/[webpac2]/trunk/lib/WebPAC/Input.pm
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Revision 761 - (show annotations)
Wed Oct 25 17:10:08 2006 UTC (17 years, 6 months ago) by dpavlin
File size: 15290 byte(s)
implemented load_row and save_row closures to serialize
input databases (using WebPAC::Store probably).
This will allow lookups to share on-disk storage with
low_mem option of WebPAC::Input, which is now gone
(under pressure of 600000+ record database which we
are now testing on)

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::Dumper;
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 0.14
20
21 =cut
22
23 our $VERSION = '0.14';
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 # check if required subclasses are implemented
106 foreach my $subclass (qw/open_db fetch_rec init dump_rec/) {
107 # FIXME
108 }
109
110 $self->{'encoding'} ||= 'ISO-8859-2';
111
112 $self ? return $self : return undef;
113 }
114
115 =head2 open
116
117 This function will read whole database in memory and produce lookups.
118
119 my $store; # simple in-memory hash
120
121 $input->open(
122 path => '/path/to/database/file',
123 code_page => 'cp852',
124 limit => 500,
125 offset => 6000,
126 stats => 1,
127 lookup_coderef => sub {
128 my $rec = shift;
129 # store lookups
130 },
131 modify_records => {
132 900 => { '^a' => { ' : ' => '^b' } },
133 901 => { '*' => { '^b' => ' ; ' } },
134 },
135 modify_file => 'conf/modify/mapping.map',
136 save_row => sub {
137 my $a = shift;
138 $store->{ $a->{id} } = $a->{row};
139 },
140 load_row => sub {
141 my $a = shift;
142 return defined($store->{ $a->{id} }) &&
143 $store->{ $a->{id} };
144 },
145
146 );
147
148 By default, C<code_page> is assumed to be C<cp852>.
149
150 C<offset> is optional parametar to position at some offset before reading from database.
151
152 C<limit> is optional parametar to read just C<limit> records from database
153
154 C<stats> create optional report about usage of fields and subfields
155
156 C<lookup_coderef> is closure to called to save data into lookups
157
158 C<modify_records> specify mapping from subfields to delimiters or from
159 delimiters to subfields, as well as oprations on fields (if subfield is
160 defined as C<*>.
161
162 C<modify_file> is alternative for C<modify_records> above which preserves order and offers
163 (hopefully) simplier sintax than YAML or perl (see L</modify_file_regex>). This option
164 overrides C<modify_records> if both exists for same input.
165
166 C<save_row> and C<load_row> are low-level implementation of store engine. Calling convention
167 is documented in example above.
168
169 Returns size of database, regardless of C<offset> and C<limit>
170 parametars, see also C<size>.
171
172 =cut
173
174 sub open {
175 my $self = shift;
176 my $arg = {@_};
177
178 my $log = $self->_get_logger();
179
180 $log->logconfess("lookup argument is not suppored any more. rewrite call to lookup_coderef") if ($arg->{lookup});
181 $log->logconfess("lookup_coderef must be CODE, not ",ref($arg->{lookup_coderef}))
182 if ($arg->{lookup_coderef} && ref($arg->{lookup_coderef}) ne 'CODE');
183
184 $log->debug( $arg->{lookup_coderef} ? '' : 'not ', "using lookup_coderef");
185
186 $log->logcroak("need path") if (! $arg->{'path'});
187 my $code_page = $arg->{'code_page'} || 'cp852';
188
189 # store data in object
190 $self->{'input_code_page'} = $code_page;
191 foreach my $v (qw/path offset limit/) {
192 $self->{$v} = $arg->{$v} if ($arg->{$v});
193 }
194
195 if ($arg->{load_row} || $arg->{save_row}) {
196 $log->logconfess("save_row and load_row must be defined in pair and be CODE") unless (
197 ref($arg->{load_row}) eq 'CODE' &&
198 ref($arg->{save_row}) eq 'CODE'
199 );
200 $self->{load_row} = $arg->{load_row};
201 $self->{save_row} = $arg->{save_row};
202 $log->debug("using load_row and save_row instead of in-memory hash");
203 }
204
205 my $filter_ref;
206 my $recode_regex;
207 my $recode_map;
208
209 if ($self->{recode}) {
210 my @r = split(/\s/, $self->{recode});
