)$/) {
612 $from = $1;
613 } else {
614 $from = '\Q' . $from . '\E';
615 }
616 if ($sf =~ /^\^/) {
617 my $need_subfield_data = '*'; # no
618 # if from is also subfield, require some data in between
619 # to correctly skip empty subfields
620 $need_subfield_data = '+' if ($from =~ m/^\\Q\^/);
621 return
622 's/\Q'. $sf .'\E([^\^]' . $need_subfield_data . '?)'. $from .'([^\^]*?)/'. $sf .'$1'. $to .'$2/';
623 } else {
624 return
625 's/'. $from .'/'. $to .'/g';
626 }
627 }
628
629
630 =head2 modify_record_regexps
631
632 Generate hash with regexpes to be applied using L<filter>.
633
634 my $regexpes = $input->modify_record_regexps(
635 900 => { '^a' => { ' : ' => '^b' } },
636 901 => { '*' => { '^b' => ' ; ' } },
637 );
638
639 =cut
640
641 sub modify_record_regexps {
642 my $self = shift;
643 my $modify_record = {@_};
644
645 my $regexpes;
646
647 my $log = $self->_get_logger();
648
649 foreach my $f (keys %$modify_record) {
650 $log->debug("field: $f");
651
652 foreach my $sf (keys %{ $modify_record->{$f} }) {
653 $log->debug("subfield: $sf");
654
655 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
656 my $to = $modify_record->{$f}->{$sf}->{$from};
657 #die "no field?" unless defined($to);
658 my $d = "|$from| -> |$to|";
659 $log->debug("transform: $d");
660
661 my $regex = _get_regex($sf,$from,$to);
662 push @{ $regexpes->{$f} }, { regex => $regex, debug => $d };
663 $log->debug("regex: $regex");
664 }
665 }
666 }
667
668 return $regexpes;
669 }
670
671 =head2 modify_file_regexps
672
673 Generate hash with regexpes to be applied using L<filter> from
674 pseudo hash/yaml format for regex mappings.
675
676 It should be obvious:
677
678 200
679 '^a'
680 ' : ' => '^e'
681 ' = ' => '^d'
682
683 In field I<200> find C<'^a'> and then C<' : '>, and replace it with C<'^e'>.
684 In field I<200> find C<'^a'> and then C<' = '>, and replace it with C<'^d'>.
685
686 my $regexpes = $input->modify_file_regexps( 'conf/modify/common.pl' );
687
688 On undef path it will just return.
689
690 =cut
691
692 sub modify_file_regexps {
693 my $self = shift;
694
695 my $modify_path = shift || return;
696
697 my $log = $self->_get_logger();
698
699 my $regexpes;
700
701 CORE::open(my $fh, $modify_path) || $log->logdie("can't open modify file $modify_path: $!");
702
703 my ($f,$sf);
704
705 while(<$fh>) {
706 chomp;
707 next if (/^#/ || /^\s*$/);
708
709 if (/^\s*(\d+)\s*$/) {
710 $f = $1;
711 $log->debug("field: $f");
712 next;
713 } elsif (/^\s*'([^']*)'\s*$/) {
714 $sf = $1;
715 $log->die("can't define subfiled before field in: $_") unless ($f);
716 $log->debug("subfield: $sf");
717 } elsif (/^\s*'([^']*)'\s*=>\s*'([^']*)'\s*$/) {
718 my ($from,$to) = ($1, $2);
719
720 $log->debug("transform: |$from| -> |$to|");
721
722 my $regex = _get_regex($sf,$from,$to);
723 push @{ $regexpes->{$f} }, {
724 regex => $regex,
725 file => $modify_path,
726 line => $.,
727 };
728 $log->debug("regex: $regex");
729 } else {
730 die "can't parse: $_";
731 }
732 }
733
734 return $regexpes;
735 }
736
737 =head1 AUTHOR
738
739 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
740
741 =head1 COPYRIGHT & LICENSE
742
743 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
744
745 This program is free software; you can redistribute it and/or modify it
746 under the same terms as Perl itself.
747
748 =cut
749
750 1; # End of WebPAC::Input

  ViewVC Help
Powered by ViewVC 1.1.26