/[webpac2]/trunk/lib/WebPAC/Input.pm
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Revision 784 - (show annotations)
Wed Dec 6 23:43:45 2006 UTC (17 years, 4 months ago) by dpavlin
File size: 15423 byte(s)
added regex: to modify_records

1 package WebPAC::Input;
2
3 use warnings;
4 use strict;
5
6 use blib;
7
8 use WebPAC::Common;
9 use base qw/WebPAC::Common/;
10 use Data::Dump qw/dump/;
11 use Encode qw/from_to/;
12
13 =head1 NAME
14
15 WebPAC::Input - read different file formats into WebPAC
16
17 =head1 VERSION
18
19 Version 0.16
20
21 =cut
22
23 our $VERSION = '0.16';
24
25 =head1 SYNOPSIS
26
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>.
30
31 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 Perhaps a little code snippet.
41
42 use WebPAC::Input;
43
44 my $db = WebPAC::Input->new(
45 module => 'WebPAC::Input::ISIS',
46 );
47
48 $db->open( path => '/path/to/database' );
49 print "database size: ",$db->size,"\n";
50 while (my $rec = $db->fetch) {
51 # do something with $rec
52 }
53
54
55
56 =head1 FUNCTIONS
57
58 =head2 new
59
60 Create new input database object.
61
62 my $db = new WebPAC::Input(
63 module => 'WebPAC::Input::MARC',
64 encoding => 'ISO-8859-2',
65 recode => 'char pairs',
66 no_progress_bar => 1,
67 );
68
69 C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
70 L<WebPAC::Input::MARC>.
71
72 Optional parametar C<encoding> specify application code page (which will be
73 used internally). This should probably be your terminal encoding, and by
74 default, it C<ISO-8859-2>.
75
76 C<recode> is optional string constisting of character or words pairs that
77 should be replaced in input stream.
78
79 C<no_progress_bar> disables progress bar output on C<STDOUT>
80
81 This function will also call low-level C<init> if it exists with same
82 parametars.
83
84 =cut
85
86 sub new {
87 my $class = shift;
88 my $self = {@_};
89 bless($self, $class);
90
91 my $log = $self->_get_logger;
92
93 $log->logconfess("code_page argument is not suppored any more. change it to encoding") if ($self->{lookup});
94 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_ref") if ($self->{lookup});
95 $log->logconfess("low_mem argument is not suppored any more. rewrite it to load_row and save_row") if ($self->{low_mem});
96
97 $log->logconfess("specify low-level file format module") unless ($self->{module});
98 my $module_path = $self->{module};
99 $module_path =~ s#::#/#g;
100 $module_path .= '.pm';
101 $log->debug("require low-level module $self->{module} from $module_path");
102
103 require $module_path;
104
105 $self->{'encoding'} ||= 'ISO-8859-2';
106
107 $self ? return $self : return undef;
108 }
109
110 =head2 open
111
112 This function will read whole database in memory and produce lookups.
113
114 my $store; # simple in-memory hash
115
116 $input->open(
117 path => '/path/to/database/file',
118 code_page => 'cp852',
119 limit => 500,
120 offset => 6000,
121 stats => 1,
122 lookup_coderef => sub {
123 my $rec = shift;
124 # store lookups
125 },
126 modify_records => {
127 900 => { '^a' => { ' : ' => '^b' } },
128 901 => { '*' => { '^b' => ' ; ' } },
129 },
130 modify_file => 'conf/modify/mapping.map',
131 save_row => sub {
132 my $a = shift;
133 $store->{ $a->{id} } = $a->{row};
134 },
135 load_row => sub {
136 my $a = shift;
137 return defined($store->{ $a->{id} }) &&
138 $store->{ $a->{id} };
139 },
140
141 );
142
143 By default, C<code_page> is assumed to be C<cp852>.
144
145 C<offset> is optional parametar to position at some offset before reading from database.
146
147 C<limit> is optional parametar to read just C<limit> records from database
148
149 C<stats> create optional report about usage of fields and subfields
150
151 C<lookup_coderef> is closure to called to save data into lookups
152
153 C<modify_records> specify mapping from subfields to delimiters or from
154 delimiters to subfields, as well as oprations on fields (if subfield is
155 defined as C<*>.