211 if ($#r % 2 != 1) {
212 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
213 } else {
214 while (@r) {
215 my $from = shift @r;
216 my $to = shift @r;
217 $recode_map->{$from} = $to;
218 }
219
220 $recode_regex = join '|' => keys %{ $recode_map };
221
222 $log->debug("using recode regex: $recode_regex");
223 }
224
225 }
226
227 my $rec_regex;
228 if (my $p = $arg->{modify_file}) {
229 $log->debug("using modify_file $p");
230 $rec_regex = $self->modify_file_regexps( $p );
231 } elsif (my $h = $arg->{modify_records}) {
232 $log->debug("using modify_records ", Dumper( $h ));
233 $rec_regex = $self->modify_record_regexps(%{ $h });
234 }
235 $log->debug("rec_regex: ", Dumper($rec_regex)) if ($rec_regex);
236
237 my $class = $self->{module} || $log->logconfess("can't get low-level module name!");
238
239 my $ll_db = $class->new(
240 path => $arg->{path},
241 # filter => sub {
242 # my ($l,$f_nr) = @_;
243 # return unless defined($l);
244 # from_to($l, $code_page, $self->{'encoding'});
245 # $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
246 # return $l;
247 # },
248 %{ $arg },
249 );
250
251 unless (defined($ll_db)) {
252 $log->logwarn("can't open database $arg->{path}, skipping...");
253 return;
254 }
255
256 my $size = $ll_db->size;
257
258 unless ($size) {
259 $log->logwarn("no records in database $arg->{path}, skipping...");
260 return;
261 }
262
263 my $from_rec = 1;
264 my $to_rec = $size;
265
266 if (my $s = $self->{offset}) {
267 $log->debug("skipping to MFN $s");
268 $from_rec = $s;
269 } else {
270 $self->{offset} = $from_rec;
271 }
272
273 if ($self->{limit}) {
274 $log->debug("limiting to ",$self->{limit}," records");
275 $to_rec = $from_rec + $self->{limit} - 1;
276 $to_rec = $size if ($to_rec > $size);
277 }
278
279 # store size for later
280 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
281
282 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
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) = @_;
291 # return unless defined($l);
292 # return $l unless ($rec_regex && $f_nr);
293
294 $log->debug("-=> $f_nr ## $l");
295
296 # codepage conversion and recode_regex
297 from_to($l, $code_page, $self->{'encoding'});
298 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
299
300 # apply regexps
301 if ($rec_regex && defined($rec_regex->{$f_nr})) {
302 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
303 my $c = 0;
304 foreach my $r (@{ $rec_regex->{$f_nr} }) {
305 my $old_l = $l;
306 eval '$l =~ ' . $r;
307 if ($old_l ne $l) {
308 $log->debug("REGEX on $f_nr eval \$l =~ $r\n## old l: [$old_l]\n## new l: [$l]");
309 }
310 $log->error("error applying regex: $r") if ($@);
311 }
312 }
313
314 $log->debug("<=- $f_nr ## $l");
315 return $l;
316 });
317
318 $log->debug(sub { Dumper($rec) });
319
320 if (! $rec) {
321 $log->warn("record $pos empty? skipping...");
322 next;
323 }
324
325 # store
326 if ($self->{save_row}) {
327 $self->{save_row}->({
328 id => $pos,
329 row => $rec,
330 });
331 } else {
332 $self->{data}->{$pos} = $rec;
333 }
334
335 # create lookup
336 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
337
338 # update counters for statistics
339 if ($self->{stats}) {
340
341 # fetch clean record with regexpes applied for statistics
342 my $rec = $ll_db->fetch_rec($pos);
343
344 foreach my $fld (keys %{ $rec }) {
345 $self->{_stats}->{fld}->{ $fld }++;
346
347 $log->logdie("invalid record fild $fld, not ARRAY")
348 unless (ref($rec->{ $fld }) eq 'ARRAY');
349
350 foreach my $row (@{ $rec->{$fld} }) {
351
352 if (ref($row) eq 'HASH') {
353
354 foreach my $sf (keys %{ $row }) {
355 next if ($sf eq 'subfields');
356 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
357 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
358 if (ref($row->{$sf}) eq 'ARRAY');
359 }
360
361 } else {
362 $self->{_stats}->{repeatable}->{ $fld }++;
363 }
364 }
365 }
366 }
367
368 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
369
370 }
371
372 $self->{pos} = -1;
373 $self->{last_pcnt} = 0;
374
375 # store max mfn and return it.
