use warnings;
use strict;
+use blib;
+
+use WebPAC::Common;
+use base qw/WebPAC::Common/;
+use Text::Iconv;
+use Data::Dumper;
+
=head1 NAME
-WebPAC::Input - core module for input file format
+WebPAC::Input - read different file formats into WebPAC
=head1 VERSION
-Version 0.01
+Version 0.05
=cut
-our $VERSION = '0.01';
+our $VERSION = '0.05';
=head1 SYNOPSIS
-This module will load particular loader module and execute it's functions.
+This module implements input as database which have fixed and known
+I<size> while indexing and single unique numeric identifier for database
+position ranging from 1 to I<size>.
+
+Simply, something that is indexed by unmber from 1 .. I<size>.
+
+Examples of such databases are CDS/ISIS files, MARC files, lines in
+text file, and so on.
+
+Specific file formats are implemented using low-level interface modules,
+located in C<WebPAC::Input::*> namespace which export C<open_db>,
+C<fetch_rec> and optional C<init> functions.
Perhaps a little code snippet.
use WebPAC::Input;
my $db = WebPAC::Input->new(
- format => 'NULL',
- config => $config,
- lookup => $lookup_obj,
- low_mem => 1,
+ module => 'WebPAC::Input::ISIS',
+ config => $config,
+ lookup => $lookup_obj,
+ low_mem => 1,
);
$db->open('/path/to/database');
- print "database size: ",$db->size,"\n";
- while (my $row = $db->fetch) {
- ...
- }
+ print "database size: ",$db->size,"\n";
+ while (my $rec = $db->fetch) {
+ # do something with $rec
+ }
+
+
=head1 FUNCTIONS
Create new input database object.
my $db = new WebPAC::Input(
- format => 'NULL'
+ module => 'WebPAC::Input::MARC',
code_page => 'ISO-8859-2',
low_mem => 1,
+ recode => 'char pairs',
+ no_progress_bar => 1,
);
+C<module> is low-level file format module. See L<WebPAC::Input::Isis> and
+L<WebPAC::Input::MARC>.
+
Optional parametar C<code_page> specify application code page (which will be
used internally). This should probably be your terminal encoding, and by
default, it C<ISO-8859-2>.
Default is not to use C<low_mem> options (see L<MEMORY USAGE> below).
+C<recode> is optional string constisting of character or words pairs that
+should be replaced in input stream.
+
+C<no_progress_bar> disables progress bar output on C<STDOUT>
+
+This function will also call low-level C<init> if it exists with same
+parametars.
+
=cut
sub new {
- my $class = shift;
- my $self = {@_};
+ my $class = shift;
+ my $self = {@_};
bless($self, $class);
- $self->{'code_page'} ||= 'ISO-8859-2';
-
my $log = $self->_get_logger;
+ $log->logconfess("specify low-level file format module") unless ($self->{module});
+ my $module = $self->{module};
+ $module =~ s#::#/#g;
+ $module .= '.pm';
+ $log->debug("require low-level module $self->{module} from $module");
+
+ require $module;
+ #eval $self->{module} .'->import';
+
+ # check if required subclasses are implemented
+ foreach my $subclass (qw/open_db fetch_rec init/) {
+ my $n = $self->{module} . '::' . $subclass;
+ if (! defined &{ $n }) {
+ my $missing = "missing $subclass in $self->{module}";
+ $self->{$subclass} = sub { $log->logwarn($missing) };
+ } else {
+ $self->{$subclass} = \&{ $n };
+ }
+ }
+
+ if ($self->{init}) {
+ $log->debug("calling init");
+ $self->{init}->($self, @_);
+ }
+
+ $self->{'code_page'} ||= 'ISO-8859-2';
+
# running with low_mem flag? well, use DBM::Deep then.
if ($self->{'low_mem'}) {
$log->info("running with low_mem which impacts performance (<32 Mb memory usage)");
$self ? return $self : return undef;
}
+=head2 open
+
+This function will read whole database in memory and produce lookups.
+
+ $input->open(
+ path => '/path/to/database/file',
+ code_page => '852',
+ limit => 500,
+ offset => 6000,
+ lookup => $lookup_obj,
+ stats => 1,
+ );
+
+By default, C<code_page> is assumed to be C<852>.