156
157 C<modify_file> is alternative for C<modify_records> above which preserves order and offers
158 (hopefully) simplier sintax than YAML or perl (see L</modify_file_regex>). This option
159 overrides C<modify_records> if both exists for same input.
160
161 C<save_row> and C<load_row> are low-level implementation of store engine. Calling convention
162 is documented in example above.
163
164 Returns size of database, regardless of C<offset> and C<limit>
165 parametars, see also C<size>.
166
167 =cut
168
169 sub open {
170 my $self = shift;
171 my $arg = {@_};
172
173 my $log = $self->_get_logger();
174
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 $code_page = $arg->{'code_page'} || 'cp852';
183
184 # store data in object
185 $self->{'input_code_page'} = $code_page;
186 foreach my $v (qw/path offset limit/) {
187 $self->{$v} = $arg->{$v} if ($arg->{$v});
188 }
189
190 if ($arg->{load_row} || $arg->{save_row}) {
191 $log->logconfess("save_row and load_row must be defined in pair and be CODE") unless (
192 ref($arg->{load_row}) eq 'CODE' &&
193 ref($arg->{save_row}) eq 'CODE'
194 );
195 $self->{load_row} = $arg->{load_row};
196 $self->{save_row} = $arg->{save_row};
197 $log->debug("using load_row and save_row instead of in-memory hash");
198 }
199
200 my $filter_ref;
201 my $recode_regex;
202 my $recode_map;
203
204 if ($self->{recode}) {
205 my @r = split(/\s/, $self->{recode});
206 if ($#r % 2 != 1) {
207 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
208 } else {
209 while (@r) {
210 my $from = shift @r;
211 my $to = shift @r;
212 $recode_map->{$from} = $to;
213 }
214
215 $recode_regex = join '|' => keys %{ $recode_map };
216
217 $log->debug("using recode regex: $recode_regex");
218 }
219
220 }
221
222 my $rec_regex;
223 if (my $p = $arg->{modify_file}) {
224 $log->debug("using modify_file $p");
225 $rec_regex = $self->modify_file_regexps( $p );
226 } elsif (my $h = $arg->{modify_records}) {
227 $log->debug("using modify_records ", sub { dump( $h ) });
228 $rec_regex = $self->modify_record_regexps(%{ $h });
229 }
230 $log->debug("rec_regex: ", sub { dump($rec_regex) }) if ($rec_regex);
231
232 my $class = $self->{module} || $log->logconfess("can't get low-level module name!");
233
234 my $ll_db = $class->new(
235 path => $arg->{path},
236 # filter => sub {
237 # my ($l,$f_nr) = @_;
238 # return unless defined($l);
239 # from_to($l, $code_page, $self->{'encoding'});
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 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
278
279 # read database
280 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
281
282 $log->debug("position: $pos\n");
283
284 my $rec = $ll_db->fetch_rec($pos, sub {
285 my ($l,$f_nr) = @_;
286 # return unless defined($l);
287 # return $l unless ($rec_regex && $f_nr);
288
289 $log->debug("-=> $f_nr ## $l");
290
291 # codepage conversion and recode_regex
292 from_to($l, $code_page, $self->{'encoding'});
293 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
294
295 # apply regexps
296 if ($rec_regex && defined($rec_regex->{$f_nr})) {
297 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
298 my $c = 0;
299 foreach my $r (@{ $rec_regex->{$f_nr} }) {
300 my $old_l = $l;
301 eval '$l =~ ' . $r;
302 if ($old_l ne $l) {
303 $log->debug("REGEX on $f_nr eval \$l =~ $r\n## old l: [$old_l]\n## new l: [$l]");
304 }
305 $log->error("error applying regex: $r") if ($@);
306 }
307 }
308
309 $log->debug("<=- $f_nr ## $l");
310 return $l;
311 });