376 $self->{max_pos} = $to_rec;
377 $log->debug("max_pos: $to_rec");
378
379 # save for dump
380 $self->{ll_db} = $ll_db;
381
382 return $size;
383 }
384
385 =head2 fetch
386
387 Fetch next record from database. It will also displays progress bar.
388
389 my $rec = $isis->fetch;
390
391 Record from this function should probably go to C<data_structure> for
392 normalisation.
393
394 =cut
395
396 sub fetch {
397 my $self = shift;
398
399 my $log = $self->_get_logger();
400
401 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
402
403 if ($self->{pos} == -1) {
404 $self->{pos} = $self->{offset};
405 } else {
406 $self->{pos}++;
407 }
408
409 my $mfn = $self->{pos};
410
411 if ($mfn > $self->{max_pos}) {
412 $self->{pos} = $self->{max_pos};
413 $log->debug("at EOF");
414 return;
415 }
416
417 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
418
419 my $rec;
420
421 if ($self->{load_row}) {
422 $rec = $self->{load_row}->({ id => $mfn });
423 } else {
424 $rec = $self->{data}->{$mfn};
425 }
426
427 $rec ||= 0E0;
428 }
429
430 =head2 pos
431
432 Returns current record number (MFN).
433
434 print $isis->pos;
435
436 First record in database has position 1.
437
438 =cut
439
440 sub pos {
441 my $self = shift;
442 return $self->{pos};
443 }
444
445
446 =head2 size
447
448 Returns number of records in database
449
450 print $isis->size;
451
452 Result from this function can be used to loop through all records
453
454 foreach my $mfn ( 1 ... $isis->size ) { ... }
455
456 because it takes into account C<offset> and C<limit>.
457
458 =cut
459
460 sub size {
461 my $self = shift;
462 return $self->{size};
463 }
464
465 =head2 seek
466
467 Seek to specified MFN in file.
468
469 $isis->seek(42);
470
471 First record in database has position 1.
472
473 =cut
474
475 sub seek {
476 my $self = shift;
477 my $pos = shift || return;
478
479 my $log = $self->_get_logger();
480
481 if ($pos < 1) {
482 $log->warn("seek before first record");
483 $pos = 1;
484 } elsif ($pos > $self->{max_pos}) {
485 $log->warn("seek beyond last record");
486 $pos = $self->{max_pos};
487 }
488
489 return $self->{pos} = (($pos - 1) || -1);
490 }
491
492 =head2 stats
493
494 Dump statistics about field and subfield usage
495
496 print $input->stats;
497
498 =cut
499
500 sub stats {
501 my $self = shift;
502
503 my $log = $self->_get_logger();
504
505 my $s = $self->{_stats};
506 if (! $s) {
507 $log->warn("called stats, but there is no statistics collected");
508 return;
509 }
510
511 my $max_fld = 0;
512
513 my $out = join("\n",
514 map {
515 my $f = $_ || die "no field";
516 my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
517 $max_fld = $v if ($v > $max_fld);
518
519 my $o = sprintf("%4s %d ~", $f, $v);
520
521 if (defined($s->{sf}->{$f})) {
522 map {
523 $o .= sprintf(" %s:%d%s", $_,
524 $s->{sf}->{$f}->{$_}->{count},
525 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
526 );
527 } sort keys %{ $s->{sf}->{$f} };
528 }
529
530 if (my $v_r = $s->{repeatable}->{$f}) {
531 $o .= " ($v_r)" if ($v_r != $v);
532 }
533
