NAME¶
Lucy::Index::IndexReader - Read from an inverted index.
SYNOPSIS¶
my $reader = Lucy::Index::IndexReader->open(
index => '/path/to/index',
);
my $seg_readers = $reader->seg_readers;
for my $seg_reader (@$seg_readers) {
my $seg_name = $seg_reader->get_segment->get_name;
my $num_docs = $seg_reader->doc_max;
print "Segment $seg_name ($num_docs documents):\n";
my $doc_reader = $seg_reader->obtain("Lucy::Index::DocReader");
for my $doc_id ( 1 .. $num_docs ) {
my $doc = $doc_reader->fetch_doc($doc_id);
print " $doc_id: $doc->{title}\n";
}
}
DESCRIPTION¶
IndexReader is the interface through which IndexSearcher objects access the
content of an index.
IndexReader objects always represent a point-in-time view of an index as it
existed at the moment the reader was created. If you want search results to
reflect modifications to an index, you must create a new IndexReader after the
update process completes.
IndexReaders are composites; most of the work is done by individual DataReader
sub-components, which may be accessed via
fetch() and
obtain().
The most efficient and powerful access to index data happens at the segment
level via SegReader's sub-components.
CONSTRUCTORS¶
open( [labeled params] )¶
my $reader = Lucy::Index::IndexReader->open(
index => '/path/to/index', # required
snapshot => $snapshot,
manager => $index_manager,
);
IndexReader is an abstract base class;
open() returns the IndexReader
subclass PolyReader, which channels the output of 0 or more SegReaders.
- •
- index - Either a string filepath or a Folder.
- •
- snapshot - A Snapshot. If not supplied, the most recent snapshot
file will be used.
- •
- manager - An IndexManager. Read-locking is off by default;
supplying this argument turns it on.
ABSTRACT METHODS¶
doc_max()¶
Return the maximum number of documents available to the reader, which is also
the highest possible internal document id. Documents which have been marked as
deleted but not yet purged from the index are included in this count.
doc_count()¶
Return the number of documents available to the reader, subtracting any that are
marked as deleted.
del_count()¶
Return the number of documents which have been marked as deleted but not yet
purged from the index.
seg_readers()¶
Return an array of all the SegReaders represented within the IndexReader.
offsets()¶
Return an array with one entry for each segment, corresponding to segment doc_id
start offset.
METHODS¶
fetch(api)¶
Fetch a component, or return undef if the component can't be found.
- •
- api - The name of the DataReader subclass that the desired
component must implement.
obtain(api)¶
Fetch a component, or throw an error if the component can't be found.
- •
- api - The name of the DataReader subclass that the desired
component must implement.
INHERITANCE¶
Lucy::Index::IndexReader isa Lucy::Index::DataReader isa
Lucy::Object::Obj.