+
+C<offset> is optional parametar to position at some offset before reading from database.
+
+C<limit> is optional parametar to read just C<limit> records from database
+
+C<stats> create optional report about usage of fields and subfields
+
+Returns size of database, regardless of C<offset> and C<limit>
+parametars, see also C<size>.
+
+=cut
+
+sub open {
+ my $self = shift;
+ my $arg = {@_};
+
+ my $log = $self->_get_logger();
+
+ $log->logcroak("need path") if (! $arg->{'path'});
+ my $code_page = $arg->{'code_page'} || '852';
+
+ # store data in object
+ $self->{'input_code_page'} = $code_page;
+ foreach my $v (qw/path offset limit/) {
+ $self->{$v} = $arg->{$v} if ($arg->{$v});
+ }
+
+ # create Text::Iconv object
+ $self->{iconv} = Text::Iconv->new($code_page,$self->{'code_page'});
+
+ my $filter_ref;
+
+ if ($self->{recode}) {
+ my @r = split(/\s/, $self->{recode});
+ if ($#r % 2 != 1) {
+ $log->logwarn("recode needs even number of elements (some number of valid pairs)");
+ } else {
+ my $recode;
+ while (@r) {
+ my $from = shift @r;
+ my $to = shift @r;
+ $recode->{$from} = $to;
+ }
+
+ my $regex = join '|' => keys %{ $recode };
+
+ $log->debug("using recode regex: $regex");
+
+ $filter_ref = sub {
+ my $t = shift;
+ $t =~ s/($regex)/$recode->{$1}/g;
+ return $t;
+ };
+
+ }
+
+ }
+
+ my ($db, $size) = $self->{open_db}->( $self,
+ path => $arg->{path},
+ filter => $filter_ref,
+ );
+
+ unless (defined($db)) {
+ $log->logwarn("can't open database $arg->{path}, skipping...");
+ return;
+ }
+
+ unless ($size) {
+ $log->logwarn("no records in database $arg->{path}, skipping...");
+ return;
+ }
+
+ my $from_rec = 1;
+ my $to_rec = $size;
+
+ if (my $s = $self->{offset}) {
+ $log->debug("skipping to MFN $s");
+ $from_rec = $s;
+ } else {
+ $self->{offset} = $from_rec;
+ }
+
+ if ($self->{limit}) {
+ $log->debug("limiting to ",$self->{limit}," records");
+ $to_rec = $from_rec + $self->{limit} - 1;
+ $to_rec = $size if ($to_rec > $size);
+ }
+
+ # store size for later
+ $self->{size} = ($to_rec - $from_rec) ? ($to_rec - $from_rec + 1) : 0;
+
+ $log->info("processing $self->{size}/$size records [$from_rec-$to_rec] convert $code_page -> $self->{code_page}", $self->{stats} ? ' [stats]' : '');
+
+ # read database
+ for (my $pos = $from_rec; $pos <= $to_rec; $pos++) {
+
+ $log->debug("position: $pos\n");
+
+ my $rec = $self->{fetch_rec}->($self, $db, $pos );
+
+ $log->debug(sub { Dumper($rec) });
+
+ if (! $rec) {
+ $log->warn("record $pos empty? skipping...");
+ next;
+ }
+
+ # store
+ if ($self->{low_mem}) {
+ $self->{db}->put($pos, $rec);
+ } else {
+ $self->{data}->{$pos} = $rec;
+ }
+
+ # create lookup
+ $self->{'lookup'}->add( $rec ) if ($rec && $self->{'lookup'});
+
+ # update counters for statistics
+ if ($self->{stats}) {
+ map {
+ my $fld = $_;
+ $self->{_stats}->{fld}->{ $fld }++;
+ if (ref($rec->{ $fld }) eq 'ARRAY') {
+ map {
+ if (ref($_) eq 'HASH') {
+ map {
+ $self->{_stats}->{sf}->{ $fld }->{ $_ }++;
+ } keys %{ $_ };
+ } else {
+ $self->{_stats}->{repeatable}->{ $fld }++;
+ }
+ } @{ $rec->{$fld} };
+ }
+ } keys %{ $rec };
+ }
+
+ $self->progress_bar($pos,$to_rec) unless ($self->{no_progress_bar});
+
+ }
+
+ $self->{pos} = -1;
+ $self->{last_pcnt} = 0;
+
+ # store max mfn and return it.