534 $o;
535 } sort { $a cmp $b } keys %{ $s->{fld} }
536 );
537
538 $log->debug( sub { Dumper($s) } );
539
540 return $out;
541 }
542
543 =head2 dump
544
545 Display humanly readable dump of record
546
547 =cut
548
549 sub dump {
550 my $self = shift;
551
552 return $self->{ll_db}->dump_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 ($sf =~ /^\^/) {
570 return
571 's/\Q'. $sf .'\E([^\^]*?)\Q'. $from .'\E([^\^]*?)/'. $sf .'$1'. $to .'$2/';
572 } else {
573 return
574 's/\Q'. $from .'\E/'. $to .'/g';
575 }
576 }
577
578 sub modify_record_regexps {
579 my $self = shift;
580 my $modify_record = {@_};
581
582 my $regexpes;
583
584 my $log = $self->_get_logger();
585
586 foreach my $f (keys %$modify_record) {
587 $log->debug("field: $f");
588
589 foreach my $sf (keys %{ $modify_record->{$f} }) {
590 $log->debug("subfield: $sf");
591
592 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
593 my $to = $modify_record->{$f}->{$sf}->{$from};
594 #die "no field?" unless defined($to);
595 $log->debug("transform: |$from| -> |$to|");
596
597 my $regex = _get_regex($sf,$from,$to);
598 push @{ $regexpes->{$f} }, $regex;
599 $log->debug("regex: $regex");
600 }
601 }
602 }
603
604 return $regexpes;
605 }
606
607 =head2 modify_file_regexps
608
609 Generate hash with regexpes to be applied using l<filter> from
610 pseudo hash/yaml format for regex mappings.
611
612 It should be obvious:
613
614 200
615 '^a'
616 ' : ' => '^e'
617 ' = ' => '^d'
618
619 In field I<200> find C<'^a'> and then C<' : '>, and replace it with C<'^e'>.
620 In field I<200> find C<'^a'> and then C<' = '>, and replace it with C<'^d'>.
621
622 my $regexpes = $input->modify_file_regexps( 'conf/modify/common.pl' );
623
624 On undef path it will just return.
625
626 =cut
627
628 sub modify_file_regexps {
629 my $self = shift;
630
631 my $modify_path = shift || return;
632
633 my $log = $self->_get_logger();
634
635 my $regexpes;
636
637 CORE::open(my $fh, $modify_path) || $log->logdie("can't open modify file $modify_path: $!");
638
639 my ($f,$sf);
640
641 while(<$fh>) {
642 chomp;
643 next if (/^#/ || /^\s*$/);
644
645 if (/^\s*(\d+)\s*$/) {
646 $f = $1;
647 $log->debug("field: $f");
648 next;
649 } elsif (/^\s*'([^']*)'\s*$/) {
650 $sf = $1;
651 $log->die("can't define subfiled before field in: $_") unless ($f);
652 $log->debug("subfield: $sf");
653 } elsif (/^\s*'([^']*)'\s*=>\s*'([^']*)'\s*$/) {
654 my ($from,$to) = ($1, $2);
655
656 $log->debug("transform: |$from| -> |$to|");
657
658 my $regex = _get_regex($sf,$from,$to);
659 push @{ $regexpes->{$f} }, $regex;
660 $log->debug("regex: $regex");
661 }
662 }
663
664 return $regexpes;
665 }
666
667 =head1 AUTHOR
668
669 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
670
671 =head1 COPYRIGHT & LICENSE
672
673 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
674
675 This program is free software; you can redistribute it and/or modify it
676 under the same terms as Perl itself.
677
678 =cut
679
680 1; # End of WebPAC::Input

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