312
313 $log->debug(sub { dump($rec) });
314
315 if (! $rec) {
316 $log->warn("record $pos empty? skipping...");
317 next;
318 }
319
320 # store
321 if ($self->{save_row}) {
322 $self->{save_row}->({
323 id => $pos,
324 row => $rec,
325 });
326 } else {
327 $self->{data}->{$pos} = $rec;
328 }
329
330 # create lookup
331 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
332
333 # update counters for statistics
334 if ($self->{stats}) {
335
336 # fetch clean record with regexpes applied for statistics
337 my $rec = $ll_db->fetch_rec($pos);
338
339 foreach my $fld (keys %{ $rec }) {
340 $self->{_stats}->{fld}->{ $fld }++;
341
342 $log->logdie("invalid record fild $fld, not ARRAY")
343 unless (ref($rec->{ $fld }) eq 'ARRAY');
344
345 foreach my $row (@{ $rec->{$fld} }) {
346
347 if (ref($row) eq 'HASH') {
348
349 foreach my $sf (keys %{ $row }) {
350 next if ($sf eq 'subfields');
351 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
352 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
353 if (ref($row->{$sf}) eq 'ARRAY');
354 }
355
356 } else {
357 $self->{_stats}->{repeatable}->{ $fld }++;
358 }
359 }
360 }
361 }
362
363 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
364
365 }
366
367 $self->{pos} = -1;
368 $self->{last_pcnt} = 0;
369
370 # store max mfn and return it.
371 $self->{max_pos} = $to_rec;
372 $log->debug("max_pos: $to_rec");
373
374 # save for dump
375 $self->{ll_db} = $ll_db;
376
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 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
397
398 if ($self->{pos} == -1) {
399 $self->{pos} = $self->{offset};
400 } else {
401 $self->{pos}++;
402 }
403
404 my $mfn = $self->{pos};
405
406 if ($mfn > $self->{max_pos}) {
407 $self->{pos} = $self->{max_pos};
408 $log->debug("at EOF");
409 return;
410 }
411
412 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
413
414 my $rec;
415
416 if ($self->{load_row}) {
417 $rec = $self->{load_row}->({ id => $mfn });
418 } else {
419 $rec = $self->{data}->{$mfn};
420 }
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 return $self->{pos};
438 }
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 because it takes into account C<offset> and C<limit>.
452
453 =cut
454
455 sub size {
456 my $self = shift;
457 return $self->{size};
458 }
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 $pos = 1;
479 } elsif ($pos > $self->{max_pos}) {
480 $log->warn("seek beyond last record");
481 $pos = $self->{max_pos};
482 }
483
484 return $self->{pos} = (($pos - 1) || -1);
485 }
486
487 =head2 stats
488
489 Dump statistics about field and subfield usage
490
491 print $input->stats;
492
493 =cut
494
495 sub stats {
496 my $self = shift;
497
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 my $o = sprintf("%4s %d ~", $f, $v);
515
516 if (defined($s->{sf}->{$f})) {
517 map {
518 $o .= sprintf(" %s:%d%s", $_,
519 $s->{sf}->{$f}->{$_}->{count},
520 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
521 );
522 } 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 } sort { $a cmp $b } keys %{ $s->{fld} }
531 );
532
533 $log->debug( sub { dump($s) } );
534
535 return $out;
536 }
537
538 =head2 dump_ascii
539
540 Display humanly readable dump of record
541
542 =cut
543
544 sub dump_ascii {
545 my $self = shift;
546
547 return unless $self->{ll_db};
548
549 if ($self->{ll_db}->can('dump_rec')) {
550 return $self->{ll_db}->dump_ascii( $self->{pos} );
551 } else {
552 return dump( $self->{ll_db}->fetch_rec( $self->{pos} ) );
