/[webpac2]/trunk/lib/WebPAC/Input.pm
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Revision 606 - (show annotations)
Tue Aug 1 13:59:47 2006 UTC (17 years, 9 months ago) by dpavlin
File size: 14699 byte(s)
added --parallel option to utilize multiple CPUs in machine

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 Text::Iconv;
11 use Data::Dumper;
12
13 =head1 NAME
14
15 WebPAC::Input - read different file formats into WebPAC
16
17 =head1 VERSION
18
19 Version 0.09
20
21 =cut
22
23 our $VERSION = '0.09';
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 low_mem => 1,
47 );
48
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
53 }
54
55
56
57 =head1 FUNCTIONS
58
59 =head2 new
60
61 Create new input database object.
62
63 my $db = new WebPAC::Input(
64 module => 'WebPAC::Input::MARC',
65 encoding => 'ISO-8859-2',
66 low_mem => 1,
67 recode => 'char pairs',
68 no_progress_bar => 1,
69 );
70
71 C<module> is low-level file format module. See L<WebPAC::Input::ISIS> and
72 L<WebPAC::Input::MARC>.
73
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>.
77
78 Default is not to use C<low_mem> options (see L<MEMORY USAGE> below).
79
80 C<recode> is optional string constisting of character or words pairs that
81 should be replaced in input stream.
82
83 C<no_progress_bar> disables progress bar output on C<STDOUT>
84
85 This function will also call low-level C<init> if it exists with same
86 parametars.
87
88 =cut
89
90 sub new {
91 my $class = shift;
92 my $self = {@_};
93 bless($self, $class);
94
95 my $log = $self->_get_logger;
96
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});
99
100 $log->logconfess("specify low-level file format module") unless ($self->{module});
101 my $module = $self->{module};
102 $module =~ s#::#/#g;
103 $module .= '.pm';
104 $log->debug("require low-level module $self->{module} from $module");
105
106 require $module;
107 #eval $self->{module} .'->import';
108
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) };
115 } else {
116 $self->{$subclass} = \&{ $n };
117 }
118 }
119
120 if ($self->{init}) {
121 $log->debug("calling init");
122 $self->{init}->($self, @_);
123 }
124
125 $self->{'encoding'} ||= 'ISO-8859-2';
126
127 # running with low_mem flag? well, use DBM::Deep then.
128 if ($self->{'low_mem'}) {
129 $log->info("running with low_mem which impacts performance (<32 Mb memory usage)");
130
131 my $db_file = "data.db";
132
133 if (-e $db_file) {
134 unlink $db_file or $log->logdie("can't remove '$db_file' from last run");
135 $log->debug("removed '$db_file' from last run");
136 }
137
138 require DBM::Deep;
139
140 my $db = new DBM::Deep $db_file;
141
142 $log->logdie("DBM::Deep error: $!") unless ($db);
143
144 if ($db->error()) {
145 $log->logdie("can't open '$db_file' under low_mem: ",$db->error());
146 } else {
147 $log->debug("using file '$db_file' for DBM::Deep");
148 }
149
150 $self->{'db'} = $db;
151 }
152
153 $self ? return $self : return undef;
154 }
155
156 =head2 open
157
158 This function will read whole database in memory and produce lookups.
159
160 $input->open(
161 path => '/path/to/database/file',
162 code_page => '852',
163 limit => 500,
164 offset => 6000,
165 lookup => $lookup_obj,
166 stats => 1,
167 lookup_ref => sub {
168 my ($k,$v) = @_;
169 # store lookup $k => $v
170 },
171 modify_records => {
172 900 => { '^a' => { ' : ' => '^b' } },
173 901 => { '*' => { '^b' => ' ; ' } },
174 },
175 );
176
177 By default, C<code_page> is assumed to be C<852>.
178
179 C<offset> is optional parametar to position at some offset before reading from database.
180
181 C<limit> is optional parametar to read just C<limit> records from database
182
183 C<stats> create optional report about usage of fields and subfields
184
185 C<lookup_coderef> is closure to call when adding C<< key => 'value' >> combinations to
186 lookup.
187
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
190 defined as C<*>.
191
192 Returns size of database, regardless of C<offset> and C<limit>
193 parametars, see also C<size>.
194
195 =cut
196
197 sub open {
198 my $self = shift;
199 my $arg = {@_};
200
201 my $log = $self->_get_logger();
202
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');
206
207 $log->logcroak("need path") if (! $arg->{'path'});
208 my $code_page = $arg->{'code_page'} || '852';
209
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});
214 }
215
216 # create Text::Iconv object
217 $self->{iconv} = Text::Iconv->new($code_page,$self->{'encoding'}); ## FIXME remove!
