9 use base qw/WebPAC::Common/;
11 use Encode qw/from_to/;
15 WebPAC::Input - read different file formats into WebPAC
23 our $VERSION = '0.11';
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',
162 code_page => 'cp852',
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<cp852>.
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'} || 'cp852';
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});
220 if ($self->{recode}) {
221 my @r = split(/\s/, $self->{recode});
223 $log->logwarn("recode needs even number of elements (some number of valid pairs)");
228 $recode_map->{$from} = $to;
231 $recode_regex = join '|' => keys %{ $recode_map };
233 $log->debug("using recode regex: $recode_regex");
238 my $rec_regex = $self->modify_record_regexps(%{ $arg->{modify_records} });
239 $log->debug("rec_regex: ", Dumper($rec_regex));
241 my ($db, $size) = $self->{open_db}->( $self,
242 path => $arg->{path},
244 # my ($l,$f_nr) = @_;
245 # return unless defined($l);
246 # from_to($l, $code_page, $self->{'encoding'});
247 # $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
253 unless (defined($db)) {
254 $log->logwarn("can't open database $arg->{path}, skipping...");
259 $log->logwarn("no records in database $arg->{path}, skipping...");
266 if (my $s = $self->{offset}) {
267 $log->debug("skipping to MFN $s");
270 $self->{offset} = $from_rec;
273 if ($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);
279 # store size for later
280 $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
282 $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{encoding}", $self->{stats} ? ' [stats]' : '');
285 for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
287 $log->debug("position: $pos\n");
289 my $rec = $self->{fetch_rec}->($self, $db, $pos, sub {
291 # return unless defined($l);
292 # return $l unless ($rec_regex && $f_nr);
294 $log->debug("-=> $f_nr ## $l");
296 # codepage conversion and recode_regex
297 from_to($l, $code_page, $self->{'encoding'});
298 $l =~ s/($recode_regex)/$recode_map->{$1}/g if ($recode_regex && $recode_map);
301 if ($rec_regex && defined($rec_regex->{$f_nr})) {
302 $log->logconfess("regexps->{$f_nr} must be ARRAY") if (ref($rec_regex->{$f_nr}) ne 'ARRAY');
304 foreach my $r (@{ $rec_regex->{$f_nr} }) {
308 $log->debug("REGEX on $f_nr eval \$l =~ $r\n## old l: [$old_l]\n## new l: [$l]");
310 $log->error("error applying regex: $r") if ($@);
314 $log->debug("<=- $f_nr ## $l");
318 $log->debug(sub { Dumper($rec) });
321 $log->warn("record $pos empty? skipping...");
326 if ($self->{low_mem}) {
327 $self->{db}->put($pos, $rec);
329 $self->{data}->{$pos} = $rec;
333 $arg->{'lookup_coderef'}->( $rec ) if ($rec && $arg->{'lookup_coderef'});
335 # update counters for statistics
336 if ($self->{stats}) {
338 # fetch clean record with regexpes applied for statistics
339 my $rec = $self->{fetch_rec}->($self, $db, $pos);
341 foreach my $fld (keys %{ $rec }) {
342 $self->{_stats}->{fld}->{ $fld }++;
344 $log->logdie("invalid record fild $fld, not ARRAY")
345 unless (ref($rec->{ $fld }) eq 'ARRAY');
347 foreach my $row (@{ $rec->{$fld} }) {
349 if (ref($row) eq 'HASH') {
351 foreach my $sf (keys %{ $row }) {
352 next if ($sf eq 'subfields');
353 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{count}++;
354 $self->{_stats}->{sf}->{ $fld }->{ $sf }->{repeatable}++
355 if (ref($row->{$sf}) eq 'ARRAY');
359 $self->{_stats}->{repeatable}->{ $fld }++;
365 $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
370 $self->{last_pcnt} = 0;
372 # store max mfn and return it.
373 $self->{max_pos} = $to_rec;
374 $log->debug("max_pos: $to_rec");
381 Fetch next record from database. It will also displays progress bar.
383 my $rec = $isis->fetch;
385 Record from this function should probably go to C<data_structure> for
393 my $log = $self->_get_logger();
395 $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
397 if ($self->{pos} == -1) {
398 $self->{pos} = $self->{offset};
403 my $mfn = $self->{pos};
405 if ($mfn > $self->{max_pos}) {
406 $self->{pos} = $self->{max_pos};
407 $log->debug("at EOF");
411 $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
415 if ($self->{low_mem}) {
416 $rec = $self->{db}->get($mfn);
418 $rec = $self->{data}->{$mfn};
426 Returns current record number (MFN).
430 First record in database has position 1.
442 Returns number of records in database
446 Result from this function can be used to loop through all records
448 foreach my $mfn ( 1 ... $isis->size ) { ... }
450 because it takes into account C<offset> and C<limit>.
