Edit file File name : Reader.pm Content :package Plucene::Index::Reader; use strict; use warnings; use Carp; use Fcntl qw(O_EXCL O_CREAT O_WRONLY); use Plucene::Index::SegmentReader; use Plucene::Index::SegmentInfos; use Plucene::Index::SegmentsReader; =head1 NAME Plucene::Index::Reader - Abstract class for accessing an index =head1 DESCRIPTION IndexReader is an abstract class, providing an interface for accessing an index. Search of an index is done entirely through this abstract interface, so that any subclass which implements it is searchable. Concrete subclasses of IndexReader are usually constructed with a call to the static method L</open>. For efficiency, in this API documents are often referred to via document numbers, non-negative integers which each name a unique document in the index. These document numbers are ephemeral--they may change as documents are added to and deleted from an index. Clients should thus not rely on a given document having the same number between sessions. =head1 METHODS =head2 new my $reader = Plucene::Index::Reader->new($dir_name); This will create a new Plucene::Index::Reader with the passed in directory. =cut sub new { my ($class, $directory) = @_; bless { directory => $directory, writelock => undef }, $class; } =head2 open # If there is only one segment my Plucene::Index::SegmentReader $seg_read = $reader->open; # If there are many segments my Plucene::Index::SegmentsReader $seg_read = $reader->open; Returns an IndexReader reading the index in the given Directory. =cut sub open { my ($self, $directory) = @_; my $reader = Plucene::Index::SegmentInfos->new; $reader->read($directory); my @segments = $reader->segments; return Plucene::Index::SegmentReader->new($reader->info(0), 1) if @segments == 1; return Plucene::Index::SegmentsReader->new( $directory, map Plucene::Index::SegmentReader->new($reader->info($_), $_ == $#segments), 0 .. $#segments ); } =head2 last_modified my $last_modified = Plucene::Index::Reader->last_modified($directory); =cut sub last_modified { (stat "$_[1]/segments")[9] } =head2 index_exists if (Plucene::Index::Reader->index_exists($directory)){ ... } =cut sub index_exists { -e "$_[1]/segments" } =head2 is_locked if (Plucene::Index::Reader->is_locked($directory)){ ... } =cut sub is_locked { -e "$_[1]/write.lock" } =head2 delete $reader->delete($doc); =cut sub delete { my ($self, $doc) = @_; local *FH; if (!$self->{writelock}) { $self->{writelock} = "$self->{directory}/write.lock"; sysopen FH, $self->{writelock}, O_EXCL | O_CREAT | O_WRONLY or croak "Couldn't get lock"; close *FH; } $self->_do_delete($doc); unlink "$self->{directory}/write.lock"; } =head2 delete_term $reader->delete_term($term); This will delete all the documents which contain the passed term. =cut sub delete_term { my ($self, $term) = @_; my $enum = $self->term_docs($term); $self->delete($enum->doc) while $enum->next; } =head2 close $reader->close; =cut sub close { my $self = shift; $self->_do_close; $self->unlock($self->{directory}); } =head2 unlock $reader->unlock($directory); =cut sub unlock { unlink "$_[1]/write.lock"; unlink "$_[1]/commit.lock"; } =head2 num_docs / max_doc / document / is_deleted / norms / terms / doc_freq / term_docs / term_positions / _do_delete / _do_close These must be defined in a subclass =cut sub num_docs { die "Please define num_docs in subclass" } sub max_doc { die "Please define max_doc in subclass" } sub document { die "Please define document in subclass" } sub is_deleted { die "Please define is_deleted in subclass" } sub norms { die "Please define norms in subclass" } sub terms { die "Please define terms in subclass" } sub doc_freq { die "Please define doc_freq in subclass" } sub term_docs { die "Please define term_docs in subclass" } sub term_positions { die "Please define term_positions in subclass" } sub _do_delete { die "Please define _do_delete in subclass" } sub _do_close { die "Please define _do_close in subclass" } 1; Save