553 }
554 }
555
556 =head2 modify_record_regexps
557
558 Generate hash with regexpes to be applied using l<filter>.
559
560 my $regexpes = $input->modify_record_regexps(
561 900 => { '^a' => { ' : ' => '^b' } },
562 901 => { '*' => { '^b' => ' ; ' } },
563 );
564
565 =cut
566
567 sub _get_regex {
568 my ($sf,$from,$to) = @_;
569 if ($from =~ m/^regex:(.+)$/) {
570 $from = $1;
571 } else {
572 $from = '\Q' . $from . '\E';
573 }
574 if ($sf =~ /^\^/) {
575 return
576 's/\Q'. $sf .'\E([^\^]*?)'. $from .'([^\^]*?)/'. $sf .'$1'. $to .'$2/';
577 } else {
578 return
579 's/'. $from .'/'. $to .'/g';
580 }
581 }
582
583 sub modify_record_regexps {
584 my $self = shift;
585 my $modify_record = {@_};
586
587 my $regexpes;
588
589 my $log = $self->_get_logger();
590
591 foreach my $f (keys %$modify_record) {
592 $log->debug("field: $f");
593
594 foreach my $sf (keys %{ $modify_record->{$f} }) {
595 $log->debug("subfield: $sf");
596
597 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
598 my $to = $modify_record->{$f}->{$sf}->{$from};
599 #die "no field?" unless defined($to);
600 $log->debug("transform: |$from| -> |$to|");
601
602 my $regex = _get_regex($sf,$from,$to);
603 push @{ $regexpes->{$f} }, $regex;
604 $log->debug("regex: $regex");
605 }
606 }
607 }
608
609 return $regexpes;
610 }
611
612 =head2 modify_file_regexps
613
614 Generate hash with regexpes to be applied using l<filter> from
615 pseudo hash/yaml format for regex mappings.
616
617 It should be obvious:
618
619 200
620 '^a'
621 ' : ' => '^e'
622 ' = ' => '^d'
623
624 In field I<200> find C<'^a'> and then C<' : '>, and replace it with C<'^e'>.
625 In field I<200> find C<'^a'> and then C<' = '>, and replace it with C<'^d'>.
626
627 my $regexpes = $input->modify_file_regexps( 'conf/modify/common.pl' );
628
629 On undef path it will just return.
630
631 =cut
632
633 sub modify_file_regexps {
634 my $self = shift;
635
636 my $modify_path = shift || return;
637
638 my $log = $self->_get_logger();
639
640 my $regexpes;
641
642 CORE::open(my $fh, $modify_path) || $log->logdie("can't open modify file $modify_path: $!");
643
644 my ($f,$sf);
645
646 while(<$fh>) {
647 chomp;
648 next if (/^#/ || /^\s*$/);
649
650 if (/^\s*(\d+)\s*$/) {
651 $f = $1;
652 $log->debug("field: $f");
653 next;
654 } elsif (/^\s*'([^']*)'\s*$/) {
655 $sf = $1;
656 $log->die("can't define subfiled before field in: $_") unless ($f);
657 $log->debug("subfield: $sf");
658 } elsif (/^\s*'([^']*)'\s*=>\s*'([^']*)'\s*$/) {
659 my ($from,$to) = ($1, $2);
660
661 $log->debug("transform: |$from| -> |$to|");
662
663 my $regex = _get_regex($sf,$from,$to);
664 push @{ $regexpes->{$f} }, $regex;
665 $log->debug("regex: $regex");
666 }
667 }
668
669 return $regexpes;
670 }
671
672 =head1 AUTHOR
673
674 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
675
676 =head1 COPYRIGHT & LICENSE
677
678 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
679
680 This program is free software; you can redistribute it and/or modify it
681 under the same terms as Perl itself.
682
683 =cut
684
685 1; # End of WebPAC::Input

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