+ $self->{max_pos} = $to_rec;
+ $log->debug("max_pos: $to_rec");
+
+ return $size;
+}
+
+=head2 fetch
+
+Fetch next record from database. It will also displays progress bar.
+
+ my $rec = $isis->fetch;
+
+Record from this function should probably go to C<data_structure> for
+normalisation.
+
+=cut
+
+sub fetch {
+ my $self = shift;
+
+ my $log = $self->_get_logger();
+
+ $log->logconfess("it seems that you didn't load database!") unless ($self->{pos});
+
+ if ($self->{pos} == -1) {
+ $self->{pos} = $self->{offset};
+ } else {
+ $self->{pos}++;
+ }
+
+ my $mfn = $self->{pos};
+
+ if ($mfn > $self->{max_pos}) {
+ $self->{pos} = $self->{max_pos};
+ $log->debug("at EOF");
+ return;
+ }
+
+ $self->progress_bar($mfn,$self->{max_pos}) unless ($self->{no_progress_bar});
+
+ my $rec;
+
+ if ($self->{low_mem}) {
+ $rec = $self->{db}->get($mfn);
+ } else {
+ $rec = $self->{data}->{$mfn};
+ }
+
+ $rec ||= 0E0;
+}
+
+=head2 pos
+
+Returns current record number (MFN).
+
+ print $isis->pos;
+
+First record in database has position 1.
+
+=cut
+
+sub pos {
+ my $self = shift;
+ return $self->{pos};
+}
+
+
+=head2 size
+
+Returns number of records in database
+
+ print $isis->size;
+
+Result from this function can be used to loop through all records
+
+ foreach my $mfn ( 1 ... $isis->size ) { ... }
+
+because it takes into account C<offset> and C<limit>.
+
+=cut
+
+sub size {
+ my $self = shift;
+ return $self->{size};
+}
+
+=head2 seek
+
+Seek to specified MFN in file.
+
+ $isis->seek(42);
+
+First record in database has position 1.
+
+=cut
+
+sub seek {
+ my $self = shift;
+ my $pos = shift || return;
+
+ my $log = $self->_get_logger();
+
+ if ($pos < 1) {
+ $log->warn("seek before first record");
+ $pos = 1;
+ } elsif ($pos > $self->{max_pos}) {
+ $log->warn("seek beyond last record");
+ $pos = $self->{max_pos};
+ }
+
+ return $self->{pos} = (($pos - 1) || -1);
+}
+
+=head2 stats
+
+Dump statistics about field and subfield usage
+
+ print $input->stats;
+
+=cut
+
+sub stats {
+ my $self = shift;
+
+ my $log = $self->_get_logger();
+
+ my $s = $self->{_stats};
+ if (! $s) {
+ $log->warn("called stats, but there is no statistics collected");
+ return;
+ }
+
+ my $max_fld = 0;
+
+ my $out = join("\n",
+ map {
+ my $f = $_ || die "no field";
+ my $v = $s->{fld}->{$f} || die "no s->{fld}->{$f}";
+ $max_fld = $v if ($v > $max_fld);
+
+ my $o = sprintf("%4s %d ~", $f, $v);
+
+ if (defined($s->{sf}->{$f})) {
+ map {
+ $o .= sprintf(" %s:%d", $_, $s->{sf}->{$f}->{$_});
+ } sort keys %{ $s->{sf}->{$f} };
+ }
+
+ if (my $v_r = $s->{repeatable}->{$f}) {
+ $o .= " ($v_r)" if ($v_r != $v);
+ }
+
+ $o;
+ } sort { $a cmp $b } keys %{ $s->{fld} }
+ );
+
+ $log->debug( sub { Dumper($s) } );
+
+ return $out;
+}
+
=head1 MEMORY USAGE
C<low_mem> options is double-edged sword. If enabled, WebPAC
projects / webpac2 / blobdiff