456 return $self->{size};
461 Seek to specified MFN in file.
465 First record in database has position 1.
471 my $pos = shift || return;
473 my $log = $self->_get_logger();
476 $log->warn("seek before first record");
478 } elsif ($pos > $self->{max_pos}) {
479 $log->warn("seek beyond last record");
480 $pos = $self->{max_pos};
483 return $self->{pos} = (($pos - 1) || -1);
488 Dump statistics about field and subfield usage
497 my $log = $self->_get_logger();
499 my $s = $self->{_stats};
501 $log->warn("called stats, but there is no statistics collected");
509 my $f = $_ || die "no field";
510 my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
511 $max_fld = $v if ($v > $max_fld);
513 my $o = sprintf("%4s %d ~", $f, $v);
515 if (defined($s->{sf}->{$f})) {
517 $o .= sprintf(" %s:%d%s", $_,
518 $s->{sf}->{$f}->{$_}->{count},
519 $s->{sf}->{$f}->{$_}->{repeatable} ? '*' : '',
521 } sort keys %{ $s->{sf}->{$f} };
524 if (my $v_r = $s->{repeatable}->{$f}) {
525 $o .= " ($v_r)" if ($v_r != $v);
529 } sort { $a cmp $b } keys %{ $s->{fld} }
532 $log->debug( sub { Dumper($s) } );
537 =head2 modify_record_regexps
539 Generate hash with regexpes to be applied using L<filter>.
541 my $regexpes = $input->modify_record_regexps(
542 900 => { '^a' => { ' : ' => '^b' } },
543 901 => { '*' => { '^b' => ' ; ' } },
548 sub modify_record_regexps {
550 my $modify_record = {@_};
554 my $log = $self->_get_logger();
556 foreach my $f (keys %$modify_record) {
557 $log->debug("field: $f");
559 foreach my $sf (keys %{ $modify_record->{$f} }) {
560 $log->debug("subfield: $sf");
562 foreach my $from (keys %{ $modify_record->{$f}->{$sf} }) {
563 my $to = $modify_record->{$f}->{$sf}->{$from};
564 #die "no field?" unless defined($to);
565 $log->debug("transform: |$from| -> |$to|");
569 's/\Q'. $sf .'\E(.*?)\Q'. $from .'\E(.*?)/'. $sf .'$1'. $to .'$2/g';
570 push @{ $regexpes->{$f} }, $regex;
571 $log->debug(">>>>> $regex [sf]");
574 's/\Q'. $from .'\E/'. $to .'/g';
575 push @{ $regexpes->{$f} }, $regex;
576 $log->debug(">>>>> $regex [global]");
588 C<low_mem> options is double-edged sword. If enabled, WebPAC
589 will run on memory constraint machines (which doesn't have enough
590 physical RAM to create memory structure for whole source database).
592 If your machine has 512Mb or more of RAM and database is around 10000 records,
593 memory shouldn't be an issue. If you don't have enough physical RAM, you
594 might consider using virtual memory (if your operating system is handling it
595 well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
596 parsed structure of ISIS database (this is what C<low_mem> option does).
598 Hitting swap at end of reading source database is probably o.k. However,
599 hitting swap before 90% will dramatically decrease performance and you will
600 be better off with C<low_mem> and using rest of availble memory for
601 operating system disk cache (Linux is particuallary good about this).
602 However, every access to database record will require disk access, so
603 generation phase will be slower 10-100 times.
605 Parsed structures are essential - you just have option to trade RAM memory
606 (which is fast) for disk space (which is slow). Be sure to have planty of
607 disk space if you are using C<low_mem> and thus L<DBM::Deep>.
609 However, when WebPAC is running on desktop machines (or laptops :-), it's
610 highly undesireable for system to start swapping. Using C<low_mem> option can
611 reduce WecPAC memory usage to around 64Mb for same database with lookup
612 fields and sorted indexes which stay in RAM. Performance will suffer, but
613 memory usage will really be minimal. It might be also more confortable to
614 run WebPAC reniced on those machines.
619 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
621 =head1 COPYRIGHT & LICENSE
623 Copyright 2005-2006 Dobrica Pavlinusic, All Rights Reserved.
625 This program is free software; you can redistribute it and/or modify it
626 under the same terms as Perl itself.
630 1; # End of WebPAC::Input