218
219 my $filter_ref;
220 my $recode_regex;
221 my $recode_map;
222
223 if ($self->{recode}) {
224 my @r = split(/\s/, $self->{recode});
225 if ($#r % 2 != 1) {
226 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
227 } else {
228 while (@r) {
229 my $from = shift @r;
230 my $to = shift @r;
231 $recode_map->{$from} = $to;
232 }
233
234 $recode_regex = join '|' => keys %{ $recode_map };
235
236 $log->debug("using recode regex: $recode_regex");
237 }
238
239 }
240
241 my $rec_regex = $self->modify_record_regexps(%{ $arg->{modify_records} });
242 $log->debug("rec_regex: ", Dumper($rec_regex));
243
244 my ($db, $size) = $self->{open_db}->( $self,
245 path => $arg->{path},
246 filter => sub {
247 my ($l,$f_nr) = @_;
248 return unless defined($l);
249
250 ## FIXME remove iconv!
251 $l = $self->{iconv}->convert($l) if ($self->{iconv});
252
253 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
254
255 ## FIXME remove this warning when we are sure that none of API is calling
256 ## this wrongly
257 #warn "filter called without field number" unless ($f_nr);
258
259 return $l unless ($rec_regex && $f_nr);
260
261 # apply regexps
262 if ($rec_regex && defined($rec_regex->{$f_nr})) {
263 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
264 my $c = 0;
265 foreach my $r (@{ $rec_regex->{$f_nr} }) {
266 while ( eval '$l =~ ' . $r ) { $c++ };
267 }
268 warn "## field $f_nr triggered $c regexpes\n" if ($c && $self->{debug});
269 }
270
271 return $l;
272 },
273 %{ $arg },
274 );
275
276 unless (defined($db)) {
277 $log->logwarn("can't open database $arg->{path}, skipping...");
278 return;
279 }
280
281 unless ($size) {
282 $log->logwarn("no records in database $arg->{path}, skipping...");
283 return;
284 }
285
286 my $from_rec = 1;
287 my $to_rec = $size;
288
289 if (my $s = $self->{offset}) {
290 $log->debug("skipping to MFN $s");
291 $from_rec = $s;
292 } else {
293 $self->{offset} = $from_rec;
294 }
295
296 if ($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);
300 }
301
302 # store size for later
303 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
304
305 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
306
307 # read database
308 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
309
310 $log->debug("position: $pos\n");
311
312 my $rec = $self->{fetch_rec}->($self, $db, $pos );
313
314 $log->debug(sub { Dumper($rec) });
315
316 if (! $rec) {
317 $log->warn("record $pos empty? skipping...");
318 next;
319 }
320
321 # store
322 if ($self->{low_mem}) {
323 $self->{db}->put($pos, $rec);
324 } else {
325 $self->{data}->{$pos} = $rec;
326 }
327
328 # create lookup
329 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
330
331 # update counters for statistics
332 if ($self->{stats}) {
333
334 foreach my $fld (keys %{ $rec }) {
335 $self->{_stats}->{fld}->{ $fld }++;
336
337 $log->logdie("invalid record fild $fld, not ARRAY")
338 unless (ref($rec->{ $fld }) eq 'ARRAY');
339
340 foreach my $row (@{ $rec->{$fld} }) {
341
342 if (ref($row) eq 'HASH') {
343
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');
348 }
349
350 } else {
351 $self->{_stats}->{repeatable}->{ $fld }++;
352 }
353 }
354 }
355 }
356
357 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
358
359 }
360
361 $self->{pos} = -1;
362 $self->{last_pcnt} = 0;
363
364 # store max mfn and return it.
365 $self->{max_pos} = $to_rec;
366 $log->debug("max_pos: $to_rec");
367
368 return $size;
369 }
370
371 =head2 fetch
372
373 Fetch next record from database. It will also displays progress bar.
374
375 my $rec = $isis->fetch;
376
377 Record from this function should probably go to C<data_structure> for
378 normalisation.
379
380 =cut
381
382 sub fetch {
383 my $self = shift;
384
385 my $log = $self->_get_logger();
386
387 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
388
389 if ($self->{pos} == -1) {
390 $self->{pos} = $self->{offset};
391 } else {
392 $self->{pos}++;
393 }
394
395 my $mfn = $self->{pos};
396
397 if ($mfn > $self->{max_pos}) {
398 $self->{pos} = $self->{max_pos};
399 $log->debug("at EOF");
400 return;
401 }
402
403 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
404
405 my $rec;
406
407 if ($self->{low_mem}) {
408 $rec = $self->{db}->get($mfn);
409 } else {
410 $rec = $self->{data}->{$mfn};
411 }
412
413 $rec ||= 0E0;
414 }
415
416 =head2 pos
417
418 Returns current record number (MFN).
419
420 print $isis->pos;
421
422 First record in database has position 1.
423
424 =cut
425
426 sub pos {
427 my $self = shift;
428 return $self->{pos};
429 }
430
431
432 =head2 size
433
434 Returns number of records in database
435
436 print $isis->size;
437
438 Result from this function can be used to loop through all records
439
440 foreach my $mfn ( 1 ... $isis->size ) { ... }
441
442 because it takes into account C<offset> and C<limit>.
443
444 =cut
445
446 sub size {
447 my $self = shift;
448 return $self->{size};
449 }
450
451 =head2 seek
452
453 Seek to specified MFN in file.
454
455 $isis->seek(42);
456
457 First record in database has position 1.
458
459 =cut
460
461 sub seek {
462 my $self = shift;
463 my $pos = shift || return;
464
465 my $log = $self->_get_logger();
466
467 if ($pos < 1) {
468 $log->warn("seek before first record");
469 $pos = 1;
470 } elsif ($pos > $self->{max_pos}) {
471 $log->warn("seek beyond last record");
472 $pos = $self->{max_pos};
473 }
474
475 return $self->{pos} = (($pos - 1) || -1);
476 }
477
478 =head2 stats
479
480 Dump statistics about field and subfield usage
481
482 print $input->stats;
483
484 =cut
485
486 sub stats {
487 my $self = shift;
488
489 my $log = $self->_get_logger();
490
491 my $s = $self->{_stats};
492 if (! $s) {
493 $log->warn("called stats, but there is no statistics collected");
494 return;
495 }
496
497 my $max_fld = 0;
498
499 my $out = join("\n",
500 map {
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);
504
505 my $o = sprintf("%4s %d ~", $f, $v);
506
507 if (defined($s->{sf}->{$f})) {
508 map {
509 $o .= sprintf(" %s:%d%s", $_,
510 $s->{sf}->{$f}->{$_}->{count},
511 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
512 );
513 } sort keys %{ $s->{sf}->{$f} };
514 }
515
516 if (my $v_r = $s->{repeatable}->{$f}) {
517 $o .= " ($v_r)" if ($v_r != $v);
518 }
519
520 $o;
521 } sort { $a cmp $b } keys %{ $s->{fld} }
522 );
523
524 $log->debug( sub { Dumper($s) } );
525
526 return $out;
527 }
528
529 =head2 modify_record_regexps
530
531 Generate hash with regexpes to be applied using L<filter>.
532
533 my $regexpes = $input->modify_record_regexps(
534 900 => { '^a' => { ' : ' => '^b' } },
535 901 => { '*' => { '^b' => ' ; ' } },
536 );
537
538 =cut
539
540 sub modify_record_regexps {
541 my $self = shift;
542 my $modify_record = {@_};
543
544 my $regexpes;
545
546 foreach my $f (keys %$modify_record) {
547 warn "--- f: $f\n";
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| -> |$to|\n";
554
555 if ($sf =~ /^\^/) {
556 my $regex =
557 's/\Q'. $sf .'\E([^\^]+)\Q'. $from .'\E([^\^]+)/'. $sf .'$1'. $to .'$2/g';
558 push @{ $regexpes->{$f} }, $regex;
559 warn ">>>>> $regex [sf]\n";
560 } else {
561 my $regex =
562 's/\Q'. $from .'\E/'. $to .'/g';
563 push @{ $regexpes->{$f} }, $regex;
564 warn ">>>>> $regex [global]\n";
565 }
566
567 }
568 }
569 }
570
571 return $regexpes;
572 }
573
574 =head1 MEMORY USAGE
575
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).
579
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).
585
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.
592
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>.
596
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.
603
604
605 =head1 AUTHOR
606
607 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
608
609 =head1 COPYRIGHT & LICENSE
610
611 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
612
613 This program is free software; you can redistribute it and/or modify it
614 under the same terms as Perl itself.
615
616 =cut
617
618 1; # End of WebPAC::Input

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